Low concentrations of bilirubin inhibit activation of hepatic stellate cells in vitro.

PubMed

Tang, Yinhe; Zhang, Qiyu; Zhu, Yefan; Chen, Gang; Yu, Fuxiang

2017-04-01

Hepatic stellate cell (HSC) activation serves a key role in liver fibrosis, and is associated with chronic liver diseases. Bilirubin, a product of heme degradation, has been demonstrated to have antioxidant properties. The present study investigated the effects of physiological concentrations of bilirubin on rat HSC activation. Rat HSCs were isolated and cultured for several generations to induce activation. The activated HSCs were subsequently treated with 0, 1, 10 or 20 mg/l bilirubin and assayed for parameters of cell activation. As the bilirubin concentration increased, HSCs demonstrated reduced production of reactive oxygen species, reduced protein expression levels of α‑smooth muscle actin, a decreased mRNA expression ratio of tissue inhibitor of matrix metalloproteinase‑1/matrix metalloproteinase‑2, decreased proliferation and increased apoptosis. In conclusion, elevated bilirubin levels, within its physiological concentration range, appeared to inhibit HSC activation. These findings suggested a potential role for bilirubin in the treatment of fibrosis that requires further investigation.

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.

Metabolic Potential and Activity in Fluids of the Coast Range Ophiolite Microbial Observatory, California, USA

NASA Technical Reports Server (NTRS)

Hoehler, T.; Som, S.; Schrenk, M.; McCollom, T.; Cardace, D.

2016-01-01

Metabolic potential and activity associated with hydrogen and carbon monoxide were characterized in fluids sampled from the the Coast Range Ophiolite Microbial Observatory (CROMO). CROMO consists of two clusters of science-dedicated wells drilled to varying depths up to 35m in the actively serpentinizing, Jurassic-age Coast Range Ophiolite of Northern California, along with a suite of pre-existing monitoring wells at the same site. Consistent with the fluid chemistry observed in other serpentinizing systems, CROMO fluids are highly alkaline, with pH up to 12.5, high in methane, with concentrations up 1600 micromolar, and low in dissolved inorganic carbon (DIC), with concentrations of 10's to 100's of micromolar. CROMO is conspicuous for fluid H2 concentrations that are consistently sub-micromolar, orders of magnitude lower than is typical of other systems. However, higher H2 concentrations (10's -100's of micromolar) at an earlier stage of fluid chemical evolution are predicted by, or consistent with: thermodynamic models for fluid chemistry based on parent rock composition equivalent to local peridotite and with water:rock ratio constrained by observed pH; the presence of magnetite at several wt% in CROMO drill cores; and concentrations of formate and carbon monoxide that would require elevated H2 if formed in equilibrium with H2 and DIC. Calculated Gibbs energy changes for reaction of H2 and CO in each of several metabolisms, across the range of fluid composition encompassed by the CROMO wells, range from bioenergetically feasible (capable of driving ATP synthesis) to thermodynamically unfavorable. Active consumption relative to killed controls was observed for both CO and H2 during incubation of fluids from the pre-existing monitoring wells; in incubations of freshly cored solids, consumption was only observed in one sample set (corresponding to the lowest pH) out of three. The specific metabolisms by which H2 and CO are consumed remain to be determined.

Multi-wavelength dye concentration determination for enzymatic assays: evaluation of chromogenic para-nitrophenol over a wide pH range.

PubMed

Max, Jean-Joseph; Meddeb-Mouelhi, Fatma; Beauregard, Marc; Chapados, Camille

2012-12-01

Enzymatic assays need robust, rapid colorimetric methods that can follow ongoing reactions. For this, we developed a highly accurate, multi-wavelength detection method that could be used for several systems. Here, it was applied to the detection of para-nitrophenol (pNP) in basic and acidic solutions. First, we confirmed by factor analysis that pNP has two forms, with unique spectral characteristics in the 240 to 600 nm range: Phenol in acidic conditions absorbs in the lower range, whereas phenolate in basic conditions absorbs in the higher range. Thereafter, the method was used for the determination of species concentration. For this, the intensity measurements were made at only two wavelengths with a microtiter plate reader. This yielded total dye concentration, species relative abundance, and solution pH value. The method was applied to an enzymatic assay. For this, a chromogenic substrate that generates pNP after hydrolysis catalyzed by a lipase from the fungus Yarrowia lipolytica was used. Over the pH range of 3-11, accurate amounts of acidic and basic pNP were determined at 340 and 405 nm, respectively. This method surpasses the commonly used single-wavelength assay at 405 nm, which does not detect pNP acidic species, leading to activity underestimations. Moreover, alleviation of this pH-related problem by neutralization is not necessary. On the whole, the method developed is readily applicable to rapid high-throughput of enzymatic activity measurements over a wide pH range.

Concentrated dispersions of equilibrium protein nanoclusters that reversibly dissociate into active monomers

NASA Astrophysics Data System (ADS)

Truskett, Thomas M.; Johnston, Keith; Maynard, Jennifer; Borwankar, Ameya; Miller, Maria; Wilson, Brian; Dinin, Aileen; Khan, Tarik; Kaczorowski, Kevin

2012-02-01

Stabilizing concentrated protein solutions is of wide interest in drug delivery. However, a major challenge is how to reliably formulate concentrated, low viscosity (i.e., syringeable) solutions of biologically active proteins. Unfortunately, proteins typically undergo irreversible aggregation at intermediate concentrations of 100-200 mg/ml. In this talk, I describe how they can effectively avoid these intermediate concentrations by reversibly assembling into nanoclusters. Nanocluster assembly is achieved by balancing short-ranged, cosolute-induced attractions with weak, longer-ranger electrostatic repulsions near the isoelectric point. Theory predicts that native proteins are stabilized by a self-crowding mechanism within the concentrated environment of the nanoclusters, while weak cluster-cluster interactions can result in colloidally-stable dispersions with moderate viscosities. I present experimental results where this strategy is used to create concentrated antibody dispersions (up to 260 mg/ml) comprising nanoclusters of proteins [monoclonal antibody 1B7, polyclonal sheep Immunoglobin G and bovine serum albumin], which upon dilution in vitro or administration in vivo, are conformationally stable and retain activity.

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.

Range of therapeutic prothipendyl and prothipendyl sulfoxide concentrations in clinical blood samples.

PubMed

Krämer, Michael; Heese, Peter; Banger, Markus; Madea, Burkhard; Hess, Cornelius

2018-06-01

Due to a lack of reference blood concentrations in the literature, the forensic evaluation of prothipendyl findings in blood samples is difficult. Interpretations with regard to the assessment of blood concentrations as well as an estimation of the ingested prothipendyl amounts were often vague. To describe a concentration range in clinical samples, prothipendyl and prothipendyl sulfoxide concentrations were determined in serum samples of 50 psychiatric patients receiving 40 mg, 80 mg, or 160 mg doses of prothipendyl. The analyses of prothipendyl and prothipendyl sulfoxide were carried out using validated methods of high performance liquid chromatography coupled to triple quadrupole mass spectrometry (LC-QQQ-MS), respectively. 40 mg doses caused average prothipendyl serum concentrations of 18.0 ng/mL (1 hour after intake) and 7.9 ng/mL (10.5 hours after intake), while 80 mg doses caused averages of 42.6 ng/mL and 15.2 ng/mL at the mentioned times of sampling. Irrespective of the given dose, prothipendyl concentrations below 30 ng/mL were observed in 80% of the patient samples taken 1 hour after ingestion as well as in 90% of the samples collected 10.5 hours after administration. Serum concentrations of the Phase I metabolite prothipendyl sulfoxide averaged 4.3 ng/mL (1 hour after intake) and 3.6 ng/mL (10.5 hours after intake). Possible drug-drug interactions regarding absorption and metabolism of prothipendyl are discussed. Results of the herein presented study are useful for the interpretation of analytical prothipendyl findings in forensic toxicology. The utility of the described concentration range is demonstrated by discussing two death cases involving prothipendyl findings. Copyright © 2017 John Wiley & Sons, Ltd.

Solution Behavior and Activity of a Halophilic Esterase under High Salt Concentration

PubMed Central

Rao, Lang; Zhao, Xiubo; Pan, Fang; Li, Yin; Xue, Yanfen; Ma, Yanhe; Lu, Jian R.

2009-01-01

Background Halophiles are extremophiles that thrive in environments with very high concentrations of salt. Although the salt reliance and physiology of these extremophiles have been widely investigated, the molecular working mechanisms of their enzymes under salty conditions have been little explored. Methodology/Principal Findings A halophilic esterolytic enzyme LipC derived from archeaon Haloarcula marismortui was overexpressed from Escherichia coli BL21. The purified enzyme showed a range of hydrolytic activity towards the substrates of p-nitrophenyl esters with different alkyl chains (n = 2−16), with the highest activity being observed for p-nitrophenyl acetate, consistent with the basic character of an esterase. The optimal esterase activities were found to be at pH 9.5 and [NaCl] = 3.4 M or [KCl] = 3.0 M and at around 45°C. Interestingly, the hydrolysis activity showed a clear reversibility against changes in salt concentration. At the ambient temperature of 22°C, enzyme systems working under the optimal salt concentrations were very stable against time. Increase in temperature increased the activity but reduced its stability. Circular dichroism (CD), dynamic light scattering (DLS) and small angle neutron scattering (SANS) were deployed to determine the physical states of LipC in solution. As the salt concentration increased, DLS revealed substantial increase in aggregate sizes, but CD measurements revealed the maximal retention of the α-helical structure at the salt concentration matching the optimal activity. These observations were supported by SANS analysis that revealed the highest proportion of unimers and dimers around the optimal salt concentration, although the coexistent larger aggregates showed a trend of increasing size with salt concentration, consistent with the DLS data. Conclusions/Significance The solution α-helical structure and activity relation also matched the highest proportion of enzyme unimers and dimers. Given that

Effect of HCl Loading and Ethanol Concentration over HCl-Activated Clay Catalysts for Ethanol Dehydration to Ethylene.

PubMed

Krutpijit, Chadaporn; Jongsomjit, Bunjerd

2017-01-01

Montmorillonite clay (MMT) is one of materials that can be "green material" due to its environmental safety. In this work, acid-activated MMT catalysts were prepared for the dehydration reaction of ethanol. To be the green process, the reaction with bioethanol was also studied. Ethanol concentrations in feed were varied in the range of 10-99.95 wt%. Moreover, the concentrations of hydrochloric acid activated MMT were investigated in range of 0.05-4 M. From the experiment, it reveals that different acid concentrations to activate MMT affect the catalytic activity of catalysts. The 0.3 M of HCl activated MMT exhibits the highest activity (under the best condition of 30 ml HCl aging for 1 h) with the Si/Al ratio of 7.4. It can reach the ethanol conversion and ethylene selectivity up to 95% and 98% at reaction temperature of 400°C, respectively. For the several ethanol feed concentrations, it does not remarkably affect in ethanol conversion. However, it has some different effect on ethylene selectivity between lower and higher reaction temperatures. It was found that at lower temperature reaction, ethylene selectivity is high due to the behavior of water in feed. In addition, the 0.3 M-MMT can be carried out under the hydrothermal effect.

Radon activity concentrations and effective doses in ancient Egyptian tombs of the Valley of the Kings.

PubMed

Hafez, A F; Hussein, A S

2001-09-01

Radon concentrations and equilibrium factors were measured in three pharaonic tombs during the year 1998. The tombs, which are open to the public are located in a limestone wadi on the West Bank of the River Nile at Luxor, 650 km south of Cairo. The radon activity concentration and equilibrium factor were measured monthly by two-integral nuclear track detectors (bare and diffusion detectors). Seasonal variation of radon concentrations, with summer maximum and winter minimum were observed in all tombs investigated. The yearly mean radon activity concentrations insidc the tombs ranged from 540 to 3115 Bq m(-3). The mean equilibrium factor over a year was found to be 0.25 and 0.32 inside and at the entrance, respectively. Estimated annual effective doses to tour guides ranged from 0.33 to 1.90 mSv, visitors receive doses from 0.65 to 3.80 microSv per visit. The effective dose to tomb workers did not exceed the 20 mSv yr(-1) limit.

Plasma lactate concentrations in free-ranging moose (Alces alces) immobilized with etorphine.

PubMed

Haga, Henning A; Wenger, Sandra; Hvarnes, Silje; Os, Oystein; Rolandsen, Christer M; Solberg, Erling J

2009-11-01

To investigate plasma lactate concentrations of etorphine-immobilized moose in relation to environmental, temporal and physiological parameters. Prospective clinical study. Fourteen female and five male moose (Alces alces), estimated age range 1-7 years. The moose were darted from a helicopter with 7.5 mg etorphine per animal using projectile syringes and a dart gun. Once immobilized, the moose were approached, a venous blood sample was obtained and vital signs including pulse oximetry were recorded. Diprenorphine was administered to reverse the effects of etorphine. Timing of events, ambient temperature and snow depth were recorded. Blood samples were cooled and centrifuged before plasma was harvested and frozen. The plasma was thawed later and lactate analysed. Data were analysed using descriptive statistics and regression analysis. All animals recovered uneventfully and were alive 12 weeks after immobilization. Mean +/- SD plasma lactate was found to be 9.2 +/- 2.1 mmol L(-1). Plasma lactate concentrations were related positively to snow depth and negatively to time from induction of immobilization to blood sampling. The model that best described the variability in plasma lactate concentrations used induction time (time from firing the dart to the moose being immobilized). The second best model included induction time and snow depth. Plasma lactate concentrations in these etorphine-immobilized moose were in the range reported for other immobilized wild ruminants. Decreasing induction time, which may be related to a more profound etorphine effect, and increasing snow depth possibly may increase plasma lactate concentrations in etorphine-immobilized moose.

Detection of saliva-range glucose concentrations using organic thin-film transistors

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

Elkington, D.; Belcher, W. J.; Dastoor, P. C.

We describe the development of a glucose sensor through direct incorporation of an enzyme (glucose oxidase) into the gate of an organic thin film transistor (OTFT). We show that glucose diffusion is the key determinant of the device response time and present a mechanism of glucose sensing in these devices that involves protonic doping of the transistor channel via enzymatic oxidation of glucose. The integrated OTFT sensor is sensitive across 4 decades of glucose concentration; a range that encompasses both the blood and salivary glucose concentration levels. As such, this work acts as a proof-of-concept for low-cost printed biosensors formore » salivary glucose.« less

Photoactive bile salts with critical micellar concentration in the micromolar range.

PubMed

Gomez-Mendoza, Miguel; Marin, M Luisa; Miranda, Miguel A

2016-05-14

The aggregation behavior of bile salts is strongly dependent on the number of hydroxyl groups. Thus, cholic acid (CA), with three hydroxyls, starts forming aggregates at 15 mM, while deoxycholic, chenodeoxycholic or ursodeoxycholic acids, with two hydroxyls, start aggregating at 5-10 mM; for lithocholic acid, with only one hydroxyl group, aggregation is observed at lower concentration (2-3 mM). Here, the singular self-assembling properties of dansyl and naproxen derivatives of CA (3β-Dns-CA and 3β-NPX-CA, respectively) have been demonstrated on the basis of their photoactive properties. Thus, the emission spectra of 3β-Dns-CA registered at increasing concentrations (25-140 μM) showed a remarkable non-linear enhancement in the emission intensity accompanied by a hypsochromic shift of the maximum and up to a three-fold increase in the singlet lifetime. The inflection point at around 50-70 μM pointed to the formation of unprecedented assemblies at such low concentrations. In the case of 3β-NPX-CA, when the NPX relative triplet lifetime was plotted against concentration, a marked increase (up to two-fold) was observed at 40-70 μM, indicating the formation of new 3β-NPX-CA assemblies at ca. 50 μM. Additional evidence supporting the formation of new 3β-Dns-CA or 3β-NPX-CA assemblies at 40-70 μM was obtained from singlet excited state quenching experiments using iodide. Moreover, to address the potential formation of hybrid assemblies, 1 : 1 mixtures of 3β-Dns-CA and 3β-NPX-CA (2-60 μM, total concentration) were subjected to steady-state fluorescence experiments, and their behavior was compared to that of the pure photoactive derivatives. A lower increase in the emission was observed for 3β-NPX-CA in the mixture, while a huge increase was experienced by 3β-Dns-CA in the same concentration range (up to 60 μM total). A partial intermolecular energy transfer from NPX to Dns, consistent with their reported singlet energies, was revealed, pointing to the

Fecal 20-oxo-pregnane concentrations in free-ranging African elephants (Loxodonta africana) treated with porcine zona pellucida vaccine.

PubMed

Ahlers, M J; Ganswindt, A; Münscher, S; Bertschinger, H J

2012-07-01

Because of overpopulation of African elephants in South Africa and the consequent threat to biodiversity, the need for a method of population control has become evident. In this regard, the potential use of the porcine zona pellucida (pZP) vaccine as an effective means for population control is explored. While potential effects of pZP treatment on social behavior of African elephants have been investigated, no examination of the influence of pZP vaccination on the endocrine correlates in treated females has been undertaken. In this study, ovarian activity of free-ranging, pZP-treated African elephant females was monitored noninvasively for 1 yr at Thornybush Private Nature Reserve, South Africa, by measuring fecal 5α-pregnan-3β-ol-20-on concentrations via enzyme immunoassay. A total of 719 fecal samples from 19 individuals were collected over the study period, averaging 38 samples collected per individual (minimum, maximum: 16, 52). Simultaneously, behavioral observations were made to record the occurrence of estrous behavior for comparison. Each elephant under study showed 5α-pregnan-3β-ol-20-on concentrations rising above baseline at some period during the study indicating luteal activity. Average 5α-pregnan-3β-ol-20-on concentrations were 1.61 ± 0.46 μg/g (mean ± SD). Within sampled females, 42.9% exhibited estrous cycles within the range reported for captive African elephants, 14.3% had irregular cycles, and 42.9% did not appear to be cycling. Average estrous cycle duration was 14.72 ± 0.85 wk. Estrous behavior coincided with the onset of the luteal phase and a subsequent rise in 5α-pregnan-3β-ol-20-on concentrations. Average 5α-pregnan-3β-ol-20-on levels positively correlated with rainfall. No association between average individual 5α-pregnan-3β-ol-20-on concentrations or cyclicity status with age or parity were detected. Earlier determination of efficacy was established via fecal hormone analysis with no pregnancies determined 22 mo post

Age and socially related changes in fecal androgen metabolite concentrations in free-ranging male giraffes.

PubMed

Wolf, T E; Schaebs, F S; Bennett, N C; Burroughs, R; Ganswindt, A

2018-01-01

In many mammal species, androgen levels in males are elevated during periods of mating activity, often to facilitate aggressive behavior between males over access to fertile females. However, this pattern might be less obvious in species with a rather low male-male aggression rate, or in those that are not strictly seasonal breeders. A complex social structure, as well as additional social and environmental factors, might add more to the complexity. Here, we applied a non-invasive method to monitor fecal androgen metabolite (fAM) levels in free-ranging giraffe bulls over a period of months to examine longitudinal patterns of androgen metabolite concentrations in relation to observed male sexual behavior in different age classes. Giraffes are non-seasonal breeders, living in a fission-fusion social system and males show a roaming strategy to search for fertile females. Our results show that season has an impact on fAM levels in free-ranging giraffes, with respective steroid concentrations being higher in summer. In the presence of females, fAM levels of bulls are significantly higher compared to when found in all-male groups, with old adult bulls showing the highest fAM levels. In contrast, young adult bulls have overall slightly higher fAM levels compared to old adult bulls when residing in all male groups. Sexual behavior increases fAM levels only in old adult bulls. Copyright © 2017 Elsevier Inc. All rights reserved.

Activated Prothrombin Complex Concentrate Versus 4-Factor Prothrombin Complex Concentrate for Vitamin K-Antagonist Reversal.

PubMed

Rowe, A Shaun; Dietrich, Scott K; Phillips, John W; Foster, Kaci E; Canter, Joshua R

2018-06-01

To compare the international normalized ratio normalization efficacy of activated prothrombin complex concentrates and 4-factor prothrombin complex concentrates and to evaluate the thrombotic complications in patients treated with these products for warfarin-associated hemorrhage. Retrospective, Multicenter Cohort. Large, Community, Teaching Hospital. Patients greater than 18 years old and received either activated prothrombin complex concentrate or 4-factor prothrombin complex concentrate for the treatment of warfarin-associated hemorrhage. We excluded those patients who received either agent for an indication other than warfarin-associated hemorrhage, pregnant, had a baseline international normalized ratio of less than 2, received a massive transfusion as defined by hospital protocol, received plasma for treatment of warfarin-associated hemorrhage, or were treated for an acute warfarin ingestion. Patients in the activated prothrombin complex concentrate group (enrolled from one hospital) with an international normalized ratio of less than 5 received 500 IU and those with an international normalized ratio greater than 5 received 1,000 IU. Patients in the 4-factor prothrombin complex concentrate (enrolled from a separate hospital) group received the Food and Drug Administration approved dosing algorithm. A total of 158 patients were included in the final analysis (activated prothrombin complex concentrate = 118; 4-factor prothrombin complex concentrate = 40). Those in the 4-factor prothrombin complex concentrate group had a higher pretreatment international normalized ratio (2.7 ± 1.8 vs 3.5 ± 2.9; p = 0.0164). However, the posttreatment international normalized ratio was similar between the groups. In addition, even when controlling for differences in the pretreatment international normalized ratio, there was no difference in the ability to achieve a posttreatment international normalized ratio of less than 1.4 (odds ratio, 0.753 [95% CI, 0.637-0.890]; p

Sorption of organic cations onto silica surfaces over a wide concentration range of competing electrolytes.

PubMed

Kutzner, Susann; Schaffer, Mario; Licha, Tobias; Worch, Eckhard; Börnick, Hilmar

2016-12-15

The fundamental understanding of organic cation-solid phase interactions is essential for improved predictions of the transport and ultimate environmental fates of widely used substances (e.g., pharmaceutical compounds) in the aquatic environment. We report sorption experiments of two cationic model compounds using two silica gels and a natural aquifer sediment. The sorbents were extensively characterized and the results of surface titrations under various background electrolyte concentrations were discussed. The salt dependency of sorption was systematically studied in batch experiments over a wide concentration range (five orders of magnitude) of inorganic ions in order to examine the influence of increasing competition on the sorption of organic cations. The organic cation uptake followed the Freundlich isotherm model and the sorption capacity decreases with an increase in the electrolyte concentration due to the underlying cation exchange processes. However, the sorption recovers considerably at high ionic strength (I>1M). To our knowledge, this effect has not been observed before and appears to be independent from the sorbent characteristics and sorbate structure. Furthermore, the recovery of sorption was attributed to specific, non-ionic interactions and a connection between the sorption coefficient and activity coefficient of the medium is presumed. Eventually, the reasons for the differing sorption affinities of both sorbates are discussed. Copyright © 2016 Elsevier Inc. All rights reserved.

Effects of food availability on serum insulin and lipid concentrations in free-ranging baboons.

PubMed

Kemnitz, Joseph W; Sapolsky, Robert M; Altmann, Jeanne; Muruthi, Philip; Mott, Glen E; Stefanick, Marcia L

2002-05-01

The relationship between food availability and metabolic physiology was studied in groups of free-ranging baboons (Papio spp.) living in the Amboseli National Park and the Masai Mara National Reserve of Kenya. Three groups subsisted entirely on natural forage, while two other groups lived near tourist facilities and often consumed food wastes from these lodges. The refuse provided a very accessible food source with relatively high caloric density. Consumption of the refuse was associated with reduced locomotion. Sexually mature individuals from all five groups were sedated surreptitiously in the early morning and blood samples were collected. Compared to animals foraging exclusively in the wild, animals that supplemented their diet with the refuse items had two- to threefold elevations in serum insulin concentrations, as well as increased total cholesterol (C), HDL-C, and VLDL+LDL-C levels. No sex differences in physiological measures were observed except in body mass. Elevated serum insulin, and cholesterol and lipoprotein concentrations influence the development of cardiovascular disease and have been shown to be subject to dietary manipulation and exercise under controlled conditions. The present results suggest potentially deleterious effects of a highly accessible, calorically dense food source, and associated reduction of physical activity for baboons living in an otherwise natural environment. Copyright 2002 Wiley-Liss, Inc.

SI-traceable calibration-free analysis for the active concentration of G2-EPSPS protein using surface plasmon resonance.

PubMed

Su, Ping; He, Zhangjing; Wu, Liqing; Li, Liang; Zheng, Kangle; Yang, Yi

2018-02-01

concentration range of 1.5-8nM. The appropriate concentration range of G2-EPSPS in the proposed method was determined to be 1.5-8nM. The active G2-EPSPS protein concentration determined by our method was only 17.82% of that obtained by isotope dilution mass spectrometry, showing the active protein was only a small part of the total G2-EPSPS protein. The measurement principle of the proposed method can be clearly described by equations and the measurement result can be expressed in SI units. Therefore, the proposed method shows promise to become a primary method for active protein concentration measurement, which can benefit the development of certified reference materials for active proteins. Copyright © 2017 Elsevier B.V. All rights reserved.

Beyond conventional dose-response curves: Sensorgram comparison in SPR allows single concentration activity and similarity assessment.

PubMed

Gassner, C; Karlsson, R; Lipsmeier, F; Moelleken, J

2018-05-30

Previously we have introduced two SPR-based assay principles (dual-binding assay and bridging assay), which allow the determination of two out of three possible interaction parameters for bispecific molecules within one assay setup: two individual interactions to both targets, and/or one simultaneous/overall interaction, which potentially reflects the inter-dependency of both individual binding events. However, activity and similarity are determined by comparing report points over a concentration range, which also mirrors the way data is generated by conventional ELISA-based methods So far, binding kinetics have not been specifically considered in generic approaches for activity assessment. Here, we introduce an improved slope-ratio model which, together with a sensorgram comparison based similarity assessment, allows the development of a detailed, USP-conformal ligand binding assay using only a single sample concentration. We compare this novel analysis method to the usual concentration-range approach for both SPR-based assay principles and discuss its impact on data quality and increased sample throughput. Copyright © 2018 Elsevier B.V. All rights reserved.

Automatic Echographic Detection of Halloysite Clay Nanotubes in a Low Concentration Range.

PubMed

Conversano, Francesco; Pisani, Paola; Casciaro, Ernesto; Di Paola, Marco; Leporatti, Stefano; Franchini, Roberto; Quarta, Alessandra; Gigli, Giuseppe; Casciaro, Sergio

2016-04-11

Aim of this work was to investigate the automatic echographic detection of an experimental drug delivery agent, halloysite clay nanotubes (HNTs), by employing an innovative method based on advanced spectral analysis of the corresponding "raw" radiofrequency backscatter signals. Different HNT concentrations in a low range (5.5-66 × 10 10 part/mL, equivalent to 0.25-3.00 mg/mL) were dispersed in custom-designed tissue-mimicking phantoms and imaged through a clinically-available echographic device at a conventional ultrasound diagnostic frequency (10 MHz). The most effective response (sensitivity = 60%, specificity = 95%), was found at a concentration of 33 × 10 10 part/mL (1.5 mg/mL), representing a kind of best compromise between the need of enough particles to introduce detectable spectral modifications in the backscattered signal and the necessity to avoid the losses of spectral peculiarity associated to higher HNT concentrations. Based on theoretical considerations and quantitative comparisons with literature-available results, this concentration could also represent an optimal concentration level for the automatic echographic detection of different solid nanoparticles when employing a similar ultrasound frequency. Future dedicated studies will assess the actual clinical usefulness of the proposed approach and the potential of HNTs for effective theranostic applications.

Concentration of enteric virus indicator from seawater using granular activated carbon.

PubMed

Cormier, Jiemin; Gutierrez, Miguel; Goodridge, Lawrence; Janes, Marlene

2014-02-01

Fecal contamination of shellfish growing seawater with enteric viruses is often associated with human outbreaks of gastroenteritis. Male specific bacteriophage MS2 is correlated with those of enteric viruses in a wide range of water environments and has been used widely as a surrogate for pathogenic waterborne viruses. Since viruses in contaminated water are usually at low levels, the development of methods to concentrate viruses from water is crucial for detection purposes. In the present study, granular activated carbon was evaluated for concentration of MS2 from artificial seawater, and different parameters of the seawater were also compared. Recovery of MS2 from warm seawater (37°C) was found to be significantly greater than from cold seawater (4 and 20°C), and even greater than from fresh water (4, 20 and 37°C); the difference between seawater and fresh water became less profound when the temperatures of both were below 37°C. Although not of statistical significance, recovery of MS2 from low salinity seawater (10 and 20 parts per thousand, ppt) was greater than from high salinity seawater (30 and 40ppt). One gram of granular activated carbon was able to extract 6-log plaque forming units (PFU) of MS2 from 500ml seawater at 37°C. This study demonstrated that granular activated carbon can concentrate an enteric virus indicator from shellfish growing seawater effectively. Copyright © 2013 Elsevier B.V. All rights reserved.

Active/passive microwave sensor comparison of MIZ-ice concentration estimates. [Marginal Ice Zone (MIZ)

NASA Technical Reports Server (NTRS)

Burns, B. A.; Cavalieri, D. J.; Keller, M. R.

1986-01-01

Active and passive microwave data collected during the 1984 summer Marginal Ice Zone Experiment in the Fram Strait (MIZEX 84) are used to compare ice concentration estimates derived from synthetic aperture radar (SAR) data to those obtained from passive microwave imagery at several frequencies. The comparison is carried out to evaluate SAR performance against the more established passive microwave technique, and to investigate discrepancies in terms of how ice surface conditions, imaging geometry, and choice of algorithm parameters affect each sensor. Active and passive estimates of ice concentration agree on average to within 12%. Estimates from the multichannel passive microwave data show best agreement with the SAR estimates because the multichannel algorithm effectively accounts for the range in ice floe brightness temperatures observed in the MIZ.

Factors affecting 210Po and 210Pb activity concentrations in mussels and implications for environmental bio-monitoring programmes.

PubMed

Carvalho, Fernando P; Oliveira, João M; Alberto, G

2011-02-01

The activity of (210)Po and (210)Pb was determined in mussels of the same size (3.5-4.0 cm shell length) sampled monthly over a 17-month period at the Atlantic coast of Portugal. Average radionuclide concentration values in mussels were 759±277 Bq kg(-1) for (210)Po (range 460-1470 Bq kg(-1) dry weight), and 45±19 Bq kg(-1) for (210)Pb (range 23-96 Bq kg(-1) dry weight). Environmental parameters and mussel biometric parameters were monitored during the same period. Although there was no seasonal variation of radionuclide concentrations in sea water during the study period, the concentration of radionuclide activity in mussels varied seasonally displaying peaks of high concentrations in winter and low concentrations in summer. Analysis of radionuclide data in relation to the physiological Condition Index of mussels revealed that (210)Po and (210)Pb activities in the mussel (average activity per individual) remained nearly constant during the investigation period, while mussel body weight fluctuated due to fat storage/expenditure in the soft tissues. Similar variation of radionuclide concentrations was observed in mussels transplanted from the sea coast into the Tejo Estuary. However, under estuarine environmental conditions and with higher food availability throughout the year, transplanted mussel Condition Index was higher than in coastal mussels and average radionuclide concentrations were 210±75 Bq kg(-1) (dry weight) for (210)Po and 10±4 Bq kg(-1) (dry weight) for (210)Pb, therefore lower than in coastal mussels with similar shell length. It is concluded that the apparent seasonal fluctuation and inter-site difference of radionuclide concentrations were mostly caused by mussel body weight fluctuation and not by radionuclide body burden fluctuation. This interpretation can be extended to the apparent seasonal fluctuation in concentrations of lipophilic and lipophobic contaminants in mussels, and provides an explanation for occasional high concentrations of

Kinetics of absorption of CO{sub 2} in concentrated aqueous methyldiethanolamine solutions in the range 296 K to 343 K

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

Pani, F.; Gaunand, A.; Cadours, R.

1997-03-01

The kinetics of CO{sub 2} absorption by aqueous solutions of methyl diethanol amine (MDEA) were measured in the temperature range (296--343) K and MDEA concentration range (830--4,380) mol/m{sup 3} (10--50 mass %). A thermoregulated constant interfacial area Lewis-type cell was operated by recording the pressure drop during batch absorption. The kinetic results are in agreement with a fast regime of absorption according to film theory. MDEA depletion at the interface has a significant effect on the kinetics at the CO{sub 2} pressures (100 to 200 kPa) studied in this work, especially at low temperatures and low MDEA concentrations. Considering onlymore » the reaction between CO{sub 2} and MDEA, the CO{sub 2} absorption appears as a first-order reaction with respect to MDEA. The activation energy found for the reaction between CO{sub 2} and MDEA is 45 kJ/mol, but this value depends significantly (by about 10% in the worst case) on the vapor-liquid equilibrium data used.« less

Multi-scale variability and long-range memory in indoor Radon concentrations from Coimbra, Portugal

NASA Astrophysics Data System (ADS)

Donner, Reik V.; Potirakis, Stelios; Barbosa, Susana

2014-05-01

The presence or absence of long-range correlations in the variations of indoor Radon concentrations has recently attracted considerable interest. As a radioactive gas naturally emitted from the ground in certain geological settings, understanding environmental factors controlling Radon concentrations and their dynamics is important for estimating its effect on human health and the efficiency of possible measures for reducing the corresponding exposition. In this work, we re-analyze two high-resolution records of indoor Radon concentrations from Coimbra, Portugal, each of which spans several months of continuous measurements. In order to evaluate the presence of long-range correlations and fractal scaling, we utilize a multiplicity of complementary methods, including power spectral analysis, ARFIMA modeling, classical and multi-fractal detrended fluctuation analysis, and two different estimators of the signals' fractal dimensions. Power spectra and fluctuation functions reveal some complex behavior with qualitatively different properties on different time-scales: white noise in the high-frequency part, indications of some long-range correlated process dominating time scales of several hours to days, and pronounced low-frequency variability associated with tidal and/or meteorological forcing. In order to further decompose these different scales of variability, we apply two different approaches. On the one hand, applying multi-resolution analysis based on the discrete wavelet transform allows separately studying contributions on different time scales and characterize their specific correlation and scaling properties. On the other hand, singular system analysis (SSA) provides a reconstruction of the essential modes of variability. Specifically, by considering only the first leading SSA modes, we achieve an efficient de-noising of our environmental signals, highlighting the low-frequency variations together with some distinct scaling on sub-daily time-scales resembling

Haptoglobin concentrations in free-range and temporarily captive juvenile steller sea lions.

PubMed

Thomton, Jamie D; Mellish, Jo-Ann E

2007-04-01

Haptoglobin (Hp) is an acute-phase protein synthesized in the liver that circulates at elevated concentrations in response to tissue damage caused by inflammation, infection, and trauma. As part of a larger study, sera Hp concentrations were measured in temporarily captive (n = 21) and free-range (n = 38) western stock juvenile Steller sea lions (Eumetopias jubatus) sampled from 2003 to 2006. Baseline Hp concentration at time of capture was 133.3 +/- 17.4 mg/dl. Temporarily captive animals exhibited a 3.2-fold increase in Hp concentrations during the first 4 wk of captivity, followed by a return to entry levels by week 5. Haptoglobin levels were not influenced by age, season, or parasite load. There was a significant positive correlation between Hp concentrations and white blood cell count (P < 0.001) and globulin levels (P < 0.001) and a negative correlation to red blood cell count and hematocrit (P < 0.001 for both). There was no correlation between Hp levels and platelet count (P = 0.095) or hemoglobin (P = 0.457). Routine blubber biopsies collected under gas anesthesia did not produce a measurable Hp response. One animal with a large abscess had an Hp spike of 1,006.0 mg/dl that returned to entry levels after treatment. In conclusion, serum Hp levels correlate to the stable clinical health status observed during captivity, with moderate Hp response during capture and initial acclimation to captivity and acute response to inflammation and infection.

Antiandrogenic activity of phthalate mixtures: Validity of concentration addition

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

Christen, Verena; Crettaz, Pierre; Oberli-Schrämmli, Aurelia

2012-03-01

Phthalates and bisphenol A have very widespread use leading to significant exposure of humans. They are suspected to interfere with the endocrine system, including the androgen, estrogen and the thyroid hormone system. Here we analyzed the antiandrogenic activity of six binary, and one ternary mixture of phthalates exhibiting complete antiandrogenic dose–response curves, and binary mixtures of phthalates and bisphenol A at equi-effective concentrations of EC{sub 10}, EC{sub 25} and EC{sub 50} in MDA-kb2 cells. Mixture activity followed the concentration addition (CA) model with a tendency to synergism at high and antagonism at low concentrations. Isoboles and the toxic unit approachmore » (TUA) confirmed the additive to synergistic activity of the binary mixtures BBP + DBP, DBP + DEP and DEP + BPA at high concentrations. Both methods indicate a tendency to antagonism for the EC{sub 10} mixtures BBP + DBP, BBP + DEP and DBP + DEP, and the EC{sub 25} mixture of DBP + BPA. A ternary mixture revealed synergism at the EC{sub 50}, and weak antagonistic activity at the EC{sub 25} level by the TUA. A mixture of five phthalates representing a human urine composition and reflecting exposure to corresponding parent compounds showed no antiandrogenic activity. Our study demonstrates that CA is an appropriate concept to account for mixture effects of antiandrogenic phthalates and bisphenol A. The interaction indicates a departure from additivity to antagonism at low concentrations, probably due to interaction with the androgen receptor and/or cofactors. This study emphasizes that a risk assessment of phthalates should account for mixture effects by applying the CA concept. -- Highlights: ► Antiandrogenic activity of mixtures of 2 and 3 phthalates are assessed in MDA-kb2 cells. ► Mixture activities followed the concentration addition model. ► A tendency to synergism at high and antagonism at low levels occurred.« less

Alteration of natural (37)Ar activity concentration in the subsurface by gas transport and water infiltration.

PubMed

Guillon, Sophie; Sun, Yunwei; Purtschert, Roland; Raghoo, Lauren; Pili, Eric; Carrigan, Charles R

2016-05-01

High (37)Ar activity concentration in soil gas is proposed as a key evidence for the detection of underground nuclear explosion by the Comprehensive Nuclear Test-Ban Treaty. However, such a detection is challenged by the natural background of (37)Ar in the subsurface, mainly due to Ca activation by cosmic rays. A better understanding and improved capability to predict (37)Ar activity concentration in the subsurface and its spatial and temporal variability is thus required. A numerical model integrating (37)Ar production and transport in the subsurface is developed, including variable soil water content and water infiltration at the surface. A parameterized equation for (37)Ar production in the first 15 m below the surface is studied, taking into account the major production reactions and the moderation effect of soil water content. Using sensitivity analysis and uncertainty quantification, a realistic and comprehensive probability distribution of natural (37)Ar activity concentrations in soil gas is proposed, including the effects of water infiltration. Site location and soil composition are identified as the parameters allowing for a most effective reduction of the possible range of (37)Ar activity concentrations. The influence of soil water content on (37)Ar production is shown to be negligible to first order, while (37)Ar activity concentration in soil gas and its temporal variability appear to be strongly influenced by transient water infiltration events. These results will be used as a basis for practical CTBTO concepts of operation during an OSI. Copyright © 2016 Elsevier Ltd. All rights reserved.

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

PubMed

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

2016-01-01

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

Adsorption-desorption mediated separation of low concentrated D2O from water with hydrophobic activated carbon fiber.

PubMed

Ono, Yuji; Futamura, Ryusuke; Hattori, Yoshiyuki; Sakai, Toshio; Kaneko, Katsumi

2017-12-15

The adsorption and desorption of D 2 O on hydrophobic activated carbon fiber (ACF) occurs at a smaller pressure than the adsorption and desorption of H 2 O. The behavior of the critical desorption pressure difference between D 2 O and H 2 O in the pressure range of 1.25-1.80kPa is applied to separate low concentrated D 2 O from water using the hydrophobic ACF, because the desorption branches of D 2 O and H 2 O drop almost vertically. The deuterium concentration of all desorbed water in the above pressure range is lower than that of water without adsorption-treatment on ACF. The single adsorption-desorption procedure on ACF at 1.66kPa corresponding to the maximum difference of adsorption amount between D 2 O and H 2 O reduced the deuterium concentration of desorbed water to 130.6ppm from 143.0ppm. Thus, the adsorption-desorption procedure of water on ACF is a promising separation and concentration method of low concentrated D 2 O from water. Copyright © 2017 Elsevier Inc. All rights reserved.

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.

High concentrations of single-walled carbon nanotubes lower soil enzyme activity and microbial biomass.

PubMed

Jin, Lixia; Son, Yowhan; Yoon, Tae Kyung; Kang, Yu Jin; Kim, Woong; Chung, Haegeun

2013-02-01

Nanomaterials such as single-walled carbon nanotubes (SWCNTs) may enter the soil environment with unknown consequences resulting from the development of nanotechnology for a variety of applications. We determined the effects of SWCNTs on soil enzyme activity and microbial biomass through a 3-week incubation of urban soils treated with different concentrations of SWCNTs ranging from 0 to 1000 μg g(-1) soil. The activities of cellobiohydrolase, β-1,4-glucosidase, β-1,4-xylosidase, β-1,4-N-acetylglucosaminidase, L-leucine aminopeptidase, and acid phosphatase and microbial biomass were measured in soils treated with powder and suspended forms of SWCNTs. SWCNTs of concentrations at 300-1000 μg g(-1) soil significantly lowered activities of most enzymes and microbial biomass. It is noteworthy that the SWCNTs showed similar effects to that of multi-walled carbon nanotubes (MWCNTs), but at a concentration approximately 5 times lower; we suggest that this is mainly due to the higher surface area of SWCNTs than that of MWCNTs. Indeed, our results show that surface area of CNTs has significant negative relationship with relative enzyme activity and biomass, which suggests that greater microorganism-CNT interactions could increase the negative effect of CNTs on microorganisms. Current work may contribute to the preparation of a regulatory guideline for the release of CNTs to the soil environment. Copyright © 2012 Elsevier Inc. All rights reserved.

Fast range estimation based on active range-gated imaging for coastal surveillance

NASA Astrophysics Data System (ADS)

Kong, Qingshan; Cao, Yinan; Wang, Xinwei; Tong, Youwan; Zhou, Yan; Liu, Yuliang

2012-11-01

Coastal surveillance is very important because it is useful for search and rescue, illegal immigration, or harbor security and so on. Furthermore, range estimation is critical for precisely detecting the target. Range-gated laser imaging sensor is suitable for high accuracy range especially in night and no moonlight. Generally, before detecting the target, it is necessary to change delay time till the target is captured. There are two operating mode for range-gated imaging sensor, one is passive imaging mode, and the other is gate viewing mode. Firstly, the sensor is passive mode, only capturing scenes by ICCD, once the object appears in the range of monitoring area, we can obtain the course range of the target according to the imaging geometry/projecting transform. Then, the sensor is gate viewing mode, applying micro second laser pulses and sensor gate width, we can get the range of targets by at least two continuous images with trapezoid-shaped range intensity profile. This technique enables super-resolution depth mapping with a reduction of imaging data processing. Based on the first step, we can calculate the rough value and quickly fix delay time which the target is detected. This technique has overcome the depth resolution limitation for 3D active imaging and enables super-resolution depth mapping with a reduction of imaging data processing. By the two steps, we can quickly obtain the distance between the object and sensor.

The impact of military activities on the concentration of mercury in soils of military training grounds and marine sediments.

PubMed

Gębka, Karolina; Bełdowski, Jacek; Bełdowska, Magdalena

2016-11-01

Military activities have been conducted on land and at sea. Both during conflicts and in peace time, some regions served as a military training ground which included firing positions and bunkers. Mercury fulminate has been used in ammunition primers and detonators. Certain amount of ammunition was dumped into the Baltic Sea after the Second World War. Because of corroded containers, mercury can be released into the marine environment. The soil and sediment samples were taken from military training grounds, southern Baltic in 2014 and 2015. The concentration of mercury was determined by AMA-254 analyzer. Hg concentration was higher in the places of military activities, as compared to other areas. Ten times increased concentration of Hg was determined in soil sample collected in area of active gun range compared to the reference station. The significant higher concentration of mercury was detected in stations where chemical warfare agents were found.

Scale dependence of the mechanics of active gels with increasing motor concentration.

PubMed

Sonn-Segev, Adar; Bernheim-Groswasser, Anne; Roichman, Yael

2017-10-18

Actin is a protein that plays an essential role in maintaining the mechanical integrity of cells. In response to strong external stresses, it can assemble into large bundles, but it grows into a fine branched network to induce cell motion. In some cases, the self-organization of actin fibers and networks involves the action of bipolar filaments of the molecular motor myosin. Such self-organization processes mediated by large myosin bipolar filaments have been studied extensively in vitro. Here we create active gels, composed of single actin filaments and small myosin bipolar filaments. The active steady state in these gels persists long enough to enable the characterization of their mechanical properties using one and two point microrheology. We study the effect of myosin concentration on the mechanical properties of this model system for active matter, for two different motor assembly sizes. In contrast to previous studies of networks with large motor assemblies, we find that the fluctuations of tracer particles embedded in the network decrease in amplitude as motor concentration increases. Nonetheless, we show that myosin motors stiffen the actin networks, in accordance with bulk rheology measurements of networks containing larger motor assemblies. This implies that such stiffening is of universal nature and may be relevant to a wider range of cytoskeleton-based structures.

Measurements of radon activity concentration in mouse tissues and organs.

PubMed

Ishimori, Yuu; Tanaka, Hiroshi; Sakoda, Akihiro; Kataoka, Takahiro; Yamaoka, Kiyonori; Mitsunobu, Fumihiro

2017-05-01

The purpose of this study is to investigate the biokinetics of inhaled radon, radon activity concentrations in mouse tissues and organs were determined after mice had been exposed to about 1 MBq/m 3 of radon in air. Radon activity concentrations in mouse blood and in other tissues and organs were measured with a liquid scintillation counter and with a well-type HP Ge detector, respectively. Radon activity concentration in mouse blood was 0.410 ± 0.016 Bq/g when saturated with 1 MBq/m 3 of radon activity concentration in air. In addition, average partition coefficients obtained were 0.74 ± 0.19 for liver, 0.46 ± 0.13 for muscle, 9.09 ± 0.49 for adipose tissue, and 0.22 ± 0.04 for other organs. With these results, a value of 0.414 for the blood-to-air partition coefficient was calculated by means of our physiologically based pharmacokinetic model. The time variation of radon activity concentration in mouse blood during exposure to radon was also calculated. All results are compared in detail with those found in the literature.

High-Flow-Rate Impinger for the Study of Concentration, Viability, Metabolic Activity, and Ice-Nucleation Activity of Airborne Bacteria.

PubMed

Šantl-Temkiv, Tina; Amato, Pierre; Gosewinkel, Ulrich; Thyrhaug, Runar; Charton, Anaïs; Chicot, Benjamin; Finster, Kai; Bratbak, Gunnar; Löndahl, Jakob

2017-10-03

The study of airborne bacteria relies on a sampling strategy that preserves their integrity and in situ physiological state, e.g. viability, cultivability, metabolic activity, and ice-nucleation activity. Because ambient air harbors low concentrations of bacteria, an effective bioaerosol sampler should have a high sampling efficiency and a high airflow. We characterize a high-flow-rate impinger with respect to particle collection and retention efficiencies in the range 0.5-3.0 μm, and we investigated its ability to preserve the physiological state of selected bacterial species and seawater bacterial community in comparison with four commercial bioaerosol samplers. The collection efficiency increased with particle size and the cutoff diameter was between 0.5 and 1 μm. During sampling periods of 120-300 min, the impinger retained the cultivability, metabolic activity, viability, and ice-nucleation activity of investigated bacteria. Field studies in semiurban, high-altitude, and polar environments included periods of low bacterial air concentrations, thus demonstrating the benefits of the impinger's high flow rate. In conclusion, the impinger described here has many advantages compared with other bioaerosol samplers currently on the market: a potential for long sampling time, a high flow rate, a high sampling and retention efficiency, low costs, and applicability for diverse downstream microbiological and molecular analyses.

Transition temperature range of thermally activated nickel-titanium archwires

PubMed Central

SPINI, Tatiana Sobottka; VALARELLI, Fabrício Pinelli; CANÇADO, Rodrigo Hermont; de FREITAS, Karina Maria Salvatore; VILLARINHO, Denis Jardim

2014-01-01

Objectives The shape memory resulting from the superelasticity and thermoelastic effect is the main characteristic of thermally activated NiTi archwires and is closely related to the transition temperature range (TTR). The aim of this study was to evaluate the TTR of thermally activated NiTi archwires commercially available. Material and Methods Seven different brands of 0.019"x0.025" thermally activated nickel-titanium archwires were tested as received by differential scanning calorimetry (DSC) over the temperature range from -100°C to 150°C at 10°C/min. Results All thermally activated NiTi archwires analyzed presented stage transformation during thermal scanning with final austenitic temperature (Af) ranging from 20.39°C to 45.42°C. Three brands of NiTi archwires presented Af close to the room temperature and, this way, do not present properties of shape memory and pseudoelasticity that are desirable in clinical applications. Conclusions The thermally activated NiTi archwires present great variability in the TTR and the elastic parameters of each NiTi archwire should be provided by the manufacturers, to allow achievement of the best clinical performance possible. PMID:24676581

The activity concentration of 210Po in Romanian commercial cigarettes and the radiation exposure estimation derived from their regular consumption.

PubMed

Begy, R Cs; Somlai, J; Kovacs, T; Dumitru Rusu, O A; Cosma, C

2013-11-01

Due to the relatively high activity concentrations of (210)Po that are found in tobacco, cigarette smoking has been found to be the principal pathway of the intake of this radionuclide. The (210)Po concentrations in the lung tissues may contribute significantly to an increase in the internal radiation dose and in the number of instances of lung cancer observed among smokers. The study of (210)Po in tobacco is required due to its potential for human radiation exposure through ingestion and inhalation. The risk factor caused by (210)Po in Romanian commercial cigarettes is not yet evaluated. Ten of the most frequently smoked brands of cigarettes sold in Romania were investigated in this work for this purpose. The activity concentration of (210)Po was determined by alpha spectrometry using a PIPS detector after chemical leaching and spontaneous deposition of (210)Po on a stainless steel disc from diluted HCl solution. The samples were spiked with (209)Po for chemical recovery calculation. The (210)Po activity concentrations of the measured types of cigarettes ranged from 4.65 to 10.22 mBq sample(-1) and the resulted average concentration of (210)Po isotopes is 8.35±0.80 mBq cigarette(-1) (the errors form a 2σ interval of confidence). When comparing the results of this study with the activity concentration values reported by other countries it was found that the results of this study are in the lower end of the world range. The estimation of this study shows that cigarette smokers, who are smoking one pack (20 cigarettes) per day, are exposed to an effective dose of 75.51 μSv y(-1).

Validation of an immunoassay to measure plasminogen-activator inhibitor-1 concentrations in human saliva

PubMed Central

Zhang, Xi; Dimeski, Goce; Punyadeera, Chamindie

2014-01-01

Introduction: We have previously shown that the concentrations of D-dimer are significantly elevated in saliva compared with plasma. Saliva offers several advantages compared with blood analysis. We hypothesised that human saliva contains plasminogen activator inhibitor-1 (PAI-1) and that the concentrations are not affected by the time of saliva collection. The aim was to adopt and validate an immunoassay to quantify PAI-1 concentrations in saliva and to determine whether saliva collection time has an influence in the measurement. Materials and methods: Two saliva samples (morning and afternoon) from the same day were collected from healthy subjects (N = 40) who have had no underlying heart conditions. A customized AlphaLISA® immunoassay (PerkinElmer®, MA, USA) was adopted and used to quantify PAI-1 concentrations. We validated the analytical performance of the customized immunoassay by calculating recovery of known amount of analyte spiked in saliva. Results: The recovery (95.03%), intra- (8.59%) and inter-assay (7.52%) variations were within the acceptable ranges. The median salivary PAI-1 concentrations were 394 pg/mL (interquartile ranges (IQR) 243.4–833.1 pg/mL) in the morning and 376 (129.1–615.4) pg/mL in the afternoon and the plasma concentration was 59,000 (24,000–110,000) pg/mL. Salivary PAI-1 did not correlate with plasma (P = 0.812). Conclusions: The adopted immunoassay produced acceptable assay sensitivity and specificity. The data demonstrated that saliva contains PAI-1 and that its concentration is not affected by the time of saliva collection. There is no correlation between salivary and plasma PAI-1 concentrations. Further studies are required to demonstrate the utility of salivary PAI-1 in CVD risk factor studies. PMID:24969919

Antioxidant Activities of Functional Beverage Concentrates Containing Herbal Medicine Extracts.

PubMed

Park, Seon-Joo; Kim, Mi-Ok; Kim, Jung Hoan; Jeong, Sehyun; Kim, Min Hee; Yang, Su-Jin; Lee, Jongsung; Lee, Hae-Jeung

2017-03-01

This study investigated the antioxidant activity of functional beverage concentrates containing herbal medicine extracts (FBCH) using various antioxidant assays, such as 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radical scavenging activity, and reducing power assay. The total polyphenolic content of FBCH (81.45 mg/100 g) was higher than Ssanghwa tea (SHT, 37.56 mg/100 g). The antioxidant activities of FBCH showed 52.92% DPPH and 55.18% ABTS radical scavenging activities at 100 mg/mL, respectively. FBCH showed significantly higher antioxidant activities compared to the SHT (DPPH, 23.43%; ABTS, 22.21%; reducing power optical density; 0.23, P <0.05). In addition, intracellular reactive oxygen species generation significantly decreased in a concentration-dependent manner following FBCH treatment. These results suggest that the addition of herbal medicine extract contributes to the improved functionality of beverage concentrates.

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...

A novel active-passive sampling approach for measuring time-averaged concentrations of pollutants in water.

PubMed

Amato, Elvio D; Covaci, Adrian; Town, Raewyn M; Hereijgers, Jonas; Bellekens, Ben; Giacometti, Valentina; Breugelmans, Tom; Weyn, Maarten; Dardenne, Freddy; Bervoets, Lieven; Blust, Ronny

2018-06-14

Passive sampling with in situ devices offers several advantages over traditional sampling methods (i.e., discrete spot sampling), however, data interpretation from conventional passive samplers is hampered by difficulties in estimating the thickness of the diffusion layer at the sampler/medium interface (δ), often leading to inaccurate determinations of target analyte concentrations. In this study, the performance of a novel device combining active and passive sampling was investigated in the laboratory. The active-passive sampling (APS) device is comprised of a diffusion cell fitted with a pump and a flowmeter. Three receiving phases traditionally used in passive sampling devices (i.e., chelex resin, Oasis HLB, and silicone rubber), were incorporated in the diffusion cell and allowed the simultaneous accumulation of cationic metals, polar, and non-polar organic compounds, respectively. The flow within the diffusion cell was accurately controlled and monitored, and, combined with diffusion coefficients measurements, enabled the average δ to be estimated. Strong agreement between APS and time-averaged total concentrations measured in discrete water samples was found for most of the substances investigated. Accuracies for metals ranged between 87 and 116%, except Cu and Pb (∼50%), whilst accuracies between 64 and 101%, and 92 and 151% were achieved for polar and non-polar organic compounds, respectively. These results indicate that, via a well-defined in situ preconcentration step, the proposed APS approach shows promise for monitoring the concentration of a range of pollutants in water. Copyright © 2018 Elsevier Ltd. All rights reserved.

Feasible Muscle Activation Ranges Based on Inverse Dynamics Analyses of Human Walking

PubMed Central

Simpson, Cole S.; Sohn, M. Hongchul; Allen, Jessica L.; Ting, Lena H.

2015-01-01

Although it is possible to produce the same movement using an infinite number of different muscle activation patterns owing to musculoskeletal redundancy, the degree to which observed variations in muscle activity can deviate from optimal solutions computed from biomechanical models is not known. Here, we examined the range of biomechanically permitted activation levels in individual muscles during human walking using a detailed musculoskeletal model and experimentally-measured kinetics and kinematics. Feasible muscle activation ranges define the minimum and maximum possible level of each muscle’s activation that satisfy inverse dynamics joint torques assuming that all other muscles can vary their activation as needed. During walking, 73% of the muscles had feasible muscle activation ranges that were greater than 95% of the total muscle activation range over more than 95% of the gait cycle, indicating that, individually, most muscles could be fully active or fully inactive while still satisfying inverse dynamics joint torques. Moreover, the shapes of the feasible muscle activation ranges did not resemble previously-reported muscle activation patterns nor optimal solutions, i.e. static optimization and computed muscle control, that are based on the same biomechanical constraints. Our results demonstrate that joint torque requirements from standard inverse dynamics calculations are insufficient to define the activation of individual muscles during walking in healthy individuals. Identifying feasible muscle activation ranges may be an effective way to evaluate the impact of additional biomechanical and/or neural constraints on possible versus actual muscle activity in both normal and impaired movements. PMID:26300401

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

NASA Astrophysics Data System (ADS)

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

2016-09-01

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

Athletic Activity and Hormone Concentrations in High School Female Athletes

PubMed Central

Wojtys, Edward M.; Jannausch, Mary L.; Kreinbrink, Jennifer L.; Harlow, Siobán D.; Sowers, MaryFran R.

2015-01-01

Context: Physical activity may affect the concentrations of circulating endogenous hormones in female athletes. Understanding the relationship between athletic and physical activity and circulating female hormone concentrations is critical. Objective: To test the hypotheses that (1) the estradiol-progesterone profile of high school adolescent girls participating in training, conditioning, and competition would differ from that of physically inactive, age-matched adolescent girls throughout a 3-month period; and (2) athletic training and conditioning would alter body composition (muscle, bone), leading to an increasingly greater lean–body-mass to fat–body-mass ratio with accompanying hormonal changes. Design: Cohort study. Settings: Laboratory and participants' homes. Patients or Other Participants: A total of 106 adolescent girls, ages 14–18 years, who had experienced at least 3 menstrual cycles in their lifetime. Main Outcome Measure(s): Participants were prospectively monitored throughout a 13-week period, with weekly physical activity assessments and 15 urine samples for estrogen, luteinizing hormone, creatinine, and progesterone concentrations. Each girl underwent body-composition measurements before and after the study period. Results: Seventy-four of the 98 girls (76%) who completed the study classified themselves as athletes. Body mass index, body mass, and fat measures remained stable, and 17 teenagers had no complete menstrual cycle during the observation period. Mean concentrations of log(estrogen/creatinine) were slightly greater in nonathletes who had cycles of <24 or >35 days. Mean log(progesterone/creatinine) concentrations in nonathletes were less in the first half and greater in the second half of the cycle, but the differences were not statistically significant. Conclusions: A moderate level of athletic or physical activity did not influence urine concentrations of estrogen, progesterone, or luteinizing hormones. However, none of the

Inhibitory effect of high calcium concentration on municipal solid waste leachate treatment by the activated sludge process.

PubMed

Xia, Yi; He, Pin Jing; Pu, Hong Xia; Lü, Fan; Shao, Li Ming; Zhang, Hua

2017-05-01

This research focused on the inhibitory effects of Ca on the aerobic biological treatment of landfill leachate containing extremely high Ca concentrations. When the Ca concentration in leachate to be treated was more than 4500 mg l -1 , the total organic carbon removal rate was significantly reduced and the processing time to achieve the same removal efficiency was 1.4 times that in the control treatment without added Ca. In contrast, the total nitrogen and ammonia nitrogen (NH 4 + -N) removal efficiencies were positively related to the Ca concentration, increasing from 65.2% to 81.2% and from 69.2% to 83.7%, respectively, when the dosage of added Ca increased from zero to 8000 mg l -1 . During aerobic treatment, the reductions of solution Ca concentration were in the range of 1003-2274 mg l -1 and were matched with increases in the Ca content in the residual sludge. The inhibition threshold of Ca in the leachate treated by the activated sludge process appeared to be 4500 mg l -1 , which could be realized by controlling the influent Ca concentration and using an appropriate sludge return ratio in the activated sludge process.

The dynamic range of response set activation during action sequencing.

PubMed

Behmer, Lawrence P; Crump, Matthew J C

2017-03-01

We show that theories of response scheduling for sequential action can be discriminated on the basis of their predictions for the dynamic range of response set activation during sequencing, which refers to the momentary span of activation states for completed and to-be-completed actions in a response set. In particular, theories allow that future actions in a plan are partially activated, but differ with respect to the width of the range, which refers to the number of future actions that are partially activated. Similarly, theories differ on the width of the range for recently completed actions that are assumed to be rapidly deactivated or gradually deactivated in a passive fashion. We validate a new typing task for measuring momentary activation states of actions across a response set during action sequencing. Typists recruited from Amazon Mechanical Turk copied a paragraph by responding to a "go" signal that usually cued the next letter but sometimes cued a near-past or future letter (n-3, -2, -1, 0, +2, +3). The activation states for producing letters across go-signal positions can be inferred from RTs and errors. In general, we found evidence of graded parallel activation for future actions and rapid deactivation of more distal past actions. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Activity concentration measurements using a conjugate gradient (Siemens xSPECT) reconstruction algorithm in SPECT/CT.

PubMed

Armstrong, Ian S; Hoffmann, Sandra A

2016-11-01

The interest in quantitative single photon emission computer tomography (SPECT) shows potential in a number of clinical applications and now several vendors are providing software and hardware solutions to allow 'SUV-SPECT' to mirror metrics used in PET imaging. This brief technical report assesses the accuracy of activity concentration measurements using a new algorithm 'xSPECT' from Siemens Healthcare. SPECT/CT data were acquired from a uniform cylinder with 5, 10, 15 and 20 s/projection and NEMA image quality phantom with 25 s/projection. The NEMA phantom had hot spheres filled with an 8 : 1 activity concentration relative to the background compartment. Reconstructions were performed using parameters defined by manufacturer presets available with the algorithm. The accuracy of activity concentration measurements was assessed. A dose calibrator-camera cross-calibration factor (CCF) was derived from the uniform phantom data. In uniform phantom images, a positive bias was observed, ranging from ∼6% in the lower count images to ∼4% in the higher-count images. On the basis of the higher-count data, a CCF of 0.96 was derived. As expected, considerable negative bias was measured in the NEMA spheres using region mean values whereas positive bias was measured in the four largest NEMA spheres. Nonmonotonically increasing recovery curves for the hot spheres suggested the presence of Gibbs edge enhancement from resolution modelling. Sufficiently accurate activity concentration measurements can easily be measured on images reconstructed with the xSPECT algorithm without a CCF. However, the use of a CCF is likely to improve accuracy further. A manual conversion of voxel values into SUV should be possible, provided that the patient weight, injected activity and time between injection and imaging are all known accurately.

Sedentary behavior, physical activity, and concentrations of insulin among US adults.

PubMed

Ford, Earl S; Li, Chaoyang; Zhao, Guixiang; Pearson, William S; Tsai, James; Churilla, James R

2010-09-01

Time spent watching television has been linked to obesity, metabolic syndrome, and diabetes, all conditions characterized to some degree by hyperinsulinemia and insulin resistance. However, limited evidence relates screen time (watching television or using a computer) directly to concentrations of insulin. We examined the cross-sectional associations between time spent watching television or using a computer, physical activity, and serum concentrations of insulin using data from 2800 participants aged at least 20 years of the 2003-2006 National Health and Nutrition Examination Survey. The amount of time spent watching television and using a computer as well as physical activity was self-reported. The unadjusted geometric mean concentration of insulin increased from 6.2 microU/mL among participants who did not watch television to 10.0 microU/mL among those who watched television for 5 or more hours per day (P = .001). After adjustment for age, sex, race or ethnicity, educational status, concentration of cotinine, alcohol intake, physical activity, waist circumference, and body mass index using multiple linear regression analysis, the log-transformed concentrations of insulin were significantly and positively associated with time spent watching television (P = < .001). Reported time spent using a computer was significantly associated with log-transformed concentrations of insulin before but not after accounting for waist circumference and body mass index. Leisure-time physical activity but not transportation or household physical activity was significantly and inversely associated with log-transformed concentrations of insulin. Sedentary behavior, particularly the amount of time spent watching television, may be an important modifiable determinant of concentrations of insulin. Published by Elsevier Inc.

Radiological hazards of Narghile (hookah, shisha, goza) smoking: activity concentrations and dose assessment.

PubMed

Khater, Ashraf E M; Abd El-Aziz, Nawal S; Al-Sewaidan, Hamed A; Chaouachi, Kamal

2008-12-01

Narghile (hookah, shisha, goza, "water-pipe") smoking has become fashionable worldwide. Its tobacco pastes, known as moassel and jurak, are not standardized and generally contain about 30-50% (sometimes more) tobacco, molasses/juice of sugarcane, various spices and dried fruits (particularly in jurak) and, in the case of moassel, glycerol and flavoring essences. Tobacco contains minute amounts of radiotoxic elements such as (210)Pb, (210)Po and uranium, which are inhaled via smoking. Only very few data have been published on the concentrations of natural radionuclides in narghile tobacco mixtures. Consequently, the aim of this study was to draw first conclusions on the potential hazards of radioactivity in moassel tobacco in relation to narghile smoking. The results indicate the existence of a wide range in the radioactivity contents where the average (range) activity concentrations of (238)U, (234)Th (226)Ra, (210)Pb, (210)Po, (232)Th and (40)K, in Bq/kg dry weight were 55 (19-93), 11 (3-23), 3 (1.2-8), 14 (3-29), 13 (7-32), 7 (4-10) and 719 (437-1044)Bq/kg dry weight, respectively. The average concentrations of natural radionuclides in moassel tobacco pastes are comparable to their concentration in Greek cigarettes and tobacco leaves, and lower than that of Brazilian tobacco leaves. The distribution pattern of these radionuclides after smoking, between smoke, ash and filter, is unknown, except for (210)Po during cigarette smoking and from one existing study during moassel smoking. Radiological dose assessment due to intake of natural radionuclides was calculated and the possible radio-toxicity of the measured radionuclides is briefly discussed.

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

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

The status of photovoltaic concentrator development

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

Maish, A. B.

1992-10-01

Several companies in the United States are actively pursuing the commercialization of photovoltaic concentrator technology. Under the auspices of the US Department of Energy`s Concentrator Initiative, the Electric Power Research Institute`s High Concentration Photovoltaic Program and several privately funded programs, these companies are developing a range of designs from low-concentration linear-focus to high-concentration point-focus cells and collectors. Design details and status of each development program is presented.

Response of oxidative enzyme activities to nitrogen deposition affects soil concentrations of dissolved organic carbon

USGS Publications Warehouse

Waldrop, M.P.; Zak, D.R.

2006-01-01

Recent evidence suggests that atmospheric nitrate (NO3- ) deposition can alter soil carbon (C) storage by directly affecting the activity of lignin-degrading soil fungi. In a laboratory experiment, we studied the direct influence of increasing soil NO 3- concentration on microbial C cycling in three different ecosystems: black oak-white oak (BOWO), sugar maple-red oak (SMRO), and sugar maple-basswood (SMBW). These ecosystems span a broad range of litter biochemistry and recalcitrance; the BOWO ecosystem contains the highest litter lignin content, SMRO had intermediate lignin content, and SMBW leaf litter has the lowest lignin content. We hypothesized that increasing soil solution NO 3- would reduce lignolytic activity in the BOWO ecosystem, due to a high abundance of white-rot fungi and lignin-rich leaf litter. Due to the low lignin content of litter in the SMBW, we further reasoned that the NO3- repression of lignolytic activity would be less dramatic due to a lower relative abundance of white-rot basidiomycetes; the response in the SMRO ecosystem should be intermediate. We increased soil solution NO3- concentrations in a 73-day laboratory incubation and measured microbial respiration and soil solution dissolved organic carbon (DOC) and phenolics concentrations. At the end of the incubation, we measured the activity of ??-glucosidase, N-acetyl-glucosaminidase, phenol oxidase, and peroxidase, which are extracellular enzymes involved with cellulose and lignin degradation. We quantified the fungal biomass, and we also used fungal ribosomal intergenic spacer analysis (RISA) to gain insight into fungal community composition. In the BOWO ecosystem, increasing NO 3- significantly decreased oxidative enzyme activities (-30% to -54%) and increased DOC (+32% upper limit) and phenolic (+77% upper limit) concentrations. In the SMRO ecosystem, we observed a significant decrease in phenol oxidase activity (-73% lower limit) and an increase in soluble phenolic concentrations

Plackett-Burman Design for rGILCC1 Laccase Activity Enhancement in Pichia pastoris: Concentrated Enzyme Kinetic Characterization

PubMed Central

Morales-Álvarez, Edwin D.; Rivera-Hoyos, Claudia M.; Cardozo-Bernal, Ángela M.; Pedroza-Rodríguez, Aura M.; Díaz-Rincón, Dennis J.; Rodríguez-López, Alexander; Alméciga-Díaz, Carlos J.; Cuervo-Patiño, Claudia L.

2017-01-01

Laccases are multicopper oxidases that catalyze aromatic and nonaromatic compounds with concomitant reduction of molecular oxygen to water. They are of great interest due to their potential biotechnological applications. In this work we statistically improved culture media for recombinant GILCC1 (rGILCC1) laccase production at low scale from Ganoderma lucidum containing the construct pGAPZαA-GlucPost-Stop in Pichia pastoris. Temperature, pH stability, and kinetic parameter characterizations were determined by monitoring concentrate enzyme oxidation at different ABTS substrate concentrations. Plackett-Burman Design allowed improving enzyme activity from previous work 36.08-fold, with a laccase activity of 4.69 ± 0.39 UL−1 at 168 h of culture in a 500 mL shake-flask. Concentrated rGILCC1 remained stable between 10 and 50°C and retained a residual enzymatic activity greater than 70% at 60°C and 50% at 70°C. In regard to pH stability, concentrated enzyme was more stable at pH 4.0 ± 0.2 with a residual activity greater than 90%. The lowest residual activity greater than 55% was obtained at pH 10.0 ± 0.2. Furthermore, calculated apparent enzyme kinetic parameters were a Vmax of 6.87 × 10−5 mM s−1, with an apparent Km of 5.36 × 10−2 mM. Collectively, these important stability findings open possibilities for applications involving a wide pH and temperature ranges. PMID:28421142

Plackett-Burman Design for rGILCC1 Laccase Activity Enhancement in Pichia pastoris: Concentrated Enzyme Kinetic Characterization.

PubMed

Morales-Álvarez, Edwin D; Rivera-Hoyos, Claudia M; Cardozo-Bernal, Ángela M; Poutou-Piñales, Raúl A; Pedroza-Rodríguez, Aura M; Díaz-Rincón, Dennis J; Rodríguez-López, Alexander; Alméciga-Díaz, Carlos J; Cuervo-Patiño, Claudia L

2017-01-01

Laccases are multicopper oxidases that catalyze aromatic and nonaromatic compounds with concomitant reduction of molecular oxygen to water. They are of great interest due to their potential biotechnological applications. In this work we statistically improved culture media for recombinant GILCC1 (rGILCC1) laccase production at low scale from Ganoderma lucidum containing the construct pGAPZ α A- GlucPost -Stop in Pichia pastoris . Temperature, pH stability, and kinetic parameter characterizations were determined by monitoring concentrate enzyme oxidation at different ABTS substrate concentrations. Plackett-Burman Design allowed improving enzyme activity from previous work 36.08-fold, with a laccase activity of 4.69 ± 0.39 UL -1 at 168 h of culture in a 500 mL shake-flask. Concentrated rGILCC1 remained stable between 10 and 50°C and retained a residual enzymatic activity greater than 70% at 60°C and 50% at 70°C. In regard to pH stability, concentrated enzyme was more stable at pH 4.0 ± 0.2 with a residual activity greater than 90%. The lowest residual activity greater than 55% was obtained at pH 10.0 ± 0.2. Furthermore, calculated apparent enzyme kinetic parameters were a V max of 6.87 × 10 -5  mM s -1 , with an apparent K m of 5.36 × 10 -2  mM. Collectively, these important stability findings open possibilities for applications involving a wide pH and temperature ranges.

Biological effects of tritium on fish cells in the concentration range of international drinking water standards.

PubMed

Stuart, Marilyne; Festarini, Amy; Schleicher, Krista; Tan, Elizabeth; Kim, Sang Bog; Wen, Kendall; Gawlik, Jilian; Ulsh, Brant

2016-10-01

To evaluate whether the current Canadian tritium drinking water limit is protective of aquatic biota, an in vitro study was designed to assess the biological effects of low concentrations of tritium, similar to what would typically be found near a Canadian nuclear power station, and higher concentrations spanning the range of international tritium drinking water standards. Channel catfish peripheral blood B-lymphoblast and fathead minnow testis cells were exposed to 10-100,000 Bq l(-1) of tritium, after which eight molecular and cellular endpoints were assessed. Increased numbers of DNA strand breaks were observed and ATP levels were increased. There were no increases in γH2AX-mediated DNA repair. No differences in cell growth were noted. Exposure to the lowest concentrations of tritium were associated with a modest increase in the viability of fathead minnow testicular cells. Using the micronucleus assay, an adaptive response was observed in catfish B-lymphoblasts. Using molecular endpoints, biological responses to tritium in the range of Canadian and international drinking water standards were observed. At the cellular level, no detrimental effects were noted on growth or cycling, and protective effects were observed as an increase in cell viability and an induced resistance to a large challenge dose.

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.

Field Demonstrations of Active Laser Ranging with Sub-mm Precision

NASA Technical Reports Server (NTRS)

Chen, Yijiang; Birnbaum, Kevin M.; Hemmati, Hamid

2011-01-01

Precision ranging between planets will provide valuable information for scientific studies of the solar system and fundamental physics. Current passive ranging techniques using retro-reflectors are limited to the Earth-Moon distance due to the 1/R? losses. We report on a laboratory realization and field implementation of active laser ranging in real-time with two terminals, emulating interplanetary distance. Sub-millimeter accuracy is demonstrated.

Concentration and temperature effects on ovostatin activity

NASA Technical Reports Server (NTRS)

Moriarity, Debra M.

1994-01-01

Light scattering experiments performed at Mississippi State University using MSFC ovostatin preparations indicated that at low ovostatin concentrations, below 0.2 mg/ml, the protein was dissociating from a tetramer into dimers. Since the proposed mechanism of action involved the tetrameric form of the protein, we hypothesized that perhaps under the conditions of our assays at various O/T ratios the ovostatin was becoming dissociated into an inactive dimer. To examine this possibility we assayed the ovostatin activity as a function of ovostatin concentration and of temperature of the assay. Data are presented that show the results of these assays at 23 C, 30 C, 37 C and 42 C respectively. The data are highly suggestive that there is a decrease in ovostatin activity as the concentration of the protein falls below 0.06 mg/ml. This may not be of any physiological importance, however, since the concentration of ovostatin in the egg is about 0.5 mg/ml. Curiously, the dissociation of the tetramer into dimers does not show a significant temperature dependence as would be expected for an equilibrium reaction. Whether this is in fact the case, or whether the differences are so small as to not be discerned from the current data remains to be seen. Another aspect to consider is that in the egg the primary role of the ovostatin may or may not be as a protease inhibitor. Although the inhibition of collagenase by ovostatin may be an important aspect of embryogenesis, it is also possible that it functions as a binding protein for some substance. In this regard, all ovostatin preparations from MSFC have shown an approximately 88,000 MW protein associated with the ovostatin. The identity of this protein is not currently known and may be the subject of future studies.

Analytical study of 226Ra activity concentration in market consuming foodstuffs of Ramsar, Iran.

PubMed

Gooniband Shooshtari, M; Deevband, M R; Kardan, M R; Fathabadi, N; Salehi, A A; Naddafi, K; Yunesian, M; Nabizadeh Nodehi, R; Karimi, M; Hosseini, S S

2017-01-01

Ramsar, a city of Iran located on the coast of the Caspian Sea, has been considered to be enormously important due to its high natural radioactivity levels. People living in High Level Natural Radiation Areas (HLNRAs) have been exposed by several sources, one of which could be foodstuff. However, many studies have been carried out to measure the environmental radioactivity in Ramsar, but no survey has been conducted in all stapled consumed foods yet. This study was dedicated to determine 226 Ra activity concentration in the daily diets of Ramsar residents as a probable exposure. Approximately 70 different market samples were collected during the four seasons based on the daily consumption patterns of residents which have the highest consumption and their availability in the seasons. All samples, after washing, drying and pretreatment, were analyzed for 226 Ra radionuclide determination by α-spectrometry. The mean radioactivity concentration of 226 Ra ranged between 7 ± 1 mBq Kg -1 wet weight in meat, and 318 ± 118 mBq Kg -1 for tea dry leaves. The 226 Ra activity concentrations in collected samples varied from below the minimum detectable activity up to 530 ± 30 mBq Kg -1 . To compare the results with United Nations Scientific Committee on Effects of Atomic Radiation (UNSCEAR) reference values, the 226 Ra activity concentrations concluded from the results appear to be higher in milk, chicken and eggs and less in grain products, vegetables, fruits and fish products. These results indicate that no significant 226 Ra contamination is present in market foodstuffs and provide reference values for the foodstuffs in Ramsar. Of the total daily dietary 226 Ra exposure from market consuming foodstuffs for adults in Ramsar, the largest percentage was from wheat. The residents consuming wheat and manufacturing wheat products such as bread, pasta, porridge, crackers, biscuits, pancakes, pies, pastries, cakes, cookies, muffins, rolls, doughnuts, breakfast cereals and

Middle-Range Theory: Coping and Adaptation with Active Aging.

PubMed

Salazar-Barajas, Martha Elba; Salazar-González, Bertha Cecilia; Gallegos-Cabriales, Esther Carlota

2017-10-01

Various disciplines focus on a multiplicity of aspects of aging: lifestyles, personal biological factors, psychological conditions, health conditions, physical environment, and social and economic factors. The aforementioned are all related to the determinants of active aging. The aim is to describe the development of a middle-range theory based on coping and adaptation with active aging. Concepts and relationships derived from Roy's model of adaptation are included. The proposed concepts are hope, health habits, coping with aging, social relations, and active aging.

Strontium-90 activity concentration in soil samples from the exclusion zone of the Fukushima daiichi nuclear power plant

NASA Astrophysics Data System (ADS)

Sahoo, Sarata Kumar; Kavasi, Norbert; Sorimachi, Atsuyuki; Arae, Hideki; Tokonami, Shinji; Mietelski, Jerzy Wojciech; Łokas, Edyta; Yoshida, Satoshi

2016-04-01

The radioactive fission product 90Sr has a long biological half-life (˜18 y) in the human body. Due to its chemical similarity to calcium it accumulates in bones and irradiates the bone marrow, causing its high radio-toxicity. Assessing 90Sr is therefore extremely important in case of a nuclear disaster. In this work 16 soil samples were collected from the exclusion zone (<30 km) of the earthquake-damaged Fukushima Daiichi nuclear power plant, to measure 90Sr activity concentration using liquid scintillation counting. 137Cs activity concentration was also measured with gamma-spectroscopy in order to investigate correlation with 90Sr. The 90Sr activity concentrations ranged from 3.0 ± 0.3 to 23.3 ± 1.5 Bq kg-1 while the 137Cs from 0.7 ± 0.1 to 110.8 ± 0.3 kBq kg-1. The fact that radioactive contamination originated from the Fukushima nuclear accident was obvious due to the presence of 134Cs. However, 90Sr contamination was not confirmed in all samples although detectable amounts of 90Sr can be expected in Japanese soils, as a background, stemming from global fallout due to the atmospheric nuclear weapon tests. Correlation analysis between 90Sr and 137Cs activity concentrations provides a potentially powerful tool to discriminate background 90Sr level from its Fukushima contribution.

Strontium-90 activity concentration in soil samples from the exclusion zone of the Fukushima daiichi nuclear power plant.

PubMed

Sahoo, Sarata Kumar; Kavasi, Norbert; Sorimachi, Atsuyuki; Arae, Hideki; Tokonami, Shinji; Mietelski, Jerzy Wojciech; Łokas, Edyta; Yoshida, Satoshi

2016-04-06

The radioactive fission product (90)Sr has a long biological half-life (˜18 y) in the human body. Due to its chemical similarity to calcium it accumulates in bones and irradiates the bone marrow, causing its high radio-toxicity. Assessing (90)Sr is therefore extremely important in case of a nuclear disaster. In this work 16 soil samples were collected from the exclusion zone (<30 km) of the earthquake-damaged Fukushima Daiichi nuclear power plant, to measure (90)Sr activity concentration using liquid scintillation counting. (137)Cs activity concentration was also measured with gamma-spectroscopy in order to investigate correlation with (90)Sr. The (90)Sr activity concentrations ranged from 3.0 ± 0.3 to 23.3 ± 1.5 Bq kg(-1) while the (137)Cs from 0.7 ± 0.1 to 110.8 ± 0.3 kBq kg(-1). The fact that radioactive contamination originated from the Fukushima nuclear accident was obvious due to the presence of (134)Cs. However, (90)Sr contamination was not confirmed in all samples although detectable amounts of (90)Sr can be expected in Japanese soils, as a background, stemming from global fallout due to the atmospheric nuclear weapon tests. Correlation analysis between (90)Sr and (137)Cs activity concentrations provides a potentially powerful tool to discriminate background (90)Sr level from its Fukushima contribution.

Strontium-90 activity concentration in soil samples from the exclusion zone of the Fukushima daiichi nuclear power plant

PubMed Central

Sahoo, Sarata Kumar; Kavasi, Norbert; Sorimachi, Atsuyuki; Arae, Hideki; Tokonami, Shinji; Mietelski, Jerzy Wojciech; Łokas, Edyta; Yoshida, Satoshi

2016-01-01

The radioactive fission product 90Sr has a long biological half-life (˜18 y) in the human body. Due to its chemical similarity to calcium it accumulates in bones and irradiates the bone marrow, causing its high radio-toxicity. Assessing 90Sr is therefore extremely important in case of a nuclear disaster. In this work 16 soil samples were collected from the exclusion zone (<30 km) of the earthquake-damaged Fukushima Daiichi nuclear power plant, to measure 90Sr activity concentration using liquid scintillation counting. 137Cs activity concentration was also measured with gamma-spectroscopy in order to investigate correlation with 90Sr. The 90Sr activity concentrations ranged from 3.0 ± 0.3 to 23.3 ± 1.5 Bq kg−1 while the 137Cs from 0.7 ± 0.1 to 110.8 ± 0.3 kBq kg−1. The fact that radioactive contamination originated from the Fukushima nuclear accident was obvious due to the presence of 134Cs. However, 90Sr contamination was not confirmed in all samples although detectable amounts of 90Sr can be expected in Japanese soils, as a background, stemming from global fallout due to the atmospheric nuclear weapon tests. Correlation analysis between 90Sr and 137Cs activity concentrations provides a potentially powerful tool to discriminate background 90Sr level from its Fukushima contribution. PMID:27048779

Distribution of microbial arsenic reduction, oxidation and extrusion genes along a wide range of environmental arsenic concentrations.

PubMed

Escudero, Lorena V; Casamayor, Emilio O; Chong, Guillermo; Pedrós-Alió, Carles; Demergasso, Cecilia

2013-01-01

The presence of the arsenic oxidation, reduction, and extrusion genes arsC, arrA, aioA, and acr3 was explored in a range of natural environments in northern Chile, with arsenic concentrations spanning six orders of magnitude. A combination of primers from the literature and newly designed primers were used to explore the presence of the arsC gene, coding for the reduction of As (V) to As (III) in one of the most common detoxification mechanisms. Enterobacterial related arsC genes appeared only in the environments with the lowest As concentration, while Firmicutes-like genes were present throughout the range of As concentrations. The arrA gene, involved in anaerobic respiration using As (V) as electron acceptor, was found in all the systems studied. The As (III) oxidation gene aioA and the As (III) transport gene acr3 were tracked with two primer sets each and they were also found to be spread through the As concentration gradient. Sediment samples had a higher number of arsenic related genes than water samples. Considering the results of the bacterial community composition available for these samples, the higher microbial phylogenetic diversity of microbes inhabiting the sediments may explain the increased number of genetic resources found to cope with arsenic. Overall, the environmental distribution of arsenic related genes suggests that the occurrence of different ArsC families provides different degrees of protection against arsenic as previously described in laboratory strains, and that the glutaredoxin (Grx)-linked arsenate reductases related to Enterobacteria do not confer enough arsenic resistance to live above certain levels of As concentrations.

Concentration evolution of pharmaceutically active compounds in raw urban and industrial wastewater.

PubMed

Camacho-Muñoz, Dolores; Martín, Julia; Santos, Juan Luis; Aparicio, Irene; Alonso, Esteban

2014-09-01

The distribution of pharmaceutically active compounds in the environment has been reported in several works in which wastewater treatment plants have been identified as the main source of these compounds to the environment. The concentrations of these compounds in influent wastewater can vary widely not only during the day but also along the year, because of the seasonal-consumption patterns of some pharmaceuticals. However, only few studies have attempted to assess the hourly variability of the concentrations of pharmaceutically active compounds in wastewater. In this work, the distribution and seasonal and hourly variability of twenty-one pharmaceuticals, belonging to seven therapeutic groups, have been investigated in urban and industrial wastewater. The highest concentrations of pharmaceutically active compounds, except salicylic acid, were found in urban wastewater, especially in the case of anti-inflammatory drugs and caffeine. The highest concentrations of salicylic acid were measured in industrial wastewater, reaching concentration levels up to 3295μgL(-)(1). The studied pharmaceutically active compounds showed different distribution patterns during winter and summer periods. Temporal variability of pharmaceutically active compounds during a 24-h period showed a distribution in concordance with their consumption and excretion patterns, in the case of urban wastewater, and with the schedule of industrial activities, in the case of industrial wastewater. Copyright © 2014 Elsevier Ltd. All rights reserved.

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

USGS Publications Warehouse

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

1998-01-01

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

Intramuscular pressure and torque during isometric, concentric and eccentric muscular activity

NASA Technical Reports Server (NTRS)

Styf, J.; Ballard, R.; Aratow, M.; Crenshaw, A.; Watenpaugh, D.; Hargens, A. R.

1995-01-01

Intramuscular pressures, electromyography (EMG) and torque generation during isometric, concentric and eccentric maximal isokinetic muscle activity were recorded in 10 healthy volunteers. Pressure and EMG activity were continuously and simultaneously measured side by side in the tibialis anterior and soleus muscles. Ankle joint torque and position were monitored continuously by an isokinetic dynamometer during plantar flexion and dorsiflexion of the foot. The increased force generation during eccentric muscular activity, compared with other muscular activity, was not accompanied by higher intramuscular pressure. Thus, this study demonstrated that eccentric muscular activity generated higher torque values for each increment of intramuscular pressure. Intramuscular pressures during antagonistic co-activation were significantly higher in the tibilis anterior muscle (42-46% of maximal agonistic activity) compared with the soleus muscle (12-29% of maximal agonistic activity) and was largely due to active recruitment of muscle fibers. In summary, eccentric muscular activity creates higher torque values with no additional increase of the intramuscular pressure compared with concentric and isometric muscular activity.

Active thermal fine laser tuning in a broad spectral range and optical properties of cholesteric liquid crystal.

PubMed

Jeong, Mi-Yun; Kwak, Keumcheol

2016-11-20

In this study, we achieved active fine laser tuning in a broad spectral range with dye-doped cholesteric liquid crystal wedge-type cells through temperature control. The spatial pitch gradient of each position of the wedge cell at room temperature was almost maintained after developing a temperature gradient. To achieve the maximum tuning range, the chiral dopant concentration, thickness, thickness gradient, and temperature gradient on the wedge cell should be matched properly. In order to understand the laser tuning mechanism for temperature change, we studied the temperature dependence of optical properties of the photonic bandgap of cholesteric liquid crystals. In our cholesteric liquid crystal samples, when temperature was increased, photonic bandgaps were shifted toward blue, while the width of the photonic bandgap was decreased, regardless of whether the helicity was left-handed or right-handed. This is mainly due to the combination of decreased refractive indices, higher molecular anisotropy of chiral molecules, and increased chiral molecular solubility. We envisage that this kind of study will prove useful in the development of practical active tunable CLC laser devices.

137Cs activity concentration in mosses in the Calabria region, south of Italy

NASA Astrophysics Data System (ADS)

Caridi, F.; Belvedere, A.; D'Agostino, M.; Marguccio, S.

2017-05-01

Many studies carried out after the Chernobyl nuclear accident in 1986 showed that mosses are suitable bioindicators of the radioactive fall-out, given their long life expectancy. 137Cs activity concentration was measured through HPGe gamma spectrometry in different mosses (Hypnum Cupressiforme, Hypnum Andoi, Homalothecium Sericeum, Philonotis Fontana), collected, in 2008 and 2015, from four sampling sites in the Calabria region, south of Italy. Experimental specific activities allowed us to determine the effective and the biological half-time of 137Cs for the investigated plants. The effective half-time was found in the range from (4.2 ± 1.1) to (7.4 ± 1.8) years; the biological half-time varied from (4.9 ± 1.3) to (9.9 ± 2.4) years. Data reported in this article provide useful information on the environmental risk of the studied area and can be further used for a radiological mapping.

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

Overcoming non-specific binding to measure the active concentration and kinetics of serum anti-HLA antibodies by surface plasmon resonance.

PubMed

Visentin, Jonathan; Couzi, Lionel; Dromer, Claire; Neau-Cransac, Martine; Guidicelli, Gwendaline; Veniard, Vincent; Coniat, Karine Nubret-le; Merville, Pierre; Di Primo, Carmelo; Taupin, Jean-Luc

2018-06-07

Human leukocyte antigen (HLA) donor-specific antibodies are key serum biomarkers for assessing the outcome of transplanted patients. Measuring their active concentration, i.e. the fraction that really interacts with donor HLA, and their affinity could help deciphering their pathogenicity. Surface plasmon resonance (SPR) is recognized as the gold-standard for measuring binding kinetics but also active concentrations, without calibration curves. SPR-based biosensors often suffer from non-specific binding (NSB) occurring with the sensor chip surface and the immobilized targets, especially for complex media such as human serum. In this work we show that several serum treatments such as dialysis or IgG purification reduce NSB but insufficiently for SPR applications. We then demonstrate that the NSB contribution to the SPR signal can be eliminated to determine precisely and reliably the active concentration and the affinity of anti-HLA antibodies from patients' sera. This was achieved even at concentrations close to the limit of quantification of the method, in the 0.5-1 nM range. The robustness of the assay was demonstrated by using a wide range of artificially generated NSB and by varying the density of the targets captured onto the surface. The assay is of general interest and can be used with molecules generating strong NSB, as far as a non-cognate target structurally close to the target can be captured on the same flow cell, in a different binding cycle. Compared with current fluorescence-based methods that are semi-quantitative, we expect this SPR-based assay to help better understanding anti-HLA antibodies pathogenicity and improving organ recipients' management. Copyright © 2018 Elsevier B.V. All rights reserved.

Effect of supplementing different concentrations of organic trace minerals on performance, antioxidant activity, and bone mineralization in Vanaraja chickens developed for free range farming.

PubMed

Rao, Savaram Venkata Rama; Prakash, Bhukya; Kumari, Kanya; Raju, Mantena Venkata Laxmi Narasimha; Panda, Arun Kumar

2013-08-01

An experiment was conducted to determine the performance, antioxidation activity, and bone mineral content in Vanaraja chickens fed diet supplemented with organic trace minerals (oTM) at reduced levels. A total of 360 day-old chicks were selected and distributed randomly into 60 battery brooder pens. A maize-soybean meal-based control diet was supplemented with inorganic trace minerals (iTM), i.e., Mn, Zn, Fe, and Cu at 50, 45, 40, and 7.5 mg/kg, respectively, and varying concentration of oTM, i.e., Zn, Mn, Cu, Fe, I, Se, and Cr at 45, 50, 7.5, 40, 2, 0.30, and 0.25 mg/kg (diet II); 33.75, 37.50, 5.63, 30.0, 1.50, 0.23, and 0.19 mg/kg (diet III); 22.5, 25.0, 3.75, 20.0, 1.0, 0.15, and 0.13 mg/kg (diet IV); 18.0, 20.0, 3.0, 16.0, 0.80, 0.12, and 0.10 mg/kg (diet V); and 13.5, 15.0, 2.25, 12.0, 0.60, 0.09, and 0.08 mg/kg (diet VI), respectively. Each diet was allotted randomly to ten replicates and fed ad libitum from 1 to 42 days of age. The body weight at 14, 28, and 42 days was not affected by reducing the supplementation of oTM concentration in the diets. Similarly, feed intake at 14 days of age was not affected but reduced significantly (P < 0.05) in the group fed diet IV (50% oTM) compared to that in the other groups. The higher feed conversion ratio and increased concentration of Ca, P, and trace minerals in tibia were evident in the group fed oTM-supplemented diets compared to the diet containing iTM. Activities of glutathione peroxidase and ferric reducing ability in plasma did not differ in the groups fed on lower concentration of oTM compared to those fed on diet I (control diet). Therefore, it is concluded that the dietary supplementation of trace minerals can be reduced greatly when supplemented as organic form without affecting growth and antioxidant status in Vanaraja chickens.

Prominent facilitation at beta and gamma frequency range revealed with physiological calcium concentration in adult mouse piriform cortex in vitro

PubMed Central

Gleizes, Marie; Perrier, Simon P.; Fonta, Caroline

2017-01-01

Neuronal activity is characterized by a diversity of oscillatory phenomena that are associated with multiple behavioral and cognitive processes, yet the functional consequences of these oscillations are not fully understood. Our aim was to determine whether and how these different oscillatory activities affect short-term synaptic plasticity (STP), using the olfactory system as a model. In response to odorant stimuli, the olfactory bulb displays a slow breathing rhythm as well as beta and gamma oscillations. Since the firing of olfactory bulb projecting neurons is phase-locked with beta and gamma oscillations, structures downstream from the olfactory bulb should be driven preferentially at these frequencies. We examined STP exhibited by olfactory bulb inputs in slices of adult mouse piriform cortex maintained in vitro in an in vivo-like ACSF (calcium concentration: 1.1 mM). We replaced the presynaptic neuronal firing rate by repeated electrical stimulation (frequency between 3.125 and 100 Hz) applied to the lateral olfactory tract. Our results revealed a considerable enhancement of postsynaptic response amplitude for stimulation frequencies in the beta and gamma range. A phenomenological model of STP fitted to the data suggests that the experimental results can be explained by the interplay between three mechanisms: a short-term facilitation mechanism (time constant ≈160 msec), and two short-term depression mechanisms (recovery time constants <20 msec and ≈140 msec). Increasing calcium concentration (2.2 mM) resulted in an increase in the time constant of facilitation and in a strengthening of the slowest depression mechanism. As a result, response enhancement was reduced and its peak shifted toward the low beta and alpha ranges while depression became predominant in the gamma band. Using environmental conditions corresponding to those that prevail in vivo, our study shows that STP in the lateral olfactory tract to layer Ia synapse allows amplification of

Activity concentrations of ²²⁶Ra, ²³²Th and ⁴⁰K in brands of fertilisers used in Nigeria.

PubMed

Jibiri, N N; Fasae, K P

2012-01-01

The activity concentration of naturally occurring radionuclides ⁴⁰K, ²²⁶Ra and ²³²Th have been measured in different brands of fertiliser samples sold to farmers in retail markets in six commercial cities in southwestern Nigeria. Gamma ray spectroscopy was employed in the measurements of these radionuclides. The results of measurements showed that the average activity concentration of ⁴⁰K in the nitrogen, phosphorus and potassium fertilisers across the cities varied from 3972.0 ± 416.9 to 5089.3 ± 111.3 Bq kg⁻¹, 9.9 ± 7.3 to 450.6 ± 14.3 Bq kg⁻¹ for ²²⁶Ra, while for ²³²Th it varied from less than lower limit of detection to 15.1 ± 2.8 Bq kg⁻¹. The activity concentrations of ⁴⁰K, ²²⁶Ra and ²³²Th in single super phosphate (SSP) fertilisers and phosphate rocks were also determined. However, high activity concentrations of ²²⁶Ra were obtained in the SSP fertiliser and phosphate rocks and in particular, two brands of fertilisers from ITL/TAK and F & C companies. The values of the activity concentration of the radionuclides in the brands of fertilisers used in Nigeria are within the range of values reported in several other countries except ⁴⁰K.

Critical Concentration of Lecithin Enhances the Antimicrobial Activity of Eugenol against Escherichia coli.

PubMed

Zhang, Haoshu; Dudley, Edward G; Davidson, P Michael; Harte, Federico

2017-04-15

Lecithin is a natural emulsifier used in a wide range of food and nonfood applications to improve physical stability, with no known bioactive effects. In this study, the effect of lecithin on the antimicrobial performance of a constant eugenol concentration was tested against three Escherichia coli strains (C600, 0.1229, and O157:H7 strain ATCC 700728). This is the first study, to our knowledge, focusing on lecithin at concentrations below those commonly used in foods to improve the stability of oil in water emulsions (≤10 mg/100 ml). For all three cultures, significant synergistic antimicrobial effects were observed when E. coli cultures were exposed to a constant eugenol concentration (ranging from 0.043 to 0.050% [wt/wt]) together with critical lecithin concentrations ranging from 0.5 to 1 mg/100 ml. Increasing the concentration of lecithin above 1 mg/100 ml (up to 10 mg/100 ml lecithin) diminished the antibacterial effect to values similar to those with eugenol-only treatments. The formation of aggregates (<100 nm) at the critical lecithin concentration was observed using cryo-transmission electron microscopy (cryo-TEM), together with a reduction in light absorbance at 284 nm. At critically low concentrations of lecithin, the formation of nanoscale aggregates is responsible for improving eugenol antimicrobial effects. IMPORTANCE Essential oils (EOs) are effective natural antimicrobials. However, their hydrophobicity and strong aromatic character limit the use of essential oils in food systems. Emulsifiers (e.g., lecithin) increase the stability of EOs in water-based systems but fail to consistently improve antimicrobial effects. We demonstrate that lecithin, within a narrow critical concentration window, can enhance the antimicrobial properties of eugenol. This study highlights the potential bioactivity of lecithin when utilized to effectively control foodborne pathogens. Copyright © 2017 American Society for Microbiology.

Critical Concentration of Lecithin Enhances the Antimicrobial Activity of Eugenol against Escherichia coli

PubMed Central

Zhang, Haoshu; Dudley, Edward G.; Davidson, P. Michael

2017-01-01

ABSTRACT Lecithin is a natural emulsifier used in a wide range of food and nonfood applications to improve physical stability, with no known bioactive effects. In this study, the effect of lecithin on the antimicrobial performance of a constant eugenol concentration was tested against three Escherichia coli strains (C600, 0.1229, and O157:H7 strain ATCC 700728). This is the first study, to our knowledge, focusing on lecithin at concentrations below those commonly used in foods to improve the stability of oil in water emulsions (≤10 mg/100 ml). For all three cultures, significant synergistic antimicrobial effects were observed when E. coli cultures were exposed to a constant eugenol concentration (ranging from 0.043 to 0.050% [wt/wt]) together with critical lecithin concentrations ranging from 0.5 to 1 mg/100 ml. Increasing the concentration of lecithin above 1 mg/100 ml (up to 10 mg/100 ml lecithin) diminished the antibacterial effect to values similar to those with eugenol-only treatments. The formation of aggregates (<100 nm) at the critical lecithin concentration was observed using cryo-transmission electron microscopy (cryo-TEM), together with a reduction in light absorbance at 284 nm. At critically low concentrations of lecithin, the formation of nanoscale aggregates is responsible for improving eugenol antimicrobial effects. IMPORTANCE Essential oils (EOs) are effective natural antimicrobials. However, their hydrophobicity and strong aromatic character limit the use of essential oils in food systems. Emulsifiers (e.g., lecithin) increase the stability of EOs in water-based systems but fail to consistently improve antimicrobial effects. We demonstrate that lecithin, within a narrow critical concentration window, can enhance the antimicrobial properties of eugenol. This study highlights the potential bioactivity of lecithin when utilized to effectively control foodborne pathogens. PMID:28213539

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

USGS Publications Warehouse

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

1983-01-01

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

Characteristics of Zinc Phosphate Coating Activated by Different Concentrations of Nickel Acetate Solution

NASA Astrophysics Data System (ADS)

Abdalla, Khalid; Zuhailawati, H.; Rahmat, Azmi; Azizan, A.

2017-02-01

Activation pretreatment with nickel acetate solution at various concentrations was performed prior to the phosphating step to enhance the corrosion resistance of carbon steel substrates. The activation solution was studied over various concentrations: 10, 50, and 100 g/L. The effects of these concentrations on surface characteristics and microstructural evolution of the coated samples were characterized by scanning electron microscopy and energy-dispersive spectroscopy. The electrochemical behavior was evaluated using potentiodynamic polarization curves, electrochemical impedance spectroscopy, and immersion test in a 3.5 pct NaCl solution. Significant increases in the nucleation sites and surface coverage of zinc phosphate coating were observed as the concentration of activation solution reached 50 g/L. The electrochemical analysis revealed that the activation treatment with 50 g/L nickel acetate solution significantly improved the protection ability of the zinc phosphate coating. The corrosion current density of activated phosphate coating with 50 g/L was reduced by 64.64 and 13.22 pct, compared to the coatings obtained with activation solutions of 10 and 100 g/L, respectively.

Photovoltaic concentrator assembly with optically active cover

DOEpatents

Plesniak, Adam P

2014-01-21

A photovoltaic concentrator assembly that includes a housing that defines an internal volume and includes a rim, wherein the rim defines an opening into the internal volume, a photovoltaic cell positioned in the internal volume, and an optical element that includes an optically active body and a flange extending outward from the body, wherein the flange is sealingly engaged with the rim of the housing to enclose the internal volume.

Freezing-Out Technique Applied to the Concentration of Biologically Active Materials

PubMed Central

Wilson, T. E.; Evans, D. J.; Theriot, Mary L.

1964-01-01

When applied to a dilute solution of folic acid and glucose, a freezing-out (with agitation) technique was shown to be an effective method of achieving a 20-fold reduction in volume with a loss of 10% of the active material being concentrated. Concentration of a stimulatory factor for Lactobacillus casei produced by Candida albicans in a complex medium was limited by the total solute concentration. Salts in the medium were concentrated to levels inhibitory for L. casei. The process is not selective and all solutes are concentrated. Images FIG. 2 FIG. 3 PMID:14131370

Range of therapeutic metformin concentrations in clinical blood samples and comparison to a forensic case with death due to lactic acidosis.

PubMed

Hess, C; Unger, M; Madea, B; Stratmann, B; Tschoepe, D

2018-05-01

Due to a lack of reference values for blood concentration of metformin in the literature, the forensic evaluation of metformin findings in blood samples is difficult. Interpretations with regard to the assessment of blood concentrations as well as an estimation of the ingested metformin amounts are often vague. Furthermore, post mortem evaluation of death due to lactic acidosis because of metformin is difficult since renal performance or lactate concentrations can not always reliably be determined after death. To describe a concentration range in clinical samples after chronic use of metformin, metformin serum concentrations were determined in serum samples of 95 diabetic patients receiving daily doses of 500mg-3000mg of metformin. The analyses of metformin was carried out using a validated high performance liquid chromatograph coupled to triple quadrupole mass spectrometry (LC-QQQ-MS). On average, metformin concentrations were 1846ng/mL (concentration and glomerular filtration rate except for the 1700mg daily dose collective (R 2 =0.707). Results of the herein presented study are useful for the interpretation of analytical metformin findings in forensic toxicology. The utility of the described concentration range is demonstrated by discussing a death case involving a fatal lactate acidosis after metformin intake and renal failure. Usefulness of the parameters metformin blood concentration, lactate concentration and glomerular filtration rate in post mortem cases of lactic acidosis due to metformin intoxication are discussed. Copyright © 2018 Elsevier B.V. All rights reserved.

H2O activity in concentrated NaCl solutions at high pressures and temperatures measured by the brucite-periclase equilibrium

NASA Astrophysics Data System (ADS)

Aranovich, L. Y.; Newton, R. C.

1996-10-01

H2O activities in concentrated NaCl solutions were measured in the ranges 600° 900° C and 2 15 kbar and at NaCl concentrations up to halite saturation by depression of the brucite (Mg(OH)2) periclase (MgO) dehydration equilibrium. Experiments were made in internally heated Ar pressure apparatus at 2 and 4.2 kbar and in 1.91-cm-diameter piston-cylinder apparatus with NaCl pressure medium at 4.2, 7, 10 and 15 kbar. Fluid compositions in equilibrium with brucite and periclase were reversed to closures of less than 2 mol% by measuring weight changes after drying of punctured Pt capsules. Brucite-periclase equilibrium in the binary system was redetermined using coarsely crystalline synthetic brucite and periclase to inhibit back-reaction in quenching. These data lead to a linear expression for the standard Gibbs free energy of the brucite dehydration reaction in the experimental temperature range: ΔG° (±120J)=73418 134.95 T(K). Using this function as a baseline, the experimental dehydration points in the system MgO-H2O-NaCl lead to a simple systematic relationship of high-temperature H2O activity in NaCl solution. At low pressure and low fluid densities near 2 kbar the H2O activity is closely approximated by its mole fraction. At pressures of 10 kbar and greater, with fluid densities approaching those of condensed H2O, the H2O activity becomes nearly equal to the square of its mole fraction. Isobaric halite saturation points terminating the univariant brucite-periclase curves were determined at each experimental pressure. The five temperature-composition points in the system NaCl-H2O are in close agreement with the halite saturation curves (liquidus curves) given by existing data from differential thermal analysis to 6 kbar. Solubility of MgO in the vapor phase near halite saturation is much less than one mole percent and could not have influenced our determinations. Activity concentration relations in the experimental P-T range may be retrieved for the binary

Relationship between leptin concentrations and disease activity in patients with rheumatoid arthritis.

PubMed

Batún-Garrido, José Antonio de Jesús; Salas-Magaña, Marisol; Juárez-Rojop, Isela Esther; Hernández-Núñez, Eúfrates; Olán, Francisco

2018-05-11

Multiple studies have found a direct relationship between leptin concentrations and disease activity in rheumatoid arthritis. We studied 77 patients with the diagnosis of rheumatoid arthritis; the leptin determination was through an enzyme immunoassay. Disease activity was assessed by the DAS-28 CRP. A multivariate logistic regression model was used to determine the association between significant variables and leptin concentrations. 40.3% of the patients were in remission, 41.6% were mildly active, 11.7% were moderately active and 6.5% were severely active. The results show an independent association between higher concentrations of leptin and disease activity (OR 1.7; 95% CI 1.4-3.2; p .03), the number of swollen joints (OR 4.6; 95% CI 1.7-8.3; p .000), the number of painful joints (OR 3.4; 95% CI 1.6-4.6; p .000), and the presence of metabolic syndrome (OR 1.3; 95% IC 1.2-1,9; p .045). The data suggest that serum leptin is elevated in patients with active RA. Copyright © 2017 Elsevier España, S.L.U. All rights reserved.

How incense and joss paper burning during the worship activities influences ambient mercury concentrations in indoor and outdoor environments of an Asian temple?

PubMed

Shen, Huazhen; Tsai, Cheng-Mou; Yuan, Chung-Shin; Jen, Yi-Hsiu; Ie, Iau-Ren

2017-01-01

This study firstly investigated the species, concentration variation, and emission factors of mercury emitted from the burning of incenses and joss papers in an Asian temple. Both indoor and outdoor speciated mercury (GEM, GOM, and PHg) were sampled by manual samplers, while ambient GEM at an indoor site was in-situ monitored by a continuous GEM monitor. Field measurement results showed that the total atmospheric mercury (TAM) concentrations in indoor and outdoor environments were in the range of 8.03-35.72 and 6.03-31.35 ng/m 3 , respectively. The indoor and outdoor ratios (I/O) of TAM in the daytime and at nighttime were in the range of 0.64-0.90 and 1.50-2.04, respectively. The concentrations of GEM, GOM, and PHg during the holiday periods were approximately 1-4 times higher than those during the non-holiday periods. GEM was the dominant mercury species in the indoor and outdoor environments and accounted for 63-81% of TAM, while the oxidized mercury accounted for 19-37% of TAM. Burning incenses and joss papers in a combustion chamber showed that the concentration of GEM from joss paper burning ranged from 4.07 to 11.62 μg/m 3 , or about 13.97 times higher than that of incense burning, while the concentration of PHg from incense burning ranged from 95.91 to 135.07 ng/m 3 , or about 3.29 times higher than that of joss paper burning. The emission factors of incense burning were 10.39 ng/g of GEM and 1.40 ng/g of PHg, while those of joss paper burning were 12.65 ng/g of GEM and 1.27 ng/g of PHg, respectively. This study revealed that speciated mercury emitted from worship activities had significant influence on the indoor and outdoor mercury concentrations in an Asian temple. Higher intensity of worship activities during holidays resulted in a higher concentration of speciated mercury in indoor and outdoor air, which might cause health threats to worshipers, staffs, and surrounding inhabitants through long-term exposure. Copyright © 2016 Elsevier Ltd. All

Keeping their distance? Odor response patterns along the concentration range

PubMed Central

Strauch, Martin; Ditzen, Mathias; Galizia, C. Giovanni

2012-01-01

We investigate the interplay of odor identity and concentration coding in the antennal lobe (AL) of the honeybee Apis mellifera. In this primary olfactory center of the honeybee brain, odors are encoded by the spatio-temporal response patterns of olfactory glomeruli. With rising odor concentration, further glomerular responses are recruited into the patterns, which affects distances between the patterns. Based on calcium-imaging recordings, we found that such pattern broadening renders distances between glomerular response patterns closer to chemical distances between the corresponding odor molecules. Our results offer an explanation for the honeybee's improved odor discrimination performance at higher odor concentrations. PMID:23087621

Sea Ice Concentration Estimation Using Active and Passive Remote Sensing Data Fusion

NASA Astrophysics Data System (ADS)

Zhang, Y.; Li, F.; Zhang, S.; Zhu, T.

2017-12-01

In this abstract, a decision-level fusion method by utilizing SAR and passive microwave remote sensing data for sea ice concentration estimation is investigated. Sea ice concentration product from passive microwave concentration retrieval methods has large uncertainty within thin ice zone. Passive microwave data including SSM/I, AMSR-E, and AMSR-2 provide daily and long time series observations covering whole polar sea ice scene, and SAR images provide rich sea ice details with high spatial resolution including deformation and polarimetric features. In the proposed method, the merits from passive microwave data and SAR data are considered. Sea ice concentration products from ASI and sea ice category label derived from CRF framework in SAR imagery are calibrated under least distance protocol. For SAR imagery, incident angle and azimuth angle were used to correct backscattering values from slant range to ground range in order to improve geocoding accuracy. The posterior probability distribution between category label from SAR imagery and passive microwave sea ice concentration product is modeled and integrated under Bayesian network, where Gaussian statistical distribution from ASI sea ice concentration products serves as the prior term, which represented as an uncertainty of sea ice concentration. Empirical model based likelihood term is constructed under Bernoulli theory, which meets the non-negative and monotonically increasing conditions. In the posterior probability estimation procedure, final sea ice concentration is obtained using MAP criterion, which equals to minimize the cost function and it can be calculated with nonlinear iteration method. The proposed algorithm is tested on multiple satellite SAR data sets including GF-3, Sentinel-1A, RADARSAT-2 and Envisat ASAR. Results show that the proposed algorithm can improve the accuracy of ASI sea ice concentration products and reduce the uncertainty along the ice edge.

Effects of Low Phytanic Acid-Concentrated DHA on Activated Microglial Cells: Comparison with a Standard Phytanic Acid-Concentrated DHA.

PubMed

Ruiz-Roso, María Belén; Olivares-Álvaro, Elena; Quintela, José Carlos; Ballesteros, Sandra; Espinosa-Parrilla, Juan F; Ruiz-Roso, Baltasar; Lahera, Vicente; de Las Heras, Natalia; Martín-Fernández, Beatriz

2018-05-30

Docosahexaenoic acid (DHA, 22:6 n-3) is an essential omega-3 (ω-3) long chain polyunsaturated fatty acid of neuronal membranes involved in normal growth, development, and function. DHA has been proposed to reduce deleterious effects in neurodegenerative processes. Even though, some inconsistencies in findings from clinical and pre-clinical studies with DHA could be attributed to the presence of phytanic acid (PhA) in standard DHA treatments. Thus, the aim of our study was to analyze and compare the effects of a low PhA-concentrated DHA with a standard PhA-concentrated DHA under different neurotoxic conditions in BV-2 activated microglial cells. To this end, mouse microglial BV-2 cells were stimulated with either lipopolysaccharide (LPS) or hydrogen peroxide (H 2 O 2 ) and co-incubated with DHA 50 ppm of PhA (DHA (PhA:50)) or DHA 500 ppm of PhA (DHA (PhA:500)). Cell viability, superoxide anion (O 2 - ) production, Interleukin 6 (L-6), cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS), glutathione peroxidase (GtPx), glutathione reductase (GtRd), Caspase-3, and the brain-derived neurotrophic factor (BDNF) protein expression were explored. Low PhA-concentrated DHA protected against LPS or H 2 O 2 -induced cell viability reduction in BV-2 activated cells and O 2 - production reduction compared to DHA (PhA:500). Low PhA-concentrated DHA also decreased COX-2, IL-6, iNOS, GtPx, GtRd, and SOD-1 protein expression when compared to DHA (PhA:500). Furthermore, low PhA-concentrated DHA increased BDNF protein expression in comparison to DHA (PhA:500). The study provides data supporting the beneficial effect of low PhA-concentrated DHA in neurotoxic injury when compared to a standard PhA-concentrated DHA in activated microglia.

Network feedback regulates motor output across a range of modulatory neuron activity

PubMed Central

Spencer, Robert M.

2016-01-01

Modulatory projection neurons alter network neuron synaptic and intrinsic properties to elicit multiple different outputs. Sensory and other inputs elicit a range of modulatory neuron activity that is further shaped by network feedback, yet little is known regarding how the impact of network feedback on modulatory neurons regulates network output across a physiological range of modulatory neuron activity. Identified network neurons, a fully described connectome, and a well-characterized, identified modulatory projection neuron enabled us to address this issue in the crab (Cancer borealis) stomatogastric nervous system. The modulatory neuron modulatory commissural neuron 1 (MCN1) activates and modulates two networks that generate rhythms via different cellular mechanisms and at distinct frequencies. MCN1 is activated at rates of 5–35 Hz in vivo and in vitro. Additionally, network feedback elicits MCN1 activity time-locked to motor activity. We asked how network activation, rhythm speed, and neuron activity levels are regulated by the presence or absence of network feedback across a physiological range of MCN1 activity rates. There were both similarities and differences in responses of the two networks to MCN1 activity. Many parameters in both networks were sensitive to network feedback effects on MCN1 activity. However, for most parameters, MCN1 activity rate did not determine the extent to which network output was altered by the addition of network feedback. These data demonstrate that the influence of network feedback on modulatory neuron activity is an important determinant of network output and feedback can be effective in shaping network output regardless of the extent of network modulation. PMID:27030739

Network feedback regulates motor output across a range of modulatory neuron activity.

PubMed

Spencer, Robert M; Blitz, Dawn M

2016-06-01

Modulatory projection neurons alter network neuron synaptic and intrinsic properties to elicit multiple different outputs. Sensory and other inputs elicit a range of modulatory neuron activity that is further shaped by network feedback, yet little is known regarding how the impact of network feedback on modulatory neurons regulates network output across a physiological range of modulatory neuron activity. Identified network neurons, a fully described connectome, and a well-characterized, identified modulatory projection neuron enabled us to address this issue in the crab (Cancer borealis) stomatogastric nervous system. The modulatory neuron modulatory commissural neuron 1 (MCN1) activates and modulates two networks that generate rhythms via different cellular mechanisms and at distinct frequencies. MCN1 is activated at rates of 5-35 Hz in vivo and in vitro. Additionally, network feedback elicits MCN1 activity time-locked to motor activity. We asked how network activation, rhythm speed, and neuron activity levels are regulated by the presence or absence of network feedback across a physiological range of MCN1 activity rates. There were both similarities and differences in responses of the two networks to MCN1 activity. Many parameters in both networks were sensitive to network feedback effects on MCN1 activity. However, for most parameters, MCN1 activity rate did not determine the extent to which network output was altered by the addition of network feedback. These data demonstrate that the influence of network feedback on modulatory neuron activity is an important determinant of network output and feedback can be effective in shaping network output regardless of the extent of network modulation. Copyright © 2016 the American Physiological Society.

Airborne Measurements of CO2 Column Concentration and Range Using a Pulsed Direct-Detection IPDA Lidar

NASA Technical Reports Server (NTRS)

Abshire, James B.; Ramanathan, Anand; Riris, Haris; Mao, Jianping; Allan, Graham R.; Hasselbrack, William E.; Weaver, Clark J.; Browell, Edward V.

2013-01-01

We have previously demonstrated a pulsed direct detection IPDA lidar to measure range and the column concentration of atmospheric CO2. The lidar measures the atmospheric backscatter profiles and samples the shape of the 1,572.33 nm CO2 absorption line. We participated in the ASCENDS science flights on the NASA DC-8 aircraft during August 2011 and report here lidar measurements made on four flights over a variety of surface and cloud conditions near the US. These included over a stratus cloud deck over the Pacific Ocean, to a dry lake bed surrounded by mountains in Nevada, to a desert area with a coal-fired power plant, and from the Rocky Mountains to Iowa, with segments with both cumulus and cirrus clouds. Most flights were to altitudes >12 km and had 5-6 altitude steps. Analyses show the retrievals of lidar range, CO2 column absorption, and CO2 mixing ratio worked well when measuring over topography with rapidly changing height and reflectivity, through thin clouds, between cumulus clouds, and to stratus cloud tops. The retrievals shows the decrease in column CO2 due to growing vegetation when flying over Iowa cropland as well as a sudden increase in CO2 concentration near a coal-fired power plant. For regions where the CO2 concentration was relatively constant, the measured CO2 absorption lineshape (averaged for 50 s) matched the predicted shapes to better than 1% RMS error. For 10 s averaging, the scatter in the retrievals was typically 2-3 ppm and was limited by the received signal photon count. Retrievals were made using atmospheric parameters from both an atmospheric model and from in situ temperature and pressure from the aircraft. The retrievals had no free parameters and did not use empirical adjustments, and >70% of the measurements passed screening and were used in analysis. The differences between the lidar-measured retrievals and in situ measured average CO2 column concentrations were <1.4 ppm for flight measurement altitudes >6 km.

Correlation of endothelin-1 concentration and angiotensin-converting enzyme activity with the staging of liver fibrosis.

PubMed

Kardum, Dusko; Fabijanić, Damir; Lukić, Anita; Romić, Zeljko; Petrovecki, Mladen; Bogdanović, Zoran; Jurić, Klara; Urek-Crncević, Marija; Banić, Marko

2012-06-01

Increased serum angiotensin-converting enzyme (SACE) activity and serum concentration of endothelin-1 (ET-1) were found in liver cirrhosis. We investigated a correlation between the different stages of liver fibrosis and SACE activity and serum ET-1 concentration. Seventy patients with pathohistologically established chronic liver disease were divided in three groups according to Ishak criteria for liver fibrosis: minimal fibrosis (Ishak score 0-1, n =20), medium fibrosis (Ishak score 2-5, n=20) and cirrhosis (Ishak score 6, n=30). SACE activity and ET-1 concentration were determined using commercial ELISA kits. SACE activity and ET-1 concentrations were proportional to the severity of disease, the highest being in patients with liver cirrhosis. Maximal increase in SACE activity was found between minimal and medium fibrosis while maximal increase in ET-1 concentration was revealed between medium fibrosis and cirrhosis. The analysis of the Receiver Operating Characteristic (ROC) curve for SACE activity suggested a cut-off value to separate minimal from medium fibrosis at 59.00 U/L (sensitivity 100%, specificity 64.7%). The cut-off value for serum ET-1 concentration to separate medium fibrosis from cirrhosis was 12.4 pg/mL (sensitivity 96.8%, specificity 94.4%). A positive correlation between SACE activity and ET-1 concentration was registered (Spearman's ñ = 0.438, p = 0.004). Both SACE activity and ET-1 concentration were increased in all stages of liver fibrosis. Cut-off points for SACE activity and ET-1 concentration could be a biochemical marker for the progression of fibrosis. Positive correlation between SACE activity and ET-1 concentration might indicate their interaction in the development of liver cirrhosis.

Bactericidal activity of electrolyzed acid water from solution containing sodium chloride at low concentration, in comparison with that at high concentration.

PubMed

Kiura, Hiromasa; Sano, Kouichi; Morimatsu, Shinichi; Nakano, Takashi; Morita, Chizuko; Yamaguchi, Masaki; Maeda, Toyoyuki; Katsuoka, Yoji

2002-05-01

Electrolyzed strong acid water (ESW) containing free chlorine at various concentrations is becoming to be available in clinical settings as a disinfectant. ESW is prepared by electrolysis of a NaCl solution, and has a corrosive activity against medical instruments. Although lower concentrations of NaCl and free chlorine are desired to eliminate corrosion, the germicidal effect of ESW with low NaCl and free-chlorine concentrations (ESW-L) has not been fully clarified. In this study, we demonstrated that ESW-L possesses bactericidal activity against Mycobacteria and spores of Bacillus subtilis. The effect was slightly weaker than that of ESW containing higher NaCl and free-chlorine concentrations (ESW-H), but acceptable as a disinfectant. To clarify the mechanism of the bactericidal activity, we investigated ESW-L-treated Pseudomonas aeruginosa by transmission electron microscopy, a bacterial enzyme assay and restriction fragment length polymorphism pattern (RFLP) assay. Since the bacterium, whose growth was completely inhibited by ESW-L, revealed the inactivation of cytoplasmic enzyme, blebs and breaks in its outer membrane and remained complete RFLP of DNA, damage of the outer membrane and inactivation of cytoplasmic enzyme are the important determinants of the bactericidal activity.

Interaction between Trypanosoma rangeli and the Rhodnius prolixus salivary gland depends on the phosphotyrosine ecto-phosphatase activity of the parasite.

PubMed

Dos-Santos, André L A; Dick, Claudia F; Alves-Bezerra, Michele; Silveira, Thaís S; Paes, Lisvane Silva; Gondim, Katia C; Meyer-Fernandes, José R

2012-08-01

Trypanosoma rangeli is the trypanosomatid that colonizes the salivary gland of its insect vector, with a profound impact on the feeding capacity of the insect. In this study we investigated the role of the phosphotyrosine (P-Tyr) ecto-phosphatase activity of T. rangeli in its interaction with Rhodnius prolixus salivary glands. Long but not short epimastigotes adhered to the gland cells and the strength of interaction correlated with the enzyme activity levels in different strains. Differential interference contrast microscopy demonstrated that clusters of parasites are formed in most cases, suggesting cooperative interaction in the adhesion process. The tightness of the correlation was evidenced by modulating the P-Tyr ecto-phosphatase activity with various concentrations of inhibitors. Sodium orthovanadate, ammonium molybdate and zinc chloride decreased the interaction between T. rangeli and R. prolixus salivary glands in parallel. Levamisole, an inhibitor of alkaline phosphatases, affected neither process. EDTA strongly inhibited adhesion and P-Tyr ecto-phosphatase activity to the same extent, an effect that was no longer seen if the parasites were pre-incubated with the chelator and then washed. When the P-Tyr ecto-phosphatase of living T. rangeli epimastigotes was irreversibly inactivated with sodium orthovanadate and the parasite cells were then injected into the insect thorax, colonization of the salivary glands was greatly depressed for several days after blood feeding. Addition of P-Tyr ecto-phosphatase substrates such as p-nitrophenyl phosphate (pNPP) and P-Tyr inhibited the adhesion of T. rangeli to salivary glands, but P-Ser, P-Thr and β-glycerophosphate were completely ineffective. Immunoassays using anti-P-Tyr-residues revealed a large number of P-Tyr-proteins in extracts of R. prolixus salivary glands, which could be potentially targeted by T. rangeli during adhesion. These results indicate that dephosphorylation of structural P-Tyr residues on the

Erbium concentration anomaly as an indicator of nuclear activity: Focus on Natural waters in the Chernobyl exclusion zone.

PubMed

Plausinaitis, Deivis; Prokopchik, Aleksandr; Karaliunas, Algimantas; Bohdan, Leonid; Balashevska, Yuliya

2018-04-15

This study focused on measurement of lanthanides in surface water (SW) and ground water (GW) samples from the Chernobyl Exclusion Zone. Results showed that the total lanthanide concentration in SW ranges from 500 to 1100ngL -1 and is about 10 times lower than the GW concentration. The normalized patterns of lanthanide concentrations increase from lighter elements to heavier lanthanides. Concurrently, concentration anomalies of Ce, Eu, and Er are visible. The Er anomaly is the most noticeable and exceeds the theoretical calculation by about 13 times. The Ce and Eu anomalies are likely related to the variety of oxidation states of these elements. Meanwhile, the cause of the Er anomaly is not completely clear, but is likely related to the Chernobyl Nuclear Power Plant accident, since increased concentrations correlate with the distribution of contamination in the zone. 137 Cs activity measurements partially confirm this hypothesis. Simultaneously, there is a relationship between the positive Er anomaly and increase in 235 U concentrations. However, there is no reliable information in the literature that indicates that Er was used in the Chernobyl Nuclear Power Plant before the reactor accident. Copyright © 2017 Elsevier B.V. All rights reserved.

Contributions of long-range and regional atmospheric transport on pesticide concentrations along a transect crossing a mountain divide.

PubMed

Lavin, Karen S; Hageman, Kimberly J

2013-02-05

Twenty-one halogenated legacy and current-use pesticides and pesticide degradation products were measured in pine needles along a coast-to-coast transect that crossed the Southern Alps of New Zealand. Concentration profiles of nine pesticides were used to determine the influence of geographic sources on the atmospheric pesticide burden at the mountain sites. Pesticide concentration profiles were calculated for each source and mountain site by normalizing concentrations (adjusted for temperature at the site and air-needle partitioning) to the sum of all pesticide concentrations at the site. Each mountain site profile was compared to varying mixtures of the potential source profiles to determine the percent contribution of each source. The highest elevation mountain sites were primarily influenced by long-range, synoptic-scale northwesterly winds. Westerly upslope winds had little influence on any of the mountain sites. Easterly upslope winds from the Canterbury Plains, an agricultural region, strongly influenced the mountain sites within close proximity and had progressively less influence with distance.

[Non vascularized toe phalangeal transfers for symbrachydactyly. Active range of motion without joint reconstruction].

PubMed

Leca, J-B; Auquit Auckbur, I; Bachy, B; Milliez, P-Y

2008-12-01

Symbrachydactyly is a rare congenital malformation of the hand and its treatment is controversial. Non vascularized toe phalangeal transfers have been used for management of short digits for three children. Six phalanges have been harvested complete with their periosteum. No joint reconstruction has been performed and all children have undergone surgery at a young age. Four of six digits involved have an active range of motion (range 30 to 105 degrees ). All authors who have reported active range of motion of toe phalangeal transfers have performed joint reconstruction. Here, we report obtaining active range of motion of phalangeal transfers without necessity of joint reconstruction.

Habitat influence on antioxidant activity and tannin concentrations of Spondias tuberosa.

PubMed

de Sousa Araújo, Thiago Antônio; de Almeida e Castro, Valerium Thijan Nobre; de Amorim, Elba Lúcia Cavalcanti; de Albuquerque, Ulysses Paulino

2012-06-01

Different habitat conditions can be responsible for the production of secondary metabolites and for the antioxidant properties of plant products. Thus, the aim of this study was to evaluate whether the antioxidant activity and tannin concentrations in the stem bark of Spondias tuberosa Arruda (Anacardiaceae) varied with collection site. The bark was collected from 25 individual trees, distributed in five different landscape units, as follows: agroforestry gardens, areas of pastures, maize cultivation areas, mountain areas and mountain bases, with the former 3 being considered as anthropogenic habitats, and the latter 2 considered as habitats with native coverage. The study was conducted in the rural area of the city of Altinho, Pernambuco State (Northeast Brazil). The DPPH (1,1-diphenyl-2-picrylhydrazyl) method was used to measure the antioxidant activity and tannin concentrations were evaluated by using the radial diffusion method. The results demonstrated that there were no significant differences among the tannin concentrations of the individuals from the native (6.27% ± 1.75) or anthropogenic areas (4.63% ± 2.55), (H = 2.24; p > 0.05). In contrast, there were significant differences (H = 5.1723; p < 0.05) among the CE₅₀ means of the antioxidant activities of the individuals from the native (32.10 µg/ml ± 5.27) and anthropogenic areas (27.07 µg/ml ± 2.29). However, correlations between the tannin concentrations and antioxidant activity of the extracts were not observed in the native (r = 0.39; p > 0.05) or in the anthropogenic areas (r = 0.38; p > 0.05). Because the variation of the antioxidant capacity of S. tuberosa bark was not accompanied by a variation in the tannin concentration, this property may be related to the presence of other metabolite(s).

Fabrication Processes to Generate Concentration Gradients in Polymer Solar Cell Active Layers

PubMed Central

Inaba, Shusei; Vohra, Varun

2017-01-01

Polymer solar cells (PSCs) are considered as one of the most promising low-cost alternatives for renewable energy production with devices now reaching power conversion efficiencies (PCEs) above the milestone value of 10%. These enhanced performances were achieved by developing new electron-donor (ED) and electron-acceptor (EA) materials as well as finding the adequate morphologies in either bulk heterojunction or sequentially deposited active layers. In particular, producing adequate vertical concentration gradients with higher concentrations of ED and EA close to the anode and cathode, respectively, results in an improved charge collection and consequently higher photovoltaic parameters such as the fill factor. In this review, we relate processes to generate active layers with ED–EA vertical concentration gradients. After summarizing the formation of such concentration gradients in single layer active layers through processes such as annealing or additives, we will verify that sequential deposition of multilayered active layers can be an efficient approach to remarkably increase the fill factor and PCE of PSCs. In fact, applying this challenging approach to fabricate inverted architecture PSCs has the potential to generate low-cost, high efficiency and stable devices, which may revolutionize worldwide energy demand and/or help develop next generation devices such as semi-transparent photovoltaic windows. PMID:28772878

Fabrication Processes to Generate Concentration Gradients in Polymer Solar Cell Active Layers.

PubMed

Inaba, Shusei; Vohra, Varun

2017-05-09

Polymer solar cells (PSCs) are considered as one of the most promising low-cost alternatives for renewable energy production with devices now reaching power conversion efficiencies (PCEs) above the milestone value of 10%. These enhanced performances were achieved by developing new electron-donor (ED) and electron-acceptor (EA) materials as well as finding the adequate morphologies in either bulk heterojunction or sequentially deposited active layers. In particular, producing adequate vertical concentration gradients with higher concentrations of ED and EA close to the anode and cathode, respectively, results in an improved charge collection and consequently higher photovoltaic parameters such as the fill factor. In this review, we relate processes to generate active layers with ED-EA vertical concentration gradients. After summarizing the formation of such concentration gradients in single layer active layers through processes such as annealing or additives, we will verify that sequential deposition of multilayered active layers can be an efficient approach to remarkably increase the fill factor and PCE of PSCs. In fact, applying this challenging approach to fabricate inverted architecture PSCs has the potential to generate low-cost, high efficiency and stable devices, which may revolutionize worldwide energy demand and/or help develop next generation devices such as semi-transparent photovoltaic windows.

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.

Diurnal variations of radon and thoron activity concentrations and effective doses in dwellings in Niška Banja, Serbia.

PubMed

Vaupotič, J; Streil, T; Tokonami, S; Žunic, Z S

2013-12-01

In Niška Banja, a spa town in a radon-prone area in southern Serbia, radon ((222)Rn) and thoron ((220)Rn) activity concentrations were measured continuously for one day in indoor air of 10 dwellings with a SARAD RTM 2010-2 Radon/Thoron Monitor, and equilibrium factor between radon and its decay products and the fraction of unattached radon decay products with a SARAD EQF 3020-2 Equilibrium Factor Monitor. Radon concentration in winter time ranged from 26 to 73 100 Bq m(-3) and that of thoron, from 10 to 8650 Bq m(-3). In the same period, equilibrium factor and the unattached fraction varied in the range of 0.08 to 0.90 and 0.01 to 0.27, respectively. One-day effective doses were calculated and were in winter conditions from 4 to 2599 μSv d(-1) for radon and from 0.2 to 73 μSv d(-1) for thoron.

[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.

Baseline reference range for trace metal concentrations in whole blood of wild and managed West Indian Manatees (Trichechus manatus) in Florida and Belize

USGS Publications Warehouse

Takeuchi, Noel Y.; Walsh, Michael T; Bonde, Robert K.; Powell, James A.; Bass, Dean A.; Gaspard, Joseph C.; Barber, David S.

2016-01-01

The West Indian manatee (Trichechus manatus) is exposed to a number of anthropogenic influences, including metals, as they inhabit shallow waters with close proximity to shore. While maintaining homeostasis of many metals is crucial for health, there is currently no baseline reference range that can be used to make clinical and environmental decisions for this endangered species. In this study, whole blood samples from 151 manatees were collected during health assessments performed in Florida and Belize from 2008 through 2011. Whole blood samples (n = 37) from managed care facilities in Florida and Belize from 2009 through 2011 were also used in this study. The concentrations of 17 metals in whole blood were determined, and the data were used to derive a baseline reference range. Impacts of capture location, age, and sex on whole blood metal concentrations were examined. Location and age were related to copper concentrations as values were significantly higher in habitats near urban areas and in calves. Copper may also be a husbandry concern as concentrations were significantly higher in managed manatees (1.17 ± 0.04 ppm) than wild manatees (0.73 ± 0.02 ppm). Zinc (11.20 ± 0.30 ppm) was of special interest as normal concentrations were two to five times higher than other marine mammal species. Arsenic concentrations were higher in Belize (0.43 ± 0.07 ppm), with Placencia Lagoon having twice the concentration of Belize City and Southern Lagoon. Selenium concentrations were lower (0.18 ± 0.09 ppm) than in other marine mammal species. The lowest selenium concentrations were observed in rehabilitating and managed manatees which may warrant additional monitoring in managed care facilities. The established preliminary baseline reference range can be used by clinicians, biologists, and managers to monitor the health of West Indian manatees.

Long-range Transported African Dust in the Caribbean Region: Dust Concentrations and Water-soluble Ions

NASA Astrophysics Data System (ADS)

Santos-Figueroa, G.; Avilés-Piñeiro, G. M.; Mayol-Bracero, O. L.

2017-12-01

Long-range transported African dust (LRTAD) particles reach the Caribbean region every year during the summer months causing an increase in PM10 concentrations and by consequence degradation of air quality. During African dust (AD) incursions at the Caribbean region, PM10 concentration could exceeds the exposure limit of 50 µg/m³ 24-hour mean established by the World Health Organization (WHO). To have a better understanding of the impacts of AD particles to climate and public health at the Caribbean region it is necessary to study and determine the spatial and temporal distribution of dust particles. In order to address this, aerosols samples were collected during and absence of AD incursions during the summer of 2017 using a Hi-Volume (Hi-Vol) sampler for total suspended particles (TSP) at two sampling stations in Puerto Rico. The first station is a marine site located at Cabezas de San Juan (CSJ) Nature Reserve in Fajardo, and the second station is an urban site located at the Facundo Bueso (FB) building at the University of Puerto Rico-Rio Piedras. Aerosol samples were collected using Whatman 41 grade filters from which we determined the concentration of dust particles and the water-soluble ions (e.g., Na+, NH4+, Ca+2, Cl-, SO4-2) in the presence and absence of LRTAD particles. Saharan Air Layer (SAL) imagery, the results from the air mass backward trajectories calculated with the NOAA Hybrid Single Particle Lagrangian Integrated Trajectory Model (HYSPLIT), and the spectral coefficients from measurements at CSJ were used to monitor and confirm the presence of air masses coming from North Africa. Average dust concentrations using the Stacked-Filter Units (SFUs) at CSJ are around 4 μg/m3. LRTAD concentrations and ionic speciation results using the Hi-Vol for the marine and urban sites will be presented at the conference.

Natural Radionuclide Activity Concentrations In Spas Of Argentina

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

Gnoni, G.; Czerniczyniec, M.; Canoba, A.

2008-08-07

Geothermal waters have been used on a large scale for bathing, drinking and medical purposes. These waters can contain natural radionuclides that may increase the exposure to people. In this work the most important natural radionuclide activity concentrations in different thermal spas of Argentina were measured to characterize waters and to evaluate the exposure of workers and members of the public.

The thermodynamic characteristics of solutions of Bu4NI in dimethylsulfoxide over a wide concentration range

NASA Astrophysics Data System (ADS)

Safonova, L. P.; Shmukler, L. E.; Kolker, A. M.

2008-05-01

The integral heats of solution of Bu4NI in dimethylsulfoxide (DMSO) were measured at 298.15, 313.15, and 328.15 K and concentrations from dilute to saturation. The standard enthalpies and heat capacities of solution and solvation of Bu4NI in DMSO at various temperatures and the bar C_p^o (Bu_4 N^ + ) value at 298.15 K were calculated. The obtained and literature data were used to consider the influence of the nature of solvents on Δsol H m (Bu4NI) and of the electrolyte on Δsol H m in dimethylsulfoxide at 298.15 K. The dynamic viscosity and density of the Bu4NI-DMSO system were determined at various concentrations and temperatures. The Eyring equation was used to calculate the activation energy of viscous flow at all the concentrations studied.

Large-scale production and properties of human plasma-derived activated Factor VII concentrate.

PubMed

Tomokiyo, K; Yano, H; Imamura, M; Nakano, Y; Nakagaki, T; Ogata, Y; Terano, T; Miyamoto, S; Funatsu, A

2003-01-01

An activated Factor VII (FVIIa) concentrate, prepared from human plasma on a large scale, has to date not been available for clinical use for haemophiliacs with antibodies against FVIII and FIX. In the present study, we attempted to establish a large-scale manufacturing process to obtain plasma-derived FVIIa concentrate with high recovery and safety, and to characterize its biochemical and biological properties. FVII was purified from human cryoprecipitate-poor plasma, by a combination of anion exchange and immunoaffinity chromatography, using Ca2+-dependent anti-FVII monoclonal antibody. To activate FVII, a FVII preparation that was nanofiltered using a Bemberg Microporous Membrane-15 nm was partially converted to FVIIa by autoactivation on an anion-exchange resin. The residual FVII in the FVII and FVIIa mixture was completely activated by further incubating the mixture in the presence of Ca2+ for 18 h at 10 degrees C, without any additional activators. For preparation of the FVIIa concentrate, after dialysis of FVIIa against 20 mm citrate, pH 6.9, containing 13 mm glycine and 240 mm NaCl, the FVIIa preparation was supplemented with 2.5% human albumin (which was first pasteurized at 60 degrees C for 10 h) and lyophilized in vials. To inactivate viruses contaminating the FVIIa concentrate, the lyophilized product was further heated at 65 degrees C for 96 h in a water bath. Total recovery of FVII from 15 000 l of plasma was approximately 40%, and the FVII preparation was fully converted to FVIIa with trace amounts of degraded products (FVIIabeta and FVIIagamma). The specific activity of the FVIIa was approximately 40 U/ micro g. Furthermore, virus-spiking tests demonstrated that immunoaffinity chromatography, nanofiltration and dry-heating effectively removed and inactivated the spiked viruses in the FVIIa. These results indicated that the FVIIa concentrate had both high specific activity and safety. We established a large-scale manufacturing process of human plasma

Relationship among Phosphorus Circulation Activity, Bacterial Biomass, pH, and Mineral Concentration in Agricultural Soil.

PubMed

Adhikari, Dinesh; Jiang, Tianyi; Kawagoe, Taiki; Kai, Takamitsu; Kubota, Kenzo; Araki, Kiwako S; Kubo, Motoki

2017-12-04

Improvement of phosphorus circulation in the soil is necessary to enhance phosphorus availability to plants. Phosphorus circulation activity is an index of soil's ability to supply soluble phosphorus from organic phosphorus in the soil solution. To understand the relationship among phosphorus circulation activity; bacterial biomass; pH; and Fe, Al, and Ca concentrations (described as mineral concentration in this paper) in agricultural soil, 232 soil samples from various agricultural fields were collected and analyzed. A weak relationship between phosphorus circulation activity and bacterial biomass was observed in all soil samples ( R ² = 0.25), and this relationship became significantly stronger at near-neutral pH (6.0-7.3; R ² = 0.67). No relationship between phosphorus circulation activity and bacterial biomass was observed at acidic (pH < 6.0) or alkaline (pH > 7.3) pH. A negative correlation between Fe and Al concentrations and phosphorus circulation activity was observed at acidic pH ( R ² = 0.72 and 0.73, respectively), as well as for Ca at alkaline pH ( R ² = 0.64). Therefore, bacterial biomass, pH, and mineral concentration should be considered together for activation of phosphorus circulation activity in the soil. A relationship model was proposed based on the effects of bacterial biomass and mineral concentration on phosphorus circulation activity. The suitable conditions of bacterial biomass, pH, and mineral concentration for phosphorus circulation activity could be estimated from the relationship model.

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

PubMed

Nardelli, Schuyler C; Twardowski, Michael S

2016-10-31

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

PCB concentrations and activity of sea lamprey Petromyzon marinus vary by sex

USGS Publications Warehouse

Madenjian, Charles P.; Johnson, Nicholas S.; Binder, Thomas R.; Rediske, Richard R.; O'Keefe, James P.

2013-01-01

We determined the polychlorinated biphenyl (PCB) concentrations of 40 male and 40 female adult sea lampreys Petromyzon marinus captured in the Cheboygan River, a tributary to Lake Huron, during May 2011. In addition, we performed a laboratory experiment using passive integrated transponder tags to determine whether male adult sea lampreys were more active than female adult sea lampreys. Sex had a significant effect on PCB concentration, and PCB concentration at a given level of sea lamprey condition was approximately 25 % greater in males than in females. Adjusting for the difference in condition between the sexes, males averaged a 17 % greater PCB concentration compared with females. Results from the laboratory experiment indicated that males were significantly more active than females. The observed sex difference in PCB concentrations was not due to female sea lampreys releasing eggs at spawning because the sea lamprey is semelparous, and we caught the sea lampreys before spawning. Rather, we attributed the sex difference in PCB concentrations to a greater rate of energy expenditure in males compared with females. We proposed that this greater rate of energy expenditure was likely due to greater activity. Our laboratory experiment results supported this hypothesis. A greater resting metabolic rate may also have contributed to a greater rate of energy expenditure. Our findings should eventually be applicable toward improving control of sea lamprey, a pest responsible for considerable damage to fisheries in lakes where it is not native.

Amorphous In-Ga-Zn-O Powder with High Gas Selectivity towards Wide Range Concentration of C₂H₅OH.

PubMed

Chen, Hongxiang; Jiang, Wei; Zhu, Lianfeng; Yao, Youwei

2017-05-24

Amorphous indium gallium zinc oxide (a-IGZO) powder was prepared by typical solution-based process and post-annealing process. The sample was used as sensor for detecting C₂H₅OH, H₂, and CO. Gas-sensing performance was found to be highly sensitive to C₂H₅OH gas in a wide range of concentration (0.5-1250 ppm) with the response of 2.0 towards 0.5 ppm and 89.2 towards 1250 ppm. Obvious difference of response towards C₂H₅OH, H₂, and CO was found that the response e.g., was 33.20, 6.64, and 2.84 respectively at the concentration of 200 ppm. The response time and recovery time of was 32 s and 14 s respectively towards 200 ppm concentration of C₂H₅OH gas under heating voltage of 6.5 V.

Dense-array concentrator photovoltaic system using non-imaging dish concentrator and crossed compound parabolic concentrator

NASA Astrophysics Data System (ADS)

Chong, Kok-Keong; Yew, Tiong-Keat; Wong, Chee-Woon; Tan, Ming-Hui; Tan, Woei-Chong; Lai, An-Chow; Lim, Boon-Han; Lau, Sing-Liong; Rahman, Faidz Abdul

2015-04-01

Solar concentrating device plays an important role by making use of optical technology in the design, which can be either reflector or lens to deliver high flux of sunlight onto the Concentrator Photovoltaic (CPV) module receiver ranging from hundreds to thousand suns. To be more competitive compared with fossil fuel, the current CPV systems using Fresnel lens and Parabolic dish as solar concentrator that are widely deployed in United States, Australia and Europe are facing great challenge to produce uniformly focused sunlight on the solar cells as to reduce the cost of electrical power generation. The concept of non-imaging optics is not new, but it has not fully explored by the researchers over the world especially in solving the problem of high concentration solar energy, which application is only limited to be a secondary focusing device or low concentration device using Compound Parabolic Concentrator. With the current advancement in the computer processing power, we has successfully invented the non-imaging dish concentrator (NIDC) using numerical simulation method to replace the current parabolic dish as primary focusing device with high solar concentration ratio (more than 400 suns) and large collective area (from 25 to 125 m2). In this paper, we disclose our research and development on dense array CPV system based on non-imaging optics. The geometry of the NIDC is determined using a special computational method. In addition, an array of secondary concentrators, namely crossed compound parabolic concentrators, is also proposed to further focus the concentrated sunlight by the NIDC onto active area of solar cells of the concentrator photovoltaic receiver. The invention maximizes the absorption of concentrated sunlight for the electric power generation system.

Impact of short range hydrophobic interactions and long range electrostatic forces on the aggregation kinetics of a monoclonal antibody and a dual-variable domain immunoglobulin at low and high concentrations.

PubMed

Kumar, Vineet; Dixit, Nitin; Zhou, Liqiang Lisa; Fraunhofer, Wolfgang

2011-12-12

The purpose of this work was to determine the nature of long and short-range forces governing protein aggregation kinetics at low and high concentrations for a monoclonal antibody (IgG1) and a dual-variable-domain immunoglobulin (DVD-Ig). Protein-protein interactions (PPI) were studied under dilute conditions by utilizing the methods of static (B(22)) and dynamic light scattering (k(D)). PPI in solutions containing minimal ionic strengths were characterized to get detailed insights into the impact of ionic strength on aggregation. Microcalorimetry and susceptibility to denature at air-liquid interface were used to assess the tertiary structure and quiescent stability studies were conducted to study aggregation characteristics. Results for IgG1 showed that electrostatic interactions governed protein aggregation kinetics both under dilute and concentrated conditions (i.e., 5 mg/mL and 150 mg/mL). For DVD-Ig molecules, on the other hand, although electrostatic interactions governed protein aggregation under dilute conditions, hydrophobic forces clearly determined the kinetics at high concentrations. This manuscript shows for the first time that short-range hydrophobic interactions can outweigh electrostatic forces and play an important role in determining protein aggregation at high concentrations. Additionally, results show that although higher-order virial coefficients become significant under low ionic strength conditions, removal of added charges may be used to enhance the aggregation stability of dilute protein formulations. Copyright © 2011 Elsevier B.V. All rights reserved.

Competitive adsorption between benzene and ethylene dichloride on activated carbon: The importance of concentration

NASA Astrophysics Data System (ADS)

Miao, T.; Tang, H. M.; Cheng, Z. X.

2018-03-01

In this work we studied breakthroughs of binary mixtures of benzene and ethylene dichloride on fixed activated carbons bed. The results show a series of assault concentrations on activated carbon bed influences the nature of the adsorption competition mechanism. Assault concentration were used to determine how competition of compound distribution. The results are discussed in terms of competing energetic and the underlying molecular mechanisms. The ratio of assault concentrations is main reason for determining selectivity.

Preparation of factor VII concentrate using CNBr-activated Sepharose 4B immunoaffinity chromatography

PubMed Central

Mousavi Hosseini, Kamran; Nasiri, Saleh

2015-01-01

Background: Factor VII concentrates are used in patients with congenital or acquired factor VII deficiency or treatment of hemophilia patients with inhibitors. In this research, immunoaffinity chromatography was used to purify factor VII from prothrombin complex (Prothrombin- Proconvertin-Stuart Factor-Antihemophilic Factor B or PPSB) which contains coagulation factors II, VII, IX and X. The aim of this study was to improve purity, safety and tolerability as a highly purified factor VII concentrate. Methods: PPSB was prepared using DEAE-Sephadex and was used as the starting material for purification of coagulation factor VII. Prothrombin complex was treated by solvent/detergent at 24°C for 6 h with constant stirring. The mixture of PPSB in the PBS buffer was filtered and then chromatographed using CNBr-activated Sepharose 4B coupled with specific antibody. Factors II, IX, VII, X and VIIa were assayed on the fractions. Fractions of 48-50 were pooled and lyophilized as a factor VII concentrate. Agarose gel electrophoresis was performed and Tween 80 was measured in the factor VII concentrate. Results: Specific activity of factor VII concentrate increased from 0.16 to 55.6 with a purificationfold of 347.5 and the amount of activated factor VII (FVIIa) was found higher than PPSB (4.4-fold). Results of electrophoresis on agarose gel indicated higher purity of Factor VII compared to PPSB; these finding revealed that factor VII migrated as alpha-2 proteins. In order to improve viral safety, solvent-detergent treatment was applied prior to further purification and nearly complete elimination of tween 80 (2 μg/ml). Conclusion: It was concluded that immuonoaffinity chromatography using CNBr-activated Sepharose 4B can be a suitable choice for large-scale production of factor VII concentrate with higher purity, safety and activated factor VII. PMID:26034723

Preparation of factor VII concentrate using CNBr-activated Sepharose 4B immunoaffinity chromatography.

PubMed

Mousavi Hosseini, Kamran; Nasiri, Saleh

2015-01-01

Factor VII concentrates are used in patients with congenital or acquired factor VII deficiency or treatment of hemophilia patients with inhibitors. In this research, immunoaffinity chromatography was used to purify factor VII from prothrombin complex (Prothrombin- Proconvertin-Stuart Factor-Antihemophilic Factor B or PPSB) which contains coagulation factors II, VII, IX and X. The aim of this study was to improve purity, safety and tolerability as a highly purified factor VII concentrate. PPSB was prepared using DEAE-Sephadex and was used as the starting material for purification of coagulation factor VII. Prothrombin complex was treated by solvent/detergent at 24°C for 6 h with constant stirring. The mixture of PPSB in the PBS buffer was filtered and then chromatographed using CNBr-activated Sepharose 4B coupled with specific antibody. Factors II, IX, VII, X and VIIa were assayed on the fractions. Fractions of 48-50 were pooled and lyophilized as a factor VII concentrate. Agarose gel electrophoresis was performed and Tween 80 was measured in the factor VII concentrate. Specific activity of factor VII concentrate increased from 0.16 to 55.6 with a purificationfold of 347.5 and the amount of activated factor VII (FVIIa) was found higher than PPSB (4.4-fold). RESULTS of electrophoresis on agarose gel indicated higher purity of Factor VII compared to PPSB; these finding revealed that factor VII migrated as alpha-2 proteins. In order to improve viral safety, solvent-detergent treatment was applied prior to further purification and nearly complete elimination of tween 80 (2 μg/ml). It was concluded that immuonoaffinity chromatography using CNBr-activated Sepharose 4B can be a suitable choice for large-scale production of factor VII concentrate with higher purity, safety and activated factor VII.

Stabilizing effects of hydrated fullerenes C₆₀ in a wide range of concentrations on luciferase, alkaline phosphatase, and peroxidase in vitro.

PubMed

Voeikov, Vladimir L; Yablonskaya, Olga I

2015-01-01

Hydrated fullerene (HyFnC60) is a highly hydrophilic supra-molecular complex consisting of unmodified С60 fullerene molecule enclosed into a hydrated shell. It has been shown in numerous experiments that aqueous solutions of HyFnC60 manifest a wide range of biological activities both in vivo and in vitro even at very low concentrations of HyFnC60. We used a spectrophotometric method and a method of biochemoluminescence to demonstrate that HyFnC60 in concentrations below 10(-9) M down to 10(-23) M stabilizes peroxidase, alkaline phosphatase, and bacterial luciferase against inactivation due to long-term incubation of the enzymes at room temperature and also against heat inactivation. In addition, HyFnC60 was able to "revive" heat inactivated enzymes. These effects cannot be explained by the direct action of the fullerene molecules upon the enzymes. We suggest that the effects of HyFnC60 on the enzymes are related to the ability of hydrated fullerene C60 molecules to organize thick aqueous shells around them. One of the specific properties of water phase in these shells is its ability to optimize redox reactions, which can support enzyme stability against factors deteriorating their structure.

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

Intracellular activity of clinical concentrations of phenothiazines including thioridiazine against phagocytosed Staphylococcus aureus.

PubMed

Ordway, Diane; Viveiros, Miguel; Leandro, Clara; Arroz, Maria Jorge; Amaral, Leonard

2002-07-01

The effect of thioridazine (TZ) was studied on the killing activity of human peripheral blood monocyte derived macrophages (HPBMDM) and of human macrophage cell line THP-1 at extracellular concentrations below those achievable clinically. These macrophages have nominal killing activity against bacteria and therefore, would not influence any activity that the compounds may have against intracellular localised Staphylococcus aureus. The results indicated that whereas TZ has an in vitro minimum inhibitory concentration (MIC) against the strains of S. aureus of 18, 0.1 mg/l of TZ in the medium completely inhibits the growth of S. aureus that has been phagocytosed by macrophages. The latter concentration was non-toxic to macrophages, did not cause cellular expression of activation marker CD69 nor induction of CD3+ T cell production of IFN-gamma, but blocked cellular proliferation and down-regulated the production of T cell-derived cytokines (IFN-gamma, IL-5). These results suggest that TZ induces intracellular bactericidal activities independent of the capacity to generate Type 1 responses against S. aureus.

Determination of activity coefficient of lanthanum chloride in molten LiCl-KCl eutectic salt as a function of cesium chloride and lanthanum chloride concentrations using electromotive force measurements

NASA Astrophysics Data System (ADS)

Bagri, Prashant; Simpson, Michael F.

2016-12-01

The thermodynamic behavior of lanthanides in molten salt systems is of significant scientific interest for the spent fuel reprocessing of Generation IV reactors. In this study, the apparent standard reduction potential (apparent potential) and activity coefficient of LaCl3 were determined in a molten salt solution of eutectic LiCl-KCl as a function of concentration of LaCl3. The effect of adding up to 1.40 mol % CsCl was also investigated. These properties were determined by measuring the open circuit potential of the La-La(III) redox couple in a high temperature molten salt electrochemical cell. Both the apparent potential and activity coefficient exhibited a strong dependence on concentration. A low concentration (0.69 mol %) of CsCl had no significant effect on the measured properties, while a higher concentration (1.40 mol %) of CsCl caused an increase (become more positive) in the apparent potential and activity coefficient at the higher range of LaCl3 concentrations.

Distribution of artificial gamma-ray emitting radionuclide activity concentration in the top soil in the vicinity of the Ignalina Nuclear Power Plant and other regions in Lithuania.

PubMed

Lukšienė, Benedikta; Marčiulionienė, Danutė; Rožkov, Andrej; Gudelis, Arūnas; Holm, Elis; Galvonaitė, Audronė

2012-11-15

The impact of the operating Ignalina Nuclear Power Plant (INPP) on the contamination of top soil layer with artificial radionuclides has been studied. Results of the investigation of artificial gamma-ray emitting radionuclide distribution in soil in the vicinity of the INPP and distant regions in Lithuania in 1996-2008 (INPP operational period) show that nowadays (137)Cs remains the most important artificial gamma-ray emitting radionuclide in the upper soil layer. Mean (137)Cs activity concentrations in the top soil layer in the vicinity of the INPP were found to be significantly lower compared to those in remote regions of Varėna and Plungė (~300 km from INPP). In 1996 and 1998 mean (137)Cs activity concentrations were in the range of 28-45 Bq/kg in the nearest vicinity to the INPP, 103 Bq/kg in Varėna and 340 Bq/kg in Plungė region. (137)Cs activity concentrations were 5-20 times lower in meadow soil (4-14 Bq/kg) compared to swamp and forest soil. (60)Co, the INPP origin radionuclide, was detected in samples only in 1996 and 2000, and the activity concentration of (60)Co was found to be in the range from 0.4 to 7.0 Bq/kg at the sampling ground nearest to the INPP. Average annual activity concentrations of the INPP origin (137)Cs and (60)Co in the air and depositions in the INPP region were modeled using Pasquill-Gifford equations. The modeling results of (137)Cs and (60)Co depositional load in the INPP vicinity agree with the experimentally obtained values. Our results provide the evidence that the operation of INPP did not cause any significant contamination in soil surface. Copyright © 2012 Elsevier B.V. All rights reserved.

Determination of the volume activity concentration of alpha artificial radionuclides with alpha spectrometer.

PubMed

Liu, B; Zhang, Q; Li, Y

1997-12-01

This paper introduces a method to determine the volume activity concentration of alpha and/or beta artificial radionuclides in the environment and radon/thoron progeny background-compensation based on a Si surface-barrier detector. By measuring the alpha peak counts of 218Po and 214Po in two time intervals, the activity concentration of 218Po, 214Pb and 214Bi aerosol particles were determined; meanwhile, the total beta count of 214Pb and 214Bi aerosols was also calculated from their decay scheme. With the average equilibrium factor of thoron progeny in general environment, the alpha and beta counts of thoron progeny were approximately evaluated by 212Po alpha peak counts. The alpha count of transuranic aerosols was determined by subtracting the trail counts of radon/thoron progeny alpha peaks. The total count of beta artificial radionuclides was determined by subtracting the beta counts of radon/thoron progeny aerosol particles. In our preliminary experiments, if the radon progeny concentration is less than 15 Bq m(-3), the lower limit of detection of transuranics concentration is less than 0.1 Bq m(-3). Even if the radon progeny concentration is as high as 75 Bq m(-3), the lower limit of detection of total beta activity concentration of artificial nuclides aerosols is less than 1 Bq m(-3).

Research on range-gated laser active imaging seeker

NASA Astrophysics Data System (ADS)

You, Mu; Wang, PengHui; Tan, DongJie

2013-09-01

Compared with other imaging methods such as millimeter wave imaging, infrared imaging and visible light imaging, laser imaging provides both a 2-D array of reflected intensity data as well as 2-D array of range data, which is the most important data for use in autonomous target acquisition .In terms of application, it can be widely used in military fields such as radar, guidance and fuse. In this paper, we present a laser active imaging seeker system based on range-gated laser transmitter and sensor technology .The seeker system presented here consist of two important part, one is laser image system, which uses a negative lens to diverge the light from a pulse laser to flood illuminate a target, return light is collected by a camera lens, each laser pulse triggers the camera delay and shutter. The other is stabilization gimbals, which is designed to be a rotatable structure both in azimuth and elevation angles. The laser image system consists of transmitter and receiver. The transmitter is based on diode pumped solid-state lasers that are passively Q-switched at 532nm wavelength. A visible wavelength was chosen because the receiver uses a Gen III image intensifier tube with a spectral sensitivity limited to wavelengths less than 900nm.The receiver is image intensifier tube's micro channel plate coupled into high sensitivity charge coupled device camera. The image has been taken at range over one kilometer and can be taken at much longer range in better weather. Image frame frequency can be changed according to requirement of guidance with modifiable range gate, The instantaneous field of views of the system was found to be 2×2 deg. Since completion of system integration, the seeker system has gone through a series of tests both in the lab and in the outdoor field. Two different kinds of buildings have been chosen as target, which is located at range from 200m up to 1000m.To simulate dynamic process of range change between missile and target, the seeker system has

Organochlorine contaminant concentrations in multiple tissues of free-ranging Steller sea lions (Eumetopias jubatus) in Alaska.

PubMed

Beckmen, Kimberlee B; Keogh, Mandy J; Burek-Huntington, Kathleen A; Ylitalo, Gina M; Fadely, Brian S; Pitcher, Kenneth W

2016-01-15

The relationships of selected organochlorine (OC) contaminants between blubber, blood, feces, and milk of young, free-ranging Steller sea lions (Eumetopias jubatus) were examined. Both between and within each tissue there was considerable individual variation. In spite of the variation, similar patterns were observed across the tissues for most of the selected PCB congeners. In all four tissues, the major PCB congeners were PCB101, PCB118, PCB138, and PCB153. The most prominent congener, both as a weight (ng/g lipid) and as a percentage of summed PCBs (∑PCBs), was PCB 153. Comparisons between paired tissues showed that ∑DDTs in blubber samples were related to concentrations in blood, feces, and milk. The ∑PCBs in blubber were related to concentrations in milk and fecal samples, though the relationship with feces was weak. Our findings show milk samples, in particular, are useful for assessing OCs in young sea lions. Blubber concentrations of PCB101, PCB118, and PCB138 were an order of magnitude higher than those in milk, supporting the biomagnification of these PCB congeners in SSL tissues. The findings indicate alternative tissues may be used as indicators of relative contaminant exposure in lieu of surgical blubber biopsy. Copyright © 2015 Elsevier B.V. All rights reserved.

Identification, contribution, and estrogenic activity of potential EDCs in a river receiving concentrated livestock effluent in Southern Taiwan.

PubMed

Liu, Yung-Yu; Lin, Yi-Siou; Yen, Chia-Hung; Miaw, Chang-Ling; Chen, Ting-Chien; Wu, Meng-Chun; Hsieh, Chi-Ying

2018-04-27

We assessed 22 selected endocrine-disrupting compounds (EDCs) and other emerging, potentially endocrine-active compounds with estrogenic activity from the waters of the Wuluo River, southern Taiwan. This watershed receives high amounts of livestock and untreated household wastewaters. The river is surrounded by concentrated animal feedlot operations (CAFOs). River water samples were analyzed for selected compounds by liquid chromatography-tandem mass spectrometry (LC-MS/MS), T47D-KBluc reporter gene assay, and E-screen cell proliferation in vitro bioassay. Total concentrations of ∑alkylphenolic compounds (bisphenol A, 4-nonylphenol, t-nonylphenol, octylphenol, nonylphenol mono-ethoxylate, nonylphenol di-ethoxylate) were much higher than ∑estrogens (estrone, 17 β-estradiol, estriol, 17ß-ethynylestradiol, diethylstilbestrol), ∑preservatives (methyl paraben, ethyl paraben, propyl paraben, butyl paraben), ∑UV-filters (benzophenone, methyl benzylidene camphor, benzophenone-3), ∑antimicrobials (triclocarben, triclosan, chloroxylenol), and an insect repellent (diethyltoluamide) over four seasonal sampling periods. The highest concentration was found for bisphenol A with a mean of 302 ng/L. However, its contribution to estrogenic activity was not significant due to its relatively low estrogenic potency. Lower detection rates were found for BP, EE2, TCS, and PCMX, while DES and EP were not detected. E1 and E2 levels in raw water samples were 50% higher than the predicted no-effect concentrations (PNEC) for aquatic organisms of 6 and 2 ng/L, respectively. The potency of estrogenic activity ranged from 11.7 to 190.1 ng/L E2 T47D-Kbluc and 6.63 to 84.5 ng/L E2 E-Screen for extracted samples. Importantly, estrone contributed 50% of the overall activity in 60% and 44% of the samples based on T47D-KBluc and MCF-7 bioassays, followed by 17 ß-estradiol, highlighting the importance of total steroid estrogen loading. This study demonstrates that the estrogenic

Arginase activity, urea, and hydroxyproline concentration are reduced in keratoconus keratocytes.

PubMed

Stachon, Tanja; Kolev, Krasimir; Flaskó, Zsuzsa; Seitz, Berthold; Langenbucher, Achim; Szentmáry, Nóra

2017-01-01

Keratoconus (KC) is a disease characterized by thinning and deformation of the cornea, but its etiology remains unknown. Seventy percent of the corneal stroma consists of collagen, which is composed of three intertwined polypeptide chains with glycine-hydroxyproline-proline repeats along their sequence. Arginase is a cytoplasmatic enzyme and catalyzes the conversion of arginine to urea and ornithine, which serves as a precursor for the endogenous synthesis of proline and hydroxyproline. The purpose of this study was to analyze arginase activity, as well as collagen and urea formation in normal and KC-keratocytes and to determine the impact of urea on keratocyte viability and proliferation in vitro. Primary human keratocytes were isolated by digestion in collagenase (1.0 mg/mL) from surgically removed corneas of eight keratoconus patients and eight normal human corneal buttons and cultured in DMEM/Ham's F12 medium supplemented with 5 % fetal calf serum. Arginase activity and urea concentration were measured in cell-lysates, hydroxyproline concentration in supernatant of cultured keratocytes using colorimetric assay. Cell viability and cell proliferation of cultured keratocytes were assessed after treatment with urea at concentrations up to10 mM for 24 h using assays for metabolic activity and DNA replication. Arginase activity and urea concentration in KC-keratocytes decreased by about 50 % compared to normal keratocytes (p = 0.003 and p = 0.008). Hydroxyproline synthesized by cultured KC-keratocytes was also approximately 50 % less compared to normal keratocytes (p = 0.02) and this difference decreased following treatment with 5.0 or 10.0 mM urea (p = 0.02; 0.03), without any change in cell viability (p > 0.09). However, the urea treatment increased modestly (by 20 %) the proliferation rate of KC-keratocytes (p = 0.04; 0.04; 0.04), without any effect on normal cultured keratocytes (p > 0.09). We identified suppressed arginase

[Effect of tobacco smoking on albumin concentration and β-glucuronidase activity in urine of smelters].

PubMed

Bizonń, Anna; Witt, Katarzyna; Milnerowicz, Malgorzata; Milnerowicz, Halina

2014-01-01

The aim of present study was to estimate the nephrotoxicity of occupational exposure to heavy metals on albumin concentration and β-glucuronidase activity in the urine of smoking and non-smoking smelters. The study was performed in urine of 101 smoking and non-smoking smelters as well as 65 smoking and non-smoking male subjects unexposed to heavy metals. Section into smoking and non-smoking groups was made on basis on direct personal interview and by determination of serum cotinine concentration. The concentration of albumin in urine was measured with commercial test (Micro-Albumin ELISA Cat. No 5MA 74212, ORGENTEC Diagnostika Gmbh, Germany). The activity of β-glucuronidase in urine were determined in urine using 4-nitrophenyl β D-glucuronide (Cat. No 73677, Sigma Aldrich, Germany) as a substrate. We have observed higher albumin concentration and β-glucuronidase activity in urine of smoking and non-smoking smelters when compared to control groups. We have also found the influence of tobacco smoke as well as amount of cigarettes smoked on albumin concentration in urine of smoking smelters. A statistically significant difference was detected between activity of β-glucuronidase in urine of smoking and non-smoking smelters, which suggest as additional negative factor of exposure to tobacco smoke. Analyzing the impact of smoking intensity we have found higher albumin concentration and β-glucuronidase activity in urine of smelters smoking ≥20 cigarettes per day when compared to smelters smoking <20 cigarettes per day. The elevation of albumin concentration and β-glucuronidase activity in urine of workers occupational exposure to heavy metals and tobacco smoke indicated, that environmental exposure on these factors can disorders kidney functions.

Climate dominated topography in a tectonically active mountain range

NASA Astrophysics Data System (ADS)

Adams, B. A.; Ehlers, T. A.

2015-12-01

Tests of the interactions between tectonic and climate forcing on Earth's topography often focus on the concept of steady-state whereby processes of rock deformation and erosion are opposing and equal. However, when conditions change such as the climate or tectonic rock uplift, then surface processes act to restore the balance between rock deformation and erosion by adjusting topography. Most examples of canonical steady-state mountain ranges lie within the northern hemisphere, which underwent a radical change in the Quaternary due to the onset of widespread glaciation. The activity of glaciers changed erosion rates and topography in many of these mountain ranges, which likely violates steady-state assumptions. With new topographic analysis, and existing patterns of climate and rock uplift, we explore a mountain range previously considered to be in steady-state, the Olympic Mountains, USA. The broad spatial trend in channel steepness values suggests that the locus of high rock uplift rates is coincident with the rugged range core, in a similar position as high temperature and pressure lithologies, but not in the low lying foothills as has been previously suggested by low-temperature thermochronometry. The details of our analysis suggest the dominant topographic signal in the Olympic Mountains is a spatial, and likely temporal, variation in erosional efficiency dictated by orographic precipitation, and Pleistocene glacier ELA patterns. We demonstrate the same topographic effects are recorded in the basin hypsometries of other Cenozoic mountain ranges around the world. The significant glacial overprint on topography makes the argument of mountain range steadiness untenable in significantly glaciated settings. Furthermore, our results suggest that most glaciated Cenozoic ranges are likely still in a mode of readjustment as fluvial systems change topography and erosion rates to equilibrate with rock uplift rates.

Importance of plant species and external silicon concentration to active silicon uptake and transport.

PubMed

Liang, Yongchao; Hua, Haixia; Zhu, Yong-Guan; Zhang, Jie; Cheng, Chunmei; Römheld, Volker

2006-01-01

Here, we characterized silicon (Si) uptake and xylem loading in Oryza sativa, Zea mays, Helianthus annuus and Benincase hispida in a series of hydroponic experiments. Both active and passive Si-uptake components co-exist in all the plants tested. The active component is the major mechanism responsible for Si uptake in O. sativa and Z. mays. By contrast, passive uptake prevails in H. annuus and B. hispida at a higher external Si concentration (0.85 mM), while the active component constantly exists and contributes to the total Si uptake, especially at a lower external Si concentration (0.085 mM). Short experiments showed that Si uptake was significantly suppressed in O. sativa and Z. mays by metabolic inhibitors or low temperature, regardless of external Si concentrations. By contrast, Si uptake in H. annuus and B. hispida was inhibited more significantly by metabolic inhibitors or low temperature at lower (for example, 0.085 mM) than at higher (for example, 1.70 mM) external Si concentrations. It can be concluded that both active and passive Si-uptake components co-exist in O. sativa, Z. mays, H. annuus and B. hispida, with their relative contribution being dependent much upon both plant species and external Si concentrations.

Thermodynamics-Based Models of Transcriptional Regulation by Enhancers: The Roles of Synergistic Activation, Cooperative Binding and Short-Range Repression

PubMed Central

He, Xin; Samee, Md. Abul Hassan; Blatti, Charles; Sinha, Saurabh

2010-01-01

Quantitative models of cis-regulatory activity have the potential to improve our mechanistic understanding of transcriptional regulation. However, the few models available today have been based on simplistic assumptions about the sequences being modeled, or heuristic approximations of the underlying regulatory mechanisms. We have developed a thermodynamics-based model to predict gene expression driven by any DNA sequence, as a function of transcription factor concentrations and their DNA-binding specificities. It uses statistical thermodynamics theory to model not only protein-DNA interaction, but also the effect of DNA-bound activators and repressors on gene expression. In addition, the model incorporates mechanistic features such as synergistic effect of multiple activators, short range repression, and cooperativity in transcription factor-DNA binding, allowing us to systematically evaluate the significance of these features in the context of available expression data. Using this model on segmentation-related enhancers in Drosophila, we find that transcriptional synergy due to simultaneous action of multiple activators helps explain the data beyond what can be explained by cooperative DNA-binding alone. We find clear support for the phenomenon of short-range repression, where repressors do not directly interact with the basal transcriptional machinery. We also find that the binding sites contributing to an enhancer's function may not be conserved during evolution, and a noticeable fraction of these undergo lineage-specific changes. Our implementation of the model, called GEMSTAT, is the first publicly available program for simultaneously modeling the regulatory activities of a given set of sequences. PMID:20862354

Proteasome 20S in multiple myeloma: comparison of concentration and chymotrypsin-like activity in plasma and serum.

PubMed

Romaniuk, Wioletta; Kalita, Joanna; Ostrowska, Halina; Kloczko, Janusz

2018-03-05

The ubiquitin-proteasome system is relevant in the pathobiology of many haematological malignancies, including multiple myeloma. The assessment of proteasome concentration and chymotrypsin-like (ChT-L) activity might constitute a new approach to diagnosis, prognosis and monitoring of anticancer treatment of patients with haematological malignancies and other diseases. The aim of our study was to determine which material, plasma or serum, is better for measuring chymotrypsin-like (ChT-L) activity and proteasome concentration. We analysed proteasome concentration and chymotrypsin-like (ChT-L) activity in 70 plasma and serum samples drawn from 28 patients at different treatment stages for multiple myeloma (MM) and 31 healthy volunteers. Proteasome ChT-L activity and concentration in multiple myeloma patients were significantly higher in plasma compared to serum. In this group we observed significant and positive correlations both between the plasma and serum proteasome ChT-L activity and plasma and serum proteasome concentration. The higher values of proteasome concentration and ChT-L activity in plasma than in serum and their better correlations with parameters of tumour load and prognosis suggest that plasma constitutes a better biological material for measuring ChT-L activity and proteasome concentration than serum in multiple myeloma patients.

HTO and OBT activity concentrations in soil at the historical atmospheric HT release site (Chalk River Laboratories).

PubMed

Kim, S B; Bredlaw, M; Korolevych, V Y

2012-01-01

Tritium is routinely released by the Chalk River Laboratories (CRL) nuclear facilities. Three International HT release experiments have been conducted at the CRL site in the past. The site has not been disturbed since the last historical atmospheric testing in 1994 and presents an opportunity to assess the retention of tritium in soil. This study is devoted to the measurement of HTO and OBT activity concentration profiles in the subsurface 25 cm of soil. In terms of soil HTO, there is no evidence from the past HT release experiments that HTO was retained. The HTO activity concentration in the soil pore water appears similar to concentrations found in background areas in Ontario. In contrast, OBT activity concentrations in soil at the same site were significantly higher than HTO activity concentrations in soil. Elevated OBT appears to reside in the top layer of the soil (0-5 cm). In addition, OBT activity concentrations in the top soil layer did not fluctuate much with season, again, quite in contrast with soil HTO. This result suggests that OBT activity concentrations retained the signature of the historical tritium releases. Crown Copyright © 2011. Published by Elsevier Ltd. All rights reserved.

Surface Colonization and Activity of the 2,6-Dichlorobenzamide (BAM) Degrading Aminobacter sp. Strain MSH1 at Macro- and Micropollutant BAM Concentrations.

PubMed

Sekhar, Aswini; Horemans, Benjamin; Aamand, Jens; Sørensen, Sebastian R; Vanhaecke, Lynn; Bussche, Julie Vanden; Hofkens, Johan; Springael, Dirk

2016-09-20

Aminobacter sp. MSH1 uses the groundwater micropollutant 2,6-dichlorobenzamide (BAM) as a C and N source and is a potential catalyst for biotreatment of BAM-contaminated groundwater in filtration units of drinking water treatment plants (DWTPs). The oligotrophic environment of DWTPs including trace pollutant concentrations, and the high flow rates impose challenges for micropollutant biodegradation in DWTPs. To understand how trace BAM concentrations affect MSH1 surface colonization and BAM degrading activity, MSH1 was cultivated in flow channels fed continuously with BAM macro- and microconcentrations in a N- and C-limiting medium. At all BAM concentrations, MSH1 colonized the flow channel. BAM degradation efficiencies were concentration-dependent, ranging between 70 and 95%. Similarly, BAM concentration affected surface colonization, but at 100 μg/L BAM and lower, colonization was similar to that in systems without BAM, suggesting that assimilable organic carbon and nitrogen other than those supplied by BAM sustained colonization at BAM microconcentrations. Comparison of specific BAM degradation rates in flow channels and in cultures of suspended freshly grown cells indicated that starvation conditions in flow channels receiving BAM microconcentrations resulted into MSH1 biomasses with 10-100-times reduced BAM degrading activity and provided a kinetic model for predicting BAM degradation under continuous C and N starvation.

NREL to Host Range of Activities for Energy Awareness Month

Science.gov Websites

Host Range of Activities for Energy Awareness Month Events devoted to energy savings Golden, Colo., Sept. 20, 2000 - Visitors will get an inside look at advanced energy technologies and learn tips for cutting utility bills when the U.S. Department of Energy's National Renewable Energy

Comparison of several von Willebrand factor (VWF) activity assays for monitoring patients undergoing treatment with VWF/FVIII concentrates: improved performance with a new modified automated method.

PubMed

Hillarp, A; Friedman, K D; Adcock-Funk, D; Tiefenbacher, S; Nichols, W L; Chen, D; Stadler, M; Schwartz, B A

2015-11-01

The ability of von Willebrand factor (VWF) to bind platelet GP Ib and promote platelet plug formation is measured in vitro using the ristocetin cofactor (VWF:RCo) assay. Automated assay systems make testing more accessible for diagnosis, but do not necessarily improve sensitivity and accuracy. We assessed the performance of a modified automated VWF:RCo assay protocol for the Behring Coagulation System (BCS(®) ) compared to other available assay methods. Results from different VWF:RCo assays in a number of specialized commercial and research testing laboratories were compared using plasma samples with varying VWF:RCo activities (0-1.2 IU mL(-1) ). Samples were prepared by mixing VWF concentrate or plasma standard into VWF-depleted plasma. Commercially available lyophilized standard human plasma was also studied. Emphasis was put on the low measuring range. VWF:RCo accuracy was calculated based on the expected values, whereas precision was obtained from repeated measurements. In the physiological concentration range, most of the automated tests resulted in acceptable accuracy, with varying reproducibility dependent on the method. However, several assays were inaccurate in the low measuring range. Only the modified BCS protocol showed acceptable accuracy over the entire measuring range with improved reproducibility. A modified BCS(®) VWF:RCo method can improve sensitivity and thus enhances the measuring range. Furthermore, the modified BCS(®) assay displayed good precision. This study indicates that the specific modifications - namely the combination of increased ristocetin concentration, reduced platelet content, VWF-depleted plasma as on-board diluent and a two-curve calculation mode - reduces the issues seen with current VWF:RCo activity assays. © 2015 John Wiley & Sons Ltd.

[Activity of alpha-amylase and concentration of protein in saliva of pregnant women].

PubMed

Ciejak, Magdalena; Olszewska, Maria; Jakubowska, Katarzyna; Zebiełowicz, Dariusz; Safranow, Krzysztof; Chlubek, Dariusz

2007-01-01

One of the hypothetical reasons of the increased incidence of caries in women during the pregnancy may be the increased activity of alpha-amylase, which can be found in their saliva. The enzyme takes part in the process of decomposition of simple sugars, which make basic substrate for caries-causing bacteria. The aim of the paper was the evaluation of the influence of pregnancy and gestational age on the activity of alpha-amylase and the concentration of protein in women's saliva. The examined group consisted of 64 pregnant women at age 17-39, between 21st and 40th week of pregnancy. The control group consisted of 44 healthy women at age 20-35, who were not pregnant. In saliva, which was taken before morning meal, without stimulation, protein concentration was determined by Bradford method and the activity of amylase was determined by kinetic method. The activity of amylase correlated strongly and positively with protein concentration in saliva of both the pregnant (RS = +0.65; p < 0.00001) and the control group (RS = +0.74; p < 0.00001) women. There were no significant differences between examined parameters in the examined and the control group. It has been observed in the examined group, that there is the significant negative correlation between protein concentration in saliva and the week of pregnancy (RS = -0.35; p <0.01). It has been observed, in conducted researches, that there is no relation between the activity of amylase and the pregnancy and gestational age, which proves against the essential role of this enzyme in the increased caries incidence of pregnant women. However, the observed changes of total protein concentration in saliva during pregnancy, suggest that the exact cognition of proteins in pregnant women's saliva may reveal new mechanisms, which lead to an increase of caries risk.

Relative contribution of AtHAK5 and AtAKT1 to K+ uptake in the high-affinity range of concentrations.

PubMed

Rubio, Francisco; Nieves-Cordones, Manuel; Alemán, Fernando; Martínez, Vicente

2008-12-01

The relative contribution of the high-affinity K(+) transporter AtHAK5 and the inward rectifier K(+) channel AtAKT1 to K(+) uptake in the high-affinity range of concentrations was studied in Arabidopsis thaliana ecotype Columbia (Col-0). The results obtained with wild-type lines, with T-DNA insertion in both genes and specific uptake inhibitors, show that AtHAK5 and AtAKT1 mediate the NH4+-sensitive and the Ba(2+)-sensitive components of uptake, respectively, and that they are the two major contributors to uptake in the high-affinity range of Rb(+) concentrations. Using Rb(+) as a K(+) analogue, it was shown that AtHAK5 mediates absorption at lower Rb(+) concentrations than AtAKT1 and depletes external Rb(+) to values around 1 muM. Factors such as the presence of K(+) or NH4+ during plant growth determine the relative contribution of each system. The presence of NH4+ in the growth solution inhibits the induction of AtHAK5 by K(+) starvation. In K(+)-starved plants grown without NH4+, both systems are operative, but when NH4+ is present in the growth solution, AtAKT1 is probably the only system mediating Rb(+) absorption, and the capacity of the roots to deplete Rb(+) is reduced.

Active and Inactive Enhancers Cooperate to Exert Localized and Long-Range Control of Gene Regulation.

PubMed

Proudhon, Charlotte; Snetkova, Valentina; Raviram, Ramya; Lobry, Camille; Badri, Sana; Jiang, Tingting; Hao, Bingtao; Trimarchi, Thomas; Kluger, Yuval; Aifantis, Iannis; Bonneau, Richard; Skok, Jane A

2016-06-07

V(D)J recombination relies on the presence of proximal enhancers that activate the antigen receptor (AgR) loci in a lineage- and stage-specific manner. Unexpectedly, we find that both active and inactive AgR enhancers cooperate to disseminate their effects in a localized and long-range manner. Here, we demonstrate the importance of short-range contacts between active enhancers that constitute an Igk super-enhancer in B cells. Deletion of one element reduces the interaction frequency between other enhancers in the hub, which compromises the transcriptional output of each component. Furthermore, we establish that, in T cells, long-range contact and cooperation between the inactive Igk enhancer MiEκ and the active Tcrb enhancer Eβ alters enrichment of CBFβ binding in a manner that impacts Tcrb recombination. These findings underline the complexities of enhancer regulation and point to a role for localized and long-range enhancer-sharing between active and inactive elements in lineage- and stage-specific control. Copyright © 2016 The Author(s). Published by Elsevier Inc. All rights reserved.

Seasonal variations in activity concentrations of 99Tc and 137Cs in the edible meat fraction of crabs and lobsters from the central Irish Sea.

PubMed

Copplestone, D; Jackson, D; Hartnoll, R G; Johnson, M S; McDonald, P; Wood, N

2004-01-01

Discharges of most radionuclides into the Irish Sea from the BNFL site at Sellafield have decreased over the past 20 years or so. For a few radionuclides, however, discharges have peaked more recently. Notably, operation of the Enhanced Actinide Removal Plant (EARP) since 1994 has led to an increase in discharges of (99)Tc, as a result of the treatment of previously stored waste, with consequent increases in (99)Tc activity concentrations in a number of marine species, particularly in crustaceans such as lobsters. Previous research has considered the significance of factors such as sex and body weight on radionuclide concentrations. The current project set out to investigate whether seasonal variations in radionuclide concentrations in crabs and lobsters occur, with particular emphasis on the dynamics of (99)Tc and (137)Cs. Organisms were obtained from a site off the Isle of Man, where radionuclide concentrations were measurable but the site was sufficiently distant from Sellafield that the radionuclides were well mixed in the water column and not likely to be influenced by the pulsed nature of discharges of (99)Tc. Crab and lobster samples were collected monthly, between February 2000 and February 2001. Fifteen or 16 individuals (evenly split as male and female) of each species were collected on each occasion. Seawater samples were also collected over the 12-month period. Activity concentrations of (99)Tc in the edible meat fraction (both brown and white meat) ranged from 0.23 to 2.46 Bq kg(-1) (fresh weight (fw)) in crabs and 124 to 216 Bq kg(-1) (fw) in lobsters, with no observed seasonal variations. Activity concentrations of (137)Cs in both crab and lobster were lower, ranging from <0.16 to 0.85 Bq kg(-1) for crab meat (fw) and <0.3 to 3.3 Bq kg(-1) for lobster meat (fw). A statistically significant increase in activity concentrations of (137)Cs in the meat was observed in the summer months for both crab and lobster. The cause has not been investigated but may

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)

Long-range dismount activity classification: LODAC

NASA Astrophysics Data System (ADS)

Garagic, Denis; Peskoe, Jacob; Liu, Fang; Cuevas, Manuel; Freeman, Andrew M.; Rhodes, Bradley J.

2014-06-01

Continuous classification of dismount types (including gender, age, ethnicity) and their activities (such as walking, running) evolving over space and time is challenging. Limited sensor resolution (often exacerbated as a function of platform standoff distance) and clutter from shadows in dense target environments, unfavorable environmental conditions, and the normal properties of real data all contribute to the challenge. The unique and innovative aspect of our approach is a synthesis of multimodal signal processing with incremental non-parametric, hierarchical Bayesian machine learning methods to create a new kind of target classification architecture. This architecture is designed from the ground up to optimally exploit correlations among the multiple sensing modalities (multimodal data fusion) and rapidly and continuously learns (online self-tuning) patterns of distinct classes of dismounts given little a priori information. This increases classification performance in the presence of challenges posed by anti-access/area denial (A2/AD) sensing. To fuse multimodal features, Long-range Dismount Activity Classification (LODAC) develops a novel statistical information theoretic approach for multimodal data fusion that jointly models multimodal data (i.e., a probabilistic model for cross-modal signal generation) and discovers the critical cross-modal correlations by identifying components (features) with maximal mutual information (MI) which is efficiently estimated using non-parametric entropy models. LODAC develops a generic probabilistic pattern learning and classification framework based on a new class of hierarchical Bayesian learning algorithms for efficiently discovering recurring patterns (classes of dismounts) in multiple simultaneous time series (sensor modalities) at multiple levels of feature granularity.

Comparative Measurements of Radon Concentration in Soil Using Passive and Active Methods in High Level Natural Radiation Area (HLNRA) of Ramsar

PubMed Central

Amanat, B; Kardan, M R; Faghihi, R; Hosseini Pooya, S M

2013-01-01

Background: Radon and its daughters are amongst the most important sources of natural exposure in the world. Soil is one of the significant sources of radon/thoron due to both radium and thorium so that the emanated thoron from it may cause increased uncertainties in radon measurements. Recently, a diffusion chamber has been designed and optimized for passive discriminative measurements of radon/thoron concentrations in soil. Objective: In order to evaluate the capability of the passive method, some comparative measurements (with active methods) have been performed. Method: The method is based upon measurements by a diffusion chamber, including two Lexan polycarbonate SSNTDs, which can discriminate the emanated radon/thorn from the soil by delay method. The comparative measurements have been done in ten selected points of HLNRA of Ramsar in Iran. The linear regression and correlation between the results of two methods have been studied. Results: The results show that the radon concentrations are within the range of 12.1 to 165 kBq/m3 values. The correlation between the results of active and passive methods was measured by 0.99 value. As well, the thoron concentrations have been measured between 1.9 to 29.5 kBq/m3 values at the points. Conclusion: The sensitivity as well as the strong correlation with active measurements shows that the new low-cost passive method is appropriate for accurate seasonal measurements of radon and thoron concentration in soil. PMID:25505760

Adsorption of Crystal Violet on Activated Carbon Prepared from Coal Flotation Concentrate

NASA Astrophysics Data System (ADS)

Aydogmus, Ramazan; Depci, Tolga; Sarikaya, Musa; Riza Kul, Ali; Onal, Yunus

2016-10-01

The objective of this study is firstly to investigate the floatability properties of Zilan- Van coal after microwave irradiation and secondly to produce activated carbon from flotation concentrate in order to remove Crystal Violet (CV) from waste water. The flotation experiments showed that microwave heating at 0.9 kW power level for 60 sec exposure time enhanced the hydrophobicity and increased the flotation yield. The activated carbon with remarkable surface area (696 m2/g) was produced from the flotation concentrate and used to adsorb CV from aqueous solution in a batch reactor at different temperature. The adsorption properties of CV onto the activated carbon are discussed in terms of the adsorption isotherms (Langmuir and Freundlich) and found that the experimental results best fitted by the Langmuir model.

An Assessment of the Model of Concentration Addition for Predicting the Estrogenic Activity of Chemical Mixtures in Wastewater Treatment Works Effluents

PubMed Central

Thorpe, Karen L.; Gross-Sorokin, Melanie; Johnson, Ian; Brighty, Geoff; Tyler, Charles R.

2006-01-01

The effects of simple mixtures of chemicals, with similar mechanisms of action, can be predicted using the concentration addition model (CA). The ability of this model to predict the estrogenic effects of more complex mixtures such as effluent discharges, however, has yet to be established. Effluents from 43 U.K. wastewater treatment works were analyzed for the presence of the principal estrogenic chemical contaminants, estradiol, estrone, ethinylestradiol, and nonylphenol. The measured concentrations were used to predict the estrogenic activity of each effluent, employing the model of CA, based on the relative potencies of the individual chemicals in an in vitro recombinant yeast estrogen screen (rYES) and a short-term (14-day) in vivo rainbow trout vitellogenin induction assay. Based on the measured concentrations of the four chemicals in the effluents and their relative potencies in each assay, the calculated in vitro and in vivo responses compared well and ranged between 3.5 and 87 ng/L of estradiol equivalents (E2 EQ) for the different effluents. In the rYES, however, the measured E2 EQ concentrations in the effluents ranged between 0.65 and 43 ng E2 EQ/L, and they varied against those predicted by the CA model. Deviations in the estimation of the estrogenic potency of the effluents by the CA model, compared with the measured responses in the rYES, are likely to have resulted from inaccuracies associated with the measurement of the chemicals in the extracts derived from the complex effluents. Such deviations could also result as a consequence of interactions between chemicals present in the extracts that disrupted the activation of the estrogen response elements in the rYES. E2 EQ concentrations derived from the vitellogenic response in fathead minnows exposed to a series of effluent dilutions were highly comparable with the E2 EQ concentrations derived from assessments of the estrogenic potency of these dilutions in the rYES. Together these data support the

210Po and 210Pb Activity Concentrations in Cigarettes Produced in Vietnam and Their Estimated Dose Contribution Due to Smoking

NASA Astrophysics Data System (ADS)

Tran, Thuy-Ngan N.; Le, Cong-Hao; Chau, Van-Tao

Smoking cigarettes contributes significantly to the increase of radiation in human body because 210Po and 210Pb exist relatively high in tobacco leaves. Therefore, these two radioisotopes in eighteen of the most frequently sold cigarette brands produced in Vietnam were examined in this study. 210Po was determined by alpha spectroscopy using a passivated implanted planar silicon (PIPS) detector after a procedure including radiochemical separation and spontaneous deposition of polonium on a copper disc (the deposition efficiency of 210Po on a copper disc was approximately 94%). Sequentially, 210Pb was determined through the ingrowth of 210Po after storing the sample solutions for approximately six months. The activity concentrations of 210Po in cigarettes ranged from 13.8 to 82.6 mBq/cigarette (the mean value was 26.4 mBq/cigarette) and the activity concentrations of 210Pb in cigarettes ranged from 13.9 to 78.8 mBq/cigarette (the mean value was 25.8 mBq/cigarette). The annual committed effective dose for smokers who smoke one pack per day was also estimated to be 295.4 µSv/year (223.0 µSv/year and 72.4 µSv/year from 210Po and 210Pb, respectively). These indicated that smoking increased the risk of developing lung cancer was approximately 60 times greater for smokers than for non-smokers.

A comparison of muscle activity in concentric and counter movement maximum bench press.

PubMed

van den Tillaar, Roland; Ettema, Gertjan

2013-01-01

The purpose of this study was to compare the kinematics and muscle activation patterns of regular free-weight bench press (counter movement) with pure concentric lifts in the ascending phase of a successful one repetition maximum (1-RM) attempt in the bench press. Our aim was to evaluate if diminishing potentiation could be the cause of the sticking region. Since diminishing potentiation cannot occur in pure concentric lifts, the occurrence of a sticking region in this type of muscle actions would support the hypothesis that the sticking region is due to a poor mechanical position. Eleven male participants (age 21.9 ± 1.7 yrs, body mass 80.7 ± 10.9 kg, body height 1.79 ± 0.07 m) conducted 1-RM lifts in counter movement and in pure concentric bench presses in which kinematics and EMG activity were measured. In both conditions, a sticking region occurred. However, the start of the sticking region was different between the two bench presses. In addition, in four of six muscles, the muscle activity was higher in the counter movement bench press compared to the concentric one. Considering the findings of the muscle activity of six muscles during the maximal lifts it was concluded that the diminishing effect of force potentiation, which occurs in the counter movement bench press, in combination with a delayed muscle activation unlikely explains the existence of the sticking region in a 1-RM bench press. Most likely, the sticking region is the result of a poor mechanical force position.

A Comparison of Muscle Activity in Concentric and Counter Movement Maximum Bench Press

PubMed Central

van den Tillaar, Roland; Ettema, Gertjan

2013-01-01

The purpose of this study was to compare the kinematics and muscle activation patterns of regular free-weight bench press (counter movement) with pure concentric lifts in the ascending phase of a successful one repetition maximum (1-RM) attempt in the bench press. Our aim was to evaluate if diminishing potentiation could be the cause of the sticking region. Since diminishing potentiation cannot occur in pure concentric lifts, the occurrence of a sticking region in this type of muscle actions would support the hypothesis that the sticking region is due to a poor mechanical position. Eleven male participants (age 21.9 ± 1.7 yrs, body mass 80.7 ± 10.9 kg, body height 1.79 ± 0.07 m) conducted 1-RM lifts in counter movement and in pure concentric bench presses in which kinematics and EMG activity were measured. In both conditions, a sticking region occurred. However, the start of the sticking region was different between the two bench presses. In addition, in four of six muscles, the muscle activity was higher in the counter movement bench press compared to the concentric one. Considering the findings of the muscle activity of six muscles during the maximal lifts it was concluded that the diminishing effect of force potentiation, which occurs in the counter movement bench press, in combination with a delayed muscle activation unlikely explains the existence of the sticking region in a 1-RM bench press. Most likely, the sticking region is the result of a poor mechanical force position. PMID:24235985

Short-term effect of ammonia concentration and salinity on activity of ammonia oxidizing bacteria.

PubMed

Claros, J; Jiménez, E; Borrás, L; Aguado, D; Seco, A; Ferrer, J; Serralta, J

2010-01-01

A continuously aerated SHARON (single reactor high activity ammonia removal over nitrite) system has been operated to achieve partial nitritation. Two sets of batch experiments were carried out to study the effect of ammonia concentration and salinity on the activity of ammonia-oxidizing bacteria (AOB). Activity of AOB raised as free ammonia concentration was increased reaching its maximum value at 4.5 mg NH3-N l(-1). The half saturation constant for free ammonia was determined (K(NH3)=0.32 mg NH3-N l(-1)). Activity decreased at TAN (total ammonium-nitrogen) concentration over 2,000 mg NH4-N l(-1). No free ammonia inhibition was detected. The effect of salinity was studied by adding different concentrations of different salts to the biomass. No significant differences were observed between the experiments carried out with a salt containing or not containing NH4. These results support that AOB are inhibited by salinity, not by free ammonia. A mathematical expression to represent this inhibition is proposed. To compare substrate affinity and salinity inhibitory effect on different AOB populations, similar experiments were carried out with biomass from a biological nutrient removal pilot plant. The AOB activity reached its maximum value at 0.008 mg NH3-N l(-1) and decreased at TAN concentration over 400 mg NH4-N l(-1). These differences can be explained by the different AOB predominating species: Nitrosomonas europaea and N. eutropha in the SHARON biomass and Nitrosomonas oligotropha in the pilot plant.

Neutron activation measurements over an extremely wide dynamic range (invited) (abstract)

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

Barnes, C.W.

1997-01-01

The DT program at the Tokamak Fusion Test Reactor (TFTR) created requirements on 14 MeV neutron measurements to measure from 10{sup 6} n/cm{sup 2} (for triton burnup and Ohmic tritium plasmas) to {gt}10{sup 12} n/cm{sup 2} (characteristic of {gt}10 MW DT plasmas) with an accuracy of 7% (one-sigma).1 To maintain an absolute calibration over this dynamic range with active neutron detectors required one to go from some absolute standard at one fluence level to a measurement at a much higher fluence. Maintaining accuracy requires an extremely linear set of measurements not systematically affected over this dynamic range. Neutron activation canmore » provide such linearity when care is taken with a number of effects such as gamma-ray detection efficiency and sample contamination.2 Absolutely calibrated neutron yield measurements using dosimetric (well-known cross section) reactions with thin (low-mass) elemental foils is be described. This technique makes the detector comparison to an absolute standard of gamma-ray activity correspond to all neutron fluences by reducing the sample mass while keeping the activation detectors operating in a linear counting mode; i.e., low count rates which minimize pileup effects. The International Thermonuclear Experimental Reactor is projected to have 1000 s burn durations at fluxes of few 10{sup 13} n/cm{sup 2}s, or more neutron fluence {ital per second} than entire TFTR discharges. Extrapolating neutron activation to these higher fluences will require yet more care. Some of the issues at such high fluences will be discussed.3 The National Ignition Facility (NIF) is projected to yield 10 MJ of fusion energy, or up to 10{sup 12} n/cm{sup 2} at the vacuum vessel wall, similar to TFTR DT conditions. It is expected that much interesting physics will be performed at yields far less than those from ignition, covering an even greater dynamic range than needed on TFTR. Thin foil techniques do not have the sensitivity required at low fluences.« less

Blood selenium concentrations and enzyme activities related to glutathione metabolism in wild emperor geese

USGS Publications Warehouse

Franson, J. Christian; Hoffman, David J.; Schmutz, Joel A.

2002-01-01

In 1998, we collected blood samples from 63 emperor geese (Chen canagica) on their breeding grounds on the Yukon-Kuskokwim Delta (YKD) in western Alaska, USA. We studied the relationship between selenium concentrations in whole blood and the activities of glutathione peroxidase and glutathione reductase in plasma. Experimental studies have shown that plasma activities of these enzymes are useful biomarkers of selenium-induced oxidative stress, but little information is available on their relationship to selenium in the blood of wild birds. Adult female emperor geese incubating their eggs in mid-June had a higher mean concentration of selenium in their blood and a greater activity of glutathione peroxidase in their plasma than adult geese or goslings that were sampled during the adult flight feathermolting period in late July and early August. Glutathione peroxidase activity was positively correlated with the concentration of selenium in the blood of emperor geese, and the rate of increase relative to selenium was greater in goslings than in adults. The activity of glutathione reductase was greatest in the plasma of goslings and was greater in molting adults than incubating females but was not significantly correlated with selenium in the blood of adults or goslings. Incubating female emperor geese had high selenium concentrations in their blood, accompanied by increased glutathione peroxidase activity consistent with early oxidative stress. These findings indicate that further study of the effects of selenium exposure, particularly on reproductive success, is warranted in this species.

Effect of various concentrations of antibiotics on osteogenic cell viability and activity.

PubMed

Rathbone, Christopher R; Cross, Jessica D; Brown, Kate V; Murray, Clinton K; Wenke, Joseph C

2011-07-01

Infection is a common complication of open fractures. Systemic antibiotics often cause adverse events before eradication of infected bone occurs. The local delivery of antibiotics and the use of implants that deliver both growth factors and antimicrobials are ways to circumvent systemic toxicity while decreasing infection and to reach extremely high levels required to treat bacterial biofilms. When choosing an antibiotic for a local delivery system, one should consider the effect that the antibiotic has on cell viability and osteogenic activity. To address this concern, osteoblasts were treated with 21 different antibiotics over 8 concentrations from 0 to 5000 µg/ml. Osteoblast deoxyribonucleic acid content and alkaline phosphatase activity (ALP) were measured to determine cell number and osteogenic activity, respectively. Antibiotics that caused the greatest decrement include rifampin, minocycline, doxycycline, nafcillin, penicillin, ciprofloxacin, colistin methanesulfonate, and gentamicin; their cell number and ALP were significantly less than control at drug concentrations ≤ 200 µg/ml. Conversely, amikacin, tobramycin, and vancomycin were the least cytotoxic and did not appreciably affect cell number and ALP until very high concentrations were used. This comprehensive evaluation of numerous antibiotics' effects on osteoblast viability and activity will enable clinicians and researchers to choose the optimal antibiotic for treatment of infection and maintenance of healthy host bone. Copyright © 2011 Orthopaedic Research Society.

Effects of increasing size and changing europium activator concentration in KCaI3 scintillator crystals

NASA Astrophysics Data System (ADS)

Lindsey, Adam C.; Zhuravleva, Mariya; Wu, Yuntao; Stand, Luis; Loyd, Matthew; Gokhale, Sasmit; Koschan, Merry; Melcher, Charles L.

2016-09-01

KCaI3:Eu crystals have been identified as very promising for use in spectroscopic detector applications related to nuclear nonproliferation and domestic security efforts. Initial studies have shown for small crystals a few mm3 in size with 3% europium dopant concentration, a high light yield of >70,000 ph/MeV and energy resolution of ≈3% at 662 keV is attainable which is comparable with the highest performance scintillators discovered. In this work, single crystals of KCaI3 with a range of Eu2+ doping between 0 and 5 at% substituting for Ca2+ were grown at 22 mm diameter and their performance for gamma-ray spectroscopy studied. Comparisons among crystals approximately Ø22 mm×22 mm (8.4 cm3 or ≈0.5 in3) provide a more accurate understanding of how scintillation performance changes with Eu doping and increased crystal size. KCaI3 in the undoped form is shown to be a highly efficient intrinsic scintillator with a defect-related emission at 404 nm which coexists with the Eu2+ 5d-4f emission in low dopant concentrations and is completely re-absorbed in more heavily doped crystals. For larger crystals, effects from self-absorption due to Eu activation become more evident by a near doubling of decay time for 0.5 in3 crystals as the activator is increased from 0.5 to 5.0 at% Eu. Comparisons of pulse-height spectra obtained for Ø22 mm×22 mm cylinders with varying Eu concentration suggests best performance is achieved using lower Eu additions closer to 0.5-1.0 at%. Using a modified crystal packaging featuring an offset reflector geometry, 0.5 in3 crystals of KCaI3:Eu can attain under 4% energy resolution at 662 keV.

Alkylphosphocholines: influence of structural variation on biodistribution at antineoplastically active concentrations.

PubMed

Kötting, J; Berger, M R; Unger, C; Eibl, H

1992-01-01

Hexadecylphosphocholine (HPC) and octadecylphosphocholine (OPC) show very potent antitumor activity against autochthonous methylnitrosourea-induced mammary carcinomas in rats. The longer-chain and unsaturated homologue erucylphosphocholine (EPC) forms lamellar structures rather than micelles, but nonetheless exhibits antineoplastic activity. Methylnitrosourea was used in the present study to induce autochthonous mammary carcinomas in virgin Sprague-Dawley rats. At 6 and 11 days following oral therapy, the biodistribution of HPC, OPC and EPC was analyzed in the serum, tumor, liver, kidney, lung, small intestine, brain and spleen of rats by high-performance thin-layer chromatography. In contrast to the almost identical tumor response noted, the distribution of the three homologues differed markedly. The serum levels of 50 nmol/ml obtained for OPC and EPC were much lower than the value of 120 nmol/ml measured for HPC. Nevertheless, the quite different serum levels resulted in similar tumor concentrations of about 200 nmol/g for all three of the compounds. Whereas HPC preferably accumulated in the kidney (1 mumol/g), OPC was found at increased concentrations (400 nmol/g) in the spleen, kidney and lung. In spite of the high daily dose of 120 mumol/kg EPC as compared with 51 mumol/kg HPC or OPC, EPC concentrations (100-200 nmol/g) were low in most tissues. High EPC concentrations were found in the small intestine (628 nmol/g). Values of 170 nmol/g were found for HPC and OPC in the brain, whereas the EPC concentration was 120 nmol/g. Obviously, structural modifications in the alkyl chain strongly influence the distribution pattern of alkylphosphocholines in animals. Since EPC yielded the highest tissue-to-serum concentration ratio in tumor tissue (5.1) and the lowest levels in other organs, we conclude that EPC is the most promising candidate for drug development in cancer therapy.

Activity of TDT 067 (terbinafine in Transfersome) against agents of onychomycosis, as determined by minimum inhibitory and fungicidal concentrations.

PubMed

Ghannoum, Mahmoud; Isham, Nancy; Herbert, Jacqueline; Henry, William; Yurdakul, Sam

2011-05-01

TDT 067 is a novel carrier-based dosage form (liquid spray) of 15 mg/ml of terbinafine in Transfersome that has been developed to deliver terbinafine to the nail bed to treat onychomycosis. In this study, we report the in vitro activities of TDT 067 against dermatophytes, compared with those of the Transfersome vehicle, naked terbinafine, and commercially available terbinafine (1%) spray. The MICs of TDT 067 and comparators against 25 clinical strains each of Trichophyton rubrum, T. mentagrophytes, and Epidermophyton floccosum were determined according to the CLSI M38-A2 susceptibility method (2008). Minimum fungicidal concentrations (MFCs) were determined by subculturing visibly clear wells from the MIC microtiter plates. TDT 067 demonstrated potent activity against the dermatophyte strains tested, with an MIC range of 0.00003 to 0.015 μg/ml. Overall, TDT 067 MIC(50) values (defined as the lowest concentrations to inhibit 50% of the strains tested) were 8-fold and 60-fold lower than those of naked terbinafine and terbinafine spray, respectively. The Transfersome vehicle showed minimal inhibitory activity. TDT 067 demonstrated lower MFC values for T. rubrum and E. floccosum than naked terbinafine and terbinafine spray. TDT 067 has more potent antifungal activity against dermatophytes that cause nail infection than conventional terbinafine preparations. The Transfersome vehicle appears to potentiate the antifungal activity of terbinafine. Clinical investigation of TDT 067 for the topical treatment of onychomycosis is warranted.

Active and inactive enhancers co-operate to exert localized and long-range control of gene regulation

PubMed Central

Proudhon, Charlotte; Snetkova, Valentina; Raviram, Ramya; Lobry, Camille; Badri, Sana; Jiang, Tingting; Hao, Bingtao; Trimarchi, Thomas; Kluger, Yuval; Aifantis, Iannis; Bonneau, Richard; Skok, Jane A

2016-01-01

V(D)J recombination relies on the presence of proximal enhancers that activate the antigen receptor (AgR) loci in a lineage and stage specific manner. Unexpectedly we find that both active and inactive AgR enhancers co-operate to disseminate their effects in a localized and long-range manner. Here we demonstrate the importance of short-range contacts between active enhancers that constitute an Igk super-enhancer in B cells. Deletion of one element reduces the interaction frequency between other enhancers in the hub, which compromises the transcriptional output of each component. We further establish that in T cells long-range contact and co-operation between the inactive Igk enhancer, MiEκ and the active Tcrb enhancer, Eβ, alters enrichment of CBFβ binding in a manner that impacts Tcrb recombination. These findings underline the complexities of enhancer regulation and point to a role for localized and long-range enhancer-sharing between active and inactive elements in lineage and stage specific control. PMID:27239026

Self-Powered Active Sensor with Concentric Topography of Piezoelectric Fibers

NASA Astrophysics Data System (ADS)

Fuh, Yiin Kuen; Huang, Zih Ming; Wang, Bo Sheng; Li, Shan Chien

2017-01-01

In this study, we demonstrated a flexible and self-powered sensor based on piezoelectric fibers in the diameter range of nano- and micro-scales. Our work is distinctively different from previous electrospinning research; we fabricated this apparatus precisely via near-field electrospinning which has a spectacular performance to harvest mechanical deformation in arbitrary direction and a novel concentrically circular topography. There are many piezoelectric devices based on electrospinning polymeric fibers. However, the fibers were mostly patterned in parallel lines and they could be actuated in limited direction only. To overcome this predicament, we re-arranged the parallel alignment into concentric circle pattern which made it possible to collect the mechanical energy whenever the deformation is along same axis or not. Despite the change of topography, the output voltage and current could still reach to 5 V and 400 nA, respectively, despite the mechanical deformation was from different direction. This new arbitrarily directional piezoelectric generator with concentrically circular topography (PGCT) allowed the piezoelectric device to harvest more mechanical energy than the one-directional alignment fiber-based devices, and this PGCT could perform even better output which promised more versatile and efficient using as a wearable electronics or sensor.

Predicting the Activity Coefficients of Free-Solvent for Concentrated Globular Protein Solutions Using Independently Determined Physical Parameters

PubMed Central

McBride, Devin W.; Rodgers, Victor G. J.

2013-01-01

The activity coefficient is largely considered an empirical parameter that was traditionally introduced to correct the non-ideality observed in thermodynamic systems such as osmotic pressure. Here, the activity coefficient of free-solvent is related to physically realistic parameters and a mathematical expression is developed to directly predict the activity coefficients of free-solvent, for aqueous protein solutions up to near-saturation concentrations. The model is based on the free-solvent model, which has previously been shown to provide excellent prediction of the osmotic pressure of concentrated and crowded globular proteins in aqueous solutions up to near-saturation concentrations. Thus, this model uses only the independently determined, physically realizable quantities: mole fraction, solvent accessible surface area, and ion binding, in its prediction. Predictions are presented for the activity coefficients of free-solvent for near-saturated protein solutions containing either bovine serum albumin or hemoglobin. As a verification step, the predictability of the model for the activity coefficient of sucrose solutions was evaluated. The predicted activity coefficients of free-solvent are compared to the calculated activity coefficients of free-solvent based on osmotic pressure data. It is observed that the predicted activity coefficients are increasingly dependent on the solute-solvent parameters as the protein concentration increases to near-saturation concentrations. PMID:24324733

The Concentration of Nutrients in Tissues of Plantation-Grown Eastern Cottonwood (Populus deltoides Bart.)

Treesearch

M. G. Shelton; L. E. Nelson; G. L. Switzer; B. G. Blackmon

1981-01-01

Nutrient concentrations were determined for 10 tissues from each of 24 cottonwood trees that ranged in age from four to 16 years. Highest concentrations occurred in the most physiologically active tissues; i.e., stemtips, current branches and foliage. Tree age had little influence on the variation in nutrient concentration of tissues. Some differences in concentrations...

Effect of pH and nitrite concentration on nitrite oxidation rate.

PubMed

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

2011-10-01

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

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

PubMed

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

2017-09-01

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

Factors influencing suspended solids concentrations in activated sludge settling tanks.

PubMed

Kim, Y; Pipes, W O

1999-05-31

A significant fraction of the total mass of sludge in an activated sludge process may be in the settling tanks if the sludge has a high sludge volume index (SVI) or when a hydraulic overload occurs during a rainstorm. Under those conditions, an accurate estimate of the amount of sludge in the settling tanks is needed in order to calculate the mean cell residence time or to determine the capacity of the settling tanks to store sludge. Determination of the amount of sludge in the settling tanks requires estimation of the average concentration of suspended solids in the layer of sludge (XSB) in the bottom of the settling tanks. A widely used reference recommends averaging the concentrations of suspended solids in the mixed liquor (X) and in the underflow (Xu) from the settling tanks (XSB=0. 5{X+Xu}). This method does not take into consideration other pertinent information available to an operator. This is a report of a field study which had the objective of developing a more accurate method for estimation of the XSB in the bottom of the settling tanks. By correlation analysis, it was found that only 44% of the variation in the measured XSB is related to sum of X and Xu. XSB is also influenced by the SVI, the zone settling velocity at X and the overflow and underflow rates of the settling tanks. The method of averaging X and Xu tends to overestimate the XSB. A new empirical estimation technique for XSB was developed. The estimation technique uses dimensionless ratios; i.e., the ratio of XSB to Xu, the ratio of the overflow rate to the sum of the underflow rate and the initial settling velocity of the mixed liquor and sludge compaction expressed as a ratio (dimensionless SVI). The empirical model is compared with the method of averaging X and Xu for the entire range of sludge depths in the settling tanks and for SVI values between 100 and 300 ml/g. Since the empirical model uses dimensionless ratios, the regression parameters are also dimensionless and the model can be

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.

Combined effects of water temperature and copper ion concentration on catalase activity in Crassostrea ariakensis

NASA Astrophysics Data System (ADS)

Wang, Hui; Yang, Hongshuai; Liu, Jiahui; Li, Yanhong; Liu, Zhigang

2015-07-01

A central composite experimental design and response surface method were used to investigate the combined effects of water temperature (18-34°C) and copper ion concentration (0.1-1.5 mg/L) on the catalase (CAT) activity in the digestive gland of Crassostrea ariakensis. The results showed that the linear effects of temperature were significant ( P<0.01), the quadratic effects of temperature were significant ( P<0.05), the linear effects of copper ion concentration were not significant ( P>0.05), and the quadratic effects of copper ion concentration were significant ( P<0.05). Additionally, the synergistic effects of temperature and copper ion concentration were not significant ( P>0.05), and the effect of temperature was greater than that of copper ion concentration. A model equation of CAT enzyme activity in the digestive gland of C. ariakensis toward the two factors of interest was established, with R 2, Adj. R 2 and Pred. R 2 values as high as 0.943 7, 0.887 3 and 0.838 5, respectively. These findings suggested that the goodness of fit to experimental data and predictive capability of the model were satisfactory, and could be practically applied for prediction under the conditions of the study. Overall, the results suggest that the simultaneous variation of temperature and copper ion concentration alters the activity of the antioxidant enzyme CAT by modulating active oxygen species metabolism, which may be utilized as a biomarker to detect the effects of copper pollution.

Ovicidal activity of different concentrations of Pochonia chlamydosporia chlamydospores on Taenia taeniaeformis eggs.

PubMed

Braga, F R; Silva, A R; Carvalho, R O; Araújo, J V; Pinto, P S A

2011-03-01

Three concentrations of chlamydospores of the nematophagous fungus Pochonia chlamydosporia (1000, 10,000 and 20,000 per Petri dish) were evaluated in vitro on Taenia taeniaeformis eggs. Chlamydospores at each concentration were cultured in two different media: 2% water-agar (2%WA) and 2% corn-meal-agar (2%CMA). Taenia taeniaeformis eggs were plated in each chlamydospore concentration in 2%WA and 2%CMA (treated groups) and without fungus (control group). Eggs were removed from each Petri dish at intervals of 7, 14 and 21 days and classified according to ovicidal activity (type 1, type 2 and type 3 effects). Plates containing 2%CMA showed the highest percentages for type 3 effect (81.3%) on the 21st day of observation. A difference (P < 0.01) between the media 2%WA and 2%CMA for type 1 effect was observed only at a concentration of 1000 chlamydospores on the 7th day. There were differences (P < 0.01) between 2%WA and 2%CMA on the 14th and 21st days, at the concentration of 20,000 chlamydospores, for type 1 and type 3 effects. Regression curves for type 3 effect in 2%WA and 2%CMA at the tested concentrations showed higher ovicidal activity with increasing chlamydospore concentrations. Results indicate that, at concentrations of 1000, 10,000 and 20,000 per Petri dish, chlamydospores of P. chlamydosporia effectively destroyed T. taeniaeformis eggs and can be considered a potential biological control agent for this cestode.

The Effect of Kaffir Lime Leaves Distillation Residue Oleoresin Concentration on Active Paper Packaging Characteristics

NASA Astrophysics Data System (ADS)

Kawiji; Utami, R.; Ulum, S.; Khasanah, L. U.; Manuhara, G. J.; Atmaka, W.

2018-03-01

Oleoresin of kaffir lime leaves distillation residue still contains some active compounds such as Citronellal, β-Citronellol, and Linalool which potential to incorporated on the active paper packaging. The purposes of this study were to determine the effect of kaffir lime leaves distillation residue oleoresin concentration on the physical characteristics, sensory characteristics, and antimicrobial activity of the active paper packaging incorporated with kaffir lime leaves distillation residue oleoresin and to determine the functional groups of active paper packaging. The concentration of kaffir lime leaves distillation residue oleoresin were varied at 0%, 2%, 4% and 6%. The result showed that the addition of kaffir lime leaves distillation residue oleoresin increased the thickness and moisture content of the paper and decreased the tensile strengths and folding endurances of active paper packaging. The microbial inhibition tends to increase along with the higher oleoresin concentration addition. Aromatic CH group were found at a wavelength of 897.90 cm-1 of on paper packaging with 2% oleoresin indicated as functional aromatic functional group allegedly obtained from the kaffir lime leaves oleoresin.

Extremely high radon activity concentration in two adits of the abandoned uranium mine 'Podgórze' in Kowary (Sudety Mts., Poland).

PubMed

Fijałkowska-Lichwa, Lidia

2016-12-01

Measurements of radon activity concentration were conducted for a period of 6 months, from April to September 2011, in the air of two adits constituting part of the disused uranium mine 'Podgórze' in Kowary. Adits no. 19 and 19a in Kowary had been chosen owing to the occurrence within them of the highest documented radon concentrations in Poland, With levels higher than a million Bq m -3 . The main goal of this study was to characterize the level of 222 Rn activity concentration registered in selected workings of this underground space, investigate 222 Rn changes and their characteristics over selected periods of time (an hour, a day, a month, six months) and determine the effective doses, which provided the basis for estimating the risk of exposure to increased ionizing radiation for employees and visitors to the mine. The highest values of 222 Rn activity concentration inside the adits occurred at the time when visitors, guides and other members of the staff were present there. The recorded values of radon activity concentration, regardless of the time and the month when the measurement was performed, remained at an average level of 350-400 kBq m -3 . These values were far above the limit of 1.5 kBq·m -3 recommended by international guidelines. The maximum values ranged from 800 to more than 1000 kBq·m -3 . Radon activity concentration changes occurred only in periods determined by 7-h cycles of connecting and disconnecting the mechanical ventilation. For about 7 h after activating the ventilation system, between 7 a. m. and 2 p. m., and after closing the adit, between 7 p. m. and 2 a. m., 222 Rn activity concentrations decreased to levels even as low as 100 kBq·m-3. However, as early as 3-4 h after disconnecting the ventilation system, there was a sharp rise in the values of 222 Rn activity concentration, to the level higher than 800 kBq·m-3. The risk of receiving a radiation dose higher than the national standard of 1 mSv/year by members of the

Calibration on wide-ranging aluminum doping concentrations by photoluminescence in high-quality uncompensated p-type 4H-SiC

NASA Astrophysics Data System (ADS)

Asada, Satoshi; Kimoto, Tsunenobu; Ivanov, Ivan G.

2017-08-01

Previous work has shown that the concentration of shallow dopants in a semiconductor can be estimated from the photoluminescence (PL) spectrum by comparing the intensity of the bound-to-the-dopant exciton emission to that of the free exciton. In this work, we study the low-temperature PL of high-quality uncompensated Al-doped p-type 4H-SiC and propose algorithms for determining the Al-doping concentration using the ratio of the Al-bound to free-exciton emission. We use three different cryogenic temperatures (2, 41, and 79 K) in order to cover the Al-doping range from mid 1014 cm-3 up to 1018 cm-3. The Al-bound exciton no-phonon lines and the strongest free-exciton replica are used as a measure of the bound- and free-exciton emissions at a given temperature, and clear linear relationships are obtained between their ratio and the Al-concentration at 2, 41, and 79 K. Since nitrogen is a common unintentional donor dopant in SiC, we also discuss the criteria allowing one to determine from the PL spectra whether a sample can be considered as uncompensated or not. Thus, the low-temperature PL provides a convenient non-destructive tool for the evaluation of the Al concentration in 4H-SiC, which probes the concentration locally and, therefore, can also be used for mapping the doping homogeneity.

Ovarian cycle activity varies with respect to age and social status in free-ranging elephants in Addo Elephant National Park, South Africa

PubMed Central

Freeman, Elizabeth W.; Meyer, Jordana M.; Putman, Sarah B.; Schulte, Bruce A.; Brown, Janine L.

2013-01-01

Free-ranging African elephants live in a fission–fusion society, at the centre of which is the matriarch. Matriarchs are generally older females that guide their families to resources and co-ordinate group defense. While much is known about elephant society, knowledge is generally lacking about how age affects the physiology of wild elephants. Investigation of the ovarian activity of free-ranging elephants could provide insight into the reproductive ageing process, with implications for population management. Faecal samples were collected from 46 individuals ranging in age from 14 to 60 years for a 2-year period, and progestagen metabolite analyses were used to examine relationships between social status, age, season, and ovarian activity in female elephants in Addo Elephant National Park, South Africa. Social status was the strongest predictor of faecal progestagen metabolite concentrations in non-pregnant elephants, with grand matriarchs (n = 6) having the lowest values compared with matriarchs (n = 21) and non-matriarch females (n = 19). Likewise, social status and age were the strongest predictors of faecal progestagen metabolite concentrations in pregnant elephants (n = 27). The number of years since a non-pregnant female gave birth to her last calf (post-partum duration) was longer for older females with a higher social status, as well as during the dry season. Our results indicate that social standing and age of elephants are related to reproductive function, and that older females exhibit reductions in ovarian capacity. These results expand our understanding of reproduction and fertility throughout an elephant's lifespan, and the factors that impact gonadal function in free-ranging females. Given that possible over-abundance of elephants in areas such as Addo Elephant National Park is fuelling the debate over how best to manage these populations, knowledge about the reproductive potential of high-ranking females can provide managers with

Ovarian cycle activity varies with respect to age and social status in free-ranging elephants in Addo Elephant National Park, South Africa.

PubMed

Freeman, Elizabeth W; Meyer, Jordana M; Putman, Sarah B; Schulte, Bruce A; Brown, Janine L

2013-01-01

Free-ranging African elephants live in a fission-fusion society, at the centre of which is the matriarch. Matriarchs are generally older females that guide their families to resources and co-ordinate group defense. While much is known about elephant society, knowledge is generally lacking about how age affects the physiology of wild elephants. Investigation of the ovarian activity of free-ranging elephants could provide insight into the reproductive ageing process, with implications for population management. Faecal samples were collected from 46 individuals ranging in age from 14 to 60 years for a 2-year period, and progestagen metabolite analyses were used to examine relationships between social status, age, season, and ovarian activity in female elephants in Addo Elephant National Park, South Africa. Social status was the strongest predictor of faecal progestagen metabolite concentrations in non-pregnant elephants, with grand matriarchs (n = 6) having the lowest values compared with matriarchs (n = 21) and non-matriarch females (n = 19). Likewise, social status and age were the strongest predictors of faecal progestagen metabolite concentrations in pregnant elephants (n = 27). The number of years since a non-pregnant female gave birth to her last calf (post-partum duration) was longer for older females with a higher social status, as well as during the dry season. Our results indicate that social standing and age of elephants are related to reproductive function, and that older females exhibit reductions in ovarian capacity. These results expand our understanding of reproduction and fertility throughout an elephant's lifespan, and the factors that impact gonadal function in free-ranging females. Given that possible over-abundance of elephants in areas such as Addo Elephant National Park is fuelling the debate over how best to manage these populations, knowledge about the reproductive potential of high-ranking females can provide managers with

Simulating Osmotic Equilibria: A New Tool for Calculating Activity Coefficients in Concentrated Aqueous Salt Solutions.

PubMed

Bley, Michael; Duvail, Magali; Guilbaud, Philippe; Dufrêche, Jean-François

2017-10-19

Herein, a new theoretical method is presented for predicting osmotic equilibria and activities, where a bulk liquid and its corresponding vapor phase are simulated by means of molecular dynamics using explicit polarization. Calculated time-averaged number density profiles provide the amount of evaporated molecules present in the vapor phase and consequently the vapor-phase density. The activity of the solvent and the corresponding osmotic coefficient are determined by the vapor density at different solute concentrations with respect to the reference vapor density of the pure solvent. With the extended Debye-Hückel equation for the activity coefficient along with the corresponding Gibbs-Duhem relation, the activity coefficients of the solutes are calculated by fitting the osmotic coefficients. A simple model based on the combination of Poisson processes and Maxwell-Boltzmann velocity distributions is introduced to interpret statistical phenomena observed during the simulations, which are related to evaporation and recondensation. This method is applied to aqueous dysprosium nitrate [Dy(NO 3 ) 3 ] solutions at different concentrations. The obtained densities of the liquid bulk and the osmotic and activity coefficients are in good agreement with the experimental results for concentrated and saturated solutions. Density profiles of the liquid-vapor interface at different concentrations provide detailed insight into the spatial distributions of all compounds.

THE ACUTE EFFECTS OF CONCENTRIC VERSUS ECCENTRIC MUSCLE FATIGUE ON SHOULDER ACTIVE REPOSITIONING SENSE

PubMed Central

2017-01-01

Purpose/Background Shoulder proprioception is essential in the activities of daily living as well as in sports. Acute muscle fatigue is believed to cause a deterioration of proprioception, increasing the risk of injury. The purpose of this study was to evaluate if fatigue of the shoulder external rotators during eccentric versus concentric activity affects shoulder joint proprioception as determined by active reproduction of position. Study design Quasi-experimental trial. Methods Twenty-two healthy subjects with no recent history of shoulder pathology were randomly allocated to either a concentric or an eccentric exercise group for fatiguing the shoulder external rotators. Proprioception was assessed before and after the fatiguing protocol using an isokinetic dynamometer, by measuring active reproduction of position at 30 ° of shoulder external rotation, reported as absolute angular error. The fatiguing protocol consisted of sets of fifteen consecutive external rotator muscle contractions in either the concentric or eccentric action. The subjects were exercised until there was a 30% decline from the peak torque of the subjects’ maximal voluntary contraction over three consecutive muscle contractions. Results A one-way analysis of variance test revealed no statistical difference in absolute angular error (p > 0.05) between concentric and eccentric groups. Moreover, no statistical difference (p > 0.05) was found in absolute angular error between pre- and post-fatigue in either group. Conclusions Eccentric exercise does not seem to acutely affect shoulder proprioception to a larger extent than concentric exercise. Level of evidence 2b PMID:28515976

Reversible chemical restraint of free-range cattle with a concentrated combination of tiletamine-zolazepam, ketamine, and detomidine.

PubMed

Re, Michela; Blanco-Murcia, Francisco J; San Miguel, José Maria; Gómez de Segura, Ignacio A

2013-10-01

The aim of this study was to determine the efficacy of a concentrated combination of tiletamine-zolazepam [TZ, 0.53 mg/kg body weight (BW)], ketamine (Ket, 0.53 mg/kg BW), and detomidine (Det, 0.04 mg/kg BW) in the immobilization of free-range cattle for clinical procedures. The combination was administered intramuscularly to 53 animals. Anesthesia was reversed with the α2-adrenoceptor antagonist atipamezole. Locoregional anesthesia was provided with lidocaine when required. The TZKD combination induced suitable immobilization for minor surgical procedures or medical treatments. Anesthetic onset was rapid, taking a mean of 6.1 min [standard deviation (SD) 2.8 min]. The duration of anesthesia depended on the time of administration of the antagonist; the animals recovered in the standing position in 12.9 ± 8.9 min after the administration of atipamezole. The quality of anesthesia and analgesia were satisfactory. In conclusion, this TZKD combination can be used for both immobilization and minor surgical procedures in free-range cattle.

Reversible chemical restraint of free-range cattle with a concentrated combination of tiletamine–zolazepam, ketamine, and detomidine

PubMed Central

Re, Michela; Blanco-Murcia, Francisco J.; San Miguel, José Maria; Gómez de Segura, Ignacio A.

2013-01-01

The aim of this study was to determine the efficacy of a concentrated combination of tiletamine–zolazepam [TZ, 0.53 mg/kg body weight (BW)], ketamine (Ket, 0.53 mg/kg BW), and detomidine (Det, 0.04 mg/kg BW) in the immobilization of free-range cattle for clinical procedures. The combination was administered intramuscularly to 53 animals. Anesthesia was reversed with the α2-adrenoceptor antagonist atipamezole. Locoregional anesthesia was provided with lidocaine when required. The TZKD combination induced suitable immobilization for minor surgical procedures or medical treatments. Anesthetic onset was rapid, taking a mean of 6.1 min [standard deviation (SD) 2.8 min]. The duration of anesthesia depended on the time of administration of the antagonist; the animals recovered in the standing position in 12.9 ± 8.9 min after the administration of atipamezole. The quality of anesthesia and analgesia were satisfactory. In conclusion, this TZKD combination can be used for both immobilization and minor surgical procedures in free-range cattle. PMID:24124271

Interpreting Tacrolimus Concentrations During Pregnancy and Postpartum

PubMed Central

Hebert, Mary F.; Zheng, Songmao; Hays, Karen; Shen, Danny D.; Davis, Connie L.; Umans, Jason G.; Miodovnik, Menachem; Thummel, Kenneth E.; Easterling, Thomas R.

2012-01-01

Summary Pregnancy following solid organ transplantation, although considered high risk for maternal, fetal and neonatal complications, has been quite successful. Tacrolimus pharmacokinetic changes during pregnancy make interpretation of whole blood trough concentrations particularly challenging. There are multiple factors that can increase the fraction of unbound tacrolimus, including but not limited to low albumin concentration and low RBC count. The clinical titration of dosage to maintain whole blood tacrolimus trough concentrations in the usual therapeutic range can lead to elevated unbound concentrations and possibly toxicity in pregnant women with anemia and hypoalbuminemia. Measurement of plasma or unbound tacrolimus concentrations for pregnant women might better reflect the active form of the drug, though these are technically-challenging and often unavailable in usual clinical practice. Tacrolimus crosses the placenta with in utero exposure being approximately 71% of maternal blood concentrations. The lower fetal blood concentrations are likely due to active efflux transport of tacrolimus from the fetus toward the mother by placental P-glycoprotein. To date, tacrolimus has not been linked to congenital malformations, but can cause reversible nephrotoxicity and hyperkalemia in the newborn. In contrast, very small amounts of tacrolimus are excreted in the breast milk and are unlikely to elicit adverse effects in the nursing infant. PMID:23274970

Concentration and variability of ice nuclei in the subtropical maritime boundary layer

NASA Astrophysics Data System (ADS)

Welti, André; Müller, Konrad; Fleming, Zoë L.; Stratmann, Frank

2018-04-01

Measurements of the concentration and variability of ice nucleating particles in the subtropical maritime boundary layer are reported. Filter samples collected in Cabo Verde over the period 2009-2013 are analyzed with a drop freezing experiment with sensitivity to detect the few rare ice nuclei active at low supercooling. The data set is augmented with continuous flow diffusion chamber measurements at temperatures below -24 °C from a 2-month field campaign in Cabo Verde in 2016. The data set is used to address the following questions: what are typical concentrations of ice nucleating particles active at a certain temperature? What affects their concentration and where are their sources? Concentration of ice nucleating particles is found to increase exponentially by 7 orders of magnitude from -5 to -38 °C. Sample-to-sample variation in the steepness of the increase indicates that particles of different origin, with different ice nucleation properties (size, composition), contribute to the ice nuclei concentration at different temperatures. The concentration of ice nuclei active at a specific temperature varies over a range of up to 4 orders of magnitude. The frequency with which a certain ice nuclei concentration is measured within this range is found to follow a lognormal distribution, which can be explained by random dilution during transport. To investigate the geographic origin of ice nuclei, source attribution of air masses from dispersion modeling is used to classify the data into seven typical conditions. While no source could be attributed to the ice nuclei active at temperatures higher than -12 °C, concentrations at lower temperatures tend to be elevated in air masses originating from the Sahara.

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.

Activity and concentration of polyphenolic antioxidants in apple: effect of cultivar, harvest year, and storage conditions.

PubMed

van der Sluis, A A; Dekker, M; de Jager, A; Jongen, W M

2001-08-01

Consumers' increasing interest in the relationship between diet and health is a sign for food producers to pay more attention to potential health-protecting compounds in new product development and food processing. From a production chain perspective the choice of the raw material that is used is important for the health-protecting potential of the end product. Four apple cultivars (Jonagold, Golden Delicious, Cox's Orange, and Elstar), which can be used as fresh apples or in processed apple products, were compared with regard to flavonol, catechins, phloridzin, and chlorogenic acid concentrations and antioxidant activity. Jonagold apples possessed the highest flavonoid concentration and the highest antioxidant activity. To study seasonal differences, apples from three different harvest years were analyzed, but in three cultivars no effect on flavonoid concentration and antioxidant activity was observed. Long-term storage, both at refrigerator temperature and under controlled atmosphere conditions, was found not to influence flavonoid concentration or antioxidant activity.

Effects of plasma nitric oxide levels on platelet activation in single donor apheresis and random donor concentrates.

PubMed

Büyükkağnici, Demet Iren; Ilhan, Osman; Kavas, Güzin Ozelçi; Arslan, Onder; Arat, Mutlu; Dalva, Klara; Ayyildiz, Erol

2007-02-01

P-selectin is an useful marker to determine platelet activation and nitric oxide inhibits platelet activation, secretion, adhesion and aggregation. The aim of this study was to investigate the relationship between nitric oxide and P-selectin values in both single donor apheresis and random donor platelet concentrates. According to the results of this study, we found that the best platelet concentrate is freshly prepared single donor apheresis concentrate and it is important to prevent activation at the beginning of the donation. Nitric oxide, which is synthesized from platelets during the storage period, is not sufficient to prevent platelet activation.

Emergent ultra–long-range interactions between active particles in hybrid active–inactive systems

PubMed Central

Steimel, Joshua P.; Aragones, Juan L.; Hu, Helen; Qureshi, Naser; Alexander-Katz, Alfredo

2016-01-01

Particle–particle interactions determine the state of a system. Control over the range of such interactions as well as their magnitude has been an active area of research for decades due to the fundamental challenges it poses in science and technology. Very recently, effective interactions between active particles have gathered much attention as they can lead to out-of-equilibrium cooperative states such as flocking. Inspired by nature, where active living cells coexist with lifeless objects and structures, here we study the effective interactions that appear in systems composed of active and passive mixtures of colloids. Our systems are 2D colloidal monolayers composed primarily of passive (inactive) colloids, and a very small fraction of active (spinning) ferromagnetic colloids. We find an emergent ultra–long-range attractive interaction induced by the activity of the spinning particles and mediated by the elasticity of the passive medium. Interestingly, the appearance of such interaction depends on the spinning protocol and has a minimum actuation timescale below which no attraction is observed. Overall, these results clearly show that, in the presence of elastic components, active particles can interact across very long distances without any chemical modification of the environment. Such a mechanism might potentially be important for some biological systems and can be harnessed for newer developments in synthetic active soft materials. PMID:27071096

ESA activities on satellite laser ranging to non-cooperative objects

NASA Astrophysics Data System (ADS)

Flohrer, Tim; Krag, Holger; Funke, Quirin; Jilete, Beatriz; Mancas, Alexandru

2016-07-01

Satellite laser ranging (SLR) to non-cooperative objects is an emerging technology that can contribute significantly to operational, modelling and mitigation needs set by the space debris population. ESA is conducting various research and development activities in SLR to non-cooperative objects. ESA's Space Situational Awareness (SSA) program supports specific activities in the Space Surveillance and Tracking (SST) segment. Research and development activities with operational aspects are run by ESA's Space Debris Office. At ESA SSA/SST comprises detecting, cataloguing and predicting the objects orbiting the Earth, and the derived applications. SST aims at facilitating research and development of sensor and data processing technologies and of related common components while staying complementary with, and in support of, national and multi-national European initiatives. SST promotes standardisation and interoperability of the technology developments. For SLR these goals are implemented through researching, developing, and deploying an expert centre. This centre shall coordinate the contribution of system-external loosely connected SLR sensors, and shall provide back calibration and expert evaluation support to the sensors. The Space Debris Office at ESA is responsible for all aspects related to space debris in the Agency. It is in charge of providing operational support to ESA and third party missions. Currently, the office studies the potential benefits of laser ranging to space debris objects to resolve close approaches to active satellites, to improve re-entry predictions of time and locations, and the more general SLR support during contingency situations. The office studies the determination of attitude and attitude motion of uncooperative objects with special focus on the combination of SLR, light-curve, and radar imaging data. Generating sufficiently precise information to allow for the acquisition of debris objects by a SLR sensor in a stare

Amorphous In–Ga–Zn–O Powder with High Gas Selectivity towards Wide Range Concentration of C2H5OH

PubMed Central

Chen, Hongxiang; Jiang, Wei; Zhu, Lianfeng; Yao, Youwei

2017-01-01

Amorphous indium gallium zinc oxide (a-IGZO) powder was prepared by typical solution-based process and post-annealing process. The sample was used as sensor for detecting C2H5OH, H2, and CO. Gas-sensing performance was found to be highly sensitive to C2H5OH gas in a wide range of concentration (0.5–1250 ppm) with the response of 2.0 towards 0.5 ppm and 89.2 towards 1250 ppm. Obvious difference of response towards C2H5OH, H2, and CO was found that the response e.g., was 33.20, 6.64, and 2.84 respectively at the concentration of 200 ppm. The response time and recovery time of was 32 s and 14 s respectively towards 200 ppm concentration of C2H5OH gas under heating voltage of 6.5 V. PMID:28538686

Total RNA concentration as an index of microbial activity and oxygen supply in an oxidation ditch.

PubMed

Kanazawa, Nobuhiro; Urushigawa, Yoshikuni; Yato, Yumio

2005-06-01

Total RNA and chromosomal DNA concentrations at a municipal wastewater treatment plant with an oxidation ditch (OD) were monitored for 1.5 years using commercial extraction kits for DNA and RNA. No parameters correlated with the chromosomal DNA concentration. The total RNA concentration exhibited better correlation than the solids retention time and the mixed liquor suspended solids with the removal rate of total organic carbon, and can be regarded as an index of microbial activity. The total RNA concentration varied with a cycle of one year and increased at lower water temperatures in this OD. When diffusion theory was taken into account, it was found that the oxygen dissolution rate increased at lower temperature, and a small change in the oxygen dissolution rate caused a large variation in microbial activity and also affected nitrification and denitrification. The information was insufficient to clarify the various reaction relationships, but total RNA concentration will likely be useful as an index of microbial activity in actual wastewater treatment reactors.

Positron emission mammography (PEM): Effect of activity concentration, object size, and object contrast on phantom lesion detection

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

MacDonald, Lawrence R.; Wang, Carolyn L.; Eissa, Marna

2012-10-15

Purpose: To characterize the relationship between lesion detection sensitivity and injected activity as a function of lesion size and contrast on the PEM (positron emission mammography) Flex Solo II scanner using phantom experiments. Methods: Phantom lesions (spheres 4, 8, 12, 16, and 20 mm diameter) were randomly located in uniform background. Sphere activity concentrations were 3 to 21 times the background activity concentration (BGc). BGc was a surrogate for injected activity; BGc ranged from 0.44-4.1 kBq/mL, corresponding to 46-400 MBq injections. Seven radiologists read 108 images containing zero, one, or two spheres. Readers used a 5-point confidence scale to scoremore » the presence of spheres. Results: Sensitivity was 100% for lesions {>=}12 mm under all conditions except for one 12 mm sphere with the lowest contrast and lowest BGc (60% sensitivity). Sensitivity was 100% for 8 mm spheres when either contrast or BGc was high, and 100% for 4 mm spheres only when both contrast and BGc were highest. Sphere contrast recovery coefficients (CRC) were 49%, 34%, 26%, 14%, and 2.8% for the largest to smallest spheres. Cumulative specificity was 98%. Conclusions: Phantom lesion detection sensitivity depends more on sphere size and contrast than on BGc. Detection sensitivity remained {>=}90% for injected activities as low as 100 MBq, for lesions {>=}8 mm. Low CRC in 4 mm objects results in moderate detection sensitivity even for 400 MBq injected activity, making it impractical to optimize injected activity for such lesions. Low CRC indicates that when lesions <8 mm are observed on PEM images they are highly tracer avid with greater potential of clinical significance. High specificity (98%) suggests that image statistical noise does not lead to false positive findings. These results apply to the 85 mm thick object used to obtain them; lesion detectability should be better (worse) for thinner (thicker) objects based on the reduced (increased) influence of photon

Self-Powered Active Sensor with Concentric Topography of Piezoelectric Fibers.

PubMed

Fuh, Yiin Kuen; Huang, Zih Ming; Wang, Bo Sheng; Li, Shan Chien

2017-12-01

In this study, we demonstrated a flexible and self-powered sensor based on piezoelectric fibers in the diameter range of nano- and micro-scales. Our work is distinctively different from previous electrospinning research; we fabricated this apparatus precisely via near-field electrospinning which has a spectacular performance to harvest mechanical deformation in arbitrary direction and a novel concentrically circular topography. There are many piezoelectric devices based on electrospinning polymeric fibers. However, the fibers were mostly patterned in parallel lines and they could be actuated in limited direction only. To overcome this predicament, we re-arranged the parallel alignment into concentric circle pattern which made it possible to collect the mechanical energy whenever the deformation is along same axis or not. Despite the change of topography, the output voltage and current could still reach to 5 V and 400 nA, respectively, despite the mechanical deformation was from different direction. This new arbitrarily directional piezoelectric generator with concentrically circular topography (PGCT) allowed the piezoelectric device to harvest more mechanical energy than the one-directional alignment fiber-based devices, and this PGCT could perform even better output which promised more versatile and efficient using as a wearable electronics or sensor.

Bone mineral density across a range of physical activity volumes: NHANES 2007-2010.

PubMed

Whitfield, Geoffrey P; Kohrt, Wendy M; Pettee Gabriel, Kelley K; Rahbar, Mohammad H; Kohl, Harold W

2015-02-01

The association between aerobic physical activity volume and bone mineral density (BMD) is not completely understood. The purpose of this study was to clarify the association between BMD and aerobic activity across a broad range of activity volumes, particularly volumes between those recommended in the 2008 Physical Activity Guidelines for Americans and those of trained endurance athletes. Data from the 2007-2010 National Health and Nutrition Examination Survey were used to quantify the association between reported physical activity and BMD at the lumbar spine and proximal femur across the entire range of activity volumes reported by US adults. Participants were categorized into multiples of the minimum guideline-recommended volume based on reported moderate- and vigorous-intensity leisure activity. Lumbar and proximal femur BMD were assessed with dual-energy x-ray absorptiometry. Among women, multivariable-adjusted linear regression analyses revealed no significant differences in lumbar BMD across activity categories, whereas proximal femur BMD was significantly higher among those who exceeded the guidelines by 2-4 times than those who reported no activity. Among men, multivariable-adjusted BMD at both sites neared its highest values among those who exceeded the guidelines by at least 4 times and was not progressively higher with additional activity. Logistic regression estimating the odds of low BMD generally echoed the linear regression results. The association between physical activity volume and BMD is complex. Among women, exceeding guidelines by 2-4 times may be important for maximizing BMD at the proximal femur, whereas among men, exceeding guidelines by ≥4 times may be beneficial for lumbar and proximal femur BMD.

A Highly Linear and Wide Input Range Four-Quadrant CMOS Analog Multiplier Using Active Feedback

NASA Astrophysics Data System (ADS)

Huang, Zhangcai; Jiang, Minglu; Inoue, Yasuaki

Analog multipliers are one of the most important building blocks in analog signal processing circuits. The performance with high linearity and wide input range is usually required for analog four-quadrant multipliers in most applications. Therefore, a highly linear and wide input range four-quadrant CMOS analog multiplier using active feedback is proposed in this paper. Firstly, a novel configuration of four-quadrant multiplier cell is presented. Its input dynamic range and linearity are improved significantly by adding two resistors compared with the conventional structure. Then based on the proposed multiplier cell configuration, a four-quadrant CMOS analog multiplier with active feedback technique is implemented by two operational amplifiers. Because of both the proposed multiplier cell and active feedback technique, the proposed multiplier achieves a much wider input range with higher linearity than conventional structures. The proposed multiplier was fabricated by a 0.6µm CMOS process. Experimental results show that the input range of the proposed multiplier can be up to 5.6Vpp with 0.159% linearity error on VX and 4.8Vpp with 0.51% linearity error on VY for ±2.5V power supply voltages, respectively.

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

Code of Federal Regulations, 2010 CFR

2010-07-01

... Measurements Required, and Maximum Discrepancy Specification 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..., June 22, 2010, table C-1 to subpart C was revised, effective Aug. 23, 2010. For the convenience of the...

Doppler and range determination for deep space vehicles using active optical transponders.

PubMed

Kinman, P W; Gagliardi, R M

1988-11-01

This paper describes and analyzes two types of laser system employing active transponders that could accurately determine Doppler and range to deep space vehicles from earth-orbiting satellites. The first is a noncoherent optical system in which the Doppler effect on an intensity-modulating subcarrier is measured. The second is a coherent optical system in which the Doppler effect of the optical carrier itself is measured. Doppler and range measurement errors are mathematically modeled and, for three example systems, numerically evaluated.

Doppler and range determination for deep space vehicles using active optical transponders

NASA Technical Reports Server (NTRS)

Kinman, Peter W.; Gagliardi, Robert M.

1988-01-01

This paper describes and analyzes two types of laser system employing active transponders that could accurately determine Doppler and range to deep space vehicles from earth-orbiting satellites. The first is a noncoherent optical system in which the Doppler effect on an intensity-modulating subcarrier is measured. The second is a coherent optical system in which the Doppler effect of the optical carrier itself is measured. Doppler and range measurement errors are mathematically modeled and, for three example systems, numerically evaluated.

Vitamin D status and antimicrobial peptide cathelicidin (LL-37) concentrations in patients with active pulmonary tuberculosis.

PubMed

Yamshchikov, Alexandra V; Kurbatova, Ekaterina V; Kumari, Meena; Blumberg, Henry M; Ziegler, Thomas R; Ray, Susan M; Tangpricha, Vin

2010-09-01

Vitamin D insufficiency is common in industrialized and developing nations. Recent studies have shown that vitamin D insufficiency is associated with a higher risk of active tuberculosis. Laboratory studies provided a mechanism for this link on the basis of findings that vitamin D metabolites regulate the expression of cathelicidin (LL-37), which is an endogenous antimicrobial peptide with activity against Mycobacterium tuberculosis. Little information is available on the clinical relation between vitamin D, LL-37 concentrations, and disease severity in patients with tuberculosis. The primary objective of the study was to evaluate the relation between vitamin D nutriture, serum LL-37 concentrations, and tuberculosis by using samples stored in the Tuberculosis Trials Consortium serum repository. We measured 25-hydroxyvitamin D [25(OH)D] and LL-37 concentrations in 95 serum specimens from patients with culture-confirmed pulmonary tuberculosis and correlated these concentrations to clinical and demographic variables. The prevalence of vitamin D insufficiency [serum 25(OH)D concentration lt 30 ng/mL] in patients with active tuberculosis was 86% (n = 95) with a mean baseline serum 25(OH)D concentration of 20.4 ng/mL. Factors associated with vitamin D insufficiency were black race and indoor lifestyle. The mean ( plusmn SD) baseline LL-37 concentration was 49.5 plusmn 23.8 ng/mL. Higher LL-37 concentrations correlated with acid fast bacilli sputum smear positivity and weight gt 10% below ideal body weight. Serum vitamin D status of the study subjects did not correlate with serum LL-37 concentrations. More prospectively designed studies are needed to evaluate the clinical implications of vitamin D insufficiency in patients with tuberculosis and the utility of circulating LL-37 as a potential biomarker in patients with active tuberculosis disease. The parent trial was registered at clinicaltrials.gov as NCT00023335.

Plyometric training improves voluntary activation and strength during isometric, concentric and eccentric contractions.

PubMed

Behrens, Martin; Mau-Moeller, Anett; Mueller, Karoline; Heise, Sandra; Gube, Martin; Beuster, Nico; Herlyn, Philipp K E; Fischer, Dagmar-C; Bruhn, Sven

2016-02-01

This study investigated effects of plyometric training (6 weeks, 3 sessions/week) on maximum voluntary contraction (MVC) strength and neural activation of the knee extensors during isometric, concentric and eccentric contractions. Twenty-seven participants were randomly assigned to the intervention or control group. Maximum voluntary torques (MVT) during the different types of contraction were measured at 110° knee flexion (180°=full extension). The interpolated twitch technique was applied at the same knee joint angle during isometric, concentric and eccentric contractions to measure voluntary activation. In addition, normalized root mean square of the EMG signal at MVT was calculated. The twitch torque signal induced by electrical nerve stimulation at rest was used to evaluate training-related changes at the muscle level. In addition, jump height in countermovement jump was measured. After training, MVT increased by 20Nm (95% CI: 5-36Nm, P=0.012), 24Nm (95% CI: 9-40Nm, P=0.004) and 27Nm (95% CI: 7-48Nm, P=0.013) for isometric, concentric and eccentric MVCs compared to controls, respectively. The strength enhancements were associated with increases in voluntary activation during isometric, concentric and eccentric MVCs by 7.8% (95% CI: 1.8-13.9%, P=0.013), 7.0% (95% CI: 0.4-13.5%, P=0.039) and 8.6% (95% CI: 3.0-14.2%, P=0.005), respectively. Changes in the twitch torque signal of the resting muscle, induced by supramaximal electrical stimulation of the femoral nerve, were not observed, indicating no alterations at the muscle level, whereas jump height was increased. Given the fact that the training exercises consisted of eccentric muscle actions followed by concentric contractions, it is in particular relevant that the plyometric training increased MVC strength and neural activation of the quadriceps muscle regardless of the contraction mode. Copyright © 2015 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

The active titration method for measuring local hydroxyl radical concentration

NASA Technical Reports Server (NTRS)

Sprengnether, Michele; Prinn, Ronald G.

1994-01-01

We are developing a method for measuring ambient OH by monitoring its rate of reaction with a chemical species. Our technique involves the local, instantaneous release of a mixture of saturated cyclic hydrocarbons (titrants) and perfluorocarbons (dispersants). These species must not normally be present in ambient air above the part per trillion concentration. We then track the mixture downwind using a real-time portable ECD tracer instrument. We collect air samples in canisters every few minutes for roughly one hour. We then return to the laboratory and analyze our air samples to determine the ratios of the titrant to dispersant concentrations. The trends in these ratios give us the ambient OH concentration from the relation: dlnR/dt = -k(OH). A successful measurement of OH requires that the trends in these ratios be measureable. We must not perturb ambient OH concentrations. The titrant to dispersant ratio must be spatially invariant. Finally, heterogeneous reactions of our titrant and dispersant species must be negligible relative to the titrant reaction with OH. We have conducted laboratory studies of our ability to measure the titrant to dispersant ratios as a function of concentration down to the few part per trillion concentration. We have subsequently used these results in a gaussian puff model to estimate our expected uncertainty in a field measurement of OH. Our results indicate that under a range of atmospheric conditions we expect to be able to measure OH with a sensitivity of 3x10(exp 5) cm(exp -3). In our most optimistic scenarios, we obtain a sensitivity of 1x10(exp 5) cm(exp -3). These sensitivity values reflect our anticipated ability to measure the ratio trends. However, because we are also using a rate constant to obtain our (OH) from this ratio trend, our accuracy cannot be better than that of the rate constant, which we expect to be about 20 percent.

Real-solution stability diagrams: A thermodynamic tool for modeling corrosion in wide temperature and concentration ranges

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

Anderko, A.; Sanders, S.J.; Young, R.D.

1997-01-01

A method was developed for construction of stability diagrams for metals in the presence of realistically modeled aqueous solutions. The method was based on a comprehensive thermodynamic model that combines the Helgeson-Kirkham-Flowers (HKF) equation of state for standard-state properties with a solution nonideality model based on the activity coefficient expressions developed by Bromley and Pitzer. Composition-dependent nonideality effects were incorporated into the calculation of predominance areas for dissolved and solid species. Using the combined thermodynamic model, stability diagrams can be computed for systems involving concentrated solutions (i.e., with molalities up to 30 mol/kg) at temperatures up to 573 K andmore » pressures up to 100 MPa. Since the diagrams are based on a realistic thermodynamic model for the aqueous phase, they are referred to as real-solution stability diagrams. In addition to customary potential (E) and pH variables, concentrations of various active species (e.g., complexing agents) can be used as independent variables, making it possible to analyze effects of various compounds that promote or inhibit corrosion. Usefulness of the methodology was demonstrated by generating real-solution stability diagrams for five representative systems (i.e., sulfur-water [S-H{sub 2}O], copper-ammonia-water [Cu-NH{sub 3}-H{sub 2}O], titanium-chlorine-calcium-water [Ti-Cl-Ca-H{sub 2}O], iron-sulfur-water [Fe-S-H{sub 2}O], and zinc-water [Zn-H{sub 2}O]).« less

Evaluation of the impact of long-range transport and aerosol concentration temporal variations at the eastern coast of the Baltic Sea.

PubMed

Ovadnevaite, J; Kvietkus, K; Sakalys, J

2007-09-01

Ambient particles vary greatly in their ability to affect visibility, climate and human health. The fine fraction of aerosol is responsible for greater and wider effects on human health; thus, investigation of this fraction is very important. Continuous measurements of PM2.5 (particulate matter below 2.5 microm in size) concentrations at the Preila monitoring station started in 2003. During a period of 2 years, the episodes of high daily and semi-hourly concentrations of PM2.5 were measured. These episodes did not depend on the season or time of day. The substantial role of long-range transport of pollutants to these increases in concentration was shown using chemical and statistical analysis. It was found that most of the severe episodes occurred when air masses came from a specific site besides it was established that air masses of different origin were characterized by different mixing layer depth. Lower mixing depth was observed in air masses characterized by higher observed concentrations at the measuring site and vice versa. PM2.5 concentrations showed diurnal and seasonal variations whose pattern reflected the regional origin of the aerosol. The regional pollution level was evaluated by the statistical analysis of PM2.5 concentrations. The background annual average of PM2.5 mass concentration for the eastern coast of the Baltic Sea was 15.1 +/- 0.8 microg m(-3).

Controlling 212Bi to 212Pb activity concentration ratio in thoron chambers.

PubMed

He, Zhengzhong; Xiao, Detao; Lv, Lidan; Zhou, Qingzhi; Shan, Jian; Qiu, Shoukang; Wu, Xijun

2017-11-01

It is necessary to establish a reference atmosphere in a thoron chamber containing various ratios of 212 Bi to 212 Pb activity concentrations (C( 212 Bi)/C( 212 Pb)) to simulate typical environmental conditions (e.g., indoor or underground atmospheres). In this study, a novel method was developed for establishing and controlling C( 212 Bi)/C( 212 Pb) in a thoron chamber system based on an aging chamber and air recirculation loops which alter the ventilation rate. The effects of main factors on the C( 212 Bi)/C( 212 Pb) were explored, and a steady-state theoretical model was derived to calculate the ratio. The results show that the C( 212 Bi)/C( 212 Pb) inside the chamber is mainly dependent on ventilation rate. Ratios ranging from 0.33 to 0.83 are available under various ventilation. The stability coefficient of the ratios is better than 7%. The experimental results are close to the theoretical calculated results, which indicates that the model can serve as a guideline for the quantitative control of C( 212 Bi)/C( 212 Pb). Copyright © 2017 Elsevier Ltd. All rights reserved.

Survival-Related Autophagic Activity Versus Procalcific Death in Cultured Aortic Valve Interstitial Cells Treated With Critical Normophosphatemic-Like Phosphate Concentrations

PubMed Central

Bonetti, Antonella; Della Mora, Alberto; Contin, Magali; Gregoraci, Giorgia; Tubaro, Franco; Marchini, Maurizio; Ortolani, Fulvia

2017-01-01

Valve dystrophic calcification is a common disorder affecting normophosphatemic subjects. Here, cultured aortic valve interstitial cells (AVICs) were treated 3 to 28 days with phosphate (Pi) concentrations spanning the normal range in humans (0.8, 1.3, and 2.0 mM) alone or supplemented with proinflammatory stimuli to assess possible priming of dystrophic-like calcification. Compared with controls, spectrophotometric analyses revealed marked increases in calcium amounts and alkaline phosphatase activity for 2.0-mM-Pi-containing cultures, with enhancing by proinflammatory mediators. Ultrastructurally, AVICs treated with low/middle Pi concentrations showed an enormous endoplasmic reticulum (ER) enclosing organelle debris, so apparently executing a survival-related atypical macroautophagocytosis, consistently with ultracytochemical demonstration of ER-associated acid phosphatase activity and decreases in autophagosomes and immunodetectable MAP1LC3. In contrast, AVICs cultured at 2.0-mM Pi underwent mineralization due to intracellular release and peripheral layering of phospholipid-rich material acting as hydroxyapatite nucleator, as revealed by Cuprolinic Blue and von Kossa ultracytochemical reactions. Lack of immunoblotted caspase-3 cleaved form indicated apoptosis absence for all cultures. In conclusion, fates of cultured AVICs were crucially driven by Pi concentration, suggesting that serum Pi levels just below the upper limit of normophosphatemia in humans may represent a critical watershed between macroautophagy-associated cell restoring and procalcific cell death. PMID:28112549

Wearable Wide-Range Strain Sensors Based on Ionic Liquids and Monitoring of Human Activities

PubMed Central

Zhang, Shao-Hui; Wang, Feng-Xia; Li, Jia-Jia; Peng, Hong-Dan; Yan, Jing-Hui; Pan, Ge-Bo

2017-01-01

Wearable sensors for detection of human activities have encouraged the development of highly elastic sensors. In particular, to capture subtle and large-scale body motion, stretchable and wide-range strain sensors are highly desired, but still a challenge. Herein, a highly stretchable and transparent stain sensor based on ionic liquids and elastic polymer has been developed. The as-obtained sensor exhibits impressive stretchability with wide-range strain (from 0.1% to 400%), good bending properties and high sensitivity, whose gauge factor can reach 7.9. Importantly, the sensors show excellent biological compatibility and succeed in monitoring the diverse human activities ranging from the complex large-scale multidimensional motions to subtle signals, including wrist, finger and elbow joint bending, finger touch, breath, speech, swallow behavior and pulse wave. PMID:29135928

Activity budget and ranging patterns of Colobus vellerosus in forest fragments in central Ghana.

PubMed

Wong, Sarah N P; Sicotte, Pascale

2007-01-01

The forest fragments surrounding the 192-ha Boabeng-Fiema Monkey Sanctuary (BFMS) in central Ghana contain small populations of Colobus vellerosus. Data were collected on activity budget, ranging patterns and habitat use of 3 groups living in these small fragments in August-November 2003, and compared to 3 BFMS groups. Fragment groups spent less time moving and more time resting than BFMS groups. Home ranges of fragment groups tended to be smaller than those of BFMS groups. Fragment and BFMS groups used similarly sized trees. Comparisons of activity budget and ranging between fragments and the BFMS suggest that fragment habitat quality was sufficient to sustain current numbers. These behavioral trends are consistent with a concurrent study that we conducted investigating ecological quality in the same fragments. Copyright 2007 S. Karger AG, Basel.

Enhancement of antioxidant activity and physicochemical properties of yogurt enriched with concentrated strawberry pulp obtained by block freeze concentration.

PubMed

Jaster, Henrique; Arend, Giordana Demaman; Rezzadori, Katia; Chaves, Vitor Clasen; Reginatto, Flávio Henrique; Petrus, José Carlos Cunha

2018-02-01

Strawberry juice was concentrated using block freeze concentration process. The concentrate was used to produce two yogurts with different concentrations of cryoconcentrated strawberry pulp (15% and 30%). Total lactic acid bacteria count, physicochemical and rheological properties was evaluated during storage (7days) for all yogurts. Also, the beverages produced were compared with two commercial trademarks. It was observed that the total lactic acid bacteria count remained higher than 10 8 CFU·mL -1 during the storage time for all beverages studied. The viscosity of the yogurts decreased when the ratio of strawberry cryoconcentrate was increased. The Power Law model was successfully applied to describe the flow of the yogurts, which had a thixotropic behaviour. The incorporation of the cryoconcentrated strawberry pulp in the yogurt resulted in a product with 3-fold more anthocyanins content and antioxidant activity. The enrichment of natural yogurt with strawberry cryoconcentrated pulp proved to be effective in the production of a beverage with higher nutritional characteristics. Copyright © 2017 Elsevier Ltd. All rights reserved.

[Effects of elevated ozone concentrations on enzyme activities and organic acids content in wheat rhizospheric soil.

PubMed

Yin, Wei Qin; Jing, Hao Qi; Wang, Ya Bo; Wei, Si Yu; Sun, Yue; Wang, Sheng Sen; Wang, Xuai Zhi

2018-02-01

The elevated concentration of tropospheric ozone (O 3 ) is an important global climate change driver, with adverse impacts on soil ecological environment and crop growth. In this study, a pot experiment was carried out in an open top chamber (OTC), to investigate the effects of elevated ozone concentration on soil enzyme activities (catalase, polyphenol oxidase, dehydrogenase and invertase), organic acids contents (oxalic acid, citric acid and malic acid) at different growth stages (tillering, jointing, heading and ripening stages) of wheat, and combined with the rhizospheric soil physicochemical properties and plant root characteristics to analyze the underlying reasons. The results showed that, elevated ozone concentration increased soil catalase, polyphenol oxidase, dehydrogenase and invertase activities at wheat ripening period to different degrees, with the effects on the activities of catalase and polyphenol oxidase being statistically significant. At the heading stage, activities of dehydrogenase and invertase were significantly increased by up to 76.7%. At the ripening stage, elevated ozone concentration significantly increased the content of citric acid and malic acid and redox potential (Eh) in rhizospheric soil, but reduced soil pH, electrical conductivity, total carbon and nitrogen. For root characteristics, elevated ozone concentrations significantly reduced the wheat root biomass, total root length and root surface area but increased the average root diameter.

Dimerization in Highly Concentrated Solutions of Phosphoimidazolide Activated Mononucleotides

NASA Technical Reports Server (NTRS)

Kanavarioti, Anastassia

1997-01-01

Phosphoimidazolide activated ribomononucleotides (*pN) are useful substrates for the non-enzymatic synthesis of polynucleotides. However, dilute neutral aqueous solutions of *pN typically yield small amounts of dimers and traces of polymers; most of *pN hydrolyzes to yield nucleoside 5'-monophosphate. Here we report the self-condensation of nucleoside 5'-phosphate 2- methylimidazolide (2-MeImpN with N = cytidine, uridine or guanosine) in the presence of Mg2(+) in concentrated solutions, such as might have been found in an evaporating lagoon on prebiotic Earth. The product distribution indicates that oligomerization is favored at the expense of hydrolysis. At 1.0 M, 2-MelmpU and 2-MelmpC produce about 65% of oligomers including 4% of the 3',5'-Iinked dimer. Examination of the product distribution of the three isomeric dimers in a self-condensation allows identification of reaction pathways that lead to dimer formation. Condensations in a concentrated mixture of all three nucleotides (U,C,G mixtures) is made possible by the enhanced solubility of 2-MeImpG in such mixtures. Although percent yield of intemucleotide linked dimers is enhanced as a function of initial monomer concentration, pyrophosphate dimer yields remain practically unchanged at about 20% for 2-MelmpU, 16% for 2-MeImpC and 25% of the total pyrophosphate in the U,C,G mixtures. The efficiency by which oligomers are produced in these concentrated solutions makes the evaporating lagoon scenario a potentially interesting medium for the prebiotic synthesis of dimers and short RNAs.

Dimerization in Highly Concentrated Solutions of Phosphoimidazolide Activated Monomucleotides

NASA Astrophysics Data System (ADS)

Kanavarioti, Anastassia

1997-08-01

Phosphoimidazolide activated ribomononucleotides (*pN) are useful substrates for the non-enzymatic synthesis of polynucleotides. However, dilute neutral aqueous solutions of *pN typically yield small amounts of dimers and traces of polymers; most of *pN hydrolyzes to yield nucleoside 5'-monophosphate. Here we report the self-condensation of nucleoside 5'-phosphate 2-methylimidazolide (2-MeImpN with N = cytidine, uridine or guanosine) in the presence of Mg2+ in concentrated solutions, such as might have been found in an evaporating lagoon on prebiotic Earth. The product distribution indicates that oligomerization is favored at the expense of hydrolysis. At 1.0 M, 2-MeImpU and 2-MeImpC produce about 65% of oligomers including 4% of the 3',5'-linked dimer. Examination of the product distribution of the three isomeric dimers in a self-condensation allows identification of reaction pathways that lead to dimer formation. Condensations in a concentrated mixture of all three nucleotides (U,C,G mixtures) is made possible by the enhanced solubility of 2-MeImpG in such mixtures. Although percent yield of internucleotide linked dimers is enhanced as a function of initial monomer concentration, pyrophosphate dimer yields remain practically unchanged at about 20% for 2-MeImpU, 16% for 2-MeImpC and 25% of the total pyrophosphate in the U,C,G mixtures. The efficiency by which oligomers are produced in these concentrated solutions makes the evaporating lagoon scenario a potentially interesting medium for the prebiotic synthesis of dimers and short RNAs.

Short-term 222Rn activity concentration changes in underground spaces with limited air exchange with the atmosphere

NASA Astrophysics Data System (ADS)

Fijałkowska-Lichwa, L.; Przylibski, T. A.

2011-04-01

The authors investigated short-time changes in 222Rn activity concentration occurring yearly in two underground tourist facilities with limited air exchange with the atmosphere. One of them is Niedźwiedzia (Bear) Cave in Kletno, Poland - a natural space equipped with locks ensuring isolation from the atmosphere. The other site is Fluorite Adit in Kletno, a section of a disused uranium mine. This adit is equipped with a mechanical ventilation system, operated periodically outside the opening times (at night). Both sites are situated within the same metamorphic rock complex, at similar altitudes, about 2 km apart. The measurements conducted revealed spring and autumn occurrence of convective air movements. In Bear Cave, this process causes a reduction in 222Rn activity concentration in the daytime, i.e. when tourists, guides and other staff are present in the cave. From the point of view of radiation protection, this is the best situation. For the rest of the year, daily concentrations of 222Rn activity in the cave are very stable. In Fluorite Adit, on the other hand, significant variations in daily 222Rn activity concentrations are recorded almost all year round. These changes are determined by the periods of activity and inactivity of mechanical ventilation. Unfortunately this is inactive in the daytime, which results in the highest values of 222Rn activity concentration at the times when tourists and staff are present in the adit. Slightly lower concentrations of radon in Fluorite Adit are recorded in the winter season, when convective air movements carry a substantial amount of radon out into the atmosphere. The incorrect usage of mechanical ventilation in Fluorite Adit results in the most unfavourable conditions in terms of radiation protection. The staff working in that facility are exposed practically throughout the year to the highest 222Rn activity concentrations, both at work (in the adit) and at home (outside their working hours). Therefore, not very well

Different cortical activation patterns during voluntary eccentric and concentric muscle contractions: an fMRI study.

PubMed

Kwon, Yong-Hyun; Park, Ji-Won

2011-01-01

Concentric and eccentric muscle contractions have distinct differences in their neuromuscular and neurophysiologic characteristics. However, although many evidences regarding the features of these types of muscle contraction have emerged, there have been few neuroimaging studies to compare the two types of contractions. Therefore, we investigated whether cortical activity associated with eccentric contraction of the wrist extensors differed from that of concentric contraction, using functional MRI (fMRI). Fifteen right-handed healthy subjects were enrolled in this study. During 4 repeating blocks of eccentric and concentric muscle contraction paradigms, the brain was scanned with fMRI. The differences in the BOLD signal intensities during the performance of eccentric and concentric exercise were compared in the predetermined regions of interest. Our findings revealed that many cortical areas associated with motor performance were activated, including the primary motor area, the inferior parietal lobe, the pre-supplementary area (pre-SMA), the anterior cingulate cortex, the prefrontal area, and the cerebellum. In addition, lower signal intensities were seen in the right primary motor cortex and right cerebellum during eccentric contractions compared with concentric contractions, whereas higher signal intensities were detected in other cortical areas during eccentric contractions. In the study, we demonstrated that eccentric and concentric muscle contractions induced quite different patterns of cortical activity respectively. These findings might be attributed to different strategy of neuro-motor processing and a higher level of cognitive demand for the performance of motor task with a higher degree of difficulty such as that required during eccentric contractions in comparison of concentric contractions.

Effects of ethylenediurea on snap bean at a range of ozone concentrations

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

Miller, J.E.; Pursley, W.A.; Heagle, A.S.

Ethylenediurea (EDU) [N-[2-(2-Oxo-1-imidazolidinyl) ethyl]-N{prime}-phenylurea] often protects plants from visible foliar injury due ozone{sub 3}. A few studies have indicated that EDU can suppress plant growth and yield. Because of the potential value of EDU as a research and assessment tool, controlled field experiments with snap bean Phaseolus vulgaris L. ({open_quotes}BBL-290{close_quotes}) were performed to test the effectiveness of different EDU application rates used in open-top chambers in each of two experiments [charcoal-filtered (CF) air, nonfiltered (NF) air, and nominal O{sub 3} additions of 0.025 and 0.05 or 0.03 and 0.06 {mu}LL{sup -1}O{sub 3} to NF air]. Ethylenediurea was added biweekly tomore » the potting medium . The EDU treatment concentration were 0, 14, 28, 56, and 120 and 0, 8, 16, and 32 mg EDU (active) L{sup -1} of potting medium in experiments one and two, respectively. Ethylenediurea provided some protection against O{sub 3}-induced foliar injury and growth suppression in both experiments. Measurements of net carbon exchange rate (NCER) and carbohydrate status of the tissues reflected the protective effects of EDU. In the first experiment EDU caused visible foliar injury at some growth stages and suppressed growth. In the second experiment, visible foliar injury was not caused by EDU at any concentration, but pod biomass (yield) was suppressed by EDU in CF chambers. The differences may have been due to environmental conditions (i.e., hot and dry during the first experiment and cooler during the second). Ethylenediurea also affected biomass partitioning in the plants grown in CF air (relative biomass was increased in leaves and decreased in pods). The results indicate that although EDU does protect or partially protect snap bean against O{sub 3} injury, it may also affect physiology and growth. 27 refs., 6 tabs.« less

Activity concentrations and dose rates from decorative granite countertops.

PubMed

Llope, W J

2011-06-01

The gamma radiation emitted from a variety of commercial decorative granites available for use in U.S. homes has been measured with portable survey meters as well as an NaI(Th) gamma spectrometer. The (40)K, U-nat, and (232)Th activity concentrations were determined using a full-spectrum analysis. The dose rates that would result from two different arrangements of decorative granite slabs as countertops were explored in simulations involving an adult anthropomorphic phantom. Copyright © 2011 Elsevier Ltd. All rights reserved.

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

Relative phase asynchrony and long-range correlation of long-term solar magnetic activity

NASA Astrophysics Data System (ADS)

Deng, Linhua

2017-07-01

Statistical signal processing is one of the most important tasks in a large amount of areas of scientific studies, such as astrophysics, geophysics, and space physics. Phase recurrence analysis and long-range persistence are the two dynamical structures of the underlying processes for the given natural phenomenon. Linear and nonlinear time series analysis approaches (cross-correlation analysis, cross-recurrence plot, wavelet coherent transform, and Hurst analysis) are combined to investigate the relative phase interconnection and long-range correlation between solar activity and geomagnetic activity for the time interval from 1932 January to 2017 January. The following prominent results are found: (1) geomagnetic activity lags behind sunspot numbers with a phase shift of 21 months, and they have a high level of asynchronous behavior; (2) their relative phase interconnections are in phase for the periodic scales during 8-16 years, but have a mixing behavior for the periodic belts below 8 years; (3) both sunspot numbers and geomagnetic activity can not be regarded as a stochastic phenomenon because their dynamical behaviors display a long-term correlation and a fractal nature. We believe that the presented conclusions could provide further information on understanding the dynamical coupling of solar dynamo process with geomagnetic activity variation, and the crucial role of solar and geomagnetic activity in the long-term climate change.

Glacial reorganization of topography in a tectonically active mountain range

NASA Astrophysics Data System (ADS)

Adams, Byron; Ehlers, Todd

2016-04-01

Tests of the interactions between tectonic and climate forcing on Earth's topography often focus on the concept of steady-state whereby processes of rock deformation and erosion are opposing and equal. However, when conditions change such as the climate or tectonic rock uplift, then surface processes act to restore the balance between rock deformation and erosion by adjusting topography. Most examples of canonical steady-state mountain ranges lie within the northern hemisphere, which underwent a radical change in the Quaternary due to the onset of widespread glaciation. The activity of glaciers changed erosion rates and topography in many of these mountain ranges, which likely violates steady-state assumptions. With new topographic analysis, and existing patterns of climate and rock uplift, we explore a mountain range previously considered to be in steady-state, the Olympic Mountains, USA. The details of our analysis suggest the dominant topographic signal in the Olympic Mountains is a spatial, and likely temporal, variation in erosional efficiency dictated by orographic precipitation, and Pleistocene glacier ELA patterns, and not tectonic rock uplift rates. Alpine glaciers drastically altered the relief structure of the Olympic Mountains. The details of these relief changes are recorded in channel profiles as overdeepenings, reduced slopes, and associated knickpoints. We find the position of these relief changes within the orogen is dependent on the position of the Pleistocene ELA. While alpine glaciers overdeepened valleys in regions near the Pleistocene ELA (which has a tendency to increase relief), headward erosion of west and north flowing glacier systems captured significant area from opposing systems and caused drainage divide lowering. This divide lowering reduced relief throughout the range. We demonstrate similar topographic effects recorded in the basin hypsometries of other Cenozoic mountain ranges around the world. The significant glacial overprint on

Generic Long-Range Interactions Between Passive Bodies in an Active Fluid.

PubMed

Baek, Yongjoo; Solon, Alexandre P; Xu, Xinpeng; Nikola, Nikolai; Kafri, Yariv

2018-02-02

A single nonspherical body placed in an active fluid generates currents via breaking of time-reversal symmetry. We show that, when two or more passive bodies are placed in an active fluid, these currents lead to long-range interactions. Using a multipole expansion, we characterize their leading-order behaviors in terms of single-body properties and show that they decay as a power law with the distance between the bodies, are anisotropic, and do not obey an action-reaction principle. The interactions lead to rich dynamics of the bodies, illustrated by the spontaneous synchronized rotation of pinned nonchiral bodies and the formation of traveling bound pairs. The occurrence of these phenomena depends on tunable properties of the bodies, thus opening new possibilities for self-assembly mediated by active fluids.

Long-range electrostatic complementarity governs substrate recognition by human chymotrypsin C, a key regulator of digestive enzyme activation.

PubMed

Batra, Jyotica; Szabó, András; Caulfield, Thomas R; Soares, Alexei S; Sahin-Tóth, Miklós; Radisky, Evette S

2013-04-05

Human chymotrypsin C (CTRC) is a pancreatic serine protease that regulates activation and degradation of trypsinogens and procarboxypeptidases by targeting specific cleavage sites within their zymogen precursors. In cleaving these regulatory sites, which are characterized by multiple flanking acidic residues, CTRC shows substrate specificity that is distinct from that of other isoforms of chymotrypsin and elastase. Here, we report the first crystal structure of active CTRC, determined at 1.9-Å resolution, revealing the structural basis for binding specificity. The structure shows human CTRC bound to the small protein protease inhibitor eglin c, which binds in a substrate-like manner filling the S6-S5' subsites of the substrate binding cleft. Significant binding affinity derives from burial of preferred hydrophobic residues at the P1, P4, and P2' positions of CTRC, although acidic P2' residues can also be accommodated by formation of an interfacial salt bridge. Acidic residues may also be specifically accommodated in the P6 position. The most unique structural feature of CTRC is a ring of intense positive electrostatic surface potential surrounding the primarily hydrophobic substrate binding site. Our results indicate that long-range electrostatic attraction toward substrates of concentrated negative charge governs substrate discrimination, which explains CTRC selectivity in regulating active digestive enzyme levels.

Measurements of radon concentrations in Spa waters in Amasya, Turkey

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

Yigitoglu, I., E-mail: ibrahim.yigitoglu@gop.edu.tr; Ucar, B.; Oner, F.

The aim of this study is to determine the radon concentrations in thermal waters in the Amasya basin in Turkey and to explore the relationship between radon anomalies and active geological faults. The radon concentration measurements were performed in four thermal Spas around Amasya basin. The water samples were collected from tap waters in thermal water sources. The obtained radon concentrations ranged from 0.15 ± 0.12 to 0.71 ± 0.32 BqL{sup −1} for Spa waters. The relationship between the radon concentration anomalies and earthquakes that occurred in the sampling period are discussed.

Mercury Inhibits Soil Enzyme Activity in a Lower Concentration than the Guideline Value.

PubMed

Mahbub, Khandaker Rayhan; Krishnan, Kannan; Megharaj, Mallavarapu; Naidu, Ravi

2016-01-01

Three soil types - neutral, alkaline and acidic were experimentally contaminated with nine different concentrations of inorganic mercury (0, 5, 10, 50, 100, 150, 200, 250, 300 mg/kg) to derive effective concentrations of mercury that exert toxicity on soil quality. Bioavailability of mercury in terms of water solubility was lower in acidic soil with higher organic carbon. Dehydrogenase enzyme activity and nitrification rate were chosen as indicators to assess soil quality. Inorganic mercury significantly inhibited (p < 0.001) microbial activities in the soils. The critical mercury contents (EC10) were found to be less than the available safe limits for inorganic mercury which demonstrated inadequacy of existing guideline values.

Selenium concentrations and enzyme activities of glutathione metabolism in wild long-tailed ducks and common eiders

USGS Publications Warehouse

Franson, J. Christian; Hoffman, David J.; Flint, Paul L.

2011-01-01

The relationships of selenium (Se) concentrations in whole blood with plasma activities of total glutathione peroxidase, Se-dependent glutathione peroxidase, and glutathione reductase were studied in long-tailed ducks (Clangula hyemalis) and common eiders (Somateria mollissima) sampled along the Beaufort Sea coast of Alaska, USA. Blood Se concentrations were >8 μg/g wet weight in both species. Linear regression revealed that the activities of total and Se-dependent glutathione peroxidase were significantly related to Se concentrations only in long-tailed ducks, raising the possibility that these birds were experiencing early oxidative stress.

Anti-Salmonella activity of medicinal plants from Cameroon.

PubMed

Nkuo-Akenji, T; Ndip, R; McThomas, A; Fru, E C

2001-06-01

To evaluate the effects of herbal extracts derived from plants commonly prescribed by traditional practitioners for the treatment of typhoid fever. A cross sectional study. Departments of Life Sciences and Chemistry, University of Buea, Cameroon. Methanol extracts of plant parts commonly used in Cameroon for the treatment of typhoid fever. Antimicrobial activity was tested using the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) assays. Methanol extracts of plant parts commonly used in Cameroon for the treatment of typhoid fever were tested for antibacterial activity against Salmonella typhi, S. paratyphi and S. typhimurium. The formulations used were: 1) Formulation A comprising Cymbogogon citratus leaves, Carica papaya leaves, and Zea mays silk. 2) Formulation B comprising C. papaya roots, Mangifera indica leaves, Citrus limon fruit and C. citratus leaves. 3) C. papaya leaves. 4) Emilia coccinea whole plant. 5) Comelina bengalensis leaves. 6) Telfaria occidentalis leaves. 7) Gossypium arboreum whole plant. Antimicrobial activity was tested using the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) assays. Generally, Formulation A elicited inhibitory activity at a lower range of 0.02 to 0.06 mg/ml. Similarly, Formulation B elicited bacterial activity at the lowest range of 0.06 to 0.25 mg/ml. C. bengalensis leaves on the other hand, showed the lowest activity with a concentration range of 0.132 to 2.0 mg/ml and 1 to 4 mg/ml in MIC and MBC assays respectively. S. paratyphi was most sensitive to the formulations (concentration range of 0.02 to 1 mg/ml in both MIC and MBC assays) while S. typhimurium was the least sensitive and concentrations of up to 4 mg/ml were required to be bactericidal. It is concluded that plant extracts with low MIC and MBC values (1 mg/ml and lower) may contain compounds with therapeutic activity.

Optical Sensor for Diverse Organic Vapors at ppm Concentration Ranges

PubMed Central

Thomas, J. Christopher; Trend, John E.; Rakow, Neal A.; Wendland, Michael S.; Poirier, Richard J.; Paolucci, Dora M.

2011-01-01

A broadly responsive optical organic vapor sensor is described that responds to low concentrations of organic vapors without significant interference from water vapor. Responses to several classes of organic vapors are highlighted, and trends within classes are presented. The relationship between molecular properties (vapor pressure, boiling point, polarizability, and refractive index) and sensor response are discussed. PMID:22163798

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

PubMed

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

2010-02-01

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

Does proprioceptive acuity during active knee rotation in the transverse plane vary at different ranges?

PubMed

Muaidi, Qassim I

2016-11-21

Knee proprioception in the sagittal plane has been widely investigated in prospective studies, however limited information is known about proprioceptive acuity during active knee rotation and the way most commonly injured. To investigate whether proprioceptive acuity during active internal and external knee rotation varies at different ranges in the transverse plane. Healthy volunteers (N: 26) without previous injury or surgery of the knee joint participated in the study.Knee rotation proprioceptive acuity was measured using a custom-designed device. The measure of proprioceptive acuity used in this study was the just-noticeable-difference (JND). Participants actively rotated the knee at different intervals(initial, mid, and terminal internal or external rotation range) to one of four movement blocks and the magnitude of the permitted motion was judged. The means of the JND for proprioceptive acuity at initial internal rotation (0.80° ± 0.06) were significantly (p< 0.002) lower than for mid (1.62° ± 0.18), and terminal (2.08° ± 0.35) internal rotation. The means of the JND for proprioceptive acuity at initial external rotation (1.16° ± 0.10) were significantly (p< 0.04) lower than for mid (1.95° ± 0.30), and terminal (1.97° ± 0.24) internal rotation. Participants perceived smaller differences between active internal and external rotation movements at initial rotation range than at the mid and terminal rotation range of movement. This suggests better proprioceptive acuity at the initial rotation range of movement in the transverse plane.

Summary and analysis of approaches linking visual range, PM2.5 concentrations, and air quality health impact indices for wildfires.

PubMed

O'Neill, Susan M; Lahm, Peter W; Fitch, Mark J; Broughton, Mike

2013-09-01

Several U.S. state and tribal agencies and other countries have implemented a methodology developed in the arid intermountain western U.S. where short-term (1- to 3-hr) particulate matter (PM) with aerodynamic diameters less than 2.5 microm (PM2.5) concentrations are estimated from an observed visual range (VR) measurement. This PM2.5 concentration estimate is then linked to a public health warning scale to inform the public about potential health impacts from smoke from wildfire. This methodology is often used where monitoring data do not exist (such as many rural areas). This work summarizes the various approaches, highlights the potential for wildfire smoke impact messaging conflicts at state and international borders, and highlights the need to define consistent short-term health impact category breakpoint categories. Is air quality "unhealthy" when 1- to 3-hr PM2.5 is > or = 139 microg/m3 as specified in the Wildfire Smoke, A Guide for Public Health Officials? Or is air quality unhealthy when 1- to 3-hr PM2.5 is > or = 88.6 microg/m3 as specified in the Montana categorizations? This work then examines the relationship between visual range and PM2.5 concentrations using data from the Interagency Monitoring of PROtected Visual Environments (IMPROVE) program and the IMPROVE extinction coefficient (beta ext) equation to simulate an atmosphere dominated by smoke for sites in the arid intermountain western U.S. and great plains. This was accomplished by rearranging the beta ext equation to solve for organic mass as a function of VR. The results show that PM2.5 and VR are related by PM2.5 = 622 * VR(-0.98) with a correlation of 0.99 and that at low VR values (<10 km) a small change in VR results in a large change in PM2.5 concentrations. The results also show that relative humidity and the presence of hygroscopic pollutants from sources other than fire can change the VR/PM2.5 relationships, especially at PM2.5 concentrations less than approximately 90 microg/m3.

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

NASA Astrophysics Data System (ADS)

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

2015-12-01

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

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

PubMed

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

2009-06-01

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

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

Selenium concentrations in leaf material from Astragalus oxyphysus (Diablo Locoweed) and Atriplex lentiformis (quail bush) in the interior coast ranges and the western San Joaquin Valley, California

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

Izbicki, J.A.; Harms, T.F.

1986-01-01

Leaf material from selenium accumulating plants was collected and analyzed for selenium to obtain a relative indication of selenium concentrations in soils and identify sites suitable for further soil study. Selenium concentrations of 14 samples of leaf material from Astragalus oxyphysus ranged from 0.08 to 3.5 microg/g dry weight and had a median concentration of 0.25 microg/g. Five replicate samples of A. oxyphysus had a mean selenium concentration of 0.22 microg/g and a standard deviation of 0.07. Selenium concentrations of 17 samples of leaf material from Atriplex lentiformis ranged from 0.08 to 7.5 microg/g and had a median concentration ofmore » 0.35 microg/g. As a general guideline, the National Academy of Sciences recommends a maximum safe tolerance level of 2 microg/g of selenium in animal feeds. One sample of A. oxyphysus, collected in the Panoche Creek drainage, exceeded 2 microg/g. Three samples of A. lentiformis, collected in Klipstein Canyon, Tumey Fan, and Panoche Fan, equaled or exceeded 2 microg/g. These sites may be suitable. 34 refs., 5 figs., 2 tabs.« less

Investigation of radioactivity concentration in spent technetium generators

NASA Astrophysics Data System (ADS)

Idriss, Hajo; Salih, Isam; Alaamer, Abdulaziz S.; Eisa, M. H.; Sam, A. K.

2014-04-01

This study was carried out to survey and measure radioactivity concentration and estimate radiation dose level at the surface of spent technetium generator columns for the safe final disposal of radioactive waste. High resolution γ-spectrometry with the aid of handheld radiation survey meters has been used. The radioactivity measurements has shown that 238U, 40K and 137Cs were only measurable in one sample whereas 125Sb was found in 14 samples out of total of 20 samples with an activity concentration which ranged from 21 to 7404 with an average value of 1095 Bq/kg. The activity concentration of 125Sb is highly variable indicating that the spent 99mTc generator columns are of different origin. This investigation highlighted the importance of radiation monitoring of spent technetium generators in the country in order to protect workers, and the public from the dangers posed by radioactive waste.

Modeling Interactions among Individual P2 Receptors to Explain Complex Response Patterns over a Wide Range of ATP Concentrations

PubMed Central

Xing, Shu; Grol, Matthew W.; Grutter, Peter H.; Dixon, S. Jeffrey; Komarova, Svetlana V.

2016-01-01

Extracellular ATP acts on the P2X family of ligand-gated ion channels and several members of the P2Y family of G protein-coupled receptors to mediate intercellular communication among many cell types including bone-forming osteoblasts. It is known that multiple P2 receptors are expressed on osteoblasts (P2X2,5,6,7 and P2Y1,2,4,6). In the current study, we investigated complex interactions within the P2 receptor network using mathematical modeling. To characterize individual P2 receptors, we extracted data from published studies of overexpressed human and rodent (rat and mouse) receptors and fit their dependencies on ATP concentration using the Hill equation. Next, we examined responses induced by an ensemble of endogenously expressed P2 receptors. Murine osteoblastic cells (MC3T3-E1 cells) were loaded with fluo-4 and stimulated with varying concentrations of extracellular ATP. Elevations in the concentration of cytosolic free calcium ([Ca2+]i) were monitored by confocal microscopy. Dependence of the calcium response on ATP concentration exhibited a complex pattern that was not explained by the simple addition of individual receptor responses. Fitting the experimental data with a combination of Hill equations from individual receptors revealed that P2Y1 and P2X7 mediated the rise in [Ca2+]i at very low and high ATP concentrations, respectively. Interestingly, to describe responses at intermediate ATP concentrations, we had to assume that a receptor with a K1∕2 in that range (e.g. P2Y4 or P2X5) exerts an inhibitory effect. This study provides new insights into the interactions among individual P2 receptors in producing an ensemble response to extracellular ATP. PMID:27468270

Frequency and concentration windows for the electric activation of a membrane active transport system.

PubMed Central

Markin, V. S.; Tsong, T. Y.

1991-01-01

Previous work has shown that a simple four-state membrane transport system can interact with an oscillating electric field to become an active transport system if there is charge translocation associated with conformational changes of the transporter and if affinities of the transporter for the ligand on the two sides of membrane are different. The relationship between the transport flux and both the frequency of the applied field and the concentration of ligand have been examined based on the following assumptions: the rate of the electroconformational change of the transporter is much greater than that of the ligand association/dissociation reaction, and the oscillating electric field has a large amplitude. It was found that the transport flux depends strongly on the frequency of the field and on the concentration of the ligand and it displays a window of broad bandwidth both on the frequency and the concentration axes. The maximum concentration gradient, or the static head, which can be supported by this mechanism is shown to be constant for field frequencies smaller than the rate of the electroconformational change. The static head value diminishes completely when the field frequency exceeds the rate of the conformational change. The presence of an optimal field frequency has been shown experimentally in several membrane enzyme systems. The theory was applied to the description of Rb and Na pumping in human erythrocytes stimulated by an AC field. The prediction of a window for a ligand concentration and the static head value may be tested experimentally. In addition, the rate constants and the equilibrium constants of the four state model can be determined by measuring positions of windows, fluxes, and static head values under different experimental conditions. These results are equally applicable to the oscillation of pressure, membrane tension, substrate concentration, or temperature if these external parameters can induce functionally relevant conformational

Dynamics of reactive microbial hotspots in concentration gradients

NASA Astrophysics Data System (ADS)

Hubert, Antoine; Farasin, Julien; Tabuteau, Hervé; Méheust, Yves; Le Borgne, Tanguy

2017-04-01

In subsurface environments, bacteria play a major role in controlling the kinetics of a broad range of biogeochemical reactions. In such environments, nutrients fluxes and solute concentrations needed for bacteria metabolism may be highly variable in space and intermittent in time. This can lead to the formation of reactive hotspots where and when conditions are favorable to particular microorganisms, hence inducing biogeochemical reaction kinetics that differ significantly from those measured in homogeneous model environments. To investigate the impact of chemical gradients on the spatial structure and temporal dynamics of subsurface microorganism populations, we develop microfluidic cells allowing for a precise control of flow and chemical gradient conditions, as well as a quantitative monitoring of the bacteria's spatial distribution and biofilm development. Using the non-motile Escherichia coli JW1908-1 strain and Gallionella as model organisms, we investigate the behavior and development of bacteria over a range of single and double concentration gradients in the concentrations of nutrients, electron donors and electron acceptors. To quantify bacterial activity we use Fluorescein Diacetate (FDA) hydrolysis by bacterial enzymes which transforms FDA into Fluorescein, whose local concentration is measured optically. We thus measure bacterial activity locally from the time derivative of the measured fluorescence. This approach allows time-resolved monitoring of the location and intensity of reactive hotspots in micromodels as a function of the flow and chemical gradient conditions. We discuss consequences for the formation and temporal dynamics of biofilms in the subsurface.

Limiting concentrations of activated mononucleotides necessary for poly(C)-directed elongation of oligoguanylates

NASA Technical Reports Server (NTRS)

Kanavarioti, A.; Chang, S.; Alberas, D. J.

1990-01-01

Selected imidazolide-activated nucleotides have been subjected to hydrolysis under conditions similar to those that favor their template-directed oligomerization. Rate constants of hydrolysis of the P-N bond in guanosine 5'-monophosphate 2-methylimidazolide (2-MeImpG) and in guanosine 5'-monophosphate imidazolide (ImpG), kh, have been determined in the presence/absence of magnesium ion as a function of temperature and polycytidylate [poly(C)] concentration. Using the rate constant of hydrolysis of 2-MeImpG and the rate constant of elongation, i.e., the reaction of an oligoguanylate with 2-MeImpG in the presence of poly(C) acting as template, the limiting concentration of 2-MeImpG necessary for oligonucleotide elongation to compete with hydrolysis can be calculated. The limiting concentration is defined as the initial concentration of monomer that results in its equal consumption by hydrolysis and by elongation. These limiting concentrations of 2-MeImpG are found to be 1.7 mM at 37 degrees C and 0.36 mM at 1 degrees C. Boundary conditions in the form of limiting concentration of activated nucleotide may be used to evaluate a prebiotic model for chemical synthesis of biopolymers. For instance, the limiting concentration of monomer can be used as a basis of comparison among catalytic, but nonenzymatic, RNA-type systems. We also determined the rate constant of dimerization of 2-MeImpG, k2 = 0.45 +/- 0.06 M-1 h-1 in the absence of poly(C), and 0.45 +/- 0.06 less than or equal to k2 less than or equal to 0.97 +/- 0.13 M-1 h-1 in its presence at 37 degrees C and pH 7.95.(ABSTRACT TRUNCATED AT 250 WORDS).

Environmental impacts of training activities at an air weapons range.

PubMed

Bordeleau, Geneviève; Martel, Richard; Ampleman, Guy; Thiboutot, Sonia

2008-01-01

Within Canada, it has been recognized in the last decade that military training activities may have impacts on the environmental quality of training ranges. However, impacts of activities specific to Air Force Bases have not yet been intensely documented. A hydrogeological study was accomplished at the Cold Lake Air Weapons Range, Alberta, to evaluate the environmental impacts of using bombs, rockets, strafing, and open burning/open detonation (OB/OD) on the quality of soil, ground water, surface water, and lake sediments. Samples were analyzed for metals, anions, ammonium perchlorate (NH(4)ClO(4)), and energetic materials (EM). It was found that training activities did not result in measured values being exceeded on the basis of guidance values for surface water and lake sediments. Contamination by metals was mostly limited to soils, and some metals may be related to the use of bombs (Cd, Cu, Pb), strafe (Cu), and rockets (As, Ba, Cd, Cr, Cu, Fe, Ni, Pb, U, V, Zn). TNT (2,4,6-trinitrotoluene) was the main EM found in soils, while RDX (hexahydro-1,3,5-trinitro-1,3,5-triazine) was more common in ground water. Both are related to live bombing, while nitroglycerine (NG) is related to rocket use and was detected in soils only. Aluminum, nitrate, and ammonium perchlorate detected in ground water may be related to live bombing or rockets. OB/OD operations resulted in the presence of various EM in soils, and of perchlorate and nitrate in ground water. Contamination by metals and explosives in soils was localized around the targets and varied significantly in time; however, in ground water it was more constant and may persist for a period of several years after a target has been removed.

Antibacterial activity of vegetables and juices.

PubMed

Lee, Yee-Lean; Cesario, Thomas; Wang, Yang; Shanbrom, Edward; Thrupp, Lauri

2003-01-01

We evaluated the antibacterial activities of various fruit and vegetable extracts on common potential pathogens including antibiotic-resistant strains. Standardized bacterial inocula were added to serial dilutions of sterile vegetable and fruit extracts in broth, with final bacterial concentrations of 10(4-5) cells/mL. After overnight incubation at 35 degrees C, antibacterial activity was measured by minimum inhibitory and minimum bactericidal dilutions (for raw juices) or concentrations (for tea). Among the vegetable and fruit extracts tested, all green vegetables showed no antibacterial activity on Staphylococcus epidermidis and Klebsiella pneumoniae. All purple and red vegetable and fruit juices had antibacterial activities in dilutions ranging from 1:2 to 1:16. Garlic juice had significant activity, with bactericidal action in dilutions ranging up to 1:128 of the original juice. Tea also had significant activity, with bactericidal action in concentrations ranging up to 1.6 mg/mL, against a spectrum of pathogens including resistant strains such as methicillin- and ciprofloxacin-resistant staphylococci, vancomycin-resistant enterococci, and ciprofloxacin-resistant Pseudomonas aeruginosa. Tea and garlic have the potential for exploration of broader applications as antibacterial agents.

Interaction of Antiinflammatory Drugs with EPC Liposomes: Calorimetric Study in a Broad Concentration Range

PubMed Central

Matos, Carla; Lima, José L. C.; Reis, Salette; Lopes, António; Bastos, Margarida

2004-01-01

Isothermal titration calorimetry was used to characterize and quantify the partition of indomethacin and acemetacin between the bulk aqueous phase and the membrane of egg phosphatidylcholine vesicles. Significant electrostatic effects were observed due to binding of the charged drugs to the membrane, which implied the use of the Gouy-Chapman theory to calculate the interfacial concentrations. The binding/partition phenomenon was quantified in terms of the partition coefficient (Kp), and/or the equilibrium constant (Kb). Mathematical expressions were developed, either to encompass the electrostatic effects in the partition model, or to numerically relate partition coefficients and binding constants. Calorimetric titrations conducted under a lipid/drug ratio >100:1 lead to a constant heat release and were used to directly calculate the enthalpy of the process, ΔH, and indirectly, ΔG and ΔS. As the lipid/drug ratio decreased, the constancy of reaction enthalpy was tested in the fitting process. Under low lipid/drug ratio conditions simple partition was no longer valid and the interaction phenomenon was interpreted in terms of binding isotherms. A mathematical expression was deduced for quantification of the binding constants and the number of lipid molecules associated with one drug molecule. The broad range of concentrations used stressed the biphasic nature of the interaction under study. As the lipid/drug ratio was varied, the results showed that the interaction of both drugs does not present a unique behavior in all studied regimes: the extent of the interaction, as well as the binding stoichiometry, is affected by the lipid/drug ratio. The change in these parameters reflects the biphasic behavior of the interaction—possibly the consequence of a modification of the membrane's physical properties as it becomes saturated with the drug. PMID:14747330

Rapid Response Concentration-Controlled Desorption of Activated Carbon to Dampen Concentration Fluctuations

DTIC Science & Technology

2007-01-01

Behavior of trickle - bed air biofilter for toluene removal: Effect of non-use periods. Environ. Prog. 2005, 24, 155-161. (3) Martin, F. J.; Loehr, R. C...dampen the fluctuation in acetone concentration at high concentrations. The effect of inlet concentration and empty bed contact time (EBCT) on dampening...oxidizer. The MSA-SST system is a fixed- bed system that rapidly controls the power that heats the adsorbent/adsorbate, resulting in controlled

Influence of life-history parameters on organochlorine concentrations in free-ranging killer whales (Orcinus orca) from Prince William Sound, AK.

PubMed

Ylitalo, G M; Matkin, C O; Buzitis, J; Krahn, M M; Jones, L L; Rowles, T; Stein, J E

2001-12-17

Certain populations of killer whales (Orcinus orca) have been extensively studied over the past 30 years, including populations that use Puget Sound, WA, the inside waters of British Columbia, Southeastern Alaska and Kenai Fjords/Prince William Sound, Alaska. Two eco-types of killer whales, 'transient' and 'resident', occur in all of these regions. These eco-types are genetically distinct and differ in various aspects of morphology, vocalization patterns, diet and habitat use. Various genetic and photo-identification studies of eastern North Pacific killer whales have provided information on the male-female composition of most of these resident pods and transient groups, as well as the approximate ages, reproductive status and putative recruitment order (birth order) of the individual whales. Biopsy blubber samples of free-ranging resident and transient killer whales from the Kenai Fjords/Prince William Sound, AK region were acquired during the 1994-1999 field seasons and analyzed for selected organochlorines (OCs), including dioxin-like CB congeners and DDTs. Concentrations of OCs in transient killer whales (marine mammal-eating) were much higher than those found in resident animals (fish-eating) apparently due to differences in diets of these two killer whale eco-types. Certain life-history parameters such as sex, age and reproductive status also influenced the concentrations of OCs in the Alaskan killer whales. Reproductive female whales contained much lower levels of OCs than sexually immature whales or mature male animals in the same age class likely due to transfer of OCs from the female to her offspring during gestation and lactation. Recruitment order also influenced the concentrations of OCs in the Alaskan killer whales. In adult male residents, first-recruited whales contained much higher OC concentrations than those measured in non-first-recruited (e.g. second recruited, third recruited) resident animals in the same age group. This study provides

The Electrostatic Screening Length in Concentrated Electrolytes Increases with Concentration.

PubMed

Smith, Alexander M; Lee, Alpha A; Perkin, Susan

2016-06-16

According to classical electrolyte theories interactions in dilute (low ion density) electrolytes decay exponentially with distance, with the Debye screening length the characteristic length scale. This decay length decreases monotonically with increasing ion concentration due to effective screening of charges over short distances. Thus, within the Debye model no long-range forces are expected in concentrated electrolytes. Here we reveal, using experimental detection of the interaction between two planar charged surfaces across a wide range of electrolytes, that beyond the dilute (Debye-Hückel) regime the screening length increases with increasing concentration. The screening lengths for all electrolytes studied-including aqueous NaCl solutions, ionic liquids diluted with propylene carbonate, and pure ionic liquids-collapse onto a single curve when scaled by the dielectric constant. This nonmonotonic variation of the screening length with concentration, and its generality across ionic liquids and aqueous salt solutions, demonstrates an important characteristic of concentrated electrolytes of substantial relevance from biology to energy storage.

Serum concentration of interleukin-6 is increased both in active and remission stages of pemphigus vulgaris.

PubMed

Narbutt, Joanna; Lukamowicz, Jolanta; Bogaczewicz, Jarosław; Sysa-Jedrzejowska, Anna; Torzecka, Jolanta Dorota; Lesiak, Aleksandra

2008-01-01

As most studies on pemphigus vulgaris (PV) pathogenesis concern its active stage, we aimed to evaluate the serum concentration of TNF-alpha, IL-1, and IL-6 in PV patients in clinical remission. The study group consisted of sera from 19 PV patients in active stage and from 24 patients in clinical remission. 19 sera taken from healthy subjects served as the controls. Serum IL-6 concentrations in PV active and PV remission group were significantly higher when compared to the controls (P < .05). In patients in active stage of PV, a significant correlation between serum IL-1 and IL-6 concentrations was found (r(P) = 0.46; P < .05). We also found a negative correlation between TNF-alpha level and pemphigus antibodies titer in the patients from the remission group (r(S) = -0.47303; P < .02). Our data suggest that IL-6 and TNF-alpha may be involved in maintaining immunological disturbances in remission stage of PV.

Serum Concentration of Interleukin-6 Is Increased Both in Active and Remission Stages of Pemphigus Vulgaris

PubMed Central

Narbutt, Joanna; Lukamowicz, Jolanta; Bogaczewicz, Jarosław; Sysa-Jedrzejowska, Anna; Torzecka, Jolanta Dorota; Lesiak, Aleksandra

2008-01-01

As most studies on pemphigus vulgaris (PV) pathogenesis concern its active stage, we aimed to evaluate the serum concentration of TNF-α, IL-1, and IL-6 in PV patients in clinical remission. The study group consisted of sera from 19 PV patients in active stage and from 24 patients in clinical remission. 19 sera taken from healthy subjects served as the controls. Serum IL-6 concentrations in PV active and PV remission group were significantly higher when compared to the controls (P < .05). In patients in active stage of PV, a significant correlation between serum IL-1 and IL-6 concentrations was found (r P = 0.46; P < .05). We also found a negative correlation between TNF-α level and pemphigus antibodies titer in the patients from the remission group (r S = −0.47303; P < .02). Our data suggest that IL-6 and TNF-α may be involved in maintaining immunological disturbances in remission stage of PV. PMID:18584045

Intrinsic vs. spurious long-range memory in high-frequency records of environmental radioactivity. Critical re-assessment and application to indoor 222Rn concentrations from Coimbra, Portugal

NASA Astrophysics Data System (ADS)

Donner, R. V.; Potirakis, S. M.; Barbosa, S. M.; Matos, J. A. O.; Pereira, A. J. S. C.; Neves, L. J. P. F.

2015-05-01

The presence or absence of long-range correlations in the environmental radioactivity fluctuations has recently attracted considerable interest. Among a multiplicity of practically relevant applications, identifying and disentangling the environmental factors controlling the variable concentrations of the radioactive noble gas radon is important for estimating its effect on human health and the efficiency of possible measures for reducing the corresponding exposition. In this work, we present a critical re-assessment of a multiplicity of complementary methods that have been previously applied for evaluating the presence of long-range correlations and fractal scaling in environmental radon variations with a particular focus on the specific properties of the underlying time series. As an illustrative case study, we subsequently re-analyze two high-frequency records of indoor radon concentrations from Coimbra, Portugal, each of which spans several weeks of continuous measurements at a high temporal resolution of five minutes.Our results reveal that at the study site, radon concentrations exhibit complex multi-scale dynamics with qualitatively different properties at different time-scales: (i) essentially white noise in the high-frequency part (up to time-scales of about one hour), (ii) spurious indications of a non-stationary, apparently long-range correlated process (at time scales between some hours and one day) arising from marked periodic components, and (iii) low-frequency variability indicating a true long-range dependent process. In the presence of such multi-scale variability, common estimators of long-range memory in time series are prone to fail if applied to the raw data without previous separation of time-scales with qualitatively different dynamics.

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

PubMed Central

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

1983-01-01

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

Photosynthetic capacity is negatively correlated with the concentration of leaf phenolic compounds across a range of different species

PubMed Central

Sumbele, Sally; Fotelli, Mariangela N.; Nikolopoulos, Dimosthenis; Tooulakou, Georgia; Liakoura, Vally; Liakopoulos, Georgios; Bresta, Panagiota; Dotsika, Elissavet; Adams, Mark A.; Karabourniotis, George

2012-01-01

Background and aims Phenolic compounds are the most commonly studied of all secondary metabolites because of their significant protective–defensive roles and their significant concentration in plant tissues. However, there has been little study on relationships between gas exchange parameters and the concentration of leaf phenolic compounds (total phenolics (TP) and condensed tannins (CT)) across a range of species. Therefore, we addressed the question: is there any correlation between photosynthetic capacity (Amax) and TP and CT across species from different ecosystems in different continents? Methodology A plethora of functional and structural parameters were measured in 49 plant species following different growth strategies from five sampling sites located in Greece and Australia. The relationships between several leaf traits were analysed by means of regression and principal component analysis. Principal results The results revealed a negative relationship between TP and CT and Amax among the different plant species, growth strategies and sampling sites, irrespective of expression (with respect to mass, area or nitrogen content). Principal component analysis showed that high concentrations of TP and CT are associated with thick, dense leaves with low nitrogen. This leaf type is characterized by low growth, Amax and transpiration rates, and is common in environments with low water and nutrient availability, high temperatures and high light intensities. Therefore, the high TP and CT in such leaves are compatible with the protective and defensive functions ascribed to them. Conclusions Our results indicate a functional integration between carbon gain and the concentration of leaf phenolic compounds that reflects the trade-off between growth and defence/protection demands, depending on the growth strategy adopted by each species. PMID:23050073

Photosynthetic capacity is negatively correlated with the concentration of leaf phenolic compounds across a range of different species.

PubMed

Sumbele, Sally; Fotelli, Mariangela N; Nikolopoulos, Dimosthenis; Tooulakou, Georgia; Liakoura, Vally; Liakopoulos, Georgios; Bresta, Panagiota; Dotsika, Elissavet; Adams, Mark A; Karabourniotis, George

2012-01-01

Phenolic compounds are the most commonly studied of all secondary metabolites because of their significant protective-defensive roles and their significant concentration in plant tissues. However, there has been little study on relationships between gas exchange parameters and the concentration of leaf phenolic compounds (total phenolics (TP) and condensed tannins (CT)) across a range of species. Therefore, we addressed the question: is there any correlation between photosynthetic capacity (A(max)) and TP and CT across species from different ecosystems in different continents? A plethora of functional and structural parameters were measured in 49 plant species following different growth strategies from five sampling sites located in Greece and Australia. The relationships between several leaf traits were analysed by means of regression and principal component analysis. The results revealed a negative relationship between TP and CT and A(max) among the different plant species, growth strategies and sampling sites, irrespective of expression (with respect to mass, area or nitrogen content). Principal component analysis showed that high concentrations of TP and CT are associated with thick, dense leaves with low nitrogen. This leaf type is characterized by low growth, A(max) and transpiration rates, and is common in environments with low water and nutrient availability, high temperatures and high light intensities. Therefore, the high TP and CT in such leaves are compatible with the protective and defensive functions ascribed to them. Our results indicate a functional integration between carbon gain and the concentration of leaf phenolic compounds that reflects the trade-off between growth and defence/protection demands, depending on the growth strategy adopted by each species.

Assessment of concentrations of trace elements in ground water and soil at the Small-Arms Firing Range, Shaw Air Force Base, South Carolina

USGS Publications Warehouse

Landmeyer, J.E.

1994-01-01

Ground-water samples were collected from four shallow water-table aquifer observation wells beneath the Small-Arms Firing Range study area at Shaw Air Force Base. Water-chemistry analyses indicated that total lead concentrations in shallow ground water beneath the study area do not exceed the U.S. Environmental Protection Agency maximum contaminant level established for lead in drinking water (0.05 milligrams per liter). All other trace element total concentrations in ground water beneath the study area were at or below the detection limit of the analytical methodology.

Measurements of the size dependence of the concentration of nonvolatile material in fog droplets

NASA Astrophysics Data System (ADS)

Ogren, J. A.; Noone, K. J.; Hallberg, A.; Heintzenberg, J.; Schell, D.; Berner, A.; Solly, I.; Kruisz, C.; Reischl, G.; Arends, B. G.; Wobrock, W.

1992-11-01

Measurements of the size dependence of the mass concentration of nonvolatile material dissolved and suspended in fog droplets were obtained with three complementary approaches, covering a size range from c. 1 50µm diameter: a counterflow virtual impactor, an eight-stage aerosol impactor, and a two-stage fogwater impactor. Concentrations were observed to decrease with size over the entire range, contrary to expectations of increasing concentrations at larger sizes. It is possible that the larger droplets had solute concentrations that increased with increasing size, but that the increase was too weak for the measurements to resolve. Future studies should consider the hypothesis that the droplets were coated with a surface-active substance that hindered their uptake of water.

Effects of lead on Na+, K+-ATPase and hemolymph ion concentrations in the freshwater mussel Elliptio complanata

USGS Publications Warehouse

Mosher, Shad; Cope, W. Gregory; Weber, Frank X.; Shea, Damian; Kwak, Thomas J.

2012-01-01

Freshwater mussels are an imperiled fauna exposed to a variety of environmental toxicants such as lead (Pb) and studies are urgently needed to assess their health and condition to guide conservation efforts. A 28-day laboratory toxicity test with Pb and adult Eastern elliptio mussels (Elliptio complanata) was conducted to determine uptake kinetics and to assess the toxicological effects of Pb exposure. Test mussels were collected from a relatively uncontaminated reference site and exposed to a water-only control and five concentrations of Pb (as lead nitrate) ranging from 1 to 245 mu g/L in a static renewal test with a water hardness of 42 mg/L. Endpoints included tissue Pb concentrations, hemolymph Pb and ion (Na+, K+, Cl-, Ca2+) concentrations, and Na+, K+-ATPase enzyme activity in gill tissue. Mussels accumulated Pb rapidly, with tissue concentrations increasing at an exposure-dependent rate for the first 2 weeks, but with no significant increase from 2 to 4 weeks. Mussel tissue Pb concentrations ranged from 0.34 to 898 mu g/g dry weight, were strongly related to Pb in test water at every time interval (7, 14, 21, and 28 days), and did not significantly increase after day 14. Hemolymph Pb concentration was variable, dependent on exposure concentration, and showed no appreciable change with time beyond day 7, except for mussels in the greatest exposure concentration (245 mu g/L), which showed a significant reduction in Pb by 28 days, suggesting a threshold for Pb binding or elimination in hemolymph at concentrations near 1000 mu g/g. The Na+, K+-ATPase activity in the gill tissue of mussels was significantly reduced by Pb on day 28 and was highly correlated with tissue Pb concentration (R2 = 0.92; P = 0.013). The Na+, K+-ATPase activity was correlated with reduced hemolymph Na+ concentration at the greatest Pb exposure when enzyme activity was at 30% of controls. Hemolymph Ca2+ concentration increased significantly in mussels from the greatest Pb exposure and may

Relative reactivity of ribosyl 2'-OH vs. 3'-OH in concentrated aqueous solutions of phosphoimidazolide activated nucleotides

NASA Technical Reports Server (NTRS)

Kanavarioti, A.; Lee, L. F.; Gangopadhyay, S.

1999-01-01

Phosphoimidazolide activated ribomononucleotides (*pN, see structure) are useful substrates for the non-enzymatic synthesis of oligonucleotides. In the presence of metal ions, aqueous solutions of *pN yield primarily the two internucleotide-linked (pN2' pN and pN3' pN) and the pyrophosphate-linked (N5' ppN) dimers. Small amounts of cyclic dimers and higher oligomers are also produced. In this study the relative reactivity of 2'-OH vs. 3'-OH was determined from the ratio of the yields of pN2' pN vs. pN3' pN. Experiments were performed at 23 degrees C in the range 7.2 < or = pH < or = 8.4 with substrates that differ in nucleobase (guanosine (G), cytidine (C), uridine (U), and adenosine (A)) and leaving group (imidazole (Im), 2-methylimidazole (2-MeIm) and 2,4-dimethylimidazole (2,4-diMeIm)). Two metal ions (Mg2+ or Mn2+) were employed as catalysts. The conditions used here, i.e. a substrate concentration in the range 0.1 M to 1.0 M and metal ion concentration in the range 0.05 M to 0.2 M, favor base-stacking interactions. The ratio pN2' pN: pN3' pN = 2'-5': 3'-5' was found independent of nucleobase and typically varied between 2 to 3 indicating that the 2'-OH is about 2 to 3 times more reactive than the 3'-OH. *pN with Im, compared to 2-MeIm and 2,4-diMeIm leaving group, produce lower yields of internucleotide linked dimers, and a higher pN2' pN: pN3' pN ratio. Trends in the data, observed with all three leaving groups, suggest an increase in pN2' pN: pN3' pN ratio with decreasing substrate concentration (up to 5.47 with 0.051 M ImpG). The observations are in accord with earlier studies reporting a relative reactivity 2'-5': 3'-5' = 6 to 9 obtained with Im as the leaving group, in dilute nucleotide solutions and under conditions that disfavor stacking. It is speculated that the concentration induced change in the relative reactivity is the result of self-association via base-stacking that enhances selectively the proximity of the 3'-OH of one molecule to the reactive

Changes in active ankle dorsiflexion range of motion after acute inversion ankle sprain.

PubMed

Youdas, James W; McLean, Timothy J; Krause, David A; Hollman, John H

2009-08-01

Posterior calf stretching is believed to improve active ankle dorsiflexion range of motion (AADFROM) after acute ankle-inversion sprain. To describe AADFROM at baseline (postinjury) and at 2-wk time periods for 6 wk after acute inversion sprain. Randomized trial. Sports clinic. 11 men and 11 women (age range 11-54 y) with acute inversion sprain. Standardized home exercise program for acute inversion sprain. AADFROM with the knee extended. Time main effect on AADFROM was significant (F3,57 = 108, P < .001). At baseline, mean active sagittal-plane motion of the ankle was 6 degrees of plantar flexion, whereas at 2, 4, and 6 wk AADFROM was 7 degrees, 11 degrees, and 11 degrees, respectively. AADFROM increased significantly from baseline to week 2 and from week 2 to week 4. Normal AADFROM was restored within 4 wk after acute inversion sprain.

Calculating Capstone Depleted Uranium Aerosol Concentrations from Beta Activity Measurements

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

Szrom, Fran; Falo, Gerald A.; Parkhurst, MaryAnn

2009-03-01

Beta activity measurements were used as surrogate measurements of uranium mass in aerosol samples collected during the field testing phase of the Capstone Depleted Uranium (DU) Aerosol Study. These aerosol samples generated by the perforation of armored combat vehicles were used to characterize the depleted uranium (DU) source term for the subsequent human health risk assessment (HHRA) of Capstone aerosols. Establishing a calibration curve between beta activity measurements and uranium mass measurements is straightforward if the uranium isotopes are in equilibrium with their immediate short-lived, beta-emitting progeny. For DU samples collected during the Capstone study, it was determined that themore » equilibrium between the uranium isotopes and their immediate short lived, beta-emitting progeny had been disrupted when penetrators had perforated target vehicles. Adjustments were made to account for the disrupted equilibrium and for wall losses in the aerosol samplers. Correction factors for the disrupted equilibrium ranged from 0.16 to 1, and the wall loss correction factors ranged from 1 to 1.92.« less

Soda Creek springs - metamorphic waters in the eastern Alaska Range

USGS Publications Warehouse

Richter, D.H.; Donaldson, D.E.; Lamarre, R.A.

1973-01-01

The Soda Creek springs are a group of small, cold mineral springs on the southern flank of the eastern Alaska Range. The spring waters contain anomalous concentrations of carbon dioxide, sodium, chlorine, sulfate, boron, and ammonia and are actively precipitating deposits of calcite and aragonite. Sparingly present in these deposits are mixed-layer illite-montmorillonite clays and zeolite minerals. Low-temperaturemetamorphic reactions in subjacent marine sedimentary rocks of Jurassic and Cretaceous age may have produced the fluids and silicate minerals. With only a few exceptions, cool bicarbonate-rich springs in Alaska are concentrated south of the Denali fault system in south-central Alaska, southeastern Alaska, and along the Kaltag-Tintina fault system. These areas are characterized by active or recently activetectonism, major faults and folds, and an abundance of marine sedimentary rocks.

Nonimaging polygonal mirrors achieving uniform irradiance distributions on concentrating photovoltaic cells.

PubMed

Schmitz, Max; Dähler, Fabian; Elvinger, François; Pedretti, Andrea; Steinfeld, Aldo

2017-04-10

We introduce a design methodology for nonimaging, single-reflection mirrors with polygonal inlet apertures that generate a uniform irradiance distribution on a polygonal outlet aperture, enabling a multitude of applications within the domain of concentrated photovoltaics. Notably, we present single-mirror concentrators of square and hexagonal perimeter that achieve very high irradiance uniformity on a square receiver at concentrations ranging from 100 to 1000 suns. These optical designs can be assembled in compound concentrators with maximized active area fraction by leveraging tessellation. More advanced multi-mirror concentrators, where each mirror individually illuminates the whole area of the receiver, allow for improved performance while permitting greater flexibility for the concentrator shape and robustness against partial shading of the inlet aperture.

Evaluation of the activity concentrations of (137) Cs and (40)K in some Chanterelle mushrooms from Poland and China.

PubMed

Falandysz, Jerzy; Zalewska, Tamara; Apanel, Anna; Drewnowska, Małgorzata; Kluza, Karolina

2016-10-01

The activity concentrations of (137)Cs and (40)K in mushrooms of the genus Cantharellus (Cantharellus cibarius, Cantharellus tubaeformis, and Cantharellus minor) collected across Poland from 1997 to 2013 and in Yunnan province of China in 2013 were determined using gamma spectrometry with an HPGe detector, respectively. Activity concentrations of (137)Cs in C. cibarius from the places in Poland varied from 64 ± 3 to 1600 ± 47 Bq kg(-1) db in 1997-2004 and 4.2 ± 1.2 to 1400 ± 15 Bq kg(-1) db in 2006-2013. In the Chinese Cantharellus mushrooms, the activity level of (137)Cs was very low, i.e., at a range <1.2 to 1.2 ± 0.6 Bq kg(-1) dry biomass. The natural radionuclide (40)K was at similar activity level in C. cibarius collected across Poland and in China, and fluctuations in levels of (40)K over the years and locations in Poland were small. In C. cibarius from diverse sites in Poland, content of (137)Cs highly fluctuated in 1998-2013 but no clear downward trend was visible (Fig. 1). Published activity levels of (137)Cs in fruitbodies of Cantharellus such Cantharellus californicus, Cantharellus cascadensis, C. cibarius, Cantharellus cinnabarius, Cantharellus formosus, Cantharellus iuteocomus, Cantharellus lutescens, Cantharellus minor, Cantharellus pallens [current name C. cibarius], Cantharellus subalbidus, Cantharellus subpruinosus, and C. tubaeformis collected worldwide were compared. In the Polish cuisine, mushrooms of the genus Cantharellus are blanched before frying or pickling, and this kind of treatment, and additionally also pickling, both very efficiently remove alkali elements (and radioactivity from (134/137)Cs) from flesh of the species.

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....

Ultra-wide detectable concentration range of GMR biosensors using Fe3O4 microspheres

NASA Astrophysics Data System (ADS)

Xu, Jie; Li, Qiang; Zong, Weihua; Zhang, Yongcheng; Li, Shandong

2016-11-01

Exchange-biased GMR sensors were employed for biodetection using a DC in-plane measuring method and a magnetic label of Fe3O4 microspheres. It was revealed that an ultra-wide concentration span covering five orders from 10 ng/mL to 1000 μg/mL was achieved in a home-made biodetection device. The concentration x dependence of output voltage difference |ΔV| between with and without magnetic labels, exhibits nonlinear futures, which undergoes two functions depending on the concentration region. For the low concentration region from 10 ng/mL to 10 μg/mL, a logarithmic relation of |ΔV|=26.3lgx+91.4 fits well, while for the high concentration region, a negative exponential function of |ΔV|=3113(1-e-x/250) describes the |ΔV|~x relation better. For the former, the "coffee ring" effect, formed during the solvent evaporation, was considered as the main reason for the nonlinear relation. While for the latter with high concentration, the overlap among the particles and the enhanced interaction of the magnetic dipole were responsible for the nonlinear |ΔV|~x relationship. Moreover, the calculated detectable concentration limit is agreed well with the experimental data.

Concentration and Separation of Active Proteins from Potato Industry Waste Based on Low-Temperature Evaporation and Ethanol Precipitation

PubMed Central

Ahokas, Mikko; Järvinen, Juho; Toivanen, Juho; Tanskanen, Juha P.

2017-01-01

Purpose. Potato fruit juice, a residue of starch industry, contains up to 2.5% [w/w] of proteins that are potentially valuable raw-materials of food, cosmetic, and pharma industries. The recovery of protein from the potato fruit juice is limited by the lack of industrially feasible concentration and separation technologies. The present research thus aimed at development of such process for the separation of active protease inhibitors from potato fruit juice. Methods. Low temperature mechanical vapor recompression evaporation was applied for concentration of potato fruit juice followed by ethanol precipitation for recovery of active proteins. The effects of precipitation temperature and precipitative agents were investigated employing response surface modeling methodology. Results. Concentration of potato fruit juice by evaporation was successful without loss of trypsin inhibition activity. Precipitation using 6.5 M ethanol at low temperature (0–+4°C) was found suitable for the recovery of active protease inhibitors from the concentrate. Piloting at starch industry yielded 50% of total proteins, with a high quantity of active protease inhibitors and a minor inclusion of other proteins. Conclusion. Concentration by low-temperature evaporation, followed by ethanol precipitation of protease inhibitors at optimized temperature, is an attractive option for valorization of potato fruit juice. PMID:28299232

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

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.

Long-range Electrostatic Complementarity Governs Substrate Recognition by Human Chymotrypsin C, a Key Regulator of Digestive Enzyme Activation*

PubMed Central

Batra, Jyotica; Szabó, András; Caulfield, Thomas R.; Soares, Alexei S.; Sahin-Tóth, Miklós; Radisky, Evette S.

2013-01-01

Human chymotrypsin C (CTRC) is a pancreatic serine protease that regulates activation and degradation of trypsinogens and procarboxypeptidases by targeting specific cleavage sites within their zymogen precursors. In cleaving these regulatory sites, which are characterized by multiple flanking acidic residues, CTRC shows substrate specificity that is distinct from that of other isoforms of chymotrypsin and elastase. Here, we report the first crystal structure of active CTRC, determined at 1.9-Å resolution, revealing the structural basis for binding specificity. The structure shows human CTRC bound to the small protein protease inhibitor eglin c, which binds in a substrate-like manner filling the S6-S5′ subsites of the substrate binding cleft. Significant binding affinity derives from burial of preferred hydrophobic residues at the P1, P4, and P2′ positions of CTRC, although acidic P2′ residues can also be accommodated by formation of an interfacial salt bridge. Acidic residues may also be specifically accommodated in the P6 position. The most unique structural feature of CTRC is a ring of intense positive electrostatic surface potential surrounding the primarily hydrophobic substrate binding site. Our results indicate that long-range electrostatic attraction toward substrates of concentrated negative charge governs substrate discrimination, which explains CTRC selectivity in regulating active digestive enzyme levels. PMID:23430245

Bone Mineral Density across a Range of Physical Activity Volumes: NHANES 2007–2010

PubMed Central

Whitfield, Geoffrey P.; Kohrt, Wendy M.; Pettee Gabriel, Kelley K.; Rahbar, Mohammad H.; Kohl, Harold W.

2014-01-01

Introduction The association between aerobic physical activity volume and bone mineral density (BMD) is not completely understood. The purpose of this study was to clarify the association between BMD and aerobic activity across a broad range of activity volumes, in particular volumes between those recommended in the 2008 Physical Activity Guidelines for Americans and those of trained endurance athletes. Methods Data from the 2007–2010 National Health and Nutrition Examination Survey were used to quantify the association between reported physical activity and BMD at the lumbar spine and proximal femur across the entire range of activity volumes reported by US adults. Participants were categorized into multiples of the minimum guideline-recommended volume based on reported moderate and vigorous intensity leisure activity. Lumbar and proximal femur BMD was assessed with dual-energy x-ray absorptiometry. Results Among women, multivariable-adjusted linear regression analyses revealed no significant differences in lumbar BMD across activity categories, while proximal femur BMD was significantly higher among those who exceeded guidelines by 2–4 times than those who reported no activity. Among men, multivariable-adjusted BMD at both sites neared its highest values among those who exceeded guidelines by at least 4 times and was not progressively higher with additional activity. Logistic regression estimating the odds of low BMD generally echoed the linear regression results. Conclusion The association between physical activity volume and BMD is complex. Among women, exceeding guidelines by 2–4 times may be important for maximizing BMD at the proximal femur, while among men, exceeding guidelines by 4+ times may be beneficial for lumbar and proximal femur BMD. PMID:24870584

Carbonic anhydrase levels and internal lacunar CO/sub 2/ concentrations in aquatic macrophytes

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

Weaver, C.I.

1979-01-01

Carbonic anhydrase levels were examined in a variety of aquatic macrophytes from different habitats. In general, carbonic anhydrase levels increased across the habitat gradient such that activities were low in submersed aquatic macrophytes and high in emergent macrophytes with floating-leaved and free-floating plants exhibiting intermediate activities. Internal lacunar CO/sub 2/ concentrations were analyzed in relation to carbonic anhydrase activities. There was no correlation between these two parameters. Internal CO/sub 2/ concentrations ranged from low to high in submersed macrophytes, but were low in floating-leaved and emergent macrophytes. The observed internal CO/sub 2/ concentrations are discussed in relation to the individualmore » morphologies of the plants and the environments in which they occurred.« less

Extracts of Agrimonia eupatoria L. as sources of biologically active compounds and evaluation of their antioxidant, antimicrobial, and antibiofilm activities.

PubMed

Muruzović, Mirjana Ž; Mladenović, Katarina G; Stefanović, Olgica D; Vasić, Sava M; Čomić, Ljiljana R

2016-07-01

In this study, we determined the concentration of total phenols, flavonoids, tannins, and proanthocyanidins in the water, diethyl ether, acetone, and ethanol extracts of Agrimonia eupatoria L. We also investigated the antioxidant activity of these extracts using two methods [2,2-diphenyl-1-picrylhydrazyl (DPPH) and reducing power] and their in vitro antimicrobial (antibacterial and antifungal) activity on some selected species of bacteria and fungi. In addition, the effects of the acetone and water extracts on the inhibition of biofilm formation of Proteus mirabilis and Pseudomonas aeruginosa were investigated using the crystal violet method. The concentration of total phenols was measured according to the Folin-Ciocalteu method and the values obtained ranged from 19.61 mgGA/g to 220.31 mgGA/g. The concentration of flavonoids was examined by the aluminum chloride method and the values obtained ranged from 20.58 mgRU/g to 97.06 mgRU/g. The total tannins concentration was measured by the polyvinylpolypyrrolidone method and the values obtained ranged from 3.06 mgGA/g to 207.27 mgGA/g. The concentration of proanthocyanidins was determined by the butanol-HCl method and the values obtained ranged from 4.15 CChE/g to 103.72 CChE/g. Among the various extracts studied, the acetone extract exhibited good antioxidant activity (97.13%, as determined by the DPPH method). The acetone extract was active in the absorbance value range from 2.2665 to 0.2495 (as determined by the reducing power method). The strongest antimicrobial activity was detected on G + bacteria, especially on probiotic species, and the acetone extract demonstrated the highest activity. Biofilm inhibitory concentration required to reduce biofilm coverage by 50% values for acetone extract was 4315 μg/mL for P. mirabilis and 4469.5 μg/mL for P. aeruginosa. The results provide a basis for further research of this plant species. Copyright © 2016. Published by Elsevier B.V.

Coupling of the phosphatase activity of Ci-VSP to its voltage sensor activity over the entire range of voltage sensitivity

PubMed Central

Sakata, Souhei; Hossain, Md. Israil; Okamura, Yasushi

2011-01-01

Abstract The voltage sensing phosphatase Ci-VSP is composed of a voltage sensor domain (VSD) and a cytoplasmic phosphatase domain. Upon membrane depolarization, movement of the VSD triggers the enzyme's phosphatase activity. To gain further insight into its operating mechanism, we studied the PI(4,5)P2 phosphatase activity of Ci-VSP expressed in Xenopus oocytes over the entire range of VSD motion by assessing the activity of coexpressed Kir2.1 channels or the fluorescence signal from a pleckstrin homology domain fused with green fluorescent protein (GFP) (PHPLC-GFP). Both assays showed greater phosphatase activity at 125 mV than at 75 mV, which corresponds to ‘sensing’ charges that were 90% and 75% of maximum, respectively. On the other hand, the activity at 160 mV (corresponding to 98% of the maximum ‘sensing’ charge) was indistinguishable from that at 125 mV. Modelling the kinetics of the PHPLC-GFP fluorescence revealed that its time course was dependent on both the level of Ci-VSP expression and the diffusion of PHPLC-GFP beneath the plasma membrane. Enzyme activity was calculated by fitting the time course of PHPLC-GFP fluorescence into the model. The voltage dependence of the enzyme activity was superimposable on the Q–V curve, which is consistent with the idea that the enzyme activity is tightly coupled to VSD movement over the entire range of membrane potentials that elicit VSD movement. PMID:21486809

Dysfunctional long-range coordination of neural activity during Gestalt perception in schizophrenia.

PubMed

Uhlhaas, Peter J; Linden, David E J; Singer, Wolf; Haenschel, Corinna; Lindner, Michael; Maurer, Konrad; Rodriguez, Eugenio

2006-08-02

Recent theoretical and empirical research on schizophrenia converges on the notion that core aspects of the pathophysiology of the disorder may arise from a dysfunction in the coordination of distributed neural activity. Synchronization of neural responses in the beta-band (15-30 Hz) and gamma-band range (30-80 Hz) has been implicated as a possible neural substrate for dysfunctional coordination in schizophrenia. To test this hypothesis, we examined the electroencephalography (EEG) activity in 19 patients with a Diagnostic and Statistical Manual of Mental Disorder, edition IV criteria, diagnosis of schizophrenia and 19 healthy control subjects during a Gestalt perception task. EEG data were analyzed for phase synchrony and induced spectral power as an index of neural synchronization. Schizophrenia patients were impaired significantly in the detection of images that required the grouping of stimulus elements into coherent object representations. This deficit was accompanied by longer reaction times in schizophrenia patients. Deficits in Gestalt perception in schizophrenia patients were associated with reduced phase synchrony in the beta-band (20-30 Hz), whereas induced spectral power in the gamma-band (40-70 Hz) was mainly intact. Our findings suggest that schizophrenia patients are impaired in the long-range synchronization of neural responses, which may reflect a core deficit in the coordination of neural activity and underlie the specific cognitive dysfunctions associated with the disorder.

Frugivory is associated with low measures of plasma oxidative stress and high antioxidant concentration in free-ranging bats

NASA Astrophysics Data System (ADS)

Schneeberger, Karin; Czirják, Gábor Á.; Voigt, Christian C.

2014-04-01

Oxidative stress—an imbalance between reactive pro- and neutralising antioxidants—damages cell structures and impairs fitness-relevant traits such as longevity and reproduction. Theory predicts that feeding on diets with high antioxidant content such as fruits should reduce oxidative stress; however, there is no support of this idea in free-ranging mammals. Bats cover a large variety of ecological niches, and therefore, we asked if measures of oxidative stress are lower in species with fruit diets. We measured reactive oxygen metabolites (ROM) representing total pro-oxidants produced and antioxidants in the plasma of 33 Neotropical bat species. Species with a fruit diet showed the lowest level of ROM and the highest concentration of antioxidants, followed by omnivorous and animalivorous species. Potentially, frugivorous species ingest more antioxidants with food and thus are able to neutralise more pro-oxidants than species not feeding on fruits, resulting in an overall lower level of oxidative stress. We therefore showed for the first time that measures of oxidative stress vary according to diets in free-ranging mammals.

Single-molecule imaging at high fluorophore concentrations by local activation of dye

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

Geertsema, Hylkje J.; Mangel, Walter F.; Schulte, Aartje C.

Single-molecule fluorescence microscopy is a powerful approach to observe biomolecular interactions with high spatial and temporal resolution. Detecting fluorescent signals from individual, labeled proteins above high levels of background fluorescence remains challenging, however. For this reason, the concentrations of labeled proteins in in vitro assays are often kept low compared to their in vivo concentrations. Here, we present a new fluorescence imaging technique by which single fluorescent molecules can be observed in real time at high, physiologically relevant concentrations. The technique requires a protein and its macromolecular substrate to be labeled each with a different fluorophore. Then, making use ofmore » short-distance energy-transfer mechanisms, the fluorescence from only those proteins bound to their substrate are selectively activated. This approach is demonstrated by labeling a DNA substrate with an intercalating stain, exciting the stain, and using energy transfer from the stain to activate the fluorescence of only those labeled DNA-binding proteins bound to the DNA. Such an experimental design allowed us to observe the sequence-independent interaction of Cy5-labeled interferon-inducible protein 16 (IFI16) with DNA and the sliding via one-dimensional diffusion of Cy5-labeled adenovirus protease (pVIc-AVP) on DNA in the presence of a background of hundreds of nM Cy5 fluorophore.« less

Single-molecule imaging at high fluorophore concentrations by local activation of dye

DOE PAGES

Geertsema, Hylkje J.; Mangel, Walter F.; Schulte, Aartje C.; ...

2015-02-17

Single-molecule fluorescence microscopy is a powerful approach to observe biomolecular interactions with high spatial and temporal resolution. Detecting fluorescent signals from individual, labeled proteins above high levels of background fluorescence remains challenging, however. For this reason, the concentrations of labeled proteins in in vitro assays are often kept low compared to their in vivo concentrations. Here, we present a new fluorescence imaging technique by which single fluorescent molecules can be observed in real time at high, physiologically relevant concentrations. The technique requires a protein and its macromolecular substrate to be labeled each with a different fluorophore. Then, making use ofmore » short-distance energy-transfer mechanisms, the fluorescence from only those proteins bound to their substrate are selectively activated. This approach is demonstrated by labeling a DNA substrate with an intercalating stain, exciting the stain, and using energy transfer from the stain to activate the fluorescence of only those labeled DNA-binding proteins bound to the DNA. Such an experimental design allowed us to observe the sequence-independent interaction of Cy5-labeled interferon-inducible protein 16 (IFI16) with DNA and the sliding via one-dimensional diffusion of Cy5-labeled adenovirus protease (pVIc-AVP) on DNA in the presence of a background of hundreds of nM Cy5 fluorophore.« less

Cervicocephalic kinesthetic sensibility, active range of cervical motion, and oculomotor function in patients with whiplash injury.

PubMed

Heikkilä, H V; Wenngren, B I

1998-09-01

To investigate cervicocephalic kinesthetic sensibility, active range of cervical motion, and oculomotor function in patients with whiplash injury. A 2-year review of consecutive patients admitted to the emergency unit after whiplash injury. An otorhinolaryngology department. Twenty-seven consecutive patients with diagnosed whiplash injury (14 men and 13 women, mean age, 33.8yrs [range, 18 to 66yrs]). The controls were healthy subjects without a history of whiplash injury. Oculomotor function was tested at 2 months and at 2 years after whiplash injury. The ability to appreciate both movement and head position was studied. Active range of cervical motion was measured. Subjective intensity of neck pain and major medical symptoms were recorded. Active head repositioning was significantly less precise in the whiplash subjects than in the control group. Failures in oculomotor functions were observed in 62% of subjects. Significant correlations occurred between smooth pursuit tests and active cervical range of motion. Correlations also were established between the oculomotor test and the kinesthetic sensibility test. The results suggest that restricted cervical movements and changes in the quality of proprioceptive information from the cervical spine region affect voluntary eye movements. A flexion/extension injury to the neck may result in dysfunction of the proprioceptive system. Oculomotor dysfunction after neck trauma might be related to cervical afferent input disturbances.

Vasopressin activates Akt/mTOR pathway in smooth muscle cells cultured in high glucose concentration

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

Montes, Daniela K.; Brenet, Marianne; Muñoz, Vanessa C.

Highlights: •AVP induces mTOR phosphorylation in A-10 cells cultured in high glucose concentration. •The mTOR phosphorylation is mediated by the PI3K/Akt pathway activation. •The AVP-induced mTOR phosphorylation inhibited autophagy and stimulated cell proliferation. -- Abstract: Mammalian target of rapamycin (mTOR) complex is a key regulator of autophagy, cell growth and proliferation. Here, we studied the effects of arginine vasopressin (AVP) on mTOR activation in vascular smooth muscle cells cultured in high glucose concentration. AVP induced the mTOR phosphorylation in A-10 cells grown in high glucose, in contrast to cells cultured in normal glucose; wherein, only basal phosphorylation was observed. Themore » AVP-induced mTOR phosphorylation was inhibited by a PI3K inhibitor. Moreover, the AVP-induced mTOR activation inhibited autophagy and increased thymidine incorporation in cells grown in high glucose. This increase was abolished by rapamycin which inhibits the mTORC1 complex formation. Our results suggest that AVP stimulates mTOR phosphorylation by activating the PI3K/Akt signaling pathway and, subsequently, inhibits autophagy and raises cell proliferation in A-10 cells maintained in high glucose concentration.« less

Dose-ranging study of the novel recombinant plasminogen activator BM 06.022 in healthy volunteers.

PubMed

Martin, U; von Möllendorff, E; Akpan, W; Kientsch-Engel, R; Kaufmann, B; Neugebauer, G

1991-10-01

The novel recombinant plasminogen activator BM 06.022 consists of the kringle 2 and protease domains of human tissue-type plasminogen activator and is unglycosylated because of its expression in Escherichia coli cells. Pharmacokinetics for activity and hemostatic effects of BM 06.022 were studied in 18 healthy male volunteers after an intravenous bolus injection over 2 minutes. BM 06.022 was administered successively at doses of 0.1125, 0.55, 2.2, 3.3, 4.4, and 5.5 MU to three volunteers. Plasma fibrinogen was unchanged; effects of BM 06.022 were observed on plasminogen only at higher doses, and dose-dependent effects were seen on alpha 2-antiplasmin and fibrin D-dimers. The concentration of plasminogen and alpha 2-antiplasmin was 87% +/- 3% and 79% +/- 3%, respectively, of baseline 2 hours after injection of 5.5 MU of BM 06.022. Fibrin D-dimers were highest with 1147 +/- 380 ng/ml at 5.5 MU of BM 06.022. The area under the activity concentration-time curve (AUC) increased dose-dependently and linearly. At 5.5 MU of BM 06.022, the AUC was 313 +/- 47 IU.hr.ml-1, the total plasma clearance was 306 +/- 40 ml/min, and the half-life was 14.4 +/- 1.1 minutes.

The Relationship Between Vitamin E Plasma and BAL Concentrations, SOD Activity and Ventilatory Support Measures in Critically Ill Patients

PubMed Central

Ziaie, Shadi; Jamaati, Hamidreza; Hajimahmoodi, Mannan; Hashemian, Seyyed Mohammadreza; Fahimi, Fanak; Farzanegan, Behrooz; Moghaddam, Ghazaleh; Radmand, Golnar; Vahdani, Behzad; Nadji, Seyed Alireza; Mousavi, Sarah; Hamishehkar, Hadi; Mojtahedzadeh, Mojtaba

2011-01-01

Vitamin E is a potent reactive oxygen metabolites (ROM) scavenger. It is a lipid-soluble vitamin and its main function is to protect polyunsaturated fatty acids against oxidative stress. Twenty-five mechanically ventilated Intensive Care Unit (ICU) adult patients participated in a prospective randomized clinical trial receiving either placebo (10 patients) or 3 IM doses (1000 IU each) of vitamin E (15 patients). We determined plasma and bronchoalveolar lavage (BAL) fluid concentrations of vitamin E and superoxide dismutase (SOD). Among these 25 patients, there were 14 men and 11 women, aged 63.16 ±15.48 years (mean ± SD; range = 33 to 87 years). Vitamin E supplementation resulted in significant differences in plasma and BAL vitamin E concentrations between the two groups (p-value = 0.01, 0.01), decrease in SOD activities (not differ significantly in plasma (p-value = 0.23)), but with significant differences in BAL (p-value = 0.016) and progressive reduction in Acute Physiology and Chronic Health Evaluation II (APACHE II) (p-value = 0.52) and Sequential Organ Failure Assessment (SOFA) (p-value = 0.008) score in vitamin E group. From the results of this study, it seems that supplementation of vitamin E as a potent antioxidant, along with other supportive measures, can be beneficial in decreasing SOD total activity, ROM production and risk of organ failure in critically ill patients. PMID:24250434

Airborne measurement of submicron aerosol number concentration and CCN activity in and around the Korean Peninsula and their comparison to ground measurement in Seoul

NASA Astrophysics Data System (ADS)

Park, M.; Kim, N.; Yum, S. S.

2016-12-01

Aerosols exert impact not only on human health and visibility but also on climate change directly by scattering or absorbing solar radiation and indirectly by acting as cloud condensation nuclei (CCN) and thus altering cloud radiative and microphysical properties. Aerosol indirect effects on climate has been known to have large uncertainty because of insufficient measurement data on aerosol and CCN activity distribution. Submicron aerosol number concentration (NCN, TSI CPC) and CCN number concentration (NCCN, DMT CCNC) were measured on board the NASA DC-8 research aircraft and at a ground site at Olympic Park in Seoul from May 2nd to June 10th, 2016. CCNC on the airborne platform was operated with the fixed internal supersaturation of 0.6% and CCNC at the ground site was operated with the five different supersaturations (0.2%, 0.4%, 0.6%, 0.8%, and 1.0%). The NASA DC-8 conducted 20 research flights (about 150 hours) in and around the Korean Peninsula and the ground measurement at Olympic Park was continuously made during the measurement period. Both airborne and ground measurements showed spatially and temporally varied aerosol number concentration and CCN activity. Aerosol number concentration in the boundary layer measured on airborne platform was highly affected by pollution sources on the ground. The average diurnal distribution of ground aerosol number concentration showed distinct peaks are located at about 0800, 1500, and 2000. The middle peak indicates that new particle formation events frequently occurred during the measurement period. CCN activation ratio at 0.6% supersaturation (NCCN/NCN) of the airborne measurement ranged from 0.1 to 0.9, indicating that aerosol properties in and around the Korean Peninsula varied so much (e. g. size, hygroscopicity). Comprehensive analysis results will be shown at the conference.

Elevated Concentrations of Serum Immunoglobulin Free Light Chains in Systemic Lupus Erythematosus Patients in Relation to Disease Activity, Inflammatory Status, B Cell Activity and Epstein-Barr Virus Antibodies

PubMed Central

Draborg, Anette H.; Lydolph, Magnus C.; Westergaard, Marie; Olesen Larsen, Severin; Nielsen, Christoffer T.; Duus, Karen; Jacobsen, Søren; Houen, Gunnar

2015-01-01

Objective In this study, we examined the concentration of serum immunoglobulin free light chains (FLCs) in systemic lupus erythematosus (SLE) patients and investigated its association with various disease parameters in order to evaluate the role of FLCs as a potential biomarker in SLE. Furthermore, FLCs’ association with Epstein-Barr virus (EBV) antibodies was examined. Methods Using a nephelometric assay, κFLC and λFLC concentrations were quantified in sera from 45 SLE patients and 40 healthy controls. SLE patients with renal insufficiency were excluded in order to preclude high concentrations of serum FLCs due to decreased clearance. Results Serum FLC concentrations were significantly elevated in SLE patients compared to healthy controls (p<0.0001) also after adjusting for Ig levels (p<0.0001). The concentration of serum FLCs correlated with a global disease activity (SLE disease activity index (SLEDAI)) score of the SLE patients (r = 0.399, p = 0.007). Furthermore, concentrations of FLCs correlated with titers of dsDNA antibodies (r = 0.383, p = 0.009), and FLC levels and SLEDAI scores correlated in the anti-dsDNA-positive SLE patients, but not in anti-dsDNA-negative SLE patients. Total immunoglobulin (IgG and IgA) concentrations correlated with FLC concentrations and elevated FLC levels were additionally shown to associate with the inflammatory marker C-reactive protein and also with complement consumption determined by low C4 in SLE patients. Collectively, results indicated that elevated serum FLCs reflects increased B cell activity in relation to inflammation. SLE patients had an increased seropositivity of EBV-directed antibodies that did not associate with elevated FLC concentrations. An explanation for this could be that serum FLC concentrations reflect the current EBV activity (reactivation) whereas EBV-directed antibodies reflect the extent of previous infection/reactivations. Conclusion SLE patients have elevated concentrations of serum FLCs that

The relationship between the plasma concentration of blonanserin, and its plasma anti-serotonin 5-HT(2A) activity/anti-dopamine D₂ activity ratio and drug-induced extrapyramidal symptoms.

PubMed

Suzuki, Hidenobu; Gen, Keishi

2012-03-01

 Blonanserin is a second-generation antipsychotic that was developed in Japan. We investigated the relationships between plasma concentration, the plasma anti-5-HT(2A) activity/anti-D₂ activity (S/D) ratio and extrapyramidal symptoms (EPS) in blonanserin dosing.  The subjects were 29 outpatients with schizophrenia. We assessed EPS using the Drug-Induced Extrapyramidal Symptoms Scale (DIEPSS). The plasma concentrations were measured by high performance liquid chromatography, and the plasma anti-D₂ and anti-5-HT(2A) activities were measured by [³H]-spiperone and [³H]-ketanserin radioreceptor assays. The results revealed that there were significant correlations between both the plasma concentration and the DIEPSS total score (P<0.05). A negative correlative tendency was found between the S/D ratio and the DIEPSS total score. Furthermore, the plasma concentrations were divided into a low plasma concentration group and a high plasma concentration group, and the S/D ratios were divided into a low S/D ratio group and a high S/D ratio group. We then compared each group based on the DIEPSS total scores. The score in the high plasma concentration-low S/D ratio group was significantly higher than in the high plasma concentration-high S/D ratio, low plasma concentration-high S/D ratio and low plasma concentration-low S/D ratio groups (P<0.05 for all).  These findings indicate that the incidence of EPS during treatment with blonanserin is mainly determined by plasma concentration, but the incidence of EPS may be inhibited when anti-5HT(2A) activity is predominant over anti-D₂ activity. © 2012 The Authors. Psychiatry and Clinical Neurosciences © 2012 Japanese Society of Psychiatry and Neurology.

An exonuclease I-based label-free fluorometric aptasensor for adenosine triphosphate (ATP) detection with a wide concentration range.

PubMed

Wei, Yanli; Chen, Yanxia; Li, Huanhuan; Shuang, Shaomin; Dong, Chuan; Wang, Gufeng

2015-01-15

A novel aptamer-based label-free assay for sensitive and selective detection of ATP was developed. This assay employs a new aptamer/fluorescent probe system that shows resistance to exonuclease I (Exo I) digestion upon binding to ATP molecules. In the absence of ATP, the complex between the ATP-binding aptamer (ATP-aptamer) and a DNA binding dye, berberine, is digested upon the addition of exonuclease I, leading to the release of berberine into solution and consequently, quenched berberine fluorescence. In the presence of ATP, the ATP-binding aptamer folds into a G-quadruplex structure that is resistant to Exo I digestion. Accordingly, berberine is protected in the G-quadruplex structure and high fluorescence intensity is observed. As such, based on the fluorescence signal change, a label-free fluorescence assay for ATP was developed. Factors affecting the analysis of ATP including the concentration of ATP-binding aptamer, reaction time, temperature and the concentration of Exo I were comprehensively investigated. Under optimal conditions, the fluorescence intensity of the sensing system displayed a response for ATP in a wide range up to 17.5 mM with a detection limit of 140 nM.

Complex Terahertz and Direct Current Inverse Spin Hall Effect in YIG/Cu1-xIrx Bilayers Across a Wide Concentration Range.

PubMed

Cramer, Joel; Seifert, Tom; Kronenberg, Alexander; Fuhrmann, Felix; Jakob, Gerhard; Jourdan, Martin; Kampfrath, Tobias; Kläui, Mathias

2018-02-14

We measure the inverse spin Hall effect of Cu 1-x Ir x thin films on yttrium iron garnet over a wide range of Ir concentrations (0.05 ⩽ x ⩽ 0.7). Spin currents are triggered through the spin Seebeck effect, either by a continuous (dc) temperature gradient or by ultrafast optical heating of the metal layer. The spin Hall current is detected by electrical contacts or measurement of the emitted terahertz radiation. With both approaches, we reveal the same Ir concentration dependence that follows a novel complex, nonmonotonous behavior as compared to previous studies. For small Ir concentrations a signal minimum is observed, whereas a pronounced maximum appears near the equiatomic composition. We identify this behavior as originating from the interplay of different spin Hall mechanisms as well as a concentration-dependent variation of the integrated spin current density in Cu 1-x Ir x . The coinciding results obtained for dc and ultrafast stimuli provide further support that the spin Seebeck effect extends to terahertz frequencies, thus enabling a transfer of established spintronic measurement schemes into the terahertz regime. Our findings also show that the studied material allows for efficient spin-to-charge conversion even on ultrafast time scales.

Facile Quantification and Identification Techniques for Reducing Gases over a Wide Concentration Range Using a MOS Sensor in Temperature-Cycled Operation.

PubMed

Schultealbert, Caroline; Baur, Tobias; Schütze, Andreas; Sauerwald, Tilman

2018-03-01

Dedicated methods for quantification and identification of reducing gases based on model-based temperature-cycled operation (TCO) using a single commercial MOS gas sensor are presented. During high temperature phases the sensor surface is highly oxidized, yielding a significant sensitivity increase after switching to lower temperatures (differential surface reduction, DSR). For low concentrations, the slope of the logarithmic conductance during this low-temperature phase is evaluated and can directly be used for quantification. For higher concentrations, the time constant for reaching a stable conductance during the same low-temperature phase is evaluated. Both signals represent the reaction rate of the reducing gas on the strongly oxidized surface at this low temperature and provide a linear calibration curve, which is exceptional for MOS sensors. By determining these reaction rates on different low-temperature plateaus and applying pattern recognition, the resulting footprint can be used for identification of different gases. All methods are tested over a wide concentration range from 10 ppb to 100 ppm (4 orders of magnitude) for four different reducing gases (CO, H₂, ammonia and benzene) using randomized gas exposures.

Functional importance of short-range binding and long-range solvent interactions in helical antifreeze peptides.

PubMed

Ebbinghaus, Simon; Meister, Konrad; Prigozhin, Maxim B; Devries, Arthur L; Havenith, Martina; Dzubiella, Joachim; Gruebele, Martin

2012-07-18

Short-range ice binding and long-range solvent perturbation both have been implicated in the activity of antifreeze proteins and antifreeze glycoproteins. We study these two mechanisms for activity of winter flounder antifreeze peptide. Four mutants are characterized by freezing point hysteresis (activity), circular dichroism (secondary structure), Förster resonance energy transfer (end-to-end rigidity), molecular dynamics simulation (structure), and terahertz spectroscopy (long-range solvent perturbation). Our results show that the short-range model is sufficient to explain the activity of our mutants, but the long-range model provides a necessary condition for activity: the most active peptides in our data set all have an extended dynamical hydration shell. It appears that antifreeze proteins and antifreeze glycoproteins have reached different evolutionary solutions to the antifreeze problem, utilizing either a few precisely positioned OH groups or a large quantity of OH groups for ice binding, assisted by long-range solvent perturbation. Copyright © 2012 Biophysical Society. Published by Elsevier Inc. All rights reserved.

Activated sludge pilot plant: comparison between experimental and predicted concentration profiles using three different modelling approaches.

PubMed

Le Moullec, Y; Potier, O; Gentric, C; Leclerc, J P

2011-05-01

This paper presents an experimental and numerical study of an activated sludge channel pilot plant. Concentration profiles of oxygen, COD, NO(3) and NH(4) have been measured for several operating conditions. These profiles have been compared to the simulated ones with three different modelling approaches, namely a systemic approach, CFD and compartmental modelling. For these three approaches, the kinetics model was the ASM-1 model (Henze et al., 2001). The three approaches allowed a reasonable simulation of all the concentration profiles except for ammonium for which the simulations results were far from the experimental ones. The analysis of the results showed that the role of the kinetics model is of primary importance for the prediction of activated sludge reactors performance. The fact that existing kinetics parameters in the literature have been determined by parametric optimisation using a systemic model limits the reliability of the prediction of local concentrations and of the local design of activated sludge reactors. Copyright © 2011 Elsevier Ltd. All rights reserved.

Intrinsic vs. spurious long-range memory in high-frequency records of environmental radioactivity - Critical re-assessment and application to indoor 222Rn concentrations from Coimbra, Portugal

NASA Astrophysics Data System (ADS)

Donner, Reik V.; Potirakis, Stelios M.; Barbosa, Susana M.; Matos, Jose A. O.

2015-04-01

The presence or absence of long-range correlations in environmental radioactivity fluctuations has recently attracted considerable interest. Among a multiplicity of practically relevant applications, identifying and disentangling the environmental factors controlling the variable concentrations of the radioactive noble gas Radon is important for estimating its effect on human health and the efficiency of possible measures for reducing the corresponding exposition. In this work, we present a critical re-assessment of a multiplicity of complementary methods that have been previously applied for evaluating the presence of long-range correlations and fractal scaling in environmental Radon variations with a particular focus on the specific properties of the underlying time series. As an illustrative case study, we subsequently re-analyze two high-frequency records of indoor Radon concentrations from Coimbra, Portugal, each of which spans several months of continuous measurements at a high temporal resolution of five minutes. Our results reveal that at the study site, Radon concentrations exhibit complex multi-scale dynamics with qualitatively different properties at different time-scales: (i) essentially white noise in the high-frequency part (up to time-scales of about one hour), (ii) spurious indications of a non-stationary, apparently long-range correlated process (at time scales between hours and one day) arising from marked periodic components probably related to tidal frequencies, and (iii) low-frequency variability indicating a true long-range dependent process, which might be dominated by a response to meteorological drivers. In the presence of such multi-scale variability, common estimators of long-range memory in time series are necessarily prone to fail if applied to the raw data without previous separation of time-scales with qualitatively different dynamics. We emphasize that similar properties can be found in other types of geophysical time series (for

Optimization of free ammonia concentration for nitrite accumulation in shortcut biological nitrogen removal process.

PubMed

Chung, Jinwook; Shim, Hojae; Park, Seong-Jun; Kim, Seung-Jin; Bae, Wookeun

2006-03-01

A shortcut biological nitrogen removal (SBNR) utilizes the concept of a direct conversion of ammonium to nitrite and then to nitrogen gas. A successful SBNR requires accumulation of nitrite in the system and inhibition of the activity of nitrite oxidizers. A high concentration of free ammonia (FA) inhibits nitrite oxidizers, but unfortunately decreases the ammonium removal rate as well. Therefore, the optimal range of FA concentration is necessary not only to stabilize nitrite accumulation but also to achieve maximum ammonium removal. In order to derive such optimal FA concentrations, the specific substrate utilization rates of ammonium and nitrite oxidizers were measured. The optimal FA concentration range appeared to be 5-10 mg/L for the adapted sludge. The simulated results from the modified inhibition model expressed by FA and ammonium/nitrite concentrations were shown very similar to the experimental results.

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.

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.

Physical Activity and Blood Lead Concentration in Korea: Study Using the Korea National Health and Nutrition Examination Survey (2008-2013).

PubMed

Rhie, Jeongbae; Lee, Hye-Eun

2016-06-01

Physical activity normally has a positive influence on health, however it can be detrimental in the presence of air pollution. Lead, a heavy metal with established adverse health effects, is a major air pollutant. We evaluated the correlation between blood lead concentration and physical activity using data collected from the Korea National Health and Nutrition Examination Survey. Multivariate logistic regression analysis was performed after dividing participants according to whether they were in the top 25% in the distribution of blood lead concentration (i.e., ≥ 2.76 µg/dL), with physical activity level as an independent variable and adjusting for factors such as age, sex, drinking, smoking, body mass index, region, and occupation. The high physical activity group had greater odds of having a blood lead concentration higher than 2.76 µg/dL (odds ratio 1.29, 95% CI 1.11-1.51) compared to the low physical activity group. Furthermore, blood lead concentration is correlated with increasing physical activity.

First parity evaluation of peak milk yield for range cows developed in the same ecophysiological system but receiving different concentrations of harvested feed inputs

USDA-ARS?s Scientific Manuscript database

Can range livestock producers reduce harvested feed inputs, during heifer development, and maintain production goals? To address this, we conducted a two year study measuring milk production (kg/d) and milk constituent concentrations (g/d) for 16 primiparous beef cows each year that were born from d...

First parity evaluation of peak milk yield for range cows developed in the same ecophysiological system but receiving different concentrations of harvested feed inputs

USDA-ARS?s Scientific Manuscript database

Reduction of harvested feed inputs during heifer development could optimize range livestock production and improve economic feasibility. The objective for this two year study was to measure milk production (kg/d) and milk constituent concentrations (g/d) for 16 primiparous beef cows each year that w...

Interpreting serum risperidone concentrations.

PubMed

Boerth, Joel M; Caley, Charles F; Goethe, John W

2005-02-01

Risperidone is an atypical antipsychotic commonly used for treatment of schizophrenia and other psychotic disorders. Although therapeutic drug monitoring is not routine for any of the atypical antipsychotics, serum antipsychotic concentrations are measured routinely to assess treatment nonadherence. In humans, risperidone is metabolized by cytochrome P450 2D6 to 9-hydroxyrisperidone; together these constitute the active moiety. Dose-proportional increases in serum concentrations have not been reported for the parent drug, but have been reported for 9-hydroxyrisperidone and the active moiety (i.e., the combined concentrations of risperidone and 9-hydroxyrisperidone). We describe a 34-year-old Caucasian man of Sicilian descent with a history of schizophrenia, disorganized type. He was suspected to be noncompliant with his risperidone therapy. Initially, active moiety risperidone concentrations increased linearly with prescribed dosage increases. However, with continued increases, active moiety concentrations adjusted downward and remained 17-36% below anticipated levels. We propose a method for estimating target active moiety concentrations of risperidone based on dosage-a method that may be used to guide clinicians in assessing nonadherence to risperidone treatment.

Low concentrations of alendronate increase the local invasive potential of osteoblastic sarcoma cell lines via connexin 43 activation.

PubMed

Yoshitani, Kazuhiro; Kido, Akira; Honoki, Kanya; Akahane, Manabu; Fujii, Hiromasa; Tanaka, Yasuhito

2011-07-15

Bisphosphonates (BPs) are agents used for treating disorders of excessive bone resorption. In addition, due to their cell-killing activity, BPs were potent candidates for adjuvant cancer therapy. On the other hand, low-concentrations of BPs have been reported to increase cellular viability in several types of tumor cells. Therefore, we focused on the effect of BPs on cellular aggressiveness of malignant bone tumors at low concentrations. MTS assay was performed using osteosarcoma cell lines MG63 and HOS, fibrosarcoma cell line HT1080, and prostate cancer cell line PC3. All the cell lines showed toxicity at high concentrations. On the other hand, at lower concentrations, the cellular viabilities of HOS and MG63 were rather higher than those of untreated controls. Since this tendency was most evident, HOS was used for further assays, including cellular motility, bone resorption activity, and cathepsin K activity. The low-concentration of alendronate enhanced cellular viability and motility, which correlated with the expression of connexin 43 at the mRNA and protein levels. Interestingly, oleamide, a potent connexin 43 inhibitor, had an inhibitory effect on the enhanced proliferation. Our data suggest that alendronate may enhance the proliferation of osteoblastic cell line through connexin 43 activation. Copyright © 2011 Elsevier GmbH. All rights reserved.

Dynamic simulation of concentrated macromolecular solutions with screened long-range hydrodynamic interactions: Algorithm and limitations

PubMed Central

Ando, Tadashi; Chow, Edmond; Skolnick, Jeffrey

2013-01-01

Hydrodynamic interactions exert a critical effect on the dynamics of macromolecules. As the concentration of macromolecules increases, by analogy to the behavior of semidilute polymer solutions or the flow in porous media, one might expect hydrodynamic screening to occur. Hydrodynamic screening would have implications both for the understanding of macromolecular dynamics as well as practical implications for the simulation of concentrated macromolecular solutions, e.g., in cells. Stokesian dynamics (SD) is one of the most accurate methods for simulating the motions of N particles suspended in a viscous fluid at low Reynolds number, in that it considers both far-field and near-field hydrodynamic interactions. This algorithm traditionally involves an O(N3) operation to compute Brownian forces at each time step, although asymptotically faster but more complex SD methods are now available. Motivated by the idea of hydrodynamic screening, the far-field part of the hydrodynamic matrix in SD may be approximated by a diagonal matrix, which is equivalent to assuming that long range hydrodynamic interactions are completely screened. This approximation allows sparse matrix methods to be used, which can reduce the apparent computational scaling to O(N). Previously there were several simulation studies using this approximation for monodisperse suspensions. Here, we employ newly designed preconditioned iterative methods for both the computation of Brownian forces and the solution of linear systems, and consider the validity of this approximation in polydisperse suspensions. We evaluate the accuracy of the diagonal approximation method using an intracellular-like suspension. The diffusivities of particles obtained with this approximation are close to those with the original method. However, this approximation underestimates intermolecular correlated motions, which is a trade-off between accuracy and computing efficiency. The new method makes it possible to perform large-scale and

Measurement of the total activity concentrations of Libyan oil scale

NASA Astrophysics Data System (ADS)

Da Silva, F. C. A.; Bradley, D. A.; Regan, P. H.; Rozaila, Z. Siti

2017-08-01

Twenty-three oil scale samples obtained from the Libyan oil and gas industry production facilities onshore have been measured using high-resolution gamma-ray spectrometry with a shielded HPGe detector, the work being carried out within the Environmental Radioactivity Laboratory at the University of Surrey. The main objectives of this work were to determine the extent to which the predominant radionuclides associated with the uranium and thorium natural decay chains were in secular equilibrium with their decay progeny, also to compare differences between the total activity concentrations (TAC) in secular equilibrium and disequilibrium and to evaluate the measured activities for the predominant gamma-ray emitting decay radionuclides within the 232Th and 238U chains. The oil scale NORM samples did not exhibit radioactive equilibrium between the decay progeny and longer-lived parent radionuclides of the 238U and 232Th series.

New criteria for measuring range management activities.

Treesearch

T.M. Quigley; D.S. Dillard; J.B. [and others] Reese

1989-01-01

The USDA Forest Service national range program is currently evaluating its information needs at the national level A Range Measurement Task Group of Agency personnel was assembled in January 1988 to evaluate the information needs and recommend appropriate measures and reports. This document is the final recommendation of the task group. The recommendation includes...

Estimating concentrations of fine-grained and total suspended sediment from close-range remote sensing imagery

USGS Publications Warehouse

Mosbrucker, Adam; Spicer, Kurt R.; Christianson, Tami; Uhrich, Mark A.

2015-01-01

data range among sensors. Of greatest interest to many programs is a hysteresis in the relationship between turbidity and SSC, attributed to temporal variation of particle size distribution (Landers and Sturm, 2013; Uhrich et al., 2014). This phenomenon causes increased uncertainty in regression-estimated values of SSC, due to changes in nephelometric reflectance off the varying grain sizes in suspension (Uhrich et al., 2014). Here, we assess the feasibility and application of close-range remote sensing to quantify SSC and particle size distribution of a disturbed, and highly-turbid, river system. We use a consumer-grade digital camera to acquire imagery of the river surface and a depth-integrating sampler to collect concurrent suspended-sediment samples. We then develop two empirical linear regression models to relate image spectral information to concentrations of fine sediment (clay to silt) and total suspended sediment. Before presenting our regression model development, we briefly summarize each data-acquisition method.

Interlaboratory comparability of serum cotinine measurements at smoker and nonsmoker concentration levels: A round-robin study

PubMed Central

Jacob, Peyton; Holiday, David B.; Benowitz, Neal L.; Sosnoff, Connie S.; Doig, Mira V.; Feyerabend, Colin; Aldous, Kenneth M.; Sharifi, Mehran; Kellogg, Mark D.; Langman, Loralie J.

2009-01-01

Introduction: Cotinine, the primary proximate metabolite of nicotine, is commonly measured as an index of exposure to tobacco in both active users of tobacco and nonsmokers with possible exposure to secondhand smoke (SHS). A number of laboratories have implemented analyses for measuring serum cotinine in recent years, but there have been few interlaboratory comparisons of the results. Among nonsmokers exposed to SHS, the concentration of cotinine in blood can be quite low, and extensive variability in these measurements has been reported in the past. Methods: In this study, a group of seven laboratories, all experienced in serum cotinine analysis, measured eight coded serum pools with concentrations ranging from background levels of about 0.05 ng/ml to relatively high concentrations in the active smokers range. All laboratories used either gas–liquid chromatography with nitrogen–phosphorus detection or liquid chromatography with mass spectrometric detection. Results: All seven laboratories reliably measured the cotinine concentrations in samples that were within the range of their methods. In each case, the results for the pools were correctly ranked in order, and no significant interlaboratory bias was observed at the 5% level of significance for results from any of the pools. Discussion: We conclude that present methods of chromatographic analysis of serum cotinine, as used by these experienced laboratories, are capable of providing accurate and precise results in both the smoker and the nonsmoker concentration range. PMID:19933777

Effects of taurine on plasma glucose concentration and active glucose transport in the small intestine.

PubMed

Tsuchiya, Yo; Kawamata, Koichi

2017-11-01

Taurine lowers blood glucose levels and improves hyperglycemia. However, its effects on glucose transport in the small intestine have not been investigated. Here, we elucidated the effect of taurine on glucose absorption in the small intestine. In the oral glucose tolerance test, addition of 10 mmol/L taurine suppressed the increase in hepatic portal glucose concentrations. To investigate whether the suppressive effect of taurine occurs via down-regulation of active glucose transport in the small intestine, we performed an assay using the everted sac of the rat jejunum. Addition of taurine to the mucosal side of the jejunum suppressed active glucose transport via sodium-glucose cotransporter 1 (SGLT1). After elimination of chloride ions from the mucosal solution, taurine did not show suppressive effects on active glucose transport. These results suggest that taurine suppressed the increase in hepatic portal glucose concentrations via suppression of SGLT1 activity in the rat jejunum, depending on chloride ions. © 2017 Japanese Society of Animal Science.

The temperature dependence of the BK channel activity - kinetics, thermodynamics, and long-range correlations.

PubMed

Wawrzkiewicz-Jałowiecka, Agata; Dworakowska, Beata; Grzywna, Zbigniew J

2017-10-01

Large-conductance, voltage dependent, Ca 2+ -activated potassium channels (BK) are transmembrane proteins that regulate many biological processes by controlling potassium flow across cell membranes. Here, we investigate to what extent temperature (in the range of 17-37°C with ΔT=5°C step) is a regulating parameter of kinetic properties of the channel gating and memory effect in the series of dwell-time series of subsequent channel's states, at membrane depolarization and hyperpolarization. The obtained results indicate that temperature affects strongly the BK channels' gating, but, counterintuitively, it exerts no effect on the long-range correlations, as measured by the Hurst coefficient. Quantitative differences between dependencies of appropriate channel's characteristics on temperature are evident for different regimes of voltage. Examining the characteristics of BK channel activity as a function of temperature allows to estimate the net activation energy (E act ) and changes of thermodynamic parameters (ΔH, ΔS, ΔG) by channel opening. Larger E act corresponds to the channel activity at membrane hyperpolarization. The analysis of entropy and enthalpy changes of closed to open channel's transition suggest the entropy-driven nature of the increase of open state probability during voltage activation and supports the hypothesis about the voltage-dependent geometry of the channel vestibule. Copyright © 2017 Elsevier B.V. All rights reserved.

Radionuclide activity concentrations in forest surface fuels at the Savannah River site

Treesearch

Anna M. Hejl; Roger D. Ottmar; G. Timothy Jannik; Teresa P. Eddy; Stephen I. Rathbun; Adwoa A. Commodore; John L. Pearce; Luke P. Naeler

2013-01-01

A study was undertaken at the United States Department of Energy's Savannah River Site (SRS), Aiken, South Carolina to investigate radionuclide activity concentrations in litter and duff from select areas at SRS. Litter (i.e., vegetative debris) and duff (i.e., highly decomposed vegetative debris) can often be the major fuels consumed during prescribed burns and...

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.

Effects of chlordecone on 20-hydroxyecdysone concentration and chitobiase activity in a decapod crustacean, Macrobrachium rosenbergii.

PubMed

Lafontaine, Anne; Gismondi, Eric; Boulangé-Lecomte, Céline; Geraudie, Perrine; Dodet, Nathalie; Caupos, Fanny; Lemoine, Soazig; Lagadic, Laurent; Thomé, Jean-Pierre; Forget-Leray, Joëlle

2016-07-01

Chlordecone (CLD) is an organochlorine insecticide abundant in aquatic environment of the French West Indies. However, few studies have investigated its impact on freshwater invertebrates. Whereas CLD is suspected of inducing endocrine disruption, this work aimed to study the effects of environmentally relevant concentrations of CLD on the 20-hydroxyecdysone (20-HE) hormone concentration and on the chitobiase activity, both having key roles in the molting process of crustaceans. In addition, the bioaccumulation of CLD was measured in the muscle tissue of Macrobrachium rosenbergii to underline potential dose-response relationship. The results have shown that CLD was bioaccumulated in exposed organisms according to a trend to a dose-response relationship. Moreover, it was observed that CLD decreased the 20-HE concentration in exposed prawns when compared to control, whatever the duration of exposure, as well as it inhibited the chitobiase activity after 30days of exposure. The present study indicates that CLD could interfere with molting process of M. rosenbergii by disturbing the 20-HE concentration and the activity of chitobiase, suggesting consequences at the long term on the shrimp development. This study also confirmed that CLD could be an endocrine disruptor in decapod crustaceans, as it was already observed in vertebrates. Copyright © 2016 Elsevier B.V. All rights reserved.

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.

Quantifying activation of perfluorocarbon-based phase-change contrast agents using simultaneous acoustic and optical observation.

PubMed

Li, Sinan; Lin, Shengtao; Cheng, Yi; Matsunaga, Terry O; Eckersley, Robert J; Tang, Meng-Xing

2015-05-01

Phase-change contrast agents in the form of nanoscale droplets can be activated into microbubbles by ultrasound, extending the contrast beyond the vasculature. This article describes simultaneous optical and acoustical measurements for quantifying the ultrasound activation of phase-change contrast agents over a range of concentrations. In experiments, decafluorobutane-based nanodroplets of different dilutions were sonicated with a high-pressure activation pulse and two low-pressure interrogation pulses immediately before and after the activation pulse. The differences between the pre- and post-interrogation signals were calculated to quantify the acoustic power scattered by the microbubbles activated over a range of droplet concentrations. Optical observation occurred simultaneously with the acoustic measurement, and the pre- and post-microscopy images were processed to generate an independent quantitative indicator of the activated microbubble concentration. Both optical and acoustic measurements revealed linear relationships to the droplet concentration at a low concentration range <10(8)/mL when measured at body temperature. Further increases in droplet concentration resulted in saturation of the acoustic interrogation signal. Compared with body temperature, room temperature was found to produce much fewer and larger bubbles after ultrasound droplet activation. Copyright © 2015. Published by Elsevier Inc.

Studies on Arabidopsis athak5, atakt1 double mutants disclose the range of concentrations at which AtHAK5, AtAKT1 and unknown systems mediate K uptake.

PubMed

Rubio, Francisco; Alemán, Fernando; Nieves-Cordones, Manuel; Martínez, Vicente

2010-06-01

The high-affinity K(+) transporter AtHAK5 and the inward-rectifier K(+) channel AtAKT1 have been described to contribute to K(+) uptake in Arabidopsis thaliana. Studies with T-DNA insertion lines showed that both systems participate in the high-affinity range of concentrations and only AtAKT1 in the low-affinity range. However the contribution of other systems could not be excluded with the information and plant material available. The results presented here with a double knock-out athak5, atakt1 mutant show that AtHAK5 is the only system mediating K(+) uptake at concentrations below 0.01 mM. In the range between 0.01 and 0.05 mM K(+) AtHAK5 and AtAKT1 are the only contributors to K(+) acquisition. At higher K(+) concentrations, unknown systems come into operation and participate together with AtAKT1 in low-affinity K(+) uptake. These systems can supply sufficient K(+) to promote plant growth even in the absence of AtAKT1 or in the presence of 10 mM K(+) where AtAKT1 is not essential.

Serum and urine concentrations of trypsinogen-activation peptide as markers for acute pancreatitis in cats

PubMed Central

Allen, Heidi S.; Steiner, Jörg; Broussard, John; Mansfield, Caroline; Williams, David A.; Jones, Boyd

2006-01-01

The purpose of this study was to compare the clinical utility of the serum concentration of feline trypsin-like immunoreactivity (fTLI), the plasma and urine concentrations of trypsinogen-activation peptide (TAP), and the ratio of the urine TAP and creatinine concentrations (TAP:Cr) in the diagnosis of feline acute pancreatitis. We used 13 healthy cats and 10 cats with a diagnosis of acute pancreatitis. The mean serum fTLI and plasma TAP concentrations were significantly higher in the cats with acute pancreatitis than in the healthy cats (P < 0.05); the mean urine TAP concentrations and the median urine TAP:Cr ratios were not significantly different. Among the cats examined in this study, there was no benefit of plasma TAP over serum fTLI in the evaluation of suspected acute pancreatitis. PMID:17042387

Ranging, Activity and Habitat Use by Tigers in the Mangrove Forests of the Sundarban.

PubMed

Naha, Dipanjan; Jhala, Yadvendradev V; Qureshi, Qamar; Roy, Manjari; Sankar, Kalyansundaram; Gopal, Rajesh

2016-01-01

The Sundarban of India and Bangladesh (about 6000 km²) are the only mangrove forests inhabited by a sizeable population of tigers. The adjoining area also supports one of the highest human densities and experiences severe human-tiger conflicts. We used GPS-Satellite and VHF radio-collars on 6 (3 males and 3 female) tigers to study their ranging patterns and habitat preference. The average home range (95% Fixed Kernel) for resident females was 56.4 (SE 5.69) and for males it was 110 (SE 49) km². Tigers crossed an average of 5 water channels > 30 meters per day with a mean width of 54 meters, whereas channels larger than 400 meters were rarely crossed. Tigers spent over 58% of their time within Phoenix habitat but compositional analysis showed a habitat preference of the order Avicennia-Sonneratia > Phoenix > Ceriops > Barren > Water. Average daily distance moved was 4.6 km (range 0.1-23). Activity of tigers peaked between 05:00 hours and 10:00 hours showing some overlap with human activity. Territory boundaries were demarcated by large channels which tigers intensively patrolled. Extra caution should be taken while fishing or honey collection during early morning in Avicennia-Sonneratia and Phoenix habitat types along wide channels to reduce human-tiger conflict. Considering home-range core areas as exclusive, tiger density was estimated at 4.6 (SE range 3.6 to 6.7) tigers/100 km2 giving a total population of 76 (SE range 59-110) tigers in the Indian Sundarban. Reluctance of tigers to cross wide water channels combined with increasing commercial boat traffic and sea level rise due to climate change pose a real threat of fragmenting the Sundarban tiger population.

Ranging, Activity and Habitat Use by Tigers in the Mangrove Forests of the Sundarban

PubMed Central

Naha, Dipanjan; Jhala, Yadvendradev V.; Qureshi, Qamar; Roy, Manjari; Sankar, Kalyansundaram; Gopal, Rajesh

2016-01-01

The Sundarban of India and Bangladesh (about 6000 km²) are the only mangrove forests inhabited by a sizeable population of tigers. The adjoining area also supports one of the highest human densities and experiences severe human-tiger conflicts. We used GPS-Satellite and VHF radio-collars on 6 (3 males and 3 female) tigers to study their ranging patterns and habitat preference. The average home range (95% Fixed Kernel) for resident females was 56.4 (SE 5.69) and for males it was 110 (SE 49) km². Tigers crossed an average of 5 water channels > 30 meters per day with a mean width of 54 meters, whereas channels larger than 400 meters were rarely crossed. Tigers spent over 58% of their time within Phoenix habitat but compositional analysis showed a habitat preference of the order Avicennia-Sonneratia > Phoenix > Ceriops > Barren > Water. Average daily distance moved was 4.6 km (range 0.1–23). Activity of tigers peaked between 05:00 hours and 10:00 hours showing some overlap with human activity. Territory boundaries were demarcated by large channels which tigers intensively patrolled. Extra caution should be taken while fishing or honey collection during early morning in Avicennia-Sonneratia and Phoenix habitat types along wide channels to reduce human-tiger conflict. Considering home-range core areas as exclusive, tiger density was estimated at 4.6 (SE range 3.6 to 6.7) tigers/100 km2 giving a total population of 76 (SE range 59–110) tigers in the Indian Sundarban. Reluctance of tigers to cross wide water channels combined with increasing commercial boat traffic and sea level rise due to climate change pose a real threat of fragmenting the Sundarban tiger population. PMID:27049644

Effects of temperature and sodium chloride concentration on the activities of proteases and amylases in soy sauce koji.

PubMed

Su, Nan-Wei; Wang, Mei-Ling; Kwok, Kam-Fu; Lee, Min-Hsiung

2005-03-09

This study investigated the effects of temperature and sodium chloride concentration on the proteolytic and amylolytic activities of soy sauce koji. The optimal temperatures for both protease and amylase were found in the range of 50-55 degrees C. The protease was not stable at 55 degrees C and retained only approximately 20% residual activity after incubation at 55 degrees C for 4 h. The protease was labile in sodium chloride solution, whereas the amylase was quite stable. The residual protease activity in an 18% NaCl solution was only approximately 3%. The harvested koji was mixed with 1.5 volumes of water (v/w) and incubated at 45 degrees C for 48 h; the total nitrogen and amino nitrogen contents were 1.3 and 0.56%, respectively. The results indicated that the hydrolysis of koji at the critical temperature of 45 degrees C could be employed as a rapid fermentation method to reduce the time for soy sauce manufacturing. According to this study, the combination of 5% sodium chloride and fermentation at 45 degrees C was considered as the best condition for the prohydrolysis of koji for making soy sauce. In addition, the critical temperature of 45 degrees C was very important when used in the preparation of protein hydrolysates for the flavoring industry and for the preparation of biologically active peptides.

CCN and IN concentration measurements during the Antarctic Circumnavigation Expedition

NASA Astrophysics Data System (ADS)

Stratmann, F.; Henning, S.; Löffler, M.; Welti, A.; Hartmann, M.; Wernli, H.; Baccarini, A.; Schmale, J.

2017-12-01

Cloud condensation nuclei (CCN) and ice nuclei (IN) concentrations measured during the Antarctic Circumnavigation Expedition (ACE) within the Study of Preindustrial-like Aerosol-Climate Effects (SPACE) are presented. The measurements give a circumpolar transect through the Sub Antarctic Ocean, where existing measurements are scarce. ACE took place during the austral summer 2016/17 and included exploration of different environments from pristine open Ocean to Antarctic islands and the southernmost ports of the 3 surrounding continents. CCN concentrations are measured over the entire range of expected in-cloud supersaturations from 0.1 to 1% using a CCNc instrument from DMT. IN concentrations are determined from filter samples at water saturated conditions from -5°C to -25°C, covering common temperatures of mixed-phase cloud glaciation. The sensitivity of measured IN and CCN concentrations to meteorological parameters, activity of marine biology and location is assessed to gain insight into potential sources of CCN and IN. Back trajectory modelling is used to allocate regional variations to aerosol sources originating in the marine boundary layer or long-range transport. The gained datasets constrain CCN and IN concentrations in the marine boundary layer along the cruise track. The comprehensive set of parallel measured parameters during ACE allow to evaluate contributions of local ocean-surface sources versus long-range transport to Sub-Antarctic CCN and IN. The measurements can be used as input to climate models, e.g. pristine Sub Antarctic conditions can provide an approximation for a pre-industrial environment.

Effect of Concentration of Collagen Gel on Functional Activity of Bone Marrow Mesenchymal Stromal Cells.

PubMed

Nashchekina, Yu A; Yudintceva, N M; Nikonov, P O; Ivanova, E A; Smagina, L V; Voronkina, I V

2017-05-01

Collagen I gels with protein concentrations of 1, 2, and 3.5 mg/ml were prepared and embedded in a porous polylactide scaffold to reduce their contraction. Concentration of the gel did not affect its degradation. Collagen gels promoted the formation of cell networks. The cells in the collagen gel with a concentration of 1 mg/ml embedded in polylactide scaffold had elongated spindle-like shape, in contrast to flattened cells in collagen gel of the same concentration not embedded in the scaffold. Stabilization of the collagen gel in the polylactide scaffold promoted active synthesis of laminin and fibronectin by cells as soon as on day 5 of culturing in comparison with that in free collagen substrate.

Arm position influences the activation patterns of trunk muscles during trunk range-of-motion movements.

PubMed

Siu, Aaron; Schinkel-Ivy, Alison; Drake, Janessa Dm

2016-10-01

To understand the activation patterns of the trunk musculature, it is also important to consider the implications of adjacent structures such as the upper limbs, and the muscles that act to move the arms. This study investigated the effects of arm positions on the activation patterns and co-activation of the trunk musculature and muscles that move the arm during trunk range-of-motion movements (maximum trunk axial twist, flexion, and lateral bend). Fifteen males and fifteen females, asymptomatic for low back pain, performed maximum trunk range-of-motion movements, with three arm positions for axial twist (loose, crossed, abducted) and two positions for flexion and lateral bend (loose, crossed). Electromyographical data were collected for eight muscles bilaterally, and activation signals were cross-correlated between trunk muscles and the muscles that move the arms (upper trapezius, latissimus dorsi). Results revealed consistently greater muscle co-activation (higher cross-correlation coefficients) between the trunk muscles and upper trapezius for the abducted arm position during maximum trunk axial twist, while results for the latissimus dorsi-trunk pairings were more dependent on the specific trunk muscles (either abdominal or back) and latissimus dorsi muscle (either right or left side), as well as the range-of-motion movement. The findings of this study contribute to the understanding of interactions between the upper limbs and trunk, and highlight the influence of arm positions on the trunk musculature. In addition, the comparison of the present results to those of individuals with back or shoulder conditions may ultimately aid in elucidating underlying mechanisms or contributing factors to those conditions. Copyright © 2016 Elsevier B.V. All rights reserved.

Comparison of two estimation methods for surface area concentration using number concentration and mass concentration of combustion-related ultrafine particles

NASA Astrophysics Data System (ADS)

Park, Ji Young; Raynor, Peter C.; Maynard, Andrew D.; Eberly, Lynn E.; Ramachandran, Gurumurthy

Recent research has suggested that the adverse health effects caused by nanoparticles are associated with their surface area (SA) concentrations. In this study, SA was estimated in two ways using number and mass concentrations and compared with SA (SA meas) measured using a diffusion charger (DC). Aerosol measurements were made twice: once starting in October 2002 and again starting in December 2002 in Mysore, India in residences that used kerosene or liquefied petroleum gas (LPG) for cooking. Mass, number, and SA concentrations and size distributions by number were measured in each residence. The first estimation method (SA PSD) used the size distribution by number to estimate SA. The second method (SA INV) used a simple inversion scheme that incorporated number and mass concentrations while assuming a lognormal size distribution with a known geometrical standard deviation. SA PSD was, on average, 2.4 times greater (range = 1.6-3.4) than SA meas while SA INV was, on average, 6.0 times greater (range = 4.6-7.7) than SA meas. The logarithms of SA PSD and SA INV were found to be statistically significant predictors of the logarithm of SA meas. The study showed that particle number and mass concentration measurements can be used to estimate SA with a correction factor that ranges between 2 and 6.

Marine and freshwater concentration ratios (CR(wo-water)): review of Japanese data.

PubMed

Tagami, K; Uchida, S

2013-12-01

The water-to-organism (whole body) concentration ratio (CR(wo-water)), which is defined as the ratio of the concentration of a radionuclide in the biota (Bq kg(-1) fresh weight) to that in water (Bq L(-1)), has been used in mathematical models for environmental radiation protection. In the present paper, published global fallout (90)Sr, (137)Cs, (106)Ru, (144)Ce and (239+240)Pu activity concentration data and stable element concentration data for Na, K, Ca, Mg, Fe, Cu and Mn for organisms living in freshwater or seawater areas in Japan were collated. The data suitable for obtaining CR(wo-water) values were identified. CR(wo-water) values of (137)Cs were similar for pelagic fish, benthic fish and whitebait (immature, small fish) with respective geometric means of 30 (range: 4.4-69), 32 (range: 15-54) and 33 (range: 13-84). The calculated CR(wo-water) values of the other radionuclides and stable elements were generally similar to other previously reported values; with the exception that those for Ce were lower for marine biota and those of Cu were higher for freshwater fish. Copyright © 2012 Elsevier Ltd. All rights reserved.

Uranium-238 and thorium-232 series concentrations in soil, radon-222 indoor and drinking water concentrations and dose assessment in the city of Aldama, Chihuahua, Mexico.

PubMed

Colmenero Sujo, L; Montero Cabrera, M E; Villalba, L; Rentería Villalobos, M; Torres Moye, E; García León, M; García-Tenorio, R; Mireles García, F; Herrera Peraza, E F; Sánchez Aroche, D

2004-01-01

High-resolution gamma spectrometry was used to determine the concentration of 40K, 238U and 232Th series in soil samples taken from areas surrounding the city of Aldama, in Chihuahua. Results of indoor air short-time sampling, with diffusion barrier charcoal detectors, revealed relatively high indoor radon levels, ranging from 29 to 422 Bq/m3; the radon concentrations detected exceeded 148 Bq/m3 in 76% of the homes tested. Additionally, liquid scintillation counting showed concentrations of radon in drinking water ranging from 4.3 to 42 kBq/m3. The high activity of 238U in soil found in some places may be a result of the uranium milling process performed 20 years ago in the area. High radon concentrations indoor and in water may be explained by assuming the presence of uranium-bearing rocks underneath of the city, similar to a felsic dike located near Aldama. The estimated annual effective dose of gamma radiation from the soil and radon inhalation was 3.83 mSv.

Low concentration of arsenite exacerbates UVR-induced DNA strand breaks by inhibiting PARP-1 activity

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

Qin Xujun; Department of Toxicology, Fourth Military Medical University, Xi'an, Shaanxi, 710032; Hudson, Laurie G.

2008-10-01

Epidemiological studies have associated arsenic exposure with many types of human cancers. Arsenic has also been shown to act as a co-carcinogen even at low concentrations. However, the precise mechanism of its co-carcinogenic action is unknown. Recent studies indicate that arsenic can interfere with DNA-repair processes. Poly(ADP-ribose) polymerase (PARP)-1 is a zinc-finger DNA-repair protein, which can promptly sense DNA strand breaks and initiate DNA-repair pathways. In the present study, we tested the hypothesis that low concentrations of arsenic could inhibit PAPR-1 activity and so exacerbate levels of ultraviolet radiation (UVR)-induced DNA strand breaks. HaCat cells were treated with arsenite and/ormore » UVR, and then DNA strand breaks were assessed by comet assay. Low concentrations of arsenite ({<=} 2 {mu}M) alone did not induce significant DNA strand breaks, but greatly enhanced the DNA strand breaks induced by UVR. Further studies showed that 2 {mu}M arsenite effectively inhibited PARP-1 activity. Zinc supplementation of arsenite-treated cells restored PARP-1 activity and significantly diminished the exacerbating effect of arsenite on UVR-induced DNA strand breaks. Importantly, neither arsenite treatment, nor zinc supplementation changed UVR-triggered reactive oxygen species (ROS) formation, suggesting that their effects upon UVR-induced DNA strand breaks are not through a direct free radical mechanism. Combination treatments of arsenite with PARP-1 inhibitor 3-aminobenzamide or PARP-1 siRNA demonstrate that PARP-1 is the target of arsenite. Together, these findings show that arsenite at low concentration exacerbates UVR-induced DNA strand breaks by inhibiting PARP-1 activity, which may represent an important mechanism underlying the co-carcinogenicity of arsenic.« less

Long-range tertiary interactions in single hammerhead ribozymes bias motional sampling toward catalytically active conformations

PubMed Central

McDowell, S. Elizabeth; Jun, Jesse M.; Walter, Nils G.

2010-01-01

Enzymes generally are thought to derive their functional activity from conformational motions. The limited chemical variation in RNA suggests that such structural dynamics may play a particularly important role in RNA function. Minimal hammerhead ribozymes are known to cleave efficiently only in ∼10-fold higher than physiologic concentrations of Mg2+ ions. Extended versions containing native loop–loop interactions, however, show greatly enhanced catalytic activity at physiologically relevant Mg2+ concentrations, for reasons that are still ill-understood. Here, we use Mg2+ titrations, activity assays, ensemble, and single molecule fluorescence resonance energy transfer (FRET) approaches, combined with molecular dynamics (MD) simulations, to ask what influence the spatially distant tertiary loop–loop interactions of an extended hammerhead ribozyme have on its structural dynamics. By comparing hammerhead variants with wild-type, partially disrupted, and fully disrupted loop–loop interaction sequences we find that the tertiary interactions lead to a dynamic motional sampling that increasingly populates catalytically active conformations. At the global level the wild-type tertiary interactions lead to more frequent, if transient, encounters of the loop-carrying stems, whereas at the local level they lead to an enrichment in favorable in-line attack angles at the cleavage site. These results invoke a linkage between RNA structural dynamics and function and suggest that loop–loop interactions in extended hammerhead ribozymes—and Mg2+ ions that bind to minimal ribozymes—may generally allow more frequent access to a catalytically relevant conformation(s), rather than simply locking the ribozyme into a single active state. PMID:20921269

Facile Quantification and Identification Techniques for Reducing Gases over a Wide Concentration Range Using a MOS Sensor in Temperature-Cycled Operation

PubMed Central

Schultealbert, Caroline; Baur, Tobias; Schütze, Andreas; Sauerwald, Tilman

2018-01-01

Dedicated methods for quantification and identification of reducing gases based on model-based temperature-cycled operation (TCO) using a single commercial MOS gas sensor are presented. During high temperature phases the sensor surface is highly oxidized, yielding a significant sensitivity increase after switching to lower temperatures (differential surface reduction, DSR). For low concentrations, the slope of the logarithmic conductance during this low-temperature phase is evaluated and can directly be used for quantification. For higher concentrations, the time constant for reaching a stable conductance during the same low-temperature phase is evaluated. Both signals represent the reaction rate of the reducing gas on the strongly oxidized surface at this low temperature and provide a linear calibration curve, which is exceptional for MOS sensors. By determining these reaction rates on different low-temperature plateaus and applying pattern recognition, the resulting footprint can be used for identification of different gases. All methods are tested over a wide concentration range from 10 ppb to 100 ppm (4 orders of magnitude) for four different reducing gases (CO, H2, ammonia and benzene) using randomized gas exposures. PMID:29494545

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

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

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

2010-07-07

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

A real-time bioluminescent HTS method for measuring protein kinase activity influenced neither by ATP concentration nor by luciferase inhibition.

PubMed

Lundin, Arne; Eriksson, Jonas

2008-08-01

The firefly luciferin-luciferase reaction has been used to set up an assay for protein kinase based on measuring ATP consumption rate as the first-order rate constant for the kinase reaction. The assay obviates the problems encountered with previous bioluminescent protein kinase assays such as interference with the luciferase reaction from library compounds, nonlinear standard curves, and limited dynamic ranges. In the assay described in the present paper luciferase and luciferin are present during the entire kinase reaction, and the light emission can be measured continuously. In an HTS situation the light emission is measured only twice, i.e., initially and after a predetermined time. After a fivefold reduction of the ATP concentration a Z' value of 0.96 was obtained. Light emission data from samples with kinase are normalized with light emission data from blanks without kinase. First-order rate constants for the kinase reaction calculated from normalized light emission are not affected by a moderate degree of inactivation of luciferase and luciferin during the measuring time. The constants have the same value at all ATP concentrations much lower than the K(m) of the luciferase and the kinase. These factors make the assay very robust and influenced neither by ATP concentration nor by luciferase inhibition. The measuring time depends on the kinase activity and can be varied from minutes to more than 8 h provided the kinase is stable and the evaporation of water from the wells is acceptable. The assay is linear with respect to kinase activity over three orders of magnitude. The new reagents also allowed us to determine K(m) values for ATP and for Kemptide.

Radionuclide activities and metal concentrations in sediments of the Sebou Estuary, NW Morocco, following a flooding event.

PubMed

Laissaoui, A; Mas, J L; Hurtado, S; Ziad, N; Villa, M; Benmansour, M

2013-06-01

This study presents metal concentrations (Fe, Mg, Mn, Co, Cu, Zn, Pb, As, Sr and V) and radionuclide activities ((40)K, (137)Cs, (210)Pb, (226)Ra, (228)Ac, (234)Th and (212)Pb) in surface deposits and a sediment core from the Sebou Estuary, Northwest Morocco. Samples were collected in April 2009, about 2 months after a flooding event, and analysed using a well-type coaxial gamma-ray detector and inductively coupled plasma-quadrupole mass spectrometry. Activities of radionuclides and concentrations of almost all elements in surface samples displayed only moderate spatial variation, suggesting homogenous deposition of eroded local soil in response to intense precipitation. Excess (210)Pb displayed relatively constant activity throughout the sediment core, preventing dating and precluding determination of the historical accumulation rates of pollutants at the core site. Some elements showed non-systematic trends with depth and displayed local maxima and minima. Other elements presented relatively systematic concentration trends or relatively constant levels with discrete maxima and/or minima. Except for Mn, Sr and Cr, all metal concentrations in sediment were below levels typical of polluted systems, suggesting little human impact or losses of metals from sediment particles.

Physiological epidermal growth factor concentrations activate high affinity receptors to elicit calcium oscillations.

PubMed

Marquèze-Pouey, Béatrice; Mailfert, Sébastien; Rouger, Vincent; Goaillard, Jean-Marc; Marguet, Didier

2014-01-01

Signaling mediated by the epidermal growth factor (EGF) is crucial in tissue development, homeostasis and tumorigenesis. EGF is mitogenic at picomolar concentrations and is known to bind its receptor on high affinity binding sites depending of the oligomerization state of the receptor (monomer or dimer). In spite of these observations, the cellular response induced by EGF has been mainly characterized for nanomolar concentrations of the growth factor, and a clear definition of the cellular response to circulating (picomolar) concentrations is still lacking. We investigated Ca2+ signaling, an early event in EGF responses, in response to picomolar doses in COS-7 cells where the monomer/dimer equilibrium is unaltered by the synthesis of exogenous EGFR. Using the fluo5F Ca2+ indicator, we found that picomolar concentrations of EGF induced in 50% of the cells a robust oscillatory Ca2+ signal quantitatively similar to the Ca2+ signal induced by nanomolar concentrations. However, responses to nanomolar and picomolar concentrations differed in their underlying mechanisms as the picomolar EGF response involved essentially plasma membrane Ca2+ channels that are not activated by internal Ca2+ store depletion, while the nanomolar EGF response involved internal Ca2+ release. Moreover, while the picomolar EGF response was modulated by charybdotoxin-sensitive K+ channels, the nanomolar response was insensitive to the blockade of these ion channels.

Na-KATPase activity and intracellular ion concentrations in the lactating guinea pig mammary gland. Studies on Na-K activated adenosine triphosphatase, XXXVI.

PubMed

Vreeswijk, J H; de Pont, J J; Bonting, S L

1975-01-01

The intracellular sodium, potassium and chloride concentrations in slices of lactating guinea pig mammary gland have been determined by chemical analysis and the use of appropriate values for extracellular space. These ion concentrations after 1 hr incubation at 37 degrees C in a Krebs-Ringer bicarbonate solution are 45mM Na+, 138 mM K+ and 44 mM Cl-, which values are in agreement with those found in fresh mammary gland slices. Inhibition of the NaK activated ATPase cation pump system of the tissue by 10(-4)M ouabain, anoxia or cooling to 0 degrees C Causes a gain of Na+ and an equimolar loss of K+ without a significant change in chloride concentration. The effect of cooling (0 degrees C) is reversible by reincubation at 37 degrees C. Water content of the tissue (76.5% of wet weight) and extracellular space (40.5%) do not change under these conditions. The results permit the conclusion that the NaK activated ATPase system is responsible for the maintenance of the intracellular Na+ and K+ concentrations, but do not support the presence of a chloride pump.

[Effects of different concentrations of nitrogen and phosphorus on growth and active components of Salvia miltiorrhiza].

PubMed

Xia, Gui-Hui; Wang, Qiu-Ling; Wang, Wen-Quan; Hou, Jun-Ling; Song, Qing-Yan; Luo, Lin; Zhang, Dou-Dou; Yang, Xiang

2016-11-01

With annual Salvia miltiorrhiza seedlings as experimental material, using "3414" optimal regression design recommended by the Ministry of Agriculture and regularly watered with nutrient solution, through the dynamic sampling of S. miltiorrhiza in different growing stages, and the growth index, dry weight of plant root and content of active components were measured. The potted experiments were applied to study the effects of different nitrogen and phosphorus ratios on the growth, dry matter accumulation and accumulation of active components of S. miltiorrhiza, in order to explore a compatible fertilization method of nitrogen and phosphorus ratio that are suitable for production and quality of S. miltiorrhiza. The results reported as follows：①High concentrations of nitrogen fertilizer was beneficial to dry matter accumulation of S. miltiorrhiza aerial parts, and low concentration of nitrogen fertilizer transferred the dry matter accumulation to underground, and N1P1 could make the transfer ahead of time;②Regression analysis showed that in the early growth stage (before early July), we could use the nitrogen and phosphorus as basic fertilizer at a concentration of 1.521,0.355 g•L⁻¹ respectively to promote the growth of S. miltiorrhiza and at a concentration of 2.281,0.710 g•L⁻¹ respectively to promote the dry matter accumulation of root (after mid-August);③Five kinds of active components of S. miltiorrhiza decreased with the increase of nitrogen concentration, and increased with the increase of the concentration of phosphate fertilizer. Nitrogenous fertilizer, phosphate fertilizer in N-P=2∶3 ratio was more suitable for the accumulation of salvianolic acids, in N-P=1∶2 ratio was more suitable for the accumulation of tanshinone. Copyright© by the Chinese Pharmaceutical Association.

Effect of the surface heterogeneity of the stationary phase on the range of concentration for linear chromatography

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

Gritti, Fabrice; Guiochon, Georges A

2005-02-01

The range of sample sizes within which linear chromatographic behavior is achieved in a column depends on the surface heterogeneity of the RPLC adsorbents. Two widely different commercial adsorbents were tested, the end-capped XTerra-C{sub 18} and the non-end-capped Resolve-C{sub 18}. Adsorption isotherm data of caffeine were acquired by frontal analysis. These data were modeled and used to calculate the adsorption energy distribution (AED). This double analysis informs on the degree of surface heterogeneity. The best adsorption isotherm models are the bi-Langmuir and the tetra-Langmuir isotherms for XTerra and Resolve, respectively. Their respective AEDs are bimodal and quadrimodal distributions. This interpretationmore » of the results and the actual presence of a low density of high-energy adsorption sites on Resolve-C{sub 18} were validated by measuring the dependence of the peak retention times on the size of caffeine samples (20-{micro}L volume, concentrations 10, 1, 0.1, 1 x 10{sup -2}, 1 x 10{sup -3}, 1 x 10{sup -4}, and 1 x 10{sup -5} g/L). The experimental chromatograms agree closely with the band profiles calculated from the best isotherms. On Resolve-C{sub 18}, the retention time decreases by 40% when the sample concentration is increased from 1 x 10{sup -5} to 10 g/L. The decrease is only 10% for Xterra-C{sub 18} under the same conditions. The upper limit for linear behavior is 1 x 10{sup -4} g/L for the former adsorbent and 0.01 g/L for the latter. The presence of a few high-energy adsorption sites on Resolve-C{sub 18}, with an adsorption energy 20 kJ/mol larger than that of the low-energy sites while the same difference on Xterra is only 5 kJ/mol, explains this difference. The existence of adsorption sites with a very high energy for certain compounds affects the reproducibility of their retention times and a rapid loss of efficiency in a sample size range within which linear behavior is incorrectly anticipated.« less

Electrolytes for Low Impedance, Wide Operating Temperature Range Lithium-Ion Battery Module

NASA Technical Reports Server (NTRS)

Hallac, Boutros (Inventor); Krause, Frederick C. (Inventor); Jiang, Junwei (Inventor); Smart, Marshall C. (Inventor); Metz, Bernhard M. (Inventor); Bugga, Ratnakumar V. (Inventor)

2018-01-01

A lithium ion battery cell includes a housing, a cathode disposed within the housing, wherein the cathode comprises a cathode active material, an anode disposed within the housing, wherein the anode comprises an anode active material, and an electrolyte disposed within the housing and in contact with the cathode and anode. The electrolyte consists essentially of a solvent mixture, a lithium salt in a concentration ranging from approximately 1.0 molar (M) to approximately 1.6 M, and an additive mixture. The solvent mixture includes a cyclic carbonate, an non-cyclic carbonate, and a linear ester. The additive mixture consists essentially of lithium difluoro(oxalato)borate (LiDFOB) in an amount ranging from approximately 0.5 weight percent to approximately 2.0 weight percent based on the weight of the electrolyte, and vinylene carbonate (VC) in an amount ranging from approximately 0.5 weight percent to approximately 2.0 weight percent based on the weight of the electrolyte.

Air Data - Concentration Map

EPA Pesticide Factsheets

Make a map of daily concentrations over several days. The daily air quality can be displayed in terms of the Air Quality Index or in concentration ranges for certain PM species like organic carbon, nitrates, and sulfates.

Sol concentration effect on ZnO nanofibers photocatalytic activity synthesized by sol-gel dip coating method

NASA Astrophysics Data System (ADS)

Toubane, M.; Tala-Ighil, R.; Bensouici, F.; Bououdina, M.; Souier, M.; Liu, S.; Cai, W.; Iratni, A.

2017-03-01

ZnO thin films were deposited onto glass substrate by sol-gel dip coating method. The initial sol concentrations were varied from 0.2 to 0.5 M. Zinc acetate dihydrate, ethanol and Diethanolamine (DEA) were used as staring material, solvent and stabilizer respectively. The evolution of structural, optical properties and methylene blue (MB) photodegradation of the as-deposited films on sol concentration was investigated. Rietveld refinements of x-ray patterns reveal that all the as-prepared thin films have a Zincite-type structure with grain orientation along to c-axis. The strongest sol concentration is favorable for the highest crystallization quality. However, the high preferred orientation factor (POF) occurs for 0.3 M sol concentration. The field emission scanning electron microscopy observations reveals nanofibrous morphology with different lengths. The nanofibers density increases with increasing sols concentrations until forming a flower-like morphology. The EDS analysis confirms the high purity of the as-deposited ZnO films. It is found that all films present good transparency greater than 95% in the visible range; the optical band gap is slightly reduced with the increase in sol concentration. The photocatalytic degradation is enhanced by 90% with the sol concentration. The K app rate reaction increased with increasing sol concentration. The films stability is found to slightly decrease after the third cycle, especially for 0.5 M sol concentration.

Range degradation and distal edge behavior of proton radiotherapy beams using 11C activation and Monte Carlo simulation

NASA Astrophysics Data System (ADS)

Elmekawy, Ahmed Farouk

The distal edge of therapeutic proton radiation beams was investigated by different methods. Proton beams produced at the Hampton University Proton Therapy Institute (HUPTI) were used to irradiate a Polymethylmethacrylate (PMMA) phantom for three different ranges (13.5, 17.0 and 21.0 cm) to investigate the distal slope dependence of the Bragg peak. The activation of 11 C was studied by scanning the phantom less than 10 minutes post-irradiation with a Philips Big Bore Gemini(c) PET/CT. The DICOM images were imported into the Varian Eclipse(c) Treatment Planning System (TPS) for analysis and then analyzed by ImageJ(c) . The distal slope ranged from ?0.1671 +/- 0.0036 to -0.1986 +/- 0.0052 (pixel intensity/slice number) for ranges 13.5 to 21.0 cm respectively. A realistic description of the setup was modeled using the GATE 7.0 Monte Carlo simulation tool and compared to the experiment data. The results show the distal slope ranged from -0.1158+/-0.0133 to -0.0787+/-0.002 (Gy/mm). Additionally, low activity, 11C were simulated to study the 11C reconstructed half-life dependence versus the initial activity for six ranges chosen around the previous activation study. The results of the expected/nominal half-life vs. activity ranged from -5 x 10-4 +/- 2.8104 x 10-4 to 1.6 x 10-3 +/- 9.44 x 10-4 (%diff./Bq). The comparison between two experiments with proton beams on a PMMA phantom and multi-layer ion chamber, and two GATE simulations of a proton beam incident on a water phantom and 11C PET study show that: (i) the distal fall-off variation of the steepness of the slopes are found to be similar thus validating the sensitivity of the PET technique to the range degradation and (ii) the average of the super-ratios difference between all studies observed is primarily due to the difference in the dose deposited in the media.

Impact of limited solvent capacity on metabolic rate, enzyme activities, and metabolite concentrations of S. cerevisiae glycolysis.

PubMed

Vazquez, Alexei; de Menezes, Marcio A; Barabási, Albert-László; Oltvai, Zoltan N

2008-10-01

The cell's cytoplasm is crowded by its various molecular components, resulting in a limited solvent capacity for the allocation of new proteins, thus constraining various cellular processes such as metabolism. Here we study the impact of the limited solvent capacity constraint on the metabolic rate, enzyme activities, and metabolite concentrations using a computational model of Saccharomyces cerevisiae glycolysis as a case study. We show that given the limited solvent capacity constraint, the optimal enzyme activities and the metabolite concentrations necessary to achieve a maximum rate of glycolysis are in agreement with their experimentally measured values. Furthermore, the predicted maximum glycolytic rate determined by the solvent capacity constraint is close to that measured in vivo. These results indicate that the limited solvent capacity is a relevant constraint acting on S. cerevisiae at physiological growth conditions, and that a full kinetic model together with the limited solvent capacity constraint can be used to predict both metabolite concentrations and enzyme activities in vivo.

Impact of Limited Solvent Capacity on Metabolic Rate, Enzyme Activities, and Metabolite Concentrations of S. cerevisiae Glycolysis

PubMed Central

Vazquez, Alexei; de Menezes, Marcio A.; Barabási, Albert-László; Oltvai, Zoltan N.

2008-01-01

The cell's cytoplasm is crowded by its various molecular components, resulting in a limited solvent capacity for the allocation of new proteins, thus constraining various cellular processes such as metabolism. Here we study the impact of the limited solvent capacity constraint on the metabolic rate, enzyme activities, and metabolite concentrations using a computational model of Saccharomyces cerevisiae glycolysis as a case study. We show that given the limited solvent capacity constraint, the optimal enzyme activities and the metabolite concentrations necessary to achieve a maximum rate of glycolysis are in agreement with their experimentally measured values. Furthermore, the predicted maximum glycolytic rate determined by the solvent capacity constraint is close to that measured in vivo. These results indicate that the limited solvent capacity is a relevant constraint acting on S. cerevisiae at physiological growth conditions, and that a full kinetic model together with the limited solvent capacity constraint can be used to predict both metabolite concentrations and enzyme activities in vivo. PMID:18846199

Effect of nano-zinc oxide on nitrogenase activity in legumes: an interplay of concentration and exposure time

NASA Astrophysics Data System (ADS)

Kumar, Praveen; Burman, Uday; Santra, P.

2015-07-01

Experiments were carried out to study the effect of zinc oxide nanoparticles (nano-ZnO) on nitrogenase activity in legumes. In the first experiment, nodulated roots of cluster bean, moth bean, green gram and cowpea were dipped in Hoagland solution containing 1.5 and 10 μg mL-1 of nano-ZnO for 24 h. Nitrogenase activity in cluster bean, green gram and cowpea roots increased after dipping in solution containing 1.5 μg mL-1 nano-ZnO, but decreased in roots dipped in solution containing 10 μg mL-1 nano-ZnO. However, in moth bean roots, nitrogenase activity decreased after dipping in solution containing either concentration of nano-ZnO. In the second experiment, nodulated roots of green gram were dipped in Hoagland solution containing 1, 4, 6, 8 and 10 μg mL-1 nano-ZnO for 6-30 h before estimating nitrogenase activity. Results showed that an interactive effect of nano-ZnO concentration and exposure time influenced nitrogenase activity. The possible reasons behind this effect have been discussed. A model [ A = 3.44 + 0.46 t - 0.01 t 2 - 0.002 tc 2 ( R 2 = 0.81)] involving linear and power components was developed to simulate the response of nitrogenase activity in green gram roots to the concentration and exposure time of nano-ZnO.

A Theoretical Basis for the Transition to Denitrification at Nanomolar Oxygen Concentrations

NASA Astrophysics Data System (ADS)

Zakem, E.; Follows, M. J.

2016-02-01

Current climate change is likely to expand the size and intensity of marine oxygen minimum zones. How will this affect denitrification rates? Current global biogeochemical models typically prescribe a critical oxygen concentration below which anaerobic activity occurs, rather than resolve the underlying microbial processes. Here, we explore the dynamics of an idealized, simulated anoxic zone in which multiple prokaryotic metabolisms are resolved mechanistically, defined by redox chemistry and biophysical constraints. We first ask, what controls the critical oxygen concentration governing the favorability of aerobic or anaerobic respiration? The predicted threshold oxygen concentration varies as a function of the environment as well as of cell physiology, and lies within the nanomolar range. The model thus provides a theoretical underpinning for the recent observations of nanomolar oxygen concentrations in oxygen minimum zones. In the context of an idealized, two-dimensional intensified upwelling simulation, we also predict denitrification at oxygen concentrations orders of magnitude higher due to physical mixing, reconciling observations of denitrification over a similar range and demonstrating a decoupling of denitrification from the local oxygen concentration. In a sensitivity study with the idealized ocean model, we comment upon the relationship between the volume of anoxic waters and total denitrification.

Waste activated sludge fermentation: effect of solids retention time and biomass concentration.

PubMed

Yuan, Q; Sparling, R; Oleszkiewicz, J A

2009-12-01

Laboratory scale, room temperature, semi-continuous reactors were set-up to investigate the effect of solids retention time (SRT, equal to HRT hydraulic retention time) and biomass concentration on generation of volatile fatty acids (VFA) from the non-methanogenic fermentation of waste activated sludge (WAS) originating from an enhanced biological phosphorus removal process. It was found that VFA yields increased with SRT. At the longest SRT (10d), improved biomass degradation resulted in the highest soluble to total COD ratio and the highest VFA yield from the influent COD (0.14g VFA-COD/g TCOD). It was also observed that under the same SRT, VFA yields increased when the biomass concentration decreased. At a 10d SRT the VFA yield increased by 46%, when the biomass concentration decreased from 13g/L to 4.8g/L. Relatively high nutrient release was observed during fermentation. The average phosphorus release was 17.3mg PO(4)-P/g TCOD and nitrogen release was 25.8mg NH(4)-N/g TCOD.

Adaptation of cytochrome-b5 reductase activity and methaemoglobinaemia in areas with a high nitrate concentration in drinking-water.

PubMed Central

Gupta, S. K.; Gupta, R. C.; Seth, A. K.; Gupta, A. B.; Bassin, J. K.; Gupta, A.

1999-01-01

An epidemiological investigation was undertaken in India to assess the prevalence of methaemoglobinaemia in areas with high nitrate concentration in drinking-water and the possible association with an adaptation of cytochrome-b5 reductase. Five areas were selected, with average nitrate ion concentrations in drinking-water of 26, 45, 95, 222 and 459 mg/l. These areas were visited and house schedules were prepared in accordance with a statistically designed protocol. A sample of 10% of the total population was selected in each of the areas, matched for age and weight, giving a total of 178 persons in five age groups. For each subject, a detailed history was documented, a medical examination was conducted and blood samples were taken to determine methaemoglobin level and cytochrome-b5 reductase activity. Collected data were subjected to statistical analysis to test for a possible relationship between nitrate concentration, cytochrome-b5 reductase activity and methaemoglobinaemia. High nitrate concentrations caused methaemoglobinaemia in infants and adults. The reserve of cytochrome-b5 reductase activity (i.e. the enzyme activity not currently being used, but which is available when needed; for example, under conditions of increased nitrate ingestion) and its adaptation with increasing water nitrate concentration to reduce methaemoglobin were more pronounced in children and adolescents. PMID:10534899

Determination of tungsten and molybdenum concentrations from an x-ray range spectrum in JET with the ITER-like wall configuration

NASA Astrophysics Data System (ADS)

Nakano, T.; Shumack, A. E.; Maggi, C. F.; Reinke, M.; Lawson, K. D.; Coffey, I.; Pütterich, T.; Brezinsek, S.; Lipschultz, B.; Matthews, G. F.; Chernyshova, M.; Jakubowska, K.; Scholz, M.; Rzadkiewicz, J.; Czarski, T.; Dominik, W.; Kasprowicz, G.; Pozniak, K.; Zabolotny, W.; Zastrow, K.-D.; Conway, N. J.; contributors, JET

2015-07-01

The {{W}45+} and {{W}46+} 3p-4d inner shell excitation lines in addition to M{{o}32+} 2p-3s lines have been identified from the spectrum taken by an upgraded high-resolution x-ray spectrometer. It is found from analysis of the absolute intensities of the {{W}46+} and M{{o}32+} lines that W and Mo concentrations are in the range of ˜ {{10}-5} and ˜ {{10}-6}, respectively, with a ratio of ˜5% in JET with the ITER-like wall configuration for ELMy H-mode plasmas with a plasma current of 2.0-2.5 MA, a toroidal magnetic field of 2.7 T and a neutral beam injection power of 14-18 MW. For the purpose of checking self-consistency, it is confirmed that the W concentration determined from the {{W}45+} line is in agreement with that from the {{W}46+} line within 20% and that the plasma effective charge determined from the continuum of the first order reflection spectrum is also in agreement with that from the second order within 50%. Further, the determined plasma effective charge is in agreement with that determined from a visible spectroscopy, confirming that the sensitivity of the x-ray spectrometer is valid and that the W and the Mo concentrations are also likely to be valid.

Blood concentrations of clobazam and norclobazam in a lethal case involving clobazam, meprobamate and clorazepate.

PubMed

Pok, Phak-Rop Pos; Mauras, Michel; De Saint Léger, Marie-Noëlle; Kuhlmann, Erika; Charpenel-Durat, Catherine; Navarette, Claudie; Duval, Marie-Laure; De Meo, Pierre

2010-11-01

Clobazam is a benzodiazepine with anti-anxiety and anticonvulsant properties marketed in several countries. Norclobazam, a metabolite of clobazam, has similar pharmacological activity but weaker sedative and tranquilizing effect. The two drugs were detected by GC-MS and determined by HPLC-DAD in the samples from a postmortem case. The femoral blood concentrations of clobazam and norclobazam were 0.72 and 36 μg/mL, respectively. The concentration of the active norclobazam was very high. The sum of both clobazam and norclobazam blood concentration (36.72 μg/mL) was clearly toxic, but was not necessarily fatal. Other associated drugs concentrations were within their therapeutic ranges. Interactions due to drug association were discussed. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

Metformin and phenformin activate AMP-activated protein kinase in the heart by increasing cytosolic AMP concentration.

PubMed

Zhang, Li; He, Huamei; Balschi, James A

2007-07-01

AMP-activated protein kinase (AMPK) acts as a cellular energy sensor: it responds to an increase in AMP concentration ([AMP]) or the AMP-to-ATP ratio (AMP/ATP). Metformin and phenformin, which are biguanides, have been reported to increase AMPK activity without increasing AMP/ATP. This study tests the hypothesis that these biguanides increase AMPK activity in the heart by increasing cytosolic [AMP]. Groups of isolated rat hearts (n = 5-7 each) were perfused with Krebs-Henseleit buffer with or without 0.2 mM phenformin or 10 mM metformin, and (31)P-NMR-measured phosphocreatine, ATP, and intracellular pH were used to calculate cytosolic [AMP]. At various times, hearts were freeze-clamped and assayed for AMPK activity, phosphorylation of Thr(172) on AMPK-alpha, and phosphorylation of Ser(79) on acetyl-CoA carboxylase, an AMPK target. In hearts treated with phenformin for 18 min and then perfused for 20 min with Krebs-Henseleit buffer, [AMP] began to increase at 26 min and AMPK activity was elevated at 36 min. In hearts treated with metformin, [AMP] was increased at 50 min and AMPK activity, phosphorylated AMPK, and phosphorylated acetyl-CoA carboxylase were elevated at 61 min. In metformin-treated hearts, HPLC-measured total AMP content and total AMP/ATP did not increase. In summary, phenformin and metformin increase AMPK activity and phosphorylation in the isolated heart. The increase in AMPK activity was always preceded by and correlated with increased cytosolic [AMP]. Total AMP content and total AMP/ATP did not change. Cytosolic [AMP] reported metabolically active AMP, which triggered increased AMPK activity, but measures of total AMP did not.

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

Effect of Fe doping concentration on photocatalytic activity of ZnO nanosheets under natural sunlight

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

Khokhra, Richa; Kumar, Rajesh, E-mail: rajesh.kumar@juit.ac.in

2015-05-15

A facile room temperature, aqueous solution-based chemical method has been adopted for large-scale synthesis of Fe doped ZnO nanosheets. The XRD and SEM results reveal the as-synthesized products well crystalline and accumulated by large amount of interweave nanosheets, respectively. Energy dispersive spectroscopy data confirmed Fe doping of the ZnO nanosheets with a varying Fe concentration. The photoluminescence spectrum reveals a continuous suppression of defect related emissions intensity by increasing the concentration of the Fe ion. A photocatalytic activity using these samples under sunlight irradiation in the mineralization of methylene blue dye was investigated. The photocatalytic activity of Fe doped ZnOmore » nanosheets depends upon the presence of surface oxygen vacancies.« less

Serum concentration comparisons of amino acids, fatty acids, lipoproteins, vitamins A and E, and minerals between zoo and free-ranging giraffes (Giraffa camelopardalis).

PubMed

Schmidt, Debra A; Koutsos, Elizabeth A; Ellersieck, Mark R; Griffin, Mark E

2009-03-01

Serum concentrations of amino acids, fatty acids, lipoproteins, vitamins A and E, and minerals in zoo giraffes (Giraffa camelopardalis) were compared to values obtained from free-ranging giraffes in an effort to identify potential nutritional differences in the zoo population. Zoo giraffes have a specific set of maladies that may be nutritionally related, including peracute mortality, energy malnutrition, pancreatic disease, urolithiasis, hoof disease, and severe intestinal parasitism. Dietary requirements for giraffes are not known; invasive studies used with domestic animals cannot be performed on zoo animals. Though domestic animal standards are often used to evaluate nutritional health of exotic animals, they may not be the most appropriate standards to use. Serum samples from 20 zoo giraffes at 10 zoological institutions in the United States were compared to previously collected samples from 24 free-ranging giraffes in South Africa. Thirteen of the zoo animal samples were collected from animals trained for blood collection, and seven were banked samples obtained from a previous serum collection. Dietary information was also collected on each zoo giraffe; most zoo giraffe diets consisted of alfalfa-based pellets (acid detergent fiber-16), alfalfa hay, and browse in varying quantities. Differences between zoo and free-ranging giraffes, males and females, and adults and subadults were analyzed with the use of a 2 x 2 x 2 factorial and Fisher's Least Significant Difference (LSD) for mean separation. Of the 84 parameters measured, 54 (60%) were significantly different (P < or = 0.05) between zoo and free-ranging giraffes. Nine (11%) items were significantly different (P < or = 0.05) between adult and subadult animals. Only one parameter, sodium concentration, was found to be significantly different (P < or = 0.05) between genders. Further investigation in zoo giraffe diets is needed to address the differences seen in this study and the potentially related health

Effects of environmental conditions, human activity, reproduction, antler cycle and grouping on fecal glucocorticoids of free-ranging Pampas deer stags (Ozotoceros bezoarticus bezoarticus).

PubMed

Garcia Pereira, Ricardo José; Barbanti Duarte, José Maurício; Negrão, João Alberto

2006-01-01

In this study, a commercial enzyme immunoassay (EIA) was validated in detecting glucocorticoids in Pampas deer feces, in order to investigate the influence of several factors on the adrenocortical function. Fecal samples, behavioral data and information concerning male grouping and antlers status were collected at a monthly basis during a 1 year period from free-ranging stags living at Emas National Park, Brazil (18 degrees S/52 degrees W). The results revealed that concentrations of fecal glucocorticoids in winter were significantly higher than those corresponding to spring and summer. In addition, dry season data presented higher levels than during the wet season. Significant difference was found between fecal levels of breeding stags in summer and nonbreeding stags, whereas no difference was observed between breeding stags in winter and nonbreeding stags. On the other hand, males from areas with frequent human disturbance exhibited higher glucocorticoid concentrations and flight distances than individuals from areas of lower human activity. Males with antlers in velvet had elevated levels compared with animals in hard antler or antler casting. Also, we found that glucocorticoid levels were higher in groups with three or more males than in groups with only one male. The flight distances showed positive correlation with fecal glucocorticoid. These data indicate that fecal glucocorticoid provides a useful approach in the evaluation of physiological effects of environment, inter-individuals relationship and human-induced stressors on free-ranging Pampas deer stags.

Genotoxicity and antileishmanial activity evaluation of Physalis angulata concentrated ethanolic extract.

PubMed

Nogueira, Renata Campos; Rocha, Vinicius Pinto Costa; Nonato, Fabiana Regina; Tomassini, Therezinha Coelho Barbosa; Ribeiro, Ivone Maria; dos Santos, Ricardo Ribeiro; Soares, Milena Botelho Pereira

2013-11-01

Antileishmanial in vitro tests, as well as Ames and micronucleus assays were performed with a concentrated ethanolic extract of Physalis angulata (EEPA) RESULTS: EEPA did not present mutagenic effect in Salmonella typhimurium strains at concentration reaching 3000 μg/plate and did not induce mutagenic effects after two oral administrations with a 24h interval at a dose level of 2000 mg/kg. EEPA presented antileishmanial activity and presented an IC₅₀ value of 5.35 ± 2.50 μg/mL and 4.50 ± 1.17 μg/mL against Leishmania amazonensis and Leishmania braziliensis promastigotes, respectively. In the cytotoxicity test against macrophages, the EEPA had a LC₅₀ of 6.14 ± 0.59 μg/mL. Importantly, the IC₅₀ against L. amazonensis intracellular amastigotes was 1.23 ± 0.11 μg/mL. EEPA extract is non-mutagenic and presented a promising pharmacological effect against Leishmania parasites. Copyright © 2013 Elsevier B.V. All rights reserved.

CMOS Active Pixel Sensors as energy-range detectors for proton Computed Tomography.

PubMed

Esposito, M; Anaxagoras, T; Evans, P M; Green, S; Manolopoulos, S; Nieto-Camero, J; Parker, D J; Poludniowski, G; Price, T; Waltham, C; Allinson, N M

2015-06-03

Since the first proof of concept in the early 70s, a number of technologies has been proposed to perform proton CT (pCT), as a means of mapping tissue stopping power for accurate treatment planning in proton therapy. Previous prototypes of energy-range detectors for pCT have been mainly based on the use of scintillator-based calorimeters, to measure proton residual energy after passing through the patient. However, such an approach is limited by the need for only a single proton passing through the energy-range detector in a read-out cycle. A novel approach to this problem could be the use of pixelated detectors, where the independent read-out of each pixel allows to measure simultaneously the residual energy of a number of protons in the same read-out cycle, facilitating a faster and more efficient pCT scan. This paper investigates the suitability of CMOS Active Pixel Sensors (APSs) to track individual protons as they go through a number of CMOS layers, forming an energy-range telescope. Measurements performed at the iThemba Laboratories will be presented and analysed in terms of correlation, to confirm capability of proton tracking for CMOS APSs.

Soil processes and tree growth at shooting ranges in a boreal forest reflect contamination history and lead-induced changes in soil food webs.

PubMed

Selonen, Salla; Setälä, Heikki

2015-06-15

The effects of shooting-derived lead (Pb) on the structure and functioning of a forest ecosystem, and the recovery of the ecosystem after range abandonment were studied at an active shotgun shooting range, an abandoned shooting range where shooting ceased 20 years earlier and an uncontaminated control site. Despite numerous lead-induced changes in the soil food web, soil processes were only weakly related to soil food web composition. However, decomposition of Scots pine (Pinus sylvestris) needle litter was retarded at the active shooting range, and microbial activity, microbial biomass and the rate of decomposition of Pb-contaminated grass litter decreased with increasing soil Pb concentrations. Tree (P. sylvestris) radial growth was suppressed at the active shooting range right after shooting activities started. In contrast, the growth of pines improved at the abandoned shooting range after the cessation of shooting, despite reduced nitrogen and phosphorus contents of the needles. Higher litter degradation rates and lower Pb concentrations in the topmost soil layer at the abandoned shooting range suggest gradual recovery after range abandonment. Our findings suggest that functions in lead-contaminated coniferous forest ecosystems depend on the successional stage of the forest as well as the time since the contamination source has been eliminated, which affects, e.g., the vertical distribution of the contaminant in the soil. However, despite multiple lead-induced changes throughout the ecosystem, the effects were rather weak, indicating high resistance of coniferous forest ecosystems to this type of stress. Copyright © 2015 Elsevier B.V. All rights reserved.

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

NASA Astrophysics Data System (ADS)

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

2017-11-01

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

Active laser ranging with frequency transfer using frequency comb

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

Zhang, Hongyuan; Wei, Haoyun; Yang, Honglei

2016-05-02

A comb-based active laser ranging scheme is proposed for enhanced distance resolution and a common time standard for the entire system. Three frequency combs with different repetition rates are used as light sources at the two ends where the distance is measured. Pulse positions are determined through asynchronous optical sampling and type II second harmonic generation. Results show that the system achieves a maximum residual of 379.6 nm and a standard deviation of 92.9 nm with 2000 averages over 23.6 m. Moreover, as for the frequency transfer, an atom clock and an adjustable signal generator, synchronized to the atom clock, are used asmore » time standards for the two ends to appraise the frequency deviation introduced by the proposed system. The system achieves a residual fractional deviation of 1.3 × 10{sup −16} for 1 s, allowing precise frequency transfer between the two clocks at the two ends.« less

Rectified directional sensing in long-range cell migration

PubMed Central

Nakajima, Akihiko; Ishihara, Shuji; Imoto, Daisuke; Sawai, Satoshi

2014-01-01

How spatial and temporal information are integrated to determine the direction of cell migration remains poorly understood. Here, by precise microfluidics emulation of dynamic chemoattractant waves, we demonstrate that, in Dictyostelium, directional movement as well as activation of small guanosine triphosphatase Ras at the leading edge is suppressed when the chemoattractant concentration is decreasing over time. This ‘rectification’ of directional sensing occurs only at an intermediate range of wave speed and does not require phosphoinositide-3-kinase or F-actin. From modelling analysis, we show that rectification arises naturally in a single-layered incoherent feedforward circuit with zero-order ultrasensitivity. The required stimulus time-window predicts ~5 s transient for directional sensing response close to Ras activation and inhibitor diffusion typical for protein in the cytosol. We suggest that the ability of Dictyostelium cells to move only in the wavefront is closely associated with rectification of adaptive response combined with local activation and global inhibition. PMID:25373620

Nitrous Oxide Emissions in a Managed Grassland are Strongly Influenced by CO2 Concentrations Across a Range of Soil Moisture Levels

NASA Astrophysics Data System (ADS)

Brown, Z. A.; Hovenden, M. J.; Hunt, M.

2017-12-01

Though the atmosphere contains less nitrous oxide (N2O, 324 ppb) than carbon dioxide (CO2, 400 ppm­), N2O has 298 times the global warming potential of CO2 on a 100-year horizon. Nitrous oxide emissions tend to be greater in moist soils because denitrification is an anaerobic process. The rising concentration of CO2 in the atmosphere reduces plant stomatal aperture, thereby slowing transpiration and water use and leading to higher soil moisture levels. Thus, the rising CO2 concentration could stimulate N2O emissions indirectly via increasing soil moisture. Further, results from field experiments in which CO2 is elevated have demonstrated nitrification is accelerated at elevated CO2 concentrations (eCO2). Hence, N2O emissions could be substantially increased by the impacts of rising CO2 concentrations on plant and ecosystem physiology. However, the scale of this impact could be influenced by the amount of water supplied through irrigation or rainfall since both nitrification and denitrification are sensitive to soil moisture. Here, we use measurements of CO2 and N2O emissions from the TasFACE2 experiment to explore the ways in which the impact of CO2 concentration on greenhouse gas emissions is influenced by water supply in a managed temperate pasture. TasFACE2 is the world's only experiment that explicitly controls soil water availability at three different CO2 concentrations. Application of chemical nitrification inhibitor severely reduces N2O flux from soils regardless of CO2 level, water treatment and time following urea application. This inhibitor reduced soil respiration in plots exposed to ambient CO2 plots but not in eCO2 plots. N2O flux is stimulated by eCO2 but not consistently among watering treatments or seasons. Soil respiration is strongly enhanced by CO2 effect regardless of watering treatment. The results demonstrate that CO2 concentration has a sustained impact on CO2 and N2O flux across a range of water availabilities in this fertilised, ryegrass

Anti-Toxoplasma activity of various molecular weights and concentrations of chitosan nanoparticles on tachyzoites of RH strain.

PubMed

Teimouri, Aref; Azami, Sanaz Jafarpour; Keshavarz, Hossein; Esmaeili, Fariba; Alimi, Rasoul; Mavi, Sara Ayazian; Shojaee, Saeedeh

2018-01-01

Natural polysaccharides such as chitosan (CS) are widely used as antimicrobial agents. In recent years, and considering that CS has a strong antimicrobial potential, interest has been focused on antimicrobial activity of chitosan nanoparticles (CS NPs). The main factors affecting the antibacterial activity of chitosan include molecular weight (MW) and concentration. In this regard, the aim of this study was to produce various MWs and concentrations of CS NPs, through the ionic gelation method, and investigate their potential anti-parasitic activity against tachyzoites of Toxoplasma gondii RH strain. The MWs and degree of deacetylation of the CS were characterized using viscometric and acid-base titration methods, respectively. The efficacy of various MWs and concentrations of NPs was assessed by performing in vitro experiments for tachyzoites of T. gondii RH strain, such as MTT assay, scanning electron microscopy, bioassay in mice and PCR. In vivo experiment was carried out in BALB/c mice which were inoculated with tachyzoites of T. gondii RH strain and treated with various MWs of CS NPs. The results of in vitro and in vivo experiments revealed that anti- Toxoplasma activity strengthened as the CS NPs concentration increased and the MW decreased. In vitro experiment showed 100% mortality of tachyzoites at 500 and 1,000 ppm concentrations of low molecular weight (LMW) CS NPs after 180 min and at 2,000 ppm after 120 min. Furthermore, a 100% mortality of tachyzoites was observed at 1,000 and 2,000 ppm concentrations of medium molecular weight (MMW) CS NPs and at 2,000 ppm concentration of high molecular weight (HMW) CS NPs after 180 min. Growth inhibition rates of tachyzoites in peritoneal exudates of mice receiving low, medium and high MWs of CS NPs were found to be 86%, 84% and 79% respectively, compared to those of mice in sulfadiazine treatment group (positive control). Various MWs of CS NPs exhibited great anti- Toxoplasma efficiency against tachyzoites of RH

Hemostatic variables, plasma lactate concentration, and inflammatory biomarkers in dogs with gastric dilatation-volvulus.

PubMed

Verschoof, J; Moritz, A; Kramer, M; Bauer, N

2015-01-01

Prospective characterization of hemostastatic variables, plasma lactate concentration, and inflammatory biomarkers in dogs with gastric dilatation-volvulus (GDV). Coagulation variables (platelets, prothrombin time [PT], activated partial thromboplastin time [aPTT], fibrinogen, antithrombin [AT], protein C [PC], protein S [PS], D-dimers), plasma lactate concentration and inflammatory biomarkers (C-reactive protein, white blood cell [WBC] count, lymphocyte and neutrophil numbers) were assessed in 20 dogs with GDV presented between 2011 and 2012. Blood was taken preoperatively and at days 1 and 3 postoperatively. The prognostic value of these variables before and after surgery was evaluated as well as the behavior of variables during the study. Overall, 7/20 (35%) dogs did not survive; two dogs (29%) were euthanized during surgery due to severe gastric necrosis and 5 (71%) dogs after surgery due to sepsis and disseminated intravascular coagulopathy. Prior to surgery, median plasma lactate concentration was significantly (p = 0.01) lower in survivors (6.2 mmol/l, range 1.9-9.7 mmol/l) when compared to non-survivors (11.8 mmol/l, range 7.5-16.2 mmol/l). In dogs dying after surgery, significantly higher plasma lactate concentration, coagulation times and D-dimer concentration were present as well as lower fibrinogen concentration and activity of PC and AT compared to survivors. At discharge, activity of AT, PC and PS were markedly below the reference interval in 6/13 (46%), 11/13 (85%), and 8/13 (62%) dogs, respectively. Only lactate plasma concentration was of preoperative prognostic value. After surgery, severe abnormalities of coagulation variables, especially the endogenous anticoagulants were present in most of the dogs. The severity of the abnormalities was associated with survival.

Re-activation of the peptidyltransferase centre of rabbit reticulocyte ribosomes after inactivation by exposure to low concentrations of magnesium ion.

PubMed Central

Cox, R A; Greenwell, P; Hirst, W

1976-01-01

1. The larger subrivosomal particles of rabbit reticulocytes retained full activity in the puromycin reaction and in poly(U)-directed polyphenylalanine synthesis after 4h at 0 degrees C when buffered 0.5M-NH4Cl/10-30mM-MgCl2 was the solvent. 2. Activity in the puromycin reaction was diminished to approx 10% after 15-30 min at 0 degrees C when the concentration of MgCl2 was lowered to 2mM. 3. Activity was not restored when the concentration of MgCl2 was raised from 2mM to 10-30 mM at 0 degrees C. However, activity was recovered as measured by both assay systems when the ribosome fraction was heated to 37 degrees C at the higher concentrations of MgCl2. 4. Recovery of activity was noted during the course of the polyphenylalanine synthesis in 50 mM-KCl/5mM-MgCl2/25mM-Tris/HCl, pH 7.6, at 37 degrees C. Re-activation was slow at 20 degrees C and below. 5. No more than about 5% of the protein moiety of the subparticle was lost in 0.5M-NH4Cl on decreasing MgCl2 concentration from 10mM to 2mM. No proteins were detected in the supernatant fractions by gel electrophoresis after ribosomes were separated by differential centrifugation. The supernatant fraction was not essential for the recovery of activity. However, at higher (e.g. 1M) concentrations of NH4Cl, proteins were split from the subparticle. 6. The loss and regain of activity found on lowering and restoring the concentration of MgCl2 at 0.5M-NH4Cl appears to arise from a conformational change that does not seem to be associated with a loss and regain of particular proteins. 7. A 2% decrease in E260 was noticed when the concentration of Mg2+ was restored, and the change in the spectrum indicated a net increase of approx. 100A-U base-pairs per subribosomal particle. 8. When the concentration of Mg2+ was restored, S20,W of the subparticle remained at 52+/- 1S until the sample was incubated at 37 degrees C when S20,W increased to 56 +/- 1S compared with the value of 58 +/- 1S for the subparticle as originally isolated

Estimated Glomerular Filtration Rate Is a Poor Predictor of Concentration for a Broad Range of Uremic Toxins

PubMed Central

Schepers, Eva; Barreto, Daniela V.; Barreto, Fellype C.; Liabeuf, Sophie; Van Biesen, Wim; Verbeke, Francis; Glorieux, Griet; Choukroun, Gabriel; Massy, Ziad; Vanholder, Raymond

2011-01-01

Summary Background and objectives The degree of chronic kidney disease (CKD) is currently expressed in terms of GFR, which can be determined directly or estimated according to different formulas on the basis of serum creatinine and/or cystatin C measurements (estimated GFR [eGFR]). The purpose of this study was to investigate whether eGFR values are representative for uremic toxin concentrations in patients with different degrees of CKD. Design, setting, participants, & measurements Associations between eGFR based on serum cystatin C and different uremic solutes (mol wt range 113 to 240 D; determined by colorimetry, HPLC, or ELISA) were evaluated in 95 CKD patients not on dialysis (CKD stage 2 to 5). The same analysis was also applied for six other eGFR formulas. Results There was a substantial disparity in fits among solutes. In linear regression, explained variance of eGFR was extremely low for most solutes, with eGFR > 0.4 only for creatinine. The other eGFR formulations gave comparably disappointing results with regard to their association to uremic solutes. Relative similarity in R2 values per solute for the different eGFR values and the strong disparity in values between solutes suggest that the differences in R2 are mainly due to discrepancies in solute handling apart from GFR. Conclusions eGFR is poorly associated with concentrations of all studied uremic toxins in patients with different degrees of CKD, correlates differently with each individual solute, and can thus not be considered representative for evaluating the accumulation of solutes in the course of CKD. PMID:21617084

Short-range density functional correlation within the restricted active space CI method

NASA Astrophysics Data System (ADS)

Casanova, David

2018-03-01

In the present work, I introduce a hybrid wave function-density functional theory electronic structure method based on the range separation of the electron-electron Coulomb operator in order to recover dynamic electron correlations missed in the restricted active space configuration interaction (RASCI) methodology. The working equations and the computational algorithm for the implementation of the new approach, i.e., RAS-srDFT, are presented, and the method is tested in the calculation of excitation energies of organic molecules. The good performance of the RASCI wave function in combination with different short-range exchange-correlation functionals in the computation of relative energies represents a quantitative improvement with respect to the RASCI results and paves the path for the development of RAS-srDFT as a promising scheme in the computation of the ground and excited states where nondynamic and dynamic electron correlations are important.

IL-1β-induced and p38MAPK-dependent activation of the mitogen-activated protein kinase-activated protein kinase 2 (MK2) in hepatocytes: Signal transduction with robust and concentration-independent signal amplification

PubMed Central

Kulawik, Andreas; Engesser, Raphael; Ehlting, Christian; Raue, Andreas; Albrecht, Ute; Hahn, Bettina; Lehmann, Wolf-Dieter; Gaestel, Matthias; Klingmüller, Ursula; Häussinger, Dieter; Timmer, Jens; Bode, Johannes G.

2017-01-01

The IL-1β induced activation of the p38MAPK/MAPK-activated protein kinase 2 (MK2) pathway in hepatocytes is important for control of the acute phase response and regulation of liver regeneration. Many aspects of the regulatory relevance of this pathway have been investigated in immune cells in the context of inflammation. However, very little is known about concentration-dependent activation kinetics and signal propagation in hepatocytes and the role of MK2. We established a mathematical model for IL-1β-induced activation of the p38MAPK/MK2 pathway in hepatocytes that was calibrated to quantitative data on time- and IL-1β concentration-dependent phosphorylation of p38MAPK and MK2 in primary mouse hepatocytes. This analysis showed that, in hepatocytes, signal transduction from IL-1β via p38MAPK to MK2 is characterized by strong signal amplification. Quantification of p38MAPK and MK2 revealed that, in hepatocytes, at maximum, 11.3% of p38MAPK molecules and 36.5% of MK2 molecules are activated in response to IL-1β. The mathematical model was experimentally validated by employing phosphatase inhibitors and the p38MAPK inhibitor SB203580. Model simulations predicted an IC50 of 1–1.2 μm for SB203580 in hepatocytes. In silico analyses and experimental validation demonstrated that the kinase activity of p38MAPK determines signal amplitude, whereas phosphatase activity affects both signal amplitude and duration. p38MAPK and MK2 concentrations and responsiveness toward IL-1β were quantitatively compared between hepatocytes and macrophages. In macrophages, the absolute p38MAPK and MK2 concentration was significantly higher. Finally, in line with experimental observations, the mathematical model predicted a significantly higher half-maximal effective concentration for IL-1β-induced pathway activation in macrophages compared with hepatocytes, underscoring the importance of cell type-specific differences in pathway regulation. PMID:28223354

Global earthquake catalogs and long-range correlation of seismic activity (Invited)

NASA Astrophysics Data System (ADS)

Ogata, Y.

2009-12-01

In view of the long-term seismic activity in the world, homogeneity of a global catalog is indispensable. Lately, Engdahl and Villaseñor (2002) compiled a global earthquake catalog of magnitude (M)7.0 or larger during the last century (1900-1999). This catalog is based on the various existing catalogs such as Abe catalog (Abe, 1981, 1984; Abe and Noguchi, 1983a, b) for the world seismicity (1894-1980), its modified catalogs by Perez and Scholz (1984) and by Pacheco and Sykes (1992), and also the Harvard University catalog since 1975. However, the original surface wave magnitudes of Abe catalog were systematically changed by Perez and Scholz (1984) and Pacheco and Sykes (1992). They suspected inhomogeneity of the Abe catalog and claimed that the two seeming changes in the occurrence rate around 1922 and 1948 resulted from magnitude shifts for some instrumental-related reasons. They used a statistical test assuming that such a series of large earthquakes in the world should behave as the stationary Poisson process (uniform occurrences). It is obvious that their claim strongly depends on their a priori assumption of an independent or short-range dependence of earthquake occurrence. We question this assumption from the viewpoint of long-range dependence of seismicity. We make some statistical analyses of the spectrum, dispersion-time diagrams and R/S for estimating and testing of the long-range correlations. We also attempt to show the possibility that the apparent rate change in the global seismicity can be simulated by a certain long-range correlated process. Further, if we divide the globe into the two regions of high and low latitudes, for example, we have different shapes of the cumulative curves to each other, and the above mentioned apparent change-points disappear from the both regions. This suggests that the Abe catalog shows the genuine seismic activity rather than the artifact of the suspected magnitude shifts that should appear in any wide enough regions

The effect of concentration- and temperature-dependent dielectric constant on the activity coefficient of NaCl electrolyte solutions

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

Valiskó, Mónika; Boda, Dezső, E-mail: boda@almos.vein.hu

2014-06-21

Our implicit-solvent model for the estimation of the excess chemical potential (or, equivalently, the activity coefficient) of electrolytes is based on using a dielectric constant that depends on the thermodynamic state, namely, the temperature and concentration of the electrolyte, ε(c, T). As a consequence, the excess chemical potential is split into two terms corresponding to ion-ion (II) and ion-water (IW) interactions. The II term is obtained from computer simulation using the Primitive Model of electrolytes, while the IW term is estimated from the Born treatment. In our previous work [J. Vincze, M. Valiskó, and D. Boda, “The nonmonotonic concentration dependencemore » of the mean activity coefficient of electrolytes is a result of a balance between solvation and ion-ion correlations,” J. Chem. Phys. 133, 154507 (2010)], we showed that the nonmonotonic concentration dependence of the activity coefficient can be reproduced qualitatively with this II+IW model without using any adjustable parameter. The Pauling radii were used in the calculation of the II term, while experimental solvation free energies were used in the calculation of the IW term. In this work, we analyze the effect of the parameters (dielectric constant, ionic radii, solvation free energy) on the concentration and temperature dependence of the mean activity coefficient of NaCl. We conclude that the II+IW model can explain the experimental behavior using a concentration-dependent dielectric constant and that we do not need the artificial concept of “solvated ionic radius” assumed by earlier studies.« less

Impacts of visitor number on Kangaroos housed in free-range exhibits.

PubMed

Sherwen, Sally L; Hemsworth, Paul H; Butler, Kym L; Fanson, Kerry V; Magrath, Michael J L

2015-01-01

Free range exhibits are becoming increasingly popular in zoos as a means to enhance interaction between visitors and animals. However very little research exists on the impacts of visitors on animal behaviour and stress in free range exhibits. We investigated the effects of visitor number on the behaviour and stress physiology of Kangaroo Island (KI) Kangaroos, Macropus fuliginosus fuliginosus, and Red Kangaroos, Macropus rufus, housed in two free range exhibits in Australian zoos. Behavioural observations were conducted on individual kangaroos at each site using instantaneous scan sampling to record activity (e.g., vigilance, foraging, resting) and distance from the visitor pathway. Individually identifiable faecal samples were collected at the end of each study day and analysed for faecal glucocorticoid metabolite (FGM) concentration. When visitor number increased, both KI Kangaroos and Red Kangaroos increased the time spent engaged in visitor-directed vigilance and KI Kangaroos also increased the time spent engaged in locomotion and decreased the time spent resting. There was no effect of visitor number on the distance kangaroos positioned themselves from the visitor pathway or FGM concentration in either species. While there are limitations in interpreting these results in terms of fear of visitors, there was no evidence of adverse effects animal welfare in these study groups based on avoidance behaviour or stress physiology under the range of visitor numbers that we studied. © 2015 Wiley Periodicals, Inc.

Effect of Salinity and Alkalinity on Luciobarbus capito Gill Na+/K+-ATPase Enzyme Activity, Plasma Ion Concentration, and Osmotic Pressure

PubMed Central

2016-01-01

We evaluated the individual and combined effects of salinity and alkalinity on gill Na+/K+-ATPase enzyme activity, plasma ion concentration, and osmotic pressure in Luciobarbus capito. Increasing salinity concentrations (5, 8, 11, and 14 g/L) were associated with an initial increase and then decrease in L. capito gill Na+/K+-ATPase activity. Activity was affected by the difference between internal and external Na+ ion concentrations and osmotic pressure (P < 0.05). Both plasma ion (Na+, K+, and Cl−) concentration and osmotic pressure increased significantly (P < 0.05). An increase in alkalinity (15, 30, 45, and 60 mM) caused a significant increase in plasma K+ and urea nitrogen concentrations (P < 0.05) but had no effect on either plasma osmotic pressure or gill filament ATPase activity. In the two-factor experiment, the saline-alkaline interaction caused a significant increase in plasma ion (Na+, Cl−, and urea nitrogen) and osmotic pressure (P < 0.05). Variance analysis revealed that salinity, alkalinity, and their interaction significantly affected osmotic pressure, with salinity being most affected, followed by alkalinity, and their interaction. Gill filament ATPase activity increased at first and then decreased; peak values were observed in the orthogonal experiment group at a salinity of 8 g/L and alkalinity of 30 mM. PMID:27981049

Horizontally staggered lightguide solar concentrator with lateral displacement tracking for high concentration applications.

PubMed

Ma, Hongcai; Wu, Lin

2015-07-10

We present the design of a horizontally staggered lightguide solar concentrator with lateral displacement tracking for high concentration applications. This solar concentrator consists of an array of telecentric primary concentrators, a horizontally staggered lightguide layer, and a vertically tapered lightguide layer. The primary concentrator is realized by two plano-aspheric lenses with lateral movement and maintains a high F-number over an angle range of ±23.5°. The results of the simulations show that the solar concentrator achieves a high concentration ratio of 500× with ±0.5° of acceptance angle by a single-axis tracker and dual lateral translation stages.