Determination of extremely low (236)U/(238)U isotope ratios in environmental samples by sector-field inductively coupled plasma mass spectrometry using high-efficiency sample introduction.

PubMed

Boulyga, Sergei F; Heumann, Klaus G

2006-01-01

A method by inductively coupled plasma mass spectrometry (ICP-MS) was developed which allows the measurement of (236)U at concentration ranges down to 3 x 10(-14)g g(-1) and extremely low (236)U/(238)U isotope ratios in soil samples of 10(-7). By using the high-efficiency solution introduction system APEX in connection with a sector-field ICP-MS a sensitivity of more than 5,000 counts fg(-1) uranium was achieved. The use of an aerosol desolvating unit reduced the formation rate of uranium hydride ions UH(+)/U(+) down to a level of 10(-6). An abundance sensitivity of 3 x 10(-7) was observed for (236)U/(238)U isotope ratio measurements at mass resolution 4000. The detection limit for (236)U and the lowest detectable (236)U/(238)U isotope ratio were improved by more than two orders of magnitude compared with corresponding values by alpha spectrometry. Determination of uranium in soil samples collected in the vicinity of Chernobyl nuclear power plant (NPP) resulted in that the (236)U/(238)U isotope ratio is a much more sensitive and accurate marker for environmental contamination by spent uranium in comparison to the (235)U/(238)U isotope ratio. The ICP-MS technique allowed for the first time detection of irradiated uranium in soil samples even at distances more than 200 km to the north of Chernobyl NPP (Mogilev region). The concentration of (236)U in the upper 0-10 cm soil layers varied from 2 x 10(-9)g g(-1) within radioactive spots close to the Chernobyl NPP to 3 x 10(-13)g g(-1) on a sampling site located by >200 km from Chernobyl.

Quantitative evaluation of analyte transport on microfluidic paper-based analytical devices (μPADs).

PubMed

Ota, Riki; Yamada, Kentaro; Suzuki, Koji; Citterio, Daniel

2018-02-07

The transport efficiency during capillary flow-driven sample transport on microfluidic paper-based analytical devices (μPADs) made from filter paper has been investigated for a selection of model analytes (Ni 2+ , Zn 2+ , Cu 2+ , PO 4 3- , bovine serum albumin, sulforhodamine B, amaranth) representing metal cations, complex anions, proteins and anionic molecules. For the first time, the transport of the analytical target compounds rather than the sample liquid, has been quantitatively evaluated by means of colorimetry and absorption spectrometry-based methods. The experiments have revealed that small paperfluidic channel dimensions, additional user operation steps (e.g. control of sample volume, sample dilution, washing step) as well as the introduction of sample liquid wicking areas allow to increase analyte transport efficiency. It is also shown that the interaction of analytes with the negatively charged cellulosic paper substrate surface is strongly influenced by the physico-chemical properties of the model analyte and can in some cases (Cu 2+ ) result in nearly complete analyte depletion during sample transport. The quantitative information gained through these experiments is expected to contribute to the development of more sensitive μPADs.

Sugar microanalysis by HPLC with benzoylation: improvement via introduction of a C-8 cartridge and a high efficiency ODS column.

PubMed

Miyagi, Michiko; Yokoyama, Hirokazu; Hibi, Toshifumi

2007-07-01

An HPLC protocol for sugar microanalysis based on the formation of ultraviolet-absorbing benzoyl chloride derivatives was improved. Here, samples were prepared with a C-8 cartridge and analyzed with a high efficiency ODS column, in which porous spherical silica particles 3 microm in diameter were packed. These devices allowed us to simultaneously quantify multiple sugars and sugar alcohols up to 10 ng/ml and to provide satisfactory separations of some sugars, such as fructose and myo-inositol and sorbitol and mannitol. This protocol, which does not require special apparatuses, should become a powerful tool in sugar research.

Development of a High-Throughput Microwave Imaging System for Concealed Weapons Detection

DTIC Science & Technology

2016-07-15

hardware. Index Terms—Microwave imaging, multistatic radar, Fast Fourier Transform (FFT). I. INTRODUCTION Near-field microwave imaging is a non-ionizing...configuration, but its computational demands are extreme. Fast Fourier Transform (FFT) imaging has long been used to efficiently construct images sampled with...Simulated image of 25 point scatterers imaged at range 1.5m, with array layout depicted in Fig. 3. Left: image formed with Equation (5) ( Fourier

Pneumatic Microvalve-Based Hydrodynamic Sample Injection for High-Throughput, Quantitative Zone Electrophoresis in Capillaries

PubMed Central

2015-01-01

A hybrid microchip/capillary electrophoresis (CE) system was developed to allow unbiased and lossless sample loading and high-throughput repeated injections. This new hybrid CE system consists of a poly(dimethylsiloxane) (PDMS) microchip sample injector featuring a pneumatic microvalve that separates a sample introduction channel from a short sample loading channel, and a fused-silica capillary separation column that connects seamlessly to the sample loading channel. The sample introduction channel is pressurized such that when the pneumatic microvalve opens briefly, a variable-volume sample plug is introduced into the loading channel. A high voltage for CE separation is continuously applied across the loading channel and the fused-silica capillary separation column. Analytes are rapidly separated in the fused-silica capillary, and following separation, high-sensitivity MS detection is accomplished via a sheathless CE/ESI-MS interface. The performance evaluation of the complete CE/ESI-MS platform demonstrated that reproducible sample injection with well controlled sample plug volumes could be achieved by using the PDMS microchip injector. The absence of band broadening from microchip to capillary indicated a minimum dead volume at the junction. The capabilities of the new CE/ESI-MS platform in performing high-throughput and quantitative sample analyses were demonstrated by the repeated sample injection without interrupting an ongoing separation and a linear dependence of the total analyte ion abundance on the sample plug volume using a mixture of peptide standards. The separation efficiency of the new platform was also evaluated systematically at different sample injection times, flow rates, and CE separation voltages. PMID:24865952

Pneumatic Microvalve-Based Hydrodynamic Sample Injection for High-Throughput, Quantitative Zone Electrophoresis in Capillaries

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

Kelly, Ryan T.; Wang, Chenchen; Rausch, Sarah J.

2014-07-01

A hybrid microchip/capillary CE system was developed to allow unbiased and lossless sample loading and high throughput repeated injections. This new hybrid CE system consists of a polydimethylsiloxane (PDMS) microchip sample injector featuring a pneumatic microvalve that separates a sample introduction channel from a short sample loading channel and a fused silica capillary separation column that connects seamlessly to the sample loading channel. The sample introduction channel is pressurized such that when the pneumatic microvalve opens briefly, a variable-volume sample plug is introduced into the loading channel. A high voltage for CE separation is continuously applied across the loading channelmore » and the fused silica capillary separation column. Analytes are rapidly separated in the fused silica capillary with high resolution. High sensitivity MS detection after CE separation is accomplished via a sheathless CE/ESI-MS interface. The performance evaluation of the complete CE/ESI-MS platform demonstrated that reproducible sample injection with well controlled sample plug volumes could be achieved by using the PDMS microchip injector. The absence of band broadening from microchip to capillary indicated a minimum dead volume at the junction. The capabilities of the new CE/ESI-MS platform in performing high throughput and quantitative sample analyses were demonstrated by the repeated sample injection without interrupting an ongoing separation and a good linear dependence of the total analyte ion abundance on the sample plug volume using a mixture of peptide standards. The separation efficiency of the new platform was also evaluated systematically at different sample injection times, flow rates and CE separation voltages.« less

The use of environmental DNA in invasive species surveillance of the Great Lakes commercial bait trade.

PubMed

Nathan, Lucas R; Jerde, Christopher L; Budny, Michelle L; Mahon, Andrew R

2015-04-01

Over 180 non-native species have been introduced in the Laurentian Great Lakes region, many posing threats to native species and ecosystem functioning. One potential pathway for introductions is the commercial bait trade; unknowing or unconcerned anglers commonly release unused bait into aquatic systems. Previous surveillance efforts of this pathway relied on visual inspection of bait stocks in retail shops, which can be time and cost prohibitive and requires a trained individual that can rapidly and accurately identify cryptic species. Environmental DNA (eDNA) surveillance, a molecular tool that has been used for surveillance in aquatic environments, can be used to efficiently detect species at low abundances. We collected and analyzed 576 eDNA samples from 525 retail bait shops throughout the Laurentian Great Lake states. We used eDNA techniques to screen samples for multiple aquatic invasive species (AIS) that could be transported in the bait trade, including bighead (Hypophthalmichthys nobilis) and silver carp (H. molitrix), round goby (Neogobius melanostomus), tubenose goby (Proterorhinus marmoratus), Eurasian rudd (Scardinius erythrophthalmus), and goldfish (Carassius auratus). Twenty-seven samples were positive for at least one target species (4.7% of samples), and all target species were found at least once, except bighead carp. Despite current regulations, the bait trade remains a potential pathway for invasive species introductions in the Great Lakes region. Alterations to existing management strategies regarding the collection, transportation, and use of live bait are warranted, including new and updated regulations, to prevent future introductions of invasive species in the Great Lakes via the bait trade. © 2014 Society for Conservation Biology.

A preliminary investigation of sleep quality in functional neurological disorders: Poor sleep appears common, and is associated with functional impairment.

PubMed

Graham, Christopher D; Kyle, Simon D

2017-07-15

Functional neurological disorders (FND) are disabling conditions for which there are few empirically-supported treatments. Disturbed sleep appears to be part of the FND context; however, the clinical importance of sleep disturbance (extent, characteristics and impact) remains largely unknown. We described sleep quality in two samples, and investigated the relationship between sleep and FND-related functional impairment. We included a sample recruited online via patient charities (N=205) and a consecutive clinical sample (N=20). Participants completed validated measures of sleep quality and sleep characteristics (e.g. total sleep time, sleep efficiency), mood, and FND-related functional impairment. Poor sleep was common in both samples (89% in the clinical range), which was characterised by low sleep efficiency (M=65.40%) and low total sleep time (M=6.05h). In regression analysis, sleep quality was negatively associated with FND-related functional impairment, accounting for 16% of the variance and remaining significant after the introduction of mood variables. These preliminary analyses suggest that subjective sleep disturbance (low efficiency, short sleep) is common in FND. Sleep quality was negatively associated with the functional impairment attributed to FND, independent of depression. Therefore, sleep disturbance may be a clinically important feature of FND. Copyright © 2017 Elsevier B.V. All rights reserved.

Invasive aspergillosis in severely neutropenic patients over 18 years: impact of intranasal amphotericin B and HEPA filtration.

PubMed

Withington, S; Chambers, S T; Beard, M E; Inder, A; Allen, J R; Ikram, R B; Schousboe, M I; Heaton, D C; Spearing, R I; Hart, D N

1998-01-01

The impact of intranasal amphotericin B and high-efficiency particulate air (HEPA) filtration on the incidence of invasive aspergillosis was reviewed in patients from 1977 to 1994 undergoing intensive chemotherapy. Overall, the incidence of proven invasive aspergillosis was reduced from 24.4% (1977-1984) to 7.1% (1985-1991) (P < 0.001) following the introduction of intranasal prophylaxis, but when probable cases of aspergillosis were included and lymphoma cases excluded, there was no change in incidence. Following the introduction of HEPA filtration, patient exposure to aspergillus spores as measured by air sampling was markedly reduced and there were no new cases of invasive aspergillosis. HEPA filtration proved effective in reducing invasive aspergillosis and has allowed increasingly aggressive treatment regimens to be introduced.

Microfluidic-Based sample chips for radioactive solutions

DOE PAGES

Tripp, J. L.; Law, J. D.; Smith, T. E.; ...

2015-01-01

Historical nuclear fuel cycle process sampling techniques required sample volumes ranging in the tens of milliliters. The radiation levels experienced by analytical personnel and equipment, in addition to the waste volumes generated from analysis of these samples, have been significant. These sample volumes also impacted accountability inventories of required analytes during process operations. To mitigate radiation dose and other issues associated with the historically larger sample volumes, a microcapillary sample chip was chosen for further investigation. The ability to obtain microliter volume samples coupled with a remote automated means of sample loading, tracking, and transporting to the analytical instrument wouldmore » greatly improve analytical efficiency while reducing both personnel exposure and radioactive waste volumes. Sample chip testing was completed to determine the accuracy, repeatability, and issues associated with the use of microfluidic sample chips used to supply µL sample volumes of lanthanide analytes dissolved in nitric acid for introduction to an analytical instrument for elemental analysis.« less

Measurement of isotope ratios on transient signals by MC-ICP-MS.

PubMed

Günther-Leopold, Ines; Wernli, Beat; Kopajtic, Zlatko; Günther, Detlef

2004-01-01

Precise and accurate isotope ratio measurements are an important task in many applications such as isotope-dilution mass spectrometry, bioavailability studies, or the determination of isotope variations in geological or nuclear samples. The technique of MC-ICP-MS has attracted much attention because it permits the precise measurement of isotope compositions for a wide range of elements combined with excellent detection limits due to high ionisation efficiencies. However, the results are based mainly on measurements using continuous sample introduction. In the present study the determination of isotope ratios on various transient signals with a time duration of 30 to 60 s has been achieved by coupling high-performance liquid chromatography to a multicollector inductively coupled plasma mass spectrometer. In order to investigate the origin of ratio drifts across the transient signals for this hyphenated technique, measurements with the same standard solutions were also carried out using a flow-injection device for sample introduction. As a result of this application it could be concluded that the main source of the bias in the measured isotope ratios is within the ICP-MS instead of fractionation effects on the chromatographic column material. Preliminary studies on short transient signals of gaseous samples (dry plasma) showed a reverse fractionation effect compared with wet plasma conditions (flow injection and HPLC).

Refining Collective Coordinates and Improving Free Energy Representation in Variational Enhanced Sampling.

PubMed

Yang, Yi Isaac; Parrinello, Michele

2018-06-12

Collective variables are used often in many enhanced sampling methods, and their choice is a crucial factor in determining sampling efficiency. However, at times, searching for good collective variables can be challenging. In a recent paper, we combined time-lagged independent component analysis with well-tempered metadynamics in order to obtain improved collective variables from metadynamics runs that use lower quality collective variables [ McCarty, J.; Parrinello, M. J. Chem. Phys. 2017 , 147 , 204109 ]. In this work, we extend these ideas to variationally enhanced sampling. This leads to an efficient scheme that is able to make use of the many advantages of the variational scheme. We apply the method to alanine-3 in water. From an alanine-3 variationally enhanced sampling trajectory in which all the six dihedral angles are biased, we extract much better collective variables able to describe in exquisite detail the protein complex free energy surface in a low dimensional representation. The success of this investigation is helped by a more accurate way of calculating the correlation functions needed in the time-lagged independent component analysis and from the introduction of a new basis set to describe the dihedral angles arrangement.

Ammonia modification of activated carbon to enhance carbon dioxide adsorption: Effect of pre-oxidation

NASA Astrophysics Data System (ADS)

Shafeeyan, Mohammad Saleh; Daud, Wan Mohd Ashri Wan; Houshmand, Amirhossein; Arami-Niya, Arash

2011-02-01

A commercial granular activated carbon (GAC) was subjected to thermal treatment with ammonia for obtaining an efficient carbon dioxide (CO2) adsorbent. In general, CO2 adsorption capacity of activated carbon can be increased by introduction of basic nitrogen functionalities onto the carbon surface. In this work, the effect of oxygen surface groups before introduction of basic nitrogen functionalities to the carbon surface on CO2 adsorption capacity was investigated. For this purpose two different approaches of ammonia treatment without preliminary oxidation and amination of oxidized samples were studied. Modified carbons were characterized by elemental analysis and Fourier Transform Infrared spectroscopy (FT-IR) to study the impact of changes in surface chemistry and formation of specific surface groups on adsorption properties. The texture of the samples was characterized by conducting N2 adsorption/desorption at -196 °C. CO2 capture performance of the samples was investigated using a thermogravimetric analysis (TGA). It was found that in both modification techniques, the presence of nitrogen functionalities on carbon surface generally increased the CO2 adsorption capacity. The results indicated that oxidation followed by high temperature ammonia treatment (800 °C) considerably enhanced the CO2 uptake at higher temperatures.

Comparative study on Ga1-xZnxN1-yOy oxynitride synthesized by different techniques for application in photocatalytic hydrogen production

NASA Astrophysics Data System (ADS)

Menon, Sumithra Sivadas; Baskar, K.; Singh, Shubra

2017-06-01

Hydrogen evolution by overall water splitting has emerged as a potential method for green energy generation due to the introduction of highly efficient photocatalysts active under visible region of spectra. In the present work, we focus on a comparative study of the properties of Ga1-xZnxN1-yOy oxynitride samples synthesized by two techniques and their effect on the sample properties. The samples were prepared by both traditional nitridation technique and solution combustion method. Room temperature photoluminescence studies revealed the introduction of additional energy levels above the valence band which in turns broadens the valence band and subsequently reduces the band gap. The band gap narrowing was further confirmed using diffuse reflectance spectroscopy and Valence band X-ray photoelectron spectroscopy (VB-XPS). It was also realized from VB XPS that the reduction of band gap in both the samples was due to upshift of valence band without affecting the conduction band. The presence of disorder activated modes in the samples was examined using temperature dependent Raman spectroscopy. In this work we corroborate the theoretical prediction reported by Al-Jassim et. al that the bandgap narrowing mechanism in ZnO rich solid solution and GaN rich solid solution is asymmetric and a significant bandgap reduction could be observed for ZnO rich solid solution than GaN rich.

Luminescent down shifting effect of Ce-doped yttrium aluminum garnet thin films on solar cells

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

Shao, Guojian; Lou, Chaogang; Kang, Jian

2015-12-21

Ce-doped yttrium aluminum garnet (YAG:Ce) thin films as luminescent down shifting (LDS) materials are introduced into the module of crystalline silicon solar cells. The films are deposited by RF magnetron sputtering on the lower surface of the quartz glass. They convert ultraviolet and blue light into yellow light. Experiments show that the introduction of YAG:Ce films improves the conversion efficiency from 18.45% of the cells to 19.27% of the module. The increasing efficiency is attributed to LDS effect of YAG:Ce films and the reduced reflection of short wavelength photons. Two intentionally selected samples with similar reflectivities are used to evaluatemore » roughly the effect of LDS alone on the solar cells, which leads to a relative increase by 2.68% in the conversion efficiency.« less

Efficient dynamic graph construction for inductive semi-supervised learning.

PubMed

Dornaika, F; Dahbi, R; Bosaghzadeh, A; Ruichek, Y

2017-10-01

Most of graph construction techniques assume a transductive setting in which the whole data collection is available at construction time. Addressing graph construction for inductive setting, in which data are coming sequentially, has received much less attention. For inductive settings, constructing the graph from scratch can be very time consuming. This paper introduces a generic framework that is able to make any graph construction method incremental. This framework yields an efficient and dynamic graph construction method that adds new samples (labeled or unlabeled) to a previously constructed graph. As a case study, we use the recently proposed Two Phase Weighted Regularized Least Square (TPWRLS) graph construction method. The paper has two main contributions. First, we use the TPWRLS coding scheme to represent new sample(s) with respect to an existing database. The representative coefficients are then used to update the graph affinity matrix. The proposed method not only appends the new samples to the graph but also updates the whole graph structure by discovering which nodes are affected by the introduction of new samples and by updating their edge weights. The second contribution of the article is the application of the proposed framework to the problem of graph-based label propagation using multiple observations for vision-based recognition tasks. Experiments on several image databases show that, without any significant loss in the accuracy of the final classification, the proposed dynamic graph construction is more efficient than the batch graph construction. Copyright © 2017 Elsevier Ltd. All rights reserved.

Natural attenuation, biostimulation and bioaugmentation of landfill leachate management

NASA Astrophysics Data System (ADS)

Er, X. Y.; Seow, T. W.; Lim, C. K.; Ibrahim, Z.

2018-04-01

Landfills used for solid waste management will lead to leachate production. Proper leachate management is highly essential to be paid attention to protect the environment and living organisms’ health and safety. In this study, the remedial strategies used for leachate management were natural attenuation, biostimulation and bioaugmentation. All treatment samples were treated via 42-days combined anaerobic-aerobic treatment and the treatment efficiency was studied by measuring the removal rate of COD and ammonia nitrogen. In this study, all remedial strategies showed different degrees of contaminants removal. Lowest contaminants removal rate was achieved via bioaugmentation of B. panacihumi strain ZB1, which were 39.4% of COD and 37.6% of ammonia nitrogen removed from the leachate sample. Higher contaminants removal rate was achieved via natural attenuation and biostimulation. Native microbial population was able to remove 41% of COD and 59% of ammonia nitrogen from the leachate sample. The removal efficiency could be further improved via biostimulation to trigger microbial growth and decontamination rate. Through biostimulation, 58% of COD and 51.8% of ammonia nitrogen were removed from the leachate sample. In conclusion, natural attenuation and biostimulation should be the main choice for leachate management to avoid any unexpected impacts due to introduction of exogenous species.

Impact of the New Abbott mPLUS Feature on Clinical Laboratory Efficiencies of Abbott RealTime Assays for Detection of HIV-1, Hepatitis C Virus, Hepatitis B Virus, Chlamydia trachomatis, and Neisseria gonorrhoeae

PubMed Central

Jones, Sara; Wiesneth, Russ; Barry, Cathy; Webb, Erika; Belova, Larissa; Dolan, Peggy; Ho, Shiaolan; Abravaya, Klara; Cloherty, Gavin

2013-01-01

Diagnostic laboratories are under increasing pressure to improve and expand their services. Greater flexibility in sample processing is a critical factor that can improve the time to results while reducing reagent waste, making laboratories more efficient and cost-effective. The introduction of the Abbott mPLUS feature, with the capacity for extended use of amplification reagents, significantly increases the flexibility of the m2000 platform and enables laboratories to customize their workflows based on sample arrival patterns. The flexibility in sample batch size offered by mPLUS enables significant reductions in processing times. For hepatitis B virus tests, a reduction in sample turnaround times of up to 30% (105 min) was observed for batches of 12 samples compared with those for batches of 24 samples; for Chlamydia trachomatis/Neisseria gonorrhoeae tests, the ability to run batches of 24 samples reduced the turnaround time by 83% (54 min) compared with that for batches of 48 samples. Excellent correlations between mPLUS and m2000 standard condition results were observed for all RealTime viral load assays evaluated in this study, with correlation r values of 0.998 for all assays tested. For the qualitative RealTime C. trachomatis/N. gonorrhoeae assay, the overall agreements between the two conditions tested were >98% for C. trachomatis and 100% for N. gonorrhoeae. Comparable precision results were observed for the two conditions tested for all RealTime assays. The enhanced mPLUS capability provides clinical laboratories with increased efficiencies to meet increasingly stringent turnaround time requirements without increased costs associated with discarding partially used amplification reagents. PMID:24088850

Impact of the New Abbott mPLUS feature on clinical laboratory efficiencies of abbott RealTime assays for detection of HIV-1, Hepatitis C Virus, Hepatitis B Virus, Chlamydia trachomatis, and Neisseria gonorrhoeae.

PubMed

Lucic, Danijela; Jones, Sara; Wiesneth, Russ; Barry, Cathy; Webb, Erika; Belova, Larissa; Dolan, Peggy; Ho, Shiaolan; Abravaya, Klara; Cloherty, Gavin

2013-12-01

Diagnostic laboratories are under increasing pressure to improve and expand their services. Greater flexibility in sample processing is a critical factor that can improve the time to results while reducing reagent waste, making laboratories more efficient and cost-effective. The introduction of the Abbott mPLUS feature, with the capacity for extended use of amplification reagents, significantly increases the flexibility of the m2000 platform and enables laboratories to customize their workflows based on sample arrival patterns. The flexibility in sample batch size offered by mPLUS enables significant reductions in processing times. For hepatitis B virus tests, a reduction in sample turnaround times of up to 30% (105 min) was observed for batches of 12 samples compared with those for batches of 24 samples; for Chlamydia trachomatis/Neisseria gonorrhoeae tests, the ability to run batches of 24 samples reduced the turnaround time by 83% (54 min) compared with that for batches of 48 samples. Excellent correlations between mPLUS and m2000 standard condition results were observed for all RealTime viral load assays evaluated in this study, with correlation r values of 0.998 for all assays tested. For the qualitative RealTime C. trachomatis/N. gonorrhoeae assay, the overall agreements between the two conditions tested were >98% for C. trachomatis and 100% for N. gonorrhoeae. Comparable precision results were observed for the two conditions tested for all RealTime assays. The enhanced mPLUS capability provides clinical laboratories with increased efficiencies to meet increasingly stringent turnaround time requirements without increased costs associated with discarding partially used amplification reagents.

Externally pressurized porous cylinder for multiple surface aerosol generation and method of generation

DOEpatents

Apel, Charles T.; Layman, Lawrence R.; Gallimore, David L.

1988-01-01

A nebulizer for generating aerosol having small droplet sizes and high efficiency at low sample introduction rates. The nebulizer has a cylindrical gas permeable active surface. A sleeve is disposed around the cylinder and gas is provided from the sleeve to the interior of the cylinder formed by the active surface. In operation, a liquid is provided to the inside of the gas permeable surface. The gas contacts the wetted surface and forms small bubbles which burst to form an aerosol. Those bubbles which are large are carried by momentum to another part of the cylinder where they are renebulized. This process continues until the entire sample is nebulized into aerosol sized droplets.

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.

Analysis of the volatile organic matter of engine piston deposits by direct sample introduction thermal desorption gas chromatography/mass spectrometry.

PubMed

Diaby, M; Kinani, S; Genty, C; Bouchonnet, S; Sablier, M; Le Negrate, A; El Fassi, M

2009-12-01

This article establishes an alternative method for the characterization of volatiles organic matter (VOM) contained in deposits of the piston first ring grooves of diesel engines using a ChromatoProbe direct sample introduction (DSI) device coupled to gas chromatography/mass spectrometry (GC/MS) analysis. The addition of an organic solvent during thermal desorption leads to an efficient extraction and a good chromatographic separation of extracted products. The method was optimized investigating the effects of several solvents, the volume added to the solid sample, and temperature programming of the ChromatoProbe DSI device. The best results for thermal desorption were found using toluene as an extraction solvent and heating the programmable temperature injector from room temperature to 300 degrees C with a temperature step of 105 degrees C. With the use of the optimized thermal desorption conditions, several components have been positively identified in the volatile fraction of the deposits: aromatics, antioxidants, and antioxidant degradation products. Moreover, this work highlighted the presence of diesel fuel in the VOM of the piston deposits and gave new facts on the absence of the role of diesel fuel in the deposit formation process. Most importantly, it opens the possibility of quickly performing the analysis of deposits with small amounts of samples while having a good separation of the volatiles.

Study of the Efficiency of the Hydroporation for Delivery of Plasmid DNA to the Cells on the Model of Toxic Neuropathy.

PubMed

Yudin, M A; Bykov, V N; Nikiforov, A S; Al-Shekhadat, R I; Ivanov, I M; Ustinova, T M

2018-04-01

We compared the efficiency of delivery of plasmid DNA (active ingredient concentration 1 mg/kg) that provides production of nerve growth factor (NGF) after intravenous administration to rats and after administration by hydroporation. The method of hydroporation ensured plasmid penetration into the liver tissue and lengthened the time of its detection in the organ. DNA concentration in 1 h after its introduction by hydroporation or intravenous route was 0.7 and 0.05 ng/mg tissue, respectively. The use of this transfection method ensured preservation of NGF DNA in the liver tissue at a level of 0.24 ng/mg of tissue 1 day after administration of the plasmid construct, while after intravenous administration, expression of the analyzed DNA was not detected in blood and liver samples. After hydroporation, the maximum of relative normalized expression of cDNA (270 rel. units) was observed after 4 h, and after 1 day, this parameter decreased to 35 rel. units. Introduction of plasmid DNA of NGF by hydroporation prevented the development of disorders of neuromuscular conduction in a rats model of toxic neuropathy induced by subacute administration of malathion in a dose of 0.5 LD 50 .

Measurement and Visualization of Mass Transport for the Flowing Atmospheric Pressure Afterglow (FAPA) Ambient Mass-Spectrometry Source

PubMed Central

Pfeuffer, Kevin P.; Ray, Steven J.; Hieftje, Gary M.

2014-01-01

Ambient desorption/ionization mass spectrometry (ADI-MS) has developed into an important analytical field over the last nine years. The ability to analyze samples under ambient conditions while retaining the sensitivity and specificity of mass spectrometry has led to numerous applications and a corresponding jump in the popularity of this field. Despite the great potential of ADI-MS, problems remain in the areas of ion identification and quantification. Difficulties with ion identification can be solved through modified instrumentation, including accurate-mass or MS/MS capabilities for analyte identification. More difficult problems include quantification due to the ambient nature of the sampling process. To characterize and improve sample volatilization, ionization, and introduction into the mass-spectrometer interface, a method of visualizing mass transport into the mass spectrometer is needed. Schlieren imaging is a well-established technique that renders small changes in refractive index visible. Here, schlieren imaging was used to visualize helium flow from a plasma-based ADI-MS source into a mass spectrometer while ion signals were recorded. Optimal sample positions for melting-point capillary and transmission-mode (stainless steel mesh) introduction were found to be near (within 1 mm of) the mass spectrometer inlet. Additionally, the orientation of the sampled surface plays a significant role. More efficient mass transport resulted for analyte deposits directly facing the MS inlet. Different surfaces (glass slide and rough surface) were also examined; for both it was found that the optimal position is immediately beneath the MS inlet. PMID:24658804

Measurement and visualization of mass transport for the flowing atmospheric pressure afterglow (FAPA) ambient mass-spectrometry source.

PubMed

Pfeuffer, Kevin P; Ray, Steven J; Hieftje, Gary M

2014-05-01

Ambient desorption/ionization mass spectrometry (ADI-MS) has developed into an important analytical field over the last 9 years. The ability to analyze samples under ambient conditions while retaining the sensitivity and specificity of mass spectrometry has led to numerous applications and a corresponding jump in the popularity of this field. Despite the great potential of ADI-MS, problems remain in the areas of ion identification and quantification. Difficulties with ion identification can be solved through modified instrumentation, including accurate-mass or MS/MS capabilities for analyte identification. More difficult problems include quantification because of the ambient nature of the sampling process. To characterize and improve sample volatilization, ionization, and introduction into the mass spectrometer interface, a method of visualizing mass transport into the mass spectrometer is needed. Schlieren imaging is a well-established technique that renders small changes in refractive index visible. Here, schlieren imaging was used to visualize helium flow from a plasma-based ADI-MS source into a mass spectrometer while ion signals were recorded. Optimal sample positions for melting-point capillary and transmission-mode (stainless steel mesh) introduction were found to be near (within 1 mm of) the mass spectrometer inlet. Additionally, the orientation of the sampled surface plays a significant role. More efficient mass transport resulted for analyte deposits directly facing the MS inlet. Different surfaces (glass slide and rough surface) were also examined; for both it was found that the optimal position is immediately beneath the MS inlet.

Measurement and Visualization of Mass Transport for the Flowing Atmospheric Pressure Afterglow (FAPA) Ambient Mass-Spectrometry Source

NASA Astrophysics Data System (ADS)

Pfeuffer, Kevin P.; Ray, Steven J.; Hieftje, Gary M.

2014-05-01

Ambient desorption/ionization mass spectrometry (ADI-MS) has developed into an important analytical field over the last 9 years. The ability to analyze samples under ambient conditions while retaining the sensitivity and specificity of mass spectrometry has led to numerous applications and a corresponding jump in the popularity of this field. Despite the great potential of ADI-MS, problems remain in the areas of ion identification and quantification. Difficulties with ion identification can be solved through modified instrumentation, including accurate-mass or MS/MS capabilities for analyte identification. More difficult problems include quantification because of the ambient nature of the sampling process. To characterize and improve sample volatilization, ionization, and introduction into the mass spectrometer interface, a method of visualizing mass transport into the mass spectrometer is needed. Schlieren imaging is a well-established technique that renders small changes in refractive index visible. Here, schlieren imaging was used to visualize helium flow from a plasma-based ADI-MS source into a mass spectrometer while ion signals were recorded. Optimal sample positions for melting-point capillary and transmission-mode (stainless steel mesh) introduction were found to be near (within 1 mm of) the mass spectrometer inlet. Additionally, the orientation of the sampled surface plays a significant role. More efficient mass transport resulted for analyte deposits directly facing the MS inlet. Different surfaces (glass slide and rough surface) were also examined; for both it was found that the optimal position is immediately beneath the MS inlet.

Comparative performance study of different sample introduction techniques for rapid and precise selenium isotope ratio determination using multi-collector inductively coupled plasma mass spectrometry (MC-ICP/MS).

PubMed

Elwaer, Nagmeddin; Hintelmann, Holger

2007-11-01

The analytical performance of five sample introduction systems, a cross flow nebulizer spray chamber, two different solvent desolvation systems, a multi-mode sample introduction system (MSIS), and a hydride generation (LI2) system were compared for the determination of Se isotope ratio measurements using multi-collector inductively coupled plasma mass spectrometry (MC-ICP/MS). The optimal operating parameters for obtaining the highest Se signal-to-noise (S/N) ratios and isotope ratio precision for each sample introduction were determined. The hydride generation (LI2) system was identified as the most suitable sample introduction method yielding maximum sensitivity and precision for Se isotope ratio measurement. It provided five times higher S/N ratios for all Se isotopes compared to the MSIS, 20 times the S/N ratios of both desolvation units, and 100 times the S/N ratios produced by the conventional spray chamber sample introduction method. The internal precision achieved for the (78)Se/(82)Se ratio at 100 ng mL(-1) Se with the spray chamber, two desolvation, MSIS, and the LI2 systems coupled to MC-ICP/MS was 150, 125, 114, 13, and 7 ppm, respectively. Instrument mass bias factors (K) were calculated using an exponential law correction function. Among the five studied sample introduction systems the LI2 showed the lowest mass bias of -0.0265 and the desolvation system showed the largest bias with -0.0321.

Variational Approach to Enhanced Sampling and Free Energy Calculations

NASA Astrophysics Data System (ADS)

Valsson, Omar; Parrinello, Michele

2014-08-01

The ability of widely used sampling methods, such as molecular dynamics or Monte Carlo simulations, to explore complex free energy landscapes is severely hampered by the presence of kinetic bottlenecks. A large number of solutions have been proposed to alleviate this problem. Many are based on the introduction of a bias potential which is a function of a small number of collective variables. However constructing such a bias is not simple. Here we introduce a functional of the bias potential and an associated variational principle. The bias that minimizes the functional relates in a simple way to the free energy surface. This variational principle can be turned into a practical, efficient, and flexible sampling method. A number of numerical examples are presented which include the determination of a three-dimensional free energy surface. We argue that, beside being numerically advantageous, our variational approach provides a convenient and novel standpoint for looking at the sampling problem.

Continuous Liquid-Sample Introduction for Bunsen Burner Atomic Emission Spectrometry.

ERIC Educational Resources Information Center

Smith, Gregory D.; And Others

1995-01-01

Describes a laboratory-constructed atomic emission spectrometer with modular instrumentation components and a simple Bunsen burner atomizer with continuous sample introduction. A schematic diagram and sample data are provided. (DDR)

Improving the electrocatalytic performance of carbon nanotubes for VO2+/VO2+ redox reaction by KOH activation

NASA Astrophysics Data System (ADS)

Dai, Lei; Jiang, Yingqiao; Meng, Wei; Zhou, Huizhu; Wang, Ling; He, Zhangxing

2017-04-01

In this paper, carbon nanotubes (CNTs) was activated by KOH treatment at high temperature and investigated as catalyst for VO2+/VO2+ redox reaction for vanadium redox flow battery (VRFB). X-ray photoelectron spectroscopy results suggest that the oxygen-containing groups can be introduced on CNTs by KOH activation. The mass transfer of vanadium ions can be accelerated by chemical etching by KOH activation and improved wettability due to the introduction of hydrophilic groups. The electrochemical properties of VO2+/VO2+ redox reaction can be enhanced by introduced oxygen-containing groups as active sites. The sample treated at 900 °C with KOH/CNTs mass ratio of 3:1 (CNTs-3) exhibits the highest electrocatalytic activity for VO2+/VO2+ redox reaction. The cell using CNTs-3 as positive catalyst demonstrates the smallest electrochemical polarization, the highest capacity and efficiency among the samples. Using KOH-activated CNTs-3 can increase the average energy efficiency of the cell by 4.4%. This work suggests that KOH-activated CNTs is a low-cost, efficient and promising catalyst for VO2+/VO2+ redox reaction for VRFB system.

Method and apparatus for transport, introduction, atomization and excitation of emission spectrum for quantitative analysis of high temperature gas sample streams containing vapor and particulates without degradation of sample stream temperature

DOEpatents

Eckels, David E.; Hass, William J.

1989-05-30

A sample transport, sample introduction, and flame excitation system for spectrometric analysis of high temperature gas streams which eliminates degradation of the sample stream by condensation losses.

Photocatalytic Performance of a Novel MOF/BiFeO₃ Composite.

PubMed

Si, Yunhui; Li, Yayun; Zou, Jizhao; Xiong, Xinbo; Zeng, Xierong; Zhou, Ji

2017-10-10

In this study, MOF/BiFeO₃ composite (MOF, metal-organic framework) has been synthesized successfully through a one-pot hydrothermal method. The MOF/BiFeO₃ composite samples, pure MOF samples and BiFeO₃ samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and by UV-vis spectrophotometry. The results and analysis reveal that MOF/BiFeO₃ composite has better photocatalytic behavior for methylene blue (MB) compared to pure MOF and pure BiFeO₃. The enhancement of photocatalytic performance should be due to the introduction of MOF change the surface morphology of BiFeO 3, which will increase the contact area with MB. This composing strategy of MOF/BiFeO₃ composite may bring new insight into the designing of highly efficient photocatalysts.

Externally pressurized porous cylinder for multiple surface aerosol generation and method of generation

DOEpatents

Apel, C.T.; Layman, L.R.; Gallimore, D.L.

1988-05-10

A nebulizer is described for generating aerosol having small droplet sizes and high efficiency at low sample introduction rates. The nebulizer has a cylindrical gas permeable active surface. A sleeve is disposed around the cylinder and gas is provided from the sleeve to the interior of the cylinder formed by the active surface. In operation, a liquid is provided to the inside of the gas permeable surface. The gas contacts the wetted surface and forms small bubbles which burst to form an aerosol. Those bubbles which are large are carried by momentum to another part of the cylinder where they are renebulized. This process continues until the entire sample is nebulized into aerosol sized droplets. 2 figs.

Concentration and separation of biological organisms by ultrafiltration and dielectrophoresis

DOEpatents

Simmons, Blake A.; Hill, Vincent R.; Fintschenko, Yolanda; Cummings, Eric B.

2010-10-12

Disclosed is a method for monitoring sources of public water supply for a variety of pathogens by using a combination of ultrafiltration techniques together dielectrophoretic separation techniques. Because water-borne pathogens, whether present due to "natural" contamination or intentional introduction, would likely be present in drinking water at low concentrations when samples are collected for monitoring or outbreak investigations, an approach is needed to quickly and efficiently concentrate and separate particles such as viruses, bacteria, and parasites in large volumes of water (e.g., 100 L or more) while simultaneously reducing the sample volume to levels sufficient for detecting low concentrations of microbes (e.g., <10 mL). The technique is also designed to screen the separated microbes based on specific conductivity and size.

Introduction of agarose gel as a green membrane in electromembrane extraction: An efficient procedure for the extraction of basic drugs with a wide range of polarities.

PubMed

Tabani, Hadi; Asadi, Sakine; Nojavan, Saeed; Parsa, Mitra

2017-05-12

Developing green methods for analyte extraction is one of the most important topics in the field of sample preparation. In this study, for the first time, agarose gel was used as membrane in electromembrane extraction (EME) without using any organic solvent, for the extraction of four model basic drugs (rivastigmine (RIV), verapamil (VER), amlodipine (AML), and morphine (MOR)) with a wide polarity window (log P from 0.43 to 3.7). Different variables playing vital roles in the proposed method were evaluated and optimized. As a driving force, a 25V electrical field was applied to make the analyte migrate from sample solution with pH 7.0, through the agarose gel 3% (w/v) with 5mm thickness, into an acceptor phase (AP) with pH 2.0. The best extraction efficiency was obtained with an extraction duration of 25min. With this new methodology, MOR with high polarity (log P=0.43) was efficiently extracted without using any carrier or ion pair reagents. Limits of detection (LODs) and quantification (LOQs) were in the ranges of 1.5-1.8ngmL -1 and 5.0-6.0ngmL -1 , respectively. Finally, the proposed method was successfully applied to determine concentrations of the model drugs in the wastewater sample. Copyright © 2017 Elsevier B.V. All rights reserved.

Fundamental and Applied Investigations in Atomic Spectrometric Analysis

NASA Astrophysics Data System (ADS)

Wu, Min

Simultaneous laser-excited fluorescence and absorption measurements were performed and the results have revealed that any interference caused by easily ionized elements does not originate from variations in analyte emission (quantum) efficiency. A closely related area, the roles of wet and dry aerosols in the matrix interference are clarified through spatially resolved imaging of the plasma by a charged coupled device camera. To eliminate matrix interference effects practically, various methods have been developed based on the above studies. The use of column pre-concentration with flow injection analysis has been found to provide a simple solution for reducing interference effects and increasing sensitivity of elemental analysis. A novel mini-spray chamber was invented. The new vertical rotary spray chamber combines gravitational, centrifugal, turbulent, and impact droplet segregation mechanisms to achieve a higher efficiency of small-droplet formation in a nebulized sample spray. As a result, it offers also higher sample-transport efficiency, lower memory effects, and improved analytical figures of merit over existing devices. This new device was employed with flow injection analysis to simulate an interface for coupling high performance liquid chromatography (HPLC) to a microwave plasma for chromatographic detection. The detection limits for common metallic elements are in the range of 5-50 mug/mL, and are degraded only twofold when the elements are presented in an organic solvent such as ethanol or methanol. Other sample-introduction schemes have also been investigated to improve sample-introduction technology. The direct coupling of hydride-generation techniques to the helium microwave plasma torch was evaluated for the determination of arsenic, antimony and tin by atomic emission spectrometry. A manually controlled peristaltic pump was modified for computer control and continuous flow injection was evaluated for standard calibration and trace elemental analysis. The present work evaluates the coupling of a novel microwave plasma torch with a quadruple mass spectrometer for the detection of ionic species from different nonmetals. Initial work performed with such a combination is demonstrated to be not only practicable but also promising. Detection limits for the halogens (F, Cl, Br, I) and S are in the range between 10 ng/mL and 1mug/mL. Further improvements have been realized through the use of chemical -vapor generation and by optimization of the plasma and the mass spectrometer. (Abstract shortened by UMI.).

Ion Clouds in the Inductively Coupled Plasma Torch: A Closer Look through Computations.

PubMed

Aghaei, Maryam; Lindner, Helmut; Bogaerts, Annemie

2016-08-16

We have computationally investigated the introduction of copper elemental particles in an inductively coupled plasma torch connected to a sampling cone, including for the first time the ionization of the sample. The sample is inserted as liquid particles, which are followed inside the entire torch, i.e., from the injector inlet up to the ionization and reaching the sampler. The spatial position of the ion clouds inside the torch as well as detailed information on the copper species fluxes at the position of the sampler orifice and the exhausts of the torch are provided. The effect of on- and off-axis injection is studied. We clearly show that the ion clouds of on-axis injected material are located closer to the sampler with less radial diffusion. This guarantees a higher transport efficiency through the sampler cone. Moreover, our model reveals the optimum ranges of applied power and flow rates, which ensure the proper position of ion clouds inside the torch, i.e., close enough to the sampler to increase the fraction that can enter the mass spectrometer and with minimum loss of material toward the exhausts as well as a sufficiently high plasma temperature for efficient ionization.

Reconstructed plutonium fallout in the GV7 firn core from Northern Victoria Land, East Antarctica

NASA Astrophysics Data System (ADS)

Hwang, H.; Han, Y.; Kang, J.; Lee, K.; Hong, S.; Hur, S. D.; Narcisi, B.; Frezzotti, M.

2017-12-01

Atmospheric nuclear explosions during the period from the 1940s to the 1980s are the major anthropogenic source of plutonium (Pu) in the environment. In this work, we analyzed fg g-1 levels of artificial Pu, released predominantly by atmospheric nuclear weapons tests. We measured 351 samples which collected a 78 m-depth fire core at the site of GV7 (S 70°41'17.1", E 158°51'48.9", 1950 m a.s.l.), Northern Victoria Land, East Antarctica. To determine the Pu concentration in the samples, we used an inductively coupled plasma sector field mass spectrometry coupled with an Apex high-efficiency sample introduction system, which has the advantages of small sample consumption and simple sample preparation. We reconstructed the firn core Pu fallout record for the period after 1954 CE shows a significant fluctuation in agreement with past atmospheric nuclear testing. These data will contribute to ice core research by providing depth-age information.

High-pressure liquid chromatography with direct injection of gas sample.

PubMed

Astanin, Anton I; Baram, Grigory I

2017-06-09

The conventional method of using liquid chromatography to determine the composition of a gaseous mixture entails dissolving vapors in a suitable solvent, then obtaining a chromatograph of the resulting solution. We studied the direct introduction of a gaseous sample into a C18 reversed-phase column, followed by separation of the components by HPLC with UV detection. Since the chromatography was performed at high pressure, vapors readily dissolved in the eluent and the substances separated in the column as effectively as in liquid samples. Samples were injected into the column in two ways: a) through the valve without a flow stop; b) after stopping the flow and relieving all pressure. We showed that an injectable gas volume could reach 70% of column dead volume. When an injected gaseous sample volume was less than 10% of the column dead volume, the resulting peaks were symmetrical and the column efficiency was high. Copyright © 2017 Elsevier B.V. All rights reserved.

Sample introduction apparatus for a flow cytometer

DOEpatents

Van den Engh, Ger

1998-01-01

A sample introduction system for a flow cytometer allows easy change of sample containers such as test tubes and facilitates use in high pressure environments. The sample container includes a cap having a pressure supply chamber and a sample container attachment cavity. A sample container may be automatically positioned into the attachment cavity so as to sealably engage the end of the sample container as its outer surface. This positioning may be accomplished through some sample introduction mechanism. To facilitate cleaning HPLC tubing and fittings may be used in a manner which facilitates removable of the entire tubing from both the nozzle container and other sample container cap to permit its replacement to avoid contamination. The sample container support may include horizontal stops which loosely limit the movement of the sample container and thus avoid further stresses upon it.

Sample introduction system for a flow cytometer

DOEpatents

Van den Engh, Ger

1997-01-01

A sample introduction system for a flow cytometer allows easy change of sample containers such as test tubes and facilitates use in high pressure environments. The sample container includes a cap having a pressure supply chamber and a sample container attachment cavity. A sample container may be automatically positioned into the attachment cavity so as to sealably engage the end of the sample container as its outer surface. This positioning may be accomplished through some sample introduction mechanism. To facilitate cleaning, HPLC tubing and fittings may be used in a manner which facilitates removing of the entire tubing from both the nozzle container and other sample container cap to permit its replacement to avoid contamination. The sample container support may include horizontal stops which loosely limit the movement of the sample container and thus avoid further stresses upon it.

Sample introduction apparatus for a flow cytometer

DOEpatents

Van den Engh, G.

1998-03-10

A sample introduction system for a flow cytometer allows easy change of sample containers such as test tubes and facilitates use in high pressure environments. The sample container includes a cap having a pressure supply chamber and a sample container attachment cavity. A sample container may be automatically positioned into the attachment cavity so as to sealably engage the end of the sample container as its outer surface. This positioning may be accomplished through some sample introduction mechanism. To facilitate cleaning HPLC tubing and fittings may be used in a manner which facilitates removable of the entire tubing from both the nozzle container and other sample container cap to permit its replacement to avoid contamination. The sample container support may include horizontal stops which loosely limit the movement of the sample container and thus avoid further stresses upon it. 3 figs.

Sample introduction system for a flow cytometer

DOEpatents

Engh, G. van den

1997-02-11

A sample introduction system for a flow cytometer allows easy change of sample containers such as test tubes and facilitates use in high pressure environments. The sample container includes a cap having a pressure supply chamber and a sample container attachment cavity. A sample container may be automatically positioned into the attachment cavity so as to sealably engage the end of the sample container as its outer surface. This positioning may be accomplished through some sample introduction mechanism. To facilitate cleaning, HPLC tubing and fittings may be used in a manner which facilitates removing of the entire tubing from both the nozzle container and other sample container cap to permit its replacement to avoid contamination. The sample container support may include horizontal stops which loosely limit the movement of the sample container and thus avoid further stresses upon it. 3 figs.

Surveillance of low pathogenic novel H7N9 avian influenza in commercial poultry barns: detection of outbreaks and estimation of virus introduction time.

PubMed

Pinsent, Amy; Blake, Isobel M; White, Michael T; Riley, Steven

2014-08-01

Both high and low pathogenic subtype A avian influenza remain ongoing threats to the commercial poultry industry globally. The emergence of a novel low pathogenic H7N9 lineage in China presents itself as a new concern to both human and animal health and may necessitate additional surveillance in commercial poultry operations in affected regions. Sampling data was simulated using a mechanistic model of H7N9 influenza transmission within commercial poultry barns together with a stochastic observation process. Parameters were estimated using maximum likelihood. We assessed the probability of detecting an outbreak at time of slaughter using both real-time polymerase chain reaction (rt-PCR) and a hemagglutinin inhibition assay (HI assay) before considering more intense sampling prior to slaughter. The day of virus introduction and R0 were estimated jointly from weekly flock sampling data. For scenarios where R0 was known, we estimated the day of virus introduction into a barn under different sampling frequencies. If birds were tested at time of slaughter, there was a higher probability of detecting evidence of an outbreak using an HI assay compared to rt-PCR, except when the virus was introduced <2 weeks before time of slaughter. Prior to the initial detection of infection N sample = 50 (1%) of birds were sampled on a weekly basis once, but after infection was detected, N sample = 2000 birds (40%) were sampled to estimate both parameters. We accurately estimated the day of virus introduction in isolation with weekly and 2-weekly sampling. A strong sampling effort would be required to infer both the day of virus introduction and R0. Such a sampling effort would not be required to estimate the day of virus introduction alone once R0 was known, and sampling N sample = 50 of birds in the flock on a weekly or 2 weekly basis would be sufficient.

Transfer pricing in hospitals and efficiency of physicians: the case of anesthesia services.

PubMed

Kuntz, Ludwig; Vera, Antonio

2005-01-01

The objective is to investigate theoretically and empirically how the efficiency of the physicians involved in anesthesia and surgery can be optimized by the introduction of transfer pricing for anesthesia services. The anesthesiology data of approximately 57,000 operations carried out at the University Hospital Hamburg-Eppendorf (UKE) in Germany in the period from 2000 to 2002 are analyzed using parametric and non-parametric methods. The principal finding of the empirical analysis is that the efficiency of the physicians involved in anesthesia and surgery at the UKE improved after the introduction of transfer pricing.

From laboratory to point of entry: development and implementation of a loop-mediated isothermal amplification (LAMP)-based genetic identification system to prevent introduction of quarantine insect species.

PubMed

Blaser, Simon; Diem, Hanspeter; von Felten, Andreas; Gueuning, Morgan; Andreou, Michael; Boonham, Neil; Tomlinson, Jennifer; Müller, Pie; Utzinger, Jürg; Frey, Jürg E; Bühlmann, Andreas

2018-06-01

Rapid genetic on-site identification methods at points of entry, such as seaports and airports, have the potential to become important tools to prevent the introduction and spread of economically harmful pest species that are unintentionally transported by the global trade of plant commodities. This paper reports the development and evaluation of a loop-mediated isothermal amplification (LAMP)-based identification system to prevent introduction of the three most frequently encountered regulated quarantine insect species groups at Swiss borders, Bemisia tabaci, Thrips palmi and several regulated fruit flies of the genera Bactrocera and Zeugodacus. The LAMP primers were designed to target a fragment of the mitochondrial cytochrome c oxidase subunit I gene and were generated based on publicly available DNA sequences. Laboratory evaluations analysing 282 insect specimens suspected to be quarantine organisms revealed an overall test efficiency of 99%. Additional on-site evaluation at a point of entry using 37 specimens performed by plant health inspectors with minimal laboratory training resulted in an overall test efficiency of 95%. During both evaluation rounds, there were no false-positives and the observed false-negatives were attributable to human-induced manipulation errors. To overcome the possibility of accidental introduction of pests as a result of rare false-negative results, samples yielding negative results in the LAMP method were also subjected to DNA barcoding. Our LAMP assays reliably differentiated between the tested regulated and non-regulated insect species within <1 h. Hence, LAMP assays represent suitable tools for rapid on-site identification of harmful pests, which might facilitate an accelerated import control process for plant commodities. © 2018 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. © 2018 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Determination of Caffeine and Other Purine Compounds in Food and Pharmaceuitcals by Micellar Electrokinetic Chrmoatography

NASA Astrophysics Data System (ADS)

Vogt, Carla; Contradi, S.; Rohde, E.

1997-09-01

Capillary elctrophoresis is a modern separation technique, especially the extremely high efficiencies and minimal requirements with regard to buffers, samples and solvents lead to a dramatic increase of applications in the last few years. This paper offers an introduction to the technique of micellar elektrokinetic chromatography as a special kind of capillary electrophoresis. Caffeine and other purine compounds have been determined in foodstuff (tea, coffee, cocoa) as well as in pharmaceutical formulations. Different sample preparation procedures which have been developed with regard to the special properties of the sample matrices are discussed in the paper.This preparation facilitates the separation in many cases. So students have to solve a relatively simple separation problem by variation of buffer pH, buffer components and separation parameters. By doing a calibration for the analyzed purine compounds they will learn about reproducibility in capillary electrophoresis.

Teaching graphics in technical communication classes

NASA Technical Reports Server (NTRS)

Spurgeon, K. C.

1981-01-01

Graphic aids convey and clarify information more efficiently and accurately than words alone therefore, most technical writing includes the use of graphics. Ways of accumulating and presenting graphics illustrations on a shoestring budget are suggested. These include collecting graphics from companies, annual reports and laminating them for workshop use or putting them on a flip chart for classroom presentation, creating overhead transparencies to demonstrate different levels of effectiveness of graphic aids, and bringing in grahic artists for question/answer periods or in class workshops. Also included are an extensive handout as an introduction to graphics, sample assignments, and a selected and annotated bibliography.

Method for concentration and separation of biological organisms by ultrafiltration and dielectrophoresis

DOEpatents

Simmons, Blake A.; Hill, Vincent R.; Fintschenko, Yolanda; Cummings, Eric B.

2012-09-04

Disclosed is a method for monitoring sources of public water supply for a variety of pathogens by using a combination of ultrafiltration techniques together dielectrophoretic separation techniques. Because water-borne pathogens, whether present due to "natural" contamination or intentional introduction, would likely be present in drinking water at low concentrations when samples are collected for monitoring or outbreak investigations, an approach is needed to quickly and efficiently concentrate and separate particles such as viruses, bacteria, and parasites in large volumes of water (e.g., 100 L or more) while simultaneously reducing the sample volume to levels sufficient for detecting low concentrations of microbes (e.g., <10 mL). The technique is also designed to screen the separated microbes based on specific conductivity and size.

Applications of inductively coupled plasma-mass spectrometry in environmental radiochemistry

USGS Publications Warehouse

Grain, J.S.

1996-01-01

The state of the art in ICP-MS is now such that there are few discernible differences between radiochemical and mass spectrometric determinations of longlived radionuclides. Indeed, ICP-MS may provide better (more sensitive) data for many radionuclides, depending upon how one wishes to define "long-lived." In lowlevel determinations, sample preparation remains an important part of the analytical procedure, even with ICP-MS, but the speed and isotopic selectivity of the mass spectrometer appear to offer distinct procedural advantages over radiochemical techniques. Therefore, "radioanalytical" ICP-MS applications should continue to grow, especially in the area of radiation protection, but further research (on efficient sample introduction, for example) and method development may be required to get ICP-MS "off the ground" in the geochemical research areas that have traditionally been supported by radiochemistry.

Evaluation of Mediterranean Agricultural Residues as a Potential Feedstock for the Production of Biogas via Anaerobic Fermentation.

PubMed

Nitsos, Christos; Matsakas, Leonidas; Triantafyllidis, Kostas; Rova, Ulrika; Christakopoulos, Paul

2015-01-01

Hydrothermal, dilute acid, and steam explosion pretreatment methods, were evaluated for their efficiency to improve the methane production yield of three Mediterranean agricultural lignocellulosic residues such as olive tree pruning, grapevine pruning, and almond shells. Hydrothermal and dilute acid pretreatments provided low to moderate increase in the digestibility of the biomass samples, whereas steam explosion enabled the highest methane yields to be achieved for almond shells at 232.2 ± 13.0 mL CH4/gVS and olive pruning at 315.4 ± 0.0 mL CH4/gVS. Introduction of an enzymatic prehydrolysis step moderately improved methane yields for hydrothermal and dilute acid pretreated samples but not for the steam exploded ones.

Evaluation of Mediterranean Agricultural Residues as a Potential Feedstock for the Production of Biogas via Anaerobic Fermentation

PubMed Central

Nitsos, Christos; Triantafyllidis, Kostas

2015-01-01

Hydrothermal, dilute acid, and steam explosion pretreatment methods, were evaluated for their efficiency to improve the methane production yield of three Mediterranean agricultural lignocellulosic residues such as olive tree pruning, grapevine pruning, and almond shells. Hydrothermal and dilute acid pretreatments provided low to moderate increase in the digestibility of the biomass samples, whereas steam explosion enabled the highest methane yields to be achieved for almond shells at 232.2 ± 13.0 mL CH4/gVS and olive pruning at 315.4 ± 0.0 mL CH4/gVS. Introduction of an enzymatic prehydrolysis step moderately improved methane yields for hydrothermal and dilute acid pretreated samples but not for the steam exploded ones. PMID:26609521

Evaluation of the cost-effectiveness of bovine brucellosis surveillance in a disease-free country using stochastic scenario tree modelling.

PubMed

Hénaux, Viviane; Calavas, Didier

2017-01-01

Surveillance systems of exotic infectious diseases aim to ensure transparency about the country-specific animal disease situation (i.e. demonstrate disease freedom) and to identify any introductions. In a context of decreasing resources, evaluation of surveillance efficiency is essential to help stakeholders make relevant decisions about prioritization of measures and funding allocation. This study evaluated the efficiency (sensitivity related to cost) of the French bovine brucellosis surveillance system using stochastic scenario tree models. Cattle herds were categorized into three risk groups based on the annual number of purchases, given that trading is considered as the main route of brucellosis introduction in cattle herds. The sensitivity in detecting the disease and the costs of the current surveillance system, which includes clinical (abortion) surveillance, programmed serological testing and introduction controls, were compared to those of 19 alternative surveillance scenarios. Surveillance costs included veterinary fees and laboratory analyses. The sensitivity over a year of the current surveillance system was predicted to be 91±7% at a design prevalence of 0.01% for a total cost of 14.9±1.8 million €. Several alternative surveillance scenarios, based on clinical surveillance and random or risk-based serological screening in a sample (20%) of the population, were predicted to be at least as sensitive but for a lower cost. Such changes would reduce whole surveillance costs by 20 to 61% annually, and the costs for farmers only would be decreased from about 12.0 million € presently to 5.3-9.0 million € (i.e. 25-56% decrease). Besides, fostering the evolution of the surveillance system in one of these directions would be in agreement with the European regulations and farmers perceptions on brucellosis risk and surveillance.

Evaluation of the cost-effectiveness of bovine brucellosis surveillance in a disease-free country using stochastic scenario tree modelling

PubMed Central

Calavas, Didier

2017-01-01

Surveillance systems of exotic infectious diseases aim to ensure transparency about the country-specific animal disease situation (i.e. demonstrate disease freedom) and to identify any introductions. In a context of decreasing resources, evaluation of surveillance efficiency is essential to help stakeholders make relevant decisions about prioritization of measures and funding allocation. This study evaluated the efficiency (sensitivity related to cost) of the French bovine brucellosis surveillance system using stochastic scenario tree models. Cattle herds were categorized into three risk groups based on the annual number of purchases, given that trading is considered as the main route of brucellosis introduction in cattle herds. The sensitivity in detecting the disease and the costs of the current surveillance system, which includes clinical (abortion) surveillance, programmed serological testing and introduction controls, were compared to those of 19 alternative surveillance scenarios. Surveillance costs included veterinary fees and laboratory analyses. The sensitivity over a year of the current surveillance system was predicted to be 91±7% at a design prevalence of 0.01% for a total cost of 14.9±1.8 million €. Several alternative surveillance scenarios, based on clinical surveillance and random or risk-based serological screening in a sample (20%) of the population, were predicted to be at least as sensitive but for a lower cost. Such changes would reduce whole surveillance costs by 20 to 61% annually, and the costs for farmers only would be decreased from about 12.0 million € presently to 5.3–9.0 million € (i.e. 25–56% decrease). Besides, fostering the evolution of the surveillance system in one of these directions would be in agreement with the European regulations and farmers perceptions on brucellosis risk and surveillance. PMID:28859107

A Study on the Effect on Scheduling and Management of Surgeries with the Introduction of Excellent Medical Information.

PubMed

Mei, Tsai Ching

2016-01-01

The services of OR play an important role in the medical business for department of surgery. The most important issue for OR is about the scheduling and management of surgeries. Good surgery schedule could elevate the utilization efficiency of OR. Therefore, the introduction of excellent medical information can both dramatically elevate the work efficiency of health care employees and reduce workload to reach win-win benefits in both management and performance.

Ozone Modulation/Membrane Introduction Mass Spectrometry for Analysis of Hydrocarbon Pollutants in Air

NASA Astrophysics Data System (ADS)

Atkinson, D. B.

2001-12-01

Modulation of volatile hydrocarbons in two-component mixtures is demonstrated using an ozonolysis pretreatment with membrane introduction mass spectrometry (MIMS). The MIMS technique allows selective introduction of volatile and semivolatile analytes into a mass spectrometer via processes known collectively as pervaporation [Kotiaho and Cooks, 1992]. A semipermeable polymer membrane acts as an interface between the sample (vapor or solution) and the vacuum of the mass spectrometer. This technique has been demonstrated to allow for sensitive analysis of hydrocarbons and other non-polar volatile organic compounds (VOC`s) in air samples[Cisper et al., 1995] . The methodology has the advantages of no sample pretreatment and short analysis time, which are promising for online monitoring applications but the chief disadvantage of lack of a separation step for the different analytes in a mixture. Several approaches have been investigated to overcome this problem including use of selective chemical ionization [Bier and Cooks, 1987] and multivariate calibration techniques[Ketola et al., 1999] . A new approach is reported for the quantitative measurement of VOCs in complex matrices. The method seeks to reduce the complexity of mass spectra observed in hydrocarbon mixture analysis by selective pretreatment of the analyte mixture. In the current investigation, the rapid reaction of ozone with alkenes is used, producing oxygenated compounds which are suppressed by the MIMS system. This has the effect of removing signals due to unsaturated analytes from the compound mass spectra, and comparison of the spectra before and after the ozone treatment reveals the nature of the parent compounds. In preliminary investigations, ozone reacted completely with cyclohexene from a mixture of cylohexene and cyclohexane, and with β -pinene from a mixture of toluene and β -pinene, suppressing the ion signals from the olefins. A slight attenuation of the cyclohexane and toluene in those mixtures was also observed. Despite this problem, the hydrocarbon signal response can be calibrated and the method can be used for quantitative analysis of volatile hydrocarbon compounds in air samples. This methodology should augment the efficiency of the MIMS approach in online and onsite monitoring of VOC emissions. Bier, M.R., and R.G. Cooks, Membrane Interface for Selective Introduction of Volatile Compounds Directly into The Ionization Chamber of a Mass Spectrometer, Anal. Chem., 59 (4), 597, 1987. Cisper, M.E., C.G. Gill, L.E. Townsend, and P.H. Hemberger, On-Line Detection of Volatile Organic Compounds in Air at Parts-per-Trillion Levels by Membrane Introduction Mass Spectrometry, Anal. Chem., 67 (8), 1413-1417, 1995. Ketola, R.A., M. Ojala, and J. Heikkonen, A Non-linear Asymmetric Error Function-based Least Mean Square Approach for the Analysis of Multicomponent Mass Spectra Measured by Membrane Inlet Mass Spectrometry, Rapid Commun. Mass Spectrom., 13 (8), 654, 1999. Kotiaho, T., and R.G. Cooks, Membrane Introduction Mass Spectrometry in Environmental Analysis, in: J.J. Breen, M. J. Dellarco, (Eds), Pollution in Industrial processes, 126 pp., ACS Symp. Ser., Washington, D.C. 508, 1992.

From fresh heterologous oocyte donation to autologous oocyte banking

PubMed Central

Stoop, D.

2012-01-01

Introduction: Today, oocyte donation has become well established, giving rise to thousands of children born worldwide annually. The introduction of oocyte cryopreservation through vitrification allows the introduction of egg banking, improving the efficiency and comfort of oocyte donation. Moreover, the vitrification technique can now enable autologous donation of oocytes to prevent future infertility. Methods: We evaluated fresh heterologous oocyte donation in terms of obstetrical and perinatal outcome as well as of the reproductive outcome of past donors. We then evaluated the efficiency of a closed vitrification device and its clinical applications within ART. Thirdly, we evaluated the opinion of women with regard to preventive egg freezing and the efficiency of a human oocyte in relation to age. Results: Oocyte donation is associated with an increased risk of first trimester bleeding and pregnancy induced hypertension. Donating oocytes does not seem to increase the likelihood for a later need of fertility treatment. The chance of an oocyte to result in live birth (utilization rate) in women <37 years old remains constant with a mean of 4.47%. A significant proportion of young women would consider safeguarding their reproductive potential through egg freezing or are at least open to the idea. Discussion and Conclusion: The introduction of efficient oocyte cryopreservation has revolutionized oocyte donation through the establishment of eggbank donation. The technique also enables women to perform autologous donation after preventive oocyte storage in order to circumvent their biological clock. PMID:24753920

Organophosphate flame retardants in household dust before and after introduction of new furniture.

PubMed

Keimowitz, A R; Strunsky, N; Wovkulich, K

2016-04-01

Flame retardant compounds originating from household items collect in household dust, a reasonable proxy for human exposure. Contributions of specific items or behaviors to dust are difficult to separate. This study examined standardized college housing before and after the introduction of new, flame retardant couches in order to explore any effect that changing upholstered furniture may have on flame retardant concentrations in dust. Two contradictory hypotheses were posited: (1) that new furniture might increase flame retardant releases immediately after introduction due to initial off-gassing of new materials or (2) that older furniture would release more flame retardants due to mechanical breakdown of polyurethane foam. This study was designed to determine which of these processes dominated. Prior to the introduction of new furniture, TDCIPP was detected in 12/20 samples at a median concentration of 22 μg/g and TCEP was detected in 1/20 samples at a concentration of 16 μg/g. TDCIPP and TCEP were not detected in any samples (N = 29) after the introduction of new couches. TPHP was detected both before (in 11/20 samples) and after (in 5/29 samples) introduction of new couches; the median concentrations before and after were 63 ± 49 and 16 ± 11 μg/g (standard deviation shown). Introduced couches contained TDCIPP (and not TPHP) at ∼1.25% (w/w). These data support the second hypothesis and indicate that removal of older furniture decreases TDCIPP and TCEP concentrations in dust and may potentially reduce total flame retardant concentrations in dust, at least immediately after introduction of the new furniture. Copyright © 2016 Elsevier Ltd. All rights reserved.

Pressure-assisted introduction of urine samples into a short capillary for electrophoretic separation with contactless conductivity and UV spectrometry detection.

PubMed

Makrlíková, Anna; Opekar, František; Tůma, Petr

2015-08-01

A computer-controlled hydrodynamic sample introduction method has been proposed for short-capillary electrophoresis. In the method, the BGE flushes sample from the loop of a six-way sampling valve and is carried to the injection end of the capillary. A short pressure impulse is generated in the electrolyte stream at the time when the sample zone is at the capillary, leading to injection of the sample into the capillary. Then the electrolyte flow is stopped and the separation voltage is turned on. This way of sample introduction does not involve movement of the capillary and both of its ends remain constantly in the solution during both sample injection and separation. The amount of sample introduced to the capillary is controlled by the duration of the pressure pulse. The new sample introduction method was tested in the determination of ammonia, creatinine, uric acid, and hippuric acid in human urine. The determination was performed in a capillary with an overall length of 10.5 cm, in two BGEs with compositions 50 mM MES + 5 mM NaOH (pH 5.1) and 1 M acetic acid + 1.5 mM crown ether 18-crown-6 (pH 2.4). A dual contactless conductivity/UV spectrometric detector was used for the detection. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The effect of different thickness alumina capping layers on the final morphology of dewet thin Ni films

NASA Astrophysics Data System (ADS)

White, Benjamin C.; Behbahanian, Amir; Stoker, T. McKay; Fowlkes, Jason D.; Hartnett, Chris; Rack, Phillip D.; Roberts, Nicholas A.

2018-03-01

Nanoparticles on a substrate have numerous applications in nanotechnology, from enhancements to solar cell efficiency to improvements in carbon nanotube growth. Producing nanoparticles in a cost effective fashion with control over size and spacing is desired, but difficult to do. This work presents a scalable method for altering the radius and pitch distributions of nickel nanoparticles. The introduction of alumina capping layers to thin nickel films during a pulsed laser-induced dewetting process has yielded reductions in the mean and standard deviation of radii and pitch for dewet nanoparticles with no noticeable difference in final morphology with increased capping layer thickness. The differences in carbon nanotube mats grown, on the uncapped sample and one of the capped samples, is also presented here, with a more dense mat being present for the capped case.

Difference in leaf water use efficiency/photosynthetic nitrogen use efficiency of Bt-cotton and its conventional peer.

PubMed

Guo, Ruqing; Sun, Shucun; Liu, Biao

2016-09-15

This study is to test the effects of Bt gene introduction on the foliar water/nitrogen use efficiency in cotton. We measured leaf stomatal conductance, photosynthetic rate, and transpiration rate under light saturation condition at different stages of a conventional cultivar (zhongmian no. 16) and its counterpart Bt cultivar (zhongmian no. 30) that were cultured on three levels of fertilization, based on which leaf instantaneous water use efficiency was derived. Leaf nitrogen concentration was measured to calculate leaf photosynthetic nitrogen use efficiency, and leaf δ(13)C was used to characterize long term water use efficiency. Bt cultivar was found to have lower stomatal conductance, net photosynthetic rates and transpiration rates, but higher instantaneous and long time water use efficiency. In addition, foliar nitrogen concentration was found to be higher but net photosynthetic rate was lower in the mature leaves of Bt cultivar, which led to lower photosynthetic nitrogen use efficiency. This might result from the significant decrease of photosynthetic rate due to the decrease of stomatal conductance. In conclusion, our findings show that the introduction of Bt gene should significantly increase foliar water use efficiency but decrease leaf nitrogen use efficiency in cotton under no selective pressure.

The Efficiency and Effectiveness of Teaching in Higher Education.

ERIC Educational Resources Information Center

Piper, David Warren, Ed.

Twenty papers originally presented at a conference organized by London University on "Efficiency in Teaching Methods in Higher Education" are presented. After an introduction by David Warren Piper, the following papers are included: "Old Prejudices and New Management Tools" (Gerald Fowler); "Efficiency in Higher…

Estimation of the efficiency of the introduction of a porous layer into a silicon-on-sapphire structure substrate to enhance the reliability of devices under irradiation

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

Aleksandrov, P. A., E-mail: Alexandrov-PA@nrcki.ru; Baranova, E. K.; Budaragin, V. V.

2016-08-15

We investigate the efficiency of the introduction of a porous layer into the substrate of a silicon-onsapphire structure by the implantation of He ions to enhance the radiation resistance of devices. The properties of the introduced layer and its parameters affecting the concentration of minority charge carriers generated by irradiation are analyzed. The reported results of the analysis and calculations can be used to optimize He-ion implantation conditions during the formation of a porous layer.

The Independence and Interdependence of Coacting Observers in Regard to Performance Efficiency, Workload, and Stress in a Vigilance Task

DTIC Science & Technology

2016-09-01

independence/ dependence , evaluation apprehension, workload, stress 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT: SAR 18. NUMBER...indepen- dence/ dependence , evaluation apprehension, workload, stress IntroductIon Vigilance or sustained attention tasks require observers to maintain

Mechanism of introduction of exogenous genes into cultured cells using DEAE-dextran-MMA graft copolymer as non-viral gene carrier.

PubMed

Eshita, Yuki; Higashihara, Junko; Onishi, Masayasu; Mizuno, Masaaki; Yoshida, Jun; Takasaki, Tomohiko; Kubota, Naoji; Onishi, Yasuhiko

2009-07-23

Comparative investigations were carried out regarding the efficiency of introduction of exogenous genes into cultured cells using a cationic polysaccharide DEAE-dextran-MMA (methyl methacrylate ester) graft copolymer (2-diethylaminoethyl-dextran-methyl methacrylate graft copolymer; DDMC) as a nonviral carrier for gene introduction. The results confirmed that the gene introduction efficiency was improved with DDMC relative to DEAE-dextran. Comparative investigations were carried out using various concentrations of DDMC and DNA in the introduction of DNA encoding luciferase (pGL3 control vector; Promega) into COS-7 cells derived from African green monkey kidney cells. The complex formation reaction is thought to be directly proportional to the transformation rate, but the complex formation reaction between DDMC and DNA is significantly influenced by hydrophobic bonding strength along with hydrogen bonding strength and Coulomb forces due to the hydrophobicity of the grafted MMA sections. It is thought that the reaction is a Michaelis-Menten type complex formation reaction described by the following equation: Complex amount = K1 (DNA concentration)(DDMC concentration). In support of this equation, it was confirmed that the amount of formed complex was proportional to the RLU value.

LC-MS/MS signal suppression effects in the analysis of pesticides in complex environmental matrices.

PubMed

Choi, B K; Hercules, D M; Gusev, A I

2001-02-01

The application of LC separation and mobile phase additives in addressing LC-MS/MS matrix signal suppression effects for the analysis of pesticides in a complex environmental matrix was investigated. It was shown that signal suppression is most significant for analytes eluting early in the LC-MS analysis. Introduction of different buffers (e.g. ammonium formate, ammonium hydroxide, formic acid) into the LC mobile phase was effective in improving signal correlation between the matrix and standard samples. The signal improvement is dependent on buffer concentration as well as LC separation of the matrix components. The application of LC separation alone was not effective in addressing suppression effects when characterizing complex matrix samples. Overloading of the LC column by matrix components was found to significantly contribute to analyte-matrix co-elution and suppression of signal. This signal suppression effect can be efficiently compensated by 2D LC (LC-LC) separation techniques. The effectiveness of buffers and LC separation in improving signal correlation between standard and matrix samples is discussed.

Halo-shaped Flowing Atmospheric Pressure Afterglow – a Heavenly New Design for Simplified Sample Introduction and Improved Ionization in Ambient Mass Spectrometry

PubMed Central

Pfeuffer, Kevin P.; Schaper, J. Niklas; Shelley, Jacob T.; Ray, Steven J.; Chan, George C.-Y.; Bings, Nicolas H.; Hieftje, Gary M.

2013-01-01

The flowing atmospheric pressure afterglow (FAPA) is a promising new source for atmospheric pressure, ambient desorption/ionization mass spectrometry. However, problems exist with reproducible sample introduction into the FAPA source. To overcome this limitation, a new FAPA geometry has been developed in which concentric tubular electrodes are utilized to form a halo-shaped discharge; this geometry has been termed the halo-FAPA or h-FAPA. With this new geometry, it is still possible to achieve direct desorption and ionization from a surface; however, sample introduction through the inner capillary is also possible and improves interaction between the sample material (solution, vapor, or aerosol) and the plasma to promote desorption and ionization. The h-FAPA operates with a helium gas flow of 0.60 L/min outer, 0.30 L/min inner, applied current of 30 mA at 200 V for 6 watts of power. In addition, separation of the discharge proper and sample material prevents perturbations to the plasma. Optical-emission characterization and gas rotational temperatures reveal that the temperature of the discharge is not significantly affected (< 3% change at 450K) by water vapor during solution-aerosol sample introduction. The primary mass-spectral background species are protonated water clusters, and the primary analyte ions are protonated molecular ions (M+H+). Flexibility of the new ambient sampling source is demonstrated by coupling it with a laser ablation unit, a concentric nebulizer and a droplet-on-demand system for sample introduction. A novel arrangement is also presented in which the central channel of the h-FAPA is used as the inlet to a mass spectrometer. PMID:23808829

Halo-shaped flowing atmospheric pressure afterglow: a heavenly design for simplified sample introduction and improved ionization in ambient mass spectrometry.

PubMed

Pfeuffer, Kevin P; Schaper, J Niklas; Shelley, Jacob T; Ray, Steven J; Chan, George C-Y; Bings, Nicolas H; Hieftje, Gary M

2013-08-06

The flowing atmospheric-pressure afterglow (FAPA) is a promising new source for atmospheric-pressure, ambient desorption/ionization mass spectrometry. However, problems exist with reproducible sample introduction into the FAPA source. To overcome this limitation, a new FAPA geometry has been developed in which concentric tubular electrodes are utilized to form a halo-shaped discharge; this geometry has been termed the halo-FAPA or h-FAPA. With this new geometry, it is still possible to achieve direct desorption and ionization from a surface; however, sample introduction through the inner capillary is also possible and improves interaction between the sample material (solution, vapor, or aerosol) and the plasma to promote desorption and ionization. The h-FAPA operates with a helium gas flow of 0.60 L/min outer, 0.30 L/min inner, and applied current of 30 mA at 200 V for 6 W of power. In addition, separation of the discharge proper and sample material prevents perturbations to the plasma. Optical-emission characterization and gas rotational temperatures reveal that the temperature of the discharge is not significantly affected (<3% change at 450 K) by water vapor during solution-aerosol sample introduction. The primary mass-spectral background species are protonated water clusters, and the primary analyte ions are protonated molecular ions (M + H(+)). Flexibility of the new ambient sampling source is demonstrated by coupling it with a laser ablation unit, a concentric nebulizer, and a droplet-on-demand system for sample introduction. A novel arrangement is also presented in which the central channel of the h-FAPA is used as the inlet to a mass spectrometer.

Monochromatic-beam-based dynamic X-ray microtomography based on OSEM-TV algorithm.

PubMed

Xu, Liang; Chen, Rongchang; Yang, Yiming; Deng, Biao; Du, Guohao; Xie, Honglan; Xiao, Tiqiao

2017-01-01

Monochromatic-beam-based dynamic X-ray computed microtomography (CT) was developed to observe evolution of microstructure inside samples. However, the low flux density results in low efficiency in data collection. To increase efficiency, reducing the number of projections should be a practical solution. However, it has disadvantages of low image reconstruction quality using the traditional filtered back projection (FBP) algorithm. In this study, an iterative reconstruction method using an ordered subset expectation maximization-total variation (OSEM-TV) algorithm was employed to address and solve this problem. The simulated results demonstrated that normalized mean square error of the image slices reconstructed by the OSEM-TV algorithm was about 1/4 of that by FBP. Experimental results also demonstrated that the density resolution of OSEM-TV was high enough to resolve different materials with the number of projections less than 100. As a result, with the introduction of OSEM-TV, the monochromatic-beam-based dynamic X-ray microtomography is potentially practicable for the quantitative and non-destructive analysis to the evolution of microstructure with acceptable efficiency in data collection and reconstructed image quality.

Efficient introduction of specific homozygous and heterozygous mutations using CRISPR/Cas9.

PubMed

Paquet, Dominik; Kwart, Dylan; Chen, Antonia; Sproul, Andrew; Jacob, Samson; Teo, Shaun; Olsen, Kimberly Moore; Gregg, Andrew; Noggle, Scott; Tessier-Lavigne, Marc

2016-05-05

The bacterial CRISPR/Cas9 system allows sequence-specific gene editing in many organisms and holds promise as a tool to generate models of human diseases, for example, in human pluripotent stem cells. CRISPR/Cas9 introduces targeted double-stranded breaks (DSBs) with high efficiency, which are typically repaired by non-homologous end-joining (NHEJ) resulting in nonspecific insertions, deletions or other mutations (indels). DSBs may also be repaired by homology-directed repair (HDR) using a DNA repair template, such as an introduced single-stranded oligo DNA nucleotide (ssODN), allowing knock-in of specific mutations. Although CRISPR/Cas9 is used extensively to engineer gene knockouts through NHEJ, editing by HDR remains inefficient and can be corrupted by additional indels, preventing its widespread use for modelling genetic disorders through introducing disease-associated mutations. Furthermore, targeted mutational knock-in at single alleles to model diseases caused by heterozygous mutations has not been reported. Here we describe a CRISPR/Cas9-based genome-editing framework that allows selective introduction of mono- and bi-allelic sequence changes with high efficiency and accuracy. We show that HDR accuracy is increased dramatically by incorporating silent CRISPR/Cas-blocking mutations along with pathogenic mutations, and establish a method termed 'CORRECT' for scarless genome editing. By characterizing and exploiting a stereotyped inverse relationship between a mutation's incorporation rate and its distance to the DSB, we achieve predictable control of zygosity. Homozygous introduction requires a guide RNA targeting close to the intended mutation, whereas heterozygous introduction can be accomplished by distance-dependent suboptimal mutation incorporation or by use of mixed repair templates. Using this approach, we generated human induced pluripotent stem cells with heterozygous and homozygous dominant early onset Alzheimer's disease-causing mutations in amyloid precursor protein (APP(Swe)) and presenilin 1 (PSEN1(M146V)) and derived cortical neurons, which displayed genotype-dependent disease-associated phenotypes. Our findings enable efficient introduction of specific sequence changes with CRISPR/Cas9, facilitating study of human disease.

Molecular modification of coumarin dyes for more efficient dye sensitized solar cells

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

Sanchez-de-Armas, Rocio; San-Miguel, Miguel A.; Oviedo, Jaime

2012-05-21

In this work, new coumarin based dyes for dye sensitized solar cells (DSSC) have been designed by introducing several substituent groups in different positions of the NKX-2311 structure. Two types of substitutions have been considered: the introduction of three electron-donating groups (-OH, -NH{sub 2}, and -OCH{sub 3}) and two different substituents with steric effect: -CH{sub 2}-CH{sub 2}-CH{sub 2}- and -CH{sub 2}-HC=CH-. The electronic absorption spectra (position and width of the first band and absorption threshold) and the position of the LUMO level related to the conduction band have been used as theoretical criteria to evaluate the efficiency of the newmore » dyes. The introduction of a -NH{sub 2} group produces a redshift of the absorption maximum position and the absorption threshold, which could improve the cell efficiency. In contrast, the introduction of -CH{sub 2}-CH{sub 2}-CH{sub 2}- does not modify significantly the electronic structure of NKX-2311, but it might prevent aggregation. Finally, -CH{sub 2}-HC=CH- produces important changes both in the electronic spectrum and in the electronic structure of the dye, and it would be expected as an improvement of cell efficiency for these dyes.« less

An Open Port Sampling Interface for Liquid Introduction Atmospheric Pressure Ionization Mass Spectrometry

DOE PAGES

Van Berkel, Gary J.; Kertesz, Vilmos

2015-08-25

RATIONALE: A simple method to introduce unprocessed samples into a solvent for rapid characterization by liquid introduction atmospheric pressure ionization mass spectrometry has been lacking. The continuous flow, self-cleaning open port sampling interface introduced here fills this void. METHODS: The open port sampling interface used a vertically aligned, co-axial tube arrangement enabling solvent delivery to the sampling end of the device through the tubing annulus and solvent aspiration down the center tube and into the mass spectrometer ionization source via the commercial APCI emitter probe. The solvent delivery rate to the interface was set to exceed the aspiration rate creatingmore » a continuous sampling interface along with a constant, self-cleaning spillover of solvent from the top of the probe. RESULTS: Using the open port sampling interface with positive ion mode APCI and a hybrid quadrupole time of flight mass spectrometer, rapid, direct sampling and analysis possibilities are exemplified with plastics, ballpoint and felt tip ink pens, skin, and vegetable oils. These results demonstrated that the open port sampling interface could be used as a simple, versatile and self-cleaning system to rapidly introduce multiple types of unprocessed, sometimes highly concentrated and complex, samples into a solvent flow stream for subsequent ionization and analysis by mass spectrometry. The basic setup presented here could be incorporated with any self-aspirating liquid introduction ionization source (e.g., ESI, APCI, APPI, ICP, etc.) or any type of atmospheric pressure sampling ready mass spectrometer system. CONCLUSIONS: The open port sampling interface provides a means to introduce and quickly analyze unprocessed solid or liquid samples with liquid introduction atmospheric pressure ionization source without fear of sampling interface or ionization source contamination.« less

Laser ablation inductively coupled plasma mass spectrometry measurement of isotope ratios in depleted uranium contaminated soils.

PubMed

Seltzer, Michael D

2003-09-01

Laser ablation of pressed soil pellets was examined as a means of direct sample introduction to enable inductively coupled plasma mass spectrometry (ICP-MS) screening of soils for residual depleted uranium (DU) contamination. Differentiation between depleted uranium, an anthropogenic contaminant, and naturally occurring uranium was accomplished on the basis of measured 235U/238U isotope ratios. The amount of sample preparation required for laser ablation is considerably less than that typically required for aqueous sample introduction. The amount of hazardous laboratory waste generated is diminished accordingly. During the present investigation, 235U/238U isotope ratios measured for field samples were in good agreement with those derived from gamma spectrometry measurements. However, substantial compensation was required to mitigate the effects of impaired pulse counting attributed to sample inhomogeneity and sporadic introduction of uranium analyte into the plasma.

Highly reproducible alkali metal doping system for organic crystals through enhanced diffusion of alkali metal by secondary thermal activation.

PubMed

Lee, Jinho; Park, Chibeom; Song, Intek; Koo, Jin Young; Yoon, Taekyung; Kim, Jun Sung; Choi, Hee Cheul

2018-05-16

In this paper, we report an efficient alkali metal doping system for organic single crystals. Our system employs an enhanced diffusion method for the introduction of alkali metal into organic single crystals by controlling the sample temperature to induce secondary thermal activation. Using this system, we achieved intercalation of potassium into picene single crystals with closed packed crystal structures. Using optical microscopy and Raman spectroscopy, we confirmed that the resulting samples were uniformly doped and became K 2 picene single crystal, while only parts of the crystal are doped and transformed into K 2 picene without secondary thermal activation. Moreover, using a customized electrical measurement system, the insulator-to-semiconductor transition of picene single crystals upon doping was confirmed by in situ electrical conductivity and ex situ temperature-dependent resistivity measurements. X-ray diffraction studies showed that potassium atoms were intercalated between molecular layers of picene, and doped samples did not show any KH- nor KOH-related peaks, indicating that picene molecules are retained without structural decomposition. During recent decades, tremendous efforts have been exerted to develop high-performance organic semiconductors and superconductors, whereas as little attention has been devoted to doped organic crystals. Our method will enable efficient alkali metal doping of organic crystals and will be a resource for future systematic studies on the electrical property changes of these organic crystals upon doping.

Remediation of phenanthrene from contaminated kaolinite by electroremediation-Fenton technology.

PubMed

Alcantara, T; Pazos, M; Gouveia, S; Cameselle, C; Sanroman, M A

2008-07-01

Polycyclic aromatic hydrocarbons (PAHs) cause a high environmental impact when released into the environment. The objective of this study was to evaluate the capacity to decontaminate polluted soils with phenanthrene as a model PAH using a combination of two technologies: electrokinetic remediation and Fenton process. Kaolinite was used as a model sample that was artificially polluted at the laboratory at an initial concentration of phenanthrene of 500 mg kg(-1) of dried kaolinite. The standard electrokinetic process resulted in negligible removal of phenanthrene from the kaolinite sample. Faster and more efficient degradation of this compound can be promoted by introduction of a strong oxidant into the soil such as hydroxyl radicals. For this reason, the Fenton reactions have been induced in several experiments in which H(2)O(2) (10%) was used as flushing solution, and kaolinite polluted with iron was used. When anode and cathode chambers were filled with H(2)O(2) (10%), the kaolinite pH is maintained at an acid value around 3.5 without pH control and an overall removal and destruction efficiency of phenanthrene of 99% was obtained in 14 days by applying a voltage gradient of 3 V cm(-1). Therefore, it is evident that a combined technology of electrokinetic remediation and Fenton reaction is capable of simultaneously removing and degrading of PAHs in polluted model samples with kaolinite.

Quality control for quantitative PCR based on amplification compatibility test.

PubMed

Tichopad, Ales; Bar, Tzachi; Pecen, Ladislav; Kitchen, Robert R; Kubista, Mikael; Pfaffl, Michael W

2010-04-01

Quantitative qPCR is a routinely used method for the accurate quantification of nucleic acids. Yet it may generate erroneous results if the amplification process is obscured by inhibition or generation of aberrant side-products such as primer dimers. Several methods have been established to control for pre-processing performance that rely on the introduction of a co-amplified reference sequence, however there is currently no method to allow for reliable control of the amplification process without directly modifying the sample mix. Herein we present a statistical approach based on multivariate analysis of the amplification response data generated in real-time. The amplification trajectory in its most resolved and dynamic phase is fitted with a suitable model. Two parameters of this model, related to amplification efficiency, are then used for calculation of the Z-score statistics. Each studied sample is compared to a predefined reference set of reactions, typically calibration reactions. A probabilistic decision for each individual Z-score is then used to identify the majority of inhibited reactions in our experiments. We compare this approach to univariate methods using only the sample specific amplification efficiency as reporter of the compatibility. We demonstrate improved identification performance using the multivariate approach compared to the univariate approach. Finally we stress that the performance of the amplification compatibility test as a quality control procedure depends on the quality of the reference set. Copyright 2010 Elsevier Inc. All rights reserved.

Synthesis of 8-Aryl-O-methylcyanidins and Their Usage for Dye-Sensitized Solar Cell Devices.

PubMed

Kimura, Yuki; Oyama, Kin-Ichi; Murata, Yasujiro; Wakamiya, Atsushi; Yoshida, Kumi

2017-02-16

Anthocyanins as natural pigments are colorful and environmentally compatible dyes for dye-sensitized solar cells (DSSCs). To increase the efficiency, we designed and synthesized unnatural O -methylflavonols and O -methylcyanidins that possess an aryl group at the 8-position. We synthesized per - O -methylquercetin from quercetin, then using selective demethylation prepared various O -methylquercetins. Using the Suzuki-Miyaura coupling reaction, 8-arylation of per - O -methylquercetin was achieved. Using a LiAlH₄ reduction or Clemmensen reduction, these flavonols were transformed to the corresponding cyanidin derivatives in satisfactory yields. Using these dyes, we fabricated DSSCs, and their efficiency was investigated. The efficiency of tetra - O -methylflavonol was 0.31%. However, the introduction of the 8-aryl residue increased the efficiency to 1.04%. In comparison to these flavonols, O -methylcyanidins exhibited a lower efficiency of 0.05% to 0.52%. The introduction of the 8-aryl group into the cyanidin derivatives did not result in a remarkable increase in the efficiency. These phenomena may be due to the poor fit of the HOMO-LUMO level of the dyes to the TiO₂ conduction band.

Drop-on-demand sample introduction system coupled with the flowing atmospheric-pressure afterglow for direct molecular analysis of complex liquid micro-volume samples

PubMed Central

Schaper, J. Niklas; Pfeuffer, Kevin P.; Shelley, Jacob T.; Bings, Nicolas H.

2012-01-01

One of the fastest developing fields in analytical spectrochemistry in recent years is ambient desorption/ionization mass spectrometry (ADI-MS). This burgeoning interest has been due to the demonstrated advantages of the method: simple mass spectra, little or no sample preparation, and applicability to samples in the solid, liquid, or gaseous state. One such ADI-MS source, the flowing atmospheric-pressure afterglow (FAPA), is capable of direct analysis of solids just by aiming the source at the solid surface and sampling the produced ions into a mass spectrometer. However, direct introduction of significant volumes of liquid samples into this source has not been possible, as solvent loads can quench the afterglow and, thus, the formation of reagent ions. As a result, the analysis of liquid samples is preferably carried out by analyzing dried residues or by desorbing small amounts of liquid samples directly from the liquid surface. In the former case, reproducibility of sample introduction is crucial if quantitative results are desired. In the present study, introduction of liquid samples as very small droplets helps overcome the issues of sample positioning and reduced levels of solvent intake. A recently developed “drop-on-demand” (DOD) aerosol generator is capable of reproducibly producing very small volumes of liquid (~17 pL). In this paper, the coupling of FAPA-MS and DOD is reported and applications are suggested. Analytes representing different classes of substances were tested and limits of detections were determined. Matrix tolerance was investigated for drugs of abuse and their metabolites by analyzing raw urine samples and quantification without the use of internal standards. Limits of detection below 2 µg/mL, without sample pretreatment, were obtained. PMID:23025277

Drop-on-demand sample introduction system coupled with the flowing atmospheric-pressure afterglow for direct molecular analysis of complex liquid microvolume samples.

PubMed

Schaper, J Niklas; Pfeuffer, Kevin P; Shelley, Jacob T; Bings, Nicolas H; Hieftje, Gary M

2012-11-06

One of the fastest developing fields in analytical spectrochemistry in recent years is ambient desorption/ionization mass spectrometry (ADI-MS). This burgeoning interest has been due to the demonstrated advantages of the method: simple mass spectra, little or no sample preparation, and applicability to samples in the solid, liquid, or gaseous state. One such ADI-MS source, the flowing atmospheric-pressure afterglow (FAPA), is capable of direct analysis of solids just by aiming the source at the solid surface and sampling the produced ions into a mass spectrometer. However, direct introduction of significant volumes of liquid samples into this source has not been possible, as solvent loads can quench the afterglow and, thus, the formation of reagent ions. As a result, the analysis of liquid samples is preferably carried out by analyzing dried residues or by desorbing small amounts of liquid samples directly from the liquid surface. In the former case, reproducibility of sample introduction is crucial if quantitative results are desired. In the present study, introduction of liquid samples as very small droplets helps overcome the issues of sample positioning and reduced levels of solvent intake. A recently developed "drop-on-demand" (DOD) aerosol generator is capable of reproducibly producing very small volumes of liquid (∼17 pL). In this paper, the coupling of FAPA-MS and DOD is reported and applications are suggested. Analytes representing different classes of substances were tested and limits of detections were determined. Matrix tolerance was investigated for drugs of abuse and their metabolites by analyzing raw urine samples and quantification without the use of internal standards. Limits of detection below 2 μg/mL, without sample pretreatment, were obtained.

Getting Started in Classroom Computing.

ERIC Educational Resources Information Center

Ahl, David H.

Written for secondary students, this booklet provides an introduction to several computer-related concepts through a set of six classroom games, most of which can be played with little more than a sheet of paper and a pencil. The games are: 1) SECRET CODES--introduction to binary coding, punched cards, and paper tape; 2) GUESS--efficient methods…

Spatial and Temporal Analysis of Populations of the Sudden Oak Death Pathogen in Oregon Forests.

PubMed

Kamvar, Z N; Larsen, M M; Kanaskie, A M; Hansen, E M; Grünwald, N J

2015-07-01

Sudden oak death caused by the oomycete Phytophthora ramorum was first discovered in California toward the end of the 20th century and subsequently emerged on tanoak forests in Oregon before its first detection in 2001 by aerial surveys. The Oregon Department of Forestry has since monitored the epidemic and sampled symptomatic tanoak trees from 2001 to the present. Populations sampled over this period were genotyped using microsatellites and studied to infer the population genetic history. To date, only the NA1 clonal lineage is established in this region, although three lineages exist on the North American west coast. The original introduction into the Joe Hall area eventually spread to several regions: mostly north but also east and southwest. A new introduction into Hunter Creek appears to correspond to a second introduction not clustering with the early introduction. Our data are best explained by both introductions originating from nursery populations in California or Oregon and resulting from two distinct introduction events. Continued vigilance and eradication of nursery populations of P. ramorum are important to avoid further emergence and potential introduction of other clonal lineages.

The challenge of corporatisation: the experience of Portuguese public hospitals.

PubMed

Rego, Guilhermina; Nunes, Rui; Costa, José

2010-08-01

The inability of traditional state organisations to respond to new economic, technological and social challenges and the associated emerging problems has made it necessary to adopt new methods of health management. As a result, new directions have emerged in the reform of Public Administration together with the introduction of innovative models. The aim is to achieve a type of management that focuses on results as well as on effort and efficiency. We intend to analyse to what extent the adoption of business management models by hospital healthcare units can improve their performance, mainly in terms of standards of efficiency. Data envelopment analysis (DEA) was used to investigate the efficiency of a set of public Portuguese hospitals. The aim was to evaluate the impact of business management in Portuguese public hospitals with regards to efficiency, specifically taking into account the fact that lack of resources and increased health care needs are a present and future reality. From a total of 83 public hospitals, a sample of 59 hospitals was chosen, of which 21 are state-owned hospital enterprises (SA) and 38 are traditional public administration sector hospitals (SPA). This study evaluates hospital performance by calculating two efficiency measures associated with two categories of inputs. The first efficiency measures the costs associated with hospital production lines and the number of beds (representing fixed capacity) as inputs. The annual costs generated by the hospitals in the consumption of capital and work (direct and indirect costs) are used. A second measure of efficiency is calculated separately. This measure includes in the inputs the number of beds as well as the human resources available (number of doctors, number of nurses and other personnel) in each hospital. With regard to output, the variables that best reflect the hospital services rendered were considered: number of inpatient days, patients discharged, outpatient visits, emergencies services, sessions in hospital day care services and the number of surgeries. The results seem to suggest that the introduction of market processes and changes in organisational structure--such as managerial autonomy and corporatisation of public hospitals--have had a positive impact on Portuguese public hospitals. This positive evolution was particularly evident in SA hospitals, but further studies are needed to confirm these preliminary results.

Railway Transportation Engineering (CEE 408) Course updates and online conversion.

DOT National Transportation Integrated Search

2017-01-20

The new order of lectures provides students with a sound introduction to the main concepts behind efficiency and economic railway operations. This naturally follows into the design of railcars for safe, efficient and economical operations. With railc...

Rapid assessment of non-indigenous species in the era of the eDNA barcoding: A Mediterranean case study

NASA Astrophysics Data System (ADS)

Ardura, Alba; Planes, Serge

2017-03-01

With only a narrow opening through the Gibraltar and Suez Canals, the Mediterranean Sea is one of the largest semi-enclosed seas. The marine flora and fauna are some of the richest in the world, relative to its size, particularly in the coastal habitats, which are also characterized by numerous endemic species although the introduction of non-indigenous species threatens its rich and unique biodiversity. Following the opening of the Suez Canal, and in combination with shipping and aquaculture activities, non-indigenous species (NIS) introduction has had measurable impacts on the Mediterranean. Lagoon ecosystems along the French coastline, with approx. 100 NIS identified, are considered hot-spot areas for these species. Rapid assessment sampling for sessile benthic species together with DNA barcoding is a rapid, easy and cheap method to detect non-indigenous species. Two nearby and different ecosystems were sampled for invertebrate species: Saint-Nazaire lagoon, a Special Protection Area within the Natura 2000 Network and Canet port, a marina in a small village. The DNA barcoding tool for species identification was used for confirming the taxonomy. This showed that, despite the Saint-Nazaire Lagoon classification within the Natura 2000 network, it is already contaminated with a single NIS that was found in high densities and is clearly beginning to dominate the system. It is proposed that a rapid assessment of the sampled environment and the DNA barcode approach are efficient and can provide sufficient information on the new target species to be used in conservation planning and ongoing management efforts.

High-throughput DNA extraction of forensic adhesive tapes.

PubMed

Forsberg, Christina; Jansson, Linda; Ansell, Ricky; Hedman, Johannes

2016-09-01

Tape-lifting has since its introduction in the early 2000's become a well-established sampling method in forensic DNA analysis. Sampling is quick and straightforward while the following DNA extraction is more challenging due to the "stickiness", rigidity and size of the tape. We have developed, validated and implemented a simple and efficient direct lysis DNA extraction protocol for adhesive tapes that requires limited manual labour. The method uses Chelex beads and is applied with SceneSafe FAST tape. This direct lysis protocol provided higher mean DNA yields than PrepFiler Express BTA on Automate Express, although the differences were not significant when using clothes worn in a controlled fashion as reference material (p=0.13 and p=0.34 for T-shirts and button-down shirts, respectively). Through in-house validation we show that the method is fit-for-purpose for application in casework, as it provides high DNA yields and amplifiability, as well as good reproducibility and DNA extract stability. After implementation in casework, the proportion of extracts with DNA concentrations above 0.01ng/μL increased from 71% to 76%. Apart from providing higher DNA yields compared with the previous method, the introduction of the developed direct lysis protocol also reduced the amount of manual labour by half and doubled the potential throughput for tapes at the laboratory. Generally, simplified manual protocols can serve as a cost-effective alternative to sophisticated automation solutions when the aim is to enable high-throughput DNA extraction of complex crime scene samples. Copyright © 2016 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

Differing courses of genetic evolution of Bradyrhizobium inoculants as revealed by long-term molecular tracing in Acacia mangium plantations.

PubMed

Perrineau, M M; Le Roux, C; Galiana, A; Faye, A; Duponnois, R; Goh, D; Prin, Y; Béna, G

2014-09-01

Introducing nitrogen-fixing bacteria as an inoculum in association with legume crops is a common practice in agriculture. However, the question of the evolution of these introduced microorganisms remains crucial, both in terms of microbial ecology and agronomy. We explored this question by analyzing the genetic and symbiotic evolution of two Bradyrhizobium strains inoculated on Acacia mangium in Malaysia and Senegal 15 and 5 years, respectively, after their introduction. Based on typing of several loci, we showed that these two strains, although closely related and originally sampled in Australia, evolved differently. One strain was recovered in soil with the same five loci as the original isolate, whereas the symbiotic cluster of the other strain was detected with no trace of the three housekeeping genes of the original inoculum. Moreover, the nitrogen fixation efficiency was variable among these isolates (either recombinant or not), with significantly high, low, or similar efficiencies compared to the two original strains and no significant difference between recombinant and nonrecombinant isolates. These data suggested that 15 years after their introduction, nitrogen-fixing bacteria remain in the soil but that closely related inoculant strains may not evolve in the same way, either genetically or symbiotically. In a context of increasing agronomical use of microbial inoculants (for biological control, nitrogen fixation, or plant growth promotion), this result feeds the debate on the consequences associated with such practices. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

Differing Courses of Genetic Evolution of Bradyrhizobium Inoculants as Revealed by Long-Term Molecular Tracing in Acacia mangium Plantations

PubMed Central

Perrineau, M. M.; Le Roux, C.; Galiana, A.; Faye, A.; Duponnois, R.; Goh, D.; Prin, Y.

2014-01-01

Introducing nitrogen-fixing bacteria as an inoculum in association with legume crops is a common practice in agriculture. However, the question of the evolution of these introduced microorganisms remains crucial, both in terms of microbial ecology and agronomy. We explored this question by analyzing the genetic and symbiotic evolution of two Bradyrhizobium strains inoculated on Acacia mangium in Malaysia and Senegal 15 and 5 years, respectively, after their introduction. Based on typing of several loci, we showed that these two strains, although closely related and originally sampled in Australia, evolved differently. One strain was recovered in soil with the same five loci as the original isolate, whereas the symbiotic cluster of the other strain was detected with no trace of the three housekeeping genes of the original inoculum. Moreover, the nitrogen fixation efficiency was variable among these isolates (either recombinant or not), with significantly high, low, or similar efficiencies compared to the two original strains and no significant difference between recombinant and nonrecombinant isolates. These data suggested that 15 years after their introduction, nitrogen-fixing bacteria remain in the soil but that closely related inoculant strains may not evolve in the same way, either genetically or symbiotically. In a context of increasing agronomical use of microbial inoculants (for biological control, nitrogen fixation, or plant growth promotion), this result feeds the debate on the consequences associated with such practices. PMID:25002434

Optimizing information technology to improve sexual health-care delivery: public and patient preferences.

PubMed

Ross, J D C; Copas, A; Stephenson, J; Fellows, L; Gilleran, G

2007-07-01

Information and communication technology (ICT) has the potential to improve the quality of care and efficiency in sexual health clinics, but its introduction requires input not only from health-care professionals and ICT specialists but also from service users and potential future users. In this study, views on ICT in relation to the delivery of sexual health services were assessed using a structured interview in two groups - a community sample of young people and a clinic sample of existing patients. In all, 542 community interviewees and 202 clinic patients participated. About 75% of respondents had access to the Internet and overall 60% reported that the self-collection of a sexual history on an electronic form was acceptable. Black Caribbean individuals had significantly less access to the Internet and a lower acceptance of electronic data collection. For booking an appointment, the majority of patients reported the telephone (community sample 93%, clinic sample 96%) or attending in person (community sample 77%, clinic sample 54%) to be acceptable, with a smaller proportion choosing email (community sample 10%, clinic sample 27%) or the Internet (community sample 7%, clinic sample 11%). Electronic booking was significantly less acceptable to Black Caribbean respondents. Although new technologies offer the opportunity to improve the quality of sexual health services, patient preferences and differences between groups in access to technology also need to be considered when services are reconfigured.

Synthesis of modified proanthocyanidins: easy and general introduction of a hydroxy group at C-6 of catechin; efficient synthesis of elephantorrhizol.

PubMed

Boyer, François-Didier; Es-Safi, Nour-Eddine; Beauhaire, Josiane; Guernevé, Christine Le; Ducrot, Paul-Henri

2005-02-01

A general procedure for the oxidation of catechin derivatives is described, leading to the introduction of a new hydroxy group at C-6. This procedure has been applied for the synthesis of elephantorrhizol, a natural flavan-3-ol exhibiting a fully substituted cycle A.

Rotavirus vaccine effectiveness in preventing hospitalizations due to gastroenteritis: a descriptive epidemiological study from Germany.

PubMed

Pietsch, C; Liebert, U G

2018-04-10

Rotavirus infections are common causes of infant hospitalization. The present study examined the effectiveness of anti-rotavirus vaccination in preventing rotavirus-related hospitalizations in Germany, following its state and nationwide introductions in 2008 and 2013, respectively. During 15 consecutive seasons 9557 stool samples of hospitalized children of 5 years and younger with acute gastroenteritis were screened for rotavirus A. Rotavirus G and P genotypes were assessed after vaccine introduction. Vaccine effectiveness was determined by comparison of rotavirus incidence in pre-vaccine and post-vaccine cohorts. The herd effect was calculated as the difference between the observed reduction of rotavirus-related hospitalizations and the expected direct vaccine effect. The number of rotavirus-related hospitalizations declined after vaccine introduction. Approximately 26% (503/1955) of prevented cases could be attributed to the herd effect. Human rotaviruses of genotypes G3P[8], G1P[8], G9P[8], G4P[8], G2P[4] and G12P[8] were most frequent. Uncommon genotypes remained rare. The direct, indirect, total and overall vaccine effectiveness was 86% (95% confidence interval (CI) 83.2-89.1%), 48% (95% CI 42.8-52.6%), 93% (95% CI 91.3-94.3%) and 69% (95% CI 66.5-72.0%), respectively. There was no significant difference in vaccine-type or in genotype-specific vaccine effectiveness. Anti-rotavirus vaccination efficiently reduced rotavirus-related hospitalizations in Germany in the past decade. The vaccines analysed in this article provide a broadly heterologous and long-lasting protection. The herd effect substantially contributed to the observed drop in the number of incidences of severe rotavirus infections. Presumably, constant high vaccine coverage will lead to a continued upward trend in the overall vaccine efficiency. Copyright © 2018 European Society of Clinical Microbiology and Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

NEOCHIM: An electrochemical method for environmental application

USGS Publications Warehouse

Leinz, R.W.; Hoover, D.B.; Meier, A.L.

1999-01-01

Ion migration and electroosmosis are the principal processes underlying electrokinetic remediation of hazardous wastes from soils. These processes are a response of charged species to an applied electrical current and they are accompanied by electrolysis of water at the electrodes through which the current is applied. Electrolysis results in the formation of OH- at the cathode and H+ at the anode. The current drives the OH- and H+ thus formed from the electrodes, through the soil and to the electrode of opposite charge. Introduction of OH- and H+ into the soil being treated modifies soil chemistry and can interfere with either the collection or immobilization of hazardous waste ions. The introduction of either OH- or H+ to the soil can be problematic to electrokinetic remediation but the problem caused by OH- has been the focus of most researchers. The problem has been addressed by flushing the OH- from the soil near the cathode or treating the soil with buffers. These treatments would apply as well to soils affected by H+. With the NEOCHIM technology, developed by the U.S. Geological Survey (USGS) for use as a sampling technique in exploration for buried ore deposits, OH- and H+ are retained in the inner compartment of two-compartment electrodes and are thus prevented from reaching the soil. This enables the extraction of cations and anions, including anionic forms of toxic metals such as HAsO42-. One of the principal attributes of NEOCHIM is the large volume of soil from which ions can be extracted. It is mathematically demonstrable that NEOCHIM extraction volumes can be orders of magnitude greater than volumes typically sampled in more conventional geochemical exploration methods or for environmental sampling. The technology may also be used to introduce selected ions into the soil that affect the solubility of ceratin ions present in the soil. Although field tests for mineral exploration have shown NEOCHIM extraction efficiencies of about 25-35%, laboratory experiments suggest that significantly higher efficiencies are possible. The attributes of NEOCHIM combined with relatively low cost of electrical power, indicate that the technology may be useful for remediation and monitoring of hazardous waste sites. Of particular importance is that NEOCHIM extractions affect only dissolved and electrically charged species, hence those prone to move in groundwater.The U.S. Geological Survey (USGS) has developed a technology called NEOCHIM for use as a sampling technique in exploration for buried deposits. With this technology, OH- and H+ are retained in the inner compartment of two-compartment electrodes and are thus prevented from reaching the soil. This enables the extraction of cations and anions. Laboratory experiments suggest extraction efficiencies higher than 25-35%.

Evaluation of DNA extraction methods for PCR-based detection of Listeria monocytogenes from vegetables.

PubMed

Vojkovska, H; Kubikova, I; Kralik, P

2015-03-01

Epidemiological data indicate that raw vegetables are associated with outbreaks of Listeria monocytogenes. Therefore, there is a demand for the availability of rapid and sensitive methods, such as PCR assays, for the detection and accurate discrimination of L. monocytogenes. However, the efficiency of PCR methods can be negatively affected by inhibitory compounds commonly found in vegetable matrices that may cause false-negative results. Therefore, the sample processing and DNA isolation steps must be carefully evaluated prior to the introduction of such methods into routine practice. In this study, we compared the ability of three column-based and four magnetic bead-based commercial DNA isolation kits to extract DNA of the model micro-organism L. monocytogenes from raw vegetables. The DNA isolation efficiency of all isolation kits was determined using a triplex real-time qPCR assay designed to specifically detect L. monocytogenes. The kit with best performance, the PowerSoil(™) Microbial DNA Isolation Kit, is suitable for the extraction of amplifiable DNA from L. monocytogenes cells in vegetable with efficiencies ranging between 29.6 and 70.3%. Coupled with the triplex real-time qPCR assay, this DNA isolation kit is applicable to the samples with bacterial loads of 10(3) bacterial cells per gram of L. monocytogenes. Several recent outbreaks of Listeria monocytogenes have been associated with the consumption of fruits and vegetables. Real-time PCR assays allow fast detection and accurate quantification of microbes. However, the success of real-time PCR is dependent on the success with which template DNA can be extracted. The results of this study suggest that the PowerSoil(™) Microbial DNA Isolation Kit can be used for the extraction of amplifiable DNA from L. monocytogenes cells in vegetable with efficiencies ranging between 29.6 and 70.3%. This method is applicable to samples with bacterial loads of 10(3) bacterial cells per gram of L. monocytogenes. © 2014 The Society for Applied Microbiology.

48 CFR 23.202 - Policy.

Code of Federal Regulations, 2013 CFR

2013-10-01

... ENVIRONMENT, ENERGY AND WATER EFFICIENCY, RENEWABLE ENERGY TECHNOLOGIES, OCCUPATIONAL SAFETY, AND DRUG-FREE WORKPLACE Energy and Water Efficiency and Renewable Energy 23.202 Policy. (a) Introduction. The Government's policy is to acquire supplies and services that promote a clean energy economy that increases our Nation...

48 CFR 23.202 - Policy.

Code of Federal Regulations, 2014 CFR

2014-10-01

... ENVIRONMENT, ENERGY AND WATER EFFICIENCY, RENEWABLE ENERGY TECHNOLOGIES, OCCUPATIONAL SAFETY, AND DRUG-FREE WORKPLACE Energy and Water Efficiency and Renewable Energy 23.202 Policy. (a) Introduction. The Government's policy is to acquire supplies and services that promote a clean energy economy that increases our Nation...

48 CFR 23.202 - Policy.

Code of Federal Regulations, 2011 CFR

2011-10-01

... ENVIRONMENT, ENERGY AND WATER EFFICIENCY, RENEWABLE ENERGY TECHNOLOGIES, OCCUPATIONAL SAFETY, AND DRUG-FREE WORKPLACE Energy and Water Efficiency and Renewable Energy 23.202 Policy. (a) Introduction. The Government's policy is to acquire supplies and services that promote a clean energy economy that increases our Nation...

48 CFR 23.202 - Policy.

Code of Federal Regulations, 2012 CFR

2012-10-01

... ENVIRONMENT, ENERGY AND WATER EFFICIENCY, RENEWABLE ENERGY TECHNOLOGIES, OCCUPATIONAL SAFETY, AND DRUG-FREE WORKPLACE Energy and Water Efficiency and Renewable Energy 23.202 Policy. (a) Introduction. The Government's policy is to acquire supplies and services that promote a clean energy economy that increases our Nation...

Simulation of a Novel Single-column Cryogenic Air Separation Process Using LNG Cold Energy

NASA Astrophysics Data System (ADS)

Jieyu, Zheng; Yanzhong, Li; Guangpeng, Li; Biao, Si

In this paper, a novel single-column air separation process is proposed with the implementation of heat pump technique and introduction of LNG coldenergy. The proposed process is verifiedand optimized through simulation on the Aspen Hysys® platform. Simulation results reveal that thepower consumption per unit mass of liquid productis around 0.218 kWh/kg, and the total exergy efficiency of the systemis 0.575. According to the latest literatures, an energy saving of 39.1% is achieved compared with those using conventional double-column air separation units.The introduction of LNG cold energy is an effective way to increase the system efficiency.

Evaluation of electricity generation from ultrasonic and heat/alkaline pretreatment of different sludge types using microbial fuel cells.

PubMed

Oh, Sang-Eun; Yoon, Joung Yee; Gurung, Anup; Kim, Dong-Jin

2014-08-01

This study investigated the effects of different sludge pretreatment methods (ultrasonic vs. combined heat/alkali) with varied sources of municipal sewage sludge (primary sludge (PS), secondary excess sludge (ES), anaerobic digestion sludge (ADS)) on electricity generation in microbial fuel cells (MFCs). Introduction of ultrasonically pretreated sludge (PS, ES, ADS) to MFCs generated maximum power densities of 13.59, 9.78 and 12.67mW/m(2) and soluble COD (SCOD) removal efficiencies of 87%, 90% and 57%, respectively. The sludge pretreated by combined heat/alkali (0.04N NaOH at 120°C for 1h) produced maximum power densities of 10.03, 5.21 and 12.53mW/m(2) and SCOD removal efficiencies of 83%, 75% and 74% with PS, ES and ADS samples, respectively. Higher SCOD by sludge pretreatment enhanced performance of the MFCs and the electricity generation was linearly proportional to the SCOD removal, especially for ES. Copyright © 2014 Elsevier Ltd. All rights reserved.

Optimal sampling strategies for detecting zoonotic disease epidemics.

PubMed

Ferguson, Jake M; Langebrake, Jessica B; Cannataro, Vincent L; Garcia, Andres J; Hamman, Elizabeth A; Martcheva, Maia; Osenberg, Craig W

2014-06-01

The early detection of disease epidemics reduces the chance of successful introductions into new locales, minimizes the number of infections, and reduces the financial impact. We develop a framework to determine the optimal sampling strategy for disease detection in zoonotic host-vector epidemiological systems when a disease goes from below detectable levels to an epidemic. We find that if the time of disease introduction is known then the optimal sampling strategy can switch abruptly between sampling only from the vector population to sampling only from the host population. We also construct time-independent optimal sampling strategies when conducting periodic sampling that can involve sampling both the host and the vector populations simultaneously. Both time-dependent and -independent solutions can be useful for sampling design, depending on whether the time of introduction of the disease is known or not. We illustrate the approach with West Nile virus, a globally-spreading zoonotic arbovirus. Though our analytical results are based on a linearization of the dynamical systems, the sampling rules appear robust over a wide range of parameter space when compared to nonlinear simulation models. Our results suggest some simple rules that can be used by practitioners when developing surveillance programs. These rules require knowledge of transition rates between epidemiological compartments, which population was initially infected, and of the cost per sample for serological tests.

From fresh heterologous oocyte donation to autologous oocyte banking.

PubMed

Stoop, D

2012-01-01

Today, oocyte donation has become well established, giving rise to thousands of children born worldwide annually. The introduction of oocyte cryopreservation through vitrification allows the introduction of egg banking, improving the efficiency and comfort of oocyte donation. Moreover, the vitrification technique can now enable autologous donation of oocytes to prevent future infertility. We evaluated fresh heterologous oocyte donation in terms of obstetrical and perinatal outcome as well as of the reproductive outcome of past donors. We then evaluated the efficiency of a closed vitrification device and its clinical applications within ART. Thirdly, we evaluated the opinion of women with regard to preventive egg freezing and the efficiency of a human oocyte in relation to age. Oocyte donation is associated with an increased risk of first trimester bleeding and pregnancy induced hypertension. Donating oocytes does not seem to increase the likelihood for a later need of fertility treatment. The chance of an oocyte to result in live birth (utilization rate) in women <37 years old remains constant with a mean of 4.47%. A significant proportion of young women would consider safeguarding their reproductive potential through egg freezing or are at least open to the idea. The introduction of efficient oocyte cryopreservation has revolutionized oocyte donation through the establishment of eggbank donation. The technique also enables women to perform autologous donation after preventive oocyte storage in order to circumvent their biological clock.

[A system of introduction of the results of scientific research on hygiene into practical health care and national economics].

PubMed

Eksler, N D; Vishnevskaia, S S

1989-01-01

The country's socio-economic development necessitates further elaboration of new approaches to the introduction of hygienic research results into practice. The main criterion for choosing proper research techniques lies in their economy-type efficiency, both social, medical and economic. A new system of hygienic research introduction should be based on financial and economic stimuli, establishment of a network of inventive firms, as well as supported by an effective mechanisms of information feed-back with due account of health indices.

Synthesis of 8-Aryl-O-methylcyanidins and Their Usage for Dye-Sensitized Solar Cell Devices

PubMed Central

Kimura, Yuki; Oyama, Kin-ichi; Murata, Yasujiro; Wakamiya, Atsushi; Yoshida, Kumi

2017-01-01

Anthocyanins as natural pigments are colorful and environmentally compatible dyes for dye-sensitized solar cells (DSSCs). To increase the efficiency, we designed and synthesized unnatural O-methylflavonols and O-methylcyanidins that possess an aryl group at the 8-position. We synthesized per-O-methylquercetin from quercetin, then using selective demethylation prepared various O-methylquercetins. Using the Suzuki-Miyaura coupling reaction, 8-arylation of per-O-methylquercetin was achieved. Using a LiAlH4 reduction or Clemmensen reduction, these flavonols were transformed to the corresponding cyanidin derivatives in satisfactory yields. Using these dyes, we fabricated DSSCs, and their efficiency was investigated. The efficiency of tetra-O-methylflavonol was 0.31%. However, the introduction of the 8-aryl residue increased the efficiency to 1.04%. In comparison to these flavonols, O-methylcyanidins exhibited a lower efficiency of 0.05% to 0.52%. The introduction of the 8-aryl group into the cyanidin derivatives did not result in a remarkable increase in the efficiency. These phenomena may be due to the poor fit of the HOMO-LUMO level of the dyes to the TiO2 conduction band. PMID:28212330

Direct sample introduction-gas chromatography-mass spectrometry for the determination of haloanisole compounds in cork stoppers.

PubMed

Cacho, J I; Nicolás, J; Viñas, P; Campillo, N; Hernández-Córdoba, M

2016-12-02

A solventless analytical method is proposed for analyzing the compounds responsible for cork taint in cork stoppers. Direct sample introduction (DSI) is evaluated as a sample introduction system for the gas chromatography-mass spectrometry (GC-MS) determination of four haloanisoles (HAs) in cork samples. Several parameters affecting the DSI step, including desorption temperature and time, gas flow rate and other focusing parameters, were optimized using univariate and multivariate approaches. The proposed method shows high sensitivity and minimises sample handling, with detection limits of 1.6-2.6ngg -1 , depending on the compound. The suitability of the optimized procedure as a screening method was evaluated by obtaining decision limits (CCα) and detection capabilities (CCβ) for each analyte, which were found to be in 6.9-11.8 and 8.7-14.8ngg -1 , respectively, depending on the compound. Twenty-four cork samples were analysed, and 2,4,6-trichloroanisole was found in four of them at levels between 12.6 and 53ngg -1 . Copyright © 2016 Elsevier B.V. All rights reserved.

The effect of Ce3+ concentration and heat treatment on the luminescence efficiency of YAG phosphor

NASA Astrophysics Data System (ADS)

Valiev, Damir; Han, Tao; Vaganov, Vitaly; Stepanov, Sergey

2018-05-01

Y3Al5O12 (YAG) phosphor powders doped with Ce3+ at different concentrations (YAG:xCe, x = 0.02, 0.04, 0.06, 0.08, 0.1 wt%) were synthesized by the solid-state reaction method with the addition of BaF2 flux. The effects of cerium concentration and heat treatment on the luminescence efficiency of the YAG:Ce3+ phosphor were investigated. The introduction of Ce3+ ions leads to an increase in luminescent intensity of the YAG phosphor at 560 nm. The band at 530 nm is attributed to Ce3+ ions (optical transitions from the 4f-5d excited state). We assumed that such an increase in the luminescent intensity is due to the ability of Ce3+ to act as a luminescence sensitizer of intrinsic defects in YAG phosphor. The analysis of luminescence decay kinetics in the investigated samples has shown that the decay time in all samples does not differ significantly and equals τ ≈ 60 ± 3 ns. We showed experimentally that increasing the luminescence intensity has an effect observed with relatively low temperature treatment (T = 400 K). The nature of possible luminescence centers and the effect of low heat treatment on the luminescence properties of the powders are discussed.

Efficient immortalization of primary human cells by p16INK4a-specific short hairpin RNA or Bmi-1, combined with introduction of hTERT.

PubMed

Haga, Kei; Ohno, Shin-ichi; Yugawa, Takashi; Narisawa-Saito, Mako; Fujita, Masatoshi; Sakamoto, Michiie; Galloway, Denise A; Kiyono, Tohru

2007-02-01

Activation of telomerase is sufficient for immortalization of some types of human cells but additional factors may also be essential. It has been proposed that stress imposed by inadequate culture conditions induces senescence due to accumulation of p16(INK4a). Here, we present evidence that many human cell types undergo senescence by activation of the p16(INK4a)/Rb pathway, and that introduction of Bmi-1 can inhibit p16(INK4a) expression and extend the life span of human epithelial cells derived from skin, mammary gland and lung. Introduction of p16(INK4a)-specific short hairpin RNA, as well as Bmi-1, suppressed p16(INK4a) expression in human mammary epithelial cells without promoter methylation, and extended their life span. Subsequent introduction of hTERT, the telomerase catalytic subunit, into cells with low p16(INK4a) levels resulted in efficient immortalization of three cell types without crisis or growth arrest. The majority of the human mammary epithelial cells thus immortalized showed almost normal ploidy as judged by G-banding and spectral karyotyping analysis. Our data suggest that inhibition of p16(INK4a) and introduction of hTERT can immortalize many human cell types with little chromosomal instability.

Use of vancomycin silica stationary phase in packed capillary electrochromatography. II. Enantiomer separation of venlafaxine and O-desmethylvenlafaxine in human plasma.

PubMed

Fanali, S; Rudaz, S; Veuthey, J L; Desiderio, C

2001-06-01

A capillary electrochromatography method, using vancomycin chiral stationary phase packed capillary, was optimized for the simultaneous chiral separation of the antidepressant drug venlafaxine and its main active metabolite O-desmethylvenlafaxine. Simultaneous baseline enantiomeric separation of the two compounds was obtained using a mobile phase composed of 100 mM ammonium acetate buffer pH 6/water/acetonitrile (5:5:90, v/v). The electrokinetic injection for sample introduction provided a limit of quantitation for both the compounds of 0.05 microg/ml racemate concentration suitable for the analysis of venlafaxine and metabolite in biological samples. The acetonitrile mobile phase concentration was found to modulate the analytes elution times, the enantiomeric resolution and the efficiency of the separation. The column was tested for repeatability and linearity showing RSD values (%) in the range of 0.13-0.24, 2.47-3.66 and 1.35-2.50 for migration time, sample/internal standard peak area ratio and enantiomeric resolution, respectively and correlation coefficients higher than 0.9990. The method was applied to the analysis of clinical samples of patients under depression therapy showing a stereoselective metabolism for venlafaxine.

Comparative evaluation of ICP sample introduction systems to be used in the metabolite profiling of chlorine-containing pharmaceuticals via HPLC-ICP-MS.

PubMed

Klencsár, Balázs; Sánchez, Carlos; Balcaen, Lieve; Todolí, José; Lynen, Frederic; Vanhaecke, Frank

2018-05-10

A systematic evaluation of four different ICP sample introduction systems to be used in the context of metabolite profiling of chlorine-containing pharmaceuticals via HPLC-ICP-MS was carried out using diclofenac and its major metabolite, 4'-hydroxy-diclofenac, as model compounds. The strict requirements for GMP validation of chromatographic methods in the pharmaceutical industry were adhered to in this context. The final aim of this investigation is an extension of the applicability and validatability of HPLC-ICP-MS in the field of pharmaceutical R&D. Five different gradient programmes were tested while the baseline peak width (w b ), peak capacity (P), USP tailing factor (A s ) and USP signal-to-noise ratio (USP S/N) were determined as major indicators of the chromatographic performance and the values obtained were compared to the corresponding FDA recommendations (if applicable). Four different ICP-MS sample introductions systems were investigated involving two units typically working at higher flow rates (∼1.0 mL min -1 ) and another two systems working at lower flow rates (∼0.1 mL min -1 ). Optimal conditions with potential for applicability under GMP conditions were found at a mobile phase flow rate of 1.0 mL min -1 by using a pneumatic micro-flow LC nebulizer mounted onto a Peltier-cooled cyclonic spray chamber cooled to -1 °C for sample introduction. Under these conditions, HPLC-ICP-MS provided a chromatographic performance similar to that of HPLC with UV detection. The peak shape (USP tailing factor = 1.1-1.4) was significantly improved compared to that obtained with the Peltier-cooled Scott-type spray chamber. Two alternative sample introduction systems - a POINT ® and a High-Temperature Torch-Integrated Sample Introduction System (hTISIS) - were also tested at a flow rate of 0.1 mL min -1 using a chromatographic column with 1.0 mm ID. Although these systems allowed the peak shape to be improved compared to that obtained with the traditional Scott-type spray chamber, the limits of detection and of quantification achievable were strongly compromised due to the significantly lower sensitivity observed for Cl. In addition to a comparison of the aforementioned sample introduction systems, also the effect of spray chamber temperature was evaluated and it was demonstrated that proper temperature control plays an essential role in the optimization of HPLC-ICP-MS methods. Copyright © 2018 Elsevier B.V. All rights reserved.

A method for introduction of Al2O3 nanofiber into aluminum alloy

NASA Astrophysics Data System (ADS)

Chen, Yijin; Qin, He; Kurganova, Y. A.; Gaaze, V. K.

2018-04-01

Experimental samples of aluminum matrix composites (AMCs) reinforced with Al2O3 nanofibers were obtained. In order to increase the wettability in liquid phase combination conditions, it is proposed to use copper powder as a carrier of nanofiber. When studying the structure of the samples, a modifying effect of the introduction of reinforcement, demonstrated by grinding the grain, was revealed.

A risk-based predictive tool to prevent accidental introductions of nonindigenous marine species.

PubMed

Floerl, Oliver; Inglis, Graeme J; Hayden, Barbara J

2005-06-01

Preventing the introduction of nonindigenous species (NIS) is the most efficient way to avoid the costs and impacts of biological invasions. The transport of fouling species on ship hulls is an important vector for the introduction of marine NIS. We use quantitative risk screening techniques to develop a predictive tool of the abundance and variety of organisms being transported by ocean-going yachts. We developed and calibrated an ordinal rank scale of the abundance of fouling assemblages on the hulls of international yacht hulls arriving in New Zealand. Fouling ranks were allocated to 783 international yachts that arrived in New Zealand between 2002 and 2004. Classification tree analysis was used to identify relationships between the fouling ranks and predictor variables that described the maintenance and travel history of the yachts. The fouling ranks provided reliable indications of the actual abundance and variety of fouling assemblages on the yachts and identified most (60%) yachts that had fouling on their hulls. However, classification tree models explained comparatively little of the variation in the distribution of fouling ranks (22.1%), had high misclassification rates (approximately 43%), and low predictive power. In agreement with other studies, the best model selected the age of the toxic antifouling paint on yacht hulls as the principal risk factor for hull fouling. Our study shows that the transport probability of fouling organisms is the result of a complex suite of interacting factors and that large sample sizes will be needed for calibration of robust risk models.

Status of dye solar cell technology as a guideline for further research.

PubMed

Hinsch, Andreas; Veurman, Welmoed; Brandt, Henning; Jensen, Katrine Flarup; Mastroianni, Simone

2014-04-14

Recently, the first commercial dye solar cell (DSC) products based on the mesoscopic principle were successfully launched. Introduction to the market has been accompanied by a strong increase in patent applications in the field during the last four years, which is a good indication of further commercialization activity. Materials and cell concepts have been developed to such extent that easy uptake by industrial manufacturers is possible. The critical phase for broad market acceptance has therefore been reached, which implies focusing on standardization-related research topics. In parallel the number of scientific publications on DSC is growing further (>3500 since 2012), and the range of new or renewed fundamental topics is broadening. A recent example is the introduction of the perovskite mesoscopic cell, for which an efficiency of 14.1% has been certified. Thus, a growing divergence between market introduction and research could be the consequence. Herein, an attempt is made to show that such an unwanted divergence can be prevented, for example, by developing suitable reference-type cell and module concepts as well as manufacturing routes. An in situ cell manufacturing concept that can be applied to mesoscopic-based solar cells in a broader sense is proposed. As a guideline for future module concepts, recent results for large-area, glass-frit-sealed DSC modules from efficiency studies (6.6% active-area efficiency) and outdoor analysis are discussed. Electroluminescence measurements are introduced as a quality tool. Another important point that is addressed is sustainability, which affects both market introduction and the direction of fundamental research. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

"WhatsApp"ening in orthopedic care: a concise report from a 300-bedded tertiary care teaching center.

PubMed

Khanna, Vishesh; Sambandam, Senthil N; Gul, Arif; Mounasamy, Varatharaj

2015-07-01

Smartphones have emerged as essential tools providing assistance in patient care, monitoring, rehabilitation, communication, diagnosis, teaching, research and reference. Among innumerable communication apps, WhatsApp has been widely popular and cost effective. The aim of our study was to report the impact of introduction of a smartphone app "WhatsApp" as an intradepartmental communication tool on (1) awareness of patient-related information, (2) efficiency of the handover process and (3) duration of traditional morning handovers among orthopedic residents in a 300-bedded tertiary care teaching center. Written handovers and paging used for communication at our center led to occasional inefficiencies among residents. Widespread use, low cost, availability and double password protection (phone lock and WhatsApp lock) made WhatsApp's group conversation feature an ideal tool for intradepartmental patient-related communication. Twenty-five consecutive admissions before and after WhatsApp (BW, AW) were included in the study. Eight orthopedic residents attempted fifty randomly arranged questions based on the twenty-five patients in each study period. A null hypothesis that introduction of WhatsApp group would neither increase the awareness of patient-related information nor improve the efficiency of the handovers among residents was assumed. A significant improvement observed in scores obtained by residents in the AW group led to rejection of the null hypothesis. The residents also reported swifter and efficient handovers after the introduction of WhatsApp. Our results indicate that the introduction of a smartphone app "WhatsApp" as an intradepartmental communication tool can bring about an improvement in patient-related awareness, communication and handovers among orthopedic residents.

The Introduction of substitutional and non-substitutional dopants into MgB2 in high pressure/Temperature or non-equilibrium regimes

NASA Astrophysics Data System (ADS)

Sumption, Mike

2013-03-01

In an attempt to study the effect of doping of MgB2 under conditions leading to efficient doping, we used both an high temperature/high pressure induction furnace to dope into MgB2 bulks at temperatures up to 1600 C and 1500 Psi, and thin film, PLD multilayer and mixed layer film fabrication. The high temperature/high pressure formation was used to explore the solubility at high temperatures of various dopants, and the thin film formation was an attempt to use non-equilibrium conditions to inject dopants more effectively. The dopants used were C, Ti, and Zr. C was seen to reach a maximal level at 4 at% C site substituted into MgB2, as evidenced by EPMA and XRD results. Zr, of interest as a possible Mg site substitution in MgB2 was not seen to enter into the MgB2 phase (instead segregating) in the bulk high temperature/high pressure experiments, but was seen to enter in during PLD, as evidenced by STEM and XRD results. Ti additions were attempted in the high pressures and temperature rig, with some evidence for dopant introduction. Critical field measurements on the Zr doped samples where seen to suppress Bc2 for all except very low levels of Ti addition, presumably associated with the much greater doping efficiency. This work was supported by the U.S. Department of Energy, High Energy Physics university Grant No. DE-FG02-95ER40900

Inductively coupled plasma optical emission spectrometry for trace multi-element determination in vegetable oils, margarine and butter after stabilization with propan-1-ol and water

NASA Astrophysics Data System (ADS)

de Souza, Roseli M.; Mathias, Bárbara M.; da Silveira, Carmem Lúcia P.; Aucélio, Ricardo Q.

2005-06-01

The quantitative evaluation of trace elements in foodstuffs is of considerable interest due to the potential toxicity of many elements, and because the presence of some metallic species might affect the overall quality (flavor and stability) of these products. In the present work, an inductively coupled plasma optical emission spectrometric method has been developed for the determination of six elements (Cd, Co, Cr, Cu, Ni and Mn) in olive oil, soy oil, margarine and butter. Organic samples (oils and fats) were stabilized using propan-1-ol and water, which enabled long-time sample dispersion in the solution. This simple sample preparation procedure, together with an efficient sample introduction strategy (using a Meinhard K3 nebulizer and a twister cyclonic spray chamber), facilitated the overall analytical procedure, allowing quantification using calibration curves prepared with inorganic standards. Internal standardization (Sc) was used for correction of matrix effects and signal fluctuations. Good sensitivities with limits of detection in the ng g -1 range were achieved for all six elements. These sensitivities were appropriate for the intended application. The method was tested through the analysis of laboratory-fortified samples with good recoveries (between 91.3% and 105.5%).

Use of the Keele injector for sample introduction for gas chromatographic analysis of vinclozolin in lettuces.

PubMed

Shim, J H; Lee, Y S; Kim, M R; Lee, C J; Kim, I S

2003-10-10

We examined a Keele injector for sample introduction for gas chromatographic analysis of vinclozolin treated in lettuces. Samples in milligram quantity were introduced into a glass tube in a Keele injector at a gas chromatograph injection port. The glass tube was then crushed to allow the sample to carry onto a capillary column in a normal manner. The standard calibration curve for quantitative detection of vinclozolin was obtained by determining vinclozolin spiked in samples at variable concentrations. The calibration curve showed a linear response to vinclozolin ranging from 0.05 to 1.0 microg/g, giving a slope value of 174.8, the y-intercept value of -2.8146 and the mean r2-value of 0.9994. Limit of quantification for vinclozolin was 0.05 microg/g by this method, comparable to 0.01 microg/g by a normal injector. When samples treated previously with vinclozolin were determined by the Keele injector, vinclozolin was found to be about 30% lower as compared to a normal method, suggesting about 70% recovery of the spiked vinclozolin by the Keele injector. From these results, the Keele injector was suggested to be potential for sample introduction in gas chromatographic analysis of vinclozolin in lettuce samples.

Membrane Introduction Mass Spectrometry Combined with an Orthogonal Partial-Least Squares Calibration Model for Mixture Analysis.

PubMed

Li, Min; Zhang, Lu; Yao, Xiaolong; Jiang, Xingyu

2017-01-01

The emerging membrane introduction mass spectrometry technique has been successfully used to detect benzene, toluene, ethyl benzene and xylene (BTEX), while overlapped spectra have unfortunately hindered its further application to the analysis of mixtures. Multivariate calibration, an efficient method to analyze mixtures, has been widely applied. In this paper, we compared univariate and multivariate analyses for quantification of the individual components of mixture samples. The results showed that the univariate analysis creates poor models with regression coefficients of 0.912, 0.867, 0.440 and 0.351 for BTEX, respectively. For multivariate analysis, a comparison to the partial-least squares (PLS) model shows that the orthogonal partial-least squares (OPLS) regression exhibits an optimal performance with regression coefficients of 0.995, 0.999, 0.980 and 0.976, favorable calibration parameters (RMSEC and RMSECV) and a favorable validation parameter (RMSEP). Furthermore, the OPLS exhibits a good recovery of 73.86 - 122.20% and relative standard deviation (RSD) of the repeatability of 1.14 - 4.87%. Thus, MIMS coupled with the OPLS regression provides an optimal approach for a quantitative BTEX mixture analysis in monitoring and predicting water pollution.

Antibacterial performance of nano polypropylene filter media containing nano-TiO2 and clay particles

NASA Astrophysics Data System (ADS)

Shafiee, Sara; Zarrebini, Mohammad; Naghashzargar, Elham; Semnani, Dariush

2015-10-01

Disinfection and elimination of pathogenic microorganisms from liquid can be achieved by filtration process using antibacterial filter media. The advent of nanotechnology has facilitated the introduction of membranes consisting of nano-fiber in filtration operations. The melt electro-spun fibers due to their extremely small diameters are used in the production of this particular filtration medium. In this work, antibacterial polypropylene filter medium containing clay particles and nano-TiO2 were made using melt electro-spun technology. Antibacterial performance of polypropylene nano-filters was evaluated using E. coli bacteria. Additionally, filtration efficiency of the samples in terms fiber diameter, filter porosity, and fiber distribution using image processing technique was determined. Air permeability and dust aerosol tests were conducted to establish the suitability of the samples as a filter medium. It was concluded that as far as antibacterial property is concerned, nano-fibers filter media containing clay particles are preferential to similar media containing TiO2 nanoparticles.

Method for detection of long-lived radioisotopes in small biochemical samples

DOEpatents

Turteltaub, K.W.; Vogel, J.S.; Felton, J.S.; Gledhill, B.L.; Davis, J.C.

1994-11-22

Disclosed is a method for detection of long-lived radioisotopes in small biochemical samples, comprising: a. selecting a biological host in which radioisotopes are present in concentrations equal to or less than those in the ambient biosphere, b. preparing a long-lived radioisotope labeled reactive chemical specie, c. administering the chemical specie to the biologist host in doses sufficiently low to avoid significant overt damage to the biological system, d. allowing a period of time to elapse sufficient for dissemination and interaction of the chemical specie with the host throughout the biological system of the host, e. isolating a reacted fraction of the biological substance from the host in a manner sufficient to avoid contamination of the substance from extraneous sources, f. converting the fraction of biological substance by suitable means to a material which efficiently produces charged ions in at least one of several possible ion sources without introduction of significant isotopic fractionation, and, g. measuring the radioisotope concentration in the material by means of direct isotopic counting. 5 figs.

Method for detection of long-lived radioisotopes in small biochemical samples

DOEpatents

Turteltaub, Kenneth W.; Vogel, John S.; Felton, James S.; Gledhill, Barton L.; Davis, Jay C.

1994-01-01

Disclosed is a method for detection of long-lived radioisotopes in small bio-chemical samples, comprising: a. selecting a biological host in which radioisotopes are present in concentrations equal to or less than those in the ambient biosphere, b. preparing a long-lived radioisotope labeled reactive chemical specie, c. administering said chemical specie to said biologist host in doses sufficiently low to avoid significant overt damage to the biological system thereof, d. allowing a period of time to elapse sufficient for dissemination and interaction of said chemical specie with said host throughout said biological system of said host, e. isolating a reacted fraction of the biological substance from said host in a manner sufficient to avoid contamination of said substance from extraneous sources, f. converting said fraction of biological substance by suitable means to a material which efficiently produces charged ions in at least one of several possible ion sources without introduction of significant isotopic fractionation, and, g. measuring the radioisotope concentration in said material by means of direct isotopic counting.

ZrO2-modified mesoporous nanocrystalline TiO2-xNx as efficient visible light photocatalysts.

PubMed

Wang, Xinchen; Yu, Jimmy C; Chen, Yilin; Wu, Ling; Fu, Xianzhi

2006-04-01

Mesoporous nanocrystalline TiO2-xNx and TiO2-xNx/ZrO2 visible-light photocatalysts have been prepared by a sol-gel method. The photocatalysts were characterized by XRD, N2 adsorption-desorption, TEM, XPS, UV/Vis, and IR spectroscopy. The photocatalytic activity of the samples was evaluated by the decomposition of ethylene in air under visible light (lambda > 450 nm) illumination. Results revealed that nitrogen was doped into the lattice of TiO2 by the thermal treatment of NH3-adsorbed TiO2 hydrous gels, converting the TiO2 into a visible-light responsive catalyst. The introduction of ZrO2 into TiO2-xNx considerably inhibits the undesirable crystal growth during calcination. Consequently, the ZrO2-modified TiO2-xNx displays higher porosity, higher specific surface area, and an improved thermal stability over the corresponding unmodified TiO2-xNx samples.

Efficiency in the United States electric industry: Transaction costs, deregulation, and governance structures

NASA Astrophysics Data System (ADS)

Peterson, Carl

Transaction costs economics (TCE) posits that firms have an incentive to bypass the market mechanisms in situations where the cost of using the market is prohibitive. Vertical integration, among other governance mechanisms, can be used to minimize the transactions costs associated with the market mechanism. The study analyses different governance mechanisms, which range from complete vertical integration to the use of market mechanisms, for firms in the US electric sector. This sector has undergone tremendous change in the past decade including the introduction of retail competition in some jurisdictions. As a result of the push toward deregulation of the industry, vertically integration, while still significant in the sector, has steadily been replaced by alternative governance structures. Using a sample of 136 investor-owned electric utilities that reported data the US Federal Energy Regulatory Commission between 1996 and 2002, this study estimates firm level efficiency using Data Envelopment Analysis (DEA) and relates these estimates to governance structure and public policies. The analysis finds that vertical integration is positively related to firm efficiency, although in a non-linear fashion suggesting that hybrid governance structures tend to be associated with lower efficiency scores. In addition, while some evidence is found for negative short-term effects on firm efficiency from the choice to deregulate, this result is sensitive to DEA model choice. Further, competition in retail markets is found to be positively related to firm level efficiency, but the retreat from deregulation, which occurred after 2000, is negatively associated with firm-level efficiency. These results are important in the ongoing academic and public policy debates concerning deregulation of the electric section and indicate that vertical economies remain in the industry, but that competition has provided incentives for improving firm level efficiency.

Hydrodynamic injection with pneumatic valving for microchip electrophoresis with total analyte utilization

PubMed Central

Sun, Xuefei; Kelly, Ryan T.; Danielson, William F.; Agrawal, Nitin; Tang, Keqi; Smith, Richard D.

2011-01-01

A novel hydrodynamic injector that is directly controlled by a pneumatic valve has been developed for reproducible microchip capillary electrophoresis (CE) separations. The poly(dimethylsiloxane) (PDMS) devices used for evaluation comprise a separation channel, a side channel for sample introduction, and a pneumatic valve aligned at the intersection of the channels. A low pressure (≤ 3 psi) applied to the sample reservoir is sufficient to drive sample into the separation channel. The rapidly actuated pneumatic valve enables injection of discrete sample plugs as small as ~100 pL for CE separation. The injection volume can be easily controlled by adjusting the intersection geometry, the solution back pressure and the valve actuation time. Sample injection could be reliably operated at different frequencies (< 0.1 Hz to >2 Hz) with good reproducibility (peak height relative standard deviation ≤ 3.6%) and no sampling biases associated with the conventional electrokinetic injections. The separation channel was dynamically coated with a cationic polymer, and FITC-labeled amino acids were employed to evaluate the CE separation. Highly efficient (≥ 7.0 × 103 theoretical plates for the ~2.4 cm long channel) and reproducible CE separations were obtained. The demonstrated method has numerous advantages compared with the conventional techniques, including repeatable and unbiased injections, little sample waste, high duty cycle, controllable injected sample volume, and fewer electrodes with no need for voltage switching. The prospects of implementing this injection method for coupling multidimensional separations, for multiplexing CE separations and for sample-limited bioanalyses are discussed. PMID:21520147

Optimal Inspection of Imports to Prevent Invasive Pest Introduction.

PubMed

Chen, Cuicui; Epanchin-Niell, Rebecca S; Haight, Robert G

2018-03-01

The United States imports more than 1 billion live plants annually-an important and growing pathway for introduction of damaging nonnative invertebrates and pathogens. Inspection of imports is one safeguard for reducing pest introductions, but capacity constraints limit inspection effort. We develop an optimal sampling strategy to minimize the costs of pest introductions from trade by posing inspection as an acceptance sampling problem that incorporates key features of the decision context, including (i) simultaneous inspection of many heterogeneous lots, (ii) a lot-specific sampling effort, (iii) a budget constraint that limits total inspection effort, (iv) inspection error, and (v) an objective of minimizing cost from accepted defective units. We derive a formula for expected number of accepted infested units (expected slippage) given lot size, sample size, infestation rate, and detection rate, and we formulate and analyze the inspector's optimization problem of allocating a sampling budget among incoming lots to minimize the cost of slippage. We conduct an empirical analysis of live plant inspection, including estimation of plant infestation rates from historical data, and find that inspections optimally target the largest lots with the highest plant infestation rates, leaving some lots unsampled. We also consider that USDA-APHIS, which administers inspections, may want to continue inspecting all lots at a baseline level; we find that allocating any additional capacity, beyond a comprehensive baseline inspection, to the largest lots with the highest infestation rates allows inspectors to meet the dual goals of minimizing the costs of slippage and maintaining baseline sampling without substantial compromise. © 2017 Society for Risk Analysis.

Baculoviral delivery of CRISPR/Cas9 facilitates efficient genome editing in human cells

PubMed Central

Hindriksen, Sanne; Bramer, Arne J.; Truong, My Anh; Vromans, Martijn J. M.; Post, Jasmin B.; Verlaan-Klink, Ingrid; Snippert, Hugo J.; Lens, Susanne M. A.

2017-01-01

The CRISPR/Cas9 system is a highly effective tool for genome editing. Key to robust genome editing is the efficient delivery of the CRISPR/Cas9 machinery. Viral delivery systems are efficient vehicles for the transduction of foreign genes but commonly used viral vectors suffer from a limited capacity in the genetic information they can carry. Baculovirus however is capable of carrying large exogenous DNA fragments. Here we investigate the use of baculoviral vectors as a delivery vehicle for CRISPR/Cas9 based genome-editing tools. We demonstrate transduction of a panel of cell lines with Cas9 and an sgRNA sequence, which results in efficient knockout of all four targeted subunits of the chromosomal passenger complex (CPC). We further show that introduction of a homology directed repair template into the same CRISPR/Cas9 baculovirus facilitates introduction of specific point mutations and endogenous gene tags. Tagging of the CPC recruitment factor Haspin with the fluorescent reporter YFP allowed us to study its native localization as well as recruitment to the cohesin subunit Pds5B. PMID:28640891

Low- Z polymer sample supports for fixed-target serial femtosecond X-ray crystallography

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

Feld, Geoffrey K.; Heymann, Michael; Benner, W. Henry

X-ray free-electron lasers (XFELs) offer a new avenue to the structural probing of complex materials, including biomolecules. Delivery of precious sample to the XFEL beam is a key consideration, as the sample of interest must be serially replaced after each destructive pulse. The fixed-target approach to sample delivery involves depositing samples on a thin-film support and subsequent serial introduction via a translating stage. Some classes of biological materials, including two-dimensional protein crystals, must be introduced on fixed-target supports, as they require a flat surface to prevent sample wrinkling. A series of wafer and transmission electron microscopy (TEM)-style grid supports constructedmore » of low- Z plastic have been custom-designed and produced. Aluminium TEM grid holders were engineered, capable of delivering up to 20 different conventional or plastic TEM grids using fixed-target stages available at the Linac Coherent Light Source (LCLS). As proof-of-principle, X-ray diffraction has been demonstrated from two-dimensional crystals of bacteriorhodopsin and three-dimensional crystals of anthrax toxin protective antigen mounted on these supports at the LCLS. In conclusion, the benefits and limitations of these low- Z fixed-target supports are discussed; it is the authors' belief that they represent a viable and efficient alternative to previously reported fixed-target supports for conducting diffraction studies with XFELs.« less

Affordable in-house antiretroviral drug resistance assay with good performance in non-subtype B HIV-1

PubMed Central

Wallis, Carole L.; Papathanasopoulos, Maria A.; Lakhi, Shabir; Karita, Etienne; Kamali, Anatoli; Kaleebu, Pontiano; Sanders, Eduard; Anzala, Omu; Bekker, Linda-Gail; Stevens, Gwynn; Rinke de Wit, Tobias F.; Stevens, Wendy

2010-01-01

The introduction of antiretroviral therapy in resource-poor settings is effective in suppressing HIV-1 replication and prolonging life of infected individuals. This has led to a demand for affordable HIV-1 drug resistance assays, since treatment failure due to development of drug resistance is common. This study developed and evaluated an affordable “in–house” genotyping assay to monitor HIV-1 drug resistance in Africa, particularly South Africa. An “in-house” assay using automated RNA extraction, and subtype C specific PCR and sequencing primers was developed and successfully evaluated 396 patient samples (viral load ranges 1,000->1.6million RNA copies/ml). The “in-house” assay was validated by comparing sequence data and drug resistance profiles from 90 patient and 10 external quality control samples to data from the ViroSeqTM HIV-1 Genotyping kit. The “in-house” assay was more efficient, amplifying all 100 samples, compared to 91 samples using Viroseq. The “in house” sequences were 99.2%) homologous to the ViroSeq sequences, and identical drug resistance mutation profiles were observed in 96 samples. Furthermore, the “in-house” assay genotyped 260 of 295 samples from seven African sites, where 47% were non-subtype C. Overall, the newly validated “in-house” drug resistance assay is suited for use in Africa as it overcomes the obstacle of subtype diversity. PMID:19917318

Affordable in-house antiretroviral drug resistance assay with good performance in non-subtype B HIV-1.

PubMed

Wallis, Carole L; Papathanasopoulos, Maria A; Lakhi, Shabir; Karita, Etienne; Kamali, Anatoli; Kaleebu, Pontiano; Sanders, Eduard; Anzala, Omu; Bekker, Linda-Gail; Stevens, Gwynn; de Wit, Tobias F Rinke; Stevens, Wendy

2010-02-01

The introduction of antiretroviral (ARV) therapy in resource-poor settings is effective in suppressing HIV-1 replication and prolonging life of infected individuals. This has led to a demand for affordable HIV-1 drug resistance assays, since treatment failure due to development of drug resistance is common. This study developed and evaluated an affordable "in-house" genotyping assay to monitor HIV-1 drug resistance in Africa, particularly South Africa. An "in-house" assay using automated RNA extraction, and subtype C specific PCR and sequencing primers was developed and successfully evaluated 396 patient samples (viral load ranges 1000-1.6 million RNA copies/ml). The "in-house" assay was validated by comparing sequence data and drug resistance profiles from 90 patient and 10 external quality control samples to data from the ViroSeq HIV-1 Genotyping kit. The "in-house" assay was more efficient, amplifying all 100 samples, compared to 91 samples using Viroseq. The "in house" sequences were 99.2% homologous to the ViroSeq sequences, and identical drug resistance mutation profiles were observed in 96 samples. Furthermore, the "in-house" assay genotyped 260 of 295 samples from seven African sites, where 47% were non-subtype C. Overall, the newly validated "in-house" drug resistance assay is suited for use in Africa as it overcomes the obstacle of subtype diversity. 2009 Elsevier B.V. All rights reserved.

Evaluation of the availability of bound analyte for passive sampling in the presence of mobile binding matrix.

PubMed

Xu, Jianqiao; Huang, Shuyao; Jiang, Ruifen; Cui, Shufen; Luan, Tiangang; Chen, Guosheng; Qiu, Junlang; Cao, Chenyang; Zhu, Fang; Ouyang, Gangfeng

2016-04-21

Elucidating the availability of the bound analytes for the mass transfer through the diffusion boundary layers (DBLs) adjacent to passive samplers is important for understanding the passive sampling kinetics in complex samples, in which the lability factor of the bound analyte in the DBL is an important parameter. In this study, the mathematical expression of lability factor was deduced by assuming a pseudo-steady state during passive sampling, and the equation indicated that the lability factor was equal to the ratio of normalized concentration gradients between the bound and free analytes. Through the introduction of the mathematical expression of lability factor, the modified effective average diffusion coefficient was proven to be more suitable for describing the passive sampling kinetics in the presence of mobile binding matrixes. Thereafter, the lability factors of the bound polycyclic aromatic hydrocarbons (PAHs) with sodium dodecylsulphate (SDS) micelles as the binding matrixes were figured out according to the improved theory. The lability factors were observed to decrease with larger binding ratios and smaller micelle sizes, and were successfully used to predict the mass transfer efficiencies of PAHs through DBLs. This study would promote the understanding of the availability of bound analytes for passive sampling based on the theoretical improvements and experimental assessments. Copyright © 2016 Elsevier B.V. All rights reserved.

Understanding arsenic incorporation in CdTe with atom probe tomography

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

Burton, G. L.; Diercks, D. R.; Ogedengbe, O. S.

Overcoming the open circuit voltage deficiency in Cadmium Telluride (CdTe) photovoltaics may be achieved by increasing p-type doping while maintaining or increasing minority carrier lifetimes. Here, routes to higher doping efficiency using arsenic are explored through an atomic scale understanding of dopant incorporation limits and activation in molecular beam epitaxy grown CdTe layers. Atom probe tomography reveals spatial segregation into nanometer scale clusters containing > 60 at% As for samples with arsenic incorporation levels greater than 7-8 x 10^17 cm-3. The presence of arsenic clusters was accompanied by crystal quality degradation, particularly the introduction of arsenic-enriched extended defects. Post-growth annealingmore » treatments are shown to increase the size of the As precipitates and the amount of As within the precipitates.« less

Recent advances in monolithic columns for protein and peptide separation by capillary liquid chromatography.

PubMed

Liang, Yu; Zhang, Lihua; Zhang, Yukui

2013-03-01

Capillary liquid chromatography (cLC) has great potential for protein and peptide separation, with advantages of high efficiency, high resolution, low sample consumption, and high sensitivity when coupled with mass spectrometry. In recent years, monoliths have been widely used as the stationary phases for capillary columns, owing to easy preparation, high permeability, fast mass transfer, and low backpressure. This review summarizes recent advances (2007-2012) in monolithic columns for protein and peptide separation by cLC. After a brief introduction on the preparation of monolithic capillary columns, the emphasis of this review is focused on the recent application of such columns for protein and peptide separation by cLC. Furthermore, the challenges and potential hot points of monolithic capillary columns in the future are discussed.

Western pond turtle: Biology, sampling techniques, inventory and monitoring, conservation, and management: Northwest Fauna No. 7

USGS Publications Warehouse

Bury, R.B.; Welsh, Hartwell H.; Germano, David J.; Ashton, Donald T.

2012-01-01

One of only two native, freshwater turtle species in the western United States, western pond turtles are declining in portions of their original range. Declines are mostly due to habitat loss, introduction of non-native species, pollution, and lack of connectivity among populations. USGS zoologist R. Bruce Bury and colleagues from the U.S. Forest Service, California State University, and other agencies compiled and edited a new review and field manual of this charismatic species. Objectives were to determine its current distribution and abundance, summarize and evaluate population features, review techniques to detect population and habitat changes, and improve monitoring for long-term trends. Methods described in the manual should improve consistency, efficiency, and accuracy of survey data, resulting in improved management and conservation efforts.

Understanding arsenic incorporation in CdTe with atom probe tomography

DOE PAGES

Burton, G. L.; Diercks, D. R.; Ogedengbe, O. S.; ...

2018-03-22

Overcoming the open circuit voltage deficiency in Cadmium Telluride (CdTe) photovoltaics may be achieved by increasing p-type doping while maintaining or increasing minority carrier lifetimes. Here, routes to higher doping efficiency using arsenic are explored through an atomic scale understanding of dopant incorporation limits and activation in molecular beam epitaxy grown CdTe layers. Atom probe tomography reveals spatial segregation into nanometer scale clusters containing > 60 at% As for samples with arsenic incorporation levels greater than 7-8 x 10^17 cm-3. The presence of arsenic clusters was accompanied by crystal quality degradation, particularly the introduction of arsenic-enriched extended defects. Post-growth annealingmore » treatments are shown to increase the size of the As precipitates and the amount of As within the precipitates.« less

Introduction and Program Finder

EPA Pesticide Factsheets

Explore promising practices and successful models that state and local officials can use to reduce greenhouse gas emissions by bringing energy efficiency and renewable energy in low-income communities.

New efficient stimuli for evoking frequency-specific auditory steady-state responses.

PubMed

Stürzebecher, Ekkehard; Cebulla, Mario; Elberling, Claus; Berger, Thomas

2006-06-01

ASSR is a promising tool for the objective frequency-specific assessment of hearing thresholds in children. The stimulus generally used for ASSR recording (single amplitude-modulated carrier) only activates a small area on the basilar membrane. Therefore, the response amplitude is low. A stimulus with a broader frequency spectrum can be composed by adding several cosines whose frequency intervals comply with the desired stimulus repetition rate. Compensation of the travelling wave delay on the basilar membrane is possible with a stimulus of this type. Through this, a better synchronization of the neural response can be obtained and, as a result, higher response amplitudes can be expected, particularly for low-frequency stimuli. The additional introduction of a frequency offset enables the use of a q-sample test for the response detection, especially important at 500 Hz. The results of investigations carried out on a large group of normally hearing test subjects have confirmed the efficiency of this stimulus design. The new stimuli lead to significantly improved ASSRs with higher SNRs and thus higher detection rates and shorter detection times.

History of Significant Vehicle and Fuel Introductions in the United States

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

Shirk, Matthew; Alleman, Teresa; Melendez, Margo

This is one of a series of reports produced as a result of the Co-Optimization of Fuels & Engines (Co-Optima) project, a Department of Energy (DOE)-sponsored multi-agency project initiated to accelerate the introduction of affordable, scalable, and sustainable biofuels and high-efficiency, low-emission vehicle engines. The simultaneous fuels and vehicles research and development is designed to deliver maximum energy savings, emissions reduction, and on-road performance.

Socialization in Pigtailed Macaques (Macaca nemestrina)

PubMed Central

WORLEIN, JULIE M.; KROEKER, ROSE; LEE, GRACE H.; THOM, JINHEE P.; BELLANCA, RITA U.; CROCKETT, CAROLYN M.

2018-01-01

In response to new emphasis by regulatory agencies regarding socialization, behavioral management programs are allocating greater resources to maximize socialization opportunities for laboratory primates. Information regarding predictors of compatibility and risk of injury for all laboratory-housed species of macaques are needed to make social introductions and pairings as efficient and safe as possible. This study presents data on 674 pairs of pigtailed macaques (Macaca nemestrina) at the Washington National Primate Research Center over a 7-year period. During pair introduction, behavior was monitored while the degree of tactile contact was gradually increased. Based on observed behavior, pairs were assigned a behavioral introduction score (BIS), rating the quality of their interactions for each day of introduction. Animals deemed compatible, based on the BIS and technologist judgment, were allowed to progress to continuous contact with no staff present. A small proportion of animals deemed compatible at introduction was later separated for subsequent incompatibility or aggression; these proportions were higher in full contact compared to protected contact pairings. Of 674 pairs, 75% were deemed compatible at introduction in protected contact; 86 of these pairs were later transitioned to full contact with 98% compatibility. Predictors of decreased compatibility assessed during protected contact introductions included age (adult pairs were less compatible), the BIS on the last day of introduction, and aggression or injury during the introductory period. Predictors of injuries during the protected contact introduction process included: aggression on the first day of introduction, a negative BIS on the first or last day of introduction, and, surprisingly, the presence of grooming on the first day of introduction. Injuries during both introduction and subsequent pairing in protected contact were rare; however, injury rates increased significantly during full-contact pairing. These findings underscore the necessity of species-specific data to guide decision-making during the social introduction process. PMID:27109591

A Planar Microfluidic Mixer Based on Logarithmic Spirals

PubMed Central

Scherr, Thomas; Quitadamo, Christian; Tesvich, Preston; Park, Daniel Sang-Won; Tiersch, Terrence; Hayes, Daniel; Choi, Jin-Woo; Nandakumar, Krishnaswamy

2013-01-01

A passive, planar micromixer design based on logarithmic spirals is presented. The device was fabricated using polydimethylsiloxane soft photolithography techniques, and mixing performance was characterized via numerical simulation and fluorescent microscopy. Mixing efficiency initially declined as Reynolds number increased, and this trend continued until a Reynolds number of 15 where a minimum was reached at 53%. Mixing efficiency then began to increase reaching a maximum mixing efficiency of 86% at Re = 67. Three-dimensional simulations of fluid mixing in this design were compared to other planar geometries such as the Archimedes spiral and Meandering-S mixers. The implementation of logarithmic curvature offers several unique advantages that enhance mixing, namely a variable cross-sectional area and a logarithmically varying radius of curvature that creates 3-D Dean vortices. These flow phenomena were observed in simulations with multilayered fluid folding and validated with confocal microscopy. This design provides improved mixing performance over a broader range of Reynolds numbers than other reported planar mixers, all while avoiding external force fields, more complicated fabrication processes, and the introduction of flow obstructions or cavities that may unintentionally affect sensitive or particulate-containing samples. Due to the planar design requiring only single-step lithographic features, this compact geometry could be easily implemented into existing micro-total analysis systems requiring effective rapid mixing. PMID:23956497

A planar microfluidic mixer based on logarithmic spirals

NASA Astrophysics Data System (ADS)

Scherr, Thomas; Quitadamo, Christian; Tesvich, Preston; Sang-Won Park, Daniel; Tiersch, Terrence; Hayes, Daniel; Choi, Jin-Woo; Nandakumar, Krishnaswamy; Monroe, W. Todd

2012-05-01

A passive, planar micromixer design based on logarithmic spirals is presented. The device was fabricated using polydimethylsiloxane soft photolithography techniques, and mixing performance was characterized via numerical simulation and fluorescent microscopy. Mixing efficiency initially declined as the Reynolds number increased, and this trend continued until a Reynolds number of 15 where a minimum was reached at 53%. Mixing efficiency then began to increase reaching a maximum mixing efficiency of 86% at Re = 67. Three-dimensional (3D) simulations of fluid mixing in this design were compared to other planar geometries such as the Archimedes spiral and Meandering-S mixers. The implementation of logarithmic curvature offers several unique advantages that enhance mixing, namely a variable cross-sectional area and a logarithmically varying radius of curvature that creates 3D Dean vortices. These flow phenomena were observed in simulations with multilayered fluid folding and validated with confocal microscopy. This design provides improved mixing performance over a broader range of Reynolds numbers than other reported planar mixers, all while avoiding external force fields, more complicated fabrication processes and the introduction of flow obstructions or cavities that may unintentionally affect sensitive or particulate-containing samples. Due to the planar design requiring only single-step lithographic features, this compact geometry could be easily implemented into existing micro-total analysis systems requiring effective rapid mixing.

Improving the Efficiency and Effectiveness of Grading through the Use of Computer-Assisted Grading Rubrics

ERIC Educational Resources Information Center

Anglin, Linda; Anglin, Kenneth; Schumann, Paul L.; Kaliski, John A.

2008-01-01

This study tests the use of computer-assisted grading rubrics compared to other grading methods with respect to the efficiency and effectiveness of different grading processes for subjective assignments. The test was performed on a large Introduction to Business course. The students in this course were randomly assigned to four treatment groups…

An Analysis of Teachers' General Tendency to Procrastinate, Perception of Professional Efficiency/Self Efficiency and Altruism

ERIC Educational Resources Information Center

Dilmac, Bulent

2009-01-01

Introduction: Teaching as a profession requires the possession of certain characteristics. Teachers accept their students as individuals and cherish them. Teachers' reasons behind their choice to become a teacher are believed to be professional affection, spiritual satisfaction and a perception of teaching as the ideal profession. Furthermore the…

The Prevalence and Efficiency of Investment in Pre-Entry Coaching in Russia

ERIC Educational Resources Information Center

Prakhov, Ilya

2017-01-01

This paper examines the prevalence and the costs of pre-entry coaching programs before and after the introduction of the Unified State Examination in Russia. The efficiency of private tutoring under the new standardized university admission procedures is estimated. It is argued that the main types of pre-entry coaching are still in demand, however…

Implementation of Markerless Augmented Reality Technology Based on Android to Introduction Lontara in Marine Society

NASA Astrophysics Data System (ADS)

Jumarlis, Mila; Mirfan, Mirfan

2018-05-01

Local language learning had been leaving by people especially young people had affected technology advances so that involved lack of interest to learn culture especially local language. So required interactive and interest learning media for introduction Lontara. This research aims to design and implement augmented reality on introduction Lontara on mobile device especially android. Application of introduction Lontara based on Android was designed by Vuforia and Unity. Data collection method were observation, interview, and literature review. That data was analysed for being information. The system was designed by Unified Modeling Language (UML). The method used is a marker. The test result found that application of Augmented Reality on introduction Lontara based on Android could improve public interest for introducing local language particularly young people in learning about Lontara because of using technology. Application of introduction of Lontara based on Android used augmented reality occurred sound and how to write Lontara with animation. This application could be running without an internet connection, so that its used more efficient and could maximize from user.

Research Designs for Intervention Research with Small Samples II: Stepped Wedge and Interrupted Time-Series Designs.

PubMed

Fok, Carlotta Ching Ting; Henry, David; Allen, James

2015-10-01

The stepped wedge design (SWD) and the interrupted time-series design (ITSD) are two alternative research designs that maximize efficiency and statistical power with small samples when contrasted to the operating characteristics of conventional randomized controlled trials (RCT). This paper provides an overview and introduction to previous work with these designs and compares and contrasts them with the dynamic wait-list design (DWLD) and the regression point displacement design (RPDD), which were presented in a previous article (Wyman, Henry, Knoblauch, and Brown, Prevention Science. 2015) in this special section. The SWD and the DWLD are similar in that both are intervention implementation roll-out designs. We discuss similarities and differences between the SWD and DWLD in their historical origin and application, along with differences in the statistical modeling of each design. Next, we describe the main design characteristics of the ITSD, along with some of its strengths and limitations. We provide a critical comparative review of strengths and weaknesses in application of the ITSD, SWD, DWLD, and RPDD as small sample alternatives to application of the RCT, concluding with a discussion of the types of contextual factors that influence selection of an optimal research design by prevention researchers working with small samples.

Research Designs for Intervention Research with Small Samples II: Stepped Wedge and Interrupted Time-Series Designs

PubMed Central

Ting Fok, Carlotta Ching; Henry, David; Allen, James

2015-01-01

The stepped wedge design (SWD) and the interrupted time-series design (ITSD) are two alternative research designs that maximize efficiency and statistical power with small samples when contrasted to the operating characteristics of conventional randomized controlled trials (RCT). This paper provides an overview and introduction to previous work with these designs, and compares and contrasts them with the dynamic wait-list design (DWLD) and the regression point displacement design (RPDD), which were presented in a previous article (Wyman, Henry, Knoblauch, and Brown, 2015) in this Special Section. The SWD and the DWLD are similar in that both are intervention implementation roll-out designs. We discuss similarities and differences between the SWD and DWLD in their historical origin and application, along with differences in the statistical modeling of each design. Next, we describe the main design characteristics of the ITSD, along with some of its strengths and limitations. We provide a critical comparative review of strengths and weaknesses in application of the ITSD, SWD, DWLD, and RPDD as small samples alternatives to application of the RCT, concluding with a discussion of the types of contextual factors that influence selection of an optimal research design by prevention researchers working with small samples. PMID:26017633

Study on the lifetime of Mo/Si multilayer optics with pulsed EUV-source at the ETS

NASA Astrophysics Data System (ADS)

Schürmann, Mark; Yulin, Sergiy; Nesterenko, Viatcheslav; Feigl, Torsten; Kaiser, Norbert; Tkachenko, Boris; Schürmann, Max C.

2011-06-01

As EUV lithography is on its way into production stage, studies of optics contamination and cleaning under realistic conditions become more and more important. Due to this fact an Exposure Test Stand (ETS) has been constructed at XTREME technologies GmbH in collaboration with Fraunhofer IOF and with financial support of Intel Corporation. This test stand is equipped with a pulsed DPP source and allows for the simultaneous exposure of several samples. In the standard set-up four samples with an exposed area larger than 35 mm2 per sample can be exposed at a homogeneous intensity of 0.25 mW/mm2. A recent update of the ETS allows for simultaneous exposures of two samples with intensities up to 1.0 mW/mm2. The first application of this alternative set-up was a comparative study of carbon contamination rates induced by EUV radiation from the pulsed source with contamination rates induced by quasicontinuous synchrotron radiation. A modified gas-inlet system allows for the introduction of a second gas to the exposure chamber. This possibility was applied to investigate the efficiency of EUV-induced cleaning with different gas mixtures. In particular the enhancement of EUV-induced cleaning by addition of a second gas to the cleaning gas was studied.

Single-step solubilization of milk samples with N,N-dimethylformamide for inductively coupled plasma-mass spectrometry analysis and classification based on their elemental composition.

PubMed

Azcarate, Silvana M; Savio, Marianela; Smichowski, Patricia; Martinez, Luis D; Camiña, José M; Gil, Raúl A

2015-10-01

A single-step procedure for trace elements analysis of milk samples is presented. Solubilization with small amounts of dymethylformamide (DMF) was assayed prior to inductively coupled plasma mass spectrometry (ICPMS) detection with a high efficiency sample introduction system. All main instrumental conditions were optimized in order to readily introduce the samples without matrix elimination. In order to assess and mitigate matrix effects in the determination of As, Cd, Co, Cu, Eu, Ga, Gd, Ge, Mn, Mo, Nb, Nd, Ni, Pb, Pr, Rb, Sm, S, Sr, Ta, Tb, V, Zn, and Zr, matrix matching calibration with (103)Rh as internal standard (IS) was performed. The obtained limits of detection were between 0.68 (Tb) and 30 (Zn) μg L(-1). For accuracy verification, certified Skim milk powder reference material (BCR 063R) was employed. The developed method was applied to trace elements analysis of commercially available milks. Principal components analysis was used to correlate the content of trace metals with the kind of milk, obtaining a classification according to adults, baby or baby fortified milks. The outcomes highlight a simple and fast approach that could be trustworthy for routine analysis, quality control and traceability of milks. Copyright © 2015 Elsevier B.V. All rights reserved.

Ensemble-Biased Metadynamics: A Molecular Simulation Method to Sample Experimental Distributions

PubMed Central

Marinelli, Fabrizio; Faraldo-Gómez, José D.

2015-01-01

We introduce an enhanced-sampling method for molecular dynamics (MD) simulations referred to as ensemble-biased metadynamics (EBMetaD). The method biases a conventional MD simulation to sample a molecular ensemble that is consistent with one or more probability distributions known a priori, e.g., experimental intramolecular distance distributions obtained by double electron-electron resonance or other spectroscopic techniques. To this end, EBMetaD adds an adaptive biasing potential throughout the simulation that discourages sampling of configurations inconsistent with the target probability distributions. The bias introduced is the minimum necessary to fulfill the target distributions, i.e., EBMetaD satisfies the maximum-entropy principle. Unlike other methods, EBMetaD does not require multiple simulation replicas or the introduction of Lagrange multipliers, and is therefore computationally efficient and straightforward in practice. We demonstrate the performance and accuracy of the method for a model system as well as for spin-labeled T4 lysozyme in explicit water, and show how EBMetaD reproduces three double electron-electron resonance distance distributions concurrently within a few tens of nanoseconds of simulation time. EBMetaD is integrated in the open-source PLUMED plug-in (www.plumed-code.org), and can be therefore readily used with multiple MD engines. PMID:26083917

Clipboard

ERIC Educational Resources Information Center

Timmons, Virginia G.

1977-01-01

Thorough advance planning will eliminate much of the clutter and the mud hazards associated with the introduction of ceramics. Provides some helpful suggestions for teaching ceramics in an efficient and tidy fashion. (Author/RK)

Introduction of Transplant Registry Unified Management Program 2 (TRUMP2): scripts for TRUMP data analyses, part I (variables other than HLA-related data).

PubMed

Atsuta, Yoshiko

2016-01-01

Collection and analysis of information on diseases and post-transplant courses of allogeneic hematopoietic stem cell transplant recipients have played important roles in improving therapeutic outcomes in hematopoietic stem cell transplantation. Efficient, high-quality data collection systems are essential. The introduction of the Second-Generation Transplant Registry Unified Management Program (TRUMP2) is intended to improve data quality and more efficient data management. The TRUMP2 system will also expand possible uses of data, as it is capable of building a more complex relational database. The construction of an accessible data utilization system for adequate data utilization by researchers would promote greater research activity. Study approval and management processes and authorship guidelines also need to be organized within this context. Quality control of processes for data manipulation and analysis will also affect study outcomes. Shared scripts have been introduced to define variables according to standard definitions for quality control and improving efficiency of registry studies using TRUMP data.

Determination of mercury compounds in fish by microwave-assisted extraction and liquid chromatography-vapor generation-inductively coupled plasma mass spectrometry

NASA Astrophysics Data System (ADS)

Chiou, Chwei-Sheng; Jiang, Shiuh-Jen; Kumar Danadurai, K. Suresh

2001-07-01

A method employing a vapor generation system and LC combined with inductively coupled plasma mass spectrometry (LC-ICP-MS) is presented for the determination of mercury in biological tissues. An open vessel microwave digestion system was used to extract the mercury compounds from the sample matrix. The efficiency of the mobile phase, a mixture of L-cysteine and 2-mercaptoethanol, was evaluated for LC separation of inorganic mercury [Hg(II)], methylmercury (methyl-Hg) and ethylmercury (ethyl-Hg). The sensitivity, detection limits and repeatability of the liquid chromatography (LC) ICP-MS system with a vapor generator were comparable to, or better than, that of an LC-ICP-MS system with conventional pneumatic nebulization, or other sample introduction techniques. The experimental detection limits for various mercury species were in the range of 0.05-0.09 ng ml -1 Hg, based on peak height. The proposed method was successfully applied to the determination of mercury compounds in a swordfish sample purchased from the local market. The accuracy of the method was evaluated by analyzing a marine biological certified reference material (DORM-2, NRCC).

Photon ratchet intermediate band solar cells

NASA Astrophysics Data System (ADS)

Yoshida, M.; Ekins-Daukes, N. J.; Farrell, D. J.; Phillips, C. C.

2012-06-01

In this paper, we propose an innovative concept for solar power conversion—the "photon ratchet" intermediate band solar cell (IBSC)—which may increase the photovoltaic energy conversion efficiency of IBSCs by increasing the lifetime of charge carriers in the intermediate state. The limiting efficiency calculation for this concept shows that the efficiency can be increased by introducing a fast thermal transition of carriers into a non-emissive state. At 1 sun, the introduction of a "ratchet band" results in an increase of efficiency from 46.8% to 48.5%, due to suppression of entropy generation.

76 FR 13242 - Change in Postal Prices

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-10

[email protected] (electronic filing assistance). SUPPLEMENTARY INFORMATION: Table of Contents I. Introduction II. Notice of Filings III. Ordering Paragraphs I. Introduction On March 1, 2011, the Commission... Postal Service-branded parcel box designed to contain product samples and other advertising material from...

Relationship between Eu{sup 3+} reduction and glass polymeric structure in Al{sub 2}O{sub 3}-modified borate glasses under air atmosphere

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

Jiao, Qing; Yu, Xue; Xu, Xuhui

2013-06-15

The reduction of Eu{sup 3+} to Eu{sup 2+} is realized efficiently in Eu{sub 2}O{sub 3}-doped borate glasses prepared under air condition by melting-quenching method. Luminescent spectra show an increasing tendency of Eu{sup 2+} emission with increasing Al{sub 2}O{sub 3} concentration in B{sub 2}O{sub 3}–Na{sub 2}O glasses. It is interesting that significant enhancement appeared of Eu{sup 2+} luminescence in the Al{sub 2}O{sub 3}-rich sample comparing to the samples of Al{sub 2}O{sub 3} less than 6 mol%. FTIR and Raman scattering measurements indicated that some new vibration modes assigned to the low-polymerized structure groups decomposed from the slight Al{sub 2}O{sub 3} dopantmore » samples. These results demonstrated that the polymerization of the glass structure decreased with increasing incorporation of Al{sub 2}O{sub 3} into the borate glasses, linking to the efficiency of Eu{sup 3+} self-reduction in air at high temperature. - graphical abstract: A novel europium valence reduction phenomenon occurred in Al{sub 2}O{sub 3} modified borate glasses, FTIR and Raman measurements revealed that high polymeric groups were destroyed to low polymery structures with Al{sub 2}O{sub 3} addition. - Highlights: • The efficient reduction of Eu{sup 3+} to Eu{sup 2+} is observed in the B{sub 2}O{sub 3}–Na{sub 2}O glasses. • Eu{sup 2+} luminescence is significant enhanced in the Al{sub 2}O{sub 3}-rich glasses. • The introduction of Al{sub 2}O{sub 3} changed the network structure of the borate glasses. • High polymeric borate groups in the glass matrix may be destroyed to the lower ones.« less

Code TESLA for Modeling and Design of High-Power High-Efficiency Klystrons

DTIC Science & Technology

2011-03-01

CODE TESLA FOR MODELING AND DESIGN OF HIGH - POWER HIGH -EFFICIENCY KLYSTRONS * I.A. Chernyavskiy, SAIC, McLean, VA 22102, U.S.A. S.J. Cooke, B...and multiple-beam klystrons as high - power RF sources. These sources are widely used or proposed to be used in accelerators in the future. Comparison...of TESLA modelling results with experimental data for a few multiple-beam klystrons are shown. INTRODUCTION High - power and high -efficiency

Transmission of Rift Valley fever virus from European-breed lambs to Culex pipiens mosquitoes.

PubMed

Vloet, Rianka P M; Vogels, Chantal B F; Koenraadt, Constantianus J M; Pijlman, Gorben P; Eiden, Martin; Gonzales, Jose L; van Keulen, Lucien J M; Wichgers Schreur, Paul J; Kortekaas, Jeroen

2017-12-01

Rift Valley fever virus (RVFV) is a mosquito-borne bunyavirus of the genus Phlebovirus that is highly pathogenic to ruminants and humans. The disease is currently confined to Africa and the Arabian Peninsula, but globalization and climate change may facilitate introductions of the virus into currently unaffected areas via infected animals or mosquitoes. The consequences of such an introduction will depend on environmental factors, the availability of susceptible ruminants and the capacity of local mosquitoes to transmit the virus. We have previously demonstrated that lambs native to the Netherlands are highly susceptible to RVFV and we here report the vector competence of Culex (Cx.) pipiens, the most abundant and widespread mosquito species in the country. Vector competence was first determined after artificial blood feeding of laboratory-reared mosquitoes using the attenuated Clone 13 strain. Subsequently, experiments with wild-type RVFV and mosquitoes hatched from field-collected eggs were performed. Finally, the transmission of RVFV from viremic lambs to mosquitoes was studied. Artificial feeding experiments using Clone 13 demonstrated that indigenous, laboratory-reared Cx. pipiens mosquitoes are susceptible to RVFV and that the virus can be transmitted via their saliva. Experiments with wild-type RVFV and mosquitoes hatched from field-collected eggs confirmed the vector competence of Cx. pipiens mosquitoes from the Netherlands. To subsequently investigate transmission of the virus under more natural conditions, mosquitoes were allowed to feed on RVFV-infected lambs during the viremic period. We found that RVFV is efficiently transmitted from lambs to mosquitoes, although transmission was restricted to peak viremia. Interestingly, in the mosquito-exposed skin samples, replication of RVFV was detected in previously unrecognized target cells. We here report the vector competence of Cx. pipiens mosquitoes from the Netherlands for RVFV. Both laboratory-reared mosquitoes and well as those hatched from field-collected eggs were found to be competent vectors. Moreover, RVFV was transmitted efficiently from indigenous lambs to mosquitoes, although the duration of host infectivity was found to be shorter than previously assumed. Interestingly, analysis of mosquito-exposed skin samples revealed previously unidentified target cells of the virus. Our findings underscore the value of including natural target species in vector competence experiments.

Analysis of chemical warfare agents by gas chromatography-mass spectrometry: methods for their direct detection and derivatization approaches for the analysis of their degradation products

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

Valdez, Carlos A.; Leif, Roald N.; Hok, Saphon

Abstract Chemical warfare agents (CWAs) are unarguably one of the most feared toxic substances produced by mankind. Their inception in conventional warfare can be traced as far back as the Middle Ages but their full breakthrough as central players in bellic conflicts was not realized until World War I. Since then, more modern CWAs along with efficient methods for their manufacture have emerged and violently shaped the way modern warfare and diplomatic relations are conducted. Owing to their mass destruction ability, counter methods to mitigate their impact appeared almost immediately on par with their development. These efforts have focused onmore » their efficient destruction, development of medical countermeasures and their detection by modern analytical chemistry methods. The following review seeks to provide the reader with a broad introduction on their direct detection by gas chromatography-mass spectrometry (GC-MS) and the various sample derivatization methods available for the analysis of their degradation products. The review concentrates on three of the main CWA classes and includes the nerve agents, the blistering agents and lastly, the incapacitating agents. Each section begins with a brief introduction of the CWA along with discussions of reports dealing with their detection in the intact form by GC-MS. Furthermore, as products arising from their degradation carry as much importance as the agents themselves in the field of forensic analysis, the available derivatization methods of these species are presented for each CWA highlighting some examples from our lab in the Forensic Science Center at the Lawrence Livermore National Laboratory.« less

Analysis of chemical warfare agents by gas chromatography-mass spectrometry: methods for their direct detection and derivatization approaches for the analysis of their degradation products

DOE PAGES

Valdez, Carlos A.; Leif, Roald N.; Hok, Saphon; ...

2017-07-25

Abstract Chemical warfare agents (CWAs) are unarguably one of the most feared toxic substances produced by mankind. Their inception in conventional warfare can be traced as far back as the Middle Ages but their full breakthrough as central players in bellic conflicts was not realized until World War I. Since then, more modern CWAs along with efficient methods for their manufacture have emerged and violently shaped the way modern warfare and diplomatic relations are conducted. Owing to their mass destruction ability, counter methods to mitigate their impact appeared almost immediately on par with their development. These efforts have focused onmore » their efficient destruction, development of medical countermeasures and their detection by modern analytical chemistry methods. The following review seeks to provide the reader with a broad introduction on their direct detection by gas chromatography-mass spectrometry (GC-MS) and the various sample derivatization methods available for the analysis of their degradation products. The review concentrates on three of the main CWA classes and includes the nerve agents, the blistering agents and lastly, the incapacitating agents. Each section begins with a brief introduction of the CWA along with discussions of reports dealing with their detection in the intact form by GC-MS. Furthermore, as products arising from their degradation carry as much importance as the agents themselves in the field of forensic analysis, the available derivatization methods of these species are presented for each CWA highlighting some examples from our lab in the Forensic Science Center at the Lawrence Livermore National Laboratory.« less

Electrothermal vaporization of mineral acid solutions in inductively coupled plasma mass spectrometry: comparison with sample nebulization

NASA Astrophysics Data System (ADS)

Mora, Juan; Gras, Luis; van Veen, Eric H.; de Loos-Vollebregt, Margaretha T. C.

1999-06-01

The analytical behaviour of an electrothermal vaporization (ETV) device for the introduction of mineral acid solutions in inductively coupled plasma mass spectrometry (ICP-MS) was evaluated. Water, nitric acid, hydrochloric acid, perchloric acid and sulphuric acid in concentrations within the 0.05-1.0 mol l-1 range were studied. For all the acids tested, increasing the acid concentration increases the ion signal and deteriorates the precision. The magnitude of the signal enhancement depends on the analyte and on the acid considered. Acid solutions give rise to ion signals that are between 2 and 10 times higher than those with water. Among the acids tested, sulphuric acid provides the highest signals. The addition of palladium reduces matrix effects due to the acids and increases the signal in ETV ICP-MS. In comparison with conventional sample nebulization (CS), the ETV sample introduction system provides higher sensitivities (between 2 and 20 times higher) at the same acid concentration. The magnitude of this improvement is similar to that obtained with a microwave desolvation system (MWDS). The ETV sample introduction system gives rise to the lowest background signals from matrix-induced species. Due to this fact, the limits of detection (LODs) obtained for the isotopes affected by any interference are lower for ETV sample introduction than those obtained with the CS and the MWDS. For the isotopes that do not suffer from matrix-induced spectral interferences, the ETV gives rise to LODs higher than those obtained with the CS. For these isotopes the lowest LODs are obtained with MWDS.

Short torch design for direct liquid sample introduction using conventional and micro-nebulizers for plasma spectrometry

DOEpatents

Montaser, Akbar [Potomac, MD; Westphal, Craig S [Landenberg, PA; Kahen, Kaveh [Montgomery Village, MD; Rutkowski, William F [Arlington, VA

2008-01-08

An apparatus and method for providing direct liquid sample introduction using a nebulizer are provided. The apparatus and method include a short torch having an inner tube and an outer tube, and an elongated adapter having a cavity for receiving the nebulizer and positioning a nozzle tip of the nebulizer a predetermined distance from a tip of the outer tube of the short torch. The predetermined distance is preferably about 2-5 mm.

MIL-100-Fe derived N-doped Fe/Fe3C@C electrocatalysts for efficient oxygen reduction reaction

NASA Astrophysics Data System (ADS)

Guo, Dakai; Han, Sancan; Wang, Jiacheng; Zhu, Yufang

2018-03-01

N-doped porous Fe/Fe3C@C electrocatalysts were prepared by the pyrolysis of the hexamethylenetetramine (HMT)-incorporated MIL-100-Fe at different temperatures (700-1000 °C) under N2 atmosphere. Rotary evaporation of MIL-100-Fe and HMT solution could make more N-enriched HMT molecules enter into the pores of MIL-100-Fe, thus improving nitrogen contents of the final pyrolyzed samples. All pyrolyzed samples show porous textures with middle specific surface areas. The X-ray photoelectron spectroscopy (XPS) results demonstrate the successful introduction of N atoms into carbon framework. Sample Fe-N2-800 prepared by annealing the precursors with the HMT/MIL-100-Fe weight ratio of 2 at 800 °C exhibits the best electrocatalytic activity towards the oxygen reduction reaction (ORR) in terms of onset potential and current density because of high graphitic N and pyridinic N content. The enwrapped Fe/Fe3C nanoparticles and Fe-Nx active sites in these samples could also boost the ORR activity synergistically. Moreover, sample Fe-N2-800 demonstrates a dominant four electron reduction process, as well as excellent long-term operation stability and methanol crossover resistance. Thus, the N-doped Fe/Fe3C@C composites derived from the HMT-incorporated MIL-100-Fe are promising electrocatalysts to replace Pt/C for ORR in practical applications.

Introduction to Acoustics

NASA Astrophysics Data System (ADS)

Rossing, Thomas

This brief introduction may help to persuade the reader that acoustics covers a wide range of interesting topics. It is impossible to cover all these topics in a single handbook, but we have attempted to include a sampling of hot topics that represent current acoustical research, both fundamental and applied.

Estimating the rate of biological introductions: Lessepsian fishes in the Mediterranean.

PubMed

Belmaker, Jonathan; Brokovich, Eran; China, Victor; Golani, Daniel; Kiflawi, Moshe

2009-04-01

Sampling issues preclude the direct use of the discovery rate of exotic species as a robust estimate of their rate of introduction. Recently, a method was advanced that allows maximum-likelihood estimation of both the observational probability and the introduction rate from the discovery record. Here, we propose an alternative approach that utilizes the discovery record of native species to control for sampling effort. Implemented in a Bayesian framework using Markov chain Monte Carlo simulations, the approach provides estimates of the rate of introduction of the exotic species, and of additional parameters such as the size of the species pool from which they are drawn. We illustrate the approach using Red Sea fishes recorded in the eastern Mediterranean, after crossing the Suez Canal, and show that the two approaches may lead to different conclusions. The analytical framework is highly flexible and could provide a basis for easy modification to other systems for which first-sighting data on native and introduced species are available.

Hydrodynamic injection with pneumatic valving for microchip electrophoresis with total analyte utilization

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

Sun, Xuefei; Kelly, Ryan T.; Danielson, William F.

2011-04-26

A novel hydrodynamic injector that is directly controlled by a pneumatic valve has been developed for reproducible microchip capillary electrophoresis (CE) separations. The poly(dimethylsiloxane) (PDMS) devices used for evaluation comprise a separation channel, a side channel for sample introduction, and a pneumatic valve aligned at the intersection of the channels. A low pressure (≤ 3 psi) applied to the sample reservoir is sufficient to drive sample into the separation channel. The rapidly actuated pneumatic valve enables injection of discrete sample plugs as small as ~100 pL for CE separation. The injection volume can be easily controlled by adjusting the intersectionmore » geometry, the solution back pressure and the valve actuation time. Sample injection could be reliably operated at different frequencies (< 0.1 Hz to >2 Hz) with good reproducibility (peak height relative standard deviation ≤ 3.6%) and no sampling biases associated with the conventional electrokinetic injections. The separation channel was dynamically coated with a cationic polymer, and FITC-labeled amino acids were employed to evaluate the CE separation. Highly efficient (≥ 7.0 × 103 theoretical plates for the ~2.4 cm long channel) and reproducible CE separations were obtained. The demonstrated method has numerous advantages compared with the conventional techniques, including repeatable and unbiased injections, no sample waste, high duty cycle, controllable injected sample volume, and fewer electrodes with no need for voltage switching. The prospects of implementing this injection method for coupling multidimensional separations, for multiplexing CE separations and for sample-limited bioanalyses are discussed.« less

Characterizing the temporal patterns of avian influenza virus introduction into Japan by migratory birds

PubMed Central

ONUMA, Manabu; KAKOGAWA, Masayoshi; YANAGISAWA, Masae; HAGA, Atsushi; OKANO, Tomomi; NEAGARI, Yasuko; OKANO, Tsukasa; GOKA, Koichi; ASAKAWA, Mitsuhiko

2017-01-01

The objectives of the present study were to observe the temporal pattern of avian influenza virus (AIV) introduction into Japan and to determine which migratory birds play an important role in introducing AIV. In total, 19,407 fecal samples from migratory birds were collected at 52 sites between October 2008 and May 2015. Total nucleic acids extracted from the fecal samples were subjected to reverse transcription loop–mediated isothermal amplification to detect viral RNA. Species identification of host migratory birds was conducted by DNA barcoding for positive fecal samples. The total number of positive samples was 352 (prevalence, 1.8%). The highest prevalence was observed in autumn migration, and a decrease in prevalence was observed. During autumn migration, central to southern Japan showed a prevalence higher than the overall prevalence. Thus, the main AIV entry routes may involve crossing the Sea of Japan and entry through the Korean Peninsula. Species identification was successful in 221 of the 352 positive samples. Two major species sequences were identified: the Mallard/Eastern Spot-billed duck group (115 samples; 52.0%) and the Northern pintail (61 samples; 27.6%). To gain a better understanding of the ecology of AIV in Japan and the introduction pattern of highly pathogenic avian influenza viruses, information regarding AIV prevalence by species, the prevalence of hatch-year migratory birds, migration patterns and viral subtypes in fecal samples using egg inoculation and molecular-based methods in combination is required. PMID:28484128

Dielectric and Ferroelectric Properties of SrTiO3-Bi0.5Na0.5TiO3-BaAl0.5Nb0.5O3 Lead-Free Ceramics for High-Energy-Storage Applications.

PubMed

Yan, Fei; Yang, Haibo; Lin, Ying; Wang, Tong

2017-11-06

Pulsed capacitors require high-recoverable energy-storage density (W rec ) and high energy-storage efficiency (η), which can be realized through the selection and adjustment of the composition. In this work, (1 - x)SrTiO 3 -x(0.95Bi 0.5 Na 0.5 TiO 3 -0.05BaAl 0.5 Nb 0.5 O 3 ) [(1 - x)ST-x(BNT-BAN)] ceramics were successfully prepared via the pressureless solid-state reaction method. The dielectric constant increases gradually with the introduction of BNT-BAN and obtains a maximum value of 3430 with the composition of 0.4ST-0.6(BNT-BAN) at 100 Hz, which is 10.39 times higher than that of the pure ST sample (∼330). Dispersive relaxor behaviors and ferroelectric performances can be enhanced with the introduction of BNT-BAN. The composition of 0.5ST-0.5(BNT-BAN) exhibits a high W rec of 1.89 J/cm 3 as well as a high η of 77%. Therefore, the (1 - x)ST-x(BNT-BAN) systems are candidate materials for pulsed capacitor applications.

Survivability of intelligent transportation systems

DOT National Transportation Integrated Search

1999-10-01

Intelligent Transportation Systems (ITS) are being deployed around the world to improve the safety and efficiency of surface transportation through the application of advanced information technology. The introduction of ITS exposes the transportation...

Capillary sample introduction of polymerase chain reaction (PCR) products separated in ultrathin slab gels.

PubMed

Bullard, K M; Hietpas, P B; Ewing, A G

1998-01-01

Polymerase chain reaction (PCR) amplified short tandem repeat (STR) samples from the HUMVWF locus have been analyzed using a unique sample introduction and separation technique. A single capillary is used to transfer samples onto an ultrathin slab gel (57 microm thin). This ultrathin nondenaturing polyacrylamide gel is used to separate the amplified fragments, and laser-induced fluorescence with ethidium bromide is used for detection. The feasibility of performing STR analysis using this system has been investigated by examining the reproducibility for repeated samples. Reproducibility is examined by comparing the migration of the 14 and 17 HUMVWF alleles on three consecutive separations on the ultrathin slab gel. Using one locus, separations match in migration time with the two alleles 42 s apart for each of the three consecutive separations. This technique shows potential to increase sample throughput in STR analysis techniques although separation resolution still needs to be improved.

Silicon Solar Cell Efficiency Improvement Employing the Photoluminescent, Down-Shifting Effects of Carbon and CdTe Quantum Dots (Open Access Publisher’s Version)

DTIC Science & Technology

2016-03-21

ORIGINAL PAPER Silicon solar cell efficiency improvement employing the photoluminescent, down-shifting effects of carbon and CdTe quantum dots Elias...smaller influence on solar cell performance, they are con- sidered to be a more attractive option due to their afford- ability and minimal impact in the...Photovoltaics Solar cells Introduction There is a generalized trend to demonstrate higher solar cell efficiency with more affordable devices to promote

Towards Efficient Supercomputing: Searching for the Right Efficiency Metric

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

Hsu, Chung-Hsing; Kuehn, Jeffery A; Poole, Stephen W

2012-01-01

The efficiency of supercomputing has traditionally been in the execution time. In early 2000 s, the concept of total cost of ownership was re-introduced, with the introduction of efficiency measure to include aspects such as energy and space. Yet the supercomputing community has never agreed upon a metric that can cover these aspects altogether and also provide a fair basis for comparison. This paper exam- ines the metrics that have been proposed in the past decade, and proposes a vector-valued metric for efficient supercom- puting. Using this metric, the paper presents a study of where the supercomputing industry has beenmore » and how it stands today with respect to efficient supercomputing.« less

Introduction to Econophysics

NASA Astrophysics Data System (ADS)

Mantegna, Rosario N.; Stanley, H. Eugene

2007-08-01

Preface; 1. Introduction; 2. Efficient market hypothesis; 3. Random walk; 4. Lévy stochastic processes and limit theorems; 5. Scales in financial data; 6. Stationarity and time correlation; 7. Time correlation in financial time series; 8. Stochastic models of price dynamics; 9. Scaling and its breakdown; 10. ARCH and GARCH processes; 11. Financial markets and turbulence; 12. Correlation and anti-correlation between stocks; 13. Taxonomy of a stock portfolio; 14. Options in idealized markets; 15. Options in real markets; Appendix A: notation guide; Appendix B: martingales; References; Index.

Single-step azide introduction in proteins via an aqueous diazo transfer.

PubMed

van Dongen, Stijn F M; Teeuwen, Rosalie L M; Nallani, Madhavan; van Berkel, Sander S; Cornelissen, Jeroen J L M; Nolte, Roeland J M; van Hest, Jan C M

2009-01-01

The controlled introduction of azides in proteins provides targetable handles for selective protein manipulation. We present here an efficient diazo transfer protocol that can be applied in an aqueous solution, leading to the facile introduction of azides in the side chains of lysine residues and at the N-terminus of enzymes, e.g. horseradish peroxidase (HRP) and the red fluorescent protein DsRed. The effective introduction of azides was verified by mass spectrometry, after which the azido-proteins were used in Cu(I)-catalyzed [3 + 2] cycloaddition reactions. Azido-HRP retained its catalytic activity after conjugation of a small molecule. This modified protein could also be successfully immobilized on the surface of an acetylene-covered polymersome. Azido-DsRed was coupled to an acetylene-bearing protein allowing it to act as a fluorescent label, demonstrating the wide applicability of the diazo transfer procedure.

Petrographic manual : petrographic methods of examining hardened concrete, including introduction, sample preparation, questions and suggestions, and reading list.

DOT National Transportation Integrated Search

1991-01-01

This manual was undertaken to record for all persons wishing to do concrete petrography the petrographic procedures that have been found useful here at the Virginia Transportation Research Council. This interim report is made up of the introduction, ...

Chemical derivatization for enhancing sensitivity during LC/ESI-MS/MS quantification of steroids in biological samples: a review.

PubMed

Higashi, Tatsuya; Ogawa, Shoujiro

2016-09-01

Sensitive and specific methods for the detection, characterization and quantification of endogenous steroids in body fluids or tissues are necessary for the diagnosis, pathological analysis and treatment of many diseases. Recently, liquid chromatography/electrospray ionization-tandem mass spectrometry (LC/ESI-MS/MS) has been widely used for these purposes due to its specificity and versatility. However, the ESI efficiency and fragmentation behavior of some steroids are poor, which lead to a low sensitivity. Chemical derivatization is one of the most effective methods to improve the detection characteristics of steroids in ESI-MS/MS. Based on this background, this article reviews the recent advances in chemical derivatization for the trace quantification of steroids in biological samples by LC/ESI-MS/MS. The derivatization in ESI-MS/MS is based on tagging a proton-affinitive or permanently charged moiety on the target steroid. Introduction/formation of a fragmentable moiety suitable for the selected reaction monitoring by the derivatization also enhances the sensitivity. The stable isotope-coded derivatization procedures for the steroid analysis are also described. Copyright © 2015 Elsevier Ltd. All rights reserved.

Deep Keck u-Band Imaging of the Hubble Ultra Deep Field: A Catalog of z ~ 3 Lyman Break Galaxies

NASA Astrophysics Data System (ADS)

Rafelski, Marc; Wolfe, Arthur M.; Cooke, Jeff; Chen, Hsiao-Wen; Armandroff, Taft E.; Wirth, Gregory D.

2009-10-01

We present a sample of 407 z ~ 3 Lyman break galaxies (LBGs) to a limiting isophotal u-band magnitude of 27.6 mag in the Hubble Ultra Deep Field. The LBGs are selected using a combination of photometric redshifts and the u-band drop-out technique enabled by the introduction of an extremely deep u-band image obtained with the Keck I telescope and the blue channel of the Low Resolution Imaging Spectrometer. The Keck u-band image, totaling 9 hr of integration time, has a 1σ depth of 30.7 mag arcsec-2, making it one of the most sensitive u-band images ever obtained. The u-band image also substantially improves the accuracy of photometric redshift measurements of ~50% of the z ~ 3 LBGs, significantly reducing the traditional degeneracy of colors between z ~ 3 and z ~ 0.2 galaxies. This sample provides the most sensitive, high-resolution multi-filter imaging of reliably identified z ~ 3 LBGs for morphological studies of galaxy formation and evolution and the star formation efficiency of gas at high redshift.

Initial experience with the unrestricted introduction of sugammadex at a large academic medical center: a retrospective observational study examining postoperative mechanical ventilation and efficiency outcomes.

PubMed

Reilly-Shah, Vikas N O'; Lynde, Grant C; Mitchell, Matthew L; Maffeo, Carla L; Jabaley, Craig S; Wolf, Francis A

2018-05-30

Sugammadex can rapidly reverse deep neuromuscular blockade, but due to cost questions remain as to its optimal utilization. After introduction for unrestricted use at an academic medical center, we hypothesized that reductions would be demonstrated in the primary outcome of post-anesthesia care unit (PACU) mechanical ventilation (MV) and secondary outcomes of PACU length of stay (LOS), and emergence time (surgery end to anesthesia end time in PACU). We conducted a retrospective observational study of patients undergoing general anesthesia over a 12-month period. Using multiple variable penalized logistic regression in a one group before-and-after design, we compared categorized rates of PACU MV to examine the effect of sugammadex introduction following a post-hoc chart review to ascertain the reason for postoperative MV. Additionally, multiple variable linear regression was used to assess for differences in PACU LOS and emergence time within a propensity matched set of patients receiving neostigmine or sugammadex. 7,217 cases met inclusion criteria: 3,798 before and 3,419 after the introduction of sugammadex. The incidence of PACU MV was 2.3% before and 1.8% after (p=0.118). PACU MV due to residual neuromuscular blockade (rNMB) decreased from 0.63% to 0.20% (p=0.005). Ventilation due to other causes was unchanged. PACU LOS and emergence time were unchanged in a propensity matched set of 1,444 cases. We identified rNMB as an important contributor to PACU MV utilization and observed a significant decrease after sugammadex was introduced. The selected efficiency measures may not have been sufficiently granular to identify improvements following introduction.

Design study of a kinematic Stirling engine for dispered solar electric power systems

NASA Technical Reports Server (NTRS)

1980-01-01

The concept evaluation shows that the four cylinder double acting U type Stirling engine with annular regenerators is the most suitable engine type for the 15 kW solar application with respect to design, performance and cost. Results show that near term performance for a metallic Stirling engine is 42% efficiency. Further improved components show an impact on efficiency of the future metallic engine to 45%. Increase of heater temperature, through the introduction of ceramic components, contribute the greatest amount to achieve high efficiency goals. Future ceramic Stirling engines for solar applications show an efficiency of around 50%.

Analyzing the Efficiency of Introduction of the Intermittent Heating Mode

NASA Astrophysics Data System (ADS)

Anisimova, E.; Shcherbak, A.

2017-11-01

The efficiency of introduction of an optimal intermittent heating mode for a service center building in Chelyabinsk is estimated. The optimal intermittent heating mode ensures heat energy saving while maintaining the required microclimate parameters. The graphical dependencies of the amount of heat energy saving on the heat retention of the building and the outdoor air temperature are shown. The fundamental formulas which were the basis for calculating the periods of cooling, warming and expenditures of heat energy for the two heating modes are given. The literature on the issue is reviewed, the main points, advantages and disadvantages in the works of both Russian and foreign authors are revealed. The calculation was carried out in compliance with the modern state standards and regulatory documents. The capital costs of a system construction with an intermittent heating mode are determined.

[Automation and organization of technological process of urinalysis].

PubMed

Kolenkin, S M; Kishkun, A A; Kol'chenko, O L

2000-12-01

Results of introduction into practice of a working model of industrial technology of laboratory studies and KONE Specific Supra and Miditron M devices are shown as exemplified by clinical analysis of the urine. This technology helps standardize all stages and operations, improves the efficiency of quality control of laboratory studies, rationally organizes the work at all stages of the process, creates a system for permanent improvement of the efficiency of investigations at the preanalytical, analytical, and postanalytical stages of technological process of laboratory studies. As a result of introduction of this technology into laboratory practice, violations of quality criteria of clinical urinalysis decreased from 15 to 8% at the preanalytical stage and from 6 to 3% at the analytical stage. Automation of the analysis decreased the need in reagents 3-fold and improved the productivity at the analytical stage 4-fold.

[Methods of substances and organelles introduction in living cell for cell engineering technologies].

PubMed

Nikitin, V A

2007-01-01

We have presented the classification of more than 40 methods of genetic material, substances and organelles introduction into a living cell. Each of them has its characteristic advantages, disadvantages and limitations with respect to cell viability, transfer efficiency, general applicability, and technical requirements. It this article we have enlarged on the description of our developments of several new and improved approaches, methods and devices of the direct microinjection into a single cell and cell microsurgery with the help of glass micropipettes. The problem of low efficiency of mammalian cloning is discussed with emphasis on the necessity of expertizing of each step of single cell reconstruction to begin with microsurgical manipulations and necessity of the development of such methods of single cell resonstruction that could minimize the possible damage of the cell.

Genetic analysis of invasive Asian Black Carp (Mylopharyngodon piceus) in the Mississippi River Basin: evidence for multiple introductions

USGS Publications Warehouse

Hunter, Margaret E.; Nico, Leo G.

2015-01-01

Invasive Asian Black Carp (Mylopharyngodon piceus) have been present in USA aquaculture facilities since the 1980s and wild Black Carp have been found in the Mississippi River Basin since the early 1990s. This study characterizes the genetic diversity and relatedness of the Basin’s Black Carp and clarifies the introduction history. Analyses focused on three mitochondrial markers (control region, cytochrome-b, and 16S) and seven nuclear microsatellite markers (nDNA), using aquaculture and wild-caught samples collected in the upper and lower Mississippi Basin. Of the three mitochondrial haplotypes, two were shared between the aquaculture and wild populations, while a third was only present in upper Mississippi wild-caught specimens. Due to the presence of diploid and triploid fish, microsatellite markers were scored as pseudodominant and revealed low polymorphism (NA = 4.6, NA Ave = 1.5). Nuclear Bayesian clustering analyses identified two genetically distinct groups and four subclusters, each primarily composed of a unique haplotype. Samples from three aquaculture farms were assigned to group 1, while a fourth farm included samples from both groups 1 and 2. Wild-caught fish from the upper Basin were predominantly group 1, whereas wild samples from the lower Mississippi were assigned to both genetic groups. The presence of divergent haplotypes and distinct nDNA groups, along with geographic distribution patterns, indicate that wild populations in the basin likely resulted from multiple introductions. Genetic similarities between wild and captive populations support claims that aquaculture is the introduction source, but a shortage of samples and a history of repeated transfers among facilities obscure the precise pathway.

A study of the dynamics of Salmonella infection in turkey breeding, rearing and finishing houses with special reference to elimination, persistence and introduction of Salmonella.

PubMed

Mueller-Doblies, Doris; Carrique-Mas, Juan J; Davies, Robert H

2014-01-01

In this descriptive study, the dynamics of Salmonella infection of turkey flocks were investigated by repeated sampling of houses where Salmonella had been identified. The aim of the study was to identify the most common scenarios involved in elimination, persistence and introduction of Salmonella in the different branches of the turkey industry. Sixty-two houses on 34 turkey farms (comprising breeding, rearing and finishing farms) were sampled longitudinally, starting with the identification of a positive flock. A total of 117 follow-on flocks were tested and cleaning and disinfection (C&D) was assessed during 66 post-C&D visits. A total of 155 incidents (clearance, persistence or introduction of Salmonella) were recorded. Persistence was seen in 35.5% of incidents and was seen more frequently in breeding and rearing houses compared with finishing houses. Most persistence incidents were the result of insufficient C&D. Clearance was seen in 40% of incidents and was more often observed in finishing houses than in breeding or rearing houses. Introduction was seen in 24.5% of incidents and was more common in breeding and finishing flocks than in rearing flocks. Contamination of a house with Salmonella Typhimurium was more likely to be cleared compared with other serovars. The total number of positive samples found at a post-C&D visit was correlated with the probability of carry-over of infection, whereas the location of the positive samples seemed to be less important. Our highly sensitive post-C&D sampling method allowed us to predict a negative follow-on flock in most cases.

A Rapid, Low-Cost Method to Determine Travel Times at Managed Aquifer Recharge Operations Using Noble Gas Tracers

NASA Astrophysics Data System (ADS)

Moran, J. E.; Visser, A.; Singleton, M. J.; Esser, B. K.; Halliwell, M.; Hillegonds, D. J.

2012-12-01

Managed aquifer recharge is a key component for the sustainable use of surface water and groundwater in the arid western U.S. When recycled water is a recharge water source, subsurface residence time, required for bacteria and virus deactivation, is best verified by application of an extrinsic tracer. Desirable tracer properties include: no real or perceived health risk, inexpensive even for a large volume of tagged water, large dynamic range, efficient introduction, convenient sampling methods, and rapid, low-cost analysis. We have developed and tested a dissolved noble gas tracer technique ideally suited for tracing large water volumes at managed aquifer recharge facilities. In an application of the method at a water district's facilities in the San Francisco Bay area, Xenon was introduced into a 106 m3 pond over a period of 7 days using a 300 m length of gas-permeable silicone tubing. Samples from the pond, near-field shallow monitoring wells, and production wells about 400 m from the recharge pond were analyzed for dissolved Xe by noble gas membrane inlet mass spectrometry (NGMIMS). The NGMIMS uses a syringe pump, gas-permeable membrane inlet, and quadrupole residual gas analyzer for measurement of noble gas concentrations. Samples are collected in VOA vials, and analysis can be carried out in real-time, with a measurement uncertainty of about 5% for Xe. Tracer first appeared in a production well 136 days after starting the tracer introduction at 0.7% (C/C0) of the peak pond xenon concentration. The cost of the tracer is about US650/106 m3 water, and the NGMIMS was assembled with parts totaling approximately US50,000, making application of the tracer method feasible for most managed aquifer recharge projects. This project is part of the California State Water Resources Control Board Groundwater Ambient Monitoring and Assessment (GAMA) Program.

An efficient and highly stereoselective synthesis of new P-chiral 1,5-diphosphanylferrocene ligands and their use in enantioselective hydrogenation.

PubMed

Chen, Weiping; Roberts, J Stanley M; Whittall, John; Steiner, Alexander

2006-07-21

An efficient and highly stereoselective synthesis of P-chiral 1,5-diphosphanylferrocene ligands has been developed, and the introduction of P-chirality in ferrocene-based phosphine ligands enhances the enantioselective discrimination produced by the corresponding catalyst when matching of the planar chirality, the chirality at carbon and the chirality at phosphorus occurs.

Efficient generation of perfluoroalkyl radicals from sodium perfluoroalkanesulfinates and a hypervalent iodine(iii) reagent: mild, metal-free synthesis of perfluoroalkylated organic molecules.

PubMed

Sakamoto, Ryu; Kashiwagi, Hirotaka; Selvakumar, Sermadurai; Moteki, Shin A; Maruoka, Keiji

2016-07-06

This article describes an efficient method for the introduction of perfluoroalkyl groups into N-acrylamides, 2-isocyanides, olefins, and other heterocycles using perfluoroalkyl radicals that were generated from the reaction between sodium perfluoroalkanesulfinates and a hypervalent iodine(iii) reagent. This approach represents a simple, scalable perfluoroalkylation method under mild and metal-free conditions.

A testing-coverage software reliability model considering fault removal efficiency and error generation.

PubMed

Li, Qiuying; Pham, Hoang

2017-01-01

In this paper, we propose a software reliability model that considers not only error generation but also fault removal efficiency combined with testing coverage information based on a nonhomogeneous Poisson process (NHPP). During the past four decades, many software reliability growth models (SRGMs) based on NHPP have been proposed to estimate the software reliability measures, most of which have the same following agreements: 1) it is a common phenomenon that during the testing phase, the fault detection rate always changes; 2) as a result of imperfect debugging, fault removal has been related to a fault re-introduction rate. But there are few SRGMs in the literature that differentiate between fault detection and fault removal, i.e. they seldom consider the imperfect fault removal efficiency. But in practical software developing process, fault removal efficiency cannot always be perfect, i.e. the failures detected might not be removed completely and the original faults might still exist and new faults might be introduced meanwhile, which is referred to as imperfect debugging phenomenon. In this study, a model aiming to incorporate fault introduction rate, fault removal efficiency and testing coverage into software reliability evaluation is developed, using testing coverage to express the fault detection rate and using fault removal efficiency to consider the fault repair. We compare the performance of the proposed model with several existing NHPP SRGMs using three sets of real failure data based on five criteria. The results exhibit that the model can give a better fitting and predictive performance.

Characterization of the thin layer photocatalysts TiO2 and V2O5- and Fe2O3- doped TiO2 prepared by the sol-gel method

NASA Astrophysics Data System (ADS)

Loc Luu, Cam; Nguyen, Quoc Tuan; Thoang Ho, Si; Nguyen, Tri

2013-09-01

The catalysts TiO2 and TiO2 doped with Fe and V were prepared using the sol-gel method. TiO2-modified samples were obtained in the form of a thick film on pyrex glass sticks and tubes and were used as catalysts in the gas phase photo-oxidation of p-xylene. The physico-chemical characteristics of the catalysts were determined using the methods of Brunauer-Emmett-Teller adsorption, x-ray diffraction, and infrared, ultraviolet and visible and Raman spectroscopies. The experimental results show that the introduction of V did not expand the region of light absorption, but slightly reduced the size of the TiO2 particles, and reduced the number of OH-groups, which should decrease the photocatalytic activity and efficiency of the obtained catalysts compared to those of pure TiO2. The Fe-doped TiO2 samples, in contrast, are characterized by an extension of the spectrum of photon absorption to the visible region with wavenumbers λ up to 464 nm and the values of their band gap energy decreased to lower quantities (up to 2.67 eV), therefore they should have higher catalytic activity and conversion efficiency of p-xylene in the visible region than the original sample. For these catalysts, a combined utilization of radiation by ultraviolet (λ = 365 nm) and visible (λ = 470 nm) light increased the activity and the yield in p-xylene conversion by a factor of around 2-3, as well as making these quantities more stable in comparison with those of TiO2-P25 Degussa.

Feasibility of a novel one-stop ISET device to capture CTCs and its clinical application

PubMed Central

Zheng, Liang; Zhi, Xuan; Cheng, Boran; Chen, Yuanyuan; Zhang, Chunxiao; Shi, Dongdong; Song, Haibin; Cai, Congli; Zhou, Pengfei; Xiong, Bin

2017-01-01

Introduction Circulating tumor cells (CTCs) play a crucial role in cancer metastasis. In this study, we introduced a novel isolation method by size of epithelial tumor cells (ISET) device with automatic isolation and staining procedure, named one-stop ISET (osISET) and validated its feasibility to capture CTCs from cancer patients. Moreover, we aim to investigate the correlation between clinicopathologic features and CTCs in colorectal cancer (CRC) in order to explore its clinical application. Results The capture efficiency ranged from 80.3% to 88% with tumor cells spiked into medium while 67% to 78.3% with tumor cells spiked into healthy donors’ blood. In detection blood samples of 72 CRC patients, CTCs and clusters of circulating tumor cells (CTC-clusters) were detected with a positive rate of 52.8% (38/72) and 18.1% (13/72) respectively. Moreover, CTC positive rate was associated with factors of lymphatic or venous invasion, tumor depth, lymph node metastasis and TNM stage in CRC patients (p < 0.01). Lymphocyte count and neutrophil to lymphocyte ratio (NLR) were significantly different between CTC positive and negative groups (p < 0.01). Materials and Methods The capture efficiency of the device was tested by spiking cancer cells (MCF-7, A549, SW480, Hela) into medium or blood samples of healthy donors. Blood samples of 72 CRC patients were detected by osISET device. The clinicopathologic characteristics of 72 CRC patients were collected and the association with CTC positive rate or CTC count were analyzed. Conclusions Our osISET device was feasible to capture and identify CTCs and CTC-clusters from cancer patients. In addition, our device holds a potential for application in cancer management. PMID:27935872

Brief Report: A mass spectrometry assay to simultaneously analyze ROS1 and RET fusion gene expression in non-small cell lung cancer

PubMed Central

Wijesinghe, Priyanga; Bepler, Gerold

2014-01-01

Introduction ROS1 and RET gene fusions were recently discovered in non-small cell lung cancer (NSCLC) as potential therapeutic targets with small molecule kinase inhibitors. The conventional screening methods of these fusions are time consuming and require samples of high quality and quantity. Here, we describe a novel and efficient method by coupling the power of multiplexing PCR and the sensitivity of mass spectrometry. Methods The multiplex mass spectrometry platform simultaneously tests samples for the expression of nine ROS1 and six RET fusion genes. The assay incorporates detection of wild-type exon junctions immediately upstream and downstream of the fusion junction to exclude false negative results. To flag false positives, the system also comprises two independent assays for each fusion gene junction. Results The characteristic mass spectrometric peaks of the gene fusions were obtained using engineered plasmid constructs. Specific assays targeting the wild-type gene exon junctions were validated using cDNA from lung tissue of healthy individuals. The system was further validated using cDNA derived from NSCLC cell lines that express endogenous fusion genes. The expressed ROS1-SLC34A2 and CCDC6-RET gene fusions from the NSCLC cell lines HCC78 and LC-2/ad, respectively, were accurately detected by the novel assay. The assay is extremely sensitive, capable of detecting an event in test specimens containing 0.5% positive tumors. Conclusion The novel multiplexed assay is robustly capable of detecting 15 different clinically relevant RET and ROS1 fusion variants. The benefits of this detection method include exceptionally low sample input, high cost efficiency, flexibility, and rapid turnover. PMID:25384172

A longitudinal evaluation of performance of automated BCR-ABL1 quantitation using cartridge-based detection system.

PubMed

Enjeti, Anoop; Granter, Neil; Ashraf, Asma; Fletcher, Linda; Branford, Susan; Rowlings, Philip; Dooley, Susan

2015-10-01

An automated cartridge-based detection system (GeneXpert; Cepheid) is being widely adopted in low throughput laboratories for monitoring BCR-ABL1 transcript in chronic myelogenous leukaemia. This Australian study evaluated the longitudinal performance specific characteristics of the automated system.The automated cartridge-based system was compared prospectively with the manual qRT-PCR-based reference method at SA Pathology, Adelaide, over a period of 2.5 years. A conversion factor determination was followed by four re-validations. Peripheral blood samples (n = 129) with international scale (IS) values within detectable range were selected for assessment. The mean bias, proportion of results within specified fold difference (2-, 3- and 5-fold), the concordance rate of major molecular remission (MMR) and concordance across a range of IS values on paired samples were evaluated.The initial conversion factor for the automated system was determined as 0.43. Except for the second re-validation, where a negative bias of 1.9-fold was detected, all other biases fell within desirable limits. A cartridge-specific conversion factor and efficiency value was introduced and the conversion factor was confirmed to be stable in subsequent re-validation cycles. Concordance with the reference method/laboratory at >0.1-≤10 IS was 78.2% and at ≤0.001 was 80%, compared to 86.8% in the >0.01-≤0.1 IS range. The overall and MMR concordance were 85.7% and 94% respectively, for samples that fell within ± 5-fold of the reference laboratory value over the entire period of study.Conversion factor and performance specific characteristics for the automated system were longitudinally stable in the clinically relevant range, following introduction by the manufacturer of lot specific efficiency values.

Effects of sodium and potassium on the photovoltaic performance of CIGS solar cells

DOE PAGES

Raguse, John M.; Muzzillo, Christopher P.; Sites, James R.; ...

2016-11-17

Here, the deliberate introduction of K and Na into Cu(In, Ga)Se 2 (CIGS) absorbers was investigated by varying a combination of an SiO 2 diffusion barrier, coevaporation of KF with the CIGS absorber, and a KF postdeposition treatment (PDT). Devices made with no diffusion barrier and KF coevaporation treatment exhibited the highest photovoltaic conversion efficiency with the smallest overall distribution in key current density-voltage (J-V) performance metrics. Out-diffusion of Na and K from the substrate, KF coevaporation, and KF PDT all increased carrier concentration, open-circuit voltage, fill factor, and power conversion efficiency. Quantum-efficiency analysis of devices highlighted the greatest lossmore » in the short-circuit current density due to incomplete absorption and collection. Secondary ion mass spectrometry illustrated the efficacy of the SiO 2 film as a sodium and potassium diffusion barrier, as well as their relative concentration in the absorber. Introduction of KF appeared to enhance diffusion of Na from the substrate, in agreement with previous studies.« less

Introduction to Indoor Air Quality

MedlinePlus

... as conditions caused by outdoor impacts (such as climate change). Many reports and studies indicate that the following ... Air Duct Cleaning Asthma Health, Energy Efficiency and Climate Change Flood Cleanup IAQ at Home Indoor airPLUS Mold ...

Chapter 1 Introduction

EPA Science Inventory

Nanoparticles have attracted a great deal of attention is past years due to their enormous potential across a broad range of research disciplines. Harnessing nanoscale activity and selectivity can potentially provide extremely efficient systems for energy storage applications, en...

Introduction of the trapezoidal thermodynamic technique method for measuring and mapping the efficiency of waste-to-energy plants: A potential replacement to the R1 formula.

PubMed

Vakalis, Stergios; Moustakas, Konstantinos; Loizidou, Maria

2018-06-01

Waste-to-energy plants have the peculiarity of being considered both as energy production and as waste destruction facilities and this distinction is important for legislative reasons. The efficiency of waste-to-energy plants must be objective and consistent, independently if the focus is the production of energy, the destruction of waste or the recovery/upgrade of materials. With the introduction of polygeneration technologies, like gasification, the production of energy and the recovery/upgrade of materials, are interconnected. The existing methodology for assessing the efficiency of waste-to-energy plants is the R1 formula, which does not take into consideration the full spectrum of the operations that take place in waste-to-energy plants. This study introduces a novel methodology for assessing the efficiency of waste-to-energy plants and is defined as the 3T method, which stands for 'trapezoidal thermodynamic technique'. The 3T method is an integrated approach for assessing the efficiency of waste-to-energy plants, which takes into consideration not only the production of energy but also the quality of the products. The value that is returned from the 3T method can be placed in a tertiary diagram and the global efficiency map of waste-to-energy plants can be produced. The application of the 3T method showed that the waste-to-energy plants with high combined heat and power efficiency and high recovery of materials are favoured and these outcomes are in accordance with the cascade principle and with the high cogeneration standards that are set by the EU Energy Efficiency Directive.

Epidemic risk from cholera introductions into Mexico.

PubMed

Moore, Sean M; Shannon, Kerry L; Zelaya, Carla E; Azman, Andrew S; Lessler, Justin

2014-02-21

Stemming from the 2010 cholera outbreak in Haiti, cholera transmission in Hispaniola continues with over 40,000 cases in 2013. The presence of an ongoing cholera outbreak in the region poses substantial risks to countries throughout the Americas, particularly in areas with poor infrastructure. Since September 9, 2013 nearly 200 cholera cases have been reported in Mexico, as a result of introductions from Hispaniola or Cuba. There appear to have been multiple introductions into Mexico resulting in outbreaks of 2 to over 150 people. Using publicly available data, we attempt to estimate the reproductive number (R) of cholera in Mexico, and thereby assess the potential of continued introductions to establish a sustained epidemic. We estimate R for cholera in Mexico to be between 0.8 to 1.1, depending on the number of introductions, with the confidence intervals for the most plausible estimates crossing 1. These results suggest that the efficiency of cholera transmission in some regions of Mexico is near that necessary for a large epidemic. Intensive surveillance, evaluation of water and sanitation infrastructure, and planning for rapid response are warranted steps to avoid potential large epidemics in the region.

Progress in Emission Efficiency of Organic Light-Emitting Diodes: Basic Understanding and Its Technical Application

NASA Astrophysics Data System (ADS)

Tsutsui, Tetsuo; Takada, Noriyuki

2013-11-01

The technical history of when and how the basic understanding of the emission efficiency of organic light-emitting diodes (OLEDs) was established over the last 50 years is described. At first, our understanding of emission efficiency in single-crystal and thin-film electroluminescence (EL) devices in the early stages before the Eastman-Kodak breakthrough, that is, the introduction of the concept of multilayer structures, is examined. Then our contemplation travels from the Eastman-Kodak breakthrough towards the presently widely accepted concept of emission efficiency. The essential issues concerning the emission efficiency of OLEDs are summarized to help readers to obtain a common understanding of OLED efficiency problems, and detailed discussions on the primary factors that determine emission efficiency are given. Finally, some comments on remaining issues are presented.

Ionic liquid foam floatation coupled with ionic liquid dispersive liquid-liquid microextraction for the separation and determination of estrogens in water samples by high-performance liquid chromatography with fluorescence detection.

PubMed

Zhang, Rui; Wang, Chuanliu; Yue, Qiaohong; Zhou, Tiecheng; Li, Na; Zhang, Hanqi; Hao, Xiaoke

2014-11-01

An ionic liquid foam floatation coupled with ionic liquid dispersive liquid-liquid microextraction method was proposed for the extraction and concentration of 17-α-estradiol, 17-β-estradiol-benzoate, and quinestrol in environmental water samples by high-performance liquid chromatography with fluorescence detection. 1-Hexyl-3-methylimidazolium tetrafluoroborate was applied as foaming agent in the foam flotation process and dispersive solvent in microextraction. The introduction of the ion-pairing and salting-out agent NH4 PF6 was beneficial to the improvement of recoveries for the hydrophobic ionic liquid phase and analytes. Parameters of the proposed method including concentration of 1-hexyl-3-methylimidazolium tetrafluoroborate, flow rate of carrier gas, floatation time, types and concentration of ionic liquids, salt concentration in samples, extraction time, and centrifugation time were evaluated. The recoveries were between 98 and 105% with relative standard deviations lower than 7% for lake water and well water samples. The isolation of the target compounds from the water was found to be efficient, and the enrichment factors ranged from 4445 to 4632. This developing method is free of volatile organic solvents compared with regular extraction. Based on the unique properties of ionic liquids, the application of foam floatation, and dispersive liquid-liquid microextraction was widened. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Rough spacecraft surfaces -a threat to Planetary Protection issues

NASA Astrophysics Data System (ADS)

Probst, Alexander; Facius, Rainer; Wirth, Reinhard; Moissl-Eichinger, Christine

Inadvertent introduction of terrestrial microorganisms to foreign solar bodies could compromise the integrity of present and future life detection missions. For Planetary Protection purposes space agencies measure the aerobic, mesophilic spore load of a spacecraft as a proxy indicator in order to determine its bioload. Emerging novel hardware in space science implicates novel surface structures and materials that need to be controlled with regard to contaminations. For instance (roughened) carbon fiber reinforced plastic and Vectran fabric for construction of landing platforms and airbags, respectively, have been used in some Mars exploration missions. These materials have different levels of roughness and their potential risk to retain spores for insufficient sampling success has never been in scope of investigation. In this comprehensive study we evaluated ESA's novel nylon flocked swab protocol on stainless steel and other tech-nical surfaces with regard to Bacillus spore recovery. Low recovery efficiencies of the ESA standard wipe assay for large surface sampling were demonstrated with regard to Bacillus at-rophaeus spore detection. Therefore another protocol designed for rough surface sampling was evaluated on Vectran fabric and (roughened) carbon fiber reinforced plastic. Moreover, scan-ning electron micrographs of the technical surfaces studied allowed a more detailed view on their properties. The evaluated sampling protocols and the corresponding results are of high interest for future life detection missions in order to preserve their scientific integrity throughout spacecraft assembly.

Polypyrrole nanowire as an excellent solid phase microextraction fiber for bisphenol A analysis in food samples followed by ion mobility spectrometry.

PubMed

Kamalabadi, Mahdie; Mohammadi, Abdorreza; Alizadeh, Naader

2016-08-15

A polypyrrole nanowire coated fiber was prepared and used in head-space solid phase microextraction coupled with ion mobility spectrometry (HS-SPME-IMS) to the analysis of bisphenol A (BPA) in canned food samples, for the first time. This fiber was synthesized by electrochemical oxidation of the monomer in aqueous solution. The fiber characterization by scanning electron microscopy (SEM) revealed that the new fiber exhibited two-dimensional structures with a nanowire morphology. The effects of important extraction parameters on the efficiency of HS-SPME were investigated and optimized. Under the optimum conditions, the linearity of 10-150ngg(-1) and limit of detection (based on S/N=3) of 1ngg(-1) were obtained in BPA analysis. The repeatability (n=5) expressed as the relative standard deviation (RSD%) was 5.8%. At the end, the proposed method was successfully applied to determine BPA in various canned food samples (peas, corns, beans). Relative recoveries were obtained 93-96%. Method validation was conducted by comparing our results with those obtained through HPLC with fluorescence detection (FLD). Compatible results indicate that the proposed method can be successfully used in BPA analysis. This method is simple and cheaper than chromatographic methods, with no need of extra organic solvent consumption and derivatization prior to sample introduction. Copyright © 2016 Elsevier B.V. All rights reserved.

Identification of nonvolatile coal derived products via chromatography coupled with on-line FTIR detection. Quarterly progress report, March 1-May 31, 1985. [C/sub 2/H/sub 2/ extracts of ground coal, coffee and paprika

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

Taylor, L.T.

Because it has been our goal to interface the supercritical fluid chromatograph with a Fourier transform infrared spectrometer we have initially chosen packed columns due to their increased sample capacities, and supercritical CO/sub 2/ because of its infrared transparency. This paper compares two sampling techniques that can be utilized in packed column supercritical fluid Chromatography (SFC). Traditional sample introduction is accomplished using an injector with a sample loop. The loop is filled with the appropriate amount of material, and subsequently inserted into the mobile phase path. In most cases the sample must be either dissolved or extracted into an appropriatemore » solvent for such sample introduction. Note that unlike HPLC, where the solvent can be the same as the mobile phase, traditional sampling with SFC must use a solvent that is very different from the mobile phase. As a result, solvent peaks are almost always present, especially with universal detectors like FTIR. An alternative method is described here whereby both extraction of the sample and introduction of the extract onto the column is accomplished on-line using only the supercritical fluid mobile phase. This sampling technique is made possible by a simple valving scheme which ties directly the extraction vessel, the injector, the packed column and the detector. This technique has several advantages over the traditional methods, not the least of which is the absence of a large amount of foreign solvent introduced on the column. 11 refs., 7 figs.« less

Photocatalytic degradation of ofloxacin and evaluation of the residual antimicrobial activity.

PubMed

Peres, M S; Maniero, M G; Guimarães, J R

2015-03-01

Ofloxacin is an antimicrobial agent frequently found in significant concentrations in wastewater and surface water. Its continuous introduction into the environment is a potential risk to non-target organisms or to human health. In this study, ofloxacin degradation by UV/TiO2 and UV/TiO2/H2O2, antimicrobial activity (E. coli) of samples subjected to these processes, and by-products formed were evaluated. For UV/TiO2, the degradation efficiency was 89.3% in 60 min of reaction when 128 mg L(-1) TiO2 were used. The addition of 1.68 mmol L(-1) hydrogen peroxide increased degradation to 97.8%. For UV/TiO2, increasing the catalyst concentration from 4 to 128 mg L(-1) led to an increase in degradation efficiency. For both processes, the antimicrobial activity was considerably reduced throughout the reaction time. The structures of two by-products are presented: m/z 291 (9-fluoro-3-methyl-10-(methyleneamino)-7-oxo-2,3-dihydro-7H-[1,4]oxazino[2,3,4-ij]quinoline-6-carboxylic acid) and m/z 157 ((Z)-2-formyl-3-((2-oxoethyl)imino)propanoic acid).

Efficiency at Maximum Power Output of a Quantum-Mechanical Brayton Cycle

NASA Astrophysics Data System (ADS)

Yuan, Yuan; He, Ji-Zhou; Gao, Yong; Wang, Jian-Hui

2014-03-01

The performance in finite time of a quantum-mechanical Brayton engine cycle is discussed, without introduction of temperature. The engine model consists of two quantum isoenergetic and two quantum isobaric processes, and works with a single particle in a harmonic trap. Directly employing the finite-time thermodynamics, the efficiency at maximum power output is determined. Extending the harmonic trap to a power-law trap, we find that the efficiency at maximum power is independent of any parameter involved in the model, but depends on the confinement of the trapping potential.

Timing of Introduction of Complementary Foods to US Infants, National Health and Nutrition Examination Survey 2009-2014.

PubMed

Barrera, Chloe M; Hamner, Heather C; Perrine, Cria G; Scanlon, Kelley S

2018-03-01

Although there has been inconsistency in recommendations regarding the optimal time for introducing complementary foods, most experts agree that introduction should not occur before 4 months. Despite recommendations, studies suggest that 20% to 40% of US infants are introduced to foods at younger than 4 months. Previous studies focused on the introduction of solid foods and are not nationally representative. Our aims were to provide a nationally representative estimate of the timing of introduction of complementary foods and to describe predictors of early (<4 months) introduction. We conducted a cross-sectional analysis of 2009-2014 National Health and Nutrition Examination Survey data. The study included 1,482 children aged 6 to 36 months. Timing of first introduction to complementary foods (anything other than breast milk or formula) was analyzed. Prevalence estimates of first introduction to complementary foods are presented by month. Logistic regression was used to assess characteristics associated with early (<4 months) introduction. In this sample, 16.3% of US infants were introduced to complementary foods at <4 months, 38.3% between 4 and <6 months, 32.5% between 6 and <7 months, and 12.9% at ≥7 months of age. In unadjusted analyses, early introduction varied by breastfeeding status; race/Hispanic origin; Special Supplemental Nutrition Program for Women, Infants, and Children participation; and maternal age. In adjusted analyses, only breastfeeding status remained significant; infants who never breastfed or stopped at <4 months were more likely (odds ratio 2.27; 95% CI 1.62 to 3.18) to be introduced to complementary foods early than infants who breastfed ≥4 months. Despite using a broader definition of complementary foods, this analysis found a lower prevalence of early introduction in this nationally representative sample than previous studies that included only solids. However, many young children were still introduced to complementary foods earlier than recommended. Strategies to support caregivers to adhere to infant feeding guidelines may be needed. Copyright © 2018 Academy of Nutrition and Dietetics. Published by Elsevier Inc. All rights reserved.

Deployable Fuel Cell Power Generator - Multi-Fuel Processor

DTIC Science & Technology

2009-02-01

and the system operating pressure, while the separation efficiency depends on the evaporator design. Desulfurizer – A flow-through gas -solid or gas ...meeting the Executive Order (EO) 13423 and the Energy Policy Act of 2005 to improve energy efficiency and reduce greenhouse gas emissions 3 percent...use available fuel such as natural gas (methane) or propane. The ability to reform multitude of fuels can accelerate the introduction of more

Chemical vapor generation sample introduction for the determination of As, Cd, Sb, Hg, and Pb in nail polish by inductively coupled plasma mass spectrometry

NASA Astrophysics Data System (ADS)

Huang, Fan-Feng; Jiang, Shiuh-Jen; Chen, Yen-Ling; Sahayam, A. C.

2018-02-01

This paper describes a flow injection vapor generation (VG) method using inductively coupled plasma mass spectrometry (ICP-MS) for determining As, Cd, Sb, Hg, and Pb in nail polish. The samples for VG were prepared as aqueous slurries of a nail polish (0.5% m/v), thiourea (1% m/v), Co(II) (0.75 μg mL- 1), and HCl (1.2% v/v). Chemical VG of As, Cd, Sb, Hg, and Pb ions, by reduction with tetrahydroborate (3% m/v in 0.2% m/v NaOH), enabled their separation from the slurry. With VG sample introduction, As, Cd, Sb and Hg signals were increased by 1-2 orders (except Pb) compared to solution nebulization due to better sample introduction. Quantifications were performed by VG ICP-MS using isotope dilution and standard addition methods as slopes of calibration plots of analytes in the slurries were higher. Using the reported procedure, samples of three nail polishes purchased locally were analyzed for their levels of As, Cd, Sb, Hg, and Pb. The results obtained were in good agreement with those measured using electrothermal vaporization ICP-MS. In the original nail polish sample, the detection limits, calculated as 3σ of blank measurements, for As, Cd, Sb, Hg, and Pb, estimated from standard addition curves, were 0.06, 0.12, 0.14, 0.2, and 12 ng g- 1, respectively.

Energy and Environment Guide to Action - Chapter 1: Introduction and Background

EPA Pesticide Factsheets

Introduces the Energy and Environment Guide to Action which documents best practices for designing and implementing state policies and the benefits of energy efficiency, renewable energy, and combined heat and power policies and programs.

The Technology Introduction of Chain Boiler Energy Conservation Transformation

NASA Astrophysics Data System (ADS)

Li, Henan; Liu, Xiwen; Yuan, Hong; Lin, Jiadai; Zhang, Yu

2017-12-01

Introduced the present status of chain boiler efficiency is low, the system analysis of the chain boiler optimization and upgrading of technology, for the whole progress of chain boiler to provide some ideas and reference.

On estimation in k-tree sampling

Treesearch

Christoph Kleinn; Frantisek Vilcko

2007-01-01

The plot design known as k-tree sampling involves taking the k nearest trees from a selected sample point as sample trees. While this plot design is very practical and easily applied in the field for moderate values of k, unbiased estimation remains a problem. In this article, we give a brief introduction to the...

Rating aircraft on energy

NASA Technical Reports Server (NTRS)

Maddalon, D. V.

1974-01-01

Questions concerning the energy efficiency of aircraft compared to ground transport are considered, taking into account as energy intensity the energy consumed per passenger statute mile. It is found that today's transport aircraft have an energy intensity potential comparable to that of ground modes. Possibilities for improving the energy density are also much better in the case of aircraft than in the case of ground transportation. Approaches for potential reductions in aircraft energy consumption are examined, giving attention to steps for increasing the efficiency of present aircraft and to reductions in energy intensity obtainable by the introduction of new aircraft utilizing an advanced technology. The use of supercritical aerodynamics is discussed along with the employment of composite structures, advances in propulsion systems, and the introduction of very large aircraft. Other improvements in fuel economy can be obtained by a reduction of skin-friction drag and a use of hydrogen fuel.

Improving the environmental and performance characteristics of vehicles by introducing the surfactant additive into gasoline.

PubMed

Magaril, Elena; Magaril, Romen

2016-09-01

The operation of modern vehicles requires the introduction of package of fuel additives to ensure the required level of operating characteristics, some of which cannot be achieved by current oil refining methods. The use of additives allows flexibility of impact on the properties of the fuel at minimal cost, increasing the efficiency and environmental safety of vehicles. Among the wide assortment of additives available on the world market, many are surfactants. It has been shown that the introduction of some surfactants into gasoline concurrently reduces losses from gasoline evaporation, improves the mixture formation during injection of gasoline into the engine and improves detergent and anticorrosive properties. The surfactant gasoline additive that provides significant improvement in the quality of gasoline used and environmental and operating characteristics of vehicles has been developed and thoroughly investigated. The results of studies confirming the efficiency of the gasoline additive application are herein presented.

Age at Introduction to Solid Foods and Child Obesity at 6 Years.

PubMed

Barrera, Chloe M; Perrine, Cria G; Li, Ruowei; Scanlon, Kelley S

2016-06-01

Epidemiological evidence suggests that timing of introduction of solid foods may be associated with subsequent obesity, and the association may vary by whether an infant is breastfed or formula-fed. We included 1181 infants who participated in the Infant Feeding Practices Study II (IFPS II) and the Year 6 Follow Up (Y6FU) study. Data from IFPS II were used to calculate the primary exposure and timing of solid food introduction (<4, 4-<6, and ≥6 months), and data from Y6FU were used to calculate the primary outcome and obesity at 6 years of age (BMI ≥95th percentile). We used multivariable logistic regression to assess the association between timing of the introduction of solids and obesity at 6 years and test whether this association was modified by breastfeeding duration (breastfed for 4 months vs. not). Prevalence of obesity in our sample was 12.0%. The odds of obesity was higher among infants introduced to solids <4 months compared to those introduced at 4-<6 months (odds ratio [OR] = 1.66; 95% CI, 1.15, 2.40) in unadjusted analysis; however, this relationship was no longer significant after adjustment for covariates (OR = 1.18; 95% CI, 0.79, 1.77). Introduction of solids ≥6 months was not associated with obesity. We found no interaction between breastfeeding duration and early solid food introduction and subsequent obesity. Timing of introduction of solid foods was not associated with child obesity at 6 years in this sample. Given the inconsistency in findings with other studies, further studies in larger populations may be needed.

Inductively Coupled Plasma Optical Emission Spectrometry for Rare Earth Elements Analysis

NASA Astrophysics Data System (ADS)

He, Man; Hu, Bin; Chen, Beibei; Jiang, Zucheng

2017-01-01

Inductively coupled plasma optical emission spectrometry (ICP-OES) merits multielements capability, high sensitivity, good reproducibility, low matrix effect and wide dynamic linear range for rare earth elements (REEs) analysis. But the spectral interference in trace REEs analysis by ICP-OES is a serious problem due to the complicated emission spectra of REEs, which demands some correction technology including interference factor method, derivative spectrum, Kalman filtering algorithm and partial least-squares (PLS) method. Matrix-matching calibration, internal standard, correction factor and sample dilution are usually employed to overcome or decrease the matrix effect. Coupled with various sample introduction techniques, the analytical performance of ICP-OES for REEs analysis would be improved. Compared with conventional pneumatic nebulization (PN), acid effect and matrix effect are decreased to some extent in flow injection ICP-OES, with higher tolerable matrix concentration and better reproducibility. By using electrothermal vaporization as sample introduction system, direct analysis of solid samples by ICP-OES is achieved and the vaporization behavior of refractory REEs with high boiling point, which can easily form involatile carbides in the graphite tube, could be improved by using chemical modifier, such as polytetrafluoroethylene and 1-phenyl-3-methyl-4-benzoyl-5-pyrazone. Laser ablation-ICP-OES is suitable for the analysis of both conductive and nonconductive solid samples, with the absolute detection limit of ng-pg level and extremely low sample consumption (0.2 % of that in conventional PN introduction). ICP-OES has been extensively employed for trace REEs analysis in high-purity materials, and environmental and biological samples.

Real-time RT-PCR assays to differentiate wild-type group A rotavirus strains from Rotarix(®) and RotaTeq(®) vaccine strains in stool samples.

PubMed

Gautam, Rashi; Esona, Mathew D; Mijatovic-Rustempasic, Slavica; Ian Tam, Ka; Gentsch, Jon R; Bowen, Michael D

2014-01-01

Group A rotaviruses (RVA) are the leading cause of severe diarrhea in young children worldwide. Two live-attenuated RVA vaccines, Rotarix(®) and RotaTeq(®) are recommended by World Health Organization (WHO) for routine immunization of all infants. Rotarix(®) and RotaTeq(®) vaccines have substantially reduced RVA associated mortality but occasionally have been associated with acute gastroenteritis (AGE) cases identified in vaccinees and their contacts. High-throughput assays are needed to monitor the prevalence of vaccine strains in AGE cases and emergence of new vaccine-derived strains following RVA vaccine introduction. In this study, we have developed quantitative real-time RT-PCR (qRT-PCR) assays for detection of Rotarix(®) and RotaTeq(®) vaccine components in stool samples. Real-time RT-PCR assays were designed for vaccine specific targets in the genomes of Rotarix(®) (NSP2, VP4) and RotaTeq(®) (VP6, VP3-WC3, VP3-human) and validated on sequence confirmed stool samples containing vaccine strains, wild-type RVA strains, and RVA-negative stools. For quantification, standard curves were generated using dsRNA transcripts derived from RVA gene segments. Rotarix(®) NSP2 and VP4 qRT-PCR assays exhibited 92-100% sensitivity, 99-100% specificity, 94-105% efficiency, and a limit of detection of 2-3 copies per reaction. RotaTeq(®) VP6, VP3-WC3, and VP3-human qRT-PCR assays displayed 100% sensitivity, 94-100% specificity, 91-102% efficiency and limits of detection of 1 copy, 2 copies, and 140 copies, respectively. These assays permit rapid identification of Rotarix(®) and RotaTeq(®) vaccine components in stool samples from clinical and surveillance studies and will be helpful in determining the frequency of vaccine strain-associated AGE.

Real-time RT-PCR assays to differentiate wild-type group A rotavirus strains from Rotarix® and RotaTeq® vaccine strains in stool samples

PubMed Central

Gautam, Rashi; Esona, Mathew D; Mijatovic-Rustempasic, Slavica; Ian Tam, Ka; Gentsch, Jon R; Bowen, Michael D

2014-01-01

Group A rotaviruses (RVA) are the leading cause of severe diarrhea in young children worldwide. Two live-attenuated RVA vaccines, Rotarix® and RotaTeq® are recommended by World Health Organization (WHO) for routine immunization of all infants. Rotarix® and RotaTeq® vaccines have substantially reduced RVA associated mortality but occasionally have been associated with acute gastroenteritis (AGE) cases identified in vaccinees and their contacts. High-throughput assays are needed to monitor the prevalence of vaccine strains in AGE cases and emergence of new vaccine-derived strains following RVA vaccine introduction. In this study, we have developed quantitative real-time RT-PCR (qRT-PCR) assays for detection of Rotarix® and RotaTeq® vaccine components in stool samples. Real-time RT-PCR assays were designed for vaccine specific targets in the genomes of Rotarix® (NSP2, VP4) and RotaTeq® (VP6, VP3-WC3, VP3-human) and validated on sequence confirmed stool samples containing vaccine strains, wild-type RVA strains, and RVA-negative stools. For quantification, standard curves were generated using dsRNA transcripts derived from RVA gene segments. Rotarix® NSP2 and VP4 qRT-PCR assays exhibited 92–100% sensitivity, 99–100% specificity, 94–105% efficiency, and a limit of detection of 2–3 copies per reaction. RotaTeq® VP6, VP3-WC3, and VP3-human qRT-PCR assays displayed 100% sensitivity, 94–100% specificity, 91–102% efficiency and limits of detection of 1 copy, 2 copies, and 140 copies, respectively. These assays permit rapid identification of Rotarix® and RotaTeq® vaccine components in stool samples from clinical and surveillance studies and will be helpful in determining the frequency of vaccine strain-associated AGE. PMID:24342877

A practical guide to value of information analysis.

PubMed

Wilson, Edward C F

2015-02-01

Value of information analysis is a quantitative method to estimate the return on investment in proposed research projects. It can be used in a number of ways. Funders of research may find it useful to rank projects in terms of the expected return on investment from a variety of competing projects. Alternatively, trialists can use the principles to identify the efficient sample size of a proposed study as an alternative to traditional power calculations, and finally, a value of information analysis can be conducted alongside an economic evaluation as a quantitative adjunct to the 'future research' or 'next steps' section of a study write up. The purpose of this paper is to present a brief introduction to the methods, a step-by-step guide to calculation and a discussion of issues that arise in their application to healthcare decision making. Worked examples are provided in the accompanying online appendices as Microsoft Excel spreadsheets.

Environmental applications of single collector high resolution ICP-MS.

PubMed

Krachler, Michael

2007-08-01

The number of environmental applications of single collector high resolution ICP-MS (HR-ICP-MS) has increased rapidly in recent years. There are many factors that contribute to make HR-ICP-MS a very powerful tool in environmental analysis. They include the extremely low detection limits achievable, tremendously high sensitivity, the ability to separate ICP-MS signals of the analyte from spectral interferences, enabling the reliable determination of many trace elements, and the reasonable precision of isotope ratio measurements. These assets are improved even further using high efficiency sample introduction systems. Therefore, external factors such as the stability of laboratory blanks are frequently the limiting factor in HR-ICP-MS analysis rather than the detection power. This review aims to highlight the most recent applications of HR-ICP-MS in this sector, focusing on matrices and applications where the superior capabilities of the instrumental technique are most useful and often ultimately required.

Study of the oxidized and non- oxidized bitumen modified with additive «Adgezolin» by using electron paramagnetic resonance

NASA Astrophysics Data System (ADS)

Mukhamatdinov, I.; Gafurov, M.; Kemalov, A.; Rodionov, A.; Mamin, G.; Fakhretdinov, P.

2018-05-01

Cationic surfactant (adhesion additive) «Adgezolin» has been developed. It is shown that introduction of «Adgezolin» into the oxidized bitumen increases the relative amount of asphaltenes and monocyclearomatic hydrocarbons. By means of electron paramagnetic resonance (EPR) it is demonstrated that the introduction of additive «Adgezolin» increases the number of paramagnetic «free» carbon radicals (FR) in the oxidized bitumen and decreases that in the unoxidized species. In both types of bitumen shift from the Lorentzian to Gaussian EPR lineshape of FR is obtained that could be connected with as an increase of the samples homogeneity. It is supposed that while in the oxygenated bitumens introduction of additives leads to the disaggregation of asphaltene-resins compounds, in the unoxidized samples the balance is shifted towards formation of di-radicals.

Friction coefficient of spruce pine on steel -- a note on lubricants

Treesearch

Charles W. McMillin; Truett J. Lemoine; Floyd G. Manwiller

1970-01-01

Generally, the introduction of water and ethanol increased the friction coefficient for ovendry samples but decreased the coeffecient when the samples were saturated. Octanoic acid decreased the coefficient when samples were wet. In the entire experiment, coefficients ranged from 0.14 to 0.78.

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

Veselov, D. A., E-mail: dmitriy90@list.ru; Shashkin, I. S.; Bakhvalov, K. V.

Semiconductor lasers based on MOCVD-grown AlGaInAs/InP separate-confinement heterostructures are studied. It is shown that raising only the energy-gap width of AlGaInAs-waveguides without the introduction of additional barriers results in more pronounced current leakage into the cladding layers. It is found that the introduction of additional barrier layers at the waveguide–cladding-layer interface blocks current leakage into the cladding layers, but results in an increase in the internal optical loss with increasing pump current. It is experimentally demonstrated that the introduction of blocking layers makes it possible to obtain maximum values of the internal quantum efficiency of stimulated emission (92%) and continuouswavemore » output optical power (3.2 W) in semiconductor lasers in the eye-safe wavelength range (1400–1600 nm).« less

Design and performance of a new continuous-flow sample-introduction system for flame infrared-emission spectrometry: Applications in process analysis, flow injection analysis, and ion-exchange high-performance liquid chromatography.

PubMed

Lam, C K; Zhang, Y; Busch, M A; Busch, K W

1993-06-01

A new sample introduction system for the analysis of continuously flowing liquid streams by flame infrared-emission (FIRE) spectrometry has been developed. The system uses a specially designed purge cell to strip dissolved CO(2) from solution into a hydrogen gas stream that serves as the fuel for a hydrogen/air flame. Vibrationally excited CO(2) molecules present in the flame are monitored with a simple infrared filter (4.4 mum) photometer. The new system can be used to introduce analytes as a continuous liquid stream (process analysis mode) or on a discrete basis by sample injection (flow injection analysis mode). The key to the success of the method is the new purge-cell design. The small internal volume of the cell minimizes problems associated with purge-cell clean-out and produces sharp, reproducible signals. Spent analytical solution is continuously drained from the cell, making cell disconnection and cleaning between samples unnecessary. Under the conditions employed in this study, samples could be analyzed at a maximum rate of approximately 60/h. The new sample introduction system was successfully tested in both a process analysis- and a flow injection analysis mode for the determination of total inorganic carbon in Waco tap water. For the first time, flame infrared-emission spectrometry was successfully extended to non-volatile organic compounds by using chemical pretreatment with peroxydisulfate in the presence of silver ion to convert the analytes into dissolved carbon dioxide, prior to purging and detection by the FIRE radiometer. A test of the peroxydisulfate/Ag(+) reaction using six organic acids and five sugars indicated that all 11 compounds were oxidized to nearly the same extent. Finally, the new sample introduction system was used in conjunction with a simple filter FIRE radiometer as a detection system in ion-exchange high-performance liquid chromatography. Ion-exchange chromatograms are shown for two aqueous mixtures, one containing six organic acids and the second containing six mono-, di-, and trisaccharides.

Single-step CE for miniaturized and easy-to-use system.

PubMed

Ono, Koichi; Kaneda, Shohei; Fujii, Teruo

2013-03-01

We developed a novel single-step capillary electrophoresis (SSCE) scheme for miniaturized and easy to use system by using a microchannel chip, which was made from the hydrophilic material polymethyl methacrylate (PMMA), equipped with a capillary stop valve. Taking the surface tension property of liquids into consideration, the capillary effect was used to introduce liquids and control capillary stop valves in a partial barrier structure in the wall of the microchannel. Through the combined action of stop valves and air vents, both sample plug formation for electrophoresis and sample injection into a separation channel were successfully performed in a single step. To optimize SSCE, different stop valve structures were evaluated using actual microchannel chips and the finite element method with the level set method. A partial barrier structure at the bottom of the channel functioned efficiently as a stop valve. The stability of stop valve was confirmed by a shock test, which was performed by dropping the microchannel chip to a floor. Sample plug deformation could be reduced by minimizing the size of the side partial barrier. By dissolving hydroxyl ethyl cellulose and using it as the sample solution, the EOF and adsorption of the sample into the PMMA microchannel were successfully reduced. Using this method, a 100-bp DNA ladder was concentrated; good separation was observed within 1 min. At a separation length of 5 mm, the signal was approximately 20-fold higher than a signal of original sample solution by field-amplified sample stacking effect. All operations, including liquid introduction and sample separation, can be completed within 2 min by using the SSCE scheme. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A testing-coverage software reliability model considering fault removal efficiency and error generation

PubMed Central

Li, Qiuying; Pham, Hoang

2017-01-01

In this paper, we propose a software reliability model that considers not only error generation but also fault removal efficiency combined with testing coverage information based on a nonhomogeneous Poisson process (NHPP). During the past four decades, many software reliability growth models (SRGMs) based on NHPP have been proposed to estimate the software reliability measures, most of which have the same following agreements: 1) it is a common phenomenon that during the testing phase, the fault detection rate always changes; 2) as a result of imperfect debugging, fault removal has been related to a fault re-introduction rate. But there are few SRGMs in the literature that differentiate between fault detection and fault removal, i.e. they seldom consider the imperfect fault removal efficiency. But in practical software developing process, fault removal efficiency cannot always be perfect, i.e. the failures detected might not be removed completely and the original faults might still exist and new faults might be introduced meanwhile, which is referred to as imperfect debugging phenomenon. In this study, a model aiming to incorporate fault introduction rate, fault removal efficiency and testing coverage into software reliability evaluation is developed, using testing coverage to express the fault detection rate and using fault removal efficiency to consider the fault repair. We compare the performance of the proposed model with several existing NHPP SRGMs using three sets of real failure data based on five criteria. The results exhibit that the model can give a better fitting and predictive performance. PMID:28750091

Introduction of new process technology into the wastewater treatment sector.

PubMed

Parker, Denny S

2011-06-01

Innovative wastewater treatment technologies are developed to respond to changing regulatory requirements, increase efficiency, and enhance sustainability or to reduce capital or operating costs. Drawing from experience of five successful new process introductions from both the inventor/developer's and adopter's viewpoints coupled with the application of marketing analysis tools (an S curve), the phases of new technology market penetration can be identified along with the influence of market drivers, marketing, patents and early adopters. The analysis is used to identify measures that have increased the capture of benefits from new technology introduction. These have included funding by the government for research and demonstrations, transparency of information, and the provision of independent technology evaluations. To reduce the barriers and speed the introduction of new technology, and thereby harvest the full benefits from it, our industry must develop mechanisms for sharing risks and any consequences of failure more broadly than just amongst the early adopters. WEF and WERF will continue to have the central role in providing reliable information networks and independent technology evaluations.

Design and development of a highly sensitive, field portable plasma source instrument for on-line liquid stream monitoring and real-time sample analysis

NASA Astrophysics Data System (ADS)

Duan, Yixiang; Su, Yongxuan; Jin, Zhe; Abeln, Stephen P.

2000-03-01

The development of a highly sensitive, field portable, low-powered instrument for on-site, real-time liquid waste stream monitoring is described in this article. A series of factors such as system sensitivity and portability, plasma source, sample introduction, desolvation system, power supply, and the instrument configuration, were carefully considered in the design of the portable instrument. A newly designed, miniature, modified microwave plasma source was selected as the emission source for spectroscopy measurement, and an integrated small spectrometer with a charge-coupled device detector was installed for signal processing and detection. An innovative beam collection system with optical fibers was designed and used for emission signal collection. Microwave plasma can be sustained with various gases at relatively low power, and it possesses high detection capabilities for both metal and nonmetal pollutants, making it desirable to use for on-site, real-time, liquid waste stream monitoring. An effective in situ sampling system was coupled with a high efficiency desolvation device for direct-sampling liquid samples into the plasma. A portable computer control system is used for data processing. The new, integrated instrument can be easily used for on-site, real-time monitoring in the field. The system possesses a series of advantages, including high sensitivity for metal and nonmetal elements; in situ sampling; compact structure; low cost; and ease of operation and handling. These advantages will significantly overcome the limitations of previous monitoring techniques and make great contributions to environmental restoration and monitoring.

The Effect of Introducing a Smaller and Lighter Basketball on Female Basketball Players’ Shot Accuracy

PubMed Central

Podmenik, Nadja; Leskošek, Bojan; Erčulj, Frane

2012-01-01

Our study examined whether the introduction of a smaller and lighter basketball (no. 6) affected the accuracy of female basketball players’ shots at the basket. The International Basketball Federation (FIBA) introduced a size 6 ball in the 2004/2005 season to improve the efficiency and accuracy of technical elements, primarily shots at the basket. The sample for this study included 573 European female basketball players who were members of national teams that had qualified for the senior women’s European championships in 2001, 2003, 2005 and 2007. A size 7 (larger and heavier) basketball was used by 286 players in 1,870 matches, and a size 6 basketball was used by 287 players in 1,966 matches. The players were categorised into three playing positions: guards, forwards and centres. The results revealed that statistically significant changes by year occurred only in terms of the percentage of successful free throws. With the size 6 basketball, this percentage decreased. Statistically significant differences between the playing positions were observed in terms of the percentage of field goals worth three points (between guards and forwards) and two points (between guards and centres). The results show that the introduction of the size 6 basketball did not lead to improvement in shooting accuracy (the opposite was found for free throws), although the number of three-point shots increased. PMID:23486286

Advanced component technologies for energy-efficient turbofan engines

NASA Technical Reports Server (NTRS)

Saunders, N. T.

1980-01-01

The paper reviews NASA's Energy Efficient Engine Project which was initiated to provide the advanced technology base for a new generation of fuel-conservative engines for introduction into airline service by the late 1980s. Efforts in this project are directed at advancing engine component and systems technologies to a point of demonstrating technology-readiness by 1984. Early results indicate high promise in achieving most of the goals established in the project.

[Efficiency of preventive dental care in school dentistry system].

PubMed

Avraamova, O G; Kolesnik, A G; Kulazhenko, T V; Zadapaeva, S V; Shevchenko, S S

2014-01-01

Ways of development of Russian school dentistry are defined and justified based on the analysis according to logistics, personnel, legal, financial and economic basis for the reorientation of the service for preventive direction, which should be a priority in the current conditions. The implemented model of school dental care based on team work of the dentist and dental hygienist proved to be highly efficient and may be recommended for wide introduction in practice.

Application of Two-Sided Matching to Internal Labor of the Hellenic Navy

DTIC Science & Technology

2012-03-01

were developed, leading to the introduction of various choice programs that allow parents to pick schools for their children within or outside...any nature (i.e., military) plays a crucial role towards the direction of efficiency and effectiveness. A well-designed assignment process is a handy...v ABSTRACT The assignment process in an organization of any nature (i.e., military) plays a crucial role towards the direction of efficiency and

Photocatalytic Cellulosic Electrospun Fibers for the Degradation of Potent Cyanobacteria Toxin Microcystin-LR

DTIC Science & Technology

2012-01-01

treatment applications using solar light as a renewable source of energy. Introduction The need for low cost and efficient water treatment strategies... photocatalysis with nanoparticles (such as titania, TiO2) show tremendous promise as a simple and energy efficient tech- nology for water purification and...which limits the amount of available sunlight that can be used for photocatalysis . To circumvent this issue, methods have been developed to extend

Respondent-Driven Sampling with Hard-to-Reach Emerging Adults: An Introduction and Case Study with Rural African Americans

ERIC Educational Resources Information Center

Kogan, Steven M.; Wejnert, Cyprian; Chen, Yi-fu; Brody, Gene H.; Slater, LaTrina M.

2011-01-01

Obtaining representative samples from populations of emerging adults who do not attend college is challenging for researchers. This article introduces respondent-driven sampling (RDS), a method for obtaining representative samples of hard-to-reach but socially interconnected populations. RDS combines a prescribed method for chain referral with a…

Impact of Oxidant Residuals on Ground Water Samples at ISCO Sites: Recommended Guidelines for Sample Preservation

EPA Science Inventory

In-situ chemical oxidation (ISCO) involves the introduction of a chemical oxidant into the subsurface for the purpose of transforming ground water contaminants into less toxic or harmless byproducts. Due to oxidant persistence, ground water samples collected at hazardous waste si...

Sponge and skin excision sampling for recovery of Salmonella and Campylobacter from defeathered broiler carcasses

USDA-ARS?s Scientific Manuscript database

Introduction: Salmonella and Campylobacter contamination of broiler carcass skin increases during feather removal. There are several methods for sampling carcasses including sponging or swabbing of skin surface and skin excision. It is unclear whether sponge sampling is adequate to remove bacteri...

Sponge and skin excision sampling for recovery of Salmonella and Campylobacter from defeathered broiler carcasses

USDA-ARS?s Scientific Manuscript database

Introduction: Salmonella and Campylobacter contamination of broiler carcass skin increases during feather removal. There are several methods for sampling carcasses including sponging or swabbing of skin surface and skin excision. It is unclear whether sponge sampling is adequate to remove bacteria f...

Microfluidic evaporator for on-chip sample concentration.

PubMed

Casadevall i Solvas, Xavier; Turek, Vladimir; Prodromakis, Themistoklis; Edel, Joshua B

2012-10-21

We present a simple technique for the concentration of liquid samples in microfluidic devices applicable for single or multiple-phase configurations. The strategy consists of capturing the sample of interest within microfluidic traps and breaking its continuity by the introduction of a gas phase, which is also used to evaporate it.

Social and Cognitive Effects of the Introduction of Television on Rural Alaskan Native Children. Final Report.

ERIC Educational Resources Information Center

Forbes, Norma; And Others

A 5-year study of the social and cognitive effects of the introduction of commercial and educational television on rural Alaskan children utilized a variety of social and cognitive measures given to both longitudinal and cross-sectional samples of grade-school children: in 1977, when no participating village received television; in 1979, when half…

Enhancing GPS receiver certification by examining relevant pilot-performance databases : final report.

DOT National Transportation Integrated Search

2000-02-01

The rapid introduction of Global Positioning System (GPS) receivers for airborne navigation has outpaced the capacity of international aviation authorities to resolve human factors issues that concern safe and efficient use of such devices. Current c...

78 FR 1906 - Self-Regulatory Organizations; NASDAQ OX PHLX LLC; Order Approving Proposed Rule Change To Amend...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-01-09

... January 3, 2013. I. Introduction On October 31, 2012, NASDAQ OMX PHLX LLC (``Exchange'' or ``Phlx'') filed... traded data would provide statistical information on spreads and efficiency, which would allow the...

Monitoring hydrilla using two RAPD procedures and the nonindigenous aquatic species database

USGS Publications Warehouse

Madeira, Paul T.; Jacono, C.C.; Van, Thai K.

2000-01-01

Hydrilla (Hydrilla verticillata (L.f.) Royle), an invasive aquatic weed, continues to spread to new regions in the United States. Two biotypes, one a female dioecious and the other monoecious have been identified. Management of the spread of hydrilla requires understanding the mechanisms of introduction and transport, an ability to map and make available information on distribution, and tools to distinguish the known U.S. biotypes as well as potential new introductions. Review of the literature and discussions with aquatic scientists and resource managers point to the aquarium and water garden plant trades as the primary past mechanism for the regional dispersal of hydrilla while local dispersal is primarily carried out by other mechanisms such as boat traffic, intentional introductions, and waterfowl. The Nonindigenous Aquatic Species (NAS) database is presented as a tool for assembling, geo-referencing, and making available information on the distribution of hydrilla. A map of the current range of dioecious and monoecious hydrilla by drainage is presented. Four hydrilla samples, taken from three discrete, non-contiguous regions (Pennsylvania, Connecticut, and Washington State) were examined using two RAPD assays. The first, generated using primer Operon G17, and capable of distinguishing the dioecious and monoecious U.S. biotypes, indicated all four samples were of the monoecious biotype. Results of the second assay using the Stoffel fragment and 5 primers, produced 111 markers, indicated that these samples do not represent new foreign introductions. The differences in the monoecious and dioecious growth habits and management are discussed.

Determination of As, Se, and Hg in fuel samples by in-chamber chemical vapor generation ICP OES using a Flow Blurring® multinebulizer.

PubMed

García, Miriam; Aguirre, Miguel Ángel; Canals, Antonio

2017-09-01

In this work, a new and simple analytical methodology based on in-chamber chemical vapor generation has been developed for the spectrochemical analysis of commercial fuel samples. A multiple nebulizer with three nebulization units has been employed for this purpose: One unit was used for sample introduction, while the other two were used for the necessary reagent introduction. In this way, the aerosols were mixed inside the spray chamber. Through this method, analyte transport and, therefore, sensitivity are improved in inductively coupled plasma-optical emission spectrometry. The factors (i.e., variables), influencing chemical vapor generation, have been optimized using a multivariate approach. Under optimum chemical vapor generation conditions ([NaBH 4 ] = 1.39%, [HCl] = 2.97 M, total liquid flow = 936 μL min -1 ), the proposed sample introduction system allowed the determination of arsenic, selenium, and mercury up to 5 μg g -1 with a limit of detection of 25, 140, and 13 μg kg -1 , respectively. Analyzing spiked commercial fuel samples, recovery values obtained were between 96 and 113%, and expanded uncertainty values ranged from 4 to 16%. The most striking practical conclusion of this investigation is that no carbon deposit appears on the plasma torch after extended periods of working. Graphical abstract A new and simple analytical methodology based on in-chamber chemical vapor generation has been developed for the spectrochemical analysis of commercial fuel samples in ICP OES.

Eco-development and energy efficient technologies in Russia: prospects and reality

NASA Astrophysics Data System (ADS)

Kurakova, Oksana

2017-10-01

The article highlights the concept of eco-standards in Russia, and discusses new technologies that allow to build energy-efficient houses in the form of countryside real estate. Special attention is given to the principle of heat production based on the use of individual facilities, power centers mini thermal power plants, as well as to ways to reduce water consumption at home. Presents analysis of the advantages projects “built-to-suit” for the introduction of the energy efficient technologies. Justified idea and principles of “green construction” in Russia in the real estate market. Conclusion about the effectiveness of the use, opportunities and development of energy efficient technologies.

Development of a new multi-residue laser diode thermal desorption atmospheric pressure chemical ionization tandem mass spectrometry method for the detection and quantification of pesticides and pharmaceuticals in wastewater samples.

PubMed

Boisvert, Michel; Fayad, Paul B; Sauvé, Sébastien

2012-11-19

A new solid phase extraction (SPE) method coupled to a high throughput sample analysis technique was developed for the simultaneous determination of nine selected emerging contaminants in wastewater (atrazine, desethylatrazine, 17β-estradiol, ethynylestradiol, norethindrone, caffeine, carbamazepine, diclofenac and sulfamethoxazole). We specifically included pharmaceutical compounds from multiple therapeutic classes, as well as pesticides. Sample pre-concentration and clean-up was performed using a mixed-mode SPE cartridge (Strata ABW) having both cation and anion exchange properties, followed by analysis by laser diode thermal desorption atmospheric pressure chemical ionization coupled to tandem mass spectrometry (LDTD-APCI-MS/MS). The LDTD interface is a new high-throughput sample introduction method, which reduces total analysis time to less than 15s per sample as compared to minutes with traditional liquid-chromatography coupled to tandem mass spectrometry (LC-MS/MS). Several SPE parameters were evaluated in order to optimize recovery efficiencies when extracting analytes from wastewater, such as the nature of the stationary phase, the loading flow rate, the extraction pH, the volume and composition of the washing solution and the initial sample volume. The method was successfully applied to real wastewater samples from the primary sedimentation tank of a municipal wastewater treatment plant. Recoveries of target compounds from wastewater ranged from 78% to 106%, the limit of detection ranged from 30 to 122ng L(-1) while the limit of quantification ranged from 90 to 370ng L(-1). Calibration curves in the wastewater matrix showed good linearity (R(2)≥0.991) for all target analytes and the intraday and interday coefficient of variation was below 15%, reflecting a good precision. Copyright © 2012 Elsevier B.V. All rights reserved.

Recommendations for representative ballast water sampling

NASA Astrophysics Data System (ADS)

Gollasch, Stephan; David, Matej

2017-05-01

Until now, the purpose of ballast water sampling studies was predominantly limited to general scientific interest to determine the variety of species arriving in ballast water in a recipient port. Knowing the variety of species arriving in ballast water also contributes to the assessment of relative species introduction vector importance. Further, some sampling campaigns addressed awareness raising or the determination of organism numbers per water volume to evaluate the species introduction risk by analysing the propagule pressure of species. A new aspect of ballast water sampling, which this contribution addresses, is compliance monitoring and enforcement of ballast water management standards as set by, e.g., the IMO Ballast Water Management Convention. To achieve this, sampling methods which result in representative ballast water samples are essential. We recommend such methods based on practical tests conducted on two commercial vessels also considering results from our previous studies. The results show that different sampling approaches influence the results regarding viable organism concentrations in ballast water samples. It was observed that the sampling duration (i.e., length of the sampling process), timing (i.e., in which point in time of the discharge the sample is taken), the number of samples and the sampled water quantity are the main factors influencing the concentrations of viable organisms in a ballast water sample. Based on our findings we provide recommendations for representative ballast water sampling.

Computational Modeling of the Spatial Distribution and Temporal Decay of Geomagnetically Trapped Debris of a High Altitude Nuclear Detonation

DTIC Science & Technology

2007-06-01

effects of the magnetic bubble on the dispersion and trapping efficiency of the particles is studied and reported. 15. NUMBER OF PAGES 263 14...efficiency of the particles is studied and reported. vi THIS PAGE INTENTIONALLY LEFT BLANK vii TABLE OF CONTENTS I. INTRODUCTION...single and much lower yield nuclear weapons at many different altitudes. The conclusion of our study and research at USSTRATCOM was that a modeling

A Versatile Integrated Ambient Ionization Source Platform.

PubMed

Ai, Wanpeng; Nie, Honggang; Song, Shiyao; Liu, Xiaoyun; Bai, Yu; Liu, Huwei

2018-04-30

The pursuit of high-throughput sample analysis from complex matrix demands development of multiple ionization techniques with complementary specialties. A versatile integrated ambient ionization source (iAmIS) platform is proposed in this work, based on the idea of integrating multiple functions, enhancing the efficiency of current ionization techniques, extending the applications, and decreasing the cost of the instrument. The design of the iAmIS platform combines flowing atmospheric pressure afterglow (FAPA) source/direct analysis in real time (DART), dielectric barrier discharge ionization (DBDI)/low-temperature plasma (LTP), desorption electrospray ionization (DESI), and laser desorption (LD) technique. All individual and combined ionization modes can be easily attained by modulating parameters. In particular, the FAPA/DART&DESI mode can realize the detection of polar and nonpolar compounds at the same time with two different ionization mechanisms: proton transfer and charge transfer. The introduction of LD contributes to the mass spectrometry imaging and the surface-assisted laser desorption (SALDI) under ambient condition. Compared with other individual or multi-mode ion source, the iAmIS platform provides the flexibility of choosing different ionization modes, broadens the scope of the analyte detection, and facilitates the analysis of complex samples. Graphical abstract ᅟ.

Iodine speciation in coastal and inland bathing waters and seaweeds extracts using a sequential injection standard addition flow-batch method.

PubMed

Santos, Inês C; Mesquita, Raquel B R; Bordalo, Adriano A; Rangel, António O S S

2015-02-01

The present work describes the development of a sequential injection standard addition method for iodine speciation in bathing waters and seaweeds extracts without prior sample treatment. Iodine speciation was obtained by assessing the iodide and iodate content, the two inorganic forms of iodine in waters. For the determination of iodide, an iodide ion selective electrode (ISE) was used. The indirect determination of iodate was based on the spectrophotometric determination of nitrite (Griess reaction). For the iodate measurement, a mixing chamber was employed (flow batch approach) to explore the inherent efficient mixing, essential for the indirect determination of iodate. The application of the standard addition method enabled detection limits of 0.14 µM for iodide and 0.02 µM for iodate, together with the direct introduction of the target water samples, coastal and inland bathing waters. The results obtained were in agreement with those obtained by ICP-MS and a colorimetric reference procedure. Recovery tests also confirmed the accuracy of the developed method which was effectively applied to bathing waters and seaweed extracts. Copyright © 2014 Elsevier B.V. All rights reserved.

A Versatile Integrated Ambient Ionization Source Platform

NASA Astrophysics Data System (ADS)

Ai, Wanpeng; Nie, Honggang; Song, Shiyao; Liu, Xiaoyun; Bai, Yu; Liu, Huwei

2018-04-01

The pursuit of high-throughput sample analysis from complex matrix demands development of multiple ionization techniques with complementary specialties. A versatile integrated ambient ionization source (iAmIS) platform is proposed in this work, based on the idea of integrating multiple functions, enhancing the efficiency of current ionization techniques, extending the applications, and decreasing the cost of the instrument. The design of the iAmIS platform combines flowing atmospheric pressure afterglow (FAPA) source/direct analysis in real time (DART), dielectric barrier discharge ionization (DBDI)/low-temperature plasma (LTP), desorption electrospray ionization (DESI), and laser desorption (LD) technique. All individual and combined ionization modes can be easily attained by modulating parameters. In particular, the FAPA/DART&DESI mode can realize the detection of polar and nonpolar compounds at the same time with two different ionization mechanisms: proton transfer and charge transfer. The introduction of LD contributes to the mass spectrometry imaging and the surface-assisted laser desorption (SALDI) under ambient condition. Compared with other individual or multi-mode ion source, the iAmIS platform provides the flexibility of choosing different ionization modes, broadens the scope of the analyte detection, and facilitates the analysis of complex samples. [Figure not available: see fulltext.

Co-Optimization of Fuels & Engines: Misfueling Mitigation

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

Sluder, C. Scott; Moriarty, Kristi; Jehlik, Forrest

This report examines diesel/gasoline misfueling, leaded/unleaded gasoline misfueling, E85/E15/E10 misfueling, and consumer selection of regular grade fuel over premium grade fuel in an effort to evaluate misfueling technologies that may be needed to support the introduction of vehicles optimized for a new fuel in the marketplace. This is one of a series of reports produced as a result of the Co-Optimization of Fuels & Engines (Co-Optima) project, a Department of Energy-sponsored multi-agency project to accelerate the introduction of affordable, scalable, and sustainable biofuels and high-efficiency, low-emission vehicle engines.

Advances in yeast genome engineering.

PubMed

David, Florian; Siewers, Verena

2015-02-01

Genome engineering based on homologous recombination has been applied to yeast for many years. However, the growing importance of yeast as a cell factory in metabolic engineering and chassis in synthetic biology demands methods for fast and efficient introduction of multiple targeted changes such as gene knockouts and introduction of multistep metabolic pathways. In this review, we summarize recent improvements of existing genome engineering methods, the development of novel techniques, for example for advanced genome redesign and evolution, and the importance of endonucleases as genome engineering tools. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permission@oup.com.

Crisis as a serendipity for change in Cyprus' healthcare services.

PubMed

Petrou, Panagiotis

2015-01-01

As Cyprus signed a financial agreement with a team of international lenders, several reform measures were outlined as pre-requisites for disbursement of financial instalments. The health sector was massively reformed in order to enhance efficiency and reduce waste. The magnitude of reforms included introduction of guidelines and clinical algorithms, co-payments, and revision of criteria for public beneficiary status. In order to safeguard equity in access, solidarity in coverage and sustainability of its healthcare sector, reforms must continue unabated and, more importantly, the introduction of a universal health system should be the ultimate goal.

Bulk- and surface-modified combinable PDMS capillary sensor array as an easy-to-use sensing device with enhanced sensitivity to elevated concentrations of multiple serum sample components.

PubMed

Fujii, Yuji; Henares, Terence G; Kawamura, Kunio; Endo, Tatsuro; Hisamoto, Hideaki

2012-04-21

To enhance sensitivity and facilitate easy sample introduction into a combinable poly(dimethylsiloxane) (PDMS) capillary (CPC) sensor array, PDMS was modified in bulk and on its surface to prepare "black" PDMS coated with a silver layer and self-assembled monolayer (SAM). India ink, a traditional Japanese black ink, was added to the PDMS pre-polymer for bulk modification. The surface was modified by a silver mirror reaction followed by SAM formation using cysteine. These modifications enhanced the fluorescence signals by reflecting them from the surface and reducing background interference. A decrease in the water contact angle led to enhanced sensitivity and easy sample introduction. Furthermore, a CPC sensor array for multiplex detection of serum sample components was prepared that could quantify the analytes glucose, potassium, and alkaline phosphatase (ALP). When serum samples were introduced by capillary action, the CPC sensor array showed fluorescence responses for each analyte and successfully identified the components with elevated concentrations in the serum samples.

Introduction: Alternative Public School Financing.

ERIC Educational Resources Information Center

Disend, David S., Ed.

2000-01-01

Argues that time and money are the two critical resources to allocate in any plan, and certainly regarding public education. Discusses four important elements in the debate about the use of resources: efficiency, content, effectiveness, and fairness. Outlines difficulties and questions regarding school funding. (SR)

Development of genome-wide SNP assays for rice

USDA-ARS?s Scientific Manuscript database

With the introduction of new sequencing technologies, single nucleotide polymorphisms (SNPs) are rapidly replacing simple sequence repeats (SSRs) as the DNA marker of choice for applications in plant breeding and genetics because they are more abundant, stable, amenable to automation, efficient, and...

Two intelligent spraying systems developed for tree crop production

USDA-ARS?s Scientific Manuscript database

Precision pesticide application technologies are needed to achieve efficient and effective spray deposition on target areas and minimize off-target losses. Two variable-rate intelligent sprayers were developed as an introduction of new generation sprayers for tree crop applications. The first spraye...

Protein tetrazinylation via diazonium coupling for covalent and catalyst-free bioconjugation.

PubMed

Zhang, Jie; Men, Yuwen; Lv, Shanshan; Yi, Long; Chen, Jian-Feng

2015-12-21

An efficient and bench-stable reagent was synthesized for direct and covalent introduction of tetrazines onto target protein or virus surfaces, which can be further modified based on tetrazine-ene ligation to achieve fluorescence labelling or PEGylation under mild conditions.

Chapter 1: Introduction. The Uniform Methods Project: Methods for Determining Energy-Efficiency Savings for Specific Measures

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

Li, Michael; Haeri, Hossein; Reynolds, Arlis

This chapter provides a set of model protocols for determining energy and demand savings that result from specific energy efficiency measures implemented through state and utility efficiency programs. The methods described here are approaches that are or are among the most commonly used and accepted in the energy efficiency industry for certain measures or programs. As such, they draw from the existing body of research and best practices for energy efficiency program evaluation, measurement, and verification (EM&V). These protocols were developed as part of the Uniform Methods Project (UMP), funded by the U.S. Department of Energy (DOE). The principal objectivemore » for the project was to establish easy-to-follow protocols based on commonly accepted methods for a core set of widely deployed energy efficiency measures.« less

P. falciparum infection and maternofetal antibody transfer in malaria-endemic settings of varying transmission

PubMed Central

Stanisic, Danielle; McGready, Rose; Chotivanich, Kesinee; Clapham, Caroline; Baiwog, Francesca; Pimanpanarak, Mupawjay; Siba, Peter; Mueller, Ivo; King, Christopher L.; Nosten, François; Beeson, James G.; Rogerson, Stephen; Simpson, Julie A.; Fowkes, Freya J. I.

2017-01-01

Introduction During pregnancy, immunoglobulin G (IgG) is transferred from the mother to the fetus, providing protection from disease in early infancy. Plasmodium falciparum infections may reduce maternofetal antibody transfer efficiency, but mechanisms remain unclear. Methods Mother-cord paired serum samples collected at delivery from Papua New Guinea (PNG) and the Thailand-Myanmar Border Area (TMBA) were tested for IgG1 and IgG3 to four P. falciparum antigens and measles antigen, as well as total serum IgG. Multivariable linear regression was conducted to assess the association of peripheral P. falciparum infection during pregnancy or placental P. falciparum infection assessed at delivery with maternofetal antibody transfer efficiency. Path analysis assessed the extent to which associations between P. falciparum infection and antibody transfer were mediated by gestational age at delivery or levels of maternal total serum IgG. Results Maternofetal antibody transfer efficiency of IgG1 and IgG3 was lower in PNG compared to TMBA (mean difference in cord antibody levels (controlling for maternal antibody levels) ranged from -0.88 to 0.09, median of -0.20 log2 units). Placental P. falciparum infections were associated with substantially lower maternofetal antibody transfer efficiency in PNG primigravid women (mean difference in cord antibody levels (controlling for maternal antibody levels) ranged from -0.62 to -0.10, median of -0.36 log2 units), but not multigravid women. The lower antibody transfer efficiency amongst primigravid women with placental infection was only partially mediated by gestational age at delivery (proportion indirect effect ranged from 0% to 18%), whereas no mediation effects of maternal total serum IgG were observed. Discussion Primigravid women may be at risk of impaired maternofetal antibody transport with placental P. falciparum infection. Direct effects of P. falciparum on the placenta, rather than earlier gestational age and elevated serum IgG, are likely responsible for the majority of the reduction in maternofetal antibody transfer efficiency with placental infection. PMID:29028827

Evaluation of performance and impacts of maternal and child health hospital services using Data Envelopment Analysis in Guangxi Zhuang Autonomous Region, China: a comparison study among poverty and non-poverty county level hospitals.

PubMed

Wang, Xuan; Luo, Hongye; Qin, Xianjin; Feng, Jun; Gao, Hongda; Feng, Qiming

2016-08-23

As the core of the county-level Maternal and Child Health Hospitals (MCHH) in rural areas of China, the service efficiency affects the fairness and availability of healthcare services. This study aims to identify the determinants of hospital efficiency and explore how to improve the performance of MCHH in terms of productivity and efficiency. Data was collected from a sample of 32 county-level MCHHs of Guangxi in 2014. Firstly, we specified and measured the indicators of the inputs and outputs which represent hospital resources expended and its profiles respectively. Then we estimated the efficiency scores using Data Envelopment Analysis (DEA) for each hospital. Efficiency scores were decomposed into technical, scale and congestion components, and the potential output increases and/or input reductions were also estimated in this model, which would make relatively inefficient hospitals more efficient. In the second stage, the estimated efficiency scores are regressed against hospital external and internal environment factors using a Tobit model. We used DEAP (V2.1) and R for data analysis. The average scores of technical efficiency, net technical efficiency (managerial efficiency) and scale efficiency of the hospitals were 0.875, 0.922 and 0.945, respectively. Half of the hospitals were efficient, and 9.4 % and 40.6 % were weakly efficient and inefficient, respectively. Among the low-productiveness hospitals, 61.1 % came from poor counties (Poor counties in this article are in the list of key poverty-stricken counties at the national level, published by The State Council Leading Group Office of Poverty Alleviation and Development, 2012). The total input indicated that redundant medical resources in poverty areas were significantly higher than those in non-poverty areas. The Tobit regression model showed that the technical efficiency was proportional to the total annual incomes, the number of discharge patients, and the number of outpatient and emergency visits, while it was inversely proportional to total expenditure and the actual number of open beds. Technical efficiency was not associated with number of health care workers. The overall operational efficiency of the county-level MCHHs in Guangxi was low and needs to be improved. Regional economic differences affect the performances of hospitals. Health administrations should adjust and optimize the resource investments for the different areas. For the hospitals in poverty areas, policy-makers should not only consider the hardware facilities investment, but also the introduction of advanced techniques and high-level medical personnel to improve their technical efficiency.

Practical limitations of single particle ICP-MS in the determination of nanoparticle size distributions and dissolution: case of rare earth oxides.

PubMed

Fréchette-Viens, Laurie; Hadioui, Madjid; Wilkinson, Kevin J

2017-01-15

The applicability of single particle ICP-MS (SP-ICP-MS) for the analysis of nanoparticle size distributions and the determination of particle numbers was evaluated using the rare earth oxide, La 2 O 3 , as a model particle. The composition of the storage containers, as well as the ICP-MS sample introduction system were found to significantly impact SP-ICP-MS analysis. While La 2 O 3 nanoparticles (La 2 O 3 NP) did not appear to interact strongly with sample containers, adsorptive losses of La 3+ (over 24h) were substantial (>72%) for fluorinated ethylene propylene bottles as opposed to polypropylene (<10%). Furthermore, each part of the sample introduction system (nebulizers made of perfluoroalkoxy alkane (PFA) or glass, PFA capillary tubing, and polyvinyl chloride (PVC) peristaltic pump tubing) contributed to La 3+ adsorptive losses. On the other hand, the presence of natural organic matter in the nanoparticle suspensions led to a decreased adsorptive loss in both the sample containers and the introduction system, suggesting that SP-ICP-MS may nonetheless be appropriate for NP analysis in environmental matrices. Coupling of an ion-exchange resin to the SP-ICP-MS led to more accurate determinations of the La 2 O 3 NP size distributions. Copyright © 2016 Elsevier B.V. All rights reserved.

Feeding Practices and Infant Growth: Quantifying the Effects of Breastfeeding Termination and Complementary Food Introduction on BMI z-Score Growth Velocity through Growth Curve Models.

PubMed

Horodynski, Mildred A; Pierce, Steven J; Reyes-Gastelum, David; Olson, Beth; Shattuck, Mackenzie

2017-12-01

Infant feeding practices are a focus of early obesity prevention. We tested whether infant growth velocity increased after breastfeeding termination and complementary food introduction. Our secondary analysis included a sample of 547 mother-infant dyads from a longitudinal randomized controlled trial conducted in Michigan and Colorado. Infant anthropometrics at birth, baseline, and 6- and 12-month follow-up were standardized to BMI-for-age z-score (ZBMI) according to World Health Organization (WHO) growth charts. We used growth curve models with time-varying predictors to quantify effects of breastfeeding termination and timing of complementary food introduction on growth velocity. Median breastfeeding duration was 2.0 months [confidence interval (CI) = 2.0-2.5]; median introduction of complementary foods occurred at 3.0 months (CI = 2.8-3.2). Breastfed infants not yet introduced to complementary foods had an average ZBMI growth velocity of 0.050 (CI = -0.013 to 0.113) z-score units per month [zpm], not significantly faster than WHO growth trajectory (p = 0.118) defined as 0 zpm. Breastfeeding termination had negligible effect on ZBMI growth velocity (γ 11  = 0.001, CI = -0.027 to 0.030, p = 0.927). Introduction of complementary foods increased ZBMI growth velocity relative to an average child in the sample, but not significantly (γ 12  = 0.033, CI = -0.034 to 0.100, p = 0.334). Growth velocities for infants receiving complementary foods both before and after breastfeeding termination were significantly faster than the WHO growth trajectory (0.083 zpm, CI = 0.052-0.114, and 0.084 zpm, CI = 0.064-0.105, respectively, p's < 0.001). Average postcomplementary food introduction growth velocity was significantly higher than WHO growth trajectory, but did not differ from the sample's initial average trajectory. Growth curve models can accurately estimate effects of feeding practices on infant growth to direct obesity prevention efforts.

Interrogating the variation of element masses and distribution patterns in single cells using ICP-MS with a high efficiency cell introduction system.

PubMed

Wang, Hailong; Wang, Meng; Wang, Bing; Zheng, Lingna; Chen, Hanqing; Chai, Zhifang; Feng, Weiyue

2017-02-01

Cellular heterogeneity is an inherent condition of cell populations, which results from stochastic expression of genes, proteins, and metabolites. The heterogeneity of individual cells can dramatically influence cellular decision-making and cell fate. So far, our knowledge about how the variation of endogenous metals and non-metals in individual eukaryotic cells is limited. In this study, ICP-MS equipped with a high efficiency cell introduction system (HECIS) was developed as a method of single-cell ICP-MS (SC-ICP-MS). The method was applied to the single-cell analysis of Mn, Fe, Co, Cu, Zn, P, and S in human cancer cell lines (HeLa and A549) and normal human bronchial epithelial cell line (16HBE). The analysis showed obvious variation of the masses of Cu, Fe, Zn, and P in individual HeLa cells, and variation of Fe, Zn, and P in individual A549 cells. On the basis of the single-cell data, a multimodal distribution of the elements in the cell population was fitted, which showed marked differences among the various cell lines. Importantly, subpopulations of the elements were found in the cell populations, especially in the HeLa cancer cells. This study demonstrates that SC-ICP-MS is able to unravel the extent of variation of endogenous elements in individual cells, which will help to improve our fundamental understanding of cellular biology and reveal novel insights into human biology and medicine. Graphical abstract The variations of masses and distribution patterns of elements Mn, Fe, Co, Cu, Zn, P, and S in single cells were successfully detected by ICP-MS coupled with a high efficiency cell introduction system (HECIS).

Pseudolinear gradient ultrahigh-pressure liquid chromatography using an injection valve assembly.

PubMed

Xiang, Yanqiao; Liu, Yansheng; Stearns, Stanley D; Plistil, Alex; Brisbin, Martin P; Lee, Milton L

2006-02-01

The use of ultrahigh pressures in liquid chromatography (UHPLC) imposes stringent requirements on hardware such as pumps, valves, injectors, connecting tubing, and columns. One of the most difficult components of the UHPLC system to develop has been the sample injector. Static-split injection, which can be performed at pressures up to 6900 bar (100,000 psi), consumes a large sample volume and is very irreproducible. A pressure-balanced injection valve provided better reproducibility, shorter injection time, reduced sample consumption, and greater ease of use; however, it could only withstand pressures up to approximately 1000 bar (15,000 psi). In this study, a new injection valve assembly that can operate at pressures as high as 2070 bar (30,000 psi) was evaluated for UHPLC. This assembly contains six miniature electronically controlled needle valves to provide accurate and precise volumes for introduction into the capillary LC column. It was found that sample volumes as small as several tenths of a nanoliter can be injected, which are comparable to the results obtained from the static-split injector. The reproducibilities of retention time, efficiency, and peak area were investigated, and the results showed that the relative standard deviations of these parameters were small enough for quantitative analyses. Separation experiments using the UHPLC system with this new injection valve assembly showed that this new injector is suitable for both isocratic and gradient operation modes. A newly designed capillary connector was used at a pressure as high as 2070 bar (30,000 psi).

Molecular dynamics based enhanced sampling of collective variables with very large time steps.

PubMed

Chen, Pei-Yang; Tuckerman, Mark E

2018-01-14

Enhanced sampling techniques that target a set of collective variables and that use molecular dynamics as the driving engine have seen widespread application in the computational molecular sciences as a means to explore the free-energy landscapes of complex systems. The use of molecular dynamics as the fundamental driver of the sampling requires the introduction of a time step whose magnitude is limited by the fastest motions in a system. While standard multiple time-stepping methods allow larger time steps to be employed for the slower and computationally more expensive forces, the maximum achievable increase in time step is limited by resonance phenomena, which inextricably couple fast and slow motions. Recently, we introduced deterministic and stochastic resonance-free multiple time step algorithms for molecular dynamics that solve this resonance problem and allow ten- to twenty-fold gains in the large time step compared to standard multiple time step algorithms [P. Minary et al., Phys. Rev. Lett. 93, 150201 (2004); B. Leimkuhler et al., Mol. Phys. 111, 3579-3594 (2013)]. These methods are based on the imposition of isokinetic constraints that couple the physical system to Nosé-Hoover chains or Nosé-Hoover Langevin schemes. In this paper, we show how to adapt these methods for collective variable-based enhanced sampling techniques, specifically adiabatic free-energy dynamics/temperature-accelerated molecular dynamics, unified free-energy dynamics, and by extension, metadynamics, thus allowing simulations employing these methods to employ similarly very large time steps. The combination of resonance-free multiple time step integrators with free-energy-based enhanced sampling significantly improves the efficiency of conformational exploration.

Molecular dynamics based enhanced sampling of collective variables with very large time steps

NASA Astrophysics Data System (ADS)

Chen, Pei-Yang; Tuckerman, Mark E.

2018-01-01

Enhanced sampling techniques that target a set of collective variables and that use molecular dynamics as the driving engine have seen widespread application in the computational molecular sciences as a means to explore the free-energy landscapes of complex systems. The use of molecular dynamics as the fundamental driver of the sampling requires the introduction of a time step whose magnitude is limited by the fastest motions in a system. While standard multiple time-stepping methods allow larger time steps to be employed for the slower and computationally more expensive forces, the maximum achievable increase in time step is limited by resonance phenomena, which inextricably couple fast and slow motions. Recently, we introduced deterministic and stochastic resonance-free multiple time step algorithms for molecular dynamics that solve this resonance problem and allow ten- to twenty-fold gains in the large time step compared to standard multiple time step algorithms [P. Minary et al., Phys. Rev. Lett. 93, 150201 (2004); B. Leimkuhler et al., Mol. Phys. 111, 3579-3594 (2013)]. These methods are based on the imposition of isokinetic constraints that couple the physical system to Nosé-Hoover chains or Nosé-Hoover Langevin schemes. In this paper, we show how to adapt these methods for collective variable-based enhanced sampling techniques, specifically adiabatic free-energy dynamics/temperature-accelerated molecular dynamics, unified free-energy dynamics, and by extension, metadynamics, thus allowing simulations employing these methods to employ similarly very large time steps. The combination of resonance-free multiple time step integrators with free-energy-based enhanced sampling significantly improves the efficiency of conformational exploration.

Estimating means and variances: The comparative efficiency of composite and grab samples.

PubMed

Brumelle, S; Nemetz, P; Casey, D

1984-03-01

This paper compares the efficiencies of two sampling techniques for estimating a population mean and variance. One procedure, called grab sampling, consists of collecting and analyzing one sample per period. The second procedure, called composite sampling, collectsn samples per period which are then pooled and analyzed as a single sample. We review the well known fact that composite sampling provides a superior estimate of the mean. However, it is somewhat surprising that composite sampling does not always generate a more efficient estimate of the variance. For populations with platykurtic distributions, grab sampling gives a more efficient estimate of the variance, whereas composite sampling is better for leptokurtic distributions. These conditions on kurtosis can be related to peakedness and skewness. For example, a necessary condition for composite sampling to provide a more efficient estimate of the variance is that the population density function evaluated at the mean (i.e.f(μ)) be greater than[Formula: see text]. If[Formula: see text], then a grab sample is more efficient. In spite of this result, however, composite sampling does provide a smaller estimate of standard error than does grab sampling in the context of estimating population means.

Historical perspective of barriers to achieving high-efficiency silicon solar cells

NASA Technical Reports Server (NTRS)

Lindmayer, J.

1985-01-01

Early silicon solar cells were made of metallurgical-grade silicon with very low efficiency. The single-crystal silicon introduced in the mid-50's increased the efficiency to the 5% to 10% region. Throughout the 1960s the technology of the 2 x 2 cm or 2 x 4 cm space solar cell with 10% efficiency was established. In the early 1970s work related to the violet cell upset the status quo and space solar cells and cells in general became more efficient. The rest of the decade became characterized by establishing a terrestrial photovoltaic technology to support the development of a new industry. Costs per watt became the dominant consideration and frequently the efficiency was compromised. The introduction of materials and other forms of silicon dropped the efficiency and it is now a state of mine that accomplishing 10% efficiency with some alternative combination is regarded as success. Silicon solar cells are capable of delivering efficiences much greater than 10%.

Adult Learning in Executive Development Programs

ERIC Educational Resources Information Center

Wuestewald, Todd

2016-01-01

Executive development programs (EDPs) have undergone significant change since their introduction in the early 20th century. As an adjunct or alternative to traditional education, EDPs are considered an efficient means of imparting critical, functional, and social-behavior skills to current and future organizational leaders. Consequently, such…

Safety of lithium nickel cobalt aluminum oxide battery packs in transit bus applications : final report.

DOT National Transportation Integrated Search

2016-10-01

The future of mass transportation is clearly moving toward the increased efficiency and greenhouse gas reduction of hybrid and electric vehicles. With the introduction of high-power/high-energy storage devices such as lithium ion battery systems serv...

Optimal Budget Allocation for Sample Average Approximation

DTIC Science & Technology

2011-06-01

an optimization algorithm applied to the sample average problem. We examine the convergence rate of the estimator as the computing budget tends to...regime for the optimization algorithm . 1 Introduction Sample average approximation (SAA) is a frequently used approach to solving stochastic programs...appealing due to its simplicity and the fact that a large number of standard optimization algorithms are often available to optimize the resulting sample

Evaluating the efficiency of a one-square-meter quadrat sampler for riffle-dwelling fish

USGS Publications Warehouse

Peterson, J.T.; Rabeni, C.F.

2001-01-01

We evaluated the efficacy of a 1-m2 quadrat sampler for collecting riffle-dwelling fishes in an Ozark stream. We used a dual-gear approach to evaluate sampler efficiency in relation to species, fish size, and habitat variables. Quasi-likelihood regression showed sampling efficiency to differ significantly (P 0.05). Sampling efficiency was significantly influenced by physical habitat characteristics. Mean current velocity negatively influenced sampling efficiencies for Cyprinidae (P = 0.009), Cottidae (P = 0.006), and Percidae (P < 0.001), and the amount of cobble substrate negatively influenced sampling efficiencies for Cyprinidae (P = 0.025), Ictaluridae (P < 0.001), and Percidae (P < 0.001). Water temperature negatively influenced sampling efficiency for Cyprinidae (P = 0.009) and Ictaluridae (P = 0.006). Species-richness efficiency was positively influenced (P = 0.002) by percentage of riffle sampled. Under average habitat conditions encountered in stream riffles, the 1-m2 quadrat sampler was most efficient at estimating the densities of Cyprinidae (84%) and Cottidae (80%) and least efficient for Percidae (57%) and Ictaluridae (31%).

Mississippi Magic: Summer Library Program, 1999.

ERIC Educational Resources Information Center

Hudspeth, Jean; Shurden, Lynn Fletcher

This manual for the 1999 Mississippi summer library program for preschool through elementary age children contains the following sections: (1) Introduction, including planning, promotional activities, sample radio spots and press releases, sample letters to parents, tips for including children with disabilities, a general bibliography, a…

Time Resolved Efficiency Degradation in Potassium Diode Pumped Alkali Laser

DTIC Science & Technology

2014-08-07

study of the performance of a Potassium OPAL operating in pulsed mode with pulses up to 5 msec Jong at different pulse energies and cell...temperatures. The experiments showed the OPAL efficiency degradation in time with a characteristic time in the range from 0.5 msec to 4.5 msec. The recorded...Lasers", Optics Express, 19(8), 7894-7902 (20 I I) 1. Introduction There has been extensive research into Diode Pumped Alkali Lasers ( OPALs ) during the

Smart Buildings: An Introduction to the Library of the Future.

PubMed

Hoy, Matthew B

2016-01-01

Advances in building technologies are combining energy efficiency, networked sensors, and data recording in exciting ways. Modern facilities can adjust lighting, heating, and cooling outputs to maximize efficiency, provide better physical security, improve wayfinding for occupants, and provide detailed reports of building use. This column will briefly explore the idea of "smart buildings," describe some of the technologies that are being developed for these buildings, and explore their implications for libraries. A brief listing of selected smart building technologies is also provided.

A Force to Be Reckoned With: A Review of Synthetic Microswimmers Powered by Ultrasound.

PubMed

Rao, K Jagajjanani; Li, Fei; Meng, Long; Zheng, Hairong; Cai, Feiyan; Wang, Wei

2015-06-24

Synthetic microswimmers are a class of artificial nano- or microscale particle capable of converting external energy into motion. They are similar to natural microswimmers such as bacteria in behavior and are, therefore, of great interest to the study of active matter. Additionally, microswimmers show promise in applications ranging from bioanalytics and environmental monitoring to particle separation and drug delivery. However, since their sizes are on the nano-/microscale and their speeds are in the μm s(-1) range, they fall into a low Reynolds number regime where viscosity dominates. Therefore, new propulsion schemes are needed for these microswimmers to be able to efficiently move. Furthermore, many of the hotly pursued applications call for innovations in the next phase of development of biocompatible microswimmers. In this review, the latest developments of microswimmers powered by ultrasound are presented. Ultrasound, especially at MHz frequencies, does little harm to biological samples and provides an advantageous and well-controlled means to efficiently power microswimmers. By critically reviewing the recent progress in this research field, an introduction of how ultrasound propels colloidal particles into autonomous motion is presented, as well as how this propulsion can be used to achieve preliminary but promising applications. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Cluster Sampling with Referral to Improve the Efficiency of Estimating Unmet Needs among Pregnant and Postpartum Women after Disasters

PubMed Central

Horney, Jennifer; Zotti, Marianne E.; Williams, Amy; Hsia, Jason

2015-01-01

Introduction and Background Women of reproductive age, in particular women who are pregnant or fewer than 6 months postpartum, are uniquely vulnerable to the effects of natural disasters, which may create stressors for caregivers, limit access to prenatal/postpartum care, or interrupt contraception. Traditional approaches (e.g., newborn records, community surveys) to survey women of reproductive age about unmet needs may not be practical after disasters. Finding pregnant or postpartum women is especially challenging because fewer than 5% of women of reproductive age are pregnant or postpartum at any time. Methods From 2009 to 2011, we conducted three pilots of a sampling strategy that aimed to increase the proportion of pregnant and postpartum women of reproductive age who were included in postdisaster reproductive health assessments in Johnston County, North Carolina, after tornadoes, Cobb/Douglas Counties, Georgia, after flooding, and Bertie County, North Carolina, after hurricane-related flooding. Results Using this method, the percentage of pregnant and postpartum women interviewed in each pilot increased from 0.06% to 21%, 8% to 19%, and 9% to 17%, respectively. Conclusion and Discussion Two-stage cluster sampling with referral can be used to increase the proportion of pregnant and postpartum women included in a postdisaster assessment. This strategy may be a promising way to assess unmet needs of pregnant and postpartum women in disaster-affected communities. PMID:22365134

Stimulation of Wound Healing by Electroactive, Antibacterial, and Antioxidant Polyurethane/Siloxane Dressing Membranes: In Vitro and in Vivo Evaluations.

PubMed

Gharibi, Reza; Yeganeh, Hamid; Rezapour-Lactoee, Alireza; Hassan, Zuhair M

2015-11-04

A series of novel polyurethane/siloxane-based wound dressing membranes was prepared through sol-gel reaction of methoxysilane end-functionalized urethane prepolymers composed of castor oil and ricinoleic methyl ester as well as methoxysilane functional aniline tetramer (AT) moieties. The samples were fully characterized and their physicochemical, mechanical, electrical, and biological properties were assayed. The biological activity of these dressings against fibroblast cells and couple of microbes was also studied. It was revealed that samples that displayed electroactivity by introduction of AT moieties showed a broad range of antimicrobial activity toward different microorganisms, promising antioxidant (radical scavenging) efficiency and significant activity for stimulation of fibroblast cell growth and proliferation. Meanwhile, these samples showed appropriate tensile strength and ability for maintaining a moist environment over a wound by controlled equilibrium water absorption and water vapor transmission rate. The selected electroactive dressing was subjected to an in vivo assay using a rat animal model and the wound healing process was monitored and compared with analogous dressing without AT moieties. The recorded results showed that the electroactive dressings induced an increase in the rate of wound contraction, promoted collagen deposition, and encouraged vascularization in the wounded area. On the basis of the results of in vitro and in vivo assays, the positive influence of designed dressings for accelerated healing of a wound model was confirmed.

78 FR 37837 - Agency Information Collection Activities: Submission for OMB Review; Comment Request

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-24

... introduction of a new sample design is planned for the 2014 NSDUH. In addition to moving towards a proportional allocation by state, the 2014 sample design places more sample in the 26 or older age groups than in previous... National Drug Control Policy (ONDCP), Federal government agencies, and other organizations and researchers...

National Sample Survey of Registered Nurses II. Status of Nurses: November 1980.

ERIC Educational Resources Information Center

Bentley, Barbara S.; And Others

This report provides data describing the nursing population as determined by the second national sample survey of registered nurses. A brief introduction is followed by a chapter that presents an overview of the survey methodology, including details on the sampling design, the response rate, and the statistical reliability. Chapter 3 provides a…

Scatterometry—fast and robust measurements of nano-textured surfaces

NASA Astrophysics Data System (ADS)

Hannibal Madsen, Morten; Hansen, Poul-Erik

2016-06-01

Scatterometry is a fast, precise and low cost way to determine the mean pitch and dimensional parameters of periodic structures with lateral resolution of a few nanometer. It is robust enough for in-line process control and precise and accurate enough for metrology measurements. Furthermore, scatterometry is a non-destructive technique capable of measuring buried structures, for example a grating covered by a thick oxide layer. As scatterometry is a non-imaging technique, mathematical modeling is needed to retrieve structural parameters that describe a surface. In this review, the three main steps of scatterometry are discussed: the data acquisition, the simulation of diffraction efficiencies and the comparison of data and simulations. First, the intensity of the diffracted light is measured with a scatterometer as a function of incoming angle, diffraction angle and/or wavelength. We discuss the evolution of the scatterometers from the earliest angular scatterometers to the new imaging scatterometers. The basic principle of measuring diffraction efficiencies in scatterometry has remained the same since the beginning, but the instrumental improvements have made scatterometry a state-of-the-art solution for fast and accurate measurements of nano-textured surfaces. The improvements include extending the wavelength range from the visible to the extreme ultra-violet range, development of Fourier optics to measure all diffraction orders simultaneously, and an imaging scatterometer to measure area of interests smaller than the spot size. Secondly, computer simulations of the diffraction efficiencies are discussed with emphasis on the rigorous coupled-wave analysis (RCWA) method. RCWA has, since the mid-1990s, been the preferred method for grating simulations due to the speed of the algorithms. In the beginning the RCWA method suffered from a very slow convergence rate, and we discuss the historical improvements to overcome this challenge, e.g. by the introduction of Li’s factorization rules and the introduction of the normal vector method. The third step is the comparison, where the simulated diffraction efficiencies are compared to the experimental data using an inverse modeling approach. We discuss both a direct optimization scheme using a differential evolution algorithm and a library search strategy where diffraction efficiences of expected structures are collected in a database. For metrology measurements two methods are described for estimating the uncertainty of the fitting parameters. The first method is based on estimating the confidence limits using constant chi square boundaries, which can easily be computed when using the library search strategy. The other method is based on calculating the covariances of all the free parameters using a least square optimization. Scatterometry is already utilized in the semiconductor industry for in-line characterization. However, it also has a large potential for other industrial sectors, including sectors making use of injection molding or roll-2-roll fabrication. Using the library search strategy, the comparison can be performed in ms, making in-line characterization possible and we demonstrate that scatterometry can be used for quality control of injection molded nano-textured plastic samples. With the emerging methods of highly parallel manufacturing of nano-textured devices, scatterometry has great potential to deliver a characterization method for in-line quality control and metrology measurements, which is not possible with conventional characterization techniques. However, there are some open challenges for the scatterometry techniques. These include corrections for measuring on non-ideal samples with a large surface roughness or line-edge roughness and the path towards performing traceable scatterometry measurements.

Advanced functional materials in solid phase extraction for ICP-MS determination of trace elements and their species - A review.

PubMed

He, Man; Huang, Lijin; Zhao, Bingshan; Chen, Beibei; Hu, Bin

2017-06-22

For the determination of trace elements and their species in various real samples by inductively coupled plasma mass spectrometry (ICP-MS), solid phase extraction (SPE) is a commonly used sample pretreatment technique to remove complex matrix, pre-concentrate target analytes and make the samples suitable for subsequent sample introduction and measurements. The sensitivity, selectivity/anti-interference ability, sample throughput and application potential of the methodology of SPE-ICP-MS are greatly dependent on SPE adsorbents. This article presents a general overview of the use of advanced functional materials (AFMs) in SPE for ICP-MS determination of trace elements and their species in the past decade. Herein the AFMs refer to the materials featuring with high adsorption capacity, good selectivity, fast adsorption/desorption dynamics and satisfying special requirements in real sample analysis, including nanometer-sized materials, porous materials, ion imprinting polymers, restricted access materials and magnetic materials. Carbon/silica/metal/metal oxide nanometer-sized adsorbents with high surface area and plenty of adsorption sites exhibit high adsorption capacity, and porous adsorbents would provide more adsorption sites and faster adsorption dynamics. The selectivity of the materials for target elements/species can be improved by using physical/chemical modification, ion imprinting and restricted accessed technique. Magnetic adsorbents in conventional batch operation offer unique magnetic response and high surface area-volume ratio which provide a very easy phase separation, greater extraction capacity and efficiency over conventional adsorbents, and chip-based magnetic SPE provides a versatile platform for special requirement (e.g. cell analysis). The performance of these adsorbents for the determination of trace elements and their species in different matrices by ICP-MS is discussed in detail, along with perspectives and possible challenges in the future development. Copyright © 2017 Elsevier B.V. All rights reserved.

Nanoporous microbead supported bilayers: stability, physical characterization, and incorporation of functional transmembrane proteins.

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

Davis, Ryan W.; Brozik, James A.; Brozik, Susan Marie

2007-03-01

The introduction of functional transmembrane proteins into supported bilayer-based biomimetic systems presents a significant challenge for biophysics. Among the various methods for producing supported bilayers, liposomal fusion offers a versatile method for the introduction of membrane proteins into supported bilayers on a variety of substrates. In this study, the properties of protein containing unilamellar phosphocholine lipid bilayers on nanoporous silica microspheres are investigated. The effects of the silica substrate, pore structure, and the substrate curvature on the stability of the membrane and the functionality of the membrane protein are determined. Supported bilayers on porous silica microspheres show a significant increasemore » in surface area on surfaces with structures in excess of 10 nm as well as an overall decrease in stability resulting from increasing pore size and curvature. Comparison of the liposomal and detergent-mediated introduction of purified bacteriorhodopsin (bR) and the human type 3 serotonin receptor (5HT3R) are investigated focusing on the resulting protein function, diffusion, orientation, and incorporation efficiency. In both cases, functional proteins are observed; however, the reconstitution efficiency and orientation selectivity are significantly enhanced through detergent-mediated protein reconstitution. The results of these experiments provide a basis for bulk ionic and fluorescent dye-based compartmentalization assays as well as single-molecule optical and single-channel electrochemical interrogation of transmembrane proteins in a biomimetic platform.« less

Healthcare reforms in Cyprus 2013-2017: Does the crisis mark the end of the healthcare sector as we know it?

PubMed

Petrou, Panagiotis; Vandoros, Sotiris

2018-02-01

As part of a bailout agreement with the International Monetary Fund, the European Commission and the European Central Bank (known as the Troika), Cyprus had to achieve a fiscal surplus through budget constraints and efficiency enhancement. As a result, a number of policy changes were implemented, including a reform of the healthcare sector, and major healthcare reforms are planned for the upcoming years, mainly via the introduction of a National Health System. This paper presents the healthcare sector, provides an overview of recent reforms, assesses the recently implemented policies and proposes further interventions. Recent reforms targeting the demand and supply side included the introduction of clinical guidelines, user charges, introduction of coding for Diagnosis Related Groups (DRGs) and the revision of public healthcare coverage criteria. The latter led to a reduction in the number of people with public healthcare coverage in a time of financial crises, when this is needed the most, while co-payments must be reassessed to avoid creating barriers to access. However, DRGs and clinical guidelines can help improve performance and efficiency. The changes so far are yet to mark the end of the healthcare sector as we know it. A universal public healthcare system must remain a priority and must be introduced swiftly to address important existing coverage gaps. Copyright © 2017 The Author(s). Published by Elsevier B.V. All rights reserved.

Infant rolling abilities--the same or different 20 years after the back to sleep campaign?

PubMed

Darrah, Johanna; Bartlett, Doreen J

2013-05-01

To compare the order and age of emergence of rolling prone to supine and supine to prone before the introduction of back to sleep guidelines and 20 years after their introduction. The original normative data for the Alberta Infant Motor Scale (AIMS) were collected just prior to the introduction of back to sleep guidelines in 1992. Currently these norms are being re-evaluated. Data of rolling patterns of infants 36 weeks of age or younger from the original sample (n=1114) and the contemporary sample (n=351) were evaluated to compare the sequence of appearance of prone to supine and supine to prone rolls (proportion of infants passing each roll) and the ages of emergence (estimated age when 50% of infants passed each roll). The sequence of emergence and estimated age of appearance of both rolling directions were similar between the two time periods. The introduction of the supine sleep position to reduce the prevalence of Sudden Infant Death Syndrome (SIDS) has not altered the timing or sequence of infant rolling abilities. This information is valuable to health care providers involved in the surveillance of infants' development. Original normative age estimates for these two motor abilities are still appropriate. Copyright © 2012 Elsevier Ltd. All rights reserved.

Globalization, land use and the invasion of West Nile virus

PubMed Central

Kilpatrick, A. Marm

2012-01-01

Many invasive species that have been spread through the globalization of trade and travel are infectious pathogens. A paradigmatic case is the introduction of West Nile virus (WNV) into North America in 1999. A decade of research on the ecology and evolution of WNV includes three findings that provide insight into the outcome of future viral introductions. First, WNV transmission in North America is highest in urbanized and agricultural habitats, in part because the hosts and vectors of WNV are abundant in human-modified areas. Second, after its introduction, the virus quickly adapted to infect local mosquito vectors more efficiently than the originally introduced strain. Third, highly focused feeding patterns of the mosquito vectors of WNV result in unexpected host species being important for transmission. These findings provide a framework for predicting and preventing the emergence of foreign vector-borne pathogens. PMID:22021850

Ensuring successful introduction of Wolbachia in natural populations of Aedes aegypti by means of feedback control.

PubMed

Bliman, Pierre-Alexandre; Aronna, M Soledad; Coelho, Flávio C; da Silva, Moacyr A H B

2018-04-01

The control of the spread of dengue fever by introduction of the intracellular parasitic bacterium Wolbachia in populations of the vector Aedes aegypti, is presently one of the most promising tools for eliminating dengue, in the absence of an efficient vaccine. The success of this operation requires locally careful planning to determine the adequate number of individuals carrying the Wolbachia parasite that need to be introduced into the natural population. The introduced mosquitoes are expected to eventually replace the Wolbachia-free population and guarantee permanent protection against the transmission of dengue to human. In this study, we propose and analyze a model describing the fundamental aspects of the competition between mosquitoes carrying Wolbachia and mosquitoes free of the parasite. We then use feedback control techniques to devise an introduction protocol that is proved to guarantee that the population converges to a stable equilibrium where the totality of mosquitoes carry Wolbachia.

A DUST-SETTLING CHAMBER FOR SAMPLING-INSTRUMENT COMPARISON STUDIES

EPA Science Inventory

Introduction: Few methods exist that can evenly and reproducibly deposit dusts onto surfaces for surface-sampling methodological studies. A dust-deposition chamber was designed for that purpose.

Methods: A 1-m3 Rochester-type chamber was modified to produce high airborne d...

47 CFR 1.363 - Introduction of statistical data.

Code of Federal Regulations, 2010 CFR

2010-10-01

... case of sample surveys, there shall be a clear description of the survey design, including the... evidence in common carrier hearing proceedings, including but not limited to sample surveys, econometric... description of the experimental design shall be set forth, including a specification of the controlled...

47 CFR 1.363 - Introduction of statistical data.

Code of Federal Regulations, 2013 CFR

2013-10-01

... case of sample surveys, there shall be a clear description of the survey design, including the... evidence in common carrier hearing proceedings, including but not limited to sample surveys, econometric... description of the experimental design shall be set forth, including a specification of the controlled...

47 CFR 1.363 - Introduction of statistical data.

Code of Federal Regulations, 2014 CFR

2014-10-01

... case of sample surveys, there shall be a clear description of the survey design, including the... evidence in common carrier hearing proceedings, including but not limited to sample surveys, econometric... description of the experimental design shall be set forth, including a specification of the controlled...

47 CFR 1.363 - Introduction of statistical data.

Code of Federal Regulations, 2012 CFR

2012-10-01

... case of sample surveys, there shall be a clear description of the survey design, including the... evidence in common carrier hearing proceedings, including but not limited to sample surveys, econometric... description of the experimental design shall be set forth, including a specification of the controlled...

47 CFR 1.363 - Introduction of statistical data.

Code of Federal Regulations, 2011 CFR

2011-10-01

... case of sample surveys, there shall be a clear description of the survey design, including the... evidence in common carrier hearing proceedings, including but not limited to sample surveys, econometric... description of the experimental design shall be set forth, including a specification of the controlled...

Magnetic Susceptibility: A Practical Introduction.

ERIC Educational Resources Information Center

Greenaway, A. M.; Trail, L. E.

1983-01-01

Describes an experiment in which students: (1) synthesize tris(acetylacetonato)iron(III), tris(diethyldithiocarbamato)iron(III), and chlorobis(diethyldithiocarbmamato)iron(III); (2) are given a sample of potassium hexocyanoferrate(III); and (3) are then asked to measure the room temperature of these samples using the Guoy technique. Background…

Improved format for radiocardiographic data

NASA Technical Reports Server (NTRS)

Dimeff, J.; Sevelius, G.

1973-01-01

Technique involves introduction of radioactive sample into antecubital vein. Scintillation crystal mounted in collimating housing views portion of right and left hearts. As radioactive sample passes through heart, counting rate is measured by crystal and recorded on strip chart. Data is insensitive to geometric effects and other parameters.

Volatile organic compound concentrations in the South Coast Air Basin (CA) during the summers of 1995 and 1996

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

Zielinska, B.; Harshfield, G.; Fujita, E.

1997-12-31

Volatile organic compounds (VOC) were measured in California`s South Coast Air Basin (SoCAB) during the summers of 1995 and 1996 in order to determine the air quality impacts of the introduction in 1996 of California`s Phase 2 reformulated gasoline (RFG). Over 250 canister and 2,4-dinitrophenylhydrazine (DNPH)-impregnated cartridge samples were collected during each sampling campaign at four sampling sites--two source-dominated sites, a downwind receptor site, and a background site. Canister samples were analyzed for methane, speciated volatile hydrocarbons (C{sub 2}-C{sub 12}), carbon monoxide (CO), carbon dioxide (CO{sub 2}), and methyl tert-butyl ether (MTBE). DNPH were analyzed for C{sub 1}-C{sub 7} carbonylmore » compounds. This paper examines the changes in concentrations of C{sub 2}-C{sub 12} hydrocarbons in the SoCAB resulting from the introduction of Phase 2 RFG with particular emphasis on hydrocarbon species that are most affected by the reformulation.« less

Introduction to Computer Aided Instruction in the Language Laboratory.

ERIC Educational Resources Information Center

Hughett, Harvey L.

The first half of this book focuses on the rationale, ideas, and information for the use of technology, including microcomputers, to improve language teaching efficiency. Topics discussed include foreign language computer assisted instruction (CAI), hardware and software selection, computer literacy, educational computing organizations, ease of…

Low Budget Biology: Genetics Unit.

ERIC Educational Resources Information Center

Wartski, Bert; Wartski, Lynn Marie

Some concepts in genetics are difficult for many students to understand. This document provides hands-on, cost efficient, fun activities for students to help them better understand abstract concepts in genetics. Each activity includes: purpose, introduction, materials, procedures, results and conclusion. Some of the topics explored are: (1)…

Fuel Cell Introduction into a Class 8 Truck

DTIC Science & Technology

2003-09-11

compressor in Its efficient zones, and packeging . lJhile __ l_ooki_flg __ l~~--reP.I~c!ll9_the _ _9_E_...__~~~~!1~~~~-!i.riV.~!’l.~~P.t:e~~--~!f:l

The Comprehensive Competencies Program Reference Manual. Volume I. Introduction.

ERIC Educational Resources Information Center

Taggart, Robert

Chapter 1 of this reference manual is a summary of the comprehensive competencies program (CCP). It describes this system for organizing, implementing, managing, and efficiently delivering individualized self-paced instruction, combined with group and experience-based learning activities, using computer-assisted instruction. (The CCP covers not…

Nanostructured Materials Developed for Solar Cells

NASA Technical Reports Server (NTRS)

Bailey, Sheila G.; Castro, Stephanie L.; Raffaelle, Ryne P.; Fahey, Stephen D.; Gennett, Thomas; Tin, Padetha

2004-01-01

There has been considerable investigation recently regarding the potential for the use of nanomaterials and nanostructures to increase the efficiency of photovoltaic devices. Efforts at the NASA Glenn Research Center have involved the development and use of quantum dots and carbon nanotubes to enhance inorganic and organic cell efficiencies. Theoretical results have shown that a photovoltaic device with a single intermediate band of states resulting from the introduction of quantum dots offers a potential efficiency of 63.2 percent. A recent publication extended the intermediate band theory to two intermediate bands and calculated a limiting efficiency of 71.7 percent. The enhanced efficiency results from converting photons of energy less than the band gap of the cell by an intermediate band. The intermediate band provides a mechanism for low-energy photons to excite carriers across the energy gap by a two-step process.

Trace elemental analysis of glass and paint samples of forensic interest by ICP-MS using laser ablation solid sample introduction

NASA Astrophysics Data System (ADS)

Almirall, Jose R.; Trejos, Tatiana; Hobbs, Andria; Furton, Kenneth G.

2003-09-01

The importance of small amounts of glass and paint evidence as a means to associate a crime event to a suspect or a suspect to another individual has been demonstrated in many cases. Glass is a fragile material that is often found at the scenes of crimes such as burglaries, hit-and-run accidents and violent crime offenses. Previous work has demonstrated the utility of elemental analysis by solution ICP-MS of small amounts of glass for the comparison between a fragment found at a crime scene to a possible source of the glass. The multi-element capability and the sensitivity of ICP-MS combined with the simplified sample introduction of laser ablation prior to ion detection provides for an excellent and relatively non-destructive technique for elemental analysis of glass fragments. The direct solid sample introduction technique of laser ablation (LA) is reported as an alternative to the solution method. Direct solid sampling provides several advantages over solution methods and shows great potential for a number of solid sample analyses in forensic science. The advantages of laser ablation include the simplification of sample preparation, thereby reducing the time and complexity of the analysis, the elimination of handling acid dissolution reagents such as HF and the reduction of sources of interferences in the ionization plasma. Direct sampling also provides for essentially "non-destructive" sampling due to the removal of very small amounts of sample needed for analysis. The discrimination potential of LA-ICP-MS is compared with previously reported solution ICP-MS methods using external calibration with internal standardization and a newly reported solution isotope dilution (ID) method. A total of ninety-one different glass samples were used for the comparison study using the techniques mentioned. One set consisted of forty-five headlamps taken from a variety of automobiles representing a range of twenty years of manufacturing dates. A second set consisted of forty-six automotive glasses (side windows and windshields) representing casework glass from different vehicle manufacturers over several years was also characterized by RI and elemental composition analysis. The solution sample introduction techniques (external calibration and isotope dilution) provide for excellent sensitivity and precision but have the disadvantages of destroying the sample and also involve complex sample preparation. The laser ablation method was simpler, faster and produced comparable discrimination to the EC-ICP-MS and ID-ICP-MS. LA-ICP-MS can provide for an excellent alternative to solution analysis of glass in forensic casework samples. Paints and coatings are frequently encountered as trace evidence samples submitted to forensic science laboratories. A LA-ICP-MS method has been developed to complement the commonly used techniques in forensic laboratories in order to better characterize these samples for forensic purposes. Time-resolved plots of each sample can be compared to associate samples to each other or to discriminate between samples. Additionally, the concentration of lead and the ratios of other elements have been determined in various automotive paints by the reported method. A sample set of eighteen (18) survey automotive paint samples have been analyzed with the developed method in order to determine the utility of LA-ICP-MS and to compare the method to the more commonly used scanning electron microscopy (SEM) method for elemental characterization of paint layers in forensic casework.

Ultrasound enhanced activation of peroxydisulfate by activated carbon fiber for decolorization of azo dye.

PubMed

Huang, Tianyin; Zhang, Ke; Qian, Yajie; Fang, Cong; Chen, Jiabin

2018-02-20

Activated carbon fiber (ACF) has become an emerging activator for peroxydisulfate (PDS) to generate sulfate radical (SO 4 •- ). However, the relative low activation efficiency and poor contaminant mineralization limited its widespread application. Herein, ultrasound (US) was introduced to the ACF activated PDS system, and the synergistic effect of US and ACF in PDS activation and the enhancement of contaminant mineralization were investigated. The synergistic effect of US and ACF was observed in the PDS activation to decolorize orange G (OG). The decolorization efficiency increased with increasing ACF loading and US power, and PDS/OG ratio from 1 to 40. The activation energy was determined to be 24.065 kJ/mol. The radical-induced decolorization of OG took place on the surface of ACF, and both SO 4 •- and hydroxyl radical ( • OH) contributed to OG decolorization. The azo bond and naphthalene ring on OG were destructed to other aromatic intermediates and finally mineralized to CO 2 and H 2 O. The introduction of US in the ACF/PDS system significantly enhanced the mineralization of OG. The combination of US and PDS was highly efficient to activate PDS to decolorize azo dyes. Moreover, the introduction of US remarkably improved the contaminant mineralization.

A Simple Model to Rank Shellfish Farming Areas Based on the Risk of Disease Introduction and Spread.

PubMed

Thrush, M A; Pearce, F M; Gubbins, M J; Oidtmann, B C; Peeler, E J

2017-08-01

The European Union Council Directive 2006/88/EC requires that risk-based surveillance (RBS) for listed aquatic animal diseases is applied to all aquaculture production businesses. The principle behind this is the efficient use of resources directed towards high-risk farm categories, animal types and geographic areas. To achieve this requirement, fish and shellfish farms must be ranked according to their risk of disease introduction and spread. We present a method to risk rank shellfish farming areas based on the risk of disease introduction and spread and demonstrate how the approach was applied in 45 shellfish farming areas in England and Wales. Ten parameters were used to inform the risk model, which were grouped into four risk themes based on related pathways for transmission of pathogens: (i) live animal movement, (ii) transmission via water, (iii) short distance mechanical spread (birds) and (iv) long distance mechanical spread (vessels). Weights (informed by expert knowledge) were applied both to individual parameters and to risk themes for introduction and spread to reflect their relative importance. A spreadsheet model was developed to determine quantitative scores for the risk of pathogen introduction and risk of pathogen spread for each shellfish farming area. These scores were used to independently rank areas for risk of introduction and for risk of spread. Thresholds were set to establish risk categories (low, medium and high) for introduction and spread based on risk scores. Risk categories for introduction and spread for each area were combined to provide overall risk categories to inform a risk-based surveillance programme directed at the area level. Applying the combined risk category designation framework for risk of introduction and spread suggested by European Commission guidance for risk-based surveillance, 4, 10 and 31 areas were classified as high, medium and low risk, respectively. © 2016 Crown copyright.

How a New Health Intervention Affects the Health Systems? Learnings from Pentavalent Vaccine Introduction in India.

PubMed

Lahariya, Chandrakant; Paruthi, Renu; Bhattacharya, Madhulekha

2016-04-01

To summarize the findings from a Post Introduction Evaluation (PIE) of pentavalent vaccine in Tamil Nadu and Kerala state of India and to understand how the health systems could be prepared for (prior to) introducing a new intervention and how such introduction could affect the health systems (afterwards). A post introduction evaluation (PIE) of Haemophilus influenzae type b (Hib) as pentavalent (DPT + HepB + Hib) vaccine was conducted in Tamil Nadu and Kerala states of India in July-Aug 2012. The PIE was conducted as per World Health Organization PIE methods and tools specifically adapted for India. This PIE adopted a 'mixed method approach' with qualitative data focus. The planning for the introduction of pentavalent vaccine provided opportunities to strengthen various functions of the health system i.e., piloting of Open Vial Policy, strengthening surveillance system, improving Adverse Events Following Immunization (AEFI) reporting system and formation of the technical expert groups. It provided opportunity for bringing attention on the immunization programme in general as well. After the vaccine introduction, the beneficial effects were noted on stewardship (increased oversight by top level policy makers and programme managers), creating resources (investment and trainings of staff in immunization), service delivery (increased coverage with the vaccines and improved quality of services) and financing (increased financial allocation and reduced out of pocket expenditures as more people started attending public health facilities). The vaccine introduction was found to be associated with improvement in the health equity, efficiency and service utilization (effective coverage). New vaccine introduction provides opportunities (both before and after) for strengthening the health systems in setting such as India. Preparing the health system for new challenges has potential to strengthen the health systems, if done in well-coordinated and planned manner. Considering that essential steps are largely similar, these lessons could be applicable for the introduction of other new health interventions in the similar settings.

Adapting Pharmacoeconomics to Shape Efficient Health Systems en Route to UHC - Lessons from Two Continents.

PubMed

Miot, Jacqui; Thiede, Michael

2017-01-01

Background: Pharmacoeconomics is receiving increasing attention globally as a set of tools ensuring efficient use of resources in health systems, albeit with different applications depending on the contextual, cultural and development stages of each country. The factors guiding design, implementation and optimisation of pharmacoeconomics as a steering tool under the universal health coverage paradigm are explored using case studies of Germany and South Africa. Findings: German social health insurance is subject to the efficiency precept. Pharmaco-regulatory tools reflect the respective framework conditions under which they developed at particular points in time. The institutionalization and integration of pharmacoeconomics into the remit of the Institute for Quality and Efficiency in Health Care occurred only rather recently. The road has not been smooth, requiring political discourse and complex processes of negotiation. Although enshrined in the National Drug Policy, South Africa has had a more fragmented approach to medicine selection and pricing with different policies in private and public sectors. The regulatory reform for use of pharmacoeconomic tools is ongoing and will be further shaped by the introduction of National Health Insurance. Conclusion: A clear vision or framework is essential as the regulatory introduction of pharmacoeconomics is not a single event but rather a growing momentum. The path will always be subject to influences of politics, economics and market forces beyond the healthcare system so delays and modifications to pharmacoeconomic tools are to be expected. Health systems are dynamic and pharmacoeconomic reforms need to be sufficiently flexible to evolve alongside.

Groundwater Sampling at ISCO Sites: Binary Mixtures of Volatile Organic Compounds and Persulfate

EPA Science Inventory

In-situ chemical oxidation involves the introduction of a chemical oxidant into the subsurface for the purpose of transforming ground-water contaminants into less harmful byproducts. Due to oxidant persistence, ground water samples collected at hazardous waste sites may contain o...

EPA GROUND WATER ISSUE: Ground Water Sample Preservation at ISCO Sites – Recommended Guidelines

EPA Science Inventory

In-situ chemical oxidation (ISCO) involves the introduction of a chemical oxidant into the subsurface for the purpose of transforming ground water contaminants into harmless byproducts. Due to oxidant persistence, ground water samples collected at hazardous waste sites may contai...

Introduction to the Apollo collections. Part 1: Lunar igneous rocks

NASA Technical Reports Server (NTRS)

Mcgee, P. E.; Warner, J. L.; Simonds, C. H.

1977-01-01

The basic petrographic, chemical, and age data is presented for a representative suite of igneous rocks gathered during the six Apollo missions. Tables are given for 69 samples: 32 igneous rocks and 37 impactites (breccias). A description is given of 26 basalts, four plutonic rocks, and two pyroclastic samples. The textural-mineralogic name assigned each sample is included.

Extreme ultraviolet reflection efficiencies of diamond-turned aluminum, polished nickel, and evaporated gold surfaces. [for telescope mirrors

NASA Technical Reports Server (NTRS)

Malina, R. F.; Cash, W.

1978-01-01

Measured reflection efficiencies are presented for flat samples of diamond-turned aluminum, nickel, and evaporated gold surfaces fabricated by techniques suited for EUV telescopes. The aluminum samples were 6.2-cm-diameter disks of 6061-T6, the electroless nickel samples were formed by plating beryllium disks with 7.5-microns of Kanigen. Gold samples were produced by coating the aluminum and nickel samples with 5 strips of evaporated gold. Reflection efficiencies are given for grazing angles in the 5-75 degree range. The results indicate that for wavelengths over about 100 A, the gold-coated nickel samples yield highest efficiencies. For shorter wavelengths, the nickel samples yield better efficiencies. 500 A is found to be the optimal gold thickness.

Topics in Chemical Instrumentation--An Introduction to Supercritical Fluid Chromatography: Part 1: Principles and Instrumentation.

ERIC Educational Resources Information Center

Palmieri, Margo D.

1988-01-01

Identifies the properties and characteristics of supercritical fluids. Discusses the methodology for supercritical fluid chromatography including flow rate, plate height, column efficiency, viscosity, and other factors. Reviews instruments, column types, and elution conditions. Lists supercritical fluid data for 22 compounds, mostly organic. (MVL)

The Moral Imperative: The Case of the English Education System

ERIC Educational Resources Information Center

Spangenberg, Sabine; McIntosh, Bryan

2014-01-01

In England, social choice in education faces trade-offs between equity and efficiency. The scope of these trade-offs ranges from the introduction of choice to correcting "market failures" to reduce inequalities and restrict social injustices. The article analyses the English school education system and its relationship with social…

Investing in People: Access to Higher Education. Report to the Governor and 2003 Legislature.

ERIC Educational Resources Information Center

Minnesota Higher Education Services Office, St. Paul.

This report highlights services and programs of the Minnesota Higher Education Services Office that provide access to postsecondary education, noting efforts to provide services efficiently through increased use of technology and collaborations. After an introduction which discusses the Office's functions, nine sections examine: (1) "Student…

Organizational Problems of Nutrition in the Context of Modernization of Education

ERIC Educational Resources Information Center

Platonovaa, Raisa I.; Lebedeva, Uljana M.; Cherkashina, Anna G.; Ammosova, Liliya I.; Dokhunaeva, Alyona V.

2016-01-01

The realization of the project of regional educational systems' modernization was started in 2011. The main goal of the project is to achieve systemic positive changes in the school education, improving of learning conditions, increasing of openness, availability, efficiency of General education, introduction of modern educational technologies. In…

Technical efficiency gains from port reform : the potential for yardstick competition in Mexico

DOT National Transportation Integrated Search

2001-07-17

Ports are one of the key components of the logistics chain and, this is why the desire to cut costs in the sector is becoming a mainstream component of most transport policy reforms. The most common instrument relied on is the introduction of some ty...

Science Discoveries on the Net: An Integrated Approach.

ERIC Educational Resources Information Center

Fredericks, Anthony D.

This guide helps students and teachers use the Internet efficiently to find the latest information. Activities and units are divided into five categories: life science, physical science, earth science, space science, and the human body. Each unit contains an introduction, research questions, Web sites, literature resources, and activities and…

Productivity Pay: A Goal for the '80's.

ERIC Educational Resources Information Center

Stewart, John A.

The enactment of a compensation model that rewards educators' efficiency and creativity is a goal for the current decade. Both inflationary trends and the accountability movement act as motivators for the introduction of a merit pay scale. Current compensation models guarantee income regardless of effort. Through this failure to reward…

ACHP | Sustainability and Historic Preservation

Science.gov Websites

efficiency and community livability, and are protected from climate impacts. The ACHP is working to help impacts, such as storm damage, flooding, coastal erosion, drought and associated wildfires, melting be more resilient to climate impacts, including impacts to historic properties. Good introductions to

The Intermediary Guidebook: Making and Managing Community Connections for Youth.

ERIC Educational Resources Information Center

Miller, Marc; Kazis, Richard; Trippe, Steve; Eagleson, Glenn; Porter, Lois Ann

This guidebook summarizes learning on the role of intermediaries and how to build organizations that perform intermediary functions effectively and efficiently. An introduction defines intermediaries, in the context of youth-serving systems, as staffed organizations that connect schools and other youth-preparation organizations with workplaces and…

Efficiency, Equity and Autonomy.

ERIC Educational Resources Information Center

Levacic, Rosalind

This document is a chapter in "The Principles and Practice of Educational Management," which aims to provide a systematic and analytical introduction to the study of educational management. The structure of the book reflects the main substantive areas of educational leadership and management, and most of the major themes are covered in the…

Proceedings of the American Academy of Nursing Conference on Using Innovative Technology to Decrease Nursing Demand and Enhance Patient Care Delivery.

ERIC Educational Resources Information Center

Nursing Outlook, 2003

2003-01-01

Includes an introduction and 13 papers that address the following: nursing shortages; the role of technology in improving patient safety and care, simulating practice environments, and improving efficiency; and recommendations of conference participants. Many papers contain references. (JOW)

Determination of zilpaterol in sheep urine and tissues using immunochromatographic assay

USDA-ARS?s Scientific Manuscript database

Introduction: Zilpaterol is a feed additive used to increase weight gain, improve feed efficiency, and increase carcass leanness in cattle. An on-site analytical method is needed to determine zilpaterol exposure in animals to assist producer and trade groups in avoiding un-necessary animal or carca...

Agrobacterium-mediated transformation of two Serbian potato cultivars (Solanum tuberosum L. cv. Dragacevka and cv. Jelica)

USDA-ARS?s Scientific Manuscript database

An efficient protocol for Agrobacterium-mediated transformation of Serbian potato cultivars Dragacevka and Jelica, enabling the introduction of oryzacystatin genes OCI and OCII, was established. Starting with leaf explants a two-stage transformation protocol combining procedures of Webb and Wenzler...

The Principal as Change Facilitator. Bulletin 1753.

ERIC Educational Resources Information Center

Louisiana State Dept. of Education, Baton Rouge. Louisiana Dissemination Network.

This monograph surveys the literature relating to the role of the principal as change agent and the process of educational change, and reviews those characteristics that research has found to make principals more effective and efficient change agents. The introduction identifies four relevant perspectives in the research on instructional…

Introduction to Field Water-Quality Methods for the Collection of Metals - 2007 Project Summary

USGS Publications Warehouse

Allen, Monica L.

2008-01-01

The U.S. Geological Survey (USGS), Region VI of the U.S. Environmental Protection Agency (USEPA), and the Osage Nation presented three 3-day workshops, in June-August 2007, entitled ?Introduction to Field Water-Quality Methods for the Collection of Metals.? The purpose of the workshops was to provide instruction to tribes within USEPA Region VI on various USGS surface-water measurement methods and water-quality sampling protocols for the collection of surface-water samples for metals analysis. Workshop attendees included members from over 22 tribes and pueblos. USGS instructors came from Oklahoma, New Mexico, and Georgia. Workshops were held in eastern and south-central Oklahoma and New Mexico and covered many topics including presampling preparation, water-quality monitors, and sampling for metals in surface water. Attendees spent one full classroom day learning the field methods used by the USGS Water Resources Discipline and learning about the complexity of obtaining valid water-quality and quality-assurance data. Lectures included (1) a description of metal contamination sources in surface water; (2) introduction on how to select field sites, equipment, and laboratories for sample analysis; (3) collection of sediment in surface water; and (4) utilization of proper protocol and methodology for sampling metals in surface water. Attendees also were provided USGS sampling equipment for use during the field portion of the class so they had actual ?hands-on? experience to take back to their own organizations. The final 2 days of the workshop consisted of field demonstrations of current USGS water-quality sample-collection methods. The hands-on training ensured that attendees were exposed to and experienced proper sampling procedures. Attendees learned integrated-flow techniques during sample collection, field-property documentation, and discharge measurements and calculations. They also used enclosed chambers for sample processing and collected quality-assurance samples to verify their techniques. Benefits of integrated water-quality sample-collection methods are varied. Tribal environmental programs now have the ability to collect data that are comparable across watersheds. The use of consistent sample collection, manipulation, and storage techniques will provide consistent quality data that will enhance the understanding of local water resources. The improved data quality also will help the USEPA better document the condition of the region?s water. Ultimately, these workshops equipped tribes to use uniform sampling methods and to provide consistent quality data that are comparable across the region.

2016 Hans O. Mauksch Address: Are Introduction to Sociology and Social Problems Morphing into Each Other? What Syllabi Can Tell Us

ERIC Educational Resources Information Center

Lowney, Kathleen S.; Price, Anne M.; Gonzalez Guittar, Stephanie

2017-01-01

Given that so many college students take Introduction to Sociology or Social Problems or both, we wondered about the amount of content overlap in these courses. We designed a study that used content analysis of syllabi from these courses in order to measure the amount of convergence between the two classes. In our sample, nearly 70 percent of the…

Molecular identification key based on PCR/RFLP for three polychaete sibling species of the genus Marenzelleria, and the species' current distribution in the Baltic Sea

NASA Astrophysics Data System (ADS)

Blank, M.; Laine, A. O.; Jürss, K.; Bastrop, R.

2008-06-01

Studies of Marenzelleria species were often hampered by identification uncertainties when using morphological characters only. A newly developed PCR/RFLP protocol allows a more efficient discrimination of the three species Marenzelleria viridis, Marenzelleria neglecta and Marenzelleria arctia currently known for the Baltic Sea. The protocol is based on PCR amplification of two mitochondrial DNA gene segments (16S, COI) followed by digestion with restriction enzymes. As it is faster and cheaper than PCR/sequencing protocols used so far, the protocol is recommended for large-scale analyses. The markers allow an undoubted determination of species irrespective of life stage or condition of the worms in the samples. The protocol was validated on about 950 specimens sampled at more than 30 sites of the Baltic and the North Sea, and on specimens from populations of the North American east coast. Besides this test we used mitochondrial DNA sequences (16S, COI, Cytb) and starch gel electrophoresis to further investigate the distribution of the three Marenzelleria species in the Baltic Sea. The results show that M. viridis (formerly genetic type I or M. cf. wireni) occurred in the Öresund area, in the south western as well as in the eastern Baltic Sea, where it is found sympatric with M. neglecta. Allozyme electrophoresis indicated an introduction by range expansion from the North Sea. The second species, M. arctia, was only found in the northern Baltic Sea, where it sometimes occurred sympatric with M. neglecta or M. viridis. For Baltic M. arctia, the most probable way of introduction is by ship ballast water from the European Arctic. There is an urgent need for a new genetic analysis of all Marenzelleria populations of the Baltic Sea to unravel the current distribution of the three species.

Costs and financing of routine immunization: Approach and selected findings of a multi-country study (EPIC).

PubMed

Brenzel, Logan; Young, Darwin; Walker, Damian G

2015-05-07

Few detailed facility-based costing studies of routine immunization (RI) programs have been conducted in recent years, with planners, managers and donors relying on older information or data from planning tools. To fill gaps and improve quality of information, a multi-country study on costing and financing of routine immunization and new vaccines (EPIC) was conducted in Benin, Ghana, Honduras, Moldova, Uganda and Zambia. This paper provides the rationale for the launch of the EPIC study, as well as outlines methods used in a Common Approach on facility sampling, data collection, cost and financial flow estimation for both the routine program and new vaccine introduction. Costing relied on an ingredients-based approach from a government perspective. Estimating incremental economic costs of new vaccine introduction in contexts with excess capacity are highlighted. The use of more disaggregated System of Health Accounts (SHA) coding to evaluate financial flows is presented. The EPIC studies resulted in a sample of 319 primary health care facilities, with 65% of facilities in rural areas. The EPIC studies found wide variation in total and unit costs within each country, as well as between countries. Costs increased with level of scale and socio-economic status of the country. Governments are financing an increasing share of total RI financing. This study provides a wealth of high quality information on total and unit costs and financing for RI, and demonstrates the value of in-depth facility approaches. The paper discusses the lessons learned from using a standardized approach, as well as proposes further areas of methodology development. The paper discusses how results can be used for resource mobilization and allocation, improved efficiency of services at the country level, and to inform policies at the global level. Efforts at routinizing cost analysis to support sustainability efforts would be beneficial. Copyright © 2015 Elsevier Ltd. All rights reserved.

The Reusable Handheld Electrolyte and Lab Technology for Humans (rHEALTH) Sensor

NASA Technical Reports Server (NTRS)

Chan, Eugene

2015-01-01

The DNA Medicine Institute has produced a reusable microfluidic device that performs rapid, low-cost cell counts and measurements of electrolytes, proteins, and other biomarkers. The rHEALTH sensor is compact and portable, and it employs cutting-edge fluorescence detection optics, innovative microfluidics, and nanostrip reagents to perform a suite of hematology, chemistry, and biomarker assays from a single drop of blood. A handful of current portable POC devices provide generalized blood analysis, but they perform only a few tests at a time. These devices also rely on disposable components and depend on diverse detection technologies to complete routine tests-all ill-suited for space travelers on extended missions. In contrast, the rHEALTH sensor integrates sample introduction, processing, and detection with a compact, resource-conscious, and efficient design. Developed to monitor astronaut health on the International Space Station and during long-term space flight, this microscale lab analysis tool also has terrestrial applications that include POC diagnostics conducted at a patient's bedside, in a doctor's office, and in a hospital.

Mid-infrared emission and Judd-Ofelt analysis of Dy3+-doped infrared Ga-Sb-S and Ga-Sb-S-PbI2 chalcohalide glasses

NASA Astrophysics Data System (ADS)

Guo, Jixiao; Jiao, Qing; He, Xiaolong; Guo, Hansong; Tong, Jianghao; Zhang, Zhihang; Jiang, Fuchao; Wang, Guoxiang

2018-03-01

Dy3+-doped Ga-Sb-S and Ga-Sb-S-PbI2 chalcohalide glasses were prepared by traditional melt quenching method. The effect of halide PbI2 on the physical and optical properties of Dy3+ ions was investigated. The density and ionic concentration of the host sample increased with the introduction of PbI2 halides, whereas the refractive index at 1.55 μm decreased. The Judd-Ofelt parameters showed that Ω2 increased in PbI2-modified glass, whereas the Ω6 value showed the opposite tendency. Infrared emission spectrum also showed that the intensity increased with PbI2 addition, and considerable enhancement at 2.8 μm was observed in the mid-infrared region. The halide PbI2 promoted the reduction of phonon energy of the host and the improvement of the laser pump efficiency, which led to the construction of optimized infrared glass materials for optical applications.

An Introduction to Item Response Theory for Patient-Reported Outcome Measurement

PubMed Central

Nguyen, Tam H.; Han, Hae-Ra; Kim, Miyong T.

2015-01-01

The growing emphasis on patient-centered care has accelerated the demand for high-quality data from patient-reported outcome (PRO) measures. Traditionally, the development and validation of these measures has been guided by classical test theory. However, item response theory (IRT), an alternate measurement framework, offers promise for addressing practical measurement problems found in health-related research that have been difficult to solve through classical methods. This paper introduces foundational concepts in IRT, as well as commonly used models and their assumptions. Existing data on a combined sample (n = 636) of Korean American and Vietnamese American adults who responded to the High Blood Pressure Health Literacy Scale and the Patient Health Questionnaire-9 are used to exemplify typical applications of IRT. These examples illustrate how IRT can be used to improve the development, refinement, and evaluation of PRO measures. Greater use of methods based on this framework can increase the accuracy and efficiency with which PROs are measured. PMID:24403095

Improving single molecule force spectroscopy through automated real-time data collection and quantification of experimental conditions

PubMed Central

Scholl, Zackary N.; Marszalek, Piotr E.

2013-01-01

The benefits of single molecule force spectroscopy (SMFS) clearly outweigh the challenges which include small sample sizes, tedious data collection and introduction of human bias during the subjective data selection. These difficulties can be partially eliminated through automation of the experimental data collection process for atomic force microscopy (AFM). Automation can be accomplished using an algorithm that triages usable force-extension recordings quickly with positive and negative selection. We implemented an algorithm based on the windowed fast Fourier transform of force-extension traces that identifies peaks using force-extension regimes to correctly identify usable recordings from proteins composed of repeated domains. This algorithm excels as a real-time diagnostic because it involves <30 ms computational time, has high sensitivity and specificity, and efficiently detects weak unfolding events. We used the statistics provided by the automated procedure to clearly demonstrate the properties of molecular adhesion and how these properties change with differences in the cantilever tip and protein functional groups and protein age. PMID:24001740

An introduction to item response theory for patient-reported outcome measurement.

PubMed

Nguyen, Tam H; Han, Hae-Ra; Kim, Miyong T; Chan, Kitty S

2014-01-01

The growing emphasis on patient-centered care has accelerated the demand for high-quality data from patient-reported outcome (PRO) measures. Traditionally, the development and validation of these measures has been guided by classical test theory. However, item response theory (IRT), an alternate measurement framework, offers promise for addressing practical measurement problems found in health-related research that have been difficult to solve through classical methods. This paper introduces foundational concepts in IRT, as well as commonly used models and their assumptions. Existing data on a combined sample (n = 636) of Korean American and Vietnamese American adults who responded to the High Blood Pressure Health Literacy Scale and the Patient Health Questionnaire-9 are used to exemplify typical applications of IRT. These examples illustrate how IRT can be used to improve the development, refinement, and evaluation of PRO measures. Greater use of methods based on this framework can increase the accuracy and efficiency with which PROs are measured.

Combinatorial materials approach to accelerate materials discovery for transportation (Conference Presentation)

NASA Astrophysics Data System (ADS)

Tong, Wei

2017-04-01

Combinatorial material research offers fast and efficient solutions to identify promising and advanced materials. It has revolutionized the pharmaceutical industry and now is being applied to accelerate the discovery of other new compounds, e.g. superconductors, luminescent materials, catalysts etc. Differing from the traditional trial-and-error process, this approach allows for the synthesis of a large number of compositionally diverse compounds by varying the combinations of the components and adjusting the ratios. It largely reduces the cost of single-sample synthesis/characterization, along with the turnaround time in the material discovery process, therefore, could dramatically change the existing paradigm for discovering and commercializing new materials. This talk outlines the use of combinatorial materials approach in the material discovery in transportation sector. It covers the general introduction to the combinatorial material concept, state of art for its application in energy-related research. At the end, LBNL capabilities in combinatorial materials synthesis and high throughput characterization that are applicable for material discovery research will be highlighted.

The selective catalytic reduction of NO with NH3 over a novel Ce-Sn-Ti mixed oxides catalyst: Promotional effect of SnO2

NASA Astrophysics Data System (ADS)

Yu, Ming'e.; Li, Caiting; Zeng, Guangming; Zhou, Yang; Zhang, Xunan; Xie, Yin'e.

2015-07-01

A series of novel catalysts (CexSny) for the selective catalytic reduction of NO by NH3 were prepared by the inverse co-precipitation method. The aim of this novel design was to improve the NO removal efficiency of CeTi by the introduction of SnO2. It was found that the Ce-Sn-Ti catalyst was much more active than Ce-Ti and the best Ce:Sn molar ratio was 2:1. Ce2Sn1 possessed a satisfied NO removal efficiency at low temperature (160-280 °C), while over 90% NO removal efficiency maintained in the temperature range of 280-400 °C at the gas hourly space velocity (GHSV) of 50,000 h-1. Besides, Ce2Sn1 kept a stable NO removal efficiency within a wide range of GHSV and a long period of reacting time. Meanwhile, Ce2Sn1 exhibited remarkable resistance to both respectively and simultaneously H2O and SO2 poisoning due to the introduction of SnO2. The promotional effect of SnO2 was studied by N2 adsorption-desorption, X-ray diffraction (XRD), Raman spectra, X-ray photoelectron spectroscopy (XPS) and H2 temperature programmed reduction (H2-TPR) for detail information. The characterization results revealed that the excellent catalytic performance of Ce2Sn1 was associated with the higher specific surface area, larger pore volume and poorer crystallization. Besides, the introduction of SnO2 could result in not only greater conversion of Ce4+ to Ce3+ but also the increase amount of chemisorbed oxygen, which are beneficial to improve the SCR activity. More importantly, a novel peak appearing at lower temperatures through the new redox equilibrium of 2Ce4+ + Sn2+ ↔ 2Ce3+ + Sn4+ and higher total H2 consumption can be obtained by the addition of SnO2. Finally, the possible reaction mechanism of the selective catalytic reduction over Ce2Sn1 was also proposed.

Contrasting introduction scenarios among continents in the worldwide invasion of the banana fungal pathogen Mycosphaerella fijiensis.

PubMed

Robert, S; Ravigne, V; Zapater, M-F; Abadie, C; Carlier, J

2012-03-01

Reconstructing and characterizing introduction routes is a key step towards understanding the ecological and evolutionary factors underlying successful invasions and disease emergence. Here, we aimed to decipher scenarios of introduction and stochastic demographic events associated with the global spread of an emerging disease of bananas caused by the destructive fungal pathogen Mycosphaerella fijiensis. We analysed the worldwide population structure of this fungus using 21 microsatellites and 8 sequence-based markers on 735 individuals from 37 countries. Our analyses designated South-East Asia as the source of the global invasion and supported the location of the centre of origin of M. fijiensis within this area. We confirmed the occurrence of bottlenecks upon introduction into other continents followed by widespread founder events within continents. Furthermore, this study suggested contrasting introduction scenarios of the pathogen between the African and American continents. While potential signatures of admixture resulting from multiple introductions were detected in America, all the African samples examined seem to descend from a single successful founder event. In combination with historical information, our study reveals an original and unprecedented global scenario of invasion for this recently emerging disease caused by a wind-dispersed pathogen. © 2012 Blackwell Publishing Ltd.

THE NATIONAL CHILDREN'S STUDY: BEGINNING THE IMPLEMENTATION OF A NATIONAL-PROBABILITY SAMPLE

EPA Science Inventory

Introduction: The National Children's Study (NCS) is a longitudinal cohort study that will follow a sample of approximately 100,000 children born in the United States from before birth until 21 years of age. The NCS will investigate the separate and combined effects of environmen...

Relationship between Sociometric Type and Self-Attributions for Academic Failure in a Spanish Sample from Secondary Education

ERIC Educational Resources Information Center

Inglés, Cándido J.; Aparisi, D.; Delgado, B.; Granados, L.; García-Fernández, José M.

2017-01-01

Introduction: The aim of this study was to analyze the relationship between sociometric types, behavioral categories and self-attributions for academic failure ("Ability", "Effort" or "External Causes") in "Reading", "Mathematics" and "General". Method: The total sample was composed of…

Estimating Aquatic Insect Populations. Introduction to Sampling.

ERIC Educational Resources Information Center

Chihuahuan Desert Research Inst., Alpine, TX.

This booklet introduces high school and junior high school students to the major groups of aquatic insects and to population sampling techniques. Chapter 1 consists of a short field guide which can be used to identify five separate orders of aquatic insects: odonata (dragonflies and damselflies); ephemeroptera (mayflies); diptera (true flies);…

SNRB{trademark} air toxics monitoring. Final report

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

Not Available

1994-01-01

Babcock & Wilcox (B&W) is currently conducting a project under the DOE`s Clean Coal Technology (CCT II) Program to demonstrate its SO{sub x}NO{sub x}-Rox Box{trademark} (SNRB{trademark}) process in a 5 MWe Field Demonstration Unit at Ohio Edison`s R. E. Burger Plant near Shadyside, Ohio. The objective of the SNRB{trademark} Air Toxics Monitoring Project was to provide data on SNRB{trademark} air toxics emissions control performance to B&W and to add to the DOE/EPRI/EPA data base by quantifying the flow rates of selected hazardous substances (or air toxics) in all of the major input and output streams of the SNRB{trademark} process asmore » well as the power plant. Work under the project included the collection and analysis of representative samples of all major input and output streams of the SNRB{trademark} demonstration unit and the power plant, and the subsequent laboratory analysis of these samples to determine the partitioning of the hazardous substances between the various process streams. Material balances for selected air toxics were subsequently calculated around the SNRB{trademark} and host boiler systems, including the removal efficiencies across each of the major air pollution control devices. This report presents results of the SNRB{trademark} Air Toxics Monitoring Project. In addition to the Introduction, a brief description of the test site, including the Boiler No. 8 and the SNRB{trademark} process, is included in Section H. The concentrations of air toxic emissions are presented in Section II according to compound class. Material balances are included in Section IV for three major systems: boiler, electrostatic precipitator, and SNRB{trademark}. Emission factors and removal efficiencies are also presented according to compound class in Sections V and VI, respectively. A data evaluation is provided in Section VII.« less

[Recent advances and applications of capillary electrochromatography and pressurized capillary electrochromatography].

PubMed

Wu, Yi; Zhang, Xiaohui; Wei, Juan; Xue, Yunyun; Bahatibieke, Marjan; Wang, Yan; Yan, Chao

2009-09-01

Capillary electrochromatography (CEC), in which electroosmotic flow (EOF) created from the electrical double layer is made to act as a pump to drive the mobile phase in a capillary column packed with micro-particulates or coated with stationary phase. Both neutral and charged species can be resolved by CEC. It has been demonstrated that the efficiency of a separation obtained by electroosmotic propulsion is superior to that obtained by pressure-driven flow (as is the case in HPLC). CEC combines the best features of CE and versatile selectivity and large sample capacity of HPLC, promising high efficiency, high resolution, high selectivity and high peak capacity. However, in practice, when CEC is used without pressure, often used on a commercial CE instrument, there are problems and difficulties associated with bubbles formation and column dry-out. These difficulties can be overcome by a pressurized CEC (pCEC) system, in which a supplementary pressure is applied to the column in addition to the EOF. In such a system, a pressure can be applied to the capillary column to suppress bubbles formation. Quantitative sample introduction in pCEC can be easily achieved through a rotary-type injector. Most importantly, it is amenable for a solvent gradient mode, similar to that in HPLC, by programming the composition of mobile phase. The article brings a comprehensive survey of recent development of CEC and pCEC, including the development of instrumentation, capillary columns and stationary phase as well as CEC and pCEC applications in life science, biotechnology, pharmaceutical analysis, food safety and environmental security. Prospects for CEC and pCEC development and application are also discussed.

A new V-doped Bi2(O,S)3 oxysulfide catalyst for highly efficient catalytic reduction of 2-nitroaniline and organic dyes.

PubMed

Abay, Angaw Kelemework; Kuo, Dong-Hau; Chen, Xiaoyun; Saragih, Albert Daniel

2017-12-01

A new type of convenient, and environmentally friendly, Vanadium (V)-doped Bi 2 (O,S) 3 oxysulfide catalyst with different V contents was successfully synthesized via a simple and facile method. The obtained V-doped Bi 2 (O,S) 3 solid solution catalysts were fully characterized by conventional methods. The catalytic performance of the samples was tested by using the reduction of 2-nitroaniline (2-NA) in aqueous solution. The reduction/decolorization of methylene blue (MB) and rhodamine B (RhB) was also chosen to evaluate the universality of catalysts. It was observed that the introduction of V can improve the catalytic performance, and 20%V-Bi 2 (O,S) 3 was found to be the optimal V doping concentration for the reduction of 2-NA, MB, and RhB dyes. For comparative purposes, a related V-free Bi 2 (O, S) 3 oxysulfide material was synthesized and tested as the catalyst. The superior activity of V-doped Bi 2 (O,S) 3 over pure Bi 2 (O,S) 3 was ascribed mainly to an increase in active sites of the material and also due to the presence of synergistic effects. The presence of V 5+ as found from XPS analysis may interact with Bi atoms and enhancing the catalytic activity of the sample. In the catalytic reduction of 2-NA, MB and RhB, the obtained V-doped Bi 2 (O,S) 3 oxysulfide catalyst exhibited excellent catalytic activity as compared with other reported catalysts. Furthermore this highly efficient, low-cost and easily reusable V-doped Bi 2 (O,S) 3 catalyst is anticipated to be of great potential in catalysis in the future. Copyright © 2017 Elsevier Ltd. All rights reserved.

The impact of New Public Management on efficiency: an analysis of Madrid's hospitals.

PubMed

Alonso, José M; Clifton, Judith; Díaz-Fuentes, Daniel

2015-03-01

Madrid has recently become the site of one of the most controversial cases of public healthcare reform in the European Union. Despite the fact that the introduction of New Public Management (NPM) into Madrid hospitals has been vigorous, little scholarship has been done to test whether NPM actually led to technical efficiency. This paper is one of the first attempts to do so. We deploy a bootstrapped data envelopment analysis to compare efficiency scores in traditionally managed hospitals and those operating with new management formulas. We do not find evidence that NPM hospitals are more efficient than traditionally managed ones. Moreover, our results suggest that what actually matters may be the management itself, rather than the management model. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

ZnO/ZnSxSe1-x core/shell nanowire arrays as photoelectrodes with efficient visible light absorption

NASA Astrophysics Data System (ADS)

Wang, Zhenxing; Zhan, Xueying; Wang, Yajun; Safdar, Muhammad; Niu, Mutong; Zhang, Jinping; Huang, Ying; He, Jun

2012-08-01

ZnO/ZnSxSe1-x core/shell nanowires have been synthesized on n+-type silicon substrate via a two-step chemical vapor deposition method. Transmission electron microscopy reveals that ZnSxSe1-x can be deposited on the entire surface of ZnO nanowire, forming coaxial heterojunction along ZnO nanowire with very smooth shell surface and high shell thickness uniformity. The photoelectrode after deposition of the ternary alloy shell significantly improves visible light absorption efficiency. Electrochemical impedance spectroscopy results explicitly indicate that the introduction of ZnSxSe1-x shell to ZnO nanowires effectively improves the photogenerated charge separation process. Our finding opens up an efficient means for achieving high efficient energy conversion devices.

Development of a sufficient and effective procedure for transformation of an oleaginous yeast, Rhodosporidium toruloides DMKU3-TK16.

PubMed

Tsai, Yung-Yu; Ohashi, Takao; Kanazawa, Takenori; Polburee, Pirapan; Misaki, Ryo; Limtong, Savitree; Fujiyama, Kazuhito

2017-05-01

Rhodosporidium toruloides DMKU3-TK16 (TK16), a basidiomycetous yeast isolated in Thailand, can produce a large amount of oil corresponding to approximately 70 % of its dry cell weight. However, lack of a sufficient and efficient transformation method makes further genetic manipulation of this organism difficult. We here developed a new transformation system for R. toruloides using a lithium acetate method with the Sh ble gene as a selective marker under the control of the R. toruloides ATCC 10657 GPD1 promoter. A linear DNA fragment containing the Sh ble gene expression cassette was integrated into the genome, and its integration was confirmed by colony PCR and Southern blot. Then, we further optimized the parameters affecting the transformation efficiency, such as the amount of linear DNA, the growth phase, the incubation time in the transformation mixture, the heat shock treatment temperature, the addition of DMSO and carrier DNA, and the recovery incubation time. With the developed method, the transformation efficiency of approximately 25 transformants/μg DNA was achieved. Compared with the initial trial, transformation efficiency was enhanced 417-fold. We further demonstrated the heterologous production of EGFP in TK16 by microscopic observation and immunoblot analysis, and use the technique to disrupt the endogenous URA3 gene. The newly developed method is thus simple and time saving, making it useful for efficient introduction of an exogenous gene into R. toruloides strains. Accordingly, this new practical approach should facilitate the molecular manipulation, such as target gene introduction and deletion, of TK16 and other R. toruloides strains as a major source of biodiesel.

Unified Model for the Overall Efficiency of Inlets Sampling from Horizontal Aerosol Flows

NASA Astrophysics Data System (ADS)

Hangal, Sunil Pralhad

When sampling aerosols from ambient or industrial air environments, the sampled aerosol must be representative of the aerosol in the free stream. The changes that occur during sampling must be assessed quantitatively so that sampling errors can be compensated for. In this study, unified models have been developed for the overall efficiency of tubular sharp-edged inlets sampling from horizontal aerosol flows oriented at 0 to 90^circ relative to the wind direction in the vertical (pitch) and horizontal plane(yaw). In the unified model, based on experimental data, the aspiration efficiency is represented by a single equation with different inertial parameters at 0 to 60^ circ and 45 to 90^circ . Tnt transmission efficiency is separated into two components: one due to gravitational settling in the boundary layer and the other due to impaction. The gravitational settling component is determined by extending a previously developed isoaxial sampling model to nonisoaxial sampling. The impaction component is determined by a new model that quantifies the particle losses caused by wall impaction. The model also quantifies the additional particle losses resulting from turbulent motion in the vena contracta which is formed in the inlet when the inlet velocity is higher than the wind velocity. When sampling aerosols in ambient or industrial environments with an inlet, small changes in wind direction or physical constraints in positioning the inlet in the system necessitates the assessment of sampling efficiency in both the vertical and horizontal plane. The overall sampling efficiency of tubular inlets has been experimentally investigated in yaw and pitch orientations at 0 to 20 ^circ from horizontal aerosol flows using a wind tunnel facility. The model for overall sampling efficiency has been extended to include both yaw and pitch sampling based on the new data. In this model, the difference between yaw and pitch is expressed by the effect of gravity on the impaction process inside the inlet described by a newly developed gravity effect angle. At yaw, the gravity effect angle on the wall impaction process does not change with sampling angle. At pitch, the gravity effect on the impaction process results in particle loss increase for upward and decrease for downward sampling. Using the unified model, graphical representations have been developed for sampling at small angles. These can be used in the field to determine the overall sampling efficiency of inlets at several operating conditions and the operating conditions that result in an acceptable sampling error. Pitch and diameter factors have been introduced for relating the efficiency values over a wide range of conditions to those of a reference condition. The pitch factor determines the overall sampling efficiency at pitch from yaw values, and the diameter factor determines the overall sampling efficiency at different inlet diameters.

A spatiotemporal model to assess the introduction risk of African horse sickness by import of animals and vectors in France.

PubMed

Faverjon, C; Leblond, A; Hendrikx, P; Balenghien, T; de Vos, C J; Fischer, E A J; de Koeijer, A A

2015-06-04

African horse sickness (AHS) is a major, Culicoides-borne viral disease in equines whose introduction into Europe could have dramatic consequences. The disease is considered to be endemic in sub-Saharan Africa. Recent introductions of other Culicoides-borne viruses (bluetongue and Schmallenberg) into northern Europe have highlighted the risk that AHS may arrive in Europe as well. The aim of our study was to provide a spatiotemporal quantitative risk model of AHS introduction into France. The study focused on two pathways of introduction: the arrival of an infectious host (PW-host) and the arrival of an infectious Culicoides midge via the livestock trade (PW-vector). The risk of introduction was calculated by determining the probability of an infectious animal or vector entering the country and the probability of the virus then becoming established: i.e., the virus's arrival in France resulting in at least one local equine host being infected by one local vector. This risk was assessed using data from three consecutive years (2010 to 2012) for 22 regions in France. The results of the model indicate that the annual risk of AHS being introduced to France is very low but that major spatiotemporal differences exist. For both introduction pathways, risk is higher from July to October and peaks in July. In general, regions with warmer climates are more at risk, as are colder regions with larger equine populations; however, regional variation in animal importation patterns (number and species) also play a major role in determining risk. Despite the low probability that AHSV is present in the EU, intra-EU trade of equines contributes most to the risk of AHSV introduction to France because it involves a large number of horse movements. It is important to address spatiotemporal differences when assessing the risk of ASH introduction and thus also when implementing efficient surveillance efforts. The methods and results of this study may help develop surveillance techniques and other risk reduction measures that will prevent the introduction of AHS or minimize AHS' potential impact once introduced, both in France and the rest of Europe.

Microplasmas for chemical analysis: analytical tools or research toys?

NASA Astrophysics Data System (ADS)

Karanassios, Vassili

2004-07-01

An overview of the activities of the research groups that have been involved in fabrication, development and characterization of microplasmas for chemical analysis over the last few years is presented. Microplasmas covered include: miniature inductively coupled plasmas (ICPs); capacitively coupled plasmas (CCPs); microwave-induced plasmas (MIPs); a dielectric barrier discharge (DBD); microhollow cathode discharge (MCHD) or microstructure electrode (MSE) discharges, other microglow discharges (such as those formed between "liquid" electrodes); microplasmas formed in micrometer-diameter capillary tubes for gas chromatography (GC) or high-performance liquid chromatography (HPLC) applications, and a stabilized capacitive plasma (SCP) for GC applications. Sample introduction into microplasmas, in particular, into a microplasma device (MPD), battery operation of a MPD and of a mini- in-torch vaporization (ITV) microsample introduction system for MPDs, and questions of microplasma portability for use on site (e.g., in the field) are also briefly addressed using examples of current research. To emphasize the significance of sample introduction into microplasmas, some previously unpublished results from the author's laboratory have also been included. And an overall assessment of the state-of-the-art of analytical microplasma research is provided.

Formulation strategies for optimizing the morphology of polymeric bulk heterojunction organic solar cells: a brief review

NASA Astrophysics Data System (ADS)

Vongsaysy, Uyxing; Bassani, Dario M.; Servant, Laurent; Pavageau, Bertrand; Wantz, Guillaume; Aziz, Hany

2014-01-01

Polymeric bulk heterojunction (BHJ) organic solar cells represent one of the most promising technologies for renewable energy with a low fabrication cost. Control over BHJ morphology is one of the key factors in obtaining high-efficiency devices. This review focuses on formulation strategies for optimizing the BHJ morphology. We address how solvent choice and the introduction of processing additives affect the morphology. We also review a number of recent studies concerning prediction methods that utilize the Hansen solubility parameters to develop efficient solvent systems.

Pharmacophore mapping in the laulimalide series: total synthesis of a vinylogue for a late-stage metathesis diversification strategy.

PubMed

Wender, Paul A; Hilinski, Michael K; Skaanderup, Philip R; Soldermann, Nicolas G; Mooberry, Susan L

2006-08-31

An efficient synthesis of the macrocyclic core of laulimalide with a pendant vinyl group at C20 is described, allowing for late-stage introduction of various side chains through a selective and efficient cross metathesis diversification step. Representative analogues reported herein are the first to contain modifications to only the side chain dihydropyran of laulimalide and des-epoxy laulimalide. This step-economical strategy enables the rapid synthesis of new analogues using alkenes as an inexpensive, abundantly available diversification feedstock.

Studies on transport phenomena in electrothermal vaporization sample introduction applied to inductively coupled plasma for optical emission and mass spectrometry

NASA Astrophysics Data System (ADS)

Kántor, T.; Maestre, S.; de Loos-Vollebregt, M. T. C.

2005-10-01

In the present work electrothermal vaporization (ETV) was used in both inductively coupled plasma mass spectrometry (ICP-MS) and optical emission spectrometry (OES) for sample introduction of solution samples. The effect of (Pd + Mg)-nitrate modifier and CaCl 2 matrix/modifier of variable amounts were studied on ETV-ICP-MS signals of Cr, Cu, Fe, Mn and Pb and on ETV-ICP-OES signals of Ag, Cd, Co, Cu, Fe, Ga, Mn and Zn. With the use of matrix-free standard solutions the analytical curves were bent to the signal axes (as expected from earlier studies), which was observed in the 20-800 pg mass range by ICP-MS and in the 1-50 ng mass range by ICP-OES detection. The degree of curvature was, however, different with the use of single element and multi-element standards. When applying the noted chemical modifiers (aerosol carriers) in microgram amounts, linear analytical curves were found in the nearly two orders of magnitude mass ranges. Changes of the CaCl 2 matrix concentration (loaded amount of 2-10 μg Ca) resulted in less than 5% changes in MS signals of 5 elements (each below 1 ng) and OES signals of 22 analytes (each below 15 ng). Exceptions were Pb (ICP-MS) and Cd (ICP-OES), where the sensitivity increase by Pd + Mg modifier was much larger compared to other elements studied. The general conclusions suggest that quantitative analysis with the use of ETV sample introduction requires matrix matching or matrix replacement by appropriate chemical modifier to the specific concentration ranges of analytes. This is a similar requirement to that claimed also by the most commonly used pneumatic nebulization of solutions, if samples with high matrix concentration are concerned.

Trace elements determination in seawater by ICP-MS with on-line pre-concentration on a Chelex-100 column using a ‘standard’ instrument setup.

PubMed Central

Søndergaard, Jens; Asmund, Gert; Larsen, Martin M.

2015-01-01

Trace element determination in seawater is analytically challenging due to the typically very low concentrations of the trace elements and the potential interference of the salt matrix. A common way to address the challenge is to pre-concentrate the trace elements on a chelating resin, then rinse the matrix elements from the resin and subsequently elute and detect the trace elements using inductively coupled plasma mass spectrometry (ICP-MS). This technique typically involves time-consuming pre-treatment of the samples for ‘off-line’ analyses or complicated sample introduction systems involving several pumps and valves for ‘on-line’ analyses. As an alternative, the following method offers a simple method for ‘on-line’ analyses of seawater by ICP-MS. As opposed to previous methods, excess seawater was pumped through the nebulizer of the ICP-MS during the pre-concentration step but the gas flow was adjusted so that the seawater was pumped out as waste without being sprayed into the instrument. Advantages of the method include: • Simple and convenient analyses of seawater requiring no changes to the ‘standard’ sample introduction system except from a resin-filled micro-column connected to the sample tube. The ‘standard’ sample introduction system refers to that used for routine digest-solution analyses of biota and sediment by ICP-MS using only one peristaltic pump; and • Accurate determination of the elements V, Mn, Co, Ni, Cu, Zn, Cd and Pb in a range of different seawater matrices verified by participation in 6 successive rounds of the international laboratory intercalibration program QUASIMEME. PMID:26258050

Efficient electroporation of DNA and protein into confluent and differentiated epithelial cells in culture.

PubMed

Deora, Ami A; Diaz, Fernando; Schreiner, Ryan; Rodriguez-Boulan, Enrique

2007-10-01

Electroporation-mediated delivery of molecules is a procedure widely used for transfecting complementary DNA in bacteria, mammalian and plant cells. This technique has proven very efficient for the introduction of macromolecules into cells in suspension culture and even into cells in their native tissue environment, e.g. retina and embryonic tissues. However, in spite of several attempts to date, there are no well-established procedures to electroporate polarized epithelial cells adhering to a tissue culture substrate (glass, plastic or filter). We report here the development of a simple procedure that uses available commercial equipment and works efficiently and reproducibly for a variety of epithelial cell lines in culture.

Y2O3 modified TiO2 nanosheets enhanced the photocatalytic removal of 4-chlorophenol and Cr (VI) in sun light

NASA Astrophysics Data System (ADS)

Zhao, Xiaona; Wu, Pei; Liu, Min; Lu, Dingze; Ming, Junlan; Li, Chunhe; Ding, Junqian; Yan, Qiuyang; Fang, Pengfei

2017-07-01

Y2O3 modified TiO2 nanosheets (Y2O3@TNSs), capable of exhibiting sun light, were synthesized through one pot/hydrothermal method using Y (NO3)3 as precursor. Multiple techniques were applied to investigate the structures, morphologies, optical and electronic properties and photocatalytic performance of the as-prepared samples. The Y2O3@TNSs, with thickness of approximately 3-4 nm, large surface area of 240-350 m2/g, were full of Y2O3 nanoparticles highly dispersed on the surface. The introduction of Y2O3 influenced the crystallinity and the structure evolution of TNSs, besides, improved the light absorption ability. The surface photo-current and fluorescence spectral studies revealed that the photo-generated charge carrier separation efficiency could be improved by an appropriate modification. The degradation activity of this sun-light-induced photocatalytic has enhanced apparently on 4-Chlorophenol and K2Cr2O7 solution, the degradation efficiency of 4-Chlorophenol reached 5.69 times than that of P25, and the maximum TOC removal obtained after 120 min was 67.6%, indicating that most organic compounds were released from the solution. The enhancement in the photocatalytic activity was attributed to the synergetic effect of the Y2O3 and TNSs, which led to a fast separation and slow recombination of photo-induced electron-hole pairs. Consequently, the high efficiency in the experiments showed a promising application of the catalyst in the oxidation or reduction degradation of organic pollutants.

Rapid Screening of Carboxylic Acids from Waste and Surface Waters by ESI-MS/MS Using Barium Ion Chemistry and On-Line Membrane Sampling.

PubMed

Duncan, Kyle D; Volmer, Dietrich A; Gill, Chris G; Krogh, Erik T

2016-03-01

Negative ion tandem mass spectrometric analysis of aliphatic carboxylic acids often yields only non-diagnostic ([M - H](-)) ions with limited selective fragmentation. However, carboxylates cationized with Ba(2+) have demonstrated efficient dissociation in positive ion mode, providing structurally diagnostic product ions. We report the application of barium adducts followed by collision induced dissociation (CID), to improve selectivity for rapid screening of carboxylic acids in complex aqueous samples. The quantitative MS/MS method presented utilizes common product ions of [M - H + Ba](+) precursor ions. The mechanism of product ion formation is investigated using isotopically labeled standards and a series of structurally related carboxylic acids. The results suggest that hydrogen atoms in the β and γ positions yield common product ions ([BaH](+) and [BaOH](+)). Furthermore, the diagnostic product ion at m/z 196 serves as a qualifying ion for carboxylate species. This methodology has been successfully used in conjunction with condensed phase membrane introduction mass spectrometry (CP-MIMS), with barium acetate added directly to the methanol acceptor phase. The combination enables rapid screening of carboxylic acids directly from acidified water samples (wastewater effluent, spiked natural waters) using a capillary hollow fiber PDMS membrane immersion probe. We have applied this technique for the direct analysis of complex naphthenic acid mixtures spiked into natural surface waters using CP-MIMS. Selectivity at the ionization and tandem mass spectrometry level eliminate isobaric interferences from hydroxylated species present within the samples, which have been observed in negative electrospray ionization.

Optimising the Number of Replicate- Versus Standard Measurements for Carbonate Clumped Isotope Thermometry

NASA Astrophysics Data System (ADS)

Kocken, I.; Ziegler, M.

2017-12-01

Clumped isotope measurements on carbonates are a quickly developing and promising palaeothermometry proxy1-3. Developments in the field have brought down the necessary sample amount and improved the precision and accuracy of the measurements. The developments have included inter-laboratory comparison and the introduction of an absolute reference frame4, determination of acid fractionation effects5, correction for the pressure baseline6, as well as improved temperature calibrations2, and most recently new approaches to improve efficiency in terms of sample gas usage7. However, a large-scale application of clumped isotope thermometry is still hampered by required large sample amounts, but also the time-consuming analysis. In general, a lot of time is goes into the measurement of standards. Here we present a study on the optimal ratio between standard- and sample measurements using the Kiel Carbonate Device method. We also consider the optimal initial signal intensity. We analyse ETH-standard measurements from several months to determine the measurement regime with the highest precision and optimised measurement time management.References 1. Eiler, J. M. Earth Planet. Sci. Lett. 262, 309-327 (2007).2. Kelson, J. R., et al. Geochim. Cosmochim. Acta 197, 104-131 (2017).3. Kele, S. et al. Geochim. Cosmochim. Acta 168, 172-192 (2015).4. Dennis, K. J. et al. Geochim. Cosmochim. Acta 75, 7117-7131 (2011).5. Müller, I. A. et al. Chem. Geol. 449, 1-14 (2017).6. Meckler, A. N. et al. Rapid Commun. Mass Spectrom. 28, 1705-1715 (2014).7. Hu, B. et al. Rapid Commun. Mass Spectrom. 28, 1413-1425 (2014).

Room temperature ionic liquid-based dispersive liquid phase microextraction for the separation/preconcentration of trace Cd(2+) as 1-(2-pyridylazo)-2-naphthol (PAN) complex from environmental and biological samples and determined by FAAS.

PubMed

Khan, Sumaira; Soylak, Mustafa; Kazi, Tasneem Gul

2013-12-01

The current work develops a new green methodology for the separation/preconcentration of cadmium ions (Cd(2+)) using room temperature ionic liquid-dispersive liquid phase microextraction (RTIL-DLME) prior to analysis by flame atomic absorption spectrometry with microsample introduction system. Room temperature ionic liquids (RTIL) are considered "Green Solvents" for their thermally stable and non-volatile properties, here 1-butyl-3-methylimidazolium hexafluorophosphate [C4mim][PF6] was used as an extractant. The preconcentration of Cd(2+) in different waters and acid digested scalp hair samples were complexed with 1-(2-pyridylazo)-2-naphthol and extracted into the fine drops of RTILs. Some significant factors influencing the extraction efficiency of Cd(2+) and its subsequent determination, including pH, amount of ligand, volume of RTIL, dispersant solvent, sample volume, temperature, and incubation time were investigated in detail. The limit of detection and the enhancement factor under the optimal conditions were 0.05 μg/L and 50, respectively. The relative standard deviation of 100 μg/L Cd(2+) was 4.3 %. The validity of the proposed method was checked by determining Cd(2+) in certified reference material (TM-25.3 fortified water). The sufficient recovery (>98 %) of Cd(2+) with the certified value. The mean concentrations of Cd in lake water 13.2, waste water 15.7 and hair sample 16.8 μg/L, respectively and the developed method was applied satisfactorily to the preconcentration and determination of Cd(2+) in real samples.

The World Coal Quality Inventory: South America

USGS Publications Warehouse

Karlsen, Alex W.; Tewalt, Susan J.; Bragg, Linda J.; Finkelman, Robert B.

2006-01-01

Executive Summary-Introduction: The concepts of a global environment and economy are strongly and irrevocably linked to global energy issues. Worldwide coal production and international coal trade are projected to increase during the next several decades in an international energy mix that is still strongly dependent on fossil fuels. Therefore, worldwide coal use will play an increasingly visible role in global environmental, economic, and energy forums. Policy makers require information on coal, including coal quality data, to make informed decisions regarding domestic coal resource allocation, import needs and export opportunities, foreign policy objectives, technology transfer policies, foreign investment prospects, environmental and health assessments, and byproduct use and disposal issues. The development of a worldwide, reliable, coal quality database would help ensure the most economically and environmentally efficient global use of coal. The U.S. Geological Survey (USGS), in cooperation with many agencies and scientists from the world's coal producing countries, originally undertook a project to obtain representative samples of coal from most of the world's producing coal provinces during a limited period of time (roughly 1998-2005), which is called the World Coal Quality Inventory (WoCQI). The multitude of producing coal mines, coal occurrences, or limited accessibility to sites in some countries can preclude collecting more than a single sample from a mine. In some areas, a single sample may represent an entire coal mining region or basin. Despite these limitations in sampling and uneven distribution of sample collection, the analytical results can still provide a general overview of world coal quality. The USGS intends to present the WoCQI data in reports and, when possible, in Geographic Information System (GIS) products that cover important coal bearing and producing regions.

Determination of Rare Earth Elements in multi-year high-resolution Arctic aerosol record by double focusing Inductively Coupled Plasma Mass Spectrometry with desolvation nebulizer inlet system.

PubMed

Giardi, Fabio; Traversi, Rita; Becagli, Silvia; Severi, Mirko; Caiazzo, Laura; Ancillotti, Claudia; Udisti, Roberto

2018-02-01

An inductively coupled plasma sector field mass spectrometer (ICP-SFMS) was used to develop an analytical method for the fast determination of Na, Al, Sc, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, As, Y, Mo, Cd, Ba, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and Pb in Arctic size-segregated aerosol samples (PM 10 ), after microwave acidic digestion. The ICP-SFMS was coupled with a microflow nebulizer and a desolvation system for the sample introduction, which reduced the isobaric interferences due to oxides and the required volume of sample solutions, compared to the usual nebulization chamber methods. With its very low limit of detection, and taking into account the level of blanks, this method allowed the quantification of many metals in very low concentration. Particular attention was given to Rare Earth Elements (REEs - La to Lu). The efficiency in the extraction of REEs was proved to be acceptable, with recoveries over 83% obtained with a Certified Reference Material (AMiS 0356). The analytical method was then applied to particulate matter samples, collected at ground level in Ny Ålesund (Svalbard Islands, Norway), during spring and summer, from 2010 to 2015, with daily resolution and using a low-volume device. Thus, for the first time, a large atmospheric concentrations dataset of metals in Arctic particulate matter at high temporal resolution is presented. On the basis of differences in LREE/HREE ratio and Ce and Eu anomalies in spring and summer samples, basic information to distinguish local and long-range transported dust were achieved. Copyright © 2017 Elsevier B.V. All rights reserved.

Automated CD-SEM recipe creation technology for mass production using CAD data

NASA Astrophysics Data System (ADS)

Kawahara, Toshikazu; Yoshida, Masamichi; Tanaka, Masashi; Ido, Sanyu; Nakano, Hiroyuki; Adachi, Naokaka; Abe, Yuichi; Nagatomo, Wataru

2011-03-01

Critical Dimension Scanning Electron Microscope (CD-SEM) recipe creation needs sample preparation necessary for matching pattern registration, and recipe creation on CD-SEM using the sample, which hinders the reduction in test production cost and time in semiconductor manufacturing factories. From the perspective of cost reduction and improvement of the test production efficiency, automated CD-SEM recipe creation without the sample preparation and the manual operation has been important in the production lines. For the automated CD-SEM recipe creation, we have introduced RecipeDirector (RD) that enables the recipe creation by using Computer-Aided Design (CAD) data and text data that includes measurement information. We have developed a system that automatically creates the CAD data and the text data necessary for the recipe creation on RD; and, for the elimination of the manual operation, we have enhanced RD so that all measurement information can be specified in the text data. As a result, we have established an automated CD-SEM recipe creation system without the sample preparation and the manual operation. For the introduction of the CD-SEM recipe creation system using RD to the production lines, the accuracy of the pattern matching was an issue. The shape of design templates for the matching created from the CAD data was different from that of SEM images in vision. Thus, a development of robust pattern matching algorithm that considers the shape difference was needed. The addition of image processing of the templates for the matching and shape processing of the CAD patterns in the lower layer has enabled the robust pattern matching. This paper describes the automated CD-SEM recipe creation technology for the production lines without the sample preparation and the manual operation using RD applied in Sony Semiconductor Kyusyu Corporation Kumamoto Technology Center (SCK Corporation Kumamoto TEC).

Laboratory-based clinical audit as a tool for continual improvement: an example from CSF chemistry turnaround time audit in a South-African teaching hospital

PubMed Central

Imoh, Lucius C; Mutale, Mubanga; Parker, Christopher T; Erasmus, Rajiv T; Zemlin, Annalise E

2016-01-01

Introduction Timeliness of laboratory results is crucial to patient care and outcome. Monitoring turnaround times (TAT), especially for emergency tests, is important to measure the effectiveness and efficiency of laboratory services. Laboratory-based clinical audits reveal opportunities for improving quality. Our aim was to identify the most critical steps causing a high TAT for cerebrospinal fluid (CSF) chemistry analysis in our laboratory. Materials and methods A 6-month retrospective audit was performed. The duration of each operational phase across the laboratory work flow was examined. A process-mapping audit trail of 60 randomly selected requests with a high TAT was conducted and reasons for high TAT were tested for significance. Results A total of 1505 CSF chemistry requests were analysed. Transport of samples to the laboratory was primarily responsible for the high average TAT (median TAT = 170 minutes). Labelling accounted for most delays within the laboratory (median TAT = 71 minutes) with most delays occurring after regular work hours (P < 0.05). CSF chemistry requests without the appropriate number of CSF sample tubes were significantly associated with delays in movement of samples from the labelling area to the technologist’s work station (caused by a preference for microbiological testing prior to CSF chemistry). Conclusion A laboratory-based clinical audit identified sample transportation, work shift periods and use of inappropriate CSF sample tubes as drivers of high TAT for CSF chemistry in our laboratory. The results of this audit will be used to change pre-analytical practices in our laboratory with the aim of improving TAT and customer satisfaction. PMID:27346964

MX Resident Engineer Networking Guide.

DTIC Science & Technology

1982-04-01

FIGURES 6 INTRODUCTION ............................................................ 11 Background Approach Purpose Scope 2 SYSTEM OVERVIEW...RESIDENT ENGINEER NETWORKING GUIDE 1 INTRODUCTION Background The Network Analysis System (NAS) is not a new planning method. It has been used for more than...DEVELOPMENT RUN DATE 19MAY7’ 2359MRS S U M M A R I P A Y N L N T S S T A I I M E N I PROJECT START jAUG ?? PROJECT EXR 4 L1 SAMPLE PNOPLEM *ACTIVITT-YN

Microfabricated electrochemical sensors for combustion applications

NASA Astrophysics Data System (ADS)

Vulcano Rossi, Vitor A.; Mullen, Max R.; Karker, Nicholas A.; Zhao, Zhouying; Kowarz, Marek W.; Dutta, Prabir K.; Carpenter, Michael A.

2015-05-01

A new design for the miniaturization of an existing oxygen sensor is proposed based on the application of silicon microfabrication technologies to a cm sized O2 sensor demonstrated by Argonne National Laboratory and The Ohio State University which seals a metal/metal oxide within the structure to provide an integrated oxygen reference. The structural and processing changes suggested will result in a novel MEMS-based device meeting the semiconductor industry standards for cost efficiency and mass production. The MEMS design requires thin film depositions to create a YSZ membrane, palladium oxide reference and platinum electrodes. Pt electrodes are studied under operational conditions ensuring film conductivity over prolonged usage. SEM imaging confirms void formation after extended tests, consistent with the literature. Furthermore, hydrophilic bonding of pairs of silicon die samples containing the YSZ membrane and palladium oxide is discussed in order to create hermetic sealed cavities for oxygen reference. The introduction of tensile Si3N4 films to the backside of the silicon die generates bowing of the chips, compromising bond quality. This effect is controlled through the application of pressure during the initial bonding stages. In addition, KOH etching of the bonded die samples is discussed, and a YSZ membrane that survives the etching step is characterized by Raman spectroscopy.

Co-liquefaction with acetone and GC analysis of volatile compounds in exhaled breath as lung cancer biomarkers

PubMed Central

Jouyban, Abolghasem; Djozan, Djavanshir; Mohammadandashti, Parastou; Alizadeh-Nabil, Aliakbar; Ghorbanpour, Hooshangh; Khoubnasabjafari, Maryam; Mohammadzadeh, Mohammad

2017-01-01

Introduction: A simple, rapid and low cost method for enrichment of volatile organic compounds (VOCs) from exhaled breath (EB) is presented. Methods: A 1000 mL home-made extraction device was filled with EB. The VOCs were extracted and condensed in 0.5 mL acetone. Recognition of volatiles in the real studied EB samples was performed by a GC-MS. Results: The method displays an extraction efficiency of >86% with the enrichment factor of 1929 for octanal. Limits of detection and quantification, and linear dynamic range were 0.008, 0.026 and 0.026-400 ng/mL respectively. Analysis of real samples showed the existence of more than 100 compounds in EB of healthy volunteers and patients with lung cancer before and after treatment. Exhaled octanal concentration was significantly higher in lung cancer patient than in healthy volunteers and lung cancer patient after treatment. Conclusion: Having used the proposed approach, high extraction recovery (up to 86%) was attained for the lung cancer marker, octanal, as an important biomarker. Our findings on smaples of EB of healthy controls and patients with lung cancer before and after treatment provide complelling evidence upon the effectiveness of the developed method. PMID:28752074

Current strategies for protein production and purification enabling membrane protein structural biology.

PubMed

Pandey, Aditya; Shin, Kyungsoo; Patterson, Robin E; Liu, Xiang-Qin; Rainey, Jan K

2016-12-01

Membrane proteins are still heavily under-represented in the protein data bank (PDB), owing to multiple bottlenecks. The typical low abundance of membrane proteins in their natural hosts makes it necessary to overexpress these proteins either in heterologous systems or through in vitro translation/cell-free expression. Heterologous expression of proteins, in turn, leads to multiple obstacles, owing to the unpredictability of compatibility of the target protein for expression in a given host. The highly hydrophobic and (or) amphipathic nature of membrane proteins also leads to challenges in producing a homogeneous, stable, and pure sample for structural studies. Circumventing these hurdles has become possible through the introduction of novel protein production protocols; efficient protein isolation and sample preparation methods; and, improvement in hardware and software for structural characterization. Combined, these advances have made the past 10-15 years very exciting and eventful for the field of membrane protein structural biology, with an exponential growth in the number of solved membrane protein structures. In this review, we focus on both the advances and diversity of protein production and purification methods that have allowed this growth in structural knowledge of membrane proteins through X-ray crystallography, nuclear magnetic resonance (NMR) spectroscopy, and cryo-electron microscopy (cryo-EM).

Current strategies for protein production and purification enabling membrane protein structural biology

PubMed Central

Pandey, Aditya; Shin, Kyungsoo; Patterson, Robin E.; Liu, Xiang-Qin; Rainey, Jan K.

2017-01-01

Membrane proteins are still heavily underrepresented in the protein data bank (PDB) due to multiple bottlenecks. The typical low abundance of membrane proteins in their natural hosts makes it necessary to overexpress these proteins either in heterologous systems or through in vitro translation/cell-free expression. Heterologous expression of proteins, in turn, leads to multiple obstacles due to the unpredictability of compatibility of the target protein for expression in a given host. The highly hydrophobic and/or amphipathic nature of membrane proteins also leads to challenges in producing a homogeneous, stable, and pure sample for structural studies. Circumventing these hurdles has become possible through introduction of novel protein production protocols; efficient protein isolation and sample preparation methods; and, improvement in hardware and software for structural characterization. Combined, these advances have made the past 10–15 years very exciting and eventful for the field of membrane protein structural biology, with an exponential growth in the number of solved membrane protein structures. In this review, we focus on both the advances and diversity of protein production and purification methods that have allowed this growth in structural knowledge of membrane proteins through X-ray crystallography, nuclear magnetic resonance (NMR) spectroscopy, and cryo-electron microscopy (cryo-EM). PMID:27010607

Investigating the widespread introduction of a tropical marine fouling species.

PubMed

Sheets, Elizabeth A; Cohen, C Sarah; Ruiz, Gregory M; da Rocha, Rosana M

2016-04-01

Little is known about the number and rate of introductions into terrestrial and marine tropical regions, and if introduction patterns and processes differ from temperate latitudes. Botryllid ascidians (marine invertebrate chordates) are an interesting group to study such introduction differences because several congeners have established populations across latitudes. While temperate botryllid invasions have been repeatedly highlighted, the global spread of tropical Botrylloides nigrum (Herdman, 1886) has been largely ignored. We sampled B. nigrum from 16 worldwide warm water locations, including around the Panama Canal, one of the largest shipping hubs in the world and a possible introduction corridor. Using mitochondrial (COI) and nuclear (ANT) markers, we discovered a single species with low genetic divergence and diversity that has established in the Atlantic, Pacific, Indo-Pacific, and Mediterranean Oceans. The Atlantic Ocean contained the highest diversity and multilocus theta estimates and may be a source for introductions to other regions. A high frequency of one mitochondrial haplotype was detected in Pacific populations that may represent a recent introduction in this region. In comparison to temperate relatives, B. nigrum displayed lower (but similar to temperate Botrylloides violaceus) genetic divergence and diversity at both loci that may represent a more recent global spread or differences in introduction pressures in tropical regions. Additionally, chimeras (genetically distinct individuals sharing a single body) were detected in three populations by the mitochondrial locus and validated using cloning, and these individuals contained new haplotype diversity not detected in any other colonies.

Family and infant characteristics associated with timing of core and non-core food introduction in early childhood.

PubMed

Schrempft, S; van Jaarsveld, C H M; Fisher, A; Wardle, J

2013-06-01

To identify family and infant characteristics associated with timing of introduction of two food types: core foods (nutrient-dense) and non-core foods (nutrient-poor) in a population-based sample of mothers and infants. Participants were 1861 mothers and infants from the Gemini twin birth cohort (one child per family). Family and infant characteristics were assessed when the infants were around 8 months old. Timing of introducing core and non-core foods was assessed at 8 and 15 months. As the distributions of timing were skewed, three similar-sized groups were created for each food type: earlier (core: 1-4 months; non-core: 3-8 months), average (core: 5 months; non-core: 9-10 months) and later introduction (core: 6-12 months; non-core: 11-18 months). Ordinal logistic regression was used to examine predictors of core and non-core food introduction, with bootstrapping to test for differences between the core and non-core models. Younger maternal age, lower education level and higher maternal body mass index were associated with earlier core and non-core food introduction. Not breastfeeding for at least 3 months and higher birth weight were specifically associated with earlier introduction of core foods. Having older children was specifically associated with earlier introduction of non-core foods. There are similarities and differences in the characteristics associated with earlier introduction of core and non-core foods. Successful interventions may require a combination of approaches to target both food types.

Cost effectiveness of adding nucleic acid testing to hepatitis B, hepatitis C, and human immunodeficiency virus screening of blood donations in Zimbabwe.

PubMed

Mafirakureva, Nyashadzaishe; Mapako, Tonderai; Khoza, Star; Emmanuel, Jean C; Marowa, Lucy; Mvere, David; Postma, Maarten J; van Hulst, Marinus

2016-12-01

The aim of this study was to assess the cost effectiveness of introducing individual-donation nucleic acid testing (ID-NAT), in addition to serologic tests, compared with the exclusive use of serologic tests for the identification of hepatitis B virus (HBV), hepatitis C virus (HCV), and human immunodeficiency virus (HIV) I and II among blood donors in Zimbabwe. The costs, health consequences, and cost effectiveness of adding ID-NAT to serologic tests, compared with serologic testing alone, were estimated from a health care perspective using a decision-analytic model. The introduction of ID-NAT in addition to serologic tests would lower the risk of HBV, HCV, and HIV transmission to 46.9, 0.3, and 2.7 per 100,000 donations, respectively. ID-NAT would prevent an estimated 25, 6, and 9 HBV, HCV, and HIV transfusion-transmitted infections per 100,000 donations, respectively. The introduction of this intervention would result in an estimated 212 quality-adjusted life-years (QALYs) gained. The incremental cost-effectiveness ratio is estimated at US$17,774/QALY, a value far more than three times the gross national income per capita for Zimbabwe. Although the introduction of NAT could further improve the safety of the blood supply, current evidence suggests that it cannot be considered cost effective. Reducing the test costs for NAT through efficient donor recruitment, negotiating the price of reagents, and the efficient use of technology will improve cost effectiveness. © 2016 AABB.

Impact assessment of the introduction of Cichla kelberi in a large Neotropical reservoir and its lateral lagoons (Upper Paraná River Basin, Brazil).

PubMed

Ferrareze, M; Nogueira, M G

2015-11-01

This study aimed to understand how the introduction of Cichla kelberi in Rosana Reservoir (Paranapanema River) affected the native ichthyofauna. Data on the structure of the small fish fauna assemblage were obtained before and after the introduction of this carnivorous species. Samplings were carried out in February and September of 2004, previously to the register of Cichla kelberi in the reservoir, and after its introduction, November of 2004, January, March, May and August of 2005, February and June of 2006, February and July of 2007, February and October of 2008 and February of 2009. A total of 4,693 fish, belonging to 43 different species was sampled between 2004 and 2009. The order Characiformes was the most abundant, followed by Perciformes and Siluriformes. Comparative analyses, before and after the introduction, could not demonstrate significant changes in composition, richness, abundance, biomass, mean length and diversity of fish. Aquatic insects were the main feeding item of C. kelberi, followed by tetragonopterinae fish. Cannibalism was recorded during the whole study period. The results showed that Cichla cannot deeply affect the ichthyofauna assemblages of a large Neotropical reservoir, at least in a short or medium term period after its introduction. The results also allowed concluding that the introduction of C. kelberi in the reservoir is in the phase 3. In this phase, the specie can survive and reproduce in the new environment; however it is not totally established and disseminated. The reasons for the fact that Cichla is still not dominant in Rosana Reservoir could be related to feeding competition, high rate of cannibalism and the presence of large amount of aquatic macrophytes (refuge zones). In spite of the results, the continuous monitoring of the role of non-native species on the local fish fauna is absolutely necessary because the impacts caused by colonization of this undesirable species can be magnified by complex processes, usually correlated with other environmental disturb, especially the negative effects of damming.

Development of a Microfluidic Open Interface with Flow Isolated Desorption Volume for the Direct Coupling of SPME Devices to Mass Spectrometry.

PubMed

Tascon, Marcos; Alam, Md Nazmul; Gómez-Ríos, Germán Augusto; Pawliszyn, Janusz

2018-02-20

Technologies that efficiently integrate the sampling and sample preparation steps with direct introduction to mass spectrometry (MS), providing simple and sensitive analytical workflows as well as capabilities for automation, can generate a great impact in a vast variety of fields, such as in clinical, environmental, and food-science applications. In this study, a novel approach that facilitates direct coupling of Bio-SPME devices to MS using a microfluidic design is presented. This technology, named microfluidic open interface (MOI), which operates under the concept of flow-isolated desorption volume, consists of an open-to-ambient desorption chamber (V ≤ 7 μL) connected to an ionization source. Subsequently, compounds of interest are transported to the ionization source by means of the self-aspiration process intrinsic of these interfaces. Thus, any ionization technology that provides a reliable and constant suction, such as electrospray ionization (ESI), atmospheric-pressure chemical ionization (APCI), or inductively coupled plasma ionization (ICP), can be hyphenated to MOI. Using this setup, the desorption chamber is used to release target compounds from the coating, while the isolation of the flow enables the ionization source to be continuously fed with solvent, all without the necessity of employment of additional valves. As a proof of concept, the design was applied to an ESI-MS/MS system for experimental validation. Furthermore, numerical simulations were undertaken to provide a detailed understanding of the fluid flow pattern inside the interface, then used to optimize the system for better efficiency. The analytical workflow of the developed Bio-SPME-MOI-MS setup consists of the direct immersion of SPME fibers into the matrix to extract/enrich analytes of interest within a short period of time, followed by a rinsing step with water to remove potentially adhering proteins, salts, and/or other interfering compounds. Next, the fiber is inserted into the MOI for desorption of compounds of interest. Finally, the volume contained in the chamber is drained and moved toward the electrospray needle for ionization and direct introduction to MS. Aiming to validate the technology, the fast determination of selected immunosuppressive drugs (e.g., tacrolimus, cyclosporine, sirolimus, and everolimus) from 100 μL of whole blood was assessed. Limits of quantitation in the subppb range were obtained for all studied compounds. Good linearity (r 2 ≥ 0.99) and excellent precision, with (8%) and without (14%) internal standard correction, were attained.

Technical Aspects of Use of Ultrasound for Intensification of Enzymatic Bio-Processing: New Path to "Green Chemistry"

USDA-ARS?s Scientific Manuscript database

Use of enzymatic processing in the food, textile, and bio-fuel applications is becoming increasingly popular, primarily because of rapid introduction of a new variety of highly efficient enzymes. In general, an enzymatic bio-processing generates less toxic and readily biodegradable wastewater efflue...

Powder from cedar heartwood affects oviposition behavior in Coleomegilla maculata: a ladybird native to the Americas

USDA-ARS?s Scientific Manuscript database

Introduction: Coleomegilla maculata is a predatory ladybird inhabiting ecosystems in North, Central, and South America. The aim of our research is to discover efficient, low-cost materials that boost oviposition in mass-reared C. maculata fed non-natural foods. We tested the hypothesis that eastern ...

Successful School Board Meetings. A Special Edition for New Jersey School Boards.

ERIC Educational Resources Information Center

Anderson, Stuart A.

This handbook was written to help school boards conduct routine business meetings more efficiently, and thereby improve their ability to reach constructive decisions and solve problems. After a brief introduction, the first chapter focuses on organizing the new school board, electing officers, adopting policies, and appointing committees. The…

Turbocharged Diesels

NASA Technical Reports Server (NTRS)

1984-01-01

In a number of feasibility studies of turbine rotor designs, engineers of Cummins Engine Company, Inc.'s turbocharger group have utilized a computer program from COSMIC. Part of Cummins research effort is aimed toward introduction of advanced turbocharged engines that deliver extra power with greater fuel efficiency. Company claims use of COSMIC program substantially reduced software development costs.

Women's Energy Tool Kit: Home Heating, Cooling and Weatherization.

ERIC Educational Resources Information Center

Byalin, Joan

This book is the first in a series of Energy Tool Kits designed for women by Consumer Action Now, a non-profit organization devoted to promoting energy efficiency and renewable energy resources. Information is provided in 16 sections: introduction, home energy survey; caulking; weatherstripping (double-hung and sliding windows, and casement,…

The Budget. Introduction to Financial Management.

ERIC Educational Resources Information Center

Strong, Dexter K.

A school budget is a carefully drawn plan to allow for the efficient educational operation of the school. Everyone connected with the management of an independent school has something to learn about a budget, the most obvious person being the new headmaster. Similarly, all department heads, the librarian, the athletic director, the members of the…

Privatizing Education: Can the Marketplace Deliver Choice, Efficiency, Equity, and Social Cohesion?

ERIC Educational Resources Information Center

Levin, Henry M., Ed.

This collection of essays examines efforts by groups and lobbyists to move education from the public to the private sector. There are 14 papers in 7 sections: The first section, "Introduction," includes: (1) "Studying Privatization in Education" (Henry M. Levin) and (2) "Educational Vouchers and the Media" (Lee D.…

Two Different Organizational Reactions: The University Sector in Argentina and Colombia and the Neoliberal Proposal

ERIC Educational Resources Information Center

Rabossi, Marcelo

2009-01-01

The neoliberal reform arrived at the market of higher education with the intention of introducing private dynamics into public organizations. Through this strategy, the objective was to improve efficiency by promoting intra- and intersectoral competition. The introduction of performance funding shifted the concept of accountability for…

Motivational, Volitional and Metacognitive Aspects of Self Regulated Learning

ERIC Educational Resources Information Center

Gaeta, Martha Leticia; Teruel, M. Pilar; Orejudo, Santos

2012-01-01

Introduction: Today one of the main objectives of education is to help students to become autonomous and efficient learners. This is only possible to the extent that students self-regulate their own learning. Hence, the purpose of this study was to study some contextual and personal factors that facilitate this process. Method: Participants were…

Enhancing E-Learning Quality through the Application of the AKUE Procedure Model

ERIC Educational Resources Information Center

Bremer, C.

2012-01-01

The paper describes the procedure model AKUE, which aims at the improvement and assurance of quality and cost efficiency in the context of the introduction of e-learning and the development of digital learning material. AKUE divides the whole planning and implementation process into four different phases: analysis, conception, implementation, and…

Integration of Video-Based Demonstrations to Prepare Students for the Organic Chemistry Laboratory

ERIC Educational Resources Information Center

Nadelson, Louis S.; Scaggs, Jonathan; Sheffield, Colin; McDougal, Owen M.

2015-01-01

Consistent, high-quality introductions to organic chemistry laboratory techniques effectively and efficiently support student learning in the organic chemistry laboratory. In this work, we developed and deployed a series of instructional videos to communicate core laboratory techniques and concepts. Using a quasi-experimental design, we tested the…

Energy Productivity: Key to Environmental Protection and Economic Progress. Worldwatch Paper 63.

ERIC Educational Resources Information Center

Chandler, William U.

This report examines various topics and issues related to worldwide energy productivity and energy conservation. Following an introduction, these issues are considered in 6 sections focusing on: (1) energy demand projections (with data on 1982 energy consumption in selected countries); (2) continued industrial efficiency gains (including data on…

Aeronautical mobile satellite service: Air traffic control applications

NASA Technical Reports Server (NTRS)

Sim, Dave

1990-01-01

Canada's history both in aviation and in satellite communications development spans several decades. The introduction of aeronautical mobile satellite communications will serve our requirements for airspace management in areas not served by line-of-sight radio and radar facilities. The ensuing improvements in air safety and operating efficiency are eagerly awaited by the aviation community.

Diagnose Nutricional de Cultivares de Milho (Zea mays L.) de Diferentes Níveis Tecnológicos

USDA-ARS?s Scientific Manuscript database

The introduction of hybrids has contributed to increases in grain production. However, there is little work examining the relationship of genetic improvement to nutrient use efficiency, concentration, and export. The objective of this study was to evaluate changes in nutritional status of five maize...

Optical, Physical, and Chemical Properties of Surface Modified Titanium Dioxide Powders

DTIC Science & Technology

2011-02-01

coefficient depends on the optical efficiency factor, QCM , the geometric cross section, G, and the particle mass as indicated by the relationship in eq 2...diffraction sensor with a RODOS powder dispersing unit. The instrument houses a HeNe laser (632.8 nm) and Fourier lens. Upon introduction of the

Information Communication Technology Policy and Public Primary Schools' Efficiency in Rwanda

ERIC Educational Resources Information Center

Munyengabe, Sylvestre; Haiyan, He; Yiyi, Zhao

2018-01-01

Teaching and learning processes have been developed through different methods and materials; nowadays the introduction of computers and other ICT tools in different forms and levels of education have been found to be highly influential in education system of different countries. The main objective of this study was to correlate Information…

Physician Preferences for Accredited Online Continuing Medical Education

ERIC Educational Resources Information Center

Young, Kevin J.; Kim, Julie J.; Yeung, George; Sit, Christina; Tobe, Sheldon W.

2011-01-01

Introduction: The need for up-to-date and high-quality continuing medical education (CME) is growing while the financial investment in CME is shrinking. Despite online technology's potential to efficiently deliver electronic CME (eCME) to large numbers of users, it has not yet displaced traditional CME. The purpose of this study was to explore…

The impact of science and technology on the civilization.

PubMed

Arber, Werner

2009-01-01

The rapid increase of available scientific knowledge is largely due to the introduction of novel research strategies. The application of these strategies, both in fundamental and in translational scientific research, leads to bursts of technological innovations. In order to fulfill the justified public request for sustainability of technological innovations that contribute to the shaping of the future, increasing attention should be given to science-based technology and policy assessment. These requests are illustrated by benefit/risk evaluations of relevance for the use of genetic engineering as an efficient and effective research strategy. Expected benefits of a responsibly planned introduction of GM crops are outlined as a prospective example for the guiding theme "Biotechnology for sustainability of human society".

Retooling microorganisms for the fermentative production of alcohols.

PubMed

Toogood, Helen S; Scrutton, Nigel S

2018-04-01

Bioengineering and synthetic biology approaches have revolutionised the field of biotechnology, enabling the introduction of non-native and de novo pathways for biofuels production. This 'retooling' of microorganisms is also applied to the utilisation of mixed carbon components derived from lignocellulosic biomass, a major technical barrier for the development of economically viable fermentations. This review will discuss recent advances in microorganism engineering for efficient production of alcohols from waste biomass. These advances span the introduction of new pathways to alcohols, host modifications for more cost-effective utilisation of lignocellulosic waste and modifications of existing pathways for generating new fuel additives. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Gas chromatography/ion mobility spectrometry as a hyphenated technique for improved explosives detection and analysis

NASA Technical Reports Server (NTRS)

Mercado, AL; Marsden, Paul

1995-01-01

Ion Mobility Spectrometry (IMS) is currently being successfully applied to the problem of on-line trace detection of plastic and other explosives in airports and other facilities. The methods of sample retrieval primarily consist of batch sampling for particulate residue on a filter card for introduction into the IMS. The sample is desorbed into the IMS using air as the carrier and negative ions of the explosives are detected, some as an adduct with a reagent ion such as Cl(-). Based on studies and tests conducted by different airport authorities, this method seems to work well for low vapor pressure explosives such as RDX and PETN, as well as TNT that are highly adsorptive and can be found in nanogram quantities on contaminated surfaces. Recently, the changing terrorist threat and the adoption of new marking agents for plastic explosives has meant that the sample introduction and analysis capabilities of the IMS must be enhanced in order to keep up with other detector developments. The IMS has sufficient analytical resolution for a few threat compounds but the IMS Plasmogram becomes increasingly more difficult to interpret when the sample mixture gets more complex.

Etiology and antimicrobial susceptibility of middle ear fluid pathogens in Costa Rican children with otitis media before and after the introduction of the 7-valent pneumococcal conjugate vaccine in the National Immunization Program: acute otitis media microbiology in Costa Rican children.

PubMed

Abdelnour, Arturo; Arguedas, Adriano; Dagan, Ron; Soley, Carolina; Porat, Nurith; Castrejon, Maria Mercedes; Ortega-Barria, Eduardo; Colindres, Romulo; Pirçon, Jean-Yves; DeAntonio, Rodrigo; Van Dyke, Melissa K

2015-01-01

Acute otitis media (AOM) microbiology was evaluated in children after 7-valent pneumococcal conjugate vaccine (PCV7) introduction in Costa Rica (private sector, 2004; National Immunization Program, 2009). This was a combined prospective and retrospective study conducted in a routine clinical setting in San José, Costa Rica. In the prospective part of the study, which was conducted post-PCV7 introduction (2010-2012), standard bacteriological procedures were used to evaluate the etiology and serotype distribution of middle ear fluid samples collected by tympanocentesis or otorrhea from children aged 3-59 months diagnosed with AOM. E-tests were used to evaluate antimicrobial susceptibility in culture-positive samples. Retrospective data recorded between 1999 and 2004 were used for comparison of bacterial etiology and serotype distribution before and after PCV7 introduction. Statistical significance was evaluated in bivariate analyses at the P-value < 0.05 level (without multiplicity correction). Post-PCV7 introduction, Haemophilus influenzae was detected in 118/456 and Streptococcus pneumoniae in 87/456 AOM episodes. Most H. influenzae isolates (113/118) were non-typeable. H. influenzae was more (27.4% vs 20.8%) and S. pneumoniae less (17.1% vs 25.5%) frequently observed in vaccinated (≥ 2 PCV7 doses or ≥ 1 PCV7 dose at >1 year of age) versus unvaccinated children. S. pneumoniae non-susceptibility rates were 1.1%, 34.5%, 31.7%, and 50.6% for penicillin, erythromycin, azithromycin, and trimethoprim/sulfamethoxazole (TMP-SMX), respectively. H. influenzae non-susceptibility rate was 66.9% for TMP-SMX. Between pre- and post-PCV7 introduction, H. influenzae became more (20.5% vs 25.9%; P-value < 0.001) and S. pneumoniae less (27.7% vs 19.1%; P-value = 0.002) prevalent, and PCV7 serotype proportions decreased among pneumococcal isolates (65.8% vs 43.7%; P-value = 0.0005). Frequently identified pneumococcal serotypes were 19F (34.2%), 3 (9.7%), 6B (9.7%), and 14 (9.7%) pre-PCV7 introduction, and 19F (27.6%), 14 (8.0%), and 35B (8.0%) post-PCV7 introduction. Following PCV7 introduction, a change in the distribution of AOM episodes caused by H. influenzae and pneumococcal serotypes included in PCV7 was observed in Costa Rican children. Pneumococcal vaccines impact should be further evaluated following broader vaccination coverage.

Effects of the Spock Videogame on Improving Emotional Intelligence in Adolescents

ERIC Educational Resources Information Center

Cejudo, Javier; Latorre, Sebastián

2015-01-01

Introduction: The aim of the present research is to experimentally assess the effects of a videogame program ("Spock") for improving emotional intelligence (EI) as an ability among a sample of adolescents. Method: The sample was made up of 92 adolescents, aged 17 to 19, who were currently studying the second year of…

INTRODUCTION OF THE VITELLOGENIN GENE IN EARLY LIFE STAGE FATHEAD MINNOWS AS AN EFFECTIVE EXPOSURE INDICATOR FOR ESTROGENIC COMPOUNDS

EPA Science Inventory

Vitellogenin (Vg) gene expression in adult male fathead minnows (FHM) has previously been used successfully to detect exposures to estrogenic compounds in aquatic systems; however, sample volume(s)required for >24h exposure durations and the logistics of sampling pose some limita...

Capabilities of Direct Sample Introduction - Comprehensive Two-Dimensional Gas Chromatgraphy-Time-of-Flight Mass Spectrometry to Analyze Organic Chemicals of Interest in Fish Oils

USDA-ARS?s Scientific Manuscript database

Most analytical methods for persistent organic pollutants (POPs) focus on targeted analytes. Therefore, analysis of multiple classes of POPs typically entails several sample preparations, fractionations, and injections, whereas other chemicals of possible interest are neglected. To analyze a wider...

Advances in the measurement of sulfur isotopes by multi-collector ICP-MS (MC-ICP- MS)

NASA Astrophysics Data System (ADS)

Ridley, W. I.; Wilson, S. A.; Anthony, M. W.

2006-12-01

The demonstrated capability to measure 34S/32S by MC-ICP-MS with a precision (2ó) of ~0.2 per mil has many potential applications in geochemistry. However, a number of obstacles limit this potential. First, to achieve the precision indicated above requires sufficient mass resolution to separate isobaric interferences of 16O2 and 17O2 on 32S and 34S, respectively. These requirements for high resolution mean overall instrument sensitivity is reduced. Second, current methods preclude analysis of samples with complex matrices, a common characteristic of sulfur-bearing geologic materials. Here, we describe and discuss a method that provides both efficient removal of matrix constituents, and provides pre-concentration of S, thus overcoming these obstacles. The method involves the separation of sulfur from matrix constituents by high pressure (1000 psi) ion chromatography (HPIC), followed by isotope measurement using MC-ICP-MS. This combination allows for analysis of liquid samples with a wide range of S concentrations. A powerful advantage of this technique is the efficient separation of many sulfur species from matrix cations and anions (for instance in a seawater or acid mine drainage matrix), as well as the separation of sulfur species, e.g., sulfate, sulfite, thiosulfate, thiocynate, from each other for isotope analysis. The automated HPIC system uses a carbonate-bicarbonate eluent with eluent suppression, and has sufficient baseline separation to collect the various sulfur species as pure fractions. The individual fractions are collected over a specific time interval based upon a pre-determined elution profile and peak retention times. The addition of a second ion exchange column into the system allows pre-concentration of sulfur species by 2-3 orders of magnitude for samples that otherwise would have sulfur concentrations too low to provide precise isotopic ratios. The S isotope ratios are measured by MC-ICP-MS using a desolvating sample introduction system, a standard-sample bracketing method employing standards that are well characterized for sulfur isotope composition using stable isotope gas mass spectrometry. Data are collected in time-resolved mode, which reduces analytical time and allows for flexibility in data integration. Preliminary data indicates that sulfur species do not fractionate during the column chemistry.

Bi2S3microspheres grown on graphene sheets as low-cost counter-electrode materials for dye-sensitized solar cells

NASA Astrophysics Data System (ADS)

Li, Guang; Chen, Xiaoshuang; Gao, Guandao

2014-02-01

In this work, we synthesized 3D Bi2S3 microspheres comprised of nanorods grown along the (211) facet on graphene sheets by a solvothermal route, and investigated its catalytic activities through I-V curves and conversion efficiency tests as the CE in DSSCs. Although the (211) facet has a large band gap for a Bi2S3 semiconductor, owing to the introduction of graphene into the system, its short-circuit current density, open-circuit voltage, fill factor, and efficiency were Jsc = 12.2 mA cm-2, Voc = 0.75 V, FF = 0.60, and η = 5.5%, respectively. By integrating it with graphene sheets, our material achieved the conversion efficiency of 5.5%, which is almost triple the best conversion efficiency value of the DSSCs with (211)-faceted 3D Bi2S3 without graphene (1.9%) reported in the latest literature. Since this conversion-efficient 3D material grown on the graphene sheets significantly improves its catalytic properties, it paves the way for designing and applying low-cost Pt-free CE materials in DSSC from inorganic nanostructures.In this work, we synthesized 3D Bi2S3 microspheres comprised of nanorods grown along the (211) facet on graphene sheets by a solvothermal route, and investigated its catalytic activities through I-V curves and conversion efficiency tests as the CE in DSSCs. Although the (211) facet has a large band gap for a Bi2S3 semiconductor, owing to the introduction of graphene into the system, its short-circuit current density, open-circuit voltage, fill factor, and efficiency were Jsc = 12.2 mA cm-2, Voc = 0.75 V, FF = 0.60, and η = 5.5%, respectively. By integrating it with graphene sheets, our material achieved the conversion efficiency of 5.5%, which is almost triple the best conversion efficiency value of the DSSCs with (211)-faceted 3D Bi2S3 without graphene (1.9%) reported in the latest literature. Since this conversion-efficient 3D material grown on the graphene sheets significantly improves its catalytic properties, it paves the way for designing and applying low-cost Pt-free CE materials in DSSC from inorganic nanostructures. Electronic supplementary information (ESI) available. See DOI: 10.1039/c3nr06093d

Use of the probiotic Lactobacillus plantarum 299 to reduce pathogenic bacteria in the oropharynx of intubated patients: a randomised controlled open pilot study

PubMed Central

Klarin, Bengt; Molin, Göran; Jeppsson, Bengt; Larsson, Anders

2008-01-01

Introduction Ventilator-associated pneumonia (VAP) is usually caused by aspiration of pathogenic bacteria from the oropharynx. Oral decontamination with antiseptics, such as chlorhexidine (CHX) or antibiotics, has been used as prophylaxis against this complication. We hypothesised that the probiotic bacteria Lactobacillus plantarum 299 (Lp299) would be as efficient as CHX in reducing the pathogenic bacterial load in the oropharynx of tracheally intubated, mechanically ventilated, critically ill patients. Methods Fifty critically ill patients on mechanical ventilation were randomised to either oral mechanical cleansing followed by washing with 0.1% CHX solution or to the same cleansing procedure followed by oral application of an emulsion of Lp299. Samples for microbiological analyses were taken from the oropharynx and trachea at inclusion and at defined intervals thereafter. Results Potentially pathogenic bacteria that were not present at inclusion were identified in oropharyngeal samples from eight of the patients treated with Lp299 and 13 of those treated with CHX (p = 0.13). Analysis of tracheal samples yielded similar results. Lp299 was recovered from the oropharynx of all patients in the Lp299 group. Conclusions In this pilot study, we found no difference between the effect of Lp299 and CHX used in oral care procedures, when we examined the effects of those agents on colonisation of potentially pathogenic bacteria in the oropharynx of intubated, mechanically ventilated patients. PMID:18990201

Effects of Tip Clearance and Casing Recess on Heat Transfer and Stage Efficiency in Axial Turbines

NASA Technical Reports Server (NTRS)

Ameri, A. A.; Steinthorsson, E.; Rigby, David L.

1998-01-01

Calculations were performed to assess the effect of the tip leakage flow on the rate of heat transfer to blade, blade tip and casing. The effect on exit angle and efficiency was also examined. Passage geometries with and without casing recess were considered. The geometry and the flow conditions of the GE-E 3 first stage turbine, which represents a modem gas turbine blade were used for the analysis. Clearance heights of 0%, 1%, 1.5% and 3% of the passage height were considered. For the two largest clearance heights considered, different recess depths were studied. There was an increase in the thermal load on all the heat transfer surfaces considered due to enlargement of the clearance gap. Introduction of recessed casing resulted in a drop in the rate of heat transfer on the pressure side but the picture on the suction side was found to be more complex for the smaller tip clearance height considered. For the larger tip clearance height the effect of casing recess was an orderly reduction in the suction side heat transfer as the casing recess height was increased. There was a marked reduction of heat load and peak values on the blade tip upon introduction of casing recess, however only a small reduction was observed on the casing itself. It was reconfirmed that there is a linear relationship between the efficiency and the tip gap height. It was also observed that the recess casing has a small effect on the efficiency but can have a moderating effect on the flow underturning at smaller tip clearances.

An introduction to medical statistics for health care professionals: Hypothesis tests and estimation.

PubMed

Thomas, Elaine

2005-01-01

This article is the second in a series of three that will give health care professionals (HCPs) a sound introduction to medical statistics (Thomas, 2004). The objective of research is to find out about the population at large. However, it is generally not possible to study the whole of the population and research questions are addressed in an appropriate study sample. The next crucial step is then to use the information from the sample of individuals to make statements about the wider population of like individuals. This procedure of drawing conclusions about the population, based on study data, is known as inferential statistics. The findings from the study give us the best estimate of what is true for the relevant population, given the sample is representative of the population. It is important to consider how accurate this best estimate is, based on a single sample, when compared to the unknown population figure. Any difference between the observed sample result and the population characteristic is termed the sampling error. This article will cover the two main forms of statistical inference (hypothesis tests and estimation) along with issues that need to be addressed when considering the implications of the study results. Copyright (c) 2005 Whurr Publishers Ltd.

Multisystem altruistic metadynamics—Well-tempered variant

NASA Astrophysics Data System (ADS)

Hošek, Petr; Kříž, Pavel; Toulcová, Daniela; Spiwok, Vojtěch

2017-03-01

Metadynamics method has been widely used to enhance sampling in molecular simulations. Its original form suffers two major drawbacks, poor convergence in complex (especially biomolecular) systems and its serial nature. The first drawback has been addressed by introduction of a convergent variant known as well-tempered metadynamics. The second was addressed by introduction of a parallel multisystem metadynamics referred to as altruistic metadynamics. Here, we combine both approaches into well-tempered altruistic metadynamics. We provide mathematical arguments and trial simulations to show that it accurately predicts free energy surfaces.

Multisystem altruistic metadynamics-Well-tempered variant.

PubMed

Hošek, Petr; Kříž, Pavel; Toulcová, Daniela; Spiwok, Vojtěch

2017-03-28

Metadynamics method has been widely used to enhance sampling in molecular simulations. Its original form suffers two major drawbacks, poor convergence in complex (especially biomolecular) systems and its serial nature. The first drawback has been addressed by introduction of a convergent variant known as well-tempered metadynamics. The second was addressed by introduction of a parallel multisystem metadynamics referred to as altruistic metadynamics. Here, we combine both approaches into well-tempered altruistic metadynamics. We provide mathematical arguments and trial simulations to show that it accurately predicts free energy surfaces.

Recognizing and overcoming analytical error in the use of ICP-MS for the determination of cadmium in breakfast cereal and dietary supplements.

PubMed

Murphy, Karen E; Vetter, Thomas W

2013-05-01

The potential effect of spectral interference on the accurate measurement of the cadmium (Cd) mass fraction in fortified breakfast cereal and a variety of dietary supplement materials using inductively coupled plasma quadrupole mass spectrometry was studied. The materials were two new standard reference materials (SRMs)--SRM 3233 Fortified Breakfast Cereal and SRM 3532 Calcium Dietary Supplement--as well as several existing materials--SRM 3258 Bitter Orange Fruit, SRM 3259 Bitter Orange Extract, SRM 3260 Bitter Orange-containing Solid Oral Dosage Form, and SRM 3280 Multivitamin/Multielement Tablets. Samples were prepared for analysis using the method of isotope dilution and measured using various operating and sample introduction configurations including standard mode, collision cell with kinetic energy discrimination mode, and standard mode with sample introduction via a desolvating nebulizer system. Three isotope pairs, (112)Cd/(111)Cd, (113)Cd/(111)Cd, and (114)Cd/(111)Cd, were measured. Cadmium mass fraction results for the unseparated samples of each material, measured using the three instrument configurations and isotope pairs, were compared to the results obtained after the matrix was removed via chemical separation using anion exchange chromatography. In four of the six materials studied, measurements using the standard mode with sample introduction via the desolvating nebulizer gave results for the unseparated samples quantified with the (112)Cd/(111)Cd isotope pair that showed a positive bias relative to the matrix-separated samples, which indicated a persistent inference at m/z112 with this configuration. Use of the standard mode, without the desolvating nebulizer, also gave results that showed a positive bias for the unseparated samples quantified with the (112)Cd/(111)Cd isotope pair in three of the materials studied. Collision cell/kinetic energy discrimination mode, however, was very effective for reducing spectral interference for Cd in all of the materials and isotope pairs studied, except in the multivitamin/multielement matrix (SRM 3280) where the large corrections for known isobaric interferences or unidentified interferences compromised the accuracy. For SRM 3280, matrix separation provided the best method to achieve accurate measurement of Cd.

[Role of socio-economy and management in sustainable transmission control of schistosomiasis in Taoyuan County, Hunan Province, China].

PubMed

Luo, Zhi-Hong; Li, Sheng-Ming; Zhou, Xiao-Nong; Yi, Ping; Ren, Guang-Hui; Franziska, Bieri; Zhao, Zheng-Yuan; Hou, Xun-Ya; Ren, Mao-Yuan; Li, Yi-Yi; Dong, Ru-Lan; Zeng, Jin-Yuan; She, Shu-Ping

2013-02-01

To clarify the role of socio-economy and management in the sustainable schistosomiasis-control in Taoyuan County, an endemic area in hilly region, Hunan Province, China. From 1996 to 2011, the data of socio-economy, the management of schistosomiasis control organizations, environment, and the changes in schistosomiasis prevalence were collected in Taoyuan County where schistosomiasis transmission had been controlled since 2008. A sampling survey of schistosomiasis prevalence of human and bovine was performed in 2011 to verify the current status of schistosomiasis transmission. All the data were analyzed statistically to evaluate the role of socio-economy and management in the sustainable schistosomiasis control. During the period from 1998 to 2012, the socio-economy including the residents' productive mode and daily life in Taoyuan County improved dramatically, but the recurrence risk of schistosomiasis endemic still existed due to the retuning of out-going workers and the migrating population. Moreover, the introduction of exotic species of plants and animals may increase the risk. The low running cost of schistosomiasis control organization as well as the efficient and adequate resource allocation in the county was in line with the national requirement to strengthen the rural grass-roots public health system. The harmonious development of socio-economy and the scientific and efficient health system in Taoyuan County are the key factors for the sustainable transmission control of schistosomiasis.

High-throughput process development: determination of dynamic binding capacity using microtiter filter plates filled with chromatography resin.

PubMed

Bergander, Tryggve; Nilsson-Välimaa, Kristina; Oberg, Katarina; Lacki, Karol M

2008-01-01

Steadily increasing demand for more efficient and more affordable biomolecule-based therapies put a significant burden on biopharma companies to reduce the cost of R&D activities associated with introduction of a new drug to the market. Reducing the time required to develop a purification process would be one option to address the high cost issue. The reduction in time can be accomplished if more efficient methods/tools are available for process development work, including high-throughput techniques. This paper addresses the transitions from traditional column-based process development to a modern high-throughput approach utilizing microtiter filter plates filled with a well-defined volume of chromatography resin. The approach is based on implementing the well-known batch uptake principle into microtiter plate geometry. Two variants of the proposed approach, allowing for either qualitative or quantitative estimation of dynamic binding capacity as a function of residence time, are described. Examples of quantitative estimation of dynamic binding capacities of human polyclonal IgG on MabSelect SuRe and of qualitative estimation of dynamic binding capacity of amyloglucosidase on a prototype of Capto DEAE weak ion exchanger are given. The proposed high-throughput method for determination of dynamic binding capacity significantly reduces time and sample consumption as compared to a traditional method utilizing packed chromatography columns without sacrificing the accuracy of data obtained.

Textured micrometer scale templates as light managing fabrication platform for organic solar cells

DOEpatents

Chaudhary, Sumit; Ho, Kai-Ming; Park, Joong-Mok; Nalwa, Kanwar Singh; Leung, Wai Y.

2016-07-26

A three-dimensional, microscale-textured, grating-shaped organic solar cell geometry. The solar cells are fabricated on gratings to give them a three-dimensional texture that provides enhanced light absorption. Introduction of microscale texturing has a positive effect on the overall power conversion efficiency of the devices. This grating-based solar cell having a grating of pre-determined pitch and height has shown improved power-conversion efficiency over a conventional flat solar cell. The improvement in efficiency is accomplished by homogeneous coverage of the grating with uniform thickness of the active layer, which is attributed to a sufficiently high pitch and low height of the underlying gratings. Also the microscale texturing leads to suppressed reflection of incident light due to the efficient coupling of the incident light into modes that are guided in the active layer.

Production Efficiency and Market Orientation in Food Crops in North West Ethiopia: Application of Matching Technique for Impact Assessment

PubMed Central

Ayenew, Habtamu Yesigat

2016-01-01

Introduction Agricultural technologies developed by national and international research institutions were not benefiting the rural population of Ethiopia to the extent desired. As a response, integrated agricultural extension approaches are proposed as a key strategy to transform the smallholder farming sector. Improving Productivity and Market Success (IPMS) of Ethiopian Farmers project is one of the development projects initiated by integrating productivity enhancement technological schemes with market development model. This paper explores the impact of the project intervention in the smallholder farmers’ wellbeing. Methods To test the research hypothesis of whether the project brought a significant change in the input use, marketed surplus, efficiency and income of farm households, we use a cross-section data from 200 smallholder farmers in Northwest Ethiopia, collected through multi-stage sampling procedure. To control for self-selection from observable characteristics of the farm households, we employ Propensity Score Matching (PSM). We finally use Data Envelopment Analysis (DEA) techniques to estimate technical efficiency of farm households. Results The outcome of the research is in line with the premises that the participation of the household in the IPMS project improves purchased input use, marketed surplus, efficiency of farms and the overall gain from farming. The participant households on average employ more purchased agricultural inputs and gain higher gross margin from the production activities as compared to the non-participant households. The non-participant households on average supply less output (measured both in monetary terms and proportion of total produce) to the market as compared to their participant counterparts. Except for the technical efficiency of production in potato, project participant households are better-off in production efficiency compared with the non-participant counterparts. Conclusion We verified the idea that Improving Productivity and Market Success (IPMS) of Ethiopian farmers’ project has contributed for the input and out market integration and/or market oriented agricultural production. Overall, we argue that these can be seen as an experimental model with a promising potential to improve the livelihood of the poor. Furthermore, we suggest that it is worthwhile to employ integrated agricultural extension programs with further targeting in the developing world. PMID:27391961

Implications of sampling design and sample size for national carbon accounting systems.

PubMed

Köhl, Michael; Lister, Andrew; Scott, Charles T; Baldauf, Thomas; Plugge, Daniel

2011-11-08

Countries willing to adopt a REDD regime need to establish a national Measurement, Reporting and Verification (MRV) system that provides information on forest carbon stocks and carbon stock changes. Due to the extensive areas covered by forests the information is generally obtained by sample based surveys. Most operational sampling approaches utilize a combination of earth-observation data and in-situ field assessments as data sources. We compared the cost-efficiency of four different sampling design alternatives (simple random sampling, regression estimators, stratified sampling, 2-phase sampling with regression estimators) that have been proposed in the scope of REDD. Three of the design alternatives provide for a combination of in-situ and earth-observation data. Under different settings of remote sensing coverage, cost per field plot, cost of remote sensing imagery, correlation between attributes quantified in remote sensing and field data, as well as population variability and the percent standard error over total survey cost was calculated. The cost-efficiency of forest carbon stock assessments is driven by the sampling design chosen. Our results indicate that the cost of remote sensing imagery is decisive for the cost-efficiency of a sampling design. The variability of the sample population impairs cost-efficiency, but does not reverse the pattern of cost-efficiency of the individual design alternatives. Our results clearly indicate that it is important to consider cost-efficiency in the development of forest carbon stock assessments and the selection of remote sensing techniques. The development of MRV-systems for REDD need to be based on a sound optimization process that compares different data sources and sampling designs with respect to their cost-efficiency. This helps to reduce the uncertainties related with the quantification of carbon stocks and to increase the financial benefits from adopting a REDD regime.

Comparison of daily and weekly precipitation sampling efficiencies using automatic collectors

USGS Publications Warehouse

Schroder, L.J.; Linthurst, R.A.; Ellson, J.E.; Vozzo, S.F.

1985-01-01

Precipitation samples were collected for approximately 90 daily and 50 weekly sampling periods at Finley Farm, near Raleigh, North Carolina from August 1981 through October 1982. Ten wet-deposition samplers (AEROCHEM METRICS MODEL 301) were used; 4 samplers were operated for daily sampling, and 6 samplers were operated for weekly-sampling periods. This design was used to determine if: (1) collection efficiences of precipitation are affected by small distances between the Universal (Belfort) precipitation gage and collector; (2) measurable evaporation loss occurs and (3) pH and specific conductance of precipitation vary significantly within small distances. Average collection efficiencies were 97% for weekly sampling periods compared with the rain gage. Collection efficiencies were examined by seasons and precipitation volume. Neither factor significantly affected collection efficiency. No evaporation loss was found by comparing daily sampling to weekly sampling at the collection site, which was classified as a subtropical climate. Correlation coefficients for pH and specific conductance of daily samples and weekly samples ranged from 0.83 to 0.99.Precipitation samples were collected for approximately 90 daily and 50 weekly sampling periods at Finley farm, near Raleigh, North Carolina from August 1981 through October 1982. Ten wet-deposition samplers were used; 4 samplers were operated for daily sampling, and 6 samplers were operated for weekly-sampling periods. This design was used to determine if: (1) collection efficiencies of precipitation are affected by small distances between the University (Belfort) precipitation gage and collector; (2) measurable evaporation loss occurs and (3) pH and specific conductance of precipitation vary significantly within small distances.

Xylan - A potential contaminant for lunar samples and Antarctic meteorites

NASA Astrophysics Data System (ADS)

Wright, I. P.; Russell, S. S.; Boyd, S. R.; Meyer, C.; Pillinger, C. T.

The possibility that lunar samples have been contaminated by the proprietary lubricant paint known as Xylan, which has been applied to screw threads in dry-N sample processing cabinets at NASA JSC, is considered. From a sample analysis using sealed-tube and stepped combustion, it is argued that the unexpectedly high concentration of organic materials found in EET A79001 is not due to Xylan contamination. It is considered unlikely that previous C and N analyses of lunar samples have been affected by the introduction of Xylan.

10 CFR Appendix B to Subpart F of... - Sampling Plan For Enforcement Testing

Code of Federal Regulations, 2010 CFR

2010-01-01

... sample as follows: ER18MR98.010 where (x 1) is the measured energy efficiency, energy or water (in the...-tailed probability level and a sample size of n 1. Step 6(a). For an Energy Efficiency Standard, compare... an Energy Efficiency Standard, determine the second sample size (n 2) as follows: ER18MR98.015 where...

Endogenous levels of nitrites and nitrates in wide consumption foodstuffs: Results of five years of official controls and monitoring.

PubMed

Iammarino, Marco; Di Taranto, Aurelia; Cristino, Marianna

2013-10-15

The massive introduction of nitrogen fertilisers, necessary to maximise the global food production, has brought about an increase of the residual amounts of nitrites and nitrates in the products. Notoriously, these compounds may exercise toxic effects. In this work the results obtained from 5years of official controls and monitoring focused on tracing quantifiable amounts of nitrites and nitrates in 1785 samples of meat, dairy, fish products and leafy vegetables are reported. A widespread presence of nitrates at low concentrations in foodstuffs was verified. High concentrations of nitrates were registered in some leafy vegetables and mussels samples, while high nitrites concentrations were registered in some spinach samples. The results confirmed the necessity to develop most controls and suggest the introduction of new legal limits related to some combinations contaminant/matrix. Such new limits may fill legislative gaps that may cause wrong interpretations of the results obtained during official controls. Copyright © 2012 Elsevier Ltd. All rights reserved.

Sterilization Efficiency of Spore forming Bacteria in Powdery Food by Atmospheric Pressure Plasmas Sterilizer

NASA Astrophysics Data System (ADS)

Nagata, Masayoshi; Tanaka, Masashi; Kikuchi, Yusuke

2015-09-01

To provide food sterilization method capable of killing highly heat resistant spore forming bacteria, we have studied effects of plasma treatment method at atmospheric pressure in order to develop a new high speed plasma sterilization apparatus with a low cost and a high efficiency. It is also difficult even for the plasma treatment to sterilize powdery food including spices such as soybean, basil and turmeric. This paper describes that an introduction of mechanical rotation of a treatment space increases the efficiency so that perfect inactivation of spore forming bacteria in these materials by a short treatment time has been demonstrated in our experiments. We also will discuss the sterilization mechanism by dielectric barrier discharge.

Extractive electrospray ionization mass spectrometry toward in situ analysis without sample pretreatment.

PubMed

Li, Ming; Hu, Bin; Li, Jianqiang; Chen, Rong; Zhang, Xie; Chen, Huanwen

2009-09-15

A homemade novel nanoextractive electrospray ionization (nanoEESI) source has been characterized for in situ mass spectrometric analysis of ambient samples without sample pretreatment. The primary ions generated using a nanospray emitter interact with the neutral sample plume created by manually nebulizing liquid samples, allowing production of the analyte ions in the spatial cross section of the nanoEESI source. The performance of nanoEESI is experimentally investigated by coupling the nanoEESI source to a commercial LTQ mass spectrometer for rapid analysis of various ambient samples using positive/negative ion detection modes. Compounds of interest in actual samples such as aerosol drug preparations, beverages, milk suspensions, farmland water, and groundwater were unambiguously detected using tandem nanoEESI ion trap mass spectrometry. The limit of detection was low picogram per milliliter levels for the compounds tested. Acceptable relative standard deviation (RSD) values (5-10%) were obtained for direct measurement of analytes in complex matrixes, providing linear dynamic signal responses using manual sample introduction. A single sample analysis was completed within 1.2 s. Requiring no sheath gas for either primary ion production or neutral sample introduction, the nanoEESI has advantages including readiness for miniaturization and integration, simple maintenance, easy operation, and low cost. The experimental data demonstrate that the nanoEESI is a promising tool for high-throughput, sensitive, quantitative, in situ analysis of ambient complex samples, showing potential applications for in situ analysis in multiple disciplines including but not limited to pharmaceutical analysis, food quality control, pesticides residue detection, and homeland security.

Rapid sample classification using an open port sampling interface coupled with liquid introduction atmospheric pressure ionization mass spectrometry

DOE PAGES

Van Berkel, Gary J.; Kertesz, Vilmos

2016-11-15

An “Open Access”-like mass spectrometric platform to fully utilize the simplicity of the manual open port sampling interface for rapid characterization of unprocessed samples by liquid introduction atmospheric pressure ionization mass spectrometry has been lacking. The in-house developed integrated software with a simple, small and relatively low-cost mass spectrometry system introduced here fills this void. Software was developed to operate the mass spectrometer, to collect and process mass spectrometric data files, to build a database and to classify samples using such a database. These tasks were accomplished via the vendorprovided software libraries. Sample classification based on spectral comparison utilized themore » spectral contrast angle method. As a result, using the developed software platform near real-time sample classification is exemplified using a series of commercially available blue ink rollerball pens and vegetable oils. In the case of the inks, full scan positive and negative ion ESI mass spectra were both used for database generation and sample classification. For the vegetable oils, full scan positive ion mode APCI mass spectra were recorded. The overall accuracy of the employed spectral contrast angle statistical model was 95.3% and 98% in case of the inks and oils, respectively, using leave-one-out cross-validation. In conclusion, this work illustrates that an open port sampling interface/mass spectrometer combination, with appropriate instrument control and data processing software, is a viable direct liquid extraction sampling and analysis system suitable for the non-expert user and near real-time sample classification via database matching.« less

Rapid sample classification using an open port sampling interface coupled with liquid introduction atmospheric pressure ionization mass spectrometry

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

Van Berkel, Gary J.; Kertesz, Vilmos

An “Open Access”-like mass spectrometric platform to fully utilize the simplicity of the manual open port sampling interface for rapid characterization of unprocessed samples by liquid introduction atmospheric pressure ionization mass spectrometry has been lacking. The in-house developed integrated software with a simple, small and relatively low-cost mass spectrometry system introduced here fills this void. Software was developed to operate the mass spectrometer, to collect and process mass spectrometric data files, to build a database and to classify samples using such a database. These tasks were accomplished via the vendorprovided software libraries. Sample classification based on spectral comparison utilized themore » spectral contrast angle method. As a result, using the developed software platform near real-time sample classification is exemplified using a series of commercially available blue ink rollerball pens and vegetable oils. In the case of the inks, full scan positive and negative ion ESI mass spectra were both used for database generation and sample classification. For the vegetable oils, full scan positive ion mode APCI mass spectra were recorded. The overall accuracy of the employed spectral contrast angle statistical model was 95.3% and 98% in case of the inks and oils, respectively, using leave-one-out cross-validation. In conclusion, this work illustrates that an open port sampling interface/mass spectrometer combination, with appropriate instrument control and data processing software, is a viable direct liquid extraction sampling and analysis system suitable for the non-expert user and near real-time sample classification via database matching.« less

Family and infant characteristics associated with timing of core and non-core food introduction in early childhood

PubMed Central

Schrempft, Stephanie; van Jaarsveld, Cornelia H.M.; Fisher, Abigail; Wardle, Jane

2013-01-01

Objective To identify family and infant characteristics associated with timing of introduction of two food types: core foods (nutrient-dense) and non-core foods (nutrient-poor) in a population-based sample of mothers and infants. Method Participants were 1861 mothers and infants from the Gemini twin birth cohort (one child per family). Family and infant characteristics were assessed when the infants were around 8 months old. Timing of introducing core and non-core foods was assessed at 8 and 15 months. As the distributions of timing were skewed, three similar-sized groups were created for each food type: earlier (core: 1–4 months; non-core: 3–8 months), average (core: 5 months; non-core: 9–10 months), and later introduction (core: 6–12 months; non-core: 11–18 months). Ordinal logistic regression was used to examine predictors of core and non-core food introduction, with bootstrapping to test for differences between the core and non-core models. Results Younger maternal age, lower education level, and higher maternal BMI were associated with earlier core and non-core food introduction. Not breastfeeding for at least 3 months and higher birth weight were specifically associated with earlier introduction of core foods. Having older children was specifically associated with earlier introduction of non-core foods. Conclusion There are similarities and differences in the characteristics associated with earlier introduction of core and non-core foods. Successful interventions may require a combination of approaches to target both food types. PMID:23486509

Time-dependent importance sampling in semiclassical initial value representation calculations for time correlation functions.

PubMed

Tao, Guohua; Miller, William H

2011-07-14

An efficient time-dependent importance sampling method is developed for the Monte Carlo calculation of time correlation functions via the initial value representation (IVR) of semiclassical (SC) theory. A prefactor-free time-dependent sampling function weights the importance of a trajectory based on the magnitude of its contribution to the time correlation function, and global trial moves are used to facilitate the efficient sampling the phase space of initial conditions. The method can be generally applied to sampling rare events efficiently while avoiding being trapped in a local region of the phase space. Results presented in the paper for two system-bath models demonstrate the efficiency of this new importance sampling method for full SC-IVR calculations.

Impact of Introduction of Blended Learning in Gross Anatomy on Student Outcomes

ERIC Educational Resources Information Center

Green, Rodney A.; Whitburn, Laura Y.

2016-01-01

Blended learning has become increasingly common, in a variety of disciplines, to take advantage of new technology and potentially increase the efficiency and flexibility of delivery. This study aimed to describe blended delivery of a gross anatomy course and to evaluate the effectiveness of the delivery in terms of student outcomes. A gross…

Use of Agrobacterium rhizogenes strain 18r12v and paromomycin selection for transformation of Brachypodium distachyon and Brachypodium sylvaticum

USDA-ARS?s Scientific Manuscript database

The genetic transformation of monocot grasses is a resource intensive process, the quality and efficiency of which is dependent in part upon the method of DNA introduction, as well as the ability to effectively separate transformed from wildtype tissue. Agrobacterium-mediated transformation of Brac...

Positive Peer Group Interventions: An Alternative to Individualized Interventions for Promoting Prosocial Behavior in Potentially Disaffected Youth

ERIC Educational Resources Information Center

Mclouglin, Caven S.

2009-01-01

Introduction: Most approaches to reducing the socially inappropriate behavior of adolescents target the individual rather than a group. Evidence suggests greater efficiency and longlasting effects may be achieved when groups of peers work together to make meaningful contributions to their communities through service learning projects. In the…

Introduction to session on materials and structures

NASA Technical Reports Server (NTRS)

Vosteen, L. F.

1978-01-01

A review was given of the development of composites for aircraft. Supporting base technology and the Aircraft Energy Efficiency Composites Program are included. Specific topics discussed include: (1) environmental effects on materials; (2) material quality and chemical characterization; (3) design and analysis methods; (4) structural durability; (5) impact sensitivity; (6) carbon fiber electrical effects; and (7) composite components.

Reflective Writing for a Better Understanding of Scientific Concepts in High School

ERIC Educational Resources Information Center

El-Helou, Joseph; Kalman, Calvin S.

2018-01-01

Science teachers can always benefit from efficient tools that help students to engage with the subject and understand it better without significantly adding to the teacher's workload nor requiring too much of class time to manage. Reflective writing is such a low-impact, high-return tool. What follows is an introduction to reflective writing, and…

Implementing Free Primary Education Policy in Malawi and Ghana: Equity and Efficiency Analysis

ERIC Educational Resources Information Center

Inoue, Kazuma; Oketch, Moses

2008-01-01

Malawi and Ghana are among the numerous Sub-Saharan Africa countries that have in recent years introduced Free Primary Education (FPE) policy as a means to realizing the 2015 Education for All and Millennium Development Goals international targets. The introduction of FPE policy is, however, a huge challenge for any national government that has…

Introduction to the Use of Computers in Libraries: A Textbook for the Non-Technical Student.

ERIC Educational Resources Information Center

Ogg, Harold C.

This book outlines computing and information science from the perspective of what librarians and educators need to do with computer technology and how it can help them perform their jobs more efficiently. It provides practical explanations and library applications for non-technical users of desktop computers and other library automation tools.…

Report on the Payroll System. MORE: Management Operations Review & Evaluation.

ERIC Educational Resources Information Center

Doody, Robert J.; And Others

Designed to improve the long-term operational efficiency of the Montgomery County, Maryland, Public Schools (MCPS) payroll system, this study begins with an executive summary, including a set of recommendations and a chapter-by-chapter synopsis. Following an introduction to the study and a general description of the payroll system in chapters 1…

Organizing. MAS-108. Waste Isolation Division (WID). Management and Supervisor Training (MAST) Program.

ERIC Educational Resources Information Center

Westinghouse Electric Corp., Carlsbad, NM.

This module is part of a set of management and supervisor training (MAST) materials developed by the Department of Energy for the Waste Isolation Division. Its stated purpose is to enable trainees to organize work activities efficiently and effectively. The first section of the module is an introduction that includes a terminal objective and…

Machine and Woodworking Tool Safety. Module SH-24. Safety and Health.

ERIC Educational Resources Information Center

Center for Occupational Research and Development, Inc., Waco, TX.

This student module on machine and woodworking tool safety is one of 50 modules concerned with job safety and health. This module discusses specific practices and precautions concerned with the efficient operation and use of most machine and woodworking tools in use today. Following the introduction, 13 objectives (each keyed to a page in the…

Purchasing and Accounting. MAS-116. Waste Isolation Division (WID). Management and Supervisor Training (MAST) Program.

ERIC Educational Resources Information Center

Westinghouse Electric Corp., Carlsbad, NM.

This learning module, which is part of a management and supervisor training program for managers and supervisors employed at the Department of Energy's Waste Isolation Division, is designed to prepare trainees to perform purchasing and accounting tasks efficiently and effectively. The first section is an introduction to the module. The next three…

Market Accountability in Schools: Policy Reforms in England, Germany, France and Italy

ERIC Educational Resources Information Center

Mattei, Paola

2012-01-01

This article concentrates on the policy reforms of schools in England, Germany, France and Italy, from 1988 to 2009, with a focus on the introduction of market accountability. Pressing demands for organisational change in schools, shaped by the objectives of "efficiency" and competition, which were introduced in England in the 1980s,…

Predicting Academic Success and Psychological Wellness in a Sample of Canadian Undergraduate Students

ERIC Educational Resources Information Center

Chow, Henry P. H.

2010-01-01

Introduction: University students need to cope with a complex new life role and to achieve academic success. This article explores the academic performance and psychological well-being among university students in a western Canadian city. Method: Using a convenience sample, a total of 501 undergraduate students in Regina, Saskatchewan took part in…

Cross-Cultural Comparison of Anxiety Symptoms in Colombian and Australian Children

ERIC Educational Resources Information Center

Amaya, Andrea Crane; Campbell, Marilyn

2010-01-01

Introduction: This cross-cultural study compared both the symptoms of anxiety and their severity in a community sample of children from Colombia and Australia. Method: The sample comprised 516 children (253 Australian children and 263 Colombian children), aged 8 to 12-years-old. The Spence Children's Anxiety Scale (SCAS) was used to measure both…

Introduction to Sample Size Choice for Confidence Intervals Based on "t" Statistics

ERIC Educational Resources Information Center

Liu, Xiaofeng Steven; Loudermilk, Brandon; Simpson, Thomas

2014-01-01

Sample size can be chosen to achieve a specified width in a confidence interval. The probability of obtaining a narrow width given that the confidence interval includes the population parameter is defined as the power of the confidence interval, a concept unfamiliar to many practitioners. This article shows how to utilize the Statistical Analysis…

Calibrating a Respirable Dust Sampling Device. Module 24. Vocational Education Training in Environmental Health Sciences.

ERIC Educational Resources Information Center

Consumer Dynamics Inc., Rockville, MD.

This module, one of 25 on vocational education training for careers in environmental health occupations, contains self-instructional materials on calibrating a respirable dust sampling device. Following guidelines for students and instructors and an introduction that explains what the student will learn, are three lessons: (1) naming each part of…

Estimation and modeling of electrofishing capture efficiency for fishes in wadeable warmwater streams

USGS Publications Warehouse

Price, A.; Peterson, James T.

2010-01-01

Stream fish managers often use fish sample data to inform management decisions affecting fish populations. Fish sample data, however, can be biased by the same factors affecting fish populations. To minimize the effect of sample biases on decision making, biologists need information on the effectiveness of fish sampling methods. We evaluated single-pass backpack electrofishing and seining combined with electrofishing by following a dual-gear, mark–recapture approach in 61 blocknetted sample units within first- to third-order streams. We also estimated fish movement out of unblocked units during sampling. Capture efficiency and fish abundances were modeled for 50 fish species by use of conditional multinomial capture–recapture models. The best-approximating models indicated that capture efficiencies were generally low and differed among species groups based on family or genus. Efficiencies of single-pass electrofishing and seining combined with electrofishing were greatest for Catostomidae and lowest for Ictaluridae. Fish body length and stream habitat characteristics (mean cross-sectional area, wood density, mean current velocity, and turbidity) also were related to capture efficiency of both methods, but the effects differed among species groups. We estimated that, on average, 23% of fish left the unblocked sample units, but net movement varied among species. Our results suggest that (1) common warmwater stream fish sampling methods have low capture efficiency and (2) failure to adjust for incomplete capture may bias estimates of fish abundance. We suggest that managers minimize bias from incomplete capture by adjusting data for site- and species-specific capture efficiency and by choosing sampling gear that provide estimates with minimal bias and variance. Furthermore, if block nets are not used, we recommend that managers adjust the data based on unconditional capture efficiency.

Changing molecular epidemiology of rotavirus infection after introduction of monovalent rotavirus vaccination in Scotland.

PubMed

Mukhopadhya, Indrani; Murdoch, Heather; Berry, Susan; Hunt, Alison; Iturriza-Gomara, Miren; Smith-Palmer, Alison; Cameron, J Claire; Hold, Georgina L

2017-01-03

Rotaviruses (RV) are the leading cause of gastroenteritis in children less than five years of age worldwide. Rotarix®, a live attenuated monovalent vaccine containing a RV strain of G1P[8] specificity has been included in the childhood immunisation schedule from June 2013 in Scotland. This study aimed to characterise the prevalent RV strains in Scotland before and after the introduction of the RV vaccine. RV positive faecal samples from Scottish virology laboratories covering the years 2012-2015 were genotyped. Viral RNA was extracted from faecal suspensions. VP7 and VP4 gene specific primers were used for multiplex hemi-nested PCRs and sequencing. Mann-Whitney U test and Chi-square test were used for statistical comparison. There was a decrease in RV positive samples from the Scottish virology laboratories from 7409 samples in the pre-vaccination years (2009-2013) to 760 in 2014-2015, with an annual reduction of RV infections by 74.4% (RR-3.95; 95%-CI, 3.53-4.42, p<0.001). 362 samples from the pre-vaccination period and 278 samples from the post-vaccination were genotyped. There was a drop in prevalence of G1P[8] strains (72.1%, 95%-CI, 67.42-76.33 to 15%, 95%-CI, 11.38-19.79) after introduction of the vaccine. In the post-vaccination period G2P[4] was the dominant strain in Scotland (21.9%, 95%-CI, 17.48-27.17) with increase in G9P[8] (12.9%, 95%-CI, 9.50-7.41), G12P[8] (12.2%, 95%-CI, 8.89-16.60) and G3P[8] (11.9%, 95%-CI, 8.58-16.20) infections. Phylogenetic analysis of the VP7 and VP4 genes showed no major differences between the pre and post-vaccination G1P[8] strains. This laboratory based surveillance study shows significant reduction in reported RV cases and a shift in proportion from G1P[8] to G2P[4] strains after introduction of RV vaccination in Scotland. The genotyping data from a subset of the total reported RV cases will be used to ascertain cross protection against strains and identify vaccine induced RV strain shifts in the years to come. Copyright © 2016 Elsevier Ltd. All rights reserved.

One-step multiplex real-time RT-PCR assay for detecting and genotyping wild-type group A rotavirus strains and vaccine strains (Rotarix® and RotaTeq®) in stool samples.

PubMed

Gautam, Rashi; Mijatovic-Rustempasic, Slavica; Esona, Mathew D; Tam, Ka Ian; Quaye, Osbourne; Bowen, Michael D

2016-01-01

Background. Group A rotavirus (RVA) infection is the major cause of acute gastroenteritis (AGE) in young children worldwide. Introduction of two live-attenuated rotavirus vaccines, RotaTeq® and Rotarix®, has dramatically reduced RVA associated AGE and mortality in developed as well as in many developing countries. High-throughput methods are needed to genotype rotavirus wild-type strains and to identify vaccine strains in stool samples. Quantitative RT-PCR assays (qRT-PCR) offer several advantages including increased sensitivity, higher throughput, and faster turnaround time. Methods. In this study, a one-step multiplex qRT-PCR assay was developed to detect and genotype wild-type strains and vaccine (Rotarix® and RotaTeq®) rotavirus strains along with an internal processing control (Xeno or MS2 RNA). Real-time RT-PCR assays were designed for VP7 (G1, G2, G3, G4, G9, G12) and VP4 (P[4], P[6] and P[8]) genotypes. The multiplex qRT-PCR assay also included previously published NSP3 qRT-PCR for rotavirus detection and Rotarix® NSP2 and RotaTeq® VP6 qRT-PCRs for detection of Rotarix® and RotaTeq® vaccine strains respectively. The multiplex qRT-PCR assay was validated using 853 sequence confirmed stool samples and 24 lab cultured strains of different rotavirus genotypes. By using thermostable rTth polymerase enzyme, dsRNA denaturation, reverse transcription (RT) and amplification (PCR) steps were performed in single tube by uninterrupted thermocycling profile to reduce chances of sample cross contamination and for rapid generation of results. For quantification, standard curves were generated using dsRNA transcripts derived from RVA gene segments. Results. The VP7 qRT-PCRs exhibited 98.8-100% sensitivity, 99.7-100% specificity, 85-95% efficiency and a limit of detection of 4-60 copies per singleplex reaction. The VP7 qRT-PCRs exhibited 81-92% efficiency and limit of detection of 150-600 copies in multiplex reactions. The VP4 qRT-PCRs exhibited 98.8-100% sensitivity, 100% specificity, 86-89% efficiency and a limit of detection of 12-400 copies per singleplex reactions. The VP4 qRT-PCRs exhibited 82-90% efficiency and limit of detection of 120-4000 copies in multiplex reaction. Discussion. The one-step multiplex qRT-PCR assay will facilitate high-throughput rotavirus genotype characterization for monitoring circulating rotavirus wild-type strains causing rotavirus infections, determining the frequency of Rotarix® and RotaTeq® vaccine strains and vaccine-derived reassortants associated with AGE, and help to identify novel rotavirus strains derived by reassortment between vaccine and wild-type strains.

One-step multiplex real-time RT-PCR assay for detecting and genotyping wild-type group A rotavirus strains and vaccine strains (Rotarix® and RotaTeq®) in stool samples

PubMed Central

Mijatovic-Rustempasic, Slavica; Esona, Mathew D.; Tam, Ka Ian; Quaye, Osbourne; Bowen, Michael D.

2016-01-01

Background. Group A rotavirus (RVA) infection is the major cause of acute gastroenteritis (AGE) in young children worldwide. Introduction of two live-attenuated rotavirus vaccines, RotaTeq® and Rotarix®, has dramatically reduced RVA associated AGE and mortality in developed as well as in many developing countries. High-throughput methods are needed to genotype rotavirus wild-type strains and to identify vaccine strains in stool samples. Quantitative RT-PCR assays (qRT-PCR) offer several advantages including increased sensitivity, higher throughput, and faster turnaround time. Methods. In this study, a one-step multiplex qRT-PCR assay was developed to detect and genotype wild-type strains and vaccine (Rotarix® and RotaTeq®) rotavirus strains along with an internal processing control (Xeno or MS2 RNA). Real-time RT-PCR assays were designed for VP7 (G1, G2, G3, G4, G9, G12) and VP4 (P[4], P[6] and P[8]) genotypes. The multiplex qRT-PCR assay also included previously published NSP3 qRT-PCR for rotavirus detection and Rotarix® NSP2 and RotaTeq® VP6 qRT-PCRs for detection of Rotarix® and RotaTeq® vaccine strains respectively. The multiplex qRT-PCR assay was validated using 853 sequence confirmed stool samples and 24 lab cultured strains of different rotavirus genotypes. By using thermostable rTth polymerase enzyme, dsRNA denaturation, reverse transcription (RT) and amplification (PCR) steps were performed in single tube by uninterrupted thermocycling profile to reduce chances of sample cross contamination and for rapid generation of results. For quantification, standard curves were generated using dsRNA transcripts derived from RVA gene segments. Results. The VP7 qRT-PCRs exhibited 98.8–100% sensitivity, 99.7–100% specificity, 85–95% efficiency and a limit of detection of 4–60 copies per singleplex reaction. The VP7 qRT-PCRs exhibited 81–92% efficiency and limit of detection of 150–600 copies in multiplex reactions. The VP4 qRT-PCRs exhibited 98.8–100% sensitivity, 100% specificity, 86–89% efficiency and a limit of detection of 12–400 copies per singleplex reactions. The VP4 qRT-PCRs exhibited 82–90% efficiency and limit of detection of 120–4000 copies in multiplex reaction. Discussion. The one-step multiplex qRT-PCR assay will facilitate high-throughput rotavirus genotype characterization for monitoring circulating rotavirus wild-type strains causing rotavirus infections, determining the frequency of Rotarix® and RotaTeq® vaccine strains and vaccine-derived reassortants associated with AGE, and help to identify novel rotavirus strains derived by reassortment between vaccine and wild-type strains. PMID:26839745

TBDPS and Br-TBDPS Protecting Groups as Efficient Aryl Group Donors in Pd-Catalyzed Arylation of Phenols and Anilines

PubMed Central

Huang, Chunhui; Gevorgyan, Vladimir

2009-01-01

It was shown that the TBDPS protecting group can serve as an efficient phenyl group donor for o-bromophenols via the Pd-catalyzed C—H arylation, followed by a routine TBAF deprotection of the forming silacycles. Employment of the newly designed Br-TBDPS protecting group in the same sequence allows for a facile introduction of a phenyl group in the ortho-position of phenols and anilines. Alternatively, switching desilylation to oxidation at the last step allows converting the forming silacycles into valuable ortho-biphenols. PMID:19722665

External quantum efficiency enhancement by photon recycling with backscatter evasion.

PubMed

Nagano, Koji; Perreca, Antonio; Arai, Koji; Adhikari, Rana X

2018-05-01

The nonunity quantum efficiency (QE) in photodiodes (PD) causes deterioration of signal quality in quantum optical experiments due to photocurrent loss as well as the introduction of vacuum fluctuations into the measurement. In this paper, we report that the external QE enhancement of a PD was demonstrated by recycling the reflected photons. The external QE for an InGaAs PD was increased by 0.01-0.06 from 0.86-0.92 over a wide range of incident angles. Moreover, we confirmed that this technique does not increase backscattered light when the recycled beam is properly misaligned.

Improvements of phosphorescent white OLEDs performance for lighting application.

PubMed

Lee, Jonghee; Chu, Hye Yong; Lee, Jeong-Ik; Song, Ki-Im; Lee, Su Jin

2008-10-01

We developed white OLED device with high power efficiency, in which blue and orange phosphorescent emitters were used. By introduction of multi-functional interlayer which has partial doping of orange dopant inside EBL, we report WOLEDs with peak external efficiencies up to (14.1% EQE, 31.3 Im/W) without light out-coupling technique. At 1000 cd/m2, the performance achieved was 11.9% EQE, 18.7 Im/W with CIE = (0.39, 0.44). We also found that WOLED performances are related with doping ratio of the orange dopant that was inserted inside EBL.

Improving care and efficiency: appointment times in a haemodialysis unit.

PubMed

Lunts, P

2002-01-01

Shortage of nurses and dialysis spaces and the desire to improve patient care are the two main driving forces in the dialysis field today. This paper suggests that these issues can be addressed by organisational change. We describe a simple, dramatically effective but rarely used example - the effect on a haemodialysis unit of the introduction of patient appointment times. This paper will demonstrate that appointment times can be highly effective in reducing waiting times for patients and in utilizing staff and resources more efficiently, as long as there is commitment from key staff to implement and maintain them effectively

Kolkata Paise Restaurant Problem: An Introduction

NASA Astrophysics Data System (ADS)

Ghosh, Asim; Biswas, Soumyajyoti; Chatterjee, Arnab; Chakrabarti, Anindya Sundar; Naskar, Tapan; Mitra, Manipushpak; Chakrabarti, Bikas K.

We discuss several stochastic optimization strategies in games with many players having large number of choices (Kolkata Paise Restaurant Problem) and two choices (minority game problem). It is seen that a stochastic crowd avoiding strategy gives very efficient utilization in KPR problem. A slightly modified strategy in the minority game problem gives full utilization but the dynamics stops after reaching full efficiency, thereby making the utilization helpful for only about half of the population (those in minority). We further discuss the ways in which the dynamics may be continued and the utilization becomes effective for all the agents keeping fluctuation arbitrarily small.

Effects of surface diffusion on high temperature selective emitters

DOE PAGES

Peykov, Daniel; Yeng, Yi Xiang; Celanovic, Ivan; ...

2015-01-01

Using morphological and optical simulations of 1D tantalum photonic crystals at 1200K, surface diffusion was determined to gradually reduce the efficiency of selective emitters. This was attributed to shifting resonance peaks and declining emissivity caused by changes to the cavity dimensions and the aperture width. Decreasing the structure’s curvature through larger periods and smaller cavity widths, as well as generating smoother transitions in curvature through the introduction of rounded cavities, was found to alleviate this degradation. An optimized structure, that shows both high efficiency selective emissivity and resistance to surface diffusion, was presented.

Introduction of Nano-seconds Pulsed Discharge Plasma and its Applications

NASA Astrophysics Data System (ADS)

Namihira, Takao; Wang, Douyan; Matsumoto, Takao; Okada, Sho; Akiyama, Hidenori

During the decades, the developments of high power semiconductor switch, magnetic core and etc have allowed us to manufacture the pulsed power source having higher energy transfer efficiency. As the results, the pulsed discharge has been recognized as one of the promised non-thermal plasma to practical use. In this paper, a generation process, electron energy, impedance and a temperature of the pulsed discharge plasma would be explained. In addition, a nano-seconds pulsed discharge plasma would be introduced as the non-thermal plasma processing giving us the highest energy efficiency and be demonstrated it.

System implications of large radiometric array antennas

NASA Technical Reports Server (NTRS)

Levis, C. A.; Lin, H. C.

1976-01-01

Current radiometric earth and atmospheric sensing systems in the centimeter wavelength range generally employ a directive antenna connected through a single terminal pair to a Dicke receiver. It is shown that this approach does not lend itself to systems with greatly increased spatial resolution. Signal to noise considerations relating to antenna efficiency force the introduction of active elements at the subarray level; thus, if Dicke switching is to be used, it must be distributed throughout the system. Some possible approaches are suggested. The introduction of active elements at the subarray level is found to ease the design constraints on time delay elements, necessary for bandwidth, and on multiple beam generation, required in order to achieve sufficient integration time with high resolution.

Introduction of a dermatophyte polymerase chain reaction assay to the diagnostic mycology service in Scotland.

PubMed

Alexander, C L; Shankland, G S; Carman, W; Williams, C

2011-05-01

Dermatophytes are the major cause of superficial mycoses in samples submitted to Clinical Mycology, Glasgow. The most prevalent species is Trichophyton rubrum as identified classically by microscopy and culture. Recent advances in polymerase chain reaction (PCR) technology were examined for the feasibility of introducing a T. rubrum real-time PCR assay into a routine diagnostic service. To improve the diagnostic mycology service by the introduction of a real-time PCR test for T. rubrum. The DNA from 4972 nail and skin samples was obtained using the Qiagen QIAsymphony automated extractor. This DNA was subjected to real-time PCR using T. rubrum-specific primers and a probe. During phase 1 of the study, 862 samples were analysed; 446 of 470 specimens that grew T. rubrum were detected by PCR. Out of 4110 samples analysed during phase 2, 753 T. rubrum infections were diagnosed and reported within 72 h. A total of 3357 samples were negative for a fungal infection by PCR and microscopy; these were also reported within 72 h. A vast reduction in the turnaround times can be achieved using this technique as opposed to classical methods. Samples which are PCR negative but microscopy positive are still subjected to culture. Screening samples for their suitability for PCR prior to processing eliminates the application of PCR for T. rubrum on inappropriate samples such those from the scalp or pityriasis versicolor. © 2011 The Authors. BJD © 2011 British Association of Dermatologists.

A novel process for introducing a new intraoperative program: a multidisciplinary paradigm for mitigating hazards and improving patient safety.

PubMed

Rodriguez-Paz, Jose M; Mark, Lynette J; Herzer, Kurt R; Michelson, James D; Grogan, Kelly L; Herman, Joseph; Hunt, David; Wardlow, Linda; Armour, Elwood P; Pronovost, Peter J

2009-01-01

Since the Institute of Medicine's report, To Err is Human, was published, numerous interventions have been designed and implemented to correct the defects that lead to medical errors and adverse events; however, most efforts were largely reactive. Safety, communication, team performance, and efficiency are areas of care that attract a great deal of attention, especially regarding the introduction of new technologies, techniques, and procedures. We describe a multidisciplinary process that was implemented at our hospital to identify and mitigate hazards before the introduction of a new technique: high-dose-rate intraoperative radiation therapy, (HDR-IORT). A multidisciplinary team of surgeons, anesthesiologists, radiation oncologists, physicists, nurses, hospital risk managers, and equipment specialists used a structured process that included in situ clinical simulation to uncover concerns among care providers and to prospectively identify and mitigate defects for patients who would undergo surgery using the HDR-IORT technique. We identified and corrected 20 defects in the simulated patient care process before application to actual patients. Subsequently, eight patients underwent surgery using the HDR-IORT technique with no recurrence of simulation-identified or unanticipated defects. Multiple benefits were derived from the use of this systematic process to introduce the HDR-IORT technique; namely, the safety and efficiency of care for this select patient population was optimized, and this process mitigated harmful or adverse events before the inclusion of actual patients. Further work is needed, but the process outlined in this paper can be universally applied to the introduction of any new technologies, treatments, or procedures.

Decreased Risk of Preeclampsia After the Introduction of Universal Voucher Scheme for Antenatal Care and Birth Services in the Republic of Korea.

PubMed

Choe, Seung-Ah; Min, Hye Sook; Cho, Sung-Il

2017-01-01

Objectives A number of interventions to reduce disparities in maternal health have been introduced and implemented without concrete evidence to support them. In Korea, a universal voucher scheme for antenatal care and birth services was initiated in December 2008 to improve Korea's fertility rate. This study explores the risk of preeclampsia after the introduction of a universal voucher scheme. Methods Population-based cohort data from the National Health Insurance Service-National Sample Cohort (NHIS-NSC) covering 2002-2013 were analysed. A generalized linear mixed model (GLMM) was used to estimate the relationship between the risk of preeclampsia and voucher scheme introduction. Results The annual age-adjusted incidence of preeclampsia showed no significant unidirectional change during the study period. In the GLMM analysis, the introduction of a voucher scheme was associated with a reduced risk of preeclampsia, controlling for potential confounding factors. The interaction between household income level and voucher scheme was not significant. Conclusions for Practice This finding suggests that the introduction of a voucher scheme for mothers is related to a reduced risk of preeclampsia even under universal health coverage.

Experimental Determination of the HPGe Spectrometer Efficiency Calibration Curves for Various Sample Geometry for Gamma Energy from 50 keV to 2000 keV

NASA Astrophysics Data System (ADS)

Saat, Ahmad; Hamzah, Zaini; Yusop, Mohammad Fariz; Zainal, Muhd Amiruddin

2010-07-01

Detection efficiency of a gamma-ray spectrometry system is dependent upon among others, energy, sample and detector geometry, volume and density of the samples. In the present study the efficiency calibration curves of newly acquired (August 2008) HPGe gamma-ray spectrometry system was carried out for four sample container geometries, namely Marinelli beaker, disc, cylindrical beaker and vial, normally used for activity determination of gamma-ray from environmental samples. Calibration standards were prepared by using known amount of analytical grade uranium trioxide ore, homogenized in plain flour into the respective containers. The ore produces gamma-rays of energy ranging from 53 keV to 1001 keV. Analytical grade potassium chloride were prepared to determine detection efficiency of 1460 keV gamma-ray emitted by potassium isotope K-40. Plots of detection efficiency against gamma-ray energy for the four sample geometries were found to fit smoothly to a general form of ɛ = AΕa+BΕb, where ɛ is efficiency, Ε is energy in keV, A, B, a and b are constants that are dependent on the sample geometries. All calibration curves showed the presence of a "knee" at about 180 keV. Comparison between the four geometries showed that the efficiency of Marinelli beaker is higher than cylindrical beaker and vial, while cylindrical disk showed the lowest.

A quantitative risk assessment model to evaluate effective border control measures for rabies prevention.

PubMed

Weng, Hsin-Yi; Wu, Pei-I; Yang, Ping-Cheng; Tsai, Yi-Lun; Chang, Chao-Chin

2010-01-01

Border control is the primary method to prevent rabies emergence. This study developed a quantitative risk model incorporating stochastic processes to evaluate whether border control measures could efficiently prevent rabies introduction through importation of cats and dogs using Taiwan as an example. Both legal importation and illegal smuggling were investigated. The impacts of reduced quarantine and/or waiting period on the risk of rabies introduction were also evaluated. The results showed that Taiwan's current animal importation policy could effectively prevent rabies introduction through legal importation of cats and dogs. The median risk of a rabid animal to penetrate current border control measures and enter Taiwan was 5.33 x 10(-8) (95th percentile: 3.20 x 10(-7)). However, illegal smuggling may pose Taiwan to the great risk of rabies emergence. Reduction of quarantine and/or waiting period would affect the risk differently, depending on the applied assumptions, such as increased vaccination coverage, enforced custom checking, and/or change in number of legal importations. Although the changes in the estimated risk under the assumed alternatives were not substantial except for completely abolishing quarantine, the consequences of rabies introduction may yet be considered to be significant in a rabies-free area. Therefore, a comprehensive benefit-cost analysis needs to be conducted before recommending these alternative measures.

Comparison of Relative Bias, Precision, and Efficiency of Sampling Methods for Natural Enemies of Soybean Aphid (Hemiptera: Aphididae).

PubMed

Bannerman, J A; Costamagna, A C; McCornack, B P; Ragsdale, D W

2015-06-01

Generalist natural enemies play an important role in controlling soybean aphid, Aphis glycines (Hemiptera: Aphididae), in North America. Several sampling methods are used to monitor natural enemy populations in soybean, but there has been little work investigating their relative bias, precision, and efficiency. We compare five sampling methods: quadrats, whole-plant counts, sweep-netting, walking transects, and yellow sticky cards to determine the most practical methods for sampling the three most prominent species, which included Harmonia axyridis (Pallas), Coccinella septempunctata L. (Coleoptera: Coccinellidae), and Orius insidiosus (Say) (Hemiptera: Anthocoridae). We show an important time by sampling method interaction indicated by diverging community similarities within and between sampling methods as the growing season progressed. Similarly, correlations between sampling methods for the three most abundant species over multiple time periods indicated differences in relative bias between sampling methods and suggests that bias is not consistent throughout the growing season, particularly for sticky cards and whole-plant samples. Furthermore, we show that sticky cards produce strongly biased capture rates relative to the other four sampling methods. Precision and efficiency differed between sampling methods and sticky cards produced the most precise (but highly biased) results for adult natural enemies, while walking transects and whole-plant counts were the most efficient methods for detecting coccinellids and O. insidiosus, respectively. Based on bias, precision, and efficiency considerations, the most practical sampling methods for monitoring in soybean include walking transects for coccinellid detection and whole-plant counts for detection of small predators like O. insidiosus. Sweep-netting and quadrat samples are also useful for some applications, when efficiency is not paramount. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Wrinkled silica/titania nanoparticles with tunable interwrinkle distances for efficient utilization of photons in dye-sensitized solar cells.

PubMed

Kang, Jin Soo; Lim, Joohyun; Rho, Won-Yeop; Kim, Jin; Moon, Doo-Sik; Jeong, Juwon; Jung, Dongwook; Choi, Jung-Woo; Lee, Jin-Kyu; Sung, Yung-Eun

2016-08-04

Efficient light harvesting is essential for the realization of high energy conversion efficiency in dye-sensitized solar cells (DSCs). State-of-the-art mesoporous TiO2 photoanodes fall short for collection of long-wavelength visible light photons, and thus there have been efforts on introduction of scattering nanoparticles. Herein, we report the synthesis of wrinkled silica/titania nanoparticles with tunable interwrinkle distances as scattering materials for enhanced light harvesting in DSCs. These particles with more than 20 times larger specific surface area (>400 m(2)/g) compared to the spherical scattering particles (<20 m(2)/g) of the similar sizes gave rise to the dye-loading amounts, causing significant improvements in photocurrent density and efficiency. Moreover, dependence of spectral scattering properties of wrinkled particles on interwrinkle distances, which was originated from difference in overall refractive indices, was observed.

Problems of Technology of Energy-Saving Buildings and Their Impact on Energy Efficiency in Buildings

NASA Astrophysics Data System (ADS)

Kwasnowski, Pawel; Fedorczak-Cisak, Malgorzata; Knap, Katarzyna

2017-10-01

Introduction of EPBD in legislation of the EU member states caused that buildings must meet very stringent requirements of thermal protection and energy efficiency. On the basis of EPBD provisions, EU Member States introduce standard of NZEB (Nearly Zero-Energy Buildings). Such activities cause a need for new, innovative materials and technologies, and new approaches to design, construction and retrofitting of buildings. Indispensable is the precise coordination of the design of structure and technical installations of building, which may be provided in an integrated design process in the system BIM. Good coordination and cooperation of all contractors during the construction phase is also necessary. The article presents the problems and the new methodology for the design, construction and use of energy efficient buildings in terms of energy saving technologies, including discussion of the significant impact of the automation of technical installations on the building energy efficiency.

Country profile: Hungary

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

Not Available

1991-09-01

Country Profile: Hungary has been prepared as a background document for use by US Government agencies and US businesses interested in becoming involved with the new democracies of Eastern Europe as they pursue sustainable economic development. The focus of the Profile is on energy and highlights information on Hungary`s energy supply, demand, and utilization. It identifies patterns of energy usage in the important economic sectors, especially industry, and provides a preliminary assessment for opportunities to improve efficiencies in energy production, distribution and use by introducing more efficient technologies. The use of more efficient technologies would have the added benefit ofmore » reducing the environmental impact which, although is not the focus of the report, is an issue that effects energy choices. The Profile also presents considerable economic information, primarily in the context of how economic restructuring may affect energy supply, demand, and the introduction of more efficient technologies.« less

Country profile: Hungary

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

Not Available

1991-09-01

Country Profile: Hungary has been prepared as a background document for use by US Government agencies and US businesses interested in becoming involved with the new democracies of Eastern Europe as they pursue sustainable economic development. The focus of the Profile is on energy and highlights information on Hungary's energy supply, demand, and utilization. It identifies patterns of energy usage in the important economic sectors, especially industry, and provides a preliminary assessment for opportunities to improve efficiencies in energy production, distribution and use by introducing more efficient technologies. The use of more efficient technologies would have the added benefit ofmore » reducing the environmental impact which, although is not the focus of the report, is an issue that effects energy choices. The Profile also presents considerable economic information, primarily in the context of how economic restructuring may affect energy supply, demand, and the introduction of more efficient technologies.« less

Bayesian Processor of Output for Probabilistic Quantitative Precipitation Forecasting

NASA Astrophysics Data System (ADS)

Krzysztofowicz, R.; Maranzano, C. J.

2006-05-01

The Bayesian Processor of Output (BPO) is a new, theoretically-based technique for probabilistic forecasting of weather variates. It processes output from a numerical weather prediction (NWP) model and optimally fuses it with climatic data in order to quantify uncertainty about a predictand. The BPO is being tested by producing Probabilistic Quantitative Precipitation Forecasts (PQPFs) for a set of climatically diverse stations in the contiguous U.S. For each station, the PQPFs are produced for the same 6-h, 12-h, and 24-h periods up to 84- h ahead for which operational forecasts are produced by the AVN-MOS (Model Output Statistics technique applied to output fields from the Global Spectral Model run under the code name AVN). The inputs into the BPO are estimated as follows. The prior distribution is estimated from a (relatively long) climatic sample of the predictand; this sample is retrieved from the archives of the National Climatic Data Center. The family of the likelihood functions is estimated from a (relatively short) joint sample of the predictor vector and the predictand; this sample is retrieved from the same archive that the Meteorological Development Laboratory of the National Weather Service utilized to develop the AVN-MOS system. This talk gives a tutorial introduction to the principles and procedures behind the BPO, and highlights some results from the testing: a numerical example of the estimation of the BPO, and a comparative verification of the BPO forecasts and the MOS forecasts. It concludes with a list of demonstrated attributes of the BPO (vis- à-vis the MOS): more parsimonious definitions of predictors, more efficient extraction of predictive information, better representation of the distribution function of predictand, and equal or better performance (in terms of calibration and informativeness).

Comparison of laser and power bleaching techniques in tooth color change.

PubMed

Fekrazad, Reza; Alimazandarani, Shervin; Kalhori, Katayoun Am; Assadian, Hadi; Mirmohammadi, Seyed-Mahdi

2017-04-01

Laser-assisted bleaching uses laser beam to accelerate release of free radicals within the bleaching gel to decrease time of whitening procedure. The aim of this study was to compare the efficacy of power bleaching using Opalescence Xtra Boost® and laser bleaching technique using LaserSmile gel and diode laser as an activator in their tooth whitening capacity. Student t test showed that the laser bleaching group significantly outperformed the power bleaching group in changing ∆E ( p =0.977). Similarly, while comparing the groups in changing ∆L, the laser bleaching group indicated significantly superior results ( p =0.953). Statistical data from student t test while comparing the groups in changing the parameter of yellowness indicated that samples in laser bleaching group underwent a more significant reduction than power-bleached samples ( p =0.85). Correspondingly, changes in whiteness were statistically tested through student t test, showing that laser bleaching technique increased whiteness of the samples significantly more than those treated by power bleaching ( p =0.965). The digital color evaluation data was in accordance with spectrophotometry and showed that laser bleaching outperformed power bleaching technique. Both techniques were able to increase whiteness and decrease yellowness ratio of the samples. ΔE decrease for laser bleaching and power bleaching groups were 3.05 and 1.67, respectively. Tooth color change in laser bleaching group was 1.88 times more than that of power bleaching group ( p <0.001). It could be concluded that under the conditions of this study, both laser-assisted and power bleaching techniques were capable of altering tooth color change, but laser bleaching was deemed a more efficient technique in this regard. Key words: Laser, power bleaching, tooth color introduction.

Detection of Invasive Mosquito Vectors Using Environmental DNA (eDNA) from Water Samples

PubMed Central

Schneider, Judith; Valentini, Alice; Dejean, Tony; Montarsi, Fabrizio; Taberlet, Pierre

2016-01-01

Repeated introductions and spread of invasive mosquito species (IMS) have been recorded on a large scale these last decades worldwide. In this context, members of the mosquito genus Aedes can present serious risks to public health as they have or may develop vector competence for various viral diseases. While the Tiger mosquito (Aedes albopictus) is a well-known vector for e.g. dengue and chikungunya viruses, the Asian bush mosquito (Ae. j. japonicus) and Ae. koreicus have shown vector competence in the field and the laboratory for a number of viruses including dengue, West Nile fever and Japanese encephalitis. Early detection and identification is therefore crucial for successful eradication or control strategies. Traditional specific identification and monitoring of different and/or cryptic life stages of the invasive Aedes species based on morphological grounds may lead to misidentifications, and are problematic when extensive surveillance is needed. In this study, we developed, tested and applied an environmental DNA (eDNA) approach for the detection of three IMS, based on water samples collected in the field in several European countries. We compared real-time quantitative PCR (qPCR) assays specific for these three species and an eDNA metabarcoding approach with traditional sampling, and discussed the advantages and limitations of these methods. Detection probabilities for eDNA-based approaches were in most of the specific comparisons higher than for traditional survey and the results were congruent between both molecular methods, confirming the reliability and efficiency of alternative eDNA-based techniques for the early and unambiguous detection and surveillance of invasive mosquito vectors. The ease of water sampling procedures in the eDNA approach tested here allows the development of large-scale monitoring and surveillance programs of IMS, especially using citizen science projects. PMID:27626642

Method and apparatus for noble gas atom detection with isotopic selectivity

DOEpatents

Hurst, G. Samuel; Payne, Marvin G.; Chen, Chung-Hsuan; Parks, James E.

1984-01-01

Apparatus and methods of operation are described for determining, with isotopic selectivity, the number of noble gas atoms in a sample. The analysis is conducted within an evacuated chamber which can be isolated by a valve from a vacuum pumping system capable of producing a pressure of 10.sup.-8 Torr. Provision is made to pass pulses of laser beams through the chamber, these pulses having wavelengths appropriate for the resonance ionization of atoms of the noble gas under analysis. A mass filter within the chamber selects ions of a specific isotope of the noble gas, and means are provided to accelerate these selected ions sufficiently for implantation into a target. Specific types of targets are discussed. An electron measuring device produces a signal relatable to the number of ions implanted into the target and thus to the number of atoms of the selected isotope of the noble gas removed from the gas sample. The measurement can be continued until a substantial fraction, or all, of the atoms in the sample have been counted. Furthermore, additional embodiments of the apparatus are described for bunching the atoms of a noble gas for more rapid analysis, and for changing the target for repetitive cycling of the gas in the chamber. The number of repetitions of the cyclic steps depend upon the concentration of the isotope of interest, the separative efficiency of the mass filter, etc. The cycles are continued until a desired selectivity is achieved. Also described are components and a method of operation for a pre-enrichment operation for use when an introduction of a total sample would elevate the pressure within the chamber to levels in excess of those for operation of the mass filter, specifically a quadrupole mass filter. Specific examples of three noble gas isotope analyses are described.

Detection of Invasive Mosquito Vectors Using Environmental DNA (eDNA) from Water Samples.

PubMed

Schneider, Judith; Valentini, Alice; Dejean, Tony; Montarsi, Fabrizio; Taberlet, Pierre; Glaizot, Olivier; Fumagalli, Luca

2016-01-01

Repeated introductions and spread of invasive mosquito species (IMS) have been recorded on a large scale these last decades worldwide. In this context, members of the mosquito genus Aedes can present serious risks to public health as they have or may develop vector competence for various viral diseases. While the Tiger mosquito (Aedes albopictus) is a well-known vector for e.g. dengue and chikungunya viruses, the Asian bush mosquito (Ae. j. japonicus) and Ae. koreicus have shown vector competence in the field and the laboratory for a number of viruses including dengue, West Nile fever and Japanese encephalitis. Early detection and identification is therefore crucial for successful eradication or control strategies. Traditional specific identification and monitoring of different and/or cryptic life stages of the invasive Aedes species based on morphological grounds may lead to misidentifications, and are problematic when extensive surveillance is needed. In this study, we developed, tested and applied an environmental DNA (eDNA) approach for the detection of three IMS, based on water samples collected in the field in several European countries. We compared real-time quantitative PCR (qPCR) assays specific for these three species and an eDNA metabarcoding approach with traditional sampling, and discussed the advantages and limitations of these methods. Detection probabilities for eDNA-based approaches were in most of the specific comparisons higher than for traditional survey and the results were congruent between both molecular methods, confirming the reliability and efficiency of alternative eDNA-based techniques for the early and unambiguous detection and surveillance of invasive mosquito vectors. The ease of water sampling procedures in the eDNA approach tested here allows the development of large-scale monitoring and surveillance programs of IMS, especially using citizen science projects.

A droplet digital PCR (ddPCR) assay to detect Helicoverpa armigera (Lepidoptera: Noctuidae) in bulk trap samples.

PubMed

Zink, Frida A; Tembrock, Luke R; Timm, Alicia E; Farris, Roxanne E; Perera, Omaththage P; Gilligan, Todd M

2017-01-01

Moths in the genus Helicoverpa are some of the most important agricultural pests in the world. Two species, H. armigera (Hübner) and H. zea (Boddie), cause the majority of damage to crops and millions of dollars are spent annually on control of these pests. The recent introduction of H. armigera into the New World has prompted extensive survey efforts for this species in the United States. Surveys are conducted using bucket traps baited with H. armigera pheromone, and, because the same pheromone compounds attract both species, these traps often capture large numbers of the native H. zea. Adult H. armigera and H. zea are very similar and can only be separated morphologically by minor differences in the genitalia. Thus, a time consuming genitalic dissection by a trained specialist is necessary to reliably identify either species, and every specimen must be dissected. Several molecular methods are available for differentiating and identifying H. armigera and H. zea, including two recently developed rapid protocols using real-time PCR. However, none of the published methods are capable of screening specimens in large batches. Here we detail a droplet digital PCR (ddPCR) assay that is capable of detecting a single H. armigera in a background of up to 999 H. zea. The assay has been tested using bulk extractions of 1,000 legs from actual trap samples and is effective even when using poor quality samples. This study provides an efficient, rapid, reproducible, and scalable method for processing H. armigera survey trap samples in the U.S. and demonstrates the potential for applying ddPCR technology to screen and diagnose invasive species.

Revealing the beneficial role of K in grain interiors, grain boundaries, and at the buffer interface for highly efficient CuInSe 2 solar cells

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

Muzzillo, Christopher P.; Poplawsky, Jonathan D.; Tong, Ho Ming

K incorporation within grain boundaries, grain interiors, and interfaces has been studied within CuInSe 2 solar cells to better understand the beneficial or detrimental role of K distribution among these regions in chalcopyrite–based solar cells. Solar cells have been fabricated with intentional K introduction into specific regions of the device including the CuInSe 2/CdS interface (CuInSe 2/KInSe 2/CdS) and the grain interiors (Cu 0.93K 0.07InSe 2/CdS). A control CuInSe 2/CdS device was also studied to separate effects of K originating from the soda–lime glass substrate from those of intentionally introduced K. The experiment was designed to understand K effects inmore » Cu(In,Ga)Se 2 solar cells while mitigating complications from multiple elements in the 3 + site. The distribution of all elements within these samples has been directly observed with sub–nm resolution via atom probe tomography. In addition, electron beam–induced current measurements have been performed to correlate the atom probe tomography compositional profiles to the nanoscale carrier collection properties. The experiments show that a large decrease in the Cu/In ratio at the CdS interface can be achieved by forming KInSe 2 at the absorber surface, which drastically improves the device efficiency. The results presented here show a direct link between K concentration, Cu depletion, and In accumulation, such that the Cu/In ratio significantly reduces with K incorporation. In conclusion, the findings help clarify the mechanism behind K–induced efficiency enhancement.« less

Revealing the beneficial role of K in grain interiors, grain boundaries, and at the buffer interface for highly efficient CuInSe 2 solar cells

DOE PAGES

Muzzillo, Christopher P.; Poplawsky, Jonathan D.; Tong, Ho Ming; ...

2018-06-06

K incorporation within grain boundaries, grain interiors, and interfaces has been studied within CuInSe 2 solar cells to better understand the beneficial or detrimental role of K distribution among these regions in chalcopyrite–based solar cells. Solar cells have been fabricated with intentional K introduction into specific regions of the device including the CuInSe 2/CdS interface (CuInSe 2/KInSe 2/CdS) and the grain interiors (Cu 0.93K 0.07InSe 2/CdS). A control CuInSe 2/CdS device was also studied to separate effects of K originating from the soda–lime glass substrate from those of intentionally introduced K. The experiment was designed to understand K effects inmore » Cu(In,Ga)Se 2 solar cells while mitigating complications from multiple elements in the 3 + site. The distribution of all elements within these samples has been directly observed with sub–nm resolution via atom probe tomography. In addition, electron beam–induced current measurements have been performed to correlate the atom probe tomography compositional profiles to the nanoscale carrier collection properties. The experiments show that a large decrease in the Cu/In ratio at the CdS interface can be achieved by forming KInSe 2 at the absorber surface, which drastically improves the device efficiency. The results presented here show a direct link between K concentration, Cu depletion, and In accumulation, such that the Cu/In ratio significantly reduces with K incorporation. In conclusion, the findings help clarify the mechanism behind K–induced efficiency enhancement.« less

Bromine isotope ratio measurements in seawater by multi-collector inductively coupled plasma-mass spectrometry with a conventional sample introduction system.

PubMed

de Gois, Jefferson S; Vallelonga, Paul; Spolaor, Andrea; Devulder, Veerle; Borges, Daniel L G; Vanhaecke, Frank

2016-01-01

A simple and accurate methodology for Br isotope ratio measurements in seawater by multi-collector inductively coupled plasma-mass spectrometry (MC-ICP-MS) with pneumatic nebulization for sample introduction was developed. The Br(+) signals could be measured interference-free at high mass resolution. Memory effects for Br were counteracted using 5 mmol L(-1) of NH4OH in sample, standard, and wash solutions. The major cation load of seawater was removed via cation exchange chromatography using Dowex 50WX8 resin. Subsequent Br preconcentration was accomplished via evaporation of the sample solution at 90 °C, which did not induce Br losses or isotope fractionation. Mass discrimination was corrected for by external correction using a Cl-matched standard measured in a sample-standard bracketing approach, although Sr, Ge, and Se were also tested as potential internal standards for internal correction for mass discrimination. The δ(81)Br (versus standard mean ocean bromide (SMOB)) values thus obtained for the NaBr isotopic reference material NIST SRM 977 and for IRMM BCR-403 seawater certified reference material are in agreement with literature values. For NIST SRM 977, the (81)Br/(79)Br ratio (0.97291) was determined with a precision ≤0.08‰ relative standard deviation (RSD).

I-Xe dating of aqueous alteration in the CI chondrite Orgueil: I. Magnetite and ferromagnetic separates

NASA Astrophysics Data System (ADS)

Pravdivtseva, O.; Krot, A. N.; Hohenberg, C. M.

2018-04-01

The I-Xe system was studied in a ferromagnetic sample separated from the Orgueil CI carbonaceous chondrite with a hand-held magnet and in two magnetite samples, one chemically separated before and the other one after neutron irradiation. This work was done in order to investigate the effects of chemical separation by LiCl and NaOH on the I-Xe system in magnetite. Our test demonstrated that the chemical separation of magnetite before irradiation using either LiCl or NaOH, or both, does not contaminate the sample with iodine and thus cannot lead to erroneous I-Xe ages due to introduction of uncorrelated 128∗Xe. The I-Xe ages of two Orgueil magnetite samples are mutually consistent within experimental uncertainties and, when normalized to an absolute time scale with the reevaluated Shallowater aubrite standard, place the onset of aqueous alteration on the CI parent body at 4564.3 ± 0.3 Ma, 2.9 ± 0.3 Ma after formation of the CV Ca-AI-rich inclusions (CAIs). The I-Xe age of the ferromagnetic Orgueil separate is 3.4 Ma younger, corresponding to a closure of the I-Xe system at 4560.9 ± 0.2 Ma. These and previously published I-Xe data for Orgueil (Hohenberg et al., 2000) indicate that aqueous alteration on the CI parent body lasted for at least 5 Ma. Although the two magnetite samples gave indistinguishable I-Xe ages, their temperature release profiles differed. One of the two Orgueil magnetites released less radiogenic Xe than the other, 80% of it corresponding to the low-temperature peak of the release profile, compared to only 6% in case of the second Orgueil magnetite sample. This could be due to the difference in iodine trapping efficiencies for magnetite grains of different morphologies. Alternatively, the magnetite grains with the lower radiogenic Xe concentrations may have formed at a later stage of alteration when iodine in an aqueous solution was depleted.

A Simulation Approach to Assessing Sampling Strategies for Insect Pests: An Example with the Balsam Gall Midge

PubMed Central

Carleton, R. Drew; Heard, Stephen B.; Silk, Peter J.

2013-01-01

Estimation of pest density is a basic requirement for integrated pest management in agriculture and forestry, and efficiency in density estimation is a common goal. Sequential sampling techniques promise efficient sampling, but their application can involve cumbersome mathematics and/or intensive warm-up sampling when pests have complex within- or between-site distributions. We provide tools for assessing the efficiency of sequential sampling and of alternative, simpler sampling plans, using computer simulation with “pre-sampling” data. We illustrate our approach using data for balsam gall midge (Paradiplosis tumifex) attack in Christmas tree farms. Paradiplosis tumifex proved recalcitrant to sequential sampling techniques. Midge distributions could not be fit by a common negative binomial distribution across sites. Local parameterization, using warm-up samples to estimate the clumping parameter k for each site, performed poorly: k estimates were unreliable even for samples of n∼100 trees. These methods were further confounded by significant within-site spatial autocorrelation. Much simpler sampling schemes, involving random or belt-transect sampling to preset sample sizes, were effective and efficient for P. tumifex. Sampling via belt transects (through the longest dimension of a stand) was the most efficient, with sample means converging on true mean density for sample sizes of n∼25–40 trees. Pre-sampling and simulation techniques provide a simple method for assessing sampling strategies for estimating insect infestation. We suspect that many pests will resemble P. tumifex in challenging the assumptions of sequential sampling methods. Our software will allow practitioners to optimize sampling strategies before they are brought to real-world applications, while potentially avoiding the need for the cumbersome calculations required for sequential sampling methods. PMID:24376556

The impact of new vaccine introduction on immunization and health systems: A review of the published literature

PubMed Central

Hyde, Terri B.; Dentz, Holly; Wang, Susan A.; Burchett, Helen E.; Mounier-Jack, Sandra; Mantel, Carsten F.

2015-01-01

We conducted a systematic review of the published literature to examine the impact of new vaccine introduction on countries’ immunization and broader health systems. Six publication databases were searched using 104 vaccine and health system-related search terms. The search yielded 15,795 unique articles dating from December 31, 1911 to September 29, 2010. Based on review of the title and abstract, 654 (4%) of these articles were found to be potentially relevant and were referred for full review. After full review, 130 articles were found to be relevant and included in the analysis. These articles represented vaccines introduced to protect against 10 different diseases (hepatitis A, hepatitis B, Haemophilus influenzae type b disease, human papilloma virus infection, influenza, Japanese encephalitis, meningococcal meningitis, Streptococcus pneumoniae disease, rotavirus diarrhea and typhoid), in various formulations and combinations. Most reviewed articles (97 [75%]) reported experiences in high-income countries. New vaccine introduction was most efficient when the vaccine was introduced into an existing delivery platform and when introduced in combination with a vaccine already in the routine childhood immunization schedule (i.e., as a combination vaccine). New vaccine introduction did not impact coverage of vaccines already included in the routine childhood immunization schedule. The need for increased cold chain capacity was frequently reported. New vaccines facilitated the introduction and widespread use of auto-disable syringes into the immunization and the broader health systems. The importance of training and education for health care workers and social mobilization was frequently noted. There was evidence in high-income countries that new vaccine introduction was associated with reduced health-care costs. Future evaluations of new vaccine introductions should include the systematic and objective assessment of the impacts on a country’s immunization system and broader health system, especially in lower-income countries. PMID:22940378

The first detected airline introductions of yellow fever mosquitoes (Aedes aegypti) to Europe, at Schiphol International airport, the Netherlands.

PubMed

Ibañez-Justicia, A; Gloria-Soria, A; den Hartog, W; Dik, M; Jacobs, F; Stroo, A

2017-12-08

Air-borne introduction of exotic mosquitoes to Schiphol airport in the Netherlands has been considered plausible based upon findings of mosquitoes in aircraft cabins during 2008, 2010 and 2011. Beginning in 2013, surveillance efforts at Schiphol had focused on promptly detecting accidental introductions at the airport facilities in order to quickly react and avoid temporary proliferation or establishment of mosquito populations, identify the origin of the introductions, and avoid potential transmission of vector-borne diseases. BG-Mosquitaire mosquito traps were set at the most likely locations for arrival of the invasive Aedes mosquitoes as part of the mosquito monitoring program at Schiphol airport. Samples were collected bi-weekly. Upon detection of exotic specimens, information about the origin of the flights arriving to the particular location at the airport where specimens were captured was requested from airport authorities. The GIS tool Intersect was then used to identify airports of origin common to positive trapping locations during the specific trapping period. Captured Aedes aegypti mosquitoes were subsequently genotyped at 12 highly polymorphic microsatellite markers and compared to a reference database of 79 populations around the world to further narrow down their location of origin. In 2016, six adult yellow fever mosquitoes were captured indoors and outdoors at the airport of Schiphol in the Netherlands confirming, for the first time, air-borne transport of this mosquito vector species into Europe. Mosquitoes were captured during three time periods: June, September and October. Containers carried by aircrafts are considered the most likely pathway for this introduction. GIS analysis and genetic assignment tests on these mosquitoes point to North America or the Middle East as possible origins, but the small sample size prevents us from reliably identifying the geographic origin of this introduction. The arrival of Ae. aegypti mosquitoes to Schiphol airport from flights arriving from overseas, demonstrates the potential risk of international flights to public health as carriers of arthropod vectors of disease. The results strongly suggest that disinsection of containers and their storage compartments inside the aircrafts could contribute to preventing future introductions of mosquito vectors. Invasive mosquito species introduced by aircrafts from overseas could become seasonally established during the warmer months in Europe, or permanently in certain climatically suitable areas for the species, with major consequences for human health.

Comparative analysis of quantitative efficiency evaluation methods for transportation networks

PubMed Central

He, Yuxin; Hong, Jian

2017-01-01

An effective evaluation of transportation network efficiency could offer guidance for the optimal control of urban traffic. Based on the introduction and related mathematical analysis of three quantitative evaluation methods for transportation network efficiency, this paper compares the information measured by them, including network structure, traffic demand, travel choice behavior and other factors which affect network efficiency. Accordingly, the applicability of various evaluation methods is discussed. Through analyzing different transportation network examples it is obtained that Q-H method could reflect the influence of network structure, traffic demand and user route choice behavior on transportation network efficiency well. In addition, the transportation network efficiency measured by this method and Braess’s Paradox can be explained with each other, which indicates a better evaluation of the real operation condition of transportation network. Through the analysis of the network efficiency calculated by Q-H method, it can also be drawn that a specific appropriate demand is existed to a given transportation network. Meanwhile, under the fixed demand, both the critical network structure that guarantees the stability and the basic operation of the network and a specific network structure contributing to the largest value of the transportation network efficiency can be identified. PMID:28399165

Comparative analysis of quantitative efficiency evaluation methods for transportation networks.

PubMed

He, Yuxin; Qin, Jin; Hong, Jian

2017-01-01

An effective evaluation of transportation network efficiency could offer guidance for the optimal control of urban traffic. Based on the introduction and related mathematical analysis of three quantitative evaluation methods for transportation network efficiency, this paper compares the information measured by them, including network structure, traffic demand, travel choice behavior and other factors which affect network efficiency. Accordingly, the applicability of various evaluation methods is discussed. Through analyzing different transportation network examples it is obtained that Q-H method could reflect the influence of network structure, traffic demand and user route choice behavior on transportation network efficiency well. In addition, the transportation network efficiency measured by this method and Braess's Paradox can be explained with each other, which indicates a better evaluation of the real operation condition of transportation network. Through the analysis of the network efficiency calculated by Q-H method, it can also be drawn that a specific appropriate demand is existed to a given transportation network. Meanwhile, under the fixed demand, both the critical network structure that guarantees the stability and the basic operation of the network and a specific network structure contributing to the largest value of the transportation network efficiency can be identified.

Superparamagnetic PLGA-iron oxide microcapsules for dual-modality US/MR imaging and high intensity focused US breast cancer ablation.

PubMed

Sun, Yang; Zheng, Yuanyi; Ran, Haitao; Zhou, Yang; Shen, Hongxia; Chen, Yu; Chen, Hangrong; Krupka, Tianyi M; Li, Ao; Li, Pan; Wang, Zhibiao; Wang, Zhigang

2012-08-01

Organic/inorganic, hybrid, multifunctional, material-based platforms combine the merits of diverse functionalities of inorganic nanoparticles and the excellent biocompatibility of organic systems. In this work, superparamagnetic poly(lactic-co-glycolic acid) (PLGA) microcapsules (Fe(3)O(4)/PLGA) have been developed, as a proof-of-concept, for the application in ultrasound/magnetic resonance dual-modality biological imaging and enhancing the therapeutic efficiency of high intensity focused ultrasound (HIFU) breast cancer surgery in vitro and in vivo. Hydrophobic Fe(3)O(4) nanoparticles were successfully integrated into PLGA microcapsules by a typical double emulsion evaporation process. In this process, highly dispersed superparamagnetic Fe(3)O(4)/PLGA composite microcapsules with well-defined spherical morphology were obtained with an average diameter of 885.6 nm. The potential of these microcapsules as dual contrast agents for ultrasonography and magnetic resonance imaging were demonstrated in vitro and, also, preliminarily in vivo. Meanwhile, the prepared superparamagnetic composite microcapsules were administrated into rabbits bearing breast cancer model for the evaluation of the in vivo HIFU synergistic ablation efficiency caused by the introduction of such microcapsules. Our results showed that the employment of the composite microcapsules could efficiently enhance ultrasound imaging of cancer, and greatly enhance the HIFU ablation of breast cancer in rabbits. In addition, pathological examination was systematically performed to detect the structural changes of the target tissue caused by HIFU ablation. This finding demonstrated that successful introduction of these superparamagnetic microcapsules into HIFU cancer surgery provided an alternative strategy for the highly efficient imaging-guided non-invasive HIFU synergistic therapy of cancer. Copyright © 2012 Elsevier Ltd. All rights reserved.

Direct Liquid Sampling for Corona Discharge Ion Mobility Spectrometry.

PubMed

Sabo, Martin; Malásková, Michaela; Harmathová, Olga; Hradski, Jasna; Masár, Marián; Radjenovic, Branislav; Matejčík, Štefan

2015-07-21

We present a new technique suitable for direct liquid sampling and analysis by ion mobility spectrometry (IMS). The technique is based on introduction of a droplet stream to the IMS reaction region. The technique was successfully used to detect explosives dissolved in methanol and oil as well as to analyze amino acids and dipeptides. One of the main advantages of this technique is its ability to analyze liquid samples without the requirement of any special solution.

Identifying Immune Drivers of Gulf War Illness Using a Novel Daily Sampling Approach

DTIC Science & Technology

2017-10-01

AWARD NUMBER: W81XWH-12-1-0557 TITLE: Identifying Immune Drivers of Gulf War Illness Using a Novel Daily Sampling Approach PRINCIPAL...TITLE AND SUBTITLE Identifying Immune Drivers of Gulf War Illness Using A Novel 5a. CONTRACT NUMBER Daily Sampling Approach 5b. GRANT NUMBER...INTRODUCTION: The major aim of this research project is to identify aspects of the immune system that are dysregulated in veterans with Gulf War Illness

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

Wollaber, Allan Benton

This is a powerpoint presentation which serves as lecture material for the Parallel Computing summer school. It goes over the fundamentals of the Monte Carlo calculation method. The material is presented according to the following outline: Introduction (background, a simple example: estimating π), Why does this even work? (The Law of Large Numbers, The Central Limit Theorem), How to sample (inverse transform sampling, rejection), and An example from particle transport.

Recovery of Picloram and 2,4-Dichlorophenoxyacetic Acid from Aqueous Samples by Reversed-Phase Solid-Phase Extraction

Treesearch

Martha J.M. Wells; Jerry L. Michael

1987-01-01

Extensive preparation of samples before chromatographic analysis is usually the most time-consuming process in the determination of many organic compounds in environmental matrices. In the past, removal of some organic from aqueous solution was commonly done by liquid/liquid extraction. However, the introduction of stable, covalently bonded reversed-phase sorbents now...

Physics 30 Program Machine-Scorable Open-Ended Questions: Unit 2: Electric and Magnetic Forces. Diploma Examinations Program.

ERIC Educational Resources Information Center

Alberta Dept. of Education, Edmonton.

This document outlines the use of machine-scorable open-ended questions for the evaluation of Physics 30 in Alberta. Contents include: (1) an introduction to the questions; (2) sample instruction sheet; (3) fifteen sample items; (4) item information including the key, difficulty, and source of each item; (5) solutions to items having multiple…

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.

Relative efficiency of anuran sampling methods in a restinga habitat (Jurubatiba, Rio de Janeiro, Brazil).

PubMed

Rocha, C F D; Van Sluys, M; Hatano, F H; Boquimpani-Freitas, L; Marra, R V; Marques, R V

2004-11-01

Studies on anurans in restinga habitats are few and, as a result, there is little information on which methods are more efficient for sampling them in this environment. Ten methods are usually used for sampling anuran communities in tropical and sub-tropical areas. In this study we evaluate which methods are more appropriate for this purpose in the restinga environment of Parque Nacional da Restinga de Jurubatiba. We analyzed six methods among those usually used for anuran samplings. For each method, we recorded the total amount of time spent (in min.), the number of researchers involved, and the number of species captured. We calculated a capture efficiency index (time necessary for a researcher to capture an individual frog) in order to make comparable the data obtained. Of the methods analyzed, the species inventory (9.7 min/searcher /ind.- MSI; richness = 6; abundance = 23) and the breeding site survey (9.5 MSI; richness = 4; abundance = 22) were the most efficient. The visual encounter inventory (45.0 MSI) and patch sampling (65.0 MSI) methods were of comparatively lower efficiency restinga, whereas the plot sampling and the pit-fall traps with drift-fence methods resulted in no frog capture. We conclude that there is a considerable difference in efficiency of methods used in the restinga environment and that the complete species inventory method is highly efficient for sampling frogs in the restinga studied and may be so in other restinga environments. Methods that are usually efficient in forested areas seem to be of little value in open restinga habitats.

Improving Efficiency with Work Sampling.

ERIC Educational Resources Information Center

Friedman, Mark; Hertz, Paul

1982-01-01

Work sampling is a managerial accounting technique which provides information about the efficiency of an operation. This analysis determines what tasks are being performed durinq a period of time to ascertain if time and effort are being allocated efficiently. (SK)

Introduction to Mars Sampling Handling Workshop Series. Workshop on Life Detection: Issues and Topics

NASA Technical Reports Server (NTRS)

Rummel, John D.

2001-01-01

Before martian soil and rock samples can be distributed to the research community, the returned materials will initially be quarantined and examined in a proposed BSL-4 containment facility to assure that no putative martian microorganisms or attendant potential biohazards exist. During the initial quarantine, state-of-the-art life detection and biohazard testing of the returned martian samples will be conducted. Life detection, as defined here in regard to Mars sample return missions, is the detection of living organisms and/or materials that have been derived from living organisms that may be present in the sample.

Molecular comparison of the sampling efficiency of four types of airborne bacterial samplers.

PubMed

Li, Kejun

2011-11-15

In the present study, indoor and outdoor air samples were collected using four types of air samplers often used for airborne bacterial sampling. These air samplers included two solid impactors (BioStage and RCS), one liquid impinger (BioSampler), and one filter sampler with two kinds of filters (a gelatin and a cellulose acetate filter). The collected air samples were further processed to analyze the diversity and abundance of culturable bacteria and total bacteria through standard culture techniques, denaturing gradient gel electrophoresis (DGGE) fingerprinting and quantitative polymerase chain reaction (qPCR) analysis. The DGGE analysis indicated that the air samples collected using the BioStage and RCS samplers have higher culturable bacterial diversity, whereas the samples collected using the BioSampler and the cellulose acetate filter sampler have higher total bacterial diversity. To obtain more information on the sampled bacteria, some gel bands were excised and sequenced. In terms of sampling efficiency, results from the qPCR tests indicated that the collected total bacterial concentration was higher in samples collected using the BioSampler and the cellulose acetate filter sampler. In conclusion, the sampling bias and efficiency of four kinds of air sampling systems were compared in the present study and the two solid impactors were concluded to be comparatively efficient for culturable bacterial sampling, whereas the liquid impactor and the cellulose acetate filter sampler were efficient for total bacterial sampling. Copyright © 2011 Elsevier B.V. All rights reserved.

JPRS Report, China.

DTIC Science & Technology

1988-06-24

departments incapable of managing social economic development in Zhejiang. The broad introduction of the personal responsibility system and other... SOCIAL Wang Feng Addresses Conference on Civil Disputes, Commends Mediation Work [FAZHIBAO 14 JulJ 43 Educational Spending per High School Student Tar...RIBAO 11 JulJ 46 Zhejiang Governor Shen Zulun Calls for Personal , Administrative Efficiency fZHEJIANG RIBAO 22 JulJ 46 HONG KONG, MACAO Li Yu

A novel molecular diagnostic tool for improved sensitivity and reliability detection of “Candidatus Liberibacter asiaticus”, bacterium associated with huanglongbing (HLB) bacterium Candidatus Liberibacter.

USDA-ARS?s Scientific Manuscript database

Sensitive and accurate detection is a prerequisite for efficient management and regulatory responses to prevent the introduction and spread of HLB-associated “Candidatus Liberibacter species to unaffected areas. To improve the current detection limit of HLB-associated “Ca. Liberibacter” spp, we deve...

Selective Attention: A Comparative Study on Argentine Students from Different Socioeconomic Contexts

ERIC Educational Resources Information Center

Ison, Mirta S.; Greco, Carolina; Korzeniowski, Celina; Morelato, Gabriela

2015-01-01

Introduction: Attentional Efficiency (AE) is defined as the accuracy with which a child discriminates, from a group of similar stimuli, those which are identical to a model, within a certain time period. Various factors may be associated with a higher or lower AE, among which is socioeconomic context. The goals of this study were: 1) To describe…