California Baseline Ozone Transport Study (CABOTS): Ozonesonde Measurements

NASA Astrophysics Data System (ADS)

Eiserloh, A. J., Jr.; Chiao, S.; Spitze, J.; Cauley, S.; Clark, J.; Roberts, M.

2016-12-01

Because the EPA recently lowered the ambient air quality standard for the 8-hr average of ozone (O3) to70 ppbv, California must continue to achieve significant reductions in ozone precursor emissions and prepare for new State Implementation Plans (SIP) to demonstrate how ground-level ambient ozone will be reduced below the new health-based standard. Prior studies suggest that background levels of ozone traveling across the Pacific Ocean can significantly influence surface ozone throughout California, particularly during the spring. Evidence has been presented indicating that background levels of ozone continue to increase in the western United States over the recent few decades, implying more ozone exceedances in the future. To better understand the contributions of the external natural and anthropogenic pollution sources as well as atmospheric processes for surface ozone concentrations in California during the spring and summer months, the California Baseline Ozone Transport Study (CABOTS) has been established. One major goal of CABOTS is to implement near daily ozonesonde measurements along the California Coast to quantify background ozone aloft before entering the State during high ozone season. CABOTS has been ongoing from May through August of 2016 launching ozonesondes from Bodega Bay and Half Moon Bay, California. The temporal progression of ozonesonde measurements and subsequent analysis of the data will be discussed with a focus on the contribution of background ozone to surface ozone sites inland as well as likely origins of layers aloft. Comparisons of current ozonesondes versus prior ozonesonde studies of California will also be performed. A few selected cases of high ozone layers moving onshore from different sources will be discussed as well.

Permeable Reactive Barrier: Technology Update

DTIC Science & Technology

2011-06-01

while also looking at how and when to rejuvenate PRBs already in use. Section 9 discusses the green and sustainable concept as related to PRBs. While...collected during operation of the PRB. A number of site-specific factors may influence the decision to remove an aged PRB, including the following...specific PRB system. Aging of the PRB system—that is, geochemical changes that may occur over time—also should be considered. Using the CSM

Isoform specificity of progesterone receptor antibodies

PubMed Central

Fabris, Victoria; Abascal, María F; Giulianelli, Sebastián; May, María; Sequeira, Gonzalo R; Jacobsen, Britta; Lombès, Marc; Han, Julie; Tran, Luan; Molinolo, Alfredo

2017-01-01

Abstract Progesterone receptors (PR) are prognostic and predictive biomarkers in hormone‐dependent cancers. Two main PR isoforms have been described, PRB and PRA, that differ only in that PRB has 164 extra N‐terminal amino acids. It has been reported that several antibodies empirically exclusively recognize PRA in formalin‐fixed paraffin‐embedded (FFPE) tissues. To confirm these findings, we used human breast cancer xenograft models, T47D‐YA and ‐YB cells expressing PRA or PRB, respectively, MDA‐MB‐231 cells modified to synthesize PRB, and MDA‐MB‐231/iPRAB cells which can bi‐inducibly express either PRA or PRB. Cells were injected into immunocompromised mice to generate tumours exclusively expressing PRA or PRB. PR isoform expression was verified using immunoblots. FFPE samples from the same tumours were studied by immunohistochemistry using H‐190, clone 636, clone 16, and Ab‐6 anti‐PR antibodies, the latter exclusively recognizing PRB. Except for Ab‐6, all antibodies displayed a similar staining pattern. Our results indicate that clones 16, 636, and the H‐190 antibody recognize both PR isoforms. They point to the need for more stringency in evaluating the true specificity of purported PRA‐specific antibodies as the PRA/PRB ratio may have prognostic and predictive value in breast cancer. PMID:29085663

Endosulfan Degradation by Selected Strains of Plant Growth Promoting Rhizobacteria.

PubMed

Rani, Rupa; Kumar, Vipin

2017-07-01

Sixty endosulfan tolerant bacterial strains were isolated from pesticide stressed agricultural soils. Five most tolerant strains were tested for plant growth promoting (PGP) activities and endosulfan degradation under different optimizing conditions in broth and soil. The strains PRB101 and PRB77 were the most efficient in terms of endosulfan degradation and PGP activities and showed solubilization indexes of 3.3 and 3.1 mm, indole acetic acid production of 71 and 68 μg mL -1 , siderophore zones of 13 mm each at the recommended dosage, respectively. Hydrogen cyanide and ammonia production remained unaffected in the presence of endosulfan. PRB101 and PRB77 strains were able to degrade 74% and 70% of endosulfan in broth and 67% and 63% in soil, respectively. Based on 16S rDNA analysis, the strains PRB101 and PRB77 exhibited 99% homology with Bacillus sp. KF984414 and Bacillus sp. LN849696, respectively.

Rural southeast Texas air quality measurements during the 2006 Texas Air Quality Study.

PubMed

Schade, Gunnar W; Khan, Siraj; Park, Changhyoun; Boedeker, Ian

2011-10-01

The authors conducted air quality measurements of the criteria pollutants carbon monoxide, nitrogen oxides, and ozone together with meteorological measurements at a park site southeast of College Station, TX, during the 2006 Texas Air Quality Study II (TexAQS). Ozone, a primary focus of the measurements, was above 80 ppb during 3 days and above 75 ppb during additional 8 days in summer 2006, suggestive of possible violations of the ozone National Ambient Air Quality Standard (NAAQS) in this area. In concordance with other air quality measurements during the TexAQS II, elevated ozone mixing ratios coincided with northerly flows during days after cold front passages. Ozone background during these days was as high as 80 ppb, whereas southerly air flows generally provided for an ozone background lower than 40 ppb. Back trajectory analysis shows that local ozone mixing ratios can also be strongly affected by the Houston urban pollution plume, leading to late afternoon ozone increases of as high as 50 ppb above background under favorable transport conditions. The trajectory analysis also shows that ozone background increases steadily the longer a southern air mass resides over Texas after entering from the Gulf of Mexico. In light of these and other TexAQS findings, it appears that ozone air quality is affected throughout east Texas by both long-range and regional ozone transport, and that improvements therefore will require at least a regionally oriented instead of the current locally oriented ozone precursor reduction policies.

Regional and local background ozone in Houston during Texas Air Quality Study 2006

NASA Astrophysics Data System (ADS)

Langford, A. O.; Senff, C. J.; Banta, R. M.; Hardesty, R. M.; Alvarez, R. J.; Sandberg, Scott P.; Darby, Lisa S.

2009-04-01

Principal Component Analysis (PCA) is used to isolate the common modes of behavior in the daily maximum 8-h average ozone mixing ratios measured at 30 Continuous Ambient Monitoring Stations in the Houston-Galveston-Brazoria area during the Second Texas Air Quality Study field intensive (1 August to 15 October 2006). Three principal components suffice to explain 93% of the total variance. Nearly 84% is explained by the first component, which is attributed to changes in the "regional background" determined primarily by the large-scale winds. The second component (6%) is attributed to changes in the "local background," that is, ozone photochemically produced in the Houston area and spatially and temporally averaged by local circulations. Finally, the third component (3.5%) is attributed to short-lived plumes containing high ozone originating from industrial areas along Galveston Bay and the Houston Ship Channel. Regional background ozone concentrations derived using the first component compare well with mean ozone concentrations measured above the Gulf of Mexico by the tunable profiler for aerosols and ozone lidar aboard the NOAA Twin Otter. The PCA regional background values also agree well with background values derived using the lowest daily 8-h maximum method of Nielsen-Gammon et al. (2005), provided the Galveston Airport data (C34) are omitted from that analysis. The differences found when Galveston is included are caused by the sea breeze, which depresses ozone at Galveston relative to sites further inland. PCA removes the effects of this and other local circulations to obtain a regional background value representative of the greater Houston area.

Background Ozone in Southern China During 1994-2015: Role of Anthropogenic Emission and Climate Change

NASA Astrophysics Data System (ADS)

Wang, T.; Zhang, L.; Poon, S.

2016-12-01

Tropospheric ozone plays important roles in atmospheric chemistry, air quality, and climate. Changes in background ozone concentrations and underlying causes are therefore of great interest to the scientific community and governments. Compared with North America and Europe, long-term measurements of background ozone in China are scarce. This study reports the longest continuous ozone record in southern China measured at a background site (Hok Tsui) in Hong Kong during 1994-2015. The analysis of the 22-year record shows that the surface ozone in the background atmosphere of southern China has been increasing, with an overall Theil-Sen estimated rate of 0.43 ppbv/yr. Compared with our previous results during 1994-2007 (Wang et al., 2009), the average rate of increase has slowed down over during 2008-2015 (0.32 vs. 0.58 ppbv/yr), possibly due to smaller increase or even decrease in ozone precursors emission in mainland China in recent years. The average rates of change show significant seasonal differences with the largest rate occurring in summer (0.32, 0.55, 0.52, and 0.36 ppbv/yr in spring, summer, autumn, and winter, respectively). Monthly mean ozone concentrations at Hok Tsui are compared against an East Asian Monsoon index. It is found that only the summer-time ozone over period 2008-2015 has a strong positive correlation with the index, suggesting that climate might have played an important role in driving the ozone increase observed in summer since 2008. The ozone trend in Hong Kong will be compared to those from other regions in East Asia, and the role of emission changes in Asia will be discussed.

Issues and progress in determining background ozone and particle concentrations

NASA Astrophysics Data System (ADS)

Pinto, J. P.

2011-12-01

Exposure to ambient ozone is associated with a variety of health outcomes ranging from mild breathing discomfort to mortality. For the purpose of health risk and policy assessments EPA evaluates the anthropogenic increase in ozone above background concentrations and has defined the North American (NA) background concentration of O3 as that which would occur in the U.S. in the absence of anthropogenic emissions of precursors in the U.S., Canada, and Mexico. Monthly average NA background ozone has been used to evaluate health risks, but EPA and state air quality managers must also estimate day specific ozone background levels for high ozone episodes as part of urban scale photochemical modeling efforts to support ozone regulatory programs. The background concentration of O3 is of more concern than other air pollutants because it typically represents a much larger fraction of observed O3 than do the backgrounds of other criteria pollutants (particulate matter (PM), CO, NO2, SO2). NA background cannot be determined directly from ambient monitoring data because of the influence of NA precursor emissions on formation of ozone within NA. Instead, estimates of NA background O3 have been based on GEOS-Chem using simulations in which NA anthropogenic precursor emissions are zeroed out. Thus, modeled NA background O3 includes contributions from natural sources of precursors (including CH4, NMVOCs, NOx, and CO) everywhere in the world, anthropogenic sources of precursors outside of NA, and downward transport of O3 from the stratosphere. Although monitoring data cannot determine NA background directly, measurements by satellites, aircraft, ozonesondes and surface monitors have proved to be highly useful for identifying sources of background O3 and for evaluating the performance of the GEOS-Chem model. Model simulated NA background concentrations are strong functions of location and season with large inter-day variability and with values increasing with elevation and higher in spring than in summer, and tend to be highest in the Intermountain West during spring. Estimates of annual average NA and other background definitions that have been considered will be presented. Issues associated with modeling background concentrations for both health-risk assessments and for episodic regulatory air quality programs will be discussed, and proposals for new atmospheric measurements and model improvements needed to quantify more accurately background contributions to ozone will also be presented. The views expressed are those of the author and do not necessarily represent the views or policies of the U.S. Environmental Protection Agency.

A Model and Satellite-Based Analysis of the Tropospheric Ozone Distribution in Clear Versus Convectively Cloudy Conditions

NASA Technical Reports Server (NTRS)

Strode, Sarah A.; Douglass, Anne R.; Ziemke, Jerald R.; Manyin, Michael; Nielsen, J. Eric; Oman, Luke D.

2017-01-01

Satellite observations of in-cloud ozone concentrations from the Ozone Monitoring Instrument and Microwave Limb Sounder instruments show substantial differences from background ozone concentrations. We develop a method for comparing a free-running chemistry-climate model (CCM) to in-cloud and background ozone observations using a simple criterion based on cloud fraction to separate cloudy and clear-sky days. We demonstrate that the CCM simulates key features of the in-cloud versus background ozone differences and of the geographic distribution of in-cloud ozone. Since the agreement is not dependent on matching the meteorological conditions of a specific day, this is a promising method for diagnosing how accurately CCMs represent the relationships between ozone and clouds, including the lower ozone concentrations shown by in-cloud satellite observations. Since clouds are associated with convection as well as changes in chemistry, we diagnose the tendency of tropical ozone at 400 hPa due to chemistry, convection and turbulence, and large-scale dynamics. While convection acts to reduce ozone concentrations at 400 hPa throughout much of the tropics, it has the opposite effect over highly polluted regions of South and East Asia.

pRb phosphorylation regulates the proliferation of supporting cells in gentamicin-damaged neonatal avian utricle.

PubMed

Wu, Jingfang; Sun, Shan; Li, Wenyan; Chen, Yan; Li, Huawei

2014-10-01

The ability of nonmammalian vertebrates to regenerate hair cells (HCs) after damage-induced HC loss has stimulated and inspired research in the field of HC regeneration. The protein pRb encoded by retinoblastoma gene Rb1 forces sensory progenitor cells to exit cell cycle and maintain differentiated HCs and supporting cells (SCs) in a quiescent state. pRb function is regulated by phosphorylation through the MEK/ERK or the pRb/Raf-1 signaling pathway. In our previous study, we have shown that pRb phosphorylation is crucial for progenitor cell proliferation and survival during the early embryonic stage of avian otocyst sensory epithelium development. However, in damaged avian utricle, the role of pRb in regulating the cell cycling of SCs or HCs regeneration still remains unclear. To further elucidate the function of pRb phosphorylation on SCs re-entering the cell cycle triggered by gentamycin-induced HCs damage, we isolated neonatal chicken utricles and treated them with the MEK inhibitor U0126 or the pRb/Raf-1 inhibitor RRD-251, respectively in vitro. We found that after gentamycin-induced HCs damage, pRb phosphorylation is important for the quiescent SCs re-entering the cell cycle in the neonatal chicken utricle. In addition, the proliferation of SCs decreased in a dose-dependent manner in response to both U0126 and RRD-251, which indicates that both the MEK/ERK and the pRb/Raf-1 signaling pathway play important roles in pRb phosphorylation in damaged neonatal chicken utricle. Together, these findings on the function of pRb in damaged neonatal chicken utricle improve our understanding of the regulation of the cell cycle of SCs after HCs loss and may shed light on the mammalian HC regeneration from SCs in damaged organs.

Expression of progesterone receptor B is associated with G0/G1 arrest of the cell cycle and growth inhibition in NIH3T3 cells

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

Horiuchi, Shinji; Kato, Kiyoko; Suga, Shin

2005-05-01

Previously, we found a significant reduction of progesterone receptor B (PR-B) expression levels in the Ras-mediated NIH3T3 cell transformation, and re-expression of exogenous PR-B eliminated the tumorigenic potential. We hypothesized that this reduction is of biological significance in cell transformation. In the present study, we determined the correlation between PR-B expression and cell cycle progression. In synchronized NIH3T3 cells, we found an increase in PR-B protein and p27 CDK inhibitor levels in the G0/G1 phase and a reduction due to redistribution in the S and G2/M phases. The MEK inhibitor or cAMP stimulation arrested NIH3T3 cells in the G0/G1 phasemore » of the cell cycle. The expression of PR-B and p27 CDK inhibitors was up-regulated by treatment with both the MEK inhibitor and cAMP. Treatment of synchronized cells with a PKA inhibitor in the presence of 1% calf serum resulted in a significant reduction in both PR-B and p27 levels. The decrease in the PR-B levels caused by anti-sense oligomers or siRNA corresponded to the reduction in p27 levels. PR-B overexpression by adenovirus infection induced p27 and suppressed cell growth. Finally, we showed that PR-B modulation involved in the regulation of NIH3T3 cell proliferation was independent of nuclear estrogen receptor (ER) activity but dependent on non-genomic ER activity.« less

Surface ozone in China: present-day distribution and long-term changes

NASA Astrophysics Data System (ADS)

Xu, X.; Lin, W.; Xu, W.

2017-12-01

Reliable knowledge of spatio-temporal variations of surface ozone is highly needed to assess the impacts of ozone on human health, ecosystem and climate. Although regional distributions and trends of surface ozone in European and North American countries have been well characterized, little is known about the variability of surface ozone in many other countries, including China, where emissions of ozone precursors have been changing rapidly in recent decades. Here we present the first comprehensive description of present-day (2013-2017) distribution and long-term changes of surface ozone in mainland China. Recent ozone measurements from China's air quality monitoring network (AQMN) are analyzed to show present-day distributions of a few ozone exposure metrics for urban environment. Long-term measurements of ozone at six background sites, a rural site and an urban are used to study the trends of ozone in background, rural and urban air, respectively. The average levels of ozone at the AQMN sites (mainly urban) are close to those found at many European and North American sites. However, ozone at most of the sites shows very large diurnal and seasonal variations so that ozone nonattainment can occur in many cities, particularly those in the North China Plain (NCP), the south of Northeast China (NEC), the Yangtze River Delta (YRD), the Pearl River Delta (PRD), and the Sichuan Basin-Chongqing region (SCB). In all these regions, particularly in the NCP, the maximum daily 8-h average (MDA8) ozone concentration can significantly exceed the national limit (75 ppb). High annual sum of ozone means over 35 ppb (SOMO35) exist mainly in the NCP, NEC and YRD, with regional averages over 4000 ppb·d. Surface ozone has significantly increased at Waliguan (a baseline site in western China) and Shangdianzi (a background site in the NCP), and decreased in winter and spring at Longfengshan (a background site in Northeast China). No clear trend can be derived from long-term measurements of ozone at other sites. Further attention should be paid to future changes of ozone in populated regions of China. Actions are urgently needed to control ozone pollution in the NCP and YRD.

78 FR 58383 - Senior Executive Service; Combined Performance Review Board (PRB)

Federal Register 2010, 2011, 2012, 2013, 2014

2013-09-23

... DEPARTMENT OF THE TREASURY United States Mint Senior Executive Service; Combined Performance Review Board (PRB) AGENCY: United States Mint (USM), Treasury. ACTION: Notice of members of Combined... Trade Bureau (TTB). The Combined PRB reviews the performance appraisals of career senior executives...

76 FR 63351 - Senior Executive Service; Financial Management Service Performance Review Board (PRB)

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-12

... DEPARTMENT OF THE TREASURY Senior Executive Service; Financial Management Service Performance Review Board (PRB) AGENCY: Financial Management Service, Treasury. ACTION: Notice. SUMMARY: This notice announces the appointment of members to the Financial Management Service (FMS) Performance Review Board (PRB...

77 FR 60177 - Senior Executive Service; Financial Management Service Performance Review Board (PRB)

Federal Register 2010, 2011, 2012, 2013, 2014

2012-10-02

... DEPARTMENT OF THE TREASURY Senior Executive Service; Financial Management Service Performance Review Board (PRB) AGENCY: Financial Management Service, Treasury. ACTION: Notice. SUMMARY: This notice announces the appointment of members to the Financial Management Service (FMS) Performance Review Board (PRB...

The Department of Education's Limits on Publications: Saving Money or Censorship? Sixtieth Report by the Committee on Government Operations together with Dissenting and Supplemental Views.

ERIC Educational Resources Information Center

Congress of the U. S., Washington, DC. House Committee on Government Operations.

This report discusses an oversight investigation of the Department of Education's Publication and Audio Visual Council (PAVAC) and its successor, the Publications Review Board (PRB). Background information is provided about the review process for publications and products; the Women's Educational Equity Act (WEEA) program; educational laboratories…

Chromium-removal processes during groundwater remediation by a zerovalent iron permeable reactive barrier.

PubMed

Wilkin, Richard T; Su, Chunming; Ford, Robert G; Paul, Cynthia J

2005-06-15

Solid-phase associations of chromium were examined in core materials collected from a full-scale, zerovalent iron permeable reactive barrier (PRB) at the U.S. Coast Guard Support Center located near Elizabeth City, NC. The PRB was installed in 1996 to treat groundwater contaminated with hexavalent chromium. After eight years of operation, the PRB remains effective at reducing concentrations of Cr from average values >1500 microg L(-1) in groundwater hydraulically upgradient of the PRB to values <1 microg L(-1) in groundwater within and hydraulically downgradient of the PRB. Chromium removal from groundwater occurs at the leading edge of the PRB and also within the aquifer immediately upgradient of the PRB. These regions also witness the greatest amount of secondary mineral formation due to steep geochemical gradients that result from the corrosion of zerovalent iron. X-ray absorption near-edge structure (XANES) spectroscopy indicated that chromium is predominantly in the trivalent oxidation state, confirming that reductive processes are responsible for Cr sequestration. XANES spectra and microscopy results suggest that Cr is, in part, associated with iron sulfide grains formed as a consequence of microbially mediated sulfate reduction in and around the PRB. Results of this study provide evidence that secondary iron-bearing mineral products may enhance the capacity of zerovalent iron systems to remediate Cr in groundwater, either through redox reactions at the mineral-water interface or by the release of Fe(II) to solution via mineral dissolution and/or metal corrosion.

Background ozone in North China: trends, photochemical and transport impacts

NASA Astrophysics Data System (ADS)

Xu, X.; Lin, W.; Ge, B.

2011-12-01

Tropospheric ozone is one of the key greenhouse gases and plays an important role in atmospheric chemistry. Being a strong oxidant, ozone in the surface layer has significant impacts on human and vegetation health. Long-term measurements of surface ozone are highly needed for climate change assessment and environmental policy-making. Such measurements are scarce, particularly from the background regions. Since 2004, surface ozone and some related reactive gases have been observed at Shangdianzi (SDZ), a Global Atmosphere Watch (GAW) station in North China. Located at the north edge of the Northern China Plain (NCP), the SDZ station is an ideal site for capturing polluted air masses from the NCP sector (southwest) and clean air masses from the background sector (northeast). This facilitates the investigation of impacts of regional transport on surface ozone. In this study, we present long-term measurements of surface ozone made at SDZ, discuss the trends of surface ozone levels in different seasons. Results about the observation-based ozone production efficiency (OPE) for the site will be presented, along with impacts from horizontal and vertical air transport.

Background ozone in North China: trends, photochemical and transport impacts

NASA Astrophysics Data System (ADS)

Xu, X.; Lin, W.; Ge, B.

2012-04-01

Tropospheric ozone is one of the key greenhouse gases and plays an important role in atmospheric chemistry. Being a strong oxidant, ozone in the surface layer has significant impacts on human and vegetation health. Long-term measurements of surface ozone are highly needed for climate change assessment and environmental policy-making. Such measurements are scarce, particularly from the background regions. Since 2004, surface ozone and some related reactive gases have been observed at Shangdianzi (SDZ), a Global Atmosphere Watch (GAW) station in North China. Located at the north edge of the Northern China Plain (NCP), the SDZ station is an ideal site for capturing polluted air masses from the NCP sector (southwest) and clean air masses from the background sector (northeast). This facilitates the investigation of impacts of regional transport on surface ozone. In this study, we present long-term measurements of surface ozone made at SDZ, discuss the trends of surface ozone levels in different seasons. Results about the observation-based ozone production efficiency (OPE) for the site will be presented, along with impacts from horizontal and vertical air transport.

GROUND WATER ARSENIC AND METALS TREATMENT USING A COMBINATION COMPOST-ZVI PRB (ABSTRACT ONLY)

EPA Science Inventory

A pilot permeable reactive barrier (PRB) consisting of a mixture of leaf compost, zero-valent iron (ZVI), limestone and pea gravel was installed at a former phosphate fertilizer manufacturing facility in Charleston, S.C. in September 2002. The PRB is designed to treat arsenic an...

Treatment of Arsenic, Heavy Metals, and Acidity Using a Mixed ZVI-Compost PRB

EPA Science Inventory

A 30-month performance evaluation of a pilot permeable reactive barrier (PRB) consisting of a mixture of leaf compost, zero-valent iron (ZVI), limestone and pea gravel installed at a former phosphate fertilizer manufacturing facility was conducted. The PRB is designed to remove ...

TREATMENT OF ARSENIC AND METALS IN GROUND WATER USING A COMPOST-ZVI PRB

EPA Science Inventory

A pilot permeable reactive barrier (PRB) consisting of a mixture of leaf compost, zero-valent iron (ZVI), limestone and pea gravel was installed at a former phosphate fertilizer manufacturing facility in Charleston, S.C. in September 2002. The PRB is designed to treat arsenic an...

GROUND WATER ARSENIC AND METALS TREATMENT USING A COMBINATION COMPOST-ZVI PRB

EPA Science Inventory

A pilot permeable reactive barrier (PRB) consisting of a mixture of leaf compost, zero-valent iron (ZVI), limestone and pea gravel was installed at a former phosphate fertilizer manufacturing facility in Charleston, S.C. in September 2002. The PRB is designed to treat arsenic an...

Hypoxia induces p53 accumulation in the S-phase and accumulation of hypophosphorylated retinoblastoma protein in all cell cycle phases of human melanoma cells.

PubMed Central

Danielsen, T.; Hvidsten, M.; Stokke, T.; Solberg, K.; Rofstad, E. K.

1998-01-01

Hypoxia has been shown to induce accumulation of p53 and of hypophosphorylated retinoblastoma protein (pRb) in tumour cells. In this study, the cell cycle dependence of p53 accumulation and pRb hypophosphorylation in four human melanoma cell lines that are wild type for p53 was investigated using two-parameter flow cytometry measurements of p53 or pRb protein content and DNA content. The hypoxia-induced increase in p53 protein was higher in S-phase than in G1 and G2 phases in all cell lines. The accumulation of p53 in S-phase during hypoxia was not related to hypoxia-induced apoptosis or substantial cell cycle specific cell inactivation during the first 24 h of reoxygenation. pRb was hypophosphorylated in all cell cycle phases by hypoxia treatment. The results did not support a direct link between p53 and pRb during hypoxia because p53 was induced in a cell cycle-specific manner, whereas no cell cycle-dependent differences in pRb hypophosphorylation were detected. Only a fraction of the cell populations (0.60+/-0.10) showed hypophosphorylated pRb. Thus, pRb is probably not the only mediator of the hypoxia-induced cell cycle block seen in all cells and all cell cycle phases. Moreover, the cell cycle-dependent induction of p53 by hypoxia suggests that the primary function of p53 accumulation during hypoxia is other than to arrest the cells. Images Figure 4 Figure 7 PMID:9862563

Analyzing the Impact of Refunding Postretirement Benefits other than Pensions (PRB) on Department of Defense Contracting

DTIC Science & Technology

1993-06-01

eligibles plus non-3ligibles equals total active employees) Several key concepts provide the foundation for SFAS 106 PRB accrual costs: Expected...will lump-together dependents and survivors along with current retirees in a category called simply "retirees". 40 EXHIBIT 8 PRB Acturial Assumptions a

APC/C and retinoblastoma interaction: cross-talk of retinoblastoma protein with the ubiquitin proteasome pathway.

PubMed

Ramanujan, Ajeena; Tiwari, Swati

2016-10-01

The ubiquitin (Ub) ligase anaphase promoting complex/cyclosome (APC/C) and the tumour suppressor retinoblastoma protein (pRB) play key roles in cell cycle regulation. APC/C is a critical regulator of mitosis and G1-phase of the cell cycle whereas pRB keeps a check on proliferation by inhibiting transition to the S-phase. APC/C and pRB interact with each other via the co-activator of APC/C, FZR1, providing an alternative pathway of regulation of G1 to S transition by pRB using a post-translational mechanism. Both pRB and FZR1 have complex roles and are implicated not only in regulation of cell proliferation but also in differentiation, quiescence, apoptosis, maintenance of chromosomal integrity and metabolism. Both are also targeted by transforming viruses. We discuss recent advances in our understanding of the involvement of APC/C and pRB in cell cycle based decisions and how these insights will be useful for development of anti-cancer and anti-viral drugs. © 2016 The Author(s).

APC/C and retinoblastoma interaction: cross-talk of retinoblastoma protein with the ubiquitin proteasome pathway

PubMed Central

Ramanujan, Ajeena; Tiwari, Swati

2016-01-01

The ubiquitin (Ub) ligase anaphase promoting complex/cyclosome (APC/C) and the tumour suppressor retinoblastoma protein (pRB) play key roles in cell cycle regulation. APC/C is a critical regulator of mitosis and G1-phase of the cell cycle whereas pRB keeps a check on proliferation by inhibiting transition to the S-phase. APC/C and pRB interact with each other via the co-activator of APC/C, FZR1, providing an alternative pathway of regulation of G1 to S transition by pRB using a post-translational mechanism. Both pRB and FZR1 have complex roles and are implicated not only in regulation of cell proliferation but also in differentiation, quiescence, apoptosis, maintenance of chromosomal integrity and metabolism. Both are also targeted by transforming viruses. We discuss recent advances in our understanding of the involvement of APC/C and pRB in cell cycle based decisions and how these insights will be useful for development of anti-cancer and anti-viral drugs. PMID:27402801

Binding of the fibronectin-mimetic peptide, PR_b, to α5β1 on pig islet cells increases fibronectin production and facilitates internalization of PR_b functionalized liposomes

PubMed Central

Atchison, Nicole A.; Fan, Wei; Papas, Klearchos K.; Hering, Bernhard J.; Tsapatsis, Michael; Kokkoli, Efrosini

2010-01-01

Islet transplantation is a promising treatment for type 1 diabetes. Recent studies have demonstrated that human islet allografts can restore insulin independence to patients with this disease. As islet isolation and immunotherapeutic techniques improve, the demand for this cell-based therapy will dictate the need for other sources of islets. Pig islets could provide an unlimited supply for xenotransplantation and have shown promise as an alternative to human islet allografts. However, stresses imposed during islet isolation and transplantation decrease islet viability, leading to loss of graft function. In this study, we investigated the ability of a fibronectin-mimetic peptide, PR_b, which specifically binds to the α5β1 integrin, to reestablish lost extracellular matrix (ECM) around isolated pig islets and increase internalization of liposomes. Confocal microscopy and western blotting were used to show the presence of the integrin α5β1 on the pig islets on day 0 (day of isolation), as well as different days of islet culture. Islets cultured in medium supplemented with free PR_b for 48 hours were found to have increased levels of ECM fibronectin secretion compared to islets in normal culture conditions. Using confocal microscopy and flow cytometry we found that PR_b peptide-amphiphile functionalized liposomes delivered to the pig islets internalized into the cells in a PR_b concentration dependent manner, and non-functionalized liposomes showed minimal internalization. These studies proved that the fibronectin-mimetic peptide, PR_b, is an appropriate peptide bullet for applications involving α5β1 expressing pig islet cells. Fibronectin production stimulated through α5β1 PR_b binding may decrease apoptosis and therefore increase islet viability in culture. In addition, PR_b peptide-amphiphile functionalized liposomes may be used for targeted delivery of different agents to pig islet cells. PMID:20704278

Emerging differential roles of the pRb tumor suppressor in trichodysplasia spinulosa-associated polyomavirus and Merkel cell polyomavirus pathogeneses.

PubMed

Wu, Julie H; Simonette, Rebecca A; Nguyen, Harrison P; Doan, Hung Q; Rady, Peter L; Tyring, Stephen K

2016-03-01

Merkel cell carcinoma (MCC) and trichodysplasia spinulosa (TS) are two proliferative cutaneous diseases caused by the Merkel cell polyomavirus (MCPyV) and trichodysplasia spinulosa-associated polyomavirus (TSPyV) respectively. Recently, studies have elucidated a key role of the small tumor (sT) antigen in the proliferative pathogenic mechanisms of MCPyV and likely TSPyV. While both sT antigens have demonstrated a capacity in regulating cellular pathways, it remains unknown whether MCPyV and TSPyV sT antigens contribute similarly or differentially to cell proliferation. The present study aims to explore the proliferative potential of MCPyV and TSPyV sT antigens by investigating their regulatory effects on the retinoblastoma protein (pRb) tumor suppressor. Inducible cell lines expressing MCPyV sT or TSPyV sT were created using a lentiviral packaging system. Cellular proteins were extracted and subjected to SDS-PAGE followed by Western blot detection and densitometric analysis. Expression of TSPyV sT markedly enhanced the phosphorylation of pRb in Western blot experiments. In contrast, expression of MCPyV sT did not alter pRb phosphorylation under the same experimental conditions. Densitometric analysis revealed that TSPyV sT antigen expression nearly doubled the ratio of phosphorylated to total pRb (P<0.001, Student's T-test), while MCPyV sT antigen expression did not cause significant change in pRb phosphorylation status. Given that hyperphosphorylation of pRb is associated with dysregulation of the cell cycle, S-phase induction, and increased cell proliferation, our findings support an important role of TSPyV-mediated pRb deactivation in the development of TS. The observation that the pRb tumor suppressor is inactivated by TSPyV sT but not MCPyV sT provides further insights into the distinct pathobiological mechanisms of MCC and TS. Copyright © 2016 Elsevier B.V. All rights reserved.

Investigation of Contaminated Ground Water at Solid Waste Management Unit 12, Naval Weapons Station Charleston, North Charleston, South Carolina, 2006-2007

USGS Publications Warehouse

Vroblesky, Don A.; Petkewich, Matthew D.; Lowery, Mark A.; Conlon, Kevin J.; Harrelson, Larry G.

2008-01-01

The U.S. Geological Survey investigated natural and engineered remediation of chlorinated volatile organic compound (VOC) ground-water contamination at Solid Waste Management Unit 12 at the Naval Weapons Station Charleston, North Charleston, South Carolina, beginning in 2000. The primary contaminants of interest in the study are tetrachloroethene, 1,1,1-trichloroethane, trichloroethene, cis-1,2-dichloroethene, vinyl chloride, 1,1-dichloroethane, and 1,1-dichloroethene. The permeable reactive barrier (PRB) along the main axis of the contaminant plume appears to be actively removing contamination. In contrast to the central area of the PRB, the data from the southern end of the PRB indicate that contaminants are moving around the PRB. Concentrations in wells 12MW-10S and 12MW-03S, upgradient from the PRB, showed a general decrease in VOC concentrations. VOC concentrations in some wells in the forest showed a sharp increase, followed by a decrease. In 2007, the VOC concentrations began to increase in well 12MW-12S, downgradient from the PRB and thought to be unaffected by the PRB. The VOC-concentration changes in the forest, such as at well 12MW-12S, may represent lateral shifting of the plume in response to changes in ground-water-flow direction or may represent movement of a contamination pulse through the forest.

CARBON-BASED REACTIVE BARRIER FOR NITRATE ...

EPA Pesticide Factsheets

Nitrate (NO3-) is a common ground water contaminant related to agricultural activity, waste water disposal, leachate from landfills, septic systems, and industrial processes. This study reports on the performance of a carbon-based permeable reactive barrier (PRB) that was constructed for in-situ bioremediation of a ground water nitrate plume caused by leakage from a swine CAFO (concentrated animal feeding operation) lagoon. The swine CAFO, located in Logan County, Oklahoma, was in operation from 1992-1999. The overall site remediation strategy includes an ammonia recovery trench to intercept ammonia-contaminated ground water and a hay straw PRB which is used to intercept a nitrate plume caused by nitrification of sorbed ammonia. The PRB extends approximately 260 m to intercept the nitrate plume. The depth of the trench averages 6 m and corresponds to the thickness of the surficial saturated zone; the width of the trench is 1.2 m. Detailed quarterly monitoring of the PRB began in March, 2004, about 1 year after construction activities ended. Nitrate concentrations hydraulically upgradient of the PRB have ranged from 23 to 77 mg/L N, from 0 to 3.2 mg/L N in the PRB, and from 0 to 65 mg/L N hydraulically downgradient of the PRB. Nitrate concentrations have generally decreased in downgradient locations with successive monitoring events. Mass balance considerations indicate that nitrate attenuation is dominantly from denitrification but with some component of

Effect of nitrate, acetate and hydrogen on native perchlorate-reducing microbial communities and their activity in vadose soil

PubMed Central

Nozawa-Inoue, Mamie; Jien, Mercy; Yang, Kun; Rolston, Dennis E.; Hristova, Krassimira R.; Scow, Kate M.

2011-01-01

Effect of nitrate, acetate and hydrogen on native perchlorate-reducing bacteria (PRB) was examined by conducting microcosm tests using vadose soil collected from a perchlorate-contaminated site. The rate of perchlorate reduction was enhanced by hydrogen amendment and inhibited by acetate amendment, compared to unamendment. Nitrate was reduced before perchlorate in all amendments. In hydrogen-amended and unamended soils, nitrate delayed perchlorate reduction, suggesting the PRB preferentially use nitrate as an electron acceptor. In contrast, nitrate eliminated the inhibitory effect of acetate amendment on perchlorate reduction and increased the rate and the extent, possibly because the preceding nitrate reduction/denitrification decreased the acetate concentration which was inhibitory to the native PRB. In hydrogen-amended and unamended soils, perchlorate reductase gene (pcrA) copies, representing PRB densities, increased with either perchlorate or nitrate reduction, suggesting either perchlorate or nitrate stimulates growth of the PRB. In contrast, in acetate-amended soil pcrA increased only when perchlorate was depleted: a large portion of the PRB may have not utilized nitrate in this amendment. Nitrate addition did not alter the distribution of the dominant pcrA clones in hydrogen-amended soil, likely because of the functional redundancy of PRB as nitrate-reducers/denitrifiers, whereas acetate selected different pcrA clones from those with hydrogen amendment. PMID:21284679

Increased progesterone receptor expression in uterine leiomyoma: correlation with age, number of leiomyomas, and clinical symptoms.

PubMed

Tsigkou, Anastasia; Reis, Fernando M; Lee, Meng H; Jiang, Bingjie; Tosti, Claudia; Centini, Gabriele; Shen, Fang-Rong; Chen, You-Guo; Petraglia, Felice

2015-07-01

To investigate the possible correlation between progesterone receptor (PR) expression in uterine leiomyoma or adjacent myometrium and patient's age, size/number of leiomyomas, or clinical symptoms such as dysmenorrhea, acyclic pelvic pain, or menstrual and intermenstrual uterine bleeding. Cross-sectional study. Referral center. Sixty-two Chinese women undergoing elective hysterectomy for uterine leiomyomata. None. Evaluation of PR-total and PR-B mRNA with real-time polymerase chain reaction; PR-A and PR-B proteins quantified by Western blot in leiomyoma tissue and myometrium; symptoms rated by the patients using visual analog scores. The PR-B mRNA and PR-A and PR-B proteins were more concentrated in leiomyomas than in matched myometrium. A direct correlation between PR-B mRNA levels in leiomyoma and age (r = 0.347) and number of tumors (r = 0.295) was found. Conversely, there was an inverse correlation between PR-B mRNA levels in leiomyoma and dysmenorrhea (r = -0.260) and intermenstrual bleeding (r = -0.266). Multiple regression analysis indicated that age (β = 0.363) and the number of myomas (β = 0.296) were independently associated with PR-B mRNA levels in leiomyoma tissue. The levels of PR-B mRNA in leiomyoma tissue are directly associated with the number of tumors and inversely correlated with the intensity of intermenstrual bleeding and dysmenorrhea, suggesting that PR signaling may favor leiomyoma growth while attenuating clinical symptoms. This duality should be taken into account in the clinical management of patients with symptomatic uterine leiomyoma. Copyright © 2015 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

Detrital Thermochronology Record of the Local-to-Extraregional Provenance Shift Recorded by the Northern Peninsular Ranges Forearc

NASA Astrophysics Data System (ADS)

Flores, M.; Shulaker, D. Z.

2016-12-01

Previously measured detrital zircon U-Pb age distributions have revealed that Late Cretaceous to Eocene forearc strata in the Santa Ana mountains region experienced a dramatic shift in sedimentary provenance from a 125-90 Ma northern Peninsular Ranges batholith (PRB) source region along the continental margin to a cratonal source area intruded by Late Cretaceous (85-75 Ma) plutons within the continental interior (western Sonora). To improve our understanding of the timing and magnitude of denudation prior to, and during this local to extraregional provenance shift, we have measured new detrital K-feldspar 40Ar/39Ar total fusion and zircon U-Pb age distributions from forearc sandstones. Our combined crystallization age and thermal history results confirm two pulses of rapid denudation of the PRB. These include a syn-batholith phase (Cenomanian) and a post-batholithic (Maastrichtian to Paleocene) phase attributed to shallow subduction. The new data require that significant (5-10 km) syn-batholithic erosional denudation of the northern PRB had already occurred by ca. 95 Ma and that post-emplacement denudation of the PRB accelerated again during the Maastrichtian with the eastern PRB providing the bulk of the detritus. Our new results demonstrate that deposition of the Paleocene Silverado Fm. occurred during a transitional period. Sand reaching the forearc during the Paleocene was derived from both the heavily denuded eastern PRB with additional input supplied either from Late Cretaceous plutons of northwestern Sonoran region and/or similar plutons emplaced in thrust sheets atop PRB basement within the Santa Rosa Mountains. In contrast, the Eocene Santiago Fm. was nearly entirely derived from extraregional sources that supplied abundant late Cretaceous (75-85 Ma) and Proterozoic (1.4 & 1.7 Ga) detritus with virtually no PRB-derived sediment detected.

Remediation of nitrate-contaminated groundwater by PRB-Electrokinetic integrated process.

PubMed

Ghaeminia, Mahdyar; Mokhtarani, Nader

2018-05-30

Activated carbon is used as a reactive media in Permeable Reactive Barrier (PRB) for the removal of inorganic contaminants such as nitrate from groundwater. Since removal rate by this media decreases by time and due to the high costs of excavation and replacement of new media, the usage of activated carbon as an adsorbent in PRB is limited. The present study aimed to solve this defect by integrating electrokinetic process and PRB, using in-situ regeneration of activated carbon. This research was carried out on a laboratory scale using synthetically contaminated water and modified activated carbon as a reactive media in PRB. The effects of pH, nitrate concentration, carbon to sand ratio, and also electric gradient on the performance of the process were evaluated, and optimal conditions were determined, to increase the system longevity. According to the results, by applying an electric gradient of 1.25 V cm -1 to the PRB alone process in optimum operating condition (135 mg L -1 initial nitrate concentration, flow rate of 2.3 L min -1 , pH = 6.8, and carbon to sand ratios of 1:1) the adsorbent capacity increased by 90%. Under these conditions, the integrated process could keep nitrate concentration in the effluent below the standard limit for about 111 h, while the PRB alone process could do the same job for about 59 h. Also, SEM analysis showed that by applying electrokinetic process, activated carbon was regenerated. Integration of electrokinetic process and PRB was also caused nitrate to transfer from activated carbon media into the soil layer above the system. This nitrate-rich soil has the potential for reuse in agricultural activities. Copyright © 2018 Elsevier Ltd. All rights reserved.

Active FOXO1 is a Key Determinant of Isoform-Specific Progesterone Receptor Transactivation and Senescence Programming

PubMed Central

Diep, Caroline H.; Knutson, Todd P.; Lange, Carol A.

2015-01-01

Progesterone promotes differentiation coupled to proliferation and pro-survival in the breast, but inhibits estrogen-driven growth in the reproductive tract and ovaries. Herein, it is demonstrated, using progesterone receptor (PR) isoform-specific ovarian cancer model systems, that PR-A and PR-B promote distinct gene expression profiles that differ from PR-driven genes in breast cancer cells. In ovarian cancer models, PR-A primarily regulates genes independently of progestin, while PR-B is the dominant ligand-dependent isoform. Notably, FOXO1 and the PR/FOXO1 target-gene p21 (CDKN1A) are repressed by PR-A, but induced by PR-B. In the presence of progestin, PR-B, but not PR-A, robustly induced cellular senescence via FOXO1-dependent induction of p21 and p15 (CDKN2B). Chromatin immunoprecipitation (ChIP) assays performed on PR-isoform specific cells demonstrated that while each isoform is recruited to the same PRE-containing region of the p21 promoter in response to progestin, only PR-B elicits active chromatin marks. Overexpression of constitutively active FOXO1 in PR-A-expressing cells conferred robust ligand-dependent upregulation of the PR-B target genes GZMA, IGFBP1, and p21, and induced cellular senescence. In the presence of endogenous active FOXO1, PR-A was phosphorylated on Ser294 and transactivated PR-B at PR-B target genes; these events were blocked by the FOXO1 inhibitor (AS1842856). PR isoform-specific regulation of the FOXO1/p21 axis recapitulated in human primary ovarian tumor explants treated with progestin; loss of progestin sensitivity correlated with high AKT activity. PMID:26577046

Linking field and laboratory studies to investigate nitrate removal using permeable reactive barrier technology during managed recharge

NASA Astrophysics Data System (ADS)

Gorski, G.; Beganskas, S.; Weir, W. B.; Redford, K.; Saltikov, C.; Fisher, A. T.

2017-12-01

We present data from a series of field and laboratory studies investigating mechanisms for the enhanced removal of nitrate during infiltration as a part of managed recharge. These studies combine physical, geochemical, and microbiological data collected during controlled infiltration experiments at both a plot and a laboratory scale using permeable reactive barrier (PRB) technology. The presence of a PRB, made of wood chips or biochar, enhances nitrate removal by stimulating the growth and productivity of native soil microbes to process nitrate via denitrification. Earlier work has shown that unamended soil can remove up to 50% of nitrate during infiltration at rates <1 m/day, but at higher infiltration rates nitrate removal dramatically decreases as too much oxygen is introduced, and the necessary conditions for denitrification do not develop. Our plot scale studies show that up to 40% of incoming nitrate can consistently be removed even at infiltration rates ≥1 m/day if there is a PRB made of wood chips. Slightly less nitrate is removed in the presence of a biochar PRB and there is little to no change in nitrate concentration at similarly high infiltration rates through unamended soil. Preliminary microbiological data show significant population changes below the PRB where most of the cycling occurs. Coupled with isotopic analyses, these results suggest that a PRB expands the range of infiltration rates at which significant nitrate can be removed by microbial activity. Further, nitrate removal occurs at different depths below the biochar and redwood chips, suggesting different mechanisms of nitrate removal in the presence of different PRB materials. In laboratory studies we flowed artificial groundwater through intact sediment cores collected at the same field site where we also ran infiltration tests. These experiments show that the fluid flow rate and the presence of a PRB exhibit primary control on nitrate removal during infiltration, and that the relationship between flow rate and nitrate removal is fundamentally different in the presence of a PRB. These data from multiple scales and flow regimes are combined to offer a deeper understanding how the use of PRB technology during infiltration can help address a significant non-point source issue at the surface-subsurface interface.

Abundance and Localization of Progesterone Receptor Isoforms in Endometrium in Women With and Without Endometriosis and in Peritoneal and Ovarian Endometriotic Implants

PubMed Central

Bedaiwy, Mohamed A.; Dahoud, Wissam; Skomorovska-Prokvolit, Yelena; Yi, Lijuan; Liu, James H.; Falcone, Tommaso; Hurd, William W.; Mesiano, Sam

2015-01-01

Background: Several studies suggest that resistance to progesterone may contribute to the pathophysiology of endometriosis. Progesterone mediates its biological activity via the 2 progesterone receptor (PR) isoforms (PR-A and PR-B). Effects of progesterone are determined by the PR-A:PR-B ratio such that a PR-B-dominant state promotes progesterone signaling, whereas a PR-A-dominant state decreases progesterone responsiveness. Our objective was to compare the abundance and cellular localization of the PR isoforms in endometrium and endometriotic lesions from women with and without peritoneal and ovarian endometriosis. Methods: This in vitro study was conducted in a tertiary care facility. Reproductive-age women with surgically diagnosed endometriosis (n = 18) and asymptomatic control individuals (n = 20) were prospectively recruited at the late proliferative and the early secretory phases. At laparoscopy, samples of eutopic endometrium, peritoneal and ovarian endometriosis, and disease-free peritoneum were obtained for subsequent immunohistochemical and immunoblot analysis of PR-B and total PR localization and PR-A and PR-B abundance, respectively. Results: The PR-A and PR-B were detected in eutopic endometrium and in peritoneal and ovarian endometriosis but not in disease-free peritoneum from patients with and without endometriosis. In peritoneal endometriosis, PR-A was the predominant isoform detected, whereas both receptors were detected in ovarian endometriosis and eutopic endometrium. In eutopic endometrium, levels of PR-A were significantly elevated in women with endometriosis compared with women without disease, regardless of menstrual phase. The PR-A levels were significantly elevated in ovarian endometriosis compared with peritoneal endometriosis. Conclusions: Endometriotic lesions and eutopic endometrium from women with endometriosis are uniform in a PR-A-dominant state. The data suggest that menstrual efflux of a PR-A-dominant endometrial tissue into the peritoneal cavity may play a role in the pathophysiology of endometriosis. PMID:26037298

Sonic hedgehog initiates cochlear hair cell regeneration through downregulation of retinoblastoma protein

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

Lu, Na; Department of Otolaryngology and Program in Neuroscience, Harvard Medical School and Eaton Peabody Laboratory, Massachusetts Eye and Ear Infirmary, Boston, MA 02114; Chen, Yan

Highlights: Black-Right-Pointing-Pointer Shh activation in neonatal cochleae enhances sensory cell proliferation. Black-Right-Pointing-Pointer Proliferating supporting cells can transdifferentiate into hair cells. Black-Right-Pointing-Pointer Shh promotes proliferation by transiently modulating pRb activity. Black-Right-Pointing-Pointer Shh inhibits pRb by inhibiting transcription and increasing phosphorylation of pRb. -- Abstract: Cell cycle re-entry by cochlear supporting cells and/or hair cells is considered one of the best approaches for restoring hearing loss as a result of hair cell damage. To identify mechanisms that can be modulated to initiate cell cycle re-entry and hair cell regeneration, we studied the effect of activating the sonic hedgehog (Shh) pathway. We showmore » that Shh signaling in postnatal rat cochleae damaged by neomycin leads to renewed proliferation of supporting cells and hair cells. Further, proliferating supporting cells are likely to transdifferentiate into hair cells. Shh treatment leads to inhibition of retinoblastoma protein (pRb) by increasing phosphorylated pRb and reducing retinoblastoma gene transcription. This results in upregulation of cyclins B1, D2, and D3, and CDK1. These results suggest that Shh signaling induces cell cycle re-entry in cochlear sensory epithelium and the production of new hair cells, in part by attenuating pRb function. This study provides an additional route to modulate pRb function with important implications in mammalian hair cell regeneration.« less

Analysis of European ozone trends in the period 1995-2014

NASA Astrophysics Data System (ADS)

Yan, Yingying; Pozzer, Andrea; Ojha, Narendra; Lin, Jintai; Lelieveld, Jos

2018-04-01

Surface-based measurements from the EMEP and Airbase networks are used to estimate the changes in surface ozone levels during the 1995-2014 period over Europe. We find significant ozone enhancements (0.20-0.59 µg m-3 yr-1 for the annual means; P-value < 0.01 according to an F-test) over the European suburban and urban stations during 1995-2012 based on the Airbase sites. For European background ozone observed at EMEP sites, it is shown that a significantly decreasing trend in the 95th percentile ozone concentrations has occurred, especially at noon (0.9 µg m-3 yr-1; P-value < 0.01), while the 5th percentile ozone concentrations continued to increase with a trend of 0.3 µg m-3 yr-1 (P-value < 0.01) during the study period. With the help of numerical simulations performed with the global chemistry-climate model EMAC, the importance of anthropogenic emissions changes in determining these changes over background sites are investigated. The EMAC model is found to successfully capture the observed temporal variability in mean ozone concentrations, as well as the contrast in the trends of 95th and 5th percentile ozone over Europe. Sensitivity simulations and statistical analysis show that a decrease in European anthropogenic emissions had contrasting effects on surface ozone trends between the 95th and 5th percentile levels and that background ozone levels have been influenced by hemispheric transport, while climate variability generally regulated the inter-annual variations of surface ozone in Europe.

Effects of the Bermuda High and the Great Plains low-level jet upon background and peak ozone concentrations in Texas urban areas

NASA Astrophysics Data System (ADS)

Estes, M. J.; Wang, Y.; Lei, R.; Wang, S. C.; Jia, B.

2017-12-01

Previous studies have established that the westward extent of the Bermuda High is strongly linked to the ozone concentrations in Houston. This study examines the linkages between the Bermuda High, the Great Plains low-level jet, background ozone in the eastern half of Texas, and local contributions to peak ozone in Texas urban areas. Analysis of North American Regional Reanalysis (NARR) wind and pressure fields will be used to establish the presence and strength of synoptic-scale weather features, and this information will be used with ozone data from air quality networks to determine the effects upon the seasonal and interannual variations of ozone. Quantification of the effects of large-scale meteorological factors will improve understanding of the causes of ozone variations, including decadal trends in Texas cities.

Dissociation of retinoblastoma gene protein hyperphosphorylation and commitment to enter S phase.

PubMed Central

Ogryzko, V V; Hirai, T H; Shih, C E; Howard, B H

1994-01-01

Mitogenic activities of simian virus 40 large T and small t antigens were studied in serum-deprived human diploid fibroblasts. Wild-type large T and small t cooperated in stimulating DNA synthesis and in inducing hyperphosphorylation of the Rb gene product (pRb). In contrast, a T antigen mutant defective for pRb binding (Rb- T) possessed no detectable mitogenic activity alone and failed to complement small t in stimulating DNA synthesis. Surprisingly, Rb- T and small t cooperated as strongly as wild-type T and small t with respect to pRb hyperphosphorylation. As a consequence, in two closely related conditions (i.e., stimulation by small t plus wild-type T versus small t plus Rb- T), the fraction of pRb in hyperphosphorylated forms dissociated from the fraction of cells in the S phase. These results indicate that pRb hyperphosphorylation is not always tightly coupled with a commitment to initiate DNA replication. Images PMID:8189510

Tracking Continental Scale Background Ozone with CMAQ

EPA Science Inventory

As the National Ambient Air Quality Standards (NAAQS) for ozone become more stringent, there has been growing attention on characterizing the contributions and the uncertainties in ozone from outside the US to the ozone concentrations within the US. Modeling techniques readily av...

Whole-exome sequencing reveals novel mutations and epigenetic regulation in hypopharyngeal carcinoma

PubMed Central

Wu, Ping; Wu, Honglong; Tang, Yaoyun; Luo, Shi; Fang, Xing; Xie, Chubo; He, Jian; Zhao, Suping; Wang, Xiaofeng; Xu, Jiajia; Chen, Xi; Li, Dongfang; Yang, Huanming; Wang, Jian

2017-01-01

Hypopharyngeal cancer (HPC) frequently presents at an advanced stage, resulting in poor prognosis. Although combined surgical therapy and chemoradiotherapy have improved the survival for patients with HPC over the past 3 decades, the mortality rate in late-stage diagnosis of HPC is unsatisfactory. In this study, we performed whole-exome sequencing (WES) of 23 hypopharyngeal tumor and paired adjacent normal tissue to identify novel candidate driver genes associated with hypopharyngeal carcinoma. We identified several copy number variants (CNVs) and 15 somatic mutation genes that were associated with hypopharyngeal carcinoma. Mutations in nine new genes (PRB4, NSD1, REC8, ZNF772, ZNF69, EI24, CYFIP2, NEFH, KRTAP4-5) were also indentified. PRB4 and NSD1 expression were significantly upregulated in hypopharyngeal carcinoma, which was confirmed in an independent cohort using IHC. There was a positive relationship between PRB4 and NSD1. Downregulation of PRB4 by siRNA could inhibit cell growth, colony formation and cell invasion. Notably, we here demonstrate that NSD1 could bind to the promoter regions of PRB4 and activate promoter activity by reducing the binding of H3K27me2 and increasing the binding of H3K36me2 on PRB4 promoter. In summary, we pinpoint the predominant mutations in hypopharyngeal carcinoma by WES, highlighting the substantial genetic alterations contributing to hypopharyngeal carcinoma tumorigenesis. We also indentify a novel epigenetically regulatory between PRB4 and NSD1 that contribute to hypopharyngeal carcinoma tumorigenesis. They may become potential prognostic biomarkers and therapeutic target for hypopharyngeal carcinoma treatment. PMID:29156722

Monitoring trichloroethene remediation at an iron permeable reactive barrier using stable carbon isotopic analysis

NASA Astrophysics Data System (ADS)

VanStone, Nancy; Przepiora, Andrzej; Vogan, John; Lacrampe-Couloume, Georges; Powers, Brian; Perez, Ernesto; Mabury, Scott; Sherwood Lollar, Barbara

2005-08-01

Stable carbon isotopic analysis, in combination with compositional analysis, was used to evaluate the performance of an iron permeable reactive barrier (PRB) for the remediation of ground water contaminated with trichloroethene (TCE) at Spill Site 7 (SS7), F.E. Warren Air Force Base, Wyoming. Compositional data indicated that although the PRB appeared to be reducing TCE to concentrations below treatment goals within and immediately downgradient of the PRB, concentrations remained higher than expected at wells further downgradient (i.e. > 9 m) of the PRB. At two wells downgradient of the PRB, TCE concentrations were comparable to upgradient values, and δ13C values of TCE at these wells were not significantly different than upgradient values. Since the process of sorption/desorption does not significantly fractionate carbon isotope values, this suggests that the TCE observed at these wells is desorbing from local aquifer materials and was present before the PRB was installed. In contrast, three other downgradient wells show significantly more enriched δ13C values compared to the upgradient mean. In addition, δ13C values for the degradation products of TCE, cis-dichloroethene and vinyl chloride, show fractionation patterns expected for the products of the reductive dechlorination of TCE. Since concentrations of both TCE and degradation products drop to below detection limit in wells within the PRB and directly below it, these downgradient chlorinated hydrocarbon concentrations are attributed to desorption from local aquifer material. The carbon isotope values indicate that this dissolved contaminant is subject to local degradation, likely due to in situ microbial activity.

Monitoring trichloroethene remediation at an iron permeable reactive barrier using stable carbon isotopic analysis.

PubMed

VanStone, Nancy; Przepiora, Andrzej; Vogan, John; Lacrampe-Couloume, Georges; Powers, Brian; Perez, Ernesto; Mabury, Scott; Sherwood Lollar, Barbara

2005-08-01

Stable carbon isotopic analysis, in combination with compositional analysis, was used to evaluate the performance of an iron permeable reactive barrier (PRB) for the remediation of ground water contaminated with trichloroethene (TCE) at Spill Site 7 (SS7), F.E. Warren Air Force Base, Wyoming. Compositional data indicated that although the PRB appeared to be reducing TCE to concentrations below treatment goals within and immediately downgradient of the PRB, concentrations remained higher than expected at wells further downgradient (i.e. >9 m) of the PRB. At two wells downgradient of the PRB, TCE concentrations were comparable to upgradient values, and delta13C values of TCE at these wells were not significantly different than upgradient values. Since the process of sorption/desorption does not significantly fractionate carbon isotope values, this suggests that the TCE observed at these wells is desorbing from local aquifer materials and was present before the PRB was installed. In contrast, three other downgradient wells show significantly more enriched delta13C values compared to the upgradient mean. In addition, delta13C values for the degradation products of TCE, cis-dichloroethene and vinyl chloride, show fractionation patterns expected for the products of the reductive dechlorination of TCE. Since concentrations of both TCE and degradation products drop to below detection limit in wells within the PRB and directly below it, these downgradient chlorinated hydrocarbon concentrations are attributed to desorption from local aquifer material. The carbon isotope values indicate that this dissolved contaminant is subject to local degradation, likely due to in situ microbial activity.

Permeable Reactive Barriers Designed To Mitigate Eutrophication Alter Bacterial Community Composition and Aquifer Redox Conditions

PubMed Central

Hiller, Kenly A.; Foreman, Kenneth H.; Weisman, David

2015-01-01

Permeable reactive barriers (PRBs) consist of a labile carbon source that is positioned to intercept nitrate-laden groundwater to prevent eutrophication. Decomposition of carbon in the PRB drives groundwater anoxic, fostering microbial denitrification. Such PRBs are an ideal habitat to examine microbial community structure under high-nitrate, carbon-replete conditions in coastal aquifers. We examined a PRB installed at the Waquoit Bay National Estuarine Research Reserve in Falmouth, MA. Groundwater within and below the PRB was depleted in oxygen compared to groundwater at sites upgradient and at adjacent reference sites. Nitrate concentrations declined from a high of 25 μM upgradient and adjacent to the barrier to <0.1 μM within the PRB. We analyzed the total and active bacterial communities filtered from groundwater flowing through the PRB using amplicons of 16S rRNA and of the 16S rRNA genes. Analysis of the 16S rRNA genes collected from the PRB showed that the total bacterial community had high relative abundances of bacteria thought to have alternative metabolisms, such as fermentation, including candidate phyla OD1, OP3, TM7, and GN02. In contrast, the active bacteria had lower abundances of many of these bacteria, suggesting that the bacterial taxa that differentiate the PRB groundwater community were not actively growing. Among the environmental variables analyzed, dissolved oxygen concentration explained the largest proportion of total community structure. There was, however, no significant correlation between measured environmental parameters and the active microbial community, suggesting that controls on the active portion may differ from the community as a whole. PMID:26231655

Investigation of Contaminated Groundwater at Solid Waste Management Unit 12, Naval Weapons Station Charleston, North Charleston, South Carolina, 2008

USGS Publications Warehouse

Vroblesky, Don A.; Petkewich, Matthew D.

2009-01-01

The U.S. Geological Survey and the Naval Facilities Engineering Command Southeast investigated natural and engineered remediation of chlorinated volatile organic compound (VOC) groundwater contamination at Solid Waste Management Unit 12 at the Naval Weapons Station Charleston, North Charleston, South Carolina, beginning in 2000. The primary contaminants of interest in the study are tetrachloroethene, 1,1,1-trichloroethane, trichloroethene, cis-1,2-dichloroethene, vinyl chloride, 1,1-dichloroethane, and 1,1-dichloroethene. Engineered remediation aspects at the site consist of a zero-valent-iron permeable reactive barrier (PRB) installed in December 2002 intercepting the contamination plume and a phytoremediation test stand of loblolly pine trees planted in the source area in May 2003. The U.S. Geological Survey planted an additional phytoremediation test stand of loblolly pine trees on the upgradient side of the southern end of the PRB in February 2008. At least once during the summer, however, the trees were inadvertently mowed during lawn cutting activity. The PRB along the main axis of the contaminant plume appears to be actively removing contamination. In contrast to the central area of the PRB, the data from the southern end of the PRB indicate that contaminants are moving around the PRB. Concentrations in wells upgradient from the PRB showed a general decrease in VOC concentrations. VOC concentrations in some wells in the forest downgradient from the PRB showed a sharp increase in 2005, followed by a decrease in 2006. Farther downgradient in the forest, the VOC concentrations began to increase in 2007 and continued to increase into 2008. The VOC-concentration changes in groundwater beneath the forest appear to indicate movement of a groundwater-contaminant pulse through the forest. It also is possible that the data may represent lateral shifting of the plume in response to changes in groundwater-flow direction.

Water quality impacts of hydraulic-fracturing chemicals observed in a permeable, quartz-sand aquifer

NASA Astrophysics Data System (ADS)

Kent, D. B.; LeBlanc, D. R.; Smith, R. L.

2012-12-01

A pilot scale experiment was conducted on western Cape Cod, Massachusetts to test the use of hydraulic fracturing (HF) for emplacing permeable reactive barriers (PRB) where the water table is too far below land surface to use standard excavation methods. Two PRB were emplaced 24 to 36 meters below land surface in a plume with low concentrations of perchloroethylene in oxic, mildly acidic groundwater with low concentrations of dissolved salts. The granular aquifer sediments consist of permeable sands and gravels. Quartz comprises greater than 90% by weight of the aquifer sediments but chemical reactivity of the sediments is controlled by micrometer-scale chlorite and illite and nanometer-scale aluminum-substituted goethite. HF fluids contained guar gum (gelling agent), cellulose enzyme and acetic acid (breakers), sodium borate (cross-linker), potassium (K) carbonate (pH adjustor), and sodium (Na) chloride (tracer). Water-quality impacts within about 20 meters of the PRB were monitored over a 1.7-year period following HF. Arrival of HF-chemicals was marked by an increase in boron (B) from ambient concentrations of 6 uM to >800 uM. B concentrations rose for approximately 50 days, much longer than the 22-day period over which HF was conducted. B concentrations subsequently decreased but remained 2-3 times above background concentrations for almost one year. Elevated Na and K concentrations in the HF fluids drove sorption (including ion exchange) reactions resulting in transient increases in naturally occurring major, minor, and trace cations up to 20 to 50 times background concentrations. Increases in dissolved organic carbon (DOC) and decreases in dissolved oxygen (DO) concentrations were observed as B concentrations increased. DOC concentration subsequently decreased but remained significantly above background. DO concentrations remained below detection. Dissolved iron (Fe) and manganese (Mn) concentrations increased as DO concentrations decreased below detection and remained elevated 1.7 years after HF. Reactions with Fe in the PRB may have contributed to the observed Fe concentrations but Mn was likely released from the aquifer sediments. Fe and Mn concentrations remained elevated throughout the sampling period. Dissolved arsenic concentrations increased after anaerobic conditions were established from below detection to 0.3-0.5 uM. HF fluids contained only a subset of the chemicals used in typical HF stimulations and aquifer sediments were likely less reactive than aquifer solids at other sites. Despite these differences, several findings have applicability to other sites. B is a potentially useful tracer of intrusion of HF fluids into aquifers, but elevated concentrations may be short-lived. Sorption reactions driven by differences in dissolved salt concentrations between HF fluids and ambient groundwater result in changes in cation concentrations, including barium and strontium. Organic compounds in HF fluids may drive aerobic aquifers anaerobic. Anaerobic conditions may lead to mobilization of naturally occurring contaminants like arsenic, whose reduced forms are more mobile than oxidized forms.

Differences in proximal (cardia) versus distal (antral) gastric carcinogenesis via retinoblastoma pathway

PubMed Central

Gulmann, Christian; Hegarty, Helen; Grace, Antoinette; Leader, Mary; Patchett, Stephen; Kay, Elaine

2004-01-01

AIM: Disruption of cell cycle regulation is a critical event in carcinogenesis, and alteration of the retinoblastoma (pRb) tumour suppressor pathway is frequent. The aim of this study was to compare alterations in this pathway in proximal and distal gastric carcinogenesis in an effort to explain the observed striking epidemiological differences. METHODS: Immunohistochemistry was performed to investigate expression of p16 and pRb in the following groups of both proximal (cardia) and distal (antral) tissue samples: (a) biopsies showing normal mucosa, (b) biopsies showing intestinal metaplasia and, (c) gastric cancer resection specimens including uninvolved mucosa and tumour. RESULTS: In the antrum there were highly significant trends for increased p16 expression with concomitant (and in the group of carcinomas inversely proportional) decreased pRb expression from normal mucosa to intestinal metaplasia to uninvolved mucosa (from cancer resections) to carcinoma. In the cardia, there were no differences in p16 expression between the various types of tissue samples whereas pRb expression was higher in normal mucosa compared with intestinal metaplasia and tissue from cancer resections. CONCLUSION: Alterations in the pRb pathway appear to play a more significant role in distal gastric carcinogenesis. It may be an early event in the former location since the trend towards p16 overexpression with concomitant pRb underexpression was seen as early as between normal mucosa and intestinal metaplasia. Importantly, the marked differences in expression of pRb and p16 between the cardia and antrum strongly support the hypothesis that tumours of the two locations are genetically different which may account for some of the observed epidemiological differences. PMID:14695761

Effects of Volcanic Eruptions on Stratospheric Ozone Recovery

NASA Technical Reports Server (NTRS)

Rosenfield, Joan E.

2002-01-01

The effects of the stratospheric sulfate aerosol layer associated with the Mt. Pinatubo volcano and future volcanic eruptions on the recovery of the ozone layer is studied with an interactive two-dimensional photochemical model. The time varying chlorine loading and the stratospheric cooling due to increasing carbon dioxide have been taken into account. The computed ozone and temperature changes associated with the Mt. Pinatubo eruption in 1991 agree well with observations. Long model runs out to the year 2050 have been carried out, in which volcanoes having the characteristics of the Mount Pinatubo volcano were erupted in the model at 10-year intervals starting in the year 2010. Compared to a non-volcanic run using background aerosol loading, transient reductions of globally averaged column ozone of 2-3 percent were computed as a result of each of these eruptions, with the ozone recovering to that computed for the non-volcanic case in about 5 years after the eruption. Computed springtime Arctic column ozone losses of from 10 to 18 percent also recovered to the non-volcanic case within 5 years. These results suggest that the long-term recovery of ozone would not be strongly affected by infrequent volcanic eruptions with a sulfur loading approximating Mt. Pinatubo. Sensitivity studies in which the Arctic lower stratosphere was forced to be 4 K and 10 K colder resulted in transient ozone losses of which also recovered to the non-volcanic case in 5 years. A case in which a volcano five times Mt. Pinatubo was erupted in the year 2010 led to maximum springtime column ozone losses of 45 percent which took 10 years to recover to the background case. Finally, in order to simulate a situation in which frequent smaller volcanic eruptions result in increasing the background sulfate loading, a simulation was made in which the background aerosol was increased by 10 percent per year. This resulted in a delay of the recovery of column ozone to 1980 values of more than 10 years.

C/EBPβ LIP and c-Jun synergize to regulate expression of the murine progesterone receptor.

PubMed

Wang, Weizhong; Do, Han Ngoc; Aupperlee, Mark D; Durairaj, Srinivasan; Flynn, Emily E; Miksicek, Richard J; Haslam, Sandra Z; Schwartz, Richard C

2018-06-02

CCAAT/enhancer binding protein β (C/EBPβ) is required for murine mammary ductal morphogenesis and alveologenesis. Progesterone is critical for proliferation and alveologenesis in adult mammary glands, and there is a similar requirement for progesterone receptor isoform B (PRB) in alveologenesis. We examined C/EBPβ regulation of PR expression. All three C/EBPβ isoforms, including typically inhibitory LIP, transactivated the PR promoter. LIP, particularly, strongly synergized with c-Jun to drive PR transcription. Endogenous C/EBPβ and c-Jun stimulated a PR promoter-reporter and these two factors showed promoter occupancy on the endogenous PR gene. Additionally, LIP overexpression elevated endogenous PR protein expression. In pregnancy, both PRB and the relative abundance of LIP among C/EBPβ isoforms increase. Consistent with a role in PRB expression, in vivo C/EBPβ and PR isoform A expression showed mutually exclusive localization in mammary epithelium, while C/EBPβ and PRB largely co-localized. We suggest a critical role for C/EBPβ, particularly LIP, in PRB expression. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

Ozone, Climate, and Global Atmospheric Change.

ERIC Educational Resources Information Center

Levine, Joel S.

1992-01-01

Presents an overview of global atmospheric problems relating to ozone depletion and global warming. Provides background information on the composition of the earth's atmosphere and origin of atmospheric ozone. Describes causes, effects, and evidence of ozone depletion and the greenhouse effect. A vignette provides a summary of a 1991 assessment of…

Atopic asthmatic subjects but not atopic subjects without asthma have enhanced inflammatory response to ozone

EPA Science Inventory

BACKGROUND: Asthma is a known risk factor for acute ozone-associated respiratory disease. Ozone causes an immediate decrease in lung function and increased airway inflammation. The role of atopy and asthma in modulation of ozone-induced inflammation has not been determined. OB...

Mixing Heights and Three-Dimensional Ozone Structure Observed by Airborne Lidar During the 2006 Texas Air Quality Study

NASA Astrophysics Data System (ADS)

Hardesty, R. M.; Senff, C. J.; Alvarez, R. J.; Banta, R. M.; Sandberg, S. P.; Weickmann, A. M.; Darby, L. S.

2007-12-01

A new all solid state ozone lidar was deployed on a NOAA Twin Otter to study boundary layer ozone and aerosol, mostly around Houston, during the 2006 Texas Air Quality Study. The new instrument transmits high pulse-rate, low pulse-energy light at 3 wavelengths in the ultraviolet to obtain ozone profiles with 500 m horizontal resolution and 90 m vertical resolution. During the Texas field study, 20 research flights resulted in nearly 70 hours of ozone measurements during the period from August 1 to September 15. Science objectives included characterization of background ozone levels over rural areas near Houston and Dallas and variability and structure of the boundary layer over different surface types, including urban, wooded, and agricultural land surface areas as well as over Galveston Bay and the Gulf of Mexico. A histogram of all boundary layer ozone concentration measurements showed a bimodal distribution with modes at 45 ppb and 70 ppb. The lower mode correlated with southerly flow, when relatively clean air was transported onshore into the Houston area. Segmenting the observations during southerly flow by region, including the Gulf of Mexico, land within about 55 km from the coast, and further inland indicated that background levels increased by about 10 ppb as air was transported onshore. During the latter part of the experiment, as more pollution was imported into the Houston region, background levels rose to nearly 80 ppb in regions N of Houston. Two flights aimed at observing import of ozone into Texas from the east showed that ozone concentrations increased and boundary layer depths deepened upwind of Houston between September 4 and September 8. Background levels rose by more than 10 ppb over this period. In addition to ozone measurements, we also estimated boundary layer height based on maximum gradient in observed backscatter. The technique worked well when the layer topped by the strongest gradient extends down to the surface. Investigation of the correlation between ozone levels and mixing layer heights both within and external to the Houston urban plume showed a variety of relationships, depending on, e.g., wind direction and occurrence of a bay/gulf breeze. On a day-to-day basis, higher ozone levels were weakly correlated with deeper mixing levels - this was likely due to advection of the urban heat island downwind with the high-ozone urban plume.

Physical-Chemical Treatment of Metals and Radionuclides in the Saturated Zone Using Colloidal Buffers - 12515

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

Lai, Yenjung; Borden, Robert C.; Alperin, Ed

There are numerous acidic plumes throughout the DOE complex and the nation as a whole. Low aquifer pH is a major concern since many important radionuclides (Pu, Ra, Sr, Tc) and metals (Cd, Co, Cs, Mn, Ni, Pb, Zn) strongly sorb to iron hydroxides and aluminosilicates under neutral to alkaline conditions, but are mobile in acidic plumes. To effectively use natural and enhanced attenuation (NEA) for management of these contaminants, we must be able to raise aquifer pH and maintain it at background levels until the external acid loading to the aquifer has dissipated. Geochemical modeling showed that a permeablemore » reactive barrier (PRB) formed by injection of colloidal Mg(OH){sub 2} would last much longer than colloidal Ca(OH){sub 2} due to the much lower solubility of Mg(OH){sub 2}. Assuming a 1,000 meq/L suspension of colloidal Mg(OH)2 could be effectively distributed, the PRB could last over twenty years before rejuvenation was required. Preliminary bench-scale treatability studies were conducted to demonstrate the efficacy of increasing the aquifer pH using a colloidal pH buffer. Laboratory studies demonstrated that three different colloidal Mg(OH){sub 2} suspensions (concentration varied from 1,000 to 1,250 meq/L) could be transported through the columns packed with aquifer sand without significant permeability loss. The time before suspension breakthrough into the column effluent varied with surface treatment, indicating the Mg(OH)2 retention and PRB longevity could be controlled by varying the suspension surface treatment. (authors)« less

2015 Revision to 2008 Ozone National Ambient Air Quality Standards (NAAQS) Related Documents

EPA Pesticide Factsheets

Find tools for background ozone, maps of nonattainment areas, an overview of the proposal, and information on designations, monitoring and permitting requirements and a presentation on the 2015 ozone NAAQS revision.

The Nevada Rural Ozone Initiative: Field measurements of surface ozone in rural settings

NASA Astrophysics Data System (ADS)

Fine, R.; Gustin, M. S.; Weiss-Penzias, P. S.; Jaffe, D. A.; Peterson, C.

2011-12-01

The Nevada Rural Ozone Initiative (NVROI) focuses on measuring ozone and other parameters at rural sites across Nevada. The project was prompted by observations of elevated ozone concentrations at Great Basin National Park (GBNP), a remote location at the eastern boundary of the state. Past CASTNET data collected at GBNP demonstrated that the area will be out of attainment if the new ozone NAAQS are established at any values between 60 and 70 ppb. To examine the ozone sources we have augmented the CASTNET data at GBNP with measurements at additional sites. NVROI field sites are situated between 1390 and 2080 meters above sea level along transects consistent with the prevailing wind directions across the state. Data collection began in July 2011. Measurements indicate significant variability in the diel pattern of ozone concentrations between field sites suggesting that site specific physicochemical characteristics, free tropospheric inputs, and regional transport of air pollutants all influence observed values at these background sites. Ancillary gas, particulate matter, and meteorological parameters will be coupled with trajectory analyses to investigate the influence of local, regional, and long range sources on background ozone concentrations.

Surface ozone at Nam Co in the inland Tibetan Plateau: variation, synthesis comparison and regional representativeness

NASA Astrophysics Data System (ADS)

Yin, Xiufeng; Kang, Shichang; de Foy, Benjamin; Cong, Zhiyuan; Luo, Jiali; Zhang, Lang; Ma, Yaoming; Zhang, Guoshuai; Rupakheti, Dipesh; Zhang, Qianggong

2017-09-01

Ozone is an important pollutant and greenhouse gas, and tropospheric ozone variations are generally associated with both natural and anthropogenic processes. As one of the most pristine and inaccessible regions in the world, the Tibetan Plateau has been considered as an ideal region for studying processes of the background atmosphere. Due to the vast area of the Tibetan Plateau, sites in the southern, northern and central regions exhibit different patterns of variation in surface ozone. Here, we present continuous measurements of surface ozone mixing ratios at Nam Co Station over a period of ˜ 5 years (January 2011 to October 2015), which is a background site in the inland Tibetan Plateau. An average surface ozone mixing ratio of 47.6 ± 11.6 ppb (mean ± standard deviation) was recorded, and a large annual cycle was observed with maximum ozone mixing ratios in the spring and minimum ratios during the winter. The diurnal cycle is characterized by a minimum in the early morning and a maximum in the late afternoon. Nam Co Station represents a background region where surface ozone receives negligible local anthropogenic emissions inputs, and the anthropogenic contribution from South Asia in spring and China in summer may affect Nam Co Station occasionally. Surface ozone at Nam Co Station is mainly dominated by natural processes involving photochemical reactions, vertical mixing and downward transport of stratospheric air mass. Model results indicate that the study site is affected differently by the surrounding areas in different seasons: air masses from the southern Tibetan Plateau contribute to the high ozone levels in the spring, and enhanced ozone levels in the summer are associated with air masses from the northern Tibetan Plateau. By comparing measurements at Nam Co Station with those from other sites on the Tibetan Plateau, we aim to expand the understanding of ozone cycles and transport processes over the Tibetan Plateau. This work may provide a reference for future model simulations.

2014 Proposed Revision to 2008 Ozone National Ambient Air Quality Standards (NAAQS) Supporting Documents

EPA Pesticide Factsheets

Find information on the 2014 proposed ozone NAAQS revision, and find tools for background ozone, maps of nonattainment areas, an overview of the proposal, and information on designations, monitoring and permitting requirements

A parapoxviral virion protein targets the retinoblastoma protein to inhibit NF-κB signaling

PubMed Central

Nagendraprabhu, Ponnuraj; Khatiwada, Sushil; Chaulagain, Sabal

2017-01-01

Poxviruses have evolved multiple strategies to subvert signaling by Nuclear Factor κB (NF-κB), a crucial regulator of host innate immune responses. Here, we describe an orf virus (ORFV) virion-associated protein, ORFV119, which inhibits NF-κB signaling very early in infection (≤ 30 min post infection). ORFV119 NF-κB inhibitory activity was found unimpaired upon translation inhibition, suggesting that virion ORFV119 alone is responsible for early interference in signaling. A C-terminal LxCxE motif in ORFV119 enabled the protein to interact with the retinoblastoma protein (pRb) a multifunctional protein best known for its tumor suppressor activity. Notably, experiments using a recombinant virus containing an ORFV119 mutation which abrogates its interaction with pRb together with experiments performed in cells lacking or with reduced pRb levels indicate that ORFV119 mediated inhibition of NF-κB signaling is largely pRb dependent. ORFV119 was shown to inhibit IKK complex activation early in infection. Consistent with IKK inhibition, ORFV119 also interacted with TNF receptor associated factor 2 (TRAF2), an adaptor protein recruited to signaling complexes upstream of IKK in infected cells. ORFV119-TRAF2 interaction was enhanced in the presence of pRb, suggesting that ORFV119-pRb complex is required for efficient interaction with TRAF2. Additionally, transient expression of ORFV119 in uninfected cells was sufficient to inhibit TNFα-induced IKK activation and NF-κB signaling, indicating that no other viral proteins are required for the effect. Infection of sheep with ORFV lacking the ORFV119 gene led to attenuated disease phenotype, indicating that ORFV119 contributes to virulence in the natural host. ORFV119 represents the first poxviral protein to interfere with NF-κB signaling through interaction with pRb. PMID:29244863

Seasonal and diurnal variations of ozone at a high-altitude mountain baseline station in East Asia

NASA Astrophysics Data System (ADS)

Ou Yang, Chang-Feng; Lin, Neng-Huei; Sheu, Guey-Rong; Lee, Chung-Te; Wang, Jia-Lin

2012-01-01

Continuous measurements of tropospheric ozone were conducted at the Lulin Atmospheric Background Station (LABS) at an altitude of 2862 m from April 2006 to the end of 2009. Distinct seasonal variations in the ozone concentration were observed at the LABS, with a springtime maximum and a summertime minimum. Based on a backward trajectory analysis, CO data, and ozonesondes, the springtime maximum was most likely caused by the long-range transport of air masses from Southeast Asia, where biomass burning was intense in spring. In contrast, a greater Pacific influence contributed to the summertime minimum. In addition to seasonal variations, a distinct diurnal pattern was also observed at the LABS, with a daytime minimum and a nighttime maximum. The daytime ozone minimum was presumably caused by sinks of dry deposition and NO titration during the up-slope transport of surface air. The higher nighttime values, however, could be the result of air subsidence at night bringing ozone aloft to the LABS. After filtering out the daytime data to remove possible local surface contributions, the average background ozone value for the period of 2006-2009 was approximately 36.6 ppb, increased from 32.3 ppb prior to data filtering, without any changes in the seasonal pattern. By applying HYSPLIT4 model analysis, the origins of the air masses contributing to the background ozone observed at the LABS were investigated.

Perceived Risk of Burglary and Fear of Crime: Individual- and Country-Level Mixed Modeling.

PubMed

Chon, Don Soo; Wilson, Mary

2016-02-01

Given the scarcity of prior studies, the current research introduced country-level variables, along with individual-level ones, to test how they are related to an individual's perceived risk of burglary (PRB) and fear of crime (FC), separately, by using mixed-level logistic regression analyses. The analyses of 104,218 individuals, residing in 50 countries, showed that country-level poverty was positively associated with FC only. However, individual-level variables, such as prior property crime victimization and female gender, had consistently positive relationships with both PRB and FC. However, age group and socioeconomic status were inconsistent between those two models, suggesting that PRB and FC are two different concepts. Finally, no significant difference in the pattern of PRB and FC was found between a highly developed group of countries and a less developed one. © The Author(s) 2014.

Extraction of wind and temperature information from hybrid 4D-Var assimilation of stratospheric ozone using NAVGEM

NASA Astrophysics Data System (ADS)

Allen, Douglas R.; Hoppel, Karl W.; Kuhl, David D.

2018-03-01

Extraction of wind and temperature information from stratospheric ozone assimilation is examined within the context of the Navy Global Environmental Model (NAVGEM) hybrid 4-D variational assimilation (4D-Var) data assimilation (DA) system. Ozone can improve the wind and temperature through two different DA mechanisms: (1) through the flow-of-the-day ensemble background error covariance that is blended together with the static background error covariance and (2) via the ozone continuity equation in the tangent linear model and adjoint used for minimizing the cost function. All experiments assimilate actual conventional data in order to maintain a similar realistic troposphere. In the stratosphere, the experiments assimilate simulated ozone and/or radiance observations in various combinations. The simulated observations are constructed for a case study based on a 16-day cycling truth experiment (TE), which is an analysis with no stratospheric observations. The impact of ozone on the analysis is evaluated by comparing the experiments to the TE for the last 6 days, allowing for a 10-day spin-up. Ozone assimilation benefits the wind and temperature when data are of sufficient quality and frequency. For example, assimilation of perfect (no applied error) global hourly ozone data constrains the stratospheric wind and temperature to within ˜ 2 m s-1 and ˜ 1 K. This demonstrates that there is dynamical information in the ozone distribution that can potentially be used to improve the stratosphere. This is particularly important for the tropics, where radiance observations have difficulty constraining wind due to breakdown of geostrophic balance. Global ozone assimilation provides the largest benefit when the hybrid blending coefficient is an intermediate value (0.5 was used in this study), rather than 0.0 (no ensemble background error covariance) or 1.0 (no static background error covariance), which is consistent with other hybrid DA studies. When perfect global ozone is assimilated in addition to radiance observations, wind and temperature error decreases of up to ˜ 3 m s-1 and ˜ 1 K occur in the tropical upper stratosphere. Assimilation of noisy global ozone (2 % errors applied) results in error reductions of ˜ 1 m s-1 and ˜ 0.5 K in the tropics and slightly increased temperature errors in the Northern Hemisphere polar region. Reduction of the ozone sampling frequency also reduces the benefit of ozone throughout the stratosphere, with noisy polar-orbiting data having only minor impacts on wind and temperature when assimilated with radiances. An examination of ensemble cross-correlations between ozone and other variables shows that a single ozone observation behaves like a potential vorticity (PV) charge, or a monopole of PV, with rotation about a vertical axis and vertically oriented temperature dipole. Further understanding of this relationship may help in designing observation systems that would optimize the impact of ozone on the dynamics.

Evaluating long-term patterns of decreasing groundwater discharge through a lake-bottom permeable reactive barrier.

PubMed

McCobb, Timothy D; Briggs, Martin A; LeBlanc, Denis R; Day-Lewis, Frederick D; Johnson, Carole D

2018-05-18

Identifying and quantifying groundwater exchange is critical when considering contaminant fate and transport at the groundwater/surface-water interface. In this paper, areally distributed temperature and point seepage measurements are used to efficiently assess spatial and temporal groundwater discharge patterns through a glacial-kettle lakebed area containing a zero-valent iron permeable reactive barrier (PRB). Concern was that the PRB was becoming less permeable with time owing to biogeochemical processes within the PRB. Patterns of groundwater discharge over an 8-year period were examined using fiber-optic distributed temperature sensing (FO-DTS) and snapshot-in-time point measurements of temperature. The resulting thermal maps show complex and uneven distributions of temperatures across the lakebed and highlight zones of rapid seepage near the shoreline and along the outer boundaries of the PRB. Repeated thermal mapping indicates an increase in lakebed temperatures over time at periods of similar stage and surface-water temperature. Flux rates in six seepage meters permanently installed on the lakebed in the PRB area decreased on average by 0.021 md -1 (or about 4.5 percent) annually between 2004 and 2015. Modeling of diurnal temperature signals from shallow vertical profiles yielded mean flux values ranging from 0.39 to 1.15 md -1 , with stronger fluxes generally related to colder lakebed temperatures. The combination of an increase in lakebed temperatures, declines in direct seepage, and observations of increased cementation of the lakebed surface provide in situ evidence that the permeability of the PRB is declining. The presence of temporally persistent rapid seepage zones is also discussed. Published by Elsevier Ltd.

Modeling the Effect of Temperature on Ozone-Related Mortality.

EPA Science Inventory

Modeling the Effect of Temperature on Ozone-Related Mortality. Wilson, Ander, Reich, Brian J, Neas, Lucas M., Rappold, Ana G. Background: Previous studies show ozone and temperature are associated with increased mortality; however, the joint effect is not well explored. Underst...

Ozone and its projection in regard to climate change

NASA Astrophysics Data System (ADS)

Melkonyan, Ani; Wagner, Patrick

2013-03-01

In this paper, the dependence of ozone-forming potential on temperature was analysed based on data from two stations (with an industrial and rural background, respectively) in North Rhine-Westphalia, Germany, for the period of 1983-2007. After examining the interrelations between ozone, NOx and temperature, a projection of the days with ozone exceedance (over a limit value of a daily maximum 8-h average ≥ 120 μg m-3 for 25 days per year averaged for 3 years) in terms of global climate change was made using probability theory and an autoregression integrated moving average (ARIMA) model. The results show that with a temperature increase of 3 K, the frequency of days when ozone exceeds its limit value will increase by 135% at the industrial station and by 87% at the rural background station.

A survey of valleys and basins of the western United States for the capacity to produce winter ozone.

PubMed

Mansfield, Marc L; Hall, Courtney F

2018-04-18

High winter ozone in the Uintah Basin, Utah, and the Upper Green River Basin, Wyoming, occurs because of the confluence of three separate factors: (1) extensive oil or natural gas production, (2) topography conducive to strong multiple-day thermal inversions, and (3) snow cover. We surveyed 13 basins and valleys in the western United States for the existence and magnitude of these factors. Seven of the basins, because winter ozone measurements were available, were assigned to four different behavioral classes. Based on similarities among the basins, the remaining six were also given a tentative assignment. Two classes (1 and 2) correspond to basins with high ozone because all three factors just listed are present at sufficient magnitude. Class 3 corresponds to rural basins with ozone at background levels, and occurs because at least one of the three factors is weak or absent. Class 4 corresponds to ozone below background levels, and occurs, for example, in urban basins where emissions scavenge ozone. All three factors are present in the Wind River Basin, Wyoming, but compared to the Uintah or the Upper Green Basins, it has only moderate oil and gas production and is assigned to class 3. We predict that the Wind River Basin, as well as other class 3 basins that have inversions and snow cover, would transition from background (class 3) to high ozone behavior (class 1 or 2) if oil or gas production were to intensify, or to class 4 (low winter ozone) if they were to become urban. High ozone concentrations in winter only occur in basins or valleys that have an active oil and natural gas production industry, multiple-day thermal inversions, and snow cover, and have only been documented in two basins worldwide. We have examined a number of other candidate basins in the western United States and conclude that these factors are either absent or too weak to produce high winter ozone. This study illustrates how strong each factor needs to be before winter ozone can be expected, and can be used by planners and regulators to foresee the development of winter ozone problems.

75 FR 70289 - Notice of Appointment of Individuals to Serve as Members of Performance Review Board

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-17

... INFORMATION CONTACT: Cynthia Roscoe, Director of Human Resources, U.S. International Trade Commission (202... the PRB: Vice Chairman Irving A. Williamson Vice-Chair of the PRB: Commissioner Daniel R. Pearson...

75 FR 38549 - Notice of Appointment of Individuals To Serve as Members of Performance Review Board

Federal Register 2010, 2011, 2012, 2013, 2014

2010-07-02

... INFORMATION CONTACT: Cynthia Roscoe, Director of Human Resources, U.S. International Trade Commission (202... the PRB: Commissioner Daniel R. Pearson. Vice-Chair of the PRB: Commissioner Dean A. Pinkert. Member...

Ozone Exposure-Response in Field Grown Soybean: Characterizing Intraspecific Variability of Physiology and Biochemistry

USDA-ARS?s Scientific Manuscript database

Crop losses due to rising tropospheric ozone concentrations ([ozone]) in 2000 were estimated to cost $1.8 to $3.9 billion in the U.S. and $3.0 to $5.5 billion in China, and are expected to grow with the predicted 25% increase in background [ozone] over the next 30 to 50 years. This challenge provide...

Estimating North American background ozone in U.S. surface air with two independent global models: Variability, uncertainties, and recommendations

EPA Science Inventory

Accurate estimates for North American background (NAB) ozone (O3) in surface air over the United States are needed for setting and implementing an attainable national O3 standard. These estimates rely on simulations with atmospheric chemistry-transport models that set North Amer...

Surface ozone at the Swiss Alpine site Arosa: the hemispheric background and the influence of large-scale anthropogenic emissions

NASA Astrophysics Data System (ADS)

Pochanart, Pakpong; Akimoto, Hajime; Maksyutov, Shamil; Staehelin, Johannes

An innovative and effective method using isentropic trajectory analysis based on the residence time of air masses over the polluted region of Europe was successfully applied to categorize surface ozone amounts at Arosa, Switzerland during 1996-1997. The "European representative" background ozone seasonal cycle at Arosa is associated with long-range transport of North Atlantic air masses, and displays the spring maximum-summer minimum with an annual average of 35 ppb. The photochemical ozone production due to the intense large-scale anthropogenic emission over Europe is estimated as high as 20 ppb in summer, whereas it is insignificant in winter. European sources contribute an annual net ozone production of 9-12 ppb at Arosa. Comparison with the selected regional representative site in Western Europe shows similar results indicating that the categorized ozone data at Arosa by this technique could be regarded as a representative for northern hemispheric mid-latitudes.

PERMEABLE REACTIVE BARRIERS FOR REMEDIATION OF INORGANIC CONTAMINANTS

EPA Science Inventory

The permeable reactive barrier (PRB) technology is an in-situ approach for groundwater remediation that couples subsurface flow management with a passive chemical or biochemical treatment zone. The development and application of the PRB technology has progressed over the last de...

COMBINATION OF IRON AND MIXED ANAEROBIC CULTURE FOR PERCHLOROETHENE DEGRADATION

EPA Science Inventory

Permeable reactive barriers (PRB's) are an emerging, alternative in-situ approach for remediating contaminated groundwater that combine subsurface fluid flow management with a passive chemical treatment zone. PRB's are a potentially more cost effective treatment option at severa...

COST ANALYSIS OF PERMEABLE REACTIVE BARRIERS FOR REMEDIATION OF GROUND WATER

EPA Science Inventory

ABSTRACT

Permeable reactive barriers (PRB's) are an emerging, alternative in-situ approach for remediating contaminated groundwater that combine subsurface fluid flow management with a passive chemical treatment zone. PRB's are a potentially more cost effective treatment...

Permeable Reactive Barriers for Treatment of Cr6

EPA Science Inventory

Several options are available for treatment of hexavalent chromium (Cr(VI)) in groundwater using the permeable reactive barrier (PRB) approach. They include conventional trench-and-fill systems, chemical redox curtains, and organic carbon redox curtains. Each of these PRB syste...

Oil production and subsidence trends from InSAR over the Powder River Basin, WY

NASA Astrophysics Data System (ADS)

Devlin, K. R.; Borsa, A. A.; Neely, W.

2017-12-01

Interferometric synthetic aperture radar (InSAR) has proven to be a viable tool to study subsidence from numerous causes, including anthropogenic sources such as mining and drilling. The Powder River Basin (PRB) of northeastern Wyoming has been a historical region of hydrocarbon extraction, producing much of the coal, oil, natural gas, and coalbed methane used in the United States. Although coal production in the PRB is stagnant, oil and gas production has increased over the last decade. Using data from ESA's Sentinel-1 mission, we create a suite of interferograms to study the surface deformation history of the PRB . We examined two and a half years of data from 11-07-2014 to 06-24-2017 along a single track (129) covering the coalbed and a region of high oil well concentration and production . We assess the ability of InSAR to detect subsidence over increasing temporal baselines, and use the resulting error estimates to guide our interferogram processing. We then produce a surface deformation time series for the PRB from the interferograms and use these data to model volumetric changes of the subsurface. Our results provide constraints on natural resource extraction in the PRB and information about the suitability of using InSAR to monitor human activity.

75 FR 54445 - Senior Executive Service; Financial Management Service Performance Review Board (PRB)

Federal Register 2010, 2011, 2012, 2013, 2014

2010-09-07

..., Management (Chief Financial Officer). Alfred J. Kopec, Assistant Commissioner, Business Architecture. Sheryl... DEPARTMENT OF THE TREASURY Fiscal Service Senior Executive Service; Financial Management Service Performance Review Board (PRB) AGENCY: Financial Management Service, Fiscal Service, Treasury. ACTION: Notice...

LONG TERM PERFORMANCE MONITORING OF A PRB FOR REMEDIATION OF CHLORINATED SOLVENTS AND CHROMIUM

EPA Science Inventory

Permeable reactive barriers (PRB's) are an emerging, alternative in-situ approach for remediating groundwater contamination that combine subsurface fluid flow management with a passive chemical treatment zone. The few pilot and commercial installations which have been implemented...

BIOMASS ACCUMULATION AT THE ELIZABETH CITY AND DENVER FEDERAL CENTER PRBS

EPA Science Inventory

Microbial characterization results, based on PLFA profiles, from the Elizabeth City PRB and adjacent aquifer materials showed a diverse microbiological community dominated by Gram-negative bacteria. Iron core samples from near the upgradient edge of the PRB are typically enriche...

75 FR 69642 - Membership of the Performance Review Board (PRB)

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-15

... DEPARTMENT OF DEFENSE Office of the Secretary Membership of the Performance Review Board (PRB... Executive Service performance appraisals and makes recommendations regarding performance ratings and performance scores to the Director, Defense Threat Reduction Agency. DATES: Effective Date: The effective date...

76 FR 65503 - Performance Review Board Membership

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-21

... executive and by any higher-level executive or executives. The PRB makes recommendations to the appointing authority relative to the performance of the senior executive, including recommendations on performance awards. The Department of Education's PRB also makes recommendations on SES pay adjustments for career...

Impact of FeS Mineralogy on TCE Degradation

EPA Science Inventory

Iron- and sulfate-reducing conditions are often encountered in permeable reactive barrier (PRB) systems that are constructed to remove TCE from groundwater, which usually leads to the accumulation of FeS mineral phases in the matrix of the PRB. Poorly crystalline mackinawite (Fe...

Quantifying wintertime boundary layer ozone production from frequent profile measurements in the Uinta Basin, UT, oil and gas region

NASA Astrophysics Data System (ADS)

Schnell, Russell C.; Johnson, Bryan J.; Oltmans, Samuel J.; Cullis, Patrick; Sterling, Chance; Hall, Emrys; Jordan, Allen; Helmig, Detlev; Petron, Gabrielle; Ahmadov, Ravan; Wendell, James; Albee, Robert; Boylan, Patrick; Thompson, Chelsea R.; Evans, Jason; Hueber, Jacques; Curtis, Abigale J.; Park, Jeong-Hoo

2016-09-01

As part of the Uinta Basin Winter Ozone Study, January-February 2013, we conducted 937 tethered balloon-borne ozone vertical and temperature profiles from three sites in the Uinta Basin, Utah (UB). Emissions from oil and gas operations combined with snow cover were favorable for producing high ozone-mixing ratios in the surface layer during stagnant and cold-pool episodes. The highly resolved profiles documented the development of approximately week-long ozone production episodes building from regional backgrounds of 40 ppbv to >165 ppbv within a shallow cold pool up to 200 m in depth. Beginning in midmorning, ozone-mixing ratios increased uniformly through the cold pool layer at rates of 5-12 ppbv/h. During ozone events, there was a strong diurnal cycle with each succeeding day accumulating 4-8 ppbv greater than the previous day. The top of the elevated ozone production layer was nearly uniform in altitude across the UB independent of topography. Above the ozone production layer, mixing ratios decreased with height to 400 m above ground level where they approached regional background levels. Rapid clean-out of ozone-rich air occurred within a day when frontal systems brought in fresh air. Solar heating and basin topography led to a diurnal flow pattern in which daytime upslope winds distributed ozone precursors and ozone in the Basin. NOx-rich plumes from a coal-fired power plant in the eastern sector of the Basin did not appear to mix down into the cold pool during this field study.

The Retinoblastoma Tumor Suppressor Regulates a Xenobiotic Detoxification Pathway

PubMed Central

Sáenz Robles, Maria Teresa; Case, Ashley; Chong, Jean-Leon; Leone, Gustavo; Pipas, James M.

2011-01-01

The retinoblastoma tumor suppressor (pRb) regulates cell cycle entry, progression and exit by controlling the activity of the E2F-family of transcription factors. During cell cycle exit pRb acts as a transcriptional repressor by associating with E2F proteins and thereby inhibiting their ability to stimulate the expression of genes required for S phase. Indeed, many tumors harbor mutations in the RB gene and the pRb-E2F pathway is compromised in nearly all types of cancers. In this report we show that both pRb and its interacting partners, the transcriptional factors E2F1-2-3, act as positive modulators of detoxification pathways important for metabolizing and clearing xenobiotics—such as toxins and drugs—from the body. Using a combination of conventional molecular biology techniques and microarray analysis of specific cell populations, we have analyzed the detoxification pathway in murine samples in the presence or absence of pRb and/or E2F1-2-3. In this report, we show that both pRb and E2F1-2-3 act as positive modulators of detoxification pathways in mice, challenging the conventional view of E2F1-2-3 as transcriptional repressors negatively regulated by pRb. These results suggest that mutations altering the pRb-E2F axis may have consequences beyond loss of cell cycle control by altering the ability of tissues to remove toxins and to properly metabolize anticancer drugs, and might help to understand the formation and progression rates of different types of cancer, as well as to better design appropriate therapies based on the particular genetic composition of the tumors. PMID:22022495

Inactivation of retinoblastoma protein does not overcome the requirement for human cytomegalovirus UL97 in lamina disruption and nuclear egress.

PubMed

Reim, Natalia I; Kamil, Jeremy P; Wang, Depeng; Lin, Alison; Sharma, Mayuri; Ericsson, Maria; Pesola, Jean M; Golan, David E; Coen, Donald M

2013-05-01

Human cytomegalovirus (HCMV) encodes one conventional protein kinase, UL97. During infection, UL97 phosphorylates the retinoblastoma tumor suppressor protein (pRb) on sites ordinarily phosphorylated by cyclin-dependent kinases (CDK), inactivating the ability of pRb to repress host genes required for cell cycle progression to S phase. UL97 is important for viral DNA synthesis in quiescent cells, but this function can be replaced by human papillomavirus type 16 E7, which targets pRb for degradation. However, viruses in which E7 replaces UL97 are still defective for virus production. UL97 is also required for efficient nuclear egress of viral nucleocapsids, which is associated with disruption of the nuclear lamina during infection, and phosphorylation of lamin A/C on serine 22, which antagonizes lamin polymerization. We investigated whether inactivation of pRb might overcome the requirement of UL97 for these roles, as pRb inactivation induces CDK1, and CDK1 phosphorylates lamin A/C on serine 22. We found that lamin A/C serine 22 phosphorylation during HCMV infection correlated with expression of UL97 and was considerably delayed in UL97-null mutants, even when E7 was expressed. E7 failed to restore gaps in the nuclear lamina seen in wild-type but not UL97-null virus infections. In electron microscopy analyses, a UL97-null virus expressing E7 was as impaired as a UL97-null mutant in cytoplasmic accumulation of viral nucleocapsids. Our results demonstrate that pRb inactivation is insufficient to restore efficient viral nuclear egress of HCMV in the absence of UL97 and instead argue further for a direct role of UL97 in this stage of the infectious cycle.

Is the Pearl River basin, China, drying or wetting? Seasonal variations, causes and implications

NASA Astrophysics Data System (ADS)

Zhang, Qiang; Li, Jianfeng; Gu, Xihui; Shi, Peijun

2018-07-01

Soil moisture plays crucial roles in the hydrological cycle and is also a critical link between land surface and atmosphere. The Pearl River basin (PRb) is climatically subtropical and tropical and is highly sensitive to climate changes. In this study, seasonal soil moisture changes across the PRb were analyzed using the Variable Infiltration Capacity (VIC) model forced by the gridded 0.5° × 0.5° climatic observations. Seasonal changes of soil moisture in both space and time were investigated using the Mann-Kendall trend test method. Potential influencing factors behind seasonal soil moisture changes such as precipitation and temperature were identified using the Maximum Covariance Analysis (MCA) technique. The results indicated that: (1) VIC model performs well in describing changing properties of soil moisture across the PRb; (2) Distinctly different seasonal features of soil moisture can be observed. Soil moisture in spring decreased from east to west parts of the PRb. In summer however, soil moisture was higher in east and west parts but was lower in central parts of the PRb; (3) A significant drying trend was identified over the PRb in autumn, while no significant drying trends can be detected in other seasons; (4) The increase/decrease in precipitation can generally explain the wetting/drying tendency of soil moisture. However, warming temperature contributed significantly to the drying trends and these drying trends were particularly evident during autumn and winter; (5) Significant decreasing precipitation and increasing temperature combined to trigger substantially decreasing soil moisture in autumn. In winter, warming temperature is the major reason behind decreased soil moisture although precipitation is in slightly decreasing tendency. Season variations of soil moisture and related implications for hydro-meteorological processes in the subtropical and tropical river basins over the globe should arouse considerable human concerns.

Aptopic asthmatic subjects but not aptopic subjects without asthma have enhanced inflammatory response to ozone**

EPA Science Inventory

Background Asthma is a known risk factor for acute ozone-associated respiratory disease. Ozone (03) causes an immediate decrease in lung function and increased airway inflammation. The role of atopy and asthma in modulation of 03-induced inflammation has not been determined. Ob...

The glutathione-S-transferase Mu 1 null genotype modulates ozone-induced airway inflammation in humans*

EPA Science Inventory

Background: The Glutathione-S-Transferase Mu 1 null genotype has been reported to be a risk factor for acute respiratory disease associated with increases in ambient air ozone. Ozone is known to cause an immediate decrease in lung function and increased airway inflammation. Howev...

Ozone exposure is associated with acute changes in inflammation, fibrinolysis, and endothelial cell function in coronary artery disease patients

EPA Science Inventory

Background: Air pollution is a major risk factor for cardiovascular disease, of which ozone is a major contributor. Several studies have found associations between ozone and cardiovascular morbidity, but the results have been inconclusive. We investigated associations between oz...

LONG-TERM PERFORMANCE MONITORING OF PERMEABLE REACTIVE BARRIERS TO REMEDIATE CONTAMINATED GROUND WATER

EPA Science Inventory

Permeable reactive barriers (PRB's) are an alternative in-situ approach for remediating contaminated groundwater that combine subsurface fluid flow management with a passive chemical treatment zone. PRB's are being selected with increased frequency at waste sites (more than 40 f...

75 FR 14214 - Senior Executive Service Performance Review Board Membership

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-24

... OCCUPATIONAL SAFETY AND HEALTH REVIEW COMMISSION Senior Executive Service Performance Review Board Membership AGENCY: Occupational Safety and Health Review Commission. ACTION: Annual notice. SUMMARY: Notice... established a Senior Executive Service PRB. The PRB reviews and evaluates the initial appraisal of a senior...

78 FR 5516 - Senior Executive Service Performance Review Board Membership

Federal Register 2010, 2011, 2012, 2013, 2014

2013-01-25

... OCCUPATIONAL SAFETY AND HEALTH REVIEW COMMISSION Senior Executive Service Performance Review Board Membership AGENCY: Occupational Safety and Health Review Commission. ACTION: Annual notice. SUMMARY: Notice... established a Senior Executive Service PRB. The PRB reviews and evaluates the initial appraisal of a senior...

76 FR 39926 - Senior Executive Service Performance Review Board Membership

Federal Register 2010, 2011, 2012, 2013, 2014

2011-07-07

... OCCUPATIONAL SAFETY AND HEALTH REVIEW COMMISSION Senior Executive Service Performance Review Board Membership AGENCY: Occupational Safety and Health Review Commission. ACTION: Annual notice. SUMMARY: Notice... established a Senior Executive Service PRB. The PRB reviews and evaluates the initial appraisal of a senior...

76 FR 81998 - Senior Executive Service Performance Review Board Membership

Federal Register 2010, 2011, 2012, 2013, 2014

2011-12-29

... OCCUPATIONAL SAFETY AND HEALTH REVIEW COMMISSION Senior Executive Service Performance Review Board Membership AGENCY: Occupational Safety and Health Review Commission. ACTION: Annual notice. SUMMARY: Notice... established a Senior Executive Service PRB. The PRB reviews and evaluates the initial appraisal of a senior...

ZERO-VALENT IRON PRB APPLICATION EXPANDS TO ARSENIC REMOVAL

EPA Science Inventory

The U.S. EPA Office of Research and Development’s National Risk Management Research Laboratory (NRMRL) and Region 8 have begun evaluating performance of a pilot-scale permeable reactive barrier (PRB) to treat arsenic-contaminated ground water at the ASARCO Superfund near Helena, ...

PLANT MULCH TO TREAT TCE IN GROUND WATER IN A PRB

EPA Science Inventory

In the past ten years, passive reactive barriers (PRBs) have found widespread application to treat chlorinated solvent contamination in ground water. The traditional PRB commonly uses granular zero-valent iron and/or iron alloys as filling materials for treatment of chlorinated ...

The Impact of FeS Mineralogy on TCE Degradation

EPA Science Inventory

Iron- and sulfate-reducing conditions are often encountered in permeable reactive barrier (PRB) systems that are constructed to remove TCE from groundwater, which usually leads to the accumulation of FeS mineral phases in the matrix of the PRB. Poorly crystalline mackinawite (Fe...

Impact of local and non-local sources of pollution on background US Ozone: synergy of a low-earth orbiting and geostationary sounder constellation

NASA Astrophysics Data System (ADS)

Bowman, K. W.; Lee, M.

2015-12-01

Dramatic changes in the global distribution of emissions over the last decade have fundamentally altered source-receptor pollution impacts. A new generation of low-earth orbiting (LEO) sounders complimented by geostationary sounders over North America, Europe, and Asia providing a unique opportunity to quantify the current and future trajectory of emissions and their impact on global pollution. We examine the potential of this constellation of air quality sounders to quantify the role of local and non-local sources of pollution on background ozone in the US. Based upon an adjoint sensitivity method, we quantify the role synoptic scale transport of non-US pollution on US background ozone over months representative of different source-receptor relationships. This analysis allows us distinguish emission trajectories from megacities, e.g. Beijing, or regions, e.g., western China, from natural trends on downwind ozone. We subsequently explore how a combination of LEO and GEO observations could help quantify the balance of local emissions against changes in distant sources . These results show how this unprecedented new international ozone observing system can monitor the changing structure of emissions and their impact on global pollution.

Expression of retinoblastoma gene product (pRb) in mantle cell lymphomas. Correlation with cyclin D1 (PRAD1/CCND1) mRNA levels and proliferative activity.

PubMed Central

Jares, P.; Campo, E.; Pinyol, M.; Bosch, F.; Miquel, R.; Fernandez, P. L.; Sanchez-Beato, M.; Soler, F.; Perez-Losada, A.; Nayach, I.; Mallofré, C.; Piris, M. A.; Montserrat, E.; Cardesa, A.

1996-01-01

Mantle cell lymphomas (MCLs) are molecularly characterized by bcl-1 rearrangement and constant cyclin D1 (PRAD-1/CCND1) gene overexpression. Cyclin D1 is a G1 cyclin that participates in the control of the cell cycle progression by interacting with the retinoblastoma gene product (pRb). Inactivation of the Rb tumor suppressor gene has been implicated in the development of different types of human tumors including some high grade non-Hodgkin's lymphomas. To determine the role of the retinoblastoma gene in the pathogenesis of MCLs and its possible interaction with cyclin D1, pRb expression was examined in 23 MCLs including 17 typical and 6 blastic variants by immunohistochemistry and Western blot. Rb gene structure was studied in 13 cases by Southern blot. Cytogenetic analysis was performed in 5 cases. The results were compared with the cyclin D1 mRNA levels examined by Northern analysis, and the proliferative activity of the tumors was measured by Ki-67 growth fraction and flow cytometry. pRb was expressed in all MCLs. The expression varied from case to case (mean, 14.1% of positive cells; range, 1.3 to 42%) with a significant correlation with the proliferative activity of the tumors (mitotic index r = 0.85; Ki-67 r = 0.7; S phase = 0.73). Blastic variants showed higher numbers of pRb-positive cells (mean, 29%) than the typical cases (10%; P < 0.005) by immunohistochemistry and, concordantly, higher levels of expression by Western blot. In addition, the blastic cases also had an increased expression of the phosphorylated protein. No alterations in Rb gene structure were observed by Southern blot analysis. Cyclin D1 mRNA levels were independent of pRb expression and the proliferative activity of the tumors. These findings suggest that pRb in MCLs is normally regulated in relation to the proliferative activity of the tumors. Cyclin D1 overexpression may play a role in the maintenance of cell proliferation by overcoming the suppressive growth control of pRb. Images Figure 1 Figure 2 Figure 4 PMID:8623927

A dynamical systems model of progesterone receptor interactions with inflammation in human parturition.

PubMed

Brubaker, Douglas; Barbaro, Alethea; R Chance, Mark; Mesiano, Sam

2016-08-19

Progesterone promotes uterine relaxation and is essential for the maintenance of pregnancy. Withdrawal of progesterone activity and increased inflammation within the uterine tissues are key triggers for parturition. Progesterone actions in myometrial cells are mediated by two progesterone receptor (PR) isoforms, PR-A and PR-B, that function as ligand-activated transcription factors. PR-B mediates relaxatory actions of progesterone, in part, by decreasing myometrial cell responsiveness to pro-inflammatory stimuli. These same pro-inflammatory stimuli promote the expression of PR-A which inhibits the anti-inflammatory activity of PR-B. Competitive interaction between the progesterone receptors then augments myometrial responsiveness to pro-inflammatory stimuli. The interaction between PR-B transcriptional activity and inflammation in the pregnancy myometrium is examined using a dynamical systems model in which quiescence and labor are represented as phase-space equilibrium points. Our model shows that PR-B transcriptional activity and the inflammatory load determine the stability of the quiescent and laboring phenotypes. The model is tested using published transcriptome datasets describing the mRNA abundances in the myometrium before and after the onset of labor at term. Surrogate transcripts were selected to reflect PR-B transcriptional activity and inflammation status. The model coupling PR-B activity and inflammation predicts contractile status (i.e., laboring or quiescent) with high precision and recall and outperforms uncoupled single and two-gene classifiers. Linear stability analysis shows that phase space bifurcations exist in our model that may reflect the phenotypic states of the pregnancy uterus. The model describes a possible tipping point for the transition of the quiescent to the contractile laboring phenotype. Our model describes the functional interaction between the PR-A:PR-B hypothesis and tissue level inflammation in the pregnancy uterus and is a first step in more sophisticated dynamical systems modeling of human partition. The model explains observed biochemical dynamics and as such will be useful for the development of a range of systems-based models using emerging data to predict preterm birth and identify strategies for its prevention.

High Wintertime Ozone in the Uinta Basin: Diurnal Mixing and Ozone Production Measured by Tethered Ozonesondes

NASA Astrophysics Data System (ADS)

Johnson, B.; Cullis, P.; Schnell, R. C.; Oltmans, S. J.; Sterling, C. W.; Jordan, A. F.; Hall, E.

2016-12-01

Extreme high ozone mixing ratios, far exceeding U.S. National Air Quality Standards, were observed in the Uinta Basin in January-February 2013 under conditions highly favorable for wintertime ozone production. Hourly average ozone mixing ratios increased from regional background levels of 40-50 ppbv to >160 ppbv during several multi-day episodes of prolonged temperature inversions over snow-covered ground within air confining topography. Extensive surface and tethered balloon profile measurements of ozone, meteorology, CH4, CO2, NO2 and a suite of non-methane hydrocarbons (NMHCs) link emissions from oil and natural gas extraction with the strong ozone production throughout the Basin. High levels of NMHCs that were well correlated with CH4 showed that abundant O3 precursors were available throughout the Basin where high ozone mixing ratios extended from the surface to the top of the inversion layer at 200 m above ground level. This layer was at a nearly uniform height across the Basin even though there are significant terrain variations. Tethered balloon measurements rising above the elevated levels of ozone within the cold pool layer beneath the inversion measured regional background O3 concentrations. Surface wind and direction data from tethered balloons showed a consistent diurnal pattern in the Basin that moved air with the highest levels of CH4 and ozone precursor NMHC's from the gas fields of the east-central portion of the Basin to the edges during the day, before draining back into the Basin at night.

LONG-TERM PERFORMANCE OF PERMEABLE REACTIVE BARRIERS: AN UPDATE ON A U.S. MULTI-AGENCY INITIATIVE

EPA Science Inventory

Permeable reactive barriers (PRB's) are an emerging, alternative in-situ approach for remediating contaminated groundwater that combine subsurface fluid flow management with a passive chemical treatment zone. PRB's are a potentially more cost effective treatment option at seve...

PLANT MULCH TO TREAT TCE IN GROUND WATER IN A PRB (ABSTRACT ONLY)

EPA Science Inventory

In the past ten years, passive reactive barriers (PRBs) have found widespread application to treat chlorinated solvent contamination in ground water. The traditional PRB commonly uses granular zero-valent iron and/or iron alloys as filling materials for treatment of chlorinated ...

Autochthonous tumors driven by Rb1 loss have an ongoing requirement for the RBP2 histone demethylase.

PubMed

McBrayer, Samuel K; Olenchock, Benjamin A; DiNatale, Gabriel J; Shi, Diana D; Khanal, Januka; Jennings, Rebecca B; Novak, Jesse S; Oser, Matthew G; Robbins, Alissa K; Modiste, Rebecca; Bonal, Dennis; Moslehi, Javid; Bronson, Roderick T; Neuberg, Donna; Nguyen, Quang-De; Signoretti, Sabina; Losman, Julie-Aurore; Kaelin, William G

2018-04-17

Inactivation of the retinoblastoma gene ( RB1 ) product, pRB, is common in many human cancers. Targeting downstream effectors of pRB that are central to tumorigenesis is a promising strategy to block the growth of tumors harboring loss-of-function RB1 mutations. One such effector is retinoblastoma-binding protein 2 (RBP2, also called JARID1A or KDM5A), which encodes an H3K4 demethylase. Binding of pRB to RBP2 has been linked to the ability of pRB to promote senescence and differentiation. Importantly, genetic ablation of RBP2 is sufficient to phenocopy pRB's ability to induce these cellular changes in cell culture experiments. Moreover, germline Rbp2 deletion significantly impedes tumorigenesis in Rb1 +/- mice. The value of RBP2 as a therapeutic target in cancer, however, hinges on whether loss of RBP2 could block the growth of established tumors as opposed to simply delaying their onset. Here we show that conditional, systemic ablation of RBP2 in tumor-bearing Rb1 +/- mice is sufficient to slow tumor growth and significantly extend survival without causing obvious toxicity to the host. These findings show that established Rb1 -null tumors require RBP2 for growth and further credential RBP2 as a therapeutic target in human cancers driven by RB1 inactivation.

Water-quality data from shallow pond-bottom groundwater in the Fishermans Cove area of Ashumet Pond, Cape Cod, Massachusetts, 2001–2010

USGS Publications Warehouse

McCobb, Timothy D.; LeBlanc, Denis R.

2011-01-01

The U.S. Geological Survey (USGS) collected water-quality data between 2001 and 2010 in the Fishermans Cove area of Ashumet Pond, Falmouth, Massachusetts, where the eastern portion of a treated-wastewater plume, created by more than 60 years of overland disposal, discharges to the pond. Temporary drive points were installed, and shallow pond-bottom groundwater was sampled, at 167 locations in 2001, 150 locations in 2003, and 120 locations in 2004 to delineate the distribution of wastewater-related constituents. In 2004, the Air Force Center for Engineering and the Environment (AFCEE) installed a pond-bottom permeable reactive barrier (PRB) to intercept phosphate in the plume at its discharge point to the pond. The USGS monitored the performance of the PRB by collecting samples from temporary drive points at multiple depth intervals in 2006 (200 samples at 76 locations) and 2009 (150 samples at 90 locations). During the first 5 years after installation of the PRB, water samples were collected periodically from five types of pore-water samplers that had been permanently installed in and near the PRB during the barrier's emplacement. The distribution of wastewater-related constituents in the pond-bottom groundwater and changes in the geochemistry of the pond-bottom groundwater after installation of the PRB have been documented in several published reports that are listed in the references.

Temporal and Spatial Variation in, and Population Exposure to, Summertime Ground-Level Ozone in Beijing

PubMed Central

Zheng, Youfei; Li, Ting; Wei, Li; Guan, Qing

2018-01-01

Ground-level ozone pollution in Beijing has been causing concern among the public due to the risks posed to human health. This study analyzed the temporal and spatial distribution of, and investigated population exposure to, ground-level ozone. We analyzed hourly ground-level ozone data from 35 ambient air quality monitoring sites, including urban, suburban, background, and traffic monitoring sites, during the summer in Beijing from 2014 to 2017. The results showed that the four-year mean ozone concentrations for urban, suburban, background, and traffic monitoring sites were 95.1, 99.8, 95.9, and 74.2 μg/m3, respectively. A total of 44, 43, 45, and 43 days exceeded the Chinese National Ambient Air Quality Standards (NAAQS) threshold for ground-level ozone in 2014, 2015, 2016, and 2017, respectively. The mean ozone concentration was higher in suburban sites than in urban sites, and the traffic monitoring sites had the lowest concentration. The diurnal variation in ground-level ozone concentration at the four types of monitoring sites displayed a single-peak curve. The peak and valley values occurred at 3:00–4:00 p.m. and 7:00 a.m., respectively. Spatially, ground-level ozone concentrations decreased in gradient from the north to the south. Population exposure levels were calculated based on ground-level ozone concentrations and population data. Approximately 50.38%, 44.85%, and 48.49% of the total population of Beijing were exposed to ground-level ozone concentrations exceeding the Chinese NAAQS threshold in 2014, 2015, and 2016, respectively. PMID:29596366

Temporal and Spatial Variation in, and Population Exposure to, Summertime Ground-Level Ozone in Beijing.

PubMed

Zhao, Hui; Zheng, Youfei; Li, Ting; Wei, Li; Guan, Qing

2018-03-29

Ground-level ozone pollution in Beijing has been causing concern among the public due to the risks posed to human health. This study analyzed the temporal and spatial distribution of, and investigated population exposure to, ground-level ozone. We analyzed hourly ground-level ozone data from 35 ambient air quality monitoring sites, including urban, suburban, background, and traffic monitoring sites, during the summer in Beijing from 2014 to 2017. The results showed that the four-year mean ozone concentrations for urban, suburban, background, and traffic monitoring sites were 95.1, 99.8, 95.9, and 74.2 μg/m³, respectively. A total of 44, 43, 45, and 43 days exceeded the Chinese National Ambient Air Quality Standards (NAAQS) threshold for ground-level ozone in 2014, 2015, 2016, and 2017, respectively. The mean ozone concentration was higher in suburban sites than in urban sites, and the traffic monitoring sites had the lowest concentration. The diurnal variation in ground-level ozone concentration at the four types of monitoring sites displayed a single-peak curve. The peak and valley values occurred at 3:00-4:00 p.m. and 7:00 a.m., respectively. Spatially, ground-level ozone concentrations decreased in gradient from the north to the south. Population exposure levels were calculated based on ground-level ozone concentrations and population data. Approximately 50.38%, 44.85%, and 48.49% of the total population of Beijing were exposed to ground-level ozone concentrations exceeding the Chinese NAAQS threshold in 2014, 2015, and 2016, respectively.

Ground Level Ozone Regional Background Characteristics In North-west Pacific Rim

NASA Astrophysics Data System (ADS)

Chiang, C.; Fan, J.; Chang, J. S.

2007-12-01

Understanding the ground level ozone regional background characteristics is essential in understanding the contribution of long-range transport of pollutants from Asia Mainland to air quality in downwind areas. In order to understand this characteristic in north-west Pacific Rim, we conducted a coupled study using ozone observation from regional background stations and 3-D regional-scale chemical transport model simulations. We used O3, CO, wind speed and wind direction data from two regional background stations and ¡§other stations¡¨ over a ten year period and organized several numerical experiments to simulate one spring month in 2003 to obtain a deeper understanding. The so called ¡§other stations¡¨ had actually been named as background stations under various governmental auspices. But we found them to be often under strong influence of local pollution sources with strong diurnal or slightly longer time variations. We found that the Yonagunijima station (24.74 N, 123.02 E) and Heng-Chuen station (21.96 N,120.78 E), about a distance of 400 km apart, have almost the same ozone time series pattern. For these two stations in 2003, correlation coefficients (R2) for annual observed ozone concentration is about 0.64, in the springtime it is about 0.7, and in a one-month period at simulation days it is about 0.76. These two stations have very little small scale variations in all the variables studied. All variations are associated with large scale circulation changes. This is especially so at Yonagunijima station. Using a 3-D regional-scale chemical transport model for East Asia region including contribution from Asia continental outflow and neighboring island pollution areas we found that the Yonagunijima and HengChuen station are indeed free of pollutants from all neighboring areas keeping in mind that pollutants from Taiwan area is never far away. Ozone concentrations in these two stations are dominated by synoptic scale weather patterns, with diffused pollutant contribution from distant sources. When the weather system brings in air mass from the low latitude of western Pacific Ocean, ozone concentrations are about 10-20 ppb. When the China high pressure system moves eastward and with the accompanying Asian continental outflow plume, ozone concentrations are about 65-80 ppb.

Low level ozone exposure induces airways inflammation and modifies cell surface phenotypes in healthy humans

EPA Science Inventory

Background: The effects of low level ozone exposure (0.08 ppm) on pulmonary function in healthy young adults are well known, however much less is known about the inflammatory and immuno-modulatory effects oflow level ozone in the airways. Techniques such as induced sputum and flo...

Impacts of different characterizations of large-scale background on simulated regional-scale ozone over the continental United States

EPA Science Inventory

This study analyzes simulated regional-scale ozone burdens both near the surface and aloft, estimates process contributions to these burdens, and calculates the sensitivity of the simulated regional-scale ozone burden to several key model inputs with a particular emphasis on boun...

Development of an Aura Chemical Reanalysis in support Air Quality Applications

NASA Astrophysics Data System (ADS)

Pierce, R. B.; Lenzen, A.; Schaack, T.

2015-12-01

We present results of chemical data assimilation experiments utilizing the NOAA National Environmental Satellite, Data, and Information Service (NESDIS), University of Wisconsin Space Science and Engineering (SSEC) Real-time Air Quality Modeling System (RAQMS) in conjunction with the NOAA National Centers for Environmental Prediction (NCEP) Operational Gridpoint Statistical Interpolation (GSI) 3-dimensional variational data assimilation system. The impact of assimilating NASA Ozone Monitoring Instrument (OMI) total column ozone, OMI tropospheric nitrogen dioxide columns, and Microwave Limb Sounder (MLS) stratospheric ozone profiles on background ozone is assessed using measurements from the 2010 NSF High-performance Instrumented Airborne Platform for Environmental Research (HIAPER) Pole-to-Pole Observation (HIPPO) and NOAA California Nexus (CalNex) campaigns. Results show that the RAQMS/GSI Chemical Reanalysis is able to provide very good estimates of background ozone and large-scale ozone variability and is suitable for use in constraining regional air quality modeling activities. These experiments are being used to guide the development of a multi-year global chemical and aerosol reanalysis using NASA Aura and A-Train measurements to support air quality applications.

75 FR 60125 - SES Performance Review Board

Federal Register 2010, 2011, 2012, 2013, 2014

2010-09-29

... FEDERAL TRADE COMMISSION SES Performance Review Board AGENCY: Federal Trade Commission. ACTION: Notice. SUMMARY: Notice is hereby given of the appointment of members to the FTC Performance Review Board... the Performance Review Board (PRB) membership is required by 5 U.S.C. 4314(c)(4). The PRB reviews and...

75 FR 68669 - Senior Executive Service; Departmental Performance Review Board

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-08

... DEPARTMENT OF THE TREASURY Senior Executive Service; Departmental Performance Review Board AGENCY: Treasury Department. ACTION: Notice. SUMMARY: Pursuant to 5 U.S.C. 4314(c)(4), this notice announces the appointment of members of the Departmental PRB. The purpose of this PRB is to review and make recommendations...

76 FR 64429 - Senior Executive Service; Public Debt Performance Review Board (PRB)

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-18

... DEPARTMENT OF THE TREASURY Bureau of the Public Debt Senior Executive Service; Public Debt Performance Review Board (PRB) AGENCY: Bureau of the Public Debt, Treasury. ACTION: Notice of Members of... reviews the performance appraisals of career senior executives who are below the level of Assistant...

78 FR 75447 - Senior Executive Service; Departmental Performance Review Board

Federal Register 2010, 2011, 2012, 2013, 2014

2013-12-11

... DEPARTMENT OF THE TREASURY Senior Executive Service; Departmental Performance Review Board AGENCY: Treasury Department. ACTION: Notice of members of the Departmental Performance Review Board (PRB). SUMMARY: Pursuant to 5 U.S.C. 4314(c)(4), this notice announces the appointment of members of the Departmental PRB...

75 FR 60864 - Senior Executive Service Combined Performance Review Board (PRB)

Federal Register 2010, 2011, 2012, 2013, 2014

2010-10-01

... DEPARTMENT OF THE TREASURY United States Mint Senior Executive Service Combined Performance Review Board (PRB) AGENCY: United States Mint, Department of the Treasury. ACTION: Notice. SUMMARY: Pursuant to... career senior executives below the level of bureau head and principal deputy in the bureaus, except for...

76 FR 69798 - Senior Executive Service; Departmental Performance Review Board

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-09

... DEPARTMENT OF THE TREASURY Senior Executive Service; Departmental Performance Review Board AGENCY: Treasury Department. ACTION: Notice of members of the Departmental Performance Review Board (PRB). SUMMARY: Pursuant to 5 U.S.C. 4314(c)(4), this notice announces the appointment of members of the Departmental PRB...

Performance Monitoring: Evaluating an Organic Carbon-Limestone PRB for Treatment of Heavy Metals and Acidity

EPA Science Inventory

Since 2004, researchers from the U.S. EPA National Risk Management Research Laboratory (NRMRL) have annually evaluated performance of an organic carbon-limestone permeable reactive barrier (PRB) system installed in 2003 by EPA Region 6 at the Delatte Metals Superfund site in Ponc...

Performance Monitoring: Evaluating a Wheat Straw PRB for Nitrate Removal at an Agricultural Operation

EPA Science Inventory

The U.S. EPA Office of Research and Development’s National Risk Management Research Laboratory (NRMRL) is conducting long-term monitoring of a wheat straw permeable reactive barrier (PRB) for remediation of ground water contaminated with nitrate from a now-closed swine concentrat...

75 FR 60090 - Membership of the Performance Review Board

Federal Register 2010, 2011, 2012, 2013, 2014

2010-09-29

...: Missile Defense Agency (MDA), DoD. ACTION: Notice. SUMMARY: This notice announces the appointment of the members of the Performance Review Board (PRB) of the Missile Defense Agency (MDA). The publication of PRB... CONTACT: Jovey Martir, MDA SES Program Management, Missile Defense Agency, Arlington, Virginia, (703) 693...

CHROMIUM REMOVAL PROCESSES DURING GROUNDWATER REMEDIATION BY A ZEROVALENT IRON PERMEABLE REACTIVE BARRIER

EPA Science Inventory

Solid-phase associations of chromium were examined in core materials collected from a full-scale, zerovalent iron, permeable reactive barrier (PRB) at the U.S. Coast Guard Support Center located near Elizabeth City (NC). The PRB was installed in 1996 to treat groundwater contami...

EFFECTIVE REMOVAL OF TCE IN A LABORATORY MODEL OF A PRB CONSTRUCTED WITH PLANT MULCH

EPA Science Inventory

In the past ten years, passive reactive barriers (PRBs) have found widespread application to treat chlorinated solvent contamination in ground water. The traditional PRB commonly uses granular zero-valent iron and/or iron alloys as filling materials for treatment of chlorinated ...

TREATMENT OF ARSENIC AND METALS IN GROUND WATER USING A COMPOST/ZVI PRB

EPA Science Inventory

A pilot permeable reactive barrier (PRB) consisting of a mixture of 30% yard waste compost, 20% zero-valent iron (ZVI), 5% limestone and 45% pea gravel by volume was installed at a former phosphate fertilizer manufacturing facility in Charleston, S.C. in September 2002. The pilo...

RESEARCH PROJECT -- PERMEABLE REACTIVE BARRIERS FOR REMEDIATION OF CONTAMINATED GROUNDWATERS(SUBSURFACE PROTECTION AND REMEDIATION DIVISION, (NRMRL)

EPA Science Inventory

Permeable reactive barrier (PRB) technology is gradually being accepted as a viable alternative to conventional groundwater remediation systems such as pump and treat. PRB technology involves the placement or formation of a reactive treatment zone in the path of a dissolved conta...

GWERD MONITORING OF PRB PERFORMANCE AT CIMARRON PORK FIELD SITE - UPDATE 2005

EPA Science Inventory

GWERD personnel have been invited to help evaluate the performance of a carbon-based permeable reactive barrier (PRB) that was constructed for in-situ bioremediation of a ground water nitrate plume caused by leakage from a swine CAFO lagoon. Research activities to date have invol...

75 FR 65673 - Appointments to Performance Review Board for Senior Executive Service

Federal Register 2010, 2011, 2012, 2013, 2014

2010-10-26

... appointed as members of the NRC Performance Review Board (PRB) responsible for making recommendations to the... Executives and Senior Level System employees: Darren B. Ash, Deputy Executive Director for Corporate... of the NRC PRB Panel that was established to review appraisals and make recommendations to the...

76 FR 18516 - Senior Executive Service; Combined Performance Review Board (PRB)

Federal Register 2010, 2011, 2012, 2013, 2014

2011-04-04

... performance appraisals of career and non-career senior executives. The Board recommendations regarding..., more than half of the members shall consist of career appointees. The names and titles of the PRB... Center, Bureau of Public Debt Debra L. Hines, Assistant Commissioner, Office of Public Debt Accounting...

STUDY OF MERCURY OXIDATION BY SCR CATALYST IN AN ENTRAINED-FLOW REACTOR UNDER SIMULATED PRB CONDITIONS

EPA Science Inventory

A bench-scale entrained-flow reactor system was constructed for studying elemental mercury oxidation under selective catalytic reduction (SCR) reaction conditions. Simulated flue gas was doped with fly ash collected from a subbituminous Powder River Basin (PRB) coal-fired boiler ...

Observations of Europe wide Trends in background and peak O3, CO and NO2 levels

NASA Astrophysics Data System (ADS)

Fleming, Z. L.; Monks, P. S.; Brunsdon, C.; Henne, S.; Buchmann, B.; Konovalov, I.; Beekman, M.

2009-04-01

The GEOMON (Global Earth Observation and MONitoring) project has produced a harmonised data set of trace gases from various ground-based measurement stations. These stations belong to a variety of regional, national and European air quality networks (e.g. EMEP, GAW). Investigations into instrumental calibration and data quality have been carried out in order to make comparison between the sites as accurate as possible for a long time-scale trend analysis. Ozone seasonal cycles at the various sites have been compared, showing characteristic cycles according to latitude, elevation, vicinity to coastal areas and pollution sources and population nearby. A de-trending of this seasonal cycle revealed long-term variations in ozone and a considerable difference between background and peak ozone trends between sites. National, European and international legislation has aimed at reducing CO and NO2 and correspondingly, reduce O3 levels over the last 20 years but the trends are not as clear cut and reveal that there is not a homogeneous reduction in these species across Europe. Splitting the data into seasonal periods and also into lower and upper concentration percentiles shows us more clearly how the species vary across Europe. There is a tendency for peak ozone levels to decrease, whilst the background levels have mostly increased. Averages, lower and upper percentiles of these species at the GEOMON stations are shown on European maps and the distribution of annual ozone trends is evaluated. Comparisons with models that estimate the lower and upper percentiles of ozone during summer overestimate ozone levels but not uniformly across Europe.

Airborne LIDAR Measurements of Aerosol and Ozone Above the Alberta Oil Sands Region

NASA Astrophysics Data System (ADS)

Aggarwal, M.; Whiteway, J. A.; Seabrook, J.; Gray, L. H.

2014-12-01

Lidar measurements of ozone and aerosol were conducted from a Twin Otter aircraft above the oil sands region of northern Alberta. The field campaign was carried out with a total of five flights out of Fort McMurray, Alberta during the period between August 22 and August 26, 2013. Significant amounts of aerosol were observed within the boundary layer, up to a height of 1.6 km, but the ozone concentration remained at or below background levels. On August 24th the lidar observed a separated layer of aerosol above the boundary layer, at a height of 1.8 km, in which the ozone mixing ratio increased to 70 ppbv. Backward trajectory calculations revealed that the air containing this separated aerosol layer had passed over an area of forest fires. Directly below the layer of forest fire smoke, in the pollution from the oil sands industry, the measured ozone mixing ratio was lower than the background levels (≤35 ppbv).

Interaction effects of temperature and ozone on lung function and markers of systemic inflammation, coagulation, and fibrinolysis: A crossover study of healthy young volunteers

EPA Science Inventory

BACKGROUND: Trends in climate suggest that extreme weather events such as heat waves will become more common. High levels of the gaseous pollutant ozone are associated with elevated temperatures. Ozone has been associated with respiratory diseases as well as cardiovascular morbid...

A Lagrangian analysis of the impact of transport and transformation on the ozone stratification observed in the free troposphere during the ESCOMPTE campaign

NASA Astrophysics Data System (ADS)

Colette, A.; Ancellet, G.; Menut, L.; Arnold, S. R.

2006-03-01

The ozone variability observed by tropospheric ozone lidars during the ESCOMPTE campaign is analyzed by means of a hybrid-Lagrangian modeling study. Transport processes responsible for the formation of ozone-rich layers are identified using a semi-Lagrangian analysis of mesoscale simulations to identify the planetary boundary layer (PBL) footprint in the free troposphere. High ozone concentrations are related to polluted air masses exported from the Iberian PBL. The chemical composition of air masses coming from the PBL and transported in the free troposphere is evaluated using a Lagrangian chemistry model. The initial concentrations are provided by a model of chemistry and transport. Different scenarios are tested for the initial conditions and for the impact of mixing with background air in order to perform a quantitative comparison with the lidar observations. For this meteorological situation, the characteristic mixing time is of the order of 2 to 5 days depending on the initial conditions. Ozone is produced in the free troposphere within most air masses exported from the Iberian PBL at an average rate of 0.2 ppbv h-1, with a maximum ozone production of 0.4 ppbv h-1. Transport processes from the PBL are responsible for an increase of 13.3 ppbv of ozone concentrations in the free troposphere compared to background levels; about 45% of this increase is attributed to in situ production during the transport rather than direct export of ozone.

A Lagrangian analysis of the impact of transport and transformation on the ozone stratification observed in the free troposphere during the ESCOMPTE campaign

NASA Astrophysics Data System (ADS)

Colette, A.; Ancellet, G.; Menut, L.; Arnold, S. R.

2006-08-01

The ozone variability observed by tropospheric ozone lidars during the ESCOMPTE campaign is analyzed by means of a hybrid-Lagrangian modeling study. Transport processes responsible for the formation of ozone-rich layers are identified using a semi-Lagrangian analysis of mesoscale simulations to identify the planetary boundary layer (PBL) footprint in the free troposphere. High ozone concentrations are related to polluted air masses exported from the Iberian PBL. The chemical composition of air masses coming from the PBL and transported in the free troposphere is evaluated using a Lagrangian chemistry model. The initial concentrations are provided by a model of chemistry and transport. Different scenarios are tested for the initial conditions and for the impact of mixing with background air in order to perform a quantitative comparison with the lidar observations. For this meteorological situation, the characteristic mixing time is of the order of 2 to 6 days depending on the initial conditions. Ozone is produced in the free troposphere within most air masses exported from the Iberian PBL at an average rate of 0.2 ppbv h-1, with a maximum ozone production of 0.4 ppbv h-1. Transport processes from the PBL are responsible for an increase of 13.3 ppbv of ozone concentrations in the free troposphere compared to background levels; about 45% of this increase is attributed to in situ production during the transport rather than direct export of ozone.

78 FR 73586 - Senior Executive Service Performance Review Board (PRB) and Executive Resources Board (ERB...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-12-06

...: Performance Review Board Leland L. Gardner, Chairman Rachel D. Campbell, Member Craig M. Keats, Member Lucille Marvin, Alternate Member Executive Resources Board Rachel D. Campbell, Chairman Lucille Marvin, Member Joseph H. Dettmar, Alternate Member These changes to the PRB and ERB membership are due to the departure...

TREATMENT OF METALS IN GROUND WATER USING AN ORGANIC-BASED SULFATE-REDUCING PERMEABLE REACTIVE BARRIER

EPA Science Inventory

A pilot permeable reactive barrier (PRB) consisting of a mixture of leaf compost, zero-valent iron (ZVI) filings, limestone and pea gravel was evaluated at a former phosphate fertilizer manufacturing facility in Charleston, S.C. The PRB is designed to treat arsenic and heavy met...

EFFECTIVE REMOVAL OF TCE IN A LABORATORY MODEL OF A PRB CONSTRUCTED WITH PLANT MULCH

EPA Science Inventory

Ground water contaminated with TCE is commonly treated with a permeable reactive barrier (PRB) constructed with zero-valence iron. The cost of iron as the reactive matrix has driven a search for less costly alternatives, and composted plant mulch has been used as an alternative ...

77 FR 65248 - Senior Executive Service; Public Debt Performance Review Board

Federal Register 2010, 2011, 2012, 2013, 2014

2012-10-25

... Performance Review Board AGENCY: Bureau of the Public Debt, Treasury. ACTION: Notice. SUMMARY: This notice announces the appointment of the members of the Public Debt Performance Review Board (PRB) for the Bureau of the Public Debt (BPD). The PRB reviews the performance appraisals of career senior executives who are...

77 FR 48129 - National Institute of Standards and Technology Performance Review Board Membership

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-13

... Institute of Standards and Technology Performance Review Board (NIST PRB) and supersedes the list published on September 9, 2011. DATES: The changes to the NIST PRB membership list announced in this notice are... Standards and Technology, (301) 975-3000 or by email at [email protected]nist.gov . SUPPLEMENTARY INFORMATION...

Status report: USGS coal assessment of the Powder River, Wyoming

USGS Publications Warehouse

Luppens, James A.; Rohrbacher, Timothy J.; Haacke, Jon E.; Scott, David C.; Osmonson, Lee M.

2006-01-01

Summary: This publication reports on the status of the current coal assessment of the Powder River Basin (PRB) in Wyoming and Montana. This slide program was presented at the Energy Information Agency's 2006 EIA Energy Outlook and Modeling Conference in Washington, DC, on March 27, 2006. The PRB coal assessment will be the first USGS coal assessment to include estimates of both regional coal resources and reserves for an entire coal basin. Extensive CBM and additional oil and gas development, especially in the Gillette coal field, have provided an unprecedented amount of down-hole geological data. Approximately 10,000 new data points have been added to the PRB database since the last assessment (2002) which will provide a more robust evaluation of the single most productive U.S. coal basin. The Gillette coal field assessment, including the mining economic evaluation, is planned for completion by the end of 2006. The geologic portion of the coal assessment work will shift to the northern and northwestern portions of the PRB before the end of 2006 while the Gillette engineering studies are finalized.

Sonic Hedgehog Initiates Cochlear Hair Cell Regeneration through Downregulation of Retinoblastoma Protein

PubMed Central

Lu, Na; Chen, Yan; Wang, Zhengmin; Chen, Guoling; Lin, Qin; Chen, Zheng-Yi; Li, Huawei

2013-01-01

Cell cycle re-entry by cochlear supporting cells and/or hair cells is considered one of the best approaches for restoring hearing loss as a result of hair cell damage. To identify mechanisms that can be modulated to initiate cell cycle re-entry and hair cell regeneration, we studied the effect of activating the sonic hedgehog (Shh) pathway. We show that Shh signaling in postnatal rat cochleae damaged by neomycin leads to renewed proliferation of supporting cells and hair cells. Further, proliferating supporting cells are likely to transdifferentiate into hair cells. Shh treatment leads to inhibition of retinoblastoma protein (pRb) by increasing phosphorylated pRb and reducing retinoblastoma gene transcription. This results in upregulation of cyclins B1, D2, and D3, and CDK1. These results suggest that Shh signaling induces cell cycle re-entry in cochlear sensory epithelium and the production of new hair cells, in part by attenuating pRb function. This study provides an additional route to modulate pRb function with important implications in mammalian hair cell regeneration. PMID:23211596

Low levels of PRB3 mRNA are associated with dopamine-agonist resistance and tumor recurrence in prolactinomas.

PubMed

Wang, Fei; Gao, Hua; Li, Chuzhong; Bai, Jiwei; Lu, Runchun; Cao, Lei; Wu, Yongtu; Hong, Lichuan; Wu, Yonggang; Lan, Xiaolei; Zhang, Yazhuo

2014-01-01

Prolactinomas, or prolactin-secreting adenomas, constitute the most common type of hyperfunctioning pituitary adenoma. Dopamine agonists are used as first-line medication for prolactinomas, but the tumors are resistant to the therapy in 5-18 % of patients. To explore potential mechanisms of resistance to bromocriptine (a dopamine agonist), we analyzed six responsive prolactinomas and six resistant prolactinomas by whole-exome sequencing. We identified ten genes with sequence variants that were differentially found in the two groups of tumors. The expression of these genes was then quantified by real-time reverse-transcription PCR (RT-qPCR) in the 12 prolactinomas and in six normal pituitary glands. The mRNA levels of one of the genes, PRB3, were about fourfold lower in resistant prolactinomas than in the responsive tumors (p = 0.02). Furthermore, low PRB3 expression was also associated with tumor recurrence. Our results suggest that low levels of PRB3 mRNA may have a role in dopamine-agonist resistance and tumor recurrence of prolactinomas.

Impact of volcanic aerosols on stratospheric ozone recovery

NASA Astrophysics Data System (ADS)

Naik, Vaishali; Horowitz, Larry W.; Daniel Schwarzkopf, M.; Lin, Meiyun

2017-09-01

We use transient GFDL-CM3 chemistry-climate model simulations over the 2006-2100 period to show how the influence of volcanic aerosols on the extent and timing of ozone recovery varies with (a) future greenhouse gas scenarios (Representative Concentration Pathway (RCP)4.5 and RCP8.5) and (b) halogen loading. Current understanding is that elevated volcanic aerosols reduce ozone under high halogen loading but increase ozone under low halogen loading when the chemistry is more NOx dominated. With extremely low aerosol loadings (designated here as "background"), global stratospheric ozone burden is simulated to return to 1980 levels around 2050 in the RCP8.5 scenario but remains below 1980 levels throughout the 21st century in the RCP4.5 scenario. In contrast, with elevated volcanic aerosols, ozone column recovers more quickly to 1980 levels, with recovery dates ranging from the mid-2040s in RCP8.5 to the mid-2050s to early 2070s in RCP4.5. The ozone response in both future emission scenarios increases with enhanced volcanic aerosols. By 2100, the 1980 baseline-adjusted global stratospheric ozone column is projected to be 20-40% greater in RCP8.5 and 110-200% greater in RCP4.5 with elevated volcanic aerosols compared to simulations with the extremely low background aerosols. The weaker ozone enhancement at 2100 in RCP8.5 than in RCP4.5 in response to elevated volcanic aerosols is due to a factor of 2.5 greater methane in RCP8.5 compared with RCP4.5. Our results demonstrate the substantial uncertainties in stratospheric ozone projections and expected recovery dates induced by volcanic aerosol perturbations that need to be considered in future model ozone projections.

Origin of the phagocytic respiratory burst and its role in gut epithelial phagocytosis in a basal chordate.

PubMed

Yang, Ping; Huang, Shengfeng; Yan, Xinyu; Huang, Guangrui; Dong, Xiangru; Zheng, Tingting; Yuan, Dongjuan; Wang, Ruihua; Li, Rui; Tan, Ying; Xu, Anlong

2014-05-01

The vertebrate phagocytic respiratory burst (PRB) is a highly specific and efficient mechanism for reactive oxygen species (ROS) production. This mechanism is mediated by NADPH oxidase 2 (NOX2) and used by vertebrate phagocytic leukocytes to destroy internalized microbes. Here we demonstrate the presence of the PRB in a basal chordate, the amphioxus Branchiostoma belcheri tsingtauense (bbt). We show that using the antioxidant NAC to scavenge the production of ROS significantly decreased the survival rates of infected amphioxus, indicating that ROS are indispensable for efficient antibacterial responses. Amphioxus NOX enzymes and cytosolic factors were found to colocalize in the epithelial cells of the gill, intestine, and hepatic cecum and could be upregulated after exposure to microbial pathogens. The ROS production in epithelial cell lysates could be reconstructed by supplementing recombinant cytosolic factors, including bbt-p47phox, bbt-p67phox, bbt-p47phox, and bbt-Rac; the restored ROS production could be inhibited by anti-bbt-NOX2 and anti-bbt-p67phox antibodies. We also reveal that the gut epithelial lining cells of the amphioxus are competent at bacterial phagocytosis, and there is evidence that the PRB machinery could participate in the initiation of this phagocytic process. In conclusion, we report the presence of the classical PRB machinery in nonvertebrates and provide the first evidence for the possible role of PRB in epithelial cell immunity and phagocytosis. Copyright © 2014 Elsevier Inc. All rights reserved.

Progesterone receptor (PR) polyproline domain (PPD) mediates inhibition of epidermal growth factor receptor (EGFR) signaling in non-small cell lung cancer cells.

PubMed

Kawprasertsri, Sornsawan; Pietras, Richard J; Marquez-Garban, Diana C; Boonyaratanakornkit, Viroj

2016-05-01

Recent evidence has suggested a possible role for progesterone receptor (PR) in the progression of non-small cell lung cancer (NSCLC). However, little is known concerning roles of PR in NSCLC. PR contains a polyproline domain (PPD), which directly binds to the SH3 domain of signaling molecules. Because PPD-SH3 interactions are essential for EGFR signaling, we hypothesized that the presence of PR-PPD interfered with EGFR-mediated signaling and cell proliferation. We examined the role of PR-PPD in cell proliferation and signaling by stably expressing PR-B, or PR-B with disrupting mutations in the PPD (PR-BΔSH3), from a tetracycline-regulated promoter in A549 NSCLC cells. PR-B dose-dependently inhibited cell growth in the absence of ligand, and progestin (R5020) treatment further suppressed the growth. Treatment with RU486 abolished PR-B- and R5020-mediated inhibition of cell proliferation. Expression of PR-BΔSH3 and treatment with R5020 or RU486 had no effect on cell proliferation. Furthermore, PR-B expression but not PR-BΔSH3 expression reduced EGF-induced A549 proliferation and activation of ERK1/2, in the absence of ligand. Taken together, our data demonstrated the significance of PR extranuclear signaling through PPD interactions in EGFR-mediated proliferation and signaling in NSCLC. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Localization of estrogen receptor α and progesterone receptor B in bovine cervix and vagina during the follicular and luteal phases of the sexual cycle.

PubMed

Sağsöz, H; Akbalik, M E; Saruhan, B G; Ketani, M A

2011-08-01

The localization and distribution of estrogen receptors (ERα) and progesterone receptors (PR-B) in the cervix and vagina of sexually mature bovines during the follicular and luteal phases of the sexual cycle were studied using immunohistochemistry. The estrous cycle stage of 23 Holstein bovines was assessed by gross and histological appearance of ovaries and blood steroid hormone values. Tissue samples from cervix and vagina were fixed in 10% formaldehyde for routine histological processing. Nuclear staining for ERα and PR-B was observed in the epithelial cells of the surface epithelium, stromal cells and smooth muscle cells. Generally, in the cervix, ERα immunoreactivity was more intense in the epithelial and smooth muscle cells during the follicular phase and in the epithelial cells during the luteal phase (p < 0.05). PR-B immunoreactivity was more intense in the epithelial and smooth muscle cells than in the superficial and deep stromal cells during the follicular and luteal phases (p < 0.05). In the vagina, ERα and PR-B immunoreactivities were more intense in the epithelial cells than in the connective tissue cells and smooth muscle cells during the follicular and luteal phases (p < 0.05). These results indicated that the frequency and intensity of ERα and PR-B immunoreactivity in the cervix and vagina of bovines varied according to the cervical and vaginal cell types and the phases of the sexual cycle.

Targeted drug delivery and enhanced intracellular release using functionalized liposomes

NASA Astrophysics Data System (ADS)

Garg, Ashish

The ability to target cancer cells using an appropriate drug delivery system can significantly reduce the associated side effects from cancer therapies and can help in improving the overall quality of life, post cancer survival. Integrin alpha5beta1 is expressed on several types of cancer cells, including colon cancer and plays an important role in tumor growth and metastasis. Thus, the ability to target the integrin alpha 5beta1 using an appropriate drug delivery nano-vector can significantly help in inhibiting tumor growth and reducing tumor metastasis. The work in this thesis focuses on designing and optimizing, functionalized stealth liposomes (liposomes covered with polyethylene glycol (PEG)) that specifically target the integrin alpha5beta1. The PEG provides a steric barrier allowing the liposomes to circulate in the blood for longer duration and the functionalizing moiety, PR_b peptide specifically recognizes and binds to integrin alpha5beta1 expressing cells. The work demonstrates that by optimizing the amount of PEG and PR_b on the liposomal interface, nano-vectors can be engineered that bind to CT26.WT colon cancer cells in a specific manner and internalize through alpha 5beta1-mediated endocytosis. To further improve the efficacy of the system, PR_b functionalized pH-sensitive stealth liposomes that exhibit triggered release under mild acidic conditions present in endocytotic vesicles were designed. The study showed that PR_b functionalized pH-sensitive stealth liposomes, undergo destabilization under mildly acidic conditions and incorporation of the PR_b peptide does not significantly affect the pH-sensitivity of the liposomes. PR_b functionalized pH-sensitive stealth liposomes bind to CT26.WT colon carcinoma cells that express integrin alpha5beta 1, undergo cellular internalization, and release their load intracellularly in a short period of time as compared to other formulations. PR_b-targeted pH-sensitive stealth liposomes encapsulating 5-fluorouracil (5-FU) show significantly higher cytotoxicity than the PR_b-targeted inert stealth liposomes and the non-targeted stealth liposomes (both pH-sensitive and inert). The studies demonstrated that optimized PR_b functionalized pH sensitive liposomes have the potential to deliver a payload, such as chemotherapeutic agents, directly to colon cancer cells in an efficient and specific manner.

The Use of Multi-Component Statistical Techniques in Understanding Subduction Zone Arc Granitic Geochemical Data Sets

NASA Astrophysics Data System (ADS)

Pompe, L.; Clausen, B. L.; Morton, D. M.

2015-12-01

Multi-component statistical techniques and GIS visualization are emerging trends in understanding large data sets. Our research applies these techniques to a large igneous geochemical data set from southern California to better understand magmatic and plate tectonic processes. A set of 480 granitic samples collected by Baird from this area were analyzed for 39 geochemical elements. Of these samples, 287 are from the Peninsular Ranges Batholith (PRB) and 164 from part of the Transverse Ranges (TR). Principal component analysis (PCA) summarized the 39 variables into 3 principal components (PC) by matrix multiplication and for the PRB are interpreted as follows: PC1 with about 30% of the variation included mainly compatible elements and SiO2 and indicates extent of differentation; PC2 with about 20% of the variation included HFS elements and may indicate crustal contamination as usually identified by Sri; PC3 with about 20% of the variation included mainly HRE elements and may indicate magma source depth as often diplayed using REE spider diagrams and possibly Sr/Y. Several elements did not fit well in any of the three components: Cr, Ni, U, and Na2O.For the PRB, the PC1 correlation with SiO2 was r=-0.85, the PC2 correlation with Sri was r=0.80, and the PC3 correlation with Gd/Yb was r=-0.76 and with Sr/Y was r=-0.66 . Extending this method to the TR, correlations were r=-0.85, -0.21, -0.06, and -0.64, respectively. A similar extent of correlation for both areas was visually evident using GIS interpolation.PC1 seems to do well at indicating differentiation index for both the PRB and TR and correlates very well with SiO2, Al2O3, MgO, FeO*, CaO, K2O, Sc, V, and Co, but poorly with Na2O and Cr. If the crustal component is represented by Sri, PC2 correlates well and less expesively with this indicator in the PRB, but not in the TR. Source depth has been related to the slope on REE spidergrams, and PC3 based on only the HREE and using the Sr/Y ratios gives a reasonable correlation for both PRB and TR, but the Gd/Yb ratio gives a reasonable correlation for only the PRB. The PRB data provide reasonable correlation between principal components and standard geochemical indicators, perhaps because of the well-recognized monotonic variation from SW to NE. Data sets from the TR give similar results in some cases, but poor correlation in others.

Characterization of Wind Patterns over Texas Using Self-Organizing Maps: Impact on Dallas-Fort Worth Long Term Ozone Trends

NASA Astrophysics Data System (ADS)

Kotsakis, A.; Choi, Y.; Souri, A.; Jeon, W.; Flynn, J. H., III

2017-12-01

From the years 2000 to 2014, Dallas-Fort Worth (DFW) has seen a decrease in ozone exceedances due to decreased emissions of ozone precursors. In this study, a wind pattern analysis was done to gain a better understanding of the meteorological patterns that have historically contributed to ozone exceedances over the DFW area. Long-term trends in ozone and the seasonal distribution of ozone exceedances were analyzed using surface monitoring data. Using a clustering algorithm called self-organizing maps, characteristic regional wind patterns from 2000-2014 were determined. For each of the wind pattern clusters, the frequency over the last 15 years and average ozone from monitors across DFW was analyzed. Finally, model simulations were performed to determine if pollution transported out of Houston affected incoming background ozone into DFW.

A Madden-Julian Oscillation in Tropospheric Ozone

NASA Technical Reports Server (NTRS)

Ziemke, J. R.; Chandra, S.

2003-01-01

This is the first study to indicate a Madden-Julian Oscillation (MJO) in tropospheric ozone. Tropospheric ozone is derived using differential measurements of total column ozone and stratospheric column ozone measured from total ozone mapping spectrometer (TOMS) and microwave limb sounder (MLS) instruments. Two broad regions of significant MJO signal are identified in the tropics, one in the western Pacific and the other in the eastern Pacific. Over both regions, MJO variations in tropospheric ozone represent 5-10 Dobson Unit (DU) peak-to-peak anomalies. These variations are significant compared to mean background amounts of 20 DU or less over most of the tropical Pacific. MJO signals of this magnitude would need to be considered when investigating and interpreting particular pollution events since ozone is a precursor of the hydroxyl (OH) radical, the main oxidizing agent of pollutants in the lower atmosphere.

Making the Marine Corps Reserve Truly Operational: A Case Study in the Reorganization of the Marine Corps Reserve

DTIC Science & Technology

2012-05-10

Military’s Reliance on the Reserves”, PRB March 2005, http://www.prb.org/Articles/2005/USMilitarysRelianceontheReserves 30 Purpura , Paul. “Transfer of...March 20, 2009. Purpura , Paul. “Transfer of Marine Corps facility in New Orleans nears completion”, The Times Picayune. May 30, 2011. http

77 FR 60106 - Membership of the National Oceanic and Atmospheric Administration Performance Review Board

Federal Register 2010, 2011, 2012, 2013, 2014

2012-10-02

... Administration (NOAA), Department of Commerce (DOC). ACTION: Notice of Membership of the NOAA Performance Review Board. SUMMARY: In accordance with 5 U.S.C. 4314(c)(4), NOAA announces the appointment of members who will serve on the NOAA Performance Review Board (PRB). The NOAA PRB is responsible for reviewing...

Impact of iodine chemistry on coastal ozone levels at the Gulf of Mexico

NASA Astrophysics Data System (ADS)

Tuite, K.; Stutz, J.; Brockway, N.; Colosimo, S. F.; Tsai, J. Y.; Grossmann, K.; Alvarez, S. L.; Flynn, J. H., III; Erickson, M.; Caicedo, V.; Griffin, R. J.; Wallace, H. W., IV; Schulze, B.; Sheesley, R. J.; Usenko, S.; Yarwood, G.; Nopmongcol, U.

2016-12-01

Reactive iodine (Ix = I + IO) is known to destroy ozone through catalytic cycles in the marine boundary layer (MBL) and can thus have a significant impact on tropospheric ozone in coastal regions. As air quality standards for ozone become stricter, accurate background levels are increasingly important for the development of ozone reduction strategies. The Texas Gulf coast is an example for the significance of MBL background ozone, as onshore flows from the Gulf of Mexico contribute to the ozone levels in Houston and other coastal areas. The Gulf coast often experiences ozone mixing ratios below 20 ppb during summer onshore flow conditions, which are currently overestimated by regional and global air quality models. Modeling with the Comprehensive Air quality Model with extensions (CAMx) and GEOS-Chem including halogen chemistry identified iodine emissions from the Gulf of Mexico as a possible explanation. However, ambient measurements of Ix species for the Gulf of Mexico are needed to test this hypothesis and, if confirmed, refine models. We measured IO, O3, and other trace gases at the Gulf coast near Galveston, TX, using UCLA's long path DOAS instrument and a suite of in-situ instruments. During the study period from May 15 through July 12, 2016, several multi-day events with MBL ozone levels below 20 ppb were encountered. Here we present the observational data with a focus on time periods with onshore flow from the Gulf. A chemical steady state analysis will be used to assess whether the observed Ix mixing ratios can explain these low ozone mixing ratios. Our results will be compared to the CAMx and GEOS-Chem model simulations.

ck2-dependent phosphorylation of progesterone receptors (PR) on Ser81 regulates PR-B isoform-specific target gene expression in breast cancer cells.

PubMed

Hagan, Christy R; Regan, Tarah M; Dressing, Gwen E; Lange, Carol A

2011-06-01

Progesterone receptors (PR) are critical mediators of mammary gland development and contribute to breast cancer progression. Progestin-induced rapid activation of cytoplasmic protein kinases leads to selective regulation of growth-promoting genes by phospho-PR species. Herein, we show that phosphorylation of PR Ser81 is ck2 dependent and progestin regulated in intact cells but also occurs in the absence of PR ligands when cells enter the G(1)/S phase of the cell cycle. T47D breast cancer cells stably expressing a PR-B mutant receptor that cannot be phosphorylated at Ser79/81 (S79/81A) formed fewer soft agar colonies. Regulation of selected genes by PR-B, but not PR-A, also required Ser79/81 phosphorylation for basal and/or progestin-regulated (BIRC3, HSD11β2, and HbEGF) expression. Additionally, wild-type (wt) PR-B, but not S79/81A mutant PR, was robustly recruited to a progesterone response element (PRE)-containing transcriptional enhancer region of BIRC3; abundant ck2 also associated with this region in cells expressing wt but not S79/81A PR. We conclude that phospho-Ser81 PR provides a platform for ck2 recruitment and regulation of selected PR-B target genes. Understanding how ligand-independent PRs function in the context of high levels of kinase activities characteristic of breast cancer is critical to understanding the basis of tumor-specific changes in gene expression and will speed the development of highly selective treatments.

ck2-Dependent Phosphorylation of Progesterone Receptors (PR) on Ser81 Regulates PR-B Isoform-Specific Target Gene Expression in Breast Cancer Cells ▿

PubMed Central

Hagan, Christy R.; Regan, Tarah M.; Dressing, Gwen E.; Lange, Carol A.

2011-01-01

Progesterone receptors (PR) are critical mediators of mammary gland development and contribute to breast cancer progression. Progestin-induced rapid activation of cytoplasmic protein kinases leads to selective regulation of growth-promoting genes by phospho-PR species. Herein, we show that phosphorylation of PR Ser81 is ck2 dependent and progestin regulated in intact cells but also occurs in the absence of PR ligands when cells enter the G1/S phase of the cell cycle. T47D breast cancer cells stably expressing a PR-B mutant receptor that cannot be phosphorylated at Ser79/81 (S79/81A) formed fewer soft agar colonies. Regulation of selected genes by PR-B, but not PR-A, also required Ser79/81 phosphorylation for basal and/or progestin-regulated (BIRC3, HSD11β2, and HbEGF) expression. Additionally, wild-type (wt) PR-B, but not S79/81A mutant PR, was robustly recruited to a progesterone response element (PRE)-containing transcriptional enhancer region of BIRC3; abundant ck2 also associated with this region in cells expressing wt but not S79/81A PR. We conclude that phospho-Ser81 PR provides a platform for ck2 recruitment and regulation of selected PR-B target genes. Understanding how ligand-independent PRs function in the context of high levels of kinase activities characteristic of breast cancer is critical to understanding the basis of tumor-specific changes in gene expression and will speed the development of highly selective treatments. PMID:21518957

Pocket Proteins Suppress Head and Neck Cancer

PubMed Central

Shin, Myeong-Kyun; Pitot, Henry C.; Lambert, Paul F.

2012-01-01

Head and neck squamous cell carcinomas (HNSCC) is a common cancer in humans long known to be caused by tobacco and alcohol use, but now an increasing percentage of HNSCC is recognized to be caused by the same human papillomaviruses (HPVs) that cause cervical and other anogenital cancers. HPV-positive HNSCCs differ remarkably from HPV-negative HNSCCs in their clinical response and molecular properties. From studies in mice, we know that E7 is the dominant HPV oncoprotein in head and neck cancer. E7 is best known for its ability to inactivate pRb, the product of the retinoblastoma tumor susceptibility gene. However loss of pRb function does not fully account for E7’s potency in causing head and neck cancer. In this study, we characterized the cancer susceptibility of mice deficient in the expression of pRb and either of two related “pocket” proteins, p107 and p130, that are also inactivated by E7. pRb/p107 deficient mice developed head and neck cancer as frequently as do HPV16 E7 transgenic mice. The head and neck epithelia of the pRb/p107 deficient mice also displayed the same acute phenotypes and biomarker readouts as observed in the epithelia of E7 transgenic mice. Mice deficient for pRb and p130 in their head and neck epithelia showed intermediate acute and tumor phenotypes. We conclude that pRb and p107 act together to efficiently suppress head and neck cancer, and are therefore highly relevant targets of HPV16 E7 in its contribution to HPV-positive HNSCC. PMID:22237625

Pocket proteins suppress head and neck cancer.

PubMed

Shin, Myeong-Kyun; Pitot, Henry C; Lambert, Paul F

2012-03-01

Head and neck squamous cell carcinomas (HNSCC) is a common cancer in humans long known to be caused by tobacco and alcohol use, but now an increasing percentage of HNSCC is recognized to be caused by the same human papillomaviruses (HPV) that cause cervical and other anogenital cancers. HPV-positive HNSCCs differ remarkably from HPV-negative HNSCCs in their clinical response and molecular properties. From studies in mice, we know that E7 is the dominant HPV oncoprotein in head and neck cancer. E7 is best known for its ability to inactivate pRb, the product of the retinoblastoma tumor susceptibility gene. However, loss of pRb function does not fully account for potency of E7 in causing head and neck cancer. In this study, we characterized the cancer susceptibility of mice deficient in the expression of pRb and either of two related "pocket" proteins, p107 and p130, that are also inactivated by E7. pRb/p107-deficient mice developed head and neck cancer as frequently as do HPV-16 E7 transgenic mice. The head and neck epithelia of the pRb/p107-deficient mice also displayed the same acute phenotypes and biomarker readouts as observed in the epithelia of E7 transgenic mice. Mice deficient for pRb and p130 in their head and neck epithelia showed intermediate acute and tumor phenotypes. We conclude that pRb and p107 act together to efficiently suppress head and neck cancer and are, therefore, highly relevant targets of HPV-16 E7 in its contribution to HPV-positive HNSCC.

A Two-Timescale Response to Ozone Depletion: Importance of the Background State

NASA Astrophysics Data System (ADS)

Seviour, W.; Waugh, D.; Gnanadesikan, A.

2015-12-01

It has been recently suggested that the response of Southern Ocean sea-ice extent to stratospheric ozone depletion is time-dependent; that the ocean surface initially cools due to enhanced northward Ekman drift caused by a poleward shift in the eddy-driven jet, and then warms after some time due to upwelling of warm waters from below the mixed layer. It is therefore possible that ozone depletion could act to favor a short-term increase in sea-ice extent. However, many uncertainties remain in understanding this mechanism, with different models showing widely differing time-scales and magnitudes of the response. Here, we analyze an ensemble of coupled model simulations with a step-function ozone perturbation. The two-timescale response is present with an approximately 30 year initial cooling period. The response is further shown to be highly dependent upon the background ocean temperature and salinity stratification, which is influenced by both natural internal variability and the isopycnal eddy mixing parameterization. It is suggested that the majority of inter-model differences in the Southern Ocean response to ozone depletion is caused by differences in stratification.

Surface ozone in the Southern Hemisphere: 20 years of data from a site with a unique setting in El Tololo, Chile

NASA Astrophysics Data System (ADS)

Anet, Julien G.; Steinbacher, Martin; Gallardo, Laura; Velásquez Álvarez, Patricio A.; Emmenegger, Lukas; Buchmann, Brigitte

2017-05-01

The knowledge of surface ozone mole fractions and their global distribution is of utmost importance due to the impact of ozone on human health and ecosystems and the central role of ozone in controlling the oxidation capacity of the troposphere. The availability of long-term ozone records is far better in the Northern than in the Southern Hemisphere, and recent analyses of the seven accessible records in the Southern Hemisphere have shown inconclusive trends. Since late 1995, surface ozone is measured in situ at "El Tololo", a high-altitude (2200 m a.s.l.) and pristine station in Chile (30° S, 71° W). The dataset has been recently fully quality controlled and reprocessed. This study presents the observed ozone trends and annual cycles and identifies key processes driving these patterns. From 1995 to 2010, an overall positive trend of ˜ 0.7 ppb decade-1 is found. Strongest trends per season are observed in March and April. Highest mole fractions are observed in late spring (October) and show a strong correlation with ozone transported from the stratosphere down into the troposphere, as simulated with a model. Over the 20 years of observations, the springtime ozone maximum has shifted to earlier times in the year, which, again, is strongly correlated with a temporal shift in the occurrence of the maximum of simulated stratospheric ozone transport at the site. We conclude that background ozone at El Tololo is mainly driven by stratospheric intrusions rather than photochemical production from anthropogenic and biogenic precursors. The major footprint of the sampled air masses is located over the Pacific Ocean. Therefore, due to the negligible influence of local processes, the ozone record also allows studying the influence of El Niño and La Niña episodes on background ozone levels in South America. In agreement with previous studies, we find that, during La Niña conditions, ozone mole fractions reach higher levels than during El Niño conditions.

Protective role of interleukin-10 in Ozone-induced pulmonary inflammation**

EPA Science Inventory

Background: The mechanisms underlying ozone (03)-induced pulmonary inflammation remain unclear. Interleukin-10 (IL-10) is an anti-inflammatory cytokine that is known to inhibit inflammatory mediators. Objectives: We investigated the molecular mechanisms underlying interleuken-10...

The RB-related gene Rb2/p130 in neuroblastoma differentiation and in B-myb promoter down-regulation.

PubMed

Raschellà, G; Tanno, B; Bonetto, F; Negroni, A; Claudio, P P; Baldi, A; Amendola, R; Calabretta, B; Giordano, A; Paggi, M G

1998-05-01

The retinoblastoma family of nuclear factors is composed of RB, the prototype of the tumour suppressor genes and of the strictly related genes p107 and Rb2/p130. The three genes code for proteins, namely pRb, p107 and pRb2/p130, that share similar structures and functions. These proteins are expressed, often simultaneously, in many cell types and are involved in the regulation of proliferation and differentiation. We determined the expression and the phosphorylation of the RB family gene products during the DMSO-induced differentiation of the N1E-115 murine neuroblastoma cells. In this system, pRb2/p130 was strongly up-regulated during mid-late differentiation stages, while, on the contrary, pRb and p107 resulted markedly decreased at late stages. Differentiating N1E-115 cells also showed a progressive decrease in B-myb levels, a proliferation-related protein whose constitutive expression inhibits neuronal differentiation. Transfection of each of the RB family genes in these cells was able, at different degrees, to induce neuronal differentiation, to inhibit [3H]thymidine incorporation and to down-regulate the activity of the B-myb promoter.

Negative Effects of SRD5A1 on Nuclear Activity of Progesterone Receptor Isoform B in JEG3 Cells.

PubMed

Miao, Zhuo; Sun, Min; Jiang, Feng; Yao, Yuanqing; Li, Yi

2016-02-01

Progesterone withdrawal signals labor in mammals. Elevated intracellular metabolism contributes to progesterone functional withdrawal through unknown mechanism, which is thought to act via progesterone receptor (PR). This study aims to investigate molecular mechanisms underlying progesterone withdrawal during pregnancy and labor. We investigated the role of 5α-reductase type I (SRD5A1) in enzymatic catalysis of progesterone and loss of PR function in a human trophoblast choriocarcinoma cell line JEG3. The PR isoform B (PR-B) was robustly expressed in JEG3 cells. The SRD5A1 small-interfering RNA knockdown led to significant increase in PR-B nuclear import, ectopic, whereas SRD5A1 overexpression resulted in remarkable inhibition of nuclear PR-B in P4-treated cells. Repression of SRD5A1 activated PR-B responsive gene, whereas overexpression of SRD5A1 possessed an inhibitory effect. JEG3 cell line is a valuable tool to study mechanisms responsible for loss of PR function and screening of drugs for preterm birth treatment. Our study aims to investigate the molecular mechanisms underlying progesterone withdrawal during pregnancy and labor. © The Author(s) 2015.

Heavy metal removal from MSWI fly ash by electrokinetic remediation coupled with a permeable activated charcoal reactive barrier

PubMed Central

Huang, Tao; Li, Dongwei; Kexiang, Liu; Zhang, Yuewei

2015-01-01

This paper presents the investigations into the feasibility of the application of a remediation system that couples electrokinetic remediation (EKR) with the permeable reactive barrier (PRB) concept for municipal solid waste incineration (MSWI) fly ash with activated charcoal as the PRB material. The experimental results of this study showed that the proposed combined method can effectively improve the remediation efficiency and that the addition of the oxalic acid to the PRB media before the coupled system can further enhance the remediation process. In the optimization tests, the maximum removals of Zn, Pb, Cu and Cd were achieved under different experimental conditions. The voltage gradient and processing time were shown to have significant effects on the removal of Cu and Cd, whereas the addition of the oxalic acid had a more significant influence on the removal of Pb. Generally, the processing time is the most significant factor in changing the removal rates of HMs in the enhanced coupled system. In terms of the leaching toxicity, the specimen remediated by ENEKR + PRB showed the lowest leaching value for each HM in the S2 and S3 regions. PMID:26486449

Frontier Science in the Polar Regions: Current Activities of the Polar Research Board

NASA Astrophysics Data System (ADS)

Brown, L. M.

2011-12-01

The National Academies (the umbrella term for the National Academy of Sciences, National Academy of Engineering, Institute of Medicine, and National Research Council) is a private, nonprofit organization chartered by Congress in 1863. The Polar Research Board (PRB) is the focal point within the Academies for providing advice on issues related to the Arctic, Antarctic, and cold regions in general. Tasks within the PRB mission include: providing a forum for the polar science community to address research needs and policy issues; conducting studies and workshops on emerging scientific and policy issues in response to requests from federal agencies and others; providing program reviews, guidance, and assessments of priorities; and facilitating communication on polar issues among academia, industry, and government. The PRB also serves as the US National Committee to two international, nongovernmental polar science organizations: the Scientific Committee on Antarctic Research (SCAR) and the International Arctic Science Committee (IASC). The polar regions are experiencing rapid changes in environment and climate, and the PRB has a number of completed and ongoing studies that will enhance scientific understanding of these issues. This poster will illustrate current PRB activities as well as results from two recently released reports: Frontiers in Understanding Climate Change and Polar Ecosystems and Future Science Opportunities in Antarctica and the Southern Ocean. In the former, a set of frontier research questions are developed to help scientists understand the impacts of climate change on polar ecosystems. The report builds on existing knowledge of climate change impacts and highlights the next big topics to be addressed in the coming decades. In addition, a number of methods and technologies are identified that will be useful to advance future research in polar ecosystem science. In the latter, changes to important science conducted on Antarctica and the surrounding Southern Ocean will be summarized. The report will identify the anticipated types and scope of US scientific programs in the region over the next two decades. It will also examine opportunities for international Antarctic scientific collaborations and report any new and emerging technologies. Through these reports, ongoing studies and workshops, and various outreach methods, the PRB plays an important role in dissemination of polar science, both in the United States and internationally. For example, the PRB played a critical role in planning the International Polar Year (IPY) 2007-2008 and is currently conducting a synthesis study called Legacies and Lessons of IPY 2007-2008. The report will be informed by a large community workshop and will examine what was learned and how the many pieces of IPY combine to move polar understanding forward in the future. Other PRB reports (e.g., Scientific Value of Arctic Sea Ice Imagery Derived Products and Toward an Integrated Arctic Observing Network) have also had important implications for current and future polar research.

Controlled Exposure of Healthy Young Volunteers to Ozone Causes Cardiovascular Effects

EPA Science Inventory

Background: Recent epidemiology studies have reported associations between acute ozone exposure and mortality. Such studies have previously reported associations between airborne particulate matter pollution (PM) and mortality and support for a causal relationship has come from c...

Controlled exposure of healthy young volunteers to ozone causes cardiovascular effects**

EPA Science Inventory

Background: Recent epidemiology studies have reported associations between acute ozone exposure and mortality. Such studies have previously reported associations between airborne particulate matter pollution (PM) and mortality and support for a causal relationship has come from c...

Role of nuclear progesterone receptor isoforms in uterine pathophysiology

PubMed Central

Patel, Bansari; Elguero, Sonia; Thakore, Suruchi; Dahoud, Wissam; Bedaiwy, Mohamed; Mesiano, Sam

2015-01-01

BACKGROUND Progesterone is a key hormonal regulator of the female reproductive system. It plays a major role to prepare the uterus for implantation and in the establishment and maintenance of pregnancy. Actions of progesterone on the uterine tissues (endometrium, myometrium and cervix) are mediated by the combined effects of two progesterone receptor (PR) isoforms, designated PR-A and PR-B. Both receptors function primarily as ligand-activated transcription factors. Progesterone action on the uterine tissues is qualitatively and quantitatively determined by the relative levels and transcriptional activities of PR-A and PR-B. The transcriptional activity of the PR isoforms is affected by specific transcriptional coregulators and by PR post-translational modifications that affect gene promoter targeting. In this context, appropriate temporal and cell-specific expression and function of PR-A and PR-B are critical for normal uterine function. METHODS Relevant studies describing the role of PRs in uterine physiology and pathology (endometriosis, uterine leiomyoma, endometrial cancer, cervical cancer and recurrent pregnancy loss) were comprehensively searched using PubMed, Cochrane Library, Web of Science, and Google Scholar and critically reviewed. RESULTS Progesterone, acting through PR-A and PR-B, regulates the development and function of the endometrium and induces changes in cells essential for implantation and the establishment and maintenance of pregnancy. During pregnancy, progesterone via the PRs promotes myometrial relaxation and cervical closure. Withdrawal of PR-mediated progesterone signaling triggers menstruation and parturition. PR-mediated progesterone signaling is anti-mitogenic in endometrial epithelial cells, and as such, mitigates the tropic effects of estrogen on eutopic normal endometrium, and on ectopic implants in endometriosis. Similarly, ligand-activated PRs function as tumor suppressors in endometrial cancer cells through inhibition of key cellular signaling pathways required for growth. In contrast, progesterone via PR activation appears to increase leiomyoma growth. The exact role of PRs in cervical cancer is unclear. PRs regulate implantation and therefore aberrant PR function may be implicated in recurrent pregnancy loss (RPL). PRs likely regulate key immunogenic factors involved in RPL. However, the exact role of PRs in the pathophysiology of RPL and the use of progesterone for therapeutic benefit remains uncertain. CONCLUSIONS PRs are key mediators of progesterone action in uterine tissues and are essential for normal uterine function. Aberrant PR function (due to abnormal expression and/or function) is a major cause of uterine pathophysiology. Further investigation of the underlying mechanisms of PR isoform action in the uterus is required, as this knowledge will afford the opportunity to create progestin/PR-based therapeutics to treat various uterine pathologies. PMID:25406186

De Haas van Alphen effect of PrB6 in commensurate and incommensurate phases

NASA Astrophysics Data System (ADS)

Endo, M.; Isshiki, T.; Kimura, N.; Aoki, H.; Kunii, S.

2006-05-01

We have studied the de Haas-van Alphen effect in the commensurate (C) and incommensurate (IC) phases of PrB6. It is found that the amplitudes and effective masses of the two oscillations α1 and α2 from the main Fermi surface are approximately the same in the C phase while they are considerably different in the IC phase.

Characteristics of fly ashes from full-scale coal-fired power plants and their relationship to mercury adsorption

USGS Publications Warehouse

Lu, Y.; Rostam-Abadi, M.; Chang, R.; Richardson, C.; Paradis, J.

2007-01-01

Nine fly ash samples were collected from the particulate collection devices (baghouse or electrostatic precipitator) of four full-scale pulverized coal (PC) utility boilers burning eastern bituminous coals (EB-PC ashes) and three cyclone utility boilers burning either Powder River Basin (PRB) coals or PRB blends,(PRB-CYC ashes). As-received fly ash samples were mechanically sieved to obtain six size fractions. Unburned carbon (UBC) content, mercury content, and Brunauer-Emmett-Teller (BET)-N2 surface areas of as-received fly ashes and their size fractions were measured. In addition, UBC particles were examined by scanning electron microscopy, high-resolution transmission microscopy, and thermogravimetry to obtain information on their surface morphology, structure, and oxidation reactivity. It was found that the UBC particles contained amorphous carbon, ribbon-shaped graphitic carbon, and highly ordered graphite structures. The mercury contents of the UBCs (Hg/UBC, in ppm) in raw ash samples were comparable to those of the UBC-enriched samples, indicating that mercury was mainly adsorbed on the UBC in fly ash. The UBC content decreased with a decreasing particle size range for all nine ashes. There was no correlation between the mercury and UBC contents of different size fractions of as-received ashes. The mercury content of the UBCs in each size fraction, however, generally increased with a decreasing particle size for the nine ashes. The mercury contents and surface areas of the UBCs in the PRB-CYC ashes were about 8 and 3 times higher than UBCs in the EB-PC ashes, respectively. It appeared that both the particle size and surface area of UBC could contribute to mercury capture. The particle size of the UBC in PRB-CYC ash and thus the external mass transfer was found to be the major factor impacting the mercury adsorption. Both the particle size and surface reactivity of the UBC in EB-PC ash, which generally had a lower carbon oxidation reactivity than the PRB-PC ashes, appeared to be important for the mercury adsorption. ?? 2007 American Chemical Society.

Individuals with increased inflammatory response to ozone demonstrate muted signaling of immune cell trafficking pathways

EPA Science Inventory

Background Exposure to ozone activates innate immune function and causes neutrophilic (PMN) airway inflammation that in some individuals is robustly elevated. The interplay between immunoinflammatory function and genomic signaling in those with heightened inflammatory responsive...

Vascular and Cardiac Impairments in Rats Inhaling Ozone and Diesel Exhaust Particles

EPA Science Inventory

Background -Mechanisms of cardiovascular injuries from exposure to gas and particulate air pollutants are unknown. Objective -We hypothesized that episodic exposure of rats to ozone or diesel exhaust particles (DEP) will cause differential cardiovascular impairments, which will b...

Overt and Latent Cardiac Effects of Ozone Inhalation in Rats: Evidence for Autonomic Modulation and Increased Myocardial Vulnerability

EPA Science Inventory

Background: Ozone (03) is a well-documented respiratory oxidant, but increasing epidemiologic evidence points to extra-pulmonary effects including positive associations between ambient 03 concentrations and cardiovascular morbidity/mortality. Objectives: With preliminary reports ...

Current and future background ozone simulations for Mexico using a multi-scale regional climate modeling system

NASA Astrophysics Data System (ADS)

Lamb, B. K.; Gonzalez Abraham, R.; Avise, J. C.; Chung, S. H.; Salathe, E. P.; Zhang, Y.; Guenther, A. B.; Wiedinmyer, C.; Duhl, T.; Streets, D. G.

2013-05-01

Global change will clearly have a significant impact on the environment. Among the concerns for future air quality in North America, intercontinental transport of pollution has become increasingly important. In this study, we examined the effect of projected changes in Asian emissions and emissions from lightning and wildfires to produce ozone background concentrations within Mexico and the continental US. This provides a basis for developing an understanding of North American background levels and how they may change in the future. Meteorological fields were downscaled from the results of the ECHAM5 global climate model using the Weather Research Forecast (WRF) model. Two nested domains were employed, one covering most of the Northern Hemisphere from eastern Asia to North America using 220 km grid cells (semi-hemispheric domain) and one covering the continental US and northern Mexico using 36 km grid cells. Meteorological results from WRF were used to drive the MEGAN biogenic emissions model, the SMOKE emissions processing tool, and the CMAQ chemical transport model to predict ozone concentrations for current (1995-2004) and future (2045-2054) summertime conditions. The MEGAN model was used to calculate biogenic emissions for all simulations. For the semi-hemispheric domain, year 2000 global emissions of gases (ozone precursors) from anthropogenic (outside of North America), natural, and biomass burning sources from the POET and EDGAR emission inventories were used. The global tabulation for black and organic carbon (BC and OC respectively) was obtained from Bond et al. (2004) For the future decade, the current emissions were projected to the year 2050 following the Intergovernmental Panel for Climate Change (IPCC) A1B emission scenario. Anthropogenic emissions from the US, Canada, and Mexico were omitted so that only global background concentrations, and local biogenic, wildfire, and lightning emissions were treated. In this paper, we focus on background ozone levels in Mexico due to changes in future climate, local biogenic emissions and global emissions.

Coupling of bio-PRB and enclosed in-well aeration system for remediation of nitrobenzene and aniline in groundwater.

PubMed

Liu, Na; Ding, Feng; Wang, Liu; Liu, Peng; Yu, Xiaolong; Ye, Kang

2016-05-01

A laboratory-scale bio-permeable reactive barrier (bio-PRB) was constructed and combined with enclosed in-well aeration system to treat nitrobenzene (NB) and aniline (AN) in groundwater. Batch-style experiments were first conducted to evaluate the effectiveness of NB and AN degradation, using suspension (free cells) of degrading consortium and immobilized consortium by a mixture of perlite and peat. The NB and AN were completely degraded in <3 days using immobilized consortium, while 3-5 days were required using free cells. The O2 supply efficiency of an enclosed in-well aeration system was assessed in a box filled with perlite and peat. Dissolved O2 (DO) concentrations increased to 8-12 mg L(-1) in 12 h for sampling ports within 12 cm of the aeration well. A diffusion coefficient as 33.5 cm(2) s(-1) was obtained. The DO concentration was >4 mg L(-1) when the aeration system was applied into the bio-PRB system. The NB and AN were effectively removed when the aeration system was functional in the bio-PRB. The removal efficiency decreased when the aeration system malfunctioned for 20 days, thus indicating that DO was an important factor for the degradation of NB and AN. The regain of NB and AN removal after the malfunction indicates the robustness of degradation consortium. No original organics and new formed by-products were observed in the effluent. The results indicate that NB and AN in groundwater can be completely mineralized in a bio-PRB equipped with enclosed in-well aeration system and filled with perlite and peat attached with degrading consortium.

Host range and cell cycle activation properties of polyomavirus large T-antigen mutants defective in pRB binding

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

Freund, R.; Bauer, P.H.; Benjamin, T.L.

1994-11-01

The authors have examined the growth properties of polyomavirus large T-antigen mutants that ar unable to bind pRB, the product of the retinoblastoma tumor suppressor gene. These mutants grow poorly on primary mouse cells yet grow well on NIH 3T3 and other established mouse cell lines. Preinfection of primary baby mouse kidney (BMK) epithelial cells with wild-type simian virus 40 renders these cells permissive to growth of pRB-binding polyomavirus mutants. Conversely, NIH 3T3 cells transfected by and expressing wild-type human pRB become nonpermissive. Primary fibroblasts for mouse embryos that carry a homozygous knockout of the RB gene are permissive, whilemore » those from normal littermates are nonpermissive. The host range of polyomavirus pRB-binding mutants is thus determined by expression or lack of expression of functional pRB by the host. These results demonstrate the importance of pRB binding by large T antigen for productive viral infection in primary cells. Failure of pRB-binding mutants to grow well in BMK cells correlates with their failure to induce progression from G{sub 0} or G{sub 1} through the S phase of the cell cycle. Time course studies show delayed synthesis and lower levels of accumulation of large T antigen, viral DNA, and VP1 in mutant compared with wild-type virus-infected BMK cells. These results support a model in which productive infection by polyomavirus in normal mouse cells is tightly coupled to the induction and progression of the cell cycle. 48 refs., 6 figs., 5 tabs.« less

The activities of progesterone receptor isoform A and B are differentially modulated by their ligands in a gene-selective manner.

PubMed

Leo, Joyce C L; Lin, Valerie C L

2008-01-01

It is known that progesterone receptor (PR) isoform A (PR-A) and isoform B (PR-B) may mediate different effects of progesterone. The objective of this study was to determine if the functions of PR isoforms also vary in response to different PR modulators (PRM). The effects of 7 synthetic PRM were tested in MDA-MB-231 cells engineered to express PR-A, PR-B, or both PR isoforms. The effects of progesterone were similar in cells expressing PR-A or PR-B in which it inhibited growth and induced focal adhesion. On the other hand, synthetic PRM modulated the activity of the PR isoforms differently. RU486, CDB4124, 17alpha-hydroxy CDB4124 and VA2914 exerted agonist activities on cell growth and adhesion via PR-B. Via PR-A, however, these compounds displayed agonist effect on cell growth but induced stellate morphology which was distinct from the agonist's effect. Their dual properties via PR-A were also displayed at the gene expression level: the compounds acted as agonists on cell cycle genes but exhibited antagonistic effect on cell adhesion genes. Introduction of ERalpha by adenoviral vector to these cells did not change PR-A or PR-B mediated effect of PRM radically, but it causes significant cell rounding and modified the magnitudes of the responses to PRM. The findings suggest that the activities of PR isoforms may be modulated by different PRM through gene-specific regulatory mechanisms. This raises an interesting possibility that PRM may be designed to be PR isoform and cellular pathway selective to achieve targeted therapy in breast cancer. Copyright 2007 Wiley-Liss, Inc.

Intercomparison of chemical mechanisms for air quality policy formulation and assessment under North American conditions.

PubMed

Derwent, Richard

2017-07-01

The intercomparison of seven chemical mechanisms for their suitability for air quality policy formulation and assessment is described. Box modeling techniques were employed using 44 sets of background environmental conditions covering North America to constrain the chemical development of the longer lived species. The selected mechanisms were modified to enable an unbiased assessment of the adequacy of the parameterizations of photochemical ozone production from volatile organic compound (VOC) oxidation in the presence of NO x . Photochemical ozone production rates responded differently to 30% NO x and VOC reductions with the different mechanisms, despite the striking similarities between the base-case ozone production rates. The 30% reductions in NO x and VOCs also produced changes in OH. The responses in OH to 30% reductions in NO x and VOCs appeared to be more sensitive to mechanism choice, compared with the responses in the photochemical ozone production rates. Although 30% NO x reductions generally led to decreases in OH, 30% reductions in VOCs led to increases in OH, irrespective of mechanism choice and background environmental conditions. The different mechanisms therefore gave different OH responses to NO x and VOC reductions and so would give different responses in terms of changes in the fate and behavior of air toxics, acidification and eutrophication, and fine particle formation compared with others, in response to ozone control strategies. Policymakers need to understand that there are likely to be inherent differences in the responses to ozone control strategies between different mechanisms, depending on background environmental conditions and the extents of NO x and VOC reductions under consideration. The purpose of this paper is to compare predicted ozone responses to NO x and VOC reductions with seven chemical mechanisms under North American conditions. The good agreement found between the tested mechanisms should provide some support for their application in the air quality models used for policymaking.

SRC-mediated EGF Receptor Activation Regulates Ozone-induced Interleukin 8 Expression in Human Bronchial Epithelial Cells

EPA Science Inventory

BACKGROUND: Human exposure to ozone (03) results in pulmonary function decrements and airway inflammation. The mechanisms underlying these adverse effects remain unclear. Epidermal growth factor receptor (EGFR) plays an important role in the pathogenesis of lung inflammation. ...

Inquiry Based Projects Using Student Ozone Measurements and the Status of Using Plants as Bio-Indicators

NASA Astrophysics Data System (ADS)

Ladd, I. H.; Fishman, J.; Pippin, M.; Sachs, S.; Skelly, J.; Chappelka, A.; Neufeld, H.; Burkey, K.

2006-05-01

Students around the world work cooperatively with their teachers and the scientific research community measuring local surface ozone levels using a hand-held optical scanner and ozone sensitive chemical strips. Through the GLOBE (Global Learning and Observations to Benefit the Environment) Program, students measuring local ozone levels are connected with the chemistry of the air they breathe and how human activity impacts air quality. Educational tools have been developed and correlated with the National Science and Mathematics Standards to facilitate integrating the study of surface ozone with core curriculum. Ozone air pollution has been identified as the major pollutant causing foliar injury to plants when they are exposed to concentrations of surface ozone. The inclusion of native and agricultural plants with measuring surface ozone provides an Earth system approach to understanding surface ozone. An implementation guide for investigating ozone induced foliar injury has been developed and field tested. The guide, Using Sensitive Plants as Bio-Indicators of Ozone Pollution, provides: the background information and protocol for implementing an "Ozone Garden" with native and agricultural plants; and, a unique opportunity to involve students in a project that will develop and increase their awareness of surface ozone air pollution and its impact on plants.

Airborne measurements of biomass burning products over Africa

NASA Technical Reports Server (NTRS)

Helas, Guenter; Lobert, Juergen; Goldammer, Johann; Andreae, Meinrat O.; Lacaux, J. P.; Delmas, R.

1994-01-01

Ozone has been observed in elevated concentrations by satellites over hitherto believed 'background' areas. There is meteorological evidence that these ozone 'plumes' found over the Atlantic ocean originate from biomass fires on the African continent. Therefore we have investigated ozone and assumed precursor compounds over African regions. The measurements revealed large photosmog layers in altitudes between 1.5 and 4 km. Here we will focus on some results of ozone mixing ratios obtained during the DECAFE 91/FOS experiment and estimate the relevance of biomass burning as a source by comparing the strength of this source to stratospheric input.

Amino-terminal domains of c-myc and N-myc proteins mediate binding to the retinoblastoma gene product

NASA Astrophysics Data System (ADS)

Rustgi, Anil K.; Dyson, Nicholas; Bernards, Rene

1991-08-01

THE proteins encoded by the myc gene family are involved in the control of cell proliferation and differentiation, and aberrant expression of myc proteins has been implicated in the genesis of a variety of neoplasms1. In the carboxyl terminus, myc proteins have two domains that encode a basic domain/helix-loop-helix and a leucine zipper motif, respectively. These motifs are involved both in DNA binding and in protein dimerization2-5. In addition, myc protein family members share several regions of highly conserved amino acids in their amino termini that are essential for transformation6,7. We report here that an N-terminal domain present in both the c-myc and N-myc proteins mediates binding to the retinoblastoma gene product, pRb. We show that the human papilloma virus E7 protein competes with c-myc for binding to pRb, indicating that these proteins share overlapping binding sites on pRb. Furthermore, a mutant Rb protein from a human tumour cell line that carried a 35-amino-acid deletion in its C terminus failed to bind to c-myc. Our results suggest that c-myc and pRb cooperate through direct binding to control cell proliferation.

Growth and Survival of Perchlorate-Reducing Bacteria in Media Containing Elevated Perchlorate Concentrations and UV-C Conditions

NASA Technical Reports Server (NTRS)

Bywaters, K. F.; Mckay, C. P.; Quinn, R. C.

2017-01-01

Introduction: The identification of perchlorate (ClO4(-)) on Mars has led to the possibility that complete redox couples are available for microbial metabolism in contemporary surface environments. Perchlorate-reducing bacteria (PRB) utilize ClO4(-) and chlorate (ClO3(-)) as terminal electron acceptors due to the high reduction potential. Additionally, ClO4(-) salts have been suggested as a possible source of brines on Mars and spectral evidence indicates that the hydration of ClO4(-) salts in the regolith of Martian is linked to the surface recurring slope lineae (RSL). For these reasons PRB may serve as analog organisms for possible life on Mars. However, there is very little information on the viability of PRB in aqueous environments that contain high levels of perchlorate Microorganisms on or near the surface of Mars, such as in the RSL, would potentially be exposed to high-salinity and high ultraviolet radiation environments. Under these extreme conditions, microorganisms must possess mechanisms for maintaining continued high genome fidelity. To assess possible microbial viability in contemporary Mars analog environments we are investigating the tolerance of two PRB strains in aqueous conditions under high UV-C conditions and high ClO4(-) concentrations.

Column test-based optimization of the permeable reactive barrier (PRB) technique for remediating groundwater contaminated by landfill leachates

NASA Astrophysics Data System (ADS)

Zhou, Dan; Li, Yan; Zhang, Yinbo; Zhang, Chang; Li, Xiongfei; Chen, Zhiliang; Huang, Junyi; Li, Xia; Flores, Giancarlo; Kamon, Masashi

2014-11-01

We investigated the optimum composition of permeable reactive barrier (PRB) materials for remediating groundwater heavily contaminated by landfill leachate, in column tests using various mixtures of zero-valent iron (ZVI), zeolite (Zeo) and activated carbon (AC) with 0.01-0.25, 3.0-5.0 and 0.7-1.0 mm grain sizes, respectively. The main contributors to the removal of organic/inorganic contaminants were ZVI and AC, and the optimum weight ratio of the three PRB materials for removing the contaminants and maintaining adequate hydraulic conductivity was found to be 5:1:4. Average reductions in chemical oxygen demand (COD) and contents of total nitrogen (TN), ammonium, Ni, Pb and 16 polycyclic aromatic hydrocarbons (PAHs) from test samples using this mixture were 55.8%, 70.8%, 89.2%, 70.7%, 92.7% and 94.2%, respectively. We also developed a systematic method for estimating the minimum required thickness and longevity of the PRB materials. A ≥ 309.6 cm layer with the optimum composition is needed for satisfactory longevity, defined here as meeting the Grade III criteria (the Chinese National Bureau of Standards: GB/T14848/93) for in situ treatment of the sampled groundwater for ≥ 10 years.

Early breakthrough of molybdenum and uranium in a permeable reactive barrier.

PubMed

Morrison, Stan J; Mushovic, Paul S; Niesen, Preston L

2006-03-15

A permeable reactive barrier (PRB) using zerovalent iron (ZVI) was installed at a site near Cañon City, CO, to treat molybdenum (Mo) and uranium (U) in groundwater. The PRB initially decreased Mo concentrations from about 4.8 to less than 0.1 mg/L; however, Mo concentrations in the ZVI increased to 2.0 mg/L after about 250 days and continued to increase until concentrations in the ZVI were about 4 times higherthan in the influent groundwater. Concentrations of U were reduced from 1.0 to less than 0.02 mg/L during the same period. Investigations of solid-phase samples indicate that (1) calcium carbonate, iron oxide, and sulfide minerals had precipitated in pores of the ZVI; (2) U and Mo were concentrated in the upgradient 5.1 cm of the ZVI; and (3) calcium was present throughout the ZVI accounting for up to 20.5% of the initial porosity. Results of a column test indicated that the ZVI from the PRB was still reactive for removing Mo and that removal rates were dependenton residence time and pH. The chemical evolution of the PRB is explained in four stages that present a progression from porous media flow through preferential flow and, finally, complete bypass of the ZVI.

A Madden-Julian Oscillation in Tropospheric Ozone

NASA Technical Reports Server (NTRS)

Ziemke, J. R.; Chandra, S.

2004-01-01

This is the first study to indicate a Madden-Julian Oscillation (MJO) in tropospheric ozone. Tropospheric ozone is derived using differential measurements of total column ozone and stratospheric column ozone measured from total ozone mapping spectrometer (TOMS) and microwave limb sounder (MLS) instruments. Two broad regions of significant MJO signal are identified in the tropics, one in the western Pacific and the other in the eastern Pacific. Over both regions, MJO variations in tropospheric ozone represent 5- 10 DU peak-to-peak anomalies. These variations are significant compared to mean background amounts of 20 DU or less over most of the tropical Pacific. The implications of these results are: (1) model values of TCO in the tropical Pacific region, when accounted for the MJO may be highly variable depending upon the phase of the MJO, and (2) MJO signals of this magnitude would need to be considered when investigating and interpreting particular pollution events since ozone is a precursor of the hydroxyl (OH) radical, the main oxidizing agent of pollutants in the lower atmosphere.

A Two-Timescale Response of the Southern Ocean to Ozone Depletion: Importance of the Background State

NASA Astrophysics Data System (ADS)

Seviour, W.; Waugh, D.; Gnanadesikan, A.

2016-02-01

It has been recently suggested that the response of Southern Ocean sea-ice extent to stratospheric ozone depletion is time-dependent; that the ocean surface initially cools due to enhanced northward Ekman drift caused by a poleward shift in the eddy-driven jet, and then warms after some time due to upwelling of warm waters from below the mixed layer. It is therefore possible that ozone depletion could act to favor a short-term increase in sea-ice extent. However, many uncertainties remain in understanding this mechanism, with different models showing widely differing time-scales and magnitudes of the response. Here, we analyze an ensemble of coupled model simulations with a step-function ozone perturbation. The two-timescale response is present with an approximately 30 year initial cooling period. The response is further shown to be highly dependent upon the background ocean temperature and salinity stratification, which is influenced by both natural internal variability and the isopycnal eddy mixing parameterization. It is suggested that the majority of inter-model differences in the Southern Ocean response to ozone depletion are caused by differences in stratification.

Foliar Symptoms Triggered by Ozone Stress in Irrigated Holm Oaks from the City of Madrid, Spain

PubMed Central

Guerrero, Carlos Calderón; Günthardt-Goerg, Madeleine S.; Vollenweider, Pierre

2013-01-01

Background Despite abatement programs of precursors implemented in many industrialized countries, ozone remains the principal air pollutant throughout the northern hemisphere with background concentrations increasing as a consequence of economic development in former or still emerging countries and present climate change. Some of the highest ozone concentrations are measured in regions with a Mediterranean climate but the effect on the natural vegetation is alleviated by low stomatal uptake and frequent leaf xeromorphy in response to summer drought episodes characteristic of this climate. However, there is a lack of understanding of the respective role of the foliage physiology and leaf xeromorphy on the mechanistic effects of ozone in Mediterranean species. Particularly, evidence about morphological and structural changes in evergreens in response to ozone stress is missing. Results Our study was started after observing ozone -like injury in foliage of holm oak during the assessment of air pollution mitigation by urban trees throughout the Madrid conurbation. Our objectives were to confirm the diagnosis, investigate the extent of symptoms and analyze the ecological factors contributing to ozone injury, particularly, the site water supply. Symptoms consisted of adaxial and intercostal stippling increasing with leaf age. Underlying stippling, cells in the upper mesophyll showed HR-like reactions typical of ozone stress. The surrounding cells showed further oxidative stress markers. These morphological and micromorphological markers of ozone stress were similar to those recorded in deciduous broadleaved species. However, stippling became obvious already at an AOT40 of 21 ppm•h and was primarily found at irrigated sites. Subsequent analyses showed that irrigated trees had their stomatal conductance increased and leaf life -span reduced whereas the leaf xeromorphy remained unchanged. These findings suggest a central role of water availability versus leaf xeromorphy for ozone symptom expression by cell injury in holm oak. PMID:23894424

First Reprocessing of Southern Hemisphere ADditional OZonesondes Profile Records: 3. Uncertainty in Ozone Profile and Total Column

NASA Astrophysics Data System (ADS)

Witte, Jacquelyn C.; Thompson, Anne M.; Smit, Herman G. J.; Vömel, Holger; Posny, Françoise; Stübi, Rene

2018-03-01

Reprocessed ozonesonde data from eight SHADOZ (Southern Hemisphere ADditional OZonesondes) sites have been used to derive the first analysis of uncertainty estimates for both profile and total column ozone (TCO). The ozone uncertainty is a composite of the uncertainties of the individual terms in the ozone partial pressure (PO3) equation, those being the ozone sensor current, background current, internal pump temperature, pump efficiency factors, conversion efficiency, and flow rate. Overall, PO3 uncertainties (ΔPO3) are within 15% and peak around the tropopause (15 ± 3 km) where ozone is a minimum and ΔPO3 approaches the measured signal. The uncertainty in the background and sensor currents dominates the overall ΔPO3 in the troposphere including the tropopause region, while the uncertainties in the conversion efficiency and flow rate dominate in the stratosphere. Seasonally, ΔPO3 is generally a maximum in the March-May, with the exception of SHADOZ sites in Asia, for which the highest ΔPO3 occurs in September-February. As a first approach, we calculate sonde TCO uncertainty (ΔTCO) by integrating the profile ΔPO3 and adding the ozone residual uncertainty, derived from the McPeters and Labow (2012, doi:10.1029/2011JD017006) 1σ ozone mixing ratios. Overall, ΔTCO are within ±15 Dobson units (DU), representing 5-6% of the TCO. Total Ozone Mapping Spectrometer and Ozone Monitoring Instrument (TOMS and OMI) satellite overpasses are generally within the sonde ΔTCO. However, there is a discontinuity between TOMS v8.6 (1998 to September 2004) and OMI (October 2004-2016) TCO on the order of 10 DU that accounts for the significant 16 DU overall difference observed between sonde and TOMS. By comparison, the sonde-OMI absolute difference for the eight stations is only 4 DU.

Model-based analysis of avoidance of ozone stress by stomatal closure in Siebold's beech (Fagus crenata)

PubMed Central

Hoshika, Yasutomo; Watanabe, Makoto; Inada, Naoki; Koike, Takayoshi

2013-01-01

Background and Aims Resistance of plants to ozone stress can be classified as either avoidance or tolerance. Avoidance of ozone stress may be explained by decreased stomatal conductance during ozone exposure because stomata are the principal interface for entry of ozone into plants. In this study, a coupled photosynthesis–stomatal model was modified to test whether the presence of ozone can induce avoidance of ozone stress by stomatal closure. Methods The response of Siebold's beech (Fagus crenata), a representative deciduous tree species, to ozone was studied in a free-air ozone exposure experiment in Japan. Photosynthesis and stomatal conductance were measured under ambient and elevated ozone. An optimization model of stomata involving water, CO2 and ozone flux was tested using the leaf gas exchange data. Key Results The data suggest that there are two phases in the avoidance of ozone stress via stomatal closure for Siebold's beech: (1) in early summer ozone influx is efficiently limited by a reduction in stomatal conductance, without any clear effect on photosynthetic capacity; and (2) in late summer and autumn the efficiency of ozone stress avoidance was decreased because the decrease in stomatal conductance was small and accompanied by an ozone-induced decline of photosynthetic capacity. Conclusions Ozone-induced stomatal closure in Siebold's beech during early summer reduces ozone influx and allows the maximum photosynthetic capacity to be reached, but is not sufficient in older leaves to protect the photosynthetic system. PMID:23904447

Lidar Observations of the Vertical Structure of Ozone and Aerosol during Wintertime High-Ozone Episodes Associated with Oil and Gas Exploration in the Uintah Basin

NASA Astrophysics Data System (ADS)

Senff, C. J.; Langford, A. O.; Banta, R. M.; Alvarez, R. J.; Weickmann, A.; Sandberg, S.; Marchbanks, R. D.; Brewer, A.; Hardesty, R. M.

2013-12-01

The Uintah Basin in northeast Utah has been experiencing extended periods of poor air quality in the winter months including very high levels of surface ozone. To investigate the causes of these wintertime ozone pollution episodes, two comprehensive studies were undertaken in January/February of 2012 and 2013. As part of these Uintah Basin Ozone Studies (UBOS), NOAA deployed its ground-based, scanning Tunable Optical Profiler for Aerosol and oZone (TOPAZ) lidar to document the vertical structure of ozone and aerosol backscatter from near the surface up to about 3 km above ground level (AGL). TOPAZ, along with a comprehensive set of chemistry and meteorological measurements, was situated in both years at the Horse Pool site at the northern edge of a large concentration of gas producing wells in the eastern part of the Uintah Basin. The 2012 study was characterized by unusually warm and snow-free condition and the TOPAZ lidar observed deep boundary layers (BL) and mostly well-mixed vertical ozone profiles at or slightly above tropospheric background levels. During UBOS 2013, winter weather conditions in the Uintah Basin were more typical with snow-covered ground and a persistent, shallow cold-pool layer. The TOPAZ lidar characterized with great temporal and spatial detail the evolution of multiple high-ozone episodes as well as cleanout events caused by the passage of synoptic-scale storm systems. Despite the snow cover, the TOPAZ observations show well-mixed afternoon ozone and aerosol profiles up to about 100 m AGL. After several days of pollutant buildup, BL ozone values reached 120-150 ppbv. Above the mixed layer, ozone values gradually decreased to tropospheric background values of around 50 ppbv throughout the several-hundred-meter-deep cold-pool layer and then stayed constant above that up to about 3 km AGL. During the ozone episodes, the lidar observations show no indication of either vertical or horizontal transport of high ozone levels to the surface, thus supporting the notion that ozone is locally produced in the Uintah Basin. In both winters, TOPAZ occasionally observed ozone titration as the NOx-rich plume from the nearby Bonanza power plant was advected over the Horse Pool site. In 2012, low ozone values due to titration were observed at the surface and throughout the well-mixed BL, while in 2013 low ozone values were confined to the upper part of the cold-pool layer above the BL. This suggests that power plant NOx was very likely not part of the precursor mix that led to the high surface ozone values observed in 2013.

ANTIOXIDANT SUPPLEMENTATION AND NASAL INFLAMMATORY RESPONSES AMONG YOUNG ASTHMATICS EXPOSED TO HIGH LEVELS OF OZONE

EPA Science Inventory

Background: Recent studies examining the inflammatory response in atopic asthma to ozone suggest a release of soluble mediators of inflammation factors that might be related to reactive oxygen species (ROS). Antioxidant could prove useful in subjects exposed to additional oxidati...

Evaluation of energetic particle effects on BUV data and atmospheric ozone

NASA Technical Reports Server (NTRS)

Herman, J. R.

1977-01-01

To aid investigations of energetic particle effects on the backscattered ultraviolet (BUV) instrumentation aboard Nimbus 4, solar proton events characterized as polar cap absorption events occurring in the period April 1970 to April 1976 were summarized. Energetic particle effects on total ozone above the 4 mb pressure level measured by Nimbus 4 were analyzed. Proceedings of a workshop meeting of operation aurorozone are included as background material for possible effects of bremsstrahlung on atmospheric ozone.

Surface ozone variability at Kislovodsk Observatory

NASA Technical Reports Server (NTRS)

Elansky, Nikolay F.; Makarov, Oleg V.; Senik, Irina A.

1994-01-01

The results of the surface ozone observations at the Observatory 'Kislovodsk', situated in the North Caucasus at the altitude 2070 m a.s.l., are given. The observatory is in the background conditions and the variations of the surface ozone are determined by the natural dynamic and photochemical processes. The mean value of the concentration and its seasonal variations are very near to those obtained at the high-mountain stations in Alps. The daily variations have the features, which remain stable during all warm period of the year (April-October). These features, including the minimum of the surface ozone at noon, are formed by the mountain-valley circulation. The significant variations of the surface ozone are connected with the unstationary lee waves.

Cumulus cloud venting of mixed layer ozone

NASA Technical Reports Server (NTRS)

Ching, J. K. S.; Shipley, S. T.; Browell, E. V.; Brewer, D. A.

1985-01-01

Observations are presented which substantiate the hypothesis that significant vertical exchange of ozone and aerosols occurs between the mixed layer and the free troposphere during cumulus cloud convective activity. The experiments utilized the airborne Ultra-Violet Differential Absorption Lidar (UV-DIAL) system. This system provides simultaneous range resolved ozone concentration and aerosol backscatter profiles with high spatial resolution. Evening transects were obtained in the downwind area where the air mass had been advected. Space-height analyses for the evening flight show the cloud debris as patterns of ozone typically in excess of the ambient free tropospheric background. This ozone excess was approximately the value of the concentration difference between the mixed layer and free troposphere determined from independent vertical soundings made by another aircraft in the afternoon.

SUMMARY CONCLUSIONS FOR THE PILOT IN-SITU CHROMIUM REDUCTION TEST AT RIVERBANK ARMY AMMUNITIONS PLANT

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

Ridley, M

2007-04-25

A treatability study was conducted at Riverbank Army Ammunition Plant's (RBAAP) Site 17, to evaluate the effectiveness of a permeable reactive barrier (PRB) for the treatment of hexavalent chromium (Cr{sup 6+}). The chromium contamination at Site 17 is hydrologically isolated and unsuitable for standard extraction and treatment (pump and treat). The majority of the chromium contamination at Site 17 is trapped within the fine grain sediments of a clay/slit zone (45 to 63). The PRB was established above and adjacent to the contaminated zone at Site 17 to reduce the hexavalent chromium as it leaches out of the contaminated clay/siltmore » zone separating the A zone from the A zone. Site 17 and the monitoring network are described in the In-Situ Chromium Reduction Treatability Study Work Plan (CH2MHILL, January 2004). The PRB was created by reducing naturally occurring Fe{sup 3+} to Fe{sup 2+} with the injection of a buffered sodium dithionite solution into subsurface chromium source area. The Cr{sup 6+} leaching out of the contaminated clay/silt zone and migrating through the PRB is reduced by Fe{sup 2+} to Cr{sup 3+} and immobilized (Amonette, et al., 1994). The sodium dithionite will also reduce accessible Cr{sup 6+}, however the long-term reductant is the Fe{sup 2+}. Bench scale tests (Appendix A) were conducted to assess the quantity and availability of the naturally occurring iron at Site 17, the ability of the sodium dithionite to reduce the hexavalent chromium and Fe within the sediments, and the by-products produced during the treatment. Appendix A, provides a detailed description of the laboratory treatability tests, and provides background information on the technologies considered as possible treatment options for Site 17. Following the sodium dithionite treatment, groundwater/treatment solution was extracted to remove treatment by-products (sulfate, manganese, and iron). The following sections briefly discuss the current treatment status, future recommendations for Site 17, and future recommendations for the application of sodium dithionite at additional sites. At the completion of the treatability test, none of the wells at Site 17 had detectable hexavalent chromium, but the sulfate, iron, and manganese concentrations were detected and exceeded the CA secondary drinking water standards. The extraction done after the injection of the sodium dithionite solution to remove the sulfate, manganese, and iron has to a large extent negated the effectiveness of the iron reduction. Riverbank's local groundwater is naturally high in dissolved oxygen (concentration range at Site 17: 1.8 to 6.0 mg/l) and moving this type of groundwater through the reduced zone caused oxidation of the Fe2+ within the treatment zone, followed by a new release of hexavalent chromium detected in one of the treatment wells. Additional extraction at Site 17 will continue to degrade the PRB, threatening to release additional Cr{sup 6+} into the groundwater. Sulfate and manganese only exceed the CA secondary drinking water standards in the area immediately surrounding the PRB. It is unlikely that these contaminants will threaten any water supply wells in the area. The chromium concentrations are increasing in IW-17. The current concentration is still only a third of the original concentration. It might be worth investigating some of the new zero valent iron treatments, such as nanoscale zero-valent iron (NZVI) to replace the in-situ naturally occurring iron, which may no longer be available for reduction. The NZVI has been successfully tested at NASA in Florida (O'Hara, 2006), and demonstrated no release of metals from the natural sediments. This might also be a viable option for other sites at RBAAP.« less

A new customized fetal growth standard for African American women: the PRB/NICHD Detroit Study

PubMed Central

Tarca, Adi L.; Romero, Roberto; Gudicha, Dereje W.; Erez, Offer; Hernandez-Andrade, Edgar; Yeo, Lami; Bhatti, Gaurav; Pacora, Percy; Maymon, Eli; Hassan, Sonia S.

2018-01-01

Background The assessment of fetal growth disorders requires a standard. Current nomograms for the assessment of fetal growth in African American women have been derived either from neonatal (rather than fetal) biometry data or have not been customized for maternal ethnicity, weight, height, parity, and fetal sex. Objective We sought to 1) develop a new customized fetal growth standard for African American mothers; and 2) compare such a standard to three existing standards for the classification of fetuses as small (SGA) or large (LGA) for gestational age. Study Design A retrospective cohort study included 4,183 women (4,001 African American and 182 Caucasian) from the Detroit metropolitan area who underwent ultrasound examinations between 14 and 40 weeks of gestation (the median number of scans per pregnancy was 5, interquartile range 3-7) and for whom relevant covariate data were available. Longitudinal quantile regression was used to build models defining the “normal” estimated fetal weight (EFW) centiles for gestational age in African American women, adjusted for maternal height, weight, parity, and fetal sex, and excluding pathologic factors with a significant effect on fetal weight. The resulting Perinatology Research Branch/Eunice Kennedy Shriver National Institute of Child Health and Human Development (hereinafter, PRB/NICHD) growth standard was compared to 3 other existing standards—the customized gestation-related optimal weight (GROW) standard; the Eunice Kennedy Shriver National Institute of Child Health and Human Development (hereinafter, NICHD) African American standard; and the multinational World Health Organization (WHO) standard—utilized to screen fetuses for SGA (<10th centile) or LGA (>90th centile) based on the last available ultrasound examination for each pregnancy. Results 1) First, the mean birthweight at 40 weeks was 133g higher for neonates born to Caucasian than to African American mothers and 150g higher for male than female neonates; maternal weight, height, and parity had a positive effect on birthweight.Second, analysis of longitudinal EFW revealed the following features of fetal growth: (1) all weight centiles were about 2% higher for male than for female fetuses; (2) maternal height had a positive effect on EFW, with larger fetuses being affected more (2% increase in the 95th centile of weight for each 10-cm increase in height); and (3) maternal weight and parity had a positive effect on EFW that increased with gestation and varied among the weight centiles. Third, the screen-positive rate for SGA was 7.2% for the NICHD African American standard, 12.3% for the GROW standard, 13% for the WHO standard customized by fetal sex, and 14.4% for the PRB/NICHD customized standard. For all standards, the screen-positive rate for SGA was at least two-fold higher among fetuses delivered preterm than at term.Fourth, the screen-positive rate for LGA was 8.7% for the GROW standard, 9.2% for the PRB/NICHD customized standard, 10.8% for the WHO standard customized by fetal sex, and 12.3% for the NICHD African American standard. Finally, the highest overall agreement among standards was between the GROW and PRB/NICHD customized standards (Cohen’s inter-rater agreement, kappa=0.85). Conclusions We developed a novel customized PRB/NICHD fetal growth standard from fetal data in an African American population without assuming proportionality of the effects of covariates and also without assuming that these effects are equal on all centiles of weight; we also provide an easy-to-use centile calculator. This standard classified more fetuses as being at risk for SGA compared to existing standards, especially among fetuses delivered preterm, but classified about the same number of LGA fetuses. The comparison among the four growth standards also revealed that the most important factor determining agreement among standards is whether they account for the same factors known to affect fetal growth. PMID:29422207

Inhibition of cyclin-dependent kinase activity triggers neuronal differentiation of mouse neuroblastoma cells.

PubMed

Kranenburg, O; Scharnhorst, V; Van der Eb, A J; Zantema, A

1995-10-01

Studies on the molecular mechanisms underlying neuronal differentiation are frequently performed using cell lines established from neuroblastomas. In this study we have used mouse N1E-115 neuroblastoma cells that undergo neuronal differentiation in response to DMSO. During differentiation, cyclin-dependent kinase (cdk) activities decline and phosphorylation of the retinoblastoma gene product (pRb) is lost, leading to the appearance of a pRb-containing E2F DNA-binding complex. The loss of cdk2 activity is due to a decrease in cdk2 abundance whereas loss of cdk4 activity is caused by strong association with the cdk inhibitor (CKI) p27KIP1 and concurrent loss of cdk4 phosphorylation. Moreover, neuronal differentiation can be induced by overexpression of p27KIP1 or pRb, suggesting that inhibition of cdk activity leading to loss of pRb phosphorylation, is the major determinant for neuronal differentiation.

Inhibition of cyclin-dependent kinase activity triggers neuronal differentiation of mouse neuroblastoma cells

PubMed Central

1995-01-01

Studies on the molecular mechanisms underlying neuronal differentiation are frequently performed using cell lines established from neuroblastomas. In this study we have used mouse N1E-115 neuroblastoma cells that undergo neuronal differentiation in response to DMSO. During differentiation, cyclin-dependent kinase (cdk) activities decline and phosphorylation of the retinoblastoma gene product (pRb) is lost, leading to the appearance of a pRb-containing E2F DNA-binding complex. The loss of cdk2 activity is due to a decrease in cdk2 abundance whereas loss of cdk4 activity is caused by strong association with the cdk inhibitor (CKI) p27KIP1 and concurrent loss of cdk4 phosphorylation. Moreover, neuronal differentiation can be induced by overexpression of p27KIP1 or pRb, suggesting that inhibition of cdk activity leading to loss of pRb phosphorylation, is the major determinant for neuronal differentiation. PMID:7559779

Effects of stratospheric ozone recovery on photochemistry and ozone air quality in the troposphere

NASA Astrophysics Data System (ADS)

Zhang, H.; Wu, S.; Huang, Y.; Wang, Y.

2014-04-01

There has been significant stratospheric ozone depletion since the late 1970s due to ozone-depleting substances (ODSs). With the implementation of the Montreal Protocol and its amendments and adjustments, stratospheric ozone is expected to recover towards its pre-1980 level in the coming decades. In this study, we examine the implications of stratospheric ozone recovery for the tropospheric chemistry and ozone air quality with a global chemical transport model (GEOS-Chem). With a full recovery of the stratospheric ozone, the projected increases in ozone column range from 1% over the low latitudes to more than 10% over the polar regions. The sensitivity factor of troposphere ozone photolysis rate, defined as the percentage changes in surface ozone photolysis rate for 1% increase in stratospheric ozone column, shows significant seasonal variation but is always negative with absolute value larger than one. The expected stratospheric ozone recovery is found to affect the tropospheric ozone destruction rates much more than the ozone production rates. Significant decreases in surface ozone photolysis rates due to stratospheric ozone recovery are simulated. The global average tropospheric OH decreases by 1.7%, and the global average lifetime of tropospheric ozone increases by 1.5%. The perturbations to tropospheric ozone and surface ozone show large seasonal and spatial variations. General increases in surface ozone are calculated for each season, with increases by up to 0.8 ppbv in the remote areas. Increases in ozone lifetime by up to 13% are found in the troposphere. The increased lifetimes of tropospheric ozone in response to stratospheric ozone recovery enhance the intercontinental transport of ozone and global pollution, in particular for the summertime. The global background ozone attributable to Asian emissions is calculated to increase by up to 15% or 0.3 ppbv in the Northern Hemisphere in response to the projected stratospheric ozone recovery.

Surface Ozone Background in the United States: Canadian and Mexican Pollution Influences

EPA Science Inventory

We use a global chemical transport model (GEOS-Chem) with 1° x 1° horizontal resolution to quantify the effects of anthropogenic emissions from Canada, Mexico, and outside North America on daily maximum 8-h average ozone concentrations in U.S.surface air.

Concentration Response Curve for Ozone Realted Mortality at High Concentrations for presentation at International Society for Environmental Epidemiology

EPA Science Inventory

Concentration Response Curve for Ozone related Mortality at High Concentrations Ana G. Rappold, James Crooks, Lucas M. Neas Background Rising temperatures and decreased global circulation in the upcoming decades are expected to have a detrimental impact on air quality, particular...

Understanding the Laminar Distribution of Tropospheric Ozone from Ground-Based, Airborne, Spaceborne, and Modeling Perspectives

NASA Technical Reports Server (NTRS)

Newchurch, Mike; Johnson, Matthew S.; Huang, Guanyu; Kuang, Shi; Wang, Lihua; Chance, Kelly; Liu, Xiong

2016-01-01

Laminar ozone structure is a ubiquitous feature of tropospheric-ozone distributions resulting from dynamic and chemical atmospheric processes. Understanding the characteristics of these ozone laminae and the mechanisms responsible for producing them is important to outline the transport pathways of trace gases and to quantify the impact of different sources on tropospheric background ozone. In this study, we present a new method to detect ozone laminae to understand their climatological characteristics of occurrence frequency in terms of thickness and altitude. We employ both ground-based and airborne ozone lidar measurements and other synergistic observations and modeling to investigate the sources and mechanisms such as biomass burning transport, stratospheric intrusion, lightning-generated NOx, and nocturnal low-level jets that are responsible for depleted or enhanced tropospheric ozone layers. Spaceborne (e.g., OMI (Ozone Monitoring Instrument), TROPOMI (Tropospheric Monitoring Instrument), TEMPO (Tropospheric Emissions: Monitoring of Pollution)) measurements of these laminae will observe greater horizontal extent and lower vertical resolution than balloon-borne or lidar measurements will quantify. Using integrated ground-based, airborne, and spaceborne observations in a modeling framework affords insight into how to gain knowledge of both the vertical and horizontal evolution of these ubiquitous ozone laminae.

Projections of Future Summertime Ozone over the U.S.

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

Pfister, G. G.; Walters, Stacy; Lamarque, J. F.

This study uses a regional fully coupled chemistry-transport model to assess changes in surface ozone over the summertime U.S. between present and a 2050 future time period at high spatial resolution (12 km grid spacing) under the SRES A2 climate and RCP8.5 anthropogenic pre-cursor emission scenario. The impact of predicted changes in climate and global background ozone is estimated to increase surface ozone over most of the U.S; the 5th - 95th percentile range for daily 8-hour maximum surface ozone increases from 31-79 ppbV to 30-87 ppbV between the present and future time periods. The analysis of a set ofmore » meteorological drivers suggests that these mostly will add to increasing ozone, but the set of simulations conducted does not allow to separate this effect from that through enhanced global background ozone. Statistically the most robust positive feedbacks are through increased temperature, biogenic emissions and solar radiation. Stringent emission controls can counteract these feedbacks and if considered, we estimate large reductions in surface ozone with the 5th-95th percentile reduced to 27-55 ppbV. A comparison of the high-resolution projections to global model projections shows that even though the global model is biased high in surface ozone compared to the regional model and compared to observations, both the global and the regional model predict similar changes in ozone between the present and future time periods. However, on smaller spatial scales, the regional predictions show more pronounced changes between urban and rural regimes that cannot be resolved at the coarse resolution of global model. In addition, the sign of the changes in overall ozone mixing ratios can be different between the global and the regional predictions in certain regions, such as the Western U.S. This study confirms the key role of emission control strategies in future air quality predictions and demonstrates the need for considering degradation of air quality with future climate change in emission policy making. It also illustrates the need for high resolution modeling when the objective is to address regional and local air quality or establish links to human health and society.« less

Source Attribution of Near-surface Ozone in the Western US: Improved Estimates by TF HTAP2 Multi-model Experiment and Multi-scale Chemical Data Assimilation

NASA Astrophysics Data System (ADS)

Huang, M.; Bowman, K. W.; Carmichael, G. R.; Lee, M.; Park, R.; Henze, D. K.; Chai, T.; Flemming, J.; Lin, M.; Weinheimer, A. J.; Wisthaler, A.; Jaffe, D. A.

2014-12-01

Near-surface ozone in the western US can be sensitive to transported background pollutants from the free troposphere over the eastern Pacific, as well as various local emissions sources. Accurately estimating ozone source contributions in this region has strong policy-relevant significance as the air quality standards tend to go down. Here we improve modeled contributions from local and non-local sources to western US ozone base on the HTAP2 (Task Force on Hemispheric Transport of Air Pollution) multi-model experiment, along with multi-scale chemical data assimilation. We simulate western US air quality using the STEM regional model on a 12 km horizontal resolution grid, during the NASA ARCTAS field campaign period in June 2008. STEM simulations use time-varying boundary conditions downscaled from global GEOS-Chem model simulations. Standard GEOS-Chem simulation overall underpredicted ozone at 1-5 km in the eastern Pacific, resulting in underestimated contributions from the transported background pollutants to surface ozone inland. These negative biases can be reduced by using the output from several global models that support the HTAP2 experiment, which all ran with the HTAP2 harmonized emission inventory and also calculated the contributions from east Asian anthropogenic emissions. We demonstrate that the biases in GEOS-Chem boundary conditions can be more efficiently reduced via assimilating satellite ozone profiles from the Tropospheric Emission Spectrometer (TES) instrument using the three dimensional variational (3D-Var) approach. Base upon these TES-constrained GEOS-Chem boundary conditions, we then update regional nitrogen dioxide and isoprene emissions in STEM through the four dimensional variational (4D-Var) assimilation of the Ozone Monitoring Instrument (OMI) nitrogen dioxide columns and the NASA DC-8 aircraft isoprene measurements. The 4D-Var assimilation spatially redistributed the emissions of nitrogen oxides and isoprene from various US sources, and in the meantime updated the modeled ozone and its US source contributions. Compared with available independent measurements (e.g., ozone observed on the DC-8 aircraft, and at EPA and Mt. Bachelor monitoring stations) during this period, modeled ozone fields after the multi-scale assimilation show overall improvement.

[Health impact of ozone in 13 Italian cities].

PubMed

Mitis, Francesco; Iavarone, Ivano; Martuzzi, Marco

2007-01-01

to estimate the health impact of ozone in 13 Italian cities over 200,000 inhabitants and to produce basic elements to permit the reproducibility of the study in other urban locations. the following data have been used: population data (2001), health data (2001 or from scientific literature), environmental data (2002-2004), from urban background monitoring station and concentration/response risk coefficients derived from recent metanalyses. The indicators SOMO35 and SOMO0 have been used as a proxi of the average exposure to calcolate attributable deaths (and years of life lost) and several causes of morbility for ozone concentrations over 70 microg/m3. acute mortality for all causes and for cardiovascular mortality, respiratory-related hospital admissions in elderly, asthma exacerbation in children and adults, minor restricted activity days, lower respiratory symptoms in children. over 500 (1900) deaths, the 0.6% (2.1%) of total mortality, equivalent to about 6000 (22,000) years of life lost are attributable to ozone levels over 70 microg/m3 in the 13 Italian cities under study. Larger figures, in the order of thousands, are attributable to less severe morbidity outcomes. The health impact of ozone in Italian towns is relevant in terms of acute mortality and morbidity, although less severe than PM10 impact. Background ozone levels are increasing. Abatement strategies for ozone concentrations should consider the whole summer and not only "peak" days and look at policies limiting the concentration of precursors produced by traffic sources. Relevant health benefits can be obtained also under levels proposed as guidelines in the present environmental regulations.

Kelvin waves in the tropical stratosphere observed in OMPS-LP ozone measurements

NASA Astrophysics Data System (ADS)

Randel, W. J.; Park, M.

2017-12-01

We investigate equatorial waves in the tropical stratosphere using OMPS limb profiler (LP) ozone measurements spanning 2012-2017. The OMPS-LP data show clear evidence of eastward propagating planetary-scale Kelvin waves with periods near 15-20 days, and these feature are strongly modulated by the background winds linked to the quasi-biennial oscillation (QBO). We study coherence between OMPS-LP ozone and GPS radio occultation temperature measurements, and use these analyses to evaluate data quality and variability in the tropical stratosphere.

The Anatomy of High Levels of Wintertime Photochemical Ozone Production in the Uintah Basin, Utah, 2013

NASA Astrophysics Data System (ADS)

Schnell, R. C.; Oltmans, S. J.; Johnson, B.; Petron, G.; Neely, R. R.

2013-12-01

The Uintah Basin, Utah is ~ 5,000 km2 in size with lower elevations of ~1400 m msl ringed by mountains rising to ~3,000 m. Within this basin are 6,000 gas wells that produced 10 billion m3 of natural gas and 4,000 oil wells that produced ~22 million barrels of oil in 2012. In winter, the confined geography in the basin traps effluents from these fossil fuel extraction activities into a shallow layer (a few 100 meters deep) beneath strong temperature inversions, especially when ample snow cover is present throughout the basin. The temperature inversions isolate the basin from upper level winds that allow for stagnant conditions that may last for a week or more before a frontal system may flush the basin out. The highly reflective snow provides for enhanced photolysis rates that in February are comparable to those in June. In 2013 December snowfall in the Uintah Basin persisted until early March with exceptionally elevated ozone production occurring in four distinct, 10-day periods separated by 2-3 days of near background values following frontal induced washouts of the basins. In one well studied ozone event, background ozone levels of 55 ppb in the basin were measured from the surface to the lower troposphere on January 30, 2013. By February 1, ozone concentrations from the surface to the top of the 180 m deep temperature inversion averaged 100 ppb. By February 6 ozone concentrations were 165 ppb throughout the same layer. From aircraft measurements these ozone concentrations were observed to be fairly well mixed throughout the basin although there were some notable hotspots. Clean-out of ozone and ozone precursors in the Uintah Basin was observed to occur within 4 hours or less as basin air was replaced with air coming in from the west coast and mixing to the surface.

MARs Color Imager (MARCI) Daily Global Ozone Column Mapping from the Mars Reconnaissance Orbiter (MRO): A Survey of 2006-2010 Results

NASA Astrophysics Data System (ADS)

Clancy, R. T.; Wolff, M. J.; Malin, M. C.; Cantor, B. A.

2010-12-01

MARCI UV band imaging photometry within (260nm) and outside (320nm) the Hartley ozone band absorption supports daily global mapping of Mars ozone column abundances. Key retrieval issues include accurate UV radiometric calibrations, detailed specifications of surface and atmospheric background reflectance (surface albedo, atmospheric Raleigh and dust scattering/absorption), and simultaneous cloud retrievals. The implementation of accurate radiative transfer (RT) treatments of these processes has been accomplished (Wolff et al., 2010) such that daily global mapping retrievals for Mars ozone columns have been completed for the 2006-2010 period of MARCI global imaging. Ozone retrievals are most accurate for high column abundances associated with mid-to-high latitude regions during fall, winter, and spring seasons. We present a survey of these MARCI ozone column retrievals versus season, latitude, longitude, and year.

Growth of soybean at future tropospheric ozone concentrations decreases canopy evapotranspiration and soil water depletion.

PubMed

Bernacchi, Carl J; Leakey, Andrew D B; Kimball, Bruce A; Ort, Donald R

2011-06-01

Tropospheric ozone is increasing in many agricultural regions resulting in decreased stomatal conductance and overall biomass of sensitive crop species. These physiological effects of ozone forecast changes in evapotranspiration and thus in the terrestrial hydrological cycle, particularly in intercontinental interiors. Soybean plots were fumigated with ozone to achieve concentrations above ambient levels over five growing seasons in open-air field conditions. Mean season increases in ozone concentrations ([O₃]) varied between growing seasons from 22 to 37% above background concentrations. The objective of this experiment was to examine the effects of future [O₃] on crop ecosystem energy fluxes and water use. Elevated [O₃] caused decreases in canopy evapotranspiration resulting in decreased water use by as much as 15% in high ozone years and decreased soil water removal. In addition, ozone treatment resulted in increased sensible heat flux in all years indicative of day-time increase in canopy temperature of up to 0.7 °C. Published by Elsevier Ltd.

Barriers and opportunities for passive removal of indoor ozone

NASA Astrophysics Data System (ADS)

Gall, Elliott T.; Corsi, Richard L.; Siegel, Jeffrey A.

2011-06-01

This paper presents a Monte Carlo simulation to assess passive removal materials (PRMs) that remove ozone with no additional energy input and minimal byproduct formation. Distributions for air exchange rate in a subset of homes in Houston, Texas, were taken from the literature and combined with background ozone removal rates in typical houses and previous experimentally determined ozone deposition velocities to activated carbon cloth and gypsum wallboard PRMs. The median ratio of indoor to outdoor ozone was predicted to be 0.16 for homes with no PRMs installed and ranged from 0.047 to 0.12 for homes with PRMs. Median values of ozone removal effectiveness in these homes ranged from 22% to 68% for the conditions investigated. Achieving an ozone removal effectiveness above 50% in half of the homes would require installing a large area of PRMs and providing enhanced air speed to transport pollutants to PRM surfaces. Challenges associated with achieving this removal include optimizing indoor transport and aesthetic implications of large surface areas of PRM materials.

Linking micro- and macroevolutionary perspectives to evaluate the role of Quaternary sea-level oscillations in island diversification.

PubMed

Papadopoulou, Anna; Knowles, L Lacey

2017-12-01

With shifts in island area, isolation, and cycles of island fusion-fission, the role of Quaternary sea-level oscillations as drivers of diversification is complex and not well understood. Here, we conduct parallel comparisons of population and species divergence between two island areas of equivalent size that have been affected differently by sea-level oscillations, with the aim to understand the micro- and macroevolutionary dynamics associated with sea-level change. Using genome-wide datasets for a clade of seven Amphiacusta ground cricket species endemic to the Puerto Rico Bank (PRB), we found consistently deeper interspecific divergences and higher population differentiation across the unfragmented Western PRB, in comparison to the currently fragmented Eastern PRB that has experienced extreme changes in island area and connectivity during the Quaternary. We evaluate alternative hypotheses related to the microevolutionary processes (population splitting, extinction, and merging) that regulate the frequency of completed speciation across the PRB. Our results suggest that under certain combinations of archipelago characteristics and taxon traits, the repeated changes in island area and connectivity may create an opposite effect to the hypothesized "species pump" action of oscillating sea levels. Our study highlights how a microevolutionary perspective can complement current macroecological work on the Quaternary dynamics of island biodiversity. © 2017 The Author(s). Evolution © 2017 The Society for the Study of Evolution.

Kidney allocation to liver transplant candidates with renal failure of undetermined etiology: role of percutaneous renal biopsy.

PubMed

Wadei, H M; Geiger, X J; Cortese, C; Mai, M L; Kramer, D J; Rosser, B G; Keaveny, A P; Willingham, D L; Ahsan, N; Gonwa, T A

2008-12-01

The feasibility, value and risk of percutaneous renal biopsy (PRB) in liver transplant candidates with renal failure are unknown. PRB was performed on 44 liver transplant candidates with renal failure of undetermined etiology and glomerular filtration rate (GFR) <40 mL/min/1.73 m(2) (n = 37) or on renal replacement therapy (RRT) (n = 7). Patients with >or=30% interstitial fibrosis (IF), >or=40% global glomerulosclerosis (gGS) and/or diffuse glomerulonephritis were approved for simultaneous-liver-kidney (SLK) transplantation. Prebiopsy GFR, urinary sodium indices, dependency on RRT and kidney size were comparable between 27 liver-transplant-alone (LTA) and 17 SLK candidates and did not relate to the biopsy diagnosis. The interobserver agreement for the degree of IF or gGS was moderate-to-excellent. After a mean of 78 +/- 67 days, 16 and 8 patients received LTA and SLK transplants. All five LTA recipients on RRT recovered kidney function after transplantation and serum creatinine was comparable between LTA and SLK recipients at last follow-up. Biopsy complications developed in 13, of these, five required intervention. PRB is feasible in liver transplant candidates with renal failure and provides reproducible histological information that does not relate to the pretransplant clinical data. Randomized studies are needed to determine if PRB can direct kidney allocation in this challenging group of liver transplant candidates.

The efficacy of gaseous ozone against different forms of Candida albicans

PubMed Central

Zargaran, M; Fatahinia, M; Zarei Mahmoudabadi, A

2017-01-01

Background and Purpose: Ozone is an inorganic molecule with effective antimicrobial properties. Clinical treatment of ozonated water was used for the elimination of Candida albicans, Enterococcus faecalis, endotoxins, and biofilms from root canals. In addition, its therapeutic effects for tinea pedis, ulcers, and leishmaniasis were investigated. The purpose of the present study was to evaluate the fungicidal effects of ozone on different forms of C. albicans. In addition, antifungal susceptibility profile of strains was assessed before and after exposure to ozone. Materials and Methods: Fifty strains of C. albicans were exposed to gaseous ozone at different times. Furthermore, biofilm formation and germ tube production were evaluated when yeast suspensions were exposed to ozone. In addition, antifungal susceptibility of ozone resistant colonies was investiagted as compared to controls. Results: Ozone was highly effective in killing C. albicans in yeast form and inhibition of germ tube formation during 210 and 180 s, respectively. Although with increasing exposure time biofilm production was considerably decreased, resistance to ozone was much higher among vaginal and nail isolates even after 60 min. All the strains were sensitive to fluconazole, caspofungin, and terbinafine pre- and post-ozone exposure. Resistance to amphotericin B was significantly enhanced after exposure to ozone. Conclusion: Although ozone was highly effective on the yeast form of C. albicans and it can inhibit the formation of germ tubes in C. albicans, the complete removal of biofilms did not happen even after 60 min. It seems that ozone therapy induces resistance to amphotericin B. PMID:29354778

Using Source Apportionment to Evaluate the Cross State Transport of Ozone in the Eastern United States

NASA Astrophysics Data System (ADS)

Goldberg, D. L.; Canty, T. P.; Hembeck, L.; Vinciguerra, T.; Carpenter, S. F.; Anderson, D. C.; Salawitch, R. J.; Dickerson, R. R.

2014-12-01

The amount of air pollution crossing state lines has great policy implications. Using the ozone source apportionment tool (OSAT) in the Comprehensive Air-Quality Model with Extensions (CAMx) version 6.10, we can quantify how much ozone is generated locally versus transported from upwind locations. Initial results show that up to 70% of the surface ozone in Maryland during poor air quality days in the summer of July 2011 can be attributed to pollution from outside of the state's borders. Modifications to the CB05 gas-phase chemistry mechanism, supported by literature recommendations and improve agreement with NASA's DISCOVER-AQ Maryland aircraft campaign, can further increase this percentage. Additionally, we show the role of upwind sources and background ozone has become increasingly important as local emissions of ozone precursors continue to drop, starting with the steep reductions imposed in 2002 in response to Maryland's State Implementation Plan submitted to EPA. This study suggests future efforts to control surface ozone must include a meaningful strategy for dealing with cross-state transport of ozone precursors.

Global Warming and Ozone Layer Depletion: STS Issues for Social Studies Classrooms.

ERIC Educational Resources Information Center

Rye, James A.; Strong, Donna D.; Rubba, Peter A.

2001-01-01

Explores the inclusion of science-technology-society (STS) education in social studies. Provides background information on global warming and the depletion of the ozone layer. Focuses on reasons for teaching global climate change in the social studies classroom and includes teaching suggestions. Offers a list of Web sites about global climate…

Pulmonary responses of healthy young adults exposed to 0.06 and 0.08 ppm ozone

EPA Science Inventory

Background. Previous studies have shown small but significant decreases in spirometric lung function in healthy young adults exposed to 0.08 ppm ozone. It is unclear, however, if such effects may are seen at concentrations below 0.08 ppm. Methods. A group of 30 healthy young adul...

Associations of ozone and PM2.5 concentrations with Parkinson’s disease among participants in the Agricultural Health Study

EPA Science Inventory

Background: Evidence from experimental studies suggests that exposure to air pollution may be associated with risk of Parkinson’s disease (PD). Objective: To evaluate associations of ambient ozone and fine particulate matter (PM2.5 – particulate matter with an aerodynamic diam...

75 FR 953 - Approval and Promulgation of Air Quality Implementation Plans; Maryland; 2002 Base Year Emission...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-01-07

... human health, especially children and adults who are active outdoors, and individuals with a pre... EPA's regulations. II. What Is the Background for This Action? In 1997, EPA revised the health-based... the 8-hour ozone standard based on scientific evidence demonstrating that ozone causes adverse health...

75 FR 68251 - Approval and Promulgation of Air Quality Implementation Plans; Pennsylvania; 2002 Base Year...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-05

... human health, especially children and adults who are active outdoors, and individuals with a pre... EPA's regulations. II. What is the background for this action? In 1997, EPA revised the health-based... the 8-hour ozone standard based on scientific evidence demonstrating that ozone causes adverse health...

76 FR 38334 - Approval and Promulgation of Air Quality Implementation Plans; District of Columbia, Maryland...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-30

... health, especially children and adults who are active outdoors, and individuals with a pre-existing... Order Reviews I. What is the background of this action? In 1997, EPA revised the health-based NAAQS for... ozone standard based on scientific evidence demonstrating that ozone causes adverse health effects at...

Design, installation, and performance of a multi-layered permeable reactive barrier, Los Alamos National Laboratory

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

Kaszuba, J. P.; Longmire, P. A.; Strietelmeier, E. A.

2004-01-01

A multi-layered permeable reactive barrier (PRB) has been installed in Mortandad Canyon, on the Pajarito Plateau in the north-central part of LANL, to demonstrate in-situ treatment of a suite of contaminants with dissimilar geochemical properties. The PRB will also mitigate possible vulnerabilities from downgradient contaminant movement within alluvial and deeper perched groundwater. Mortandad Canyon was selected as the location for this demonstration project because the flow of alluvial groundwater is constrained by the geology of the canyon, a large network of monitoring wells already were installed along the canyon reach, and the hydrochemistry and contaminant history of the canyon ismore » well-documented. The PRB uses a funnel-and-gate system with a series of four reactive media cells to immobilize or destroy contaminants present in alluvial groundwater, including strontium-90, plutonium-238,239,240, americium-241, perchlorate, and nitrate. The four cells, ordered by sequence of contact with the groundwater, consist of gravel-sized scoria (for colloid removal); phosphate rock containing apatite (for metals and radionuclides); pecan shells and cotton seed admixed with gravel (bio-barrier, to deplete dissolved oxygen and destroy potential RCRA organic compounds, nitrate and perchlorate); and limestone (pH buffering and anion adsorption). Design elements of the PRB are based on laboratory-scale treatability studies and on a field investigation of hydrologic, geochemical, and geotechnical parameters. The PRB was designed with the following criteria: 1-day residence time within the biobarrier, 10-year lifetime, minimization of surface water infiltration and erosion, optimization of hydraulic capture, and minimization of excavated material requiring disposal. Each layer has been equipped with monitoring wells or ports to allow sampling of groundwater and reactive media, and monitor wells are located immediately adjacent to the up- and down-gradient perimeter of the engineered structure. Groundwater sampling upgradient, within, and downgradient of the PRB took place from May through August 2003. Concentrations of strontium-90 have diminished by 80% and 40% within the central portion of the phosphate rock (apatite) and bio-barrier cells, respectively. Higher concentrations of this radionuclide occur in groundwater near the north and south perimeters of the two cells. The non-uniform distribution of strontium-90 may result from varying residence time and saturated thickness of pore water. Initial concentrations of nitrate (8-12 parts per million or ppm as nitrate) and perchlorate (0.035 ppm) have been reduced in the phosphate rock and bio-barrier cells to concentrations that are less than method detection limits (0.01 and 0.002 ppm, respectively). Initial microbial analyses suggest the presence of both dissimilatory perchlorate- and nitrate-reducing bacterial populations, along with production of acetate and propionate, and decreasing dissolved oxygen and pH. The dominant group of perchlorate reducers consists of members of the previously described Dechloromonas genus, in the beta subclass of the Proteobacteria, which together with the Dechlorosoma genus are considered to be the dominant genera in circum-neutral mesophilic environments. Groundwater flow through the multiple PRB is taking place at a very slow rate based on similar concentrations of nitrate, perchlorate, chlorate, and chlorite in the upgradient well MCO-4B and downgradient well MCO-5. Concentrations of these constituents also increase within the limestone cell. Decreased precipitation due to extreme drought is probably responsible for decreasing saturated thickness within both the alluvium and PRB, resulting in stagnant conditions. Varying distributions of ammonium, nitrate, sulfate, iron, and manganese within the phosphate rock, bio-barrier, and limestone cells also support this hypothesis.« less

Effects of organ motion on proton prostate treatments, as determined from analysis of daily CT imaging for patient positioning.

PubMed

Maeda, Yoshikazu; Sato, Yoshitaka; Shibata, Satoshi; Bou, Sayuri; Yamamoto, Kazutaka; Tamamura, Hiroyasu; Fuwa, Nobukazu; Takamatsu, Shigeyuki; Sasaki, Makoto; Tameshige, Yuji; Kume, Kyo; Minami, Hiroki; Saga, Yusuke; Saito, Makoto

2018-05-01

We quantified interfractional movements of the prostate, seminal vesicles (SVs), and rectum during computed tomography (CT) image-guided proton therapy for prostate cancer and studied the range variation in opposed lateral proton beams. We analyzed 375 sets of daily CT images acquired throughout the proton therapy treatment of ten patients. We analyzed daily movements of the prostate, SVs, and rectum by simulating three image-matching strategies: bone matching, prostate center (PC) matching, and prostate-rectum boundary (PRB) matching. In the PC matching, translational movements of the prostate center were corrected after bone matching. In the PRB matching, we performed PC matching and correction along the anterior-posterior direction to match the boundary between the prostate and the rectum's anterior region. In each strategy, we evaluated systematic errors (Σ) and random errors (σ) by measuring the daily movements of certain points on each anatomic structure. The average positional deviations in millimeter of each point were determined by the Van Herk formula of 2.5Σ + 0.7σ. Using these positional deviations, we created planning target volumes of the prostate and SVs and analyzed the daily variation in the water equivalent length (WEL) from the skin surface to the target along the lateral beam directions using the density converted from the daily CT number. Based on this analysis, we designed prostate cancer treatment planning and evaluated the dose volume histograms (DVHs) for these strategies. The SVs' daily movements showed large variations over the superior-inferior direction, as did the rectum's anterior region. The average positional deviations of the prostate in the anterior, posterior, superior, inferior, and lateral sides (mm) in bone matching, PC matching, and PRB matching were (8.9, 9.8, 7.5, 3.6, 1.6), (5.6, 6.1, 3.5, 4.5, 1.9), and (8.6, 3.2, 3.5, 4.5, 1.9) (mm), respectively. Moreover, the ones of the SV tip were similarly (22.5, 15.5, 11.0, 7.6, 6.0), (11.8, 8.4, 7.8, 5.2, 6.3), and (9.9, 7.5, 7.8, 5.2, 6.3). PRB matching showed the smallest positional deviations at all portions except for the anterior portion of the prostate and was able to markedly reduce the positional deviations at the posterior portion. The averaged WEL variations at the distal and proximal sides of planning target volumes were estimated 7-9 mm and 4-6 mm, respectively, and showed the increasing of a few millimeters in PC and PRB matching compared to bone matching. In the treatment planning simulation, the DVH values of the rectum in PRB matching were reduced compared to those obtained with other matching strategies. The positional deviations for the prostate on the posterior side and the SVs were smaller by PRB matching than the other strategies and effectively reduced the rectal dose. 3D dose calculations indicate that PRB matching with CT image guidance may do a better job relative to other positioning methods to effectively reduce the rectal complications. The WEL variation was quite large, and the appropriate margin (approx. 10 mm) must be adapted to the proton range in an initial planning to maintain the coverage of target volumes throughout entire treatment. © 2018 American Association of Physicists in Medicine.

Differentiation and injury-repair signals modulate the interaction of E2F and pRB proteins with novel target genes in keratinocytes.

PubMed

Chang, Wing Y; Andrews, Joseph; Carter, David E; Dagnino, Lina

2006-08-01

E2F transcription factors are central to epidermal morphogenesis and regeneration after injury. The precise nature of E2F target genes involved in epidermal formation and repair has yet to be determined. Identification of these genes is essential to understand how E2F proteins regulate fundamental aspects of epidermal homeostasis and transformation. We have conducted a genome-wide screen using CpG island microarray analysis to identify novel promoters bound by E2F3 and E2F5 in human keratinocytes. We further characterized several of these genes, and determined that multiple E2F and retinoblastoma (pRb) family proteins associate with them in exponentially proliferating cells. We also assessed the effect on E2F and pRb binding to those genes in response to differentiation induced by bone morphogenetic protein-6 (BMP-6), or to activation of repair mechanisms induced by transforming growth factor-beta (TGF-beta). These studies demonstrate promoter- and cytokine-specific changes in binding profiles of E2F and/or pRb family proteins. For example, E2F1, 3, 4 and p107 were recruited to the N-myc promoter in cells treated with BMP-6, whereas E2F1, 3, 4, 5, p107 and p130 were bound to this promoter in the presence of TGF-beta. Functionally, these different interactions resulted in transcriptional repression by BMP-6 and TGF-beta of the N-myc gene, via mechanisms that involved E2F binding to the promoter and association with pRb-family proteins. Thus, multiple combinations of E2F and pRb family proteins may associate with and transcriptionally regulate a given target promoter in response to differentiation and injury-repair stimuli in epidermal keratinocytes.

VANDENBERG AIR FORCE BASE, CALIF. - Outside the clean room at Vandenberg Air Force Base, Calif., the SciSat-1 spacecraft (background) has been removed from the shipping container mounting base (lower left) and placed on the handling fixture. Sci-Sat, which will undergo instrument checkout and spacecraft functional testing, weighs approximately 330 pounds and after launch will be placed in a 400-mile-high polar orbit to investigate processes that control the distribution of ozone in the upper atmosphere. The data from the satellite will provide Canadian and international scientists with improved measurements relating to global ozone processes and help policymakers assess existing environmental policy and develop protective measures for improving the health of our atmosphere, preventing further ozone depletion. The mission is designed to last two years.

NASA Image and Video Library

2003-06-26

VANDENBERG AIR FORCE BASE, CALIF. - Outside the clean room at Vandenberg Air Force Base, Calif., the SciSat-1 spacecraft (background) has been removed from the shipping container mounting base (lower left) and placed on the handling fixture. Sci-Sat, which will undergo instrument checkout and spacecraft functional testing, weighs approximately 330 pounds and after launch will be placed in a 400-mile-high polar orbit to investigate processes that control the distribution of ozone in the upper atmosphere. The data from the satellite will provide Canadian and international scientists with improved measurements relating to global ozone processes and help policymakers assess existing environmental policy and develop protective measures for improving the health of our atmosphere, preventing further ozone depletion. The mission is designed to last two years.

Increasing springtime ozone mixing ratios in the free troposphere over western North America.

PubMed

Cooper, O R; Parrish, D D; Stohl, A; Trainer, M; Nédélec, P; Thouret, V; Cammas, J P; Oltmans, S J; Johnson, B J; Tarasick, D; Leblanc, T; McDermid, I S; Jaffe, D; Gao, R; Stith, J; Ryerson, T; Aikin, K; Campos, T; Weinheimer, A; Avery, M A

2010-01-21

In the lowermost layer of the atmosphere-the troposphere-ozone is an important source of the hydroxyl radical, an oxidant that breaks down most pollutants and some greenhouse gases. High concentrations of tropospheric ozone are toxic, however, and have a detrimental effect on human health and ecosystem productivity. Moreover, tropospheric ozone itself acts as an effective greenhouse gas. Much of the present tropospheric ozone burden is a consequence of anthropogenic emissions of ozone precursors resulting in widespread increases in ozone concentrations since the late 1800s. At present, east Asia has the fastest-growing ozone precursor emissions. Much of the springtime east Asian pollution is exported eastwards towards western North America. Despite evidence that the exported Asian pollution produces ozone, no previous study has found a significant increase in free tropospheric ozone concentrations above the western USA since measurements began in the late 1970s. Here we compile springtime ozone measurements from many different platforms across western North America. We show a strong increase in springtime ozone mixing ratios during 1995-2008 and we have some additional evidence that a similar rate of increase in ozone mixing ratio has occurred since 1984. We find that the rate of increase in ozone mixing ratio is greatest when measurements are more heavily influenced by direct transport from Asia. Our result agrees with previous modelling studies, which indicate that global ozone concentrations should be increasing during the early part of the twenty-first century as a result of increasing precursor emissions, especially at northern mid-latitudes, with western North America being particularly sensitive to rising Asian emissions. We suggest that the observed increase in springtime background ozone mixing ratio may hinder the USA's compliance with its ozone air quality standard.

Increasing Springtime Ozone Mixing Ratios in the Free Troposphere Over Western North America

NASA Technical Reports Server (NTRS)

Cooper, O. R.; Parrish, D. D.; Stohl, A.; Trainer, M.; Nedelec, P.; Thouret, V.; Cammas, J. P.; Oltmans, S. J.; Johnson, B. J.; Tarasick, D.;

Degradation of indoor limonene by outdoor ozone: A cascade of secondary organic aerosols.

PubMed

Rösch, Carolin; Wissenbach, Dirk K; Franck, Ulrich; Wendisch, Manfred; Schlink, Uwe

2017-07-01

In indoor air, terpene-ozone reactions can form secondary organic aerosols (SOA) in a transient process. 'Real world' measurements conducted in a furnished room without air conditioning were modelled involving the indoor background of airborne particulate matter, outdoor ozone infiltrated by natural ventilation, repeated transient limonene evaporations, and different subsequent ventilation regimes. For the given setup, we disentangled the development of nucleated, coagulated, and condensed SOA fractions in the indoor air and calculated the time dependence of the aerosol mass fraction (AMF) by means of a process model. The AMF varied significantly between 0.3 and 5.0 and was influenced by the ozone limonene ratio and the background particles which existed prior to SOA formation. Both influencing factors determine whether nucleation or adsorption processes are preferred; condensation is strongly intensified by particulate background. The results provide evidence that SOA levels in natural indoor environments can surpass those known from chamber measurements. An indicator for the SOA forming potential of limonene was found to be limona ketone. Multiplying its concentration (in μg/m 3 ) by 450(±100) provides an estimate of the concentration of the reacted limonene. This can be used to detect a high particle formation potential due to limonene pollution, e.g. in epidemiological studies considering adverse health effects of indoor air pollutants. Copyright © 2017 Elsevier Ltd. All rights reserved.

Impact of parameterization choices on the restitution of ozone deposition over vegetation

NASA Astrophysics Data System (ADS)

Le Morvan-Quéméner, Aurélie; Coll, Isabelle; Kammer, Julien; Lamaud, Eric; Loubet, Benjamin; Personne, Erwan; Stella, Patrick

2018-04-01

Ozone is a potentially phyto-toxic air pollutant, which can cause leaf damage and drastically alter crop yields, causing serious economic losses around the world. The VULNOZ (VULNerability to OZone in Anthropised Ecosystems) project is a biology and modeling project that aims to understand how plants respond to the stress of high ozone concentrations, then use a set of models to (i) predict the impact of ozone on plant growth, (ii) represent ozone deposition fluxes to vegetation, and finally (iii) estimate the economic consequences of an increasing ozone background the future. In this work, as part of the VULNOZ project, an innovative representation of ozone deposition to vegetation was developed and implemented in the CHIMERE regional chemistry-transport model. This type of model calculates the average amount of ozone deposited on a parcel each hour, as well as the integrated amount of ozone deposited to the surface at the regional or country level. Our new approach was based on a refinement of the representation of crop types in the model and the use of empirical parameters specific to each crop category. The results obtained were compared with a conventional ozone deposition modeling approach, and evaluated against observations from several agricultural areas in France. They showed that a better representation of the distribution between stomatal and non-stomatal ozone fluxes was obtained in the empirical approach, and they allowed us to produce a new estimate of the total amount of ozone deposited on the subtypes of vegetation at the national level.

La Ninez en Puerto Rico: Resultados del Censo 2000. Un informe de KIDS COUNT/PRB sobre el Censo 2000 (Children in Puerto Rico: Results from the 2000 Census. A KIDS COUNT/PRB Report on Census 2000).

ERIC Educational Resources Information Center

Mather, Mark

This Spanish-language report provides data on children in Puerto Rico based on the 2000 U.S. Census. It compares the situation of Puerto Rico's children with that of children living in the 50 states and the District of Columbia, noting how characteristics of Puerto Rican children have changed over time. Between 1990-2000, the number of Puerto…

Railroads and shippers clash over coal dust

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

Buchsbaum, L.

2007-11-15

In an effort to reduce coal spillage from railcars, mines in the Powder River Basin (PRB) now load coal with a loaf profile but, reportedly, beginning in 2008, Burlington Northern Santa Fe (BNSF) will announce guidelines requiring all PRB coal loads to be sprayed with a chemical surfactant. If this does not fix the problem, greater measures will be taken. At the time of going to press, the details of how this would be implemented and regulated were unresolved. 1 photo.

Monitoring the decontamination of a site polluted by DNAPLs

NASA Astrophysics Data System (ADS)

Audí-Miró, C.; Espinola, R.; Torrentó, C.; Otero, N.; Rossi, A.; Palau, J.; Soler, A.

2012-04-01

The aim of this study is to monitor the decontamination of a site polluted by DNAPLs coming from an automotive industry. The contamination was caused by the poor management of the waste generated by the industrial activity, which was discharged into a seepage pit. As a result, soil contamination was produced in the seepage pit area and a plume of DNAPLs-contaminated groundwater was generated. To recover the original environmental quality, a dual action was proposed: in the first place, the removal of the source of contamination and in the second one, the treatment of the DNAPLs plume. The elimination of the source of contamination consisted on a selective excavation of the seepage pit and an offsite management of the contaminated land. To restore the groundwater quality, a passive treatment system using a permeable reactive barrier (PRB) of zero valent iron (ZVI) was implemented. In order to determine the efficiency of the remediation actions, a chemical, isotopic and hydrogeological control of the main solvents detected in groundwater (perchloroethylene -PCE-, trichloroethene -TCE- and cis-dichloroethylene -cis-DCE-) has been established. Results show a decrease in PCE concentration that has been attributed to the removal of the source more than to a degradation process. However, the presence of PCE by-products, TCE and cis-DCE, might indicate a possible PCE biotic degradation. δ13CPCE values analyzed upstream and downstream of the barrier don't show isotopic changes associated to the PRB (values are around -20‰ in all the sampling points). TCE might have experienced a natural advanced degradation process according to the high concentration of cis-DCE found prior the installation of the PRB and the isotopic enrichment in δ13CTCE in some specific areas of the plume (-19.9‰ in the source and -16‰ before the barrier). Slight isotopic changes have been observed in the water flow in a far distance after the barrier (-15.4‰). δ13Ccis-DCE experienced an enrichment upstream to downstream of the barrier (from -15.5‰ to -11.5‰) indicating that a possible abiotic degradation due to the PRB is being produced. However, an enrichment in δ13Ccis-DCE from the focus area to the barrier (from -19.9‰ to -15.5‰) was also detected, suggesting that biotic degradation of cis-DCE is occurring in the field. As a conclusion, preliminary concentration and isotopic results seem to indicate that the PRB does not intercept the whole contaminated plume. The installation of a monitoring system of multilevel piezometers of new construction around the PRB has been proposed in order to study in detail the underground sections most affected by pollution and help to define patterns of migration of DNAPLs in the subsurface, giving the possibility to improve the design of the ZVI-PRB.

NOx Control for Utility Boiler OTR Compliance

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

Hamid Farzan

Under sponsorship of the Department of Energy's National Energy Technology Laboratory (NETL), the Babcock and Wilcox Company (B and W), and Fuel Tech teamed together to investigate an integrated solution for NO{sub x} control. The system is comprised of B and W's DRB-4Z{trademark} ultra low-NO{sub x} pulverized coal (PC) burner technology and Fuel Tech's NOxOUT{reg_sign}, a urea-based selective non-catalytic reduction (SNCR) technology. Development of the low-NO{sub x} burner technology has been a focus in B and W's combustion program. The DRB-4Z{trademark} burner is B and W's newest low-NO{sub x} burner capable of achieving very low NO{sub x}. The burner ismore » designed to reduce NO{sub x} by controlled mixing of the fuel and air. Based on data from several 500 to 600 MWe boilers firing PRB coal, NOx emissions levels of 0.15 to 0.20 lb/ 106 Btu have been achieved from the DRB-4Z{trademark} burners in combination with overfire air ports. Although NOx emissions from the DRB-4Z{trademark} burner are nearing the Ozone Transport Rule (OTR) level of 0.15 lb NO{sub x}/106 Btu, the utility boiler owners can still benefit from the addition of an SNCR and/or SCR system in order to comply with the stringent NO{sub x} emission levels facing them. Large-scale testing is planned in B and W's 100-million Btu/hr Clean Environment Development Facility (CEDF) that simulates the conditions of large coal-fired utility boilers. The objective of the project is to achieve a NO{sub x} level below 0.15 lb/106 Btu (with ammonia slip of less than 5 ppm) in the CEDF using PRB coal and B and W's DRB-4Z{trademark} low-NO{sub x} pulverized coal (PC) burner in combination with dual zone overfire air ports and Fuel Tech's NO{sub x}OUT{reg_sign}. During this period B and W prepared and submitted the project management plan and hazardous substance plan to DOE. The negotiation of a subcontract for Fuel Tech has been started.« less

Factors Controlling Summertime Surface Ozone In The Western U.S

NASA Astrophysics Data System (ADS)

Gao, Mei

In this dissertation we investigate different factors controlling summertime surface ozone (O3) in the western U.S., including the impacts from increased wildfire emissions, the modulation by North American summer monsoon as well as long-range transport of O3 and its precursors from outside of North America. We first analyze the surface ozone observations from the Clean Air Status and Trend Network (CASTNet) using a global chemical transport model (GEOS-Chem) to investigate the impact of biomass burning on surface O3 in the western U.S. (WUS) mountain ranges during the June--October fire season of 2007, one of the stronger fire years in the WUS in the past decade. GEOS-Chem O3 captures the observed seasonal, synoptic and daily variations. Model daily afternoon average surface O3 concentrations at the CASTNet sites are within 2 ppb of the observations, with correlation coefficients of 0.51--0.83 and Taylor scores of 0.64--0.92. Observed maximum daily 8-hour (MAD8) surface O3 concentrations are 37--8 ppb at the sites, while the corresponding model results are higher by 6 ppb on average. Model results show July--September maximum surface O3 enhancement of ~9 ppb on average because of biomass burning. Peaks in fire-contributed surface O3 correspond broadly with high levels of potassium (K), reaffirming a strong fire influence. We find a policy relevant background (PRB) O3 of 45.6 ppb on average during July--September. Fire-contributed O3 accounts for up to 30% of the PRB O3, highest in the intense fire region (Montana, Idaho, and Wyoming) with maxima in August and September. We also examine an unexpected summertime surface O3 minimum (~30--5 ppb) in July--August 2007 observed throughout the Southwestern U.S. (SWUS) by interpreting observations of O3 and rainfall from the Clean Air Status and Trends Network (CASTNet) with a global chemical transport model. The O3 minimum reflects competing chemical and dynamic factors as well as anthropogenic and natural influences. Its reoccurrence annually in 2000--11 corresponds to the seasonal rainfall maximum during the North American summer monsoon (NASM) (negative O3 and positive rainfall anomalies at the CASTNet sites, (r = -0.5 to -0.7, p < 0.05). Relative to June 15--July 15, 2007 (pre-onset of the NASM), increased cloudiness in July 15--August 15 (post-onset) weakens photochemistry, reduces O3 production from anthropogenic emissions, thereby depresses O3 throughout the lower troposphere and at the surface (-5 ppb at Chiricahua, AZ and -3 ppb on average across the SWUS). The resulting changes are largest at rainfall maxima, particularly in the core of the Great Plains low-level jet. Enhanced lightning NOx emissions post-onset augments O3 production in the middle troposphere followed by downward mixing in convective downdrafts, thereby increases O3 significantly throughout the tropospheric column and non-negligibly at the surface (+2 ppb at Chiricahua and +1 ppb averaged over the SWUS). The resulting DeltaO 3 changes is largest (+8 ppb) in the middle troposphere in the anti-cyclonic circulation associated with the reoccurring summertime high over the Southern U.S. Weaker photochemistry post-onset dominates the overall DeltaO 3 change near the surface, while enhanced lightning dominates in much of the free troposphere. Additionally, we find that transport leads to a net export of O3 throughout the tropospheric column and the influence from stratospheric intrusion is vanishingly small. These competing effects suppress O3 in the lower troposphere (DeltaO3 change up to -5 ppb) while enhance O3 at higher altitudes (DeltaO 3 change up to +7 ppb) across the SWUS during the monsoon. Better understanding of these effects is critical to estimate present and predict future background O3 in the U.S. Southwest as the NASM changes under a changing climate. Lastly we use the GEOS-Chem 3-D global tropospheric chemical transport model and its adjoint to quantify the source contributions to O3 pollution observed at Mt. Bachelor Observatory (MBO) during the summer of 2008. We found that MBO experienced distinct O3 pollution episodes from Siberia wildfire emissions. We also used the adjoint of GEOS-Chem to show the model O3 at MBO is largely sensitive to NOx emissions from biomass burning sources in Siberia and northern California, lightning sources over southwestern U.S. and Mexico, and anthropogenic sources in western U.S. and eastern Asia. For the CO emissions, the largest O 3 sensitivity is to the biomass burning sources in northern California and Siberia. The peak sensitivity to biomass burning CO emissions is comparable to the peak O3 sensitivity to anthropogenic NOx emissions. (Abstract shortened by UMI.).

Evaluating ozone air pollution effects on pines in the western United States

Treesearch

Paul R. Miller; Kenneth W. Stolte; Daniel M. Duriscoe; John Pronos

1996-01-01

Historical and technical background is provided about ozone air pollution effects on ponderosa (Pinus ponderosa Dougl. ex Laws) and Jeffrey (P. jeffreyi Grev. and Balf.) pines in forests of the western United States. The principal aim is to document the development of field survey methods to be applied to assessment of chronic...

Carbon dioxide challenge enhances the sensitivity of whole body plethysmography (WBP) measurements of lung growth and ozone-induced changes in juvenile Long-Evans rats.

EPA Science Inventory

Background. Risk factors associated with development of childhood disorders such as asthma and obesity include prematurity and intrauterine growth restriction. We recently demonstrated that exposure of Long Evans rats in early pregnancy to the air pollutant, ozone, resulted in re...

78 FR 36716 - Approval and Promulgation of Air Quality Implementation Plans; Pennsylvania; Philadelphia County...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-19

... or otherwise protected through www.regulations.gov or email. The www.regulations.gov Web site is an.... Although listed in the index, some information is not publicly available, i.e., CBI or other information... Philadelphia County addressing the requirements of RACT under the 1997 8-hour ozone NAAQS. I. Background Ozone...

An exploratory analysis of the relationship between ambient ozone and particulate matter concentrations during early pregnancy and selected birth defects in Texas

EPA Science Inventory

Background: Associations between ozone (O3) and fine particulate matter (PM2.5) concentrations and birth outcomes have been previously demonstrated. We perform an exploratory analysis of O3 and PM2.5 concentrations during early pregnancy and multiple types of birth defects. Met...

Skin Tumors Rb(eing) Uncovered

PubMed Central

Costa, Clotilde; Paramio, Jesús M.; Santos, Mirentxu

2013-01-01

The Rb1 gene was the first bona fide tumor suppressor identified and cloned more than 25 years ago. Since then, a plethora of studies have revealed the functions of pRb and the existence of a sophisticated and strictly regulated pathway that modulates such functional roles. An emerging paradox affecting Rb1 in cancer connects the relatively low number of mutations affecting Rb1 gene in specific human tumors, compared with the widely functional inactivation of pRb in most, if not in all, human cancers. The existence of a retinoblastoma family of proteins pRb, p107, and p130 and their potential unique and overlapping functions as master regulators of cell cycle progression and transcriptional modulation by similar processes, may provide potential clues to explain such conundrum. Here, we will review the development of different genetically engineered mouse models, in particular those affecting stratified epithelia, and how they have offered new avenues to understand the roles of the Rb family members and their targets in the context of tumor development and progression. PMID:24381932

Understanding Differences in Upper Stratospheric Ozone Response to Changes in Chlorine and Temperature as Computed Using CCMVal Models

NASA Technical Reports Server (NTRS)

Douglass, A. R.; Stolarski, R. S.; Strahan, S. E.; Oman, L. D.

2012-01-01

Projections of future ozone levels are made using models that couple a general circulation model with a representation of atmospheric photochemical processes, allowing interactions among photochemical processes, radiation, and dynamics. Such models are known as chemistry and climate models (CCMs). Although developed from common principles and subject to the same boundary conditions, simulated ozone time series vary for projections of changes in ozone depleting substances (ODSs) and greenhouse gases. In the upper stratosphere photochemical processes control ozone level, and ozone increases as ODSs decrease and temperature decreases due to greenhouse gas increase. Simulations agree broadly but there are quantitative differences in the sensitivity of ozone to chlorine and to temperature. We obtain insight into these differences in sensitivity by examining the relationship between the upper stratosphere annual cycle of ozone and temperature as produced by a suite of models. All simulations conform to expectation in that ozone is less sensitive to temperature when chlorine levels are highest because chlorine catalyzed loss is nearly independent of temperature. Differences in sensitivity are traced to differences in simulated temperature, ozone and reactive nitrogen when chlorine levels are close to background. This work shows that differences in the importance of specific processes underlie differences in simulated sensitivity of ozone to composition change. This suggests a) the multi-model mean is not a best estimate of the sensitivity of upper ozone to changes in ODSs and temperature; b) the spread of values is not an appropriate measure of uncertainty.

Evaluation of Intercontinental Transport of Ozone Using Full-tagged, Tagged-N and Sensitivity Methods

NASA Astrophysics Data System (ADS)

Guo, Y.; Liu, J.; Mauzerall, D. L.; Emmons, L. K.; Horowitz, L. W.; Fan, S.; Li, X.; Tao, S.

2014-12-01

Long-range transport of ozone is of great concern, yet the source-receptor relationships derived previously depend strongly on the source attribution techniques used. Here we describe a new tagged ozone mechanism (full-tagged), the design of which seeks to take into account the combined effects of emissions of ozone precursors, CO, NOx and VOCs, from a particular source, while keeping the current state of chemical equilibrium unchanged. We label emissions from the target source (A) and background (B). When two species from A and B sources react with each other, half of the resulting products are labeled A, and half B. Thus the impact of a given source on downwind regions is recorded through tagged chemistry. We then incorporate this mechanism into the Model for Ozone and Related chemical Tracers (MOZART-4) to examine the impact of anthropogenic emissions within North America, Europe, East Asia and South Asia on ground-level ozone downwind of source regions during 1999-2000. We compare our results with two previously used methods -- the sensitivity and tagged-N approaches. The ozone attributed to a given source by the full-tagged method is more widely distributed spatially, but has weaker seasonal variability than that estimated by the other methods. On a seasonal basis, for most source/receptor pairs, the full-tagged method estimates the largest amount of tagged ozone, followed by the sensitivity and tagged-N methods. In terms of trans-Pacific influence of ozone pollution, the full-tagged method estimates the strongest impact of East Asian (EA) emissions on the western U.S. (WUS) in MAM and JJA (~3 ppbv), which is substantially different in magnitude and seasonality from tagged-N and sensitivity studies. This difference results from the full-tagged method accounting for the maintenance of peroxy radicals (e.g., CH3O2, CH3CO3, and HO2), in addition to NOy, as effective reservoirs of EA source impact across the Pacific, allowing for a significant contribution to ozone formation over WUS (particularly in summer). Thus, the full-tagged method, with its clear discrimination of source and background contributions on a per-reaction basis, provides unique insights into the critical role of VOCs (and additional reactive nitrogen species) in determining the nonlinear inter-continental influence of ozone pollution.

A regional modelling study of the high ozone episode of June 2001 in southern Ontario

NASA Astrophysics Data System (ADS)

Brulfert, G.; Galvez, O.; Yang, F.; Sloan, J. J.

High ozone levels were observed in southern Ontario in the summer of 2001, particularly in June, when the observed maximum was 137 ppb at Long Point. Development of effective ozone abatement strategies to prevent such episodes requires acknowledge of the chemistry in the appropriate source regions. Comprehensive high-resolution Eulerian chemical transport models, when used with accurate emissions data and meteorology, can elucidate the atmospheric chemical and physical processes responsible for episodes like these. In this work, the MM5 /SMOKE/CMAQ regional air quality modelling system was used to investigate the chemistry involved in ozone formation during the episode in question and also more generally in the target domain. Some of the important simulations were further developed using Taylor diagrams to explore the ozone background and understand the sensitivity of ozone to NOX and VOC concentrations. Results from an arbitrary reduction of road traffic are discussed, based on NOX and VOC species in the traffic emission inventory. The ozone production rate was extracted from the model and mapped for June 2001 to assist in the identification of the source regions contributing to the ozone episode.

Atopic asthmatic subjects but not atopic subjects without ...

EPA Pesticide Factsheets

BACKGROUND: Asthma is a known risk factor for acute ozone-associated respiratory disease. Ozone causes an immediate decrease in lung function and increased airway inflammation. The role of atopy and asthma in modulation of ozone-induced inflammation has not been determined. OBJECTIVE: We sought to determine whether atopic status modulates ozone response phenotypes in human subjects. METHODS: Fifty volunteers (25 healthy volunteers, 14 atopic nonasthmatic subjects, and 11 atopic asthmatic subjects not requiring maintenance therapy) underwent a 0.4-ppm ozone exposure protocol. Ozone response was determined based on changes in lung function and induced sputum composition, including airway inflammatory cell concentration, cell-surface markers, and cytokine and hyaluronic acid concentrations. RESULTS: All cohorts experienced similar decreases in lung function after ozone. Atopic and atopic asthmatic subjects had increased sputum neutrophil numbers and IL-8 levels after ozone exposure; values did not significantly change in healthy volunteers. After ozone exposure, atopic asthmatic subjects had significantly increased sputum IL-6 and IL-1beta levels and airway macrophage Toll-like receptor 4, Fc(epsilon)RI, and CD23 expression; values in healthy volunteers and atopic nonasthmatic subjects showed no significant change. Atopic asthmatic subjects had significantly decreased IL-10 levels at baseline compared with healthy volunteers; IL-10 levels did not significa

Ultraviolet-ozone treatment reduces levels of disease-associated prion protein and prion infectivity

USGS Publications Warehouse

Johnson, C.J.; Gilbert, P.; McKenzie, D.; Pedersen, J.A.; Aiken, Judd M.

2009-01-01

Background. Transmissible spongiform encephalopathies (TSEs) are a group of fatal neurodegenerative diseases caused by novel infectious agents referred to as prions. Prions appear to be composed primarily, if not exclusively, of a misfolded isoform of the cellular prion protein. TSE infectivity is remarkably stable and can resist many aggressive decontamination procedures, increasing human, livestock and wildlife exposure to TSEs. Findings. We tested the hypothesis that UV-ozone treatment reduces levels of the pathogenic prion protein and inactivates the infectious agent. We found that UV-ozone treatment decreased the carbon and prion protein content in infected brain homogenate to levels undetectable by dry-ashing carbon analysis or immunoblotting, respectively. After 8 weeks of ashing, UV-ozone treatment reduced the infectious titer of treated material by a factor of at least 105. A small amount of infectivity, however, persisted despite UV-ozone treatment. When bound to either montmorillonite clay or quartz surfaces, PrPTSE was still susceptible to degradation by UV-ozone. Conclusion. Our findings strongly suggest that UV-ozone treatment can degrade pathogenic prion protein and inactivate prions, even when the agent is associated with surfaces. Using larger UV-ozone doses or combining UV-ozone treatment with other decontaminant methods may allow the sterilization of TSE-contaminated materials. ?? 2009 Aiken et al; licensee BioMed Central Ltd.

Health-Related Benefits of Attaining the 8-Hr Ozone Standard

PubMed Central

Hubbell, Bryan J.; Hallberg, Aaron; McCubbin, Donald R.; Post, Ellen

2005-01-01

During the 2000–2002 time period, between 36 and 56% of ozone monitors each year in the United States failed to meet the current ozone standard of 80 ppb for the fourth highest maximum 8-hr ozone concentration. We estimated the health benefits of attaining the ozone standard at these monitors using the U.S. Environmental Protection Agency’s Environmental Benefits Mapping and Analysis Program. We used health impact functions based on published epidemiologic studies, and valuation functions derived from the economics literature. The estimated health benefits for 2000 and 2001 are similar in magnitude, whereas the results for 2002 are roughly twice that of each of the prior 2 years. The simple average of health impacts across the 3 years includes reductions of 800 premature deaths, 4,500 hospital and emergency department admissions, 900,000 school absences, and > 1 million minor restricted activity days. The simple average of benefits (including premature mortality) across the 3 years is $5.7 billion [90% confidence interval (CI), 0.6–15.0] for the quadratic rollback simulation method and $4.9 billion (90% CI, 0.5–14.0) for the proportional rollback simulation method. Results are sensitive to the form of the standard and to assumptions about background ozone levels. If the form of the standard is based on the first highest maximum 8-hr concentration, impacts are increased by a factor of 2–3. Increasing the assumed hourly background from zero to 40 ppb reduced impacts by 30 and 60% for the proportional and quadratic attainment simulation methods, respectively. PMID:15626651

Ozone budget over the Amazon - Regional effects from biomass-burning emissions

NASA Technical Reports Server (NTRS)

Richardson, Jennifer L.; Fishman, Jack; Gregory, Gerald L.

1991-01-01

Data from the NASA dry-season Amazon boundary layer experiment (ABLE2A) is used with a 1D tropospheric photochemical model to analyze the atmospheric chemistry in the region and determine the impact of the long-range transport of biomass-burning emissions. Inputs of surface sources and the deposition of various species measured during ABLE2A are employed to simulate the background atmosphere, and haze characteristics are introduced for a 12-hr simulation. The in situ ozone production rate doubles during the period of haze when hydrocarbons are present. The model predicts that the production of ozone is enhanced during the dry season, and that increased ozone during the southern tropical burning season is related to the regional transport of haze.

Biomarkers of Dose and Effect of inhaled ozone in resting versus exercising human subjects: comparison with resting rats

EPA Science Inventory

Background: Human controlled exposure studies have generally focused on subjects exposed to ozone (O3) while exercising while exposures in rats have been done at rest. We exposed resting subjects to labeled O3 (18O3, 0.4 ppm, for 2 hr) and compared O3 dose and effects with our...

Impact of supersonic and subsonic aircraft on ozone: Including heterogeneous chemical reaction mechanisms

NASA Technical Reports Server (NTRS)

Kinnison, Douglas E.; Wuebbles, Donald J.

1994-01-01

Preliminary calculations suggest that heterogeneous reactions are important in calculating the impact on ozone from emissions of trace gases from aircraft fleets. In this study, three heterogeneous chemical processes that occur on background sulfuric acid aerosols are included and their effects on O3, NO(x), Cl(x), HCl, N2O5, ClONO2 are calculated.

Key drivers of ozone change and its radiative forcing over the 21st century

NASA Astrophysics Data System (ADS)

Iglesias-Suarez, Fernando; Kinnison, Douglas E.; Rap, Alexandru; Maycock, Amanda C.; Wild, Oliver; Young, Paul J.

2018-05-01

Over the 21st century changes in both tropospheric and stratospheric ozone are likely to have important consequences for the Earth's radiative balance. In this study, we investigate the radiative forcing from future ozone changes using the Community Earth System Model (CESM1), with the Whole Atmosphere Community Climate Model (WACCM), and including fully coupled radiation and chemistry schemes. Using year 2100 conditions from the Representative Concentration Pathway 8.5 (RCP8.5) scenario, we quantify the individual contributions to ozone radiative forcing of (1) climate change, (2) reduced concentrations of ozone depleting substances (ODSs), and (3) methane increases. We calculate future ozone radiative forcings and their standard error (SE; associated with inter-annual variability of ozone) relative to year 2000 of (1) 33 ± 104 m Wm-2, (2) 163 ± 109 m Wm-2, and (3) 238 ± 113 m Wm-2 due to climate change, ODSs, and methane, respectively. Our best estimate of net ozone forcing in this set of simulations is 430 ± 130 m Wm-2 relative to year 2000 and 760 ± 230 m Wm-2 relative to year 1750, with the 95 % confidence interval given by ±30 %. We find that the overall long-term tropospheric ozone forcing from methane chemistry-climate feedbacks related to OH and methane lifetime is relatively small (46 m Wm-2). Ozone radiative forcing associated with climate change and stratospheric ozone recovery are robust with regard to background climate conditions, even though the ozone response is sensitive to both changes in atmospheric composition and climate. Changes in stratospheric-produced ozone account for ˜ 50 % of the overall radiative forcing for the 2000-2100 period in this set of simulations, highlighting the key role of the stratosphere in determining future ozone radiative forcing.

Cell Cycle Dependent Regulation of Human Progesterone Receptor in Breast Cancer

DTIC Science & Technology

2004-10-01

wt PR or S400A PR (0.01-1.0 [tg each), CDK2 (ljig), and PRE-2x-TATA-luc reporter plasmid (lig) along with Renilla plasmid (10ng) as a control for...8 hours prior to treatment. Cells were collected following treatment with 10 nM R5020 or ETOH vehicle control for 18 hrs. Luciferase and renilla ...reporter, a renilla reporter construct as a transfection control, either wt PR-B or S400A mutant PR-B, and control parental vector or a vector encoding an

Exploring the roles of temperature and NOx on ozone production in the Sacramento urban plume

NASA Astrophysics Data System (ADS)

Lafranchi, B. W.; Cohen, R. C.

2009-12-01

We investigate the role of temperature and NOx (NOx = NO+NO2) on ozone (O3) production in the Sacramento urban plume over a stretch of seven years (2001-2007) using data collected at UC Blodgett Forest Research Station (a forested site in the Sierra Nevadas about 80 km downwind of Sacramento, CA) and at a series of California Air Resources Board (CARB) sites along the Sacramento-Blodgett transect. The consistent daytime wind patterns between the Central Valley of California and the foothills of the Sierra Nevada mountains permits the assumption of plume transport from downtown Sacramento, over the CARB monitoring sites in the eastern suburbs, and past the Blodgett Forest research site. While NOx emissions are limited primarily to the urban and suburban regions of the transect, biogenic volatile organic compound (VOC) emissions are significant throughout the transect, thus there is a fast transition from VOC-limited to NOx-limited as the plume travels away from the urban center, and we have the opportunity to analyze the differences in ozone production across these two chemical regimes. For this analysis, the Sacramento-Blodgett transect is separated into three segments: urban, suburban, and rural, defined by the locations of selected monitoring sites. Ozone concentrations across each segment are controlled by chemical production (Pchem) and loss (Lchem), deposition to surfaces (Ldep), and mixing with background air (Lmix). At an assumed deposition rate, mixing rate, and background O3 concentration, the net chemical flux of ozone (Pchem - Lchem) can be inferred from differences in ozone concentrations between adjacent monitoring sites. We show that ozone production rates, in general, increase with temperature. We also show that decreases in NOx emissions over the period from 2001-2007 have been effective at reducing ozone production at all points along the transect, but only on days where temperatures are highest. At low temperatures, this decrease is less apparent, and in the urban transect, ozone production is observed to increase as NOx concentrations decrease. This is attributed to the high NOx/VOC ratio that results from reduced biogenic emissions and strong local inputs of NOx, thus driving the chemical environment into a NOx-saturated regime. From these results, we give predictions of future ozone exceedences for various emissions and climate scenarios.

Baicalein induces G1 arrest in oral cancer cells by enhancing the degradation of cyclin D1 and activating AhR to decrease Rb phosphorylation

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

Cheng, Ya-Hsin, E-mail: yhcheng@mail.cmu.edu.tw; Li, Lih-Ann; Lin, Pinpin

Baicalein is a flavonoid, known to have anti-inflammatory and anti-cancer effects. As an aryl hydrocarbon receptor (AhR) ligand, baicalein at high concentrations blocks AhR-mediated dioxin toxicity. Because AhR had been reported to play a role in regulating the cell cycle, we suspected that the anti-cancer effect of baicalein is associated with AhR. This study investigated the molecular mechanism involved in the anti-cancer effect of baicalein in oral cancer cells HSC-3, including whether such effect would be AhR-mediated. Results revealed that baicalein inhibited cell proliferation and increased AhR activity in a dose-dependent manner. Cell cycle was arrested at the G1 phasemore » and the expression of CDK4, cyclin D1, and phosphorylated retinoblastoma (pRb) was decreased. When the AhR was suppressed by siRNA, the reduction of pRb was partially reversed, accompanied by a decrease of cell population at G1 phase and an increase at S phase, while the reduction of cyclin D1 and CDK4 did not change. This finding suggests that the baicalein activation of AhR is indeed associated with the reduction of pRb, but is independent of the reduction of cyclin D1 and CDK4. When cells were pre-treated with LiCl, the inhibitor of GSK-3β, the decrease of cyclin D1 was blocked and the reduction of pRb was recovered. The data indicates that in HSC-3 the reduction of pRb is both mediated by baicalein through activation of AhR and facilitation of cyclin D1 degradation, which causes cell cycle arrest at the G1 phase, and results in the inhibition of cell proliferation. -- Highlights: ► Baicalein causes the G1 phase arrest by decreasing Rb phosphorylation. ► Baicalein modulates AhR-mediated cell proliferation. ► Both AhR activation and cyclin D1 degradation results in hypophosphorylation of Rb. ► Baicalein facilitates cyclin D1 degradation by signalling the GSK-3β pathway.« less

Effect of water management, tillage options and phosphorus status on arsenic uptake in rice.

PubMed

Talukder, A S M H M; Meisner, C A; Sarkar, M A R; Islam, M S

2011-05-01

High arsenic (As) concentrations in soil may lead to elevated concentrations of arsenic in agricultural products. Field experiments were conducted to examine the effects of water management (WM) and Phosphorus (P) rates on As uptake, rice growth, yield and yield attributes of winter (boro) and monsoon (aman) rice in an As contaminated soil-water at Gobindagonj, Gaibandha, Bangladesh in 2004 and 2005. Significantly, the highest average grain yields (6.88±0.07 t ha(-1) in boro 6.38±0.06 t ha(-1) in aman) were recorded in permanent raised bed (PRB; aerobic WM: Eh=+360 mV) plus 100% P amendment. There was a 12% yield increase over conventional till on flat (CTF; anaerobic WM: Eh=-56 mV) at the same P level. In boro, the As content in grain and As content in straw were about 3 and 6 times higher in CTF compared to PRB, respectively. The highest total As content (0.646±0.01 ppm in grain and 10.93±0.19 ppm in straw) was recorded under CTF, and the lowest total As content (0.247±0.01 and 1.554±0.09 ppm in grain and straw, respectively) was recorded under PRB (aerobic WM). The results suggest that grain and straw As are closely associated in boro rice. The furrow irrigation approach of the PRB treatments consistently reduced irrigation input by 29-31% for boro and 27-30% for aman rice relative to CTF treatments in 2004 and 2005, respectively, thus reducing the amount of As added to the soil from the As-contaminated irrigation water. Yearly, 30% less As was deposited to the soil compared to CTF system through irrigation water during boro season. High As concentrations in grain and straw in rice grown using CTF in the farmers' field, and the fact that using PRB reduced grain As concentrations to value less than half of the proposed food hygiene standard. Copyright © 2010 Elsevier Inc. All rights reserved.

The changing oxidizing environment in London - trends in ozone precursors and their contribution to ozone production

NASA Astrophysics Data System (ADS)

von Schneidemesser, E.; Vieno, M.; Monks, P. S.

2014-01-01

Ground-level ozone is recognized to be a threat to human health (WHO, 2003), have a deleterious impact on vegetation (Fowler et al., 2009), is also an important greenhouse gas (IPCC, 2007) and key to the oxidative ability of the atmosphere (Monks et al., 2009). Owing to its harmful effect on health, much policy and mitigation effort has been put into reducing its precursors - the nitrogen oxides (NOx) and non-methane volatile organic compounds (NMVOCs). The non-linear chemistry of tropospheric ozone formation, dependent mainly on NOx and NMVOC concentrations in the atmosphere, makes controlling tropospheric ozone complex. Furthermore, the concentration of ozone at any given point is a complex superimposition of in-situ produced or destroyed ozone and transported ozone on the regional and hemispheric-scale. In order to effectively address ozone, a more detailed understanding of its origins is needed. Here we show that roughly half (5 μg m-3) of the observed increase in urban (London) ozone (10 μg m-3) in the UK from 1998 to 2008 is owing to factors of local origin, in particular, the change in NO : NO2 ratio, NMVOC : NOx balance, NMVOC speciation, and emission reductions (including NOx titration). In areas with previously higher large concentrations of nitrogen oxides, ozone that was previously suppressed by high concentrations of NO has now been "unmasked", as in London and other urban areas of the UK. The remaining half (approximately 5 μg m-3) of the observed ozone increase is attributed to non-local factors such as long-term transport of ozone, changes in background ozone, and meteorological variability. These results show that a two-pronged approach, local action and regional-to-hemispheric cooperation, is needed to reduce ozone and thereby population exposure, which is especially important for urban ozone.

Progranulin Deficiency Reduces CDK4/6/pRb Activation and Survival of Human Neuroblastoma SH-SY5Y Cells.

PubMed

de la Encarnación, Ana; Alquézar, Carolina; Esteras, Noemí; Martín-Requero, Ángeles

2015-12-01

Null mutations in GRN are associated with frontotemporal lobar degeneration with TDP-43 inclusions (FTLD-TDP). However, the influence of progranulin (PGRN) deficiency in neurodegeneration is largely unknown. In neuroblastoma cells, silencing of GRN gene causes significantly reduced cell survival after serum withdrawal. The following observations suggest that alterations of the CDK4/6/retinoblastoma protein (pRb) pathway, secondary to changes in PI3K/Akt and ERK1/2 activation induced by PGRN deficiency, are involved in the control of serum deprivation-induced apoptosis: (i) inhibiting CDK4/6 levels or their associated kinase activity by sodium butyrate or PD332991 sensitized control SH-SY5Y cells to serum deprivation-induced apoptosis without affecting survival of PGRN-deficient cells; (ii) CDK4/6/pRb seems to be downstream of the PI3K/Akt and ERK1/2 signaling pathways since their specific inhibitors, LY294002 and PD98059, were able to decrease CDK6-associated kinase activity and induce death of control SH-SY5Y cells; (iii) PGRN-deficient cells show reduced stimulation of PI3K/Akt, ERK1/2, and CDK4/6 activities compared with control cells in the absence of serum; and (iv) supplementation of recombinant human PGRN was able to rescue survival of PGRN-deficient cells. These observations highlight the important role of PGRN-mediated stimulation of the PI3K/Akt-ERK1/2/CDK4/6/pRb pathway in determining the cell fate survival/death under serum deprivation.

Inflammatory Stimuli Increase Progesterone Receptor-A Stability and Transrepressive Activity in Myometrial Cells

PubMed Central

Peters, Gregory A.; Yi, Lijuan; Skomorovska-Prokvolit, Yelenna; Patel, Bansari; Amini, Peyvand; Tan, Huiqing

2017-01-01

The steroid hormone progesterone acting via the nuclear progesterone receptor (PR) isoforms, progesterone receptor A (PR-A) and progesterone receptor B (PR-B), is essential for the maintenance of uterine quiescence during pregnancy. Inhibition of PR signaling augments uterine contractility and induces labor. Human parturition is thought to be triggered by modulation of PR signaling in myometrial cells to induce a functional progesterone withdrawal. One mechanism for functional progesterone withdrawal is increased abundance of PR-A, which decreases progesterone responsiveness by inhibiting the transcriptional activity of PR-B. Human parturition also involves tissue-level inflammation within the myometrium. This study examined the control of PR-A abundance and transrepressive activity in myometrial cells and the role of the inflammatory stimuli in the form of interleukin-1β (IL-1β) and lipopolysaccharide (LPS) in these processes. We found that abundance of PR-A was markedly increased by progesterone and by exposure to IL-1β and LPS via posttranslational mechanisms involving increased PR-A protein stability. In contrast, progesterone decreased abundance of PR-B by increasing its rate of degradation. Together, progesterone and proinflammatory stimuli induced a PR-A–dominant state in myometrial cells similar to that observed in term laboring myometrium. IL-1β and LPS also increased the capacity for PR-A to inhibit the transcriptional activity of PR-B. Taken together, our data suggest that proinflammatory stimuli increase the steady-state levels of PR-A and its transrepressive activity in myometrial cells and support the hypothesis that tissue-level inflammation triggers parturition by inducing PR-A–mediated functional progesterone withdrawal. PMID:27886516

Deformation of the total ozone content field in the tropical zone

NASA Technical Reports Server (NTRS)

Vasilyev, Victor I.

1994-01-01

Presented are the ozone investigation results obtained in the tropical zone. Measurements of the total ozone content (TOC) were carried out by the ozonometer M-124. The ozonometer was automated to investigate the ozone intradiurnal variations and to increase precision of the TOC measurements. Obtained results allowed us to follow the effect of tropical cyclones (TC) on the TOC field. Several days before the TC formation the TOC increase is observed in daily mean course compared with the background one. Three types of trend can be singled out in the TOC intradiurnal course: zero, parabolic, quasi-linear. Maximum velocities of a trend are observed some days before the TC formation. Analogous harmonic constituents are mainly presented as spectrum of daily means of ozone, mean and absolute velocities of trend and dispersion as well as spectra of meteorological, hydrometeorological and actinometric values. Revealed is a number of day-to-day ozone variations concerned with large-scale circulations; moisture content in the atmosphere. Obtained are the data about short-period ozone waves (period less than a day). Thin-film silver sensors were used to measure the vertical ozone distribution (VOD). Atmospheric aerosol and VOD measurements were carried out simultaneously, they gave data of the VOD layered structure, where the VOD local minima coincided with the position of aerosol layers' maxima.

Analysis and validation of ozone variability observed by lidar during the ESCOMPTE-2001 campaign

NASA Astrophysics Data System (ADS)

Ancellet, G.; Ravetta, F.

2005-03-01

An ozone lidar was successfully operated as a ground-based instrument during the ESCOMPTE experiment in June/July 2001. Ozone profiles were measured between 0.5 and 5 km. Moreover, simultaneous measurements of the lidar scattering ratio (SR) at 316 nm diagnosed the diurnal evolution of the PBL top. Comparison of this data set with in-situ measurements by ultralight aircraft (ULM) and balloon soundings supports the existence of well-defined layers over the whole altitude range. Differences between measurements techniques are not due to instrumental inaccuracies but point towards the existence of ozone plumes with sharp horizontal gradients. This is indeed supported by aircraft horizontal cross-section available twice a day at two different levels in the planetary boundary layer (PBL) and the free troposphere. Analysis of the ozone data set has shown a good correlation between surface meteorological conditions, surface ozone measurements and lidar ozone profiles in the PBL. Observed ozone maxima or minima are linked either to sea breeze circulation bringing polluted air masses over the lidar or synoptic flows bringing air with background O 3 values into the region. The observed variability of the ozone field is very large over the whole altitude range. Although it is the result of local temporal variability and advection of spatial inhomogenities, the latter proved to be an important contribution.

Progesterone receptor isoforms expression pattern in the rat brain during the estrous cycle.

PubMed

Guerra-Araiza, C; Cerbón, M A; Morimoto, S; Camacho-Arroyo, I

2000-03-24

Progesterone receptor (PR) isoforms expression was determined in the hypothalamus, the preoptic area, the hippocampus and the frontal cerebral cortex of the rat at 12:00 h on each day of the estrous cycle by using reverse transcription coupled to polymerase chain reaction. Rats under a 14:10 h light-dark cycle, with lights on at 06:00 h were used. We found that PR-B isoform was predominant in the hypothalamus, the preoptic area and the frontal cerebral cortex. Both PR isoforms were similarly expressed in the hippocampus. The highest PR-B expression was found on proestrus day in the hypothalamus; on metestrus in the preoptic area; and on diestrus in the frontal cortex. We observed no changes in PR isoforms expression in the hippocampus during the estrous cycle. These results indicate that PR isoforms expression is differentially regulated during the estrous cycle in distinct brain regions and that PR-B may be involved in progesterone actions upon the hypothalamus, the preoptic area and the frontal cortex of the rat.

Microbiological characteristics of multi-media PRB reactor in the bioremediation of groundwater contaminated by petroleum hydrocarbons.

PubMed

Liu, Hong; Zhang, Lanying; Deng, Haijing; Liu, Na; Liu, Cuizhu

2011-10-01

A multi-media bio-PRB reactor was designed to treat groundwater contaminated with petroleum hydrocarbons. After a 208-day bioremediation, combined with the total petroleum hydrocarbons content in the groundwater flowed through the reactor, microbiological characteristics of the PRB reactor including microbes immobilized and its dehydrogenase activity were investigated. TPH was significantly reduced by as much as 65% in the back of the second media layer, whereas in the third layer, the TPH content reached lower than 1 mg l⁻¹. For microbes immobilized on the media, the variations with depth in different media were significantly the same and the regularity was obvious in the forepart of the media, which increased with depth at first and then reduced gradually, while in the back-end, the microbes almost did not have any variations with depth but decreased with the distance. The dehydrogenase activity varied from 2.98 to 16.16 mg TF L⁻¹ h⁻¹ and its distribution illustrated a similar trend with numbers of microbial cell, therefore, the noticeable correlation was found between them.

Pax6 Exerts Regional Control of Cortical Progenitor Proliferation via Direct Repression of Cdk6 and Hypophosphorylation of pRb

PubMed Central

Mi, Da; Carr, Catherine B.; Georgala, Petrina A.; Huang, Yu-Ting; Manuel, Martine N.; Jeanes, Emily; Niisato, Emi; Sansom, Stephen N.; Livesey, Frederick J.; Theil, Thomas; Hasenpusch-Theil, Kerstin; Simpson, T. Ian; Mason, John O.; Price, David J.

2013-01-01

Summary The mechanisms by which early spatiotemporal expression patterns of transcription factors such as Pax6 regulate cortical progenitors in a region-specific manner are poorly understood. Pax6 is expressed in a gradient across the developing cortex and is essential for normal corticogenesis. We found that constitutive or conditional loss of Pax6 increases cortical progenitor proliferation by amounts that vary regionally with normal Pax6 levels. We compared the gene expression profiles of equivalent Pax6-expressing progenitors isolated from Pax6+/+ and Pax6−/− cortices and identified many negatively regulated cell-cycle genes, including Cyclins and Cdks. Biochemical assays indicated that Pax6 directly represses Cdk6 expression. Cyclin/Cdk repression inhibits retinoblastoma protein (pRb) phosphorylation, thereby limiting the transcription of genes that directly promote the mechanics of the cell cycle, and we found that Pax6 inhibits pRb phosphorylation and represses genes involved in DNA replication. Our results indicate that Pax6’s modulation of cortical progenitor cell cycles is regional and direct. PMID:23622063

Performance of two differently designed permeable reactive barriers with sulfate and zinc solutions.

PubMed

Pérez, Norma; Schwarz, Alex O; Barahona, Esteban; Sanhueza, Pamela; Diaz, Isabel; Urrutia, Homero

2018-06-18

For the first time, this laboratory-scale study evaluates the feasibility of incorporating diffusive exchange in permeable reactive barriers. In order to do this, the performance of two permeable reactive barriers (PRB) with different internal substrate arrangements were compared during the administration of a sulfate solution without metals (for 163 days) and with metals (for 60 days), simulating groundwater contaminated with acid mine drainage (AMD). In order to simulate a traditional PRB, a homogeneous distribution was implemented in the first reactor and the other PRB reactor utilized diffusion-active technology (DAPRB). In the DAPRB, the distribution of the reactive material was interspersed with the conductive material. The measurements in the internal ports showed that transverse gradients of sulfide formed in the DAPRB, causing the diffusion of sulfide from the substrate toward the layer interface, which is where the sulfide reacts by forming complexes with the metal. The DAPRB prevents the microorganisms from direct contact with AMD. This protection caused greater activity (sulfide production). Copyright © 2018 Elsevier B.V. All rights reserved.

ATM Mediates pRB Function To Control DNMT1 Protein Stability and DNA Methylation

PubMed Central

Suzuki, Misa; Hayashi, Naoyuki; Kobayashi, Masahiko; Sasaki, Nobunari; Nishiuchi, Takumi; Doki, Yuichiro; Okamoto, Takahiro; Kohno, Susumu; Muranaka, Hayato; Kitajima, Shunsuke; Yamamoto, Ken-ichi

2013-01-01

The retinoblastoma tumor suppressor gene (RB) product has been implicated in epigenetic control of gene expression owing to its ability to physically bind to many chromatin modifiers. However, the biological and clinical significance of this activity was not well elucidated. To address this, we performed genetic and epigenetic analyses in an Rb-deficient mouse thyroid C cell tumor model. Here we report that the genetic interaction of Rb and ATM regulates DNMT1 protein stability and hence controls the DNA methylation status in the promoters of at least the Ink4a, Shc2, FoxO6, and Noggin genes. Furthermore, we demonstrate that inactivation of pRB promotes Tip60 (acetyltransferase)-dependent ATM activation; allows activated ATM to physically bind to DNMT1, forming a complex with Tip60 and UHRF1 (E3 ligase); and consequently accelerates DNMT1 ubiquitination driven by Tip60-dependent acetylation. Our results indicate that inactivation of the pRB pathway in coordination with aberration in the DNA damage response deregulates DNMT1 stability, leading to an abnormal DNA methylation pattern and malignant progression. PMID:23754744

Role of Biomass Burning in the Formation of Tropospheric Ozone Laminae

NASA Astrophysics Data System (ADS)

Nair, U. S.; Wu, Y.; Kuang, S.; Newchurch, M.

2016-12-01

Laminar structure in free-tropospheric ozone profiles is a feature that is frequently observed in ozonesonde and lidar observations. Origins of these features are not well understood and have been linked to tropopause folding, stratospheric warming events and biomass burning emissions. Ozone laminae events with maximum ozone exceeding 80 ppb have been observed by the DIfferential Absorption Lidar (DIAL) instrument in Huntsville, Alabama. While many of the events are linked to tropopause folding, a subset of events located in the mid troposphere (2-6km) coincided with a smoke layer are associated with biomass burning. Satellite observations show the smoke originated from northwestern US wildfire events. Several of these ozone laminae associated with smoke have ozone excess of 20 ppb above the background values and have the potential to impact surface air quality if they enter the boundary layer. This presentation will report on process studies of ozone laminae associated with biomass burning plumes using A-Train satellite, ground based DIAL and ozonesonde observations. Fate and transport of the feature is also examined using WRFChem simulations, in specific transport into the boundary layer and impact on air quality at the surface.

Reduction of date microbial load with ozone

PubMed Central

Farajzadeh, Davood; Qorbanpoor, Ali; Rafati, Hasan; Isfeedvajani, Mohsen Saberi

2013-01-01

Background: Date is one of the foodstuffs that are produced in tropical areas and used worldwide. Conventionally, methyl bromide and phosphine are used for date disinfection. The toxic side effects of these usual disinfectants have led food scientists to consider safer agents such as ozone for disinfection, because food safety is a top priority. The present study was performed to investigate the possibility of replacing common conventional disinfectants with ozone for date disinfection and microbial load reduction. Materials and Methods: In this experimental study, date samples were ozonized for 3 and 5 hours with 5 and 10 g/h concentrations and packed. Ozonized samples were divided into two groups and kept in an incubator which was maintained at 25°C and 40°C for 9 months. During this period, every 3 month, microbial load (bacteria, mold, and yeast) were examined in ozonized and non-ozonized samples. Results: This study showed that ozonization with 5 g/h for 3 hours, 5 g/h for 5 hours, 10 g/h for 3 hours, and 10 g/h for 5 hours leads to about 25%, 25%, 53%, and 46% reduction in date mold and yeast load and about 6%, 9%, 76%, and 74.7% reduction in date bacterial load at baseline phase, respectively. Appropriate concentration and duration of ozonization for microbial load reduction were 10 g/h and 3 hours. Conclusion: Date ozonization is an appropriate method for microbial load reduction and leads to an increase in the shelf life of dates. PMID:24124432

Interannual Variation in Baseline Ozone on the Western Coast of North America and Its Influence on Urban Air Quality

NASA Astrophysics Data System (ADS)

Wigder, N. L.; Jaffe, D. A.; Lin, M.; Fiore, A. M.; Macdonald, A.; Gong, S.

2011-12-01

Baseline ozone (O3) has been defined as the distribution of mixing ratios from a site when it is not influenced by locally emitted pollution (McDonald-Buller et al., 2011; NRC, 2009; TF HTAP, 2007). In this study, we set out to understand the interannual variation (IAV) in baseline O3 along the western coast of North America and its influence on surface air quality in urban environments. Baseline data for this study comes from Trinidad Head, CA, Mount Bachelor, OR, Cheeka Peak, WA, Jackson Visitor Center, WA and Whistler Mountain, BC. We address four key questions:

1. Do baseline observations on the western coast of North America exhibit similar IAV?
2. How well can satellites identify IAV in baseline O3 along the western coast of North America?
3. How does the baseline IAV influence urban air quality and O3 regulatory exceedance days?
4. How well can global chemical transport models capture the IAV in baseline O3?

Ozone Sensitivity and Catalase Activity in Pigmented and Non-Pigmented Strains of Serratia Marcescens

PubMed Central

de Ondarza, José

2017-01-01

Background: Ozone exposure rapidly leads to bacterial death, making ozone an effective disinfectant in food industry and health care arena. However, microbial defenses may moderate this effect and play a role in the effective use of oxidizing agents for disinfection. Serratia marcescens is an opportunistic pathogen, expressing genes differentially during infection of a human host. A better understanding of regulatory systems that control expression of Serratia’s virulence genes and defenses is therefore valuable. Objective: Here, we investigated the role of pigmentation and catalase in Serratia marcescens on survival to ozone exposure. Method: Pigmented and non-pigmented strains of Serratia marcescens were cultured to exponential or stationary phase and exposed to 5 ppm of gaseous ozone for 2.5 – 10 minutes. Survival was calculated via plate counts. Catalase activity was measured photometrically and tolerance to hydrogen peroxide was assayed by disk-diffusion. Results: Exposure of S. marcescens to 5 ppm gaseous ozone kills > 90% of cells within 10 minutes in a time and concentration-dependent manner. Although pigmented Serratia (grown at 28°C) survived ozonation better than unpigmented Serratia (grown at 35°C), non-pigmented mutant strains of Serratia had similar ozone survival rates, catalase activity and H2O2 tolerance as wild type strains. Rather, ozone survival and catalase activity were elevated in 6 hour cultures compared to 48 hour cultures. Conclusion: Our studies did not bear out a role for prodigiosin in ozone survival. Rather, induction of oxidative stress responses during exponential growth increased both catalase activity and ozone survival in both pigmented and unpigmented S. marcescens. PMID:28567147

Molecular targets in urothelial cancer: detection, treatment, and animal models of bladder cancer

PubMed Central

Smolensky, Dmitriy; Rathore, Kusum; Cekanova, Maria

2016-01-01

Bladder cancer remains one of the most expensive cancers to treat in the United States due to the length of required treatment and degree of recurrence. In order to treat bladder cancer more effectively, targeted therapies are being investigated. In order to use targeted therapy in a patient, it is important to provide a genetic background of the patient. Recent advances in genome sequencing, as well as transcriptome analysis, have identified major pathway components altered in bladder cancer. The purpose of this review is to provide a broad background on bladder cancer, including its causes, diagnosis, stages, treatments, animal models, as well as signaling pathways in bladder cancer. The major focus is given to the PI3K/AKT pathway, p53/pRb signaling pathways, and the histone modification machinery. Because several promising immunological therapies are also emerging in the treatment of bladder cancer, focus is also given on general activation of the immune system for the treatment of bladder cancer. PMID:27784990

IL-33 Drives Augmented Responses to Ozone in Obese Mice

PubMed Central

Mathews, Joel A.; Krishnamoorthy, Nandini; Kasahara, David Itiro; Cho, Youngji; Wurmbrand, Allison Patricia; Ribeiro, Luiza; Smith, Dirk; Umetsu, Dale; Levy, Bruce D.; Shore, Stephanie Ann

2016-01-01

Background: Ozone increases IL-33 in the lungs, and obesity augments the pulmonary effects of acute ozone exposure. Objectives: We assessed the role of IL-33 in the augmented effects of ozone observed in obese mice. Methods: Lean wildtype and obese db/db mice were pretreated with antibodies blocking the IL-33 receptor, ST2, and then exposed to ozone (2 ppm for 3 hr). Airway responsiveness was assessed, bronchoalveolar lavage (BAL) was performed, and lung cells harvested for flow cytometry 24 hr later. Effects of ozone were also assessed in obese and lean mice deficient in γδ T cells and their wildtype controls. Results and Discussion: Ozone caused greater increases in BAL IL-33, neutrophils, and airway responsiveness in obese than lean mice. Anti-ST2 reduced ozone-induced airway hyperresponsiveness and inflammation in obese mice but had no effect in lean mice. Obesity also augmented ozone-induced increases in BAL CXCL1 and IL-6, and in BAL type 2 cytokines, whereas anti-ST2 treatment reduced these cytokines. In obese mice, ozone increased lung IL-13+ innate lymphoid cells type 2 (ILC2) and IL-13+ γδ T cells. Ozone increased ST2+ γδ T cells, indicating that these cells can be targets of IL-33, and γδ T cell deficiency reduced obesity-related increases in the response to ozone, including increases in type 2 cytokines. Conclusions: Our data indicate that IL-33 contributes to augmented responses to ozone in obese mice. Obesity and ozone also interacted to promote type 2 cytokine production in γδ T cells and ILC2 in the lungs, which may contribute to the observed effects of IL-33. Citation: Mathews JA, Krishnamoorthy N, Kasahara DI, Cho Y, Wurmbrand AP, Ribeiro L, Smith D, Umetsu D, Levy BD, Shore SA. 2017. IL-33 drives augmented responses to ozone in obese mice. Environ Health Perspect 125:246–253; http://dx.doi.org/10.1289/EHP272 PMID:27472835

Source attribution of tropospheric ozone

NASA Astrophysics Data System (ADS)

Butler, T. M.

2015-12-01

Tropospheric ozone is a harmful pollutant with adverse effects on human health and ecosystems. As well as these effects, tropospheric ozone is also a powerful greenhouse gas, with an anthropogenic radiative forcing one quarter of that of CO2. Along with methane and atmospheric aerosol, tropospheric ozone belongs to the so-called Short Lived Climate forcing Pollutants, or SLCP. Recent work has shown that efforts to reduce concentrations of SLCP in the atmosphere have the potential to slow the rate of near-term climate change, while simultaneously improving public health and reducing crop losses. Unlike many other SLCP, tropospehric ozone is not directly emitted, but is instead influenced by two distinct sources: transport of air from the ozone-rich stratosphere; and photochemical production in the troposphere from the emitted precursors NOx (oxides of nitrogen), CO (Carbon Monoxide), and VOC (volatile organic compounds, including methane). Better understanding of the relationship between ozone production and the emissions of its precursors is essential for the development of targeted emission reduction strategies. Several modeling methods have been employed to relate the production of tropospheric ozone to emissions of its precursors; emissions perturbation, tagging, and adjoint sensitivity methods all deliver complementary information about modelled ozone production. Most studies using tagging methods have focused on attribution of tropospheric ozone production to emissions of NOx, even though perturbation methods have suggested that tropospheric ozone is also sensitive to VOC, particularly methane. In this study we describe the implementation into a global chemistry-climate model of a scheme for tagging emissions of NOx and VOC with an arbitrary number of labels, which are followed through the chemical reactions of tropospheric ozone production in order to perform attribution of tropospehric ozone to its emitted precursors. Attribution is performed to both geographical regions and to emission sectors. Source-receptor relationships are defined for intercontinental transport of ozone and its precursors, and the relative contributions of NOx, methane, CO, NMVOC, and stratosphere-troposphere exchange to tropospheric background ozone are determined.

Pollution transport from North America to Greenland during summer 2008

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

Thomas, J. L.; Raut, Jean-Christophe; Law, K. S.

2013-04-10

Ozone pollution transported to the Arctic is a significant concern because of the rapid, enhanced warming in high northern latitudes, which is caused, in part, by short lived climate forcers, such as ozone. Long range transport of pollution contributes to background and episodic ozone levels in the Arctic. However, the extent to which plumes are photochemically active during transport, particularly during the summer, is uncertain. Regional chemical transport model simulations are used to examine photochemical production 8 of ozone in air masses originating from boreal fire and anthropogenic emissions over North America and during their transport toward the Arctic duringmore » early July 2008. Model results shows good agreement with aircraft data collected over boreal fire source regions in Canada and several days down-wind over Greenland during the study period. Pollutant plumes were transported east and north towards the Arctic and show significant ozone enhancements downwind of source regions. Anthropogenic plumes were more photochemically active than fire plumes. Together, both sources made an important contribution to ozone in pollution plumes transported to the Arctic.« less

Pollution Transport From North America to Greenland During Summer 2008

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

Thomas, J. L.; Raut, Jean-Christophe; Law, K. S.

2013-04-10

Ozone pollution transported to the Arctic is a significant concern because of the rapid, enhanced warming in high northern latitudes, which is caused, in part, by short lived climate forcers, such as ozone. Long range transport of pollution contributes to background and episodic ozone levels in the Arctic. However, the extent to which plumes are photochemically active during transport, particularly during the summer, is uncertain. Regional chemical transport model simulations are used to examine photochemical production of ozone in air masses originating from boreal fire and anthropogenic emissions over North America and during their transport toward the Arctic during earlymore » July 2008. Model results shows good agreement with aircraft data collected over boreal fire source regions in Canada and several days downwind over Greenland during the study period. Pollutant plumes were transported east and north towards the Arctic and show significant ozone enhancements downwind of source regions. Anthropogenic plumes were more photochemically active than fire plumes. Together, both sources made an important contribution to ozone in pollution plumes transported to the Arctic.« less

Trace gases over Northern Eurasia: background level and disturbing factors

NASA Astrophysics Data System (ADS)

Skorokhod, A.; Shumsky, R.; Pankratova, N.; Moiseenko, K.; Vasileva, A.; Berezina, E.; Elansky, N.

2012-04-01

Atmospheric air composition over the vast and low inhabited areas of Northern Eurasia is still poorly studied because of lack of the precise direct measurements. This harms to accuracy of both global and regional models which simulate climatological and ecosystem changes in that highly important region. In this work background trace gases (such as O3, NO, NO2, CO) concentrations and their variability are considered on base of results of continuous measurements at ZOTTO station in the middle of Siberia which have been carried out since March, 2007. Also factors implying background regime (like long-range transport, wild fires emissions) are analyzed. To compliment study data of TROICA train-based campaigns which have been regularly provided across Russia for many years (1995-2010) are used. The concentration of ozone has a pronounced seasonal variation with a clear peak in spring (40-45 ppbv in average and up to 80 ppbv in extreme cases) and minimum in winter. Average ozone level is about 20 ppbv that corresponds to the background conditions. Enhanced concentration in March-July is due to increased stratospheric-tropospheric exchange. In autumn and winter distribution of ozone is close to uniform. Photochemical processes under low light and air temperature does not cause the generation of ozone. Sink on the snow surface is very small, and therefore the diurnal variations are absent. In general, seasonal variations correspond to the average seasonal course, which is typical for Russia. The analysis of diurnal ozone variations in Zotino in different seasons showed that the maximum rate of ozone formation is observed in summer from 9 to 15 h local time and is 1-2 ppbv/hour. It correlates well with the data on the isoprene emissions and others biogenic VOC reacting with OH- radical. Thus they are biogenic VOC emissions that seem to be the main factor of the lower troposphere oxidation power in summer. In other seasons it is significantly lower. NOx concentration does not exceed 1 ppb that is typical for background areas but may vary by order and some more in few hours. Higher surface NOx(=NO+NO2) concentrations during day time generally correspond to higher ozone when NO/NO2 ratio indicates on clean or slightly polluted conditions. If there are carbonaceous admixtures (, methane, VOC, etc.) in atmospheric air during the daytime, the NO level more than 10 - 20 ppb is enough for organic matter chain reactions, which lead to ozone accumulation in the atmosphere, to occur. There are almost no such conditions in the rural Siberia. Despite the prevailing western transport higher ozone (as well as other trace gases) concentrations are correlated with air of southern origin. Anthropogenic pollutants like NOx and CO come to Central Siberia mostly from industrial regions of Southern Siberia. Intrusions from China are not typical because of blocking Asian anticyclone. After analysis of surface ozone concentrations one may conclude that climatic conditions (light, temperature, wind conditions, etc.) and chemical composition of the main polluting components (NO, NO2, CO, methane, etc.) do not help (with rare exceptions) the active generation of ozone in the atmospheric air over Siberia. Nocturnal O3 dry deposition and soil emissions of CO2, CH4 were estimated for different parts of Siberia from radon measurements in TROICA experiments. The impact of wildfires on surface air composition over central Siberia is investigated based on near-surface carbon monoxide (CO) measurements conducted at ZOTTO during 2007 and 2008 warm seasons. Seasonal variations of intensity and spatial distribution of wildfires in south of western and eastern Siberia are found to be important factors contributing a substantial part of synoptic and year-to-year variability of background CO levels in the region. The estimated relative CO enhancement in fire plumes with transport times up to 2 days is about 5-25 ppb in springs 2007 and 2008, and 50 ppb in summer 2008, based on the observed median values, with a maximal absolute value of 250 ppb observed in April 2008. Boreal forest fires over the vast areas of central Siberia along with regional anthropogenic sources are found to be the major factors driving short-term (synoptic) variability of near-surface CO during the warm season. The work is fulfilled under support of Russian Foundation for Basic Research (projects ## 10-05-00317, 10-05-00214, 10-05-00272), of the RAS and the Ministry of Education and Science (State Contracts NN 02.740.11.0676 and 11.519.11.5007).

Aerosol indirect effect on tropospheric ozone via lightning

NASA Astrophysics Data System (ADS)

Yuan, T.; Remer, L. A.; Bian, H.; Ziemke, J. R.; Albrecht, R. I.; Pickering, K. E.; Oreopoulos, L.; Goodman, S. J.; Yu, H.; Allen, D. J.

2012-12-01

Tropospheric ozone (O3) is a pollutant and major greenhouse gas and its radiative forcing is still uncertain. The unresolved difference between modeled and observed natural background O3 concentrations is a key source of the uncertainty. Here we demonstrate remarkable sensitivity of lightning activity to aerosol loading with lightning activity increasing more than 30 times per unit of aerosol optical depth over our study area. We provide observational evidence that indicates the observed increase in lightning activity is caused by the influx of aerosols from a volcano. Satellite data analyses suggest O3 is increased as a result of aerosol-induced increase in lightning and lightning produced NOx. Model simulations with prescribed lightning change corroborate the satellite data analysis. This aerosol-O3 connection is achieved via aerosol increasing lightning and thus lightning produced nitrogen oxides. This aerosol-lightning-ozone link provides a potential physical mechanism that may account for a part of the model-observation difference in background O3 concentration. More importantly, O3 production increase from this link is concentrated in the upper troposphere, where O3 is most efficient as a greenhouse gas. Both of these implications suggest a stronger O3 historical radiative forcing. This introduces a new pathway, through which increasing in aerosols from pre-industrial time to present day enhances tropospheric O3 production. Aerosol forcing thus has a warming component via its effect on O3 production. Sensitivity simulations suggest that 4-8% increase of tropospheric ozone, mainly in the tropics, is expected if aerosol-lighting-ozone link is parameterized, depending on the background emission scenario. We note, however, substantial uncertainties remain on the exact magnitude of aerosol effect on tropospheric O3 via lightning. The challenges for obtaining a quantitative global estimate of this effect are also discussed. Our results have significant implications for understanding past and projecting future tropospheric O3 forcing as well as wildfire changes and call for integrated investigations of the coupled aerosol-cloud-chemistry system.

Navy Ship Propulsion Technologies: Options for Reducing Oil Use - Background for Congress

DTIC Science & Technology

2006-12-11

Change, Energy Efficiency, and Ozone Protection, Protecting National Security and the Environment. Washington, 2000. (Office of the Deputy Under...Shipboard Fuel Consumption and Emissions,” op. cit., and Climate Change, Energy Efficiency, and Ozone Protection, Protecting National Security and the...with the SkySails technology trouble-free.74 CRS-28 75 “The Economic and Sustainable Utilisation in the Cargo Shipping Industry of Wind Power,” HSB

Quantifying Ozone Production throughout the Boundary Layer from High Frequency Tethered Profile Measurements during a High Ozone Episode in the Uinta Basin, Utah

NASA Astrophysics Data System (ADS)

Sterling, C. W.; Johnson, B.; Schnell, R. C.; Oltmans, S. J.; Cullis, P.; Hall, E. G.; Jordan, A. F.; Windell, J.; McClure-Begley, A.; Helmig, D.; Petron, G.

2015-12-01

During the Uinta Basin Winter Ozone Study (UBWOS) in Jan - Feb 2013, 735 tethered ozonesonde profiles were obtained at 3 sites including during high wintertime photochemical ozone production events that regularly exceeded 125 ppb. High resolution profiles of ozone and temperature with altitude, measured during daylight hours, showed the development of approximately week long high ozone episodes building from background levels of ~40 ppb to >150 ppb. The topography of the basin combined with a strong temperature inversion trapped oil and gas production effluents in the basin and the snow covered surface amplified the sun's radiation driving the photochemical ozone production at rates up to 13 ppb/hour in a cold layer capped at 1600-1700 meters above sea level. Beginning in mid-morning, ozone mixing ratios throughout the cold layer increased until late afternoon. Ozone mixing ratios were generally constant with height indicating that ozone production was nearly uniform throughout the depth of the cold pool. Although there was strong diurnal variation, ozone mixing ratios increased during the day more than decreased during the night, resulting in elevated levels the next morning; an indication that nighttime loss processes did not compensate for daytime production. Even though the 3 tethersonde sites were at elevations differing by as much as 140 m, the top of the high ozone layer was nearly uniform in altitude at the 3 locations. Mobile van surface ozone measurements across the basin confirmed this capped structure of the ozone layer; the vehicle drove out of high ozone mixing ratios at an elevation of ~1900 meters above sea level, above which free tropospheric ozone mixing ratios of ~50 ppb were measured. Exhaust plumes from a coal-fired power plant in the eastern portion of the basin were intercepted by the tethersondes. The structure of the profiles clearly showed that effluents in the plumes were not mixed downward and thus did not contribute precursor nitrogen oxides to the observed ozone production in the boundary layer.

Ozone destruction through heterogeneous chemistry following the eruption of El Chichon

NASA Technical Reports Server (NTRS)

Hofmann, David J.; Solomon, Susan

1989-01-01

The results of ozone observations at northern midlatitudes in late 1982 through 1983, following the eruption of El Chichon are discussed, together with the observations of other trace gases which may be linked to possible variations in ozone chemistry. These results are related to the in situ aerosol observations following the El Chicon eruption, with particular attention given to data relevant to heterogeneous reactions, such as the aerosol surface area and weight percent H2SO4. It is shown that, at midlatitudes, the observed volcanic-particle surface area reached a maximum of about 50 sq microns/cu m (above a typical background value of about 0.75) at an altitude of 18-20 km in early 1983; this enhancement of surface area is about the same as that encountered in stratospheric clouds in the Antarctic, suggesting a possible basis for ozone depletion through heterogeneous chemistry. The fraction of ozone reduction that may have occurred as a result of heterogeneous chemicl effects is estimated.

Effects of sulfate ligand on uranyl carbonato surface species on ferrihydrite surfaces

USGS Publications Warehouse

Arai, Yuji; Fuller, C.C.

2012-01-01

Understanding uranium (U) sorption processes in permeable reactive barriers (PRB) are critical in modeling reactive transport for evaluating PRB performance at the Fry Canyon demonstration site in Utah, USA. To gain insight into the U sequestration mechanism in the amorphous ferric oxyhydroxide (AFO)-coated gravel PRB, U(VI) sorption processes on ferrihydrite surfaces were studied in 0.01 M Na2SO4 solutions to simulate the major chemical composition of U-contaminatedgroundwater (i.e., [SO42-]~13 mM L-1) at the site. Uranyl sorption was greater at pH 7.5 than that at pH 4 in both air- and 2% pCO2-equilibrated systems. While there were negligible effects of sulfate ligands on the pH-dependent U(VI) sorption (<24 h) in both systems, X-ray absorption spectroscopy (XAS) analysis showed sulfate ligand associated U(VI) surface species at the ferrihydrite–water interface. In air-equilibrated systems, binary and mono-sulfate U(VI) ternary surface species co-existed at pH 5.43. At pH 6.55–7.83, a mixture of mono-sulfate and bis-carbonato U(VI) ternary surface species became more important. At 2% pCO2, there was no contribution of sulfate ligands on the U(VI) ternary surface species. Instead, a mixture of bis-carbonato inner-sphere (38%) and tris-carbonato outer-sphere U(VI) ternary surface species (62%) was found at pH 7.62. The study suggests that the competitive ligand (bicarbonate and sulfate) coordination on U(VI) surface species might be important in evaluating the U solid-state speciation in the AFO PRB at the study site where pCO2 fluctuates between 1 and 2 pCO2%.

Prognostic value of the expression of tumor suppressor genes p53, p21, p16 and prb, and Ki-67 labelling in high grade astrocytomas treated with radiotherapy.

PubMed

Kirla, R; Salminen, E; Huhtala, S; Nuutinen, J; Talve, L; Haapasalo, H; Kalimo, H

2000-01-01

Cumulative inactivation of tumor suppressor genes and/or amplification of oncogenes lead to progressively more malignant astrocytic tumors. We have analyzed the significance of tumor suppressor genes p53, p21, p16 and retinoblastoma protein (pRb) and proliferative activity for survival in 77 high grade astrocytic tumors. After operation, the patients--25 anaplastic astrocytomas (AA) and 52 glioblastomas (GBs)--were treated with similar radiotherapy. The expression of the suppressor genes and the proliferative activity were analyzed immunohistochemically. p53 immunopositivity was found in 44% of AAs and 46% of GBs. Tumors with aberrant p53 expression had lower proliferation indices than p53 immunonegative tumors. Neither p53 expression nor p21 immunonegativity (52% of AAs and 48% of GBs) correlated with survival. p16 immunostaining was negative in 16% of AAs and in 44% of GBs, and it correlated inversely with survival in both uni- and multivariate analyses. pRb immunostaining was negative only in 8% of both AAs and GBs and the absence of p16 and pRb were mutually exclusive. Ki-67 labelling index (LI) was significantly higher in GBs (26.8%) than in AAs (20.3%), and in multivariate analysis it was an independent prognostic factor for survival. In 48% of AAs Ki-67 LI exceeded 20% and this subset of AAs had similar prognosis as GB. In high grade astrocytic tumors p16 immunonegativity was an independent indicator of poor prognosis in addition to the previously established patient's age, histopathology and Ki-67 LI. Furthermore, there was a subset of AAs with a high proliferation rate (> 20%) in which the histopathological hallmarks of GB were lacking, but which had similarly dismal prognosis as GB.

Comparative burial and thermal history of lower Upper Cretaceous strata, Powder River basin, Wyoming

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

Nuccio, V.F.

1989-03-01

Burial histories were reconstructed for three localities in the Powder River basin (PRB), Wyoming. Thermal maturity of lower Upper Cretaceous source rocks was determined by vitrinite reflectance (R/sub m/) and time-temperature index (TTI) modeling, producing independent estimates for timing of the oil window (0.55-1.35% R/sub m/). In the northwestern PRB, lower Upper Cretaceous rocks were buried to about 12,500 ft and achieved a thermal maturity of 0.50% to 0.56% at maximum burial, 10 Ma, based on measured R/sub m/. TTI modeling suggests a slightly higher thermal maturity, with an R/sub m/ equivalent of approximately 0.75%, placing the source rocks atmore » the beginning of the oil window 30 Ma. In the southwestern PRB, lower Upper Cretaceous rocks have been buried to about 15,000 ft and achieved thermal maturities between 0.66% and 0.75% about 10 Ma based on measured R/sub m/; therefore, petroleum generation may have begun slightly earlier. TTI modeling estimates an R/sub m/ equivalent of 1.10%, placing the beginning of the oil window at 45 Ma. In the northeastern PRB, lower Upper Cretaceous rocks have been buried only to approximately 5500 ft. Measured R/sub m/ and TTI modeling indicate a thermal maturity for lower Upper Cretaceous rocks between 0.45% and 0.50% R/sub m/, too low for petroleum generation. The higher R/sub m/ values determined by the TTI models may be due to overestimation of maximum burial depth and/or paleogeothermal gradients. The two independent maturity indicators do, however, constrain fairly narrowly the onset of petroleum generation.« less

Proteolysis suppresses spontaneous prion generation in yeast.

PubMed

Okamoto, Atsushi; Hosoda, Nao; Tanaka, Anri; Newnam, Gary P; Chernoff, Yury O; Hoshino, Shin-Ichi

2017-12-08

Prions are infectious proteins that cause fatal neurodegenerative disorders including Creutzfeldt-Jakob and bovine spongiform encephalopathy (mad cow) diseases. The yeast [ PSI + ] prion is formed by the translation-termination factor Sup35, is the best-studied prion, and provides a useful model system for studying such diseases. However, despite recent progress in the understanding of prion diseases, the cellular defense mechanism against prions has not been elucidated. Here, we report that proteolytic cleavage of Sup35 suppresses spontaneous de novo generation of the [ PSI + ] prion. We found that during yeast growth in glucose media, a maximum of 40% of Sup35 is cleaved at its N-terminal prion domain. This cleavage requires the vacuolar proteases PrA-PrB. Cleavage occurs in a manner dependent on translation but independently of autophagy between the glutamine/asparagine-rich (Q/N-rich) stretch critical for prion formation and the oligopeptide-repeat region required for prion maintenance, resulting in the removal of the Q/N-rich stretch from the Sup35 N terminus. The complete inhibition of Sup35 cleavage, by knocking out either PrA ( pep4 Δ) or PrB ( prb1 Δ), increased the rate of de novo formation of [ PSI + ] prion up to ∼5-fold, whereas the activation of Sup35 cleavage, by overproducing PrB, inhibited [ PSI + ] formation. On the other hand, activation of the PrB pathway neither cleaved the amyloid conformers of Sup35 in [ PSI + ] strains nor eliminated preexisting [ PSI + ]. These findings point to a mechanism antagonizing prion generation in yeast. Our results underscore the usefulness of the yeast [ PSI + ] prion as a model system to investigate defense mechanisms against prion diseases and other amyloidoses. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

Enhancement of mercury capture by the simultaneous addition of hydrogen bromide (HBr) and fly ashes in a slipstream facility.

PubMed

Cao, Yan; Wang, Quan-Hai; Li, Jun; Cheng, Jen-Chieh; Chan, Chia-Chun; Cohron, Marten; Pan, Wei-Ping

2009-04-15

Low halogen content in tested Powder River Basin (PRB) coals and low loss of ignition content (LOI) in PRB-derived fly ash were likely responsible for higher elemental mercury content (averaging about 75%) in the flue gas and also lower mercury capture efficiency by electrostatic precipitator (ESP) and wet-FGD. To develop a cost-effective approach to mercury capture in a full-scale coal-fired utility boiler burning PRB coal, experiments were conducted adding hydrogen bromide (HBr) or simultaneously adding HBr and selected fly ashes in a slipstream reactor (0.152 x 0.152 m) under real flue gas conditions. The residence time of the flue gas inside the reactorwas about 1.4 s. The average temperature of the slipstream reactor was controlled at about 155 degrees C. Tests were organized into two phases. In Phase 1, only HBr was added to the slipstream reactor, and in Phase 2, HBr and selected fly ash were added simultaneously. HBr injection was effective (>90%) for mercury oxidation at a low temperature (155 degrees C) with an HBr addition concentration of about 4 ppm in the flue gas. Additionally, injected HBr enhanced mercury capture by PRB fly ash in the low-temperature range. The mercury capture efficiency, attesting conditions of the slipstream reactor, reached about 50% at an HBr injection concentration of 4 ppm in the flue gas. Compared to only the addition of HBr, simultaneously adding bituminous-derived fly ash in a minimum amount (30 lb/MMacf), together with HBr injection at 4 ppm, could increase mercury capture efficiency by 30%. Injection of lignite-derived fly ash at 30 lb/MMacf could achieve even higher mercury removal efficiency (an additional 35% mercury capture efficiency compared to HBr addition alone).

Microbial community activities during establishment, performance, and decline of bench-scale passive treatment systems for mine drainage.

PubMed

Logan, Miranda V; Reardon, Kenneth F; Figueroa, Linda A; McLain, Jean E T; Ahmann, Dianne M

2005-11-01

Permeable reactive barrier (PRB) technology, in which sulfate-reducing bacteria (SRB) facilitate precipitation of metal sulfides, is a promising approach for remediation of sulfate- and metal-laden mine drainage. While PRBs are easily established, they often decline for reasons not well understood. SRB depend on or compete with multiple dynamic microbial populations within a PRB; as a result, performance depends on the changing PRB chemical composition and on succession and competition within the microbial community. To investigate these interactions, we constructed and monitored eight bench-scale PRBs to define periods of establishment, performance, and decline. We then conducted short-term batch studies, using substrate-supplemented column materials, on Days 0 (pre-establishment), 27 (establishment), 41 (performance), and 99 (decline) to reveal potential activities of cellulolytic bacteria, fermenters + anaerobic respirers, SRB, and methanogens. PRBs showed active sulfate reduction, with sulfate removal rates (SRR) of approximately 1-3 mol/m3/d, as well as effective removal of Zn2+. Potential activities of fermentative + anaerobic respiratory bacteria were initially high but diminished greatly during establishment and dropped further during performance and decline. In contrast, potential SRB activity rose during establishment, peaked during performance, and diminished as performance declined. Potential methanogen activity was low; in addition, SRB-methanogen substrate competition was shown not to limit SRB activity. Cellulolytic bacteria showed no substrate limitation at any time. However, fermenters experienced substrate limitation by Day 0, SRB by Day 27, and methanogens by Day 41, showing the dependence of each group on upstream populations to provide substrates. All potential activities, except methanogenesis, were ultimately limited by cellulose hydrolysis; in addition, all potential activities except methanogenesis declined substantially by Day 99, showing that long-term substrate deprivation strongly diminished the intrinsic capacity of the PRB community to perform.

Effects of sulfate ligand on uranyl carbonato surface species on ferrihydrite surfaces.

PubMed

Arai, Yuji; Fuller, C C

2012-01-01

Understanding uranium (U) sorption processes in permeable reactive barriers (PRB) are critical in modeling reactive transport for evaluating PRB performance at the Fry Canyon demonstration site in Utah, USA. To gain insight into the U sequestration mechanism in the amorphous ferric oxyhydroxide (AFO)-coated gravel PRB, U(VI) sorption processes on ferrihydrite surfaces were studied in 0.01 M Na(2)SO(4) solutions to simulate the major chemical composition of U-contaminated groundwater (i.e., [SO(4)(2-)] ~13 mM L(-1)) at the site. Uranyl sorption was greater at pH 7.5 than that at pH 4 in both air- and 2% pCO(2)-equilibrated systems. While there were negligible effects of sulfate ligands on the pH-dependent U(VI) sorption (<24 h) in both systems, X-ray absorption spectroscopy (XAS) analysis showed sulfate ligand associated U(VI) surface species at the ferrihydrite-water interface. In air-equilibrated systems, binary and mono-sulfate U(VI) ternary surface species co-existed at pH 5.43. At pH 6.55-7.83, a mixture of mono-sulfate and bis-carbonato U(VI) ternary surface species became more important. At 2% pCO(2), there was no contribution of sulfate ligands on the U(VI) ternary surface species. Instead, a mixture of bis-carbonato inner-sphere (38%) and tris-carbonato outer-sphere U(VI) ternary surface species (62%) was found at pH 7.62. The study suggests that the competitive ligand (bicarbonate and sulfate) coordination on U(VI) surface species might be important in evaluating the U solid-state speciation in the AFO PRB at the study site where pCO(2) fluctuates between 1 and 2 pCO(2)%. Copyright © 2011 Elsevier Inc. All rights reserved.

Tropospheric ozone and its precursors from the urban to the global scale from air quality to short-lived climate forcer

NASA Astrophysics Data System (ADS)

Monks, P. S.; Archibald, A. T.; Colette, A.; Cooper, O.; Coyle, M.; Derwent, R.; Fowler, D.; Granier, C.; Law, K. S.; Mills, G. E.; Stevenson, D. S.; Tarasova, O.; Thouret, V.; von Schneidemesser, E.; Sommariva, R.; Wild, O.; Williams, M. L.

2015-08-01

Ozone holds a certain fascination in atmospheric science. It is ubiquitous in the atmosphere, central to tropospheric oxidation chemistry, yet harmful to human and ecosystem health as well as being an important greenhouse gas. It is not emitted into the atmosphere but is a byproduct of the very oxidation chemistry it largely initiates. Much effort is focused on the reduction of surface levels of ozone owing to its health and vegetation impacts, but recent efforts to achieve reductions in exposure at a country scale have proved difficult to achieve owing to increases in background ozone at the zonal hemispheric scale. There is also a growing realisation that the role of ozone as a short-lived climate pollutant could be important in integrated air quality climate change mitigation. This review examines current understanding of the processes regulating tropospheric ozone at global to local scales from both measurements and models. It takes the view that knowledge across the scales is important for dealing with air quality and climate change in a synergistic manner. The review shows that there remain a number of clear challenges for ozone such as explaining surface trends, incorporating new chemical understanding, ozone-climate coupling, and a better assessment of impacts. There is a clear and present need to treat ozone across the range of scales, a transboundary issue, but with an emphasis on the hemispheric scales. New observational opportunities are offered both by satellites and small sensors that bridge the scales.

Modeling of Regional Climate Change Effects on Ground-Level Ozone and Childhood Asthma

PubMed Central

Sheffield, Perry E.; Knowlton, Kim; Carr, Jessie L.; Kinney, Patrick L.

2011-01-01

Background The adverse respiratory effects of ground-level ozone are well-established. Ozone is the air pollutant most consistently projected to increase under future climate change. Purpose To project future pediatric asthma emergency department visits associated with ground-level ozone changes, comparing 1990s to 2020s. Methods This study assessed future numbers of asthma emergency department visits for children aged 0–17 years using (1) baseline New York City metropolitan area emergency department rates, (2) a dose–response relationship between ozone levels and pediatric asthma emergency department visits, and (3) projected daily 8-hour maximum ozone concentrations for the 2020s as simulated by a global-to-regional climate change and atmospheric chemistry model. Sensitivity analyses included population projections and ozone precursor changes. This analysis occurred in 2010. Results In this model, climate change could cause an increase in regional summer ozone-related asthma emergency department visits for children aged 0–17 years of 7.3% across the New York City metropolitan region by the 2020s. This effect diminished with inclusion of ozone precursor changes. When population growth is included, the projections of morbidity related to ozone are even larger. Conclusions The results of this analysis demonstrate that the use of regional climate and atmospheric chemistry models make possible the projection of local climate change health effects for specific age groups and specific disease outcomes – such as emergency department visits for asthma. Efforts should be made to improve on this type of modeling to inform local and wider-scale climate change mitigation and adaptation policy. PMID:21855738

Proteomic differences with and without ozone-exposure in a smoking-induced emphysema lung model

PubMed Central

Uh, Soo-Taek; Koo, So-My; Jang, An Soo; Park, Sung Woo; Choi, Jae Sung; Kim, Yong-Hoon

2015-01-01

Background/Aims Acute exacerbations in chronic obstructive pulmonary disease may be related to air pollution, of which ozone is an important constituent. In this study, we investigated the protein profiles associated with ozone-induced exacerbations in a smoking-induced emphysema model. Methods Mice were divided into the following groups: group I, no smoking and no ozone (NS + NO); group II, no smoking and ozone (NS + O); group III, smoking and no ozone (S + NO); and group IV, smoking and ozone (S + O). Bronchoalveolar lavage, the mean linear intercept (MLI) on hematoxylin and eosin staining, nano-liquid chromatography-tandem mass spectrometry (LC-MS/MS), and Western blotting analyses were performed. Results The MLIs of groups III (S + NO) and IV (S + O) (45 ± 2 and 44 ± 3 µm, respectively) were significantly higher than those of groups I (NS + NO) and II (NS + O) (26 ± 2 and 23 ± 2 µm, respectively; p < 0.05). Fourteen spots that showed significantly different intensities on image analyses of two-dimensional (2D) protein electrophoresis in group I (NS + NO) were identified by LC-MS/MS. The levels of six proteins were higher in group IV (S + O). The levels of vimentin, lactate dehydrogenase A, and triose phosphate isomerase were decreased by both smoking and ozone treatment in Western blotting and proteomic analyses. In contrast, TBC1 domain family 5 (TBC1D5) and lamin A were increased by both smoking and ozone treatment. Conclusions TBC1D5 could be a biomarker of ozone-induced lung injury in emphysema. PMID:25589837

Recent Biomass Burning in the Tropics and Related Changes in Tropospheric Ozone

NASA Technical Reports Server (NTRS)

Ziemke; Chandra, J. R. S.; Duncan, B. N.; Schoeberl, M. R.; Torres, O.; Damon, M. R.; Bhartia, P. K.

2009-01-01

Biomass burning is an important source of chemical precursors of tropospheric ozone. In the tropics, biomass burning produces ozone enhancements over broad regions of Indonesia, Africa, and South America including Brazil. Fires are intentionally set in these regions during the dry season each year to clear cropland and to clear land for human/industrial expansion. In Indonesia enhanced burning occurs during dry El Nino conditions such as in 1997 and 2006. These burning activities cause enhancement in atmospheric particulates and trace gases which are harmful to human health. Measurements from the Aura Ozone Monitoring Instrument (OMI) and Microwave Limb Sounder (MLS) from October 2004-November 2008 are used to evaluate the effects of biomass burning on tropical tropospheric ozone. These measurements show sizeable decreases approx.15-20% in ozone in Brazil during 2008 compared to 2007 which we attribute to the reduction in biomass burning. Three broad biomass burning regions in the tropics (South America including Brazil, western Africa, and Indonesia) were analyzed in the context of OMI/MLS measurements and the Global Modeling Initiative (GMI) chemical transport model developed at Goddard Space Flight Center. The results indicate that the impact of biomass burning on ozone is significant within and near the burning regions with increases of approx.10-25% in tropospheric column ozone relative to average background concentrations. The model suggests that about half of the increases in ozone from these burning events come from altitudes below 3 km. Globally the model indicates increases of approx.4-5% in ozone, approx.7-9% in NO, (NO+NO2), and approx.30-40% in CO.

Modulations of stratospheric ozone by volcanic eruptions

NASA Technical Reports Server (NTRS)

Blanchette, Christian; Mcconnell, John C.

1994-01-01

We have used a time series of aerosol surface based on the measurements of Hofmann to investigate the modulation of total column ozone caused by the perturbation to gas phase chemistry by the reaction N2O5(gas) + H2O(aero) yields 2HNO3(gas) on the surface of stratospheric aerosols. We have tested a range of values for its reaction probability, gamma = 0.02, 0.13, and 0.26 which we compared to unperturbed homogeneous chemistry. Our analysis spans a period from Jan. 1974 to Oct. 1994. The results suggest that if lower values of gamma are the norm then we would expect larger ozone losses for highly enhanced aerosol content that for larger values of gamma. The ozone layer is more sensitive to the magnitude of the reaction probability under background conditions than during volcanically active periods. For most conditions, the conversion of NO2 to HNO3 is saturated for reaction probability in the range of laboratory measurements, but is only absolutely saturated following major volcanic eruptions when the heterogeneous loss dominates the losses of N2O5. The ozone loss due to this heterogeneous reaction increases with the increasing chlorine load. Total ozone losses calculated are comparable to ozone losses reported from TOMS and Dobson data.

Impact of synoptic controls and boundary layer processes on ground-level ozone evolution at an urban site

NASA Astrophysics Data System (ADS)

Haman, Christine Lanier

Houston, Texas frequently exceeds the standard for ground-level ozone during the spring and fall. The large commuting population and vast number of industrial sources provide the necessary ingredients for photochemical ozone production in the presence of favorable meteorological conditions. The lack of continuous boundary layer (BL) observations prevents a comprehensive understanding of its role in ozone evolution. In this study, almost two years of BL observations are utilized to investigate the impacts of synoptic and micrometeorological-scale forcings on ozone. Aerosol gradients derived from ceilometer backscatter retrievals are used to identify the BL and residual layers (RL). Overall agreement is found between ceilometer and sonde estimates of the RL and BL heights (BLH), but difficulty detecting the layers occurs during cloud periods or immediately following precipitation. Large monthly variability is present in the peak afternoon BLH (e.g. mean August and December peaks are ˜2000 and 1100 m, respectively). Monthly nocturnal BLHs display much smaller differences. The majority of ozone exceedances occur during large-scale subsidence and weak winds in a postfrontal environment. These conditions result in turbulent kinetic energy, mechanical mixing, and ventilation processes that are 2--3 times weaker on exceedance days, which inhibit morning BL growth by an average of ˜100 m·hr-1 compared to low ozone days. The spring has higher nocturnal ozone levels, which is likely attributable to longer day lengths (˜78 minutes), stronger winds (˜0.78 m·s -1), and higher background ozone (˜5 ppbv) compared to the fall. Boundary layer entrainment plays an important role in ozone evolution. Exceedance days show a characteristic early morning rapid rise of ozone. Vertical ozone profiles indicate the RL ozone peak is ˜60 ppbv on exceedance days, which is ˜25 ppbv (+/- 10 ppbv) greater than low ozone days. The Integrated Profile Mixing (IPM) and Photochemical Budget (PB) methods are used to quantify ozone transport and photochemical production. On low ozone days, both the IPM and PB methods indicate ozone entrainment is ˜3--4 ppbv·hr-1 in this low photochemical environment of ˜1--4 ppbv·hr-1. During the rapid early morning ozone rise on exceedance days, RL entrainment and photochemical ozone production rates are 5--10 and 10--15 ppbv·hr -1, respectively.

Navy Ship Propulsion Technologies: Options for Reducing Oil Use - Background for Congress

DTIC Science & Technology

2006-07-26

at [http://www50.dt.navy.mil/reports/hydrobulb/]. 10 U.S. Department of Defense, Climate Change, Energy Efficiency, and Ozone Protection, Protecting...Vessels, Reducing Shipboard Fuel Consumption and Emissions,” op cit, and Climate Change, Energy Efficiency, and Ozone Protection, Protecting National...retrofitted with the SkySails technology trouble-free.67 CRS-26 68 “The Economic and Sustainable Utilisation in the Cargo Shipping Industry of Wind

Ozone exposure of a weed community produces adaptive changes in seed populations of Spergula arvensis.

PubMed

Landesmann, Jennifer B; Gundel, Pedro E; Martínez-Ghersa, M Alejandra; Ghersa, Claudio M

2013-01-01

Tropospheric ozone is one of the major drivers of global change. This stress factor alters plant growth and development. Ozone could act as a selection pressure on species communities composition, but also on population genetic background, thus affecting life history traits. Our objective was to evaluate the consequences of prolonged ozone exposure of a weed community on phenotypic traits of Spergulaarvensis linked to persistence. Specifically, we predicted that the selection pressure exerted by high ozone concentrations as well as the concomitant changes in the weed community would drive population adaptive changes which will be reflected on seed germination, dormancy and longevity. In order to test seed viability and dormancy level, we conducted germination experiments for which we used seeds produced by S. arvensis plants grown within a weed community exposed to three ozone treatments during four years (0, 90 and 120 ppb). We also performed a soil seed bank experiment to test seed longevity with seeds coming from both the four-year ozone exposure experiment and from a short-term treatment conducted at ambient and added ozone concentrations. We found that prolonged ozone exposure produced changes in seed germination, dormancy and longevity, resulting in three S. arvensis populations. Seeds from the 90 ppb ozone selection treatment had the highest level of germination when stored at 75% RH and 25 °C and then scarified. These seeds showed the lowest dormancy level when being subjected to 5 ºC/5% RH and 25 ºC/75% followed by 5% RH storage conditions. Furthermore, ozone exposure increased seed persistence in the soil through a maternal effect. Given that tropospheric ozone is an important pollutant in rural areas, changes in seed traits due to ozone exposure could increase weed persistence in fields, thus affecting weed-crop interactions, which could ultimately reduce crop production.

Ozone Exposure of a Weed Community Produces Adaptive Changes in Seed Populations of Spergula arvensis

PubMed Central

Landesmann, Jennifer B.; Gundel, Pedro E.; Martínez-Ghersa, M. Alejandra; Ghersa, Claudio M.

2013-01-01

Tropospheric ozone is one of the major drivers of global change. This stress factor alters plant growth and development. Ozone could act as a selection pressure on species communities composition, but also on population genetic background, thus affecting life history traits. Our objective was to evaluate the consequences of prolonged ozone exposure of a weed community on phenotypic traits of Spergula arvensis linked to persistence. Specifically, we predicted that the selection pressure exerted by high ozone concentrations as well as the concomitant changes in the weed community would drive population adaptive changes which will be reflected on seed germination, dormancy and longevity. In order to test seed viability and dormancy level, we conducted germination experiments for which we used seeds produced by S. arvensis plants grown within a weed community exposed to three ozone treatments during four years (0, 90 and 120 ppb). We also performed a soil seed bank experiment to test seed longevity with seeds coming from both the four-year ozone exposure experiment and from a short-term treatment conducted at ambient and added ozone concentrations. We found that prolonged ozone exposure produced changes in seed germination, dormancy and longevity, resulting in three S. arvensis populations. Seeds from the 90 ppb ozone selection treatment had the highest level of germination when stored at 75% RH and 25 °C and then scarified. These seeds showed the lowest dormancy level when being subjected to 5 ºC/5% RH and 25 ºC/75% followed by 5% RH storage conditions. Furthermore, ozone exposure increased seed persistence in the soil through a maternal effect. Given that tropospheric ozone is an important pollutant in rural areas, changes in seed traits due to ozone exposure could increase weed persistence in fields, thus affecting weed-crop interactions, which could ultimately reduce crop production. PMID:24086640

Gametophyte differentiation and imprinting control in plants: Crosstalk between RBR and chromatin.

PubMed

Johnston, Amal J; Gruissem, Wilhelm

2009-01-01

The Retinoblastoma (pRb) pathway has been implicated as a convergent regulatory unit in the control of cell cycle and disease. We have shown that a crosstalk between RETINOBLASTOMA RELATED (RBR), the Arabidopsis homologue of pRb, and the genes encoding proteins of the chromatin complexes involved in DNA or histone methylation, controls gametophytic and post-fertilization differentiation events and a subset of imprinting effects. We describe here a plausible model that incorporates several components of the plant Retinoblastoma pathway, thus offering a novel paradigm that merges the traditional cell cycle and the chromatin components in the control of cell differentiation and imprinting.

Reversible electrokinetic adsorption barriers for the removal of organochlorine herbicide from spiked soils.

PubMed

Rodrigo, S; Saez, C; Cañizares, P; Rodrigo, M A

2018-06-02

This work aims to describe the removal of clopyralid from clay soils using electrokinetically assisted soil flushing (EKSF) coupled with a permeable reactive barrier (PRB), consisting of beds of Granulated Activated Carbon (GAC). To do this, two strategies have been evaluated on bench-scale electroremediation facilities (175 dm 3 ): electrokinetic adsorption barrier (EKAB) and reversible electrokinetic adsorption barrier (REKAB). Likewise, to clarify the contribution of the different mechanisms to remediation process results are compared to those obtained in a reference test (without applying an electric field) and to results obtained in the EKSF of soils polluted with compounds with different polarity and vapour pressure. Results show that during EKAB and REKAB tests, clopyralid is removed from the soil by adsorption in PRB, electrokinetic transport and, very less decisively, by evaporation. The application of polarity reversion attains a higher retention of clopyralid in the activated carbon-PRB and a better regulation of pH because of the neutralization of H + and OH - generated in the electrolyte wells. After 30 days of operation, the removal of clopyralid by EKAB is 45% while it reaches 57% in the case of REKAB. Copyright © 2018. Published by Elsevier B.V.

Modelling of Remediation Technologies at the Performance Assessment Level

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

Parton, N.J.; Paksy, A.; Eden, L.

2008-07-01

This paper presents approaches to modelling three different remediation technologies that are designed to support site operators during their assessment of remediation options for the management of radioactively contaminated land on nuclear licensed sites in the UK. The three selected technologies were soil washing, permeable reactive barrier and in-situ stabilisation. The potential exists to represent electrokinetics in the future. These technologies were chosen because it was considered that enough information already existed for site operators to assess mature technologies such as soil dig and disposal and groundwater pump and treat. Using the software code GoldSim, the models have been designedmore » to allow site operators to make both a reasonable scoping level assessment of the viability of treatment and understand the cost-benefits of each technology. For soil washing, a standard soil leaching technique was simulated whereby the soil is separated into fines and oversize particles, and subsequently a chemical reagent is used to strip contamination off the soil. The cost benefit of this technology in terms of capital costs for the plant and materials, operational costs and waste disposal costs can also be assessed. The permeable reactive barrier (PRB) model can represent either a continuous wall or a funnel and gate system. The model simulates the transport of contaminants through the reactive material contained in the PRB. The outputs from the model include concentration of contaminants in the groundwater flow downstream of the PRB, mass of contaminants retained by the PRB, total mass and volume of waste and the various costs associated with the PRB remediation technology. The in-situ stabilisation (ISS) model has the capability to represent remediation by the addition of reagents that immobilise contaminated soil. The model simulates the release of contaminants from the treated soil over time. Performance is evaluated by comparison of the mass of contaminants retained and released to the area outside the treatment zone. Other outputs include amount of spoil generated (to be treated as waste) and the costs associated with the application of the ISS technology. These models are aimed to help users select a technology or technologies that are potentially suitable for a particular site. It is anticipated that they will prompt the user to undertake more detailed assessments to tailor the selected technology to their site specific circumstances and contaminated land conditions. (author)« less

USE OF COAL DRYING TO REDUCE WATER CONSUMED IN PULVERIZED COAL POWER PLANTS

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

Edward Levy; Nenad Sarunac; Harun Bilirgen

2005-04-01

This is the ninth Quarterly Report for this project. The background and technical justification for the project are described, including potential benefits of reducing fuel moisture using power plant waste heat, prior to firing the coal in a pulverized coal boiler. During this last Quarter, comparative analyses were performed for lignite and PRB coals to determine how unit performance varies with coal product moisture. Results are given showing how the coal product moisture level and coal rank affect parameters such as boiler efficiency, station service power needed for fans and pulverizers and net unit heat rate. Results are also givenmore » for the effects of coal drying on cooling tower makeup water and comparisons are made between makeup water savings for various times of the year.« less

Impacts of flare emissions from an ethylene plant shutdown to regional air quality

NASA Astrophysics Data System (ADS)

Wang, Ziyuan; Wang, Sujing; Xu, Qiang; Ho, Thomas

2016-08-01

Critical operations of chemical process industry (CPI) plants such as ethylene plant shutdowns could emit a huge amount of VOCs and NOx, which may result in localized and transient ozone pollution events. In this paper, a general methodology for studying dynamic ozone impacts associated with flare emissions from ethylene plant shutdowns has been developed. This multi-scale simulation study integrates process knowledge of plant shutdown emissions in terms of flow rate and speciation together with regional air-quality modeling to quantitatively investigate the sensitivity of ground-level ozone change due to an ethylene plant shutdown. The study shows the maximum hourly ozone increments can vary significantly by different plant locations and temporal factors including background ozone data and solar radiation intensity. It helps provide a cost-effective air-quality control strategy for industries by choosing the optimal starting time of plant shutdown operations in terms of minimizing the induced ozone impact (reduced from 34.1 ppb to 1.2 ppb in the performed case studies). This study provides valuable technical supports for both CPI and environmental policy makers on cost-effective air-quality controls in the future.

A Novel Gene, OZONE-RESPONSIVE APOPLASTIC PROTEIN1, Enhances Cell Death in Ozone Stress in Rice1

PubMed Central

Ueda, Yoshiaki; Siddique, Shahid; Frei, Michael

2015-01-01

A novel protein, OZONE-RESPONSIVE APOPLASTIC PROTEIN1 (OsORAP1), was characterized, which was previously suggested as a candidate gene underlying OzT9, a quantitative trait locus for ozone stress tolerance in rice (Oryza sativa). The sequence of OsORAP1 was similar to that of ASCORBATE OXIDASE (AO) proteins. It was localized in the apoplast, as shown by transient expression of an OsORAP1/green fluorescent protein fusion construct in Nicotiana benthamiana leaf epidermal and mesophyll cells, but did not possess AO activity, as shown by heterologous expression of OsORAP1 in Arabidopsis (Arabidopsis thaliana) mutants with reduced background AO activity. A knockout rice line of OsORAP1 showed enhanced tolerance to ozone stress (120 nL L−1 average daytime concentration, 20 d), as demonstrated by less formation of leaf visible symptoms (i.e. cell death), less lipid peroxidation, and lower NADPH oxidase activity, indicating reduced active production of reactive oxygen species. In contrast, the effect of ozone on chlorophyll content was not significantly different among the lines. These observations suggested that OsORAP1 specifically induced cell death in ozone stress. Significantly enhanced expression of jasmonic acid-responsive genes in the knockout line implied the involvement of the jasmonic acid pathway in symptom mitigation. Sequence analysis revealed extensive polymorphisms in the promoter region of OsORAP1 between the ozone-susceptible cv Nipponbare and the ozone-tolerant cv Kasalath, the OzT9 donor variety, which could be responsible for the differential regulation of OsORAP1 reported earlier. These pieces of evidence suggested that OsORAP1 enhanced cell death in ozone stress, and its expression levels could explain the effect of a previously reported quantitative trait locus. PMID:26220952

High ozone levels in the northeast of Portugal: Analysis and characterization

NASA Astrophysics Data System (ADS)

Carvalho, A.; Monteiro, A.; Ribeiro, I.; Tchepel, O.; Miranda, A. I.; Borrego, C.; Saavedra, S.; Souto, J. A.; Casares, J. J.

2010-03-01

Each summer period extremely high ozone levels are registered at the rural background station of Lamas d'Olo, located in the Northeast of Portugal. In average, 30% of the total alert threshold registered in Portugal is detected at this site. The main purpose of this study is to characterize the atmospheric conditions that lead to the ozone-rich episodes at this site. Synoptic patterns anomalies and back trajectories cluster analysis were performed, for the period between 2004 and 2007, considering 76 days when ozone maximum hourly concentrations were above 200 μg m -3. The obtained atmospheric anomaly fields suggested that a positive temperature anomaly is visible above the Iberian Peninsula. A strong wind flow pattern from NE is observable in the North of Portugal and Galicia, in Spain. These two features may lead to an enhancement of the photochemical production and to the transport of pollutants from Spain to Portugal. In addition, the 3D mean back trajectories associated to the ozone episode days were analysed. A clustering method has been applied to the obtained back trajectories. Four main clusters of ozone-rich episodes were identified, with different frequencies of occurrence: north-westerly flows (11%); north-easterly flows (45%), southern flow (4%) and westerly flows (40%). Both analyses highlight the NE flow as a dominant pattern over the North of Portugal during summer. The analysis of the ozone concentrations for each selected cluster indicates that this northeast circulation pattern, together with the southern flow, are responsible for the highest ozone peak episodes. This also suggests that long-range transport of atmospheric pollutants is the main contributor to the ozone levels registered at Lamas d'Olo. This is also highlighted by the correlation of the ozone time-series with the meteorological parameters analysed in the frequency domain.

ANALYSIS AND CHARACTERIZATION OF OZONE-RICH EPISODES IN NORTHEAST PORTUGAL

NASA Astrophysics Data System (ADS)

Carvalho, A.; Monteiro, A.; Ribeiro, I.; Tchepel, O.; Miranda, A.; Borrego, C.; Saavedra, S.; Souto, J. A.; Casares, J. J.

2009-12-01

Each summer period extremely high ozone levels are registered at the rural background station of Lamas d’Olo, located in the Northeast of Portugal. In average, 30% of the total alert threshold registered in Portugal is detected at this site. The main purpose of this study is to characterize the atmospheric conditions that lead to the ozone-rich episodes. Synoptic patterns anomalies and back trajectories cluster analysis were performed for a period of 76 days where ozone maximum concentrations were above 200 µg.m-3. This analysis was performed for the period between 2004 and 2007. The obtained anomaly fields suggested that a positive temperature anomaly is visible above the Iberian Peninsula. In addition, a strong wind flow pattern from NE is visible in the North of Portugal and Galicia, in Spain. These two features may lead to an enhancement of the photochemical production and to the transport of pollutants from Spain to Portugal. In addition, the 3D mean back trajectories associated to the ozone episode days were analysed. A clustering method has been applied to the obtained back trajectories. Four main clusters of ozone-rich episodes were identified, with different frequencies of occurrence: north-westerly flows (11%); north-easterly flows (45%), southern flow (4%) and westerly flows (40%). Both analyses highlight the NE flow as a dominant pattern over the North of Portugal. The analysis of the ozone concentrations for each selected cluster indicates that this northeast circulation pattern, together with the southern flow, is responsible for the highest ozone peak episodes. This also suggests that long-range transport of atmospheric pollutants may be the main contributor to the ozone levels registered at Lamas d’Olo. This is also highlighted by the correlation of the ozone time series with the meteorological parameters analysed in the frequency domain.

Vertical Distribution of Non-Methane Hydrocarbons During Winter Ozone Production Events in the Uintah Basin

NASA Astrophysics Data System (ADS)

Stephens, C. R.; Helmig, D.; Evans, J.; Hueber, J.; Park, J.; Boylan, P.

2013-12-01

Emissions of non-methane hydrocarbons (NMHC) are primarily linked to anthropogenic fossil fuel activities, such as oil and natural gas extraction and distribution, and are important tropospheric ozone precursors. The Uintah Basin, Utah, is a region of heavy oil and natural gas development where high winter-time ozone production events have been observed during strong inversions when there is snow cover present. In the winters of 2012 and 2013, we conducted measurements of methane and NMHC during the Uintah Basin Winter Ozone Study. NMHC were monitored along a vertical gradient up to 150 m using a flux tower and tethered balloon. In 2013, measurements of NMHC were also conducted from within the snowpack. In 2012, no high ozone events were observed. In contrast, during the 2013 study, several periods of high ozone occurred concurrently with strong increases in ambient NMHC. Here, we present vertical profile measurements of C2-C5 alkanes, benzene and toluene comparing 2012 and 2013. Data from 2013 show strong vertical gradients with build-up of NMHC and ozone near the surface during inversion events, with wash out of both ozone and ozone precursors during low pressure front passage from the west. The NOAA/INSTAAR global flask network provides a useful comparison for expected regional background values of NMHC, and we find up to a 570-fold enhancement in Uintah, providing evidence for the importance of local emissions sources. Investigation of NMHC ratios reveals distinctly different values in the ambient air and within the snowpack, suggesting active radical chemistry occurring in the snow. Analysis of butane and pentane isomer ratios points towards the presence of chlorine radicals, indicating that the snow may serve as a reactive chlorine reservoir that may enhance ozone production chemistry.

Energetic electrons and their effects on upper stratospheric and mesospheric ozone in May 1992

NASA Astrophysics Data System (ADS)

Pesnell, W. Dean; Goldberg, Richard A.; Chenette, D. L.; Gaines, E. E.; Jackman, Charles H.

The increased fluxes of precipitating energetic electrons (E>1 MeV) during highly relativistic electron events (HREs) produce ion concentrations in the upper stratosphere and lower mesosphere that exceed the background concentrations. Coupled ion-neutral chemistry models predict that this increased ionization should drive HOχ reactions and deplete mesospheric ozone by up to roughly 25%. As HREs become more intense and frequent during the declining phase of the solar cycle, it was also predicted that mesospheric ozone would show a solar cycle modulation as a result of these events. To calibrate the effect HREs have on mesospheric ozone, we have studied the May 1992 HRE with several instruments on the UARS. Electron fluxes measured with HEPS give the duration and spatial coverage of the HRE. Ozone data from MLS, CLAES, and HRDI were examined for the chemical signature of the HRE, ozone depletions within the magnetic L-shell limits of 3≤L<4. Using the multiple viewing angles of HRDI, we can compare mesospheric ozone at similar local solar times before, during, and after the HRE. This removes some of the ambiguity caused by progressive sampling of the diurnal cycle over a yaw cycle of the satellite. Although we analyzed one of the most intense HREs in the UARS database, we did not find HRE-induced changes in the ozone mixing ratio between altitudes of 55-75 km. Detecting a long-term trend in the ozone driven by precipitating electrons appears to require a substantial increase in the signal-to-noise ratio of the satellite measurements.

Chemical processes related to net ozone tendencies in the free troposphere

NASA Astrophysics Data System (ADS)

Bozem, Heiko; Butler, Tim M.; Lawrence, Mark G.; Harder, Hartwig; Martinez, Monica; Kubistin, Dagmar; Lelieveld, Jos; Fischer, Horst

2017-09-01

Ozone (O3) is an important atmospheric oxidant, a greenhouse gas, and a hazard to human health and agriculture. Here we describe airborne in situ measurements and model simulations of O3 and its precursors during tropical and extratropical field campaigns over South America and Europe, respectively. Using the measurements, net ozone formation/destruction tendencies are calculated and compared to 3-D chemistry-transport model simulations. In general, observation-based net ozone tendencies are positive in the continental boundary layer and the upper troposphere at altitudes above ˜ 6 km in both environments. On the other hand, in the marine boundary layer and the middle troposphere, from the top of the boundary layer to about 6-8 km altitude, net O3 destruction prevails. The ozone tendencies are controlled by ambient concentrations of nitrogen oxides (NOx). In regions with net ozone destruction the available NOx is below the threshold value at which production and destruction of O3 balance. While threshold NO values increase with altitude, in the upper troposphere NOx concentrations are generally higher due to the integral effect of convective precursor transport from the boundary layer, downward transport from the stratosphere and NOx produced by lightning. Two case studies indicate that in fresh convective outflow of electrified thunderstorms net ozone production is enhanced by a factor 5-6 compared to the undisturbed upper tropospheric background. The chemistry-transport model MATCH-MPIC generally reproduces the pattern of observation-based net ozone tendencies but mostly underestimates the magnitude of the net tendency (for both net ozone production and destruction).

Acute effect of ozone exposure on daily mortality in seven cities of Jiangsu Province, China: No clear evidence for threshold

PubMed Central

Chen, Kai; Zhou, Lian; Chen, Xiaodong; Bi, Jun; Kinney, Patrick L.

2017-01-01

Background Few multicity studies have addressed the health effects of ozone in China due to the scarcity of ozone monitoring data. A critical scientific and policy-relevant question is whether a threshold exists in the ozone-mortality relationship. Methods Using a generalized additive model and a univariate random-effects meta-analysis, this research evaluated the relationship between short-term ozone exposure and daily total mortality in seven cities of Jiangsu Province, China during 2013–2014. Spline, subset, and threshold models were applied to further evaluate whether a safe threshold level exists. Results This study found strong evidence that short-term ozone exposure is significantly associated with premature total mortality. A 10 μg/m3 increase in the average of the current and previous days’ maximum 8-h average ozone concentration was associated with a 0.55% (95% posterior interval: 0.34%, 0.76%) increase of total mortality. This finding is robust when considering the confounding effect of PM2.5, PM10, NO2, and SO2. No consistent evidence was found for a threshold in the ozone-mortality concentration-response relationship down to concentrations well below the current Chinese Ambient Air Quality Standard (CAAQS) level 2 standard (160 μg/m3). Conclusions Our findings suggest that ozone concentrations below the current CAAQS level 2 standard could still induce increased mortality risks in Jiangsu Province, China. Continuous air pollution control measures could yield important health benefits in Jiangsu Province, China, even in cities that meet the current CAAQS level 2 standard. PMID:28231551

Ambient ozone and incident diabetes: A prospective analysis in a large cohort of African American women

PubMed Central

Jerrett, Michael; Brook, Robert; White, Laura F.; Burnett, Richard T.; Yu, Jeffrey; Su, Jason; Seto, Edmund; Marshall, Julian; Palmer, Julie R.; Rosenberg, Lynn; Coogan, Patricia F.

2017-01-01

Background Ozone is a ubiquitous air pollutant with increasing concentrations in many populous regions. Toxicological studies show that ozone can cause oxidative stress and increase insulin resistance. These pathways may contribute to metabolic changes and diabetes formation. In this paper, we investigate the association between ozone and incident type 2 diabetes in a large cohort of African American women. Methods We used Cox proportional hazards models to calculate hazard ratios (HRs) for incident type 2 diabetes associated with exposure to ozone in a cohort of 45,231 African American women living in 56 metropolitan areas across the United States. Ozone levels were estimated using the U.S. EPA Models-3/Community Multiscale Air Quality (CMAQ) predictions fused with ground measurements at a resolution of 12 km for the years 2007–2008. Results The HR per interquartile range increment of 6.7 ppb of ozone was 1.18 (95% CI 1.04–1.34) for incident diabetes in adjusted models. This association was unaltered in models that controlled for fine particulate matter with diameter <2.5 μ (PM2.5). Associations were modified by nitrogen dioxide (NO2) levels, such that HRs for ozone levels were larger in areas of lower NO2. Conclusions Our results provide initial evidence of a positive association between in O3 and incident diabetes African American women. Given the ubiquity of ozone exposure and the importance of diabetes on quality of life and survival, these results may have important implications for the protection of public health. PMID:28153529

High Concentrations of Ozone Air Pollution on Mount Everest: Health Implications for Sherpa Communities and Mountaineers.

PubMed

Semple, John L; Moore, G W Kent; Koutrakis, Petros; Wolfson, Jack M; Cristofanelli, Paolo; Bonasoni, Paolo

2016-12-01

Semple, John L., G.W. Kent Moore, Petros Koutrakis, Jack M. Wolfson, Paolo Cristofanelli, and Paolo Bonasoni. High concentrations of ozone air pollution on Mount Everest: health implications for Sherpa communities and mountaineers. High Alt Med Biol. 17:365-369, 2016.-Introduction: Populations in remote mountain regions are increasingly vulnerable to multiple climate mechanisms that influence levels of air pollution. Few studies have reported on climate-sensitive health outcomes unique to high altitude ecosystems. In this study, we report on the discovery of high-surface ozone concentrations and the potential impact on health outcomes on Mount Everest and the high Himalaya. Surface ozone measurements were collected during ascending transects in the Mount Everest region of Nepal with passive nitrite-coated Ogawa filter samplers to obtain 8-hour personal exposures (2860-5364 m asl). In addition, the Nepal Climate Observatory-Pyramid, a GAW-WMO Global Station sited in the Khumbu Valley (5079 m asl), collected ozone mixing ratios with photometric gas analyzer. Surface ozone measurements increased with altitude with concentrations that exceed 100 ppb (8-hour exposure). Highest values were during the spring season and the result of diverse contributions: hemispheric background values, the descent of ozone-rich stratospheric air, and the transport of tropospheric pollutants occurring at different spatial scales. Multiple climate factors, including descending stratospheric ozone and imported anthropogenic air masses from the Indo-Gangetic Plain, contribute to ambient ozone exposure levels in the vicinity of Mount Everest that are similar to if not higher than those reported in industrialized cities.

Effect of Ozone on Intestinal Epithelial Homeostasis in a Rat Model

PubMed Central

Sukhotnik, Igor; Starikov, Alona; Coran, Arnold G.; Pollak, Yulia; Sohotnik, Rima; Shaoul, Ron

2015-01-01

Background: The positive effects of ozone therapy have been described in many gastrointestinal disorders. The mechanisms of this positive effect of ozone therapy are poorly understood. The purpose of the present study was to investigate whether the use of ozone may potentiate the gut intestinal mucosal homeostasis in a rat model. Methods: Adult rats weighing 250–280 g were randomly assigned to one of three experimental groups of 8 rats each: 1) Control rats were given 2 mL of water by gavage and intraperitoneally (IP) for 5 days; 2) O3-PO rats were treated with 2 mL of ozone/oxygen mixture by gavage and 2 mL of water IP for 5 days; 3) O3-IP rats were treated with 2 mL of water by gavage and 2 mL of ozone/oxygen mixture IP for 5 days. Rats were sacrificed on day 6. Bowel and mucosal weight, mucosal DNA and protein, villus height and crypt depth, and cell proliferation and apoptosis were evaluated following sacrifice. Results: The group of O3-IP rats demonstrated a greater jejunal and ileal villus height and crypt depth, a greater enterocyte proliferation index in jejunum, and lower enterocyte apoptosis in ileum compared to control animals. Oral administration of the ozone/oxygen mixture resulted in a less significant effect on cell turnover. Conclusions: Treatment with an ozone/oxygen mixture stimulates intestinal cell turnover in a rat model. Intraperitoneal administration of ozone resulted in a more significant intestinal trophic effect than oral administration. PMID:25717388

Use of Ozone to Treat Ileostomy Dermatitis in an Experimental Rat Model

PubMed Central

Biçer, Şenol; Sayar, İlyas; Gürsul, Cebrail; Işık, Arda; Aydın, Merve; Peker, Kemal; Demiryilmaz, İsmail

2016-01-01

Background Dermatitis associated with ileostomy is an important problem that affects many people, especially children. The aim of this study was to investigate the therapeutic effects of ozone on dermatitis due to ileostomy, and to develop an alternative treatment option. Material/Methods A total of 28 rats were divided into 4 groups: control, ileostomy, ozone, and zinc oxide. Ileostomy was performed in all rats except the control group. After a 1-week waiting time, the ozone group was administered ozone therapy and the zinc oxide group was administered zinc oxide cream locally once a day for a total of 7 days. All rats were sacrificed at the end of this period. The efficacy of treatment was examined by biochemical, histopathological, and immunohistochemical parameters. The levels of malondialdehyde (MDA), total glutathione (tGSH), total antioxidant capacity (TAC), and total oxidant status (TOS) were measured from tissue. Vascular endothelial growth factor (VEGF) and proliferating cell nuclear antigen (PCNA) were examined immunohistochemically. Results Dermatitis occurred pathologically in all rats that underwent ileostomy surgery. The lowest dermatitis score was in the ozone treatment group (p<0.05). Ileostomy dermatitis caused increased levels of MDA and TOS. Ozone treatment resulted in reduced MDA and TOS levels, while the levels of tGSH and TAC were increased (p<0.05). Both VEGF and PCNA immunostaining were augmented in the ozone treatment group (p<0.05). Conclusions Local ozone application may be a good alternative compared to the conventional treatment methods for the prevention of skin lesions that develop after ileostomy. PMID:26947591

Chronic Exposure to Ambient Ozone and Asthma Hospital Admissions among Children

PubMed Central

Lin, Shao; Liu, Xiu; Le, Linh H.; Hwang, Syni-An

2008-01-01

Background The association between chronic exposure to air pollution and adverse health outcomes has not been well studied. Objective This project investigated the impact of chronic exposure to high ozone levels on childhood asthma admissions in New York State. Methods We followed a birth cohort born in New York State during 1995–1999 to first asthma admission or until 31 December 2000. We identified births and asthma admissions through the New York State Integrated Child Health Information System and linked these data with ambient ozone data (8-hr maximum) from the New York State Department of Environmental Conservation. We defined chronic ozone exposure using three indicators: mean concentration during the follow-up period, mean concentration during the ozone season, and proportion of follow-up days with ozone levels > 70 ppb. We performed logistic regression analysis to adjust for child’s age, sex, birth weight, and gestational age; maternal race/ethnicity, age, education, insurance status, smoking during pregnancy, and poverty level; and geographic region, temperature, and copollutants. Results Asthma admissions were significantly associated with increased ozone levels for all chronic exposure indicators (odds ratios, 1.16–1.68), with a positive dose–response relationship. We found stronger associations among younger children, low sociodemographic groups, and New York City residents as effect modifiers. Conclusion Chronic exposure to ambient ozone may increase the risk of asthma admissions among children. Younger children and those in low socioeconomic groups have a greater risk of asthma than do other children at the same ozone level. PMID:19079727

Stratospheric Ozone Response in Experiments G3 and G4 of the Geoengineering Model Intercomparison Project (GeoMIP)

NASA Technical Reports Server (NTRS)

Pitari, Giovanni; Aquila, Valentina; Kravitz, Ben; Watanabe, Shingo; Tilmes, Simone; Mancini, Eva; DeLuca, Natalia; DiGenova, Glauco

2013-01-01

Geoengineering with stratospheric sulfate aerosols has been proposed as a means of temporarily cooling the planet, alleviating some of the side effects of anthropogenic CO2 emissions. However, one of the known side effects of stratospheric injections of sulfate aerosols is a decrease in stratospheric ozone. Here we show results from two general circulation models and two coupled chemistry climate models that have simulated stratospheric sulfate aerosol geoengineering as part of the Geoengineering Model Intercomparison Project (GeoMIP). Changes in photolysis rates and upwelling of ozone-poor air in the tropics reduce stratospheric ozone, suppression of the NOx cycle increases stratospheric ozone, and an increase in available surfaces for heterogeneous chemistry modulates reductions in ozone. On average, the models show a factor 20-40 increase of the sulfate aerosol surface area density (SAD) at 50 hPa in the tropics with respect to unperturbed background conditions and a factor 3-10 increase at mid-high latitudes. The net effect for a tropical injection rate of 5 Tg SO2 per year is a decrease in globally averaged ozone by 1.1-2.1 DU in the years 2040-2050 for three models which include heterogeneous chemistry on the sulfate aerosol surfaces. GISS-E2-R, a fully coupled general circulation model, performed simulations with no heterogeneous chemistry and a smaller aerosol size; it showed a decrease in ozone by 9.7 DU. After the year 2050, suppression of the NOx cycle becomes more important than destruction of ozone by ClOx, causing an increase in total stratospheric ozone. Contribution of ozone changes in this experiment to radiative forcing is 0.23 W m-2 in GISS-E2-R and less than 0.1 W m-2 in the other three models. Polar ozone depletion, due to enhanced formation of both sulfate aerosol SAD and polar stratospheric clouds, results in an average 5 percent increase in calculated surface UV-B.

Measurements of in situ chemical ozone (oxidant) production rates

NASA Astrophysics Data System (ADS)

Huang, Hao; Faloon, Kate; Najera, Juan; Bloss, William

2013-04-01

Tropospheric ozone is a major air pollutant, harmful to human health, agricultural crops and vegetation, the main precursor to the atmospheric oxidants which initiate the degradation of most reactive gases emitted to the atmosphere, and an important greenhouse gas in its own right. The capacity to understand and predict tropospheric ozone levels is a key goal for atmospheric science - but one which is challenging, as ozone is formed in the atmosphere from the complex oxidation of VOCs in the presence of NOx and sunlight, on a timescale such that in situ chemical processes, deposition and transport all affect ozone levels. Known uncertainties in emissions, chemistry, dynamics and deposition affect the accuracy of predictions of current and future ozone levels, and hinder development of optimal air quality policies to mitigate against ozone exposure. Recently new approaches to directly measure the local chemical ozone production rate, bypassing the many uncertainties in emissions and chemical schemes, have been developed (Cazorla & Brune, AMT 2010). Here, we describe the development of an analogous Ozone Production Rate (OPR) approach: Air is sampled into parallel reactors, within which ozone formation either occurs as in the ambient atmosphere, or is suppressed. Comparisons of ozone levels exiting a pair of such reactors determines the net chemical oxidant production rate, after correction for perturbation of the NOx-O3 photochemical steady state, and when operated under conditions such that wall effects are minimised. We report preliminary measurements of local chemical ozone production made during the UK NERC ClearfLo (Clean Air for London) campaign at an urban background location in London in January and July 2012. The OPR system was used to measure the local chemical oxidant formation rate, which is compared with observed trends in O3 and NOx and the prevailing meteorology, and with the predictions of a detailed zero-dimensional atmospheric chemistry model, constrained by observations of long-lived species.

Physiological and genotype-specific factors associated with grain quality changes in rice exposed to high ozone.

PubMed

Jing, Liquan; Dombinov, Vitalij; Shen, Shibo; Wu, Yanzhen; Yang, Lianxin; Wang, Yunxia; Frei, Michael

2016-03-01

Rising tropospheric ozone concentrations in Asia affect the yield and quality of rice. This study investigated ozone-induced changes in rice grain quality in contrasting rice genotypes, and explored the associated physiological processes during the reproductive growth phase. The ozone sensitive variety Nipponbare and a breeding line (L81) containing two tolerance QTLs in Nipponbare background were exposed to 100 ppb ozone (8 h per day) or control conditions throughout their growth. Ozone affected grain chalkiness and protein concentration and composition. The percentage of chalky grains was significantly increased in Nipponbare but not in L81. Physiological measurements suggested that grain chalkiness was associated with a drop in foliar carbohydrate and nitrogen levels during grain filling, which was less pronounced in the tolerant L81. Grain total protein concentration was significantly increased in the ozone treatment, although the albumin fraction (water soluble protein) decreased. The increase in protein was more pronounced in L81, due to increases in the glutelin fraction in this genotype. Amino acids responded differently to the ozone treatment. Three essential amino acids (leucine, methionine and threonine) showed significant increases, while seven showed significant treatment by genotype interactions, mostly due to more positive responses in L81. The trend of increased grain protein was in contrast to foliar nitrogen levels, which were negatively affected by ozone. A negative correlation between grain protein and foliar nitrogen in ozone stress indicated that higher grain protein cannot be explained by a concentration effect in all tissues due to lower biomass production. Rather, ozone exposure affected the nitrogen distribution, as indicated by altered foliar activity of the enzymes involved in nitrogen metabolism, such as glutamine synthetase and glutamine-2-oxoglutarate aminotransferase. Our results demonstrate differential responses of grain quality to ozone due to the presence of tolerance QTL, and partly explain the underlying physiological processes. Copyright © 2016 Elsevier Ltd. All rights reserved.

Ozone Effects on the Ultrastructure of Peatland Plants: Sphagnum Mosses, Vaccinium oxycoccus, Andromeda polifolia and Eriophorum vaginatum

PubMed Central

RINNAN, RIIKKA; HOLOPAINEN, TOINI

2004-01-01

• Background and Aims Ozone effects on peatland vegetation are poorly understood. Since stress responses are often first visible in cell ultrastructure, electron microscopy was used to assess the sensitivity of common peatland plants to elevated ozone concentrations. • Methods Three moss species (Sphagnum angustifolium, S. magellanicum and S. papillosum), a graminoid (Eriophorum vaginatum) and two dwarf shrubs (Vaccinium oxycoccus and Andromeda polifolia), all growing within an intact canopy on peat monoliths, were exposed to a concentration of 0, 50, 100 or 150 ppb ozone in two separate growth chamber experiments simulating either summer or autumn conditions in central Finland. After a 4- or 5-week-long exposure, samples were photographed in a transmission electron microscope and analysed quantitatively using image processing software. • Key Results In the chlorophyllose cells of the Sphagnum moss leaves from the capitulum, ozone exposure led to a decrease in chloroplast area and in granum stack thickness and various changes in plastoglobuli and cell wall thickness, depending on the species and the experiment. In E. vaginatum, ozone exposure significantly reduced chloroplast cross-sectional areas and the amount of starch, whereas there were no clear changes in the plastoglobuli. In the dwarf shrubs, ozone induced thickening of the cell wall and an increase in the size of plastoglobuli under summer conditions. In contrast, under autumn conditions the cell wall thickness remained unchanged but ozone exposure led to a transient increase in the chloroplast and starch areas, and in the number and size of plastoglobuli. • Conclusions Ozone responses in the Sphagnum mosses were comparable to typical ozone stress symptoms of higher plants, and indicated sensitivity especially in S. angustifolium. The responses in the dwarf shrubs suggest stimulation of photosynthesis by low ozone concentrations and ozone sensitivity only under cool autumn conditions. PMID:15333464

The impact of high altitude aircraft on the ozone layer in the stratosphere

NASA Technical Reports Server (NTRS)

Tie, Xue XI; Brasseur, Guy; Lin, Xing; Friedlingstein, P.; Granier, Claire; Rasch, Philip

1994-01-01

The paper discusses the potential effects on the ozone layer of gases released by the engines of proposed high altitude supersonic aircraft. The major problem arises from the emissions of nitrogen oxides which have the potential to destroy significant quantities of ozone in the stratosphere. The magnitude of the perturbation is highly dependent on the cruise altitude of the aircraft. Furthermore, the depletion of ozone is substantially reduced when heterogeneous conversion of nitrogen oxides into nitric acid on sulfate aerosol particles is taken into account in the calculation. The sensitivity of the aerosol load on stratospheric ozone is investigated. First, the model indicates that the aerosol load induced by the SO2 released by aircraft is increased by about 10-20% above the background aerosols at mid-high latitude of the Northern Hemisphere at 15 km for the NASA emission scenario A (the NASA emission scenarios are explained in Tables I to III). This increase in aerosol has small effects on stratospheric ozone. Second, when the aerosol load is increased following a volcanic eruption similar to the eruption of El Chichon (Mexico, April 1982), the ozone column in spring increases by as much as 9% in response to the injection of NOx from the aircraft with the NASA emission scenario A. Finally, the modeled suggests that significant ozone depletion could result from the formation of additional polar stratospheric clouds produced by the injection of H2O and HNO3 by the aircraft engines.

High Resolution Numerical Simulations and Diagnostic Studies Atmospheric Transport During TRACE-A

NASA Technical Reports Server (NTRS)

Krishnamurti, T. N.; Fuelberg, Henry

1995-01-01

The enclosed publications constitute our final report. These are publications completed in referred journals. The completed work includes: Meteorological conditions associated with vertical distributions of aerosols off the west coast of Africa. TRACE-A trajectory intercomparison 2. Isentropic and kinematic methods. Chemical characteristics of tropospheric air over the tropical South Atlantic Ocean: Relationship to trajectory history. Passive Tracer Transport Relevant to the TRACE-A Experiment. The meteorological environment of the tropospheric ozone maximum over the tropical south Atlantic Ocean. : Influence of a middle-latitude cyclone on tropospheric ozone distributions during a period of TRACE-A. All of this work provided the meteorological background for the Transport of Atmospheric Chemistry near the Equator (TRACE-A) project sponsored by Dr,, Joe McNeal of NASA. Our principal findings are that bio-mass burning sources from Africa and South America did contribute to the accumulation of tropospheric ozone over the tropical Atlantic Ocean. Other findings relate to circulations, advections of Ozone and other plausible sources for the TOMS based ozone maximum over the Atlantic Ocean.

Aromatic volatile organic compounds and their role in ground-level ozone formation in Russia

NASA Astrophysics Data System (ADS)

Berezina, E. V.; Moiseenko, K. B.; Skorokhod, A. I.; Elansky, N. F.; Belikov, I. B.

2017-05-01

This paper reports proton mass spectrometry data on aromatic volatile organic compounds (VOCs) (benzene, toluene, phenol, styrene, xylene, and propylbenzene) obtained in different Russian regions along the Trans-Siberian Railway from Moscow to Vladivostok, based on expedition data retrieved using the TRO-ICA-12 mobile laboratory in the summer of 2008. The contribution of aromatic VOCs to ozone formation in the cities and regions along the measurement route has been estimated quantitatively. The greatest contribution of aromatic VOCs to ozone formation is characteristic of large cities along the Trans-Siberian Railway (up to 7.5 ppbv O3) specified by the highest concentrations of aromatic VOCs (1-1.7 ppbv) and nitrogen oxides (>20 ppbv). The results obtained are indicative of a considerable contribution (30-50%) of anthropogenic emissions of VOCs to photochemical ozone generation in the large cities along the Trans-Siberian Railway in hot and dry weather against the background of a powerful natural factor such as isoprene emissions controlling the regional balance of ground-level ozone in warm seasons.

Contribution of ozone to airborne aldehyde formation in Paris homes.

PubMed

Rancière, Fanny; Dassonville, Claire; Roda, Célina; Laurent, Anne-Marie; Le Moullec, Yvon; Momas, Isabelle

2011-09-15

Indoor aldehydes may result from ozone-initiated chemistry, mainly documented by experimental studies. As part of an environmental investigation included in the PARIS birth cohort, the aim of this study was to examine ozone contribution to airborne aldehyde formation in Paris homes. Formaldehyde, acetaldehyde and hexaldehyde levels, as well as styrene, nitrogen dioxide and nicotine concentrations, comfort parameters and carbon dioxide levels, were measured twice during the first year of life of the babies. Ambient ozone concentrations were collected from the closest background station of the regional air monitoring network. Traffic-related nitrogen oxide concentrations in front of the dwellings were estimated by an air pollution dispersion model. Home characteristics and families' way of life were described by questionnaires. Stepwise multiple linear regression models were used to link aldehyde levels with ambient ozone concentrations and a few aldehyde precursors involved in oxidation reactions, adjusting for other indoor aldehyde sources, comfort parameters and traffic-related nitrogen oxides. A 4 and 11% increase in formaldehyde and hexaldehyde levels was pointed out when 8-hour ozone concentrations increased by 20 μg/m(3). The influence of potential precursors such as indoor styrene level and frequent use of air fresheners, containing unsaturated volatile organic compounds as terpenes, was also found. Thus, our results suggest that ambient ozone can significantly impact indoor air quality, especially with regard to formaldehyde and hexaldehyde levels. Copyright © 2011 Elsevier B.V. All rights reserved.

The Effect of Solar Proton Events on Ozone and Other Constituents

NASA Technical Reports Server (NTRS)

Jackman, Charles H.; McPeters, Richard D.; Bhartia, P. K. (Technical Monitor)

2000-01-01

Solar proton events (SPEs) can cause changes in constituents in the Earth's middle atmosphere. The highly energetic protons cause ionizations, excitations, dissociations, and dissociative ionizations of the background constituents. Complicated ion chemistry leads to HO(x) production and dissociation of N2 leads to NO(y) production. Both the HO(x) and NO(y) increases can result in changes to ozone in the stratosphere and mesosphere. The HO(x) increases lead to short-lived ozone decreases in the mesosphere and upper stratosphere due to the short lifetimes of the HO(x) constituents. The NO(y) increases lead to long-lived stratospheric ozone changes because of the long lifetime of NO(y) constituents in this region. The NO(y) induced ozone changes are generally decreases, however, the NO(y) constituents can interfere with chlorine and bromine radicals in the lowest part of the stratosphere and cause ozone increases. Temperature changes have been predicted to occur as a result of the larger SPEs. Eleven SPEs have caused measurable atmospheric variations since 1969. Neutral wind variations were measured shortly after the July 1982 and April 1984 SPEs. The recent July 2000 SPE caused NO(x) increases that lasted for two months past the event. The two periods of largest SPEs (August 1972 and October 1989) caused ozone decreases that lasted for several weeks past the events.

Remediation potential of mulch for removing lead.

PubMed

Jang, A; Bishop, P L

2012-01-01

Hardwood bark mulch has good physicochemical properties for the adsorption of lead (Pb(II)). Batch tests were conducted to obtain the sorption coefficient of Pb(II) in mulch. The results of the Freundlich model were not in as good agreement as for the case of the Langmuir model. In addition, a laboratory-scale mulch permeable reactive barrier (PRB) system was designed for the treatment of Pb(II)-contaminated groundwater. The mulch PRB system, using a mulch layer, can potentially be used in the subsurface for cost-effective and in situ transformation of the Pb(II) into environmentally acceptable forms. From the Pb(II) breakthrough curve, the mulch becomes saturated more quickly at higher flow rates.

Measurement and Modeling of Volatile Particle Emissions from Military Aircraft

DTIC Science & Technology

2011-10-01

cruise load (expt #4). (a,d) CO2, ozone , and chamber temperature, (b,e) Concentrations of toluene and acetaldehyde (note scale is not to zero for left...background air containing ozone . NO oxidizes to HNO2 while NO2 oxidizes to HNO3. HNO3 and HNO2 may contribute to 6 volatile PM, but their...contribution is currently not well understood. Under the relatively warm conditions of the lower troposphere relevant to the PM2.5 NAAQS, HNO3 condenses into

Investigations into regional ozone concentrations in the Bakken-Williston Basin using ARTEMIS, a mobile measurment platform.

NASA Astrophysics Data System (ADS)

Donohoue, D.; Jumes, D.; Jaglowski, J.

2017-12-01

During a campaign launched in August 2015, concentrations of ozone, nitrogen oxides, and weather conditions were measured throughout the Bakken-Williston Basin. The data was collected using a new in-situ monitoring system ARTEMIS (Atmospheric Research Trailer for Environmental Monitoring and Interactive Science). ARTEMIS is a self-sustaining trailer equipped with a solar panel and four 80 Ah batteries, which can power an instrumental suite. It provided a temporary sampling station which could be erected in five minutes. During this campaign we collected data for one hour at sites throughout North Dakota and Montana. Preliminary results from this data suggests that near active mining or methane flaring regions ozone concentrations appear to be elevated from the background.

Novel Roles for Notch3 and Notch4 Receptors in Gene Expression and Susceptibility to Ozone-Induced Lung Inflammation in Mice

PubMed Central

McCaw, Zachary; Gladwell, Wesley; Trivedi, Shweta; Bushel, Pierre R.; Kleeberger, Steven R.

2015-01-01

Background Ozone is a highly toxic air pollutant and global health concern. Mechanisms of genetic susceptibility to ozone-induced lung inflammation are not completely understood. We hypothesized that Notch3 and Notch4 are important determinants of susceptibility to ozone-induced lung inflammation. Methods Wild-type (WT), Notch3 (Notch3–/–), and Notch4 (Notch4–/–) knockout mice were exposed to ozone (0.3 ppm) or filtered air for 6–72 hr. Results Relative to air-exposed controls, ozone increased bronchoalveolar lavage fluid (BALF) protein, a marker of lung permeability, in all genotypes, but significantly greater concentrations were found in Notch4–/– compared with WT and Notch3–/– mice. Significantly greater mean numbers of BALF neutrophils were found in Notch3–/– and Notch4–/– mice compared with WT mice after ozone exposure. Expression of whole lung Tnf was significantly increased after ozone in Notch3–/– and Notch4–/– mice, and was significantly greater in Notch3–/– compared with WT mice. Statistical analyses of the transcriptome identified differentially expressed gene networks between WT and knockout mice basally and after ozone, and included Trim30, a member of the inflammasome pathway, and Traf6, an inflammatory signaling member. Conclusions These novel findings are consistent with Notch3 and Notch4 as susceptibility genes for ozone-induced lung injury, and suggest that Notch receptors protect against innate immune inflammation. Citation Verhein KC, McCaw Z, Gladwell W, Trivedi S, Bushel PR, Kleeberger SR. 2015. Novel roles for Notch3 and Notch4 receptors in gene expression and susceptibility to ozone-induced lung inflammation in mice. Environ Health Perspect 123:799–805; http://dx.doi.org/10.1289/ehp.1408852 PMID:25658374

The Impact of Meteorology on Ozone Levels in the Lake Tahoe Basin

NASA Astrophysics Data System (ADS)

Theiss, Sandra

The Lake Tahoe Basin is located on the California-Nevada border and occasionally experiences elevated levels of ozone exceeding the 70 ppb California Air Resources Board (CARB) ambient air quality standard (8-hour average). Previous studies indicate that both the local generation of ozone in the Basin and long-range transport from out-of-Basin sources are important in contributing to ozone exceedances, but little is known about the impact of meteorology on the distribution of ozone source regions. In order to develop a better understanding of the factors affecting ozone levels and sources in the Lake Tahoe Basin, this study combines observational data from a 2010 and 2012 summer field campaigns, HYSPLIT back trajectories, and WRF model output to examine the meteorological influences of ozone transport in the topographically complex Lake Tahoe Basin. Findings from the field work portions of this study include enhanced background ozone levels at higher elevations, the local circulation pattern of lake breezes occurring at Lake level sites, and an indication that ozone precursors are coming off the Lake. Our analysis also showed that if transport of ozone does occur, it is more likely to come from the San Joaquin Valley to the south rather than originate in the large cities to the west, such as Sacramento and San Francisco. Analysis of modeled PBL schemes as compared with observational data showed that the ACM2 PBL scheme best represented the geographical domain. The ACM2 PBL scheme was then used to show wind circulation patterns in the Lake Tahoe Basin and concluded that there is decent vertical mixing over the Basin and no indication of ozone transport from the west however some indication of transport from the east. Overall this study concludes that transport from the west is less significant than transport from the south and east, and that transport only influences ozone values at higher elevations. Within the Basin itself (at lower elevations), local factors including mixing depth, rising or sinking air, and lake/land breeze circulations are more significant in influencing ozone values.

Effect of Acute Ozone Induced Airway Inflammation on Human Sympathetic Nerve Traffic: A Randomized, Placebo Controlled, Crossover Study

PubMed Central

Tank, Jens; Biller, Heike; Heusser, Karsten; Holz, Olaf; Diedrich, André; Framke, Theodor; Koch, Armin; Grosshennig, Anika; Koch, Wolfgang; Krug, Norbert; Jordan, Jens; Hohlfeld, Jens M.

2011-01-01

Background Ozone concentrations in ambient air are related to cardiopulmonary perturbations in the aging population. Increased central sympathetic nerve activity induced by local airway inflammation may be one possible mechanism. Methodology/Principal Findings To elucidate this issue further, we performed a randomized, double-blind, cross-over study, including 14 healthy subjects (3 females, age 22–47 years), who underwent a 3 h exposure with intermittent exercise to either ozone (250 ppb) or clean air. Induced sputum was collected 3 h after exposure. Nineteen to 22 hours after exposure, we recorded ECG, finger blood pressure, brachial blood pressure, respiration, cardiac output, and muscle sympathetic nerve activity (MSNA) at rest, during deep breathing, maximum-inspiratory breath hold, and a Valsalva maneuver. While the ozone exposure induced the expected airway inflammation, as indicated by a significant increase in sputum neutrophils, we did not detect a significant estimated treatment effect adjusted for period on cardiovascular measurements. Resting heart rate (clean air: 59±2, ozone 60±2 bpm), blood pressure (clean air: 121±3/71±2 mmHg; ozone: 121±2/71±2 mmHg), cardiac output (clean air: 7.42±0.29 mmHg; ozone: 7.98±0.60 l/min), and plasma norepinephrine levels (clean air: 213±21 pg/ml; ozone: 202±16 pg/ml), were similar on both study days. No difference of resting MSNA was observed between ozone and air exposure (air: 23±2, ozone: 23±2 bursts/min). Maximum MSNA obtained at the end of apnea (air: 44±4, ozone: 48±4 bursts/min) and during the phase II of the Valsalva maneuver (air: 64±5, ozone: 57±6 bursts/min) was similar. Conclusions/Significance Our study suggests that acute ozone-induced airway inflammation does not increase resting sympathetic nerve traffic in healthy subjects, an observation that is relevant for environmental health. However, we can not exclude that chronic airway inflammation may contribute to sympathetic activation. PMID:21494635

A direct sensitivity approach to predict hourly ozone resulting from compliance with the National Ambient Air Quality Standard.

PubMed

Simon, Heather; Baker, Kirk R; Akhtar, Farhan; Napelenok, Sergey L; Possiel, Norm; Wells, Benjamin; Timin, Brian

2013-03-05

In setting primary ambient air quality standards, the EPA's responsibility under the law is to establish standards that protect public health. As part of the current review of the ozone National Ambient Air Quality Standard (NAAQS), the US EPA evaluated the health exposure and risks associated with ambient ozone pollution using a statistical approach to adjust recent air quality to simulate just meeting the current standard level, without specifying emission control strategies. One drawback of this purely statistical concentration rollback approach is that it does not take into account spatial and temporal heterogeneity of ozone response to emissions changes. The application of the higher-order decoupled direct method (HDDM) in the community multiscale air quality (CMAQ) model is discussed here to provide an example of a methodology that could incorporate this variability into the risk assessment analyses. Because this approach includes a full representation of the chemical production and physical transport of ozone in the atmosphere, it does not require assumed background concentrations, which have been applied to constrain estimates from past statistical techniques. The CMAQ-HDDM adjustment approach is extended to measured ozone concentrations by determining typical sensitivities at each monitor location and hour of the day based on a linear relationship between first-order sensitivities and hourly ozone values. This approach is demonstrated by modeling ozone responses for monitor locations in Detroit and Charlotte to domain-wide reductions in anthropogenic NOx and VOCs emissions. As seen in previous studies, ozone response calculated using HDDM compared well to brute-force emissions changes up to approximately a 50% reduction in emissions. A new stepwise approach is developed here to apply this method to emissions reductions beyond 50% allowing for the simulation of more stringent reductions in ozone concentrations. Compared to previous rollback methods, this application of modeled sensitivities to ambient ozone concentrations provides a more realistic spatial response of ozone concentrations at monitors inside and outside the urban core and at hours of both high and low ozone concentrations.

Tropospheric Ozone Climatology over Irene, South Africa, From 1990-1994 and 1998-2002

NASA Technical Reports Server (NTRS)

Diab, R. D.; Thompson, A. M.; Marl, K.; Ramsay, L.; Coetzee, G. J. R.

2004-01-01

This paper describes ozone profiles from sonde data during the period of NASA s TRACE-A and the more recent SHADOZ (Southern Hemisphere Additional Ozonesondes) period. The data were taken by the South African Weather Service at the Irene (25 deg.54 min S; 28 deg. 13 min. E) station near Pretoria, South Africa, an area that is a unique mixture of local industry, heavy biofuels use and importation of biomass burning ozone from neighboring countries to the north. The main findings are: (1) With its geographical position at the edge of the subtropical transition zone, mid- latitude dynamical influences are evident at Irene, predominantly in winter when upper tropospheric ozone is enhanced as a result of stratospheric-tropospheric exchange. (2) There has been an increase in the near-surface ozone amount between the early 1990s and a decade later, presumably due to an influx of rural population toward the Johannesburg-Pretoria area, as well as with industrial growth and development. (3) Most significant for developing approaches for satellite ozone profile climatologies, cluster analysis has enabled the delineation of a background and "most polluted" profile. Enhancements of at least 30% occur throughout the troposphere in spring and in certain layers increases of 100 % are observed.

Characteristics of stratospheric ozone intrusions into the lower free troposphere in subtropical East Asia

NASA Astrophysics Data System (ADS)

Ou-Yang, C. F.; Lin, J. R.; Yen, M. C.; Sheu, G. R.; Wang, J. L.; Lin, N. H.

2017-12-01

Stratospheric intrusion (SI) is mainly induced by tropopause folds, frontal passages, cutoff lows, and surface pressure systems. Ozone can be increased rapidly by the SI with decreased humidity and other primary air pollutants in the lower free troposphere. We present 5 years of ozone observed at Lulin Atmospheric Background Station (LABS, 23.47°N, 120.87°E, 2862 m a.s.l.) as a representative regional mountain site located in subtropical East Asia from April 2006 to March 2011. A fast-screening algorithm was proposed to sift the SI events at the LABS. The ozone was increased approximately 13.5±6.1 ppb on average during the 54 detected SI events, whereas the mean ozone mixing ratio was calculated to be 32.8±15.2 ppb over the 5 years. Distinct seasonal variation of ozone was observed with a maximum in spring and a minimum in summer, which was predominately shaped by the long-range transport of biomass burning air masses from Southeast Asia and oceanic influences from the Pacific, respectively. By contrast, the SI events were observed at the LABS mainly during wintertime. The characteristics of the SI events were also investigated in association with Modern Era Retrospective Analysis - 2 (MERRA-2) assimilated data provided by NASA/GSFC in this study.

Decadal trends in tropospheric ozone over East Asian Pacific rim during 1998-2007: Implications for emerging Asian emissions impacts and comparison to European and North American records (Invited)

NASA Astrophysics Data System (ADS)

Tanimoto, H.; Ohara, T.; Uno, I.

2010-12-01

We examine springtime ozone trends at nine remote locations in East Asian Pacific rim during the last decade (1998-2007). The observed decadal ozone trends are relatively small at surface sites but are substantially larger at a mountainous site. The level and increasing rate of ozone at the mountainous site are both higher than those observed at background sites in Europe and North America. We use a regional chemistry-transport model to explore the observed changes and how changes in Asian anthropogenic emissions have contributed to the observed increasing trends. The model with yearly-dependent regional emissions successfully reproduces the levels, variability, and interannual variations of ozone at all the surface sites. It predicts increasing trends at the mountainous site, suggesting that increasing Asian anthropogenic emissions account for about half the observed increase. However, the discrepancy between the observation and model results after 2003 (the time of largest emission increase) suggests significant underestimation of the actual growth of the Asian anthropogenic emissions and/or incompleteness in the modeling of pollution export from continental Asia. These findings imply that improving emissions inventory and transport scheme is needed to better understand rapidly evolving tropospheric ozone in East Asia and its potential climatic and environmental impacts.

Health Benefits from Large-Scale Ozone Reduction in the United States

PubMed Central

Berman, Jesse D.; Fann, Neal; Hollingsworth, John W.; Pinkerton, Kent E.; Rom, William N.; Szema, Anthony M.; Breysse, Patrick N.; White, Ronald H.

2012-01-01

Background: Exposure to ozone has been associated with adverse health effects, including premature mortality and cardiopulmonary and respiratory morbidity. In 2008, the U.S. Environmental Protection Agency (EPA) lowered the primary (health-based) National Ambient Air Quality Standard (NAAQS) for ozone to 75 ppb, expressed as the fourth-highest daily maximum 8-hr average over a 24-hr period. Based on recent monitoring data, U.S. ozone levels still exceed this standard in numerous locations, resulting in avoidable adverse health consequences. Objectives: We sought to quantify the potential human health benefits from achieving the current primary NAAQS standard of 75 ppb and two alternative standard levels, 70 and 60 ppb, which represent the range recommended by the U.S. EPA Clean Air Scientific Advisory Committee (CASAC). Methods: We applied health impact assessment methodology to estimate numbers of deaths and other adverse health outcomes that would have been avoided during 2005, 2006, and 2007 if the current (or lower) NAAQS ozone standards had been met. Estimated reductions in ozone concentrations were interpolated according to geographic area and year, and concentration–response functions were obtained or derived from the epidemiological literature. Results: We estimated that annual numbers of avoided ozone-related premature deaths would have ranged from 1,410 to 2,480 at 75 ppb to 2,450 to 4,130 at 70 ppb, and 5,210 to 7,990 at 60 ppb. Acute respiratory symptoms would have been reduced by 3 million cases and school-loss days by 1 million cases annually if the current 75-ppb standard had been attained. Substantially greater health benefits would have resulted if the CASAC-recommended range of standards (70–60 ppb) had been met. Conclusions: Attaining a more stringent primary ozone standard would significantly reduce ozone-related premature mortality and morbidity. PMID:22809899

Convective forcing of mercury and ozone in the Arctic boundary layer induced by leads in sea ice.

PubMed

Moore, Christopher W; Obrist, Daniel; Steffen, Alexandra; Staebler, Ralf M; Douglas, Thomas A; Richter, Andreas; Nghiem, Son V

2014-02-06

The ongoing regime shift of Arctic sea ice from perennial to seasonal ice is associated with more dynamic patterns of opening and closing sea-ice leads (large transient channels of open water in the ice), which may affect atmospheric and biogeochemical cycles in the Arctic. Mercury and ozone are rapidly removed from the atmospheric boundary layer during depletion events in the Arctic, caused by destruction of ozone along with oxidation of gaseous elemental mercury (Hg(0)) to oxidized mercury (Hg(II)) in the atmosphere and its subsequent deposition to snow and ice. Ozone depletion events can change the oxidative capacity of the air by affecting atmospheric hydroxyl radical chemistry, whereas atmospheric mercury depletion events can increase the deposition of mercury to the Arctic, some of which can enter ecosystems during snowmelt. Here we present near-surface measurements of atmospheric mercury and ozone from two Arctic field campaigns near Barrow, Alaska. We find that coastal depletion events are directly linked to sea-ice dynamics. A consolidated ice cover facilitates the depletion of Hg(0) and ozone, but these immediately recover to near-background concentrations in the upwind presence of open sea-ice leads. We attribute the rapid recoveries of Hg(0) and ozone to lead-initiated shallow convection in the stable Arctic boundary layer, which mixes Hg(0) and ozone from undepleted air masses aloft. This convective forcing provides additional Hg(0) to the surface layer at a time of active depletion chemistry, where it is subject to renewed oxidation. Future work will need to establish the degree to which large-scale changes in sea-ice dynamics across the Arctic alter ozone chemistry and mercury deposition in fragile Arctic ecosystems.

Surface and Tropospheric Ozone Profile Variability (1999-2014) at the TOLNet Site of Table Mountain, California

NASA Astrophysics Data System (ADS)

Granados-Muñoz, M. J.; Leblanc, T.

2015-12-01

Ozone in the lower troposphere acts as an air pollutant affecting human health and vegetation. Tropospheric ozone sources and variability are not yet fully identified or understood and recent studies reveal the importance of increasing the number of tropospheric ozone profiling stations and long term measurements. As part of the international monitoring network NDACC, and the U.S.-based network TOLNet, a differential absorption lidar has been performing tropospheric ozone measurements (3-20 km) at the JPL Table Mountain Facility (TMF, California) since 1999, and surface measurements have been performed since 2013 with a UV photometric analyzer. Because of the site's geolocation and high elevation, background tropospheric ozone, unaffected by the boundary layer dynamics and local anthropogenic emissions of ozone precursors, is usually expected. However, transboundary ozone contributions such as stratospheric intrusions and Asian pollution episodes are frequently detected. In this study, a statistical analysis of the 14-year lidar profiles and the 2.5-year surface data is presented. Seasonal, interannual and diurnal variability and its possible causes (e.g. El Nino/La Nina events, North American Monsoon) are investigated. Together with the high elevation surface data gathered at TMF, surface data from ARB stations nearby are analyzed to understand the lowermost tropospheric ozone variability component. The frequency of stratospheric intrusions and Asian pollution episodes reaching the Western U.S. is also examined in an attempt to understand the relative contribution of each process to the observed variability throughout the troposphere. The Table Mountain surface and lidar measurements are expected to contribute significantly to the emerging system of global air quality observations, and to the improvement of global and regional data assimilation and modeling.

Global health benefits of mitigating ozone pollution with methane emission controls.

PubMed

West, J Jason; Fiore, Arlene M; Horowitz, Larry W; Mauzerall, Denise L

2006-03-14

Methane (CH(4)) contributes to the growing global background concentration of tropospheric ozone (O(3)), an air pollutant associated with premature mortality. Methane and ozone are also important greenhouse gases. Reducing methane emissions therefore decreases surface ozone everywhere while slowing climate warming, but although methane mitigation has been considered to address climate change, it has not for air quality. Here we show that global decreases in surface ozone concentrations, due to methane mitigation, result in substantial and widespread decreases in premature human mortality. Reducing global anthropogenic methane emissions by 20% beginning in 2010 would decrease the average daily maximum 8-h surface ozone by approximately 1 part per billion by volume globally. By using epidemiologic ozone-mortality relationships, this ozone reduction is estimated to prevent approximately 30,000 premature all-cause mortalities globally in 2030, and approximately 370,000 between 2010 and 2030. If only cardiovascular and respiratory mortalities are considered, approximately 17,000 global mortalities can be avoided in 2030. The marginal cost-effectiveness of this 20% methane reduction is estimated to be approximately 420,000 US dollars per avoided mortality. If avoided mortalities are valued at 1 US dollars million each, the benefit is approximately 240 US dollars per tone of CH(4) ( approximately 12 US dollars per tone of CO(2) equivalent), which exceeds the marginal cost of the methane reduction. These estimated air pollution ancillary benefits of climate-motivated methane emission reductions are comparable with those estimated previously for CO(2). Methane mitigation offers a unique opportunity to improve air quality globally and can be a cost-effective component of international ozone management, bringing multiple benefits for air quality, public health, agriculture, climate, and energy.

Reprocessed Southern Hemisphere Additional Ozonesondes (SHADOZ) Profiles (1998-2016): Method, Uncertainties and Comparisons with Satellite Total Ozone

NASA Astrophysics Data System (ADS)

Stauffer, R. M.; Thompson, A. M.; Witte, J. C.; Johnson, B.; Smit, H. G. J.

2017-12-01

The SHADOZ network was assembled to validate a new generation of ozone-monitoring satellites and to better characterize the vertical structure of tropical stratospheric and tropospheric ozone. Beginning with nine stations in 1998, more than 7000 ozone and P-T-U profiles are available from 14 stations that have operated for at least a decade. In the past two years the SHADOZ records have been reprocessed to adjust for inconsistencies caused by varying ozonesonde instruments and operating techniques. We have followed consensus-based guidelines given by the international ozonesonde community and will release new records that include first estimates of uncertainties in the ozonesonde instrument system. The ozone uncertainty is a composite of uncertainties of the individual terms in the ozone partial pressure (PO3) equation, i.e., ozone sensor current, background current, internal pump temperature, pump efficiency factors, conversion efficiency, and flow-rate. Overall, SHADOZ PO3 uncertainties are 15% or less and peak around the tropopause (15±3km) where the ozone current can approach the detection limit of the sensor. The sonde total column ozone (TCO) uncertainty is estimated at ±15 DU or 5% of typical tropical TCO. When sonde-derived TCO is compared to overpasses from the EP/TOMS, OMI and OMPS satellites that cover 1998-2016, sonde-satellite offsets at 12 stations are 2% or less (Figure), well within the uncertainty of both satellite and sonde. This agreement is much improved over our earlier SHADOZ evaluations (2003, 2007 and 2012). Reprocessing has also led to more uniform stratospheric column amounts across sites within +19 degrees latitude and reduced profile bias.

Concentration–Response Function for Ozone and Daily Mortality: Results from Five Urban and Five Rural U.K. Populations

PubMed Central

Yu, Dahai; Armstrong, Ben G.; Pattenden, Sam; Wilkinson, Paul; Doherty, Ruth M.; Heal, Mathew R.; Anderson, H. Ross

2012-01-01

Background: Short-term exposure to ozone has been associated with increased daily mortality. The shape of the concentration–response relationship—and, in particular, if there is a threshold—is critical for estimating public health impacts. Objective: We investigated the concentration–response relationship between daily ozone and mortality in five urban and five rural areas in the United Kingdom from 1993 to 2006. Methods: We used Poisson regression, controlling for seasonality, temperature, and influenza, to investigate associations between daily maximum 8-hr ozone and daily all-cause mortality, assuming linear, linear-threshold, and spline models for all-year and season-specific periods. We examined sensitivity to adjustment for particles (urban areas only) and alternative temperature metrics. Results: In all-year analyses, we found clear evidence for a threshold in the concentration–response relationship between ozone and all-cause mortality in London at 65 µg/m3 [95% confidence interval (CI): 58, 83] but little evidence of a threshold in other urban or rural areas. Combined linear effect estimates for all-cause mortality were comparable for urban and rural areas: 0.48% (95% CI: 0.35, 0.60) and 0.58% (95% CI: 0.36, 0.81) per 10-µg/m3 increase in ozone concentrations, respectively. Seasonal analyses suggested thresholds in both urban and rural areas for effects of ozone during summer months. Conclusions: Our results suggest that health impacts should be estimated across the whole ambient range of ozone using both threshold and nonthreshold models, and models stratified by season. Evidence of a threshold effect in London but not in other study areas requires further investigation. The public health impacts of exposure to ozone in rural areas should not be overlooked. PMID:22814173

Using dissolved gas analysis to investigate the performance of an organic carbon permeable reactive barrier for the treatment of mine drainage

USGS Publications Warehouse

Williams, R.L.; Mayer, K.U.; Amos, R.T.; Blowes, D.W.; Ptacek, C.J.; Bain, J.G.

2007-01-01

The strongly reducing nature of permeable reactive barrier (PRB) treatment materials can lead to gas production, potentially resulting in the formation of gas bubbles and ebullition. Degassing in organic C based PRB systems due to the production of gases (primarily CO2 and CH4) is investigated using the depletion of naturally occurring non-reactive gases Ar and N2, to identify, confirm, and quantify chemical and physical processes. Sampling and analysis of dissolved gases were performed at the Nickel Rim Mine Organic Carbon PRB, which was designed for the treatment of groundwater contaminated by low quality mine drainage characterized by slightly acidic pH, and elevated Fe(II) and SO4 concentrations. A simple 4-gas degassing model was used to analyze the dissolved gas data, and the results indicate that SO4 reduction is by far the dominant process of organic C consumption within the barrier. The data provided additional information to delineate rates of microbially mediated SO4 reduction and confirm the presence of slow and fast flow zones within the barrier. Degassing was incorporated into multicomponent reactive transport simulations for the barrier and the simulations were successful in reproducing observed dissolved gas trends.

Ovarian steroid hormones modulate the expression of progesterone receptors and histone acetylation patterns in uterine leiomyoma cells.

PubMed

Sant'Anna, Gabriela Dos Santos; Brum, Ilma Simoni; Branchini, Gisele; Pizzolato, Lolita Schneider; Capp, Edison; Corleta, Helena von Eye

2017-08-01

Uterine leiomyomas are the most common benign smooth muscle cell tumors in women. Estrogen (E2), progesterone (P4) and environmental factors play important roles in the development of these tumors. New treatments, such as mifepristone, have been proposed. We evaluated the gene expression of total (PRT) and B (PRB) progesterone receptors, and the histone acetyltransferase (HAT) and deacetylase (HDAC) activity after treatment with E2, P4 and mifepristone (RU486) in primary cell cultures from uterine leiomyoma and normal myometrium. Compared to myometrium, uterine leiomyoma cells showed an increase in PRT mRNA expression when treated with E2, and increase in PRB mRNA expression when treated with E2 and P4. Treatment with mifepristone had no significant impact on mRNA expression in these cells. The HDAC activity was higher in uterine leiomyoma compared to myometrial cells after treatment with E2 and E2 + P4 + mifepristone. HAT activity was barely detectable. Our results suggest that ovarian steroid hormones modulate PR, and mifepristone was unable to decrease PRT and PRB mRNA. The higher activity of HDAC leiomyoma cells could be involved in transcriptional repression of genes implicated in normal myometrium cell function, contributing to the maintenance and growth of uterine leiomyoma.

In vitro cytotoxic potential of friedelin in human MCF-7 breast cancer cell: Regulate early expression of Cdkn2a and pRb1, neutralize mdm2-p53 amalgamation and functional stabilization of p53.

PubMed

Subash-Babu, Pandurangan; Li, David K; Alshatwi, Ali A

2017-10-02

We aimed to explore the cytotoxic and apoptotic effect of friedelin on breast cancer MCF-7 cells. Cytotoxic effect of friedelin on MCF-7 cells was analyzed using MTT, cell and nuclear morphology. The apoptosis mechanism of friedelin on MCF-7 cells was analyzed using real-time PCR. Friedelin potentially inhibit 78% of MCF-7 cell's growth, the IC 50 value was 1.8μM in 24h and 1.2μM in 48h. Friedelin increased ROS significantly and DNA damage was confirmed by tunel assay. We found characteristically 52% apoptotic cells and 6% necrotic cells in PI, AO/ErBr staining after 48h treatment with 1.2μM of friedelin. Apoptosis was confirmed by significantly (p≤0.001) increased tumor suppressor gene Cdkn1a, pRb2, p53, Nrf2, caspase-3 and decreased Bcl-2, mdm2 & PCNA expression after 48h. In conclusion, friedelin effectively inhibit breast cancer MCF-7 cell growth, it was associated with early expression of Cdkn1a, pRb2 and activation of p53 and caspases. Copyright © 2017. Published by Elsevier GmbH.

Electrical conductivity of the crust in central Baja California, México, based on magnetotelluric observations

NASA Astrophysics Data System (ADS)

Romo, J. M.; Gómez-Treviño, E.; Flores-Luna, C.; García-Abdeslem, J.

2017-12-01

Crustal and sub-crustal structure of northwestern Mexico (peninsular California) resulted from major accretion episodes occurred during the long-lived subduction of the Farallon plate beneath the North American plate, since late Jurassic time. A magnetotelluric profile across central Baja California reveals several electrical conductivity anomalies probably associated to the crustal boundaries of distinct Mezosoic terranes juxtaposed in the current peninsular crust. It is known that electrical conductivity is significantly increased by the pervasive presence of conductive minerals generated during metamorphic processes in highly sheared zones. We interpret a striking sub-horizontal conductivity anomaly reveled in the model as explained by the presence of high-salinity fluids released after dehydration of the subducted Magdalena microplate (Farallon plate?). The presence of fluids at the base of the peninsular crust may produce a zone of weakness, which supports the idea that Baja California lithosphere has not been entirely coupled to the Pacific plate. In addition, crustal thickness is estimated in our model in about 35 km beneath the western Peninsular Ranges batholith (PRB) and 20 km beneath the eastern PRB. This crustal thickness is in good agreement with independent estimations of a thinner crust in the Gulf of California margin and a thicker crust along the axial PRB.

Microbial Sulfate Reduction Enhances Arsenic Mobility Downstream of Zerovalent-Iron-Based Permeable Reactive Barrier.

PubMed

Kumar, Naresh; Couture, Raoul-Marie; Millot, Romain; Battaglia-Brunet, Fabienne; Rose, Jérôme

2016-07-19

We assessed the potential of zerovalent-iron- (Fe(0)) based permeable reactive barrier (PRB) systems for arsenic (As) remediation in the presence or absence of microbial sulfate reduction. We conducted long-term (200 day) flow-through column experiments to investigate the mechanisms of As transformation and mobility in aquifer sediment (in particular, the PRB downstream linkage). Changes in As speciation in the aqueous phase were monitored continuously. Speciation in the solid phase was determined at the end of the experiment using X-ray absorption near-edge structure (XANES) spectroscopy analysis. We identified thio-As species in solution and AsS in solid phase, which suggests that the As(V) was reduced to As(III) and precipitated as AsS under sulfate-reducing conditions and remained as As(V) under abiotic conditions, even with low redox potential and high Fe(II) content (4.5 mM). Our results suggest that the microbial sulfate reduction plays a key role in the mobilization of As from Fe-rich aquifer sediment under anoxic conditions. Furthermore, they illustrate that the upstream-downstream linkage of PRB affects the speciation and mobility of As in downstream aquifer sediment, where up to 47% of total As initially present in the sediment was leached out in the form of mobile thio-As species.

Acetylation at lysine 346 controls the transforming activity of the HTLV-1 Tax oncoprotein in the Rat-1 fibroblast model

PubMed Central

2013-01-01

Background Transformation by the Tax oncoprotein of the human T cell leukemia virus type 1 (HTLV-1) is governed by actions on cellular regulatory signals, including modulation of specific cellular gene expression via activation of signaling pathways, acceleration of cell cycle progression via stimulation of cyclin-dependent kinase activity leading to retinoblastoma protein (pRb) hyperphosphorylation and perturbation of survival signals. These actions control early steps in T cell transformation and development of Adult T cell leukemia (ATL), an aggressive malignancy of HTLV-1 infected T lymphocytes. Post-translational modifications of Tax by phosphorylation, ubiquitination, sumoylation and acetylation have been implicated in Tax-mediated activation of the NF-κB pathway, a key function associated with Tax transforming potential. Results In this study, we demonstrate that acetylation at lysine K346 in the carboxy-terminal domain of Tax is modulated in the Tax nuclear bodies by the acetyltransferase p300 and the deacetylases HDAC5/7 and controls phosphorylation of the tumor suppressor pRb by Tax-cyclin D3-CDK4-p21CIP complexes. This property correlates with the inability of the acetylation deficient K346R mutant, but not the acetylation mimetic K346Q mutant, to promote anchorage-independent growth of Rat-1 fibroblasts. By contrast, acetylation at lysine K346 had no effects on the ability of Tax carboxy-terminal PDZ-binding domain to interact with the tumor suppressor hDLG. Conclusions The identification of the acetyltransferase p300 and the deacetylase HDAC7 as enzymes modulating Tax acetylation points to new therapeutic targets for the treatment of HTLV-1 infected patients at risk of developing ATL. PMID:23880157

Ensemble simulations of the role of the stratosphere in the attribution of northern extratropical tropospheric ozone variability

NASA Astrophysics Data System (ADS)

Hess, P.; Kinnison, D.; Tang, Q.

2015-03-01

Despite the need to understand the impact of changes in emissions and climate on tropospheric ozone, the attribution of tropospheric interannual ozone variability to specific processes has proven difficult. Here, we analyze the stratospheric contribution to tropospheric ozone variability and trends from 1953 to 2005 in the Northern Hemisphere (NH) mid-latitudes using four ensemble simulations of the free running (FR) Whole Atmosphere Community Climate Model (WACCM). The simulations are externally forced with observed time-varying (1) sea-surface temperatures (SSTs), (2) greenhouse gases (GHGs), (3) ozone depleting substances (ODS), (4) quasi-biennial oscillation (QBO), (5) solar variability (SV) and (6) stratospheric sulfate surface area density (SAD). A detailed representation of stratospheric chemistry is simulated, including the ozone loss due to volcanic eruptions and polar stratospheric clouds. In the troposphere, ozone production is represented by CH4-NOx smog chemistry, where surface chemical emissions remain interannually constant. Despite the simplicity of its tropospheric chemistry, at many NH measurement locations, the interannual ozone variability in the FR WACCM simulations is significantly correlated with the measured interannual variability. This suggests the importance of the external forcing applied in these simulations in driving interannual ozone variability. The variability and trend in the simulated 1953-2005 tropospheric ozone from 30 to 90° N at background surface measurement sites, 500 hPa measurement sites and in the area average are largely explained on interannual timescales by changes in the 30-90° N area averaged flux of ozone across the 100 hPa surface and changes in tropospheric methane concentrations. The average sensitivity of tropospheric ozone to methane (percent change in ozone to a percent change in methane) from 30 to 90° N is 0.17 at 500 hPa and 0.21 at the surface; the average sensitivity of tropospheric ozone to the 100 hPa ozone flux (percent change in ozone to a percent change in the ozone flux) from 30 to 90° N is 0.19 at 500 hPa and 0.11 at the surface. The 30-90° N simulated downward residual velocity at 100 hPa increased by 15% between 1953 and 2005. However, the impact of this on the 30-90° N 100 hPa ozone flux is modulated by the long-term changes in stratospheric ozone. The ozone flux decreases from 1965 to 1990 due to stratospheric ozone depletion, but increases again by approximately 7% from 1990 to 2005. The first empirical orthogonal function of interannual ozone variability explains from 40% (at the surface) to over 80% (at 150 hPa) of the simulated ozone interannual variability from 30 to 90° N. This identified mode of ozone variability shows strong stratosphere-troposphere coupling, demonstrating the importance of the stratosphere in an attribution of tropospheric ozone variability. The simulations, with no change in emissions, capture almost 50% of the measured ozone change during the 1990s at a variety of locations. This suggests that a large portion of the measured change is not due to changes in emissions, but can be traced to changes in large-scale modes of ozone variability. This emphasizes the difficulty in the attribution of ozone changes, and the importance of natural variability in understanding the trends and variability of ozone. We find little relation between the El Niño-Southern Oscillation (ENSO) index and large-scale tropospheric ozone variability over the long-term record.

Inhibition of Human Cytomegalovirus Replication by Artemisinins: Effects Mediated through Cell Cycle Modulation

PubMed Central

Roy, Sujayita; He, Ran; Kapoor, Arun; Forman, Michael; Mazzone, Jennifer R.; Posner, Gary H.

2015-01-01

Artemisinin-derived monomers and dimers inhibit human cytomegalovirus (CMV) replication in human foreskin fibroblasts (HFFs). The monomer artesunate (AS) inhibits CMV at micromolar concentrations, while dimers inhibit CMV replication at nanomolar concentrations, without increased toxicity in HFFs. We report on the variable anti-CMV activity of AS compared to the consistent and reproducible CMV inhibition by dimer 606 and ganciclovir (GCV). Investigation of this phenomenon revealed that the anti-CMV activity of AS correlated with HFFs synchronized to the G0/G1 stage of the cell cycle. In contact-inhibited serum-starved HFFs or cells arrested at early/late G1 with specific checkpoint regulators, AS and dimer 606 efficiently inhibited CMV replication. However, in cycling HFFs, in which CMV replication was productive, virus inhibition by AS was significantly reduced, but inhibition by dimer 606 and GCV was maintained. Cell cycle analysis in noninfected HFFs revealed that AS induced early G1 arrest, while dimer 606 partially blocked cell cycle progression. In infected HFFs, AS and dimer 606 prevented the progression of cell cycle toward the G1/S checkpoint. AS reduced the expression of cyclin-dependent kinases (CDK) 2, 4, and 6 in noninfected cycling HFFs, while the effect of dimer 606 on these CDKs was moderate. Neither compound affected CDK expression in noninfected contact-inhibited HFFs. In CMV-infected cells, AS activity correlated with reduced CDK2 levels. CMV inhibition by AS and dimer 606 also correlated with hypophosphorylation (activity) of the retinoblastoma protein (pRb). AS activity was strongly associated with pRb hypophosphorylation, while its reduced anti-CMV activity was marked by pRb phosphorylation. Roscovitine, a CDK2 inhibitor, antagonized the anti-CMV activities of AS and dimer 606. These data suggest that cell cycle modulation through CDKs and pRb might play a role in the anti-CMV activities of artemisinins. Proteins involved in this modulation may be identified and targeted for CMV inhibition. PMID:25870074

Increased mitochondrial function downstream from KDM5A histone demethylase rescues differentiation in pRB-deficient cells

PubMed Central

Váraljai, Renáta; Islam, Abul B.M.M.K.; Beshiri, Michael L.; Rehman, Jalees; Lopez-Bigas, Nuria; Benevolenskaya, Elizaveta V.

2015-01-01

The retinoblastoma tumor suppressor protein pRb restricts cell growth through inhibition of cell cycle progression. Increasing evidence suggests that pRb also promotes differentiation, but the mechanisms are poorly understood, and the key question remains as to how differentiation in tumor cells can be enhanced in order to diminish their aggressive potential. Previously, we identified the histone demethylase KDM5A (lysine [K]-specific demethylase 5A), which demethylates histone H3 on Lys4 (H3K4), as a pRB-interacting protein counteracting pRB's role in promoting differentiation. Here we show that loss of Kdm5a restores differentiation through increasing mitochondrial respiration. This metabolic effect is both necessary and sufficient to induce the expression of a network of cell type-specific signaling and structural genes. Importantly, the regulatory functions of pRB in the cell cycle and differentiation are distinct because although restoring differentiation requires intact mitochondrial function, it does not necessitate cell cycle exit. Cells lacking Rb1 exhibit defective mitochondria and decreased oxygen consumption. Kdm5a is a direct repressor of metabolic regulatory genes, thus explaining the compensatory role of Kdm5a deletion in restoring mitochondrial function and differentiation. Significantly, activation of mitochondrial function by the mitochondrial biogenesis regulator Pgc-1α (peroxisome proliferator-activated receptor γ-coactivator 1α; also called PPARGC1A) a coactivator of the Kdm5a target genes, is sufficient to override the differentiation block. Overexpression of Pgc-1α, like KDM5A deletion, inhibits cell growth in RB-negative human cancer cell lines. The rescue of differentiation by loss of KDM5A or by activation of mitochondrial biogenesis reveals the switch to oxidative phosphorylation as an essential step in restoring differentiation and a less aggressive cancer phenotype. PMID:26314709

Lead contamination in sediments in the past 20 years: A challenge for China.

PubMed

Han, Lanfang; Gao, Bo; Hao, Hong; Zhou, Huaidong; Lu, Jin; Sun, Ke

2018-06-04

Lead (Pb) contamination was recognized in China early in the 1920s. However, the response of Pb contamination in sediments to China's rapid economic and social development remains uncertain to date. We conducted a literature review of over 1000 articles from 1990 to 2016 and the first national-scale survey of Pb contamination in China. A literature review showed that available research in China focused on the economically highly developed river basins, including the Pearl River Basin (PRB), Yellow River Basin (YRB), and Yangtze River Basin (YtRB), whereas those in the less developed southeastern, southwestern, and northwestern river basins received limited attention. The YtRB and YRB had higher Pb contamination levels than other basins, corresponding with the rapid economic development in those regions. However, the less economically developed river basins in the southeastern and northwestern regions of China were also contaminated by Pb. Analysis of 146 studies in the PRB, YRB, and YtRB revealed that Pb contamination in PRB sediments showed a tendency to improve over time, whereas that from the YtRB exhibited a tendency to worsen. For the YRB, there was a slight increase from 1990 to 2006 and a decreasing trend from 2007 to 2014. The overall temporal trend in Pb levels in PRB and YRB sediments corresponded with that of the Pb discharged in wastewater in the surrounding cities, indicating that industrial wastewater discharge was possibly one of the main anthropogenic sources of Pb in those sediments. For the YtRB, the increasing trend in Pb concentrations was related to the considerably high atmospheric Pb emissions in the surrounding cities and its geographical characteristics. These findings suggested that China should develop systematic and consistent approaches for monitoring Pb contents in sediments and adopt a regional economic development policy focusing on pollution prevention. Copyright © 2018 Elsevier B.V. All rights reserved.

Enhanced expression of cyclins and cyclin-dependent kinases in aniline-induced cell proliferation in rat spleen

PubMed Central

Wang, Jianling; Wang, Gangduo; Ma, Huaxian; Khan, M. Firoze

2010-01-01

Aniline exposure is associated with toxicity to the spleen leading to splenomegaly, hyperplasia, fibrosis and a variety of sarcomas of the spleen on chronic exposure. In earlier studies, we have shown that aniline exposure leads to iron overload, oxidative stress and activation of redox-sensitive transcription factors, which could regulate various genes leading to a tumorigenic response in the spleen. However, molecular mechanisms leading to aniline-induced cellular proliferation in the spleen remain largely unknown. This study was, therefore, undertaken on the regulation of G1 phase cell cycle proteins (cyclins), expression of cyclin-dependent kinases (CDKs), phosphorylation of retinoblastoma protein (pRB) and cell proliferation in the spleen, in an experimental condition preceding a tumorigenic response. Male SD rats were treated with aniline (0.5 mmol/kg/day via drinking water) for 30 days (controls received drinking water only), and splenocyte proliferation, protein expression of G1 phase cyclins, CDKs and pRB were measured. Aniline treatment resulted in significant increases in splenocyte proliferation, based on cell counts, cell proliferation markers including proliferating cell nuclear antigen (PCNA), nuclear Ki67 protein (Ki67) and minichromosome maintenance (MCM), MTT assay and flow cytometric analysis. Western blot analysis of splenocyte proteins from aniline-treated rats showed significantly increased expression of cyclins D1, D2, D3 and cyclin E, as compared to the controls. Similarly, real-time PCR analysis showed significantly increased mRNA expression for cyclins D1, D2, D3 and E in the spleens of aniline-treated rats. The overexpression of these cyclins was associated with increases in the expression of CDK4, CDK6, CDK2 as well as phosphorylation of pRB protein. Our data suggest that increased expression of cyclins, CDKs and phosphorylation of pRB protein could be critical in cell proliferation, and may contribute to aniline-induced tumorigenic response in the spleen. PMID:21070798

Subtask 1.18 - A Decision Tool for Watershed-Based Effluent Trading

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

Xixi Wang; Bethany A. Kurz; Marc D. Kurz

2006-11-30

Handling produced water in an economical and environmentally sound manner is vital to coalbed methane (CBM) development, which is expected to increase up to 60% in the next 10-15 years as the demand for natural gas increases. Current produced water-handling methods (e.g., shallow reinjection and infiltration impoundments) are too costly when implemented on a well-by-well basis. A watershed-based effluent credit trading approach may be a means of managing produced water at reduced cost while meeting or surpassing water quality regulations. This market-based approach allows for improved water quality management by enabling industrial, agricultural, and municipal discharge facilities to meet watermore » quality permit requirements by purchasing pollutant reduction credits from other entities within the same watershed. An evaluation of this concept was conducted for the Powder River Basin (PRB) of Montana and Wyoming by the Energy & Environmental Research Center (EERC). To conduct this assessment, the EERC collected and evaluated existing water quality information and developed the appropriate tools needed to assess the environmental and economic feasibility of specific trading scenarios. The accomplishments of this study include (1) an exploration of the available PRB water quantity and quality data using advanced statistical techniques, (2) development of an integrated water quality model that predicts the impacts of CBM produced water on stream salinity and sodicity, (3) development of an economic model that estimates costs and benefits from implementing potential trading options, (4) evaluation of hypothetical trading scenarios between select watersheds of the PRB, and (5) communication of the project concept and results to key state and federal agencies, industry representatives, and stakeholders of the PRB. The preliminary results of a basinwide assessment indicate that up to $684 million could be saved basinwide without compromising water quality as a result of implementing a watershed-based credit-trading approach.« less

Enhancement of mercury capture by the simultaneous addition of hydrogen bromide (HBr) and fly ashes in a slipstream facility

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

Yan Cao; Quan-Hai Wang; Jun Li

2009-04-15

Low halogen content in tested Powder River Basin (PRB) coals and low loss of ignition content (LOI) in PRB-derived fly ash were likely responsible for higher elemental mercury content (averaging about 75%) in the flue gas and also lower mercury capture efficiency by electrostatic precipitator (ESP) and wet-FGD. To develop a cost-effective approach to mercury capture in a full-scale coal-fired utility boiler burning PRB coal, experiments were conducted adding hydrogen bromide (HBr) or simultaneously adding HBr and selected fly ashes in a slipstream reactor (0.152 x 0.152 m) under real flue gas conditions. The residence time of the flue gasmore » inside the reactor was about 1.4 s. The average temperature of the slipstream reactor was controlled at about 155{sup o}C. Tests were organized into two phases. In Phase 1, only HBr was added to the slipstream reactor, and in Phase 2, HBr and selected fly ash were added simultaneously. HBr injection was effective (>90%) for mercury oxidation at a low temperature (155{sup o}C) with an HBr addition concentration of about 4 ppm in the flue gas. Additionally, injected HBr enhanced mercury capture by PRB fly ash in the low-temperature range. The mercury capture efficiency, at testing conditions of the slipstream reactor, reached about 50% at an HBr injection concentration of 4 ppm in the flue gas. Compared to only the addition of HBr, simultaneously adding bituminous-derived fly ash in a minimum amount (30 lb/MMacf), together with HBr injection at 4 ppm, could increase mercury capture efficiency by 30%. Injection of lignite-derived fly ash at 30 lb/MMacf could achieve even higher mercury removal efficiency (an additional 35% mercury capture efficiency compared to HBR addition alone). 25 refs., 5 figs., 1 tab.« less

Aviation-attributable ozone as a driver for changes in mortality related to air quality and skin cancer

NASA Astrophysics Data System (ADS)

Eastham, Sebastian D.; Barrett, Steven R. H.

2016-11-01

Aviation is a significant source of tropospheric ozone, which is a critical UV blocking agent, an indirect precursor to the formation of particulate matter, and a respiratory health hazard. To date, investigations of human health impacts related to aviation emissions have focused on particulate matter, and no global estimate yet exists of the combined health impact of aviation due to ozone, particulate matter and UV exposure changes. We use a coupled tropospheric-stratospheric chemical-transport model with a global aviation emissions inventory to estimate the total impact of aviation on all three risk factors. We find that surface ozone due to aviation emissions is maximized during hemispheric winter due to the greater wintertime chemical lifetime of ozone, but that a smaller enhancement of 0.5 ppbv occurs during summertime. This summertime increase results in an estimated 6,800 premature mortalities per year due to ozone exposure, over three times greater than previous estimates. During the winter maximum, interaction with high background NOx concentrations results in enhanced production of nitrate aerosol and increased annual average exposure to particulate matter. This ozone perturbation is shown to be the driving mechanism behind an additional 9,200 premature mortalities due to exposure to particulate matter. However, the increase in tropospheric ozone is also found to result in 400 fewer mortalities due to melanoma skin cancer in 2006. This is the first estimate of global melanoma mortality due to aviation, and the first estimate of skin cancer mortality impacts due to aviation using a global chemical transport model.

High Environmental Ozone Levels Lead to Enhanced Allergenicity of Birch Pollen

PubMed Central

Beck, Isabelle; Jochner, Susanne; Gilles, Stefanie; McIntyre, Mareike; Buters, Jeroen T. M.; Schmidt-Weber, Carsten; Behrendt, Heidrun; Ring, Johannes; Menzel, Annette; Traidl-Hoffmann, Claudia

2013-01-01

Background Evidence is compelling for a positive correlation between climate change, urbanisation and prevalence of allergic sensitisation and diseases. The reason for this association is not clear to date. Some data point to a pro-allergenic effect of anthropogenic factors on susceptible individuals. Objectives To evaluate the impact of urbanisation and climate change on pollen allergenicity. Methods Catkins were sampled from birch trees from different sites across the greater area of Munich, pollen were isolated and an urbanisation index, NO2 and ozone exposure were determined. To estimate pollen allergenicity, allergen content and pollen-associated lipid mediators were measured in aqueous pollen extracts. Immune stimulatory and modulatory capacity of pollen was assessed by neutrophil migration assays and the potential of pollen to inhibit dendritic cell interleukin-12 response. In vivo allergenicity was assessed by skin prick tests. Results The study revealed ozone as a prominent environmental factor influencing the allergenicity of birch pollen. Enhanced allergenicity, as assessed in skin prick tests, was mirrored by enhanced allergen content. Beyond that, ozone induced changes in lipid composition and chemotactic and immune modulatory potential of the pollen. Higher ozone-exposed pollen was characterised by less immune modulatory but higher immune stimulatory potential. Conclusion It is likely that future climate change along with increasing urbanisation will lead to rising ozone concentrations in the next decades. Our study indicates that ozone is a crucial factor leading to clinically relevant enhanced allergenicity of birch pollen. Thus, with increasing temperatures and increasing ozone levels, also symptoms of pollen allergic patients may increase further. PMID:24278250

The Role of Ambient Ozone in Epidemiologic Studies of Heat-Related Mortality

PubMed Central

Snowden, Jonathan M.; Kontgis, Caitlin; Tager, Ira B.

2012-01-01

Background: A large and growing literature investigating the role of extreme heat on mortality has conceptualized the role of ambient ozone in various ways, sometimes treating it as a confounder, sometimes as an effect modifier, and sometimes as a co-exposure. Thus, there is a lack of consensus about the roles that temperature and ozone together play in causing mortality. Objectives: We applied directed acyclic graphs (DAGs) to the topic of heat-related mortality to graphically represent the subject matter behind the research questions and to provide insight on the analytical options available. Discussion: On the basis of the subject matter encoded in the graphs, we assert that the role of ozone in studies of temperature and mortality is a causal intermediate that is affected by temperature and that can also affect mortality, rather than a confounder. Conclusions: We discuss possible questions of interest implied by this causal structure and propose areas of future work to further clarify the role of air pollutants in epidemiologic studies of extreme temperature. PMID:22899622

PRB mines mature

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

Buchsbaum, L.

2007-08-15

Already seeing the results of reclamation efforts, America's largest surface mines advance as engineers prepare for the future. 30 years after the signing of the Surface Mining Control and Reclamation Act by Jimmy Carter, western strip mines in the USA, especially in the Powder River Basin, are producing more coal than ever. The article describes the construction and installation of a $38.5 million near-pit crusher and overland belt conveyor system at Foundation Coal West's (FCW) Belle Ayr surface mine in Wyoming, one of the earliest PRB mines. It goes on to describe the development by Rio Tinto of an elkmore » conservatory, the Rochelle Hill Conservation Easement, on reclaimed land at Jacobs Ranch, adjacent to the Rochelle Hills. 4 photos.« less

Spin-split fermi surfaces in CexLa1-xB6 and PrxLa1-xB6

NASA Astrophysics Data System (ADS)

Isshiki, T.; Endo, M.; Sugi, M.; Kimura, N.; Nakamura, S.; Nojima, T.; Aoki, H.; Kunii, S.

2006-05-01

We have performed the dHvA measurements on CexLa1-xB6 and PrxLa1-xB6 compounds to study spin splitting of the Fermi surfaces. In PrB 6 we have found new frequency branches to confirm that the Fermi surface splits into up and down spin Fermi surfaces, whereas no spin splitting has been found for x=0.25,0.5,0.75. We have also found several new frequency branches in CeB6. The new frequency branches imply that the Fermi surfaces of up and down spin conduction electrons are significantly different in CeB6 as well as in PrB6.

Chemistry and microbiology of permeable reactive barriers for in situ groundwater clean up.

PubMed

Scherer, M M; Richter, S; Valentine, R L; Alvarez, P J

2000-01-01

Permeable reactive barriers (PRBs) are receiving a great deal of attention as an innovative, cost-effective technology for in situ clean up of groundwater contamination. A wide variety of materials are being proposed for use in PRBs, including zero-valent metals (e.g., iron metal), humic materials, oxides, surfactant-modified zeolites (SMZs), and oxygen- and nitrate-releasing compounds. PRB materials remove dissolved groundwater contaminants by immobilization within the barrier or transformation to less harmful products. The primary removal processes include: (1) sorption and precipitation, (2) chemical reaction, and (3) biologically mediated reactions. This article presents an overview of the mechanisms and factors controlling these individual processes and discusses the implications for the feasibility and long-term effectiveness of PRB technologies.

Uterine Artery Flow and Offspring Growth in Long-Evans Rats following Maternal Exposure to Ozone during Implantation

PubMed Central

Dye, Janice A.; Ledbetter, Allen D.; Schladweiler, Mette C.; Richards, Judy H.; Snow, Samantha J.; Wood, Charles E.; Henriquez, Andres R.; Thompson, Leslie C.; Farraj, Aimen K.; Hazari, Mehdi S.; Kodavanti, Urmila P.

2017-01-01

Background: Epidemiological studies suggest that increased ozone exposure during gestation may compromise fetal growth. In particular, the implantation stage of pregnancy is considered a key window of susceptibility for this outcome. Objectives: The main goals of this study were to investigate the effects of short-term ozone inhalation during implantation on fetal growth outcomes and to explore the potential for alterations in uterine arterial flow as a contributing mechanism. Methods: Pregnant Long-Evans rats were exposed to filtered air, 0.4 ppm ozone, or 0.8 ppm ozone for 4 h/d during implantation, on gestation days (GD) 5 and 6. Tail cuff blood pressure and uterine artery Doppler ultrasound were measured on GD 15, 19, and 21. To assess whether peri-implantation ozone exposure resulted in sustained pulmonary or systemic health effects, bronchoalveolar lavage fluid, serum metabolic and inflammatory end points, and kidney histopathology were evaluated in dams at GD 21. Growth parameters assessed in GD 21 offspring included fetal weight, length, and body composition. Results: Measures of maternal uterine arterial flow, including resistance index and mean velocity, indicated that resistance increased between GD 15 and GD 21 in 0.8 ppm dams but decreased in controls, although absolute values were similar in both groups on GD 21. Ozone-exposed dams also had lower serum glucose and higher free fatty acid concentrations than controls on GD 21. On GD 21, both male and female offspring had lower body weight than controls, and pooled subsets of 3 male and 3 female fetuses from litters exposed to 0.8 ppm ozone had lower lean mass and fat mass than pooled control offspring. Conclusions: Findings from our experimental model suggest that the offspring of dams exposed to ozone during implantation had reduced growth compared with controls, possibly as a consequence of ozone-induced vascular dysfunction. https://doi.org/10.1289/EHP2019 PMID:29269335

Tropospheric Ozone and Photochemical Smog

NASA Astrophysics Data System (ADS)

Sillman, S.

2003-12-01

The question of air quality in polluted regions represents one of the issues of geochemistry with direct implications for human well-being. Human health and well-being, along with the well-being of plants, animals, and agricultural crops, are dependent on the quality of air we breathe. Since the start of the industrial era, air quality has become a matter of major importance, especially in large cities or urbanized regions with heavy automobile traffic and industrial activity.Concern over air quality existed as far back as the 1600s. Originally, polluted air in cities resulted from the burning of wood or coal, largely as a source of heat. The industrial revolution in England saw a great increase in the use of coal in rapidly growing cities, both for industrial use and domestic heating. London suffered from devastating pollution events during the late 1800s and early 1900s, with thousands of excess deaths attributed to air pollution (Brimblecombe, 1987). With increasing use of coal, other instances also occurred in continental Europe and the USA. These events were caused by directly emitted pollutants (primary pollutants), including sulfur dioxide (SO2), carbon monoxide (CO), and particulates. They were especially acute in cities with northerly locations during fall and winter when sunlight is at a minimum. These original pollution events gave rise to the term "smog" (a combination of smoke and fog). Events of this type have become much less severe since the 1950s in Western Europe and the US, as natural gas replaced coal as the primary source of home heating, industrial smokestacks were designed to emit at higher altitudes (where dispersion is more rapid), and industries were required to install pollution control equipment.Beginning in the 1950s, a new type of pollution, photochemical smog, became a major concern. Photochemical smog consists of ozone (O3) and other closely related species ("secondary pollutants") that are produced photochemically from directly emitted species, in a process that is driven by sunlight and is accelerated by warm temperatures. This smog is largely the product of gasoline-powered engines (especially automobiles), although coal-fired industry can also generate photochemical smog. The process of photochemical smog formation was first identified by Haagen-Smit and Fox (1954) in association with Los Angeles, a city whose geography makes it particularly susceptible to this type of smog formation. Sulfate aerosols and organic particulates are often produced concurrently with ozone, giving rise to a characteristic milky-white haze associated with this type of air pollution.Today ozone and particulates are recognized as the air pollutants that are most likely to affect human health adversely. In the United States, most major metropolitan areas have periodic air pollution events with ozone in excess of government health standards. Violations of local health standards also occur in major cities in Canada and in much of Europe. Other cities around the world (especially Mexico City) also experience very high ozone levels. In addition to urban-scale events, elevated ozone occurs in region-wide events in the eastern USA and in Western Europe, with excess ozone extending over areas of 1,000 km2 or more. Ozone plumes of similar extent are found in the tropics (especially in Central Africa) at times of high biomass burning (e.g., Jenkins et al., 1997; Chatfield et al., 1998). In some cases ozone associated with biomass burning has been identified at distances up to 104 km from its sources (Schultz et al., 1999).Ozone also has a significant impact on the global troposphere, and ozone chemistry is a major component of global tropospheric chemistry. Global background ozone concentrations are much lower than urban or regional concentrations during pollution events, but there is evidence that the global background has increased as a result of human activities (e.g., Wang and Jacob, 1998; Volz and Kley, 1988). A rise in global background ozone can make the effects of local pollution events everywhere more acute, and can also cause ecological damage in remote locations that are otherwise unaffected by urban pollution. Ozone at the global scale is also related to greenhouse warming.This chapter provides an overview of photochemical smog at the urban and regional scale, focused primarily on ozone and including a summary of information about particulates. It includes the following topics: dynamics and extent of pollution events; health and ecological impacts; relation between ozone and precursor emissions, including hydrocarbons and nitrogen oxides (NOx); sources, composition, and fundamental properties of particulates; chemistry of ozone and related species; methods of interpretation based on ambient measurements; and the connection between air pollution events and the chemistry of the global troposphere. Because there are many similarities between the photochemistry of ozone during pollution events and the chemistry of the troposphere in general, this chapter will include some information about global tropospheric chemistry and the links between urban-scale and global-scale events. Additional treatment of the global troposphere is found in Volume 4 of this work. The chemistry of ozone formation discussed here is also related to topics discussed in greater detail elsewhere in this volume (see Chapters 9.10 and 9.12) and in Volume 4.

Ozone oxidation of oestrogenic active substances in wastewater and drinking water.

PubMed

Baig, S; Hansmann, G; Paolini, B

2008-01-01

Ozone oxidation is proven to be an effective solution for the degradation of selected oestrogenic active substances detected in secondary wastewaters such as beta-oestradiol, oestrone, oestriol, 17-alpha-ethinyloestradiol, mestranol, daidzeine, beta-sitosterol, bisphenol A, norethisterone, 4-tert-octylphenol and 4-iso-nonylphenol, up to their limit of detection. The matrix-effect of wastewater was investigated performing ozone experiments under batch mode and continuous mode using drinking water and a wastewater issued from a local plant both spiked with the non-detected substances. The results obtained indicate that the wastewater matrix greatly affects the kinetics of ozone reaction with these substances but does not really change the related reactivity scale. The ozone dose corresponding to the full conversion of target EDCs consequently increases as their oxidation takes place competing with reactions of background pollutants represented by the COD and DOC content. However, a usual dose close to 12 mg/L was found sufficient to provide high degradation yields for all substances studied while 35% of COD was removed. This is a contribution to the numerous current works focused on technologies able to improve the quality of water discharged from wastewater treatment plants, both considering conventional parameters and emerging contaminants. IWA Publishing 2008.

Photochemical ozone formation from petroleum refinery emissions

NASA Astrophysics Data System (ADS)

Sexton, Ken; Westberg, Hal

Atmospheric emissions from the Marathon oil refinery at Robinson, Illinois were investigated during June and July 1977. Surface and aerial measurements were used to provide an integrated, three dimensional monitoring network. Concentrations of ozone, oxides of nitrogen, sulfur dioxide, methane, carbon dioxide, individual non-methane hydrocarbons and halocarbons were recorded on a routine basis. In addition, meteorological parameters such as wind speed, wind direction, solar radiation and mixing height were also measured. The field monitoring study focused on three major areas: (1) characterization of gaseous components within the refinery effluent, especially nonmethane hydrocarbons and nitrogen oxides; (2) natural sunlight bag irradiation experiments to examine ozone forming potential of refinery emissions and (3) aerial measurements of changes in plume chemistry during the first six to eight hours of transport. Results indicate levels of hydrocarbons and nitrogen oxides were elevated downwind of the refinery. Concentrations within the effluent exceeded background values by as much as 300- and 10-fold, respectively. Irradiations of captured refinery emissions suggest excess photochemical ozone can be produced in the first 6 h, with amounts varying according to NMHC/NO x, ratios and initial NMHC concentrations. Real-time measurements on board the aircraft documented instances of ozone buildup in the refinery plume as it drifted downwind.

Contributions to Future Stratospheric Climate Change: An Idealized Chemistry-Climate Model Sensitivity Study

NASA Technical Reports Server (NTRS)

Hurwitz, M. M.; Braesicke, P.; Pyle, J. A.

2010-01-01

Within the framework of an idealized model sensitivity study, three of the main contributors to future stratospheric climate change are evaluated: increases in greenhouse gas concentrations, ozone recovery, and changing sea surface temperatures (SSTs). These three contributors are explored in combination and separately, to test the interactions between ozone and climate; the linearity of their contributions to stratospheric climate change is also assessed. In a simplified chemistry-climate model, stratospheric global mean temperature is most sensitive to CO2 doubling, followed by ozone depletion, then by increased SSTs. At polar latitudes, the Northern Hemisphere (NH) stratosphere is more sensitive to changes in CO2, SSTs and O3 than is the Southern Hemisphere (SH); the opposing responses to ozone depletion under low or high background CO2 concentrations, as seen with present-day SSTs, are much weaker and are not statistically significant under enhanced SSTs. Consistent with previous studies, the strength of the Brewer-Dobson circulation is found to increase in an idealized future climate; SSTs contribute most to this increase in the upper troposphere/lower stratosphere (UT/LS) region, while CO2 and ozone changes contribute most in the stratosphere and mesosphere.

Coal Markets

EIA Publications

2017-01-01

Summarizes spot coal prices by coal commodity regions (i.e., Central Appalachia (CAP), Northern Appalachia (NAP), Illinois Basin (ILB), Power River Basin (PRB), and Uinta Basin (UIB)) in the United States.

Retrieval of Ozone Column Content from Airborne Sun Photometer Measurements During SOLVE II: Comparison with SAGE III, POAM III,THOMAS and GOME Measurements. Comparison with SAGE 111, POAM 111, TOMS and GOME Measurements

NASA Technical Reports Server (NTRS)

Livingston, J.; Schmid, B.; Russell, P.; Eilers, J.; Kolyer, R.; Redemann, J.; Yee, J.-H.; Trepte, C.; Thomason, L.; Pitts, M.

2003-01-01

During the Second SAGE 111 Ozone Loss and Validation Experiment (SOLVE II), the 14- channel NASA Ames Airborne Trackmg Sunphotometer (AATS-14) was mounted on the NASA DC-8 and successfully measured spectra of total and aerosol optical depth (TOD and AOD) during the sunlit portions of eight science flights. Values of ozone column content above the aircraft have been derived from the AATS-14 data by using a linear least squares method. For each AATS-14 measured TOD spectrum, this method iteratively finds the ozone column content that yields the best match between measured and calculated TOD. The calculations assume the known Chappuis ozone band shape and a three-parameter AOD shape (quadratic in log-log space). Seven of the AATS-14 channels (each employing an interference filter with a nominal full-width at half maximum bandpass of -5 nm) are within the Chappuis band, with center wavelengths between 452.9 nm and 864.5 nm. One channel (604.4 nm) is near the peak, and three channels (499.4, 519.4 and 675.1 nm) have ozone absorption within 30-40% of that at the peak. For the typical DC-8 SOLVE II cruising altitudes of approx. 8-12 km and the background stratospheric aerosol conditions that prevailed during SOLVE 11, absorption of incoming solar radiation by ozone comprised a significant fraction of the aerosol-plus-ozone optical depth measured in the four AATS-14 channels centered between 499.4 and 675.1 nm. Typical AODs above the DC-8 ranged from 0.003-0.008 in these channels. For comparison, an ozone overburden of 0.3 atm-cm (300 DU) translates to ozone optical depths of 0.009,0.014, 0.041, and 0.012, respectively, at these same wavelengths. In this paper, we compare AATS-14 values of ozone column content with temporally and spatially near-coincident values derived from measurements acquired by the Stratospheric Aerosol and Gas Experiment III (SAGE III) and the Polar Ozone and Aerosol Measurement 111 (POAM III) satellite sensors. We also compare AATS-14 ozone retrievals during selected DC-8 latitudinal and longitudinal transects with total column ozone data acquired by the Total Ozone Mapping Spectrometer (TOMS) and the Global Ozone Monitoring Experiment (GOME) satellite sensors. To enable this comparison, the amount of ozone in the column below the aircraft is estimated by combining SAGE and/or POAM data with high resolution, fast response in-situ ozone measurements acquired during the DC-8 ascent at the start of each science flight.

Enhancement of free tropospheric ozone production by deep convection

NASA Technical Reports Server (NTRS)

Pickering, Kenneth E.; Thompson, Anne M.; Scala, John R.; Tao, Wei-Kuo; Simpson, Joanne

1994-01-01

It is found from model simulations of trace gas and meteorological data from aircraft campaigns that deep convection may enhance the potential for photochemical ozone production in the middle and upper troposphere by up to a factor of 60. Examination of half a dozen individual convective episodes show that the degree of enhancement is highly variable. Factors affecting enhancement include boundary layer NO(x) mixing ratios, differences in the strength and structure of convective cells, as well as variation in the amount of background pollution already in the free troposphere.

Contribution of long-range transport to the ozone levels recorded in the Northeast of Portugal

NASA Astrophysics Data System (ADS)

Gama, C.; Nunes, T.; Marques, M. C.; Ferreira, F.

2009-04-01

In the past four years (2004-2007), measurements carried out at Lamas de Olo, the only air quality monitoring background station in the Northeast of Portugal, showed high ozone concentrations (97,7±29,7 g.m-3). This remote site, located in the middle of Alvão Natural Park, in Portugal, 1086 m asl, plays a significant role on the total amount of exceedances registered in the national air quality network. The analysis of the data recorded at this monitoring station revealed an annual cycle of ozone concentrations similar to the ones observed in other background sites of the Northern Hemisphere (Monks, 2000; Vingarzan and Taylor, 2003). This common feature comprises a distinct maximum during spring (peaking during the month of April). Nevertheless it is during the summer that the hourly concentrations are higher, due to the typical atmospheric and meteorological conditions that promote photochemical pollution episodes. Photochemical pollution episodes can be related with production of ozone in a local scale or in a global scale due to the transportation of polluted air masses. For this reason analysing these events is crucial to fully understand the behaviour of ozone in the Northeast of Portugal, in order to adopt the correct long-term policies. With the purpose of studying the influence of long-range transport on the ozone levels recorded at Lamas de Olo, a cluster analysis was performed on 96-hour back trajectories air masses. Different trajectory clusters represent air masses with different source regions of atmospheric pollutants and the influence of these regions on the atmospheric composition at the arrival point (receptor) of the trajectories can therefore be assessed (EMPA, 2008). The back trajectories were simulated 4 times per day, using HYSPLIT model. A "bottom-up" cluster methodology was used to group trajectories into clusters according to their characteristics, for several time periods with similar ozone levels and/or distributions. Ozone average levels were calculated for each cluster and the differences between the groups were validated using the Kruskal-Wallis statistical test. The results have shown a significant influence of the transport path on ozone concentrations, which is more noticeable when the probability of occurring photochemical pollution phenomena is higher. Air masses from Europe (Spain, France, United Kingdom, etc.) generally originate higher ozone levels than the ones arriving from the Atlantic Ocean. This feature shows the role of photochemical production along long-range transport phenomena, and the input of pollutants into air masses, along their path. A more detailed analysis at local/regional scale, supported mainly by an intensive field campaign performed during spring/summer of 2006 in the vicinity of Alvão Natural Park (FOTONET Project), at different altitudes, together with pollutant measurements from rural air quality stations in the north of Portugal and one from Spain (Peñausende) was carried out in order to evaluate the extension of photochemical pollution in the Northeast of Portugal. Ozone concentrations measurements in the region showed a noticeable decrease with altitude, mainly at night. In resume back trajectories based analysis has demonstrated that other countries, mainly Spain, contribute decisively to the ozone levels registered in the station used for this study. Backed on this knowledge we point out towards the need of considering common international policies when dealing with controlling ozone levels in the environment. References: Monks, P. (2000): A review of the observations and origins of the spring ozone maximum. Atmospheric Environment 34, 3545-3561. Vingarzan, R., Taylor, B. (2003): Trend analysis of ground level ozone in the greater Vancouver / Fraser Valley area of British Columbia. Atmospheric Environment 37, 2159-2171. EMPA (2008): Air mass trajectory clustering. Retrieved 01 November 2008 from: http://www.empa.ch/plugin/template/empa/*/63288/—/l=1

GOME Total Ozone and Calibration Error Derived Usign Version 8 TOMS Algorithm

NASA Technical Reports Server (NTRS)

Gleason, J.; Wellemeyer, C.; Qin, W.; Ahn, C.; Gopalan, A.; Bhartia, P.

2003-01-01

The Global Ozone Monitoring Experiment (GOME) is a hyper-spectral satellite instrument measuring the ultraviolet backscatter at relatively high spectral resolution. GOME radiances have been slit averaged to emulate measurements of the Total Ozone Mapping Spectrometer (TOMS) made at discrete wavelengths and processed using the new TOMS Version 8 Ozone Algorithm. Compared to Differential Optical Absorption Spectroscopy (DOAS) techniques based on local structure in the Huggins Bands, the TOMS uses differential absorption between a pair of wavelengths including the local stiucture as well as the background continuum. This makes the TOMS Algorithm more sensitive to ozone, but it also makes the algorithm more sensitive to instrument calibration errors. While calibration adjustments are not needed for the fitting techniques like the DOAS employed in GOME algorithms, some adjustment is necessary when applying the TOMS Algorithm to GOME. Using spectral discrimination at near ultraviolet wavelength channels unabsorbed by ozone, the GOME wavelength dependent calibration drift is estimated and then checked using pair justification. In addition, the day one calibration offset is estimated based on the residuals of the Version 8 TOMS Algorithm. The estimated drift in the 2b detector of GOME is small through the first four years and then increases rapidly to +5% in normalized radiance at 331 nm relative to 385 nm by mid 2000. The lb detector appears to be quite well behaved throughout this time period.

Inflammatory and Repair Pathways Induced in Human Bronchoalveolar Lavage Cells with Ozone Inhalation

PubMed Central

Wong, Hofer; Tenney, Rachel; Chen, Chun; Stiner, Rachel; Balmes, John R.; Paquet, Agnès C.; Arjomandi, Mehrdad

2015-01-01

Background Inhalation of ambient levels of ozone causes airway inflammation and epithelial injury. Methods To examine the responses of airway cells to ozone-induced oxidative injury, 19 subjects (7 with asthma) were exposed to clean air (0ppb), medium (100ppb), and high (200ppb) ambient levels of ozone for 4h on three separate occasions in a climate-controlled chamber followed by bronchoscopy with bronchoalveolar lavage (BAL) 24h later. BAL cell mRNA expression was examined using Affymetrix GeneChip Microarray. The role of a differentially expressed gene (DEG) in epithelial injury was evaluated in an in vitro model of injury [16HBE14o- cell line scratch assay]. Results Ozone exposure caused a dose-dependent up-regulation of several biologic pathways involved in inflammation and repair including chemokine and cytokine secretion, activity, and receptor binding; metalloproteinase and endopeptidase activity; adhesion, locomotion, and migration; and cell growth and tumorigenesis regulation. Asthmatic subjects had 1.7- to 3.8-fold higher expression of many DEGs suggestive of increased proinflammatory and matrix degradation and remodeling signals. The most highly up-regulated gene was osteopontin, the protein level of which in BAL fluid increased in a dose-dependent manner after ozone exposure. Asthmatic subjects had a disproportionate increase in non-polymerized osteopontin with increasing exposure to ozone. Treatment with polymeric, but not monomeric, osteopontin enhanced the migration of epithelial cells and wound closure in an α9β1 integrin-dependent manner. Conclusions Expression profiling of BAL cells after ozone exposure reveals potential regulatory genes and pathways activated by oxidative stress. One DEG, osteopontin, promotes epithelial wound healing in an in vitro model of injury. PMID:26035830

Simulating ozone concentrations using precursor emission inventories in Delhi - National Capital Region of India

NASA Astrophysics Data System (ADS)

Sharma, Sumit; Khare, Mukesh

2017-02-01

This study simulates ground level ozone concentrations in a heavily populated and polluted National Capital Region (NCR- Delhi) in India. Multi-sectoral emission inventories of ozone precursors are prepared at a high resolution of 4 × 4 km2 for the whole region covering the capital city of Delhi along with other surrounding towns and rural regions in NCR. Emission inventories show that transport sector accounts for 55% of the total NOx emissions, followed by power plants (23%) and diesel generator sets (7%). In NMVOC inventories, transport sector again accounts for 33%, followed by evaporative emissions released from solvent use and fuel handling activities (30%), and agricultural residue burning (28%). Refuse burning contributes to 73% of CO emissions mainly due to incomplete combustion, followed by agricultural residue burning (14%). These emissions are spatially and temporally distributed across the study domain and are fed into the WRF-CMAQ models to predict ozone concentrations for the year 2012. Model validations are carried out with the observed values at different monitoring stations in Delhi. The performance of the models over various metrics used for evaluation was found to be satisfactory. Summers and post-monsoon seasons were better simulated than monsoon and winter seasons. Simulations have shown higher concentrations of ozone formation during summers and lesser during winters and monsoon seasons, mainly due to varying solar radiation affecting photo-chemical activities. Ozone concentrations are observed lower at those locations where NOx emissions are higher, and concentrations increase close to the boundary of study domain when compared to the center of Delhi city. Downwind regions to Delhi are influenced by the ozone formed due to plume of precursor emissions released from Delhi. Considering significant background contributions, regional scale controls are required for reducing ozone in NCR.

Introduction to the SONEX (Subsonic Assessment Ozone and Nitrogen Oxides Experiment) and POLINAT-2 (Pollution from Aircraft Emissions in the North Atlantic Flight Corridor) Special Issue

NASA Technical Reports Server (NTRS)

Thompson, Anne M.; Singh, Hanwant B.; Schlager, Hans; Einaudi, Franco (Technical Monitor)

2000-01-01

Emissions of atmospheric species from the engines of subsonic aircraft at cruise altitude (roughly, above seven kilometers) are of concern to scientists, the aviation industry and policymakers for two reasons. First, water vapor, soot and sulfur oxides, and related heterogeneous processes, may modify clouds and aerosols enough to perturb radiative forcing in the UT/LS (upper troposphere/lower stratosphere). A discussion of these phenomena appears in Chapter 3 of the IPCC Aviation Assessment (1999). An airborne campaign conducted to evaluate aviation effects on contrail, cirrus and cloud formation, is described in Geophysical Research Letters. The second concern arises from subsonic aircraft emissions of nitrogen oxides (NO + NO2 = NO(sub x)), CO, and hydrocarbons. These species may add to the background mixture of photochemically reactive species that form ozone. In the UT/LS, ozone is a highly effective greenhouse gas. The impacts of subsonic aircraft emissions on tropospheric NO(sub x) and ozone budgets have been studied with models that focus on UT chemistry [e.g. see discussions of individual models in Brasseur et al., 1998; Friedl et al., 1997; IPCC, 1999]. Depending on the model used, projected increases in the global subsonic aircraft fleet from 1992 to 2015 will lead to a 50-100 pptv increase in UT/LS NO. at 12 km (compared to 50-150 pptv background) in northern hemisphere midlatitudes. The corresponding 12-km ozone increase is 7-11 ppbv, or 5-10% (Chapter 4 in IPCC, 1999). Two major sources of uncertainties in model estimates of aviation effects are: (1) the often limited degree to which global models - the scale required to evaluate aircraft emissions - realistically simulate atmospheric transport and other physical processes; (2) limited UT/LS observations of trace gases with which to evaluate model performance. In response to the latter deficiency, a number of airborne campaigns aimed at elucidating the effect of aircraft on atmospheric nitrogen oxides and ozone were performed between 1990 and 1996 (see descriptions in Friedl et al., 1997; Brasseur et al., 1998).

On the variability of tropospheric ozone in the Tropical Eastern Pacific and its impact on the oxidizing capacity

NASA Astrophysics Data System (ADS)

Saiz-Lopez, A.; Gomez Martin, J.; Hay, T.; Mahajan, A.; Ordoñez, C.; Parrondo Sempere, M.; Gil, M. J.; Agama Reyes, M.; Paredes Mora, J.; Voemel, H.

2012-12-01

Observations of surface ozone, NOx and meteorological variables were made during two ground based field campaigns in the Eastern Pacific marine boundary layer (MBL). The first study was PIQUERO (Primera Investigación de la Química, Evolución y Reparto de Ozono), running from September 2000 to July 2001 in parallel to the Southern Hemisphere ADditional OZonesondes (SHADOZ) in the Galápagos Islands. The second study is the Climate and HAlogen Reactivity tropicaL EXperiment (CHARLEX), running from September 2010 to present. These long-term, high frequency, measurements enable a detailed description of the daily, monthly, seasonal and interannual variability of ozone and help to constrain the MBL and lower free troposphere (FT) ozone budget. In the Equatorial Eastern Pacific "cold season" (August - October), net ozone photochemical destruction of ~ 2 ppb day-1 occurs in the MBL (~30% due to halogens, and the rest to HOx). Ozone recovers by entrainment from aloft at night. The monthly baseline is set by the tropical instability waves (TIW), which also impact the ozone concentration in the lower FT. In the cold phase of the TIWs the MBL is stratified and, apart from higher surface ozone, it may also contain an upper drier layer with higher ozone between ~ 500 m and the main inversion at ~1 km. In the warm phase the buoyant MBL expands upwards (as much as 500 m) and poor ozone air reaches the FT. As the system shifts to the warm season (February- April), the TIWs stop and the sea becomes warmer, increasing evaporation and reducing ozone. The inversion is pushed upwards and finally disappears or becomes very weak. Surface ozone is so low that even at the low background NOx levels observed ozone production balances photochemical destruction, so the daily profile is flat (observed local effects in the populated areas of Galapagos are discussed). In February Galapagos is almost in the doldrums because the Inter-Tropical Convergence Zone (ITCZ) shifts south. In this situation, air convected at the ITZC is advected at different heights in the FT over Galapagos, so the entrainment of air from the FT does not replenish MBL ozone, explaining the low seasonal minimum. An important aspect of the marked ozone seasonal cycle is the impact on OH. levels. The consequences of this for the oxidizing capacity of the lower atmosphere are discussed.

Pyrosequencing analysis yields comprehensive assessment of microbial communities in pilot-scale two-stage membrane biofilm reactors.

PubMed

Ontiveros-Valencia, Aura; Tang, Youneng; Zhao, He-Ping; Friese, David; Overstreet, Ryan; Smith, Jennifer; Evans, Patrick; Rittmann, Bruce E; Krajmalnik-Brown, Rosa

2014-07-01

We studied the microbial community structure of pilot two-stage membrane biofilm reactors (MBfRs) designed to reduce nitrate (NO3(-)) and perchlorate (ClO4(-)) in contaminated groundwater. The groundwater also contained oxygen (O2) and sulfate (SO4(2-)), which became important electron sinks that affected the NO3(-) and ClO4(-) removal rates. Using pyrosequencing, we elucidated how important phylotypes of each "primary" microbial group, i.e., denitrifying bacteria (DB), perchlorate-reducing bacteria (PRB), and sulfate-reducing bacteria (SRB), responded to changes in electron-acceptor loading. UniFrac, principal coordinate analysis (PCoA), and diversity analyses documented that the microbial community of biofilms sampled when the MBfRs had a high acceptor loading were phylogenetically distant from and less diverse than the microbial community of biofilm samples with lower acceptor loadings. Diminished acceptor loading led to SO4(2-) reduction in the lag MBfR, which allowed Desulfovibrionales (an SRB) and Thiothrichales (sulfur-oxidizers) to thrive through S cycling. As a result of this cooperative relationship, they competed effectively with DB/PRB phylotypes such as Xanthomonadales and Rhodobacterales. Thus, pyrosequencing illustrated that while DB, PRB, and SRB responded predictably to changes in acceptor loading, a decrease in total acceptor loading led to important shifts within the "primary" groups, the onset of other members (e.g., Thiothrichales), and overall greater diversity.

Periosteal chondrosarcoma: a histopathological and molecular analysis of a rare chondrosarcoma subtype.

PubMed

Cleven, Arjen H G; Zwartkruis, Evita; Hogendoorn, Pancras C W; Kroon, Herman M; Briaire-de Bruijn, Inge; Bovée, Judith V M G

2015-10-01

Periosteal chondrosarcoma is a rare, malignant cartilage-forming neoplasm originating from the periosteal surface of bone. We collected 38 cases from the archives of the Netherlands Committee on Bone Tumours, with the aim of studying histological features and evaluating the involvement of isocitrate dehydrogenase 1 (IDH1), EXT, Wnt/β-catenin, the pRB pathway (CDK4 and p16), and the TP53 pathway (p53 and MDM2). Histology showed a moderately cellular matrix with mucoid-myxoid changes and, in 42% of cases, formation of a neocortex. Occasional intramedullary extension (26%) and subsequent host bone entrapment (40%) were seen. Histological grading revealed grade 1 (53%) and grade 2 (45%). The EXT1 protein was normally expressed, and mutations in IDH1 were observed in only 15% of cases. pRb signalling was deregulated by loss of p16 expression in 50% of cases, and Wnt signalling was lost in 89%. No alterations were found in CDK4, p53, or MDM2. We report the first large histological and molecular study on periosteal chondrosarcoma showing that histopathological examination and molecular aberrations do not predict prognosis. Although the mutation frequency of IDH1 was low, we confirm the supposed relationship with central chondrosarcoma. Moreover, we identify loss of canonical Wnt signalling and deregulation of pRb signalling as possible events contributing to its histogenesis. © 2015 John Wiley & Sons Ltd.

Post-transcriptional gene expression control by NANOS is up-regulated and functionally important in pRb-deficient cells

PubMed Central

Miles, Wayne O; Korenjak, Michael; Griffiths, Lyra M; Dyer, Michael A; Provero, Paolo; Dyson, Nicholas J

2014-01-01

Inactivation of the retinoblastoma tumor suppressor (pRb) is a common oncogenic event that alters the expression of genes important for cell cycle progression, senescence, and apoptosis. However, in many contexts, the properties of pRb-deficient cells are similar to wild-type cells suggesting there may be processes that counterbalance the transcriptional changes associated with pRb inactivation. Therefore, we have looked for sets of evolutionary conserved, functionally related genes that are direct targets of pRb/E2F proteins. We show that the expression of NANOS, a key facilitator of the Pumilio (PUM) post-transcriptional repressor complex, is directly repressed by pRb/E2F in flies and humans. In both species, NANOS expression increases following inactivation of pRb/RBF1 and becomes important for tissue homeostasis. By analyzing datasets from normal retinal tissue and pRb-null retinoblastomas, we find a strong enrichment for putative PUM substrates among genes de-regulated in tumors. These include pro-apoptotic genes that are transcriptionally down-regulated upon pRb loss, and we characterize two such candidates, MAP2K3 and MAP3K1, as direct PUM substrates. Our data suggest that NANOS increases in importance in pRb-deficient cells and helps to maintain homeostasis by repressing the translation of transcripts containing PUM Regulatory Elements (PRE). PMID:25100735

Post-transcriptional gene expression control by NANOS is up-regulated and functionally important in pRb-deficient cells.

PubMed

Miles, Wayne O; Korenjak, Michael; Griffiths, Lyra M; Dyer, Michael A; Provero, Paolo; Dyson, Nicholas J

2014-10-01

Inactivation of the retinoblastoma tumor suppressor (pRb) is a common oncogenic event that alters the expression of genes important for cell cycle progression, senescence, and apoptosis. However, in many contexts, the properties of pRb-deficient cells are similar to wild-type cells suggesting there may be processes that counterbalance the transcriptional changes associated with pRb inactivation. Therefore, we have looked for sets of evolutionary conserved, functionally related genes that are direct targets of pRb/E2F proteins. We show that the expression of NANOS, a key facilitator of the Pumilio (PUM) post-transcriptional repressor complex, is directly repressed by pRb/E2F in flies and humans. In both species, NANOS expression increases following inactivation of pRb/RBF1 and becomes important for tissue homeostasis. By analyzing datasets from normal retinal tissue and pRb-null retinoblastomas, we find a strong enrichment for putative PUM substrates among genes de-regulated in tumors. These include pro-apoptotic genes that are transcriptionally down-regulated upon pRb loss, and we characterize two such candidates, MAP2K3 and MAP3K1, as direct PUM substrates. Our data suggest that NANOS increases in importance in pRb-deficient cells and helps to maintain homeostasis by repressing the translation of transcripts containing PUM Regulatory Elements (PRE). © 2014 The Authors.

Remediation of lead and cadmium from simulated groundwater in loess region in northwestern China using permeable reactive barrier filled with environmentally friendly mixed adsorbents.

PubMed

Fan, Chunhui; Gao, Yalin; Zhang, Yingchao; Dong, Wanqing; Lai, Miao

2018-01-01

Permeable reactive barrier (PRB) is potentially effective for groundwater remediation, especially using environmentally friendly mixed fillers in representative areas, such as semi-arid loess region in northwestern China. The mixed materials, including corn straw (agricultural wastes), fly ash (industrial wastes), zeolite synthesized from fly ash (reutilized products), and iron-manganese nodule derived from loess (materials with regional characteristics) in northwestern China, were chosen as PRB media to reduce the contents of lead and cadmium in simulated groundwater. A series of lab-scale column experiments were investigated, and the response surface methodology (RSM) was used to optimize the working process; Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscope (SEM) were applied to further reveal the reaction mechanism. It shows that the purification efficiencies are more acceptable when the concentrations of lead and cadmium are approximately 7 and 0.7 mg/L, respectively, at 25 °C in weakly acidic solution, and functional groups of -OH and C=C play an important role for contaminants removal. The mixed adsorbents used are effective to remove lead and cadmium in groundwater. This is the first report on the removal of lead and cadmium from groundwater in loess region in northwestern China using PRB filled with environmentally friendly mixed adsorbents.

Identifying potential effects of climate change on the development of water resources in Pinios River Basin, Central Greece

NASA Astrophysics Data System (ADS)

Arampatzis, G.; Panagopoulos, A.; Pisinaras, V.; Tziritis, E.; Wendland, F.

2018-05-01

The aim of the present study is to assess the future spatial and temporal distribution of precipitation and temperature, and relate the corresponding change to water resources' quantitative status in Pinios River Basin (PRB), Thessaly, Greece. For this purpose, data from four Regional Climate Models (RCMs) for the periods 2021-2100 driven by several General Circulation Models (GCMs) were collected and bias-correction was performed based on linear scaling method. The bias-correction was made based on monthly precipitation and temperature data collected for the period 1981-2000 from 57 meteorological stations in total. The results indicate a general trend according to which precipitation is decreasing whilst temperature is increasing to an extent that varies depending on each particular RCM-GCM output. On the average, annual precipitation change for the period 2021-2100 was about - 80 mm, ranging between - 149 and + 35 mm, while the corresponding change for temperature was 2.81 °C, ranging between 1.48 and 3.72 °C. The investigation of potential impacts to the water resources demonstrates that water availability is expected to be significantly decreased in the already water-stressed PRB. The water stresses identified are related to the potential decreasing trend in groundwater recharge and the increasing trend in irrigation demand, which constitutes the major water consumer in PRB.

Defective heat shock factor 1 inhibits the growth of fibrosarcoma derived from simian virus 40/T antigen-transformed MEF cells

PubMed Central

JIANG, QIYING; ZHANG, ZHI; LI, SHULIAN; WANG, ZHAOYANG; MA, YUANFANG; HU, YANZHONG

2015-01-01

Heat shock factor 1 (Hsf1) serves an important role in regulating the proliferation of human tumor cell lines in vitro and tissue specific tumorigenesis in certain mouse models. However, its role in viral-oncogenesis remains to be fully elucidated. In the current study, the role of Hsf1 in fibroblastoma derived from simian virus 40/T antigen (SV40/TAG)-transformed mouse embryonic fibroblast (MEF) cell lines was investigated. Knockout of Hsf1 inhibited MEF cell proliferation in vitro and fibroblastoma growth and metastasis to the lungs in vivo in nude mice. Knockout of Hsf1 increased the protein expression levels of p53 and phosphorylated retinoblastoma protein (pRb), however reduced the expression of heat shock protein 25 (Hsp25) in addition to the expression of the angiogenesis markers vascular endothelial growth factor, cluster of differentiation 34 and factor VIII related antigen. Furthermore, immunoprecipitation indicated that knockout of Hsf1 inhibited the association between SV40/TAG and p53 or pRb. These data suggest that Hsf1 is involved in the regulation of SV40/TAG-derived fibroblastoma growth and metastasis by modulating the association between SV40/TAG and tumor suppressor p53 and pRb. The current study provides further evidence that Hsf1 may be a novel therapeutic target in the treatment of cancer. PMID:26352782

Papillomavirus E7 protein binding to the retinoblastoma protein is not required for viral induction of warts.

PubMed Central

Defeo-Jones, D; Vuocolo, G A; Haskell, K M; Hanobik, M G; Kiefer, D M; McAvoy, E M; Ivey-Hoyle, M; Brandsma, J L; Oliff, A; Jones, R E

1993-01-01

Human papillomaviruses (HPVs) are the etiologic agents responsible for benign epithelial proliferative disorders including genital warts and are a contributory factor in the pathogenesis of cervical cancer. HPVs demonstrate strict species and cell-type specificity, which is manifested by the inability of these viruses to induce disease in any species other than humans. The natural history of HPV infection in humans is closely mimicked by cottontail rabbit papillomavirus (CRPV) infection in domestic laboratory rabbits. The CRPV E7 gene is known to play an essential role in virus-mediated induction of papillomas. We now show by mutational analysis that the CRPV E7 protein's biochemical and biological properties, including binding to the retinoblastoma suppressor protein (pRB), transcription factor E2F transactivation of the adenovirus E2 promoter, disruption of pRB-E2F complexes, and cellular transformation as measured by growth in soft agar, mimic those of the HPV E7 protein. Intradermal injection of CRPV DNA lacking E7 gene sequences critical for the binding of the CRPV E7 protein to pRB induced papillomas in rabbits. These studies indicate that E7 protein binding to pRB is not required in the molecular pathogenesis of virally induced warts and suggest that other properties intrinsic to the E7 protein are necessary for papilloma formation. Images PMID:8380462

Seasonal water chemistry variability in the Pangani River basin, Tanzania.

PubMed

Selemani, Juma R; Zhang, Jing; Muzuka, Alfred N N; Njau, Karoli N; Zhang, Guosen; Maggid, Arafa; Mzuza, Maureen K; Jin, Jie; Pradhan, Sonali

2017-11-01

The stable isotopes of δ 18 O, δ 2 H, and 87 Sr/ 86 Sr and dissolved major ions were used to assess spatial and seasonal water chemistry variability, chemical weathering, and hydrological cycle in the Pangani River Basin (PRB), Tanzania. Water in PRB was NaHCO 3 type dominated by carbonate weathering with moderate total dissolved solids. Major ions varied greatly, increasing from upstream to downstream. In some stations, content of fluoride and sodium was higher than the recommended drinking water standards. Natural and anthropogenic factors contributed to the lowering rate of chemical weathering; the rate was lower than most of tropical rivers. The rate of weathering was higher in Precambrian than volcanic rocks. 87 Sr/ 86 Sr was lower than global average whereas concentration of strontium was higher than global average with mean annual flux of 0.13 × 10 6  mol year -1 . Evaporation and altitude effects have caused enrichment of δ 18 O and δ 2 H in dry season and downstream of the river. Higher d-excess value than global average suggests that most of the stations were supplied by recycled moisture. Rainfall and groundwater were the major sources of surface flowing water in PRB; nevertheless, glacier from Mt. Kilimanjaro has insignificant contribution to the surface water. We recommend measures to be taken to reduce the level of fluoride and sodium before domestic use.

Synoptic meteorological conditions associated with high spring and summer ozone levels at a rural site in the Eastern Mediterranean

NASA Astrophysics Data System (ADS)

Kalabokas, Pavlos; Repapis, Christos; Mihalopoulos, Nikos; Zerefos, Christos

2017-04-01

For the identification of the nature of spring and summertime ozone episodes, rural ozone measurements from the Eastern Mediterranean station of Finokalia-Crete, Greece during the first 4-year period of its record (1998-2001) have been analyzed with emphasis on periods of high ozone concentrations, according to the daily variation of the afternoon (12:00 - 18:00) ozone values. For the 7% highest spring and summertime ozone episodes composite NOAA/ESRL reanalysis maps of various meteorological parameters and/or their anomalies (geopotential height, specific humidity, vertical wind velocity omega, vector wind speed and temperature) have been examined together with their corresponding HYSPLIT back trajectories. This work is a continuation of a previous first approach regarding summer highest and lowest surface ozone episodes in Finokalia and other Central and Eastern Mediterranean stations (Kalabokas et al., 2008), which is now extended to more meteorological parameters and higher pressure levels. The results show that the examined synoptic meteorological condition during springtime ozone episodes over the Eastern Mediterranean station of Finokalia are quite similar with those conditions during high ozone springtime episodes observed at rural stations over the Western Mediterranean (Kalabokas et al., 2016). On the other hand the summer time synoptic conditions corresponding to highest surface ozone episodes at Finokalia are comparable with the conditions encountered during highest ozone episodes in the lower troposphere following analysis of MOZAIC vertical profiles over the Aegean Sea and the Eastern Mediterranean (Kalabokas et al., 2015 and references therein). During the highest ozone episodes, for both examined seasons, the transport of tropospheric ozone-rich air masses through atmospheric subsidence influences significantly the boundary layer and surface ozone concentrations. In particular, the geographic areas with observed tropospheric subsidence seem to be the transition regions between high and low pressure synoptic meteorological systems. References Kalabokas, P. D., Mihalopoulos, N., Ellul, R., Kleanthous, S., and Repapis, C. C., 2008. An investigation of the meteorological and photochemical factors influencing the background rural and marine surface ozone levels in the Central and Eastern Mediterranean, Atmos. Environ., 42, 7894-7906. Kalabokas P. D., Thouret V., Cammas J.-P., Volz-Τhomas A., Boulanger D., Repapis C.C., 2015. The geographical distribution of meteorological parameters associated with high and low summer ozone levels in the lower troposphere and the boundary layer over the eastern Mediterranean (Cairo case), Tellus B, 67, 27853, http://dx.doi.org/10.3402/tellusb.v67.27853. Kalabokas P., J. Hjorth, G. Foret, G. Dufour, M. Eremenko, G. Siour, J. Cuesta, M. Beekmann, 2016. An investigation on the origin of regional spring time ozone episodes in the Western Mediterranean and Central Europe. Atmos. Chem. Phys. Discuss., doi:10.5194/acp-2016-615.

Sources of Springtime Tropospheric Ozone Over North China: A Modeling Analysis of Ozonesonde and Satellite Observations

NASA Astrophysics Data System (ADS)

Liu, H.; Chan, C.; Huang, J.; Zhang, Y.; Choi, H.; Crawford, J. H.; Considine, D. B.; Zheng, X.; Oltmans, S. J.; Liu, S. C.; Zhang, L.; Liu, X.; Thouret, V.

2012-12-01

Tropospheric ozone concentrations and emissions of NOx have both increased significantly over China as a result of rapid industrialization during the past decade. These trends degrade local and regional air quality and have important effects on background tropospheric ozone and surface ozone over downwind North Pacific and North America. In-situ observations of tropospheric ozone over China are therefore essential to testing and improving our understanding of the impact of Asian anthropogenic (versus natural) emissions and various chemical, physical, and dynamical processes on both regional and global tropospheric ozone. Despite their critical importance, in-situ observations of tropospheric ozone profiles over China have been few and far between in most of the country. To investigate the ensemble of processes that control the distribution, variability, and sources of springtime tropospheric ozone over China and its surrounding regions, an intensive ozonesonde sounding campaign, called Transport of Air Pollutants and Tropospheric Ozone over China (TAPTO-China), was conducted at nine locations across China in the springs of 2004 (South China) and 2005 (North China). In this paper, we use a global 3-D model of tropospheric chemistry (GEOS-Chem) to examine the characteristics of distribution and variability and quantify various sources of tropospheric ozone over North China by analysis of intensive ozonesonde data obtained at four stations in North / Northwest China during the second phase of TAPTO-China (April-May 2005). These four stations include Xining (36.43N, 101.45E), Beijing (39.80N, 116.18E), Longfengshan (44.44N, 127.36E), and Aletai (47.73N, 88.08E). We drive GEOS-Chem with two sets of assimilated meteorological observations (GEOS-4 and GEOS-5) from the Goddard Earth Observing System (GEOS) of the NASA Global Modeling and Assimilation Office (GAMO), allowing us to examine the impacts of variability in meteorology. We show that the observed tropospheric ozone mixing ratios exhibit strong spatio-temporal variability. The model generally simulates well the ozonesonde observations but tends to underestimate ozone in the upper troposphere over Beijing and Longfengshan. We find that Asian fossil fuel emissions, stratospheric ozone, African lightning NOx emissions, as well as intercontinental transport are the main contributors to tropospheric ozone over North China in spring. While the lower-tropospheric ozone is largely influenced by Asian fossil fuel emissions (except over Aletai, Northwest China), lightning NOx emissions have a larger impact on the upper-tropospheric ozone than Asian fossil fuel emissions (except over Longfengshan, Northeast China). Model simulations suggest that the European fossil fuel emissions contribute more to the lower-tropospheric ozone over Aletai than the Asian fossil fuel emissions. We will also show that tropospheric ozone measurements by Tropospheric Emission Spectrometer (TES) aboard the NASA EOS Aura satellite can be used to study tropospheric ozone variability at Xining.

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

Haque, Rizwanul; Umstead, Todd M.; Ponnuru, Padmavathi

Millions are exposed to ozone levels above recommended limits, impairing lung function, causing epithelial damage and inflammation, and predisposing some individuals to pneumonia, asthma, and other lung conditions. Surfactant protein-A (SP-A) plays a role in host defense, the regulation of inflammation, and repair of tissue damage. We tested the hypothesis that the lungs of SP-A(-/-) (KO) mice are more susceptible to ozone-induced damage. We compared the effects of ozone on KO and wild type (WT) mice on the C57BL/6 genetic background by exposing them to 2 parts/million of ozone for 3 or 6 h and sacrificing them 0, 4, andmore » 24 h later. Lungs were subject to bronchoalveolar lavage (BAL) or used to measure endpoints of oxidative stress and inflammation. Despite more total protein in BAL of KO mice after a 3 h ozone exposure, WT mice had increased oxidation of protein and had oxidized SP-A dimers. In KO mice there was epithelial damage as assessed by increased LDH activity and there was increased phospholipid content. In WT mice there were more BAL PMNs and elevated macrophage inflammatory protein (MIP)-2 and monocyte chemoattractant protein (MCP)-1. Changes in MIP-2 and MCP-1 were observed in both KO and WT, however mRNA levels differed. In KO mice MIP-2 mRNA levels changed little with ozone, but in WT levels they were significantly increased. In summary, several aspects of the inflammatory response differ between WT and KO mice. These in vivo findings appear to implicate SP-A in regulating inflammation and limiting epithelial damage in response to ozone exposure.« less

Atmospheric Impacts of Emissions from Oil and Gas Development in the Uintah Basin, Utah, USA

NASA Astrophysics Data System (ADS)

Helmig, D.; Boylan, P. J.; Hueber, J.; Van Dam, B. A.; Mauldin, L.; Parrish, D. D.

2012-12-01

In the Uintah Basin in northeast Utah, USA, surface ozone levels during winter months have approached and on occasion exceeded the US National Ambient Air Quality Standard (NAAQS). Emissions from the extensive oil and gas exploration in this region are suspected to be the cause of these ozone episodes; however emission rates and photochemical processes are uncertain. During February 2012 continuous surface measurements and vertical profiling from a tethered balloon platform at the Horsepool site yielded high resolution boundary layer profile data on ozone and ozone precursor compounds, i.e. nitrogen oxides and volatile organic compounds as well as methane. Findings from this study were: 1. Surface ozone during the study period, which had no snow cover, did not exceed the NAAQS. 2. Nitrogen oxides varied from 1-50 ppbv pointing towards significant emission sources, likely from oil and gas operations. 3. Methane concentrations were elevated, reaching up to ~10 times its Northern Hemisphere (NH) atmospheric background. 3. Light non-methane hydrocarbons (NMHC) constituted the main fraction of volatile organic compounds. NMHC concentrations were highly elevated, exceeding levels seen in urban areas. 4. Ozone, methane, NOx and VOC showed distinct diurnal cycles, with large concentration increases seen at night, except for ozone, which showed the opposite behavior. 5. During nighttime concentrations of NOx, NMHC, and methane built up near the surface to levels that were much higher than their daytime concentrations. 6. Comparing NMHC to methane concentrations indicates a mass flux ratio of ~30% for total VOC/methane emissions for the Uintah Basin.

Effects of Elevated Tropospheric Ozone Concentration on the Bacterial Community in the Phyllosphere and Rhizoplane of Rice.

PubMed

Ueda, Yoshiaki; Frindte, Katharina; Knief, Claudia; Ashrafuzzaman, Md; Frei, Michael

2016-01-01

Microbes constitute a vital part of the plant holobiont. They establish plant-microbe or microbe-microbe associations, forming a unique microbiota with each plant species and under different environmental conditions. These microbial communities have to adapt to diverse environmental conditions, such as geographical location, climate conditions and soil types, and are subjected to changes in their surrounding environment. Elevated ozone concentration is one of the most important aspects of global change, but its effect on microbial communities living on plant surfaces has barely been investigated. In the current study, we aimed at elucidating the potential effect of elevated ozone concentrations on the phyllosphere (aerial part of the plant) and rhizoplane (surface of the root) microbiota by adopting next-generation 16S rRNA amplicon sequencing. A standard japonica rice cultivar Nipponbare and an ozone-tolerant breeding line L81 (Nipponbare background) were pre-grown in a greenhouse for 10 weeks and then exposed to ozone at 85 ppb for 7 h daily for 30 days in open top chambers. Microbial cells were collected from the phyllosphere and rhizoplane separately. The treatment or different genotypes did not affect various diversity indices. On the other hand, the relative abundance of some bacterial taxa were significantly affected in the rhizoplane community of ozone-treated plants. A significant effect of ozone was detected by homogeneity of molecular variance analysis in the phyllosphere, meaning that the community from ozone-treated phyllosphere samples was more variable than those from control plants. In addition, a weak treatment effect was observed by clustering samples based on the Yue and Clayton and weighted UniFrac distance matrices among samples. We therefore conclude that the elevated ozone concentrations affected the bacterial community structure of the phyllosphere and the rhizosplane as a whole, even though this effect was rather weak and did not lead to changes of the function of the communities.

Effects of Elevated Tropospheric Ozone Concentration on the Bacterial Community in the Phyllosphere and Rhizoplane of Rice

PubMed Central

Ueda, Yoshiaki; Frindte, Katharina; Knief, Claudia; Ashrafuzzaman, Md; Frei, Michael

2016-01-01

Microbes constitute a vital part of the plant holobiont. They establish plant-microbe or microbe-microbe associations, forming a unique microbiota with each plant species and under different environmental conditions. These microbial communities have to adapt to diverse environmental conditions, such as geographical location, climate conditions and soil types, and are subjected to changes in their surrounding environment. Elevated ozone concentration is one of the most important aspects of global change, but its effect on microbial communities living on plant surfaces has barely been investigated. In the current study, we aimed at elucidating the potential effect of elevated ozone concentrations on the phyllosphere (aerial part of the plant) and rhizoplane (surface of the root) microbiota by adopting next-generation 16S rRNA amplicon sequencing. A standard japonica rice cultivar Nipponbare and an ozone-tolerant breeding line L81 (Nipponbare background) were pre-grown in a greenhouse for 10 weeks and then exposed to ozone at 85 ppb for 7 h daily for 30 days in open top chambers. Microbial cells were collected from the phyllosphere and rhizoplane separately. The treatment or different genotypes did not affect various diversity indices. On the other hand, the relative abundance of some bacterial taxa were significantly affected in the rhizoplane community of ozone-treated plants. A significant effect of ozone was detected by homogeneity of molecular variance analysis in the phyllosphere, meaning that the community from ozone-treated phyllosphere samples was more variable than those from control plants. In addition, a weak treatment effect was observed by clustering samples based on the Yue and Clayton and weighted UniFrac distance matrices among samples. We therefore conclude that the elevated ozone concentrations affected the bacterial community structure of the phyllosphere and the rhizosplane as a whole, even though this effect was rather weak and did not lead to changes of the function of the communities. PMID:27643794

Proposed standardized definitions for vertical resolution and uncertainty in the NDACC lidar ozone and temperature algorithms - Part 2: Ozone DIAL uncertainty budget

NASA Astrophysics Data System (ADS)

Leblanc, Thierry; Sica, Robert J.; van Gijsel, Joanna A. E.; Godin-Beekmann, Sophie; Haefele, Alexander; Trickl, Thomas; Payen, Guillaume; Liberti, Gianluigi

2016-08-01

A standardized approach for the definition, propagation, and reporting of uncertainty in the ozone differential absorption lidar data products contributing to the Network for the Detection for Atmospheric Composition Change (NDACC) database is proposed. One essential aspect of the proposed approach is the propagation in parallel of all independent uncertainty components through the data processing chain before they are combined together to form the ozone combined standard uncertainty. The independent uncertainty components contributing to the overall budget include random noise associated with signal detection, uncertainty due to saturation correction, background noise extraction, the absorption cross sections of O3, NO2, SO2, and O2, the molecular extinction cross sections, and the number densities of the air, NO2, and SO2. The expression of the individual uncertainty components and their step-by-step propagation through the ozone differential absorption lidar (DIAL) processing chain are thoroughly estimated. All sources of uncertainty except detection noise imply correlated terms in the vertical dimension, which requires knowledge of the covariance matrix when the lidar signal is vertically filtered. In addition, the covariance terms must be taken into account if the same detection hardware is shared by the lidar receiver channels at the absorbed and non-absorbed wavelengths. The ozone uncertainty budget is presented as much as possible in a generic form (i.e., as a function of instrument performance and wavelength) so that all NDACC ozone DIAL investigators across the network can estimate, for their own instrument and in a straightforward manner, the expected impact of each reviewed uncertainty component. In addition, two actual examples of full uncertainty budget are provided, using nighttime measurements from the tropospheric ozone DIAL located at the Jet Propulsion Laboratory (JPL) Table Mountain Facility, California, and nighttime measurements from the JPL stratospheric ozone DIAL located at Mauna Loa Observatory, Hawai'i.

A Geochemical Comparison of the Northern Peninsular Ranges Batholith in Southern California and the Coastal Batholith in Southern Peru

NASA Astrophysics Data System (ADS)

Clausen, B. L.; Martínez Ardila, A. M.; Morton, D. M.

2010-12-01

An extensive geochemical data set from the northern Peninsular Ranges Batholith (PRB) in southern California is compared and contrasted with the Arequipa segment of the Peruvian Coastal Batholith, including new granitoid samples recently collected near Ica (14°S, 76°W). The data include major and trace elements and Sr isotope ratios. This is part of an on-going study of subduction-related magmatism to refine a petrogenetic model of crust formation at plate boundaries, with a particular interest in the role of magma mixing. Research in the northern PRB suggests that continental crust is formed in several cycles: (1) mantle melting to give mafic volcanics and gabbroic intrusives, (2) basalt/gabbro melting to give felsic granitoids uncontaminated by continental crust and having low initial 87Sr/86Sr (Sri) values less than 0.704, and (3) crustal melting to give high Sri values greater than 0.704. Geochemical evidence was used to determine the extent of mixing between mafic and felsic magma that produced rocks of intermediate SiO2 composition. These differentiation cycles formed a west to east chronologic sequence and yielded granitoids of gabbro, tonalite, and granodiorite composition. Using principal component analysis on the northern PRB granitoids, the four factors affecting geochemical composition were categorized as differentiation, crustal contamination, depth of magma source, and conditions that yield a range from calcic to more alkaline granitoids. A similar major and trace element analysis is being done for a classic result of subduction in the Peruvian Coastal Batholith. The Peruvian samples recently collected include granitoids of the upper Cretaceous Coastal Batholith, as well as the associated volcanics of Cretaceous and Jurassic age. The Coastal Batholith samples include a range of granitoids from the early gabbros and from the four batholithic super-units (from west to east: Linga, Pampahuasi, Tiabaya, and Incahuasi) containing a combination of diorite, tonalite, monzonite, and granodiorite. In addition, samples were taken from the adjacent Precambrian basement and Paleozoic San Nicolas batholith in order to estimate the local geochemistry for continental crust contamination and to compare with published crustal averages. For this part of the Coastal Batholith, gabbroic plutons that formed during extension have little contamination from continental crust; the time-separated super-units form distinct assemblages; some of the super-units went through several differentiation cycles; parts of the Linga super-unit have low Sri ratios below 0.704; and magma mixing played an important role. The Coastal Batholith of western Peru (similar to the eastern PRB) has an intermediate calc-alkaline composition, in comparison to batholiths in Chile (similar to the western PRB) that are more calcic and those in eastern Peru (similar to the Sierra Nevadas) that are more alkaline.

Interaction Effects of Temperature and Ozone on Lung Function and Markers of Systemic Inflammation, Coagulation, and Fibrinolysis: A Crossover Study of Healthy Young Volunteers

PubMed Central

Kahle, Juliette J.; Neas, Lucas M.; Devlin, Robert B.; Case, Martin W.; Schmitt, Michael T.; Madden, Michael C.

2014-01-01

Background: Trends in climate suggest that extreme weather events such as heat waves will become more common. High levels of the gaseous pollutant ozone are associated with elevated temperatures. Ozone has been associated with respiratory diseases as well as cardiovascular morbidity and mortality and can reduce lung function and alter systemic markers of fibrinolysis. The interaction between ozone and temperature is unclear. Methods: Sixteen healthy volunteers were exposed in a randomized crossover study to 0.3 ppm ozone and clean air for 2 hr at moderate (22°C) temperature and again at an elevated temperature (32.5°C). In each case lung function was performed and blood taken before and immediately after exposure and the next morning. Results: Ozone exposure at 22°C resulted in a decrease in markers of fibrinolysis the next day. There was a 51.8% net decrease in PAI-1 (plasminogen activator inhibitor-1), a 12.1% net decrease in plasminogen, and a 17.8% net increase in D-dimer. These significantly differed from the response at 32.5°C, where there was a 44.9% (p = 0.002) and a 27.9% (p = 0.001) increase in PAI-1 and plasminogen, respectively, and a 12.5% (p = 0.042) decrease in D-dimer. In contrast, decrements in lung function following ozone exposure were comparable at both moderate and elevated temperatures (forced expiratory volume in 1 sec, –12.4% vs. –7.5%, p > 0.05). No changes in systemic markers of inflammation were observed for either temperature. Conclusion: Ozone-induced systemic but not respiratory effects varied according to temperature. Our study suggests that at moderate temperature ozone may activate the fibrinolytic pathway, while at elevated temperature ozone may impair it. These findings provide a biological basis for the interaction between temperature and ozone on mortality observed in some epidemiologic studies. Citation: Kahle JJ, Neas LM, Devlin RB, Case MW, Schmitt MT, Madden MC, Diaz-Sanchez D. 2015. Interaction effects of temperature and ozone on lung function and markers of systemic inflammation, coagulation, and fibrinolysis: a crossover study of healthy young volunteers. Environ Health Perspect 123:310–316; http://dx.doi.org/10.1289/ehp.1307986 PMID:25514459

Impact of climate variability on tropospheric ozone.

PubMed

Grewe, Volker

2007-03-01

A simulation with the climate-chemistry model (CCM) E39/C is presented, which covers both the troposphere and stratosphere dynamics and chemistry during the period 1960 to 1999. Although the CCM, by its nature, is not exactly representing observed day-by-day meteorology, there is an overall model's tendency to correctly reproduce the variability pattern due to an inclusion of realistic external forcings, like observed sea surface temperatures (e.g. El Niño), major volcanic eruption, solar cycle, concentrations of greenhouse gases, and Quasi-Biennial Oscillation. Additionally, climate-chemistry interactions are included, like the impact of ozone, methane, and other species on radiation and dynamics, and the impact of dynamics on emissions (lightning). However, a number of important feedbacks are not yet included (e.g. feedbacks related to biogenic emissions and emissions due to biomass burning). The results show a good representation of the evolution of the stratospheric ozone layer, including the ozone hole, which plays an important role for the simulation of natural variability of tropospheric ozone. Anthropogenic NO(x) emissions are included with a step-wise linear trend for each sector, but no interannual variability is included. The application of a number of diagnostics (e.g. marked ozone tracers) allows the separation of the impact of various processes/emissions on tropospheric ozone and shows that the simulated Northern Hemisphere tropospheric ozone budget is not only dominated by nitrogen oxide emissions and other ozone pre-cursors, but also by changes of the stratospheric ozone budget and its flux into the troposphere, which tends to reduce the simulated positive trend in tropospheric ozone due to emissions from industry and traffic during the late 80s and early 90s. For tropical regions the variability in ozone is dominated by variability in lightning (related to ENSO) and stratosphere-troposphere exchange (related to Northern Hemisphere Stratospheric dynamics and solar activity). Since tropospheric background chemistry is regarded only, the results are quantitatively limited with respect to derived trends. However, the main results are regarded to be robust. Although the horizontal resolution is rather coarse in comparison to regional models, such kind of simulations provide useful and necessary information on the impact of large-scale processes and inter-annual/decadal variations on regional air quality.

A Time-Stratified Case-Crossover Study of Ambient Ozone Exposure and Emergency Department Visits for Specific Respiratory Diagnoses in California (2005–2008)

PubMed Central

Malig, Brian J.; Pearson, Dharshani L.; Chang, Yun Brenda; Broadwin, Rachel; Basu, Rupa; Green, Rochelle S.; Ostro, Bart

2015-01-01

Background: Studies have explored ozone’s connection to asthma and total respiratory emergency department visits (EDVs) but have neglected other specific respiratory diagnoses despite hypotheses relating ozone to respiratory infections and allergic responses. Objective: We examined relationships between ozone and EDVs for respiratory visits, including specifically acute respiratory infections (ARI), asthma, pneumonia, chronic obstructive pulmonary disease (COPD), and upper respiratory tract inflammation (URTI). Methods: We conducted a multi-site time-stratified case-crossover study of ozone exposures for approximately 3.7 million respiratory EDVs from 2005 through 2008 among California residents living within 20 km of an ozone monitor. Conditional logistic regression was used to estimate associations by climate zone. Random effects meta-analysis was then applied to estimate pooled excess risks (ER). Effect modification by season, distance from the monitor and individual demographic characteristics (i.e., age, race/ethnicity, sex, and payment method), and confounding by other gaseous air pollutants were also investigated. Meta-regression was utilized to explore how climate zone–level meteorological, demographic, and regional differences influenced estimates. Results: We observed ozone-associated increases in all respiratory, asthma, and ARI visits, which were slightly larger in the warm season [asthma ER per 10-ppb increase in mean of same and previous 3 days ozone exposure (lag03) = 2.7%, 95% CI: 1.5, 3.9; ARI ERlag03 = 1.4%, 95% CI: 0.8, 1.9]. EDVs for pneumonia, COPD, and URTI were also significantly associated with ozone exposure over the whole year, but typically more consistently so during the warm season. Conclusions: Short-term ozone exposures among California residents living near an ozone monitor were positively associated with EDVs for asthma, ARI, pneumonia, COPD, and URTI from 2005 through 2008. Those associations were typically larger and more consistent during the warm season. Our findings suggest that these outcomes should be considered when evaluating the potential health benefits of reducing ozone concentrations. Citation: Malig BJ, Pearson DL, Chang YB, Broadwin R, Basu R, Green RS, Ostro B. 2016. A time-stratified case-crossover study of ambient ozone exposure and emergency department visits for specific respiratory diagnoses in California (2005–2008). Environ Health Perspect 124:745–753; http://dx.doi.org/10.1289/ehp.1409495 PMID:26647366

Ozone perturbations in the Arctic summer lower stratosphere as a reflection of NOX chemistry and planetary scale wave activity

NASA Astrophysics Data System (ADS)

Akiyoshi, H.; Sugita, T.; Kanzawa, H.; Kawamoto, N.

2004-02-01

Ozone concentration perturbations in the high-latitude lower stratosphere in the Northern Hemisphere were observed by Improved Limb Atmospheric Spectrometer (ILAS) after the polar vortex breakdown at the beginning of May 1997 and until the end of June of that same year. Simulations and a passive tracer experiment using the Center for Climate System Research/National Institute for Environmental Studies (CCSR/NIES) nudging chemical transport model (CTM) show that the low-ozone perturbations observed in May were caused by the Arctic polar vortex debris, while those after the end of May resulted from a dynamical elongation due to zonal wave number 2 planetary waves of the low-ozone region in the summer polar stratosphere, which had been developed by the catalytic ozone destruction cycle of NOX. These low-O3 air masses of different origin were advected or elongated from the polar region to the ILAS measurement points. An episodic event of a dynamical O3 perturbation in June 1997 on a chemically induced meridional O3 gradient is described. These results show that a timing of the polar vortex breakdown and activity of planetary waves after the breakdown may affect the O3 background gradient in the summer lower stratosphere at middle and high latitudes.

Stratospheric ozone levels and their role for the dynamic response to volcanic eruptions

NASA Astrophysics Data System (ADS)

Muthers, Stefan; Anet, Julien G.; Raible, Christoph C.; Brönnimann, Stefan; Arfeuille, Florian; Peter, Tom; Rozanov, Eugene; Shapiro, Alexander; Beer, Juerg; Steinhilber, Friedhelm; Brugnara, Yuri; Schmutz, Werner

2013-04-01

The role of different background ozone climatologies for the dynamic response to tropical volcanic eruptions is analyzed using an ensemble of simulation with the atmospheric-chemistry-ocean model SOCOL/MPIOM. In this sensitivity study a single tropical eruption of Tambora-size is applied to an ensemble with either pre-industrial ozone concentrations or present day concentrations respectively. The analysis focuses on the characteristic of the Northern Europe winter warming pattern following the eruption, that has been identified after several eruptions in observations and in proxy data. The sensitivity study reveals a higher probability for a large and significant winter warming pattern with pre-industrial ozone levels, when the dynamic response of the chemistry to the eruption is disabled in the model. The positive temperature anomaly is driven by a positive NAO-like pressure pattern that lead to the advection of warm Atlantic air towards Northern Europe. With present day concentrations winter warmings are also found in some ensemble members, but overall the probability is strongly reduced. It is shown, that with pre-industial day ozone concentrations the coupling between positive anomalies of the polar vortex and the zonal wind in the troposphere is more effective, which could explain the higher likelihood of positive NAO-like pressure patterns and positive temperature anomalies in Northern Europe.

The effect of oxidant on resputtering of Bi from Bi-Sr-Ca-Cu-O films

NASA Astrophysics Data System (ADS)

Grace, J. M.; McDonald, D. B.; Reiten, M. T.; Olson, J.; Kampwirth, R. T.; Gray, K. E.

1991-09-01

The type and partial pressure of oxidant mixed with argon can affect the selective resputtering of Bi in composite-target, magnetron-sputtered Bi-Sr-Ca-Cu-O films. Comparative studies using oxygen and ozone show that ozone is a more potent oxidant, as well as a more potent source of resputterers, than is oxygen. Severe resputtering from ozone is significantly reduced by a -40 V potential on the sample block. We suggest that oxygen causes resputtering by forming O2(+)p , which interacts with the target to produce energetic O(-). In contrast, ozone may form lower-energy O(-) by electron impact in the dark space. Negative oxygen ions from the target itself may be responsible for a background resputtering effect. Our results and those found for Y-Ba-Cu-O by others are comparable. Bi in Bi-Sr-Ca-Cu-O behaves as Ba in Y-Ba-Cu-O, with regard to selective resputtering; furthermore, the response of Sr, Ca, and Cu to oxygen in sputtered Bi-Sr-Ca-Cu-O is similar to what is observed for Cu in Y-Ba-Cu-O.

Emissions from the Bena Landfill

NASA Astrophysics Data System (ADS)

Schafer, C.; Blake, D. R.; Hughes, S.

2016-12-01

In 2013, Americans generated 254 million tons of municipal solid waste (MSW). The gas generated from the decomposition of MSW is composed of approximately 50% methane, 50% carbon dioxide, and a small proportion of non-methane organic compounds (NMOCs). NMOCs constitute less than 1% of landfill emissions, but they can have a disproportionate environmental impact as they are highly reactive ozone precursors. During the 2016 Student Airborne Research Program (SARP), whole air samples were collected at the Bena landfill outside of Bakersfield, CA and throughout Bakersfield and analyzed using gas chromatography in order to quantify NMOC emissions. This area was determined to have elevated concentrations of benzene, trichloroethylene, and tetrachloroethylene, all of which are categorized by the EPA as hazardous to human health. Benzene was found to have a concentration of 145 ± 4 pptv, four times higher than the background levels in Bakersfield (36 ± 1 pptv). Trichloroethylene and tetrachloroethylene had concentrations of 18 ± 1 pptv and 31 ± 1 pptv which were 18 and 10 times greater than background concentrations, respectively. In addition, hydroxyl radical reactivity (ROH) was calculated to determine the potential for tropospheric ozone formation. The total ROH of the landfill was 7.5 ± 0.2 s-1 compared to total background ROH of 1.0 ± 0.1 s-1 . NMOCs only made up 0.6% of total emissions, but accounted for 67% of total ROH.These results can help to shape future landfill emission policies by highlighting the importance of NMOCs in addition to methane. More research is needed to investigate the ozone forming potential of these compounds at landfills across the country.

pH-Sensitive PEGylated liposomes functionalized with a fibronectin-mimetic peptide show enhanced intracellular delivery to colon cancer cell.

PubMed

Garg, Ashish; Kokkoli, Efrosini

2011-08-01

pH-sensitive liposomes undergo rapid destabilization under mildly acidic conditions such as those found in endocytotic vesicles. Though this makes them promising drug carriers, their application is limited due to their rapid clearance from circulation by the reticulo-endothelial system. Researchers have therefore used pH-sensitive liposomes that are sterically stabilized by polyethylene glycol (PEG) molecules (stealth liposomes) on the liposome surface. The goal of this study is to bring bio-functionality to pH-sensitive PEGylated liposomes in order to facilitate their potential use as a targeted drug delivery agent. To improve the selectivity of these nanoparticles, we included a targeting moiety, PR_b which specifically recognizes and binds to integrin α(5)β(1) expressing cells. PR_b (KSSPHSRN(SG)(5)RGDSP) is a novel fibronectin-mimetic peptide sequence that mimics the cell adhesion domain of fibronectin. Integrin α(5)β(1) is expressed on several types of cancer cells, including colon cancer, and plays an important role in tumor growth and metastasis. We have thoroughly studied the release of calcein from pH-sensitive PEGylated liposomes by varying the lipid composition of the liposomes in the absence and presence of the targeting peptide, PR_b, and accounting for the first time for the effect of both pH and time (photo-bleaching effect) on the fluorescence signal of calcein. We have demonstrated that we can design PR_b-targeted pH-sensitive PEGylated liposomes, which can undergo destabilization under mildly acidic conditions and have shown that incorporating the PR_b peptide does not significantly affect the pH-sensitivity of the liposomes. PR_b-targeted pH-sensitive PEGylated liposomes bind to CT26.WT colon carcinoma cells that express integrin α(5)β(1), undergo cellular internalization, and release their load intracellularly in a short period of time as compared to other formulations. Our studies demonstrate that PR_b-functionalized pH-sensitive targeted delivery systems have the potential to deliver a payload directly to cancer cells in an efficient and specific manner.

Environmental implications of United States coal exports: a comparative life cycle assessment of future power system scenarios.

PubMed

Bohnengel, Barrett; Patiño-Echeverri, Dalia; Bergerson, Joule

2014-08-19

Stricter emissions requirements on coal-fired power plants together with low natural gas prices have contributed to a recent decline in the use of coal for electricity generation in the United States. Faced with a shrinking domestic market, many coal companies are taking advantage of a growing coal export market. As a result, U.S. coal exports hit an all-time high in 2012, fueled largely by demand in Asia. This paper presents a comparative life cycle assessment of two scenarios: a baseline scenario in which coal continues to be burned domestically for power generation, and an export scenario in which coal is exported to Asia. For the coal export scenario we focus on the Morrow Pacific export project being planned in Oregon by Ambre Energy that would ship 8.8 million tons of Powder River Basin (PRB) coal annually to Asian markets via rail, river barge, and ocean vessel. Air emissions (SOx, NOx, PM10 and CO2e) results assuming that the exported coal is burned for electricity generation in South Korea are compared to those of a business as usual case in which Oregon and Washington's coal plants, Boardman and Centralia, are retrofitted to comply with EPA emissions standards and continue their coal consumption. Findings show that although the environmental impacts of shipping PRB coal to Asia are significant, the combination of superior energy efficiency among newer South Korean coal-fired power plants and lower emissions from U.S. replacement of coal with natural gas could lead to a greenhouse gas reduction of 21% in the case that imported PRB coal replaces other coal sources in this Asian country. If instead PRB coal were to replace natural gas or nuclear generation in South Korea, greenhouse gas emissions per unit of electricity generated would increase. Results are similar for other air emissions such as SOx, NOx and PM. This study provides a framework for comparing energy export scenarios and highlights the importance of complete life cycle assessment in determining net emissions effects resulting from energy export projects and related policy decisions.

Chemical contaminants, health indicators, and reproductive biomarker responses in fish from rivers in the Southeastern United States

USGS Publications Warehouse

Hinck, J.E.; Blazer, V.S.; Denslow, N.D.; Echols, K.R.; Gale, R.W.; Wieser, C.; May, T.W.; Ellersieck, M.; Coyle, J.J.; Tillitt, D.E.

2008-01-01

Largemouth bass (Micropterus salmoides) and common carp (Cyprinus carpio) were collected from 13 sites located in the Mobile (MRB), Apalachicola-Flint-Chattahoochee (ARB), Savannah (SRB), and Pee Dee (PRB) River Basins to document spatial trends in accumulative chemical contaminants, health indicators, and reproductive biomarkers. Organochlorine residues, 2,3,7,8-tetrachlorodibenzo-p-dioxin-like activity (TCDD-EQ), and elemental contaminants were measured in composite samples of whole fish, grouped by species and gender, from each site. Mercury (Hg) and polychlorinated biphenyls (PCBs) were the primary contaminants of concern. Concentrations of Hg in bass samples from all basins exceeded toxicity thresholds for piscivorous mammals (> 0.1????g/g ww), juvenile and adult fish (> 0.2????g/g ww), and piscivorous birds (> 0.3????g/g ww). Total PCB concentrations in samples from the MRB, ARB, and PRB were > 480??ng/g ww and may be a risk to piscivorous wildlife. Selenium concentrations also exceeded toxicity thresholds (> 0.75????g/g ww) in MRB and ARB fish. Concentrations of other formerly used (total chlordanes, dieldrin, endrin, aldrin, mirex, and hexachlorobenzene) and currently used (pentachlorobenzene, pentachloroanisole, dacthal, endosulfan, ??-hexachlorocyclohexane, and methoxychlor) organochlorine residues were generally low or did not exceed toxicity thresholds for fish and piscivorous wildlife. TCDD-EQs exceeded wildlife dietary guidelines (> 5??pg/g ww) in MRB and PRB fish. Hepatic ethoxyresorufin O-deethylase (EROD) activity was generally greatest in MRB bass and carp. Altered fish health indicators and reproductive biomarker were noted in individual fish, but mean responses were similar among basins. The field necropsy and histopathological examination determined that MRB fish were generally in poorer health than those from the other basins, primarily due to parasitic infestations. Tumors were found in few fish (n = 5; 0.01%); ovarian tumors of smooth muscle origin were found in two ARB carp from the same site. Intersex gonads were identified in 47 male bass (42%) representing 12 sites and may indicate exposure to potential endocrine disrupting compounds. Comparatively high vitellogenin concentrations (> 0.35??mg/mL) in male fish from the MRB, SRB, and PRB indicate exposure to estrogenic or anti-androgenic chemicals.

Changes in US background ozone due to global anthropogenic emissions from 1970 to 2020

NASA Astrophysics Data System (ADS)

Nopmongcol, Uarporn; Jung, Jaegun; Kumar, Naresh; Yarwood, Greg

2016-09-01

Estimates of North American and US Background (NAB and USB) ozone (O3) are critical in setting and implementing the US National Ambient Air Quality Standards (NAAQS) and therefore influence population exposure to O3 across the US. NAB is defined as the O3 concentration in the absence of anthropogenic O3 precursor emissions from North America whereas USB excludes anthropogenic emissions inside the US alone. NAB and USB vary geographically and with time of year. Analyses of O3 trends at rural locations near the west coast suggest that background O3 is rising in response to increasing non-US emissions. As the O3 NAAQS is lowered, rising background O3 would make attaining the NAAQS more difficult. Most studies of changing US background O3 have inferred trends from observations whereas air quality management decisions tend to rely on models. Thus, it is important that the models used to develop O3 management strategies are able to represent the changes in background O3 in order to increase confidence that air quality management strategies will succeed. We focus on how changing global emissions influence USB rather than the effects of inter-annual meteorological variation or long-term climate change. We use a regional model (CAMx) nested within a global model (GEOS-Chem) to refine our grid resolution over high terrain in the western US and near US borders where USB tends to be higher. We determine USB from CAMx simulations that exclude US anthropogenic emissions. Over five decades, from 1970 to 2020, estimated USB for the annual fourth highest maximum daily 8-h average O3 (H4MDA8) in the western US increased from mostly in the range of 40-55 ppb to 45-60 ppb, but remained below 45 ppb in the eastern US. USB increases in the southwestern US are consistent with rising emissions in Asia and Mexico. USB decreases in the northeast US after 1990 follow declining Canadian emissions. Our results show that the USB increases both for the top 30 MDA8 days and the H4MDA8 (the former at a faster rate in most areas). Our USB increases in the western US are lower by about a factor of four than trends inferred from analyses of rural ozone near the west coast which is consistent with meteorology also influencing the observed ozone trends. Comparing H4MDA8 NAB and USB for 2020 shows that contributions from neighbouring countries can exceed 4 ppb near the Canadian border and 2 ppb near the Mexican border.

Monitoring Intracellular Redox Changes in Ozone-exposed airway epithelial cells

EPA Science Inventory

Background: The toxicity of many compounds involves oxidative injury to cells. Direct assessment of mechanistic events involved in xenobiotic-induced oxidative stress is not easily achievable. Development of genetically-encoded probes designed for monitoring intracellular redox s...

Estimating vertical fluxes of ozone within the atmospheric boundary layer

NASA Astrophysics Data System (ADS)

Belan, Boris D.; Antokhin, Pavel N.; Antokhina, Olga Yu.; Arshinov, Mikhail Yu.; Belan, Sergey B.; Davydov, Denis K.; Krasnov, Oleg A.; Penenko, Alexey V.; Savkin, Denis E.; Sklyadneva, Tatayna K.; Tolmahev, Gennadii N.

2017-04-01

Investigation of the vertical distribution of ozone within the atmospheric boundary layer (ABL) was carried out by use of AN-2 light aircraft as a research platform. Vertical fluxes of ozone and their direction from the ground to the free-tropospheric level were calculated based on the in situ measurement data. Research flights have been performed over the greenhouse gas monitoring station located in a background area (56.1-56.4 N, 84.2-84.8 E) in the vicinity of abandoned village of Berezorechka (West Siberia). The schedule of diurnal flights was as follows: the first one just after the sunrise; the second one at noon; the third one 2-3 hours after noon, when a well-developed turbulence is observed; and the last one just before the sunset. A total of 10 diurnal cycles of measurements were undertaken. Analysis of the obtained data showed that the rate of ozone influx from upper layers of the atmosphere is 3-10 times less than the ozone production rate in the ABL. Average rate of ozone influx from the free troposphere was about 1 μg m-3 h-1, but ozone production rate in the ABL was about 5 μg m-3 h-1, so the major part of ozone is formed by photochemical reactions that occur within the ABL and only 20 % of its content is determined by the influx from the free troposphere. The vertical profiles of the ozone fluxes have shown that their maximum values are observed at heights from 200 to 600 m AGL. The height of the maximum depends on the season: in winter it is lower than 200-300 m, and in summer the maximum is observed at 500-600 m. The value of the ozone flux maximum also depends on the season and varies from 1 μg m-2 s-1in winter to 4.2 μg m-2 s-1 in spring. This work was supported by the Russian Foundation for Basic Research (grant No 17-05-00374).

75 FR 52801 - Membership of the Performance Review Board (PRB)

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-27

... for Administration and Director of Human Resources (202) 395-7360. Lorraine Green, Deputy Assistant U.S. Trade Representative for Administration and Director of Human Resources. [FR Doc. 2010-21371...

78 FR 57837 - Senior Executive Service Performance Review Board

Federal Register 2010, 2011, 2012, 2013, 2014

2013-09-20

... Chair of the PRB; Fran Leonard, Chief of Staff, Federal Mediation and Conciliation Service; Nadine... Counsel, Institute of Museum and Library Services. This notice is published in the Federal Register...

Impacts of different characterizations of large-scale background on simulated regional-scale ozone over the continental United States

NASA Astrophysics Data System (ADS)

Hogrefe, Christian; Liu, Peng; Pouliot, George; Mathur, Rohit; Roselle, Shawn; Flemming, Johannes; Lin, Meiyun; Park, Rokjin J.

2018-03-01

This study analyzes simulated regional-scale ozone burdens both near the surface and aloft, estimates process contributions to these burdens, and calculates the sensitivity of the simulated regional-scale ozone burden to several key model inputs with a particular emphasis on boundary conditions derived from hemispheric or global-scale models. The Community Multiscale Air Quality (CMAQ) model simulations supporting this analysis were performed over the continental US for the year 2010 within the context of the Air Quality Model Evaluation International Initiative (AQMEII) and Task Force on Hemispheric Transport of Air Pollution (TF-HTAP) activities. CMAQ process analysis (PA) results highlight the dominant role of horizontal and vertical advection on the ozone burden in the mid-to-upper troposphere and lower stratosphere. Vertical mixing, including mixing by convective clouds, couples fluctuations in free-tropospheric ozone to ozone in lower layers. Hypothetical bounding scenarios were performed to quantify the effects of emissions, boundary conditions, and ozone dry deposition on the simulated ozone burden. Analysis of these simulations confirms that the characterization of ozone outside the regional-scale modeling domain can have a profound impact on simulated regional-scale ozone. This was further investigated by using data from four hemispheric or global modeling systems (Chemistry - Integrated Forecasting Model (C-IFS), CMAQ extended for hemispheric applications (H-CMAQ), the Goddard Earth Observing System model coupled to chemistry (GEOS-Chem), and AM3) to derive alternate boundary conditions for the regional-scale CMAQ simulations. The regional-scale CMAQ simulations using these four different boundary conditions showed that the largest ozone abundance in the upper layers was simulated when using boundary conditions from GEOS-Chem, followed by the simulations using C-IFS, AM3, and H-CMAQ boundary conditions, consistent with the analysis of the ozone fields from the global models along the CMAQ boundaries. Using boundary conditions from AM3 yielded higher springtime ozone columns burdens in the middle and lower troposphere compared to boundary conditions from the other models. For surface ozone, the differences between the AM3-driven CMAQ simulations and the CMAQ simulations driven by other large-scale models are especially pronounced during spring and winter where they can reach more than 10 ppb for seasonal mean ozone mixing ratios and as much as 15 ppb for domain-averaged daily maximum 8 h average ozone on individual days. In contrast, the differences between the C-IFS-, GEOS-Chem-, and H-CMAQ-driven regional-scale CMAQ simulations are typically smaller. Comparing simulated surface ozone mixing ratios to observations and computing seasonal and regional model performance statistics revealed that boundary conditions can have a substantial impact on model performance. Further analysis showed that boundary conditions can affect model performance across the entire range of the observed distribution, although the impacts tend to be lower during summer and for the very highest observed percentiles. The results are discussed in the context of future model development and analysis opportunities.

Variability and changes in tropospheric ozone over the western United States (1980-2010): Exploring the roles of stratosphere-to-troposphere transport and El Niño-Southern Oscillation

NASA Astrophysics Data System (ADS)

Lin, M.; Fiore, A. M.; Horowitz, L. W.; Naik, V.; Oltmans, S. J.; Levy, H.; Cooper, O. R.; Johnson, B. J.

2011-12-01

Understanding the drivers of inter-annual variability and long-term changes of tropospheric ozone is crucial for designing appropriate control policies. Advancing this knowledge will also enable process-oriented assessments of chemistry-climate models, which are needed to build confidence in their utility for projecting tropospheric ozone under future climate scenarios. We examine here the response of North American background ozone over the past 30 years (1980-2010) to changes in atmospheric circulation and chemistry, both in the stratosphere and in the troposphere, through an integrated analysis of observational records from satellite, ozonesonde and ground-based networks with the GFDL AM3 global chemistry-climate model (nudged to reanalysis winds to allow for exact space-time comparisons with the observational datasets). Comparing the model simulation with ~30 years of ozone measurements at Mauna Loa ground station (~3397 m a.s.l.) and Hilo sonde (550-450 hPa) in Hawaii, we find that mid-tropospheric ozone in the eastern Pacific extratropics is enhanced by ~5-10 ppbv (~10-20% deviations from the climatological mean) during strong El Niño events (i.e. 1982-1983, 1997-1998, 2009-2010), presumably reflecting stronger transport from the stratosphere and Asia due to the eastward extension of the Pacific storm tracks and amplified subtropical jet. The La Niña condition typically manifests in the opposite sign, with ozone decreasing north of Hawaii. Over the western U.S., however, both cyclonic and anticyclonic circulation following strong El Niño and La Niña winters, respectively, may enhance deep stratosphere-to-troposphere transport in spring. Both ozonesonde and model results sampled at Trinidad Head, California, indicate ~25% positive deviations in UT/LS ozone during the El Niño winters of 1997-1998 and 2009-2010. We find that this ENSO-related UT/LS ozone variability is also captured in satellite-derived total column ozone from TOMS and AIRS over the Northwest U.S. in May. In contrast, enhanced lower tropospheric ozone over the western U.S. during strong La Niña years (e.g. 1999) mostly reflect changes in atmospheric dynamics rather than lower stratospheric ozone. The model indicates a 0.2 ppb/yr increase in mid-tropospheric ozone over the past 25 years. We are implementing a stratospheric ozone tracer in the model to quantify the springtime stratospheric enhancement to the high tail of daily maximum 8-hour surface ozone frequency during both phases of ENSO. We expect that the associated variability should provide insights regarding potential responses to climate shifts as well as inform air quality planning and control strategies to attain the national standard.

Contributions of regional and intercontinental transport to surface ozone in the Tokyo area

NASA Astrophysics Data System (ADS)

Yoshitomi, M.; Wild, O.; Akimoto, H.

2011-08-01

Japan lies downwind of the Asian continent and for much of the year air quality is directly influenced by emissions of ozone precursors over these heavily-populated and rapidly-industrializing regions. This study examines the extent to which oxidant transport from regional and distant anthropogenic sources influences air quality in Japan in springtime, when these contributions are largest. We find that European and North American contributions to surface ozone over Japan in spring are persistent, averaging 3.5±1.1 ppb and 2.8±0.5 ppb respectively, and are greatest in cold continental outflow conditions following the passage of cold fronts. Contributions from China are larger, 4.0±2.8 ppb, and more variable, as expected for a closer source region, and are generally highest near cold fronts preceding the influence of more distant sources. The stratosphere provides a varying but ever-present background of ozone of about 11.2±2.5 ppb during spring. Local sources over Japan and Korea have a relatively small impact on mean ozone, 2.4±7.6 ppb, but this masks a strong diurnal signal, and local sources clearly dominate during episodes of high daytime ozone. By examining the meteorological mechanisms that favour transport from different source regions, we demonstrate that while maximum foreign influence generally does not occur at the same time as the greatest buildup of oxidants from local sources, it retains a significant influence under these conditions. It is thus clear that while meteorological boundaries provide some protection from foreign influence during oxidant outbreaks in Tokyo, these distant sources still make a substantial contribution to exceedance of the Japanese ozone air quality standard in springtime.

Contributions of regional and intercontinental transport to surface ozone in Tokyo

NASA Astrophysics Data System (ADS)

Yoshitomi, M.; Wild, O.; Akimoto, H.

2011-04-01

Japan lies downwind of the Asian continent and for much of the year air quality is directly influenced by emissions of ozone precursors over these heavily-populated and rapidly-industrializing regions. This study examines the extent to which oxidant transport from regional and distant anthropogenic sources influences air quality in Japan in springtime, when these contributions are largest. We find that European and North American contributions to surface ozone over Japan in spring are persistent, averaging 3.5±1.1 ppb and 2.8±0.5 ppb respectively, and are greatest in cold continental outflow conditions following the passage of cold fronts. Contributions from China are larger, 4.0±2.8 ppb, and more variable, as expected for a closer source region, and are generally highest near cold fronts preceding the influence of more distant sources. The stratosphere provides a varying but ever-present background of ozone of about 11.2±2.5 ppb during spring. Local sources over Japan and Korea have a relatively small impact on mean ozone, 2.4±7.6 ppb, but this masks a strong diurnal signal, and local sources clearly dominate during episodes of high daytime ozone. By examining the meteorological mechanisms that favour transport from different source regions, we demonstrate that while maximum foreign influence generally does not occur at the same time as the greatest buildup of oxidants from local sources, it retains a significant influence under these conditions. It is thus clear that while meteorological boundaries provide some protection from foreign influence during oxidant outbreaks in Tokyo, these distant sources still make a substantial contribution to exceedance of the Japanese ozone air quality standard in springtime.

Land use regression modeling of ultrafine particles, ozone, nitrogen oxides and markers of particulate matter pollution in Augsburg, Germany.

PubMed

Wolf, Kathrin; Cyrys, Josef; Harciníková, Tatiana; Gu, Jianwei; Kusch, Thomas; Hampel, Regina; Schneider, Alexandra; Peters, Annette

2017-02-01

Important health relevance has been suggested for ultrafine particles (UFP) and ozone, but studies on long-term effects are scarce, mainly due to the lack of appropriate spatial exposure models. We designed a measurement campaign to develop land use regression (LUR) models to predict the spatial variability focusing on particle number concentration (PNC) as indicator for UFP, ozone and several other air pollutants in the Augsburg region, Southern Germany. Three bi-weekly measurements of PNC, ozone, particulate matter (PM 10 , PM 2.5 ), soot (PM 2.5 abs) and nitrogen oxides (NO x , NO 2 ) were performed at 20 sites in 2014/15. Annual average concentration were calculated and temporally adjusted by measurements from a continuous background station. As geographic predictors we offered several traffic and land use variables, altitude, population and building density. Models were validated using leave-one-out cross-validation. Adjusted model explained variance (R 2 ) was high for PNC and ozone (0.89 and 0.88). Cross-validation adjusted R 2 was slightly lower (0.82 and 0.81) but still indicated a very good fit. LUR models for other pollutants performed well with adjusted R 2 between 0.68 (PM coarse ) and 0.94 (NO 2 ). Contrary to previous studies, ozone showed a moderate correlation with NO 2 (Pearson's r=-0.26). PNC was moderately correlated with ozone and PM 2.5 , but highly correlated with NO x (r=0.91). For PNC and NO x , LUR models comprised similar predictors and future epidemiological analyses evaluating health effects need to consider these similarities. Copyright © 2016 Elsevier B.V. All rights reserved.

A Decadal (2004-2014) Analysis of Global-to-Regional Tropospheric Ozone Column Trends Using GFDL-AM3 Model Simulations and OMI Observations

NASA Astrophysics Data System (ADS)

Huang, G.; Liu, X.; Lin, M.; Ziemke, J. R.; Chance, K.; Zoogman, P.; Sun, K.

2017-12-01

Tropospheric ozone is a greenhouse gas, biological irritant, and significant source of highly reactive hydroxyl radicals, which remove many hazardous trace gases from the atmosphere. The decadal trend of tropospheric ozone columns (TOCs) can be influenced by many factors including anthropogenic and natural emissions of ozone precursors, large-scale atmospheric circulation patterns, and stratosphere-to-troposphere exchange. Since 2000, anthropogenic emissions of NOx have tended to shift from North America and Europe to Asia. This rapid shift has been implicated in raising background tropospheric ozone burden. However, large meteorologically-driven ozone variability complicates the unambiguous attribution of TOC trends calculated over short periods. In this study, we examine global-to-regional TOC trends during 2004-2014 using two independent satellite retrievals from OMI SAO (Smithsonian Astrophysical Observatory) and OMI/MLS, and interpret the results with a suite of GFDL-AM3 chemistry-climate model hindcasts designed to isolate the response of ozone to anthropogenic emissions, wildfires, and meteorology. Generally, OMI SAO, OMI/MLS and GFDL-AM3 BASE simulations agree on regional hot spots of TOC trends. On the regional scale, we find strong positive TOC trends during 2004-2014 in Mid-East (0.3-0.6 DU yr-1), South Asia (0.3-0.5 DU yr-1), Southeast Asia, East Asia ( 0.1-0.6 DU yr-1) and Central Africa ( 0.6 DU yr-1). Our initial analysis indicates that meteorological variability and anthropogenic emission trends play equally important roles in the positive TOC trends in East Asia and on a global scale during 2004-2014. We are working to investigate the potential influences from lightening NOx emissions, forest fires, and the stratosphere-to-troposphere exchange.

76 FR 64428 - Senior Executive Service; Combined Performance Review Board (PRB)

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-18

... Greiner, Chief Financial Officer, United States Mint. John J. Manfreda, Administrator, TTB. Diane K. Wade... of Engraving and Printing (BEP), the Financial Management Service (FMS), the United [[Page 64429

Slider--maximum use of probability information for alignment of short sequence reads and SNP detection.

PubMed

Malhis, Nawar; Butterfield, Yaron S N; Ester, Martin; Jones, Steven J M

2009-01-01

A plethora of alignment tools have been created that are designed to best fit different types of alignment conditions. While some of these are made for aligning Illumina Sequence Analyzer reads, none of these are fully utilizing its probability (prb) output. In this article, we will introduce a new alignment approach (Slider) that reduces the alignment problem space by utilizing each read base's probabilities given in the prb files. Compared with other aligners, Slider has higher alignment accuracy and efficiency. In addition, given that Slider matches bases with probabilities other than the most probable, it significantly reduces the percentage of base mismatches. The result is that its SNP predictions are more accurate than other SNP prediction approaches used today that start from the most probable sequence, including those using base quality.

Linear Dichroism in Angle-Resolved Core-Level Photoemission Spectra Reflecting 4f Ground-State Symmetry of Strongly Correlated Cubic Pr Compounds

NASA Astrophysics Data System (ADS)

Hamamoto, Satoru; Fujioka, Shuhei; Kanai, Yuina; Yamagami, Kohei; Nakatani, Yasuhiro; Nakagawa, Koya; Fujiwara, Hidenori; Kiss, Takayuki; Higashiya, Atsushi; Yamasaki, Atsushi; Kadono, Toshiharu; Imada, Shin; Tanaka, Arata; Tamasaku, Kenji; Yabashi, Makina; Ishikawa, Tetsuya; Matsumoto, Keisuke T.; Onimaru, Takahiro; Takabatake, Toshiro; Sekiyama, Akira

2017-12-01

We report experimentally observed linear dichroism in angle-resolved core-level photoemission spectra of PrIr2Zn20 and PrB6 with cubic symmetry. The different anisotropic 4f charge distributions between the compounds due to the crystalline-electric-field splitting are responsible for the difference in the linear dichroism, which has been verified by spectral simulations with the full multiplet theory for a single-site Pr3+ ion with cubic symmetry. The observed linear dichroism and polarization-dependent spectra in two different photoelectron directions for PrIr2Zn20 are reproduced by theoretical analysis for the Γ3 ground state, whereas those of the Pr 3d and 4d core levels indicate the Γ5 ground state for PrB6.

Progesterone receptor isoforms in the mammary gland of cats and dogs.

PubMed

Gracanin, A; de Gier, J; Zegers, K; Bominaar, M; Rutteman, G R; Schaefers-Okkens, A C; Kooistra, H S; Mol, J A

2012-12-01

Progesterone exerts its effect by binding to specific progesterone receptors (PR) within the cell. In dogs and cats, no data are available on PR isoforms as found in other species. We therefore investigated the sequence of the PR gene and encoded protein in dogs and cats, the expression of PR isoforms in mammary tissue using Western blots and the presence of PR in mammary tissue using immunohistochemistry. Comparison of the amino acid sequence of the canine and feline PR with human PR revealed major differences in the PR-B-specific upstream segment (BUS). However, the essential activation function 3 (AF3) domain was intact in the cat but mutated in the dog. The DNA and ligand-binding domains were highly similar among the species. In cats with fibroadenomatous hyperplasia (FAH), high expression of PR mRNA together with growth hormone (GH), GH receptor (GHR) and IGF-I mRNA was found in comparison with feline mammary carcinomas. Immunohistochemical analysis showed strong nuclear as well as cytoplasmic staining for PR in FAH. Western blot analysis revealed expression of the PR-A and PR-B isoforms in the feline mammary gland. In canine mammary tissue, the most abundant PR staining was found in proliferative zones of the mammary gland. Western blot analyses showed mainly staining for PR-A with lower PR-B staining. It is concluded that in dogs and cats both PR isoforms are expressed. The role of mutations found in the canine PR-B is discussed. © 2012 Blackwell Verlag GmbH.

Uptake Mechanisms of Eu(III) on Hydroxyapatite: A Potential Permeable Reactive Barrier Backfill Material for Trapping Trivalent Minor Actinides.

PubMed

Xu, Lin; Zheng, Tao; Yang, Shitong; Zhang, Linjuan; Wang, Jianqiang; Liu, Wei; Chen, Lanhua; Diwu, Juan; Chai, Zhifang; Wang, Shuao

2016-04-05

The permeable reactive barrier (PRB) technique has attracted an increasing level of attention for the in situ remediation of contaminated groundwater. In this study, the macroscopic uptake behaviors and microscopic speciation of Eu(III) on hydroxyapatite (HAP) were investigated by a combination of theoretical modeling, batch experiments, powder X-ray diffraction (PXRD) fitting, and X-ray absorption spectroscopy (XAS). The underlying removal mechanisms were identified to further assess the application potential of HAP as an effective PRB backfill material. The macroscopic analysis revealed that nearly all dissolved Eu(III) in solution was removed at pH 6.5 within an extremely short reaction time of 5 min. In addition, the thermodynamic calculations, desorption experiments, and PXRD and XAS analyses definitely confirmed the formation of the EuPO4·H2O(s) phase during the process of uptake of dissolved Eu(III) by HAP via the dissolution-precipitation mechanism. A detailed comparison of the present experimental findings and related HAP-metal systems suggests that the relative contribution of precipitation to the total Eu(III) removal increases as the P:Eu ratio decreases. The dosage of HAP-based PRB for the remediation of groundwater polluted by Eu(III) and analogous trivalent actinides [e.g., Am(III) and Cm(III)] should be strictly controlled depending on the dissolved Eu(III) concentration to obtain an optimal P:M (M represents Eu, Am, or Cm) ratio and treatment efficiency.

Cr(VI)-contaminated groundwater remediation with simulated permeable reactive barrier (PRB) filled with natural pyrite as reactive material: Environmental factors and effectiveness.

PubMed

Liu, Yuanyuan; Mou, Haiyan; Chen, Liqun; Mirza, Zakaria A; Liu, Li

2015-11-15

Permeable reactive barriers (PRBs) are efficient technologies for in situ remediation of contaminated groundwater, the effectiveness of which greatly depends on the reactive media filled. Natural pyrite is an iron sulfide material with a very low content of iron and sulfur, and a mining waste which is a potential material for Cr(VI) immobilization. In this study, we conducted a series of batch tests to research the effects of typical environmental factors on Cr(VI) removal and also simulated PRB filled with natural pyrite to investigate its effectiveness, in order to find a both environmentally and economically fine method for groundwater remediation. Batch tests showed that pH had the significant impact on Cr(VI) removal with an apparently higher efficiency under acidic conditions, and dissolved oxygen (DO) would inhibit Cr(VI) reduction; a relatively high initial Cr(VI) concentration would decrease the rate of Cr(VI) sorption; ionic strength and natural organic matter resulted in no significant effects on Cr(VI) removal. Column tests demonstrated that the simulated PRB with natural pyrite as the reactive media was considerably effective for removing Cr(VI) from groundwater, with a sorption capability of 0.6222 mg Cr per gram of natural pyrite at an initial Cr(VI) concentration of 10mg/L at pH 5.5 in an anoxic environment. Copyright © 2015 Elsevier B.V. All rights reserved.

Permeable bio-reactive barriers to address petroleum hydrocarbon contamination at subantarctic Macquarie Island.

PubMed

Freidman, Benjamin L; Terry, Deborah; Wilkins, Dan; Spedding, Tim; Gras, Sally L; Snape, Ian; Stevens, Geoffrey W; Mumford, Kathryn A

2017-05-01

A reliance on diesel generated power and a history of imperfect fuel management have created a legacy of petroleum hydrocarbon contamination at subantarctic Macquarie Island. Increasing environmental awareness and advances in contaminant characterisation and remediation technology have fostered an impetus to reduce the environmental risk associated with legacy sites. A funnel and gate permeable bio-reactive barrier (PRB) was installed in 2014 to address the migration of Special Antarctic Blend diesel from a spill that occurred in 2002, as well as older spills and residual contaminants in the soil at the Main Power House. The PRB gate comprised of granular activated carbon and natural clinoptilolite zeolite. Petroleum hydrocarbons migrating in the soil water were successfully captured on the reactive materials, with concentrations at the outflow of the barrier recorded as being below reporting limits. The nutrient and iron concentrations delivered to the barrier demonstrated high temporal variability with significant iron precipitation observed across the bed. The surface of the granular activated carbon was largely free from cell attachment while natural zeolite demonstrated patchy biofilm formation after 15 months following PRB installation. This study illustrates the importance of informed material selection at field scale to ensure that adsorption and biodegradation processes are utilised to manage the environmental risk associated with petroleum hydrocarbon spills. This study reports the first installation of a permeable bio-reactive barrier in the subantarctic. Copyright © 2017 Elsevier Ltd. All rights reserved.

The impact of the observation nudging and nesting on the simulated meteorology and ozone concentrations from WRF-SMOKE-CMAQ during DISCOVER-AQ 2013 Texas campaign

NASA Astrophysics Data System (ADS)

Choi, Y.; Li, X.; Czader, B.

2014-12-01

Three WRF simulations for the DISCOVER-AQ 2013 Texas campaign period (30 days in September) are performed to characterize uncertainties in the simulated meteorological and chemical conditions. These simulations differ in domain setup, and in performing observation nudging in WRF runs. There are around 7% index of agreement (IOA) gain in temperature and 9-12% boost in U-WIND and V-WIND when the observational nudging is employed in the simulation. Further performance gain from nested domains over single domain is marginal. The CMAQ simulations based on above WRF setups showed that the ozone performance slightly improved in the simulation for which objective analysis (OA) is carried out. Further IOA gain, though quite limited, is achieved with nested domains. This study shows that the high ozone episodes during the analyzed time periods were associated with the uncertainties of the simulated cold front passage, chemical boundary condition and small-scale temporal wind fields. All runs missed the observed high ozone values which reached above 150 ppb in La Porte on September 25, the only day with hourly ozone over 120 ppb. The failure is likely due to model's inability to catch small-scale wind shifts in the industrial zone, despite better wind directions in the simulations with nudging and nested domains. This study also shows that overestimated background ozone from the southerly chemical boundary is a critical source for the model's general overpredictions of the ozone concentrations from CMAQ during September of 2013. These results of this study shed a light on the necessity of (1) capturing the small-scale winds such as the onsets of bay-breeze or sea-breeze and (2) implementing more accurate chemical boundary conditions to reduce the simulated high-biased ozone concentrations. One promising remedy for (1) is implementing hourly observation nudging instead of the standard one which is done every three hours.

Consistent ozone-induced decreases in pasture forage quality across several grassland types and consequences for UK lamb production.

PubMed

Hayes, Felicity; Mills, Gina; Jones, Laurence; Abbott, John; Ashmore, Mike; Barnes, Jeremy; Neil Cape, J; Coyle, Mhairi; Peacock, Simon; Rintoul, Naomi; Toet, Sylvia; Wedlich, Kerstin; Wyness, Kirsten

2016-02-01

In this study we have demonstrated that rising background ozone has the potential to reduce grassland forage quality and explored the implications for livestock production. We analysed pasture samples from seven ozone exposure experiments comprising mesotrophic, calcareous, haymeadow and sanddune unimproved grasslands conducted in open-top chambers, solardomes and a field release system. Across all grassland types, there were significant increases in acid detergent fibre, crude fibre and lignin content with increasing ozone concentration, resulting in decreased pasture quality in terms of the metabolisable energy content of the vegetation. We derived a dose-response function for metabolisable energy of the grassland with ozone concentration, applicable to a range of grassland types, and used this to predict effects on pasture quality of UK vegetation at 1 km resolution using modelled ozone data for 2007 and for predicted higher average ozone concentrations in 2020. This showed a potential total reduction in lamb production in the UK of approximately 4% in 2020 compared to 2007. The largest impacts were in geographical areas of modest ozone increases between the two years, but where large numbers of lambs were present. For an individual farmer working to a very small cost margin this could represent a large reduction in profit, both in regions where the impacts per lamb and those where the impacts per km(2) of grazing land are largest. In the short term farmers could adapt their lamb management in response to changed forage quality by additional supplementary feed of high metabolisable energy content. Nationally this increase in annual additional feed in 2020 compared to 2007 would be 2,166 tonnes (an increase of 0.7%). Of added concern are the longer-term consequences of continual deterioration of pasture quality and the implications for changes in farming practices to compensate for potential reductions in livestock production capacity. Copyright © 2015 Elsevier B.V. All rights reserved.

78 FR 67333 - Performance Review Board Membership

Federal Register 2010, 2011, 2012, 2013, 2014

2013-11-12

.... Arnold William G. Bostic, Jr. Stephen B. Burke Joanne Buenzli Crane Susan R. Helper Ron S. Jarmin Enrique... Stephens Sonja Steptoe Frank A. Vitrano Katherine K. Wallman Adam Wilczewski The term of each PRB member...

LIDAR measurements of Arctic boundary layer ozone depletion events over the frozen Arctic Ocean

NASA Astrophysics Data System (ADS)

Seabrook, J. A.; Whiteway, J.; Staebler, R. M.; Bottenheim, J. W.; Komguem, L.; Gray, L. H.; Barber, D.; Asplin, M.

2011-09-01

A differential absorption light detection and ranging instrument (Differential Absorption LIDAR or DIAL) was installed on-board the Canadian Coast Guard Ship Amundsen and operated during the winter and spring of 2008. During this period the vessel was stationed in the Amundsen Gulf (71°N, 121-124°W), approximately 10-40 km off the south coast of Banks Island. The LIDAR was operated to obtain a continuous record of the vertical profile of ozone concentration in the lower atmosphere over the sea ice during the polar sunrise. The observations included several ozone depletion events (ODE's) within the atmospheric boundary layer. The strongest ODEs consisted of air with ozone mixing ratio less than 10 ppbv up to heights varying from 200 m to 600 m, and the increase to the background mixing ratio of about 35-40 ppbv occurred within about 200 m in the overlying air. All of the observed ODEs were connected to the ice surface. Back trajectory calculations indicated that the ODEs only occurred in air that had spent an extended period of time below a height of 500 m above the sea ice. Also, all the ODEs occurred in air with temperature below -25°C. Air not depleted in ozone was found to be associated with warmer air originating from above the surface layer.

Impacts of Central American Fires on Ozone Air Quality along the US Gulf Coast

NASA Astrophysics Data System (ADS)

Wang, S. C.; Wang, Y.; Estes, M. J.; Lei, R.; Talbot, R. W.

2017-12-01

Biomass burning in Central America is associated with agriculture activities and occurs regularly during April and May every year. Satellite observations have documented frequent transport of wildfire smoke from Mexico and Central America to the southern US, causing haze and exceedance of fine particle matter. However, the impacts of those fires on surface ozone in the US are poorly understood. This study uses both observations and modeling to examine the effects of the springtime Central America fire emissions on surface ozone over the Gulf coastal regions over a long-term time period (2002-2015). Passive tracer simulation in the nested-grid version of the GEOS-Chem chemical transport model over North America is used to identify the days when Central American fire plumes reached the US Gulf Coast. During the identified fire-impact days, Central American fires are estimated to result in an average of 9 ppbv enhancement of regional background ozone over the Houston-Galveston-Brazoria (HGB) region. Satellite-observed distributions of AOD and CO are used to examine the transport pathways and effects of those fires on atmospheric composition. Finally, we integrate satellite observations, ground measurements, and modeling to quantify the impact of Central American fires on springtime ozone air quality along the US Gulf Coast in terms of both long-term (2002-2015) mean and extreme cases.

Impacts of the large increase in international ship traffic 2000-2007 on tropospheric ozone and methane.

PubMed

Dalsøren, Stig B; Eide, Magnus S; Myhre, Gunnar; Endresen, Oyvind; Isaksen, Ivar S A; Fuglestvedt, Jan S

2010-04-01

The increase in civil world fleet ship emissions during the period 2000-2007 and the effects on key tropospheric oxidants are quantified using a global Chemical Transport Model (CTM). We estimate a substantial increase of 33% in global ship emissions over this period. The impact of ship emissions on tropospheric oxidants is mainly caused by the relatively large fraction of NOx in ship exhaust. Typical increases in yearly average surface ozone concentrations in the most impacted areas are 0.5-2.5 ppbv. The global annual mean radiative forcing due to ozone increases in the troposphere is 10 mWm(-2) over the period 2000-2007. We find global average tropospheric OH increase of 1.03% over the same period. As a result of this the global average tropospheric methane concentration is reduced by approximately 2.2% over a period corresponding to the turnover time. The resulting methane radiative forcing is -14 mWm(-2) with an additional contribution of -6 mWm(-2) from methane induced reduction in ozone. The net forcing of the ozone and methane changes due to ship emissions changes between 2000 and 2007 is -10 mWm(-2). This is significant compared to the net forcing of these components in 2000. Our findings support earlier observational studies indicating that ship traffic may be a major contributor to recent enhancement of background ozone at some coastal stations. Furthermore, by reducing global mean tropospheric methane by 40 ppbv over its turnover time it is likely to contribute to the recent observed leveling off in global mean methane concentration.

Frequency and Impact of Summertime Stratospheric Intrusions Over Maryland During DISCOVER-AQ (2011): New Evidence from NASA's GEOS-5 Simulations

NASA Technical Reports Server (NTRS)

Ott, Lesley E.; Duncan, Bryan N.; Thompson, Anne M.; Diskin, Glenn; Fasnacht, Zachary; Langford, Andrew O.; Lin, Meiyun; Molod, Andrea Mara; Nielsen, J. Eric; Pusede, Sally E.;

Sex-specific microRNA expression networks in an acute mouse model of ozone-induced lung inflammation.

PubMed

Fuentes, Nathalie; Roy, Arpan; Mishra, Vikas; Cabello, Noe; Silveyra, Patricia

2018-05-08

Sex differences in the incidence and prognosis of respiratory diseases have been reported. Studies have shown that women are at increased risk of adverse health outcomes from air pollution than men, but sex-specific immune gene expression patterns and regulatory networks have not been well studied in the lung. MicroRNAs (miRNAs) are environmentally sensitive posttranscriptional regulators of gene expression that may mediate the damaging effects of inhaled pollutants in the lung, by altering the expression of innate immunity molecules. Male and female mice of the C57BL/6 background were exposed to 2 ppm of ozone or filtered air (control) for 3 h. Female mice were also exposed at different stages of the estrous cycle. Following exposure, lungs were harvested and total RNA was extracted. We used PCR arrays to study sex differences in the expression of 84 miRNAs predicted to target inflammatory and immune genes. We identified differentially expressed miRNA signatures in the lungs of male vs. female exposed to ozone. In silico pathway analyses identified sex-specific biological networks affected by exposure to ozone that ranged from direct predicted gene targeting to complex interactions with multiple intermediates. We also identified differences in miRNA expression and predicted regulatory networks in females exposed to ozone at different estrous cycle stages. Our results indicate that both sex and hormonal status can influence lung miRNA expression in response to ozone exposure, indicating that sex-specific miRNA regulation of inflammatory gene expression could mediate differential pollution-induced health outcomes in men and women.

Associations between ozone and morbidity using the Spatial Synoptic Classification system

PubMed Central

2011-01-01

Background Synoptic circulation patterns (large-scale tropospheric motion systems) affect air pollution and, potentially, air-pollution-morbidity associations. We evaluated the effect of synoptic circulation patterns (air masses) on the association between ozone and hospital admissions for asthma and myocardial infarction (MI) among adults in North Carolina. Methods Daily surface meteorology data (including precipitation, wind speed, and dew point) for five selected cities in North Carolina were obtained from the U.S. EPA Air Quality System (AQS), which were in turn based on data from the National Climatic Data Center of the National Oceanic and Atmospheric Administration. We used the Spatial Synoptic Classification system to classify each day of the 9-year period from 1996 through 2004 into one of seven different air mass types: dry polar, dry moderate, dry tropical, moist polar, moist moderate, moist tropical, or transitional. Daily 24-hour maximum 1-hour ambient concentrations of ozone were obtained from the AQS. Asthma and MI hospital admissions data for the 9-year period were obtained from the North Carolina Department of Health and Human Services. Generalized linear models were used to assess the association of the hospitalizations with ozone concentrations and specific air mass types, using pollutant lags of 0 to 5 days. We examined the effect across cities on days with the same air mass type. In all models we adjusted for dew point and day-of-the-week effects related to hospital admissions. Results Ozone was associated with asthma under dry tropical (1- to 5-day lags), transitional (3- and 4-day lags), and extreme moist tropical (0-day lag) air masses. Ozone was associated with MI only under the extreme moist tropical (5-day lag) air masses. Conclusions Elevated ozone levels are associated with dry tropical, dry moderate, and moist tropical air masses, with the highest ozone levels being associated with the dry tropical air mass. Certain synoptic circulation patterns/air masses in conjunction with ambient ozone levels were associated with increased asthma and MI hospitalizations. PMID:21609456

How do background ozone concentrations affect the biosynthesis of rosmarinic acid in Melissa officinalis?

PubMed

Döring, Anne S; Pellegrini, Elisa; Della Batola, Michele; Nali, Cristina; Lorenzini, Giacomo; Petersen, Maike

2014-03-01

Lemon balm (Melissa officinalis; Lamiaceae) plants were exposed to background ozone (O3) dosages (80ppb for 5h), because high background levels of O3 are considered to be as harmful as episodic O3 peaks. Immediately at the end of fumigation the plants appeared visually symptomless, but necrotic lesions were observed later. The biosynthesis of rosmarinic acid (RA) comprises eight enzymes, among them phenylalanine ammonia-lyase (PAL), 4-coumarate:coenzyme A ligase (4CL), tyrosine aminotransferase (TAT) and rosmarinic acid synthase (RAS). The transcript levels of these genes have been investigated by quantitative RT-PCR. There was a quick up-regulation of all genes at 3h of O3 exposure, but at 24h from beginning of exposure (FBE) only RAS and PAL were up-regulated. The specific activity of RAS was closely correlated with a decrease of RA concentration in lemon balm leaves. The specific activity of PAL increased at 12h FBE to 163% in comparison to control levels. This work provides insight into the effect of O3 stress on the formation of the main phenolic ingredient of the pharmaceutically important plant M. officinalis. Copyright © 2013 Elsevier GmbH. All rights reserved.

Global Airborne Observations of Nitrogen Oxides and Ozone from the Atmospheric Tomography Mission

NASA Astrophysics Data System (ADS)

Thompson, C. R.; Peischl, J.; Ryerson, T. B.

2016-12-01

The Atmospheric Tomography (ATom) Mission is an ambitious airborne field campaign that will conduct measurements of an extensive suite of trace gases and aerosols from the NASA DC-8 platform over three years and four seasons. Flights will travel nearly pole-to-pole, traversing both the Pacific and Atlantic Oceans, while profiling continuously from 0.2 to 12 km altitude to provide nearly global-scale observations of greenhouse gases and reactive species. Measurements from ATom will provide an unprecedented test for current global chemistry-climate models (CCMs) and will inform further improvements to these models. In particular, reactive species, such as ozone, are difficult to represent accurately in CCMs. We will present global observations of reactive nitrogen compounds (NO, NO2, NOy) and ozone from the first deployment of the ATom Mission in August of 2016. Flights will intercept a wide variety of air masses with different pollution signatures, including aged biomass burning emissions from Siberian wildfires and anthropogenic outflow from the Asian mainland, which will contrast the relatively clean background atmosphere encountered in the high latitudes of the Northern and Southern Hemispheres. We will compare the composition of the NOy budgets across these variety of air masses and impacts on ozone.

77 FR 60146 - SES Performance Review Board

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2012-10-02

... NATIONAL TRANSPORTATION SAFETY BOARD SES Performance Review Board AGENCY: National Transportation... National Transportation Safety Board, Performance Review Board (PRB). FOR FURTHER INFORMATION CONTACT... Performance Review Boards. The board reviews and evaluates the initial appraisal of a senior executive's...

76 FR 70169 - SES Performance Review Board

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2011-11-10

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77 FR 35752 - Senior Executive Service Performance Review Board

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2012-06-14

... agency implement a performance appraisal system making senior executives accountable for organizational... DEPARTMENT OF TRANSPORTATION Surface Transportation Board Senior Executive Service Performance... Executive Service Performance Review Board (PRB). FOR FURTHER INFORMATION CONTACT: Paula Chandler, Director...

PERFORMANCE GOALS CASE STUDY: ELIZABETH CITY, NC

EPA Science Inventory

Permeable reactive barriers (PRB's) are an emerging, alternative in-situ approach for remediating groundwater contamination that combine subsurface fluid flow management with a passive chemical treatment zone. The few pilot and commercial installations which have been implemented...

Drill hole data for coal beds in the Powder River Basin, Montana and Wyoming

USGS Publications Warehouse

Haacke, Jon E.; Scott, David C.

2013-01-01

This report by the U.S. Geological Survey (USGS) of the Powder River Basin (PRB) of Montana and Wyoming is part of the U.S. Coal Resources and Reserves Assessment Project. Essential to that project was the creation of a comprehensive drill hole database that was used for coal bed correlation and for coal resource and reserve assessments in the PRB. This drill hole database was assembled using data from the USGS National Coal Resources Data System, several other Federal and State agencies, and selected mining companies. Additionally, USGS personnel manually entered lithologic picks into the database from geophysical logs of coalbed methane, oil, and gas wells. Of the 29,928 drill holes processed, records of 21,393 are in the public domain and are included in this report. The database contains location information, lithology, and coal bed names for each drill hole.

Application of the WRF-Chem model for the simulation of air quality over Cyprus

NASA Astrophysics Data System (ADS)

Kushta, Jonilda; Proestos, Yiannis; Georgiou, George; Christoudias, Theodoros; Lelieveld, Jos

2017-04-01

The fully coupled WRF-Chem (Weather Research and Forecasting with Chemistry) model is used to simulate air quality over Cyprus. Cyprus is an island country with complex topography, located in the eastern corner of East Mediterranean region, affected year-long by local, regional and long range transported pollution. An extensive sensitivity analysis of the model performance has been performed over the area of interest with three domains of respective grid spacing of 40, 8 and 2 km. Different configurations have been deployed regarding horizontal resolution, simulation timestep, boundary conditions, NOx emissions and speciation method of emitted NMVOCs (Non Methane Volatile Organic Compounds). The WRF-Chem model simulated hourly concentrations of air pollutants for a month-long period (July 2014) during which measurements are available over 13 stations (4 of which background stations, 1 industrial and 8 urban/traffic stations). The model was initialized with meteorological initial and boundary conditions (ICBC) using NCAR-NCEP's F Global Forecast System output (GFS) at a 1o x1o spatial resolution. The ICBC for the chemical species are derived from the MOZART global model results (2.5o x 2.5o). Both ICBCs datasets are updated every 6 hours. The emission inventory used in the study is the EDGAR-HTAP v2 dataset with a horizontal grid resolution of 0.1o × 0.1o, while an additional dataset with speciated NMVOCs (instead of summed volatile species) is also tested. The diurnal cycle of the atmospheric concentrations of ozone averaged over the island, exhibits a maximum of 114 μg/m3 when the boundary conditions are derived from MOZART and 94 μg/m3 when the boundary conditions are not included (local background and production), suggesting a constant inflow of ozone from long range transport of about 20 μg/m3. The contribution of pollution from regional sources is more pronounced at the western border due to the characteristic summer time north-northeasterly etesian flow that brings southward the pollution produced or accumulated over Eastern Europe, the Black sea and major upwind megacities (Istanbul, Athens etc). Ozone concentrations are overestimated in all stations indicating a possible overestimation of ozone from the global model (MOZART) that has also been discussed in other studies over neighbouring countries, or an excess of ozone production in the parent domain that includes all Eastern Mediterranean. Model results are influenced by the speciation of NMVOCs with the pre-speciated emission dataset resulting in lower ozone values by an average of 5 μg/m3. Lowering NOx emission brings ozone levels closer to observations; however this does not account for the overestimation of ozone since the respective comparison of NOx levels reveals strong underestimation of NOx (both NO and NO2) even before reducing them. Horizontal, vertical and temporal resolutions show smaller impact on changing the modelled patterns of ozone concentrations. The discrepancies between modelled and observed ozone over the main Cypriot urban areas point at the need for more detailed emission inventories, either in terms of spatial resolution and/or validation of absolute emitted values, and adjustments in the use of boundary conditions from global models.

AMBIENT AIR QUALITY AND SELECTED BIRTH DEFECTS, SEVEN COUNTY STUDY, TEXAS, 1997-2000

EPA Science Inventory

Background: A number of epidemiologic investigations have shown adverse effects of ambient air pollution on reproductive outcomes. A recent case-control study found associations between

second gestational month carbon monoxide and ozone exposure and elevated risks of selec...

Cardiac Effects of Seasonal Ambient Particulate Matter and Ozone Co-exposure in Rats

EPA Science Inventory

BackgroundThe potential for seasonal differences in the physicochemical characteristics of ambient particulate matter (PM) to modify interactive effects with gaseous pollutants has not been thoroughly examined. The purpose of this study was to compare cardiac responses in conscio...

Trend and variability of atmospheric ozone over middle Indo-Gangetic Plain: impacts of seasonality and precursor gases.

PubMed

Shukla, K; Srivastava, Prashant K; Banerjee, T; Aneja, Viney P

2017-01-01

Ozone dynamics in two urban background atmospheres over middle Indo-Gangetic Plain (IGP) were studied in two contexts: total columnar and ground-level ozone. In terms of total columnar ozone (TCO), emphases were made to compare satellite-based retrieval with ground-based observation and existing trend in decadal and seasonal variation was also identified. Both satellite-retrieved (Aura Ozone Monitoring Instrument-Differential Optical Absorption Spectroscopy (OMI-DOAS)) and ground-based observations (IMD-O 3 ) revealed satisfying agreement with OMI-DOAS observation over predicting TCO with a positive bias of 7.24 % under all-sky conditions. Minor variation between daily daytime (r = 0.54; R 2  = 29 %; n = 275) and satellite overpass time-averaged TCO (r = 0.58; R 2  = 34 %; n = 208) was also recognized. A consistent and clear seasonal trend in columnar ozone (2005-2015) was noted with summertime (March-June) maxima (Varanasi, 290.9 ± 8.8; Lucknow, 295.6 ± 9.5 DU) and wintertime (December-February) minima (Varanasi, 257.4 ± 10.1; Lucknow, 258.8 ± 8.8 DU). Seasonal trend decomposition based on locally weighted regression smoothing technique identified marginally decreasing trend (Varanasi, 0.0084; Lucknow, 0.0096 DU year -1 ) especially due to reduction in monsoon time minima and summertime maxima. In continuation to TCO, variation in ground-level ozone in terms of seasonality and precursor gases were also analysed from September 2014 to August 2015. Both stations registered similar pattern of variation with Lucknow representing slightly higher annual mean (44.3 ± 30.6; range, 1.5-309.1 μg/m 3 ) over Varanasi (38.5 ± 17.7; range, 4.9-104.2 μg/m 3 ). Variation in ground-level ozone was further explained in terms water vapour, atmospheric boundary layer height and solar radiation. Ambient water vapour content was found to associate negatively (r = -0.28, n = 284) with ground-level ozone with considerable seasonal variation in Varanasi. Implication of solar radiation on formation of ground-level ozone was overall positive (Varanasi, 0.60; Lucknow, 0.26), while season-specific association was recorded in case of atmospheric boundary layer.

Trans-Pacific Air Pollution and NAAQS Attainment: Domestic and International Policy Options

NASA Astrophysics Data System (ADS)

Dolsak, N.; Jaegle, L.

2002-12-01

Observational data and models of global air pollution increasingly indicate that Asian air pollution caused by fossil fuel burning is transported across the Pacific, thereby affecting local air quality in the United States. This may have policy ramifications for a number of counties in the U.S. struggling to meet the NAAQS. This problem will be exacerbated as the EPA tightens the standards for Ozone and PM. As the new 8-hour, 80 ppb ozone standard and the new PM2.5 standards are implemented, the number of counties considered to be in non-attainment is estimated to double (for ozone) and quadruple (for PM2.5), respectively. State Implementation Plans that rely only on local emission reductions may not be enough to meet the new NAAQS if a considerable proportion of the background concentrations come from Asia or other distant sources. Further, reducing emissions locally may not be the most cost-effective way of meeting the new EPA standards. This presentation will draw on observational data in the western U.S. and global models, such as GEOS-CHEM, to examine the significance of trans-pacific pollution (background pollution as well as episodic impacts) to air quality in the Western United States in their attempts to meet the new NAAQS for Ozone and Particulate Matter. The size of Asian economies, their reliance on fossil fuels, and their rapid industrialization suggests that the importance of trans-pacific air pollution will increase. This presentation will examine policy implications of Asian emissions under three of the IPCC future emission scenarios. We will also identify an array of domestic policies that States and counties in non-attainment areas may consider to reduce the concentrations of ozone and PM. Further, we will examine the potential for reducing local concentrations by devising policy instruments for reducing emissions where they can be reduced at a lower cost. For this work, we will draw on policy experience from regional air pollution in the European Union and evaluate options for devising policy instruments within the institutional framework of the Asia Pacific Economic Cooperation.

Analytical solutions of one-dimensional multispecies reactive transport in a permeable reactive barrier-aquifer system

NASA Astrophysics Data System (ADS)

Mieles, John; Zhan, Hongbin

2012-06-01

The permeable reactive barrier (PRB) remediation technology has proven to be more cost-effective than conventional pump-and-treat systems, and has demonstrated the ability to rapidly reduce the concentrations of specific chemicals of concern (COCs) by up to several orders of magnitude in some scenarios. This study derives new steady-state analytical solutions to multispecies reactive transport in a PRB-aquifer (dual domain) system. The advantage of the dual domain model is that it can account for the potential existence of natural degradation in the aquifer, when designing the required PRB thickness. The study focuses primarily on the steady-state analytical solutions of the tetrachloroethene (PCE) serial degradation pathway and secondly on the analytical solutions of the parallel degradation pathway. The solutions in this study can also be applied to other types of dual domain systems with distinct flow and transport properties. The steady-state analytical solutions are shown to be accurate and the numerical program RT3D is selected for comparison. The results of this study are novel in that the solutions provide improved modeling flexibility including: 1) every species can have unique first-order reaction rates and unique retardation factors, and 2) daughter species can be modeled with their individual input concentrations or solely as byproducts of the parent species. The steady-state analytical solutions exhibit a limitation that occurs when interspecies reaction rate factors equal each other, which result in undefined solutions. Excel spreadsheet programs were created to facilitate prompt application of the steady-state analytical solutions, for both the serial and parallel degradation pathways.

Signalling in the epidermis: the E2F cell cycle regulatory pathway in epidermal morphogenesis, regeneration and transformation.

PubMed

Ivanova, Iordanka A; D'Souza, Sudhir J A; Dagnino, Lina

2005-01-01

The epidermis is the outermost layer in the skin, and it is the first line of defence against the environment. The epidermis also provides a barrier against loss of fluids and electrolytes, which is crucial for life. Essential in the maintenance of this tissue is its ability to continually self-renew and regenerate after injury. These two characteristics are critically dependent on the ability of the principal epidermal cell type, the keratinocyte, to proliferate and to respond to differentiation cues. Indeed, the epidermis is a multilayered tissue composed of keratinocyte stem cells and their differentiated progeny. Central for the control of cell proliferation is the E2F transcription factor regulatory network. This signaling network also includes cyclins, cdk, cdk inhibitors and the retinoblastoma (pRb) family of proteins. The biological importance of the E2F/pRb pathway is emphasized by the fact that a majority of human tumours exhibit alterations that disrupt the ability of pRb proteins to inhibit E2F, leading to permanent activation of the latter. Further, E2F is essential for normal epidermal regeneration after injury. Other member of the E2F signaling pathway are also involved in epidermal development and pathophysiology. Thus, whereas the pRb family of proteins is essential for epidermal morphogenesis, abnormal regulation of cyclins and E2F proteins results in tumorgenesis in this tissue. In this review, we discuss the role of each member of this important growth regulatory network in epidermal formation, homeostasis and carcinogenesis.

Signalling In The Epidermis: The E2f Cell Cycle Regulatory Pathway In Epidermal Morphogenesis, Regeneration And Transformation

PubMed Central

2005-01-01

The epidermis is the outermost layer in the skin, and it is the first line of defence against the environment. The epidermis also provides a barrier against loss of fluids and electrolytes, which is crucial for life. Essential in the maintenance of this tissue is its ability to continually self-renew and regenerate after injury. These two characteristics are critically dependent on the ability of the principal epidermal cell type, the keratinocyte, to proliferate and to respond to differentiation cues. Indeed, the epidermis is a multilayered tissue composed of keratinocyte stem cells and their differentiated progeny. Central for the control of cell proliferation is the E2F transcription factor regulatory network. This signaling network also includes cyclins, cdk, cdk inhibitors and the retinoblastoma (pRb) family of proteins. The biological importance of the E2F/pRb pathway is emphasized by the fact that a majority of human tumours exhibit alterations that disrupt the ability of pRb proteins to inhibit E2F, leading to permanent activation of the latter. Further, E2F is essential for normal epidermal regeneration after injury. Other member of the E2F signaling pathway are also involved in epidermal development and pathophysiology. Thus, whereas the pRb family of proteins is essential for epidermal morphogenesis, abnormal regulation of cyclins and E2F proteins results in tumorgenesis in this tissue. In this review, we discuss the role of each member of this important growth regulatory network in epidermal formation, homeostasis and carcinogenesis. PMID:15951853

Functional synergy between DP-1 and E2F-1 in the cell cycle-regulating transcription factor DRTF1/E2F.

PubMed Central

Bandara, L R; Buck, V M; Zamanian, M; Johnston, L H; La Thangue, N B

1993-01-01

It is widely believed that the cellular transcription factor DRTF1/E2F integrates cell cycle events with the transcription apparatus because during cell cycle progression in mammalian cells it interacts with molecules that are important regulators of cellular proliferation, such as the retinoblastoma tumour suppressor gene product (pRb), p107, cyclins and cyclin-dependent kinases. Thus, pRb, which negatively regulates early cell cycle progression and is frequently mutated in tumour cells, and the Rb-related protein p107, bind to and repress the transcriptional activity of DRTF1/E2F. Viral oncoproteins, such as adenovirus E1a and SV40 large T antigen, overcome such repression by sequestering pRb and p107 and in so doing are likely to activate genes regulated by DRTF1/E2F, such as cdc2, c-myc and DHFR. Two sequence-specific DNA binding proteins, E2F-1 and DP-1, which bind to the E2F site, contain a small region of similarity. The functional relationship between them has, however, been unclear. We report here that DP-1 and E2F-1 exist in a DNA binding complex in vivo and that they bind efficiently and preferentially as a heterodimer to the E2F site. Moreover, studies in yeast and Drosophila cells indicate that DP-1 and E2F-1 interact synergistically in E2F site-dependent transcriptional activation. Images PMID:8223441

Transforming properties of Felis catus papillomavirus type 2 E6 and E7 putative oncogenes in vitro and their transcriptional activity in feline squamous cell carcinoma in vivo

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

Altamura, Gennaro, E-mail: gennaro.altamura@unina.it; Corteggio, Annunziata, E-mail: ancorteg@unina.it; Pacini, Laura, E-mail: PaciniL@students.iarc.fr

Felis catus papillomavirus type 2 (FcaPV2) DNA is found in feline cutaneous squamous cell carcinomas (SCCs); however, its biological properties are still uncharacterized. In this study, we successfully expressed FcaPV2 E6 and E7 putative oncogenes in feline epithelial cells and demonstrated that FcaPV2 E6 binds to p53, impairing its protein level. In addition, E6 and E7 inhibited ultraviolet B (UVB)-triggered accumulation of p53, p21 and pro-apoptotic markers such as Cleaved Caspase3, Bax and Bak, suggesting a synergistic action of the virus with UV exposure in tumour pathogenesis. Furthermore, FcaPV2 E7 bound to feline pRb and impaired pRb levels, resulting inmore » upregulation of the downstream pro-proliferative genes Cyclin A and Cdc2. Importantly, we demonstrated mRNA expression of FcaPV2 E2, E6 and E7 in feline SCC samples, strengthening the hypothesis of a causative role in the development of feline SCC. - Highlights: • FcaPV2 E6 binds to and deregulates feline p53 protein. • FcaPV2 E7 binds to and deregulates feline pRb protein. • FcaPV2 oncogenes inhibit UVB-induced apoptosis. • FcaPV2 E6E7 and E7 increase the lifespan of primary cells. • FcaPV2 E2, E6 and E7 are expressed at the mRNA level in feline SCC in vivo.« less

Sodium alginate/graphene oxide hydrogel beads as permeable reactive barrier material for the remediation of ciprofloxacin-contaminated groundwater.

PubMed

Zhao, Pingping; Yu, Fei; Wang, Ruoyu; Ma, Yao; Wu, Yanqing

2018-06-01

The wide occurrence of antibiotics in groundwater has raised serious concerns due to their impacts on humans and the ecosystem. Most of the research in groundwater remediation focuses on the exploitation of nano-materials. However, nano-materials have several disadvantages such as high production cost, rapid reduction in permeability, disposal problems, and high sensitivity to environmental conditions. To solve these issues, novel sodium alginate/graphene oxide hydrogel beads (GSA) were synthesised and their effectiveness as permeable reactive barrier (PRB) backfill material in the remediation of ciprofloxacin (CPX)-contaminated groundwater was tested. The adsorption of CPX onto GSA followed the pseudo-second-order kinetic model. The isotherm data followed the Freundlich model. The maximum adsorption capacity was 100 mg g -1 at pH 7.0. The adsorption process was sensitive to contact time, initial CPX concentration and ionic strength. However, it was not pH sensitive. Hydrophobic interaction, electrostatic interaction, ion exchange, H-bonding, and pore filling were proposed to be the main adsorption mechanisms. The effects of flow rate, influent CPX concentration, and ionic strength on the performance of PRB were confirmed through flow-through column experiments and by using a chemical non-equilibrium two-site model. Accordingly, a proper PRB was designed based on hydrogeological conditions. Finally, the lifetime and cost of the PRBs were calculated. The results obtained provided concrete evidence that GSA is a promising adsorbent material for PRBs applications in the remediation of CPX-contaminated groundwater. Copyright © 2018 Elsevier Ltd. All rights reserved.

75 FR 69706 - SES Performance Review Board

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-15

... NATIONAL TRANSPORTATION SAFETY BOARD SES Performance Review Board AGENCY: National Transportation... National Transportation Safety Board Performance Review Board (PRB). FOR FURTHER INFORMATION CONTACT: Emily... Review Boards. The board reviews and evaluates the initial appraisal of a senior executive's performance...

EVALUATION OF PERMEABLE REACTIVE BARRIER PERFORMANCE

EPA Science Inventory

The permeable reactive barrier (PRB) technology represents a passive option for long-term treatment of ground-water contamination. PRBs are a potentially more cost-effective treatment option for a variety of dissolved contaminants, such as certain types of chlorinated solvents, ...

Imaging, Behavior and Endocrine Analysis of “Jealousy” in a Monogamous Primate

PubMed Central

Maninger, Nicole; Mendoza, Sally P.; Williams, Donald R.; Mason, William A.; Cherry, Simon R.; Rowland, Douglas J.; Schaefer, Thomas; Bales, Karen L.

2018-01-01

Understanding the neurobiology of social bonding in non-human primates is a critical step in understanding the evolution of monogamy, as well as understanding the neural substrates for emotion and behavior. Coppery titi monkeys (Callicebus cupreus) form strong pair bonds, characterized by selective preference for their pair mate, mate-guarding, physiological and behavioral agitation upon separation, and social buffering. Mate-guarding, or the “maintenance” phase of pair bonding, is relatively under-studied in primates. In the current study, we used functional imaging to examine how male titi monkeys viewing their pair mate in close proximity to a stranger male would change regional cerebral glucose metabolism. We predicted that this situation would challenge the pair bond and induce “jealousy” in the males. Animals were injected with [18F]-fluorodeoxyglucose (FDG), returned to their cage for 30 min of conscious uptake, placed under anesthesia, and then scanned for 1 hour on a microPET P4 scanner. During the FDG uptake, males (n=8) had a view of either their female pair mate next to a stranger male (“jealousy” condition) or a stranger female next to a stranger male (control condition). Blood and cerebrospinal fluid samples were collected and assayed for testosterone, cortisol, oxytocin, and vasopressin. Positron emission tomography (PET) was co-registered with structural magnetic resonance imaging (MRI), and region of interest analysis was carried out. Bayesian multivariate multilevel analyses found that the right lateral septum (Pr(b>0)=93%), left posterior cingulate cortex (Pr(b>0)=99%), and left anterior cingulate (Pr(b>0)=96%) showed higher FDG uptake in the jealousy condition compared to the control condition, while the right medial amygdala (Pr(b>0)=85%) showed lower FDG uptake. Plasma testosterone and cortisol concentrations were higher during the jealousy condition. During the jealousy condition, duration of time spent looking across at the pair mate next to a stranger male was associated with higher plasma cortisol concentrations. The lateral septum has been shown to be involved in mate-guarding and mating-induced aggression in monogamous rodents, while the cingulate cortex has been linked to territoriality. These neural and physiological changes may underpin the emotion of jealousy, which can act in a monogamous species to preserve the long-term integrity of the pair. PMID:29682503

Full scale calcium bromide injection with subsequent mercury oxidation and removal within wet flue gas desulphurization system: Experience at a 700 MW coal-fired power facility

NASA Astrophysics Data System (ADS)

Berry, Mark Simpson

The Environmental Protection Agency promulgated the Mercury and Air Toxics Standards rule, which requires that existing power plants reduce mercury emissions to meet an emission rate of 1.2 lb/TBtu on a 30-day rolling average and that new plants meet a 0.0002 lb/GWHr emission rate. This translates to mercury removals greater than 90% for existing units and greater than 99% for new units. Current state-of-the-art technology for the control of mercury emissions uses activated carbon injected upstream of a fabric filter, a costly proposition. For example, a fabric filter, if not already available, would require a 200M capital investment for a 700 MW size unit. A lower-cost option involves the injection of activated carbon into an existing cold-side electrostatic precipitator. Both options would incur the cost of activated carbon, upwards of 3M per year. The combination of selective catalytic reduction (SCR) reactors and wet flue gas desulphurization (wet FGD) systems have demonstrated the ability to substantially reduce mercury emissions, especially at units that burn coals containing sufficient halogens. Halogens are necessary for transforming elemental mercury to oxidized mercury, which is water-soluble. Plants burning halogen-deficient coals such as Power River Basin (PRB) coals currently have no alternative but to install activated carbon-based approaches to control mercury emissions. This research consisted of investigating calcium bromide addition onto PRB coal as a method of increasing flue gas halogen concentration. The treated coal was combusted in a 700 MW boiler and the subsequent treated flue gas was introduced into a wet FGD. Short-term parametric and an 83-day longer-term tests were completed to determine the ability of calcium bromine to oxidize mercury and to study the removal of the mercury in a wet FGD. The research goal was to show that calcium bromine addition to PRB coal was a viable approach for meeting the Mercury and Air Toxics Standards rule for existing boilers. The use of calcium bromide injection as an alternative to activated carbon approaches could save millions of dollars. The technology application described herein has the potential to reduce compliance cost by $200M for a 700 MW facility burning PRB coal.

Progestin effects on expression of AKR1C1-AKR1C3, SRD5A1 and PGR in the Z-12 endometriotic epithelial cell line.

PubMed

Beranič, Nataša; Lanišnik Rižner, Tea

2013-02-25

Endometriosis is defined as the presence of endometrial glands and stroma outside the uterine cavity. This disease is associated with diminished protective effects of progesterone, which are usually explained by inadequate activation of progesterone receptors and also enhanced pre-receptor metabolism of progesterone. Endometriosis is often treated with progestins, which act as progesterone receptor agonists, although their exact mechanisms of action are not completely understood. The aim of the present study was to investigate how the progestins medroxyprogesterone acetate, dydrogesterone and dienogest, as well as progesterone, impact on the expression of genes of pre-receptor progesterone metabolism in Z-12 epithelial cell line, a model system of peritoneal endometriosis. Our data demonstrate that these progestins affect local pre-receptor metabolism to a different extent. The most favorable effects were seen for dydrogesterone and dienogest, where the first, dydrogesterone, significantly reduced SRD5A1, AKR1C2 and AKR1C3 expression, and additionally had a nonsignificant impact on progesterone receptor B (PR-B) protein levels. This might slow down the first step of pre-receptor metabolism, the conversion of progesterone to 5α-dihydroprogestrone by SRD5A1, and it might also affect further reduction of 3-keto and 20-keto groups catalyzed by AKR1C2 and AKR1C3. Similarly favorable effects were seen for dienogest, which promoted significant reduction of AKR1C1 and AKR1C2 expression and also showed no effect on PR-B protein levels. Different effects were seen for progesterone, which significantly decreased SRD5A1, PR-B and HSD17B2 protein levels. In contrast, treatment with medroxyprogesterone acetate resulted in increased AKR1C1 expression and decreased levels of PR-B, which might lead to enhanced progesterone metabolism and reduced signaling through progesterone receptors. Altogether, our data in this Z-12 cell model suggest that the beneficial effects of treatment with progestin observed in endometriosis patients might arise from decreased pre-receptor metabolism of the protective progesterone by the SRD5A1 and AKR1C enzymes. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Lidar measurements of ozone and aerosol distributions during the 1992 airborne Arctic stratospheric expedition

NASA Technical Reports Server (NTRS)

Browell, Edward V.; Butler, Carolyn F.; Fenn, Marta A.; Grant, William B.; Ismail, Syed; Carter, Arlen F.

1994-01-01

The NASA Langley airborne differential absorption lidar system was operated from the NASA Ames DC-8 aircraft during the 1992 Airborne Arctic Stratospheric Expedition to investigate the distribution of stratospheric aerosols and ozone (O3) across the Arctic vortex from January to March 1992. Aerosols from the Mt. Pinatubo eruption were found outside and inside the Arctic vortex with distinctly different scattering characteristics and spatial distributions in the two regions. The aerosol and O3 distributions clearly identified the edge of the vortex and provided additional information on vortex dynamics and transport processes. Few polar stratospheric clouds were observed during the AASE-2; however, those that were found had enhanced scattering and depolarization over the background Pinatubo aerosols. The distribution of aerosols inside the vortex exhibited relatively minor changes during the AASE-2. Ozone depletion inside the vortex as limited to less than or equal to 20 percent in the altitude region from 15-20 km.

The chemistry of bromine in the stratosphere: Influence of a new rate constant for the reaction BrO + HO2

NASA Technical Reports Server (NTRS)

Pirre, Michel; Marceau, Francois J.; Lebras, Georges; Maguin, Francoise; Poulet, Gille; Ramaroson, Radiela

1994-01-01

The impact of new laboratory data for the reaction BrO + HO2 yields HOBr + O2 in the depletion of global stratospheric ozone has been estimated using a one-dimensional photochemical model taking into account the heterogeneous reaction on sulphate aerosols which converts N2O5 into HNO3. Assuring an aerosol loading 2 times as large as the 'background' and a reaction probability of 0.1 for the above heterogeneous reaction, the 6 fold increase in the measured rate constant for the reaction of BrO with HO2 increases the computed depletion of global ozone produced by 20 ppt of total bromine from 2.01 percent to 2.36 percent. The use of the higher rate constant increases the HOBr mixing ratio and makes the bromine partitioning and the ozone depletion very sensitive to the branching ratio of the potential channel forming HBr in the BrO + HO2 reaction.

Tropospheric Bromine Chemistry: Implications for Present and Pre-industrial Ozone and Mercury

NASA Technical Reports Server (NTRS)

Parella, J. P.; Jacob, D. J.; Liang, Q.; Zhang, Y.; Mickley, L. J.; Miller, B.; Evans, M. J.; Yang, X.; Pyle, J. A.; Theys, N.;

Overview of the O3M SAF GOME-2 operational atmospheric composition and UV radiation data products and data availability

NASA Astrophysics Data System (ADS)

Hassinen, S.; Balis, D.; Bauer, H.; Begoin, M.; Delcloo, A.; Eleftheratos, K.; Gimeno Garcia, S.; Granville, J.; Grossi, M.; Hao, N.; Hedelt, P.; Hendrick, F.; Hess, M.; Heue, K.-P.; Hovila, J.; Jønch-Sørensen, H.; Kalakoski, N.; Kiemle, S.; Kins, L.; Koukouli, M. E.; Kujanpää, J.; Lambert, J.-C.; Lerot, C.; Loyola, D.; Määttä, A.; Pedergnana, M.; Pinardi, G.; Romahn, F.; van Roozendael, M.; Lutz, R.; De Smedt, I.; Stammes, P.; Steinbrecht, W.; Tamminen, J.; Theys, N.; Tilstra, L. G.; Tuinder, O. N. E.; Valks, P.; Zerefos, C.; Zimmer, W.; Zyrichidou, I.

2015-07-01

The three GOME-2 instruments will provide unique and long data sets for atmospheric research and applications. The complete time period will be 2007-2022, including the period of ozone depletion as well as the beginning of ozone layer recovery. Besides ozone chemistry, the GOME-2 products are important e.g. for air quality studies, climate modeling, policy monitoring and hazard warnings. The heritage for GOME-2 is in the ERS/GOME and Envisat/SCIAMACHY instruments. The current Level 2 (L2) data cover a wide range of products such as trace gas columns (NO2, BrO, H2CO, H2O, SO2), tropospheric columns of NO2, total ozone columns and vertical ozone profiles in high and low spatial resolution, absorbing aerosol indices from the main science channels as well as from the polarization channels (AAI, AAI-PMD), Lambertian-equivalent reflectivity database, clear-sky and cloud-corrected UV indices and surface UV fields with different weightings and photolysis rates. The Ozone Monitoring and Atmospheric Composition Satellite Application Facility (O3M SAF) processing and data dissemination is operational and running 24/7. Data quality is quarantined by the detailed review processes for the algorithms, validation of the products as well as by a continuous quality monitoring of the products and processing. This is an overview paper providing the O3M SAF project background, current status and future plans to utilization of the GOME-2 data. An important focus is the provision of summaries of the GOME-2 products including product principles and validation examples together with the product sample images. Furthermore, this paper collects the references to the detailed product algorithm and validation papers.

A Comparative Analysis of Antimicrobial Property of Wine and Ozone with Calcium Hydroxide and Chlorhexidine

PubMed Central

Ebenezar, A. V. Rajesh; Anand, Nirupa; Mary, A.Vinita; Mony, Bejoy

2015-01-01

Background The antibacterial properties of wine and ozone have been established but their antibacterial efficacies against endodontic pathogens are yet to be ascertained. Aim The purpose of this study is to comparatively evaluate the antibacterial property of ozonated water, white wine (14%) and de-alcoholised white wine. Materials and Methods S.mutans and E.faecalis were subcultured and inoculated in a nutrient broth for 24 hours. The following groups were formulated: Group 1A:2% Chlorhexidine (Control group); Group 1B:White wine; Group 1C:Dealcoholised white wine; Group 1D:Ozonated water; Group 2A: Ca(OH)2 + Chlorhexidine (Control group); Group 2B: White wine + Ca(OH)2; Group 2C:De-alcoholised White wine + Ca(OH)2 + chlorhexidine; Group 2D:White wine + Ca(OH)2 + chlorhexidine and group 2E: Dealcoholised white wine + Ca(OH)2 + chlorhexidine. The samples were allowed to diffuse into the culture medium for two hours, later the S. mutans were streaked on to the blood agar medium and the E. faecalis were streaked on to the Muller Hilton agar medium and incubated for 48 hours at 370C the zone of inhibition was measured after 48 hours. Results There was no growth of microorganisms seen with ozonated water. Chlorhexidine showed large zone of inhibition compared to the other groups. White wine has better antimicrobial property than de-alcoholised white wine, but when mixed with calcium hydroxide the dealcoholised white wine has better action against the microorganisms. Conclusion Ozonated water has the best antibacterial property and the antibacterial action of Calcium hydroxide is enhanced when it is mixed with de-alcoholised white wine. PMID:26266206

Comparison of the effects of formaldehyde and gaseous ozone on HBV-contaminated hospital quilts

PubMed Central

Guo, Dan; Li, Ziqiong; Jia, Bei; Che, Xiaoqiong; Song, Tianshuang; Huang, Wenxiang

2015-01-01

Background: Besides being highly infectious, Hepatitis B virus (HBV) is a major cause of liver disease worldwide. In hospital settings, it is easy for the environment and quilts to be contaminated by HBV patient blood and body fluids. Therefore, HBV can be transmitted to other patients via contaminated environmental surfaces or quilts, resulting in an HBV nosocomial infection. Formaldehyde and ozone are commonly used disinfectants that may influence this infectious situation. Objective: To investigate the clinical effectiveness of formaldehyde and gaseous ozone for the terminal cleaning of hospital quilts contaminated by HBV. Methods: Thin cloth and thick cotton soaked with the serum from high HBV copy number patients were prepared and disinfected using formaldehyde fumigation and gaseous ozone at different times. The copy numbers of HBV DNA in the HBV-contaminated cloth and cotton samples were measured quantitatively with fluorescent quantitative polymerase chain reaction (PCR). Results: When gaseous ozone was used to disinfect HBV-contaminated quilts for 23 minutes (min), 36 min, 49 min, and 90 min, the HBV DNA copy number displayed no significant decrease compared with the copy number before disinfection (P > 0.05). In comparison, the copy number of the HBV DNA in the cloth group decreased significantly (P < 0.05) after formaldehyde fumigation disinfection for 1 hour (h), and there was no difference when longer times and increased concentrations were used. In the thick cotton group, there was also a significant decrease (P < 0.05) of the HBV DNA copy numbers, but the decrease was not as dramatic. In addition, in this group, the disinfection effect observed at 4 h was the strongest. Conclusions: The application of ozone to disinfect HBV-contaminated hospital quilts possibly has no effect, whereas, formaldehyde oxide fumigation effectively reduced HBV copy numbers. PMID:26770591

76 FR 39401 - Performance Review Board

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MICROBIAL CHARACTERIZATION OF MANURE BASED PERMEABLE REACTIVE BARRIER

EPA Science Inventory

The implementation of permeable reactive barriers (PRB) provides a viable option for the remediation of contaminants of environmental significance such as dissolved metals (i.e., chromium), chlorinated solvents, and nitrate/ammonia. The designs of PRBs are usually based on the a...

Gridded global surface ozone metrics for atmospheric chemistry model evaluation

NASA Astrophysics Data System (ADS)

Sofen, E. D.; Bowdalo, D.; Evans, M. J.; Apadula, F.; Bonasoni, P.; Cupeiro, M.; Ellul, R.; Galbally, I. E.; Girgzdiene, R.; Luppo, S.; Mimouni, M.; Nahas, A. C.; Saliba, M.; Tørseth, K.; Wmo Gaw, Epa Aqs, Epa Castnet, Capmon, Naps, Airbase, Emep, Eanet Ozone Datasets, All Other Contributors To

2015-07-01

The concentration of ozone at the Earth's surface is measured at many locations across the globe for the purposes of air quality monitoring and atmospheric chemistry research. We have brought together all publicly available surface ozone observations from online databases from the modern era to build a consistent dataset for the evaluation of chemical transport and chemistry-climate (Earth System) models for projects such as the Chemistry-Climate Model Initiative and Aer-Chem-MIP. From a total dataset of approximately 6600 sites and 500 million hourly observations from 1971-2015, approximately 2200 sites and 200 million hourly observations pass screening as high-quality sites in regional background locations that are appropriate for use in global model evaluation. There is generally good data volume since the start of air quality monitoring networks in 1990 through 2013. Ozone observations are biased heavily toward North America and Europe with sparse coverage over the rest of the globe. This dataset is made available for the purposes of model evaluation as a set of gridded metrics intended to describe the distribution of ozone concentrations on monthly and annual timescales. Metrics include the moments of the distribution, percentiles, maximum daily eight-hour average (MDA8), SOMO35, AOT40, and metrics related to air quality regulatory thresholds. Gridded datasets are stored as netCDF-4 files and are available to download from the British Atmospheric Data Centre (doi:10.5285/08fbe63d-fa6d-4a7a-b952-5932e3ab0452). We provide recommendations to the ozone measurement community regarding improving metadata reporting to simplify ongoing and future efforts in working with ozone data from disparate networks in a consistent manner.

Influence of Urbanicity and County Characteristics on the Association between Ozone and Asthma Emergency Department Visits in North Carolina

EPA Science Inventory

Background: Air pollution epidemiology studies, often conducted in large metropolitan areas due to proximity to regulatory monitors, are limited in their ability to examine potential associations between air pollution exposures and health effects in rural locations. Methods: In a...

Fumigation efficacy and emission reduction using low-permeability film in orchard soil fumigation

USDA-ARS?s Scientific Manuscript database

BACKGROUND: Many orchards in California, USA, apply fumigants to soil before replanting to reduce the impact of pest pressure or replanting disease on new tree establishment. Emission control of alternative fumigants to methyl bromide is mandatory in air quality (ozone) non-attainment areas. This s...

Assessment of the Impact of The East Asian Summer Monsoon on the Air Quality Over China

NASA Astrophysics Data System (ADS)

Hao, Nan; Ding, Aijun; Safieddine, Sarah; Valks, Pieter; Clerbaux, Cathy; Trautmann, Thomas

2016-04-01

Air pollution is one of the most important environmental problems in developing Asian countries like China. In this region, studies showed that the East Asian monsoon plays a significant role in characterizing the temporal variation and spatial patterns of air pollution, since monsoon is a major atmospheric system affecting air mass transport, convection, and precipitation. Knowledge gaps still exist in the understanding of Asian monsoon impact on the air quality in China under the background of global climate change. For the first time satellite observations of tropospheric ozone and its precursors will be integrated with the ground-based, aircraft measurements of air pollutants and model simulations to study the impact of the East Asian monsoon on air quality in China. We apply multi-platform satellite observations by the GOME-2, IASI, and MOPITT instruments to analyze tropospheric ozone and CO, precursors of ozone (NO2, HCHO and CHOCHO) and other related trace gases over China. Two years measurements of air pollutants including NO2, HONO, SO2, HCHO and CHOCHO at a regional back-ground site in the western part of the Yangtze River Delta (YRD) in eastern China will be presented. The potential of using the current generation of satellite instruments, ground-based instruments and aircraft to monitor air quality changes caused by the East Asian monsoon circulation will be presented. Preliminary comparison results between satellite measurement and limited but valuable ground-based and aircraft measurements will also be showed.

Impact of near-surface atmospheric composition on ozone formation in Russia

NASA Astrophysics Data System (ADS)

Berezina, Elena; Moiseenko, Konstantin; Skorokhod, Andrey; Belikov, Igor; Pankratova, Natalia; Elansky, Nikolai

2017-04-01

One of the consequences of the human impact on the atmosphere is increasing in tropospheric ozone concentration, with the highest ozone level being observed in industrially developed and highly populated regions of the world. In these regions, main anthropogenic sources of carbon monoxide (CO), methane (CH4) and volatile organic compounds (VOCs) are concentrated. The oxidation of these compounds, when interacting with hydroxyl and nitrogen oxides at rather high temperature and sunlight, leads to ozone formation. CO and CH4 are slowly oxidized in the atmosphere and cause an increase in global and regional background ozone. However, the oxidation of some VOCs occurs during daylight hours and is accompanied by an increase in ozone concentration near VOCs sources, particularly in urban and industrial areas. The contribution of biogenic VOCs to ozone generation is estimated to be from 40 to 70% of the total contribution of all chemical ozone precursors in the troposphere [1], with isoprene playing the main role in ozone formation [2]. The impact of aromatic hydrocarbons to ozone formation is reported to be about 40% of the total ozone generation from the oxidation of anthropogenic VOCs [3]. In this study, the results of VOCs measurements (isoprene, benzene, toluene, phenol, styrene, xylene and propilbenzene) by proton mass spectrometry in different regions of Russia along the Trans-Siberian railway from Moscow to Vladivostok from TROICA-12 campaign on a mobile laboratory in summer 2008 are analyzed. It is shown that the TROICA-12 measurements were carried out mostly in moderately polluted (2≤NOx<20 ppb) environment ( 78% of measurements) with the remaining part of the measurements divided between weakly polluted (NOx≤2 ppb) and highly polluted (NOx>20 ppb) conditions ( 20 and 2% of measurements, correspondingly). The lower troposphere chemical regime in the campaign is found to be mainly NOx sensitive, both in rural and urban environments, with typical morning NMHC/NOx ratios being well above 20. Hence, ozone production rates are expected to be controlled by regional NOx emissions and their complex interplay with both natural and anthropogenic sources of VOCs. The quantitative contribution of aromatic VOCs to ozone formation in urban areas and in Russian regions along the railway is estimated. The greatest impact of aromatic VOCs to ozone formation (up to 7.5 ppb of O3) is obtained in the large cities along the Trans-Siberian Railway, with the highest concentrations of aromatic VOCs (1-1.7 ppb) and nitrogen oxides (> 20 ppb) being observed. The results show a significant contribution of anthropogenic emissions of VOCs to the photochemical ozone generation (30-50%) in the large cities along the Trans-Siberian railway in hot and dry weather conditions against natural isoprene emissions determining the regional balance of ground-level ozone in summer. This study was supported by the Russian Science Foundation (grant no. 14-47-00049) and by the Russian Foundation for Basic Research (grant no. 16-35-00158). References: 1. Xie, X., Shao, M., Liu, Y., Lu, S., Chang, C. C., and Chen, Z. M. // Atmos. Environ., 2008, 42, pp. 6000-6010. 2. Guenther, A., Geron, C., Pierce, T., Lamb, B., Harley, P., Fall, R. // Atmospheric Environment, 2000, 34, pp. 2205-2230. 3. Dreyfus, G. B., Schade G. W., Goldstein A. H. // J. Geophys. Res., 2002, 107(D19): 4365, doi:10.1029/2001JD001490.

Optimization of the GSFC TROPOZ DIAL retrieval using synthetic lidar returns and ozonesondes - Part 1: Algorithm validation

NASA Astrophysics Data System (ADS)

Sullivan, J. T.; McGee, T. J.; Leblanc, T.; Sumnicht, G. K.; Twigg, L. W.

2015-10-01

The main purpose of the NASA Goddard Space Flight Center TROPospheric OZone DIfferential Absorption Lidar (GSFC TROPOZ DIAL) is to measure the vertical distribution of tropospheric ozone for science investigations. Because of the important health and climate impacts of tropospheric ozone, it is imperative to quantify background photochemical ozone concentrations and ozone layers aloft, especially during air quality episodes. For these reasons, this paper addresses the necessary procedures to validate the TROPOZ retrieval algorithm and confirm that it is properly representing ozone concentrations. This paper is focused on ensuring the TROPOZ algorithm is properly quantifying ozone concentrations, and a following paper will focus on a systematic uncertainty analysis. This methodology begins by simulating synthetic lidar returns from actual TROPOZ lidar return signals in combination with a known ozone profile. From these synthetic signals, it is possible to explicitly determine retrieval algorithm biases from the known profile. This was then systematically performed to identify any areas that need refinement for a new operational version of the TROPOZ retrieval algorithm. One immediate outcome of this exercise was that a bin registration error in the correction for detector saturation within the original retrieval was discovered and was subsequently corrected for. Another noticeable outcome was that the vertical smoothing in the retrieval algorithm was upgraded from a constant vertical resolution to a variable vertical resolution to yield a statistical uncertainty of <10 %. This new and optimized vertical-resolution scheme retains the ability to resolve fluctuations in the known ozone profile, but it now allows near-field signals to be more appropriately smoothed. With these revisions to the previous TROPOZ retrieval, the optimized TROPOZ retrieval algorithm (TROPOZopt) has been effective in retrieving nearly 200 m lower to the surface. Also, as compared to the previous version of the retrieval, the TROPOZopt had an overall mean improvement of 3.5 %, and large improvements (upwards of 10-15 % as compared to the previous algorithm) were apparent between 4.5 and 9 km. Finally, to ensure the TROPOZopt retrieval algorithm is robust enough to handle actual lidar return signals, a comparison is shown between four nearby ozonesonde measurements. The ozonesondes are mostly within the TROPOZopt retrieval uncertainty bars, which implies that this exercise was quite successful.

The ozone depletion potentials on halocarbons: Their dependence of calculation assumptions

NASA Technical Reports Server (NTRS)

Karol, Igor L.; Kiselev, Andrey A.

1994-01-01

The concept of Ozone Depletion Potential (ODP) is widely used in the evaluation of numerous halocarbons and of their replacement effects on ozone, but the methods, assumptions and conditions used in ODP calculations have not been analyzed adequately. In this paper a model study of effects on ozone of the instantaneous releases of various amounts of CH3CCl3 and of CHF2Cl (HCFC-22) for several compositions of the background atmosphere are presented, aimed at understanding connections of ODP values with the assumptions used in their calculations. To facilitate the ODP computation in numerous versions for the long time periods after their releases, the above rather short-lived gases and the one-dimensional radiative photochemical model of the global annually averaged atmospheric layer up to 50 km height are used. The variation of released gas global mass from 1 Mt to 1 Gt leads to ODP value increase with its stabilization close to the upper bound of this range in the contemporary atmosphere. The same variations are analyzed for conditions of the CFC-free atmosphere of 1960's and for the anthropogenically loaded atmosphere in the 21st century according to the known IPCC 'business as usual' scenario. Recommendations for proper ways of ODP calculations are proposed for practically important cases.

Variations of surface ozone at Ieodo Ocean Research Station in the East China Sea and the influence of Asian outflows

NASA Astrophysics Data System (ADS)

Han, J.; Shin, B.; Lee, M.; Hwang, G.; Kim, J.; Shim, J.; Lee, G.; Shim, C.

2015-11-01

Ieodo Ocean Research Station (IORS), a research tower (~ 40 m a.s.l.) for atmospheric and oceanographic observations, is located in the East China Sea (32.07° N, 125.10° E). The IORS is almost equidistant from South Korea, China, and Japan and, therefore, it is an ideal place to observe Asian outflows without local emission effects. The seasonal variation of ozone was distinct, with a minimum in August (37 ppbv) and two peaks in April and October (62 ppbv), and was largely affected by the seasonal wind pattern over east Asia. At IORS, six types of air masses were distinguished with different levels of O3 concentrations by the cluster analysis of backward trajectories. Marine air masses from the Pacific Ocean represent a relatively clean background air with a lowest ozone level of 32 ppbv, which was most frequently observed in summer (July-August). In spring (March-April) and winter (December-February), the influence of Chinese outflows was dominant with higher ozone concentrations of 62 and 49 ppbv, respectively. This study confirms that the influence of Chinese outflows was the main factor determining O3 levels at IORS and its extent was dependent on meteorological state, particularly at a long-term scale.

The Influence of the Several Very Large Solar Proton Events in Years 2000-2003 on the Neutral Middle Atmosphere

NASA Technical Reports Server (NTRS)

Jackman, Charles H.; Deland, Matthew T.; Labow, Gordon J.; Fleming, Eric L.; Weisenstein, Debra K.; Ko, Malcolm K. W.; Sinnhuber, Miriam; Anderson, John; Russell, James M.

2004-01-01

Solar proton events (SPEs) are known to have caused changes in constituents in the Earth's polar neutral middle atmosphere. The past four years, 2000-2003, have been replete with SPEs and huge fluxes of high energy protons occurred in July and November 2000, September and November 2001, and October 2003. The highly energetic protons produce ionizations, excitations, dissociations, and dissociative ionizations of the background constituents, which lead to the production of HOx (H, OH, HO2) and NOy (N, NO, NO2, NO3, N2O5, HNO3, HO2NO2, ClONO2, BrONO2). The HOx increases lead to short-lived ozone decreases in the polar mesosphere and upper stratosphere due to the short lifetimes of the HOx constituents. Large mesospheric ozone depletions (>70%) due to the HOx enhancements were observed and modeled as a result of the very large July 2000 SPE. The NOy increases lead to long-lived stratospheric ozone changes because of the long lifetime of the NOy family in this region. Polar total ozone depletions >1% were simulated in both hemispheres for extended periods of time (several months) as a result of the NOy enhancements due to the very large SPEs.

77 FR 61379 - Performance Review Board Membership

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2012-10-09

... DEPARTMENT OF COMMERCE Performance Review Board Membership AGENCY: Economics and Statistics... eligible to serve on the Performance Review Board (PRB) in accordance with the Economics and Statistics..., Associate Under Secretary for Management Chair, Performance Review Board. [FR Doc. 2012-24510 Filed 10-5-12...

EVALUATION OF PERMEABLE REACTIVE BARRIER PERFORMANCE: A TRI-AGENCY INITIATIVE

EPA Science Inventory

The permeable reactive barrier (PRB) technology represents a passive option for long-term treatment of ground-water contamination. PRBs are a potentially more cost-effective treatment option for a variety of dissolved contaminants, such as certain types of chlorinated solvents, ...

75 FR 63147 - Performance Review Board (PRB)

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2010-10-14

.... Patricia M. Richter, Chief Administrative Officer, United States Patent and Trademark Office. Robert L..., Commissioner for Trademarks, United States Patent and Trademark Office. Anthony P. Scardino, Chief Financial Officer, United States Patent and Trademark Office. John B. Owens II, Chief Information Officer, United...

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2012-11-06

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LONG-TERM PERFORMANCE MONITORING OF A PERMEABLE REACTIVE BARRIER TO REMEDIATE CONTAMINATED GROUND WATER

EPA Science Inventory

Permeable reactive barriers (PRB's) are an emerging, alternative in-situ approach for remediating groundwater contamination that combine subsurface fluid flow management with a passive chemical treatment zone. The few pilot and commercial installations which have been implemented...

76 FR 80902 - Senior Executive Service; Performance Review Board; Members

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2011-12-27

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75 FR 56999 - Senior Executive Service Performance Review Board

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2010-09-17

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75 FR 62509 - Senior Executive Service Performance Review Board

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2010-10-12

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