Mechanisms and kinetic profiles of superoxide-stimulated nitrosative processes in cells using a diaminofluorescein probe

AbstractIn this study, we examined the mechanisms and kinetic profiles of intracellular nitrosative processes using diaminofluorescein (DAF-2) as a target in RAW 264.7 cells. The intracellular formation of the fluorescent, nitrosated product diaminofluorescein triazol (DAFT) from both endogenous and exogenous nitric oxide (NO) was prevented by deoxygenation and by cell membrane-permeable superoxide (O2−) scavengers but not by extracellular bovine Cu,Zn-SOD. In addition, the DAFT formation rate decreased in the presence of cell membrane-permeable Mn porphyrins that are known to scavenge peroxynitrite (ONOO−) but was enhanced by HCO3−/CO2. Together, these results indicate that nitrosative processes in RAW 264.7 cells depend on endogenous intracellular O2− and are stimulated by ONOO−/CO2-derived radical oxidants. The N2O3 scavenger sodium azide (NaN3) only partially attenuated the DAFT formation rate and only with high NO (>120nM), suggesting that DAFT formation occurs by nitrosation (azide-susceptible DAFT formation) and predominantly by oxidative nitrosylation (azide-resistant DAFT formation). Interestingly, the DAFT formation rate increased linearly with NO concentrations of up to 120–140nM but thereafter underwent a sharp transition and became insensitive to NO. This behavior indicates the sudden exhaustion of an endogenous cell substrate that reacts rapidly with NO and induces nitrosative processes, consistent with the involvement of intracellular O2−. On the other hand, intracellular DAFT formation stimulated by a fixed flux of xanthine oxidase-derived extracellular O2− that also occurs by nitrosation and oxidative nitrosylation increased, peaked, and then decreased with increasing NO, as previously observed. Thus, our findings complementarily show that intra- and extracellular O2−-dependent nitrosative processes occurring by the same chemical mechanisms do not necessarily depend on NO concentration and exhibit different unusual kinetic profiles with NO dynamics, depending on the biological compartment in which NO and O2− interact

Synthesis of calculational methods for the design and analysis of radiation shields for nuclear rocket systems. Volume 8 - DAFT, ODD-K angular flux tapes program Final progress report

ODD-K angular flux tape computer program for radiation shielding design and analysis in nuclear rocket system

An examination of the effects of self-regulatory focus on the perception of the media richness: the case of email

Communication is a key element in organizations’ business success. The media richness theory and the channel expansion theory are two of the most influential theories regarding the selection and use of communication media in organizations; however, literature has focused little on the effects of self-regulation by managers and employees in these theories. To analyze these topics, this study develops an empirical investigation by gathering data from 600 managers and employees using a questionnaire. The results suggest that the perception of media richness is positively affected when the individual shows a promotion focus or strategy.Peer ReviewedPostprint (author’s final draft

THE POLITICAL/ECONOMIC ENVIRONMENT: ARE WE AT A WATERSHED?

Political Economy,

U.S. COMPETITIVENESS AND NEEDED ADJUSTMENTS

Agricultural and Food Policy,

TOWARD A POSSIBLY PRACTICAL FRAMEWORK FOR RURAL DEVELOPMENT POLICIES AND PROGRAMS

Community/Rural/Urban Development,

Investigation of Ammonia and Nitrate Removal From Municipal Wastewater Using Biowish

This research entails investigation of ammonia, nitrate, and nitrite removal from wastewater using a proprietary blend of bacteria known as BiOWiSHTM. The degradation rates of ammonia, nitrate, and nitrite for Aqua were determined using wastewater at the San Luis Obispo Water Resource Recovery Facility (SLO WRRF). Laboratory and field experiments were conducted to test how Aqua compared with natural bacteria for removal of nitrogen compounds. Preliminary data suggested that Aqua performed nitrate removal best in SLO WRRF wastewater at the secondary clarifier. Aqua could perform anoxic and aerobic denitrification in secondary clarifier wastewater. In mineral media, Aqua removed 6.6 mg NO3-N/L/hr. In partially sterilized wastewater, Aqua removed 2.67 mg NO3-N/L/hr. Field experiments using a batch reactor suggested that Aqua aided in nitrate removal when dosed above 25 ppm in secondary clarifier wastewater. A dose of 25 ppm Aqua resulted in a 0.1 mg NO3-N/L/hr removal rate. A dose of 50 ppm Aqua resulted in a 0.15 mg NO3-N/L/hr. Aqua did not aid in ammonia or nitrate removal in sludgewash at the SLO WRRF likely due to high concentrations of nitrate and ammonia existing in the wastewater were toxic to Aqua. Aqua removed about 5 ppm more nitrate than a competitor bacteria blend in a laboratory setting. Activating Aqua to increase initial cell count before inoculation did not have any effect on removal. Providing partial aeration did not help nitrification rates and inhibited nitrate removal for Aqua. Laboratory experiments showed that Aqua did not remove nitrate in final clarifier wastewater most likely due to a limited carbon source. Aqua can perform nitrification in mineral media. Aerobic activation of Aqua inhibited denitrification. Aqua activated anoxically can perform denitrification. Using a powder with 70% microbial cultures, instead of the 1% found in Aqua, resulted in quicker nitrate removal. Inoculating as a concentrated liquid versus a dry powder did not affect nitrate removal rates. Use of trace mineral media did not affect nitrate removal rates

Influence of Movement Quality on Heart Rate While Performing the Dance-Specific Aerobic Fitness Test (DAFT) in Preprofessional Contemporary Dancers.

To explore whether movement quality has influence on heart rate (HR) frequency during the dance-specific aerobic fitness test (DAFT). Thirteen contemporary university dance students (age 19 ± 1.46 yrs) underwent two trials performing the DAFT while wearing a Polar HR monitor (Kempele, Finland). During the first trial, dancers were asked to perform the movements as if they were performing on stage, whereas during the second trial, standardized verbal instructions were given to reduce the quality of movement (e.g., no need to perform technically correct pliés). The variables measured at each trial were HR for all five stages of the DAFT and HR recovery (1 and 2 min after finishing the DAFT), movement quality (MQ) score, and rate of perceived exertion score (RPE). There were significant differences in HR between Trial 1 and Trial 2. For all stages and the resting period, HR was lower during Trial 2 (p<0.001). Also, the RPE score was significantly lower and the MQ score was significantly higher, indicating a poorer performance, during Trial 2 (both p<0.001). The results suggest that DAFT performance with lower movement quality elicits lower HR frequency and RPE during the DAFT. We recommend that specific instructions be given to participants about executing the movement sequence during the DAFT before testing commences. Also, movement quality must be taken into account when interpreting HR results from the DAFT in order to distinguish if a dancer's low HR results from good aerobic fitness or from poor performance of the movement sequence

The DAFT/FADA survey. I.Photometric redshifts along lines of sight to clusters in the z=[0.4,0.9] interval

As a contribution to the understanding of the dark energy concept, the Dark energy American French Team (DAFT, in French FADA) has started a large project to characterize statistically high redshift galaxy clusters, infer cosmological constraints from Weak Lensing Tomography, and understand biases relevant for constraining dark energy and cluster physics in future cluster and cosmological experiments. The purpose of this paper is to establish the basis of reference for the photo-z determination used in all our subsequent papers, including weak lensing tomography studies. This project is based on a sample of 91 high redshift (z>0.4), massive clusters with existing HST imaging, for which we are presently performing complementary multi-wavelength imaging. This allows us in particular to estimate spectral types and determine accurate photometric redshifts for galaxies along the lines of sight to the first ten clusters for which all the required data are available down to a limit of I_AB=24/24.5 with the LePhare software. The accuracy in redshift is of the order of 0.05 for the range 0.2<z<1.5. We verified that the technique applied to obtain photometric redshifts works well by comparing our results to with previous works. In clusters, photoz accuracy is degraded for bright absolute magnitudes and for the latest and earliest type galaxies. The photoz accuracy also only slightly varies as a function of the spectral type for field galaxies. As a consequence, we find evidence for an environmental dependence of the photoz accuracy, interpreted as the standard used Spectral Energy Distributions being not very well suited to cluster galaxies. Finally, we modeled the LCDCS 0504 mass with the strong arcs detected along this line of sight.Comment: Accepted in A&