Investigation on Dynamic Calibration for an Optical-Fiber Solids Concentration Probe in Gas-Solid Two-Phase Flows

PubMed Central

Xu, Guiling; Liang, Cai; Chen, Xiaoping; Liu, Daoyin; Xu, Pan; Shen, Liu; Zhao, Changsui

2013-01-01

This paper presents a review and analysis of the research that has been carried out on dynamic calibration for optical-fiber solids concentration probes. An introduction to the optical-fiber solids concentration probe was given. Different calibration methods of optical-fiber solids concentration probes reported in the literature were reviewed. In addition, a reflection-type optical-fiber solids concentration probe was uniquely calibrated at nearly full range of the solids concentration from 0 to packed bed concentration. The effects of particle properties (particle size, sphericity and color) on the calibration results were comprehensively investigated. The results show that the output voltage has a tendency to increase with the decreasing particle size, and the effect of particle color on calibration result is more predominant than that of sphericity. PMID:23867745

A modified impulse-response representation of the global near-surface air temperature and atmospheric concentration response to carbon dioxide emissions

NASA Astrophysics Data System (ADS)

Millar, Richard J.; Nicholls, Zebedee R.; Friedlingstein, Pierre; Allen, Myles R.

2017-06-01

Projections of the response to anthropogenic emission scenarios, evaluation of some greenhouse gas metrics, and estimates of the social cost of carbon often require a simple model that links emissions of carbon dioxide (CO2) to atmospheric concentrations and global temperature changes. An essential requirement of such a model is to reproduce typical global surface temperature and atmospheric CO2 responses displayed by more complex Earth system models (ESMs) under a range of emission scenarios, as well as an ability to sample the range of ESM response in a transparent, accessible and reproducible form. Here we adapt the simple model of the Intergovernmental Panel on Climate Change 5th Assessment Report (IPCC AR5) to explicitly represent the state dependence of the CO2 airborne fraction. Our adapted model (FAIR) reproduces the range of behaviour shown in full and intermediate complexity ESMs under several idealised carbon pulse and exponential concentration increase experiments. We find that the inclusion of a linear increase in 100-year integrated airborne fraction with cumulative carbon uptake and global temperature change substantially improves the representation of the response of the climate system to CO2 on a range of timescales and under a range of experimental designs.

Impact of compost process conditions on organic micro pollutant degradation during full scale composting.

PubMed

Sadef, Yumna; Poulsen, Tjalfe Gorm; Bester, Kai

2015-06-01

Knowledge about the effects of oxygen concentration, nutrient availability and moisture content on removal of organic micro-pollutants during aerobic composting is at present very limited. Impact of oxygen concentration, readily available nitrogen content (NH4(+), NO3(-)), and moisture content on biological transformation of 15 key organic micro-pollutants during composting, was therefore investigated using bench-scale degradation experiments based on non-sterile compost samples, collected at full-scale composting facilities. In addition, the adequacy of bench-scale composting experiments for representing full-scale composting conditions, was investigated using micro-pollutant concentration measurements from both bench- and full-scale composting experiments. Results showed that lack of oxygen generally prevented transformation of organic micro-pollutants. Increasing readily available nitrogen content from about 50 mg N per 100 g compost to about 140 mg N per 100 g compost actually reduced micro-pollutant transformation, while changes in compost moisture content from 50% to 20% by weight, only had minor influence on micro-pollutant transformation. First-order micro-pollutant degradation rates for 13 organic micro-pollutants were calculated using data from both full- and bench-scale experiments. First-order degradation coefficients for both types of experiments were similar and ranged from 0.02 to 0.03 d(-1) on average, indicating that if a proper sampling strategy is employed, bench-scale experiments can be used to represent full-scale composting conditions. Copyright © 2015 Elsevier Ltd. All rights reserved.

Little Blue Prehistory: Archaeological Investigations at Blue Springs and Longview Lakes, Jackson County, Missouri. Volume 2

DTIC Science & Technology

1989-01-01

Kisker occupation ranges from A.D. 1000-1200. The economy was principally centered on the growing of domesticated cultigens, gathering of wild plants, and...m units. Within the center of the lithic concentration was a small cohesive distribution of chipped-stone consisting of 13 flakes and one core of...B.C. (UGA-2404) are associated with the remnants of a full range of domestic activities. According to the number and variety of artifacts, the Traff

Communication—Quantitative Voltammetric Analysis of High Concentration Actinides in Molten Salts

DOE PAGES

Hoyt, Nathaniel C.; Willit, James L.; Williamson, Mark A.

2017-01-18

Previous electroanalytical studies have shown that cyclic voltammetry can provide accurate quantitative measurements of actinide concentrations at low weight loadings in molten salts. However, above 2 wt%, the techniques were found to underpredict the concentrations of the reactant species. Here this work will demonstrate that much of the discrepancy is caused by uncompensated resistance and cylindrical diffusion. An improved electroanalytical approach has therefore been developed using the results of digital simulations to take these effects into account. This approach allows for accurate electroanalytical predictions across the full range of weight loadings expected to be encountered in operational nuclear fuel processingmore » equipment.« less

Communication—Quantitative Voltammetric Analysis of High Concentration Actinides in Molten Salts

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

Hoyt, Nathaniel C.; Willit, James L.; Williamson, Mark A.

Previous electroanalytical studies have shown that cyclic voltammetry can provide accurate quantitative measurements of actinide concentrations at low weight loadings in molten salts. However, above 2 wt%, the techniques were found to underpredict the concentrations of the reactant species. Here this work will demonstrate that much of the discrepancy is caused by uncompensated resistance and cylindrical diffusion. An improved electroanalytical approach has therefore been developed using the results of digital simulations to take these effects into account. This approach allows for accurate electroanalytical predictions across the full range of weight loadings expected to be encountered in operational nuclear fuel processingmore » equipment.« less

Full Range of Motion Induces Greater Muscle Damage Than Partial Range of Motion in Elbow Flexion Exercise With Free Weights.

PubMed

Baroni, Bruno M; Pompermayer, Marcelo G; Cini, Anelize; Peruzzolo, Amanda S; Radaelli, Régis; Brusco, Clarissa M; Pinto, Ronei S

2017-08-01

Baroni, BM, Pompermayer, MG, Cini, A, Peruzzolo, AS, Radaelli, R, Brusco, CM, and Pinto, RS. Full range of motion induces greater muscle damage than partial range of motion in elbow flexion exercise with free weights. J Strength Cond Res 31(8): 2223-2230, 2017-Load and range of motion (ROM) applied in resistance training (RT) affect the muscle damage magnitude and the recovery time-course. Because exercises performed with partial ROM allow a higher load compared with those with full ROM, this study investigated the acute effect of a traditional RT exercise using full ROM or partial ROM on muscle damage markers. Fourteen healthy men performed 4 sets of 10 concentric-eccentric repetitions of unilateral elbow flexion on the Scott bench. Arms were randomly assigned to partial-ROM (50-100°) and full-ROM (0-130°) conditions, and load was determined as 80% of 1 repetition maximum (1RM) in the full- and partial-ROM tests. Muscle damage markers were assessed preexercise, immediately, and 24, 48, and 72 hours after exercise. Primary outcomes were peak torque, muscle soreness during palpation and elbow extension, arm circumference, and joint ROM. The load lifted in the partial-ROM condition (1RM = 19.1 ± 3.0 kg) was 40 ± 18% higher compared with the full-ROM condition (1RM = 13.7 ± 2.2 kg). Seventy-two hours after exercise, the full-ROM condition led to significant higher soreness sensation during elbow extension (1.3-4.1 cm vs. 1.0-1.9 cm) and smaller ROM values (97.5-106.1° vs. 103.6-115.7°). Peak torque, soreness from palpation, and arm circumference were statistically similar between conditions, although mean values in all time points of these outcomes have suggested more expressive muscle damage for the full-ROM condition. In conclusion, elbow flexion exercise with full ROM seems to induce greater muscle damage than partial-ROM exercises, even though higher absolute load was achieved with partial ROM.

Simultaneous saccharification and ethanol fermentation of oxalic acid pretreated corncob assessed with response surface methodology

Treesearch

Jae-Won Lee; Rita C.L.B. Rodrigues; Thomas W. Jeffries

2009-01-01

Response surface methodology was used to evaluate optimal time, temperature and oxalic acid concentration for simultaneous saccharification and fermentation (SSF) of corncob particles by Pichia stipitis CBS 6054. Fifteen different conditions for pretreatment were examined in a 23 full factorial design with six axial points. Temperatures ranged from 132 to 180º...

Experimental investigation of the stability boundary for double-diffusive finger convection in a Hele-Shaw cell

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

Cooper, Clay A.; Glass, Robert J.; Tyler, Scott W.

OAK - B135 We apply high resolution, full field light transmission techniques to study the onset and development of convection in simulated porous media (Hele-Shaw cells) and fractures. The light transmission technique allows quantitative measurement of the solute concentration fields in time thus allowing direct measurements of the mass flux of components. Experiments are first designed to test theoretical stability relations as a function of the solute concentrations, solute diffusivities and the medium's permeability. Structural evolution and convective transport as a function of dimensionless control parameters is then determined across the full range of parameter space. We also consider themore » application of lattice gas automata techniques to numerically model the onset and development of convection. (Gary Drew notified on 3/25/03 of copyrighted Material)« less

Scattering Solar Thermal Concentrators

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

Giebink, Noel C.

2015-01-31

This program set out to explore a scattering-based approach to concentrate sunlight with the aim of improving collector field reliability and of eliminating wind loading and gross mechanical movement through the use of a stationary collection optic. The approach is based on scattering sunlight from the focal point of a fixed collection optic into the confined modes of a sliding planar waveguide, where it is transported to stationary tubular heat transfer elements located at the edges. Optical design for the first stage of solar concentration, which entails focusing sunlight within a plane over a wide range of incidence angles (>120more » degree full field of view) at fixed tilt, led to the development of a new, folded-path collection optic that dramatically out-performs the current state-of-the-art in scattering concentration. Rigorous optical simulation and experimental testing of this collection optic have validated its performance. In the course of this work, we also identified an opportunity for concentrating photovoltaics involving the use of high efficiency microcells made in collaboration with partners at the University of Illinois. This opportunity exploited the same collection optic design as used for the scattering solar thermal concentrator and was therefore pursued in parallel. This system was experimentally demonstrated to achieve >200x optical concentration with >70% optical efficiency over a full day by tracking with <1 cm of lateral movement at fixed latitude tilt. The entire scattering concentrator waveguide optical system has been simulated, tested, and assembled at small scale to verify ray tracing models. These models were subsequently used to predict the full system optical performance at larger, deployment scale ranging up to >1 meter aperture width. Simulations at an aperture widths less than approximately 0.5 m with geometric gains ~100x predict an overall optical efficiency in the range 60-70% for angles up to 50 degrees from normal. However, the concentrator optical efficiency was found to decrease significantly with increasing aperture width beyond 0.5 m due to parasitic waveguide out-coupling loss and low-level absorption that become dominant at larger scale. A heat transfer model was subsequently implemented to predict collector fluid heat gain and outlet temperature as a function of flow rate using the optical model as a flux input. It was found that the aperture width size limitation imposed by the optical efficiency characteristics of the waveguide limits the absolute optical power delivered to the heat transfer element per unit length. As compared to state-of-the-art parabolic trough CPV system aperture widths approaching 5 m, this limitation leads to an approximate factor of order of magnitude increase in heat transfer tube length to achieve the same heat transfer fluid outlet temperature. The conclusion of this work is that scattering solar thermal concentration cannot be implemented at the scale and efficiency required to compete with the performance of current parabolic trough CSP systems. Applied within the alternate context of CPV, however, the results of this work have likely opened up a transformative new path that enables quasi-static, high efficiency CPV to be implemented on rooftops in the form factor of traditional fixed-panel photovoltaics.« less

Electrical Characterization of Glycerin: Water Mixtures: Implications for Use as a Coupling Medium in Microwave Tomography

PubMed Central

Meaney, Paul M.; Fox, Colleen J.; Geimer, Shireen D.; Paulsen, Keith D.

2016-01-01

We examine the broadband behavior of complex electrical properties of glycerin and water mixtures over the frequency range of 0.1 – 25.0 GHz, especially as they relate to using these liquids as coupling media for microwave tomographic imaging. Their combination is unique in that they are mutually miscible over the full range of concentrations which allows them to be tailored to dielectric property matching for biological tissues. While the resultant mixture properties are partially driven by differences in the inherent low frequency permittivity of each constituent, relaxation frequency shifts play a disproportionately larger role in increasing the permittivity dispersion while also dramatically increasing the effective conductivity over the frequency range of 1 to 3 GHz. For the full range of mixture ratios, the relaxation frequency shifts from 17.5 GHz for 0% glycerin to less than 0.1 GHz for 100% glycerin. Of particular interest is the fact that the conductivity stays above 1.0 S/m over the 1–3 GHz range for glycerin mixture ratios (70–90% glycerin) we use for microwave breast tomography. The high level of attenuation is critical for suppressing unwanted multipath signals. This paper presents a full characterization of these liquids along with a discussion of their benefits and limitations in the context of microwave tomography. PMID:28507391

Contaminant profiles in Southeast Asian immigrants consuming fish from polluted waters in northeastern Wisconsin

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

Schantz, Susan L., E-mail: schantz@illinois.edu; Gardiner, Joseph C.; Aguiar, Andrea

2010-01-15

Recent immigrants to the USA from Southeast Asia may be at higher risk of exposure to fish-borne contaminants including polychlorinated biphenyls (PCBs), p, p'-dichlorodiphenyldichloroethene (DDE) and methylmercury (MeHg) because of their propensity to engage in subsistence fishing. Exposure to contaminants was assessed in men and women of Hmong descent living in Green Bay, Wisconsin, where the Fox River and lower Green Bay are contaminated with PCBs, and to a lesser extent with mercury. Serum samples from 142 people were analyzed for PCBs and p,p'-DDE by capillary column gas chromatography with electron capture detection (ECD). Whole blood was analyzed for totalmore » mercury by cold vapor atomic absorption spectrometry and atomic fluorescence spectroscopy. Lipid-adjusted total PCB concentrations ranged from 8.7 to 3,091 ng/g (full range of the data), with a geometric mean of 183.6 ng/g (estimated after eliminating one outlier). DDE ranged from 0.3 to 7,083 (full range of the data) with a geometric mean of 449.8 ng/g (estimated after eliminating two outliers). Men had higher PCB and DDE concentrations than women. Serum PCB concentrations were significantly correlated with fish consumption (r=0.43, p<0.0001), whereas DDE concentrations were not (r=0.09,p=0.29). Instead, serum DDE was strongly associated with the number of years spent in a Thai refugee camp before immigrating to the USA (r=0.60;p<0.0001). PCB congeners 138, 153, 118 and 180 accounted for a smaller percentage of the total PCBs than has been reported in other fish-eating populations, and several lightly chlorinated congeners were present in relatively large amounts. Mercury exposure was low in this population. In conclusion, Hmong immigrants in northeastern Wisconsin are at risk of elevated PCB exposure from consumption of locally caught fish. The pattern of exposure is somewhat different than patterns in other fish-eating populations, possibly due to use of Aroclor 1242 by the paper industry in this region.« less

Hydrogeologic and water-quality characteristics of the Red River-Winnipeg aquifer northwestern Minnesota

USGS Publications Warehouse

Ruhl, J.F.; Adolphson, D.G.

1986-01-01

Ground water generally flows eastward through the aquifer from North Dakota and discharges upward to wells and to overlying deposits. Yields of wells open to the full thickness of the aquifer range from 100 t 250 gallons per minute. The water is unsuitable for most uses because of the high mineral content. Dissolved-solids concentrations range from about 3,000 milligrams per liter in the eastern part of the aquifer to about 60,000 milligrams per liter in the northwestern corner of Minnesota.

Reduced expression of dermcidin, a peptide active against propionibacterium acnes, in sweat of patients with acne vulgaris.

PubMed

Nakano, Toshiaki; Yoshino, Takashi; Fujimura, Takao; Arai, Satoru; Mukuno, Akira; Sato, Naoya; Katsuoka, Kensei

2015-09-01

Dermcidin (DCD), an antimicrobial peptide with a broad spectrum of activity against bacteria such as Propionibacterum acnes, is expressed constitutively in sweat in the absence of stimulation due to injury or inflammation. The aim of this study was to determine the relationship between DCD expression and acne vulgaris associated with P. acnes. The antimicrobial activity of recombinant full-length DCD (50 μg/ml) was 97% against Escherichia coli and 100% against Staphylococcus aureus. Antimicrobial activity against P. acnes ranged from 68% at 50 μg/ml DCD to 83% at 270 μg/ml DCD. DCD concentration in sweat from patients with acne vulgaris (median 9.8 μg/ml, range 6.9-95.3 μg/ml) was significantly lower than in healthy subjects (median 136.7 μg/ml, range 45.4-201.6 μg/ml) (p = 0.001). DCD demonstrated concentration-dependent, but partial, microbicidal activity against P. acnes. These results suggest that reduced DCD concentration in sweat in patients with inflammatory acne may permit proliferation of P. acnes in pilosebaceous units, resulting in progression of inflammatory acne.

Lightweight Fiber Optic Gas Sensor for Monitoring Regenerative Food Production

NASA Technical Reports Server (NTRS)

Schmidlin, Edward; Goswami, Kisholoy

1995-01-01

In this final report, Physical Optics Corporation (POC) describes its development of sensors for oxygen, carbon dioxide, and relative humidity. POC has constructed a phase fluorometer that can detect oxygen over the full concentration range from 0 percent to 100 percent. Phase-based measurements offer distinct advantages, such as immunity to source fluctuation, photobleaching, and leaching. All optics, optoelectronics, power supply, and the printed circuit board are included in a single box; the only external connections to the fluorometer are the optical fiber sensor and a power cord. The indicator-based carbon dioxide sensor is also suitable for short-term and discrete measurements over the concentration range from 0 percent to 100 percent. The optical fiber-based humidity sensor contains a porous core for direct interaction of the light beam with water vapor within fiber pores; the detection range for the humidity sensor is 10 percent to 100 percent, and response time is under five minutes. POC is currently pursuing the commercialization of these oxygen and carbon dioxide sensors for environmental applications.

Heavy metal content and element analysis of infant formula and milk powder samples purchased on the Tanzanian market: International branded versus black market products.

PubMed

Sager, M; McCulloch, C R; Schoder, D

2018-07-30

Milk powder is a food for malnourished African children and for healthy infants of women with HIV/AIDS. High demand and low purchasing power has resulted in a huge informal, black market in Sub-Saharan Africa. Forty-three milk powder batches were analyzed for 43 chemical elements using ICP-MS One sample (2.3%) was contaminated at a lead concentration of 240 µg/kg dry weight exceeding the European threshold (130 µg/kg dry weight). Macroelement contents revealed a trend decreasing in concentration through skimmed, full cream products to infant formulae. Concentration ranges by dry weight differed in respect of uncertainty intervals of  ±10%. Median Ca, K and P concentrations declined from 11.14 g/kg to 3.21 g/kg, 14.11 g/kg to 4.95 g/kg and 9.12 g/kg to 2.75 g/kg dry mass, respectively. Milk powder samples obtained from the Tanzanian black market were comparable in respect of nutritional and chemical content to international branded full cream products. Copyright © 2018 Elsevier Ltd. All rights reserved.

The role of long-range transport and domestic emissions in determining atmospheric secondary inorganic particle concentrations across the UK

NASA Astrophysics Data System (ADS)

Vieno, M.; Heal, M. R.; Hallsworth, S.; Famulari, D.; Doherty, R. M.; Dore, A. J.; Tang, Y. S.; Braban, C. F.; Leaver, D.; Sutton, M. A.; Reis, S.

2013-12-01

Surface concentrations of secondary inorganic particle components over the UK have been analysed for 2001-2010 using the EMEP4UK regional atmospheric chemistry transport model. In early 2003 an episode of substantially elevated surface concentrations of ammonium nitrate was measured across the UK by the AGANET network. The EMEP4UK model was able accurately to represent both the long-term decadal surface concentrations and the episode in 2003. The latter was identified as consisting of three separate episodes, each of less than 1 month duration, in February, March and April. The primary cause of the elevated nitrate levels across the UK was meteorological, a persistent high pressure system, but whose varying location impacted the relative importance of transboundary vs. domestic emissions. Whilst long-range transport dominated the elevated nitrate in February, in contrast it was domestic emissions that mainly contributed to the March episode, and for the April episode both domestic emissions and long-range transport contributed. A prolonged episode such as the one in early 2003 can have substantial impact on annual average concentrations. The episode led to annual concentration differences at the regional scale of similar magnitude to those driven by long-term changes in precursor emissions over the full decade investigated here. The results demonstrate that a substantial part of the UK, particularly the south and south-east, may be close to or actually exceeding annual mean limit values because of import of inorganic aerosol components from continental Europe under specific conditions. The results reinforce the importance of employing multiple year simulations in the assessment of emissions reduction scenarios on PM concentrations and the need for international agreements to address the transboundary component of air pollution.

Pressurized liquid extraction using water/isopropanol coupled with solid-phase extraction cleanup for semivolatile organic compounds, polycyclic aromatic hydrocarbons (PAH), and alkylated PAH homolog groups in sediment

USGS Publications Warehouse

Burkhardt, M.R.; Zaugg, S.D.; Burbank, T.L.; Olson, M.C.; Iverson, J.L.

2005-01-01

Polycyclic aromatic hydrocarbons (PAH) are recognized as environmentally relevant for their potential adverse effects on human and ecosystem health. This paper describes a method to determine the distribution of PAH and alkylated homolog groups in sediment samples. Pressurized liquid extraction (PLE), coupled with solid-phase extraction (SPE) cleanup, was developed to decrease sample preparation time, to reduce solvent consumption, and to minimize background interferences for full-scan GC-MS analysis. Recoveries from spiked Ottawa sand, environmental stream sediment, and commercially available topsoil, fortified at 1.5-15 ??g per compound, averaged 94.6 ?? 7.8%, 90.7 ?? 5.8% and 92.8 ?? 12.8%, respectively. Initial method detection limits for single-component compounds ranged from 20 to 302 ??g/kg, based on 25 g samples. Results from 28 environmental sediment samples, excluding homologs, show 35 of 41 compounds (85.4%) were detected in at least one sample with concentrations ranging from 20 to 100,000 ??g/kg. The most frequently detected compound, 2,6-dimethylnaphthalene, was detected in 23 of the 28 (82%) environmental samples with a concentration ranging from 15 to 907 ??g/kg. The results from the 28 environmental sediment samples for the homolog series showed that 27 of 28 (96%) samples had at least one homolog series present at concentrations ranging from 20 to 89,000 ??g/kg. The most frequently detected homolog series, C2-alkylated naphthalene, was detected in 26 of the 28 (93%) environmental samples with a concentration ranging from 25 to 3900 ??g/kg. Results for a standard reference material using dichloromethane Soxhlet-based extraction also are compared. ?? 2005 Elsevier B.V. All rights reserved.

Potency of a tau fibrillization inhibitor is influenced by its aggregation state

PubMed Central

Congdon, Erin E.; Necula, Mihaela; Blackstone, Robert D.; Kuret, Jeff

2007-01-01

Tau fibrillization is a potential therapeutic target for Alzheimer’s and other neurodegenerative diseases. Several small molecule inhibitors of tau aggregation have been developed for this purpose. One of them, 3,3′-bis(β-hydroxyethyl)-9-ethyl-5,5′-dimethoxythiacarbocyanine iodide (N744), is a cationic thiacarbocyanine dye that inhibits recombinant tau filament formation when present at submicromolar concentrations. To prepare dosing regimens for testing N744 activity in biological models, its full concentration-effect relationship in the range 0.01 – 60 μM was examined in vitro by electron microscopy and laser light scattering methods. Results revealed that N744 concentration dependence was biphasic, with fibrillization inhibitory activity appearing at submicromolar concentration, but with relief of inhibition and increases in fibrillization apparent above 10 μM. Therefore, fibrillization was inhibited ≥50% only over a narrow concentration range, which was further reduced by filament stabilizing modifications such as tau pseudophosphorylation. N744 inhibitory activity also was paralleled by changes in its aggregation state, with dimer predominating at inhibitory concentrations and large dye aggregates appearing at high concentrations. Ligand dimerization was promoted by the presence of tau protein, which lowered the equilibrium dissociation constant for dimerization more than an order of magnitude relative to controls. The results suggest that ligand aggregation may play an important role in both inhibitory and disinhibitory phases of the concentration-effect curve, and may lead to complex dose response relationships in model systems. PMID:17559794

Ecotoxicity of diethylene glycol and risk assessment for marine environment.

PubMed

Manfra, L; Tornambè, A; Savorelli, F; Rotini, A; Canepa, S; Mannozzi, M; Cicero, A M

2015-03-02

Diethylene glycol (DEG) is a chemical compound used during offshore oil activities to prevent hydrate formation, and it may be released into the sea. A full ecotoxicological characterization is required according to European and Italian regulations for chemical substances. We have evaluated long-term toxic effects of DEG on indicator species of the marine environment as algae (Phaeodactylum tricornutum), crustaceans (Artemia franciscana), molluscs (Tapes philippinarum) and fish (Dicentrarchus labrax). A range of no observed effect concentrations (365-25,000 mg/L) has been identified. Based on the toxicity results and the ratio between predicted environmental concentration and predicted no-effect concentration, we have estimated the maximum allowable value of DEG in the marine environment. Copyright © 2014 Elsevier B.V. All rights reserved.

Using high-resolution phosphorus data to investigate mitigation measures in headwater river catchments

NASA Astrophysics Data System (ADS)

Campbell, J. M.; Jordan, P.; Arnscheidt, J.

2015-01-01

This study reports the use of high-resolution water quality monitoring to assess the influence of changes in land use management on total phosphorus (TP) transfers in two 5 km2 agricultural sub-catchments. Specifically, the work investigates the issue of agricultural soil P management and subsequent diffuse transfers at high river flows over a 5-year timescale. The work also investigates the phenomenon of low flow P pollution from septic tank systems (STSs) and mitigation efforts - a key concern for catchment management. Results showed an inconsistent response to soil P management over 5 years with one catchment showing a convergence to optimum P concentrations and the other an overall increase. Both catchments indicated an overall increase in P concentration in defined high flow ranges. Low flow P concentration showed little change or higher P concentrations in defined low flow ranges despite replacement of defective systems and this is possibly due to a number of confounding reasons including increased housing densities due to new-builds. The work indicates fractured responses to catchment management advice and mitigation and that the short to medium term may be an insufficient time to expect the full implementation of policies (here defined as convergence to optimum soil P concentration and mitigation of STSs) and also to gauge their effectiveness.

Using high-resolution phosphorus data to investigate mitigation measures in headwater river catchments

NASA Astrophysics Data System (ADS)

Campbell, J. M.; Jordan, P.; Arnscheidt, J.

2014-09-01

This study reports the use of high resolution water quality monitoring to assess the influence of changes in landuse management on total phosphorus (TP) transfers in two 5 km2 agricultural sub-catchments. Specifically, the work investigates the "wicked problem" of agricultural soil P management and subsequent diffuse transfers at high river flows over a five year timescale. The work also investigates the phenomenon of low flow P pollution from septic tank systems (STS) and mitigation efforts - here termed the "filthy issue" of rural catchment management. Results showed an inconsistent response to soil P management over five years with one catchment showing a convergence to optimum P concentrations and the other an overall increase. Both catchments indicated an overall increase in P concentration in defined high flow ranges. Low flow P concentration showed little change or higher P concentrations in defined low flow ranges despite replacement of defective systems and this is possibly due to a number of confounding reasons including increased housing densities due to new-builds. The work indicates fractured responses to catchment management advice and mitigation and that the short to medium term may be an insufficient time to expect the full implementation of policies (here defined as convergence to optimum soil P concentration and mitigation of STS) and also to gauge their effectiveness.

Determining concentrations of 2-bromoallyl alcohol and dibromopropene in ground water using quantitative methods

USGS Publications Warehouse

Panshin, Sandra Y.

1997-01-01

A method for determining levels of 2-bromoallyl alcohol and 2,3-dibromopropene from ground-water samples using liquid/liquid extraction followed by gas chromatography/mass spectrometry is described. Analytes were extracted from the water using three aliquots of dichloromethane. The aliquots were combined and reduced in volume by rotary evaporation followed by evaporation using a nitrogen stream. The extracts were analyzed by capillary-column gas chromatography/mass spectrometry in the full-scan mode. Estimated method detection limits were 30 nanograms per liter for 2-bromoallyl alcohol and 10 nanograms per liter for 2,3-dibromopropene. Recoveries were determined by spiking three matrices at two concentration levels (0.540 and 5.40 micrograms per liter for 2-bromoallyl alcohol; and 0.534 and 5.34micro-grams per liter for dibromopropene). For seven replicates of each matrix at the high concentration level, the mean percent recoveries ranged from 43.9 to 64.9 percent for 2-bromoallyl alcohol, and from 87.5 to 99.3 percent for dibromopropene. At the low concentration level, the mean percent recoveries ranged from 43.8 to 95.2 percent for 2-bromoallyl alcohol, and from 71.3 to 84.9 percent for dibromopropene.

Modification of PBDEs (BDE-15, BDE-47, BDE-85 and BDE-126) biological toxicity, bio-concentration, persistence and atmospheric long-range transport potential based on the pharmacophore modeling assistant with the full factor experimental design.

PubMed

Jiang, Long; Li, Yu

2016-04-15

In this study, the properties of AhR binding affinity, bio-concentration factor, half-life and vapor pressure were selected as the typical indicators of biological toxicity, bio-concentration, persistence and atmospheric long-range transport potential for polybrominated diphenyl ethers (PBDEs), respectively. A three-dimensional pharmacophore modeling assistant with a full factor experimental design for each property was used to reveal the significant pharmacophore features and the substituent effects to obtain reasonable modified schemes for the selected target PBDEs. Finally, the performances of the persistent organic pollutant (POP) properties, the synthesis feasibility and the fire resistance of the modified compounds were evaluated. The most influential pharmacophore feature for all POP properties was the hydrophobic group, especially the vinyl and propyl groups. Modified compounds with two additional hydrophobic groups exhibited a better regulatory performance. The average reduction in the proportions of the four POP properties for the modified compounds (except for 3-phenyl-BDE-15) was 70.60%, 52.44%, 47.04% and 70.88%. In addition, the energy and the C-Br bond dissociation enthalpy of the four typical PBDEs were higher than those of the modified compounds (except for 3-phenyl-BDE-15), indicating the synthesis feasibility and the lower energy barrier of the modified compounds to release Br free radicals to provide fire resistance. Copyright © 2015 Elsevier B.V. All rights reserved.

Gellan gum microspheres crosslinked with trivalent ion: effect of polymer and crosslinker concentrations on drug release and mucoadhesive properties.

PubMed

Boni, Fernanda Isadora; Prezotti, Fabíola Garavello; Cury, Beatriz Stringhetti Ferreira

2016-08-01

Gellan gum microspheres were obtained by ionotropic gelation technique, using the trivalent ion Al(3+). The percentage of entrapment efficiency ranged from 48.76 to 87.52% and 2(2) randomized full factorial design demonstrated that both the increase of polymer concentration and the decrease of crosslinker concentration presented a positive effect in the amount of encapsulated drug. Microspheres size and circularity ranged from 700.17 to 938.32 μm and from 0.641 to 0.796 μm, respectively. The increase of polymer concentration (1-2%) and crosslinker concentration (3-5%) led to the enlargement of particle size and circularity. However, the association of increased crosslinker concentration and reduced polymer content made the particles more irregular. In vitro and ex vivo tests evidenced the high mucoadhesiveness of microspheres. The high liquid uptake ability of the microspheres was demonstrated and the pH variation did not affect this parameter. Drug release was pH dependent, with low release rates in acid pH (42.40% and 44.93%) and a burst effect in phosphate buffer pH (7.4). The Weibull model had the best correlation with the drug release data, demonstrating that the release process was driven by a complex mechanism involving the erosion and swelling of the matrix or by non-Fickian diffusion.

Comprehensive mapping and characteristic regimes of aerosol effects on the formation and evolution of pyro-convective clouds

DOE PAGES

Chang, D.; Cheng, Y.; Reutter, P.; ...

2015-09-21

Here, a recent parcel model study (Reutter et al., 2009) showed three deterministic regimes of initial cloud droplet formation, characterized by different ratios of aerosol concentrations ( N CN) to updraft velocities. This analysis, however, did not reveal how these regimes evolve during the subsequent cloud development. To address this issue, we employed the Active Tracer High Resolution Atmospheric Model (ATHAM) with full microphysics and extended the model simulation from the cloud base to the entire column of a single pyro-convective mixed-phase cloud. A series of 2-D simulations (over 1000) were performed over a wide range of N CN andmore » dynamic conditions. The integrated concentration of hydrometeors over the full spatial and temporal scales was used to evaluate the aerosol and dynamic effects. The results show the following. (1) The three regimes for cloud condensation nuclei (CCN) activation in the parcel model (namely aerosol-limited, updraft-limited, and transitional regimes) still exist within our simulations, but net production of raindrops and frozen particles occurs mostly within the updraft-limited regime. (2) Generally, elevated aerosols enhance the formation of cloud droplets and frozen particles. The response of raindrops and precipitation to aerosols is more complex and can be either positive or negative as a function of aerosol concentrations. The most negative effect was found for values of N CN of ~ 1000 to 3000 cm –3. (3) The nonlinear properties of aerosol–cloud interactions challenge the conclusions drawn from limited case studies in terms of their representativeness, and ensemble studies over a wide range of aerosol concentrations and other influencing factors are strongly recommended for a more robust assessment of the aerosol effects.« less

Statistical-thermodynamic model for light scattering from eye lens protein mixtures

NASA Astrophysics Data System (ADS)

Bell, Michael M.; Ross, David S.; Bautista, Maurino P.; Shahmohamad, Hossein; Langner, Andreas; Hamilton, John F.; Lahnovych, Carrie N.; Thurston, George M.

2017-02-01

We model light-scattering cross sections of concentrated aqueous mixtures of the bovine eye lens proteins γB- and α-crystallin by adapting a statistical-thermodynamic model of mixtures of spheres with short-range attractions. The model reproduces measured static light scattering cross sections, or Rayleigh ratios, of γB-α mixtures from dilute concentrations where light scattering intensity depends on molecular weights and virial coefficients, to realistically high concentration protein mixtures like those of the lens. The model relates γB-γB and γB-α attraction strengths and the γB-α size ratio to the free energy curvatures that set light scattering efficiency in tandem with protein refractive index increments. The model includes (i) hard-sphere α-α interactions, which create short-range order and transparency at high protein concentrations, (ii) short-range attractive plus hard-core γ-γ interactions, which produce intense light scattering and liquid-liquid phase separation in aqueous γ-crystallin solutions, and (iii) short-range attractive plus hard-core γ-α interactions, which strongly influence highly non-additive light scattering and phase separation in concentrated γ-α mixtures. The model reveals a new lens transparency mechanism, that prominent equilibrium composition fluctuations can be perpendicular to the refractive index gradient. The model reproduces the concave-up dependence of the Rayleigh ratio on α/γ composition at high concentrations, its concave-down nature at intermediate concentrations, non-monotonic dependence of light scattering on γ-α attraction strength, and more intricate, temperature-dependent features. We analytically compute the mixed virial series for light scattering efficiency through third order for the sticky-sphere mixture, and find that the full model represents the available light scattering data at concentrations several times those where the second and third mixed virial contributions fail. The model indicates that increased γ-γ attraction can raise γ-α mixture light scattering far more than it does for solutions of γ-crystallin alone, and can produce marked turbidity tens of degrees celsius above liquid-liquid separation.

Relationship between environmental phthalate exposure and the intelligence of school-age children.

PubMed

Cho, Soo-Churl; Bhang, Soo-Young; Hong, Yun-Chul; Shin, Min-Sup; Kim, Boong-Nyun; Kim, Jae-Won; Yoo, Hee-Jung; Cho, In Hee; Kim, Hyo-Won

2010-07-01

Concern over phthalates has emerged because of their potential toxicity to humans. We investigated the relationship between the urinary concentrations of phthalate metabolites and children's intellectual functioning. This study enrolled 667 children at nine elementary schools in five South Korean cities. A cross-sectional examination of urine phthalate concentrations was performed, and scores on neuropsychological tests were obtained from both the children and their mothers. We measured mono-2-ethylhexyl phthalate (MEHP) and mono(2-ethyl-5-oxohexyl)phthalate (MEOHP), both metabolites of di(2-ethylhexyl)phthalate (DEHP), and mono-n-butyl phthalate (MBP), a metabolite of dibutyl phthalate (DBP), in urine samples. The geometric mean (ln) concentrations of MEHP, MEOHP, and MBP were 21.3 microg/L [geometric SD (GSD) = 2.2 microg/L; range, 0.5-445.4], 18.0 microg/L (GSD = 2.4; range, 0.07-291.1), and 48.9 microg/L (GSD = 2.2; range, 2.1-1645.5), respectively. After adjusting for demographic and developmental covariates, the Full Scale IQ and Verbal IQ scores were negatively associated with DEHP metabolites but not with DBP metabolites. We also found a significant negative relationship between the urine concentrations of the metabolites of DEHP and DBP and children's vocabulary subscores. After controlling for maternal IQ, a significant inverse relationship between DEHP metabolites and vocabulary subscale score remained. Among boys, we found a negative association between increasing MEHP phthalate concentrations and the sum of DEHP metabolite concentrations and Wechsler Intelligence Scale for Children vocabulary score; however, among girls, we found no significant association between these variables. Controlling for maternal IQ and other covariates, the results show an inverse relationship between phthalate metabolites and IQ scores; however, given the limitations in cross-sectional epidemiology, prospective studies are needed to fully explore these associations.

Multispectrum analysis of the oxygen A-band.

PubMed

Drouin, Brian J; Benner, D Chris; Brown, Linda R; Cich, Matthew J; Crawford, Timothy J; Devi, V Malathy; Guillaume, Alexander; Hodges, Joseph T; Mlawer, Eli J; Robichaud, David J; Oyafuso, Fabiano; Payne, Vivienne H; Sung, Keeyoon; Wishnow, Edward H; Yu, Shanshan

2017-01-01

Retrievals of atmospheric composition from near-infrared measurements require measurements of airmass to better than the desired precision of the composition. The oxygen bands are obvious choices to quantify airmass since the mixing ratio of oxygen is fixed over the full range of atmospheric conditions. The OCO-2 mission is currently retrieving carbon dioxide concentration using the oxygen A-band for airmass normalization. The 0.25% accuracy desired for the carbon dioxide concentration has pushed the required state-of-the-art for oxygen spectroscopy. To measure O 2 A-band cross-sections with such accuracy through the full range of atmospheric pressure requires a sophisticated line-shape model (Rautian or Speed-Dependent Voigt) with line mixing (LM) and collision induced absorption (CIA). Models of each of these phenomena exist, however, this work presents an integrated self-consistent model developed to ensure the best accuracy. It is also important to consider multiple sources of spectroscopic data for such a study in order to improve the dynamic range of the model and to minimize effects of instrumentation and associated systematic errors. The techniques of Fourier Transform Spectroscopy (FTS) and Cavity Ring-Down Spectroscopy (CRDS) allow complimentary information for such an analysis. We utilize multispectrum fitting software to generate a comprehensive new database with improved accuracy based on these datasets. The extensive information will be made available as a multi-dimensional cross-section (ABSCO) table and the parameterization will be offered for inclusion in the HITRANonline database.

Multispectrum analysis of the oxygen A-band

PubMed Central

Drouin, Brian J.; Benner, D. Chris; Brown, Linda R.; Cich, Matthew J.; Crawford, Timothy J.; Devi, V. Malathy; Guillaume, Alexander; Hodges, Joseph T.; Mlawer, Eli J.; Robichaud, David J.; Oyafuso, Fabiano; Payne, Vivienne H.; Sung, Keeyoon; Wishnow, Edward H.; Yu, Shanshan

2016-01-01

Retrievals of atmospheric composition from near-infrared measurements require measurements of airmass to better than the desired precision of the composition. The oxygen bands are obvious choices to quantify airmass since the mixing ratio of oxygen is fixed over the full range of atmospheric conditions. The OCO-2 mission is currently retrieving carbon dioxide concentration using the oxygen A-band for airmass normalization. The 0.25% accuracy desired for the carbon dioxide concentration has pushed the required state-of-the-art for oxygen spectroscopy. To measure O2 A-band cross-sections with such accuracy through the full range of atmospheric pressure requires a sophisticated line-shape model (Rautian or Speed-Dependent Voigt) with line mixing (LM) and collision induced absorption (CIA). Models of each of these phenomena exist, however, this work presents an integrated self-consistent model developed to ensure the best accuracy. It is also important to consider multiple sources of spectroscopic data for such a study in order to improve the dynamic range of the model and to minimize effects of instrumentation and associated systematic errors. The techniques of Fourier Transform Spectroscopy (FTS) and Cavity Ring-Down Spectroscopy (CRDS) allow complimentary information for such an analysis. We utilize multispectrum fitting software to generate a comprehensive new database with improved accuracy based on these datasets. The extensive information will be made available as a multi-dimensional cross-section (ABSCO) table and the parameterization will be offered for inclusion in the HITRANonline database. PMID:27840454

Multispectrum analysis of the oxygen A-band

DOE PAGES

Drouin, Brian J.; Benner, D. Chris; Brown, Linda R.; ...

2016-04-11

Retrievals of atmospheric composition from near-infrared measurements require measurements of airmass to better than the desired precision of the composition. The oxygen bands are obvious choices to quantify airmass since the mixing ratio of oxygen is fixed over the full range of atmospheric conditions. The OCO-2 mission is currently retrieving carbon dioxide concentration using the oxygen A-band for airmass normalization. The 0.25% accuracy desired for the carbon dioxide concentration has pushed the required state-of-the-art for oxygen spectroscopy. To measure O2 A-band cross-sections with such accuracy through the full range of atmospheric pressure requires a sophisticated line-shape model (Rautian or Speed-Dependentmore » Voigt) with line mixing (LM) and collision induced absorption (CIA). Models of each of these phenomena exist, however, this work presents an integrated self-consistent model developed to ensure the best accuracy. It is also important to consider multiple sources of spectroscopic data for such a study in order to improve the dynamic range of the model and to minimize effects of instrumentation and associated systematic errors. The techniques of Fourier Transform Spectroscopy (FTS) and Cavity Ring-Down Spectroscopy (CRDS) allow complimentary information for such an analysis. We utilize multispectrum fitting software to generate a comprehensive new database with improved accuracy based on these datasets. As a result, the extensive information will be made available as a multi-dimensional cross-section (ABSCO) table and the parameterization will be offered for inclusion in the HITRANonline database.« less

Multispectrum analysis of the oxygen A-band

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

Drouin, Brian J.; Benner, D. Chris; Brown, Linda R.

Retrievals of atmospheric composition from near-infrared measurements require measurements of airmass to better than the desired precision of the composition. The oxygen bands are obvious choices to quantify airmass since the mixing ratio of oxygen is fixed over the full range of atmospheric conditions. The OCO-2 mission is currently retrieving carbon dioxide concentration using the oxygen A-band for airmass normalization. The 0.25% accuracy desired for the carbon dioxide concentration has pushed the required state-of-the-art for oxygen spectroscopy. To measure O2 A-band cross-sections with such accuracy through the full range of atmospheric pressure requires a sophisticated line-shape model (Rautian or Speed-Dependentmore » Voigt) with line mixing (LM) and collision induced absorption (CIA). Models of each of these phenomena exist, however, this work presents an integrated self-consistent model developed to ensure the best accuracy. It is also important to consider multiple sources of spectroscopic data for such a study in order to improve the dynamic range of the model and to minimize effects of instrumentation and associated systematic errors. The techniques of Fourier Transform Spectroscopy (FTS) and Cavity Ring-Down Spectroscopy (CRDS) allow complimentary information for such an analysis. We utilize multispectrum fitting software to generate a comprehensive new database with improved accuracy based on these datasets. As a result, the extensive information will be made available as a multi-dimensional cross-section (ABSCO) table and the parameterization will be offered for inclusion in the HITRANonline database.« less

The relationship of blood- and urine-boron to boron exposure in borax-workers and usefulness of urine-boron as an exposure marker.

PubMed Central

Culver, B D; Shen, P T; Taylor, T H; Lee-Feldstein, A; Anton-Culver, H; Strong, P L

1994-01-01

Daily dietary-boron intake and on-the-job inspired boron were compared with blood- and urine-boron concentrations in workers engaged in packaging and shipping borax. Fourteen workers handling borax at jobs of low, medium, and high dust exposures were sampled throughout full shifts for 5 consecutive days each. Airborne borax concentrations ranged from means of 3.3 mg/m3 to 18 mg/m3, measured gravimetrically. End-of-shift mean blood-boron concentrations ranged from 0.11 to 0.26 microgram/g; end-of-shift mean urine concentrations ranged from 3.16 to 10.72 micrograms/mg creatinine. Creatinine measures were used to adjust for differences in urine-specific gravity such that 1 ml of urine contains approximately 1 mg creatinine. There was no progressive increase in end-of-shift blood- or urine-boron concentrations across the days of the week. Urine testing done at the end of the work shift gave a somewhat better estimate of borate exposure than did blood testing, was sampled more easily, and was analytically less difficult to perform. Personal air samplers of two types were used: one, the 37-mm closed-face, two-piece cassette to estimate total dust and the other, the Institute of Occupational Medicine (IOM) sampler to estimate inspirable particulate mass. Under the conditions of this study, the IOM air sampler more nearly estimated human exposure as measured by blood- and urine-boron levels than did the sampler that measured total dust.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7889874

Logarithmic sensing in Bacillus subtilis aerotaxis.

PubMed

Menolascina, Filippo; Rusconi, Roberto; Fernandez, Vicente I; Smriga, Steven; Aminzare, Zahra; Sontag, Eduardo D; Stocker, Roman

2017-01-01

Aerotaxis, the directed migration along oxygen gradients, allows many microorganisms to locate favorable oxygen concentrations. Despite oxygen's fundamental role for life, even key aspects of aerotaxis remain poorly understood. In Bacillus subtilis, for example, there is conflicting evidence of whether migration occurs to the maximal oxygen concentration available or to an optimal intermediate one, and how aerotaxis can be maintained over a broad range of conditions. Using precisely controlled oxygen gradients in a microfluidic device, spanning the full spectrum of conditions from quasi-anoxic to oxic (60 n mol/l-1 m mol/l), we resolved B. subtilis' 'oxygen preference conundrum' by demonstrating consistent migration towards maximum oxygen concentrations ('monotonic aerotaxis'). Surprisingly, the strength of aerotaxis was largely unchanged over three decades in oxygen concentration (131 n mol/l-196 μ mol/l). We discovered that in this range B. subtilis responds to the logarithm of the oxygen concentration gradient, a rescaling strategy called 'log-sensing' that affords organisms high sensitivity over a wide range of conditions. In these experiments, high-throughput single-cell imaging yielded the best signal-to-noise ratio of any microbial taxis study to date, enabling the robust identification of the first mathematical model for aerotaxis among a broad class of alternative models. The model passed the stringent test of predicting the transient aerotactic response despite being developed on steady-state data, and quantitatively captures both monotonic aerotaxis and log-sensing. Taken together, these results shed new light on the oxygen-seeking capabilities of B. subtilis and provide a blueprint for the quantitative investigation of the many other forms of microbial taxis.

The Effects of the Critical Ice Accretion on Airfoil and Wing Performance

NASA Technical Reports Server (NTRS)

Selig, Michael S.; Bragg, Michael B.; Saeed, Farooq

1998-01-01

In support of the NASA Lewis Modern Airfoils Ice Accretion Test Program, the University of Illinois at Urbana-Champaign provided expertise in airfoil design and aerodynamic analysis to determine the aerodynamic effect of ice accretion on modern airfoil sections. The effort has concentrated on establishing a design/testing methodology for "hybrid airfoils" or "sub-scale airfoils," that is, airfoils having a full-scale leading edge together with a specially designed and foreshortened aft section. The basic approach of using a full-scale leading edge with a foreshortened aft section was considered to a limited extent over 40 years ago. However, it was believed that the range of application of the method had not been fully exploited. Thus a systematic study was being undertaken to investigate and explore the range of application of the method so as to determine its overall potential.

In vivo measurements of cutaneous melanin across spatial scales: using multiphoton microscopy and spatial frequency domain spectroscopy.

PubMed

Saager, Rolf B; Balu, Mihaela; Crosignani, Viera; Sharif, Ata; Durkin, Anthony J; Kelly, Kristen M; Tromberg, Bruce J

2015-06-01

The combined use of nonlinear optical microscopy and broadband reflectance techniques to assess melanin concentration and distribution thickness in vivo over the full range of Fitzpatrick skin types is presented. Twelve patients were measured using multiphoton microscopy (MPM) and spatial frequency domain spectroscopy (SFDS) on both dorsal forearm and volar arm, which are generally sun-exposed and non-sun-exposed areas, respectively. Both MPM and SFDS measured melanin volume fractions between (skin type I non-sun-exposed) and 20% (skin type VI sun exposed). MPM measured epidermal (anatomical) thickness values ~30-65 μm, while SFDS measured melanin distribution thickness based on diffuse optical path length. There was a strong correlation between melanin concentration and melanin distribution (epidermal) thickness measurements obtained using the two techniques. While SFDS does not have the ability to match the spatial resolution of MPM, this study demonstrates that melanin content as quantified using SFDS is linearly correlated with epidermal melanin as measured using MPM (R² = 0.8895). SFDS melanin distribution thickness is correlated to MPM values (R² = 0.8131). These techniques can be used individually and/or in combination to advance our understanding and guide therapies for pigmentation-related conditions as well as light-based treatments across a full range of skin types.

Effect on radioactivity concentration estimation of radon progenies with NaI(Tl) pulse height distribution from considering geometric structure around detector and infiltration of radionuclides.

PubMed

Hirouchi, J; Terasaka, Y; Hirao, S; Moriizumi, J; Yamazawa, H

2015-11-01

The surface radioactivity concentrations of the radon progenies, (214)Pb and (214)Bi, were estimated from NaI(Tl) pulse height distributions during rain. The improvement in estimation errors caused by considering geometric structures around measuring points and infiltration of radionuclides was discussed. The surface radioactivity concentrations were determined by comparing the count rates at the full-energy peak ranges between observation and calculation with the electron-photon transport code EGS5. It was shown that the concentrations can be underestimated by about 30 % unless the obstacles around the detector or infiltration of radionuclides are considered in gamma ray transfer calculations at measuring points, where there are many tall obstacles, or the ground is covered with unpaved areas. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Transduction in Drosophila olfactory receptor neurons is invariant to air speed

PubMed Central

Zhou, Yi

2012-01-01

In the vertebrate nose, increasing air speed tends to increase the magnitude of odor-evoked activity in olfactory receptor neurons (ORNs), given constant odor concentration and duration. It is often assumed that the same is true of insect olfactory organs, but this has not been directly tested. In this study, we examined the effect of air speed on ORN responses in Drosophila melanogaster. We constructed an odor delivery device that allowed us to independently vary concentration and air speed, and we used a fast photoionization detector to precisely measure the actual odor concentration at the antenna while simultaneously recording spikes from ORNs in vivo. Our results demonstrate that Drosophila ORN odor responses are invariant to air speed, as long as odor concentration is kept constant. This finding was true across a >100-fold range of air speeds. Because odor hydrophobicity has been proposed to affect the air speed dependence of olfactory transduction, we tested a >1,000-fold range of hydrophobicity values and found that ORN responses are invariant to air speed across this full range. These results have implications for the mechanisms of odor delivery to Drosophila ORNs. Our findings are also significant because flies have a limited ability to control air flow across their antennae, unlike terrestrial vertebrates, which can control air flow within their nasal cavity. Thus, for the fly, invariance to air speed may be adaptive because it confers robustness to changing wind conditions. PMID:22815404

PTFE-based microreactor system for the continuous synthesis of full-visible-spectrum emitting cesium lead halide perovskite nanocrystals.

PubMed

Zhang, Chengxi; Luan, Weiling; Yin, Yuhang; Yang, Fuqian

2017-01-01

Colloidal perovskite nanocrystals comprised of all inorganic cesium lead halide (CsPbX 3 , X = Cl, Br, I or a mixture thereof) have potential as optical gain materials due to their high luminescence efficiency. In this work, cesium lead halide nanocrystals are continuously synthesized via a microreactor system consisting of poly(tetrafluoroethylene) (PTFE) capillaries. The synthesized nanocrystals possess excellent optical properties, including a full width at half maximum of 19-35 nm, high fluorescence quantum yield of 47.8-90.55%, and photoluminescence emission in the range of 450-700 nm. For the same precursor concentrations, the photoluminescence emission peak generally increases with increasing reaction temperature, revealing a controllable temperature effect on the photoluminescence characteristics of the synthesized nanocrystals. For quantum dots synthesized with a Br/I ratio of 1:3, a slight blue shift was observed for reaction temperatures greater than 100 °C. This PTFE-based microreactor system provides the unique capability of continuously synthesizing high-quality perovskite nanocrystals that emit over the full visible spectrum with applications ranging from displays and optoelectronic devices.

PTFE-based microreactor system for the continuous synthesis of full-visible-spectrum emitting cesium lead halide perovskite nanocrystals

PubMed Central

Zhang, Chengxi; Yin, Yuhang

2017-01-01

Colloidal perovskite nanocrystals comprised of all inorganic cesium lead halide (CsPbX3, X = Cl, Br, I or a mixture thereof) have potential as optical gain materials due to their high luminescence efficiency. In this work, cesium lead halide nanocrystals are continuously synthesized via a microreactor system consisting of poly(tetrafluoroethylene) (PTFE) capillaries. The synthesized nanocrystals possess excellent optical properties, including a full width at half maximum of 19–35 nm, high fluorescence quantum yield of 47.8–90.55%, and photoluminescence emission in the range of 450–700 nm. For the same precursor concentrations, the photoluminescence emission peak generally increases with increasing reaction temperature, revealing a controllable temperature effect on the photoluminescence characteristics of the synthesized nanocrystals. For quantum dots synthesized with a Br/I ratio of 1:3, a slight blue shift was observed for reaction temperatures greater than 100 °C. This PTFE-based microreactor system provides the unique capability of continuously synthesizing high-quality perovskite nanocrystals that emit over the full visible spectrum with applications ranging from displays and optoelectronic devices. PMID:29259867

Influence of natural organic matter on the screening of pharmaceuticals in water by using liquid chromatography with full scan mass spectrometry.

PubMed

Rivera, Zahira Herrera; Oosterink, Efraim; Rietveld, Luuk; Schoutsen, Frans; Stolker, Linda

2011-08-26

The influence of natural organic matter on the screening of pharmaceuticals in water was determined by using high resolution liquid chromatography (HRLC) combined with full scan mass spectrometry (MS) techniques like time of flight (ToF) or Orbitrap MS. Water samples containing different amount of natural organic matter (NOM) and residues of a set of 11 pharmaceuticals were analyzed by using Exactive Orbitrap™ LC-MS. The samples were screened for residues of pharmaceuticals belonging to different classes like benzimidazoles, macrolides, penicillins, quinolones, sulfonamides, tetracyclines, tranquillizers, non-steroidal anti-inflammatory drugs (NSAIDs), anti-epileptics and lipid regulators. The method characteristics were established over a concentration range of 0.1-500 μg L(-1). The 11 pharmaceuticals were added to two effluent and two influent water samples. The NOM concentration within the samples ranged from 2 to 8 mg L(-1) of dissolved organic carbon. The HRLC-Exactive Orbitrap™ LC-MS system was set at a resolution of 50,000 (FWHM) and this selection was found sufficient for the detection of the list of pharmaceuticals. With this resolution setting, accurate mass measurements with errors below 2 ppm were found, despite of the NOM concentration of the different types of water samples. The linearities were acceptable with correlation coefficients greater than 0.95 for 30 of the 51 measured linearities. The limit of detection varies between 0.1 μg L(-1)and 100 μg L(-1). It was demonstrated that sensitivity could be affected by matrix constituents in both directions of signal reduction or enhancement. Finally it was concluded that with direct shoot method used (no sample pretreatment) all compounds, were detected but LODs depend on matrix-analyte-concentration combination. No direct relation was observed between NOM concentration and method characteristics. For accurate quantification the use of internal standards and/or sample clean-up is necessary. The direct shoot method is only applicable for qualitative screening purposes. The use of full scan MS makes it possible to search for unknown contaminants. With the use of adequate software and a database containing more than 50,000 entries a tool is available to search for unknowns. Copyright © 2011 Elsevier B.V. All rights reserved.

AERMOD performance evaluation for three coal-fired electrical generating units in Southwest Indiana.

PubMed

Frost, Kali D

2014-03-01

An evaluation of the steady-state dispersion model AERMOD was conducted to determine its accuracy at predicting hourly ground-level concentrations of sulfur dioxide (SO2) by comparing model-predicted concentrations to a full year of monitored SO2 data. The two study sites are comprised of three coal-fired electrical generating units (EGUs) located in southwest Indiana. The sites are characterized by tall, buoyant stacks,flat terrain, multiple SO2 monitors, and relatively isolated locations. AERMOD v12060 and AERMOD v12345 with BETA options were evaluated at each study site. For the six monitor-receptor pairs evaluated, AERMOD showed generally good agreement with monitor values for the hourly 99th percentile SO2 design value, with design value ratios that ranged from 0.92 to 1.99. AERMOD was within acceptable performance limits for the Robust Highest Concentration (RHC) statistic (RHC ratios ranged from 0.54 to 1.71) at all six monitors. Analysis of the top 5% of hourly concentrations at the six monitor-receptor sites, paired in time and space, indicated poor model performance in the upper concentration range. The amount of hourly model predicted data that was within a factor of 2 of observations at these higher concentrations ranged from 14 to 43% over the six sites. Analysis of subsets of data showed consistent overprediction during low wind speed and unstable meteorological conditions, and underprediction during stable, low wind conditions. Hourly paired comparisons represent a stringent measure of model performance; however given the potential for application of hourly model predictions to the SO2 NAAQS design value, this may be appropriate. At these two sites, AERMOD v12345 BETA options do not improve model performance. A regulatory evaluation of AERMOD utilizing quantile-quantile (Q-Q) plots, the RHC statistic, and 99th percentile design value concentrations indicates that model performance is acceptable according to widely accepted regulatory performance limits. However, a scientific evaluation examining hourly paired monitor and model values at concentrations of interest indicates overprediction and underprediction bias that is outside of acceptable model performance measures. Overprediction of 1-hr SO2 concentrations by AERMOD presents major ramifications for state and local permitting authorities when establishing emission limits.

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

PubMed

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

2012-12-28

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

Blood harmane, blood lead, and severity of hand tremor: evidence of additive effects.

PubMed

Louis, Elan D; Factor-Litvak, Pam; Gerbin, Marina; Slavkovich, Vesna; Graziano, Joseph H; Jiang, Wendy; Zheng, Wei

2011-03-01

Tremor is a widespread phenomenon in human populations. Environmental factors are likely to play an etiological role. Harmane (1-methyl-9H-pyrido[3,4-β]indole) is a potent tremor-producing β-carboline alkaloid. Lead is another tremor-producing neurotoxicant. The effects of harmane and lead with respect to tremor have been studied in isolation. We tested the hypothesis that tremor would be particularly severe among individuals who had high blood concentrations of both of these toxicants. Blood concentrations of harmane and lead were each quantified in 257 individuals (106 essential tremor cases and 151 controls) enrolled in an environmental epidemiological study. Total tremor score (range = 0-36) was a clinical measure of tremor severity. The total tremor score ranged from 0 to 36, indicating that a full spectrum of tremor severities was captured in our sample. Blood harmane concentration correlated with total tremor score (p = 0.007), as did blood lead concentration (p = 0.045). The total tremor score was lowest in participants with both low blood harmane and lead concentrations (8.4 ± 8.2), intermediate in participants with high concentrations of either toxicant (10.5 ± 9.8), and highest in participants with high concentrations of both toxicants (13.7 ± 10.4) (p=0.01). Blood harmane and lead concentrations separately correlated with total tremor scores. Participants with high blood concentrations of both toxicants had the highest tremor scores, suggesting an additive effect of these toxicants on tremor severity. Given the very high population prevalence of tremor disorders, identifying environmental determinants is important for primary disease prevention. Copyright © 2010 Elsevier Inc. All rights reserved.

Blood Harmane, Blood Lead, and Severity of Hand Tremor: Evidence of Additive Effects

PubMed Central

Louis, Elan D.; Factor-Litvak, Pam; Gerbin, Marina; Slavkovich, Vesna; Graziano, Joseph H; Jiang, Wendy; Zheng, Wei

2010-01-01

Background Tremor is a widespread phenomenon in human populations. Environmental factors are likely to play an etiological role. Harmane (1-methyl-9H-pyrido[3,4-β]indole) is a potent tremor-producing β-carboline alkaloid. Lead is another tremor-producing neurotoxicant. The effects of harmane and lead with respect to tremor have been studied in isolation. Objectives We tested the hypothesis that tremor would be particularly severe among individuals who had high blood concentrations of both of these toxicants. Methods Blood concentrations of harmane and lead were each quantified in 257 individuals (106 essential tremor cases and 151 controls) enrolled in an environmental epidemiological study. Total tremor score (range = 0 – 36) was a clinical measure of tremor severity. Results The total tremor score ranged from 0 – 36, indicating that a full spectrum of tremor severities was captured in our sample. Blood harmane concentration correlated with total tremor score (p = 0.007), as did blood lead concentration (p = 0.045). The total tremor score was lowest in participants with both low blood harmane and lead concentrations (8.4 ± 8.2), intermediate in participants with high concentrations of either toxicant (10.5 ± 9.8), and highest in participants with high concentrations of both toxicants (13.7 ± 10.4)(p = 0.01). Conclusions Blood harmane and lead concentrations separately correlated with total tremor scores. Participants with high blood concentrations of both toxicants had the highest tremor scores, suggesting an additive effect of these toxicants on tremor severity. Given the very high population prevalence of tremor disorders, identifying environmental determinants is important for primary disease prevention. PMID:21145352

Application of High-Throughput In Vitro Assays for Risk-Based ...

EPA Pesticide Factsheets

Multiple drivers shape the types of human-health assessments performed on chemicals by U.S. EPA resulting in chemical assessments are “fit-for-purpose” ranging from prioritization for further testing to full risk assessments. Layered on top of the diverse assessment needs are the resource intensive nature of traditional toxicological studies used to test chemicals and the lack of toxicity information on many chemicals. To address these challenges, the Agency initiated the ToxCast program to screen thousands of chemicals across hundreds of high-throughput screening assays in concentrations-response format. One of the findings of the project has been that the majority of chemicals interact with multiple biological targets within a narrow concentration range and the extent of interactions increases rapidly near the concentration causing cytotoxicity. This means that application of high-throughput in vitro assays to chemical assessments will need to identify both the relative selectivity at chemicals interact with biological targets and the concentration at which these interactions perturb signaling pathways. The integrated analyses will be used to both define a point-of-departure for comparison with human exposure estimates and identify which chemicals may benefit from further studies in a mode-of-action or adverse outcome pathway framework. The application of new technologies in a risk-based, tiered manner provides flexibility in matching throughput and cos

A synthesis of AOT40-based response functions and critical levels of ozone for agricultural and horticultural crops

NASA Astrophysics Data System (ADS)

Mills, G.; Buse, A.; Gimeno, B.; Bermejo, V.; Holland, M.; Emberson, L.; Pleijel, H.

Crop-response data from over 700 published papers and conference proceedings have been analysed with the aim of establishing ozone dose-response functions for a wide range of European agricultural and horticultural crops. Data that met rigorous selection criteria (e.g. field-based, ozone concentrations within European range, full season exposure period) were used to derive AOT40-yield response functions for 19 crops by first converting the published ozone concentration data into AOT40 (AOT40 is the hourly mean ozone concentration accumulated over a threshold ozone concentration of 40 ppb during daylight hours, units ppm h). For any individual crop, there were no significant differences in the linear response functions derived for experiments conducted in the USA or Europe, or for individual cultivars. Three statistically independent groups were identified: ozone sensitive crops (wheat, water melon, pulses, cotton, turnip, tomato, onion, soybean and lettuce); moderately sensitive crops (sugar beet, potato, oilseed rape, tobacco, rice, maize, grape and broccoli) and ozone resistant (barley and fruit represented by plum and strawberry). Critical levels of a 3 month AOT40 of 3 ppm h and a 3.5 month AOT40 of 6 ppm h were derived from the functions for wheat and tomato, respectively.

20150325 - Application of High-Throughput In Vitro Assays for ...

EPA Pesticide Factsheets

Multiple drivers shape the types of human-health assessments performed on chemicals by U.S. EPA resulting in chemical assessments are “fit-for-purpose” ranging from prioritization for further testing to full risk assessments. Layered on top of the diverse assessment needs are the resource intensive nature of traditional toxicological studies used to test chemicals and the lack of toxicity information on many chemicals. To address these challenges, the Agency initiated the ToxCast program to screen thousands of chemicals across hundreds of high-throughput screening assays in concentrations-response format. One of the findings of the project has been that the majority of chemicals interact with multiple biological targets within a narrow concentration range and the extent of interactions increases rapidly near the concentration causing cytotoxicity. This means that application of high-throughput in vitro assays to chemical assessments will need to identify both the relative selectivity at chemicals interact with biological targets and the concentration at which these interactions perturb signaling pathways. The integrated analyses will be used to both define a point-of-departure for comparison with human exposure estimates and identify which chemicals may benefit from further studies in a mode-of-action or adverse outcome pathway framework. The application of new technologies in a risk-based, tiered manner provides flexibility in matching throughput and cos

A differential absorption lidar instrument for the measurment of carbon dioxide and methane in the lower troposphere (Conference Presentation)

NASA Astrophysics Data System (ADS)

Budinov, Daniel; Clements, Robert; Rae, Cameron F.; Moncrieff, John B.; Jack, James W.

2016-12-01

Developments in the remote detection of trace gases in the atmosphere using Differential Absorption Lidar have been driven largely by improvements in two key technologies: lasers and detectors. We have designed and built a narrow linewidth pulsed laser source with a well-controlled output wavelength and sufficient pulse energy to measure the concentration profile of CO2 and CH4 to a range in excess of 4km. We describe here the initial measurements of concentration profiles recorded with this instrument. The system is built around a custom-designed Newtonian telescope with a 40cm diameter primary mirror. Laser sources and detectors attach directly to the side of the telescope allowing for flexible customization with a range of additional equipment. The instrument features an all-solid-state laser source based on an optical parametric oscillator (OPO) pumped by an YLF based diode-laser pumped solid-state laser and seeded by a tuned DFB seed. This provides a range of available wavelengths suitable for DIAL within the 1.5-1.6 μm spectral region. The output of the OPO is beam expanded and transmitted coaxially from the receiver telescope. A gas cell within the laser source controls the seed wavelength and allows the wavelength to be tuned to match a specific absorption feature of the selected gas species. The source can be rapidly tuned between the on-line and off-line wavelengths to make a DIAL measurement of either CO2 or CH4 The receiver is based on an InGaAs avalanche photodetector. Whilst photodiode detectors are a low-cost solution their limited sensitivity restricts the maximum range over which a signal can be detected. The receiver signal is digitised for subsequent processing to produce a sightline concentration profile. The instrument is mounted on a robust gimballed mount providing full directional movement within the upper hemisphere. Both static pointing and angular scan modes are available. Accurate angular position is available giving the sightline vector and supporting the interpretation of the concentration profile. Initial measurements have been made in the planetary boundary layer above the City of Edinburgh and these will be presented and discussed. Earlier measurements demonstrated that the signal from atmospheric scatter could be detected at ranges in excess of 6km. The later measurements have shown scatter signals at greater ranges, but with increasing noise at the longer ranges. This is expected as the signal decreases with the inverse of the range whereas the noise remains effectively constant. Range resolved concentration profiles for sightline vectors lying within an angular sector have been used to create a 3D map of concentration for that volume. This will be presented and discussed.

Relating N2O emissions during biological nitrogen removal with operating conditions using multivariate statistical techniques.

PubMed

Vasilaki, V; Volcke, E I P; Nandi, A K; van Loosdrecht, M C M; Katsou, E

2018-04-26

Multivariate statistical analysis was applied to investigate the dependencies and underlying patterns between N 2 O emissions and online operational variables (dissolved oxygen and nitrogen component concentrations, temperature and influent flow-rate) during biological nitrogen removal from wastewater. The system under study was a full-scale reactor, for which hourly sensor data were available. The 15-month long monitoring campaign was divided into 10 sub-periods based on the profile of N 2 O emissions, using Binary Segmentation. The dependencies between operating variables and N 2 O emissions fluctuated according to Spearman's rank correlation. The correlation between N 2 O emissions and nitrite concentrations ranged between 0.51 and 0.78. Correlation >0.7 between N 2 O emissions and nitrate concentrations was observed at sub-periods with average temperature lower than 12 °C. Hierarchical k-means clustering and principal component analysis linked N 2 O emission peaks with precipitation events and ammonium concentrations higher than 2 mg/L, especially in sub-periods characterized by low N 2 O fluxes. Additionally, the highest ranges of measured N 2 O fluxes belonged to clusters corresponding with NO 3 -N concentration less than 1 mg/L in the upstream plug-flow reactor (middle of oxic zone), indicating slow nitrification rates. The results showed that the range of N 2 O emissions partially depends on the prior behavior of the system. The principal component analysis validated the findings from the clustering analysis and showed that ammonium, nitrate, nitrite and temperature explained a considerable percentage of the variance in the system for the majority of the sub-periods. The applied statistical methods, linked the different ranges of emissions with the system variables, provided insights on the effect of operating conditions on N 2 O emissions in each sub-period and can be integrated into N 2 O emissions data processing at wastewater treatment plants. Copyright © 2018. Published by Elsevier Ltd.

The long range transport of birch (Betula) pollen from Poland and Germany causes significant pre-season concentrations in Denmark

NASA Astrophysics Data System (ADS)

Ambelas Skjoth, C.; Sommer, J.; Stach, A.; Smith, M.; Brandt, J.; Christensen, J. H.; Frohn, L. M.; Geels, C.; Hansen, K. M.; Hedegaard, G. B.

2009-04-01

In Denmark, where birch pollen is considered to be among the most important allergenic pollen, about one million people suffer from seasonal allergic rhinitis. In Denmark, the official reported pollen forecast is based on the daily weather forecast, the pollen calendar and local 24-h measurements. Birch pollen has the potential for long-range transport but the present Danish pollen forecast does not account for birch pollen being transported into the country from distant sources.. Long-range transport episodes are intermittent and often out of the main pollen season, where individuals in general will be medically unprotected. Here we use an integrated approach to investigate whether or not Denmark receives significant quantities of birch pollen from Poland and Germany before local trees start to flower. In 2006 we used a combination of phenological observations and pollen measurements in Poland (Poznań) and Denmark (Copenhagen). Seasonal and diurnal variations in birch pollen measurement from Copenhagen (2000-2006) were examined with the aim of identifying pre-seasonal episodes originating from long-range transport. The 2.5% accumulation method was used for identifying start of season. If daily pollen counts exceeded 30 grains/m3 either before the local flowering season began or on the actual start day, the episode was chosen for investigation with back trajectory analysis. A birch forest inventory for Northern Europe was produced and implemented in DEHM-Pollen along with a simple unified pollen release model SUPREME to investigate the 2006 campaign in detail. In 2006, full flowering took place in Poznan between 20th and 28th of April and daily concentrations varied between 739 and 2169 grains/m3. In Copenhagen phenological observations showed that local flowering was initiated the 2nd of May. In Copenhagen several episodes with pollen concentrations at 108, 244 and 41 grains/m3 were recorded the 23rd, 26th and 27th of April, respectively. Back-trajectory analysis showed that for those tree dates the origin of the air masses was Poland including the Poznan region. 11 possible pre-seasonal long-range transport episodes in 2000-2006 were identified during analyses of the measured pollen data. All possible long-range transport episodes were investigated with back trajectories. In all investigated episodes, the air masses Copenhagen originated directly from either Germany or Poland. The model results from DEHM pollen for 2006 show several episodes in Copenhagen with high pollen concentration for the 23rd - 24th and 26th - 27th of April, respectively. These pre-seasonal peaks in 2006 were modelled well with respect to timing and magnitude. During this period the SUPREME model only predicts birch pollen emission south of Denmark. Long-range transport episodes of birch pollen from Poland and Germany has happened almost every year since 2000 and it is therefore likely that this is a general pattern. It is shown that DEHM-Pollen for the year 2006 is able to simulate pre-seasonal pollen concentrations in Denmark, where key components include a well calibrated emission model and emission inventory. Furthermore, all model components are prepared for full implementation in the THOR air pollution and forecasting system. During pre-seasonal, pollen allergy patients are in general medically unprotected. Such episodes will therefore have a full impact with respect to allergic reactions among the allergy patients. The use of the integrated approach improves knowledge of such episodes. Furthermore, an implementation of DEHM-Pollen in the THOR system has the potential to provide early warnings of severe pre-seasonal pollen episodes to the entire Danish population, by forecasting how far and how severe a possible pre-seasonal birch pollen cloud will progress into Denmark.

Variation in Nectar Volume and Sugar Concentration of Allium ursinum L. ssp. ucrainicum in Three Habitats

PubMed Central

Farkas, Ágnes; Molnár, Réka; Morschhauser, Tamás; Hahn, István

2012-01-01

Floral nectar volume and concentration of ramson (Allium ursinum L. ssp. ucrainicum) were investigated in three different habitats, including two types of sessile oak-hornbeam association on brown forest soil with clay illuviation and a silver lime-flowering ash rock forest association on rendzina. Daily nectar production ranged from 0.1 to 3.8 μL per flower with sugar concentrations of 25 to 50%. Mean nectar volumes and concentrations showed significant differences between freely exposed flowers and covered flowers, which had been isolated from flower visitors 24 h prior to nectar studies. Both the amount and quality of nectar were affected by microclimatic conditions and soil properties and varied between populations at different habitats. In the silver lime-flowering ash rock-forest association mean nectar volumes and concentrations were lower than in a typical sessile oak-hornbeam association on three occasions, the difference being significant in two cases. During full bloom, the date of sampling did not have a profound effect on either nectar volume or concentration. PMID:22619588

Radiation dose to workers due to the inhalation of dust during granite fabrication.

PubMed

Zwack, L M; McCarthy, W B; Stewart, J H; McCarthy, J F; Allen, J G

2014-03-01

There has been very little research conducted to determine internal radiation doses resulting from worker exposure to ionising radiation in granite fabrication shops. To address this issue, we estimated the effective radiation dose of granite workers in US fabrication shops who were exposed to the maximum respirable dust and silica concentrations allowed under current US regulations, and also to concentrations reported in the literature. Radiation doses were calculated using standard methods developed by the International Commission on Radiological Protection. The calculated internal doses were very low, and below both US occupational standards (50 mSv yr(-1)) and limits applicable to the general public (1 mSv yr(-1)). Workers exposed to respirable granite dust concentrations at the US Occupational Safety and Health Administration (OSHA) respirable dust permissible exposure limit (PEL) of 5 mg m(-3) over a full year had an estimated radiation dose of 0.062 mSv yr(-1). Workers exposed to respirable granite dust concentrations at the OSHA silica PEL and at the American Conference of Governmental Industrial Hygienists Threshold Limit Value for a full year had expected radiation doses of 0.007 mSv yr(-1) and 0.002 mSv yr(-1), respectively. Using data from studies of respirable granite dust and silica concentrations measured in granite fabrication shops, we calculated median expected radiation doses that ranged from <0.001 to 0.101 mSv yr(-1).

Non-omnia moriantur-toxicity of mancozeb on dead wood microarthropod fauna.

PubMed

Adamski, Zbigniew; Bloszyk, Jerzy; Bruin, Jan; Ziemnicki, Kazimierz

2007-01-01

The effect of Dithane M-45 (dithiocarbamate fungicide; active substance: mancozeb) was studied on microarthropod fauna inhabiting dead wood. Although the exposure was almost never 100% lethal for the majority of observed taxa, almost all (Mesostigmata, Oribatida, some Uropodina, Actinedida, Collembola and Diplopoda) showed very high correlation between concentration of the fungicide and mortality (r > 0.86). Only Stigmaeidae showed low correlation (r = 0.293). For the majority of taxa LC(50 )values were close to the concentrations used during agrochemical activities in woods. Only Trachytes aegrota showed full susceptibility to the fungicide within the range of recommended field concentrations used in forestry (characterised by the low LC(95 )value). Tolerance of mesostigmatid and oribatid mites was found to differ between juveniles and adults, but not consistently. Related Uropodina species varied in susceptibility to the fungicide.

Persistent inflammation and recovery after intensive care: A systematic review.

PubMed

Griffith, David M; Vale, Matthew E; Campbell, Christine; Lewis, Steff; Walsh, Timothy S

2016-06-01

Physical weakness is common after critical illness; however, it is not clear how best to treat it. Inflammation characterizes critical illness, is associated with loss of muscle mass during critical illness, and potentially modifies post-intensive care unit (ICU) recovery. We sought to identify published reports on the prevalence of systemic inflammation after critical illness and its association with physical recovery. This is a systematic review of the literature from MEDLINE, EMBASE, CINAHL, CPCI-SSH, and CPCI-S from January 1982 to December 2011. From 7433 references, 207 full-text articles were reviewed, 57 were eligible, and 22 were included. Inflammation was present in most patients at ICU discharge according to C-reactive protein concentration (range, 70%-100%), procalcitonin (range, 89%-100%), tumor necrosis factor α (100%), and systemic inflammatory response syndrome criteria (range, 92%-95%). Fewer patients had elevated myeloperoxidase concentrations (range, 0%-56%). At hospital discharge, 9 (90%) of 10 chronic obstructive pulmonary disease patients had elevated C-reactive protein. No studies tested the association between inflammation and physical recovery. Inflammation is present in most patients at ICU discharge, but little is known or has been investigated about persistent inflammation after this time point. No studies have explored the relationship between persistent inflammation and physical recovery. Further research is proposed. Copyright © 2016 Elsevier Inc. All rights reserved.

In vivo measurements of cutaneous melanin across spatial scales: using multiphoton microscopy and spatial frequency domain spectroscopy

PubMed Central

Saager, Rolf B.; Balu, Mihaela; Crosignani, Viera; Sharif, Ata; Durkin, Anthony J.; Kelly, Kristen M.; Tromberg, Bruce J.

2015-01-01

Abstract. The combined use of nonlinear optical microscopy and broadband reflectance techniques to assess melanin concentration and distribution thickness in vivo over the full range of Fitzpatrick skin types is presented. Twelve patients were measured using multiphoton microscopy (MPM) and spatial frequency domain spectroscopy (SFDS) on both dorsal forearm and volar arm, which are generally sun-exposed and non-sun-exposed areas, respectively. Both MPM and SFDS measured melanin volume fractions between ∼5% (skin type I non-sun-exposed) and 20% (skin type VI sun exposed). MPM measured epidermal (anatomical) thickness values ∼30–65  μm, while SFDS measured melanin distribution thickness based on diffuse optical path length. There was a strong correlation between melanin concentration and melanin distribution (epidermal) thickness measurements obtained using the two techniques. While SFDS does not have the ability to match the spatial resolution of MPM, this study demonstrates that melanin content as quantified using SFDS is linearly correlated with epidermal melanin as measured using MPM (R2=0.8895). SFDS melanin distribution thickness is correlated to MPM values (R2=0.8131). These techniques can be used individually and/or in combination to advance our understanding and guide therapies for pigmentation-related conditions as well as light-based treatments across a full range of skin types. PMID:26065839

Uncertainties of stormwater characteristics and removal rates of stormwater treatment facilities: implications for stormwater handling.

PubMed

Langeveld, J G; Liefting, H J; Boogaard, F C

2012-12-15

Stormwater runoff is a major contributor to the pollution of receiving waters. This study focuses at characterising stormwater in order to be able to determine the impact of stormwater on receiving waters and to be able to select the most appropriate stormwater handling strategy. The stormwater characterisation is based on determining site mean concentrations (SMCs) and their uncertainties as well as the treatability of stormwater by monitoring specific pollutants concentration levels (TSS, COD, BOD, TKN, TP, Pb, Cu, Zn, E.coli) at three full scale stormwater treatment facilities in Arnhem, the Netherlands. This has resulted in 106 storm events being monitored at the lamella settler, 59 at the high rate sand filter and 132 at the soil filter during the 2 year monitoring period. The stormwater characteristics in Arnhem in terms of SMCs for main pollutants TSS and COD and settling velocities differ from international data. This implies that decisions for stormwater handling made on international literature data will very likely be wrong due to assuming too high concentrations of pollutants and misjudgement of the treatability of stormwater. The removal rates monitored at the full scale treatment facilities are within the expected range, with the soil filter and the sand filter having higher removal rates than the lamella settler. The full scale pilots revealed the importance of incorporating gross solids removal in the design of stormwater treatment facilities, as the gross solids determine operation and maintenance requirements. Copyright © 2012 Elsevier Ltd. All rights reserved.

Fiber-Optic Ammonia Sensors

NASA Technical Reports Server (NTRS)

Carter, Michael T.

2003-01-01

Reversible, colorimetric fiber-optic sensors are undergoing development for use in measuring concentrations of ammonia in air at levels relevant to human health [0 to 50 parts per million (ppm)]. A sensor of this type includes an optical fiber that has been modified by replacing a portion of its cladding with a polymer coat that contains a dye that reacts reversibly with ammonia and changes color when it does so. The change in color is measured as a change in the amount of light transmitted from one end of the fiber to the other. Responses are reversible and proportional to the concentration of ammonia over the range from 9 to 175 ppm and in some cases the range of reversibility extends up to 270 ppm. The characteristic time for the response of a sensor to rise from 10 to 90 percent of full scale is about 25 seconds. These sensors are fully operational in pure carbon dioxide and are not adversely affected by humidity. This work was done by Michael T. Carter

Self-Interacting Dark Matter Can Explain Diverse Galactic Rotation Curves

NASA Astrophysics Data System (ADS)

Kamada, Ayuki; Kaplinghat, Manoj; Pace, Andrew B.; Yu, Hai-Bo

2017-09-01

The rotation curves of spiral galaxies exhibit a diversity that has been difficult to understand in the cold dark matter (CDM) paradigm. We show that the self-interacting dark matter (SIDM) model provides excellent fits to the rotation curves of a sample of galaxies with asymptotic velocities in the 25 - 300 km /s range that exemplify the full range of diversity. We assume only the halo concentration-mass relation predicted by the CDM model and a fixed value of the self-interaction cross section. In dark-matter-dominated galaxies, thermalization due to self-interactions creates large cores and reduces dark matter densities. In contrast, thermalization leads to denser and smaller cores in more luminous galaxies and naturally explains the flatness of rotation curves of the highly luminous galaxies at small radii. Our results demonstrate that the impact of the baryons on the SIDM halo profile and the scatter from the assembly history of halos as encoded in the concentration-mass relation can explain the diverse rotation curves of spiral galaxies.

Charging of mesospheric particles - Implications for electron density and particle coagulation

NASA Technical Reports Server (NTRS)

Jensen, Eric J.; Thomas, Gary E.

1991-01-01

The relationship between N(e) and mesospheric aerosols near the mesopause is studied. The full distribution of charges on mesospheric aerosols is calculated, including dust and ice particles with radii ranging from 1 to 400 nm. The N(e) and ion density N(i) are obtained and ionization height profiles are calculated. The effects of dust and ice particles on N(e) and N(i) are studied for a wide range of assumed conditions. The results indicate that aerosol concentrations associated with visible polar mesospheric clouds are unlikely to cause a severe N(e) depletion. The pronounced 'bite-out' of N(e) at about 87 km in the summertime may be caused by a large concentration of small ice particles in a narrow cold layer near the mesosphere. Net negative charge on mesospheric aerosols may severely inihibit coagulation, so that mesospheric dust would not grow significantly. A higher supersaturation with respect to water vapor would be needed for heterogeneous nucleation of ice crystals.

Hybrid micro-scale photovoltaics for enhanced energy conversion across all irradiation conditions

NASA Astrophysics Data System (ADS)

Agrawal, Gautam

A novel hybrid photovoltaics (HPV) architecture is presented that integrates high-performance micro-optics-based concentrator photovoltaics (CPV) array technology with a 1-sun photovoltaic (PV) cell within a low-profile panel structure. The approach simultaneously captures the direct solar radiation components with arrayed high-efficiency CPV cells and the diffuse solar components with an underlying wide-area PV cell. Performance analyses predict that the hybrid approach will significantly enhance the average energy produced per unit area for the full range of diffuse/direct radiation patterns across the USA. Furthermore, cost analyses indicate that the hybrid concept may be financially attractive for a wide range of locations. Indoor and outdoor experimental evaluation of a micro-optical system designed for use in a hybrid architecture verified that a large proportion of the direct radiation component was concentrated onto emulated micro-cell regions while most of the diffuse radiation and the remaining direct radiation was collected in the 1-sun cell area.

Self-Interacting Dark Matter Can Explain Diverse Galactic Rotation Curves.

PubMed

Kamada, Ayuki; Kaplinghat, Manoj; Pace, Andrew B; Yu, Hai-Bo

2017-09-15

The rotation curves of spiral galaxies exhibit a diversity that has been difficult to understand in the cold dark matter (CDM) paradigm. We show that the self-interacting dark matter (SIDM) model provides excellent fits to the rotation curves of a sample of galaxies with asymptotic velocities in the 25-300  km/s range that exemplify the full range of diversity. We assume only the halo concentration-mass relation predicted by the CDM model and a fixed value of the self-interaction cross section. In dark-matter-dominated galaxies, thermalization due to self-interactions creates large cores and reduces dark matter densities. In contrast, thermalization leads to denser and smaller cores in more luminous galaxies and naturally explains the flatness of rotation curves of the highly luminous galaxies at small radii. Our results demonstrate that the impact of the baryons on the SIDM halo profile and the scatter from the assembly history of halos as encoded in the concentration-mass relation can explain the diverse rotation curves of spiral galaxies.

Evaluation of COSHH essentials: methylene chloride, isopropanol, and acetone exposures in a small printing plant.

PubMed

Lee, Eun Gyung; Harper, Martin; Bowen, Russell B; Slaven, James

2009-07-01

The current study evaluated the Control of Substances Hazardous to Health (COSHH) Essentials model for short-term task-based exposures and full-shift exposures using measured concentrations of three volatile organic chemicals at a small printing plant. A total of 188 exposure measurements of isopropanol and 187 measurements of acetone were collected and each measurement took approximately 60 min. Historically, collected time-weighted average concentrations (seven results) were evaluated for methylene chloride. The COSHH Essentials model recommended general ventilation control for both isopropanol and acetone. There was good agreement between the task-based exposure measurements and the COSHH Essentials predicted exposure range (PER) for cleaning and print preparation with isopropanol and for cleaning with acetone. For the other tasks and for full-shift exposures, agreement between the exposure measurements and the PER was either moderate or poor. However, for both isopropanol and acetone, our findings suggested that the COSHH Essentials model worked reasonably well because the probabilities of short-term exposure measurements exceeding short-term occupational exposure limits (OELs) or full-shift exposures exceeding the corresponding full-shift OELs were <0.05 under the recommended control strategy. For methylene chloride, the COSHH Essentials recommended containment control but a follow-up study was not able to be performed because it had already been replaced with a less hazardous substance (acetone). This was considered a more acceptable alternative to increasing the level of control.

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

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

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

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

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

DOE PAGES

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

2016-12-20

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

The role of long-range transport and domestic emissions in determining atmospheric secondary inorganic particle concentrations across the UK

NASA Astrophysics Data System (ADS)

Vieno, M.; Heal, M. R.; Hallsworth, S.; Famulari, D.; Doherty, R. M.; Dore, A. J.; Tang, Y. S.; Braban, C. F.; Leaver, D.; Sutton, M. A.; Reis, S.

2014-08-01

Surface concentrations of secondary inorganic particle components over the UK have been analysed for 2001-2010 using the EMEP4UK regional atmospheric chemistry transport model and evaluated against measurements. Gas/particle partitioning in the EMEP4UK model simulations used a bulk approach, which may lead to uncertainties in simulated secondary inorganic aerosol. However, model simulations were able to accurately represent both the long-term decadal surface concentrations of particle sulfate and nitrate and an episode in early 2003 of substantially elevated nitrate measured across the UK by the AGANet network. The latter was identified as consisting of three separate episodes, each of less than 1 month duration, in February, March and April. The primary cause of the elevated nitrate levels across the UK was meteorological: a persistent high-pressure system, whose varying location impacted the relative importance of transboundary versus domestic emissions. Whilst long-range transport dominated the elevated nitrate in February, in contrast it was domestic emissions that mainly contributed to the March episode, and for the April episode both domestic emissions and long-range transport contributed. A prolonged episode such as the one in early 2003 can have substantial impact on annual average concentrations. The episode led to annual concentration differences at the regional scale of similar magnitude to those driven by long-term changes in precursor emissions over the full decade investigated here. The results demonstrate that a substantial part of the UK, particularly the south and southeast, may be close to or exceeding annual mean limit values because of import of inorganic aerosol components from continental Europe under specific conditions. The results reinforce the importance of employing multiple year simulations in the assessment of emissions reduction scenarios on particulate matter concentrations and the need for international agreements to address the transboundary component of air pollution.

Relationship between Environmental Phthalate Exposure and the Intelligence of School-Age Children

PubMed Central

Cho, Soo-Churl; Bhang, Soo-Young; Hong, Yun-Chul; Shin, Min-Sup; Kim, Boong-Nyun; Kim, Jae-Won; Yoo, Hee-Jung; Cho, In Hee; Kim, Hyo-Won

2010-01-01

Background Concern over phthalates has emerged because of their potential toxicity to humans. Objective We investigated the relationship between the urinary concentrations of phthalate metabolites and children’s intellectual functioning. Methods This study enrolled 667 children at nine elementary schools in five South Korean cities. A cross-sectional examination of urine phthalate concentrations was performed, and scores on neuropsychological tests were obtained from both the children and their mothers. Results We measured mono-2-ethylhexyl phthalate (MEHP) and mono(2-ethyl-5-oxohexyl)phthalate (MEOHP), both metabolites of di(2-ethylhexyl)phthalate (DEHP), and mono-n-butyl phthalate (MBP), a metabolite of dibutyl phthalate (DBP), in urine samples. The geometric mean (ln) concentrations of MEHP, MEOHP, and MBP were 21.3 μg/L [geometric SD (GSD) = 2.2 μg/L; range, 0.5–445.4], 18.0 μg/L (GSD = 2.4; range, 0.07–291.1), and 48.9 μg/L (GSD = 2.2; range, 2.1–1645.5), respectively. After adjusting for demographic and developmental covariates, the Full Scale IQ and Verbal IQ scores were negatively associated with DEHP metabolites but not with DBP metabolites. We also found a significant negative relationship between the urine concentrations of the metabolites of DEHP and DBP and children’s vocabulary subscores. After controlling for maternal IQ, a significant inverse relationship between DEHP metabolites and vocabulary subscale score remained. Among boys, we found a negative association between increasing MEHP phthalate concentrations and the sum of DEHP metabolite concentrations and Wechsler Intelligence Scale for Children vocabulary score; however, among girls, we found no significant association between these variables. Conclusion Controlling for maternal IQ and other covariates, the results show an inverse relationship between phthalate metabolites and IQ scores; however, given the limitations in cross-sectional epidemiology, prospective studies are needed to fully explore these associations. PMID:20194078

Early Serum Gut Hormone Concentrations Associated with Time to Full Enteral Feedings in Preterm Infants.

PubMed

Shanahan, Kristen H; Yu, Xinting; Miller, Laura G; Freedman, Steven D; Martin, Camilia R

2018-04-03

The primary objective of this study was to evaluate early postnatal serum gut hormone concentrations in preterm infants as predictors of time to full enteral feedings. The secondary objective was to identify infant characteristics and nutritional factors that modulate serum gut hormone concentrations and time to full enteral feedings. Sixty-four preterm infants less than 30 weeks of gestation were included in this retrospective cohort study. Serum gut hormone concentrations at postnatal days 0 and 7 were measured using enzyme-linked immunosorbent assays. Linear regression and mediation analyses were performed. Median (IQR) serum concentrations of glucose-dependent insulinotropic peptide (GIP) and peptide YY (PYY) on postnatal day 7 were 31.3 pg/mL (18.2, 52.3) and 1181.7 pg/mL (859.0, 1650.2), respectively. GIP and PYY concentrations on day 7 were associated with days to full enteral feedings after adjustment for confounders (β = -1.1, p = 0.03; and β = -0.002, p = 0.02, respectively). Nutritional intake was correlated with serum concentrations of GIP and PYY on postnatal day 7 and time to full enteral feedings. Mediation analysis revealed that the effect of serum gut hormone concentrations on time to full enteral feedings was not fully explained by nutritional intake. Intrauterine growth restriction (IUGR), mechanical ventilation on postnatal day 7, and patent ductus arteriosus (PDA) treated with indomethacin were associated with longer time to full enteral feedings. Serum concentrations of GIP and PYY on postnatal 7 are independently associated with time to full enteral feedings. The link between serum gut hormone concentrations and time to full enteral feedings is not fully mediated by nutritional factors, suggesting an independent mechanism underlying the influence of gut hormones on feeding tolerance and time to full enteral feedings.

Assessment of full-scale biological nutrient removal systems upgraded with physico-chemical processes for the removal of emerging pollutants present in wastewaters from Mexico.

PubMed

Estrada-Arriaga, Edson Baltazar; Cortés-Muñoz, Juana Enriqueta; González-Herrera, Arturo; Calderón-Mólgora, César Guillermo; de Lourdes Rivera-Huerta, Ma; Ramírez-Camperos, Esperanza; Montellano-Palacios, Leticia; Gelover-Santiago, Silvia Lucila; Pérez-Castrejón, Sara; Cardoso-Vigueros, Lina; Martín-Domínguez, Alejandra; García-Sánchez, Liliana

2016-11-15

Two full-scale biological nutrient removal systems upgraded with three physico-chemical processes (coagulation, chemical precipitation, and neutral Fenton) were evaluated in order to determine the removal of emerging pollutants (EPs) present in municipal wastewater from Mexico. Between 41 and 55 EPs were detected in the influents of two wastewater treatment plants (WWTPs), including personal care products (PPCPs), antibiotics, analgesics, antiepileptics, antilipidemics, antihypertensives, antiseptics, stimulants, and hormones. Emerging pollutants were detected at concentrations ranging from 0.69ng/L to 94,600ng/L. High concentrations of emerging pollutants were found during dry season. WWTP 1, integrated by oxidation ditches and UV light lamps, showed removal efficiencies of EPs between 20% and 22%. On the other hand, WWTP 2 consisted of anaerobic/anoxic/aerobic tanks coupled with two disinfection processes; chlorine dioxide and UV light lamps, for which the removal of EPs was significant (up to 80%). The concentrations of emerging pollutants in WWTP 1 effluent was found within a range

Fluorescence spectroscopy of Rhodamine 6G: concentration and solvent effects.

PubMed

Zehentbauer, Florian M; Moretto, Claudia; Stephen, Ryan; Thevar, Thangavel; Gilchrist, John R; Pokrajac, Dubravka; Richard, Katherine L; Kiefer, Johannes

2014-01-01

Rhodamine 6G (R6G), also known as Rhodamine 590, is one of the most frequently used dyes for application in dye lasers and as a fluorescence tracer, e.g., in the area of environmental hydraulics. Knowing the spectroscopic characteristics of the optical emission is key to obtaining high conversion efficiency and measurement accuracy, respectively. In this work, solvent and concentration effects are studied. A series of eight different organic solvents (methanol, ethanol, n-propanol, iso-propanol, n-butanol, n-pentanol, acetone, and dimethyl sulfoxide (DMSO)) are investigated at constant dye concentration. Relatively small changes of the fluorescence spectrum are observed for the different solvents; the highest fluorescence intensity is observed for methanol and lowest for DMSO. The shortest peak wavelength is found in methanol (568 nm) and the longest in DMSO (579 nm). Concentration effects in aqueous R6G solutions are studied over the full concentration range from the solubility limit to highly dilute states. Changing the dye concentration provides tunability between ∼550 nm in the dilute case and ∼620 nm at high concentration, at which point the fluorescence spectrum indicates the formation of R6G aggregates. Copyright © 2013 Elsevier B.V. All rights reserved.

Carbohydrate reserves in the facilitator cushion plant Laretia acaulis suggest carbon limitation at high elevation and no negative effects of beneficiary plants.

PubMed

García Lino, Mary Carolina; Cavieres, Lohengrin A; Zotz, Gerhard; Bader, Maaike Y

2017-04-01

The elevational range of the alpine cushion plant Laretia acaulis (Apiaceae) comprises a cold upper extreme and a dry lower extreme. For this species, we predict reduced growth and increased non-structural carbohydrate (NSC) concentrations (i.e. carbon sink limitation) at both elevational extremes. In a facilitative interaction, these cushions harbor other plant species (beneficiaries). Such interactions appear to reduce reproduction in other cushion species, but not in L. acaulis. However, vegetative effects may be more important in this long-lived species and may be stronger under marginal conditions. We studied growth and NSC concentrations in leaves and stems of L. acaulis collected from cushions along its full elevational range in the Andes of Central Chile. NSC concentrations were lowest and cushions were smaller and much less abundant at the highest elevation. At the lowest elevation, NSC concentrations and cushion sizes were similar to those of intermediate elevations but cushions were somewhat less abundant. NSC concentrations and growth did not change with beneficiary cover at any elevation. Lower NSC concentrations at the upper extreme contradict the sink-limitation hypothesis and may indicate that a lack of warmth is not limiting growth at high-elevation. At the lower extreme, carbon gain and growth do not appear more limiting than at intermediate elevations. The lower population density at both extremes suggests that the regeneration niche exerts important limitations to this species' distribution. The lack of an effect of beneficiaries on reproduction and vegetative performance suggests that the interaction between L. acaulis and its beneficiaries is probably commensalistic.

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

PubMed

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

2008-08-01

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

Working hours, work-life conflict and health in precarious and "permanent" employment.

PubMed

Bohle, Philip; Quinlan, Michael; Kennedy, David; Williamson, Ann

2004-12-01

The expansion of precarious employment in OECD countries has been widely associated with negative health and safety effects. Although many shiftworkers are precariously employed, shiftwork research has concentrated on full-time workers in continuing employment. This paper examines the impact of precarious employment on working hours, work-life conflict and health by comparing casual employees to full-time, "permanent" employees working in the same occupations and workplaces. Thirty-nine convergent interviews were conducted in two five-star hotels. The participants included 26 full-time and 13 casual (temporary) employees. They ranged in age from 19 to 61 years and included 17 females and 22 males. Working hours ranged from zero to 73 hours per week. Marked differences emerged between the reports of casual and full-time employees about working hours, work-life conflict and health. Casuals were more likely to work highly irregular hours over which they had little control. Their daily and weekly working hours ranged from very long to very short according to organisational requirements. Long working hours, combined with low predictability and control, produced greater disruption to family and social lives and poorer work-life balance for casuals. Uncoordinated hours across multiple jobs exacerbated these problems in some cases. Health-related issues reported to arise from work-life conflict included sleep disturbance, fatigue and disrupted exercise and dietary regimes. This study identified significant disadvantages of casual employment. In the same hotels, and doing largely the same jobs, casual employees had less desirable and predictable work schedules, greater work-life conflict and more associated health complaints than "permanent" workers.

Nitrifying bacterial biomass and nitrification activity evaluated by FISH and an automatic on-line instrument at full-scale Fusina (Venice, Italy) WWTP.

PubMed

Badoer, S; Miana, P; Della Sala, S; Marchiori, G; Tandoi, V; Di Pippo, F

2015-12-01

In this study, monthly variations in biomass of ammonia-oxidizing bacteria (AOB) and nitrite-oxidizing bacteria (NOB) were analysed over a 1-year period by fluorescence in situ hybridization (FISH) at the full-scale Fusina WWTP. The nitrification capacity of the plant was also monitored using periodic respirometric batch tests and by an automated on-line titrimetric instrument (TITrimetric Automated ANalyser). The percentage of nitrifying bacteria in the plant was the highest in summer and was in the range of 10-15 % of the active biomass. The maximum nitrosation rate varied in the range 2.0-4.0 mg NH4 g(-1) VSS h(-1) (0.048-0.096 kg TKN kg(-1) VSS day(-1)): values obtained by laboratory measurements and the on-line instrument were similar and significantly correlated. The activity measurements provided a valuable tool for estimating the maximum total Kjeldahl nitrogen (TKN) loading possible at the plant and provided an early warning of whether the TKN was approaching its limiting value. The FISH analysis permitted determination of the nitrifying biomass present. The main operational parameter affecting both the population dynamics and the maximum nitrosation activity was mixed liquor volatile suspended solids (MLVSS) concentration and was negatively correlated with ammonia-oxidizing bacteria (AOB) (p = 0.029) and (NOB) (p = 0.01) abundances and positively correlated with maximum nitrosation rates (p = 0.035). Increases in concentrations led to decreases in nitrifying bacteria abundance, but their nitrosation activity was higher. These results demonstrate the importance of MLVSS concentration as key factor in the development and activity of nitrifying communities in wastewater treatment plants (WWTPs). Operational data on VSS and sludge volume index (SVI) values are also presented on 11-year basis observations.

Bioaccumulation of metals by Fucus ceranoides in estuaries of South West England.

PubMed

Varma, Ranjit; Turner, Andrew; Brown, Murray T

2011-11-01

Fucus ceranoides tolerates abiotic conditions encountered across the full range of estuarine salinities. We examined the bioaccumulation of metals in individuals and metal concentrations in accompanying sediment samples collected at different locations along estuaries of South West England. Intra- and inter-estuarine variations in metal accumulation by F. ceranoides, after correction for particulate contamination using Fe as a proxy, were attributed to variations in the availabilities and concentrations of aqueous metals. Greatest accumulation was observed in estuaries that remain most heavily impacted by historical mining activities and for metals that were mobilised to the greatest extent during these operations (As, Cu, Sn, Zn). Arsenic concentrations displayed a seaward increase in estuaries in which multiple samples were taken, whereas Cd concentrations were always greatest in samples collected from the most landward locations. Ongoing research aims to better understand the mechanisms and kinetics of metal interactions with F. ceranoides and their dependence on salinity. Copyright © 2011 Elsevier Ltd. All rights reserved.

Dodine as a Protein Denaturant: The Best of Two Worlds?

PubMed Central

Gelman, Hannah; Perlova, Tatyana; Gruebele, Martin

2013-01-01

Traditional denaturants such as urea and guanidinium ion unfold proteins in a cooperative “all-or-none” fashion. However, their high working concentration in combination with their strong absorption in the far ultraviolet region make it impossible to measure high quality circular dichroism or infrared spectra, which are commonly used to detect changes in protein secondary structure. On the other hand, detergents such as dodecyl sulfate destabilize native protein conformation at low millimolar concentrations and are UV transparent, but they do denature proteins more gradually than guanidinium or urea. In this work we studied the denaturation properties of the fungicide dodecylguanidinium acetate (dodine), which combines both denaturants into one. We show that dodine unfolds some small proteins at millimolar concentrations, facilitates temperature denaturation, and is transparent enough at its working concentration, unlike guanidinium, to measure full range circular dichroism spectra. Our results also suggest that dodine allows fine-tuning of the protein’s unfolded state, unlike traditional “all-or-none” denaturants. PMID:23906507

Effect of enzyme concentration, addition of water and incubation time on increase in yield of starch from potato.

PubMed

Sit, Nandan; Agrawal, U S; Deka, Sankar C

2014-05-01

Enzymatic treatment process for starch extraction from potato was investigated using cellulase enzyme and compared with conventional process. The effects of three parameters, cellulase enzyme concentration, incubation time and addition of water were evaluated for increase in starch yield as compared to the conventional process i.e., without using enzyme. A two-level full factorial design was used to study the process. The results indicated that all the main parameters and their interactions are statistically significant. Enzyme concentration and incubation time had a positive effect on the increase in starch yield while addition of water had a negative effect. The increase in starch yield ranged from 1.9% at low enzyme concentration and incubation time and high addition of water to a maximum of 70% increase from conventional process in starch yield was achieved when enzyme concentration and incubation time were high and addition of water was low suggesting water present in the ground potato meal is sufficient for access to the enzyme with in the slurry ensuring adequate contact with the substrate.

Simulant Development for LAWPS Testing

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

Russell, Renee L.; Schonewill, Philip P.; Burns, Carolyn A.

2017-05-23

This report describes simulant development work that was conducted to support the technology maturation of the LAWPS facility. Desired simulant physical properties (density, viscosity, solids concentration, solid particle size), sodium concentrations, and general anion identifications were provided by WRPS. The simulant recipes, particularly a “nominal” 5.6M Na simulant, are intended to be tested at several scales, ranging from bench-scale (500 mL) to full-scale. Each simulant formulation was selected to be chemically representative of the waste streams anticipated to be fed to the LAWPS system, and used the current version of the LAWPS waste specification as a formulation basis. After simulantmore » development iterations, four simulants of varying sodium concentration (5.6M, 6.0M, 4.0M, and 8.0M) were prepared and characterized. The formulation basis, development testing, and final simulant recipes and characterization data for these four simulants are presented in this report.« less

Solar Thermal Concept Evaluation

NASA Technical Reports Server (NTRS)

Hawk, Clark W.; Bonometti, Joseph A.

1995-01-01

Concentrated solar thermal energy can be utilized in a variety of high temperature applications for both terrestrial and space environments. In each application, knowledge of the collector and absorber's heat exchange interaction is required. To understand this coupled mechanism, various concentrator types and geometries, as well as, their relationship to the physical absorber mechanics were investigated. To conduct experimental tests various parts of a 5,000 watt, thermal concentrator, facility were made and evaluated. This was in anticipation at a larger NASA facility proposed for construction. Although much of the work centered on solar thermal propulsion for an upper stage (less than one pound thrust range), the information generated and the facility's capabilities are applicable to material processing, power generation and similar uses. The numerical calculations used to design the laboratory mirror and the procedure for evaluating other solar collectors are presented here. The mirror design is based on a hexagonal faceted system, which uses a spherical approximation to the parabolic surface. The work began with a few two dimensional estimates and continued with a full, three dimensional, numerical algorithm written in FORTRAN code. This was compared to a full geometry, ray trace program, BEAM 4, which optimizes the curvatures, based on purely optical considerations. Founded on numerical results, the characteristics of a faceted concentrator were construed. The numerical methodologies themselves were evaluated and categorized. As a result, the three-dimensional FORTRAN code was the method chosen to construct the mirrors, due to its overall accuracy and superior results to the ray trace program. This information is being used to fabricate and subsequently, laser map the actual mirror surfaces. Evaluation of concentrator mirrors, thermal applications and scaling the results of the 10 foot diameter mirror to a much larger concentrator, were studied. Evaluations, recommendations and pit falls regarding the structure, materials and facility design are presented.

Interleukins in gingival crevicular fluid in patients with definitive full-coverage restorations.

PubMed

Chang, Kai-Chiao J; Wheater, Michelle A; Cabanilla Jacobs, Levyee; Litonjua, Luis A

2014-04-01

The objective of this study was to determine interleukin (IL)-1α and IL-8 levels in the gingival crevicular fluid (GCF) of patients with different levels of crown margin placements. Samples of GCF were obtained from 12 study participants with definitive full-coverage restorations with supragingival or equigingival crown margin placements. The periodontal status of the volunteers ranged from healthy to generalized severe periodontitis. Pocket depth and bleeding on probing were assessed at the clinical examination, and interleukin concentrations were determined by enzyme-linked immunosorbent assay (ELISA). Analysis of variance (ANOVA) was used to statistically compare interleukin concentrations between the control, supragingival, and equigingival GCF samples. Compared to controls (60.4 ± 8.9 pg/mL), the average IL-1α concentration in the GCF samples surrounding the supragingival margins was 53.8 ± 9.7 pg/mL and was 110.5 ± 23.3 pg/mL in the equigingival margins. Compared to controls (59.0 ± 14.1 pg/mL), the average IL-8 concentration in the supragingival margins was 46.9 ± 9.7 pg/mL and was 131.4 ± 27.5 pg/mL in the equigingival margins. The trend of higher levels of interleukins in GCF corresponding to equigingival margins was consistent, as was the trend of lower concentrations in supragingival margins compared to the controls; however, statistical significance was not achieved because of the wide biological variation within and between patients. In conclusion, differences in GCF IL-1α and IL-8 concentrations were observed when comparing fixed crown restorations with equigingival and supragingival margins. Gingival inflammation may be dependent on the periodontal condition in addition to restoration or margin placement.

Sludge dewatering and stabilization in drying reed beds: characterization of three full-scale systems in Catalonia, Spain.

PubMed

Uggetti, Enrica; Llorens, Esther; Pedescoll, Anna; Ferrer, Ivet; Castellnou, Roger; García, Joan

2009-09-01

Optimization of sludge management can help reducing sludge handling costs in wastewater treatment plants. Sludge drying reed beds appear as a new and alternative technology which has low energy requirements, reduced operating and maintenance costs, and causes little environmental impact. The objective of this work was to evaluate the efficiency of three full-scale drying reed beds in terms of sludge dewatering, stabilization and hygienisation. Samples of influent sludge and sludge accumulated in the reed beds were analysed for pH, Electrical Conductivity, Total Solids (TS), Volatile Solids (VS), Chemical Oxygen Demand, Biochemical Oxygen Demand, nutrients (Total Kjeldahl Nitrogen (TKN) and Total Phosphorus (TP)), heavy metals and faecal bacteria indicators (Escherichiacoli and Salmonella spp.). Lixiviate samples were also collected. There was a systematic increase in the TS concentration from 1-3% in the influent to 20-30% in the beds, which fits in the range obtained with conventional dewatering technologies. Progressive organic matter removal and sludge stabilization in the beds was also observed (VS concentration decreased from 52-67% TS in the influent to 31-49% TS in the beds). Concentration of nutrients of the sludge accumulated in the beds was quite low (TKN 2-7% TS and TP 0.04-0.7% TS), and heavy metals remained below law threshold concentrations. Salmonella spp. was not detected in any of the samples, while E. coli concentration was generally lower than 460MPN/g in the sludge accumulated in the beds. The studied systems demonstrated a good efficiency for sludge dewatering and stabilization in the context of small remote wastewater treatment plants.

Application of Liquid Chromatography-Tandem Mass Spectrometry To Determine Urinary Concentrations of Five Commonly Used Low-Calorie Sweeteners: A Novel Biomarker Approach for Assessing Recent Intakes?

PubMed

Logue, Caomhan; Dowey, Le Roy C; Strain, J J; Verhagen, Hans; McClean, Stephen; Gallagher, Alison M

2017-06-07

Although the use of low-calorie sweeteners (LCSs) is widespread, methods of assessing consumption within free-living populations have inherent limitations. Five commonly consumed LCSs, namely, acesulfame-K, saccharin, sucralose, cyclamate, and steviol glycosides, are excreted via the urine, and therefore a urinary biomarker approach may provide more objective LCS intake data. A LC-ESI-MS/MS method of simultaneously determining acesulfame-K, saccharin, sucralose, cyclamate, and the excretory metabolite of steviol glycosides, steviol glucuronide, in human urine was developed and validated. Linearity was observed over a concentration range of 10-1000 ng/mL with coefficients of determination ranging from 0.9969 to 0.9997. Accuracy ranged from 92 to 104%, and intrabatch and interday precisions were within acceptable limits with %CV below 8% for all compounds. A double-blind, randomized crossover dose-response study was conducted to assess the usefulness of urinary LCS excretions (from both fasting spot and a full 24-h urine collection) for investigating recent intakes. Both modes of sampling were useful for distinguishing between the three short-term intakes of acesulfame-K, saccharin, cyclamates, and steviol glycosides (p < 0.001), whereas for sucralose, urinary concentrations were useful for distinguishing between low (0.1% ADI) and high doses (10% ADI) only (p < 0.001). In summary, this biomarker approach may be useful for assessing intakes of five commonly consumed LCSs.

Evaluation of exposures to fluorocarbon 113 in a horizontal and a vertical laminar airflow clean room.

PubMed

Bloom, T F; Egeland, G M

1999-01-01

Exposures to 1,1,2-trichloro-1,2,2-trifluoroethane or fluorocarbon (FC) 113 were evaluated in a horizontal laminar airflow (HLAF) clean room and a vertical laminar airflow (VLAF) clean room. A full period consecutive samples measurement strategy was employed. Data were used to calculate 8-hour time-weighted averages (8-TWA) for major work groups and to characterize exposures associated with specific cleaning tasks. The MIRAN 1B infrared analyzer was used to estimate peak concentrations. In the HLAF clean room, 8-TWAs ranged from 193 to 439 ppm; in the VLAF clean room, 8-TWAs ranged from 110 to 935 ppm. These levels were below the current Occupational Safety and Health Administration permissible exposure limit and the National Institute for Occupational Safety and Health (NIOSH) recommended exposure limit for FC 113 of 1000 ppm. Short-term sample concentrations ranged from 104 ppm (inspection) to 1080 ppm (assembly) in the HLAF clean room and 51 ppm (packaging)-3380 ppm (flushing) in the VLAF clean room. In the VLAF clean room, several short-term concentrations measured during the flushing task--1421 ppm and 2522 ppm--were above the NIOSH short-term exposure limit (STEL) of 1250 ppm. These data suggest the possibility that the STEL may be exceeded for tasks involving direct work with liquid FC 113. Peak exposure levels may be reduced by modification of worker position in the HLAF clean room and by use of open wire tables in the VLAF clean room.

Modelling compressible dense and dilute two-phase flows

NASA Astrophysics Data System (ADS)

Saurel, Richard; Chinnayya, Ashwin; Carmouze, Quentin

2017-06-01

Many two-phase flow situations, from engineering science to astrophysics, deal with transition from dense (high concentration of the condensed phase) to dilute concentration (low concentration of the same phase), covering the entire range of volume fractions. Some models are now well accepted at the two limits, but none are able to cover accurately the entire range, in particular regarding waves propagation. In the present work, an alternative to the Baer and Nunziato (BN) model [Baer, M. R. and Nunziato, J. W., "A two-phase mixture theory for the deflagration-to-detonation transition (DDT) in reactive granular materials," Int. J. Multiphase Flow 12(6), 861 (1986)], initially designed for dense flows, is built. The corresponding model is hyperbolic and thermodynamically consistent. Contrarily to the BN model that involves 6 wave speeds, the new formulation involves 4 waves only, in agreement with the Marble model [Marble, F. E., "Dynamics of a gas containing small solid particles," Combustion and Propulsion (5th AGARD Colloquium) (Pergamon Press, 1963), Vol. 175] based on pressureless Euler equations for the dispersed phase, a well-accepted model for low particle volume concentrations. In the new model, the presence of pressure in the momentum equation of the particles and consideration of volume fractions in the two phases render the model valid for large particle concentrations. A symmetric version of the new model is derived as well for liquids containing gas bubbles. This model version involves 4 characteristic wave speeds as well, but with different velocities. Last, the two sub-models with 4 waves are combined in a unique formulation, valid for the full range of volume fractions. It involves the same 6 wave speeds as the BN model, but at a given point of space, 4 waves only emerge, depending on the local volume fractions. The non-linear pressure waves propagate only in the phase with dominant volume fraction. The new model is tested numerically on various test problems ranging from separated phases in a shock tube to shock-particle cloud interaction. Its predictions are compared to BN and Marble models as well as against experimental data showing clear improvements.

Molecular Dynamics Analysis of Lysozyme Protein in Ethanol-Water Mixed Solvent Environment

NASA Astrophysics Data System (ADS)

Ochije, Henry Ikechukwu

Effect of protein-solvent interaction on the protein structure is widely studied using both experimental and computational techniques. Despite such extensive studies molecular level understanding of proteins and some simple solvents is still not fully understood. This work focuses on detailed molecular dynamics simulations to study of solvent effect on lysozyme protein, using water, alcohol and different concentrations of water-alcohol mixtures as solvents. The lysozyme protein structure in water, alcohol and alcohol-water mixture (0-12% alcohol) was studied using GROMACS molecular dynamics simulation code. Compared to water environment, the lysozome structure showed remarkable changes in solvents with increasing alcohol concentration. In particular, significant changes were observed in the protein secondary structure involving alpha helices. The influence of alcohol on the lysozyme protein was investigated by studying thermodynamic and structural properties. With increasing ethanol concentration we observed a systematic increase in total energy, enthalpy, root mean square deviation (RMSD), and radius of gyration. a polynomial interpolation approach. Using the resulting polynomial equation, we could determine above quantities for any intermediate alcohol percentage. In order to validate this approach, we selected an intermediate ethanol percentage and carried out full MD simulation. The results from MD simulation were in reasonably good agreement with that obtained using polynomial approach. Hence, the polynomial approach based method proposed here eliminates the need for computationally intensive full MD analysis for the concentrations within the range (0-12%) studied in this work.

A novel hydrogel based piezoresistive pressure sensor platform for chemical sensing

NASA Astrophysics Data System (ADS)

Orthner, Michael P.

New hydrogel-based micropressure sensor arrays for use in the fields of chemical sensing, physiological monitoring, and medical diagnostics are developed and demonstrated. This sensor technology provides reliable, linear, and accurate measurements of hydrogel swelling pressures, a function of ambient chemical concentrations. For the first time, perforations were implemented into the pressure sensors piezoresistive diaphragms, used to simultaneously increase sensor sensitivity and permit diffusion of analytes into the hydrogel cavity. It was shown through analytical and numerical (finite element) methods that pore shape, location, and size can be used to modify the diaphragm mechanics and concentrate stress within the piezoresistors, thus improving electrical output (sensitivity). An optimized pore pattern was chosen based on these numerical calculations. Fabrication was performed using a 14-step semiconductor fabrication process implementing a combination of potassium hydroxide (KOH) and deep reactive ion etching (DRIE) to create perforations. The sensor arrays (2x2) measure approximately 3 x 5 mm2 and used to measure full scale pressures of 50, 25, and 5 kPa, respectively. These specifications were defined by the various swelling pressures of ionic strength, pH and glucose specific hydrogels that were targeted in this work. Initial characterization of the sensor arrays was performed using a custom built bulge testing apparatus that simultaneously measured deflection (optical profilometry), pressure, and electrical output. The new perforated diaphragm sensors were found to be fully functional with sensitivities ranging from 23 to 252 muV/V-kPa with full scale output (FSO) ranging from 5 to 80 mV. To demonstrate proof of concept, hydrogels sensitive to changes in ionic strength were synthesized using hydroxypropyl-methacrylate (HPMA), N,N-dimethylaminoethyl-methacrylate (DMA) and a tetra-ethyleneglycol-dimethacrylate (TEGDMA) crosslinker. This hydrogel quickly and reversibly swells when placed environments of physiological buffer solutions (PBS) with ionic strengths ranging from 0.025 to 0.15 M. Chemical testing showed sensors with perforated diaphragms have higher sensitivity than those with solid diaphragms, and sensitivities ranging from 53.3+/-6.5 to 271.47+/-27.53 mV/V-M, depending on diaphragm size. Additionally, recent experiments show sensors utilizing Ultra Violet (UV) polymerized glucose sensitive hydrogels respond reversibly to physiologically relevant glucose concentrations from 0 to 20 mM.

Physiological changes in largemouth bass exposed to paper mill effluents under laboratory and field conditions

USGS Publications Warehouse

Sepulveda, M.S.; Gallagher, E.P.; Gross, T.S.

2004-01-01

We report here on studies designed to asses the effects of paper mill effluents on non-reproductive functions of free-ranging and captive Florida largemouth bass (Micropterus salmoides floridanus) This was accomplished by conducting an outdoor tank study, in which fish were exposed to well water or to 10%, 20%, 40%, and 80% full strength effluent for 28 or 56 days, and by sampling largemouth bass from sites within the St. Johns River, Florida, upstream and downstream from a paper mill plant. Blood and plasma samples from fish from the tank study and from fish sampled from the ambient sites were analyzed for over 20 variables. We also determined liver and spleen weights and examined them histologically. The most significant finding from the tank study was an increase in the concentration of albumin and hepatosomatic index for bass exposed to ???20% effluents for 56 days. Spleenosomatic index and number of melanomacrophage centers were decreased in bass from effluent-dominated sites (Palatka and Rice Creek), whereas concentrations of calcium, phosphorous, glucose, and creatinine were elevated in fish from these sites, compared to fish from reference streams. Fish from Rice Creek also had fewer red blood cells, and male bass from Palatka had lower concentrations of cholesterol. Plasma concentrations of albumin and hepatic concentrations of glutathione were elevated in males from Palatka, and both females and males from Rice Creek had higher concentrations of globulin. These results indicate a complex pattern of effects of paper mill effluents on several physiological functions. However, despite the myriad of treatment and site-related effects, most physiological parameters fell within normal ranges when compared to reports on largemouth bass and other freshwater species.

Change in Dielectric Properties in the Microwave Frequency Region of Polypyrrole–Coated Textiles during Aging

PubMed Central

Hakansson, Eva; Kaynak, Akif; Kouzani, Abbas

2016-01-01

Complex permittivity of conducting polypyrrole (PPy)-coated Nylon-Lycra textiles is measured using a free space transmission measurement technique over the frequency range of 1–18 GHz. The aging of microwave dielectric properties and reflection, transmission and absorption for a period of 18 months is demonstrated. PPy-coated fabrics are shown to be lossy over the full frequency range. The levels of absorption are shown to be higher than reflection in the tested samples. This is attributed to the relatively high resistivity of the PPy-coated fabrics. Both the dopant concentration and polymerisation time affect the total shielding effectiveness and microwave aging behaviour. Distinguishing either of these two factors as being exclusively the dominant mechanism of shielding effectiveness is shown to be difficult. It is observed that the PPy-coated Nylon-Lycra samples with a p-toluene sulfonic acid (pTSA) concentration of 0.015 M and polymerisation times of 60 min and 180 min have 37% and 26% decrease in total transmission loss, respectively, upon aging for 72 weeks at room temperature (20 °C, 65% Relative humidity (RH)). The concentration of the dopant also influences the microwave aging behaviour of the PPy-coated fabrics. The samples with a higher dopant concentration of 0.027 mol/L pTSA are shown to have a transmission loss of 32.6% and 16.5% for short and long polymerisation times, respectively, when aged for 72 weeks. The microwave properties exhibit better stability with high dopant concentration and/or longer polymerization times. High pTSA dopant concentrations and/or longer polymerisation times result in high microwave insertion loss and are more effective in reducing the transmission and also increasing the longevity of the electrical properties. PMID:28773729

Change in Dielectric Properties in the Microwave Frequency Region of Polypyrrole-Coated Textiles during Aging.

PubMed

Hakansson, Eva; Kaynak, Akif; Kouzani, Abbas

2016-07-22

Complex permittivity of conducting polypyrrole (PPy)-coated Nylon-Lycra textiles is measured using a free space transmission measurement technique over the frequency range of 1-18 GHz. The aging of microwave dielectric properties and reflection, transmission and absorption for a period of 18 months is demonstrated. PPy-coated fabrics are shown to be lossy over the full frequency range. The levels of absorption are shown to be higher than reflection in the tested samples. This is attributed to the relatively high resistivity of the PPy-coated fabrics. Both the dopant concentration and polymerisation time affect the total shielding effectiveness and microwave aging behaviour. Distinguishing either of these two factors as being exclusively the dominant mechanism of shielding effectiveness is shown to be difficult. It is observed that the PPy-coated Nylon-Lycra samples with a p -toluene sulfonic acid ( p TSA) concentration of 0.015 M and polymerisation times of 60 min and 180 min have 37% and 26% decrease in total transmission loss, respectively, upon aging for 72 weeks at room temperature (20 °C, 65% Relative humidity (RH)). The concentration of the dopant also influences the microwave aging behaviour of the PPy-coated fabrics. The samples with a higher dopant concentration of 0.027 mol/L p TSA are shown to have a transmission loss of 32.6% and 16.5% for short and long polymerisation times, respectively, when aged for 72 weeks. The microwave properties exhibit better stability with high dopant concentration and/or longer polymerization times. High p TSA dopant concentrations and/or longer polymerisation times result in high microwave insertion loss and are more effective in reducing the transmission and also increasing the longevity of the electrical properties.

From Solvent-Free to Dilute Electrolytes: Essential Components for a Continuum Theory.

PubMed

Gavish, Nir; Elad, Doron; Yochelis, Arik

2018-01-04

The increasing number of experimental observations on highly concentrated electrolytes and ionic liquids show qualitative features that are distinct from dilute or moderately concentrated electrolytes, such as self-assembly, multiple-time relaxation, and underscreening, which all impact the emergence of fluid/solid interfaces, and the transport in these systems. Because these phenomena are not captured by existing mean-field models of electrolytes, there is a paramount need for a continuum framework for highly concentrated electrolytes and ionic liquid mixtures. In this work, we present a self-consistent spatiotemporal framework for a ternary composition that comprises ions and solvent employing a free energy that consists of short- and long-range interactions, along with an energy dissipation mechanism obtained by Onsager's relations. We show that the model can describe multiple bulk and interfacial morphologies at steady-state. Thus, the dynamic processes in the emergence of distinct morphologies become equally as important as the interactions that are specified by the free energy. The model equations not only provide insights into transport mechanisms beyond the Stokes-Einstein-Smoluchowski relations but also enable qualitative recovery of three distinct regions in the full range of the nonmonotonic electrical screening length that has been recently observed in experiments in which organic solvent is used to dilute ionic liquids.

Characterizing temporal changes of agricultural particulate matter number concentrations

NASA Astrophysics Data System (ADS)

Docekal, G. P.; Mahmood, R.; Larkin, G. P.; Silva, P. J.

2017-12-01

It is widely accepted among literature that particulate matter (PM) are of detriment to human health and the environment as a whole. These effects can vary depending on the particle size. This study examines PM size distributions and number concentrations at a poultry house. Despite much literature on PM concentrations at agricultural facilities, few studies have looked at the size distribution of particles at such facilities from the nucleation up through the coarse mode. Two optical particle counters (OPCs) were placed, one inside of a chicken house, and one on the outside of an exhaust fan to determine particle size distributions. In addition, a scanning mobility particle sizer (SMPS) and aerodynamic particle sizer (APS) sampled poultry house particles to give sizing information from a full size range of 10 nm - 20 mm. The data collected show several different types of events where observed size distributions changed. While some of these are due to expected dust generation events producing coarse mode particles, others suggest particle nucleation and accumulation events at the smaller size ranges that also occurred. The data suggest that agricultural facilities have an impact one the presence of PM in the environment beyond just generation of coarse mode dust. Data for different types of size distribution changes observed will be discussed.

Sulfates as chromophores for multiwavelength photoacoustic imaging phantoms

NASA Astrophysics Data System (ADS)

Fonseca, Martina; An, Lu; Beard, Paul; Cox, Ben

2017-12-01

As multiwavelength photoacoustic imaging becomes increasingly widely used to obtain quantitative estimates, the need for validation studies conducted on well-characterized experimental phantoms becomes ever more pressing. One challenge that such studies face is the design of stable, well-characterized phantoms and absorbers with properties in a physiologically realistic range. This paper performs a full experimental characterization of aqueous solutions of copper and nickel sulfate, whose properties make them close to ideal as chromophores in multiwavelength photoacoustic imaging phantoms. Their absorption varies linearly with concentration, and they mix linearly. The concentrations needed to yield absorption values within the physiological range are below the saturation limit. The shape of their absorption spectra makes them useful analogs for oxy- and deoxyhemoglobin. They display long-term photostability (no indication of bleaching) as well as resistance to transient effects (no saturable absorption phenomena), and are therefore suitable for exposure to typical pulsed photoacoustic light sources, even when exposed to the high number of pulses required in scanning photoacoustic imaging systems. In addition, solutions with tissue-realistic, predictable, and stable scattering can be prepared by mixing sulfates and Intralipid, as long as an appropriate emulsifier is used. Finally, the Grüneisen parameter of the sulfates was found to be larger than that of water and increased linearly with concentration.

Carbonaceous aerosols from prescribed burning of a boreal forest ecosystem. Revision

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

Mazurek, M.A.; Cofer, W.R. III; Levine, J.S.

1990-10-01

The identity and ambient mass concentrations of radiatively important carbonaceous aerosols were measured for a boreal forest prescribed burn conducted in northern Ontario, CAN in August 1989. Nonsize-segregated airborne particles were collected for smoldering-fire and full-fire conditions using a helicopter sampling platform. Total carbon (TC), organic carbon (OC) and elemental carbon (EC) were measured. Smoke plume mass concentrations of the OC and EC particles were greatest for full-fire conditions and had ranges of 1.560 to 2.160 mg/m{sup {minus}1} (OC) and 0.120 to 0.160 mg/m{sup {minus}3} (EC) with OC:EC ratios of 10 to 18, respectively. Smoldering fire conditions showed smoke plumemore » OC and EC levels of 0.570--1.030 mg/m{sup {minus}3} (OC) and 0.006--0.050 mg/m{sup {minus}3} (EC) and much higher ratios of OC:EC (21 to 95). These aerosol data indicate the formation of EC particles is greatest during full-fire combustion of boreal forest material relative to smoldering combustion. However, EC particles comprise a minor fraction of the particulate carbon smoke aerosols for both full-fire and smoldering conditions; the major component of carbonaceous smoke aerosols emitted during the prescribed burn is OC. Overall, the OC and EC in-plume smoke aerosol data show nonuniform production of these particles during various stages of the prescribed burn, and major differences in the type of carbonaceous aerosol that is generated (OC versus EC).« less

Carbonaceous aerosols from prescribed burning of a boreal forest ecosystem

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

Mazurek, M.A.; Cofer, W.R. III; Levine, J.S.

1990-10-01

The identity and ambient mass concentrations of radiatively important carbonaceous aerosols were measured for a boreal forest prescribed burn conducted in northern Ontario, CAN in August 1989. Nonsize-segregated airborne particles were collected for smoldering-fire and full-fire conditions using a helicopter sampling platform. Total carbon (TC), organic carbon (OC) and elemental carbon (EC) were measured. Smoke plume mass concentrations of the OC and EC particles were greatest for full-fire conditions and had ranges of 1.560 to 2.160 mg/m{sup {minus}1} (OC) and 0.120 to 0.160 mg/m{sup {minus}3} (EC) with OC:EC ratios of 10 to 18, respectively. Smoldering fire conditions showed smoke plumemore » OC and EC levels of 0.570--1.030 mg/m{sup {minus}3} (OC) and 0.006--0.050 mg/m{sup {minus}3} (EC) and much higher ratios of OC:EC (21 to 95). These aerosol data indicate the formation of EC particles is greatest during full-fire combustion of boreal forest material relative to smoldering combustion. However, EC particles comprise a minor fraction of the particulate carbon smoke aerosols for both full-fire and smoldering conditions; the major component of carbonaceous smoke aerosols emitted during the prescribed burn is OC. Overall, the OC and EC in-plume smoke aerosol data show nonuniform production of these particles during various stages of the prescribed burn, and major differences in the type of carbonaceous aerosol that is generated (OC versus EC).« less

Study on superconducting state parameters of Cu1-xZrx metallic glasses using model potentials

NASA Astrophysics Data System (ADS)

Jambusarwala, Tasneem S.; Gajjar, P. N.

2018-05-01

The superconducting state parameters (SSP) of Cu1-xZrx metallic glasses over the full range of concentration x of Zr have been investigated to study influence of various local pseudopotentials. The study includes the computation of electron-phonon coupling strength (λ), transition temperature (TC), isotope effect exponent (α) and effective interaction strength (N0V) using fourteen different forms of local model potentials. The local field correction function proposed by Taylor (T) is used. The influence of model potential on various parameters is ranging from 6% to 83% for pure Zr and 28% to 84% for pure Cu. The present study confirms that the identification of model potential is vital in studying Superconducting State Parameters.

Can we reduce the number of fish in the OECD acute toxicity test?

PubMed

Rufli, Hans; Springer, Timothy A

2011-04-01

OECD (Organisation for Economic Co-operation and Development) Guideline 203, Fish Acute Toxicity Test, states that the test should be performed using at least five concentrations in a geometric series with a separation factor not exceeding 2.2, with at least seven fish per concentration. However, the efficiency of this design can be questioned, because it often results in only one concentration that causes partial mortality (mortality >0% and <100%). We performed Monte Carlo computer simulations to assess whether more efficient designs could allow reductions in fish use. Simulations indicated that testing with six fish per concentration could yield 50% lethal concentration (LC50) estimates of quality similar to those obtained using seven fish. Experts attending a workshop organized to consider this finding and to identify the best methods for reducing fish use concluded that significant reductions could best be achieved by modifying the test paradigm. They suggested initiating testing using a 96-h fish embryo test instead of juvenile fish to cover the range from the upper threshold concentration (the lowest 50% effective concentration [EC50] in existing algae and daphnia studies) to the highest concentration with no mortality. This would be followed by a confirmatory limit test with juvenile fish at the highest concentration with no mortality or by a full test with juvenile fish, if a point estimate of the LC50 is required. Copyright © 2011 SETAC.

Extending the turbidity record: making additional use of continuous data from turbidity, acoustic-Doppler, and laser diffraction instruments and suspended-sediment samples in the Colorado River in Grand Canyon

USGS Publications Warehouse

Voichick, Nicholas; Topping, David J.

2014-01-01

Turbidity is a measure of the scattering and absorption of light in water, which in rivers is primarily caused by particles, usually sediment, suspended in the water. Turbidity varies significantly with differences in the design of the instrument measuring turbidity, a point that is illustrated in this study by side-by-side comparisons of two different models of instruments. Turbidity also varies with changes in the physical parameters of the particles in the water, such as concentration, grain size, grain shape, and color. A turbidity instrument that is commonly used for continuous monitoring of rivers has a light source in the near-infrared range (860±30 nanometers) and a detector oriented 90 degrees from the incident light path. This type of optical turbidity instrument has a limited measurement range (depending on pathlength) that is unable to capture the high turbidity levels of rivers that carry high suspended-sediment loads. The Colorado River in Grand Canyon is one such river, in which approximately 60 percent of the range in suspended-sediment concentration during the study period had unmeasurable turbidity using this type of optical instrument. Although some optical turbidimeters using backscatter or other techniques can measure higher concentrations of suspended sediment than the models used in this study, the maximum turbidity measurable using these other turbidimeters may still be exceeded in conditions of especially high concentrations of suspended silt and clay. In Grand Canyon, the existing optical turbidity instruments remain in use in part to provide consistency over time as new techniques are investigated. As a result, during these periods of high suspended-sediment concentration, turbidity values that could not be measured with the optical turbidity instruments were instead estimated from concurrent acoustic attenuation data collected using side-looking acoustic-Doppler profiler (ADP) instruments. Extending the turbidity record to the full range of sediment concentrations in the study area using data from the ADP instruments is particularly useful for biological studies. In Grand Canyon, turbidity has been correlated with food availability for aquatic organisms (gross primary production) as well as with fish behavior specific to predator-prey interactions. On the basis of the complete “extended” turbidity record and the relation between suspended-sediment concentration and turbidity, levels were higher before the construction of Glen Canyon Dam by a factor of approximately 2,000 at the Lees Ferry monitoring station (15 miles downstream from the dam) and by a factor of approximately 20 at the monitoring station 87 miles downstream from Lees Ferry (102 miles downstream from the dam). A comparison of turbidity data with data from Laser In-Situ Scattering and Transmissometry (LISST) laser-diffraction instruments, suspended-sediment concentration data, and ADP data shows the influence of the physical properties of suspended sediment. Apparent outliers in relations between turbidity, ADP, and suspended-sediment data during two events within the study period, a 2007 tributary flood from a watershed altered by a recent wildfire and a 2008 experimental controlled-flood release from Glen Canyon Dam, are explained in part by atypical grain sizes, shapes, densities, colors, and (or) clay mineral assemblages of suspended sediment occurring in the Colorado River during these two events. These analyses demonstrate the value of using multiple data-collection strategies for turbidity and sediment-transport studies and of continuous monitoring for capturing the full range and duration of turbidity and sediment-transport conditions, identifying the provenance of the sediment causing turbidity, and detecting physical and chemical processes that may be important for management of critical physical and biological resources.

Interpretation of HbA1c : association with mean cell volume and haemoglobin concentration.

PubMed

Simmons, D; Hlaing, T

2014-11-01

The utility of HbA1c in diabetes diagnosis is reduced in settings associated with altered haemoglobin glycation. We have studied whether HbA1c varies with mean cell volume and mean cell haemoglobin concentration as measures of haemoglobin metabolism. Randomly selected adults from rural Victoria, Australia, were invited for biomedical assessment. After excluding patients with known diabetes and/or serum creatinine ≥ 0.12 mmol/l, 1315 adults were included. Demography, arthropometric measurements, oral glucose tolerance test, analyses of full blood count and HbA1c were undertaken. After adjusting for age, sex, ethnicity, BMI, town and socio-economic status, there were no significant differences in haemoglobin, mean cell volume or mean cell haemoglobin concentration by glycaemic status (defined by oral glucose tolerance test). HbA1c was significantly and independently associated with fasting glucose, town, mean cell haemoglobin concentration, ethnicity, age and BMI among men < 50 years (R² = 33.8%); fasting glucose, 2-h glucose, mean cell haemoglobin concentration and town among men ≥ 50 years (R² = 47.9%); fasting glucose, mean cell volume, mean cell haemoglobin concentration, town, 2-h glucose and age among women < 50 years (R² = 46.3%); fasting glucose, mean cell haemoglobin concentration, mean cell volume and 2-h glucose among women ≥ 50 years (R² = 51.6%). A generalized linear model showed a gradient from an adjusted mean HbA1c of 36 (95% CI 34-38) mmol/mol with a mean cell haemoglobin concentration of ≤ 320 g/l to 30 (95% CI 29-31) mmol/mol with a mean cell haemoglobin concentration of > 370 g/l. The gradient across mean cell volume was negative, but only by 1 mmol/mol (0.1%) HbA1c . A mean HbA1c difference of 5 mmol/mol (0.5%) across the mean cell haemoglobin concentration reference range suggests that an accompanying full blood count examination may be required for its use in the diagnosis of diabetes. Further studies are required to confirm this. © 2014 The Authors. Diabetic Medicine © 2014 Diabetes UK.

Survey of minerals and fat-soluble vitamins in captive black and white ruffed lemurs (Varecia variegata).

PubMed

Crawford, Graham C; Puschner, Birgit; Dierenfeld, Ellen S; Dunker, Freeland

2009-12-01

Serum and whole blood samples from 64 clinically normal captive black and white ruffed lemurs (Varecia variegata), aged 6 mo to 32 yr, were analyzed to survey mineral and fat-soluble vitamin concentrations. All animals were fed a commercial primate food and a wide range of fruits and vegetables. Specific commercial diet information was available for 52 animals that were fed one of 10 different diets. Data analysis showed no differences in the analytes attributable to sex or access to natural ultraviolet light. Serum phosphorus (range: 1.4-3.1 mmol/L) was significantly higher and retinol (range: 0.38-1.23 micromol/L) was significantly lower in young animals (< or =4 yr). Iron (range: 17.2-77.0 micromol/L) and copper (range: 10.7-53.3 micromol/L) were much higher than concentrations reported in other free-ranging lemur species, and in some animals were at levels considered potentially toxic in domestic animals. Magnesium (range: 0.66-2.04 mmol/L), sodium (range: 111-201 mmol/L), and potassium (range: 2.0-6.8 mmol/L) ranged both lower and higher than concentrations considered adequate for a mammal, but were similar to concentrations reported in wild red ruffed lemurs (Varecia rubra), a closely related species. Selenium (range: 3.5-7.7 micromol/L) was within the range expected for a mammal, but higher than concentrations reported in wild V rubra. Zinc (range: 9.2-62.7 micromol/L) was similar to concentrations reported in V. rubra. Calcidiol (range: <12.5-144.8 nmol/L) and retinol (range: 0.38-2.95 micromol/L) were both lower and higher than concentrations reported in V. rubra. Lower serum calcidiol concentration correlated with lower commercial dietary vitamin D3. Alpha-tocopherol (range: 1.2-17.6 micromol/L) and y-tocopherol (range: 0.3-3.9 micromol/L) were within a range expected in a captive frugivorous primate but higher than concentrations found in wild V. rubra.

The Influence of Sugar Cane Bagasse Type and Its Particle Size on Xylose Production and Xylose-to-Xylitol Bioconversion with the Yeast Debaryomyces hansenii.

PubMed

Aghcheh, Razieh Karimi; Bonakdarpour, Babak; Ashtiani, Farzin Zokaee

2016-11-01

In the present study, the effect of the type of sugar cane bagasse (non-depithed or depithed) and its particle size on the production of xylose and its subsequent fermentation to xylitol by Debaryomyces hansenii CBS767 was investigated using a full factorial experimental design. It was found that the particle size range and whether bagasse was depithed or not had a significant effect on the concentration and yield of xylose in the resulting hemicellulose hydrolysate. Depithed bagasse resulted in higher xylose concentrations compared to non-depithed bagasse. The corresponding detoxified hemicellulose hydrolysates were used as fermentation media for the production of xylitol. The hemicellulose hydrolysate prepared from depithed bagasse also yielded meaningfully higher xylitol fermentation rates compared to non-depithed bagasse. However, in the case of non-depithed bagasse, the hemicellulose hydrolysate prepared from larger particle size range resulted in higher xylitol fermentation rates, whereas the effect in the case of non-depithed bagasse was not pronounced. Therefore, depithing of bagasse is an advantageous pretreatment when it is to be employed in bioconversion processes.

Multi-scale structures and functional properties of starches from Indica hybrid, Japonica and waxy rice.

PubMed

Wang, Shujun; Li, Peiyan; Yu, Jinglin; Guo, Peng; Wang, Shuo

2017-09-01

The structural and functional properties of starches from three rice grains differing in amylose content (19.9, 13.4 and 0.8% for Japonica, Indica hybrid and waxy rice, respectively) were investigated using a range of characterization methods Indica hybrid starch (IHS) had the highest proportion of intermediate (DP 13-24) and long branch chains (DP≥37) and the lowest proportion of short branch chains (DP 6-12), whereas the opposite results were observed for Japonica starch (JS). The results for waxy rice starch (WS) were between those of IHS and JS. Rice starches showed a typical A-type X-ray diffraction pattern with the relative crystallinity ranging from 33.4% for JS to 39.4% for WS. Significant differences were observed in lamellar distance and short-range molecular order characterized by IR ratio of absorbances at 1047/1022cm -1 and full width of half maximum (FWHM) of the band at 480cm -1 . WS showed a higher swelling power and a lower close packing concentration at temperatures from 60 to 90°C. The lower peak viscosity of WS was attributed to the formation of less rigid swollen granules at a concentrated regime. WS showed a higher in vitro digestibility compared with IHS and JS. Copyright © 2017 Elsevier B.V. All rights reserved.

Tetrodotoxin Concentrations in Pleurobranchaea maculata: Temporal, Spatial and Individual Variability from New Zealand Populations

PubMed Central

Wood, Susanna A.; Taylor, David I.; McNabb, Paul; Walker, Jarrod; Adamson, Janet; Cary, Stephen Craig

2012-01-01

Tetrodotoxin (TTX) is a potent neurotoxin that has been identified in a range of phylogenetically unrelated marine and terrestrial organisms. Tetrodotoxin was recently detected in New Zealand in Pleurobranchaea maculata (the grey side-gilled sea slug). From June 2010 to June 2011 wild specimens were collected from 10 locations around New Zealand. At one site (Narrow Neck Beach, Auckland) up to 10 individuals were collected monthly for 6 months. Attempts were also made to rear P. maculata in captivity. Tetrodotoxin was detected in samples from eight of the ten sites. The highest average (368.7 mg kg−1) and maximum (1414.0 mg kg−1) concentrations were measured in samples from Illiomama Rock (Auckland). Of the toxic populations tested there was significant variability in TTX concentrations among individuals, with the highest difference (62 fold) measured at Illiomama Rock. Tetrodotoxin concentrations in samples from Narrow Neck Beach varied temporally, ranging from an average of 184 mg kg−1 in June 2010 to 17.5 mg kg−1 by December 2010. There was no correlation between TTX levels and mass. The highest levels correspond with the egg laying season (June–August) and this, in concert with the detection of high levels of TTX in eggs and early larval stages, suggests that TTX may have a defensive function in P. maculata. Only one larva was successfully reared to full maturation and no TTX was detected. PMID:22363228

Linking In-Vehicle Ultrafine Particle Exposures to On-Road Concentrations

PubMed Central

Hudda, Neelakshi; Eckel, Sandrah P.; Knibbs, Luke D.; Sioutas, Constantinos; Delfino, Ralph J.; Fruin, Scott A.

2013-01-01

For traffic-related pollutants like ultrafine particles (UFP, Dp < 100 nm), a significant fraction of overall exposure occurs within or close to the transit microenvironment. Therefore, understanding exposure to these pollutants in such microenvironments is crucial to accurately assessing overall UFP exposure. The aim of this study was to develop models for predicting in-cabin UFP concentrations if roadway concentrations are known, taking into account vehicle characteristics, ventilation settings, driving conditions and air exchange rates (AER). Particle concentrations and AER were measured in 43 and 73 vehicles, respectively, under various ventilation settings and driving speeds. Multiple linear regression (MLR) and generalized estimating equation (GEE) regression models were used to identify and quantify the factors that determine inside-to-outside (I/O) UFP ratios and AERs across a full range of vehicle types and ages. AER was the most significant determinant of UFP I/O ratios, and was strongly influenced by ventilation setting (recirculation or outside air intake). Inclusion of ventilation fan speed, vehicle age or mileage, and driving speed explained greater than 79% of the variability in measured UFP I/O ratios. PMID:23888122

Utilization of concentrate after membrane filtration of sugar beet thin juice for ethanol production.

PubMed

Kawa-Rygielska, Joanna; Pietrzak, Witold; Regiec, Piotr; Stencel, Piotr

2013-04-01

The subject of this study was to investigate the feasibility of the concentrate obtained after membrane ultrafiltration of sugar beet thin juice for ethanol production and selection of fermentation conditions (yeast strain and media supplementation). Resulting concentrate was subjected to batch ethanol fermentation using two strains of Saccharomyces cerevisiae (Ethanol Red and Safdistill C-70). The effect of different forms of media supplementation (mineral salts: (NH4)2SO4, K2HPO4, MgCl2; urea+Mg3(PO4)2 and yeast extract) on the fermentation course was also studied. It was stated that sugar beet juice concentrate is suitable for ethanol production yielding, depending on the yeast strain, ca. 85-87 g L(-1) ethanol with ca. 82% practical yield and more than 95% of sugars consumption after 72 h of fermentation. Nutrients enrichment further increased ethanol yield. The best results were obtained for media supplemented with urea+Mg3(PO4)2 yielding 91.16-92.06 g L(-1) ethanol with practical yield ranging 84.78-85.62% and full sugars consumption. Copyright © 2013. Published by Elsevier Ltd.

Major-ion chemistry of the Rocky Mountain snowpack, USA

USGS Publications Warehouse

Turk, J.T.; Taylor, Howard E.; Ingersoll, G.P.; Tonnessen, K.A.; Clow, D.W.; Mast, M.A.; Campbell, D.H.; Melack, J.M.

2001-01-01

During 1993-97, samples of the full depth of the Rocky Mountain snowpack were collected at 52 sites from northern New Mexico to Montana and analyzed for major-ion concentrations. Concentrations of acidity, sulfate, nitrate, and calcium increased from north to south along the mountain range. In the northern part of the study area, acidity was most correlated (negatively) with calcium. Acidity was strongly correlated (positively) with nitrate and sulfate in the southern part and for the entire network. Acidity in the south exceeded the maximum acidity measured in snowpack of the Sierra Nevada and Cascade Mountains. Principal component analysis indicates three solute associations we characterize as: (1) acid (acidity, sulfate, and nitrate), (2) soil (calcium, magnesium, and potassium), and (3) salt (sodium, chloride, and ammonium). Concentrations of acid solutes in the snowpack are similar to concentrations in nearby wetfall collectors, whereas, concentrations of soil solutes are much higher in the snowpack than in wetfall. Thus, dryfall of acid solutes during the snow season is negligible, as is gypsum from soils. Snowpack sampling offers a cost-effective complement to sampling of wetfall in areas where wetfall is difficult to sample and where the snowpack accumulates throughout the winter. Copyright ?? 2001 .

Fresnel Lens

NASA Technical Reports Server (NTRS)

Watson, Michael D.; Scott, Steve; Lamb, David; Zimmerman, Joe E. (Technical Monitor)

2001-01-01

Fresnel lenses span the full range of sizes from lens a few micrometers in diameter to lens several meters in diameter. These lenses are utilized in various fields including optical communication, theatrical lighting, office equipment, video entertainment systems, solar concentrators, and scientific research instruments. These lenses function either as diffractive or refractive optical elements depending on the geometrical feature size of the lens. The basic functions of these lenses is described followed by an overview of fabrication methods. A summary of applications is then provided illustrating the rich variety of applications for which fresnel lenses may be designed to fulfill.

A Synoptic Study of Fecal-Indicator Bacteria in the Wind River, Bighorn River, and Goose Creek Basins, Wyoming, June-July 2000

USGS Publications Warehouse

Clark, Melanie L.; Gamper, Merry E.

2003-01-01

A synoptic study of fecal-indicator bacteria was conducted during June and July 2000 in the Wind River, Bighorn River, and Goose Creek Basins in Wyoming as part of the U.S. Geological Survey's National Water-Quality Assessment Program for the Yellowstone River Basin. Fecal-coliform concentrations ranged from 2 to 3,000 col/100 mL (colonies per 100 milliliters) for 100 samples, and Escherichia coli concentrations ranged from 1 to 2,800 col/100 mL for 97 samples. Fecal-coliform concentrations exceeded the U.S. Environmental Protection Agency's recommended limit for a single sample for recreational contact with water in 37.0 percent of the samples. Escherichia coli concentrations exceeded the U.S. Environmental Protection Agency's recommended limit for a single sample for moderate use, full-body recreational contact with water in 38.1 percent of the samples and the recommended limit for infrequent use, full-body recreational contact with water in 24.7 percent of the samples. Fecal-indicator-bacteria concentrations varied by basin. Samples from the Bighorn River Basin had the highest median concentrations for fecal coliform of 340 col/100 mL and for Escherichia coli of 300 col/100 mL. Samples from the Wind River Basin had the lowest median concentrations for fecal coliform of 50 col/100 mL and for Escherichia coli of 62 col/100 mL. Fecal-indicator-bacteria concentrations varied by land cover. Samples from sites with an urban land cover had the highest median concentrations for fecal coliform of 540 col/100 mL and for Escherichia coli of 420 col/100 mL. Maximum concentrations for fecal coliform of 3,000 col/100 mL and for Escherichia coli of 2,800 col/100 mL were in samples from sites with an agricultural land cover. The lowest median concentrations for fecal coliform of 130 col/100 mL and for Escherichia coli of 67 col/100 mL were for samples from sites with a forested land cover. A strong and positive relation existed between fecal coliform and Escherichia coli (Spearman's Rho value of 0.976). The majority of the fecal coliforms were Escherichia coli during the synoptic study. Fecal-indicator-bacteria concentrations were not correlated to streamflow, water temperature, dissolved oxygen, pH, specific conduc-tance, and alkalinity. Fecal-indicator-bacteria concentrations were moderately correlated with turbidity (Spearman's Rho values of 0.662 and 0.640 for fecal coliform and Escherichia coli, respectively) and sediment (Spearman's Rho values of 0.628 and 0.636 for fecal coliform and Escherichia coli, respectively). Escherichia coli isolates analyzed by discriminant analysis of ribotype patterns for samples from the Bighorn River at Basin, Wyoming, and Bitter Creek near Garland, Wyoming, in the Bighorn River Basin were determined to be from nonhuman and human sources. Using a confidence interval of 90 percent, more of the isolates from both sites were classified as being from nonhuman than human sources; however, both samples had additional isolates that were classified as unknown sources. --------------------------------------------------------------------------------

The Efficacy of Full Range Advising at a Georgia Technical College

ERIC Educational Resources Information Center

Greco, Victor

2017-01-01

Full Range Leadership predicts positive behavioral outcomes through transformational leadership, mixed outcomes through transactional leadership, and unfavorable outcomes through passive leadership practices. Full Range Advising introduces a new paradigm in advising research by applying Full Range Leadership to academic advising. A problem exists…

Control of Atmospheric CO2 by the Ocean's Biological Pump and Shelf-Basin Fractionation

NASA Astrophysics Data System (ADS)

Anderson, R. F.; Fleisher, M. Q.; Mix, A. C.

2006-12-01

Identifying the cause of the dramatic correlation between atmospheric CO2 concentrations and past climate variability has been one of the principal goals of paleoclimate research over the past quarter century. Several plausible mechanisms have been proposed, and each has been rejected as being incapable by itself of accounting for the full range (80 to 100 ppm) of glacial to interglacial variability of atmospheric CO2 concentration. Consequently, recent studies have focused on scenarios by which a combination of mechanisms work synergistically to account for the full range of CO2 variability. We will present evidence from equatorial Pacific sediment cores that increased strength of the ocean's biological pump was primarily responsible for drawdown of atmospheric CO2 during the early stages of glaciation, and that increased ocean alkalinity (or, more specifically, an increase in the ocean carbonate ion concentration) led to a further reduction of atmospheric CO2 during maximum glaciation. Increased strength of the biological pump is manifest as increasing differences between the carbon isotope composition of planktonic and benthic foraminifera during early stages of glaciation, as predicted a quarter century ago in classic works by Broecker and by Shackleton. Increased carbonate ion concentration is manifest by increased preservation and burial of calcium carbonate in deep equatorial Pacific sediments. The carbon isotope record is noisy, but the pattern is repeated over each of the past three glacial cycles, lending confidence to its reliability. Increased preservation and burial of CaCO3 occurred each time the oxygen isotope composition of benthic foraminifera rose above a threshold value corresponding to a sea level lowering of roughly 70 m below present. This relationship is reproduced systematically throughout the past 450 kyr, again lending confidence to the finding and supporting the view that shelf-basin fractionation, or the shift in CaCO3 deposition from continental shelves to the deep sea, was involved. There is substantial uncertainty in the sensitivity of atmospheric CO2 to each of these factors, but the records suggest roughly equal CO2 drawdown by each process.

Compatibility of a Conventional Non-aqueous Magnesium Electrolyte with a High Voltage V 2O 5 Cathode and Mg Anode

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

Sa, Niya; Proffit, Danielle L.; Lipson, Albert L.

2015-08-01

A major roadblock for magnesium ion battery development is the availability of an electrolyte that can deposit Mg reversibly and at the same time is compatible with a high voltage cathode. We report a prospective full magnesium cell utilizing a simple, non-aqueous electrolyte composed of high concentration magnesium bis(trifluoromethane sulfonyl)imide in diglyme, which is compatible with a high voltage vanadium pentoxide (V 2O 5) cathode and a Mg metal anode. For this system, plating and stripping of Mg metal can be achieved with magnesium bis(trifluoromethane sulfonyl)imide in diglyme electrolyte over a wide concentration range, however, reversible insertion of Mg intomore » V 2O 5 cathode can only be attained at high electrolyte concentrations. Reversible intercalation of Mg into V 2O 5 is characterized and confirmed by X-ray diffraction, X-ray absorption near edge spectroscopy and energy dispersive spectroscopy.« less

Particle-Size-Exclusion Clogging Regimes in Porous Media

NASA Astrophysics Data System (ADS)

Gerber, G.; Rodts, S.; Aimedieu, P.; Faure, P.; Coussot, P.

2018-04-01

From observations of the progressive deposition of noncolloidal particles by geometrical exclusion effects inside a 3D model porous medium, we get a complete dynamic view of particle deposits over a full range of regimes from transport over a long distance to clogging and caking. We show that clogging essentially occurs in the form of an accumulation of elements in pore size clusters, which ultimately constitute regions avoided by the flow. The clusters are dispersed in the medium, and their concentration (number per volume) decreases with the distance from the entrance; caking is associated with the final stage of this effect (for a critical cluster concentration at the entrance). A simple probabilistic model, taking into account the impact of clogging on particle transport, allows us to quantitatively predict all these trends up to a large cluster concentration, based on a single parameter: the clogging probability, which is a function of the confinement ratio. This opens the route towards a unification of the different fields of particle transport, clogging, caking, and filtration.

Pharmacokinetics and selected pharmacodynamics of trazodone following intravenous and oral administration to horses undergoing fitness training.

PubMed

Knych, Heather K; Mama, Khursheed R; Steffey, Eugene P; Stanley, Scott D; Kass, Philip H

2017-10-01

OBJECTIVE To measure concentrations of trazodone and its major metabolite in plasma and urine after administration to healthy horses and concurrently assess selected physiologic and behavioral effects of the drug. ANIMALS 11 Thoroughbred horses enrolled in a fitness training program. PROCEDURES In a pilot investigation, 4 horses received trazodone IV (n = 2) or orally (2) to select a dose for the full study; 1 horse received a vehicle control treatment IV. For the full study, trazodone was initially administered IV (1.5 mg/kg) to 6 horses and subsequently given orally (4 mg/kg), with a 5-week washout period between treatments. Blood and urine samples were collected prior to drug administration and at multiple time points up to 48 hours afterward. Samples were analyzed for trazodone and metabolite concentrations, and pharmacokinetic parameters were determined; plasma drug concentrations following IV administration best fit a 3-compartment model. Behavioral and physiologic effects were assessed. RESULTS After IV administration, total clearance of trazodone was 6.85 ± 2.80 mL/min/kg, volume of distribution at steady state was 1.06 ± 0.07 L/kg, and elimination half-life was 8.58 ± 1.88 hours. Terminal phase half-life was 7.11 ± 1.70 hours after oral administration. Horses had signs of aggression and excitation, tremors, and ataxia at the highest IV dose (2 mg/kg) in the pilot investigation. After IV drug administration in the full study (1.5 mg/kg), horses were ataxic and had tremors; sedation was evident after oral administration. CONCLUSIONS AND CLINICAL RELEVANCE Administration of trazodone to horses elicited a wide range of effects. Additional study is warranted before clinical use of trazodone in horses can be recommended.

Ambient air pollution and birth weight in full-term infants in Atlanta, 1994-2004.

PubMed

Darrow, Lyndsey A; Klein, Mitchel; Strickland, Matthew J; Mulholland, James A; Tolbert, Paige E

2011-05-01

An emerging body of evidence suggests that ambient levels of air pollution during pregnancy are associated with fetal growth. We examined relationships between birth weight and temporal variation in ambient levels of carbon monoxide, nitrogen dioxide (NO₂), sulfur dioxide (SO₂), ozone, particulate matter ≤ 10 μm in diameter (PM₁₀), ≤ 2.5 μm (PM(2.5)), 2.5 to 10 µm (PM(2.5-10)), and PM(2.5) chemical component measurements for 406,627 full-term births occurring between 1994 and 2004 in five central counties of metropolitan Atlanta. We assessed relationships between birth weight and pollutant concentrations during each infant's first month of gestation and third trimester, as well as in each month of pregnancy using distributed lag models. We also conducted capture-area analyses limited to mothers residing within 4 miles (6.4 km) of each air quality monitoring station. In the five-county analysis, ambient levels of NO₂, SO₂, PM(2.5) elemental carbon, and PM(2.5) water-soluble metals during the third trimester were significantly associated with small reductions in birth weight (-4 to -16 g per interquartile range increase in pollutant concentrations). Third-trimester estimates were generally higher in Hispanic and non-Hispanic black infants relative to non-Hispanic white infants. Distributed lag models were also suggestive of associations between air pollutant concentrations in late pregnancy and reduced birth weight. The capture-area analyses provided little support for the associations observed in the five-county analysis. Results provide some support for an effect of ambient air pollution in late pregnancy on birth weight in full-term infants.

A new method to generate a high-resolution global distribution map of lake chlorophyll

USGS Publications Warehouse

Sayers, Michael J; Grimm, Amanda G.; Shuchman, Robert A.; Deines, Andrew M.; Bunnell, David B.; Raymer, Zachary B; Rogers, Mark W.; Woelmer, Whitney; Bennion, David; Brooks, Colin N.; Whitley, Matthew A.; Warner, David M.; Mychek-Londer, Justin G.

2015-01-01

A new method was developed, evaluated, and applied to generate a global dataset of growing-season chlorophyll-a (chl) concentrations in 2011 for freshwater lakes. Chl observations from freshwater lakes are valuable for estimating lake productivity as well as assessing the role that these lakes play in carbon budgets. The standard 4 km NASA OceanColor L3 chlorophyll concentration products generated from MODIS and MERIS sensor data are not sufficiently representative of global chl values because these can only resolve larger lakes, which generally have lower chl concentrations than lakes of smaller surface area. Our new methodology utilizes the 300 m-resolution MERIS full-resolution full-swath (FRS) global dataset as input and does not rely on the land mask used to generate standard NASA products, which masks many lakes that are otherwise resolvable in MERIS imagery. The new method produced chl concentration values for 78,938 and 1,074 lakes in the northern and southern hemispheres, respectively. The mean chl for lakes visible in the MERIS composite was 19.2 ± 19.2, the median was 13.3, and the interquartile range was 3.90–28.6 mg m−3. The accuracy of the MERIS-derived values was assessed by comparison with temporally near-coincident and globally distributed in situmeasurements from the literature (n = 185, RMSE = 9.39, R2 = 0.72). This represents the first global-scale dataset of satellite-derived chl estimates for medium to large lakes.

Prototype of the gas chromatograph - mass spectrometer to investigate volatile species in the lunar soil for the Luna-Glob and Luna-Resurs missions.

NASA Astrophysics Data System (ADS)

Hofer, L.; Lasi, D.; Tulej, M.; Wurz, P.; Cabane, M.; Cosica, D.; Gerasimov, M.; Rodinov, D.

2013-09-01

In preparation for the Russian Luna-Glob and Luna-Resurs missions we combined our compact time-offlight mass spectrometer (TOF-MS) with a chemical pre-separation of the species by gas chromatography (GC). Combined measurements with both instruments were successfully performed with the laboratory prototype of the mass spectrometer and a flight-like gas chromatograph. Due to its capability to record mass spectra over the full mass range at once with high sensitivity and a dynamic range of up to 106 within 1s, the TOF-MS system is a valuable extension of the GC analysis. The combined GC-MS complex is able to detect concentrations of volatile species in the sample of about 2·10^-9 by mass.

Pressurized liquid extraction using water/isopropanol coupled with solid-phase extraction cleanup for industrial and anthropogenic waste-indicator compounds in sediment

USGS Publications Warehouse

Burkhardt, M.R.; ReVello, R.C.; Smith, S.G.; Zaugg, S.D.

2005-01-01

A broad range of organic compounds is recognized as environmentally relevant for their potential adverse effects on human and ecosystem health. This method was developed to better determine the distribution of 61 compounds that are typically associated with industrial and household waste as well as some that are toxic and known (or suspected) for endocrine-disrupting potential extracted from environmental sediment samples. Pressurized liquid extraction (PLE) coupled with solid-phase extraction (SPE) was used to reduce sample preparation time, reduce solvent consumption to one-fifth of that required using dichloromethane-based Soxhlet extraction, and to minimize background interferences for full scan GC/MS analysis. Recoveries from spiked Ottawa sand, commercially available topsoil, and environmental stream sediment, fortified at 4-720 ??g per compound, averaged 76 ?? 13%. Initial method detection limits for single-component compounds ranged from 12.5 to 520 ??g/kg, based on 25 g samples. Results from 103 environmental sediment samples show that 36 out of 61 compounds (59%) were detected in at least one sample with concentrations ranging from 20 to 100,000 ??g/kg. The most frequently detected compound, beta-sitosterol, a plant sterol, was detected in 87 of the 103 (84.5%) environmental samples with a concentration range 360-100,000 ??g/kg. Results for a standard reference material using dichloromethane Soxhlet-based extraction are also compared. ?? 2004 Published by Elsevier B.V.

Cometabolic degradation of ethyl mercaptan by phenol-utilizing Ralstonia eutropha in suspended growth and gas-recycling trickle-bed reactor.

PubMed

Sedighi, Mahsa; Zamir, Seyed Morteza; Vahabzadeh, Farzaneh

2016-01-01

The degradability of ethyl mercaptan (EM), by phenol-utilizing cells of Ralstonia eutropha, in both suspended and immobilized culture systems, was investigated in the present study. Free-cells experiments conducted at EM concentrations ranging from 1.25 to 14.42 mg/l, showed almost complete removal of EM at concentrations below 10.08 mg/l, which is much higher than the maximum biodegradable EM concentration obtained in experiments that did not utilize phenol as the primary substrate, i.e. 2.5 mg/l. The first-order kinetic rate constant (kSKS) for EM biodegradation by the phenol-utilizing cells (1.7 l/g biomass/h) was about 10 times higher than by cells without phenol utilization. Immobilized-cells experiments performed in a gas recycling trickle-bed reactor packed with kissiris particles at EM concentrations ranging from 1.6 to 36.9 mg/l, showed complete removal at all tested concentrations in a much shorter time, compared with free cells. The first-order kinetic rate constant (rmaxKs) for EM utilization was 0.04 l/h for the immobilized system compared to 0.06 for the suspended-growth culture, due to external mass transfer diffusion. Diffusion limitation was decreased by increasing the recycling-liquid flow rate from 25 to 65 ml/min. The removed EM was almost completely mineralized according to TOC and sulfate measurements. Shut down and starvation experiments revealed that the reactor could effectively handle the starving conditions and was reliable for full-scale application. Copyright © 2015 Elsevier Ltd. All rights reserved.

Prevalence of nucleic acid sequences specific for human parvoviruses, hepatitis A and hepatitis E viruses in coagulation factor concentrates.

PubMed

Modrow, S; Wenzel, J J; Schimanski, S; Schwarzbeck, J; Rothe, U; Oldenburg, J; Jilg, W; Eis-Hübinger, A M

2011-05-01

Due to their high resistance to inactivation procedures, nonenveloped viruses such as parvovirus B19, human bocavirus (HBoV), human parvovirus 4 (PARV4), hepatitis A (HAV) and hepatitis E virus (HEV) pose a particular threat to blood products. Virus transmission to patients treated with blood products presents an additional burden to disease. We determined the frequency and the amount of nucleic acid specific for nonenveloped viruses in recently manufactured preparations of commercial coagulation factor concentrates. At least three different batches of each of 13 different plasma-derived and recombinant coagulation factor products were tested for the presence and the amount of nucleic acid for parvovirus B19, HBoV, human parvovirus 4, hepatitis A virus and HEV by using quantitative polymerase chain reaction. Whereas none of the recombinant products tested positive for any of these viruses, parvovirus B19 DNA with amounts ranging between 2×10(1) and 1.3×10(3) genome equivalents/ml was detected in five plasma-derived products. In addition to parvovirus B19 genotype 1, genotypes 2 and 3 were observed in two batches of a factor VIII/von-Willebrand factor product. In two products (one factor VIII concentrate and one activated prothrombin complex concentrate), a combination of both genotypes 1 and 2 of parvovirus B19 was detected. The data show that nucleic acids from several relevant nonenveloped viruses are not found at detectable levels in coagulation factor concentrates. In some cases, parvovirus B19 DNA was detectable at low levels. Testing of the plasma pools for the full range of parvovirus genotypes is advocated for ensuring product safety. © 2010 The Author(s). Vox Sanguinis © 2010 International Society of Blood Transfusion.

Decadal variability in coastal phytoplankton community composition in a changing West Antarctic Peninsula

NASA Astrophysics Data System (ADS)

Schofield, Oscar; Saba, Grace; Coleman, Kaycee; Carvalho, Filipa; Couto, Nicole; Ducklow, Hugh; Finkel, Zoe; Irwin, Andrew; Kahl, Alex; Miles, Travis; Montes-Hugo, Martin; Stammerjohn, Sharon; Waite, Nicole

2017-06-01

The coastal waters of the West Antarctic Peninsula (WAP) are associated with large phytoplankton blooms dominated by large (>20 μm) diatoms however, nanoplankton (<20 μm) are also an important component of the food web. The dominant nanoflagellates in the WAP are cryptomonad algae. Using a twenty-year time series collected by the Palmer Long Term Ecological Research program at the United States Palmer Research Station, we assessed long-term patterns and stability in the coastal phytoplankton communities in the WAP. There was significant interannual variability in the integrated water column chlorophyll a (chl-a) concentrations, which varied by a factor of 5 over the 20-year time series. There has been a significant positive increase in the seasonally integrated concentration of chl-a over the time series. The dominant phytoplankton were diatoms, with cryptophytes the second most abundant. Mixed flagellates also constituted a significant fraction of the chl-a but showed less interannual variability than diatoms and cryophytes. Peak phytoplankton biomass was observed in summer months, when monthly averaged wind speed was lower than in the fall and autumn. Cryptophytes were most abundant during the summer months (December-January) after the seasonal retreat of sea ice. While diatoms were observed over the full range of observed salinities 32-34.5) as well as over the full range of in situ temperatures (-1.5 to 2.5 °C), the cryptophyte populations were observed in locations with lower salinity 32.5-33.75) and colder water (-1 to 1 °C). Environmental factors that favored a shallower seasonal mixed layer resulted in larger diatom blooms compared to the other phytoplankton taxa. During summer with lower phytoplankton biomass, a larger proportion of the chlorophyll a was associated with cryptophytes. These results demonstrate that continued temperature changes along the West Antarctic Peninsula will result in changes in phytoplankton concentration and community composition, which has significant ramifications for the food web.

Fate of natural organic matter at a full-scale Drinking Water Treatment Plant in Greece.

PubMed

Papageorgiou, A; Papadakis, N; Voutsa, D

2016-01-01

The aim of this study was to investigate the fate of natural organic matter (NOM) and subsequent changes during the various treatment processes at a full-scale Drinking Water Treatment Plant (DWTP). Monthly sampling campaigns were conducted for 1 year at six sites along DWTP of Thessaloniki, Northern Greece including raw water from the Aliakmonas River that supplies DWTP and samples from various treatment processes (pre-ozonation, coagulation, sand filtration, ozonation, and granular activated carbon (GAC) filtration). The concentration of NOM and its characteristics as well as the removal efficiency of various treatment processes on the basis of dissolved organic carbon, UV absorbance, specific ultra-violet absorbance, fluorescence intensity, hydrophobicity, biodegradable dissolved organic carbon, and formation potential of chlorination by-products trihalomethanes (THMs) and haloacetic acids (HAAs) were studied. The concentration of dissolved organic carbon (DOC) in reservoir of the Aliakmonas River ranged from 1.46 to 1.84 mg/L, exhibiting variations regarding UV, fluorescence, and hydrophobic character through the year. Along DWTP, a significant reduction of aromatic, fluorophoric, and hydrophobic character of NOM was observed resulting in significant elimination of THM (63%) and HAAs (75%) precursors.

Physical and biochemical properties of the euphausiids Thysanoessa inermis, Thysanoessa raschii, and Thysanoessa longipes in the eastern Bering Sea

NASA Astrophysics Data System (ADS)

Harvey, H. Rodger; Pleuthner, Rachel L.; Lessard, Evelyn J.; Bernhardt, Megan J.; Tracy Shaw, C.

2012-06-01

Euphausiids are an integral part of the Bering Sea ecosystem, linking primary production to upper level trophic levels as both consumers and prey. Species native to this region extend over a range of geographic provinces and serve as a critical component of the movement of energy through the food web. As one facet of the BEST-BSIERP Bering Sea program, we determined the proximate composition and essential allometric relationships of multiple species of euphausiids collected over three years in the eastern Bering Sea. Three euphausiid species were examined: Thysanoessa inermis, Thysanoessa raschii, and Thysanoessa longipes. While the three species were similar with respect to size, T. inermis had the highest average wet and dry weights per size class, as well as highest carbon and caloric concentrations. Among the three species, T. inermis and T. longipes had similar lipid concentrations, with T. longipes showing higher average lipid concentrations. Empirical equations were developed to describe fundamental relationships between length, weight, PC/PN, and calorie and lipid content for the three species over the full range of sizes encountered in the study area. Such relationships increase our understanding of how euphausiids contribute to the carbon budget and energy input in the eastern Bering Sea system and help to define realistic parameters for ongoing and future modeling efforts.

Experimental investigation of a nanofluid absorber employed in a low-profile, concentrated solar thermal collector

NASA Astrophysics Data System (ADS)

Li, Qiyuan; Zheng, Cheng; Mesgari, Sara; Hewakuruppu, Yasitha L.; Hjerrild, Natasha; Crisostomo, Felipe; Morrison, Karl; Woffenden, Albert; Rosengarten, Gary; Scott, Jason A.; Taylor, Robert A.

2015-12-01

Recent studies [1-3] have demonstrated that nanotechnology, in the form of nanoparticles suspended in water and organic liquids, can be employed to enhance solar collection via direct volumetric absorbers. However, current nanofluid solar collector experimental studies are either relevant to low-temperature flat plate solar collectors (<100 °C) [4] or higher temperature (>100 °C) indoor laboratory-scale concentrating solar collectors [1, 5]. Moreover, many of these studies involve in thermal properties of nanofluid (such as thermal conductivity) enhancement in solar collectors by using conventional selective coated steel/copper tube receivers [6], and no full-scale concentrating collector has been tested at outdoor condition by employing nanofluid absorber [2, 6]. Thus, there is a need of experimental researches to evaluate the exact performance of full-scale concentrating solar collector by employing nanofluids absorber at outdoor condition. As reported previously [7-9], a low profile (<10 cm height) solar thermal concentrating collector was designed and analysed which can potentially supply thermal energy in the 100-250 °C range (an application currently met by gas and electricity). The present study focuses on the design and experimental investigation of a nanofluid absorber employed in this newly designed collector. The nanofluid absorber consists of glass tubes used to contain chemically functionalized multi-walled carbon nanotubes (MWCNTs) dispersed in DI water. MWCNTs (average diameter of 6-13 nm and average length of 2.5-20 μm) were functionalized by potassium persulfate as an oxidant. The nanofluids were prepared with a MCWNT concentration of 50 +/- 0.1 mg/L to form a balance between solar absorption depth and viscosity (e.g. pumping power). Moreover, experimentally comparison of the thermal efficiency between two receivers (a black chrome-coated copper tube versus a MWCNT nanofluid contained within a glass tubetube) is investigated. Thermal experimentation reveals that while the collector efficiency reduced from 73% to 54% when operating temperature increased from ambient to 80 °C by employing a MWCNT nanofluid receiver, the efficiency decreased from 85% to 68% with same operating temperature range by employing black chrome-coated copper tube receiver. This difference can mainly be explained by the reflection optical loss off and higher thermal emission heat loss the front surface of the glass tube, yielding a 90% of transmittance to the MWCNT fluid and a 0.9 emissivity of glass pipe. Overall, an experimental investigation of the performance of a low profile solar collector with a direct volumetric absorber and conventional surface absorber is presented. In order to bring nanotechnology into industrial and commercial heating applications,

Properties important to mixing and simulant recommendations for WTP full-scale vessel testing

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

Poirier, M. R.; Martino, C. J.

2015-12-01

Full Scale Vessel Testing (FSVT) is being planned by Bechtel National, Inc., to demonstrate the ability of the standard high solids vessel design (SHSVD) to meet mixing requirements over the range of fluid properties planned for processing in the Pretreatment Facility (PTF) of the Hanford Waste Treatment and Immobilization Plant (WTP). Testing will use simulated waste rather than actual Hanford waste. Therefore, the use of suitable simulants is critical to achieving the goals of the test program. WTP personnel requested the Savannah River National Laboratory (SRNL) to assist with development of simulants for use in FSVT. Among the tasks assignedmore » to SRNL was to develop a list of waste properties that are important to pulse-jet mixer (PJM) performance in WTP vessels with elevated concentrations of solids.« less

Quantifying creativity: can measures span the spectrum?

PubMed

Simonton, Dean Keith

2012-03-01

Because the cognitive neuroscientists have become increasingly interested in the phenomenon of creativity, the issue arises of how creativity is to be optimally measured. Unlike intelligence, which can be assessed across the full range of intellectual ability creativity measures tend to concentrate on different sections of the overall spectrum. After first defining creativity in terms of the three criteria of novelty, usefulness, and surprise, this article provides an overview of the available measures. Not only do these instruments vary according to whether they focus on the creative process, person, or product, but they differ regarding whether they tap into "little-c" versus "Big-C" creativity; only productivity and eminence measures reach into genius-level manifestations of the phenomenon. The article closes by discussing whether various alternative assessment techniques can be integrated into a single measure that quantifies creativity across the full spectrum.

Reconnaissance investigation of water quality, bottom sediment, and biota associated with irrigation drainage in the Lower Rio Grande Valley and Laguna Atascosa National Wildlife Refuge, Texas, 1986-87

USGS Publications Warehouse

Wells, Frank C.; Jackson, Gerry A.; Rogers, William J.

1988-01-01

Toxaphene was detected in 11 fish samples; detectable concentrations ranged from 0.98 to 5.1 micrograms per gram, wet weight. DOT also was detected in 11 fish samples with concentrations ranging from 0.021 to 0.066 micrograms per gram, wet weight. ODD was detected in 21 fish samples; concentrations ranged from 0.015 to 0.16 micrograms per gram, wet weight. DDE was detected in all 22 fish samples, and concentrations ranged from 0.36 to 9.9 micrograms per gram, wet weight. The maximum concentrations of DOT and ODD exceeded the 1980-81 baseline concentrations. The median and maximum concentrations of toxaphene and DDE exceeded the 1980-81 baseline concentrations. The largest concentrations of toxaphene, ODD, and DDE in fish were all measured in samples collected at the Main Floodway near Progreso.

Biological monitoring of benzene exposure for process operators during ordinary activity in the upstream petroleum industry.

PubMed

Bråtveit, Magne; Kirkeleit, Jorunn; Hollund, Bjørg Eli; Moen, Bente E

2007-07-01

This study characterized the exposure of crude oil process operators to benzene and related aromatics during ordinary activity and investigated whether the operators take up benzene at this level of exposure. We performed the study on a fixed, integrated oil and gas production facility on Norway's continental shelf. The study population included 12 operators and 9 referents. We measured personal exposure to benzene, toluene, ethylbenzene and xylene during three consecutive 12-h work shifts using organic vapour passive dosimeter badges. We sampled blood and urine before departure to the production facility (pre-shift), immediately after the work shift on Day 13 of the work period (post-shift) and immediately before the following work shift (pre-next shift). We also measured the exposure to hydrocarbons during short-term tasks by active sampling using Tenax tubes. The arithmetic mean exposure over the 3 days was 0.042 ppm for benzene (range <0.001-0.69 ppm), 0.05 ppm for toluene, 0.02 ppm for ethylbenzene and 0.03 ppm for xylene. Full-shift personal exposure was significantly higher when the process operators performed flotation work during the shift versus other tasks. Work in the flotation area was associated with short-term (6-15 min) arithmetic mean exposure to benzene of 1.06 ppm (range 0.09-2.33 ppm). The concentrations of benzene in blood and urine did not differ between operators and referents at any time point. When we adjusted for current smoking in regression analysis, benzene exposure was significantly associated with the post-shift concentration of benzene in blood (P = 0.01) and urine (P = 0.03), respectively. Although these operators perform tasks with relatively high short-term exposure to benzene, the full-shift mean exposure is low during ordinary activity. Some evidence indicates benzene uptake within this range of exposure.

Broiler litter as a micronutrient source for cotton: concentrations in plant parts.

PubMed

Tewolde, H; Sistani, K R; Rowe, D E

2005-01-01

Analytically, poultry litter contains nearly all essential micronutrients but the extent of phytoavailability of these nutrients and whether cotton (Gossypium hirsutum L.) and other crop plants can receive adequate amounts of these nutrients from litter is not fully known. The objective of this research was to determine whether cotton receives sufficient amounts of Fe, Cu, Mn, and Zn from litter and estimate the efficiency of cotton in extracting these metal nutrients from litter in the absence of any other source of the micronutrients. The greenhouse research used plastic pots filled with approximately 11 kg of a 2:1 (v/v) sand to vermiculite growing mix. Cotton (cv. Stoneville 474) was grown in the pots fertilized with broiler litter at rates of 30, 60, 90, or 120 g pot(-1) in a factorial combination with four supplemental nutrient solution (NS) treatments. The nutrient solutions consisted of full Hoagland's nutrient solution (NS-full); a solution of the macronutrients N, P, K, Ca, and Mg (NS-macro); a solution of the micronutrients Fe, Zn, Mn, Cu, B, and Mo (NS-micro); and water (NS-none). Based on tissue nutrient analysis, a one-time broiler litter application supplied adequate amounts of Fe, Cu, and Mn to bring the concentration of these nutrients in upper leaves within published sufficiency ranges. Zinc, with <17 mg kg(-1) concentration in the upper leaves, was the only micronutrient below the established sufficiency range regardless of the rate of applied litter. Cotton extracted Fe and Mn more efficiently than Cu or Zn, removing as much as 8.8% of Fe and 7.2% of Mn supplied by 30 g litter pot(-1). In contrast, the extraction efficiency was 1.7% for Cu and 1.9% for Zn. Roots accumulated 58% of the total absorbed Fe and 64% of Cu, and leaves accumulated 32% of the Fe and only 13% of the Cu supplied by litter. In contrast, only 16% of the total absorbed Mn and 23% of Zn accumulated in roots while leaves accumulated 64% of the total Mn and 37% of Zn. These results demonstrate that broiler litter is a valuable source of the metal nutrients supplying Fe, Cu, and Mn in full and Zn in part, but a very large fraction of the litter-supplied metal nutrients remained in the growing mix.

A Review of Gender and Full-Range Leadership Research and Suggestions for Future Research

ERIC Educational Resources Information Center

Smith, Kelli K.; Matkin, Gina S.; Fritz, Susan M.

2004-01-01

In this paper the research on gender and Full-Range Leadership is documented and explored. Included is consideration of research that studied Full-Range Leadership directly as well as indirect study that contributed to the field of research on Full-Range Leadership. The paper culminates in a series of recommendations for future research. It is…

Assessment of the ion-trap mass spectrometer for routine qualitative and quantitative analysis of drugs of abuse extracted from urine.

PubMed

Vorce, S P; Sklerov, J H; Kalasinsky, K S

2000-10-01

The ion-trap mass spectrometer (MS) has been available as a detector for gas chromatography (GC) for nearly two decades. However, it still occupies a minor role in forensic toxicology drug-testing laboratories. Quadrupole MS instruments make up the majority of GC detectors used in drug confirmation. This work addresses the use of these two MS detectors, comparing the ion ratio precision and quantitative accuracy for the analysis of different classes of abused drugs extracted from urine. Urine specimens were prepared at five concentrations each for amphetamine (AMP), methamphetamine (METH), benzoylecgonine (BZE), delta9-carboxy-tetrahydrocannabinol (delta9-THCCOOH), phencyclidine (PCP), morphine (MOR), codeine (COD), and 6-acetylmorphine (6-AM). Concentration ranges for AMP, METH, BZE, delta9-THCCOOH, PCP, MOR, COD, and 6-AM were 50-2500, 50-5000, 15-800, 1.5-65, 1-250, 500-32000, 250-21000, and 1.5-118 ng/mL, respectively. Sample extracts were injected into a GC-quadrupole MS operating in selected ion monitoring (SIM) mode and a GC-ion-trap MS operating in either selected ion storage (SIS) or full scan (FS) mode. Precision was assessed by the evaluation of five ion ratios for n = 15 injections at each concentration using a single-point calibration. Precision measurements for SIM ion ratios provided coefficients of variation (CV) between 2.6 and 9.8% for all drugs. By comparison, the SIS and FS data yielded CV ranges of 4.0-12.8% and 4.0-11.2%, respectively. The total ion ratio failure rates were 0.2% (SIM), 0.7% (SIS), and 1.2% (FS) for the eight drugs analyzed. Overall, the SIS mode produced stable, comparable mean ratios over the concentration ranges examined, but had greater variance within batch runs. Examination of postmortem and quality-control samples produced forensically accurate quantitation by SIS when compared to SIM. Furthermore, sensitivity of FS was equivalent to SIM for all compounds examined except for 6-AM.

Appraisal of water-quality conditions, lower Black River, Windsor County, Vermont

USGS Publications Warehouse

Toppin, K.W.

1983-01-01

Six hydroelectric power dams are planned along a 22-mile reach of the lower Black River in southeastern Windsor County, Vermont. Data were collected at 10 stations, during water years 1977-81, to appraise quality conditions before construction. Average specific conductance of Black River is 101 micromhos indicating low concentrations of dissolved solids. Concentrations of common constituents and minor elements were generally low and within safe levels for aquatic life. Near-saturated dissolved oxygen concentrations and relatively low mean total organic carbon concentrations indicate little oxygen-consuming substances in Black River. Mean total nitrogen concentrations ranged from 0.31 mg/L (milligrams per liter) to 0.61 mg/L. The highest concentrations were most likely due to secondary waste discharges entering the river. Nitrate was the primary form of inorganic nitrogen, mean concentrations ranged from 0.13 to 0.27 mg/L. Concentrations seem high enough to promote excessive algal growth in the proposed Hawks Mountain Reservoir. Mean concentrations of total phosphorus ranged from 0.014 to 0.112 mg/L as P. Maximum concentrations at all stations generally exceeded U.S. Environmental Protection Agency suggested levels for water entering lakes and reservoirs. Mean orthophosphorus concentrations ranged from 0.005 to 0.029 mg/L, suggesting a potential for nuisance algal conditions to develop in the proposed reservoir. Mean algal growth potential concentrations ranged from 1.3 to 8.8 mg/L, falling within the moderately high to high productivity range. No pesticides and polychlorinated biphenyls were detected. (USGS)

Experimental study of iron-chloride complexing in hydrothermal fluids

USGS Publications Warehouse

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

1992-01-01

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

Homogenous isotropic invisible cloak based on geometrical optics.

PubMed

Sun, Jingbo; Zhou, Ji; Kang, Lei

2008-10-27

Invisible cloak derived from the coordinate transformation requires its constitutive material to be anisotropic. In this work, we present a cloak of graded-index isotropic material based on the geometrical optics theory. The cloak is realized by concentric multilayered structure with designed refractive index to achieve the low-scattering and smooth power-flow. Full-wave simulations on such a design of a cylindrical cloak are performed to demonstrate the cloaking ability to incident wave of any polarization. Using normal nature material with isotropy and low absorption, the cloak shows light on a practical path to stealth technology, especially that in the optical range.

The Development of a Tactical-Level Full Range Leadership Measurement Instrument

DTIC Science & Technology

2010-03-01

full range leadership theory has become established as the predominant and most widely researched theory on leadership . The most commonly used survey...instrument to assess full range leadership theory is the Multifactor Leadership Questionnaire, originally developed by Bass in 1985. Although much...existing literature to develop a new full range leadership theory measurement instrument that effectively targets low- to mid-level supervisors, or

Relationship between water and aragonite barium concentrations in aquaria reared juvenile corals

USGS Publications Warehouse

Gonneea, Meagan; Cohen, Anne L.; DeCarlo, Thomas M.; Charette, Matthew A.

2017-01-01

Coral barium to calcium (Ba/Ca) ratios have been used to reconstruct records of upwelling, river and groundwater discharge, and sediment and dust input to the coastal ocean. However, this proxy has not yet been explicitly tested to determine if Ba inclusion in the coral skeleton is directly proportional to seawater Ba concentration and to further determine how additional factors such as temperature and calcification rate control coral Ba/Ca ratios. We measured the inclusion of Ba within aquaria reared juvenile corals (Favia fragum) at three temperatures (∼27.7, 24.6 and 22.5 °C) and three seawater Ba concentrations (73, 230 and 450 nmol kg−1). Coral polyps were settled on tiles conditioned with encrusting coralline algae, which complicated chemical analysis of the coral skeletal material grown during the aquaria experiments. We utilized Sr/Ca ratios of encrusting coralline algae (as low as 3.4 mmol mol−1) to correct coral Ba/Ca for this contamination, which was determined to be 26 ± 11% using a two end member mixing model. Notably, there was a large range in Ba/Ca across all treatments, however, we found that Ba inclusion was linear across the full concentration range. The temperature sensitivity of the distribution coefficient is within the range of previously reported values. Finally, calcification rate, which displayed large variability, was not correlated to the distribution coefficient. The observed temperature dependence predicts a change in coral Ba/Ca ratios of 1.1 μmol mol−1 from 20 to 28 °C for typical coastal ocean Ba concentrations of 50 nmol kg−1. Given the linear uptake of Ba by corals observed in this study, coral proxy records that demonstrate peaks of 10–25 μmol mol−1 would require coastal seawater Ba of between 60 and 145 nmol kg−1. Further validation of the coral Ba/Ca proxy requires evaluation of changes in seawater chemistry associated with the environmental perturbation recorded by the coral as well as verification of these results for Porites species, which are widely used in paleo reconstructions.

Effects of supplementation with a calcium-rich marine-derived multi-mineral supplement and short-chain fructo-oligosaccharides on serum lipids in postmenopausal women.

PubMed

Cronin, Barbara E; Allsopp, Philip J; Slevin, Mary M; Magee, Pamela J; Livingstone, M Barbara E; Strain, J J; McSorley, Emeir M

2016-02-28

Recent literature suggests that Ca supplements have adverse effects on cardiovascular health. The effects of a Ca-rich supplement administered alone or in combination with short-chain fructo-oligosaccharides (scFOS) on serum lipids in postmenopausal women were examined using secondary data from a 24-month double-blind randomised controlled study. A total of 300 postmenopausal women were randomly assigned to daily supplements of 800 mg of Ca (2·4 g Aquamin) (Ca), 800 mg of Ca with 3 g of scFOS (CaFOS) or control (maltodextrin) (MD). A full lipid profile, body composition, blood pressure and a range of cytokines were measured at baseline and after 24 months. Intention-to-treat ANCOVA assessed treatment effects between the groups. A significant time-by-treatment effect was observed for LDL and total cholesterol for the Ca and CaFOS groups, with both groups having lower LDL and total cholesterol concentrations compared with MD after 24 months. The control group had mean (5·2 mmol/l) total cholesterol concentrations above the normal range (≤ 5 mmol/l) at 24 months, whereas values remained within the normal range in the treatment groups. There was no significant treatment effect on HDL-cholesterol, TAG, body composition, blood pressure or cytokine concentrations at 24 months, with the exception of IL-4, where there was a significant increase in the CaFOS group compared with the placebo. This study demonstrates a lipid-lowering effect of both the Ca-rich supplement alone and the supplement with scFOS. At the 4-year follow-up, there was no significant difference between the groups for reported diagnosed cardiovascular conditions.

Sirolimus Pharmacokinetics in Early Postmyeloablative Pediatric Blood and Marrow Transplantation

PubMed Central

Goyal, Rakesh K.; Han, Kelong; Wall, Donna A.; Pulsipher, Michael A.; Bunin, Nancy; Grupp, Stephan A.; Mada, Sripal R.; Venkataramanan, Raman

2014-01-01

This study examined the pharmacokinetics of sirolimus in pediatric allogeneic blood and marrow transplantation (BMT) recipients in the presence and absence of concomitant fluconazole. Forty pediatric BMT recipients received a daily oral dose of sirolimus and a continuous i.v. infusion of tacrolimus for graft-versus-host disease prophylaxis. Fluconazole was administered i.v. to 19 patients and orally to 6 patients. Full pharmacokinetic profiles of sirolimus within a single dosing interval were collected. Whole-blood sirolimus concentrations were measured by HPLC/mass spectrometry. Noncompartmental analysis was performed using WinNonlin. Nonlinear mixed-effects pharmacokinetic models were developed using NONMEM following standard procedures. The mean ± SD sirolimus trough level before the dose (C0) was 8.0 ± 4.6 ng/mL (range, 1.8–21.6 ng/mL). The peak concentration was 19.9 ± 11.8 ng/mL (range, 3.9–46.1 ng/mL), and the trough level 24 hours later (C24) was 9.1 ± 5.3 ng/mL (range, 1.0–19.1 ng/mL). The terminal disposition half-life (T1/2) was 24.5 ± 11.2 hours (range, 5.8–53.2 hours), and the area under the concentration-versus-time curve (AUC0–24) was 401.1 ± 316.3 ng·h/mL (range, 20.7–1332.3 ng·h/mL). In patients at steady state, C0 and C24 were closely correlated (R2 = 0.77) with a slope of 0.99, indicating the achievement of steady state. C24 was 1.7-fold greater (P = .036) and AUC0–24 was 2-fold greater (P = .012) in Caucasian patients (n = 22) compared with Hispanic patients (n = 9). The average apparent oral clearance was 3-fold greater (P = .001) and the apparent oral volume of distribution was 2-fold greater (P = .018) in patients age ≤12 years compared with those age >12 years. C24 was significantly lower in patients (n = 10) who developed grade III–IV aGVHD (n = 10) than in those with grade 0-II aGVHD (n = 22) (6.1 ± 2.9 ng/mL versus 9.4 ± 5.5 ng/mL; P = .044). Dose-normalized sirolimus trough concentrations were significantly higher in patients receiving concomitant fluconazole therapy compared with those not receiving fluconazole (C0: 3.9 ± 2.5 versus 2.4 ± 1.5 ng/mL/mg, P = .030; C24: 4.8 ± 3.3 versus 2.5 ± 1.7 ng/mL/mg, P = .018). This pharmacokinetic study of sirolimus in pediatric patients documents a large interindividual variability in the exposure of sirolimus. Steady-state trough blood concentrations were correlated with drug exposure. Trough concentrations were higher with a concomitant use of fluconazole and were higher in Caucasian patients than in Hispanic patients. Oral clearance was greater in children age ≤12 years than in older children and adolescents. With therapeutic drug monitoring, the majority (79%) of sirolimus trough levels could be maintained within the target range (3–12 ng/mL). This study provides a rationale and support for dose adjustments of sirolimus based on steady-state blood concentrations aimed at achieving a target concentration to minimize toxicity and maximize therapeutic benefits in pediatric BMT recipients. PMID:23266742

Long-term observations of cloud condensation nuclei in the Amazon rain forest

NASA Astrophysics Data System (ADS)

Pöhlker, Mira L.; Pöhlker, Christopher; Ditas, Florian; Klimach, Thomas; Hrabe de Angelis, Isabella; Brito, Joel; Carbone, Samara; Cheng, Yafang; Martin, Scot T.; Moran-Zuloaga, Daniel; Rose, Diana; Saturno, Jorge; Su, Hang; Thalman, Ryan; Walter, David; Wang, Jian; Barbosa, Henrique; Artaxo, Paulo; Andreae, Meinrat O.; Pöschl, Ulrich

2017-04-01

Size-resolved long-term measurements of atmospheric aerosol and cloud condensation nuclei (CCN) concentrations and hygroscopicity were conducted at the remote Amazon Tall Tower Observatory (ATTO) in the central Amazon Basin over a full seasonal cycle (Mar 2014 - Feb 2015). The measurements provide a climatology of CCN properties characteristic of a remote central Amazonian rain forest site [1,2]. The CCN measurements were continuously cycled through 10 levels of supersaturation (S = 0.11 to 1.10 %) and span the aerosol particle size range from 20 to 245 nm. The particle hygroscopicity exhibits a pronounced size dependence with lower values for the Aitken mode (κAit = 0.14 ± 0.03), higher values for the accumulation mode (κAcc = 0.22 ± 0.05), and an overall mean value of κmean = 0.17 ± 0.06, consistent with high fractions of organic aerosol. The hygroscopicity parameter, κ, exhibits remarkably little temporal variability: no pronounced diurnal cycles, only weak seasonal trends, and few short-term variations during long-range transport events. In contrast, the CCN number concentrations exhibit a pronounced seasonal cycle, tracking the pollution-related seasonality in total aerosol concentration. We find that the variability in the CCN concentrations in the central Amazon is mostly driven by aerosol particle number concentration and size distribution, while variations in aerosol hygroscopicity and chemical composition matter only during a few episodes. For modelling purposes, we compare different approaches of predicting CCN number concentration and present a novel parameterization, which allows accurate CCN predictions based on a small set of input data. In addition, we analyzed the CCN short-term variability in relation to air mass changes as well as aerosol emission and transformation processes. The CCN short term variability is presented for selected case studies, which analyze particularly interesting and characteristic events/conditions in the Amazon region. References: [1] Andreae, M. O., et al. (2015), Atmos. Chem. Phys., 15, 10723-10776. [2] Pöhlker, M. L.., et al. (2016), Atmos. Chem. Phys., 16, 15709-15740.

Activation of Cyclic AMP Synthesis by Full and Partial Beta-Adrenergic Receptor Agonists in Chicken Skeletal Muscle Cells

NASA Technical Reports Server (NTRS)

Young, R. B.; Bridge, K. Y.

2003-01-01

Several beta-adrenergic receptor (bAR) agonists are known to cause hypertrophy of skeletal muscle tissue. Accordingly, five bAR agonists encompassing a range in activity from strong to weak were evaluated for their ability to stimulate CAMP accumulation in embryonic chicken skeletal muscle cells in culture. Two strong agonists (epinephrine and isoproterenol), one moderate agonist (albuterol), and two weak agonists known to cause hypertrophy in animals (clenbuterol and cimaterol) were studied. Dose response curves were determined over six orders of magnitude in concentration for each agonist, and values were determined for their maximum stimulation of CAMP synthesis rate (Bmax) and the agonist concentration at which 50% stimulation of CAMP synthesis (EC50) occurred. Bmax values decreased in the following order: isoproterenol, epinephrine, albuterol, cimaterol, clenbuterol. Cimaterol and clenbuterol at their Bmax concentrations were approximately 15-fold weaker than isoproterenol in stimulating the rate of CAMP synthesis. When cimaterol and clenbuterol were added to culture media at concentrations known to cause significant muscle hypertrophy in animals, there was no detectable effect on stimulation of CAMP synthesis. Finally, these same levels of cimaterol and clenbuterol did not antagonize the stimulation of CAMP by either epinephrine or isoproterenol.

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

NASA Astrophysics Data System (ADS)

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

2017-11-01

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

The Impact of Sea Ice Concentration Accuracies on Climate Model Simulations with the GISS GCM

NASA Technical Reports Server (NTRS)

Parkinson, Claire L.; Rind, David; Healy, Richard J.; Martinson, Douglas G.; Zukor, Dorothy J. (Technical Monitor)

2000-01-01

The Goddard Institute for Space Studies global climate model (GISS GCM) is used to examine the sensitivity of the simulated climate to sea ice concentration specifications in the type of simulation done in the Atmospheric Modeling Intercomparison Project (AMIP), with specified oceanic boundary conditions. Results show that sea ice concentration uncertainties of +/- 7% can affect simulated regional temperatures by more than 6 C, and biases in sea ice concentrations of +7% and -7% alter simulated annually averaged global surface air temperatures by -0.10 C and +0.17 C, respectively, over those in the control simulation. The resulting 0.27 C difference in simulated annual global surface air temperatures is reduced by a third, to 0.18 C, when considering instead biases of +4% and -4%. More broadly, least-squares fits through the temperature results of 17 simulations with ice concentration input changes ranging from increases of 50% versus the control simulation to decreases of 50% yield a yearly average global impact of 0.0107 C warming for every 1% ice concentration decrease, i.e., 1.07 C warming for the full +50% to -50% range. Regionally and on a monthly average basis, the differences can be far greater, especially in the polar regions, where wintertime contrasts between the +50% and -50% cases can exceed 30 C. However, few statistically significant effects are found outside the polar latitudes, and temperature effects over the non-polar oceans tend to be under 1 C, due in part to the specification of an unvarying annual cycle of sea surface temperatures. The +/- 7% and 14% results provide bounds on the impact (on GISS GCM simulations making use of satellite data) of satellite-derived ice concentration inaccuracies, +/- 7% being the current estimated average accuracy of satellite retrievals and +/- 4% being the anticipated improved average accuracy for upcoming satellite instruments. Results show that the impact on simulated temperatures of imposed ice concentration changes is least in summer, encouragingly the same season in which the satellite accuracies are thought to be worst. Hence the impact of satellite inaccuracies is probably less than the use of an annually averaged satellite inaccuracy would suggest.

Occupational Exposure to Cobalt and Tungsten in the Swedish Hard Metal Industry: Air Concentrations of Particle Mass, Number, and Surface Area

PubMed Central

Bryngelsson, Ing-Liss; Pettersson, Carin; Husby, Bente; Arvidsson, Helena; Westberg, Håkan

2016-01-01

Exposure to cobalt in the hard metal industry entails severe adverse health effects, including lung cancer and hard metal fibrosis. The main aim of this study was to determine exposure air concentration levels of cobalt and tungsten for risk assessment and dose–response analysis in our medical investigations in a Swedish hard metal plant. We also present mass-based, particle surface area, and particle number air concentrations from stationary sampling and investigate the possibility of using these data as proxies for exposure measures in our study. Personal exposure full-shift measurements were performed for inhalable and total dust, cobalt, and tungsten, including personal real-time continuous monitoring of dust. Stationary measurements of inhalable and total dust, PM2.5, and PM10 was also performed and cobalt and tungsten levels were determined, as were air concentration of particle number and particle surface area of fine particles. The personal exposure levels of inhalable dust were consistently low (AM 0.15mg m−3, range <0.023–3.0mg m−3) and below the present Swedish occupational exposure limit (OEL) of 10mg m−3. The cobalt levels were low as well (AM 0.0030mg m−3, range 0.000028–0.056mg m−3) and only 6% of the samples exceeded the Swedish OEL of 0.02mg m−3. For continuous personal monitoring of dust exposure, the peaks ranged from 0.001 to 83mg m−3 by work task. Stationary measurements showed lower average levels both for inhalable and total dust and cobalt. The particle number concentration of fine particles (AM 3000 p·cm−3) showed the highest levels at the departments of powder production, pressing and storage, and for the particle surface area concentrations (AM 7.6 µm2·cm−3) similar results were found. Correlating cobalt mass-based exposure measurements to cobalt stationary mass-based, particle area, and particle number concentrations by rank and department showed significant correlations for all measures except for particle number. Linear regression analysis of the same data showed statistically significant regression coefficients only for the mass-based aerosol measures. Similar results were seen for rank correlation in the stationary rig, and linear regression analysis implied significant correlation for mass-based and particle surface area measures. The mass-based air concentration levels of cobalt and tungsten in the hard metal plant in our study were low compared to Swedish OELs. Particle number and particle surface area concentrations were in the same order of magnitude as for other industrial settings. Regression analysis implied the use of stationary determined mass-based and particle surface area aerosol concentration as proxies for various exposure measures in our study. PMID:27143598

The utility of ultra-performance liquid chromatography/electrospray ionisation time-of-flight mass spectrometry for multi-residue determination of pesticides in strawberry.

PubMed

Taylor, Michael J; Keenan, George A; Reid, Kirsty B; Fernández, Diana Uría

2008-09-01

The utility of ultra-performance liquid chromatography/orthogonal-acceleration time-of flight mass spectrometry (UPLC/TOFMS) for the rapid qualitative and quantitative analysis of 100 pesticides targeted in strawberry was assessed by comparing results with those obtained using a validated in-house UPLC tandem mass spectrometry (MS/MS) multi-residue method. Crude extracts from retail strawberry samples received as part of the 2007 annual UK pesticide residues in food surveillance programme were screened for the presence of pesticide residues using UPLC/TOFMS. Accurate mass measurement of positive and negative ions allowed their extraction following 'full mass range data acquisition' with negligible interference from background or co-eluting species observed during UPLC gradient separation (in a cycle time of just 6.5 min per run). Extracted ion data was used to construct calibration curves and to detect and identify any incurred residues (i.e. pesticides incorporated in or on the test material following application during cultivation, harvest and storage). Calibration using matrix-matched standards was performed over a narrow concentration range of 0.005-0.04 mg kg(-1) with determination coefficients (r2) > or =0.99 for all analytes with the exception of malathion/fenarimol/fludioxanil (r2 = 0.98), quassia/pymetrazine (r2 = 0.97) and fenthion sulfone (r2 = 0.95). Residues found in selected samples ranged from 0.025-0.28 mg kg(-1) and were in excellent agreement with results obtained using UPLC/MS/MS. Mass measurement accuracies of < or =5 ppm were achieved consistently throughout the separation, mass range and concentration range of interest thus providing the opportunity to obtain discrete elemental compositions of target ions.

Infrasonic observations of large-scale HE events

NASA Technical Reports Server (NTRS)

Whitaker, Rodney W.; Mutschlecner, J. Paul; Davidson, Masha B.; Noel, Susan D.

1990-01-01

The Los Alamos Infrasound Program has been operating since about mid-1982, making routine measurements of low frequency atmospheric acoustic propagation. Generally, the authors work between 0.1 Hz to 10 Hz; however, much of the work is concerned with the narrower range of 0.5 to 5.0 Hz. Two permanent stations, St. George, UT, and Los Alamos, NM, have been operational since 1983, collecting data 24 hours a day. For the purposes of this discussion, the authors concentrate on their measurements of large, high explosive (HE) events at ranges of 250 km to 5330 km. Because their equipment is well suited for mobile deployments, they can easily establish temporary observing sites for special events. The measurements are from the permanent sites, as well as from various temporary sites. A few observations that are typical of the full data set are given.

Seasonal variations in the concentration and removal of nonylphenol ethoxylates from the wastewater of a sewage treatment plant.

PubMed

Gao, Dawen; Li, Zhe; Guan, Junxue; Liang, Hong

2017-04-01

In this study, we investigated the occurrence and fate of nonylphenol (NP), nonylphenol monoethoxylate (NP1EO) and nonylphenol diethoxylate (NP2EO) in a full scale sewage treatment plant, which applied an Anaerobic/Oxic process. Concentrations of NP, NP1EO and NP2EO in the wastewater were measured during the period spanning a whole year. The results showed remarkable seasonal variation in the concentrations of the compounds. The NPnEO compounds were most abundant in winter, with the total concentrations of influent NP, NP1EO and NP2EO ranging from 3900 to 7000ng/L, 4000 to 4800ng/L and 5200 to 7200ng/L, respectively. Regarding the total removal efficiencies of the three types of short-chain NPnEO compounds, different trends were exhibited according to different seasons. The average removal efficiency of NP for the different seasons ranked as follows: winter>summer>autumn>spring; NP2EO concentrations decreased as follows: summer>autumn>winter>spring, while NP1EO concentrations reduced according to: spring>summer>autumn>winter. We also investigated the contribution ratio of individual treatment units in the A/O process, with the findings suggesting that the anaerobic treatment unit plays an important role in the elimination of short-chain NPnEOs from the wastewater. Copyright © 2016. Published by Elsevier B.V.

Genotoxic effects of Roundup Full II® on lymphocytes of Chaetophractus villosus (Xenarthra, Mammalia): In vitro studies.

PubMed

Luaces, Juan Pablo; Rossi, Luis Francisco; Chirino, Mónica Gabriela; Browne, Melanie; Merani, María Susana; Mudry, Marta Dolores

2017-01-01

In Argentina, Chaetophractus villosus has a wide distribution that overlaps with agricultural areas where soybean is the predominant crop. In such areas the pesticide Roundup Full II® (RU) is widely applied. The genotoxic effect of its active ingredient glyphosate (RU is 66.2% glyphosate) on the peripheral blood lymphocytes of C. villosus was tested over a range of concentrations (280, 420, 560, 1120 μmol/L). Culture medium without glyphosate served as negative control, while medium containing mitomycin C served as positive control. Genetic damage was characterized in terms of the percentage of cells with chromosome aberrations (CA), the mean number of sister chromatid exchanges (SCE) per cell, and the modification of cell proliferation kinetics via the calculation of the replication index. Significant increases (p < 0.0001) were seen in the CA frequency and the mean number of SCEs per cell compared to negative controls at all the RU concentrations tested. Chromatid breaks, the only form of CA observed, under the 560 μmol/L RU conditions and in presence of mitomycin C were four to five times more common than at lower concentrations, while no viable cells were seen in the 1120 μmol/L treatment. The mean number of SCEs per cell was significantly higher under the 280 μmol/L RU conditions than the 420 or 560 μmol/L RU conditions; cells cultivated in the presence of MMC also showed significantly more SCEs. All the RU concentrations tested (except in the 1120 μmol/L RU treatment [no viable cells]) induced a significant reduction in the replication index (p < 0.0001). The present results confirm the genotoxic effects of RU on C. villosus lymphocytes in vitro, strongly suggesting that exposure to RU could induce DNA damage in C. villosus wildlife.

Serum fructosamine concentrations in dogs with hypothyroidism.

PubMed

Reusch, C E; Gerber, B; Boretti, F S

2002-10-01

Serum fructosamine concentrations were measured in 11 untreated hypothyroid dogs with normal serum glucose and serum protein concentrations. The fructosamine level ranged between 276 and 441 micromol/L (median 376 micromol/L; reference range 207-340 micromol/L). Nine of the 11 dogs had fructosamine levels above the reference range. The fructosamine levels decreased significantly during treatment with levothyroxine. It is suggested that serum fructosamine concentrations may be high in hypothyroid dogs because of decelerated protein turnover, independent of the blood glucose concentration.

Impact of particle concentration and out-of-range sizes on the measurements of the LISST

NASA Astrophysics Data System (ADS)

Zhao, Lin; Boufadel, Michel C.; King, Thomas; Robinson, Brian; Conmy, Robyn; Lee, Kenneth

2018-05-01

The instrument LISST (laser in situ scattering and transmissiometry) has been widely used for measuring the size of oil droplets in relation to oil spills and sediment particles. Major concerns associated with using the instrument include the impact of high concentrations and/or out-of-range particle (droplet) sizes on the LISST reading. These were evaluated experimentally in this study using monosized microsphere particles. The key findings include: (1) When high particle concentration reduced the optical transmission (OT) to below 30%, the measured peak value tended to underestimate the true peak value, and the accuracy of the LISST decreased by ~8% to ~28%. The maximum concentration to reach the 30% OT was about 50% of the theoretical values, suggesting a lower concentration level should be considered during the instrument deployment. (2) The out-of-range sizes of particles affected the LISST measurements when the sizes were close to the LISST measurement range. Fine below-range sizes primarily affected the data in the lowest two bins of the LISST with  >75% of the volume at the smallest bin. Large out-of-range particles affected the sizes of the largest 8–10 bins only when very high concentration was present. The out-of-range particles slightly changed the size distribution of the in-range particles, but their concentration was conserved. An approach to interpret and quantify the effects of the out-of-range particles on the LISST measurement was proposed.

[Dynamics of seed rain of Tripterygium hypoglaucum and soil seed bank].

PubMed

Zhang, Zhi-Wei; Wei, Yong-Sheng; Liu, Xiang; Su, Shu; Qu, Xian-You; Wang, Chang-Hua

2017-11-01

Tripterygium hypoglaucum is an endangered species in arid areas of Xiannvshan Chongqing, China. The dynamic characteristics of seed rain and soil seed bank of T. hypoglaucum were studied in this paper．Results showed that T. hypoglaucum years of mature seeds distribution number up to October; the seed rain occurred from the last ten-day of September to in the first ten-day of November and the peak of scattered seed rain concentrated in the October．The numbers of soil seed bank at 2-5 cm soil layer,mainly concentrated in the 1.5-3.5 m range. T. hypoglaucum seeds to the wind as a force for transmission, the transmission ability is strong, but in the process of natural reproduction, full mature seed rate is low, the soil seed bank seeds seed short-lived factors these were unfavorable for the natural reproduction of T. hypoglaucum population. Copyright© by the Chinese Pharmaceutical Association.

Changes in passive tension of muscle in humans and animals after eccentric exercise

PubMed Central

Whitehead, N P; Weerakkody, N S; Gregory, J E; Morgan, D L; Proske, U

2001-01-01

This is a report of experiments on ankle extensor muscles of human subjects and a parallel series on the medial gastrocnemius of the anaesthetised cat, investigating the origin of the rise in passive tension after a period of eccentric exercise. Subjects exercised their triceps surae of one leg eccentrically by walking backwards on an inclined, forward-moving treadmill. Concentric exercise required walking forwards on a backwards-moving treadmill. For all subjects the other leg acted as a control. Immediately after both eccentric and concentric exercise there was a significant drop in peak active torque, but only after eccentric exercise was this accompanied by a shift in optimum angle for torque generation and a rise in passive torque. In the eccentrically exercised group some swelling and soreness developed but not until 24 h post-exercise. In the animal experiments the contracting muscle was stretched by 6 mm at 50 mm s−1 over a length range symmetrical about the optimum length for tension generation. Measurements of passive tension were made before and after the eccentric contractions, using small stretches to a range of muscle lengths, or with large stretches covering the full physiological range. After 150 eccentric contractions, passive tension was significantly elevated over most of the range of lengths. Measurements of work absorption during stretch-release cycles showed significant increases after the contractions. It is suggested that the rise in passive tension in both human and animal muscles after eccentric contractions is the result of development of injury contractures in damaged muscle fibres. PMID:11389215

Time and size resolved Measurement of Mass Concentration at an Urban Site

NASA Astrophysics Data System (ADS)

Karg, E.; Ferron, G. A.; Heyder, J.

2003-04-01

Time- and size-resolved measurements of ambient particles are necessary for modelling of atmospheric particle transport, the interpretation of particulate pollution events and the estimation of particle deposition in the human lungs. In the size range 0.01 - 2 µm time- and size-resolved data are obtained from differential mobility and optical particle counter measurements and from gravimetric filter analyses on a daily basis (PM2.5). By comparison of the time averaged and size integrated particle volume concentration with PM2.5 data, an average density of ambient particles can be estimated. Using this density, the number concentration data can be converted in time- and size-resolved mass concentration. Such measurements were carried out at a Munich downtown crossroads. The spectra were integrated in the size ranges 10 - 100 nm, 100 - 500 nm and 500 - 2000 nm. Particles in these ranges are named ultrafine, fine and coarse particles. These ranges roughly represent freshly emitted particles, aged/accumulated particles and particles entrained by erosive processes. An average number concentration of 80000 1/cm3 (s.d. 67%), a particle volume concentration of 53 µm3/cm3 (s.d. 76%) and a PM2.5 mass concentration of 27 µg/m3 was found. These particle volume- and PM2.5 data imply an average density of 0.51 g/cm3. Average number concentration showed 95.3%, 4.7% and 0.006% of the total particle concentration in the size ranges mentioned above. Mass concentration was 14.7%, 80.2% and 5.1% of the total, assuming the average density to be valid for all particles. The variability in mass concentration was 94%, 75% and 33% for the three size ranges. Nearly all ambient particles were in the ultrafine size range, whereas most of the mass concentration was in the fine size range. However, a considerable mass fraction of nearly 15% was found in the ultrafine size range. As the sampling site was close to the road and traffic emissions were the major source of the particles, 1) the density was very low due to agglomerated and porous structures of freshly emitted combustion particles and 2) the variability was highest in the ultrafine range, obviously correlated to traffic activity and lowest in the micron size range. In conclusion, almost all ambient particles were ultrafine particles, whereas most of the particle mass was associated with fine particles. Nevertheless, a considerable mass fraction was found in the ultrafine size range. These particles had a very low density so that they can be considered as agglomerated and porous particles emitted from vehicles passing the crossroads. Therefore they showed a much higher variation in mass concentration than the fine and coarse particles.

Urban-air-toxics Monitoring Program carbonyl results, 1990

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

Not Available

1991-07-01

The report summarizes the results of sampling ambient air for selected carbonyl containing compounds in 12 urban centers in the contiguous United States as part of the Urban Air Toxics Monitoring Program (UATMP). Formaldehyde, acetaldehyde, and acetone concentrations were measured using 2,4-dinitrophenylhydrazine (DNPH)-coated silica cartridges to collect the carbonyls for subsequent analysis. Sampling and analysis followed guidance provided in U.S. Environmental Protection Agency (EPA) compendium method TO-11. Formaldehyde concentrations ranged from 0.42 to 34.5 ppbv with an average concentration for all sites of 4.2 ppbv. Site average formaldehyde concentrations ranged from 1.5 ppbv for Houston, TX (H1TX) to 7.9 formore » Washington, DC (W2DC). Acetaldehyde concentrations ranged from 0.37 to 9.5 ppbv, averaging 1.7 ppbv over all 1990 UATMP sites. Site average acetaldehyde concentrations ranged from 0.76 ppbv at Houston, TX (H1TX) to 2.5 ppbv at Baton Rouge, LA (BRLA). Acetone concentrations ranged from 0.37 to 10.8 ppbv and averaged 1.8 ppbv over all sites. Site average acetone concentrations ranged from 0.68 ppbv at Houston, TX (H1TX) to 2.9 ppbv at Chicago, IL (C4IL).« less

Acute aerobic exercise differentially alters acylated ghrelin and perceived fullness in normal-weight and obese individuals.

PubMed

Heden, Timothy D; Liu, Ying; Park, Youngmin; Dellsperger, Kevin C; Kanaley, Jill A

2013-09-01

Adiposity alters acylated ghrelin concentrations, but it is unknown whether adiposity alters the effect of exercise and feeding on acylated ghrelin responses. Therefore, the purpose of this study was to determine whether adiposity [normal-weight (NW) vs. obese (Ob)] influences the effect of exercise and feeding on acylated ghrelin, hunger, and fullness. Fourteen NW and 14 Ob individuals completed two trials in a randomized counterbalanced fashion, including a prior exercise trial (EX) and a no exercise trial (NoEX). During the EX trial, the participants performed 1 h of treadmill walking (55-60% peak O2 uptake) during the evening, 12 h before a 4-h standardized mixed meal test. Frequent blood samples were taken and analyzed for acylated ghrelin, and a visual analog scale was used to assess perceived hunger and fullness. In NW individuals, EX, compared with NoEX, reduced fasting acylated ghrelin concentrations by 18% (P = 0.03), and, in response to feeding, the change in acylated ghrelin (P = 0.02) was attenuated by 39%, but perceived hunger and fullness were unaltered. In Ob individuals, despite no changes in fasting or postprandial acylated ghrelin concentrations with EX, postprandial fullness was attenuated by 46% compared with NoEX (P = 0.05). In summary, exercise performed the night before a meal suppresses acylated ghrelin concentrations in NW individuals without altering perceived hunger or fullness. In Ob individuals, despite no changes in acylated ghrelin concentrations, EX reduced the fullness response to the test meal. Acylated ghrelin and perceived fullness responses are differently altered by acute aerobic exercise in NW and Ob individuals.

Quantifying creativity: can measures span the spectrum?

PubMed Central

Simonton, Dean Keith

2012-01-01

Because the cognitive neuroscientists have become increasingly interested in the phenomenon of creativity, the issue arises of how creativity is to be optimally measured. Unlike intelligence, which can be assessed across the full range of intellectual ability creativity measures tend to concentrate on different sections of the overall spectrum. After first defining creativity in terms of the three criteria of novelty, usefulness, and surprise, this article provides an overview of the available measures. Not only do these instruments vary according to whether they focus on the creative process, person, or product, but they differ regarding whether they tap into “little-c” versus “Big-C” creativity; only productivity and eminence measures reach into genius-level manifestations of the phenomenon. The article closes by discussing whether various alternative assessment techniques can be integrated into a single measure that quantifies creativity across the full spectrum. PMID:22577309

A phantom design for assessment of detectability in PET imaging

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

Wollenweber, Scott D., E-mail: scott.wollenweber@g

2016-09-15

Purpose: The primary clinical role of positron emission tomography (PET) imaging is the detection of anomalous regions of {sup 18}F-FDG uptake, which are often indicative of malignant lesions. The goal of this work was to create a task-configurable fillable phantom for realistic measurements of detectability in PET imaging. Design goals included simplicity, adjustable feature size, realistic size and contrast levels, and inclusion of a lumpy (i.e., heterogeneous) background. Methods: The detection targets were hollow 3D-printed dodecahedral nylon features. The exostructure sphere-like features created voids in a background of small, solid non-porous plastic (acrylic) spheres inside a fillable tank. The featuresmore » filled at full concentration while the background concentration was reduced due to filling only between the solid spheres. Results: Multiple iterations of feature size and phantom construction were used to determine a configuration at the limit of detectability for a PET/CT system. A full-scale design used a 20 cm uniform cylinder (head-size) filled with a fixed pattern of features at a contrast of approximately 3:1. Known signal-present and signal-absent PET sub-images were extracted from multiple scans of the same phantom and with detectability in a challenging (i.e., useful) range. These images enabled calculation and comparison of the quantitative observer detectability metrics between scanner designs and image reconstruction methods. The phantom design has several advantages including filling simplicity, wall-less contrast features, the control of the detectability range via feature size, and a clinically realistic lumpy background. Conclusions: This phantom provides a practical method for testing and comparison of lesion detectability as a function of imaging system, acquisition parameters, and image reconstruction methods and parameters.« less

Optimization of wastewater microalgae saccharification using dilute acid hydrolysis for acetone, butanol, and ethanol fermentation

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

Castro, Yessica; Ellis, Joshua T.; Miller, Charles D.

2015-02-01

Exploring and developing sustainable and efficient technologies for biofuel production are crucial for averting global consequences associated with fuel shortages and climate change. Optimization of sugar liberation from wastewater algae through acid hydrolysis was determined for subsequent fermentation to acetone, butanol, and ethanol (ABE) by Clostridium saccharoperbutylacetonicum N1-4. Acid concentration, retention time, and temperature were evaluated to determine optimal hydrolysis conditions by assessing the sugar and ABE yield as well as the associated costs. Sulfuric acid concentrations ranging from 0-1.5 M, retention times of 40-120 min, and temperatures from 23°C- 90°C were combined to form a full factorial experiment. Acidmore » hydrolysis pretreatment of 10% dried wastewater microalgae using 1.0 M sulfuric acid for 120 min at 80-90°C was found to be the optimal parameters, with a sugar yield of 166.1 g for kg of dry algae, concentrations of 5.23 g/L of total ABE, and 3.74 g/L of butanol at a rate of USD $12.83 per kg of butanol.« less

Mercury data from small lakes in Voyageurs National Park, northern Minnesota, 2000-02

USGS Publications Warehouse

Goldstein, Robert M.; Brigham, Mark E.; Steuwe, Luke; Menheer, Michael A.

2003-01-01

Mercury contamination of aquatic ecosystems is a resource concern in Voyageurs National Park. High concentrations of mercury in fish pose a potential risk to organisms that consume large amounts of those fish. During 2000–02, the U.S. Geological Survey measured mercury in water collected from 20 lakes in Voyageurs National Park. Those lakes span a gradient in fish-mercury concentrations, and also span gradients in other environmental variables that are thought to influence mercury cycling. During 2001, near surface methylmercury concentrations ranged from below the method detection limit of 0.04 nanograms per liter (ng/L) to 0.41 ng/L. Near surface total mercury concentrations ranged from 0.34 ng/L to 3.74 ng/L. Hypolimnetic methylmercury ranged from below detection to 2.69 ng/L, and hypolimnetic total mercury concentrations ranged from 0.34 ng/L to 7.16 ng/L. During 2002, near surface methylmercury concentrations ranged from below the method detection limit to 0.46 ng/L, and near surface total mercury ranged from 0.34 ng/L to 4.81 ng/L.

Contents and leachability of heavy metals (Pb, Cu, Sb, Zn, As) in soil at the Pantex firing range, Amarillo, Texas.

PubMed

Basunia, S; Landsberger, S

2001-10-01

Pantex firing range soil samples were analyzed for Pb, Cu, Sb, Zn, and As. One hundred ninety-seven samples were collected from the firing range and vicinity area. There was a lack of knowledge about the distribution of Pb in the firing range, so a random sampling with proportional allocation was chosen. Concentration levels of Pb and Cu in the firing range were found to be in the range of 11-4675 and 13-359 mg/kg, respectively. Concentration levels of Sb were found to be in the range of 1-517 mg/kg. However, the Zn and As concentration levels were close to average soil background levels. The Sn concentration level was expected to be higher in the Pantex firing range soil samples. However, it was found to be below the neutron activation analysis (NAA) detection limit of 75 mg/kg. Enrichment factor analysis showed that Pb and Sb were highly enriched in the firing range with average magnitudes of 55 and 90, respectively. Cu was enriched approximately 6 times more than the usual soil concentration levels. Toxicity characteristic leaching procedure (TCLP) was carried out on size-fractionated homogeneous soil samples. The concentration levels of Pb in leachates were found to be approximately 12 times higher than the U.S. Environmental Protection Agency (EPA) regulatory concentration level of 5 mg/L. Sequential extraction (SE) was also performed to characterize Pb and other trace elements into five different fractions. The highest Pb fraction was found with organic matter in the soil.

Equilibrium sorption and diffusion rate studies with halogenated organic chemical and sandy aquifer material

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

Ball, W.P.

1990-01-01

Concepts for rate limitation of sorptive uptake of hydrophobic organic solutes by aquifer solids are reviewed, emphasizing physical diffusion models and in the context of effects on contaminant transport. Data for the sorption of tetrachloroethene (PCE) and 1,2,4,5-tetrachlorobenzene (TeCB) on Borden sand are presented, showing that equilibrium is attained very slowly, requiring equilibration times on the order of tens of days for PCE and hundreds of days for TeCB. The rate of approach to equilibrium decreased with increasing particle size and sorption distribution coefficient, in accordance with retarded intragranular diffusion models. Pulverization of the samples significantly decreased the required timemore » to equilibrium without changing the sorption capacity of the solids. Batch sorption methodology was refined to allow accurate measurement of long-term distribution coefficients, using purified {sup 14}C-labelled solute spikes and sealed glass ampules. Sorption isotherms for PCE and TeCB were conducted with size fractions of Borden sand over four to five orders of magnitude in aqueous concentration, and were found to be slightly nonlinear (Freundlich exponent = 0.8). A concentrated set of data in the low concentration range (<50 ug/L) revealed that sorption in this range could be equally well described by a linear isotherm. Distribution coefficients of the two solutes with seven size fractions of Borden sand, measured at low concentration and at full equilibrium, were between seven and sixty times the value predicted on the basis of recent correlations with organic carbon content. Rate results for coarse size fractions support a simple pore diffusion model, with pore diffusion coefficients estimated to be approximately 3 {times} 10{sup {minus}8} cm{sup 2}/sec, more than 200{times} lower than the aqueous diffusivities.« less

Physiological concentrations of anabolic steroids in human hair.

PubMed

Shen, Min; Xiang, Ping; Shen, Baohua; Bu, Jun; Wang, Mengye

2009-01-30

Doping with endogenous anabolic steroids is one of the most serious issues in sports today. The measurement of anabolic steroid levels in human hair is necessary in order to distinguish between pharmaceutical steroids and natural steroids. This is the first investigation into the physiological concentrations of anabolic steroids in human hair in Chinese subjects. A gas chromatography-tandem mass spectrometry (GC/MS/MS) method was developed for the simultaneous identification and quantitation of five endogenous anabolic steroids (testosterone, epitestosterone, androsterone, etiocholanolone and dehydroepiandrosterone) in hair. After basic hydrolysis, hair samples were extracted with diethyl ether, derivatized and then detected using GC/MS/MS in the multiple-reaction monitoring mode (MRM). The one precursor/two product ion transitions for each anabolic steroid were monitored. The limits of detection for the five endogenous anabolic steroids were in the 0.1-0.2 pg/mg range. All analytes showed good linearity and the extraction recoveries were 74.6-104.5%. Within-day and between-day precisions were less than 20%. This method was applied to the analysis of testosterone, epitestosterone, androsterone, etiocholanolone, and dehydroepiandrosterone in human hair. Full-length hair samples were taken at the skin surface from the vertex of 39 males, 30 females and 11 children from China. None of the subjects were professional athletes. Testosterone and dehydroepiandrosterone were detected in all the hair segments. The physiological concentrations of testosterone were in the range 0.8-24.2 pg/mg, 0.1-16.8 pg/mg and 0.2-11.5 pg/mg in males, females and children, respectively, however, the mean values of dehydroepiandrosterone were much higher than the concentrations of testosterone. These data are suitable reference values and are the basis for the interpretation of results from investigations into the abuse of endogenous anabolic steroids.

Bioimmobilization of uranium-practical tools for field applications

NASA Astrophysics Data System (ADS)

Istok, J. D.

2011-12-01

Extensive laboratory and field research has conclusively demonstrated that it is possible to stimulate indigenous microbial activity and create conditions favorable for the reductive precipitation of uranium from groundwater, reducing aqueous U concentrations below regulatory levels. A wide variety of complex and coupled biogeochemical processes have been identified and specific reaction mechanisms and parameters have been quantified for a variety of experimental systems including pure, mixed, and natural microbial cultures, and single mineral, artificial, and natural sediments, and groundwater aquifers at scales ranging from very small (10s nm) to very large (10s m). Multicomponent coupled reactive transport models have also been developed to simulate various aspects of this process in 3D heterogeneous environments. Nevertheless, full-scale application of reductive bioimmobilization of uranium (and other radionuclides and metals) remains problematical because of the technical and logistical difficulties in creating and maintaining reducing environment in the many large U contaminated groundwater aquifers currently under aerobic and oxidizing conditions and often containing high concentrations of competing and more energetically favorable electron acceptors (esp. nitrate). This talk will discuss how simple tools, including small-scale in situ testing and geochemical reaction path modeling, can be used to quickly assess the feasibility of applying bioimmobilization to remediate U contaminated groundwater aquifers and provide data needed for full-scale design.

Process For Controlling Flow Rate Of Viscous Materials Including Use Of Nozzle With Changeable Openings

DOEpatents

Ellingson, William A.; Forster, George A.

1999-11-02

Apparatus and a method for controlling the flow rate of viscous materials through a nozzle includes an apertured main body and an apertured end cap coupled together and having an elongated, linear flow channel extending the length thereof. An end of the main body is disposed within the end cap and includes a plurality of elongated slots concentrically disposed about and aligned with the flow channel. A generally flat cam plate having a center aperture is disposed between the main body and end cap and is rotatable about the flow channel. A plurality of flow control vane assemblies are concentrically disposed about the flow channel and are coupled to the cam plate. Each vane assembly includes a vane element disposed adjacent the end of the flow channel. Rotation of the cam plate in a first direction causes a corresponding rotation of each of the vane elements for positioning the individual vane elements over the aperture in the end cap blocking flow through the flow channel, while rotation in an opposite direction removes the vane elements from the aperture and positions them about the flow channel in a nested configuration in the full open position, with a continuous range of vane element positions available between the full open and closed positions.

Pushing down the low-mass halo concentration frontier with the Lomonosov cosmological simulations

NASA Astrophysics Data System (ADS)

Pilipenko, Sergey V.; Sánchez-Conde, Miguel A.; Prada, Francisco; Yepes, Gustavo

2017-12-01

We introduce the Lomonosov suite of high-resolution N-body cosmological simulations covering a full box of size 32 h-1 Mpc with low-mass resolution particles (2 × 107 h-1 M⊙) and three zoom-in simulations of overdense, underdense and mean density regions at much higher particle resolution (4 × 104 h-1 M⊙). The main purpose of this simulation suite is to extend the concentration-mass relation of dark matter haloes down to masses below those typically available in large cosmological simulations. The three different density regions available at higher resolution provide a better understanding of the effect of the local environment on halo concentration, known to be potentially important for small simulation boxes and small halo masses. Yet, we find the correction to be small in comparison with the scatter of halo concentrations. We conclude that zoom simulations, despite their limited representativity of the volume of the Universe, can be effectively used for the measurement of halo concentrations at least at the halo masses probed by our simulations. In any case, after a precise characterization of this effect, we develop a robust technique to extrapolate the concentration values found in zoom simulations to larger volumes with greater accuracy. Altogether, Lomonosov provides a measure of the concentration-mass relation in the halo mass range 107-1010 h-1 M⊙ with superb halo statistics. This work represents a first important step to measure halo concentrations at intermediate, yet vastly unexplored halo mass scales, down to the smallest ones. All Lomonosov data and files are public for community's use.

Oxygen Transfer in Moving Bed Biofilm Reactor and Integrated Fixed Film Activated Sludge Processes.

PubMed

2017-11-17

A demonstrated approach to design the, so-called, medium-bubble air diffusion network for oxygen transfer into the aerobic zone(s) of moving bed biofilm reactor (MBBR) and integrated fixed-film activated sludge (IFAS) processes is described in this paper. Operational full-scale biological water resource recovery systems treating municipal sewerage demonstrate that medium-bubble air diffusion networks designed using the method presented here provide reliable service. Further improvement is possible, however, as knowledge gaps prevent more rational process designs. Filling such knowledge gaps can potentially result in higher performing and more economical systems. Small-scale system testing demonstrates significant enhancement of oxygen transfer capacity due to the presence of media, but quantification of such effects in full-scale systems is lacking, and is needed. Establishment of the relationship between diffuser submergence, aeration rate, and biofilm carrier fill fraction will enhance MBBR and IFAS aerobic process design, cost, and performance. Limited testing of full-scale systems is available to allow computation of alpha valuess. As with clean water testing of full-scale systems, further full-scale testing under actual operating conditions is required to more fully quantify MBBR and IFAS system oxygen transfer performance under a wide range of operating conditions. Control of MBBR and IFAS aerobic zone oxygen transfer systems can be optimized by recognizing that varying residual dissolved oxygen (DO) concentrations are needed, depending on operating conditions. For example, the DO concentration in the aerobic zone of nitrifying IFAS processes can be lowered during warm weather conditions when greater suspended growth nitrification can occur, resulting in the need for reduced nitrification by the biofilm compartment. Further application of oxygen transfer control approaches used in activated sludge systems to MBBR and IFAS systems, such as ammonia-based oxygen transfer system control, has been demonstrated to further improve MBBR and IFAS system energy-efficiency.

Lead accumulation in woodchucks (Marmota monax) at small arms and skeet ranges.

PubMed

Johnson, Mark S; Major, Michael A; Casteel, Stan W

2004-10-01

Increasing concern regarding the stewardship of US Army lands requires a proactive program to evaluate sites of potential risk. Small arms and upland skeet ranges are a potentially significant source of lead exposure for burrowing mammals. Woodchucks (Marmota monax) were evaluated for lead exposure in a previously used upland skeet range and a small arms range, respective to animals collected at two nearby reference locations. Soil lead concentrations collected at burrow entrances on the firing ranges were compared with blood, bone, kidney, liver, and fecal concentrations of woodchucks collected from the reference areas. No statistical differences were found in the lead concentrations in tissue between woodchucks in reference and firing ranges; concentrations of lead in liver and kidney were below detection limits. Levels in bone, blood, and feces suggest the bioavailability of lead at these various sites, although other factors (e.g., differences in foraging areas, age structure, habitat preferences, and environmental conditions) were also likely to influence exposure. Blood levels were below that which suggests toxicity. Further analysis of other ranges with higher lead concentrations and of small mammal species with smaller home ranges is recommended to further elucidate trends that could be extrapolated to other sites.

Acid mine drainage

USGS Publications Warehouse

Bigham, Jerry M.; Cravotta, Charles A.

2016-01-01

Acid mine drainage (AMD) consists of metal-laden solutions produced by the oxidative dissolution of iron sulfide minerals exposed to air, moisture, and acidophilic microbes during the mining of coal and metal deposits. The pH of AMD is usually in the range of 2–6, but mine-impacted waters at circumneutral pH (5–8) are also common. Mine drainage usually contains elevated concentrations of sulfate, iron, aluminum, and other potentially toxic metals leached from rock that hydrolyze and coprecipitate to form rust-colored encrustations or sediments. When AMD is discharged into surface waters or groundwaters, degradation of water quality, injury to aquatic life, and corrosion or encrustation of engineered structures can occur for substantial distances. Prevention and remediation strategies should consider the biogeochemical complexity of the system, the longevity of AMD pollution, the predictive power of geochemical modeling, and the full range of available field technologies for problem mitigation.

Biofiltration: an innovative air pollution control technology for VOC emissions.

PubMed

Leson, G; Winer, A M

1991-08-01

Biofiltration is a relatively recent air pollution control (APC) technology in which off-gases containing biodegradable volatile organic compounds (VOC) or inorganic air toxics are vented through a biologically active material. This technology has been successfully applied in Germany and The Netherlands in many full-scale applications to control odors, VOC and air toxic emissions from a wide range of industrial and public sector sources. Control efficiencies of more than 90 percent have been achieved for many common air pollutants. Due to lower operating costs, biofiltration can provide significant economic advantages over other APC technologies if applied to off-gases that contain readily biodegradable pollutants in low concentrations. Environmental benefits include low energy requirements and the avoidance of cross media transfer of pollutants. This paper reviews the history and current status of biofiltration, outlines its underlying scientific and engineering principles, and discusses the applicability of biofilters for a wide range of specific emission sources.

Characterization of exposure to byproducts from firing lead-free frangible ammunition in an enclosed, ventilated firing range.

PubMed

Grabinski, Christin M; Methner, Mark M; Jackson, Jerimiah M; Moore, Alexander L; Flory, Laura E; Tilly, Trevor; Hussain, Saber M; Ott, Darrin K

2017-06-01

U.S. Air Force small arms firing ranges began using copper-based, lead-free frangible ammunition in the early 2000s due to environmental and health concerns related to the use of lead-based ammunition. Exposure assessments at these firing ranges have routinely detected chemicals and metals in amounts much lower than their mass-based occupational exposure limits, yet, instructors report work-related health concerns including respiratory distress, nausea, and headache. The objective of this study at one firing range was to characterize the aerosol emissions produced by weapons during firing events and evaluate the ventilation system's effectiveness in controlling instructor exposure to these emissions. The ventilation system was assessed by measuring the range static air pressure differential and the air velocity at the firing line. Air flow patterns were near the firing line. Instructor exposure was sampled using a filter-based air sampling method for metals and a wearable, real-time ultrafine particle counter. Area air sampling was simultaneously performed to characterize the particle size distribution, morphology, and composition. In the instructor's breathing zone, the airborne mass concentration of copper was low (range = <1 µg/m 3 to 16 µg/m 3 ), yet the ultrafine (nanoscale) particle number concentration increased substantially during each firing event. Ultrafine particles contained some copper and were complex in morphology and composition. The ventilation assessment found that the average velocity across all shooting lanes was acceptable compared to the recommended guideline (20% of the ideal 0.38 m/s (75 ft/min). However, uniform, downrange airflow pattern requirements were not met. These results suggest that the mass-based occupational exposure limits, as applied to this environment, may not be protective enough to eliminate health complaints reported by instructors whose full-time job involves training personnel on weapons that fire lead-free frangible ammunition. Using an ultrafine particle counter appears to be an alternative method of assessing ventilation effectiveness in removing ultrafine particulate produced during firing events.

Evaluation of an artificial intelligence program for estimating occupational exposures.

PubMed

Johnston, Karen L; Phillips, Margaret L; Esmen, Nurtan A; Hall, Thomas A

2005-03-01

Estimation and Assessment of Substance Exposure (EASE) is an artificial intelligence program developed by UK's Health and Safety Executive to assess exposure. EASE computes estimated airborne concentrations based on a substance's vapor pressure and the types of controls in the work area. Though EASE is intended only to make broad predictions of exposure from occupational environments, some occupational hygienists might attempt to use EASE for individual exposure characterizations. This study investigated whether EASE would accurately predict actual sampling results from a chemical manufacturing process. Personal breathing zone time-weighted average (TWA) monitoring data for two volatile organic chemicals--a common solvent (toluene) and a specialty monomer (chloroprene)--present in this manufacturing process were compared to EASE-generated estimates. EASE-estimated concentrations for specific tasks were weighted by task durations reported in the monitoring record to yield TWA estimates from EASE that could be directly compared to the measured TWA data. Two hundred and six chloroprene and toluene full-shift personal samples were selected from eight areas of this manufacturing process. The Spearman correlation between EASE TWA estimates and measured TWA values was 0.55 for chloroprene and 0.44 for toluene, indicating moderate predictive values for both compounds. For toluene, the interquartile range of EASE estimates at least partially overlapped the interquartile range of the measured data distributions in all process areas. The interquartile range of EASE estimates for chloroprene fell above the interquartile range of the measured data distributions in one process area, partially overlapped the third quartile of the measured data in five process areas and fell within the interquartile range in two process areas. EASE is not a substitute for actual exposure monitoring. However, EASE can be used in conditions that cannot otherwise be sampled and in preliminary exposure assessment if it is recognized that the actual interquartile range could be much wider and/or offset by a factor of 10 or more.

Hydration and ion pair formation in aqueous Y(3+)-salt solutions.

PubMed

Rudolph, Wolfram W; Irmer, Gert

2015-11-14

Raman spectra of aqueous yttrium perchlorate, triflate (trifluoromethanesulfonate), chloride and nitrate solutions were measured over a broad concentration range (0.198-3.252 mol L(-1)). The spectra range from low wavenumbers to 4200 cm(-1). A very weak mode at 384 cm(-1) with a full width at half height at 50 cm(-1) in the isotropic spectrum suggests that the Y(3+)- octa-aqua ion is thermodynamically stable in dilute perchlorate solutions (∼0.5 mol L(-1)) while in concentrated perchlorate solutions outer-sphere ion pairs and contact ion pairs are formed. The octa-hydrate, [Y(OH2)8](3+) was also detected in a 1.10 mol L(-1) aqueous Y(CF3SO3)3 solution. Furthermore, very weak and broad depolarized modes could be detected which are assigned to [Y(OH2)8](3+)(aq) at 100, 166, 234 and 320 cm(-1) confirming that a hexa-hydrate is not compatible with the hydrated species in solution. In yttrium chloride solutions contact ion pair formation was detected over the measured concentration range from 0.479-3.212 mol L(-1). The contact ion pairs in YCl3(aq) are fairly weak and disappear with dilution. At a concentration <0.2 mol L(-1) almost all complexes have disappeared. In YCl3 solutions, with additional HCl, chloro-complexes of the type [Y(OH2)8-nCln](+3-n) (n = 1,2) are formed. The Y(NO3)3(aq) spectra were compared with a spectrum of a dilute NaNO3 solution and it was concluded that in Y(NO3)3(aq) over the concentration range from 2.035-0.198 mol L(-1) nitrato-complexes [Y(OH2)8-n(NO3)ln](+3-n) (n = 1,2) are formed. The nitrato-complexes are weak and disappear with dilution <0.1 mol L(-1). DFT geometry optimizations and frequency calculations are reported for both the yttrium-water cluster in the gas phase and the cluster within a polarizable continuum model in order to implicitly describe the presence of the bulk solvent. The bond distance and angle for the square antiprismatic cluster geometry of [Y(OH2)8](3+) with the polarizable dielectric continuum is in good agreement with data from recent structural experimental measurements. The DFT frequency of the Y-O stretching mode of the [Y(OH2)8](3+) cluster, in a polarizable continuum, is at 372 cm(-1) in satisfactory agreement with the experimental value.

Full Range Advising: Transforming the Advisor-Advisee Experience

ERIC Educational Resources Information Center

Barbuto, John E., Jr.; Story, Joana S.; Fritz, Susan M.; Schinstock, Jack L.

2011-01-01

Drawing from the leadership literature, a new model for advising is proposed. Full range advising encompasses laissez-faire, management by exception, contingent rewards, and transformational behaviors. The relationships between full range advising and advisees' extra effort, satisfaction with the advisor, and advising effectiveness were examined.…

Water quality of Somerville Lake, south-central Texas

USGS Publications Warehouse

McPherson, Emma; Mendieta, H.B.

1983-01-01

The concentration of dissolved solids ranged from 139 to 292 milligrams per liter and averaged about 220 milligrams per liter. Dissolved chloride concentrations ranged from 20 to 68 milligrams per liter and averaged 43 milligrams per liter. Dissolved sulfate concentrations ranged from 30 to 130 milligrams per liter and averaged 63 milligrams per liter. The total hardness of the water ranged from 75 to 140 milligrams per liter, expressed as calcium carbonate, placing it in the moderately hard to hard (61 to 180 milligrams per liter) classification. The concentrations of principal dissolved constituents indicate that Somerville Lake is an excellent source of water for municipal, industrial, or agricultural use.

Laboratory methodologies for indicators of iron status: strengths, limitations, and analytical challenges.

PubMed

Pfeiffer, Christine M; Looker, Anne C

2017-12-01

Biochemical assessment of iron status relies on serum-based indicators, such as serum ferritin (SF), transferrin saturation, and soluble transferrin receptor (sTfR), as well as erythrocyte protoporphyrin. These indicators present challenges for clinical practice and national nutrition surveys, and often iron status interpretation is based on the combination of several indicators. The diagnosis of iron deficiency (ID) through SF concentration, the most commonly used indicator, is complicated by concomitant inflammation. sTfR concentration is an indicator of functional ID that is not an acute-phase reactant, but challenges in its interpretation arise because of the lack of assay standardization, common reference ranges, and common cutoffs. It is unclear which indicators are best suited to assess excess iron status. The value of hepcidin, non-transferrin-bound iron, and reticulocyte indexes is being explored in research settings. Serum-based indicators are generally measured on fully automated clinical analyzers available in most hospitals. Although international reference materials have been available for years, the standardization of immunoassays is complicated by the heterogeneity of antibodies used and the absence of physicochemical reference methods to establish "true" concentrations. From 1988 to 2006, the assessment of iron status in NHANES was based on the multi-indicator ferritin model. However, the model did not indicate the severity of ID and produced categorical estimates. More recently, iron status assessment in NHANES has used the total body iron stores (TBI) model, in which the log ratio of sTfR to SF is assessed. Together, sTfR and SF concentrations cover the full range of iron status. The TBI model better predicts the absence of bone marrow iron than SF concentration alone, and TBI can be analyzed as a continuous variable. Additional consideration of methodologies, interpretation of indicators, and analytic standardization is important for further improvements in iron status assessment. © 2017 American Society for Nutrition.

The distribution of methylated sulfur compounds, DMS and DMSP, in Canadian subarctic and Arctic marine waters during summer 2015

NASA Astrophysics Data System (ADS)

Jarníková, Tereza; Dacey, John; Lizotte, Martine; Levasseur, Maurice; Tortell, Philippe

2018-04-01

We present seawater concentrations of dimethyl sulfide (DMS) and dimethylsulfoniopropionate (DMSP) measured across a transect from the Labrador Sea to the Canadian Arctic Archipelago during summer 2015. Using an automated ship-board gas chromatography system and a membrane-inlet mass spectrometer, we measured a wide range of DMS (˜ 1 to 18 nM) and DMSP (˜ 1 to 150 nM) concentrations. The highest DMS and DMSP concentrations occurred in a localized region of Baffin Bay, where surface waters were characterized by high chlorophyll a (chl a) fluorescence, indicative of elevated phytoplankton biomass. Across the full sampling transect, there were only weak relationships between DMS(P), chl a fluorescence and other measured variables, including positive relationships between DMSP : chl a ratios and several taxonomic marker pigments, and elevated DMS(P) concentrations in partially ice-covered areas. Our high spatial resolution measurements allowed us to examine DMS variability over small scales (< 1 km), documenting strong DMS concentration gradients across surface hydrographic frontal features. Our new observations fill in an important observational gap in the Arctic Ocean and provide additional information on sea-air DMS fluxes from this ocean region. In addition, this study constitutes a significant contribution to the existing Arctic DMS(P) dataset and provides a baseline for future measurements in the region.

Haematological studies on vegans.

PubMed

Sanders, T A; Ellis, F R; Dickerson, J W

1978-07-01

1. The concentrations of vitamin B12 and folate in the serum and folate in the erythrocytes were determined and full blood counts made on a series of caucasian vegans and omnivore controls. 2. The blood counts and films were normal in all the vegans and no subject had a haemoblobin concentration below the lower limit of normality. 3. Although within the normal range, male but not female vegans had lower values for erythrocyte counts and higher values for mean corpuscular volume and mean corpuscular haemoglobin than their controls regardless of whether they were taking vitamin B12 supplements or not. 4. The mean serum vitamin B12 concentration was lower in the vegans not taking vitamin B12 supplements and in those using foods supplemented with the vitamin than in the controls, but in no subject was it below 80 ng/1. 5. The serum folate concentrations were higher in the vegans than in their controls. The mean value for erythrocyte folate tended to be greater in the vegans not taking vitamin B12 supplements. No subject had an erythrocyte folate concentration of less than 100 microgram/1. 6. It is concluded that megaloblastic anaemia is very rare in caucasian vegans and that a diet consisting entirely of plant foods is generally adequate to promote normal blood formation providing it is composed of a mixture of unrefined cereals, pulses, nuts, fruit and vegetables and is supplemented with vitamin B12.

Materials for Concentrator Photovoltaic Systems: Optical Properties and Solar Radiation Durability

NASA Astrophysics Data System (ADS)

French, R. H.; Rodríguez-Parada, J. M.; Yang, M. K.; Lemon, M. F.; Romano, E. C.; Boydell, P.

2010-10-01

Concentrator photovoltaic (CPV) systems are designed to operate over a wide range of solar concentrations, from low concentrations of ˜1 to 12 Suns to medium concentrations in the range from 12 to 200 Suns, to high concentration CPV systems going up to 2000 Suns. Many transparent optical materials are used for a wide variety of functions ranging from refractive and reflective optics to homogenizers, encapsulants and even thermal management. The classes of materials used also span a wide spectrum from hydrocarbon polymers (HCP) and fluoropolymers (FP) to silicon containing polymers and polyimides (PI). The optical properties of these materials are essential to the optical behavior of the system. At the same time radiation durability of these materials under the extremely wide range of solar concentrations is a critical performance requirement for the required lifetime of a CPV system. As part of our research on materials for CPV we are evaluating the optical properties and solar radiation durability of various polymeric materials to define the optimum material combinations for various CPV systems.

Evaluation of various carbon blacks and dispersing agents for use in the preparation of uranium microspheres with carbon

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

Hunt, Rodney Dale; Johnson, Jared A.; Collins, Jack Lee

A comparison study on carbon blacks and dispersing agents was performed to determine their impacts on the final properties of uranium fuel kernels with carbon. The main target compositions in this internal gelation study were 10 and 20 mol % uranium dicarbide (UC 2), which is UC 1.86, with the balance uranium dioxide. After heat treatment at 1900 K in flowing carbon monoxide in argon for 12 h, the density of the kernels produced using a X-energy proprietary carbon suspension, which is commercially available, ranged from 96% to 100% of theoretical density (TD), with full conversion of UC to UCmore » 2 at both carbon concentrations. However, higher carbon concentrations such as a 2.5 mol ratio of carbon to uranium in the feed solutions failed to produce gel spheres with the proprietary carbon suspension. The kernels using our former baseline of Mogul L carbon black and Tamol SN were 90–92% of TD with full conversion of UC to UC 2 at a variety of carbon levels. Raven 5000 carbon black and Tamol SN were used to produce 10 mol % UC2 kernels with 95% of TD. However, an increase in the Raven 5000 concentration led to a kernel density below 90% of TD. Raven 3500 carbon black and Tamol SN were used to make very dense kernels without complete conversion to UC 2. Lastly, the selection of the carbon black and dispersing agent is highly dependent on the desired final properties of the target kernels.« less

Evaluation of various carbon blacks and dispersing agents for use in the preparation of uranium microspheres with carbon

NASA Astrophysics Data System (ADS)

Hunt, R. D.; Johnson, J. A.; Collins, J. L.; McMurray, J. W.; Reif, T. J.; Brown, D. R.

2018-01-01

A comparison study on carbon blacks and dispersing agents was performed to determine their impacts on the final properties of uranium fuel kernels with carbon. The main target compositions in this internal gelation study were 10 and 20 mol % uranium dicarbide (UC2), which is UC1.86, with the balance uranium dioxide. After heat treatment at 1900 K in flowing carbon monoxide in argon for 12 h, the density of the kernels produced using a X-energy proprietary carbon suspension, which is commercially available, ranged from 96% to 100% of theoretical density (TD), with full conversion of UC to UC2 at both carbon concentrations. However, higher carbon concentrations such as a 2.5 mol ratio of carbon to uranium in the feed solutions failed to produce gel spheres with the proprietary carbon suspension. The kernels using our former baseline of Mogul L carbon black and Tamol SN were 90-92% of TD with full conversion of UC to UC2 at a variety of carbon levels. Raven 5000 carbon black and Tamol SN were used to produce 10 mol % UC2 kernels with 95% of TD. However, an increase in the Raven 5000 concentration led to a kernel density below 90% of TD. Raven 3500 carbon black and Tamol SN were used to make very dense kernels without complete conversion to UC2. The selection of the carbon black and dispersing agent is highly dependent on the desired final properties of the target kernels.

Atmospheric CO2 Concentration Measurements with Clouds from an Airborne Lidar

NASA Astrophysics Data System (ADS)

Mao, J.; Abshire, J. B.; Kawa, S. R.; Riris, H.; Allan, G. R.; Hasselbrack, W. E.; Numata, K.; Chen, J. R.; Sun, X.; DiGangi, J. P.; Choi, Y.

2017-12-01

Globally distributed atmospheric CO2 concentration measurements with high precision, low bias and full seasonal sampling are crucial to advance carbon cycle sciences. However, two thirds of the Earth's surface is typically covered by clouds, and passive remote sensing approaches from space are limited to cloud-free scenes. NASA Goddard is developing a pulsed, integrated-path differential absorption (IPDA) lidar approach to measure atmospheric column CO2 concentrations, XCO2, from space as a candidate for NASA's ASCENDS mission. Measurements of time-resolved laser backscatter profiles from the atmosphere also allow this technique to estimate XCO2 and range to cloud tops in addition to those to the ground with precise knowledge of the photon path-length. We demonstrate this measurement capability using airborne lidar measurements from summer 2017 ASCENDS airborne science campaign in Alaska. We show retrievals of XCO2 to ground and to a variety of cloud tops. We will also demonstrate how the partial column XCO2 to cloud tops and cloud slicing approach help resolving vertical and horizontal gradient of CO2 in cloudy conditions. The XCO2 retrievals from the lidar are validated against in situ measurements and compared to the Goddard Parameterized Chemistry Transport Model (PCTM) simulations. Adding this measurement capability to the future lidar mission for XCO2 will provide full global and seasonal data coverage and some information about vertical structure of CO2. This unique facility is expected to benefit atmospheric transport process studies, carbon data assimilation in models, and global and regional carbon flux estimation.

Evaluation of various carbon blacks and dispersing agents for use in the preparation of uranium microspheres with carbon

DOE PAGES

Hunt, Rodney Dale; Johnson, Jared A.; Collins, Jack Lee; ...

2017-10-12

A comparison study on carbon blacks and dispersing agents was performed to determine their impacts on the final properties of uranium fuel kernels with carbon. The main target compositions in this internal gelation study were 10 and 20 mol % uranium dicarbide (UC 2), which is UC 1.86, with the balance uranium dioxide. After heat treatment at 1900 K in flowing carbon monoxide in argon for 12 h, the density of the kernels produced using a X-energy proprietary carbon suspension, which is commercially available, ranged from 96% to 100% of theoretical density (TD), with full conversion of UC to UCmore » 2 at both carbon concentrations. However, higher carbon concentrations such as a 2.5 mol ratio of carbon to uranium in the feed solutions failed to produce gel spheres with the proprietary carbon suspension. The kernels using our former baseline of Mogul L carbon black and Tamol SN were 90–92% of TD with full conversion of UC to UC 2 at a variety of carbon levels. Raven 5000 carbon black and Tamol SN were used to produce 10 mol % UC2 kernels with 95% of TD. However, an increase in the Raven 5000 concentration led to a kernel density below 90% of TD. Raven 3500 carbon black and Tamol SN were used to make very dense kernels without complete conversion to UC 2. Lastly, the selection of the carbon black and dispersing agent is highly dependent on the desired final properties of the target kernels.« less

Performance and application of a fluidized bed limestone reactor designed for control of alkalinity, hardness and pH at the Warm Springs Regional Fisheries Center

USGS Publications Warehouse

Watten, Barnaby J.; Mudrak, Vincent A.; Echevarria, Carlos; Sibrell, Philip; Summerfelt, Steven T.; Boyd, Claude E.

2017-01-01

Springs serving the Warm Springs Regional Fisheries Center, Warm Springs, Georgia, have pH, alkalinity, and hardness levels thatlie under the range required for successful fish propagation while free CO2 is well above allowable targets. We evaluate a pretreatment process that exploits limestone’s (CaCO3) ability to react away hydrogen ions (H+) and carbon dioxide (CO2) while increasing alkalinity (HCO3−) and calcium (Ca2+) concentrations, i.e. CaCO3 + H+ ↔ HCO3− + Ca2+ CaCO3 + CO2 + H2O ↔ Ca2+ + 2HCO3− Limestone sand was tested in both pilot and full scale fluidized bed reactors (CycloBio®). We first established the bed expansion characteristics of three commercial limestone products then evaluated the effect of hydraulic flux and bed height on dissolution rate of a single selected product (Type A16 × 120). Pilot scale testing at 18C showed limestone dissolution rates were relatively insensitive to flux over the range 1.51–3.03 m3/min/m2 but were sensitive (P < 0.001; R2 = 0.881) to changes in bed height (BH, cm) over the range 83–165 cm following the relation: (Alkalinity, mg/L) = 123.51 − (3788.76 (BH)). Differences between filtered and non-filtered alkalinity were small(P > 0.05) demonstrating that limestone was present in the reactor effluent primarily in the form of dissolved Ca(HCO3)2. Effluent alkalinity exceeded our target level of 50 mg/L under most operating conditions evaluated with typical pilot scale values falling within the range of 90–100 mg/L despite influent concentrations of about 4 mg/L. Concurrently, CO2 fell from an average of 50.6 mg/L to 8.3 mg/L (90%), providing for an increase in pH from 5.27 to a mean of 7.71. The ability of the test reactor to provide changes in water chemistry variables that exceeded required changes allowed for a dilution ratio of 0.6. Here, alkalinity still exceeded 50 mg/L, the CO2 concentration remained well below our limit of 20 mg/L (15.4 mg/L) and the pH was near neutral (7.17). Applying the dilution ratio of 0.6 in a full scale treatment plant at the site reduced by 40% the volume of spring water that is directed through each of three parallel reactors that combined react away 49,000 kg of limestone/yr.

Methods of analysis by the U.S. Geological Survey National Water Quality Laboratory : determination of polycyclic aromatic hydrocarbon compounds in sediment by gas chromatography/mass spectrometry

USGS Publications Warehouse

Olson, Mary C.; Iverson, Jana L.; Furlong, Edward T.; Schroeder, Michael P.

2004-01-01

A method for the determination of 28 polycyclic aromatic hydrocarbons (PAHs) and 25 alkylated PAH homolog groups in sediment samples is described. The compounds are extracted from sediment by solvent extraction, followed by partial isolation using high-performance gel permeation chromatography. The compounds are identified and uantitated using capillary-column gas chromatography/mass spectrometry. The report presents performance data for full-scan ion monitoring. Method detection limits in laboratory reagent matrix samples range from 1.3 to 5.1 micrograms per kilogram for the 28 PAHs. The 25 groups of alkylated PAHs are homologs of five groups of isomeric parent PAHs. Because of the lack of authentic standards, these homologs are reported semiquantitatively using a response factor from a parent PAH or a specific alkylated PAH. Precision data for the alkylated PAH homologs are presented using two different standard reference manuals produced by the National Institute of Standards and Technology: SRM 1941b and SRM 1944. The percent relative standard deviations for identified alkylated PAH homolog groups ranged from 1.55 to 6.98 for SRM 1941b and from 6.11 to 12.0 for SRM 1944. Homolog group concentrations reported under this method include the concentrations of individually identified compounds that are members of the group. Organochlorine (OC) pesticides--including toxaphene, polychlorinated biphenyls (PCBs), and organophosphate (OP) pesticides--can be isolated simultaneously using this method. In brief, sediment samples are centrifuged to remove excess water and extracted overnight with dichloromethan (95 percent) and methanol (5 percent). The extract is concentrated and then filtered through a 0.2-micrometer polytetrafluoroethylene syringe filter. The PAH fraction is isolated by quantitatively injecting an aliquot of sample onto two polystyrene-divinylbenzene gel-permeation chromatographic columns connected in series. The compounds are eluted with dichloromethane, a PAH fraction is collected, and a portion of the coextracted interferences, including elemental sulfur, is separated and discarded. The extract is solvent exchanged, the volume is reduced, and internal standard is added. Sample analysis is completed using a gas chromatograph/mass spectrometer and full-scan acquisition.

Anisotropic In Situ-Coated AuNPs on Screen-Printed Carbon Surface for Enhanced Prostate-Specific Antigen Impedimetric Aptasensor

NASA Astrophysics Data System (ADS)

Do, Tram T. N.; Van Phi, Toan; Nguy, Tin Phan; Wagner, Patrick; Eersels, Kasper; Vestergaard, Mun'delanji C.; Truong, Lien T. N.

2017-06-01

An impedimetric aptasensor has been used to study the effect of charge transfer on the binding of prostate-specific antigen (PSA) to its aptamer. Full understanding of this mechanism will be beneficial to further improve its sensitivity for PSA detection in human semen at physiologically relevant concentrations. Bare gold electrodes (SPAuEs) and gold nanoparticles (AuNPs)-coated screen-printed carbon ink electrodes (AuNPs/SPCEs) were coated with aptamer solution at various concentrations and the sensor response to increasing PSA concentration in buffer solution examined. AuNPs were deposited onto carbon electrodes in 10 cycles. AuNPs/SPCEs were then coated with a self-assembled monolayer (SAM) of 16-mercaptohexadecanoic acid prior to aptamer immobilization at dose of 5 μg mL-1. The results indicate that anisotropic AuNPs/SPCEs outperform bare gold electrodes in terms of decreased amount of aptamer bunches as well as the number of intermediate PSA-aptamer complexes formed on the electrode surface. The key finding is that the fabricated aptasensor is sensitive enough [limit of detection (LoD) 1.95 ng mL-1] for early diagnosis of prostate cancer and displays linear response in the physiologically relevant concentration range (0 ng mL-1 to 10 ng mL-1), as shown by the calibration curve of the relative change in electron transfer resistance (Δ R CT) versus PSA concentration when aptamer/SAM/AuNPs/SPCEs were exposed to buffer containing PSA at different concentrations.

A hybrid model for predicting carbon monoxide from vehicular exhausts in urban environments

NASA Astrophysics Data System (ADS)

Gokhale, Sharad; Khare, Mukesh

Several deterministic-based air quality models evaluate and predict the frequently occurring pollutant concentration well but, in general, are incapable of predicting the 'extreme' concentrations. In contrast, the statistical distribution models overcome the above limitation of the deterministic models and predict the 'extreme' concentrations. However, the environmental damages are caused by both extremes as well as by the sustained average concentration of pollutants. Hence, the model should predict not only 'extreme' ranges but also the 'middle' ranges of pollutant concentrations, i.e. the entire range. Hybrid modelling is one of the techniques that estimates/predicts the 'entire range' of the distribution of pollutant concentrations by combining the deterministic based models with suitable statistical distribution models ( Jakeman, et al., 1988). In the present paper, a hybrid model has been developed to predict the carbon monoxide (CO) concentration distributions at one of the traffic intersections, Income Tax Office (ITO), in the Delhi city, where the traffic is heterogeneous in nature and meteorology is 'tropical'. The model combines the general finite line source model (GFLSM) as its deterministic, and log logistic distribution (LLD) model, as its statistical components. The hybrid (GFLSM-LLD) model is then applied at the ITO intersection. The results show that the hybrid model predictions match with that of the observed CO concentration data within the 5-99 percentiles range. The model is further validated at different street location, i.e. Sirifort roadway. The validation results show that the model predicts CO concentrations fairly well ( d=0.91) in 10-95 percentiles range. The regulatory compliance is also developed to estimate the probability of exceedance of hourly CO concentration beyond the National Ambient Air Quality Standards (NAAQS) of India. It consists of light vehicles, heavy vehicles, three- wheelers (auto rickshaws) and two-wheelers (scooters, motorcycles, etc).

Laser-directed 3D assembly of carbon nanotubes using two-photon polymerization (Conference Presentation)

NASA Astrophysics Data System (ADS)

Liu, Ying; Xiong, Wei; Jiang, Li Jia; Zhou, Yunshen; Li, Dawei; Jiang, Lan; Silvain, Jean-Francois; Lu, Yongfeng

2017-02-01

Precise assembly of carbon nanotubes (CNTs) in arbitrary 3D space with proper alignment is critically important and desirable for CNT applications but still remains as a long-standing challenge. Using the two-photon polymerization (TPP) technique, it is possible to fabricate 3D micro/nanoscale CNT/polymer architectures with proper CNT alignments in desired directions, which is expected to enable a broad range of applications of CNTs in functional devices. To unleash the full potential of CNTs, it is strategically important to develop TPP-compatible resins with high CNT concentrations for precise assembly of CNTs into 3D micro/nanostructures for functional device applications. We investigated a thiol grafting method in functionalizing multiwalled carbon nanotubes (MWNTs) to develop TPP-compatible MWNT-thiol-acrylate (MTA) composite resins. The composite resins developed had high MWNT concentrations up to 0.2 wt%, over one order of magnitude higher than previously published work. Significantly enhanced electrical and mechanical properties of the 3D micro/nanostructures were achieved. Precisely controlled MWNT assembly and strong anisotropic effects were confirmed. Microelectronic devices made of the MTA composite polymer were demonstrated. The nanofabrication method can achieve controlled assembly of MWNTs in 3D micro/nanostructures, enabling a broad range of CNT applications, including 3D electronics, integrated photonics, and micro/nanoelectromechanical systems (MEMS/NEMS).

Holographic lens spectrum splitting photovoltaic system for increased diffuse collection and annual energy yield

NASA Astrophysics Data System (ADS)

Vorndran, Shelby D.; Wu, Yuechen; Ayala, Silvana; Kostuk, Raymond K.

2015-09-01

Concentrating and spectrum splitting photovoltaic (PV) modules have a limited acceptance angle and thus suffer from optical loss under off-axis illumination. This loss manifests itself as a substantial reduction in energy yield in locations where a significant portion of insulation is diffuse. In this work, a spectrum splitting PV system is designed to efficiently collect and convert light in a range of illumination conditions. The system uses a holographic lens to concentrate shortwavelength light onto a smaller, more expensive indium gallium phosphide (InGaP) PV cell. The high efficiency PV cell near the axis is surrounded with silicon (Si), a less expensive material that collects a broader portion of the solar spectrum. Under direct illumination, the device achieves increased conversion efficiency from spectrum splitting. Under diffuse illumination, the device collects light with efficiency comparable to a flat-panel Si module. Design of the holographic lens is discussed. Optical efficiency and power output of the module under a range of illumination conditions from direct to diffuse are simulated with non-sequential raytracing software. Using direct and diffuse Typical Metrological Year (TMY3) irradiance measurements, annual energy yield of the module is calculated for several installation sites. Energy yield of the spectrum splitting module is compared to that of a full flat-panel Si reference module.

Extraction Optimization for Obtaining Artemisia capillaris Extract with High Anti-Inflammatory Activity in RAW 264.7 Macrophage Cells

PubMed Central

Jang, Mi; Jeong, Seung-Weon; Kim, Bum-Keun; Kim, Jong-Chan

2015-01-01

Plant extracts have been used as herbal medicines to treat a wide variety of human diseases. We used response surface methodology (RSM) to optimize the Artemisia capillaris Thunb. extraction parameters (extraction temperature, extraction time, and ethanol concentration) for obtaining an extract with high anti-inflammatory activity at the cellular level. The optimum ranges for the extraction parameters were predicted by superimposing 4-dimensional response surface plots of the lipopolysaccharide- (LPS-) induced PGE2 and NO production and by cytotoxicity of A. capillaris Thunb. extracts. The ranges of extraction conditions used for determining the optimal conditions were extraction temperatures of 57–65°C, ethanol concentrations of 45–57%, and extraction times of 5.5–6.8 h. On the basis of the results, a model with a central composite design was considered to be accurate and reliable for predicting the anti-inflammation activity of extracts at the cellular level. These approaches can provide a logical starting point for developing novel anti-inflammatory substances from natural products and will be helpful for the full utilization of A. capillaris Thunb. The crude extract obtained can be used in some A. capillaris Thunb.-related health care products. PMID:26075271

Activation of Cyclic AMP Synthesis by Full and Partial Beta-Adrenergic Receptor Agonists in Chicken Skeletal Muscle Cells

NASA Technical Reports Server (NTRS)

Young, R. B.; Bridge, K. Y.; Cureri, Peter A. (Technical Monitor)

2002-01-01

Several beta-adrenergic receptor (bAR) agonists are known to cause hypertrophy of skeletal muscle tissue. Accordingly, five bAR agonists encompassing a range in activity from strong to weak were evaluated for their ability to stimulate cAMP accumulation in embryonic chicken skeletal muscle cells in culture. Two strong agonists (epinephrine and isoproterenol), one moderate agonist (albuterol), and two weak agonists known to cause hypertrophy in animals (clenbuterol and cimaterol) were studied. Dose response curves were determined over six orders of magnitude in concentration for each agonist, and values were determined for their maximum stimulation of cAMP synthesis rate (Bmax) and the agonist concentration at which 50% stimulation of cAMP synthesis (EC50) occurred. Bmax values decreased in the following order: isoproterenol, epinephrine, albuterol, cimaterol, clenbuterol. Cimaterol and clenbuterol at their Bmax concentrations were approximately 15-fold weaker than isoproterenol in stimulating the rate of cAMP synthesis. When cimaterol and clenbuterol were added to culture media at concentrations known to cause significant muscle hypertrophy in animals, there was no detectable effect on stimulation of cAMP synthesis. Finally, these same levels of cimaterol and clenbuterol did not antagonize the stimulation of cAMP by either epinephrine or isoproterenol.

Connecting the Dots: Responses of Coastal Ecosystems to Changing Nutrient Concentrations

PubMed Central

2011-01-01

Empirical relationships between phytoplankton biomass and nutrient concentrations established across a wide range of different ecosystems constitute fundamental quantitative tools for predicting effects of nutrient management plans. Nutrient management plans based on such relationships, mostly established over trends of increasing rather than decreasing nutrient concentrations, assume full reversibility of coastal eutrophication. Monitoring data from 28 ecosystems located in four well-studied regions were analyzed to study the generality of chlorophyll a versus nutrient relationships and their applicability for ecosystem management. We demonstrate significant differences across regions as well as between specific coastal ecosystems within regions in the response of chlorophyll a to changing nitrogen concentrations. We also show that the chlorophyll a versus nitrogen relationships over time constitute convoluted trajectories rather than simple unique relationships. The ratio of chlorophyll a to total nitrogen almost doubled over the last 30–40 years across all regions. The uniformity of these trends, or shifting baselines, suggest they may result from large-scale changes, possibly associated with global climate change and increasing human stress on coastal ecosystems. Ecosystem management must, therefore, develop adaptation strategies to face shifting baselines and maintain ecosystem services at a sustainable level rather than striving to restore an ecosystem state of the past. PMID:21958109

Cholesterol values in free-ranging gorillas (Gorilla gorilla gorilla and Gorilla beringei) and Bornean orangutans (Pongo pygmaeus).

PubMed

Schmidt, Debra A; Ellersieck, Mark R; Cranfield, Michael R; Karesh, William B

2006-09-01

Cholesterol concentrations in captive gorillas and orangutans vary widely within species and average approximately 244 mg/dl for gorillas and 169 mg/dl for orangutans as published previously. The International Species Inventory System reports higher concentrations of 275 and 199 mg/dl for gorillas and orangutans, respectively. It is unknown whether these values were typical, influenced by captive management, or both. To answer this question, banked serum samples from free-ranging mountain gorillas (Gorilla beringei), western lowland gorillas (Gorilla gorilla gorilla), and Bornean orangutans (Pongo pygmaeus) were analyzed for total cholesterol, triglyceride, high-density lipoprotein cholesterol, and low-density lipoprotein cholesterol concentrations. Mountain gorillas did not differ significantly from free-ranging western lowland gorillas in cholesterol, triglyceride, high-density lipoprotein cholesterol, or low-density lipoprotein cholesterol concentrations, indicating mountain gorilla values could be a model for western lowland gorillas. Captive gorilla total cholesterol and low-density lipoprotein cholesterol concentrations were significantly higher (P < 0.05) than in free-ranging groups. Triglyceride concentrations for captive gorillas were significantly higher (P < 0.05) than the male mountain and western lowland gorillas, but they were not significantly different from the female mountain gorillas. Captive orangutan total cholesterol concentrations were only higher (P < 0.05) than the free-ranging female orangutans, whereas captive orangutan low-density lipoprotein cholesterol concentrations were significantly higher (P < 0.05) than both free-ranging male and female orangutans. Calculated and measured low-density lipoprotein cholesterol concentrations were compared for all free-ranging animals and were significantly different (P < 0.05) for all groups, indicating Friedewald's equation for calculating low-density lipoprotein cholesterol is not appropriate for use with nonfasted apes. The higher total cholesterol and low-density lipoprotein cholesterol concentrations in captive apes may predispose them to cardiovascular disease and might be attributed to diets, limited energy expenditure, and genetics.

Final Report One-Twelfth-Scale Mixing Experiments to Characterize Double-Shell Tank Slurry Uniformity

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

Bamberger, Judith A.; Liljegren, Lucia M.; Enderlin, Carl W.

The objectives of these 1/12-scale scoping experiments were to: Determine which of the dimensionless parameters discussed in Bamberger and Liljegren (1994) affect the maximum concentration that can be suspended during jet mixer pump operation in the full-scale double-shell tanks; Develop empirical correlations to predict the nozzle velocity required for jet mixer pumps to suspend the contents of full-scale double-shell tanks; Apply the models to predict the nozzle velocity required to suspend the contents of Tank 241 AZ-101; Obtain experimental concentration data to compare with the TEMPEST( )(Trent and Eyler 1989) computational modeling predictions to guide further code development; Analyze themore » effects of changing nozzle diameter on exit velocity (U0) and U0D0 (the product of the exit velocity and nozzle diameter) required to suspend the contents of a tank. The scoping study experimentally evaluated uniformity in a 1/12-scale experiment varying the Reynolds number, Froude number, and gravitational settling parameter space. The initial matrix specified only tests at 100% U0D0 and 25% U0D0. After initial tests were conducted with small diameter, low viscosity simulant this matrix was revised to allow evaluation of a broader range of U0D0s. The revised matrix included full factorial test between 100% and 50% U0D0 and two half-factorial tests at 75% and 25% U0D0. Adding points at 75% U0D0 and 50% U0D0 allowed evaluation curvature. Eliminating points at 25% U0D0 decreased the testing time by several weeks. Test conditions were achieved by varying the simulant viscosity, the mean particle size, and the jet nozzle exit velocity. Concentration measurements at sampling locations throughout the tank were used to assess the degree of uniformity achieved during each test. Concentration data was obtained using a real time ultrasonic attenuation probe and discrete batch samples. The undissolved solids concentration at these locations was analyzed to determine whether the tank contents were uniform (< ±10% variation about mean) or nonuniform (> ±10% variation about mean) in concentration. Concentration inhomogeneity was modeled as a function of dimensionless groups. The two parameters that best describe the maximum solids volume fraction that can be suspended in a double-shell tank were found to be 1) the Froude number (Fr) based on nozzle velocity (U0) and tank contents level (H) and 2) the dimensionless particle size (dp/D0). The dependence on the Reynolds number (Re) does not appear to be statistically significant.« less

Calibration transfer of a Raman spectroscopic quantification method for the assessment of liquid detergent compositions between two at-line instruments installed at two liquid detergent production plants.

PubMed

Brouckaert, D; Uyttersprot, J-S; Broeckx, W; De Beer, T

2017-09-01

Calibration transfer of partial least squares (PLS) quantification models is established between two Raman spectrometers located at two liquid detergent production plants. As full recalibration of existing calibration models is time-consuming, labour-intensive and costly, it is investigated whether the use of mathematical correction methods requiring only a handful of standardization samples can overcome the dissimilarities in spectral response observed between both measurement systems. Univariate and multivariate standardization approaches are investigated, ranging from simple slope/bias correction (SBC), local centring (LC) and single wavelength standardization (SWS) to more complex direct standardization (DS) and piecewise direct standardization (PDS). The results of these five calibration transfer methods are compared reciprocally, as well as with regard to a full recalibration. Four PLS quantification models, each predicting the concentration of one of the four main ingredients in the studied liquid detergent composition, are aimed at transferring. Accuracy profiles are established from the original and transferred quantification models for validation purposes. A reliable representation of the calibration models performance before and after transfer is thus established, based on β-expectation tolerance intervals. For each transferred model, it is investigated whether every future measurement that will be performed in routine will be close enough to the unknown true value of the sample. From this validation, it is concluded that instrument standardization is successful for three out of four investigated calibration models using multivariate (DS and PDS) transfer approaches. The fourth transferred PLS model could not be validated over the investigated concentration range, due to a lack of precision of the slave instrument. Comparing these transfer results to a full recalibration on the slave instrument allows comparison of the predictive power of both Raman systems and leads to the formulation of guidelines for further standardization projects. It is concluded that it is essential to evaluate the performance of the slave instrument prior to transfer, even when it is theoretically identical to the master apparatus. Copyright © 2017 Elsevier B.V. All rights reserved.

Water quality in the Bear River Basin of Utah, Idaho, and Wyoming prior to and following snowmelt runoff in 2001

USGS Publications Warehouse

Gerner, Steven J.; Spangler, Lawrence E.

2006-01-01

Water-quality samples were collected from the Bear River during two base-flow periods in 2001: March 11 to 21, prior to snowmelt runoff, and July 30 to August 9, following snowmelt runoff. The samples were collected from 65 sites along the Bear River and selected tributaries and analyzed for dissolved solids and major ions, suspended sediment, nutrients, pesticides, and periphyton chlorophyll a.On the main stem of the Bear River during March, dissolved-solids concentrations ranged from 116 milligrams per liter (mg/L) near the Utah-Wyoming Stateline to 672 mg/L near Corinne, Utah. During July-August, dissolved-solid concentrations ranged from 117 mg/L near the Utah-Wyoming Stateline to 2,540 mg/L near Corinne and were heavily influenced by outflow from irrigation diversions. High concentrations of dissolved solids near Corinne result largely from inflow of mineralized spring water.Suspended-sediment concentrations in the Bear River in March ranged from 2 to 98 mg/L and generally decreased below reservoirs. Tributary concentrations were much higher, as high as 861 mg/L in water from Battle Creek. Streams with high sediment concentrations in March included Whiskey Creek, Otter Creek, and the Malad River. Sediment concentrations in tributaries in July-August generally were lower than in March.The concentrations of most dissolved and suspended forms of nitrogen generally were higher in March than in July-August. Dissolved ammonia concentrations in the Bear River and its tributaries in March ranged from less than 0.021 mg/L to as much as 1.43 mg/L, and dissolved ammonia plus organic nitrogen concentrations ranged from less than 0.1 mg/L to 2.4 mg/L. Spring Creek is the only site where the concentrations of all ammonia species exceeded 1.0 mg/L. In samples collected during March, tributary concentrations of dissolved nitrite plus nitrate ranged from 0.042 mg/L to 5.28 mg/L. In samples collected from tributaries during July-August, concentrations ranged from less than 0.23 mg/L to 3.06 mg/L. Concentrations of nitrite plus nitrate were highest in samples collected from the Whiskey Creek and Spring Creek drainage basins and from main-stem sites below Cutler Reservoir near Collinston (March) and Corinne (July-August).Concentrations of total phosphorus at main-stem sites were fairly similar during both base-flow periods, ranging from less than 0.02 to 0.49 mg/L during March and less than 0.02 to 0.287 mg/L during July-August. In March, concentrations of total phosphorus in the Bear River generally increased from upstream to downstream. Total phosphorus concentrations in tributaries generally were higher in March than in July-August.Concentrations of selected pesticides in samples collected from 20 sites in the Bear River basin in either March or July-August were less than 0.1 microgram per liter. Of the 12 pesticides detected, the most frequently detected insecticide was malathion, and prometon and atrazine were the most frequently detected herbicides.Periphyton samples were collected at 14 sites on the Bear River during August. Chlorophyll a concentrations ranged from 21 milligrams per square meter to 416 milligrams per square meter, with highest concentrations occurring below reservoirs. Samples from 8 of the 14 sites had concentrations of chlorophyll a that exceeded 100 milligrams per square meter, indicating that algal abundance at these sites may represent a nuisance condition.

Determination of hydroxylated polycyclic aromatic hydrocarbons by HPLC-photoionization tandem mass spectrometry in wood smoke particles and soil samples.

PubMed

Avagyan, Rozanna; Nyström, Robin; Boman, Christoffer; Westerholm, Roger

2015-06-01

A simple and fast method for analysis of hydroxylated polycyclic aromatic hydrocarbons using pressurized liquid extraction and high performance liquid chromatography utilizing photoionization tandem mass spectrometry was developed. Simultaneous separation and determination of nine hydroxylated polycyclic aromatic hydrocarbons and two hydroxy biphenyls could be performed in negative mode with a run time of 12 min, including equilibration in 5 min. The calibration curves were in two concentration ranges; 1-50 ng/mL and 0.01-50 μg/mL, with coefficients of correlation R (2) > 0.997. The limits of detection and method quantification limits were in the range of 9-56 pg and 5-38 ng/g, respectively. A two-level full factorial experimental design was used for screening of conditions with the highest impact on the extraction. The extraction procedure was automated and suitable for a large number of samples. The extraction recoveries ranged from 70 to 102 % and the matrix effects were between 92 and 104 %. The overall method was demonstrated on wood smoke particles and soil samples with good analytical performance, and five OH-PAHs were determined in the concentration range of 0.19-210 μg/g. As far as we know, hydroxylated polycyclic aromatic hydrocarbons were determined in wood smoke and soil samples using photoionization mass spectrometry for the first time in this present study. Accordingly, this study shows that high performance liquid chromatography photoionization tandem mass spectrometry can be a good option for the determination of hydroxylated polycyclic aromatic hydrocarbons in complex environmental samples. Graphical Abstract The method developed in this study was used to determine hydroxylated polycyclic aromatic hydrocarbons in wood smoke and soil.

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

USGS Publications Warehouse

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

1989-01-01

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

Estimation of spatial patterns of urban air pollution over a 4-week period from repeated 5-min measurements

NASA Astrophysics Data System (ADS)

Gillespie, Jonathan; Masey, Nicola; Heal, Mathew R.; Hamilton, Scott; Beverland, Iain J.

2017-02-01

Determination of intra-urban spatial variations in air pollutant concentrations for exposure assessment requires substantial time and monitoring equipment. The objective of this study was to establish if short-duration measurements of air pollutants can be used to estimate longer-term pollutant concentrations. We compared 5-min measurements of black carbon (BC) and particle number (PN) concentrations made once per week on 5 occasions, with 4 consecutive 1-week average nitrogen dioxide (NO2) concentrations at 18 locations at a range of distances from busy roads in Glasgow, UK. 5-min BC and PN measurements (averaged over the two 5-min periods at the start and end of a week) explained 40-80%, and 7-64% respectively, of spatial variation in the intervening 1-week NO2 concentrations for individual weeks. Adjustment for variations in background concentrations increased the percentage of explained variation in the bivariate relationship between the full set of NO2 and BC measurements over the 4-week period from 28% to 50% prior to averaging of repeat measurements. The averages of five 5-min BC and PN measurements made over 5 weeks explained 75% and 33% respectively of the variation in average 1-week NO2 concentrations over the same period. The relatively high explained variation observed between BC and NO2 measured on different time scales suggests that, with appropriate steps to correct or average out temporal variations, repeated short-term measurements can be used to provide useful information on longer-term spatial patterns for these traffic-related pollutants.

Effect of Preactivation on Torque Enhancement by the Stretch-Shortening Cycle in Knee Extensors

PubMed Central

Fukutani, Atsuki; Misaki, Jun; Isaka, Tadao

2016-01-01

The stretch-shortening cycle is one of the most interesting topics in the field of sport sciences, because the performance of human movement is enhanced by the stretch-shortening cycle (eccentric contraction). The purpose of the present study was to examine whether the influence of preactivation on the torque enhancement by stretch-shortening cycle in knee extensors. Twelve men participated in this study. The following three conditions were conducted for knee extensors: (1) concentric contraction without preactivation (CON), (2) concentric contraction with eccentric preactivation (ECC), and (3) concentric contraction with isometric preactivation (ISO). Muscle contractions were evoked by electrical stimulation to discard the influence of neural activity. The range of motion of the knee joint was set from 80 to 140 degrees (full extension = 180 degrees). Angular velocities of the concentric and eccentric contractions were set at 180 and 90 degrees/s, respectively. In the concentric contraction phase, joint torques were recorded at 85, 95, and 105 degrees, and they were compared among the three conditions. In the early phase (85 degrees) of concentric contraction, the joint torque was larger in the ECC and ISO conditions than in the CON condition. However, these clear differences disappeared in the later phase (105 degrees) of concentric contraction. The results showed that joint torque was clearly different among the three conditions in the early phase whereas this difference disappeared in the later phase. Thus, preactivation, which is prominent in the early phase of contractions, plays an important role in torque enhancement by the stretch-shortening cycle in knee extensors. PMID:27414804

A diurnal component to the variation in sieve tube amino acid content in wheat.

PubMed

Gattolin, Stefano; Newbury, H John; Bale, Jeffrey S; Tseng, Hua-Ming; Barrett, David A; Pritchard, Jeremy

2008-06-01

We have used high-sensitivity capillary electrophoresis coupled to a laser-induced fluorescence detection method to quantify 16 amino acids in wheat (Triticum aestivum) sieve tube (ST) samples as small as 2 nL collected by severing the stylets of feeding aphids. The sensitivity of the method was sufficient to determine a quantitative amino acid profile of individual STs without the need to bulk samples to produce larger volumes for analysis. This allowed the observation of the full range of variation that exists in individual STs. Some of the total concentrations of amino acids recorded are higher than those reported previously. The results obtained show variation in the concentrations of phenylalanine (Phe), histidine/valine (His/Val), leucine/isoleucine (Leu/Ile), arginine, asparagine, glutamine, tyrosine (Tyr), and lysine (Lys) across the ST samples. These could not be explained by plant-to-plant variation. Statistical analyses revealed five analytes (Tyr, Lys, Phe, His/Val, and Leu/Ile) that showed striking covariation in their concentrations across ST samples. A regression analysis revealed a significant relationship between the concentrations of Tyr, Lys, Phe, Leu/Ile, His/Val, asparagine, arginine, and proline and the time of collection of ST samples, with these amino acids increasing in concentration during the afternoon. This increase was confirmed to occur in individual STs by analyzing samples obtained from stylet bundles exuding for many hours. Finally, an apparent relationship between the exudation rate of ST sap and its total amino acid concentration was observed: samples containing higher total amino acid concentrations were observed to exude from the severed stylet bundles more slowly.

Chlorinated and polycyclic aromatic hydrocarbons in riverine and estuarine sediments from Pearl River Delta, China.

PubMed

Mai, Bi-Xian; Fu, Jia-Mo; Sheng, Guo-Ying; Kang, Yue-Hui; Lin, Zheng; Zhang, Gan; Min, Yu-Shuan; Zeng, Eddy Y

2002-01-01

Spatial distribution of chlorinated hydrocarbons [chlorinated pesticides (CPs) and polychlorinated biphenyls (PCBs)] and polycyclic aromatic hydrocarbons (PAHs) was measured in riverine and estuarine sediment samples from Pearl River Delta, China, collected in 1997. Concentrations of CPs of the riverine sediment samples range from 12 to 158 ng/g, dry weight, while those of PCBs range from 11 to 486 ng/g. The CPs concentrations of the estuarine sediment samples are in the range 6-1658 ng/g, while concentrations of PCBs are in the range 10-339 ng/g. Total PAH concentration ranges from 1168 to 21,329 ng/g in the riverine sediment samples, whereas the PAH concentration ranges from 323 to 14,812 ng/g in the sediment samples of the Estuary. Sediment samples of the Zhujiang River and Macao harbor around the Estuary show the highest concentrations of CPs, PCBs, and PAHs. Possible factors affecting the distribution patterns are also discussed based on the usage history of the chemicals, hydrologic condition, and land erosion due to urbanization processes. The composition of PAHs is investigated and used to assess petrogenic, combustion and naturally derived PAHs of the sediment samples of the Pearl River Delta. In addition, the concentrations of a number of organic compounds of the Pearl River Delta samples indicate that sediments of the Zhujiang river and Macao harbor are most likely to pose biological impairment.

A simple capacitive method to evaluate ethanol fuel samples

NASA Astrophysics Data System (ADS)

Vello, Tatiana P.; de Oliveira, Rafael F.; Silva, Gustavo O.; de Camargo, Davi H. S.; Bufon, Carlos C. B.

2017-02-01

Ethanol is a biofuel used worldwide. However, the presence of excessive water either during the distillation process or by fraudulent adulteration is a major concern in the use of ethanol fuel. High water levels may cause engine malfunction, in addition to being considered illegal. Here, we describe the development of a simple, fast and accurate platform based on nanostructured sensors to evaluate ethanol samples. The device fabrication is facile, based on standard microfabrication and thin-film deposition methods. The sensor operation relies on capacitance measurements employing a parallel plate capacitor containing a conformational aluminum oxide (Al2O3) thin layer (15 nm). The sensor operates over the full range water concentration, i.e., from approximately 0% to 100% vol. of water in ethanol, with water traces being detectable down to 0.5% vol. These characteristics make the proposed device unique with respect to other platforms. Finally, the good agreement between the sensor response and analyses performed by gas chromatography of ethanol biofuel endorses the accuracy of the proposed method. Due to the full operation range, the reported sensor has the technological potential for use as a point-of-care analytical tool at gas stations or in the chemical, pharmaceutical, and beverage industries, to mention a few.

Analysis of the convergence rules of full-range PSD surface error of magnetorheological figuring KDP crystal.

PubMed

Chen, Shaoshan; He, Deyu; Wu, Yi; Chen, Huangfei; Zhang, Zaijing; Chen, Yunlei

2016-10-01

A new non-aqueous and abrasive-free magnetorheological finishing (MRF) method is adopted for processing potassium dihydrogen phosphate (KDP) crystal due to its low hardness, high brittleness, temperature sensitivity, and water solubility. This paper researches the convergence rules of the surface error of an initial single-point diamond turning (SPDT)-finished KDP crystal after MRF polishing. Currently, the SPDT process contains spiral cutting and fly cutting. The main difference of these two processes lies in the morphology of intermediate-frequency turning marks on the surface, which affects the convergence rules. The turning marks after spiral cutting are a series of concentric circles, while the turning marks after fly cutting are a series of parallel big arcs. Polishing results indicate that MRF polishing can only improve the low-frequency errors (L>10  mm) of a spiral-cutting KDP crystal. MRF polishing can improve the full-range surface errors (L>0.01  mm) of a fly-cutting KDP crystal if the polishing process is not done more than two times for single surface. We can conclude a fly-cutting KDP crystal will meet better optical performance after MRF figuring than a spiral-cutting KDP crystal with similar initial surface performance.

Seasonal patterns in carbon dioxide in 15 mid-continent (USA) reservoirs

USGS Publications Warehouse

Jones, John R.; Obrecht, Daniel V.; Graham, Jennifer L.; Balmer, Michelle B.; Filstrup, Christopher T.; Downing, John A.

2016-01-01

Evidence suggests that lakes are important sites for atmospheric CO2 exchange and so play a substantial role in the global carbon budget. Previous research has 2 weaknesses: (1) most data have been collected only during the open-water or summer seasons, and (2) data are concentrated principally on natural lakes in northern latitudes. Here, we report on the full annual cycle of atmospheric CO2 exchanges of 15 oligotrophic to eutrophic reservoirs in the Glacial Till Plains of the United States. With one exception, these reservoirs showed an overall loss of CO2 during the year, with most values within the lower range reported for temperate lakes. There was a strong cross-system seasonal pattern: an average of 70% of total annual CO2 efflux occurred by the end of spring mixis; some 20% of annual flux was reabsorbed during summer stratification; and the remaining 50% of efflux was lost during autumnal mixing. Net annual flux was negatively correlated with depth and positively correlated with both water residence time and DOC, with the smallest annual CO2 efflux measured in shallow fertile impoundments. Strong correlations yield relationships allowing regional up-scaling of CO2 evasion. Understanding lacustrine CO2 uptake and evasion requires seasonal analyses across the full range of lake trophic states and morphometric attributes.

EPA Region 6 Laboratory Method Specific Analytical Capabilities with Sample Concentration Range

EPA Pesticide Factsheets

EPA Region 6 Environmental Services Branch (ESB) Laboratory is capable of analyzing a wide range of samples with concentrations ranging for low part-per trillion (ppt) to low percent () levels, depending on the sample matrix.

Airborne asbestos take-home exposures during handling of chrysotile-contaminated clothing following simulated full shift workplace exposures.

PubMed

Sahmel, Jennifer; Barlow, Christy A; Gaffney, Shannon; Avens, Heather J; Madl, Amy K; Henshaw, John; Unice, Ken; Galbraith, David; DeRose, Gretchen; Lee, Richard J; Van Orden, Drew; Sanchez, Matthew; Zock, Matthew; Paustenbach, Dennis J

2016-01-01

The potential for para-occupational, domestic, or take-home exposures from asbestos-contaminated work clothing has been acknowledged for decades, but historically has not been quantitatively well characterized. A simulation study was performed to measure airborne chrysotile concentrations associated with laundering of contaminated clothing worn during a full shift work day. Work clothing fitted onto mannequins was exposed for 6.5 h to an airborne concentration of 11.4 f/cc (PCME) of chrysotile asbestos, and was subsequently handled and shaken. Mean 5-min and 15-min concentrations during active clothes handling and shake-out were 3.2 f/cc and 2.9 f/cc, respectively (PCME). Mean airborne PCME concentrations decreased by 55% 15 min after clothes handling ceased, and by 85% after 30 min. PCM concentrations during clothes handling were 11-47% greater than PCME concentrations. Consistent with previously published data, daily mean 8-h TWA airborne concentrations for clothes-handling activity were approximately 1.0% of workplace concentrations. Similarly, weekly 40-h TWAs for clothes handling were approximately 0.20% of workplace concentrations. Estimated take-home cumulative exposure estimates for weekly clothes handling over 25-year working durations were below 1 f/cc-year for handling work clothes contaminated in an occupational environment with full shift airborne chrysotile concentrations of up to 9 f/cc (8-h TWA).

Water-quality conditions and streamflow gain and loss of the South Prong of Spavinaw Creek basin, Benton County, Arkansas

USGS Publications Warehouse

Joseph, Robert L.; Green, W. Reed

1994-01-01

A study of the South Prong of Spavinaw Creek Basin conducted baween July 14 and July 23. 1993. described the surface- and ground-water quality of the basin and the streamflow gain and loss. Water samples were collected from 10 sites on the mainstem of the South Prong of Spavinaw Creek and from 4 sites on tributaries during periods of low to moderate streamflow (less than 11 cubic feet per second). Water samples were collected from 4 wells and 10 springs located in the basin. In 14 surface-water samples, nitrite plus nitrate concentrations ranged from 0.75 to 4.2 milligrams per liter as nitrogen (mg/L). Orthophosphorus concentrations ranged from 0 03 to O. 15 mg/L as phosphorus. Fecal coliform bacteria counts ranged from 61 to 1,400 colonies per 100 milliliters (col/lOO mL), with a median of 120 col/100 mL. Fecal streptococci bacteria counts ranged from 70 to greater than 2,000 col/100 mL with a median of 185 col/lOO mL. Analysis for selected metals collected at one surface-water sites indicates that concentrations were usually below the reporting limit. Diel dissolved oxygen concentrations and temperatures were measured at an upstream and downstream site on the mainstem of the stream. At the upstream site, dissolved oxygen concentrations ranged from 7.2 to 83 mg/L and temperatures ranged from 15.5 to 17.0 C. Dissolved oxygen concentrations were higher and temperature values were lower at lhe upstream site, which is located close to two springs that produce all of the flow at that site. Dissolved nitrite plus nitrate was present in all four wells sampled in the basin with concentrations ranging from 0.04 to 3.5 mg/L as nitrogen. Orthophosphorus was present in concentrations ranging from less than 0.01 to 0.07 mg/L as phosphorus. Volatile organic compound analyses in two wells indicate that toluene was present in both wells and chloroform was present in one well. All other volatile organic compounds were found to be below the reporting limits. Analysis for common constituents and selected metals indicated that fluoride concentrations in one well exceeded the U.S. Environmental Protection Agency's primary maximum contamination levels for drinking water. Analyses of water samples collected from springs indicate that nitrite plus nitrate concen- trations ranged from 0.43 to 3.9 mg/L as nitrogen. Dissolved ammonia plus organic nitrogen concentrations ranged from less than 0.20 to 0.64 mg/L as nitrogen. Dissolved ammonia plus organic nitrogen concentrations ranged from less than 0.20 to 0.64 mg/L at nitrogen. Orthophosphorus concentrations ranged from 0.02 to 0.09 mg/L as phosphorus. Fecal coliform bacteria counts ranged from less than 3 to more than 2,000 col/100 mL, with a median of 370 col/100 mL. Fecal streptococci bacteria counts ranged from less than 4 to greater than 2,000 col/100 mL with a median of 435 col/100 mL. Streamflow in nine reaches of the mainstream increased an average of 20 percent. Six losing reaches were identified during the study, one located on the mainstem and the other five located on tributaries to the mainstem.

40 CFR Table C-1 to Subpart C of... - Test Concentration Ranges, Number of Measurements Required, and Maximum Discrepancy Specifications

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 6 2014-07-01 2014-07-01 false Test Concentration Ranges, Number of Measurements Required, and Maximum Discrepancy Specifications C Table C-1 to Subpart C of Part 53 Protection of... Reference Methods Pt. 53, Subpt. C, Table C-1 Table C-1 to Subpart C of Part 53—Test Concentration Ranges...

40 CFR Table C-1 to Subpart C of... - Test Concentration Ranges, Number of Measurements Required, and Maximum Discrepancy Specifications

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 6 2012-07-01 2012-07-01 false Test Concentration Ranges, Number of Measurements Required, and Maximum Discrepancy Specifications C Table C-1 to Subpart C of Part 53 Protection of... Reference Methods Pt. 53, Subpt. C, Table C-1 Table C-1 to Subpart C of Part 53—Test Concentration Ranges...

40 CFR Table C-1 to Subpart C of... - Test Concentration Ranges, Number of Measurements Required, and Maximum Discrepancy Specifications

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 6 2013-07-01 2013-07-01 false Test Concentration Ranges, Number of Measurements Required, and Maximum Discrepancy Specifications C Table C-1 to Subpart C of Part 53 Protection of... Reference Methods Pt. 53, Subpt. C, Table C-1 Table C-1 to Subpart C of Part 53—Test Concentration Ranges...

40 CFR Table C-1 to Subpart C of... - Test Concentration Ranges, Number of Measurements Required, and Maximum Discrepancy Specifications

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 5 2011-07-01 2011-07-01 false Test Concentration Ranges, Number of Measurements Required, and Maximum Discrepancy Specifications C Table C-1 to Subpart C of Part 53 Protection of... Reference Methods Pt. 53, Subpt. C, Table C-1 Table C-1 to Subpart C of Part 53—Test Concentration Ranges...

Validation of a novel high-sensitivity radioimmunoassay procedure for measurement of total thyroxine concentration in psittacine birds and snakes.

PubMed

Greenacre, C B; Young, D W; Behrend, E N; Wilson, G H

2001-11-01

To validate a novel high-sensitivity radioimmunoassay (RIA) procedure developed to accurately measure the relatively low serum total thyroxine (T4) concentrations of birds and reptiles and to establish initial reference ranges forT4 concentration in selected species of psittacine birds and snakes. 56 healthy nonmolting adult psittacine birds representing 6 species and 42 captive snakes representing 4 species. A solid-phase RIA designed to measure free T4 concentrations in dialysates of human serum samples was used without dialysis to evaluate total T4 concentration in treated samples obtained from birds and reptiles. Serum T4 binding components were removed to allow assay of undialyzed samples. Assay validation was assessed by determining recovery of expected amounts of T4 in treated samples that were serially diluted or to which T4 was added. Intra- and interassay coefficient of variation (CV) was determined. Mean recovery of T4 added at 4 concentrations ranged from 84.9 to 115.0% and 95.8 to 119.4% in snakes and birds, respectively. Intra- and interassay CV was 3.8 and 11.3%, respectively. Serum total T4 concentrations for 5 species of birds ranged from 2.02 to 768 nmol/L but ranged from 3.17 to 142 nmol/L for blue-fronted Amazon parrots; concentrations ranged from 0.21 to 6.06 nmol/L for the 4 species of snakes. This new RIA method provides a commercially available, accurate, and sensitive method for measurement of the relatively low serum T4 concentrations of birds and snakes. Initial ranges for the species evaluated were established.

Compounds Released from Biomass Deconstruction: Understanding Their Effect on Cellulose Enzyme Hydrolysis and Their Biological Activity

NASA Astrophysics Data System (ADS)

Djioleu, Angele Mezindjou

The effect of compounds produced during biomass pretreatment on cellulolytic enzyme was investigated. Liquid prehydrolyzates were prepared by pretreating switchgrass using 24 combinations of temperature, time, and sulfuric acid concentration based on a full factorial design. Temperature was varied from 140°C to 180°C; time ranged from 10 to 40 min; and the sulfuric acid concentrations were 0.5% or 1% (v/v). Identified products in the prehydrolyzates included xylose, glucose, hydroxymethylfurfural (HMF), furfural, acetic acid, formic acid, and phenolic compounds at concentration ranging from 0 to 21.4 g/L. Pretreatment conditions significantly affected the concentrations of compounds detected in prehydrolyzates. When assayed in the presence of switchgrass prehydrolyzates against model substrates, activities of cellulase, betaglucosidase, and exoglucanase, were significantly reduced by at least 16%, 31.8%, and 57.8%, respectively, as compared to the control. A strong positive correlation between inhibition of betaglucosidase and concentration of glucose, acetic acid, and furans in prehydrolyzate was established. Exoglucanase inhibition correlated with the presence of phenolic compounds and acetic acid. The prehydrolyzate, prepared at 160°C, 30 min, and 1% acid, was fractionated by centrifugal partition chromatography (CPC) into six fractions; the inhibition effect of these fractions on betaglucosidase and exoglucanase was determined. The initial hydrolysis rate of cellobiose by betaglucosidase was significantly reduced by the CPC sugar-rich fraction; however, exoglucanase was deactivated by the CPC phenolic-rich fraction. Finally, biological activities of water-extracted compounds from sweetgum bark and their effect on cellulase was investigated. It was determined that 12% of solid content of the bark extract could be accounted by phenolic compounds with gallic acid identified as the most concentrated phytochemical. Sweetgum bark extract inhibited Staphylococcus aureus growth and copper-induced peroxidation of human low-density lipoprotein, confirming antimicrobial and antioxidant activities of the extract. On the other hand, bark extract inhibited cellulase cocktail activity by reducing cellulose hydrolysis by 82.32% after 48 h of incubation. Overall, phenolic compounds generated from biomass fractionation are important players in cellulolytic enzyme inhibition; removal of biomass extractives prior to pretreatment could reduce inhibitory compounds in prehydrolyzate while generating phytochemicals with societal benefits.

In vitro percutaneous penetration and characterization of silver from silver-containing textiles

PubMed Central

Bianco, Carlotta; Kezic, Sanja; Crosera, Matteo; Svetličić, Vesna; Šegota, Suzana; Maina, Giovanni; Romano, Canzio; Larese, Francesca; Adami, Gianpiero

2015-01-01

The objective of this study was to determine the in vitro percutaneous penetration of silver and characterize the silver species released from textiles in different layers of full thickness human skin. For this purpose, two different wound dressings and a garment soaked in artificial sweat were placed in the donor compartments of Franz cells for 24 hours. The concentration of silver in the donor phase and in the skin was determined by an electrothermal atomic absorption spectrometer (ET-AAS) and by inductively coupled plasma mass spectrometer (ICP-MS). The characterization of silver species in the textiles and in the skin layers was made by scanning electron microscopy with integrated energy dispersive X-ray spectroscopy (SEM-EDX). Additionally, the size distribution of silver nanoparticles in the textiles was performed by atomic force microscopy (AFM). On the surface of all investigated materials, silver nanoparticles of different size and morphology were found. Released silver concentrations in the soaking solutions (ie, exposure concentration) ranged from 0.7 to 4.7 μg/mL (0.6–4.0 μg/cm2), fitting the bactericidal range. Silver and silver chloride aggregates at sizes of up to 1 μm were identified both in the epidermis and dermis. The large size of these particles suggests that the aggregation occurred in the skin. The formation of these aggregates likely slowed down the systemic absorption of silver. Conversely, these aggregates may form a reservoir enabling prolonged release of silver ions, which might lead to local effects. PMID:25792824

Postmortem Tissue Distribution of Acetyl Fentanyl, Fentanyl and their Respective Nor-Metabolites Analyzed by Ultrahigh Performance Liquid Chromatography with Tandem Mass Spectrometry

PubMed Central

Poklis, Justin; Poklis, Alphonse; Wolf, Carl; Mainland, Mary; Hair, Laura; Devers, Kelly; Chrostowski, Leszek; Arbefeville, Elise; Merves, Michele; Pearson, Julia

2015-01-01

In the last two years, an epidemic of fatal narcotic overdose cases has occurred in the Tampa area of Florida. Fourteen of these deaths involved fentanyl and/or the new designer drug, acetyl fentanyl. Victim demographics, case histories, toxicology findings and causes and manners of death, as well as, disposition of fentanyl derivatives and their nor-metabolites in postmortem heart blood, peripheral blood, bile, brain, liver, urine and vitreous humor are presented. In the cases involving only acetyl fentanyl (without fentanyl, n=4), the average peripheral blood acetyl fentanyl concentration was 0.467 mg/L (range 0.31 to .60 mg/L) and average acetyl norfentanyl concentration was 0.053 mg/L (range 0.002 to 0.086 mg/L). In the cases involving fentanyl (without acetyl fentanyl, n=7), the average peripheral blood fentanyl concentration was 0.012 mg/L (range 0.004 to 0.027 mg/L) and average norfentanyl blood concentration was 0.001 mg/L (range 0.0002 to 0.003 mg/L). In the cases involving both acetyl fentanyl and fentanyl (n=3), the average peripheral blood acetyl fentanyl concentration was 0.008 mg/L (range 0.006 to 0.012 mg/L), the average peripheral blood acetyl norfentanyl concentration was 0.001 mg/L (range 0.001 to 0.002 mg/L), the average peripheral blood fentanyl concentration was 0.018 mg/L (range 0.015 to 0.021 mg/L) and the average peripheral blood norfentanyl concentration was 0.002 mg/L (range 0.001 mg/L to 0.003 mg/L). Based on the toxicology results, it is evident that when fentanyl and/or acetyl fentanyl were present, they contributed to the cause of death. A novel ultrahigh performance liquid chromatography (UPLC) tandem mass spectrometry (MS/MS) method to identify and quantify acetyl fentanyl, acetyl norfentanyl, fentanyl and norfentanyl in postmortem fluids and tissues is also presented. PMID:26583960

Adaptive, full-spectrum solar energy system

DOEpatents

Muhs, Jeffrey D.; Earl, Dennis D.

2003-08-05

An adaptive full spectrum solar energy system having at least one hybrid solar concentrator, at least one hybrid luminaire, at least one hybrid photobioreactor, and a light distribution system operably connected to each hybrid solar concentrator, each hybrid luminaire, and each hybrid photobioreactor. A lighting control system operates each component.

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

USGS Publications Warehouse

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

2008-01-01

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

Trace metal characterization of aerosol particles and cloud water during HCCT 2010

NASA Astrophysics Data System (ADS)

Fomba, K. W.; van Pinxteren, D.; Müller, K.; Iinuma, Y.; Lee, T.; Collett, J. L., Jr.; Herrmann, H.

2015-08-01

Trace metal characterization of bulk and size-resolved aerosol and cloud water samples were performed during the Hill Cap Cloud Thuringia (HCCT) campaign. Cloud water was collected at the top of Mt. Schmücke while aerosol samples were collected at two stations upwind and downwind of Mt. Schmücke. Fourteen trace metals including Ti, V, Fe, Mn, Co, Zn, Ni, Cu, As, Sr, Rb, Pb, Cr, and Se were investigated during four full cloud events (FCEs) that fulfilled the conditions of a continuous air mass flow through the three stations. Aerosol particle trace metal concentrations were found to be lower than those observed in the same region during previous field experiments but were within a similar range to those observed in other rural regions in Europe. Fe and Zn were the most abundant elements with concentration ranges of 0.2-111.6 and 1.1-32.1 ng m-3, respectively. Fe, Mn, and Ti were mainly found in coarse mode aerosols while Zn, Pb, and As were mostly found in the fine mode. Correlation and enrichment factor analysis of trace metals revealed that trace metals such as Ti and Rb were mostly of crustal origin while trace metals such as Zn, Pb, As, Cr, Ni, V, and Cu were of anthropogenic origin. Trace metals such as Fe and Mn were of mixed origins including crustal and combustion sources. Trace metal cloud water concentration decreased from Ti, Mn, Cr, to Co with average concentrations of 9.18, 5.59, 5.54, and 0.46 μg L-1, respectively. A non-uniform distribution of soluble Fe, Cu, and Mn was observed across the cloud drop sizes. Soluble Fe and Cu were found mainly in cloud droplets with diameters between 16 and 22 μm, while Mn was found mostly in larger drops greater than 22 μm. Fe(III) was the main form of soluble Fe especially in the small and larger drops with concentrations ranging from 2.2 to 37.1 μg L-1. In contrast to other studies, Fe(II) was observed mainly in the evening hours, implying its presence was not directly related to photochemical processes. Aerosol-cloud interaction did not lead to a marked increase in soluble trace metal concentrations; rather it led to differences in the chemical composition of the aerosol due to preferential loss of aerosol particles through physical processes including cloud drop deposition to vegetative surfaces.

Trace metal characterization of aerosol particles and cloud water during HCCT 2010

NASA Astrophysics Data System (ADS)

Fomba, K. W.; van Pinxteren, D.; Müller, K.; Iinuma, Y.; Lee, T.; Collet, J., Jr.; Herrmann, H.

2015-04-01

Trace metal characterization of bulk and size resolved aerosol and cloud water samples were performed during the Hill Cap Cloud Thuringia (HCCT) campaign. Cloud water was collected at the top of Mt. Schmücke while aerosol samples were collected at two stations upwind and downwind of Mt. Schmücke. Fourteen trace metals including Ti, V, Fe, Mn, Co, Zn, Ni, Cu, As, Sr, Rb, Pb, Cr, and Se were investigated during four full cloud events (FCE) that fulfilled the conditions of a continuous air mass flow through the three stations. Aerosol particle trace metal concentrations were found to be lower than those observed in the same region during previous field experiments but were within a similar range to those observed in other rural regions in Europe. Fe and Zn were the most abundant elements with concentration ranges of 0.2-111.6 and 1.1-32.1 ng m-3, respectively. Fe, Mn and Ti were mainly found in coarse mode aerosols while Zn, Pb and As were mostly found in the fine mode. Correlation and enrichment factor analysis of trace metals revealed that trace metals such as Ti and Rb were mostly of crustal origin while trace metals such as Zn, Pb, As, Cr, Ni, V, and Cu were of anthropogenic origin. Trace metals such as Fe, Mn, were of mixed origins including crustal and combustion sources. Trace metal cloud water concentration decreased from Ti, Mn, Cr, to Co with average concentrations of 9.18, 5.59, 5.54, and 0.46 μg L-1, respectively. A non-uniform distribution of soluble Fe, Cu and Mn was observed across the cloud drop sizes. Soluble Fe and Cu were found mainly in cloud droplets with diameters between 16 and 22 μm while Mn was found mostly in larger drops greater than 22 μm. Fe (III) was the main form of soluble Fe especially in the small and larger drops with concentrations ranging from 2.2 to 37.1 μg L-1. In contrast to other studies, Fe (II) was observed mainly in the evening hours, implying its presence was not directly related to photochemical processes. Aerosol cloud interaction did not lead to a mark increase in soluble trace metal concentrations, but led to differences in the chemical composition of the aerosol due to preferential loss of aerosol particles through physical processes including cloud drop deposition to vegetative surfaces.

The refractive index of human hemoglobin in the visible range.

PubMed

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

2011-07-07

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

Experimental Study on Comprehensive Performance of Full Tailings Paste Filling in Jiaojia Gold Mine.

NASA Astrophysics Data System (ADS)

Zhang, Z. H.; Zou, Q. B.; Wang, P. Z.

2017-11-01

Filling mining method is the main method of modern underground mining. High concentration cementation is carried out using coarse tailing of +37 μm, and the mine has maturely used classified tailings paste filling technology. The gold mine studied on the performance of full tailings paste filling in order to maximize the use of tailings, reduce -37 μm fine tailings discharged into the tailing pond, reduce mining cost and eliminate security risks. The results show that: comprehensive index of full tailings paste filling is higher than that of classified tailings high concentration cementation filling, and the full tailings paste filling of 76% mass concentration has the best comprehensive index of slump, expansibility, yield stress and viscosity to meet the mining method requirements, which can effectively reduce the mining loss rate and dilution rate.

Concentrations of fecal coliform bacteria in creeks, Anchorage, Alaska, August and September 1998

USGS Publications Warehouse

Dorava, Joseph M.; Love, Andra

1999-01-01

Water samples were collected from five creeks in undeveloped, semi-developed, and developed areas of Anchorage, Alaska, during August and September 1998 to determine concentrations of fecal coliform bacteria. In undeveloped areas of Ship, Chester, and Campbell Creeks, and the semi-developed area of Rabbit Creek, concentrations of fecal coliform bacteria ranged from less than 1 to 16 colonies per 100 milliliters of water. In the semi-developed area of Little Rabbit Creek, concentrations ranged from 30 to 860 colonies per 100 milliliters of water. In developed areas of the creeks, concentrations of fecal coliform bacteria ranged from 6 to 80 colonies per 100 milliliters of water.

Indirect spectrophotometric determination of traces of bromide in water

USGS Publications Warehouse

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

1963-01-01

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

Prediction of Antibacterial Activity from Physicochemical Properties of Antimicrobial Peptides

PubMed Central

Melo, Manuel N.; Ferre, Rafael; Feliu, Lídia; Bardají, Eduard; Planas, Marta; Castanho, Miguel A. R. B.

2011-01-01

Consensus is gathering that antimicrobial peptides that exert their antibacterial action at the membrane level must reach a local concentration threshold to become active. Studies of peptide interaction with model membranes do identify such disruptive thresholds but demonstrations of the possible correlation of these with the in vivo onset of activity have only recently been proposed. In addition, such thresholds observed in model membranes occur at local peptide concentrations close to full membrane coverage. In this work we fully develop an interaction model of antimicrobial peptides with biological membranes; by exploring the consequences of the underlying partition formalism we arrive at a relationship that provides antibacterial activity prediction from two biophysical parameters: the affinity of the peptide to the membrane and the critical bound peptide to lipid ratio. A straightforward and robust method to implement this relationship, with potential application to high-throughput screening approaches, is presented and tested. In addition, disruptive thresholds in model membranes and the onset of antibacterial peptide activity are shown to occur over the same range of locally bound peptide concentrations (10 to 100 mM), which conciliates the two types of observations. PMID:22194847

Simulation of past exposure in slag wool production.

PubMed

Fallentin, B; Kamstrup, O

1993-08-01

A survey of the working conditions at a Danish slag wool production factory during the early technological phase in the 1940s is presented. No exposure data, however, are available for that period. So, a full-scale simulation of the past production of slag wool has been performed. Air monitoring was carried out in the working area around the cupola furnace. The aim was to measure exposure to air pollutants other than fibres. Such exposure might have confounded a possible association between lung cancer and exposure to fibres, in the early technological phase of slag wool production. The simulation experiment demonstrated exposure to PAH, a known lung carcinogen. The effect of other concurrent exposures is difficult to assess. Time-weighted average concentrations of particulate material ranged between 12.9 and 49.1 mg m-3 at the upper decks around the cupola. Corresponding concentrations of the dominant metals zinc and lead were 4.4-22.7 mg Zn m-3 and 0.9-4.7 mg Pb m-3. Significant concentrations of PAH up to 269 micrograms PAH m-3 (4 micrograms BaP m-3) occurred during ignition of the cupola furnace. The carbon monoxide level reached 270 ppm also during ignition.

Chip-to-chip SnO2 nanowire network sensors for room temperature H2 detection

NASA Astrophysics Data System (ADS)

Köck, A.; Brunet, E.; Mutinati, G. C.; Maier, T.; Steinhauer, S.

2012-06-01

The employment of nanowires is a very powerful strategy to improve gas sensor performance. We demonstrate a gas sensor device, which is based on silicon chip-to-chip synthesis of ultralong tin oxide (SnO2) nanowires. The sensor device employs an interconnected SnO2 nanowire network configuration, which exhibits a huge surface-to-volume ratio and provides full access of the target gas to the nanowires. The chip-to-chip SnO2 nanowire device is able to detect a H2 concentration of only 20 ppm in synthetic air with ~ 60% relative humidity at room temperature. At an operating temperature of 300°C a concentration of 50 ppm H2 results in a sensitivity of 5%. At this elevated temperature the sensor shows a linear response in a concentration range between 10 ppm and 100 ppm H2. The SnO2-nanowire fabrication procedure based on spray pyrolysis and subsequent annealing is performed at atmospheric pressure, requires no vacuum and allows upscale of the substrate to a wafer size. 3D-integration with CMOS chips is proposed as viable way for practical realization of smart nanowire based gas sensor devices for the consumer market.

Influence of sludge properties and hydraulic loading on the performance of secondary settling tanks--full-scale operational results.

PubMed

Vestner, R J; Günthert, F Wolfgang

2004-01-01

Full-scale investigations at a WWTP with a two-stage secondary settling tank process revealed relationships between significant operating parameters and performance in terms of effluent suspended solids concentration. Besides common parameters (e.g. surface overflow rate and sludge volume loading rate) feed SS concentration and flocculation time must be considered. Concentration of the return activated sludge may help to estimate the performance of existing secondary settling tanks.

The impact of production type and region on polychlorinated biphenyl (PCB), polychlorinated dibenzo-p-dioxin and dibenzofuran (PCDD/F) concentrations in Canadian chicken egg yolks.

PubMed

Rawn, Dorothea F K; Sadler, Amy R; Quade, Sue C; Sun, Wing-Fung; Kosarac, Ivana; Hayward, Stephen; Ryan, J Jake

2012-11-01

Chicken eggs from five different production types (conventional, omega-3 enriched, free range, organic and free run) were collected, when available, from three regions (west, central and east) of Canada to determine persistent organic pollutant (POP) concentrations. Total polychlorinated biphenyl (PCB) concentrations (∑37 congeners) in yolks from the eggs ranged from 0.162 ng g(-1) lipid to 24.8 ng g(-1) lipid (median 1.25 ng g(-1) lipid) while the concentration of the sum of the 6 indicator PCBs ranged from 0.100 ng g(-1) lipid to 9.33 ng g(-1) lipid (median 0.495 ng g(-1) lipid). Total polychlorinated dibenzo-p-dioxin/dibenzofuran (PCDD/F) concentrations ranged from 2.37 pg g(-1) lipid to 382 pg g(-1) lipid (median 9.53 pg g(-1) lipid). The 2005 WHO toxic equivalency (TEQ) ranged from 0.089 pg TEQ(PCDD/F+dioxin-like[DL]-PCB) g(-1) lipid to 12.8 pg TEQ(PCDD/F+DL-PCB) g(-1) lipid (median 0.342 pg TEQ(PCDD/F+DL-PCB) g(-1) lipid). PCB and PCDD/F concentrations were significantly different (p<0.001) in egg yolks from different regions of collection. In contrast to observations in Europe, PCB and PCDD/F concentrations in Canadian egg yolks were not impacted solely by the production type (e.g., conventional, free range, organic, etc.) used to maintain the laying chickens. Additionally, only one Canadian free range yolk from western Canada (12.8 pg TEQ(PCDD/F+DL-PCB) g(-1) lipid) exceeded the European toxic equivalent concentration limits for eggs (5 pg TEQ(PCDD/F+DL-PCB) g(-1) lipid). This differs from observations in Europe where free range/home produced eggs frequently have higher POP concentrations than eggs from other production types. Median PCB dietary intake estimates based on consumption of eggs were less than 10 ng d(-1) while median PCDD/F intakes were less than 45 pg d(-1). Crown Copyright © 2012. Published by Elsevier Ltd. All rights reserved.

Oak bark allometry and fire survival strategies in the Chihuahuan desert Sky Islands, Texas, USA.

PubMed

Schwilk, Dylan W; Gaetani, Maria S; Poulos, Helen M

2013-01-01

Trees may survive fire through persistence of above or below ground structures. Investment in bark aids in above-ground survival while investment in carbohydrate storage aids in recovery through resprouting and is especially important following above-ground tissue loss. We investigated bark allocation and carbohydrate investment in eight common oak (Quercus) species of Sky Island mountain ranges in west Texas. We hypothesized that relative investment in bark and carbohydrates changes with tree age and with fire regime: We predicted delayed investment in bark (positive allometry) and early investment in carbohydrates (negative allometry) under lower frequency, high severity fire regimes found in wetter microclimates. Common oaks of the Texas Trans-Pecos region (Quercus emoryi, Q. gambelii, Q. gravesii, Q. grisea, Q. hypoleucoides, Q. muehlenbergii, and Q. pungens) were sampled in three mountain ranges with historically mixed fire regimes: the Chisos Mountains, the Davis Mountains and the Guadalupe Mountains. Bark thickness was measured on individuals representing the full span of sizes found. Carbohydrate concentration in taproots was measured after initial leaf flush. Bark thickness was compared to bole diameter and allometries were analyzed using major axis regression on log-transformed measurements. We found that bark allocation strategies varied among species that can co-occur but have different habitat preferences. Investment patterns in bark were related to soil moisture preference and drought tolerance and, by proxy, to expected fire regime. Dry site species had shallower allometries with allometric coefficients ranging from less than one (negative allometry) to near one (isometric investment). Wet site species, on the other hand, had larger allometric coefficients, indicating delayed investment to defense. Contrary to our expectation, root carbohydrate concentrations were similar across all species and sizes, suggesting that any differences in below ground storage are likely to be in total volume of storage tissue rather than in carbohydrate concentration.

Oak Bark Allometry and Fire Survival Strategies in the Chihuahuan Desert Sky Islands, Texas, USA

PubMed Central

Schwilk, Dylan W.; Gaetani, Maria S.; Poulos, Helen M.

2013-01-01

Trees may survive fire through persistence of above or below ground structures. Investment in bark aids in above-ground survival while investment in carbohydrate storage aids in recovery through resprouting and is especially important following above-ground tissue loss. We investigated bark allocation and carbohydrate investment in eight common oak (Quercus) species of Sky Island mountain ranges in west Texas. We hypothesized that relative investment in bark and carbohydrates changes with tree age and with fire regime: We predicted delayed investment in bark (positive allometry) and early investment in carbohydrates (negative allometry) under lower frequency, high severity fire regimes found in wetter microclimates. Common oaks of the Texas Trans-Pecos region (Quercus emoryi, Q. gambelii, Q. gravesii, Q. grisea, Q. hypoleucoides, Q. muehlenbergii, and Q. pungens) were sampled in three mountain ranges with historically mixed fire regimes: the Chisos Mountains, the Davis Mountains and the Guadalupe Mountains. Bark thickness was measured on individuals representing the full span of sizes found. Carbohydrate concentration in taproots was measured after initial leaf flush. Bark thickness was compared to bole diameter and allometries were analyzed using major axis regression on log-transformed measurements. We found that bark allocation strategies varied among species that can co-occur but have different habitat preferences. Investment patterns in bark were related to soil moisture preference and drought tolerance and, by proxy, to expected fire regime. Dry site species had shallower allometries with allometric coefficients ranging from less than one (negative allometry) to near one (isometric investment). Wet site species, on the other hand, had larger allometric coefficients, indicating delayed investment to defense. Contrary to our expectation, root carbohydrate concentrations were similar across all species and sizes, suggesting that any differences in below ground storage are likely to be in total volume of storage tissue rather than in carbohydrate concentration. PMID:24244469

Fat-soluble vitamin and mineral comparisons between zoo-based and free-ranging koalas (Phascolarctos cinereus).

PubMed

Schmidt, Debra A; Pye, Geoffrey W; Hamlin-Andrus, Chris C; Ellis, William A; Bercovitch, Fred B; Ellersieck, Mark R; Chen, Tai C; Holick, Michael F

2013-12-01

As part of a health investigation on koalas at San Diego Zoo, serum samples were analyzed from 18 free-ranging and 22 zoo-based koalas, Phascolarctos cinereus. Serum concentrations of calcium, chloride, cobalt, copper, iron, magnesium, manganese, molybdenum, phosphorus, potassium, selenium, sodium, zinc, and vitamins A, E, and 25(OH)D3 were quantified. Calcium, chloride, molybdenum, selenium, and vitamin E concentrations were significantly higher in zoo-based koalas than in free-ranging koalas, whereas magnesium, manganese, phosphorus, and zinc concentrations were significantly higher in the free-ranging koalas. No significant differences were found between genders. The results from this study will help to establish a starting point for determining target circulating nutrient concentrations in koalas.

Influence of anodization parameters on the volume expansion of anodic aluminum oxide formed in mixed solution of phosphoric and oxalic acids

NASA Astrophysics Data System (ADS)

Kao, Tzung-Ta; Chang, Yao-Chung

2014-01-01

The growth of anodic alumina oxide was conducted in the mixed solution of phosphoric and oxalic acids. The influence of anodizing voltage, electrolyte temperature, and concentration of phosphoric and oxalic acids on the volume expansion of anodic aluminum oxide has been investigated. Either anodizing parameter is chosen to its full extent of range that allows the anodization process to be conducted without electric breakdown and to explore the highest possible volume expansion factor. The volume expansion factors were found to vary between 1.25 and 1.9 depending on the anodizing parameters. The variation is explained in connection with electric field, ion transport number, temperature effect, concentration, and activity of acids. The formation of anodic porous alumina at anodizing voltage 160 V in 1.1 M phosphoric acid mixed with 0.14 M oxalic acid at 2 °C showed the peak volume expansion factor of 1.9 and the corresponding moderate growth rate of 168 nm/min.

Enhanced power generation in concentrated photovoltaics using broadband antireflective coverglasses with moth eye structures.

PubMed

Song, Young Min; Jeong, Yonkil; Yeo, Chan Il; Lee, Yong Tak

2012-11-05

We present the effect of broadband antireflective coverglasses (BARCs) with moth eye structures on the power generation capability of a sub-receiver module for concentrated photovoltaics. The period and height of the moth eye structures were designed by a rigorous coupled-wave analysis method in order to cover the full solar spectral ranges without transmission band shrinkage. The BARCs with moth eye structures were prepared by the dry etching of silver (Ag) nanomasks, and the fabricated moth eye structures on coverglass showed strongly enhanced transmittance compared to the bare glass with a flat surface, at wavelengths of 300 - 1800 nm. The BARCs were mounted on InGaP/GaAs/Ge triple-junction solar cells and the power conversion efficiency of this sub-receiver module reached 42.16% for 196 suns, which is a 7.41% boosted value compared to that of a module with bare coverglass, without any detrimental changes of the open circuit voltages (V_oc) and fill factor (FF).

Enhanced power generation in concentrated photovoltaics using broadband antireflective coverglasses with moth eye structures.

PubMed

Song, Young Min; Jeong, Yonkil; Yeo, Chan Il; Lee, Yong Tak

2012-11-05

We present the effect of broadband antireflective coverglasses (BARCs) with moth eye structures on the power generation capability of a sub-receiver module for concentrated photovoltaics. The period and height of the moth eye structures were designed by a rigorous coupled-wave analysis method in order to cover the full solar spectral ranges without transmission band shrinkage. The BARCs with moth eye structures were prepared by the dry etching of silver (Ag) nanomasks, and the fabricated moth eye structures on coverglass showed strongly enhanced transmittance compared to the bare glass with a flat surface, at wavelengths of 300 - 1800 nm. The BARCs were mounted on InGaP/GaAs/Ge triple-junction solar cells and the power conversion efficiency of this sub-receiver module reached 42.16% for 196 suns, which is a 7.41% boosted value compared to that of a module with bare coverglass, without any detrimental changes of the open circuit voltages (V(oc)) and fill factor (FF).

Full-Field Measurements of Self-Excited Oscillations in Momentum-Dominated Helium Jets

NASA Technical Reports Server (NTRS)

Yildirim, B. S.; Agrawal, A. K.

2005-01-01

Flow structure of momentum-dominated helium jets discharged vertically into ambient air was investigated using a high-speed rainbow schlieren deflectometry (RSD) apparatus operated at up to 2000 Hz. The operating parameters, i.e., Reynolds number and Richardson number were varied independently to examine the self-excited, flow oscillatory behavior over a range of experimental conditions. Measurements revealed highly periodic oscillations in the laminar region at a unique frequency as well as high regularity in the flow transition and initial turbulent regions. The buoyancy was shown to affect the oscillation frequency and the distance from the jet exit to the flow transition plane. Instantaneous helium concentration contours across the field of view revealed changes in the jet flow structure and the evolution of the vortical structures during an oscillation cycle. A cross-correlation technique was applied to track the vortices and to find their convection velocity. Time-traces of helium concentration at different axial locations provided detailed information about the oscillating flow.

ICRF fast wave current drive and mode conversion current drive in EAST tokamak

NASA Astrophysics Data System (ADS)

Yin, L.; Yang, C.; Gong, X. Y.; Lu, X. Q.; Du, D.; Chen, Y.

2017-10-01

Fast wave in the ion-cyclotron resonance frequency (ICRF) range is a promising candidate for non-inductive current drive (CD), which is essential for long pulse and high performance operation of tokamaks. A numerical study on the ICRF fast wave current drive (FWCD) and mode-conversion current drive (MCCD) in the Experimental Advanced Superconducting Tokamak (EAST) is carried out by means of the coupled full wave and Ehst-Karney parameterization methods. The results show that FWCD efficiency is notable in two frequency regimes, i.e., f ≥ 85 MHz and f = 50-65 MHz, where ion cyclotron absorption is effectively avoided, and the maximum on-axis driven current per unit power can reach 120 kA/MW. The sensitivity of the CD efficiency to the minority ion concentration is confirmed, owing to fast wave mode conversion, and the peak MCCD efficiency is reached for 22% minority-ion concentration. The effects of the wave-launch position and the toroidal wavenumber on the efficiency of current drive are also investigated.

Evaluation of the thyroid status of Basenji dogs in Australia.

PubMed

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

2008-11-01

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

Water and sediment quality of the Lake Andes and Choteau Creek basins, South Dakota, 1983-2000

USGS Publications Warehouse

Sando, Steven Kent; Neitzert, Kathleen M.

2003-01-01

The Bureau of Reclamation has proposed construction of the Lake Andes/Wagner Irrigation Demonstration Project to investigate environmental effects of irrigation of glacial till soils substantially derived from marine shales. During 1983-2000, the U.S. Geological Survey collected hydrologic, water-quality, and sediment data in the Lake Andes and Choteau Creek Basins, and on the Missouri River upstream and downstream from Choteau Creek, to provide baseline information in support of the proposed demonstration project. Lake Andes has a drainage area of about 230 mi2 (square miles). Tributaries to Lake Andes are ephemeral. Water-level fluctuations in Lake Andes can be large, and the lake has been completely dry on several occasions. The outlet aqueduct from Lake Andes feeds into Garden Creek, which enters Lake Francis Case just upstream from Fort Randall Dam on the Missouri River. For Lake Andes tributary stations, calcium, magnesium, and sodium are approximately codominant among the cations, and sulfate is the dominant anion. Dissolved-solids concentrations typically range from about 1,000 mg/L (milligrams per liter) to about 1,700 mg/L. Major-ion concentrations for Lake Andes tend to be higher than the tributaries and generally increase downstream in Lake Andes. Proportions of major ions are similar among the different lake units (with the exception of Owens Bay), with calcium, magnesium, and sodium being approximately codominant among cations, and sulfate being the dominant anion. Owens Bay is characterized by a calcium sulfate water type. Dissolved-solids concentrations for Lake Andes typically range from about 1,400 to 2,000 mg/L. Whole-water nitrogen and phosphorus concentrations are similar among the Lake Andes tributaries, with median whole-water nitrogen concentrations ranging from about 1.6 to 2.4 mg/L, and median whole-water phosphorus concentrations ranging from about 0.5 to 0.7 mg/L. Whole-water nitrogen concentrations in Lake Andes are similar among the different units, with medians that range from about 2.4 to 4.0 mg/L. Median whole-water phosphorus concentrations for the different Lake Andes units range from 0.2 to 0.5 mg/L, and decrease downstream through Lake Andes. Median selenium concentrations are substantially lower for Andes Creek (3 ?g/L (micrograms per liter)) than for the other tributary stations (34, 18, and 7 ?g/L). Median selenium concentrations for the lake stations (ranging from less than 1 to 2 ?g/L) are substantially lower than tributary stations. The pesticides 2,4-D and atrazine were the most commonly detected pesticides in Lake Andes. Median concentrations for 2,4-D for Lake Andes range from 0.07 to 0.11 ?g/L; the median concentration for Owens Bay is 0.04 ?g/L. Median concentrations for atrazine for Lake Andes range from 0.2 to 0.4 ?g/L; the median concentration for Owens Bay is less than 0.1 ?g/L. Concentrations of both 2,4-D and atrazine are largest for the most upstream part of Lake Andes that is most influenced by tributary inflow. Median suspended-sediment concentrations for Lake Andes tributaries range from 22 to 56 mg/L. Most of the suspended sediment transported in the Lake Andes tributaries consists of particles less than 63 ?m (micrometers) in diameter. Concentrations of most constituents in bottom sediments generally had similar ranges and medians for the Lake Andes tributaries. However, Andes Creek generally had lower concentrations of several metals. For Lake Andes, medians and ranges for most constituents generally were similar among the different units. However, selenium concentrations tended to be higher in the upstream part of the lake, and generally decreased downstream. Results of vertical sediment cores collected from a single site in the South Unit of Lake Andes in October 2000 indicate that selenium loading to Lake Andes increased during the period 1952 through 2000. Choteau Creek has a drainage area of 619 mi2. In the upstream part of the basin, Chotea

Effluent concentration and removal efficiency of nine heavy metals in secondary treatment plants in Shanghai, China.

PubMed

Feng, Jingjing; Chen, Xiaolin; Jia, Lei; Liu, Qizhen; Chen, Xiaojia; Han, Deming; Cheng, Jinping

2018-04-10

Wastewater treatment plants (WWTPs) are the most common form of industrial and municipal wastewater control. To evaluate the performance of wastewater treatment and the potential risk of treated wastewater to aquatic life and human health, the influent and effluent concentrations of nine toxic metals were determined in 12 full-scale WWTPs in Shanghai, China. The performance was evaluated based on national standards for reclamation and aquatic criteria published by US EPA, and by comparison with other full-scale WWTPs in different countries. Potential sources of heavy metals were recognized using partial correlation analysis, hierarchical clustering, and principal component analysis (PCA). Results indicated significant treatment effect on As, Cd, Cr, Cu, Hg, Mn, Pb, and Zn. The removal efficiencies ranged from 92% (Cr) to 16.7% (Hg). The results indicated potential acute and/or chronic effect of Cu, Ni, Pb, and Zn on aquatic life and potential harmful effect of As and Mn on human health for the consumption of water and/or organism. The results of partial correlation analysis, hierarchical clustering based on cosine distance, and PCA, which were consistent with each other, suggested common source of Cd, Cr, Cu, and Pb and common source of As, Hg, Mn, Ni, and Zn. Hierarchical clustering based on Jaccard similarity suggested common source of Cd, Hg, and Ni, which was statistically proved by Fisher's exact test.

Evaluation of Emerging Contaminants of Concern at the South District Wastewater Treatment Plant Based on Seasonal Events, Miami-Dade County, Florida, 2004

USGS Publications Warehouse

Lietz, Arthur C.; Meyer, Michael T.

2006-01-01

The Comprehensive Everglades Restoration Plan has identified highly treated wastewater as a possible water source for the restoration of natural water flows and hydroperiods in selected coastal areas, including the Biscayne Bay coastal wetlands. One potential source of reclaimed wastewater for the Biscayne Bay coastal wetlands is the effluent from the South District Wastewater Treatment Plant in southern Miami-Dade County. The U.S. Geological Survey, in cooperation with the Comprehensive Everglades Restoration Plan Wastewater Reuse Technology Pilot Project Delivery Team, initiated a study to assess the presence of emerging contaminants of concern in the South District Wastewater Treatment Plant influent and effluent using current wastewater-treatment methods. As part of the study, 24-hour composite and discrete samples were collected at six locations (influent at plants 1 and 2, effluent pump, reuse train, chlorine dioxide unit, and ultraviolet pilot unit) at the plant during: (1) a dry-season, low-flow event on March 2-3, 2004, with an average inflow rate of 83.7 million gallons per day; (2) a wet-season, average-flow event on July 20-21, 2004, with an average inflow rate of 89.7 million gallons per day; and (3) high-rate disinfection tests on October 5 and 20, 2004, with average flow rates of 84.1 and 119.6 million gallons per day, respectively. During these four sampling events, 26, 27, 29, and 35 constituents were detected, respectively. The following transformations in concentration were determined in the waste stream: -100 to 180 percent at the effluent pump and -100 to 85 percent at the reuse train on March 2-3, 2004, and -100 to 1,609 percent at the effluent pump and -100 to 832 percent at the reuse train on July 20-21, 2004; -100 to -37 percent at the effluent pump, -100 to -62 percent at the reuse train, -100 to -56 percent at the chlorine dioxide unit, and -100 to -40 percent at the ultraviolet pilot unit on October 5, 2004; and -100 to -4 percent at the effluent pump, -100 to 17 percent at the reuse train, -100 to -40 percent at the chlorine dioxide unit, and -100 to -14 percent at the ultraviolet pilot unit on October 20, 2004. Samples were tested for detection of household and industrial (organic) wastewater compounds, pharmaceutical compounds, antibiotic compounds, and hormones in influent. Two 'known' endocrine disrupting compounds?17 beta-estradiol (E2) and diethoxynonylphenol? and four 'suspected' endocrine-disrupting compounds?1,4-dichlorobenzene, benzophenone, tris(2-chloroethyl) phosphate, and tris(dichloroisopropyl) phosphate?were detected during these sampling events. Phenanthrene and indole showed the greatest concentration ranges and highest concentrations for the organic wastewater compounds. Acetaminophen showed the greatest concentration range and highest concentration, and warfarin showed the smallest concentration range for the pharmaceutical compounds. Sulfamethoxazole (a sulfonamide) showed the greatest concentration range and highest concentration, and sulfathiozole (also a sulfonamide) showed the smallest concentration range for the antibiotic compounds. Two hormones, 17 beta-estradiol (E2) and estrone (E1), were detected in influent. Samples were also tested for detection of organic wastewater compounds, pharmaceutical compounds, antibiotic compounds, and hormones in effluent. Indole showed the greatest concentration range and highest concentration, and triphenyl phosphate showed the smallest concentration range for the organic wastewater compounds. Dehydronifedipine showed the greatest concentration range and highest concentration, and warfarin had the smallest concentration range for the pharmaceutical compounds. Anhydro-erythromycin (a macrolide degradation product) showed the greatest concentration range, and sulfadiazine (a sulfonamide) and tetracycline showed the lowest concentration ranges for the antibiotic compounds. One hormone, 17 beta-estradiol (E2), was det

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

PubMed

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

2002-01-01

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

Optical spectroscopy of bulk GaN crystals grown from a Na-Ga melt

NASA Astrophysics Data System (ADS)

Skromme, B. J.; Palle, K. C.; Poweleit, C. D.; Yamane, H.; Aoki, M.; DiSalvo, F. J.

2002-11-01

Colorless transparent platelet and prismatic GaN crystals up to 3-4 mm, grown from a Na-Ga melt (0.6-0.7 mol fraction of Na) at temperatures of 700-800 °C in a modest (5 MPa) pressure of N2, are characterized using Raman scattering, room and low temperature photoluminescence, and reflectance. They exhibit sharp free and bound exciton luminescence features (down to 0.22 meV full width at half maximum), including multiple excited states. Residual Mg and Zn acceptors and a 33.6 meV donor (possibly ON) are identified. Raman spectra suggest free carrier concentrations down to the low to mid 1016 cm-3 range.

Development of a higher-efficiency tubular cavity receiver for direct steam generation on a dish concentrator

NASA Astrophysics Data System (ADS)

Pye, John; Hughes, Graham; Abbasi, Ehsan; Asselineau, Charles-Alexis; Burgess, Greg; Coventry, Joe; Logie, Will; Venn, Felix; Zapata, José

2016-05-01

An integrated model for an axisymmetric helical-coil tubular cavity receiver is presented, incorporating optical ray-tracing for incident solar flux, radiosity analysis for thermal emissions, computational fluid dynamics for external convection, and a one-dimensional hydrodynamic model for internal flow-boiling of water. A receiver efficiency of 98.7% is calculated, for an inlet/outlet temperature range of 60-500 °C, which is the ratio of fluid heating to receiver incident irradiance. The high-efficiency design makes effective use of non-uniform flux in its non-isothermal layout, matching lower temperature regions to areas of lower flux. Full-scale testing of the design will occur in late 2015.

Solutal separation in a binary nanofluid due to thermodiffusion

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

Saghir, M.Z.; Yousefi, T.; Farahbakhsh, B.

2015-03-10

Transport phenomena in porous media have received considerable attention due to an increasing interest in geothermal processes, chemical catalytic reactors, waste storage (especially geological or ocean storage of carbon dioxide), etc. Among others, oil industry has shown an increasing interest in studying diffusion phenomenon. Nanofluid is a term used to describe the suspension of low concentration of metallic and non-metallic nanoparticles in a base fluid. The size of a nanoparticle ranges from 10 to 100nm, and the conventional fluids used are water, ethylene glycol (C{sub 2}H{sub 6}O{sub 2}) or engine oil. Various studies have proven that nanoparticles improve the heatmore » transfer of a base fluid. However, using various nanofluids it has been shown that the results could vary depending on different initial concentrations. The main objective of this paper is to study the diffusion and the thermodiffusion effect in a nanofluid for different fluid/porous media configurations. In this configuration, a liquid layer surrounds a porous layer. The full Brinkman equation coupled with the heat and mass transfer equations have been solved numerically for the porous layer using the finite element technique. The full Navier stokes equation coupled with heat and mass transfer equations have been solved for the liquid layer using the finite element method. A constraint between the liquid and porous layer has been applied to ensure heat flow and mass transfer continuity is maintained. A square cavity filled with hydrocarbon nanofluid of a mixture of fullerene-toluene with varying concentration of fullerene has been subject to different heating conditions. The entire cavity has been considered to be fully wetted with nanofluid. Results have confirmed that in the presence of a nanofluid a heat transfer enhancement is present up to certain initial concentration of the fullerene. The heat convection coefficient has been found to be 16% higher when a nanofluid is used as the working fluid.« less

New Parameterizations for Neutral and Ion-Induced Sulfuric Acid-Water Particle Formation in Nucleation and Kinetic Regimes

NASA Astrophysics Data System (ADS)

Määttänen, Anni; Merikanto, Joonas; Henschel, Henning; Duplissy, Jonathan; Makkonen, Risto; Ortega, Ismael K.; Vehkamäki, Hanna

2018-01-01

We have developed new parameterizations of electrically neutral homogeneous and ion-induced sulfuric acid-water particle formation for large ranges of environmental conditions, based on an improved model that has been validated against a particle formation rate data set produced by Cosmics Leaving OUtdoor Droplets (CLOUD) experiments at European Organization for Nuclear Research (CERN). The model uses a thermodynamically consistent version of the Classical Nucleation Theory normalized using quantum chemical data. Unlike the earlier parameterizations for H2SO4-H2O nucleation, the model is applicable to extreme dry conditions where the one-component sulfuric acid limit is approached. Parameterizations are presented for the critical cluster sulfuric acid mole fraction, the critical cluster radius, the total number of molecules in the critical cluster, and the particle formation rate. If the critical cluster contains only one sulfuric acid molecule, a simple formula for kinetic particle formation can be used: this threshold has also been parameterized. The parameterization for electrically neutral particle formation is valid for the following ranges: temperatures 165-400 K, sulfuric acid concentrations 104-1013 cm-3, and relative humidities 0.001-100%. The ion-induced particle formation parameterization is valid for temperatures 195-400 K, sulfuric acid concentrations 104-1016 cm-3, and relative humidities 10-5-100%. The new parameterizations are thus applicable for the full range of conditions in the Earth's atmosphere relevant for binary sulfuric acid-water particle formation, including both tropospheric and stratospheric conditions. They are also suitable for describing particle formation in the atmosphere of Venus.

Quantifying atmospheric nitrogen outflow from the Front Range of Colorado

NASA Astrophysics Data System (ADS)

Neuman, J. A.; Eilerman, S. J.; Brock, C. A.; Brown, S. S.; Dube, W. P.; Herndon, S. C.; Holloway, J. S.; Nowak, J. B.; Roscioli, J. R.; Ryerson, T. B.; Sjostedt, S. J.; Thompson, C. R.; Trainer, M.; Veres, P. R.; Wild, R. J.

2015-12-01

Reactive nitrogen emitted to the atmosphere from urban, industrial, and agricultural sources can be transported and deposited far from the source regions, affecting vegetation, soils, and water of sensitive ecosystems. Mitigation of atmospheric nitrogen deposition requires emissions characterization and quantification. Ammonia (NH3), a full suite of gas-phase oxidized nitrogen compounds, and particulate matter were measured from an aircraft that flew downwind from concentrated animal feeding operations, oil and gas extraction facilities, and urban areas along the Colorado Front Range in March and April 2015, as part of the Shale Oil and Natural Gas Nexus (SONGNEX) field study. Additionally, NH3 measurements from a fully instrumented aircraft that flew over the same region in July and August 2014 as part of the Front Range Air Pollution and Photochemistry Experiment (FRAPPE) are used to examine atmospheric nitrogen emission and transport. Cross-wind plume transects and altitude profiles were performed over the source regions and 60-240 km downwind. Plumes were transported in the boundary layer with large NH3 mixing ratios (typically 20-100 ppbv) and were tens of km wide. The NH3 in these plumes provided an atmospheric nitrogen burden greater than 0.2 kg N/ha. Nitrogen oxides and their oxidation products and particulate matter were also enhanced in the plumes, but with concentrations substantially less than NH3. With efficient transport followed by wet deposition, these plumes have the potential to provide a large nitrogen input to the neighboring Rocky Mountain National Park, where nitrogen deposition currently exceeds the ecological critical load of 1.5 kg N/ha/yr.

Function-Space-Based Solution Scheme for the Size-Modified Poisson-Boltzmann Equation in Full-Potential DFT.

PubMed

Ringe, Stefan; Oberhofer, Harald; Hille, Christoph; Matera, Sebastian; Reuter, Karsten

2016-08-09

The size-modified Poisson-Boltzmann (MPB) equation is an efficient implicit solvation model which also captures electrolytic solvent effects. It combines an account of the dielectric solvent response with a mean-field description of solvated finite-sized ions. We present a general solution scheme for the MPB equation based on a fast function-space-oriented Newton method and a Green's function preconditioned iterative linear solver. In contrast to popular multigrid solvers, this approach allows us to fully exploit specialized integration grids and optimized integration schemes. We describe a corresponding numerically efficient implementation for the full-potential density-functional theory (DFT) code FHI-aims. We show that together with an additional Stern layer correction the DFT+MPB approach can describe the mean activity coefficient of a KCl aqueous solution over a wide range of concentrations. The high sensitivity of the calculated activity coefficient on the employed ionic parameters thereby suggests to use extensively tabulated experimental activity coefficients of salt solutions for a systematic parametrization protocol.

Wet extraction of heavy metals and chloride from MSWI and straw combustion fly ashes

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

Aguiar del Toro, M.; Calmano, W.; Ecke, H.

2009-09-15

Fly ash residues from combustion often do not meet the criteria neither for reuse as construction materials nor landfilling as non-hazardous waste, mainly because of the high concentration of heavy metals and chlorides. This work aimed to technically evaluate an innovative wet treatment process for the extraction of chloride (Cl{sup -}), cadmium (Cd), copper (Cu), lead (Pb) and zinc (Zn) from fly ashes from a municipal solid waste incineration (MSWI) plant and from a straw combustion (SC) facility. Factors investigated were liquid/solid (L/S) ratio, full carbonation (CO{sub 2} treatment), influence of pH and leaching time, using a two-level full factorialmore » design. The most significant factor for all responses was low pH, followed by L/S ratio. Multiple linear regression models describing the variation in extraction data had R{sup 2} values ranging from 58% to 98%. An optimization of the element extraction models was performed and a set of treatment conditions is suggested.« less

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

PubMed Central

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

1991-01-01

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

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

PubMed

Dahlberg, Daniel; Ivanovic, Jugoslav; Hassel, Bjørnar

2014-04-01

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

Measurement of variation in soil solute tracer concentration across a range of effective pore sizes

USGS Publications Warehouse

Harvey, Judson W.

1993-01-01

Solute transport concepts in soil are based on speculation that solutes are distributed nonuniformly within large and small pores. Solute concentrations have not previously been measured across a range of pore sizes and examined in relation to soil hydrological properties. For this study, modified pressure cells were used to measure variation in concentration of a solute tracer across a range of pore sizes. Intact cores were removed from the site of a field tracer experiment, and soil water was eluted from 10 or more discrete classes of pore size. Simultaneous changes in water content and unsaturated hydraulic conductivity were determined on cores using standard pressure cell techniques. Bromide tracer concentration varied by as much as 100% across the range of pore sizes sampled. Immediately following application of the bromide tracer on field plots, bromide was most concentrated in the largest pores; concentrations were lower in pores of progressively smaller sizes. After 27 days, bromide was most dilute in the largest pores and concentrations were higher in the smaller pores. A sharp, threefold decrease in specific water capacity during elution indicated separation of two major pore size classes at a pressure of 47 cm H2O and a corresponding effective pore diameter of 70 μm. Variation in tracer concentration, on the other hand, was spread across the entire range of pore sizes investigated in this study. A two-porosity characterization of the transport domain, based on water retention criteria, only broadly characterized the pattern of variation in tracer concentration across pore size classes during transport through a macroporous soil.

Suspected hypoglycaemia in out patient practice: accuracy of dried blood spot analysis.

PubMed

Parker, D R; Bargiota, A; Cowan, F J; Corrall, R J

1997-12-01

The assay of dried blood spots on filter paper to determine blood glucose concentration has been used to detect hypoglycaemia in out patients. We assessed the accuracy of this approach in assaying blood glucose concentrations in the hypoglycaemic range. Volunteers were rendered hypoglycaemic by intravenous infusion of insulin. The glucose concentration in simultaneously taken blood samples was measured either fresh or after drying on filter paper. Twenty-four healthy young volunteers and 9 patients with insulin-dependent diabetes were studied. Plasma glucose concentrations were measured using a standard auto analyser glucose oxidase method. Whole blood taken simultaneously was placed on prepared filter paper and allowed to dry; glucose concentration was then measured using a well-established technique. A correction factor was applied to convert the glucose concentration of plasma to that of whole blood. The relationship between glucose concentrations measured by the two methods was determined by regression coefficient. In the unequivocally hypoglycaemic range (plasma < or = 2.5 mmol/l), corrected dried blood spot glucose concentrations significantly correlated with standard plasma glucose concentrations (r = 0.81; P < 0.001). The dried blood spot method had a sensitivity of 91%. In the range designated probable hypoglycaemia (plasma < or = 3.3 mmol/l), there was also significant correlation (r = 0.90; P < 0.001) and the sensitivity was 96%. The specificity of the dried blood spot method was 100% in both ranges. Measurement of glucose concentrations in dried blood spots is specific and sensitive in the hypoglycaemic range. The present study indicates that hypoglycaemia may be excluded or confirmed respectively when levels in excess of 3.7 or below 2.8 mmol/l are found in uncorrected dried blood spot analysis.

Normal lactate concentration range in the neonatal brain.

PubMed

Tomiyasu, Moyoko; Aida, Noriko; Shibasaki, Jun; Tachibana, Yasuhiko; Endo, Mamiko; Nozawa, Kumiko; Shimizu, Eiji; Tsuji, Hiroshi; Obata, Takayuki

2016-11-01

Lactate peaks are occasionally observed during in vivo magnetic resonance spectroscopy (MRS) scans of the neonatal brain, even in healthy patients. The purpose of this study was to investigate the normal range of neonatal brain lactate concentration, as a definitive normal range would be clinically valuable. Using a clinical 3T scanner (echo/repetition times, 30/5000ms), single-voxel MRS data were obtained from the basal ganglia (BG) and centrum semiovale (CS) in 48 healthy neonates (postconceptional age (PCA), 30-43weeks), nine infants (age, 1-12months old), and 20 children (age, 4-15years). Lactate concentrations were calculated using an MRS signal quantification program, LCModel. Correlations between regional lactate concentration and PCA (neonates), or age (all subjects) were investigated. Absolute lactate concentrations of the BG and CS were as follows: neonates, 0.77mM (0-2.02) [median (range)] and 0.77 (0-1.42), respectively; infants, 0.38 (0-0.79) and 0.49 (0.17-1.17); and children, 0.17 (0-0.76) and 0.22 (0-0.80). Overall, subjects' lactate concentrations decreased significantly with age (Spearman: BG, n=61, ρ=-0.38, p=0.003; CS, n=68, ρ=-0.57, p<0.001). However, during the neonatal period no correlations were detected between lactate concentration in either region and PCA. We determined normal ranges of neonatal lactate concentration, which may prove useful for diagnostic purposes. Further studies regarding changes in brain lactate concentration during development would help clarify the reasons for higher concentrations observed during the neonatal period, and contribute to improvements in diagnoses. Copyright © 2016 Elsevier Inc. All rights reserved.

Plasma concentrations of midazolam during continuous subcutaneous administration in palliative care.

PubMed

Bleasel, M D; Peterson, G M; Dunne, P F

1994-01-01

We have investigated the steady-state plasma concentrations of midazolam during continuous subcutaneous administration in palliative care. Using a sensitive gas chromatography with electron capture detector assay, plasma concentrations of midazolam were measured in 11 patients (median age 68 years; range 47-82 years; six females) receiving the drug by continuous subcutaneous infusion (median rate 20 mg/day; range 10-60 mg/day). While not significant, the infusion rate tended to decrease with increasing age of the patient (Spearman's p = -0.51; p = 0.11). The steady-state plasma concentration range was 10-147 ng/ml, with a median of 30 ng/ml. Infusion rates and plasma concentrations of midazolam were correlated (Spearman's p = 0.71; p < 0.05). No other significant relationships were found between plasma concentrations and the variables of age, sex and liver function.

Predicting heavy metal concentrations in soils and plants using field spectrophotometry

NASA Astrophysics Data System (ADS)

Muradyan, V.; Tepanosyan, G.; Asmaryan, Sh.; Sahakyan, L.; Saghatelyan, A.; Warner, T. A.

2017-09-01

Aim of this study is to predict heavy metal (HM) concentrations in soils and plants using field remote sensing methods. The studied sites were an industrial town of Kajaran and city of Yerevan. The research also included sampling of soils and leaves of two tree species exposed to different pollution levels and determination of contents of HM in lab conditions. The obtained spectral values were then collated with contents of HM in Kajaran soils and the tree leaves sampled in Yerevan, and statistical analysis was done. Consequently, Zn and Pb have a negative correlation coefficient (p <0.01) in a 2498 nm spectral range for soils. Pb has a significantly higher correlation at red edge for plants. A regression models and artificial neural network (ANN) for HM prediction were developed. Good results were obtained for the best stress sensitive spectral band ANN (R2 0.9, RPD 2.0), Simple Linear Regression (SLR) and Partial Least Squares Regression (PLSR) (R2 0.7, RPD 1.4) models. Multiple Linear Regression (MLR) model was not applicable to predict Pb and Zn concentrations in soils in this research. Almost all full spectrum PLS models provide good calibration and validation results (RPD>1.4). Full spectrum ANN models are characterized by excellent calibration R2, rRMSE and RPD (0.9; 0.1 and >2.5 respectively). For prediction of Pb and Ni contents in plants SLR and PLS models were used. The latter provide almost the same results. Our findings indicate that it is possible to make coarse direct estimation of HM content in soils and plants using rapid and economic reflectance spectroscopy.

The clinical pattern of nephrotic syndrome in children has no effect on the concentration of soluble urokinase receptor (suPAR) in serum and urine.

PubMed

Ochocińska, Agnieszka; Jarmużek, Wioletta; Janas, Roman

2018-04-23

Concentration of soluble urokinase receptor (suPAR) was regarded as viable marker to differentiate the focal segmental glomerulosclerosis (FSGS) from other glomerulopathies and also as predictive parameter for progression of renal disease. The aim of this study was to evaluate serum and urine (s)(u)suPAR concentration in steroid-sensitive and steroid-resistant nephrotic children treated with different (double and triple-drug) regimens. Overall 43 children were evaluated including 14 patients with steroid-resistant nephrotic syndrome (SRNS) aged 9±6 years and 29 with steroid-sensitive nephrotic syndrome (SSNS) aged 9±5 years, as well as control group (n=59). The concentration of suPAR was measured with ELISA kit (R∧D Systems Inc.). There was no difference in serum suPAR level between SRNS (6404, range: 4613-9575 pg/mL) and SSNS (5745, range: 4666-8246 pg/mL) patients, and also in urinary suPAR: SRNS (2877, range: 847- 19121 pg/mL) and SSNS (2854, range: 328-7434 pg/mL), respectively. There was no statistically significant difference in serum biomarker concentrations between patients with severe course of the disease, in combination therapy, with three drugs: CsA + MMF + Pred (5968, range: 4613-9575 pg/mL) in comparison with patients receiving double therapy: CsA + Pred or MMF + Pred (5449, range: 4666-6623 pg/mL, 5905, range: 5102-6730 pg/mL, respectively). SuPAR concentration in the urine of patients treated with Pred + MMF was lower (1493, range: 328-4444 pg/mL) than in patients receiving Pred + CsA (3193, range: 629-7434 pg/mL), as well as lower than in patients with triple combination of drugs (3318, range: 448-5570 pg/mL), however the difference was not statistically significant. Serum and urine concentration of suPAR did not different between different clinical patterns of nephrotic syndrome in children, regardless the immunosuppressive treatment used. © 2018 MEDPRESS.

Relation of concentration and exposure time to the efficacy of niclosamide against larval sea lampreys (Petromyzon marinus)

USGS Publications Warehouse

Scholefield, R.J.; Bergstedt, R.A.; Bills, T.D.

2003-01-01

The efficacy of 2’, 5-dichloro-4’-nitrosalicylanilide (niclosamide) at various concentrations and exposure times was tested against free-swimming larval sea lampreys (Petromyzon marinus) at 12°C and 17°C in Lake Huron water. Concentrations of niclosamide in test solutions ranged from 0.46 to 4.7 mg/L with pH 7.8 to 8.3, total alkalinity 78 to 88 mg/L as CaCO3, and total hardness 95 to 105 mg/L as CaCO3. In each test, six groups of larvae were exposed to a single concentration of niclosamide for times ranging from 30 s to 30 min. Exposure time was treated as the dose and, for each concentration tested, the exposure time necessary to kill 50 and 99.9% of larvae (ET50 and ET99.9) was determined. Linear regressions of the log10-transformed ET50 and ET99.9 on the log10-transformed niclosamide concentrations were significant at both temperatures with r2ranging from 0.94 to 0.98. The predicted ET50 ranged from 58 sec to 21.7 min and the ET99.9 ranged from 2.5 to 43.5 min across the concentrations and temperatures tested. Niclosamide required a significantly longer time to kill larvae at 12°C than at 17°C.

Heavy-metal contamination on training ranges at the Grafenwoehr Training Area, Germany

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

Zellmer, S.D.; Schneider, J.F.

1993-05-01

Large quantities of lead and other heavy metals are deposited in the environment of weapons ranges during training exercises. This study was conducted to determine the type, degree, and extent of heavy-metal contamination on selected handgun, rifle, and hand-grenade ranges at Grafenwoehr Training Area, Germany. Soil, vegetation, and surface-water samples were collected and analyzed using the inductively-coupled plasma atomic-emission spectroscopy (ICP-AES) method and the toxic characterization leaching procedure (TCLP). The ICP-AES results show that above-normal levels of lead and copper are in the surface soil at the handgun range, high concentrations of lead and copper are in the berm andmore » soil surface at the rifle range, and elevated levels of cadmium and above-normal concentrations of arsenic, copper, and zinc are present in the surface soil at the hand-grenade range. The TCLP results show that surface soils can be considered hazardous waste because of lead content at the rifle range and because of cadmium concentration at the hand-grenade range. Vegetation at the handgun and rifle ranges has above-normal concentrations of lead. At the hand-grenade range, both vegetation and surface water have high levels of cadmium. A hand-held X-ray fluorescence (XRF) spectrum analyzer was used to measure lead concentrations in soils in a field test of the method. Comparison of XRF readings with ICP-AES results for lead indicate that the accuracy and precision of the hand-held XRF unit must improve before the unit can be used as more than a screening tool. Results of this study show that heavy-metal contamination at all three ranges is limited to the surface soil; heavy metals are not being leached into the soil profile or transported into adjacent areas.« less

Trans-Himalayan water contributions to river discharge

NASA Astrophysics Data System (ADS)

Andermann, Christoff; Stieglitz, Thomas; Schuessler, Jan A.; Parajouli, Binod

2017-04-01

Hydrological processes in high mountains are not well understood. Groundwater is commonly considered to be of little importance in the mountain water balance, while direct runoff, snow and ice melt are thought to be the principal hydrological buffer. We present new insights into hydrological fluxes between major reservoirs in a trans-Himalayan catchment. The study area is the Kali Gandaki catchment, rising in the dry Tibetan interior, carving through the high Himalayas and draining the full width of the foothills to the Ganges foreland. The catchment has a well-defined monsoon climate, with pronounced annual wet and dry seasons and a clear separation of wind- and leeward regions. We have sampled the main river and its tributaries as well as several springs during the four hydrological seasons (winter, pre-monsoon, monsoon, post-monsoon). We have measured major element abundances as well as 222Rn in situ, as a tracer for groundwater contribution. These measurements are placed in a context of topographic analyses as well as continuous discharge and precipitation measurements. Furthermore, we have equipped two sites with continuous water samplers, sampling over > 4 monsoon seasons, allowing us to resolve the seasonal hydrological dynamic range on a very high temporal resolution. Chemical fluxes vary spatially over several orders of magnitude, showing a systematic downstream dilution trend for most major elements during all hydrological seasons. High initial concentrations derive from evaporite deposits in the uppermost part of the catchment, constituting a large scale, natural salt tracer experiment. The well-defined decline of solute concentrations along the main river, paired with constraints on the composition of lateral water inputs downstream allow the calculation of the spatial distribution of additional hydrological fluxes, by applying end member mixing modeling. Continuous river stage and bulk dissolved load (electrical conductivity) monitoring depict well-defined diurnal cycles in water temperature, stage level and water chemistry. These diurnal cycles have a profound impact on the chemical concentrations and need to be corrected for to estimate representative geochemical fluxes for the full river and end member mixing modeling. Radon and trace element data indicate that groundwater contributions are primarily associated with the main tectonic structures of the Himalayan range, but also concentrate on the steep southern mountain front, and that groundwater outflow from the Lesser Himalayas is limited during baseflow season. Over the seasons the chemical dilution signature across the Himalayan range is persistent. However, specific elements have temporally distinct dilution signatures highlighting the alternating contribution of different hydrological compartments over the annual hydrological cycle. Our analysis allows to decipher the hydrological contribution of different water reservoirs to the surface water discharge in rivers, along a major Himalayan stream. Our results highlight the volumetric importance of a high mountain deep-groundwater storage compartment across the Himalayan mountain belt and provides first order quantification of groundwater contribution to stream flow.

Prenatal Exposure to Organophosphate Pesticides and IQ in 7-Year-Old Children

PubMed Central

Bouchard, Maryse F.; Chevrier, Jonathan; Harley, Kim G.; Kogut, Katherine; Vedar, Michelle; Calderon, Norma; Trujillo, Celina; Johnson, Caroline; Bradman, Asa; Barr, Dana Boyd

2011-01-01

Context: Organophosphate (OP) pesticides are neurotoxic at high doses. Few studies have examined whether chronic exposure at lower levels could adversely affect children’s cognitive development. Objective: We examined associations between prenatal and postnatal exposure to OP pesticides and cognitive abilities in school-age children. Methods: We conducted a birth cohort study (Center for the Health Assessment of Mothers and Children of Salinas study) among predominantly Latino farmworker families from an agricultural community in California. We assessed exposure to OP pesticides by measuring dialkyl phosphate (DAP) metabolites in urine collected during pregnancy and from children at 6 months and 1, 2, 3.5, and 5 years of age. We administered the Wechsler Intelligence Scale for Children, 4th edition, to 329 children 7 years of age. Analyses were adjusted for maternal education and intelligence, Home Observation for Measurement of the Environment score, and language of cognitive assessment. Results: Urinary DAP concentrations measured during the first and second half of pregnancy had similar relations to cognitive scores, so we used the average of concentrations measured during pregnancy in further analyses. Averaged maternal DAP concentrations were associated with poorer scores for Working Memory, Processing Speed, Verbal Comprehension, Perceptual Reasoning, and Full-Scale intelligence quotient (IQ). Children in the highest quintile of maternal DAP concentrations had an average deficit of 7.0 IQ points compared with those in the lowest quintile. However, children’s urinary DAP concentrations were not consistently associated with cognitive scores. Conclusions: Prenatal but not postnatal urinary DAP concentrations were associated with poorer intellectual development in 7-year-old children. Maternal urinary DAP concentrations in the present study were higher but nonetheless within the range of levels measured in the general U.S. population. PMID:21507776

The MUSIC of CLASH: Predictions on the Concentration-Mass Relation

NASA Astrophysics Data System (ADS)

Meneghetti, M.; Rasia, E.; Vega, J.; Merten, J.; Postman, M.; Yepes, G.; Sembolini, F.; Donahue, M.; Ettori, S.; Umetsu, K.; Balestra, I.; Bartelmann, M.; Benítez, N.; Biviano, A.; Bouwens, R.; Bradley, L.; Broadhurst, T.; Coe, D.; Czakon, N.; De Petris, M.; Ford, H.; Giocoli, C.; Gottlöber, S.; Grillo, C.; Infante, L.; Jouvel, S.; Kelson, D.; Koekemoer, A.; Lahav, O.; Lemze, D.; Medezinski, E.; Melchior, P.; Mercurio, A.; Molino, A.; Moscardini, L.; Monna, A.; Moustakas, J.; Moustakas, L. A.; Nonino, M.; Rhodes, J.; Rosati, P.; Sayers, J.; Seitz, S.; Zheng, W.; Zitrin, A.

2014-12-01

We present an analysis of the MUSIC-2 N-body/hydrodynamical simulations aimed at estimating the expected concentration-mass relation for the CLASH (Cluster Lensing and Supernova Survey with Hubble) cluster sample. We study nearly 1,400 halos simulated at high spatial and mass resolution. We study the shape of both their density and surface-density profiles and fit them with a variety of radial functions, including the Navarro-Frenk-White (NFW), the generalized NFW, and the Einasto density profiles. We derive concentrations and masses from these fits. We produce simulated Chandra observations of the halos, and we use them to identify objects resembling the X-ray morphologies and masses of the clusters in the CLASH X-ray-selected sample. We also derive a concentration-mass relation for strong-lensing clusters. We find that the sample of simulated halos that resembles the X-ray morphology of the CLASH clusters is composed mainly of relaxed halos, but it also contains a significant fraction of unrelaxed systems. For such a heterogeneous sample we measure an average two-dimensional concentration that is ~11% higher than is found for the full sample of simulated halos. After accounting for projection and selection effects, the average NFW concentrations of CLASH clusters are expected to be intermediate between those predicted in three dimensions for relaxed and super-relaxed halos. Matching the simulations to the individual CLASH clusters on the basis of the X-ray morphology, we expect that the NFW concentrations recovered from the lensing analysis of the CLASH clusters are in the range [3-6], with an average value of 3.87 and a standard deviation of 0.61.

The music of clash: predictions on the concentration-mass relation

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

Meneghetti, M.; Rasia, E.; Vega, J.

We present an analysis of the MUSIC-2 N-body/hydrodynamical simulations aimed at estimating the expected concentration-mass relation for the CLASH (Cluster Lensing and Supernova Survey with Hubble) cluster sample. We study nearly 1,400 halos simulated at high spatial and mass resolution. We study the shape of both their density and surface-density profiles and fit them with a variety of radial functions, including the Navarro-Frenk-White (NFW), the generalized NFW, and the Einasto density profiles. We derive concentrations and masses from these fits. We produce simulated Chandra observations of the halos, and we use them to identify objects resembling the X-ray morphologies andmore » masses of the clusters in the CLASH X-ray-selected sample. We also derive a concentration-mass relation for strong-lensing clusters. We find that the sample of simulated halos that resembles the X-ray morphology of the CLASH clusters is composed mainly of relaxed halos, but it also contains a significant fraction of unrelaxed systems. For such a heterogeneous sample we measure an average two-dimensional concentration that is ∼11% higher than is found for the full sample of simulated halos. After accounting for projection and selection effects, the average NFW concentrations of CLASH clusters are expected to be intermediate between those predicted in three dimensions for relaxed and super-relaxed halos. Matching the simulations to the individual CLASH clusters on the basis of the X-ray morphology, we expect that the NFW concentrations recovered from the lensing analysis of the CLASH clusters are in the range [3-6], with an average value of 3.87 and a standard deviation of 0.61.« less

Comparison of parameters affecting GNP-loaded choroidal melanoma dosimetry; Monte Carlo study

NASA Astrophysics Data System (ADS)

Sharabiani, Marjan; Asadi, Somayeh; Barghi, Amir Rahnamai; Vaezzadeh, Mehdi

2018-04-01

The current study reports the results of tumor dosimetry in the presence of gold nanoparticles (GNPs) with different sizes and concentrations. Due to limited number of works carried out on the brachytherapy of choroidal melanoma in combination with GNPs, this study was performed to determine the optimum size and concentration for GNPs which contributes the highest dose deposition in tumor region, using two phantom test cases namely water phantom and a full Monte Carlo model of human eye. Both water and human eye phantoms were simulated with MCNP5 code. Tumor dosimetry was performed for a typical point photon source with an energy of 0.38 MeV as a high energy source and 103Pd brachytherapy source with an average energy of 0.021 MeV as a low energy source in water phantom and eye phantom respectively. Such a dosimetry was done for different sizes and concentrations of GNPs. For all of the diameters, increase in concentration of GNPs resulted in an increase in dose deposited in the region of interest. In a certain concentration, GNPs with larger diameters contributed more dose to the tumor region, which was more pronounced using eye phantom. 100 nm was reported as the optimum size in order to achieve the highest energy deposition within the target. This work investigated the optimum parameters affecting macroscopic dose enhancement in GNP-aided brachytherapy of choroidal melanoma. The current work also had implications on using low energy photon sources in the presence of GNPs to acquire the highest dose enhancement. This study is conducted through four different sizes and concentrations of GNPs. Considering the sensitivity of human eye tissue, in order to report the precise optimum parameters affecting radiosensitivity, a comprehensive study on a wide range of sizes and concentrations are required.

The relationship of nitrate concentrations in streams to row crop land use in Iowa

USGS Publications Warehouse

Schilling, K.E.; Libra, R.D.

2000-01-01

The relationship between row crop land use and nitrate N concentrations in surface water was evaluated for 15 Iowa watersheds ranging from 1002 to 2774 km2 and 10 smaller watersheds ranging from 47 to 775 km2 for the period 1996 to 1998. The percentage of land in row crop varied from 24 to >87% in the 15 large watersheds, and mean annual NO3-N concentrations ranged from 0.5 to 10.8 mg/L. In the small watersheds, row crop percentage varied from 28 to 87% and mean annual NO3-N concentrations ranged from 3.0 to 10.5 mg/L. In both cases, nitrate N concentrations were directly related to the percentage of row crop in the watershed (p 87% in the 15 large watersheds, and mean annual NO3-N concentrations ranged from 0.5 to 10.8 mg/L. In the small watersheds, row crop percentage varied from 28 to 87% and mean annual NO3-N concentrations ranged from 3.0 to 10.5 mg/L. In both cases, nitrate N concentrations were directly related to the percentage of row crop in the watershed (p<0.0003). Linear regression showed similar slope for both sets of watersheds (0.11) suggesting that average annual surface water nitrate concentrations in Iowa, and possibly similar agricultural areas in the midwestern USA, can be approximated by multiplying a watershed's row crop percentage by 0.1. Comparing the Iowa watershed data with similar data collected at a subwatershed scale in Iowa (0.1 to 8.1 km2) and a larger midcontinent scale (7300 to 237 100 km2) suggests that watershed scale affects the relationship of nitrate concentration and land use. The slope of nitrate concentration versus row crop percentage decreases with increasing watershed size.Mean nitrate concentrations and row crop land use were summarized for 15 larger and ten smaller watersheds in Iowa, and the relationship between NO3 concentration and land use was examined. Linear regression of mean NO3 concentration and percent row crop was highly significant for both sets of watershed data, but a stronger correlation was noted in the small-watershed data. Both data sets suggested that mean annual surface-water NO3 concentrations in the state could be approximated by multiplying the watershed's percent row crop by 0.1. The slope of NO3 concentration versus row crop percentage appeared to decrease with increasing watershed size.

Metolachlor and its metabolites in tile drain and stream runoff in the canajoharie creek watershed

USGS Publications Warehouse

Phillips, P.J.; Wall, G.R.; Thurman, E.M.; Eckhardt, D.A.; Vanhoesen, J.

1999-01-01

Water samples collected during April-November 1997 from tile drains beneath cultivated fields in central New York indicate that two metabolites of the herbicide metolachlor-metolachlor ESA (ethanesulfonic acid) and OA (oxanilic acid) can persist in agricultural soils for 4 or more years after application and that fine-grained soils favor the transport of metolachlor ESA over metolachlor and metolachlor OA. Concentrations of metolachlor ESA from the tile drains ranged from 3.27 to 23.4 ??g/L (200 1800 times higher than those of metolachlor), metolachlor OA concentrations ranged from 1.14 to 13.5 ??g/L, and metolachlor concentrations ranged from less than 0.01 to 0.1 ??g/L. In the receiving stream, concentrations of metolachlor ESA were always below 0.6 ??g/L except during a November storm, when concentrations reached 0.85 ??g/L. Concentrations of metolachlor ESA in the stream were 2 45 times higher than those of metolachlor, reflecting the greater relative concentrations of metolachlor in surface water runoff than in tile drain runoff. These results are consistent with findings in other studies that acetanilide herbicide degredates are found in much higher concentrations than parent compounds in both surface water and groundwater.Water samples collected during April-November 1997 from tile drains beneath cultivated fields in central New York indicate that two metabolites of the herbicide metolachlor-metolachlor ESA (ethanesulfonic acid) and OA (oxanilic acid)-can persist in agricultural soils for 4 or more years after application and that fine-grained soils favor the transport of metolachlor ESA over metolachlor and metolachlor OA. Concentrations of metolachlor ESA from the tile drains ranged from 3.27 to 23.4 ??g/L (200-1800 times higher than those of metolachlor), metolachlor OA concentrations ranged from 1.14 to 13.5 ??g/L, and metolachlor concentrations ranged from less than 0.01 to 0.1 ??g/L. In the receiving stream, concentrations of metolachlor ESA were always below 0.6 ??g/L except during a November storm, when concentrations reached 0.85 ??g/L. Concentrations of metolachlor ESA in the stream were 2-45 times higher than those of metolachlor, reflecting the greater relative concentrations of metolachlor in surface water runoff than in tile drain runoff. These results are consistent with findings in other studies that acetanilide herbicide degredates are found in much higher concentrations than parent compounds in both surface water and groundwater.

Adsorption of N-nitrosodimethylamine precursors by powdered and granular activated carbon.

PubMed

Hanigan, David; Zhang, Jinwei; Herckes, Pierre; Krasner, Stuart W; Chen, Chao; Westerhoff, Paul

2012-11-20

Activated carbon (AC) has been shown to remove precursors of halogenated disinfection byproducts. Granular and powdered activated carbon (GAC, PAC) were investigated for their potential to adsorb N-nitrosodimethylamine (NDMA) precursors from blends of river water and effluent from a wastewater treatment plant (WWTP). At bench scale, waters were exposed to lignite or bituminous AC, either as PAC in bottle point experiments or as GAC in rapid small-scale column tests (RSSCTs). NDMA formation potential (FP) was used as a surrogate for precursor removal. NDMA FP was reduced by 37, 59, and 91% with 3, 8, and 75 mg/L of one PAC, respectively, with a 4-h contact time. In RSSCTs and in full-scale GAC contactors, NDMA FP removal always exceeded that of the bulk dissolved organic carbon (DOC) and UV absorbance at 254 nm. For example, whereas DOC breakthrough exceeded 90% of its influent concentration after 10,000 bed volumes of operation in an RSSCT, NDMA FP was less than 40% of influent concentration after the same bed life of the GAC. At full or pilot scale, high NDMA FP reduction ranging from >60 to >90% was achieved across GAC contactors, dependent upon the GAC bed life and/or use of a preoxidant (chlorine or ozone). In all experiments, NDMA formation was not reduced to zero, which suggests that although some precursors are strongly sorbed, others are not. This is among the first studies to show that AC is capable of adsorbing NDMA precursors, but further research is needed to better understand NDMA precursor chemical properties (e.g., hydrophobicity, molecular size) and evaluate how best to incorporate this finding into full-scale designs and practice.

Ferric Oxide Mediated Formation of PCDD/Fs from 2-Monochlorophenol

PubMed Central

Nganai, Shadrack; Lomnicki, Slawo; Dellinger, Barry

2012-01-01

The copper oxide, surface-mediated formation of polychlorinated dibenzop-dioxins and dibenzofurans (PCDD/F) from precursors such as chlorinated phenols is considered to be a major source of PCDD/F emissions from combustion sources. In spite of being present at 2–50x higher concentrations than copper oxide, virtually no studies of the iron oxide-mediated formation of PCDD/F have been reported in the literature. We have performed packed bed, flow reactor studies of the reaction of 50 ppm gas phase 2-monochlorophenol (2-MCP) over a surface of 5% iron oxide on silica over a temperature range of 200–500 °C. Dibenzo-p-dioxin (DD), 1-monochlorodibenzo-p-dioxin (1-MCDD), 4,6-dichlorodibenzofuran (4,6-DCDF), and dibenzofuran (DF) were formed in maximum yields of 0.1, 0.2, 0.3, and 0.4 %, respectively. The yield of PCDD/F over iron oxide peaked at temperatures 50–100 °C higher in temperature than over copper oxide. The maximum yields of DD, 1-MCDD and 4,6-DCDF were 2x and 5x higher over iron oxide, respectively, than over copper oxide, while DF was not observed at all for copper oxide. The resulting PCDD/PCDF ratio was 0.39 versus 1.2 observed for iron oxide and copper oxide, respectively, which is in agreement with PCDD to PCDF ratios in full-scale combustors that are typically ≪1. The combination of 2–50x higher concentrations of iron oxide than copper oxide in most full-scale combustors and 2.5x higher yields of PCDD/F observed in the laboratory, suggest that iron oxide may contribute as much as 5–125x more than copper oxide to the emissions of PCDD/F from full-scale combustors. PMID:19238966

Effects of Urban Development on Water-Quality in the Piedmont of North Carolina-- The NAWQA Urban Land-Use Gradient Study

NASA Astrophysics Data System (ADS)

Harned, D. A.; Cuffney, T. F.; Giddings, E. M.; McMahon, G.

2004-12-01

A study of urban basins located in the Piedmont of North Carolina is underway as part of the U. S. Geological Survey National Water-Quality Assessment (NAWQA) to determine the relation between level of urban development and water quality. Data were collected from 30 basins on water chemistry (nutrient, pesticide, and ion concentrations), geomorphic and habitat characteristics, hydrologic stage, discharge, water temperature, pH, dissolved-oxygen concentration, specific conductance, benthic algae, invertebrate communities, and fish communities. Collection frequency for water chemistry ranged from 2 samples (at 20 sites) to 6 samples (at 10 sites). Biological data were collected in each basin twice. Investigation of the effects of urbanization on water quality must control for the effects of natural factors, while varying the degree of urbanization between study basins. A regional framework was used to control variability in natural factors that influence water-quality. The urban intensity in each basin was measured by using an index to integrate information on human influences. The Urban Index includes information about land cover, infrastructure, population, and socioeconomic characteristics. Sites were selected to represent the full gradient of undeveloped to fully urbanized basins. A preliminary review of the stream water-chemistry data indicates distinct relations between ionic composition and the Urban Index. Mean specific conductance was positively correlated with the Urban Index (Spearman correlation coefficient (r) = 0.77; 95-percent confidence limits (95CL) 0.61 - 0.93; probability (pr) <0.0001; N=30). Specific conductance ranged from 56 microsiemens (uS) at the least developed site to 607 uS at the most developed site. Dissolved sulfate (r=0.74; 95CL 0.57 - 0.91; pr <0.0001) and chloride (r=0.71; 95CL 0.52 - 0.90; pr <0.0001) were also positively correlated with the Urban Index. Sulfate ranged from 2.3 to 66 milligrams per liter (mg/L), and chloride ranged from 3.5 to 96 mg/L. Urban sources of sulfate include domestic sewage and emissions from the combustion of automotive and diesel fuels. Sources of chloride include sewage and road salting. pH was positively correlated with the Urban Index (r=0.60; 95CL 0.38 - 0.84; pr= 0.0005) with a range from 6.5 at the least urban site to 7.5 at the most urban site. The increase in pH may be due in part to conversion of organic forest soils to less acidic soils of urban lawns. The overall trend of increasing total dissolved nitrogen (r=0.46; 95CL 0.12 - 0.80; pr=0.0103) and nitrite plus nitrate (r=0.46; 95CL 0.09 - 0.83; pr=0.0109) concentrations, with increasing Urban Index may reflect sources such as sewage and lawn fertilizer use in the more urban basins. However, some of the least urban basins also had elevated nitrogen concentrations reflecting possible agricultural influences such as fertilizer use and animal waste. Total nitrogen concentration ranged from 0.31 to 14 mg/L. Unit-area stream discharge during low-flow periods was negatively correlated with the Urban Index (r= -0.56; 95CL -0.74 - -0.37; pr=0.0014). Reduced discharge with greater urban development may be a result of reduced infiltration caused by impervious surfaces. Unit discharge ranged from 0.47 to 2.27 cubic feet per second per square mile of drainage area.

Serum chemistry comparisons between captive and free-ranging giraffes (Giraffa camelopardalis).

PubMed

Schmidt, Debra A; Barbiers, Robyn B; Ellersieck, Mark R; Ball, Ray L; Koutsos, Elizabeth A; Griffin, Mark E; Grobler, Douw; Citino, Scott B; Bush, Mitchell

2011-03-01

Serum chemistry analyses were compared between captive and free-ranging giraffes (Giraffa camelopardalis) in an attempt to better understand some of the medical issues seen with captive giraffes. Illnesses, including peracute mortality, energy malnutrition, pancreatic disease, urolithiasis, hoof disease, and severe intestinal parasitism, may be related to zoo nutrition and management issues. Serum samples were collected from 20 captive giraffes at 10 United States institutions. Thirteen of the captive animal samples were collected from animals trained for blood collection; seven were banked samples obtained from a previous serum collection. These samples were compared with serum samples collected from 24 free-ranging giraffes in South Africa. Differences between captive and free-ranging giraffes, males and females, and adults and subadults were analyzed by using a 2 x 2 x 2 factorial and Fisher's least significant difference for mean separation; when necessary variables were ranked and analyzed via analysis of variance. Potassium and bilirubin concentrations and alanine aminotransferase (ALT) activities were different between captive and free-ranging giraffes, but all fell within normal bovid reference ranges. The average glucose concentration was significantly elevated in free-ranging giraffes (161 mg/dl) compared with captive giraffes (113 mg/dl). All giraffes in this study had glucose concentrations higher than bovine (42-75 mg/ dl) and caprine (48-76 mg/dl) reference ranges. Differences were also seen in lipase, chloride, and magnesium though these findings are likely not clinically significant. There were no differences detected between sexes. Adults had higher concentrations of potassium, total protein, globulins, and chloride and higher gamma glutamyltransferase activities, whereas subadults had higher concentrations of phosphorus. Within the captive group, nonimmobilized animals had higher concentrations of total protein and globulins. Captive giraffe diets need further investigation to determine if the differences seen in this study, especially glucose and bilirubin concentrations and ALT activities, may result in some health problems often seen in captive giraffes.

Model function to calculate the refractive index of native hemoglobin in the wavelength range of 250-1100 nm dependent on concentration.

PubMed

Friebel, Moritz; Meinke, Martina

2006-04-20

The real part of the complex refractive index of oxygenated native hemoglobin solutions dependent on concentration was determined in the wavelength range 250 to 1100 nm by Fresnel reflectance measurements. The hemoglobin solution was produced by physical hemolysis of human erythrocytes followed by ultracentrifugation and filtration. A model function is presented for calculating the refractive index of hemoglobin solutions depending on concentration in the wavelength range 250 to 1100 nm.

Correlation and toxicological inference of trace elements in tissues from stranded and free-ranging bottlenose dolphins (Tursiops truncatus).

PubMed

Stavros, Hui-Chen W; Stolen, Megan; Durden, Wendy Noke; McFee, Wayne; Bossart, Gregory D; Fair, Patricia A

2011-03-01

The significance of metal concentrations in marine mammals is not well understood and relating concentrations between stranded and free-ranging populations has been difficult. In order to predict liver concentrations in free-ranging dolphins, we examined concentrations of trace elements (Al, As, Ba, Be, Cd, Co, Cu, Fe, Li, Mn, Ni, Pb, Sb, Se, Sn, total Hg (THg), V, Zn) in skin and liver of stranded bottlenose dolphins (Tursiops truncatus) from the South Carolina (SC) coast and the Indian River Lagoon, Florida (FL) during 2000-2008. Significantly higher concentrations of Zn, Fe, Se, Al, Cu and THg were found in skin while liver exhibited significantly higher Cu, Fe, Mn and THg concentrations for both study sites. Mean skin concentrations of Cu and Mn were significantly higher in SC dolphins while higher concentrations of THg and V were found in FL dolphins. In addition, liver tissues in SC dolphins exhibited significantly higher As concentrations while higher Fe, Pb, Se, THg, and V levels were found in FL dolphins. Two elements (Cu and THg) showed significant age-related correlations with skin concentration while five elements (Cu, Se, THg, Zn and V) showed age-related correlations with liver concentrations. Geographic location influenced age-related accumulation of several trace elements and age-related accumulation of THg in hepatic tissue was observed for both sites to have the highest correlations (r² = 0.90SC; r² = 0.69FL). Mean THg concentration in liver was about 10 times higher in FL dolphins (330 μg g⁻¹ dw) than those samples from SC dolphins (34.3 μg g⁻¹ dw). The mean molar ratio of Hg to Se was 0.93 ± 0.32 and 1.08 ± 0.38 for SC and FL dolphins, respectively. However, the Hg:Se ratio varied with age as much lower ratios (0.2-0.4) were found in younger animals. Of the 18 measured elements, only THg was significantly correlated in skin and liver of stranded dolphins and skin of free-ranging dolphins from both sites suggesting that skin may be useful in predicting Hg concentrations in liver tissue of free-ranging dolphins. Results indicate that 33% of the stranded and 15% of the free-ranging dolphins from FL exceed the minimum 100 μg g⁻¹ wet weight (ww) (~ 400 dw) Hg threshold for hepatic damage while none from SC reached this level. Hepatic concentrations of As in SC dolphins and V in FL dolphins were also highly correlated with skin concentrations which may have some regional specificity predictive value. The present study provides the first application of trace element concentrations derived from stranded bottlenose dolphins to predict liver concentrations in free-ranging populations. Copyright © 2010. Published by Elsevier Ltd.

Sensitivity of Cirrus Properties to Ice Nuclei Abundance

NASA Technical Reports Server (NTRS)

Jensen, Eric

2014-01-01

The relative importance of heterogeneous and homogeneous ice nucleation for cirrus formation remains an active area of debate in the cloud physics community. From a theoretical perspective, a number of modeling studies have investigated the sensitivity of ice number concentration to the nucleation mechanism and the abundance of ice nuclei. However, these studies typically only addressed ice concentration immediately after ice nucleation. Recent modeling work has shown that the high ice concentrations produced by homogeneous freezing may not persist very long, which is consistent with the low frequency of occurrence of high ice concentrations indicated by cirrus measurements. Here, I use idealized simulations to investigate the impact of ice nucleation mechanism and ice nuclei abundance on the full lifecycle of cirrus clouds. The primary modeling framework used includes different modes of ice nucleation, deposition growth/sublimation, aggregation, sedimentation, and radiation. A limited number of cloud-resolving simulations that treat radiation/dynamics interactions will also been presented. I will show that for typical synoptic situations with mesoscale waves present, the time-averaged cirrus ice crystal size distributions and bulk cloud properties are less sensitive to ice nucleation processes than might be expected from the earlier simple ice nucleation calculations. I will evaluate the magnitude of the ice nuclei impact on cirrus for a range of temperatures and mesoscale wave specifications, and I will discuss the implications for cirrus aerosol indirect effects in general.

Pretreatment of industrial wastewater containing phthalate esters by centrifugation

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

Petrosky, C.J.; Vidic, R.D.

1996-11-01

In this study, a full-scale commercial centrifuge was used to treat, on a continuous basis, the entire wastewater stream generated by a chemical manufacturing facility which produces a variety of phthalate, adipate, maleate, and trimellitate esters. The wastewater from this facility is comprised of process water, equipment was water, and rain water runoff containing varying concentrations of bis(2-ethylhexyl) phthalate (BEHP), di-n-octyl phthalate (DNOP), and di-n-butyl phthalate (DNBP) esters in addition to mono-ester salts and alcohols. The wastewater is discharged to the local Publicly Owned Treatment Works (POTW) under pretreatment regulations which specify an effluent limitation of 5.0 mg/L on themore » total toxic organic (TTO) concentration which can be placed on the combined BEHP, DNOP, and DNBP ester concentration. Various esters and long chain alcohols present in the wastewater have very low water solubilities and are considered immiscible. They form a dispersed phase in the wastewater that has a specific gravity in the range of 0.88 to 0.93. Separation of the dispersed phase containing the regulated esters from the heavier water phase to consistently below 5.0 mg/L poses a challenge due to the stability of this colloidal suspension. The objective of this study was to evaluate the effectiveness of centrifugation in meeting the 5.0 mg/L effluent limit on the total BEHP, DNOP, and DNBP ester concentration.« less

Intermediates of peroxisomal beta-oxidation. A study of the fatty acyl-CoA esters which accumulate during peroxisomal beta-oxidation of [U-14C]hexadecanoate.

PubMed Central

Bartlett, K; Hovik, R; Eaton, S; Watmough, N J; Osmundsen, H

1990-01-01

1. 14C-labelled fatty acyl-CoA esters resulting from beta-oxidation of [U-14C]hexadecanoate by peroxisomal fractions isolated from rats treated with clofibrate showed the presence of the full range of saturated intermediates down to acetyl-CoA. 2. The pattern of intermediates generated was fairly constant. At low concentrations of [U-14C]hexadecanoate (50 microM), decanoyl-CoA was present in lowest amounts. At higher concentrations of [U-14C]hexadecanoate (greater than 100 microM), all intermediates of chain length shorter than 12 carbon atoms (except acetyl-CoA) were present at similar low concentrations; the process of beta-oxidation now resembling chain-shortening of hexadecanoate by two cycles of beta-oxidation. 3. In the absence of an NAD(+)-regenerating system [pyruvate and lactate dehydrogenase (EC 1.1.1.28)] 2-enoyl- and 3-hydroxyacyl-CoA esters were generated, suggesting that re-oxidation of NADH is essential for optimal rates of peroxisomal beta-oxidation in vitro. 4. At high concentrations of [U-14C]hexadecanoate (greater than 100 microM), 3-oxohexadecanoyl-CoA was produced, suggesting that thiolase (acetyl-CoA acetyltransferase; EC 2.3.1.9) can become rate-limiting for peroxisomal beta-oxidation. Images Fig. 2. Fig. 3. Fig. 4. PMID:2396977

River-induced flow dynamics in long-screen wells and impact on aqueous samples.

PubMed

Vermeul, Vince R; McKinley, James P; Newcomer, Darrell R; Mackley, Robert D; Zachara, J M

2011-01-01

Previously published field investigations and modeling studies have demonstrated the potential for sample bias associated with vertical wellbore flow in conventional monitoring wells constructed with long-screened intervals. This article builds on the existing body of literature by (1) demonstrating the utility of continuous (i.e., hourly measurements for ∼1 month) ambient wellbore flow monitoring and (2) presenting results from a field experiment where relatively large wellbore flows (up to 4 L/min) were induced by aquifer hydrodynamics associated with a fluctuating river boundary located approximately 250 m from the test well. The observed vertical wellbore flows were strongly correlated with fluctuations in river stage, alternating between upward and downward flow throughout the monitoring period in response to changes in river stage. Continuous monitoring of ambient wellbore flows using an electromagnetic borehole flowmeter allowed these effects to be evaluated in concert with continuously monitored river-stage elevations (hourly) and aqueous uranium concentrations (daily) in a long-screen well and an adjacent multilevel well cluster. This study demonstrates that when contaminant concentrations within the aquifer vary significantly over the depth interval interrogated, river-induced vertical wellbore flow can result in variations in measured concentration that nearly encompass the full range of variation in aquifer contaminant concentration with depth. Copyright © 2010 Battelle Memorial Institute. Journal compilation © 2010 National Ground Water Association.

Analytical modeling and experimental characterization of chemotaxis in Serratia marcescens

NASA Astrophysics Data System (ADS)

Zhuang, Jiang; Wei, Guopeng; Wright Carlsen, Rika; Edwards, Matthew R.; Marculescu, Radu; Bogdan, Paul; Sitti, Metin

2014-05-01

This paper presents a modeling and experimental framework to characterize the chemotaxis of Serratia marcescens (S. marcescens) relying on two-dimensional and three-dimensional tracking of individual bacteria. Previous studies mainly characterized bacterial chemotaxis based on population density analysis. Instead, this study focuses on single-cell tracking and measuring the chemotactic drift velocity VC from the biased tumble rate of individual bacteria on exposure to a concentration gradient of l-aspartate. The chemotactic response of S. marcescens is quantified over a range of concentration gradients (10-3 to 5 mM/mm) and average concentrations (0.5×10-3 to 2.5 mM). Through the analysis of a large number of bacterial swimming trajectories, the tumble rate is found to have a significant bias with respect to the swimming direction. We also verify the relative gradient sensing mechanism in the chemotaxis of S. marcescens by measuring the change of VC with the average concentration and the gradient. The applied full pathway model with fitted parameters matches the experimental data. Finally, we show that our measurements based on individual bacteria lead to the determination of the motility coefficient μ (7.25×10-6 cm2/s) of a population. The experimental characterization and simulation results for the chemotaxis of this bacterial species contribute towards using S. marcescens in chemically controlled biohybrid systems.

Tritium Separation from High Volume Dilute Aqueous Streams- Milestone Report for M3FT-15OR0302092

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

Bhave, Ramesh R.; Jubin, Robert Thomas; Spencer, Barry B.

2016-02-29

This report describes the synthesis and evaluation of molecular sieve zeolite membranes to separate and concentrate tritiated water (HTO) from dilute HTO-bearing aqueous streams. Several silico alumino phosphate (SAPO-34) molecular sieve zeolite membranes were synthesized and characterized with gas and vapor permeation measurements. The pervaporation process performance was evaluated for the separation and concentration of tritiated water. Experiments were performed over a range of tritiated water concentration covering the range of concentration anticipated in nuclear fuel processing where potentially both acid and water streams are recycled. The permeate was recovered under vacuum. The tritium concentration ranged from 0.5 to 1more » mCi/mL which is about 0.1 mg/L or 0.1 ppm. The HTO concentration was three orders of magnitude lower than experiments performed with simulated feed containing HDO (>100 ppm) using deuterated water where high separation factors (>10) were obtained using SAPO membranes. Separation factor calculated from the measured tritium concentrations ranged from 0.83-0.98. Although the membrane performance characterization results were lower than expected, they can be explained on the basis of low feed volume and three orders of magnitude lower HTO concentration compared to HDO concentration in deuterated water. We have identified several new approaches, such as tuning the diffusion coefficient of HTO, that may help achieve preferential transport of tritium (HTO) resulting in a substantially more concentrated permeate.« less

Measurement of late-night salivary cortisol with an automated immunoassay system.

PubMed

Vogeser, Michael; Durner, Jürgen; Seliger, Ewald; Auernhammer, Christoph

2006-01-01

Measurement of late-night salivary cortisol concentrations is increasingly used as a screening test in suspected Cushing's syndrome. Cortisol concentrations are typically extremely low in late-night samples and discordant assay-specific reference ranges have been reported. Therefore, the aim of our study was to assess the analytical performance of the first automated cortisol immunoassay specified for salivary measurements and to establish late-night sampling reference-range data for this test. Salivary cortisol was measured using the Roche Cobas Cortisol assay (Roche Diagnostics). Five salivary pools in different concentration ranges were used to assess the inter-assay imprecision of this test in a two-centre evaluation protocol including two reagent lots. Linearity was tested by serial dilution. Salivary samples were obtained at 23:00 h from 100 apparently healthy volunteers using a commercially available salivary sampling device (Salivette, Sarstedt). A subset of 20 samples was used for method comparison with isotope dilution liquid chromatography-tandem mass spectrometry. Inter-assay coefficients of variation (n=20) between 11.6% and 40.4% were found for mean cortisol concentrations between 12.9 and 2.6 nmol/L, with an estimated functional sensitivity of approximately 5.0 nmol/L. The test also gave linear results in the lowest concentration range between 1.0 and 8.3 nmol/L. Mean late-night salivary cortisol of 5.0 nmol/L was found for healthy individuals; the absolute range was 1.4-16.7 nmol/L, and the 95th percentile was 8.9 nmol/L. Substantially lower concentrations were found with isotope dilution LC-MS/MS compared to immunoassay results (mean concentrations 1.8 and 4.4 nmol/L, respectively). The automated assay investigated was found to offer acceptable analytical performance in the very low concentration range required for late-night salivary cortisol, despite a very short turn-around time. Using this assay, late-night salivary cortisol concentrations below 8.9 nmol/L are typically found in healthy volunteers.

Evaluation of Water-Chemistry and Water-Level Data at the Henderson Road Superfund Site, Upper Merion Township, Montgomery County, Pennsylvania, 1991-2008

USGS Publications Warehouse

Sloto, Ronald A.

2009-01-01

Several shutdown-rebound tests have been conducted at the Henderson Road Superfund Site, which has been on the U.S. Environmental Protection Agency's National Priorities List since 1984. For a given test, the extraction wells are turned off, and water samples are collected from selected monitor wells at regular intervals before and during cessation of pumping to monitor for changes in chemical concentrations. A long-term shutdown-rebound test began on July 17, 2006. In support of this test, the U.S. Geological Survey conducted this study to determine the effects of shutting down on-site extraction wells on concentrations of selected contaminants and water levels. Concentrations were compared to ARARs (applicable relevant and appropriate requirements), which were set as remediation goals in the Henderson Road Site Record of Decision. Water from 10 wells in and near the source area and to the north, northeast, and northwest of the source area sampled in 2008 exceeded the 5.52 ug/L (micrograms per liter) ARAR for benzene. The greatest changes in benzene concentration between pre-shutdown samples collected in July 2006 and samples collected in February and March 2008 (19 months after the shutdown) were for wells in and north of the source area; increases in benzene concentration ranged from 1.5 to 164 ug/L. Water from five wells in the source area and to the north and northwest of the source area sampled in 2008 exceeded the 60 ug/L ARAR for chlorobenzene. The greatest changes in chlorobenzene concentration between pre-shutdown samples collected in July 2006 and samples collected in February and March 2008 were for wells north of the source area; increases in chlorobenzene concentration ranged from 6.9 to 99 ug/L. The highest concentrations of chlorobenzene were near or outside the northern site boundary, indicating chlorobenzene may have moved north away from the source area; however, no monitor well clusters are on the northern side of the Pennsylvania Turnpike, which is about 190 feet north of the source area. A much larger area was affected by chlorobenzene than benzene. Chlorobenzene concentrations decreased in the source area and increased at and beyond the site boundary. Water from four wells in and northeast of the source area sampled in 2008 exceeded the 5.06 ug/L ARAR for 1,1-dichloroethane (1,1-DCA). Increases in 1,1-DCA concentration between pre-shutdown samples collected in July 2006 and samples collected in February 2008 ranged from 0.4 to 20 ug/L. Water from two wells in the source area sampled in 2008 exceeded the 175 ug/L ARAR for total xylene. The 1,1-DCA and xylene plumes appear to extend in an east-northeast direction from the source area. Large drawdowns in the Upper Merion Reservoir during droughts in 1998 and 2001 affected water levels in the Chester Valley and at the Henderson Road Site, except for well HR-17-170. After the drought of 2001, water levels in the Chester Valley showed a protracted recovery lasting from September 2001 until June 2005 (46 months). Water-level data were evaluated temporally for 1997-2008 and spatially for (1) June 16, 2003, when the extraction wells were pumping at the full rate prior to the start of the June 2003 shutdown test; (2) July 10, 2006, during the period of reduced pumping after the June 2003 shutdown test; and (3) February 25-29, 2008, when the extraction wells were not pumping. Except for well HR-5-195, wells were categorized as shallow, intermediate-depth, and deep wells. The potentiometric surface for shallow wells did not appear to be affected by pumping of the extraction wells. The general direction of ground-water flow was to the north. The potentiometric surface for intermediate-depth wells showed a cone of depression when the extraction wells were pumping at the full rate but did not show a cone of depression when the extraction wells were pumping at the reduced rate. The ground-water-flow direction was toward the north and northeast, similar to

Highly Concentrated Nebular Noble Gases in Porous Nanocarbon Separates from the Saratov (L4) Meteorite

NASA Astrophysics Data System (ADS)

Amari, Sachiko; Matsuda, Jun-ichi; Stroud, Rhonda M.; Chisholm, Matthew F.

2013-11-01

The majority of heavy noble gases (Ar, Kr, and Xe) in primitive meteorites are stored in a poorly understood phase called Q. Although Q is thought to be carbonaceous, the full identity of the phase has remained elusive for almost four decades. In order to better characterize phase Q and, in turn, the early solar nebula, we separated carbon-rich fractions from the Saratov (L4) meteorite. We chose this meteorite because Q is most resistant in thermal alteration among carbonaceous noble gas carriers in meteorites and we hoped that, in this highly metamorphosed meteorite, Q would be present but not diamond: these two phases are very difficult to separate from each other. One of the fractions, AJ, has the highest 132Xe concentration of 2.1 × 10-6 cm3 STP g-1, exceeding any Q-rich fractions that have yet been analyzed. Transmission electron microscopy studies of the fraction AJ and a less Q-rich fraction AI indicate that they both are primarily porous carbon that consists of domains with short-range graphene orders, with variable packing in three dimensions, but no long-range graphitic order. The relative abundance of Xe and C atoms (6:109) in the separates indicates that individual noble gas atoms are associated with only a minor component of the porous carbon, possibly one or more specific arrangements of the nanoparticulate graphene.

Is there a risk associated with the insect repellent DEET (N,N-diethyl-m-toluamide) commonly found in aquatic environments?

USGS Publications Warehouse

Costanzo, S.D.; Watkinson, A.J.; Murby, E.J.; Kolpin, D.W.; Sandstrom, M.W.

2007-01-01

DEET (N,N-diethyl-m-toluamide) is the active ingredient of most commercial insect repellents. This compound has commonly been detected in aquatic water samples from around the world indicating that DEET is both mobile and persistent, despite earlier assumptions that DEET was unlikely to enter aquatic ecosystems. DEET's registration category does not require an ecological risk assessment, thus information on the ecological toxicity of DEET is sparse. This paper reviews the presence of DEET in aqueous samples from around the world (e.g. drinking water, streams, open seawater, groundwater and treated effluent) with reported DEET concentrations ranging from 40–3000 ng L− 1. In addition, new DEET data collected from 36 sites in coastal waterways from eastern Australia (detections ranging from 8 to 1500 ng L− 1) are examined. A summary of new and existing toxicity data are discussed with an emphasis on preparing a preliminary risk assessment for DEET in the aquatic environment. Collated information on DEET in the aquatic environment suggests risk to aquatic biota at observed environmental concentrations is minimal. However, the information available was not sufficient to conduct a full risk assessment due to data deficiencies in source characterisation, transport mechanisms, fate, and ecotoxicity studies. These risks warrant further investigation due to the high frequency that this organic contaminant is detected in aquatic environments around the world.

Removal of odor emitted from composting facilities using a porous ceramic biofilter.

PubMed

Park, S J; Nam, S L; Choi, E S

2001-01-01

A field experiment was conducted using a full-scale ceramic biofilter (approximately 150 m3/min) in order to determine the potential for biofiltration to remove malodorous gases from composting facilities. The main compounds found in malodorous gases were NH3 and H2S. These compounds were analyzed by a UV-spectrophotometer and gas chromatograph. The microbial carrier was a porous ceramic consisting of diatomite and fly ash. About 12 m3 of ceramic media inoculated with waste activated sludge were filled in the biofilter. The experimental conditions were space velocity of 500 hr(-1), empty bed residence time of 7.2 s, and linear velocity of 0.2 m/s. About 90 L/d of water were sprayed for the operation. The NH3 concentration in inlet gases ranged from 8 to 90 ppmv. The concentration of H2S ranged from 3.2-5.5 ppmv. The acclimation of the biofilter was slow, but more than 95% of removal efficiency was achieved after one month of operation. No nutrients were supplied to the biofilter. The pressure drop in the biofilter varied from 20-40 mmAq during the operation. The energy consumption of this biofilter was about 200 kW/d. It was estimated that the deodorization using this ceramic biofilter was successfully carried out to remove the odor emitted from composting facilities.

Dark respiration rate increases with plant size in saplings of three temperate tree species despite decreasing tissue nitrogen and nonstructural carbohydrates.

PubMed

Machado, José-Luis; Reich, Peter B

2006-07-01

In shaded environments, minimizing dark respiration during growth could be an important aspect of maintaining a positive whole-plant net carbon balance. Changes with plant size in both biomass distribution to different tissue types and mass-specific respiration rates (R(d)) of those tissues would have an impact on whole-plant respiration. In this paper, we evaluated size-related variation in R(d), biomass distribution, and nitrogen (N) and total nonstructural carbohydrate (TNC) concentrations of leaves, stems and roots of three cold-temperate tree species (Abies balsamea (L.) Mill, Acer rubrum L. and Pinus strobus L.) in a forest understory. We sampled individuals varying in age (6 to 24 years old) and in size (from 2 to 500 g dry mass), and growing across a range of irradiances (from 1 to 13% of full sun) in northern Minnesota, USA. Within each species, we found small changes in R(d), N and TNC when comparing plants growing across this range of light availability. Consistent with our hypotheses, as plants grew larger, whole-plant N and TNC concentrations in all species declined as a result of a combination of changes in tissue N and shifts in biomass distribution patterns. However, contrary to our hypotheses, whole-plant and tissue R(d) increased with plant size in the three species.

Development of an embryo toxicity test with the pond snail Lymnaea stagnalis using the model substance tributyltin and common solvents.

PubMed

Bandow, Cornelia; Weltje, Lennart

2012-10-01

The development of a chronic mollusc toxicity test is a current work item on the agenda of the OECD. The freshwater pond snail Lymnaea stagnalis is one of the candidate snail species for such a test. This paper presents a 21-day chronic toxicity test with L. stagnalis, focussing on embryonic development. Eggs were collected from freshly laid egg masses and exposed individually until hatching. The endpoints were hatching success and mean hatching time. Tributyltin (TBT), added as TBT-chloride, was chosen as model substance. The selected exposure concentrations ranged from 0.03 to 10 μg TBT/L (all as nominal values) and induced the full range of responses. The embryos were sensitive to TBT (the NOEC for mean hatching time was 0.03 μg TBT/L and the NOEC for hatching success was 0.1 μg TBT/L). In addition, data on maximum limit concentrations of seven common solvents, recommended in OECD aquatic toxicity testing guidelines, are presented. Among the results, further findings as average embryonic growth and mean hatching time of control groups are provided. In conclusion, the test presented here could easily be standardised and is considered useful as a potential trigger to judge if further studies, e.g. a (partial) life-cycle study with molluscs, should be conducted. Copyright © 2012 Elsevier B.V. All rights reserved.

A full-Bayesian approach to parameter inference from tracer travel time moments and investigation of scale effects at the Cape Cod experimental site

USGS Publications Warehouse

Woodbury, Allan D.; Rubin, Yoram

2000-01-01

A method for inverting the travel time moments of solutes in heterogeneous aquifers is presented and is based on peak concentration arrival times as measured at various samplers in an aquifer. The approach combines a Lagrangian [Rubin and Dagan, 1992] solute transport framework with full‐Bayesian hydrogeological parameter inference. In the full‐Bayesian approach the noise values in the observed data are treated as hyperparameters, and their effects are removed by marginalization. The prior probability density functions (pdfs) for the model parameters (horizontal integral scale, velocity, and log K variance) and noise values are represented by prior pdfs developed from minimum relative entropy considerations. Analysis of the Cape Cod (Massachusetts) field experiment is presented. Inverse results for the hydraulic parameters indicate an expected value for the velocity, variance of log hydraulic conductivity, and horizontal integral scale of 0.42 m/d, 0.26, and 3.0 m, respectively. While these results are consistent with various direct‐field determinations, the importance of the findings is in the reduction of confidence range about the various expected values. On selected control planes we compare observed travel time frequency histograms with the theoretical pdf, conditioned on the observed travel time moments. We observe a positive skew in the travel time pdf which tends to decrease as the travel time distance grows. We also test the hypothesis that there is no scale dependence of the integral scale λ with the scale of the experiment at Cape Cod. We adopt two strategies. The first strategy is to use subsets of the full data set and then to see if the resulting parameter fits are different as we use different data from control planes at expanding distances from the source. The second approach is from the viewpoint of entropy concentration. No increase in integral scale with distance is inferred from either approach over the range of the Cape Cod tracer experiment.

Influence of partial activation on force-velocity properties of frog skinned muscle fibers in millimolar magnesium ion

PubMed Central

1986-01-01

Segments of briefly glycerinated muscle fibers from Rana pipiens were activated rapidly by a brief exposure to 2.5 mM free calcium followed by a solution containing calcium buffered with EGTA to produce the desired level of force. Steps to isotonic loads were made using a servomotor, usually 3-5 s after the onset of activation. The relative isotonic forces (P/P0) and velocities from contractions obtained under similar circumstances were grouped together and fitted with hyperbolic functions. Under the condition of 6 mM MgCl2 and 5 mM ATP, there was no significant difference in the relative force-velocity relations obtained at full activation compared with those obtained at partial activation when developed force was approximately 40% of its full value. Control experiments showed that a variety of factors did not alter either the relative force-velocity relations or the finding that partial activation did not change these properties. The factors investigated included the decline in force that occurs with each successive contraction of skinned fibers, the segment length (over a range of 1-3 mm), the sarcomere length (over a range of 1.9-2.2 microns), the magnesium ion concentration (26 microM and 1.4 mM were tested), the ATP concentration, the presence of free calcium, and the age of the preparation (up to 30 h). Attempts to repeat earlier experiments by others showing a dependence of shortening velocity on activation were unsuccessful because the low ionic strength used in those experiments caused the fibers to break after a few contractions. The main conclusion, that the shortening velocity is independent of the level of activation, is consistent with the hypothesis that the cross- bridges act independently and that activating calcium acts only as an all-or-none switch for individual cross-bridge attachment sites, and does not otherwise influence the kinetics of cross-bridge movement. PMID:3486252

Exposure assessment in Beijing, China: biological agents, ultrafine particles, and lead.

PubMed

Dong, Shuofei; Yao, Maosheng

2010-11-01

In this study, air samples were taken using a BioSampler and gelatin filters from six sites in Beijing: office, hospital, student dormitory, train station, subway, and a commercial street. Dust samples were also collected using a surface sampler from the same environments. Limulus amoebocyte lysate (LAL) and Glucatell assays were used to quantify sample endotoxin and (1,3)-β-d-glucan concentration levels, respectively. Enzyme-linked immunosorbent assay (ELISA) was used to measure the dust mite allergens (Der p 1 and Der f 1). Ultrafine particle and lead concentrations in these sampling sites were also measured using P-Trak and atomic absorption spectrometer, respectively. Analysis of variance (ANOVA) and linear regression analysis were used to analyze the concentration data. Higher culturable bacteria (12,639 CFU/m3) and fungi (1,806 CFU/m3) concentrations were observed for the train station and the subway system, respectively. For the rest of sampling sites, their concentrations were comparable to those found in western countries, ranging from 990 to 2,276 CFU/m3 for bacteria, and from 119 to 269 CFU/m3 for fungi. ANOVA analysis indicated that there were statistically significant differences between the culturable bacterial and fungal concentration levels obtained for different sites (p value=0.0001 and 0.0047). As for dust allergens, endotoxin, and (1,3)-β-D-glucan, their concentrations also seemed to be comparable to those found in the developed countries. Airborne allergen concentrations ranged from 16 to 68 ng/m3. The dust-borne allergen concentration was observed to range from 0.063 to 0.327 ng/mg. As for endotoxin, the highest airborne concentration of 25.24 ng/m3 was observed for the commercial street, and others ranged from 0.0427 to 0.1259 ng/m3. And dust-borne endotoxin concentration ranged from 58.83 to 6,427.4 ng/mg. For (1,3)-β-D-glucan, the airborne concentration ranged from 0.02 to 1.2 ng/m3. Linear regression analyses showed that there existed poor correlations between those in airborne and dust-borne states (R2=0.002~0.43). In our study, the lowest ultrafine particle concentration about 5,203 pt/cm3 was observed in office and the highest was observed at the train station, up to 32,783 pt/cm3. Lead concentration was shown to range from 80 to 170 ng/mg with the highest also observed at the train station. The information provided in this work can be used to learn the general situation of relevant health risks in Beijing. And the results here suggested that when characterizing exposure both airborne and dust-borne as well as the environments should be considered.

Effect of parvoviral enteritis on plasma citrulline concentration in dogs.

PubMed

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

2011-01-01

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

Vacancy–Vacancy Interaction Induced Oxygen Diffusivity Enhancement in Undoped Nonstoichiometric Ceria

DOE PAGES

Yuan, Fenglin; Zhang, Yanwen; Weber, William J.

2015-05-19

In this paper, molecular dynamics simulations and molecular static calculations have been used to systematically study oxygen vacancy transport in undoped nonstoichiometric ceria. A strong oxygen diffusivity enhancement appears in the vacancy concentration range of 2–4% over the temperature range from 1000 to 2000 K. An Arrhenius ion diffusion mechanism by vacancy hopping along the (100) direction is unambiguously identified, and an increasing trend of both the oxygen migration barrier and the prefactor with increasing vacancy concentration is observed. Within the framework of classical diffusion theory, a weak concentration dependence of the prefactor in oxygen vacancy migration is shown tomore » be crucial for explaining the unusual fast oxygen ion migration in the low concentration range and consequently the appearance of a maximum in oxygen diffusivity. Finally, a representative (100) direction interaction model is constructed to identify long-range vacancy–vacancy interaction as the structural origin of the positive correlation between oxygen migration barrier and vacancy concentration.« less

Muscle activity during knee-extension strengthening exercise performed with elastic tubing and isotonic resistance.

PubMed

Jakobsen, Markus Due; Sundstrup, Emil; Andersen, Christoffer H; Bandholm, Thomas; Thorborg, Kristian; Zebis, Mette K; Andersen, Lars L

2012-12-01

While elastic resistance training, targeting the upper body is effective for strength training, the effect of elastic resistance training on lower body muscle activity remains questionable. The purpose of this study was to evaluate the EMG-angle relationship of the quadriceps muscle during 10-RM knee-extensions performed with elastic tubing and an isotonic strength training machine. 7 women and 9 men aged 28-67 years (mean age 44 and 41 years, respectively) participated. Electromyographic (EMG) activity was recorded in 10 muscles during the concentric and eccentric contraction phase of a knee extension exercise performed with elastic tubing and in training machine and normalized to maximal voluntary isometric contraction (MVC) EMG (nEMG). Knee joint angle was measured during the exercises using electronic inclinometers (range of motion 0-90°). When comparing the machine and elastic resistance exercises there were no significant differences in peak EMG of the rectus femoris (RF), vastus lateralis (VL), vastus medialis (VM) during the concentric contraction phase. However, during the eccentric phase, peak EMG was significantly higher (p<0.01) in RF and VM when performing knee extensions using the training machine. In VL and VM the EMG-angle pattern was different between the two training modalities (significant angle by exercise interaction). When using elastic resistance, the EMG-angle pattern peaked towards full knee extension (0°), whereas angle at peak EMG occurred closer to knee flexion position (90°) during the machine exercise. Perceived loading (Borg CR10) was similar during knee extensions performed with elastic tubing (5.7±0.6) compared with knee extensions performed in training machine (5.9±0.5). Knee extensions performed with elastic tubing induces similar high (>70% nEMG) quadriceps muscle activity during the concentric contraction phase, but slightly lower during the eccentric contraction phase, as knee extensions performed using an isotonic training machine. During the concentric contraction phase the two different conditions displayed reciprocal EMG-angle patterns during the range of motion. 5.

Nitrate consumption in sediments of the German Bight (North Sea)

NASA Astrophysics Data System (ADS)

Neumann, Andreas; van Beusekom, Justus E. E.; Holtappels, Moritz; Emeis, Kay-Christian

2017-09-01

Denitrification on continental margins and in coastal sediments is a major sink of reactive N in the present nitrogen cycle and a major ecosystem service of eutrophied coastal waters. We analyzed the nitrate removal in surface sediments of the Elbe estuary, Wadden Sea, and adjacent German Bight (SE North Sea) during two seasons (spring and summer) along a eutrophication gradient ranging from a high riverine nitrate concentrations at the Elbe Estuary to offshore areas with low nitrate concentrations. The gradient encompassed the full range of sediment types and organic carbon concentrations of the southern North Sea. Based on nitrate penetration depth and concentration gradient in the porewater we estimated benthic nitrate consumption rates assuming either diffusive transport in cohesive sediments or advective transport in permeable sediments. For the latter we derived a mechanistic model of porewater flow. During the peak nitrate discharge of the river Elbe in March, the highest rates of diffusive nitrate uptake were observed in muddy sediments (up to 2.8 mmol m- 2 d- 1). The highest advective uptake rate in that period was observed in permeable sediment and was tenfold higher (up to 32 mmol m- 2 d- 1). The intensity of both diffusive and advective nitrate consumption dropped with the nitrate availability and thus decreased from the Elbe estuary towards offshore stations, and were further decreased during late summer (minimum nitrate discharge) compared to late winter (maximum nitrate discharge). In summary, our rate measurements indicate that the permeable sediment accounts for up to 90% of the total benthic reactive nitrogen consumption in the study area due to the high efficiency of advective nitrate transport into permeable sediment. Extrapolating the averaged nitrate consumption of different sediment classes to the areas of Elbe Estuary, Wadden Sea and eastern German Bight amounts to an N-loss of 3.1 ∗ 106 mol N d- 1 from impermeable, diffusion-controlled sediment, and 5.2 ∗ 107 mol N d- 1 from permeable sediment with porewater advection.

Hydrogeochemical and stream sediment reconnaissance basic data report for Williams NTMS quadrangle, Arizona

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

Wagoner, J.L.

Wet and dry sediments were collected throughout the 18,500-km/sup 2/arid-to-semiarid region and water samples at available streams, springs, and wells. Samples were collected between August 1977 and January 1978. Results of neutron activation analyses of uranium and trace elements and other field and laboratory analyses are presented in tabular hardcopy and microfiche format. The report includes six full-size overlays for use with the Williams NTMS 1:250,000 quadrangle. Sediment samples are divided into five general groups according to the source rock from which the sediment was derived. Background uranium concentrations for the quadrangle are relatively low, ranging from 1.91 to 2.40more » ppM, with the highest associated with the Precambrian igneous and metamorphic complexes of the Basin and Range province. Uranium correlates best with the rare-earth elements and iron, scandium, titanium, and manganese. Known uranium occurrences are not readily identified by the stream sediment data.« less

Lunar Meteoroid Impact Observations and the Flux of Kilogram-Size Meteoroids

NASA Technical Reports Server (NTRS)

Suggs, Rob; Cooke, Bill; Koehler, Heather; Moser, Danielle; Suggs, Ron; Swift, Wes

2010-01-01

Meteor showers dominate the environment in this size range and explain the evening/morning flux asymmetry of 1.5:1. With sufficient numbers of impacts, this technique can help determine the population index for some showers. Measured flux of meteoroids in the 100g to kilograms range is consistent with other observations. We have a fruitful observing program underway which has significantly increased the number of lunar impacts observed. Over 200 impacts have been recorded in about 4 years. This analysis reports on the 115 impacts taken under photometric conditions during the first 3 full years of operation. We plan to continue for the foreseeable future as follows: 1) Run detailed model to try explain the concentration near the trailing limb; 2) Build up statistics to better understand the meteor shower environment; 3) Provide support for robotic seismometers and dust missions; and 4) Deploy near-infrared and visible cameras with dichroic beamsplitter to 0.5m telescope in New Mexico.

Biofiltration: An innovative air pollution control technology for VOC emissions

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

Leson, G.; Winer, A.M.

1991-08-01

Biofiltration is a relatively recent air pollution control (APC) technology in which off-gases containing biodegradable volatile organic compounds (VOC) or inorganic air toxics are vented through a biologically active material. This technology has been successfully applied in Germany and The Netherlands in many full-scale applications to control odors, VOC and air toxic emissions from a wide range of industrial and public sector sources. Control efficiencies of more than 90 percent have been achieved for many common air pollutants. Due to lower operating costs, biofiltration can provide significant economic advantages over other APC technologies if applied to off-gases that contain readilymore » biodegradable pollutants in low concentrations. Environmental benefits include low energy requirements and the avoidance of cross media transfer of pollutants. This paper reviews the history and current status of biofiltration, outlines its underlying scientific and engineering principles, and discusses the applicability of biofilters for a wide range of specific emission sources.« less

Modeling of the control of the driven current profile in ICRF MCCD on EAST plasma

NASA Astrophysics Data System (ADS)

Yin, L.; Yang, C.; Gong, X. Y.; Lu, X. Q.; Cao, J. J.; Wu, Z. Y.; Chen, Y.; Du, D.

2018-05-01

Control of the current profile is a crucial issue for improved confinement and the inhibition of instability in advanced tokamak operation. Using typical discharge data for the Experimental Advanced Superconducting Tokamak, numerical simulations of driven-current profile control in mode conversion current drive (MCCD) in the ion cyclotron range of frequencies were performed employing a full-wave method and Ehst-Karney efficiency formula. Results indicate that the driven current profile in MCCD can be effectively modified by shifting the mode conversion layer. The peak of the driven current can be located at an aimed position in the normalized minor radius range (-0.60 ≤r/a≤0) by changing the radiofrequency and the minority-ion concentration. The efficiency of the off-axis MCCD can reach 233 kA/MW through optimization, and the mode converted ion cyclotron wave plays an important role in such scenarios. The effects of electron temperature and plasma density on the driven current profile are also investigated.

Education, Technology, and Media: A Peak into My Summer Internship at NASA Glenn Research Center in Cleveland, Ohio

NASA Technical Reports Server (NTRS)

Moon, James

2004-01-01

My name is James Moon and I am a senor at Tennessee State University where my major is Aeronautical and Industrial Technology with a concentration in industrial electronics. I am currently serving my internship in the Engineering and Technical Services Directorate at the Glenn Research Center (GRC). The Engineering and Technical Service Directorate provides the services and infrastructure for the Glenn Research Center to take research concepts to reality. They provide a full range of integrated services including engineering, advanced prototyping and testing, facility management, and information technology for NASA, industry, and academia. Engineering and Technical Services contains the core knowledge in Information Technology (IT). This includes data systems and analysis, inter and intranet based systems design and data security. Including the design and development of embedded real-time sohare applications for flight and supporting ground systems, Engineering and Technical Services provide a wide range of IT services and products specific to the Glenn Research Center research and engineering community.

Different thresholds for detection and discrimination of odors in the honey bee (Apis mellifera).

PubMed

Wright, Geraldine A; Smith, Brian H

2004-02-01

Naturally occurring odors used by animals for mate recognition, food identification and other purposes must be detected at concentrations that vary across several orders of magnitude. Olfactory systems must therefore have the capacity to represent odors over a large range of concentrations regardless of dramatic changes in the salience, or perceived intensity, of a stimulus. The stability of the representation of an odor relative to other odors across concentration has not been extensively evaluated. We tested the ability of honey bees to discriminate pure odorants across a range of concentrations at and above their detection threshold. Our study showed that pure odorant compounds became progressively easier for honey bees to discriminate with increasing concentration. Discrimination is, therefore, a function of odorant concentration. We hypothesize that the recruitment of sensory cell populations across a range of concentrations may be important for odor coding, perhaps by changing its perceptual qualities or by increasing its salience against background stimuli, and that this mechanism is a general property of olfactory systems.

Darunavir concentrations in cerebrospinal fluid and blood in HIV-1-infected individuals.

PubMed

Yilmaz, Aylin; Izadkhashti, Arash; Price, Richard W; Mallon, Patrick W; De Meulder, Marc; Timmerman, Philip; Gisslén, Magnus

2009-04-01

Darunavir is the most recently licensed protease inhibitor currently used in treatment-experienced HIV-infected individuals. Our objective was to determine darunavir concentrations in cerebrospinal fluid (CSF) and plasma in subjects receiving antiretroviral treatment regimens containing ritonavir-boosted darunavir. Darunavir concentrations were determined by liquid chromatography tandem mass spectrometry in 14 paired CSF and plasma samples from eight HIV-1-infected individuals. The lower limit of quantification was 5.0 ng/ml. All of the 14 CSF samples had detectable darunavir concentrations with a median darunavir concentration of 34.2 ng/ml (range 15.9-212.0 ng/ml). The median (range) plasma darunavir concentration was 3930 (1800-12900) ng/ml. All CSF samples had detectable darunavir concentrations. Most of them exceeded or were in the same range as levels needed to inhibit replication of wild type virus, making it probable that darunavir, at least to some extent, contributes to the suppression of HIV replication in the central nervous system.

Environmental 238U and 232Th concentration measurements in an area of high level natural background radiation at Palong, Johor, Malaysia.

PubMed

Ramli, A Termizi; Hussein, A Wahab M A; Wood, A Khalik

2005-01-01

Concentrations of uranium-238 and thorium-232 in soil, water, grass, moss and oil-palm fruit samples collected from an area of high background radiation were determined using neutron activation analysis (NAA). U-238 concentration in soil ranged from 4.9 mg kg(-1) (58.8 Bq kg(-1)) to 40.4 mg kg(-1) (484.8 Bq kg(-1)), Th-232 concentration ranged from 14.9 mg kg(-1) (59.6 Bq kg(-1)) to 301.0 mg kg(-1) (1204 Bq kg(-1)). The concentration of U-238 in grass samples ranged from below the detection limit to 0.076 mg kg(-1) (912 mBq kg(-1)), and Th-232 ranged from 0.008 mg kg(-1) (32 mBq kg(-1)) to 0.343 mg kg(-1) (1.372 Bq kg(-1)). U-238 content in water samples ranged from 0.33 mg kg(-1) (4.0 Bq L(-1)) to 1.40 mg kg(-1) (16.8 Bq L(-1)), and Th-232 ranged from 0.19 mg kg(-1) (0.76 Bq L(-1)) to 0.66 mg kg(-1) (2.64 Bq L(-1)). It can be said that the concentrations of environmental U-238 and Th-232 in grass and water samples in the study area are insignificant. Mosses were found to be possible bio-radiological indicators due to their high absorption of the heavy radioelements from the environment.

Quantitative investigation of a novel small field of view hybrid gamma camera (HGC) capability for sentinel lymph node detection

PubMed Central

Lees, John E; Bugby, Sarah L; Jambi, Layal K; Perkins, Alan C

2016-01-01

Objective: The hybrid gamma camera (HGC) has been developed to enhance the localization of radiopharmaceutical uptake in targeted tissues during surgical procedures such as sentinel lymph node (SLN) biopsy. To assess the capability of the HGC, a lymph node contrast (LNC) phantom was constructed to simulate medical scenarios of varying radioactivity concentrations and SLN size. Methods: The phantom was constructed using two clear acrylic glass plates. The SLNs were simulated by circular wells of diameters ranging from 10 to 2.5 mm (16 wells in total) in 1 plate. The second plate contains four larger rectangular wells to simulate tissue background activity surrounding the SLNs. The activity used to simulate each SLN ranged between 4 and 0.025 MBq. The activity concentration ratio between the background and the activity injected in the SLNs was 1 : 10. The LNC phantom was placed at different depths of scattering material ranging between 5 and 40 mm. The collimator-to-source distance was 120 mm. Image acquisition times ranged from 60 to 240 s. Results: Contrast-to-noise ratio analysis and full-width-at-half-maximum (FWHM) measurements of the simulated SLNs were carried out for the images obtained. Over the range of activities used, the HGC detected between 87.5 and 100% of the SLNs through 20 mm of scattering material and 75–93.75% of the SLNs through 40 mm of scattering material. The FWHM of the detected SLNs ranged between 11.93 and 14.70 mm. Conclusion: The HGC is capable of detecting low accumulation of activity in small SLNs, indicating its usefulness as an intraoperative imaging system during surgical SLN procedures. Advances in knowledge: This study investigates the capability of a novel small-field-of-view (SFOV) HGC to detect low activity uptake in small SLNs. The phantom and procedure described are inexpensive and could be easily replicated and applied to any SFOV camera, to provide a comparison between systems with clinically relevant results. PMID:27537079

Optimal design of vertebrate and insect sarcomeres.

PubMed

Otten, E

1987-01-01

This paper offers a model for the normalized length-tension relation of a muscle fiber based upon sarcomere design. Comparison with measurements published by Gordon et al. ('66) shows an accurate fit as long as the inhomogeneity of sarcomere length in a single muscle fiber is taken into account. Sequential change of filament length and the length of the cross-bridge-free zone leads the model to suggest that most vertebrate sarcomeres tested match the condition of optimal construction for the output of mechanical energy over a full sarcomere contraction movement. Joint optimization of all three morphometric parameters suggests that a slightly better (0.3%) design is theoretically possible. However, this theoretical sarcomere, optimally designed for the conversion of energy, has a low normalized contraction velocity; it provides a poorer match to the combined functional demands of high energy output and high contraction velocity than the real sarcomeres of vertebrates. The sarcomeres in fish myotomes appear to be built suboptimally for isometric contraction, but built optimally for that shortening velocity generating maximum power. During swimming, these muscles do indeed contract concentrically only. The sarcomeres of insect asynchronous flight muscles contract only slightly. They are not built optimally for maximum output of energy across the full range of contraction encountered in vertebrate sarcomeres, but are built almost optimally for the contraction range that they do in fact employ.

[Relationship between the nitrogen removal and oxygen demand in constructed wetlands].

PubMed

He, Lian-sheng; Liu, Hong-liang; Xi, Bei-dou; Zhu, Ying-bo; Wei, Zi-min; Huo, Shou-liang

2006-06-01

A simplified model of sequential N transformations and sink was applied to investigate the relationship between the nitrogen removal and oxygen demand to verify the validity of full nitrification-denitrification mechanism in a newly-built multi-stages constructed wetlands. Average net rates of N mineralization ranged from 0.01 to 0.28 g x (m2 x d)(-1), nitrification from 0.50 to 1.54 g x (m2 x d)(-1), denitrification from 0.41 to 1.13 g x (m2 x d)(-1)(3.4% approximately 35.4% of measured N removal in different stage) and plant assimilation from 0.07 to 0.26 g x (m2 x d)(-1) in the five tanks. Nitrification and denitrification occurred concurrently with BOD removal, even in the first stage receiving the higher-strength wastewater. Surprisingly, net areal nitrification rates, was correlated with BOD removal rates positively. Nitrification rates were also correlated linearly with average NH4+-N concentrations in the cascade tanks. The nitrogenous oxygen demand (NOD) required to support full nitrification of ammonia and mineralized Org-N in the wetland was in the upper range of that expected to be able to be supplied through surface and plant-mediated oxygen transfer. Some potential alternative nitrogen removal pathways with reduced overall oxygen requirements that have relevance to constructed wetlands were discussed.

Green method by diffuse reflectance infrared spectroscopy and spectral region selection for the quantification of sulphamethoxazole and trimethoprim in pharmaceutical formulations.

PubMed

da Silva, Fabiana E B; Flores, Érico M M; Parisotto, Graciele; Müller, Edson I; Ferrão, Marco F

2016-03-01

An alternative method for the quantification of sulphametoxazole (SMZ) and trimethoprim (TMP) using diffuse reflectance infrared Fourier-transform spectroscopy (DRIFTS) and partial least square regression (PLS) was developed. Interval Partial Least Square (iPLS) and Synergy Partial Least Square (siPLS) were applied to select a spectral range that provided the lowest prediction error in comparison to the full-spectrum model. Fifteen commercial tablet formulations and forty-nine synthetic samples were used. The ranges of concentration considered were 400 to 900 mg g-1SMZ and 80 to 240 mg g-1 TMP. Spectral data were recorded between 600 and 4000 cm-1 with a 4 cm-1 resolution by Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS). The proposed procedure was compared to high performance liquid chromatography (HPLC). The results obtained from the root mean square error of prediction (RMSEP), during the validation of the models for samples of sulphamethoxazole (SMZ) and trimethoprim (TMP) using siPLS, demonstrate that this approach is a valid technique for use in quantitative analysis of pharmaceutical formulations. The selected interval algorithm allowed building regression models with minor errors when compared to the full spectrum PLS model. A RMSEP of 13.03 mg g-1for SMZ and 4.88 mg g-1 for TMP was obtained after the selection the best spectral regions by siPLS.

Distribution of radium in oil and gas industry wastes from Malaysia.

PubMed

Omar, M; Ali, H M; Abu, M P; Kontol, K M; Ahmad, Z; Ahmad, S H S S; Sulaiman, I; Hamzah, R

2004-05-01

Radium concentrations in 470 samples of the various types of waste from oil and gas industries were analysed using gamma spectrometers. The results showed that the radium concentration varied within a wide range. The highest mean 226Ra and 228Ra concentrations of 114,300 and 130,120 Bq/kg, respectively, were measured in scales. Overall, 75% of the waste, mostly sludge and extraction residue lies within the normal range of radium concentration in soils of Malaysia. However, some platform sludge can have radium concentration up to 560 Bq/kg.

Comparison of two-concentration with multi-concentration linear regressions: Retrospective data analysis of multiple regulated LC-MS bioanalytical projects.

PubMed

Musuku, Adrien; Tan, Aimin; Awaiye, Kayode; Trabelsi, Fethi

2013-09-01

Linear calibration is usually performed using eight to ten calibration concentration levels in regulated LC-MS bioanalysis because a minimum of six are specified in regulatory guidelines. However, we have previously reported that two-concentration linear calibration is as reliable as or even better than using multiple concentrations. The purpose of this research is to compare two-concentration with multiple-concentration linear calibration through retrospective data analysis of multiple bioanalytical projects that were conducted in an independent regulated bioanalytical laboratory. A total of 12 bioanalytical projects were randomly selected: two validations and two studies for each of the three most commonly used types of sample extraction methods (protein precipitation, liquid-liquid extraction, solid-phase extraction). When the existing data were retrospectively linearly regressed using only the lowest and the highest concentration levels, no extra batch failure/QC rejection was observed and the differences in accuracy and precision between the original multi-concentration regression and the new two-concentration linear regression are negligible. Specifically, the differences in overall mean apparent bias (square root of mean individual bias squares) are within the ranges of -0.3% to 0.7% and 0.1-0.7% for the validations and studies, respectively. The differences in mean QC concentrations are within the ranges of -0.6% to 1.8% and -0.8% to 2.5% for the validations and studies, respectively. The differences in %CV are within the ranges of -0.7% to 0.9% and -0.3% to 0.6% for the validations and studies, respectively. The average differences in study sample concentrations are within the range of -0.8% to 2.3%. With two-concentration linear regression, an average of 13% of time and cost could have been saved for each batch together with 53% of saving in the lead-in for each project (the preparation of working standard solutions, spiking, and aliquoting). Furthermore, examples are given as how to evaluate the linearity over the entire concentration range when only two concentration levels are used for linear regression. To conclude, two-concentration linear regression is accurate and robust enough for routine use in regulated LC-MS bioanalysis and it significantly saves time and cost as well. Copyright © 2013 Elsevier B.V. All rights reserved.

Landscape patterns in rainforest phylogenetic signal: isolated islands of refugia or structured continental distributions?

PubMed

Kooyman, Robert M; Rossetto, Maurizio; Sauquet, Hervé; Laffan, Shawn W

2013-01-01

Identify patterns of change in species distributions, diversity, concentrations of evolutionary history, and assembly of Australian rainforests. We used the distribution records of all known rainforest woody species in Australia across their full continental extent. These were analysed using measures of species richness, phylogenetic diversity (PD), phylogenetic endemism (PE) and phylogenetic structure (net relatedness index; NRI). Phylogenetic structure was assessed using both continental and regional species pools. To test the influence of growth-form, freestanding and climbing plants were analysed independently, and in combination. Species richness decreased along two generally orthogonal continental axes, corresponding with wet to seasonally dry and tropical to temperate habitats. The PE analyses identified four main areas of substantially restricted phylogenetic diversity, including parts of Cape York, Wet Tropics, Border Ranges, and Tasmania. The continental pool NRI results showed evenness (species less related than expected by chance) in groups of grid cells in coastally aligned areas of species rich tropical and sub-tropical rainforest, and in low diversity moist forest areas in the south-east of the Great Dividing Range and in Tasmania. Monsoon and drier vine forests, and moist forests inland from upland refugia showed phylogenetic clustering, reflecting lower diversity and more relatedness. Signals for evenness in Tasmania and clustering in northern monsoon forests weakened in analyses using regional species pools. For climbing plants, values for NRI by grid cell showed strong spatial structuring, with high diversity and PE concentrated in moist tropical and subtropical regions. Concentrations of rainforest evolutionary history (phylo-diversity) were patchily distributed within a continuum of species distributions. Contrasting with previous concepts of rainforest community distribution, our findings of continuous distributions and continental connectivity have significant implications for interpreting rainforest evolutionary history and current day ecological processes, and for managing rainforest diversity in changing circumstances.

Intracellular metabolites of mercaptopurine in children with lymphoblastic leukaemia: a possible indicator of non-compliance?

PubMed

Lennard, L; Welch, J; Lilleyman, J S

1995-10-01

As part of a programme assessing the pharmacokinetics of oral thiopurines given for lymphoblastic leukaemia, we assayed intracellular metabolites of mercaptopurine in children from all over the United Kingdom who were given a standard dose of the drug. The metabolites we measured, thioguanine nucleotides and methylmercaptopurines, are products of two competing metabolic pathways and would be expected to show an inverse correlation. A total of 327 children from 17 centres in the UK were studied. All were on the same therapeutic schedule of mercaptopurine. All had been on an unattenuated full protocol-directed dose (at least 75 mg m-2) for a minimum of 7 days before assay. There was a very wide variation in the concentration of the two metabolites measured; the thioguanine nucleotides ranged from 0 to 1255 pmol per 8 x 10(8) red cells (median 289, lower quartile 210, upper quartile 377) and the methylmercaptopurine metabolites ranged from 0 to 46.3 nmol per 8 x 10(8) red cells (median 5.18, lower quartile 2.31, upper quartile 11.59). The anticipated negative correlation was not apparent, but the ratio between the two was not randomly distributed. No child had both metabolite concentrations in the upper quartiles, but in 32 (10%) children the concentration of both metabolites was in the lower quartile. Of the 32, only one metabolite was detected in four and none at all in six. The most likely explanation for these findings is that a minority of children with lymphoblastic leukaemia fail to take oral mercaptopurine either totally or intermittently. The extent of the problem is unknown, but we suspect it may be clinically important in at least 10% of patients.

Intracellular metabolites of mercaptopurine in children with lymphoblastic leukaemia: a possible indicator of non-compliance?

PubMed Central

Lennard, L.; Welch, J.; Lilleyman, J. S.

1995-01-01

As part of a programme assessing the pharmacokinetics of oral thiopurines given for lymphoblastic leukaemia, we assayed intracellular metabolites of mercaptopurine in children from all over the United Kingdom who were given a standard dose of the drug. The metabolites we measured, thioguanine nucleotides and methylmercaptopurines, are products of two competing metabolic pathways and would be expected to show an inverse correlation. A total of 327 children from 17 centres in the UK were studied. All were on the same therapeutic schedule of mercaptopurine. All had been on an unattenuated full protocol-directed dose (at least 75 mg m-2) for a minimum of 7 days before assay. There was a very wide variation in the concentration of the two metabolites measured; the thioguanine nucleotides ranged from 0 to 1255 pmol per 8 x 10(8) red cells (median 289, lower quartile 210, upper quartile 377) and the methylmercaptopurine metabolites ranged from 0 to 46.3 nmol per 8 x 10(8) red cells (median 5.18, lower quartile 2.31, upper quartile 11.59). The anticipated negative correlation was not apparent, but the ratio between the two was not randomly distributed. No child had both metabolite concentrations in the upper quartiles, but in 32 (10%) children the concentration of both metabolites was in the lower quartile. Of the 32, only one metabolite was detected in four and none at all in six. The most likely explanation for these findings is that a minority of children with lymphoblastic leukaemia fail to take oral mercaptopurine either totally or intermittently. The extent of the problem is unknown, but we suspect it may be clinically important in at least 10% of patients. PMID:7547211

Potentiation by cholinesterase inhibitors of cholinergic activity in rat isolated stomach and colon.

PubMed

Jarvie, Emma M; Cellek, Selim; Sanger, Gareth J

2008-01-01

Acetylcholinesterase (AChE) inhibitors stimulate gastrointestinal (GI) motility and are potential treatments of conditions associated with inadequate GI motility. The ability of itopride to facilitate neuronally (predominantly cholinergic) mediated contractions of rat isolated stomach, evoked by electrical field stimulation (EFS), has been compared with other cholinesterase inhibitors and with tegaserod, a clinically effective prokinetic and non-selective 5-HT(4) receptor agonist which also facilitates GI cholinergic function. Neostigmine greatly increased EFS-evoked contractions over a narrow concentration range (0.01-1 microM; 754+/-337% facilitation at 1 microM); higher concentrations (1, 3 microM) also increased muscle tension. Donepezil increased EFS-evoked contractions gradually over the full range of concentrations (0.01-10 microM; maximum increase 516+/-20% at 10 microM). Itopride increased the contractions even more gradually, rising to 188+/-84% at 10 microM. The butyrylcholinesterase inhibitor iso-OMPA 0.01-10 microM also increased EFS-evoked contractions, to a maximum of 36+/-5.0% at 10 microM, similar to that caused by tegaserod (35+/-5.2% increase at 1 microM). The effects of tegaserod, but not itopride were inhibited by the 5-HT(4) receptor antagonist SB-204070A 0.3 microM. In rat isolated colon, neostigmine was again the most efficacious, causing a defined maximum increase in EFS-evoked contractions (343+/-82% at 10 microM), without changing muscle tension. Maximum increases caused by donepezil and itopride were, respectively, 57.6+/-20 and 43+/-15% at 10 microM. These data indicate that the abilities of different AChE inhibitors to increase GI cholinergic activity differ markedly. Understanding the reasons is essential if AChE inhibitors are to be optimally developed as GI prokinetics.

Ultrasound-assisted hydrolysis of conjugated parabens in human urine and their determination by UPLC-MS/MS and UPLC-HRMS.

PubMed

Schlittenbauer, Linda; Seiwert, Bettina; Reemtsma, Thorsten

2016-02-01

Parabens are preservatives widely used in personal care products, pharmaceutical formulations as well as in food, and they are considered endocrine disruptors. For application in biomonitoring studies we developed a method for the determination of eight parabens from human urine. Sample preparation was enhanced and simplified by the combination of ultrasound-assisted enzymatic hydrolysis of conjugates (glucuronide and sulfate) followed by an extraction-free cleanup step. Quantification, using deuterated parabens as internal standards, was performed by ultrahigh-performance liquid chromatography coupled to either triple-quadrupole (UPLC-QqQ) or time-of-flight (UPLC-QqTOF) mass spectrometry. Full chromatographic separation of three butyl paraben isomers was achieved. Limits of quantification for both mass analyzers ranged from 0.1 to 0.5 μg/L for methyl, ethyl, n-/isopropyl, n-/isobutyl, and benzyl paraben in 200 μL of urine sample. The method was tested for applicability and showed high precision (intra- and interday 0.9-14.5%) as well as high accuracy (relative recovery 95-132%). A total of 39 urine samples were analyzed by both mass analyzers. The results agreed well, with a trend to higher deviation at low concentrations (less than 10 μg/L). Methyl, ethyl, and n-propyl paraben were detected most frequently (in more than 87% of the samples) with median concentrations ranging from 0.8 to 16.6 μg/L. Female urine showed higher median concentrations for all parabens, which may indicate higher exposure due to lifestyle. This method permits accurate and high-throughput analysis of parabens for epidemiological studies. Further, the UPLC-QqTOF approach provides additional information on human exposure to other compounds by post-acquisition analysis.

Factors affecting emulsion stability and quality of oil recovered from enzyme-assisted aqueous extraction of soybeans.

PubMed

Jung, S; Maurer, D; Johnson, L A

2009-11-01

The objectives of the present study were to assess how the stability of the emulsion recovered from aqueous extraction processing of soybeans was affected by characteristics of the starting material and extraction and demulsification conditions. Adding endopeptidase Protex 6L during enzyme-assisted aqueous extraction processing (EAEP) of extruded soybean flakes was vital to obtaining emulsions that were easily demulsified with enzymes. Adding salt (up to 1.5 mM NaCl or MgCl(2)) during extraction and storing extruded flakes before extraction at 4 and 30 degrees C for up to 3 months did not affect the stabilities of emulsions recovered from EAEP of soy flour, flakes and extruded flakes. After demulsification, highest free oil yield was obtained with EAEP of extruded flakes, followed by flour and then flakes. The same protease used for the extraction step was used to demulsify the EAEP cream emulsion from extruded full-fat soy flakes at concentrations ranging from 0.03% to 2.50% w/w, incubation times ranging from 2 to 90 min, and temperatures of 25, 50 or 65 degrees C. Highest free oil recoveries were achieved at high enzyme concentrations, mild temperatures, and short incubation times. Both the nature of enzyme (i.e., protease and phospholipase), added alone or as a cocktail, concentration of enzymes (0.5% vs. 2.5%) and incubation time (1 vs. 3 h), use during the extraction step, and nature of enzyme added for demulsifying affected free oil yield. The free oil recovered from EAEP of extruded flakes contained less phosphorus compared with conventional hexane-extracted oil. The present study identified conditions rendering the emulsion less stable, which is critical to increasing free oil yield recovered during EAEP of soybeans, an environmentally friendly alternative processing method to hexane extraction.

Effects of low-fat or full-fat fermented and non-fermented dairy foods on selected cardiovascular biomarkers in overweight adults.

PubMed

Nestel, Paul J; Mellett, Natalie; Pally, Suzana; Wong, Gerard; Barlow, Chris K; Croft, Kevin; Mori, Trevor A; Meikle, Peter J

2013-12-01

The association between consumption of full-fat dairy foods and CVD may depend partly on the nature of products and may not apply to low-fat dairy foods. Increased circulating levels of inflammatory biomarkers after consumption of dairy product-rich meals suggest an association with CVD. In the present study, we tested the effects of low-fat and full-fat dairy diets on biomarkers associated with inflammation, oxidative stress or atherogenesis and on plasma lipid classes. Within full-fat dairy diets, we also compared fermented v. non-fermented products. In a randomised cross-over study, twelve overweight/obese subjects consumed during two 3-week periods two full-fat dairy diets containing either yogurt plus cheese (fermented) or butter, cream and ice cream (non-fermented) or a low-fat milk plus yogurt diet, with the latter being consumed between and at the end of the full-fat dairy dietary periods. The concentrations of six inflammatory and two atherogenic biomarkers known to be raised in CVD were measured as well as those of plasma F2-isoprostanes and lipid classes. The concentrations of six of the eight biomarkers tended to be higher on consumption of the low-fat dairy diet than on that of the fermented dairy diet and the concentrations of two plasmalogen lipid classes reported to be associated with increased oxidisability were also higher on consumption of the low-fat dairy diet than on that of the fermented dairy diet (P< 0.001), although plasma F2-isoprostane concentrations did not differ on consumption of any of the diets. On the other hand, the concentrations of plasma sphingomyelin and IL-6 were significantly higher on consumption of the non-fermented dairy diet than on that of the low-fat dairy diet (P< 0.02). In conclusion, short-term diets containing low-fat dairy products did not lead to a more favourable biomarker profile associated with CVD risk compared with the full-fat dairy products, suggesting that full-fat fermented dairy products may be the more favourable.

222Rn and 220Rn concentrations in soil gas of Karkonosze-Izera Block (Sudetes, Poland).

PubMed

Malczewski, Dariusz; Zaba, Jerzy

2007-01-01

Soil gas 222Rn and 220Rn concentrations were measured at 18 locations in the Karkonosze-Izera Block area in southwestern Poland. Measurements were carried out in surface air and at sampling depths of 10, 40 and 80 cm. Surface air 222Rn concentrations ranged from 4 to 2160 Bq m(-3) and 220Rn ranged from 4 to 228 Bq m(-3). The concentrations for 10 and 40 cm varied from 142 Bq m(-3) to 801 kBq m(-3) and 102 Bq m(-3) to 64 kBq m(-3) for 222Rn and 220Rn, respectively. At 80 cm 222Rn concentrations ranged from 94 Bq m(-3) to >1 MBq m(-3). The 220Rn concentrations at 80 cm varied from 45 Bq m(-3) to 48 kBq m(-3). The concentration versus depth profiles for 222Rn differed for soils developed on fault zones, uranium deposits or both. Atmospheric air temperature and soil gas 222Rn and 220Rn were negatively correlated. At sampling sites with steep slopes, 220Rn concentrations decreased with depth.

Are Vancomycin Trough Concentrations Adequate for Optimal Dosing?

PubMed Central

Youn, Gilmer; Jones, Brenda; Jelliffe, Roger W.; Drusano, George L.; Rodvold, Keith A.; Lodise, Thomas P.

2014-01-01

The current vancomycin therapeutic guidelines recommend the use of only trough concentrations to manage the dosing of adults with Staphylococcus aureus infections. Both vancomycin efficacy and toxicity are likely to be related to the area under the plasma concentration-time curve (AUC). We assembled richly sampled vancomycin pharmacokinetic data from three studies comprising 47 adults with various levels of renal function. With Pmetrics, the nonparametric population modeling package for R, we compared AUCs estimated from models derived from trough-only and peak-trough depleted versions of the full data set and characterized the relationship between the vancomycin trough concentration and AUC. The trough-only and peak-trough depleted data sets underestimated the true AUCs compared to the full model by a mean (95% confidence interval) of 23% (11 to 33%; P = 0.0001) and 14% (7 to 19%; P < 0.0001), respectively. In contrast, using the full model as a Bayesian prior with trough-only data allowed 97% (93 to 102%; P = 0.23) accurate AUC estimation. On the basis of 5,000 profiles simulated from the full model, among adults with normal renal function and a therapeutic AUC of ≥400 mg · h/liter for an organism for which the vancomycin MIC is 1 mg/liter, approximately 60% are expected to have a trough concentration below the suggested minimum target of 15 mg/liter for serious infections, which could result in needlessly increased doses and a risk of toxicity. Our data indicate that adjustment of vancomycin doses on the basis of trough concentrations without a Bayesian tool results in poor achievement of maximally safe and effective drug exposures in plasma and that many adults can have an adequate vancomycin AUC with a trough concentration of <15 mg/liter. PMID:24165176

Roaring forties: An analysis of a decadal series of data of dust in Northern Patagonia

NASA Astrophysics Data System (ADS)

Crespi-Abril, Augusto César; Soria, Gaspar; De Cian, Antonella; López-Moreno, Claudio

2018-03-01

The objective of this study is to analyze the daily variation of aeolian dust in Puerto Madryn, Patagonia, Argentina, based on a series of data of more than 11 years (from December 2004 to April 2016). In order to accomplish it, atmospheric dust was collected by means of a high volume sampler placed at the El Tehuelche airport located at 10 km westward from Puerto Madryn. A correlation between aeolian dust and wind intensity was studied. An elemental and mineral composition and granulometry analyses of dust particles were performed. Monthly aeolian dust concentration ranged between 1ug*m-3 and 2700ug*m-3. Volcanic eruptions ocurred throughout the study. The effects of volcanoes activities were evident and signifincatly increased the concentration of dust by the massive emission of ashes into the atmosphere. Thus, the mean monthly variation of dust concentration was analyzed considering the full data set and a sub-set of those years without volcanic eruptions. In the first case, the variation did not presents a pattern of variation, whereas, in the second case, a clear seassonal pattern was observed. Minimum dust concentration was recorded in Winter (20μg*m-3) and maximum in Summer (60μg*m-3). The correlation between dust concentration and wind intensity was lower than 0.5, suggesting that other factors (e.g. soil moisture and vegetation coverage) may play an important role on the suspension of mineral particles in the study region. The elemental composition was characterized by a high proportion of Si and O, whereas Fe, S, K, Mg, and P were present in a lower proportion. Clasts were mostly silicates such as quartz, horblende, and plagioclase. The granulometry was studied using a subset of 10 filters. The mean size of dust particles was 11 μm and ranged form 0.5 μm to 120 μm. These results suggest that dust transported from Patagonia to the Southern Atlantic Ocean is permanent and highly variable and may represent and important input of Fe into the sea.

Water-Quality Assessment of the Yellowstone River Basin, Montana and Wyoming-Water Quality of Fixed Sites, 1999-2001

USGS Publications Warehouse

Miller, Kirk A.; Clark, Melanie L.; Wright, Peter R.

2005-01-01

The National Water-Quality Assessment Program of the U.S. Geological Survey initiated an assessment in 1997 of the quality of water resources in the Yellowstone River Basin. Water-quality samples regularly were collected during 1999-2001 at 10 fixed sites on streams representing the major environmental settings of the basin. Integrator sites, which are heterogeneous in land use and geology, were established on the mainstem of the Yellowstone River (4 sites) and on three major tributaries?Clarks Fork Yellowstone River (1 site), the Bighorn River (1 site), and the Powder River (1 site). Indicator sites, which are more homogeneous in land use and geology than the integrator sites, were located on minor tributaries with important environmental settings?Soda Butte Creek in a mineral resource area (1 site), the Tongue River in a forested area (1 site), and the Little Powder River in a rangeland area (1 site). Water-quality sampling frequency generally was at least monthly and included field measurements and laboratory analyses of fecal-indicator bacteria, major ions, dissolved solids, nutrients, trace elements, pesticides, and suspended sediment. Median concentrations of fecal coliform and Escherichia coli were largest for basins that were predominantly rangeland and smallest for basins that were predominantly forested. Concentrations of fecal coliform and Escherichia coli significantly varied by season (p-value <0.001); the smallest median concentrations were during January?March and the largest median concentrations were during April?June. Fecal-coliform concentrations exceeded the U.S. Environmental Protection Agency recommended limit for a single sample of 400 colonies per 100 milliliters in 2.6 percent of all samples. Escherichia coli concentrations exceeded the U.S. Environmental Protection Agency recommended limit for a single sample of 298 colonies per 100 milliliters for moderate use, full-body contact recreation in 7.6 percent of all samples. Variations in water type in the basin are reflective of the diverse geologic terrain in the Yellowstone River Basin. The water type of Soda Butte Creek and the Tongue River was calcium bicarbonate. These two sites are in forested and mountainous areas where igneous rocks and Paleozoic-era and Mesozoic-era sedimentary rocks are the dominant geologic groups. The water type of the Little Powder River was sodium sulfate. The Little Powder River originates in the plains, and geology of the basin is nearly homogenous with Tertiary-period sedimentary rocks. Water type of the Yellowstone River changed from a mixed-cation bicarbonate type upstream to a mixed-cation sulfate type downstream. Dissolved-solids concentrations ranged from fairly dilute in Soda Butte Creek, which had a median concentration of 118 milligrams per liter, to concentrated in the Little Powder River, which had a median concentration of 2,840 milligrams per liter. Nutrient concentrations generally were small and reflect the relatively undeveloped conditions in the basin; however, some correlations were made with anthropogenic factors. Median dissolved-nitrate concentrations in all samples from the fixed sites ranged from 0.04 milligram per liter to 0.54 milligram per liter. Flow-weighted mean dissolved-nitrate concentrations were positively correlated with increasing agricultural land use and rangeland on alluvial deposits upstream from the sites and negatively correlated with increasing forested land. Ammonia concentrations generally were largest in samples collected from the Yellowstone River at Corwin Springs, Montana, which is downstream from Yellowstone National Park and receives discharge from geothermal waters that are high in ammonia. Median total-phosphorus concentrations ranged from 0.007 to 0.18 milligram per liter. Median total-phosphorus concentrations exceeded the U.S. Environmental Protection Agency's recommended goal of 0.10 milligram per liter for preventing nuisance plant growth for samples collec

Concentrations and cycling of DMS, DMSP, and DMSO in coastal and offshore waters of the Subarctic Pacific during summer, 2010-2011

NASA Astrophysics Data System (ADS)

Asher, Elizabeth; Dacey, John W.; Ianson, Debby; Peña, Angelica; Tortell, Philippe D.

2017-04-01

Concentrations of dimethylsulfide (DMS), measured in the Subarctic Pacific during summer 2010 and 2011, ranged from ˜1 to 40 nM, while dissolved dimethylsulfoxide (DMSO) concentrations (range 13-23 nM) exceeded those of dissolved dimethyl sulfoniopropionate (DMSP) (range 1.3-8.8 nM). Particulate DMSP dominated the reduced sulfur pool, reaching maximum concentrations of 100 nM. Coastal and off shore waters exhibited similar overall DMS concentration ranges, but sea-air DMS fluxes were lower in the oceanic waters due to lower wind speeds. Surface DMS concentrations showed statistically significant correlations with various hydrographic variables including the upwelling intensity (r2 = 0.52, p < 0.001) and the Chlorophyll a/mixed layer depth ratio (r2 = 0.52, p < 0.001), but these relationships provided little predictive power at small scales. Stable isotope tracer experiments indicated that the DMSP cleavage pathway always exceeded the DMSO reduction pathway as a DMS source, leading to at least 85% more DMS production in each experiment. Gross DMS production rates were positively correlated with the upwelling intensity, while net rates of DMS production were significantly correlated to surface water DMS concentrations. This latter result suggests that our measurements captured dominant processes driving surface DMS accumulation across a coastal-oceanic gradient.

Biological and associated water-quality data for lower Olmos Creek and upper San Antonio River, San Antonio, Texas, April - September 1989

USGS Publications Warehouse

Taylor, R. Lynn; Ferreira, Rodger F.

1995-01-01

Biological and associated water-quality data were collected from lower Olmos Creek and upper San Antonio River in San Antonio, Texas, during April-September 1989. Benthic macroinvertebrate, periphyton, and phytoplankton communities were sampled at three sites along the Olmos Creek/San Antonio River system. Total mean densities of benthic macroinvertebrates for the three sites ranged from 670 to 10,000 organisms per square meter. The most abundant macroinvertebrates were the class Insecta (insects). Total densities of periphyton ranged from 2,900 to 110,000 cells per square millimeter. Cyanophyta (blue-green algae) and Bacillariophyta (diatoms) were the predominant periphyton organisms. Total densities of phyto- plankton ranged from 5,000 to 47,000 cells per square milliliter. Blue-green algae accounted for more than one- half of the phytoplankton in each sample. Hardness ranged from 160 to 250 milligrams per liter as calcium carbonate, and alkalinity ranged from 130 to 220 milligrams per liter as calcium carbonate. The largest dissolved nitrite concentration was 0.038 milligram per liter. The largest total phosphorus concentration was 0.150 milligram per liter, over one-half of which was dissolved orthophosphate. Total aluminum and total iron were the only trace elements in water to exceed the reporting threshold by large concen- trations. Total aluminum concentrations ranged from 70 to 280 micrograms per liter, and total iron concentrations ranged from 70 to 340 micrograms per liter. Lead was the most prominent trace element in bottom-material samples, with concentrations ranging from 30 to 230 micrograms per gram.

Extended range chemical sensing apparatus

DOEpatents

Hughes, Robert C.; Schubert, W. Kent

1994-01-01

An apparatus for sensing chemicals over extended range of concentrations. In particular, first and second sensors each having separate, but overlapping ranges for sensing concentrations of hydrogen are provided. Preferably, the first sensor is a MOS solid state device wherein the metal electrode or gate is a nickel alloy. The second sensor is a chemiresistor comprising a nickel alloy.

Background hydrologic information in potential lignite mining areas in north-central Mississippi, August 1984

USGS Publications Warehouse

Kalkhoff, S.J.

1985-01-01

The U.S. Geological Survey, in cooperation with the Mississippi Department of Natural Resources, Bureau of Geology, is conducting a hydrologic data collection program in potential lignite-producing areas in Mississippi. During the last two weeks of August 1984, hydrologic data were collected at 15 stream sites that drain potential lignite mining areas in Lafayette, Calhoun, and Yalobusha Counties. Main channel widths ranged from approximately 60 feet at three streams (Coon Creek near Toccopula, Muckaloon Creek near Tula, and Hurricane Creek near Velma) to approximately 120 feet at two streams (Potlockney Creek near Tula, and Savannah Creek near Bruce). Maximum water depths ranged from less than 1.0 foot at most streams to over 5.0 feet at sites on Potlockney Creek near Tula and McGill Creek near Sarepta. Stream discharge ranged from 0.32 cubic feet per second in Persimmon Creek near Bruce to 18.5 cubic feet per second in Puskus Creek near Etta. The specific conductance of stream water ranged from 25 to 160 microsiemens and dissolved solids concentrations ranged from 22 to 91 mg/L (milligrams per liter). Most major ion concentrations were less than 10 mg/L with the exception of calcium (11 mg/L), sodium (12 mg/L) and sulfate (18 mg/L) in the water of Persimmon Creek near Bruce. Dissolved oxygen concentrations were greater than 5.0 mg/L at all but one site. Turbidity values were generally less than 50 units. Nitrate plus nitrite concentrations were equal to or less than 0.10 mg/L in all streams except in Potlockney Creek near Tula where the concentration was 0.11 mg/L. Copper and selenium concentrations in the water at all sampling sites ranged from below the detection limits (1 microgram/g) to 4 micrograms/g (micrograms per gram) and mercury concentrations in bottom material samples ranged from less than 0.01 microgram/g to 0.15 microgram/g. (USGS)

UK hazard assessment for a Laki-type volcanic eruption: modelling results for sulphur dioxide and sulphate aerosol

NASA Astrophysics Data System (ADS)

Witham, Claire; Vieno, Massimo; Schmidt, Anja; Aspinall, Willy; Braban, Christine; Hort, Matthew; Loughlin, Sue

2015-04-01

In response to the recent introduction of large gas-rich volcanic eruptions to the UK National Risk Register a modelling project has been conducted to improve our understanding of potential impacts to the UK from such an eruption on Iceland. A precautionary reasonable worst case eruption scenario based on the 1783-4 Laki eruption has been modelled 80 times using two different atmospheric chemistry and transport models (NAME and EMEP4UK) over 10 years of meteorology. The results provide information on the range of concentrations of sulphur dioxide gas (SO2), sulphate aerosol (SO4) and some halogen species that might be experienced in the UK during such an eruption and the likelihood of key thresholds being exceeded and over what durations. Data for the surface and for a range of key flight levels have been produced. In this presentation we will evaluate the ambient mass concentrations of SO2 and SO4 that could be experienced during and following such an eruption, as well as the likelihood of key health concentration thresholds being exceeded, and the maximum duration that levels could persist for. The prevailing meteorological conditions are the key influence on which parts of the North Atlantic and European region are affected at any time. The results demonstrate that the UK is unlikely to be affected by week after week of significantly elevated concentrations; rather there will a number of short (hours to days) pollution episodes where concentrations would be elevated above Moderate and High air quality index levels at the surface. This pattern fits with the generally changeable nature of the weather in the UK. Consecutive exceedance durations are longer for sulphate aerosol than SO2, and can be particularly lengthy in the low air quality index levels (1-2 weeks), which may be of relevance to health impact assessments. This work represents a detailed initial study but has not explored the full range of such an eruption. Nonetheless, the results from this project are informing cross-Government work to improve the understanding of the risk to the UK from an effusive gas-rich eruption in Iceland. This includes the production of area-specific impact assessments for sectors including health, aviation and environment. "This work is distributed under the Creative Commons Attribution 3.0 Unported License together with an author copyright. This license does not conflict with the regulations of the Crown Copyright."

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

PubMed

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

1995-12-01

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

Determination of boldenone sulfoconjugate and related steroid sulfates in equine urine by high-performance liquid chromatography/tandem mass spectrometry.

PubMed

Weidolf, L O; Lee, E D; Henion, J D

1988-03-01

Sulfoconjugated anabolic steroids were separated by micro-bore high-performance liquid chromatography. The eluent was introduced into the atmospheric pressure ion source of the triple-quadrupole mass spectrometer via an ion spray liquid chromatograph/mass spectrometer interface operated in the negative ion mode. The limit of detection was 10 pg on-column by selected ion monitoring of the molecular ion and the response increased linearly over a concentration range of 2.4 orders of magnitude. Following work-up by a liquid-solid extraction procedure of equine urine samples, full-scan daughter ion spectra of boldenone sulfate could be obtained up to 17 days after a therapeutic dose of boldenone undecylenate to a horse.

Wind-Tunnel Evaluation of the Effect of Blade Nonstructural Mass Distribution on Helicopter Fixed-System Loads

NASA Technical Reports Server (NTRS)

Wilbur, Matthew L.; Yeager, William T., Jr.; Singleton, Jeffrey D.; Mirick, Paul H.; Wilkie, W. Keats

1998-01-01

This report provides data obtained during a wind-tunnel test conducted to investigate parametrically the effect of blade nonstructural mass on helicopter fixed-system vibratory loads. The data were obtained with aeroelastically scaled model rotor blades that allowed for the addition of concentrated nonstructural masses at multiple locations along the blade radius. Testing was conducted for advance ratios ranging from 0.10 to 0.35 for 10 blade-mass configurations. Three thrust levels were obtained at representative full-scale shaft angles for each blade-mass configuration. This report provides the fixed-system forces and moments measured during testing. The comprehensive database obtained is well-suited for use in correlation and development of advanced rotorcraft analyses.

Preliminary Geologic/spectral Analysis of LANDSAT-4 Thematic Mapper Data, Wind River/bighorn Basin Area, Wyoming

NASA Technical Reports Server (NTRS)

Lang, H. R.; Conel, J. E.; Paylor, E. D.

1984-01-01

A LIDQA evaluation for geologic applications of a LANDSAT TM scene covering the Wind River/Bighorn Basin area, Wyoming, is examined. This involves a quantitative assessment of data quality including spatial and spectral characteristics. Analysis is concentrated on the 6 visible, near infrared, and short wavelength infrared bands. Preliminary analysis demonstrates that: (1) principal component images derived from the correlation matrix provide the most useful geologic information. To extract surface spectral reflectance, the TM radiance data must be calibrated. Scatterplots demonstrate that TM data can be calibrated and sensor response is essentially linear. Low instrumental offset and gain settings result in spectral data that do not utilize the full dynamic range of the TM system.

A low volume 3D-printed temperature-controllable cuvette for UV visible spectroscopy.

PubMed

Pisaruka, Jelena; Dymond, Marcus K

2016-10-01

We report the fabrication of a 3D-printed water-heated cuvette that fits into a standard UV visible spectrophotometer. Full 3D-printable designs are provided and 3D-printing conditions have been optimised to provide options to print the cuvette in either acrylonitrile butadiene styrene or polylactic acid polymers, extending the range of solvents that are compatible with the design. We demonstrate the efficacy of the cuvette by determining the critical micelle concentration of sodium dodecyl sulphate at 40 °C, the molar extinction coefficients of cobalt nitrate and dsDNA and by reproducing the thermochromic UV visible spectrum of a mixture of cobalt chloride, water and propan-2-ol. Copyright © 2016 Elsevier Inc. All rights reserved.

In-situ determination of energy species yields of intense particle beams

DOEpatents

Kugel, H.W.; Kaita, R.

1983-09-26

Objects of the present invention are provided for a particle beam having a full energy component at least as great as 25 keV, which is directed onto a beamstop target, such that Rutherford backscattering, preferably near-surface backscattering occurs. The geometry, material composition and impurity concentration of the beam stop are predetermined, using any suitable conventional technique. The energy-yield characteristic response of backscattered particles is measured over a range of angles using a fast ion electrostatic analyzer having a microchannel plate array at its focal plane. The knee of the resulting yield curve, on a plot of yield versus energy, is analyzed to determine the energy species components of various beam particles having the same mass.

An AeroCom Assessment of Black Carbon in Arctic Snow and Sea Ice

NASA Technical Reports Server (NTRS)

Jiao, C.; Flanner, M. G.; Balkanski, Y.; Bauer, S. E.; Bellouin, N.; Bernsten, T. K.; Bian, H.; Carslaw, K. S.; Chin, M.; DeLuca, N.;

Methods of analysis by the U.S. Geological Survey National Water Quality Laboratory; determination of 86 volatile organic compounds in water by gas chromatography/mass spectrometry, including detections less than reporting limits

USGS Publications Warehouse

Connor, Brooke F.; Rose, Donna L.; Noriega, Mary C.; Murtaugh, Lucinda K.; Abney, Sonja R.

1998-01-01

This report presents precision and accuracy data for volatile organic compounds (VOCs) in the nanogram-per-liter range, including aromatic hydrocarbons, reformulated fuel components, and halogenated hydrocarbons using purge and trap capillary-column gas chromatography/mass spectrometry. One-hundred-four VOCs were initially tested. Of these, 86 are suitable for determination by this method. Selected data are provided for the 18 VOCs that were not included. This method also allows for the reporting of semiquantitative results for tentatively identified VOCs not included in the list of method compounds. Method detection limits, method performance data, preservation study results, and blank results are presented. The authors describe a procedure for reporting low-concentration detections at less than the reporting limit. The nondetection value (NDV) is introduced as a statistically defined reporting limit designed to limit false positives and false negatives to less than 1 percent. Nondetections of method compounds are reported as ?less than NDV.? Positive detections measured at less than NDV are reported as estimated concentrations to alert the data user to decreased confidence in accurate quantitation. Instructions are provided for analysts to report data at less than the reporting limits. This method can support the use of either method reporting limits that censor detections at lower concentrations or the use of NDVs as reporting limits. The data-reporting strategy for providing analytical results at less than the reporting limit is a result of the increased need to identify the presence or absence of environmental contaminants in water samples at increasingly lower concentrations. Long-term method detection limits (LTMDLs) for 86 selected compounds range from 0.013 to 2.452 micrograms per liter (?g/L) and differ from standard method detection limits (MDLs) in that the LTMDLs include the long-term variance of multiple instruments, multiple operators, and multiple calibrations over a longer time. For these reasons, LTMDLs are expected to be slightly higher than standard MDLs. Recoveries for all of the VOCs tested ranged from 36 (tert-butyl formate) to 155 percent (pentachlorobenzene). The majority of the compounds ranged from 85 to 115 percent recovery and had less than 5 percent relative standard deviation for concentrations spiked between 1 to 500 ?g/L in volatile blank-, surface-, and ground-water samples. Recoveries of 60 set spikes at low concentrations ranged from 70 to 114 percent (1,2,3- trimethylbenzene and acetone). Recovery data were collected over 6 months with multiple instruments, operators, and calibrations. In this method, volatile organic compounds are extracted from a water sample by actively purging with helium. The VOCs are collected onto a sorbent trap, thermally desorbed, separated by a Megabore gas chromatographic capillary column, and finally determined by a full-scan quadrupole mass spectrometer. Compound identification is confirmed by the gas chromatographic retention time and by the resultant mass spectrum, typically identified by three unique ions. An unknown compound detected in a sample can be tentatively identified by comparing the unknown mass spectrum to reference spectra in the mass-spectra computer-data system library compiled by the National Institute of Standards and Technology.

Evaluation of Measurements Collected with Multi-Parameter Continuous Water-Quality Monitors in Selected Illinois Streams, 2001-03

USGS Publications Warehouse

Groschen, George E.; King, Robin B.

2005-01-01

Eight streams, representing a wide range of environmental and water-quality conditions across Illinois, were monitored from July 2001 to October 2003 for five water-quality parameters as part of a pilot study by the U.S. Geological Survey (USGS) in cooperation with the Illinois Environmental Protection Agency (IEPA). Continuous recording multi-parameter water-quality monitors were installed to collect data on water temperature, dissolved-oxygen concentrations, specific conductivity, pH, and turbidity. The monitors were near USGS streamflow-gaging stations where stage and streamflow are continuously recorded. During the study period, the data collected for these five parameters generally met the data-quality objectives established by the USGS and IEPA at all eight stations. A similar pilot study during this period for measurement of chlorophyll concentrations failed to achieve the data-quality objectives. Of all the sensors used, the temperature sensors provided the most accurate and reliable measurements (generally within ?5 percent of a calibrated thermometer reading). Signal adjustments and calibration of all other sensors are dependent upon an accurate and precise temperature measurement. The dissolved-oxygen sensors were the next most reliable during the study and were responsive to changing conditions and accurate at all eight stations. Specific conductivity was the third most accurate and reliable measurement collected from the multi-parameter monitors. Specific conductivity at the eight stations varied widely-from less than 40 microsiemens (?S) at Rayse Creek near Waltonville to greater than 3,500 ?S at Salt Creek at Western Springs. In individual streams, specific conductivity often changed quickly (greater than 25 percent in less than 3 hours) and the sensors generally provided good to excellent record of these variations at all stations. The widest range of specific-conductivity measurements was in Salt Creek at Western Springs in the Greater Chicago metropolitan area. Unlike temperature, dissolved oxygen, and specific conductivity that have been typically measured over a wide range of historical streamflow conditions in many streams, there are few historical turbidity data and the full range of turbidity values is not well known for many streams. Because proposed regional criteria for turbidity in regional streams are based on upper 25th percentiles of concentration in reference streams, accurate determination of the distribution of turbidity in monitored streams is important. Digital data from all five sensors were recorded within each of the eight sondes deployed in the streams and in automated data recorders in the nearby streamflow-gaging houses at each station. The data recorded on each sonde were retrieved to a field laptop computer at each station visit. The feasibility of transmitting these data in near-real time to a central processing point for dissemination on the World-Wide Web was tested successfully. Data collected at all eight stations indicate that a number of factors affect the dissolved-oxygen concentration in the streams and rivers monitored. These factors include: temperature, biological activity, nutrient runoff, and weather (storm runoff). During brief periods usually in late summer, dissolved-oxygen concentrations in half or more of the eight streams and rivers monitored were below the 5 milligrams per liter minimum established by the Illinois Pollution Control Board to protect aquatic life. Because the streams monitored represent a wide range in water-quality and environmental conditions, including diffuse (non-point) runoff and wastewater-effluent contributions, this result indicates that deleterious low dissolved-oxygen concentrations during late summer may be widespread in Illinois streams.

Mercury and selenium concentrations in biofilm, macroinvertebrates, and fish collected in the Yankee Fork of the Salmon River, Idaho, USA, and their potential effects on fish health.

PubMed

Rhea, Darren T; Farag, Aïda M; Harper, David D; McConnell, Elizabeth; Brumbaugh, William G

2013-01-01

The Yankee Fork is a large tributary of the Salmon River located in central Idaho, USA, with an extensive history of placer and dredge-mining activities. Concentrations of selenium (Se) and mercury (Hg) in various aquatic trophic levels were measured in the Yankee Fork during 2001 and 2002. Various measurements of fish health were also performed. Sites included four on the mainstem of the Yankee Fork and two off-channel sites in partially reclaimed dredge pools used as rearing habitat for cultured salmonid eggs and fry. Hg concentrations in whole mountain whitefish and shorthead sculpin ranged from 0.28 to 0.56 μg/g dry weight (dw), concentrations that are generally less than those reported to have significant impacts on fish. Biofilm and invertebrates ranged from 0.05 to 0.43 μg Hg/g dw. Se concentrations measured in biota samples from the Yankee Fork were greater than many representative samples collected in the Snake and Columbia watersheds and often exceeded literature-based toxic thresholds. Biofilm and invertebrates ranged from 0.58 to 4.66 μg Se/g dw. Whole fish ranged from 3.92 to 7.10 μg Se/g dw, and gonads ranged from 6.91 to 31.84 μg Se/g dw. Whole-body Se concentrations exceeded reported toxicological thresholds at three of four sites and concentrations in liver samples were mostly greater than concentrations shown to have negative impacts on fish health. Histological examinations performed during this study noted liver abnormalities, especially in shorthead sculpin, a bottom-dwelling species.

Mercury and selenium concentrations in biofilm, macroinvertebrates, and fish collected in the Yankee Fork of the Salmon River, Idaho, USA, and their potential effects on fish health

USGS Publications Warehouse

Rhea, Darren T.; Farag, Aïda M.; Harper, David D.; McConnell, Elizabeth; Brumbaugh, William G.

2013-01-01

The Yankee Fork is a large tributary of the Salmon River located in central Idaho, USA, with an extensive history of placer and dredge-mining activities. Concentrations of selenium (Se) and mercury (Hg) in various aquatic trophic levels were measured in the Yankee Fork during 2001 and 2002. Various measurements of fish health were also performed. Sites included four on the mainstem of the Yankee Fork and two off-channel sites in partially reclaimed dredge pools used as rearing habitat for cultured salmonid eggs and fry. Hg concentrations in whole mountain whitefish and shorthead sculpin ranged from 0.28 to 0.56 μg/g dry weight (dw), concentrations that are generally less than those reported to have significant impacts on fish. Biofilm and invertebrates ranged from 0.05 to 0.43 μg Hg/g dw. Se concentrations measured in biota samples from the Yankee Fork were greater than many representative samples collected in the Snake and Columbia watersheds and often exceeded literature-based toxic thresholds. Biofilm and invertebrates ranged from 0.58 to 4.66 μg Se/g dw. Whole fish ranged from 3.92 to 7.10 μg Se/g dw, and gonads ranged from 6.91 to 31.84 μg Se/g dw. Whole-body Se concentrations exceeded reported toxicological thresholds at three of four sites and concentrations in liver samples were mostly greater than concentrations shown to have negative impacts on fish health. Histological examinations performed during this study noted liver abnormalities, especially in shorthead sculpin, a bottom-dwelling species.

Chromotherapy of macular degeneration with transitions lenses and green-yellow medical filters and special programme for psychoorganic disturbances.

PubMed

Vojniković, Bozo; Vojniković, Davor

2010-04-01

Optical spectrum of the sunlight consists of visible or chromatic spectrum, with the range of wavelengths of electromagnetic vibrations from 7700 to 3900 AU, and the invisible spectrum: infrared and ultraviolet. Chromatic spectrum gives rise to the sensation of colour, capable for simulating specialized retinal photoreceptors and is perceptible as light. This rule of perception of the particular range of the optical spectrum goes mainly for man, while particular deviations, more or less, are applicable to the rest of animal and plant life. The optical part of the spectrum belongs to nonionizing radiation. It created the life on the Earth, maintaining it nowadays and even threatening the human organ of vision, because the retina had not been yet adequately accommodated through evolution with its photoreactive metabolism. Human retina is very sensitive about possible harmful influence of ultraviolet and blue light even today in evolution, but also phototoxic on complete strong visible light. In their clinical and experimental work on animals, the authors prove with their own patent (P 20020077A)-Vojniković B&D, and in collaboration with Essilor Optic Austria GmbH, that particular medical filters in the range of green-yellow colour especially (565 to 570 nm), and in combination with "Transitions" successfully threat macular degeneration-AMD, slowing down its progression and having positive psychoorganic effect on the depressive mood of such patients with threatened sight. Full attention has been paid to the design of medical filter, so the periphery of the lens plays a positive role in blood concentration of melatonin, while the central part stimulates the sight and the concentration of serotonine. Thus the physiological balance of melatonin and serotonin and the stability of psychophysical disturbances have been achieved.

Performance status of a small robot-mounted or hand-held, solar-blind, standoff chemical, biological, and explosives (CBE) sensor

NASA Astrophysics Data System (ADS)

Hug, W. F.; Reid, R. D.; Bhartia, R.; Lane, A. L.

2009-05-01

Photon Systems and JPL are continuing development of a new technology robot-mounted or hand-held sensor for reagentless, short-range, standoff detection and identification of trace levels CBE materials on surfaces. This deep ultraviolet CBE sensor is the result of ongoing Army STTR and DTRA programs. The evolving 6 lb, 15W, lantern-size sensor can discriminate CBE from background clutter materials using a combination of deep UV excited resonance Raman (RR) and laser induced native fluorescence (LINF) emissions resulting from excitation by a new technology deep UV laser. Standoff excitation of suspicious packages, vehicles, persons, and other objects that may contain hazardous materials is accomplished using wavelengths below 250nm where RR and LINF emissions occupy distinctly different wavelength regions. This enables simultaneous detection of RR and LINF emissions with no spectral overlap or interference of LINF over RR or RR over LINF. The new eye-safe targeted ultraviolet chemical, biological, and explosives (TUCBE) sensor can detect and identify less than 1 μg/cm2 of explosives or 104 bacterial spores at 10 meters standoff, or 10 ng/cm2 of explosives or 102 bacterial spores/cm2 at 1 meter standoff. Detection and identification requires less than 1 ms and has a sample rate up to 20 Hz. Lower concentrations of contamination can be detected and identified as closer ranges and higher concentrations at longer ranges. The sensor is solar blind and can be operated in full daylight conditions as a result of excitation and detection in the deep UV and the use of a gated detection system.

Occupational exposure to acrylamide in closed system production plants: air levels and biomonitoring.

PubMed

Moorman, William J; Reutman, Susan S; Shaw, Peter B; Blade, Leo Michael; Marlow, David; Vesper, Hubert; Clark, John C; Schrader, Steven M

2012-01-01

The aim of this study was to evaluate biomarkers of acrylamide exposure, including hemoglobin adducts and urinary metabolites in acrylamide production workers. Biomarkers are integrated measures of the internal dose, and it is total acrylamide dose from all routes and sources that may present health risks. Workers from three companies were studied. Workers potentially exposed to acrylamide monomer wore personal breathing-zone air samplers. Air samples and surface-wipe samples were collected and analyzed for acrylamide. General-area air samples were collected in chemical processing units and control rooms. Hemoglobin adducts were isolated from ethylenediamine teraacetic acid (EDTA)-whole blood, and adducts of acrylamide and glycidamide, at the N-terminal valines of hemoglobin, were cleaved from the protein chain by use of a modified Edman reaction. Full work-shift, personal breathing zone, and general-area air samples were collected and analyzed for particulate and acrylamide monomer vapor. The highest general-area concentration of acrylamide vapor was 350 μg/cm(3) in monomer production. Personal breathing zone and general-area concentrations of acrylamide vapor were found to be highest in monomer production operations, and lower levels were in the polymer production operations. Adduct levels varied widely among workers, with the highest in workers in the monomer and polymer production areas. The acrylamide adduct range was 15-1884 pmol/g; glycidamide adducts ranged from 17.8 to 1376 p/mol/g. The highest acrylamide and glycidamide adduct levels were found among monomer production process operators. The primary urinary metabolite N-acetyl-S-(2-carbamoylethyl) cysteine (NACEC) ranged from the limit of detection to 15.4 μg/ml. Correlation of workplace exposure and sentinel health effects is needed to determine and control safe levels of exposure for regulatory standards.

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

Gough, Mallory, E-mail: m.gough1@lancaster.ac.uk; Blanthorn-Hazell, Sophee, E-mail: s.blanthorn-hazell@lancaster.ac.uk; Delury, Craig, E-mail: c.delury@lancaster.ac.uk

Highlights: • Copper levels are elevated in the tumour microenvironment. • APP mitigates copper-induced growth inhibition of DU145 prostate cancer (PCa) cells. • The APP intracellular domain is a prerequisite; soluble forms have no effect. • The E1 CuBD of APP is also a prerequisite. • APP copper binding potentially mitigates copper-induced PCa cell growth inhibition. - Abstract: Copper plays an important role in the aetiology and growth of tumours and levels of the metal are increased in the serum and tumour tissue of patients affected by a range of cancers including prostate cancer (PCa). The molecular mechanisms that enablemore » cancer cells to proliferate in the presence of elevated copper levels are, therefore, of key importance in our understanding of tumour growth progression. In the current study, we have examined the role played by the amyloid precursor protein (APP) in mitigating copper-induced growth inhibition of the PCa cell line, DU145. A range of APP molecular constructs were stably over-expressed in DU145 cells and their effects on cell proliferation in the presence of copper were monitored. Our results show that endogenous APP expression was induced by sub-toxic copper concentrations in DU145 cells and over-expression of the wild-type protein was able to mitigate copper-induced growth inhibition via a mechanism involving the cytosolic and E1 copper binding domains of the full-length protein. APP likely represents one of a range of copper binding proteins that PCa cells employ in order to ensure efficient proliferation despite elevated concentrations of the metal within the tumour microenvironment. Targeting the expression of such proteins may contribute to therapeutic strategies for the treatment of cancers.« less

Treatment of Refractory Gastrointestinal Strictures With Mitomycin C: A Systematic Review.

PubMed

Rustagi, Tarun; Aslanian, Harry R; Laine, Loren

2015-01-01

Refractory benign gastrointestinal (GI) strictures represent a difficult management problem given the limited therapeutic interventions available. We performed a systematic review of all published cases using mitomycin C in the treatment of GI strictures. Searches of MEDLINE and Embase databases were performed to identify studies reporting application of mitomycin C for GI strictures. Review of titles/abstracts, full review of potentially relevant studies, and data abstraction were performed independently by 2 authors. Of 549 citations, 24 studies with 145 patients (74% pediatric and 26% adult) met inclusion criteria. Esophageal strictures were the most common (79%) site of refractory strictures treated with mitomycin C, with caustic injury the most common underlying etiology. The concentration (range, 0.1 to 2 mg/mL; median, 0.4 mg/mL), number of applications (range, 1 to 12; median, 1), duration of applications (range, 1 to 5; median, 2 min), and technique of application (cotton pledget, spray, injection, special catheters) varied among studies. Ninety-one patients (73%; children: 80%, adults: 59%) had a complete response; 26 (21%) had a partial response. Only 1 (0.7%) adverse event was reported: cutaneous sclerosis attributed to microperforation and mitomycin C extravastion after injection. Mean follow-up was 23 (4 to 60) months. Local mitomycin C application seems to be a safe and effective therapy for benign refractory GI strictures of varying etiology in both pediatric and adult populations. Although the results of this systematic review are highly encouraging, it should be considered investigational. Additional randomized trials and larger prospective studies are needed to confirm these results and to better define the optimal dose, concentration, duration and technique of mitomycin C application.

Potential endocrine disrupting organic chemicals in treated municipal wastewater and river water

USGS Publications Warehouse

Barber, L.B.; Brown, G.K.; Zaugg, S.D.

2000-01-01

Select endocrine disrupting organic chemicals were measured in treated wastewater from Chicago, IL, Minneapolis/St. Paul, MN, Detroit, MI, and Milwaukee, WI, and in the Des Plaines, Illinois, and Minnesota Rivers during the fall of 1997 and the spring of 1998. Emphasis was given to alkylphenolpolyethoxylate (APEO) derived compounds, although 17-??-estradiol, bisphenol A, caffeine, total organic carbon, ethylenediaminetetraacetic acid (EDTA), and other compounds also were measured. Contaminants were isolated by continuous liquid-liquid extraction (CLLE) with methylene chloride and analyzed by gas chromatography/mass spectrometry in full scan and selected ion monitoring modes. The extracts were derivatized to form the methyl esters of alkylphenolethoxycarboxylates (APEC), and EDTA was isolated by evaporation and derivatized to form the tetrapropyl ester. The mass spectra of nonylphenol (NP) and octylphenol (OP) compounds are complex and show variations among the different ethoxylate and carboxylate homologs, reflecting variations in the ethylene oxide chain length. Recoveries for target compounds and surrogate standards ranged from 20-130%, with relative standard deviations of 9.9-53%. Detection limits for the various compounds ranged from 0.06-0.35 ??g/L. Analysis of the wastewater effluents detected a number of compounds including NP, NPEO, OP, OPEO, NPEC, caffeine, and EDTA at concentrations ranging from <1-439 ??g/L, with EDTA and NPEC being most abundant. There was variability in compound distributions and concentrations between the various sewage treatment plants, indicating differences in treatment type and influent composition. Several wastewater-derived compounds were detected in the river samples, with EDTA and NPEC persisting for considerable distance downstream from wastewater discharges, and NP and NPEO being attenuated more rapidly.

Frequency domain technique for a two-dimensional mapping of optical tissue properties

NASA Astrophysics Data System (ADS)

Bocher, Thomas; Beuthan, Juergen; Minet, Olaf; Naber, Rolf-Dieter; Mueller, Gerhard J.

1995-12-01

Locally and individually varying optical tissue parameters (mu) a, (mu) s, and g are responsible for non-neglectible uncertainties in the interpretation of spectroscopic data in optical biopsy techniques. The intrinsic fluorescence signal for instance doesn't depend only on the fluorophore concentration but also on the amount of other background absorbers and on alterations of scattering properties. Therefore neither a correct relative nor an absolute mapping of the lateral fluorophore concentration can be derived from the intrinsic fluorescence signal alone. Using MC-simulations it can be shown that in time-resolved LIFS the simultaneously measured backscattered signal of the excitation wavelength (UV) can be used to develop a special, linearized rescaling algorithm to take into account the most dominant of these varying tissue parameters which is (mu) a,ex. In combination with biochemical calibration measurements we were able to perform fiberbased quantitative NADH- concentration measurements. In this paper a new rescaling method for VIS and IR light in the frequency domain is proposed. It can be applied within the validity range of the diffusion approximation and provides full (mu) a and (mu) s rescaling possibility in a 2- dimensional, non-contact mapping mode. The scanning device is planned to be used in combination with a standard operation microscope of ZEISS, Germany.

Thyroid-Stimulating Hormone (TSH) Concentration at Birth in Belgian Neonates and Cognitive Development at Preschool Age.

PubMed

Trumpff, Caroline; De Schepper, Jean; Vanderfaeillie, Johan; Vercruysse, Nathalie; Van Oyen, Herman; Moreno-Reyes, Rodrigo; Tafforeau, Jean; Vanderpas, Jean; Vandevijvere, Stefanie

2015-11-02

The main objective of the study was to investigate the effect of MID during late pregnancy, assessed by the thyroid-stimulating hormone (TSH) concentration at neonatal screening, on cognitive development of preschool children. A retrospective cohort study including 311 Belgian preschool children of 4-6 years old was conducted. Children were selected at random from the total list of neonates screened in 2008, 2009, and 2010 by the Brussels new-born screening center. Infants with congenital hypothyroidism, low birth weight, and/or prematurity were excluded from the selection. The selected children were stratified by gender and TSH-range (0.45-15 mIU/L). Cognitive abilities were assessed using Wechsler Preschool and Primary Scale of Intelligence-third edition. In addition, several socioeconomic, parental, and child confounding factors were assessed. Neonatal TSH concentration-a surrogate marker for MID-was not associated with Full Scale and Performance IQ scores in children. Lower Verbal IQ scores were found in children with neonatal TSH values comprised between 10-15 mIU/L compared to lower TSH levels in univariate analysis but these results did not hold when adjusting for confounding factors. Current levels of iodine deficiency among pregnant Belgian women may not be severe enough to affect the neurodevelopment of preschool children.

Human exposures to volatile halogenated organic chemicals in indoor and outdoor air.

PubMed Central

Andelman, J B

1985-01-01

Volatile halogenated organic chemicals are found in indoor and outdoor air, often at concentrations substantially above those in remote, unpopulated areas. The outdoor ambient concentrations vary considerably among sampling stations throughout the United States, as well as diurnally and daily. The vapor pressures and air-water equilibrium (Henry's Law) constants of these chemicals influence considerably the likely relative human exposures for the air and water routes. Volatilization of chemicals from indoor uses of water can be a substantial source of exposure, as shown for radon-222. Measurements of air concentrations of trichloroethylene (TCE) in showers using TCE contaminated groundwater show increases with time to as high as one-third of occupational threshold limit values. Using a scaled down experimental shower, such volatilization and subsequent decay in air was also demonstrated. Using a simplified indoor air model and assuming complete volatilization from a full range of typical water uses within the home, calculations indicate that the expected air inhalation exposures can be substantially higher than those from ingestion of these chemicals in drinking water. Although the regulation of toxic chemicals in potable water supplies has focused traditionally on direct ingestion, the volatilization and inhalation from other much greater volume indoor uses of water should be considered as well. PMID:4085436

Concentration-Discharge Relations in the Critical Zone: Implications for Resolving Critical Zone Structure, Function, and Evolution

NASA Astrophysics Data System (ADS)

Chorover, Jon; Derry, Louis A.; McDowell, William H.

2017-11-01

Critical zone science seeks to develop mechanistic theories that describe critical zone structure, function, and long-term evolution. One postulate is that hydrogeochemical controls on critical zone evolution can be inferred from solute discharges measured down-gradient of reactive flow paths. These flow paths have variable lengths, interfacial compositions, and residence times, and their mixing is reflected in concentration-discharge (C-Q) relations. Motivation for this special section originates from a U.S. Critical Zone Observatories workshop that was held at the University of New Hampshire, 20-22 July 2015. The workshop focused on resolving mechanistic CZ controls over surface water chemical dynamics across the full range of lithogenic (e.g., nonhydrolyzing and hydrolyzing cations and oxyanions) and bioactive solutes (e.g., organic and inorganic forms of C, N, P, and S), including dissolved and colloidal species that may cooccur for a given element. Papers submitted to this special section on "concentration-discharge relations in the critical zone" include those from authors who attended the workshop, as well as others who responded to the open solicitation. Submissions were invited that utilized information pertaining to internal, integrated catchment function (relations between hydrology, biogeochemistry, and landscape structure) to help illuminate controls on observed C-Q relations.

Phytoremediation of sewage sludge and use of its leachate for crop production.

PubMed

Xu, Tianfen; Xie, Fangwen; Wei, Zebin; Zeng, Shucai; Wu, Qi-Tang

2015-01-01

The land application of sewage sludge has the potential risk of transferring heavy metals to soil or groundwater. The agricultural reuse of sludge leachate could be a cost-effective way to decrease metal contamination. Sludge leachate collected during the phytoremediation of sludge by co-cropping with Sedum alfredii and Zea mays was used for irrigating vegetables in a field experiment. Results indicate that the concentrations of Cu, Zn, Pb, and Cd in sludge leachates complied with the National Standards for agricultural irrigation water in China. For the vegetable crop Ipomoea aquatica, nutrients obtained only from the sludge leachate were not sufficient to support growth. For the second crop, Brassica parachinensis, no differences in biomass were observed between the treatment with leachate plus a half dose of inorganic fertilizer and the treatment with a full dose of inorganic fertilizers. The concentrations of heavy metals in I. aquatica and B. parachinensis were not significantly affected by the application of sludge leachates. Compared with initial values, there were no significant differences in Zn, Cd, Cu, and Pb concentrations in soil following treatment with sludge leachate. This study indicates that on range lands, sludge phytoremediation can be conducted at the upper level, and the generated sludge leachate can be safely and easily used in crop production at the lower level.

Adding spatial flexibility to source-receptor relationships for air quality modeling.

PubMed

Pisoni, E; Clappier, A; Degraeuwe, B; Thunis, P

2017-04-01

To cope with computing power limitations, air quality models that are used in integrated assessment applications are generally approximated by simpler expressions referred to as "source-receptor relationships (SRR)". In addition to speed, it is desirable for the SRR also to be spatially flexible (application over a wide range of situations) and to require a "light setup" (based on a limited number of full Air Quality Models - AQM simulations). But "speed", "flexibility" and "light setup" do not naturally come together and a good compromise must be ensured that preserves "accuracy", i.e. a good comparability between SRR results and AQM. In this work we further develop a SRR methodology to better capture spatial flexibility. The updated methodology is based on a cell-to-cell relationship, in which a bell-shape function links emissions to concentrations. Maintaining a cell-to-cell relationship is shown to be the key element needed to ensure spatial flexibility, while at the same time the proposed approach to link emissions and concentrations guarantees a "light set-up" phase. Validation has been repeated on different areas and domain sizes (countries, regions, province throughout Europe) for precursors reduced independently or contemporarily. All runs showed a bias around 10% between the full AQM and the SRR. This methodology allows assessing the impact on air quality of emission scenarios applied over any given area in Europe (regions, set of regions, countries), provided that a limited number of AQM simulations are performed for training.

Characterization, mapping, and mitigation of mercury vapour emissions from artisanal mining gold shops.

PubMed

Cordy, Paul; Veiga, Marcello; Crawford, Ben; Garcia, Oseas; Gonzalez, Victor; Moraga, Daniel; Roeser, Monika; Wip, Dennis

2013-08-01

Artisanal miners sell their gold to shops that are usually located in the urban core, where the mercury-gold amalgam is burned to evaporate the mercury that was added during ore processing. People living and working near these gold shops are exposed to intermittent and extreme concentrations of mercury vapour. In the urban centres of Segovia, Colombia, and Andacollo, Chile, the average concentrations measured by mobile mercury vapour analyzer transects taken repeatedly over several weeks were 1.26 and 0.338μgm(-3), respectively. By World Health Organization standards, these towns are exposed to significant health hazard, and globally, the millions of miners, as well as non-miners who live near gold shops, are at serious risk of neurological and renal deficits. Measurements taken in Suriname, Ecuador and Peru reveal this to be a widespread phenomenon with unique regional variations and myriad attempts at remediation. Maps of average mercury concentrations show the spatial distribution of the hazard in relation to residential buildings and schools. Measurements from towers show the temporal variability of mercury concentrations, and suggest that large quantities of mercury are available for long-range atmospheric transport. Mercury mapping in Segovia in 2011 suggest a 10% reduction in airborne mercury concentrations over 2010, despite a 30% increase in gold production. This is attributable to the adoption of retorts by miners and regulations banning new processing centres to the rural periphery. This is the first full description of artisanal mining gold shop practices and of the character, quantity, and remediation of mercury emissions within urban mining centres. Copyright © 2013 Elsevier Inc. All rights reserved.

Modelling the maximum voluntary joint torque/angular velocity relationship in human movement.

PubMed

Yeadon, Maurice R; King, Mark A; Wilson, Cassie

2006-01-01

The force exerted by a muscle is a function of the activation level and the maximum (tetanic) muscle force. In "maximum" voluntary knee extensions muscle activation is lower for eccentric muscle velocities than for concentric velocities. The aim of this study was to model this "differential activation" in order to calculate the maximum voluntary knee extensor torque as a function of knee angular velocity. Torque data were collected on two subjects during maximal eccentric-concentric knee extensions using an isovelocity dynamometer with crank angular velocities ranging from 50 to 450 degrees s(-1). The theoretical tetanic torque/angular velocity relationship was modelled using a four parameter function comprising two rectangular hyperbolas while the activation/angular velocity relationship was modelled using a three parameter function that rose from submaximal activation for eccentric velocities to full activation for high concentric velocities. The product of these two functions gave a seven parameter function which was fitted to the joint torque/angular velocity data, giving unbiased root mean square differences of 1.9% and 3.3% of the maximum torques achieved. Differential activation accounts for the non-hyperbolic behaviour of the torque/angular velocity data for low concentric velocities. The maximum voluntary knee extensor torque that can be exerted may be modelled accurately as the product of functions defining the maximum torque and the maximum voluntary activation level. Failure to include differential activation considerations when modelling maximal movements will lead to errors in the estimation of joint torque in the eccentric phase and low velocity concentric phase.

Effects of contaminated soil on the growth performance of young Salix (Salix schwerinii E. L. Wolf) and the potential for phytoremediation of heavy metals.

PubMed

Salam, Mir Md Abdus; Kaipiainen, Erik; Mohsin, Muhammad; Villa, Aki; Kuittinen, Suvi; Pulkkinen, Pertti; Pelkonen, Paavo; Mehtätalo, Lauri; Pappinen, Ari

2016-12-01

Salix schwerinii was tested in a pot experiment to assess plant growth performance i.e., relative height and dry biomass and the potential for heavy metal uptake in soils polluted with chromium, zinc, copper, nickel and total petroleum hydrocarbons. The soil used in the pot experiment was collected from a landfill area in Finland. Peat soil was added at different quantities to the polluted soil to stimulate plant growth. The plants were irrigated with tap water or processed water (municipal waste water) to further investigate the effects of nutrient loading on plant biomass growth. The soil was treated at two pH levels (4 and 6). The results showed that the addition of 40-70% peat soil at pH 6 to a polluted soil, and irrigation with processed water accelerated plant growth and phytoextraction efficiency. In the pot experiment, Salix grown in chromium, zinc, copper, nickel and total petroleum hydrocarbons -contaminated field soil for 141 days were unaffected by the contaminated soil and took up excess nutrients from the soil and water. Total mean chromium concentration in the plant organs ranged from 17.05 to 250.45 mg kg -1 , mean zinc concentration ranged from 142.32 to 1616.59 mg kg -1 , mean copper concentration ranged from 12.11 to 223.74 mg kg -1 and mean nickel concentration ranged from 10.11 to 75.90 mg kg -1 . Mean chromium concentration in the plant organs ranged from 46 to 94%, mean zinc concentration ranged from 44 to 76%, mean copper concentration ranged from 19 to 54% and mean nickel concentration ranged from 8 to 21% across all treatments. Under the different treatments, chromium was taken up by Salix in the largest quantities, followed by zinc, copper and nickel respectively. Salix also produced a moderate reduction in total petroleum total petroleum hydrocarbons in the polluted soil. The results from the pot experiment suggest that Salix schwerinii has the potential to accumulate significant amounts of chromium, zinc, copper and nickel. However, long term research is needed to verify the phytoextraction abilities of Salix observed in the pot experiment. Copyright © 2016 Elsevier Ltd. All rights reserved.

Impacts of bromine and iodine chemistry on tropospheric OH and HO2: comparing observations with box and global model perspectives

NASA Astrophysics Data System (ADS)

Stone, Daniel; Sherwen, Tomás; Evans, Mathew J.; Vaughan, Stewart; Ingham, Trevor; Whalley, Lisa K.; Edwards, Peter M.; Read, Katie A.; Lee, James D.; Moller, Sarah J.; Carpenter, Lucy J.; Lewis, Alastair C.; Heard, Dwayne E.

2018-03-01

The chemistry of the halogen species bromine and iodine has a range of impacts on tropospheric composition, and can affect oxidising capacity in a number of ways. However, recent studies disagree on the overall sign of the impacts of halogens on the oxidising capacity of the troposphere. We present simulations of OH and HO2 radicals for comparison with observations made in the remote tropical ocean boundary layer during the Seasonal Oxidant Study at the Cape Verde Atmospheric Observatory in 2009. We use both a constrained box model, using detailed chemistry derived from the Master Chemical Mechanism (v3.2), and the three-dimensional global chemistry transport model GEOS-Chem. Both model approaches reproduce the diurnal trends in OH and HO2. Absolute observed concentrations are well reproduced by the box model but are overpredicted by the global model, potentially owing to incomplete consideration of oceanic sourced radical sinks. The two models, however, differ in the impacts of halogen chemistry. In the box model, halogen chemistry acts to increase OH concentrations (by 9.8 % at midday at the Cape Verde Atmospheric Observatory), while the global model exhibits a small increase in OH at the Cape Verde Atmospheric Observatory (by 0.6 % at midday) but overall shows a decrease in the global annual mass-weighted mean OH of 4.5 %. These differences reflect the variety of timescales through which the halogens impact the chemical system. On short timescales, photolysis of HOBr and HOI, produced by reactions of HO2 with BrO and IO, respectively, increases the OH concentration. On longer timescales, halogen-catalysed ozone destruction cycles lead to lower primary production of OH radicals through ozone photolysis, and thus to lower OH concentrations. The global model includes more of the longer timescale responses than the constrained box model, and overall the global impact of the longer timescale response (reduced primary production due to lower O3 concentrations) overwhelms the shorter timescale response (enhanced cycling from HO2 to OH), and thus the global OH concentration decreases. The Earth system contains many such responses on a large range of timescales. This work highlights the care that needs to be taken to understand the full impact of any one process on the system as a whole.

Crystal chemistry of pyrochlore from the Mesozoic Panda Hill carbonatite deposit, western Tanzania

NASA Astrophysics Data System (ADS)

Boniface, Nelson

2017-02-01

The Mesozoic Panda Hill carbonatite deposit in western Tanzania hosts pyrochlore, an ore and source of niobium. This study was conducted to establish the contents of radioactive elements (uranium and thorium) in pyrochlore along with the concentration of niobium in the ore. The pyrochlore is mainly hosted in sövite and is structurally controlled by NW-SE (SW dipping) or NE-SW (NW dipping) magmatic flow bands with dip angles of between 60° and 90°. Higher concentrations of pyrochlore are associated with magnetite, apatite and/or phlogopite rich flow bands. Electron microprobe analyses on single crystals of pyrochlore yield very low UO2 concentrations that range between 0 and 0.09 wt% (equivalent to 0 atoms per formula unit: a.p.f.u.) and ThO2 between 0.55 and 1.05 wt% (equivalent to 0.1 a.p.f.u.). The analyses reveal high concentrations of Nb2O5 (ranging between 57.13 and 65.50 wt%, equivalent to a.p.f.u. ranging between 1.33 and 1.43) and therefore the Panda Hill Nb-oxide is classified as pyrochlore sensu stricto. These data point to a non radioactive pyrochlore and a deposit rich in Nb at Panda Hill. The Panda Hill pyrochlore has low concentrations of REEs as displayed by La2O3 that range between 0.10 and 0.49 wt% (equivalent to a.p.f.u. ranging between 0 and 0.01) and Ce2O3 ranging between 0.86 and 1.80 wt% (equivalent to a.p.f.u. ranging between 0.02 and 0.03), Pr2O3 concentrations range between 0 and 0.23 wt% (equivalent to 0 a.p.f.u.), and Y2O3 is 0 wt% (equivalent to 0 a.p.f.u.). The abundance of the REEs in pyroclore at the Panda Hill Carbonatite deposit is of no economic significance.

Ecological role of reindeer summer browsing in the mountain birch (Betula pubescens ssp. czerepanovii) forests: effects on plant defense, litter decomposition, and soil nutrient cycling.

PubMed

Stark, Sari; Julkunen-Tiitto, Riitta; Kumpula, Jouko

2007-03-01

Mammalian herbivores commonly alter the concentrations of secondary compounds in plants and, by this mechanism, have indirect effects on litter decomposition and soil carbon and nutrient cycling. In northernmost Fennoscandia, the subarctic mountain birch (Betula pubescens ssp. czerepanovii) forests are important pasture for the semidomestic reindeer (Rangifer tarandus). In the summer ranges, mountain birches are intensively browsed, whereas in the winter ranges, reindeer feed on ground lichens, and the mountain birches remain intact. We analyzed the effect of summer browsing on the concentrations of secondary substances, litter decomposition, and soil nutrient pools in areas that had been separated as summer or winter ranges for at least 20 years, and we predicted that summer browsing may reduce levels of secondary compounds in the mountain birch and, by this mechanism, have an indirect effect on the decomposition of mountain birch leaf litter and soil nutrient cycling. The effect of browsing on the concentration of secondary substances in the mountain birch leaves varied between different years and management districts, but in some cases, the concentration of condensed tannins was lower in the summer than in the winter ranges. In a reciprocal litter decomposition trial, both litter origin and emplacement significantly affected the litter decomposition rate. Decomposition rates were faster for the litter originating from and placed into the summer range. Soil inorganic nitrogen (N) concentrations were higher in the summer than in the winter ranges, which indicates that reindeer summer browsing may enhance the soil nutrient cycling. There was a tight inverse relationship between soil N and foliar tannin concentrations in the winter range but not in the summer range. This suggests that in these strongly nutrient-limited ecosystems, soil N availability regulates the patterns of resource allocation to condensed tannins in the absence but not in the presence of browsing.

The effect of pasteurization on transforming growth factor alpha and transforming growth factor beta 2 concentrations in human milk.

PubMed

McPherson, R J; Wagner, C L

2001-01-01

Transforming growth factor alpha (TGF-alpha) and beta 2 (TGF-beta2) are present in human milk and are involved in growth differentiation and repair of neonatal intestinal epithelia. Heat treatment at 56 degrees C has been shown effective for providing safe banked donor milk, with good retention of other biologically active factors. The purpose of our study was to determine the effect of heat sterilization on TGF-alpha and TGF-beta2 concentrations in human milk. Twenty milk samples were collected from 20 lactating mothers in polypropylene containers and frozen at -20 degrees C for transport or storage. Before heat treatment by holder pasteurization, the frozen milk was thawed and divided into 1-mL aliquots. All samples were heated in an accurately regulated water bath until a holding temperature was achieved, then held for 30 minutes using constant agitation. Holding temperature ranged from 56.5 degrees C to 56.9 degrees C. The milk was then stored at 4 degrees C overnight for analysis the following day. The concentration of TGF-alpha was measured by radioimmunoassay. Mean concentration +/- SD of TGF-alpha in raw milk samples was 119+/-50 pg/mL, range 57 to 234. The mean concentration +/- SD of TGF-alpha in heat treated samples was 113+/-50 pg/mL, range 51 to 227. TGF-alpha concentration was minimally affected by pasteurization, with an overall loss of 6.1%. Of 19 samples, 4 had increased and 15 had decreased concentrations after pasteurization (mean percent SEM: 94%+/-7% of raw milk, range 72%+/-107%). The concentration of acid-activated TGF-beta2 was measured by enzyme-linked immunosorbent assay. Mean concentration +/- SD of TGF-beta2 in raw milk samples was 5624+/-5038 pg/mL, range 195 to 15480. The mean concentration +/- SD of TGF-beta2 in heat-treated samples was 5073+/-4646 pg/mL, range 181 to 15140. TGF-beta2 survived with relatively little loss (0.6%): of 18 samples, 11 had increased and 7 had decreased concentrations after pasteurization (mean percent +/- SEM: 99.4+/-6.7% of raw milk, range 79%-120%). In conclusion, both TGF-alpha and TGF-beta2 were well-preserved in whole milk after holder pasteurization at 56.5 degrees C. The relative increase in growth factor concentration in some of the samples may be attributable to the release of that factor from the cellular and/or fat compartments into the aqueous fraction of human milk. These findings have implications regarding use of donor milk as an alternate source of growth factors and cytokines for the newborn gut when mother's milk is unavailable.

Methyl sterol and cyclopropane fatty acid composition of Methylococcus capsulatus grown at low oxygen tensions

NASA Technical Reports Server (NTRS)

Jahnke, L. L.; Nichols, P. D.

1986-01-01

The sterol and fatty acid concentrations for M. capsulatus grown in fed-batch cultures over a wide range of oxygen tensions (0.1-10.6 percent) and at a constant methane level are evaluated. The analyses reveal that the biomass decreases as oxygen levels are lowered; the sterol concentration increases when the oxygen range is between 0.5-1.1 percent and decreases when the oxygen range is below 0.5 percent; and the amount of monounsaturated C16 decreases and the concentration of cyclopropane fatty acids increases after oxygen is reduced. It is noted that growth and membrane synthesis occur at low oxygen concentrations and that the synthesis of membrane lipids responds to growth conditions.

A novel instrumentation circuit for electrochemical measurements.

PubMed

Yin, Li-Te; Wang, Hung-Yu; Lin, Yang-Chiuan; Huang, Wen-Chung

2012-01-01

In this paper, a novel signal processing circuit which can be used for the measurement of H(+) ion and urea concentration is presented. A potentiometric method is used to detect the concentrations of H(+) ions and urea by using H(+) ion-selective electrodes and urea electrodes, respectively. The experimental data shows that this measuring structure has a linear pH response for the concentration range within pH 2 and 12, and the dynamic range for urea concentration measurement is in the range of 0.25 to 64 mg/dL. The designed instrumentation circuit possesses a calibration function and it can be applied to different sensing electrodes for electrochemical analysis. It possesses the advantageous properties of being multi-purpose, easy calibration and low cost.

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

PubMed

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

2014-01-01

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

Extended range chemical sensing apparatus

DOEpatents

Hughes, R.C.; Schubert, W.K.

1994-01-18

An apparatus is described for sensing chemicals over extended range of concentrations. In particular, first and second sensors each having separate, but overlapping ranges for sensing concentrations of hydrogen are provided. Preferably, the first sensor is a MOS solid state device wherein the metal electrode or gate is a nickel alloy. The second sensor is a chemiresistor comprising a nickel alloy. 6 figures.

[Pollutants produced in municipal refuse container during transfer process].

PubMed

Wang, Xiao-Yuan; Liu, Yin-Hua; Wang, Fei; Huang, Chang-Ying; Lu, Feng; Xie, Bing

2014-05-01

The generation and variation of the secondary pollutants in containers during seasons of a year were investigated in a municipal refuse transfer station of Shanghai. The results showed that the primary odors, the concentration of H2S was in a range of 0.3-10.3 mg.m-3, CH4 was in a range of 0.02% -2.97% and NH3 was in a range of 0.7-4.5 mg m-3, and their concentrations all reached the peak in the summer. The pH of the leachate was in a range of 5.4-6. 3, COD was 41 633-84 060 mgL- 1, and BOD, was 18 116-34 130 mg.L , the concentration of pollutants were all higher in winter than that in summer. The ammonia concentration of leachate was in a range of 537-1222 mg.L'', while the TP fluctuated acutely in a range of 17.98-296 mg L-1, exhibiting the relationship with seasonal variation. Extreme temperatures especially the high temperature in summer significantly affected air pollution producing, which indicated that containers should be kept against high temperature exposure and long residence time in order to prevent flammable gases and other pollutants generated largely.

Physical and chemical limnology of Ides Cove near Rochester, New York, 1970-1982

USGS Publications Warehouse

Bubeck, R.C.; Staubitz, W.W.; Weidemann, A.D.; Spittal, L.P.

1995-01-01

Ides Cove is a small embayment on the western shore of Irondequoit Bay near Rochester, N.Y. In 1982, alum was applied to the cove to seal the bottom sediments and thereby decrease nutrient fluxes in an effort to assess the applicability of this technique to Irondequoit Bay. Published data were used to develop a baseline analysis of the chemical and physical limnology of Ides Cove prior to the alum treatment and to provide a basis for comparison and evaluation of post-treatment data. The baseline analysis also enables evaluation of trends in the nutrient status and mixing patterns in Ides Cove since the decrease of sewage inflows and use of road salt in the Irondequoit Bay and Ides Cove drainage basins during 1970-82. Data from 1970-72 and 1979-82 were used to construct partial and full-year depth profiles of several physical properties and chemical constituents of water in the cove; comparison of these profiles indicates a significant improvement in water quality between 1970 and 1982. The diversion of sewage out of the Irondequoit Creek drainage basin in the late 1970's resulted in an 80-percent decrease in total phosphate concentration and a 50- to 60-percent decrease in nitrogen (nitrate and ammonia) concentration in the cove. Indications of decreased primary productivity are associated with these lowered nutrient concentrations. Summer Secchi-disk transparency increased from 0.6 m (meters) in 1970-72 to 1.2 m in 1980-82; peak epilimnetic dissolved oxygen levels decreased from a range of 22 to 28 mg/L (milligrams per liter) to a range of 16 to 20 mg/L; and peak epilimnetic pH decreased from greater than 9.4 to between 8.8 and 9.0. The decrease in the use of road salt in the Irondequoit basin beginning in 1974 resulted in a decrease in chloride concentration and gradient (difference between the surface and bottom con- centration). The maximum annual chloride concentration in the epilimnion decreased from the 210-to-225-mg/L range in the spring of 1971-72 to the 140-to-l50-mg/L range in the spring of 1980-82, and the gradient between the hypolimnion and epilimnion during the spring decreased from the 80- to 160-mg/L range in 1971-72 to the O- to 90-mg/L range in 1980-82. Specific conductance values decreased similarly and indicate a comparable decrease in the density gradient from 1970-72 to 1980-82. The decrease in the density gradient resulted in an increase in the depth and duration of mixing in both the spring and fall of 1980-82, as illustrated by the profiles of physical properties, including temperature and specific conductance, and of chemical properties and constituents, including pH, alkalinity, dissolved oxygen, chloride, silica, and several species of nitrogen, phosphorus, and sulfur. These data indicate that Ides Cove, which was described as marginally meromictic in the early 1970's, had evolved by the early 1980's into a spring meromictic water body that underwent complete mixing in the fall and was approaching a consistent dimictic condition with spring and fall mixing. Thus, water quality and mixing patterns of the cove improved with the removal of sewage and the decrease in the use of road salt.

Distributions of polycyclic aromatic hydrocarbons and alkylated polycyclic aromatic hydrocarbons in Osaka Bay, Japan.

PubMed

Miki, Shizuho; Uno, Seiichi; Ito, Kazuki; Koyama, Jiro; Tanaka, Hiroyuki

2014-08-30

Contaminations in sediments by polycyclic aromatic hydrocarbons (PAHs) and alkylated PAHs were investigated at 44 sites in Osaka Bay, Japan. Concentrations of total PAHs and alkylated PAHs were in the range 6.40-7800 ng/g dry weights and 13.7-1700 ng/g dry weights, respectively. The PAH concentrations tended to be higher along the shoreline in the vicinities of big ports, industrialized areas, and densely populated regions such as the cities of Osaka and Kobe. The major sources appeared to be pyrogenic or both pyrogenic and petrogenic at most of the sites. PAH concentrations were remarkably high at a site near Kobe, where the concentrations of dibenzo(a,h)anthracene and benzo(g,h,i)perylene exceeded the effects-range-medium concentration and eight PAHs were above the corresponding effects-range-low concentrations. Those PAHs may have been derived from the great fire associated with the large earthquake in 1995. Copyright © 2014 Elsevier Ltd. All rights reserved.

Determination of acetone and methyl ethyl ketone in water

USGS Publications Warehouse

Tai, D.Y.

1978-01-01

Analytical procedures for the determination of acetone and methyl ethyl ketone in water samples were developed. Concentrations in the milligram-per-liter range were determined by injecting an aqueous sample into the analysis system through an injection port, trapping the organics on Tenax-GC at room temperature, and thermally desorbing the organics into a gas chromatograph with a flame ionization detector for analysis. Concentrations in the microgram-per-liter range were determined by sweeping the headspace vapors over a water sample at 50C, trapping on Tenax-GC, and thermally desorbing the organics into the gas chromatograph. The precision for two operators of the milligram-per-liter concentration procedure, expressed as the coefficient of variation, was generally less than 2 percent for concentrations ranging from 16 to 160 milligrams per liter. The precision from two operators of the microgram-per-liter concentration procedure was between 2 and 4 percent for concentrations of 20 and 60 micrograms per liter. (Woodard-USGS)

Nutrient, sediment, and pesticide data collected at four small agricultural basins in the Beaver Creek watershed, West Tennessee, 1990-1995

USGS Publications Warehouse

Williams, Shannon D.; Harris, Robin M.

1996-01-01

In 1989, the U.S. Geological Survey began a cooperative study with the Tennessee Department of Agriculture to assess the impact of agricultural activities on water quality in the Beaver Creek watershed in West Tennessee. Quantification of the transport of nutrients, sediment, and pesticides from agricultural fields was one of the objectives of the study. This report presents nutrient, sediment, and pesticide data collected during selected storm events from 1990 through 1995 at four relatively small, agricultural basins (28 to 422 acres) in the Beaver Creek watershed. Approximately 3,000 water samples (500 to 1,000 at each site) were analyzed for nitrogen and phosphorus species. Total nitrogen (N) concentrations ranged from 0.2 to 41.2 milligrams per liter (mg/L). Median concentrations for samples from each site ranged from 2.0 to 2.7 mg/L for total nitrogen, 1.2 to 1.9 mg/L for organic nitrogen, 0.05 to 0.14 mg/L for ammonia (measured as N), and 0.2 to 0.8 mg/L for nitrate plus nitrite (measured as N). Total phosphorus (P) concentrations ranged from 0.03 to 16.0 mg/L. Median concentrations for samples from each site ranged from 0.80 to 1.2 mg/L for total phosphorus and 0.15 to 0.72 for orthophosphate (measured as P). Approximately 6,000 water samples (1,300 to 1,800 at each site) were analyzed for suspended sediment. Suspended-sediment concentrations ranged from 8.0 to 98,353 mg/L. Concentrations exceeded 1,000 mg/L in 33 percent of the samples collected and exceeded 10,000 mg/L in 6 percent of the samples. Median concentrations ranged from 347 to 713 mg/L at the four sites. Several herbicides and insecticides were detected in water samples. Maximum concentrations detected were 37 micrograms per liter for metolachlor, 3.2 for trifluralin, 150 for fluometuron, and 430 for aldicarb. Aldicarb metabolites were also detected in several samples. The maximum aldicarb sulfoxide and aldicarb sulfone concentrations detected were 68.4 and 14.3 micrograms per liter, respectively.

Investigation of absolute and relative response for three different liquid chromatography/tandem mass spectrometry systems; the impact of ionization and detection saturation.

PubMed

Nilsson, Lars B; Skansen, Patrik

2012-06-30

The investigations in this article were triggered by two observations in the laboratory; for some liquid chromatography/tandem mass spectrometry (LC/MS/MS) systems it was possible to obtain linear calibration curves for extreme concentration ranges and for some systems seemingly linear calibration curves gave good accuracy at low concentrations only when using a quadratic regression function. The absolute and relative responses were tested for three different LC/MS/MS systems by injecting solutions of a model compound and a stable isotope labeled internal standard. The analyte concentration range for the solutions was 0.00391 to 500 μM (128,000×), giving overload of the chromatographic column at the highest concentrations. The stable isotope labeled internal standard concentration was 0.667 μM in all samples. The absolute response per concentration unit decreased rapidly as higher concentrations were injected. The relative response, the ratio for the analyte peak area to the internal standard peak area, per concentration unit was calculated. For system 1, the ionization process was found to limit the response and the relative response per concentration unit was constant. For systems 2 and 3, the ion detection process was the limiting factor resulting in decreasing relative response at increasing concentrations. For systems behaving like system 1, simple linear regression can be used for any concentration range while, for systems behaving like systems 2 and 3, non-linear regression is recommended for all concentration ranges. Another consequence is that the ionization capacity limited systems will be insensitive to matrix ion suppression when an ideal internal standard is used while the detection capacity limited systems are at risk of giving erroneous results at high concentrations if the matrix ion suppression varies for different samples in a run. Copyright © 2012 John Wiley & Sons, Ltd.

Analysis of additives in dairy products by liquid chromatography coupled to quadrupole-orbitrap mass spectrometry.

PubMed

Jia, Wei; Ling, Yun; Lin, Yuanhui; Chang, James; Chu, Xiaogang

2014-04-04

A new method combining QuEChERS with ultrahigh-performance liquid chromatography and electrospray ionization quadrupole Orbitrap high-resolution mass spectrometry (UHPLC/ESI Q-Orbitrap) was developed for the highly accurate and sensitive screening of 43 antioxidants, preservatives and synthetic sweeteners in dairy products. Response surface methodology was employed to optimize a quick, easy, cheap, effective, rugged, and safe (QuEChERS) sample preparation method for the determination of 42 different analytes in dairy products for the first time. After optimization, the maximum predicted recovery was 99.33% rate for aspartame under the optimized conditions of 10 mL acetionitrile, 1.52 g sodium acetate, 410 mg PSA and 404 mgC18. For the matrices studied, the recovery rates of the other 42 compounds ranged from 89.4% to 108.2%, with coefficient of variation <6.4%. UHPLC/ESI Q-Orbitrap Mass full scan mode acquired full MS data was used to identify and quantify additives, and data-dependent scan mode obtained fragment ion spectra for confirmation. The mass accuracy typically obtained is routinely better than 1.5ppm, and only need to calibrate once a week. The 43 compounds behave dynamic in the range 0.001-1000 μg kg(-1) concentration, with correlation coefficient >0.999. The limits of detection for the analytes are in the range 0.0001-3.6 μg kg(-1). This method has been successfully applied on screening of antioxidants, preservatives and synthetic sweeteners in commercial dairy product samples, and it is very useful for fast screening of different food additives. Copyright © 2014 Elsevier B.V. All rights reserved.

Non-Native Metal Ion Reveals the Role of Electrostatics in Synaptotagmin 1-Membrane Interactions.

PubMed

Katti, Sachin; Nyenhuis, Sarah B; Her, Bin; Srivastava, Atul K; Taylor, Alexander B; Hart, P John; Cafiso, David S; Igumenova, Tatyana I

2017-06-27

C2 domains are independently folded modules that often target their host proteins to anionic membranes in a Ca 2+ -dependent manner. In these cases, membrane association is triggered by Ca 2+ binding to the negatively charged loop region of the C2 domain. Here, we used a non-native metal ion, Cd 2+ , in lieu of Ca 2+ to gain insight into the contributions made by long-range Coulombic interactions and direct metal ion-lipid bridging to membrane binding. Using X-ray crystallography, NMR, Förster resonance energy transfer, and vesicle cosedimentation assays, we demonstrate that, although Cd 2+ binds to the loop region of C2A/B domains of synaptotagmin 1 with high affinity, long-range Coulombic interactions are too weak to support membrane binding of individual domains. We attribute this behavior to two factors: the stoichiometry of Cd 2+ binding to the loop regions of the C2A and C2B domains and the impaired ability of Cd 2+ to directly coordinate the lipids. In contrast, electron paramagnetic resonance experiments revealed that Cd 2+ does support membrane binding of the C2 domains in full-length synaptotagmin 1, where the high local lipid concentrations that result from membrane tethering can partially compensate for lack of a full complement of divalent metal ions and specific lipid coordination in Cd 2+ -complexed C2A/B domains. Our data suggest that long-range Coulombic interactions alone can drive the initial association of C2A/B with anionic membranes and that Ca 2+ further augments membrane binding by the formation of metal ion-lipid coordination bonds and additional Ca 2+ ion binding to the C2 domain loop regions.

Accurate mass replacement method for the sediment concentration measurement with a constant volume container

NASA Astrophysics Data System (ADS)

Ban, Yunyun; Chen, Tianqin; Yan, Jun; Lei, Tingwu

2017-04-01

The measurement of sediment concentration in water is of great importance in soil erosion research and soil and water loss monitoring systems. The traditional weighing method has long been the foundation of all the other measuring methods and instrument calibration. The development of a new method to replace the traditional oven-drying method is of interest in research and practice for the quick and efficient measurement of sediment concentration, especially field measurements. A new method is advanced in this study for accurately measuring the sediment concentration based on the accurate measurement of the mass of the sediment-water mixture in the confined constant volume container (CVC). A sediment-laden water sample is put into the CVC to determine its mass before the CVC is filled with water and weighed again for the total mass of the water and sediments in the container. The known volume of the CVC, the mass of sediment-laden water, and sediment particle density are used to calculate the mass of water, which is replaced by sediments, therefore sediment concentration of the sample is calculated. The influence of water temperature was corrected by measuring water density to determine the temperature of water before measurements were conducted. The CVC was used to eliminate the surface tension effect so as to obtain the accurate volume of water and sediment mixture. Experimental results showed that the method was capable of measuring the sediment concentration from 0.5 up to 1200 kg m-3. A good liner relationship existed between the designed and measured sediment concentrations with all the coefficients of determination greater than 0.999 and the averaged relative error less than 0.2%. All of these seem to indicate that the new method is capable of measuring a full range of sediment concentration above 0.5 kg m-3 to replace the traditional oven-drying method as a standard method for evaluating and calibrating other methods.

Evaluation of aqueous and ethanol extract of bioactive medicinal plant, Cassia didymobotrya (Fresenius) Irwin & Barneby against immature stages of filarial vector, Culex quinquefasciatus Say (Diptera: Culicidae).

PubMed

Nagappan, Raja

2012-09-01

To evaluate aqueous and ethanol extract of Cassia didymobotrya leaves against immature stages of Culex quinquefasciatus. The mortality rate of immature mosquitoes was tested in wide and narrow range concentration of the plant extract based on WHO standard protocol. The wide range concentration tested in the present study was 10 000, 1 000, 100, 10 and 1 mg/L and narrow range concentration was 50, 100, 150, 200 and 250 mg/L. 2nd instar larvae exposed to 100 mg/L and above concentration of ethanol extract showed 100% mortality. Remaining stages such as 3rd, 4th and pupa, 100% mortality was observed at 1 000 mg/L and above concentration after 24 h exposure period. In aqueous extract all the stages 100% mortality was recorded at 1 000 mg/L and above concentration. In narrow range concentration 2nd instar larvae 100% mortality was observed at 150 mg/L and above concentration of ethanol extract. The remaining stages 100% mortality was recorded at 250 mg/L. In aqueous extract all the tested immature stages 100% mortality was observed at 250 mg/L concentration after 24 h exposure period. The results clearly indicate that the rate of mortality was based dose of the plant extract and stage of the mosquitoes. From this study it is confirmed and concluded that Cassia didymobotrya is having active principle which is responsible for controlling Culex quinquefasciatus. The isolation of bioactive molecules and development of simple formulation technique is important for large scale implementation.

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

PubMed

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

2017-05-03

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

Perils of categorical thinking: "Oxic/anoxic" conceptual model in environmental remediation

USGS Publications Warehouse

Bradley, Paul M.

2012-01-01

Given ambient atmospheric oxygen concentrations of about 21 percent (by volume), the lower limit for reliable quantitation of dissolved oxygen concentrations in groundwater samples is in the range of 0.1–0.5 mg/L. Frameworks for assessing in situ redox condition are often applied using a simple two-category (oxic/anoxic) model of oxygen condition. The "oxic" category defines the environmental range in which dissolved oxygen concentrations are clearly expected to impact contaminant biodegradation, either by supporting aerobic biodegradation of electron-donor contaminants like petroleum hydrocarbons or by inhibiting anaerobic biodegradation of electron-acceptor contaminants like chloroethenes. The tendency to label the second category "anoxic" leads to an invalid assumption that oxygen is insignificant when, in fact, the dissolved oxygen concentration is less than detection but otherwise unknown. Expressing dissolved oxygen concentrations as numbers of molecules per volume, dissolved oxygen concentrations that fall below the 0.1 mg/L field detection limit range from 1 to 1017 molecules/L. In light of recent demonstrations of substantial oxygen-linked biodegradation of chloroethene contaminants at dissolved oxygen concentrations well below the 0.1–0.5 mg/L field detection limit, characterizing "less than detection" oxygen concentrations as "insignificant" is invalid.

Emission of polybrominated diphenyl ethers (PBDEs) in use of electric/electronic equipment and recycling of e-waste in Korea.

PubMed

Park, Jong-Eun; Kang, Young-Yeul; Kim, Woo-Il; Jeon, Tae-Wan; Shin, Sun-Kyoung; Jeong, Mi-Jeong; Kim, Jong-Guk

2014-02-01

The emission rates of polybrominated diphenyl ethers (PBDEs) from electric/electronic products during their use and disposal were estimated. E-wastes, including televisions and refrigerators, gathered at recycling centers were also analyzed to estimate their emissions. The average concentrations of PBDEs in TV rear covers produced before and after the year 2000 were 145,027 mg/kg and 14,049 mg/kg, respectively. The PBDEs concentration in TV front covers was lower than the concentration in TV rear covers. The concentration in the components of the refrigerator samples ranged from ND to 445 mg/kg. We estimated the atmospheric emissions of PBDEs based on the concentrations. The annual emissions from TV rear covers produced before 2000 were calculated to be approximately 162.1 kg and after 2000, the annual emissions were 18.7 kg. Refrigerators showed the lowest annual emissions of PBDEs (0.7 kg). The atmospheric concentrations were also measured to calculate emissions generated during the recycling process. The highest concentration was 16.86 ng/m(3) emitted from the TV sets during the dismantling process. The concentrations of PBDEs generated in the plastic processing field ranged from 2.05 to 5.43 ng/m(3) depending on the products, and ambient air in open-air yards showed concentrations in the range of 0.32 to 5.55 ng/m(3). Emission factors for the recycling process were calculated using the observed concentrations. The estimated emissions according to the emission factors ranged from 0.3×10(-1) to 90.3 kg/year for open-air yards and from 0.1×10(-1) to 292.7 kg/year for the dismantling and crushing processes of TV set, depending on the production year. © 2013 Elsevier B.V. All rights reserved.

Selenium in soil, water, sediment, and biota of the lower Sun River area, West-Central Montana

USGS Publications Warehouse

Nimick, David A.; Lambing, John H.; Palawski, Donald U.

1993-01-01

A U.S. Department of the Interior study started in 1990 examined the source, movement, fate, and possible biological effects of selenium associated with irrigation drainage from the Sun River Irrigation Project in west-central Montana. Concentrations of total selenium in soil samples ranged from 0.1 to 8.5 micrograms per gram; the maximum concentrations were measured in nonirrigated areas overlying geologic formations containing seleniferous shale. In irrigated areas, concentrations of dissolved selenium in ground water flowing toward Freezeout Lake ranged from less than 1 to 18 micrograms per liter (??g/L) in terrace gravel and from 1 to 190 ??g/L in glacial deposits derived from seleniferous shale. Concentrations of total selenium ranged from less than 1 to 180 ??g/L in surface irrigation drainage, and from less than 1 to 1,000 ??g/L in natural flows from nonirrigated land. Selenium concentrations in water from lakes generally were less than the aquatic-life criterion for chronic toxicity. The range of selenium concentrations in bottom sediment of lakes was similar to that of local soils. However, biological samples indicate that selenium is accumulating through the aquatic food chain. Selenium concentrations indicative of biological risk were exceeded in at least 80 percent of the freshwater-invertebrate, bird-egg, and bird-liver samples collected from all wetland sites.

Reduction of ammonia and volatile organic compounds from food waste-composting facilities using a novel anti-clogging biofilter system.

PubMed

Ryu, Hee Wook; Cho, Kyung-Suk; Lee, Tae-Ho

2011-04-01

The performance of a pilot-scale anti-clogging biofilter system (ABS) was evaluated over a period of 125days for treating ammonia and volatile organic compounds emitted from a full-scale food waste-composting facility. The pilot-scale ABS was designed to intermittently and automatically remove excess biomass using an agitator. When the pressure drop in the polyurethane filter bed was increased to a set point (50 mm H(2)O m(-1)), due to excess biomass acclimation, the agitator automatically worked by the differential pressure switch, without biofilter shutdown. A high removal efficiency (97-99%) was stably maintained for the 125 days after an acclimation period of 1 week, even thought the inlet gas concentrations fluctuated from 0.16 to 0.55 g m(-3). Due the intermittent automatic agitation of the filter bed, the biomass concentration and pressure drop in the biofilter were maintained within the ranges of 1.1-2.0 g-DCW g PU(-1) and below 50 mm H(2)O m(-1), respectively. Copyright © 2011 Elsevier Ltd. All rights reserved.

Analysis of Protein Interactions with Picomolar Binding Affinity by Fluorescence-Detected Sedimentation Velocity

PubMed Central

2014-01-01

The study of high-affinity protein interactions with equilibrium dissociation constants (KD) in the picomolar range is of significant interest in many fields, but the characterization of stoichiometry and free energy of such high-affinity binding can be far from trivial. Analytical ultracentrifugation has long been considered a gold standard in the study of protein interactions but is typically applied to systems with micromolar KD. Here we present a new approach for the study of high-affinity interactions using fluorescence detected sedimentation velocity analytical ultracentrifugation (FDS-SV). Taking full advantage of the large data sets in FDS-SV by direct boundary modeling with sedimentation coefficient distributions c(s), we demonstrate detection and hydrodynamic resolution of protein complexes at low picomolar concentrations. We show how this permits the characterization of the antibody–antigen interactions with low picomolar binding constants, 2 orders of magnitude lower than previously achieved. The strongly size-dependent separation and quantitation by concentration, size, and shape of free and complex species in free solution by FDS-SV has significant potential for studying high-affinity multistep and multicomponent protein assemblies. PMID:24552356

The Effect of Small Additions of Carbon Nanotubes on the Mechanical Properties of Epoxy Polymers under Static and Dynamic Loads

NASA Astrophysics Data System (ADS)

Tarasov, A. E.; Badamshina, E. R.; Anokhin, D. V.; Razorenov, S. V.; Vakorina, G. S.

2018-01-01

The results of measurements of the mechanical characteristics of cured epoxy composites containing small and ultrasmall additions of single-walled carbon nanotubes in the concentration range from 0 to 0.133 wt % under static and dynamic loads are presented. Static measurements of strength characteristics have been carried out under standard test conditions. Measurements of the Hugoniot elastic limit and spall strength were performed under a shock wave loading of the samples at a deformation rate of (0.8-1.5) ß 105 s-1 before the fracture using explosive devices by recording and subsequent analyzing the evolution of the full wave profiles. It has been shown that agglomerates of nanotubes present in the structure of the composites after curing cause a significant scatter of the measured strength parameters, both in the static and in the dynamic test modes. However, the effects of carbon nanotube additions in the studied concentration interval on the physical and mechanical characteristics of the parameters were not revealed for both types of loading.

Optical ammonia gas sensor based on a porous silicon rugate filter coated with polymer-supported dye.

PubMed

Shang, Yunling; Wang, Xiaobo; Xu, Erchao; Tong, Changlun; Wu, Jianmin

2011-01-24

An ammonia gas sensor chip was prepared by coating an electrochemically-etched porous Si rugate filter with a chitosan film that is crosslinked by glycidoxypropyltrimethoxysilane (GPTMS). The bromothylmol blue (BTB), a pH indicator, was loaded in the film as ammonia-sensing molecules. White light reflected from the porous Si has a narrow bandwidth spectrum with a peak at 610 nm. Monitoring reflective optical intensity at the peak position allows for direct, real-time observation of changes in the concentration of ammonia gas in air samples. The reflective optical intensity decreased linearly with increasing concentrations of ammonia gas over the range of 0-100 ppm. The lowest detection limit was 0.5 ppm for ammonia gas. At optimum conditions, the full response time of the ammonia gas sensor was less than 15s. The sensor chip also exhibited a good long-term stability over 1 year. Therefore, the simple sensor design has potential application in miniaturized optical measurement for online ammonia gas detection. Copyright © 2010 Elsevier B.V. All rights reserved.

Cleaning oil refining drainage waters out of emulsified oil products with thermic treated cedar nut shell

NASA Astrophysics Data System (ADS)

Pyatanova, P. A.; Adeeva, L. N.

2017-08-01

It was elaborated the ability of the sorbent produced by thermic treatment of cedar nut shell to destruct model and real first kind (direct) emulsions in static and dynamic conditions. In static conditions optimal ratio sorbent-emulsion with the original concentration of oil products 800 mg/l was in the range of 2.0 g per 100 ml of emulsion which corresponds to the level of treatment 94.9%. The time of emulsion destruction was 40 minutes. This sorbent is highly active in dynamic processes of oil-contaminated water treatment, the level of treatment 96.0% is being achieved. Full dynamic sorptive capacity of the sorbent is 0.85 g/g. Sorbent based on the thermic treated cedar nut shell can be elaborated as sorptive filter element of local treatment facilities of oil refining and petrochemical processes. After the treatment with this sorbent of drainage waters of oil refinery in dynamic conditions the concentration of oil products became less than mpc on oil products for waste waters coming to biological treatment.

Ultra high performance liquid chromatography-quadrupole-time of flight analysis for the identification and the determination of resveratrol and its metabolites in mouse plasma.

PubMed

Menet, M C; Cottart, C H; Taghi, M; Nivet-Antoine, V; Dargère, D; Vibert, F; Laprévote, O; Beaudeux, J-L

2013-01-25

Resveratrol is a polyphenol that has numerous interesting biological properties, but, per os, it is quickly metabolized. Some of its metabolites are more concentrated than resveratrol, may have greater biological activities, and may act as a kind of store for resveratrol. Thus, to understand the biological impact of resveratrol on a physiological system, it is crucial to simultaneously analyze resveratrol and its metabolites in plasma. This study presents an analytical method based on UHPLC-Q-TOF mass spectrometry for the quantification of resveratrol and of its most common hydrophilic metabolites. The use of (13)C- and D-labeled standards specific to each molecule led to a linear calibration curve on a larger concentration range than described previously. The use of high resolution mass spectrometry in the full scan mode enabled simultaneous identification and quantification of some hydrophilic metabolites not previously described in mice. In addition, UHPLC separation, allowing run times lower than 10 min, can be used in studies that requiring analysis of many samples. Copyright © 2012 Elsevier B.V. All rights reserved.

Error analysis for reducing noisy wide-gap concentric cylinder rheometric data for nonlinear fluids - Theory and applications

NASA Technical Reports Server (NTRS)

Borgia, Andrea; Spera, Frank J.

1990-01-01

This work discusses the propagation of errors for the recovery of the shear rate from wide-gap concentric cylinder viscometric measurements of non-Newtonian fluids. A least-square regression of stress on angular velocity data to a system of arbitrary functions is used to propagate the errors for the series solution to the viscometric flow developed by Krieger and Elrod (1953) and Pawlowski (1953) ('power-law' approximation) and for the first term of the series developed by Krieger (1968). A numerical experiment shows that, for measurements affected by significant errors, the first term of the Krieger-Elrod-Pawlowski series ('infinite radius' approximation) and the power-law approximation may recover the shear rate with equal accuracy as the full Krieger-Elrod-Pawlowski solution. An experiment on a clay slurry indicates that the clay has a larger yield stress at rest than during shearing, and that, for the range of shear rates investigated, a four-parameter constitutive equation approximates reasonably well its rheology. The error analysis presented is useful for studying the rheology of fluids such as particle suspensions, slurries, foams, and magma.

Second Trimester Amniotic Fluid Bisphenol A Concentration is Associated with Decreased Birth Weight in Term Infants

PubMed Central

Pinney, Sara E.; Mesaros, Clementina A.; Snyder, Nathaniel W.; Busch, Christine M.; Xiao, Rui; Aijaz, Sara; Ijaz, Naila; Blair, Ian A.; Manson, Jeanne M.

2016-01-01

Bisphenol A (BPA) is an endocrine disrupting chemical with ubiquitous environmental exposure. Animal studies have demonstrated that in utero BPA exposure leads to increased adult body weight. Our aim was to characterize human fetal BPA exposure by measuring BPA concentration in second trimester amniotic fluid (AF) samples and to study its relationship with birth weight (BW) in full term infants. To achieve these goals, we developed a total BPA assay utilizing derivatization with pentafluorobenzyl followed by analysis with LC-ECAPCI-MS/MS with a limit of detection of 0.08 ng/mL and limit of quantification (LOQ) of 0.25 ng/mL. The mean BW of infants with AF BPA 0.40-2.0 ng/mL was 241.8 grams less than infants with AF BPA less than the LOQ after controlling for covariates (p=0.049). No effect was seen outside this range indicating a non-monotonic effect. Our data suggest that low level BPA exposure in utero decreases BW and needs further study. PMID:27829162

Second-surface silvered glass solar mirrors of very high reflectance

NASA Astrophysics Data System (ADS)

Butel, Guillaume P.; Coughenour, Blake M.; Macleod, H. Angus; Kennedy, Cheryl E.; Olbert, Blain H.; Angel, J. Roger P.

2011-10-01

This paper reports methods developed to maximize the overall reflectance second-surface silvered glass. The reflectance at shorter wavelengths is increased with the aid of a dielectric enhancing layer between the silver and the glass, while at longer wavelengths it is enhanced by use of glass with negligible iron content. The calculated enhancement of reflectance, compared to unenhanced silver on standard low-iron float glass, corresponds to a 4.4% increase in reflectance averaged across the full solar spectrum, appropriate for CSP, and 2.7% for CPV systems using triple junction cells. An experimental reflector incorporating these improvements, of drawn crown glass and a silvered second-surface with dielectric boost, was measured at NREL to have 95.4% solar weighted reflectance. For comparison, non-enhanced, wetsilvered reflectors of the same 4 mm thickness show reflectance ranging from 91.6 - 94.6%, depending on iron content. A potential drawback of using iron-free drawn glass is reduced concentration in high concentration systems because of the inherent surface errors. This effect is largely mitigated for glass shaped by slumping into a concave mold, rather than by bending.

Satiety following intake of potatoes and other carbohydrate test meals.

PubMed

Geliebter, Allan; Lee, Michelle I-Ching; Abdillahi, Mariane; Jones, James

2013-01-01

The study investigated satiation and satiety following intake of starch-rich side dishes representing a range of glycemic indices (GIs). Twelve normal-weight (BMI = 22.4 ± SD 2.0) participants (6 male, 6 female, 22-30 years) received one of four side dishes or white bread (GI reference) in randomized order on five mornings, followed by an ad libitum lunch. Blood draws prior to test meal and during the 2 h before lunch measured plasma glucose and insulin concentrations. GI was calculated from glucose incremental area under the curve (AUC). Hunger, fullness, desire to eat and prospective consumption were rated just before blood draws. No significant difference was found in hunger or fullness AUCs between test meals. Both potato meals yielded lower desire to eat compared to pasta throughout the 2-hour period (p = 0.002). Total lunch energy intake did not differ. No significant correlations were found between test meal GI and ratings of hunger, fullness or energy intake at lunch meal. GI of energy-equivalent test meals did not predict satiety or lunch meal intake. There was evidence of reduced appetite following both potato meals relative to the other carbohydrate side dishes but no differences in subsequent intake. Copyright © 2012 S. Karger AG, Basel.

Calculation and evaluation of sediment effect concentrations for the amphipod Hyalella azteca and the midge Chironomus riparius

USGS Publications Warehouse

Ingersoll, Christopher G.; Haverland, Pamela S.; Brunson, Eric L.; Canfield, Timothy J.; Dwyer, F. James; Henke, Chris; Kemble, Nile E.; Mount, David R.; Fox, Richard G.

1996-01-01

Procedures are described for calculating and evaluating sediment effect concentrations (SECs) using laboratory data on the toxicity of contaminants associated with field-collected sediment to the amphipod Hyalella azteca and the midge Chironomus riparius. SECs are defined as the concentrations of individual contaminants in sediment below which toxicity is rarely observed and above which toxicity is frequently observed. The objective of the present study was to develop SECs to classify toxicity data for Great Lake sediment samples tested with Hyalella azteca and Chironomus riparius. This SEC database included samples from additional sites across the United States in order to make the database as robust as possible. Three types of SECs were calculated from these data: (1) Effect Range Low (ERL) and Effect Range Median (ERM), (2) Threshold Effect Level (TEL) and Probable Effect Level (PEL), and (3) No Effect Concentration (NEC). We were able to calculate SECs primarily for total metals, simultaneously extracted metals, polychlorinated biphenyls (PCBs), and polycyclic aromatic hydrocarbons (PAHs). The ranges of concentrations in sediment were too narrow in our database to adequately evaluate SECs for butyltins, methyl mercury, polychlorinated dioxins and furans, or chlorinated pesticides. About 60 to 80% of the sediment samples in the database are correctly classified as toxic or not toxic depending on type of SEC evaluated. ERMs and ERLs are generally as reliable as paired PELs and TELs at classifying both toxic and non-toxic samples in our database. Reliability of the SECs in terms of correctly classifying sediment samples is similar between ERMs and NECs; however, ERMs minimize Type I error (false positives) relative to ERLs and minimize Type II error (false negatives) relative to NECs. Correct classification of samples can be improved by using only the most reliable individual SECs for chemicals (i.e., those with a higher percentage of correct classification). SECs calculated using sediment concentrations normalized to total organic carbon (TOC) concentrations did not improve the reliability compared to SECs calculated using dry-weight concentrations. The range of TOC concentrations in our database was relatively narrow compared to the ranges of contaminant concentrations. Therefore, normalizing dry-weight concentrations to a relatively narrow range of TOC concentrations had little influence on relative concentra of contaminants among samples. When SECs are used to conduct a preliminary screening to predict the potential for toxicity in the absence of actual toxicity testing, a low number of SEC exceedances should be used to minimize the potential for false negatives; however, the risk of accepting higher false positives is increased.

Calcium and Phosphor Status of Beef Cattle in Upland and Lowland of Jratunseluna River Basin in Central Java

NASA Astrophysics Data System (ADS)

Sutrisno; Subrata, A.; Surahmanto; Christiyanto, M.; Surono; Achmadi, J.; Wahyono, F.; Pangestu, E.

2018-02-01

The study was aimed to obtain information regarding feed given and mineralstatus (Ca, P) in fodder and beef cattle in Jratunseluna river basin. Feed and drinking water given by farmers identified for 14 days and extracted sampling for mineralanalysis, t-test was used to compare mineral status in upland and lowland. Results of the research showed that feed given by farmers were varying. The ratio of forage/concentrates in lowland and upland areas was different, i.e. 67: 33 and 30: 70, respectivelly. Ca content on forage given in upland areas ranged from 0.17 to 0.74%, and concentrates from 0.002 to 0.49%, while Ca content on forage given in lowland areas ranged from 0.33 to 0.52%, and concentrates ranged from 0.38 to 0.49%. P content on forage in upland areas ranged from 0.02 to 0.04%, concentrates ranged from 0.018 to 0.09%,while P content on forage in lowland areas ranged from 0.03 to 0.07%, and concentrates ranged from 0.04 to 0.07% . Ca and P consumption in upland areas were 301.06 and 54.73 g, and 391.92 and 65.70 g in lowland.Caand P content of beef cattle’s hair in upland were 0.14 and 0.01%, while in lowland areas were 0.11 and 0.03%.It can be concluded that Ca and P intakeof beef cattle in Jratunseluna river basin were less and mineral status of Ca and P in marginal condition.

An isotherm-based thermodynamic model of multicomponent aqueous solutions, applicable over the entire concentration range.

PubMed

Dutcher, Cari S; Ge, Xinlei; Wexler, Anthony S; Clegg, Simon L

2013-04-18

In previous studies (Dutcher et al. J. Phys. Chem. C 2011, 115, 16474-16487; 2012, 116, 1850-1864), we derived equations for the Gibbs energy, solvent and solute activities, and solute concentrations in multicomponent liquid mixtures, based upon expressions for adsorption isotherms that include arbitrary numbers of hydration layers on each solute. In this work, the long-range electrostatic interactions that dominate in dilute solutions are added to the Gibbs energy expression, thus extending the range of concentrations for which the model can be used from pure liquid solute(s) to infinite dilution in the solvent, water. An equation for the conversion of the reference state for solute activity coefficients to infinite dilution in water has been derived. A number of simplifications are identified, notably the equivalence of the sorption site parameters r and the stoichiometric coefficients of the solutes, resulting in a reduction in the number of model parameters. Solute concentrations in mixtures conform to a modified Zdanovskii-Stokes-Robinson mixing rule, and solute activity coefficients to a modified McKay-Perring relation, when the effects of the long-range (Debye-Hückel) term in the equations are taken into account. Practical applications of the equations to osmotic and activity coefficients of pure aqueous electrolyte solutions and mixtures show both satisfactory accuracy from low to high concentrations, together with a thermodynamically reasonable extrapolation (beyond the range of measurements) to extreme concentration and to the pure liquid solute(s).

Trends in the short-term release of fission products and actinides to aqueous solution from used CANDU fuels at elevated temperature

NASA Astrophysics Data System (ADS)

Stroes-Gascoyne, S.

1992-08-01

A large number of short-term leaching experiments has been performed to determine fission product and actinide release from used CANDU (CANada Deuterium Uranium) fuels and to establish which factors affect release. Results are reported after30 ± 10 d leaching at 100-150°C under oxidizing (air) or reducing (Ar-3% H 2 or Ar) conditions, in various synthetic groundwaters. Cesium-137 release (0.007-6%) was positively correlated with increases in fuel power, leachant temperature and ionic strength. Strontium-90 release (0.0003-0.3%) generally increased with ionic strength, higher temperature and redox conditions. Actinide and Tc concentrations were compared to ranges calculated with a thermodynamic equilibrium model, that accounts for the uncertain geochemical parameters of a nuclear waste vault by calculating concentration ranges based on 40000 hypothetical cases. Experimental U concentrations (10 -8.5 to 10 -3 mol/kg) were higher than the model range, probably because of higher redox potentials in the experiments. Measured Pu concentrations (10 -12.5 to 10 -7 mol/kg) were at the low end of the calculated range. Americium and Cm concentrations (10 -12.5 to 10 -7 and 10 -15 to 10 -9 mol/kg, respectively) were highest under oxidizing conditions and higher temperatures. Technetium-99 concentrations (10 -5.5 to 10 -10.5 mol/kg) covered a much narrower range than calculated by the model.

A high-resolution full-field range imaging system

NASA Astrophysics Data System (ADS)

Carnegie, D. A.; Cree, M. J.; Dorrington, A. A.

2005-08-01

There exist a number of applications where the range to all objects in a field of view needs to be obtained. Specific examples include obstacle avoidance for autonomous mobile robots, process automation in assembly factories, surface profiling for shape analysis, and surveying. Ranging systems can be typically characterized as being either laser scanning systems where a laser point is sequentially scanned over a scene or a full-field acquisition where the range to every point in the image is simultaneously obtained. The former offers advantages in terms of range resolution, while the latter tend to be faster and involve no moving parts. We present a system for determining the range to any object within a camera's field of view, at the speed of a full-field system and the range resolution of some point laser scans. Initial results obtained have a centimeter range resolution for a 10 second acquisition time. Modifications to the existing system are discussed that should provide faster results with submillimeter resolution.

[Measurements of vancomycin concentrations in the blood - a method of personalization the antibiotic therapy in patients with chronic kidney disease].

PubMed

Pondel, Joanna; Krajewski, Piotr; Królikowska, Natalia; Tobiasz, Aleksandra; Augustyniak-Bartosik, Hanna; Hurkacz, Magdalena

2017-04-21

Therapeutic Drug Monitoring is a recognized method of personalizing treatment, having particular application in patients with chronic kidney disease who have frequent infections, requiring administration of vancomycin. International guidelines indicate the need to adjust the dose of the drug to the state of renal function. The recommended therapeutic ranges of minimum and maximum levels should be achieved in order to increase the effectiveness and safety of treatment. The aim of this study was to evaluate the usefulness of measuring the concentration of vancomycin in patients with chronic kidney disease due to bacterial infection. The study included 96 adult patients with chronic kidney disease of varying severity treated with vancomycin Patients were divided into 3 groups: treated by haemodialysis (hd), after renal transplantations (ktx), do not require renal replacement therapy (nef). In subjects were examined the minimum and maximum concentrations of vancomycin in steady-state and were compared with recommended therapeutic ranges. Statistically significant decrease of inflammatory markers was observed only in patients treated with dialysis. In the other groups not significant changes in values of inflammatory parameters were confirmed. Trough concentrations of vancomycin marked in patients were consistent with the recommendation of EUCAST, but exceeded the value recommended by the manufacturers of the drug. Considering absolute values of the minimum concentrations, only about 50% of patients achieved the therapeutic range (58% for recommendation EUCAST and 36% for the manufacturer's instructions). Peak concentration values indicated in dialyzed patients were below the prescribed range of 20-50 mg/l and averaged 17.7 mg / l. In the other subgroups they were correct. The rating of the absolute values of the peak concentrations of vancomycin also showed that only 46% (64% in the ktx, 30% - hd and 53% - nef) was within the recommended range, while 50% were classified as concentrations of sub-therapeutic (36% in the ktx, 42% of the nef group and 65% in hd). Vancomycin concentrations measured in patients with chronic kidney disease, both minimum and maximum, were not fully comply with the recommended therapeutic ranges, despite the use of doses determined based on a calculation of glomerular filtration rate. This points to the need for particularly careful monitoring of therapy and analysis of antibiotic concentrations to improve the effectiveness and reduce the incidence of undesirable consequences of treatment.

Theory and design of line-to-point focus solar concentrators with tracking secondary optics.

PubMed

Cooper, Thomas; Ambrosetti, Gianluca; Pedretti, Andrea; Steinfeld, Aldo

2013-12-10

The two-stage line-to-point focus solar concentrator with tracking secondary optics is introduced. Its design aims to reduce the cost per m(2) of collecting aperture by maintaining a one-axis tracking trough as the primary concentrator, while allowing the thermodynamic limit of concentration in 2D of 215× to be significantly surpassed by the implementation of a tracking secondary stage. The limits of overall geometric concentration are found to exceed 4000× when hollow secondary concentrators are used, and 6000× when the receiver is immersed in a dielectric material of refractive index n=1.5. Three exemplary collectors, with geometric concentrations in the range of 500-1500× are explored and their geometric performance is ascertained by Monte Carlo ray-tracing. The proposed solar concentrator design is well-suited for large-scale applications with discrete, flat receivers requiring concentration ratios in the range 500-2000×.

Determination of polyfluoroalkyl phosphoric acid diesters, perfluoroalkyl phosphonic acids, perfluoroalkyl phosphinic acids, perfluoroalkyl carboxylic acids, and perfluoroalkane sulfonic acids in lake trout from the Great Lakes region.

PubMed

Guo, Rui; Reiner, Eric J; Bhavsar, Satyendra P; Helm, Paul A; Mabury, Scott A; Braekevelt, Eric; Tittlemier, Sheryl A

2012-11-01

A comprehensive method to extract perfluoroalkyl carboxylic acids, perfluoroalkane sulfonic acids, perfluoroalkyl phosphonic acids, perfluoroalkyl phosphinic acids, and polyfluoroalkyl phosphoric acid diesters simultaneously from fish samples has been developed. The recoveries of target compounds ranged from 78 % to 121 %. The new method was used to analyze lake trout (Salvelinus namaycush) from the Great Lakes region. The results showed that the total perfluoroalkane sulfonate concentrations ranged from 0.1 to 145 ng/g (wet weight) with perfluorooctane sulfonate (PFOS) as the dominant contaminant. Concentrations in fish between lakes were in the order of Lakes Ontario ≈ Erie > Huron > Superior ≈ Nipigon. The total perfluoroalkyl carboxylic acid concentrations ranged from 0.2 to 18.2 ng/g wet weight. The aggregate mean perfluorooctanoic acid (PFOA) concentration in fish across all lakes was 0.045 ± 0.023 ng/g. Mean concentrations of PFOA were not significantly different (p > 0.1) among the five lakes. Perfluoroalkyl phosphinic acids were detected in lake trout from Lake Ontario, Lake Erie, and Lake Huron with concentration ranging from non-detect (ND) to 0.032 ng/g. Polyfluoroalkyl phosphoric acid diesters were detected only in lake trout from Lake Huron, at levels similar to perfluorooctanoic acid.

Effect of Temperature and Nutrient Manipulations on eelgrass ...

EPA Pesticide Factsheets

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

Characteristics of cabin air quality in school buses in Central Texas

NASA Astrophysics Data System (ADS)

Rim, Donghyun; Siegel, Jeffrey; Spinhirne, Jarett; Webb, Alba; McDonald-Buller, Elena

This study assessed in-cabin concentrations of diesel-associated air pollutants in six school buses with diesel engines during a typical route in suburban Austin, Texas. Air exchange rates measured by SF 6 decay were 2.60-4.55 h -1. In-cabin concentrations of all pollutants measured exhibited substantial variability across the range of tests even between buses of similar age, mileage, and engine type. In-cabin NO x concentrations ranged from 44.7 to 148 ppb and were 1.3-10 times higher than roadway NO x concentrations. Mean in-cabin PM 2.5 concentrations were 7-20 μg m -3 and were generally lower than roadway levels. In-cabin concentrations exhibited higher variability during cruising mode than frequent stops. Mean in-cabin ultrafine PM number concentrations were 6100-32,000 particles cm -3 and were generally lower than roadway levels. Comparison of median concentrations indicated that in-cabin ultrafine PM number concentrations were higher than or approximately the same as the roadway concentrations, which implied that, by excluding the bias caused by local traffic, ultrafine PM levels were higher in the bus cabin than outside of the bus. Cabin pollutant concentrations on three buses were measured prior to and following the phased installation of a Donaldson Spiracle Crankcase Filtration System and a Diesel Oxidation Catalyst. Following installation of the Spiracle, the Diesel Oxidation Catalyst provided negligible or small additional reductions of in-cabin pollutant levels. In-cabin concentration decreases with the Spiracle alone ranged from 24 to 37% for NO x and 26 to 62% and 6.6 to 43% for PM 2.5 and ultrafine PM, respectively. Comparison of the ranges of PM 2.5 and ultrafine PM variations between repetitive tests suggested that retrofit installation could not always be conclusively linked to the decrease of pollutant levels in the bus cabin.

Determination of changes in the metabolic profile of avocado fruits (Persea americana) by two CE-MS approaches (targeted and non-targeted).

PubMed

Contreras-Gutiérrez, Paulina K; Hurtado-Fernández, Elena; Gómez-Romero, María; Ignacio Hormaza, José; Carrasco-Pancorbo, Alegría; Fernández-Gutiérrez, Alberto

2013-10-01

A CZE method with two different MS detection conditions (MRM and Full Scan) was developed to determine qualitative and quantitative changes in the metabolic profile of avocado fruits (Persea americana). LODs in MRM approach were found between 20.1 and 203.0 ppb for abscisic acid and perseitol, respectively, whilst in Full Scan, varied within the range 0.22–1.90 ppm for the same metabolites. The RSDs for reproducibility test did not exceed 11.45%. The two MS approaches were used to quantify 10 metabolites (phenolic acids, flavonoids, a carbohydrate, an organic acid, a vitamin and a phytohormone) in 18 samples of avocado at different ripening states, and the achieved results were compared. Perseitol, quinic, chlorogenic, trans-cinnamic, pantothenic and abscisic acids, as well as epicatechin and catechin decreased during the ripening process, whereas ferulic and p-coumaric acids showed the opposite trend. Moreover, some other unknown compounds whose concentration changed largely during ripening were also studied by MS/MS and QTOF MS to get a tentative identification.

Competition Among Reputations in the 2D Sznajd Model: Spontaneous Emergence of Democratic States

NASA Astrophysics Data System (ADS)

Crokidakis, Nuno; Forgerini, Fabricio L.

2012-04-01

We propose a modification in the Sznajd sociophysics model defined on the square lattice. For this purpose, we consider reputation—a mechanism limiting the agents' persuasive power. The reputation is introduced as a time-dependent score, which can be positive or negative. This mechanism avoids dictatorship (full consensus, all spins parallel) for a wide range of model parameters. We consider two different situations: case 1, in which the agents' reputation increases for each persuaded neighbor, and case 2, in which the agents' reputation increases for each persuasion and decreases when a neighbor keeps his opinion. Our results show that the introduction of reputation avoids full consensus even for initial densities of up spins greater than 1/2. The relaxation times follow a log-normal-like distribution in both cases, but they are larger in case 2 due to the competition among reputations. In addition, we show that the usual phase transition occurs and depends on the initial concentration d of individuals with the same opinion, but the critical points d c in the two cases are different.

Post-mortem quetiapine concentrations in hair segments of psychiatric patients - Correlation between hair concentration, dose and concentration in blood.

PubMed

Günther, Kamilla Nyborg; Johansen, Sys Stybe; Nielsen, Marie Katrine Klose; Wicktor, Petra; Banner, Jytte; Linnet, Kristian

2018-04-01

Drug analysis in hair is useful when seeking to establish drug intake over a period of months to years. Segmental hair analysis can also document whether psychiatric patients are receiving a stable intake of antipsychotics. This study describes segmental analysis of the antipsychotic drug quetiapine in post-mortem hair samples from long-term quetiapine users by ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) analysis. The aim was to obtain more knowledge on quetiapine concentrations in hair and to relate the concentration in hair to the administered dose and the post-mortem concentration in femoral blood. We analyzed hair samples from 22 deceased quetiapine-treated individuals, who were divided into two groups: natural hair colour and dyed/bleached hair. Two to six 1cm long segments were analyzed per individual, depending on the length of the hair, with 6cm corresponding to the last six months before death. The average daily quetiapine dose and average concentration in hair for the last six months prior to death were examined for potential correlation. Estimated doses ranged from 45 to 1040mg quetiapine daily over the period, and the average concentration in hair ranged from 0.18 to 13ng/mg. A significant positive correlation was observed between estimated daily dosage of quetiapine and average concentration in hair for individuals with natural hair colour (p=0.00005), but statistical significance was not reached for individuals with dyed/bleached hair (p=0.31). The individual coefficient of variation (CV) of the quetiapine concentrations between segments ranged from 3 to 34% for individuals with natural hair colour and 22-62% for individuals with dyed/bleached hair. Dose-adjusted concentrations in hair were significantly lower in females with dyed/bleached hair than in individuals with natural hair colour. The quetiapine concentrations in post-mortem femoral blood and in the proximal hair segment, segment 1 (S1), representing the last month before death were also investigated for correlation. A significant positive correlation was observed between quetiapine concentrations in blood at the time of death and concentrations in S1 for individuals with natural hair colour (p=0.003) but not for individuals with dyed/bleached hair (p=0.31). The blood concentrations of quetiapine ranged from 0.006 to 1.9mg/kg, and the quetiapine concentrations in S1 ranged from 0.22 to 24ng/mg. The results of this study suggest a positive correlation of quetiapine between both concentrations in hair and doses, and between proximal hair (S1) and blood concentrations, when conditions such as hair treatments are taken into consideration. Copyright © 2018 Elsevier B.V. All rights reserved.

Preliminary observations on the concentration of marine bacteriophages in the water around Helgoland

NASA Astrophysics Data System (ADS)

Moebus, K.

1991-12-01

In a preliminary survey, conducted between August 28 and October 9, 1990, the concentration of bacteriophages in seawater sampled at intervals of 1 to 4 days near Helgoland (station Kabeltonne) was determined by using indicator bacteria which had been isolated from seawater sampled only some weeks before. With a number of bacterial strains, phage concentrations ranging between 2 and 7×102ml-1 were found. However, during the course of this investigation maximal concentrations lasted for a few days only. With most indicator bacteria employed, the concentration of plaque-forming units (PFU) varied in the range of <1 and 20 30 PFU ml-1.

Calculating osmotic pressure of glucose solutions according to ASOG model and measuring it with air humidity osmometry.

PubMed

Wei, Guocui; Zhan, Tingting; Zhan, Xiancheng; Yu, Lan; Wang, Xiaolan; Tan, Xiaoying; Li, Chengrong

2016-09-01

The osmotic pressure of glucose solution at a wide concentration range was calculated using ASOG model and experimentally determined by our newly reported air humidity osmometry. The measurements from air humidity osmometry were compared with the well-established freezing point osmometry and ASOG model calculations at low concentrations and with only ASOG model calculations at high concentrations where no standard experimental method could serve as a reference for comparison. Results indicate that air humidity osmometry measurements are comparable to ASOG model calculations at a wide concentration range, while at low concentrations freezing point osmometry measurements provide better comparability with ASOG model calculations.

Direct and quantitative AFM measurements of the concentration and temperature dependence of the hydrophobic force law at nanoscopic contacts.

PubMed

Stock, Philipp; Utzig, Thomas; Valtiner, Markus

2015-05-15

By virtue of its importance for self-organization of biological matter the hydrophobic force law and the range of hydrophobic interactions (HI) have been debated extensively over the last 40 years. Here, we directly measure and quantify the hydrophobic force-distance law over large temperature and concentration ranges. In particular, we study the HI between molecularly smooth hydrophobic self-assembled monolayers, and similarly modified gold-coated AFM tips (radii∼8-50 nm). We present quantitative and direct evidence that the hydrophobic force is both long-ranged and exponential down to distances of about 1-2 nm. Therefore, we introduce a self-consistent radius-normalization for atomic force microscopy data. This approach allows quantitative data fitting of AFM-based experimental data to the recently proposed Hydra-model. With a statistical significance of r(2)⩾0.96 our fitting and data directly reveal an exponential HI decay length of 7.2±1.2 Å that is independent of the salt concentration up to 750 mM. As such, electrostatic screening does not have a significant influence on the HI in electrolyte concentrations ranging from 1 mM to 750 mM. In 1 M solutions the observed instability during approach shifts to longer distances, indicating ion correlation/adsorption effects at high salt concentrations. With increasing temperature the magnitude of HI decreases monotonically, while the range increases slightly. We compare our results to the large body of available literature, and shed new light into range and magnitude of hydrophobic interactions at very close distances and over wide temperature and concentration regimes. Copyright © 2015 Elsevier Inc. All rights reserved.

Racial and ethnic variations in phthalate metabolite concentration changes across full-term pregnancies.

PubMed

James-Todd, Tamarra M; Meeker, John D; Huang, Tianyi; Hauser, Russ; Seely, Ellen W; Ferguson, Kelly K; Rich-Edwards, Janet W; McElrath, Thomas F

2017-03-01

Higher concentrations of certain phthalate metabolites are associated with adverse reproductive and pregnancy outcomes, as well as poor infant/child health outcomes. In non-pregnant populations, phthalate metabolite concentrations vary by race/ethnicity. Few studies have documented racial/ethnic differences between phthalate metabolite concentrations at multiple time points across the full-course of pregnancy. The objective of the study was to characterize the change in phthalate metabolite concentrations by race/ethnicity across multiple pregnancy time points. Women were participants in a prospectively collected pregnancy cohort who delivered at term (≥37 weeks) and had available urinary phthalate metabolite concentrations for ≥3 time points across full-term pregnancies (n=350 women). We assessed urinary concentrations of eight phthalate metabolites that were log-transformed and specific gravity-adjusted. We evaluated the potential racial/ethnic differences in phthalate metabolite concentrations at baseline (median 10 weeks gestation) using ANOVA and across pregnancy using linear mixed models to calculate the percent change and 95% confidence intervals adjusted for sociodemographic and lifestyle factors. Almost 30% of the population were non-Hispanic black or Hispanic. With the exception of mono-(3-carboxypropyl) (MCPP) and di-ethylhexyl phthalate (DEHP) metabolites, baseline levels of phthalate metabolites were significantly higher in non-whites (P<0.05). When evaluating patterns by race/ethnicity, mono-ethyl phthalate (MEP) and MCPP had significant percent changes across pregnancy. MEP was higher in Hispanics at baseline and decreased in mid-pregnancy but increased in late pregnancy for non-Hispanic blacks. MCPP was substantially higher in non-Hispanic blacks at baseline but decreased later in pregnancy. Across pregnancy, non-Hispanic black and Hispanic women had higher concentrations of certain phthalate metabolites. These differences may have implications for racial/ethnic differences in adverse pregnancy and child health outcomes.

Exploring Manganese Fractionation Using a Sequential Extraction Method to Evaluate Welders' Gas Metal Arc Welding Exposures during Heavy Equipment Manufacturing.

PubMed

Hanley, Kevin W; Andrews, Ronnee; Bertke, Steven; Ashley, Kevin

2017-01-01

The National Institute for Occupational Safety and Health (NIOSH) has conducted an occupational exposure assessment study of manganese (Mn) in welding fume at three factories where heavy equipment was manufactured. The objective of this study was to evaluate exposures to different Mn fractions using a sequential extraction procedure. One hundred nine worker-days were monitored for either total or respirable Mn during gas metal arc welding. The samples were analyzed using an experimental method to separate different Mn fractions based on selective chemical solubility. The full-shift total particle size Mn time-weighted average (TWA) breathing zone concentrations ranged 0.38-26 for soluble Mn in a mild ammonium acetate solution; 3.2-170 for Mn0,2+ in acetic acid; 3.1-290 for Mn3+,4+ in hydroxylamine-hydrochloride; and non-detectable (ND)-130 µg m-3 for insoluble Mn fractions in hydrochloric and nitric acid. The summation of all the total particulate Mn TWA fractions yielded results that ranged from 6.9 to 610 µg m-3. The range of respirable size Mn TWA concentrations were 0.33-21 for soluble Mn; 15-140 for Mn0,2+; 14-170 for Mn3+,4+; 5.3-230 for insoluble Mn; and 36-530 µg m-3 for Mn (sum of fractions). Total particulate TWA GM concentrations of the Mn (sum) were 53 (GSD = 2.5), 150 (GSD = 1.7), and 120 (GSD = 1.8) µg m-3 for the three separate factories. Although all of the workers' exposures were measured below the OSHA regulatory permissible exposure limit and NIOSH recommended exposure limit for Mn, 70 welders' exposures exceeded the ACGIH Threshold Limit Values® for total Mn (100 µg m-3) and 29 exceeded the recently adopted respirable Mn TLV (20 µg m-3). This study shows that a welding fume exposure control and management program is warranted for Mn, which includes improved exhaust ventilation and may necessitate the use of respiratory protection, especially for welding parts that impede air circulation. Published by Oxford University Press on behalf of the British Occupational Hygiene Society 2017.

Magma ascent and lava flow emplacement rates during the 2011 Axial Seamount eruption based on CO2 degassing

NASA Astrophysics Data System (ADS)

Jones, M. R.; Soule, S. A.; Gonnermann, H. M.; Le Roux, V.; Clague, D. A.

2018-07-01

Quantitative metrics for eruption rates at mid-ocean ridges (MORs) would improve our understanding of the structure and formation of the uppermost oceanic crust and would provide a means to link volcanic processes with the conditions of the underlying magmatic system. However, these metrics remain elusive because no MOR eruptions have been directly observed. The possibility of disequilibrium degassing in mid-ocean ridge basalts (MORB), due to high eruptive depressurization rates, makes the analysis of volatile concentrations in MORB glass a promising method for evaluating eruption rates. In this study, we estimate magma ascent and lava flow emplacement rates during the 2011 eruption of Axial Seamount based on numerical modeling of diffusion-controlled bubble growth and new measurements of dissolved volatiles, vesicularity, and vesicle size distributions in erupted basalts. This dataset provides a unique view of the variability in magma ascent (∼0.02-1.2 m/s) and lava flow rates (∼0.1-0.7 m/s) during a submarine MOR eruption based on 50 samples collected from a >10 km long fissure system and three individual lava flow lobes. Samples from the 2011 eruption display an unprecedented range in dissolved CO2 concentrations, nearly spanning the full range observed on the global MOR system. The variable vesicularity and dissolved CO2 concentrations in these samples can be explained by differences in the extent of degassing, dictated by flow lengths and velocities during both vertical ascent and horizontal flow along the seafloor. Our results document, for the first time, the variability in magma ascent rates during a submarine eruption (∼0.02-1.2 m/s), which spans the global range previously proposed based on CO2 degassing. The slowest ascent rates are associated with hummocky flows while faster ascent rates produce channelized sheet flows. This study corroborates degassing-based models for eruption rates using comparisons with independent methods and documents the relationship between eruption dynamics, magma ascent rates, and the morphology of eruptive products. Globally, this approach allows interrogation of the processes that govern mid-ocean ridge eruptions and influence the formation of the oceanic crust.

Application of High-Throughput Next-Generation Sequencing for HLA Typing on Buccal Extracted DNA: Results from over 10,000 Donor Recruitment Samples

PubMed Central

Nguyen, David; Valenzuela, Nicole; Takemura, Ping; Bolon, Yung-Tsi; Springer, Brianna; Saito, Katsuyuki; Zheng, Ying; Hague, Tim; Pasztor, Agnes; Horvath, Gyorgy; Rigo, Krisztina; Reed, Elaine F.; Zhang, Qiuheng

2016-01-01

Background Unambiguous HLA typing is important in hematopoietic stem cell transplantation (HSCT), HLA disease association studies, and solid organ transplantation. However, current molecular typing methods only interrogate the antigen recognition site (ARS) of HLA genes, resulting in many cis-trans ambiguities that require additional typing methods to resolve. Here we report high-resolution HLA typing of 10,063 National Marrow Donor Program (NMDP) registry donors using long-range PCR by next generation sequencing (NGS) approach on buccal swab DNA. Methods Multiplex long-range PCR primers amplified the full-length of HLA class I genes (A, B, C) from promotor to 3’ UTR. Class II genes (DRB1, DQB1) were amplified from exon 2 through part of exon 4. PCR amplicons were pooled and sheared using Covaris fragmentation. Library preparation was performed using the Illumina TruSeq Nano kit on the Beckman FX automated platform. Each sample was tagged with a unique barcode, followed by 2×250 bp paired-end sequencing on the Illumina MiSeq. HLA typing was assigned using Omixon Twin software that combines two independent computational algorithms to ensure high confidence in allele calling. Consensus sequence and typing results were reported in Histoimmunogenetics Markup Language (HML) format. All homozygous alleles were confirmed by Luminex SSO typing and exon novelties were confirmed by Sanger sequencing. Results Using this automated workflow, over 10,063 NMDP registry donors were successfully typed under high-resolution by NGS. Despite known challenges of nucleic acid degradation and low DNA concentration commonly associated with buccal-based specimens, 97.8% of samples were successfully amplified using long-range PCR. Among these, 98.2% were successfully reported by NGS, with an accuracy rate of 99.84% in an independent blind Quality Control audit performed by the NDMP. In this study, NGS-HLA typing identified 23 null alleles (0.023%), 92 rare alleles (0.091%) and 42 exon novelties (0.042%). Conclusion Long-range, unambiguous HLA genotyping is achievable on clinical buccal swab-extracted DNA. Importantly, full-length gene sequencing and the ability to curate full sequence data will permit future interrogation of the impact of introns, expanded exons, and other gene regulatory sequences on clinical outcomes in transplantation. PMID:27798706

Application of High-Throughput Next-Generation Sequencing for HLA Typing on Buccal Extracted DNA: Results from over 10,000 Donor Recruitment Samples.

PubMed

Yin, Yuxin; Lan, James H; Nguyen, David; Valenzuela, Nicole; Takemura, Ping; Bolon, Yung-Tsi; Springer, Brianna; Saito, Katsuyuki; Zheng, Ying; Hague, Tim; Pasztor, Agnes; Horvath, Gyorgy; Rigo, Krisztina; Reed, Elaine F; Zhang, Qiuheng

2016-01-01

Unambiguous HLA typing is important in hematopoietic stem cell transplantation (HSCT), HLA disease association studies, and solid organ transplantation. However, current molecular typing methods only interrogate the antigen recognition site (ARS) of HLA genes, resulting in many cis-trans ambiguities that require additional typing methods to resolve. Here we report high-resolution HLA typing of 10,063 National Marrow Donor Program (NMDP) registry donors using long-range PCR by next generation sequencing (NGS) approach on buccal swab DNA. Multiplex long-range PCR primers amplified the full-length of HLA class I genes (A, B, C) from promotor to 3' UTR. Class II genes (DRB1, DQB1) were amplified from exon 2 through part of exon 4. PCR amplicons were pooled and sheared using Covaris fragmentation. Library preparation was performed using the Illumina TruSeq Nano kit on the Beckman FX automated platform. Each sample was tagged with a unique barcode, followed by 2×250 bp paired-end sequencing on the Illumina MiSeq. HLA typing was assigned using Omixon Twin software that combines two independent computational algorithms to ensure high confidence in allele calling. Consensus sequence and typing results were reported in Histoimmunogenetics Markup Language (HML) format. All homozygous alleles were confirmed by Luminex SSO typing and exon novelties were confirmed by Sanger sequencing. Using this automated workflow, over 10,063 NMDP registry donors were successfully typed under high-resolution by NGS. Despite known challenges of nucleic acid degradation and low DNA concentration commonly associated with buccal-based specimens, 97.8% of samples were successfully amplified using long-range PCR. Among these, 98.2% were successfully reported by NGS, with an accuracy rate of 99.84% in an independent blind Quality Control audit performed by the NDMP. In this study, NGS-HLA typing identified 23 null alleles (0.023%), 92 rare alleles (0.091%) and 42 exon novelties (0.042%). Long-range, unambiguous HLA genotyping is achievable on clinical buccal swab-extracted DNA. Importantly, full-length gene sequencing and the ability to curate full sequence data will permit future interrogation of the impact of introns, expanded exons, and other gene regulatory sequences on clinical outcomes in transplantation.

Quantitative comparison between full-spectrum and filter-based imaging in hyperspectral fluorescence microscopy

PubMed Central

GAO, L.; HAGEN, N.; TKACZYK, T.S.

2012-01-01

Summary We implement a filterless illumination scheme on a hyperspectral fluorescence microscope to achieve full-range spectral imaging. The microscope employs polarisation filtering, spatial filtering and spectral unmixing filtering to replace the role of traditional filters. Quantitative comparisons between full-spectrum and filter-based microscopy are provided in the context of signal dynamic range and accuracy of measured fluorophores’ emission spectra. To show potential applications, a five-colour cell immunofluorescence imaging experiment is theoretically simulated. Simulation results indicate that the use of proposed full-spectrum imaging technique may result in three times improvement in signal dynamic range compared to that can be achieved in the filter-based imaging. PMID:22356127

Highly concentrated nebular noble gases in porous nanocarbon separates from the Saratov (L4) meteorite

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

Amari, Sachiko; Matsuda, Jun-ichi; Stroud, Rhonda M.

2013-11-20

The majority of heavy noble gases (Ar, Kr, and Xe) in primitive meteorites are stored in a poorly understood phase called Q. Although Q is thought to be carbonaceous, the full identity of the phase has remained elusive for almost four decades. In order to better characterize phase Q and, in turn, the early solar nebula, we separated carbon-rich fractions from the Saratov (L4) meteorite. We chose this meteorite because Q is most resistant in thermal alteration among carbonaceous noble gas carriers in meteorites and we hoped that, in this highly metamorphosed meteorite, Q would be present but not diamond:more » these two phases are very difficult to separate from each other. One of the fractions, AJ, has the highest {sup 132}Xe concentration of 2.1 × 10{sup –6} cm{sup 3} STP g{sup –1}, exceeding any Q-rich fractions that have yet been analyzed. Transmission electron microscopy studies of the fraction AJ and a less Q-rich fraction AI indicate that they both are primarily porous carbon that consists of domains with short-range graphene orders, with variable packing in three dimensions, but no long-range graphitic order. The relative abundance of Xe and C atoms (6:10{sup 9}) in the separates indicates that individual noble gas atoms are associated with only a minor component of the porous carbon, possibly one or more specific arrangements of the nanoparticulate graphene.« less

Six orders of magnitude dynamic range in capillary electrophoresis with ultrasensitive laser-induced fluorescence detection

PubMed Central

Whitmore, Colin D.; Essaka, David; Dovichi, Norman J.

2009-01-01

An ultrasensitive laser-induced fluorescence detector was used with capillary electrophoresis for the study of 5-carboxy-tetramethylrhodamine. The raw signal from the detector provided roughly three orders of magnitude dynamic range. The signal saturated at high analyte concentrations due to the dead time associated with the single-photon counting avalanche photodiode employed in the detector. The signal can be corrected for the detector dead time, providing an additional order of magnitude dynamic range. To further increase dynamic range, two fiber-optic beam-splitters were cascaded to generate a primary signal and two attenuated signals, each monitored by a single-photon counting avalanche photodiode. The combined signals from the three photodiodes are reasonably linear from the concentration detection limit of 3 pM to 10 μM, the maximum concentration investigated, a range of 3,000,000. Mass detection limits were 150 yoctomoles injected onto the capillary. PMID:19836546

Influence of the Ag concentration on the medium-range order in a CuZrAlAg bulk metallic glass

DOE PAGES

Gammer, C.; Escher, B.; Ebner, C.; ...

2017-03-21

Fluctuation electron microscopy of bulk metallic glasses of CuZrAl(Ag) demonstrates that medium-range order is sensitive to minor compositional changes. Furthermore, by analyzing nanodiffraction patterns medium-range order is detected with crystal-like motifs based on the B2 CuZr structure and its distorted structures resembling the martensitic ones. This result thus demonstrates some structural homology between the metallic glass and its high temperature crystalline phase. The amount of medium-range order seems slightly affected with increasing Ag concentration (0, 2, 5 at.%) but the structural motifs of the medium-range ordered clusters become more diverse at the highest Ag concentration. The decrease of dominant clustersmore » is consistent with the destabilization of the B2 structure measured by calorimetry and accounts for the increased glass-forming ability.« less

Influence of the Ag concentration on the medium-range order in a CuZrAlAg bulk metallic glass

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

Gammer, C.; Escher, B.; Ebner, C.

Fluctuation electron microscopy of bulk metallic glasses of CuZrAl(Ag) demonstrates that medium-range order is sensitive to minor compositional changes. Furthermore, by analyzing nanodiffraction patterns medium-range order is detected with crystal-like motifs based on the B2 CuZr structure and its distorted structures resembling the martensitic ones. This result thus demonstrates some structural homology between the metallic glass and its high temperature crystalline phase. The amount of medium-range order seems slightly affected with increasing Ag concentration (0, 2, 5 at.%) but the structural motifs of the medium-range ordered clusters become more diverse at the highest Ag concentration. The decrease of dominant clustersmore » is consistent with the destabilization of the B2 structure measured by calorimetry and accounts for the increased glass-forming ability.« less

Cure of tuberculosis despite serum concentrations of antituberculosis drugs below published reference ranges.

PubMed

Meloni, Monica; Corti, Natascia; Müller, Daniel; Henning, Lars; Gutteck, Ursula; von Braun, Amrei; Weber, Rainer; Fehr, Jan

2015-01-01

Therapeutic target serum concentrations of first-line antituberculosis drugs have not been well defined in clinical studies in tuberculosis (TB) patients. We retrospectively investigated the estimated maximum serum concentrations (eC max) of antituberculosis drugs and clinical outcome of TB patients with therapeutic drug monitoring performed between 2010-2012 at our institution, and follow-up until March 2014. The eC max was defined as the highest serum concentration during a sampling period (2, 4 and 6 hours after drug ingestion). We compared the results with published eC max values, and categorised them as either "within reference range", "low eC max", or "very low eC max".Low/very low eC max-levels were defined as follows: isoniazid 2-3/<2 mg/l, rifampicin 4-8/<4 mg/l, rifabutin 0.2-0.3/<0.2 mg/l, ethambutol 1-2/<0.1 mg/l and pyrazinamide <20 mg/l. Concentrations of antituberculosis drugs in 175 serum samples of 17 patients with TB were analysed. In 12 (71%) patients, multiple therapeutic drug monitoring samples were collected over time, in 5 (29%) patients only one sample was available for therapeutic drug monitoring. Overall, 94% of all patients had at least one low antituberculosis drug concentration. Overall, 64% of all eC max levels were classified as "low" or "very low". The eC max was below the relevant reference range in 80% of isoniazid, 95% of rifampicin, 30% of pyrazinamide, and 30% of ethambutol measurements. All but one patient were cured of tuberculosis. Although many antituberculosis drug serum concentrations were below the widely used reference ranges, 16 of 17 patients were cured of tuberculosis. These results challenge the use of the published reference ranges for therapeutic drug monitoring.

Chemicals of emerging concern in water and bottom sediment in the Great Lakes Basin, 2012: collection methods, analytical methods, quality assurance, and study data

USGS Publications Warehouse

Lee, Kathy E.; Langer, Susan K.; Menheer, Michael A.; Hansen, Donald S.; Foreman, William T.; Furlong, Edward T.; Jorgenson, Zachary G.; Choy, Steven J.; Moore, Jeremy N.; Banda, JoAnn; Gefell, Daniel J.

2015-01-01

During this study, 53 environmental samples, 4 field duplicate samples, and 8 field spike samples of bottom sediment and laboratory matrix-spike samples were analyzed for a wide variety of CECs at the USGS National Water Quality Laboratory using laboratory schedule 5433 for wastewater indicators; research method 6434 for steroid hormones, sterols, and bisphenol A; and research method 9008 for human-use pharmaceuticals and antidepressants. Forty of the 57 chemicals analyzed using laboratory schedule 5433 had detectable concentrations ranging from 1 to 49,000 micrograms per kilogram. Fourteen of the 20 chemicals analyzed using research method 6434 had detectable concentrations ranging from 0.04 to 24,940 nanograms per gram. Ten of the 20 chemicals analyzed using research method 9008 had detectable concentrations ranging from 0.59 to 197.5 micrograms per kilogram. Five of the 11 chemicals analyzed using research method 9008 had detectable concentrations ranging from 1.16 to 25.0 micrograms per kilogram.

Trace analysis of antidepressant pharmaceuticals and their select degradates in aquatic matrixes by LC/ESI/MS/MS

USGS Publications Warehouse

Schultz, M.M.; Furlong, E.T.

2008-01-01

Treated wastewater effluent is a potential environmental point source for antidepressant pharmaceuticals. A quantitative method was developed for the determination of trace levels of antidepressants in environmental aquatic matrixes using solid-phase extraction coupled with liquid chromatography- electrospray ionization tandem mass spectrometry. Recoveries of parent antidepressants from matrix spiking experiments for the individual antidepressants ranged from 72 to 118% at low concentrations (0.5 ng/L) and 70 to 118% at high concentrations (100 ng/L) for the solid-phase extraction method. Method detection limits for the individual antidepressant compounds ranged from 0.19 to 0.45 ng/L. The method was applied to wastewater effluent and samples collected from a wastewater-dominated stream. Venlafaxine was the predominant antidepressant observed in wastewater and river water samples. Individual antidepressant concentrations found in the wastewater effluent ranged from 3 (duloxetine) to 2190 ng/L (venlafaxine), whereas individual concentrations in the waste-dominated stream ranged from 0.72 (norfluoxetine) to 1310 ng/L (venlafaxine). ?? 2008 American Chemical Society.

Application of Acoustic and Optic Methods for Estimating Suspended-Solids Concentrations in the St. Lucie River Estuary, Florida

USGS Publications Warehouse

Patino, Eduardo; Byrne, Michael J.

2004-01-01

Acoustic and optic methods were applied to estimate suspended-solids concentrations in the St. Lucie River Estuary, southeastern Florida. Acoustic Doppler velocity meters were installed at the North Fork, Speedy Point, and Steele Point sites within the estuary. These sites provide varying flow, salinity, water-quality, and channel cross-sectional characteristics. The monitoring site at Steele Point was not used in the analyses because repeated instrument relocations (due to bridge construction) prevented a sufficient number of samples from being collected at the various locations. Acoustic and optic instruments were installed to collect water velocity, acoustic backscatter strength (ABS), and turbidity data that were used to assess the feasibility of estimating suspended-solids concentrations in the estuary. Other data collected at the monitoring sites include tidal stage, salinity, temperature, and periodic discharge measurements. Regression analyses were used to determine the relations of suspended-solids concentration to ABS and suspended-solids concentration to turbidity at the North Fork and Speedy Point sites. For samples used in regression analyses, measured suspended-solids concentrations at the North Fork and Speedy Point sites ranged from 3 to 37 milligrams per liter, and organic content ranged from 50 to 83 percent. Corresponding salinity for these samples ranged from 0.12 to 22.7 parts per thousand, and corresponding temperature ranged from 19.4 to 31.8 ?C. Relations determined using this technique are site specific and only describe suspended-solids concentrations at locations where data were collected. The suspended-solids concentration to ABS relation resulted in correlation coefficients of 0.78 and 0.63 at the North Fork and Speedy Point sites, respectively. The suspended-solids concentration to turbidity relation resulted in correlation coefficients of 0.73 and 0.89 at the North Fork and Speedy Point sites, respectively. The adequacy of the empirical equations seems to be limited by the number and distribution of suspended-solids samples collected throughout the expected concentration range at the North Fork and Speedy Point sites. Additionally, the ABS relations for both sites seem to overestimate at the low end and underestimate at the high end of the concentration range. Based on the sensitivity analysis, temperature had a greater effect than salinity on estimated suspended-solids concentrations. Temperature also appeared to affect ABS data, perhaps by changing the absorptive and reflective characteristics of the suspended material. Salinity and temperature had no observed effects on the turbidity relation at the North Fork and Speedy Point sites. Estimates of suspended-solids concentrations using ABS data were less 'erratic' than estimates using turbidity data. Combining ABS and turbidity data into one equation did not improve the accuracy of results, and therefore, was not considered.

40 CFR 91.317 - Carbon monoxide analyzer calibration.

Code of Federal Regulations, 2010 CFR

2010-07-01

... to optimize performance on the most sensitive range to be used. (2) Zero the carbon monoxide analyzer with either purified synthetic air or zero-grade nitrogen. (3) Bubble a mixture of three percent CO2 in... than one percent of full scale for ranges above 300 ppm full scale or more than three ppm on ranges...

Lethal mobilization of DDT by cowbirds

USGS Publications Warehouse

Van Velzen, A.C.; Stiles, W.B.; Stickel, L.F.

1972-01-01

This study is an experimental demonstration of lethal mobilization of DDT by brown-headed cowbirds (Molothrus ater) and the effects of food deprivation on the distribution and loss of DDT, DDD, and DDE. The principal experimental group consisted of 20 birds fed a dietary dosage of 100 ppm of DDT for 13 days. After 2 days of full rations of untreated food, they were subjected to food restriction. Food was reduced to 43 percent of normal. Seven of the 20 birds died within 4 days. No birds died in the three control groups, treated as follows: ( 1 ) 20 birds fed 100 ppm DDT for 13 days and full rations of untreated food thereafter, (2) 20 birds fed only untreated food but subjected to food restriction, and (3) 20 birds fed full rations of untreated food throughout. In a pilot study, birds were fed 100, 200, or 300 ppm of DDT and subjected to two periods of food restriction, the first of these immediately after dosage ceased and the second 4 months later. DDT-dosed birds from all dosage levels died in each period of food restriction. Before the weight loss that accompanied food restriction, the brains of DDT-dosed birds had concentrations of DDT and DDD that were far below the lethal range. Concentrations increased rapidly to lethal levels. In these birds, DDT in carcasses decreased while DDD increased. DDT-dosed birds that died during food restriction lost 16 percent of their total body burden of DDT + DDD + DDE, 21 percent of their weight, and 81 percent of their fat. The DDT-dosed birds that were subjected to food restriction but survived lost a significantly greater proportion of their body burden of residues than similarly dosed birds not subjected to weight loss. Brain levels of DDT and DDD in birds that died during food restriction soon after dosage did not differ significantly from brain levels of birds that died in a period of food restriction 4 months after dosage. Concentrations of DDE were significantly higher in the latter group, although they were lower than concentrations considered to be lethal. In contrast, carcass levels of DDT and DDD were significantly lower, and DDE was only slightly higher, in the birds that died in the second period of food restriction. It is concluded that stored DDT residues present a hazard to birds, which utilize stored fat during periods of stress due to reproduction, cold weather, disease, injury, limited food supply, or migration.

Investigation of dioxin concentrations in the lower Roanoke River basin, North Carolina, February 26-March 7, 2001

USGS Publications Warehouse

Miller, K.F.; Walters, D.A.

2001-01-01

Dioxin is a toxic chemical that, when present in the environment, can cause cancer and birth defects in humans. Dioxin is of particular concern because concentrations of dioxin that were released into the environment many years ago remain a contributing factor to current exposure. Dioxin exposure often occurs in surface-water systems downstream from contaminated sites and is detrimental to aquatic life. For these reasons and because the U.S. Geological Survey has expertise in conducting high-volume dioxin sampling, the U.S. Environmental Protection Agency and the State of North Carolina asked the U.S. Geological Survey to collect water samples in the lower Roanoke River to be analyzed for the presence of dioxin. Water quality of the lower Roanoke River Basin in North Carolina was assessed at eight sites during February 26-March 7, 2001. Water- quality samples were collected for analysis of suspended-sediment and dioxin concentrations; high-volume (750-liter) water samples were collected for dioxin analysis. Discharge measurements were made at or near the high-volume sampling sites. Suspended-sediment sampling and water-quality measurements of specific conductance, pH, water temperature, and dissolved-oxygen concentrations made at each sampling site included multidepth measurements at two cross-section transects and hourly measurements at the point of high-volume sampling. Multidepth measurements were made near the surface, mid-depth, and near the bottom of the water column. These values were averaged for each cross section. During the sampling period, all sites sampled had dioxin concentrations above detection limits (1 part per quintillion) for both suspended and dissolved dioxin. Suspended dioxin ranged from 5.1 to 900 femtograms per liter, and dissolved dioxin values ranged from 0.31 to 41 femtograms per liter. Suspended-sediment concentrations ranged from 1.1 to 14 milligrams per liter. Specific conductance values ranges from 111 to 340 microsiemens per centimeter at 25 degrees Celsius. The range of pH values at the sampling sites was from 6.6 to 7.7. Water temperatures ranged from 8.9 to 13 degrees Celsius. Dissolved-oxygen concentrations ranged from 7.3 to 10.9 milligrams per liter.

Effects of ambient ozone on first-year growth and physiology of black cherry (Prunus serotina Ehrh. ) seedlings

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

Kolb, T.E.; Skelly, J.M.; Steiner, K.C.

1993-06-01

Black cherry seedlings of two open-pollinated families were exposed to ambient ozone in open plots (100%) and plots receiving non-filtered (95%), half-filtered (60%) and full-filtered (40%) concentrations via open-top chambers between early June and late-September 1992 in a replicated field experiment in central Pennsylvania. Seasonal 24-hour ambient ozone concentration averaged 34 ppb with a peak 1-hour concentration of 110 ppb. Foliar symptoms of ozone damage (adaxial stipple) occurred most prominently in open and non-filtered plots and differed between families. Net photosynthetic rate for both families was significantly lower in open and non-filtered plots compared with half- and full-filtered plots onmore » most dates, while ozone concentration had no consistent effect on leaf conductance or dark respiration. Leaf conductance of the ozone sensitive family was significantly greater than the ozone tolerant family on most dates. First-year height and diameter growth were significantly lower in open and non-filtered plots compared with half- and full-filtered plots for both families.« less

Water quality (2000-08) and historical phosphorus concentrations from paleolimnological studies of Swamp and Speckled Trout Lakes, Grand Portage Reservation, northeastern Minnesota

USGS Publications Warehouse

Christensen, Victoria G.; Jones, Perry M.; Edlund, Mark B.; Ramstack, Joy M.

2010-01-01

A paleolimnological approach was taken to aid the Grand Portage Reservation, in northeastern Minnesota, in determining reference conditions for lakes on the reservation. The U.S. Geological Survey, in cooperation with the Grand Portage Band of Chippewa Indians and the Science Museum of Minnesota, conducted a study to describe water quality (2000-08) and historical total phosphorus concentrations (approximately 1781-2006) for Swamp and Speckled Trout Lakes. Results from this study may be used as a guide in establishing nutrient criteria in these and other lakes on the Grand Portage Reservation. Historical phosphorus concentrations were inferred through paleolimnological reconstruction methods involving diatom analysis and lead-210 dating of lake-sediment cores. Historical diatom-inferred total phosphorus concentrations in Swamp Lake ranged from 0.017 to 0.025 milligrams per liter (mg/L) based on diatom assemblages in sediment samples dated 1781-2005. Historical diatom-inferred total phosphorus concentrations in Speckled Trout Lake ranged from 0.008 to 0.014 mg/L based on diatom assemblages in sediment samples dated 1825-2006. In both lakes, historical changes in diatom-inferred total phosphorus concentrations did not exceed model error estimates, indicating that there has been minimal change in total phosphorus concentrations in the two lakes over about two centuries. Nutrient concentrations in monthly water samples collected May through October during 2000, 2002, 2004, 2006, and 2008 were compared to the diatom-inferred total phosphorus concentrations. Total phosphorus concentrations from water samples collected from Swamp Lake during 2000-08 ranged from less than 0.002 to 0.160 mg/L (median= 0.023 mg/L) compared to diatom-inferred total phosphorus concentrations of 0.018 to 0.020 mg/L for 2002 to 2005. Total phosphorus concentrations in water samples collected from Speckled Trout Lake during 2000-08 were similar to those of Swamp Lake, ranging from less than 0.002 to 0.147 mg/L (median=0.012 mg/L), whereas the diatom-inferred total phosphorus concentrations were smaller, ranging from 0.009 to 0.010 mg/L for 2003 to 2006. Differences in total phosphorus concentrations between the two lakes may be because of differences in watershed characteristics, particularly the number of wetlands in the two watersheds. Similarities between recent total phosphorus concentrations in water-quality samples and diatom-inferred total phosphorus indicate that diatom-inferred phosphorus reconstructions might be used to help establish reference conditions. Nutrient criteria for Grand Portage Reservation lakes may be established when a sampling program is designed to ensure representative phosphorus concentrations in water samples are comparable to diatom-inferred concentrations.

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

NASA Astrophysics Data System (ADS)

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

2016-11-01

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

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

PubMed

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

2009-09-01

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

Determination of breath acetone in 149 type 2 diabetic patients using a ringdown breath-acetone analyzer.

PubMed

Sun, Meixiu; Chen, Zhuying; Gong, Zhiyong; Zhao, Xiaomeng; Jiang, Chenyu; Yuan, Yuan; Wang, Zhennang; Li, Yingxin; Wang, Chuji

2015-02-01

Over 90% of diabetic patients have Type 2 diabetes. Although an elevated mean breath acetone concentration has been found to exist in Type 1 diabetes (T1D), information on breath acetone in Type 2 diabetes (T2D) has yet to be obtained. In this study, we first used gas chromatography-mass spectrometry (GC-MS) to validate a ringdown breath-acetone analyzer based on the cavity-ringdown-spectroscopy technique, through comparing breath acetone concentrations in the range 0.5-2.5 ppm measured using both methods. The linear fitting of R = 0.99 suggests that the acetone concentrations obtained using both methods are consistent with a largest standard deviation of ±0.4 ppm in the lowest concentration of the range. Next, 620 breath samples from 149 T2D patients and 42 healthy subjects were collected and tested using the breath analyzer. Four breath samples were taken from each subject under each of four different conditions: fasting, 2 h post-breakfast, 2 h post-lunch, and 2 h post-dinner. Simultaneous blood glucose levels were also measured using a standard diabetic-management blood-glucose meter. For the 149 T2D subjects, their exhaled breath acetone concentrations ranged from 0.1 to 19.8 ppm; four different ranges of breath acetone concentration, 0.1-19.8, 0.1-7.1, 0.1-6.3, and 0.1-9.5 ppm, were obtained for the subjects under the four different conditions, respectively. For the 42 healthy subjects, their breath acetone concentration ranged from 0.1 to 2.6 ppm; four different ranges of breath acetone concentration, 0.3-2.6, 0.1-2.6, 0.1-1.7, and 0.3-1.6 ppm, were obtained for the four different conditions. The mean breath acetone concentration of the 149 T2D subjects was determined to be 1.5 ± 1.5 ppm, which was 1.5 times that of 1.0 ± 0.6 ppm for the 42 healthy subjects. No correlation was found between the breath acetone concentration and the blood glucose level of the T2D subjects and the healthy volunteers. This study using a relatively large number of subjects provides new data regarding breath acetone in diabetes (T1D and T2D) and suggests that an elevated mean breath acetone concentration also exists in T2D.

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

NASA Astrophysics Data System (ADS)

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

2017-12-01

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

[Gustometry usefulness for the evaluation of taste sense efficiency. Part I. The range of taste substances concentrations and the result of gustometry examination].

PubMed

Klimacka-Nawrot, Ewa; Suchecka, Wanda; Błońska-Fajfrowska, Barbara

2007-01-01

There are various methods of taste substances application in gustometry examination. The Polish Committee of Standards (Polski Komitet Normalizacyjny--PKN) recommends the performance of sensitivity taste examinations with the use of method based on rinsing out the mouth with water solutions of taste substances (sip-and-spit method) at their growing concentrations. The aim of the present research was to assess the usefulness of taste substances dilutions, whose concentrations were consistent with guidelines of the PKN for the evaluation of the results of examination of sweet, salty and sour taste sensitivity. 795 volunteers, i.e. 473 women and 322 men, aged 18-66, were the subject of study. The range of concentrations in sucrose solutions (0.34-12.00 g/l) as well as in sodium chloride solutions (0.16-2.00 g/l) were proper for examination in order to recognize taste threshold with the most volunteers. However, the use of concentrations in citric acid solutions (in the range 0.13-0.60 g/l) did not enable to investigate the taste sensitivity by reason of the large percentage of persons (85.2%) who correctly recognized the sour taste of the solution with the lowest citric acid concentration. The range of citric acid concentration (0.0036-0.2000 g/l) appeared to be more proper for examination of the sour taste sensitivity. The concentrations of sucrose and sodium chloride solutions recommended by PKN are proper for the examination of sweet and salty taste sensitivity with the use of sip-and-spit method however concentrations of citric acid solutions should be lower than recommended.

Distributions of nutrients, dissolved organic carbon and carbohydrates in the western Arctic Ocean

NASA Astrophysics Data System (ADS)

Wang, Deli; Henrichs, Susan M.; Guo, Laodong

2006-09-01

Seawater samples were collected from stations along a transect across the shelf-basin interface in the western Arctic Ocean during September 2002, and analyzed for nutrients, dissolved organic carbon (DOC), and total dissolved carbohydrate (TDCHO) constituents, including monosaccharides (MCHO) and polysaccharides (PCHO). Nutrients (nitrate, ammonium, phosphate and dissolved silica) were depleted at the surface, especially nitrate. Their concentrations increased with increasing depth, with maxima centered at ˜125 m depth within the halocline layer, then decreased with increasing depth below the maxima. Both ammonium and phosphate concentrations were elevated in shelf bottom waters, indicating a possible nutrient source from sediments, and in a plume that extended into the upper halocline waters offshore. Concentrations of DOC ranged from 45 to 85 μM and had an inverse correlation with salinity, indicating that mixing is a control on DOC concentrations. Concentrations of TDCHO ranged from 2.5 to 19 μM-C, comprising 13-20% of the bulk DOC. Higher DOC concentrations were found in the upper water column over the shelf along with higher TDCHO concentrations. Within the TDCHO pool, the concentrations of MCHO ranged from 0.4 to 8.6 μM-C, comprising 20-50% of TDCHO, while PCHO concentrations ranged from 0.5 to 13.6 μM-C, comprising 50-80% of the TDCHO. The MCHO/TDCHO ratio was low in the upper 25 m of the water column, followed by a high MCHO/TDCHO ratio between 25 and 100 m, and a low MCHO/TDCHO ratio again below 100 m. The high MCHO/TDCHO ratio within the halocline layer likely resulted from particle decomposition and associated release of MCHO, whereas the low MCHO/TDCHO (or high PCHO/TDCHO) ratio below the halocline layer could have resulted from slow decomposition and additional particulate CHO sources.

Chromium concentrations in ruminant feed ingredients.

PubMed

Spears, J W; Lloyd, K E; Krafka, K

2017-05-01

Chromium (Cr), in the form of Cr propionate, has been permitted for supplementation to cattle diets in the United States at levels up to 0.50 mg of Cr/kg of DM since 2009. Little is known regarding Cr concentrations naturally present in practical feed ingredients. The present study was conducted to determine Cr concentrations in feed ingredients commonly fed to ruminants. Feed ingredients were collected from dairy farms, feed mills, grain bins, and university research farms. Mean Cr concentrations in whole cereal grains ranged from 0.025 mg/kg of DM for oats to 0.041 mg/kg of DM for wheat. Grinding whole samples of corn, soybeans, and wheat through a stainless steel Wiley mill screen greatly increased analyzed Cr concentrations. Harvested forages had greater Cr concentrations than concentrates, and alfalfa hay or haylage had greater Cr concentrations than grass hay or corn silage. Chromium in alfalfa hay or haylage (n = 13) averaged 0.522 mg/kg of DM, with a range of 0.199 to 0.889 mg/kg of DM. Corn silage (n = 21) averaged 0.220 mg of Cr/kg of DM with a range of 0.105 to 0.441 mg of Cr/kg of DM. By-product feeds ranged from 0.040 mg of Cr/kg of DM for cottonseed hulls to 1.222 mg of Cr/kg of DM for beet pulp. Of the feed ingredients analyzed, feed grade phosphate sources had the greatest Cr concentration (135.0 mg/kg). Most ruminant feedstuffs and feed ingredients had less than 0.50 mg of Cr/kg of DM. Much of the analyzed total Cr in feed ingredients appears to be due to Cr contamination from soil or metal contact during harvesting, processing, or both. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Evaluation of rate law approximations in bottom-up kinetic models of metabolism.

PubMed

Du, Bin; Zielinski, Daniel C; Kavvas, Erol S; Dräger, Andreas; Tan, Justin; Zhang, Zhen; Ruggiero, Kayla E; Arzumanyan, Garri A; Palsson, Bernhard O

2016-06-06

The mechanistic description of enzyme kinetics in a dynamic model of metabolism requires specifying the numerical values of a large number of kinetic parameters. The parameterization challenge is often addressed through the use of simplifying approximations to form reaction rate laws with reduced numbers of parameters. Whether such simplified models can reproduce dynamic characteristics of the full system is an important question. In this work, we compared the local transient response properties of dynamic models constructed using rate laws with varying levels of approximation. These approximate rate laws were: 1) a Michaelis-Menten rate law with measured enzyme parameters, 2) a Michaelis-Menten rate law with approximated parameters, using the convenience kinetics convention, 3) a thermodynamic rate law resulting from a metabolite saturation assumption, and 4) a pure chemical reaction mass action rate law that removes the role of the enzyme from the reaction kinetics. We utilized in vivo data for the human red blood cell to compare the effect of rate law choices against the backdrop of physiological flux and concentration differences. We found that the Michaelis-Menten rate law with measured enzyme parameters yields an excellent approximation of the full system dynamics, while other assumptions cause greater discrepancies in system dynamic behavior. However, iteratively replacing mechanistic rate laws with approximations resulted in a model that retains a high correlation with the true model behavior. Investigating this consistency, we determined that the order of magnitude differences among fluxes and concentrations in the network were greatly influential on the network dynamics. We further identified reaction features such as thermodynamic reversibility, high substrate concentration, and lack of allosteric regulation, which make certain reactions more suitable for rate law approximations. Overall, our work generally supports the use of approximate rate laws when building large scale kinetic models, due to the key role that physiologically meaningful flux and concentration ranges play in determining network dynamics. However, we also showed that detailed mechanistic models show a clear benefit in prediction accuracy when data is available. The work here should help to provide guidance to future kinetic modeling efforts on the choice of rate law and parameterization approaches.

Elvitegravir concentrations in seminal plasma in HIV-1-infected men.

PubMed

Imaz, A; Niubó, J; Kashuba, A D; Ferrer, E; Sykes, C; Rozas, N; Acerete, L; Vila, A; Podzamczer, D

2017-03-01

The aim of the study was to quantify elvitegravir (EVG) concentrations in the semen of HIV-1-infected men receiving antiretroviral therapy (ART) consisting of an elvitegravir/cobicistat/emtricitabine/tenofovir (EVG/COBI/FTC/TDF) single-tablet regimen. A phase IV, cross-sectional study was carried out including HIV-1-infected male adults with suppressed plasma HIV-1 RNA who switched ART to EVG/COBI/FTC/TDF. Total EVG concentrations at the end of the dosing interval (C 24 h ) and HIV-1 RNA were measured in paired seminal plasma (SP) and blood plasma (BP) samples 4 weeks after switching to EVG/COBI/FTC/TDF. Validated liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used to quantify EVG concentrations, and HIV-1 RNA was determined by real-time polymerase chain reaction (PCR). Ten men were included. Their median age was 40 years (range 24-47 years), the median time on ART was 50 months (range 10-186 months), the median time with plasma HIV-1 RNA < 40 copies/mL was 37 months (range 7-113 months), and the median CD4 count was 737 cells/μL (range 190-1122 cells/μL). Four weeks after switching to EVG/COBI/FTC/TDF, all subjects had HIV-1 RNA < 40 copies/mL in both BP and SP. Median EVG C 24 h was 277 ng/mL (range 64.8-1790 ng/mL) in BP and 169 ng/mL (range 12.8-792 ng/mL) in SP. A significant correlation was observed between BP and SP EVG concentrations (Spearman rho 0.952; P < 0.001). The median SP:BP EVG concentration ratio was 0.39 (range 0.20-0.92). EVG C 24 h in SP was at least 23-fold the in vitro protein-unbound 50% effective response (EC 50 ) of HIV-1 clinical isolates (0.04-0.55 ng/mL). In all but one individual, EVG C 24 h in SP was also higher than the blood plasma protein binding-adjusted 95% inhibitory concentration (IC 95 ) of wild-type HIV-1 (45 ng/mL). Seminal EVG concentrations in HIV-infected men treated with EVG/COBI/FTC/TDF sufficed to contribute to maintaining HIV-1 RNA suppression in this compartment. © 2016 British HIV Association.

Influence of full cream milk powder on the characteristics of sweet potato puree instant cream soup

NASA Astrophysics Data System (ADS)

Sunyoto, Marleen; Djali, Mohamad; Dwiastuti, Intan Btari

2018-02-01

A ready to use food such as instant cream soup become the most suitable choice for those who prefer being practical and also can be applied in any emergency situation such as areas affected by disaster. The adding of milk powder as the main ingredient in cream soup creates a complex bounding of fat and starch which complicates the rehydration process and affects other physical appearance. This research was aimed to find the proper concentration of full cream milk powder concentration to obtain the best characteristics of instant cream soup of dried sweet potato puree. The method used in this research was randomized block design with 6 treatments (12.5%, 15%, 17.5%, 20%, 22.5% and 25%, with an addition of full cream milk powder) and twice repetition. Instant cream soup with 20% of full cream milk powder concentration gave the best physical and chemical characteristics. The physical and chemical characteristic shows that it has 6% water content, 95.47% rehydration value, 18% protein, 20.7% fat, 1080.25 cP viscosity and 30.5% rendement.

Comparison of Laboratory-Developed and Commercial Monoclonal Antibody-Based Sandwich Enzyme-Linked Immunosorbent Assays for Almond (Prunus dulcis) Detection and Quantification.

PubMed

Liu, Changqi; Chhabra, Guneet S; Zhao, Jing; Zaffran, Valerie D; Gupta, Sahil; Roux, Kenneth H; Gradziel, Thomas M; Sathe, Shridhar K

2017-10-01

A commercially available monoclonal antibody (mAb)-based direct sandwich enzyme-linked immunosorbent assay (ELISA) kit (BioFront Technologies, Tallahassee, Fla., U.S.A.) was compared with an in-house developed mAb 4C10-based ELISA for almond detection. The assays were comparable in sensitivity (limit of detection < 1 ppm full fat almond, limit of quantification < 5 ppm full fat almond), specificity (no cross-reactivity with 156 tested foods at a concentration of 100000 ppm whole sample), and reproducibility (intra- and interassay variability < 15% CV). The target antigens were stable and detectable in whole almond seeds subjected to autoclaving, blanching, frying, microwaving, and dry roasting. The almond recovery ranges for spiked food matrices were 84.3% to 124.6% for 4C10 ELISA and 81.2% to 127.4% for MonoTrace ELISA. The almond recovery ranges for commercial and laboratory prepared foods with declared/known almond amount were 30.9% to 161.2% for 4C10 ELISA and 38.1% to 207.6% for MonoTrace ELISA. Neither assay registered any false-positive or negative results among the tested commercial and laboratory prepared samples. Ability to detect and quantify trace amounts of almonds is important for improving safety of almond sensitive consumers. Two monoclonal antibody-based ELISAs were compared for almond detection. The information is useful to food industry, regulatory agencies, scientific community, and almond consumers. © 2017 Institute of Food Technologists®.

Home Health Care for California's Injured Workers: Options for Implementing a Fee Schedule.

PubMed

Wynn, Barbara O; Boustead, Anne

2015-07-15

The California Department of Industrial Relations/Division of Worker's Compensation asked RAND to provide technical assistance in developing a fee schedule for home health services provided to injured workers. The fee schedule needs to address the full spectrum of home health services ranging from skilled nursing and therapy services to unskilled personal care or chore services that may be provided by family members. RAND researchers consulted with stakeholders in the California workers' compensation system to outline issues the fee schedule should address, reviewed home health fee schedules used by other payers, and conducted interviews with WC administrators from other jurisdictions to elicit their experiences. California stakeholders identified unskilled attendant services as most problematic in determining need and payment rates, particularly services furnished by family members. RAND researchers concentrated on fee schedule options that would result in a single fee schedule covering the full range of home health care services furnished to injured workers and made three sets of recommendations. The first set pertains to obtaining additional information that would highlight the policy issues likely to occur with the implementation of the fee schedule and alternatives for assessing an injured worker's home health care needs. Another approach conforms most closely with the Labor Code requirements. It would integrate the fee schedules used by Medicare, In-Home Health Supportive Services, and the federal Office of Workers' Compensation. The third approach would base the home health fee schedule on rules used by the federal Office of Workers' Compensation.

DNA electrophoresis in agarose gels: effects of field and gel concentration on the exponential dependence of reciprocal mobility on DNA length.

PubMed

Rill, Randolph L; Beheshti, Afshin; Van Winkle, David H

2002-08-01

Electrophoretic mobilities of DNA molecules ranging in length from 200 to 48 502 base pairs (bp) were measured in agarose gels with concentrations T = 0.5% to 1.3% at electric fields from E = 0.71 to 5.0 V/cm. This broad data set determines a range of conditions over which the new interpolation equation nu(L) = (beta+alpha(1+exp(-L/gamma))(-1) can be used to relate mobility to length with high accuracy. Mobility data were fit with chi(2) > 0.999 for all gel concentrations and fields ranging from 2.5 to 5 V/cm, and for lower fields at low gel concentrations. Analyses using so-called reptation plots (Rousseau, J., Drouin, G., Slater, G. W., Phys. Rev. Lett. 1997, 79, 1945-1948) indicate that this simple exponential relation is obeyed well when there is a smooth transition from the Ogston sieving regime to the reptation regime with increasing DNA length. Deviations from this equation occur when DNA migration is hindered, apparently by entropic-trapping, which is favored at low fields and high gel concentrations in the ranges examined.

Endometrial protein PP14 and CA-125 in recurrent miscarriage patients; correlation with pregnancy outcome.

PubMed

Dalton, C F; Laird, S M; Estdale, S E; Saravelos, H G; Li, T C

1998-11-01

The concentrations of endometrial proteins PP14 and CA-125 were measured in uterine flushings taken on days LH+10 and LH+12 (10 and 12 days after luteinizing hormone surge) of the menstrual cycle from 15 normal, fertile women and 49 women who suffered recurrent miscarriage. The concentration of PP14 was significantly lower in the flushings from the recurrent miscarriage patients than in those from fertile controls on both day LH+10 (median: 1300, range: 3-10 300 ng/ml versus median: 13 933, range: 2174-40 404 ng/ml; P < 0.01) and LH+12 (median: 1560, range: 820-12 100 ng/ml versus median: 14 047, range 1402-62 108 ng/ml; P < 0.05). Similarly concentrations of CA-125 were significantly lower in flushings from recurrent miscarriage women compared to controls on both day LH + 10 (median: 1555, range: 47-6710 U/ml versus median: 6385.5, range 2884-27 731 U/ml, P < 0.01) and LH+12 (median: 2892, range: 956-9974 U/ml versus median: 7127.5, range: 1591-21 343 U/ml; P < 0.05). In contrast there was no significant difference in the concentration of PP14 in plasma samples taken on the same days as the flushings from recurrent miscarriage patients and fertile controls. The concentrations of PP14 in uterine flushings obtained on day LH + 10 or LH + 12 from recurrent miscarriage women during a pre-pregnancy investigative cycle were significantly lower (P < 0.05) in patients who went on to miscarry (median: 1000, range: 9-2900 ng/ml) than those who went on to have a live birth (median: 1440, range: 4-12 100 ng/ml) during a subsequent pregnancy. In contrast there was no significant difference in uterine CA-125 or plasma PP14 concentrations between these two groups of recurrent miscarriage patients. The results suggest that measurements of uterine PP14 and CA-125 may be useful in the assessment of endometrial development in recurrent miscarriage patients and suggest the importance of PP14 in preparing the endometrium for embryo implantation. In addition pre-pregnancy uterine PP14 measurements may be useful in predicting subsequent pregnancy outcome.

Raman and Brillouin scattering of LiClO4 complexed in poly(propylene-glycol)

NASA Astrophysics Data System (ADS)

Schantz, S.; Torell, L. M.; Stevens, J. R.

1988-08-01

Raman spectra of LiClO4 complexed in poly(propylene-glycol) (PPG) have been obtained for concentrations of the monomer to salt ratio (ether oxygen):Li in the range 30:1-5:1. Splitting of the symmetric stretching mode of the ClO4- anion was observed with an intensity profile that varied with salt concentration. This phenomenon indicates a changing environment about the anion. A two-component band analysis leads to the identification of dissociated ions on one hand and solvent-separated ion pairs on the other. The concentration of ion pairs is relatively low compared to that of the dissociated ions, which are predominant for all concentrations. Despite the observed increase in the absolute number of dissociated ions at higher salt concentration, the electrical conductivity is reported to decrease in the same range. This indicates that the number of ``free'' charge carriers is of less importance for the conductivity than the mobility, which is damped in this concentration range. Frequency shifts of the disordered longitudinal-acoustic mode and increased hypersonic velocities, measured with Raman and Brillouin scattering techniques, respectively, indicate increased stiffness of the polymer matrix for increasing salt concentration, which probably results in decreased ion mobility.

Carbonyl levels in indoor and outdoor air in Mexico City and Xalapa, Mexico.

PubMed

Báez, Armando; Padilla, Hugo; García, Rocío; Torres, Ma del Carmen; Rosas, Irma; Belmont, Raúl

2003-01-20

Carbonyl compounds in air were measured at two houses, three museums, and two offices. All sites lacked air-conditioning systems. Although indoor and outdoor air was measured simultaneously at each site, the sites themselves were sampled in different dates. Mean concentrations were higher in indoor air. Outdoor means concentrations of acetone were the highest in all sites, ranging from 12 to 60 microg m(-3). In general, formaldehyde and acetaldehyde had similar mean concentrations, ranging from 4 to 32 and 6 to 28 microg m(-3), respectively. Formaldehyde and acetone mean indoor concentrations were the highest, ranging from 11 to 97 and 17 to 89 microg m(-3), respectively, followed by acetaldehyde with 5 to 47 microg m(-3). Formaldehyde and acetaldehyde had the highest mean concentration in the offices where there were smokers. Propionaldehyde and butyraldehyde concentrations did not show definite differences between indoor and outdoor air. In general, the highest outdoor and indoor hourly concentrations were observed from 10:00 to 15:00 h. Mean indoor/outdoor ratios of carbonyls exceeded 1. Formaldehyde and acetaldehyde risks were higher in smoking environments. Copyright 2002 Elsevier Science B.V.

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

NASA Astrophysics Data System (ADS)

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

2018-03-01

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

Flow Characteristics and Robustness of an Inclined Quad-vortex Range Hood

PubMed Central

CHEN, Jia-Kun; HUANG, Rong Fung

2014-01-01

A novel design of range hood, which was termed the inclined quad-vortex (IQV) range hood, was examined for its flow and containment leakage characteristics under the influence of a plate sweeping across the hood face. A flow visualization technique was used to unveil the flow behavior. Three characteristic flow modes were observed: convex, straight, and concave modes. A tracer gas detection method using sulfur hexafluoride (SF6) was employed to measure the containment leakage levels. The results were compared with the test data reported previously in the literature for a conventional range hood and an inclined air curtain (IAC) range hood. The leakage SF6 concentration of the IQV range hood under the influence of the plate sweeping was 0.039 ppm at a suction flow rate of 9.4 m3/min. The leakage concentration of the conventional range hood was 0.768 ppm at a suction flow rate of 15.0 m3/min. For the IAC range hood, the leakage concentration was 0.326 ppm at a suction flow rate of 10.9 m3/min. The IQV range hood presented a significantly lower leakage level at a smaller suction flow rate than the conventional and IAC range hoods due to its aerodynamic design for flow behavior. PMID:24583513

Concentrations of organic contaminants in mollusks and sediments at NOAA National Status and Trend sites in the coastal and estuarine United States.

PubMed

O'Connor, T P

1991-01-01

Mean concentrations of PAHs, PCBs, and DDT in mollusks and sediments at sites in the National Status and Trends Program (NST) are distributed in log-normal fashion. The dry weight-based chlorinated organic concentrations in mollusks generally exceed those in nearby sediments by an order of magnitude. PAHs are found at similar concentrations in sediments and mollusks. Highest concentrations of PCBs and DDT in mollusks are in the ranges of 1000 to 4000 ng/g (dry) and 400 to 1000 ng/g (dry), respectively. The highest PAH concentrations in sediments are in the 10,000 to 50,000 ng/g (dry) range. While higher concentrations of contaminants can be found by sampling localized hot spots, the NST data represent the distribution of concentrations over general areas of the coastal United States.

Polychlorinated dibenzo-p-dioxins and dibenzofurans detected in bivalve samples from the NOAA National Status and Trends Program.

PubMed

Wade, Terry L; Sweet, Stephen T; Sericano, José L; Defreitas, Debra A; Lauenstein, Gunnar G

2014-04-30

Bivalve samples from 142 sites were analyzed to determine the concentration and toxicity equivalents (TEQ) of dioxins and furans (D/F) as part of the NOAA National Status and Trends Program. The total concentration of 17 D/F ranged from not detected to 203 pg/g wet weight of tissue. Octachlorinated dibenzo-p-dioxin, OCDD, had a concentration range from not detected to 189 pg/g and a mean concentration of 8.65 pg/g. OCDD was the dominant D/F compound detected and accounted for, on average, over 70% of the total D/F concentration. The TEQ (compared to 2,3,7,8-TCDD) ranged from 0.12 to 7.32 pg TEQ/g. The TEQ for 39% of the bivalves analyzed were below 0.238 pg TEQ/g. TEQ above human consumption advisory concentration of 1.2 pg TEQ/g were found in 9.3% of the samples analyzed. TEQ for D/F indicate very limited human health concerns from consumption of bivalves at most of the locations sampled. Copyright © 2013 Elsevier Ltd. All rights reserved.

The KMOS3D Survey: Rotating Compact Star-forming Galaxies and the Decomposition of Integrated Line Widths

NASA Astrophysics Data System (ADS)

Wisnioski, E.; Mendel, J. T.; Förster Schreiber, N. M.; Genzel, R.; Wilman, D.; Wuyts, S.; Belli, S.; Beifiori, A.; Bender, R.; Brammer, G.; Chan, J.; Davies, R. I.; Davies, R. L.; Fabricius, M.; Fossati, M.; Galametz, A.; Lang, P.; Lutz, D.; Nelson, E. J.; Momcheva, I.; Rosario, D.; Saglia, R.; Tacconi, L. J.; Tadaki, K.; Übler, H.; van Dokkum, P. G.

2018-03-01

Using integral field spectroscopy, we investigate the kinematic properties of 35 massive centrally dense and compact star-forming galaxies (SFGs; {log}{\\overline{M}}* [{M}ȯ ]=11.1, {log}({{{Σ }}}1{kpc}[{M}ȯ {kpc}}-2])> 9.5, {log}({M}* /{r}e1.5[{M}ȯ {kpc}}-1.5])> 10.3) at z ∼ 0.7–3.7 within the KMOS3D survey. We spatially resolve 23 compact SFGs and find that the majority are dominated by rotational motions with velocities ranging from 95 to 500 km s‑1. The range of rotation velocities is reflected in a similar range of integrated Hα line widths, 75–400 km s‑1, consistent with the kinematic properties of mass-matched extended galaxies from the full KMOS3D sample. The fraction of compact SFGs that are classified as “rotation-dominated” or “disklike” also mirrors the fractions of the full KMOS3D sample. We show that integrated line-of-sight gas velocity dispersions from KMOS3D are best approximated by a linear combination of their rotation and turbulent velocities with a lesser but still significant contribution from galactic-scale winds. The Hα exponential disk sizes of compact SFGs are, on average, 2.5 ± 0.2 kpc, 1–2× the continuum sizes, in agreement with previous work. The compact SFGs have a 1.4× higher active galactic nucleus (AGN) incidence than the full KMOS3D sample at fixed stellar mass with an average AGN fraction of 76%. Given their high and centrally concentrated stellar masses, as well as stellar-to-dynamical mass ratios close to unity, the compact SFGs are likely to have low molecular gas fractions and to quench on a short timescale unless replenished with inflowing gas. The rotation in these compact systems suggests that their direct descendants are rotating passive galaxies. Based on observations obtained at the Very Large Telescope (VLT) of the European Southern Observatory (ESO), Paranal, Chile (ESO program IDs 092A-0091, 093.A-0079, 094.A-0217, 095.A-0047, 096.A-0025, 097.A-0028, and 098.A-0045).

Evidence for chronic stress in captive but not free-ranging cheetahs (Acinonyx jubatus) based on adrenal morphology and function.

PubMed

Terio, Karen A; Marker, Laurie; Munson, Linda

2004-04-01

The cheetah (Acinonyx jubatus) is highly endangered because of loss of habitat in the wild and failure to thrive in captivity. Cheetahs in zoos reproduce poorly and have high prevalences of unusual diseases that cause morbidity and mortality. These diseases are rarely observed in free-ranging cheetahs but have been documented in cheetahs that have been captured and held in captive settings either temporarily or permanently. Because captivity may be stressful for this species and stress is suspected as contributing to poor health and reproduction, this study aimed to measure chronic stress by comparing baseline concentrations of fecal corticoid metabolites and adrenal gland morphology between captive and free-ranging cheetahs. Additionally, concentrations of estradiol and testosterone metabolites were quantified to determine whether concentrations of gonadal steroids correlated with corticoid concentration and to assure that corticosteroids in the free-ranging samples were not altered by environmental conditions. Concetntrations of fecal corticoids, estradiol, and testosterone were quantified by radioimmunoassay in 20 free-ranging and 20 captive cheetahs from samples collected between 1994 and 1999. Concentrations of baseline fecal corticoids were significantly higher (p = 0.005) in captive cheetahs (196.08 +/- 36.20 ng/g dry feces) than free-ranging cheetahs (71.40 +/- 14.35 ng/g dry feces). Testosterone concentrations were lower in captive male cheetahs (9.09 +/- 2.84 ng/g dry feces) than in free-ranging cheetahs (34.52 +/- 12.11 ng/g dry feces), which suggests suppression by elevated corticoids in the captive males. Evidence for similar sulppression of estradiol concentrations in females was not present. Adrenal corticomedullary ratios were determined on midsagittal sections of adrenal glands from 13 free-ranging and 13 captive cheetahs obtained between 1991 and 2002. The degree of vacuolation of cortical cells in the zona fasciculata was graded for each animal. Corticomedullary ratios were larger (p = 0.05) in captive cheetahs; however, there was no difference (p = 0.31) in the degree of corticocyte vacnolation between the two populations. These data proxile both mnorphologic and functional evidence suggestive of chronic stress in captive cheetahs. Further research into the role of hypercortisolemia in the pathogenesis of the reproductive abnormalities and unusual diseases of captive cheetahs is needed.

Determination of Cefalothin and Cefazolin in Human Plasma, Urine and Peritoneal Dialysate by UHPLC-MS/MS: application to a pilot pharmacokinetic study in humans.

PubMed

Parker, Suzanne L; Guerra Valero, Yarmarly C; Roberts, Darren M; Lipman, Jeffrey; Roberts, Jason A; Wallis, Steven C

2016-06-01

An ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method for the analysis of cefazolin and cefalothin in human plasma (total and unbound), urine and peritoneal dialysate has been developed and validated. Total plasma concentrations are measured following protein precipitation and are suitable for the concentration range of 1-500 µg/mL. Unbound concentrations are measured from ultra-filtered plasma acquired using Centrifree(®) devices and are suitable for the concentration range of 0.1-500 µg/mL for cefazolin and 1-500 µg/mL for cefalothin. The urine method is suitable for a concentration range of 0.1-20 mg/mL for cefazolin and 0.2-20 mg/mL for cefalothin. Peritoneal dialysate concentrations are measured using direct injection, and are suitable for the concentration range of 0.2-100 µg/mL for both cefazolin and cefalothin. The cefazolin and cefalothin plasma (total and unbound), urine and peritoneal dialysate results are reported for recovery, inter-assay precision and accuracy, and the lower limit of quantification, linearity, stability and matrix effects, with all results meeting acceptance criteria. The method was used successfully in a pilot pharmacokinetic study with patients with peritoneal dialysis-associated peritonitis, receiving either intraperitoneal cefazolin or cefalothin. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

Dissolved Organophosphate Esters and Polybrominated Diphenyl Ethers in Remote Marine Environments: Arctic Surface Water Distributions and Net Transport through Fram Strait.

PubMed

McDonough, Carrie A; De Silva, Amila O; Sun, Caoxin; Cabrerizo, Ana; Adelman, David; Soltwedel, Thomas; Bauerfeind, Eduard; Muir, Derek C G; Lohmann, Rainer

2018-06-05

Organophosphate esters (OPEs) have been found in remote environments at unexpectedly high concentrations, but very few measurements of OPE concentrations in seawater are available, and none are available in subsurface seawater. In this study, passive polyethylene samplers (PEs) deployed on deep-water moorings in the Fram Strait and in surface waters of Canadian Arctic lakes and coastal sites were analyzed for a suite of common OPEs. Total OPEs ( ∑ 11 OPE) at deep-water sites were dominated by chlorinated OPEs, and ranged from 6.3 to 440 pg/L. Concentrations were similar in eastern and western Fram Strait. Chlorinated OPEs were also dominant in Canadian Arctic surface waters (mean concentration ranged from < DL to 4400 pg/L), while nonhalogenated alkyl/aryl-substituted OPEs remained low (1.3-55 pg/L), possibly due to the greater long-range transport potential of chlorinated OPEs. Polybrominated diphenyl ethers (PBDEs) were found at much lower concentrations than OPEs (

Estimation of optimal concentration of fluoride in drinking water under conditions prevailing in Chile.

PubMed

Villa, A E; Guerrero, S; Villalobos, J

1998-08-01

The purpose of this comparative study of caries and dental fluorosis experience in Chilean children was to estimate the optimal range of fluoride concentration in tap water under conditions currently prevailing in Chile. The sample included 2431 schoolchildren 7, 12 and 15 years old, life-long residents of five communities with fluoride concentrations in their tap water in the range 0.07-1.1 mg/L. The study population received an oral clinical examination including caries experience and an enamel fluorosis evaluation of the permanent dentition (Dean's scoring system). For 15-year-old children, the DMFT index changed from 5.06 to 2.60, and for 12-year-olds it changed from 3.10 to 1.36 when fluoride water concentration changed from 0.07 to 1.10 mg/L. For 7-year-old children the dmft index correspondingly changed from 3.67 to 1.59. The relationship between DMFT for 12-year-olds and water fluoride concentration was best fitted by a logarithmic function (r2=0.98). The Community Fluorosis Index (CFI) was used to assess enamel fluorosis in the study population, and it showed a linear relationship (r2=0.983) with increasing fluoride concentration of water for the 12-year-old group. Results obtained suggest that under current Chilean conditions, the optimal range of fluoride concentration in potable water should lie in the 0.5-0.6 mg/L range.

Long-range electrostatic screening in ionic liquids

PubMed Central

Gebbie, Matthew A.; Dobbs, Howard A.; Valtiner, Markus; Israelachvili, Jacob N.

2015-01-01

Electrolyte solutions with high concentrations of ions are prevalent in biological systems and energy storage technologies. Nevertheless, the high interaction free energy and long-range nature of electrostatic interactions makes the development of a general conceptual picture of concentrated electrolytes a significant challenge. In this work, we study ionic liquids, single-component liquids composed solely of ions, in an attempt to provide a novel perspective on electrostatic screening in very high concentration (nonideal) electrolytes. We use temperature-dependent surface force measurements to demonstrate that the long-range, exponentially decaying diffuse double-layer forces observed across ionic liquids exhibit a pronounced temperature dependence: Increasing the temperature decreases the measured exponential (Debye) decay length, implying an increase in the thermally driven effective free-ion concentration in the bulk ionic liquids. We use our quantitative results to propose a general model of long-range electrostatic screening in ionic liquids, where thermally activated charge fluctuations, either free ions or correlated domains (quasiparticles), take on the role of ions in traditional dilute electrolyte solutions. This picture represents a crucial step toward resolving several inconsistencies surrounding electrostatic screening and charge transport in ionic liquids that have impeded progress within the interdisciplinary ionic liquids community. More broadly, our work provides a previously unidentified way of envisioning highly concentrated electrolytes, with implications for diverse areas of inquiry, ranging from designing electrochemical devices to rationalizing electrostatic interactions in biological systems. PMID:26040001

Individual and environmental risk factors for high blood lead concentrations in Danish indoor shooters.

PubMed

Grandahl, Kasper; Suadicani, Poul; Jacobsen, Peter

2012-08-01

International studies have shown blood lead at levels causing health concern in recreational indoor shooters. We hypothesized that Danish recreational indoor shooters would also have a high level of blood lead, and that this could be explained by shooting characteristics and the physical environment at the shooting range. This was an environmental case study of 58 male and female shooters from two indoor shooting ranges with assumed different ventilation and cleaning conditions. Information was obtained on general conditions including age, gender, tobacco and alcohol use, and shooting conditions: weapon type, number of shots fired, frequency of stays at the shooting range and hygiene habits. A venous blood sample was drawn to determine blood lead concentrations; 14 non-shooters were included as controls. Almost 60% of the shooters, hereof five out of 14 women, had a blood lead concentration above 0.48 micromol/l, a level causing long-term health concern. All controls had blood lead values below 0.17 micromol/l. Independent significant associations with blood lead concentrations above 0.48 micromol/l were found for shooting at a poorly ventilated range, use of heavy calibre weapons, number of shots and frequency of stays at the shooting range. A large proportion of Danish recreational indoor shooters had potentially harmful blood lead concentrations. Ventilation, amounts of shooting, use of heavy calibre weapons and stays at the shooting ranges were independently associated with increased blood lead. The technical check at the two ranges was performed by the Danish Technological Institute and costs were defrayed by the Danish Rifle Association. To pay for the analyses of blood lead, the study was supported by the The Else & Mogens Wedell-Wedellsborg Foundation. The Danish Regional Capital Scientific Ethics Committee approved the study, protocol number H-4-2010-130.

On the electronic properties of GaSb irradiated with reactor neutrons and its charge neutrality level

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

Boiko, V. M.; Brudnii, V. N., E-mail: brudnyi@mail.tsu.ru; Ermakov, V. S.

2015-06-15

The electronic properties and the limiting position of the Fermi level in p-GaSb crystals irradiated with full-spectrum reactor neutrons at up to a fluence of 8.6 × 10{sup 18} cm{sup −2} are studied. It is shown that the irradiation of GaSb with reactor neutrons results in an increase in the concentration of free holes to p{sub lim} = (5−6) × 10{sup 18} cm{sup −3} and in pinning of the Fermi level at the limiting position F{sub lim} close to E{sub V} + 0.02 eV at 300 K. The effect of the annealing of radiation defects in the temperature range 100–550°Cmore » is explored.« less

Hair and toenail arsenic concentrations of residents living in areas with high environmental arsenic concentrations.

PubMed Central

Hinwood, Andrea L; Sim, Malcolm R; Jolley, Damien; de Klerk, Nick; Bastone, Elisa B; Gerostamoulos, Jim; Drummer, Olaf H

2003-01-01

Surface soil and groundwater in Australia have been found to contain high concentrations of arsenic. The relative importance of long-term human exposure to these sources has not been established. Several studies have investigated long-term exposure to environmental arsenic concentrations using hair and toenails as the measure of exposure. Few have compared the difference in these measures of environmental sources of exposure. In this study we aimed to investigate risk factors for elevated hair and toenail arsenic concentrations in populations exposed to a range of environmental arsenic concentrations in both drinking water and soil as well as in a control population with low arsenic concentrations in both drinking water and soil. In this study, we recruited 153 participants from areas with elevated arsenic concentrations in drinking water and residential soil, as well as a control population with no anticipated arsenic exposures. The median drinking water arsenic concentrations in the exposed population were 43.8 micro g/L (range, 16.0-73 micro g/L) and median soil arsenic concentrations were 92.0 mg/kg (range, 9.1-9,900 mg/kg). In the control group, the median drinking water arsenic concentration was below the limit of detection, and the median soil arsenic concentration was 3.3 mg/kg. Participants were categorized based on household drinking water and residential soil arsenic concentrations. The geometric mean hair arsenic concentrations were 5.52 mg/kg for the drinking water exposure group and 3.31 mg/kg for the soil exposure group. The geometric mean toenail arsenic concentrations were 21.7 mg/kg for the drinking water exposure group and 32.1 mg/kg for the high-soil exposure group. Toenail arsenic concentrations were more strongly correlated with both drinking water and soil arsenic concentrations; however, there is a strong likelihood of significant external contamination. Measures of residential exposure were better predictors of hair and toenail arsenic concentrations than were local environmental concentrations. PMID:12573904

Evaluation of the Stability of Concentrated Emulsions for Lemon Beverages Using Sequential Experimental Designs

PubMed Central

Almeida, Teresa Cristina Abreu; Larentis, Ariane Leites; Ferraz, Helen Conceição

2015-01-01

The study of the stability of concentrated oil-in-water emulsions is imperative to provide a scientific approach for an important problem in the beverage industry, contributing to abolish the empiricism still present nowadays. The use of these emulsions would directly imply a reduction of transportation costs between production and the sales points, where dilution takes place. The goal of this research was to evaluate the influence of the main components of a lemon emulsion on its stability, aiming to maximize the concentration of oil in the beverage and to correlate its physicochemical characteristics to product stability, allowing an increase of shelf life of the final product. For this purpose, analyses of surface and interface tension, electrokinetic potential, particle size and rheological properties of the emulsions were conducted. A 24-1 fractional factorial design was performed with the following variables: lemon oil/water ratio (30% to 50%), starch and Arabic gum concentrations (0% to 30%) and dioctyl sodium sulfosuccinate (0 mg/L to 100 mg/L), including an evaluation of the responses at the central conditions of each variable. Sequentially, a full design was prepared to evaluate the two most influential variables obtained in the first plan, in which concentration of starch and gum ranged from 0% to 20%, while concentration of lemon oil/water ratio was fixed at 50%, without dioctyl sodium sulfosuccinate. Concentrated emulsions with stability superior to 15 days were obtained with either starch or Arabic gum and 50% lemon oil. The most stable formulations presented viscosity over 100 cP and ratio between the surface tension of the emulsion and the mucilage of over 1. These two answers were selected, since they better represent the behavior of emulsions in terms of stability and could be used as tools for an initial selection of the most promising formulations. PMID:25793301

Resistance exercise prevents plantar flexor deconditioning during bed rest

NASA Technical Reports Server (NTRS)

Bamman, M. M.; Hunter, G. R.; Stevens, B. R.; Guilliams, M. E.; Greenisen, M. C.

1997-01-01

Because resistance exercise (REX) and unloading induce opposing neuromuscular adaptations, we tested the efficacy of REX against the effects of 14 d of bed rest unloading (BRU) on the plantar flexor muscle group. Sixteen men were randomly assigned to no exercise (NOE, N = 8) or REX (N = 8). REX performed 5 sets x 6-10 repetitions to failure of constant resistance concentric/eccentric plantar flexion every other day during BRU. One-repetition maximum (1RM) strength was tested on the training device. The angle-specific torque-velocity relationship across 5 velocities (0, 0.52, 1.05, 1.75, and 2.97 rad.s-1) and the full range-of-motion power-velocity relationship were assessed on a dynamometer. Torque-position analyses identified strength changes at shortened, neutral, and stretched muscle lengths. Concentric and eccentric contractile work were measured across ten repetitions at 1.05 rad.s-1. Maximal neural activation was measured by surface electromyography (EMG). 1RM decreased 9% in NOE and improved 11% in REX (P < 0.05). Concentric (0.52 and 1.05 rad.s-1), eccentric (0.52 and 2.97 rad.s-1), and isometric angle-specific torques decreased (P < 0.05) in NOE, averaging 18%, 17%, and 13%, respectively. Power dropped (P < 0.05) in NOE at three eccentric (21%) and two concentric (14%) velocities. REX protected angle-specific torque and average power at all velocities. Concentric and eccentric strength decreased at stretched (16%) and neutral (17%) muscle lengths (P < 0.05) in NOE while REX maintained or improved strength at all joint positions. Concentric (15%) and eccentric (11%) contractile work fell in NOE (P < 0.05) but not in REX. Maximal plantar flexor EMG did not change in either group. In summary, constant resistance concentric/eccentric REX completely prevented plantar flexor performance deconditioning induced by BRU. The reported benefits of REX should prove useful in prescribing exercise for astronauts in microgravity and for patients susceptible to functional decline during bed- or chair-bound hospital stays.

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

Hwang, Y; Lin, Y; Tsai, C

Purpose: The objective of this study is to develop quantitative calibration between image quality indexes and iodine concentration with dual-energy (DE) contrast-enhanced digital mammography (CEDM) techniques and further serve as the assistance for diagnosis. Methods: Custom-made acrylic phantom with dimensions of 24×30 cm{sup 2} simulated breast thickness from 2 to 6 cm was used in the calibration. The phantom contained matrix of four times four holes of 3 mm deep with a diameter of 15 mm for filling contrast agent with area density ranged from 0.1 to 10 mg/cm{sup 2}. All the image acquisitions were performed on a full-field digitalmore » mammography system (Senographe Essential, GE) with dual energy acquisitions. Mean pixel value (MPV), and contrast-to-noise ratio (CNR) were used for evaluating the relationship between image quality indexes and iodine concentration. Iodine map and CNR map could further be constructed with these calibration curves applied pixel by pixel utilized MATLAB software. Minimum iodine concentration could also be calculated with the visibility threshold of CNR=5 according the Rose model. Results: When evaluating the DE subtraction images, MPV increased linearly as the iodine concentration increased with all the phantom thickness surveyed (R{sup 2} between 0.989 and 0.992). Lesions with increased iodine uptake could thus be enhanced in the color-encoded iodine maps, and the mean iodine concentration could be obtained through the ROI measurements. As for investigating CNR performance, linear relationships were also shown between the iodine concentration and CNR (R{sup 2} between 0.983 and 0.990). Minimum iodine area density of 1.45, 1.73, 1.80, 1.73 and 1.72 mg/cm{sup 2} for phantom thickness of 2, 3, 4, 5, 6 cm were calculated based on Rose’s visualization criteria. Conclusion: Quantitative calibration between image quality indexes and iodine concentrations may further serving as the assistance for analyzing contrast enhancement for patient participating the dual energy CEDM procedures.« less

Airborne concentrations of PM(2.5) and diesel exhaust particles on Harlem sidewalks: a community-based pilot study.

PubMed

Kinney, P L; Aggarwal, M; Northridge, M E; Janssen, N A; Shepard, P

2000-03-01

Residents of the dense urban core neighborhoods of New York City (NYC) have expressed increasing concern about the potential human health impacts of diesel vehicle emissions. We measured concentrations of particulate matter [less than/equal to] 2.5 micro in aerodynamic diameter (PM(2.5)) and diesel exhaust particles (DEP) on sidewalks in Harlem, NYC, and tested whether spatial variations in concentrations were related to local diesel traffic density. Eight-hour (1000-1800 hr) air samples for PM(2.5 )and elemental carbon (EC) were collected for 5 days in July 1996 on sidewalks adjacent to four geographically distinct Harlem intersections. Samples were taken using portable monitors worn by study staff. Simultaneous traffic counts for diesel trucks, buses, cars, and pedestrians were carried out at each intersection on [Greater/equal to] 2 of the 5 sampling days. Eight-hour diesel vehicle counts ranged from 61 to 2,467 across the four sites. Mean concentrations of PM(2.5) exhibited only modest site-to-site variation (37-47 microg/m(3)), reflecting the importance of broader regional sources of PM(2.5). In contrast, EC concentrations varied 4-fold across sites (from 1.5 to 6 microg/m(3)), and were associated with bus and truck counts on adjacent streets and, at one site, with the presence of a bus depot. A high correlation (r = 0.95) was observed between EC concentrations measured analytically and a blackness measurement based on PM(2.5) filter reflectance, suggesting the utility of the latter as a surrogate measure of DEP in future community-based studies. These results show that local diesel sources in Harlem create spatial variations in sidewalk concentrations of DEP. The study also demonstrates the feasibility of a new paradigm for community-based research involving full and active partnership between academic scientists and community-based organizations.

Three fatalities associated with the synthetic cannabinoids 5F-ADB, 5F-PB-22, and AB-CHMINACA.

PubMed

Angerer, V; Jacobi, S; Franz, F; Auwärter, V; Pietsch, J

2017-12-01

The use of synthetic cannabinoids (SC) has been widespread in certain groups of drug users for many years. In the scientific literature many intoxication cases and a number of fatalities after the use of synthetic cannabinoids were reported. In this paper three death cases are described with involvement of the synthetic cannabinoids 5F-PB-22, AB-CHMINACA, and 5F-ADB. The three cases occurred in the eastern region of Germany, which is known as a region of high methamphetamine abuse. All decedents were male, between 25 and 41 years old, and had a known history of drug use. Femoral blood concentrations of the synthetic cannabinoids were measured using a validated LC-MS/MS method. The concentration of 5F-PB-22 in the first case was 0.37ng/mL, the concentration of AB-CHMINACA in the second case was approximately 4.1ng/mL (extrapolated) and the 5F-ADB concentration in the third case was 0.38ng/mL. Compared to other published cases the concentrations in the here presented cases seem to be in the lower range. However, taking into account the scene of death, the results of the forensic autopsy and the full toxicological analysis, the deaths can be explained as a direct consequence of consumption of synthetic cannabinoids, although in case one and two relevant amounts of ethanol were found, and in case three trimipramine and olanzapine were present in non-toxic concentrations. It has to be noted that concentrations of synthetic cannabinoids in femoral blood cannot directly be judged as toxic or lethal due to the possibility of postmortem redistribution and the development of tolerance after frequent use. Therefore, all available information has to be considered carefully before stating SC use as the cause of death. Copyright © 2017 Elsevier B.V. All rights reserved.

Evaluation of the stability of concentrated emulsions for lemon beverages using sequential experimental designs.

PubMed

Almeida, Teresa Cristina Abreu; Larentis, Ariane Leites; Ferraz, Helen Conceição

2015-01-01

The study of the stability of concentrated oil-in-water emulsions is imperative to provide a scientific approach for an important problem in the beverage industry, contributing to abolish the empiricism still present nowadays. The use of these emulsions would directly imply a reduction of transportation costs between production and the sales points, where dilution takes place. The goal of this research was to evaluate the influence of the main components of a lemon emulsion on its stability, aiming to maximize the concentration of oil in the beverage and to correlate its physicochemical characteristics to product stability, allowing an increase of shelf life of the final product. For this purpose, analyses of surface and interface tension, electrokinetic potential, particle size and rheological properties of the emulsions were conducted. A 2(4-1) fractional factorial design was performed with the following variables: lemon oil/water ratio (30% to 50%), starch and Arabic gum concentrations (0% to 30%) and dioctyl sodium sulfosuccinate (0 mg/L to 100 mg/L), including an evaluation of the responses at the central conditions of each variable. Sequentially, a full design was prepared to evaluate the two most influential variables obtained in the first plan, in which concentration of starch and gum ranged from 0% to 20%, while concentration of lemon oil/water ratio was fixed at 50%, without dioctyl sodium sulfosuccinate. Concentrated emulsions with stability superior to 15 days were obtained with either starch or Arabic gum and 50% lemon oil. The most stable formulations presented viscosity over 100 cP and ratio between the surface tension of the emulsion and the mucilage of over 1. These two answers were selected, since they better represent the behavior of emulsions in terms of stability and could be used as tools for an initial selection of the most promising formulations.

River Induced Wellbore Flow Dynamics in Long-Screen Wells and their Impact on Aqueous Sampling Results

NASA Astrophysics Data System (ADS)

Vermeul, V.; McKinley, J. P.; Newcomer, D.; Fritz, B. G.; Mackley, R.; Zachara, J. M.

2010-12-01

Previously published field investigations and modeling studies have demonstrated the potential for sample bias associated with vertical wellbore flow in conventional monitoring wells constructed with long-screened intervals. In this study, simultaneous measurement of 1) wellbore flow using an electromagnetic borehole flowmeter (EBF), 2) depth discrete hydraulic head, and 3) aqueous uranium concentrations were used to quantify wellbore flow and assess the associated impacts on measured aqueous concentrations. Monitoring results demonstrate the utility of continuous (i.e., hourly measurements for ~ one month) ambient wellbore flow monitoring and show that relatively large wellbore flows (up to 4 LPM) can be induced by aquifer hydrodynamics associated with a fluctuating river boundary located approximately 250 m from the test well. The observed vertical wellbore flows were strongly correlated with fluctuations in river stage, alternating between upward and downward flow throughout the monitoring period in response to changes in river stage. Continuous monitoring of ambient wellbore flows using an EBF system allowed these effects to be evaluated in concert with continuously monitored river stage elevations (hourly) and aqueous uranium concentrations (daily) in a long-screen well and an adjacent multi-level well cluster. This study demonstrates that when contaminant concentrations within the aquifer vary significantly over the depth interval interrogated, river-induced vertical wellbore flow can result in variations in measured concentration that nearly encompass the full range of variation in aquifer contaminant concentration with depth. In addition, observed variability in aqueous concentrations measured during active tracer transport experiments provided additional evidence of wellbore flow impacts and showed that the magnitude and direction of wellbore flow varied spatially across the wellfield. An approach to mitigate these effects based on increasing hydraulic resistance within the wellbore was evaluated. This research is part of the ERSP Hanford IFRC at Pacific Northwest National Laboratory.

Cleaved Form of Osteopontin in Urine as a Clinical Marker of Lupus Nephritis

PubMed Central

Kitagori, Koji; Yoshifuji, Hajime; Oku, Takuma; Sasaki, Chiyomi; Miyata, Hitomi; Mori, Keita P.; Nakajima, Toshiki; Ohmura, Koichiro; Kawabata, Daisuke; Yukawa, Naoichiro; Imura, Yoshitaka; Murakami, Kosaku; Nakashima, Ran; Usui, Takashi; Fujii, Takao; Sakai, Kaoru; Yanagita, Motoko; Hirayama, Yoshitaka; Mimori, Tsuneyo

2016-01-01

We assessed the utility of two forms of osteopontin (OPN), OPN full and its cleaved form (OPN N-half), in plasma and urine as markers of disease activity in lupus nephritis (LN). Samples were collected from patients with systemic lupus erythematosus (SLE) (LN: N = 29, non-LN: N = 27), IgA nephropathy (IgAN) (N = 14), minimal change nephrotic syndrome (MCNS) (N = 5), diabetic nephropathy (DN) (N = 14) and healthy volunteers (HC) (N = 17). While there was no significant difference in urine OPN full concentration between groups, urine OPN N-half concentration was significantly higher in patients with LN than HC (p < 0.05). Moreover, urine OPN N-half was higher in LN patients with overt proteinuria (urine protein/creatinine ratio: P/C > 0.5) than LN patients with minimal proteinuria (P/C < 0.5, p < 0.0001), and also higher than in DN patients with overt proteinuria (P/C > 0.5, p < 0.01). Urine thrombin activity correlated with urine OPN N-half concentration (p < 0.0001), but not with urine OPN full concentration. These results suggest that urine OPN N-half concentration reflects renal inflammation. Thus, urine OPN N-half may be a novel disease activity marker for LN. PMID:27992535

Evaluation of exposure to airborne heavy metals at gun shooting ranges.

PubMed

Lach, Karel; Steer, Brian; Gorbunov, Boris; Mička, Vladimír; Muir, Robert B

2015-04-01

Aerosols formed during shooting events were studied with various techniques including the wide range size resolving sampling system Nano-ID(®) Select, followed by inductively coupled plasma mass spectrometry chemical analysis, scanning electron microscopy, and fast mobility particle sizing. The total lead mass aerosol concentration ranged from 2.2 to 72 µg m(-3). It was shown that the mass concentration of the most toxic compound lead is much lower than the total mass concentration. The deposition fraction in various compartments of the respiratory system was calculated using the ICRP lung deposition model. It was found that the deposition fraction in the alveolar range varies by a factor >3 for the various aerosols collected, depending on the aerosol size distribution and total aerosol concentration, demonstrating the importance of size resolved sampling in health risk evaluation. The proportion of the total mass of airborne particles deposited in the respiratory tract varies from 34 to 70%, with a median of 55.9%, suggesting the health risk based upon total mass significantly overestimates the accumulated dose and therefore the health risk. A comparison between conventional and so called 'green' ammunition confirmed significant lowering of concentrations of lead and other toxic metals like antimony in the atmosphere of indoor shooting ranges using 'green' ammunition, although higher concentrations of manganese and boron were measured. These metals are likely to be the constituents of new types of primers. They occur predominantly in the size fraction <250 nm of aerosols. © The Author 2014. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.

Fluoride Content of Bottled Waters in Hong Kong and Qatar.

PubMed

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

2016-01-01

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

Suspended sediment transport in an estuarine tidal channel within San Francisco Bay, California

USGS Publications Warehouse

Sternberg, R.W.; Cacchione, D.A.; Drake, D.E.; Kranck, K.

1986-01-01

Size distributions of the suspended sediment samples, estimates of particle settling velocity (??s), friction velocity (U*), and reference concentration (Ca) at z = 20 cm were used in the suspended sediment distribution equations to evaluate their ability to predict the observed suspended sediment profiles. Three suspended sediment particle conditions were evaluated: (1) individual particle sizes in the 4-11 ?? (62.5-0.5 ??m) size range with the reference concentration Ca at z = 20 cm (C??); (2) individual particle sizes in the 4-6 ?? size range, flocs representing the 7-11 ?? size range with the reference concentration Ca at z = 20 cm (Cf); and (3) individual particle sizes in the 4-6 ?? size range, flocs representing the 7-11 ?? size range with the reference concentration predicted as a function of the bed sediment size distribution and the square of the excess shear stress. An analysis was also carried out on the sensitivity of the suspended sediment distribution equation to deviations in the primary variables ??s, U*, and Ca. In addition, computations of mass flux were made in order to show vertical variations in mass flux for varying flow conditions. ?? 1986.

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

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

Hay, M. S.

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

Mass transport in polyelectrolyte solutions

NASA Astrophysics Data System (ADS)

Schipper, F. J. M.; Leyte, J. C.

1999-02-01

The self-diffusion coefficients of the three components of a salt-free heavy-water solution of polymethacrylic acid, completely neutralized with tetra-methylammonium hydroxide, were measured over a broad concentration range. Three concentration regions were observed for the self-diffusion of both the polyions and the counterions. At polyion concentrations below 0.01 mol monomer kg-1, the dilute concentration regime for the polymer, the polyion self-diffusion coefficient approaches the self-diffusion coefficient of a freely diffusing rod upon dilution. At polyelectrolyte concentrations above 0.1 mol monomer kg-1, the self-diffusion coefficients of the solvent, the counterions and the polymer decreased with concentration, suggesting that this decrease is due to a topological constraint on the motions of the components. In the intermediate-concentration region, the self-diffusion coefficients of the polyions and the counterions are independent of the concentration. The polyion dynamic behaviour is, in the intermediate- and high-concentration regions, reasonably well described by that of a hard sphere, with a radius of 3.7 nm. A correct prediction for the solvent dynamics is given by the obstruction effect of this hard sphere on the solvent. The relative counterion self-diffusion coefficient is predicted almost quantitatively over the entire concentration range with the Poisson-Boltzmann-Smoluchowski model for the spherical cell, provided that the sphere radius and the number of charges are chosen appropriately (approximately the number of charges in a persistence length). Using this model, the dependence of the counterion self-diffusion coefficient on the ionic strength, polyion concentration and counterion radius is calculated quantitatively over a large concentration range.

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

USGS Publications Warehouse

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

1998-01-01

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

Wide-range radioactive-gas-concentration detector

DOEpatents

Anderson, D.F.

1981-11-16

A wide-range radioactive-gas-concentration detector and monitor capable of measuring radioactive-gas concentrations over a range of eight orders of magnitude is described. The device is designed to have an ionization chamber sufficiently small to give a fast response time for measuring radioactive gases but sufficiently large to provide accurate readings at low concentration levels. Closely spaced parallel-plate grids provide a uniform electric field in the active region to improve the accuracy of measurements and reduce ion migration time so as to virtually eliminate errors due to ion recombination. The parallel-plate grids are fabricated with a minimal surface area to reduce the effects of contamination resulting from absorption of contaminating materials on the surface of the grids. Additionally, the ionization-chamber wall is spaced a sufficient distance from the active region of the ionization chamber to minimize contamination effects.

Dynamic Control of Adsorption Sensitivity for Photo-EMF-Based Ammonia Gas Sensors Using a Wireless Network

PubMed Central

Vashpanov, Yuriy; Choo, Hyunseung; Kim, Dongsoo Stephen

2011-01-01

This paper proposes an adsorption sensitivity control method that uses a wireless network and illumination light intensity in a photo-electromagnetic field (EMF)-based gas sensor for measurements in real time of a wide range of ammonia concentrations. The minimum measurement error for a range of ammonia concentration from 3 to 800 ppm occurs when the gas concentration magnitude corresponds with the optimal intensity of the illumination light. A simulation with LabView-engineered modules for automatic control of a new intelligent computer system was conducted to improve measurement precision over a wide range of gas concentrations. This gas sensor computer system with wireless network technology could be useful in the chemical industry for automatic detection and measurement of hazardous ammonia gas levels in real time. PMID:22346680

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

USGS Publications Warehouse

Stensvold, Krista A.

2012-01-01

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

Cerebrospinal fluid maraviroc concentrations in HIV-1 infected patients.

PubMed

Yilmaz, Aylin; Watson, Victoria; Else, Laura; Gisslèn, Magnus

2009-11-27

In order to assess the penetration of maraviroc to the central nervous system, we measured maraviroc concentrations in cerebrospinal fluid (CSF) and plasma. Concentrations were determined by liquid chromatography tandem mass spectrometry (lower limit of quantitation 1.25 ng/ml) in seven paired CSF and plasma samples. The median plasma maraviroc concentration was 94.9 ng/ml (range 21.4-478.0) and the median CSF concentration was 3.63 ng/ml (range 1.83-12.2). CSF samples exceeded the median EC90 for maraviroc (0.57 ng/ml) by at least three-fold. The CSF levels of maraviroc found in this study likely contribute to viral suppression in the CSF.

A study of elastic and plastic stress concentration factors due to notches and fillets in flat plates

NASA Technical Reports Server (NTRS)

Hardrath, Herbert F; Ohman, Lachlan

1953-01-01

Six large 24s-t3 aluminum-alloy-sheet specimens containing various notches or fillets were tested in tension to determine their stress concentration factors in both the elastic and plastic ranges. The elastic stress concentration factors were found to be slightly higher than those calculated by Neuber's method and those obtained photoelastically by Frocht. The results showed further that the stress concentration factor decreases as strains at the discontinuity enter the plastic range. A generalization of Stowell's relation for the plastic stress concentration factor at a circular hole in an infinite plate was applied to the specimen shapes tested and gave good agreement with test results.

Formaldehyde Exposures in a University Anatomy Laboratory

NASA Astrophysics Data System (ADS)

Winkler, Kyle William

Air sampling studies were conducted within a university anatomical laboratory during the embalmment of a cadaver in order to determine if dangerous concentrations of formaldehyde existed. Three air sampling studies were conducted in the anatomical laboratory on three separate days that a cadaver was being embalmed. Samples were collected and analyzed using the Occupational Safety and Health Administration (OSHA) Sampling and Analytical Methods: Method 52. Each air sampling study sampled for short term exposure limit (STEL) and time weighted mean (TWA) breathing zone formaldehyde concentrations as well as area TWA formaldehyde concentrations. A personal aldehyde monitor was also used in each air sampling study to sample for breathing zone formaldehyde concentrations. Measured TWA mean exposures to formaldehyde ranged from 0.15--1.3 parts per million (ppm), STEL formaldehyde exposures ranged from 0.019--0.64 ppm, and eight-hour TWAs ranged from 0.03 to 3.6 ppm. All 8-hour TWA formaldehyde concentrations sampled in the anatomy laboratory during an embalmment were less than the permissible exposure limit (PEL) required by OSHA.

Minerals, vitamin C, phenolics, flavonoids and antioxidant activity of Amaranthus leafy vegetables

USDA-ARS?s Scientific Manuscript database

The objective of this study was to evaluate mineral, vitamin C, phenolic and flavonoid concentrations and antioxidant activity levels in 15 leafy Amaranthus species. Across species, the concentration ranges of Ca, K, Mg, P and phenolics, and activity ranges of antioxidants in amaranth leaves were 1....

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

NASA Technical Reports Server (NTRS)

Carter, Gregory A.; Spiering, Bruce A.

2000-01-01

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

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

PubMed Central

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

2009-01-01

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

Occurrence of alk(en)ylresorcinols in the fruits of two mango (Mangifera indica L.) cultivars during on-tree maturation and postharvest storage.

PubMed

Kienzle, Stefanie; Carle, Reinhold; Sruamsiri, Pittaya; Tosta, Carola; Neidhart, Sybille

2014-01-08

Regarding their relevance for the fungal resistance of mangoes in long supply chains, the alk(en)ylresorcinols (AR) were quantitated in peel and mesocarp throughout storage (27 days, 14 °C, ethylene absorption). The 12 'Chok Anan' and 11 'Nam Dokmai #4' lots picked between 83 and 115 days after full bloom (DAFB) had different harvest maturity indices. The development of dry matter and fruit growth indicated physiological maturity ∼100 DAFB. During storage, all fruits ripened slowly, mostly until over-ripeness and visible decay. The total AR contents always ranged at 73 ± 4.5 and 6.4 ± 0.7 mg hg(-1) of 'Chok Anan' and 'Nam Dokmai #4' peel dry weight, respectively, but only at 6.7 ± 0.7 and 0.9 ± 0.1 mg hg(-1) for the corresponding mesocarp (P ≤ 0.05). These narrow concentration ranges were contradictory to the decreasing fungal resistance. Accordingly, the alk(en)ylresorcinols have not been a deciding factor for the fungal resistance.

Diagnosing oceanic nutrient deficiency

PubMed Central

2016-01-01

The supply of a range of nutrient elements to surface waters is an important driver of oceanic production and the subsequent linked cycling of the nutrients and carbon. Relative deficiencies of different nutrients with respect to biological requirements, within both surface and internal water masses, can be both a key indicator and driver of the potential for these nutrients to become limiting for the production of new organic material in the upper ocean. The availability of high-quality, full-depth and global-scale datasets on the concentrations of a wide range of both macro- and micro-nutrients produced through the international GEOTRACES programme provides the potential for estimation of multi-element deficiencies at unprecedented scales. Resultant coherent large-scale patterns in diagnosed deficiency can be linked to the interacting physical–chemical–biological processes which drive upper ocean nutrient biogeochemistry. Calculations of ranked deficiencies across multiple elements further highlight important remaining uncertainties in the stoichiometric plasticity of nutrient ratios within oceanic microbial systems and caveats with regards to linkages to upper ocean nutrient limitation. This article is part of the themed issue ‘Biological and climatic impacts of ocean trace element chemistry’. PMID:29035255

Vertical variation of mixing within porous sediment beds below turbulent flows

PubMed Central

Chandler, I. D.; Pearson, J. M.; van Egmond, R.

2016-01-01

Abstract River ecosystems are influenced by contaminants in the water column, in the pore water and adsorbed to sediment particles. When exchange across the sediment‐water interface (hyporheic exchange) is included in modeling, the mixing coefficient is often assumed to be constant with depth below the interface. Novel fiber‐optic fluorometers have been developed and combined with a modified EROSIMESS system to quantify the vertical variation in mixing coefficient with depth below the sediment‐water interface. The study considered a range of particle diameters and bed shear velocities, with the permeability Péclet number, PeK between 1000 and 77,000 and the shear Reynolds number, Re*, between 5 and 600. Different parameterization of both an interface exchange coefficient and a spatially variable in‐sediment mixing coefficient are explored. The variation of in‐sediment mixing is described by an exponential function applicable over the full range of parameter combinations tested. The empirical relationship enables estimates of the depth to which concentrations of pollutants will penetrate into the bed sediment, allowing the region where exchange will occur faster than molecular diffusion to be determined. PMID:27635104

High-speed microstrip multi-anode multichannel plate detector system

NASA Astrophysics Data System (ADS)

Riedo, Andreas; Tulej, Marek; Rohner, Urs; Wurz, Peter

2017-04-01

High-speed detector systems with high dynamic range and pulse width characteristics in the sub-nanosecond regime are mandatory for high resolution and highly sensitive time-of-flight mass spectrometers. Typically, for a reasonable detector area, an impedance-matched anode design is necessary to transmit the registered signal fast and distortion-free from the anode to the signal acquisition system. In this report, a high-speed microstrip multi-anode multichannel plate detector is presented and discussed. The anode consists of four separate active concentric anode segments allowing a simultaneous readout of signal with a dynamic range of about eight orders of magnitude. The impedance matched anode segments show pulse width of about 250 ps, measured at full width at half maximum, and rise time of ˜170 ps, measured with an oscilloscope with a sampling rate of 20 GS/s and 4 GHz analogue bandwidth. The usage of multichannel plates as signal amplifier allowed the design of a lightweight, low power consuming, and compact detector system, suitable, e.g., for the integration into space instrumentation or portable systems where size, weight, and power consumption are limited parameters.

Control of air emissions from POTWs using biofiltration

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

Webster, T.S.; Devinny, J.S.; Torres, E.M.

1995-12-31

The University of Southern California (USC), in collaboration with the County Sanitation Districts of Orange County (CSDOC), the South Coast Air Quality Management District (SCAQMD), Southern California Edison (SCE), the Water Environment Research Foundation (WERF), and Huntingdon Environmental Engineering, Inc. (HEEI), is conducting a research project to evaluate the application of biofiltration to remove volatile organic compounds (VOCs), odor-causing air pollutants, and toxics from a publicly owned treatment works (POTW) waste airstream. As part of this project, bench-scale and pilot-scale experiments are being conducted to test the effectiveness of biofiltration and determine the optimum parameters for applying biofiltration to POTWs.more » Results from the bench-scale experiments demonstrate that biofiltration is effective in reducing the concentration of hydrogen sulfide (H{sub 2}S) and total VOCs present in waste airstreams by over 99% and up to 90%, respectively. Average reduction of specific aromatic and carbonyl compounds ranged from 55% to 91%. Removal efficiencies for chlorinated hydrocarbons were variable, ranging from 6% to 88%. Overall, biofiltration appears to be a promising technology for full-scale implementation at POTWs for VOC and odor emission compliance.« less

Diagnosing oceanic nutrient deficiency

NASA Astrophysics Data System (ADS)

Moore, C. Mark

2016-11-01

The supply of a range of nutrient elements to surface waters is an important driver of oceanic production and the subsequent linked cycling of the nutrients and carbon. Relative deficiencies of different nutrients with respect to biological requirements, within both surface and internal water masses, can be both a key indicator and driver of the potential for these nutrients to become limiting for the production of new organic material in the upper ocean. The availability of high-quality, full-depth and global-scale datasets on the concentrations of a wide range of both macro- and micro-nutrients produced through the international GEOTRACES programme provides the potential for estimation of multi-element deficiencies at unprecedented scales. Resultant coherent large-scale patterns in diagnosed deficiency can be linked to the interacting physical-chemical-biological processes which drive upper ocean nutrient biogeochemistry. Calculations of ranked deficiencies across multiple elements further highlight important remaining uncertainties in the stoichiometric plasticity of nutrient ratios within oceanic microbial systems and caveats with regards to linkages to upper ocean nutrient limitation. This article is part of the themed issue 'Biological and climatic impacts of ocean trace element chemistry'.

Flow resistance and suspended load in sand-bed rivers: Simplified stratification model

USGS Publications Warehouse

Wright, S.; Parker, G.

2004-01-01

New methods are presented for the prediction of the flow depth, grain-size specific near-bed concentration, and bed-material suspended sediment transport rate in sand-bed rivers. The salient improvements delineated here all relate to the need to modify existing formulations in order to encompass the full range of sand-bed rivers, and in particular large, low-slope sand-bed rivers. They can be summarized as follows: (1) the inclusion of density stratification effects in a simplified manner, which have been shown in the companion paper to be particularly relevant for large, low-slope, sand-bed rivers; (2) a new predictor for near-bed entrainment rate into suspension which extends a previous relation to the range of large, low-slope sand-bed rivers; and (3) a new predictor for form drag which again extends a previous relation to include large, low-slope sand-bed rivers. Finally, every attempt has been made to cast the relations in the simplest form possible, including the development of software, so that practicing engineers may easily use the methods. ?? ASCE.

Quantitative tomographic imaging of intermolecular FRET in small animals

PubMed Central

Venugopal, Vivek; Chen, Jin; Barroso, Margarida; Intes, Xavier

2012-01-01

Forster resonance energy transfer (FRET) is a nonradiative transfer of energy between two fluorescent molecules (a donor and an acceptor) in nanometer range proximity. FRET imaging methods have been applied to proteomic studies and drug discovery applications based on intermolecular FRET efficiency measurements and stoichiometric measurements of FRET interaction as quantitative parameters of interest. Importantly, FRET provides information about biomolecular interactions at a molecular level, well beyond the diffraction limits of standard microscopy techniques. The application of FRET to small animal imaging will allow biomedical researchers to investigate physiological processes occurring at nanometer range in vivo as well as in situ. In this work a new method for the quantitative reconstruction of FRET measurements in small animals, incorporating a full-field tomographic acquisition system with a Monte Carlo based hierarchical reconstruction scheme, is described and validated in murine models. Our main objective is to estimate the relative concentration of two forms of donor species, i.e., a donor molecule involved in FRETing to an acceptor close by and a nonFRETing donor molecule. PMID:23243567

The thermodynamic parameters of solution of L-phenylalanine in water

NASA Astrophysics Data System (ADS)

Kustov, A. V.; Korolev, V. P.

2007-02-01

The heat effects of solution of L-phenylalanine in water were measured over wide concentration and temperature ranges. The enthalpies of solution of L-phenylalanine were found to be independent of the content of the amino acid in solution over the concentration range studied. The standard enthalpies, heat capacities, and entropies of solution of the amino acid and the solubility of L-phenylalanine over the temperature range studied were calculated.

40 CFR 53.62 - Test procedure: Full wind tunnel test.

Code of Federal Regulations, 2010 CFR

2010-07-01

... distributions to provide six estimates of measured mass concentration. Critical parameters for these idealized... (expressed as a percentage) of the mass concentration of particles of a specific size reaching the sampler filter or filters to the mass concentration of particles of the same size approaching the sampler. (c...

Effects of depleted uranium on survival, growth, and metamorphosis in the african clawed frog (Xenopus laevis)

USGS Publications Warehouse

Mitchell, S.E.; Caldwell, C.A.; Gonzales, G.; Gould, W.R.; Arimoto, R.

2005-01-01

Embryos (stage 8-47, Nieuwkoop and Faber) of the African clawed frog (Xenopus laevis) were subjected to water-borne depleted uranium (DU) concentrations that ranged from 4.8 to 77.7 mg/Lusing an acute 96-h frog embryo teratogenesis assay-Xenopus (FETAX). In a chronic 64-d assay, X. laevis (from embryo through metamorphosis; stages 8-66) were subjected to concentrations of DU that ranged from 6.2 to 54.3 mg/L Our results indicate DU is a non teratogenic metal. No effects on mortality, malformations, or growth were observed in the 96-h FETAX with concentrations of DU that ranged from 4.8 to 77.7 mg/L From stage 8 to stage 47, X. laevis tadpoles do not actively feed and the gills are not well developed. Thus, uptake of DU was reduced despite exposure to elevated concentrations. The 64-d assay resulted in no concentration response for either mortality or malformations; however, a delay in metamorphosis was observed in tadpoles subjected to elevated DU concentrations (from 13.1 to 54.3 mg/L) compared to tadpoles in both the well-water control and reference. The delay in metamorphosis was likely due to increasing body burden of DU that ranged from 0.98 to 2.82 mg/kg. Copyright?? Taylor & Francis Inc.

Trophic transfer of metals in a seagrass food web: Bioaccumulation of essential and non-essential metals.

PubMed

Schneider, Larissa; Maher, William A; Potts, Jaimie; Taylor, Anne M; Batley, Graeme E; Krikowa, Frank; Adamack, Aaron; Chariton, Anthony A; Gruber, Bernd

2018-06-01

Metal concentrations are reported for a seagrass ecosystem receiving industrial inputs. δ 13 C and δ 15 N isotope ratios were used to establish trophic links. Copper concentrations (dry mass) ranged from <0.01 μg/g in fish species to 570 μg/g (μ = 49 ± SD = 90 μg/g) in the oyster Saccostrea glomerata. Zinc concentrations ranged from 0.6 μg/g in the seagrass Zostera capricorni to 10,800 μg/g in the mud oyster Ostrea angasi (μ = 434 ± 1390 μg/g). Cadmium concentrations ranged from <0.01 μg/g in fish species to 268 μg/g in Ostrea angasi (μ = 6 ± 25 μg/g). Lead concentrations ranged from <0.01 μg/g for most fish species to 20 μg/g in polychaetes (μ = 2 ± 3 μg/g). Biomagnification of metals did not occur. Organisms that fed on particulate organic matter and benthic microalgae had higher metal concentrations than those that fed on detritus. Species physiology also played an important role in the bioaccumulation of metals. Copyright © 2018 Elsevier Ltd. All rights reserved.

Vitamin blood concentration and vitamin supplementation in bottlenose dolphins (Tursiops truncatus) in European facilities.

PubMed

Gimmel, Angela Emilia Ricarda; Baumgartner, Katrin; Liesegang, Annette

2016-09-05

As fish eaters bottlenose dolphins (Tursiops truncatus) in human care need to receive daily vitamin supplementation, because whole thawed fish lacks certain vitamins. However, the exact concentration of supplementation has not been established and is a matter of discussion. To ensure adequate vitamin supplementation in pets, vitamin blood concentrations are measured. This is not a common practice in dolphins. The objective of the present study was to collect information about vitamin supplementation in bottlenose dolphins and on vitamin blood concentrations of healthy animals in European facilities. In addition, these results were compared with blood levels of wild animals. Conclusions on how to provide bottlenose dolphins in human care with an effective vitamin supplementation will then be drawn. Initially, fish-handling techniques and vitamin supplementation were evaluated by questionnaire, which was sent to 25 European facilities that house bottlenose dolphins. Secondly, blood samples from 57 dolphins living in 10 facilities were taken and sent by mail to a reference laboratory. They were analysed for retinol, thiamine pyrophosphate, cobalamin, calcidiol and tocopherol. The blood concentrations were then correlated with vitamin supplementation, fish handling techniques and pre-existing blood concentrations of free-ranging dolphins. Finally, the data was subjected to a standard analysis of variance techniques (ANOVA) and a linear model analysis. Fish was mainly thawed in a refrigerator. Further, the 95 % confidence interval for retinol blood concentrations was 0.048 to 0.059 mg/l and for tocopherol 17.95 to 20.76 mg/l. These concentrations were 27 and 53 %, respectively, higher than those found in free-ranging animals. In contrast, calcidiol concentrations (143.9-174.7 ng/ml) of the dolphins in human care were lower than in blood found for free-ranging animals. Regarding thiamine pyrophosphate and cobalamin, concentrations ranged between 0.42 and 0.55 mg/l and 175.55 and 275.22 pg/ml respectively. No reference concentrations for free-ranging Tursiops truncatus were found. These findings suggest an over-supplementation of retinol (vitamin A) and tocopherol (vitamin E) in bottlenose dolphins (Tursiops truncatus) housed in human care. Therefore, vitamin A supplementation should not exceed 50,000 IU per animal per day and vitamin E supplementation should be around 100 IU per kg fed fish per day.

Exposure to bioaerosols in the selected agricultural facilities of the Ukraine and Poland - a review.

PubMed

Tsapko, Valentin G; Chudnovets, Alla J; Sterenbogen, Marina J; Papach, Vladimir V; Dutkiewicz, Jacek; Skórska, Czesława; Krysińska-Traczyk, Ewa; Golec, Marcin

2011-01-01

The aim of this work was to review the studies on bioaerosols which were carried out in the years 1972-2009 in following branches of agricultural industry in the Ukraine and Poland: animal farms for cows and pigs, animal feed facilities, production of biofuel from rape, herb farms and herb processing facilities. In all facilities were determined: concentration of dust and microorganisms in the air and species composition of microflora. Moreover, in Polish animal farms, herb farms and herb processing facilities, as well as in the Ukrainian animal feed facilities, was determined the concentration of bacterial endotoxin in the air. Dust concentrations in animal farms located in the Ukraine and Poland ranged from 6-200 mg/m(3) and from 0.25-14.05 mg/m(3), respectively, while in animal feed facilities they ranged from 35-306 mg/m(3) and from 3.8-405 mg/m(3), respectively. Dust concentrations in the facilities producing biofuel from rape in the Ukraine were in the range 3.6-28 mg/m(3), whereas on herb farms and in herb processing facilities in Poland they were in the range 0.8- 1,319.6 mg/m(3), and 2.2-946 mg/m(3), respectively. The determined values exceeded in most cases the maximal acceptable concentration (MAC) which in the Ukraine and Poland is equal to 4 mg/m(3). The concentrations of microorganisms on animal farms located in the Ukraine and Poland ranged from 5.5 x 10(4)- 1.9 x 10(7) cfu/m(3) and from 4.7 x 10(4)-1.5 x 10(6) cfu/m(3), respectively, while in animal feed facilities they ranged from 2.7 x 10(4)-2.6 x 10(9) cfu/m(3) and from 1.7 x 10(3)-2.0 x 10(6) cfu/m(3), respectively. Concentrations of microorganisms in the facilities producing biofuel from rape in the Ukraine were in the range 1.5 x 10(3)-5.7 x 10(6) cfu/m(3), whereas on herb farms and in herb processing facilities in Poland they were in the ranges of 8.8 x 10(2)-8.0 x 10(6) cfu/m(3), and 9.7 x 10(3)-6.3 x 10(5) cfu/m(3), respectively. The determined values exceeded in most cases the maximal acceptable concentration (MAC) which in the Ukraine is equal to 5.0 x 10(4) cfu/m(3). The concentrations of endotoxin in Polish animal houses were in the range 0.00125-75.0 ug/m(3), whereas on herb farms and herb processing facilities they were in the ranges of 0.0045- 2,448.8 ug/m(3) and 0.2-681.0 ug/m(3), respectively, and in the Ukrainian animal feed facilities were within the range 0.008-240.0 ug/m(3). They exceeded in most cases the level of 0.2 ug/m(3) proposed as a threshold. In the air microflora of examined facilities prevailed Gram-positive bacteria (corynebacteria, cocci, spore-forming bacilli, actinomycetes) of which some (Arthrobacter spp., thermophilic actinomycetes) could be a cause of allergic alveolitis (hypersensitivity pneumonitis). Among Gram-negative bacteria isolated from the air of agricultural settings dominated the epiphytic species Pantoea agglomerans, possessing potent allergenic and endotoxic properties. Fungi were abundant in the air of the Ukrainian agricultural settings and comprised species able to produce harmful mycotoxins. In conclusion, the airborne biological factors in stated concentrations may exert harmful effects on the state of the health of exposed workers. Formation of the bioaerosol depends on the specificity of the setting, kind of technological operations, degree of mechanization, properties of processed materials, temperature and humidity, and concentration of dust in the air.

Application of auxin-inducible degron technology to mouse oocyte activation with PLCζ.

PubMed

Miura, Kento; Matoba, Shogo; Ogonuki, Narumi; Namiki, Takafumi; Ito, Junya; Kashiwazaki, Naomi; Ogura, Atsuo

2018-05-05

In mammals, spermatozoa activate oocytes by triggering a series of intracellular Ca 2+ oscillations with phospholipase C zeta (PLCζ), a sperm-borne oocyte-activating factor. Because the introduction of PLCζ alone can induce oocyte activation, it might be a promising reagent for assisted reproductive technologies. To test this possibility, we injected human PLCζ (hPLCζ) mRNA into mouse oocytes at different concentrations. We observed the oocyte activation and subsequent embryonic development. Efficient oocyte activation and embryonic development to the blastocyst stage was achieved only with a limited range of mRNA concentrations (0.1 ng/μl). Higher concentrations of mRNA caused developmental arrest of most embryos, suggesting that excessive PLCζ protein might be harmful at this stage. In a second series of experiments, we aimed to regulate the PLCζ protein concentration in oocytes by applying auxin-inducible degron (AID) technology that allows rapid degradation of the target protein tagged with AID induced by auxin. Injection of the hPLCζ protein tagged with AID and enhanced green fluorescent protein (hPLCζ-AID-EGFP) demonstrated that high EGFP expression levels at the late 1-cell stage were efficiently reduced by auxin treatment, suggesting efficient hPLCζ degradation by this system. Furthermore, the defective development observed with higher concentrations of hPLCζ-AID-EGFP mRNA was rescued following auxin treatment. Full-term offspring were obtained by round spermatid injection with optimized hPLCζ-AID activation. Our results indicate that this AID technology can be applied to regulate the protein levels in mouse oocytes and that our optimized PLCζ system could be used for assisted fertilization in mammals.

White zein colloidal particles: synthesis and characterization of their optical properties on the single particle level and in concentrated suspensions.

PubMed

de Boer, F Y; Kok, R N U; Imhof, A; Velikov, K P

2018-04-18

Growing interest in using natural, biodegradable ingredients for food products leads to an increase in research for alternative sources of functional ingredients. One alternative is zein, a water-insoluble protein from corn. Here, a method to investigate the optical properties of white zein colloidal particles is presented in both diluted and concentrated suspensions. The particles are synthesized, after purification of zein, by anti-solvent precipitation. Mean particle diameters ranged from 35 to 135 nm based on dynamic light scattering. The value of these particles as white colorant is examined by measuring their optical properties. Dilute suspensions are prepared to measure the extinction cross section of individual particles and this was combined with Mie theory to determine a refractive index (RI) of 1.49 ± 0.01 for zein particles dispersed in water. This value is used to further model the optical properties of concentrated suspensions. To obtain full opacity of the suspension, comparable to 0.1-0.2 wt% suspensions of TiO2, concentrations of 2 to 3.3 wt% of zein particles are sufficient. The optimal size for maximal scattering efficiency is explored by modeling dilute and concentrated samples with RI's matching those of zein and TiO2 particles in water. The transport mean free path of light was determined experimentally and theoretically and the agreement between the transport mean free path calculated from the model and the measured value is better than 30%. Such particles have the potential to be an all-natural edible alternative for TiO2 as white colorant in wet food products.

Mechanosensitive cation channels in human leukaemia cells: calcium permeation and blocking effect

PubMed Central

Staruschenko, Alexandr V; Vedernikova, Elena A

2002-01-01

Cell-attached and inside-out patch-clamp methods were employed to identify and characterize mechanosensitive (MS) ionic channels in the plasma membrane of human myeloid leukaemia K562 cells. A reversible activation of gadolinium-blockable mechanogated currents in response to negative pressure application was found in 58 % of stable patches (n = 317). I-V relationships measured with a sodium-containing pipette solution showed slight inward rectification. Data analysis revealed the presence of two different populations of channels that were distinguishable by their conductance properties (17.2 ± 0.3 pS and 24.5 ± 0.5 pS), but were indistinguishable with regard to their selective and pharmacological properties. Ion-substitution experiments indicated that MS channels in leukaemia cells were permeable to cations but not to anions and do not discriminate between Na+ and K+. The channels were fully impermeable to large organic cations such as Tris+ and N-methyl-d-glucamine ions (NMDG+). Ca2+ permeation and blockade of MS channels were examined using pipettes containing different concentrations of Ca2+. In the presence of 2 mm CaCl2, when other cations were impermeant, both outward and inward single-channel currents were observed; the I-V relationship showed a unitary conductance of 7.7 ± 1.0 pS. The relative permeability value, PCa/PK, was equal to 0.75, as estimated at physiological Ca2+ concentrations. Partial or full inhibition of inward Ca2+ currents through MS channels was observed at higher concentrations of external Ca2+ (10 or 20 mm). No MS channels were activated when using a pipette containing 90 mm CaCl2. Monovalent mechanogated currents were not significantly affected by extracellular Ca2+ at concentrations within the physiological range (0-2 mm), and at some higher Ca2+ concentrations. PMID:12015421