Portable tester for determining gas content within a core sample

DOEpatents

Garcia, F. Jr.; Schatzel, S.J.

1998-04-21

A portable tester is provided for reading and displaying the pressure of a gas released from a rock core sample stored within a sealed container and for taking a sample of the released pressurized gas for chemical analysis thereof for subsequent use in a modified direct method test which determines the volume of gas and specific type of gas contained within the core sample. The portable tester includes a pair of low and high range electrical pressure transducers for detecting a gas pressure; a pair of low and high range display units for displaying the pressure of the detected gas; a selector valve connected to the low and high range pressure transducers and a selector knob for selecting gas flow to one of the flow paths; control valve having an inlet connection to the sealed container; and outlets connected to: a sample gas canister, a second outlet port connected to the selector valve means for reading the pressure of the gas from the sealed container to either the low range or high range pressure transducers, and a connection for venting gas contained within the sealed container to the atmosphere. A battery is electrically connected to and supplies the power for operating the unit. The pressure transducers, display units, selector and control valve means and the battery is mounted to and housed within a protective casing for portable transport and use. 5 figs.

Color deviation controlling of phosphor conformal coating by advanced spray painting technology for white LEDs.

PubMed

Yang, Liang; Wang, Simin; Lv, Zhicheng; Liu, Sheng

2013-04-01

An advanced phosphor conformal coating technology is proposed, good correlated color temperature (CCT) and chromaticity uniformity samples are fabricated through phosphor spray painting technology. Spray painting technology is also suitable for phosphor conformal coating of whole LED wafers. The samples of different CCTs are obtained through controlling the phosphor film thickness in the range of 6-80 μm; CCT variation of samples can be controlled in the range of ±200 K. The experimental Δuv reveals that the spray painting method can obtain a much smaller CCT variation (Δuv of 1.36e(-3)) than the conventional dispensing method (Δuv of 11.86e(-3)) when the light is emitted at angles from -90° to +90°, and chromaticity area uniformity is also improved significantly.

Combined effect of an oxygen absorber and oregano essential oil on shelf life extension of rainbow trout fillets stored at 4 degrees C.

PubMed

Mexis, S F; Chouliara, E; Kontominas, M G

2009-09-01

In the present study the combined effect of an O2 absorber and oregano essential oil (0.4% v/w) on shelf life extension of rainbow trout fillets (Onchorynchus mykiss) stored under refrigeration (4 degrees C) was investigated. The study was based on microbiological [TVC, Pseudomonas spp., Lactic Acid Bacteria, H2S-producing bacteria including Shewanella putrefaciens, Enterobacteriaceae and Clostridium spp.), physicochemical (pH, PV, TBA, TVBN and Drip loss) and sensory (odor, taste) changes occurring in the product as a function of treatment and storage time. Aerobically-packaged rainbow trout fillets stored at 4 degrees C were taken as control samples. Results showed that TVC exceeded 7 log cfu/g on day 4 of storage for control samples, day 7-8 for samples containing oregano oil, day 9 for samples containing the O2 absorber and day 12-13 for samples containing the O2 absorber and oregano oil. Pseudomonas spp., Enterobacteriaceae and LAB were only partially inhibited by the O2 absorber and/or the oregano oil. In all cases the inhibition effect was more pronounced when the combination of O2 absorber with oregano essential oil was used. pH decreased from an initial value of 6.65-6.09 and subsequently increased to 6.86 due to formation of protein decomposition products. % Drip loss ranged between 7% and 11-12% at the end of the product shelf life. PV values ranged between 11.4 and 27.0 meq O2/kg oil while malondialdehyde (MDA) ranged between 9.6 and 24.5 mg/kg. TVBN ranged between 10.6 and 54.6 mg/kg at the time of sensory rejection. Sensory shelf life was 4 days for the control samples, 7-8 days for samples containing oregano oil, 13-14 days for samples containing the O2 absorber and 17 days for samples containing the O2 absorber plus oregano oil.

Crowdsourcing for large-scale mosquito (Diptera: Culicidae) sampling

USDA-ARS?s Scientific Manuscript database

Sampling a cosmopolitan mosquito (Diptera: Culicidae) species throughout its range is logistically challenging and extremely resource intensive. Mosquito control programmes and regional networks operate at the local level and often conduct sampling activities across much of North America. A method f...

Detection of human enteric viruses in stream water with RT-PCR and cell culture.

USGS Publications Warehouse

Denis-Mize, K.; Fout, G.S.; Dahling, D.R.; Francy, D.S.

2004-01-01

A multiplex RT-PCR method was used to measure virus occurrence at five stream water sites that span a range of hydroclimatic, water-quality, and land-use characteristics. The performance of the molecular method was evaluated in comparison with traditional cell culture and Escherichia coli membrane filtration assays. The study incorporated multiple quality controls and included a control for virus recovery during the sampling procedure as well as controls to detect potentially false-negative and false-positive data. Poliovirus recovery ranged from 16 to 65% and was variable, even in samples collected within the same stream. All five sites were positive for viruses by both molecular and cell culture-based virus assays. Enteroviruses, reoviruses, rotaviruses, and hepatitis A viruses were detected, but the use of the quality controls proved critical for interpretation of the molecular data. All sites showed evidence of faecal contamination, and culturable viruses were detected in four samples that would have met the US Environmental Protection Agency's recommended E. coli guideline for safe recreational water.

Characterizing concentrations of diethylene glycol and suspected metabolites in human serum, urine, and cerebrospinal fluid samples from the Panama DEG mass poisoning.

PubMed

Schier, J G; Hunt, D R; Perala, A; McMartin, K E; Bartels, M J; Lewis, L S; McGeehin, M A; Flanders, W D

2013-12-01

Diethylene glycol (DEG) mass poisoning is a persistent public health problem. Unfortunately, there are no human biological data on DEG and its suspected metabolites in poisoning. If present and associated with poisoning, the evidence for use of traditional therapies such as fomepizole and/or hemodialysis would be much stronger. To characterize DEG and its metabolites in stored serum, urine, and cerebrospinal fluid (CSF) specimens obtained from human DEG poisoning victims enrolled in a 2006 case-control study. In the 2006 study, biological samples from persons enrolled in a case-control study (42 cases with new-onset, unexplained AKI and 140 age-, sex-, and admission date-matched controls without AKI) were collected and shipped to the Centers for Disease Control and Prevention (CDC) in Atlanta for various analyses and were then frozen in storage. For this study, when sufficient volume of the original specimen remained, the following analytes were quantitatively measured in serum, urine, and CSF: DEG, 2-hydroxyethoxyacetic acid (HEAA), diglycolic acid, ethylene glycol, glycolic acid, and oxalic acid. Analytes were measured using low resolution GC/MS, descriptive statistics calculated and case results compared with controls when appropriate. Specimens were de-identified so previously collected demographic, exposure, and health data were not available. The Wilcoxon Rank Sum test (with exact p-values) and bivariable exact logistic regression were used in SAS v9.2 for data analysis. The following samples were analyzed: serum, 20 case, and 20 controls; urine, 11 case and 22 controls; and CSF, 11 samples from 10 cases and no controls. Diglycolic acid was detected in all case serum samples (median, 40.7 mcg/mL; range, 22.6-75.2) and no controls, and in all case urine samples (median, 28.7 mcg/mL; range, 14-118.4) and only five (23%) controls (median, < Lower Limit of Quantitation (LLQ); range, < LLQ-43.3 mcg/mL). Significant differences and associations were identified between case status and the following: 1) serum oxalic acid and serum HEAA (both OR = 14.6; 95% C I = 2.8-100.9); 2) serum diglycolic acid and urine diglycolic acid (both OR > 999; exact p < 0.0001); and 3) urinary glycolic acid (OR = 0.057; 95% C I = 0.001-0.55). Two CSF sample results were excluded and two from the same case were averaged, yielding eight samples from eight cases. Diglycolic acid was detected in seven (88%) of case CSF samples (median, 2.03 mcg/mL; range, < LLQ, 7.47). Significantly elevated HEAA (serum) and diglycolic acid (serum and urine) concentrations were identified among cases, which is consistent with animal data. Low urinary glycolic acid concentrations in cases may have been due to concurrent AKI. Although serum glycolic concentrations among cases may have initially increased, further metabolism to oxalic acid may have occurred thereby explaining the similar glycolic acid concentrations in cases and controls. The increased serum oxalic acid concentration results in cases versus controls are consistent with this hypothesis. Diglycolic acid is associated with human DEG poisoning and may be a biomarker for poisoning. These findings add to animal data suggesting a possible role for traditional antidotal therapies. The detection of HEAA and diglycolic acid in the CSF of cases suggests a possible association with signs and symptoms of DEG-associated neurotoxicity. Further work characterizing the pathophysiology of DEG-associated neurotoxicity and the role of traditional toxic alcohol therapies such as fomepizole and hemodialysis is needed.

Flow cytometric analyses of CD34+ cells with inclusion of internal positive controls.

PubMed

Gutensohn, Kai; Jessen, Maria; Ketels, Andrea; Gramatzki, Martin; Humpe, Andreas

2012-02-01

Flow cytometric measurement of CD34+ events is used to ensure the quality of human progenitor cell grafts. This study was conducted to evaluate whether the spiking of routine samples from peripheral blood and apheresis products with CD34+ positive controls is feasible. A total of 42 samples from 32 patients and one healthy donor were stained in duplicate for CD34+ cells. Before flow cytometric analysis, one tube was spiked with stabilized CD34+ cells at a defined concentration. Median numbers of viable CD34+ cells/µL did not differ between unspiked and spiked tubes (median 37, range 0-714; and median 34, range 0-719, respectively). The 95% confidence interval (CI) of the mean showed a broad overlap between these samples (41.9-119.1 and 41.4-119.3, respectively). In addition, the 95% CI of the mean for CD45+ cells/µL overlapped broadly and median numbers did not differ. Median viability of all CD45+ cells was significantly lower in the spiked tubes (96.75, range 64-98.8 vs. 99.25, range 97.5-99.8) with no overlap of the 95% CI of the mean viability. The results of this study show that spiking of routine samples with internal positive controls does not affect CD34+ cell analyses, but does support the reliability of important clinical data. The inclusion of positive controls is expedient for laboratories that perform analyses with low CD34+ numbers and laboratories that use different flow cytometric analyzers and may also become a requirement to meet statutory regulations. © 2012 American Association of Blood Banks.

Dissolved pesticides, dissolved organic carbon, and water-quality characteristics in selected Idaho streams, April--December 2010

USGS Publications Warehouse

Reilly, Timothy J.; Smalling, Kelly L.; Wilson, Emma R.; Battaglin, William A.

2012-01-01

Water-quality samples were collected from April through December 2010 from four streams in Idaho and analyzed for a suite of pesticides, including fungicides, by the U.S. Geological Survey. Water samples were collected from two agricultural and two nonagricultural (control) streams approximately biweekly from the beginning of the growing season (April) through the end of the calendar year (December). Samples were analyzed for 90 pesticides using gas chromatography/mass spectrometry. Twenty-three pesticides, including 8 fungicides, 10 herbicides, 3 insecticides, and 2 pesticide degradates, were detected in 45 water samples. The most frequently detected compounds in the two agricultural streams and their detection frequencies were metolachlor, 96 percent; azoxystrobin, 79 percent; boscalid, 79 percent; atrazine, 46 percent; pendimethalin, 33 percent; and trifluralin, 33 percent. Dissolved-pesticide concentrations ranged from below instrumental limits of detection (0.5-1.0 nanograms per liter) to 771 nanograms per liter (hexazinone). The total number of pesticides detected in any given water sample ranged from 0 to 11. Only three pesticides (atrazine, fipronil, and simazine) were detected in samples from the control streams during the sampling period.

Plasma current collection of Z-93 thermal control paint as measured in the Lewis Research Center's plasma interaction facility

NASA Technical Reports Server (NTRS)

Hillard, G. Barry

1993-01-01

A sample of Z-93 thermal control paint was exposed to a simulated space environment in a plasma chamber. The sample was biased through a series of voltages ranging from -100 volts to +300 volts and electron and ion currents were measured. Currents were found to be in the micro-ampere range indicating that the material remains a reasonably good insulator under plasma conditions. As a second step, the sample was left in the chamber for six days and retested. Collected currents were reduced by from two to five times from the previous values indicating a substantial loss of conductivity. As a final test, the sample was removed, exposed to room conditions for two days, and returned to the chamber. Current measurements showed that the sample had partially recovered the lost conductivity. In addition to presenting these results, this report documents all of the experimental data as well as the statistical analyses performed.

Robotic solid phase extraction and high performance liquid chromatographic analysis of ranitidine in serum or plasma.

PubMed

Lloyd, T L; Perschy, T B; Gooding, A E; Tomlinson, J J

1992-01-01

A fully automated assay for the analysis of ranitidine in serum and plasma, with and without an internal standard, was validated. It utilizes robotic solid phase extraction with on-line high performance liquid chromatographic (HPLC) analysis. The ruggedness of the assay was demonstrated over a three-year period. A Zymark Py Technology II robotic system was used for serial processing from initial aspiration of samples from original collection containers, to final direct injection onto the on-line HPLC system. Automated serial processing with on-line analysis provided uniform sample history and increased productivity by freeing the chemist to analyse data and perform other tasks. The solid phase extraction efficiency was 94% throughout the assay range of 10-250 ng/mL. The coefficients of variation for within- and between-day quality control samples ranged from 1 to 6% and 1 to 5%, respectively. Mean accuracy for between-day standards and quality control results ranged from 97 to 102% of the respective theoretical concentrations.

CFO compensation method using optical feedback path for coherent optical OFDM system

NASA Astrophysics Data System (ADS)

Moon, Sang-Rok; Hwang, In-Ki; Kang, Hun-Sik; Chang, Sun Hyok; Lee, Seung-Woo; Lee, Joon Ki

2017-07-01

We investigate feasibility of carrier frequency offset (CFO) compensation method using optical feedback path for coherent optical orthogonal frequency division multiplexing (CO-OFDM) system. Recently proposed CFO compensation algorithms provide wide CFO estimation range in electrical domain. However, their practical compensation range is limited by sampling rate of an analog-to-digital converter (ADC). This limitation has not drawn attention, since the ADC sampling rate was high enough comparing to the data bandwidth and CFO in the wireless OFDM system. For CO-OFDM, the limitation is becoming visible because of increased data bandwidth, laser instability (i.e. large CFO) and insufficient ADC sampling rate owing to high cost. To solve the problem and extend practical CFO compensation range, we propose a CFO compensation method having optical feedback path. By adding simple wavelength control for local oscillator, the practical CFO compensation range can be extended to the sampling frequency range. The feasibility of the proposed method is experimentally investigated.

Recovery and Enumeration of Cryptosporidium parvum from Animal Fecal Matrices

PubMed Central

Davies, Cheryl M.; Kaucner, Christine; Deere, Daniel; Ashbolt, Nicholas J.

2003-01-01

Accurate quantification of Cryptosporidium parvum oocysts in animal fecal deposits on land is an essential starting point for estimating watershed C. parvum loads. Due to the general poor performance and variable recovery efficiency of existing enumeration methods, protocols were devised based on initial dispersion of oocysts from feces by vortexing in 2 mM tetrasodium pyrophosphate, followed by immunomagnetic separation. The protocols were validated by using an internal control seed preparation to determine the levels of oocyst recovery for a range of fecal types. The levels of recovery of 102 oocysts from cattle feces (0.5 g of processed feces) ranged from 31 to 46%, and the levels of recovery from sheep feces (0.25 g of processed feces) ranged from 21% to 35%. The within-sample coefficients of variation for the percentages of recovery from five replicates ranged from 10 to 50%. The ranges for levels of recovery of oocysts from cattle, kangaroo, pig, and sheep feces (juveniles and adults) collected in a subsequent watershed animal fecal survey were far wider than the ranges predicted by the validation data. Based on the use of an internal control added to each fecal sample, the levels of recovery ranged from 0 to 83% for cattle, from 4 to 62% for sheep, from 1 to 42% for pigs, and from 40 to 73% for kangaroos. Given the variation in the levels of recovery of oocysts from different fecal matrices, it is recommended that an internal control be added to at least one replicate of every fecal sample analyzed to determine the percentage of recovery. Depending on the animal type and based on the lowest approximate percentages of recovery, between 10 and 100 oocysts g of feces−1 must be present to be detected. PMID:12732556

Comparison of anticipated and actual control group outcomes in randomised trials in paediatric oncology provides evidence that historically controlled studies are biased in favour of the novel treatment.

PubMed

Moroz, Veronica; Wilson, Jayne S; Kearns, Pamela; Wheatley, Keith

2014-12-10

Historically controlled studies are commonly undertaken in paediatric oncology, despite their potential biases. Our aim was to compare the outcome of the control group in randomised controlled trials (RCTs) in paediatric oncology with those anticipated in the sample size calculations in the protocols. Our rationale was that, had these RCTs been performed as historical control studies instead, the available outcome data used to calculate the sample size in the RCT would have been used as the historical control outcome data. A systematic search was undertaken for published paediatric oncology RCTs using the Cochrane Central Register of Controlled Trials (CENTRAL) database from its inception up to July 2013. Data on sample size assumptions and observed outcomes (timetoevent and proportions) were extracted to calculate differences between randomised and historical control outcomes, and a one-sample t-test was employed to assess whether the difference between anticipated and observed control groups differed from zero. Forty-eight randomised questions were included. The median year of publication was 2005, and the range was from 1976 to 2010. There were 31 superiority and 11 equivalence/noninferiority randomised questions with time-to-event outcomes. The median absolute difference between observed and anticipated control outcomes was 5.0% (range: -23 to +34), and the mean difference was 3.8% (95% CI: +0.57 to +7.0; P = 0.022). Because the observed control group (that is, standard treatment arm) in RCTs performed better than anticipated, we found that historically controlled studies that used similar assumptions for the standard treatment were likely to overestimate the benefit of new treatments, potentially leading to children with cancer being given ineffective therapy that may have additional toxicity.

General purpose rocket furnace

NASA Technical Reports Server (NTRS)

Aldrich, B. R.; Whitt, W. D. (Inventor)

1979-01-01

A multipurpose furnace for space vehicles used for material processing experiments in an outer space environment is described. The furnace contains three separate cavities designed to process samples of the widest possible range of materials and thermal requirements. Each cavity contains three heating elements capable of independent function under the direction of an automatic and programmable control system. A heat removable mechanism is also provided for each cavity which operates in conjunction with the control system for establishing an isothermally heated cavity or a wide range of thermal gradients and cool down rates. A monitoring system compatible with the rocket telemetry provides furnace performance and sample growth rate data throughout the processing cycle.

Prevalence of Campylobacter and Salmonella species on farm, after transport, and at processing in specialty market poultry.

PubMed

McCrea, B A; Tonooka, K H; VanWorth, C; Boggs, C L; Atwill, E R; Schrader, J S

2006-01-01

The prevalence of Campylobacter and Salmonella spp. was determined from live bird to prepackaged carcass for 3 flocks from each of 6 types of California niche-market poultry. Commodities sampled included squab, quail, guinea fowl, duck, poussin (young chicken), and free-range broiler chickens. Campylobacter on-farm prevalence was lowest for squab, followed by guinea fowl, duck, quail, and free-range chickens. Poussin had the highest prevalence of Campylobacter. No Salmonella was isolated from guinea fowl or quail flocks. A few positive samples were observed in duck and squab, predominately of S. Typhimurium. Free-range and poussin chickens had the highest prevalence of Salmonella. Post-transport prevalence was not significantly higher than on-farm, except in free-range flocks, where a higher prevalence of positive chickens was found after 6 to 8 h holding before processing. In most cases, the prevalence of Campylobacter- and Salmonella-positive birds was lower on the final product than on-farm or during processing. Odds ratio analysis indicated that the risk of a positive final product carcass was not increased by the prevalence of a positive sample at an upstream point in the processing line, or by on-farm prevalence (i.e., none of the common sampling stations among the 6 commodities could be acknowledged as critical control points). This suggests that hazard analysis critical control point plans for Campylobacter and Salmonella control in the niche-market poultry commodities will need to be specifically determined for each species and each processing facility.

Modified midi- and mini-multiplex PCR systems for mitochondrial DNA control region sequence analysis in degraded samples.

PubMed

Kim, Na Young; Lee, Hwan Young; Park, Sun Joo; Yang, Woo Ick; Shin, Kyoung-Jin

2013-05-01

Two multiplex polymerase chain reaction (PCR) systems (Midiplex and Miniplex) were developed for the amplification of the mitochondrial DNA (mtDNA) control region, and the efficiencies of the multiplexes for amplifying degraded DNA were validated using old skeletal remains. The Midiplex system consisted of two multiplex PCRs to amplify six overlapping amplicons ranging in length from 227 to 267 bp. The Miniplex system consisted of three multiplex PCRs to amplify 10 overlapping short amplicons ranging in length from 142 to 185 bp. Most mtDNA control region sequences of several 60-year-old and 400-500-year-old skeletal remains were successfully obtained using both PCR systems and consistent with those previously obtained by monoplex amplification. The multiplex system consisting of smaller amplicons is effective for mtDNA sequence analyses of ancient and forensic degraded samples, saving time, cost, and the amount of DNA sample consumed during analysis. © 2013 American Academy of Forensic Sciences.

Buoyancy-corrected gravimetric analysis of lightly loaded filters.

PubMed

Rasmussen, Pat E; Gardner, H David; Niu, Jianjun

2010-09-01

Numerous sources of uncertainty are associated with the gravimetric analysis of lightly loaded air filter samples (< 100 microg). The purpose of the study presented here is to investigate the effectiveness and limitations of air buoyancy corrections over experimentally adjusted conditions of temperature (21-25 degrees C) and relative humidity (RH) (16-60% RH). Conditioning (24 hr) and weighing were performed inside the Archimedes M3 environmentally controlled chamber. The measurements were performed using 20 size-fractionated samples of resuspended house dust loaded onto Teflo (PTFE) filters using a Micro-Orifice Uniform Deposit Impactor representing a wide range of mass loading (7.2-3130 microg) and cut sizes (0.056-9.9 microm). By maintaining tight controls on humidity (within 0.5% RH of control setting) throughout pre- and postweighing at each stepwise increase in RH, it was possible to quantify error due to water absorption: 45% of the total mass change due to water absorption occurred between 16 and 50% RH, and 55% occurred between 50 and 60% RH. The buoyancy corrections ranged from -3.5 to +5.8 microg in magnitude and improved relative standard deviation (RSD) from 21.3% (uncorrected) to 5.6% (corrected) for a 7.2 microg sample. It is recommended that protocols for weighing low-mass particle samples (e.g., nanoparticle samples) should include buoyancy corrections and tight temperature/humidity controls. In some cases, conditioning times longer than 24 hr may be warranted.

Correlation between Organic Matter Degradation and the Rheological Performance of Waste Sludge During Anaerobic Digestion

NASA Astrophysics Data System (ADS)

Morel, Evangelina S.; Hernández-Hernándes, José A.; Méndez-Contreras, Juan M.; Cantú-Lozano, Denis

2008-07-01

Anaerobic digestion has demonstrated to be a good possibility to reduce the organic matter contents in waste activated sludge resulting in the effluents treatment. An anaerobic digestion was carried out in a 3.5 L reactor at 35 °C for a period of 20 days. An electronic thermostat controlled the temperature. The reactor was agitated at a rate of 200 rpm. The study of the rheological behavior of the waste activated sludge was done with an Anton Paar™ rheometer model MCR301 with a peltier plate for temperature control. Four-blade vane geometry was used with samples of 37 mL for determining rheological properties. Sampling (two samples) was taken every four days of anaerobic digestion through a peristaltic pump. The samples behavior was characterized by the Herschel-Bulkley model, with R2>0.99 for most cases. In all samples were found an apparent viscosity (ηap) and yield stress (τo) decrement when organic matter content diminishes. This demonstrates a relationship between rheological properties and organic matter concentration (% volatile solids). Also the flow activation energy (Ea) was calculated using the Ahrrenius correlation and samples of waste activated sludge before anaerobic digestion. In this case, samples were run in the rheometer at 200 rpm and a temperature range of 25 to 75 °C with an increment rate of 2 °C per minute. The yield stress observed was in a range of 0.93-0.18 Pa, the apparent viscosity was in a range of 0.0358-0.0010 Pa.s, the reduction of organic matter was in a range of 62.57-58.43% volatile solids and the average flow activation energy was 1.71 Calṡg-mol-1.

Cost Control. Michigan School Food Service Training Manual.

ERIC Educational Resources Information Center

Michigan State Univ., East Lansing. Cooperative Extension Service.

Cost control is the subject of this eight-lesson, three-test food service training manual. Lesson 1 deals with financial accountability and includes 17 handouts, ranging from sample balance to quarterly report sheets. Lesson 2 focuses on budgeting principles, and lesson 3 on labor controls. Professional purchasing, receiving, and inventorying…

Treatment Trials for Neonatal Seizures: The Effect of Design on Sample Size

PubMed Central

Stevenson, Nathan J.; Boylan, Geraldine B.; Hellström-Westas, Lena; Vanhatalo, Sampsa

2016-01-01

Neonatal seizures are common in the neonatal intensive care unit. Clinicians treat these seizures with several anti-epileptic drugs (AEDs) to reduce seizures in a neonate. Current AEDs exhibit sub-optimal efficacy and several randomized control trials (RCT) of novel AEDs are planned. The aim of this study was to measure the influence of trial design on the required sample size of a RCT. We used seizure time courses from 41 term neonates with hypoxic ischaemic encephalopathy to build seizure treatment trial simulations. We used five outcome measures, three AED protocols, eight treatment delays from seizure onset (Td) and four levels of trial AED efficacy to simulate different RCTs. We performed power calculations for each RCT design and analysed the resultant sample size. We also assessed the rate of false positives, or placebo effect, in typical uncontrolled studies. We found that the false positive rate ranged from 5 to 85% of patients depending on RCT design. For controlled trials, the choice of outcome measure had the largest effect on sample size with median differences of 30.7 fold (IQR: 13.7–40.0) across a range of AED protocols, Td and trial AED efficacy (p<0.001). RCTs that compared the trial AED with positive controls required sample sizes with a median fold increase of 3.2 (IQR: 1.9–11.9; p<0.001). Delays in AED administration from seizure onset also increased the required sample size 2.1 fold (IQR: 1.7–2.9; p<0.001). Subgroup analysis showed that RCTs in neonates treated with hypothermia required a median fold increase in sample size of 2.6 (IQR: 2.4–3.0) compared to trials in normothermic neonates (p<0.001). These results show that RCT design has a profound influence on the required sample size. Trials that use a control group, appropriate outcome measure, and control for differences in Td between groups in analysis will be valid and minimise sample size. PMID:27824913

Temperature Control Diagnostics for Sample Environments

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

Santodonato, Louis J; Walker, Lakeisha MH; Church, Andrew J

2010-01-01

In a scientific laboratory setting, standard equipment such as cryocoolers are often used as part of a custom sample environment system designed to regulate temperature over a wide range. The end user may be more concerned with precise sample temperature control than with base temperature. But cryogenic systems tend to be specified mainly in terms of cooling capacity and base temperature. Technical staff at scientific user facilities (and perhaps elsewhere) often wonder how to best specify and evaluate temperature control capabilities. Here we describe test methods and give results obtained at a user facility that operates a large sample environmentmore » inventory. Although this inventory includes a wide variety of temperature, pressure, and magnetic field devices, the present work focuses on cryocooler-based systems.« less

Evaluation of the External RNA Controls Consortium (ERCC) reference material using a modified Latin square design.

PubMed

Pine, P Scott; Munro, Sarah A; Parsons, Jerod R; McDaniel, Jennifer; Lucas, Anne Bergstrom; Lozach, Jean; Myers, Timothy G; Su, Qin; Jacobs-Helber, Sarah M; Salit, Marc

2016-06-24

Highly multiplexed assays for quantitation of RNA transcripts are being used in many areas of biology and medicine. Using data generated by these transcriptomic assays requires measurement assurance with appropriate controls. Methods to prototype and evaluate multiple RNA controls were developed as part of the External RNA Controls Consortium (ERCC) assessment process. These approaches included a modified Latin square design to provide a broad dynamic range of relative abundance with known differences between four complex pools of ERCC RNA transcripts spiked into a human liver total RNA background. ERCC pools were analyzed on four different microarray platforms: Agilent 1- and 2-color, Illumina bead, and NIAID lab-made spotted microarrays; and two different second-generation sequencing platforms: the Life Technologies 5500xl and the Illumina HiSeq 2500. Individual ERCC controls were assessed for reproducible performance in signal response to concentration among the platforms. Most demonstrated linear behavior if they were not located near one of the extremes of the dynamic range. Performance issues with any individual ERCC transcript could be attributed to detection limitations, platform-specific target probe issues, or potential mixing errors. Collectively, these pools of spike-in RNA controls were evaluated for suitability as surrogates for endogenous transcripts to interrogate the performance of the RNA measurement process of each platform. The controls were useful for establishing the dynamic range of the assay, as well as delineating the useable region of that range where differential expression measurements, expressed as ratios, would be expected to be accurate. The modified Latin square design presented here uses a composite testing scheme for the evaluation of multiple performance characteristics: linear performance of individual controls, signal response within dynamic range pools of controls, and ratio detection between pairs of dynamic range pools. This compact design provides an economical sample format for the evaluation of multiple external RNA controls within a single experiment per platform. These results indicate that well-designed pools of RNA controls, spiked into samples, provide measurement assurance for endogenous gene expression studies.

Psychometric Evaluation of the PROMIS Fatigue-Short Form Across Diverse Populations

PubMed Central

Ameringer, Suzanne; Elswick, R. K.; Menzies, Victoria; Robins, Jo Lynne; Starkweather, Angela; Walter, Jeanne; Gentry, Amanda Elswick; Jallo, Nancy

2016-01-01

Background The need for reliable, valid tools to measure patient-reported outcomes (PROs) is critical for both research and for evaluating treatment effects in practice. The Patient Reported Outcome Measurement Information System (PROMIS) Fatigue-Short Form v1.0 –Fatigue 7a (PROMIS F-SF) has had limited psychometric evaluation in various populations. Objectives The aim of the study is to examine psychometric properties of PROMIS F-SF item responses across various populations. Methods Data from five studies with common data elements were used in this secondary analysis. Samples from patients with fibromyalgia, sickle cell disease, cardiometabolic risk, pregnancy, and healthy controls were used. Reliability was estimated using Cronbach’s alpha. Dimensionality was evaluated with confirmatory factor analysis. Concurrent validity was evaluated by examining Pearson’s correlations between scores from the PROMIS F-SF, the Multidimensional Fatigue Symptom Inventory-Short Form (MFSI-SF), and the Brief Fatigue Inventory (BFI). Discriminant validity was evaluated by examining Pearson’s correlations between scores on the PROMIS F-SF and measures of stress and depressive symptoms. Known groups validity was assessed by comparing PROMIS F-SH scores in the clinical samples to healthy controls. Results Reliability of PROMIS F-SF scores was adequate across samples, ranging from .72 in the pregnancy sample to .88 in healthy controls. Unidimensionality was supported in each sample. Concurrent validity was strong; across the groups, correlations with scores on the MFSI-SF and BFI ranged from .60–.85. Correlations of the PROMIS-SF with measures of stress and depressive mood were moderate to strong, ranging from .37–.64. PROMIS F-SF scores were significantly higher in clinical samples, compared to healthy controls. Discussion Reliability and validity of the PROMIS F-SF were acceptable. The PROMIS F-SF is a suitable measure of fatigue across the four diverse clinical populations included in the analysis. PMID:27362514

Characteristics and Frequency of Chipping Effects in Near-Contact Gunshot Wounds.

PubMed

Amadasi, Alberto; Mazzarelli, Debora; Merli, Daniele; Brandone, Alberto; Cattaneo, Cristina

2017-05-01

The presence of "chipping" or "flaking" around the edges of gunshot entry wounds has been described among the characteristics of gunshot wounds in bone. In this study, the real frequency of such a peculiar feature was investigated. The presence of "chipping" was assessed on 22 gunshot wounds fired at a near-contact range on bovine ribs with 9-mm bullets. As controls, five samples were shot with a 3 cm range, and five from 40 cm. In 77% of cases shot at near-contact range, a detachment of small fragments of the upper layers of bone was detected, mainly with a circumferential disposition, whereas this feature was lacking in control samples. The study demonstrated the frequency of "chipping" and that it may probably be due to a combined ballistic effect of impact of the bullet itself and expansion of gases. It may be thus considered indicative of close-range shots. © 2016 American Academy of Forensic Sciences.

Experimental measurement of the plasma conductivity of Z93 and Z93P thermal control paint

NASA Technical Reports Server (NTRS)

Hillard, G. Barry

1993-01-01

Two samples each of Z93 and Z93P thermal control paint were exposed to a simulated space environment in a plasma chamber. The samples were biased through a series of voltages ranging from -200 volts to +300 volts and electron and ion currents measured. By comparing the currents to those of pure metal samples of the same size and shape, the conductivity of the samples was calculated. Measured conductivity was dependent on the bias potential in all cases. For Z93P, conductivity was approximately constant over much of the bias range and we find a value of 0.5 micro-mhos per square meter for both electron and ion current. For Z93, the dependence on bias was much more pronounced but conductivity can be said to be approximately one order of magnitude larger. In addition to presenting these results, this report documents all of the experimental data as well as the statistical analyses performed.

Dose controlled low energy electron irradiator for biomolecular films

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

Kumar, S. V. K., E-mail: svkk@tifr.res.in; Tare, Satej T.; Upalekar, Yogesh V.

2016-03-15

We have developed a multi target, Low Energy Electron (LEE), precise dose controlled irradiator for biomolecular films. Up to seven samples can be irradiated one after another at any preset electron energy and dose under UHV conditions without venting the chamber. In addition, one more sample goes through all the steps except irradiation, which can be used as control for comparison with the irradiated samples. All the samples are protected against stray electron irradiation by biasing them at −20 V during the entire period, except during irradiation. Ethernet based communication electronics hardware, LEE beam control electronics and computer interface weremore » developed in house. The user Graphical User Interface to control the irradiation and dose measurement was developed using National Instruments Lab Windows CVI. The working and reliability of the dose controlled irradiator has been fully tested over the electron energy range of 0.5 to 500 eV by studying LEE induced single strand breaks to ΦX174 RF1 dsDNA.« less

The Effect of Aquatic Exercise Therapy on Muscle Strength and Joint's Range of Motion in Hemophilia Patients.

PubMed

Kargarfard, Mehdi; Dehghadani, Mehdi; Ghias, Reza

2013-01-01

This study was to evaluate the effect of a period of aquatic exercise therapy on muscle strength and joints range of motion in hemophilia patients. This was a semiexperimental, pretest, post-test study with a control group. This semi-experimental study comprised twenty men suffering moderate hemophilia were selected by convenience sampling method from patients of a referral hospital. They were randomly assigned to intervention and control groups of equal number. The hemophilia patients who were referred to Sayedo-Shohada Hospital enrolled in this study. Twenty men suffering moderate hemophilia were selected using convenience sampling method and then divided randomly into intervention and control groups (10 patients in each group). Subjects of aquatic exercise therapy group underwent activity in water in three sessions (45-60 minutes) per week for 8 weeks, while the control group was only under follow-up and during this period did not experience any effective physical activity. The patients' muscle strength and joint range of motion were evaluated through standard laboratory tools, using an isokinetic dynamometer (Biodex, Systems III) and a standard goniometer in the beginning and at end of the study. Finally, data was analyzed using analysis of covariance (ANCOVA). The strength of the muscles around the knee joint (to perform extension and flexion movements) increased significantly in the case group while the control group experienced a significant reduction of strength in left leg, but in right leg remarkable change was observed. Range of motion in all joints was improved in the case group, while the control group did not improve significantly. The results showed that aquatic exercise therapy can be a useful method to improve joints' strength and range of motion in hemophilia patients in order to improve their daily functioning and quality of life.

A Long Range Science Rover For Future Mars Missions

NASA Technical Reports Server (NTRS)

Hayati, Samad

1997-01-01

This paper describes the design and implementation currently underway at the Jet Propulsion Laboratory of a long range science rover for future missions to Mars. The small rover prototype, called Rocky 7, is capable of long traverse. autonomous navigation. and science instrument control, carries three science instruments, and can be commanded from any computer platform and any location using the World Wide Web. In this paper we describe the mobility system, the sampling system, the sensor suite, navigation and control, onboard science instruments. and the ground command and control system.

Contamination control program for the Extreme Ultraviolet Explorer instruments

NASA Technical Reports Server (NTRS)

Ray, David C.; Malina, Roger F.; Welsh, Barry Y.; Austin, James D.; Teti, Bonnie Gray

1989-01-01

A contamination-control program has been instituted for the optical components of the EUV Explorer satellite, whose 80-900 A range performance is easily degraded by particulate and molecular contamination. Cleanliness requirements have been formulated for the design, fabrication, and test phases of these instruments; in addition, contamination-control steps have been taken which prominently include the isolation of sensitive components in a sealed optics cavity. Prelaunch monitoring systems encompass the use of quartz crystal microbalances, particle witness plates, direct flight hardware sampling, and optical witness sampling of EUV scattering and reflectivity.

Rapid, Contactless and Non-Destructive Testing of Chemical Composition of Samples

NASA Astrophysics Data System (ADS)

Ivanov, O.; Vaseashta, A.; Stoychev, L.

Our results demonstrate that a new effect can be induced in each solid in a wide spectral range of electromagnetic irradiation. In the present manuscript we prove experimentally that one of the possible applications of this effect is for an express contactless control of the chemical composition of a series of samples, in this case, coins. The method has wide applicability ranging from defense and homeland security to several applications requiring rapid and nondestructive identification of chemical composition.

Demonstration of Physical Separation/Leaching Methods for the Remediation of Heavy Metals Contaminated Soils at Small Arms Ranges.

DTIC Science & Technology

1997-09-01

8.8 WIND SOCK 8.9 SILT TRAP 8.10 BATTELLE SAMPLE PREPARATION AREA 8.11 RANGE 5 EXCAVATION PLAN 8.12 COMPONENTS THAT NEEDED MAINTENANCE, REPAIR...Pad Details 47 18 Soil Storage Bins 48 19 Power Distribution Station 49 20 Water Supply System 50 21 Wind Sock 50 22 Sample Preparation...washwater). Better process control, especially soil dewatering, would have reduced this occasional nuisance. The odor threshold for this acid is

Serum concentrations of brain-derived neurotrophic factor (BDNF) are decreased in colorectal cancer patients.

PubMed

Brierley, G V; Priebe, I K; Purins, L; Fung, K Y C; Tabor, B; Lockett, T; Nice, E; Gibbs, P; Tie, J; McMurrick, P; Moore, J; Ruszkiewicz, A; Burgess, A; Cosgrove, L J

2013-01-01

To determine the usefulness of brain-derived neurotrophic factor (BDNF) as a diagnostic biomarker for colorectal cancer (CRC). ELISA immunoassay was used to examine BDNF concentrations in the sera of two different retrospective cohorts consisting of CRC patients and age/gender matched controls. Cohort 1 consisted of 99 controls and 97 CRC patients, whereas cohort 2 consisted of 47 controls and 91 CRC patients. In cohort 1, the median concentration of BDNF was significantly (p< 0.0001) lower in CRC patient samples (18.8 ng/mL, range 4.0-56.5 ng/mL) than control samples (23.4 ng/mL, range 3.0-43.1 ng/mL). This finding was validated in an independent patient cohort (CRC patients: 23.0 ng/mL, range 6.0-45.9 ng/mL; control patients: 32.3 ng/mL, range 14.2-62.4 ng/mL). BDNF concentrations did not differ significantly between Dukes' staging in the patient cohort, however patients with Stages A, B, C and D (p< 0.01 for each stage) tumours had significantly reduced BDNF levels compared to healthy controls. Receiver operating characteristic analysis was performed to determine the ability of BDNF to discriminate between healthy controls and those with CRC. At 95% specificity, BDNF concentrations distinguished CRC patients with 25% and 18% sensitivity, respectively, in cohorts 1 and 2 (cohort 1: AUC=0.79, 95% CI 0.70-0.87; cohort 2: AUC =0.69, 95% CI 0.61-0.76). The serum levels of BDNF were significantly lower in colorectal cancer patients when compared to a control population, and this did not differ between different Dukes' stages.

Repeat sample intraocular pressure variance in induced and naturally ocular hypertensive monkeys.

PubMed

Dawson, William W; Dawson, Judyth C; Hope, George M; Brooks, Dennis E; Percicot, Christine L

2005-12-01

To compare repeat-sample means variance of laser induced ocular hypertension (OH) in rhesus monkeys with the repeat-sample mean variance of natural OH in age-range matched monkeys of similar and dissimilar pedigrees. Multiple monocular, retrospective, intraocular pressure (IOP) measures were recorded repeatedly during a short sampling interval (SSI, 1-5 months) and a long sampling interval (LSI, 6-36 months). There were 5-13 eyes in each SSI and LSI subgroup. Each interval contained subgroups from the Florida with natural hypertension (NHT), induced hypertension (IHT1) Florida monkeys, unrelated (Strasbourg, France) induced hypertensives (IHT2), and Florida age-range matched controls (C). Repeat-sample individual variance means and related IOPs were analyzed by a parametric analysis of variance (ANOV) and results compared to non-parametric Kruskal-Wallis ANOV. As designed, all group intraocular pressure distributions were significantly different (P < or = 0.009) except for the two (Florida/Strasbourg) induced OH groups. A parametric 2 x 4 design ANOV for mean variance showed large significant effects due to treatment group and sampling interval. Similar results were produced by the nonparametric ANOV. Induced OH sample variance (LSI) was 43x the natural OH sample variance-mean. The same relationship for the SSI was 12x. Laser induced ocular hypertension in rhesus monkeys produces large IOP repeat-sample variance mean results compared to controls and natural OH.

Environmental assessment of a wood-waste-fired industrial firetube boiler. Volume 1. Technical results. Final report, January 1981-March 1984

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

DeRosier, R.; Waterland, L.R.

1987-03-01

The report gives emission results from field tests of a wood-waste-fired industrial firetube boiler. Emission measurements included: continuous monitoring of flue gas emissions: source assessment sampling system (SASS) sampling of the flue-gas with subsequent laboratory analysis of samples to give total flue gas organics in two boiling point ranges, compound category information within these ranges, specific quantitation of the semivolatile organic priority pollutants, and flue gas concentrations of 65 trace elements; Method 5 sampling for particulates; controlled condensation system (CSS) sampling for SO/sub 2/ and SO/sub 3/; and grab sampling of boiler bottom ash for trace element content determinations. Totalmore » organic emissions from the boiler were 5.7 mg/dscm, about 90% of which consisted of volatile compounds.« less

Presence of heterocyclic amine carcinogens in home-cooked and fast-food camel meat burgers commonly consumed in Saudi Arabia.

PubMed

Rizwan Khan, Mohammad; Naushad, Mu; Abdullah Alothman, Zeid

2017-05-10

Heterocyclic amines (HCAs) are formed by cooking protein-rich foods, for instance, meat and fish, and are listed as possible human carcinogens. In the present study, the presence of five potential HCAs (IQ, MeIQ, MeIQx, 4,8-DiMeIQx, and PhIP) in cooked camel meat burgers was analyzed for the first time. The analysis was performed in home-cooked and fast-food burger samples containing food additives. The applied cooking technique for the home-cooked samples was pan frying for a controlled cooking time and temperature. In the control cooked meat samples (samples that contained no food additives), the concentrations of MeIQx, 4,8-DiMeIQx, and PhIP ranged from 2.47 ng/g to 4.89 ng/g, whereas IQ and MeIQ were found to be below the limit of quantification. The concentrations contents of MeIQx, 4,8-DiMeIQx, and PhIP in the home-cooked and fast-food samples ranged from 1.52 ng/g to 2.13 ng/g and 1.85 ng/g to 3.46 ng/g, respectively. IQ and MeIQ were not detected in either type of sample. In comparison to the control samples, the home-cooked and fast-food samples produced lower levels of HCAs. Such observations could result from the existence of antioxidants in incorporated food additives, which induce pro-oxidative effects with the successive formation and/or scavenging of free radicals.

Airborne concentrations of methylene diphenyl diisocyanate (MDI) in North American wood mills during the manufacturing of oriented strand board (OSB).

PubMed

Karoly, William J; Flatley, John J; Stevenson, Ralph D; Bowers, John D

2004-12-01

Air monitoring data were collected from industrial hygiene surveys over an 8-year period in oriented strand board (OSB) mills. Personal samples were taken to evaluate potential employee exposures to MDI. Area samples were taken to determine the effectiveness of control measures used in the mills to prevent fugitive emissions of wood dust, MDI, and MDI-coated wood dust from the OSB manufacturing process. Personal sampling results (578 samples covering 11 different job categories) ranged from 0.0002-0.524 mg/m3, with a GM = 0.001 and GSD = 3.71. Area sampling results (1657 samples covering 14 stationary locations in the mills) ranged from 0.0002-2.5 mg/m3, with a GM = 0.004 and GSD = 5.52. The statistical range of the data suggests high variability. While exposures to MDI above the established limits (0.051 mg/m3, 8-hour time-weighted average, 0.2 mg/m3, ceiling) can and do occur when engineering controls are not maintained and/or proper work practices and personal protective equipment are not followed/used for certain high exposure potential tasks, the data indicate that over 97% of the personal and 92% of the area sampling results are less than 0.051 mg/m3. Wipe testing was performed to determine the presence of removable, unreacted diisocyanates (NCO functional groups)from various surfaces. Positive results were found in about 13% of the wipe tests on surfaces confined to the blender, forming line, and hopper deck process areas.

Investigating Violence and Control Dyadically in a Help-Seeking Sample from Mozambique

PubMed Central

Graham-Kevan, Nicola; Zacarias, Antonio Eugenio; Soares, Joaquim J. F.

2012-01-01

A sample of 1442 women attending a Forensic Healthcare Service provided information on their own and their partners' use of controlling behaviors, partner violence, and sexual abuse, as well as their own experiences of childhood abuse. Using Johnson's typology, the relationships were categorized as Nonviolent, Intimate Terrorism, or Situational Couple Violence. Findings suggest that help-seeking women's experiences of intimate violence may be diverse, with their roles ranging from victim to perpetrator. PMID:22666138

β-trace protein as a diagnostic marker for perilymphatic fluid fistula: a prospective controlled pilot study to test a sample collection technique.

PubMed

Bachmann-Harildstad, Gregor; Stenklev, Niels Christian; Myrvoll, Elin; Jablonski, Greg; Klingenberg, Olav

2011-01-01

The diagnosis of perilymphatic fluid (PLF) fistula is still challenging. Perilymphatic fluid fistula is one possible complication after stapedotomy or cochlear implant surgery. We have performed a prospective diagnostic pilot study to further investigate β-trace protein (β-TP) as a marker for PLF fistula. In this pilot study, we tested the sensitivity of the β-TP marker using a simple method for sample collection from the tympanic cavity. Prospective controlled diagnostic study. Two-center tertiary referral hospitals. A total of 35 adult patients undergoing ear surgery were included. Subjects were divided into 2 groups: 1) 19 patients undergoing stapedotomy were investigated for PLF fistula in samples obtained from the tympanic cavity and 2) 16 patients undergoing myringoplasty were investigated for PLF fistula in samples from the tympanic cavity. This group served as the control. Mean age +/- SD at surgery was 49.9 +/- 8.0 years in the study group and 39.69 +/- 15.47 years in the control group. β-Trace protein (prostaglandin D synthase) in tympanic cavity samples and serum samples was analyzed. The samples were collected by gradually filling the tympanic cavity with 100 to 200 μl sodium chloride and by immediately collecting a volume of 60 to 100 μl in a mucus specimen set container. The concentration of β-TP was quantified using laser nephelometry. The median β-TP in the study group was 0.8 mg/L (range, 0.05-4.5 mg/L). In the control group, the median β-TP value was 0.16 mg/L (range, 0.01-0.36 mg/L). Thirty-five percent of the values in the study group were below the highest value in the negative control group. The β-TP values of the tympanic cavity samples were significantly higher in the study group than in controls (p = 0.0001). The serum values were 0.55 +/- 0.18 and 0.53 +/- 0.11 mg/L, respectively. It may be feasible to test for PLF fistula using β-TP in samples from the tympanic cavity. Our results, however, suggest a relative low diagnostic sensitivity, given a cutoff that is set to obtain a high specificity when using a simple sample collection method. Furthermore, the test does not permit the distinction between PLF fistula and cerebrospinal fluid fistula. Further studies should focus on minimal dilution at sampling and on minimizing sample volumes.

Phase-locked-loop-based delay-line-free picosecond electro-optic sampling system

NASA Astrophysics Data System (ADS)

Lin, Gong-Ru; Chang, Yung-Cheng

2003-04-01

A delay-line-free, high-speed electro-optic sampling (EOS) system is proposed by employing a delay-time-controlled ultrafast laser diode as the optical probe. Versatile optoelectronic delay-time controllers (ODTCs) based on modified voltage-controlled phase-locked-loop phase-shifting technologies are designed for the laser. The integration of the ODTC circuit and the pulsed laser diode has replaced the traditional optomechanical delay-line module used in the conventional EOS system. This design essentially prevents sampling distortion from misalignment of the probe beam, and overcomes the difficulty in sampling free-running high-speed transients. The maximum tuning range, error, scanning speed, tuning responsivity, and resolution of the ODTC are 3.9π (700°), <5% deviation, 25-2405 ns/s, 0.557 ps/mV, and ˜1 ps, respectively. Free-running wave forms from the analog, digital, and pulsed microwave signals are sampled and compared with those measured by the commercial apparatus.

Temperament factors and dimensional, latent bifactor models of child psychopathology: Transdiagnostic and specific associations in two youth samples.

PubMed

Hankin, Benjamin L; Davis, Elysia Poggi; Snyder, Hannah; Young, Jami F; Glynn, Laura M; Sandman, Curt A

2017-06-01

Common emotional and behavioral symptoms co-occur and are associated with core temperament factors. This study investigated links between temperament and dimensional, latent psychopathology factors, including a general common psychopathology factor (p factor) and specific latent internalizing and externalizing liabilities, as captured by a bifactor model, in two independent samples of youth. Specifically, we tested the hypothesis that temperament factors of negative affectivity (NA), positive affectivity (PA), and effortful control (EC) could serve as both transdiagnostic and specific risks in relation to recent bifactor models of child psychopathology. Sample 1 included 571 youth (average age 13.6, SD =2.37, range 9.3-17.5) with both youth and parent report. Sample 2 included 554 preadolescent children (average age 7.7, SD =1.35, range =5-11 years) with parent report. Structural equation modeling showed that the latent bifactor models fit in both samples. Replicated in both samples, the p factor was associated with lower EC and higher NA (transdiagnostic risks). Several specific risks replicated in both samples after controlling for co-occurring symptoms via the p factor: internalizing was associated with higher NA and lower PA, lower EC related to externalizing problems. Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.

Magnetic properties of Apollo 14 breccias and their correlation with metamorphism.

NASA Technical Reports Server (NTRS)

Gose, W. A.; Pearce, G. W.; Strangway, D. W.; Larson, E. E.

1972-01-01

The magnetic properties of Apollo 14 breccias can be explained in terms of the grain size distribution of the interstitial iron which is directly related to the metamorphic grade of the sample. In samples 14049 and 14313 iron grains less than 500 A in diameter are dominant as evidenced by a Richter-type magnetic aftereffect and hysteresis measurements. Both samples are of lowest metamorphic grade. The medium metamorphic-grade sample 14321 and the high-grade sample 14312 both show a logarithmic time-dependence of the magnetization indicative of a wide range of relaxation times and thus grain sizes, but sample 14321 contains a stable remanent magnetization whereas sample 14312 does not. This suggests that small multidomain particles (less than 1 micron) are most abundant in sample 14321 while sample 14312 is magnetically controlled by grains greater than 1 micron. The higher the metamorphic grade, the larger the grain size of the iron controlling the magnetic properties.

Experimental attrition rates of bed-material sediment from geologic provinces of Western Oregon and their application to regional sediment models

NASA Astrophysics Data System (ADS)

Mangano, J.; O'Connor, J. E.; Jones, K. L.; Wallick, R.

2011-12-01

Many topographic, hydrologic, and land use variables affect the supply and transport of bed-material in rivers, but the underlying geology is a key factor controlling both the volume of introduced material and the attrition of bed-material as it moves downstream. Recent and ongoing USGS river studies in Western Oregon document strong links between geologic province and bed-material transport. Rivers originating in the Mesozoic metamorphic and intrusive igneous rocks of the Klamath terranes of southwestern Oregon have the greatest gravel transport rates (and channel and valley-bottom morphologies reflecting high bed-material fluxes), whereas the generally lesser amounts of gravel in streams that drain Oregon's Coast Range and western Cascade Range owes in large part to Tertiary sedimentary and volcanic units underlying most of these basins. Aspects of these differences are controlled by supply as well as clast attrition. Here we aim to quantify bed-material attrition rates associated with the five main geologic provinces of Western Oregon: the Klamath terranes, Western Cascades, High Cascades, Coast Range sedimentary rocks, and Coast Range volcanic rocks. Bed-material samples were collected throughout the region from streams that drain a single geologic province and tumbled with a lapidary tumbler to determine relative attrition rates. Two kilograms of each sample were sorted into an initial distribution of clast sizes (from 16 to 64mm) and tumbled, with periodic breaks to reweigh and sieve the sample. Results show marked differences in attrition rates, with the sedimentary rocks of the Coast Range having weight loss coefficients between 1.206 and 0.211/km, orders of magnitude greater than all of the other sampled provinces. For comparison, bed material from the Klamath terranes have weight loss coefficients ranging from 0.013 to 0.005/km, and a control sample of quartzite clasts (from the Klamath terranes) has a weight loss coefficient of 0.001/km. These results confirm that bed-material attrition is an important process affecting bed-material supply and transport, and will allow for more complete development of regional bed-material sediment budgets in ongoing efforts to understand patterns of gravel abundance and channel morphology in rivers of Western Oregon.

Magnetism and atomic short-range order in Ni-Rh alloys

NASA Astrophysics Data System (ADS)

Carnegie, D. W., Jr.; Claus, H.

1984-07-01

Low-field ac susceptibility measurements of Ni-Rh samples of various concentrations are presented. Giant effects of the metallurgical state on the magnetic ordering temperature are associated with changes in the degree of atomic short-range order. By careful control of this degree of short-range order, it is possible to demonstrate the existence of a spin-glass state in Ni-Rh alloys.

Temporal Wind Pairs for Space Launch Vehicle Capability Assessment and Risk Mitigation

NASA Technical Reports Server (NTRS)

Decker, Ryan K.; Barbre, Robert E., Jr.

2015-01-01

Space launch vehicles incorporate upper-level wind assessments to determine wind effects on the vehicle and for a commit to launch decision. These assessments make use of wind profiles measured hours prior to launch and may not represent the actual wind the vehicle will fly through. Uncertainty in the winds over the time period between the assessment and launch introduces uncertainty in assessment of vehicle controllability and structural integrity that must be accounted for to ensure launch safety. Temporal wind pairs are used in engineering development of allowances to mitigate uncertainty. Five sets of temporal wind pairs at various times (0.75, 1.5, 2, 3 and 4-hrs) at the United States Air Force Eastern Range and Western Range, as well as the National Aeronautics and Space Administration's Wallops Flight Facility are developed for use in upper-level wind assessments on vehicle performance. Historical databases are compiled from balloon-based and vertically pointing Doppler radar wind profiler systems. Various automated and manual quality control procedures are used to remove unacceptable profiles. Statistical analyses on the resultant wind pairs from each site are performed to determine if the observed extreme wind changes in the sample pairs are representative of extreme temporal wind change. Wind change samples in the Eastern Range and Western Range databases characterize extreme wind change. However, the small sample sizes in the Wallops Flight Facility databases yield low confidence that the sample population characterizes extreme wind change that could occur.

Temporal Wind Pairs for Space Launch Vehicle Capability Assessment and Risk Mitigation

NASA Technical Reports Server (NTRS)

Decker, Ryan K.; Barbre, Robert E., Jr.

2014-01-01

Space launch vehicles incorporate upper-level wind assessments to determine wind effects on the vehicle and for a commit to launch decision. These assessments make use of wind profiles measured hours prior to launch and may not represent the actual wind the vehicle will fly through. Uncertainty in the winds over the time period between the assessment and launch introduces uncertainty in assessment of vehicle controllability and structural integrity that must be accounted for to ensure launch safety. Temporal wind pairs are used in engineering development of allowances to mitigate uncertainty. Five sets of temporal wind pairs at various times (0.75, 1.5, 2, 3 and 4-hrs) at the United States Air Force Eastern Range and Western Range, as well as the National Aeronautics and Space Administration's Wallops Flight Facility are developed for use in upper-level wind assessments on vehicle performance. Historical databases are compiled from balloon-based and vertically pointing Doppler radar wind profiler systems. Various automated and manual quality control procedures are used to remove unacceptable profiles. Statistical analyses on the resultant wind pairs from each site are performed to determine if the observed extreme wind changes in the sample pairs are representative of extreme temporal wind change. Wind change samples in the Eastern Range and Western Range databases characterize extreme wind change. However, the small sample sizes in the Wallops Flight Facility databases yield low confidence that the sample population characterizes extreme wind change that could occur.

Anesthesia and blood sampling of wild big brown bats (eptesicus fuscus) with an assessment of impacts on survival.

PubMed

Wimsatt, Jeffrey; O'Shea, Thomas J; Ellison, Laura E; Pearce, Roger D; Price, Valerie R

2005-01-01

We anesthetized and blood sampled wild big brown bats (Eptesicus fuscus) in Fort Collins, Colorado (USA) in 2001 and 2002 and assessed effects on survival. Inhalant anesthesia was delivered into a specially designed restraint and inhalation capsule that minimized handling and bite exposures. Bats were immobilized an average of 9.1+/-5.1 (SD) min (range 1-71, n=876); blood sample volumes averaged 58+/-12 microl (range 13-126, n=718). We randomly selected control (subject to multiple procedures before release) and treatment (control procedures plus inhalant anesthesia and 1% of body weight blood sampling) groups in 2002 to assess treatment effects on daily survival over a 14-day period for adult female and volant juvenile bats captured at maternity roosts in buildings. We monitored survival after release using passive integrated transponder tag detection hoops placed at openings to selected roosts. Annual return rates of bats sampled in 2001 were used to assess long-term outcomes. Comparison of 14-day maximum-likelihood daily survival estimates from control (86 adult females, 92 volant juveniles) and treated bats (187 adult females, 87 volant juveniles) indicated no adverse effect from anesthesia and blood sampling (juveniles: chi2=22.22, df=27, P>0.05; adults: chi2=9.72, df=18, P>0.05). One-year return rates were similar among adult female controls (81%, n=72, 95% confidence interval [CI]=70-91%), females treated once (82%, n=276, 95% CI=81-84%), and females treated twice (84%, n=50, 95% CI=74-94%). Lack of an effect was also noted in 1-yr return rates of juvenile female controls (55%, n=29, 95% CI=37-73%), juveniles treated once (66%, n=113, 95% CI=58-75%), and juveniles treated twice (71%, n=17, 95% CI=49-92%). These data suggest that anesthesia and blood sampling for health monitoring did not measurably affect survival of adult female and volant juvenile big brown bats.

Quantitative Method for Analysis of Hydrocodone, Hydromorphone and Norhydrocodone in Human Plasma by Liquid Chromatography-tandem Mass Spectrometry

DTIC Science & Technology

2013-03-01

ratio ranges obtained for the six standards. Twelve samples were analyzed to demonstrate the efficiency of the extraction procedure. Drug and internal...frozen (−70 ◦C). Refrigerated samples were tested after 2 months of storage ; frozen samples were tested for up to 1 year from stor- age date. The...freeze–thaw stability was evaluated by analyzing three subject samples with known drug concentrations and two quality control samples at concentrations

Quality-assurance data for routine water analyses by the U.S. Geological Survey laboratory in Troy, New York - July 2003 through June 2005

USGS Publications Warehouse

Lincoln, Tricia A.; Horan-Ross, Debra A.; McHale, Michael R.; Lawrence, Gregory B.

2009-01-01

The laboratory for analysis of low-ionic-strength water at the U.S. Geological Survey (USGS) Water Science Center in Troy, N.Y., analyzes samples collected by USGS projects throughout the Northeast. The laboratory's quality-assurance program is based on internal and interlaboratory quality-assurance samples and quality-control procedures that were developed to ensure proper sample collection, processing, and analysis. The quality-assurance and quality-control data were stored in the laboratory's Lab Master data-management system, which provides efficient review, compilation, and plotting of data. This report presents and discusses results of quality-assurance and quality control samples analyzed from July 2003 through June 2005. Results for the quality-control samples for 20 analytical procedures were evaluated for bias and precision. Control charts indicate that data for five of the analytical procedures were occasionally biased for either high-concentration or low-concentration samples but were within control limits; these procedures were: acid-neutralizing capacity, total monomeric aluminum, pH, silicon, and sodium. Seven of the analytical procedures were biased throughout the analysis period for the high-concentration sample, but were within control limits; these procedures were: dissolved organic carbon, chloride, nitrate (ion chromatograph), nitrite, silicon, sodium, and sulfate. The calcium and magnesium procedures were biased throughout the analysis period for the low-concentration sample, but were within control limits. The total aluminum and specific conductance procedures were biased for the high-concentration and low-concentration samples, but were within control limits. Results from the filter-blank and analytical-blank analyses indicate that the procedures for 17 of 18 analytes were within control limits, although the concentrations for blanks were occasionally outside the control limits. The data-quality objective was not met for dissolved organic carbon. Sampling and analysis precision are evaluated herein in terms of the coefficient of variation obtained for triplicate samples in the procedures for 18 of the 22 analytes. At least 85 percent of the samples met data-quality objectives for all analytes except total monomeric aluminum (82 percent of samples met objectives), total aluminum (77 percent of samples met objectives), chloride (80 percent of samples met objectives), fluoride (76 percent of samples met objectives), and nitrate (ion chromatograph) (79 percent of samples met objectives). The ammonium and total dissolved nitrogen did not meet the data-quality objectives. Results of the USGS interlaboratory Standard Reference Sample (SRS) Project indicated good data quality over the time period, with ratings for each sample in the satisfactory, good, and excellent ranges or less than 10 percent error. The P-sample (low-ionic-strength constituents) analysis had one marginal and two unsatisfactory ratings for the chloride procedure. The T-sample (trace constituents)analysis had two unsatisfactory ratings and one high range percent error for the aluminum procedure. The N-sample (nutrient constituents) analysis had one marginal rating for the nitrate procedure. Results of Environment Canada's National Water Research Institute (NWRI) program indicated that at least 84 percent of the samples met data-quality objectives for 11 of the 14 analytes; the exceptions were ammonium, total aluminum, and acid-neutralizing capacity. The ammonium procedure did not meet data quality objectives in all studies. Data-quality objectives were not met in 23 percent of samples analyzed for total aluminum and 45 percent of samples analyzed acid-neutralizing capacity. Results from blind reference-sample analyses indicated that data-quality objectives were met by at least 86 percent of the samples analyzed for calcium, chloride, fluoride, magnesium, pH, potassium, sodium, and sulfate. Data-quality objectives were not met by samples analyzed for fluoride. 

Predictors of social anxiety in an opioid dependent sample and a control sample.

PubMed

Shand, Fiona L; Degenhardt, Louisa; Nelson, Elliot C; Mattick, Richard P

2010-01-01

Compared to other mental health problems, social anxiety is under-acknowledged amongst opioid dependent populations. This study aimed to assess levels of social anxiety and identify its predictors in an opioid dependent sample and a matched control group. Opioid dependent participants (n=1385) and controls (n=417) completed the Social Interaction Anxiety Scale (SIAS), the Social Phobia Scale (SPS) and a diagnostic interview. Regression analyses were used to test a range of predictors of social anxiety. Opioid dependent cases had higher mean scores on both scales compared to controls. Predictors of social anxiety centred on emotional rejection in childhood, either by parents or peers. For opioid dependent cases, but not controls, lifetime non-opioid substance dependence (cannabis, sedatives, and tobacco) was associated with higher levels of social anxiety. However, much of the variance in social anxiety remains unexplained for this population.

Predictors of social anxiety in an opioid dependent sample and a control sample

PubMed Central

Shand, Fiona L.; Degenhardt, Louisa; Nelson, Elliot C.; Mattick, Richard P.

2010-01-01

Compared to other mental health problems, social anxiety is under-acknowledged amongst opioid dependent populations. This study aimed to assess levels of social anxiety and identify its predictors in an opioid dependent sample and a matched control group. Opioid dependent participants (n = 1385) and controls (n = 417) completed the Social Interaction Anxiety Scale (SIAS), the Social Phobia Scale (SPS) and a diagnostic interview. Regression analyses were used to test a range of predictors of social anxiety. Opioid dependent cases had higher mean scores on both scales compared to controls. Predictors of social anxiety centred on emotional rejection in childhood, either by parents or peers. For opioid dependent cases, but not controls, lifetime non-opioid substance dependence (cannabis, sedatives, and tobacco) was associated with higher levels of social anxiety. However, much of the variance in social anxiety remains unexplained for this population. PMID:19775865

40 CFR 92.129 - Exhaust sample analysis.

Code of Federal Regulations, 2012 CFR

2012-07-01

... the span drift between the pre-analysis and post-analysis checks on any range used may exceed 3... (CONTINUED) CONTROL OF AIR POLLUTION FROM LOCOMOTIVES AND LOCOMOTIVE ENGINES Test Procedures § 92.129 Exhaust... and span each range to be used on each analyzer used prior to the beginning of the test sequence. The...

40 CFR 92.129 - Exhaust sample analysis.

Code of Federal Regulations, 2013 CFR

2013-07-01

... the span drift between the pre-analysis and post-analysis checks on any range used may exceed 3... (CONTINUED) CONTROL OF AIR POLLUTION FROM LOCOMOTIVES AND LOCOMOTIVE ENGINES Test Procedures § 92.129 Exhaust... and span each range to be used on each analyzer used prior to the beginning of the test sequence. The...

40 CFR 92.129 - Exhaust sample analysis.

Code of Federal Regulations, 2011 CFR

2011-07-01

... the span drift between the pre-analysis and post-analysis checks on any range used may exceed 3... (CONTINUED) CONTROL OF AIR POLLUTION FROM LOCOMOTIVES AND LOCOMOTIVE ENGINES Test Procedures § 92.129 Exhaust... and span each range to be used on each analyzer used prior to the beginning of the test sequence. The...

40 CFR 92.129 - Exhaust sample analysis.

Code of Federal Regulations, 2010 CFR

2010-07-01

... the span drift between the pre-analysis and post-analysis checks on any range used may exceed 3... (CONTINUED) CONTROL OF AIR POLLUTION FROM LOCOMOTIVES AND LOCOMOTIVE ENGINES Test Procedures § 92.129 Exhaust... and span each range to be used on each analyzer used prior to the beginning of the test sequence. The...

Interventions Used with an Australian Sample of Preschool Children with Autism Spectrum Disorders

ERIC Educational Resources Information Center

Carter, Mark; Roberts, Jacqueline; Williams, Katrina; Evans, David; Parmenter, Trevor; Silove, Natalie; Clark, Trevor; Warren, Anthony

2011-01-01

This study examined the previous and current range of educational, therapy, medical and CAM interventions used by a clearly described Australian sample of 84 families of preschool-aged children with autism spectrum disorders who were enrolled in a controlled trial of early intervention services. With regard to educational and therapy…

Environmental assessment of a wood-waste-fired industrial firetube boiler. Volume 2. Data supplement. Final report, January 1981-March 1984

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

DeRosier, R.; Waterland, L.R.

1987-03-01

The report gives emission results from field tests of a wood-waste-fired industrial firetube boiler. Emission measurements included: continuous monitoring of flue-gas emissions; source assessment sampling system (SASS) sampling of the flue gas with subsequent laboratory analysis of samples to give total flue-gas organics in two boiling-point ranges, compound category information within these ranges, specific quantitation of the semivolatile organic priority pollutants, and flue-gas concentrations of 65 trace elements; Method 5 sampling for particulates; controlled condensation system (CSS) sampling for SO/sub 2/ and SO/sub 3/; and grab sampling of boiler bottom ash for trace-element-content determinations. Emission levels of five polycyclic organicmore » matter species and phenol were quantitated: except for naphthalene, all were emitted at less than 0.4 microgram/dscm.« less

Light beam range finder

DOEpatents

McEwan, Thomas E.

1998-01-01

A "laser tape measure" for measuring distance which includes a transmitter such as a laser diode which transmits a sequence of electromagnetic pulses in response to a transmit timing signal. A receiver samples reflections from objects within the field of the sequence of visible electromagnetic pulses with controlled timing, in response to a receive timing signal. The receiver generates a sample signal in response to the samples which indicates distance to the object causing the reflections. The timing circuit supplies the transmit timing signal to the transmitter and supplies the receive timing signal to the receiver. The receive timing signal causes the receiver to sample the reflection such that the time between transmission of pulses in the sequence in sampling by the receiver sweeps over a range of delays. The transmit timing signal causes the transmitter to transmit the sequence of electromagnetic pulses at a pulse repetition rate, and the received timing signal sweeps over the range of delays in a sweep cycle such that reflections are sampled at the pulse repetition rate and with different delays in the range of delays, such that the sample signal represents received reflections in equivalent time. The receiver according to one aspect of the invention includes an avalanche photodiode and a sampling gate coupled to the photodiode which is responsive to the received timing signal. The transmitter includes a laser diode which supplies a sequence of visible electromagnetic pulses. A bright spot projected on to the target clearly indicates the point that is being measured, and the user can read the range to that point with precision of better than 0.1%.

Light beam range finder

DOEpatents

McEwan, T.E.

1998-06-16

A ``laser tape measure`` for measuring distance is disclosed which includes a transmitter such as a laser diode which transmits a sequence of electromagnetic pulses in response to a transmit timing signal. A receiver samples reflections from objects within the field of the sequence of visible electromagnetic pulses with controlled timing, in response to a receive timing signal. The receiver generates a sample signal in response to the samples which indicates distance to the object causing the reflections. The timing circuit supplies the transmit timing signal to the transmitter and supplies the receive timing signal to the receiver. The receive timing signal causes the receiver to sample the reflection such that the time between transmission of pulses in the sequence in sampling by the receiver sweeps over a range of delays. The transmit timing signal causes the transmitter to transmit the sequence of electromagnetic pulses at a pulse repetition rate, and the received timing signal sweeps over the range of delays in a sweep cycle such that reflections are sampled at the pulse repetition rate and with different delays in the range of delays, such that the sample signal represents received reflections in equivalent time. The receiver according to one aspect of the invention includes an avalanche photodiode and a sampling gate coupled to the photodiode which is responsive to the received timing signal. The transmitter includes a laser diode which supplies a sequence of visible electromagnetic pulses. A bright spot projected on to the target clearly indicates the point that is being measured, and the user can read the range to that point with precision of better than 0.1%. 7 figs.

Estimating parasitic sea lamprey abundance in Lake Huron from heterogenous data sources

USGS Publications Warehouse

Young, Robert J.; Jones, Michael L.; Bence, James R.; McDonald, Rodney B.; Mullett, Katherine M.; Bergstedt, Roger A.

2003-01-01

The Great Lakes Fishery Commission uses time series of transformer, parasitic, and spawning population estimates to evaluate the effectiveness of its sea lamprey (Petromyzon marinus) control program. This study used an inverse variance weighting method to integrate Lake Huron sea lamprey population estimates derived from two estimation procedures: 1) prediction of the lake-wide spawning population from a regression model based on stream size and, 2) whole-lake mark and recapture estimates. In addition, we used a re-sampling procedure to evaluate the effect of trading off sampling effort between the regression and mark-recapture models. Population estimates derived from the regression model ranged from 132,000 to 377,000 while mark-recapture estimates of marked recently metamorphosed juveniles and parasitic sea lampreys ranged from 536,000 to 634,000 and 484,000 to 1,608,000, respectively. The precision of the estimates varied greatly among estimation procedures and years. The integrated estimate of the mark-recapture and spawner regression procedures ranged from 252,000 to 702,000 transformers. The re-sampling procedure indicated that the regression model is more sensitive to reduction in sampling effort than the mark-recapture model. Reliance on either the regression or mark-recapture model alone could produce misleading estimates of abundance of sea lampreys and the effect of the control program on sea lamprey abundance. These analyses indicate that the precision of the lakewide population estimate can be maximized by re-allocating sampling effort from marking sea lampreys to trapping additional streams.

Development and analytical validation of an enzyme linked immunosorbent assay for the measurement of canine gastric lipase immunoreactivity in serum

PubMed Central

2004-01-01

Abstract The objective of this study was to develop and analytically validate an enzyme linked immunosorbent assay (ELISA) for measurement of canine gastric lipase immunoreactivity (cGLI). A sandwich ELISA was developed using canine gastric lipase (cGL) purified from canine stomachs and polyclonal antibodies directed against cGL, raised in rabbits and purified by affinity chromatography. The assay was validated by determination of sensitivity, working range, linearity, accuracy, precision, reproducibility, and the upper limit of the control range by determining the 97.5th percentile of serum cGLI concentration in 74 healthy canines. Sensitivity and working range in serum were 200 ng/L and 200 to 39 160 ng/L, respectively. Observed to expected ratios for dilutional parallelism for 3 serum samples and 3 dilutions ranged from 86.1% to 244.2% (mean ± standard deviation [s]; 125.4% ± 48.2%). Observed to expected ratios for spiking recoveries for 3 serum samples and 6 spiking concentrations ranged from 66.4% to 152.5% (mean ± s; 104.5% ± 22.9%). Intra-assay and interassay variabilities for 3 different serum samples were 25.5%, 9.4%, and 13.4% and 26.0%, 17.2%, and 14.4%, respectively. The upper limit of the control range for serum cGLI was 662 ng/L. We concluded that the ELISA for cGLI described here is highly sensitive and shows a wide working range. However, the validation characteristics for this assay are suboptimal and below values of approximately 2.000 ng/L the assay is more semiquantitative in nature. Despite its limitations, whether this assay is useful for the diagnosis of canine gastric disorders remains to be determined. PMID:15352539

Total protein analysis as a reliable loading control for quantitative fluorescent Western blotting.

PubMed

Eaton, Samantha L; Roche, Sarah L; Llavero Hurtado, Maica; Oldknow, Karla J; Farquharson, Colin; Gillingwater, Thomas H; Wishart, Thomas M

2013-01-01

Western blotting has been a key technique for determining the relative expression of proteins within complex biological samples since the first publications in 1979. Recent developments in sensitive fluorescent labels, with truly quantifiable linear ranges and greater limits of detection, have allowed biologists to probe tissue specific pathways and processes with higher resolution than ever before. However, the application of quantitative Western blotting (QWB) to a range of healthy tissues and those from degenerative models has highlighted a problem with significant consequences for quantitative protein analysis: how can researchers conduct comparative expression analyses when many of the commonly used reference proteins (e.g. loading controls) are differentially expressed? Here we demonstrate that common controls, including actin and tubulin, are differentially expressed in tissues from a wide range of animal models of neurodegeneration. We highlight the prevalence of such alterations through examination of published "-omics" data, and demonstrate similar responses in sensitive QWB experiments. For example, QWB analysis of spinal cord from a murine model of Spinal Muscular Atrophy using an Odyssey scanner revealed that beta-actin expression was decreased by 19.3±2% compared to healthy littermate controls. Thus, normalising QWB data to β-actin in these circumstances could result in 'skewing' of all data by ∼20%. We further demonstrate that differential expression of commonly used loading controls was not restricted to the nervous system, but was also detectable across multiple tissues, including bone, fat and internal organs. Moreover, expression of these "control" proteins was not consistent between different portions of the same tissue, highlighting the importance of careful and consistent tissue sampling for QWB experiments. Finally, having illustrated the problem of selecting appropriate single protein loading controls, we demonstrate that normalisation using total protein analysis on samples run in parallel with stains such as Coomassie blue provides a more robust approach.

[Application of laboratory information system in the management of the key indicators of quality inspection].

PubMed

Guo, Ye; Chen, Qian; Wu, Wei; Cui, Wei

2015-03-31

To establish a system of monitoring the key indicator of quality for inspection (KIQI) on a laboratory information system (LIS), and to have a better management of KIQI. Clinical sample made in PUMCH were collected during the whole of 2014. Next, interactive input program were designed to accomplish data collecting of the disqualification rate of samples, the mistake rate of samples and the occasions of losing samples, etc. Then, a series moment of sample collection, laboratory sample arrived, sample test, sample check, response to critical value, namely, trajectory information left on LIS were recorded and the qualification rate of TAT, the notification rate of endangering result were calculated. Finally, the information about quality control were collected to build an internal quality control database and the KIQI, such as the out-of-control rate of quality control and the total error of test items were monitored. The inspection of the sample management shows the disqualification rates in 2014 were all below the target, but the rates in January and February were a little high and the rates of four wards were above 2%. The mistake rates of samples was 0.47 cases/10 000 cases, attaining the target (< 2 cases/10 000 cases). Also, there was no occasion of losing samples in 2014, attaining the target too. The inspection of laboratory reports shows the qualification rates of TAT was within the acceptable range (> 95%), however the rates of blood routine in November (94.75%) was out of range. We have solved the problem by optimizing the processes. The notification rate of endangering result attained the target (≥ 98%), while the rate of timely notification is needed to improve. Quality inspection shows the CV of APTT in August (5.02%) was rising significantly, beyond the accepted CV (5.0%). We have solved the problem by changing the reagent. The CV of TT in 2014 were all below the allowable CV, thus the allowable CV of the next year lower to 10%. It is an objective and effective method to manage KIQI with the powerful management mode of database and information process capability on LIS.

Chemiluminescence measurements on irradiated garlic powder by the single photon counting technique

NASA Astrophysics Data System (ADS)

Narvaiz, P.

1995-02-01

The feasibility of identifying irradiated garlic powder measuring chemiluminescence by liquid scintillation spectrometry was studied. Samples packed in 100 μm thick polyethylene bags were irradiated in a 60Co semi-industrial facility, with doses of 10 and 30 kGy. Control and irradiated samples were stored at 20 ± 4°C and 70 ± 10% RH in darkness for 2 years. Assays were performed to establish the best sample concentration and pH of the buffer solution in which garlic powder was to be suspended for its measurement. The water content of garlic samples was also analyzed throughout storage time, as it related to the stability of the species causing luminescence. Chemiluminescence values diminished in every sample over storage time following an exponential pattern. Irradiated samples showed values significantly higher than those of the control samples, according to the radiation dose, throughout the storage period. This does not necessarily imply that the identification of the irradiated samples would be certain, since values of control samples coming from different origins have been found to fluctuate within a rather wide range. Nonetheless, in principle, the method looks promising for the measurement of chemiluminescence in irradiated samples

Evaluating and understanding fish health risks and their consequences in propagated and free-ranging fish populations

USGS Publications Warehouse

Moffitt, C.M.; Haukenes, A.H.; Williams, C.J.

2005-01-01

Fishery managers and resource conservationists are increasingly interested in understanding the fish health and disease risks of free-ranging fishes and whether propagated fishes or features and practices used at fish culture facilities pose a health risk to free-ranging populations. Disease agents are present in most both captive and all free-ranging fish populations, but the consequences and extent of infections in free-ranging populations are often difficult to measure, control, and understand. Sampling methods, protocols, and assay techniques developed to assess the health of captive populations are not as applicable for assessments of free-ranging fishes. The use of chemicals and therapeutics to control diseases and parasites in propagated fishes likely reduces the risk of introducing specific pathogens into the environment, but control measures may have localized effects on the environment surrounding fish culture facilities. To understand health risks of propagated and free ranging fishes, we must consider fish populations, culture facilities, fish releases, and their interactions within the greater geospatial features of the aquatic environment. ?? 2004 by the American Fisheries Society.

Cryogenic Liquid Sample Acquisition System for Remote Space Applications

NASA Technical Reports Server (NTRS)

Mahaffy, Paul; Trainer, Melissa; Wegel, Don; Hawk, Douglas; Melek, Tony; Johnson, Christopher; Amato, Michael; Galloway, John

2013-01-01

There is a need to acquire autonomously cryogenic hydrocarbon liquid sample from remote planetary locations such as the lakes of Titan for instruments such as mass spectrometers. There are several problems that had to be solved relative to collecting the right amount of cryogenic liquid sample into a warmer spacecraft, such as not allowing the sample to boil off or fractionate too early; controlling the intermediate and final pressures within carefully designed volumes; designing for various particulates and viscosities; designing to thermal, mass, and power-limited spacecraft interfaces; and reducing risk. Prior art inlets for similar instruments in spaceflight were designed primarily for atmospheric gas sampling and are not useful for this front-end application. These cryogenic liquid sample acquisition system designs for remote space applications allow for remote, autonomous, controlled sample collections of a range of challenging cryogenic sample types. The design can control the size of the sample, prevent fractionation, control pressures at various stages, and allow for various liquid sample levels. It is capable of collecting repeated samples autonomously in difficult lowtemperature conditions often found in planetary missions. It is capable of collecting samples for use by instruments from difficult sample types such as cryogenic hydrocarbon (methane, ethane, and propane) mixtures with solid particulates such as found on Titan. The design with a warm actuated valve is compatible with various spacecraft thermal and structural interfaces. The design uses controlled volumes, heaters, inlet and vent tubes, a cryogenic valve seat, inlet screens, temperature and cryogenic liquid sensors, seals, and vents to accomplish its task.

Determining timing of Alaska Range exhumation and glaciation through cosmogenic nuclide burial dating.

NASA Astrophysics Data System (ADS)

Sortor, R. N.; Goehring, B. M.; Bemis, S. P.; Ruleman, C.; Nichols, K. A.; Ward, D. J.; Frothingham, M.

2017-12-01

The Alaska Range is a transpressional orogen with modern exhumation initiating 6 Ma. The stratigraphic record of unroofing and uplift of the foreland basin is largely preserved along the northern flank of the Alaska Range in the Pliocene-Pleistocene aged Nenana Gravel, an extensive alluvial fan and braidplain deposit. Chronometric control on the Nenana Gravel is largely lacking, with the limited available age control based on a single Ar-Ar tephra date in an underlying unit and via stratigraphic inferences for the upper portions. Higher-resolution dating of the Nenana Gravel unit is imperative in order to quantify deposition rates and the timing of uplift and deformation of the foreland basin. Furthermore, a glacial unit has been found to lie unconformably on top of the unit at Suntrana Creek and may represent the initiation of glacial advances in the Alaska Range. We present a suite of 26Al/10Be cosmogenic nuclide burial ages collected from the lower, middle, and upper sections of the Nenana Gravel at Suntrana Creek, as well as the overlying glacial unit. Three samples from the lower Nenana Gravel yield an isochron burial age of 4.42+0.67/-0.13 Ma, which represents initiation of Nenana Gravel deposition and may equate to early unroofing of the Alaska Range. Two samples collected from the middle of the Nenana Gravel unit produced an average simple burial age of 2.25+/-0.45 Ma, with a single sample stratigraphically above dating to 0.99 +/-1.60. Two samples from the upper-most portion of the Nenana Gravel yielded an average simple burial age of 1.27+/-0.22 Ma, and one sample from the glacial unit overlying the Nenana Gravel was dated to 0.97+/-0.06 Ma, representing one of the earliest glacial advances in the region. In addition, the age of the glacial unit provides a minimum age for inception of foreland basin uplift and abandonment of the Nenana Gravel in this region.

Millimeter-Wave Absorption as a Quality Control Tool for M-Type Hexaferrite Nanopowders

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

McCloy, John S.; Korolev, Konstantin A.; Crum, Jarrod V.

2013-01-01

Millimeter wave (MMW) absorption measurements have been conducted on commercial samples of large (micrometer-sized) and small (nanometer-sized) particles of BaFe12O19 and SrFe12O19 using a quasi-optical MMW spectrometer and a series of backwards wave oscillators encompassing the 30-120 GHz range. Effective anisotropy of the particles calculated from the resonant absorption frequency indicates lower overall anisotropy in the nano-particles. Due to their high magnetocrystalline anisotropy, both BaFe12O19 and SrFe12O19 are expected to have spin resonances in the 45-55 GHz range. Several of the sampled BaFe12O19 powders did not have MMW absorptions, so they were further investigated by DC magnetization and x-ray diffractionmore » to assess magnetic behavior and structure. The samples with absent MMW absorption contained primarily iron oxides, suggesting that MMW absorption could be used for quality control in hexaferrite powder manufacture.« less

A Meta-Analysis of Morphological Interventions: Effects on Literacy Achievement of Children with Literacy Difficulties

ERIC Educational Resources Information Center

Goodwin, Amanda P.; Ahn, Soyeon

2010-01-01

This study synthesizes 79 standardized mean-change differences between control and treatment groups from 17 independent studies, investigating the effect of morphological interventions on literacy outcomes for students with literacy difficulties. Average total sample size ranged from 15 to 261 from a wide range of grade levels. Overall,…

The Effect of Aquatic Exercise Therapy on Muscle Strength and Joint's Range of Motion in Hemophilia Patients

PubMed Central

Kargarfard, Mehdi; Dehghadani, Mehdi; Ghias, Reza

2013-01-01

Background: This study was to evaluate the effect of a period of aquatic exercise therapy on muscle strength and joints range of motion in hemophilia patients. Methods: This was a semiexperimental, pretest, post-test study with a control group. This semi-experimental study comprised twenty men suffering moderate hemophilia were selected by convenience sampling method from patients of a referral hospital. They were randomly assigned to intervention and control groups of equal number. The hemophilia patients who were referred to Sayedo-Shohada Hospital enrolled in this study. Twenty men suffering moderate hemophilia were selected using convenience sampling method and then divided randomly into intervention and control groups (10 patients in each group). Subjects of aquatic exercise therapy group underwent activity in water in three sessions (45-60 minutes) per week for 8 weeks, while the control group was only under follow-up and during this period did not experience any effective physical activity. The patients’ muscle strength and joint range of motion were evaluated through standard laboratory tools, using an isokinetic dynamometer (Biodex, Systems III) and a standard goniometer in the beginning and at end of the study. Finally, data was analyzed using analysis of covariance (ANCOVA). Results: The strength of the muscles around the knee joint (to perform extension and flexion movements) increased significantly in the case group while the control group experienced a significant reduction of strength in left leg, but in right leg remarkable change was observed. Range of motion in all joints was improved in the case group, while the control group did not improve significantly. Conclusion: The results showed that aquatic exercise therapy can be a useful method to improve joints’ strength and range of motion in hemophilia patients in order to improve their daily functioning and quality of life. PMID:23412736

The diameter of nanotubes formed on Ti-6Al-4V alloy controls the adhesion and differentiation of Saos-2 cells

PubMed Central

Filova, Elena; Fojt, Jaroslav; Kryslova, Marketa; Moravec, Hynek; Joska, Ludek; Bacakova, Lucie

2015-01-01

Ti-6Al-4V-based nanotubes were prepared on a Ti-6Al-4V surface by anodic oxidation on 10 V, 20 V, and 30 V samples. The 10 V, 20 V, and 30 V samples and a control smooth Ti-6Al-4V sample were evaluated in terms of their chemical composition, diameter distribution, and cellular response. The surfaces of the 10 V, 20 V, and 30 V samples consisted of nanotubes of a relatively wide range of diameters that increased with the voltage. Saos-2 cells had a similar initial adhesion on all nanotube samples to the control Ti-6Al-4V sample, but it was lower than on glass. On day 3, the highest concentrations of both vinculin and talin measured by enzyme-linked immunosorbent assay and intensity of immunofluorescence staining were on 30 V nanotubes. On the other hand, the highest concentrations of ALP, type I collagen, and osteopontin were found on 10 V and 20 V samples. The final cellular densities on 10 V, 20 V, and 30 V samples were higher than on glass. Therefore, the controlled anodization of Ti-6Al-4V seems to be a useful tool for preparing nanostructured materials with desirable biological properties. PMID:26648719

The Quality of Water and Bottom Material in Lunga Reservoir, Virginia, September 2004 through August 2005

USGS Publications Warehouse

Lotspeich, R. Russell

2007-01-01

Lunga Reservoir is on the U.S. Marine Corps Base in Quantico, which is in the Potomac River basin and the Piedmont Physiographic Province of northern Virginia. Because of the potential use of the reservoir for scuba-diver training and public water supply in addition to current recreational activities, the U.S. Marine Corps wanted to know more about the water quality of Lunga Reservoir and how it compared to Virginia Department of Environmental Quality and Virginia State Water Control Board ambient water-quality standards. Water samples and physical properties were collected by the U.S. Geological Survey at 6 locations throughout Lunga Reservoir, and physical properties were collected at 11 additional locations in the reservoir from September 2004 through August 2005. Water samples for analysis of pesticides and bottom-material trace elements were collected once during the study at four of the sampling locations. Water temperature, dissolved-oxygen concentration, specific conductance, pH, and total chlorophyll concentration in Lunga Reservoir all had similar seasonal and spatial variations as in other lakes and reservoirs in this geographic region - thermal gradient in the summer and fall and isothermal conditions in the winter and early spring. Concentrations of water-quality indicators in Lunga Reservoir were within comparable levels of those in other reservoirs and did not violate the Virginia State Water Control Board standards for public water supplies. Water temperatures throughout Lunga Reservoir during the study period ranged from 4.4 to 30.1 degrees Celsius, well below the State Water Control Board maximum water temperature criteria of 32 degrees Celsius. Dissolved-oxygen concentrations ranged from 0.05 to 14.1 milligrams per liter throughout the reservoir during the study period, but never fell below the State Water Control Board minimum dissolved-oxygen criterion of 4.0 milligrams per liter at the surface of Lunga Reservoir. Specific conductance throughout Lunga Reservoir ranged from 29 to 173 microsiemens per centimeter at 25 degrees Celsius during the study period, with a mean specific conductance of 68 microsiemens per centimeter at 25 degrees Celsius. Measurements of pH throughout the reservoir ranged from 4.8 to 7.6 standard units. Concentrations of chemical constituents analyzed in Lunga Reservoir samples were below any State Water Control Board criteria and generally were similar in concentration to the same chemical constituents in other reservoirs in the State. Four water samples were analyzed for 54 pesticides, and none of these pesticides were above the laboratory minimum reporting level.

Calorimetric system and method

DOEpatents

Gschneidner, Jr., Karl A.; Pecharsky, Vitalij K.; Moorman, Jack O.

1998-09-15

Apparatus for measuring heat capacity of a sample where a series of measurements are taken in succession comprises a sample holder in which a sample to be measured is disposed, a temperature sensor and sample heater for providing a heat pulse thermally connected to the sample, and an adiabatic heat shield in which the sample holder is positioned and including an electrical heater. An electrical power supply device provides an electrical power output to the sample heater to generate a heat pulse. The electrical power from a power source to the heat shield heater is adjusted by a control device, if necessary, from one measurement to the next in response to a sample temperature-versus-time change determined before and after a previous heat pulse to provide a subsequent sample temperature-versus-time change that is substantially linear before and after the subsequent heat pulse. A temperature sensor is used and operable over a range of temperatures ranging from approximately 3K to 350K depending upon the refrigerant used. The sample optionally can be subjected to dc magnetic fields such as from 0 to 12 Tesla (0 to 120 kOe).

[Automatic adjustment control system for DC glow discharge plasma source].

PubMed

Wan, Zhen-zhen; Wang, Yong-qing; Li, Xiao-jia; Wang, Hai-zhou; Shi, Ning

2011-03-01

There are three important parameters in the DC glow discharge process, the discharge current, discharge voltage and argon pressure in discharge source. These parameters influence each other during glow discharge process. This paper presents an automatic control system for DC glow discharge plasma source. This system collects and controls discharge voltage automatically by adjusting discharge source pressure while the discharge current is constant in the glow discharge process. The design concept, circuit principle and control program of this automatic control system are described. The accuracy is improved by this automatic control system with the method of reducing the complex operations and manual control errors. This system enhances the control accuracy of glow discharge voltage, and reduces the time to reach discharge voltage stability. The glow discharge voltage stability test results with automatic control system are provided as well, the accuracy with automatic control system is better than 1% FS which is improved from 4% FS by manual control. Time to reach discharge voltage stability has been shortened to within 30 s by automatic control from more than 90 s by manual control. Standard samples like middle-low alloy steel and tin bronze have been tested by this automatic control system. The concentration analysis precision has been significantly improved. The RSDs of all the test result are better than 3.5%. In middle-low alloy steel standard sample, the RSD range of concentration test result of Ti, Co and Mn elements is reduced from 3.0%-4.3% by manual control to 1.7%-2.4% by automatic control, and that for S and Mo is also reduced from 5.2%-5.9% to 3.3%-3.5%. In tin bronze standard sample, the RSD range of Sn, Zn and Al elements is reduced from 2.6%-4.4% to 1.0%-2.4%, and that for Si, Ni and Fe is reduced from 6.6%-13.9% to 2.6%-3.5%. The test data is also shown in this paper.

Hypertension among older adults in low- and middle-income countries: prevalence, awareness and control.

PubMed

Lloyd-Sherlock, Peter; Beard, John; Minicuci, Nadia; Ebrahim, Shah; Chatterji, Somnath

2014-02-01

This study uses data from the World Health Organization's Study on Global Ageing and Adult Health (SAGE) to examine patterns of hypertension prevalence, awareness, treatment and control for people aged 50 years and over in China, Ghana, India, Mexico, the Russian Federation and South Africa. The SAGE sample comprises of 35 125 people aged 50 years and older, selected randomly. Hypertension was defined as ≥140 mmHg (systolic blood pressure) or ≥90 mmHg (diastolic blood pressure) or by currently taking antihypertensives. Control of hypertension was defined as blood pressure below 140/90 mmHg on treatment. A person was defined as aware if he/she was hypertensive and self-reported the condition. Prevalence rates in all countries are broadly comparable to those of developed countries (52.9%; range 32.3% in India to 77.9% in South Africa). Hypertension was associated with overweight/obesity and was more common in women, those in the lowest wealth quintile and in heavy alcohol consumers. Awareness was found to be low for all countries, albeit with substantial national variations (48.3%; range 23.3% in Ghana to 72.1% in the Russian Federation). This was also the case for control (10.2%; range 4.1% in Ghana to 14.1% India) and treatment efficacy (26.3%; range 17.4% in the Russian Federation to 55.2% in India). Awareness was associated with increasing age, being female and being overweight or obese. Effective control of hypertension was more likely in older people, women and in the richest quintile. Obesity was associated with poorer control. The high rates of hypertension in low- and middle-income countries are striking. Levels of treatment and control are inadequate despite half those sampled being aware of their condition. Since cardiovascular disease is by far the largest cause of years of life lost in these settings, these findings emphasize the need for new approaches towards control of this major risk factor.

Short range, ultra-wideband radar with high resolution swept range gate

DOEpatents

McEwan, T.E.

1998-05-26

A radar range finder and hidden object locator is based on ultra-wide band radar with a high resolution swept range gate. The device generates an equivalent time amplitude scan with a typical range of 4 inches to 20 feet, and an analog range resolution as limited by a jitter of on the order of 0.01 inches. A differential sampling receiver is employed to effectively eliminate ringing and other aberrations induced in the receiver by the near proximity of the transmit antenna, so a background subtraction is not needed, simplifying the circuitry while improving performance. Uses of the invention include a replacement of ultrasound devices for fluid level sensing, automotive radar, such as cruise control and parking assistance, hidden object location, such as stud and rebar finding. Also, this technology can be used when positioned over a highway lane to collect vehicle count and speed data for traffic control. 14 figs.

Short range, ultra-wideband radar with high resolution swept range gate

DOEpatents

McEwan, Thomas E.

1998-05-26

A radar range finder and hidden object locator is based on ultra-wide band radar with a high resolution swept range gate. The device generates an equivalent time amplitude scan with a typical range of 4 inches to 20 feet, and an analog range resolution as limited by a jitter of on the order of 0.01 inches. A differential sampling receiver is employed to effectively eliminate ringing and other aberrations induced in the receiver by the near proximity of the transmit antenna, so a background subtraction is not needed, simplifying the circuitry while improving performance. Uses of the invention include a replacement of ultrasound devices for fluid level sensing, automotive radar, such as cruise control and parking assistance, hidden object location, such as stud and rebar finding. Also, this technology can be used when positioned over a highway lane to collect vehicle count and speed data for traffic control.

Attenuation of copper in runoff from copper roofing materials by two stormwater control measures.

PubMed

LaBarre, William J; Ownby, David R; Lev, Steven M; Rader, Kevin J; Casey, Ryan E

2016-01-01

Concerns have been raised over diffuse and non-point sources of metals including releases from copper (Cu) roofs during storm events. A picnic shelter with a partitioned Cu roof was constructed with two types of stormwater control measures (SCMs), bioretention planter boxes and biofiltration swales, to evaluate the ability of the SCMs to attenuate Cu in stormwater runoff from the roof. Cu was measured as it entered the SCMs from the roof as influent as well as after it left the SCMs as effluent. Samples from twenty-six storms were collected with flow-weighted composite sampling. Samples from seven storms were collected with discrete sampling. Total Cu in composite samples of the influent waters ranged from 306 to 2863 μg L(-1) and had a median concentration of 1087 μg L(-1). Total Cu in the effluent from the planter boxes ranged from 28 to 141 μg L(-1), with a median of 66 μg L(-1). Total Cu in effluent from the swales ranged from 7 to 51 μg L(-1) with a median of 28 μg L(-1). Attenuation in the planter boxes ranged from 85 to 99% with a median of 94% by concentration and in the swales ranged from 93 to 99% with a median of 99%. As the roof aged, discrete storm events showed a pronounced first-flush effect of Cu in SCM influent but this was less pronounced in the planter outlets. Stormwater retention time in the media varied with antecedent conditions, stormwater intensity and volume with median values from 6.6 to 73.5 min. Based on local conditions, a previously-published Cu weathering model gave a predicted Cu runoff rate of 2.02 g m(-2) yr(-1). The measured rate based on stormwater sampling was 2.16 g m(-2) yr(-1). Overall, both SCMs were highly successful at retaining and preventing offsite transport of Cu from Cu roof runoff. Copyright © 2015 Elsevier Ltd. All rights reserved.

Geochemical Influence on Microbial Communities at CO2-Leakage Analog Sites.

PubMed

Ham, Baknoon; Choi, Byoung-Young; Chae, Gi-Tak; Kirk, Matthew F; Kwon, Man Jae

2017-01-01

Microorganisms influence the chemical and physical properties of subsurface environments and thus represent an important control on the fate and environmental impact of CO 2 that leaks into aquifers from deep storage reservoirs. How leakage will influence microbial populations over long time scales is largely unknown. This study uses natural analog sites to investigate the long-term impact of CO 2 leakage from underground storage sites on subsurface biogeochemistry. We considered two sites with elevated CO 2 levels (sample groups I and II) and one control site with low CO 2 content (group III). Samples from sites with elevated CO 2 had pH ranging from 6.2 to 4.5 and samples from the low-CO 2 control group had pH ranging from 7.3 to 6.2. Solute concentrations were relatively low for samples from the control group and group I but high for samples from group II, reflecting varying degrees of water-rock interaction. Microbial communities were analyzed through clone library and MiSeq sequencing. Each 16S rRNA analysis identified various bacteria, methane-producing archaea, and ammonia-oxidizing archaea. Both bacterial and archaeal diversities were low in groundwater with high CO 2 content and community compositions between the groups were also clearly different. In group II samples, sequences classified in groups capable of methanogenesis, metal reduction, and nitrate reduction had higher relative abundance in samples with relative high methane, iron, and manganese concentrations and low nitrate levels. Sequences close to Comamonadaceae were abundant in group I, while the taxa related to methanogens, Nitrospirae , and Anaerolineaceae were predominant in group II. Our findings provide insight into subsurface biogeochemical reactions that influence the carbon budget of the system including carbon fixation, carbon trapping, and CO 2 conversion to methane. The results also suggest that monitoring groundwater microbial community can be a potential tool for tracking CO 2 leakage from geologic storage sites.

Geochemical Influence on Microbial Communities at CO2-Leakage Analog Sites

PubMed Central

Ham, Baknoon; Choi, Byoung-Young; Chae, Gi-Tak; Kirk, Matthew F.; Kwon, Man Jae

2017-01-01

Microorganisms influence the chemical and physical properties of subsurface environments and thus represent an important control on the fate and environmental impact of CO2 that leaks into aquifers from deep storage reservoirs. How leakage will influence microbial populations over long time scales is largely unknown. This study uses natural analog sites to investigate the long-term impact of CO2 leakage from underground storage sites on subsurface biogeochemistry. We considered two sites with elevated CO2 levels (sample groups I and II) and one control site with low CO2 content (group III). Samples from sites with elevated CO2 had pH ranging from 6.2 to 4.5 and samples from the low-CO2 control group had pH ranging from 7.3 to 6.2. Solute concentrations were relatively low for samples from the control group and group I but high for samples from group II, reflecting varying degrees of water-rock interaction. Microbial communities were analyzed through clone library and MiSeq sequencing. Each 16S rRNA analysis identified various bacteria, methane-producing archaea, and ammonia-oxidizing archaea. Both bacterial and archaeal diversities were low in groundwater with high CO2 content and community compositions between the groups were also clearly different. In group II samples, sequences classified in groups capable of methanogenesis, metal reduction, and nitrate reduction had higher relative abundance in samples with relative high methane, iron, and manganese concentrations and low nitrate levels. Sequences close to Comamonadaceae were abundant in group I, while the taxa related to methanogens, Nitrospirae, and Anaerolineaceae were predominant in group II. Our findings provide insight into subsurface biogeochemical reactions that influence the carbon budget of the system including carbon fixation, carbon trapping, and CO2 conversion to methane. The results also suggest that monitoring groundwater microbial community can be a potential tool for tracking CO2 leakage from geologic storage sites. PMID:29170659

Efficient design of cluster randomized trials with treatment-dependent costs and treatment-dependent unknown variances.

PubMed

van Breukelen, Gerard J P; Candel, Math J J M

2018-06-10

Cluster randomized trials evaluate the effect of a treatment on persons nested within clusters, where treatment is randomly assigned to clusters. Current equations for the optimal sample size at the cluster and person level assume that the outcome variances and/or the study costs are known and homogeneous between treatment arms. This paper presents efficient yet robust designs for cluster randomized trials with treatment-dependent costs and treatment-dependent unknown variances, and compares these with 2 practical designs. First, the maximin design (MMD) is derived, which maximizes the minimum efficiency (minimizes the maximum sampling variance) of the treatment effect estimator over a range of treatment-to-control variance ratios. The MMD is then compared with the optimal design for homogeneous variances and costs (balanced design), and with that for homogeneous variances and treatment-dependent costs (cost-considered design). The results show that the balanced design is the MMD if the treatment-to control cost ratio is the same at both design levels (cluster, person) and within the range for the treatment-to-control variance ratio. It still is highly efficient and better than the cost-considered design if the cost ratio is within the range for the squared variance ratio. Outside that range, the cost-considered design is better and highly efficient, but it is not the MMD. An example shows sample size calculation for the MMD, and the computer code (SPSS and R) is provided as supplementary material. The MMD is recommended for trial planning if the study costs are treatment-dependent and homogeneity of variances cannot be assumed. © 2018 The Authors. Statistics in Medicine published by John Wiley & Sons Ltd.

Characterization of Noise Signatures of Involuntary Head Motion in the Autism Brain Imaging Data Exchange Repository

PubMed Central

Caballero, Carla; Mistry, Sejal; Vero, Joe; Torres, Elizabeth B

2018-01-01

The variability inherently present in biophysical data is partly contributed by disparate sampling resolutions across instrumentations. This poses a potential problem for statistical inference using pooled data in open access repositories. Such repositories combine data collected from multiple research sites using variable sampling resolutions. One example is the Autism Brain Imaging Data Exchange repository containing thousands of imaging and demographic records from participants in the spectrum of autism and age-matched neurotypical controls. Further, statistical analyses of groups from different diagnoses and demographics may be challenging, owing to the disparate number of participants across different clinical subgroups. In this paper, we examine the noise signatures of head motion data extracted from resting state fMRI data harnessed under different sampling resolutions. We characterize the quality of the noise in the variability of the raw linear and angular speeds for different clinical phenotypes in relation to age-matched controls. Further, we use bootstrapping methods to ensure compatible group sizes for statistical comparison and report the ranges of physical involuntary head excursions of these groups. We conclude that different sampling rates do affect the quality of noise in the variability of head motion data and, consequently, the type of random process appropriate to characterize the time series data. Further, given a qualitative range of noise, from pink to brown noise, it is possible to characterize different clinical subtypes and distinguish them in relation to ranges of neurotypical controls. These results may be of relevance to the pre-processing stages of the pipeline of analyses of resting state fMRI data, whereby head motion enters the criteria to clean imaging data from motion artifacts. PMID:29556179

Progression of abnormal MIB-1 staining patterns of reserve cells in cervical smears from women ultimately developing high grade squamous intraepithelial lesions.

PubMed

Siemens, Frederike C; van Haaften, Carolien; Kuijpers, Johan C; Helmerhorst, Theo J M; Boon, Mathilde E

2006-01-01

To assess, in a longitudinal study in women diagnosed with high grade squamous epithelial lesion (HSIL), the progression over time of proliferative activity in reserve cells using population screening cervical cytology specimens. Twenty consecutive, unselected patients with HSIL lesions were part of the national cervical screening program. From the archives, for each patient, the last prior normal population screening smear was included in the study. Concurrent sets of cervical smears from 80 age-matched women without pathology formed the controls. The original slides were stained using MIB-1 monoclonal antibody. The fraction of MIB-1-positive reserve cells was assessed using systematic random sampling and running progressive means assessment to ensure a sufficient sample size. The proliferation fraction in reserve cells of HSIL patients was significantly raised (mean, 65.0%; range, 53.5-94.1%; p < 0.01) as compared with that in concurrent controls (mean, 12.8%; range, 1.9-45.4%). Prior smears from HSIL patients, although without morphologic abnormalities, had abnormally high proliferation fractions (mean, 59.1%; range, 1.0-94.7%), significantly raised over those from concurrent controls (mean, 9.4%; range In population-based cervical smear screening, HSIL patients already have abnormally raised proliferation fractions of reserve cells, even without morphologic changes in squamous cells, 1-5 (mean, 3.6) years prior to diagnosis.

Myocardial concentrations of fatty acids in dogs with dilated cardiomyopathy.

PubMed

Smith, Caren E; Freeman, Lisa M; Meydani, Mohsen; Rush, John E

2005-09-01

To compare myocardial concentrations of fatty acids in dogs with dilated cardiomyopathy (DCM) with concentrations in control dogs. Myocardial tissues from 7 dogs with DCM and 16 control dogs. Myocardial tissues were homogenized, and total fatty acids were extracted and converted to methyl esters. Myocardial concentrations of fatty acids were analyzed by use of gas chromatography and reported as corrected percentages. The amount of docosatetraenoic acid (C22:4 n-6) was significantly higher in myocardial samples from dogs with DCM (range, 0.223% to 0.774%; median, 0.451%), compared with the amount in samples obtained from control dogs (range, 0.166% to 0.621%; median, 0.280%). There were no significant differences between DCM and control dogs for concentrations of any other myocardial fatty acids. Although concentrations of most myocardial fatty acids did not differ significantly between dogs with DCM and control dogs, the concentration of docosatetraenoic acid was significantly higher in dogs with DCM. Additional investigation in a larger population is warranted to determine whether this is a primary or secondary effect of the underlying disease and whether alterations in fatty acids may be a target for intervention in dogs with DCM.

Fully automated, internally controlled quantification of hepatitis B Virus DNA by real-time PCR by use of the MagNA Pure LC and LightCycler instruments.

PubMed

Leb, Victoria; Stöcher, Markus; Valentine-Thon, Elizabeth; Hölzl, Gabriele; Kessler, Harald; Stekel, Herbert; Berg, Jörg

2004-02-01

We report on the development of a fully automated real-time PCR assay for the quantitative detection of hepatitis B virus (HBV) DNA in plasma with EDTA (EDTA plasma). The MagNA Pure LC instrument was used for automated DNA purification and automated preparation of PCR mixtures. Real-time PCR was performed on the LightCycler instrument. An internal amplification control was devised as a PCR competitor and was introduced into the assay at the stage of DNA purification to permit monitoring for sample adequacy. The detection limit of the assay was found to be 200 HBV DNA copies/ml, with a linear dynamic range of 8 orders of magnitude. When samples from the European Union Quality Control Concerted Action HBV Proficiency Panel 1999 were examined, the results were found to be in acceptable agreement with the HBV DNA concentrations of the panel members. In a clinical laboratory evaluation of 123 EDTA plasma samples, a significant correlation was found with the results obtained by the Roche HBV Monitor test on the Cobas Amplicor analyzer within the dynamic range of that system. In conclusion, the newly developed assay has a markedly reduced hands-on time, permits monitoring for sample adequacy, and is suitable for the quantitative detection of HBV DNA in plasma in a routine clinical laboratory.

Assessment of arsenic surface contamination in a museum anthropology department.

PubMed

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

2013-02-01

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

Hazardous impact and translocation of vanadium (V) species from soil to different vegetables and grasses grown in the vicinity of thermal power plant.

PubMed

Khan, Sumaira; Kazi, Tasneem Gul; Kolachi, Nida Fatima; Baig, Jameel Ahmed; Afridi, Hassan Imran; Shah, Abdul Qadir; Kumar, Sham; Shah, Faheem

2011-06-15

The distribution of vanadium (V) species in soil (test soil), vegetables and grasses, collected from the vicinity of a thermal power plant has been studied. For comparison purpose soil (control soil), same vegetable and grass samples were collected from agricultural land devoid of any industrial area. A simple and efficient ultrasonic assisted extraction method has been developed for the extraction of V(5+) species from soil, vegetable and grass samples using Na(2)CO(3) in the range of 0.1-0.5 mol/L. For comparison purpose same sub samples were also extracted by conventional heating method. The total and V species were determined by electrothermal atomic absorption spectrometry using different modifiers. The validity of V(5+) and V(4+) determination had been confirmed by the spike recovery and total amount of V by the analysis of CRM 1570 (spinach leave) and sub samples of agricultural soil. The concentration of total V was found in the range of 90-215 and 11.4-42.3 μg/g in test and control soil samples, respectively. The contents of V(5+) and total V in vegetables and grasses grown around the thermal power plant were found in the range of 2.9-5.25 and 8.74-14.9 μg/g, respectively, which were significantly higher than those values obtained from vegetables and fodders grown in non exposed agricultural site (P<0.01). Statistical evaluations indicate that the sum of concentrations of V(5+) and V(4+) species was not significantly different from total concentration of V in same sub samples of vegetable, grass and soil of both origins, at 95% level of confidence. Copyright © 2011 Elsevier B.V. All rights reserved.

Development and validation of a UPLC-MS/MS method for the simultaneous determination of paritaprevir and ritonavir in rat liver.

PubMed

Ocque, Andrew J; Hagler, Colleen E; Difrancesco, Robin; Woolwine-Cunningham, Yvonne; Bednasz, Cindy J; Morse, Gene D; Talal, Andrew H

2016-07-01

Determination of paritaprevir and ritonavir in rat liver tissue samples. We successfully validated a UPLC-MS/MS method to measure paritaprevir and ritonavir in rat liver using deuterated internal standards (d8-paritapervir and d6-ritonavir). The method is linear from 20 to 20,000 and 5 to 10,000 pg on column for paritaprevir and ritonavir, respectively, and is normalized per milligram tissue. Interday and intraday variability ranged from 0.591 to 5.33% and accuracy ranged from -6.68 to 10.1% for quality control samples. The method was then applied to the measurement of paritaprevir and ritonavir in rat liver tissue samples from a pilot study. The validated method is suitable for measurement of paritaprevir and ritonavir within rat liver tissue samples for PK studies.

Anesthesia and blood sampling of wild big brown bats (Eptesicus fuscus) with an assessment of impacts on survival

USGS Publications Warehouse

Wimsatt, J.; O'Shea, T.J.; Ellison, L.E.; Pearce, R.D.; Price, V.R.

2005-01-01

We anesthetized and blood sampled wild big brown bats (Eptesicus fuscus) in Fort Collins, Colorado (USA) in 2001 and 2002 and assessed effects on survival. Inhalant anesthesia was delivered into a specially designed restraint and inhalation capsule that minimized handling and bite exposures. Bats were immobilized an average of 9.1±5.1 (SD) min (range 1–71, n=876); blood sample volumes averaged 58±12 μl (range 13–126, n=718). We randomly selected control (subject to multiple procedures before release) and treatment (control procedures plus inhalant anesthesia and 1% of body weight blood sampling) groups in 2002 to assess treatment effects on daily survival over a 14-day period for adult female and volant juvenile bats captured at maternity roosts in buildings. We monitored survival after release using passive integrated transponder tag detection hoops placed at openings to selected roosts. Annual return rates of bats sampled in 2001 were used to assess long-term outcomes. Comparison of 14-day maximum-likelihood daily survival estimates from control (86 adult females, 92 volant juveniles) and treated bats (187 adult females, 87 volant juveniles) indicated no adverse effect from anesthesia and blood sampling (juveniles: χ2=22.22, df=27, P>0.05; adults: χ2=9.72, df=18, P>0.05). One-year return rates were similar among adult female controls (81%, n=72, 95% confidence interval [CI] =70–91%), females treated once (82%, n=276, 95% CI=81–84%), and females treated twice (84%, n=50, 95% CI=74–94%). Lack of an effect was also noted in 1-yr return rates of juvenile female controls (55%, n=29, 95% CI=37–73%), juveniles treated once (66%, n=113, 95% CI=58–75%), and juveniles treated twice (71%, n=17, 95% CI=49–92%). These data suggest that anesthesia and blood sampling for health monitoring did not measurably affect survival of adult female and volant juvenile big brown bats.

The effect of viroid infection of citrus trees on the amoebicidal activity of 'Maltese half-blood' (Citrus sinensis) against trophozoite stage of Acanthamoeba castellanii Neff.

PubMed

Zouaghi, Ghaya; Najar, Asma; Chiboub, Olfa; Sifaoui, Ines; Abderrabba, Manef; Lorenzo Morales, Jacob

2017-12-01

In order to promote a local Tunisian product, this study was designed to examine, for the first time, the anti-Acanthamoeba activity (Acanthamoeba castellanii Neff) of the essential oils of Tunisian Citrus sinensis peels (Maltese half-blood) and the effect of viroid plant infection on this activity. To do so, three samples of peels' essential oils were studied: from a healthy plant (Control), a plant inoculated with Citrus exocortis viroid (CEVd) and one inoculated with hot stunt cachexia viroid (HSVd). The samples were extracted by hydrodistillation from dried peels and characterized by GC-MS. Limonene was the major component with a percentage ranging from 90.76 to 93.34% for (CEVd) sample and (Control), respectively. Anti-Acanthamoeba activity of the tested oils was determined by the Alamar Blue ® assay. Primary results showed a strong potential anti-Acanthamoeba activity with an IC 50 ranging from 36.6 to 54.58 μg/ml for (HSVd) and (CEVd) samples, respectively. In terms of the effect of viroid infection, a strong positive correlation was observed between different chemical classes and anti-Acanthamoeba activity. Copyright © 2017 Elsevier Inc. All rights reserved.

Quantitation of tamsulosin in human plasma by liquid chromatography-electrospray ionization mass spectrometry.

PubMed

Din, Li; Li, Limin; Tao, Ping; Yang, Jin; Zhang, Zhengxing

2002-02-05

A highly sensitive method for quantitation of tamsulosin in human plasma using 1-(2,6-dimethyl-3-hydroxylphenoxy)-2-(3,4-methoxyphenylethylamino)-propane hydrochloride as the internal standard (I.S.) was established using liquid chromatography-electrospray ionization-mass spectrometry (LC-ESI-MS). After alkalization with saturated sodium bicarbonate, plasma were extracted by ethyl acetate and separated by HPLC on a C18 reversed-phase column using a mobile phase of methanol-water-acetic acid-triethylamine (620:380:1.5:1.5, v/v). Analytes were quantitated using positive electrospray ionization in a quadrupole spectrometer. LC-ESI-MS was performed in the selected ion monitoring (SIM) mode using target ions at m/z 228 for tamsulosin and m/z 222 for the I.S. Calibration curves, which were linear over the range 0.2-30 ng/ml, were analyzed contemporaneously with each batch of samples, along with low (0.5 ng/ml), medium (3 ng/ml) and high (30 ng/ml) quality control samples. The intra- and inter-assay variability ranged from 2.14 to 8.87% for the low, medium and high quality control samples. The extraction recovery of tamsulosin from plasma was in the range of 84.2-94.5%. The method has been used successfully to study tamsulosin pharmacokinetics in adult humans.

Next-generation sequencing and clinical outcomes of patients with lung adenocarcinoma treated with stereotactic body radiotherapy.

PubMed

Cassidy, Richard J; Zhang, Xinyan; Patel, Pretesh R; Shelton, Joseph W; Escott, Chase E; Sica, Gabriel L; Rossi, Michael R; Hill, Charles E; Steuer, Conor E; Pillai, Rathi N; Ramalingam, Suresh S; Owonikoko, Taofeek K; Behera, Madhusmita; Force, Seth D; Fernandez, Felix G; Curran, Walter J; Higgins, Kristin A

2017-10-01

Genetic aberrations are well characterized in lung adenocarcinomas (LACs) and clinical outcomes have been influenced by targeted therapies in the advanced setting. Stereotactic body radiotherapy (SBRT) is the standard-of-care therapy for patients with nonoperable, early-stage LAC, but to the authors' knowledge, no information is available regarding the impact of genomic changes in these patients. The current study sought to determine the frequency and clinical impact of genetic aberrations in this population. Under an Institutional Review Board-approved protocol, the records of 242 consecutive patients with early-stage lung cancers were reviewed; inclusion criteria included LAC histology with an adequate tumor sample for the successful use of next-generation sequencing and fluorescence in situ hybridization testing. Univariate analysis was performed to identify factors associated with clinical outcomes. LAC samples from 98 of the 242 patients were reviewed (40.5%), of whom 45 patients (46.0%) had genetic testing. The following mutations were noted: KRAS in 20.0% of samples, BRAF in 2.2% of samples, SMAD family member 4 (SMAD4) in 4.4% of samples, epidermal growth factor receptor (EGFR) in 15.6% of samples, STK1 in 2.2% of samples, tumor protein 53 (TP53) in 15.6% of samples, and phosphatase and tensin homolog (PTEN) in 2.2% of samples. The following gene rearrangements were observed: anaplastic lymphoma kinase (ALK) in 8.9% of samples, RET in 2.2% of samples, and MET amplification in 17.8% of samples. The median total delivered SBRT dose was 50 grays (range, 48-60 grays) over a median of 5 fractions (range, 3-8 fractions). The KRAS mutation was associated with worse local control (odds ratio [OR], 3.64; P<.05). MET amplification was associated with worse regional (OR, 4.64; P<.05) and distant (OR, 3.73; P<.05) disease control. To the authors' knowledge, the current series is the first to quantify genetic mutations and their association with clinical outcomes in patients with early-stage LAC treated with SBRT. KRAS mutations were associated with worse local control and MET amplification was associated with worse regional and distant disease control, findings that need to be validated in a prospective setting. Cancer 2017;123:3681-3690. © 2017 American Cancer Society. © 2017 American Cancer Society.

Environmental assessment of a wood-waste-fired industrial watertube boiler. Volume 1. Technical results. Final report, March 1981-March 1984

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

Castaldini, C.; Waterland, L.R.

1987-03-01

The two-volume report gives results from field tests of a wood-waste-fired industrial watertube boiler. Two series of tests were performed: one firing dry (11% moisture) wood waste, and the other firing green (34% moisture) wood waste. Emission measurements included: continuous monitoring of flue-gas emissions; source-assessment sampling system (SASS) sampling of the flue gas with subsequent laboratory analysis of samples to give total flue-gas organics in two boiling-point ranges, compound category information within these ranges, specific quantitation of the semi-volatile organic priority pollutants, and flue-gas concentrations of 73 trace elements; Method 5 sampling for particulate; controlled condensation system sampling for SO/submore » 2/ and SO/sub 3/; and grab sampling of boiler mechanical collector hopper ash for inorganic composition determinations. Total organic emissions decreased from 60-135 mg/dscm firing dry wood to 2-65 mg/dscm firing green wood, in parallel with corresponding boiler CO emissions.« less

Environmental assessment of a wood-waste-fired industrial watertube boiler. Volume 2. Data supplement. Final report, March 1981-March 1984

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

Castaldini, C.; Waterland, L.R.

1987-03-01

The two-volume report gives results from field tests of a wood-waste-fired industrial watertube boiler. Two series of tests were performed: one firing dry (11% moisture) wood waste, and the other firing green (34% moisture) wood waste. Emission measurements included: continuous monitoring of flue-gas emissions; source-assessment sampling system (SASS) sampling of the flue-gas with subsequent laboratory analysis of samples to give total flue-gas organics in two boiling-point ranges, compound category information within these ranges, specific quantitation of the semi-volatile organic priority pollutants, and flue gas concentrations of 73 trace elements; Method 5 sampling for particulate; controlled condensation system sampling for SO/submore » 2/ and SO/sub 3/; and grab sampling of boiler mechanical collector hopper ash for inorganic and organic composition determinations. Total organic emissions decreased from 60-135 mg/dscm firing dry wood to 2-65 mg/dscm firing green wood, in parallel with corresponding boiler CO emissions.« less

Solid state electro-optic color filter and iris

NASA Technical Reports Server (NTRS)

1974-01-01

Test results obtained have confirmed the practicality of the solid state electro-optic filters as an optical control element in a television system. Neutral-density control range in excess of 1000:1 has been obtained on sample filters. Test results, measurements in a complete camera system, discussions of problem areas, analytical comparisons, and recommendations for future investigations are included.

Effect of parvoviral enteritis on plasma citrulline concentration in dogs.

PubMed

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

2011-01-01

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

Controls on surface water chemistry in the upper Merced River basin, Yosemite National Park, California

USGS Publications Warehouse

Clow, D.W.; Mast, M.A.; Campbell, D.H.

1996-01-01

Surface water draining granitic bedrock in Yosemite National Park exhibits considerable variability in chemical composition, despite the relative homogeneity of bedrock chemistry. Other geological factors, including the jointing and distribution of glacial till, appear to exert strong controls on water composition. Chemical data from three surface water surveys in the upper Merced River basin conducted in August 1981, June 1988 and August 1991 were analysed and compared with mapped geological, hydrological and topographic features to identify the solute sources and processes that control water chemistry within the basin during baseflow. Water at most of the sampling sites was dilute, with alkalinities ranging from 26 to 77 ??equiv. 1-1. Alkalinity was much higher in two subcatchments, however, ranging from 51 to 302 ??equiv. 1-1. Base cations and silica were also significantly higher in these two catchments than in the rest of the watershed. Concentrations of weathering products in surface water were correlated to the fraction of each subcatchment underlain by surficial material, which is mostly glacial till. Silicate mineral weathering is the dominant control on concentrations of alkalinity, silica and base cations, and ratios of these constituents in surface water reflect the composition of local bedrock, Chloride concentrations in surface water samples varied widely, ranging from <1 to 96 ??equiv. 1-1. The annual volume-weighted mean chloride concentration in the Merced River at the Happy Isles gauge from 1968 to 1990 was 26 ??equiv. 1-1, which was five times higher than in atmospheric deposition (4-5 ??equiv. 1-1), suggesting that a source of chloride exists within the watershed. Saline groundwater springs, whose locations are probably controlled by vertical jointing in the bedrock, are the most likely source of the chloride. Sulphate concentrations varied much less than most other solutes, ranging from 3 to 14 ??equiv. 1-1. Concentrations of sulphate in quarterly samples collected at the watershed outlet also showed relatively little variation, suggesting that sulphate may be regulated to some extent by a within-watershed process, such as sulphate adsorption.

Profile of microflora of the posterior intestine of Chinook salmon before, during, and after administration of rations with and without erythromycin

USGS Publications Warehouse

Moffitt, C.M.; Mobin, S.M.A.

2006-01-01

We describe the resident heterotrophic aerobic microflora of the salmonid posterior intestine before, during, and after the administration of rations with erythromycin in a hatchery raceway environment. We compare the profiles of medicated Chinook salmon Oncorhynchus tshawytscha with those of control fish that were not fed erythromycin. The combined counts of bacteria and yeasts per gram of fish intestine originating from four upstream raceways ranged from 3.0 ?? 102 to 9.6 ?? 105 colony-forming units (CFU) over the study period. Yeasts were commonly identified in the gut, and abundances ranged from 0% to more than 80% of the CFU. Erythromycin therapy decreased the total microbial population and altered the bacterial diversity in the gut during treatment. The intestinal microbial populations in fish medicated with erythromycin increased rapidly after treatment ceased, and by 25 d after treatment the CFU were similar in samples from both medicated and control fish populations. Of 325 isolates from fish selected for biochemical profiles, we identified a total of eight gram-positive and eight gram-negative genera. Bacillus spp. were common throughout sampling and were identified in samples of fish feed. Erythromycin-resistant, gram-positive bacteria were observed throughout the sampling in medicated and control fish. We identified seven gram-positive and two gram-negative genera in 74 selected isolates from control and erythromycin feeds. Our studies suggest that the aerobic microflora of the posterior intestine varies over time, and it is likely that few resistant genera of concern to human health are present.

Auto-calibrated scanning-angle prism-type total internal reflection microscopy for nanometer-precision axial position determination and optional variable-illumination-depth pseudo total internal reflection microscopy

DOEpatents

Fang, Ning; Sun, Wei

2015-04-21

A method, apparatus, and system for improved VA-TIRFM microscopy. The method comprises automatically controlled calibration of one or more laser sources by precise control of presentation of each laser relative a sample for small incremental changes of incident angle over a range of critical TIR angles. The calibration then allows precise scanning of the sample for any of those calibrated angles for higher and more accurate resolution, and better reconstruction of the scans for super resolution reconstruction of the sample. Optionally the system can be controlled for incident angles of the excitation laser at sub-critical angles for pseudo TIRFM. Optionally both above-critical angle and sub critical angle measurements can be accomplished with the same system.

Concentrations and human health risk assessment of DDT and its metabolites in free-range and commercial chicken products from KwaZulu-Natal, South Africa.

PubMed

Thompson, L A; Ikenaka, Y; Yohannes, Y B; van Vuren, J J; Wepener, V; Smit, N J; Darwish, W S; Nakayama, S M M; Mizukawa, H; Ishizuka, M

2017-11-01

Organochlorine pesticides such as dichlorodiphenyltrichloroethane (DDT) have been used in agriculture and for disease control purposes over many decades. Reports suggest that DDT exposure may result in a number of adverse effects in humans. In the KwaZulu-Natal Province of South Africa, DDT is sprayed annually in homes (indoor residual spraying) to control the mosquito vector of malaria. In the northern part of the Province, samples of free-range chicken meat (n = 48) and eggs (n = 13), and commercially produced chicken meat (n = 6) and eggs (n = 11), were collected and analysed. Of the free-range chicken meat samples, 94% (45/48) contained DDTs (ΣDDTs median 6.1 ng/g wet weight [ww], maximum 79.1 ng/g ww). Chicken egg contents were also contaminated (ΣDDTs in free-range eggs median 9544 ng/g ww, maximum 96.666 ng/g ww; and in commercial eggs median 1.3 ng/g ww, maximum 4.6 ng/g ww). The predominant DDT congener detected was p,p'-DDE in both free-range meat (>63%) and eggs (>66%), followed by p,p'-DDT and then p,p'-DDD. Based on estimated daily intake values, calculated human risk ratio (carcinogenic) values were >1 for DDTs detected in both free-range chicken products. Consumption of free-range eggs poses a particularly high health risk.

Evolution of critical day length for diapause induction enables range expansion of Diorhabda carinulata, a biological control agent against tamarisk (Tamarix spp.)

PubMed Central

Bean, Dan W; Dalin, Peter; Dudley, Tom L

2012-01-01

In classical weed biological control, small collections of arthropods are made from one or a few sites in the native range of the target plant and are introduced to suppress the plant where it has become invasive, often across a wide geographic range. Ecological mismatches in the new range are likely, and success using the biocontrol agent may depend on postrelease evolution of beneficial life history traits. In this study, we measure the evolution of critical day length for diapause induction (day length at which 50% of the population enters dormancy), in a beetle (Diorhabda carinulata) introduced into North America from China to control an exotic shrub, Tamarix spp. Beetle populations were sampled from four sites in North America 7 years after introduction, and critical day length was shown to have declined, forming a cline over a latitudinal gradient At one field site, decreased critical day length was correlated with 16 additional days of reproductive activity, resulting in a closer match between beetle life history and the phenology of Tamarix. These findings indicate an enhanced efficacy and an increasingly wider range for D. carinulata in Tamarix control. PMID:22949926

Innovations in Rheometer Controlled-Rate Control Loop Design: Ultra Low Angular Speed Control and New Applications

NASA Astrophysics Data System (ADS)

Schulz, Ulrich; Sierro, Philippe; Nijman, Jint

2008-07-01

The design and implementation of an angular speed control loop for a universal rheometer is not a trivial task. The combination of a highly dynamic, very low inertia (drag cup) motor (motor inertia is 10-5 kg m2) with samples which can range in viscosity from 10-3 Pas to 108 Pas, which can be between purely viscous and higly viscoelastic, which can exhibit yield-stresses, etc. asks for a highly adaptive digital control loop. For the HAAKE MARS rotational rheometer a new adaptive control loop was developed which allows the control of angular speeds as low 5×10-9 rad/s and response times a short as 10 ms. The adaptation of the control loop to "difficult" samples is performed by analysing the response of the complete system to a short pre-test. In this paper we will show that the (very) short response times at (very) low angular speeds are not only achieved with ideal samples, but due to the adaptable control loop, also with "difficult" samples. We will show measurement results on "difficult" samples like cosmetic creams and emulsions, a laponite gel, etc. to proof that angular speeds down to 10-4 rad/s are reached within 10 ms to 20 ms and angular speeds down to 10-7 rad/s within 1 s to 2 s. The response times for reaching ultra low angular speeds down to 5×10-9 rad/s are in the order of 10 s to 30 s. With this new control loop it is, for the first time, possible to measure yield stresses by applying a very low constant shear-rate to the sample and measuring the torque response as a function of time.

Segmental analysis of amphetamines in hair using a sensitive UHPLC-MS/MS method.

PubMed

Jakobsson, Gerd; Kronstrand, Robert

2014-06-01

A sensitive and robust ultra high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method was developed and validated for quantification of amphetamine, methamphetamine, 3,4-methylenedioxyamphetamine and 3,4-methylenedioxy methamphetamine in hair samples. Segmented hair (10 mg) was incubated in 2M sodium hydroxide (80°C, 10 min) before liquid-liquid extraction with isooctane followed by centrifugation and evaporation of the organic phase to dryness. The residue was reconstituted in methanol:formate buffer pH 3 (20:80). The total run time was 4 min and after optimization of UHPLC-MS/MS-parameters validation included selectivity, matrix effects, recovery, process efficiency, calibration model and range, lower limit of quantification, precision and bias. The calibration curve ranged from 0.02 to 12.5 ng/mg, and the recovery was between 62 and 83%. During validation the bias was less than ±7% and the imprecision was less than 5% for all analytes. In routine analysis, fortified control samples demonstrated an imprecision <13% and control samples made from authentic hair demonstrated an imprecision <26%. The method was applied to samples from a controlled study of amphetamine intake as well as forensic hair samples previously analyzed with an ultra high performance liquid chromatography time of flight mass spectrometry (UHPLC-TOF-MS) screening method. The proposed method was suitable for quantification of these drugs in forensic cases including violent crimes, autopsy cases, drug testing and re-granting of driving licences. This study also demonstrated that if hair samples are divided into several short segments, the time point for intake of a small dose of amphetamine can be estimated, which might be useful when drug facilitated crimes are investigated. Copyright © 2014 John Wiley & Sons, Ltd.

Effects of orbital exposure on Halar during the LDEF mission

NASA Technical Reports Server (NTRS)

Brower, William E., Jr.; Holla, Harish; Bauer, Robert A.

1992-01-01

Thermomechanical Analysis (TMA), Differential Scanning Calorimetry (DSC), and Thermogravimetric Analysis (TGA) were performed on samples of Halar exposed on the LDEF Mission for 6 years in orbit and unexposed Halar control samples. Sections 10-100 microns thick were removed from the exposed surface down to a depth of 1,000 microns through the 3 mm thick samples. The TMA and DSC results, which arise from the entire slice and not just its surface, showed no differences between the LDEF and the control samples. TMA scans were run from ambient to 300 C; results were compared by a tabulation of the glass transition temperatures. DSC scans were run from ambient to 700 C; the enthalpy of melting was compared for the samples as a function of section depth with the sample. The TGA results, which arise from the surface of the sample initially, showed a sharp increase in the topmost 50 micron section (the exposed, discolored side) in the weight loss of 170 C in oxygen. This weight loss dropped to bulk values in the range of depth of 50-200 microns. The control sample showed only a slight increase in weight loss as the top surface was approached. The LDEF Halar sample appears to be mechanically undamaged, with a surface layer which oxidizes faster as a result of orbital exposure.

Serial isoelectric focusing as an effective and economic way to obtain maximal resolution and high-throughput in 2D-based comparative proteomics of scarce samples: proof-of-principle.

PubMed

Farhoud, Murtada H; Wessels, Hans J C T; Wevers, Ron A; van Engelen, Baziel G; van den Heuvel, Lambert P; Smeitink, Jan A

2005-01-01

In 2D-based comparative proteomics of scarce samples, such as limited patient material, established methods for prefractionation and subsequent use of different narrow range IPG strips to increase overall resolution are difficult to apply. Also, a high number of samples, a prerequisite for drawing meaningful conclusions when pathological and control samples are considered, will increase the associated amount of work almost exponentially. Here, we introduce a novel, effective, and economic method designed to obtain maximum 2D resolution while maintaining the high throughput necessary to perform large-scale comparative proteomics studies. The method is based on connecting different IPG strips serially head-to-tail so that a complete line of different IPG strips with sequential pH regions can be focused in the same experiment. We show that when 3 IPG strips (covering together the pH range of 3-11) are connected head-to-tail an optimal resolution is achieved along the whole pH range. Sample consumption, time required, and associated costs are reduced by almost 70%, and the workload is reduced significantly.

Biodetection grinder

NASA Technical Reports Server (NTRS)

Beyerle, F. J.

1973-01-01

A biodetection grinder for sampling aerospace materials for microorganisms without killing them was constructed. The device employs a shearing action to generate controllable sized particles with a minimum of energy input. Tests were conducted on materials ranging from soft plastics to hard rocks.

Determination of emamectin benzoate in medicated fish feed.

PubMed

Farer, L J; Hayes, J; Rosen, J; Knight, P

1999-01-01

A method was developed to quantitate emamectin benzoate in fish feed at levels between 5 and 15 ppm. The active ingredient is extracted from 20 g medicated feed into aqueous-methanolic solvent by overnight shaking. A solid-phase extraction procedure using a 2 g C18 cartridge is then used to concentrate the active residue and remove interfering matrix components. The extracted drug and internal standard are eluted from the cartridge, evaporated to dryness, and reconstituted in methanol. A control feed sample and fortified control working standard are simultaneously prepared. Remaining interferences and sample analysis are further separated on a gradient liquid chromatographic system. Recovery of emamectin benzoate from fortified feeds ranged from 97 to 100%, with a coefficient of variation (CV) of 1.2%. Determination of emamectin benzoate in medicated feeds resulted in CVs ranging from 2.3 to 4.2% and recoveries of 88 to 98% of label claim.

The role of birds in arboviral disease surveillance in Harris County and the City of Houston, Texas.

PubMed

Wilkerson, Lauren; Reyna Nava, Martin; Battle-Freeman, Cheryl; Travassos da Rosa, Amelia; Guzman, Hilda; Tesh, Robert; Debboun, Mustapha

2017-01-01

Avian arboviral surveillance is an integral part of any disease-based integrated mosquito control program. The Harris County Public Health Mosquito and Vector Control Division has performed arboviral surveillance in the wild birds of Harris County and the City of Houston since 1965. Blood samples from live trapped birds were tested for arboviral antibodies to West Nile virus (WNV), St. Louis encephalitis, Eastern equine encephalitis, and Western equine encephalitis. A dead bird surveillance program was created in 2002 with the arrival of WNV in Harris County. Since implementation, the program has detected considerable variability in viral activity with annual WNV seroprevelance rates ranging from 2.9% to 17.7%, while the percentage of positive dead birds has ranged from 0.3% to 57.2%. In 2015, 1,345 live birds were sampled and 253 dead birds were tested, with WNV incidence rates of 16.5% and 5.9%, respectively.

Oxygen Buffering in High Pressure Solid Media Assemblies: New Approach Enabling Study of fO2 from IW-4 to IW+4.5

NASA Technical Reports Server (NTRS)

Righter, K.; Pando, K. M.; Ross, D. K.; Butterworth, A. L.; Gainsforth, Z.; Jilly-Rehak, C. E.; Westphal, A. J.

2017-01-01

Oxygen fugacity is an intensive parameter that controls some fundamental chemical and physical properties in planetary materials. In terrestrial magmas high fO2 promotes magnetite stability and low fO2 causes Fe-enrichment due to magnetite suppression. In lunar and asteroidal basalts, low fO2 can allow metal to be stable. Experimental studies will therefore be most useful if they are done at a specific and relevant fO2 for the samples under consideration. Control of fO2 in the solid media apparatus (piston cylinder multi-anvil) has relied on either sliding sensors or graphite capsule buffering, which are of limited application to the wide range of fO2 recorded in planetary or astromaterials. Here we describe a new approach that allows fO2 to be specified across a wide range of values relevant to natural samples.

Application of an integrated outbreak management plan for the control of leptospirosis in dairy cattle herds.

PubMed

Mughini-Gras, L; Bonfanti, L; Natale, A; Comin, A; Ferronato, A; La Greca, E; Patregnani, T; Lucchese, L; Marangon, S

2014-06-01

Two outbreaks of Leptospira borgpetersenii serovar Hardjo infection in dairy cattle herds were managed through the application of enhanced biosecurity measures, whole-herd antibiotic treatment and vaccination. Micro-agglutination test antibody titres were determined in paired serum samples at 3 weeks (T1: n = 125, 97% seropositivity, median 800, range 100-12 800) and 24 weeks (T2: n = 110, 88% seropositivity, median 200, range 100-6400) after vaccination and studied in relation to cows' age, herd of origin and sampling time. From T1 to T2, vaccine-elicited antibody titres decreased by 84·7% (95% CI 76·2-90·1). Consistent with increasing immunocompetence in calves (aged <12 months) and immunosenescence in adult cows (aged >36 months) associated with ageing, antibody titres correlated positively with calves' age and negatively with adult cows' age. No cow had cultivable, (histo)pathologically detectable and/or PCR-detectable leptospires in urine or kidney samples after treatment and vaccination. Vaccination together with proper biosecurity measures and chemoprophylaxis are an affordable insurance to control bovine leptospirosis.

Quality control of banked milk in Brasilia, Brazil.

PubMed

Almeida, Simone G; Dórea, José G

2006-08-01

The authors studied quality control procedures at human milk banks and nutritional profiles of 909 milk samples (from 195 donors, aged 15 to 45 years) from banked human milk (BHM) in Brasília, Brazil. Number of donations per donor ranged from 1 to > 10 that consisted mostly of mature milk (90.9%) with a mean total energy of 529 +/- 85 kcal/L and a mean total lipid of 22.7 g/L +/- 13.2. Microbiological quality (titrable acidity-Dornic, degrees D) was suitable for infant feeding in 99.2% of samples (< 8 degrees D), ranging from 2 degrees D to 8 degrees D (mean 4.8 +/- 1.4 degrees D). Most BHM (98.1%) samples were dispensed to inpatient infants (1-7 days) diagnosed with respiratory distress (30.1%), prematurity (20.7%), metabolic distress (16.0%), jaundice (14.4%), bacterial infection (6.0%), pneumonia (3.3%), congenital cardiac distress (2.2%), or other conditions (6.2%). Well-motivated mothers and trained staff are serving and sustaining an important life-saving network with long-lasting impact on public health.

Potential radiation control of biofouling bacteria on intake filters

NASA Astrophysics Data System (ADS)

Eichholz, Geoffrey G.; Jones, Cynthia G.; Haynes, Harold E.

The biofouling of filters at deep wells supplying water for industrial and drinking water purposes by various iron- and sulfur-reducing bacteria is a wide-spread problem in the United States and can cause serious economic losses. Among the means of control, steam heating or chemical additives can be applied only intermittently and have their own environmental impact. Preliminary studies have shown that installation of a sealed gamma radiation source may provide an alternative solution. Analysis of a range of water samples from contaminated wells identified many of the samples as rich in barsiderocapsa and barpseudomona bacteria. Static and dynamic experiments on water samples at various does and dose rates have shown that these organisms are relatively radiation-sensitive, with a lethal dose in the range of 200-400Gy (20-40kR). Since the main objective is to restrict growth or deposit of plaque on filters, dose rates of the order of 50-75 Gy/hr would be adequate. Such dose rates could be obtained with relatively weak sources, depending on filter dimensions. A conceptual design for such systems has been proposed.

Calorimetric system and method

DOEpatents

Gschneidner, K.A. Jr.; Pecharsky, V.K.; Moorman, J.O.

1998-09-15

Apparatus is described for measuring heat capacity of a sample where a series of measurements are taken in succession comprises a sample holder in which a sample to be measured is disposed, a temperature sensor and sample heater for providing a heat pulse thermally connected to the sample, and an adiabatic heat shield in which the sample holder is positioned and including an electrical heater. An electrical power supply device provides an electrical power output to the sample heater to generate a heat pulse. The electrical power from a power source to the heat shield heater is adjusted by a control device, if necessary, from one measurement to the next in response to a sample temperature-versus-time change determined before and after a previous heat pulse to provide a subsequent sample temperature-versus-time change that is substantially linear before and after the subsequent heat pulse. A temperature sensor is used and operable over a range of temperatures ranging from approximately 3K to 350K depending upon the refrigerant used. The sample optionally can be subjected to dc magnetic fields such as from 0 to 12 Tesla (0 to 120 kOe). 18 figs.

A flow-cytometry-based method for detecting simultaneously five allergens in a complex food matrix.

PubMed

Otto, Gaetan; Lamote, Amandine; Deckers, Elise; Dumont, Valery; Delahaut, Philippe; Scippo, Marie-Louise; Pleck, Jessica; Hillairet, Caroline; Gillard, Nathalie

2016-12-01

To avoid carry-over contamination with allergens, food manufacturers implement quality control strategies relying primarily on detection of allergenic proteins by ELISA. Although sensitive and specific, this method allowed detection of only one allergen per analysis and effective control policies were thus based on multiplying the number of tests done in order to cover the whole range of allergens. We present in this work an immunoassay for the simultaneous detection of milk, egg, peanut, mustard and crustaceans in cookies samples. The method was based on a combination of flow cytometry with competitive ELISA where microbeads were used as sorbent surface. The test was able to detect the presence of the five allergens with median inhibitory concentrations (IC50) ranging from 2.5 to 15 mg/kg according to the allergen to be detected. The lowest concentrations of contaminants inducing a significant difference of signal between non-contaminated controls and test samples were 2 mg/kg of peanut, 5 mg/kg of crustaceans, 5 mg/kg of milk, 5 mg/kg of mustard and 10 mg/kg of egg. Assay sensitivity was influenced by the concentration of primary antibodies added to the sample extract for the competition and by the concentration of allergenic proteins bound to the surface of the microbeads.

40 CFR 85.2233 - Steady state test equipment calibrations, adjustments, and quality control-EPA 91.

Code of Federal Regulations, 2013 CFR

2013-07-01

... tolerance range. The pressure in the sample cell must be the same with the calibration gas flowing during... this chapter. The check is done at 30 mph (48 kph), and a power absorption load setting to generate a... in § 85.2225(c)(1) are not met. (2) Leak checks. Each time the sample line integrity is broken, a...

40 CFR 85.2233 - Steady state test equipment calibrations, adjustments, and quality control-EPA 91.

Code of Federal Regulations, 2011 CFR

2011-07-01

... tolerance range. The pressure in the sample cell must be the same with the calibration gas flowing during... this chapter. The check is done at 30 mph (48 kph), and a power absorption load setting to generate a... in § 85.2225(c)(1) are not met. (2) Leak checks. Each time the sample line integrity is broken, a...

40 CFR 85.2233 - Steady state test equipment calibrations, adjustments, and quality control-EPA 91.

Code of Federal Regulations, 2012 CFR

2012-07-01

... tolerance range. The pressure in the sample cell must be the same with the calibration gas flowing during... this chapter. The check is done at 30 mph (48 kph), and a power absorption load setting to generate a... in § 85.2225(c)(1) are not met. (2) Leak checks. Each time the sample line integrity is broken, a...

Perceiving control: a double-edged sword in old age.

PubMed

Kunzmann, Ute; Little, Todd; Smith, Jacqui

2002-11-01

Although control beliefs are thought to be pivotal contributors to emotional well-being in old age, questions remain about the specific and long-term emotional implications of different types of control beliefs. We examined three generalized beliefs about control (personal control over desirable outcomes, personal responsibility for undesirable outcomes, perceived others' control) and their associations with emotional well-being (positive and negative affect) using cross-sectional (N = 516) and longitudinal (N = 206) samples from the Berlin Aging Study (age range = 70-103 years). Relationships between control beliefs and emotional well-being were dependent on the type of control belief and the dimension of emotional well-being considered, the sample investigated, and on whether individual differences at a given point in time or individual differences in intraindividual changes over time were examined. Despite these complexities, findings suggest that perceived control over desirable outcomes is associated with high emotional well-being, whereas perceived others' control is an emotional risk factor in old age.

Accuracy of qPCR for quantifying Leishmania kDNA in different skin layers of patients with American tegumentary leishmaniasis.

PubMed

Sevilha-Santos, L; Dos Santos Júnior, A C M; Medeiros-Silva, V; Bergmann, J O; da Silva, E F; Segato, L F; Arabi, A Y M; de Paula, N A; Sampaio, R N R; Lima, B D; Gomes, C M

2018-05-03

Superficial swab sampling of American tegumentary leishmaniasis (ATL) lesions shows higher amounts of Leishmania than those from biopsy. Subcutaneous involvement is also important in ATL, but parasite quantification according to lesion depth has not been evaluated. We aim to present the best depth at which sampling should be performed for molecular exams of ATL. Patients with a clinical presentation compatible with ATL were allocated to ATL and control groups. Qualitative and quantitative qPCR assays were performed using SYBR Green and primers amplifying the kDNA minicircle of Leishmania spp. in different skin layers, including the epidermis, the superior dermis, the inferior dermis, and the hypodermis. Fifty-nine patients were included in this study, including 40 who had been diagnosed with ATL and 19 controls. The number of parasites was greater in samples of the epidermis and superior dermis (159.1 × 10 6 , range 4.0-781.7, and 75.4 × 10 6 , range 8.0-244.5, mean Leishmania parasite equivalents per μg of tissue DNA, respectively) than those in samples of the inferior dermis and hypodermis (54.6, range 8.0-256.6, and 16.8 × 10 6 , range 8.0-24.1, mean Leishmania parasite equivalents per μg of tissue DNA, respectively). The best diagnostic accuracy was achieved in the superior dermis (77.9%) and was significantly greater than that in the hypodermis (63.3%; p 0.039). We conclude that superficial sampling can retrieve a greater quantity of parasites. Future studies of the role of transepidermal elimination as a mechanism of host defence in ATL must be performed as there is a considerable quantity of Leishmania kDNA in the epidermis. Copyright © 2018 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Development of a large color range for a paint company

NASA Astrophysics Data System (ADS)

McGinley, Peter

2002-06-01

Experience with the Master Palette system of 6000 colors lead to a specification for a new color range where the primary design feature is the control of the paint tint formula. This design approach met a market-derived requirement for sample pots and fractional-strength colors. The layout process employed was able to display the color capability of the paint system and generate an array of colors with controlled spacing similar to Master Palette. Updated pigment selections and the introduction of additional colored bases completed the system specification of improved opacity and every color being exterior durable.

Support for alcohol policies from drinkers in the City of Tshwane, South Africa: Data from the International Alcohol Control study.

PubMed

Parry, Charles D H; Trangenstein, Pamela; Lombard, Carl; Jernigan, David H; Morojele, Neo K

2018-04-01

South Africa is considering a range of alcohol policy reforms. This study aims to determine the magnitude of public support for 13 alcohol policies in the Tshwane Metropolitan Municipality and whether this varies by demographic factors and heavy drinking status. Data are from the South African arm of the International Alcohol Control study, a household survey of adult drinkers using a multistage stratified cluster random sampling design. The sample included 1920 drinkers aged 18-65 years (62% men), with complete drinking data for 16 drinking locations on 955 persons (510 heavy and 445 not heavy drinkers). Over half (53%) of the sample were found to be heavy drinkers. Support varied by alcohol policy, ranging from 31% to 77%, with support above 50% for 11 of the 13 policies. Policy support was higher for policies increasing the purchase age to 21 years (77%), addressing drink driving (58-76%) and restricting physical availability (60-66%). There was slightly less support for policies restricting alcohol marketing (59%) or for policies increasing the price of alcohol (34-58%), especially if no justification was given or the funds were not earmarked. Policy support differed by age, gender, heavy drinking status and income. Public support from adult drinkers for a range of alcohol policies is extensive and, as found elsewhere, was strongest for raising the minimum drinking age and lowest for increasing prices. The support from drinkers to increasing controls on alcohol could be one lever to getting control measures implemented. [Parry CDH, Trangenstein P, Lombard C, Jernigan DH, Morojele NK. Support for alcohol policies from drinkers in the City of Tshwane, South Africa: Data from the International Alcohol Control study. Drug Alcohol Rev 2017;00:000-000]. © 2017 The Authors Drug and Alcohol Review published by John Wiley & Sons Australia, Ltd on behalf of Australasian Professional Society on Alcohol and other Drugs.

Assessment of Type I Interferon Signaling in Pediatric Inflammatory Disease.

PubMed

Rice, Gillian I; Melki, Isabelle; Frémond, Marie-Louise; Briggs, Tracy A; Rodero, Mathieu P; Kitabayashi, Naoki; Oojageer, Anthony; Bader-Meunier, Brigitte; Belot, Alexandre; Bodemer, Christine; Quartier, Pierre; Crow, Yanick J

2017-02-01

Increased type I interferon is considered relevant to the pathology of a number of monogenic and complex disorders spanning pediatric rheumatology, neurology, and dermatology. However, no test exists in routine clinical practice to identify enhanced interferon signaling, thus limiting the ability to diagnose and monitor treatment of these diseases. Here, we set out to investigate the use of an assay measuring the expression of a panel of interferon-stimulated genes (ISGs) in children affected by a range of inflammatory diseases. A cohort study was conducted between 2011 and 2016 at the University of Manchester, UK, and the Institut Imagine, Paris, France. RNA PAXgene blood samples and clinical data were collected from controls and symptomatic patients with a genetically confirmed or clinically well-defined inflammatory phenotype. The expression of six ISGs was measured by quantitative polymerase chain reaction, and the median fold change was used to calculate an interferon score (IS) for each subject compared to a previously derived panel of 29 controls (where +2 SD of the control data, an IS of >2.466, is considered as abnormal). Results were correlated with genetic and clinical data. Nine hundred ninety-two samples were analyzed from 630 individuals comprising symptomatic patients across 24 inflammatory genotypes/phenotypes, unaffected heterozygous carriers, and controls. A consistent upregulation of ISG expression was seen in 13 monogenic conditions (455 samples, 265 patients; median IS 10.73, interquartile range (IQR) 5.90-18.41), juvenile systemic lupus erythematosus (78 samples, 55 patients; median IS 10.60, IQR 3.99-17.27), and juvenile dermatomyositis (101 samples, 59 patients; median IS 9.02, IQR 2.51-21.73) compared to controls (78 samples, 65 subjects; median IS 0.688, IQR 0.427-1.196), heterozygous mutation carriers (89 samples, 76 subjects; median IS 0.862, IQR 0.493-1.942), and individuals with non-molecularly defined autoinflammation (89 samples, 69 patients; median IS 1.07, IQR 0.491-3.74). An assessment of six ISGs can be used to define a spectrum of inflammatory diseases related to enhanced type I interferon signaling. If future studies demonstrate that the IS is a reactive biomarker, this measure may prove useful both in the diagnosis and the assessment of treatment efficacy.

Voltage-Controlled Spray Deposition of Multiwalled Carbon Nanotubes on Semiconducting and Insulating Substrates

NASA Astrophysics Data System (ADS)

Maulik, Subhodip; Sarkar, Anirban; Basu, Srismrita; Daniels-Race, Theda

2018-05-01

A facile, cost-effective, voltage-controlled, "single-step" method for spray deposition of surfactant-assisted dispersed carbon nanotube (CNT) thin films on semiconducting and insulating substrates has been developed. The fabrication strategy enables direct deposition and adhesion of CNT films on target samples, eliminating the need for substrate surface functionalization with organosilane binder agents or metal layer coatings. Spray coating experiments on four types of sample [bare silicon (Si), microscopy-grade glass samples, silicon dioxide (SiO2), and polymethyl methacrylate (PMMA)] under optimized control parameters produced films with thickness ranging from 40 nm to 6 μm with substantial surface coverage and packing density. These unique deposition results on both semiconducting and insulator target samples suggest potential applications of this technique in CNT thin-film transistors with different gate dielectrics, bendable electronics, and novel CNT-based sensing devices, and bodes well for further investigation into thin-film coatings of various inorganic, organic, and hybrid nanomaterials on different types of substrate.

Employing Solid Phase Microextraction as Extraction Tool for Pesticide Residues in Traditional Medicinal Plants

PubMed Central

Gondo, Thamani T.; Mmualefe, Lesego C.; Okatch, Harriet

2016-01-01

HS-SPME was optimised using blank plant sample for analysis of organochlorine pesticides (OCPs) of varying polarities in selected medicinal plants obtained from northern part of Botswana, where OCPs such as DDT and endosulfan have been historically applied to control disease carrying vectors (mosquitos and tsetse fly). The optimised SPME parameters were used to isolate analytes from root samples of five medicinal plants obtained from Maun and Kasane, Botswana. The final analytes determination was done with a gas chromatograph equipped with GC-ECD and analyte was confirmed using electron ionisation mass spectrometer (GC-MS). Dieldrin was the only pesticide detected and confirmed with MS in the Terminalia sericea sample obtained from Kasane. The method was validated and the analyte recoveries ranged from 69.58 ± 7.20 to 113 ± 15.44%, with RSDs ranging from 1.19 to 17.97%. The method indicated good linearity (R 2 > 0.9900) in the range of 2 to 100 ng g−1. The method also proved to be sensitive with low limits of detection (LODs) ranging from 0.48 ± 0.16 to 1.50 ± 0.50 ng g−1. It can be concluded that SPME was successfully utilized as a sampling and extraction tool for pesticides of diverse polarities in root samples of medicinal plants. PMID:27725893

Impulsivity, Mental Disorder, and Suicide in Rural China.

PubMed

Lin, Lin; Zhang, Jie

2017-01-02

The purpose of this study was to investigate the relationship among impulsivity, mental disorder, and suicide with a sample of rural young Chinese. Subjects were 392 consecutively recruited male and female suicides aged 15-34 years and 416 community male and female controls of the same age range sampled in rural China. The case-control data were obtained using psychological autopsy with structured and semi-structured instruments. Dysfunctional impulsivity was a significant risk factor regardless of mental disorder in rural China. Dysfunctional impulsivity is a potential area for further study of suicidal behavior. The suicide prevention efforts in rural China may address impulsivity.

Carbon nanotube scaffolds with controlled porosity as electromagnetic absorbing materials in the gigahertz range

NASA Astrophysics Data System (ADS)

González, M.; Crespo, M.; Baselga, J.; Pozuelo, J.

2016-05-01

Control of the microscopic structure of CNT nanocomposites allows modulation of the electromagnetic shielding in the gigahertz range. The porosity of CNT scaffolds has been controlled by two freezing protocols and a subsequent lyophilization step: fast freezing in liquid nitrogen and slow freezing at -20 °C. Mercury porosimetry shows that slowly frozen specimens present a more open pore size (100-150 μm) with a narrow distribution whereas specimens frozen rapidly show a smaller pore size and a heterogeneous distribution. 3D-scaffolds containing 3, 4, 6 and 7% CNT were infiltrated with epoxy and specimens with 2, 5 and 8 mm thicknesses were characterized in the GHz range. Samples with the highest pore size and porosity presented the lowest reflected power (about 30%) and the highest absorbed power (about 70%), which allows considering them as electromagnetic radiation absorbing materials.Control of the microscopic structure of CNT nanocomposites allows modulation of the electromagnetic shielding in the gigahertz range. The porosity of CNT scaffolds has been controlled by two freezing protocols and a subsequent lyophilization step: fast freezing in liquid nitrogen and slow freezing at -20 °C. Mercury porosimetry shows that slowly frozen specimens present a more open pore size (100-150 μm) with a narrow distribution whereas specimens frozen rapidly show a smaller pore size and a heterogeneous distribution. 3D-scaffolds containing 3, 4, 6 and 7% CNT were infiltrated with epoxy and specimens with 2, 5 and 8 mm thicknesses were characterized in the GHz range. Samples with the highest pore size and porosity presented the lowest reflected power (about 30%) and the highest absorbed power (about 70%), which allows considering them as electromagnetic radiation absorbing materials. Electronic supplementary information (ESI) available: Scheme of hydrogenated derivative of diglycidyl ether of bisphenol-A (HDGEBA) and m-xylylenediamine; X-ray diffractograms of pristine CNT and oxidized CNT; glass transition temperatures of composites; electromagnetic shielding analysis in the 1-18 GHz frequency range. See DOI: 10.1039/c6nr02133f

Note: Inter-satellite laser range-rate measurement by using digital phase locked loop.

PubMed

Liang, Yu-Rong; Duan, Hui-Zong; Xiao, Xin-Long; Wei, Bing-Bing; Yeh, Hsien-Chi

2015-01-01

This note presents an improved high-resolution frequency measurement system dedicated for the inter-satellite range-rate monitoring that could be used in the future's gravity recovery mission. We set up a simplified common signal test instead of the three frequencies test. The experimental results show that the dominant noises are the sampling time jitter and the thermal drift of electronic components, which can be reduced by using the pilot-tone correction and passive thermal control. The improved noise level is about 10(-8) Hz/Hz(1/2)@0.01Hz, limited by the signal-to-noise ratio of the sampling circuit.

Note: Inter-satellite laser range-rate measurement by using digital phase locked loop

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

Liang, Yu-Rong; Department of Electronics and Information Engineering, Huazhong University of Science and Technology, 1037 Luo Yu Road, Wuhan 430074; Duan, Hui-Zong

2015-01-15

This note presents an improved high-resolution frequency measurement system dedicated for the inter-satellite range-rate monitoring that could be used in the future’s gravity recovery mission. We set up a simplified common signal test instead of the three frequencies test. The experimental results show that the dominant noises are the sampling time jitter and the thermal drift of electronic components, which can be reduced by using the pilot-tone correction and passive thermal control. The improved noise level is about 10{sup −8} Hz/Hz{sup 1/2}@0.01Hz, limited by the signal-to-noise ratio of the sampling circuit.

Note: Inter-satellite laser range-rate measurement by using digital phase locked loop

NASA Astrophysics Data System (ADS)

Liang, Yu-Rong; Duan, Hui-Zong; Xiao, Xin-Long; Wei, Bing-Bing; Yeh, Hsien-Chi

2015-01-01

This note presents an improved high-resolution frequency measurement system dedicated for the inter-satellite range-rate monitoring that could be used in the future's gravity recovery mission. We set up a simplified common signal test instead of the three frequencies test. The experimental results show that the dominant noises are the sampling time jitter and the thermal drift of electronic components, which can be reduced by using the pilot-tone correction and passive thermal control. The improved noise level is about 10-8 Hz/Hz1/2@0.01Hz, limited by the signal-to-noise ratio of the sampling circuit.

Switch Hands! Mapping Proactive and Reactive Cognitive Control across the Life Span

ERIC Educational Resources Information Center

Van Gerven, Pascal W. M.; Hurks, Petra P. M.; Bovend'Eerdt, Thamar J. H.; Adam, Jos J.

2016-01-01

We investigated the effects of age on proactive and reactive cognitive control in a large population sample of 809 individuals, ranging in age between 5 and 97 years. For that purpose, we used an anticue paradigm, which required a consistent remapping of cue location and response hand: Left-sided cues required right-hand responses and vice versa.…

Characterization of controlled bone defects using 2D and 3D ultrasound imaging techniques.

PubMed

Parmar, Biren J; Longsine, Whitney; Sabonghy, Eric P; Han, Arum; Tasciotti, Ennio; Weiner, Bradley K; Ferrari, Mauro; Righetti, Raffaella

2010-08-21

Ultrasound is emerging as an attractive alternative modality to standard x-ray and CT methods for bone assessment applications. As of today, however, there is a lack of systematic studies that investigate the performance of diagnostic ultrasound techniques in bone imaging applications. This study aims at understanding the performance limitations of new ultrasound techniques for imaging bones in controlled experiments in vitro. Experiments are performed on samples of mammalian and non-mammalian bones with controlled defects with size ranging from 400 microm to 5 mm. Ultrasound findings are statistically compared with those obtained from the same samples using standard x-ray imaging modalities and optical microscopy. The results of this study demonstrate that it is feasible to use diagnostic ultrasound imaging techniques to assess sub-millimeter bone defects in real time and with high accuracy and precision. These results also demonstrate that ultrasound imaging techniques perform comparably better than x-ray imaging and optical imaging methods, in the assessment of a wide range of controlled defects both in mammalian and non-mammalian bones. In the future, ultrasound imaging techniques might provide a cost-effective, real-time, safe and portable diagnostic tool for bone imaging applications.

Fourier transform spectrometer for spectral emissivity measurement in the temperature range between 60 and 1500°C

NASA Astrophysics Data System (ADS)

Dai, Jingmin; Wang, Xinbei; Yuan, Guibin

2005-01-01

A new spectral emissivity measurement system has been developed at Harbin Institute of Technology (HIT) by using a Fourier transform infrared (FTIR) spectrometer. The spectral range between 0.6 and 25 µm was covered by a photovoltaic HgCdTe and a silicon photodiode detector. A SiC heater with a black hole was employed for heating the sample. The temperature of the sample can be controlled in a range between 60 and 1500°C with an error of less than 1°C. The system was calibrated against two high quality reference blackbodies: a low temperature heat-pipe blackbody operated in the temperature range between 60°C and 300°C and a high temperature blackbody with SiC heater operated in the temperature range between 300°C and 1500°C. Several tests were done for this new system. The estimated uncertainty of emissivity measurement is better than 3%.

Carbon nanotube scaffolds with controlled porosity as electromagnetic absorbing materials in the gigahertz range.

PubMed

González, M; Crespo, M; Baselga, J; Pozuelo, J

2016-05-19

Control of the microscopic structure of CNT nanocomposites allows modulation of the electromagnetic shielding in the gigahertz range. The porosity of CNT scaffolds has been controlled by two freezing protocols and a subsequent lyophilization step: fast freezing in liquid nitrogen and slow freezing at -20 °C. Mercury porosimetry shows that slowly frozen specimens present a more open pore size (100-150 μm) with a narrow distribution whereas specimens frozen rapidly show a smaller pore size and a heterogeneous distribution. 3D-scaffolds containing 3, 4, 6 and 7% CNT were infiltrated with epoxy and specimens with 2, 5 and 8 mm thicknesses were characterized in the GHz range. Samples with the highest pore size and porosity presented the lowest reflected power (about 30%) and the highest absorbed power (about 70%), which allows considering them as electromagnetic radiation absorbing materials.

Experimental design and modeling of a microscale differential thermal calorimeter for the purposes of cryopreservation

NASA Astrophysics Data System (ADS)

Armes, James L.

In order to develop successful cryopreservation protocols for various biological materials, it is necessary to determine the thermodynamic properties of nanoliter- scale biological samples: ranging from heat capacity to heat of fusion. Differential thermal analysis is a calorimetric technique which is efficacious at determining these thermodynamic properties and will help lend insight into the formation of intracellular ice which depends heavily on the rate at which the sample is cooled. If too much intracellular ice is formed during the cooling process, the biological material can be destroyed. To investigate the effects of a range of cooling and warming rates on a cell, a control system and data acquisition software has been developed for use with a custom microfabricated differential thermal analyzer (muDTA). Utilizing either an a-priori prediction of the muDTA's thermal response or an integrated software-based PID control system, the program developed allows for precise control over the cooling and warming rate of the muDTA. In order to enhance the accuracy of the a-priori predicted current profile, a 2D numeric model was developed of the muDTA. This model also has allowed for geometric optimization to be performed on the next generation prototype of the muDTA. The muDTA has been shown to accurately measure the freezing point and heat of fusion of deionized water samples, with sample volumes on the order of nanoliters. The heat capacity of dimethyl sulfoxide (DMSO) has also been experimentally determined.

Central role of TiO2 anatase grain boundaries on resistivity of CaCu3Ti4O12-based materials probed by Raman spectroscopy

NASA Astrophysics Data System (ADS)

De Almeida-Didry, Sonia; Autret, Cécile; Honstettre, Christophe; Lucas, Anthony; Zaghrioui, Mustapha; Pacreau, François; Gervais, François

2016-11-01

This study focuses on characterization and control of grain boundaries to enhance the properties of CaCu3Ti4O12 (CCTO) ceramics capacitors for industrial applications. A novel factor deals with TiO2 anatase revealed by Raman scattering in grain boundaries, found as a dominant parameter of largest sample resistivity, consistent with higher grain boundary resistivity and higher breakdown voltage. Four selected samples of CCTO-based compositions showing very different properties in terms of permittivity ranging from 1000 to 684 000 measured at 1 kHz, capacitance of grain boundaries ranging from 8 10-10 to 4.5 10-7 F cm-1, grain boundary resistivity ranging from 193 to 30,000,000 Ω cm and sample resistivity extending from 450 to 1011 Ω cm. The relationship between permittivity weighted by grain size and capacitance of grain boundaries confirms the internal barrier layer capacitance model over 5 orders of magnitude.

Coxsackievirus B4 as a Causative Agent of Diabetes Mellitus Type 1: Is There a Role of Inefficiently Treated Drinking Water and Sewage in Virus Spreading?

PubMed

El-Senousy, Waled M; Abdel-Moneim, Adel; Abdel-Latif, Mahmoud; El-Hefnawy, Mohamed H; Khalil, Rehab G

2018-03-01

This study proposed to detect the enterovirus (EV) infection in children with type 1 diabetes mellitus (T1D) and to assess the role of insufficiently treated water and sewage as sources of viral spreading. Three hundred and eighty-two serum specimens of children with T1D, one hundred serum specimens of children who did not suffer from T1D as control, and forty-eight water and sewage samples were screened for EV RNA using nested RT-PCR. The number of genome copies and infectious units of EVs in raw and treated sewage and water samples were investigated using real-time (RT)-PCR and plaque assay, respectively. T1D markers [Fasting blood glucose (FBG), HbA1c, and C-peptide], in addition to anti-Coxsackie A & B viruses (CVs A & B) IgG, were measured in control, T1D-negative EV (T1D-EV - ), and T1D-positive EV (T1D-EV + ) children specimens. The prevalence of EV genome was significantly higher in diabetic children (26.2%, 100 out of 382) than the control children (0%, 0 out of 100). FBG and HbA1c in T1D-EV - and T1D-EV + children specimens were significantly higher than those in the control group, while c-peptide in T1D-EV - and T1D-EV + children specimens was significantly lower than that in the control (n = 100; p < 0.001). Positivity of anti-CVs A & B IgG was 70.7, 6.7, and 22.9% in T1D-EV + , T1D-EV - , and control children specimens, respectively. The prevalence of EV genome in drinking water and treated sewage samples was 25 and 33.3%, respectively. The prevalence of EV infectious units in drinking water and treated sewage samples was 8.5 and 25%, respectively. Quantification assays were performed to assess the capabilities of both wastewater treatment plants (WWTPs) and water treatment plants (WTPs) to remove EV. The reduction of EV genome in Zenin WWTP ranged from 2 to 4 log 10 , while the reduction of EV infectious units ranged from 1 to 4 log 10 . The reduction of EV genome in El-Giza WTP ranged from 1 to 3 log 10 , while the reduction of EV infectious units ranged from 1 to 2 log 10 . This capability of reduction did not prevent the appearance of infectious EV in treated sewage and drinking water. Plaque purification was performed for isolation of separate EV isolates from treated and untreated water and sewage samples. Characterization of the EV amplicons by RT-PCR followed by sequencing of these isolates revealed high homology (97%) with human coxsackievirus B4 (CV B4) in 60% of the isolates, while the rest of the isolates belonged to poliovirus type 1 and type 2 vaccine strains. On the other hand, characterization of the EV amplicons by RT-PCR followed by sequencing for T1D-EV + children specimens indicated that all samples contained CV B4 with the same sequence characterized in the environmental samples. CV B4-contaminated drinking water or treated sewage may play a role as a causative agent of T1D in children.

Health hazard evaluation report heta 92-0160-2360, City of Lancaster, Division of Fire, Lancaster, Ohio

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

Echt, A.; Blade, L.; Sheehy, J.

1993-10-01

In response to a request from the Division of Fire and the International Association of Firefighters Local 291, an evaluation was undertaken of exposure to diesel exhaust emissions in the engine houses of the City of Lancaster Division of Fire (SIC-9224) Lancaster, Ohio. At the time of the study, 77 uniformed employees and two secretaries worked in three engine houses. In Engine House 1, personal breathing zone (PBZ) samples ranged from 51.7 to 71.2 micrograms per cubic meter (microg/cu m) on the first night of sampling. PBZ samples in Engine House 2 ranged from 25.7 to 78.8 microg/cu m overmore » two nights of sampling. Results for Engine House 3 ranged from 24.0 to 60.5 microg/cu m. With the exception of one measurement of 4.6 parts per million (ppm) of carbon-monoxide (CO) measured in the smoking room of Engine House 2, only trace CO was detected. Benzene solubles measured in Engine House 2 ranged from less than the limit of detection to 313 microg/cu m. The authors conclude that exhaust emissions containing diesel particulate may present a potential risk to firefighters. The authors recommend the use of engineering controls and work practices to reduce diesel exhaust emission exposures.« less

Determination of the herbicide fluroxypyr in oil matrices.

PubMed

Muhamad, Halimah B; Ai, Tan Yew; Sahid, Ismail B

2008-02-01

The purpose of this study was to develop a method for the determination of fluroxypyr (4-amino-3,5-dichloro-6-fluro2-pyridyloxyacetic acid) residue in palm oil namely crude palm oil (CPO) and crude palm kernel oil (CPKO). The method involves the extraction of the herbicide from the oil matrix followed by low temperature precipitation and finally quantification of the residues using the high performance liquid chromatography (HPLC). The extraction efficiency of the method was evaluated by conducting recovery studies. The recovery of fluroxypyr from the fortified CPO samples ranged from 78%-111% with the relative values for the coefficient of variation ranging from 1.4 to 8.6%. Furthermore, the recovery of fluroxypyr from the spiked CPKO samples ranged from 91-107% with the relative values for the coefficient of variation ranging from 0.6 to 4.5%. The minimum detection limit of fluroxypyr in CPO and CPKO was 0.05 microg/g. The method was used to determine fluroxypyr residues from the field-treated samples of CPO and CPKO. When fluroxypyr was used for weed control in oil palm plantations no residue was detected in CPO and CPKO irrespective of the sampling interval and the dosage applied at the recommended or double the manufacturer's recommended dosage.

Genetic variation in avocado stem weevils Copturus aguacatae (Coleoptera: Curculionidae) in Mexico.

PubMed

Engstrand, Rachel C; Cibrián Tovar, Juan; Cibrián-Jaramillo, Angélica; Kolokotronis, Sergios-Orestis

2010-12-01

The avocado stem weevil Copturus aguacatae is an important pest in avocado plantations. Its presence hinders the production and marketing of avocado in Mexico, the largest avocado producer worldwide. Biological control through pheromone synthesis, a strategy favored over chemical control in crops, is currently limited by difficult field identification of this species. Using DNA barcoding, we examine the patterns of genetic variation of C. aguacatae in avocado trees in Mexico to help facilitate its identification and biological control. We show that there is one single species of avocado stem weevil throughout the sampled sites in Mexico. Overall, haplotype diversity is high, with Oaxaca forming one distinct group and all other sampled populations are admixed irrespective of geographic origin. The results suggest that high gene flow is maintained in this species and that a global strategy for biocontrol can be designed and implemented throughout the sampled range.

The WWW as a research medium: an illustrative survey on paranormal belief.

PubMed

Göritz, A S; Schumacher, J

2000-06-01

Data collected with a short World Wide Web (WWW) survey on paranormal belief, age, sex, locus of control, extraversion, emotional and physical well-being, and mood were compared with findings from recent literature while controlling for effects of self-selection. Each variable was measured with one item. The sample comprised 342 women, 648 men, and 8 participants of unknown sex, of whom 76.7% were self-selected and 23.3% did not select themselves. There was a weak but, given the large sample, significant effect of self-selection regarding paranormal belief (rpb 932 = .08) but no relationships for paranormal belief and the examined variables. In the entire sample, statistically significant correlations ranging from .13 to .07 between paranormal belief and female sex, scores on external locus of control, good mood, extraversion, and emotional well-being corresponded with previous offline results.

Mechanical properties and failure behavior of unidirectional porous ceramics

NASA Astrophysics Data System (ADS)

Seuba, Jordi; Deville, Sylvain; Guizard, Christian; Stevenson, Adam J.

2016-04-01

We show that the honeycomb out-of-plane model derived by Gibson and Ashby can be applied to describe the compressive behavior of unidirectional porous materials. Ice-templating allowed us to process samples with accurate control over pore volume, size, and morphology. These samples allowed us to evaluate the effect of this microstructural variations on the compressive strength in a porosity range of 45-80%. The maximum strength of 286 MPa was achieved in the least porous ice-templated sample (P(%) = 49.9), with the smallest pore size (3 μm). We found that the out-of-plane model only holds when buckling is the dominant failure mode, as should be expected. Furthermore, we controlled total pore volume by adjusting solids loading and sintering temperature. This strategy allows us to independently control macroporosity and densification of walls, and the compressive strength of ice-templated materials is exclusively dependent on total pore volume.

Mechanical properties and failure behavior of unidirectional porous ceramics.

PubMed

Seuba, Jordi; Deville, Sylvain; Guizard, Christian; Stevenson, Adam J

2016-04-14

We show that the honeycomb out-of-plane model derived by Gibson and Ashby can be applied to describe the compressive behavior of unidirectional porous materials. Ice-templating allowed us to process samples with accurate control over pore volume, size, and morphology. These samples allowed us to evaluate the effect of this microstructural variations on the compressive strength in a porosity range of 45-80%. The maximum strength of 286 MPa was achieved in the least porous ice-templated sample (P(%) = 49.9), with the smallest pore size (3 μm). We found that the out-of-plane model only holds when buckling is the dominant failure mode, as should be expected. Furthermore, we controlled total pore volume by adjusting solids loading and sintering temperature. This strategy allows us to independently control macroporosity and densification of walls, and the compressive strength of ice-templated materials is exclusively dependent on total pore volume.

Coast Guard exposure to gasoline, MTBE, and benzene vapors during inspection of tank barges.

PubMed

Davenport, A C; Glynn, T J; Rhambarose, H

2000-01-01

A field study was conducted June through August 1996 in an attempt to quantify short-term exposure levels to Coast Guard personnel performing routine inspection activities aboard commercial tank barges carrying gasoline. Transfer and fleeting operations were monitored in the ports of Pittsburgh, Pa., Huntington, W.Va., Baton Rouge, La., and Galveston, Tex. A total of 43 personal and 68 area samples were analyzed for benzene and total hydrocarbons as gasoline ("gasoline"). Results can be summarized as follows: Personal exposure to benzene gave 15-min time-weighted-average (TWA) results ranging from <0.10 to 0.50 ppm. Area benzene levels ranged from <0.04 to 170 ppm. Personal monitoring for gasoline revealed a range of <2.0 to 590 mg/m3 with a GM of 23 mg/m3. Area sample results for gasoline ranged from 1.7 to 90,000 mg/m3. Twelve personal samples were collected for methyl-tert butyl ether (MTBE). Only two of these were above the limit of detection and had 15-min time-weighted averages of 22 ppm and 1.3 ppm. Eighteen MTBE area samples ranged in value from <3.0 to 38 ppm. Although none of the personal samples met or exceeded proposed or established short-term exposure standards, many of the area sampling results indicated that a significant risk of acute exposure exists in the vicinity of valves, pressure lines, and connections. This includes anticipated sources such as pressure vent valves as well as unexpected sources resulting from structural deficiencies onboard the vessels. These results further emphasize the value of safe work practices and proper vessel maintenance in controlling exposure to harmful chemicals.

Diagenetic and compositional controls of wettability in siliceous sedimentary rocks, Monterey Formation, California

NASA Astrophysics Data System (ADS)

Hill, Kristina M.

Modified imbibition tests were performed on 69 subsurface samples from Monterey Formation reservoirs in the San Joaquin Valley to measure wettability variation as a result of composition and silica phase change. Contact angle tests were also performed on 6 chert samples from outcrop and 3 nearly pure mineral samples. Understanding wettability is important because it is a key factor in reservoir fluid distribution and movement, and its significance rises as porosity and permeability decrease and fluid interactions with reservoir grain surface area increase. Although the low permeability siliceous reservoirs of the Monterey Formation are economically important and prolific, a greater understanding of factors that alter their wettability will help better develop them. Imbibition results revealed a strong trend of decreased wettability to oil with increased detrital content in opal-CT phase samples. Opal-A phase samples exhibited less wettability to oil than both opal-CT and quartz phase samples of similar detrital content. Subsurface reservoir samples from 3 oil fields were crushed to eliminate the effect of capillary pressure and cleansed of hydrocarbons to eliminate wettability alterations by asphaltene, then pressed into discs of controlled density. Powder discs were tested for wettability by dispensing a controlled volume of water and motor oil onto the surface and measuring the time required for each fluid to imbibe into the sample. The syringe and software of a CAM101 tensiometer were used to control the amount of fluid dispensed onto each sample, and imbibition completion times were determined by high-speed photography for water drops; oil drop imbibition was significantly slower and imbibition was timed and determined visually. Contact angle of water and oil drops on polished chert and mineral sample surfaces was determined by image analysis and the Young-Laplace equation. Oil imbibition was significantly slower with increased detrital composition and faster with increased silica content in opal-CT and quartz phase samples, implying decreased wettability to oil with increased detrital (clay) content. However, contact angle tests showed that opal-CT is more wetting to oil with increased detritus and results for oil on quartz-phase samples were inconsistent between different proxies for detritus over their very small compositional range. Water contact angle trends also showed inconsistent wetting trends compared to imbibition tests. We believe this is because the small range in bulk detrital composition between the "pure" samples used in contact angle tests was close to analytical error and because small-scale spatial compositional variability may be significant enough to effect wettability. These experiments show that compositional variables significantly affect wettability, outweighing the effect of silica phase.

Application of in-plant control measures in some Egyptian micro-scale dairy enterprises and its impact on heavy metal contents of their products.

PubMed

Abd El-Salam, Magda Magdy; Farahat, Mohamed F; Abu-Zuid, Gaber I; Saad, Samia G

2017-09-05

Egypt is encouraging micro-scale enterprises as proved to be one of the most important reasons of economic growth. Most of the annual milk production is processed in micro-scale dairy enterprises located in squatter areas with high health risks and negative environmental impact. The aim of this study was to assess the effectiveness of in-plant control measures in controlling lead and cadmium levels in dairy products from nine Egyptian micro-scale enterprises. The results revealed that white cheese enterprises had the highest mean lead and cadmium contents; both in their raw milk (0.712 and 0.134 mg/L, respectively) and final products (0.419 and 0.061 mg/kg). Higher compliance percentages were found with cadmium levels specified in the Egyptian standards than with lead levels and ranged from 59.4% in raw milk to 100% in dry milk for cadmium levels and from 8.3% in white cheese to 66.7% in ice cream for lead; moreover, none of the collected raw milk samples were complying with the lead levels. After implementation of in-plant control measures, lower lead levels were found in all samples with reduction percentages ranging from 35.2% in raw milk from the ice cream enterprises to 73.2% in yoghurt; moreover, higher percentages of samples complied with cadmium levels. This study highlights the urgent need for applying in-plant control measures to the Egyptian micro-scale dairy enterprises to improve both safety and quality of their products.

Quantification of dsDNA using the Hitachi F-7000 Fluorescence Spectrophotometer and PicoGreen dye.

PubMed

Moreno, Luis A; Cox, Kendra L

2010-11-05

Quantification of DNA, especially in small concentrations, is an important task with a wide range of biological applications including standard molecular biology assays such as synthesis and purification of DNA, diagnostic applications such as quantification of DNA amplification products, and detection of DNA molecules in drug preparations. During this video we will demonstrate the capability of the Hitachi F-7000 Fluorescence Spectrophotometer equipped with a Micro Plate Reader accessory to perform dsDNA quantification using Molecular Probes Quant-it PicoGreen dye reagent kit. The F-7000 Fluorescence Spectrophotometer offers high sensitivity and high speed measurements. It is a highly flexible system capable of measuring fluorescence, luminescence, and phosphorescence. Several measuring modes are available, including wavelength scan, time scan, photometry and 3-D scan measurement. The spectrophotometer has sensitivity in the range of 50 picomoles of fluorescein when using a 300 μL sample volume in the microplate, and is capable of measuring scan speeds of 60,000 nm/minute. It also has a wide dynamic range of up to 5 orders of magnitude which allows for the use of calibration curves over a wide range of concentrations. The optical system uses all reflective optics for maximum energy and sensitivity. The standard wavelength range is 200 to 750 nm, and can be extended to 900 nm when using one of the optional near infrared photomultipliers. The system allows optional temperature control for the plate reader from 5 to 60 degrees Celsius using an optional external temperature controlled liquid circulator. The microplate reader allows for the use of 96 well microplates, and the measuring speed for 96 wells is less than 60 seconds when using the kinetics mode. Software controls for the F-7000 and Microplate Reader are also highly flexible. Samples may be set in either column or row formats, and any combination of wells may be chosen for sample measurements. This allows for optimal utilization of the microplate. Additionally, the software allows importing micro plate sample configurations created in Excel and saved in comma separated values, or "csv" format. Microplate measuring configurations can be saved and recalled by the software for convenience and increased productivity. Data results can be output to a standard report, to Excel, or to an optional Report Generator Program.

Quantification of dsDNA using the Hitachi F-7000 Fluorescence Spectrophotometer and PicoGreen Dye

PubMed Central

Moreno, Luis A.; Cox, Kendra L.

2010-01-01

Quantification of DNA, especially in small concentrations, is an important task with a wide range of biological applications including standard molecular biology assays such as synthesis and purification of DNA, diagnostic applications such as quantification of DNA amplification products, and detection of DNA molecules in drug preparations. During this video we will demonstrate the capability of the Hitachi F-7000 Fluorescence Spectrophotometer equipped with a Micro Plate Reader accessory to perform dsDNA quantification using Molecular Probes Quant-it PicoGreen dye reagent kit. The F-7000 Fluorescence Spectrophotometer offers high sensitivity and high speed measurements. It is a highly flexible system capable of measuring fluorescence, luminescence, and phosphorescence. Several measuring modes are available, including wavelength scan, time scan, photometry and 3-D scan measurement. The spectrophotometer has sensitivity in the range of 50 picomoles of fluorescein when using a 300 μL sample volume in the microplate, and is capable of measuring scan speeds of 60,000 nm/minute. It also has a wide dynamic range of up to 5 orders of magnitude which allows for the use of calibration curves over a wide range of concentrations. The optical system uses all reflective optics for maximum energy and sensitivity. The standard wavelength range is 200 to 750 nm, and can be extended to 900 nm when using one of the optional near infrared photomultipliers. The system allows optional temperature control for the plate reader from 5 to 60 degrees Celsius using an optional external temperature controlled liquid circulator. The microplate reader allows for the use of 96 well microplates, and the measuring speed for 96 wells is less than 60 seconds when using the kinetics mode. Software controls for the F-7000 and Microplate Reader are also highly flexible. Samples may be set in either column or row formats, and any combination of wells may be chosen for sample measurements. This allows for optimal utilization of the microplate. Additionally, the software allows importing micro plate sample configurations created in Excel and saved in comma separated values, or "csv" format. Microplate measuring configurations can be saved and recalled by the software for convenience and increased productivity. Data results can be output to a standard report, to Excel, or to an optional Report Generator Program. PMID:21189464

Distribution and phylogenetic analysis of Blastocystis sp. subtypes isolated from IBD patients and healthy individuals in Iran.

PubMed

Mirjalali, H; Abbasi, M R; Naderi, N; Hasani, Z; Mirsamadi, E S; Stensvold, C R; Balaii, H; Asadzadeh Aghdaei, H; Zali, M R

2017-12-01

Blastocystis is a single-celled intestinal parasite commonly found in humans and a broad range of animals all over the world. In humans, its role in health and disease remains unsettled. The aim of our study was to investigate the distribution of Blastocystis and Blastocystis subtypes (ST) in patients with inflammatory bowel disease (IBD) and control subjects. A total of 71 stool samples were collected from IBD patients, 69 and 2 of whom had ulcerative colitis (UC) and Crohn's Disease (CD), respectively. Moreover, 166 stool samples from healthy subjects were included as control samples. All stool samples were cultivated, and 550-bp fragments of the small subunit ribosomal RNA gene was amplified from Blastocystis-positive cultures. All PCR-positive samples were sequenced. Blastocystis was observed in 9 (12.67%) and 35 (21.1%) IBD patients and healthy controls, respectively. There was no statistically significant correlation between IBD and presence of Blastocystis (P = 0.147). There was a statistically significant correlation between age and Blastocystis colonization in the IBD group (P < 0.05), but not among healthy controls. No significant correlation between gender and colonization was observed. ST1 and ST3 were obtained from 1 (12.5%) and 7 (87.5%) IBD patients, respectively, while in the healthy control group, subtypes 1, 2, and 3 were found in 14 (40%), 12 (34.28%), and 9 (25.72%), respectively. Phylogenetic analysis showed no variation in the distribution of subtypes nor intra-subtype genetic diversity between samples acquired from IBD patients and healthy controls. This study showed a trend towards a lower prevalence of Blastocystis in IBD patients than in control subjects. ST3 sequences isolated from IBD patients and control individuals did not appear to differ genetically.

Hypertension among older adults in low- and middle-income countries: prevalence, awareness and control

PubMed Central

Lloyd-Sherlock, Peter; Beard, John; Minicuci, Nadia; Ebrahim, Shah; Chatterji, Somnath

2014-01-01

Background This study uses data from the World Health Organization’s Study on Global Ageing and Adult Health (SAGE) to examine patterns of hypertension prevalence, awareness, treatment and control for people aged 50 years and over in China, Ghana, India, Mexico, the Russian Federation and South Africa. Methods The SAGE sample comprises of 35 125 people aged 50 years and older, selected randomly. Hypertension was defined as ≥140 mmHg (systolic blood pressure) or ≥90 mmHg (diastolic blood pressure) or by currently taking antihypertensives. Control of hypertension was defined as blood pressure below 140/90 mmHg on treatment. A person was defined as aware if he/she was hypertensive and self-reported the condition. Results Prevalence rates in all countries are broadly comparable to those of developed countries (52.9%; range 32.3% in India to 77.9% in South Africa). Hypertension was associated with overweight/obesity and was more common in women, those in the lowest wealth quintile and in heavy alcohol consumers. Awareness was found to be low for all countries, albeit with substantial national variations (48.3%; range 23.3% in Ghana to 72.1% in the Russian Federation). This was also the case for control (10.2%; range 4.1% in Ghana to 14.1% India) and treatment efficacy (26.3%; range 17.4% in the Russian Federation to 55.2% in India). Awareness was associated with increasing age, being female and being overweight or obese. Effective control of hypertension was more likely in older people, women and in the richest quintile. Obesity was associated with poorer control. Conclusions The high rates of hypertension in low- and middle-income countries are striking. Levels of treatment and control are inadequate despite half those sampled being aware of their condition. Since cardiovascular disease is by far the largest cause of years of life lost in these settings, these findings emphasize the need for new approaches towards control of this major risk factor. PMID:24505082

Airborne emissions of carcinogens and respiratory sensitizers during thermal processing of plastics.

PubMed

Unwin, John; Coldwell, Matthew R; Keen, Chris; McAlinden, John J

2013-04-01

Thermoplastics may contain a wide range of additives and free monomers, which themselves may be hazardous substances. Laboratory studies have shown that the thermal decomposition products of common plastics can include a number of carcinogens and respiratory sensitizers, but very little information exists on the airborne contaminants generated during actual industrial processing. The aim of this work was to identify airborne emissions during thermal processing of plastics in real-life, practical applications. Static air sampling was conducted at 10 industrial premises carrying out compounding or a range of processes such as extrusion, blown film manufacture, vacuum thermoforming, injection moulding, blow moulding, and hot wire cutting. Plastics being processed included polyvinyl chloride, polythene, polypropylene, polyethylene terephthalate, and acrylonitrile-butadiene-styrene. At each site, static sampling for a wide range of contaminants was carried out at locations immediately adjacent to the prominent fume-generating processes. The monitoring data indicated the presence of few carcinogens at extremely low concentrations, all less than 1% of their respective WEL (Workplace Exposure Limit). No respiratory sensitizers were detected at any sites. The low levels of process-related fume detected show that the control strategies, which employed mainly forced mechanical general ventilation and good process temperature control, were adequate to control the risks associated with exposure to process-related fume. This substantiates the advice given in the Health and Safety Executive's information sheet No 13, 'Controlling Fume During Plastics Processing', and its broad applicability in plastics processing in general.

Automated force controller for amplitude modulation atomic force microscopy

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

Miyagi, Atsushi, E-mail: atsushi.miyagi@inserm.fr, E-mail: simon.scheuring@inserm.fr; Scheuring, Simon, E-mail: atsushi.miyagi@inserm.fr, E-mail: simon.scheuring@inserm.fr

Atomic Force Microscopy (AFM) is widely used in physics, chemistry, and biology to analyze the topography of a sample at nanometer resolution. Controlling precisely the force applied by the AFM tip to the sample is a prerequisite for faithful and reproducible imaging. In amplitude modulation (oscillating) mode AFM, the applied force depends on the free and the setpoint amplitudes of the cantilever oscillation. Therefore, for keeping the applied force constant, not only the setpoint amplitude but also the free amplitude must be kept constant. While the AFM user defines the setpoint amplitude, the free amplitude is typically subject to uncontrollablemore » drift, and hence, unfortunately, the real applied force is permanently drifting during an experiment. This is particularly harmful in biological sciences where increased force destroys the soft biological matter. Here, we have developed a strategy and an electronic circuit that analyzes permanently the free amplitude of oscillation and readjusts the excitation to maintain the free amplitude constant. As a consequence, the real applied force is permanently and automatically controlled with picoNewton precision. With this circuit associated to a high-speed AFM, we illustrate the power of the development through imaging over long-duration and at various forces. The development is applicable for all AFMs and will widen the applicability of AFM to a larger range of samples and to a larger range of (non-specialist) users. Furthermore, from controlled force imaging experiments, the interaction strength between biomolecules can be analyzed.« less

Development of a flow controller for long-term sampling of gases and vapors using evacuated canisters.

PubMed

Rossner, Alan; Farant, Jean Pierre; Simon, Philippe; Wick, David P

2002-11-15

Anthropogenic activities contribute to the release of a wide variety of volatile organic compounds (VOC) into microenvironments. Developing and implementing new air sampling technologies that allow for the characterization of exposures to VOC can be useful for evaluating environmental and health concerns arising from such occurrences. A novel air sampler based on the use of a capillary flow controller connected to evacuated canisters (300 mL, 1 and 6 L) was designed and tested. The capillary tube, used to control the flow of air, is a variation on a sharp-edge orifice flow controller. It essentially controls the velocity of the fluid (air) as a function of the properties of the fluid, tube diameter and length. A model to predict flow rate in this dynamic system was developed. The mathematical model presented here was developed using the Hagen-Poiseuille equation and the ideal gas law to predict flow into the canisters used to sample for long periods of time. The Hagen-Poiseuille equation shows the relationship between flow rate, pressure gradient, capillary resistance, fluid viscosity, capillary length and diameter. The flow rates evaluated were extremely low, ranging from 0.05 to 1 mL min(-1). The model was compared with experimental results and was shown to overestimate the flow rate. Empirical equations were developed to more accurately predict flow for the 300 mL, 1 and 6 L canisters used for sampling periods ranging from several hours to one month. The theoretical and observed flow rates for different capillary geometries were evaluated. Each capillary flow controller geometry that was tested was found to generate very reproducible results, RSD < 2%. Also, the empirical formulas developed to predict flow rate given a specified diameter and capillary length were found to predict flow rate within 6% of the experimental data. The samplers were exposed to a variety of airborne vapors that allowed for comparison of the effectiveness of capillary flow controllers to sorbent samplers and to an online gas chromatograph. The capillary flow controller was found to exceed the performance of the sorbent samplers in this comparison.

Development of a split-flow system for high precision variable sample introduction in supercritical fluid chromatography.

PubMed

Sakai, Miho; Hayakawa, Yoshihiro; Funada, Yasuhiro; Ando, Takashi; Fukusaki, Eiichiro; Bamba, Takeshi

2017-09-15

In this study, we propose a novel variable sample injection system based on full-loop injection, named the split-flow sample introduction system, for application in supercritical fluid chromatography (SFC). In this system, the mobile phase is split by the differential pressure between two back pressure regulators (BPRs) after full-loop injection suitable for SFC, and this differential pressure determines the introduction rate. Nine compounds with a wide range of characteristics were introduced with high reproducibility and universality, confirming that a robust variable sample injection system was achieved. We also investigated the control factors of our proposed system. Sample introduction was controlled by the ratio between the column-side pressure drops in splitless and split flow, ΔP columnsideinsplitless and ΔP columnsideinsplit , respectively, where ΔP columnsideinsplitless is related to the mobile phase flow rate and composition and the column resistance. When all other conditions are kept constant, increasing the make-up flow induces an additional pressure drop on the column side of the system, which leads to a reduced column-side flow rate, and hence decreased the amount of sample injected, even when the net pressure drop on the column side remains the same. Thus, sample introduction could be highly controlled at low sample introduction rate, regardless of the introduction conditions. This feature is advantageous because, as a control factor, the solvent in the make-up pump is independent of the column-side pressure drop. Copyright © 2017. Published by Elsevier B.V.

Temperature-controlled micro-TLC: a versatile green chemistry and fast analytical tool for separation and preliminary screening of steroids fraction from biological and environmental samples.

PubMed

Zarzycki, Paweł K; Slączka, Magdalena M; Zarzycka, Magdalena B; Bartoszuk, Małgorzata A; Włodarczyk, Elżbieta; Baran, Michał J

2011-11-01

This paper is a continuation of our previous research focusing on development of micro-TLC methodology under temperature-controlled conditions. The main goal of present paper is to demonstrate separation and detection capability of micro-TLC technique involving simple analytical protocols without multi-steps sample pre-purification. One of the advantages of planar chromatography over its column counterpart is that each TLC run can be performed using non-previously used stationary phase. Therefore, it is possible to fractionate or separate complex samples characterized by heavy biological matrix loading. In present studies components of interest, mainly steroids, were isolated from biological samples like fish bile using single pre-treatment steps involving direct organic liquid extraction and/or deproteinization by freeze-drying method. Low-molecular mass compounds with polarity ranging from estetrol to progesterone derived from the environmental samples (lake water, untreated and treated sewage waters) were concentrated using optimized solid-phase extraction (SPE). Specific bands patterns for samples derived from surface water of the Middle Pomerania in northern part of Poland can be easily observed on obtained micro-TLC chromatograms. This approach can be useful as simple and non-expensive complementary method for fast control and screening of treated sewage water discharged by the municipal wastewater treatment plants. Moreover, our experimental results show the potential of micro-TLC as an efficient tool for retention measurements of a wide range of steroids under reversed-phase (RP) chromatographic conditions. These data can be used for further optimalization of SPE or HPLC systems working under RP conditions. Furthermore, we also demonstrated that micro-TLC based analytical approach can be applied as an effective method for the internal standard (IS) substance search. Generally, described methodology can be applied for fast fractionation or screening of the whole range of target substances as well as chemo-taxonomic studies and fingerprinting of complex mixtures, which are present in biological or environmental samples. Due to low consumption of eluent (usually 0.3-1mL/run) mainly composed of water-alcohol binary mixtures, this method can be considered as environmentally friendly and green chemistry focused analytical tool, supplementary to analytical protocols involving column chromatography or planar micro-fluidic devices. Copyright © 2011 Elsevier Ltd. All rights reserved.

In-depth survey report: Assisting furniture strippers in reducing the risk from methylene chloride stripping formulations at Los Angeles Stripping and Refinishing Center, Los Angeles, California

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

Estill, C.F.; Kovein, R.J.; Jones, J.H.

1999-03-26

The National Institute for Occupational Safety and Health (NIOSH) is currently conducting research on ventilation controls to reduce furniture stripping exposures to methylene chloride to the OSHA PEL of 25 ppm. Low cost ventilation systems were designed by NIOSH researchers along with Benny Bixenman of Benco Sales, Inc. (Forney, TX). The controls were constructed and installed by Benco Sales. This report compares the methylene chloride levels of one worker stripping furniture using the recently installed ventilation controls and using the existing controls. During the survey, two different chemical stripping solutions (a standard formulation and a low methylene chloride content formulation)more » were used and compared. This survey tested three control combinations: (1) new ventilation, low methylene chloride stripper, (2) new ventilation, standard stripping solution, and (3) old ventilation, standard stripping solution. During each test, sorbent tube sampling and real-time sampling were employed. Sorbent tube, data collected in the worker's breathing zone, ranged from 300 to 387 ppm. Real-time data showed breathing zone exposures to range from 211 to 383 ppm while stripping and 164 to 230 ppm while rinsing. Data were inconclusive to determine which ventilation system or stripping solution produced the lowest exposures. Recommendations are made in the report to improve the newly installed ventilation controls.« less

Free-running waveform characterization using a delay-time tunable laser based delay-line-free electro-optic sampling oscilloscope

NASA Astrophysics Data System (ADS)

Lin, Gong-Ru

2002-12-01

We develop a delay-line-free and frequency traceable electro-optic sampling oscilloscope by use of a digital phase-locked loop phase shifter (PLL-PS) controlled delay-time-tunable gain-switched laser diode (GSLD). The home-made voltage-controllable PLL-PS exhibits a linear transfer function with ultra-wide phase shifting range of ±350° and tuning error of <±5%, which benefits the advantages of frequency tracking to free-running signals with suppressed timing-jitter. The maximum delay-time of PLL-PS controlled GSLD is up to 1.95 periods by changing the controlling voltage ( VREF) from -3.5 to 3.5 V, which corresponds to 3.9 ns at repetition frequency of 500 MHz. The tuning responsivity and resolution are about 0.56 ns/V and 0.15˜0.2 ps, respectively. The maximum delay-time switching bandwidth of 100 Hz is determined under the control of a saw-tooth modulated VREF function. The waveform sampling of microwave PECL signals generated from a free-running digital frequency divider is performed with acceptable measuring deviation.

Bee honey as an environmental bioindicator of pesticides' occurrence in six agricultural areas of Greece.

PubMed

Balayiannis, George; Balayiannis, Panos

2008-10-01

The pollution of six agricultural areas of Greece (north, central, south) by insecticides used in crop protection has been investigated utilizing, as a bioindicator, bee honey produced in those areas. Honey samples collected randomly from apiaries located in those areas were analyzed for pesticide residues with a multianalytical method, able to determine simultaneously up to 10 organophosphorous insecticides from the same honey extract. Findings concerning the acaricide coumaphos were also included, even though it is not used in crop protection. Coumaphos is used to control the mite Varroa destructor, an external parasite of the honeybee. The above areas are cultivated in large extent with citrus trees or cotton or sunflower crops, which are good forages for honeybees. The main pests of those crops are insects; hence, insecticides are used on a large scale for crop protection. The most contaminated samples originated from citrus groves; 16 out of 19 had pesticide residues: 4 samples had chlorfenvinphos (21.05%), 10 had chlorpyrifos (52.63%) and 2 had phorate (10.53%). Out of 17 samples from cotton fields, residues were found in 8, phorate in 6 (35.29%), chlorfenvinphos in 1 (5.88%), and chlorpyrifos in 1 (5.88%). Out of nine samples from fields of sunflower, four had phorate residues (44.44%). In brief, from the 50 analyzed samples, residues of chlorfenvinphos were detected in 5 samples (10%), residues of chlorpyrifos in 11 samples (22%), and residues of phorate in 12 samples (24%). Their levels ranged between 0.70 and 0.89 microg/kg. Coumaphos residues ranged from 0.10 up to 4.80 microg/kg and were derived exclusively from beehives treated with Perizin (the commercial formulation of coumaphos) for Varroa control. This study indicates that in agricultural areas with developed apiculture, useful information about the occurrence and the distribution of pesticide residues due to crop protection treatments can be derived from the analysis of randomly collected honey samples, used as bioindicators. It also shows that, very often, the chemicals used by apiculturists inside the hives in order to control disease are the main pollutants of the produced honey.

Effects of historical climate change, habitat connectivity, and vicariance on genetic structure and diversity across the range of the Red Tree Vole (Phenacomys longicaudus) in the Pacific Northwest United States

USGS Publications Warehouse

Miller, Mark P.; Bellinger, R.M.; Forsman, E.D.; Haig, Susan M.

2006-01-01

Phylogeographical analyses conducted in the Pacific Northwestern United States have often revealed concordant patterns of genetic diversity among taxa. These studies demonstrate distinct North/South genetic discontinuities that have been attributed to Pleistocene glaciation. We examined phylogeographical patterns of red tree voles (Phenacomys longicaudus) in western Oregon by analysing mitochondrial control region sequences for 169 individuals from 18 areas across the species' range. Cytochrome b sequences were also analysed from a subset of our samples to confirm the presence of major haplotype groups. Phylogenetic network analyses suggested the presence of two haplotype groups corresponding to northern and southern regions of P. longicaudus' range. Spatial genetic analyses (samova and Genetic Landscape Shapes) of control region sequences demonstrated a primary genetic discontinuity separating northern and southern sampling areas, while a secondary discontinuity separated northern sampling areas into eastern and western groups divided by the Willamette Valley. The North/South discontinuity likely corresponds to a region of secondary contact between lineages rather than an overt barrier. Although the Cordilleran ice sheet (maximum a??12 000 years ago) did not move southward to directly affect the region occupied by P. longicaudus, climate change during glaciation fragmented the forest landscape that it inhabits. Signatures of historical fragmentation were reflected by positive associations between latitude and variables such as Tajima's D and patterns associated with location-specific alleles. Genetic distances between southern sampling areas were smaller, suggesting that forest fragmentation was reduced in southern vs. northern regions.

Infrared Sensor-Based Temperature Control for Domestic Induction Cooktops

PubMed Central

Lasobras, Javier; Alonso, Rafael; Carretero, Claudio; Carretero, Enrique; Imaz, Eduardo

2014-01-01

In this paper, a precise real-time temperature control system based on infrared (IR) thermometry for domestic induction cooking is presented. The temperature in the vessel constitutes the control variable of the closed-loop power control system implemented in a commercial induction cooker. A proportional-integral controller is applied to establish the output power level in order to reach the target temperature. An optical system and a signal conditioning circuit have been implemented. For the signal processing a microprocessor with 12-bit ADC and a sampling rate of 1 Ksps has been used. The analysis of the contributions to the infrared radiation permits the definition of a procedure to estimate the temperature of the vessel with a maximum temperature error of 5 °C in the range between 60 and 250 °C for a known cookware emissivity. A simple and necessary calibration procedure with a black-body sample is presented. PMID:24638125

Infrared sensor-based temperature control for domestic induction cooktops.

PubMed

Lasobras, Javier; Alonso, Rafael; Carretero, Claudio; Carretero, Enrique; Imaz, Eduardo

2014-03-14

In this paper, a precise real-time temperature control system based on infrared (IR) thermometry for domestic induction cooking is presented. The temperature in the vessel constitutes the control variable of the closed-loop power control system implemented in a commercial induction cooker. A proportional-integral controller is applied to establish the output power level in order to reach the target temperature. An optical system and a signal conditioning circuit have been implemented. For the signal processing a microprocessor with 12-bit ADC and a sampling rate of 1 Ksps has been used. The analysis of the contributions to the infrared radiation permits the definition of a procedure to estimate the temperature of the vessel with a maximum temperature error of 5 °C in the range between 60 and 250 °C for a known cookware emissivity. A simple and necessary calibration procedure with a black-body sample is presented.

Dilatometer setup for low coefficient of thermal expansion materials measurements in the 140 K-250 K temperature range.

PubMed

Spannagel, Ruven; Hamann, Ines; Sanjuan, Josep; Schuldt, Thilo; Gohlke, Martin; Johann, Ulrich; Weise, Dennis; Braxmaier, Claus

2016-10-01

Space applications demand light weight materials with excellent dimensional stability for telescopes, optical benches, optical resonators, etc. Glass-ceramics and composite materials can be tuned to reach very low coefficient of thermal expansion (CTE) at different temperatures. In order to determine such CTEs, very accurate setups are needed. Here we present a dilatometer that is able to measure the CTE of a large variety of materials in the temperature range of 140 K to 250 K. The dilatometer is based on a heterodyne interferometer with nanometer noise levels to measure the expansion of a sample when applying small amplitude controlled temperature signals. In this article, the CTE of a carbon fiber reinforced polymer sample has been determined with an accuracy in the 10 -8 K -1 range.

Enhanced Cumulative Sum Charts for Monitoring Process Dispersion

PubMed Central

Abujiya, Mu’azu Ramat; Riaz, Muhammad; Lee, Muhammad Hisyam

2015-01-01

The cumulative sum (CUSUM) control chart is widely used in industry for the detection of small and moderate shifts in process location and dispersion. For efficient monitoring of process variability, we present several CUSUM control charts for monitoring changes in standard deviation of a normal process. The newly developed control charts based on well-structured sampling techniques - extreme ranked set sampling, extreme double ranked set sampling and double extreme ranked set sampling, have significantly enhanced CUSUM chart ability to detect a wide range of shifts in process variability. The relative performances of the proposed CUSUM scale charts are evaluated in terms of the average run length (ARL) and standard deviation of run length, for point shift in variability. Moreover, for overall performance, we implore the use of the average ratio ARL and average extra quadratic loss. A comparison of the proposed CUSUM control charts with the classical CUSUM R chart, the classical CUSUM S chart, the fast initial response (FIR) CUSUM R chart, the FIR CUSUM S chart, the ranked set sampling (RSS) based CUSUM R chart and the RSS based CUSUM S chart, among others, are presented. An illustrative example using real dataset is given to demonstrate the practicability of the application of the proposed schemes. PMID:25901356

Characterizations of additive manufactured porous titanium implants.

PubMed

Basalah, Ahmad; Shanjani, Yaser; Esmaeili, Shahrzad; Toyserkani, Ehsan

2012-10-01

This article describes physical, chemical, and mechanical characterizations of porous titanium implants made by an additive manufacturing method to gain insight into the correlation of process parameters and final physical properties of implants used in orthopedics. For the manufacturing chain, the powder metallurgy technology was combined with the additive manufacturing to fabricate the porous structure from the pure tanium powder. A 3D printing machine was employed in this study to produce porous bar samples. A number of physical parameters such as titanium powder size, polyvinyl alcohol (PVA) amount, sintering temperature and time were investigated to control the mechanical properties and porosity of the structures. The produced samples were characterized through porosity and shrinkage measurements, mechanical compression test and scanning electron microscopy (SEM). The results showed a level of porosity in the samples in the range of 31-43%, which is within the range of the porosity of the cancelluous bone and approaches the range of the porosity of the cortical bone. The results of the mechanical test showed that the compressive strength is in the wide range of 56-509 MPa implying the effect of the process parameters on the mechanical strengths. This technique of manufacturing of Ti porous structures demonstrated a low level of shrinkage with the shrinkage percentage ranging from 1.5 to 5%. Copyright © 2012 Wiley Periodicals, Inc.

Characterizing porosity of selected Early Palaeozoic shales from the Baltic Basin: organic petrology, gas adsorption and WIP and KIP approach.

NASA Astrophysics Data System (ADS)

Słomski, Piotr; Mastalerz, Maria; Szczepański, Jacek; Derkowski, Arkadiusz; Topór, Tomasz

2017-04-01

The porosity in the selected Ordovician and Silurian mudstones from the Baltic Basin collected from three wells (W1, M1, B1 and O3) was examined in a suite of 78 samples representing the Kopalino, Sasino, Prabuty, Pasłęk (including Jantar Member) and Pelplin Formations. Organic petrology, mineral composition along with N2 low-pressure adsorption (NLPA), water and kerosene immersion porosimetry (WIP and KIP, respectively) as well as image analysis techniques were used to determine pore volumes, pore sizes and pore-size distributions and to evaluate factors controlling porosity. The majority of the investigated samples represent argillaceous mudstones. Only a few samples from O3 and W1 are different lithologically and represent siliceous-argillaceous, calcareous, or calcareous-argillicaous mudstones. The samples are characterized by total organic carbon (TOC) content ranging from 0.13 to 7.20 wt. % and vitrinite reflectance (Ro) ranging from 1.02 to 1.22%, indicating late mature rocks within condensate - wet gas window. Total porosity measured using WIP is in the range from 4.6 % to 10 %, while KIP gave values from 1.5 % to 8.9 %. NLPA technique on the 75 µm size fraction revealed that mesopores area is in the range from 10.59 to 34.34 m2/g, while mesopores volume ranges from 0.024 to 0.062 cm3/g. Correlation between mesopores surface area and Ro is weak, but in general the surface area of mesopores is the largest in the least mature samples. Moreover, as indicated by gas adsorption data, both pores greater than 30 nm and smaller than 4 nm are important contributors to the total mesoporess surface area. In general, rather weak correlation between different mudstone constituents (including kerogen types) and porosity measured by means of various techniques (WIP, KIP and NLPA) reveal that there is no single factor controlling porosity in the investigated suite of samples. This conclusion is also confirmed by image analysis performed on large-scale high-resolution BSE images for selected representative samples. However, for mesopores, the dominant contribution comes from organic matter for the Jantar, Prabuty and Sasino Formations, as indicated by NLPA technique. Furthermore, importance of clay minerals for macropore volume is indicated by WIP and KIP technique. Acknowledgments: the study was supported from grant SHALESEQ (No PL12-0109) and SHALEMECH (No BG2/ShaleMech/14) funded by the National Centre for Research and Development.

Longitudinal Trajectories of Metabolic Control across Adolescence: Associations with Parental Involvement, Adolescents’ Psychosocial Maturity, and Health Care Utilization

PubMed Central

King, Pamela S.; Berg, Cynthia A.; Butner, Jonathan; Drew, Linda M.; Foster, Carol; Donaldson, David; Murray, Mary; Swinyard, Michael; Wiebe, Deborah J.

2012-01-01

Purpose To predict trajectories of metabolic control across adolescence from parental involvement and adolescent psychosocial maturity, and to link metabolic control trajectories to health care utilization. Methods 252 adolescents (M age at study initiation = 12.5, SD=1.5, range 10–14 years) with type 1 diabetes (54.4% female, 92.8% Caucasian, length of diagnosis M=4.7 years, SD=3.0, range 1–12) participated in a 2-year longitudinal study. Metabolic control was gathered from medical records every three months. Adolescents completed measures of self-reliance (functional autonomy and extreme peer orientation), self-control (self-control and externalizing behavior), and parental involvement in diabetes care (acceptance, monitoring, and frequency of help). At the end of the study, mothers reported health care utilization (diabetes-related emergency room visits and hospitalizations) over the past six months. Results Latent class growth analyses indicated two distinct trajectories of metabolic control across adolescence: moderate control with slight deterioration (92% of the sample; average HbA1c = 8.18%) and poor control with rapid deterioration (8% of the sample; average HbA1c of 12.09%). Adolescents with poor and rapidly deteriorating metabolic control reported lower paternal monitoring and frequency of help with diabetes management, lower functional autonomy, and lower self-control than others. Those with poor and rapidly deteriorating metabolic control were 6.4 times more likely to report diabetes-related emergency room visits, and 9.3 times more likely to report diabetes-related hospitalizations near the end of the study. Conclusions Parental involvement and adolescents’ psychosocial maturity predict patterns of deteriorating metabolic control across adolescence and could be targeted for intervention. PMID:22525113

Pesticide residue determination in vegetables from western China applying gas chromatography with mass spectrometry.

PubMed

Qin, Guofu; Zou, Keting; Li, Yongbo; Chen, Yan; He, Fengrui; Ding, Guirong

2016-09-01

In this study,an effort has been made to evaluate the pesticide residues in vegetables from western China. Fifty-one pesticides, including organophosphorus, organochlorine, carbamate and pyrethroid, were detected in 369 commonly used vegetables by GC-MS. Concentrations of organophosphorus pesticides were detected ranging from 0.0008 to 18.8200 mg/kg, among which organophosphorus pesticide concentrations exceeded their maximum residue levels (MRLs) in five samples. Carbamate and organochlorine pesticides were determined to have concentrations in the range of 0.0012-0.7928 mg/kg. The residual concentrations of carbamate pesticides in six samples and organochlorine pesticides in four samples exceeded their MRLs. The residual concentrations of five pyrethroid pesticides were within the range of 0.0016-6.0827 mg/kg and the pyrethroid residues in two samples exceeded their MRLs. The results revealed that pesticide residues in 70.73% of the vegetables samples were not detected, while in the rest of vegetables there were one or more pesticide residues and some even exceeded their MRLs, which would threaten the health of consumers. Our work provides significant information for the food safety regulations to control the excessive use of some pesticides on those kinds of vegetables from western China. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

40 CFR 192.20 - Guidance for implementation.

Code of Federal Regulations, 2012 CFR

2012-07-01

... to locations likely to contain residual radioactive materials. These surveys should be designed to... types of field and laboratory instruments in conjunction with reasonable survey and sampling procedures... decide that a control system design will satisfy the standard. The numerical range provided in the...

40 CFR 192.20 - Guidance for implementation.

Code of Federal Regulations, 2013 CFR

2013-07-01

... to locations likely to contain residual radioactive materials. These surveys should be designed to... types of field and laboratory instruments in conjunction with reasonable survey and sampling procedures... decide that a control system design will satisfy the standard. The numerical range provided in the...

Selective separation of iron from uranium in quantitative determination of traces of uranium by alpha spectrometry in soil/sediment sample.

PubMed

Singhal, R K; Narayanan, Usha; Karpe, Rupali; Kumar, Ajay; Ranade, A; Ramachandran, V

2009-04-01

During this work, controlled redox potential methodology was adopted for the complete separation of traces of uranium from the host matrix of mixed hydroxide of Iron. Precipitates of Fe(+2) and Fe(+3) along with other transuranic elements were obtained from acid leached solution of soil by raising the pH to 9 with 14N ammonia solution. The concentration of the uranium observed in the soil samples was 200-600 ppb, whereas in sediment samples, the concentration range was 61-400 ppb.

Quantitative Analysis and Stability of the Rodenticide TETS ...

EPA Pesticide Factsheets

Journal Article The determination of the rodenticide tetramethylenedisulfotetramine (TETS) in drinking water is reportable through the use of automated sample preparation via solid phase extraction and detection using isotope dilution gas chromatography-mass spectrometry. The method was characterized over twenty-two analytical batches with quality control samples. Accuracies for low and high concentration quality control pools were 100 and 101%, respectively. The minimum reporting level (MRL) for TETS in this method is 0.50 ug/L. Five drinking waters representing a range of water quality parameters and disinfection practices were fortified with TETS at ten times the MRL and analyzed over a 28 day period to determine the stability of TETS in these waters. The amount of TETS measured in these samples averaged 100 ± 6% of the amount fortified suggesting that tap water samples may be held for up to 28 days prior to analysis.

Comparative Evaluation of Three Homogenization Methods for Isolating Middle East Respiratory Syndrome Coronavirus Nucleic Acids From Sputum Samples for Real-Time Reverse Transcription PCR.

PubMed

Sung, Heungsup; Yong, Dongeun; Ki, Chang Seok; Kim, Jae Seok; Seong, Moon Woo; Lee, Hyukmin; Kim, Mi Na

2016-09-01

Real-time reverse transcription PCR (rRT-PCR) of sputum samples is commonly used to diagnose Middle East respiratory syndrome coronavirus (MERS-CoV) infection. Owing to the difficulty of extracting RNA from sputum containing mucus, sputum homogenization is desirable prior to nucleic acid isolation. We determined optimal homogenization methods for isolating viral nucleic acids from sputum. We evaluated the following three sputum-homogenization methods: proteinase K and DNase I (PK-DNase) treatment, phosphate-buffered saline (PBS) treatment, and N-acetyl-L-cysteine and sodium citrate (NALC) treatment. Sputum samples were spiked with inactivated MERS-CoV culture isolates. RNA was extracted from pretreated, spiked samples using the easyMAG system (bioMérieux, France). Extracted RNAs were then subjected to rRT-PCR for MERS-CoV diagnosis (DiaPlex Q MERS-coronavirus, SolGent, Korea). While analyzing 15 spiked sputum samples prepared in technical duplicate, false-negative results were obtained with five (16.7%) and four samples (13.3%), respectively, by using the PBS and NALC methods. The range of threshold cycle (Ct) values observed when detecting upE in sputum samples was 31.1-35.4 with the PK-DNase method, 34.7-39.0 with the PBS method, and 33.9-38.6 with the NALC method. Compared with the control, which were prepared by adding a one-tenth volume of 1:1,000 diluted viral culture to PBS solution, the ranges of Ct values obtained by the PBS and NALC methods differed significantly from the mean control Ct of 33.2 (both P<0.0001). The PK-DNase method is suitable for homogenizing sputum samples prior to RNA extraction.

Comparative Evaluation of Three Homogenization Methods for Isolating Middle East Respiratory Syndrome Coronavirus Nucleic Acids From Sputum Samples for Real-Time Reverse Transcription PCR

PubMed Central

Yong, Dongeun; Ki, Chang-Seok; Kim, Jae-Seok; Seong, Moon-Woo; Lee, Hyukmin

2016-01-01

Background Real-time reverse transcription PCR (rRT-PCR) of sputum samples is commonly used to diagnose Middle East respiratory syndrome coronavirus (MERS-CoV) infection. Owing to the difficulty of extracting RNA from sputum containing mucus, sputum homogenization is desirable prior to nucleic acid isolation. We determined optimal homogenization methods for isolating viral nucleic acids from sputum. Methods We evaluated the following three sputum-homogenization methods: proteinase K and DNase I (PK-DNase) treatment, phosphate-buffered saline (PBS) treatment, and N-acetyl-L-cysteine and sodium citrate (NALC) treatment. Sputum samples were spiked with inactivated MERS-CoV culture isolates. RNA was extracted from pretreated, spiked samples using the easyMAG system (bioMérieux, France). Extracted RNAs were then subjected to rRT-PCR for MERS-CoV diagnosis (DiaPlex Q MERS-coronavirus, SolGent, Korea). Results While analyzing 15 spiked sputum samples prepared in technical duplicate, false-negative results were obtained with five (16.7%) and four samples (13.3%), respectively, by using the PBS and NALC methods. The range of threshold cycle (Ct) values observed when detecting upE in sputum samples was 31.1–35.4 with the PK-DNase method, 34.7–39.0 with the PBS method, and 33.9–38.6 with the NALC method. Compared with the control, which were prepared by adding a one-tenth volume of 1:1,000 diluted viral culture to PBS solution, the ranges of Ct values obtained by the PBS and NALC methods differed significantly from the mean control Ct of 33.2 (both P<0.0001). Conclusions The PK-DNase method is suitable for homogenizing sputum samples prior to RNA extraction. PMID:27374711

Investigating the Influence of Clay Mineralogy on Stream Bank Erodibility

NASA Astrophysics Data System (ADS)

Ambers, R. K.; Stine, M. B.

2005-12-01

Soil scientists concerned with erosion of agricultural fields and geotechnical engineers concerned with the mechanical behavior of soils under different conditions have both examined the role of clay mineralogy in controlling soil/sediment properties. Fluvial geomorphologists studying stream channel erosion and stability have focused more on the effects of particle-size distribution, vegetation and rooting. The clay mineralogy of bed and bank sediment has the potential to influence cohesiveness and erodibility, however. The goal of this study is to determine the influence of clay mineralogy on the erodibility of natural stream bank sediment, utilizing techniques drawn from pedology and soil mechanics. Bank samples were collected from eleven sites in small watersheds in central and western Virginia. To obtain sediment containing a range of different clay minerals, watersheds with different types of bedrock were chosen for sampling. Rock types included mafic to felsic metamorphic and igneous rocks, shale, sandstone, and limestone. Where stream bank materials were clearly stratified, different layers were sampled separately. X-ray diffraction of the clay-fraction of the sediment indicates the presence of kaolinite, illite, vermiculite, and mixed-layer clay minerals in various abundances in the different samples. Clay content is 9-46%, as determined by the hydrometer method, and textures range from silty clay and silt loam to clay loam and sandy loam. Organic mater contents range from 1-5% by the loss-on-ignition method. Bulk density of intact sediment samples averages 1.5 g/cc. Liquid limits range from 23-41 with one sample having a value of 65; plasticity indices range from 15-22. While these tests predict that the samples would show a range of mechanical behaviors, the channel morphology at the sampling sites was not strikingly different, all having steep cut banks eroded primarily by scour with no evidence of mass movement and most having a width/depth ratio around 4.5. The ASTM pinhole test for identifying dispersive clay soils is being adapted to measure erodibility of intact and remolded sediment samples in the laboratory to look for more subtle differences in behavior under erosive conditions. Factors such as the extent and method of sample compaction are being taken into account in order to standardize the method.

Determination of interstitial chloride in shales and consolidated rocks by a precision leaching technique

USGS Publications Warehouse

Manheim, Frank T.; Peck, E.E.; Lane, Candice M.

1985-01-01

The authors have devised a technique for determining chloride in interstitial water of consolidated rocks. Samples of rocks ranging from 5 to 10 g are crushed and sieved under controlled conditions and then ground with distilled water to submicron size in a closed mechanical mill. The chloride concentrations and total pore-water concentrations, obtained earlier from the same samples by low-temperature vacuum desiccation, are used to arrive at the 'original' pore-water chloride concentrations by a simple iteration procedure. Interstitial chlorinity results obtained from Cretaceous and Jurassic strata in the Gulf of Mexico coastal areas ranged from 20 to 100 g/kg Cl with reproducibility approaching plus or minus 1%.

Validation and determination of a reference interval for canine HbA1c using an immunoturbidimetric assay.

PubMed

Goemans, Anne F; Spence, Susanna J; Ramsey, Ian K

2017-06-01

Hemoglobin A1c (HbA1c) provides a reliable measure of glycemic control over 2-3 months in human diabetes mellitus. In dogs, presence of HbA1c has been demonstrated, but there are no validated commercial assays. The purpose of the study was to validate a commercially available automated immunoturbidimetric assay for canine HbA1c and determine an RI in a hospital population. The specificity of the assay was assessed by inducing glycosylation in vitro using isolated canine hemoglobin, repeatability by measuring canine samples 5 times in succession, long term inter-assay imprecision by measuring supplied control materials, stability using samples stored at 4°C over 5 days and -20°C over 8 weeks, linearity by mixing samples of known HbA1c in differing proportions, and the effect of anticoagulants with paired samples. An RI was determined using EDTA-anticoagulated blood samples from 60 nondiabetic hospitalized animals of various ages and breeds. Hemoglobin A1c was also measured in 10 diabetic dogs. The concentration of HbA1c increased proportionally with glucose concentration in vitro. For repeat measurements, the CV was 4.08% (range 1.16-6.10%). Samples were stable for 5 days at 4°C. The assay was linear within the assessed range. Heparin- and EDTA-anticoagulated blood provided comparable results. The RI for HbA1c was 9-18.5 mmol/mol. There was no apparent effect of age or breed on HbA1c. In diabetic dogs, HbA1c ranged from 14 to 48 mmol/mol. The assay provides a reliable method for canine HbA1c measurement with good analytic performance. © 2017 American Society for Veterinary Clinical Pathology.

Longitudinal effects of violent video games on aggression in Japan and the United States.

PubMed

Anderson, Craig A; Sakamoto, Akira; Gentile, Douglas A; Ihori, Nobuko; Shibuya, Akiko; Yukawa, Shintaro; Naito, Mayumi; Kobayashi, Kumiko

2008-11-01

Youth worldwide play violent video games many hours per week. Previous research suggests that such exposure can increase physical aggression. We tested whether high exposure to violent video games increases physical aggression over time in both high- (United States) and low- (Japan) violence cultures. We hypothesized that the amount of exposure to violent video games early in a school year would predict changes in physical aggressiveness assessed later in the school year, even after statistically controlling for gender and previous physical aggressiveness. In 3 independent samples, participants' video game habits and physically aggressive behavior tendencies were assessed at 2 points in time, separated by 3 to 6 months. One sample consisted of 181 Japanese junior high students ranging in age from 12 to 15 years. A second Japanese sample consisted of 1050 students ranging in age from 13 to 18 years. The third sample consisted of 364 United States 3rd-, 4th-, and 5th-graders ranging in age from 9 to 12 years. RESULTS. Habitual violent video game play early in the school year predicted later aggression, even after controlling for gender and previous aggressiveness in each sample. Those who played a lot of violent video games became relatively more physically aggressive. Multisample structure equation modeling revealed that this longitudinal effect was of a similar magnitude in the United States and Japan for similar-aged youth and was smaller (but still significant) in the sample that included older youth. These longitudinal results confirm earlier experimental and cross-sectional studies that had suggested that playing violent video games is a significant risk factor for later physically aggressive behavior and that this violent video game effect on youth generalizes across very different cultures. As a whole, the research strongly suggests reducing the exposure of youth to this risk factor.

Impulsivity, Mental Disorder, and Suicide in Rural China

PubMed Central

Lin, Lin; Zhang, Jie

2017-01-01

Aims The purpose of this study was to investigate the relationship among impulsivity, mental disorder, and suicide with a sample of rural young Chinese. Methods Subjects were 392 consecutively recruited male and female suicides aged 15–34 years and 416 community male and female controls of the same age range sampled in rural China. The case-control data were obtained using psychological autopsy method with structured and semi-structured instruments. Results Dysfunctional impulsivity was a significant risk factor regardless of mental disorder in rural China. Conclusions Dysfunctional impulsivity is a potential area for further study of suicidal behavior. The suicide prevention efforts in rural China may address impulsivity. PMID:25764273

Generalized assorted pixel camera: postcapture control of resolution, dynamic range, and spectrum.

PubMed

Yasuma, Fumihito; Mitsunaga, Tomoo; Iso, Daisuke; Nayar, Shree K

2010-09-01

We propose the concept of a generalized assorted pixel (GAP) camera, which enables the user to capture a single image of a scene and, after the fact, control the tradeoff between spatial resolution, dynamic range and spectral detail. The GAP camera uses a complex array (or mosaic) of color filters. A major problem with using such an array is that the captured image is severely under-sampled for at least some of the filter types. This leads to reconstructed images with strong aliasing. We make four contributions in this paper: 1) we present a comprehensive optimization method to arrive at the spatial and spectral layout of the color filter array of a GAP camera. 2) We develop a novel algorithm for reconstructing the under-sampled channels of the image while minimizing aliasing artifacts. 3) We demonstrate how the user can capture a single image and then control the tradeoff of spatial resolution to generate a variety of images, including monochrome, high dynamic range (HDR) monochrome, RGB, HDR RGB, and multispectral images. 4) Finally, the performance of our GAP camera has been verified using extensive simulations that use multispectral images of real world scenes. A large database of these multispectral images has been made available at http://www1.cs.columbia.edu/CAVE/projects/gap_camera/ for use by the research community.

The Impact of Biosampling Procedures on Molecular Data Interpretation*

PubMed Central

Sköld, Karl; Alm, Henrik; Scholz, Birger

2013-01-01

The separation between biological and technical variation without extensive use of technical replicates is often challenging, particularly in the context of different forms of protein and peptide modifications. Biosampling procedures in the research laboratory are easier to conduct within a shorter time frame and under controlled conditions as compared with clinical sampling, with the latter often having issues of reproducibility. But is the research laboratory biosampling really less variable? Biosampling introduces within minutes rapid tissue-specific changes in the cellular microenvironment, thus inducing a range of different pathways associated with cell survival. Biosampling involves hypoxia and, depending on the circumstances, hypothermia, circumstances for which there are evolutionarily conserved defense strategies in the range of species and also are relevant for the range of biomedical conditions. It remains unclear to what extent such adaptive processes are reflected in different biosampling procedures or how important they are for the definition of sample quality. Lately, an increasing number of comparative studies on different biosampling approaches, post-mortem effects and pre-sampling biological state, have investigated such immediate early biosampling effects. Commonalities between biosampling effects and a range of ischemia/reperfusion- and hypometabolism/anoxia-associated biological phenomena indicate that even small variations in post-sampling time intervals are likely to introduce a set of nonrandom and tissue-specific effects of experimental importance (both in vivo and in vitro). This review integrates the information provided by these comparative studies and discusses how an adaptive biological perspective in biosampling procedures may be relevant for sample quality issues. PMID:23382104

Internal state control of a dense sample of ultracold 23Na87Rb molecules

NASA Astrophysics Data System (ADS)

Ye, Xin; Guo, Mingyang; He, Junyu; Wang, Dajun; Quemener, Goulven; Gonzalez-Martinez, Maykel; Dulieu, Oliver

2017-04-01

We report the optimized production of ultracold 23Na87Rb molecules with completely controlled population distribution among internal states. Starting from a sample of 104 weakly bound Feshbach molecules, we achieved a hyperfine-structure-resolved STIRAP transfer to the ground state with an efficiency up to 95%. By tuning the frequency difference between the Raman lasers and applying an additional microwave signal, we realized the preparation of NaRb samples in different vibrational, rotational, and hyperfine levels. Based on this achievement, some results on molecular collisions with a range of possible loss channels will also be reported. This work was supported by the French ANR/Hong Kong RGC COPOMOL project (Grant No. A-CUHK403/13), the RGC General Research Fund (Grant No. CUHK14301815).

A state observer for using a slow camera as a sensor for fast control applications

NASA Astrophysics Data System (ADS)

Gahleitner, Reinhard; Schagerl, Martin

2013-03-01

This contribution concerns about a problem that often arises in vision based control, when a camera is used as a sensor for fast control applications, or more precisely, when the sample rate of the control loop is higher than the frame rate of the camera. In control applications for mechanical axes, e.g. in robotics or automated production, a camera and some image processing can be used as a sensor to detect positions or angles. The sample time in these applications is typically in the range of a few milliseconds or less and this demands the use of a camera with a high frame rate up to 1000 fps. The presented solution is a special state observer that can work with a slower and therefore cheaper camera to estimate the state variables at the higher sample rate of the control loop. To simplify the image processing for the determination of positions or angles and make it more robust, some LED markers are applied to the plant. Simulation and experimental results show that the concept can be used even if the plant is unstable like the inverted pendulum.

Evaluation of a multi-arm multi-stage Bayesian design for phase II drug selection trials - an example in hemato-oncology.

PubMed

Jacob, Louis; Uvarova, Maria; Boulet, Sandrine; Begaj, Inva; Chevret, Sylvie

2016-06-02

Multi-Arm Multi-Stage designs aim at comparing several new treatments to a common reference, in order to select or drop any treatment arm to move forward when such evidence already exists based on interim analyses. We redesigned a Bayesian adaptive design initially proposed for dose-finding, focusing our interest in the comparison of multiple experimental drugs to a control on a binary criterion measure. We redesigned a phase II clinical trial that randomly allocates patients across three (one control and two experimental) treatment arms to assess dropping decision rules. We were interested in dropping any arm due to futility, either based on historical control rate (first rule) or comparison across arms (second rule), and in stopping experimental arm due to its ability to reach a sufficient response rate (third rule), using the difference of response probabilities in Bayes binomial trials between the treated and control as a measure of treatment benefit. Simulations were then conducted to investigate the decision operating characteristics under a variety of plausible scenarios, as a function of the decision thresholds. Our findings suggest that one experimental treatment was less efficient than the control and could have been dropped from the trial based on a sample of approximately 20 instead of 40 patients. In the simulation study, stopping decisions were reached sooner for the first rule than for the second rule, with close mean estimates of response rates and small bias. According to the decision threshold, the mean sample size to detect the required 0.15 absolute benefit ranged from 63 to 70 (rule 3) with false negative rates of less than 2 % (rule 1) up to 6 % (rule 2). In contrast, detecting a 0.15 inferiority in response rates required a sample size ranging on average from 23 to 35 (rules 1 and 2, respectively) with a false positive rate ranging from 3.6 to 0.6 % (rule 3). Adaptive trial design is a good way to improve clinical trials. It allows removing ineffective drugs and reducing the trial sample size, while maintaining unbiased estimates. Decision thresholds can be set according to predefined fixed error decision rates. ClinicalTrials.gov Identifier: NCT01342692 .

Growth And Characterization Studies Of Advanced Infrared Heterostructures

DTIC Science & Technology

2015-06-30

controlled within 50 arc-seconds for all the samples. The three samples were then processed into deep-etched mesa -type photodiodes, by using standard...contact ultraviolet lithography and wet-chemical etching. The circular mesa -size ranged from 25 to 400 µm in diameter. A 200-nm-thick SiNx film...coating was applied on top of the mesa . Devices were mounted on ceramic leadless chip carriers, and then mounted in the cryostat to characterize their

Cultural differences in crewmembers and mission control personnel during two space station programs.

PubMed

Boyd, Jennifer E; Kanas, Nick A; Salnitskiy, Vyacheslav P; Gushin, Vadim I; Saylor, Stephanie A; Weiss, Daniel S; Marmar, Charles R

2009-06-01

Cultural differences among crewmembers and mission control personnel can affect long-duration space missions. We examine three cultural contrasts: national (American vs. Russian); occupational (crewmembers vs. mission control personnel); and organizational [Mir space station vs. International Space Station (ISS)]. The Mir sample included 5 American astronauts, 8 Russian cosmonauts, and 42 American and 16 Russian mission control personnel. The ISS sample included 8 astronauts, 9 cosmonauts, and 108 American and 20 Russian mission control personnel. Subjects responded to mood and group climate questions on a weekly basis. The ISS sample also completed a culture and language questionnaire. Crewmembers had higher scores on cultural sophistication than mission control personnel, especially American mission control. Cultural sophistication was not related to mood or social climate. Russian subjects reported greater language flexibility than Americans. Crewmembers reported better mood states than mission control, but both were in the healthy range. There were several Russian-American differences in social climate, with the most robust being higher work pressure among Americans. Russian-American social climate differences were also found in analyses of crew only. Analyses showed Mir-ISS differences in social climate among crew but not in the full sample. We found evidence for national, occupational, and organizational cultural differences. The findings from the Mir space station were essentially replicated on the ISS. Alterations to the ISS to make it a more user-friendly environment have still not resolved the issue of high levels of work pressure among the American crew.

Application of internal quality control to the analysis of quaternary ammonium compounds in surface and groundwater from Andalusia (Spain) by liquid chromatography with mass spectrometry.

PubMed

Vidal, J L Martínez; Vega, A Belmonte; López, F J Sánchez; Frenich, A Garrido

2004-10-01

A method has been developed for the simultaneous determination of paraquat (PQ), deiquat (DQ), chlormequat (CQ) and mepiquat (MQ) in water samples by liquid chromatography (LC) coupled with electrospray ionization mass spectrometry (MS). The LC separations of the target compounds, as well as their MS parameters, were optimized in order to improve selectivity and sensitivity. Separation was carried out in a Xterra C8 column, using as mobile phase methanol-heptafluorobutyric acid (HFBA) in isocratic mode. The molecular ion was selected for the quantitation in selected ion monitoring (SIM) mode. Off-line solid-phase extraction (SPE) was applied with silica cartridges in order to preconcentrate the compounds from waters. Detection limits were in the range 0.02-0.40 microg l(-1). Recovery range varied between 89 and 99.5% with precision values lower than 6%. The method has been applied successfully to the analysis of both surface and groundwater samples from agricultural areas of Andalusia (Spain), using well defined internal quality control (IQC) criteria. The results revealed the presence of deiquat and paraquat in some samples.

Generation Scotland: Donor DNA Databank; A control DNA resource.

PubMed

Kerr, Shona M; Liewald, David C M; Campbell, Archie; Taylor, Kerrie; Wild, Sarah H; Newby, David; Turner, Marc; Porteous, David J

2010-11-23

Many medical disorders of public health importance are complex diseases caused by multiple genetic, environmental and lifestyle factors. Recent technological advances have made it possible to analyse the genetic variants that predispose to complex diseases. Reliable detection of these variants requires genome-wide association studies in sufficiently large numbers of cases and controls. This approach is often hampered by difficulties in collecting appropriate control samples. The Generation Scotland: Donor DNA Databank (GS:3D) aims to help solve this problem by providing a resource of control DNA and plasma samples accessible for research. GS:3D participants were recruited from volunteer blood donors attending Scottish National Blood Transfusion Service (SNBTS) clinics across Scotland. All participants gave full written consent for GS:3D to take spare blood from their normal donation. Participants also supplied demographic data by completing a short questionnaire. Over five thousand complete sets of samples, data and consent forms were collected. DNA and plasma were extracted and stored. The data and samples were unlinked from their original SNBTS identifier number. The plasma, DNA and demographic data are available for research. New data obtained from analysis of the resource will be fed back to GS:3D and will be made available to other researchers as appropriate. Recruitment of blood donors is an efficient and cost-effective way of collecting thousands of control samples. Because the collection is large, subsets of controls can be selected, based on age range, gender, and ethnic or geographic origin. The GS:3D resource should reduce time and expense for investigators who would otherwise have had to recruit their own controls.

The first 62 AGNs observed with SDSS-IV MaNGA - I. Their characterization and definition of a control sample

NASA Astrophysics Data System (ADS)

Rembold, Sandro B.; Shimoia, Jáderson S.; Storchi-Bergmann, Thaisa; Riffel, Rogério; Riffel, Rogemar A.; Mallmann, Nícolas D.; do Nascimento, Janaína C.; Moreira, Thales N.; Ilha, Gabriele S.; Machado, Alice D.; Cirolini, Rafael; da Costa, Luiz N.; Maia, Marcio A. G.; Santiago, Basílio X.; Schneider, Donald P.; Wylezalek, Dominika; Bizyaev, Dmitry; Pan, Kaike; Müller-Sánchez, Francisco

2017-12-01

We report the characterization of the first 62 Mapping Nearby Galaxies at the Apache Point Observatory active galactic nuclei (AGNs) hosts and the definition of a control sample of non-active galaxies. This control sample was selected in order to match the AGN hosts in terms of stellar mass, redshift, visual morphology and inclination. The stellar masses are in the range 9.4

Control strategies for planetary rover motion and manipulator control

NASA Technical Reports Server (NTRS)

Trautwein, W.

1973-01-01

An unusual insect-like vehicle designed for planetary surface exploration is made the occasion for a discussion of control concepts in path selection, hazard detection, obstacle negotiation, and soil sampling. A control scheme which actively articulates the pitching motion between a single-loop front module and a dual loop rear module leads to near optimal behavior in soft soil; at the same time the vehicle's front module acts as a reliable tactile forward probe with a detection range much longer than the stopping distance. Some optimal control strategies are discussed, and the photos of a working scale model are displayed.

Controlling of dielectrical properties of hydroxyapatite by ethylenediamine tetraacetic acid (EDTA) for bone healing applications

NASA Astrophysics Data System (ADS)

Kaygili, Omer; Ates, Tankut; Keser, Serhat; Al-Ghamdi, Ahmed A.; Yakuphanoglu, Fahrettin

2014-08-01

The hydroxyapatite (HAp) samples in the presence of various amounts of ethylenediamine tetraacetic acid (EDTA) were prepared by sol-gel method. The effects of EDTA on the crystallinity, phase structure, chemical, micro-structural and dielectric properties of HAp samples were investigated. With the addition of EDTA, the average crystallite size of the HAp samples is gradually decreased from 30 to 22 nm and the crystallinity is in the range of 65-71%. The values of the lattice parameters (a and c) and volume of the unit cell are decreased by stages with the addition of EDTA. The dielectric parameters such as relative permittivity, dielectric loss and relaxation time are affected by the adding of EDTA. The alternating current conductivity of the as-synthesized hydroxyapatites increases with the increasing frequency and obeys the universal power law behavior. The HAp samples exhibit a non-Debye relaxation mechanism. The obtained results that the dielectrical parameters of the HAp sample can be controlled by EDTA.

Effect of soil texture and chemical properties on laboratory-generated dust emissions from SW North America

NASA Astrophysics Data System (ADS)

Mockford, T.; Zobeck, T. M.; Lee, J. A.; Gill, T. E.; Dominguez, M. A.; Peinado, P.

2012-12-01

Understanding the controls of mineral dust emissions and their particle size distributions during wind-erosion events is critical as dust particles play a significant impact in shaping the earth's climate. It has been suggested that emission rates and particle size distributions are independent of soil chemistry and soil texture. In this study, 45 samples of wind-erodible surface soils from the Southern High Plains and Chihuahuan Desert regions of Texas, New Mexico, Colorado and Chihuahua were analyzed by the Lubbock Dust Generation, Analysis and Sampling System (LDGASS) and a Beckman-Coulter particle multisizer. The LDGASS created dust emissions in a controlled laboratory setting using a rotating arm which allows particle collisions. The emitted dust was transferred to a chamber where particulate matter concentration was recorded using a DataRam and MiniVol filter and dust particle size distribution was recorded using a GRIMM particle analyzer. Particle size analysis was also determined from samples deposited on the Mini-Vol filters using a Beckman-Coulter particle multisizer. Soil textures of source samples ranged from sands and sandy loams to clays and silts. Initial results suggest that total dust emissions increased with increasing soil clay and silt content and decreased with increasing sand content. Particle size distribution analysis showed a similar relationship; soils with high silt content produced the widest range of dust particle sizes and the smallest dust particles. Sand grains seem to produce the largest dust particles. Chemical control of dust emissions by calcium carbonate content will also be discussed.

Controlled ice nucleation in cryopreservation--a review.

PubMed

Morris, G John; Acton, Elizabeth

2013-04-01

We review here for the first time, the literature on control of ice nucleation in cryopreservation. Water and aqueous solutions have a tendency to undercool before ice nucleation occurs. Control of ice nucleation has been recognised as a critical step in the cryopreservation of embryos and oocytes but is largely ignored for other cell types. We review the processes of ice nucleation and crystal growth in the solution around cells and tissues during cryopreservation with an emphasis on non IVF applications. The extent of undercooling that is encountered during the cooling of various cryocontainers is defined and the methods that have been employed to control the nucleation of ice are examined. The effects of controlled ice nucleation on the structure of the sample and the outcome of cryopreservation of a range of cell types and tissues are presented and the physical events which define the cellular response are discussed. Nucleation of ice is the most significant uncontrolled variable in conventional cryopreservation leading to sample to sample variation in cell recovery, viability and function and should be controlled to allow standardisation of cryopreservation protocols for cells for biobanking, cell based assays or clinical application. This intervention allows a way of increasing viability of cells and reducing variability between samples and should be included as standard operating procedures are developed. Copyright © 2012 Elsevier Inc. All rights reserved.

The first 62 AGN observed with SDSS-IV MaNGA - II: resolved stellar populations

NASA Astrophysics Data System (ADS)

Mallmann, Nícolas Dullius; Riffel, Rogério; Storchi-Bergmann, Thaisa; Barboza Rembold, Sandro; Riffel, Rogemar A.; Schimoia, Jaderson; da Costa, Luiz Nicolaci; Ávila-Reese, Vladimir; Sanchez, Sebastian F.; Machado, Alice D.; Cirolini, Rafael; Ilha, Gabriele S.; do Nascimento, Janaína C.

2018-05-01

We present spatially resolved stellar population age maps, average radial profiles and gradients for the first 62 Active Galactic Nuclei (AGN) observed with SDSS-IV MaNGA to study the effects of the active nuclei on the star formation history of the host galaxies. These results, derived using the STARLIGHT code, are compared with a control sample of non-active galaxies matching the properties of the AGN hosts. We find that the fraction of young stellar populations (SP) in high-luminosity AGN is higher in the inner (R≤0.5 Re) regions when compared with the control sample; low-luminosity AGN, on the other hand, present very similar fractions of young stars to the control sample hosts for the entire studied range (1 Re). The fraction of intermediate age SP of the AGN hosts increases outwards, with a clear enhancement when compared with the control sample. The inner region of the galaxies (AGN and control galaxies) presents a dominant old SP, whose fraction decreases outwards. We also compare our results (differences between AGN and control galaxies) for the early and late-type hosts and find no significant differences. In summary, our results suggest that the most luminous AGN seems to have been triggered by a recent supply of gas that has also triggered recent star formation (t ≤ 40 Myrs) in the central region.

United States planetary rover status: 1989

NASA Technical Reports Server (NTRS)

Pivirotto, Donna L. S.; Dias, William C.

1990-01-01

A spectrum of concepts for planetary rovers and rover missions, is covered. Rovers studied range from tiny micro rovers to large and highly automated vehicles capable of traveling hundreds of kilometers and performing complex tasks. Rover concepts are addressed both for the Moon and Mars, including a Lunar/Mars common rover capable of supporting either program with relatively small modifications. Mission requirements considered include both Science and Human Exploration. Studies include a range of autonomy in rovers, from interactive teleoperated systems to those requiring and onboard System Executive making very high level decisions. Both high and low technology rover options are addressed. Subsystems are described for a representative selection of these rovers, including: Mobility, Sample Acquisition, Science, Vehicle Control, Thermal Control, Local Navigation, Computation and Communications. System descriptions of rover concepts include diagrams, technology levels, system characteristics, and performance measurement in terms of distance covered, samples collected, and area surveyed for specific representative missions. Rover development schedules and costs are addressed for Lunar and Mars exploration initiatives.

Nanorobotic System iTRo for Controllable 1D Micro/nano Material Twisting Test.

PubMed

Lu, Haojian; Shang, Wanfeng; Wei, Xueyong; Yang, Zhan; Fukuda, Toshio; Shen, Yajing

2017-06-08

In-situ micro/nano characterization is an indispensable methodology for material research. However, the precise in-situ SEM twisting of 1D material with large range is still challenge for current techniques, mainly due to the testing device's large size and the misalignment between specimen and the rotation axis. Herein, we propose an in-situ twist test robot (iTRo) to address the above challenges and realize the precise in-situ SEM twisting test for the first time. Firstly, we developed the iTRo and designed a series of control strategies, including assembly error initialization, triple-image alignment (TIA) method for rotation axis alignment, deformation-based contact detection (DCD) method for sample assembly, and switch control for robots cooperation. After that, we chose three typical 1D material, i.e., magnetic microwire Fe 74 B 13 Si 11 C 2 , glass fiber, and human hair, for twisting test and characterized their properties. The results showed that our approach is able to align the sample to the twisting axis accurately, and it can provide large twisting range, heavy load and high controllability. This work fills the blank of current in-situ mechanical characterization methodologies, which is expected to give significant impact in the fundamental nanomaterial research and practical micro/nano characterization.

Heart rate variability (HRV) in adolescent females with anxiety disorders and major depressive disorder.

PubMed

Henje Blom, E; Olsson, E M; Serlachius, E; Ericson, M; Ingvar, M

2010-04-01

The aim of this study was to investigate heart rate variability (HRV) in a clinical sample of female adolescents with anxiety disorders (AD) and/or major depressive disorder (MDD) compared with healthy controls and to assess the effect of selective serotonin reuptake inhibitors (SSRI) on HRV. Heart rate variability was measured in adolescent female psychiatric patients with AD and/or MDD (n = 69), mean age 16.8 years (range: 14.5-18.4), from 13 out-patient clinics and in healthy controls (n = 65), mean age 16.5 years (range: 15.9-17.7). HRV was registered in the sitting position during 4 min with no interventions. Logarithmically transformed high frequency HRV (HF), low frequency HRV (LF) and standard deviation of inter beat intervals (SDNN) were lower in the clinical sample compared with the controls (Cohen's d for HF = 0.57, LF = 0.55, SDNN = 0.60). This was not explained by body mass index, blood pressure or physical activity. Medication with SSRI explained 15.5% of the total variance of HF, 3.0% of LF and 6.5% of SDNN. Adolescent female psychiatric patients with AD and/or MDD show reduced HRV compared with healthy controls. Medication with SSRI explained a part of this difference.

Reprint of: Effects of cold deformation, electron irradiation and extrusion on deuterium desorption behavior in Zr-1%Nb alloy

NASA Astrophysics Data System (ADS)

Morozov, O.; Mats, O.; Mats, V.; Zhurba, V.; Khaimovich, P.

2018-01-01

The present article introduces the data of analysis of ranges of ion-implanted deuterium desorption from Zr-1% Nb alloy. The samples studied underwent plastic deformation, low temperature extrusion and electron irradiation. Plastic rolling of the samples at temperature ∼300 K resulted in plastic deformation with the degree of ε = 3.9 and the formation of nanostructural state with the average grain size of d = 61 nm. The high degree of defectiveness is shown in thermodesorption spectrum as an additional area of the deuterium desorption in the temperature ranges 650-850 K. The further processing of the sample (that had undergone plastic deformation by plastic rolling) with electron irradiation resulted in the reduction of the average grain size (58 nm) and an increase in borders concentration. As a result the amount of deuterium desorpted increased in the temperature ranges 650-900 K. In case of Zr-1% Nb samples deformed by extrusion the extension of desorption area is observed towards the temperature reduction down to 420 K. The formation of the phase state of deuterium solid solution in zirconium was not observed. The structural state behavior is a control factor in the process of deuterium thermodesorption spectrum structure formation with a fixed implanted deuterium dose (hydrogen diagnostics). It appears as additional temperature ranges of deuterium desorption depending on the type, character and defect content.

Measurement of immature platelets with Abbott CD-Sapphire and Sysmex XE-5000 in haematology and oncology patients.

PubMed

Meintker, Lisa; Haimerl, Maria; Ringwald, Jürgen; Krause, Stefan W

2013-11-01

Measurement of immature platelets was introduced into routine diagnostics by Sysmex as immature platelet fraction (IPF) some years ago and recently by Abbott as reticulated platelet fraction (rPT). Here, we compare both methods. We evaluated the precision and agreement of these parameters between Sysmex XE-5000 and Abbott CD-Sapphire in three distinct thrombocytopaenic cohorts: 30 patients with beginning thrombocytopaenia and 64 patients with recovering platelets (PLT) after chemotherapy, 16 patients with immune thrombocytopaenia (ITP) or heparin-induced thrombocytopaenia type 2 (HIT) and 110 additional normal controls. Furthermore, we analysed, how IPF/rPT differed between these thrombocytopaenic cohorts and controls. Both analysers demonstrated acceptable overall precision (repeatability) of IPF/rPT with lower precision at low PLT counts. IPF/rPT artificially increased during storage of blood samples overnight. Inter-instrument comparison showed a moderate correlation (Pearson r²=0.38) and a systematic bias of 1.04 towards higher IPF-values with the XE-5000. IPF/rPT was highest in recovering thrombopoesis after chemotherapy and moderately increased in ITP/HIT. The normal range deduced from control samples was much narrower with CD-Sapphire (1.0%-3.8%, established here for the first time) in comparison to XE-5000 (0.8%-7.9%) leading to a smaller overlap of samples with increased PLT turnover and normal controls. IPF and rPT both give useful information on PLT turnover, although the two analysers only show a moderate inter-instrument correlation and have different reference ranges. A better separation of patient groups with high PLT turnover like ITP/HIT from normal controls is obtained by CD-Sapphire.

Using the Semiconductors Materials of InSb-ZnTe System in Sensors for Gas Control

NASA Astrophysics Data System (ADS)

Shubenkova, E. G.

2017-04-01

The samples of thin film semiconductor compounds InSb, ZnTe and solid solutions based on them were obtained by vapor deposition of components on a dielectric substrate in a vacuum, followed by annealing and their surface properties in CO, O2 and NH3 gas atmospheres were investigated. Identification of the samples was carried out by X-ray diffraction techniques. In the temperature range 253 ÷ 403 K and a pressure range of 1÷12 Pa the gas adsorption was measured by piezoelectric microbalance technique. In order to establish the basic regularities of processes flowing on samples surface in addition to the electrophisical were used Infrared and Raman spectroscopic measurements. The resulting addiction “surface property - composition” is extreme and have allowed to determine solid solution InSb0,95-ZnTe0,05 as the most sensitive to the presence of ammonia, selective and this sample exhibits a negligible oxidation of surface.

Bone marrow mesenchymal stem cell response to nano-structured oxidized and turned titanium surfaces.

PubMed

Annunziata, Marco; Oliva, Adriana; Buosciolo, Antonietta; Giordano, Michele; Guida, Agostino; Guida, Luigi

2012-06-01

The aim of this study was to analyse the topographic features of a novel nano-structured oxidized titanium implant surface and to evaluate its effect on the response of human bone marrow mesenchymal stem cells (BM-MSC) compared with a traditional turned surface. The 10 × 10 × 1 mm turned (control) and oxidized (test) titanium samples (P.H.I. s.r.l.) were examined by scanning electron microscopy (SEM) and atomic force microscopy (AFM) and characterized by height, spatial and hybrid roughness parameters at different dimensional ranges of analysis. Primary cultures of BM-MSC were seeded on titanium samples and cell morphology, adhesion, proliferation and osteogenic differentiation, in terms of alkaline phosphatase activity, osteocalcin synthesis and extracellular matrix mineralization, were evaluated. At SEM and AFM analyses turned samples were grooved, whereas oxidized surfaces showed a more complex micro- and nano-scaled texture, with higher values of roughness parameters. Cell adhesion and osteogenic parameters were greater on oxidized (P<0.05 at least) vs. turned surfaces, whereas the cell proliferation rate was similar on both samples. Although both control and test samples were in the range of average roughness proper of smooth surfaces, they exhibited significantly different topographic properties in terms of height, spatial and, mostly, of hybrid parameters. This different micro- and nano-structure resulted in an enhanced adhesion and differentiation of cells plated onto the oxidized surfaces. © 2011 John Wiley & Sons A/S.

Quality-Assurance Data for Routine Water Analyses by the U.S. Geological Survey Laboratory in Troy, New York--July 1999 through June 2001

USGS Publications Warehouse

Lincoln, Tricia A.; Horan-Ross, Debra A.; McHale, Michael R.; Lawrence, Gregory B.

2006-01-01

The laboratory for analysis of low-ionic-strength water at the U.S. Geological Survey (USGS) Water Science Center in Troy, N.Y., analyzes samples collected by USGS projects throughout the Northeast. The laboratory's quality-assurance program is based on internal and interlaboratory quality-assurance samples and quality-control procedures that were developed to ensure proper sample collection, processing, and analysis. The quality-assurance and quality-control data were stored in the laboratory's LabMaster data-management system, which provides efficient review, compilation, and plotting of data. This report presents and discusses results of quality-assurance and quality-control samples analyzed from July 1999 through June 2001. Results for the quality-control samples for 18 analytical procedures were evaluated for bias and precision. Control charts indicate that data for eight of the analytical procedures were occasionally biased for either high-concentration or low-concentration samples but were within control limits; these procedures were: acid-neutralizing capacity, total monomeric aluminum, total aluminum, calcium, chloride and nitrate (ion chromatography and colormetric method) and sulfate. The total aluminum and dissolved organic carbon procedures were biased throughout the analysis period for the high-concentration sample, but were within control limits. The calcium and specific conductance procedures were biased throughout the analysis period for the low-concentration sample, but were within control limits. The magnesium procedure was biased for the high-concentration and low concentration samples, but was within control limits. Results from the filter-blank and analytical-blank analyses indicate that the procedures for 14 of 15 analytes were within control limits, although the concentrations for blanks were occasionally outside the control limits. The data-quality objective was not met for dissolved organic carbon. Sampling and analysis precision are evaluated herein in terms of the coefficient of variation obtained for triplicate samples in the procedures for 17 of the 18 analytes. At least 90 percent of the samples met data-quality objectives for all analytes except ammonium (81 percent of samples met objectives), chloride (75 percent of samples met objectives), and sodium (86 percent of samples met objectives). Results of the USGS interlaboratory Standard Reference Sample (SRS) Project indicated good data quality over the time period, with most ratings for each sample in the good to excellent range. The P-sample (low-ionic-strength constituents) analysis had one satisfactory rating for the specific conductance procedure in one study. The T-sample (trace constituents) analysis had one satisfactory rating for the aluminum procedure in one study and one unsatisfactory rating for the sodium procedure in another. The remainder of the samples had good or excellent ratings for each study. Results of Environment Canada's National Water Research Institute (NWRI) program indicated that at least 89 percent of the samples met data-quality objectives for 10 of the 14 analytes; the exceptions were ammonium, total aluminum, dissolved organic carbon, and sodium. Results indicate a positive bias for the ammonium procedure in all studies. Data-quality objectives were not met in 50 percent of samples analyzed for total aluminum, 38 percent of samples analyzed for dissolved organic carbon, and 27 percent of samples analyzed for sodium. Results from blind reference-sample analyses indicated that data-quality objectives were met by at least 91 percent of the samples analyzed for calcium, chloride, fluoride, magnesium, pH, potassium, and sulfate. Data-quality objectives were met by 75 percent of the samples analyzed for sodium and 58 percent of the samples analyzed for specific conductance.

Control of Rydberg atom blockade by dc electric field orientation in a quasi-one-dimensional sample

NASA Astrophysics Data System (ADS)

Goncalves, Luís Felipe; Marcassa, Luis Gustavo

2017-04-01

Rydberg atoms posse a strong atom-atom interaction, which limits its density in an atomic sample. Such effect is known as Rydberg atom blockade. Here, we present a novel way to control such effect by direct orienting the induced atomic dipole moment using a dc external electrical field. To demonstrate it, we excite the 50S1 / 2 Rb atomic state in a quasi-one-dimensional sample held in a quasi-electrostatic trap. A pure nS state holds only van der Waals interaction at long range, but in the presence of an external electric field the state mixing leads to strong dipole-dipole interactions. We have measured the Rydberg atom population as a function of ground state atoms density for several angles between the electric field and the main axis of the unidimensional sample. The results indicate that the limit on the final Rydberg density can be controlled by electric field orientation. Besides, we have characterized the sample by using direct spatial ion imaging, demonstrating that it does behave as an unidimensional sample. This work was supported by Sao Paulo Research Foundation (FAPESP) Grants No. 2011/22309-8 and No. 2013/02816- 8, the U.S. Army Research Office Grant No. W911NF-15-1-0638 and CNPq.

Adaptive control of turbulence intensity is accelerated by frugal flow sampling.

PubMed

Quinn, Daniel B; van Halder, Yous; Lentink, David

2017-11-01

The aerodynamic performance of vehicles and animals, as well as the productivity of turbines and energy harvesters, depends on the turbulence intensity of the incoming flow. Previous studies have pointed at the potential benefits of active closed-loop turbulence control. However, it is unclear what the minimal sensory and algorithmic requirements are for realizing this control. Here we show that very low-bandwidth anemometers record sufficient information for an adaptive control algorithm to converge quickly. Our online Newton-Raphson algorithm tunes the turbulence in a recirculating wind tunnel by taking readings from an anemometer in the test section. After starting at 9% turbulence intensity, the algorithm converges on values ranging from 10% to 45% in less than 12 iterations within 1% accuracy. By down-sampling our measurements, we show that very-low-bandwidth anemometers record sufficient information for convergence. Furthermore, down-sampling accelerates convergence by smoothing gradients in turbulence intensity. Our results explain why low-bandwidth anemometers in engineering and mechanoreceptors in biology may be sufficient for adaptive control of turbulence intensity. Finally, our analysis suggests that, if certain turbulent eddy sizes are more important to control than others, frugal adaptive control schemes can be particularly computationally effective for improving performance. © 2017 The Author(s).

2169 steel waveform experiments.

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

Furnish, Michael David; Alexander, C. Scott; Reinhart, William Dodd

2012-11-01

In support of LLNL efforts to develop multiscale models of a variety of materials, we have performed a set of eight gas gun impact experiments on 2169 steel (21% Cr, 6% Ni, 9% Mn, balance predominantly Fe). These experiments provided carefully controlled shock, reshock and release velocimetry data, with initial shock stresses ranging from 10 to 50 GPa (particle velocities from 0.25 to 1.05 km/s). Both windowed and free-surface measurements were included in this experiment set to increase the utility of the data set, as were samples ranging in thickness from 1 to 5 mm. Target physical phenomena included themore » elastic/plastic transition (Hugoniot elastic limit), the Hugoniot, any phase transition phenomena, and the release path (windowed and free-surface). The Hugoniot was found to be nearly linear, with no indications of the Fe phase transition. Releases were non-hysteretic, and relatively consistent between 3- and 5-mmthick samples (the 3 mm samples giving slightly lower wavespeeds on release). Reshock tests with explosively welded impactors produced clean results; those with glue bonds showed transient releases prior to the arrival of the reshock, reducing their usefulness for deriving strength information. The free-surface samples, which were steps on a single piece of steel, showed lower wavespeeds for thin (1 mm) samples than for thicker (2 or 4 mm) samples. A configuration used for the last three shots allows release information to be determined from these free surface samples. The sample strength appears to increase with stress from ~1 GPa to ~ 3 GPa over this range, consistent with other recent work but about 40% above the Steinberg model.« less

A broadband microwave Corbino spectrometer at ³He temperatures and high magnetic fields.

PubMed

Liu, Wei; Pan, LiDong; Armitage, N P

2014-09-01

We present the technical details of a broadband microwave spectrometer for measuring the complex conductance of thin films covering the range from 50 MHz up to 16 GHz in the temperature range 300 mK-6 K and at applied magnetic fields up to 8 T. We measure the complex reflection from a sample terminating a coaxial transmission line and calibrate the signals with three standards with known reflection coefficients. Thermal isolation of the heat load from the inner conductor is accomplished by including a section of NbTi superconducting cable (transition temperature around 8-9 K) and hermetic seal glass bead adapters. This enables us to stabilize the base temperature of the sample stage at 300 mK. However, the inclusion of this superconducting cable complicates the calibration procedure. We document the effects of the superconducting cable on our calibration procedure and the effects of applied magnetic fields and how we control the temperature with great repeatability for each measurement. We have successfully extracted reliable data in this frequency, temperature, and field range for thin superconducting films and highly resistive graphene samples.

A broadband microwave Corbino spectrometer at 3He temperatures and high magnetic fields

NASA Astrophysics Data System (ADS)

Liu, Wei; Pan, LiDong; Armitage, N. P.

2014-09-01

We present the technical details of a broadband microwave spectrometer for measuring the complex conductance of thin films covering the range from 50 MHz up to 16 GHz in the temperature range 300 mK-6 K and at applied magnetic fields up to 8 T. We measure the complex reflection from a sample terminating a coaxial transmission line and calibrate the signals with three standards with known reflection coefficients. Thermal isolation of the heat load from the inner conductor is accomplished by including a section of NbTi superconducting cable (transition temperature around 8-9 K) and hermetic seal glass bead adapters. This enables us to stabilize the base temperature of the sample stage at 300 mK. However, the inclusion of this superconducting cable complicates the calibration procedure. We document the effects of the superconducting cable on our calibration procedure and the effects of applied magnetic fields and how we control the temperature with great repeatability for each measurement. We have successfully extracted reliable data in this frequency, temperature, and field range for thin superconducting films and highly resistive graphene samples.

Quantification of six herbicide metabolites in human urine.

PubMed

Norrgran, Jessica; Bravo, Roberto; Bishop, Amanda M; Restrepo, Paula; Whitehead, Ralph D; Needham, Larry L; Barr, Dana B

2006-01-18

We developed a sensitive, selective and precise method for measuring herbicide metabolites in human urine. Our method uses automated liquid delivery of internal standards and acetate buffer and a mixed polarity polymeric phase solid phase extraction of a 2 mL urine sample. The concentrated eluate is analyzed using high-performance liquid chromatography-tandem mass spectrometry. Isotope dilution calibration is used for quantification of all analytes. The limits of detection of our method range from 0.036 to 0.075 ng/mL. The within- and between-day variation in pooled quality control samples range from 2.5 to 9.0% and from 3.2 to 16%, respectively, for all analytes at concentrations ranging from 0.6 to 12 ng/mL. Precision was similar with samples fortified with 0.1 and 0.25 ng/mL that were analyzed in each run. We validated our selective method against a less selective method used previously in our laboratory by analyzing human specimens using both methods. The methods produced results that were in agreement, with no significant bias observed.

Computer-controlled high-resolution capacitance dilatometer/oven system: Design, instrumentation, and performance

NASA Astrophysics Data System (ADS)

Johansen, T. H.; Feder, J.; Jøssang, T.

1986-06-01

A fully automated apparatus has been designed for measurements of dilatation in solid samples under well-defined thermal conditions. The oven can be thermally stabilized to better than 0.1 mK over a temperature range of -60 to 150 °C using a two-stage control strategy. Coarse control is obtained by heat exchange with a circulating thermal fluid, whereas the fine regulation is based on a solid-state heat pump—a Peltier element, acting as heating and cooling source. The bidirectional action of the Peltier element permits the sample block to be controlled at the average temperature of the surroundings, thus making an essentially adiabatic system with a minimum of thermal gradients in the sample block. The dilatometer cell integrated in the oven assembly is of the parallel plate air capacitor type, and the apparatus has been successfully used with a sensitivity of 0.07 Å. Our system is well suited for measurements near structural phase transitions with a relative resolution of Δt=(T-Tc)/Tc=2×10-7 in temperature and ΔL/L=1×10-9 in strain.

Temperature Controller System for Gas Gun Targets

NASA Astrophysics Data System (ADS)

Bucholtz, S. M.; Gehr, R. J.; Rupp, T. D.; Sheffield, S. A.; Robbins, D. L.

2006-07-01

A temperature controller system capable of heating and cooling gas gun targets over the range -75°C to +120°C was designed and tested. The system uses cold nitrogen gas from a liquid nitrogen Dewar for cooling and compressed air for heating. Two gas flow heaters control the gas temperature for both heating and cooling. One heater controls the temperature of the target mounting plate and the other the temperature of a copper tubing coil surrounding the target. Each heater is separately adjustable, so the target material will achieve a uniform temperature throughout its volume. A magnetic gauge membrane with integrated thermocouples was developed to measure the internal temperature of the target. Using this system, multiple magnetic gauge shock experiments, including equation-of-state measurements and shock initiation of high explosives, can be performed over a range of initial temperatures. Successful heating and cooling tests were completed on Teflon samples.

Industrial-hygiene characterization of ethylene oxide exposures of hospital and nursing-home workers

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

Ringenburg, V.L.; Elliott, L.J.; Morelli-Schroth, P.

Industrial-hygiene surveys were conducted at 12 hospitals and one nursing home to determine possible employee exposure to ethylene oxide (EtO). Different types of exposure situations existed at each of the facilities as a result of various engineering controls, administrative controls and work practices. Sampling indicated that the time-weighted averages (TWAs) of exposure over periods of 36 to 724 minutes ranged from below the limit of detection to 6.7 parts per million (ppm). Personal short-term exposure levels covering 2 to 30 minutes ranged from less than the limit of detection to 103.2ppm. Factors found to be responsible for these higher-than-permissible levelsmore » of EtO exposure included improper installation or lack of engineering controls (such as improper placement of the sterilizing operations), unbalanced ventilation systems, and lack of administrative controls resulting in inappropriate work practices.« less

Evaluation of PCR electrospray-ionization mass spectrometry for rapid molecular diagnosis of bovine mastitis.

PubMed

Perreten, Vincent; Endimiani, Andrea; Thomann, Andreas; Wipf, Juliette R K; Rossano, Alexandra; Bodmer, Michèle; Raemy, Andreas; Sannes-Lowery, Kristin A; Ecker, David J; Sampath, Rangarajan; Bonomo, Robert A; Washington, Cicely

2013-06-01

Bovine mastitis, an inflammatory disease of the mammary gland, is one of the most costly diseases affecting the dairy industry. The treatment and prevention of this disease is linked heavily to the use of antibiotics in agriculture and early detection of the primary pathogen is essential to control the disease. Milk samples (n=67) from cows suffering from mastitis were analyzed for the presence of pathogens using PCR electrospray-ionization mass spectrometry (PCR/ESI-MS) and were compared with standard culture diagnostic methods. Concurrent identification of the primary mastitis pathogens was obtained for 64% of the tested milk samples, whereas divergent results were obtained for 27% of the samples. The PCR/ESI-MS failed to identify some of the primary pathogens in 18% of the samples, but identified other pathogens as well as microorganisms in samples that were negative by culture. The PCR/ESI-MS identified bacteria to the species level as well as yeasts and molds in samples that contained a mixed bacterial culture (9%). The sensitivity of the PCR/ESI-MS for the most common pathogens ranged from 57.1 to 100% and the specificity ranged from 69.8 to 100% using culture as gold standard. The PCR/ESI-MS also revealed the presence of the methicillin-resistant gene mecA in 16.2% of the milk samples, which correlated with the simultaneous detection of staphylococci including Staphylococcus aureus. We demonstrated that PCR/ESI-MS, a more rapid diagnostic platform compared with bacterial culture, has the significant potential to serve as an important screening method in the diagnosis of bovine clinical mastitis and has the capacity to be used in infection control programs for both subclinical and clinical disease. Copyright © 2013 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Ochratoxin A in raisins and currants: basic extraction procedure used in two small marketing surveys of the occurrence and control of the heterogeneity of the toxins in samples.

PubMed

Möller, T E; Nyberg, M

2003-11-01

A basic extraction procedure for analysis of ochratoxin A (OTA) in currants and raisins is described, as well as the occurrence of OTA and a control of heterogeneity of the toxin in samples bought for two small marketing surveys 1999/2000 and 2001/02. Most samples in the surveys were divided into two subsamples that were individually prepared as slurries and analysed separately. The limit of quantification for the method was estimated as 0.1 microg kg(-1) and recoveries of 85, 90 and 115% were achieved in recovery experiments at 10, 5 and 0.1 microg kg(-1), respectively. Of all 118 subsamples analysed in the surveys, 96 (84%) contained ochratoxin A at levels above the quantification level and five samples (4%) contained more than the European Community legislation of 10 microg kg(-1). The OTA concentrations found in the first survey were in the range < 0.1-19.0 microg kg(-1) with a median concentration of 0.9 microg kg(-1). In the 2001/02 study, the range was < 0.1-34.6 microg kg(-1) with a median of 0.2 microg kg(-1). Big differences were often achieved between individual subsamples of the original sample, which indicate a wide heterogeneous distribution of the toxin. Data from the repeatability test as well as recovery experiments from the same slurries showed that preparation of slurries as described here seemed to give a homogeneous and representative sample. The extraction with the basic sodium bicarbonate-methanol mixture used in the surveys gave similar or somewhat higher OTA values on some samples tested in a comparison with a weak phosphoric acid water-methanol extraction mixture.

Determination of Coenzyme Q10 Content in Raw Materials and Dietary Supplements by High-Performance Liquid Chromatography-UV: Collaborative Study

PubMed Central

Lunetta, Steven; Roman, Mark

2008-01-01

An international collaborative study was conducted of a high-performance liquid chromatographic (HPLC)-UV method for the determination of coenzyme Q10 (CoQ10, ubidecarenone) in raw materials and dietary supplements. Ten collaborating laboratories determined the total CoQ10 content in 8 blind duplicate samples. Sample materials included CoQ10 raw material and 4 finished product dietary supplements representing softgels, hardshell gelatin capsules, and chewable wafers. In addition, collaborating laboratories received a negative control and negative control spiked with CoQ10 at low and high levels to determine recovery. Materials were extracted with an acetonitrile–tetrahydrofuran–water mixture. Ferric chloride was added to the test solutions to ensure all CoQ10 was in the oxidized form. The HPLC analyses were performed on a C18 column using UV detection at 275 nm. Repeatability relative standard deviations (RSDr) ranged from 0.94 to 5.05%. Reproducibility relative standard deviations (RSDR) ranged from 3.08 to 17.1%, with HorRat values ranging from 1.26 to 5.17. Recoveries ranged from 74.0 to 115%. Based on these results, the method is recommended for Official First Action for determination of CoQ10 in raw materials and dietary supplement finished products containing CoQ10 at a concentration of >100 mg CoQ10/g test material. PMID:18727527

Determination of coenzyme Q10 content in raw materials and dietary supplements by high-performance liquid chromatography-UV: collaborative study.

PubMed

Lunetta, Steven; Roman, Mark

2008-01-01

An international collaborative study was conducted of a high-performance liquid chromatographic (HPLC)-UV method for the determination of coenzyme Q10 (CoQ10, ubidecarenone) in raw materials and dietary supplements. Ten collaborating laboratories determined the total CoQ10 content in 8 blind duplicate samples. Sample materials included CoQ10 raw material and 4 finished product dietary supplements representing softgels, hardshell gelatin capsules, and chewable wafers. In addition, collaborating laboratories received a negative control and negative control spiked with CoQ10 at low and high levels to determine recovery. Materials were extracted with an acetonitrile-tetrahydrofuran-water mixture. Ferric chloride was added to the test solutions to ensure all CoQ10 was in the oxidized form. The HPLC analyses were performed on a C18 column using UV detection at 275 nm. Repeatability relative standard deviations (RSDr) ranged from 0.94 to 5.05%. Reproducibility relative standard deviations (RSDR) ranged from 3.08 to 17.1%, with HorRat values ranging from 1.26 to 5.17. Recoveries ranged from 74.0 to 115%. Based on these results, the method is recommended for Official First Action for determination of CoQ10 in raw materials and dietary supplement finished products containing CoQ10 at a concentration of >100 mg CoQ10/g test material.

Determination of bisphenol A, 4-n-nonylphenol, and 4-tert-octylphenol by temperature-controlled ionic liquid dispersive liquid-phase microextraction combined with high performance liquid chromatography-fluorescence detector.

PubMed

Zhou, Qingxiang; Gao, Yuanyuan; Xie, Guohong

2011-09-15

Present study described a simple, sensitive, and viable method for the determination of bisphenol A, 4-n-nonylphenol and 4-tert-octylphenol in water samples using temperature-controlled ionic liquid dispersive liquid-phase microextraction coupled to high performance liquid chromatography-fluorescence detector. In this experiment, 1-octyl-3-methylimidazolium hexafluorophosphate ([C(8)MIM][PF(6)]) was used as the extraction solvent, and bisphenol A, 4-n-nonylphenol and 4-tert-octylphenol were selected as the model analytes. Parameters affecting the extraction efficiency such as the volume of [C(8)MIM][PF(6)], dissolving temperature, extraction time, sample pH, centrifuging time and salting-out effect have been investigated in detail. Under the optimized conditions, good linear relationship was found in the concentration range of 1.0-100 μg L(-1) for BPA, 1.5-150 μg L(-1) for 4-NP, and 3-300 μg L(-1) for 4-OP, respectively. Limits of detection (LOD, S/N=3) were in the range of 0.23-0.48 μg L(-1). Intra day and inter day precisions (RSDs, n=6) were in the range of 4.6-5.5% and 8.5-13.3%, respectively. This method has been also successfully applied to analyze the real water samples at two different spiked concentrations and excellent results were obtained. Copyright © 2011 Elsevier B.V. All rights reserved.

DESIGN OF A SIMPLE SLOW COOLING DEVICE FOR CRYOPRESERVATION OF SMALL BIOLOGICAL SAMPLES.

PubMed

de Paz, Leonardo Juan; Robert, Maria Celeste; Graf, Daniel Adolfo; Guibert, Edgardo Elvio; Rodriguez, Joaquin Valentin

2015-01-01

Slow cooling is a cryopreservation methodology where samples are cooled to its storage temperature at controlled cooling rates. Design, construction and evaluation of a simple and low cost device for slow cooling of small biological samples. The device was constructed based on Pye's freezer idea. A Dewar flask filled with liquid nitrogen was used as heat sink and a methanol bath containing the sample was cooled at constant rates using copper bars as heat conductor. Sample temperature may be lowered at controlled cooling rate (ranging from 0.4°C/min to 6.0°C/min) down to ~-60°C, where it could be conserved at lower temperatures. An example involving the cryopreservation of Neuro-2A cell line showed a marked influence of cooling rate over post preservation cell viability with optimal values between 2.6 and 4.6°C/min. The cooling device proved to be a valuable alternative to more expensive systems allowing the assessment of different cooling rates to evaluate the optimal condition for cryopreservation of such samples.

Evaluation program for secondary spacecraft cells

NASA Technical Reports Server (NTRS)

Harkness, J. D.

1978-01-01

The results of life cycle tests of secondary spacecraft cells are summarized. Cells consisted of seven sample classifications ranging from 3.0 to 20 ampere-hours, 1326 nlc nickel cadmium, 183 silver cadmium, and 125 silver zinc sealed cells. Variables examined include load, charge control, and temperature conditions.

Robust Learning Control Design for Quantum Unitary Transformations.

PubMed

Wu, Chengzhi; Qi, Bo; Chen, Chunlin; Dong, Daoyi

2017-12-01

Robust control design for quantum unitary transformations has been recognized as a fundamental and challenging task in the development of quantum information processing due to unavoidable decoherence or operational errors in the experimental implementation of quantum operations. In this paper, we extend the systematic methodology of sampling-based learning control (SLC) approach with a gradient flow algorithm for the design of robust quantum unitary transformations. The SLC approach first uses a "training" process to find an optimal control strategy robust against certain ranges of uncertainties. Then a number of randomly selected samples are tested and the performance is evaluated according to their average fidelity. The approach is applied to three typical examples of robust quantum transformation problems including robust quantum transformations in a three-level quantum system, in a superconducting quantum circuit, and in a spin chain system. Numerical results demonstrate the effectiveness of the SLC approach and show its potential applications in various implementation of quantum unitary transformations.

Occupational exposure to acrylamide in closed system production plants: air levels and biomonitoring.

PubMed

Moorman, William J; Reutman, Susan S; Shaw, Peter B; Blade, Leo Michael; Marlow, David; Vesper, Hubert; Clark, John C; Schrader, Steven M

2012-01-01

The aim of this study was to evaluate biomarkers of acrylamide exposure, including hemoglobin adducts and urinary metabolites in acrylamide production workers. Biomarkers are integrated measures of the internal dose, and it is total acrylamide dose from all routes and sources that may present health risks. Workers from three companies were studied. Workers potentially exposed to acrylamide monomer wore personal breathing-zone air samplers. Air samples and surface-wipe samples were collected and analyzed for acrylamide. General-area air samples were collected in chemical processing units and control rooms. Hemoglobin adducts were isolated from ethylenediamine teraacetic acid (EDTA)-whole blood, and adducts of acrylamide and glycidamide, at the N-terminal valines of hemoglobin, were cleaved from the protein chain by use of a modified Edman reaction. Full work-shift, personal breathing zone, and general-area air samples were collected and analyzed for particulate and acrylamide monomer vapor. The highest general-area concentration of acrylamide vapor was 350 μg/cm(3) in monomer production. Personal breathing zone and general-area concentrations of acrylamide vapor were found to be highest in monomer production operations, and lower levels were in the polymer production operations. Adduct levels varied widely among workers, with the highest in workers in the monomer and polymer production areas. The acrylamide adduct range was 15-1884 pmol/g; glycidamide adducts ranged from 17.8 to 1376 p/mol/g. The highest acrylamide and glycidamide adduct levels were found among monomer production process operators. The primary urinary metabolite N-acetyl-S-(2-carbamoylethyl) cysteine (NACEC) ranged from the limit of detection to 15.4 μg/ml. Correlation of workplace exposure and sentinel health effects is needed to determine and control safe levels of exposure for regulatory standards.

Analysis of explicit model predictive control for path-following control

PubMed Central

2018-01-01

In this paper, explicit Model Predictive Control(MPC) is employed for automated lane-keeping systems. MPC has been regarded as the key to handle such constrained systems. However, the massive computational complexity of MPC, which employs online optimization, has been a major drawback that limits the range of its target application to relatively small and/or slow problems. Explicit MPC can reduce this computational burden using a multi-parametric quadratic programming technique(mp-QP). The control objective is to derive an optimal front steering wheel angle at each sampling time so that autonomous vehicles travel along desired paths, including straight, circular, and clothoid parts, at high entry speeds. In terms of the design of the proposed controller, a method of choosing weighting matrices in an optimization problem and the range of horizons for path-following control are described through simulations. For the verification of the proposed controller, simulation results obtained using other control methods such as MPC, Linear-Quadratic Regulator(LQR), and driver model are employed, and CarSim, which reflects the features of a vehicle more realistically than MATLAB/Simulink, is used for reliable demonstration. PMID:29534080

Analysis of explicit model predictive control for path-following control.

PubMed

Lee, Junho; Chang, Hyuk-Jun

2018-01-01

In this paper, explicit Model Predictive Control(MPC) is employed for automated lane-keeping systems. MPC has been regarded as the key to handle such constrained systems. However, the massive computational complexity of MPC, which employs online optimization, has been a major drawback that limits the range of its target application to relatively small and/or slow problems. Explicit MPC can reduce this computational burden using a multi-parametric quadratic programming technique(mp-QP). The control objective is to derive an optimal front steering wheel angle at each sampling time so that autonomous vehicles travel along desired paths, including straight, circular, and clothoid parts, at high entry speeds. In terms of the design of the proposed controller, a method of choosing weighting matrices in an optimization problem and the range of horizons for path-following control are described through simulations. For the verification of the proposed controller, simulation results obtained using other control methods such as MPC, Linear-Quadratic Regulator(LQR), and driver model are employed, and CarSim, which reflects the features of a vehicle more realistically than MATLAB/Simulink, is used for reliable demonstration.

Vegetation responses to natural regulation of elk in Rocky Mountain National Park

USGS Publications Warehouse

Zeigenfuss, Linda C.; Singer, Francis J.; Bowden, David

1999-01-01

Some grazing-induced responses were detected. Grazing-resistant species such as sedges (native), timothy (exotic), and club mosses increased and the amount of bare ground increased on some grazed sites. However, the changes within this sampling program alone were not alarming. The amount of bare ground increase was minor (4%), and grass and shrub cover increased in the shrub plots. The inferential power ofthis sample design was limited to the study plots only. Other factors (climate change, succession) were not controlled for using fenced plots and the sensitivity ofthe methods and plots to detect change were limited. For example, the low number oftransects in willow was not adequate to monitor conditions on the entire winter range. Lacking controls, observed changes may have been due to other factors (climate trends, beaver dam abandonment, stream channel changes), not elk herbivory alone. We recommend using a new sampling design that would include controls, pretreatment data, random site selection, and much more replication.

'Mitominis': multiplex PCR analysis of reduced size amplicons for compound sequence analysis of the entire mtDNA control region in highly degraded samples.

PubMed

Eichmann, Cordula; Parson, Walther

2008-09-01

The traditional protocol for forensic mitochondrial DNA (mtDNA) analyses involves the amplification and sequencing of the two hypervariable segments HVS-I and HVS-II of the mtDNA control region. The primers usually span fragment sizes of 300-400 bp each region, which may result in weak or failed amplification in highly degraded samples. Here we introduce an improved and more stable approach using shortened amplicons in the fragment range between 144 and 237 bp. Ten such amplicons were required to produce overlapping fragments that cover the entire human mtDNA control region. These were co-amplified in two multiplex polymerase chain reactions and sequenced with the individual amplification primers. The primers were carefully selected to minimize binding on homoplasic and haplogroup-specific sites that would otherwise result in loss of amplification due to mis-priming. The multiplexes have successfully been applied to ancient and forensic samples such as bones and teeth that showed a high degree of degradation.

Responses of beaver (Castor canadensis Kuhl) to predator chemicals.

PubMed

Engelhart, A; Müller-Schwarze, D

1995-09-01

Free-ranging beaver (Castor canadensis) in two different beaver populations in New York State were exposed to predator chemicals to test feeding inhibition. Solvent extracts of feces were applied to stem sections of aspen, the preferred food tree of beavers, permitting smelling and tasting the samples. Predator odors were from wolf (Canis lupus), coyote (Canis latrans), dog (Canis familiaris), black bear (Ursus americanus), river otter (Lutra canadensis), lynx (Lynx canadensis), and African lion (Panthera leo). The experiment was repeated. The predator odors reduced feeding compared to untreated or solvent-treated controls. One population consumed 17.0% of the samples with predator odor and 27.0% of the controls in summer, and 48.4% and 60.0%, respectively, in autumn. The other population accepted 3.15% of the predator odor samples and 11.05% of the controls in summer. Coyote, lynx, and river otter odors had the strongest effects. Diesel oil and bitter-tasting neem extract had weaker effects. Predator odors are promising as feeding repellents for beaver.

Method of analysis at the U.S. Geological Survey California Water Science Center, Sacramento Laboratory - determination of haloacetic acid formation potential, method validation, and quality-control practices

USGS Publications Warehouse

Zazzi, Barbara C.; Crepeau, Kathryn L.; Fram, Miranda S.; Bergamaschi, Brian A.

2005-01-01

An analytical method for the determination of haloacetic acid formation potential of water samples has been developed by the U.S. Geological Survey California Water Science Center Sacramento Laboratory. The haloacetic acid formation potential is measured by dosing water samples with chlorine under specified conditions of pH, temperature, incubation time, darkness, and residual-free chlorine. The haloacetic acids formed are bromochloroacetic acid, bromodichloroacetic acid, dibromochloroacetic acid, dibromoacetic acid, dichloroacetic acid, monobromoacetic acid, monochloroacetic acid, tribromoacetic acid, and trichloroacetic acid. They are extracted, methylated, and then analyzed using a gas chromatograph equipped with an electron capture detector. Method validation experiments were performed to determine the method accuracy, precision, and detection limit for each of the compounds. Method detection limits for these nine haloacetic acids ranged from 0.11 to 0.45 microgram per liter. Quality-control practices include the use of blanks, quality-control samples, calibration verification standards, surrogate recovery, internal standard, matrix spikes, and duplicates.

The UK Biobank sample handling and storage validation studies.

PubMed

Peakman, Tim C; Elliott, Paul

2008-04-01

and aims UK Biobank is a large prospective study in the United Kingdom to investigate the role of genetic factors, environmental exposures and lifestyle in the causes of major diseases of late and middle age. It involves the collection of blood and urine from 500 000 individuals aged between 40 and 69 years. How the samples are collected, processed and stored will have a major impact on the future scientific usefulness of the UK Biobank resource. A series of validation studies was recommended to test the robustness of the draft sample handling and storage protocol. Samples of blood and urine were collected from 40 healthy volunteers and either processed immediately according to the protocol or maintained at specified temperatures (4 degrees C for all tubes with the exception of vacutainers containing acid citrate dextrose that were maintained at 18 degrees C) for 12, 24 or 36 h prior to processing. A further sample was maintained for 24 h at 4 degrees C, processed and the aliquots frozen at -80 degrees C for 20 days and then thawed under controlled conditions. The stability of the samples was compared for the different times in a wide variety of assays. The samples maintained at 4 degrees C were stable for at least 24 h after collection for a wide range of assays. Small but significant changes were observed in metabonomic studies in samples maintained at 4 degrees C for 36 h. There was no degradation of the samples for a range of biochemical assays after short-term freezing and thawing under controlled conditions. Whole blood maintained at 18 degrees C for 24 h in vacutainers containing acid citrate dextrose is suitable for viral immortalization techniques. The validation studies reported in this supplement provide justification for the sample handling and storage procedures adopted in the UK Biobank project.

Sequential derivatization of polar organic compounds in cloud water using O-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine hydrochloride, N,O-bis(trimethylsilyl)trifluoroacetamide, and gas-chromatography/mass spectrometry analysis.

PubMed

Sagona, Jessica A; Dukett, James E; Hawley, Harmonie A; Mazurek, Monica A

2014-10-03

Cloud water samples from Whiteface Mountain, NY were used to develop a combined sampling and gas chromatography-mass spectrometric (GCMS) protocol for evaluating the complex mixture of highly polar organic compounds (HPOC) present in this atmospheric medium. Specific HPOC of interest were mono- and di keto-acids which are thought to originate from photochemical reactions of volatile unsaturated hydrocarbons from biogenic and manmade emissions and be a major fraction of atmospheric carbon. To measure HPOC mixtures and the individual keto-acids in cloud water, samples first must be derivatized for clean elution and measurement, and second, have low overall background of the target species as validated by GCMS analysis of field and laboratory blanks. Here, we discuss a dual derivatization method with PFBHA and BSTFA which targets only organic compounds that contain functional groups reacting with both reagents. The method also reduced potential contamination by minimizing the amount of sample processing from the field through the GCMS analysis steps. Once derivatized only gas chromatographic separation and selected ion monitoring (SIM) are needed to identify and quantify the polar organic compounds of interest. Concentrations of the detected total keto-acids in individual cloud water samples ranged from 27.8 to 329.3ngmL(-1) (ppb). Method detection limits for the individual HPOC ranged from 0.17 to 4.99ngmL(-1) and the quantification limits for the compounds ranged from 0.57 to 16.64ngmL(-1). The keto-acids were compared to the total organic carbon (TOC) results for the cloud water samples with concentrations of 0.607-3.350mgL(-1) (ppm). GCMS analysis of all samples and blanks indicated good control of the entire collection and analysis steps. Selected ion monitoring by GCMS of target keto-acids was essential for screening the complex organic carbon mixtures present at low ppb levels in cloud water. It was critical for ensuring high levels of quality assurance and quality control and for the correct identification and quantification of key marker compounds. Copyright © 2014 Elsevier B.V. All rights reserved.

Comparison of Address-based Sampling and Random-digit Dialing Methods for Recruiting Young Men as Controls in a Case-Control Study of Testicular Cancer Susceptibility

PubMed Central

Clagett, Bartholt; Nathanson, Katherine L.; Ciosek, Stephanie L.; McDermoth, Monique; Vaughn, David J.; Mitra, Nandita; Weiss, Andrew; Martonik, Rachel; Kanetsky, Peter A.

2013-01-01

Random-digit dialing (RDD) using landline telephone numbers is the historical gold standard for control recruitment in population-based epidemiologic research. However, increasing cell-phone usage and diminishing response rates suggest that the effectiveness of RDD in recruiting a random sample of the general population, particularly for younger target populations, is decreasing. In this study, we compared landline RDD with alternative methods of control recruitment, including RDD using cell-phone numbers and address-based sampling (ABS), to recruit primarily white men aged 18–55 years into a study of testicular cancer susceptibility conducted in the Philadelphia, Pennsylvania, metropolitan area between 2009 and 2012. With few exceptions, eligible and enrolled controls recruited by means of RDD and ABS were similar with regard to characteristics for which data were collected on the screening survey. While we find ABS to be a comparably effective method of recruiting young males compared with landline RDD, we acknowledge the potential impact that selection bias may have had on our results because of poor overall response rates, which ranged from 11.4% for landline RDD to 1.7% for ABS. PMID:24008901

δ18O and δD of lake waters across the Coast Range and Cascades, central Oregon: Modern insights from hydrologically open lakes into the control of landscape on lake water composition in deep time

NASA Astrophysics Data System (ADS)

Finkelstein, D. B.; Curtin, T.

2016-12-01

Reconstructing the stable isotopic composition of paleolake water normally requires an assumption of paleotemperature. However, hydrologically open paleolakes with short water residence times may have recorded paleoprecipitation along topographic gradients that are independent of lake water temperature. To identify the environmental and geographic controls on the isotopic composition of lake water, we sampled 22 natural lakes and reservoirs along a longitudinal and elevation gradient from the Pacific Ocean up and over the Coast and Cascade Ranges of central Oregon to the High Lava Plains in 2013 and 2015. The transect spans lakes of different origins, 6 geomorphic regions and an elevation range of 2-1942 m absl. The Coast Range lakes are sand hosted whereas the remaining are bedrock (volcanic and sedimentary) hosted. The lakes are hydrologically open and dominated by meteoric recharge. The water residence time ranges from months to decades. Samples were analyzed for temperature, pH, and total dissolved solids (TDS) in the field, and alkalinity and major cations and anions and stable isotopes of D and O in the lab. The pH ranges from 7 to 9.8 and shows no systematic variation based on substrate type or elevation. The lakes are dilute (avg. TDS = 35.8 ppm) and have low alkalinties (18.9 mg/L CaCO3) except for those in the High Lava Plains (avg. TDS = 337 ppm, alk: 291.2 mg/L CaCO3). In the Coast Range, Na is the major cation on an equivalent basis, reflecting proximity to the ocean. The easternmost lakes within the Coast Range are dominated by Ca, reflecting different drainage basins and substrate type. Lakes in the Western and High Cascades are dominated by Ca. The dominant cation and stable isotopic analyses clearly differentiate waters from different geomorphic regions. The δ18O ranges from -5.7 to -9.3 ‰ (VSMOW), and δD ranges from -37.8 to -63.6 ‰ (VSMOW) in the Coast Range whereas the δ18O ranges from -9.7 to -12.1 ‰ (VSMOW) and δD ranges from -71.5 to -86.5‰ (VSMOW) in the Cascades. Stable isotopic differences between mountain ranges reflect distance from the ocean and increasing elevation. Stable isotopes of water show no correlation with air or lake water temperatures. Average annual precipitation and bedrock across this topographic gradient controls the major ions and stable isotopic composition of these lakes.

Introduction of a rapid, simple radioimmunoassay and quality control scheme for thyroxine.

PubMed Central

Nye, L; Hassan, M; Willmott, E; Landon, J

1976-01-01

A simple radioimmunoassay has been developed for service purposes to determine serum total thyroxine levels. Only three additions are required, of standard or sample, labelled thyroxine and antibody in polyethylene glycol. After 2 hours' incubation at room temperature the antibody-bound and free fractions are separated by centrifugation. Serum total thyroxine levels were measured in 195 euthyroid subjects and it was established that normal values lay within the range 57 to 155 nmol/1. Serial blood samples taken over a 24-hour period, from 11 subjects, indicated that there was no circadian rhythm so that samples for total thyroxine assay can be taken at any time of the day. Similar results were obtained using serum or plasma. Satisfactory results were obtained for three quality control sera when measured by seven different laboratories using this method. PMID:932232

Dynamic principle for ensemble control tools.

PubMed

Samoletov, A; Vasiev, B

2017-11-28

Dynamical equations describing physical systems in contact with a thermal bath are commonly extended by mathematical tools called "thermostats." These tools are designed for sampling ensembles in statistical mechanics. Here we propose a dynamic principle underlying a range of thermostats which is derived using fundamental laws of statistical physics and ensures invariance of the canonical measure. The principle covers both stochastic and deterministic thermostat schemes. Our method has a clear advantage over a range of proposed and widely used thermostat schemes that are based on formal mathematical reasoning. Following the derivation of the proposed principle, we show its generality and illustrate its applications including design of temperature control tools that differ from the Nosé-Hoover-Langevin scheme.

Effect of iodine on mercury concentrations in dental-unit wastewater.

PubMed

Stone, Mark E; Kuehne, John C; Cohen, Mark E; Talbott, Jonathan L; Scott, John W

2006-02-01

This study was undertaken to determine whether iodine used to control bacteria in dental unit waterlines could increase mercury concentrations in dental wastewater. The study was conducted in four parts. Part 1. Solutions containing iodine in concentrations ranging from zero (control) to 20 mg/L were mixed with ground and sieved dental amalgam and then allowed to equilibrate by settling. Cold vapor atomic absorption spectrometry was used to determine mercury levels in the settled supernatants at 24 h and at 7 days. Part 2. Deionized water was pumped through an iodine-releasing water-treatment cartridge, collected, and mixed with ground and sieved dental amalgam. Mercury levels in settled supernatants were measured at 24 h and at 7 days. Part 3. Iodine in water from two commercial iodine-releasing cartridges was measured using Inductively Couple Plasma Mass Spectrometry. Part 4. Baseline mercury levels in settled supernatants from wastewater collected from two dental chairs were compared to samples taken from chairs equipped with iodine-releasing cartridges. Part 1. A linear correlation between iodine and mercury concentration (r2=0.9167 and 0.9459, respectively, both P<0.001) was seen at both 24 h and 7 days. Part 2. Mean mercury levels in 24h samples were 3.0 times higher than the controls (0.2864 mg/L compared with 0.0939mg/L for the 24 h controls). Mean mercury levels in the 7-day samples were 5.9 times higher than the 7-day controls (0.2048 mg/L compared with 0.0348 mg/L for the 7-day controls). Part 3. The effluent from two iodine-releasing cartridges showed iodine concentrations averaging 3.2 mg/L (n=10, SD=0.8, range=2.5-4.6). Part 4. Data from the clinical study showed a statistically significant 2.5-fold increase in mercury levels with iodine-containing samples compared to baseline (0.0853 mg/L, n=18, SD=0.0441 and 0.0345 mg/L, n=18, SD=0.0145, respectively; P<0.001). Data suggest that iodine can increase concentrations of dissolved mercury in dental unit wastewater.

A temperature-controlled cell for X-ray study of liquid systems using a commercial DRON-UM1 diffractometer

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

Petrun`kin, S.P.; Garavina, E.V.; Trostin, V.N.

1995-02-01

A container (cell) and a temperature-control system have been designed enabling one to carry out x-ray diffraction study of liquid samples both at a fixed temperature and within a certain temperature range using a commercial DRON-UMl x-ray diffractometer. Special features of the cell and the materials used for it allow one to study both chemically inert and corrosive liquids.

Puget Sound sediment-trap data: 1980-1985. Data report

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

Paulson, A.J.; Baker, E.T.; Feely, R.A.

1991-12-01

In 1979, scientists at the Pacific Marine Environmental Laboratory began investigating the sources, transformation, transport and fate of pollutants in Puget Sound and its watershed under Sec. 202 of the Marine Protection, Research and Sanctuaries Act of 1971 (P.L. 92-532) which called in part for '...a comprehensive and continuing program of research with respect to the possible long range effects of pollution, overfishing, and man-induced changes of ocean ecosystems...' The effort was called the Long-Range Effects Research Program (L-RERP) after language in the Act and was later called the PMEL Marine Environmental Quality Program. The Long-Range Effect Research Program consistedmore » of (1) sampling dissolved and particulate constituents in the water column by bottle sampling, (2) sampling settling particles by sediment trap and (3) sampling sediments by grab, box, gravity and Kasten corers. In the Data Report, a variety of data from particles collected in 104 traps deployed on 34 moorings in open waters between 1980 and 1985 are presented. The text of the data report begins with the sampling and analytical methods with the accompanying quality control/quality assurance data. The text of the data sections are a summary of the available data and published literature in which the data is interpreted along with a catalogue of the data available in the Appendix (on microfiche located in the back pocket of the data report).« less

Shear wave anisotropy from aligned inclusions: ultrasonic frequency dependence of velocity and attenuation

NASA Astrophysics Data System (ADS)

de Figueiredo, J. J. S.; Schleicher, J.; Stewart, R. R.; Dayur, N.; Omoboya, B.; Wiley, R.; William, A.

2013-04-01

To understand their influence on elastic wave propagation, anisotropic cracked media have been widely investigated in many theoretical and experimental studies. In this work, we report on laboratory ultrasound measurements carried out to investigate the effect of source frequency on the elastic parameters (wave velocities and the Thomsen parameter γ) and shear wave attenuation) of fractured anisotropic media. Under controlled conditions, we prepared anisotropic model samples containing penny-shaped rubber inclusions in a solid epoxy resin matrix with crack densities ranging from 0 to 6.2 per cent. Two of the three cracked samples have 10 layers and one has 17 layers. The number of uniform rubber inclusions per layer ranges from 0 to 100. S-wave splitting measurements have shown that scattering effects are more prominent in samples where the seismic wavelength to crack aperture ratio ranges from 1.6 to 1.64 than in others where the ratio varied from 2.72 to 2.85. The sample with the largest cracks showed a magnitude of scattering attenuation three times higher compared with another sample that had small inclusions. Our S-wave ultrasound results demonstrate that elastic scattering, scattering and anelastic attenuation, velocity dispersion and crack size interfere directly in shear wave splitting in a source-frequency dependent manner, resulting in an increase of scattering attenuation and a reduction of shear wave anisotropy with increasing frequency.

The Use of Carcasses for the Analysis of Cetacean Population Genetic Structure: A Comparative Study in Two Dolphin Species

PubMed Central

Bilgmann, Kerstin; Möller, Luciana M.; Harcourt, Robert G.; Kemper, Catherine M.; Beheregaray, Luciano B.

2011-01-01

Advances in molecular techniques have enabled the study of genetic diversity and population structure in many different contexts. Studies that assess the genetic structure of cetacean populations often use biopsy samples from free-ranging individuals and tissue samples from stranded animals or individuals that became entangled in fishery or aquaculture equipment. This leads to the question of how representative the location of a stranded or entangled animal is with respect to its natural range, and whether similar results would be obtained when comparing carcass samples with samples from free-ranging individuals in studies of population structure. Here we use tissue samples from carcasses of dolphins that stranded or died as a result of bycatch in South Australia to investigate spatial population structure in two species: coastal bottlenose (Tursiops sp.) and short-beaked common dolphins (Delphinus delphis). We compare these results with those previously obtained from biopsy sampled free-ranging dolphins in the same area to test whether carcass samples yield similar patterns of genetic variability and population structure. Data from dolphin carcasses were gathered using seven microsatellite markers and a fragment of the mitochondrial DNA control region. Analyses based on carcass samples alone failed to detect genetic structure in Tursiops sp., a species previously shown to exhibit restricted dispersal and moderate genetic differentiation across a small spatial scale in this region. However, genetic structure was correctly inferred in D. delphis, a species previously shown to have reduced genetic structure over a similar geographic area. We propose that in the absence of corroborating data, and when population structure is assessed over relatively small spatial scales, the sole use of carcasses may lead to an underestimate of genetic differentiation. This can lead to a failure in identifying management units for conservation. Therefore, this risk should be carefully assessed when planning population genetic studies of cetaceans. PMID:21655285

Collecting a better water-quality sample: Reducing vertical stratification bias in open and closed channels

USGS Publications Warehouse

Selbig, William R.

2017-01-01

Collection of water-quality samples that accurately characterize average particle concentrations and distributions in channels can be complicated by large sources of variability. The U.S. Geological Survey (USGS) developed a fully automated Depth-Integrated Sample Arm (DISA) as a way to reduce bias and improve accuracy in water-quality concentration data. The DISA was designed to integrate with existing autosampler configurations commonly used for the collection of water-quality samples in vertical profile thereby providing a better representation of average suspended sediment and sediment-associated pollutant concentrations and distributions than traditional fixed-point samplers. In controlled laboratory experiments, known concentrations of suspended sediment ranging from 596 to 1,189 mg/L were injected into a 3 foot diameter closed channel (circular pipe) with regulated flows ranging from 1.4 to 27.8 ft3 /s. Median suspended sediment concentrations in water-quality samples collected using the DISA were within 7 percent of the known, injected value compared to 96 percent for traditional fixed-point samplers. Field evaluation of this technology in open channel fluvial systems showed median differences between paired DISA and fixed-point samples to be within 3 percent. The range of particle size measured in the open channel was generally that of clay and silt. Differences between the concentration and distribution measured between the two sampler configurations could potentially be much larger in open channels that transport larger particles, such as sand.

Determination of total carbohydrates in wine and wine-like beverages by HPLC with a refractive index detector: First Action 2013.12.

PubMed

Kupina, Steve; Roman, Mark

2014-01-01

An international collaborative study was conducted of an HPLC-refractive index (RI) detector method for the determination of the combined amounts of sugars, glycerol, organic acids, and phenolic compounds in wines and wine-like beverages. Nine collaborating laboratories representing major winery, contract laboratories, and government laboratories tested eight different materials as blind duplicates using the proposed method. Sample materials included red and white wines, port, wine cooler, and nonalcoholic wine. One material was a negative control, and one material was a reference material. Samples were either treated with an ion-exchange resin to remove interfering organic acids prior to analysis or left untreated to include organic acids and phenolics. Red wine samples were treated with polyvinylpolypyrrolidone to remove potential interferences from phenolics prior to analysis. The HPLC analyses were performed on a Bio-Rad Fast Acid Analysis Column using RI detection. Reproducibility (RSD(R)) for untreated samples (sugars + phenolics + organic acids) ranged from 6.6% for Titrivin AA4 reference material to 11.0% for dry red wine. RSD(R) for treated samples (sugars only) ranged from 6.8% for white zinfandel to 18.9% for dry white wine. RSD(R) for treated samples (sugars only) + glycerol ranged from 6.4% for white zinfandel to 19.8% for dry red wine. Based on these results, the method was adopted as Official First Action status for determination of total carbohydrates in wine and wine-like beverages.

Engineering Considerations for Hydroxide Treatment of Training Ranges

DTIC Science & Technology

2007-06-01

solutions were compared to the untreated controls. [14C] labeled samples were counted on a Packard Instruments liquid scin - tillation counter (Model...and the soil was removed to a scin - tillation vial. Unlabeled flasks had the soil and liquid analyzed for TOC and the liquid analyzed for anion content

40 CFR 91.413 - Exhaust sample procedure-gaseous components.

Code of Federal Regulations, 2011 CFR

2011-07-01

... that may occur between the pre and post checks is not specified. However, the difference between pre... drift nor the span drift between the pre-analysis and post-analysis checks on any range used may exceed... PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM MARINE SPARK-IGNITION ENGINES Gaseous Exhaust Test...

40 CFR 91.413 - Exhaust sample procedure-gaseous components.

Code of Federal Regulations, 2014 CFR

2014-07-01

... that may occur between the pre and post checks is not specified. However, the difference between pre... drift nor the span drift between the pre-analysis and post-analysis checks on any range used may exceed... PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM MARINE SPARK-IGNITION ENGINES Gaseous Exhaust Test...

40 CFR 91.413 - Exhaust sample procedure-gaseous components.

Code of Federal Regulations, 2010 CFR

2010-07-01

... that may occur between the pre and post checks is not specified. However, the difference between pre... drift nor the span drift between the pre-analysis and post-analysis checks on any range used may exceed... PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM MARINE SPARK-IGNITION ENGINES Gaseous Exhaust Test...

40 CFR 91.413 - Exhaust sample procedure-gaseous components.

Code of Federal Regulations, 2012 CFR

2012-07-01

... that may occur between the pre and post checks is not specified. However, the difference between pre... drift nor the span drift between the pre-analysis and post-analysis checks on any range used may exceed... PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM MARINE SPARK-IGNITION ENGINES Gaseous Exhaust Test...

40 CFR 91.413 - Exhaust sample procedure-gaseous components.

Code of Federal Regulations, 2013 CFR

2013-07-01

... that may occur between the pre and post checks is not specified. However, the difference between pre... drift nor the span drift between the pre-analysis and post-analysis checks on any range used may exceed... PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM MARINE SPARK-IGNITION ENGINES Gaseous Exhaust Test...

Measurement of Phenolic Environmental Estrogens in Women with Uterine Leiomyoma

PubMed Central

Shen, Yang; Xu, Qian; Ren, Mulan; Feng, Xu; Cai, Yunlang; Gao, Yongxing

2013-01-01

Objectives To investigate the effect of phenolic environmental estrogens on uterine leiomyoma from the perspective of clinical epidemiology. Methods Urine and blood samples were collected from Han women with uterine leiomyoma and women without uterine leiomyoma, living in Nanjing, China, between September 2011 and February 2013. A total of 156 urine samples and 214 blood samples were collected from the uterine leiomyoma group and 106 urine samples and 126 blood plasma samples from the control group. Bisphenol A (BPA), nonylphenol (NP) and octylphenol (OP) concentrations were determined by solid-phase extraction (SPE) coupled with liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). Results Phenolic environmental estrogens in the uterine leiomyoma and control groups were compared based on: gravida>3 and gravida ≤ 3. In participants with gravida>3, urine OP concentration was significantly (P<0.05) higher in the uterine leiomyoma group than in the control group. In participants with gravida ≤ 3, urine NP concentration was significantly (P<0.05) higher in the uterine leiomyoma group compared to controls. Despite obstetric history, urine BPA mean exposure concentration was significantly (P<0.05) different between uterine leiomyoma group and control group. The urine BPA concentration was not significantly (P>0.05) different between gravida>3 and gravida ≤ 3 patients. There was no significant (P>0.05) difference in plasma concentrations of BPA, OP and NP between the leiomyoma group and control group. Mean exposure concentration and range of distribution of BPA, OP and NP plasma concentration differed between the uterine leiomyoma and control group. Conclusion Exposure level of phenolic environmental estrogens in human was related with leiomyoma tumorigenesis. PMID:24255718

Effects of sample injection amount and time-of-flight mass spectrometric detection dynamic range on metabolome analysis by high-performance chemical isotope labeling LC-MS.

PubMed

Zhou, Ruokun; Li, Liang

2015-04-06

The effect of sample injection amount on metabolome analysis in a chemical isotope labeling (CIL) liquid chromatography-mass spectrometry (LC-MS) platform was investigated. The performance of time-of-flight (TOF) mass spectrometers with and without a high-dynamic-range (HD) detection system was compared in the analysis of (12)C2/(13)C2-dansyl labeled human urine samples. An average of 1635 ± 21 (n = 3) peak pairs or putative metabolites was detected using the HD-TOF-MS, compared to 1429 ± 37 peak pairs from a conventional or non-HD TOF-MS. In both instruments, signal saturation was observed. However, in the HD-TOF-MS, signal saturation was mainly caused by the ionization process, while in the non-HD TOF-MS, it was caused by the detection process. To extend the MS detection range in the non-HD TOF-MS, an automated switching from using (12)C to (13)C-natural abundance peaks for peak ratio calculation when the (12)C peaks are saturated has been implemented in IsoMS, a software tool for processing CIL LC-MS data. This work illustrates that injecting an optimal sample amount is important to maximize the metabolome coverage while avoiding the sample carryover problem often associated with over-injection. A TOF mass spectrometer with an enhanced detection dynamic range can also significantly increase the number of peak pairs detected. In chemical isotope labeling (CIL) LC-MS, relative metabolite quantification is done by measuring the peak ratio of a (13)C2-/(12)C2-labeled peak pair for a given metabolite present in two comparative samples. The dynamic range of peak ratio measurement does not need to be very large, as only subtle changes of metabolite concentrations are encountered in most metabolomic studies where relative metabolome quantification of different groups of samples is performed. However, the absolute concentrations of different metabolites can be very different, requiring a technique to provide a wide detection dynamic range to allow the detection of as many peak pairs as possible. In this work, we demonstrated that controlling the sample injection amount into LC-MS was critical to achieve the optimal detectability while avoiding sample carry-over problem. In addition, the use of a high-dynamic-range TOF system increased the number of peak pairs detected, compared to a conventional TOF system. We also investigated the ionization and detection saturation factors limiting the dynamic range of detection. This article is part of a Special Issue entitled: Protein dynamics in health and disease. Guest Editors: Pierre Thibault and Anne-Claude Gingras. Copyright © 2014 Elsevier B.V. All rights reserved.

A study of retention characteristics and quality control of nutraceuticals containing resveratrol and polydatin using fused-core column chromatography.

PubMed

Fibigr, Jakub; Šatínský, Dalibor; Solich, Petr

2016-02-20

A new high-performance liquid chromatography method using fused-core column for fast separation of resveratrol and polydatin has been developed and used for quality control of nutraceuticals with resveratrol and polydatin content. Retention characteristics (log k) were studied under different conditions on C-18, RP-Amide C-18, Phenyl-hexyl, Pentafluorophenyl (F5) and Cyano stationary phases for both compounds. The effect of the volume fraction of acetonitrile on a retention factors log k of resveratrol and polydatin were evaluated. The optimal separation conditions for resveratrol, polydatin and internal standard p-nitrophenol were found on the fused-core column Ascentis Express ES-Cyano (100×3.0mm), particle size 2.7μm, with mobile phase acetonitrile/water solution with 0.5% acetic acid pH 3 (20:80, v/v) at a flow rate of 1.0mL/min and at 60°C. The detection wavelength was set at 305nm. Under the optimal chromatographic conditions, good linearity with regression coefficients in the range (r=0.9992-0.9998; n=10) for both compounds was achieved. Commercial samples of nutraceuticals were extracted with methanol using ultrasound bath for 15min. A 5μL sample volume of the filtered solution was directly injected into the HPLC system. Accuracy of the method defined as a mean recovery was in the range 83.2-107.3% for both nutraceuticals. The intraday method precision was found satisfactory and relative standard deviations of sample analysis were in the range 0.8-4.7%. The developed method has shown high sample throughput during sample preparation process, modern separation approach, and short time (3min) of analysis. The results of study showed that the declared content of resveratrol and polydatin varied widely in different nutraceuticals according the producers (71.50-115.00% of declared content). Copyright © 2015 Elsevier B.V. All rights reserved.

Light scattering by ultrasonically-controlled small particles: system design, calibration, and measurement results

NASA Astrophysics Data System (ADS)

Kassamakov, Ivan; Maconi, Göran; Penttilä, Antti; Helander, Petteri; Gritsevich, Maria; Puranen, Tuomas; Salmi, Ari; Hæggström, Edward; Muinonen, Karri

2018-02-01

We present the design of a novel scatterometer for precise measurement of the angular Mueller matrix profile of a mm- to µm-sized sample held in place by sound. The scatterometer comprises a tunable multimode Argon-krypton laser (with possibility to set 1 of the 12 wavelengths in visible range), linear polarizers, a reference photomultiplier tube (PMT) for monitoring the beam intensity, and a micro-PMT module mounted radially towards the sample at an adjustable radius. The measurement angle is controlled by a motor-driven rotation stage with an accuracy of 15'. The system is fully automated using LabVIEW, including the FPGA-based data acquisition and the instrument's user interface. The calibration protocol ensures accurate measurements by using a control sphere sample (diameter 3 mm, refractive index of 1.5) fixed first on a static holder followed by accurate multi-wavelength measurements of the same sample levitated ultrasonically. To demonstrate performance of the scatterometer, we conducted detailed measurements of light scattered by a particle derived from the Chelyabinsk meteorite, as well as planetary analogue materials. The measurements are the first of this kind, since they are obtained using controlled spectral angular scattering including linear polarization effects, for arbitrary shaped objects. Thus, our novel approach permits a non-destructive, disturbance-free measurement with control of the orientation and location of the scattering object.

Effect of Partial Replacement of Wheat Flour with High Quality Cassava Flour on the Chemical Composition, Antioxidant Activity, Sensory Quality, and Microbial Quality of Bread

PubMed Central

Eleazu, Chinedum; Eleazu, Kate; Aniedu, Chinyere; Amajor, John; Ikpeama, Ahamefula; Ebenzer, Ike

2014-01-01

In the current study, wheat flour was mixed with high quality cassava flour (HQCF) in several ratios: 90:10, 80:20, 70:30, and 60:40, and used to prepare 10%, 20%, 30%, and 40% National Root Crops Research Institute (NRCRI) cassava bread, respectively. 100% wheat bread was prepared as a control (100% wheat bread). Five bread samples were prepared per group. Antioxidant assays [i.e., 2,2-diphenyl- 1-picrylhydrazyl radical (DPPH) scavenging assay, reducing power assay] revealed that the bread samples had considerable antioxidant capacities. Substitution of wheat flour with HQCF at various concentrations resulted in dose dependent decreases in the mineral and protein contents of the resulting bread samples. The crude fiber content of the bread samples was minimal, while the carbohydrate content of the bread samples ranged from 43.86% to 48.64%. A 20% substitution of wheat flour with HQCF yielded bread samples with a general acceptability that was comparable to that of 100% wheat bread. The mean bacteria counts of the bread samples ranged from 2.0×103 CFU/mL to 1.4×104 CFU/mL, while the fungal counts ranged from 0 CFU/mL to 3×103 CFU/mL. There was a positive correlation between the DPPH antioxidant activities and the reducing powers of the bread samples (R2=0.871) and a positive correlation between the DPPH antioxidant activities and the flavonoid contents of the bread samples (R2=0.487). The higher microbial load of the NRCRI cassava bread samples indicates that these bread samples may have a shorter shelf life than the 100% wheat bread. The significant positive correlation between total flavonoid content and reducing power (R2=0.750) suggests that the flavonoids present in the lipophilic fractions of the bread samples could be responsible for the reductive capacities of the bread samples. PMID:25054110

Evaluation of chromium, cobalt and manganese in biological samples (scalp hair, blood, and urine) of Pakistani viral hepatitis (A-E) patients and controls.

PubMed

Afridi, Hassan Imran; Kazi, Tasneem Gul; Kazi, Naveed; Naeemullah; Arain, Sadaf Sadia; Brahman, Kapil Dev; Wadhwa, Sham Kumar

2013-01-01

The aim of the present study was to compare the level of chromium (Cr), cobalt (Co), and manganese (Mn) in biological samples (blood, urine, and scalp hair) of patients suffering from different types of viral hepatitis (A, B, C, D, and E; n = 521) of both genders, ages ranging from 31 - 45 years. For comparative study, 255 age-matched control subjects of both genders residing in the same city were selected as referents. The digests of all biological samples were analysed for Cr, Co, and Mn by electrothermal atomic absorption spectrometry (ETAAS). The validity and accuracy of the methodology was checked by using certified reference materials (CRMs) and compared with those values obtained by conventional wet acid digestion method on same CRMs. The results of this study showed that the mean values of Cr, Co, and Mn were higher in blood and scalp hair samples of hepatitis patients than in age-matched control subjects. The urinary levels of these elements were found to be higher in the hepatitis patients than in the age-matched healthy controls (p <0.001). These results are consistent with literature-reported data, confirming that the overload of these trace elements can directly cause lipid peroxidation and eventually hepatic damage.

Comparison of folic acid levels in schizophrenic patients and control groups

NASA Astrophysics Data System (ADS)

Arthy, C. C.; Amin, M. M.; Effendy, E.

2018-03-01

Folic acid deficiency is a risk factor for schizophrenia through epidemiology, biochemistry and gene-related studies. Compared with healthy people, schizophrenic patients may have high homocysteine plasma values and homocysteine or low levels of folic acid, which seems to correlate with extrapyramidal motor symptoms caused by neuroleptic therapy and with symptoms of schizophrenia. In this present study, we focus on the difference of folic acid level between schizophrenic patient and control group. The study sample consisted of schizophrenic patients and 14 people in the control group and performed blood sampling to obtain the results of folic acid levels. The folic acid level in both groups was within normal range, but the schizophrenic patient group had lower mean folic acid values of 5.00 ng/ml (sb 1.66), compared with the control group with mean folic acid values of 10.75 ng/ml (sb 4.33). there was the group of the control group had a higher value of folic acid than the schizophrenic group.

Emotional control, styles of coping with stress and acceptance of illness among patients suffering from chronic somatic diseases.

PubMed

Janowski, Konrad; Kurpas, Donata; Kusz, Joanna; Mroczek, Bożena; Jedynak, Tomasz

2014-02-01

The purpose of this study was to analyse the associations of emotional control with sociodemographic and clinical variables in a sample of patients with a range of chronic somatic diseases. The relationships between emotional control, coping styles and adjustment to the disease were investigated. The sample consisted of 300 patients with the mean age of 54.60 ± 17.57 years. Courtauld Emotional Control Scale was used to measure the patients' tendency to suppress negative emotions, Coping Inventory for Stressful Situations was used to measure coping styles and Acceptance of Illness Scale was applied to determine adjustment to the disease. Patients with neurological conditions showed significantly lower suppression of anger. Levels of emotional control were found to be related to gender, age and educational level but not to the place of residence. Task-oriented style of coping with stress correlated positively with suppression of depression and anxiety, whereas acceptance of illness correlated negatively with suppression of anger. Levels of emotional control are only weakly related to the type of diagnosis; however, some clinical samples may show lower suppression of anger. Suppression of negative emotions is weakly related to adjustment indicators such as certain coping styles and acceptance of illness. Copyright © 2013 John Wiley & Sons, Ltd.

PIC microcontroller based external fast analog to digital converter to acquire wide-lined solid NMR spectra by BRUKER DRX and Avance-I spectrometers.

PubMed

Koczor, Bálint; Rohonczy, János

2015-01-01

Concerning many former liquid or hybrid liquid/solid NMR consoles, the built in Analog-to-Digital Converters (ADCs) are incapable of digitizing the fids at sampling rates in the MHz range. Regarding both strong anisotropic interactions in the solid state and wide chemical shift dispersion nuclei in solution phase such as (195)Pt, (119)Sn, (207)Pb etc., the spectrum range of interest might be in the MHz range. As determining the informative tensor components of anisotropic NMR interactions requires nonlinear fitting over the whole spectrum including the asymptotic baseline, it is prohibited by low sampling rates of the ADCs. Wide spectrum width is also useful in solution NMR, since windowing of wide chemical shift ranges is avoidable. We built an external analog to digital converter with 10 MHz maximal sampling rate, which can work simultaneously with the built in ADC of the spectrometer. The ADC was tested on both Bruker DRX and Avance-I NMR consoles. In addition to the analog channels it only requires three external digital lines of the NMR console. The ADC sends data to PC via USB. The whole process is controlled by software written in JAVA which is implemented under TopSpin. Copyright © 2015 Elsevier Inc. All rights reserved.

Wavefront Control Testbed (WCT) Experiment Results

NASA Technical Reports Server (NTRS)

Burns, Laura A.; Basinger, Scott A.; Campion, Scott D.; Faust, Jessica A.; Feinberg, Lee D.; Hayden, William L.; Lowman, Andrew E.; Ohara, Catherine M.; Petrone, Peter P., III

2004-01-01

The Wavefront Control Testbed (WCT) was created to develop and test wavefront sensing and control algorithms and software for the segmented James Webb Space Telescope (JWST). Last year, we changed the system configuration from three sparse aperture segments to a filled aperture with three pie shaped segments. With this upgrade we have performed experiments on fine phasing with line-of-sight and segment-to-segment jitter, dispersed fringe visibility and grism angle;. high dynamic range tilt sensing; coarse phasing with large aberrations, and sampled sub-aperture testing. This paper reviews the results of these experiments.

Gain-Compensating Circuit For NDE and Ultrasonics

NASA Technical Reports Server (NTRS)

Kushnick, Peter W.

1987-01-01

High-frequency gain-compensating circuit designed for general use in nondestructive evaluation and ultrasonic measurements. Controls gain of ultrasonic receiver as function of time to aid in measuring attenuation of samples with high losses; for example, human skin and graphite/epoxy composites. Features high signal-to-noise ratio, large signal bandwidth and large dynamic range. Control bandwidth of 5 MHz ensures accuracy of control signal. Currently being used for retrieval of more information from ultrasonic signals sent through composite materials that have high losses, and to measure skin-burn depth in humans.

Automated, colorimetric methods for determination of nitrate plus nitrite, nitrite, ammonium and orthophosphate ions in natural water samples

USGS Publications Warehouse

Antweiler, Ronald C.; Patton, Charles J.; Taylor, Howard E.

1996-01-01

The apparatus and methods used for the automatic, colorimetric determinations of dissolved nutrients (nitrate plus nitrite, nitrite, ammonium and orthophosphate) in natural waters are described. These techniques allow for the determination of nitrate plus nitrite for the concentration range 0.02 to 8 mg/L (milligrams per liter) as N (nitrogen); for nitrite, the range is 0.002 to 1.0 mg/L as N; for ammonium, the range is 0.006 to 2.0 mg/L as N; and for orthophosphate, the range is 0.002 to 1.0 mg/L as P (phosphorus). Data are presented that demonstrate the accuracy, precision and quality control of the methods.

Development of a Toolbox Using Chemical, Physical and Biological Technologies for Decontamination of Sediments to Support Strategic Army Response to Natural Disasters

DTIC Science & Technology

2006-11-01

disinfection) was tested using soil microcosms and respirometry to determine diesel range and total organic compound degradation. These tests were...grease) such as benzo(a)pyrene were detected above chronic (long term-measured in years) screening levels. Levels of diesel and oil range organics... bioremediation , and toxicity of liquid and solid samples. The Comput-OX 4R is a 4 reactor unit with no stirring modules or temperature controlled water bath

Anodic voltammetric behavior and determination of cefixime in pharmaceutical dosage forms and biological fluids.

PubMed

Golcu, Ayşegul; Dogan, Burcu; Ozkan, Sibel A

2005-10-15

The voltammetric behavior of cefixime was studied using cyclic, linear sweep, differential pulse and square wave voltammetric techniques. The oxidation of cefixime was irreversible and exhibited diffusion controlled process depending on pH. The oxidation mechanism was proposed and discussed. Different parameters were tested to optimize the conditions for the determination of cefixime. The dependence of current intensities and potentials on pH, concentration, scan rate, nature of the buffer was investigated. According to the linear relationship between the peak current and the concentration, differential pulse (DPV) and square wave (SWV) voltammetric methods for cefixime assay in pharmaceutical dosage forms and biological fluids were developed. For the determination of cefixime were proposed in acetate buffer at pH 4.5, which allows quantitation over the 6 x 10(-6)-2 x 10(-4)M range in supporting electrolyte and spiked serum sample; 8 x 10(-6)-2 x 10(-4)M range in urine sample; 6 x 10(-6)-1 x 10(-4)M range in breast milk samples for both techniques. The repeatability, reproducibility, precision and accuracy of the methods in all media were investigated. No electroactive interferences from the excipients and endogenous substances were found in the pharmaceutical dosage forms and in the biological samples, respectively.

Transition of carbon nanostructures in heptane diffusion flames

NASA Astrophysics Data System (ADS)

Hu, Wei-Chieh; Hou, Shuhn-Shyurng; Lin, Ta-Hui

2017-02-01

The flame synthesis has high potential in industrial production of carbon nanostructure (CNS). Unfortunately, the complexity of combustion chemistry leads to less controlling of synthesized products. In order to improve the understanding of the relation between flames and CNSs synthesized within, experiments were conducted through heptane flames in a stagnation-point liquid-pool system. The operating parameters for the synthesis include oxygen supply, sampling position, and sampling time. Two kinds of nanostructures were observed, carbon nanotube (CNT) and carbon nano-onion (CNO). CNTs were synthesized in a weaker flame near extinction. CNOs were synthesized in a more sooty flame. The average diameter of CNTs formed at oxygen concentration of 15% was in the range of 20-30 nm. For oxygen concentration of 17%, the average diameter of CNTs ranged from 24 to 27 nm, while that of CNOs was around 28 nm. For oxygen concentration of 19%, the average diameter of CNOs produced at the sampling position 0.5 mm below the flame front was about 57 nm, while the average diameters of CNOs formed at the sampling positions 1-2.5 mm below the flame front were in the range of 20-25 nm. A transition from CNT to CNO was observed by variation of sampling position in a flame. We found that the morphology of CNS is directly affected by the presence of soot layer due to the carbonaceous environment and the growth mechanisms of CNT and CNO. The sampling time can alter the yield of CNSs depending on the temperature of sampling position, but the morphology of products is not affected.

Preconcentration and Determination of Trace Vanadium(V) in Beverages by Combination of Ultrasound Assisted-cloud Point Extraction with Spectrophotometry.

PubMed

Kartal Temel, Nuket; Gürkan, Ramazan

2018-03-01

A novel ultrasound assisted-cloud point extraction method was developed for preconcentration and determination of V(V) in beverage samples. After complexation by pyrogallol in presence of safranin T at pH 6.0, V(V) ions as ternary complex are extracted into the micellar phase of Triton X-114. The complex was monitored at 533 nm by spectrophotometry. The matrix effect on the recovery of V(V) from the spiked samples at 50 μg L-1 was evaluated. In optimized conditions, the limits of detection and quantification of the method, respectively, was 0.58 and 1.93 μg L-1 in linear range of 2-500 μg L-1 with sensitivity enhancement and preconcentration factors of 47.7 and 40 for preconcentration from 15 mL of sample solution. The recoveries from spiked samples were in range of 93.8-103.2% with a relative standard deviation ranging from 2.6% to 4.1% (25, 100 and 250 μg L-1, n: 5). The accuracy was verified by analysis of two certified samples, and the results were in a good agreement with the certified values. The intra-day and inter-day precision were tested by reproducibility (as 3.3-3.4%) and repeatability (as 3.4-4.1%) analysis for five replicate measurements of V(V) in quality control samples spiked with 5, 10 and 15 μg L-1. Trace V(V) contents of the selected beverage samples by the developed method were successfully determined.

Meltable magnetic biocomposites for controlled release

NASA Astrophysics Data System (ADS)

Müller, R.; Zhou, M.; Dellith, A.; Liebert, T.; Heinze, T.

2017-06-01

New biocompatible composites with adjustable melting point in the range of 30-140 °C, consisting of magnetite nanoparticles embedded into a matrix of meltable dextran fatty acid ester are presented which can be softened under an induced alternating magnetic field (AMF). The chosen thermoplastic magnetic composites have a melting range close to human body temperature and can be easily shaped into disk or coating film under melting. The composite disks were loaded with green fluorescent protein (GFP) as a model protein. Controlled release of the protein was realized with high frequent alternating magnetic field of 20 kA/m at 400 kHz. These results showed that under an AMF the release of GFP from magnetic composite was accelerated compared to the control sample without exposure to AMF. Furthermore a texturing of particles in the polymer matrix by a static magnetic field was investigated.

Effect of Environmental and Behavioral Interventions on Pain Intensity in Preterm Infants for Heel Prick Blood Sampling in the Neonatal Intensive Care Unit.

PubMed

Baharlooei, Fatemeh; Marofi, Maryam; Abdeyazdan, Zahra

2017-01-01

Recent researches suggest that preterm infants understand pain and stress. Because of the wide range of effects of pain on infants, the present study was conducted on the effect of environmental and behavioral interventions on pain due to heel-prick blood sampling in preterm infants. A clinical trial was conducted among 32 infants with gestational age of 32-37 weeks in the intervention and control groups. The effects of noise reduction by earplugs, light reduction by blindfolds, reduction of nursing manipulation, and creation of intrauterine position for neonates, 30 minutes before taking blood samples until 30 minutes after it, were measured during the intervention stage. Data were collected using the Neonatal Infant Pain Scale (NIPS) in 5 stages (before intervention, 2 minutes before sampling, during the sampling, and 5 minutes and 30 minutes after the sampling). The data were analyzed using analysis of variance (ANOVA) and paired t -test in SPSS software. The paired t -test results showed no significant differences between the control and intervention stages in terms of pain scores at base time ( P = 0.42) and 2 minutes before sampling ( P = 0.12). However, at the sampling time ( P = 0.0), and 5 minutes ( P = 0.001) and 30 minutes after the sampling ( P = 0.001), mean pain score in the intervention stage was significantly less than that in the control stage. Based on the findings, environmental and behavioral interventions reduced pain and facilitated heel-prick blood sampling in preterm infants.

Locus of control and peer relationships among Caucasian, Hispanic, Asian, and African American adolescents.

PubMed

Kang, Hannah Soo; Chang, Kyle Edward; Chen, Chuansheng; Greenberger, Ellen

2015-01-01

Past research has shown that locus of control plays an important role in a wide range of behaviors, such as academic achievement and positive social behaviors. However, little is known about whether locus of control plays the same role in minority adolescents' peer relationships. The current study examined ethnic differences in the associations between locus of control and peer relationships in early adolescence using samples from the Early Childhood Longitudinal Study (ECLS-K: 5,612 Caucasian, 1,562 Hispanic, 507 Asian, and 908 African-American adolescents) and the National Education Longitudinal Study (NELS: 8,484 Caucasian, 1,604 Hispanic, and 860 Asian, and 1,228 African American adolescents). Gender was approximately evenly split in both samples. The results from the two datasets were highly consistent. Significant interactions between ethnicity and locus of control indicated that having a more internal locus of control was particularly important for Caucasian students' peer relationships (ECLS-K) and social status (NELS), but less so for Asian, Hispanic, and African American students. Our findings suggest that the role of locus of control in peer relationship is contingent upon culture.

Measurement of uterine natural killer cell percentage in the periimplantation endometrium from fertile women and women with recurrent reproductive failure: establishment of a reference range.

PubMed

Chen, Xiaoyan; Mariee, Najat; Jiang, Lingming; Liu, Yingyu; Wang, Chi Chiu; Li, Tin Chiu; Laird, Susan

2017-12-01

Uterine natural killer cells are the major leukocytes present in the periimplantation endometrium. Previous studies have found controversial differences in uterine natural killer cell percentage in women with recurrent reproductive failure compared with fertile controls. We sought to compare the uterine natural killer cell percentage in women with recurrent reproductive failure and fertile controls. This was a retrospective study carried out in university hospitals. A total of 215 women from 3 university centers participated in the study, including 97 women with recurrent miscarriage, 34 women with recurrent implantation failure, and 84 fertile controls. Endometrial biopsy samples were obtained precisely 7 days after luteinization hormone surge in a natural cycle. Endometrial sections were immunostained for CD56 and cell counting was performed by a standardized protocol. Results were expressed as percentage of positive uterine natural killer cell/total stromal cells. The median uterine natural killer cell percentage in Chinese ovulatory fertile controls in natural cycles was 2.5% (range 0.9-5.3%). Using 5th and 95th percentile to define the lower and upper limits of uterine natural killer cell percentage, the reference range was 1.2-4.5%. Overall, the groups with recurrent reproductive failure had significantly higher uterine natural killer cell percentage than the controls (recurrent miscarriage: median 3.2%, range 0.6-8.8%; recurrent implantation failure: median 3.1%, range 0.8-8.3%). However, there was a subset of both groups (recurrent miscarriage: 16/97; recurrent implantation failure: 6/34) that had lower uterine natural killer cell percentage compared to fertile controls. A reference range for uterine natural killer cell percentage in fertile women was established. Women with recurrent reproductive failure had uterine natural killer cell percentages both above and below the reference range. Copyright © 2017 Elsevier Inc. All rights reserved.

A multi-sensor study of the impact of ground-based glaciogenic seeding on clouds and precipitation over mountains in Wyoming. Part II: Seeding impact analysis

NASA Astrophysics Data System (ADS)

Pokharel, Binod; Geerts, Bart; Jing, Xiaoqin; Friedrich, Katja; Ikeda, Kyoko; Rasmussen, Roy

2017-01-01

The AgI Seeding Cloud Impact Investigation (ASCII) campaign, conducted in early 2012 and 2013 over two mountain ranges in southern Wyoming, was designed to examine the impact of ground-based glaciogenic seeding on snow growth in winter orographic clouds. Part I of this study (Pokharel and Geerts, 2016) describes the project design, instrumentation, as well as the ambient atmospheric conditions and macrophysical and microphysical properties of the clouds sampled in ASCII. This paper (Part II) explores how the silver iodide (AgI) seeding affects snow growth in these orographic clouds in up to 27 intensive operation periods (IOPs), depending on the instrument used. In most cases, 2 h without seeding (NOSEED) were followed by 2 h of seeding (SEED). In situ data at flight level (2D-probes) indicate higher concentrations of small snow particles during SEED in convective clouds. The double difference of radar reflectivity Z (SEED - NOSEED in the target region, compared to the same trend in the control region) indicates an increase in Z for the composite of ASCII cases, over either mountain range, and for any of the three radar systems (WCR, MRR, and DOW), each with their own control and target regions, and for an array of snow gauges. But this double difference varies significantly from case to case, which is attributed to uncertainties related to sampling representativeness and to differences in natural trends between control and target regions. We conclude that a sample much larger than ASCII's sample is needed for clear observational evidence regarding the sensitivity of seeding efficacy to atmospheric and cloud conditions.

Broad-Range 16S rDNA PCR on Heart Valves in Infective Endocarditis.

PubMed

Müller Premru, Manica; Lejko Zupanc, Tatjana; Klokočovnik, Tomislav; Ruzić Sabljić, Eva; Cerar, Tjaša

2016-03-01

Infective endocarditis (IE) is diagnosed by blood and/or resected valve cultivation and echocardiographic findings, as defined by the Duke criteria. Unfortunately, cultures may be negative due to prior antibiotic therapy or fastidious or slow-growing microorganisms. The study aim was to investigate the value of the broad-range polymerase chain reaction (PCR) in addition to blood and valve culture for the detection of causative microorganisms. Between February 2012 and March 2015, valve samples from 36 patients undergoing cardiac surgery were analyzed; of these patients, 26 had a preoperative diagnosis of IE and 10 served as controls. Multiple blood cultures were obtained from 34 patients before antibiotic therapy was commenced. Valve samples were inoculated on bacteriological media and underwent analysis using broad-range PCR (16S rDNA). IE was confirmed microbiologically in 21 of the 26 patients (80.7%); in 20 cases (76.9%) this was by positive blood cultures and in 16 (61.5%) by positive valves. Valves were positive in 15 blood culturepositive patients, and in one blood-culture negative patient. Broad-range PCR detected a microorganism in valves significantly more frequently (n = 14; 53.8%) compared to valve culture (n = 8; 30.7%) (chisquare 11.5, p <0.001). The predominant microorganisms were Staphylococcus aureus, Streptococcus of the viridans group, coagulasenegative staphylococci and Enterococcus faecalis. Blood, valve cultures and broad-range PCR were negative in five patients (19.3%) with IE, and in all 10 subjects of the control group. Broad-range PCR on valves was more sensitive than valve culture. However, blood culture, if taken before the start of antibiotic therapy, was the best method for detecting IE.

Prescribing patterns and the use of therapeutic drug monitoring of psychotropic medication in a psychiatric high-security unit.

PubMed

Castberg, Ingrid; Spigset, Olav

2008-10-01

The aim of this study was to investigate the use of psychotropic medication and therapeutic drug monitoring in a high-security psychiatric unit and to compare the doses and serum concentrations both with the recommended intervals and with the doses and serum concentrations in a control group. One hundred thirty-two patients were admitted in the period from January 2000 to December 2005. All available samples were used when comparing serum concentrations and doses with the recommended ranges. For the comparison of doses and serum concentration-to-dose (C:D) ratios with the control group only 1 sample from each patient was used. A total of 459 analyses of 27 different drugs in samples from 8 women and 73 men were included. The median number of therapeutic drug monitoring analyses per patient was 4 (range 1-29). Thirty-seven of the 81 patients (46%) used 2 or more antipsychotics at the same time. Clozapine, lamotrigine, olanzapine, quetiapine, ziprasidone, and zuclopenthixol were often given in doses above the recommended. The serum levels were frequently above those recommended for clozapine, olanzapine, quetiapine, risperidone, ziprasidone, and zuclopenthixol. The serum levels were significantly higher in the study group than in the control group for clozapine, lamotrigine, quetiapine, and zuclopenthixol. The given dose was significantly higher in the study group than in the control group for clozapine, lamotrigine and zuclopenthixol. The C:D ratio was significantly lower in the study group than in the control group for olanzapine but higher for quetiapine. The non-evidence based practice of high-dose polypharmacy with several antipsychotics is widely used in this unit. The use of higher doses in the study group than in the control group was not due to differences in metabolism or adherence to treatment between the 2 groups. The frequent use of therapeutic drug monitoring did not seem to have a great impact on the prescribed doses.

Psychoticism and disruptive behavior can be also good predictors of school achievement.

PubMed

Flores-Mendoza, Carmen; Widaman, Keith; Mansur-Alves, Marcela; Bacelar, Tatiane Dias; Saldanha, Renata

2013-01-01

The relations of Gf (Standard Progressive Matrices Raven), Gc (verbal scale of Wechsler Intelligence Scale for Children-Third Version), personality dimensions (Eysenck Personality Questionnaire-Junior Version), and disruptive behavior (TDAH scale) with school achievement (measured by TDE test and PISA test) were investigated. Two samples of students (total N = 534) representing a broad range of socioeconomic status (SES) participated in this study. Path models were conducted. The results demonstrated that (1) in both samples no sex differences related to school achievement were found; (2) in the first sample, after controlling for age and SES differences, Gf and psychoticism predicted (.38 and -.13, respectively) school achievement (measured by TDE test); (3) in the second sample, after controlling for SES differences to which additional measures were administered, Gf and Gc positively predicted (.22 and .40, respectively) school achievement (measured by PISA test). In addition, psychoticism and disruptive behavior also predicted school performance (-.14 and -.28, respectively). Some theoretical and practical implications are discussed.

Assessment of TREM2 rs75932628 association with Alzheimer's disease in a population-based sample: the Cache County Study.

PubMed

Gonzalez Murcia, Josue D; Schmutz, Cameron; Munger, Caitlin; Perkes, Ammon; Gustin, Aaron; Peterson, Michael; Ebbert, Mark T W; Norton, Maria C; Tschanz, Joann T; Munger, Ronald G; Corcoran, Christopher D; Kauwe, John S K

2013-12-01

Recent studies have identified the rs75932628 (R47H) variant in TREM2 as an Alzheimer's disease risk factor with estimated odds ratio ranging from 2.9 to 5.1. The Cache County Memory Study is a large, population-based sample designed for the study of memory and aging. We genotyped R47H in 2974 samples (427 cases and 2540 control subjects) from the Cache County study using a custom TaqMan assay. We observed 7 heterozygous cases and 12 heterozygous control subjects with an odds ratio of 3.5 (95% confidence interval, 1.3-8.8; p = 0.0076). The minor allele frequency and population attributable fraction for R47H were 0.0029 and 0.004, respectively. This study replicates the association between R47H and Alzheimer's disease risk in a large, population-based sample, and estimates the population frequency and attributable risk of this rare variant. Copyright © 2013 Elsevier Inc. All rights reserved.

Cognitive development in Silver-Russell syndrome: a sibling-controlled study.

PubMed

Noeker, Meinolf; Wollmann, Hartmut A

2004-05-01

This study examined cognitive development in Silver-Russell syndrome (SRS), a condition with intrauterine growth retardation, persisting short stature, and specific stigmata. Neuropsychological function and cognitive abilities were assessed in a sample of 36 children with SRS (21 males, 15 females; mean age 7 years 6 months, SD 2 years 8 months; age range 3 to 12 years) and 25 normally developing siblings (mean age 8 years 6 months, SD 2 years 7 months; age range 3 to 12 years) using the Kaufman Assessment Battery for Children. Special measures were taken to control for confounding factors and sample bias. Mean overall IQ score in the total SRS sample (95.7, SD 10.63), as measured by the Mental Processing Composite Scale, was significantly reduced (p=0.021) compared with test norms (IQ 100, SD 15), indicating a moderate cognitive impairment. Subscale analysis revealed some specific deficiencies. However, these cannot be attributed to an established category of specific learning disorder. The mean score in the Achievement Scale (91.25, SD 14.92), which is more sensitive to educational influences, showed stronger deficits (p=0.001). The sibling control group achieved a slightly better mean IQ score (104.20, SD 12.32) than test norms (p=0.10). Direct analysis of paired differences between the subsample of children with SRS and a sibling among the control group (n=25) revealed a significant mean difference of 8.08 IQ points (p=0.011). Risk factor analysis revealed that cognitive development is not associated with birth length (p=0.404), birthweight (p=0.820), growth hormone therapy (p=0.810), phenotypic severity (p=0.828), or sex (p=0.880). Two children with maternal uniparental disomy for the entire chromosome 7 had markedly lower IQ scores (81 and 84 respectively). In contrast to the few previous findings, children with SRS show only moderate, but significant, impairments in cognitive outcome, which are more striking in our sample when compared with siblings than with test norms.

Articulatory-acoustic vowel space: application to clear speech in individuals with Parkinson's disease.

PubMed

Whitfield, Jason A; Goberman, Alexander M

2014-01-01

Individuals with Parkinson disease (PD) often exhibit decreased range of movement secondary to the disease process, which has been shown to affect articulatory movements. A number of investigations have failed to find statistically significant differences between control and disordered groups, and between speaking conditions, using traditional vowel space area measures. The purpose of the current investigation was to evaluate both between-group (PD versus control) and within-group (habitual versus clear) differences in articulatory function using a novel vowel space measure, the articulatory-acoustic vowel space (AAVS). The novel AAVS is calculated from continuously sampled formant trajectories of connected speech. In the current study, habitual and clear speech samples from twelve individuals with PD along with habitual control speech samples from ten neurologically healthy adults were collected and acoustically analyzed. In addition, a group of listeners completed perceptual rating of speech clarity for all samples. Individuals with PD were perceived to exhibit decreased speech clarity compared to controls. Similarly, the novel AAVS measure was significantly lower in individuals with PD. In addition, the AAVS measure significantly tracked changes between the habitual and clear conditions that were confirmed by perceptual ratings. In the current study, the novel AAVS measure is shown to be sensitive to disease-related group differences and within-person changes in articulatory function of individuals with PD. Additionally, these data confirm that individuals with PD can modulate the speech motor system to increase articulatory range of motion and speech clarity when given a simple prompt. The reader will be able to (i) describe articulatory behavior observed in the speech of individuals with Parkinson disease; (ii) describe traditional measures of vowel space area and how they relate to articulation; (iii) describe a novel measure of vowel space, the articulatory-acoustic vowel space and its relationship to articulation and the perception of speech clarity. Copyright © 2014 Elsevier Inc. All rights reserved.

Polarization-controlled optimal scatter suppression in transient absorption spectroscopy

PubMed Central

Malý, Pavel; Ravensbergen, Janneke; Kennis, John T. M.; van Grondelle, Rienk; Croce, Roberta; Mančal, Tomáš; van Oort, Bart

2017-01-01

Ultrafast transient absorption spectroscopy is a powerful technique to study fast photo-induced processes, such as electron, proton and energy transfer, isomerization and molecular dynamics, in a diverse range of samples, including solid state materials and proteins. Many such experiments suffer from signal distortion by scattered excitation light, in particular close to the excitation (pump) frequency. Scattered light can be effectively suppressed by a polarizer oriented perpendicular to the excitation polarization and positioned behind the sample in the optical path of the probe beam. However, this introduces anisotropic polarization contributions into the recorded signal. We present an approach based on setting specific polarizations of the pump and probe pulses, combined with a polarizer behind the sample. Together, this controls the signal-to-scatter ratio (SSR), while maintaining isotropic signal. We present SSR for the full range of polarizations and analytically derive the optimal configuration at angles of 40.5° between probe and pump and of 66.9° between polarizer and pump polarizations. This improves SSR by (or compared to polarizer parallel to probe). The calculations are validated by transient absorption experiments on the common fluorescent dye Rhodamine B. This approach provides a simple method to considerably improve the SSR in transient absorption spectroscopy. PMID:28262765

Uranium quantification in semen by inductively coupled plasma mass spectrometry

USGS Publications Warehouse

Todorov, Todor I.; Ejnik, John W.; Guandalini, Gustavo S.; Xu, Hanna; Hoover, Dennis; Anderson, Larry W.; Squibb, Katherine; McDiarmid, Melissa A.; Centeno, Jose A.

2013-01-01

In this study we report uranium analysis for human semen samples. Uranium quantification was performed by inductively coupled plasma mass spectrometry. No additives, such as chymotrypsin or bovine serum albumin, were used for semen liquefaction, as they showed significant uranium content. For method validation we spiked 2 g aliquots of pooled control semen at three different levels of uranium: low at 5 pg/g, medium at 50 pg/g, and high at 1000 pg/g. The detection limit was determined to be 0.8 pg/g uranium in human semen. The data reproduced within 1.4–7% RSD and spike recoveries were 97–100%. The uranium level of the unspiked, pooled control semen was 2.9 pg/g of semen (n = 10). In addition six semen samples from a cohort of Veterans exposed to depleted uranium (DU) in the 1991 Gulf War were analyzed with no knowledge of their exposure history. Uranium levels in the Veterans’ semen samples ranged from undetectable (<0.8 pg/g) to 3350 pg/g. This wide concentration range for uranium in semen is consistent with known differences in current DU body burdens in these individuals, some of whom have retained embedded DU fragments.

Levels of heavy metals and essential minerals in hair samples of children with autism in Oman: a case-control study.

PubMed

Al-Farsi, Yahya M; Waly, Mostafa I; Al-Sharbati, Marwan M; Al-Shafaee, Mohammed A; Al-Farsi, Omar A; Al-Khaduri, Maha M; Gupta, Ishita; Ouhtit, Allal; Al-Adawi, Samir; Al-Said, Mona F; Deth, Richard C

2013-02-01

Toxic levels of heavy metals and low levels of essential minerals have been suggested to play a critical role in the pathogenesis of autism spectrum disorders (ASD). This study documents the levels of heavy metals and essential minerals in hair samples of children with ASD in Muscat, the urbanized capital of Oman, Muscat. The study included 27 children with ASD and 27 matched non-ASD controls. Parental interviews were held and dietary intake questionnaires completed in conjunction with the collection of hair samples. Analysis of heavy metals and essential minerals was carried out by inductively coupled plasma mass spectrometry. Chi-square analysis and non-parametric Fisher's exact tests were used to assess statistical significance. Children with ASD had significantly higher levels of all 11 analyzed heavy metals in their hair samples (P < 0.05), ranging from 150 to 365 % of control levels. ASD children also had significantly higher levels of essential minerals sulfur, sodium, magnesium, potassium, zinc, and iron, but lower levels of calcium and copper in their hair samples. This study corroborates data from previous studies in different parts of the world indicating the presence of elevated levels of heavy metals and selective depletion of essential minerals in the hair of children with ASD.

Noise and complexity in human postural control: interpreting the different estimations of entropy.

PubMed

Rhea, Christopher K; Silver, Tobin A; Hong, S Lee; Ryu, Joong Hyun; Studenka, Breanna E; Hughes, Charmayne M L; Haddad, Jeffrey M

2011-03-17

Over the last two decades, various measures of entropy have been used to examine the complexity of human postural control. In general, entropy measures provide information regarding the health, stability and adaptability of the postural system that is not captured when using more traditional analytical techniques. The purpose of this study was to examine how noise, sampling frequency and time series length influence various measures of entropy when applied to human center of pressure (CoP) data, as well as in synthetic signals with known properties. Such a comparison is necessary to interpret data between and within studies that use different entropy measures, equipment, sampling frequencies or data collection durations. The complexity of synthetic signals with known properties and standing CoP data was calculated using Approximate Entropy (ApEn), Sample Entropy (SampEn) and Recurrence Quantification Analysis Entropy (RQAEn). All signals were examined at varying sampling frequencies and with varying amounts of added noise. Additionally, an increment time series of the original CoP data was examined to remove long-range correlations. Of the three measures examined, ApEn was the least robust to sampling frequency and noise manipulations. Additionally, increased noise led to an increase in SampEn, but a decrease in RQAEn. Thus, noise can yield inconsistent results between the various entropy measures. Finally, the differences between the entropy measures were minimized in the increment CoP data, suggesting that long-range correlations should be removed from CoP data prior to calculating entropy. The various algorithms typically used to quantify the complexity (entropy) of CoP may yield very different results, particularly when sampling frequency and noise are different. The results of this study are discussed within the context of the neural noise and loss of complexity hypotheses.

Evaluation of drug incorporation into hair segments and nails by enantiomeric analysis following controlled single MDMA intakes.

PubMed

Madry, Milena M; Steuer, Andrea E; Hysek, Cédric M; Liechti, Matthias E; Baumgartner, Markus R; Kraemer, Thomas

2016-01-01

Incorporation rates of the enantiomers of 3,4-methylenedioxymethamphetamine (MDMA) and its metabolite 3,4-methylenedioxyamphetamine (MDA) into hair and nails were investigated after controlled administration. Fifteen subjects without MDMA use received two doses of 125 mg of MDMA. Hair, nail scrapings, and nail clippings were collected 9-77 days after the last administration (median 20 days). Hair samples were analyzed in segments of 1- to 2-cm length. After chiral derivatization with N-(2,4-dinitro-5-fluorophenyl)-L-valinamide, MDMA and MDA diastereomers were analyzed by liquid chromatography-tandem mass spectrometry. Highest concentrations in hair segments corresponded to the time of MDMA intake. They ranged from 101 to 3200 pg/mg and 71 to 860 pg/mg for R- and S-MDMA, and from 3.2 to 116 pg/mg and 4.4 to 108 pg/mg for R- and S-MDA, respectively. MDMA and MDA concentrations in nail scrapings and clippings were significantly lower than in hair samples. There was no significant difference between enantiomeric ratios of R/S-MDMA and R/S-MDA in hair and nail samples (medians 2.2-2.4 for MDMA and 0.85-0.95 for MDA). Metabolite ratios of MDA to MDMA were in the same range in hair and nail samples (medians 0.044-0.055). Our study demonstrates that administration of two representative doses of MDMA was detected in the hair segments corresponding to the time of intake based on average hair growth rates. MDMA was detected in all nail samples regardless of time passed after intake. Comparable R/S ratios in hair and nail samples may indicate that incorporation mechanisms into both matrices are comparable.

Geochemical processes and the effects of natural organic solutes on the solubility of selenium in coal-mine backfill samples from the Powder River basin, Wyoming

USGS Publications Warehouse

See, R.B.; Reddy, K.J.; Vance, G.F.; Fadlelmawla, A.A.; Blaylock, M.J.

1995-01-01

Geochemical processes and the effects of natural organic solutes on the solubility of selenium in coal-mine backfill aquifers were investigated. Backfill and ground-water samples were collected at coal mines in the Powder River Basin, Wyoming. Backfill was generally dominated by aluminum (14,400 to 49,000 mg/kg (milligrams per kilogram)), iron (3,330 to 23,200 mg/kg), and potassium (7,950 to 18,000 mg/kg). Backfill saturated-paste selenium concentrations ranged from 1 to 156 mg/kg (microsiemens per kilogram). Ground-water total selenium concentrations ranged from 3 to 125 mg/L. Dissolved organic carbon in all ground-water samples was dominated by hydrophobic and hydrophilic acids (38 to 84 percent). Selenite sorption/desorption experiments were conducted using background solutions of distilled-deionized water, 0.1 molar calcium chloride, and isolated hydrophobic and hydrophilic acids. Selenite sorption was larger when 0.1 molar calcium chloride was used. The addition of hydrophilic acid decreased selenite sorption more than the addition of hydrophobic acids. Geochemical modelling was used to predict the solid phases controlling dissolved selenium concentrations and to evaluate the effects of dissolved organic carbon on selenium solubility. Results suggested that 55 to 90 percent of selenium in backfill precipitation/dissolution extracts was dominated by magnesium selenate ion pairs. Dissolved organic carbon had little effect on selenium speciation. A redox chamber was constructed to control Eh and pH in water and backfill-core sample suspensions. The response of selenite and selenate in water samples to redox conditions did not follow thermodynamic predictions. Reduction of selenate in water samples did not occur at any of the redox levels tested.

Automation of serum (1→3)-beta-D-glucan testing allows reliable and rapid discrimination of patients with and without candidemia.

PubMed

Prüller, Florian; Wagner, Jasmin; Raggam, Reinhard B; Hoenigl, Martin; Kessler, Harald H; Truschnig-Wilders, Martie; Krause, Robert

2014-07-01

Testing for (1→3)-beta-D-glucan (BDG) is used for detection of invasive fungal infection. However, current assays lack automation and the ability to conduct rapid single-sample testing. The Fungitell assay was adopted for automation and evaluated using clinical samples from patients with culture-proven candidemia and from culture-negative controls in duplicate. A comparison with the standard assay protocol was made in order to establish analytical specifications. With the automated protocol, the analytical measuring range was 8-2500 pg/ml of BDG, and precision testing resulted in coefficients of variation that ranged from 3.0% to 5.5%. Samples from 15 patients with culture-proven candidemia and 94 culture-negative samples were evaluated. All culture-proven samples showed BDG values >80 pg/ml (mean 1247 pg/ml; range, 116-2990 pg/ml), which were considered positive. Of the 94 culture-negative samples, 92 had BDG values <60 pg/ml (mean, 28 pg/ml), which were considered to be negative, and 2 samples were false-positive (≥80 pg/ml; up to 124 pg/ml). Results could be obtained within 45 min and showed excellent agreement with results obtained with the standard assay protocol. The automated Fungitell assay proved to be reliable and rapid for diagnosis of candidemia. It was demonstrated to be feasible and cost efficient for both single-sample and large-scale testing of serum BDG. Its 1-h time-to-result will allow better support for clinicians in the management of antifungal therapy. © The Author 2014. Published by Oxford University Press on behalf of The International Society for Human and Animal Mycology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Development of sampling plans for cotton bolls injured by stink bugs (Hemiptera: Pentatomidae).

PubMed

Reay-Jones, F P F; Toews, M D; Greene, J K; Reeves, R B

2010-04-01

Cotton, Gossypium hirsutum L., bolls were sampled in commercial fields for stink bug (Hemiptera: Pentatomidae) injury during 2007 and 2008 in South Carolina and Georgia. Across both years of this study, boll-injury percentages averaged 14.8 +/- 0.3 (SEM). At average boll injury treatment levels of 10, 20, 30, and 50%, the percentage of samples with at least one injured boll was 82, 97, 100, and 100%, respectively. Percentage of field-sampling date combinations with average injury < 10, 20, 30, and 50% was 35, 80, 95, and 99%, respectively. At the average of 14.8% boll injury or 2.9 injured bolls per 20-boll sample, 112 samples at Dx = 0.1 (within 10% of the mean) were required for population estimation, compared with only 15 samples at Dx = 0.3. Using a sample size of 20 bolls, our study indicated that, at the 10% threshold and alpha = beta = 0.2 (with 80% confidence), control was not needed when <1.03 bolls were injured. The sampling plan required continued sampling for a range of 1.03-3.8 injured bolls per 20-boll sample. Only when injury was > 3.8 injured bolls per 20-boll sample was a control measure needed. Sequential sampling plans were also determined for thresholds of 20, 30, and 50% injured bolls. Sample sizes for sequential sampling plans were significantly reduced when compared with a fixed sampling plan (n=10) for all thresholds and error rates.

Validation of Recipes for Double-Blind Placebo-Controlled Challenges With Milk, Egg White, and Hazelnut.

PubMed

González-Mancebo, E; Alonso Díaz de Durana, M D; García Estringana, Y; Meléndez Baltanás, A; Rodriguez-Alvarez, M; de la Hoz Caballer, B; Del Prado, N; Fernández-Rivas, M

The double-blind, placebo-controlled food challenge (DBPCFC) is considered the definitive diagnostic test for food allergy. Nevertheless, validated recipes for masking the foods are scarce, have not been standardized, and differ between centers. Sensory evaluation techniques such as the triangle test are necessary to validate the recipes used for DBPCFC. We developed 3 recipes for use in DBPCFC with milk, egg white, and hazelnut and used the triangle test to validate them in a 2-phase study in which 197 volunteers participated. In each phase, participants tried 3 samples (2 active-1 placebo or 2 placebo-1 active) and had to identify the odd one. In phase 1, the 3 samples were given simultaneously, whereas in phase 2, the 3 samples of foods that failed validation in phase 1 were given sequentially. A visual analog scale (VAS) ranging from 1 to 10 was used to evaluate how much participants liked the recipes. In phase 1, the egg white recipe was validated (n=89 volunteers, 38.9% found the odd sample, P=.16). Milk and hazelnut recipes were validated in phase 2 (for both foods, n=30 participants, 36.7% found the odd sample, P=.36). Median VAS scores for the 3 recipes ranged from 6.6 to 9.7. We used sensory testing to validate milk, egg white, and hazelnut recipes for use in DBPCFC. The validated recipes are easy to prepare in a clinical setting, provide the equivalent of 1 serving dose, and were liked by most participants.

Performance of a novel high throughput method for the determination of VX in drinking water samples.

PubMed

Knaack, Jennifer S; Zhou, Yingtao; Magnuson, Matthew; Silvestri, Erin; Johnson, Rudolph C

2013-03-05

VX (O-ethyl-S-(2-diisopropylaminoethyl) methylphosphonothioate) is a highly toxic organophosphorus nerve agent, and even low levels of contamination in water can be harmful. Measurement of low concentrations of VX in aqueous matrixes is possible using an immunomagnetic scavenging technique and detection using liquid chromatography/tandem-mass spectrometry. Performance of the method was characterized in high-performance liquid chromatography (HPLC)-grade water preserved with sodium omadine, an antimicrobial agent, and sodium thiosulfate, a dechlorinating agent, over eight analytical batches with quality control samples analyzed over 10 days. The minimum reportable level was 25 ng/L with a linear dynamic range up to 4.0 μg/L. The mean accuracies for two quality control samples containing VX at concentrations of 0.250 and 2.00 μg/L were 102 ± 3% and 103 ± 6%, respectively. The stability of VX was determined in five tap water samples representing a range of water quality parameters and disinfection practices over a 91 day period. In preserved tap water samples, VX recovery was between 81 and 92% of the fortified amount, 2.0 μg/L, when analyzed immediately after preparation. Recovery of VX decreased to between 31 and 45% of the fortified amount after 91 days, indicating hydrolysis of VX. However, the preservatives minimized the hydrolysis rate to close to the theoretical limit. The ability to detect low concentrations of VX in preserved tap water 91 days after spiking suggests applicability of this method for determining water contamination with VX and utility during environmental remediation.

Good performance of an immunoassay based method for nevirapine measurements in human breast milk.

PubMed

Salado-Rasmussen, Kirsten; Theilgaard, Zahra Persson; Chiduo, Mercy; Pedersen, Court; Gerstoft, Jan; Katzenstein, Terese Lea

2011-07-01

Understanding the distribution of antiretro-virals in breastfeeding HIV-positive mothers is essential, both for prevention of mother-to-child HIV transmission and for research on the development of drug resistance. The ARK nevirapine (NVP)-test is an immunoassay method for nevirapine measurements, developed and validated for plasma use. In this study, the ARK NVP-test was evaluated for measurement of nevirapine concentrations in breast milk. High performance liquid chromatography (HPLC) is the method currently used to determine nevirapine in breast milk. This method, however, requires complicated extraction techniques. The ARK method employs an immunoassay technology and requires a small sample volume (40 μL) and no pre-treatment of the samples. Commercial enzyme and antibody were used and calibration standards and quality controls were prepared from pooled breast milk from HIV-uninfected women. Clinical samples from HIV-infected women receiving a single-dose of nevirapine were analyzed. Precision and accuracy were evaluated with two concentrations of quality control materials analyzed in three replicates on four different days and was <4%, and between 96.5% and 104.6%, respectively. Clinical samples were analyzed and CVs ranged from 0.0% to 11.1%. The median nevirapine concentration in breast milk 1 week post-partum was 0.29 μg/mL (range 0.11-0.90 μg/mL) in women treated with a single-dose of nevirapine. The ease of use and small sample volume makes the ARK assay an attractive alternative to HPLC analyses for determinations of nevirapine concentrations in breast milk.

Validation of PCR methods for quantitation of genetically modified plants in food.

PubMed

Hübner, P; Waiblinger, H U; Pietsch, K; Brodmann, P

2001-01-01

For enforcement of the recently introduced labeling threshold for genetically modified organisms (GMOs) in food ingredients, quantitative detection methods such as quantitative competitive (QC-PCR) and real-time PCR are applied by official food control laboratories. The experiences of 3 European food control laboratories in validating such methods were compared to describe realistic performance characteristics of quantitative PCR detection methods. The limit of quantitation (LOQ) of GMO-specific, real-time PCR was experimentally determined to reach 30-50 target molecules, which is close to theoretical prediction. Starting PCR with 200 ng genomic plant DNA, the LOQ depends primarily on the genome size of the target plant and ranges from 0.02% for rice to 0.7% for wheat. The precision of quantitative PCR detection methods, expressed as relative standard deviation (RSD), varied from 10 to 30%. Using Bt176 corn containing test samples and applying Bt176 specific QC-PCR, mean values deviated from true values by -7to 18%, with an average of 2+/-10%. Ruggedness of real-time PCR detection methods was assessed in an interlaboratory study analyzing commercial, homogeneous food samples. Roundup Ready soybean DNA contents were determined in the range of 0.3 to 36%, relative to soybean DNA, with RSDs of about 25%. Taking the precision of quantitative PCR detection methods into account, suitable sample plans and sample sizes for GMO analysis are suggested. Because quantitative GMO detection methods measure GMO contents of samples in relation to reference material (calibrants), high priority must be given to international agreements and standardization on certified reference materials.

A compendium of controlled diffusion blades generated by an automated inverse design procedure

NASA Technical Reports Server (NTRS)

Sanz, Jose M.

1989-01-01

A set of sample cases was produced to test an automated design procedure developed at the NASA Lewis Research Center for the design of controlled diffusion blades. The range of application of the automated design procedure is documented. The results presented include characteristic compressor and turbine blade sections produced with the automated design code as well as various other airfoils produced with the base design method prior to the incorporation of the automated procedure.

A four-year follow-up controlled study of stress response and symptom persistence in Brazilian children and adolescents with attention deficit disorder and hyperactivity (ADHD).

PubMed

Palma, Sonia Maria Motta; Natale, Ana Carolina Motta Palma; Calil, Helena Maria

2015-12-15

This study evaluated children and adolescents with Attention Deficit Disorder andHyperactivity Disorder (ADHD), reassessing them at a four-year follow-up. Their cortisol response to a stress stimulus was measured twice. ADHD symptom persistence, development of comorbidities, and psychostimulant usage were also reassessed. The initial sample consisted of 38 ADHD patients and 38 healthy controls, age ranging 6-14. At the follow-up, there were 37 ADHD patients and 22 healthy controls, age ranging 10-18. ADHD was classified as persistent if the patients fulfilled all DSM IV criteria for syndromic or subthreshold or had functional impairment. Salivary cortisol samples were collected prior to the application of a cognitive stressor (Continuous Performance Test - CPT), and at three time intervals afterwards at baseline and at the follow-up. Their reassessment showed that 75% had persistent symptoms, psychiatric comorbidities (oppositional defiant and behavioral disorders), functional and academic impairement. Only seven patients were on medication. The ADHD group's cortisol levels were lower than those measured four years earlier, but cortisol concentrations were similar for both ADHD and control groups at the four-year follow-up. The cortisol results suggest that HPA axis reactivity could be a marker differentiating ADHD from ADHD with comorbidities. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Lactic acid concentrations that reduce microbial load yet minimally impact colour and sensory characteristics of beef.

PubMed

Rodríguez-Melcón, Cristina; Alonso-Calleja, Carlos; Capita, Rosa

2017-07-01

Lactic acid (LA) has recently been approved in the EU as beef decontaminant. In order to identify the most appropriate concentration, beef samples were spray-treated with LA (2%, 3%, 4% or 5%) or left untreated (control). Microbial load (aerobic plate counts, psychrotrophs and Enterobacteriaceae), pH, instrumental colour and sensory properties were investigated at 0, 24, 72 and 120h of refrigerated storage. The reductions in bacteria after spraying ranged from 0.57 to 0.95 log units. A residual antimicrobial effect was observed so that at 120h LA reduced microbial load by up to 2 log units compared with the control samples. Samples treated with 5% LA showed the lowest redness value (a*) and hedonic scores at all sampling times. Only for samples treated with 4% LA did the sensorial shelf-life limit extend beyond 120h. It is suggested that treatment of beef with 4% LA not only may improve microbiological quality, but also may enhance sensory properties and shelf-life. Copyright © 2017. Published by Elsevier Ltd.

Controlling of dielectrical properties of hydroxyapatite by ethylenediamine tetraacetic acid (EDTA) for bone healing applications.

PubMed

Kaygili, Omer; Ates, Tankut; Keser, Serhat; Al-Ghamdi, Ahmed A; Yakuphanoglu, Fahrettin

2014-08-14

The hydroxyapatite (HAp) samples in the presence of various amounts of ethylenediamine tetraacetic acid (EDTA) were prepared by sol-gel method. The effects of EDTA on the crystallinity, phase structure, chemical, micro-structural and dielectric properties of HAp samples were investigated. With the addition of EDTA, the average crystallite size of the HAp samples is gradually decreased from 30 to 22 nm and the crystallinity is in the range of 65-71%. The values of the lattice parameters (a and c) and volume of the unit cell are decreased by stages with the addition of EDTA. The dielectric parameters such as relative permittivity, dielectric loss and relaxation time are affected by the adding of EDTA. The alternating current conductivity of the as-synthesized hydroxyapatites increases with the increasing frequency and obeys the universal power law behavior. The HAp samples exhibit a non-Debye relaxation mechanism. The obtained results that the dielectrical parameters of the HAp sample can be controlled by EDTA. Copyright © 2014 Elsevier B.V. All rights reserved.

Impacts of HIV infection and long-term use of antiretroviral therapy on the prevalence of oral human papilloma virus type 16.

PubMed

Amornthatree, Korntip; Sriplung, Hutcha; Mitarnun, Winyou; Nittayananta, Wipawee

2012-04-01

The objectives of this study were to determine (i) the prevalence and the copy numbers of oral human papilloma virus type 16 (HPV-16) in HIV-infected patients compared with non-HIV controls, and (ii) the effects of antiretroviral therapy (ART) and its duration on the virus. A cross-sectional study was carried out in HIV-infected patients with and without ART and in non-HIV controls. Saliva samples were collected, and the DNA extracted from those samples was used as a template to detect HPV-16 E6 and E7 by quantitative polymerase chain reaction. Student's t-test and ANOVA test were performed to determine the prevalence rates among groups. Forty-nine HIV-infected patients: 37 on ART (age range, 23-54 years; mean, 37 years), 12 not on ART (age range, 20-40 years; mean, 31 years), and 20 non-HIV controls (age range, 19-53 years; mean, 31 years) were enrolled. The prevalence of oral HPV-16 infection and the copy numbers of the virus were significantly higher in HIV-infected patients than in non-HIV controls when using E6 assay (geometric mean = 10696 vs. 563 copies/10(5) cells, P < 0.001), but not E7 assay. No significant difference was observed between those who were and were not on ART. Long-term use of ART did not significantly change the prevalence of oral HPV-16 infection and the copy numbers of the virus (P = 0.567). We conclude that the prevalence of oral HPV-16 infection and the copy numbers of the virus are increased by HIV infection. Neither the use of ART nor its duration significantly affected the virus. © 2011 John Wiley & Sons A/S.

Environmental chamber measurements of mercury flux from coal utilization by-products

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

Pekney, Natalie J.; Martello, Donald; Schroeder, Karl

2009-05-01

An environmental chamber was constructed to measure the mercury flux from coal utilization by-product (CUB) samples. Samples of fly ash, FGD gypsum, and wallboard made from FGD gypsum were tested under both dark and illuminated conditions with or without the addition of water to the sample. Mercury releases varied widely, with 7- day experiment averages ranging from -6.8 to 73 ng/m(2) h for the fly ash samples and -5.2 to 335 ng/m(2) h for the FGD/wallboard samples. Initial mercury content, fly ash type, and light exposure had no observable consistent effects on the mercury flux. For the fly ash samples,more » the effect of a mercury control technology was to decrease the emission. For three of the four pairs of FGD gypsum and wallboard samples, the wallboard sample released less (or absorbed more) mercury than the gypsum.« less

Environmental chamber measurements of mercury flux from coal utilization by-products

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

Pekney, N.J.; Martello, D.V.; Schroeder, K.T.

2009-05-01

An environmental chamber was constructed to measure the mercury flux from coal utilization by-product (CUB) samples. Samples of fly ash, FGD gypsum, and wallboard made from FGD gypsum were tested under both dark and illuminated conditions with or without the addition of water to the sample. Mercury releases varied widely, with 7-day experiment averages ranging from -6.8 to 73 ng/m2 h for the fly ash samples and -5.2 to 335 ng/m2 h for the FGD/wallboard samples. Initial mercury content, fly ash type, and light exposure had no observable consistent effects on the mercury flux. For the fly ash samples, themore » effect of a mercury control technology was to decrease the emission. For three of the four pairs of FGD gypsum and wallboard samples, the wallboard sample released less (or absorbed more) mercury than the gypsum.« less

Statistical considerations in evaluating pharmacogenomics-based clinical effect for confirmatory trials.

PubMed

Wang, Sue-Jane; O'Neill, Robert T; Hung, Hm James

2010-10-01

The current practice for seeking genomically favorable patients in randomized controlled clinical trials using genomic convenience samples. To discuss the extent of imbalance, confounding, bias, design efficiency loss, type I error, and type II error that can occur in the evaluation of the convenience samples, particularly when they are small samples. To articulate statistical considerations for a reasonable sample size to minimize the chance of imbalance, and, to highlight the importance of replicating the subgroup finding in independent studies. Four case examples reflecting recent regulatory experiences are used to underscore the problems with convenience samples. Probability of imbalance for a pre-specified subgroup is provided to elucidate sample size needed to minimize the chance of imbalance. We use an example drug development to highlight the level of scientific rigor needed, with evidence replicated for a pre-specified subgroup claim. The convenience samples evaluated ranged from 18% to 38% of the intent-to-treat samples with sample size ranging from 100 to 5000 patients per arm. The baseline imbalance can occur with probability higher than 25%. Mild to moderate multiple confounders yielding the same directional bias in favor of the treated group can make treatment group incomparable at baseline and result in a false positive conclusion that there is a treatment difference. Conversely, if the same directional bias favors the placebo group or there is loss in design efficiency, the type II error can increase substantially. Pre-specification of a genomic subgroup hypothesis is useful only for some degree of type I error control. Complete ascertainment of genomic samples in a randomized controlled trial should be the first step to explore if a favorable genomic patient subgroup suggests a treatment effect when there is no clear prior knowledge and understanding about how the mechanism of a drug target affects the clinical outcome of interest. When stratified randomization based on genomic biomarker status cannot be implemented in designing a pharmacogenomics confirmatory clinical trial, if there is one genomic biomarker prognostic for clinical response, as a general rule of thumb, a sample size of at least 100 patients may be needed to be considered for the lower prevalence genomic subgroup to minimize the chance of an imbalance of 20% or more difference in the prevalence of the genomic marker. The sample size may need to be at least 150, 350, and 1350, respectively, if an imbalance of 15%, 10% and 5% difference is of concern.

Analytical scanning evanescent microwave microscope and control stage

DOEpatents

Xiang, Xiao-Dong; Gao, Chen; Duewer, Fred; Yang, Hai Tao; Lu, Yalin

2013-01-22

A scanning evanescent microwave microscope (SEMM) that uses near-field evanescent electromagnetic waves to probe sample properties is disclosed. The SEMM is capable of high resolution imaging and quantitative measurements of the electrical properties of the sample. The SEMM has the ability to map dielectric constant, loss tangent, conductivity, electrical impedance, and other electrical parameters of materials. Such properties are then used to provide distance control over a wide range, from to microns to nanometers, over dielectric and conductive samples for a scanned evanescent microwave probe, which enable quantitative non-contact and submicron spatial resolution topographic and electrical impedance profiling of dielectric, nonlinear dielectric and conductive materials. The invention also allows quantitative estimation of microwave impedance using signals obtained by the scanned evanescent microwave probe and quasistatic approximation modeling. The SEMM can be used to measure electrical properties of both dielectric and electrically conducting materials.

Analytical scanning evanescent microwave microscope and control stage

DOEpatents

Xiang, Xiao-Dong; Gao, Chen; Duewer, Fred; Yang, Hai Tao; Lu, Yalin

2009-06-23

A scanning evanescent microwave microscope (SEMM) that uses near-field evanescent electromagnetic waves to probe sample properties is disclosed. The SEMM is capable of high resolution imaging and quantitative measurements of the electrical properties of the sample. The SEMM has the ability to map dielectric constant, loss tangent, conductivity, electrical impedance, and other electrical parameters of materials. Such properties are then used to provide distance control over a wide range, from to microns to nanometers, over dielectric and conductive samples for a scanned evanescent microwave probe, which enable quantitative non-contact and submicron spatial resolution topographic and electrical impedance profiling of dielectric, nonlinear dielectric and conductive materials. The invention also allows quantitative estimation of microwave impedance using signals obtained by the scanned evanescent microwave probe and quasistatic approximation modeling. The SEMM can be used to measure electrical properties of both dielectric and electrically conducting materials.

Effects of humidity on sterilization of Geobacillus stearothermophilus spores with plasma-excited neutral gas

NASA Astrophysics Data System (ADS)

Matsui, Kei; Ikenaga, Noriaki; Sakudo, Noriyuki

2015-06-01

We investigate the effects of relative humidity on the sterilization process using a plasma-excited neutral gas that uniformly sterilizes both the space and inner wall of the reactor chamber at atmospheric pressure. Only reactive neutral species such as plasma-excited gas molecules and radicals were separated from the plasma and sent to the reactor chamber for chemical sterilization. The plasma source gas is nitrogen mixed with 0.1% oxygen, and the relative humidity in the source gas is controlled by changing the mixing ratio of water vapor. The relative humidity near the sample in the reactor chamber is controlled by changing the sample temperature. As a result, the relative humidity near the sample should be kept in the range from 60 to 90% for the sterilization of Geobacillus stearothermophilus spores. When the relative humidity in the source gas increases from 30 to 90%, the sterilization effect is enhanced by the same degree.

Control technology for fiber reinforced plastics industry at AMF Hatteras Yachts, New Bern Division, New Bern, North Carolina

NASA Astrophysics Data System (ADS)

Todd, W. F.

1984-05-01

Area and breathing zone samples were analyzed for styrene (100425) at AMF Hatteras Yachts (SIC-3079), New Bern, North Carolina, in September, 1983. Control technology at the facility was inspected. Breathing zone styrene concentrations were 8 to 74 parts per million (ppm), the highest concentrations occurring in the lamination and gel coating departments. Area samples ranged from 1 to 20ppm. The OSHA standard is 100ppm. The hull lamination and assembly areas were ventilated by air make up units and exhaust blowers. Air exhausted through the lamination booths in the small parts work area was considerably less than the supply air from the make up units. The air flow in two of the three lamination booths was considered inadequate. Respirators were available if needed. Industrial hygiene sampling at the facility was supervised by the industrial hygienist.

Evaluation of dry blood spot technique for quantification of an Anti-CD20 monoclonal antibody drug in human blood samples.

PubMed

Lin, Yong-Qing; Zhang, Yilu; Li, Connie; Li, Louis; Zhang, Kelley; Li, Shawn

2012-01-01

To evaluate the dried blood spot (DBS) technique in ELISA quantification of larger biomolecular drugs, an anti-CD20 monoclonal antibody drug was used as an example. A method for the quantification of the anti-CD20 drug in human DBS was developed and validated. The drug standard and quality control samples prepared in fresh human blood were spotted on DBS cards and then extracted. A luminescent ELISA was used for quantification of the drug from DBS samples. The assay range of the anti-CD20 drug standards in DBS was 100-2500ng/mL. The intra-assay precision (%CV) ranged from 0.4% to 10.1%, and the accuracy (%Recovery) ranged from 77.9% to 113.9%. The inter assay precision (%CV) ranged from 5.9% to 17.4%, and the accuracy ranged from 81.5% to 110.5%. The DBS samples diluted 500 and 50-fold yielded recovery of 88.7% and 90.7%, respectively. The preparation of DBS in higher and lower hematocrit (53% and 35%) conditions did not affect the recovery of the drug. Furthermore, the storage stability of the anti-CD20 drug on DBS cards was tested at various conditions. It was found that the anti-CD20 drug was stable for one week in DBS stored at room temperature. However, it was determined that the stability was compro]mised in DBS stored at high humidity, high temperature (55°C), and exposed to direct daylight for a week, as well as for samples stored at room temperature and high humidity conditions for a month. Stability did not change significantly in samples that underwent 3 freeze/thaw cycles. Our results demonstrated a successful use of DBS technique in ELISA quantification of an anti-CD20 monoclonal antibody drug in human blood. The stability data provides information regarding sample storage and shipping for future clinical studies. It is, therefore, concluded that the DBS technique is applicable in the quantification of other large biomolecule drugs or biomarkers. Copyright © 2011 Elsevier Inc. All rights reserved.

Local but not long-range microstructural differences of the ventral temporal cortex in developmental prosopagnosia

PubMed Central

Song, Sunbin; Garrido, Lúcia; Nagy, Zoltan; Mohammadi, Siawoosh; Steel, Adam; Driver, Jon; Dolan, Ray J.; Duchaine, Bradley; Furl, Nicholas

2015-01-01

Individuals with developmental prosopagnosia (DP) experience face recognition impairments despite normal intellect and low-level vision and no history of brain damage. Prior studies using diffusion tensor imaging in small samples of subjects with DP (n=6 or n=8) offer conflicting views on the neurobiological bases for DP, with one suggesting white matter differences in two major long-range tracts running through the temporal cortex, and another suggesting white matter differences confined to fibers local to ventral temporal face-specific functional regions of interest (fROIs) in the fusiform gyrus. Here, we address these inconsistent findings using a comprehensive set of analyzes in a sample of DP subjects larger than both prior studies combined (n=16). While we found no microstructural differences in long-range tracts between DP and age-matched control participants, we found differences local to face-specific fROIs, and relationships between these microstructural measures with face recognition ability. We conclude that subtle differences in local rather than long-range tracts in the ventral temporal lobe are more likely associated with developmental prosopagnosia. PMID:26456436

Gross Motor Development in Children Aged 3-5 Years, United States 2012.

PubMed

Kit, Brian K; Akinbami, Lara J; Isfahani, Neda Sarafrazi; Ulrich, Dale A

2017-07-01

Objective Gross motor development in early childhood is important in fostering greater interaction with the environment. The purpose of this study is to describe gross motor skills among US children aged 3-5 years using the Test of Gross Motor Development (TGMD-2). Methods We used 2012 NHANES National Youth Fitness Survey (NNYFS) data, which included TGMD-2 scores obtained according to an established protocol. Outcome measures included locomotor and object control raw and age-standardized scores. Means and standard errors were calculated for demographic and weight status with SUDAAN using sample weights to calculate nationally representative estimates, and survey design variables to account for the complex sampling methods. Results The sample included 339 children aged 3-5 years. As expected, locomotor and object control raw scores increased with age. Overall mean standardized scores for locomotor and object control were similar to the mean value previously determined using a normative sample. Girls had a higher mean locomotor, but not mean object control, standardized score than boys (p < 0.05). However, the mean locomotor standardized scores for both boys and girls fell into the range categorized as "average." There were no other differences by age, race/Hispanic origin, weight status, or income in either of the subtest standardized scores (p > 0.05). Conclusions In a nationally representative sample of US children aged 3-5 years, TGMD-2 mean locomotor and object control standardized scores were similar to the established mean. These results suggest that standardized gross motor development among young children generally did not differ by demographic or weight status.

Short range micro-power impulse radar with high resolution swept range gate with damped transmit and receive cavities

DOEpatents

McEwan, Thomas E.

1998-01-01

A radar range finder and hidden object locator is based on ultra-wide band radar with a high resolution swept range gate. The device generates an equivalent time amplitude scan with atypical range of 4 inches to 20 feet, and an analog range resolution as limited by a jitter of on the order of 0.01 inches. A differential sampling receiver is employed to effectively eliminate ringing and other aberrations induced in the receiver by the near proximity of the transmit antenna, so a background subtraction is not needed, simplifying the circuitry while improving performance. Uses of the invention include a replacement of ultrasound devices for fluid level sensing, automotive radar, such as cruise control and parking assistance, hidden object location, such as stud and rebar finding. Also, this technology can be used when positioned over a highway lane to collect vehicle count and speed data for traffic control. Techniques are used to reduce clutter in the receive signal, such as decoupling the receive and transmit cavities by placing a space between them, using conductive or radiative damping elements on the cavities, and using terminating plates on the sides of the openings.

Short range micro-power impulse radar with high resolution swept range gate with damped transmit and receive cavities

DOEpatents

McEwan, T.E.

1998-06-30

A radar range finder and hidden object locator is based on ultra-wide band radar with a high resolution swept range gate. The device generates an equivalent time amplitude scan with atypical range of 4 inches to 20 feet, and an analog range resolution as limited by a jitter of on the order of 0.01 inches. A differential sampling receiver is employed to effectively eliminate ringing and other aberrations induced in the receiver by the near proximity of the transmit antenna, so a background subtraction is not needed, simplifying the circuitry while improving performance. Uses of the invention include a replacement of ultrasound devices for fluid level sensing, automotive radar, such as cruise control and parking assistance, hidden object location, such as stud and rebar finding. Also, this technology can be used when positioned over a highway lane to collect vehicle count and speed data for traffic control. Techniques are used to reduce clutter in the receive signal, such as decoupling the receive and transmit cavities by placing a space between them, using conductive or radiative damping elements on the cavities, and using terminating plates on the sides of the openings. 20 figs.

Examining the association between posttraumatic stress disorder and attention-deficit/hyperactivity disorder: a systematic review and meta-analysis.

PubMed

Spencer, Andrea E; Faraone, Stephen V; Bogucki, Olivia E; Pope, Amanda L; Uchida, Mai; Milad, Mohammed R; Spencer, Thomas J; Woodworth, K Yvonne; Biederman, Joseph

2016-01-01

To conduct a systematic review and meta-analysis examining the relationship between attention-deficit/hyperactivity disorder (ADHD) and posttraumatic stress disorder (PTSD). We reviewed literature through PubMed and PsycINFO without a specified date range, utilizing the search (posttraumatic stress disorder OR PTSD) AND (ADHD OR attention deficit hyperactivity disorder OR ADD OR attention deficit disorder OR hyperkinetic syndrome OR minimal brain dysfunction). References from relevant articles were reviewed. We identified 402 articles; 28 met criteria. We included original human research in English that operationalized diagnoses of ADHD and PTSD, evaluated the relationship between the disorders, and included controls. We excluded articles that failed to differentiate ADHD or PTSD from nonspecific or subsyndromal deficits or failed to compare their relationship. We extracted sample size, age, diagnostic methods, design, referral status, control type, and number of subjects with and without ADHD and PTSD alone and combined. We computed meta-analyses for 22 studies examining ADHD in PTSD and PTSD in ADHD using a random effects model and meta-analytic regression. We assessed for heterogeneity and publication bias and adjusted for intrastudy clustering. The relative risk (RR) for PTSD in ADHD was 2.9 (P < .0005); in samples using healthy controls, the RR was 3.7 (P = .001); and in samples using traumatized controls, the RR was 1.6 (P = .003). The RR for ADHD in PTSD was 1.7 (P < .0005); in samples using traumatized controls, the RR was 2.1 (P < .0005). The association was not significant in samples using psychiatric controls. Results indicate a bidirectional association between ADHD and PTSD, suggesting clinical implications and highlighting the need for neurobiological research that examines the mechanisms underlying this connection. © Copyright 2015 Physicians Postgraduate Press, Inc.

Patterning of alloy precipitation through external pressure

NASA Astrophysics Data System (ADS)

Franklin, Jack A.

Due to the nature of their microstructure, alloyed components have the benefit of meeting specific design goals across a wide range of electrical, thermal, and mechanical properties. In general by selecting the correct alloy system and applying a proper heat treatment it is possible to create a metallic sample whose properties achieve a unique set of design requirements. This dissertation presents an innovative processing technique intended to control both the location of formation and the growth rates of precipitates within metallic alloys in order to create multiple patterned areas of unique microstructure within a single sample. Specific experimental results for the Al-Cu alloy system will be shown. The control over precipitation is achieved by altering the conventional heat treatment process with an external surface load applied to selected locations during the quench and anneal. It is shown that the applied pressures affect both the rate and directionality of the atomic diffusion in regions close to the loaded surfaces. The control over growth rates is achieved by altering the enthalpic energy required for successful diffusion between lattice sites. Changes in the local chemical free energy required to direct the diffusion of atoms are established by introducing a non-uniform elastic strain energy field within the samples created by the patterned surface pressures. Either diffusion rates or atomic mobility can be selected as the dominating control process by varying the quench rate; with slower quenches having greater control over the mobility of the alloying elements. Results have shown control of Al2Cu precipitation over 100 microns on mechanically polished surfaces. Further experimental considerations presented will address consistency across sample ensembles. This includes repeatable pressure loading conditions and the chemical interaction between any furnace environments and both the alloy sample and metallic pressure loading devices.

An evaluation of analytical methods, air sampling techniques, and airborne occupational exposure of metalworking fluids.

PubMed

Verma, Dave K; Shaw, Don S; Shaw, M Lorraine; Julian, Jim A; McCollin, Shari-Ann; des Tombe, Karen

2006-02-01

This article summarizes an assessment of air sampling and analytical methods for both oil and water-based metalworking fluids (MWFs). Three hundred and seventy-four long-term area and personal airborne samples were collected at four plants using total (closed-face) aerosol samplers and thoracic samplers. A direct-reading device (DustTrak) was also used. The processes sampled include steel tube making, automotive component manufacturing, and small part manufacturing in a machine shop. The American Society for Testing and Materials (ASTM) Method PS42-97 of analysis was evaluated in the laboratory. This evaluation included sample recovery, determination of detection limits, and stability of samples during storage. Results of the laboratory validation showed (a) the sample recovery to be about 87%, (b) the detection limit to be 35 microg, and (c) sample stability during storage at room temperature to decline rapidly within a few days. To minimize sample loss, the samples should be stored in a freezer and analyzed within a week. The ASTM method should be the preferred method for assessing metalworking fluids (MWFs). The ratio of thoracic aerosol to total aerosol ranged from 0.6 to 0.7. A similar relationship was found between the thoracic extractable aerosol and total extractable aerosol. The DustTrak, with 10-microm sampling head, was useful in pinpointing the areas of potential exposure. MWF exposure at the four plants ranged from 0.04 to 3.84 mg/m3 with the geometric mean ranging between 0.22 to 0.59 mg/m3. Based on this data and the assumption of log normality, MWF exposures are expected to exceed the National Institute for Occupational Safety and Health recommended exposure limit of 0.5 mg/m3 as total mass and 0.4 mg/m3 as thoracic mass about 38% of the time. In addition to controlling airborne MWF exposure, full protection of workers would require the institution of programs for fluid management and dermal exposure prevention.

QCCM - Center for NMR Quantum Information Processing

DTIC Science & Technology

2011-02-16

2008, 77, 010802, 1 – 6. 8. Universal control of nuclear spins via anisotropic hyperfine interactions J. S. Hodges, J. C. Yang, C. Ramanthan and D. G...sample environmental noise over a broad frequency range 0.2-20MHz, and we observe a 1/fα-type spectrum which we independently confirm with a Rabi

Parental Relations, Mental Health, and Delinquency in Adolescents.

ERIC Educational Resources Information Center

Pederson, Willy

1994-01-01

A shortened version of the Parental Bonding Instrument, used in a sample of Norwegian adolescents, aged 15-19, indicated that adolescents' perceptions of mothers' and fathers' care and control/overprotection were related to measures of both depression/anxiety and delinquency. Scores may indicate risks in a broad range of psychosocial problems.…

Nocturnal Regrets and Insomnia in Elderly People

ERIC Educational Resources Information Center

Schmidt, Ralph E.; Renaud, Olivier; Van Der Linden, Martial

2011-01-01

Despite their importance for general health, emotion-related factors have rarely been considered in the etiology of late-life insomnia. This study explored the relations between impulsivity, regret experiences, use of different thought-control strategies, and insomnia severity in a sample of older adults whose age ranged from 51 to 98 years.…

Controls on Methane Occurrences in Aquifers Overlying the Eagle Ford Shale Play, South Texas.

PubMed

Nicot, Jean-Philippe; Larson, Toti; Darvari, Roxana; Mickler, Patrick; Uhlman, Kristine; Costley, Ruth

2017-07-01

Assessing natural vs. anthropogenic sources of methane in drinking water aquifers is a critical issue in areas of shale oil and gas production. The objective of this study was to determine controls on methane occurrences in aquifers in the Eagle Ford Shale play footprint. A total of 110 water wells were tested for dissolved light alkanes, isotopes of methane, and major ions, mostly in the eastern section of the play. Multiple aquifers were sampled with approximately 47 samples from the Carrizo-Wilcox Aquifer (250-1200 m depth range) and Queen City-Sparta Aquifer (150-900 m depth range) and 63 samples from other shallow aquifers but mostly from the Catahoula Formation (depth <150 m). Besides three shallow wells with unambiguously microbial methane, only deeper wells show significant dissolved methane (22 samples >1 mg/L, 10 samples >10 mg/L). No dissolved methane samples exhibit thermogenic characteristics that would link them unequivocally to oil and gas sourced from the Eagle Ford Shale. In particular, the well water samples contain very little or no ethane and propane (C1/C2+C3 molar ratio >453), unlike what would be expected in an oil province, but they also display relatively heavier δ 13 C methane (>-55‰) and δD methane (>-180‰). Samples from the deeper Carrizo and Queen City aquifers are consistent with microbial methane sourced from syndepositional organic matter mixed with thermogenic methane input, most likely originating from deeper oil reservoirs and migrating through fault zones. Active oxidation of methane pushes δ 13 C methane and δD methane toward heavier values, whereas the thermogenic gas component is enriched with methane owing to a long migration path resulting in a higher C1/C2+C3 ratio than in the local reservoirs. © 2017, National Ground Water Association.

Size and modal analyses of fines and ultrafines from some Apollo 17 samples

NASA Technical Reports Server (NTRS)

Greene, G. M.; King, D. T., Jr.; Banholzer, G. S., Jr.; King, E. A.

1975-01-01

Scanning electron and optical microscopy techniques have been used to determine the grain-size frequency distributions and morphology-based modal analyses of fine and ultrafine fractions of some Apollo 17 regolith samples. There are significant and large differences between the grain-size frequency distributions of the less than 10-micron size fraction of Apollo 17 samples, but there are no clear relations to the local geologic setting from which individual samples have been collected. This may be due to effective lateral mixing of regolith particles in this size range by micrometeoroid impacts. None of the properties of the frequency distributions support the idea of selective transport of any fine grain-size fraction, as has been proposed by other workers. All of the particle types found in the coarser size fractions also occur in the less than 10-micron particles. In the size range from 105 to 10 microns there is a strong tendency for the percentage of regularly shaped glass to increase as the graphic mean grain size of the less than 1-mm size fraction decreases, both probably being controlled by exposure age.

[Simultaneous determination of 22 typical pharmaceuticals and personal care products in environmental water using ultra performance liquid chromatography- triple quadrupole mass spectrometry].

PubMed

Wu, Chunying; Gu, Feng; Bai, Lu; Lu, Wenlong

2015-08-01

An analytical method for simultaneous determination of 22 typical pharmaceuticals and personal care products (PPCPs) in environmental water samples was developed by ultra performance liquid chromatography-triple quadrupole mass spectrometry (UPLC-MS/MS). An Oasis HLB solid phase extraction cartridge, methanol as washing solution, water containing 0. 1% formic acid-methanol (7:3, v/v) as the mobile phases were selected for sample pretreatment and chromatographic separation. Based on the optimized sample pretreatment procedures and separation condition, the target recoveries ranged from 73% to 125% in water with the relative standard deviations ( RSDs) from 8.8% to 17.5%, and the linear ranges were from 2 to 2 000 µg/L with correlation coefficients (R2) not less than 0.997. The method can be applied to simultaneous determination of the 22 typical PPCPs in environmental water samples because of its low detection limits and high recoveries. It can provide support and help for the related research on water environmental risk assessment and control of the micro-organic pollutants.

A biodegradable colorimetric film for rapid low-cost field determination of formaldehyde contamination by digital image colorimetry.

PubMed

Wongniramaikul, Worawit; Limsakul, Wadcharawadee; Choodum, Aree

2018-05-30

A biodegradable colorimetric film was fabricated on the lid of portable tube for in-tube formaldehyde detection. Based on the entrapment of colorimetric reagents within a thin film of tapioca starch, the yellow reaction product was observed with formaldehyde. Intensity of the blue channel from the digital image of yellow product showed a linear relationship in the range of 0-25 mg L -1 with low detection limit of 0.7 ± 0.1 mg L -1 . Inter-day precision of 0.61-3.10%RSD were obtained with less than 4.2% relative error from control samples. The developed method was applied for various food samples in Phuket and formaldehyde concentration range was non-detectable to 1.413 mg kg -1 . The quantified concentrations of formaldehyde in fish and squid samples provided relative errors of -7.7% and +10.8% compared to spectrophotometry. This low cost sensor (∼0.04 USD/test) with digital image colorimetry was thus an effective alternative for formaldehyde detection in food sample. Copyright © 2018 Elsevier Ltd. All rights reserved.

Internally Controlled, Multiplex Real-Time Reverse Transcription PCR for Dengue Virus and Yellow Fever Virus Detection.

PubMed

Rojas, Alejandra; Diagne, Cheikh T; Stittleburg, Victoria D; Mohamed-Hadley, Alisha; de Guillén, Yvalena Arévalo; Balmaseda, Angel; Faye, Oumar; Faye, Ousmane; Sall, Amadou A; Harris, Eva; Pinsky, Benjamin A; Waggoner, Jesse J

2018-04-02

The differential diagnosis of dengue virus (DENV) and yellow fever virus (YFV) infections in endemic areas is complicated by nonspecific early clinical manifestations. In this study, we describe an internally controlled, multiplex real-time reverse transcription PCR (rRT-PCR) for the detection of DENV and YFV. The DENV-YFV assay demonstrated specific detection and had a dynamic range of 2.0-8.0 log 10 copies/μL of eluate for each DENV serotype and YFV. Clinical performance was similar to a published pan-DENV assay: 48/48 acute-phase samples from dengue cases were detected in both assays. For YFV detection, mock samples were prepared with nine geographically diverse YFV isolates over a range of concentrations. The DENV-YFV assay detected 62/65 replicates, whereas 54/65 were detected using a reference YFV rRT-PCR. Given the reemergence of DENV and YFV in areas around the world, the DENV-YFV assay should be a useful tool to narrow the differential diagnosis and provide early case detection.

Direct determination of cadmium in foods by solid sampling electrothermal vaporization inductively coupled plasma mass spectrometry using a tungsten coil trap

NASA Astrophysics Data System (ADS)

Zhang, Ying; Mao, Xuefei; Liu, Jixin; Wang, Min; Qian, Yongzhong; Gao, Chengling; Qi, Yuehan

2016-04-01

In this work, a solid sampling device consisting of a tungsten coil trap, porous carbon vaporizer and on-line ashing furnace of a Ni-Cr coil was interfaced with inductively coupled plasma mass spectrometry (ICP-MS). A modified double gas circuit system was employed that was composed of carrier and supplemental gas lines controlled by separate gas mass flow controllers. For Cd determination in food samples using the assembled solid sampling ICP-MS, the optimal ashing and vaporization conditions, flow rate of the argon-hydrogen (Ar/H2) (v:v = 24:1) carrier gas and supplemental gas, and minimum sampling mass were investigated. Under the optimized conditions, the limit of quantification was 0.5 pg and the relative standard deviation was within a 10.0% error range (n = 10). Furthermore, the mean spiked recoveries for various food samples were 99.4%-105.9% (n = 6). The Cd concentrations measured by the proposed method were all within the certified values of the reference materials or were not significantly different (P > 0.05) from those of the microwave digestion ICP-MS method, demonstrating the good accuracy and precision of the solid sampling ICP-MS method for Cd determination in food samples.

Health-hazard evaluation report HETA 83-391-1683, Continental Coffee Products Company, Houston, Texas

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

Arnold, S.J.; Markel, H.L.; Morawetz, J.S.

1986-04-01

The International Chemical Workers Union requested an evaluation be made of the health status of employees at the Continental Coffee Products Company, Houston, Texas with particular attention given to potential exposure to pesticide residues on imported coffee beans. Analysis of air samples revealed the following concentration ranges: 29 personal respirable-dust samples ranging from 0.03 to 2.03 milligrams/cubic meter (mg/m3); 27 of 28 personal total dust samples, 0.09 to 2.65 mg/m3; four area respirable-dust samples, 0.11 to 0.53 mg/m3; and four area total dust samples, 0.16 to 2.39 mg/m3. Pesticide exposures were significantly below acceptable daily intakes. The authors conclude thatmore » it would not be expected that employees would be exposed to pesticide levels posing an appreciable threat to health. Recommendations were made to increase the use of local exhaust ventilation; to improve work practices to reduce generation of dust and accumulation; increase ventilation in the basement re-mix operation; and train employees toward the understanding of potential hazards and their role in controlling dust.« less

Determination of total sulfur content of sedimentary rocks by a combustion method

USGS Publications Warehouse

Coller, M.E.; Leininger, R.K.

1955-01-01

Total sulfur has been determined in common sedimentary rocks by a combustion method. Sulfur contents range from 0.001 to 5.0%. Experiments show that the combustion method can be used in analyzing sedimentary rocks in which sulfur is present as sulfide, sulfate, or both. Pulverized samples from 0.100 to 0.500 gram in weight are used in this method. Each sample is placed in a No. 6 Leco combustion boat and covered with two fluxes: 0.50 gram of standard ingot iron and approximately 1.0 gram of 30-mesh granular tin. The boat with sample then is placed in the combustion tube of a Burrell Unit Package Model T29A tube furnace which is controlled at a temperature of 1310?? to 1320?? C. After the sample has been heated for 1 minute, oxygen is admitted at a rate of about 1 liter per minute. The sulfur dioxide formed is absorbed in a starch solution and is titrated with standard potassium iodate in a Leco sulfur determinator. Thirteen values obtained for National Bureau of Standards standard sample 1a, argillaceous limestone, range from 0.273 to 0.276% sulfur (certificate value 0.27% by calculation).

Are There Scenarios When the Use of Non-Placebo-Control Groups in Experimental Trial Designs Increase Expected Value to Society?

PubMed

Uyei, Jennifer; Braithwaite, R Scott

2016-01-01

Despite the benefits of the placebo-controlled trial design, it is limited by its inability to quantify total benefits and harms. Such trials, for example, are not designed to detect an intervention's placebo or nocebo effects, which if detected could alter the benefit-to-harm balance and change a decision to adopt or reject an intervention. In this article, we explore scenarios in which alternative experimental trial designs, which differ in the type of control used, influence expected value across a range of pretest assumptions and study sample sizes. We developed a decision model to compare 3 trial designs and their implications for decision making: 2-arm placebo-controlled trial ("placebo-control"), 2-arm intervention v. do nothing trial ("null-control"), and an innovative 3-arm trial design: intervention v. do nothing v. placebo trial ("novel design"). Four scenarios were explored regarding particular attributes of a hypothetical intervention: 1) all benefits and no harm, 2) no biological effect, 3) only biological effects, and 4) surreptitious harm (no biological benefit or nocebo effect). Scenario 1: When sample sizes were very small, the null-control was preferred, but as sample sizes increased, expected value of all 3 designs converged. Scenario 2: The null-control was preferred regardless of sample size when the ratio of placebo to nocebo effect was >1; otherwise, the placebo-control was preferred. Scenario 3: When sample size was very small, the placebo-control was preferred when benefits outweighed harms, but the novel design was preferred when harms outweighed benefits. Scenario 4: The placebo-control was preferred when harms outweighed placebo benefits; otherwise, preference went to the null-control. Scenarios are hypothetical, study designs have not been tested in a real-world setting, blinding is not possible in all designs, and some may argue the novel design poses ethical concerns. We identified scenarios in which alternative experimental study designs would confer greater expected value than the placebo-controlled trial design. The likelihood and prevalence of such situations warrant further study. © The Author(s) 2015.

Hemoglobin adducts as biomarkers of 1,3-butadiene in occupationally low exposed Italian workers and a few diesel-exposed miners.

PubMed

Begemann, P; Upton, P B; Ranasinghe, A; Swenberg, J A; Soleo, L; Vimercati, L; Gelormini, A; Fustinoni, S; Zwirner-Baier, I; Neumann, H G

2001-06-01

Hemoglobin adducts were determined as biomarkers of 1,3-butadiene (BD) in 30 workers and 10 controls from an Italian BD plant and in 14 diesel-exposed miners. N-(2,3,4-trihydroxybutyl)valine (THBVal), an N-terminal valine globin adduct of reactive butadiene metabolites, was analyzed by gas chromatography/high resolution mass spectrometry after a modified Edman degradation and further acetylation. The BD exposure for the plant workers was 31 microg/m(3) (personal sampling). Whereas there was no detectable difference in hemoglobin adduct levels (range 17.7-61.4 pmol/g globin) between the total group of exposed and controls, slight but significant differences could be found between two subgroups of workers from different production units as well as one subgroup and controls (P<0.05), between smoking (n=13) and non-smoking exposed workers (n=17; P=0.066) as well as between smoking exposed workers and controls (P=0.055). Adduct levels of the miners (all non-smokers) were in the same range as those of the Italian BD-workers and controls. The internal exposure and strain measured by THBVal levels resulting from a very low occupational BD exposure was in the range of the contribution of moderate smoking.

Assessment of breadmaking performance of wheat flour dough by means of frequency dependent ultrasound

NASA Astrophysics Data System (ADS)

Braunstein, D.; Page, J. H.; Strybulevych, A.; Peressini, D.; Scanlon, M. G.

2012-12-01

Technological performance of wheat flour varies among different wheat varieties. Gluten plays a key role within the solid phase of dough in the formation and the retention of gas bubbles during breadmaking. Rheological tests are usually performed to predict breadmaking potential. The aim here was to investigate the ability of ultrasound to discriminate wheat doughs based on breadmaking qualities. The ultimate goal is the development of an online quality control system currently unavailable in the baked goods industry, rendering this work innovative. Samples were prepared from a strong wheat flour, with one control sample and one added with inulin and distilled monoglycerides, producing doughs of distinct breadmaking quality. Doughs were subjected to density determination, elongation tests, and ultrasound analysis. The ultrasound tests were performed in the frequency range of 300 kHz - 6 MHz. Ultrasonic phase velocity increased with increasing frequency to about 2 MHz, becoming constant and then decreasing from 3 MHz for the control sample. Distinct differences in attenuation coefficient between the fibre-enriched and control doughs were observed. Ultrasound can potentially add to a better understanding of dough quality and can discriminate between doughs of contrasting properties.

Droplet digital polymerase chain reaction (ddPCR) assays integrated with an internal control for quantification of bovine, porcine, chicken and turkey species in food and feed

PubMed Central

Shehata, Hanan R.; Li, Jiping; Redda, Helen; Cheng, Shumei; Tabujara, Nicole; Li, Honghong; Warriner, Keith; Hanner, Robert

2017-01-01

Food adulteration and feed contamination are significant issues in the food/feed industry, especially for meat products. Reliable techniques are needed to monitor these issues. Droplet Digital PCR (ddPCR) assays were developed and evaluated for detection and quantification of bovine, porcine, chicken and turkey DNA in food and feed samples. The ddPCR methods were designed based on mitochondrial DNA sequences and integrated with an artificial recombinant plasmid DNA to control variabilities in PCR procedures. The specificity of the ddPCR assays was confirmed by testing both target species and additional 18 non-target species. Linear regression established a detection range between 79 and 33200 copies of the target molecule from 0.26 to 176 pg of fresh animal tissue DNA with a coefficient of determination (R2) of 0.997–0.999. The quantification ranges of the methods for testing fortified heat-processed food and feed samples were 0.05–3.0% (wt/wt) for the bovine and turkey targets, and 0.01–1.0% (wt/wt) for pork and chicken targets. Our methods demonstrated acceptable repeatability and reproducibility for the analytical process for food and feed samples. Internal validation of the PCR process was monitored using a control chart for 74 consecutive ddPCR runs for quantifying bovine DNA. A matrix effect was observed while establishing calibration curves with the matrix type under testing, and the inclusion of an internal control in DNA extraction provides a useful means to overcome this effect. DNA degradation caused by heating, sonication or Taq I restriction enzyme digestion was found to reduce ddPCR readings by as much as 4.5 fold. The results illustrated the applicability of the methods to quantify meat species in food and feed samples without the need for a standard curve, and to potentially support enforcement activities for food authentication and feed control. Standard reference materials matching typical manufacturing processes are needed for future validation of ddPCR assays for absolute quantification of meat species. PMID:28796824

Droplet digital polymerase chain reaction (ddPCR) assays integrated with an internal control for quantification of bovine, porcine, chicken and turkey species in food and feed.

PubMed

Shehata, Hanan R; Li, Jiping; Chen, Shu; Redda, Helen; Cheng, Shumei; Tabujara, Nicole; Li, Honghong; Warriner, Keith; Hanner, Robert

2017-01-01

Food adulteration and feed contamination are significant issues in the food/feed industry, especially for meat products. Reliable techniques are needed to monitor these issues. Droplet Digital PCR (ddPCR) assays were developed and evaluated for detection and quantification of bovine, porcine, chicken and turkey DNA in food and feed samples. The ddPCR methods were designed based on mitochondrial DNA sequences and integrated with an artificial recombinant plasmid DNA to control variabilities in PCR procedures. The specificity of the ddPCR assays was confirmed by testing both target species and additional 18 non-target species. Linear regression established a detection range between 79 and 33200 copies of the target molecule from 0.26 to 176 pg of fresh animal tissue DNA with a coefficient of determination (R2) of 0.997-0.999. The quantification ranges of the methods for testing fortified heat-processed food and feed samples were 0.05-3.0% (wt/wt) for the bovine and turkey targets, and 0.01-1.0% (wt/wt) for pork and chicken targets. Our methods demonstrated acceptable repeatability and reproducibility for the analytical process for food and feed samples. Internal validation of the PCR process was monitored using a control chart for 74 consecutive ddPCR runs for quantifying bovine DNA. A matrix effect was observed while establishing calibration curves with the matrix type under testing, and the inclusion of an internal control in DNA extraction provides a useful means to overcome this effect. DNA degradation caused by heating, sonication or Taq I restriction enzyme digestion was found to reduce ddPCR readings by as much as 4.5 fold. The results illustrated the applicability of the methods to quantify meat species in food and feed samples without the need for a standard curve, and to potentially support enforcement activities for food authentication and feed control. Standard reference materials matching typical manufacturing processes are needed for future validation of ddPCR assays for absolute quantification of meat species.

Identification of Sources of Endotoxin Exposure as Input for Effective Exposure Control Strategies.

PubMed

van Duuren-Stuurman, Birgit; Gröllers-Mulderij, Mariska; van de Runstraat, Annemieke; Duisterwinkel, Anton; Terwoert, Jeroen; Spaan, Suzanne

2018-02-13

Aim of the present study is to investigate the levels of endotoxins on product samples from potatoes, onions, and seeds, representing a relevant part of the agro-food industry in the Netherlands, to gather valuable insights in possibilities for exposure control measures early in the process of industrial processing of these products. Endotoxin levels on 330 products samples from companies representing the potato, onion, and seed (processing) industry (four potato-packaging companies, five potato-processing companies, five onion-packaging companies, and four seed-processing companies) were assessed using the Limulus Amboecyte Lysate (LAL) assay. As variation in growth conditions (type of soil, growth type) and product characteristics (surface roughness, dustiness, size, species) are assumed to influence the level of endotoxin on products, different types, and growth conditions were considered when collecting the samples. Additionally, waste material, rotten products, felt material (used for drying), and process water were collected. A large variation in the endotoxin levels was found on samples of potatoes, onions, and seeds (overall geometric standard deviation 17), in the range between 0.7 EU g-1 to 16400000 EU g-1. The highest geometric mean endotoxin levels were found in plant material (319600 EU g-1), followed by soil material (49100 EU g-1) and the outer side of products (9300 EU g-1), indicating that removal of plant and soil material early in the process would be an effective exposure control strategy. The high levels of endotoxins found in the limited number of samples from rotten onions indicate that these rotten onions should also be removed early in the process. Mean endotoxin levels found in waste material (only available for seed processing) is similar to the level found in soil material, although the range is much larger. On uncleaned seeds, higher endotoxin levels were found than on cleaned seeds, indicating that cleaning processes are important control measures and also that the waste material should be handled with care. Although endotoxin levels in batches of to-be-processed potatoes, onions, and seeds vary quite dramatically, it could be concluded that rotten products, plant material, and waste material contain particularly high endotoxin levels. This information was used to propose control measures to reduce exposure to endotoxins of workers during the production process. © The Author(s) 2017. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.

Serum and urine chromium as indices of chromium status in tannery workers

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

Randall, J.A.; Gibson, R.S.

Serum and urinary Cr levels of a selected group of men exposed to CrIII in four Southern Ontario tanneries were compared with those of men not exposed to Cr. Fasted blood samples were obtained from 72 tannery workers (TW; mean age +/- SD = 36 +/- 12 years) and from 52 controls (CS; mean age +/- SD = 41 +/- 13 years). Serum Cr levels as determined by graphite furnace atomic absorption spectrophotometry were significantly higher (P = 0.0001) for TW (median 0.49 ng/ml, range 0.37-0.81) than for CS (median 0.15 ng/ml, range 0.12-0.20). Urine samples were collected from 49more » TW and 43 CS on a Friday pm and from 42 TW on a Monday am. Urinary creatine (Cre) was determined by the Jaffe reaction. For Friday samples, the median urinary Cr/Cre ratio was significantly higher (P = 0.0001) for TW (median 0.83 ng/mg, range 0.48-1.82) than for CS (median 0.18 ng/mg, range 0.13-0.26). For TW, Cr/Cre was correlated with serum Cr (r = 0.72, P = 0.0001). Neither urinary Cr/Cre nor serum Cr was correlated with length of employment in the tanning industry. There were significant differences in serum Cr levels and urinary Cr/Cre ratios among TW employed in different areas of the tanneries. For TW, the median urinary Cr/Cre ratio for Monday morning samples was significantly lower than for Friday afternoon samples (P = 0.03). These data indicate that CrIII is absorbed and that serum and urine Cr in tannery workers may be indices of Cr exposure and status.« less

Serum and urine chromium as indices of chromium status in tannery workers.

PubMed

Randall, J A; Gibson, R S

1987-05-01

Serum and urinary Cr levels of a selected group of men exposed to CrIII in four Southern Ontario tanneries were compared with those of men not exposed to Cr. Fasted blood samples were obtained from 72 tannery workers (TW; mean age +/- SD = 36 +/- 12 years) and from 52 controls (CS; mean age +/- SD = 41 +/- 13 years). Serum Cr levels as determined by graphite furnace atomic absorption spectrophotometry were significantly higher (P = 0.0001) for TW (median 0.49 ng/ml, range 0.37-0.81) than for CS (median 0.15 ng/ml, range 0.12-0.20). Urine samples were collected from 49 TW and 43 CS on a Friday pm and from 42 TW on a Monday am. Urinary creatine (Cre) was determined by the Jaffe reaction. For Friday samples, the median urinary Cr/Cre ratio was significantly higher (P = 0.0001) for TW (median 0.83 ng/mg, range 0.48-1.82) than for CS (median 0.18 ng/mg, range 0.13-0.26). For TW, Cr/Cre was correlated with serum Cr (r = 0.72, P = 0.0001). Neither urinary Cr/Cre nor serum Cr was correlated with length of employment in the tanning industry. There were significant differences in serum Cr levels and urinary Cr/Cre ratios among TW employed in different areas of the tanneries. For TW, the median urinary Cr/Cre ratio for Monday morning samples was significantly lower than for Friday afternoon samples (P = 0.03). These data indicate that CrIII is absorbed and that serum and urine Cr in tannery workers may be indices of Cr exposure and status.

STS 132 Return Samples: Assessment of Air Quality Aboard the Shuttle (STS-132) and International Space Station (ULF4)

NASA Technical Reports Server (NTRS)

James. John T.

2010-01-01

The toxicological assessments of 2 grab sample canisters (GSCs) from the Shuttle are reported. Analytical methods have not changed from earlier reports. The recoveries of the 3 surrogates (13C-acetone, fluorobenzene, and chlorobenzene) from the 2 Shuttle GSCs averaged 93, 85%, and 88%, respectively. Based on the end-of-mission sample, the Shuttle atmosphere was acceptable for human respiration. The toxicological assessment of 7 GSCs from the ISS is also shown. The recoveries of the 3 standards (as listed above) from the GSCs averaged 78, 96 and 90%, respectively. Recovery from formaldehyde control badges ranged from 90 to 112%.

Controlled in situ boron doping of diamond thin films using solution phase

NASA Astrophysics Data System (ADS)

Roy, M.; Dua, A. K.; Nuwad, J.; Girija, K. G.; Tyagi, A. K.; Kulshreshtha, S. K.

2006-12-01

Controlled boron doping of diamond film using nontoxic reagents is a challenge in itself. During the present study, attempts have been made to dope diamond films in situ with boron from a solution of boric acid (H3BO3) in methanol (CH3OH) using a specially designed bubbler that ensured continuous and controlled flow of vapors of boron precursors during deposition. The samples are thoroughly characterized using a host of techniques comprising of x-ray photoelectron spectroscopy, Raman, x-ray diffraction, and current-voltage measurements (I-V). Cross-sectional micro-Raman spectroscopy has been used to obtain depth profile of boron in diamond films. Boron concentration ([B]) in the films is found to vary linearly on a semilog scale with molarity (M) of H3BO3 in CH3OH. Lattice constant of our samples is smaller than the reported American society for testing and materials (ASTM) values due to oxygen incorporation and it increases with [B] in the diamond samples. Heavily boron doped samples exhibit Fano deformation of the Raman line shape and negative and/zero activation barrier in temperature dependent I-V measurements that indicate the formation of metallic phase in the samples. The present study illustrates the feasibility of safe and controlled boron doping of diamond films using a solution of H3BO3 in CH3OH over a significant range of [B] from semiconductor to metallic regime but with a little adverse effect due to unintentional but unavoidable incorporation of oxygen.

Reading, Mathematics, and Behavioral Difficulties Interrelate: Evidence from a Cross-lagged Panel Design and Population-based Sample

PubMed Central

Lin, Yu-Chu; Morgan, Paul L.; Farkas, George; Hillemeier, Marianne; Cook, Michael

2015-01-01

We examined three questions. First, do reading difficulties increase children’s risk of behavior difficulties? Second, do behavioral difficulties increase children’s risk of reading difficulties? Third, do mathematics difficulties increase children’s risk of reading or behavioral difficulties? We investigated these questions using a sample of 9,324 children followed from third to fifth grade as they participated in a nationally representative dataset, conducting multilevel logistic regression modeling and including statistical control for many potential confounds. Results indicated that poor readers in third grade were significantly more likely to display poor task management, poor self-control, poor interpersonal skills, internalizing behavior problems, and externalizing behavior problems in fifth grade (odds ratio [OR] range = 1.30 – 1.57). Statistically controlling for a prior history of reading difficulties, children with poor mathematics skills in third grade were also significantly more likely to display poor task management, poor interpersonal skills, internalizing behavior problems, and reading difficulties in fifth grade (OR range = 1.38 – 5.14). In contrast, only those children exhibiting poor task management, but not other types of problem behaviors, in third grade were more likely to be poor readers in fifth grade (OR = 1.49). PMID:26097274

High Precision Motion Control System for the Two-Stage Light Gas Gun at the Dynamic Compression Sector

NASA Astrophysics Data System (ADS)

Zdanowicz, E.; Guarino, V.; Konrad, C.; Williams, B.; Capatina, D.; D'Amico, K.; Arganbright, N.; Zimmerman, K.; Turneaure, S.; Gupta, Y. M.

2017-06-01

The Dynamic Compression Sector (DCS) at the Advanced Photon Source (APS), located at Argonne National Laboratory (ANL), has a diverse set of dynamic compression drivers to obtain time resolved x-ray data in single event, dynamic compression experiments. Because the APS x-ray beam direction is fixed, each driver at DCS must have the capability to move through a large range of linear and angular motions with high precision to accommodate a wide variety of scientific needs. Particularly challenging was the design and implementation of the motion control system for the two-stage light gas gun, which rests on a 26' long structure and weighs over 2 tons. The target must be precisely positioned in the x-ray beam while remaining perpendicular to the gun barrel axis to ensure one-dimensional loading of samples. To accommodate these requirements, the entire structure can pivot through 60° of angular motion and move 10's of inches along four independent linear directions with 0.01° and 10 μm resolution, respectively. This presentation will provide details of how this system was constructed, how it is controlled, and provide examples of the wide range of x-ray/sample geometries that can be accommodated. Work supported by DOE/NNSA.

Testing of typical spacecraft materials in a simulated substorm environment

NASA Technical Reports Server (NTRS)

Stevens, N. J.; Berkopec, F. D.; Staskus, J. V.; Blech, R. A.; Narciso, S. J.

1977-01-01

The test specimens were spacecraft paints, silvered Teflon, thermal blankets, and solar array segments. The samples, ranging in size from 300 to 1000 sq cm were exposed to monoenergetic electron energies from 2 to 20 keV at a current density of 1 NA/sq cm. The samples generally behaved as capacitors with strong voltage gradient at their edges. The charging characteristics of the silvered Teflon, Kapton, and solar cell covers were controlled by the secondary emission characteristics. Insulators that did not discharge were the spacecraft paints and the quartz fiber cloth thermal blanket sample. All other samples did experience discharges when the surface voltage reached -8 to -16kV. The discharges were photographed. The breakdown voltage for each sample was determined and the average energy lost in the discharge was computed.

Enhanced atomic gas fractions in recently merged galaxies: quenching is not a result of post-merger gas exhaustion.

NASA Astrophysics Data System (ADS)

Ellison, Sara L.; Catinella, Barbara; Cortese, Luca

2018-05-01

We present a detailed assessment of the global atomic hydrogen gas fraction (fgas=log[MHI/M⋆]) in a sample of post-merger galaxies identified in the Sloan Digital Sky Survey (SDSS). Archival H I measurements of 47 targets are combined with new Arecibo observations of a further 51 galaxies. The stellar mass range of the post-merger sample, our observing strategy, detection thresholds and data analysis procedures replicate those of the extended GALEX Arecibo SDSS Survey (xGASS) which can therefore be used as a control sample. Our principal results are: 1) The post-merger sample shows a ˜ 50 per cent higher H I detection fraction compared with xGASS; 2) Accounting for non-detections, the median atomic gas fraction of the post-merger sample is larger than the control sample by 0.3 - 0.6 dex; 3) The median atomic gas fraction enhancement (Δfgas), computed on a galaxy-by-galaxy basis at fixed stellar mass, is 0.51 dex. Our results demonstrate that recently merged galaxies are typically a factor of ˜ 3 more H I rich than control galaxies of the same M⋆. If the control sample is additionally matched in star formation rate, the median H I excess is reduced to Δfgas = 0.2 dex, showing that the enhanced atomic gas fractions in post-mergers are not purely a reflection of changes in star formation activity. We conclude that merger-induced starbursts and outflows do not lead to prompt quenching via exhaustion/expulsion of the galactic gas reservoirs. Instead, we propose that if star formation ceases after a merger, it is more likely due to an enhanced turbulence which renders the galaxy unable to effectively form new stars.

Midstream clean-catch urine collection in newborns: a randomized controlled study.

PubMed

Altuntas, Nilgun; Tayfur, Asli Celebi; Kocak, Mesut; Razi, Hasan Cem; Akkurt, Serpil

2015-05-01

We aimed to evaluate a recently defined technique based on bladder stimulation and paravertebral lumbar massage maneuvers in collecting a midstream clean-catch urine sample in newborns. A total of 127 term newborns were randomly assigned either to the experimental group or the control group. Twenty-five minutes after feeding, the genital and perineal areas of the babies were cleaned. The babies were held under the armpits with legs dangling. Bladder stimulation and lumbar paravertebral massage maneuvers were only applied to the babies in the experimental group. Success was defined as collection of a urine sample within 5 min of starting the stimulation maneuvers in the experimental group and of holding under the armpits in the control group. The success rate of urine collection was significantly higher in the experimental group (78%) than in the control group (33%; p < 0.001). The median time (interquartile range) for sample collection was 60 s (64.5 s) in the experimental group and 300 s (95 s) in the control group (p < 0.0001). Contamination rates were similar in both groups (p = 0.770). We suggest that bladder stimulation and lumbar paravertebral massage is a safe, quick, and effective way of collecting midstream clean-catch urine in newborns.

Physical fitness reference standards in fibromyalgia: The al-Ándalus project.

PubMed

Álvarez-Gallardo, I C; Carbonell-Baeza, A; Segura-Jiménez, V; Soriano-Maldonado, A; Intemann, T; Aparicio, V A; Estévez-López, F; Camiletti-Moirón, D; Herrador-Colmenero, M; Ruiz, J R; Delgado-Fernández, M; Ortega, F B

2017-11-01

We aimed (1) to report age-specific physical fitness levels in people with fibromyalgia of a representative sample from Andalusia; and (2) to compare the fitness levels of people with fibromyalgia with non-fibromyalgia controls. This cross-sectional study included 468 (21 men) patients with fibromyalgia and 360 (55 men) controls. The fibromyalgia sample was geographically representative from southern Spain. Physical fitness was assessed with the Senior Fitness Test battery plus the handgrip test. We applied the Generalized Additive Model for Location, Scale and Shape to calculate percentile curves for women and fitted mean curves using a linear regression for men. Our results show that people with fibromyalgia reached worse performance in all fitness tests than controls (P < 0.001) in all age ranges (P < 0.001). This study provides a comprehensive description of age-specific physical fitness levels among patients with fibromyalgia and controls in a large sample of patients with fibromyalgia from southern of Spain. Physical fitness levels of people with fibromyalgia from Andalusia are very low in comparison with age-matched healthy controls. This information could be useful to correctly interpret physical fitness assessments and helping health care providers to identify individuals at risk for losing physical independence. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

A laboratory assessment of the Waveband Integrated Bioaerosol Sensor (WIBS-4) using individual samples of pollen and fungal spore material

NASA Astrophysics Data System (ADS)

Healy, David A.; O'Connor, David J.; Burke, Aoife M.; Sodeau, John R.

2012-12-01

A Bioaerosol sensing instrument referred to as WIBS-4, designed to continuously monitor ambient bioaerosols on-line, has been used to record a multiparameter “signature” from each of a number of Primary Biological Aerosol Particulate (PBAP) samples found in air. These signatures were obtained in a controlled laboratory environment and are based on the size, asymmetry (“shape”) and auto-fluorescence of the particles. Fifteen samples from two separate taxonomic ranks (kingdoms), Plantae (×8) and Fungi (×7) were individually introduced to the WIBS-4 for measurement along with two non-fluorescing chemical solids, common salt and chalk. Over 2000 individual-particle measurements were recorded for each sample type and the ability of the WIBS spectroscopic technique to distinguish between chemicals, pollen and fungal spore material was examined by identifying individual PBAP signatures. The results obtained show that WIBS-4 could potentially be a very useful analytical tool for distinguishing between natural airborne PBAP samples, such as the fungal spores and may potentially play an important role in detecting and discriminating the toxic fungal spore, Aspergillus fumigatus, from others in real-time. If the sizing range of the commercial instrument was customarily increased and permitted to operate simultaneously in its two sizing ranges, pollen and spores could potentially be discriminated between. The data also suggest that the gain setting sensitivity on the detector would also have to be reduced by a factor >5, to routinely detect, in-range fluorescence measurements for pollen samples.

Ethane C-C clumping in natural gas : a proxy for cracking processes ?

NASA Astrophysics Data System (ADS)

Clog, M. D.; Ferreira, A. A.; Santos Neto, E. V.; Eiler, J. M.

2014-12-01

Ethane (C2H6) is the second-most abundant alkane in most natural gas reservoirs, and is used to produce ethylene for petrochemical industries. It is arguably the simplest molecule that can manifest multiple 13C substitutions. There are several plausible controls on Δ13C2H6in natural gas: thermodynamically controlled homogeneous isotope exchange reactions analogous to those behind carbonate clumped isotope thermometry; inheritance from larger biomolecules that undergo thermal degradation to produce natural gas; mixing of natural gases that differ markedly in bulk isotopic composition; diffusive fractionation; or combinations of these and/or other, less expected fractionations. There is little basis for predicting which of these will control isotopic variations among natural ethanes, but we think it likely that addition of this new isotopic proxy will reveal new insights into the natural chemistry of ethane. We have developed a method to measure the abundance of 13C2H6 in natural samples, using high-resolution mass spectrometry. We define Δ13C2H6 as 1000 . ((13C2H6/12C2H6)measured/(13C2H6/12C2H6)stochastic -1). We studied several suites of natural gas samples and experimentally produced or modified ethane. Natural ethanes, including closely related samples from a single natural gas field, exhibit surprisingly large ranges in Δ13C2H6 (4 ‰ overall; up to 3 ‰ in one gas field). Such ranges cannot be explained by thermodynamic equilibrium at a range of different temperatures, or by diffusive fractionation. Kinetic isotope effects associated with 'cracking' reactions, and/or inheritance of non-equilibrium carbon isotope structures from source organics are more likely causes. We observe a correlation between Δ13C2H6 and the concentration of alkanes other than methane in several suites of natural gases, suggesting the causes of clumped isotope variations are tied to the controls on gas wetness. An experiment examining ethane residual to high-temperature pyrolysis confirms this trend could be an isotopic fingerprint for ethane destruction.

Quality-Assurance Data for Routine Water Analyses by the U.S. Geological Survey Laboratory in Troy, New York - July 2001 Through June 2003

USGS Publications Warehouse

Lincoln, Tricia A.; Horan-Ross, Debra A.; McHale, Michael R.; Lawrence, Gregory B.

2009-01-01

The laboratory for analysis of low-ionic-strength water at the U.S. Geological Survey (USGS) Water Science Center in Troy, N.Y., analyzes samples collected by USGS projects throughout the Northeast. The laboratory's quality-assurance program is based on internal and interlaboratory quality-assurance samples and quality-control procedures that were developed to ensure proper sample collection, processing, and analysis. The quality-assurance and quality-control data were stored in the laboratory's Lab Master data-management system, which provides efficient review, compilation, and plotting of data. This report presents and discusses results of quality-assurance and quality control samples analyzed from July 2001 through June 2003. Results for the quality-control samples for 19 analytical procedures were evaluated for bias and precision. Control charts indicate that data for six of the analytical procedures were occasionally biased for either high-concentration or low-concentration samples but were within control limits; these procedures were: acid-neutralizing capacity, chloride, magnesium, nitrate (ion chromatography), potassium, and sodium. The calcium procedure was biased throughout the analysis period for the high-concentration sample, but was within control limits. The total monomeric aluminum and fluoride procedures were biased throughout the analysis period for the low-concentration sample, but were within control limits. The total aluminum, pH, specific conductance, and sulfate procedures were biased for the high-concentration and low-concentration samples, but were within control limits. Results from the filter-blank and analytical-blank analyses indicate that the procedures for 16 of 18 analytes were within control limits, although the concentrations for blanks were occasionally outside the control limits. The data-quality objective was not met for the dissolved organic carbon or specific conductance procedures. Sampling and analysis precision are evaluated herein in terms of the coefficient of variation obtained for triplicate samples in the procedures for 18 of the 21 analytes. At least 90 percent of the samples met data-quality objectives for all procedures except total monomeric aluminum (83 percent of samples met objectives), total aluminum (76 percent of samples met objectives), ammonium (73 percent of samples met objectives), dissolved organic carbon (86 percent of samples met objectives), and nitrate (81 percent of samples met objectives). The data-quality objective was not met for the nitrite procedure. Results of the USGS interlaboratory Standard Reference Sample (SRS) Project indicated satisfactory or above data quality over the time period, with most performance ratings for each sample in the good-to-excellent range. The N-sample (nutrient constituents) analysis had one unsatisfactory rating for the ammonium procedure in one study. The T-sample (trace constituents) analysis had one unsatisfactory rating for the magnesium procedure and one marginal rating for the potassium procedure in one study and one unsatisfactory rating for the sodium procedure in another. Results of Environment Canada's National Water Research Institute (NWRI) program indicated that at least 90 percent of the samples met data-quality objectives for 10 of the 14 analytes; the exceptions were acid-neutralizing capacity, ammonium, dissolved organic carbon, and sodium. Data-quality objectives were not met in 37 percent of samples analyzed for acid-neutralizing capacity, 28 percent of samples analyzed for dissolved organic carbon, and 30 percent of samples analyzed for sodium. Results indicate a positive bias for the ammonium procedure in one study and a negative bias in another. Results from blind reference-sample analyses indicated that data-quality objectives were met by at least 90 percent of the samples analyzed for calcium, chloride, magnesium, pH, potassium, and sodium. Data-quality objectives were met by 78 percent of

Monitoring mercury in two South African herbaria.

PubMed

Kataeva, Maria; Panichev, Nikolay; van Wyk, Abraham E

2009-01-15

Mercury [Hg] emissions from old plant collections treated with mercuric chloride (HgCl(2)) may present a high health risk for staff working in certain herbaria. The present study evaluated Hg concentrations in ambient air, plant specimens and biological samples from staff working in the Pretoria National Herbarium (PRE) and the H.G.W.J. Schweickerdt Herbarium (PRU), University of Pretoria. Biological samples from a group of 15 people exposed to HgCl(2) in herbaria and a non-exposed control group of five people were studied. Additionally, plant samples from herbarium specimens treated and non-treated with HgCl(2) were analysed. Plant materials treated with HgCl(2) had persistent high concentrations of Hg in the range of 114-432 microg g(-1), whereas untreated materials were in the range of 0.20-0.45 microg g(-1). The HgCl(2)-treated plant specimens induced elevated concentrations of Hg into the herbarium rooms near storage cabinets, where up to 1 microg m(-3) of Hg was measured in the air of both herbaria. However, no significant difference in mean Hg concentrations in hair was found between herbarium workers and members of the control group, 0.46 and 0.64 microg g(-1) respectively (p0.05, Student's t-test). For both groups, Hg concentrations were lower than that indicated by the World Health Organization [WHO] for non-exposed adults, namely 2 microg g(-1). The mean concentration of total Hg in urine from the mercury-exposed herbarium group, 2.28 microg g(-1) creatinine, was significantly higher than in the control group, 1.05 microg g(-1) of creatinine. For both populations, the concentrations of Hg in their urine were below the threshold Hg values set by the WHO, i.e., 5 microg g(-1) creatinine. We concluded that there was no strong response by individual herbarium staff from long-term exposure to Hg concentrations in the range of 0.28-1.1 microg m(-3).

One-step synthesis of magnetic graphene oxide nanocomposite and its application in magnetic solid phase extraction of heavy metal ions from biological samples.

PubMed

Sun, Jieping; Liang, Qionglin; Han, Qiang; Zhang, Xiaoqiong; Ding, Mingyu

2015-01-01

A novel magnetic graphene oxide nanocomposite was synthesized by one-step coprecipitation method and characterized by transmission electron microscopy, X-ray photoelectron spectroscopy and vibrating sample magnetometer. The nanocomposite beard many intriguing properties, including chemical stability, high adsorption capacity, and superparamagnetic. These properties evoked great interest and desire of its exploration in magnetic solid-phase extraction of heavy metal ions from complex samples. Several parameters effecting the analytical performance, such as the sample pH, amounts of adsorbent, sample volumes, elution volumes, and coexisting ions, had been investigated in detail. The adsorbed metal ions were easy eluted by controlling the pH condition and the materials could be reused more than 20 times. Under the optimized conditions, the limits of detection were 0.016, 0.046, 0.395, 0.038, 0.157 μg L(-1) for Co(2+), Ni(2+), Cu(2+), Cd(2+), and Pb(2+), respectively. The intra-day relative standard deviations (n=5) were in the range of 1.8-5.5% at 10 μg L(-1). The proposed method was successfully applied to biological sample analysis and got excellent recoveries in the range of 81-113% even the matrix was complex. Copyright © 2014 Elsevier B.V. All rights reserved.

Temperature Controller System for Gas Gun Targets

NASA Astrophysics Data System (ADS)

Bucholtz, Scott; Sheffield, Stephen

2005-07-01

A temperature controller system capable of heating and cooling gas gun targets over the range -75 C to +200 C was designed and tested. The system uses cold nitrogen gas from a liquid nitrogen Dewar for cooling and compressed air for heating. Two gas flow heaters control the gas temperature for both heating and cooling. One heater controls the temperature of the target mounting plate and the other the temperature of a copper tubing coil surrounding the target. Each heater is separately adjustable, so the target material will achieve a uniform temperature throughout its volume. A magnetic gauge with integrated thermocouples was developed to measure the internal temperature of the target. Using this system shock experiments, including equation-of-state measurements and shock initiation of high explosives, can be performed over a range of initial temperatures. Successful tests were completed on Teflon samples. This work was supported by the NNSA Enhanced Surveillance Campaign through contract DE-ACO4-01AL66850.

Mental Health Consequences of Intimate Partner Abuse

PubMed Central

Mechanic, Mindy B.; Weaver, Terri L.; Resick, Patricia A.

2010-01-01

Battered women are exposed to multiple forms of intimate partner abuse. This article explores the independent contributions of physical violence, sexual coercion, psychological abuse, and stalking on symptoms of posttraumatic stress disorder (PTSD) and depression among a sample of 413 severely battered, help-seeking women. The authors test the unique effects of psychological abuse and stalking on mental health outcomes, after controlling for physical violence, injuries, and sexual coercion. Mean scores for the sample fall into the moderate to severe range for PTSD and within the moderate category for depression scores. Hierarchical regressions test the unique effects of stalking and psychological abuse, after controlling for physical violence, injuries, and sexual coercion. Psychological abuse and stalking contribute uniquely to the prediction of PTSD and depression symptoms, even after controlling for the effects of physical violence, injuries, and sexual coercion. Results highlight the importance of examining multiple dimensions of intimate partner abuse. PMID:18535306

[Relationship between blood glucose levels and salivary pH and buffering capacity in type II diabetes patients].

PubMed

Elkafri, I H; Mashlah, A; Shaqifa, A

2014-03-13

This study was evaluated the relationship between blood glucose levels and salivary pH and buffering capacity in type II diabetic patients. The sample comprised 210 participants (age ranged 40-60 years). Based on fasting blood glucose levels the participants were divided into 3 groups: controls with normal blood glucose levels; diabetic patients with levels ≤ 200 mg/dL; and diabetic patients with levels > 200 mg/dL. Salivary pH and buffering capacity were determined in a sample of resting (non-stimulated) saliva taken from each participant. Salivary pH levels in diabetic patients with blood glucose levels > 200 mg/dL were lower than in the controls and diabetic patients with levels ≤ 200 mg/dL. Salivary pH levels were comparable in controls and diabetic patients with blood glucose levels ≤ 200 mg/dL. Salivary buffering capacity in the 3 groups was comparable.

Satellite Charge Control with Lithium Ion Source and Electron Emission

DTIC Science & Technology

1990-12-01

for the spacecraft charge control. C. THERMIONIC ELECTRON EMISSION Electrons may be emitted by surfaces at high temperature in a process, called...data in the high voltage region and 1300 to 1600 °K temperature range may be fitted to the following equation, for a 50 % lithium sample: log01 =logos...in Figure 15, is similar to a high - temperature quartz structure, yet differs from it in that half of the silicon atoms are repiaced by aluminum atoms

Determination of naturally occurring formaldehyde levels in sap and wood tissue of maple trees using gas chromatgraphy/mass spectrometry.

PubMed

Lagacé, Luc; Gaudy, Réjean; Perez-Locas, Carolina; Sadiki, Mustapha

2012-01-01

The occurrence of formaldehyde in sap and wood tissue of treated and untreated maple sugar trees was investigated using GC/MS. Samples were collected at different periods of the 2009 season and at different locations in Quebec, Canada. The natural concentration of formaldehyde found in untreated samples varied according to periods and locations and ranged from below the LOQ to 1.82 mg/kg for sap samples and from 2.39 to 8.92 mg/kg of fresh tissue for wood samples. Late season samples tended to have higher concentrations of formaldehyde. Samples of sap and wood tissue from tapholes treated with solutions of formaldehyde showed increased concentrations of formaldehyde for many days after treatment and were clearly distinct from untreated samples. These results will be useful to elaborate new inspection procedures for sugarbushes to control the illegal use of formaldehyde.

Acoustic levitator for structure measurements on low temperature liquid droplets.

PubMed

Weber, J K R; Rey, C A; Neuefeind, J; Benmore, C J

2009-08-01

A single-axis acoustic levitator was constructed and used to levitate liquid and solid drops of 1-3 mm in diameter at temperatures in the range -40 to +40 degrees C. The levitator comprised (i) two acoustic transducers mounted on a rigid vertical support that was bolted to an optical breadboard, (ii) an acoustic power supply that controlled acoustic intensity, relative phase of the drive to the transducers, and could modulate the acoustic forces at frequencies up to 1 kHz, (iii) a video camera, and (iv) a system for providing a stream of controlled temperature gas flow over the sample. The acoustic transducers were operated at their resonant frequency of approximately 22 kHz and could produce sound pressure levels of up to 160 dB. The force applied by the acoustic field could be modulated to excite oscillations in the sample. Sample temperature was controlled using a modified Cryostream Plus and measured using thermocouples and an infrared thermal imager. The levitator was installed at x-ray beamline 11 ID-C at the Advanced Photon Source and used to investigate the structure of supercooled liquids.

Acoustic levitator for structure measurements on low temperature liquid droplets

NASA Astrophysics Data System (ADS)

Weber, J. K. R.; Rey, C. A.; Neuefeind, J.; Benmore, C. J.

2009-08-01

A single-axis acoustic levitator was constructed and used to levitate liquid and solid drops of 1-3 mm in diameter at temperatures in the range -40 to +40 °C. The levitator comprised (i) two acoustic transducers mounted on a rigid vertical support that was bolted to an optical breadboard, (ii) an acoustic power supply that controlled acoustic intensity, relative phase of the drive to the transducers, and could modulate the acoustic forces at frequencies up to 1 kHz, (iii) a video camera, and (iv) a system for providing a stream of controlled temperature gas flow over the sample. The acoustic transducers were operated at their resonant frequency of ˜22 kHz and could produce sound pressure levels of up to 160 dB. The force applied by the acoustic field could be modulated to excite oscillations in the sample. Sample temperature was controlled using a modified Cryostream Plus and measured using thermocouples and an infrared thermal imager. The levitator was installed at x-ray beamline 11 ID-C at the Advanced Photon Source and used to investigate the structure of supercooled liquids.

Challenges in Identifying and Determining the Impacts of Infection with Pestiviruses on the Herd Health of Free Ranging Cervid Populations

PubMed Central

Ridpath, Julia F.; Neill, John D.

2016-01-01

Although most commonly associated with the infection of domestic livestock, the replication of pestiviruses, in particular the two species of bovine viral diarrhea virus (BVDV), occurs in a wide range of free ranging cervids including white-tailed deer, mule deer, fallow deer, elk, red deer, roe deer, eland and mousedeer. While virus isolation and serologic analyses indicate that pestiviruses are circulating in these populations, little is known regarding their impact. The lack of regular surveillance programs, challenges in sampling wild populations, and scarcity of tests and vaccines compound the difficulties in detecting and controlling pestivirus infections in wild cervids. Improved detection rests upon the development and validation of tests specific for use with cervid samples and development and validation of tests that reliably detect emerging pestiviruses. Estimation of impact of pestivirus infections on herd health will require the integration of several disciplines including epidemiology, cervid natural history, veterinary medicine, pathology and microbiology. PMID:27379051

Small passive student experiments on G324 261 individual quests for student knowledge

NASA Technical Reports Server (NTRS)

Nicholson, James H.; Tempel, Carol A.; Ashcraft, Ruth; Rutherford, Robin

1995-01-01

The Charleston County School District CAN DO Project payload on STS-57 had a primary goal of photographing the Earth with the GeoCam camera system. In addition, the payload carried 261 passive student experiments representing the efforts of several thousand students throughout the district and in four other states. These experiments represented the individual concepts of teams ranging in age from pre-school to high school. Consequently, a tremendous variety of samples from collard green seeds to microscopic 'water bears' were flown. Each prospective team was provided a simple kit equipped with five vials. Each student team submitted five coded samples, one for space flight and four control samples. The control samples were exposed to radiation, cold and centrifugation respectively while one negative control sample was passively stored. The students received the samples back still coded so that they were unaware of which samples were flown. They then investigated their samples according to their individual research protocols. The results were presented in poster and platform form at a student research symposium. Space Trees grown from tree seeds flown in the payload have been planted at all district schools, and at many guest schools. These seeds represented another way in which to involve additional classes and students. Both the passive experiments and the space trees were housed in what otherwise would have been wasted space within the payload. They extended the GAS programs worthwhile ballast concept to another level. The opportunity to fly an experiment in space is too previous not to be extended to the greatest number of students possible.

Natural postharvest aflatoxin occurrence in food legumes in the smallholder farming sector of Zimbabwe.

PubMed

Maringe, David Tinayeshe; Chidewe, Cathrine; Benhura, Mudadi Albert; Mvumi, Brighton Marimanzi; Murashiki, Tatenda Clive; Dembedza, Mavis Precious; Siziba, Lucia; Nyanga, Loveness Kuziwa

2017-03-01

Aflatoxins, mainly produced by Aspergillus flavus and Aspergillus parasiticus, are highly toxic and may lead to health problems such as liver cancer. Exposure to aflatoxins may result from ingestion of contaminated foods. Levels of AFB 1 , AFB 2 , AFG 1 and AFG 2 in samples of groundnuts (Arachis hypogaea), beans (Phaseolus vulgaris), cowpeas (Vigna unguiculata) and bambara nuts (Vigna subterranean) grown by smallholder farmers in Shamva and Makoni districts, Zimbabwe, were determined at harvesting, using high performance liquid chromatography after immunoaffinity clean-up. Aflatoxins were detected in 12.5% of groundnut samples with concentrations ranging up to 175.9 µg/kg. Aflatoxins were present in 4.3% of the cowpea samples with concentrations ranging from 1.4 to 103.4 µg/kg. Due to alarming levels of aflatoxins detected in legumes versus maximum permissible levels, there is a need to assist smallholder farmers to develop harvest control strategies to reduce contamination of aflatoxins in legumes.

Occurrence of Hydrocarbon Degrading Genes in the Soils of the Republic of Tatarstan (Russia)

NASA Astrophysics Data System (ADS)

Biktasheva, L. R.; Shalyamova, R. P.; Guseva, U. A.; Galitskaya, P. Yu

2018-01-01

Oil pollution is one of the most serious environmental problems nowadays. The ability of soils for self-restoration is important, when choosing the strategy of pollution control. This ability depends on the pull of microbes able to decompose hydrocarbons that were present in the nonpolluted soil prior to pollution. In this study, the occurrence of alkane degrading genes in the soils of the Republic of Tatarstan being one of the oil processing regions in Russia, was investigated. It was found that alkane degrading genes belonging to group I were present in 20 of the 25 soil samples, and their abundances ranged between 0.01 and 0.07%. Alkane degrading genes belonging to group II were not detected in the samples investigated, and those belonging to group III were present in all the samples, and their abundances ranged between 0.06 and 7.25%. No correlation between the alkane degrading gene copy numbers and pH and organic carbon content in soils was revealed.

Stormwater-runoff data, Madison, Wisconsin, 1993-94

USGS Publications Warehouse

Waschbusch, R.J.

1996-01-01

As required by Section 402(P) of the Water Quality Control Act of 1987, stormwater-runoff samples collected during storms that met three criteria (rainfall depths 50 to 150 percent of average depth range, rainfall durations 50 to 150 percent of average duration, and antecedent dry-weather period of at least 72 hours) were analyzed for semivolatile organic chemicals, total metals, pesticides, polychlorinated biphenyls, inorganic constituents, bacteria, oil and grease, pH, and water temperature. Two of the seven sites also had samples analyzed for volatile organic chemicals. In addition to the required sampling, additional runoff samples that did not necessarily meet the three rainfall criteria, were analyzed for total metals and inorganic constituents. Storm loads of selected constituents were computed.

Evaluation of quality-control data collected by the U.S. Geological Survey for routine water-quality activities at the Idaho National Laboratory, Idaho, 1996–2001

USGS Publications Warehouse

Rattray, Gordon W.

2012-01-01

The U.S. Geological Survey, in cooperation with the U.S. Department of Energy, collects surface water and groundwater samples at and near the Idaho National Laboratory as part of a routine, site-wide, water-quality monitoring program. Quality-control samples are collected as part of the program to ensure and document the quality of environmental data. From 1996 to 2001, quality-control samples consisting of 204 replicates and 27 blanks were collected at sampling sites. Paired measurements from replicates were used to calculate variability (as reproducibility and reliability) from sample collection and analysis of radiochemical, chemical, and organic constituents. Measurements from field and equipment blanks were used to estimate the potential contamination bias of constituents. The reproducibility of measurements of constituents was calculated from paired measurements as the normalized absolute difference (NAD) or the relative standard deviation (RSD). The NADs and RSDs, as well as paired measurements with censored or estimated concentrations for which NADs and RSDs were not calculated, were compared to specified criteria to determine if the paired measurements had acceptable reproducibility. If the percentage of paired measurements with acceptable reproducibility for a constituent was greater than or equal to 90 percent, then the reproducibility for that constituent was considered acceptable. The percentage of paired measurements with acceptable reproducibility was greater than or equal to 90 percent for all constituents except orthophosphate (89 percent), zinc (80 percent), hexavalent chromium (53 percent), and total organic carbon (TOC; 38 percent). The low reproducibility for orthophosphate and zinc was attributed to calculation of RSDs for replicates with low concentrations of these constituents. The low reproducibility for hexavalent chromium and TOC was attributed to the inability to preserve hexavalent chromium in water samples and high variability with the analytical method for TOC. The reliability of measurements of constituents was estimated from pooled RSDs that were calculated for discrete concentration ranges for each constituent. Pooled RSDs of 15 to 33 percent were calculated for low concentrations of gross-beta radioactivity, strontium-90, ammonia, nitrite, orthophosphate, nickel, selenium, zinc, tetrachloroethene, and toluene. Lower pooled RSDs of 0 to 12 percent were calculated for all other concentration ranges of these constituents, and for all other constituents, except for one concentration range for gross-beta radioactivity, chloride, and nitrate + nitrite; two concentration ranges for hexavalent chromium; and TOC. Pooled RSDs for the 50 to 60 picocuries per liter concentration range of gross-beta radioactivity (reported as cesium-137) and the 10 to 60 milligrams per liter (mg/L) concentration range of nitrate + nitrite (reported as nitrogen [N]) were 17 percent. Chloride had a pooled RSD of 14 percent for the 20 to less than 60 mg/L concentration range. High pooled RSDs of 40 and 51 percent were calculated for two concentration ranges for hexavalent chromium and of 60 percent for TOC. Measurements from (1) field blanks were used to estimate the potential bias associated with environmental samples from sample collection and analysis, (2) equipment blanks were used to estimate the potential bias from cross contamination of samples collected from wells where portable sampling equipment was used, and (3) a source-solution blank was used to verify that the deionized water source-solution was free of the constituents of interest. If more than one measurement was available, the bias was estimated using order statistics and the binomial probability distribution. The source-solution blank had a detectable concentration of hexavalent chromium of 2 micrograms per liter. If this bias was from a source other than the source solution, then about 84 percent of the 117 hexavalent chromium measurements from environmental samples could have a bias of 10 percent or more. Of the 14 field blanks that were collected, only chloride (0.2 milligrams per liter) and ammonia (0.03 milligrams per liter as nitrogen), in one blank each, had detectable concentrations. With an estimated confidencelevel of 95 percent, at least 80 percent of the 1,987 chloride concentrations measured from all environmental samples had a potential bias of less than 8 percent. The ammonia bias, which may have occurred at the analytical laboratory, could produce a potential bias of 5-100 percent in eight potentially affected ammonia measurements. Of the 11 equipment blanks that were collected, chloride was detected in 4 of these blanks, sodium in 3 blanks, and sulfate and hexavalent chromium were each detected in 1 blank. The concentration of hexavalent chromium in the equipment blank was the same concentration as in the source-solution blank collected on the same day, which indicates that the hexavalent chromium in the equipment blank is probably from a source other than the portable sampling equipment, such as the sample bottles or the source-solution water itself. The potential bias for chloride, sodium, and sulfate measurements was estimated for environmental samples that were collected using portable sampling equipment. For chloride, it was estimated with 93 percent confidence that at least 80 percent of the measurements had a bias of less than 18 percent. For sodium and sulfate, it was estimated with 91 percent confidence that at least 70 percent of the measurements had a bias of less than 12 and 5 percent, respectively.

Diagnostic Accuracy, Sensitivity, and Specificity of Executive Function Tests in Moderate Traumatic Brain Injury in Ghana.

PubMed

Adjorlolo, Samuel

2018-06-01

The sociocultural differences between Western and sub-Saharan African countries make it imperative to standardize neuropsychological tests in the latter. However, Western-normed tests are frequently administered in sub-Saharan Africa because of challenges hampering standardization efforts. Yet a salient topical issue in the cross-cultural neuropsychology literature relates to the utility of Western-normed neuropsychological tests in minority groups, non-Caucasians, and by extension Ghanaians. Consequently, this study investigates the diagnostic accuracy, sensitivity, and specificity of executive function (EF) tests (The Stroop Test, Trail Making Test, and Controlled Oral Word Association Test), and a Revised Quick Cognitive Screening Test (RQCST) in a sample of 50 patients diagnosed with moderate traumatic brain injury and 50 healthy controls in Ghana. The EF test scores showed good diagnostic accuracy, with area under the curve (AUC) values of the Trail Making Test scores ranging from .746 to .902. With respect to the Stroop Test scores, the AUC values ranged from .793 to .898, while Controlled Oral Word Association Test had AUC value of .787. The RQCST scores discriminated between the groups, with AUC values ranging from .674 to .912. The AUC values of composite EF score and a neuropsychological score created from EF and RQCST scores were .936 and. 942, respectively. Additionally, the Stroop Test, Trail Making Test, EF composite score, and RQCST scores showed good to excellent sensitivities and specificities. In general, this study has shown that commonly used EF tests in Western countries have diagnostic accuracy, sensitivity, and specificity when administered in Ghanaian samples. The findings and implications of the study are discussed.

Anatomy of the thriple oxygen isotope Terrestrial Fractionatoin Line

NASA Astrophysics Data System (ADS)

Sharp, Z. D.; Pack, A.

2017-12-01

In the triple oxygen isotope system, it is well established that the δ17O value of nearly all terrestrial materials is approximately ½ that of the corresponding δ18O value. In triple isotope space then, all samples plot on a slope 1/2 line, termed the Terrestrial Fractionation Line (TFL). It has recently been recognized that subtle, but significant departures from the TFL exist, given by Δ'17O = δ'17O -λ× δ'18O + γ, where λ is the slope of the TFL (γ is the y-intercept and assumed to be zero in most studies). There have been many published λ values, ranging from 0.52 to 0.5305. λ values determined from a best-fit to rock and mineral samples range from 0.5244 to 0.5266. λ values from meteoric waters are 0.527 to 0.528 (γ = 0.007 to 0.034), explained by equilibrium and kinetic processes. Extreme polar glacial samples define a λ >0.53. As pointed out by Matsuhisia et al. (GCA, 1978), there is no single factor that controls the δ17O-δ18O slope, and clearly there is no `correct' TFL line. However, some generalities can be noted. 1) Meteoric waters generally plot with a λ = 0.528 with a Δ'17O = 0.033. At both high and low δ18O values, the Δ'17O values of meteoritic waters decrease. Mantle derived samples plot in a limited δ space, with δ18O values of 5-9‰ and a Δ'17O of -0.05‰. Rock and mineral samples falling outside this narrow range have undergone interaction with meteoric or ocean water at some point in their history, either by alteration or neoform mineral growth. The quartz-water triple isotope fractionation factor varies with temperatures, ranging from 0.5237 to 0.5266 at 0°C and 200°C, respective. A fit to published rock data gives an overall λ = 0.5237-0.5240. These results are most likely explained by the sum of hydrothermal and low-temperature mineral-water fractionations. Attempting to place any significance on a TFL from a set of data in unwarranted without understanding the processes controlling the isotopic compositions of the phases.

Physico-chemical properties and performance of high oleic and palm-based shortenings.

PubMed

Ramli, Muhamad Roddy; Lin, Siew Wai; Yoo, Cheah Kien; Idris, Nor Aini; Sahri, Miskandar Mat

2008-01-01

Solid fat from fractionation of palm-based products was converted into cake shortening at different processing conditions. High oleic palm stearin with an oleic content of 48.2 % was obtained from fractionation of high oleic palm oil which was produced locally. Palm product was blended with different soft oils at pre-determined ratio and further fractionated to obtain the solid fractions. These fractions were then converted into cake shortenings named as high oleic, N1 and N2 blends. The physico-chemical properties of the experimental shortenings were compared with those of control shortenings in terms of fatty acid composition (FAC), iodine value (IV), slip melting point (SMP), solid fat content (SFC) and polymorphic forms. Unlike the imported commercial shortenings as reported by other studies and the control, experimental shortenings were trans-free. The SMP and SFC of experimental samples, except for the N2 sample, fell within the ranges of commercial and control shortenings. The IV was higher than those of domestic shortenings but lower when compared to imported and control shortenings. They were also observed to be beta tending even though a mixture of beta and beta' was observed in the samples after 3 months of storage. The shortenings were also used in the making of pound cake and sensory evaluation showed the good performance of high oleic sample as compared to the other shortenings.

Comparison of essential and toxic elements in esophagus, lung, mouth and urinary bladder male cancer patients with related to controls.

PubMed

Kazi, Tasneem Gul; Wadhwa, Sham Kumar; Afridi, Hassan Imran; Talpur, Farah Naz; Tuzen, Mustafa; Baig, Jameel Ahmed

2015-05-01

There is a compelling evidence in support of negative associations between essential trace and toxic elements in different types of cancer. The aim of the present study was to investigate the relationship between carcinogenic (As, Cd, Ni) and anti-carcinogenic (Se, Zn) trace elements in scalp hair samples of different male cancerous patients (esophagus, lung, mouth, and urinary bladder). For comparative purposes, the scalp hair samples of healthy males of the same age group (ranged 35-65 years) as controls were analyzed. Both controls and patients have the same socioeconomic status, localities, dietary habits, and smoking locally made cigarette. The scalp hair samples were oxidized by 65% nitric acid: 30% hydrogen peroxide (2:1) ratio in microwave oven followed by atomic absorption spectrometry. The validity and accuracy of the methodology were checked using certified reference material of human hair BCR 397. The mean concentrations of As, Cd, and Ni were found to be significantly higher in scalp hair samples of patients having different cancers as compared to the controls, while reverse results were obtained in the case of Se and Zn levels (p < 0.01). The study revealed that the carcinogenic processes are significantly affecting the trace elements burden and mutual interaction of essential trace and toxic elements in the cancerous patients.

Distribution of copper, iron, and zinc in biological samples (scalp hair, serum, blood, and urine) of Pakistani viral hepatitis (A-E) patients and controls.

PubMed

Kolachi, Nida Fatima; Kazi, Tasneem Gul; Afridi, Hassan Imran; Kazi, Naveed; Kandhro, Ghulam Abbas; Shah, Abdul Qadir; Baig, Jameel Ahmed; Wadhwa, Sham Kumar; Khan, Sumaira; Shah, Faheem; Jamali, Mohammad Khan; Arain, Mohammad Balal

2011-10-01

The aim of the present study was to compare the level of copper (Cu), iron (Fe) and zinc (Zn) in biological samples (serum, blood, urine, and scalp hair) of patients suffering from different viral hepatitis (A, B, C, D, and E; n = 521) of both gender age ranged 31-45 years. For comparative study, 255 age-matched control subjects, of both genders residing in the same city were selected as referents. The elements in the biological samples were analyzed by flame atomic absorption spectrophotometry, prior to microwave-assisted acid digestion. The validity and accuracy of the methodology was checked by using certified reference materials (CRMs) and with those values obtained by conventional wet acid digestion method on same CRMs. The results of this study showed that the mean values of Cu and Fe were higher in blood, sera, and scalp hair samples of hepatitis patients, while Zn level was found to be lower than age-matched control subjects. The urinary levels of these elements were found to be higher in the hepatitis patients than in the age-matched healthy controls (p < 0.05). These results are consistent with literature-reported data, confirming that the deficiency of zinc and hepatic iron and copper overload can directly cause lipid peroxidation and eventually hepatic damage.

Erythrocyte oxidative stress markers in children with sickle cell disease.

PubMed

Hermann, Priscila Bacarin; Pianovski, Mara Albonei Dudeque; Henneberg, Railson; Nascimento, Aguinaldo José; Leonart, Maria Suely Soares

2016-01-01

To determine eight parameters of oxidative stress markers in erythrocytes from children with sickle cell disease and compare with the same parameters in erythrocytes from healthy children, since oxidative stress plays an important role in the pathophysiology of sickle cell disease and because this disease is a serious public health problem in many countries. Blood samples were obtained from 45 children with sickle cell disease (21 males and 24 females with a mean age of 9 years; range: 3-13 years) and 280 blood samples were obtained from children without hemoglobinopathies (137 males and 143 females with a mean age of 10 years; range: 8-11 years), as a control group. All blood samples were analyzed for methemoglobin, reduced glutathione, thiobarbituric acid reactive substances, percentage of hemolysis, reactive oxygen species, and activity of the enzymes glucose 6-phosphate dehydrogenase, superoxide dismutase, and catalase. Data were analyzed using Student's t-test and were expressed as the mean±standard deviation. A p-value of <0.05 was considered significant. Significant differences were observed between children with sickle cell disease and the control group for the parameters methemoglobin, thiobarbituric acid reactive substances, hemolysis, glucose 6-phosphate dehydrogenase activity, and reactive oxygen species, with higher levels in the patients than in the controls. Oxidative stress parameters in children's erythrocytes were determined using simple laboratory methods with small volumes of blood; these biomarkers can be useful to evaluate disease progression and outcomes in patients. Copyright © 2016 Sociedade Brasileira de Pediatria. Published by Elsevier Editora Ltda. All rights reserved.

Doping control analysis of 121 prohibited substances in equine hair by liquid chromatography-tandem mass spectrometry.

PubMed

Wong, J K Y; Choi, T L S; Kwok, K Y; Lei, E N Y; Wan, T S M

2018-06-01

Equine hair is becoming an increasingly popular biological matrix for doping control of horse sports; one of the reasons for this is the significantly longer detection window hair can offer. Hair analysis opens up the opportunity for longitudinal monitoring of drug exposure which would otherwise not be possible with the more traditional and common biological matrices, such as urine and blood. As such, there is a need for more multi-target screening methods covering a broad range of prohibited substances in equine hair at the required sensitivities for equine doping control. This paper describes a sensitive ultra-high performance liquid chromatography - tandem mass spectrometry (UHPLC-MS/MS) method for the detection of 121 drugs and/or their metabolites in equine hair covering ten classes of prohibited substances with estimated limits of detection between 0.1 and 10 pg/mg. To our knowledge, this is the first report of a screening method in equine hair which can cover such a broad range and well over one hundred prohibited substances in a single analytical run. This method has been validated for its specificity, precision and extraction recovery. Applicability of this method has been demonstrated by: (i) the successful identification of clenbuterol, 2-(1-hydroxyethyl) promazine sulfoxide, acepromazine and tetrahydrozoline in genuine equine mane samples; as well as (ii) the detection of drugs from artificially incurred mane hair samples which have been prepared by soaking blank hair samples in solutions of drug targets. Copyright © 2018 Elsevier B.V. All rights reserved.

Urinary β2 microglobulin in workers exposed to arc welding fumes.

PubMed

Aminian, Omid; Eftekhari, Saeid; Mazaheri, Maria; Sharifian, Seyed Akbar; Sadeghniiat-Haghighi, Khosro

2011-01-01

Welding is a process in which two or more metals are attached by the use of heat and, in some cases, pressure. Direct exposure and inhalation of welding fumes causes acute and chronic side effects in humans. Kidney damage is one of these important side effects. β(2) microglobulin is an 11.8 kilodalton protein and levels increase in the case of some inflammatory and viral diseases, or kidney malfunction and autoimmune diseases. In this study measurements of β(2) microglobulin were used as a criterion for assessing effects on the kidneys of workers exposed to welding fumes. The study population were electric arc welders in an industrial plant in Tehran, Iran. For control we selected workers who did not have any exposure to welding fumes. Both groups were selected on the basis of a questionnaire and the consideration of criteria for inclusion and exclusion. In the end 50 cases and 50 controls were chosen. A urine sample was collected from all participants and urinary pH was set to between 6-8 using NaOH (1M). Sample transportation to the laboratory complied with the related standards. The samples were assessed using the ORG 5BM kit. For quantitative assessment of β(2) microglobulin we used the Enzyme-linked Immunosorbent Assay (ELISA) method. The ages of the welders ranged from 21 to 48 years (mean=30.5 ± 5.9 yrs) and of controls from 23 to 56 years (mean=31.8 ± 5.9 yrs). Mean employment duration was 7.86 ± 5.01 years (range 2 to 27 years) for welders. Mean β(2) microglobulin level was 0.10 ± 0.096 μg/ml in welders and 0.11 ± 0.06 in controls. This difference was not statistically significant (P=0.381). In conclusion we don't find that exposure to electric arc welding fumes cause a significant change in urinary β(2) microglobulin compared to the control group.

Copper and cadmium in bottom sediments dredged from Wyścigi Pond, Warsaw, Poland--contamination and bioaccumulation study.

PubMed

Wojtkowska, Małgorzata; Karwowska, Ewa; Chmielewska, Iwona; Bekenova, Kundyz; Wanot, Ewa

2015-12-01

This research covered an evaluation of the copper and cadmium concentrations in bottom sediments dredged from one of the ponds in Warsaw. The samples of sediments, soil, and plants were analyzed in terms of Cu and Cd content. The research concerned the heap of dredged bottom sediments from Wyścigi Pond, Warsaw, Poland. Two boreholes were made to obtain sediment cores with depths of A 162.5 cm and B 190.0 cm. The cores were divided into 10 sub-samples with a thickness of about 15-20 cm. A control sample of soil was taken from the horse racecourse several hundred meters away from the heap. The vegetation was sampled directly from the heap. The predominating plants were tested: Urtica dioica, Glechoma hederacea, Euonymus verrucosus, and Drepanocladus aduncus. A control sample of U. dioica taken outside of the heap was also tested. The commercial PHYTOTOXKIT microbiotest was applied to evaluate the influence of heavy metal-contaminated sediments (used as soil) on germination and growth of the chosen test plants. The analyses of cadmium and copper concentrations revealed that the metal concentration in sediments was diverse at different depths of sampling, probably reflecting their concentration in stored layers of sediments. Moreover, the metal content in core A was four to five times lower than that in core B, which reveals heterogeneity of the sediments in the tested heap. In core A, the copper concentration ranged from 4.7 to 13.4 mg/kg d.w. (average 8.06 ± 0.71 mg/kg d.w.), while in core B, it ranged from 9.2 to 82.1 mg/kg d.w. (average 38.56 ± 2.6 mg/kg d.w.). One of the results of the heavy metal presence in soils is their bioaccumulation in plants. Comparing plant growth, more intensive growth of roots was observed in the case of plants growing on the control (reference) soil than those growing on sediments. The intensive development of both primary and lateral roots was noticed. During this early growth, metal accumulation in plants occurred.

Gemas: issues from the comparison of aqua regia and X-ray fluorescence results

NASA Astrophysics Data System (ADS)

Dinelli, Enrico; Birke, Manfred; Reimann, Clemens; Demetriades, Alecos; DeVivo, Benedetto; Flight, Dee; Ladenberger, Anna; Albanese, Stefano; Cicchella, Domenico; Lima, Annamaria

2014-05-01

The comparison of analytical results from aqua regia (AR) and X-ray fluorescence spectroscopy (XRF) can provide information on soil processes controlling the element distribution. The GEMAS (GEochemical Mapping of Agricultural and grazing land Soils) agricultural soil database is used for this comparison. Analyses for the same suite of elements and parameters were carried out in the same laboratory under strict quality control procedures. Sample preparation has been conducted at the laboratory of the The comparison of analytical results from aqua regia (AR) and X-ray fluorescence spectroscopy (XRF) can provide information on soil processes controlling the element distribution in soil. The GEMAS (GEochemical Mapping of Agricultural and grazing land Soils) agricultural soil database, consisting of 2 x ca. 2100 samples spread evenly over 33 European countries, is used for this comparison. Analyses for the same suite of elements and parameters were carried out in the same laboratory under strict quality control procedures. Sample preparation has been conducted at the laboratory of the Geological Survey of the Slovak Republic, AR analyses were carried out at ACME Labs, and XRF analyses at the Federal Institute for Geosciences and Natural Resources, Germany Element recovery by AR is very different, ranging from <1% (e.g. Na, Zr) to > 80% (e.g. Mn, P, Co). Recovery is controlled by mineralogy of the parent material, but geographic and climatic factors and the weathering history of the soils are also important. Nonetheless, even the very low recovery elements show wide ranges of variation and spatial patterns that are affected by other factors than soil parent material. For many elements soil pH have a clear influence on AR extractability: under acidic soil conditions almost all elements tend to be leached and their extractability is generally low. It progressively increases with increasing pH and is highest in the pH range 7-8. Critical is the clay content of the soil that almost for all elements correspond to higher extractability with increasing clay abundance. Also other factors such as organic matter content of soil, Fe and Mn occurrence are important for certain elements or in selected areas. This work illustrates that there are significant differences in the extractability of elements from soils and addresses important influencing factors related to soil properties, geology, climate.

Portable Device Analyzes Rocks and Minerals

NASA Technical Reports Server (NTRS)

2008-01-01

inXitu Inc., of Mountain View, California, entered into a Phase II SBIR contract with Ames Research Center to develop technologies for the next generation of scientific instruments for materials analysis. The work resulted in a sample handling system that could find a wide range of applications in research and industrial laboratories as a means to load powdered samples for analysis or process control. Potential industries include chemical, cement, inks, pharmaceutical, ceramics, and forensics. Additional applications include characterizing materials that cannot be ground to a fine size, such as explosives and research pharmaceuticals.

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

Marshall, R.S.

A simple in-line americium assay instrument (AAI) was installed at an americium recovery process area at LASL for use in process development and for providing process control information. The AAI counts 59.5-keV /sup 241/Am gamma rays, using a NaI(T1) detector and Eberline SAM II electronics. It has a useful range of 3 x 10/sup -5/ to 10 g Am/l and does not suffer from plutonium interference. Comparative analyses of samples assayed in the AAI and samples assayed by the LASL Analytical Laboratory show a combined relative standard deviation of 14%.

Digital Baseband Architecture For Transponder

NASA Technical Reports Server (NTRS)

Nguyen, Tien M.; Yeh, Hen-Geul

1995-01-01

Proposed advanced transponder for long-distance radio communication system with turnaround ranging contains carrier-signal-tracking loop including baseband digital "front end." For reduced cost, transponder includes analog intermediate-frequency (IF) section and analog automatic gain control (AGC) loop at first of two IF mixers. However, second IF mixer redesigned to ease digitization of baseband functions. To conserve power and provide for simpler and smaller transponder hardware, baseband digital signal-processing circuits designed to implement undersampling scheme. Furthermore, sampling scheme and sampling frequency chosen so redesign involves minimum modification of command-detector unit (CDU).

Lipid peroxidative damage in the erythrocytes and elevation of serum LDL-cholesterol, apolipoprotein-B, ferritin and uric acid with age and in coronary heart disease patients.

PubMed

El-Gebali, H H; Tahir, S A; Haider, S S; El-Fakhri, M M

2000-02-01

To determine the normal serum levels of LDL-cholesterol, apolipoprotein-B, ferritin, uric acid, and the extent of erythrocytes lipid peroxidation in healthy control group subjects and to compare them with coronary heart disease patients. Secondly, to study the effects of age and sex on these parameters. The blood samples from 150 healthy Libyan control group subjects (110 men and 40 women) were classified into 3 groups according to their age. Group I consisted of 76 subjects with an age range from 20 to 35 years. Group II consisted of 45 subjects with an age range from 36 to 50 years. Group III consisted of 29 subjects with an age range from 51 to 74 years. The blood samples from these groups were analyzed for LDL-cholesterol, apolipoprotein-B, ferritin and uric acid levels. Lipid peroxidation was compared in the erythrocytes of 56 selected healthy control group subjects (31 men and 11 women) of the aforementioned age groups. These parameters have shown age-dependent elevation in their levels. Meanwhile, LDL-cholesterol and Apolipoprotein-B levels in female subjects were higher than those of males. However, lipid peroxidation in the erythrocytes has revealed a statistically significant increase with increasing age. The comparison between 93 selected, sex and age matched, healthy control group subjects with 87 selected coronary heart disease patients (55 men and 45 women) with an age range from 30 to 74 years (49.6+13.25) has demonstrated significantly higher concentration of LDL-cholesterol, Apolipoprotein-B, ferritin and uric acid in coronary heart disease patients than those of healthy control group subjects. Meanwhile, lipid peroxidation was also significantly enhanced in coronary heart disease patients compared with healthy control group subjects. Our study has revealed that an increase in the lipid peroxidation in erythrocytes with age and during coronary heart disease, makes red cell membranes more vulnerable to free radical damage via formation of reactive oxygen species. It is thus likely that peroxidative damage may be contributing to an increase in serum LDL-cholesterol, Apolipoprotein-B, probably after its oxidative modification, increase in ferritin and hyperuricemia in coronary heart disease patients.

Gadolinium Distribution in Cerebrospinal Fluid after Administration of a Gadolinium-based MR Contrast Agent in Humans.

PubMed

Berger, Florian; Kubik-Huch, Rahel A; Niemann, Tilo; Schmid, Hans Ruedi; Poetzsch, Michael; Froehlich, Johannes M; Beer, Jürg H; Thali, Michael J; Kraemer, Thomas

2018-05-08

Purpose To evaluate whether gadolinium penetrates human cerebrospinal fluid (CSF) after MR imaging (MRI) with a gadolinium-based contrast agent (GBCA). Materials and Methods For this retrospective study, the authors analyzed 60 CSF samples from 57 patients (median age, 50 years; range, 3-92 years) who underwent one contrast material-enhanced MRI examination with gadoterate meglumine within 60 days of CSF extraction between January and December 2016. CSF samples from patients who underwent MRI without contrast material administration (n = 22) or those who underwent contrast-enhanced MRI at least 1 year before extraction (n = 2) were analyzed and used as control samples. CSF measurements were performed with inductively coupled plasma mass spectrometry by monitoring the gadolinium 158 isotope. Statistical analyses were performed by using a preliminary Kruskal-Wallis test. Results Higher CSF gadolinium concentrations were detected within the first 8 hours after GBCA administration (mean concentration, 1152 ng/mL ± 734.6). Concentrations were lower between 8 and 48 hours (872 ng/mL ± 586). After 48 hours, gadolinium was almost completely cleared from CSF (121 ng/mL ± 296.3). All but two samples from the 24 control patients (median age, 60.5 years; range, 19-79 years) were negative for the presence of gadolinium. Those samples were from patients who had undergone GBCA-enhanced MRI examination more than a year before CSF extraction (0.1 and 0.2 ng/mL after 1 and 3 years, respectively). The concentrations in patients with chronic renal insufficiency (n = 3), cerebral toxoplasmosis (n = 1), and liver cirrhosis (n = 1) were higher than the mean concentrations. Conclusion Gadoterate meglumine can be detected in human CSF after intravenous administration. © RSNA, 2018.

The relationship between personality and attainment in 16-19-year-old students in a sixth form college: II: Self-perception, gender and attainment.

PubMed

Summerfield, M; Youngman, M

1999-06-01

A related paper (Summerfield & Youngman, 1999) has described the development of a scale, the Student Self-Perception Scale (SSPS) designed to explore the relationship between academic self-concept, attainment and personality in sixth form college students. The study aimed to identify groups of students exhibiting varying patterns of relationship using a range of measures including the SSPS. Issues of gender and also examined. The samples comprised a pilot sample of 152 students (aged 16-17 years from two sixth form colleges) and a main sample of 364 students (mean age, 16 yrs 10 mths range 16:0 to 18:6 years, from one sixth form college). The main sample included similar numbers of male and female students (46% male, 54% female) and ethnic minority students comprised 14% of this sample. Data comprised responses to two personality measures (the SSPS, Summerfield, 1995, and the Nowicki-Strickland Locus of Control Scale, Nowicki & Strickland, 1973), various student and tutor estimates of success, and performance data from college records. Students were classified using relocation cluster analysis and cluster differences verified using discriminant function analysis. Thirty outcome models were tested using covariance regression analysis. Eight distinct and interpretable groups, consistent with other research, were identified but the hypothesis of a positive, linear relationship between mastery and academic attainment was not sustained without qualification. Previous attainment was the major determinant of final performance. Gender variations were detected on the personality measures, particularly Confidence of outcomes, Prediction discrepancy, Passivity, Mastery, Dependency and Locus of control, and these were implicated in the cluster characteristics. The results suggest that a non-linear methodology may be required to isolate relationships between self-concept, personality and attainment, especially where gender effects may exist.

Assessment of heavy metal pollution in Republic of Macedonia using a plant assay.

PubMed

Gjorgieva, Darinka; Kadifkova-Panovska, Tatjana; Bačeva, Katerina; Stafilov, Trajče

2011-02-01

Different plant organs (leaves, flowers, stems, or roots) from four plant species-Urtica dioica L. (Urticaceae), Robinia pseudoacacia L. (Fabaceae), Taraxacum officinale (Asteraceae), and Matricaria recutita (Asteraceae)-were evaluated as possible bioindicators of heavy-metal pollution in Republic of Macedonia. Concentrations of Pb, Cu, Cd, Mn, Ni, and Zn were determined in unwashed plant parts collected from areas with different degrees of metal pollution by ICP-AES. All these elements were found to be at high levels in samples collected from an industrial area. Maximum Pb concentration was 174.52 ± 1.04 mg kg⁻¹ in R. pseudoacacia flowers sampled from the Veles area, where lead and zinc metallurgical activities were present. In all control samples, the Cd concentrations were found to be under the limit of detection (LOD <0.1 mg kg⁻¹) except for R. pseudoacacia flowers and T. officinale roots. The maximum Cd concentration was 7.97 ± 0.15 mg kg⁻¹ in R. pseudoacacia flowers from the Veles area. Nickel concentrations were in the range from 1.90 ± 0.04 to 5.74 ± 0.03 mg kg⁻¹. For U. dioica leaves and R. pseudoacacia flowers sampled near a lead-smelting plant, concentrations of 465.0 ± 0.55 and 403.56 ± 0.34 mg kg⁻¹ Zn were detected, respectively. In all control samples, results for Zn were low, ranging from 10.2 ± 0.05 to 38.70 ± 0.18 mg kg⁻¹. In this study, it was found that the flower of R. pseudoacacia was a better bioindicator of heavy-metal pollution than other plant parts. Summarizing the results, it can be concluded that T. officinale, U. dioica, and R. pseudoacacia were better metal accumulators and M. recutita was a metal avoider.

High density, multi-range analog output Versa Module Europa board for control system applications

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

Singh, Kundan, E-mail: kundan@iuac.res.in; Das, Ajit Lal

2014-01-15

A new VMEDAC64, 12-bit 64 channel digital-to-analog converter, a Versa Module Europa (VME) module, features 64 analog voltage outputs with user selectable multiple ranges, has been developed for control system applications at Inter University Accelerator Centre. The FPGA (Field Programmable Gate Array) is the module's core, i.e., it implements the DAC control logic and complexity of VMEbus slave interface logic. The VMEbus slave interface and DAC control logic are completely designed and implemented on a single FPGA chip to achieve high density of 64 channels in a single width VME module and will reduce the module count in the controlmore » system applications, and hence will reduce the power consumption and cost of overall system. One of our early design goals was to develop the VME interface such that it can be easily integrated with the peripheral devices and satisfy the timing specifications of VME standard. The modular design of this module reduces the amount of time required to develop other custom modules for control system. The VME slave interface is written as a single component inside FPGA which will be used as a basic building block for any VMEbus interface project. The module offers multiple output voltage ranges depending upon the requirement. The output voltage range can be reduced or expanded by writing range selection bits in the control register. The module has programmable refresh rate and by default hold capacitors in the sample and hold circuit for each channel are charged periodically every 7.040 ms (i.e., update frequency 284 Hz). Each channel has software controlled output switch which disconnects analog output from the field. The modularity in the firmware design on FPGA makes the debugging very easy. On-board DC/DC converters are incorporated for isolated power supply for the analog section of the board.« less

Sampling Participants’ Experience in Laboratory Experiments: Complementary Challenges for More Complete Data Collection

PubMed Central

McAuliffe, Alan; McGann, Marek

2016-01-01

Speelman and McGann’s (2013) examination of the uncritical way in which the mean is often used in psychological research raises questions both about the average’s reliability and its validity. In the present paper, we argue that interrogating the validity of the mean involves, amongst other things, a better understanding of the person’s experiences, the meaning of their actions, at the time that the behavior of interest is carried out. Recently emerging approaches within Psychology and Cognitive Science have argued strongly that experience should play a more central role in our examination of behavioral data, but the relationship between experience and behavior remains very poorly understood. We outline some of the history of the science on this fraught relationship, as well as arguing that contemporary methods for studying experience fall into one of two categories. “Wide” approaches tend to incorporate naturalistic behavior settings, but sacrifice accuracy and reliability in behavioral measurement. “Narrow” approaches maintain controlled measurement of behavior, but involve too specific a sampling of experience, which obscures crucial temporal characteristics. We therefore argue for a novel, mid-range sampling technique, that extends Hurlburt’s descriptive experience sampling, and adapts it for the controlled setting of the laboratory. This controlled descriptive experience sampling may be an appropriate tool to help calibrate both the mean and the meaning of an experimental situation with one another. PMID:27242588

Occupational exposure to organic solvents during paint stripping and painting operations in the aeronautical industry.

PubMed

Vincent, R; Poirot, P; Subra, I; Rieger, B; Cicolella, A

1994-01-01

The exposure of workers to methylene chloride and phenol in an aeronautical workshop was measured during stripping of paint from a Boeing B 747. Methylene chloride exposure was measured during two work days by personal air sampling, while area sampling was used for phenol. During paint stripping operations, methylene chloride air concentrations ranged from 299.2 mg/m3 (83.1 ppm) to 1888.9 mg/m3 (524.7 ppm). The exposures to methylene chloride calculated for an 8-h work day ranged from 86 mg/m3 (23.9 ppm) to 1239.5 mg/m3 (344.3 ppm). In another aeronautical workshop, exposure to organic solvents, especially ethylene glycol monoethylether acetate (EGEEA), was controlled during the painting of an Airbus A 320. The external exposure to solvents and EGEEA was measured by means of individual air sampling. The estimation of internal exposure to EGEEA was made by measuring its urinary metabolite, ethoxyacetic acid (EAA). Both measurements were made during the course of 3 days. The biological samples were taken pre- and post-shift. During painting operations, methyl ethyl ketone, ethyl acetate, n-butyl alcohol, methyl isobutyl ketone, toluene, n-butyl acetate, ethylbenzene, xylenes and EGEEA were detected in working atmospheres. For these solvents, air concentrations ranged from 0.1 ppm to 69.1 ppm. EGEEA concentrations ranged from 29.2 mg/m3 (5.4 ppm) to 150.1 mg/m3 (27.8 ppm). For biological samples, the average concentrations of EAA were 108.4 mg/g creatinine in pre-shift and 139.4 mg/g creatinine in post-shift samples. Despite the fact that workers wore protective respiratory equipment during paint spraying operations, EEA urinary concentrations are high and suggest that percutaneous uptake is the main route of exposure for EGEEA.(ABSTRACT TRUNCATED AT 250 WORDS)

Phytochemical composition, antioxidant activity and HPLC fingerprinting profiles of three Pyrola species from different regions.

PubMed

Wang, Dongmei; He, Fengyuan; Lv, Zhenjiang; Li, Dengwu

2014-01-01

The present study was performed to investigate the variation of phytochemical composition, antioxidant activity and High Performance Liquid Chromatography (HPLC) fingerprinting profiles of three Pyrola species. Thirteen samples (eight P. decorata, three P. calliantha and two P. renifolia) were collected from different regions in China. The tannin, hyperoside and quercetin contents of all samples were determined by reverse-phase HPLC and varied within the range 9.77-34.75, 0.34-2.16 and 0.062-0.147 mg/g dry weigh, respectively. Total flavonoid content was evaluated and varied within the range 16.22-37.82 mg/g dry weight. Antioxidant activity was determined by DPPH assay, with IC50 ranging from 7.96 to 50.33 µg/ml, ABTS•+ and FRAP assay, within the range 612.66-1021.05 and 219.64-398.12 µmol equiv. Trolox/g, respectively. These results revealed that there were significant variations in phytochemical profiles and antioxidant activity among all samples. Due to the higher phytochemical content and significant antioxidant activity, P. calliantha was selected as the most valuable species, and the P. calliantha sample from Left banner of Alxa even possessed the strongest antioxidant activity among all the thirteen samples. Futhermore, Emei Mountain was proved to be the most suitable region for producing P. decorata. Moreover, in order to further evaluate the diversities and quality of Pyrola, HPLC fingerprint analysis coupled with hierarchical cluster and discrimination analyses were introduced to establish a simple, rapid and effective method for accurate identification, classification and quality assessment of Pyrola. Thirteen samples were divided into three groups consistent with their morphological classification. Two types of discriminant functions were generated and the ratio of discrimination was 100%. This method can identify different species of Pyrola and the same species from different regions of origin. Also, it can be used to compare and control the quality of Pyrola and other natural products prepared from them.

Phytochemical Composition, Antioxidant Activity and HPLC Fingerprinting Profiles of Three Pyrola Species from Different Regions

PubMed Central

Wang, Dongmei; He, Fengyuan; Lv, Zhenjiang; Li, Dengwu

2014-01-01

The present study was performed to investigate the variation of phytochemical composition, antioxidant activity and High Performance Liquid Chromatography (HPLC) fingerprinting profiles of three Pyrola species. Thirteen samples (eight P. decorata, three P. calliantha and two P. renifolia) were collected from different regions in China. The tannin, hyperoside and quercetin contents of all samples were determined by reverse-phase HPLC and varied within the range 9.77–34.75, 0.34–2.16 and 0.062–0.147 mg/g dry weigh, respectively. Total flavonoid content was evaluated and varied within the range 16.22–37.82 mg/g dry weight. Antioxidant activity was determined by DPPH assay, with IC50 ranging from 7.96 to 50.33 µg/ml, ABTS•+ and FRAP assay, within the range 612.66–1021.05 and 219.64–398.12 µmol equiv. Trolox/g, respectively. These results revealed that there were significant variations in phytochemical profiles and antioxidant activity among all samples. Due to the higher phytochemical content and significant antioxidant activity, P. calliantha was selected as the most valuable species, and the P. calliantha sample from Left banner of Alxa even possessed the strongest antioxidant activity among all the thirteen samples. Futhermore, Emei Mountain was proved to be the most suitable region for producing P. decorata. Moreover, in order to further evaluate the diversities and quality of Pyrola, HPLC fingerprint analysis coupled with hierarchical cluster and discrimination analyses were introduced to establish a simple, rapid and effective method for accurate identification, classification and quality assessment of Pyrola. Thirteen samples were divided into three groups consistent with their morphological classification. Two types of discriminant functions were generated and the ratio of discrimination was 100%. This method can identify different species of Pyrola and the same species from different regions of origin. Also, it can be used to compare and control the quality of Pyrola and other natural products prepared from them. PMID:24796694

Distribution of the two-sample t-test statistic following blinded sample size re-estimation.

PubMed

Lu, Kaifeng

2016-05-01

We consider the blinded sample size re-estimation based on the simple one-sample variance estimator at an interim analysis. We characterize the exact distribution of the standard two-sample t-test statistic at the final analysis. We describe a simulation algorithm for the evaluation of the probability of rejecting the null hypothesis at given treatment effect. We compare the blinded sample size re-estimation method with two unblinded methods with respect to the empirical type I error, the empirical power, and the empirical distribution of the standard deviation estimator and final sample size. We characterize the type I error inflation across the range of standardized non-inferiority margin for non-inferiority trials, and derive the adjusted significance level to ensure type I error control for given sample size of the internal pilot study. We show that the adjusted significance level increases as the sample size of the internal pilot study increases. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

A PLAUSIBLE ROLE FOR POLLEN-RESIDING MOLDS IN AGRICULTURAL PURPOSES.

PubMed

Belhadj, H; Harzallah, D; Dahamna, S; Ghadbane, M

2015-01-01

Pollen microbial content of 15 samples was investigated. Pollen was collected by honeybees. Total aerobic mesophilic count ranged from 3.00 to 5.48 Log CFU/g. Total mold and yeast count ranged from 2.3 to 6.99 Log CFU/g. Selected strains of isolated molds from pollen samples were characterized by conventional methods. Potent phytopathogenic and food spoilage species such as Penicillium sp., Alternaria alternata, Alternaria sp., Cladosporium werneckii, Mucor hiemalis, Rhizomucor pusillus, Aspergillus flavus, Aspergillus niger, Drechslera tritici-repentis, Verticillium albo-atrum, and Aspergillus alliaceus were recovered. Other fungal species with valuable biotechnological and plant diseases control purposes were isolated. They were characterized as Geotrichum candidum, Monilia sitophilia, and Sepedonium chrysospermum. Animal pathogenic molds were also isolated. Bee pollen may be considered as a source for a highly diverse fungal flora with different applications.

Biological monitoring of workers exposed to 4,4'-methylenediphenyl diisocyanate (MDI) in 19 French polyurethane industries.

PubMed

Robert, A; Ducos, P; Francin, J M; Marsan, P

2007-04-01

To study the range of urinary levels of 4,4'-methylenedianiline (MDA), a metabolite of methylenediphenyl diisocyanate (MDI), across factories in the polyurethane industries and to evaluate the validity of this biomarker to assess MDI occupational exposure. Workers exposed to MDI, as well as non-occupationally exposed subjects, were studied and pre- and post-shift urine samples were collected from 169 workers of 19 French factories and 120 controls. Details on work activities and practices were collected by a questionnaire and workers were classified into three job categories. The identification and quantification of the total urinary MDA were performed by high-performance liquid chromatography with electrochemical detection (HPLC/EC). For all the factories, MDA was detectable in 73% of the post-shift urine samples. These post-shift values, in the range of <0.10 (detection limit)-23.60 microg/l, were significantly higher than those of the pre-shift samples. Urinary MDA levels in the control group were in the range of < 0.10-0.80 microg/l. The degree of automation of the mixing operation (polyols and MDI) appears as a determinant in the extent of exposure levels. The highest amounts of MDA in urine were found in the spraying or hot processes. The excretion levels of the workers directly exposed to the hardener containing the MDI monomer were significantly higher than those of the other workers. In addition, skin exposure to MDI monomer or to polyurethane resin during the curing step were always associated with significant MDA levels in urine. Total MDA in post-shift urine samples is a reliable biomarker to assess occupational exposure to MDI in various industrial applications and to help factories to improve their manufacturing processes and working practices. A biological guiding value not exceeding 7 microg/l (5 microg/g creatinine) could be proposed in France.

Biological indicators of exposure to total and respirable aluminium dust fractions in a primary aluminium smelter.

PubMed Central

Röllin, H B; Theodorou, P; Cantrell, A C

1996-01-01

OBJECTIVES: The study attempts to define biological indicators of aluminium uptake and excretion in workers exposed to airborne aluminium compounds in a primary aluminium smelter. Also, this study defines the total and respirable aluminium dust fractions in two different potrooms, and correlates their concentrations with biological indicators in this group of workers. METHODS: Air was sampled at defined work sites. Non-destructive and conventional techniques were used to find total and respirable aluminium content of the dust. Blood and urine was collected from 84 volunteers employed at various work stations throughout the smelter and from two different cohorts of controls matched for sex, age, and socioeconomic status. Aluminium in serum samples and urine specimens was measured by flameless atomic absorption with a PE 4100 ZL spectrometer. RESULTS: The correlation of aluminium concentrations in serum and urine samples with the degree of exposure was assessed for three arbitrary exposure categories; low (0.036 mg Al/m3), medium (0.35 mg Al/m3) and high (1.47 mg Al/m3) as found in different areas of the smelter. At medium and high exposure, the ratio of respirable to total aluminium in the dust samples varied significantly. At high exposure, serum aluminium, although significantly raised, was still within the normal range of an unexposed population. The workers with low exposure excreted aluminium in urine at levels significantly higher than the controls, but still within the normal range of the population. However, potroom workers with medium and high exposure had significantly higher urinary aluminium than the normal range. CONCLUSIONS: It is concluded that only urinary aluminium constitutes a practical index of occupational exposure at or above 0.35 mg Al/m3, and that the respirable fraction of the dust may play a major role in the biological response to exposure to aluminium in a smelter environment. PMID:8758038

Caffeine, cognitive failures and health in a non-working community sample.

PubMed

Smith, Andrew P

2009-01-01

Most studies of the effects of caffeine on performance have been conducted in the laboratory and further information is required on the real-life effects of caffeine consumption on cognition. In addition, possible effects of caffeine consumption on a range of health outcomes should also be assessed in these studies to enable cost-benefit analyses to be conducted. Secondary analyses of a large epidemiological database (N = 3223 non-working participants, 57% female, with a mean age of 49.6 years, range 17-92 years) were conducted to examine associations between caffeine consumption (mean caffeine consumption was 140 mg/day, range 0-1800 mg) and cognitive failures (errors of memory, attention and action) in a non-working sample. Associations between caffeine consumption and physical and mental health problems were also examined. The study involved secondary analyses of a database formed by combining the Bristol Stress and Health at Work and Cardiff Health and Safety at Work studies. Associations between caffeine consumption and frequency of cognitive failures and health outcomes were examined in a sample of non-workers. After controlling for possible confounding factors significant associations between caffeine consumption and fewer cognitive failures were observed. Initial analyses suggested that many health variables were associated with regular level of caffeine consumption. However, most of the significant effects of caffeine disappeared when demographic and lifestyle factors were controlled for. Consumption of caffeine was, however, associated with a reduced risk of depression. These effects were also observed in separate analyses examining the source of the caffeine (coffee and tea). Overall, the results show that caffeine consumption may benefit cognitive functioning in a non-working population. This confirms earlier findings from working samples. This beneficial effect of caffeine was not associated with negative health consequences. Indeed, consumption of caffeine was found to be associated with a reduced risk of depression.

Investigating the relationship between FMR1 allele length and cognitive ability in children: a subtle effect of the normal allele range on the normal ability range?

PubMed

Loat, C S; Craig, G; Plomin, R; Craig, I W

2006-09-01

The FMR1 gene contains a trinucleotide repeat tract which can expand from a normal size of around 30 repeats to over 200 repeats, causing mental retardation (Fragile X Syndrome). Evidence suggests that premutation males (55-200 repeats) are susceptible to a late-onset tremor/ataxia syndrome and females to premature ovarian failure, and that intermediate alleles ( approximately 41-55 repeats) and premutations may be in excess in samples with special educational needs. We explored the relationship between FMR1 allele length and cognitive ability in 621 low ability and control children assessed at 4 and 7 years, as well as 122 students with high IQ. The low and high ability and control samples showed no between-group differences in incidence of longer alleles. In males there was a significant negative correlation between allele length and non-verbal ability at 4 years (p = 0.048), academic achievement in maths (p = 0.003) and English (p = 0.011) at 7 years, and IQ in the high ability group (p = 0.018). There was a significant negative correlation between allele length and a standardised score for IQ and general cognitive ability at age 7 in the entire male sample (p = 0.002). This suggests that, within the normal spectrum of allele length, increased repeat numbers may have a limiting influence on cognitive performance.

Circularly polarized microwaves for magnetic resonance study in the GHz range: Application to nitrogen-vacancy in diamonds

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

Mrózek, M., E-mail: mariusz.mrozek@uj.edu.pl; Rudnicki, D. S.; Gawlik, W.

2015-07-06

The ability to create time-dependent magnetic fields of controlled polarization is essential for many experiments with magnetic resonance. We describe a microstrip circuit that allows us to generate strong magnetic field at microwave frequencies with arbitrary adjusted polarization. The circuit performance is demonstrated by applying it to an optically detected magnetic resonance and Rabi nutation experiments in nitrogen-vacancy color centers in diamond. Thanks to high efficiency of the proposed microstrip circuit and degree of circular polarization of 85%; it is possible to address the specific spin states of a diamond sample using a low power microwave generator. The circuit maymore » be applied to a wide range of magnetic resonance experiments with a well-controlled polarization of microwaves.« less

Video Toroid Cavity Imager

DOEpatents

Gerald, II, Rex E.; Sanchez, Jairo; Rathke, Jerome W.

2004-08-10

A video toroid cavity imager for in situ measurement of electrochemical properties of an electrolytic material sample includes a cylindrical toroid cavity resonator containing the sample and employs NMR and video imaging for providing high-resolution spectral and visual information of molecular characteristics of the sample on a real-time basis. A large magnetic field is applied to the sample under controlled temperature and pressure conditions to simultaneously provide NMR spectroscopy and video imaging capabilities for investigating electrochemical transformations of materials or the evolution of long-range molecular aggregation during cooling of hydrocarbon melts. The video toroid cavity imager includes a miniature commercial video camera with an adjustable lens, a modified compression coin cell imager with a fiat circular principal detector element, and a sample mounted on a transparent circular glass disk, and provides NMR information as well as a video image of a sample, such as a polymer film, with micrometer resolution.

Laboratory measurements of electric properties of composite mine dump samples from Colorado and New Mexico

USGS Publications Warehouse

Anderson, Anita L.; Campbell, David L.; Beanland, Shay

2001-01-01

Individual mine waste samples were collected and combined to form one composite sample at each of eight mine dump sites in Colorado and New Mexico. The samples were air-dried and sieved to determine the geochemical composition of their <2mm size fraction. Splits of the samples were then rehydrated and their electrical properties were measured in the US Geological Survey Petrophysical Laboratory, Denver, Colorado (PetLab). The PetLab measurements were done twice: in 1999, using convenient amounts of rehydration water ranging from 5% to 8%; and in 2000, using carefully controlled rehydrations to 5% and 10% water. This report gives geochemical analyses of the <2mm size fraction of the composite samples (Appendix A), PetLab graphs of the 1999 measurements (Appendix B), Petlab graphs of the 2000 measurements (Appendix C), and Cole-Cole models of the PetLab data from the 2000 measurements (Appendix D).

Parkinson's Impulse-Control Scale for the Severity Rating of Impulse-Control Behaviors in Parkinson's Disease: A Semistructured Clinical Assessment Tool.

PubMed

Okai, David; Askey-Jones, Sally; Mack, Joel; Martin, Anne; Chaudhuri, Kallol Ray; Samuel, Michael; David, Anthony S; Brown, Richard G

2016-01-01

Impulse-control behaviors (ICBs) are increasingly recognized in Parkinson's disease (PD) as drug-related effects of dopaminergic mediation that occur in 15% to 35% of patients with PD. The authors describe the design and evaluation of a new, clinician-rated severity scale for the assessment of syndromal and subsyndromal forms of impulse-control disorders (ICDs), simple (punding) and complex (hobbyism) repetitive behaviors, and compulsive overuse of medication (dopamine dysregulation syndrome). The Parkinson's Impulse-Control Scale (PICS), the first PD-specific, semistructured interview to cover the full range of PD-related ICBs, is described along with initial evidence on its clinimetric properties including interrater reliability, discriminant validity and sensitivity to change. A convenience sample of PD patients with ICBs and those without were administered a semistructured interview (n = 92). The scale distinguished between those with and without clinically detected ICBs and between patients with syndromal ICD and subsyndromal ICB (receiver operating characteristic areas under the curve, 92%-95%). Cutoff values were suggested, and substantial agreement was reported on weighted kappa (Κ) values for clinician-clinician rating of severity (Κ = 0.92). Significant improvements were detected on the scale after a randomized controlled trial of cognitive-behavioral therapy and medication adjustment ( t [22] = 5.47; P < 0.001). The PICS appears to be a reliable measure of the full range of PD ICBs with good levels of interrater reliability. It may provide a useful measure to assess the severity of ICBs and monitor change in clinical and research settings; although, given the specialized centers used for recruitment of this sample, further psychometric evaluation is required.

Fungal flora and aflatoxin contamination in Pakistani wheat kernels (Triticum aestivum L.) and their attribution in seed germination.

PubMed

Asghar, Muhammad Asif; Ahmed, Aftab; Iqbal, Javed; Zahir, Erum; Nauman, Hina

2016-07-01

This study aimed to isolate fungal pathogens and to subsequently quantify aflatoxin (AF; B 1  + B 2  + G 1  + G 2 ) contamination in wheat crops grown in Pakistan. Accordingly, a total of 185 wheat samples were collected from different areas of Pakistan and numerous potent fungal pathogens were isolated. AF contamination attributed to the presence of intoxicating fungal pathogens and resulting metabolic activities were quantified using a high performance liquid chromatography-fluorescence detector coupled with postcolumn derivatization. Additionally, the effect of fungal pathogens on seed germination was also examined. The results obtained showed that 50% of tested wheat samples were found to be contaminated with a diverse range of fungal species. The rate of recurrence of fungal pathogens were Aspergillus 31%, Penicillium 9%, Fusarium 8%, Rhizopus 3%, and Alternaria 2%. The presence of Tilletia indica and Claviceps purpurea species was found to be inevident in all tested wheat samples. AFB 1 contamination was detected in 48 (26.0%) samples and AFB 2 in 13 (7.0%) samples. AFG 1 and AFG 2 were not found in any of the tested samples. The contamination range of AFB 1 and AFB 2 was 0.05-4.78 μg/kg and 0.02-0.48 μg/kg, respectively. The total amount of AFs (B 1  + B 2 ) found in 48 (26.0%) samples had a mean level of 0.53 ± 0.40 μg/kg and a contamination range of 0.02-5.26 μg/kg. The overall results showed that in 137 (74.0%) samples, AFs were not found within detectable limits. Furthermore, in 180 (97.2%) samples, AF levels were found to be below the maximum tolerated levels (MTL) recommended by the European Union (4 μg/kg). In five (2.7%) samples, AF contamination was higher than the MTL of the European Union. However, these samples were fit for human consumption with reference to the MTL (20 μg/kg) assigned by the USA (Food and Drug Administration and Food and Agriculture Organization) and Pakistan (Pakistan Standards and Quality Control Authority). Germination rates in healthy and contaminated wheat kernels were 84.6% and 45.2%, respectively. Based on the obtained results, it was concluded that the levels of fungal pathogen and AF contamination in Pakistani-grown wheat are not a potential threat to consumer health. However, control procedures along with a strict monitoring policy are mandatory to further minimize the prevalence of fungal carriers and the potency of AFs in crops cultivated in Pakistan. Copyright © 2016. Published by Elsevier B.V.

HPLC fingerprint analysis combined with chemometrics for pattern recognition of ginger.

PubMed

Feng, Xu; Kong, Weijun; Wei, Jianhe; Ou-Yang, Zhen; Yang, Meihua

2014-03-01

Ginger, the fresh rhizome of Zingiber officinale Rosc. (Zingiberaceae), has been used worldwide; however, for a long time, there has been no standard approbated internationally for its quality control. To establish an efficacious and combinational method and pattern recognition technique for quality control of ginger. A simple, accurate and reliable method based on high-performance liquid chromatography with photodiode array (HPLC-PDA) detection was developed for establishing the chemical fingerprints of 10 batches of ginger from different markets in China. The method was validated in terms of precision, reproducibility and stability; and the relative standard deviations were all less than 1.57%. On the basis of this method, the fingerprints of 10 batches of ginger samples were obtained, which showed 16 common peaks. Coupled with similarity evaluation software, the similarities between each fingerprint of the sample and the simulative mean chromatogram were in the range of 0.998-1.000. Then, the chemometric techniques, including similarity analysis, hierarchical clustering analysis and principal component analysis were applied to classify the ginger samples. Consistent results were obtained to show that ginger samples could be successfully classified into two groups. This study revealed that HPLC-PDA method was simple, sensitive and reliable for fingerprint analysis, and moreover, for pattern recognition and quality control of ginger.

Application of laser spectroscopy for measurement of exhaled ethane in patients with lung cancer.

PubMed

Skeldon, K D; McMillan, L C; Wyse, C A; Monk, S D; Gibson, G; Patterson, C; France, T; Longbottom, C; Padgett, M J

2006-02-01

There is increasing interest in ethane (C(2)H(6)) in exhaled breath as a non-invasive marker of oxidative stress (OS) and thereby a potential indicator of disease. However, the lack of real-time measurement techniques has limited progress in the field. Here we report on a novel Tunable Diode Laser Spectrometer (TDLS) applied to the analysis of exhaled ethane in patients with lung cancer. The patient group (n=52) comprised randomly selected patients presenting at a respiratory clinic. Of these, a sub-group (n=12) was subsequently diagnosed with lung cancer. An age-matched group (n=12) corresponding to the lung cancer group was taken from a larger control group of healthy adults (n=58). The concentration of ethane in a single exhaled breath sample collected from all subjects was later measured using the TDLS. This technique is capable of real-time analysis of samples with accuracy 0.1 parts per billion (ppb), over 10 times less than typical ambient levels in the northern hemisphere. After correcting for ambient background, ethane in the control group (26% smokers) ranged from 0 to 10.54 ppb (median of 1.9 ppb) while ethane in the lung cancer patients (42% smokers) ranged from 0 to 7.6 ppb (median of 0.7 ppb). Ethane among the non-lung cancer patients presenting for investigation of respiratory disease ranged from 0 to 25 ppb (median 1.45 ppb). We conclude that, while the TDLS proved effective for accurate and rapid sample analysis, there was no significant difference in exhaled ethane among any of the subject groups. Comments are made on the suitability of the technique for monitoring applications.

Magneto-optic superlattice thin films: Fabrication, structural and magnetic characterization

NASA Technical Reports Server (NTRS)

Falco, C. M.; Engel, B. N.; Vanleeuwen, R. A.; Yu, J.

1993-01-01

During this quarter studies were extended to determine the electronic contribution to the perpendicular interface anisotropy in Co-based multilayers. Using in situ Kerr effect measurements, the influences of different transition metals (TM = Ag, Au, Cu, and Pd) on the magnetic properties of single-crystal Co films grown on Pd (111) and Au (111) surfaces are investigated. Last quarter the discovery of a large peak in the perpendicular anisotropy when approximately one monolayer of Cu or Ag is deposited on the Co surface was reported. We now have added a computer-controlled stepper-motor drive to our MBE sample transfer mechanism. The motor allows us to move the sample at a constant velocity from behind a shutter during deposition. The film, therefore, is deposited as a wedge with a linear variation of thickness across the substrate. In this way, a continuous range of coverage on a single sample is studied. The stepper motor also provides the necessary control for precisely positioning the sample in the laser beam for Kerr effect measurements at the different coverages.

Insights in groundwater organic matter from Liquid Chromatography-Organic Carbon Detection

NASA Astrophysics Data System (ADS)

Rutlidge, H.; Oudone, P.; McDonough, L.; Andersen, M. S.; Baker, A.; Meredith, K.; O'Carroll, D. M.

2017-12-01

Understanding the processes that control the concentration and characteristics of organic matter in groundwater has important implications for the terrestrial global carbon budget. Liquid Chromatography - Organic Carbon Detection (LC-OCD) is a size-exclusion based chromatography technique that separates the organic carbon into molecular weight size fractions of biopolymers, humic substances, building blocks (degradation products of humic substances), low molecular weight acids and low molecular weight neutrals. Groundwater and surface water samples were collected from a range of locations in Australia representing different surface soil, land cover, recharge type and hydrological properties. At one site hyporheic zone samples were also collected from beneath a stream. The results showed a general decrease in the aromaticity and molecular weight indices going from surface water, hyporheic downwelling and groundwater samples. The aquifer substrate also affected the organic composition. For example, groundwater samples collected from a zone of fractured rock showed a relative decrease in the proportion of humic substances, suggestive of sorption or degradation of humic substances. This work demonstrates the potential for using LC-OCD in elucidating the processes that control the concentration and characteristics of organic matter in groundwater.

The Influence of trisomy 21 on facial form and variability.

PubMed

Starbuck, John M; Cole, Theodore M; Reeves, Roger H; Richtsmeier, Joan T

2017-11-01

Triplication of chromosome 21 (trisomy 21) results in Down syndrome (DS), the most common live-born human aneuploidy. Individuals with DS have a unique facial appearance that can include form changes and altered variability. Using 3D photogrammatic images, 3D coordinate locations of 20 anatomical landmarks, and Euclidean Distance Matrix Analysis methods, we quantitatively test the hypothesis that children with DS (n = 55) exhibit facial form and variance differences relative to two different age-matched (4-12 years) control samples of euploid individuals: biological siblings of individuals with DS (n = 55) and euploid individuals without a sibling with DS (n = 55). Approximately 36% of measurements differ significantly between DS and DS-sibling samples, whereas 46% differ significantly between DS and unrelated control samples. Nearly 14% of measurements differ significantly in variance between DS and DS sibling samples, while 18% of measurements differ significantly in variance between DS and unrelated euploid control samples. Of those measures that showed a significant difference in variance, all were relatively increased in the sample of DS individuals. These results indicate that faces of children with DS are quantitatively more similar to their siblings than to unrelated euploid individuals and exhibit consistent, but slightly increased variation with most individuals falling within the range of normal variation established by euploid samples. These observations provide indirect evidence of the strength of the genetic underpinnings of the resemblance between relatives and the resistance of craniofacial development to genetic perturbations caused by trisomy 21, while underscoring the complexity of the genotype-phenotype map. © 2017 Wiley Periodicals, Inc.

A new approach for freezing of aqueous solutions under active control of the nucleation temperature.

PubMed

Petersen, Ansgar; Schneider, Hendrik; Rau, Guenter; Glasmacher, Birgit

2006-10-01

An experimental setup for controlled freezing of aqueous solutions is introduced. The special feature is a mechanism to actively control the nucleation temperature via electrofreezing: an ice nucleus generated at a platinum electrode by the application of an electric high voltage pulse initiates the crystallization of the sample. Using electrofreezing, the nucleation temperature in pure water can be precisely adjusted to a desired value over the whole temperature range between a maximum temperature Tn(max) close to the melting point and the temperature of spontaneous nucleation. However, the presence of additives can inhibit the nucleus formation. The influence of hydroxyethylstarch (HES), glucose, glycerol, additives commonly used in cryobiology, and NaCl on Tn(max) were investigated. While the decrease showed to be moderate for the non-ionic additives, the hindrance of nucleation by ionic NaCl makes the direct application of electrofreezing in solutions with physiological salt concentrations impossible. Therefore, in the multi-sample freezing device presented in this paper, the ice nucleus is produced in a separate volume of pure water inside an electrode cap. This way, the nucleus formation becomes independent of the sample composition. Using electrofreezing rather than conventional seeding methods allows automated freezing of many samples under equal conditions. Experiments performed with model solutions show the reliability and repeatability of this method to start crystallization in the test samples at different specified temperatures. The setup was designed to freeze samples of small volume for basic investigations in the field of cryopreservation and freeze-drying, but the mode of operation might be interesting for many other applications where a controlled nucleation of aqueous solutions is of importance.

Face validity and reliability of a pictorial instrument for assessing fundamental movement skill perceived competence in young children.

PubMed

Barnett, Lisa M; Ridgers, Nicola D; Zask, Avigdor; Salmon, Jo

2015-01-01

To determine reliability and face validity of an instrument to assess young children's perceived fundamental movement skill competence. Validation and reliability study. A pictorial instrument based on the Test Gross Motor Development-2 assessed perceived locomotor (six skills) and object control (six skills) competence using the format and item structure from the physical competence subscale of the Pictorial Scale of Perceived Competence and Acceptance for Young Children. Sample 1 completed object control items in May (n=32) and locomotor items in October 2012 (n=23) at two time points seven days apart. Children were asked at the end of the test-retest their understanding of what was happening in each picture to determine face validity. Sample 2 (n=58) completed 12 items in November 2012 on a single occasion to test internal reliability only. Sample 1 children were aged 5-7 years (M=6.0, SD=0.8) at object control assessment and 5-8 years at locomotor assessment (M=6.5, SD=0.9). Sample 2 children were aged 6-8 years (M=7.2, SD=0.73). Intra-class correlations assessed in Sample 1 children were excellent for object control (intra-class correlation=0.78), locomotor (intra-class correlation=0.82) and all 12 skills (intra-class correlations=0.83). Face validity was acceptable. Internal consistency was adequate in both samples for each subscale and all 12 skills (alpha range 0.60-0.81). This study has provided preliminary evidence for instrument reliability and face validity. This enables future alignment between the measurement of perceived and actual fundamental movement skill competence in young children. Crown Copyright © 2014. Published by Elsevier Ltd. All rights reserved.

Intermittent control: a computational theory of human control.

PubMed

Gawthrop, Peter; Loram, Ian; Lakie, Martin; Gollee, Henrik

2011-02-01

The paradigm of continuous control using internal models has advanced understanding of human motor control. However, this paradigm ignores some aspects of human control, including intermittent feedback, serial ballistic control, triggered responses and refractory periods. It is shown that event-driven intermittent control provides a framework to explain the behaviour of the human operator under a wider range of conditions than continuous control. Continuous control is included as a special case, but sampling, system matched hold, an intermittent predictor and an event trigger allow serial open-loop trajectories using intermittent feedback. The implementation here may be described as "continuous observation, intermittent action". Beyond explaining unimodal regulation distributions in common with continuous control, these features naturally explain refractoriness and bimodal stabilisation distributions observed in double stimulus tracking experiments and quiet standing, respectively. Moreover, given that human control systems contain significant time delays, a biological-cybernetic rationale favours intermittent over continuous control: intermittent predictive control is computationally less demanding than continuous predictive control. A standard continuous-time predictive control model of the human operator is used as the underlying design method for an event-driven intermittent controller. It is shown that when event thresholds are small and sampling is regular, the intermittent controller can masquerade as the underlying continuous-time controller and thus, under these conditions, the continuous-time and intermittent controller cannot be distinguished. This explains why the intermittent control hypothesis is consistent with the continuous control hypothesis for certain experimental conditions.

Thermoluminescence of meteorites and their orbits

NASA Astrophysics Data System (ADS)

Melcher, C. L.

1981-01-01

The thermoluminescence levels of 45 ordinary chondrites are measured in order to provide information on the orbital characteristics of the meteorites before impact. Glow curves of the photon emission response of powdered samples of the meteorites to temperatures up to 550 C in the natural state and following irradiation by a laboratory test dose of 110,000 rad were obtained as functions of terrestrial age and compared to those of samples of the Pribram, Lost City and Innisfree meteorites, for which accurate orbital data is available. The thermoluminescence levels in 40 out of 42 meteorites are found to be similar to those of the three control samples, indicating that the vast majority of ordinary chondrites that survive atmospheric entry have perihelia in the range 0.8-1 AU. Of the remaining two, Farmville is observed to exhibit an unusually large gradient in thermoluminescence levels with sample depth, which may be a result of a temperature gradient arising in a slowly rotating meteorite. Finally, the thermoluminescence measured in the Malakal meteorite is found to be two orders of magnitude lower than control samples, which is best explained by thermal draining by solar heating in an orbit with a perihelion distance of 0.5 to 0.6 AU.

Synthesis and characterisation of mucoadhesive thiolated polyallylamine.

PubMed

Duggan, Sarah; Hughes, Helen; Owens, Eleanor; Duggan, Elaine; Cummins, Wayne; O' Donovan, Orla

2016-02-29

The thiolation of polyallylamine (PAAm) for use in mucoadhesive drug delivery has been achieved. PAAm was reacted with different ratios of Traut's reagent, yielding products with thiol contents ranging from 134-487μmol/g. Full mucoadhesive characterisation of the thiolated PAAm samples was conducted using swelling studies, mucoadhesive testing on porcine intestinal tissue and rheology. Both swelling and cohesive properties of the thiolated PAAm products were vastly improved in comparison to an unmodified PAAm control. The swelling abilities of the thiolated samples were high and the degree of thiolation of the products affected the initial rate of swelling. High levels of mucoadhesion were demonstrated by the thiolated PAAm samples, with adhesion times of greater than 24h measured for all three samples and, thus, thiol content did not appear to influence mucoadhesion. Rheological studies of the thiolated PAAm samples showed an increase in G' and G″ values upon the addition of a mucin solution which was not observed in the unmodified control, again highlighting the mucoadhesive interactions between these thiolated polymers and mucin. The synthesis of thiolated PAAm by reaction with Traut's reagent and resulting mucoadhesive properties demonstrates its potential for use a mucoadhesive drug delivery device. Copyright © 2016 Elsevier B.V. All rights reserved.

Concentration and characteristics of depleted uranium in water, air and biological samples collected in Serbia and Montenegro.

PubMed

Jia, Guogang; Belli, Maria; Sansone, Umberto; Rosamilia, Silvia; Gaudino, Stefania

2005-09-01

During the Balkan conflicts, in 1995 and 1999, depleted uranium (DU) rounds were employed and were left in the battlefield. Health concern is related to the risk arising from contamination of the environment with DU penetrators and dust. In order to evaluate the impact of DU on the environment and population in Serbia and Montenegro, radiological surveys of DU in water, air and biological samples were carried out over the period 27 October-5 November 2001. The uranium isotopic concentrations in biological samples collected in Serbia and Montenegro, mainly lichens and barks, were found to be in the range of 0.67-704 Bqkg(-1) for (238)U, 0.48-93.9 Bqkg(-1) for (234)U and 0.02-12.2 Bqkg(-1) for (235)U, showing uranium levels to be higher than in the samples collected at the control sites. Moreover, (236)U was detectable in some of the samples. The isotopic ratios of (234)U/(238)U showed DU to be detectable in many biological samples at all examined sites, especially in Montenegro, indicating widespread ground-surface DU contamination, albeit at very low level. The uranium isotopic concentrations in air obtained from the air filter samples collected in Serbia and Montenegro were found to be in the range of 1.99-42.1 microBqm(-3) for (238)U, 0.96-38.0 microBqm(-3) for (234)U, and 0.05-1.83 microBqm(-3) for (235)U, being in the typical range of natural uranium values. Thus said, most of the air samples are DU positive, this fact agreeing well with the widespread DU contamination detected in the biological samples. The uranium concentrations in water samples collected in Serbia and Montenegro were found to be in the range of 0.40-21.9 mBql(-1) for (238)U, 0.27-28.1 mBql(-1) for (234)U, and 0.01-0.88 mBql(-1) for (235)U, these values being much lower than those in mineral water found in central Italy and below the WHO guideline for drinking water. From a radiotoxicological point of view, at this moment there is no significant radiological risk related to these investigated sites in terms of possible DU contamination of water, air and/or plants.

A role for high frequency hydrochemical sampling in long term ecosystem studies

NASA Astrophysics Data System (ADS)

Sebestyen, S. D.; Shanley, J. B.; Boyer, E. W.; Kendall, C.

2007-12-01

Monitoring of surface waters for major chemical constituents is needed to assess long-term trends and responses to ecological disturbance. However, the typical fixed-interval (weekly, monthly, or quarterly) sampling schemes of most long-term ecosystem studies may not capture the full range of stream chemical variation and do not always provide enough information to discern the landscape processes that control surface water chemistry and solute loadings. To expand upon traditional hydrochemical monitoring, we collected high frequency event-based surface water samples at an upland, forested basin of the Sleepers River Research Watershed (Vermont, USA), one of five intensively studied sites in the Water, Energy, and Biogeochemical Budgets (WEBB) program of the US Geological Survey. We present several examples that highlight the importance of linking long-term weekly data with intensive, high frequency sampling. We used end-member mixing analysis and isotopic approaches to trace sources of stream nutrients (e.g. nitrate, dissolved organic carbon) and quantified how atmospheric pollutants (e.g. nitrogen, sulfate, and mercury) affect stream chemistry. High frequency sampling generates large numbers of samples and is both labor and resource intensive but yields insights into ecosystem functions that are not readily discerned from less-frequent sampling. As the ecological community contemplates the scope and foci of environmental observatories as benchmarks for deciphering the effects of natural and anthropogenic change, incorporating high frequency hydrochemical sampling will further our understanding of ecosystem functions across a range of ecosystem types and disturbance effects.

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.

Humboldt's spa: microbial diversity is controlled by temperature in geothermal environments

PubMed Central

Sharp, Christine E; Brady, Allyson L; Sharp, Glen H; Grasby, Stephen E; Stott, Matthew B; Dunfield, Peter F

2014-01-01

Over 200 years ago Alexander von Humboldt (1808) observed that plant and animal diversity peaks at tropical latitudes and decreases toward the poles, a trend he attributed to more favorable temperatures in the tropics. Studies to date suggest that this temperature–diversity gradient is weak or nonexistent for Bacteria and Archaea. To test the impacts of temperature as well as pH on bacterial and archaeal diversity, we performed pyrotag sequencing of 16S rRNA genes retrieved from 165 soil, sediment and biomat samples of 36 geothermal areas in Canada and New Zealand, covering a temperature range of 7.5–99 °C and a pH range of 1.8–9.0. This represents the widest ranges of temperature and pH yet examined in a single microbial diversity study. Species richness and diversity indices were strongly correlated to temperature, with R2 values up to 0.62 for neutral–alkaline springs. The distributions were unimodal, with peak diversity at 24 °C and decreasing diversity at higher and lower temperature extremes. There was also a significant pH effect on diversity; however, in contrast to previous studies of soil microbial diversity, pH explained less of the variability (13–20%) than temperature in the geothermal samples. No correlation was observed between diversity values and latitude from the equator, and we therefore infer a direct temperature effect in our data set. These results demonstrate that temperature exerts a strong control on microbial diversity when considered over most of the temperature range within which life is possible. PMID:24430481

Humboldt's spa: microbial diversity is controlled by temperature in geothermal environments.

PubMed

Sharp, Christine E; Brady, Allyson L; Sharp, Glen H; Grasby, Stephen E; Stott, Matthew B; Dunfield, Peter F

2014-06-01

Over 200 years ago Alexander von Humboldt (1808) observed that plant and animal diversity peaks at tropical latitudes and decreases toward the poles, a trend he attributed to more favorable temperatures in the tropics. Studies to date suggest that this temperature-diversity gradient is weak or nonexistent for Bacteria and Archaea. To test the impacts of temperature as well as pH on bacterial and archaeal diversity, we performed pyrotag sequencing of 16S rRNA genes retrieved from 165 soil, sediment and biomat samples of 36 geothermal areas in Canada and New Zealand, covering a temperature range of 7.5-99 °C and a pH range of 1.8-9.0. This represents the widest ranges of temperature and pH yet examined in a single microbial diversity study. Species richness and diversity indices were strongly correlated to temperature, with R(2) values up to 0.62 for neutral-alkaline springs. The distributions were unimodal, with peak diversity at 24 °C and decreasing diversity at higher and lower temperature extremes. There was also a significant pH effect on diversity; however, in contrast to previous studies of soil microbial diversity, pH explained less of the variability (13-20%) than temperature in the geothermal samples. No correlation was observed between diversity values and latitude from the equator, and we therefore infer a direct temperature effect in our data set. These results demonstrate that temperature exerts a strong control on microbial diversity when considered over most of the temperature range within which life is possible.

Electrochemically-Induced Redox Reactions in Basalt at High Pressure and Temperature: An Iron and Vanadium K-edge XANES Study

NASA Astrophysics Data System (ADS)

Kavner, A.; Walker, D.; Newville, M.; Sutton, S. R.

2005-12-01

An applied electric field across a silicate sample at high pressures and temperatures in a piston cylinder apparatus can generate a wide range of oxidation states of polyvalent cations within a single experiment. If two or more polyvalent cations are included, this technique can be used to cross-calibrate oxybarometers within a single experiment. The redox state of Fe and V within a partially melted basaltic silicate was manipulated in situ in a piston-cylinder experiment with a DC power supply providing a source and sink of electrons to the sample. A 1V electrical potential differential was applied across vanadium-doped and Fe-bearing synthetic basalt samples for 24 hrs. at 20 kbar and 1400°C in a specially-designed piston cylinder sample assembly. Three experiments were performed: a control sample with no applied voltage, one with bottom cathode and top anode, and a third with top cathode and bottom anode. Synchrotron-based x-ray absorption near edge structure (XANES) spectroscopy was used to provide spot analysis of iron and vanadium oxidation states with 5μm x 5μm spatial resolution throughout the recovered samples. Systematic spatial changes of increasing oxidation states of V and Fe were observed approaching the anode. The differences in oxidation states were mapped to a corresponding local effective oxygen fugacity by comparison and extension of a calibration of vanadium oxidation states as a function of controlled oxygen fugacity from a previous study (Sutton et al., 2005, GCA, vol. 69, pp. 2333-2348). The vanadium mapping indicates that a 1V potential drop across the sample induces effective oxygen fugacity perturbations in excess of ten orders of magnitude. The presence of both Fe and V within the same sample provides a wide range of oxygen fugacity cross-calibration in these recovered samples. A relationship between oxygen fugacity and electrochemical driving force is derived. The experimental results are in good agreement with the derived relationship between applied electrochemical potential difference (the 1V in this experiment), and corresponding calculated oxygen fugacity.

Development of a continuous flow thermal gradient diffusion chamber for ice nucleation studies

NASA Astrophysics Data System (ADS)

Rogers, David C.

A supercooled continuous flow, thermal gradient diffusion chamber has been developed to study the ice nucleating properties of natural or artificial aerosols. The chamber has concentric cylinder geometry with the cylinder axis alignment and airflow vertically downward. Sample airflow is 1 l min -1 and occupies the central 10% of the annular lamina; it is separated from the ice-covered walls by filtered sheath air. The wall temperatures are independently controlled over the range from about -4°C to -25°C, so that the vapor concentration at the location of the sample lamina can be set to a well defined value between ice saturation and a few percent water supersaturation. There is a range of temperature and supersaturation values across the sample region; for lamina center conditions of -15°C and +1% with respect to water, the range is -14.6 to -15.4°C and +0.53 to +1.31%. Errors in temperature control produce variations estimated as ±0.1°C and ±0.23%. Typical sample residence time is about 10 s. Ice crystals which form on active nuclei are detected optically at the outlet end of the chamber. To enhance the size difference between ice crystals and cloud droplets, the downstream 25% of the warm ice wall is covered with a thermally insulating vapor barrier which reduces the vapor concentration to ice saturation at the cold wall temperature, so cloud droplets evaporate. A mathematical model was developed to describe the temperature and vapor fields and to calculate the growth, evaporation, and sedimentation of water and ice particles. At 1% water supersaturation, the model predicts that ice particles will grow to about 5 μm diameter, and cloud droplets will achieve about 1 μm before they reach the evaporation section of the chamber. A different model was developed to describe the steady state airflow profile and location of the sample lamina. Experimental tests of the chamber were performed to characterize the airflow, to assess the ability of the technique to detect silver iodide ice nucleating aerosols and to distinguish ice crystals from water droplets.

Analysis of sweet diterpene glycosides from Stevia rebaudiana: improved HPLC method.

PubMed

Kolb, N; Herrera, J L; Ferreyra, D J; Uliana, R F

2001-10-01

An improved analytical method was developed which may be applied to quality control of stevioside and rebaudioside A contents in dried leaves of Stevia rebaudiana before processing; in a selective sampling program searching for plants of higher yield in diterpene glycosides content; or when a large number of samples are sent to the laboratory for analysis. The procedure developed involves two steps: solvent extraction followed by an isocratic HPLC analysis. The sample, 1 g of dried leaves of S. rebaudiana, is ground and solvent-extracted with EtOH 70% (w/w) in Erlenmeyer flasks by shaking for 30 min in a 70 degrees C water bath. After the extract was cooled, it was filtered and analyzed by HPLC using an NH(2) column (250 x 4.6 mm) and a mixture of acetonitrile/water (80:20, v/v) as mobile phase, pH 5 adjusted with acetic acid. The detection was in the UV range at 210 nm (0.04 AUFS). Quantitation was performed by means of an external standard calibration curve for each analyte which had been obtained from standard solutions of pure stevioside and rebaudioside A. Working under these conditions there were no observed interference effects. The method saves time in sample preparation, and reduces sample handling and chromatographic analysis time, while having little loss of precision [coefficient of variation (CV%) between 1.8% and 3.0%] and recovery [between 98.5% and 100.5%]. The method was applied to 30 samples of S. rebaudiana from Misiones (Northeastern Argentina), and the stevioside content found ranged between 3.78 and 9.75% (weight) whereas Rebaudioside A content ranged between 1.62 and 7.27% (weight).

Validation of a method for the determination of zolpidem in human plasma using LC with fluorescence detection.

PubMed

Ring, P R; Bostick, J M

2000-04-01

A sensitive and selective high-performance liquid chromatography (HPLC) method was developed for the determination of zolpidem in human plasma. Zolpidem and the internal standard (trazodone) were extracted from human plasma that had been made basic. The basic sample was loaded onto a conditioned Bond Elut C18 cartridge, rinsed with water and eluted with methanol. Forty microliters were then injected onto the LC system. Separation was achieved on a C18 column (150 x 4.6 mm, 5 microm) with a mobile phase composed of acetonitrile:50 mM potassium phosphate monobasic at pH 6.0 (4:6, v/v). Detection was by fluorescence, with excitation at 254 nm and emission at 400 nm. The retention times of zolpidem and internal standard were approximately 4.7 and 5.3 min, respectively. The LC run time was 8 min. The assay was linear in concentration range 1-400 ng/ml for zolpidem in human plasma. The analysis of quality control samples for zolpidem (3, 30, and 300 ng/ml) demonstrated excellent precision with relative standard deviations (RSD) of 3.7, 4.6, and 3.0%, respectively (n = 18). The method was accurate with all intraday (n = 6) and overall (n = 18) mean concentrations within 5.8% from nominal at all quality control sample concentrations. This method was also performed using a Gilson Aspec XL automated sample processor and autoinjector. The samples were manually fortified with internal standard and made basic. The aspec then performed the solid phase extraction and made injections of the samples onto the LC system. Using the automated procedure for analysis, quality control samples for zolpidem (3, 30, and 300 ng/ml) demonstrated acceptable precision with RSD values of 9.0, 4.9, and 5.1%, respectively (n = 12). The method was accurate with all intracurve (n = 4) and overall (n = 12) mean values being less than 10.8% from nominal at all quality control sample concentrations.

Relational Stability of Thyroid Hormones in Euthyroid Subjects and Patients with Autoimmune Thyroid Disease

PubMed Central

Hoermann, Rudolf; Midgley, John E.M.; Larisch, Rolf; Dietrich, Johannes W.

2016-01-01

Background/Aim Operating far from its equilibrium resting point, the thyroid gland requires stimulation via feedback-controlled pituitary thyrotropin (TSH) secretion to maintain adequate hormone supply. We explored and defined variations in the expression of control mechanisms and physiological responses across the euthyroid reference range. Methods We analyzed the relational equilibria between thyroid parameters defining thyroid production and thyroid conversion in a group of 271 thyroid-healthy subjects and 86 untreated patients with thyroid autoimmune disease. Results In the euthyroid controls, the FT3-FT4 (free triiodothyronine-free thyroxine) ratio was strongly associated with the FT4-TSH ratio (tau = −0.22, p < 0.001, even after correcting for spurious correlation), linking T4 to T3 conversion with TSH-standardized T4 production. Using a homeostatic model, we estimated both global deiodinase activity and maximum thyroid capacity. Both parameters were nonlinearly and inversely associated, trending in opposite directions across the euthyroid reference range. Within the panel of controls, the subgroup with a relatively lower thyroid capacity (<2.5 pmol/s) displayed lower FT4 levels, but maintained FT3 at the same concentrations as patients with higher functional and anatomical capacity. The relationships were preserved when extended to the subclinical range in the diseased sample. Conclusion The euthyroid panel does not follow a homogeneous pattern to produce random variation among thyroid hormones and TSH, but forms a heterogeneous group that progressively displays distinctly different levels of homeostatic control across the euthyroid range. This suggests a concept of relational stability with implications for definition of euthyroidism and disease classification. PMID:27843807

Design and evaluation of a new Peltier-cooled laser ablation cell with on-sample temperature control.

PubMed

Konz, Ioana; Fernández, Beatriz; Fernández, M Luisa; Pereiro, Rosario; Sanz-Medel, Alfredo

2014-01-27

A new custom-built Peltier-cooled laser ablation cell is described. The proposed cryogenic cell combines a small internal volume (20 cm(3)) with a unique and reliable on-sample temperature control. The use of a flexible temperature sensor, directly located on the sample surface, ensures a rigorous sample temperature control throughout the entire analysis time and allows instant response to any possible fluctuation. In this way sample integrity and, therefore, reproducibility can be guaranteed during the ablation. The refrigeration of the proposed cryogenic cell combines an internal refrigeration system, controlled by a sensitive thermocouple, with an external refrigeration system. Cooling of the sample is directly carried out by 8 small (1 cm×1 cm) Peltier elements placed in a circular arrangement in the base of the cell. These Peltier elements are located below a copper plate where the sample is placed. Due to the small size of the cooling electronics and their circular allocation it was possible to maintain a peephole under the sample for illumination allowing a much better visualization of the sample, a factor especially important when working with structurally complex tissue sections. The analytical performance of the cryogenic cell was studied using a glass reference material (SRM NIST 612) at room temperature and at -20°C. The proposed cell design shows a reasonable signal washout (signal decay within less than 10 s to background level), high sensitivity and good signal stability (in the range 6.6-11.7%). Furthermore, high precision (0.4-2.6%) and accuracy (0.3-3.9%) in the isotope ratio measurements were also observed operating the cell both at room temperature and at -20°C. Finally, experimental results obtained for the cell application to qualitative elemental imaging of structurally complex tissue samples (e.g. eye sections from a native frozen porcine eye and fresh flower leaves) demonstrate that working in cryogenic conditions is critical in such type of direct sample analysis. Copyright © 2013 Elsevier B.V. All rights reserved.

Comparison of Individual and Pooled Stool Samples for the Assessment of Soil-Transmitted Helminth Infection Intensity and Drug Efficacy

PubMed Central

Mekonnen, Zeleke; Meka, Selima; Ayana, Mio; Bogers, Johannes; Vercruysse, Jozef; Levecke, Bruno

2013-01-01

Background In veterinary parasitology samples are often pooled for a rapid assessment of infection intensity and drug efficacy. Currently, studies evaluating this strategy in large-scale drug administration programs to control human soil-transmitted helminths (STHs; Ascaris lumbricoides, Trichuris trichiura, and hookworm), are absent. Therefore, we developed and evaluated a pooling strategy to assess intensity of STH infections and drug efficacy. Methods/Principal Findings Stool samples from 840 children attending 14 primary schools in Jimma, Ethiopia were pooled (pool sizes of 10, 20, and 60) to evaluate the infection intensity of STHs. In addition, the efficacy of a single dose of mebendazole (500 mg) in terms of fecal egg count reduction (FECR; synonym of egg reduction rate) was evaluated in 600 children from two of these schools. Individual and pooled samples were examined with the McMaster egg counting method. For each of the three STHs, we found a significant positive correlation between mean fecal egg counts (FECs) of individual stool samples and FEC of pooled stool samples, ranging from 0.62 to 0.98. Only for A. lumbricoides was any significant difference in mean FEC of the individual and pooled samples found. For this STH species, pools of 60 samples resulted in significantly higher FECs. FECR for the different number of samples pooled was comparable in all pool sizes, except for hookworm. For this parasite, pools of 10 and 60 samples provided significantly higher FECR results. Conclusion/Significance This study highlights that pooling stool samples holds promise as a strategy for rapidly assessing infection intensity and efficacy of administered drugs in programs to control human STHs. However, further research is required to determine when and how pooling of stool samples can be cost-effectively applied along a control program, and to verify whether this approach is also applicable to other NTDs. PMID:23696905

Prospective, randomized, blinded evaluation of donor semen quality provided by seven commercial sperm banks.

PubMed

Carrell, Douglas T; Cartmill, Deborah; Jones, Kirtly P; Hatasaka, Harry H; Peterson, C Matthew

2002-07-01

To evaluate variability in donor semen quality between seven commercial donor sperm banks, within sperm banks, and between intracervical insemination and intrauterine insemination. Prospective, randomized, blind evaluation of commercially available donor semen samples. An academic andrology laboratory. Seventy-five cryopreserved donor semen samples were evaluated. Samples were coded, then blindly evaluated for semen quality. Standard semen quality parameters, including concentration, motility parameters, World Health Organization criteria morphology, and strict criteria morphology. Significant differences were observed between donor semen banks for most semen quality parameters analyzed in intracervical insemination samples. In general, the greatest variability observed between banks was in percentage progressive sperm motility (range, 8.8 +/- 5.8 to 42.4 +/- 5.5) and normal sperm morphology (strict criteria; range, 10.1 +/- 3.3 to 26.6 +/- 4.7). Coefficients of variation within sperm banks were generally high. These data demonstrate the variability of donor semen quality provided by commercial sperm banks, both between banks and within a given bank. No relationship was observed between the size or type of sperm bank and the degree of variability. The data demonstrate the lack of uniformity in the criteria used to screen potential semen donors and emphasize the need for more stringent screening criteria and strict quality control in processing samples.

Determination of trace metals in spirits by total reflection X-ray fluorescence spectrometry

NASA Astrophysics Data System (ADS)

Siviero, G.; Cinosi, A.; Monticelli, D.; Seralessandri, L.

2018-06-01

Eight spirituous samples were analyzed for trace metal content with Horizon Total Reflection X-Ray Fluorescence (TXRF) Spectrometer. The expected single metal amount is at the ng/g level in a mixed aqueous/organic matrix, thus requiring a sample preparation method capable of achieving suitable limits of detection. On-site enrichment and Atmospheric Pressure-Vapor Phase Decomposition allowed to detect Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Sr and Pb with detection limits ranging from 0.1 ng/g to 4.6 ng/g. These results highlight how the synergy between instrument and sample preparation strategy may foster the use of TXRF as a fast and reliable technique for the determination of trace elements in spirituous samples, either for quality control or risk assessment purposes.

Mimicking Mars: a vacuum simulation chamber for testing environmental instrumentation for Mars exploration.

PubMed

Sobrado, J M; Martín-Soler, J; Martín-Gago, J A

2014-03-01

We have built a Mars environmental simulation chamber, designed to test new electromechanical devices and instruments that could be used in space missions. We have developed this environmental system aiming at validating the meteorological station Rover Environment Monitoring Station of NASA's Mars Science Laboratory mission currently installed on Curiosity rover. The vacuum chamber has been built following a modular configuration and operates at pressures ranging from 1000 to 10(-6) mbars, and it is possible to control the gas composition (the atmosphere) within this pressure range. The device (or sample) under study can be irradiated by an ultraviolet source and its temperature can be controlled in the range from 108 to 423 K. As an important improvement with respect to other simulation chambers, the atmospheric gas into the experimental chamber is cooled at the walls by the use of liquid-nitrogen heat exchangers. This chamber incorporates a dust generation mechanism designed to study Martian-dust deposition while modifying the conditions of temperature, and UV irradiated.

Effects of PV Module Soiling on Glass Surface Resistance and Potential-Induced Degradation: Preprint

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

Hacke, Peter; Burton, Patrick; Hendrickson, Alex

2015-12-03

The sheet resistance of three soil types (Arizona road dust, soot, and sea salt) on glass were measured by the transmission line method as a function of relative humidity (RH) between 39% and 95% at 60 degrees C. Sea salt yielded a 3.5 order of magnitude decrease in resistance on the glass surface when the RH was increased over this RH range. Arizona road dust showed reduced sheet resistance at lower RH, but with less humidity sensitivity over the range tested. The soot sample did not show significant resistivity change compared to the unsoiled control. Photovoltaic modules with sea saltmore » on their faces were step-stressed between 25% and 95% RH at 60 degrees C applying -1000 V bias to the active cell circuit. Leakage current from the cell circuit to ground ranged between two and ten times higher than that of the unsoiled controls. Degradation rate of modules with salt on the surface increased with increasing RH and time.« less

Distribution in the Western United States on Alfalfa and Cultivar Reaction to Mixed Populations of Ditylenchus dipsaci and Aphelenchoides ritzemabosi

PubMed Central

Gray, F. A.; Williams, J. L.; Griffin, G. D.; Wilson, T. E.

1994-01-01

Ditylenchus dipsaci and Aphelenchoides ritzemabosi were extracted from 29 of 40 plant samples (72.5%) collected from Arizona, California, Colorado, Idaho, Montana, Oregon, South Dakota, Utah, Washington, and Wyoming. Percentages of A. ritzemabosi in tissue of the 29 samples ranged from 1.77 to 67.82%. Only Ditylenchus dipsaci was recovered from the remaining 11 samples. All of the 16 fields sampled in Wyoming contained both nematodes. Percentages of A. ritzemabosi in the Wyoming samples ranged from 0.7-30.0%, with an overall mean of 10.3%. Individual plants collected from a field in Big Horn, Wyoming, all contained both nematodes. Percentages of A. ritzemabosi in tissue ranged from 5-70%. Alfalfa stem nematode symptomatic plants in 17 of 18 alfalfa cultivars collected from a screening nursery in California contained both nematodes, of which 10-94% were A. ritzemabosi. Only one cultivar had D. dipsaci only, and no entries had A. ritzemabosi only. Under environmentally controlled conditions, A. ritzemabosi reproduced in all nine alfalfa cultivars tested at 6 weeks of age with a mean reproductive factor (final population/initial population) of 4.1. There were more (P ≤ 0.05) A. ritzemabosi in stem and bud tissue of the susceptible cultivars at harvest than in the resistant cultivars with combined cultivar means of 238, 42, 78, and 4 A. ritzemabosi/g tissue for the susceptible, moderately resistant, resistant, and highly resistant cultivars, respectively. Percentage A. ritzemabosi in tissues decreased over time in seedlings but increased in older plants. PMID:19279952

Statistical validation of reagent lot change in the clinical chemistry laboratory can confer insights on good clinical laboratory practice.

PubMed

Cho, Min-Chul; Kim, So Young; Jeong, Tae-Dong; Lee, Woochang; Chun, Sail; Min, Won-Ki

2014-11-01

Verification of new lot reagent's suitability is necessary to ensure that results for patients' samples are consistent before and after reagent lot changes. A typical procedure is to measure results of some patients' samples along with quality control (QC) materials. In this study, the results of patients' samples and QC materials in reagent lot changes were analysed. In addition, the opinion regarding QC target range adjustment along with reagent lot changes was proposed. Patients' sample and QC material results of 360 reagent lot change events involving 61 analytes and eight instrument platforms were analysed. The between-lot differences for the patients' samples (ΔP) and the QC materials (ΔQC) were tested by Mann-Whitney U tests. The size of the between-lot differences in the QC data was calculated as multiples of standard deviation (SD). The ΔP and ΔQC values only differed significantly in 7.8% of the reagent lot change events. This frequency was not affected by the assay principle or the QC material source. One SD was proposed for the cutoff for maintaining pre-existing target range after reagent lot change. While non-commutable QC material results were infrequent in the present study, our data confirmed that QC materials have limited usefulness when assessing new reagent lots. Also a 1 SD standard for establishing a new QC target range after reagent lot change event was proposed. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

Utilization of chitosan as an antimicrobial agent for pasteurized palm sap (Borassus flabellifer Linn.) during storage.

PubMed

Naknean, Phisut; Jutasukosol, Keawta; Mankit, Theerarat

2015-02-01

The objective of this research was to assess the potential of chitosan for improvement the quality of pasteurized palm sap during storage. First, the effect of chitosan content on sensory attributes was investigated to select suitable concentration of chitosan for further study. Fresh palm sap was enriched with chitosan at various concentrations (0-2 g/L) and pasteurized at 80 °C for 10 min, consequently evaluated by consumers. It was found that samples added chitosan in the range of 0-1.00 g/L were considered acceptable. Thus, the addition chitosan in the concentration of 0-1.00 g/L was chosen for further study. The sample without chitosan addition was used as a control sample. Each selected sample was determined for their qualities during storage at 1 week interval. It was found that lightness and transmittance values of all samples tended to increase during storage. Lower PPO and invertase activity were observed in all chitosan-treated samples compared to control sample. Chitosan could minimize the loss of sucrose and the increase in glucose and fructose content during storage. In addition, an increase in chitosan concentration resulted in the increase in DPPH radical scavenging activity. Furthermore, the addition of chitosan could retard the development of microorganism during storage as demonstrated by lower microbial loads compared to control sample. It can be concluded that a combination of pasteurization with chitosan addition (0.50 g/L) and low temperature storage could preserve palm sap for approximately 6 weeks. Thus, the incorporation of chitosan in palm sap could be used as an alternative way to extend shelf life of pasteurized palm sap.

Scheduling whole-air samples above the Trade Wind Inversion from SUAS using real-time sensors

NASA Astrophysics Data System (ADS)

Freer, J. E.; Greatwood, C.; Thomas, R.; Richardson, T.; Brownlow, R.; Lowry, D.; MacKenzie, A. R.; Nisbet, E. G.

2015-12-01

Small Unmanned Air Systems (SUAS) are increasingly being used in science applications for a range of applications. Here we explore their use to schedule the sampling of air masses up to 2.5km above ground using computer controlled bespoked Octocopter platforms. Whole-air sampling is targeted above, within and below the Trade Wind Inversion (TWI). On-board sensors profiled the TWI characteristics in real time on ascent and, hence, guided the altitudes at which samples were taken on descent. The science driver for this research is investigation of the Southern Methane Anomaly and, more broadly, the hemispheric-scale transport of long-lived atmospheric tracers in the remote troposphere. Here we focus on the practical application of SUAS for this purpose. Highlighting the need for mission planning, computer control, onboard sensors and logistics in deploying such technologies for out of line-of-sight applications. We show how such a platform can be deployed successfully, resulting in some 60 sampling flights within a 10 day period. Challenges remain regarding the deployment of such platforms routinely and cost-effectively, particularly regarding training and support. We present some initial results from the methane sampling and its implication for exploring and understanding the Southern Methane Anomaly.

Monitoring lipase/esterase activity by stopped flow in a sequential injection analysis system using p-nitrophenyl butyrate.

PubMed

Pliego, Jorge; Mateos, Juan Carlos; Rodriguez, Jorge; Valero, Francisco; Baeza, Mireia; Femat, Ricardo; Camacho, Rosa; Sandoval, Georgina; Herrera-López, Enrique J

2015-01-27

Lipases and esterases are biocatalysts used at the laboratory and industrial level. To obtain the maximum yield in a bioprocess, it is important to measure key variables, such as enzymatic activity. The conventional method for monitoring hydrolytic activity is to take out a sample from the bioreactor to be analyzed off-line at the laboratory. The disadvantage of this approach is the long time required to recover the information from the process, hindering the possibility to develop control systems. New strategies to monitor lipase/esterase activity are necessary. In this context and in the first approach, we proposed a lab-made sequential injection analysis system to analyze off-line samples from shake flasks. Lipase/esterase activity was determined using p-nitrophenyl butyrate as the substrate. The sequential injection analysis allowed us to measure the hydrolytic activity from a sample without dilution in a linear range from 0.05-1.60 U/mL, with the capability to reach sample dilutions up to 1000 times, a sampling frequency of five samples/h, with a kinetic reaction of 5 min and a relative standard deviation of 8.75%. The results are promising to monitor lipase/esterase activity in real time, in which optimization and control strategies can be designed.

Monitoring Lipase/Esterase Activity by Stopped Flow in a Sequential Injection Analysis System Using p-Nitrophenyl Butyrate

PubMed Central

Pliego, Jorge; Mateos, Juan Carlos; Rodriguez, Jorge; Valero, Francisco; Baeza, Mireia; Femat, Ricardo; Camacho, Rosa; Sandoval, Georgina; Herrera-López, Enrique J.

2015-01-01

Lipases and esterases are biocatalysts used at the laboratory and industrial level. To obtain the maximum yield in a bioprocess, it is important to measure key variables, such as enzymatic activity. The conventional method for monitoring hydrolytic activity is to take out a sample from the bioreactor to be analyzed off-line at the laboratory. The disadvantage of this approach is the long time required to recover the information from the process, hindering the possibility to develop control systems. New strategies to monitor lipase/esterase activity are necessary. In this context and in the first approach, we proposed a lab-made sequential injection analysis system to analyze off-line samples from shake flasks. Lipase/esterase activity was determined using p-nitrophenyl butyrate as the substrate. The sequential injection analysis allowed us to measure the hydrolytic activity from a sample without dilution in a linear range from 0.05–1.60 U/mL, with the capability to reach sample dilutions up to 1000 times, a sampling frequency of five samples/h, with a kinetic reaction of 5 min and a relative standard deviation of 8.75%. The results are promising to monitor lipase/esterase activity in real time, in which optimization and control strategies can be designed. PMID:25633600

Quantitative 31P NMR for Simultaneous Trace Analysis of Organophosphorus Pesticides in Aqueous Media Using the Stir Bar Sorptive Extraction Method

NASA Astrophysics Data System (ADS)

Ansari, S.; Talebpour, Z.; Molaabasi, F.; Bijanzadeh, H. R.; Khazaeli, S.

2016-09-01

The analysis of pesticides in water samples is of primary concern for quality control laboratories due to the toxicity of these compounds and their associated public health risk. A novel analytical method based on stir bar sorptive extraction (SBSE), followed by 31P quantitative nuclear magnetic resonance (31P QNMR), has been developed for simultaneously monitoring and determining four organophosphorus pesticides (OPPs) in aqueous media. The effects of factors on the extraction efficiency of OPPs were investigated using a Draper-Lin small composite design. An optimal sample volume of 4.2 mL, extraction time of 96 min, extraction temperature of 42°C, and desorption time of 11 min were obtained. The results showed reasonable linearity ranges for all pesticides with correlation coefficients greater than 0.9920. The limit of quantification (LOQ) ranged from 0.1 to 2.60 mg/L, and the recoveries of spiked river water samples were from 82 to 94% with relative standard deviation (RSD) values less than 4%. The results show that this method is simple, selective, rapid, and can be applied to other sample matrices.

CASTNet Air Toxics Monitoring Program (CATMP): VOC and carbonyl data for July, 1993 through March, 1994

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

Harlos, D.P.; Edgerton, E.S.

1994-12-31

The US EPA has, under the auspices of the CASTNet program (Clean Air Status and Trends Network), initiated the CASTNet Air Toxics Monitoring Program (CATMP). Volatile Organic Compounds (VOC) and carbonyls and metals are sampled for 24-hour periods on a 12-day schedule using TO-14 samplers (SUMMA canisters) and dinitrophenylhydrazine-coated (dmph) sorbent cartridges and high volume particle samplers. Sampling was begun at most sites in July of 1993. The sites are operated by state and local air pollution control programs and all analysis is performed by Environmental Science and Engineering (ESE) in Gainesville, Florida. The network currently supports 15 VOC sites,more » of which 7 also sample carbonyls. Three sites sample metals only in Pinellas County, Florida. The limits of detection of 0.05 ppb for VOCs allow routine tracking of a wide range of pollutants including several greenhouse gases, transportation pollutants and photochemically-derived compounds. The sites range from major urban areas (Chicago, St. Louis) to a rural village (Waterbury, Vermont). Results of the first three quarters of VOC and carbonyl data collection are summarized in this presentation.« less

A genetic survey of Salvinia minima in the southern United States

USGS Publications Warehouse

Madeira, Paul T.; Jacono, C.C.; Tipping, Phil; Van, Thai K.; Center, Ted D.

2003-01-01

The genetic relationships among 68 samples of Salvinia minima (Salviniaceae) were investigated using RAPD analysis. Neighbor joining, principle components, and AMOVA analyses were used to detect differences among geographically referenced samples within and outside of Florida. Genetic distances (Nei and Li) range up to 0.48, although most are under 0.30, still relatively high levels for an introduced, clonally reproducing plant. Despite the diversity AMOVA analysis yielded no indication that the Florida plants, as a group, were significantly different from the plants sampled elsewhere in its adventive, North American range. A single, genetically dissimilar population probably exists in the recent (1998) horticultural introduction to Mississippi. When the samples were grouped into 10 regional (but artificial) units and analyzed using AMOVA the between region variance was only 7.7%. Genetic similarity among these regions may indicate introduction and dispersal from common sources. The reduced aggressiveness of Florida populations (compared to other states) may be due to herbivory. The weevil Cyrtobagous salviniae, a selective feeder, is found in Florida but not other states. The genetic similarity also suggests that there are no obvious genetic obstacles to the establishment or efficacy of C. salviniae as a biological control agent on S. minima outside of Florida.

EFFECT OF VISIBLE RANGE ELECTROMAGNETIC RADIATIONS ON ESCHERICHIA COLI.

PubMed

Azeemi, Samina T Yousuf; Shaukat, Saleem Farooq; Azeemi, Khawaja Shamsuddin; Khan, Idrees; Mahmood, Khalid; Naz, Farah

2017-01-01

Escherichia coli is the agent responsible for a range of clinical diseases. With emerging antimicrobial resistance, other treatment options including solar/photo-therapy are becoming increasingly common. Visible Range Radiation Therapy/Colour Therapy is an emerging technique in the field of energy/vibrational medicine that uses visible spectrum of Electromagnetic Radiations to cure different diseases. In this study, our goal was to understand the effect of Visible Range Electromagnetic Radiations on E. coli (in vitro) and therefore find out the most appropriate visible range radiation for the treatment of diseases caused by E. coli. A total of 6 non-repetitive E. coli isolates were obtained from urine samples obtained from hospitalized patients with UTI. Single colony of E. coli was inoculated in 3 ml of Lysogeny Broth (LB) and 40 μl of this E. coli suspension was poured into each of the plastic tubes which were then irradiated with six different wavelengths in the visible region (Table. 1) after 18 hours with one acting as a control. The Optical Densities of these irradiated samples were then measured. Furthermore, scanning electron microscopy (TEFCAN ZEGA3) was carried out. The analysis of the microscopic and SEM images of irradiated E. coli samples with six different visible range radiations is representative of The fact that E. coli responded differently to every applied radiation in the visible region and the most profound inhibitory effects were that of 538nm Visible Range Radiation (Green) which proved to be bactericidal and 590nm Visible Range Radiation (yellow) which was bacteriostatic. The enhanced growth of E. coli with varying degrees was clearly observed in 610nm (orange), 644nm (red), 464nm (Purple) and 453nm (blue). It can be concluded that 538nm (Green) and 590nm (Yellow) can effectively be used for treating E. coli borne diseases.

EFFECT OF VISIBLE RANGE ELECTROMAGNETIC RADIATIONS ON ESCHERICHIA COLI

PubMed Central

Azeemi, Samina T. Yousuf; Shaukat, Saleem Farooq; Azeemi, Khawaja Shamsuddin; Khan, Idrees; Mahmood, Khalid; Naz, Farah

2017-01-01

Background: Escherichia coli is the agent responsible for a range of clinical diseases. With emerging antimicrobial resistance, other treatment options including solar/photo-therapy are becoming increasingly common. Visible Range Radiation Therapy/Colour Therapy is an emerging technique in the field of energy/vibrational medicine that uses visible spectrum of Electromagnetic Radiations to cure different diseases. In this study, our goal was to understand the effect of Visible Range Electromagnetic Radiations on E. coli (in vitro) and therefore find out the most appropriate visible range radiation for the treatment of diseases caused by E. coli. Materials and Methods: A total of 6 non-repetitive E. coli isolates were obtained from urine samples obtained from hospitalized patients with UTI. Single colony of E. coli was inoculated in 3 ml of Lysogeny Broth (LB) and 40 μl of this E. coli suspension was poured into each of the plastic tubes which were then irradiated with six different wavelengths in the visible region (Table. 1) after 18 hours with one acting as a control. The Optical Densities of these irradiated samples were then measured. Furthermore, scanning electron microscopy (TEFCAN ZEGA3) was carried out. Results: The analysis of the microscopic and SEM images of irradiated E. coli samples with six different visible range radiations is representative of The fact that E. coli responded differently to every applied radiation in the visible region and the most profound inhibitory effects were that of 538nm Visible Range Radiation (Green) which proved to be bactericidal and 590nm Visible Range Radiation (yellow) which was bacteriostatic. The enhanced growth of E. coli with varying degrees was clearly observed in 610nm (orange), 644nm (red), 464nm (Purple) and 453nm (blue). Conclusion: It can be concluded that 538nm (Green) and 590nm (Yellow) can effectively be used for treating E. coli borne diseases. PMID:28331912

Stable Isotopic Constraints on the Geographic Sources of Marijuana in Alaska

NASA Astrophysics Data System (ADS)

Booth, A. L.; Wooller, M. J.; Haubenstock, N. A.; Howe, T. A.

2007-12-01

Marijuana in Alaska can have numerous sources. Confiscated plants are known to originate either from within the state (e.g., Fairbanks and the Matanuska-Susitna Valley) or from numerous areas outside the state (e.g., Latin America, Canada and the contiguous United States). Latin America reportedly supplies a large percentage of the marijuana currently distributed in the lower 48 states of the U.S.A. However, in more remote areas of the country such as Fairbanks, Alaska, the supply proportions from different geographic areas are not well known. This is due to an insufficient ability to trace source regions from which confiscated marijuana was originally grown. As such, we have analyzed multiple stable isotopes (C, N, O and H) preserved in marijuana samples to identify the likely geographic source from which the marijuana originated (Drug Enforcement Agency license # RW0324551). These samples were confiscated in Fairbanks, Alaska and supplied to us by the University of Alaska Fairbanks (UAF) Police Department. Among 36 marijuana plant samples, we found an unexpectedly large range in the stable carbon isotope compositions (‰13C = -62.2‰ to -24.4‰), with twelve of the 36 samples exhibiting exceedingly low δ13C (-36.1‰ to -62.2‰) relative to typical δ13C of other C3 plants. Interior growing conditions (e.g., hydroponics and/or greenhouses) and a variety of CO2 sources (e.g., CO2 from tanks and fermentation CO2 generators) frequently supplied to growing marijuana to improve yields may account for these exceptionally low δ13C values. Stable oxygen and hydrogen isotope compositions (δ18O and δD vs. V-SMOW) of the marijuana samples were found to range from 10.0‰ to 27.6‰ and -197.1‰ to -134.9‰ respectively. The large range of values suggests that the samples originated from multiple sources ranging from low to high latitudes. δ15N of the marijuana samples also exhibited a large range (-7.0‰ to 14.8‰). This project has implications for the improvement of forensic technology in relatively remote areas such as Alaska. Officers for the Alaska Bureau of Drug and Alcohol Enforcement spend a significant amount of time controlling the production and distribution of marijuana, while the resources allocated for law enforcement must be utilized over a wide geographic area.

Biosensor for on-line fluorescent detection of trifluoroperazine based on genetically modified calmodulin.

PubMed

González-Andrade, Martin; Benito-Peña, Elena; Mata, Rachel; Moreno-Bondi, Maria C

2012-04-01

This paper describes the development of a novel on-line biosensor based on a fluorescently labeled human calmodulin (CaM), hCaM M124C-mBBr, immobilized on controlled-pore glass (CPG), for the analysis of trifluoroperazine (TFP); a phenothiazine drug in human urine samples. The device was automated by packing hCaM M124C-mBBr-CPG in a continuous-flow microcell connected to a monitoring system, composed of a bifurcated optical fiber coupled to a spectrofluorometer. Operating parameters of the on-line biosensor (flow rate, sample injection volume, and carrier solution and buffer pH) were studied and optimized. Under the optimal conditions, the biosensor provides a detection and a quantification limit of 0.24 and 0.52 μg mL(-1), respectively, and a dynamic range from 0.52 to 61.05 μg mL(-1) TFP (n = 5, correlation coefficient 0.998). The response time (t(100)) was shorter than 42 s (recovery time <4.5 min) and reproducibility and repeatability of the TFP measurements, within the linear response range, were lower than 1.4 and 2.7%, respectively. The device was successfully applied to the analysis of TFP in spiked human urine samples with recoveries ranging between 97 and 101% and with RSDs lower than 5.9%.

A high-resolution superconducting pressure control system for use at low temperatures

NASA Astrophysics Data System (ADS)

Geng, Z. K.; Swanson, D. R.; Nissen, J. A.; Lipa, J. A.

2000-01-01

We have developed a high resolution superconducting pressure gauge and controller system capable of stabilizing pressure to within +/-10-8 bar in the range 0-30 bars at temperatures below about 6K. The system consists of two parts: a transducer and a pressure actuator. The transducer is based on the inductive sensing of the position of a diaphragm using superconducting techniques. A rod attached to the center of the diaphragm supports a superconducting plate which is in close proximity to a flat, spiral superconducting coil. A persistent current of about 1 A is trapped in the coil and is coupled to a dc SQUID magnetometer. The magnetometer produces a partially digitized dc output proportional to the change of pressure applied to the diaphragm. Because of the ability of the magnetometer to count magnetic flux quanta, an extremely wide dynamic range can be achieved with high sensitivity and repeatability. The transducer was used to control the pressure of a sample of liquid helium at temperatures near 2 K and pressures from 1-25 bars. The actuator consisted of two parts: a thermally isolated chamber filled with 3He that could be heated and cooled as desired over the range 1.5 to 10 K, and a beryllium-copper diaphragm assembly. This diaphragm had the 3He on one side and the sample helium on the other. A simple servomechanism was used to convert the output signal from the magnetometer to heat applied to the 3He chamber. The system has been operated routinely over the full range of pressures and so far no significant drift has been detected. It is somewhat sensitive to vibration and EMI, but otherwise appears quite robust. Plans have been made to improve the shielding to reduce the EMI susceptibility. The vibration sensitivity can be reduced by making use of a pair of pressure sensing diaphragms acting in opposite directions. .

Effect of growth promotants on the occurrence of endogenous and synthetic steroid hormones on feedlot soils and in runoff from beef cattle feeding operations.

PubMed

Bartelt-Hunt, Shannon L; Snow, Daniel D; Kranz, William L; Mader, Terry L; Shapiro, Charles A; Donk, Simon J van; Shelton, David P; Tarkalson, David D; Zhang, Tian C

2012-02-07

Supplements and growth promotants containing steroid hormones are routinely administered to beef cattle to improve feeding efficiency, reduce behavioral problems, and enhance production. As a result, beef cattle manure will contain both synthetic steroids as well as a range of endogenous steroids including androgens, estrogens, and progestogens. A two-year controlled study was conducted in which beef cattle were administered steroid hormones via subcutaneous implants and feed additives and the occurrence of 16 endogenous and synthetic steroid hormones and metabolites was evaluated in runoff from beef cattle feedlots and in manure and soil collected from feedlot surfaces. Samples were extracted and analyzed using liquid chromatography tandem mass spectrometryfor metabolites of the synthetic androgen trenbolone acetate, 17α-trenbolone, 17β-trenbolone, for the nonsteroidal semisynthetic estrogen agonist, α-zearalanol, and the synthetic progesterone melengesterol acetate, as well as a wide range of endogeneous estrogens, androgens, and fusarium metabolites. Synthetic steroids including trenbolone metabolites and melengestrol acetate were detected in fresh manure and in feedlot surface soils from cattle administered synthetic steroids at concentrations up to 55 ± 22 ng/g dry weight (dw) (17α-trenbolone) and 6.5 ± 0.4 ng/g dw (melengesterol acetate). Melengesterol acetate was detected in 6% of runoff samples from feedlots holding cattle administered synthetic steroids at concentrations ranging up to 115 ng/L. The presence of melengesterol acetate in runoff from beef cattle feeding operations has not been previously reported. Synthetic steroids were not detected in manure or runoff from control cattle. A wide range of endogenous hormones were detected in runoff and feedlot surface soils and manure from cattle given synthetic steroids and from control cattle, with no statistically significant differences in concentration. These results indicate that runoff from confined animal production facilities is of environmental and public health concern regardless of the use of growth promotants.

A systematic review of the efficacy of venlafaxine for the treatment of fibromyalgia.

PubMed

VanderWeide, L A; Smith, S M; Trinkley, K E

2015-02-01

Fibromyalgia is a painful disease affecting 1-2% of the United States population. Serotonin and norepinephrine reuptake inhibitors (SNRIs), such as duloxetine and milnacipran, are well studied and frequently used for treating this disorder. However, efficacy data are limited for the SNRI venlafaxine despite its use in nearly a quarter of patients with fibromyalgia. Accordingly, we systematically reviewed the efficacy of venlafaxine for treatment of fibromyalgia. PubMed, Web of Science and the Cochrane Database were searched using the terms 'venlafaxine' and 'fibromyalgia'. Results were classified as primary studies or review articles based on abstract review. References of review articles were evaluated to ensure no primary studies evaluating venlafaxine were overlooked. All clinical studies that investigated venlafaxine for the treatment of fibromyalgia were included and graded on strength of evidence. Five studies met the inclusion criteria, including 4 open-label cohort studies and 1 randomized, controlled trial. Study durations ranged from 6 weeks to 6 months, and study sizes ranged from 11 to 102 participants. Four of the five published studies reported improvement in at least one outcome. Generally consistent improvements were observed in pain-related outcome measures, including the Fibromyalgia Impact Questionnaire (range, 26-29% reduction; n = 2 studies), Visual Analog Scale (range, 36-45% reduction; n = 2 studies), McGill Pain Questionnaire (48% reduction; n = 1 study) and Clinical Global Impression scale (51% had significant score change; n = 1 study). However, the few studies identified were limited by small sample size, inconsistent use of outcomes and methodological concerns. Studies assessing the efficacy of venlafaxine in the treatment of fibromyalgia to date have been limited by small sample size, inconsistent venlafaxine dosing, lack of placebo control and lack of blinding. In the context of these limitations, venlafaxine appears to be at least modestly effective in treating fibromyalgia. Larger randomized controlled trials are needed to further elucidate the full benefit of venlafaxine. © 2014 John Wiley & Sons Ltd.

Assessment of Air Quality in the International Space Station (ISS) and Space Shuttle Based on Samples Returned Aboard STS-110 (ISS-8A) in April 2002

NASA Technical Reports Server (NTRS)

James, John T.

2002-01-01

The toxicological assessment of grab sample canisters (GSCs) returned aboard STS-110 is reported. Analytical methods have not changed from earlier reports, and surrogate standard recoveries from the GSCs were 77-121%, with one exception. Pressure tracking indicated no leaks in the canisters. Recoveries from lab and trip controls for formaldehyde analyses ranged from 87 to 96%. The two general criteria used to assess air quality are the total-non-methane-volatile organic hydrocarbons (NMVOCs) and the total T-value (minus the CO2 and formaldehyde contributions). Because of the inertness of Freon 218 (octafluoropropane, OFP), its contribution to the NMVOC is subtracted and tabulated separately. Control of atmospheric alcohols is important to the water recovery system engineers, hence total alcohols are also shown for each sample. Because formaldehyde is quantified from sorbent badges, its concentration is listed separately. These five indices of air quality are summarized.

Undecompressed microbial populations from the deep sea.

PubMed Central

Jannasch, H J; Wirsen, C O; Taylor, C D

1976-01-01

Metabolic transformations of glutamate and Casamino Acids by natural microbial populations collected from deep waters (1,600 to 3,100 m) were studied in decompressed and undecompressed samples. Pressure-retaining sampling/incubation vessels and appropriate subsampling/incubation vessels and appropriate subsampling techniques permitted time course experiments. In all cases the metabolic activity in undecompressed samples was lower than it was when incubated at 1 atm. Surface water controls showed a reduced activity upon compression. The processes involving substrate incorporation into cell material were more pressure sensitive than was respiration. The low utilization of substrates, previously found by in situ incubations for up to 12 months, was confirmed and demonstrated to consist of an initial phase of activity, in the range of 5 to 60 times lower than the controls, followed by a stationary phase of virtually no substrate utilization. No barophilic growth response (higher rates at elevated pressure than at 1 atm) was recorded; all populations observed exhibition various degrees of barotolerance. Images PMID:791117

Contamination control approach for the Extreme Ultraviolet Explorer satellite instrumentation

NASA Technical Reports Server (NTRS)

Mrowka, Stan; Jelinsky, Sharon; Jelinsky, Patrick; Malina, Roger F.

1987-01-01

The Extreme Ultraviolet Explorer will perform an all-sky survey and spectroscopic observations over the wavelength range 80-900A. Hydrocarbon and particulate contamination will potentially affect the throughput and signal to noise ratio of the signal detected by the instruments. A witness sample program is here used to investigate and monitor the effects of specific contaminants on EUV reflectivity. Witness samples were intentionally contaminated with thin layers of pump oil. An oil layer 150 A thick was applied and found to evaporate over 8 hours. The EUV reflectivity and imaging properties were then measured and found to be acceptable for grazing angles between 5 and 30 deg. In a second test, layers 500 A thick were deposited and then allowed to evaporate in vacuum; once the oil had evaporated to at least 350 A, the final sample reflectivity was degraded less than 10 percent, but the image was degraded severely by scattering. An outline of the contamination control program is also presented.

Use of virtual reality intervention to improve reaction time in children with cerebral palsy: A randomized controlled trial.

PubMed

Pourazar, Morteza; Mirakhori, Fatemeh; Hemayattalab, Rasool; Bagherzadeh, Fazlolah

2017-09-21

The purpose of this study was to investigate the training effects of Virtual Reality (VR) intervention program on reaction time in children with cerebral palsy. Thirty boys ranging from 7 to 12 years (mean = 11.20; SD = .76) were selected by available sampling method and randomly divided into the experimental and control groups. Simple Reaction Time (SRT) and Discriminative Reaction Time (DRT) were measured at baseline and 1 day after completion of VR intervention. Multivariate analysis of variance (MANOVA) and paired sample t-test were performed to analyze the results. MANOVA test revealed significant effects for group in posttest phase, with lower reaction time in both measures for the experimental group. Based on paired sample t-test results, both RT measures significantly improved in experimental group following the VR intervention program. This paper proposes VR as a promising tool into the rehabilitation process for improving reaction time in children with cerebral palsy.

A Controlled Study of Mercury Levels in Hair Samples of Children with Autism as Compared to Their Typically Developing Siblings

ERIC Educational Resources Information Center

Williams, P. Gail; Hersh, Joseph H.; Allard, AnnaMary; Sears, Lonnie L.

2008-01-01

Autism is a developmental disability characterized by severe, pervasive deficits in social interaction, communication and range of interests and activities. The neurobiologic basis of autism is well accepted, although the specific etiology is unknown. It has been theorized that autism may result from a combination of predisposing genes and…

The Use of Native Speaker Norms in Critical Period Hypothesis Research

ERIC Educational Resources Information Center

Andringa, Sible

2014-01-01

In critical period hypothesis (CPH) research, native speaker (NS) norm groups have often been used to determine whether nonnative speakers (NNSs) were able to score within the NS range of scores. One goal of this article is to investigate what NS samples were used in previous CPH research. The literature review shows that NS control groups tend to…

Effects of Training Method and Gender on Learning 2D/3D Geometry

ERIC Educational Resources Information Center

Khairulanuar, Samsudin; Nazre, Abd Rashid; Jamilah, H.; Sairabanu, Omar Khan; Norasikin, Fabil

2010-01-01

This article reports the findings of an experimental study involving 36 primary school students (16 girls, 20 boys, Mean age = 9.5 years, age range: 8-10 years) in geometrical understanding of 2D and 3D objects. Students were assigned into two experimental groups and one control group based on a stratified random sampling procedure. The first…

Randomized Controlled Trial of a Brief Intervention for Increasing Participation in Parent Management Training

ERIC Educational Resources Information Center

Nock, Matthew K.; Kazdin, Alan E.

2005-01-01

Evidence-based treatments exist for a range of child and adolescent behavior problems; however, effects are often limited by poor treatment attendance and adherence. The authors developed and evaluated the efficacy of a brief (5 to 45 min) intervention designed to increase treatment attendance and adherence in a sample of 76 parents referred for…

Assessment of the quality of simvastatin capsules from compounding pharmacies.

PubMed

Markman, Blanca Elena Ortega; Rosa, Paulo César Pires; Koschtschak, Maria Regina Walter

2010-12-01

To validate a method for determining the simvastatin content of compounded capsules, using high performance liquid chromatography. Eighteen samples of simvastatin 40 mg capsules from compounding pharmacies in the cities of São Paulo, Guarulhos, São Bernardo do Campo and Campinas, Southeastern Brazil, prescribed for fictitious patients were assessed. The analyses were based on the Brazilian Pharmacopoeia and on the high performance liquid chromatography method, optimized and validated in accordance with national and international standards for identification and quantification tests on compounded capsules. The mean weight of the capsules ranged from 70 mg to 316 mg; four samples presented weight variation outside of the specification. The simvastatin content in the capsules was within the specification in 11 samples. In six, the content ranged from 4% to 87% of the declared quantity, thereby not complying with the content requirements for the active agent. For one sample, no content or uniformity determinations were performed. In the content uniformity test, 15 samples presented indices of less than 85%, with relative standard deviations greater than 6%. Three pharmacies had met the specification in this test. In the dissolution test, eight samples presented unsatisfactory results in the first stage of the test, while the remainder presented inconclusive results. The method used was shown to be suitable for application to quality control, and it revealed the poor quality of the simvastatin capsules produced by some compounding pharmacies.

Critical current measurements of high-temperature superconducting short samples at a wide range of temperatures and magnetic fields.

PubMed

Ma, Hongjun; Liu, Huajun; Liu, Fang; Zhang, Huahui; Ci, Lu; Shi, Yi; Lei, Lei

2018-01-01

High-Temperature Superconductors (HTS) are potential materials for high-field magnets, low-loss transmission cables, and Superconducting Magnetic Energy Storage (SMES) due to their high upper critical magnetic field (H c2 ) and critical temperature (T c ). The critical current (I c ) of HTS, which is one of the most important parameters for superconductor application, depends strongly on the magnetic fields and temperatures. A new I c measurement system that can carry out accurate I c measurement for HTS short samples with various temperatures (4.2-80 K), magnetic fields (0-14 T), and angles of the magnetic field (0°-90°) has been developed. The I c measurement system mainly consists of a measurement holder, temperature-control system, background magnet, test cryostat, data acquisition system, and DC power supply. The accuracy of temperature control is better than ±0.1 K over the 20-80 K range and ±0.05 K when measured below 20 K. The maximum current is over 1000 A with a measurement uncertainty of 1%. The system had been successfully used for YBa 2 Cu 3 O 7-x (YBCO) tapes I c determination with different temperatures and magnetic fields.

Bipolar vulnerability and extreme appraisals of internal states: a computerized ratings study.

PubMed

Dodd, Alyson L; Mansell, Warren; Morrison, Anthony P; Tai, Sara

2011-01-01

A recent integrative cognitive model proposed that multiple, extreme, personalized, positive and negative appraisals of internal states predispose to maintain and exacerbate bipolar symptoms. This study aimed to directly assess conviction in a range of positive and negative appraisals of internal states suggested by the model, by using a laboratory-based computerized task. In a student sample (n = 68), a history of hypomania was associated with more positive and less negative appraisals of internal states, and a history of depression was associated with more negative appraisals and less positive appraisals of internal states. The sample was then split into three groups for comparison: bipolar risk (n = 18), depression risk (n = 20) and controls (n  = 30). Relative to controls, the bipolar risk group made more extreme ratings of catastrophic appraisals of low activation states and tended to make more extreme ratings of appraisals of high activation states. The depression risk group scored higher on a range of negative appraisals of low activation states. These findings provide tentative support for the role of both positive and negative, extreme, personalized appraisals of internal states in hypomania and depression. Copyright © 2011 John Wiley & Sons, Ltd.

Critical current measurements of high-temperature superconducting short samples at a wide range of temperatures and magnetic fields

NASA Astrophysics Data System (ADS)

Ma, Hongjun; Liu, Huajun; Liu, Fang; Zhang, Huahui; Ci, Lu; Shi, Yi; Lei, Lei

2018-01-01

High-Temperature Superconductors (HTS) are potential materials for high-field magnets, low-loss transmission cables, and Superconducting Magnetic Energy Storage (SMES) due to their high upper critical magnetic field (Hc2) and critical temperature (Tc). The critical current (Ic) of HTS, which is one of the most important parameters for superconductor application, depends strongly on the magnetic fields and temperatures. A new Ic measurement system that can carry out accurate Ic measurement for HTS short samples with various temperatures (4.2-80 K), magnetic fields (0-14 T), and angles of the magnetic field (0°-90°) has been developed. The Ic measurement system mainly consists of a measurement holder, temperature-control system, background magnet, test cryostat, data acquisition system, and DC power supply. The accuracy of temperature control is better than ±0.1 K over the 20-80 K range and ±0.05 K when measured below 20 K. The maximum current is over 1000 A with a measurement uncertainty of 1%. The system had been successfully used for YBa2Cu3O7-x(YBCO) tapes Ic determination with different temperatures and magnetic fields.

An approximate, maximum terminal velocity descent to a point

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

Eisler, G.R.; Hull, D.G.

1987-01-01

No closed form control solution exists for maximizing the terminal velocity of a hypersonic glider at an arbitrary point. As an alternative, this study uses neighboring extremal theory to provide a sampled data feedback law to guide the vehicle to a constrained ground range and altitude. The guidance algorithm is divided into two parts: 1) computation of a nominal, approximate, maximum terminal velocity trajectory to a constrained final altitude and computation of the resulting unconstrained groundrange, and 2) computation of the neighboring extremal control perturbation at the sample value of flight path angle to compensate for changes in the approximatemore » physical model and enable the vehicle to reach the on-board computed groundrange. The trajectories are characterized by glide and dive flight to the target to minimize the time spent in the denser parts of the atmosphere. The proposed on-line scheme successfully brings the final altitude and range constraints together, as well as compensates for differences in flight model, atmosphere, and aerodynamics at the expense of guidance update computation time. Comparison with an independent, parameter optimization solution for the terminal velocity is excellent. 6 refs., 3 figs.« less

Development and Validation of a Rotor-Gene Real-Time PCR Assay for Detection, Identification, and Quantification of Chlamydia trachomatis in a Single Reaction

PubMed Central

Jalal, Hamid; Stephen, Hannah; Curran, Martin D.; Burton, Janet; Bradley, Michelle; Carne, Christopher

2006-01-01

A multitarget real-time PCR (MRT-PCR) for detection of Chlamydia trachomatis DNA was developed and validated. There were three targets for amplification in a single reaction: the cryptic plasmid (CP), the major outer membrane protein (MOMP) gene, and an internal control. The assay had the following characteristics: (i) detection and confirmation of the presence of C. trachomatis DNA in a single reaction, (ii) detection of all genovars of C. trachomatis without any cross-reactivity with pathogenic bacteria or commensal organisms of the oropharynx and genital tract, (iii) a 95% probability of detection with three copies of MOMP and one copy of CP per reaction mixture, (iv) identification of the inhibition of amplification, (v) a quantitative dynamic range of 25 to 250,000 genome copies per reaction mixture, (vi) high intra- and interassay reproducibilities, and (vii) correct identification of all samples in the validation panel. There were 146 COBAS Amplicor PCR (Amplicor PCR)-positive samples and 122 Amplicor PCR-negative samples in the panel. MRT-PCR detected CP DNA alone in 6 (4%) Amplicor PCR-positive samples and both CP and MOMP DNAs in 140 (96%) of 146 Amplicor PCR-positive samples. The quantity of MOMP DNA in 95 (68%) of 140 samples was within the dynamic range of the assay. The median C. trachomatis load in these samples was 321 genome copies per reaction mixture (range, 26 to 40,137 genome copies per reaction mixture). Due to the inclusion of two different C. trachomatis-specific targets, the assay confirmed 259 (97%) of 268 results in a single reaction. This assay could be used in the qualitative format for the routine detection of C. trachomatis and in the quantitative format for study of the pathogenesis of C. trachomatis-associated diseases. The assay demonstrated the potential to eliminate the need for confirmatory testing in almost all samples, thus reducing the turnaround time and the workload. PMID:16390971

A system of equations to approximate the pharmacokinetic parameters of lacosamide at steady state from one plasma sample.

PubMed

Cawello, Willi; Schäfer, Carina

2014-08-01

Frequent plasma sampling to monitor pharmacokinetic (PK) profile of antiepileptic drugs (AEDs), is invasive, costly and time consuming. For drugs with a well-defined PK profile, such as AED lacosamide, equations can accurately approximate PK parameters from one steady-state plasma sample. Equations were derived to approximate steady-state peak and trough lacosamide plasma concentrations (Cpeak,ss and Ctrough,ss, respectively) and area under concentration-time curve during dosing interval (AUCτ,ss) from one plasma sample. Lacosamide (ka: ∼2 h(-1); ke: ∼0.05 h(-1), corresponding to half-life of 13 h) was calculated to reach Cpeak,ss after ∼1 h (tmax,ss). Equations were validated by comparing approximations to reference PK parameters obtained from single plasma samples drawn 3-12h following lacosamide administration, using data from double-blind, placebo-controlled, parallel-group PK study. Values of relative bias (accuracy) between -15% and +15%, and root mean square error (RMSE) values≤15% (precision) were considered acceptable for validation. Thirty-five healthy subjects (12 young males; 11 elderly males, 12 elderly females) received lacosamide 100mg/day for 4.5 days. Equation-derived PK values were compared to reference mean Cpeak,ss, Ctrough,ss and AUCτ,ss values. Equation-derived PK data had a precision of 6.2% and accuracy of -8.0%, 2.9%, and -0.11%, respectively. Equation-derived versus reference PK values for individual samples obtained 3-12h after lacosamide administration showed correlation (R2) range of 0.88-0.97 for AUCτ,ss. Correlation range for Cpeak,ss and Ctrough,ss was 0.65-0.87. Error analyses for individual sample comparisons were independent of time. Derived equations approximated lacosamide Cpeak,ss, Ctrough,ss and AUCτ,ss using one steady-state plasma sample within validation range. Approximated PK parameters were within accepted validation criteria when compared to reference PK values. Copyright © 2014 Elsevier B.V. All rights reserved.

Characterization and speciation of mercury-bearing mine wastes using X-ray absorption spectroscopy

USGS Publications Warehouse

Kim, C.S.; Brown, Gordon E.; Rytuba, J.J.

2000-01-01

Mining of mercury deposits located in the California Coast Range has resulted in the release of mercury to the local environment and water supplies. The solubility, transport, and potential bioavailability of mercury are controlled by its chemical speciation, which can be directly determined for samples with total mercury concentrations greater than 100 mg kg-1 (ppm) using X-ray absorption spectroscopy (XAS). This technique has the additional benefits of being non-destructive to the sample, element-specific, relatively sensitive at low concentrations, and requiring minimal sample preparation. In this study, Hg L(III)-edge extended X-ray absorption fine structure (EXAFS) spectra were collected for several mercury mine tailings (calcines) in the California Coast Range. Total mercury concentrations of samples analyzed ranged from 230 to 1060 ppm. Speciation data (mercury phases present and relative abundances) were obtained by comparing the spectra from heterogeneous, roasted (calcined) mine tailings samples with a spectral database of mercury minerals and sorbed mercury complexes. Speciation analyses were also conducted on known mixtures of pure mercury minerals in order to assess the quantitative accuracy of the technique. While some calcine samples were found to consist exclusively of mercuric sulfide, others contain additional, more soluble mercury phases, indicating a greater potential for the release of mercury into solution. Also, a correlation was observed between samples from hot-spring mercury deposits, in which chloride levels are elevated, and the presence of mercury-chloride species as detected by the speciation analysis. The speciation results demonstrate the ability of XAS to identify multiple mercury phases in a heterogeneous sample, with a quantitative accuracy of ??25% for the mercury-containing phases considered. Use of this technique, in conjunction with standard microanalytical techniques such as X-ray diffraction and electron probe microanalysis, is beneficial in the prioritization and remediation of mercury-contaminated mine sites. (C) 2000 Elsevier Science B.V.

Development and validation of an ultra-performance liquid chromatography quadrupole time of flight mass spectrometry method for rapid quantification of free amino acids in human urine.

PubMed

Joyce, Richard; Kuziene, Viktorija; Zou, Xin; Wang, Xueting; Pullen, Frank; Loo, Ruey Leng

2016-01-01

An ultra-performance liquid chromatography quadrupole time of flight mass spectrometry (UPLC-qTOF-MS) method using hydrophilic interaction liquid chromatography was developed and validated for simultaneous quantification of 18 free amino acids in urine with a total acquisition time including the column re-equilibration of less than 18 min per sample. This method involves simple sample preparation steps which consisted of 15 times dilution with acetonitrile to give a final composition of 25 % aqueous and 75 % acetonitrile without the need of any derivatization. The dynamic range for our calibration curve is approximately two orders of magnitude (120-fold from the lowest calibration curve point) with good linearity (r (2) ≥ 0.995 for all amino acids). Good separation of all amino acids as well as good intra- and inter-day accuracy (<15 %) and precision (<15 %) were observed using three quality control samples at a concentration of low, medium and high range of the calibration curve. The limits of detection (LOD) and lower limit of quantification of our method were ranging from approximately 1-300 nM and 0.01-0.5 µM, respectively. The stability of amino acids in the prepared urine samples was found to be stable for 72 h at 4 °C, after one freeze thaw cycle and for up to 4 weeks at -80 °C. We have applied this method to quantify the content of 18 free amino acids in 646 urine samples from a dietary intervention study. We were able to quantify all 18 free amino acids in these urine samples, if they were present at a level above the LOD. We found our method to be reproducible (accuracy and precision were typically <10 % for QCL, QCM and QCH) and the relatively high sample throughput nature of this method potentially makes it a suitable alternative for the analysis of urine samples in clinical setting.

Measuring coercive control: what can we learn from national population surveys?

PubMed

Myhill, Andy

2015-03-01

Numerous academic studies point to gender symmetry in the prevalence of intimate partner violence (IPV). Many of these studies report findings from surveys with small and/or unrepresentative samples that have insufficient questions to differentiate adequately between different types of abuse. Data from a large, nationally representative survey suggest that, while the prevalence of situational violence is fairly symmetrical, coercive controlling abuse is highly gendered, with women overwhelmingly the victims. The authors conclude that more comprehensive measures are required in national surveys that consider a wider range of controlling behaviors as well as the meaning and impact of abuse. © The Author(s) 2015.

Characterization, Optimization, and Test of the NPSAT1 MEMS 3-Axis Rate Sensor Suite for Use in Small Satellite Attitude Control

DTIC Science & Technology

2007-09-01

Power Control and Filter Boards (PCFB) are powered. The anticipated temperature range is based on a model, and like all models, it is subject to...voltage regulation, filtering , or averaging at room temperature , and with no rate applied. This data was taken at 1K samples/sec, and resulted in an...buffering or amplification should be done as near to the signal source as possible. The low pass filter was added to the rate, BIT, and temperature

Experimental light scattering by positionally-controlled small particles — Implications for Planetary Science

NASA Astrophysics Data System (ADS)

Gritsevich, M.; Penttilä, A.; Maconi, G.; Kassamakov, I.; Martikainen, J.; Markkanen, J.; Vaisanen, T.; Helander, P.; Puranen, T.; Salmi, A.; Hæggström, E.; Muinonen, K.

2017-12-01

Electromagnetic scattering is a fundamental physical process that allows inferring characteristics of an object studied remotely. This possibility is enhanced by obtaining the light-scattering response at multiple wavelengths and viewing geometries, i.e., by considering a wider range of the phase angle (the angle between the incident light and the light reflected from the object) in the experiment. Within the ERC Advanced Grant project SAEMPL (http://cordis.europa.eu/project/rcn/107666_en.html) we have assembled an interdisciplinary group of scientists to develop a fully automated, 3D scatterometer that can measure scattered light at different wavelengths from small particulate samples. The setup comprises: (a) the PXI Express platform to synchronously record data from several photomultiplier tubes (PMTs); (b) a motorized rotation stage to precisely control the azimuthal angle of the PMTs around 360°; and (c) a versatile light source, whose wavelength, polarization, intensity, and beam shape can be precisely controlled. An acoustic levitator is used to hold the sample without touching it. The device is the first of its kind, since it measures controlled spectral angular scattering including all polarization effects, for an arbitrary object in the µm-cm size scale. It permits a nondestructive, disturbance-free measurement with control of the orientation and location of the scattering object. To demonstrate our approach we performed detailed measurements of light scattered by a Chelyabinsk LL5 chondrite particle, derived from the light-colored lithology sample of the meteorite. These measurements are cross-validated against the modeled light-scattering characteristics of the sample, i.e., the intensity and the degree of linear polarization of the reflected light, calculated with state-of-the-art electromagnetic techniques (see Muinonen et al., this meeting). We demonstrate a unique non-destructive approach to derive the optical properties of small grain samples which facilitates research on highly valuable planetary materials, such as samples returned from space missions or rare meteorites.

Abnormal resting-state cortical coupling in chronic tinnitus

PubMed Central

Schlee, Winfried; Hartmann, Thomas; Langguth, Berthold; Weisz, Nathan

2009-01-01

Background Subjective tinnitus is characterized by an auditory phantom perception in the absence of any physical sound source. Consequently, in a quiet environment, tinnitus patients differ from control participants because they constantly perceive a sound whereas controls do not. We hypothesized that this difference is expressed by differential activation of distributed cortical networks. Results The analysis was based on a sample of 41 participants: 21 patients with chronic tinnitus and 20 healthy control participants. To investigate the architecture of these networks, we used phase locking analysis in the 1–90 Hz frequency range of a minute of resting-state MEG recording. We found: 1) For tinnitus patients: A significant decrease of inter-areal coupling in the alpha (9–12 Hz) band and an increase of inter-areal coupling in the 48–54 Hz gamma frequency range relative to the control group. 2) For both groups: an inverse relationship (r = -.71) of the alpha and gamma network coupling. 3) A discrimination of 83% between the patient and the control group based on the alpha and gamma networks. 4) An effect of manifestation on the distribution of the gamma network: In patients with a tinnitus history of less than 4 years, the left temporal cortex was predominant in the gamma network whereas in patients with tinnitus duration of more than 4 years, the gamma network was more widely distributed including more frontal and parietal regions. Conclusion In the here presented data set we found strong support for an alteration of long-range coupling in tinnitus. Long-range coupling in the alpha frequency band was decreased for tinnitus patients while long-range gamma coupling was increased. These changes discriminate well between tinnitus and control participants. We propose a tinnitus model that integrates this finding in the current knowledge about tinnitus. Furthermore we discuss the impact of this finding to tinnitus therapies using Transcranial Magnetic Stimulation (TMS). PMID:19228390

Bioanalytical high-throughput selected reaction monitoring-LC/MS determination of selected estrogen receptor modulators in human plasma: 2000 samples/day.

PubMed

Zweigenbaum, J; Henion, J

2000-06-01

The high-throughput determination of small molecules in biological matrixes has become an important part of drug discovery. This work shows that increased throughput LC/MS/MS techniques can be used for the analysis of selected estrogen receptor modulators in human plasma where more than 2000 samples may be analyzed in a 24-h period. The compounds used to demonstrate the high-throughput methodology include tamoxifen, raloxifene, 4-hydroxytamoxifen, nafoxidine, and idoxifene. Tamoxifen and raloxifene are used in both breast cancer therapy and osteoporosis and have shown prophylactic potential for the reduction of the risk of breast cancer. The described strategy provides LC/MS/MS separation and quantitation for each of the five test articles in control human plasma. The method includes sample preparation employing liquid-liquid extraction in the 96-well format, an LC separation of the five compounds in less than 30 s, and selected reaction monitoring detection from low nano- to microgram per milliter levels. Precision and accuracy are determined where each 96-well plate is considered a typical "tray" having calibration standards and quality control (QC) samples dispersed through each plate. A concept is introduced where 24 96-well plates analyzed in 1 day is considered a "grand tray", and the method is cross-validated with standards placed only at the beginning of the first plate and the end of the last plate. Using idoxifene-d5 as an internal standard, the results obtained for idoxifene and tamoxifen satisfy current bioanalytical method validation criteria on two separate days where 2112 and 2304 samples were run, respectively. Method validation included 24-h autosampler stability and one freeze-thaw cycle stability for the extracts. Idoxifene showed acceptable results with accuracy ranging from 0.3% for the high quality control (QC) to 15.4% for the low QC and precision of 3.6%-13.9% relative standard deviation. Tamoxifen showed accuracy ranging from 1.6% to 13.8% and precision from 7.8% to 15.2%. The linear dynamic range for these compounds was 3 orders of magnitude. The limit of quantification was 5 and 50 ng/ mL for tamoxifen and idoxifene, respectively. The other compounds in this study in general satisfy the more relaxed bioanalytical acceptance criteria for modern drug discovery. It is suggested that the quantification levels reported in this high-throughput analysis example are adequate for many drug discovery and related early pharmaceutical studies.

Refractive index-based detection of gradient elution liquid chromatography using chip-integrated microring resonator arrays.

PubMed

Wade, James H; Bailey, Ryan C

2014-01-07

Refractive index-based sensors offer attractive characteristics as nondestructive and universal detectors for liquid chromatographic separations, but a small dynamic range and sensitivity to minor thermal perturbations limit the utility of commercial RI detectors for many potential applications, especially those requiring the use of gradient elutions. As such, RI detectors find use almost exclusively in sample abundant, isocratic separations when interfaced with high-performance liquid chromatography. Silicon photonic microring resonators are refractive index-sensitive optical devices that feature good sensitivity and tremendous dynamic range. The large dynamic range of microring resonators allows the sensors to function across a wide spectrum of refractive indices, such as that encountered when moving from an aqueous to organic mobile phase during a gradient elution, a key analytical advantage not supported in commercial RI detectors. Microrings are easily configured into sensor arrays, and chip-integrated control microrings enable real-time corrections of thermal drift. Thermal controls allow for analyses at any temperature and, in the absence of rigorous temperature control, obviates extended detector equilibration wait times. Herein, proof of concept isocratic and gradient elution separations were performed using well-characterized model analytes (e.g., caffeine, ibuprofen) in both neat buffer and more complex sample matrices. These experiments demonstrate the ability of microring arrays to perform isocratic and gradient elutions under ambient conditions, avoiding two major limitations of commercial RI-based detectors and maintaining comparable bulk RI sensitivity. Further benefit may be realized in the future through selective surface functionalization to impart degrees of postcolumn (bio)molecular specificity at the detection phase of a separation. The chip-based and microscale nature of microring resonators also make it an attractive potential detection technology that could be integrated within lab-on-a-chip and microfluidic separation devices.

Effectiveness of outpatient cognitive-behavioral therapy for adolescents under routine care conditions on behavioral and emotional problems rated by parents and patients: an observational study.

PubMed

Walter, Daniel; Dachs, Lydia; Faber, Martin; Goletz, Hildegard; Goertz-Dorten, Anja; Hautmann, Christopher; Kinnen, Claudia; Rademacher, Christiane; Schuermann, Stephanie; Metternich-Kaizman, Tanja Wolff; Doepfner, Manfred

2018-01-01

Few studies have examined the effectiveness of outpatient cognitive-behavioral therapy (CBT) delivered in routine care settings for children and adolescents with mental disorders. This observational study examined changes in behavioral and emotional problems of adolescents with mental disorders during routine outpatient CBT delivered at a university outpatient clinic and compared them with a historical control group of youths who received academic tutoring of comparable length and intensity. Assessments were made at the start and end of treatment (pre- and post-assessment) using parent ratings of the German versions of the Child Behavior Checklist (CBCL) and self-ratings of the Youth Self-Report (YSR) scale. For the main analysis, 677 adolescents aged 11‒21 years had complete data. Changes from pre- to post-assessment showed significant reductions in mental health problems on both parent- and self-ratings. Pre- to post-effect sizes (Cohen's d) were small-to-medium for the total sample (d = 0.23 to d = 0.62) and medium-to-large for those adolescents rated in the clinical range on each (sub)scale at the start of treatment (d = 0.65 to d = 1.48). We obtained medium net effect sizes (d = 0.69) for the CBCL and YSR total scores when patients in the clinical range were compared to historical controls. However, a substantial part of the sample remained in the clinical range at treatment end. The results suggest that CBT is effective for adolescents with mental disorders when administered under routine care conditions but must be interpreted conservatively due to the lack of a direct control condition.

Cytomegalovirus (CMV) DNA load in plasma for the diagnosis of CMV disease before engraftment in hematopoietic stem-cell transplant recipients.

PubMed

Limaye, A P; Huang, M L; Leisenring, W; Stensland, L; Corey, L; Boeckh, M

2001-02-01

Among hematopoietic stem-cell transplant (HSCT) recipients, cytomegalovirus (CMV) disease before engraftment is rare but often fatal, and cell-based diagnostic tests have low sensitivity in this clinical setting. We used the quantitative real-time polymerase chain reaction (PCR) assay to test for CMV DNA in plasma samples from 15 HSCT recipients who developed CMV disease before engraftment and from 33 matched control patients. CMV DNA was detected in plasma in 14 (93.3%) of the 15 patients who had CMV disease before engraftment, compared with 5 (15.2%) of 33 control patients (P<.001). CMV DNA was detected a median of 13 days before the onset of CMV disease (range, 0-35 days). The maximum CMV virus load in plasma was >1 log(10) higher among case patients than among control patients (median, 1700 [range, 50 to 5.5x107] vs. <50 [range, <50-350] CMV DNA copies/mL plasma, respectively; P<.001). Quantitative PCR for CMV DNA in plasma appears to be useful for the identification of HSCT recipients at risk for CMV disease before engraftment.

Short-Range Six-Axis Interferometer Controlled Positioning for Scanning Probe Microscopy

PubMed Central

Lazar, Josef; Klapetek, Petr; Valtr, Miroslav; Hrabina, Jan; Buchta, Zdenek; Cip, Onrej; Cizek, Martin; Oulehla, Jindrich; Sery, Mojmir

2014-01-01

We present a design of a nanometrology measuring setup which is a part of the national standard instrumentation for nanometrology operated by the Czech Metrology Institute (CMI) in Brno, Czech Republic. The system employs a full six-axis interferometric position measurement of the sample holder consisting of six independent interferometers. Here we report on description of alignment issues and accurate adjustment of orthogonality of the measuring axes. Consequently, suppression of cosine errors and reduction of sensitivity to Abbe offset is achieved through full control in all six degrees of freedom. Due to the geometric configuration including a wide basis of the two units measuring in y-direction and the three measuring in z-direction the angle resolution of the whole setup is minimize to tens of nanoradians. Moreover, the servo-control of all six degrees of freedom allows to keep guidance errors below 100 nrad. This small range system is based on a commercial nanopositioning stage driven by piezoelectric transducers with the range (200 × 200 × 10) μm. Thermally compensated miniature interferometric units with fiber-optic light delivery and integrated homodyne detection system were developed especially for this system and serve as sensors for othogonality alignment. PMID:24451463

Noise and Complexity in Human Postural Control: Interpreting the Different Estimations of Entropy

PubMed Central

Rhea, Christopher K.; Silver, Tobin A.; Hong, S. Lee; Ryu, Joong Hyun; Studenka, Breanna E.; Hughes, Charmayne M. L.; Haddad, Jeffrey M.

2011-01-01

Background Over the last two decades, various measures of entropy have been used to examine the complexity of human postural control. In general, entropy measures provide information regarding the health, stability and adaptability of the postural system that is not captured when using more traditional analytical techniques. The purpose of this study was to examine how noise, sampling frequency and time series length influence various measures of entropy when applied to human center of pressure (CoP) data, as well as in synthetic signals with known properties. Such a comparison is necessary to interpret data between and within studies that use different entropy measures, equipment, sampling frequencies or data collection durations. Methods and Findings The complexity of synthetic signals with known properties and standing CoP data was calculated using Approximate Entropy (ApEn), Sample Entropy (SampEn) and Recurrence Quantification Analysis Entropy (RQAEn). All signals were examined at varying sampling frequencies and with varying amounts of added noise. Additionally, an increment time series of the original CoP data was examined to remove long-range correlations. Of the three measures examined, ApEn was the least robust to sampling frequency and noise manipulations. Additionally, increased noise led to an increase in SampEn, but a decrease in RQAEn. Thus, noise can yield inconsistent results between the various entropy measures. Finally, the differences between the entropy measures were minimized in the increment CoP data, suggesting that long-range correlations should be removed from CoP data prior to calculating entropy. Conclusions The various algorithms typically used to quantify the complexity (entropy) of CoP may yield very different results, particularly when sampling frequency and noise are different. The results of this study are discussed within the context of the neural noise and loss of complexity hypotheses. PMID:21437281

A sensitive and selective liquid chromatography/tandem mass spectrometry method for quantitative analysis of efavirenz in human plasma.

PubMed

Srivastava, Praveen; Moorthy, Ganesh S; Gross, Robert; Barrett, Jeffrey S

2013-01-01

A selective and a highly sensitive method for the determination of the non-nucleoside reverse transcriptase inhibitor (NNRTI), efavirenz, in human plasma has been developed and fully validated based on high performance liquid chromatography tandem mass spectrometry (LC-MS/MS). Sample preparation involved protein precipitation followed by one to one dilution with water. The analyte, efavirenz was separated by high performance liquid chromatography and detected with tandem mass spectrometry in negative ionization mode with multiple reaction monitoring. Efavirenz and ¹³C₆-efavirenz (Internal Standard), respectively, were detected via the following MRM transitions: m/z 314.20243.90 and m/z 320.20249.90. A gradient program was used to elute the analytes using 0.1% formic acid in water and 0.1% formic acid in acetonitrile as mobile phase solvents, at a flow-rate of 0.3 mL/min. The total run time was 5 min and the retention times for the internal standard (¹³C₆-efavirenz) and efavirenz was approximately 2.6 min. The calibration curves showed linearity (coefficient of regression, r>0.99) over the concentration range of 1.0-2,500 ng/mL. The intraday precision based on the standard deviation of replicates of lower limit of quantification (LLOQ) was 9.24% and for quality control (QC) samples ranged from 2.41% to 6.42% and with accuracy from 112% and 100-111% for LLOQ and QC samples. The inter day precision was 12.3% and 3.03-9.18% for LLOQ and quality controls samples, and the accuracy was 108% and 95.2-108% for LLOQ and QC samples. Stability studies showed that efavirenz was stable during the expected conditions for sample preparation and storage. The lower limit of quantification for efavirenz was 1 ng/mL. The analytical method showed excellent sensitivity, precision, and accuracy. This method is robust and is being successfully applied for therapeutic drug monitoring and pharmacokinetic studies in HIV-infected patients.

Routine determination of sulfonylurea, imidazolinone, and sulfonamide herbicides at nanogram-per-liter concentrations by solid-phase extraction and liquid chromatography/mass spectrometry

USGS Publications Warehouse

Furlong, E.T.; Burkhardt, M.R.; Gates, Paul M.; Werner, S.L.; Battaglin, W.A.

2000-01-01

Sulfonylurea (SU), imidazolinone (IMI), and sulfonamide (SA) herbicides are new classes of low-application-rate herbicides increasingly used by farmers. Some of these herbicides affect both weed and crop species at low dosages and must be carefully used. Less is known about the effect of these compounds on non-crop plant species, but a concentration of 100 ng/l in water has been proposed as the threshold for possible plant toxicity for most of these herbicides. Hence, analytical methods must be capable of detecting SUs, IMIs, and SAs at concentrations less than 100 ng/l in ambient water samples. The authors developed a two-cartridge, solid-phase extraction method for isolating 12 SU, 3 IMI, and 1 SA herbicides by using high-performance liquid chromatography/electrospray ionization-mass spectrometry (HPLC/ESI-MS) to identify and quantify these herbicides to 10 ng/l. This method was used to analyze 196 surface- and ground-water samples collected from May to August 1998 throughout the Midwestern United States, and more than 100 quality-assurance and quality-control samples. During the 16 weeks of the study, the HPLC/ESI-MS maintained excellent calibration linearity across the calibration range from 5 to 500 ng/l, with correlation coefficients of 0.9975 or greater. Continuing calibration verification standards at 100-ng/l concentration were analyzed throughout the study, and the average measured concentrations for individual herbicides ranged from 93 to 100 ng/l. Recovery of herbicides from 27 reagent-water samples spiked at 50 and 100 ng/l ranged from 39 to 92%, and averaged 73%. The standard deviation of recoveries ranged from 14 to 26%, and averaged 20%. This variability reflects multiple instruments, operators, and the use of automated and manual sample preparation. Spiked environmental water samples had similar recoveries, although for some herbicides, the sample matrix enhanced recoveries by as much as 200% greater than the spiked concentration. This matrix enhancement was sample- and compound-dependent. Concentrations of herbicides in unspiked duplicate environmental samples were typically within 25% of each other. The results demonstrate the usefulness of HPLC/ESI-MS for determining low-application-rate herbicides at ambient concentrations. Copyright (C) 2000 Elsevier Science B.V.

Development and application of a validated HPLC method for the analysis of dissolution samples of levothyroxine sodium drug products.

PubMed

Collier, J W; Shah, R B; Bryant, A R; Habib, M J; Khan, M A; Faustino, P J

2011-02-20

A rapid, selective, and sensitive gradient HPLC method was developed for the analysis of dissolution samples of levothyroxine sodium tablets. Current USP methodology for levothyroxine (L-T(4)) was not adequate to resolve co-elutants from a variety of levothyroxine drug product formulations. The USP method for analyzing dissolution samples of the drug product has shown significant intra- and inter-day variability. The sources of method variability include chromatographic interferences introduced by the dissolution media and the formulation excipients. In the present work, chromatographic separation of levothyroxine was achieved on an Agilent 1100 Series HPLC with a Waters Nova-pak column (250 mm × 3.9 mm) using a 0.01 M phosphate buffer (pH 3.0)-methanol (55:45, v/v) in a gradient elution mobile phase at a flow rate of 1.0 mL/min and detection UV wavelength of 225 nm. The injection volume was 800 μL and the column temperature was maintained at 28°C. The method was validated according to USP Category I requirements. The validation characteristics included accuracy, precision, specificity, linearity, and analytical range. The standard curve was found to have a linear relationship (r(2)>0.99) over the analytical range of 0.08-0.8 μg/mL. Accuracy ranged from 90 to 110% for low quality control (QC) standards and 95 to 105% for medium and high QC standards. Precision was <2% at all QC levels. The method was found to be accurate, precise, selective, and linear for L-T(4) over the analytical range. The HPLC method was successfully applied to the analysis of dissolution samples of marketed levothyroxine sodium tablets. Published by Elsevier B.V.

Development and application of a validated HPLC method for the analysis of dissolution samples of levothyroxine sodium drug products

PubMed Central

Collier, J.W.; Shah, R.B.; Bryant, A.R.; Habib, M.J.; Khan, M.A.; Faustino, P.J.

2011-01-01

A rapid, selective, and sensitive gradient HPLC method was developed for the analysis of dissolution samples of levothyroxine sodium tablets. Current USP methodology for levothyroxine (l-T4) was not adequate to resolve co-elutants from a variety of levothyroxine drug product formulations. The USP method for analyzing dissolution samples of the drug product has shown significant intra- and inter-day variability. The sources of method variability include chromatographic interferences introduced by the dissolution media and the formulation excipients. In the present work, chromatographic separation of levothyroxine was achieved on an Agilent 1100 Series HPLC with a Waters Nova-pak column (250mm × 3.9mm) using a 0.01 M phosphate buffer (pH 3.0)–methanol (55:45, v/v) in a gradient elution mobile phase at a flow rate of 1.0 mL/min and detection UV wavelength of 225 nm. The injection volume was 800 µL and the column temperature was maintained at 28 °C. The method was validated according to USP Category I requirements. The validation characteristics included accuracy, precision, specificity, linearity, and analytical range. The standard curve was found to have a linear relationship (r2 > 0.99) over the analytical range of 0.08–0.8 µg/mL. Accuracy ranged from 90 to 110% for low quality control (QC) standards and 95 to 105% for medium and high QC standards. Precision was <2% at all QC levels. The method was found to be accurate, precise, selective, and linear for l-T4 over the analytical range. The HPLC method was successfully applied to the analysis of dissolution samples of marketed levothyroxine sodium tablets. PMID:20947276

Range of motion improves after massage in children with burns: a pilot study.

PubMed

Morien, Annie; Garrison, Diane; Smith, Nancy Keeney

2008-01-01

Little is known about the effect of massage on post-burn tissue in children. We conducted a pilot study to examine the effect of massage (3-5 days) on mood and range of motion (ROM) in eight post-burn children. Participants showed significant increases in ROM from Time 1 (pre-massage, first day) to Time 2 (post-massage, last day) in massaged tissue but not control (non-massaged) tissue. Mood was elevated throughout the study and thus did not change across time. Although massage improved ROM, we are cautious in our interpretation because of the small sample size.

Depth profiling of galvanoaluminium-nickel coatings on steel by UV- and VIS-LIBS

NASA Astrophysics Data System (ADS)

Nagy, T. O.; Pacher, U.; Giesriegl, A.; Weimerskirch, M. J. J.; Kautek, W.

2017-10-01

Laser-induced depth profiling was applied to the investigation of galvanised steel sheets as a typical modern multi-layer coating system for environmental corrosion protection. The samples were ablated stepwise by the use of two different wavelengths of a frequency-converted Nd:YAG-laser, 266 nm and 532 nm, with a pulse duration of τ = 4 ns at fluences ranging from F = 50 to 250 J cm-2. The emission light of the resulting plasma was analysed as a function of both penetration depth and elemental spectrum in terms of linear correlation analysis. Elemental depth profiles were calculated and compared to EDX-cross sections of the cut sample. A proven mathematical algorithm designed for the reconstruction of layer structures from distorted emission traces caused by the Gaussian ablation profile can even resolve thin intermediate layers in terms of depth and thickness. The obtained results were compared to a purely thermally controlled ablation model. Thereby light-plasma coupling is suggested to be a possible cause of deviations in the ablation behaviour of Al. The average ablation rate h as a function of fluence F for Ni ranges from 1 to 3.5 μm/pulse for λ = 266 nm as well as for λ = 532 nm. In contrast, the range of h for Al differs from 2 to 4 μm/pulse for λ = 532 nm and 4 to 8 μm/pulse for λ = 266 nm in the exact same fluence range on the exact same sample.

Ground- and Surface-Water Chemistry of Handcart Gulch, Park County, Colorado, 2003-2006

USGS Publications Warehouse

Verplanck, Philip L.; Manning, Andrew H.; Kimball, Briant A.; McCleskey, R. Blaine; Runkel, Robert L.; Caine, Jonathan S.; Adams, Monique; Gemery-Hill, Pamela A.; Fey, David L.

2008-01-01

As part of a multidisciplinary project to determine the processes that control ground-water chemistry and flow in mineralized alpine environments, ground- and surface-water samples from Handcart Gulch, Colorado were collected for analysis of inorganic solutes and water and dissolved sulfate stable isotopes in selected samples. The primary aim of this study was to document variations in ground-water chemistry in Handcart Gulch and to identify changes in water chemistry along the receiving stream of Handcart Gulch. Water analyses are reported for ground-water samples collected from 12 wells in Handcart Gulch, Colorado. Samples were collected between August 2003 and October 2005. Water analyses for surface-water samples are reported for 50 samples collected from Handcart Gulch and its inflows during a low-flow tracer injection on August 6, 2003. In addition, water analyses are reported for three other Handcart Gulch stream samples collected in September 2005 and March 2006. Reported analyses include field parameters (pH, specific conductance, temperature, dissolved oxygen, and Eh), major and trace constituents, oxygen and hydrogen isotopic composition of water and oxygen and sulfur isotopic composition of dissolved sulfate. Ground-water samples from this study are Ca-SO4 type and range in pH from 2.5 to 6.8. Most of the samples (75 percent) have pH values between 3.3 and 4.3. Surface water samples are also Ca-SO4 type and have a narrower range in pH (2.7?4.0). Ground- and surface-water samples vary from relatively dilute (specific conductance of 68 ?S/cm) to concentrated (specific conductance of 2,000 ?S/cm).

Recommended Maximum Temperature For Mars Returned Samples

NASA Technical Reports Server (NTRS)

Beaty, D. W.; McSween, H. Y.; Czaja, A. D.; Goreva, Y. S.; Hausrath, E.; Herd, C. D. K.; Humayun, M.; McCubbin, F. M.; McLennan, S. M.; Hays, L. E.

2016-01-01

The Returned Sample Science Board (RSSB) was established in 2015 by NASA to provide expertise from the planetary sample community to the Mars 2020 Project. The RSSB's first task was to address the effect of heating during acquisition and storage of samples on scientific investigations that could be expected to be conducted if the samples are returned to Earth. Sample heating may cause changes that could ad-versely affect scientific investigations. Previous studies of temperature requirements for returned mar-tian samples fall within a wide range (-73 to 50 degrees Centigrade) and, for mission concepts that have a life detection component, the recommended threshold was less than or equal to -20 degrees Centigrade. The RSSB was asked by the Mars 2020 project to determine whether or not a temperature requirement was needed within the range of 30 to 70 degrees Centigrade. There are eight expected temperature regimes to which the samples could be exposed, from the moment that they are drilled until they are placed into a temperature-controlled environment on Earth. Two of those - heating during sample acquisition (drilling) and heating while cached on the Martian surface - potentially subject samples to the highest temperatures. The RSSB focused on the upper temperature limit that Mars samples should be allowed to reach. We considered 11 scientific investigations where thermal excursions may have an adverse effect on the science outcome. Those are: (T-1) organic geochemistry, (T-2) stable isotope geochemistry, (T-3) prevention of mineral hydration/dehydration and phase transformation, (T-4) retention of water, (T-5) characterization of amorphous materials, (T-6) putative Martian organisms, (T-7) oxidation/reduction reactions, (T-8) (sup 4) He thermochronometry, (T-9) radiometric dating using fission, cosmic-ray or solar-flare tracks, (T-10) analyses of trapped gasses, and (T-11) magnetic studies.

Binomial leap methods for simulating stochastic chemical kinetics.

PubMed

Tian, Tianhai; Burrage, Kevin

2004-12-01

This paper discusses efficient simulation methods for stochastic chemical kinetics. Based on the tau-leap and midpoint tau-leap methods of Gillespie [D. T. Gillespie, J. Chem. Phys. 115, 1716 (2001)], binomial random variables are used in these leap methods rather than Poisson random variables. The motivation for this approach is to improve the efficiency of the Poisson leap methods by using larger stepsizes. Unlike Poisson random variables whose range of sample values is from zero to infinity, binomial random variables have a finite range of sample values. This probabilistic property has been used to restrict possible reaction numbers and to avoid negative molecular numbers in stochastic simulations when larger stepsize is used. In this approach a binomial random variable is defined for a single reaction channel in order to keep the reaction number of this channel below the numbers of molecules that undergo this reaction channel. A sampling technique is also designed for the total reaction number of a reactant species that undergoes two or more reaction channels. Samples for the total reaction number are not greater than the molecular number of this species. In addition, probability properties of the binomial random variables provide stepsize conditions for restricting reaction numbers in a chosen time interval. These stepsize conditions are important properties of robust leap control strategies. Numerical results indicate that the proposed binomial leap methods can be applied to a wide range of chemical reaction systems with very good accuracy and significant improvement on efficiency over existing approaches. (c) 2004 American Institute of Physics.

A Study of Production of Miscibility Gap Alloys with Controlled Structures

NASA Technical Reports Server (NTRS)

Parr, R. A.; Johnston, M. H.; Burka, J. A.; Davis, J. H.; Lee, J. A.

1983-01-01

Composite materials were directionally solidified using a new technique to align the constituents longitudinally along the length of the specimen. In some instances a tin coating was applied and diffused into the sample to form a high transition temperature superconducting phase. The superconducting properties were measured and compared with the properties obtained for powder composites and re-directionally solidified powder compacts. The samples which were compacted and redirectionally solidified showed the highest transition temperature and wildest transition range. This indicates that both steps, powder compaction and resolidification, determine the final superconducting properties of the material.

Partial purification of Leucine aminopeptidase (LAP) in Acromegalic Sample of Iraqi Patients

NASA Astrophysics Data System (ADS)

Uloom Mohammad, Taghreed

2018-05-01

Acromagaly is a syndrome caused by increased growth hormone secretion from the frontal lobe of the pituitary gland. A Leucine aminopeptidase (EC 34111) activity has been assayed in (30) patients sera samples(15 female and 15 males) with acromegaly age range between (3050) years and (30) sera of healthy as control group (16 femal and 14 male) age range between (3050) years. The goal of the research was partial purified of enzyme from sera patients with acromegaly by dialysis gel filtration by using sephdex G50 and ion exchange chromatography by using DEAE cellulose A50. The results showed a single peak by using gel filtration and the activity was reached to 152 U/L. Two isoenzymes were obtained by using ion exchange chromatography and the purity degree of isoenzymse (I II) were (125) and (128) fold respectively. The current study found that the enzyme showed no significant difference between the healthy and the patients.

Measurement of Area and Personal Breathing Zone Concentrations of Diesel Particulate Matter (DPM) during Oil and Gas Extraction Operations, including Hydraulic Fracturing

PubMed Central

Esswein, Eric J.; Alexander-Scott, Marissa; Snawder, John; Breitenstein, Michael

2018-01-01

Diesel engines serve many purposes in modern oil and gas extraction activities. Diesel particulate matter (DPM) emitted from diesel engines is a complex aerosol that may cause adverse health effects depending on exposure dose and duration. This study reports on personal breathing zone (PBZ) and area measurements for DPM (expressed as elemental carbon) during oil and gas extraction operations including drilling, completions (which includes hydraulic fracturing) and servicing work. Researchers at the National Institute for Occupational Safety and Health (NIOSH) collected 104 full-shift air samples (49 PBZ and 55 area) in Colorado, North Dakota, Texas, and New Mexico during a four year period from 2008-2012 The arithmetic mean (AM) of the full shift TWA PBZ samples was 10 μg/m3; measurements ranged from 0.1 to 52 μg/m3. The geometric mean (GM) for the PBZ samples was 7 μg/m3. The AM of the TWA area measurements was 17 μg/m3 and ranged from 0.1 to 68 μg/m3. The GM for the area measurements was 9.5 μg/m3. Differences between the GMs of the PBZ samples and area samples were not statistically different (P>0.05). Neither the Occupational Safety and Health Administration (OSHA), NIOSH, nor the American Conference of Governmental Industrial Hygienists (ACGIH) have established occupational exposure limits (OEL) for DPM. However, the State of California, Department of Health Services lists a time-weighted average (TWA) OEL for DPM as elemental carbon (EC) exposure of 20 μg/m3. Five of 49 (10.2%) PBZ TWA measurements exceeded the 20 μg/m3 EC criterion. These measurements were collected on Sandmover and Transfer Belt (T-belt) Operators, Blender and Chemical Truck Operators, and Water Transfer Operators during hydraulic fracturing operations. Recommendations to minimize DPM exposures include elimination (locating diesel-driven pumps away from well sites), substitution, (use of alternative fuels), engineering controls using advanced emissions controls technologies, administrative controls (configuration of well sites), hazard communication and worker training. PMID:29053946

Measurement of area and personal breathing zone concentrations of diesel particulate matter (DPM) during oil and gas extraction operations, including hydraulic fracturing.

PubMed

Esswein, Eric J; Alexander-Scott, Marissa; Snawder, John; Breitenstein, Michael

2018-01-01

Diesel engines serve many purposes in modern oil and gas extraction activities. Diesel particulate matter (DPM) emitted from diesel engines is a complex aerosol that may cause adverse health effects depending on exposure dose and duration. This study reports on personal breathing zone (PBZ) and area measurements for DPM (expressed as elemental carbon) during oil and gas extraction operations including drilling, completions (which includes hydraulic fracturing), and servicing work. Researchers at the National Institute for Occupational Safety and Health (NIOSH) collected 104 full-shift air samples (49 PBZ and 55 area) in Colorado, North Dakota, Texas, and New Mexico during a four-year period from 2008-2012. The arithmetic mean (AM) of the full shift TWA PBZ samples was 10 µg/m 3 ; measurements ranged from 0.1-52 µg/m 3 . The geometric mean (GM) for the PBZ samples was 7 µg/m 3 . The AM of the TWA area measurements was 17 µg/m 3 and ranged from 0.1-68 µg/m 3 . The GM for the area measurements was 9.5 µg/m 3 . Differences between the GMs of the PBZ samples and area samples were not statistically different (P > 0.05). Neither the Occupational Safety and Health Administration (OSHA), NIOSH, nor the American Conference of Governmental Industrial Hygienists (ACGIH) have established occupational exposure limits (OEL) for DPM. However, the State of California, Department of Health Services lists a time-weighted average (TWA) OEL for DPM as elemental carbon (EC) exposure of 20 µg/m 3 . Five of 49 (10.2%) PBZ TWA measurements exceeded the 20 µg/m 3 EC criterion. These measurements were collected on Sandmover and Transfer Belt (T-belt) Operators, Blender and Chemical Truck Operators, and Water Transfer Operators during hydraulic fracturing operations. Recommendations to minimize DPM exposures include elimination (locating diesel-driven pumps away from well sites), substitution, (use of alternative fuels), engineering controls using advanced emission control technologies, administrative controls (configuration of well sites), hazard communication, and worker training.

Product/Process (P/P) Models For The Defense Waste Processing Facility (DWPF): Model Ranges And Validation Ranges For Future Processing

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

Jantzen, C.; Edwards, T.

Radioactive high level waste (HLW) at the Savannah River Site (SRS) has successfully been vitrified into borosilicate glass in the Defense Waste Processing Facility (DWPF) since 1996. Vitrification requires stringent product/process (P/P) constraints since the glass cannot be reworked once it is poured into ten foot tall by two foot diameter canisters. A unique “feed forward” statistical process control (SPC) was developed for this control rather than statistical quality control (SQC). In SPC, the feed composition to the DWPF melter is controlled prior to vitrification. In SQC, the glass product would be sampled after it is vitrified. Individual glass property-compositionmore » models form the basis for the “feed forward” SPC. The models transform constraints on the melt and glass properties into constraints on the feed composition going to the melter in order to guarantee, at the 95% confidence level, that the feed will be processable and that the durability of the resulting waste form will be acceptable to a geologic repository.« less

Dynamic defect annealing in wurtzite MgZnO implanted with Ar ions

NASA Astrophysics Data System (ADS)

Azarov, A. Yu.; Wendler, E.; Du, X. L.; Kuznetsov, A. Yu.; Svensson, B. G.

2015-09-01

Successful implementation of ion beams for modification of ternary ZnO-based oxides requires understanding and control of radiation-induced defects. Here, we study structural disorder in wurtzite ZnO and MgxZn1-xO (x ⩽ 0.3) samples implanted at room and 15 K temperatures with Ar ions in a wide fluence range (5 × 1012-3 × 1016 cm-2). The samples were characterized by Rutherford backscattering/channeling spectrometry performed in-situ without changing the sample temperature. The results show that all the samples exhibit high radiation resistance and cannot be rendered amorphous even for high ion fluences. Increasing the Mg content leads to some damage enhancement near the surface region; however, irrespective of the Mg content, the fluence dependence of bulk damage in the samples displays the so-called IV-stage evolution with a reverse temperature effect for high ion fluences.

Activin B is a novel biomarker for chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME) diagnosis: a cross sectional study.

PubMed

Lidbury, Brett A; Kita, Badia; Lewis, Donald P; Hayward, Susan; Ludlow, Helen; Hedger, Mark P; de Kretser, David M

2017-03-16

Investigations of activin family proteins as serum biomarkers for chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME). CFS/ME is a disease with complex, wide-ranging symptoms, featuring persistent fatigue of 6 months or longer, particularly post exertion. No definitive biomarkers are available. A cross-sectional, observational study of CFS/ME patients fulfilling the 2003 Canadian Consensus Criteria, in parallel with healthy non-fatigued controls, was conducted. Comparisons with a previously defined activin reference population were also performed. For the total study cohort the age range was 18-65 years with a female: male participant ratio of greater than 3:1. All participants were assessed via a primary care community clinic. Blood samples were collected for pathology testing after physical examination and orthostatic intolerance assessment. Cytokines, activin A, activin B and follistatin were also measured in sera from these samples. All data were compared between the CFS/ME and control cohorts, with the activins and follistatin also compared with previously defined reference intervals. Serum activin B levels for CFS/ME participants were significantly elevated when compared to the study controls, as well as the established reference interval. Serum activin A and follistatin were within their normal ranges. All routine and special pathology markers were within the normal laboratory reference intervals for the total study cohort, with no significant differences detected between CFS/ME and control groups. Also, no significant differences were detected for IL-2, IL-4, IL-6, IL-10, IL-17A, TNF or IFN-gamma. Elevated activin B levels together with normal activin A levels identified patients with the diagnostic symptoms of CFS/ME, thus providing a novel serum based test. The activins have multiple physiological roles and capture the diverse array of symptoms experienced by CFS/ME patients.

Cycle life test of secondary spacecraft cells

NASA Technical Reports Server (NTRS)

Harkness, J. D.

1980-01-01

The results of the life cycling program on rechargeable calls are reported. Information on required data, the use of which the data will be put, application details, including orbital description, charge control methods, load rquirements, etc., are given. Cycle tests were performed on 660 sealed, nickel cadmium cells. The cells consisted of seven sample classifications ranging form 3.0 to 20 amp. hours. Nickel cadmium, silver cadmium, and silver zinc sealed cells, excluding synchronous orbit and accelerated test packs were added. The capacities of the nickel cadmium cells, the silver cadmium and the silver zinc cells differed in range of amp hrs. The cells were cylced under different load, charge control, and temperature conditions. All cell packs are recharged by use of a pack voltage limit. All charging is constant current until the voltage limit is reached.

Infrared spectroscopic ellipsometry of micrometer-sized SiO2 line gratings

NASA Astrophysics Data System (ADS)

Walder, Cordula; Zellmeier, Matthias; Rappich, Jörg; Ketelsen, Helge; Hinrichs, Karsten

2017-09-01

For the design and process control of periodic nano-structured surfaces spectroscopic ellipsometry is already established in the UV-VIS spectral regime. The objective of this work is to show the feasibility of spectroscopic ellipsometry in the infrared, exemplarily, on micrometer-sized SiO2 line gratings grown on silicon wafers. The grating period ranges from 10 to about 34 μm. The IR-ellipsometric spectra of the gratings exhibit complex changes with structure variations. Especially in the spectral range of the oxide stretching modes, the presence of a Rayleigh singularity can lead to pronounced changes of the spectrum with the sample geometry. The IR-ellipsometric spectra of the gratings are well reproducible by calculations with the RCWA method (Rigorous Coupled Wave Analysis). Therefore, infrared spectroscopic ellipsometry allows the quantitative characterization and process control of micrometer-sized structures.

Performance evaluation of a mitogenome capture and Illumina sequencing protocol using non-probative, case-type skeletal samples: Implications for the use of a positive control in a next-generation sequencing procedure.

PubMed

Marshall, Charla; Sturk-Andreaggi, Kimberly; Daniels-Higginbotham, Jennifer; Oliver, Robert Sean; Barritt-Ross, Suzanne; McMahon, Timothy P

2017-11-01

Next-generation ancient DNA technologies have the potential to assist in the analysis of degraded DNA extracted from forensic specimens. Mitochondrial genome (mitogenome) sequencing, specifically, may be of benefit to samples that fail to yield forensically relevant genetic information using conventional PCR-based techniques. This report summarizes the Armed Forces Medical Examiner System's Armed Forces DNA Identification Laboratory's (AFMES-AFDIL) performance evaluation of a Next-Generation Sequencing protocol for degraded and chemically treated past accounting samples. The procedure involves hybridization capture for targeted enrichment of mitochondrial DNA, massively parallel sequencing using Illumina chemistry, and an automated bioinformatic pipeline for forensic mtDNA profile generation. A total of 22 non-probative samples and associated controls were processed in the present study, spanning a range of DNA quantity and quality. Data were generated from over 100 DNA libraries by ten DNA analysts over the course of five months. The results show that the mitogenome sequencing procedure is reliable and robust, sensitive to low template (one ng control DNA) as well as degraded DNA, and specific to the analysis of the human mitogenome. Haplotypes were overall concordant between NGS replicates and with previously generated Sanger control region data. Due to the inherent risk for contamination when working with low-template, degraded DNA, a contamination assessment was performed. The consumables were shown to be void of human DNA contaminants and suitable for forensic use. Reagent blanks and negative controls were analyzed to determine the background signal of the procedure. This background signal was then used to set analytical and reporting thresholds, which were designated at 4.0X (limit of detection) and 10.0X (limit of quantiation) average coverage across the mitogenome, respectively. Nearly all human samples exceeded the reporting threshold, although coverage was reduced in chemically treated samples resulting in a ∼58% passing rate for these poor-quality samples. A concordance assessment demonstrated the reliability of the NGS data when compared to known Sanger profiles. One case sample was shown to be mixed with a co-processed sample and two reagent blanks indicated the presence of DNA above the analytical threshold. This contamination was attributed to sequencing crosstalk from simultaneously sequenced high-quality samples to include the positive control. Overall this study demonstrated that hybridization capture and Illumina sequencing provide a viable method for mitogenome sequencing of degraded and chemically treated skeletal DNA samples, yet may require alternative measures of quality control. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Driver steering dynamics measured in car simulator under a range of visibility and roadmaking conditions

NASA Technical Reports Server (NTRS)

Allen, R. W.; Mcruer, D. T.

1977-01-01

A simulation experiment was conducted to determine the effect of reduced visibility on driver lateral (steering) control. The simulator included a real car cab and a single lane road image projected on a screen six feet in front of the driver. Simulated equations of motion controlled apparent car lane position in response to driver steering actions, wind gusts, and road curvature. Six drivers experienced a range of visibility conditions at various speeds with assorted roadmaking configurations (mark and gap lengths). Driver describing functions were measured and detailed parametric model fits were determined. A pursuit model employing a road curvature feedforward was very effective in explaining driver behavior in following randomly curving roads. Sampled-data concepts were also effective in explaining the combined effects of reduced visibility and intermittent road markings on the driver's dynamic time delay. The results indicate the relative importance of various perceptual variables as the visual input to the driver's steering control process is changed.

Magnetic, structural and magnetocaloric properties of Ni-Si and Ni-Al thermoseeds for self-controlled hyperthermia.

PubMed

Pandey, Sudip; Quetz, Abdiel; Aryal, Anil; Dubenko, Igor; Mazumdar, Dipanjan; Stadler, Shane; Ali, Naushad

2017-11-01

Self-controlled hyperthermia is a non-invasive technique used to kill or destroy cancer cells while preserving normal surrounding tissues. We have explored bulk magnetic Ni-Si and Ni-Al alloys as a potential thermoseeds. The structural, magnetic and magnetocaloric properties of the samples were investigated, including saturation magnetisation, Curie temperature (T C ), and magnetic and thermal hysteresis, using room temperature X-ray diffraction and magnetometry. The annealing time, temperature and the effects of homogenising the thermoseeds were studied to determine the functional hyperthermia applications. The bulk Ni-Si and Ni-Al binary alloys have Curie temperatures in the desired range, 316 K-319 K (43 °C-46 °C), which is suitable for magnetic hyperthermia applications. We have found that T C strictly follows a linear trend with doping concentration over a wide range of temperature. The magnetic ordering temperature and the magnetic properties can be controlled through substitution in these binary alloys.

An Adaptable Multiple Power Source for Mass Spectrometry and other Scientific Instruments

DOE PAGES

Lin, Tzu-Yung; Anderson, Gordon A.; Norheim, Randolph V.; ...

2015-09-18

Power supplies are commonly used in the operation of many types of scientific equipment, including mass spectrometers and ancillary instrumentation. A generic modern mass spectrometer comprises an ionization source, such as electrospray ionization (ESI), ion transfer devices such as ion funnels and multipole ion guides, and ion signal detection apparatus. Very often such platforms include, or are interfaced with ancillary elements in order to manipulate samples before or after ionization. In order to operate such scientific instruments, numerous direct current (DC) channels and radio frequency (RF) signals are required, along with other controls such as temperature regulation. In particular, DCmore » voltages in the range of ±400 V, along with MHz range RF signals with peak-to-peak amplitudes in the hundreds of volts range are commonly used to transfer ionized samples under vacuum. Additionally, an ESI source requires a high voltage (HV) DC source capable of producing several thousand volts and heaters capable of generating temperatures up to 300°C. All of these signals must be properly synchronized and managed in order to carry out ion trapping, accumulation and detection.« less

[Epigenetic research of cognitive deficit in schizophrenia: some methodological considerations].

PubMed

Lezheiko, T V; Alfimova, M V

To highlights the problems of assessing cognitive deficits in schizophrenia, relevant to the epigenetic, as well as a wide range of other approaches to the search for biological bases of cognition. The literature on the weaknesses in the evaluation of cognitive functions in patients with schizophrenia are summarized and discussed. The analysis is illustrated by our experience in developing a cognitive battery and a sample to examine relationships between DNA methylation in blood cells and cognitive deficits in schizophrenia. It has been shown that to assess cognitive deficits in patients and to reduce the influence of confounders in epigenetic analysis it is necessary (1) to use a battery with the existing co-normative data in the target population, which allows to evaluate representativeness of control and patients included in the study sample, (2) to verify the theoretically driven battery structure using normative population and a cohort of patients, (3) to balance groups of cases and controls on the number, age and sex, for which an individual matching of cases and controls is best suited, (4) to conduct an additional statistical analysis controlling for education and smoking.

Comparison of serum Concentration of Se, Pb, Mg, Cu, Zn, between MS patients and healthy controls

PubMed Central

Alizadeh, Anahita; Mehrpour, Omid; Nikkhah, Karim; Bayat, Golnaz; Espandani, Mahsa; Golzari, Alireza; Jarahi, Lida; Foroughipour, Mohsen

2016-01-01

Introduction Multiple Sclerosis (MS) is defined as one of the inflammatory autoimmune disorders and is common. Its exact etiology is unclear. There are some evidences on the role of environmental factors in susceptible genetics. The aim of this study is to evaluate the possible role of Selenium, Zinc, Copper, Lead and Magnesium metals in Multiple Sclerosis patients. Methods In the present analytical cross-sectional study, 56 individuals including 26 patients and 30 healthy controls were enrolled in the evaluation. The serum level of Se, Zn, Cu, Pb were quantified in graphite furnace conditions and flame conditions by utilizing an atomic absorption Perkin Elmer spectrophotometer 3030. The serum levels of Mg were measured by auto analyzer 1500 BT. The mean level of minerals (Zn, Pb, Cu, Mg, Se) in serum samples were compared in both cases and controls. The mean level of minerals (Zn, Pb, Cu, Mg, Se) in serum samples were compared in both cases and controls by using independent-samples t-test for normal distribution and Mann-Whitney U test as a non-parametric test. All statistical analyses were carried out using SPSS 11.0. Results As well as the Zn, Cu, and Se, there was no significant difference between MS patients and healthy individuals in Pb concentrations (p-value = 0.11, 0.14, 0.32, 0.20 respectively) but the level of Mg was significantly different (p= 0.001). Conclusion All serum concentrations of Zn, Pb, Se, Cu in both groups were in normal ranges and there was no difference in MS patients compared with the healthy group who were matched in genetics. Blood level of Mg was significantly lower in MS patients. But it should be noted that even with the low level of serum magnesium in MS patients, this value is still in the normal range. PMID:27757186

Synthesis of TiO2 nanotubes with ZnO nanoparticles to achieve antibacterial properties and stem cell compatibility

NASA Astrophysics Data System (ADS)

Liu, Wenwen; Su, Penglei; Chen, Su; Wang, Na; Ma, Yuanping; Liu, Yiran; Wang, Jinshu; Zhang, Zhenting; Li, Hongyi; Webster, Thomas J.

2014-07-01

To endow titanium (Ti) with antibacterial properties, different concentrations of zinc oxide (ZnO) nanoparticles were decorated on anodized titanium dioxide (TiO2) nanotubes by a simple hydrothermal treatment method. The particle sizes of ZnO, which were evenly distributed and tightly adherent to the walls of the Ti nanotubes, ranged from 20-50 nm. Results from this study showed that Zn was released from the TiO2 nanotubes in a constant, slow, and biologically inspired manner. Importantly, the results showed that the ZnO decorated TiO2 nanotubular samples inhibited Streptococcus mutants and Porphyromonas gingivalis growth compared to control unmodified Ti samples. Specifically, S. mutants and P. gingivalis growth were both reduced 45-85% on the ZnO decorated Ti samples compared to Ti controls after 7 days of culture. When examining the mechanism of action, it has been further found for the first time that the ZnO decorated Ti samples inhibited the expression of Streptococcus mutans bacterial adhesion genes. Lastly, the results showed that the same samples which decreased bacterial growth the most (0.015 M precursor Zn(NO3)2 samples) did not inhibit mesenchymal stem cell growth compared to Ti controls for up to 7 days. In summary, results from this study showed that compared to plain TiO2 nanotubes, TiO2 decorated with 0.015 M ZnO provided unprecedented antibacterial properties while maintaining the stem cell proliferation capacity necessary for enhancing the use of Ti in numerous medical applications, particularly in dentistry.

Pyrethroids in human breast milk: occurrence and nursing daily intake estimation.

PubMed

Corcellas, Cayo; Feo, Maria Luisa; Torres, Joao Paulo; Malm, Olaf; Ocampo-Duque, William; Eljarrat, Ethel; Barceló, Damià

2012-10-15

There is an assumption that pyrethroid pesticides are converted to non-toxic metabolites by hydrolysis in mammals. However, some recent works have shown their bioaccumulation in human breast milk collected in areas where pyrethroids have been widely used for agriculture or malaria control. In this work, thirteen pyrethroids have been studied in human breast milk samples coming from areas without pyrethroid use for malaria control, such as Brazil, Colombia and Spain. The concentrations of pyrethroids ranged from 1.45 to 24.2 ng g⁻¹ lw. Cypermethrin, λ-cyhalothrin, permethrin and esfenvalerate/fenvalerate were present in all the studied samples. The composition of pyrethroid mixture depended on the country of origin of the samples, bifenthrin being the most abundant in Brazilian samples, λ-cyhalothrin in Colombian and permethrin in Spanish ones. When the pyrethroid concentrations were confronted against the number of gestations, an exponential decay was observed. Moreover, a time trend study was carried out in Brazil, where additional archived pool samples were analyzed, corresponding to years when pyrethroids were applied for dengue epidemic control. In these cases, total pyrethroid levels reached up to 128 ng g⁻¹ lw, and concentrations decreased when massive use was not allowed. Finally, daily intake estimation of nursing infants was calculated in each country and compared to acceptable WHO levels. The estimated daily intakes for nursing infants were always below the acceptable daily intake levels, nevertheless in certain samples the detected concentrations were very close to the maximum acceptable levels. Copyright © 2012 Elsevier Ltd. All rights reserved.

Synthesis of TiO2 nanotubes with ZnO nanoparticles to achieve antibacterial properties and stem cell compatibility.

PubMed

Liu, Wenwen; Su, Penglei; Chen, Su; Wang, Na; Ma, Yuanping; Liu, Yiran; Wang, Jinshu; Zhang, Zhenting; Li, Hongyi; Webster, Thomas J

2014-08-07

To endow titanium (Ti) with antibacterial properties, different concentrations of zinc oxide (ZnO) nanoparticles were decorated on anodized titanium dioxide (TiO2) nanotubes by a simple hydrothermal treatment method. The particle sizes of ZnO, which were evenly distributed and tightly adherent to the walls of the Ti nanotubes, ranged from 20-50 nm. Results from this study showed that Zn was released from the TiO2 nanotubes in a constant, slow, and biologically inspired manner. Importantly, the results showed that the ZnO decorated TiO2 nanotubular samples inhibited Streptococcus mutants and Porphyromonas gingivalis growth compared to control unmodified Ti samples. Specifically, S. mutants and P. gingivalis growth were both reduced 45-85% on the ZnO decorated Ti samples compared to Ti controls after 7 days of culture. When examining the mechanism of action, it has been further found for the first time that the ZnO decorated Ti samples inhibited the expression of Streptococcus mutans bacterial adhesion genes. Lastly, the results showed that the same samples which decreased bacterial growth the most (0.015 M precursor Zn(NO3)2 samples) did not inhibit mesenchymal stem cell growth compared to Ti controls for up to 7 days. In summary, results from this study showed that compared to plain TiO2 nanotubes, TiO2 decorated with 0.015 M ZnO provided unprecedented antibacterial properties while maintaining the stem cell proliferation capacity necessary for enhancing the use of Ti in numerous medical applications, particularly in dentistry.

Analysis of cocaine and three of its metabolites in hair by gas chromatography-mass spectrometry using ion-trap detection for CI/MS/MS.

PubMed

Cognard, Emmanuelle; Rudaz, Serge; Bouchonnet, Stéphane; Staub, Christian

2005-11-05

A sensitive GC/CI/MS/MS method was developed for the simultaneous determination of cocaine (COC), anhydroecgonine methylester (cocaine pyrolysis product, AEME), ecgonine methylester (cocaine enzymatic hydrolysis product, EME) and cocaethylene (cocaine with ethanol trans-esterification product, COET) in human hair samples. After acid hydrolysis, hair samples were extracted with an automated solid phase extraction (SPE). The analysis of cocaine and its three metabolites was performed using an ion-trap spectrometer in positive chemical ionization with isobutane as gas reagent. The procedure was validated. Weighted linear regression was found appropriate in a concentration range of 0.10-5.00 ng/mg for AEME, 0.05-5.00 ng/mg for COC, EME and COET. The limit of detection was estimated at 0.005 ng/mg for COC and COET, at 0.025 ng/mg for EME, and at 0.050 ng/mg for AEME. Method performance was evaluated in terms of trueness and precision using quality control (QC) samples over the investigated ranges. Method selectivity and robustness were also demonstrated.

Oxygen partial pressure dependence of thermoelectric power factor in polycrystalline n-type SrTiO3: Consequences for long term stability in thermoelectric oxides

NASA Astrophysics Data System (ADS)

Sharma, Peter A.; Brown-Shaklee, Harlan J.; Ihlefeld, Jon F.

2017-04-01

The Seebeck coefficient and electrical conductivity have been measured as functions of oxygen partial pressure over the range of 10-22 to 10-1 atm at 1173 K for a 10% niobium-doped SrTiO3 ceramic with a grain size comparable to the oxygen diffusion length. Temperature-dependent measurements performed from 320 to 1275 K for as-prepared samples reveal metallic-like conduction and good thermoelectric properties. However, upon exposure to progressively increasing oxygen partial pressure, the thermoelectric power factor decreased over time scales of 24 h, culminating in a three order of magnitude reduction over the entire operating range. Identical measurements on single crystal samples show negligible changes in the power factor so that the instability of ceramic samples is primarily tied to the kinetics of grain boundary diffusion. This work provides a framework for understanding the stability of thermoelectric properties in oxides under different atmospheric conditions. The control of the oxygen atmosphere remains a significant challenge in oxide thermoelectrics.

High-throughput powder diffraction measurement system consisting of multiple MYTHEN detectors at beamline BL02B2 of SPring-8

NASA Astrophysics Data System (ADS)

Kawaguchi, S.; Takemoto, M.; Osaka, K.; Nishibori, E.; Moriyoshi, C.; Kubota, Y.; Kuroiwa, Y.; Sugimoto, K.

2017-08-01

In this study, we developed a user-friendly automatic powder diffraction measurement system for Debye-Scherrer geometry using a capillary sample at beamline BL02B2 of SPring-8. The measurement system consists of six one-dimensional solid-state (MYTHEN) detectors, a compact auto-sampler, wide-range temperature control systems, and a gas handling system. This system enables to do the automatic measurement of temperature dependence of the diffraction patterns for multiple samples. We introduced two measurement modes in the MYTHEN system and developed new attachments for the sample environment such as a gas handling system. The measurement modes and the attachments can offer in situ and/or time-resolved measurements in an extended temperature range between 25 K and 1473 K and various gas atmospheres and pressures. The results of the commissioning and performance measurements using reference materials (NIST CeO2 674b and Si 640c), V2O3 and Ti2O3, and a nanoporous coordination polymer are presented.

Analysis of polar and non-polar VOCs from ambient and source matrices: Development of a new canister autosampler which meets TO-15 QA/QC criteria

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

Burnett, M.L.W.; Neal, D.; Uchtman, R.

1997-12-31

Approximately 108 of the Hazardous Air Pollutants (HAPs) specified in the 1990 Clean Air Act Amendments are classified as volatile organic compounds (VOCs). Of the 108 VOCs, nearly 35% are oxygenated or polar compounds. While more than one sample introduction technique exists for the analysis of these air toxics, SUMMA{reg_sign} canister sampling is suitable for the most complete range of analytes. A broad concentration range of polar and non-polar species can be analyzed from canisters. A new canister autosampler, the Tekmar AUTOCan{trademark} Elite autosampler, has been developed which incorporates the autosampler and concentrator into a single unit. Analysis of polarmore » and non-polar VOCs has been performed. This paper demonstrates adherence to the technical acceptance objectives outlined in the TO-15 methodology including initial calibration, daily calibration, blank analysis, method detection limits and laboratory control samples. The analytical system consists of a Tekmar AUTOCan{trademark} Elite autosampler interfaced to a Hewlett Packard{reg_sign} 5890/5972 MSD.« less

Nickel and chromium levels in the saliva of a Saudi sample treated with fixed orthodontic appliances.

PubMed

Talic, Nabeel F; Alnahwi, Hasan H; Al-Faraj, Ali S

2013-10-01

The aim of this study was to measure the amount of nickel (Ni) and chromium (Cr) released into the saliva of Saudi patients treated with fixed orthodontic appliances. Ninety salivary samples were collected in a cross-sectional manner. Forty samples were collected from patients (17 males, 23 females) with fixed orthodontic appliances after different periods of orthodontic treatment ranging from the first month and up to 32 months into treatment. The fixed orthodontic appliance consisted of 4 bands, 20 stainless steel brackets, and upper and lower nickel titanium or stainless-steel arch wires. The other 50 samples were collected from people without appliances (24 males, 26 females). Samples were analyzed using Inductive Coupled Plasma/Mass Spectrometry and Inductively Coupled Plasma Optical Emission Spectroscopy to measure Ni and Cr levels, respectively. Student's t-test was used to compare Ni and Cr levels in the treated and untreated control groups. The mean Ni level was 4.197 μg/L in the experimental group and 2.3 μg/L in the control group (p < 0.05). The mean Cr level was 2.9 μg/L in the experimental group and 3.3 μg/L in the control group (p < 0.05). Fixed orthodontic appliances resulted in a non-toxic increase in salivary levels of Ni, but no change in Cr levels. Duration of orthodontic treatment did not affect Ni and Cr levels in the saliva.