A far-infrared spatial/spectral Fourier interferometry laboratory-based testbed instrument

NASA Astrophysics Data System (ADS)

Spencer, Locke D.; Naylor, David A.; Scott, Jeremy P.; Weiler, Vince F.; MacCrimmon, Roderick K.; Sitwell, Geoffrey R. H.; Ade, Peter A. R.

2016-07-01

We describe the current status, including preliminary design, characterization efforts, and recent progress, in the development of a spatial/spectral double Fourier laboratory-based interferometer testbed instrument within the Astronomical Instrumentation Group (AIG) laboratories at the University of Lethbridge, Canada (UL). Supported by CRC, CFI, and NSERC grants, this instrument development will provide laboratory demonstration of spatial-spectral interferometry with a concentration of furthering progress in areas including the development of spatial/spectral interferometry observation, data processing, characterization, and analysis techniques in the Far-Infrared (FIR) region of the electromagnetic spectrum.

Solar Cell Calibration and Measurement Techniques

NASA Technical Reports Server (NTRS)

Bailey, Sheila; Brinker, Dave; Curtis, Henry; Jenkins, Phillip; Scheiman, Dave

1997-01-01

The increasing complexity of space solar cells and the increasing international markets for both cells and arrays has resulted in workshops jointly sponsored by NASDA, ESA and NASA. These workshops are designed to obtain international agreement on standardized values for the AMO spectrum and constant, recommend laboratory measurement practices and establish a set of protocols for international comparison of laboratory measurements. A working draft of an ISO standard, WDI 5387, 'Requirements for Measurement and Calibration Procedures for Space Solar Cells' was discussed with a focus on the scope of the document, a definition of primary standard cell, and required error analysis for all measurement techniques. Working groups addressed the issues of Air Mass Zero (AMO) solar constant and spectrum, laboratory measurement techniques, and the international round robin methodology. A summary is presented of the current state of each area and the formulation of the ISO document.

Solar Cell Calibration and Measurement Techniques

NASA Technical Reports Server (NTRS)

Bailey, Sheila; Brinker, Dave; Curtis, Henry; Jenkins, Phillip; Scheiman, Dave

2004-01-01

The increasing complexity of space solar cells and the increasing international markets for both cells and arrays has resulted in workshops jointly sponsored by NASDA, ESA and NASA. These workshops are designed to obtain international agreement on standardized values for the AMO spectrum and constant, recommend laboratory measurement practices and establish a set of protocols for international comparison of laboratory measurements. A working draft of an ISO standard, WD15387, "Requirements for Measurement and Calibration Procedures for Space Solar Cells" was discussed with a focus on the scope of the document, a definition of primary standard cell, and required error analysis for all measurement techniques. Working groups addressed the issues of Air Mass Zero (AMO) solar constant and spectrum, laboratory measurement techniques, and te international round robin methodology. A summary is presented of the current state of each area and the formulation of the ISO document.

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

None

Argonne National Laboratory researchers have invented a technology for recovering oil and refined petroleum products from bodies of water. Oleo Sponge offers several key advantages over the technologies and techniques that are currently used to combat this problem.

An Undergraduate Investigation into the 10-23 DNA Enzyme that Cleaves RNA: DNA Can Cut It in the Biochemistry Laboratory

ERIC Educational Resources Information Center

Flynn-Charlebois, Amber; Burns, Jamie; Chapelliquen, Stephanie; Sanmartino, Holly

2011-01-01

A low-cost biochemistry experiment is described that demonstrates current techniques in the use of catalytic DNA molecules and introduces a nonradioactive, nonfluorescent, inexpensive, fast, and safe method for monitoring these nucleic acid reactions. The laboratory involves the exploration of the 10-23 DNA enzyme as it cleaves a specific RNA…

Laboratory experiment on the 3D tide-induced Lagrangian residual current using the PIV technique

NASA Astrophysics Data System (ADS)

Chen, Yang; Jiang, Wensheng; Chen, Xu; Wang, Tao; Bian, Changwei

2017-12-01

The 3D structure of the tide-induced Lagrangian residual current was studied using the particle image velocimetry (PIV) technique in a long shallow narrow tank in the laboratory. At the mouth of the tank, a wave generator was used to make periodic wave which represents the tide movement, and at the head of the tank, a laterally sloping topography with the length of one fifth of the water tank was installed, above which the tide-induced Lagrangian residual current was studied. Under the weakly nonlinear condition in the present experiment setup, the results show that the Lagrangian residual velocity (LRV) field has a three-layer structure. The residual current flows inwards (towards the head) in the bottom layer and flows outwards in the middle layer, while in the surface layer, it flows inwards along the shallow side of the sloping topography and outwards along the deep side. The depth-averaged and breadth-averaged LRV are also analyzed based on the 3D LRV observations. Our results are in good agreement with the previous experiment studies, the analytical solutions with similar conditions and the observational results in real bays. Moreover, the volume flux comparison between the Lagrangian and Eulerian residual currents shows that the Eulerian residual velocity violates the mass conservation law while the LRV truly represents the inter-tidal water transport. This work enriches the laboratory studies of the LRV and offers valuable references for the LRV studies in real bays.

Interface demarcation in GaAs by current pulsing

NASA Technical Reports Server (NTRS)

Matthiesen, D. H.; Kafalas, J. A.; Duchene, G. A.; Bellows, A. H.

1990-01-01

GTE Laboratories is currently conducting a program to investigate the effect of convection in the melt on the properties of bulk grown gallium arsenide (GaAs). In addition to extensive ground based experimentation, a Get Away Special growth system has been developed to grow two GaAs crystals aboard the Space Shuttle, each with a one inch diameter. In order to perform a complete segregation analysis of the crystals grown in space, it is necessary to measure the interface shape and growth rate as well as the spatial distribution of the selenium dopant. The techniques for interface demarcation in selenium doped GaAs by current pulsing have been developed at GTE Laboratories and successful interface demarcation has been achieved for current pulses ranging from 20 to 90 amps, in both single crystal and polycrystalline regions.

Peptide radioimmunoassays in clinical medicine.

PubMed

Geokas, M C; Yalow, R S; Straus, E W; Gold, E M

1982-09-01

The radioimmunoassay technique, first developed for the determination of hormones, has been applied to many substances of biologic interest by clinical and research laboratories around the world. It has had an enormous effect in medicine and biology as a diagnostic tool, a guide to therapy, and a probe for the fine structure of biologic systems. For instance, the assays of insulin, gastrin, secretin, prolactin, and certain tissue-specific enzymes have been invaluable in patient care. Further refinements of current methods, as well as the emergence of new immunoassay techniques, are expected to enhance precision, specificity, reliability, and convenience of the radioimmunoassay in both clinical and research laboratories.

A Virtual Rock Physics Laboratory Through Visualized and Interactive Experiments

NASA Astrophysics Data System (ADS)

Vanorio, T.; Di Bonito, C.; Clark, A. C.

2014-12-01

As new scientific challenges demand more comprehensive and multidisciplinary investigations, laboratory experiments are not expected to become simpler and/or faster. Experimental investigation is an indispensable element of scientific inquiry and must play a central role in the way current and future generations of scientist make decisions. To turn the complexity of laboratory work (and that of rocks!) into dexterity, engagement, and expanded learning opportunities, we are building an interactive, virtual laboratory reproducing in form and function the Stanford Rock Physics Laboratory, at Stanford University. The objective is to combine lectures on laboratory techniques and an online repository of visualized experiments consisting of interactive, 3-D renderings of equipment used to measure properties central to the study of rock physics (e.g., how to saturate rocks, how to measure porosity, permeability, and elastic wave velocity). We use a game creation system together with 3-D computer graphics, and a narrative voice to guide the user through the different phases of the experimental protocol. The main advantage gained in employing computer graphics over video footage is that students can virtually open the instrument, single out its components, and assemble it. Most importantly, it helps describe the processes occurring within the rock. These latter cannot be tracked while simply recording the physical experiment, but computer animation can efficiently illustrate what happens inside rock samples (e.g., describing acoustic waves, and/or fluid flow through a porous rock under pressure within an opaque core-holder - Figure 1). The repository of visualized experiments will complement lectures on laboratory techniques and constitute an on-line course offered through the EdX platform at Stanford. This will provide a virtual laboratory for anyone, anywhere to facilitate teaching/learning of introductory laboratory classes in Geophysics and expand the number of courses that can be offered for curricula in Earth Sciences. The primary goal is to open up a research laboratory such as the one available at Stanford to promising students worldwide who are currently left out of such educational resources.

Development of a switched integrator amplifier for high-accuracy optical measurements.

PubMed

Mountford, John; Porrovecchio, Geiland; Smid, Marek; Smid, Radislav

2008-11-01

In the field of low flux optical measurements, the development and use of large area silicon detectors is becoming more frequent. The current/voltage conversion of their photocurrent presents a set of problems for traditional transimpedance amplifiers. The switched integration principle overcomes these limitations. We describe the development of a fully characterized current-voltage amplifier using the switched integrator technique. Two distinct systems have been developed in parallel at the United Kingdom's National Physical Laboratory (NPL) and Czech Metrology Institute (CMI) laboratories. We present the circuit theory and best practice in the design and construction of switched integrators. In conclusion the results achieved and future developments are discussed.

Nonpharmacological, Blood Conservation Techniques for Preventing Neonatal Anemia—Effective and Promising Strategies for Reducing Transfusion

PubMed Central

Carroll, Patrick D.; Widness, John A.

2012-01-01

The development of anemia after birth in very premature, critically ill newborn infants is a universal well-described phenomenon. Although preventing anemia in this population, along with efforts to establish optimal red blood cell (RBC) transfusion and pharmacologic therapy continue to be actively investigated, the present review focuses exclusively on nonpharmacological approaches to the prevention and treatment of neonatal anemia. We begin with an overview of topics relevant to nonpharmacological techniques. These topics include neonatal and fetoplacental hemoglobin levels and blood volumes, clinical and laboratory practices applied in critically ill neonates, and current RBC transfusion practice guidelines. This is followed by a discussion of the most effective and promising nonpharmacological blood conservation strategies and techniques. Fortunately, many of these techniques are feasible in most neonatal intensive care units. When applied together, these techniques are more effective than existing pharmacotherapies in significantly decreasing neonatal RBC transfusions. They include increasing hemoglobin endowment and circulating blood volume at birth; removing less blood for laboratory testing; and optimizing nutrition. PMID:22818543

Currents between tethered electrodes in a magnetized laboratory plasma

NASA Technical Reports Server (NTRS)

Stenzel, R. L.; Urrutia, J. M.

1989-01-01

Laboratory experiments on important plasma physics issues of electrodynamic tethers were performed. These included current propagation, formation of wave wings, limits of current collection, nonlinear effects and instabilities, charging phenomena, and characteristics of transmission lines in plasmas. The experiments were conducted in a large afterglow plasma. The current system was established with a small electron-emitting hot cathode tethered to an electron-collecting anode, both movable across the magnetic field and energized by potential difference up to V approx.=100 T(sub e). The total current density in space and time was obtained from complete measurements of the perturbed magnetic field. The fast spacecraft motion was reproduced in the laboratory by moving the tethered electrodes in small increments, applying delayed current pulses, and reconstructing the net field by a linear superposition of locally emitted wavelets. With this technique, the small-amplitude dc current pattern is shown to form whistler wings at each electrode instead of the generally accepted Alfven wings. For the beam electrode, the whistler wing separates from the field-aligned beam which carries no net current. Large amplitude return currents to a stationary anode generate current-driven microinstabilities, parallel electric fields, ion depletions, current disruptions and time-varying electrode charging. At appropriately high potentials and neutral densities, excess neutrals are ionized near the anode. The anode sheath emits high-frequency electron transit-time oscillations at the sheath-plasma resonance. The beam generates Langmuir turbulence, ion sound turbulence, electron heating, space charge fields, and Hall currents. An insulated, perfectly conducting transmission line embedded in the plasma becomes lossy due to excitation of whistler waves and magnetic field diffusion effects. The implications of the laboratory observations on electrodynamic tethers in space are discussed.

[Patient satisfaction in a laboratory test collection unit].

PubMed

de Moura, Gisela Maria Schebella Souto; Hilleshein, Eunice Fabiani; Schardosim, Juliana Machado; Delgado, Kátia Simone

2008-06-01

This exploratory descriptive study aimed at identifying customer satisfaction attributes in the field of laboratory tests. Data were collected in 2006, using 104 interviews in a laboratorial unit inside a teaching hospital, using the critical incident technique, and submitted to content analysis. Three attribute categories were identified: time spent in waiting for care, interpersonal contact, and technical skills. These results subsidize the assessment of the current satisfaction survey tool, and point to its reformulation. They also allow the identification of improvement needs in customer attention, and provide elements to be taken into account in personnel selection, training programs, personnel performance assessment.

Key issues concerning environmental enrichment for laboratory-held fish species.

PubMed

Williams, T D; Readman, G D; Owen, S F

2009-04-01

An improved knowledge and understanding of the fundamental biological requirements is needed for many of the species of fish held in captivity and, without this knowledge it is difficult to determine the optimal conditions for laboratory culture. The aim of this paper is to review the key issues concerning environmental enrichment for laboratory-held fish species and identify where improvements are required. It provides background information on environmental enrichment, describes enrichment techniques currently used in aquatic ecotoxicology studies, identifies potential restrictions in their use and discusses why more detailed and species-specific guidance is needed.

An Historical Perspective on the Theory and Practice of Soil Mechanical Analysis.

ERIC Educational Resources Information Center

Miller, W. P.; And Others

1988-01-01

Traces the history of soil mechanical analysis. Evaluates this history in order to place current concepts in perspective, from both a research and teaching viewpoint. Alternatives to traditional separation techniques for use in soils teaching laboratories are discussed. (TW)

[Microbiological Surveillance of Measles and Rubella in Spain. Laboratory Network].

PubMed

Echevarría, Juan Emilio; Fernández García, Aurora; de Ory, Fernando

2015-01-01

The Laboratory is a fundamental component on the surveillance of measles and rubella. Cases need to be properly confirmed to ensure an accurate estimation of the incidence. Strains should be genetically characterized to know the transmission pattern of these viruses and frequently, outbreaks and transmission chains can be totally discriminated only after that. Finally, the susceptibility of the population is estimated on the basis of sero-prevalence surveys. Detection of specific IgM response is the base of the laboratory diagnosis of these diseases. It should be completed with genomic detection by RT-PCR to reach an optimal efficiency, especially when sampling is performed early in the course of the disease. Genotyping is performed by genomic sequencing according to reference protocols of the WHO. Laboratory surveillance of measles and rubella in Spain is organized as a net of regional laboratories with different capabilities. The National Center of Microbiology as National Reference Laboratory (NRL), supports regional laboratories ensuring the availability of all required techniques in the whole country and watching for the quality of the results. The NRL is currently working in the implementation of new molecular techniques based on the analysis of genomic hypervariable regions for the strain characterization at sub-genotypic levels and use them in the surveillance.

Glucose-6-phosphate dehydrogenase laboratory assay: How, when, and why?

PubMed

Minucci, Angelo; Giardina, Bruno; Zuppi, Cecilia; Capoluongo, Ettore

2009-01-01

Glucose 6-phosphate dehydrogenase (G6PD) deficiency is the most common defect of red blood cells. Although some different laboratory techniques or methods are employed for the biochemical screening, a strict relationship between biochemists, clinicians, and molecular biologists is necessary for a definitive diagnosis. This article represents an overview on the current laboratory tests finalized to the screening or to the definitive diagnosis of G6PD-deficiency, underlying the problems regarding the biochemical and molecular identification of heterozygote females other than those regarding the standardization of the clinical and laboratory diagnostic procedures. Finally, this review is aimed to give a flow-chart for the complete diagnostic approach of G6PD-deficiency.

Diagnosis of Dengue Infection Using Conventional and Biosensor Based Techniques

PubMed Central

Parkash, Om; Hanim Shueb, Rafidah

2015-01-01

Dengue is an arthropod-borne viral disease caused by four antigenically different serotypes of dengue virus. This disease is considered as a major public health concern around the world. Currently, there is no licensed vaccine or antiviral drug available for the prevention and treatment of dengue disease. Moreover, clinical features of dengue are indistinguishable from other infectious diseases such as malaria, chikungunya, rickettsia and leptospira. Therefore, prompt and accurate laboratory diagnostic test is urgently required for disease confirmation and patient triage. The traditional diagnostic techniques for the dengue virus are viral detection in cell culture, serological testing, and RNA amplification using reverse transcriptase PCR. This paper discusses the conventional laboratory methods used for the diagnosis of dengue during the acute and convalescent phase and highlights the advantages and limitations of these routine laboratory tests. Subsequently, the biosensor based assays developed using various transducers for the detection of dengue are also reviewed. PMID:26492265

Challenges to laboratory hematology practice: Egypt perspective.

PubMed

Rizk, S H

2018-05-01

Laboratory hematology is an integral part of all clinical laboratories along the extensive healthcare facilities in Egypt. The aim of this review is to portrait the laboratory hematology practice in Egypt including its unique socioeconomic background, blood disease pattern, education and training, regulatory oversight, and the related challenges. Current practice varies widely between different parts of the healthcare system in terms of the range of tests, applied techniques, workforce experience, and quality of service. The national transfusion service (NBTS) in Egypt has been recently upgraded and standardized according to the World Health Organization (WHO) guidelines. Formal postgraduate education roughly follows the British system. Laboratory hematology specialization is achieved through 2-3 years masters' degree followed by 2-4 years doctorate degree in clinical pathology with training and research in hematology. Improvement of laboratory hematology education is recently undergoing a reform as a part of the modernization of higher education policy and following the standards developed by the National Quality Assurance and Accreditation Agency (NQAAA). Accreditation of medical laboratories is recently progressing with the development of the "Egyptian Accreditation Council" (EGAC) as the sole accreditation body system and training of assessors. Current laboratory system has many challenges, some are related to the inadequate system performance, and others are unique to laboratory hematology issues. The rapid technological advances and therapeutic innovations in hematology practice call for an adapting laboratory system with continuous upgrading. © 2018 John Wiley & Sons Ltd.

Kinematic cooling of molecules in a magneto-optical trap

NASA Astrophysics Data System (ADS)

Takase, Ken; Chandler, David W.; Strecker, Kevin E.

2008-05-01

We will present our current progress on a new experimental technique aimed at slowing and cooling hot molecules using a single collision with magneto-optically trapped atoms. Kinematic cooling, unlike buffer gas and sympathetic cooling, relies only on a single collision between the molecule and atom to stop the molecule in the laboratory frame. This technique has recently been demonstrated in a crossed atomic and molecular beam machine to produce 35mK samples of nitric oxide via a single collision with argon [1]. In this technique we replace the atomic beam with a sample magneto-optically trapped atoms. We are currently designing and building a new apparatus to attempt these experiments. [1] Kevin E. Strecker and David W. Chandler (to be published)

Submillimeter Laboratory Investigations: Spectroscopy and Collisions

NASA Technical Reports Server (NTRS)

Herbst, Eric; DeLucia, Frank C.

2002-01-01

Currently, millimeter-wave and submillimeter-wave spectroscopy is conducted in our laboratory on several different types of spectrometers. Our standard spectrometer utilizes the output of a phase-locked klystron operating in the 40-60 GHz region, which is sent into a crossed-waveguide harmonic generator, or "multiplier". The high frequency millimeter-and submillimeter-wave radiation is transmitted via quasi-optical techniques through an absorption cell and then onto a detector, which is either an InSb hot electron bolometer cooled to 1.4 K or a Si bolometer cooled to 0.3 K. The detector response is sent to a computer for measurement and analysis. The frequency range produced and detected in this manner goes from 80 GHz to upwards of 1 THz. Spectra are normally taken with source modulation, with line frequencies typically measured to an accuracy of 50-100 kHz. Higher accuracy is available when needed. Recently, we developed a new, broad-band spectrometer in our laboratory based on a free-running backward wave oscillator (BWO) of Russian manufacture as the primary source of radiation. The so-called FASSST (fast-scan submillimeter spectroscopic technique) system uses fast-scan and optical calibration methods rather than the traditional locking techniques. The output power from the BWO is split such that 90% goes into the absorption cell while 10% is coupled to a 40-meter Fabry-Perot cavity, which yields fringe? for frequency measurement. Results from this spectrometer on the spectrum of nitric acid (HNO3) show that 100 GHz of spectral data can be obtained in 5 seconds with a measurement accuracy of 50 kHz. Currently, the frequency range of the FASSST system in our laboratory is roughly 100-700 GHz.

Ring Current Pressure Estimation withRAM-SCB using Data Assimilation and VanAllen Probe Flux Data

NASA Astrophysics Data System (ADS)

Godinez, H. C.; Yu, Y.; Henderson, M. G.; Larsen, B.; Jordanova, V.

2015-12-01

Capturing and subsequently modeling the influence of tail plasma injections on the inner magnetosphere is particularly important for understanding the formation and evolution of Earth's ring current. In this study, the ring current distribution is estimated with the Ring Current-Atmosphere Interactions Model with Self-Consistent Magnetic field (RAM-SCB) using, for the first time, data assimilation techniques and particle flux data from the Van Allen Probes. The state of the ring current within the RAM-SCB is corrected via an ensemble based data assimilation technique by using proton flux from one of the Van Allen Probes, to capture the enhancement of ring current following an isolated substorm event on July 18 2013. The results show significant improvement in the estimation of the ring current particle distributions in the RAM-SCB model, leading to better agreement with observations. This newly implemented data assimilation technique in the global modeling of the ring current thus provides a promising tool to better characterize the effect of substorm injections in the near-Earth regions. The work is part of the Space Hazards Induced near Earth by Large, Dynamic Storms (SHIELDS) project in Los Alamos National Laboratory.

Integrating Multimedia Techniques into CS Pedagogy.

ERIC Educational Resources Information Center

Adams, Sandra Honda; Jou, Richard; Nasri, Ahmad; Radimsky, Anne-Louise; Sy, Bon K.

Through its grants, the National Science Foundation sponsors workshops that inform faculty of current topics in computer science. Such a workshop, entitled, "Developing Multimedia-based Interactive Laboratory Modules for Computer Science," was given July 27-August 6, 1998, at Illinois State University at Normal. Each participant was…

Light Scattering based detection of food pathogens

USDA-ARS?s Scientific Manuscript database

The current methods for detecting foodborne pathogens are mostly destructive (i.e., samples need to be pretreated), and require time, personnel, and laboratories for analyses. Optical methods including light scattering based techniques have gained a lot of attention recently due to its their rapid a...

Characterizing Materials Sources and Sinks; Current Approaches: Part II. Chemical and Physical Characterization

EPA Science Inventory

The paper discusses methods for characterizing chemical emissions from material sources, including laboratory, dynamic chamber, and full-scale studies. Indoor sources and their interaction with sinks play a major role in determining indoor air quality (IAQ). Techniques for evalua...

Tissue Doppler and strain imaging: anything left in the echo-lab?

PubMed Central

Citro, Rodolfo; Bossone, Eduardo; Kuersten, Bettina; Gregorio, Giovanni; Salustri, Alessandro

2008-01-01

Medline research indicates that an increasing number of manuscripts have been published in the last decade claiming, the feasibility and the potential clinical role of tissue Doppler and strain/strain rate imaging. However, despite this amount of scientific evidence, these technologies are still confined to dedicated, high-tech, research-oriented echocardiography laboratories. In this review we have critically evaluated these techniques, analysing their physical principles, the technical problems related to their current clinical application, and the future perspectives. Finally, this review explores the reasons why these technologies are still defined "new technologies" and the impact of their implementation on the current clinical activity of an echocardiography laboratory. PMID:18973677

Assisted reproduction techniques in the horse.

PubMed

Hinrichs, Katrin

2012-01-01

This paper reviews current equine assisted reproduction techniques. Embryo transfer is the most common equine ART, but is still limited by the inability to superovulate mares effectively. Immature oocytes may be recovered by transvaginal ultrasound-guided aspiration of immature follicles, or from ovaries postmortem, and can be effectively matured in vitro. Notably, the in vivo-matured oocyte may be easily recovered from the stimulated preovulatory follicle. Standard IVF is still not repeatable in the horse; however, embryos and foals can be produced by surgical transfer of mature oocytes to the oviducts of inseminated recipient mares or via intracytoplasmic sperm injection (ICSI). Currently, ICSI and in vitro embryo culture are routinely performed by only a few laboratories, but reported blastocyst development rates approach those found after bovine IVF (i.e. 25%-35%). Nuclear transfer can be relatively efficient (up to 26% live foal rate per transferred embryo), but few laboratories are working in this area. Equine blastocysts may be biopsied via micromanipulation, with normal pregnancy rates after biopsy, and accurate genetic analysis. Equine expanded blastocysts may be vitrified after collapsing them via micromanipulation, with normal pregnancy rates after warming and transfer. Many of these recently developed techniques are now in clinical use.

Mating competitiveness of sterile genetic sexing strain males (GAMA) under laboratory and semi-field conditions: Steps towards the use of the Sterile Insect Technique to control the major malaria vector Anopheles arabiensis in South Africa.

PubMed

Munhenga, Givemore; Brooke, Basil D; Gilles, Jeremie R L; Slabbert, Kobus; Kemp, Alan; Dandalo, Leonard C; Wood, Oliver R; Lobb, Leanne N; Govender, Danny; Renke, Marius; Koekemoer, Lizette L

2016-03-02

Anopheles arabiensis Patton is primarily responsible for malaria transmission in South Africa after successful suppression of other major vector species using indoor spraying of residual insecticides. Control of An. arabiensis using current insecticide based approaches is proving difficult owing to the development of insecticide resistance, and variable feeding and resting behaviours. The use of the sterile insect technique as an area-wide integrated pest management system to supplement the control of An. arabiensis was proposed for South Africa and is currently under investigation. The success of this technique is dependent on the ability of laboratory-reared sterile males to compete with wild males for mates. As part of the research and development of the SIT technique for use against An. arabiensis in South Africa, radio-sensitivity and mating competitiveness of a local An. arabiensis sexing strain were assessed. The optimal irradiation dose inducing male sterility without compromising mating vigour was tested using Cobalt 60 irradiation doses ranging from 70-100 Gy. Relative mating competitiveness of sterile laboratory-reared males (GAMA strain) compared to fertile wild-type males (AMAL strain) for virgin wild-type females (AMAL) was investigated under laboratory and semi-field conditions using large outdoor cages. Three different sterile male to fertile male to wild-type female ratios were evaluated [1:1:1, 5:1:1 and 10:1:1 (sterile males: fertile, wild-type males: fertile, wild-type females)]. Irradiation at the doses tested did not affect adult emergence but had a moderate effect on adult survivorship and mating vigour. A dose of 75 Gy was selected for the competitiveness assays. Mating competitiveness experiments showed that irradiated GAMA male mosquitoes are a third as competitive as their fertile AMAL counterparts under semi-field conditions. However, they were not as competitive under laboratory conditions. An inundative ratio of 10:1 induced the highest sterility in the representative wild-type population, with potential to effectively suppress reproduction. Laboratory-reared and sterilised GAMA male An. arabiensis at a release ratio of 3:1 (3 sterile males to 1 wild, fertile male) can successfully compete for insemination of wild-type females. These results will be used to inform subsequent small-scale pilot field releases in South Africa.

NASA CR-2120 - Summary of nondestructive testing theory and practice

NASA Technical Reports Server (NTRS)

Meister, R. P.

1974-01-01

This is a familiarization report of nondestructive testing (ndt) prepared by staff of the Battelle Columbus Laboratories on a NASA contract. There is a short introduction, a chapter on applicability of ndt which is illustrated with examples of typical defects and includes tables comparing the characteristics, interrelationships, and costs of the different techniques. There are chapters dealing with penetrants, magnetic particle radiography, ultrasonics, and eddy currents. New techniques are described.

[Latest development in mass spectrometry for clinical application].

PubMed

Takino, Masahiko

2013-09-01

Liquid chromatography-tandem mass spectrometry (LC-MS/MS) has seen enormous growth in special clinical chemistry laboratories. It significantly increases the analytic potential in clinical chemistry, especially in the field of low molecular weight biomarker analysis. This review summarizes the state of the art in mass spectrometry and related techniques for clinical application with a main focus on recent developments in LC-MS. Current trends in ionization techniques, automated online sample preparation techniques coupled with LC-MS, and ion mobility spectrometry are discussed. Emerging mass spectrometric approaches complementary to LC-MS are discussed as well.

Acoustic impulse response method as a source of undergraduate research projects and advanced laboratory experiments.

PubMed

Robertson, W M; Parker, J M

2012-03-01

A straightforward and inexpensive implementation of acoustic impulse response measurement is described utilizing the signal processing technique of coherent averaging. The technique is capable of high signal-to-noise measurements with personal computer data acquisition equipment, an amplifier/speaker, and a high quality microphone. When coupled with simple waveguide test systems fabricated from commercial PVC plumbing pipe, impulse response measurement has proven to be ideal for undergraduate research projects-often of publishable quality-or for advanced laboratory experiments. The technique provides important learning objectives for science or engineering students in areas such as interfacing and computer control of experiments; analog-to-digital conversion and sampling; time and frequency analysis using Fourier transforms; signal processing; and insight into a variety of current research areas such as acoustic bandgap materials, acoustic metamaterials, and fast and slow wave manipulation. © 2012 Acoustical Society of America

An Undergraduate Experiment on Nuclear Lifetime Measurement Using the Doppler Effect

ERIC Educational Resources Information Center

Campbell, J. L.; And Others

1972-01-01

While designed for a senior undergraduate laboratory, the experiment illustrates the principles involved in the various Doppler techniques currently used in nuclear lifetime studies and demonstrates the versatility of the Ge(Li) detector in applications other than direct energy or intensity measurement. (Author/TS)

USDA-ARS Hydrology Laboratory MISWG Hydrology Workshop

NASA Technical Reports Server (NTRS)

Jackson, T. J.

1982-01-01

Current research being conducted in remote sensing techniques for measuring hydrologic parameters and variables deals with runoff curve numbers (CN), evapotranspiration (ET), and soil moisture. The CN and ET research utilizes visible and infrared measurements. Soil moisture investigations focus on the microwave region of the electromagnetic spectrum.

Nonpharmacological, blood conservation techniques for preventing neonatal anemia--effective and promising strategies for reducing transfusion.

PubMed

Carroll, Patrick D; Widness, John A

2012-08-01

The development of anemia after birth in very premature, critically ill newborn infants is a universal well-described phenomenon. Although preventing anemia in this population, along with efforts to establish optimal red blood cell (RBC) transfusion and pharmacologic therapy continue to be actively investigated, the present review focuses exclusively on nonpharmacological approaches to the prevention and treatment of neonatal anemia. We begin with an overview of topics relevant to nonpharmacological techniques. These topics include neonatal and fetoplacental hemoglobin levels and blood volumes, clinical and laboratory practices applied in critically ill neonates, and current RBC transfusion practice guidelines. This is followed by a discussion of the most effective and promising nonpharmacological blood conservation strategies and techniques. Fortunately, many of these techniques are feasible in most neonatal intensive care units. When applied together, these techniques are more effective than existing pharmacotherapies in significantly decreasing neonatal RBC transfusions. They include increasing hemoglobin endowment and circulating blood volume at birth; removing less blood for laboratory testing; and optimizing nutrition. Copyright © 2012 Elsevier Inc. All rights reserved.

Development of Gold Standard Ion-Selective Electrode-Based Methods for Fluoride Analysis

PubMed Central

Martínez-Mier, E.A.; Cury, J.A.; Heilman, J.R.; Katz, B.P.; Levy, S.M.; Li, Y.; Maguire, A.; Margineda, J.; O’Mullane, D.; Phantumvanit, P.; Soto-Rojas, A.E.; Stookey, G.K.; Villa, A.; Wefel, J.S.; Whelton, H.; Whitford, G.M.; Zero, D.T.; Zhang, W.; Zohouri, V.

2011-01-01

Background/Aims: Currently available techniques for fluoride analysis are not standardized. Therefore, this study was designed to develop standardized methods for analyzing fluoride in biological and nonbiological samples used for dental research. Methods A group of nine laboratories analyzed a set of standardized samples for fluoride concentration using their own methods. The group then reviewed existing analytical techniques for fluoride analysis, identified inconsistencies in the use of these techniques and conducted testing to resolve differences. Based on the results of the testing undertaken to define the best approaches for the analysis, the group developed recommendations for direct and microdiffusion methods using the fluoride ion-selective electrode. Results Initial results demonstrated that there was no consensus regarding the choice of analytical techniques for different types of samples. Although for several types of samples, the results of the fluoride analyses were similar among some laboratories, greater differences were observed for saliva, food and beverage samples. In spite of these initial differences, precise and true values of fluoride concentration, as well as smaller differences between laboratories, were obtained once the standardized methodologies were used. Intraclass correlation coefficients ranged from 0.90 to 0.93, for the analysis of a certified reference material, using the standardized methodologies. Conclusion The results of this study demonstrate that the development and use of standardized protocols for F analysis significantly decreased differences among laboratories and resulted in more precise and true values. PMID:21160184

Non-destructive mapping of grain orientations in 3D by laboratory X-ray microscopy

PubMed Central

McDonald, S. A.; Reischig, P.; Holzner, C.; Lauridsen, E. M.; Withers, P. J.; Merkle, A. P.; Feser, M.

2015-01-01

The ability to characterise crystallographic microstructure, non-destructively and in three-dimensions, is a powerful tool for understanding many aspects related to damage and deformation mechanisms in polycrystalline materials. To this end, the technique of X-ray diffraction contrast tomography (DCT) using monochromatic synchrotron and polychromatic laboratory X-ray sources has been shown to be capable of mapping crystal grains and their orientations non-destructively in 3D. Here we describe a novel laboratory-based X-ray DCT modality (LabDCT), enabling the wider accessibility of the DCT technique for routine use and in-depth studies of, for example, temporal changes in crystallographic grain structure non-destructively over time through ‘4D’ in situ time-lapse studies. The capability of the technique is demonstrated by studying a titanium alloy (Ti-β21S) sample. In the current implementation the smallest grains that can be reliably detected are around 40 μm. The individual grain locations and orientations are reconstructed using the LabDCT method and the results are validated against independent measurements from phase contrast tomography and electron backscatter diffraction respectively. Application of the technique promises to provide important insights related to the roles of recrystallization and grain growth on materials properties as well as supporting 3D polycrystalline modelling of materials performance. PMID:26494523

A Laboratory Manual for Stepwise Cerebral White Matter Fiber Dissection.

PubMed

Koutsarnakis, Christos; Liakos, Faidon; Kalyvas, Aristotelis V; Sakas, Damianos E; Stranjalis, George

2015-08-01

White matter fiber dissection is an important method in acquiring a thorough neuroanatomic knowledge for surgical practice. Previous studies have definitely improved our understanding of intrinsic brain anatomy and emphasized on the significance of this technique in modern neurosurgery. However, current literature lacks a complete and concentrated laboratory guide about the entire dissection procedure. Hence, our primary objective is to introduce a detailed laboratory manual for cerebral white matter dissection by highlighting consecutive dissection steps, and to stress important technical comments facilitating this complex procedure. Twenty adult, formalin-fixed cerebral hemispheres were included in the study. Ten specimens were dissected in the lateromedial and 10 in the mediolateral direction, respectively, using the fiber dissection technique and the microscope. Eleven and 8 consecutive and distinctive dissection steps are recommended for the lateromedial and mediolateral dissection procedures, respectively. Photographs highlighting various anatomic landmarks accompany every step. Technical recommendations, facilitating the dissection process, are also indicated. The fiber dissection technique, although complex and time consuming, offers a three-dimensional knowledge of intrinsic brain anatomy and architecture, thus improving both the quality of microneurosurgery and the patient's standard of care. The present anatomic study provides a thorough dissection manual to those who study brain anatomy using this technique. Copyright © 2015 Elsevier Inc. All rights reserved.

Non-destructive mapping of grain orientations in 3D by laboratory X-ray microscopy

NASA Astrophysics Data System (ADS)

McDonald, S. A.; Reischig, P.; Holzner, C.; Lauridsen, E. M.; Withers, P. J.; Merkle, A. P.; Feser, M.

2015-10-01

The ability to characterise crystallographic microstructure, non-destructively and in three-dimensions, is a powerful tool for understanding many aspects related to damage and deformation mechanisms in polycrystalline materials. To this end, the technique of X-ray diffraction contrast tomography (DCT) using monochromatic synchrotron and polychromatic laboratory X-ray sources has been shown to be capable of mapping crystal grains and their orientations non-destructively in 3D. Here we describe a novel laboratory-based X-ray DCT modality (LabDCT), enabling the wider accessibility of the DCT technique for routine use and in-depth studies of, for example, temporal changes in crystallographic grain structure non-destructively over time through ‘4D’ in situ time-lapse studies. The capability of the technique is demonstrated by studying a titanium alloy (Ti-β21S) sample. In the current implementation the smallest grains that can be reliably detected are around 40 μm. The individual grain locations and orientations are reconstructed using the LabDCT method and the results are validated against independent measurements from phase contrast tomography and electron backscatter diffraction respectively. Application of the technique promises to provide important insights related to the roles of recrystallization and grain growth on materials properties as well as supporting 3D polycrystalline modelling of materials performance.

Non-destructive mapping of grain orientations in 3D by laboratory X-ray microscopy.

PubMed

McDonald, S A; Reischig, P; Holzner, C; Lauridsen, E M; Withers, P J; Merkle, A P; Feser, M

2015-10-23

The ability to characterise crystallographic microstructure, non-destructively and in three-dimensions, is a powerful tool for understanding many aspects related to damage and deformation mechanisms in polycrystalline materials. To this end, the technique of X-ray diffraction contrast tomography (DCT) using monochromatic synchrotron and polychromatic laboratory X-ray sources has been shown to be capable of mapping crystal grains and their orientations non-destructively in 3D. Here we describe a novel laboratory-based X-ray DCT modality (LabDCT), enabling the wider accessibility of the DCT technique for routine use and in-depth studies of, for example, temporal changes in crystallographic grain structure non-destructively over time through '4D' in situ time-lapse studies. The capability of the technique is demonstrated by studying a titanium alloy (Ti-β21S) sample. In the current implementation the smallest grains that can be reliably detected are around 40 μm. The individual grain locations and orientations are reconstructed using the LabDCT method and the results are validated against independent measurements from phase contrast tomography and electron backscatter diffraction respectively. Application of the technique promises to provide important insights related to the roles of recrystallization and grain growth on materials properties as well as supporting 3D polycrystalline modelling of materials performance.

INNOVATIONS IN EQUIPMENT AND TECHNIQUES FOR THE BIOLOGY TEACHING LABORATORY.

ERIC Educational Resources Information Center

BARTHELEMY, RICHARD E.; AND OTHERS

LABORATORY TECHNIQUES AND EQUIPMENT APPROPRIATE FOR TEACHING BIOLOGICAL SCIENCE CURRICULUM STUDY BIOLOGY ARE EMPHASIZED. MAJOR CATEGORIES INCLUDE (1) LABORATORY FACILITIES, (2) EQUIPMENT AND TECHNIQUES FOR CULTURE OF MICRO-ORGANISMS, (3) LABORATORY ANIMALS AND THEIR HOUSING, (4) TECHNIQUES FOR STUDYING PLANT GROWTH, (5) TECHNIQUES FOR STUDYING…

Scientific data bases on a VAX-11/780 running VMS

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

Benkovitz, C.M.; Tichler, J.L.

At Brookhaven National Laboratory several current projects are developing and applying data management techniques to compile, analyze and distribute scientific data sets that are the result of various multi institutional experiments and data gathering projects. This paper will present an overview of a few of these data management projects.

Identification of particle-laden flow features from wavelet decomposition

NASA Astrophysics Data System (ADS)

Jackson, A.; Turnbull, B.

2017-12-01

A wavelet decomposition based technique is applied to air pressure data obtained from laboratory-scale powder snow avalanches. This technique is shown to be a powerful tool for identifying both repeatable and chaotic features at any frequency within the signal. Additionally, this technique is demonstrated to be a robust method for the removal of noise from the signal as well as being capable of removing other contaminants from the signal. Whilst powder snow avalanches are the focus of the experiments analysed here, the features identified can provide insight to other particle-laden gravity currents and the technique described is applicable to a wide variety of experimental signals.

Time-resolved acoustic emission tomography in the laboratory: tracking localised damage in rocks

NASA Astrophysics Data System (ADS)

Brantut, N.

2017-12-01

Over the past three decades, there has been tremendous technological developments of laboratory equipment and studies using acoustic emission and ultrasonic monitoring of rock samples during deformation. Using relatively standard seismological techniques, acoustic emissions can be detected, located in space and time, and source mechanisms can be obtained. In parallel, ultrasonic velocities can be measured routinely using standard pulse-receiver techniques.Despite these major developments, current acoustic emission and ultrasonic monitoring systems are typically used separately, and the poor spatial coverage of acoustic transducers precludes performing active 3D tomography in typical laboratory settings.Here, I present an algorithm and software package that uses both passive acoustic emission data and active ultrasonic measurements to determine acoustic emission locations together with the 3D, anisotropic P-wave structure of rock samples during deformation. The technique is analogous to local earthquake tomography, but tailored to the specificities of small scale laboratory tests. The fast marching method is employed to compute the forward problem. The acoustic emission locations and the anisotropic P-wave field are jointly inverted using the Quasi-Newton method.The method is used to track the propagation of compaction bands in a porous sandstone deformed in the ductile, cataclastic flow regime under triaxial stress conditions. Near the yield point, a compaction front forms at one end of the sample, and slowly progresses towards the other end. The front is illuminated by clusters of Acoustic Emissions, and leaves behind a heavily damaged material where the P-wave speed has dropped by up to 20%.The technique opens new possibilities to track in-situ strain localisation and damage around laboratory faults, and preliminary results on quasi-static rupture in granite will be presented.

Feasibility of a Fieldable Mass Spectrometer FY 2015 Year-end Report

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

Barinaga, Charles J.; Hager, George J.; Hoegg, Edward D.

Currently, the International Atomic Energy Agency (IAEA) monitors the production of enriched uranium hexafluoride (UF 6) at declared facilities by collecting a few grams of product in sample tubes that are then sent to central laboratories for processing and isotope ratio analysis by thermal ionization mass spectrometry. Analysis of results may not be available for some time after collection. In addition, new shipping regulations will make it more difficult to transport this amount of UF 6 to a laboratory. The IAEA is interested in an isotope ratio technique for uranium in UF 6 that can be moved to and operatedmore » at the enrichment facility itself. This report covers the tasks and activities of the Feasibility of a Fieldable Mass Spectrometer Project for FY 2015, which investigates the feasibility of an in-field isotope ratio technique— the forward deployment of a technique to the non-laboratory situation of a protected room with power and heat at the facility of interest. A variety of nontraditional elemental ionization techniques were considered. It was determined that only two of these should be moved forward for testing with the candidate in-field mass spectrometer and with the adsorbed UF 6 sample types.« less

Application of gamma-ray radiography and gravimetric measurements after accelerated corrosion tests of steel embedded in mortar

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

Duffó, Gustavo, E-mail: duffo@cnea.gov.ar; Consejo Nacional de Investigaciones Científicas y Técnicas; Universidad Nacional de San Martín, Av. Gral. Paz 1499, 1650 San Martín, Buenos Aires

2015-08-15

The accelerated corrosion by the impressed current technique is widely used in studies of concrete durability since it has the advantage that tests can be carried out within reasonable periods of time. In the present work the relationship between the applied current density and the resulting damage on the reinforcing steel, by applying optical microscopy, scanning electron microscopy, gamma-ray radiography and gravimetric measurements, was studied by means of the implementation of accelerated corrosion tests on reinforced mortar. The results show that the efficiency of the applied current is between 1 and 77%, regardless of the applied current density, the water/cementmore » ratio and the mortar cover depth of the specimens. The results show the applicability of the gamma-ray radiography technique to detect localized corrosion of steel rebars in laboratory specimens.« less

Psychobiological responses to critically evaluated multitasking.

PubMed

Wetherell, Mark A; Craw, Olivia; Smith, Kenny; Smith, Michael A

2017-12-01

In order to understand psychobiological responses to stress it is necessary to observe how people react to controlled stressors. A range of stressors exist for this purpose; however, laboratory stressors that are representative of real life situations provide more ecologically valid opportunities for assessing stress responding. The current study assessed psychobiological responses to an ecologically valid laboratory stressor involving multitasking and critical evaluation. The stressor elicited significant increases in psychological and cardiovascular stress reactivity; however, no cortisol reactivity was observed. Other socially evaluative laboratory stressors that lead to cortisol reactivity typically require a participant to perform tasks that involve verbal responses, whilst standing in front of evaluative others. The current protocol contained critical evaluation of cognitive performance; however, this was delivered from behind a seated participant. The salience of social evaluation may therefore be related to the response format of the task and the method of evaluation. That is, the current protocol did not involve the additional vulnerability associated with in person, face-to-face contact, and verbal delivery. Critical evaluation of multitasking provides an ecologically valid technique for inducing laboratory stress and provides an alternative tool for assessing psychological and cardiovascular reactivity. Future studies could additionally use this paradigm to investigate those components of social evaluation necessary for eliciting a cortisol response.

KSC-06pd0633

NASA Image and Video Library

2006-04-03

KENNEDY SPACE CENTER, FLA. -- Marc Reagan (left) and Bill Todd, NASA Extreme Environment Mission Operations (NEEMO) project leads, have left the current NEEMO team in the National Oceanic and Atmospheric Administration (NOAA) Aquarius Underwater Laboratory to start their 17-day mission. The team comprises astronauts Dave Williams (team leader), Nicole Stott and Ron Garan, plus Dr. Tim Broderick of the University of Cincinnati. The astronauts are testing space medicine concepts and moon-walking techniques. The undersea laboratory is situated three miles off Key Largo in the Florida Keys National Marine Sanctuary, anchored 62 feet below the surface.

Apparatus and methodology for fire gas characterization by means of animal exposure

NASA Technical Reports Server (NTRS)

Marcussen, W. H.; Hilado, C. J.; Furst, A.; Leon, H. A.; Kourtides, D. A.; Parker, J. A.; Butte, J. C.; Cummins, J. M.

1976-01-01

While there is a great deal of information available from small-scale laboratory experiments and for relatively simple mixtures of gases, considerable uncertainty exists regarding appropriate bioassay techniques for the complex mixture of gases generated in full-scale fires. Apparatus and methodology have been developed based on current state of the art for determining the effects of fire gases in the critical first 10 minutes of a full-scale fire on laboratory animals. This information is presented for its potential value and use while further improvements are being made.

Artificial intelligence in the materials processing laboratory

NASA Technical Reports Server (NTRS)

Workman, Gary L.; Kaukler, William F.

1990-01-01

Materials science and engineering provides a vast arena for applications of artificial intelligence. Advanced materials research is an area in which challenging requirements confront the researcher, from the drawing board through production and into service. Advanced techniques results in the development of new materials for specialized applications. Hand-in-hand with these new materials are also requirements for state-of-the-art inspection methods to determine the integrity or fitness for service of structures fabricated from these materials. Two problems of current interest to the Materials Processing Laboratory at UAH are an expert system to assist in eddy current inspection of graphite epoxy components for aerospace and an expert system to assist in the design of superalloys for high temperature applications. Each project requires a different approach to reach the defined goals. Results to date are described for the eddy current analysis, but only the original concepts and approaches considered are given for the expert system to design superalloys.

UF6 Density and Mass Flow Measurements for Enrichment Plants using Acoustic Techniques

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

Good, Morris S.; Smith, Leon E.; Warren, Glen A.

A key enabling capability for enrichment plant safeguards being considered by the International Atomic Energy Agency (IAEA) is high-accuracy, noninvasive, unattended measurement of UF6 gas density and mass flow rate. Acoustic techniques are currently used to noninvasively monitor gas flow in industrial applications; however, the operating pressures at gaseous centrifuge enrichment plants (GCEPs) are roughly two orders magnitude below the capabilities of commercial instrumentation. Pacific Northwest National Laboratory is refining acoustic techniques for estimating density and mass flow rate of UF6 gas in scenarios typical of GCEPs, with the goal of achieving 1% measurement accuracy. Proof-of-concept laboratory measurements using amore » surrogate gas for UF6 have demonstrated signatures sensitive to gas density at low operating pressures such as 10–50 Torr, which were observed over the background acoustic interference. Current efforts involve developing a test bed for conducting acoustic measurements on flowing SF6 gas at representative flow rates and pressures to ascertain the viability of conducting gas flow measurements under these conditions. Density and flow measurements will be conducted to support the evaluation. If successful, the approach could enable an unattended, noninvasive approach to measure mass flow in unit header pipes of GCEPs.« less

Implementation of advanced fiber optic and piezoelectric sensors : fabrication and laboratory testing of piezoelectric ceramic-polymer composite sensors for weigh-in-motion systems.

DOT National Transportation Integrated Search

1999-02-01

Weigh-in-motion (WIM) systems might soon replace the conventional techniques used to enforce : weight restrictions for large vehicles on highways. Currently WIM systems use a piezoelectric : polymer sensor that produces a voltage proportional to an a...

Drive Beam Shaping and Witness Bunch Generation for the Plasma Wakefield Accelerator

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

England, R. J.; Frederico, J.; Hogan, M. J.

2010-11-04

High transformer ratio operation of the plasma wake field accelerator requires a tailored drive beam current profile followed by a short witness bunch. We discuss techniques for generating the requisite dual bunches and for obtaining the desired drive beam profile, with emphasis on the FACET experiment at SLAC National Accelerator Laboratory.

Proteomics in the Classroom: An Investigative Study of Proteins in Microorganisms

ERIC Educational Resources Information Center

Benskin, Jon; Chen, Sixue

2012-01-01

As advances in biotechnology and molecular biology rapidly expand in research settings, it is vital that we continue to prepare high school students to enter and thrive in those modern laboratories. This multistep, inquiry-based lab describes highly adaptable methods to teach students not only current molecular techniques and technologies, but…

Strategies in Ebola virus disease (EVD) diagnostics at the point of care.

PubMed

Coarsey, Chad T; Esiobu, Nwadiuto; Narayanan, Ramswamy; Pavlovic, Mirjana; Shafiee, Hadi; Asghar, Waseem

2017-11-01

Ebola virus disease (EVD) is a devastating, highly infectious illness with a high mortality rate. The disease is endemic to regions of Central and West Africa, where there is limited laboratory infrastructure and trained staff. The recent 2014 West African EVD outbreak has been unprecedented in case numbers and fatalities, and has proven that such regional outbreaks can become a potential threat to global public health, as it became the source for the subsequent transmission events in Spain and the USA. The urgent need for rapid and affordable means of detecting Ebola is crucial to control the spread of EVD and prevent devastating fatalities. Current diagnostic techniques include molecular diagnostics and other serological and antigen detection assays; which can be time-consuming, laboratory-based, often require trained personnel and specialized equipment. In this review, we discuss the various Ebola detection techniques currently in use, and highlight the potential future directions pertinent to the development and adoption of novel point-of-care diagnostic tools. Finally, a case is made for the need to develop novel microfluidic technologies and versatile rapid detection platforms for early detection of EVD.

How do laboratory embryo transfer techniques affect IVF outcomes? A review of current literature.

PubMed

Sigalos, George; Triantafyllidou, Olga; Vlahos, Nikos

2017-04-01

Over the last few years, many studies have focused on embryo selection methods, whereas little attention has been given to the standardization of the procedure of embryo transfer. In this review, several parameters of the embryo transfer procedure are examined, such as the: (i) culture medium volume and loading technique; (ii) syringe and catheters used for embryo transfer; (iii) viscosity and composition of the embryo transfer medium; (iv) environment of embryo culture; (v) timing of embryo transfer; (vi) and standardization of the embryo transfer techniques. The aim of this manuscript is to review these factors and compare the existing embryo transfer techniques and highlight the need for better embryo transfer standardization.

Millimeter and Sub-millimeter High Resolution Spectroscopy: New Frontiers with ALMA

NASA Astrophysics Data System (ADS)

Ziurys, Lucy M.

2016-06-01

It is becoming increasingly clear that new laboratory data will be critical for the next decade of observations with the Atacama Large Millimeter Array (ALMA). The high spatial resolution offered by ALMA will probe new regions of molecular complexity, including the inner envelopes of evolved stars, regions dominated by UV radiation, and the densest cores of molecular clouds. New molecular lines will be discovered in the wide wavelength range covered by the ALMA bands, and high resolution, gas-phase spectroscopy are needed to provide crucial “rest frequencies.” In particular, highly accurate methods that measure millimeter and sub-millimeter rotational transitions, such as direct absorption and Fourier transform mm-wave techniques, are important, especially when coupled to exotic molecular production schemes. Recent ALMA studies of SH+ and larger organic species have already demonstrated the need for laboratory measurements. New laboratory work will likely be required for circumstellar refractory molecules, radicals and ions generated near photon-dominated regions (PDRs), and large, organic-type species. This talk will give an overview of current contributions of laboratory spectroscopy to ALMA observations, summarize relevant spectroscopic techniques, and provide input into future prospects and directions.

Current Source Based on H-Bridge Inverter with Output LCL Filter

NASA Astrophysics Data System (ADS)

Blahnik, Vojtech; Talla, Jakub; Peroutka, Zdenek

2015-09-01

The paper deals with a control of current source with an LCL output filter. The controlled current source is realized as a single-phase inverter and output LCL filter provides low ripple of output current. However, systems incorporating LCL filters require more complex control strategies and there are several interesting approaches to the control of this type of converter. This paper presents the inverter control algorithm, which combines model based control with a direct current control based on resonant controllers and single-phase vector control. The primary goal is to reduce the current ripple and distortion under required limits and provides fast and precise control of output current. The proposed control technique is verified by measurements on the laboratory model.

Confidence Intervals for Laboratory Sonic Boom Annoyance Tests

NASA Technical Reports Server (NTRS)

Rathsam, Jonathan; Christian, Andrew

2016-01-01

Commercial supersonic flight is currently forbidden over land because sonic booms have historically caused unacceptable annoyance levels in overflown communities. NASA is providing data and expertise to noise regulators as they consider relaxing the ban for future quiet supersonic aircraft. One deliverable NASA will provide is a predictive model for indoor annoyance to aid in setting an acceptable quiet sonic boom threshold. A laboratory study was conducted to determine how indoor vibrations caused by sonic booms affect annoyance judgments. The test method required finding the point of subjective equality (PSE) between sonic boom signals that cause vibrations and signals not causing vibrations played at various amplitudes. This presentation focuses on a few statistical techniques for estimating the interval around the PSE. The techniques examined are the Delta Method, Parametric and Nonparametric Bootstrapping, and Bayesian Posterior Estimation.

Digital enhancement of X-rays for NDT

NASA Technical Reports Server (NTRS)

Butterfield, R. L.

1980-01-01

Report is "cookbook" for digital processing of industrial X-rays. Computer techniques, previously used primarily in laboratory and developmental research, have been outlined and codified into step by step procedures for enhancing X-ray images. Those involved in nondestructive testing should find report valuable asset, particularly is visual inspection is method currently used to process X-ray images.

Status and Perspectives of the INFN-LNS In-Flight Fragment Separator

NASA Astrophysics Data System (ADS)

Russotto, P.; Calabretta, L.; Cardella, G.; Cosentino, G.; De Filippo, E.; Gnoffo, B.; La Cognata, M.; Martorana, N. S.; Pagano, E. V.; Pizzone, R. G.; Quattrocchi, L.; Romano, S.; Russo, A. D.; Santonocito, D.

2018-05-01

In the last 15 years the FRIBs@LNS facility has successfully produced Radioactive Ion Beams using the In-Flight technique. We report on the current status and future perspectives opened by FRAISE, a new fragment separator that will be build in connection with the upgrade of Superconducting Cyclotron of the INFN-LNS laboratories.

qHNMR Analysis of Purity of Common Organic Solvents--An Undergraduate Quantitative Analysis Laboratory Experiment

ERIC Educational Resources Information Center

Bell, Peter T.; Whaley, W. Lance; Tochterman, Alyssa D.; Mueller, Karl S.; Schultz, Linda D.

2017-01-01

NMR spectroscopy is currently a premier technique for structural elucidation of organic molecules. Quantitative NMR (qNMR) methodology has developed more slowly but is now widely accepted, especially in the areas of natural product and medicinal chemistry. However, many undergraduate students are not routinely exposed to this important concept.…

Analysis of a Digital Technique for Frequency Transposition of Speech.

DTIC Science & Technology

1985-09-01

scaled excitation function drives the vocal tract model. In a phone interview with James Kaiser of Bell Laboratories, he mentioned that current thinking...is processed using the Fast Fourier Transform (FFT) and then low pass filtered if desired. mAbe (Pb) FFT LPF- nih ~a s5ee.. S. 4Nrf#Nr Flow Chart for

A Hot-Wire Method Based Thermal Conductivity Measurement Apparatus for Teaching Purposes

ERIC Educational Resources Information Center

Alvarado, S.; Marin, E.; Juarez, A. G.; Calderon, A.; Ivanov, R.

2012-01-01

The implementation of an automated system based on the hot-wire technique is described for the measurement of the thermal conductivity of liquids using equipment easily available in modern physics laboratories at high schools and universities (basically a precision current source and a voltage meter, a data acquisition card, a personal computer…

Use and Acceptance of Information and Communication Technology Among Laboratory Science Students

NASA Astrophysics Data System (ADS)

Barnes, Brenda C.

Online and blended learning platforms are being promoted within laboratory science education under the assumption that students have the necessary skills to navigate online and blended learning environments. Yet little research has examined the use of information and communication technology (ICT) among the laboratory science student population. The purpose of this correlational, survey research study was to explore factors that affect use and acceptance of ICT among laboratory science students through the theoretical lens of the unified theory of acceptance and use of technology (UTAUT) model. An electronically delivered survey drew upon current students and recent graduates (within 2 years) of accredited laboratory science training programs. During the 4 week data collection period, 168 responses were received. Results showed that the UTAUT model did not perform well within this study, explaining 25.2% of the variance in use behavior. A new model incorporating attitudes toward technology and computer anxiety as two of the top variables, a model significantly different from the original UTAUT model, was developed that explained 37.0% of the variance in use behavior. The significance of this study may affect curriculum design of laboratory science training programs wanting to incorporate more teaching techniques that use ICT-based educational delivery, and provide more options for potential students who may not currently have access to this type of training.

Innovations in Delta Differential One-Way Range: from Viking to Mars Science Laboratory

NASA Technical Reports Server (NTRS)

Border, James S.

2009-01-01

The Deep Space Network has provided the capability for very-long-baseline interferometry measurements in support of spacecraft navigation since the late 1970s. Both system implementation and the importance of such measurements to flight projects have evolved significantly over the past three decades. Innovations introduced through research and development programs have led to much better performance. This paper provides an overview of the development and use of interferometric tracking techniques in the DSN starting with the Viking era and continuing with a description of the current system and its planned use to support Mars Science Laboratory.

Application of selection techniques to electric-propulsion options on an advanced synchronous satellite

NASA Technical Reports Server (NTRS)

Holcomb, L. B.; Degrey, S. P.

1973-01-01

This paper addresses the comparison of several candidate auxiliary-propulsion systems and system combinations for an advanced synchronous satellite. Economic selection techniques, evolved at the Jet Propulsion Laboratory, are used as a basis for system option comparisons. Electric auxiliary-propulsion types considered include pulsed plasma and ion bombardment, with hydrazine systems used as a state-of-the-art reference. Current as well as projected electric-propulsion system performance data are used, as well as projected hydrazine system costs resulting from NASA standardization program projections.

Reliability of clinical diagnosis and laboratory testing techniques currently used for identification of canine parvovirus enteritis in clinical settings

PubMed Central

FAZ, Mirna; MARTÍNEZ, José Simón; QUIJANO-HERNÁNDEZ, Israel; FAJARDO, Raúl

2016-01-01

Canine parvovirus type 2 (CPV-2) is the main etiological agent of viral enteritis in dogs. Actually in literature, CPV-2 has been reported with clinical signs that vary from the classical disease, and immunochromatography test and PCR technique have been introduced to veterinary hospitals to confirm CPV-2 diagnosis and other infections. However, the reliability of these techniques has been poorly analyzed. In this study, we evaluated the sensitivity and specificity of veterinary clinical diagnosis, immunochromatography test and PCR technique. Our data indicate that variations in the clinical signs of CPV-2 complicate the gathering of an appropriate diagnosis; and immunochromatography test and PCR technique do not have adequate sensitivity to diagnose positive cases. PMID:27818461

Nondestructive techniques for characterizing mechanical properties of structural materials: An overview

NASA Technical Reports Server (NTRS)

Vary, A.; Klima, S. J.

1985-01-01

An overview of nondestructive evaluation (NDE) is presented to indicate the availability and application potentials of techniques for quantitative characterization of the mechanical properties of structural materials. The purpose is to review NDE techniques that go beyond the usual emphasis on flaw detection and characterization. Discussed are current and emerging NDE techniques that can verify and monitor entrinsic properties (e.g., tensile, shear, and yield strengths; fracture toughness, hardness, ductility; elastic moduli) and underlying microstructural and morphological factors. Most of the techniques described are, at present, neither widely applied nor widely accepted in commerce and industry because they are still emerging from the laboratory. The limitations of the techniques may be overcome by advances in applications research and instrumentation technology and perhaps by accommodations for their use in the design of structural parts.

A Laboratory Experiment to Measure the Built-In Potential of a P-N Junction by a Photosaturation Method

ERIC Educational Resources Information Center

Ikram, I. Mohamed; Rabinal, M. K.; Mulimani, B. G.

2009-01-01

Here, we propose a simple method for measuring the built-in potential and its temperature dependence of a photodiode by a photosaturation technique. The experimental design facilitates both current-voltage and null voltage measurements as a function of white light intensity. This method gives the built-in potential directly; as a result its…

Strategies in Ebola virus disease (EVD) diagnostics at the point of care

PubMed Central

Coarsey, Chad T.; Esiobu, Nwadiuto; Narayanan, Ramswamy; Pavlovic, Mirjana; Shafiee, Hadi; Asghar, Waseem

2017-01-01

Ebola virus disease (EVD) is a devastating, highly infectious illness with a high mortality rate. The disease is endemic to regions of Central and West Africa, where there is limited laboratory infrastructure and trained staff. The recent 2014 West African EVD outbreak has been unprecedented in case numbers and fatalities, and has proven that such regional outbreaks can become a potential threat to global public health, as it became the source for the subsequent transmission events in Spain and the USA. The urgent need for rapid and affordable means of detecting Ebola is crucial to control the spread of EVD and prevent devastating fatalities. Current diagnostic techniques include molecular diagnostics and other serological and antigen detection assays; which can be time-consuming, laboratory-based, often require trained personnel and specialized equipment. In this review, we discuss the various Ebola detection techniques currently in use, and highlight the potential future directions pertinent to the development and adoption of novel point-of-care diagnostic tools. Finally, a case is made for the need to develop novel microfluidic technologies and versatile rapid detection platforms for early detection of EVD. PMID:28440096

Thoracic organ transplantation: laboratory methods.

PubMed

Patel, Jignesh K; Kobashigawa, Jon A

2013-01-01

Although great progress has been achieved in thoracic organ transplantation through the development of effective immunosuppression, there is still significant risk of rejection during the early post-transplant period, creating a need for routine monitoring for both acute antibody and cellular mediated rejection. The currently available multiplexed, microbead assays utilizing solubilized HLA antigens afford the capability of sensitive detection and identification of HLA and non-HLA specific antibodies. These assays are being used to assess the relative strength of donor specific antibodies; to permit performance of virtual crossmatches which can reduce the waiting time to transplantation; to monitor antibody levels during desensitization; and for heart transplants to monitor antibodies post-transplant. For cell mediated immune responses, the recent development of gene expression profiling has allowed noninvasive monitoring of heart transplant recipients yielding predictive values for acute cellular rejection. T cell immune monitoring in heart and lung transplant recipients has allowed individual tailoring of immunosuppression, particularly to minimize risk of infection. While the current antibody and cellular laboratory techniques have enhanced the ability to manage thoracic organ transplant recipients, future developments from improved understanding of microchimerism and graft tolerance may allow more refined allograft monitoring techniques.

Laboratory techniques for human embryos.

PubMed

Geber, Selmo; Sales, Liana; Sampaio, Marcos A C

2002-01-01

This review is concerned with laboratory techniques needed for assisted conception, particularly the handling of gametes and embryos. Such methods are being increasingly refined. Successive stages of fertilization and embryogenesis require especial care, and often involve the use of micromanipulative methods for intracytoplasmic sperm injection (ICSI) or preimplantation genetic diagnosis. Embryologists must take responsibility for gamete collection and preparation, and for deciding on the means of insemination or ICSI. Embryos must be assessed in culture, during the 1-cell, cleaving and morula/blastocyst stages, and classified according to quality. Co-culture methods may be necessary. The best embryos for transfer must be selected and loaded into the transfer catheter. Embryos not transferred must be cryopreserved, which demands the correct application of current methods of media preparation, seeding and the correct speed for cooling and warming. Before too long, methods of detecting abnormal embryos and avoiding their transfer may become widespread.

Transport equations of electrodiffusion processes in the laboratory reference frame.

PubMed

Garrido, Javier

2006-02-23

The transport equations of electrodiffusion processes use three reference frames for defining the fluxes: Fick's reference in diffusion, solvent-fixed reference in transference numbers, and laboratory fluxes in electric conductivity. The convenience of using only one reference frame is analyzed here from the point of view of the thermodynamics of irreversible processes. A relation between the fluxes of ions and solvent and the electric current density is deduced first from a mass and volume balance. This is then used to show that (i) the laboratory and Fick's diffusion coefficients are identical and (ii) the transference numbers of both the solvent and the ion in the laboratory reference frame are related. Finally, four experimental methods for the measurement of ion transference numbers are analyzed critically. New expressions for evaluating transference numbers for the moving boundary method and the chronopotentiometry technique are deduced. It is concluded that the ion transport equation in the laboratory reference frame plays a key role in the description of electrodiffusion processes.

Adaptive laboratory evolution -- principles and applications for biotechnology.

PubMed

Dragosits, Martin; Mattanovich, Diethard

2013-07-01

Adaptive laboratory evolution is a frequent method in biological studies to gain insights into the basic mechanisms of molecular evolution and adaptive changes that accumulate in microbial populations during long term selection under specified growth conditions. Although regularly performed for more than 25 years, the advent of transcript and cheap next-generation sequencing technologies has resulted in many recent studies, which successfully applied this technique in order to engineer microbial cells for biotechnological applications. Adaptive laboratory evolution has some major benefits as compared with classical genetic engineering but also some inherent limitations. However, recent studies show how some of the limitations may be overcome in order to successfully incorporate adaptive laboratory evolution in microbial cell factory design. Over the last two decades important insights into nutrient and stress metabolism of relevant model species were acquired, whereas some other aspects such as niche-specific differences of non-conventional cell factories are not completely understood. Altogether the current status and its future perspectives highlight the importance and potential of adaptive laboratory evolution as approach in biotechnological engineering.

Clarity: An Open Source Manager for Laboratory Automation

PubMed Central

Delaney, Nigel F.; Echenique, José Rojas; Marx, Christopher J.

2013-01-01

Software to manage automated laboratories interfaces with hardware instruments, gives users a way to specify experimental protocols, and schedules activities to avoid hardware conflicts. In addition to these basics, modern laboratories need software that can run multiple different protocols in parallel and that can be easily extended to interface with a constantly growing diversity of techniques and instruments. We present Clarity: a laboratory automation manager that is hardware agnostic, portable, extensible and open source. Clarity provides critical features including remote monitoring, robust error reporting by phone or email, and full state recovery in the event of a system crash. We discuss the basic organization of Clarity; demonstrate an example of its implementation for the automated analysis of bacterial growth; and describe how the program can be extended to manage new hardware. Clarity is mature; well documented; actively developed; written in C# for the Common Language Infrastructure; and is free and open source software. These advantages set Clarity apart from currently available laboratory automation programs. PMID:23032169

Matrix-assisted laser desorption ionization time-of-flight mass spectrometry, a revolution in clinical microbial identification.

PubMed

Bizzini, A; Greub, G

2010-11-01

Until recently, matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) techniques for the identification of microorganisms remained confined to research laboratories. In the last 2 years, the availability of relatively simple to use MALDI-TOF MS devices, which can be utilized in clinical microbiology laboratories, has changed the laboratory workflows for the identification of pathogens. Recently, the first prospective studies regarding the performance in routine bacterial identification showed that MALDI-TOF MS is a fast, reliable and cost-effective technique that has the potential to replace and/or complement conventional phenotypic identification for most bacterial strains isolated in clinical microbiology laboratories. For routine bacterial isolates, correct identification by MALDI-TOF MS at the species level was obtained in 84.1-93.6% of instances. In one of these studies, a protein extraction step clearly improved the overall valid identification yield, from 70.3% to 93.2%. This review focuses on the current state of use of MALDI-TOF MS for the identification of routine bacterial isolates and on the main difficulties that may lead to erroneous or doubtful identifications. © 2010 The Authors. Clinical Microbiology and Infection © 2010 European Society of Clinical Microbiology and Infectious Diseases.

Measurement of the current and symmetry of the impact liner on the NTLX experiments

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

Stokes, J. L.; Tabaka, L. J.; Parker, J. V.

A series of four liner implosion experiments, denoted the Near Tern Liner Experiments (NTLX) was recently conducted on the Shiva Star capacitor bank at the Air Force Research Laboratory (AFRL). Measurement of the driving currents in these experiments is required for postshot analysis of the liner implosion and experiments conducted in the target cylinder. A Faraday rotation measurement was fielded on Shiva Star to measure the current and compare with the current measured by a Rogowski coil technique. The Faraday rotation technique measured the 16 MA currents in these experiments with better than 1% precision. In addition, six B-dot probesmore » were fielded at equal angles around a circle in the powerflow channel outside the liner to measure the symmetry of the liner impact on the target cylinder. The B-dot probes measure the local Idot, which has a jump when the liner impacts the target cylinder. A high-pass filter allows one to measure this jump more accurately. From the relative timing of the jump signals, the offset of the liner axis and the circularity of liner are inferred.« less

Laboratory Facilities and Measurement Techniques for Beamed-Energy-Propulsion Experiments in Brazil

NASA Astrophysics Data System (ADS)

de Oliveira, Antonio Carlos; Chanes Júnior, José Brosler; Cordeiro Marcos, Thiago Victor; Pinto, David Romanelli; Santos Vilela, Renan Guilherme; Barros Galvão, Victor Alves; Mantovani, Arthur Freire; da Costa, Felipe Jean; dos Santos Assenção, José Adeildo; dos Santos, Alberto Monteiro; de Paula Toro, Paulo Gilberto; Sala Minucci, Marco Antonio; da Silveira Rêgo, Israel; Salvador, Israel Irone; Myrabo, Leik N.

2011-11-01

Laser propulsion is an innovative concept of accessing the space easier and cheaper where the propulsive energy is beamed to the aerospace vehicle in flight from ground—or even satellite-based high-power laser sources. In order to be realistic about laser propulsion, the Institute for Advanced Studies of the Brazilian Air Force in cooperation with the United States Air Force and the Rensselaer Polytechnic Institute are seriously investigating its basic physics mechanisms and engineering aspects at the Henry T. Hamamatsu Laboratory of Hypersonic and Aerothermodynamics in São José dos Campos, Brazil. This paper describes in details the existing facilities and measuring systems such as high-power laser devices, pulsed-hypersonic wind tunnels and high-speed flow visualization system currently utilized in the laboratory for experimentation on laser propulsion.

A survey of current solid state star tracker technology

NASA Astrophysics Data System (ADS)

Armstrong, R. W.; Staley, D. A.

1985-12-01

This paper is a survey of the current state of the art in design of star trackers for spacecraft attitude determination systems. Specific areas discussed are sensor technology, including the current state-of-the-art solid state sensors and techniques of mounting and cooling the sensor, analog image preprocessing electronics performance, and digital processing hardware and software. Three examples of area array solid state star tracker development are presented - ASTROS, developed by the Jet Propulsion Laboratory, the Retroreflector Field Tracker (RFT) by Ball Aerospace, and TRW's MADAN. Finally, a discussion of solid state line arrays explores the possibilities for one-dimensional imagers which offer simplified scan control electronics.

[Molecular techniques in mycology].

PubMed

Rodríguez-Tudela, Juan Luis; Cuesta, Isabel; Gómez-López, Alicia; Alastruey-Izquierdo, Ana; Bernal-Martínez, Leticia; Cuenca-Estrella, Manuel

2008-11-01

An increasing number of molecular techniques for the diagnosis of fungal infections have been developed in the last few years, due to the growing prevalence of mycoses and the length of time required for diagnosis when classical microbiological methods are used. These methods are designed to resolve the following aspects of mycological diagnosis: a) Identification of fungi to species level by means of sequencing relevant taxonomic targets; b) early clinical diagnosis of invasive fungal infections; c) detection of molecular mechanisms of resistance to antifungal agents; and d) molecular typing of fungi. Currently, these methods are restricted to highly developed laboratories. However, some of these techniques will probably be available in daily clinical practice in the near future.

Filling box stratification fed by a gravity current

NASA Astrophysics Data System (ADS)

Hogg, Charlie; Huppert, Herbert; Imberger, Jorg

2012-11-01

Fluids in confined basins can be stratified by the filling box mechanism. The source of dense fluid in geophysical applications, such as a cold river entering a warmer lake, can be a gravity current running over a shallow slope. Filling box models are often, however, based on the dynamics of vertically falling, unconfined, plumes which entrain fluid by a different mechanism to gravity currents on shallow slopes. Laboratory tank experiments of a filling box fed by a gravity current running over a shallow slope were carried out using a dye attenuation technique to investigate the development of the stratification of the ambient. These results demonstrate the differences in the stratification generated by a gravity current compared to that generated by a plume and demonstrate the nature of entrainment into gravity currents on shallow slopes.

Newly Developed Techniques on Polycondensation, Ring-Opening Polymerization and Polymer Modification: Focus on Poly(Lactic Acid)

PubMed Central

Hu, Yunzi; Daoud, Walid A.; Cheuk, Kevin Ka Leung; Lin, Carol Sze Ki

2016-01-01

Polycondensation and ring-opening polymerization are two important polymer synthesis methods. Poly(lactic acid), the most typical biodegradable polymer, has been researched extensively from 1900s. It is of significant importance to have an up-to-date review on the recent improvement in techniques for biodegradable polymers. This review takes poly(lactic acid) as the example to present newly developed polymer synthesis techniques on polycondensation and ring-opening polymerization reported in the recent decade (2005–2015) on the basis of industrial technique modifications and advanced laboratory research. Different polymerization methods, including various solvents, heating programs, reaction apparatus and catalyst systems, are summarized and compared with the current industrial production situation. Newly developed modification techniques for polymer properties improvement are also discussed based on the case of poly(lactic acid). PMID:28773260

UNCERTAINTY ON RADIATION DOSES ESTIMATED BY BIOLOGICAL AND RETROSPECTIVE PHYSICAL METHODS.

PubMed

Ainsbury, Elizabeth A; Samaga, Daniel; Della Monaca, Sara; Marrale, Maurizio; Bassinet, Celine; Burbidge, Christopher I; Correcher, Virgilio; Discher, Michael; Eakins, Jon; Fattibene, Paola; Güçlü, Inci; Higueras, Manuel; Lund, Eva; Maltar-Strmecki, Nadica; McKeever, Stephen; Rääf, Christopher L; Sholom, Sergey; Veronese, Ivan; Wieser, Albrecht; Woda, Clemens; Trompier, Francois

2018-03-01

Biological and physical retrospective dosimetry are recognised as key techniques to provide individual estimates of dose following unplanned exposures to ionising radiation. Whilst there has been a relatively large amount of recent development in the biological and physical procedures, development of statistical analysis techniques has failed to keep pace. The aim of this paper is to review the current state of the art in uncertainty analysis techniques across the 'EURADOS Working Group 10-Retrospective dosimetry' members, to give concrete examples of implementation of the techniques recommended in the international standards, and to further promote the use of Monte Carlo techniques to support characterisation of uncertainties. It is concluded that sufficient techniques are available and in use by most laboratories for acute, whole body exposures to highly penetrating radiation, but further work will be required to ensure that statistical analysis is always wholly sufficient for the more complex exposure scenarios.

Diagnostic approach to hemoglobins with high oxygen affinity: experience from France and Belgium and review of the literature.

PubMed

Orvain, Corentin; Joly, Philippe; Pissard, Serge; Badiou, Stéphanie; Badens, Catherine; Bonello-Palot, Nathalie; Couque, Nathalie; Gulbis, Béatrice; Aguilar-Martinez, Patricia

2017-02-01

Congenital causes of erythrocytosis are now more easily identified due to the improvement of the molecular characterization of many of them. Among these causes, hemoglobins with high oxygen affinity take a large place. The aim of this work was to reevaluate the diagnostic approach of these disorders. To assess the current practices, we sent a questionnaire to the expert laboratories in the diagnosis of hemoglobinopathies in France and Belgium. In parallel, we gathered the methods used for the diagnosis of the hemoglobins with high oxygen affinity indexed in the international database HbVar. Even though they remain a rare cause of erythrocytosis (1 to 5 positive diagnosis every year in each of the questioned specialized laboratories), hemoglobins with high oxygen affinity are increasingly suspected by clinicians. Phenotypic assessment by laboratory techniques remains a main step in their diagnosis as it enables the finding of 93% of them in the questioned laboratories (28 of the 30 variants diagnosed during the last 5 years). Among the 96 hemoglobin variants with high oxygen affinity indexed in the international database, 87% could be diagnosed with phenotypic techniques. A direct measure of the p50 with the Hemox-Analyzer is included in the diagnostic approach of half of the laboratories only, because of the poor availability of this apparatus. Comparatively, the estimation of p50 by blood gas analyzers on venous blood is a much more convenient and attractive method but due to the lack of proof as to its effectiveness in the diagnosis of hemoglobins with high oxygen affinity, it requires further investigations. Beta- and alphaglobin genes analysis by molecular biology techniques is essential as it either allows a quick and definite identification of the variant or definitely excludes the diagnosis. It is thus systematically performed as a first or second step method, according to the laboratory practice.

Clinical Relevance of Coronary Fractional Flow Reserve: Art-of-state.

PubMed

Adiputra, Yohanes; Chen, Shao-Liang

2015-05-20

The objective was to delineate the current knowledge of fractional flow reserve (FFR) in terms of definition, features, clinical applications, and pitfalls of measurement of FFR. We searched database for primary studies published in English. The database of National Library of Medicine (NLM), MEDLINE, and PubMed up to July 2014 was used to conduct a search using the keyword term "FFR". The articles about the definition, features, clinical application, and pitfalls of measurement of FFR were identified, retrieved, and reviewed. Coronary pressure-derived FFR rapidly assesses the hemodynamic significance of individual coronary artery lesions and can readily be performed in the catheterization laboratory. The use of FFR has been shown to effectively guide coronary revascularization procedures leading to improved patient outcomes. FFR is a valuable tool to determine the functional significance of coronary stenosis. It combines physiological and anatomical information, and can be followed immediately by percutaneous coronary intervention (PCI) if necessary. The technique of FFR measurement can be performed easily, rapidly, and safely in the catheterization laboratory. By systematic use of FFR in dubious stenosis and multi-vessel disease, PCI can be made an even more effective and better treatment than it is currently. The current clinical evidence for FFR should encourage cardiologists to use this tool in the catheterization laboratory.

Using First-Person Perspective Filming Techniques for a Chemistry Laboratory Demonstration to Facilitate a Flipped Pre-Lab

ERIC Educational Resources Information Center

Fung, Fun Man

2015-01-01

The current model of flipped classroom ensures that learning is not being restricted to the brick and mortar setting. Lessons can be conducted anywhere, anytime, as long as there is a good internet connection. Most of the flipped classroom and e-lectures are videos recording PowerPoint slides with a human voice as the audio instruction. In…

Pulsed Energy Systems for Generating Plasmas

NASA Technical Reports Server (NTRS)

Rose, M. Franklin; Shotts, Z.

2005-01-01

This paper will describe the techniques needed to electrically generate highly ionized dense plasmas for a variety of applications. The components needed in pulsed circuits are described in terms of general performance parameters currently available from commercial vendors. Examples of pulsed systems using these components are described and technical data from laboratory experiments presented. Experimental data are given for point designs, capable of multi-megawatt power levels.

Data assimilation of ground GPG total electron content into a physics-based ionosheric model by use of the Kalman filter

NASA Technical Reports Server (NTRS)

Hajj, G. A.; Wilson, B. D.; Wang, C.; Pi, X.; Rosen, I. G.

2004-01-01

A three-dimensional (3-D) Global Assimilative Ionospheric Model (GAIM) is currently being developed by a joint University of Southern California and Jet Propulsion Laboratory (JPL) team. To estimate the electron density on a global grid, GAIM uses a first-principles ionospheric physics model and the Kalman filter as one of its possible estimation techniques.

Bisphosphonates in the Prevention of Post-Traumatic Osteoarthritis

DTIC Science & Technology

2014-07-01

OARSI-describe PTOA scoring system was brought into the lab and 4 individuals have been trained on it. Currently, the safranin-O stained samples are...of chondrocyte proliferation (Ki-67), apoptosis (activated caspase-3), hypertrophy (collagen type X), anabolism, catabolism, and inflammation within...surgery training and technique import into P-PI laboratory complete. o Baseline, DMM-only, and age-matched cohort groups completed for D0 through

Planetary atmospheric physics and solar physics research

NASA Technical Reports Server (NTRS)

1973-01-01

An overview is presented on current and planned research activities in the major areas of solar physics, planetary atmospheres, and space astronomy. The approach to these unsolved problems involves experimental techniques, theoretical analysis, and the use of computers to analyze the data from space experiments. The point is made that the research program is characterized by each activity interacting with the other activities in the laboratory.

Mars Oxidant and Radical Detector

NASA Technical Reports Server (NTRS)

Yen, A. S.; Kim, S. S.

2003-01-01

The Mars Oxidant and Radical Detector is an instrument designed to characterize the reactive nature of the martian surface environment. Using Electron Paramagnetic Resonance (EPR) techniques, this instrument can detect, identify, and quantify radical species in soil samples, including those inferred to be present by the Viking experiments. This instrument is currently funded by the Mars Instrument Development Program and is compatible with the Mars Science Laboratory mission.

An Advanced Analytical Chemistry Experiment Using Gas Chromatography-Mass Spectrometry, MATLAB, and Chemometrics to Predict Biodiesel Blend Percent Composition

ERIC Educational Resources Information Center

Pierce, Karisa M.; Schale, Stephen P.; Le, Trang M.; Larson, Joel C.

2011-01-01

We present a laboratory experiment for an advanced analytical chemistry course where we first focus on the chemometric technique partial least-squares (PLS) analysis applied to one-dimensional (1D) total-ion-current gas chromatography-mass spectrometry (GC-TIC) separations of biodiesel blends. Then, we focus on n-way PLS (n-PLS) applied to…

Field Demonstrations of Active Laser Ranging with Sub-mm Precision

NASA Technical Reports Server (NTRS)

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

2011-01-01

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

Hyphenated analytical techniques for materials characterisation

NASA Astrophysics Data System (ADS)

Armstrong, Gordon; Kailas, Lekshmi

2017-09-01

This topical review will provide a survey of the current state of the art in ‘hyphenated’ techniques for characterisation of bulk materials, surface, and interfaces, whereby two or more analytical methods investigating different properties are applied simultaneously to the same sample to better characterise the sample than can be achieved by conducting separate analyses in series using different instruments. It is intended for final year undergraduates and recent graduates, who may have some background knowledge of standard analytical techniques, but are not familiar with ‘hyphenated’ techniques or hybrid instrumentation. The review will begin by defining ‘complementary’, ‘hybrid’ and ‘hyphenated’ techniques, as there is not a broad consensus among analytical scientists as to what each term means. The motivating factors driving increased development of hyphenated analytical methods will also be discussed. This introduction will conclude with a brief discussion of gas chromatography-mass spectroscopy and energy dispersive x-ray analysis in electron microscopy as two examples, in the context that combining complementary techniques for chemical analysis were among the earliest examples of hyphenated characterisation methods. The emphasis of the main review will be on techniques which are sufficiently well-established that the instrumentation is commercially available, to examine physical properties including physical, mechanical, electrical and thermal, in addition to variations in composition, rather than methods solely to identify and quantify chemical species. Therefore, the proposed topical review will address three broad categories of techniques that the reader may expect to encounter in a well-equipped materials characterisation laboratory: microscopy based techniques, scanning probe-based techniques, and thermal analysis based techniques. Examples drawn from recent literature, and a concluding case study, will be used to explain the practical issues that arise in combining different techniques. We will consider how the complementary and varied information obtained by combining these techniques may be interpreted together to better understand the sample in greater detail than that was possible before, and also how combining different techniques can simplify sample preparation and ensure reliable comparisons are made between multiple analyses on the same samples—a topic of particular importance as nanoscale technologies become more prevalent in applied and industrial research and development (R&D). The review will conclude with a brief outline of the emerging state of the art in the research laboratory, and a suggested approach to using hyphenated techniques, whether in the teaching, quality control or R&D laboratory.

Current status of hybrid coronary revascularization.

PubMed

Jaik, Nikhil P; Umakanthan, Ramanan; Leacche, Marzia; Solenkova, Natalia; Balaguer, Jorge M; Hoff, Steven J; Ball, Stephen K; Zhao, David X; Byrne, John G

2011-10-01

Hybrid coronary revascularization combines coronary artery bypass surgery with percutaneous coronary intervention techniques to treat coronary artery disease. The potential benefits of such a technique are to offer the patients the best available treatments for coronary artery disease while minimizing the risks of the surgery. Hybrid coronary revascularization has resulted in the establishment of new 'hybrid operating suites', which incorporate and integrate the capabilities of a cardiac surgery operating room with that of an interventional cardiology laboratory. Hybrid coronary revascularization has greatly augmented teamwork and cooperation between both fields and has demonstrated encouraging as well as good initial outcomes.

Towards standardized testing methodologies for optical properties of components in concentrating solar thermal power plants

NASA Astrophysics Data System (ADS)

Sallaberry, Fabienne; Fernández-García, Aránzazu; Lüpfert, Eckhard; Morales, Angel; Vicente, Gema San; Sutter, Florian

2017-06-01

Precise knowledge of the optical properties of the components used in the solar field of concentrating solar thermal power plants is primordial to ensure their optimum power production. Those properties are measured and evaluated by different techniques and equipment, in laboratory conditions and/or in the field. Standards for such measurements and international consensus for the appropriate techniques are in preparation. The reference materials used as a standard for the calibration of the equipment are under discussion. This paper summarizes current testing methodologies and guidelines for the characterization of optical properties of solar mirrors and absorbers.

Verifying the Performance of RTDs in Nuclear Power Plants

NASA Astrophysics Data System (ADS)

Hashemian, H. M.

2003-09-01

This paper describes a number of techniques that have been developed for nuclear power plants to ensure that optimum steady-state and transient performance is achieved with the resistance temperature detectors (RTDs) that are used in the plant for critical temperature measurements. This includes precision laboratory calibration of RTDs, the Loop Current Step Response (LCSR) method for in-situ response time measurements, a cross calibration technique to verify the steady-state performance of RTDs as installed in the plant, and the Time Domain Reflectometry (TDR) test that is used to identify the location of a problem along RTD cables.

Comparison of edge analysis techniques for the determination of the MTF of digital radiographic systems.

PubMed

Samei, Ehsan; Buhr, Egbert; Granfors, Paul; Vandenbroucke, Dirk; Wang, Xiaohui

2005-08-07

The modulation transfer function (MTF) is well established as a metric to characterize the resolution performance of a digital radiographic system. Implemented by various laboratories, the edge technique is currently the most widespread approach to measure the MTF. However, there can be differences in the results attributed to differences in the analysis technique employed. The objective of this study was to determine whether comparable results can be obtained from different algorithms processing identical images representative of those of current digital radiographic systems. Five laboratories participated in a round-robin evaluation of six different algorithms including one prescribed in the International Electrotechnical Commission (IEC) 62220-1 standard. The algorithms were applied to two synthetic and 12 real edge images from different digital radiographic systems including CR, and direct- and indirect-conversion detector systems. The results were analysed in terms of variability as well as accuracy of the resulting presampled MTFs. The results indicated that differences between the individual MTFs and the mean MTF were largely below 0.02. In the case of the two simulated edge images, all algorithms yielded similar results within 0.01 of the expected true MTF. The findings indicated that all algorithms tested in this round-robin evaluation, including the IEC-prescribed algorithm, were suitable for accurate MTF determination from edge images, provided the images are not excessively noisy. The agreement of the MTF results was judged sufficient for the measurement of the MTF necessary for the determination of the DQE.

Submillimeter Measurements of Photolysis Products in Interstellar Ice Analogs: A New Experimental Technique

NASA Technical Reports Server (NTRS)

Milam, Stefanie N.; Weaver, Susanna Widicus

2012-01-01

Over 150 molecular species have been confirmed in space, primarily by their rotational spectra at millimeter/submillimeter wavelengths, which yield an unambiguous identification. Many of the known interstellar organic molecules cannot be explained by gas-phase chemistry. It is now presumed that they are produced by surface reactions of the simple ices and/or grains observed and released into the gas phase by sublimation, sputtering, etc. Additionally, the chemical complexity found in meteorites and samples returned from comets far surpasses that of the remote detections for the interstellar medium (ISM), comets, and planetary atmospheres. Laboratory simulations of interstellar/cometary ices have found, from the analysis of the remnant residue of the warmed laboratory sample, that such molecules are readily formed; however, it has yet to be determined if they are formed during the warm phase or within the ice during processing. Most analysis of the ice during processing reveals molecular changes, though the exact quantities and species formed are highly uncertain with current techniques due to overwhelming features of simple ices. Remote sensing with high resolution spectroscopy is currently the only method to detect trace species in the ISM and the primary method for comets and icy bodies in the Solar System due to limitations of sample return. We have recently designed an experiment to simulate interstellar/cometary/planetary ices and detect trace species employing the same techniques used for remote observations. Preliminary results will be presented.

Neuroimaging techniques for memory detection: scientific, ethical, and legal issues.

PubMed

Meegan, Daniel V

2008-01-01

There is considerable interest in the use of neuroimaging techniques for forensic purposes. Memory detection techniques, including the well-publicized Brain Fingerprinting technique (Brain Fingerprinting Laboratories, Inc., Seattle WA), exploit the fact that the brain responds differently to sensory stimuli to which it has been exposed before. When a stimulus is specifically associated with a crime, the resulting brain activity should differentiate between someone who was present at the crime and someone who was not. This article reviews the scientific literature on three such techniques: priming, old/new, and P300 effects. The forensic potential of these techniques is evaluated based on four criteria: specificity, automaticity, encoding flexibility, and longevity. This article concludes that none of the techniques are devoid of forensic potential, although much research is yet to be done. Ethical issues, including rights to privacy and against self-incrimination, are discussed. A discussion of legal issues concludes that current memory detection techniques do not yet meet United States standards of legal admissibility.

CERTS Microgrid Laboratory Test Bed - PIER Final Project Report

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

Eto, Joseph H.; Eto, Joseph H.; Lasseter, Robert

2008-07-25

The objective of the CERTS Microgrid Laboratory Test Bed project was to enhance the ease of integrating small energy sources into a microgrid. The project accomplished this objective by developing and demonstrating three advanced techniques, collectively referred to as the CERTS Microgrid concept, that significantly reduce the level of custom field engineering needed to operate microgrids consisting of small generating sources. The techniques comprising the CERTS Microgrid concept are: 1) a method for effecting automatic and seamless transitions between grid-connected and islanded modes of operation; 2) an approach to electrical protection within the microgrid that does not depend on highmore » fault currents; and 3) a method for microgrid control that achieves voltage and frequency stability under islanded conditions without requiring high-speed communications. The techniques were demonstrated at a full-scale test bed built near Columbus, Ohio and operated by American Electric Power. The testing fully confirmed earlier research that had been conducted initially through analytical simulations, then through laboratory emulations, and finally through factory acceptance testing of individual microgrid components. The islanding and resychronization method met all Institute of Electrical and Electronics Engineers 1547 and power quality requirements. The electrical protections system was able to distinguish between normal and faulted operation. The controls were found to be robust and under all conditions, including difficult motor starts. The results from these test are expected to lead to additional testing of enhancements to the basic techniques at the test bed to improve the business case for microgrid technologies, as well to field demonstrations involving microgrids that involve one or mroe of the CERTS Microgrid concepts.« less

Computational analysis of fluid dynamics in pharmaceutical freeze-drying.

PubMed

Alexeenko, Alina A; Ganguly, Arnab; Nail, Steven L

2009-09-01

Analysis of water vapor flows encountered in pharmaceutical freeze-drying systems, laboratory-scale and industrial, is presented based on the computational fluid dynamics (CFD) techniques. The flows under continuum gas conditions are analyzed using the solution of the Navier-Stokes equations whereas the rarefied flow solutions are obtained by the direct simulation Monte Carlo (DSMC) method for the Boltzmann equation. Examples of application of CFD techniques to laboratory-scale and industrial scale freeze-drying processes are discussed with an emphasis on the utility of CFD for improvement of design and experimental characterization of pharmaceutical freeze-drying hardware and processes. The current article presents a two-dimensional simulation of a laboratory scale dryer with an emphasis on the importance of drying conditions and hardware design on process control and a three-dimensional simulation of an industrial dryer containing a comparison of the obtained results with analytical viscous flow solutions. It was found that the presence of clean in place (CIP)/sterilize in place (SIP) piping in the duct lead to significant changes in the flow field characteristics. The simulation results for vapor flow rates in an industrial freeze-dryer have been compared to tunable diode laser absorption spectroscopy (TDLAS) and gravimetric measurements.

Dissolution of Material and Test reactor Fuel in an H-Canyon Dissolver

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

Daniel, W. E.; Rudisill, T. S.; O'Rourke, P. E.

2017-01-26

In an amended record of decision for the management of spent nuclear fuel (SNF) at the Savannah River Site, the US Department of Energy has authorized the dissolution and recovery of U from 1000 bundles of Al-clad SNF. The SNF is fuel from domestic and foreign research reactors and is typically referred to as Material Test Reactor (MTR) fuel. Bundles of MTR fuel containing assemblies fabricated from U-Al alloys (or other U compounds) are currently dissolved using a Hg-catalyzed HNO3 flowsheet. Since the development of the existing flowsheet, improved experimental methods have been developed to more accurately characterize the offgasmore » composition and generation rate during laboratory dissolutions. Recently, these new techniques were successfully used to develop a flowsheet for the dissolution of High Flux Isotope Reactor (HFIR) fuel. Using the data from the HFIR dissolution flowsheet development and necessary laboratory experiments, the Savannah River National Laboratory (SRNL) was requested to define flowsheet conditions for the dissolution of MTR fuels. With improved offgas characterization techniques, SRNL will be able define the number of bundles of fuel which can be charged to an H-Canyon dissolver with much less conservatism.« less

Parametric Study of HTS Coil Quench Protection Strategies

NASA Astrophysics Data System (ADS)

Seibert, Joseph; Zarnstorff, Michael; Zhai, Yuhu

2016-10-01

Next generation fusion devices require high magnetic fields to adequately contain burning plasmas. Use of high temperature superconducting (HTS) coils to generate these magnetic fields would lower energy cost of operation as well as increase stability of the superconducting state compared to low temperature superconducting coils. However, use of HTS coils requires developing quench protection strategies to prevent damage to the coils. One technique involves the utilization of copper discs and other conductors mutually coupled to the HTS coil to quickly extract the current from the coil. Another technique allows conduction between HTS turns to reduce the current in the coil during quench. This project describes a parametric study of the HTS coil and resistive-conductor setup in order to determine limiting cases of the geometry in an attempt to optimize current extraction and coil protection during quench scenarios. This work was supported in part by the U.S. Department of Energy, Office of Science, Office of Workforce Development for Teachers and Scientists (WDTS) under the Science Undergraduate Laboratory Internship (SULI) program.

NDE of the space shuttle orbiter thermal protection system: Phase 2 final report

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

Tow, D.M.; Barna, B.A.; Rodriguez, J.G.

1989-03-01

Research continued on the development of a nondestructive evaluation technique for inspecting bonds on the space shuttle orbiter thermal protection system tiles. The approach taken uses a noncontacting laser sensor to measure the vibrational response of bonded tiles to acoustical excitation. Laboratory work concentrated on investigating the dynamic response of ''acreage'' tiles, i.e., tiles covering the underside of the orbiter, all approximately square. A number of promising unbond signatures have been identified in the time and frequency domain response. Field tests were conducted to study environmental effects on the techniques being developed. The ambient motion of the orbiter was foundmore » to be larger than expected, necessitating modifications to current techniques. 2 refs., 21 figs., 1 tab.« less

A procedure for automated land use mapping using remotely sensed multispectral scanner data

NASA Technical Reports Server (NTRS)

Whitley, S. L.

1975-01-01

A system of processing remotely sensed multispectral scanner data by computer programs to produce color-coded land use maps for large areas is described. The procedure is explained, the software and the hardware are described, and an analogous example of the procedure is presented. Detailed descriptions of the multispectral scanners currently in use are provided together with a summary of the background of current land use mapping techniques. The data analysis system used in the procedure and the pattern recognition software used are functionally described. Current efforts by the NASA Earth Resources Laboratory to evaluate operationally a less complex and less costly system are discussed in a separate section.

U.S. and South Korean Cooperation in the World Nuclear Energy Market: Major Policy Considerations

DTIC Science & Technology

2010-01-21

a laboratory-scale research program on reprocessing spent fuel with an advanced pyroprocessing technique. However, the level of consensus over the... pyroprocessing option among government agencies, Korean electric utilities, and the public remains uncertain. The current U.S.-Korea 123 agreement...permission. KAERI’s pyroprocessing technology would partially separate plutonium and uranium from spent fuel, but the United States has not allowed the

Training Manpower Development Work Supervisors in the Use of Behavior Modification Techniques to Teach Job-Required Skills. Special Report.

ERIC Educational Resources Information Center

Neiswender, Lenore

The paper describes a current research project now being conducted by the Experimental Manpower Laboratory at Mobilization for Youth (MFY-EML) in New York City. The overall objective of the MFY-EML is to develop and test new methods of teaching vocational skills to hard-to-employ youth. The MFY-EML is involved in developing a program to teach…

Lessons learned with molecular methods targeting the BCSP-31 membrane protein for diagnosis of human brucellosis.

PubMed

Sanjuan-Jimenez, Rocio; Colmenero, Juan D; Morata, Pilar

2017-06-01

Brucellosis remains an emerging and re-emerging zoonosis worldwide causing high human morbidity. It usually affects persons who are permanently exposed to fastidious microorganisms of the Brucella genus and has a nonspecific clinical picture. Thus, diagnosis of brucellosis can sometimes be difficult. Molecular techniques have recently been found very useful in the diagnosis of brucellosis together with its common and very diverse focal complications. We herein review all the lessons learned by our group concerning the molecular diagnosis of human brucellosis over the last twenty years. The results, initially using one-step conventional PCR, later PCR-ELISA and more recently real-time PCR, using both fluorescent intercalating reagents (SYBR-Green I) and specific probes (Taqman), have shown that these techniques are all much more sensitive than bacteriological methods and more specific than the usual serological techniques for the diagnosis of primary infection, the post-treatment control of the disease, early detection of relapse and the diagnosis of focal complications. Optimization of the technique and improvements introduced over the years show that molecular methods, currently accessible for most clinical laboratories, enable easy rapid diagnosis of brucellosis at the same time as they avoid any risk to laboratory personnel while handling live Brucella spp. Copyright © 2017 Elsevier B.V. All rights reserved.

New Tools & Techniques for the Metallomics Revolution

NASA Astrophysics Data System (ADS)

Koppenaal, D. W.; Hieftje, G. M.

2004-12-01

The metallome has been defined as the complete complement of metals and metal moieties in a biological cell, tissue, or system. This definition is akin to that of the genome (genes), proteome (proteins), and metabolome (metabolites). Metallomics accordingly is the study of metals and metal species, and their interactions, transformations, and functions in biological systems. While traditional bioinorganic chemistry has focused on the role and interactions of a single (or few) metals in a protein or enzyme system, metallomics purports to study global, multi-element interactions and relationships. The metallomics challenges for analytical chemistry and biochemical characterization are significant. This paper will discuss these challenges and the emergent techniques and tools that are being developed to address them. Mass spectrometry will play an important and pivotal role. Two approaches are currently being developed in the authors' laboratories. At Pacific Northwest National Laboratory, an extremely high-resolution approach using Fourier Transform Ion Cyclotron Resonance mass spectrometry (FT-ICRMS) is under development. At Indiana University, a rapid, dual-reflectron Time-of-Flight mass spectrometry (TOFMS) technique is being developed. Both approaches rely on dual inductively coupled plasma (ICP) and electrospray ionization (ESI) sources for elemental and biomolecular ion generation. The initial development of these techniques, and their potential application to systems biology and environmental characterization, will be discussed.

Multispectral fluorescence imaging techniques for nondestructive food safety inspection

NASA Astrophysics Data System (ADS)

Kim, Moon S.; Lefcourt, Alan M.; Chen, Yud-Ren

2004-03-01

The use of spectral sensing has gained acceptance as a rapid means for nondestructive inspection of postharvest food produce. Current technologies generally use color or a single wavelength camera technology. The applicability and sensitivity of these techniques can be expanded through the use of multiple wavelengths. Reflectance in the Vis/NIR is the prevalent spectral technique. Fluorescence, compared to reflectance, is regarded as a more sensitive technique due to its dynamic responses to subtle changes in biological entities. Our laboratory has been exploring fluorescence as a potential means for detection of quality and wholesomeness of food products. Applications of fluorescence sensing require an understanding of the spectral characteristics emanating from constituents and potential contaminants. A number of factors affecting fluorescence emission characteristics are discussed. Because of relatively low fluorescence quantum yield from biological samples, a system with a powerful pulse light source such as a laser coupled with a gated detection device is used to harvest fluorescence, in the presence of ambient light. Several fluorescence sensor platforms developed in our laboratory, including hyperspectral imaging, and laser-induced fluorescence (LIF) and steady-state fluorescence imaging systems with multispectral capabilities are presented. We demonstrate the potential uses of recently developed fluorescence imaging platforms in food safety inspection of apples contaminated with animal feces.

Clinical application of high throughput molecular screening techniques for pharmacogenomics

PubMed Central

Wiita, Arun P; Schrijver, Iris

2011-01-01

Genetic analysis is one of the fastest-growing areas of clinical diagnostics. Fortunately, as our knowledge of clinically relevant genetic variants rapidly expands, so does our ability to detect these variants in patient samples. Increasing demand for genetic information may necessitate the use of high throughput diagnostic methods as part of clinically validated testing. Here we provide a general overview of our current and near-future abilities to perform large-scale genetic testing in the clinical laboratory. First we review in detail molecular methods used for high throughput mutation detection, including techniques able to monitor thousands of genetic variants for a single patient or to genotype a single genetic variant for thousands of patients simultaneously. These methods are analyzed in the context of pharmacogenomic testing in the clinical laboratories, with a focus on tests that are currently validated as well as those that hold strong promise for widespread clinical application in the near future. We further discuss the unique economic and clinical challenges posed by pharmacogenomic markers. Our ability to detect genetic variants frequently outstrips our ability to accurately interpret them in a clinical context, carrying implications both for test development and introduction into patient management algorithms. These complexities must be taken into account prior to the introduction of any pharmacogenomic biomarker into routine clinical testing. PMID:23226057

Cystic Fibrosis: Microbiology and Host Response.

PubMed

Zemanick, Edith T; Hoffman, Lucas R

2016-08-01

The earliest descriptions of lung disease in people with cystic fibrosis (CF) showed the involvement of 3 interacting pathophysiologic elements in CF airways: mucus obstruction, inflammation, and infection. Over the past 7 decades, our understanding of CF respiratory microbiology and inflammation has evolved with the introduction of new treatments, increased longevity, and increasingly sophisticated laboratory techniques. This article reviews the current understanding of infection and inflammation and their roles in CF lung disease. It also discusses how this constantly evolving information is used to inform current therapeutic strategies, measures and predictors of disease severity, and research priorities. Copyright © 2016 Elsevier Inc. All rights reserved.

Instrumentation for motor-current signature analysis using synchronous sampling

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

Castleberry, K.N.

1996-07-01

Personnel in the Instrumentation and Controls Division at Oak Ridge National Laboratory, in association with the United States Enrichment Corporation, the U.S. Navy, and various Department of Energy sponsors, have been involved in the development and application of motor-current signature analysis for several years. In that time, innovation in the field has resulted in major improvements in signal processing, analysis, and system performance and capabilities. Recent work has concentrated on industrial implementation of one of the most promising new techniques. This report describes the developed method and the instrumentation package that is being used to investigate and develop potential applications.

Euthanasia using gaseous agents in laboratory rodents.

PubMed

Valentim, A M; Guedes, S R; Pereira, A M; Antunes, L M

2016-08-01

Several questions have been raised in recent years about the euthanasia of laboratory rodents. Euthanasia using inhaled agents is considered to be a suitable aesthetic method for use with a large number of animals simultaneously. Nevertheless, its aversive potential has been criticized in terms of animal welfare. The data available regarding the use of carbon dioxide (CO2), inhaled anaesthetics (such as isoflurane, sevoflurane, halothane and enflurane), as well as carbon monoxide and inert gases are discussed throughout this review. Euthanasia of fetuses and neonates is also addressed. A table listing currently available information to ease access to data regarding euthanasia techniques using gaseous agents in laboratory rodents was compiled. Regarding better animal welfare, there is currently insufficient evidence to advocate banning or replacing CO2 in the euthanasia of rodents; however, there are hints that alternative gases are more humane. The exposure to a volatile anaesthetic gas before loss of consciousness has been proposed by some scientific studies to minimize distress; however, the impact of such a measure is not clear. Areas of inconsistency within the euthanasia literature have been highlighted recently and stem from insufficient knowledge, especially regarding the advantages of the administration of isoflurane or sevoflurane over CO2, or other methods, before loss of consciousness. Alternative methods to minimize distress may include the development of techniques aimed at inducing death in the home cage of animals. Scientific outcomes have to be considered before choosing the most suitable euthanasia method to obtain the best results and accomplish the 3Rs (replacement, reduction and refinement). © The Author(s) 2015.

A rapid Orthopoxvirus purification protocol suitable for high-containment laboratories.

PubMed

Hughes, Laura; Wilkins, Kimberly; Goldsmith, Cynthia S; Smith, Scott; Hudson, Paul; Patel, Nishi; Karem, Kevin; Damon, Inger; Li, Yu; Olson, Victoria A; Satheshkumar, P S

2017-05-01

Virus purification in a high-containment setting provides unique challenges due to barrier precautions and operational safety approaches that are not necessary in lower biosafety level (BSL) 2 environments. The need for high risk group pathogen diagnostic assay development, anti-viral research, pathogenesis and vaccine efficacy research necessitates work in BSL-3 and BSL-4 labs with infectious agents. When this work is performed in accordance with BSL-4 practices, modifications are often required in standard protocols. Classical virus purification techniques are difficult to execute in a BSL-3 or BSL-4 laboratory because of the work practices used in these environments. Orthopoxviruses are a family of viruses that, in some cases, requires work in a high-containment laboratory and due to size do not lend themselves to simpler purification methods. Current CDC purification techniques of orthopoxviruses uses 1,1,2-trichlorotrifluoroethane, commonly known as Genetron ® . Genetron ® is a chlorofluorocarbon (CFC) that has been shown to be detrimental to the ozone and has been phased out and the limited amount of product makes it no longer a feasible option for poxvirus purification purposes. Here we demonstrate a new Orthopoxvirus purification method that is suitable for high-containment laboratories and produces virus that is not only comparable to previous purification methods, but improves on purity and yield. Published by Elsevier B.V.

Fat-Soluble Vitamins: Clinical Indications and Current Challenges for Chromatographic Measurement

PubMed Central

Albahrani, Ali A.; Greaves, Ronda F.

2016-01-01

Fat-soluble vitamins, including vitamins A, D and E, are required for a wide variety of physiological functions. Over the past two decades, deficiencies of these vitamins have been associated with increased risk of cancer, type II diabetes mellitus and a number of immune system disorders. In addition, there is increasing evidence of interactions between these vitamins, especially between vitamins A and D. As a result of this enhanced clinical association with disease, translational clinical research and laboratory requests for vitamin measurements have significantly increased. These laboratory requests include measurement of 25-OHD (vitamin D), retinol (vitamin A) and α-tocopherol (vitamin E); the most accepted blood indicators for the assessment of body fat-soluble vitamin (FSV) status. There are significant obstacles to precise FSV measurement in blood. These obstacles include their physical and chemical properties, incomplete standardisation of measurement and limitations in the techniques that are currently used for quantification. The aim of this review is to briefly outline the metabolism and interactions of FSV as a prelude to identifying the current challenges for the quantification of blood vitamins A, D and E. PMID:27057076

Fat-Soluble Vitamins: Clinical Indications and Current Challenges for Chromatographic Measurement.

PubMed

Albahrani, Ali A; Greaves, Ronda F

2016-02-01

Fat-soluble vitamins, including vitamins A, D and E, are required for a wide variety of physiological functions. Over the past two decades, deficiencies of these vitamins have been associated with increased risk of cancer, type II diabetes mellitus and a number of immune system disorders. In addition, there is increasing evidence of interactions between these vitamins, especially between vitamins A and D. As a result of this enhanced clinical association with disease, translational clinical research and laboratory requests for vitamin measurements have significantly increased. These laboratory requests include measurement of 25-OHD (vitamin D), retinol (vitamin A) and α-tocopherol (vitamin E); the most accepted blood indicators for the assessment of body fat-soluble vitamin (FSV) status. There are significant obstacles to precise FSV measurement in blood. These obstacles include their physical and chemical properties, incomplete standardisation of measurement and limitations in the techniques that are currently used for quantification. The aim of this review is to briefly outline the metabolism and interactions of FSV as a prelude to identifying the current challenges for the quantification of blood vitamins A, D and E.

Strategies for Distinguishing Abiotic Chemistry from Martian Biochemistry in Samples Returned from Mars

NASA Technical Reports Server (NTRS)

Glavin, D. P.; Burton, A. S.; Callahan, M. P.; Elsila, J. E.; Stern, J. C.; Dworkin, J. P.

2012-01-01

A key goal in the search for evidence of extinct or extant life on Mars will be the identification of chemical biosignatures including complex organic molecules common to all life on Earth. These include amino acids, the monomer building blocks of proteins and enzymes, and nucleobases, which serve as the structural basis of information storage in DNA and RNA. However, many of these organic compounds can also be formed abiotically as demonstrated by their prevalence in carbonaceous meteorites [1]. Therefore, an important challenge in the search for evidence of life on Mars will be distinguishing between abiotic chemistry of either meteoritic or martian origin from any chemical biosignatures from an extinct or extant martian biota. Although current robotic missions to Mars, including the 2011 Mars Science Laboratory (MSL) and the planned 2018 ExoMars rovers, will have the analytical capability needed to identify these key classes of organic molecules if present [2,3], return of a diverse suite of martian samples to Earth would allow for much more intensive laboratory studies using a broad array of extraction protocols and state-of-theart analytical techniques for bulk and spatially resolved characterization, molecular detection, and isotopic and enantiomeric compositions that may be required for unambiguous confirmation of martian life. Here we will describe current state-of-the-art laboratory analytical techniques that have been used to characterize the abundance and distribution of amino acids and nucleobases in meteorites, Apollo samples, and comet- exposed materials returned by the Stardust mission with an emphasis on their molecular characteristics that can be used to distinguish abiotic chemistry from biochemistry as we know it. The study of organic compounds in carbonaceous meteorites is highly relevant to Mars sample return analysis, since exogenous organic matter should have accumulated in the martian regolith over the last several billion years and the analytical techniques previously developed for the study of extraterrestrial materials can be applied to martian samples.

Complementing Neurophysiology Education for Developing Countries via Cost-Effective Virtual Labs: Case Studies and Classroom Scenarios.

PubMed

Diwakar, Shyam; Parasuram, Harilal; Medini, Chaitanya; Raman, Raghu; Nedungadi, Prema; Wiertelak, Eric; Srivastava, Sanjeeva; Achuthan, Krishnashree; Nair, Bipin

2014-01-01

Classroom-level neuroscience experiments vary from detailed protocols involving chemical, physiological and imaging techniques to computer-based modeling. The application of Information and Communication Technology (ICT) is revolutionizing the current laboratory scenario in terms of active learning especially for distance education cases. Virtual web-based labs are an asset to educational institutions confronting economic issues in maintaining equipment, facilities and other conditions needed for good laboratory practice. To enhance education, we developed virtual laboratories in neuroscience and explored their first-level use in (Indian) University education in the context of developing countries. Besides using interactive animations and remotely-triggered experimental devices, a detailed mathematical simulator was implemented on a web-based software platform. In this study, we focused on the perceptions of technology adoption for a virtual neurophysiology laboratory as a new pedagogy tool for complementing college laboratory experience. The study analyses the effect of virtual labs on users assessing the relationship between cognitive, social and teaching presence. Combining feedback from learners and teachers, the study suggests enhanced motivation for students and improved teaching experience for instructors.

Adaptive laboratory evolution – principles and applications for biotechnology

PubMed Central

2013-01-01

Adaptive laboratory evolution is a frequent method in biological studies to gain insights into the basic mechanisms of molecular evolution and adaptive changes that accumulate in microbial populations during long term selection under specified growth conditions. Although regularly performed for more than 25 years, the advent of transcript and cheap next-generation sequencing technologies has resulted in many recent studies, which successfully applied this technique in order to engineer microbial cells for biotechnological applications. Adaptive laboratory evolution has some major benefits as compared with classical genetic engineering but also some inherent limitations. However, recent studies show how some of the limitations may be overcome in order to successfully incorporate adaptive laboratory evolution in microbial cell factory design. Over the last two decades important insights into nutrient and stress metabolism of relevant model species were acquired, whereas some other aspects such as niche-specific differences of non-conventional cell factories are not completely understood. Altogether the current status and its future perspectives highlight the importance and potential of adaptive laboratory evolution as approach in biotechnological engineering. PMID:23815749

Complementing Neurophysiology Education for Developing Countries via Cost-Effective Virtual Labs: Case Studies and Classroom Scenarios

PubMed Central

Diwakar, Shyam; Parasuram, Harilal; Medini, Chaitanya; Raman, Raghu; Nedungadi, Prema; Wiertelak, Eric; Srivastava, Sanjeeva; Achuthan, Krishnashree; Nair, Bipin

2014-01-01

Classroom-level neuroscience experiments vary from detailed protocols involving chemical, physiological and imaging techniques to computer-based modeling. The application of Information and Communication Technology (ICT) is revolutionizing the current laboratory scenario in terms of active learning especially for distance education cases. Virtual web-based labs are an asset to educational institutions confronting economic issues in maintaining equipment, facilities and other conditions needed for good laboratory practice. To enhance education, we developed virtual laboratories in neuroscience and explored their first-level use in (Indian) University education in the context of developing countries. Besides using interactive animations and remotely-triggered experimental devices, a detailed mathematical simulator was implemented on a web-based software platform. In this study, we focused on the perceptions of technology adoption for a virtual neurophysiology laboratory as a new pedagogy tool for complementing college laboratory experience. The study analyses the effect of virtual labs on users assessing the relationship between cognitive, social and teaching presence. Combining feedback from learners and teachers, the study suggests enhanced motivation for students and improved teaching experience for instructors. PMID:24693260

MEASUREMENT OF THE CURRENT AND SYMMETRY OF THE IMPACT LINER ON THE NTLX EXPERIMENTS

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

J. STOKES; J. PARKER; ET AL

A series of four liner implosion experiments, denoted the Near Term Liner Experiments (NTLX) was recently conducted on the Shiva Star capacitor bank at the Air Force Research Laboratory (AFRL). Measurement of the driving currents in these experiments is required for post-shot analysis of the liner implosion and experiments conducted in the target cylinder. A Faraday rotation measurement was fielded on Shiva Star to measure the current and compare with the current measured by a Rogowski coil technique. The Faraday rotation technique measured the 16 MA currents in these experiments with better than 1% precision. In addition, six B-dot probesmore » were fielded at equal angles around a circle in the powerflow channel outside the liner to measure the symmetry of the liner impact on the target cylinder. The B-dot probes measure the local I-dot, which has a jump when the liner impacts the target cylinder. A high-pass filter allows one to measure this jump more accurately. From the relative timing of the jump signals, the offset of the liner axis and the circularity of liner are inferred.« less

Lung imaging of laboratory rodents in vivo

NASA Astrophysics Data System (ADS)

Cody, Dianna D.; Cavanaugh, Dawn; Price, Roger E.; Rivera, Belinda; Gladish, Gregory; Travis, Elizabeth

2004-10-01

We have been acquiring respiratory-gated micro-CT images of live mice and rats for over a year with our General Electric (formerly Enhanced Vision Systems) hybrid scanner. This technique is especially well suited for the lung due to the inherent high tissue contrast. Our current studies focus on the assessment of lung tumors and their response to experimental agents, and the assessment of lung damage due to chemotherapy agents. We have recently installed a custom-built dual flat-panel cone-beam CT scanner with the ability to scan laboratory animals that vary in size from mice to large dogs. A breath-hold technique is used in place of respiratory gating on this scanner. The objective of this pilot study was to converge on scan acquisition parameters and optimize the visualization of lung damage in a mouse model of fibrosis. Example images from both the micro-CT scanner and the flat-panel CT scanner will be presented, as well as preliminary data describing spatial resolution, low contrast resolution, and radiation dose parameters.

Introduction to the mining of clinical data.

PubMed

Harrison, James H

2008-03-01

The increasing volume of medical data online, including laboratory data, represents a substantial resource that can provide a foundation for improved understanding of disease presentation, response to therapy, and health care delivery processes. Data mining supports these goals by providing a set of techniques designed to discover similarities and relationships between data elements in large data sets. Currently, medical data have several characteristics that increase the difficulty of applying these techniques, although there have been notable medical data mining successes. Future developments in integrated medical data repositories, standardized data representation, and guidelines for the appropriate research use of medical data will decrease the barriers to mining projects.

Melt-Flow Behaviours of Thermoplastic Materials under Fire Conditions: Recent Experimental Studies and Some Theoretical Approaches

PubMed Central

Joseph, Paul; Tretsiakova-McNally, Svetlana

2015-01-01

Polymeric materials often exhibit complex combustion behaviours encompassing several stages and involving solid phase, gas phase and interphase. A wide range of qualitative, semi-quantitative and quantitative testing techniques are currently available, both at the laboratory scale and for commercial purposes, for evaluating the decomposition and combustion behaviours of polymeric materials. They include, but are not limited to, techniques such as: thermo-gravimetric analysis (TGA), oxygen bomb calorimetry, limiting oxygen index measurements (LOI), Underwriters Laboratory 94 (UL-94) tests, cone calorimetry, etc. However, none of the above mentioned techniques are capable of quantitatively deciphering the underpinning physiochemical processes leading to the melt flow behaviour of thermoplastics. Melt-flow of polymeric materials can constitute a serious secondary hazard in fire scenarios, for example, if they are present as component parts of a ceiling in an enclosure. In recent years, more quantitative attempts to measure the mass loss and melt-drip behaviour of some commercially important chain- and step-growth polymers have been accomplished. The present article focuses, primarily, on the experimental and some theoretical aspects of melt-flow behaviours of thermoplastics under heat/fire conditions. PMID:28793746

The validation of the Z-Scan technique for the determination of plasma glucose

NASA Astrophysics Data System (ADS)

Alves, Sarah I.; Silva, Elaine A. O.; Costa, Simone S.; Sonego, Denise R. N.; Hallack, Maira L.; Coppini, Ornela L.; Rowies, Fernanda; Azzalis, Ligia A.; Junqueira, Virginia B. C.; Pereira, Edimar C.; Rocha, Katya C.; Fonseca, Fernando L. A.

2013-11-01

Glucose is the main energy source for the human body. The concentration of blood glucose is regulated by several hormones including both antagonists: insulin and glucagon. The quantification of glucose in the blood is used for diagnosing metabolic disorders of carbohydrates, such as diabetes, idiopathic hypoglycemia and pancreatic diseases. Currently, the methodology used for this determination is the enzymatic colorimetric with spectrophotometric. This study aimed to validate the use of measurements of nonlinear optical properties of plasma glucose via the Z-Scan technique. For this we used samples of calibrator patterns that simulate commercial samples of patients (ELITech ©). Besides calibrators, serum glucose levels within acceptable reference values (normal control serum - Brazilian Society of Clinical Pathology and Laboratory Medicine) and also overestimated (pathological control serum - Brazilian Society of Clinical Pathology and Laboratory Medicine) were used in the methodology proposal. Calibrator dilutions were performed and determined by the Z-Scan technique for the preparation of calibration curve. In conclusion, Z-Scan method can be used to determinate glucose levels in biological samples with enzymatic colorimetric reaction and also to apply the same quality control parameters used in biochemistry clinical.

Melt-Flow Behaviours of Thermoplastic Materials under Fire Conditions: Recent Experimental Studies and Some Theoretical Approaches.

PubMed

Joseph, Paul; Tretsiakova-McNally, Svetlana

2015-12-15

Polymeric materials often exhibit complex combustion behaviours encompassing several stages and involving solid phase, gas phase and interphase. A wide range of qualitative, semi-quantitative and quantitative testing techniques are currently available, both at the laboratory scale and for commercial purposes, for evaluating the decomposition and combustion behaviours of polymeric materials. They include, but are not limited to, techniques such as: thermo-gravimetric analysis (TGA), oxygen bomb calorimetry, limiting oxygen index measurements (LOI), Underwriters Laboratory 94 (UL-94) tests, cone calorimetry, etc. However, none of the above mentioned techniques are capable of quantitatively deciphering the underpinning physiochemical processes leading to the melt flow behaviour of thermoplastics. Melt-flow of polymeric materials can constitute a serious secondary hazard in fire scenarios, for example, if they are present as component parts of a ceiling in an enclosure. In recent years, more quantitative attempts to measure the mass loss and melt-drip behaviour of some commercially important chain- and step-growth polymers have been accomplished. The present article focuses, primarily, on the experimental and some theoretical aspects of melt-flow behaviours of thermoplastics under heat/fire conditions.

Clinical Relevance of Coronary Fractional Flow Reserve: Art-of-state

PubMed Central

Adiputra, Yohanes; Chen, Shao-Liang

2015-01-01

Objective: The objective was to delineate the current knowledge of fractional flow reserve (FFR) in terms of definition, features, clinical applications, and pitfalls of measurement of FFR. Data Sources: We searched database for primary studies published in English. The database of National Library of Medicine (NLM), MEDLINE, and PubMed up to July 2014 was used to conduct a search using the keyword term “FFR”. Study Selection: The articles about the definition, features, clinical application, and pitfalls of measurement of FFR were identified, retrieved, and reviewed. Results: Coronary pressure-derived FFR rapidly assesses the hemodynamic significance of individual coronary artery lesions and can readily be performed in the catheterization laboratory. The use of FFR has been shown to effectively guide coronary revascularization procedures leading to improved patient outcomes. Conclusions: FFR is a valuable tool to determine the functional significance of coronary stenosis. It combines physiological and anatomical information, and can be followed immediately by percutaneous coronary intervention (PCI) if necessary. The technique of FFR measurement can be performed easily, rapidly, and safely in the catheterization laboratory. By systematic use of FFR in dubious stenosis and multi-vessel disease, PCI can be made an even more effective and better treatment than it is currently. The current clinical evidence for FFR should encourage cardiologists to use this tool in the catheterization laboratory. PMID:25963364

Calibration, reconstruction, and rendering of cylindrical millimeter-wave image data

NASA Astrophysics Data System (ADS)

Sheen, David M.; Hall, Thomas E.

2011-05-01

Cylindrical millimeter-wave imaging systems and technology have been under development at the Pacific Northwest National Laboratory (PNNL) for several years. This technology has been commercialized, and systems are currently being deployed widely across the United States and internationally. These systems are effective at screening for concealed items of all types; however, new sensor designs, image reconstruction techniques, and image rendering algorithms could potentially improve performance. At PNNL, a number of specific techniques have been developed recently to improve cylindrical imaging methods including wideband techniques, combining data from full 360-degree scans, polarimetric imaging techniques, calibration methods, and 3-D data visualization techniques. Many of these techniques exploit the three-dimensionality of the cylindrical imaging technique by optimizing the depth resolution of the system and using this information to enhance detection. Other techniques, such as polarimetric methods, exploit scattering physics of the millimeter-wave interaction with concealed targets on the body. In this paper, calibration, reconstruction, and three-dimensional rendering techniques will be described that optimize the depth information in these images and the display of the images to the operator.

Direct-current arc and alternating-current spark emission spectrographic field methods for the semiquantitative analysis of geologic materials

USGS Publications Warehouse

Grimes, D.J.; Marranzino, A.P.

1968-01-01

Two spectrographic methods are used in mobile field laboratories of the U. S. Geological Survey. In the direct-current arc method, the ground sample is mixed with graphite powder, packed into an electrode crater, and burned to completion. Thirty elements are determined. In the spark method, the sample, ground to pass a 150-mesh screen, is digested in hydrofluoric acid followed by evaporation to dryness and dissolution in aqua regia. The solution is fed into the spark gap by means of a rotating-disk electrode arrangement and is excited with an alternating-current spark discharge. Fourteen elements are determined. In both techniques, light is recorded on Spectrum Analysis No. 1, 35-millimeter film, and the spectra are compared visually with those of standard films.

Simple and rapid system for two-dimensional gel electrophoresis technique: A laboratory exercise for high school students.

PubMed

Maurye, Praveen; Basu, Arpita; Biswas, Jayanta Kumar; Bandyopadhyay, Tapas Kumar; Naskar, Malay

2018-02-28

Polyacrylamide gel electrophoresis (PAGE) is the most classical technique favored worldwide for resolution of macromolecules in many biochemistry laboratories due to its incessant advanced developments and wide modifications. These ever-growing advancements in the basic laboratory equipments lead to emergence of many expensive, complex, and tricky laboratory equipments. Practical courses of biochemistry at high school or undergraduate levels are often affected by these complications. Two dimensional gel electrophoresis technique (2D-PAGE) used for resolving thousands of proteins in a gel is a combination of isoelectric focusing (first dimension gel electrophoresis technique) and sodium-dodecylsulphate PAGE (second dimension gel electrophoresis technique or SDS-PAGE). Two different laboratory equipments are needed to carry out effective 2D-PAGE technique, which also invites extra burden to the school laboratory. Here, we describe a low cost, time saving and simple gel cassette for protein 2D-PAGE technique that uses easily fabricated components and routine off-the-shelf materials. The performance of the apparatus was verified in a practical exercise by a group of high school students with positive outcomes. © 2018 by The International Union of Biochemistry and Molecular Biology, 2018. © 2018 The International Union of Biochemistry and Molecular Biology.

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…

Current and Prospective Methods for Plant Disease Detection

PubMed Central

Fang, Yi; Ramasamy, Ramaraja P.

2015-01-01

Food losses due to crop infections from pathogens such as bacteria, viruses and fungi are persistent issues in agriculture for centuries across the globe. In order to minimize the disease induced damage in crops during growth, harvest and postharvest processing, as well as to maximize productivity and ensure agricultural sustainability, advanced disease detection and prevention in crops are imperative. This paper reviews the direct and indirect disease identification methods currently used in agriculture. Laboratory-based techniques such as polymerase chain reaction (PCR), immunofluorescence (IF), fluorescence in-situ hybridization (FISH), enzyme-linked immunosorbent assay (ELISA), flow cytometry (FCM) and gas chromatography-mass spectrometry (GC-MS) are some of the direct detection methods. Indirect methods include thermography, fluorescence imaging and hyperspectral techniques. Finally, the review also provides a comprehensive overview of biosensors based on highly selective bio-recognition elements such as enzyme, antibody, DNA/RNA and bacteriophage as a new tool for the early identification of crop diseases. PMID:26287253

Array Technology for Terahertz Imaging

NASA Technical Reports Server (NTRS)

Reck, Theodore; Siles, Jose; Jung, Cecile; Gill, John; Lee, Choonsup; Chattopadhyay, Goutam; Mehdi, Imran; Cooper, Ken

2012-01-01

Heterodyne terahertz (0.3 - 3THz) imaging systems are currently limited to single or a low number of pixels. Drastic improvements in imaging sensitivity and speed can be achieved by replacing single pixel systems with an array of detectors. This paper presents an array topology that is being developed at the Jet Propulsion Laboratory based on the micromachining of silicon. This technique fabricates the array's package and waveguide components by plasma etching of silicon, resulting in devices with precision surpassing that of current metal machining techniques. Using silicon increases the versatility of the packaging, enabling a variety of orientations of circuitry within the device which increases circuit density and design options. The design of a two-pixel transceiver utilizing a stacked architecture is presented that achieves a pixel spacing of 10mm. By only allowing coupling from the top and bottom of the package the design can readily be arrayed in two dimensions with a spacing of 10mm x 18mm.

AST Combustion Workshop: Diagnostics Working Group Report

NASA Technical Reports Server (NTRS)

Locke, Randy J.; Hicks, Yolanda R.; Hanson, Ronald K.

1996-01-01

A workshop was convened under NASA's Advanced Subsonics Technologies (AST) Program. Many of the principal combustion diagnosticians from industry, academia, and government laboratories were assembled in the Diagnostics/Testing Subsection of this workshop to discuss the requirements and obstacles to the successful implementation of advanced diagnostic techniques to the test environment of the proposed AST combustor. The participants, who represented the major relevant areas of advanced diagnostic methods currently applied to combustion and related fields, first established the anticipated AST combustor flowfield conditions. Critical flow parameters were then examined and prioritized as to their importance to combustor/fuel injector design and manufacture, environmental concerns, and computational interests. Diagnostic techniques were then evaluated in terms of current status, merits and obstacles for each flow parameter. All evaluations are presented in tabular form and recommendations are made on the best-suited diagnostic method to implement for each flow parameter in order of applicability and intrinsic value.

A water-vapor radiometer error model. [for ionosphere in geodetic microwave techniques

NASA Technical Reports Server (NTRS)

Beckman, B.

1985-01-01

The water-vapor radiometer (WVR) is used to calibrate unpredictable delays in the wet component of the troposphere in geodetic microwave techniques such as very-long-baseline interferometry (VLBI) and Global Positioning System (GPS) tracking. Based on experience with Jet Propulsion Laboratory (JPL) instruments, the current level of accuracy in wet-troposphere calibration limits the accuracy of local vertical measurements to 5-10 cm. The goal for the near future is 1-3 cm. Although the WVR is currently the best calibration method, many instruments are prone to systematic error. In this paper, a treatment of WVR data is proposed and evaluated. This treatment reduces the effect of WVR systematic errors by estimating parameters that specify an assumed functional form for the error. The assumed form of the treatment is evaluated by comparing the results of two similar WVR's operating near each other. Finally, the observability of the error parameters is estimated by covariance analysis.

Cophasing techniques for extremely large telescopes

NASA Astrophysics Data System (ADS)

Devaney, Nicholas; Schumacher, Achim

2004-07-01

The current designs of the majority of ELTs envisage that at least the primary mirror will be segmented. Phasing of the segments is therefore a major concern, and a lot of work is underway to determine the most suitable techniques. The techniques which have been developed are either wave optics generalizations of classical geometric optics tests (e.g. Shack-Hartmann and curvature sensing) or direct interferometric measurements. We present a review of the main techniques proposed for phasing and outline their relative merits. We consider problems which are specific to ELTs, e.g. vignetting of large parts of the primary mirror by the secondary mirror spiders, and the need to disentangle phase errors arising in different segmented mirrors. We present improvements in the Shack-Hartmann and curvature sensing techniques which allow greater precision and range. Finally, we describe a piston plate which simulates segment phasing errors and show the results of laboratory experiments carried out to verify the precision of the Shack-Hartmann technique.

Facilities and Methods Used in Full-scale Airplane Crash-fire Investigation

NASA Technical Reports Server (NTRS)

Black, Dugald O.

1952-01-01

The facilities and the techniques employed in the conduct of full scale airplane crash-fire studies currently being conducted at the NACA Lewis laboratory are discussed herein. This investigation is part of a comprehensive study of the airplane crash-fire problem. The crash configuration chosen, the general physical layout of the crash site, the test methods, the instrumentation, the data-recording systems, and the post-crash examination procedure are described

Interactions of Small-Scale Physical Mixing Processes with the Structure, Morphology and Bloom Dynamics and Optics of Non-Spheroid Phytoplankton

DTIC Science & Technology

2001-09-30

microscopic imaging techniques, and microscopic video- cinematography protocols for both phytoplankton and zooplankton for use in current laboratory...phytoplankton, zooplankton and bioluminescence papers, and examined data/figures for layered structures. Imaging and Cinematography : Off-the-shelf...to preview it as a work-in-progress, email me (jrines@gso.uri.edu), and I will provide you with a temporary URL. Imaging and Cinematography

Testing technology

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

Not Available

1993-10-01

This bulletin from Sandia National Laboratories presents current research highlights in testing technology. Ion microscopy offers new nondestructive testing technique that detects high resolution invisible defects. An inexpensive thin-film gauge checks detonators on centrifuge. Laser trackers ride the range and track helicopters at low-level flights that could not be detected by radar. Radiation transport software predicts electron/photon effects via cascade simulation. Acoustic research in noise abatement will lead to quieter travelling for Bay Area Rapid Transport (BART) commuters.

Proceedings of the flat-plate solar array project research forum on photovoltaic metallization systems

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

None

1983-11-15

A Photovoltaic Metallization Research Forum, under the sponsorship of the Jet Propulsion Laboratory's Flat-Plate Solar Array Project and the US Department of Energy, was held March 16-18, 1983 at Pine Mountain, Georgia. The Forum consisted of five sessions, covering (1) the current status of metallization systems, (2) system design, (3) thick-film metallization, (4) advanced techniques and (5) future metallization challenges. Twenty-three papers were presented.

Practical diagnostic testing for human immunodeficiency virus.

PubMed Central

Jackson, J B; Balfour, H H

1988-01-01

Since the discovery of human immunodeficiency virus (HIV) as the causative agent of acquired immunodeficiency syndrome in 1983, there has been a proliferation of diagnostic tests. These assays can be used to detect the presence of HIV antibody, HIV antigen, HIV ribonucleic and deoxyribonucleic acids, and HIV reverse transcriptase. Enzyme-linked immunosorbent assays, Western blot, radioimmunoprecipitation assays, indirect immunofluorescence assays, reverse transcriptase assays, and several molecular hybridization techniques are currently available. Enzyme-linked immunosorbent, Western blot, and indirect immunofluorescence assays for HIV antibody are very sensitive, specific, and adaptable to most laboratories. An enzyme-linked immunosorbent assay for HIV antigen is also readily adaptable to most laboratories and will be commercially available soon. While the other assays are more tedious, they are valuable confirmatory tests and are suitable for reference laboratories. The biohazards of performing HIV testing can be minimized with proper biosafety measures. Images PMID:3060241

Indirect Charged Particle Detection: Concepts and a Classroom Demonstration

NASA Astrophysics Data System (ADS)

Childs, Nicholas B.; Horányi, Mihály; Collette, Andrew

2013-11-01

We describe the principles of macroscopic charged particle detection in the laboratory and their connections to concepts taught in the physics classroom. Electrostatic dust accelerator systems, capable of launching charged dust grains at hypervelocities (1-100 km/s), are a critical tool for space exploration. Dust grains in space typically have large speeds relative to the probes or satellites that encounter them. Development and testing of instruments that look for dust in space therefore depends critically on the availability of fast, well-characterized dust grains in the laboratory. One challenge for the experimentalist is to precisely measure the speed and mass of laboratory dust particles without disturbing them. Detection systems currently in use exploit the well-known effect of image charge to register the passage of dust grains without changing their speed or mass. We describe the principles of image charge detection and provide a simple classroom demonstration of the technique using soup cans and pith balls.

Laser and Optical Subsystem for NASA's Cold Atom Laboratory

NASA Astrophysics Data System (ADS)

Kohel, James; Kellogg, James; Elliott, Ethan; Krutzik, Markus; Aveline, David; Thompson, Robert

2016-05-01

We describe the design and validation of the laser and optics subsystem for NASA's Cold Atom Laboratory (CAL), a multi-user facility being developed at NASA's Jet Propulsion Laboratory for studies of ultra-cold quantum gases in the microgravity environment of the International Space Station. Ultra-cold atoms will be generated in CAL by employing a combination of laser cooling techniques and evaporative cooling in a microchip-based magnetic trap. Laser cooling and absorption imaging detection of bosonic mixtures of 87 Rb and 39 K or 41 K will be accomplished using a high-power (up to 500 mW ex-fiber), frequency-agile dual wavelength (767 nm and 780 nm) laser and optical subsystem. The CAL laser and optical subsystem also includes the capability to generate high-power multi-frequency optical pulses at 784.87 nm to realize a dual-species Bragg atom interferometer. Currently at Humboldt-Universität zu Berlin.

Propagation of a turbidity current in confined geometries

NASA Astrophysics Data System (ADS)

Silvestre, Nuno; Salgueiro, Dora; Franca, Mário J.; Ferreira, Rui M. L.

2017-04-01

Sedimentation in reservoirs due to turbidity currents originates problems of loss of storage capacity as well as clogging of outlets/intakes. These currents are driven by the difference in specific weight between the current itself and the surrounding fluid, due to the presence of particles in suspension. As a gravity current, the main properties of these phenomena has been investigated by several authors since the 1970´s. Despite driven by a simple mechanism, the propagation of these currents can become more complex owing to the influence of factors such as geometry, bed roughness and other non-uniform elements. However, the majority of conducted studies has been focused in characterising only the influence of density imbalance. The propagation of a density current in confined geometries and the influence of bed roughness is herein investigated, through laboratory experiments carried out at the Laboratory of Hydraulics and Environment of Instituto Superior Técnico, Lisbon. The density currents were generated with brine to allow for visualization and velocity measurement. The laboratory experiments comprised point and continuous release of a dense NaCl mixture with a tracer (Rhodamine WT), with a density equal to 1028 g/L, into a tank with resting freshwater (1000 g/L). The transport and the mixing processes were recorded with high-speed video. The mass distribution was obtained through a photometric methodology and the Particle Image Velocimetry (PIV) technique was used to measure the instantaneous flow velocity fields and the depth of the density current. Both methodologies were used to measure different plan views of the phenomena, including profile and top views, for different regions, near-field and far-field. Different bed roughness were studied, including smooth and rough bed. The facility was designed with the objective to generate a complex 2D flow with an advancing wave front but also shocks reflected from the walls. As the image analysis technique provided high-resolution images, the front velocity in the far field was tracked with an algorithm that captured its geometry with great accuracy (including, for instance, the lobe and cleft formation). The temporal analysis of the velocity signal revealed great "oscillations" that are beyond the scale/influence of the irregularity of lobes and clefts. This sloshing effect is assessed and discussed. The results obtained provide data with high spatial and temporal resolution that can lead to a better understanding of the mechanisms involved in such flows. Thus, these results can be used for a proper modelling and the development of mitigation measures against the adverse effects of density currents. This research was partially supported by Portuguese and European funds, within programs COMPETE2020 and PORL-FEDER, through project PTDC/ECM-HID/6387/2014 granted by the National Foundation for Science and Technology (FCT).

Solid-Cryogen Cooling Technique for Superconducting Magnets of NMR and MRI

NASA Astrophysics Data System (ADS)

Iwasa, Yukikazu; Bascuñán, Juan; Hahn, Seungyong; Park, Dong Keun

This paper describes a solid-cryogen cooling technique currently being developed at the M.I.T. Francis Bitter Magnet Laboratory for application to superconducting magnets of NMR and MRI. The technique is particularly appropriate for "dry" magnets that do not rely on liquid cryogen, e.g., liquid helium (LHe), as their primary cooling sources. In addition, the advantages of a cryocirculator (a combination of a cryocooler and a working fluid circulator) over a cryocooler as the primary cooling source for dry magnets are described. The four magnets described here, all incorporating this cooling technique described and currently being developed at the FBML, are: 1) a solid-nitrogen (SN2)-cooled Nb3Sn 500-MHz/200-mm MRI magnet with an operating temperature range between 4.2 K (nominal) and 6.0 K (maximum with its primary cooling source off); 2) an SN2-cooled MgB2 0.5-T/800-mm MRI magnet, 1015 K; 3) an SN2-cooled compact YBCO "annulus" 100-MHz/9-mm NMR magnet, 10-15 K; 4) an SN2-cooled 1.5T/75-mm NbTi magnet for slow magic-angle-spinning NMR/MRI, 4.5-5.5 K.

Demonstration of Laser Induced Acoustic Desoprtion - Chemical Ionization Mass Spectrometry (LIAD-CIMS) for Fragment-Free Measurements of Organic Aerosol Molecular Composition

NASA Astrophysics Data System (ADS)

Browne, E. C.; Abdelhamid, A.; Berry, J.; Alton, M.

2017-12-01

Organic compounds account for a significant portion of fine atmospheric aerosol. Current analytical techniques have provided insights on organic aerosol (OA) sources, composition, and chemical modification pathways. Despite this knowledge, large uncertainties remain and hinder our understanding of aerosol impacts on climate, air quality, and health. Measuring OA composition is challenging due to the complex chemical composition and the wide variation in the properties (e.g., vapor pressure, solubility, reactivity) of organic compounds. In many current measurement techniques, the ability to chemically resolve and quantify OA components is complicated by molecular decomposition, matrix effects, and/or preferential ionization mechanisms. Here, we utilize a novel desorption technique, laser induced acoustic desorption (LIAD), that generates fragment-free, neutral gas-phase molecules. We couple LIAD with a high-resolution chemical ionization mass spectrometer (CIMS) to provide molecular composition OA measurements. Through a series of laboratory experiments, we demonstrate the ability of this technique to measure large, thermally labile species without fragmentation/thermal decomposition. We discuss quantification and detection limits of this technique. We compare LIAD-CIMS measurements with thermal desorption-CIMS measurements using off-line measurements of ambient aerosol collected in Boulder, CO. Lastly, we discuss future development for on-line measurements of OA using LIAD-CIMS.

Explosive Contamination from Substrate Surfaces: Differences and Similarities in Contamination Techniques using RDX and C-4

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

C.J. Miller; T.S. Yoder

The amount of time that an explosive is present on the surface of a material is dependent upon the original amount of explosive on the surface, temperature, humidity, rain, etc. This laboratory study focused on looking at similarities and differences in three different surface contamination techniques that are used when performance testing explosive trace detection equipment in an attempt to determine how effective the techniques are at replicating actual field samples. The three techniques used were dry transfer deposition of solutions using the Transportation Security Laboratory (TSL) patented dry transfer techniques (US patent 6470730), direct deposition of explosive standards, andmore » fingerprinting of actual explosives. Explosives were deposited on the surface of one of five substrates using one of the three different deposition techniques. The process was repeated for each surface type using each contamination technique. The surface types used were: 50% cotton/50% polyester as found in T-shirts, 100% cotton with a smooth surface such as that found in a cotton dress shirt, 100% cotton on a rough surface such as that found on canvas or denim, suede leather such as might be found on jackets, purses, or shoes, and metal obtained from a car hood at a junk yard. The samples were not pre-cleaned prior to testing and contained sizing agents, and in the case of the metal, oil and dirt. The substrates were photographed using a Zeiss Discover V12 stereoscope with Axiocam ICc1 3 megapixel digital camera to determine the difference in the crystalline structure and surface contamination in an attempt to determine differences and similarities associated with current contamination techniques.« less

Mass Storage and Retrieval at Rome Laboratory

NASA Technical Reports Server (NTRS)

Kann, Joshua L.; Canfield, Brady W.; Jamberdino, Albert A.; Clarke, Bernard J.; Daniszewski, Ed; Sunada, Gary

1996-01-01

As the speed and power of modern digital computers continues to advance, the demands on secondary mass storage systems grow. In many cases, the limitations of existing mass storage reduce the overall effectiveness of the computing system. Image storage and retrieval is one important area where improved storage technologies are required. Three dimensional optical memories offer the advantage of large data density, on the order of 1 Tb/cm(exp 3), and faster transfer rates because of the parallel nature of optical recording. Such a system allows for the storage of multiple-Gbit sized images, which can be recorded and accessed at reasonable rates. Rome Laboratory is currently investigating several techniques to perform three-dimensional optical storage including holographic recording, two-photon recording, persistent spectral-hole burning, multi-wavelength DNA recording, and the use of bacteriorhodopsin as a recording material. In this paper, the current status of each of these on-going efforts is discussed. In particular, the potential payoffs as well as possible limitations are addressed.

Affordable proteomics: the two-hybrid systems.

PubMed

Gillespie, Marc

2003-06-01

Numerous proteomic methodologies exist, but most require a heavy investment in expertise and technology. This puts these approaches out of reach for many laboratories and small companies, rarely allowing proteomics to be used as a pilot approach for biomarker or target identification. Two proteomic approaches, 2D gel electrophoresis and the two-hybrid systems, are currently available to most researchers. The two-hybrid systems, though accommodating to large-scale experiments, were originally designed as practical screens, that by comparison to current proteomics tools were small-scale, affordable and technically feasible. The screens rapidly generated data, identifying protein interactions that were previously uncharacterized. The foundation for a two-hybrid proteomic investigation can be purchased as separate kits from a number of companies. The true power of the technique lies not in its affordability, but rather in its portability. The two-hybrid system puts proteomics back into laboratories where the output of the screens can be evaluated by researchers with experience in the particular fields of basic research, cancer biology, toxicology or drug development.

MFI ratio estimation of ZAP-70 in B-CLL by flow cytometry can be improved by considering the isotype-matched antibody signal.

PubMed

Marquez, M-E; Deglesne, P-A; Suarez, G; Romano, E

2011-04-01

The IgV(H) mutational status of B-cell chronic lymphocytic leukemia (B-CLL) is of prognostic value. Expression of ZAP-70 in B-CLL is a surrogate marker for IgV(H) unmutated (UM). As determination of IgV(H) mutational status involves a methodology currently unavailable for most clinical laboratories, it is important to have available a reliable technique for ZAP-70 estimation in B-CLL. Flow cytometry (FC) is a convenient technique for this purpose. However, there is still no adequate way for data analysis, which would prevent the assignment of false positive or negative expression. We have modified the currently most accepted technique, which uses the ratio of the mean fluorescent index (MFI) of B-CLL to T cells. The MFI for parallel antibody isotype staining is subtracted from the ZAP-70 MFI of both B-CLL and T cells. We validated this technique comparing the results obtained for ZAP-70 expression by FC with those obtained with quantitative PCR for the same patients. We applied the technique in a series of 53 patients. With this modification, a better correlation between ZAP-70 expression and IgV(H) UM was obtained. Thus, the MFI ratio B-CLL/T cell corrected by isotype is a reliable analysis technique to estimate ZAP-70 expression in B-CLL. © 2010 Blackwell Publishing Ltd.

Homogeneity of CdZnTe detectors

NASA Astrophysics Data System (ADS)

Hermon, H.; Schieber, M.; James, R. B.; Lund, J.; Antolak, A. J.; Morse, D. H.; Kolesnikov, N. N. P.; Ivanov, Y. N.; Goorsky, M. S.; Yoon, H.; Toney, J.; Schlesinger, T. E.

1998-02-01

We describe the current state of nuclear radiation detectors produced from single crystals of Cd 1- xZn xTe(CZT), with 0.04 < x < 0.4, grown by the vertical high pressure Bridgman (VHPB) method. The crystals investigated were grown commercially both in the USA and at the Institute of Solid State Physics, Chernogolska, Russia. The CZT was evaluated by Sandia National Laboratories and the UCLA and CMU groups using proton-induced X-ray emission (PIXE), X-ray diffraction (XRD), photoluminescence (PL), infrared (IR) transmission microscopy, leakage current measurements and response to nuclear radiation. We discuss the homogeneity of the various CZT crystals based on the results from these measurement techniques.

CYSTIC FIBROSIS: MICROBIOLOGY AND HOST RESPONSE

PubMed Central

Zemanick, Edith T.

2016-01-01

THE EARLIEST DESCRIPTIONS OF LUNG DISEASE IN PEOPLE WITH CYSTIC FIBROSIS (CF) DEMONSTRATED THE INVOLVEMENT OF THREE INTERACTING PATHOPHYSIOLOGICAL ELEMENTS IN CF AIRWAYS: MUCUS OBSTRUCTION, INFLAMMATION, AND INFECTION. OVER THE PAST 7 DECADES, OUR UNDERSTANDING OF CF RESPIRATORY MICROBIOLOGY AND INFLAMMATION HAS EVOLVED WITH THE INTRODUCTION OF NEW TREATMENTS, WITH INCREASED LONGEVITY, AND WITH INCREASINGLY SOPHISTICATED LABORATORY TECHNIQUES. IN THIS CHAPTER, WE WILL REVIEW THE CURRENT STATE OF UNDERSTANDING OF THE ROLES OF INFECTION AND INFLAMMATION AND THEIR ROLES IN DRIVING LUNG DISEASE. WE WILL ALSO DISCUSS HOW THIS CONSTANTLY EVOLVING INFORMATION IS USED TO INFORM CURRENT THERAPEUTIC STRATEGIES, MEASURES AND PREDICTORS OF DISEASE SEVERITY, AND RESEARCH PRIORITIES. PMID:27469179

Purdue Rare Isotope Measurement Laboratory

NASA Astrophysics Data System (ADS)

Caffee, M.; Elmore, D.; Granger, D.; Muzikar, P.

2002-12-01

The Purdue Rare Isotope Measurement Laboratory (PRIME Lab) is a dedicated research and service facility for accelerator mass spectrometry. AMS is an ultra-sensitive analytical technique used to measure low levels of long-lived cosmic-ray-produced and anthropogenic radionuclides, and rare trace elements. We measure 10Be (T1/2 = 1.5 My), 26Al (.702 My), 36Cl (.301 My), and 129I (16 My), in geologic samples. Applications include dating the cosmic-ray-exposure time of rocks on Earth's surface, determining rock and sediment burial ages, measuring the erosion rates of rocks and soils, and tracing and dating ground water. We perform sample preparation and separation chemistries for these radio-nuclides for our internal research activities and for those external researchers not possessing this capability. Our chemical preparation laboratories also serve as training sites for members of the geoscience community developing these techniques at their institutions. Research at Purdue involves collaborators among members of the Purdue Departments of Physics, Earth and Atmospheric Sciences, Chemistry, Agronomy, and Anthropology. We also collaborate and serve numerous scientists from other institutions. We are currently in the process of modernizing the facility with the goals of higher precision for routinely measured radio-nuclides, increased sample throughput, and the development of new measurement capabilities for the geoscience community.

Advanced Ultrafast Spectroscopy for Chemical Detection of Nuclear Fuel Cycle Materials

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

Villa-Aleman, E.; Houk, A.; Spencer, W.

The development of new signatures and observables from processes related to proliferation activities are often related to the development of technologies. In our physical world, the intensity of observables is linearly related to the input drivers (light, current, voltage, etc.). Ultrafast lasers with high peak energies, opens the door to a new regime where the intensity of the observables is not necessarily linear with the laser energy. Potential nonlinear spectroscopic applications include chemical detection via remote sensing through filament generation, material characterization and processing, chemical reaction specificity, surface phenomena modifications, X-ray production, nuclear fusion, etc. The National Security Directorate lasermore » laboratory is currently working to develop new tools for nonproliferation research with femtosecond and picosecond lasers. Prior to this project, we could only achieve laser energies in the 5 nano-Joule range, preventing the study of nonlinear phenomena. To advance our nonproliferation research into the nonlinear regime we require laser pulses in the milli-Joule (mJ) energy range. We have procured and installed a 35 fs-7 mJ laser, operating at one-kilohertz repetition rate, to investigate elemental and molecular detection of materials in the laboratory with potential applications in remote sensing. Advanced, nonlinear Raman techniques will be used to study materials of interest that are in a matrix of many materials and currently with these nonlinear techniques we can achieve greater than three orders of magnitude signal enhancement. This work studying nuclear fuel cycle materials with nonlinear spectroscopies will advance SRNL research capabilities and grow a core capability within the DOE complex.« less

The Significance of A Neglected Romanian Book - "The Methods of the Clinical Laboratory", by Ioan Manta and Alexandru Ciplea.

PubMed

Barsu, Cristian

2017-04-06

"The Methods of Clinical Laboratory" was the first comprehensive Romanian book in the medical laboratory field, having utility in clinical practice. It was written by Prof. Ioan Manta (1900-1979) and Alexandru Ciplea (1912-1988), both from the Cluj Faculty of Medicine. The volume was published for the first time in 1944, during the refuge of this Faculty in Sibiu, and for the second time in 1947, in Cluj. Our aim is to make a brief analysis of its structure and to put into evidence the importance of this book for the Romanian laboratory medicine, some techniques (e.g. microscopic techniques) keeping their validity until today. The authors made over 800 detailed presentations about: laboratory sampling and preservation techniques, different types of tests and methods for qualitative and quantitative determinations, techniques to prepare various solutions, microbiological culture media, laboratory stains and reagents, as well as maneuvering of some laboratory equipments. For each method, Manta and Ciplea presented: the principle of working method, reagents required, the working technique, mode of calculation, the result and its interpretation. It also includes some laboratory apparatus descriptions, as well as their mode of working. With regard to the scientific value and to the practical utility of this book, it remains a very important milestone in the Romanian medical literature of the XX-th century.

Additive manufacturing capabilities applied to inertial confinement confusion at Los Alamos National Laboratory

DOE PAGES

Cardenas, Tana; Schmidt, Derek William; Peterson, Dominic S.

2016-08-01

We describe the use at Los Alamos National Laboratory of additive manufacturing (AM) for a variety of jigs and coating, assembly, and radiography fixtures. Additive manufacturing has also been used to produce shipping containers of complex design that would be too costly to have fabricated using traditional techniques. The current goal for AM use in target fabrication is to increase target accuracy and rigidity. This has been realized by implementing AM into target stalk fabrication, allowing increased complexity to address target strength and the addition of features for alignment at facilities. As a result, we will describe the fabrication ofmore » these components and our plans to utilize AM in the future.« less

Lessons learned from implementing a wet laboratory molecular training workshop for beach water quality monitoring.

PubMed

Verhougstraete, Marc Paul; Brothers, Sydney; Litaker, Wayne; Blackwood, A Denene; Noble, Rachel

2015-01-01

Rapid molecular testing methods are poised to replace many of the conventional, culture-based tests currently used in fields such as water quality and food science. Rapid qPCR methods have the benefit of being faster than conventional methods and provide a means to more accurately protect public health. However, many scientists and technicians in water and food quality microbiology laboratories have limited experience using these molecular tests. To ensure that practitioners can use and implement qPCR techniques successfully, we developed a week long workshop to provide hands-on training and exposure to rapid molecular methods for water quality management. This workshop trained academic professors, government employees, private industry representatives, and graduate students in rapid qPCR methods for monitoring recreational water quality. Attendees were immersed in these new methods with hands-on laboratory sessions, lectures, and one-on-one training. Upon completion, the attendees gained sufficient knowledge and practice to teach and share these new molecular techniques with colleagues at their respective laboratories. Key findings from this workshop demonstrated: 1) participants with no prior experience could be effectively trained to conduct highly repeatable qPCR analysis in one week; 2) participants with different desirable outcomes required exposure to a range of different platforms and sample processing approaches; and 3) the collaborative interaction amongst newly trained practitioners, workshop leaders, and members of the water quality community helped foster a cohesive cohort of individuals which can advocate powerful cohort for proper implementation of molecular methods.

Lessons Learned from Implementing a Wet Laboratory Molecular Training Workshop for Beach Water Quality Monitoring

PubMed Central

Verhougstraete, Marc Paul; Brothers, Sydney; Litaker, Wayne; Blackwood, A. Denene; Noble, Rachel

2015-01-01

Rapid molecular testing methods are poised to replace many of the conventional, culture-based tests currently used in fields such as water quality and food science. Rapid qPCR methods have the benefit of being faster than conventional methods and provide a means to more accurately protect public health. However, many scientists and technicians in water and food quality microbiology laboratories have limited experience using these molecular tests. To ensure that practitioners can use and implement qPCR techniques successfully, we developed a week long workshop to provide hands-on training and exposure to rapid molecular methods for water quality management. This workshop trained academic professors, government employees, private industry representatives, and graduate students in rapid qPCR methods for monitoring recreational water quality. Attendees were immersed in these new methods with hands-on laboratory sessions, lectures, and one-on-one training. Upon completion, the attendees gained sufficient knowledge and practice to teach and share these new molecular techniques with colleagues at their respective laboratories. Key findings from this workshop demonstrated: 1) participants with no prior experience could be effectively trained to conduct highly repeatable qPCR analysis in one week; 2) participants with different desirable outcomes required exposure to a range of different platforms and sample processing approaches; and 3) the collaborative interaction amongst newly trained practitioners, workshop leaders, and members of the water quality community helped foster a cohesive cohort of individuals which can advocate powerful cohort for proper implementation of molecular methods. PMID:25822486

NanoDesign: Concepts and Software for a Nanotechnology Based on Functionalized Fullerenes

NASA Technical Reports Server (NTRS)

Globus, Al; Jaffe, Richard; Chancellor, Marisa K. (Technical Monitor)

1996-01-01

Eric Drexler has proposed a hypothetical nanotechnology based on diamond and investigated the properties of such molecular systems. While attractive, diamonoid nanotechnology is not physically accessible with straightforward extensions of current laboratory techniques. We propose a nanotechnology based on functionalized fullerenes and investigate carbon nanotube based gears with teeth added via a benzyne reaction known to occur with C60. The gears are single-walled carbon nanotubes with appended coenzyme groups for teeth. Fullerenes are in widespread laboratory use and can be functionalized in many ways. Companion papers computationally demonstrate the properties of these gears (they appear to work) and the accessibility of the benzyne/nanotube reaction. This paper describes the molecular design techniques and rationale as well as the software that implements these design techniques. The software is a set of persistent C++ objects controlled by TCL command scripts. The c++/tcl interface is automatically generated by a software system called tcl_c++ developed by the author and described here. The objects keep track of different portions of the molecular machinery to allow different simulation techniques and boundary conditions to be applied as appropriate. This capability has been required to demonstrate (computationally) our gear's feasibility. A new distributed software architecture featuring a WWW universal client, CORBA distributed objects, and agent software is under consideration. The software architecture is intended to eventually enable a widely disbursed group to develop complex simulated molecular machines.

The measurement of ultrafine particles: A pilot study using a portable particle counting technique to measure generated particles during a micromachining process

NASA Astrophysics Data System (ADS)

Handy, Rodney G.; Jackson, Mark J.; Robinson, Grant M.; Lafreniere, Michael D.

2006-04-01

The accurate measurement of airborne particles in the nanometer range is a challenging task. Because several studies have linked exposures to airborne ultrafine particles to elevated human health risks, the need to assess the concentrations of particles in the workplace that are below 100 nm in diameter is imperative. Several different techniques for monitoring nanoparticles are now available, and others are currently being tested for their merit. Laboratory condensation particle counters (CPC), field-portable CPC, nanometer differential mobility analyzers, electron microscopy, and other novel and experimental approaches to measuring nanoparticles have been recently used in investigations. The first part of this article gives an overview of these techniques, and provides the advantages and disadvantages for each. The second part of this article introduces a portable technique, coupling two particle measurement devices that are capable of characterizing microscale and nanoscale particles in the field environment. Specifically, this pilot study involved the use of a direct-reading CPC and a laser particle counter to measure airborne concentrations of ultrafine particles during a laboratory machining process. The measurements were evaluated in real time, and subsequently, decisions regarding human exposure could be made in an efficient and effective manner. Along with the results from this study, further research efforts in related areas are discussed.

Shock-Ramp Loading of Tin and Aluminum

NASA Astrophysics Data System (ADS)

Seagle, Christopher; Davis, Jean; Martin, Matthew; Hanshaw, Heath

2013-06-01

Equation of state properties for materials off the principle Hugoniot and isentrope are currently poorly constrained. The ability to directly probe regions of phase space between the Hugoniot and isentrope under dynamic loading will greatly improve our ability to constrain equation of state properties under a variety of conditions and study otherwise inaccessible phase transitions. We have developed a technique at Sandia's Z accelerator to send a steady shock wave through a material under test, and subsequently ramp compress from the Hugoniot state. The shock-ramp experimental platform results in a unique loading path and enables probing of equation of state properties in regions of phase space otherwise difficult to access in dynamic experiments. A two-point minimization technique has been developed for the analysis of shock-ramp velocity data. The technique correctly accounts for the ``initial'' Hugoniot density of the material under test before the ramp wave arrives. Elevated quasi-isentropes have been measured for solid aluminum up to 1.4 Mbar and liquid tin up to 1.1 Mbar using the shock ramp technique. These experiments and the analysis of the resulting velocity profiles will be discussed. Sandia National Laboratories is a multi-program laboratory operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85.

Dense Gravity Currents with Breaking Internal Waves

NASA Astrophysics Data System (ADS)

Tanimoto, Yukinobu; Hogg, Charlie; Ouellette, Nicholas; Koseff, Jeffrey

2017-11-01

Shoaling and breaking internal waves along a pycnocline may lead to mixing and dilution of dense gravity currents, such as cold river inflows into lakes or brine effluent from desalination plants in near-coastal environments. In order to explore the interaction between gravity currents and breaking interfacial waves a series of laboratory experiments was performed in which a sequence of internal waves impinge upon a shelf-slope gravity current. The waves are generated in a two-layer thin-interface ambient water column under a variety of conditions characterizing both the waves and the gravity currents. The mixing of the gravity current is measured through both intrusive (CTD probe) and nonintrusive (Planar-laser inducted fluorescence) techniques. We will present results over a full range of Froude number (characterizing the waves) and Richardson number (characterizing the gravity current) conditions, and will discuss the mechanisms by which the gravity current is mixed into the ambient environment including the role of turbulence in the process. National Science Foundation.

Circular dichroism spectroscopy: Enhancing a traditional undergraduate biochemistry laboratory experience.

PubMed

Lewis, Russell L; Seal, Erin L; Lorts, Aimee R; Stewart, Amanda L

2017-11-01

The undergraduate biochemistry laboratory curriculum is designed to provide students with experience in protein isolation and purification protocols as well as various data analysis techniques, which enhance the biochemistry lecture course and give students a broad range of tools upon which to build in graduate level laboratories or once they begin their careers. One of the most common biochemistry protein purification experiments is the isolation and characterization of cytochrome c. Students across the country purify cytochrome c, lysozyme, or some other well-known protein to learn these common purification techniques. What this series of experiments lacks is the use of sophisticated instrumentation that is rarely available to undergraduate students. To give students a broader background in biochemical spectroscopy techniques, a new circular dichroism (CD) laboratory experiment was introduced into the biochemistry laboratory curriculum. This CD experiment provides students with a means of conceptualizing the secondary structure of their purified protein, and assessments indicate that students' understanding of the technique increased significantly. Students conducted this experiment with ease and in a short time frame, so this laboratory is conducive to merging with other data analysis techniques within a single laboratory period. © 2017 by The International Union of Biochemistry and Molecular Biology, 45(6):515-520, 2017. © 2017 The International Union of Biochemistry and Molecular Biology.

Laboratory techniques in plant molecular biology taught with UniformMu insertion alleles of maize

USDA-ARS?s Scientific Manuscript database

An undergraduate course - Laboratory Techniques in Plant Molecular Biology - was organized around our research application of UniformMu insertion alleles to investigate mitochondrial functions in plant reproduction. The course objectives were to develop students’ laboratory, record keeping, bioinfor...

Advancing crime scene computer forensics techniques

NASA Astrophysics Data System (ADS)

Hosmer, Chet; Feldman, John; Giordano, Joe

1999-02-01

Computers and network technology have become inexpensive and powerful tools that can be applied to a wide range of criminal activity. Computers have changed the world's view of evidence because computers are used more and more as tools in committing `traditional crimes' such as embezzlements, thefts, extortion and murder. This paper will focus on reviewing the current state-of-the-art of the data recovery and evidence construction tools used in both the field and laboratory for prosection purposes.

Root canal treatment and general health: a review of the literature.

PubMed

Murray, C A; Saunders, W P

2000-01-01

The focal infection theory was prominent in the medical literature during the early 1900s and curtailed the progress of endodontics. This theory proposed that microorganisms, or their toxins, arising from a focus of circumscribed infection within a tissue could disseminate systemically, resulting in the initiation or exacerbation of systemic illness or the damage of a distant tissue site. For example, during the focal infection era rheumatoid arthritis (RA) was identified as having a close relationship with dental health. The theory was eventually discredited because there was only anecdotal evidence to support its claims and few scientifically controlled studies. There has been a renewed interest in the influence that foci of infection within the oral tissues may have on general health. Some current research suggests a possible relationship between dental health and cardiovascular disease and published case reports have cited dental sources as causes for several systemic illnesses. Improved laboratory procedures employing sophisticated molecular biological techniques and enhanced culturing techniques have allowed researchers to confirm that bacteria recovered from the peripheral blood during root canal treatment originated in the root canal. It has been suggested that the bacteraemia, or the associated bacterial endotoxins, subsequent to root canal treatment, may cause potential systemic complications. Further research is required, however, using current sampling and laboratory methods from scientifically controlled population groups to determine if a significant relationship between general health and periradicular infection exists.

Technical Design Report for the FACET-II Project at SLAC National Accelerator Laboratory

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

None, None

Electrons can “surf” on waves of plasma – a hot gas of charged particles – gaining very high energies in very short distances. This approach, called plasma wakefield acceleration, has the potential to dramatically shrink the size and cost of particle accelerators. Research at the SLAC National Accelerator Laboratory has demonstrated that plasmas can provide 1,000 times the acceleration in a given distance compared with current technologies. Developing revolutionary and more efficient acceleration techniques that allow for an affordable high-energy collider has been the focus of FACET, a National User Facility at SLAC. FACET used part of SLAC’s two-mile-long linearmore » accelerator to generate high-density beams of electrons and their antimatter counterparts, positrons. Research into plasma wakefield acceleration was the primary motivation for constructing FACET. In April 2016, FACET operations came to an end to make way for the second phase of SLAC’s x-ray laser, the LCLS-II, which will use part of the tunnel occupied by FACET. FACET-II is a new test facility to provide the unique capability to develop advanced acceleration and coherent radiation techniques with high-energy electron and positron beams. FACET-II represents a major upgrade over current FACET capabilities and the breadth of the potential research program makes it truly unique.« less

Development of Real Time Implementation of 5/5 Rule based Fuzzy Logic Controller Shunt Active Power Filter for Power Quality Improvement

NASA Astrophysics Data System (ADS)

Puhan, Pratap Sekhar; Ray, Pravat Kumar; Panda, Gayadhar

2016-12-01

This paper presents the effectiveness of 5/5 Fuzzy rule implementation in Fuzzy Logic Controller conjunction with indirect control technique to enhance the power quality in single phase system, An indirect current controller in conjunction with Fuzzy Logic Controller is applied to the proposed shunt active power filter to estimate the peak reference current and capacitor voltage. Current Controller based pulse width modulation (CCPWM) is used to generate the switching signals of voltage source inverter. Various simulation results are presented to verify the good behaviour of the Shunt active Power Filter (SAPF) with proposed two levels Hysteresis Current Controller (HCC). For verification of Shunt Active Power Filter in real time, the proposed control algorithm has been implemented in laboratory developed setup in dSPACE platform.

Enabling cost-effective high-current burst-mode operation in superconducting accelerators

DOE PAGES

Sheffield, Richard L.

2015-06-01

Superconducting (SC) accelerators are very efficient for CW or long-pulse operation, and normal conducting (NC) accelerators are cost effective for short-pulse operation. The addition of a short NC linac section to a SC linac can correct for the energy droop that occurs when pulsed high-current operation is required that exceeds the capability of the klystrons to replenish the cavity RF fields due to the long field fill-times of SC structures, or a requirement to support a broad range of beam currents results in variable beam loading. This paper describes the implementation of this technique to enable microseconds of high beam-current,more » 90 mA or more, in a 12 GeV SC long-pulse accelerator designed for the MaRIE 42-keV XFEL proposed for Los Alamos National Laboratory.« less

Corrosion Assessment of Steel Bars Used in Reinforced Concrete Structures by Means of Eddy Current Testing

PubMed Central

de Alcantara, Naasson P.; da Silva, Felipe M.; Guimarães, Mateus T.; Pereira, Matheus D.

2015-01-01

This paper presents a theoretical and experimental study on the use of Eddy Current Testing (ECT) to evaluate corrosion processes in steel bars used in reinforced concrete structures. The paper presents the mathematical basis of the ECT sensor built by the authors; followed by a finite element analysis. The results obtained in the simulations are compared with those obtained in experimental tests performed by the authors. Effective resistances and inductances; voltage drops and phase angles of wound coil are calculated using both; simulated and experimental data; and demonstrate a strong correlation. The production of samples of corroded steel bars; by using an impressed current technique is also presented. The authors performed experimental tests in the laboratory using handmade sensors; and the corroded samples. In the tests four gauges; with five levels of loss-of-mass references for each one were used. The results are analyzed in the light of the loss-of-mass and show a strong linear behavior for the analyzed parameters. The conclusions emphasize the feasibility of the proposed technique and highlight opportunities for future works. PMID:26712754

Corrosion Assessment of Steel Bars Used in Reinforced Concrete Structures by Means of Eddy Current Testing.

PubMed

de Alcantara, Naasson P; da Silva, Felipe M; Guimarães, Mateus T; Pereira, Matheus D

2015-12-24

This paper presents a theoretical and experimental study on the use of Eddy Current Testing (ECT) to evaluate corrosion processes in steel bars used in reinforced concrete structures. The paper presents the mathematical basis of the ECT sensor built by the authors; followed by a finite element analysis. The results obtained in the simulations are compared with those obtained in experimental tests performed by the authors. Effective resistances and inductances; voltage drops and phase angles of wound coil are calculated using both; simulated and experimental data; and demonstrate a strong correlation. The production of samples of corroded steel bars; by using an impressed current technique is also presented. The authors performed experimental tests in the laboratory using handmade sensors; and the corroded samples. In the tests four gauges; with five levels of loss-of-mass references for each one were used. The results are analyzed in the light of the loss-of-mass and show a strong linear behavior for the analyzed parameters. The conclusions emphasize the feasibility of the proposed technique and highlight opportunities for future works.

Nano-Al Based Energetics: Rapid Heating Studies and a New Preparation Technique

NASA Astrophysics Data System (ADS)

Sullivan, Kyle; Kuntz, Josh; Gash, Alex; Zachariah, Michael

2011-06-01

Nano-Al based thermites have become an attractive alternative to traditional energetic formulations due to their increased energy density and high reactivity. Understanding the intrinsic reaction mechanism has been a difficult task, largely due to the lack of experimental techniques capable of rapidly and uniform heating a sample (~104- 108 K/s). The current work presents several studies on nano-Al based thermites, using rapid heating techniques. A new mechanism termed a Reactive Sintering Mechanism is proposed for nano-Al based thermites. In addition, new experimental techniques for nanocomposite thermite deposition onto thin Pt electrodes will be discussed. This combined technique will offer more precise control of the deposition, and will serve to further our understanding of the intrinsic reaction mechanism of rapidly heated energetic systems. An improved mechanistic understanding will lead to the development of optimized formulations and architectures. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

Various extraction and analytical techniques for isolation and identification of secondary metabolites from Nigella sativa seeds.

PubMed

Liu, X; Abd El-Aty, A M; Shim, J-H

2011-10-01

Nigella sativa L. (black cumin), commonly known as black seed, is a member of the Ranunculaceae family. This seed is used as a natural remedy in many Middle Eastern and Far Eastern countries. Extracts prepared from N. sativa have, for centuries, been used for medical purposes. Thus far, the organic compounds in N. sativa, including alkaloids, steroids, carbohydrates, flavonoids, fatty acids, etc. have been fairly well characterized. Herein, we summarize some new extraction techniques, including microwave assisted extraction (MAE) and supercritical extraction techniques (SFE), in addition to the classical method of hydrodistillation (HD), which have been employed for isolation and various analytical techniques used for the identification of secondary metabolites in black seed. We believe that some compounds contained in N. sativa remain to be identified, and that high-throughput screening could help to identify new compounds. A study addressing environmentally-friendly techniques that have minimal or no environmental effects is currently underway in our laboratory.

ANITA (Advanced Network for Isotope and TArget laboratories) - The urgent need for a European target preparation network

NASA Astrophysics Data System (ADS)

Schumann, Dorothea; Sibbens, Goedele; Stolarz, Anna; Eberhardt, Klaus; Lommel, Bettina; Stodel, Christelle

2018-05-01

A wide number of research fields in the nuclear sector requires high-quality and well-characterized samples and targets. Currently, only a few laboratories own or have access to the equipment allowing fulfilling such demands. Coordination of activities and sharing resources is therefore mandatory to meet the increasing needs. This very urgent issue has now been addressed by six European target laboratories with an initiative called ANITA (Advanced Network for Isotope and TArget laboratories). The global aim of ANITA is to establish an overarching research infrastructure service for isotope and target production and develop a tight cooperation between the target laboratories in Europe in order to transfer the knowledge and improve the production techniques of well-characterized samples and targets. Moreover, the interaction of the target producers with the users shall be encouraged and intensified to deliver tailor-made targets best-suited to the envisaged experiments. For the realization of this ambitious goal, efforts within the European Commission and strong support by the target-using communities will be necessary. In particular, an appropriate funding instrument has to be found and applied, enabling ANITA to develop from an initiative employed by the interested parties to a real coordination platform.

Introduction of the Bethesda System to Mainland China with a Web-based tutorial.

PubMed

Yuan, Qin; Chang, Alexander Russell; Ng, Ho Keung

2003-01-01

To validate the use of a Web-based tutorial to introduce the Bethesda System (TBS) to Mainland Chinese laboratories. Digitized color images of the diagnostic features in 20 Pap smears were displayed on a Web page. Participants were asked to give each smear a diagnosis using the reporting nomenclature employed in their laboratory or one that was familiar to them. This was followed by teaching images of each smear accompanied by text in English and Chinese that highlighted important features for making a diagnosis using TBS. Participants then reviewed the 20 original Pap smears and rendered a diagnosis using TBS. Pathologists and cytotechnologists at 17 laboratories located in 10 cities completed the exercise. The average diagnostic accuracy for the 20 Pap smears before and after the tutorial was 76% and 88%, respectively. Web-based tutorials can be used for disseminating cytologic information to widely dispersed laboratories in China and help enhance the practice of cytology, currently an underutilized diagnostic technique. However, such difficulties as lack of Internet connections in the laboratory, outdated computers and a lack of interest in cytology need to be overcome to ensure success.

The Effect of Jigsaw Technique on the Students' Laboratory Material Recognition and Usage Skills in General Physics Laboratory-I Course

ERIC Educational Resources Information Center

Aydin, Abdullah; Biyikli, Filiz

2017-01-01

This research aims to compare the effects of Jigsaw technique from the cooperative learning methods and traditional learning method on laboratory material recognition and usage skills of students in General Physics Lab-I Course. This study was conducted with 63 students who took general physics laboratory-I course in the department of science…

A protocol for rat in vitro fertilization during conventional laboratory working hours.

PubMed

Aoto, Toshihiro; Takahashi, Ri-ichi; Ueda, Masatsugu

2011-12-01

In vitro fertilization (IVF) is a valuable technique for the propagation of experimental animals. IVF has typically been used in mice to rapidly expand breeding colonies and create large numbers of embryos. However, applications of IVF in rat breeding experiments have stalled due to the inconvenient laboratory work schedules imposed by current IVF protocols for this species. Here, we developed a new rat IVF protocol that consists of experimental steps performed during common laboratory working hours. Our protocol can be completed within 12 h by shortening the period of sperm capacitation from 5 to 1 h and the fertilization time from 10 to 8 h in human tubal fluid (HTF) medium. This new protocol generated an excellent birth rate and was applicable not only to closed colony rat strains, such as Wistar, Long-Evans, and Sprague-Dawley (SD), but also to the inbred Lewis strain. Moreover, Wistar and Long-Evans embryos prepared by this protocol were successfully frozen by vitrification and later successfully thawed and resuscitated. This protocol is practical and can be easily adopted by laboratory workers.

Reproducibility of telomere length assessment: an international collaborative study.

PubMed

Martin-Ruiz, Carmen M; Baird, Duncan; Roger, Laureline; Boukamp, Petra; Krunic, Damir; Cawthon, Richard; Dokter, Martin M; van der Harst, Pim; Bekaert, Sofie; de Meyer, Tim; Roos, Goran; Svenson, Ulrika; Codd, Veryan; Samani, Nilesh J; McGlynn, Liane; Shiels, Paul G; Pooley, Karen A; Dunning, Alison M; Cooper, Rachel; Wong, Andrew; Kingston, Andrew; von Zglinicki, Thomas

2015-10-01

Telomere length is a putative biomarker of ageing, morbidity and mortality. Its application is hampered by lack of widely applicable reference ranges and uncertainty regarding the present limits of measurement reproducibility within and between laboratories. We instigated an international collaborative study of telomere length assessment: 10 different laboratories, employing 3 different techniques [Southern blotting, single telomere length analysis (STELA) and real-time quantitative PCR (qPCR)] performed two rounds of fully blinded measurements on 10 human DNA samples per round to enable unbiased assessment of intra- and inter-batch variation between laboratories and techniques. Absolute results from different laboratories differed widely and could thus not be compared directly, but rankings of relative telomere lengths were highly correlated (correlation coefficients of 0.63-0.99). Intra-technique correlations were similar for Southern blotting and qPCR and were stronger than inter-technique ones. However, inter-laboratory coefficients of variation (CVs) averaged about 10% for Southern blotting and STELA and more than 20% for qPCR. This difference was compensated for by a higher dynamic range for the qPCR method as shown by equal variance after z-scoring. Technical variation per laboratory, measured as median of intra- and inter-batch CVs, ranged from 1.4% to 9.5%, with differences between laboratories only marginally significant (P = 0.06). Gel-based and PCR-based techniques were not different in accuracy. Intra- and inter-laboratory technical variation severely limits the usefulness of data pooling and excludes sharing of reference ranges between laboratories. We propose to establish a common set of physical telomere length standards to improve comparability of telomere length estimates between laboratories. © The Author 2014. Published by Oxford University Press on behalf of the International Epidemiological Association.

A systems biology perspective of wine fermentations.

PubMed

Pizarro, Francisco; Vargas, Felipe A; Agosin, Eduardo

2007-11-01

The yeast Saccharomyces cerevisiae is an important industrial microorganism. Nowadays, it is being used as a cell factory for the production of pharmaceuticals such as insulin, although this yeast has long been utilized in the bakery to raise dough, and in the production of alcoholic beverages, fermenting the sugars derived from rice, wheat, barley, corn and grape juice. S. cerevisiae has also been extensively used as a model eukaryotic system. In the last decade, genomic techniques have revealed important features of its molecular biology. For example, DNA array technologies are routinely used for determining gene expression levels in cells under different physiological conditions or environmental stimuli. Laboratory strains of S. cerevisiae are different from wine strains. For instance, laboratory yeasts are unable to completely transform all the sugar in the grape must into ethanol under winemaking conditions. In fact, standard culture conditions are usually very different from winemaking conditions, where multiple stresses occur simultaneously and sequentially throughout the fermentation. The response of wine yeasts to these stimuli differs in some aspects from laboratory strains, as suggested by the increasing number of studies in functional genomics being conducted on wine strains. In this paper we review the most recent applications of post-genomic techniques to understand yeast physiology in the wine industry. We also report recent advances in wine yeast strain improvement and propose a reference framework for integration of genomic information, bioinformatic tools and molecular biology techniques for cellular and metabolic engineering. Finally, we discuss the current state and future perspectives for using 'modern' biotechnology in the wine industry.

LISA Technology Development at GSFC

NASA Technical Reports Server (NTRS)

Thorpe, James Ira; McWilliams, S.; Baker, J.

2008-01-01

The prime focus of LISA technology development efforts at NASA/GSFC has been in LISA interferometry, specifically in the area of laser frequency noise mitigation. Laser frequency noise is addressed through a combination of stabilization and common-mode rejection. Current plans call for two stages of stabilization, pre-stabilization to a local frequency reference and further stabilization using the constellation as a frequency reference. In order for these techniques to be used simultaneously, the pre-stabilization step must provide an adjustable frequency offset. Here, we report on a modification to the standard modulation/demodulation techniques used to stabilize to optical cavities that generates a frequency-tunable reference from a fixed-length cavity. This technique requires no modifications to the cavity itself and only minor modifications to the components. The measured noise performance and dynamic range of the laboratory prototype meets the LISA requirements.

Workstations and gloveboxes for space station

NASA Technical Reports Server (NTRS)

Junge, Maria

1990-01-01

Lockheed Missiles and Space Company is responsible for designing, developing, and building the Life Sciences Glovebox, the Laboratory Sciences Workbench, and the Maintenance Workstation plus 16 other pieces of equipment for the U.S. Laboratory Module of the Space Station Freedom. The Laboratory Sciences Workbench and the Maintenance Workstation were functionally combined into a double structure to save weight and volume which are important commodities on the Space Station Freedom. The total volume of these items is approximately 180 cubic feet. These workstations and the glovebox will be delivered to NASA in 1994 and will be launched in 1995. The very long lifetime of 30 years presents numerous technical challenges in the areas of design and reliability. The equipment must be easy to use by international crew members and also easy to maintain on-orbit. For example, seals must be capable of on-orbit changeout and reverification. The stringent contamination requirements established for Space Station Freedom equipment also complicate the zero gravity glovebox design. The current contamination control system for the Life Sciences Glovebox and the Maintenance Workstation is presented. The requirement for the Life Sciences Glovebox to safely contain toxic, reactive, and radioactive materials presents challenges. Trade studies, CAD simulation techniques and design challenges are discussed to illustrate the current baseline conceptual designs. Areas which need input from the user community are identified.

Investigation of the Degradation Mechanisms of a Variety of Organic Photovoltaic Devices by Combination of Imaging Techniques - The ISOS-3 Inter-Laboratory Collaboration

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

Rosch, R.; Tanenbaum, D. M.; Jrgensen, M.

2012-04-01

The investigation of degradation of seven distinct sets (with a number of individual cells of n {>=} 12) of state of the art organic photovoltaic devices prepared by leading research laboratories with a combination of imaging methods is reported. All devices have been shipped to and degraded at Riso DTU up to 1830 hours in accordance with established ISOS-3 protocols under defined illumination conditions. Imaging of device function at different stages of degradation was performed by laser-beam induced current (LBIC) scanning; luminescence imaging, specifically photoluminescence (PLI) and electroluminescence (ELI); as well as by lock-in thermography (LIT). Each of the imagingmore » techniques exhibits its specific advantages with respect to sensing certain degradation features, which will be compared and discussed here in detail. As a consequence, a combination of several imaging techniques yields very conclusive information about the degradation processes controlling device function. The large variety of device architectures in turn enables valuable progress in the proper interpretation of imaging results -- hence revealing the benefits of this large scale cooperation in making a step forward in the understanding of organic solar cell aging and its interpretation by state-of-the-art imaging methods.« less

Army medical laboratory telemedicine: role of mass spectrometry in telediagnosis for chemical and biological defense.

PubMed

Smith, J R; Shih, M L; Price, E O; Platoff, G E; Schlager, J J

2001-12-01

An army medical field laboratory presently has the capability of performing standard protocols developed at the US Army Medical Research Institute of Chemical Defense for verification of nerve agent or sulfur mustard exposure. The protocols analyze hydrolysis products of chemical warfare agents using gas chromatography/mass spectrometry. Additionally, chemical warfare agents can produce alkylated or phosphorylated proteins following human exposure that have long biological half-lives and can be used as diagnostic biomarkers of chemical agent exposure. An analytical technique known as matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF/MS) currently is being examined for its potential to analyze these biomarkers. The technique is capable of detecting large biomolecules and modifications made to them. Its fast analysis time makes MALDI-TOF/MS technology suitable for screening casualties from chemical or biological attacks. Basic operation requires minimal training and the instrument has the potential to become field-portable. The limitation of the technique is that the generated data may require considerable expertise from knowledgeable personnel for consultation to ensure correct interpretation. The interaction between research scientists and field personnel in the acquisition of data and its interpretation via advanced digital telecommunication technologies can enhance rapid diagnosis and subsequently improve patient care in remote areas. Copyright 2001 John Wiley & Sons, Ltd.

Coordinate Measuring Machine Pit Artifact Inspection Procedure

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

Montano, Joshua D.

2012-07-31

The goal of this document is to outline a procedure for dimensional measurement of Los Alamos National Laboratory's CMM Pit Artifact. This procedure will be used by the Manufacturing Practice's Inspection Technology Subgroup of the Interagency Manufacturing Operations Group and Joint Operations Weapon Operations Group (IMOG/JOWOG 39) round robin participants. The intent is to assess the state of industry within the Nuclear Weapons Complex for measurements made on this type of part and find which current measurement strategies and techniques produce the best results.

Reconstruction of multiple cracks from experimental electrostatic boundary measurements

NASA Technical Reports Server (NTRS)

Bryan, Kurt; Liepa, Valdis; Vogelius, Michael

1993-01-01

An algorithm for recovering a collection of linear cracks in a homogeneous electrical conductor from boundary measurements of voltages induced by specified current fluxes is described. The technique is a variation of Newton's method and is based on taking weighted averages of the boundary data. An apparatus that was constructed specifically for generating laboratory data on which to test the algorithm is also described. The algorithm is applied to a number of different test cases and the results are discussed.

Developments in Decontamination Technologies of Military Personnel and Equipment

NASA Astrophysics Data System (ADS)

Sata, Utkarsh R.; Ramkumar, Seshadri S.

Individual protection is important for warfighters, first responders and civilians to meet the current threat of toxic chemicals and chemical warfare (CW) agents. Within the realm of individual protection, decontamination of warfare agents is not only required on the battlefield but also in laboratory, pilot plants, production and agent destruction sites. It is of high importance to evaluate various decontaminants and decontamination techniques for implementing the best practices in varying scenarios such as decontamination of personnel, sites and sensitive equipment.

Fatigue Test Design: Scenarios for Biaxial Fatigue Testing of a 60-Meter Wind Turbine Blade

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

Post, Nathan

Current practice in commercial certification of wind turbine blades is to perform separate flap and lead-lag fatigue tests. The National Renewable Energy Laboratory has been researching and evaluating biaxial fatigue testing techniques and demonstrating various options, typically on smaller-scale test articles at the National Wind Technology Center. This report evaluates some of these biaxial fatigue options in the context of application to a multimegawatt blade certification test program at the Wind Technology Testing Center in Charlestown, Massachusetts.

Cryogenic testing of Planck sorption cooler test facility

NASA Technical Reports Server (NTRS)

Zhang, B.; Pearson, D.; Borders, J.; Franklin, B.; Prina, M.; Hardy, J.; Crumb, D.

2004-01-01

A test facility has been upgraded in preparation for testing of two hydrogen sorption cryocoolers operating at 18/20 K. these sorption coolers are currently under development at the Jet Propulsion Laboratory. This work summarizes the scope of the test facility upgrade, including design for cryogenic cooling power delivery, system thermal management, insulation schemes, and data acquisition techniques. Ground support equipment for the sorption coolers, structural features of the test chamber, and the vacuum system involved for system testing will also be described in detail.

Superconducting thin-film gyroscope readout for Gravity Probe-B

NASA Technical Reports Server (NTRS)

Lockhart, James M.; Cheung, W. Stephen; Gill, Dale K.

1987-01-01

The high-resolution gyroscope readout system for the Stanford Gravity Probe-B experiment, whose purpose is to measure two general relativistic precessions of gyroscopes in earth orbit, is described. In order to achieve the required resolution in angle (0.001 arcsec), the readout system combines high-precision mechanical fabrication and measurement techniques with superconducting thin-film technology, ultralow magnetic fields, and SQUID detectors. The system design, performance limits achievable with current technology, and the results of fabrication and laboratory testing to date are discussed.

Quantitative Determination of Caffeine in Beverages Using a Combined SPME-GC/MS Method

NASA Astrophysics Data System (ADS)

Pawliszyn, Janusz; Yang, Min J.; Orton, Maureen L.

1997-09-01

Solid-phase microextraction (SPME) combined with gas chromatography/mass spectrometry (GC/MS) has been applied to the analysis of various caffeinated beverages. Unlike the current methods, this technique is solvent free and requires no pH adjustments. The simplicity of the SPME-GC/MS method lends itself to a good undergraduate laboratory practice. This publication describes the analytical conditions and presents the data for determination of caffeine in coffee, tea, and coke. Quantitation by isotopic dilution is also illustrated.

Analysis of body fluids for forensic purposes: from laboratory testing to non-destructive rapid confirmatory identification at a crime scene.

PubMed

Virkler, Kelly; Lednev, Igor K

2009-07-01

Body fluid traces recovered at crime scenes are among the most important types of evidence to forensic investigators. They contain valuable DNA evidence which can identify a suspect or victim as well as exonerate an innocent individual. The first step of identifying a particular body fluid is highly important since the nature of the fluid is itself very informative to the investigation, and the destructive nature of a screening test must be considered when only a small amount of material is available. The ability to characterize an unknown stain at the scene of the crime without having to wait for results from a laboratory is another very critical step in the development of forensic body fluid analysis. Driven by the importance for forensic applications, body fluid identification methods have been extensively developed in recent years. The systematic analysis of these new developments is vital for forensic investigators to be continuously educated on possible superior techniques. Significant advances in laser technology and the development of novel light detectors have dramatically improved spectroscopic methods for molecular characterization over the last decade. The application of this novel biospectroscopy for forensic purposes opens new and exciting opportunities for the development of on-field, non-destructive, confirmatory methods for body fluid identification at a crime scene. In addition, the biospectroscopy methods are universally applicable to all body fluids unlike the majority of current techniques which are valid for individual fluids only. This article analyzes the current methods being used to identify body fluid stains including blood, semen, saliva, vaginal fluid, urine, and sweat, and also focuses on new techniques that have been developed in the last 5-6 years. In addition, the potential of new biospectroscopic techniques based on Raman and fluorescence spectroscopy is evaluated for rapid, confirmatory, non-destructive identification of a body fluid at a crime scene.

Histological Stains: A Literature Review and Case Study

PubMed Central

Alturkistani, Hani A; Tashkandi, Faris M; Mohammedsaleh, Zuhair M

2016-01-01

The history of histology indicates that there have been significant changes in the techniques used for histological staining through chemical, molecular biology assays and immunological techniques, collectively referred to as histochemistry. Early histologists used the readily available chemicals to prepare tissues for microscopic studies; these laboratory chemicals were potassium dichromate, alcohol and the mercuric chloride to harden cellular tissues. Staining techniques used were carmine, silver nitrate, Giemsa, Trichrome Stains, Gram Stain and Hematoxylin among others. The purpose of this research was to assess past and current literature reviews, as well as case studies, with the aim of informing ways in which histological stains have been improved in the modern age. Results from the literature review has indicated that there has been an improvement in histopathology and histotechnology in stains used. There has been a rising need for efficient, accurate and less complex staining procedures. Many stain procedures are still in use today, and many others have been replaced with new immunostaining, molecular, non-culture and other advanced staining techniques. Some staining methods have been abandoned because the chemicals required have been medically proven to be toxic. The case studies indicated that in modern histology a combination of different stain techniques are used to enhance the effectiveness of the staining process. Currently, improved histological stains, have been modified and combined with other stains to improve their effectiveness. PMID:26493433

Histological Stains: A Literature Review and Case Study.

PubMed

Alturkistani, Hani A; Tashkandi, Faris M; Mohammedsaleh, Zuhair M

2015-06-25

The history of histology indicates that there have been significant changes in the techniques used for histological staining through chemical, molecular biology assays and immunological techniques, collectively referred to as histochemistry. Early histologists used the readily available chemicals to prepare tissues for microscopic studies; these laboratory chemicals were potassium dichromate, alcohol and the mercuric chloride to harden cellular tissues. Staining techniques used were carmine, silver nitrate, Giemsa, Trichrome Stains, Gram Stain and Hematoxylin among others. The purpose of this research was to assess past and current literature reviews, as well as case studies, with the aim of informing ways in which histological stains have been improved in the modern age. Results from the literature review has indicated that there has been an improvement in histopathology and histotechnology in stains used. There has been a rising need for efficient, accurate and less complex staining procedures. Many stain procedures are still in use today, and many others have been replaced with new immunostaining, molecular, non-culture and other advanced staining techniques. Some staining methods have been abandoned because the chemicals required have been medically proven to be toxic. The case studies indicated that in modern histology a combination of different stain techniques are used to enhance the effectiveness of the staining process. Currently, improved histological stains, have been modified and combined with other stains to improve their effectiveness.

Simple and Rapid System for Two-Dimensional Gel Electrophoresis Technique: A Laboratory Exercise for High School Students

ERIC Educational Resources Information Center

Maurye, Praveen; Basu, Arpita; Biswas, Jayanta Kumar; Bandyopadhyay, Tapas Kumar; Naskar, Malay

2018-01-01

Polyacrylamide gel electrophoresis (PAGE) is the most classical technique favored worldwide for resolution of macromolecules in many biochemistry laboratories due to its incessant advanced developments and wide modifications. These ever-growing advancements in the basic laboratory equipments lead to emergence of many expensive, complex, and tricky…

A Semester-Long Project-Oriented Biochemistry Laboratory Based on "Helicobacter pylori" Urease

ERIC Educational Resources Information Center

Farnham, Kate R.; Dube, Danielle H.

2015-01-01

Here we present the development of a 13 week project-oriented biochemistry laboratory designed to introduce students to foundational biochemical techniques and then enable students to perform original research projects once they have mastered these techniques. In particular, we describe a semester-long laboratory that focuses on a biomedically…

Do-It-Yourself Experiments for the Instructional Laboratory

ERIC Educational Resources Information Center

Craig, Norman C.; Hill, Cortland S.

2012-01-01

A new design for experiments in the general chemistry laboratory incorporates a "do-it-yourself" component for students. In this design, students perform proven experiments to gain experience with techniques for about two-thirds of a laboratory session and then spend the last part in the do-it-yourself component, applying the techniques to an…

High-Precision Isotope Ratio Measurements of Sub-Picogram Actinide Samples

NASA Astrophysics Data System (ADS)

Pollington, A. D.; Kinman, W.

2016-12-01

One of the most exciting trends in analytical geochemistry over the past decade is the push towards smaller and smaller sample sizes while simultaneously achieving high precision isotope ratio measurements. This trend has been driven by advances in clean chemistry protocols, and by significant breakthroughs in mass spectrometer ionization efficiency and detector quality (stability and noise for low signals). In this presentation I will focus on new techniques currently being developed at Los Alamos National Laboratory for the characterization of ultra-small samples (pg, fg, ag), with particular focus on actinide measurements by MC-ICP-MS. Analyses of U, Pu, Th and Am are routinely carried out in our facility using multi-ion counting techniques. I will describe some of the challenges associated with using exclusively ion counting methods (e.g., stability, detector cross calibration, etc.), and how we work to mitigate them. While the focus of much of the work currently being carried out is in the broad field of nuclear forensics and safeguards, the techniques that are being developed are directly applicable to many geologic questions that require analyses of small samples of U and Th, for example. In addition to the description of the technique development, I will present case studies demonstrating the precision and accuracy of the method as applied to real-world samples.

The Development of Models for Carbon Dioxide Reduction Technologies for Spacecraft Air Revitalization

NASA Technical Reports Server (NTRS)

Swickrath, Michael J.; Anderson, Molly

2012-01-01

Through the respiration process, humans consume oxygen (O2) while producing carbon dioxide (CO2) and water (H2O) as byproducts. For long term space exploration, CO2 concentration in the atmosphere must be managed to prevent hypercapnia. Moreover, CO2 can be used as a source of oxygen through chemical reduction serving to minimize the amount of oxygen required at launch. Reduction can be achieved through a number of techniques. NASA is currently exploring the Sabatier reaction, the Bosch reaction, and co- electrolysis of CO2 and H2O for this process. Proof-of-concept experiments and prototype units for all three processes have proven capable of returning useful commodities for space exploration. All three techniques have demonstrated the capacity to reduce CO2 in the laboratory, yet there is interest in understanding how all three techniques would perform at a system level within a spacecraft. Consequently, there is an impetus to develop predictive models for these processes that can be readily rescaled and integrated into larger system models. Such analysis tools provide the ability to evaluate each technique on a comparable basis with respect to processing rates. This manuscript describes the current models for the carbon dioxide reduction processes under parallel developmental efforts. Comparison to experimental data is provided were available for verification purposes.

A new technique to control brushless motor for blood pump application.

PubMed

Fonseca, Jeison; Andrade, Aron; Nicolosi, Denys E C; Biscegli, José F; Legendre, Daniel; Bock, Eduardo; Lucchi, Júlio César

2008-04-01

This article presents a back-electromotive force (BEMF)-based technique of detection for sensorless brushless direct current motor (BLDCM) drivers. The BLDCM has been chosen as the energy converter in rotary or pulsatile blood pumps that use electrical motors for pumping. However, in order to operate properly, the BLDCM driver needs to know the shaft position. Usually, that information is obtained through a set of Hall sensors assembled close to the rotor and connected to the electronic controller by wires. Sometimes, a large distance between the motor and controller makes the system susceptible to interference on the sensor signal because of winding current switching. Thus, the goal of the sensorless technique presented in this study is to avoid this problem. First, the operation of BLDCM was evaluated on the electronic simulator PSpice. Then, a BEMF detector circuitry was assembled in our laboratories. For the tests, a sensor-dependent system was assembled where the direct comparison between the Hall sensors signals and the detected signals was performed. The obtained results showed that the output sensorless detector signals are very similar to the Hall signals at speeds of more than 2500 rpm. Therefore, the sensorless technique is recommended as a responsible or redundant system to be used in rotary blood pumps.

Linear Covariance Analysis For Proximity Operations Around Asteroid 2008 EV5

NASA Technical Reports Server (NTRS)

Wright, Cinnamon A.; Bhatt, Sagar; Woffinden, David; Strube, Matthew; D'Souza, Chris

2015-01-01

The NASA initiative to collect an asteroid, the Asteroid Robotic Redirect Mission (ARRM), is currently investigating the option of retrieving a boulder from an asteroid, demonstrating planetary defense with an enhanced gravity tractor technique, and returning it to a lunar orbit. Techniques for accomplishing this are being investigated by the Satellite Servicing Capabilities Office (SSCO) at NASA GSFC in collaboration with JPL, NASA JSC, LaRC, and Draper Laboratory, Inc. Two critical phases of the mission are the descent to the boulder and the Enhanced Gravity Tractor demonstration. A linear covariance analysis is done for these phases to assess the feasibility of these concepts with the proposed design of the sensor and actuator suite of the Asteroid Redirect Vehicle (ARV). The sensor suite for this analysis includes a wide field of view camera, LiDAR, and an IMU. The proposed asteroid of interest is currently the C-type asteroid 2008 EV5, a carbonaceous chondrite that is of high interest to the scientific community. This paper presents an overview of the linear covariance analysis techniques and simulation tool, provides sensor and actuator models, and addresses the feasibility of descending to the surface of the asteroid within allocated requirements as well as the possibility of maintaining a halo orbit to demonstrate the Enhanced Gravity Tractor technique.

An Introductory Undergraduate Course Covering Animal Cell Culture Techniques

ERIC Educational Resources Information Center

Mozdziak, Paul E.; Petitte, James N.; Carson, Susan D.

2004-01-01

Animal cell culture is a core laboratory technique in many molecular biology, developmental biology, and biotechnology laboratories. Cell culture is a relatively old technique that has been sparingly taught at the undergraduate level. The traditional methodology for acquiring cell culture training has been through trial and error, instruction when…

ICASE/LaRC Workshop on Adaptive Grid Methods

NASA Technical Reports Server (NTRS)

South, Jerry C., Jr. (Editor); Thomas, James L. (Editor); Vanrosendale, John (Editor)

1995-01-01

Solution-adaptive grid techniques are essential to the attainment of practical, user friendly, computational fluid dynamics (CFD) applications. In this three-day workshop, experts gathered together to describe state-of-the-art methods in solution-adaptive grid refinement, analysis, and implementation; to assess the current practice; and to discuss future needs and directions for research. This was accomplished through a series of invited and contributed papers. The workshop focused on a set of two-dimensional test cases designed by the organizers to aid in assessing the current state of development of adaptive grid technology. In addition, a panel of experts from universities, industry, and government research laboratories discussed their views of needs and future directions in this field.

Generation of Ramped Current Profiles in Relativistic Electron Beams Using Wakefields in Dielectric Structures

DOE PAGES

Andonian, G.; Barber, S.; O’Shea, F. H.; ...

2017-02-03

We show that temporal pulse tailoring of charged-particle beams is essential to optimize efficiency in collinear wakefield acceleration schemes. In this Letter, we demonstrate a novel phase space manipulation method that employs a beam wakefield interaction in a dielectric structure, followed by bunch compression in a permanent magnet chicane, to longitudinally tailor the pulse shape of an electron beam. This compact, passive, approach was used to generate a nearly linearly ramped current profile in a relativistic electron beam experiment carried out at the Brookhaven National Laboratory Accelerator Test Facility. Here, we report on these experimental results including beam and wakefieldmore » diagnostics and pulse profile reconstruction techniques.« less

Reconstitution of craniofacial osseous contour deformities, sequelae of trauma and post resection for tumors, with an alloplastic-autogenous graft.

PubMed

Leake, D L; Habal, M B

1977-04-01

Our experience using a new technique for reconstructing contour defects of facial bones has been presented. It employs particulate, cancellous bone and an implantable prosthesis accurately fabricated of polyether urethane and polyethylene terephthalate cloth mesh which can be produced in a variety of configurations. A mannequin made of these materials displaying the various parts of the craniofacial complex that have been restored or are currently under investigation is shown in Figure 10. Large cranial vault defects, orbital floors, mandibles including chin augmentation, and nasal bone deformities have been successfully restored in man. Restoration of the pinna of the ear is currently being evaluated in laboratory animals.

A Research Module for the Organic Chemistry Laboratory: Multistep Synthesis of a Fluorous Dye Molecule

PubMed Central

2014-01-01

A multi-session research-like module has been developed for use in the undergraduate organic teaching laboratory curriculum. Students are tasked with planning and executing the synthesis of a novel fluorous dye molecule and using it to explore a fluorous affinity chromatography separation technique, which is the first implementation of this technique in a teaching laboratory. Key elements of the project include gradually introducing students to the use of the chemical literature to facilitate their searching, as well as deliberate constraints designed to force them to think critically about reaction design and optimization in organic chemistry. The project also introduces students to some advanced laboratory practices such as Schlenk techniques, degassing of reaction mixtures, affinity chromatography, and microwave-assisted chemistry. This provides students a teaching laboratory experience that closely mirrors authentic synthetic organic chemistry practice in laboratories throughout the world. PMID:24501431

A Research Module for the Organic Chemistry Laboratory: Multistep Synthesis of a Fluorous Dye Molecule.

PubMed

Slade, Michael C; Raker, Jeffrey R; Kobilka, Brandon; Pohl, Nicola L B

2014-01-14

A multi-session research-like module has been developed for use in the undergraduate organic teaching laboratory curriculum. Students are tasked with planning and executing the synthesis of a novel fluorous dye molecule and using it to explore a fluorous affinity chromatography separation technique, which is the first implementation of this technique in a teaching laboratory. Key elements of the project include gradually introducing students to the use of the chemical literature to facilitate their searching, as well as deliberate constraints designed to force them to think critically about reaction design and optimization in organic chemistry. The project also introduces students to some advanced laboratory practices such as Schlenk techniques, degassing of reaction mixtures, affinity chromatography, and microwave-assisted chemistry. This provides students a teaching laboratory experience that closely mirrors authentic synthetic organic chemistry practice in laboratories throughout the world.

Structural design of the Sandia 34-M Vertical Axis Wind Turbine

NASA Astrophysics Data System (ADS)

Berg, D. E.

Sandia National Laboratories, as the lead DOE laboratory for Vertical Axis Wind Turbine (VAWT) development, is currently designing a 34-meter diameter Darrieus-type VAWT. This turbine will be a research test bed which provides a focus for advancing technology and validating design and fabrication techniques in a size range suitable for utility use. Structural data from this machine will allow structural modeling to be refined and verified for a turbine on which the gravity effects and stochastic wind loading are significant. Performance data from it will allow aerodynamic modeling to be refined and verified. The design effort incorporates Sandia's state-of-the-art analysis tools in the design of a complete machine. The analytic tools used in this design are discussed and the conceptual design procedure is described.

Failure Pressure and Leak Rate of Steam Generator Tubes With Stress Corrosion Cracks

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

Majumdar, S.; Kasza, K.; Park, J.Y.

2002-07-01

This paper illustrates the use of an 'equivalent rectangular crack' approach to predict leak rates through laboratory generated stress corrosion cracks. A comparison between predicted and observed test data on rupture and leak rate from laboratory generated stress corrosion cracks are provided. Specimen flaws were sized by post-test fractography in addition to pre-test advanced eddy current technique. The test failure pressures and leak rates are shown to be closer to those predicted on the basis of fractography than on NDE. However, the predictions based on NDE results are encouraging, particularly because they have the potential to determine a more detailedmore » geometry of ligamentous cracks from which more accurate predictions of failure pressure and leak rate can be made in the future. (authors)« less

Streamlining workflow and automation to accelerate laboratory scale protein production.

PubMed

Konczal, Jennifer; Gray, Christopher H

2017-05-01

Protein production facilities are often required to produce diverse arrays of proteins for demanding methodologies including crystallography, NMR, ITC and other reagent intensive techniques. It is common for these teams to find themselves a bottleneck in the pipeline of ambitious projects. This pressure to deliver has resulted in the evolution of many novel methods to increase capacity and throughput at all stages in the pipeline for generation of recombinant proteins. This review aims to describe current and emerging options to accelerate the success of protein production in Escherichia coli. We emphasize technologies that have been evaluated and implemented in our laboratory, including innovative molecular biology and expression vectors, small-scale expression screening strategies and the automation of parallel and multidimensional chromatography. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Determining the near-surface current profile from measurements of the wave dispersion relation

NASA Astrophysics Data System (ADS)

Smeltzer, Benjamin; Maxwell, Peter; Aesøy, Eirik; Ellingsen, Simen

2017-11-01

The current-induced Doppler shifts of waves can yield information about the background mean flow, providing an attractive method of inferring the current profile in the upper layer of the ocean. We present measurements of waves propagating on shear currents in a laboratory water channel, as well as theoretical investigations of inversion techniques for determining the vertical current structure. Spatial and temporal measurements of the free surface profile obtained using a synthetic Schlieren method are analyzed to determine the wave dispersion relation and Doppler shifts as a function of wavelength. The vertical current profile can then be inferred from the Doppler shifts using an inversion algorithm. Most existing algorithms rely on a priori assumptions of the shape of the current profile, and developing a method that uses less stringent assumptions is a focus of this study, allowing for measurement of more general current profiles. The accuracy of current inversion algorithms are evaluated by comparison to measurements of the mean flow profile from particle image velocimetry (PIV), and a discussion of the sensitivity to errors in the Doppler shifts is presented.

High Performance Liquid Chromatography Experiments to Undergraduate Laboratories

ERIC Educational Resources Information Center

Kissinger, Peter T.; And Others

1977-01-01

Reviews the principles of liquid chromatography with electrochemical detection (LCEC), an analytical technique that incorporates the advantages of both liquids chromatography and electrochemistry. Also suggests laboratory experiments using this technique. (MLH)

Novel techniques for biodiversity studies of gordiids and description of a new species of Chordodes (Gordiida, Nematomorpha) from Kenya, Africa.

PubMed

Bolek, Matthew G; Szmygiel, Cleo; Kubat, Austin; Schmidt-Rhaesa, Andreas; Hanelt, Ben

2013-01-01

We review recent advances in the use of non-adult gordiid cyst stages to locate gordiids over large geographical regions and new culturing techniques which can help overcome current difficulties in nematomorph biodiversity studies. Using these techniques, we collected a new species of gordiid as cysts in aquatic snails (Biomphalaria pfeifferi) from the Lake Victoria Basin, western Kenya, Africa and cultured them in the laboratory. We describe the adult free-living male and female worms using morphological (light and scanning electron microscopy) and molecular data as well as the life cycle, mating and oviposition behavior, egg strings, eggs, larvae, and cysts of this new species. Chordodes kenyaensis n. sp. belongs to a large group of African Chordodes in which simple areoles are smooth or superficially structured less so than "blackberry" areoles but contain filamentous projections. Present among the simple areoles are clusters of bulging areoles, crowned and circurmcluster areoles along with thorn and tubercle areoles. In the laboratory, worms developed and emerged within 53-78 days from three, species of laboratory-reared crickets exposed to cysts of this species. Adult male and female C. kenyaensis n. sp. initiated typical Gordian knots within hours to days of being placed together and males deposited masses of sperm on the cloacal region of females. Females began oviposition within a week of copulating and attached egg strings in a continuous zigzag pattern on small branches or air-hoses but never free in the water column. Larvae hatched within two to three weeks, and cysts developed in laboratory-reared and exposed snails within 14-24 days. Morphological characteristics of egg strings, eggs, larvae and cysts of C. kenyaensis were most similar to other gordiids in the genus Chordodes but differed morphologically from other gordiid genera for which similar information is available.

Development of Ecogenomic Sensors for Remote Detection of Marine Microbes, Their Genes and Gene Products

NASA Astrophysics Data System (ADS)

Scholin, C.; Preston, C.; Harris, A.; Birch, J.; Marin, R.; Jensen, S.; Roman, B.; Everlove, C.; Makarewicz, A.; Riot, V.; Hadley, D.; Benett, W.; Dzenitis, J.

2008-12-01

An internet search using the phrase "ecogenomic sensor" will return numerous references that speak broadly to the idea of detecting molecular markers indicative of specific organisms, genes or other biomarkers within an environmental context. However, a strict and unified definition of "ecogenomic sensor" is lacking and the phrase may be used for laboratory-based tools and techniques as well as semi or fully autonomous systems that can be deployed outside of laboratory. We are exploring development of an ecogenomic sensor from the perspective of a field-portable device applied towards oceanographic research and water quality monitoring. The device is known as the Environmental Sample Processor, or ESP. The ESP employs wet chemistry molecular analytical techniques to autonomously assess the presence and abundance of specific organisms, their genes and/or metabolites in near real-time. Current detection chemistries rely on low- density DNA probe and protein arrays. This presentation will emphasize results from 2007-8 field trials when the ESP was moored in Monterey Bay, CA, as well as current engineering activities for improving analytical capacity of the instrument. Changes in microbial community structure at the rRNA level were observed remotely in accordance with changing chemical and physical oceanographic conditions. Current developments include incorporation of a reusable solid phase extraction column for purifying nucleic acids and a 4-channel real-time PCR module. Users can configure this system to support a variety of PCR master mixes, primer/probe combinations and control templates. An update on progress towards fielding a PCR- enabled ESP will be given along with an outline of plans for its use in coastal and oligotrophic oceanic regimes.

A Streamlined Western Blot Exercise: An Efficient and Greener Approach in the Laboratory Classroom

ERIC Educational Resources Information Center

Ness, Traci L.; Robinson, Rebekah L.; Mojadedi, Wais; Peavy, Lydia; Weiland, Mitch H.

2015-01-01

SDS-PAGE and western blotting are two commonly taught protein detection techniques in biochemistry and molecular biology laboratory classrooms. A pitfall associated with incorporating these techniques into the laboratory is the significant wait times that do not allow students to obtain timely results. The waiting associated with SDS-PAGE comes…

Laboratory instrumentation and techniques for characterizing multi-junction solar cells for space applications

NASA Technical Reports Server (NTRS)

Woodyard, James R.

1995-01-01

Multi-junction solar cells are attractive for space applications because they can be designed to convert a larger fraction of AMO into electrical power at a lower cost than single-junction cells. The performance of multi-junction cells is much more sensitive to the spectral irradiance of the illuminating source than single-junction cells. The design of high efficiency multi-junction cells for space applications requires matching the optoelectronic properties of the junctions to AMO spectral irradiance. Unlike single-junction cells, it is not possible to carry out quantum efficiency measurements using only a monochromatic probe beam and determining the cell short-circuit current assuming linearity of the quantum efficiency. Additionally, current-voltage characteristics can not be calculated from measurements under non-AMO light sources using spectral-correction methods. There are reports in the literature on characterizing the performance of multi junction cells by measuring and convoluting the quantum efficiency of each junction with the spectral irradiance; the technique is of limited value for the characterization of cell performance under AMO power-generating conditions. We report the results of research to develop instrumentation and techniques for characterizing multi junction solar cells for space . An integrated system is described which consists of a standard lamp, spectral radiometer, dual-source solar simulator, and personal computer based current-voltage and quantum efficiency equipment. The spectral radiometer is calibrated regularly using the tungsten-halogen standard lamp which has a calibration based on NIST scales. The solar simulator produces the light bias beam for current-voltage and cell quantum efficiency measurements. The calibrated spectral radiometer is used to 'fit' the spectral irradiance of the dual-source solar simulator to WRL AMO data. The quantum efficiency apparatus includes a monochromatic probe beam for measuring the absolute cell quantum efficiency at various voltage biases, including the voltage bias corresponding to the maximum-power point under AMO light bias. The details of the procedures to 'fit' the spectral irradiance to AMO will be discussed. An assessment of the role of the accuracy of the 'fit' of the spectral irradiance and probe beam intensity on measured cell characteristics will be presented. quantum efficiencies were measured with both spectral light bias and AMO light bias; the measurements show striking differences. Spectral irradiances were convoluted with cell quantum efficiencies to calculate cell currents as function of voltage. The calculated currents compare with measured currents at the 1% level. Measurements on a variety of multi-junction cells will be presented. The dependence of defects in junctions on cell quantum efficiencies measured under light and voltage bias conditions will be presented. Comments will be made on issues related to standards for calibration, and limitations of the instrumentation and techniques. Expeditious development of multi-junction solar cell technology for space presents challenges for cell characterization in the laboratory.

Development of a Shipboard Remote Control and Telemetry Experimental System for Large-Scale Model’s Motions and Loads Measurement in Realistic Sea Waves

PubMed Central

Jiao, Jialong; Ren, Huilong; Adenya, Christiaan Adika; Chen, Chaohe

2017-01-01

Wave-induced motion and load responses are important criteria for ship performance evaluation. Physical experiments have long been an indispensable tool in the predictions of ship’s navigation state, speed, motions, accelerations, sectional loads and wave impact pressure. Currently, majority of the experiments are conducted in laboratory tank environment, where the wave environments are different from the realistic sea waves. In this paper, a laboratory tank testing system for ship motions and loads measurement is reviewed and reported first. Then, a novel large-scale model measurement technique is developed based on the laboratory testing foundations to obtain accurate motion and load responses of ships in realistic sea conditions. For this purpose, a suite of advanced remote control and telemetry experimental system was developed in-house to allow for the implementation of large-scale model seakeeping measurement at sea. The experimental system includes a series of technique sensors, e.g., the Global Position System/Inertial Navigation System (GPS/INS) module, course top, optical fiber sensors, strain gauges, pressure sensors and accelerometers. The developed measurement system was tested by field experiments in coastal seas, which indicates that the proposed large-scale model testing scheme is capable and feasible. Meaningful data including ocean environment parameters, ship navigation state, motions and loads were obtained through the sea trial campaign. PMID:29109379

The 3 H(d , γ) Reaction at Ec . m . <= 300 keV

NASA Astrophysics Data System (ADS)

Parker, C. E.; Brune, C. R.; Massey, T. N.; O'Donnell, J. E.; Richard, A. L.; Sayre, D. B.

2015-04-01

The 3 H(d , γ) 5He reaction has been measured using a 500-keV pulsed deuteron beam incident on a stopping titanium tritide target at the Edwards Accelerator Laboratory. The time-of-flight technique has been used to distinguish the γ-rays from neutrons in the bismuth germinate (BGO) γ-ray detector. A stilbene scintillator and an NE-213 scintillator have been used to detect the neutrons from the 3 H(d , n) α reaction using both the pulse-shape discrimination and time-of-flight techniques. A newly designed target holder with a silicon surface barrier detector to simultaneously measure α-particles to normalize the number of neutrons, along with a new titanium tritide target, was incorporated for subsequent measurements. The γ-rays have been measured at laboratory angles of 0 °, 45 °, 90 °, and 135 °. Information about the γ-ray energy distribution for the unbound ground state and first excited state of 5He can be obtained experimentally by comparing the BGO data to Monte Carlo simulations. The 3 H(d , γ) /3 H(d , n) branching ratio has also been measured. Data analysis is currently underway for the subsequent measurements. This work is supported in part by Lawrence Livermore National Laboratory and the U.S. D.O.E. (NNSA) through Grant No. DE-NA0001837.

Extracting laboratory test information from biomedical text

PubMed Central

Kang, Yanna Shen; Kayaalp, Mehmet

2013-01-01

Background: No previous study reported the efficacy of current natural language processing (NLP) methods for extracting laboratory test information from narrative documents. This study investigates the pathology informatics question of how accurately such information can be extracted from text with the current tools and techniques, especially machine learning and symbolic NLP methods. The study data came from a text corpus maintained by the U.S. Food and Drug Administration, containing a rich set of information on laboratory tests and test devices. Methods: The authors developed a symbolic information extraction (SIE) system to extract device and test specific information about four types of laboratory test entities: Specimens, analytes, units of measures and detection limits. They compared the performance of SIE and three prominent machine learning based NLP systems, LingPipe, GATE and BANNER, each implementing a distinct supervised machine learning method, hidden Markov models, support vector machines and conditional random fields, respectively. Results: Machine learning systems recognized laboratory test entities with moderately high recall, but low precision rates. Their recall rates were relatively higher when the number of distinct entity values (e.g., the spectrum of specimens) was very limited or when lexical morphology of the entity was distinctive (as in units of measures), yet SIE outperformed them with statistically significant margins on extracting specimen, analyte and detection limit information in both precision and F-measure. Its high recall performance was statistically significant on analyte information extraction. Conclusions: Despite its shortcomings against machine learning methods, a well-tailored symbolic system may better discern relevancy among a pile of information of the same type and may outperform a machine learning system by tapping into lexically non-local contextual information such as the document structure. PMID:24083058

Laboratory Astrochemistry: Interstellar PAH Analogs

NASA Technical Reports Server (NTRS)

Salama, Farid; DeVincenzi, Donald L. (Technical Monitor)

2000-01-01

Polycyclic aromatic hydrocarbons (PAHs) are now considered to be an important and ubiquitous component of the organic material in space. PAHs are found in a large variety of extraterrestrial materials such as interplanetary dust particles (IDPs) and meteoritic materials. PAHs are also good candidates to account for the infrared emission bands (UIRs) and the diffuse interstellar optical absorption bands (DIBs) detected in various regions of the interstellar medium. The recent observations made with the Infrared Space Observatory (ISO) have confirmed the ubiquitous nature of the UIR bands and their carriers. PAHs are though to form through chemical reactions in the outflow from carbon-rich stars in a process similar to soot formation. Once injected in the interstellar medium, PAHs are further processed by the interstellar radiation field, interstellar shocks and energetic particles. A major, dedicated, laboratory effort has been undertaken over the past years to measure the physical and chemical characteristics of these complex molecules and their ions under experimental conditions that mimic the interstellar conditions. These measurements require collision-free conditions where the molecules and ions are cold and chemically isolated. The spectroscopy of PAHs under controlled conditions represents an essential diagnostic tool to study the evolution of extraterrestrial PAHs. The Astrochemistry Laboratory program will be discussed through its multiple aspects: objectives, approach and techniques adopted, adaptability to the nature of the problem(s), results and implications for astronomy as well as for molecular spectroscopy. A review of the data generated through laboratory simulations of space environments and the role these data have played in our current understanding of the properties of interstellar PAHs will be presented. The discussion will also introduce the newest generation of laboratory experiments that are currently being developed in order to provide a closer simulation of space environments and a better support to space missions.

Laboratory Studies of Interstellar PAH Analogs

NASA Technical Reports Server (NTRS)

Salama, Farid; DeVincenzi, Donald (Technical Monitor)

2000-01-01

Polycyclic aromatic hydrocarbons (PAHs) are now considered to be an important and ubiquitous component of the organic material in space. PAHs are found in a large variety of extraterrestrial materials such as interplanetary dust particles (IDPs) and meteoritic materials. PAHs are also good candidates to account for the infrared emission bands (UIRs) and the diffuse interstellar optical absorption bands (DIBs) detected in various regions of the interstellar medium. The recent observations made with the Infrared Space Observatory (ISO) have confirmed the ubiquitous nature of the UIR bands and their carriers. PAHs are though to form through chemical reactions in the outflow from carbon-rich stars in a process similar to soot formation. Once injected in the interstellar medium, PAHs are further processed by the interstellar radiation field, interstellar shocks and energetic particles. A major, dedicated, laboratory effort has been undertaken over the past years to measure the physical and chemical characteristics of these complex molecules and their ions under experimental conditions that mimic the interstellar conditions. These measurements require collision-free conditions where the molecules and ions are cold and chemically isolated. The spectroscopy of PAHs under controlled conditions represents an essential diagnostic tool to study the evolution of extraterrestrial PAHs. The Astrochemistry Laboratory program will be discussed through its multiple aspects: objectives, approach and techniques adopted, adaptability to the nature of the problem(s), results and implications for astronomy as well as for molecular spectroscopy. A review of the data generated through laboratory simulations of space environments and the role these data have played in our current understanding of the properties of interstellar PAHs will be presented. The discussion will also introduce the newest generation of laboratory experiments that are currently being developed in order to provide a closer simulation of space environments and a better support to space missions.

Optimization of the tungsten oxide technique for measurement of atmospheric ammonia

NASA Technical Reports Server (NTRS)

Brown, Kenneth G.

1987-01-01

Hollow tubes coated with tungstic acid have been shown to be of value in the determination of ammonia and nitric acid in ambient air. Practical application of this technique was demonstrated utilizing an automated sampling system for in-flight collection and analysis of atmospheric samples. Due to time constraints these previous measurements were performed on tubes that had not been well characterized in the laboratory. As a result the experimental precision could not be accurately estimated. Since the technique was being compared to other techniques for measuring these compounds, it became necessary to perform laboratory tests which would establish the reliability of the technique. This report is a summary of these laboratory experiments as they are applied to the determination of ambient ammonia concentration.

Performance of optimized McRAPD in identification of 9 yeast species frequently isolated from patient samples: potential for automation.

PubMed

Trtkova, Jitka; Pavlicek, Petr; Ruskova, Lenka; Hamal, Petr; Koukalova, Dagmar; Raclavsky, Vladislav

2009-11-10

Rapid, easy, economical and accurate species identification of yeasts isolated from clinical samples remains an important challenge for routine microbiological laboratories, because susceptibility to antifungal agents, probability to develop resistance and ability to cause disease vary in different species. To overcome the drawbacks of the currently available techniques we have recently proposed an innovative approach to yeast species identification based on RAPD genotyping and termed McRAPD (Melting curve of RAPD). Here we have evaluated its performance on a broader spectrum of clinically relevant yeast species and also examined the potential of automated and semi-automated interpretation of McRAPD data for yeast species identification. A simple fully automated algorithm based on normalized melting data identified 80% of the isolates correctly. When this algorithm was supplemented by semi-automated matching of decisive peaks in first derivative plots, 87% of the isolates were identified correctly. However, a computer-aided visual matching of derivative plots showed the best performance with average 98.3% of the accurately identified isolates, almost matching the 99.4% performance of traditional RAPD fingerprinting. Since McRAPD technique omits gel electrophoresis and can be performed in a rapid, economical and convenient way, we believe that it can find its place in routine identification of medically important yeasts in advanced diagnostic laboratories that are able to adopt this technique. It can also serve as a broad-range high-throughput technique for epidemiological surveillance.

A decision-theoretic approach to the display of information for time-critical decisions: The Vista project

NASA Technical Reports Server (NTRS)

Horvitz, Eric; Ruokangas, Corinne; Srinivas, Sampath; Barry, Matthew

1993-01-01

We describe a collaborative research and development effort between the Palo Alto Laboratory of the Rockwell Science Center, Rockwell Space Operations Company, and the Propulsion Systems Section of NASA JSC to design computational tools that can manage the complexity of information displayed to human operators in high-stakes, time-critical decision contexts. We shall review an application from NASA Mission Control and describe how we integrated a probabilistic diagnostic model and a time-dependent utility model, with techniques for managing the complexity of computer displays. Then, we shall describe the behavior of VPROP, a system constructed to demonstrate promising display-management techniques. Finally, we shall describe our current research directions on the Vista 2 follow-on project.

Hyperspectral Remote Sensing and Ecological Modeling Research and Education at Mid America Remote Sensing Center (MARC): Field and Laboratory Enhancement

NASA Technical Reports Server (NTRS)

Cetin, Haluk

1999-01-01

The purpose of this project was to establish a new hyperspectral remote sensing laboratory at the Mid-America Remote sensing Center (MARC), dedicated to in situ and laboratory measurements of environmental samples and to the manipulation, analysis, and storage of remotely sensed data for environmental monitoring and research in ecological modeling using hyperspectral remote sensing at MARC, one of three research facilities of the Center of Reservoir Research at Murray State University (MSU), a Kentucky Commonwealth Center of Excellence. The equipment purchased, a FieldSpec FR portable spectroradiometer and peripherals, and ENVI hyperspectral data processing software, allowed MARC to provide hands-on experience, education, and training for the students of the Department of Geosciences in quantitative remote sensing using hyperspectral data, Geographic Information System (GIS), digital image processing (DIP), computer, geological and geophysical mapping; to provide field support to the researchers and students collecting in situ and laboratory measurements of environmental data; to create a spectral library of the cover types and to establish a World Wide Web server to provide the spectral library to other academic, state and Federal institutions. Much of the research will soon be published in scientific journals. A World Wide Web page has been created at the web site of MARC. Results of this project are grouped in two categories, education and research accomplishments. The Principal Investigator (PI) modified remote sensing and DIP courses to introduce students to ii situ field spectra and laboratory remote sensing studies for environmental monitoring in the region by using the new equipment in the courses. The PI collected in situ measurements using the spectroradiometer for the ER-2 mission to Puerto Rico project for the Moderate Resolution Imaging Spectrometer (MODIS) Airborne Simulator (MAS). Currently MARC is mapping water quality in Kentucky Lake and vegetation in the Land-Between-the Lakes (LBL) using Landsat-TM data. A Landsat-TM scene of the same day was obtained to relate ground measurements to the satellite data. A spectral library has been created for overstory species in LBL. Some of the methods, such as NPDF and IDFD techniques for spectral unmixing and reduction of effects of shadows in classifications- comparison of hyperspectral classification techniques, and spectral nonlinear and linear unmixing techniques, are being tested using the laboratory.

The Effectiveness of Active and Traditional Teaching Techniques in the Orthopedic Assessment Laboratory

ERIC Educational Resources Information Center

Nottingham, Sara; Verscheure, Susan

2010-01-01

Active learning is a teaching methodology with a focus on student-centered learning that engages students in the educational process. This study implemented active learning techniques in an orthopedic assessment laboratory, and the effects of these teaching techniques. Mean scores from written exams, practical exams, and final course evaluations…

PROJECT SUCCESS: Marine Science. (Introductory Packet, Basic Marine Science Laboratory Techniques, Oceanographic Instruments, Individual Projects, Bibliography).

ERIC Educational Resources Information Center

Demaray, Bryan

Five packets comprise the marine science component of an enrichment program for gifted elementary students. Considered in the introductory section are identification (pre/post measure) procedures. Remaining packets address the following topics (subtopics in parentheses): basic marine science laboratory techniques (microscope techniques and metric…

Considerations for standardizing predictive molecular pathology for cancer prognosis.

PubMed

Fiorentino, Michelangelo; Scarpelli, Marina; Lopez-Beltran, Antonio; Cheng, Liang; Montironi, Rodolfo

2017-01-01

Molecular tests that were once ancillary to the core business of cyto-histopathology are becoming the most relevant workload in pathology departments after histopathology/cytopathology and before autopsies. This has resulted from innovations in molecular biology techniques, which have developed at an incredibly fast pace. Areas covered: Most of the current widely used techniques in molecular pathology such as FISH, direct sequencing, pyrosequencing, and allele-specific PCR will be replaced by massive parallel sequencing that will not be considered next generation, but rather, will be considered to be current generation sequencing. The pre-analytical steps of molecular techniques such as DNA extraction or sample preparation will be largely automated. Moreover, all the molecular pathology instruments will be part of an integrated workflow that traces the sample from extraction to the analytical steps until the results are reported; these steps will be guided by expert laboratory information systems. In situ hybridization and immunohistochemistry for quantification will be largely digitalized as much as histology will be mostly digitalized rather than viewed using microscopy. Expert commentary: This review summarizes the technical and regulatory issues concerning the standardization of molecular tests in pathology. A vision of the future perspectives of technological changes is also provided.

Blood doping by cobalt. Should we measure cobalt in athletes?

PubMed

Lippi, Giuseppe; Franchini, Massimo; Guidi, Gian Cesare

2006-07-24

Blood doping is commonplace in competitive athletes who seek to enhance their aerobic performances through illicit techniques. Cobalt, a naturally-occurring element with properties similar to those of iron and nickel, induces a marked and stable polycythemic response through a more efficient transcription of the erythropoietin gene. Although little information is available so far on cobalt metabolism, reference value ranges or supplementation in athletes, there is emerging evidence that cobalt is used as a supplement and increased serum concentrations are occasionally observed in athletes. Therefore, given the athlete's connatural inclination to experiment with innovative, unfair and potentially unhealthy doping techniques, cobalt administration might soon become the most suited complement or surrogate for erythropoiesis-stimulating substances. Nevertheless, cobalt administration is not free from unsafe consequences, which involve toxic effects on heart, liver, kidney, thyroid and cancer promotion. Cobalt is easily purchasable, inexpensive and not currently comprehended within the World Anti-Doping Agency prohibited list. Moreover, available techniques for measuring whole blood, serum, plasma or urinary cobalt involve analytic approaches which are currently not practical for antidoping laboratories. Thus more research on cobalt metabolism in athletes is compelling, along with implementation of effective strategies to unmask this potentially deleterious doping practice.

Quasi-isentropic compression of materials using the magnetic loading technique

NASA Astrophysics Data System (ADS)

Ao, Tommy

2009-06-01

The Isentropic Compression Experiment (ICE) technique has proven to be a valuable complement to the well-established method of shock compression of condensed matter. The magnetic loading technique using pulsed power generators was first developed about a decade ago on the Z Accelerator, and has matured significantly. The recent development of small pulsed power generators have enabled several key issues in ICE, such as panel & sample preparation, uniformity of loading, and edge effects to be studied. Veloce is a medium-voltage, high-current, compact pulsed power generator developed for cost effective isentropic experiments. The machine delivers up to 3 MA of current rapidly (˜ 440-530 ns) into an inductive load where significant magnetic pressures are produced. Examples of recent material strength measurements from quasi-isentropic loading and unloading of materials will be presented. In particular, the influence that the strength of interferometer windows has on wave profile analyses and thus the inferred strength of materials is examined. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the U.S. Department of Energy's National Nuclear Security Administration under Contract No. DE-AC04-94AL85000.

Technique for the comparison of light spectra from natural and laboratory generated lightning current arcs

NASA Astrophysics Data System (ADS)

Mitchard, D.; Clark, D.; Carr, D.; Haddad, A.

2016-08-01

A technique was developed for the comparison of observed emission spectra from lightning current arcs generated through self-breakdown in air and the use of two types of initiation wire, aluminum bronze and nichrome, against previously published spectra of natural lightning events. A spectrograph system was used in which the wavelength of light emitted by the lightning arc was analyzed to derive elemental interactions. A lightning impulse of up to 100 kA was applied to a two hemispherical tungsten electrode configuration which allowed the effect of the lightning current and lightning arc length to be investigated. A natural lightning reference spectrum was reconstructed from literature, and generated lightning spectra were obtained from self-breakdown across a 14.0 mm air gap and triggered along initiation wires of length up to 72.4 mm. A comparison of the spectra showed that the generated lightning arc induced via self-breakdown produced a very similar spectrum to that of natural lightning, with the addition of only a few lines from the tungsten electrodes. A comparison of the results from the aluminum bronze initiation wire showed several more lines, whereas results from the nichrome initiation wire differed greatly across large parts of the spectrum. This work highlights the potential use for spectrographic techniques in the study of lightning interactions with surrounding media and materials, and in natural phenomena such as recently observed ball lightning.

Surgical simulation in orthopaedic skills training.

PubMed

Atesok, Kivanc; Mabrey, Jay D; Jazrawi, Laith M; Egol, Kenneth A

2012-07-01

Mastering rapidly evolving orthopaedic surgical techniques requires a lengthy period of training. Current work-hour restrictions and cost pressures force trainees to face the challenge of acquiring more complex surgical skills in a shorter amount of time. As a result, alternative methods to improve the surgical skills of orthopaedic trainees outside the operating room have been developed. These methods include hands-on training in a laboratory setting using synthetic bones or cadaver models as well as software tools and computerized simulators that enable trainees to plan and simulate orthopaedic operations in a three-dimensional virtual environment. Laboratory-based training offers potential benefits in the development of basic surgical skills, such as using surgical tools and implants appropriately, achieving competency in procedures that have a steep learning curve, and assessing already acquired skills while minimizing concerns for patient safety, operating room time, and financial constraints. Current evidence supporting the educational advantages of surgical simulation in orthopaedic skills training is limited. Despite this, positive effects on the overall education of orthopaedic residents, and on maintaining the proficiency of practicing orthopaedic surgeons, are anticipated.

Ultrasound assisted extraction of food and natural products. Mechanisms, techniques, combinations, protocols and applications. A review.

PubMed

Chemat, Farid; Rombaut, Natacha; Sicaire, Anne-Gaëlle; Meullemiestre, Alice; Fabiano-Tixier, Anne-Sylvie; Abert-Vian, Maryline

2017-01-01

This review presents a complete picture of current knowledge on ultrasound-assisted extraction (UAE) in food ingredients and products, nutraceutics, cosmetic, pharmaceutical and bioenergy applications. It provides the necessary theoretical background and some details about extraction by ultrasound, the techniques and their combinations, the mechanisms (fragmentation, erosion, capillarity, detexturation, and sonoporation), applications from laboratory to industry, security, and environmental impacts. In addition, the ultrasound extraction procedures and the important parameters influencing its performance are also included, together with the advantages and the drawbacks of each UAE techniques. Ultrasound-assisted extraction is a research topic, which affects several fields of modern plant-based chemistry. All the reported applications have shown that ultrasound-assisted extraction is a green and economically viable alternative to conventional techniques for food and natural products. The main benefits are decrease of extraction and processing time, the amount of energy and solvents used, unit operations, and CO 2 emissions. Copyright © 2016 Elsevier B.V. All rights reserved.

Molecular filter based planar Doppler velocimetry

NASA Astrophysics Data System (ADS)

Elliott, Gregory S.; Beutner, Thomas J.

1999-11-01

Molecular filter based diagnostics are continuing to gain popularity as a research tool for investigations in areas of aerodynamics, fluid mechanics, and combustion. This class of diagnostics has gone by many terms including Filtered Rayleigh Scattering, Doppler Global Velocimetry, and Planar Doppler Velocimetry. The majority of this article reviews recent advances in Planar Doppler Velocimetry in measuring up to three velocity components over a planar region in a flowfield. The history of the development of these techniques is given with a description of typical systems, components, and levels of uncertainty in the measurement. Current trends indicate that uncertainties on the order of 1 m/s are possible with these techniques. A comprehensive review is also given on the application of Planar Doppler Velocimetry to laboratory flows, supersonic flows, and large scale subsonic wind tunnels. The article concludes with a description of future trends, which may simplify the technique, followed by a description of techniques which allow multi-property measurements (i.e. velocity, density, temperature, and pressure) simultaneously.

Electromigration techniques--a fast and economical tool for differentiation of similar strains of microorganisms.

PubMed

Horká, Marie; Horký, Jaroslav; Kubesová, Anna; Mazanec, Karel; Matousková, Hana; Slais, Karel

2010-07-01

The detection and identification of pathogens currently relies upon a very diverse range of techniques and skills, from traditional cultivation and taxonomic procedures to modern rapid and sensitive diagnostic methods. Real-time PCR is now exploited as a front line diagnostic screening tool in human, animal and plant health as well as bio-security. Nevertheless, new techniques for pathogen identification, particularly of unknown samples, are needed. In this study we propose the combination of electrophoresis-based procedures for the fast differentiation of microorganisms. The method feasibility is proved on the model of seven similar strains of Pseudomonas syringae pathovars from 37 sources, identified by gas chromatography of fatty acid methyl esters. The results from the routine laboratory were compared with results of the combination of the developed capillary and gel electrophoresis as well as mass spectrometry. According to our experiments appropriate combination of electromigration techniques appears to be useful for the fast and economical differentiation of unknown microorganisms.

Revitalizing pathology laboratories in a gastrointestinal pathophysiology course using multimedia and team-based learning techniques.

PubMed

Carbo, Alexander R; Blanco, Paola G; Graeme-Cooke, Fiona; Misdraji, Joseph; Kappler, Steven; Shaffer, Kitt; Goldsmith, Jeffrey D; Berzin, Tyler; Leffler, Daniel; Najarian, Robert; Sepe, Paul; Kaplan, Jennifer; Pitman, Martha; Goldman, Harvey; Pelletier, Stephen; Hayward, Jane N; Shields, Helen M

2012-05-15

In 2008, we changed the gastrointestinal pathology laboratories in a gastrointestinal pathophysiology course to a more interactive format using modified team-based learning techniques and multimedia presentations. The results were remarkably positive and can be used as a model for pathology laboratory improvement in any organ system. Over a two-year period, engaging and interactive pathology laboratories were designed. The initial restructuring of the laboratories included new case material, Digital Atlas of Video Education Project videos, animations and overlays. Subsequent changes included USMLE board-style quizzes at the beginning of each laboratory, with individual readiness assessment testing and group readiness assessment testing, incorporation of a clinician as a co-teacher and role playing for the student groups. Student responses for pathology laboratory contribution to learning improved significantly compared to baseline. Increased voluntary attendance at pathology laboratories was observed. Spontaneous student comments noted the positive impact of the laboratories on their learning. Pathology laboratory innovations, including modified team-based learning techniques with individual and group self-assessment quizzes, multimedia presentations, and paired teaching by a pathologist and clinical gastroenterologist led to improvement in student perceptions of pathology laboratory contributions to their learning and better pathology faculty evaluations. These changes can be universally applied to other pathology laboratories to improve student satisfaction. Copyright © 2012 Elsevier GmbH. All rights reserved.

Evaluating High-Throughput Ab Initio Gene Finders to Discover Proteins Encoded in Eukaryotic Pathogen Genomes Missed by Laboratory Techniques

PubMed Central

Goodswen, Stephen J.; Kennedy, Paul J.; Ellis, John T.

2012-01-01

Next generation sequencing technology is advancing genome sequencing at an unprecedented level. By unravelling the code within a pathogen’s genome, every possible protein (prior to post-translational modifications) can theoretically be discovered, irrespective of life cycle stages and environmental stimuli. Now more than ever there is a great need for high-throughput ab initio gene finding. Ab initio gene finders use statistical models to predict genes and their exon-intron structures from the genome sequence alone. This paper evaluates whether existing ab initio gene finders can effectively predict genes to deduce proteins that have presently missed capture by laboratory techniques. An aim here is to identify possible patterns of prediction inaccuracies for gene finders as a whole irrespective of the target pathogen. All currently available ab initio gene finders are considered in the evaluation but only four fulfil high-throughput capability: AUGUSTUS, GeneMark_hmm, GlimmerHMM, and SNAP. These gene finders require training data specific to a target pathogen and consequently the evaluation results are inextricably linked to the availability and quality of the data. The pathogen, Toxoplasma gondii, is used to illustrate the evaluation methods. The results support current opinion that predicted exons by ab initio gene finders are inaccurate in the absence of experimental evidence. However, the results reveal some patterns of inaccuracy that are common to all gene finders and these inaccuracies may provide a focus area for future gene finder developers. PMID:23226328

Occurrence of lignin degradation genotypes and phenotypes among prokaryotes.

PubMed

Tian, Jiang-Hao; Pourcher, Anne-Marie; Bouchez, Théodore; Gelhaye, Eric; Peu, Pascal

2014-12-01

A number of prokaryotes actively contribute to lignin degradation in nature and their activity could be of interest for many applications including the production of biogas/biofuel from lignocellulosic biomass and biopulping. This review compares the reliability and efficiency of the culture-dependent screening methods currently used for the isolation of ligninolytic prokaryotes. Isolated prokaryotes exhibiting lignin-degrading potential are presented according to their phylogenetic groups. With the development of bioinformatics, culture-independent techniques are emerging that allow larger-scale data mining for ligninolytic prokaryotic functions but today, these techniques still have some limits. In this work, two phylogenetic affiliations of isolated prokaryotes exhibiting ligninolytic potential and laccase-encoding prokaryotes were determined on the basis of 16S rDNA sequences, providing a comparative view of results obtained by the two types of screening techniques. The combination of laboratory culture and bioinformatics approaches is a promising way to explore lignin-degrading prokaryotes.

Cost-effective broad-band electrical impedance spectroscopy measurement circuit and signal analysis for piezo-materials and ultrasound transducers

PubMed Central

Lewis, George K; Lewis, George K; Olbricht, William

2008-01-01

This paper explains the circuitry and signal processing to perform electrical impedance spectroscopy on piezoelectric materials and ultrasound transducers. Here, we measure and compare the impedance spectra of 2−5 MHz piezoelectrics, but the methodology applies for 700 kHz–20 MHz ultrasonic devices as well. Using a 12 ns wide 5 volt pulsing circuit as an impulse, we determine the electrical impedance curves experimentally using Ohm's law and fast Fourier transform (FFT), and compare results with mathematical models. The method allows for rapid impedance measurement for a range of frequencies using a narrow input pulse, digital oscilloscope and FFT techniques. The technique compares well to current methodologies such as network and impedance analyzers while providing additional versatility in the electrical impedance measurement. The technique is theoretically simple, easy to implement and completed with ordinary laboratory instrumentation for minimal cost. PMID:19081773

Penning trap mass spectrometry Q-value determinations for highly forbidden β-decays

NASA Astrophysics Data System (ADS)

Sandler, Rachel; Bollen, Georg; Eibach, Martin; Gamage, Nadeesha; Gulyuz, Kerim; Hamaker, Alec; Izzo, Chris; Kandegedara, Rathnayake; Redshaw, Matt; Ringle, Ryan; Valverde, Adrian; Yandow, Isaac; Low Energy Beam Ion Trap Team

2017-09-01

Over the last several decades, extremely sensitive, ultra-low background beta and gamma detection techniques have been developed. These techniques have enabled the observation of very rare processes, such as highly forbidden beta decays e.g. of 113Cd, 50V and 138La. Half-life measurements of highly forbidden beta decays provide a testing ground for theoretical nuclear models, and the comparison of calculated and measured energy spectra could enable a determination of the values of the weak coupling constants. Precision Q-value measurements also allow for systematic tests of the beta-particle detection techniques. We will present the results and current status of Q value determinations for highly forbidden beta decays. The Q values, the mass difference between parent and daughter nuclides, are measured using the high precision Penning trap mass spectrometer LEBIT at the National Superconducting Cyclotron Laboratory.

Development of W/C soft x-ray multilayer mirror by ion beam sputtering (IBS) system for below 50A wavelength

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

Biswas, A.; Bhattacharyya, D.

A home-made Ion Beam Sputtering (IBS) system has been developed in our laboratory. Using the IBS system single layer W and single layer C film has been deposited at 1000eV Ar ion energy and 10mA ion current. The W-film has been characterized by grazing Incidence X-ray reflectrometry (GIXR) technique and Atomic Force Microscope technique. The single layer C-film has been characterized by Spectroscopic Ellipsometric technique. At the same deposition condition 25-layer W/C multilayer film has been deposited which has been designed for using as mirror at 30 Degree-Sign grazing incidence angle around 50A wavelength. The multilayer sample has been characterizedmore » by measuring reflectivity of CuK{alpha} radiation and soft x-ray radiation around 50A wavelength.« less

Development of a high average current polarized electron source with long cathode operational lifetime

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

C. K. Sinclair; P. A. Adderley; B. M. Dunham

Substantially more than half of the electromagnetic nuclear physics experiments conducted at the Continuous Electron Beam Accelerator Facility of the Thomas Jefferson National Accelerator Facility (Jefferson Laboratory) require highly polarized electron beams, often at high average current. Spin-polarized electrons are produced by photoemission from various GaAs-based semiconductor photocathodes, using circularly polarized laser light with photon energy slightly larger than the semiconductor band gap. The photocathodes are prepared by activation of the clean semiconductor surface to negative electron affinity using cesium and oxidation. Historically, in many laboratories worldwide, these photocathodes have had short operational lifetimes at high average current, and havemore » often deteriorated fairly quickly in ultrahigh vacuum even without electron beam delivery. At Jefferson Lab, we have developed a polarized electron source in which the photocathodes degrade exceptionally slowly without electron emission, and in which ion back bombardment is the predominant mechanism limiting the operational lifetime of the cathodes during electron emission. We have reproducibly obtained cathode 1/e dark lifetimes over two years, and 1/e charge density and charge lifetimes during electron beam delivery of over 2?105???C/cm2 and 200 C, respectively. This source is able to support uninterrupted high average current polarized beam delivery to three experimental halls simultaneously for many months at a time. Many of the techniques we report here are directly applicable to the development of GaAs photoemission electron guns to deliver high average current, high brightness unpolarized beams.« less

Myoglobin structure and function: A multiweek biochemistry laboratory project.

PubMed

Silverstein, Todd P; Kirk, Sarah R; Meyer, Scott C; Holman, Karen L McFarlane

2015-01-01

We have developed a multiweek laboratory project in which students isolate myoglobin and characterize its structure, function, and redox state. The important laboratory techniques covered in this project include size-exclusion chromatography, electrophoresis, spectrophotometric titration, and FTIR spectroscopy. Regarding protein structure, students work with computer modeling and visualization of myoglobin and its homologues, after which they spectroscopically characterize its thermal denaturation. Students also study protein function (ligand binding equilibrium) and are instructed on topics in data analysis (calibration curves, nonlinear vs. linear regression). This upper division biochemistry laboratory project is a challenging and rewarding one that not only exposes students to a wide variety of important biochemical laboratory techniques but also ties those techniques together to work with a single readily available and easily characterized protein, myoglobin. © 2015 International Union of Biochemistry and Molecular Biology.

Doing That Thing That Scientists Do: A Discovery-Driven Module on Protein Purification and Characterization for the Undergraduate Biochemistry Laboratory Classroom

ERIC Educational Resources Information Center

Garrett, Teresa A.; Osmundson, Joseph; Isaacson, Marisa; Herrera, Jennifer

2015-01-01

In traditional introductory biochemistry laboratory classes students learn techniques for protein purification and analysis by following provided, established, step-by-step procedures. Students are exposed to a variety of biochemical techniques but are often not developing procedures or collecting new, original data. In this laboratory module,…

Modeling Laser Effects on Imaging Spacecraft Using the SSM

NASA Astrophysics Data System (ADS)

Buehler, P.; Smith, J.; Farmer, J.; Bonn, D.

The Satellite Survivability Module (SSM) is an end-to-end, physics-based, performance prediction model for directed energy engagement of orbiting spacecraft. Two engagement types are currently supported: laser engagement of the focal plane array of an imaging spacecraft; and Radio Frequency (RF) engagement of spacecraft components. For laser engagements, the user creates a spacecraft, its optical system, any protection techniques used by the optical system, a laser threat, and an atmosphere through which the laser will pass. For RF engagements, the user creates a spacecraft (as a set of subsystem components), any protection techniques, and an RF source. SSM then models the engagement and its impact on the spacecraft using four impact levels: degradation, saturation, damage, and destruction. Protection techniques, if employed, will mitigate engagement effects. SSM currently supports several two laser and three RF protection techniques. SSM allows the user to create and implement a variety of "what if" scenarios. Satellites can be placed in a variety of orbits. Threats can be placed anywhere on the Earth. Satellites and threats can be mixed and matched to examine possibilities. Protection techniques for a particular spacecraft can be turned on or off individually; and can be arranged in any order to simulate more complicated protection schemes. Results can be displayed as 2-D or 3-D visualizations, or as textual reports. In order to test SSM capabilities, the Ball team used it to model engagement scenarios for a space experiment scheduled for the 2011 time frame. SSM was created by Ball Aerospace & Technologies Corp. Systems Engineering Solutions in Albuquerque, New Mexico as an add-on module for the Satellite Tool Kit (STK). The current version of SSM (1.0) interfaces with STK through the Programmer's Library (STK/PL). Future versions of SSM will employ STK/Connect to provide the user access to STK functionality. The work is currently funded by the Air Force Research Laboratory, Space Vehicles directorate at Kirtland AFB, New Mexico, under contract number FA9453-06-C-0096.

[Approval of ISO/IEC 17025 and quality control of laboratory testing].

PubMed

Yamamoto, Shigeki; Asakura, Hiroshi; Machii, Kenji; Igimi, Shizunobu

2010-01-01

First section of Division of Biomedical Food Research, National Institute of Health Sciences (NIHS) was approved by ISO/IEC 17025 as a laboratory having an appropriate laboratory testing technique. NIHS is the first national laboratory approved by ISO/IEC 17025. NIHS has also been accepted the appropriate technique and facility for the BSL3 level pathogens by ISO/IEC 17025. NIHS is necessary to take an external audit almost every year. This approval is renewed every 4 years.

Laboratory Diagnosis of Tuberculosis in Resource-Poor Countries: Challenges and Opportunities

PubMed Central

Parsons, Linda M.; Somoskövi, Ákos; Gutierrez, Cristina; Lee, Evan; Paramasivan, C. N.; Abimiku, Alash'le; Spector, Steven; Roscigno, Giorgio; Nkengasong, John

2011-01-01

Summary: With an estimated 9.4 million new cases globally, tuberculosis (TB) continues to be a major public health concern. Eighty percent of all cases worldwide occur in 22 high-burden, mainly resource-poor settings. This devastating impact of tuberculosis on vulnerable populations is also driven by its deadly synergy with HIV. Therefore, building capacity and enhancing universal access to rapid and accurate laboratory diagnostics are necessary to control TB and HIV-TB coinfections in resource-limited countries. The present review describes several new and established methods as well as the issues and challenges associated with implementing quality tuberculosis laboratory services in such countries. Recently, the WHO has endorsed some of these novel methods, and they have been made available at discounted prices for procurement by the public health sector of high-burden countries. In addition, international and national laboratory partners and donors are currently evaluating other new diagnostics that will allow further and more rapid testing in point-of-care settings. While some techniques are simple, others have complex requirements, and therefore, it is important to carefully determine how to link these new tests and incorporate them within a country's national diagnostic algorithm. Finally, the successful implementation of these methods is dependent on key partnerships in the international laboratory community and ensuring that adequate quality assurance programs are inherent in each country's laboratory network. PMID:21482728

Evaluation of culture techniques and bacterial cultures from uroliths.

PubMed

Perry, Leigh A; Kass, Philip H; Johnson, Dee L; Ruby, Annette L; Shiraki, Ryoji; Westropp, Jodi L

2013-03-01

The association between urolithiasis and growth of bacteria in the urine or urolith has not been recently evaluated in the past 15 years, and the effects of antimicrobial administration on urolith cultures have not been reported. As well, laboratory techniques for urolith cultures have not been critically evaluated. The objectives of the current study were to 1) report bacterial isolates from uroliths and their association with signalment, urolith composition, antimicrobial use, and urine cultures and 2) evaluate laboratory techniques for urolith cultures. For the first objective, a retrospective search of bacterial isolates cultured from uroliths submitted to the laboratory as well as the signalment, urine culture results, and antimicrobial use were recorded. For the second objective, 50 urolith pairs were cultured by washing each urolith either 1or 4 times and culturing the core. Five hundred twenty canine and 168 feline uroliths were reviewed. Struvite-containing uroliths had an increased prevalence of a positive culture compared to nonstruvite-containing uroliths (P < 0.0001, odds ratio [OR] = 5.4), as did uroliths from female dogs (P < 0.0001, OR = 2.9). No significant difference between culture results and previous antimicrobial administration was found (P = 0.41). Eighteen percent of cases with negative urine cultures had positive urolith cultures. There was no significant difference in core culture results whether the urolith was washed 1 or 4 times (P = 0.07). Urolith culture outcome was not always influenced by previous antimicrobial administration, and bacterial culture of a urolith may not yield the same results as those obtained from the urine. The modified protocol, which requires less time and expense for urolith cultures, may be an acceptable alternative.

The Early Development of Satellite Characterization Capabilities at the Air Force Laboratories

NASA Astrophysics Data System (ADS)

Lambert, J.; Kissell, K.

This presentation overviews the development of optical Space Object Identification (SOI) techniques at the Air Force laboratories during the two-decade "pre-operational" period prior to 1980 when the Groundbased Electro-Optical Deep Space Surveillance (GEODSS) sensors were deployed. Beginning with the launch of Sputnik in 1957, the United States Air Force has actively pursued the development and application of optical sensor technology for the detection, tracking, and characterization of artificial satellites. Until the mid-1980s, these activities were primarily conducted within Air Force research and development laboratories which supplied data to the operational components on a contributing basis. This presentation traces the early evolution of the optical space surveillance technologies from the early experimental sensors that led to the current generation of operationally deployed and research systems. The contributions of the participating Air Force organizations and facilities will be reviewed with special emphasis on the development of technologies for the characterization of spacecraft using optical signatures and imagery. The presentation will include descriptions and photographs of the early facilities and instrumentation, and examples of the SOI collection and analysis techniques employed. In this early period, computer support was limited so all aspects of space surveillance relied heavily on manual interaction. Many military, government, educational, and contractor agencies supported the development of instrumentation and analysis techniques. This overview focuses mainly on the role played by Air Force System Command and Office of Aerospace Research, and the closely related activities at the Department of Defense Advanced Research Projects Agency. The omission of other agencies from this review reflects the limitations of this presentation, not the significance of their contributions.

A Technique Oriented Freshman Laboratory Program

ERIC Educational Resources Information Center

Palma, R. J., Sr.

1975-01-01

Describes a program built on the philosophy that laboratory exercises were to be exclusively reserved for those concepts which could not be taught more effectively by other pedagogical techniques. Presents faculty and student criticisms of the program. (GS)

Laboratory Study of Water Surface Roughness Generation by Wave-Current Interaction

NASA Technical Reports Server (NTRS)

Klinke, Jochen

2000-01-01

Within the framework of this project, the blocking of waves by inhomogeneous currents was studied. A laboratory experiment was conducted in collaboration with Steven R. Long at the linear wave tank of the NASA Air-Sea Interaction Facility, Wallops Island, VA during May 1999. Mechanically-generated waves were blocked approximately 3m upstream from the wave paddle by an opposing current. A false bottom was used to obtain a spatially varying flow field in the measurement section of the wave tank. We used an imaging slope gauge, which was mounted directly underneath the sloping section of the false tank bottom to observe the wave field. For a given current speed, the amplitude and the frequency of the waves was adjusted so that the blocking occurred within the observed footprint. Image sequences of up to 600 images at up 100 Hz sampling rate were recorded for an area of approximately 25cm x 25cm. Unlike previous measurements with wave wire gauges, the captured image sequences show the generation of the capillary waves at the blocking point and give detailed insight into the spatial and temporal evolution of the blocking process. The image data were used to study the wave-current interaction for currents from 5 to 25 cm/s and waves with frequencies between 1 and 3 Hz. First the images were calibrated with regard to size and slope. Then standard Fourier techniques as well the empirical mode decomposition method developed by Dr. Norden Huang and Dr. Steven R. Long were employed to quantify the wave number downshift from the gravity to the capillary regime.

The effect of plasma density and emitter geometry on space charge limits for field emitter array electron charge emission into a space plasma

NASA Astrophysics Data System (ADS)

Morris, Dave; Gilchrist, Brian; Gallimore, Alec

2001-02-01

Field Emitter Array Cathodes (FEACs) are a new technology being developed for several potential spacecraft electron emission and charge control applications. Instead of a single hot (i.e., high powered) emitter, or a gas dependant plasma contactor, FEAC systems consist of many (hundreds or thousands) of small (micron level) cathode/gate pairs printed on a semiconductor wafer that effect cold field emission at relatively low voltages. Each individual cathode emits only micro-amp level currents, but a functional array is capable of amp/cm2 current densities. It is hoped that thus FEAC offers the possibility of a relatively low-power, simple to integrate, and inexpensive technique for the high level of current emissions that are required for an electrodynamic tether (EDT) propulsion mission. Space charge limits are a significant concern for the EDT application. Vacuum chamber tests and PIC simulations are being performed at the University of Michigan Plasmadynamics and Electric Propulsion Laboratory and Space Physics Research Laboratory to determine the effect of plasma density and emitter geometry on space charge limitations. The results of this work and conclusions to date of how to best mitigate space charge limits will be presented. .

Teaching about genetic testing issues in the undergraduate classroom: a case study.

PubMed

Rogers, Jill Cellars; Taylor, Ann T S

2011-06-01

Educating undergraduates about current genetic testing and genomics can involve novel and creative teaching practices. The higher education literature describes numerous pedagogical approaches in the laboratory designed to engage science and liberal arts students. Often these experiences involve students analyzing their own genes for various polymorphisms, some of which are associated with disease states such as an increased risk for developing cancer. While the literature acknowledges possible ethical ramifications of such laboratory exercises, authors do not present recommendations or rubrics for evaluating whether or not the testing is, in fact, ethical. In response, we developed a laboratory investigation and discussion which allowed undergraduate science students to explore current DNA manipulation techniques to isolate their p53 gene, followed by a dialogue probing the ethical implications of examining their sample for various polymorphisms. Students never conducted genotyping on their samples because of ethical concerns, so the discussion served to replace actual genetic testing in the class. A basic scientist led the laboratory portion of the assignment. A genetic counselor facilitated the discussion, which centered around existing ethical guidelines for clinical genetic testing and possible challenges of human genotyping outside the medical setting. In their final papers, students demonstrated an understanding of the practice guidelines established by the genetics community and acknowledged the ethical considerations inherent in p53 genotyping. Given the burgeoning market for personalized medicine, teaching undergraduates about the psychosocial and ethical dimensions of human gene testing seems important and timely, and introduces an additional role genetic counselors can play in educating consumers about genomics.

Use of ``virtual'' field trips in teaching introductory geology

NASA Astrophysics Data System (ADS)

Hurst, Stephen D.

1998-08-01

We designed a series of case studies for Introductory Geology Laboratory courses using computer visualization techniques integrated with traditional laboratory materials. These consist of a comprehensive case study which requires three two-hour long laboratory periods to complete, and several shorter case studies requiring one or two, two-hour laboratory periods. Currently we have prototypes of the Yellowstone National Park, Hawaii volcanoes and the Mid-Atlantic Ridge case studies. The Yellowstone prototype can be used to learn about a wide variety of rocks and minerals, about geothermal activity and hydrology, about volcanic hazards and the hot-spot theory of plate tectonics. The Hawaiian exercise goes into more depth about volcanoes, volcanic rocks and their relationship to plate movements. The Mid-Atlantic Ridge project focuses on formation of new ocean crust and mineral-rich hydrothermal deposits at spreading centers. With new improvements in visualization technology that are making their way to personal computers, we are now closer to the ideal of a "virtual" field trip. We are currently making scenes of field areas in Hawaii and Yellowstone which allow the student to pan around the area and zoom in on interesting objects. Specific rocks in the scene will be able to be "picked up" and studied in three dimensions. This technology improves the ability of the computer to present a realistic simulation of the field area and allows the student to have more control over the presentation. This advanced interactive technology is intuitive to control, relatively cheap and easy to add to existing computer programs and documents.

Interspecific Cross-Mating Between Aedes aegypti and Aedes albopictus Laboratory Strains: Implication of Population Density on Mating Behaviors.

PubMed

Marcela, P; Hassan, A Abu; Hamdan, A; Dieng, H; Kumara, T K

2015-12-01

Mating behavior between Aedes aegypti and Ae. albopictus, established colony strains were examined under laboratory conditions (30-cm(3) screened cages) for 5 consecutive days. The effect of selected male densities (30, 20, 10) and female density (20) on the number of swarming, mating pairs, eggs produced, and inseminated females were evaluated. Male densities significantly increased swarming behavior, mating pairs, and egg production of heterospecific females, but female insemination was reduced. Aedes aegypti males mate more readily with heterospecific females than do Ae. albopictus males. The current study suggests that Ae. aegypti males were not species-specific in mating, and if released into the field as practiced in genetically modified mosquito techniques, they may mate with both Ae. aegypti and Ae. albopictus females, hence reducing populations of both species by producing infertile eggs.

Single-Shot Charge Readout Using a Cryogenic Heterojunction Bipolar Transistor Preamplifier Inline with a Silicon Single Electron Transistor at Millikelvin Temperatures

NASA Astrophysics Data System (ADS)

Curry, Matthew; England, Troy; Wendt, Joel; Pluym, Tammy; Lilly, Michael; Carr, Stephen; Carroll, Malcolm

Single-shot readout is a requirement for many implementations of quantum information processing. The single-shot readout fidelity is dependent on the signal-to-noise-ratio (SNR) and bandwidth of the readout detection technique. Several different approaches are being pursued to enhance read-out including RF-reflectometry, RF-transmission, parametric amplification, and transistor-based cryogenic preamplification. The transistor-based cryogenic preamplifier is attractive in part because of the reduced experimental complexity compared with the RF techniques. Here we present single-shot charge readout using a cryogenic Heterojunction-Bipolar-Transistor (HBT) inline with a silicon SET charge-sensor at millikelvin temperatures. For the relevant range of HBT DC-biasing, the current gain is 100 to 2000 and the power dissipation is 50 nW to 5 μW, with the microfabricated SET and discrete HBT in an integrated package mounted to the mixing chamber stage of a dilution refrigerator. We experimentally demonstrate a SNR of up to 10 with a bandwidth of 1 MHz, corresponding to a single-shot time-domain charge-sensitivity of approximately 10-4 e / √Hz. This measured charge-sensitivity is comparable to the values reported using the RF techniques. Sandia National Laboratories is a multi-program laboratory operated by Sandia Corporation, a Lockheed-Martin Company, for the U. S. Department of Energy under Contract No. DE-AC04-94AL85000.

Scoping study to expedite development of a field deployable and portable instrument for UF6 enrichment assay

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

Chan, George; Valentine, John D.; Russo, Richard E.

The primary objective of the present study is to identity the most promising, viable technologies that are likely to culminate in an expedited development of the next-generation, field-deployable instrument for providing rapid, accurate, and precise enrichment assay of uranium hexafluoride (UF6). UF6 is typically involved, and is arguably the most important uranium compound, in uranium enrichment processes. As the first line of defense against proliferation, accurate analytical techniques to determine the uranium isotopic distribution in UF6 are critical for materials verification, accounting, and safeguards at enrichment plants. As nuclear fuel cycle technology becomes more prevalent around the world, international nuclearmore » safeguards and interest in UF6 enrichment assay has been growing. At present, laboratory-based mass spectrometry (MS), which offers the highest attainable analytical accuracy and precision, is the technique of choice for the analysis of stable and long-lived isotopes. Currently, the International Atomic Energy Agency (IAEA) monitors the production of enriched UF6 at declared facilities by collecting a small amount (between 1 to 10 g) of gaseous UF6 into a sample bottle, which is then shipped under chain of custody to a central laboratory (IAEA’s Nuclear Materials Analysis Laboratory) for high-precision isotopic assay by MS. The logistics are cumbersome and new shipping regulations are making it more difficult to transport UF6. Furthermore, the analysis is costly, and results are not available for some time after sample collection. Hence, the IAEA is challenged to develop effective safeguards approaches at enrichment plants. In-field isotopic analysis of UF6 has the potential to substantially reduce the time, logistics and expense of sample handling. However, current laboratory-based MS techniques require too much infrastructure and operator expertise for field deployment and operation. As outlined in the IAEA Department of Safeguards Long-Term R&D Plan, 2012–2023, one of the IAEA long-term R&D needs is to “develop tools and techniques to enable timely, potentially real-time, detection of HEU (Highly Enriched Uranium) production in LEU (Lowly Enriched Uranium) enrichment facilities” (Milestone 5.2). Because it is common that the next generation of analytical instruments is driven by technologies that are either currently available or just now emerging, one reasonable and practical approach to project the next generation of chemical instrumentation is to track the recent trends and to extrapolate them. This study adopted a similar approach, and an extensive literature review on existing and emerging technologies for UF6 enrichment assay was performed. The competitive advantages and current limitations of different analytical techniques for in-field UF6 enrichment assay were then compared, and the main gaps between needs and capabilities for their field use were examined. Subsequently, based on these results, technologies for the next-generation field-deployable instrument for UF6 enrichment assay were recommended. The study was organized in a way that a suite of assessment metric was first identified. Criteria used in this evaluation are presented in Section 1 of this report, and the most important ones are described briefly in the next few paragraphs. Because one driving force for in-field UF6 enrichment assay is related to the demanding transportation regulation for gaseous UF6, Section 2 contains a review of solid sorbents that convert and immobilized gaseous UF6 to a solid state, which is regarded as more transportation friendly and is less regulated. Furthermore, candidate solid sorbents, which show promise in mating with existing and emerging assay technologies, also factor into technology recommendations. Extensive literature reviews on existing and emerging technologies for UF6 enrichment assay, covering their scientific principles, instrument options, and current limitations are detailed in Sections 3 and 4, respectively. In Section 5, the technological gaps as well as start-of-the-art and commercial off-the-shelf components that can be adopted to expedite the development of a fieldable or portable UF6 enrichment-assay instrument are identified and discussed. Finally, based on the results of the review, requirements and recommendations for developing the next-generation field-deployable instrument for UF6 enrichment assay are presented in Section 6.« less

The Language Laboratory.

ERIC Educational Resources Information Center

Hughes, John P.

Concepts pertaining to the language laboratory are clarified for the layman unfamiliar with recent educational developments in foreign language instruction. These include discussion of: (1) language laboratory components and functions, (2) techniques used in the laboratory, (3) new linguistic methods, (4) laboratory exercises, (5) traditional…

Internal kinematics and dynamical models of dwarf spheroidal galaxies around the Milky Way

NASA Astrophysics Data System (ADS)

Battaglia, Giuseppina; Helmi, Amina; Breddels, Maarten

2013-09-01

We review our current understanding of the internal dynamical properties of the dwarf spheroidal galaxies surrounding the Milky Way. These are the most dark matter dominated galaxies, and as such may be considered ideal laboratories to test the current concordance cosmological model, and in particular provide constraints on the nature of the dominant form of dark matter. We discuss the latest observations of the kinematics of stars in these systems, and how these may be used to derive their mass distribution. We tour through the various dynamical techniques used, with emphasis on the complementarity and limitations, and discuss what the results imply also in the context of cosmological models. Finally we provide an outlook on exciting developments in this field.

[The current clinical laboratory in the public health system and medical science: a lecture].

PubMed

Men'shikov, V V

2011-11-01

The analytic and diagnostic possibilities of current clinical laboratories are discussed. The roles of laboratory information in the formation of new research directions are characterized. The proposals on the development of economic basics of the development of laboratory medicine.

Laboratory techniques and rhythmometry

NASA Technical Reports Server (NTRS)

Halberg, F.

1973-01-01

Some of the procedures used for the analysis of rhythms are illustrated, notably as these apply to current medical and biological practice. For a quantitative approach to medical and broader socio-ecologic goals, the chronobiologist gathers numerical objective reference standards for rhythmic biophysical, biochemical, and behavioral variables. These biological reference standards can be derived by specialized computer analyses of largely self-measured (until eventually automatically recorded) time series (autorhythmometry). Objective numerical values for individual and population parameters of reproductive cycles can be obtained concomitantly with characteristics of about-yearly (circannual), about-daily (circadian) and other rhythms.

Characterization of Stereo Vision Performance for Roving at the Lunar Poles

NASA Technical Reports Server (NTRS)

Wong, Uland; Nefian, Ara; Edwards, Larry; Furlong, Michael; Bouyssounouse, Xavier; To, Vinh; Deans, Matthew; Cannon, Howard; Fong, Terry

2016-01-01

Surface rover operations at the polar regions of airless bodies, particularly the Moon, are of particular interest to future NASA science missions such as Resource Prospector (RP). Polar optical conditions present challenges to conventional imaging techniques, with repercussions to driving, safeguarding and science. High dynamic range, long cast shadows, opposition and white out conditions are all significant factors in appearance. RP is currently undertaking an effort to characterize stereo vision performance in polar conditions through physical laboratory experimentation with regolith simulants, obstacle distributions and oblique lighting.

Current approach in the diagnosis and management of posterior uveitis

PubMed Central

Sudharshan, S; Ganesh, Sudha K; Biswas, Jyotrimay

2010-01-01

Posterior uveitic entities are varied entities that are infective or non-infective in etiology. They can affect the adjacent structures such as the retina, vitreous, optic nerve head and retinal blood vessels. Thorough clinical evaluation gives a clue to the diagnosis while ancillary investigations and laboratory tests assist in confirming the diagnosis. Newer evolving techniques in the investigations and management have increased the diagnostic yield. In case of diagnostic dilemma, intraocular fluid evaluation for polymerase chain testing for the genome and antibody testing against the causative agent provide greater diagnostic ability. PMID:20029144

Current Status of the Polyamine Research Field

PubMed Central

Pegg, Anthony E.; Casero, Robert A.

2013-01-01

This chapter provides an overview of the polyamine field and introduces the 32 other chapters that make up this volume. These chapters provide a wide range of methods, advice, and background relevant to studies of the function of polyamines, the regulation of their content, their role in disease, and the therapeutic potential of drugs targeting polyamine content and function. The methodology provided in this new volume will enable laboratories already working in this area to expand their experimental techniques and facilitate the entry of additional workers into this rapidly expanding field. PMID:21318864

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

Lucia, M., E-mail: mlucia@pppl.gov; Kaita, R.; Majeski, R.

The Materials Analysis and Particle Probe (MAPP) is a compact in vacuo surface science diagnostic, designed to provide in situ surface characterization of plasma facing components in a tokamak environment. MAPP has been implemented for operation on the Lithium Tokamak Experiment at Princeton Plasma Physics Laboratory (PPPL), where all control and analysis systems are currently under development for full remote operation. Control systems include vacuum management, instrument power, and translational/rotational probe drive. Analysis systems include onboard Langmuir probes and all components required for x-ray photoelectron spectroscopy, low-energy ion scattering spectroscopy, direct recoil spectroscopy, and thermal desorption spectroscopy surface analysis techniques.

Standardization of chemical analytical techniques for pyrolysis bio-oil: history, challenges, and current status of methods

DOE PAGES

Ferrell, Jack R.; Olarte, Mariefel V.; Christensen, Earl D.; ...

2016-07-05

Here, we discuss the standardization of analytical techniques for pyrolysis bio-oils, including the current status of methods, and our opinions on future directions. First, the history of past standardization efforts is summarized, and both successful and unsuccessful validation of analytical techniques highlighted. The majority of analytical standardization studies to-date has tested only physical characterization techniques. In this paper, we present results from an international round robin on the validation of chemical characterization techniques for bio-oils. Techniques tested included acid number, carbonyl titrations using two different methods (one at room temperature and one at 80 °C), 31P NMR for determination ofmore » hydroxyl groups, and a quantitative gas chromatography–mass spectrometry (GC-MS) method. Both carbonyl titration and acid number methods have yielded acceptable inter-laboratory variabilities. 31P NMR produced acceptable results for aliphatic and phenolic hydroxyl groups, but not for carboxylic hydroxyl groups. As shown in previous round robins, GC-MS results were more variable. Reliable chemical characterization of bio-oils will enable upgrading research and allow for detailed comparisons of bio-oils produced at different facilities. Reliable analytics are also needed to enable an emerging bioenergy industry, as processing facilities often have different analytical needs and capabilities than research facilities. We feel that correlations in reliable characterizations of bio-oils will help strike a balance between research and industry, and will ultimately help to -determine metrics for bio-oil quality. Lastly, the standardization of additional analytical methods is needed, particularly for upgraded bio-oils.« less

Single-particle imaging for biosensor applications

NASA Astrophysics Data System (ADS)

Yorulmaz, Mustafa; Isil, Cagatay; Seymour, Elif; Yurdakul, Celalettin; Solmaz, Berkan; Koc, Aykut; Ünlü, M. Selim

2017-10-01

Current state-of-the-art technology for in-vitro diagnostics employ laboratory tests such as ELISA that consists of a multi-step test procedure and give results in analog format. Results of these tests are interpreted by the color change in a set of diluted samples in a multi-well plate. However, detection of the minute changes in the color poses challenges and can lead to false interpretations. Instead, a technique that allows individual counting of specific binding events would be useful to overcome such challenges. Digital imaging has been applied recently for diagnostics applications. SPR is one of the techniques allowing quantitative measurements. However, the limit of detection in this technique is on the order of nM. The current required detection limit, which is already achieved with the analog techniques, is around pM. Optical techniques that are simple to implement and can offer better sensitivities have great potential to be used in medical diagnostics. Interference Microscopy is one of the tools that have been investigated over years in optics field. More of the studies have been performed in confocal geometry and each individual nanoparticle was observed separately. Here, we achieve wide-field imaging of individual nanoparticles in a large field-of-view ( 166 μm × 250 μm) on a micro-array based sensor chip in fraction of a second. We tested the sensitivity of our technique on dielectric nanoparticles because they exhibit optical properties similar to viruses and cells. We can detect non-resonant dielectric polystyrene nanoparticles of 100 nm. Moreover, we perform post-processing applications to further enhance visibility.

Standardization of chemical analytical techniques for pyrolysis bio-oil: history, challenges, and current status of methods

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

Ferrell, Jack R.; Olarte, Mariefel V.; Christensen, Earl D.

Here, we discuss the standardization of analytical techniques for pyrolysis bio-oils, including the current status of methods, and our opinions on future directions. First, the history of past standardization efforts is summarized, and both successful and unsuccessful validation of analytical techniques highlighted. The majority of analytical standardization studies to-date has tested only physical characterization techniques. In this paper, we present results from an international round robin on the validation of chemical characterization techniques for bio-oils. Techniques tested included acid number, carbonyl titrations using two different methods (one at room temperature and one at 80 °C), 31P NMR for determination ofmore » hydroxyl groups, and a quantitative gas chromatography–mass spectrometry (GC-MS) method. Both carbonyl titration and acid number methods have yielded acceptable inter-laboratory variabilities. 31P NMR produced acceptable results for aliphatic and phenolic hydroxyl groups, but not for carboxylic hydroxyl groups. As shown in previous round robins, GC-MS results were more variable. Reliable chemical characterization of bio-oils will enable upgrading research and allow for detailed comparisons of bio-oils produced at different facilities. Reliable analytics are also needed to enable an emerging bioenergy industry, as processing facilities often have different analytical needs and capabilities than research facilities. We feel that correlations in reliable characterizations of bio-oils will help strike a balance between research and industry, and will ultimately help to -determine metrics for bio-oil quality. Lastly, the standardization of additional analytical methods is needed, particularly for upgraded bio-oils.« less

Demonstrations of Extraterrestrial Life Detection Techniques in the High School Biology Laboratory

ERIC Educational Resources Information Center

Saltinski, Ronald

1969-01-01

Discusses the experimental procedures and equipment for exobiology projects at the high school level. An interdisciplinary approach involving electronic equipment and micro-biological laboratory techniques is used. Photographs and diagrams of equipment are included. Bibliography. (LC)

Guidelines for safe work practices in human and animal medical diagnostic laboratories. Recommendations of a CDC-convened, Biosafety Blue Ribbon Panel.

PubMed

Miller, J Michael; Astles, Rex; Baszler, Timothy; Chapin, Kimberle; Carey, Roberta; Garcia, Lynne; Gray, Larry; Larone, Davise; Pentella, Michael; Pollock, Anne; Shapiro, Daniel S; Weirich, Elizabeth; Wiedbrauk, Danny

2012-01-06

Prevention of injuries and occupational infections in U.S. laboratories has been a concern for many years. CDC and the National Institutes of Health addressed the topic in their publication Biosafety in Microbiological and Biomedical Laboratories, now in its 5th edition (BMBL-5). BMBL-5, however, was not designed to address the day-to-day operations of diagnostic laboratories in human and animal medicine. In 2008, CDC convened a Blue Ribbon Panel of laboratory representatives from a variety of agencies, laboratory organizations, and facilities to review laboratory biosafety in diagnostic laboratories. The members of this panel recommended that biosafety guidelines be developed to address the unique operational needs of the diagnostic laboratory community and that they be science based and made available broadly. These guidelines promote a culture of safety and include recommendations that supplement BMBL-5 by addressing the unique needs of the diagnostic laboratory. They are not requirements but recommendations that represent current science and sound judgment that can foster a safe working environment for all laboratorians. Throughout these guidelines, quality laboratory science is reinforced by a common-sense approach to biosafety in day-to-day activities. Because many of the same diagnostic techniques are used in human and animal diagnostic laboratories, the text is presented with this in mind. All functions of the human and animal diagnostic laboratory--microbiology, chemistry, hematology, and pathology with autopsy and necropsy guidance--are addressed. A specific section for veterinary diagnostic laboratories addresses the veterinary issues not shared by other human laboratory departments. Recommendations for all laboratories include use of Class IIA2 biological safety cabinets that are inspected annually; frequent hand washing; use of appropriate disinfectants, including 1:10 dilutions of household bleach; dependence on risk assessments for many activities; development of written safety protocols that address the risks of chemicals in the laboratory; the need for negative airflow into the laboratory; areas of the laboratory in which use of gloves is optional or is recommended; and the national need for a central site for surveillance and nonpunitive reporting of laboratory incidents/exposures, injuries, and infections.

Polarization Lidar for Shallow Water Supraglacial Lake Depth Measurement

NASA Astrophysics Data System (ADS)

Mitchell, S.; Adler, J.; Thayer, J. P.; Hayman, M.

2010-12-01

A bathymetric, polarization lidar system transmitting at 532 nanometers and using a single photomultiplier tube is developed for applications of shallow water depth measurement, in particular those often found in supraglacial lakes of the ablation zone on the Greenland Ice Sheet. The technique exploits polarization attributes of the probed water body to isolate surface and floor returns, enabling constant fraction detection schemes to determine depth. The minimum resolvable water depth is no longer dictated by the system’s laser or detector pulse width and can achieve better than an order of magnitude improvement over current water depth determination techniques. In laboratory tests, a Nd:YAG microchip laser coupled with polarization optics, a photomultiplier tube, a constant fraction discriminator and a time to digital converter are used to target various water depths, using ice as the floor to simulate a supraglacial lake. Measurement of 1 centimeter water depths with an uncertainty of ±3 millimeters are demonstrated using the technique. This novel technique enables new approaches to designing laser bathymetry systems for shallow depth determination from remote platforms while not compromising deep water depth measurement, and will support comprehensive hydrodynamic studies of supraglacial lakes. Additionally, the compact size and low weight (<15 kg) of the field system currently in development presents opportunities for use in small unmanned aircraft systems (UAS) for large areal surveys of the ablation zone.

The Development of Models for Carbon Dioxide Reduction Technologies for Spacecraft Air Revitalization

NASA Technical Reports Server (NTRS)

Swickrath, Michael J.; Anderson, Molly

2011-01-01

Through the respiration process, humans consume oxygen (O2) while producing carbon dioxide (CO2) and water (H2O) as byproducts. For long term space exploration, CO2 concentration in the atmosphere must be managed to prevent hypercapnia. Moreover, CO2 can be used as a source of oxygen through chemical reduction serving to minimize the amount of oxygen required at launch. Reduction can be achieved through a number of techniques. The National Aeronautics and Space Administration (NASA) is currently exploring the Sabatier reaction, the Bosch reaction, and co-electrolysis of CO2 and H2O for this process. Proof-of-concept experiments and prototype units for all three processes have proven capable of returning useful commodities for space exploration. While all three techniques have demonstrated the capacity to reduce CO2 in the laboratory, there is interest in understanding how all three techniques would perform at a system-level within a spacecraft. Consequently, there is an impetus to develop predictive models for these processes that can be readily re-scaled and integrated into larger system models. Such analysis tools provide the ability to evaluate each technique on a comparable basis with respect to processing rates. This manuscript describes the current models for the carbon dioxide reduction processes under parallel developmental e orts. Comparison to experimental data is provided were available for veri cation purposes.

Evaluation of direct and indirect additive manufacture of maxillofacial prostheses.

PubMed

Eggbeer, Dominic; Bibb, Richard; Evans, Peter; Ji, Lu

2012-09-01

The efficacy of computer-aided technologies in the design and manufacture of maxillofacial prostheses has not been fully proven. This paper presents research into the evaluation of direct and indirect additive manufacture of a maxillofacial prosthesis against conventional laboratory-based techniques. An implant/magnet-retained nasal prosthesis case from a UK maxillofacial unit was selected as a case study. A benchmark prosthesis was fabricated using conventional laboratory-based techniques for comparison against additive manufactured prostheses. For the computer-aided workflow, photogrammetry, computer-aided design and additive manufacture (AM) methods were evaluated in direct prosthesis body fabrication and indirect production using an additively manufactured mould. Qualitative analysis of position, shape, colour and edge quality was undertaken. Mechanical testing to ISO standards was also used to compare the silicone rubber used in the conventional prosthesis with the AM material. Critical evaluation has shown that utilising a computer-aided work-flow can produce a prosthesis body that is comparable to that produced using existing best practice. Technical limitations currently prevent the direct fabrication method demonstrated in this paper from being clinically viable. This research helps prosthesis providers understand the application of a computer-aided approach and guides technology developers and researchers to address the limitations identified.

Diode lasers: From laboratory to industry

NASA Astrophysics Data System (ADS)

Nasim, Hira; Jamil, Yasir

2014-03-01

The invention of first laser in 1960 triggered the discovery of several new families of lasers. A rich interplay of different lasing materials resulted in a far better understanding of the phenomena particularly linked with atomic and molecular spectroscopy. Diode lasers have gone through tremendous developments on the forefront of applied physics that have shown novel ways to the researchers. Some interesting attributes of the diode lasers like cost effectiveness, miniature size, high reliability and relative simplicity of use make them good candidates for utilization in various practical applications. Diode lasers are being used by a variety of professionals and in several spectroscopic techniques covering many areas of pure and applied sciences. Diode lasers have revolutionized many fields like optical communication industry, medical science, trace gas monitoring, studies related to biology, analytical chemistry including elemental analysis, war fare studies etc. In this paper the diode laser based technologies and measurement techniques ranging from laboratory research to automated field and industry have been reviewed. The application specific developments of diode lasers and various methods of their utilization particularly during the last decade are discussed comprehensively. A detailed snapshot of the current state of the art diode laser applications is given along with a detailed discussion on the upcoming challenges.

Digital map databases in support of avionic display systems

NASA Astrophysics Data System (ADS)

Trenchard, Michael E.; Lohrenz, Maura C.; Rosche, Henry, III; Wischow, Perry B.

1991-08-01

The emergence of computerized mission planning systems (MPS) and airborne digital moving map systems (DMS) has necessitated the development of a global database of raster aeronautical chart data specifically designed for input to these systems. The Naval Oceanographic and Atmospheric Research Laboratory''s (NOARL) Map Data Formatting Facility (MDFF) is presently dedicated to supporting these avionic display systems with the development of the Compressed Aeronautical Chart (CAC) database on Compact Disk Read Only Memory (CDROM) optical discs. The MDFF is also developing a series of aircraft-specific Write-Once Read Many (WORM) optical discs. NOARL has initiated a comprehensive research program aimed at improving the pilots'' moving map displays current research efforts include the development of an alternate image compression technique and generation of a standard set of color palettes. The CAC database will provide digital aeronautical chart data in six different scales. CAC is derived from the Defense Mapping Agency''s (DMA) Equal Arc-second (ARC) Digitized Raster Graphics (ADRG) a series of scanned aeronautical charts. NOARL processes ADRG to tailor the chart image resolution to that of the DMS display while reducing storage requirements through image compression techniques. CAC is being distributed by DMA as a library of CDROMs.

Curation of Samples from Mars

NASA Astrophysics Data System (ADS)

Lindstrom, D.; Allen, C.

One of the strong scientific reasons for returning samples from Mars is to search for evidence of current or past life in the samples. Because of the remote possibility that the samples may contain life forms that are hazardous to the terrestrial biosphere, the National Research Council has recommended that all samples returned from Mars be kept under strict biological containment until tests show that they can safely be released to other laboratories. It is possible that Mars samples may contain only scarce or subtle traces of life or prebiotic chemistry that could readily be overwhelmed by terrestrial contamination. Thus, the facilities used to contain, process, and analyze samples from Mars must have a combination of high-level biocontainment and organic / inorganic chemical cleanliness that is unprecedented. We have been conducting feasibility studies and developing designs for a facility that would be at least as capable as current maximum containment BSL-4 (BioSafety Level 4) laboratories, while simultaneously maintaining cleanliness levels exceeding those of the cleanest electronics manufacturing labs. Unique requirements for the processing of Mars samples have inspired a program to develop handling techniques that are much more precise and reliable than the approach (currently used for lunar samples) of employing gloved human hands in nitrogen-filled gloveboxes. Individual samples from Mars are expected to be much smaller than lunar samples, the total mass of samples returned by each mission being 0.5- 1 kg, compared with many tens of kg of lunar samples returned by each of the six Apollo missions. Smaller samp les require much more of the processing to be done under microscopic observation. In addition, the requirements for cleanliness and high-level containment would be difficult to satisfy while using traditional gloveboxes. JSC has constructed a laboratory to test concepts and technologies important to future sample curation. The Advanced Curation Laboratory includes a new- generation glovebox equipped with a robotic arm to evaluate the usability of robotic and teleoperated systems to perform curatorial tasks. The laboratory also contains equipment for precision cleaning and the measurement of trace organic contamination.

Introducing Mammalian Cell Culture and Cell Viability Techniques in the Undergraduate Biology Laboratory.

PubMed

Bowey-Dellinger, Kristen; Dixon, Luke; Ackerman, Kristin; Vigueira, Cynthia; Suh, Yewseok K; Lyda, Todd; Sapp, Kelli; Grider, Michael; Crater, Dinene; Russell, Travis; Elias, Michael; Coffield, V McNeil; Segarra, Verónica A

2017-01-01

Undergraduate students learn about mammalian cell culture applications in introductory biology courses. However, laboratory modules are rarely designed to provide hands-on experience with mammalian cells or teach cell culture techniques, such as trypsinization and cell counting. Students are more likely to learn about cell culture using bacteria or yeast, as they are typically easier to grow, culture, and manipulate given the equipment, tools, and environment of most undergraduate biology laboratories. In contrast, the utilization of mammalian cells requires a dedicated biological safety cabinet and rigorous antiseptic techniques. For this reason, we have devised a laboratory module and method herein that familiarizes students with common cell culture procedures, without the use of a sterile hood or large cell culture facility. Students design and perform a time-efficient inquiry-based cell viability experiment using HeLa cells and tools that are readily available in an undergraduate biology laboratory. Students will become familiar with common techniques such as trypsinizing cells, cell counting with a hemocytometer, performing serial dilutions, and determining cell viability using trypan blue dye. Additionally, students will work with graphing software to analyze their data and think critically about the mechanism of death on a cellular level. Two different adaptations of this inquiry-based lab are presented-one for non-biology majors and one for biology majors. Overall, these laboratories aim to expose students to mammalian cell culture and basic techniques and help them to conceptualize their application in scientific research.

Introducing Mammalian Cell Culture and Cell Viability Techniques in the Undergraduate Biology Laboratory †

PubMed Central

Bowey-Dellinger, Kristen; Dixon, Luke; Ackerman, Kristin; Vigueira, Cynthia; Suh, Yewseok K.; Lyda, Todd; Sapp, Kelli; Grider, Michael; Crater, Dinene; Russell, Travis; Elias, Michael; Coffield, V. McNeil; Segarra, Verónica A.

2017-01-01

Undergraduate students learn about mammalian cell culture applications in introductory biology courses. However, laboratory modules are rarely designed to provide hands-on experience with mammalian cells or teach cell culture techniques, such as trypsinization and cell counting. Students are more likely to learn about cell culture using bacteria or yeast, as they are typically easier to grow, culture, and manipulate given the equipment, tools, and environment of most undergraduate biology laboratories. In contrast, the utilization of mammalian cells requires a dedicated biological safety cabinet and rigorous antiseptic techniques. For this reason, we have devised a laboratory module and method herein that familiarizes students with common cell culture procedures, without the use of a sterile hood or large cell culture facility. Students design and perform a time-efficient inquiry-based cell viability experiment using HeLa cells and tools that are readily available in an undergraduate biology laboratory. Students will become familiar with common techniques such as trypsinizing cells, cell counting with a hemocytometer, performing serial dilutions, and determining cell viability using trypan blue dye. Additionally, students will work with graphing software to analyze their data and think critically about the mechanism of death on a cellular level. Two different adaptations of this inquiry-based lab are presented—one for non-biology majors and one for biology majors. Overall, these laboratories aim to expose students to mammalian cell culture and basic techniques and help them to conceptualize their application in scientific research. PMID:28861134

Reduction of multi-dimensional laboratory data to a two-dimensional plot: a novel technique for the identification of laboratory error.

PubMed

Kazmierczak, Steven C; Leen, Todd K; Erdogmus, Deniz; Carreira-Perpinan, Miguel A

2007-01-01

The clinical laboratory generates large amounts of patient-specific data. Detection of errors that arise during pre-analytical, analytical, and post-analytical processes is difficult. We performed a pilot study, utilizing a multidimensional data reduction technique, to assess the utility of this method for identifying errors in laboratory data. We evaluated 13,670 individual patient records collected over a 2-month period from hospital inpatients and outpatients. We utilized those patient records that contained a complete set of 14 different biochemical analytes. We used two-dimensional generative topographic mapping to project the 14-dimensional record to a two-dimensional space. The use of a two-dimensional generative topographic mapping technique to plot multi-analyte patient data as a two-dimensional graph allows for the rapid identification of potentially anomalous data. Although we performed a retrospective analysis, this technique has the benefit of being able to assess laboratory-generated data in real time, allowing for the rapid identification and correction of anomalous data before they are released to the physician. In addition, serial laboratory multi-analyte data for an individual patient can also be plotted as a two-dimensional plot. This tool might also be useful for assessing patient wellbeing and prognosis.

Locating Stardust-like Particles in Aerogel Using X-Ray Techniques

NASA Technical Reports Server (NTRS)

Jurewicz, A. J. G.; Jones, S. M.; Tsapin, A.; Mih, D. T.; Connolly, H. C., Jr.; Graham, G. A.

2003-01-01

Silica aerogel is the material that the spacecraft STARDUST is using to collect interstellar and cometary silicates. Anticipating the return of the samples to earth in January of 2006, MANY individual investigators and, especially, the investigators in NASA's SRLIDAP program are studying means of both in situ analysis of particles, as well as particle extraction. To help individual PI's with extraction of particles from aerogel in their own laboratories, we are exploring the use of standard laboratory x-ray equipment and commercial techniques for precisely locating specific particles in aerogel. We approached the evaluation of commercial x-ray techniques as follows. First, we determined the most appropriate detector for use with aerogel and particulates. Then, we compared and contrasted techniques useful for university laboratories.

Diagnostic tests for Niemann-Pick disease type C (NP-C): A critical review.

PubMed

Vanier, Marie T; Gissen, Paul; Bauer, Peter; Coll, Maria J; Burlina, Alberto; Hendriksz, Christian J; Latour, Philippe; Goizet, Cyril; Welford, Richard W D; Marquardt, Thorsten; Kolb, Stefan A

2016-08-01

Niemann-Pick disease type C (NP-C) is a neurovisceral lysosomal cholesterol trafficking and lipid storage disorder caused by mutations in one of the two genes, NPC1 or NPC2. Diagnosis has often been a difficult task, due to the wide range in age of onset of NP-C and clinical presentation of the disease, combined with the complexity of the cell biology (filipin) laboratory testing, even in combination with genetic testing. This has led to substantial delays in diagnosis, largely depending on the access to specialist centres and the level of knowledge about NP-C of the physician in the area. In recent years, advances in mass spectrometry has allowed identification of several sensitive plasma biomarkers elevated in NP-C (e.g. cholestane-3β,5α,6β-triol, lysosphingomyelin isoforms and bile acid metabolites), which, together with the concomitant progress in molecular genetic technology, have greatly impacted the strategy of laboratory testing. Specificity of the biomarkers is currently under investigation and other pathologies are being found to also result in elevations. Molecular genetic testing also has its limitations, notably with unidentified mutations and the classification of new variants. This review is intended to increase awareness on the currently available approaches to laboratory diagnosis of NP-C, to provide an up to date, comprehensive and critical evaluation of the various techniques (cell biology, biochemical biomarkers and molecular genetics), and to briefly discuss ongoing/future developments. The use of current tests in proper combination enables a rapid and correct diagnosis in a large majority of cases. However, even with recent progress, definitive diagnosis remains challenging in some patients, for whom combined genetic/biochemical/cytochemical markers do not provide a clear answer. Expertise and reference laboratories thus remain essential, and further work is still required to fulfill unmet needs. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Human System Simulation in Support of Human Performance Technical Basis at NPPs

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

David Gertman; Katya Le Blanc; alan mecham

2010-06-01

This paper focuses on strategies and progress toward establishing the Idaho National Laboratory’s (INL’s) Human Systems Simulator Laboratory at the Center for Advanced Energy Studies (CAES), a consortium of Idaho State Universities. The INL is one of the National Laboratories of the US Department of Energy. One of the first planned applications for the Human Systems Simulator Laboratory is implementation of a dynamic nuclear power plant simulation (NPP) where studies of operator workload, situation awareness, performance and preference will be carried out in simulated control rooms including nuclear power plant control rooms. Simulation offers a means by which to reviewmore » operational concepts, improve design practices and provide a technical basis for licensing decisions. In preparation for the next generation power plant and current government and industry efforts in support of light water reactor sustainability, human operators will be attached to a suite of physiological measurement instruments and, in combination with traditional Human Factors Measurement techniques, carry out control room tasks in simulated advanced digital and hybrid analog/digital control rooms. The current focus of the Human Systems Simulator Laboratory is building core competence in quantitative and qualitative measurements of situation awareness and workload. Of particular interest is whether introduction of digital systems including automated procedures has the potential to reduce workload and enhance safety while improving situation awareness or whether workload is merely shifted and situation awareness is modified in yet to be determined ways. Data analysis is carried out by engineers and scientists and includes measures of the physical and neurological correlates of human performance. The current approach supports a user-centered design philosophy (see ISO 13407 “Human Centered Design Process for Interactive Systems, 1999) wherein the context for task performance along with the requirements of the end-user are taken into account during the design process and the validity of design is determined through testing of real end users« less

An assessment of contemporary atomic spectroscopic techniques for the determination of lead in blood and urine matrices

NASA Astrophysics Data System (ADS)

Parsons, Patrick J.; Geraghty, Ciaran; Verostek, Mary Frances

2001-09-01

The preparation and validation of a number of clinical reference materials for the determination of lead in blood and urine is described. Four candidate blood lead reference materials (Lots, 047-050), and four candidate urine lead reference materials (Lots, 034, 035, 037 and 038), containing physiologically-bound lead at clinically relevant concentrations, were circulated to up to 21 selected laboratories specializing in this analysis. Results from two interlaboratory studies were used to establish certified values and uncertainty estimates for these reference materials. These data also provided an assessment of current laboratory techniques for the measurement of lead in blood and urine. For the blood lead measurements, four laboratories used electrothermal atomization AAS, three used anodic stripping voltammetry and one used both ETAAS and ICP-MS. For the urine lead measurements, 11 laboratories used ETAAS (most with Zeeman background correction) and 10 used ICP-MS. Certified blood lead concentrations, ±S.D., ranged from 5.9±0.4 μg/dl (0.28±0.02 μmol/l) to 76.0±2.2 μg/dl (3.67±0.11 μmol/l) and urine lead concentrations ranged from 98±5 μg/l (0.47±0.02 μmol/l) to 641±36 μg/l (3.09±0.17 μmol/l). The highest concentration blood lead material was subjected to multiple analyses using ETAAS over an extended time period. The data indicate that more stringent internal quality control practices are necessary to improve long-term precision. While the certification of blood lead materials was accomplished in a manner consistent with established practices, the urine lead materials proved more troublesome, particularly at concentrations above 600 μg/l (2.90 μmol/l).

Characterization and measurement of natural gas trace constituents. Volume 1. Arsenic. Final report, June 1989-October 1993

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

Chao, S.S.; Attari, A.

1995-01-01

The discovery of arsenic compounds, as alkylarsines, in natural gas prompted this research program to develop reliable measurement techniques needed to assess the efficiency of removal processes for these environmentally sensitive substances. These techniques include sampling, speciation, quantitation and on-line instrumental methods for monitoring the total arsenic concentration. The current program has yielded many products, including calibration standards, arsenic-specific sorbents, sensitive analytical methods and instrumentation. Four laboratory analytical methods have been developed and successfully employed for arsenic determination in natural gas. These methods use GC-AED and GC-MS instruments to speciate alkylarsines, and peroxydisulfate extraction with FIAS, special carbon sorbent withmore » XRF and an IGT developed sorbent with GFAA for total arsenic measurement.« less

Diagnostic experiments at a 3 MeV test stand at Rutherford Appleton Laboratory (United Kingdom).

PubMed

Gabor, C; Faircloth, D C; Lee, D A; Lawrie, S R; Letchford, A P; Pozimski, J K

2010-02-01

A front end is currently under construction consisting of a H(-) Penning ion source (65 keV, 60 mA), low energy beam transport (LEBT), and radio frequency quadrupole (3 MeV output energy) with a medium energy beam transport suitable for high power proton applications. Diagnostics can be divided either in destructive techniques such as beam profile monitor, pepperpot, slit-slit emittance scanner (preferably used during commissioning) or nondestructive, permanently installed devices such as photodetachment-based techniques. Another way to determine beam distributions is a scintillator with charge-coupled device camera. First experiments have been performed to control the beam injection into the LEBT. The influence of beam parameters such as particle energy and space-charge compensation on the two-dimensional distribution and profiles will be presented.

Film/chemistry selection for the earth resources technology satellite /ERTS/ ground data handling system

NASA Technical Reports Server (NTRS)

Shaffer, R. M.

1973-01-01

A detailed description is given of the methods of choose the duplication film and chemistry currently used in the NASA-ERTS Ground Data Handling System. The major ERTS photographic duplication goals are given as background information to justify the specifications for the desirable film/chemistry combination. Once these specifications were defined, a quantitative evaluation program was designed and implemented to determine if any recommended combinations could meet the ERTS laboratory specifications. The specifications include tone reproduction, granularity, MTF and cosmetic effects. A complete description of the techniques used to measure the test response variables is given. It is anticipated that similar quantitative techniques could be used on other programs to determine the optimum film/chemistry consistent with the engineering goals of the program.

Isolation of Shikimic Acid from Star Aniseed

ERIC Educational Resources Information Center

Payne, Richard; Edmonds, Michael

2005-01-01

A new undergraduate laboratory experiment suitable for demonstrating some key techniques used in natural products chemistry is described. A laboratory experiment is developed which in the process of extracting shikimic acid from star aniseed exposes students to a number of important experimental techniques.

Closing the brain-to-brain loop in laboratory testing.

PubMed

Plebani, Mario; Lippi, Giuseppe

2011-07-01

Abstract The delivery of laboratory services has been described 40 years ago and defined with the foremost concept of "brain-to-brain turnaround time loop". This concept consists of several processes, including the final step which is the action undertaken on the patient based on laboratory information. Unfortunately, the need for systematic feedback to improve the value of laboratory services has been poorly understood and, even more risky, poorly applied in daily laboratory practice. Currently, major problems arise from the unavailability of consensually accepted quality specifications for the extra-analytical phase of laboratory testing. This, in turn, does not allow clinical laboratories to calculate a budget for the "patient-related total error". The definition and use of the term "total error" refers only to the analytical phase, and should be better defined as "total analytical error" to avoid any confusion and misinterpretation. According to the hierarchical approach to classify strategies to set analytical quality specifications, the "assessment of the effect of analytical performance on specific clinical decision-making" is comprehensively at the top and therefore should be applied as much as possible to address analytical efforts towards effective goals. In addition, an increasing number of laboratories worldwide are adopting risk management strategies such as FMEA, FRACAS, LEAN and Six Sigma since these techniques allow the identification of the most critical steps in the total testing process, and to reduce the patient-related risk of error. As a matter of fact, an increasing number of laboratory professionals recognize the importance of understanding and monitoring any step in the total testing process, including the appropriateness of the test request as well as the appropriate interpretation and utilization of test results.

Safety Precautions and Operating Procedures in an (A)BSL-4 Laboratory: 2. General Practices.

PubMed

Mazur, Steven; Holbrook, Michael R; Burdette, Tracey; Joselyn, Nicole; Barr, Jason; Pusl, Daniela; Bollinger, Laura; Coe, Linda; Jahrling, Peter B; Lackemeyer, Matthew G; Wada, Jiro; Kuhn, Jens H; Janosko, Krisztina

2016-10-03

Work in a biosafety level 4 (BSL-4) containment laboratory requires time and great attention to detail. The same work that is done in a BSL-2 laboratory with non-high-consequence pathogens will take significantly longer in a BSL-4 setting. This increased time requirement is due to a multitude of factors that are aimed at protecting the researcher from laboratory-acquired infections, the work environment from potential contamination and the local community from possible release of high-consequence pathogens. Inside the laboratory, movement is restricted due to air hoses attached to the mandatory full-body safety suits. In addition, disinfection of every item that is removed from Class II biosafety cabinets (BSCs) is required. Laboratory specialists must be trained in the practices of the BSL-4 laboratory and must show high proficiency in the skills they are performing. The focus of this article is to outline proper procedures and techniques to ensure laboratory biosafety and experimental accuracy using a standard viral plaque assay as an example procedure. In particular, proper techniques to work safely in a BSL-4 environment when performing an experiment will be visually emphasized. These techniques include: setting up a Class II BSC for experiments, proper cleaning of the Class II BSC when finished working, waste management and safe disposal of waste generated inside a BSL-4 laboratory, and the removal of inactivated samples from inside a BSL-4 laboratory to the BSL-2 laboratory.

Safety in the Chemical Laboratory: The Selection of Eyewash Stations for Laboratory Use.

ERIC Educational Resources Information Center

Walters, Douglas B.; And Others

1988-01-01

Evaluates and compares common eyewash stations currently being used in laboratories. Discusses types available, installation, water supply needs, and maintenance. Lists current OSHA eyewash station standards. (ML)

Use of non-standardised micro-destructive techniques in the characterization of traditional construction materials

NASA Astrophysics Data System (ADS)

Ioannou, Ioannis; Theodoridou, Magdalini; Modestou, Sevasti; Fournari, Revecca; Dagrain, Fabrice

2013-04-01

The characterization of material properties and the diagnosis of their state of weathering and conservation are three of the most important steps in the field of cultural heritage preservation. Several standardised experimental methods exist, especially for determining the material properties and their durability. However, they are limited in their application by the required size of test specimens and the controlled laboratory conditions needed to undertake the tests; this is especially true when the materials under study constitute immovable parts of heritage structures. The current use of other advanced methods of analysis, such as imaging techniques, in the aforementioned field of research offers invaluable results. However, these techniques may not always be accessible to the wider research community due to their complex nature and relatively high cost of application. This study presents innovative applications of two recently developed cutting techniques; the portable Drilling Resistance Measuring System (DRMS) and the scratch tool. Both methods are defined as micro-destructive, since they only destroy a very small portion of sample material. The general concept of both methods lies within the forces needed to cut a material by linear (scratch tool) or rotational (DRMS) cutting action; these forces are related to the mechanical properties of the material and the technological parameters applied on the tool. Therefore, for a given testing configuration, the only parameter influencing the forces applied is the strength of the material. These two techniques have been used alongside a series of standardised laboratory tests aiming at the correlation of various stone properties (density, porosity, dynamic elastic modulus and uniaxial compressive strength). The results prove the potential of both techniques in assessing the uniaxial compressive strength of stones. The scratch tool has also been used effectively to estimate the compressive strength of mud bricks. It therefore follows that both micro-destructive techniques may prove useful in the physico-mechanical characterization of materials which demand in-situ measurements or allow very limited sampling. Moreover, both techniques have been used, for the first time, to map the distribution of salts in building stone in the laboratory; micro-drilling was also applied in the same context in-situ. The results of the laboratory tests performed on limestone impregnated with sodium and magnesium sulfate confirm that both the scratch tool and the DRMS may successfully detect the location of the salt front, as they respond to pore clogging by salt crystals by providing increased scratching/drilling resistance values. Drilling and scratching of duplicate samples treated with a hydrophobic product show the sensitivity of both techniques as they clearly detect changes to the salt front location (i.e. cryptoflorescence) caused by surface treatments. Both techniques were also successful in highlighting the difference in the crystallisation location and pattern of magnesium sulphate and sodium chloride. In-situ application of the micro-drilling test demonstrated its potential for use in the assessment of masonry salt weathering; the results suggest that this technique may, in fact, be useful as a preventive measure against salt damage. Last but not least, both aforementioned novel micro-destructive techniques have been used to assess the effectiveness of commercially available consolidants. The results of the scratch tool have also been utilised to develop a tomography image of the samples under test. Scratching tomography may potentially be combined with in-situ micro-drilling tests to evaluate the effectiveness of consolidation treatments applied on monuments and historic buildings.

The determination of carbon dioxide concentration using atmospheric pressure ionization mass spectrometry/isotopic dilution and errors in concentration measurements caused by dryers.

PubMed

DeLacy, Brendan G; Bandy, Alan R

2008-01-01

An atmospheric pressure ionization mass spectrometry/isotopically labeled standard (APIMS/ILS) method has been developed for the determination of carbon dioxide (CO(2)) concentration. Descriptions of the instrumental components, the ionization chemistry, and the statistics associated with the analytical method are provided. This method represents an alternative to the nondispersive infrared (NDIR) technique, which is currently used in the atmospheric community to determine atmospheric CO(2) concentrations. The APIMS/ILS and NDIR methods exhibit a decreased sensitivity for CO(2) in the presence of water vapor. Therefore, dryers such as a nafion dryer are used to remove water before detection. The APIMS/ILS method measures mixing ratios and demonstrates linearity and range in the presence or absence of a dryer. The NDIR technique, on the other hand, measures molar concentrations. The second half of this paper describes errors in molar concentration measurements that are caused by drying. An equation describing the errors was derived from the ideal gas law, the conservation of mass, and Dalton's Law. The purpose of this derivation was to quantify errors in the NDIR technique that are caused by drying. Laboratory experiments were conducted to verify the errors created solely by the dryer in CO(2) concentration measurements post-dryer. The laboratory experiments verified the theoretically predicted errors in the derived equations. There are numerous references in the literature that describe the use of a dryer in conjunction with the NDIR technique. However, these references do not address the errors that are caused by drying.

Integration of Video-Based Demonstrations to Prepare Students for the Organic Chemistry Laboratory

NASA Astrophysics Data System (ADS)

Nadelson, Louis S.; Scaggs, Jonathan; Sheffield, Colin; McDougal, Owen M.

2015-08-01

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 videos in five traditional laboratory experiments by integrating them with the standard pre-laboratory student preparation presentations and instructor demonstrations. We assessed the influence of the videos on student laboratory knowledge and performance, using sections of students who did not view the videos as the control. Our analysis of pre-quizzes revealed the control group had equivalent scores to the treatment group, while the post-quiz results show consistently greater learning gains for the treatment group. Additionally, the students who watched the videos as part of their pre-laboratory instruction completed their experiments in less time.

A blinded international study on the reliability of genetic testing for GGGGCC-repeat expansions in C9orf72 reveals marked differences in results among 14 laboratories

PubMed Central

Akimoto, Chizuru; Volk, Alexander E; van Blitterswijk, Marka; Van den Broeck, Marleen; Leblond, Claire S; Lumbroso, Serge; Camu, William; Neitzel, Birgit; Onodera, Osamu; van Rheenen, Wouter; Pinto, Susana; Weber, Markus; Smith, Bradley; Proven, Melanie; Talbot, Kevin; Keagle, Pamela; Chesi, Alessandra; Ratti, Antonia; van der Zee, Julie; Alstermark, Helena; Birve, Anna; Calini, Daniela; Nordin, Angelica; Tradowsky, Daniela C; Just, Walter; Daoud, Hussein; Angerbauer, Sabrina; DeJesus-Hernandez, Mariely; Konno, Takuya; Lloyd-Jani, Anjali; de Carvalho, Mamede; Mouzat, Kevin; Landers, John E; Veldink, Jan H; Silani, Vincenzo; Gitler, Aaron D; Shaw, Christopher E; Rouleau, Guy A; van den Berg, Leonard H; Van Broeckhoven, Christine; Rademakers, Rosa; Andersen, Peter M; Kubisch, Christian

2014-01-01

Background The GGGGCC-repeat expansion in C9orf72 is the most frequent mutation found in patients with amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). Most of the studies on C9orf72 have relied on repeat-primed PCR (RP-PCR) methods for detection of the expansions. To investigate the inherent limitations of this technique, we compared methods and results of 14 laboratories. Methods The 14 laboratories genotyped DNA from 78 individuals (diagnosed with ALS or FTD) in a blinded fashion. Eleven laboratories used a combination of amplicon-length analysis and RP-PCR, whereas three laboratories used RP-PCR alone; Southern blotting techniques were used as a reference. Results Using PCR-based techniques, 5 of the 14 laboratories got results in full accordance with the Southern blotting results. Only 50 of the 78 DNA samples got the same genotype result in all 14 laboratories. There was a high degree of false positive and false negative results, and at least one sample could not be genotyped at all in 9 of the 14 laboratories. The mean sensitivity of a combination of amplicon-length analysis and RP-PCR was 95.0% (73.9–100%), and the mean specificity was 98.0% (87.5–100%). Overall, a sensitivity and specificity of more than 95% was observed in only seven laboratories. Conclusions Because of the wide range seen in genotyping results, we recommend using a combination of amplicon-length analysis and RP-PCR as a minimum in a research setting. We propose that Southern blotting techniques should be the gold standard, and be made obligatory in a clinical diagnostic setting. PMID:24706941

A Highly Efficient Design Strategy for Regression with Outcome Pooling

PubMed Central

Mitchell, Emily M.; Lyles, Robert H.; Manatunga, Amita K.; Perkins, Neil J.; Schisterman, Enrique F.

2014-01-01

The potential for research involving biospecimens can be hindered by the prohibitive cost of performing laboratory assays on individual samples. To mitigate this cost, strategies such as randomly selecting a portion of specimens for analysis or randomly pooling specimens prior to performing laboratory assays may be employed. These techniques, while effective in reducing cost, are often accompanied by a considerable loss of statistical efficiency. We propose a novel pooling strategy based on the k-means clustering algorithm to reduce laboratory costs while maintaining a high level of statistical efficiency when predictor variables are measured on all subjects, but the outcome of interest is assessed in pools. We perform simulations motivated by the BioCycle study to compare this k-means pooling strategy with current pooling and selection techniques under simple and multiple linear regression models. While all of the methods considered produce unbiased estimates and confidence intervals with appropriate coverage, pooling under k-means clustering provides the most precise estimates, closely approximating results from the full data and losing minimal precision as the total number of pools decreases. The benefits of k-means clustering evident in the simulation study are then applied to an analysis of the BioCycle dataset. In conclusion, when the number of lab tests is limited by budget, pooling specimens based on k-means clustering prior to performing lab assays can be an effective way to save money with minimal information loss in a regression setting. PMID:25220822

A highly efficient design strategy for regression with outcome pooling.

PubMed

Mitchell, Emily M; Lyles, Robert H; Manatunga, Amita K; Perkins, Neil J; Schisterman, Enrique F

2014-12-10

The potential for research involving biospecimens can be hindered by the prohibitive cost of performing laboratory assays on individual samples. To mitigate this cost, strategies such as randomly selecting a portion of specimens for analysis or randomly pooling specimens prior to performing laboratory assays may be employed. These techniques, while effective in reducing cost, are often accompanied by a considerable loss of statistical efficiency. We propose a novel pooling strategy based on the k-means clustering algorithm to reduce laboratory costs while maintaining a high level of statistical efficiency when predictor variables are measured on all subjects, but the outcome of interest is assessed in pools. We perform simulations motivated by the BioCycle study to compare this k-means pooling strategy with current pooling and selection techniques under simple and multiple linear regression models. While all of the methods considered produce unbiased estimates and confidence intervals with appropriate coverage, pooling under k-means clustering provides the most precise estimates, closely approximating results from the full data and losing minimal precision as the total number of pools decreases. The benefits of k-means clustering evident in the simulation study are then applied to an analysis of the BioCycle dataset. In conclusion, when the number of lab tests is limited by budget, pooling specimens based on k-means clustering prior to performing lab assays can be an effective way to save money with minimal information loss in a regression setting. Copyright © 2014 John Wiley & Sons, Ltd.

Communication methods and production techniques in fixed prosthesis fabrication: a UK based survey. Part 2: Production techniques

PubMed Central

Berry, J.; Nesbit, M.; Saberi, S.; Petridis, H.

2014-01-01

Aim The aim of this study was to identify the communication methods and production techniques used by dentists and dental technicians for the fabrication of fixed prostheses within the UK from the dental technicians' perspective. This second paper reports on the production techniques utilised. Materials and methods Seven hundred and eighty-two online questionnaires were distributed to the Dental Laboratories Association membership and included a broad range of topics, such as demographics, impression disinfection and suitability, and various production techniques. Settings were managed in order to ensure anonymity of respondents. Statistical analysis was undertaken to test the influence of various demographic variables such as the source of information, the location, and the size of the dental laboratory. Results The number of completed responses totalled 248 (32% response rate). Ninety percent of the respondents were based in England and the majority of dental laboratories were categorised as small sized (working with up to 25 dentists). Concerns were raised regarding inadequate disinfection protocols between dentists and dental laboratories and the poor quality of master impressions. Full arch plastic trays were the most popular impression tray used by dentists in the fabrication of crowns (61%) and bridgework (68%). The majority (89%) of jaw registration records were considered inaccurate. Forty-four percent of dental laboratories preferred using semi-adjustable articulators. Axial and occlusal under-preparation of abutment teeth was reported as an issue in about 25% of cases. Base metal alloy was the most (52%) commonly used alloy material. Metal-ceramic crowns were the most popular choice for anterior (69%) and posterior (70%) cases. The various factors considered did not have any statistically significant effect on the answers provided. The only notable exception was the fact that more methods of communicating the size and shape of crowns were utilised for large laboratories. Conclusion This study suggests that there are continuing issues in the production techniques utilised between dentists and dental laboratories. PMID:25257017

Aseptic laboratory techniques: plating methods.

PubMed

Sanders, Erin R

2012-05-11

Microorganisms are present on all inanimate surfaces creating ubiquitous sources of possible contamination in the laboratory. Experimental success relies on the ability of a scientist to sterilize work surfaces and equipment as well as prevent contact of sterile instruments and solutions with non-sterile surfaces. Here we present the steps for several plating methods routinely used in the laboratory to isolate, propagate, or enumerate microorganisms such as bacteria and phage. All five methods incorporate aseptic technique, or procedures that maintain the sterility of experimental materials. Procedures described include (1) streak-plating bacterial cultures to isolate single colonies, (2) pour-plating and (3) spread-plating to enumerate viable bacterial colonies, (4) soft agar overlays to isolate phage and enumerate plaques, and (5) replica-plating to transfer cells from one plate to another in an identical spatial pattern. These procedures can be performed at the laboratory bench, provided they involve non-pathogenic strains of microorganisms (Biosafety Level 1, BSL-1). If working with BSL-2 organisms, then these manipulations must take place in a biosafety cabinet. Consult the most current edition of the Biosafety in Microbiological and Biomedical Laboratories (BMBL) as well as Material Safety Data Sheets (MSDS) for Infectious Substances to determine the biohazard classification as well as the safety precautions and containment facilities required for the microorganism in question. Bacterial strains and phage stocks can be obtained from research investigators, companies, and collections maintained by particular organizations such as the American Type Culture Collection (ATCC). It is recommended that non-pathogenic strains be used when learning the various plating methods. By following the procedures described in this protocol, students should be able to: Perform plating procedures without contaminating media. Isolate single bacterial colonies by the streak-plating method. Use pour-plating and spread-plating methods to determine the concentration of bacteria. Perform soft agar overlays when working with phage. Transfer bacterial cells from one plate to another using the replica-plating procedure. Given an experimental task, select the appropriate plating method.

Polymyxins: Antibacterial Activity, Susceptibility Testing, and Resistance Mechanisms Encoded by Plasmids or Chromosomes

PubMed Central

Jayol, Aurélie; Nordmann, Patrice

2017-01-01

SUMMARY Polymyxins are well-established antibiotics that have recently regained significant interest as a consequence of the increasing incidence of infections due to multidrug-resistant Gram-negative bacteria. Colistin and polymyxin B are being seriously reconsidered as last-resort antibiotics in many areas where multidrug resistance is observed in clinical medicine. In parallel, the heavy use of polymyxins in veterinary medicine is currently being reconsidered due to increased reports of polymyxin-resistant bacteria. Susceptibility testing is challenging with polymyxins, and currently available techniques are presented here. Genotypic and phenotypic methods that provide relevant information for diagnostic laboratories are presented. This review also presents recent works in relation to recently identified mechanisms of polymyxin resistance, including chromosomally encoded resistance traits as well as the recently identified plasmid-encoded polymyxin resistance determinant MCR-1. Epidemiological features summarizing the current knowledge in that field are presented. PMID:28275006

Precision Mass Property Measurements Using a Five-Wire Torsion Pendulum

NASA Technical Reports Server (NTRS)

Swank, Aaron J.

2012-01-01

A method for measuring the moment of inertia of an object using a five-wire torsion pendulum design is described here. Typical moment of inertia measurement devices are capable of 1 part in 10(exp 3) accuracy and current state of the art techniques have capabilities of about one part in 10(exp 4). The five-wire apparatus design shows the prospect of improving on current state of the art. Current measurements using a laboratory prototype indicate a moment of inertia measurement precision better than a part in 10(exp 4). In addition, the apparatus is shown to be capable of measuring the mass center offset from the geometric center. Typical mass center measurement devices exhibit a measurement precision up to approximately 1 micrometer. Although the five-wire pendulum was not originally designed for mass center measurements, preliminary results indicate an apparatus with a similar design may have the potential of achieving state of the art precision.

Research trend in thermally stimulated current method for development of materials and devices in Japan

NASA Astrophysics Data System (ADS)

Iwamoto, Mitsumasa; Taguchi, Dai

2018-03-01

Thermally stimulated current (TSC) measurement is widely used in a variety of research fields, i.e., physics, electronics, electrical engineering, chemistry, ceramics, and biology. TSC is short-circuit current that flows owing to the displacement of charges in samples during heating. TSC measurement is very simple, but TSC curves give very important information on charge behaviors. In the 1970s, TSC measurement contributed greatly to the development of electrical insulation engineering, semiconductor device technology, and so forth. Accordingly, the TSC experimental technique and its analytical method advanced. Over the past decades, many new molecules and advanced functional materials have been discovered and developed. Along with this, TSC measurement has attracted much attention in industries and academic laboratories as a way of characterizing newly discovered materials and devices. In this review, we report the latest research trend in the TSC method for the development of materials and devices in Japan.

Teaching laboratory neuroscience at bowdoin: the laboratory instructor perspective.

PubMed

Hauptman, Stephen; Curtis, Nancy

2009-01-01

Bowdoin College is a small liberal arts college that offers a comprehensive Neuroscience major. The laboratory experience is an integral part of the major, and many students progress through three stages. A core course offers a survey of concepts and techniques. Four upper-level courses function to give students more intensive laboratory research experience in neurophysiology, molecular neurobiology, social behavior, and learning and memory. Finally, many majors choose to work in the individual research labs of the Neuroscience faculty. We, as laboratory instructors, are vital to the process, and are actively involved in all aspects of the lab-based courses. We provide student instruction in state of the art techniques in neuroscience research. By sharing laboratory teaching responsibilities with course professors, we help to prepare students for careers in laboratory neuroscience and also support and facilitate faculty research programs.

Explosive Contamination from Substrate Surfaces: Differences and Similarities in Contamination Techniques Using RDX and C-4

NASA Astrophysics Data System (ADS)

Miller, C. J.; Yoder, T. S.

2010-06-01

Explosive trace detection equipment has been deployed to airports for more than a decade. During this time, the need for standardized procedures and calibrated trace amounts for ensuring that the systems are operating properly and detecting the correct explosive has been apparent but a standard representative of a fingerprint has been elusive. Standards are also necessary to evaluate instrumentation in the laboratories during development and prior to deployment to determine sample throughput, probability of detection, false positive/negative rates, ease of use by operator, mechanical and/or software problems that may be encountered, and other pertinent parameters that would result in the equipment being unusable during field operations. Since many laboratories do not have access to nor are allowed to handle explosives, the equipment is tested using techniques aimed at simulating the actual explosives fingerprint. This laboratory study focused on examining the similarities and differences in three different surface contamination techniques that are used to performance test explosive trace detection equipment in an attempt to determine how effective the techniques are at replicating actual field samples and to offer scenarios where each contamination technique is applicable. The three techniques used were dry transfer deposition of standard solutions using the Transportation Security Laboratory’s (TSL) patented dry transfer techniques (US patent 6470730), direct deposition of explosive standards onto substrates, and fingerprinting of actual explosives onto substrates. RDX was deposited on the surface of one of five substrates using one of the three different deposition techniques. The process was repeated for each substrate type using each contamination technique. The substrate types used were: 50% cotton/50% polyester as found in T-shirts, 100% cotton with a smooth surface such as that found in a cotton dress shirt, 100% cotton on a rough surface such as that found on canvas or denim, suede leather such as might be found on jackets, purses, or shoes, and painted metal obtained from a car hood at a junk yard. The samples were not pre-cleaned prior to testing and contained sizing agents, and in the case of the metal, oil and dirt. The substrates were photographed using a Zeiss Discover V12 stereoscope with Axiocam ICc1 3 megapixel digital camera to determine the difference in the crystalline structure and surface contamination in an attempt to determine differences and similarities associated with current contamination deposition techniques. Some samples were analyzed using scanning electron microscopy (SEM) and some were extracted and analyzed with high performance liquid chromatography (HPLC) or gas chromatography with an electron capture detector (GC-ECD) to quantify the data.

Is Current CMBR Temperature: The Scale Independent Quantum Gravitational Result of Black Hole Cosmology?

NASA Astrophysics Data System (ADS)

Seshavatharam, U. V. S.; Lakshminarayana, S.

If one is willing to consider the current cosmic microwave back ground temperature as a quantum gravitational effect of the evolving primordial cosmic black hole (universe that constitutes dynamic space-time and exhibits quantum behavior) automatically general theory of relativity and quantum mechanics can be combined into a `scale independent' true unified model of quantum gravity. By considering the `Planck mass' as the initial mass of the baby Hubble volume, past and current physical and thermal parameters of the cosmic black hole can be understood. Current rate of cosmic black hole expansion is being stopped by the microscopic quantum mechanical lengths. In this new direction authors observed 5 important quantum mechanical methods for understanding the current cosmic deceleration. To understand the ground reality of current cosmic rate of expansion, sensitivity and accuracy of current methods of estimating the magnitudes of current CMBR temperature and current Hubble constant must be improved and alternative methods must be developed. If it is true that galaxy constitutes so many stars, each star constitutes so many hydrogen atoms and light is coming from the excited electron of galactic hydrogen atom, then considering redshift as an index of `whole galaxy' receding may not be reasonable. During cosmic evolution, at any time in the past, in hydrogen atom emitted photon energy was always inversely proportional to the CMBR temperature. Thus past light emitted from older galaxy's excited hydrogen atom will show redshift with reference to the current laboratory data. As cosmic time passes, in future, the absolute rate of cosmic expansion can be understood by observing the rate of increase in the magnitude of photon energy emitted from laboratory hydrogen atom. Aged super novae dimming may be due to the effect of high cosmic back ground temperature. Need of new mathematical methods & techniques, computer simulations, advanced engineering skills seem to be essential in this direction.

Technique for the comparison of light spectra from natural and laboratory generated lightning current arcs

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

Mitchard, D., E-mail: mitcharddr@cardiff.ac.uk; Clark, D.; Carr, D.

A technique was developed for the comparison of observed emission spectra from lightning current arcs generated through self-breakdown in air and the use of two types of initiation wire, aluminum bronze and nichrome, against previously published spectra of natural lightning events. A spectrograph system was used in which the wavelength of light emitted by the lightning arc was analyzed to derive elemental interactions. A lightning impulse of up to 100 kA was applied to a two hemispherical tungsten electrode configuration which allowed the effect of the lightning current and lightning arc length to be investigated. A natural lightning reference spectrum wasmore » reconstructed from literature, and generated lightning spectra were obtained from self-breakdown across a 14.0 mm air gap and triggered along initiation wires of length up to 72.4 mm. A comparison of the spectra showed that the generated lightning arc induced via self-breakdown produced a very similar spectrum to that of natural lightning, with the addition of only a few lines from the tungsten electrodes. A comparison of the results from the aluminum bronze initiation wire showed several more lines, whereas results from the nichrome initiation wire differed greatly across large parts of the spectrum. This work highlights the potential use for spectrographic techniques in the study of lightning interactions with surrounding media and materials, and in natural phenomena such as recently observed ball lightning.« less

Using Technology to Enhance the Effectiveness of General Chemistry Laboratory Courses

ERIC Educational Resources Information Center

Carvalho-Knighton, Kathleen M.; Keen-Rocha, Linda

2007-01-01

The effectiveness of two different laboratory techniques is compared to teach students majoring in science in a general chemistry laboratory. The results demonstrated that student laboratory activities with computer-interface systems could improve student understanding.

Modification of heterogeneous chemistry by complex substrate morphology

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

Henson, B.F.; Buelow, S.J.; Robinson, J.M.

1998-12-31

This is the final report of a one-year, Laboratory Directed Research and Development (LDRD) project at Los Alamos National Laboratory (LANL). Chemistry in many environmental systems is determined at some stage by heterogeneous reaction with a surface. Typically the surface exists as a dispersion or matrix of particulate matter or pores, and a determination of the heterogeneous chemistry of the system must address the extent to which the complexity of the environmental surface affects the reaction rates. Reactions that are of current interest are the series of chlorine nitrate reactions important in polar ozone depletion. The authors have applied surfacemore » spectroscopic techniques developed at LANL to address the chemistry of chlorine nitrate reactions on porous nitric and sulfuric acid ice surfaces as a model study of the measurement of complex, heterogeneous reaction rates. The result of the study is an experimental determination of the surface coverage of one adsorbed reagent and a mechanism of reactivity based on the dependence of this coverage on temperature and vapor pressure. The resulting mechanism allows the first comprehensive modeling of chlorine nitrate reaction probability data from several laboratories.« less

Contributive research in compound semiconductor material and related devices

NASA Astrophysics Data System (ADS)

Twist, James R.

1988-05-01

The objective of this program was to provide the Electronic Device Branch (AFWAL/AADR) with the support needed to perform state of the art electronic device research. In the process of managing and performing on the project, UES has provided a wide variety of scientific and engineering talent who worked in-house for the Avionics Laboratory. These personnel worked on many different types of research programs from gas phase microwave driven lasers, CVD and MOCVD of electronic materials to Electronic Device Technology for new devices. The fields of research included MBE and theoretical research in this novel growth technique. Much of the work was slanted towards the rapidly developing technology of GaAs and the general thrust of the research that these tasks started has remained constant. This work was started because the Avionics Laboratory saw a chance to advance the knowledge and level of the current device technology by working in the compounds semiconductor field. UES is pleased to have had the opportunity to perform on this program and is looking forward to future efforts with the Avionics Laboratory.

Application of Emulsified Zero-Valent Iron to Marine Environments

NASA Technical Reports Server (NTRS)

Quinn, Jacqueline W.; Brooks, Kathleen B.; Geiger, Cherie L.; Clausen, Christian A.; Milum, Kristen M.

2006-01-01

Contamination of marine waters and sediments with heavy metals and dense non-aqueous phase liquids (DNAPLs) including chlorinated solvents, pesticides and PCBs pose ecological and human health risks through the potential of the contaminant to bioaccumulate in fish, shellfish and avian populations. The contaminants enter marine environments through improper disposal techniques and storm water runoff. Current remediation technologies for application to marine environments include costly dredging and off-site treatment of the contaminated media. Emulsified zero-valent iron (EZVI) has been proven to effectively degrade dissolved-phase and DNAPL-phase contaminants in freshwater environments on both the laboratory and field-scale level. Emulsified Zero-Valent Metal (EZVM) using metals such as iron and/or magnesium have been shown in the laboratory and on the bench scale to be effective at removing metals contamination in freshwater environments. The application to marine environments, however, is only just being explored. This paper discusses. the potential use of EZVI or EZVM in brackish and saltwater environments, with supporting laboratory data detailing its effectiveness on trichloroethylene, lead, copper, nickel and cadmium.

Geometric factor and influence of sensors in the establishment of a resistivity-moisture relation in soil samples

NASA Astrophysics Data System (ADS)

López-Sánchez, M.; Mansilla-Plaza, L.; Sánchez-de-laOrden, M.

2017-10-01

Prior to field scale research, soil samples are analysed on a laboratory scale for electrical resistivity calibrations. Currently, there are a variety of field instruments to estimate the water content in soils using different physical phenomena. These instruments can be used to develop moisture-resistivity relationships on the same soil samples. This assures that measurements are performed on the same material and under the same conditions (e.g., humidity and temperature). A geometric factor is applied to the location of electrodes, in order to calculate the apparent electrical resistivity of the laboratory test cells. This geometric factor can be determined in three different ways: by means of the use of an analytical approximation, laboratory trials (experimental approximation), or by the analysis of a numerical model. The first case, the analytical approximation, is not appropriate for complex cells or arrays. And both, the experimental and numerical approximation can lead to inaccurate results. Therefore, we propose a novel approach to obtain a compromise solution between both techniques, providing a more precise determination of the geometrical factor.

A Laboratory Study of the Charging/Discharging Mechanisms of a Dust Particle Exposed to an Electron Beam

NASA Technical Reports Server (NTRS)

Venturini, C. C.; Spann, J. F.; Comfort, R. H.

1999-01-01

The interaction of micron sized particles or "dust particles" with different space and planetary environments has become an important area of research. One particular area of interest is how dust particles interact with plasmas. Studies have shown that charged dust particles immersed in plasmas can alter plasma characteristics, while ions and electrons in plasmas can affect a particle's potential and thereby, its interaction with other particles. The basis for understanding these phenomena is the charging mechanisms of the dust particle, specifically, how the particle's charge and characteristics are affected when exposed to ions and electrons. At NASA Marshall Space Flight Center, a laboratory experiment has been developed to study the interaction of dust particles with electrons. Using a unique laboratory technique known as electrodynamic suspension, a single charged particle is suspended in a modified quadrupole trap. Once suspended, the particle is then exposed to an electron beam to study the charging/discharging mechanisms due to collisions of energetic electrons. The change in the particle's charge, approximations of the charging/discharging currents, and the charging/discharging yield are calculated.

Contributions of CCLM to advances in quality control.

PubMed

Kazmierczak, Steven C

2013-01-01

Abstract The discipline of laboratory medicine is relatively young when considered in the context of the history of medicine itself. The history of quality control, within the context of laboratory medicine, also enjoys a relatively brief, but rich history. Laboratory quality control continues to evolve along with advances in automation, measurement techniques and information technology. Clinical Chemistry and Laboratory Medicine (CCLM) has played a key role in helping disseminate information about the proper use and utility of quality control. Publication of important advances in quality control techniques and dissemination of guidelines concerned with laboratory quality control has undoubtedly helped readers of this journal keep up to date on the most recent developments in this field.

Blood doping by cobalt. Should we measure cobalt in athletes?

PubMed Central

Lippi, Giuseppe; Franchini, Massimo; Guidi, Gian Cesare

2006-01-01

Background Blood doping is commonplace in competitive athletes who seek to enhance their aerobic performances through illicit techniques. Presentation of the hypothesis Cobalt, a naturally-occurring element with properties similar to those of iron and nickel, induces a marked and stable polycythemic response through a more efficient transcription of the erythropoietin gene. Testing the hypothesis Although little information is available so far on cobalt metabolism, reference value ranges or supplementation in athletes, there is emerging evidence that cobalt is used as a supplement and increased serum concentrations are occasionally observed in athletes. Therefore, given the athlete's connatural inclination to experiment with innovative, unfair and potentially unhealthy doping techniques, cobalt administration might soon become the most suited complement or surrogate for erythropoiesis-stimulating substances. Nevertheless, cobalt administration is not free from unsafe consequences, which involve toxic effects on heart, liver, kidney, thyroid and cancer promotion. Implications of the hypothesis Cobalt is easily purchasable, inexpensive and not currently comprehended within the World Anti-Doping Agency prohibited list. Moreover, available techniques for measuring whole blood, serum, plasma or urinary cobalt involve analytic approaches which are currently not practical for antidoping laboratories. Thus more research on cobalt metabolism in athletes is compelling, along with implementation of effective strategies to unmask this potentially deleterious doping practice PMID:16863591

40 CFR 141.705 - Approved laboratories.

Code of Federal Regulations, 2014 CFR

2014-07-01

... Cryptosporidium analysis by an equivalent State laboratory certification program. (b) E. coli. Any laboratory... coliform or fecal coliform analysis under § 141.74 is approved for E. coli analysis under this subpart when the laboratory uses the same technique for E. coli that the laboratory uses for § 141.74. (c...

40 CFR 141.705 - Approved laboratories.

Code of Federal Regulations, 2013 CFR

2013-07-01

... Cryptosporidium analysis by an equivalent State laboratory certification program. (b) E. coli. Any laboratory... coliform or fecal coliform analysis under § 141.74 is approved for E. coli analysis under this subpart when the laboratory uses the same technique for E. coli that the laboratory uses for § 141.74. (c...

40 CFR 141.705 - Approved laboratories.

Code of Federal Regulations, 2012 CFR

2012-07-01

... Cryptosporidium analysis by an equivalent State laboratory certification program. (b) E. coli. Any laboratory... coliform or fecal coliform analysis under § 141.74 is approved for E. coli analysis under this subpart when the laboratory uses the same technique for E. coli that the laboratory uses for § 141.74. (c...

40 CFR 141.705 - Approved laboratories.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Cryptosporidium analysis by an equivalent State laboratory certification program. (b) E. coli. Any laboratory... coliform or fecal coliform analysis under § 141.74 is approved for E. coli analysis under this subpart when the laboratory uses the same technique for E. coli that the laboratory uses for § 141.74. (c...

40 CFR 141.705 - Approved laboratories.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Cryptosporidium analysis by an equivalent State laboratory certification program. (b) E. coli. Any laboratory... coliform or fecal coliform analysis under § 141.74 is approved for E. coli analysis under this subpart when the laboratory uses the same technique for E. coli that the laboratory uses for § 141.74. (c...

Virtual lab demonstrations improve students' mastery of basic biology laboratory techniques.

PubMed

Maldarelli, Grace A; Hartmann, Erica M; Cummings, Patrick J; Horner, Robert D; Obom, Kristina M; Shingles, Richard; Pearlman, Rebecca S

2009-01-01

Biology laboratory classes are designed to teach concepts and techniques through experiential learning. Students who have never performed a technique must be guided through the process, which is often difficult to standardize across multiple lab sections. Visual demonstration of laboratory procedures is a key element in teaching pedagogy. The main goals of the study were to create videos explaining and demonstrating a variety of lab techniques that would serve as teaching tools for undergraduate and graduate lab courses and to assess the impact of these videos on student learning. Demonstrations of individual laboratory procedures were videotaped and then edited with iMovie. Narration for the videos was edited with Audacity. Undergraduate students were surveyed anonymously prior to and following screening to assess the impact of the videos on student lab performance by completion of two Participant Perception Indicator surveys. A total of 203 and 171 students completed the pre- and posttesting surveys, respectively. Statistical analyses were performed to compare student perceptions of knowledge of, confidence in, and experience with the lab techniques before and after viewing the videos. Eleven demonstrations were recorded. Chi-square analysis revealed a significant increase in the number of students reporting increased knowledge of, confidence in, and experience with the lab techniques after viewing the videos. Incorporation of instructional videos as prelaboratory exercises has the potential to standardize techniques and to promote successful experimental outcomes.

Survey of Biochemical Separation Techniques

ERIC Educational Resources Information Center

Nilsson, Melanie R.

2007-01-01

A simple laboratory exercise is illustrated that exposes students to wide range of separation techniques in one laboratory program and provides a nice complement to a project-oriented program. Students have learned the basic principles of syringe filtration, centricon, dialysis, gel filtration and solid-phase extraction methodologies and have got…

Development of an optical microscopy system for automated bubble cloud analysis.

PubMed

Wesley, Daniel J; Brittle, Stuart A; Toolan, Daniel T W

2016-08-01

Recently, the number of uses of bubbles has begun to increase dramatically, with medicine, biofuel production, and wastewater treatment just some of the industries taking advantage of bubble properties, such as high mass transfer. As a result, more and more focus is being placed on the understanding and control of bubble formation processes and there are currently numerous techniques utilized to facilitate this understanding. Acoustic bubble sizing (ABS) and laser scattering techniques are able to provide information regarding bubble size and size distribution with minimal data processing, a major advantage over current optical-based direct imaging approaches. This paper demonstrates how direct bubble-imaging methods can be improved upon to yield high levels of automation and thus data comparable to ABS and laser scattering. We also discuss the added benefits of the direct imaging approaches and how it is possible to obtain considerable additional information above and beyond that which ABS and laser scattering can supply. This work could easily be exploited by both industrial-scale operations and small-scale laboratory studies, as this straightforward and cost-effective approach is highly transferrable and intuitive to use.

Technological Microbiology: Development and Applications

PubMed Central

Vitorino, Luciana C.; Bessa, Layara A.

2017-01-01

Over thousands of years, modernization could be predicted for the use of microorganisms in the production of foods and beverages. However, the current accelerated pace of new food production is due to the rapid incorporation of biotechnological techniques that allow the rapid identification of new molecules and microorganisms or even the genetic improvement of known species. At no other time in history have microorganisms been so present in areas such as agriculture and medicine, except as recognized villains. Currently, however, beneficial microorganisms such as plant growth promoters and phytopathogen controllers are required by various agricultural crops, and many species are being used as biofactories of important pharmacological molecules. The use of biofactories does not end there: microorganisms have been explored for the synthesis of diverse chemicals, fuel molecules, and industrial polymers, and strains environmentally important due to their biodecomposing or biosorption capacity have gained interest in research laboratories and in industrial activities. We call this new microbiology Technological Microbiology, and we believe that complex techniques, such as heterologous expression and metabolic engineering, can be increasingly incorporated into this applied science, allowing the generation of new and improved products and services. PMID:28539920

Methodology for Designing and Developing a New Ultra-Wideband Antenna Based on Bio-Inspired Optimization Techniques

DTIC Science & Technology

2017-11-01

ARL-TR-8225 ● NOV 2017 US Army Research Laboratory Methodology for Designing and Developing a New Ultra-Wideband Antenna Based...Research Laboratory Methodology for Designing and Developing a New Ultra-Wideband Antenna Based on Bio-Inspired Optimization Techniques by...SUBTITLE Methodology for Designing and Developing a New Ultra-Wideband Antenna Based on Bio-Inspired Optimization Techniques 5a. CONTRACT NUMBER

A Discrete Scatterer Technique for Evaluating Electromagnetic Scattering from Trees

DTIC Science & Technology

2016-09-01

ARL-TR-7799 ● SEP 2016 US Army Research Laboratory A Discrete Scatterer Technique for Evaluating Electromagnetic Scattering from...longer needed. Do not return it to the originator. ARL-TR-7799 ● SEP 2016 US Army Research Laboratory A Discrete Scatterer Technique...DD-MM-YYYY) September 2016 2. REPORT TYPE Technical Report 3. DATES COVERED (From - To) 2015–2016 4. TITLE AND SUBTITLE A Discrete Scatterer

Microwave remote sensing laboratory design

NASA Technical Reports Server (NTRS)

Friedman, E.

1979-01-01

Application of active and passive microwave remote sensing to the study of ocean pollution is discussed. Previous research efforts, both in the field and in the laboratory were surveyed to derive guidance for the design of a laboratory program of research. The essential issues include: choice of radar or radiometry as the observational technique; choice of laboratory or field as the research site; choice of operating frequency; tank sizes and material; techniques for wave generation and appropriate wavelength spectrum; methods for controlling and disposing of pollutants used in the research; and pollutants other than oil which could or should be studied.

Venus surface peeking through the atmosphere - gaining a global perspective on the surface composition through near infrared observations

NASA Astrophysics Data System (ADS)

Helbert, J.; Dyar, M. D.; Maturilli, A.; D'Amore, M.; Ferrari, S.; Mueller, N. T.; Smrekar, S. E.

2017-12-01

Venus is the most Earth-like of the terrestrial planets, though very little is known about its surface composition. Thanks to recent advances in laboratory spectroscopy and spectral analysis techniques, this is about to change. Although the atmosphere prohibits observations of the surface with traditional imaging techniques over much of the EM spectral range, five transparent windows between 0.86 µm and 1.18 µm occur in the atmosphere's CO2 spectrum. New high temperature laboratory spectra from the Planetary Spectroscopy Laboratory at DLR show that spectra in these windows are highly diagnostic for surface mineralogy [1]. The Venus Emissivity Mapper (VEM) [2] builds on these recent advances. It is proposed for NASA's Venus Origins Explorer where a radar will provided the needed high-resolution altimetry and ESA's EnVision would provide stereo topography instead. VEM is the first flight instrument specially designed to focus solely on mapping Venus' surface using the windows around 1 µm. Operating in situ from Venus orbit, VEM will provide a global map of composition as well as redox state of the surface, enabling a comprehensive picture of surface-atmosphere interaction on Venus. VEM will return a complex data set containing surface, atmospheric, cloud, and scattering information. Total planned data volume for a typical mission scenario exceeds 1TB. Classical analysis techniques have been successfully used for VIRTIS on Venus Express [3-5] and could be employed with the VEM data. However, application of machine learning approaches to this rich dataset is vastly more efficient, as has already been confirmed with laboratory data. Binary classifiers [6] demonstrate that at current best estimate errors, basalt spectra are confidently discriminated from basaltic andesites, andesites, and rhyolite/granite. Applying the approach of self-organizing maps to the increasingly large set of laboratory measurements allows searching for additional mineralogical indicators, especially including their temperature dependence. [1] Dyar M. D. et al. 2017 LPS XLVIII, #1512. [2] Helbert, J. et al. 2016. San Diego, CA: SPIE. [3] Smrekar, S.E., et al. Science, 2010 328(5978), 605-8. [4] Helbert, J., et al., GRL, 2008 35(11). [5] Mueller, N., et al., JGR, 2008 113[6] Dyar M. D. et al. 2017 LPS XLVIII, #3014.

A MASSive Laboratory Tour. An Interactive Mass Spectrometry Outreach Activity for Children

NASA Astrophysics Data System (ADS)

Jungmann, Julia H.; Mascini, Nadine E.; Kiss, Andras; Smith, Donald F.; Klinkert, Ivo; Eijkel, Gert B.; Duursma, Marc C.; Cillero Pastor, Berta; Chughtai, Kamila; Chughtai, Sanaullah; Heeren, Ron M. A.

2013-07-01

It is imperative to fascinate young children at an early stage in their education for the analytical sciences. The exposure of the public to mass spectrometry presently increases rapidly through the common media. Outreach activities can take advantage of this exposure and employ mass spectrometry as an exquisite example of an analytical science in which children can be fascinated. The presented teaching modules introduce children to mass spectrometry and give them the opportunity to experience a modern research laboratory. The modules are highly adaptable and can be applied to young children from the age of 6 to 14 y. In an interactive tour, the students explore three major scientific concepts related to mass spectrometry; the building blocks of matter, charged particle manipulation by electrostatic fields, and analyte identification by mass analysis. Also, the students carry out a mass spectrometry experiment and learn to interpret the resulting mass spectra. The multistage, inquiry-based tour contains flexible methods, which teach the students current-day research techniques and possible applications to real research topics. Besides the scientific concepts, laboratory safety and hygiene are stressed and the students are enthused for the analytical sciences by participating in "hands-on" work. The presented modules have repeatedly been successfully employed during laboratory open days. They are also found to be extremely suitable for (early) high school science classes during laboratory visit-focused field trips.

Electromagnetic pulse-induced current measurement device

NASA Astrophysics Data System (ADS)

Gandhi, Om P.; Chen, Jin Y.

1991-08-01

To develop safety guidelines for exposure to high fields associated with an electromagnetic pulse (EMP), it is necessary to devise techniques that would measure the peak current induced in the human body. The main focus of this project was to design, fabricate, and test a portable, self-contained stand-on device that would measure and hold the peak current and the integrated change Q. The design specifications of the EMP-Induced Current Measurement Device are as follows: rise time of the current pulse, 5 ns; peak current, 20-600 A; charge Q, 0-20 microcoulombs. The device uses a stand-on parallel-plate bilayer sensor and fast high-frequency circuit that are well-shielded against spurious responses to high incident fields. Since the polarity of the incident peak electric field of the EMP may be either positive or negative, the induced peak current can also be positive or negative. Therefore, the device is designed to respond to either of these polarities and measure and hold both the peak current and the integrated charge which are simultaneously displayed on two separate 3-1/2 digit displays. The prototype device has been preliminarily tested with the EMP's generated at the Air Force Weapons Laboratory (ALECS facility) at Kirtland AFB, New Mexico.

Metabolomics for laboratory diagnostics.

PubMed

Bujak, Renata; Struck-Lewicka, Wiktoria; Markuszewski, Michał J; Kaliszan, Roman

2015-09-10

Metabolomics is an emerging approach in a systems biology field. Due to continuous development in advanced analytical techniques and in bioinformatics, metabolomics has been extensively applied as a novel, holistic diagnostic tool in clinical and biomedical studies. Metabolome's measurement, as a chemical reflection of a current phenotype of a particular biological system, is nowadays frequently implemented to understand pathophysiological processes involved in disease progression as well as to search for new diagnostic or prognostic biomarkers of various organism's disorders. In this review, we discussed the research strategies and analytical platforms commonly applied in the metabolomics studies. The applications of the metabolomics in laboratory diagnostics in the last 5 years were also reviewed according to the type of biological sample used in the metabolome's analysis. We also discussed some limitations and further improvements which should be considered taking in mind potential applications of metabolomic research and practice. Copyright © 2014 Elsevier B.V. All rights reserved.

Understanding Turbulence using Active and Passive Multipoint Measurements in Laboratory Magnetospheres

NASA Astrophysics Data System (ADS)

Mauel, M. E.; Abler, M. C.; Qian, T. M.; Saperstein, A.; Yan, J. R.

2017-10-01

In a laboratory magnetosphere, plasma is confined by a strong dipole magnet, and interchange and entropy mode turbulence can be studied and controlled in near steady-state conditions. Turbulence is dominated by long wavelength modes exhibiting chaotic dynamics, intermitency, and an inverse spectral cascade. Here, we summarize recent results: (i) high-resolution measurement of the frequency-wavenumber power spectrum using Capon's ``maximum likelihood method'', and (ii) direct measurement of the nonlinear coupling of interchange/entropy modes in a turbulent plasma through driven current injection at multiple locations and frequencies. These observations well-characterize plasma turbulence over a broad band of wavelengths and frequencies. Finally, we also discuss the application of these techniques to space-based experiments and observations aimed to reveal the nature of heliospheric and magnetospheric plasma turbulence. Supported by NSF-DOE Partnership in Plasma Science Grant DE-FG02-00ER54585.

Ocean Virtual Laboratory: A New Way to Explore Multi-Sensor Synergy Demonstrated over the Agulhas Region

NASA Astrophysics Data System (ADS)

Collard, F.; Quartly, G. D.; Konik, M.; Johannessen, J. A.; Korosov, A.; Chapron, B.; Piolle, J.-F.; Herledan, S.; Darecki, M.; Isar, A.; Nafornita, C.

2015-12-01

Ocean Virtual Laboratory is an ESA-funded project to prototype the concept of a single point of access for all satellite remote-sensing data with ancillary model output and in situ measurements for a given region. The idea is to provide easy access for the non-specialist to both data and state-of-the-art processing techniques and enable their easy analysis and display. The project, led by OceanDataLab, is being trialled in the region of the Agulhas Current, as it contains signals of strong contrast (due to very energetic upper ocean dynamics) and special SAR data acquisitions have been recorded there. The project also encourages the take up of Earth Observation data by developing training material to help those not in large scientific or governmental organizations make the best use of what data are available. The website for access is: http://ovlproject.oceandatalab.com/

Enhanced Training for Cyber Situational Awareness in Red versus Blue Team Exercises

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

Carbajal, Armida J.; Stevens-Adams, Susan Marie; Silva, Austin Ray

This report summarizes research conducted through the Sandia National Laboratories Enhanced Training for Cyber Situational Awareness in Red Versus Blue Team Exercises Laboratory Directed Research and Development project. The objective of this project was to advance scientific understanding concerning how to best structure training for cyber defenders. Two modes of training were considered. The baseline training condition (Tool-Based training) was based on current practices where classroom instruction focuses on the functions of a software tool with various exercises in which students apply those functions. In the second training condition (Narrative-Based training), classroom instruction addressed software functions, but in the contextmore » of adversary tactics and techniques. It was hypothesized that students receiving narrative-based training would gain a deeper conceptual understanding of the software tools and this would be reflected in better performance within a red versus blue team exercise.« less

Inertial Confinement Fusion Quarterly Report: April--June 1993. Volume 3, Number 3

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

MacGowan, B.J.; Kotowski, M.; Schleich, D.

1993-11-01

This issue of the ICF Quarterly contains six articles describing recent advances in Lawrence Livermore National Laboratory`s inertial confinement fusion (ICF) program. The current emphasis of the ICF program is in support of DOE`s National Ignition Facility (NIF) initiative for demonstrating ignition and gain with a 1-2 MJ glass laser. The articles describe recent Nova experiments and investigations tailored towards enhancing understanding of the key physics and technological issues for the NIF. Titles of the articles are: development of large-aperture KDP crystals; inner-shell photo-ionized X-ray lasers; X-ray radiographic measurements of radiation-driven shock and interface motion in solid density materials; themore » role of nodule defects in laser-induced damage of multilayer optical coatings; techniques for Mbar to near-Gbar equation-of-state measurements with the Nova laser; parametric instabilities and laser-beam smoothing.« less

Mars Science Laboratory Launch-Arrival Space Study: A Pork Chop Plot Analysis

NASA Technical Reports Server (NTRS)

Cianciolo, Alicia Dwyer; Powell, Richard; Lockwood, Mary Kae

2006-01-01

Launch-Arrival, or "pork chop", plot analysis can provide mission designers with valuable information and insight into a specific launch and arrival space selected for a mission. The study begins with the array of entry states for each pair of selected Earth launch and Mars arrival dates, and nominal entry, descent and landing trajectories are simulated for each pair. Parameters of interest, such as maximum heat rate, are plotted in launch-arrival space. The plots help to quickly identify launch and arrival regions that are not feasible under current constraints or technology and also provide information as to what technologies may need to be developed to reach a desired region. This paper provides a discussion of the development, application, and results of a pork chop plot analysis to the Mars Science Laboratory mission. This technique is easily applicable to other missions at Mars and other destinations.

High-resolution x-ray tomography using laboratory sources

NASA Astrophysics Data System (ADS)

Tkachuk, Andrei; Feser, Michael; Cui, Hongtao; Duewer, Fred; Chang, Hauyee; Yun, Wenbing

2006-08-01

X-ray computed tomography (XCT) is a powerful nondestructive 3D imaging technique, which enables the visualization of the three dimensional structure of complex, optically opaque samples. High resolution XCT using Fresnel zone plate lenses has been confined in the past to synchrotron radiation centers due to the need for a bright and intense source of x-rays. This confinement severely limits the availability and accessibility of x-ray microscopes and the wide proliferation of this methodology. We are describing a sub-50nm resolution XCT system operating at 8 keV in absorption and Zernike phase contrast mode based on a commercially available laboratory x-ray source. The system utilizes high-efficiency Fresnel zone plates with an outermost zone width of 35 nm and 700 nm structure height resulting in a current spatial resolution better than 50 nm. In addition to the technical description of the system and specifications, we present application examples in the semiconductor field.

The Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry (MALDI-TOF MS) identification versus biochemical tests: a study with enterobacteria from a dairy cattle environment.

PubMed

Rodrigues, Naiara Miranda Bento; Bronzato, Greiciane França; Santiago, Gabrielli Stefaninni; Botelho, Larissa Alvarenga Batista; Moreira, Beatriz Meurer; Coelho, Irene da Silva; Souza, Miliane Moreira Soares de; Coelho, Shana de Mattos de Oliveira

Mastitis adversely affects milk production and in general cows do not regain their full production levels post recovery, leading to considerable economic losses. Moreover the percentage decrease in milk production depends on the specific pathogen that caused the infection and enterobacteria are responsible for this greater reduction. Phenotypic tests are among the currently available methods used worldwide to identify enterobacteria; however they tend to misdiagnose the species despite the multiple tests carried out. On the other hand The Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry (MALDI-TOF MS) technique has been attracting attention for its precise identification of several microorganisms at species level. In the current study, 183 enterobacteria were detected in milk (n=47) and fecal samples (n=94) from cows, and samples from water (n=23) and milk lines (n=19). All these samples were collected from a farm in Rio de Janeiro with the specific purpose of presenting the MALDI-TOF MS technique as an efficient methodology to identify Enterobacteriaceae from bovine environments. The MALDI-TOF MS technique results matched the biochemical test results in 92.9% (170/183) of the enterobacteria species and the gyrB sequencing confirmed 100% of the proteomic technique results. The amino acid decarboxylation test made the most misidentifications and Enterobacter spp. was the most misidentified genus (76.9%, 10/13). These results aim to clarify the current biochemical errors in enterobacteria identification, considering isolates from a bovine environment, and show the importance for more careful readings of phenotypic tests which are often used in veterinary microbiology laboratories. Copyright © 2016 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

Rethinking developmental toxicity testing: Evolution or revolution?

PubMed

Scialli, Anthony R; Daston, George; Chen, Connie; Coder, Prägati S; Euling, Susan Y; Foreman, Jennifer; Hoberman, Alan M; Hui, Julia; Knudsen, Thomas; Makris, Susan L; Morford, LaRonda; Piersma, Aldert H; Stanislaus, Dinesh; Thompson, Kary E

2018-06-01

Current developmental toxicity testing adheres largely to protocols suggested in 1966 involving the administration of test compound to pregnant laboratory animals. After more than 50 years of embryo-fetal development testing, are we ready to consider a different approach to human developmental toxicity testing? A workshop was held under the auspices of the Developmental and Reproductive Toxicology Technical Committee of the ILSI Health and Environmental Sciences Institute to consider how we might design developmental toxicity testing if we started over with 21st century knowledge and techniques (revolution). We first consider what changes to the current protocols might be recommended to make them more predictive for human risk (evolution). The evolutionary approach includes modifications of existing protocols and can include humanized models, disease models, more accurate assessment and testing of metabolites, and informed approaches to dose selection. The revolution could start with hypothesis-driven testing where we take what we know about a compound or close analog and answer specific questions using targeted experimental techniques rather than a one-protocol-fits-all approach. Central to the idea of hypothesis-driven testing is the concept that testing can be done at the level of mode of action. It might be feasible to identify a small number of key events at a molecular or cellular level that predict an adverse outcome and for which testing could be performed in vitro or in silico or, rarely, using limited in vivo models. Techniques for evaluating these key events exist today or are in development. Opportunities exist for refining and then replacing current developmental toxicity testing protocols using techniques that have already been developed or are within reach. © 2018 The Authors. Birth Defects Research Published by Wiley Periodicals, Inc.

Statistical inference for the within-device precision of quantitative measurements in assay validation.

PubMed

Liu, Jen-Pei; Lu, Li-Tien; Liao, C T

2009-09-01

Intermediate precision is one of the most important characteristics for evaluation of precision in assay validation. The current methods for evaluation of within-device precision recommended by the Clinical Laboratory Standard Institute (CLSI) guideline EP5-A2 are based on the point estimator. On the other hand, in addition to point estimators, confidence intervals can provide a range for the within-device precision with a probability statement. Therefore, we suggest a confidence interval approach for assessment of the within-device precision. Furthermore, under the two-stage nested random-effects model recommended by the approved CLSI guideline EP5-A2, in addition to the current Satterthwaite's approximation and the modified large sample (MLS) methods, we apply the technique of generalized pivotal quantities (GPQ) to derive the confidence interval for the within-device precision. The data from the approved CLSI guideline EP5-A2 illustrate the applications of the confidence interval approach and comparison of results between the three methods. Results of a simulation study on the coverage probability and expected length of the three methods are reported. The proposed method of the GPQ-based confidence intervals is also extended to consider the between-laboratories variation for precision assessment.

Measurement of discharge using tracers

USGS Publications Warehouse

Kilpatrick, Frederick A.; Cobb, Ernest D.

1984-01-01

The development of fluorescent dyes and fluorometers that can measure these dyes at very low concentrations has made dye-dilution methods practical for measuring discharge. These methods are particularly useful for determining discharge under certain flow conditions that are unfavorable for current meter measurements. These include small streams, canals, and pipes where:Turbulence is excessive for current meter measurement but conducive to good mixing.Moving rocks and debris are damaging to any instruments placed in the flow.Cross-sectional areas or velocities are indeterminant or changing.There are some unsteady flows such as exist with storm-runoff events on small streams.The flow is physically inaccessible or unsafe.From a practical standpoint, such measurements are limited primarily to small streams due to excessively long channel mixing lengths required of larger streams. Very good accuracy can be obtained provided:Adequate mixing length and time are allowed.Careful field and laboratory techniques are employed.Dye losses are not significant.This manual describes the slug-injection and constant-rate injection methods of performing tracer-dilution measurements. Emphasis is on the use of fluorescent dyes as tracers and the equipment, field methods, and Laboratory procedures for performing such measurements. The tracer-velocity method is also briefly discussed.

Fundamentals of functional imaging II: emerging MR techniques and new methods of analysis.

PubMed

Luna, A; Martín Noguerol, T; Mata, L Alcalá

2018-05-01

Current multiparameter MRI protocols integrate structural, physiological, and metabolic information about cancer. Emerging techniques such as arterial spin-labeling (ASL), blood oxygen level dependent (BOLD), MR elastography, chemical exchange saturation transfer (CEST), and hyperpolarization provide new information and will likely be integrated into daily clinical practice in the near future. Furthermore, there is great interest in the study of tumor heterogeneity as a prognostic factor and in relation to resistance to treatment, and this interest is leading to the application of new methods of analysis of multiparametric protocols. In parallel, new oncologic biomarkers that integrate the information from MR with clinical, laboratory, genetic, and histologic findings are being developed, thanks to the application of big data and artificial intelligence. This review analyzes different emerging MR techniques that are able to evaluate the physiological, metabolic, and mechanical characteristics of cancer, as well as the main clinical applications of these techniques. In addition, it summarizes the most novel methods of analysis of functional radiologic information in oncology. Copyright © 2018 SERAM. Publicado por Elsevier España, S.L.U. All rights reserved.

APTI Course 450, Source Sampling for Particulate Pollutants. Instructor's Guide.

ERIC Educational Resources Information Center

Aldina, G. J.; And Others

This manual covers a four and one half day laboratory course in source sampling for particulates. The course presents principles and techniques necessary for performing isokinetic source sampling procedures. Lectures cover formulas dealing with basic fluid mechanics appropriate to the techniques employed. Laboratory exercises are intended to…

Simple & Rapid Generation of Complex DNA Profiles for the Undergraduate Laboratory

ERIC Educational Resources Information Center

Kass, David H.

2007-01-01

Deoxyribonucleic acid (DNA) profiles can be generated by a variety of techniques incorporating different types of DNA markers. Simple methods are commonly utilized in the undergraduate laboratory, but with certain drawbacks. In this article, the author presents an advancement of the "Alu" dimorphism technique involving two tetraplex polymerase…

A Monte Carlo Simulation of Brownian Motion in the Freshman Laboratory

ERIC Educational Resources Information Center

Anger, C. D.; Prescott, J. R.

1970-01-01

Describes a dry- lab" experiment for the college freshman laboratory, in which the essential features of Browian motion are given principles, using the Monte Carlo technique. Calculations principles, using the Monte Carlo technique. Calculations are carried out by a computation sheme based on computer language. Bibliography. (LC)

A Cost-Effective Two-Part Experiment for Teaching Introductory Organic Chemistry Techniques

ERIC Educational Resources Information Center

Sadek, Christopher M.; Brown, Brenna A.; Wan, Hayley

2011-01-01

This two-part laboratory experiment is designed to be a cost-effective method for teaching basic organic laboratory techniques (recrystallization, thin-layer chromatography, column chromatography, vacuum filtration, and melting point determination) to large classes of introductory organic chemistry students. Students are exposed to different…

A simple technique for maintaining Stimulium adults, including onchocerciasis vectors, under artificial conditions.

PubMed

Raybould, J N; Mhiddin, H K

1974-01-01

The maintenance of Simulium adults in the laboratory is necessary for many experimental investigations and is a prerequisite to laboratory colonization. A simple technique for this purpose is described in which each fly is kept separately in a hole bored in a block of expanded polystyrene.

Assessment of an ELISA Laboratory Exercise

ERIC Educational Resources Information Center

Robinson, David L.; Lau, Joann M.

2012-01-01

The enzyme-linked immunosorbent assay (ELISA) is a powerful immunological technique for quantifying small amounts of compounds and has been used in research and clinical settings for years. Although there are laboratory exercises developed to introduce the ELISA technique to students, their ability to promote student learning has not been…

A Simple Photochemical Experiment for the Advanced Laboratory.

ERIC Educational Resources Information Center

Rosenfeld, Stuart M.

1986-01-01

Describes an experiment to provide students with: (1) an introduction to photochemical techniques and theory; (2) an experience with semimicro techniques; (3) an application of carbon-14 nuclear magnetic resonance; and (4) a laboratory with some qualities of a genuine experiment. These criteria are met in the photooxidation of 9,…

MATERIALS AND TECHNIQUES FOR THE LANGUAGE LABORATORY.

ERIC Educational Resources Information Center

NAJAM, EDWARD W.

THE PROCEEDINGS OF THE SECOND ANNUAL INDIANA-PURDUE LANGUAGE LABORATORY CONFERENCE ARE ORGANIZED, AFTER INTRODUCTORY STATEMENTS BY NAJAM AND LARSEN ON CONTEMPORARY TRENDS IN LANGUAGE INSTRUCTION, UNDER THREE GENERAL HEADINGS PLUS APPENDIXES. IN THE FIRST SECTION DEVOTED TO MATERIALS AND TECHNIQUES ARE ARTICLES BY HYER, GARIMALDI, EDDY, AND SMITH…

ELECTRONICS UPGRADE TO THE SAVANNAH RIVER NATIONAL LABORATORY COULOMETER FOR PLUTONIUM AND NEPTUNIUM ASSAY

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

Cordaro, J.; Holland, M.; Reeves, G.

The Savannah River Site (SRS) has the analytical measurement capability to perform high-precision plutonium concentration measurements by controlled-potential coulometry. State-of-the-art controlled-potential coulometers were designed and fabricated by the Savannah River National Laboratory and installed in the Analytical Laboratories process control laboratory. The Analytical Laboratories uses coulometry for routine accountability measurements of and for verification of standard preparations used to calibrate other plutonium measurement systems routinely applied to process control, nuclear safety, and other accountability applications. The SRNL Coulometer has a demonstrated measurement reliability of {approx}0.05% for 10 mg samples. The system has also been applied to the characterization of neptuniummore » standard solutions with a comparable reliability. The SRNL coulometer features: a patented current integration system; continuous electrical calibration versus Faraday's Constants and Ohm's Law; the control-potential adjustment technique for enhanced application of the Nernst Equation; a wide operating room temperature range; and a fully automated instrument control and data acquisition capability. Systems have been supplied to the International Atomic Energy Agency (IAEA), Russia, Japanese Atomic Energy Agency (JAEA) and the New Brunswick Laboratory (NBL). The most recent vintage of electronics was based on early 1990's integrated circuits. Many of the components are no longer available. At the request of the IAEA and the Department of State, SRNL has completed an electronics upgrade of their controlled-potential coulometer design. Three systems have built with the new design, one for the IAEA which was installed at SAL in May 2011, one system for Los Alamos National Laboratory, (LANL) and one for the SRS Analytical Laboratory. The LANL and SRS systems are undergoing startup testing with installation scheduled for this summer.« less

Evaluation of Aqueous and Powder Processing Techniques for Production of Pu-238-Fueled General Purpose Heat Sources

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

Not Available

2008-06-01

This report evaluates alternative processes that could be used to produce Pu-238 fueled General Purpose Heat Sources (GPHS) for radioisotope thermoelectric generators (RTG). Fabricating GPHSs with the current process has remained essentially unchanged since its development in the 1970s. Meanwhile, 30 years of technological advancements have been made in the fields of chemistry, manufacturing, ceramics, and control systems. At the Department of Energy’s request, alternate manufacturing methods were compared to current methods to determine if alternative fabrication processes could reduce the hazards, especially the production of respirable fines, while producing an equivalent GPHS product. An expert committee performed the evaluationmore » with input from four national laboratories experienced in Pu-238 handling.« less

Hardware-in-the-loop projector system for light detection and ranging sensor testing

NASA Astrophysics Data System (ADS)

Kim, Hajin J.; Naumann, Charles B.; Cornell, Michael C.

2012-08-01

Efforts in developing a synthetic environment for testing light detection and ranging (LADAR) sensors in a hardware-in-the-loop simulation are continuing at the Aviation and Missile Research, Engineering, and Development Center of the U.S. Army Research, Engineering and Development Command (RDECOM). Current activities have concentrated on evaluating the optical projection techniques for the LADAR synthetic environment. Schemes for generating the optical signals representing the individual pixels of the projection are of particular interest. Several approaches have been investigated and tested with emphasis on operating wavelength, intensity dynamic range and uniformity, and flexibility in pixel waveform generation. This paper will discuss some of the results from these current efforts at RDECOM's System Simulation and Development Directorate's Electro Optical Technology Development Laboratory.

The current role of on-line extraction approaches in clinical and forensic toxicology.

PubMed

Mueller, Daniel M

2014-08-01

In today's clinical and forensic toxicological laboratories, automation is of interest because of its ability to optimize processes, to reduce manual workload and handling errors and to minimize exposition to potentially infectious samples. Extraction is usually the most time-consuming step; therefore, automation of this step is reasonable. Currently, from the field of clinical and forensic toxicology, methods using the following on-line extraction techniques have been published: on-line solid-phase extraction, turbulent flow chromatography, solid-phase microextraction, microextraction by packed sorbent, single-drop microextraction and on-line desorption of dried blood spots. Most of these published methods are either single-analyte or multicomponent procedures; methods intended for systematic toxicological analysis are relatively scarce. However, the use of on-line extraction will certainly increase in the near future.

Chemistry laboratory safety manual available

NASA Technical Reports Server (NTRS)

Elsbrock, R. G.

1968-01-01

Chemistry laboratory safety manual outlines safe practices for handling hazardous chemicals and chemistry laboratory equipment. Included are discussions of chemical hazards relating to fire, health, explosion, safety equipment and procedures for certain laboratory techniques and manipulations involving glassware, vacuum equipment, acids, bases, and volatile solvents.

Analytical techniques: A compilation

NASA Technical Reports Server (NTRS)

1975-01-01

A compilation, containing articles on a number of analytical techniques for quality control engineers and laboratory workers, is presented. Data cover techniques for testing electronic, mechanical, and optical systems, nondestructive testing techniques, and gas analysis techniques.

Applications Of Measurement Techniques To Develop Small-Diameter, Undersea Fiber Optic Cables

NASA Astrophysics Data System (ADS)

Kamikawa, Neil T.; Nakagawa, Arthur T.

1984-12-01

Attenuation, strain, and optical time domain reflectometer (OTDR) measurement techniques were applied successfully in the development of a minimum-diameter, electro-optic sea floor cable. Temperature and pressure models for excess attenuation in polymer coated, graded-index fibers were investigated analytically and experimentally using these techniques in the laboratory. The results were used to select a suitable fiber for the cable. Measurements also were performed on these cables during predeployment and sea-trial testing to verify laboratory results. Application of the measurement techniques and results are summarized in this paper.

NDE of copper canisters for long-term storage of spent nuclear fuel from the Swedish nuclear power plants

NASA Astrophysics Data System (ADS)

Stepinski, Tadeusz

2003-07-01

Sweden has been intensively developing methods for long term storage of spent fuel from the nuclear power plants for twenty-five years. A dedicated research program has been initiated and conducted by the Swedish company SKB (Swedish Nuclear Fuels and Waste Management Co.). After the interim storage SKB plans to encapsulate spent nuclear fuel in copper canisters that will be placed at a deep repository located in bedrock. The canisters filled with fuel rods will be sealed by an electron beam weld. This paper presents three complementary NDE techniques used for assessing the sealing weld in copper canisters, radiography, ultrasound, and eddy current. A powerful X-ray source and a digital detector are used for the radiography. An ultrasonic array system consisting of a phased ultrasonic array and a multi-channel electronics is used for the ultrasonic examination. The array system enables electronic focusing and rapid electronic scanning eliminating the use of a complicated mechanical scanner. A specially designed eddy current probe capable of detecting small voids at the depth up to 4 mm in copper is used for the eddy current inspection. Presently, all the NDE techniques are verified in SKB's Canister Laboratory where full scale canisters are welded and examined.

The relationship between wave and geometrical optics models of coded aperture type x-ray phase contrast imaging systems

PubMed Central

Munro, Peter R.T.; Ignatyev, Konstantin; Speller, Robert D.; Olivo, Alessandro

2013-01-01

X-ray phase contrast imaging is a very promising technique which may lead to significant advancements in medical imaging. One of the impediments to the clinical implementation of the technique is the general requirement to have an x-ray source of high coherence. The radiation physics group at UCL is currently developing an x-ray phase contrast imaging technique which works with laboratory x-ray sources. Validation of the system requires extensive modelling of relatively large samples of tissue. To aid this, we have undertaken a study of when geometrical optics may be employed to model the system in order to avoid the need to perform a computationally expensive wave optics calculation. In this paper, we derive the relationship between the geometrical and wave optics model for our system imaging an infinite cylinder. From this model we are able to draw conclusions regarding the general applicability of the geometrical optics approximation. PMID:20389424

The relationship between wave and geometrical optics models of coded aperture type x-ray phase contrast imaging systems.

PubMed

Munro, Peter R T; Ignatyev, Konstantin; Speller, Robert D; Olivo, Alessandro

2010-03-01

X-ray phase contrast imaging is a very promising technique which may lead to significant advancements in medical imaging. One of the impediments to the clinical implementation of the technique is the general requirement to have an x-ray source of high coherence. The radiation physics group at UCL is currently developing an x-ray phase contrast imaging technique which works with laboratory x-ray sources. Validation of the system requires extensive modelling of relatively large samples of tissue. To aid this, we have undertaken a study of when geometrical optics may be employed to model the system in order to avoid the need to perform a computationally expensive wave optics calculation. In this paper, we derive the relationship between the geometrical and wave optics model for our system imaging an infinite cylinder. From this model we are able to draw conclusions regarding the general applicability of the geometrical optics approximation.

Atomic Layer Deposition of Silicon Nitride Thin Films: A Review of Recent Progress, Challenges, and Outlooks

PubMed Central

Meng, Xin; Byun, Young-Chul; Kim, Harrison S.; Lee, Joy S.; Lucero, Antonio T.; Cheng, Lanxia; Kim, Jiyoung

2016-01-01

With the continued miniaturization of devices in the semiconductor industry, atomic layer deposition (ALD) of silicon nitride thin films (SiNx) has attracted great interest due to the inherent benefits of this process compared to other silicon nitride thin film deposition techniques. These benefits include not only high conformality and atomic-scale thickness control, but also low deposition temperatures. Over the past 20 years, recognition of the remarkable features of SiNx ALD, reinforced by experimental and theoretical investigations of the underlying surface reaction mechanism, has contributed to the development and widespread use of ALD SiNx thin films in both laboratory studies and industrial applications. Such recognition has spurred ever-increasing opportunities for the applications of the SiNx ALD technique in various arenas. Nevertheless, this technique still faces a number of challenges, which should be addressed through a collaborative effort between academia and industry. It is expected that the SiNx ALD will be further perceived as an indispensable technique for scaling next-generation ultra-large-scale integration (ULSI) technology. In this review, the authors examine the current research progress, challenges and future prospects of the SiNx ALD technique. PMID:28774125

[Laboratory medicine in the obligatory postgraduate clinical training system--common clinical training program in the department of laboratory medicine in our prefectural medical university hospital].

PubMed

Okamoto, Yasuyuki

2003-04-01

I propose a postgraduate common clinical training program to be provided by the department of laboratory medicine in our prefectural medical university hospital. The program has three purposes: first, mastering basic laboratory tests; second, developing the skills necessary to accurately interpret laboratory data; third, learning specific techniques in the field of laboratory medicine. For the first purpose, it is important that medical trainees perform testing of their own patients at bedside or in the central clinical laboratory. When testing at the central clinical laboratory, instruction by expert laboratory technicians is helpful. The teaching doctors in the department of laboratory medicine are asked to advise the trainees on the interpretation of data. Consultation will be received via interview or e-mail. In addition, the trainees can participate in various conferences, seminars, and meetings held at the central clinical laboratory. Finally, in order to learn specific techniques in the field of laboratory medicine, several special courses lasting a few months will be prepared. I think this program should be closely linked to the training program in internal medicine.

Laboratory studies, analysis, and interpretation of the spectra of hydrocarbons present in planetary atmospheres including cyanoacetylene, acetylene, propane, and ethane

NASA Technical Reports Server (NTRS)

Blass, William E.; Daunt, Stephen J.; Peters, Antoni V.; Weber, Mark C.

1990-01-01

Combining broadband Fourier transform spectrometers (FTS) from the McMath facility at NSO and from NRC in Ottawa and narrow band TDL data from the laboratories with computational physics techniques has produced a broad range of results for the study of planetary atmospheres. Motivation for the effort flows from the Voyager/IRIS observations and the needs of Voyager analysis for laboratory results. In addition, anticipation of the Cassini mission adds incentive to pursue studies of observed and potentially observable constituents of planetary atmospheres. Current studies include cyanoacetylene, acetylene, propane, and ethane. Particular attention is devoted to cyanoacetylen (H3CN) which is observed in the atmosphere of Titan. The results of a high resolution infrared laboratory study of the line positions of the 663, 449, and 22.5/cm fundamental bands are presented. Line position, reproducible to better than 5 MHz for the first two bands, are available for infrared astrophysical searches. Intensity and broadening studies are in progress. Acetylene is a nearly ubiquitous atmospheric constituent of the outer planets and Titan due to the nature of methane photochemistry. Results of ambient temperature absolute intensity measurements are presented for the fundamental and two two-quantum hotband in the 730/cm region. Low temperature hotband intensity and linewidth measurements are planned.

Performance evaluation of elemental analysis/isotope ratio mass spectrometry methods for the determination of the D/H ratio in tetramethylurea and other compounds--results of a laboratory inter-comparison.

PubMed

Bréas, Olivier; Thomas, Freddy; Zeleny, Reinhard; Calderone, Giovanni; Jamin, Eric; Guillou, Claude

2007-01-01

Tetramethylurea (TMU) with a certified D/H ratio is the internal standard for Site-specific Natural Isotope Fractionation measured by Nuclear Magnetic Resonance (SNIF-NMR) analysis of wine ethanol for detection of possible adulterations (Commission Regulation 2676/90). A new batch of a TMU certified reference material (CRM) is currently being prepared. Whereas SNIF-NMR has been employed up to now, Elemental Analysis/Isotope Ratio Mass Spectrometry ((2)H-EA-IRMS) was envisaged as the method of choice for value assignment of the new CRM, as more precise (better repeatable) data might be obtained, resulting in lower uncertainty of the certified value. In order to evaluate the accuracy and intra- and inter-laboratory reproducibility of (2)H-EA-IRMS methods, a laboratory inter-comparison was carried out by analysing TMU and other organic compounds, as well as some waters. The results revealed that experienced laboratories are capable of generating robust and well comparable data, which highlights the emerging potential of IRMS in food authenticity testing. However, a systematic bias between IRMS and SNIF-NMR reference data was observed for TMU; this lack of data consistency rules out the (2)H-IRMS technique for the characterisation measurement of the new TMU CRM.

Laboratory studies in ultraviolet solar physics

NASA Technical Reports Server (NTRS)

Parkinson, W. H.; Kohl, J. L.; Gardner, L. D.; Raymond, J. C.; Smith, P. L.

1991-01-01

The research activity comprised the measurement of basic atomic processes and parameters which relate directly to the interpretation of solar ultraviolet observations and to the development of comprehensive models of the component structures of the solar atmosphere. The research was specifically directed towards providing the relevant atomic data needed to perform and to improve solar diagnostic techniques which probe active and quiet portions of the solar chromosphere, the transition zone, the inner corona, and the solar wind acceleration regions of the extended corona. The accuracy with which the physical conditions in these structures can be determined depends directly on the accuracy and completeness of the atomic and molecular data. These laboratory data are used to support the analysis programs of past and current solar observations (e.g., the Orbiting solar Observatories, the Solar Maximum Mission, the Skylab Apollo Telescope Mount, and the Naval Research Laboratory's rocket-borne High Resolution Telescope and Spectrograph). In addition, we attempted to anticipate the needs of future space-borne solar studies such as from the joint ESA/NASA Solar and Heliospheric Observatory (SOHO) spacecraft. Our laboratory activities stressed two categories of study: (1) the measurement of absolute rate coefficients for dielectronic recombination and electron impact excitation; and (2) the measurement of atomic transition probabilities for solar density diagnostics. A brief summary of the research activity is provided.

Artificial production and natural breeding of the endangered frog species Odorrana ishikawae, with special reference to fauna conservation in the laboratory.

PubMed

Sumida, Masayuki; Satou, Naoki; Yoshikawa, Natsuhiko; Kurabayashi, Atsushi; Islam, Mohammed Mafizul; Igawa, Takeshi; Oumi, Shohei; Katsuren, Seiki; Ota, Hidetoshi; Shintani, Nozomi; Fukuniwa, Hiroko; Sano, Naomi; Fujii, Tamotsu

2011-11-01

Odorrana ishikawae is listed as a class IB endangered species in the IUCN Red List and is protected by law in both Okinawa and Kagoshima Prefectures, Japan. Here, in an effort to help effectively preserve the genetic diversity of this endangered species in the laboratory, we tested a farming technique involving the artificial breeding of frogs, and also promoted natural breeding in the laboratory. Field-caught male/female pairs of the Amami and Okinawa Island populations were artificially bred using an artificial insemination method in the 2004, 2006, and 2008 breeding seasons (March to April). Although fewer than 50% of the inseminated eggs achieved metamorphosis, approximately 500, 300, and 250 offspring from the three respective trials are currently being raised in the laboratory. During the 2009 and 2010 breeding seasons, second-generation offspring were produced by the natural mating activities of the first offspring derived from the two artificial matings in 2004. The findings and the methods presented here appear to be applicable to the temporary protection of genetic diversity of local populations in which the number of individuals has decreased or the environmental conditions have worsened to levels that frogs are unable to survive by themselves.

Role and Evaluation of Interlaboratory Comparison Results in Laboratory Accreditation

NASA Astrophysics Data System (ADS)

Bode, P.

2008-08-01

Participation in interlaboratory comparisons provides laboratories an opportunity for independent assessment of their analytical performance, both in absolute way and in comparison with those by other techniques. However, such comparisons are hindered by differences in the way laboratories participate, e.g. at best measurement capability or under routine conditions. Neutron activation analysis laboratories, determining total mass fractions, often see themselves classified as `outliers' since the majority of other participants employ techniques with incomplete digestion methods. These considerations are discussed in relation to the way results from interlaboratory comparisons are evaluated by accreditation bodies following the requirements of Clause 5.9.1 of the ISO/IEC 17025:2005. The discussion and conclusions come largely forth from experiences in the author's own laboratory.

Zero-gravity cloud physics laboratory: Candidate experiments definition and preliminary concept studies

NASA Technical Reports Server (NTRS)

Eaton, L. R.; Greco, R. V.; Hollinden, A. B.

1973-01-01

The candidate definition studies on the zero-g cloud physics laboratory are covered. This laboratory will be an independent self-contained shuttle sortie payload. Several critical technology areas have been identified and studied to assure proper consideration in terms of engineering requirements for the final design. Areas include chambers, gas and particle generators, environmental controls, motion controls, change controls, observational techniques, and composition controls. This unique laboratory will allow studies to be performed without mechanical, aerodynamics, electrical, or other type techniques to support the object under study. This report also covers the candidate experiment definitions, chambers and experiment classes, laboratory concepts and plans, special supporting studies, early flight opportunities and payload planning data for overall shuttle payload requirements assessments.

Indirect methods for reference interval determination - review and recommendations.

PubMed

Jones, Graham R D; Haeckel, Rainer; Loh, Tze Ping; Sikaris, Ken; Streichert, Thomas; Katayev, Alex; Barth, Julian H; Ozarda, Yesim

2018-04-19

Reference intervals are a vital part of the information supplied by clinical laboratories to support interpretation of numerical pathology results such as are produced in clinical chemistry and hematology laboratories. The traditional method for establishing reference intervals, known as the direct approach, is based on collecting samples from members of a preselected reference population, making the measurements and then determining the intervals. An alternative approach is to perform analysis of results generated as part of routine pathology testing and using appropriate statistical techniques to determine reference intervals. This is known as the indirect approach. This paper from a working group of the International Federation of Clinical Chemistry (IFCC) Committee on Reference Intervals and Decision Limits (C-RIDL) aims to summarize current thinking on indirect approaches to reference intervals. The indirect approach has some major potential advantages compared with direct methods. The processes are faster, cheaper and do not involve patient inconvenience, discomfort or the risks associated with generating new patient health information. Indirect methods also use the same preanalytical and analytical techniques used for patient management and can provide very large numbers for assessment. Limitations to the indirect methods include possible effects of diseased subpopulations on the derived interval. The IFCC C-RIDL aims to encourage the use of indirect methods to establish and verify reference intervals, to promote publication of such intervals with clear explanation of the process used and also to support the development of improved statistical techniques for these studies.

An In-Rush Current Suppression Technique for the Solid-State Transfer Switch System

NASA Astrophysics Data System (ADS)

Cheng, Po-Tai; Chen, Yu-Hsing

More and more utility companies provide dual power feeders as a premier service of high power quality and reliability. To take advantage of this, the solid-state transfer switch (STS) is adopted to protect the sensitive load against the voltage sag. However, the fast transfer process may cause in-rush current on the load-side transformer due to the resulting DC-offset in its magnetic flux as the load-transfer is completed. The in-rush current can reach 2∼6 p.u. and it may trigger the over-current protections on the power feeder. This paper develops a flux estimation scheme and a thyristor gating scheme based on the impulse commutation bridge STS (ICBSTS) to minimize the DC-offset on the magnetic flux. By sensing the line voltages of both feeders, the flux estimator can predict the peak transient flux linkage at the moment of load-transfer and evaluate a suitable moment for the transfer to minimize the in-rush current. Laboratory test results are presented to validate the performance of the proposed system.

Live births achieved via IVF are increased by improvements in air quality and laboratory environment.

PubMed

Heitmann, Ryan J; Hill, Micah J; James, Aidita N; Schimmel, Tim; Segars, James H; Csokmay, John M; Cohen, Jacques; Payson, Mark D

2015-09-01

Infertility is a common disease, which causes many couples to seek treatment with assisted reproduction techniques. Many factors contribute to successful assisted reproduction technique outcomes. One important factor is laboratory environment and air quality. Our facility had the unique opportunity to compare consecutively used, but separate assisted reproduction technique laboratories, as a result of a required move. Environmental conditions were improved by strategic engineering designs. All other aspects of the IVF laboratory, including equipment, physicians, embryologists, nursing staff and protocols, were kept constant between facilities. Air quality testing showed improved air quality at the new IVF site. Embryo implantation (32.4% versus 24.3%; P < 0.01) and live birth (39.3% versus 31.8%, P < 0.05) were significantly increased in the new facility compared with the old facility. More patients met clinical criteria and underwent mandatory single embryo transfer on day 5 leading to both a reduction in multiple gestation pregnancies and increased numbers of vitrified embryos per patient with supernumerary embryos available. Improvements in IVF laboratory conditions and air quality had profound positive effects on laboratory measures and patient outcomes. This study further strengthens the importance of the laboratory environment and air quality in the success of an IVF programme. Published by Elsevier Ltd.

A laboratory demonstration of high-resolution hard X-ray and gamma-ray imaging using Fourier-transform techniques

NASA Technical Reports Server (NTRS)

Palmer, David; Prince, Thomas A.

1987-01-01

A laboratory imaging system has been developed to study the use of Fourier-transform techniques in high-resolution hard X-ray and gamma-ray imaging, with particular emphasis on possible applications to high-energy astronomy. Considerations for the design of a Fourier-transform imager and the instrumentation used in the laboratory studies is described. Several analysis methods for image reconstruction are discussed including the CLEAN algorithm and maximum entropy methods. Images obtained using these methods are presented.

An Electronics "Unit Laboratory"

ERIC Educational Resources Information Center

Davies, E. R.; Penton, S. J.

1976-01-01

Describes a laboratory teaching technique in which a single topic (in this case, bipolar junction transistors) is studied over a period of weeks under the supervision of one staff member, who also designs the laboratory work. (MLH)

8th Spacecraft Charging Technology Conference

NASA Technical Reports Server (NTRS)

Minor, J. L. (Compiler)

2004-01-01

The 8th Spacecraft Charging Technology Conference was held in Huntsville, Alabama, October 20-24, 2003. Hosted by NASA s Space Environments and Effects (SEE) Program and co-sponsored by the Air Force Research Laboratory (AFRL) and the European Space Agency (ESA), the 2003 conference saw attendance from eleven countries with over 65 oral papers and 18 poster papers. Presentation topics highlighted the latest in spacecraft charging mitigation techniques and on-orbit investigations, including: Plasma Propulsion and Tethers; Ground Testing Techniques; Interactions of Spacecraft and Systems With the Natural and Induced Plasma Environment; Materials Characterizations; Models and Computer Simulations; Environment Specifications; Current Collection and Plasma Probes in Space Plasmas; On-Orbit Investigations. A round-table discussion of international standards regarding electrostatic discharge (ESD) testing was also held with the promise of continued discussions in the off years and an official continuation at the next conference.

Helicobacter pylori Detection and Antimicrobial Susceptibility Testing

PubMed Central

Mégraud, Francis; Lehours, Philippe

2007-01-01

The discovery of Helicobacter pylori in 1982 was the starting point of a revolution concerning the concepts and management of gastroduodenal diseases. It is now well accepted that the most common stomach disease, peptic ulcer disease, is an infectious disease, and all consensus conferences agree that the causative agent, H. pylori, must be treated with antibiotics. Furthermore, the concept emerged that this bacterium could be the trigger of various malignant diseases of the stomach, and it is now a model for chronic bacterial infections causing cancer. Most of the many different techniques involved in diagnosis of H. pylori infection are performed in clinical microbiology laboratories. The aim of this article is to review the current status of these methods and their application, highlighting the important progress which has been made in the past decade. Both invasive and noninvasive techniques will be reviewed. PMID:17428887

The Protein Information Management System (PiMS): a generic tool for any structural biology research laboratory

PubMed Central

Morris, Chris; Pajon, Anne; Griffiths, Susanne L.; Daniel, Ed; Savitsky, Marc; Lin, Bill; Diprose, Jonathan M.; Wilter da Silva, Alan; Pilicheva, Katya; Troshin, Peter; van Niekerk, Johannes; Isaacs, Neil; Naismith, James; Nave, Colin; Blake, Richard; Wilson, Keith S.; Stuart, David I.; Henrick, Kim; Esnouf, Robert M.

2011-01-01

The techniques used in protein production and structural biology have been developing rapidly, but techniques for recording the laboratory information produced have not kept pace. One approach is the development of laboratory information-management systems (LIMS), which typically use a relational database schema to model and store results from a laboratory workflow. The underlying philosophy and implementation of the Protein Information Management System (PiMS), a LIMS development specifically targeted at the flexible and unpredictable workflows of protein-production research laboratories of all scales, is described. PiMS is a web-based Java application that uses either Postgres or Oracle as the underlying relational database-management system. PiMS is available under a free licence to all academic laboratories either for local installation or for use as a managed service. PMID:21460443

The Protein Information Management System (PiMS): a generic tool for any structural biology research laboratory.

PubMed

Morris, Chris; Pajon, Anne; Griffiths, Susanne L; Daniel, Ed; Savitsky, Marc; Lin, Bill; Diprose, Jonathan M; da Silva, Alan Wilter; Pilicheva, Katya; Troshin, Peter; van Niekerk, Johannes; Isaacs, Neil; Naismith, James; Nave, Colin; Blake, Richard; Wilson, Keith S; Stuart, David I; Henrick, Kim; Esnouf, Robert M

2011-04-01

The techniques used in protein production and structural biology have been developing rapidly, but techniques for recording the laboratory information produced have not kept pace. One approach is the development of laboratory information-management systems (LIMS), which typically use a relational database schema to model and store results from a laboratory workflow. The underlying philosophy and implementation of the Protein Information Management System (PiMS), a LIMS development specifically targeted at the flexible and unpredictable workflows of protein-production research laboratories of all scales, is described. PiMS is a web-based Java application that uses either Postgres or Oracle as the underlying relational database-management system. PiMS is available under a free licence to all academic laboratories either for local installation or for use as a managed service.

Radar image enhancement and simulation as an aid to interpretation and training

NASA Technical Reports Server (NTRS)

Frost, V. S.; Stiles, J. A.; Holtzman, J. C.; Dellwig, L. F.; Held, D. N.

1980-01-01

Greatly increased activity in the field of radar image applications in the coming years demands that techniques of radar image analysis, enhancement, and simulation be developed now. Since the statistical nature of radar imagery differs from that of photographic imagery, one finds that the required digital image processing algorithms (e.g., for improved viewing and feature extraction) differ from those currently existing. This paper addresses these problems and discusses work at the Remote Sensing Laboratory in image simulation and processing, especially for systems comparable to the formerly operational SEASAT synthetic aperture radar.

Multiple-access phased array antenna simulator for a digital beam-forming system investigation

NASA Technical Reports Server (NTRS)

Kerczewski, Robert J.; Yu, John; Walton, Joanne C.; Perl, Thomas D.; Andro, Monty; Alexovich, Robert E.

1992-01-01

Future versions of data relay satellite systems are currently being planned by NASA. Being given consideration for implementation are on-board digital beamforming techniques which will allow multiple users to simultaneously access a single S-band phased array antenna system. To investigate the potential performance of such a system, a laboratory simulator has been developed at NASA's Lewis Research Center. This paper describes the system simulator, and in particular, the requirements, design and performance of a key subsystem, the phased array antenna simulator, which provides realistic inputs to the digital processor including multiple signals, noise, and nonlinearities.

Multiple-access phased array antenna simulator for a digital beam forming system investigation

NASA Technical Reports Server (NTRS)

Kerczewski, Robert J.; Yu, John; Walton, Joanne C.; Perl, Thomas D.; Andro, Monty; Alexovich, Robert E.

1992-01-01

Future versions of data relay satellite systems are currently being planned by NASA. Being given consideration for implementation are on-board digital beamforming techniques which will allow multiple users to simultaneously access a single S-band phased array antenna system. To investigate the potential performance of such a system, a laboratory simulator has been developed at NASA's Lewis Research Center. This paper describes the system simulator, and in particular, the requirements, design, and performance of a key subsystem, the phased array antenna simulator, which provides realistic inputs to the digital processor including multiple signals, noise, and nonlinearities.

Photovoltaic module hot spot durability design and test methods

NASA Technical Reports Server (NTRS)

Arnett, J. C.; Gonzalez, C. C.

1981-01-01

As part of the Jet Propulsion Laboratory's Low-Cost Solar Array Project, the susceptibility of fat-plate modules to hot-spot problems is investigated. Hot-spot problems arise in modules when the cells become back-biased and operate in the negative-voltage quadrant, as a result of short-circuit current mismatch, cell cracking or shadowing. The details of a qualification test for determining the capability of modules of surviving field hot-spot problems and typical results of this test are presented. In addition, recommended circuit-design techniques for improving the module and array reliability with respect to hot-spot problems are presented.

Apparatus for in situ prediction of the thermal conductivity of fiberglass batts using acoustic propagation constant

NASA Astrophysics Data System (ADS)

Tinianov, Brandon D.; Nakagawa, Masami; Muñoz, David R.

2006-02-01

This article describes a novel technique for the measurement of the thermal conductivity of low-density (12-18kg/m3) fiberglass insulation and other related fibrous insulation materials using a noninvasive acoustic apparatus. The experimental method is an extension of earlier acoustic methods based upon the evaluation of the propagation constant from the acoustic pressure transfer function across the test material. To accomplish this, an analytical model is employed that describes the behavior of sound waves at the outlet of a baffled waveguide. The model accounts for the behavior of the mixed impedance interface introduced by the test material. Current results show that the technique is stable for a broad range of absorber thicknesses and densities. Experimental results obtained in the laboratory show excellent correlation between the thermal conductivity and both the real and imaginary components of the propagation constant. Correlation of calculated propagation constant magnitude versus measured thermal conductivity gave an R2 of 0.94 for the bulk density range (12-18kg/m3) typical for manufactured fiberglass batt materials. As an improvement to earlier acoustic techniques, measurement is now possible in noisy manufacturing environments with a moving test material. Given the promise of such highly correlated measurements in a robust method, the acoustic technique is well suited to continuously measure the thermal conductivity of the material during its production, replacing current expensive off-line methods. Test cycle time is reduced from hours to seconds.

An Investigative Graduate Laboratory Course for Teaching Modern DNA Techniques

ERIC Educational Resources Information Center

de Lencastre, Alexandre; Torello, A. Thomas; Keller, Lani C.

2017-01-01

This graduate-level DNA methods laboratory course is designed to model a discovery-based research project and engages students in both traditional DNA analysis methods and modern recombinant DNA cloning techniques. In the first part of the course, students clone the "Drosophila" ortholog of a human disease gene of their choosing using…

TECHNIQUES OF TAPE PREPARATION AND DUPLICATION, WITH SUGGESTIONS FOR A LANGUAGE LABORATORY.

ERIC Educational Resources Information Center

Kansas State Dept. of Public Instruction, Topeka.

PART ONE OF THIS BULLETIN PROVIDES HELP IN THE TWO CRITICAL AREAS OF MASTER TAPE PREPARATION AND DUPLICATION. SUPPLEMENTED BY NUMEROUS PHOTOGRAPHS AND DIAGRAMS OF EQUIPMENT AND DUPLICATION TECHNIQUES, THE BULLETIN DESCRIBES MASTER PROGRAM DUPLICATION USING LANGUAGE LABORATORY EQUIPMENT, A PROFESSIONAL MASS DUPLICATOR, A TAPE RECORDER, A RECORD…

A Size Exclusion Chromatography Laboratory with Unknowns for Introductory Students

ERIC Educational Resources Information Center

McIntee, Edward J.; Graham, Kate J.; Colosky, Edward C.; Jakubowski, Henry V.

2015-01-01

Size exclusion chromatography is an important technique in the separation of biological and polymeric samples by molecular weight. While a number of laboratory experiments have been published that use this technique for the purification of large molecules, this is the first report of an experiment that focuses on purifying an unknown small…

Studies on the laboratory diagnosis of human filariasis: Preliminary communication

PubMed Central

Goldsmid, J. M.

1970-01-01

Five laboratory methods used for the recovery of microfilariae from the blood were compared for efficiency of recovery and time involved. The methods used were thin blood films, thick blood films, wet preparations, the Polyvidone technique, and the microhaematocrit technique. The last proved superior in both efficiency and saving time. Images PMID:5529998

An Enzymatic Clinical Chemistry Laboratory Experiment Incorporating an Introduction to Mathematical Method Comparison Techniques

ERIC Educational Resources Information Center

Duxbury, Mark

2004-01-01

An enzymatic laboratory experiment based on the analysis of serum is described that is suitable for students of clinical chemistry. The experiment incorporates an introduction to mathematical method-comparison techniques in which three different clinical glucose analysis methods are compared using linear regression and Bland-Altman difference…

USING THE LANGUAGE LABORATORY.

ERIC Educational Resources Information Center

LADU, TORA TUVE

TO ENCOURAGE UTILIZATION OF THE LANGUAGE LABORATORY AS A TEACHING TECHNIQUE, THIS BULLETIN DESCRIBES SUCH POSSIBLE USES OF THE LABORATORY AS PROGRAMING LESSONS, RECORDING, AND TESTING LANGUAGE SKILL DEVELOPMENT. ONE OF THE MOST IMPORTANT FUNCTIONS OF THE LABORATORY IS THE PATTERN DRILL, DESCRIBED HERE FOR FRENCH, GERMAN, AND SPANISH. EXAMPLES ARE…

Accuracy of trace element determinations in alternate fuels

NASA Technical Reports Server (NTRS)

Greenbauer-Seng, L. A.

1980-01-01

NASA-Lewis Research Center's work on accurate measurement of trace level of metals in various fuels is presented. The differences between laboratories and between analytical techniques especially for concentrations below 10 ppm, are discussed, detailing the Atomic Absorption Spectrometry (AAS) and DC Arc Emission Spectrometry (dc arc) techniques used by NASA-Lewis. Also presented is the design of an Interlaboratory Study which is considering the following factors: laboratory, analytical technique, fuel type, concentration and ashing additive.

A novel method for determining calibration and behavior of PVDF ultrasonic hydrophone probes in the frequency range up to 100 MHz.

PubMed

Bleeker, H J; Lewin, P A

2000-01-01

A new calibration technique for PVDF ultrasonic hydrophone probes is described. Current implementation of the technique allows determination of hydrophone frequency response between 2 and 100 MHz and is based on the comparison of theoretically predicted and experimentally determined pressure-time waveforms produced by a focused, circular source. The simulation model was derived from the time domain algorithm that solves the non linear KZK (Khokhlov-Zabolotskaya-Kuznetsov) equation describing acoustic wave propagation. The calibration technique data were experimentally verified using independent calibration procedures in the frequency range from 2 to 40 MHz using a combined time delay spectrometry and reciprocity approach or calibration data provided by the National Physical Laboratory (NPL), UK. The results of verification indicated good agreement between the results obtained using KZK and the above-mentioned independent calibration techniques from 2 to 40 MHz, with the maximum discrepancy of 18% at 30 MHz. The frequency responses obtained using different hydrophone designs, including several membrane and needle probes, are presented, and it is shown that the technique developed provides a desirable tool for independent verification of primary calibration techniques such as those based on optical interferometry. Fundamental limitations of the presented calibration method are also examined.

Microsurgical techniques of anastomosis of the fallopian tubes.

PubMed

Smith, R N; Minkler, D

1978-01-01

Microsurgical techniques of anastomosis of the fallopian tubes have been studied. This paper considers the present state of the art of sterilization reversal, the training and equipment required, the potential for the diffusion of knowledge concerning reversal techniques, and the implication of current research in reversibility of sterilization for the practicing gynecologist. A preoperative study should be done on any candidate for a procedure to restore patency to the fallopian tubes to rule out other possible causes of infertility. Also, preoperative counseling should include both partners. The operating microscope offers a great advantage in the repair of several types of tubal obstruction. Midsegment end-to-end anastomosis is carried out by 1st injecting a dye into the cavity to locate the area of obstruction. The area is excised using microdissection and the fallopian tube checked for patency with the dye solution. Anastomosis is accomplished by opposing the miscularis of the tube, avoiding the mucosa. 4 sutures are usually adequate for closure. Most feel that postoperative hydrotubation is of some value in monitoring tubal patency. An organized training program in a microsurgical laboratory is the prefered way for learning the techniques. Long-term results of the microsurgical techniques for tubal anastomosis are encouraging and represent an improvement over macroscopic techniques previously reported.

A Review of Gene Knockout Strategies for Microbial Cells.

PubMed

Tang, Phooi Wah; Chua, Pooi San; Chong, Shiue Kee; Mohamad, Mohd Saberi; Choon, Yee Wen; Deris, Safaai; Omatu, Sigeru; Corchado, Juan Manuel; Chan, Weng Howe; Rahim, Raha Abdul

2015-01-01

Predicting the effects of genetic modification is difficult due to the complexity of metabolic net- works. Various gene knockout strategies have been utilised to deactivate specific genes in order to determine the effects of these genes on the function of microbes. Deactivation of genes can lead to deletion of certain proteins and functions. Through these strategies, the associated function of a deleted gene can be identified from the metabolic networks. The main aim of this paper is to review the available techniques in gene knockout strategies for microbial cells. The review is done in terms of their methodology, recent applications in microbial cells. In addition, the advantages and disadvantages of the techniques are compared and discuss and the related patents are also listed as well. Traditionally, gene knockout is done through wet lab (in vivo) techniques, which were conducted through laboratory experiments. However, these techniques are costly and time consuming. Hence, various dry lab (in silico) techniques, where are conducted using computational approaches, have been developed to surmount these problem. The development of numerous techniques for gene knockout in microbial cells has brought many advancements in the study of gene functions. Based on the literatures, we found that the gene knockout strategies currently used are sensibly implemented with regard to their benefits.

A 13-Week Research-Based Biochemistry Laboratory Curriculum

ERIC Educational Resources Information Center

Lefurgy, Scott T.; Mundorff, Emily C.

2017-01-01

Here, we present a 13-week research-based biochemistry laboratory curriculum designed to provide the students with the experience of engaging in original research while introducing foundational biochemistry laboratory techniques. The laboratory experience has been developed around the directed evolution of an enzyme chosen by the instructor, with…

Manual of Basic Techniques for a Health Laboratory.

ERIC Educational Resources Information Center

World Health Organization, Geneva (Switzerland).

Described are basic laboratory methods for diagnosing and investigating diseases of importance to developing countries. Intended primarily for the training of technicians who will work in peripheral laboratories, the manual is designed so that student laboratory assistants can be taught to use it with minimal supervision from a teacher. The…

Investigation of the Degradation Mechanisms of a Variety of Organic Photovoltaic Devices by Combination of Imaging Techniques—the ISOS-3Inter-laboratory Collaboration

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

Germack D.; Rosch, R.; Tanenbaum, D.M.

2012-04-01

The investigation of degradation of seven distinct sets (with a number of individual cells of n {ge} 12) of state of the art organic photovoltaic devices prepared by leading research laboratories with a combination of imaging methods is reported. All devices have been shipped to and degraded at Risoe DTU up to 1830 hours in accordance with established ISOS-3 protocols under defined illumination conditions. Imaging of device function at different stages of degradation was performed by laser-beam induced current (LBIC) scanning; luminescence imaging, specifically photoluminescence (PLI) and electroluminescence (ELI); as well as by lock-in thermography (LIT). Each of the imagingmore » techniques exhibits its specific advantages with respect to sensing certain degradation features, which will be compared and discussed here in detail. As a consequence, a combination of several imaging techniques yields very conclusive information about the degradation processes controlling device function. The large variety of device architectures in turn enables valuable progress in the proper interpretation of imaging results - hence revealing the benefits of this large scale cooperation in making a step forward in the understanding of organic solar cell aging and its interpretation by state-of-the-art imaging methods.« less

Acoustic Methods to Monitor Protein Crystallization and to Detect Protein Crystals in Suspensions of Agarose and Lipidic Cubic Phase.

PubMed

Ericson, Daniel L; Yin, Xingyu; Scalia, Alexander; Samara, Yasmin N; Stearns, Richard; Vlahos, Harry; Ellson, Richard; Sweet, Robert M; Soares, Alexei S

2016-02-01

Improvements needed for automated crystallography include crystal detection and crystal harvesting. A technique that uses acoustic droplet ejection to harvest crystals was previously reported. Here a method is described for using the same acoustic instrument to detect protein crystals and to monitor crystal growth. Acoustic pulses were used to monitor the progress of crystallization trials and to detect the presence and location of protein crystals. Crystals were detected, and crystallization was monitored in aqueous solutions and in lipidic cubic phase. Using a commercially available acoustic instrument, crystals measuring ~150 µm or larger were readily detected. Simple laboratory techniques were used to increase the sensitivity to 50 µm by suspending the crystals away from the plastic surface of the crystallization plate. This increased the sensitivity by separating the strong signal generated by the plate bottom that can mask the signal from small protein crystals. It is possible to further boost the acoustic reflection from small crystals by reducing the wavelength of the incident sound pulse, but our current instrumentation does not allow this option. In the future, commercially available sound-emitting transducers with a characteristic frequency near 300 MHz should detect and monitor the growth of individual 3 µm crystals. © 2015 Society for Laboratory Automation and Screening.

Evaluation of Euthanasia Techniques for an Invertebrate Species, Land Snails (Succinea putris).

PubMed

Gilbertson, Cody R; Wyatt, Jeffrey D

2016-01-01

The euthanasia of invertebrates used in scientific investigations poses unanswered questions regarding the rapid induction of unconsciousness with minimal distress and pain. Relative to vertebrates, invertebrates' sensory experience of pain, nociception, and physiologic response to aversive stimuli are poorly characterized. The scientific communities in the European Union, Canada, United States, Australia, and New Zealand join in consensus regarding the need to address alleviation of pain and distress in cephalopods (octopus, squid, and so forth), which have the best-characterized nervous system among invertebrates. In the current study, we evaluated various euthanasia techniques in a terrestrial gastropod species, with priority on animal wellbeing, scientific variability, feasibility in both field and laboratory settings, and acceptability by personnel. In addition, we demonstrated that the 2-step method of euthanasia described in the AVMA Guidelines as acceptable for aquatic invertebrates is effective for terrestrial snails and meets all welfare and scientific requirements. This 2-step method first induces anesthesia by immersion in 5% ethanol (laboratory-grade ethanol or beer) followed by immersion in a euthanizing and tissue-preserving solution of 70% to 95% ethanol or 10% neutral buffered formalin. Furthermore, alternative methods of euthanasia for terrestrial snails commonly used in field research, such as live immersion in concentrated ethanol or formalin, were shown to be unacceptable.

Evaluation of Euthanasia Techniques for an Invertebrate Species, Land Snails (Succinea putris)

PubMed Central

Gilbertson, Cody R; Wyatt, Jeffrey D

2016-01-01

The euthanasia of invertebrates used in scientific investigations poses unanswered questions regarding the rapid induction of unconsciousness with minimal distress and pain. Relative to vertebrates, invertebrates’ sensory experience of pain, nociception, and physiologic response to aversive stimuli are poorly characterized. The scientific communities in the European Union, Canada, United States, Australia, and New Zealand join in consensus regarding the need to address alleviation of pain and distress in cephalopods (octopus, squid, and so forth), which have the best-characterized nervous system among invertebrates. In the current study, we evaluated various euthanasia techniques in a terrestrial gastropod species, with priority on animal wellbeing, scientific variability, feasibility in both field and laboratory settings, and acceptability by personnel. In addition, we demonstrated that the 2-step method of euthanasia described in the AVMA Guidelines as acceptable for aquatic invertebrates is effective for terrestrial snails and meets all welfare and scientific requirements. This 2-step method first induces anesthesia by immersion in 5% ethanol (laboratory-grade ethanol or beer) followed by immersion in a euthanizing and tissue-preserving solution of 70% to 95% ethanol or 10% neutral buffered formalin. Furthermore, alternative methods of euthanasia for terrestrial snails commonly used in field research, such as live immersion in concentrated ethanol or formalin, were shown to be unacceptable. PMID:27657713

Laboratory measurements of modal noise on optical fiber

NASA Astrophysics Data System (ADS)

Iuzzolino, M.; Sanna, N.; Tozzi, A.; Oliva, E.

Many scientific instruments are nowadays coupled to the telescope through optical fibers. This is also the case of the current configuration of GIANO, the high resolution near infrared echelle spectrograph installed at the TNG telescope. As experienced and frequent users of the IR optical fiber, the GIANO building team decided to go deep in the characterization of the optical fiber in the IR band, and in particular to understand and analyze the fiber modal noise. This work is also a preparatory study for the future HIRES@E-ELT instrument design. This paper consists in the description of the fiber laboratory tests, and in the explanation of the results. The whole job defines a wider comprehension of the modal noise, and demonstrates the existence of two aspects influencing this noise. The first one, well known in literature, refers to the interferences between the fiber modes at the exit endface of the fiber, and it can be mitigated by mechanical scrambling techniques. The second one, unknown before, is entirely dependent on the way in which light is injected at the entrance of the fiber, and no mitigation have been observed with any classical scrambling technique (e.g. double-scramblers). These considerations apply to both ZBLAN or fused silica optical fiber, and to both circular and octagonal core shape.

A New Paradigm for Tissue Diagnostics: Tools and Techniques to Standardize Tissue Collection, Transport, and Fixation.

PubMed

Bauer, Daniel R; Otter, Michael; Chafin, David R

2018-01-01

Studying and developing preanalytical tools and technologies for the purpose of obtaining high-quality samples for histological assays is a growing field. Currently, there does not exist a standard practice for collecting, fixing, and monitoring these precious samples. There has been some advancement in standardizing collection for the highest profile tumor types, such as breast, where HER2 testing drives therapeutic decisions. This review examines the area of tissue collection, transport, and monitoring of formalin diffusion and details a prototype system that could be used to help standardize tissue collection efforts. We have surveyed recent primary literature sources and conducted several site visits to understand the most error-prone processes in histology laboratories. This effort identified errors that resulted from sample collection techniques and subsequent transport delays from the operating room (OR) to the histology laboratories. We have therefore devised a prototype sample collection and transport concept. The system consists of a custom data logger and cold transport box and takes advantage of a novel cold + warm (named 2 + 2) fixation method. This review highlights the beneficial aspects of standardizing tissue collection, fixation, and monitoring. In addition, a prototype system is introduced that could help standardize these processes and is compatible with use directly in the OR and from remote sites.

Sources of Variability in Chlorophyll Analysis by Fluorometry and by High Performance Liquid Chromatography. Chapter 22

NASA Technical Reports Server (NTRS)

VanHeukelem, Laurie; Thomas, Crystal S.; Glibert, Patricia M.

2001-01-01

The need for accurate determination of chlorophyll a (chl a) is of interest for numerous reasons. From the need for ground-truth data for remote sensing to pigment detection for laboratory experimentation, it is essential to know the accuracy of the analyses and the factors potentially contributing to variability and error. Numerous methods and instrument techniques are currently employed in the analyses of chl a. These methods range from spectrophotometric quantification, to fluorometric analysis and determination by high performance liquid chromatography. Even within the application of HPLC techniques, methods vary. Here we provide the results of a comparison among methods and provide some guidance for improving the accuracy of these analyses. These results are based on a round-robin conducted among numerous investigators, including several in the Sensor Intercomparison and Merger for Biological and Interdisciplinary Oceanic Studies (SIMBIOS) and HyCODE Programs. Our purpose here is not to present the full results of the laboratory intercalibration; those results will be presented elsewhere. Rather, here we highlight some of the major factors that may contribute to the variability observed. Specifically, we aim to assess the comparability of chl a analyses performed by fluorometry and HPLC, and we identify several factors in the analyses which may contribute disproportionately to this variability.

Will Regulatory and Financial Considerations Dampen Innovation in the Clinical Microbiology Laboratory?

PubMed

Gilligan, Peter H; Miller, Melissa B

2016-02-02

Over a million prosthetic joints are placed in patients in the United States annually. Of those that fail, 25% will be due to infection, with an estimated cost approaching 1 billion dollars. Despite the clinical and economic importance of these infections, the techniques for their detection are relatively insensitive. An innovative method for detecting these infections by using blood culture bottles (BCB) to culture specimens of periprosthetic tissue (PPT) was described in a recent article [T. N. Peel, et al., mBio 7(1):e01776-15, 2016, doi:10.1128/mBio.01776-15]. There are two potential stumbling blocks to the widespread implementation of this innovation. First, the FDA judges such an application of BCB as an "off-label use" and as such, a laboratory-developed test (LDT). LDTs are coming under greater scrutiny by the FDA and may require extensive, costly validation studies in laboratories that adopt this methodology. Second, the Center for Medicare and Medicaid Services has established a Hospital Acquired Condition Reduction Act under which institutions performing in the lowest quartile forfeit 1% of their Medicare reimbursement. Hospital-acquired infections are an important component of this quality metric. Although prosthetic joint infection (PJI) rates are not currently a hospital quality metric, given their cost and increasing frequency, it is reasonable to expect that they may become one. Will those with financial oversight allow an innovative technique that will require an expensive validation and may put the institution at risk for loss of CMS reimbursement? Copyright © 2016 Gilligan and Miller.

Comparison of Acoustic Impedance Eduction Techniques for Locally-Reacting Liners

NASA Technical Reports Server (NTRS)

Jones, M. G.; Parrott, T. L.; Watson, W. R.

2003-01-01

Typical acoustic liners used in current aircraft inlets and aft-fan ducts consist of some type of perforated facesheet bonded to a honeycomb core. A number of techniques for determining the acoustic impedance of these locallyreacting liners have been developed over the last five decades. In addition, a number of models have been developed to predict the acoustic impedance of locallyreacting liners in the presence of grazing flow, and to use that information together with aeroacoustic propagation codes to assess the noise absorption provided by these liners. These prediction models have incorporated the results from databases acquired with specific impedance eduction techniques. Thus, while these prediction models are acceptable for liners that are similar to those tested in these databases, their application to new liner configurations must be viewed with caution. The primary purpose of this paper is to provide a comparison of impedance eduction techniques that have been implemented at various aerospace research laboratories in the United States (NASA Langley Research Center, General Electric Aircraft Engines, B. F. Goodrich and Boeing). A secondary purpose is to provide data for liner configurations that extend the porosity range beyond that which has been previously used in common aircraft engine nacelles. Two sets of liners were designed to study the effects of three parameters: perforate hole diameter, facesheet thickness and porosity. These two sets of liners were constructed for testing in each of the laboratories listed above. The first set of liners was designed to fit into the NASA Langley and Boeing test facilities. The second set was designed to fit into the General Electric Aircraft Engines and B. F. Goodrich test facilities. By using the same parent material, both sets of liners were identical to within the limits of material and fabrication variability. Baseline data were obtained in the normal incidence impedance tubes at NASA Langley and B. F. Goodrich. The results were found to compare extremely well. The samples were then tested in the grazing flow ducts of each of the four laboratories. Perhaps the most significant result of these comparisons is that the educed acoustic resistances for the liners used in this study increase as the mean flow profile is modified from uniform to 3-D shear. This realization has demonstrated the need for an frequency-dependent impedance eduction technique that incorporates 3-D shear flow and is efficient.

Justification of parameters and selection of equipment for laboratory researches of a rammer's operating element dynamics in a soil foundation of a tank for oil and oil products storage

NASA Astrophysics Data System (ADS)

Gruzin, A. V.; Gruzin, V. V.; Shalay, V. V.

2017-08-01

The development of technology for a directional soil compaction of tank foundations for oil and oil products storage is a relevant problem which solution will enable simultaneously provide required operational characteristics of a soil foundation and reduce time and material costs to prepare the foundation. The impact dynamics of rammers' operating elements on the soil foundation is planned to specify in the course of laboratory studies. A specialized technique is developed to justify the parameters and select the equipment for laboratory researches. The usage of this technique enabled us to calculate dimensions of the models, of a test bench and specifications of the recording equipment, and a lighting system. The necessary equipment for laboratory studies was selected. Preliminary laboratory tests were carried out. The estimate of accuracy for planned laboratory studies was given.

Influenza surveillance: alternative laboratory techniques for a developing country*

PubMed Central

Canil, K. A.; Pratt, D.; Sungu, M. S.; Phillips, P. A.

1985-01-01

In developing countries it is often impractical to use conventional methods to isolate and identify influenza viruses. The use of trypsin-treated LLC-MK2 cells for the isolation of myxoviruses, in conjunction with the indirect fluorescent antibody technique for identification of isolates and for direct detection of viral antigens in specimens, was an effective combination of techniques which enabled our laboratory in Papua New Guinea to participate in an influenza surveillance programme. The application of these techniques in routine respiratory virus surveillance and in the investigation of an outbreak of influenza-like illness is described. PMID:3872737

A study of J-coupling spectroscopy using the Earth's field nuclear magnetic resonance inside a laboratory.

PubMed

Liao, Shu-Hsien; Chen, Ming-Jye; Yang, Hong-Chang; Lee, Shin-Yi; Chen, Hsin-Hsien; Horng, Herng-Er; Yang, Shieh-Yueh

2010-10-01

In this paper, an instrumentation of the Earth's field nuclear magnetic resonance (EFNMR) inside a laboratory is presented. A lock-in analysis (LIA) technique was proposed to enhance the signal-to-noise ratio (SNR). A SNR of 137.8 was achieved in a single measurement for 9 ml tap water, and the LIA technique significantly enhanced the SNR to 188 after a 10-average in a noisy laboratory environment. The proton-phosphorus coupling in trimethyl phosphate ((CH(3)O)(3)PO) with J-coupling J[H,F]=(10.99±0.013) Hz has been demonstrated. The LIA technique improves the SNR, and a 2.6-fold improvement in SNR over that of the frequency-adjusted averaging is achieved. To reduce the noise in EFNMR, it was suggested that the LIA technique and the first order gradient shim be used to achieve a subhertz linewidth.

Method to Estimate the Dissolved Air Content in Hydraulic Fluid

NASA Technical Reports Server (NTRS)

Hauser, Daniel M.

2011-01-01

In order to verify the air content in hydraulic fluid, an instrument was needed to measure the dissolved air content before the fluid was loaded into the system. The instrument also needed to measure the dissolved air content in situ and in real time during the de-aeration process. The current methods used to measure the dissolved air content require the fluid to be drawn from the hydraulic system, and additional offline laboratory processing time is involved. During laboratory processing, there is a potential for contamination to occur, especially when subsaturated fluid is to be analyzed. A new method measures the amount of dissolved air in hydraulic fluid through the use of a dissolved oxygen meter. The device measures the dissolved air content through an in situ, real-time process that requires no additional offline laboratory processing time. The method utilizes an instrument that measures the partial pressure of oxygen in the hydraulic fluid. By using a standardized calculation procedure that relates the oxygen partial pressure to the volume of dissolved air in solution, the dissolved air content is estimated. The technique employs luminescent quenching technology to determine the partial pressure of oxygen in the hydraulic fluid. An estimated Henry s law coefficient for oxygen and nitrogen in hydraulic fluid is calculated using a standard method to estimate the solubility of gases in lubricants. The amount of dissolved oxygen in the hydraulic fluid is estimated using the Henry s solubility coefficient and the measured partial pressure of oxygen in solution. The amount of dissolved nitrogen that is in solution is estimated by assuming that the ratio of dissolved nitrogen to dissolved oxygen is equal to the ratio of the gas solubility of nitrogen to oxygen at atmospheric pressure and temperature. The technique was performed at atmospheric pressure and room temperature. The technique could be theoretically carried out at higher pressures and elevated temperatures.

Undergraduate Skills Laboratories at Sonoma State University

NASA Astrophysics Data System (ADS)

Gill, Amandeep; Zack, K.; Mills, H.; Cunningham, B.; Jackowski, S.

2014-01-01

Due to the current economic climate, funding sources for many laboratory courses have been cut from university budgets. However, it is still necessary for undergraduates to master laboratory skills to be prepared and competitive applicants when entering the professional world and/or graduate school. In this context, student-led programs may be able to compensate for this lack of formal instruction and reinforce concepts from lecture by applying research techniques to develop hands-on comprehension. The Sonoma State University Chapter of Society of Physics Students has established a peer-led skills lab to teach research techniques in the fields of astronomy and physics. The goal is to alleviate the pressures of both independently learning and efficiently applying techniques to junior and senior-level research projects. These skill labs are especially valuable for nontraditional students who, due to work or family duties, may not get a chance to fully commit to research projects. For example, a topic such as Arduino programming has a multitude of applications in both astronomy and physics, but is not taught in traditional university courses. Although some programming and electronics skills are taught in (separate) classes, they are usually not applied to actual research projects, which combined expertise is needed. For example, in astronomy, there are many situations involving programming telescopes and taking data with electronic cameras. Often students will carry out research using these tools but when something goes wrong, the students will not have the skills to trouble shoot and fix the system. Another astronomical topic to be taught in the skills labs is the analysis of astronomical data, including running remote telescopes, analyzing photometric variability, and understanding the concepts of star magnitudes, flat fields, and biases. These workshops provide a setting in which the student teacher may strengthen his or her understanding of the topic by presenting it to peers. Students teaching fellow peers is an ideal method of furthering understanding for all participants, and the skills lab established by the SPS has begun this process at SSU.

Merging of Research and Teaching in Developmental Biology: Adaptation of Current Scientific Research Papers for Use in Undergraduate Laboratory Exercises

ERIC Educational Resources Information Center

Lee, H. H.; and others

1970-01-01

Describes two laboratory exercises adopted from current research papers for use in an undergraduate developmental biology course. Gives methods, summary of student results, and student comments. Lists lecture topics, text and reprint assignments, and laboratory exercises for course. (EB)

The predator and prey behaviors of crabs: from ecology to neural adaptations.

PubMed

Tomsic, Daniel; Sztarker, Julieta; Berón de Astrada, Martín; Oliva, Damián; Lanza, Estela

2017-07-01

Predator avoidance and prey capture are among the most vital of animal behaviors. They require fast reactions controlled by comparatively straightforward neural circuits often containing giant neurons, which facilitates their study with electrophysiological techniques. Naturally occurring avoidance behaviors, in particular, can be easily and reliably evoked in the laboratory, enabling their neurophysiological investigation. Studies in the laboratory alone, however, can lead to a biased interpretation of an animal's behavior in its natural environment. In this Review, we describe current knowledge - acquired through both laboratory and field studies - on the visually guided escape behavior of the crab Neohelice granulata Analyses of the behavioral responses to visual stimuli in the laboratory have revealed the main characteristics of the crab's performance, such as the continuous regulation of the speed and direction of the escape run, or the enduring changes in the strength of escape induced by learning and memory. This work, in combination with neuroanatomical and electrophysiological studies, has allowed the identification of various giant neurons, the activity of which reflects most essential aspects of the crabs' avoidance performance. In addition, behavioral analyses performed in the natural environment reveal a more complex picture: crabs make use of much more information than is usually available in laboratory studies. Moreover, field studies have led to the discovery of a robust visually guided chasing behavior in Neohelice Here, we describe similarities and differences in the results obtained between the field and the laboratory, discuss the sources of any differences and highlight the importance of combining the two approaches. © 2017. Published by The Company of Biologists Ltd.

Quality Assessment of Urinary Stone Analysis: Results of a Multicenter Study of Laboratories in Europe

PubMed Central

Siener, Roswitha; Buchholz, Noor; Daudon, Michel; Hess, Bernhard; Knoll, Thomas; Osther, Palle J.; Reis-Santos, José; Sarica, Kemal; Traxer, Olivier; Trinchieri, Alberto

2016-01-01

After stone removal, accurate analysis of urinary stone composition is the most crucial laboratory diagnostic procedure for the treatment and recurrence prevention in the stone-forming patient. The most common techniques for routine analysis of stones are infrared spectroscopy, X-ray diffraction and chemical analysis. The aim of the present study was to assess the quality of urinary stone analysis of laboratories in Europe. Nine laboratories from eight European countries participated in six quality control surveys for urinary calculi analyses of the Reference Institute for Bioanalytics, Bonn, Germany, between 2010 and 2014. Each participant received the same blinded test samples for stone analysis. A total of 24 samples, comprising pure substances and mixtures of two or three components, were analysed. The evaluation of the quality of the laboratory in the present study was based on the attainment of 75% of the maximum total points, i.e. 99 points. The methods of stone analysis used were infrared spectroscopy (n = 7), chemical analysis (n = 1) and X-ray diffraction (n = 1). In the present study only 56% of the laboratories, four using infrared spectroscopy and one using X-ray diffraction, fulfilled the quality requirements. According to the current standard, chemical analysis is considered to be insufficient for stone analysis, whereas infrared spectroscopy or X-ray diffraction is mandatory. However, the poor results of infrared spectroscopy highlight the importance of equipment, reference spectra and qualification of the staff for an accurate analysis of stone composition. Regular quality control is essential in carrying out routine stone analysis. PMID:27248840

Quality Assessment of Urinary Stone Analysis: Results of a Multicenter Study of Laboratories in Europe.

PubMed

Siener, Roswitha; Buchholz, Noor; Daudon, Michel; Hess, Bernhard; Knoll, Thomas; Osther, Palle J; Reis-Santos, José; Sarica, Kemal; Traxer, Olivier; Trinchieri, Alberto

2016-01-01

After stone removal, accurate analysis of urinary stone composition is the most crucial laboratory diagnostic procedure for the treatment and recurrence prevention in the stone-forming patient. The most common techniques for routine analysis of stones are infrared spectroscopy, X-ray diffraction and chemical analysis. The aim of the present study was to assess the quality of urinary stone analysis of laboratories in Europe. Nine laboratories from eight European countries participated in six quality control surveys for urinary calculi analyses of the Reference Institute for Bioanalytics, Bonn, Germany, between 2010 and 2014. Each participant received the same blinded test samples for stone analysis. A total of 24 samples, comprising pure substances and mixtures of two or three components, were analysed. The evaluation of the quality of the laboratory in the present study was based on the attainment of 75% of the maximum total points, i.e. 99 points. The methods of stone analysis used were infrared spectroscopy (n = 7), chemical analysis (n = 1) and X-ray diffraction (n = 1). In the present study only 56% of the laboratories, four using infrared spectroscopy and one using X-ray diffraction, fulfilled the quality requirements. According to the current standard, chemical analysis is considered to be insufficient for stone analysis, whereas infrared spectroscopy or X-ray diffraction is mandatory. However, the poor results of infrared spectroscopy highlight the importance of equipment, reference spectra and qualification of the staff for an accurate analysis of stone composition. Regular quality control is essential in carrying out routine stone analysis.

Cloning Yeast Actin cDNA Leads to an Investigative Approach for the Molecular Biology Laboratory

ERIC Educational Resources Information Center

Black, Michael W.; Tuan, Alice; Jonasson, Erin

2008-01-01

The emergence of molecular tools in multiple disciplines has elevated the importance of undergraduate laboratory courses that train students in molecular biology techniques. Although it would also be desirable to provide students with opportunities to apply these techniques in an investigative manner, this is generally not possible in the…

A Severe Weather Laboratory Exercise for an Introductory Weather and Climate Class Using Active Learning Techniques

ERIC Educational Resources Information Center

Grundstein, Andrew; Durkee, Joshua; Frye, John; Andersen, Theresa; Lieberman, Jordan

2011-01-01

This paper describes a new severe weather laboratory exercise for an Introductory Weather and Climate class, appropriate for first and second year college students (including nonscience majors), that incorporates inquiry-based learning techniques. In the lab, students play the role of meteorologists making forecasts for severe weather. The…

A simple technique for maintaining Simulium adults, including onchocerciasis vectors, under artificial conditions*

PubMed Central

Raybould, John N.; Mhiddin, Haji K.

1974-01-01

The maintenance of Simulium adults in the laboratory is necessary for many experimental investigations and is a prerequisite to laboratory colonization. A simple technique for this purpose is described in which each fly is kept separately in a hole bored in a block of expanded polystyrene. ImagesFig. 1 PMID:4549353

Spectrophotometric Determination of the Dissociation Constant of an Acid-Base Indicator Using a Mathematical Deconvolution Technique

ERIC Educational Resources Information Center

Alter, Krystyn P.; Molloy, John L.; Niemeyer, Emily D.

2005-01-01

A laboratory experiment reinforces the concept of acid-base equilibria while introducing a common application of spectrophotometry and can easily be completed within a standard four-hour laboratory period. It provides students with an opportunity to use advanced data analysis techniques like data smoothing and spectral deconvolution to…

Effectiveness of Student-Generated Video as a Teaching Tool for an Instrumental Technique in the Organic Chemistry Laboratory

ERIC Educational Resources Information Center

Jordan, Jeremy T.; Box, Melinda C.; Eguren, Kristen E.; Parker, Thomas A.; Saraldi-Gallardo, Victoria M.; Wolfe, Michael I.; Gallardo-Williams, Maria T.

2016-01-01

Multimedia instruction has been shown to serve as an effective learning aid for chemistry students. In this study, the viability of student-generated video instruction for organic chemistry laboratory techniques and procedure was examined and its effectiveness compared to instruction provided by a teaching assistant (TA) was evaluated. After…

Adjuncts in the IVF laboratory: where is the evidence for 'add-on' interventions?

PubMed

Harper, Joyce; Jackson, Emily; Sermon, Karen; Aitken, Robert John; Harbottle, Stephen; Mocanu, Edgar; Hardarson, Thorir; Mathur, Raj; Viville, Stephane; Vail, Andy; Lundin, Kersti

2017-03-01

Globally, IVF patients are routinely offered and charged for a selection of adjunct treatments and tests or 'add-ons' that they are told may improve their chance of a live birth, despite there being no clinical evidence supporting the efficacy of the add-on. Any new IVF technology claiming to improve live birth rates (LBR) should, in most cases, first be tested in an appropriate animal model, then in clinical trials, to ensure safety, and finally in a randomized controlled trial (RCT) to provide high-quality evidence that the procedure is safe and effective. Only then should the technique be considered as 'routine' and only when applied to the similar patient population as those studied in the RCT. Even then, further pediatric and long-term follow-up studies will need to be undertaken to examine the long-term safety of the procedure. Alarmingly, there are currently numerous examples where adjunct treatments are used in the absence of evidence-based medicine and often at an additional fee. In some cases, when RCTs have shown the technique to be ineffective, it is eventually withdrawn from the clinic. In this paper, we discuss some of the adjunct treatments currently being offered globally in IVF laboratories, including embryo glue and adherence compounds, sperm DNA fragmentation, time-lapse imaging, preimplantation genetic screening, mitochondria DNA load measurement and assisted hatching. We examine the evidence for their safety and efficacy in increasing LBRs. We conclude that robust studies are needed to confirm the safety and efficacy of any adjunct treatment or test before they are offered routinely to IVF patients. © The Author 2017. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Graphing techniques for materials laboratory using Excel

NASA Technical Reports Server (NTRS)

Kundu, Nikhil K.

1994-01-01

Engineering technology curricula stress hands on training and laboratory practices in most of the technical courses. Laboratory reports should include analytical as well as graphical evaluation of experimental data. Experience shows that many students neither have the mathematical background nor the expertise for graphing. This paper briefly describes the procedure and data obtained from a number of experiments such as spring rate, stress concentration, endurance limit, and column buckling for a variety of materials. Then with a brief introduction to Microsoft Excel the author explains the techniques used for linear regression and logarithmic graphing.

Laboratory Experiment of Magnetic Reconnection between Merging Flux Tubes with Strong Guide FIeld

NASA Astrophysics Data System (ADS)

Inomoto, M.; Kamio, S.; Kuwahata, A.; Ono, Y.

2013-12-01

Magnetic reconnection governs variety of energy release events in the universe, such as solar flares, geomagnetic substorms, and sawtooth crash in laboratory nuclear fusion experiments. Differently from the classical steady reconnection models, non-steady behavior of magnetic reconnection is often observed. In solar flares, intermittent enhancement of HXR emission is observed synchronously with multiple ejection of plammoids [1]. In laboratory reconnection experiments, the existence of the guide field, that is perpendicular to the reconnection field, makes significant changes on reconnection process. Generally the guide field will slow down the reconnection rate due to the increased magnetic pressure inside the current sheet. It also brings about asymmetric structure of the separatrices or effective particle acceleration in collisionless conditions. We have conducted laboratory experiments to study the behavior of the guide-field magnetic reconnection using plasma merging technique (push reconnection). Under substantial guide field even larger than the reconnection field, the reconnection generally exhibits non-steady feature which involves intermittent detachment of X-point and reconnection current center[2]. Transient enhancement of reconnection rate is observed simultaneously with the X-point motion[3]. We found two distinct phenomena associated with the guide-field non-steady reconnection. The one is the temporal and localized He II emission from X-point region, suggesting the production of energetic electrons which could excite the He ions in the vicinity of the X-point. The other is the excitation of large-amplitude electromagnetic waves which have similar properties with kinetic Alfven waves, whose amplitude show positive correlation with the enhancement of the reconnection electric field[4]. Electron beam instability caused by the energetic electrons accelerated to more than twice of the electron thermal velocity could be a potential driver of the monochromatic magnetic fluctuations. In conclusion, the laboratory guide field reconnection experiments showed some unique features such as ejection of current sheet, localized enhancement of emission, and excitation of low frequency waves, suggesting intermittent fast reconnection mechanism with significant electron acceleration. [1] N. Nishizuka et al., Astrophysical J. 711, 1062 (2010). [2] Y. Ono et al., Phys. Plasmas 18, 111213 (2011). [3] M. Inomoto et al., Plasma and Fusion Res. 8, 2401112 (2013). [4] M. Inomoto et al., Phys. Plasmas 20, 061209 (2013).

Bayesian Techniques for Plasma Theory to Bridge the Gap Between Space and Lab Plasmas

NASA Astrophysics Data System (ADS)

Crabtree, Chris; Ganguli, Gurudas; Tejero, Erik

2017-10-01

We will show how Bayesian techniques provide a general data analysis methodology that is better suited to investigate phenomena that require a nonlinear theory for an explanation. We will provide short examples of how Bayesian techniques have been successfully used in the radiation belts to provide precise nonlinear spectral estimates of whistler mode chorus and how these techniques have been verified in laboratory plasmas. We will demonstrate how Bayesian techniques allow for the direct competition of different physical theories with data acting as the necessary arbitrator. This work is supported by the Naval Research Laboratory base program and by the National Aeronautics and Space Administration under Grant No. NNH15AZ90I.

The current and future status of the concealed information test for field use.

PubMed

Matsuda, Izumi; Nittono, Hiroshi; Allen, John J B

2012-01-01

The Concealed Information Test (CIT) is a psychophysiological technique for examining whether a person has knowledge of crime-relevant information. Many laboratory studies have shown that the CIT has good scientific validity. However, the CIT has seldom been used for actual criminal investigations. One successful exception is its use by the Japanese police. In Japan, the CIT has been widely used for criminal investigations, although its probative force in court is not strong. In this paper, we first review the current use of the field CIT in Japan. Then, we discuss two possible approaches to increase its probative force: sophisticated statistical judgment methods and combining new psychophysiological measures with classic autonomic measures. On the basis of these considerations, we propose several suggestions for future practice and research involving the field CIT.

The Current and Future Status of the Concealed Information Test for Field Use

PubMed Central

Matsuda, Izumi; Nittono, Hiroshi; Allen, John J. B.

2012-01-01

The Concealed Information Test (CIT) is a psychophysiological technique for examining whether a person has knowledge of crime-relevant information. Many laboratory studies have shown that the CIT has good scientific validity. However, the CIT has seldom been used for actual criminal investigations. One successful exception is its use by the Japanese police. In Japan, the CIT has been widely used for criminal investigations, although its probative force in court is not strong. In this paper, we first review the current use of the field CIT in Japan. Then, we discuss two possible approaches to increase its probative force: sophisticated statistical judgment methods and combining new psychophysiological measures with classic autonomic measures. On the basis of these considerations, we propose several suggestions for future practice and research involving the field CIT. PMID:23205018

Perovskite Solar Cells: From the Laboratory to the Assembly Line.

PubMed

Abate, Antonio; Correa-Baena, Juan-Pablo; Saliba, Michael; Su'ait, Mohd Sukor; Bella, Federico

2018-03-02

Despite the fact that perovskite solar cells (PSCs) have a strong potential as a next-generation photovoltaic technology due to continuous efficiency improvements and the tunable properties, some important obstacles remain before industrialization is feasible. For example, the selection of low-cost or easy-to-prepare materials is essential for back-contacts and hole-transporting layers. Likewise, the choice of conductive substrates, the identification of large-scale manufacturing techniques as well as the development of appropriate aging protocols are key objectives currently under investigation by the international scientific community. This Review analyses the above aspects and highlights the critical points that currently limit the industrial production of PSCs and what strategies are emerging to make these solar cells the leaders in the photovoltaic field. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

[Current macro-diagnostic trends of forensic medicine in the Czech Republic].

PubMed

Frišhons, Jan; Kučerová, Štěpánka; Jurda, Mikoláš; Sokol, Miloš; Vojtíšek, Tomáš; Hejna, Petr

2017-01-01

Over the last few years, advanced diagnostic methods have penetrated in the realm of forensic medicine in addition to standard autopsy techniques supported by traditional X-ray examination and macro-diagnostic laboratory tests. Despite the progress of imaging methods, the conventional autopsy has remained basic and essential diagnostic tool in forensic medicine. Postmortem computed tomography and magnetic resonance imaging are far the most progressive modern radio diagnostic methods setting the current trend of virtual autopsies all over the world. Up to now, only two institutes of forensic medicine have available postmortem computed tomography for routine diagnostic purposes in the Czech Republic. Postmortem magnetic resonance is currently unattainable for routine diagnostic use and was employed only for experimental purposes. Photogrammetry is digital method focused primarily on body surface imaging. Recently, the most fruitful results have been yielded from the interdisciplinary cooperation between forensic medicine and forensic anthropology with the implementation of body scanning techniques and 3D printing. Non-invasive and mini-invasive investigative methods such as postmortem sonography and postmortem endoscopy was unsystematically tested for diagnostic performance with good outcomes despite of limitations of these methods in postmortem application. Other futuristic methods, such as the use of a drone to inspect the crime scene are still experimental tools. The authors of the article present a basic overview of the both routinely and experimentally used investigative methods and current macro-diagnostic trends of the forensic medicine in the Czech Republic.

Rapid and Adaptable Measurement of Protein Thermal Stability by Differential Scanning Fluorimetry: Updating a Common Biochemical Laboratory Experiment

ERIC Educational Resources Information Center

Johnson, R. Jeremy; Savas, Christopher J.; Kartje, Zachary; Hoops, Geoffrey C.

2014-01-01

Measurement of protein denaturation and protein folding is a common laboratory technique used in undergraduate biochemistry laboratories. Differential scanning fluorimetry (DSF) provides a rapid, sensitive, and general method for measuring protein thermal stability in an undergraduate biochemistry laboratory. In this method, the thermal…

International Technical Working Group Round Robin Tests

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

Dudder, Gordon B.; Hanlen, Richard C.; Herbillion, Georges M.

The goal of nuclear forensics is to develop a preferred approach to support illicit trafficking investigations. This approach must be widely understood and accepted as credible. The principal objectives of the Round Robin Tests are to prioritize forensic techniques and methods, evaluate attribution capabilities, and examine the utility of database. The HEU (Highly Enriched Uranium) Round Robin, and previous Plutonium Round Robin, have made tremendous contributions to fulfilling these goals through a collaborative learning experience that resulted from the outstanding efforts of the nine participating internal laboratories. A prioritized list of techniques and methods has been developed based on thismore » exercise. Current work is focused on the extent to which the techniques and methods can be generalized. The HEU Round Robin demonstrated a rather high level of capability to determine the important characteristics of the materials and processes using analytical methods. When this capability is combined with the appropriate knowledge/database, it results in a significant capability to attribute the source of the materials to a specific process or facility. A number of shortfalls were also identified in the current capabilities including procedures for non-nuclear forensics and the lack of a comprehensive network of data/knowledge bases. The results of the Round Robin will be used to develop guidelines or a ''recommended protocol'' to be made available to the interested authorities and countries to use in real cases.« less

Standoff concealed weapon detection using a 350-GHz radar imaging system

NASA Astrophysics Data System (ADS)

Sheen, David M.; Hall, Thomas E.; Severtsen, Ronald H.; McMakin, Douglas L.; Hatchell, Brian K.; Valdez, Patrick L. J.

2010-04-01

The sub-millimeter (sub-mm) wave frequency band from 300 - 1000 GHz is currently being developed for standoff concealed weapon detection imaging applications. This frequency band is of interest due to the unique combination of high resolution and clothing penetration. The Pacific Northwest National Laboratory (PNNL) is currently developing a 350 GHz, active, wideband, three-dimensional, radar imaging system to evaluate the feasibility of active sub-mm imaging for standoff detection. Standoff concealed weapon and explosive detection is a pressing national and international need for both civilian and military security, as it may allow screening at safer distances than portal screening techniques. PNNL has developed a prototype active wideband 350 GHz radar imaging system based on a wideband, heterodyne, frequency-multiplier-based transceiver system coupled to a quasi-optical focusing system and high-speed rotating conical scanner. This prototype system operates at ranges up to 10+ meters, and can acquire an image in 10 - 20 seconds, which is fast enough to scan cooperative personnel for concealed weapons. The wideband operation of this system provides accurate ranging information, and the images obtained are fully three-dimensional. During the past year, several improvements to the system have been designed and implemented, including increased imaging speed using improved balancing techniques, wider bandwidth, and improved image processing techniques. In this paper, the imaging system is described in detail and numerous imaging results are presented.

Dynamo-driven plasmoid formation from a current-sheet instability

DOE PAGES

Ebrahimi, F.

2016-12-15

Axisymmetric current-carrying plasmoids are formed in the presence of nonaxisymmetric fluctuations during nonlinear three-dimensional resistive MHD simulations in a global toroidal geometry. In this study, we utilize the helicity injection technique to form an initial poloidal flux in the presence of a toroidal guide field. As helicity is injected, two types of current sheets are formed from the oppositely directed field lines in the injector region (primary reconnecting current sheet), and the poloidal flux compression near the plasma edge (edge current sheet). We first find that nonaxisymmetric fluctuations arising from the current-sheet instability isolated near the plasma edge have tearingmore » parity but can nevertheless grow fast (on the poloidal Alfven time scale). These modes saturate by breaking up the current sheet. Second, for the first time, a dynamo poloidal flux amplification is observed at the reconnection site (in the region of the oppositely directed magnetic field). This fluctuation-induced flux amplification increases the local Lundquist number, which then triggers a plasmoid instability and breaks the primary current sheet at the reconnection site. Finally, the plasmoids formation driven by large-scale flux amplification, i.e., a large-scale dynamo, observed here has strong implications for astrophysical reconnection as well as fast reconnection events in laboratory plasmas.« less

Assessment of readiness for clinical decision support to aid laboratory monitoring of immunosuppressive care at U.S. liver transplant centers.

PubMed

Jacobs, J; Weir, C; Evans, R S; Staes, C

2014-01-01

Following liver transplantation, patients require lifelong immunosuppressive care and monitoring. Computerized clinical decision support (CDS) has been shown to improve post-transplant immunosuppressive care processes and outcomes. The readiness of transplant information systems to implement computerized CDS to support post-transplant care is unknown. a) Describe the current clinical information system functionality and manual and automated processes for laboratory monitoring of immunosuppressive care, b) describe the use of guidelines that may be used to produce computable logic and the use of computerized alerts to support guideline adherence, and c) explore barriers to implementation of CDS in U.S. liver transplant centers. We developed a web-based survey using cognitive interviewing techniques. We surveyed 119 U.S. transplant programs that performed at least five liver transplantations per year during 2010-2012. Responses were summarized using descriptive analyses; barriers were identified using qualitative methods. Respondents from 80 programs (67% response rate) completed the survey. While 98% of programs reported having an electronic health record (EHR), all programs used paper-based manual processes to receive or track immunosuppressive laboratory results. Most programs (85%) reported that 30% or more of their patients used external laboratories for routine testing. Few programs (19%) received most external laboratory results as discrete data via electronic interfaces while most (80%) manually entered laboratory results into the EHR; less than half (42%) could integrate internal and external laboratory results. Nearly all programs had guidelines regarding pre-specified target ranges (92%) or testing schedules (97%) for managing immunosuppressive care. Few programs used computerized alerting to notify transplant coordinators of out-of-range (27%) or overdue laboratory results (20%). Use of EHRs is common, yet all liver transplant programs were largely dependent on manual paper-based processes to monitor immunosuppression for post-liver transplant patients. Similar immunosuppression guidelines provide opportunities for sharing CDS once integrated laboratory data are available.

Phospholipid Fatty Acid Analysis: Past, Present and Future

NASA Astrophysics Data System (ADS)

Findlay, R. H.

2008-12-01

With their 1980 publication, Bobbie and White initiated the use of phospholipid fatty acids for the study of microbial communities. This method, integrated with a previously published biomass assay based on the colorimetric detection of orthophosphate liberated from phospholipids, provided the first quantitative method for determining microbial community structure. The method is based on a quantitative extraction of lipids from the sample matrix, isolation of the phospholipids, conversion of the phospholipid fatty acids to their corresponding fatty acid methyl esters (known by the acronym FAME) and the separation, identification and quantification of the FAME by gas chromatography. Early laboratory and field samples focused on correlating individual fatty acids to particular groups of microorganisms. Subsequent improvements to the methodology include reduced solvent volumes for extractions, improved sensitivity in the detection of orthophosphate and the use of solid phase extraction technology. Improvements in the field of gas chromatography also increased accessibility of the technique and it has been widely applied to water, sediment, soil and aerosol samples. Whole cell fatty acid analysis, a related but not equal technique, is currently used for phenotypic characterization in bacterial species descriptions and is the basis for a commercial, rapid bacterial identification system. In the early 1990ês application of multivariate statistical analysis, first cluster analysis and then principal component analysis, further improved the usefulness of the technique and allowed the development of a functional group approach to interpretation of phospholipid fatty acid profiles. Statistical techniques currently applied to the analysis of phospholipid fatty acid profiles include constrained ordinations and neutral networks. Using redundancy analysis, a form of constrained ordination, we have recently shown that both cation concentration and dissolved organic matter (DOM) quality are determinates of microbial community structure in forested headwater streams. One of the most exciting recent developments in phospholipid fatty acid analysis is the application of compound specific stable isotope analysis. We are currently applying this technique to stream sediments to help determine which microorganisms are involved in the initial processing of DOM and the technique promises to be a useful tool for assigning ecological function to microbial populations.

The Current State of Sustainability in Bioscience Laboratories: A Statistical Examination of a UK Tertiary Institute

ERIC Educational Resources Information Center

Wright, Hazel A.; Ironside, Joseph E.; Gwynn-Jones, Dylan

2008-01-01

Purpose: This study aims to identify the current barriers to sustainability in the bioscience laboratory setting and to determine which mechanisms are likely to increase sustainable behaviours in this specialised environment. Design/methodology/approach: The study gathers qualitative data from a sample of laboratory researchers presently…

75 FR 75485 - Current List of Laboratories Which Meet Minimum Standards To Engage in Urine Drug Testing for...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-12-03

... Current List of Laboratories Which Meet Minimum Standards To Engage in Urine Drug Testing for Federal... Guidelines for Federal Workplace Drug Testing Programs (Mandatory Guidelines). The Mandatory Guidelines were... Laboratories and Instrumented Initial Testing Facilities (IITF) must meet in order to conduct drug and specimen...

75 FR 39023 - Current List of Laboratories Which Meet Minimum Standards To Engage in Urine Drug Testing for...

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2010-07-07

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2010-05-14

... Current List of Laboratories Which Meet Minimum Standards To Engage in Urine Drug Testing for Federal... Drug Testing Programs (Mandatory Guidelines). The Mandatory Guidelines were first published in the... of Laboratories Engaged in Urine Drug Testing for Federal Agencies,'' sets strict standards that...

75 FR 9229 - Current List of Laboratories Which Meet Minimum Standards To Engage in Urine Drug Testing for...

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2010-03-01

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75 FR 5088 - Current List of Laboratories Which Meet Minimum Standards To Engage in Urine Drug Testing for...

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2010-02-01

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2010-01-04

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75 FR 45128 - Current List of Laboratories Which Meet Minimum Standards To Engage in Urine Drug Testing for...

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2010-08-02

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75 FR 32950 - Current List of Laboratories Which Meet Minimum Standards To Engage in Urine Drug Testing for...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-10

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75 FR 55795 - Current List of Laboratories Which Meet Minimum Standards To Engage in Urine Drug Testing for...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-09-14

... Current List of Laboratories Which Meet Minimum Standards To Engage in Urine Drug Testing for Federal... Drug Testing Programs (Mandatory Guidelines). The Mandatory Guidelines were first published in the... of Laboratories Engaged in Urine Drug Testing for Federal Agencies,'' sets strict standards that...

WHO Melting-Point Reference Substances

PubMed Central

Bervenmark, H.; Diding, N. Å.; Öhrner, B.

1963-01-01

Batches of 13 highly purified chemicals, intended for use as reference substances in the calibration of apparatus for melting-point determinations, have been subjected to a collaborative assay by 15 laboratories in 13 countries. All the laboratories performed melting-point determinations by the capillary methods described in the proposed text for the second edition of the Pharmacopoea Internationalis and some, in addition, carried out determinations by the microscope hot stage (Kofler) method, using both the “going-through” and the “equilibrium” technique. Statistical analysis of the data obtained by the capillary method showed that the within-laboratory variation was small and that the between-laboratory variation, though constituting the greatest part of the whole variance, was not such as to warrant the exclusion of any laboratory from the evaluation of the results. The average values of the melting-points obtained by the laboratories can therefore be used as constants for the substances in question, which have accordingly been established as WHO Melting-Point Reference Substances and included in the WHO collection of authentic chemical substances. As to the microscope hot stage method, analysis of the results indicated that the values obtained by the “going-through” technique did not differ significantly from those obtained by the capillary method, but the values obtained by the “equilibrium” technique were mostly significantly lower. PMID:20604137

Cobalt-chromium alloys in fixed prosthodontics in Sweden

PubMed Central

Kassapidou, Maria; Franke Stenport, Victoria; Hjalmarsson, Lars; Johansson, Carina B.

2017-01-01

Abstract Aim: The aim of this study was to compile the usage of Co-Cr alloys in fixed prosthodontics (FP) among dental laboratories in Sweden. Methods: From March to October 2015, questionnaires were sent to 542 registered dental laboratories in Sweden. The questionnaires were divided in two parts, one for fixed dental-supported prosthodontics (FDP) and one for fixed implant-supported prosthodontics (FIP). Reminders were sent three times. Results: In total of 542 dental laboratories, 55% answered the questionnaires. Most dental laboratories use Co-Cr in FP, 134 (74%) in FDP and 89(66%) in FIP. The laboratories used Co-Cr alloys of various compositions in the prostheses, 35 for FDP and 30 for FIP. The most commonly used Co-Cr alloys for tooth-supported FDPs were (a) Wirobond® 280, (b) Cara SLM and (c) Wirobond® C. For implant-supported frameworks the frequently used alloys were: (a) Cara SLM, (b) Cara Milled and (c) Wirobond® 280. Except for the difference in composition of these alloys, they were also manufactured with various techniques. In tooth-supported prostheses the dominating technique was the cast technique while newer techniques as laser-sintering and milling were more commonly reported for implant-supported constructions. A fourth technique; the ‘pre-state’ milling was reported in FDP. Conclusion: More than 30 different Co-Cr alloys were reported as being used in FP. Thus, there is a need for studies exploring the mechanical and physical behavior and the biological response to the most commonly used Co-Cr alloys. PMID:29242813

Paving the way for a gold standard of care for infertility treatment: improving outcomes through standardization of laboratory procedures.

PubMed

Schoolcraft, William; Meseguer, Marcos

2017-10-01

Infertility affects over 70 million couples globally. Access to, and interest in, assisted reproductive technologies is growing worldwide, with more couples seeking medical intervention to conceive, in particular by IVF. Despite numerous advances in IVF techniques since its first success in 1978, almost half of the patients treated remain childless. The multifactorial nature of IVF treatment means that success is dependent on many variables. Therefore, it is important to examine how each variable can be optimized to achieve the best possible outcomes for patients. The current approach to IVF is fragmented, with various protocols in use. A systematic approach to establishing optimum best practices may improve IVF success and live birth rates. Our vision of the future is that technological advancements in the laboratory setting are standardized and universally adopted to enable a gold standard of care. Implementation of best practices for laboratory procedures will enable clinicians to generate high-quality gametes, and to produce and identify gametes and embryos of maximum viability and implantation potential, which should contribute to improving take-home healthy baby rates. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

The metrology of time.

PubMed

Arias, Elisa Felicitas

2005-09-15

Measuring time is a continuous activity, an international and restless enterprise hidden in time laboratories spread all over the planet. The Bureau International des Poids et Mesures is charged with coordinating activities for international timekeeping and it makes use of the world's capacity to produce a remarkably stable and accurate reference time-scale. Commercial atomic clocks beating the second in national laboratories can reach a stability of one part in 10(14) over a 5 day averaging time, compelling us to research the most highly performing methods of remote clock comparison. The unit of the international time-scale is the second of the International System of Units, realized with an uncertainty of the order 10(-15) by caesium fountains. Physicists in a few time laboratories are making efforts to gain one order of magnitude in the uncertainty of the realization of the second, and more refined techniques of time and frequency transfer are in development to accompany this progress. Femtosecond comb technology will most probably contribute in the near future to enhance the definition of the second with the incorporation of optical clocks. We will explain the evolution of the measuring of time, current state-of-the-art measures and future challenges.

Current status of accreditation for drug testing in hair.

PubMed

Cooper, Gail; Moeller, Manfred; Kronstrand, Robert

2008-03-21

At the annual meeting of the Society of Hair Testing in Vadstena, Sweden in 2006, a committee was appointed to address the issue of guidelines for hair testing and to assess the current status of accreditation amongst laboratories offering drug testing in hair. A short questionnaire was circulated amongst the membership and interested parties. Fifty-two responses were received from hair testing laboratories providing details on the amount and type of hair tests they offered and the status of accreditation within their facilities. Although the vast majority of laboratories follow current guidelines (83%), only nine laboratories were accredited to ISO/IEC 17025 for hair testing. A significant number of laboratories reporting that they were in the process of developing quality systems with a view to accrediting their methods within 2-3 years. This study provides an insight into the status of accreditation in hair testing laboratories and supports the need for guidelines to encourage best practice.

Nutritional supplementation and artificial reproductive technique (ART) outcomes.

PubMed

Kermack, A J; Macklon, N S

2015-05-01

Approximately one in six couples suffer from subfertility, and many seek treatment with artificial reproductive technologies (ART). Despite improvements in laboratory techniques and ovarian stimulation, ongoing pregnancy rates per cycle remain at ~25%. Couples wanting to improve their chances may turn to adjuvant therapies, such as nutritional supplements. There is growing evidence that periconceptional nutritional status is a key determinant of fertility and long-term health of the offspring, and a lucrative market has developed to meet the demand based on these benefits. However, the practice of routine dietary supplementation before and during IVF treatment has not been subject to well-powered prospective randomised trials. In this article, the potential roles of specific nutritional supplements in the context of improving IVF outcomes are reviewed and an assessment is made of the evidence base supporting their clinical use in this context. Finally, current research needs in the field are outlined.

Towards neutron scattering experiments with sub-millisecond time resolution

DOE PAGES

Adlmann, F. A.; Gutfreund, Phillip; Ankner, John Francis; ...

2015-02-01

Neutron scattering techniques offer several unique opportunities in materials research. However, most neutron scattering experiments suffer from the limited flux available at current facilities. This limitation becomes even more severe if time-resolved or kinetic experiments are performed. A new method has been developed which overcomes these limitations when a reversible process is studied, without any compromise on resolution or beam intensity. We demonstrate that, by recording in absolute time the neutron detector events linked to an excitation, information can be resolved on sub-millisecond timescales. Specifically, the concept of the method is demonstrated by neutron reflectivity measurements in time-of-flight mode atmore » the Liquids Reflectometer located at the Spallation Neutron Source, Oak Ridge National Laboratory, Tennessee, USA, combined with in situ rheometry. Finally, the opportunities and limitations of this new technique are evaluated by investigations of a micellar polymer solution offering excellent scattering contrast combined with high sensitivity to shear.« less

Microfluidics for Single-Cell Genetic Analysis

PubMed Central

Thompson, A. M.; Paguirigan, A. L.; Kreutz, J. E.; Radich, J. P.; Chiu, D. T.

2014-01-01

The ability to correlate single-cell genetic information to cellular phenotypes will provide the kind of detailed insight into human physiology and disease pathways that is not possible to infer from bulk cell analysis. Microfluidic technologies are attractive for single-cell manipulation due to precise handling and low risk of contamination. Additionally, microfluidic single-cell techniques can allow for high-throughput and detailed genetic analyses that increase accuracy and decreases reagent cost compared to bulk techniques. Incorporating these microfluidic platforms into research and clinical laboratory workflows can fill an unmet need in biology, delivering the highly accurate, highly informative data necessary to develop new therapies and monitor patient outcomes. In this perspective, we describe the current and potential future uses of microfluidics at all stages of single-cell genetic analysis, including cell enrichment and capture, single-cell compartmentalization and manipulation, and detection and analyses. PMID:24789374

Radiation Modeling with Direct Simulation Monte Carlo

NASA Technical Reports Server (NTRS)

Carlson, Ann B.; Hassan, H. A.

1991-01-01

Improvements in the modeling of radiation in low density shock waves with direct simulation Monte Carlo (DSMC) are the subject of this study. A new scheme to determine the relaxation collision numbers for excitation of electronic states is proposed. This scheme attempts to move the DSMC programs toward a more detailed modeling of the physics and more reliance on available rate data. The new method is compared with the current modeling technique and both techniques are compared with available experimental data. The differences in the results are evaluated. The test case is based on experimental measurements from the AVCO-Everett Research Laboratory electric arc-driven shock tube of a normal shock wave in air at 10 km/s and .1 Torr. The new method agrees with the available data as well as the results from the earlier scheme and is more easily extrapolated to di erent ow conditions.

Physics Laboratory Investigation of Vocational High School Field Stone and Concrete Construction Techniques in the Central Java Province (Indonesia)

ERIC Educational Resources Information Center

Purwandari, Ristiana Dyah

2015-01-01

The investigation aims in this study were to uncover the observations of infrastructures and physics laboratory in vocational high school for Stone and Concrete Construction Techniques Expertise Field or Teknik Konstruksi Batu dan Beton (TKBB)'s in Purwokerto Central Java Province, mapping the Vocational High School or Sekolah Menengah Kejuruan…

Using an Advanced Computational Laboratory Experiment to Extend and Deepen Physical Chemistry Students' Understanding of Atomic Structure

ERIC Educational Resources Information Center

Hoffman, Gary G.

2015-01-01

A computational laboratory experiment is described, which involves the advanced study of an atomic system. The students use concepts and techniques typically covered in a physical chemistry course but extend those concepts and techniques to more complex situations. The students get a chance to explore the study of atomic states and perform…

Application of the One-Minute Preceptor Technique by Novice Teachers in the Gross Anatomy Laboratory

ERIC Educational Resources Information Center

Chan, Lap Ki; Yang, Jian; Irby, David M.

2015-01-01

The one-minute preceptor (OMP) was originally developed in the ambulatory care setting as a time-efficient teaching technique for learner-centered clinical training. There are also possible advantages of using the OMP in the gross anatomy laboratory. However, in a previous study it was found that providing training to experienced gross anatomy…

X-Ray Crystallography Analysis of Complexes Synthesized with Tris(2-pyridylmethyl)amine: A Laboratory Experiment for Undergraduate Students Integrating Interdisciplinary Concepts and Techniques

ERIC Educational Resources Information Center

Bazley, Isabel J.; Erie, Ellen A.; Feiereisel, Garrett M.; LeWarne, Christopher J.; Peterson, Jack M.; Sandquist, Katherine L.; Oshin, Kayode D.; Zeller, Matthias

2018-01-01

An integrated laboratory experiment applying concepts and techniques from organic chemistry, inorganic chemistry, and instrumental analysis is presented for use in the undergraduate curriculum. This experiment highlights the synthesis, characterization, and use of tris(2-pyridylmethyl)amine (TPMA) to make complexes with different metal salts. It…

Solution-Phase Synthesis of Dipeptides: A Capstone Project That Employs Key Techniques in an Organic Laboratory Course

ERIC Educational Resources Information Center

Marchetti, Louis; DeBoef, Brenton

2015-01-01

A contemporary approach to the synthesis and purification of several UV-active dipeptides has been developed for the second-year organic laboratory. This experiment exposes students to the important technique of solution-phase peptide synthesis and allows an instructor to highlight the parallel between what they are accomplishing in the laboratory…

Review Of E-Beam Electrical Test Techniques

NASA Astrophysics Data System (ADS)

Hohn, Fritz J.

1987-09-01

Electron beams as a viable technique for contactless testing of electrical functions and electrical integrity of different active devices in VLSI-chips has been demonstrated over the past years. This method of testing electronic networks, most widely used in the laboratory environment, is based on an electron probe which is deflected from point to point in the network. A current of secondary electrons emitted in response to the impingement of the electron probe is converted to a signal indicating the presence of a voltage or varying potential at the different points. Voltage contrast, electron beam induced current, dual potential approach, stroboscopic techniques and other methods have been developed and are used to detect different functional failures in devices. Besides the VLSI application, the contactless testing of three dimensional conductor networks of a 10cm x 10cm x .8cm multilayer ceramic module poses a different and new application for the electron beam test technique. A dual potential electron beam test system allows to generate electron beam induced voltage contrast. The same system at a different potential is used to detect this voltage contrast over the large area without moving the substrate and thus test for the electrical integrity of the networks. Less attention in most of the applications has been paid to the electron optical environment, mostly SEM's were upgraded or converted to do the job of a "voltage contrast" machine. This by no means will satisfy all requirements and more thoughts have to be given to aspects such as: low voltage electron guns: thermal emitter, Schottky emitter, field emitter, low voltage electron optics, two lens systems, different means of detection, signal processing - storage and others. This paper will review available E-beam test techniques, specific applications and some critical components.

Advances in the in-field detection of microorganisms in ice.

PubMed

Barnett, Megan J; Pearce, David A; Cullen, David C

2012-01-01

The historic view of ice-bound ecosystems has been one of a predominantly lifeless environment, where microorganisms certainly exist but are assumed to be either completely inactive or in a state of long-term dormancy. However, this standpoint has been progressively overturned in the past 20years as studies have started to reveal the importance of microbial life in the functioning of these environments. Our present knowledge of the distribution, taxonomy, and metabolic activity of such microbial life has been derived primarily from laboratory-based analyses of collected field samples. To date, only a restricted range of life detection and characterization techniques have been applied in the field. Specific examples include direct observation and DNA-based techniques (microscopy, specific stains, and community profiling based on PCR amplification), the detection of biomarkers (such as adenosine triphosphate), and measurements of metabolism [through the uptake and incorporation of radiolabeled isotopes or chemical alteration of fluorescent substrates (umbelliferones are also useful here)]. On-going improvements in technology mean that smaller and more robust life detection and characterization systems are continually being designed, manufactured, and adapted for in-field use. Adapting technology designed for other applications is the main source of new methodology, and the range of techniques is currently increasing rapidly. Here we review the current use of technology and techniques to detect and characterize microbial life within icy environments and specifically its deployment to in-field situations. We discuss the necessary considerations, limitations, and adaptations, review emerging technologies, and highlight the future potential. Successful application of these new techniques to in-field studies will certainly generate new insights into the way ice bound ecosystems function. Copyright © 2012 Elsevier Inc. All rights reserved.

Construction and Potential Applications of Biosensors for Proteins in Clinical Laboratory Diagnosis

PubMed Central

Liu, Xuan

2017-01-01

Biosensors for proteins have shown attractive advantages compared to traditional techniques in clinical laboratory diagnosis. In virtue of modern fabrication modes and detection techniques, various immunosensing platforms have been reported on basis of the specific recognition between antigen-antibody pairs. In addition to profit from the development of nanotechnology and molecular biology, diverse fabrication and signal amplification strategies have been designed for detection of protein antigens, which has led to great achievements in fast quantitative and simultaneous testing with extremely high sensitivity and specificity. Besides antigens, determination of antibodies also possesses great significance for clinical laboratory diagnosis. In this review, we will categorize recent immunosensors for proteins by different detection techniques. The basic conception of detection techniques, sensing mechanisms, and the relevant signal amplification strategies are introduced. Since antibodies and antigens have an equal position to each other in immunosensing, all biosensing strategies for antigens can be extended to antibodies under appropriate optimizations. Biosensors for antibodies are summarized, focusing on potential applications in clinical laboratory diagnosis, such as a series of biomarkers for infectious diseases and autoimmune diseases, and an evaluation of vaccine immunity. The excellent performances of these biosensors provide a prospective space for future antibody-detection-based disease serodiagnosis. PMID:29207528

Construction and Potential Applications of Biosensors for Proteins in Clinical Laboratory Diagnosis.

PubMed

Liu, Xuan; Jiang, Hui

2017-12-04

Biosensors for proteins have shown attractive advantages compared to traditional techniques in clinical laboratory diagnosis. In virtue of modern fabrication modes and detection techniques, various immunosensing platforms have been reported on basis of the specific recognition between antigen-antibody pairs. In addition to profit from the development of nanotechnology and molecular biology, diverse fabrication and signal amplification strategies have been designed for detection of protein antigens, which has led to great achievements in fast quantitative and simultaneous testing with extremely high sensitivity and specificity. Besides antigens, determination of antibodies also possesses great significance for clinical laboratory diagnosis. In this review, we will categorize recent immunosensors for proteins by different detection techniques. The basic conception of detection techniques, sensing mechanisms, and the relevant signal amplification strategies are introduced. Since antibodies and antigens have an equal position to each other in immunosensing, all biosensing strategies for antigens can be extended to antibodies under appropriate optimizations. Biosensors for antibodies are summarized, focusing on potential applications in clinical laboratory diagnosis, such as a series of biomarkers for infectious diseases and autoimmune diseases, and an evaluation of vaccine immunity. The excellent performances of these biosensors provide a prospective space for future antibody-detection-based disease serodiagnosis.

[Standardization of Blastocystis hominis diagnosis using different staining techniques].

PubMed

Eymael, Dayane; Schuh, Graziela Maria; Tavares, Rejane Giacomelli

2010-01-01

The present study was carried out from March to May 2008, with the aim of evaluating the effectiveness of different techniques for diagnosing Blastocystis hominis in a sample of the population attended at the Biomedicine Laboratory of Feevale University, Novo Hamburgo, Rio Grande do Sul. On hundred feces samples from children and adults were evaluated. After collection, the samples were subjected to the techniques of spontaneous sedimentation (HPJ), sedimentation in formalin-ether (Ritchie) and staining by means of Gram and May-Grünwald-Giemsa (MGG). The presence of Blastocystis hominis was observed in 40 samples, when staining techniques were used (MGG and Gram), while sedimentation techniques were less efficient (32 positive samples using the Ritchie technique and 20 positive samples using the HPJ technique). Our results demonstrate that HPJ was less efficient than the other methods, thus indicating the need to include laboratory techniques that enable parasite identification on a routine basis.

Proficiency Testing for Determination of Water Content in Toluene of Chemical Reagents by iteration robust statistic technique

NASA Astrophysics Data System (ADS)

Wang, Hao; Wang, Qunwei; He, Ming

2018-05-01

In order to investigate and improve the level of detection technology of water content in liquid chemical reagents of domestic laboratories, proficiency testing provider PT0031 (CNAS) has organized proficiency testing program of water content in toluene, 48 laboratories from 18 provinces/cities/municipals took part in the PT. This paper introduces the implementation process of proficiency testing for determination of water content in toluene, including sample preparation, homogeneity and stability test, the results of statistics of iteration robust statistic technique and analysis, summarized and analyzed those of the different test standards which are widely used in the laboratories, put forward the technological suggestions for the improvement of the test quality of water content. Satisfactory results were obtained by 43 laboratories, amounting to 89.6% of the total participating laboratories.

Laboratory measurements of microwave and millimeter-wave properties of planetary atmospheric constituents

NASA Technical Reports Server (NTRS)

Steffes, Paul G.

1989-01-01

Accurate data on microwave and millimeter-wave properties of potential planetary atmospheric constituents is critical for the proper interpretation of radio occultation measurements, and of radio astronomical observations of both continuum and spectral line emissions. Such data is also needed to correct for atmospheric effects on radar studies of surface reflectivity. Since the refractive and absorptive properties of atmospheric constituents often vary drastically from theoretically-predicted profiles, especially under the extreme conditions characteristic of the planetary atmosphere, laboratory measurements under simulated planetary conditions are required. This paper reviews the instrumentation and techniques used for laboratory measurement of the refractivity and absorptivity of atmospheric constituents at wavelengths longward of 1 mm, under simulated planetary conditions (temperature, pressure, and broadening gases). Techniques for measuring both gases and condensates are considered. Also reviewed are the relative accuracies of the various techniques. Laboratory measurements are reviewed which have already been made, and additional measurements which are needed for interpretation of data from Venus and the outer planets, are highlighted.

A FMEA clinical laboratory case study: how to make problems and improvements measurable.

PubMed

Capunzo, Mario; Cavallo, Pierpaolo; Boccia, Giovanni; Brunetti, Luigi; Pizzuti, Sante

2004-01-01

The authors have experimented the application of the Failure Mode and Effect Analysis (FMEA) technique in a clinical laboratory. FMEA technique allows: a) to evaluate and measure the hazards of a process malfunction, b) to decide where to execute improvement actions, and c) to measure the outcome of those actions. A small sample of analytes has been studied: there have been determined the causes of the possible malfunctions of the analytical process, calculating the risk probability index (RPI), with a value between 1 and 1,000. Only for the cases of RPI > 400, improvement actions have been implemented that allowed a reduction of RPI values between 25% to 70% with a costs increment of < 1%. FMEA technique can be applied to the processes of a clinical laboratory, even if of small dimensions, and offers a high potential of improvement. Nevertheless, such activity needs a thorough planning because it is complex, even if the laboratory already operates an ISO 9000 Quality Management System.

Interferometer for Space Station Windows

NASA Technical Reports Server (NTRS)

Hall, Gregory

2003-01-01

Inspection of space station windows for micrometeorite damage would be a difficult task insitu using current inspection techniques. Commercially available optical profilometers and inspection systems are relatively large, about the size of a desktop computer tower, and require a stable platform to inspect the test object. Also, many devices currently available are designed for a laboratory or controlled environments requiring external computer control. This paper presents an approach using a highly developed optical interferometer to inspect the windows from inside the space station itself using a self- contained hand held device. The interferometer would be capable as a minimum of detecting damage as small as one ten thousands of an inch in diameter and depth while interrogating a relatively large area. The current developmental state of this device is still in the proof of concept stage. The background section of this paper will discuss the current state of the art of profilometers as well as the desired configuration of the self-contained, hand held device. Then, a discussion of the developments and findings that will allow the configuration change with suggested approaches appearing in the proof of concept section.

High-throughput screening technologies for botulinum neurotoxins.

PubMed

Bompiani, Kristin M; Dickerson, Tobin J

2014-01-01

Botulinum neurotoxins (BoNTs) are a class of bacterial neurotoxins that are the most potent toxic compounds reported to date. Exposure to relatively low concentrations of the toxin protein can result in major muscle paralysis, which may result in death in severe cases. In addition to their role in natural human disease, BoNTs are currently under close scrutiny because of their potential to be used as biowarfare agents. Clinical treatment options for botulism are currently limited, and finite stockpiles of antitoxin exist. In light of current bioterrorist threats, researchers have focused on identifying new molecules that can be applied to either sensitive toxin detection or improved clinical treatment. High-throughput screening (HTS) is a laboratory technique commonly employed to screen large libraries of diverse compounds based on specific compound binding capabilities or function. Here we review existing HTS platforms that have been applied to identify novel BoNT diagnostic or therapeutic agents. HTS platforms for screening antibodies, peptides, small molecules, and aptamers are described, as well as the screening results and current progress of the identified compounds.

Field Emission Properties of Carbon Nanotube Fibers and Sheets for a High Current Electron Source

NASA Astrophysics Data System (ADS)

Christy, Larry

Field emission (FE) properties of carbon nanotube (CNT) fibers from Rice University and the University of Cambridge have been studied for use within a high current electron source for a directed energy weapon. Upon reviewing the performance of these two prevalent CNT fibers, cathodes were designed with CNT fibers from the University of Cincinnati Nanoworld Laboratory. Cathodes composed of a single CNT fiber, an array of three CNT fibers, and a nonwoven CNT sheet were investigated for FE properties; the goal was to design a cathode with emission current in excess of 10 mA. Once the design phase was complete, the cathode samples were fabricated, characterized, and then analyzed to determine FE properties. Electrical conductivity of the CNT fibers was characterized with a 4-probe technique. FE characteristics were measured in an ultra-high vacuum chamber at Wright-Patterson Air Force Base. The arrayed CNT fiber and the enhanced nonwoven CNT sheet emitter design demonstrated the most promising FE properties. Future work will include further analysis and cathode design using this nonwoven CNT sheet material to increase peak current performance during electron emission.

Paper-based analytical devices for clinical diagnosis: recent advances in the fabrication techniques and sensing mechanisms

PubMed Central

Sher, Mazhar; Zhuang, Rachel; Demirci, Utkan; Asghar, Waseem

2017-01-01

Introduction There is a significant interest in developing inexpensive portable biosensing platforms for various applications including disease diagnostics, environmental monitoring, food safety, and water testing at the point-of-care (POC) settings. Current diagnostic assays available in the developed world require sophisticated laboratory infrastructure and expensive reagents. Hence, they are not suitable for resource-constrained settings with limited financial resources, basic health infrastructure, and few trained technicians. Cellulose and flexible transparency paper-based analytical devices have demonstrated enormous potential for developing robust, inexpensive and portable devices for disease diagnostics. These devices offer promising solutions to disease management in resource-constrained settings where the vast majority of the population cannot afford expensive and highly sophisticated treatment options. Areas covered In this review, the authors describe currently developed cellulose and flexible transparency paper-based microfluidic devices, device fabrication techniques, and sensing technologies that are integrated with these devices. The authors also discuss the limitations and challenges associated with these devices and their potential in clinical settings. Expert commentary In recent years, cellulose and flexible transparency paper-based microfluidic devices have demonstrated the potential to become future healthcare options despite a few limitations such as low sensitivity and reproducibility. PMID:28103450

Paper-based analytical devices for clinical diagnosis: recent advances in the fabrication techniques and sensing mechanisms.

PubMed

Sher, Mazhar; Zhuang, Rachel; Demirci, Utkan; Asghar, Waseem

2017-04-01

There is a significant interest in developing inexpensive portable biosensing platforms for various applications including disease diagnostics, environmental monitoring, food safety, and water testing at the point-of-care (POC) settings. Current diagnostic assays available in the developed world require sophisticated laboratory infrastructure and expensive reagents. Hence, they are not suitable for resource-constrained settings with limited financial resources, basic health infrastructure, and few trained technicians. Cellulose and flexible transparency paper-based analytical devices have demonstrated enormous potential for developing robust, inexpensive and portable devices for disease diagnostics. These devices offer promising solutions to disease management in resource-constrained settings where the vast majority of the population cannot afford expensive and highly sophisticated treatment options. Areas covered: In this review, the authors describe currently developed cellulose and flexible transparency paper-based microfluidic devices, device fabrication techniques, and sensing technologies that are integrated with these devices. The authors also discuss the limitations and challenges associated with these devices and their potential in clinical settings. Expert commentary: In recent years, cellulose and flexible transparency paper-based microfluidic devices have demonstrated the potential to become future healthcare options despite a few limitations such as low sensitivity and reproducibility.

Interlaboratory comparison measurements of aspheres

NASA Astrophysics Data System (ADS)

Schachtschneider, R.; Fortmeier, I.; Stavridis, M.; Asfour, J.; Berger, G.; Bergmann, R. B.; Beutler, A.; Blümel, T.; Klawitter, H.; Kubo, K.; Liebl, J.; Löffler, F.; Meeß, R.; Pruss, C.; Ramm, D.; Sandner, M.; Schneider, G.; Wendel, M.; Widdershoven, I.; Schulz, M.; Elster, C.

2018-05-01

The need for high-quality aspheres is rapidly growing, necessitating increased accuracy in their measurement. A reliable uncertainty assessment of asphere form measurement techniques is difficult due to their complexity. In order to explore the accuracy of current asphere form measurement techniques, an interlaboratory comparison was carried out in which four aspheres were measured by eight laboratories using tactile measurements, optical point measurements, and optical areal measurements. Altogether, 12 different devices were employed. The measurement results were analysed after subtracting the design topography and subsequently a best-fit sphere from the measurements. The surface reduced in this way was compared to a reference topography that was obtained by taking the pointwise median across the ensemble of reduced topographies on a 1000 × 1000 Cartesian grid. The deviations of the reduced topographies from the reference topography were analysed in terms of several characteristics including peak-to-valley and root-mean-square deviations. Root-mean-square deviations of the reduced topographies from the reference topographies were found to be on the order of some tens of nanometres up to 89 nm, with most of the deviations being smaller than 20 nm. Our results give an indication of the accuracy that can currently be expected in form measurements of aspheres.

Practicing for Mars: The International Space Station (ISS) as a Testbed

NASA Technical Reports Server (NTRS)

Korth, David H.

2014-01-01

Allows demonstration and development of exploration capabilities to help accomplish future missions sooner with less risk to crew and mission Characteristics of ISS as a testbed High fidelity human operations platform in LEO: Continuously operating habitat and active laboratory. High fidelity systems. Astronauts as test subjects. Highly experienced ground operations teams. Offers a controlled test environment.: Consequences to systems performance and decision making not offered in ground analogs International participation. Continuously improving system looking for new technology and ideas to improve operations. Technology Demos & Critical Systems Maturation. Human Health and Performance. Operations Simulations and Techniques. Exploration prep testing on ISS has been ongoing since 2012. Number of tests increasing with each ISS expedition. One Year Crew Expedition starting in Spring 2015. ROSCOSMOS and NASA are partnering on the Participating Crew are Mikhail Kornienko and Scott Kelly Majority of testing is an extension of current Human Biomedical Research investigations Plan for extending & expanding upon current operations techniques and tech demo studies ESA 10 Day Mission in Fall 2015 ESA astronaut focus on testing exploration technologies Many more opportunities throughout the life of ISS! 4/24/2014 david.h.korth@nasa.gov 4 Exploration testing

Development of an Acoustic Localization Method for Cavitation Experiments in Reverberant Environments

NASA Astrophysics Data System (ADS)

Ranjeva, Minna; Thompson, Lee; Perlitz, Daniel; Bonness, William; Capone, Dean; Elbing, Brian

2011-11-01

Cavitation is a major concern for the US Navy since it can cause ship damage and produce unwanted noise. The ability to precisely locate cavitation onset in laboratory scale experiments is essential for proper design that will minimize this undesired phenomenon. Measuring the cavitation onset is more accurately determined acoustically than visually. However, if other parts of the model begin to cavitate prior to the component of interest the acoustic data is contaminated with spurious noise. Consequently, cavitation onset is widely determined by optically locating the event of interest. The current research effort aims at developing an acoustic localization scheme for reverberant environments such as water tunnels. Currently cavitation bubbles are being induced in a static water tank with a laser, allowing the localization techniques to be refined with the bubble at a known location. The source is located with the use of acoustic data collected with hydrophones and analyzed using signal processing techniques. To verify the accuracy of the acoustic scheme, the events are simultaneously monitored visually with the use of a high speed camera. Once refined testing will be conducted in a water tunnel. This research was sponsored by the Naval Engineering Education Center (NEEC).

Rapid Analysis of Carbohydrates in Bioprocess Samples: An Evaluation of the CarboPac SA10 for HPAE-PAD Analysis by Interlaboratory Comparison

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

Sevcik, R. S.; Hyman, D. A.; Basumallich, L.

2013-01-01

A technique for carbohydrate analysis for bioprocess samples has been developed, providing reduced analysis time compared to current practice in the biofuels R&D community. The Thermofisher CarboPac SA10 anion-exchange column enables isocratic separation of monosaccharides, sucrose and cellobiose in approximately 7 minutes. Additionally, use of a low-volume (0.2 mL) injection valve in combination with a high-volume detection cell minimizes the extent of sample dilution required to bring sugar concentrations into the linear range of the pulsed amperometric detector (PAD). Three laboratories, representing academia, industry, and government, participated in an interlaboratory study which analyzed twenty-one opportunistic samples representing biomass pretreatment, enzymaticmore » saccharification, and fermentation samples. The technique's robustness, linearity, and interlaboratory reproducibility were evaluated and showed excellent-to-acceptable characteristics. Additionally, quantitation by the CarboPac SA10/PAD was compared with the current practice method utilizing a HPX-87P/RID. While these two methods showed good agreement a statistical comparison found significant quantitation difference between them, highlighting the difference between selective and universal detection modes.« less

Comparative study of electromechanical impedance and Lamb wave techniques for fatigue crack detection and monitoring in metallic structures

NASA Astrophysics Data System (ADS)

Lim, Say Ian; Liu, Yu; Soh, Chee Kiong

2012-04-01

Fatigue cracks often initiate at the weld toes of welded steel connections. Usually, these cracks cannot be identified by the naked eyes. Existing identification methods like dye-penetration test and alternating current potential drop (ACPD) may be useful for detecting fatigue cracks at the weld toes. To apply these non-destructive evaluation (NDE) techniques, the potential sites have to be accessible during inspection. Therefore, there is a need to explore other detection and monitoring techniques for fatigue cracks especially when their locations are inaccessible or cost of access is uneconomical. Electro-mechanical Impedance (EMI) and Lamb wave techniques are two fast growing techniques in the Structural Health Monitoring (SHM) community. These techniques use piezoelectric ceramics (PZT) for actuation and sensing. Since the monitoring site is only needed to be accessed once for the instrumentation of the transducers, remote monitoring is made possible. The permanent locations of these transducers also translate to having consistent measurement for monitoring. The main focus of this study is to conduct a comparative investigation on the effectiveness and efficiency of the EMI technique and the Lamb wave technique for successful fatigue crack identification and monitoring of welded steel connections using piezoelectric transducers. A laboratory-sized non-load carrying fillet weld specimen is used in this study. The specimen is subjected to cyclic tensile load and data for both techniques are acquired at stipulated intervals. It can be concluded that the EMI technique is sensitive to the crack initiation phase while the Lamb wave technique correlates well with the crack propagation phase.

Active cleaning technique device

NASA Technical Reports Server (NTRS)

Shannon, R. L.; Gillette, R. B.

1973-01-01

The objective of this program was to develop a laboratory demonstration model of an active cleaning technique (ACT) device. The principle of this device is based primarily on the technique for removing contaminants from optical surfaces. This active cleaning technique involves exposing contaminated surfaces to a plasma containing atomic oxygen or combinations of other reactive gases. The ACT device laboratory demonstration model incorporates, in addition to plasma cleaning, the means to operate the device as an ion source for sputtering experiments. The overall ACT device includes a plasma generation tube, an ion accelerator, a gas supply system, a RF power supply and a high voltage dc power supply.

Demonstrating Bacterial Flagella.

ERIC Educational Resources Information Center

Porter, John R.; And Others

1992-01-01

Describes an effective laboratory method for demonstrating bacterial flagella that utilizes the Proteus mirabilis organism and a special harvesting technique. Includes safety considerations for the laboratory exercise. (MDH)

Improvement of laboratory turnaround time using lean methodology.

PubMed

Gupta, Shradha; Kapil, Sahil; Sharma, Monica

2018-05-14

Purpose The purpose of this paper is to discuss the implementation of lean methodology to reduce the turnaround time (TAT) of a clinical laboratory in a super speciality hospital. Delays in report delivery lead to delayed diagnosis increased waiting time and decreased customer satisfaction. The reduction in TAT will lead to increased patient satisfaction, quality of care, employee satisfaction and ultimately the hospital's revenue. Design/methodology/approach The generic causes resulting in increasing TAT of clinical laboratories were identified using lean tools and techniques such as value stream mapping (VSM), Gemba, Pareto Analysis and Root Cause Analysis. VSM was used as a tool to analyze the current state of the process and further VSM was used to design the future state with suggestions for process improvements. Findings This study identified 12 major non-value added factors for the hematology laboratory and 5 major non-value added factors for the biochemistry lab which were acting as bottlenecks resulting in limiting throughput. A four-month research study by the authors together with hospital quality department and laboratory staff members led to reduction of the average TAT from 180 to 95minutes in the hematology lab and from 268 to 208 minutes in the biochemistry lab. Practical implications Very few improvement initiatives in Indian healthcare are based on industrial engineering tools and techniques, which might be due to a lack of interaction between healthcare and engineering. The study provides a positive outcome in terms of improving the efficiency of services in hospitals and identifies a scope for lean in the Indian healthcare sector. Social implications Applying lean in the Indian healthcare sector gives its own potential solution to the problem caused, due to a wide gap between lean accessibility and lean implementation. Lean helped in changing the mindset of an organization toward providing the highest quality of services with faster delivery at an optimal cost. Originality/value This paper is an effort to reduce the gap between healthcare and industrial engineering and enhancing the use of lean practices in Indian healthcare. The study is motivated toward implementing lean methodology successfully in services.

Aseptic Laboratory Techniques: Plating Methods

PubMed Central

Sanders, Erin R.

2012-01-01

Microorganisms are present on all inanimate surfaces creating ubiquitous sources of possible contamination in the laboratory. Experimental success relies on the ability of a scientist to sterilize work surfaces and equipment as well as prevent contact of sterile instruments and solutions with non-sterile surfaces. Here we present the steps for several plating methods routinely used in the laboratory to isolate, propagate, or enumerate microorganisms such as bacteria and phage. All five methods incorporate aseptic technique, or procedures that maintain the sterility of experimental materials. Procedures described include (1) streak-plating bacterial cultures to isolate single colonies, (2) pour-plating and (3) spread-plating to enumerate viable bacterial colonies, (4) soft agar overlays to isolate phage and enumerate plaques, and (5) replica-plating to transfer cells from one plate to another in an identical spatial pattern. These procedures can be performed at the laboratory bench, provided they involve non-pathogenic strains of microorganisms (Biosafety Level 1, BSL-1). If working with BSL-2 organisms, then these manipulations must take place in a biosafety cabinet. Consult the most current edition of the Biosafety in Microbiological and Biomedical Laboratories (BMBL) as well as Material Safety Data Sheets (MSDS) for Infectious Substances to determine the biohazard classification as well as the safety precautions and containment facilities required for the microorganism in question. Bacterial strains and phage stocks can be obtained from research investigators, companies, and collections maintained by particular organizations such as the American Type Culture Collection (ATCC). It is recommended that non-pathogenic strains be used when learning the various plating methods. By following the procedures described in this protocol, students should be able to: ● Perform plating procedures without contaminating media. ● Isolate single bacterial colonies by the streak-plating method. ● Use pour-plating and spread-plating methods to determine the concentration of bacteria. ● Perform soft agar overlays when working with phage. ● Transfer bacterial cells from one plate to another using the replica-plating procedure. ● Given an experimental task, select the appropriate plating method. PMID:22617405

Management of urinary tract infections in patients with neurogenic bladder: challenges and solutions.

PubMed

Pannek, Jürgen; Wöllner, Jens

2017-01-01

Urinary tract infections (UTIs) are one of the most common morbidities in persons with neurogenic lower urinary tract dysfunction (NLUTD). They are associated with a significant morbidity and mortality, and they affect the quality of life of the affected patients. Diagnosis and treatment of UTI in this group of patients are challenging. In this review, the current strategies regarding diagnosis, treatment, and prevention are summarized. it is important to correctly diagnose a UTI, as treatment of bacteriuria should strictly be avoided. A UTI is defined as a combination of laboratory findings (leukocyturia and bacteriuria) and symptoms. Laboratory findings without symptoms are classified as asymptomatic bacteriuria. Routine urine screening is not advised. Only UTI should be treated; treatment of asymptomatic bacteriuria is not indicated. Prior to treatment, urine for a urine culture should be obtained. Antibiotic treatment for ~7 days is advised. In recurrent UTI, bladder management should be optimized and morphologic causes for UTI should be excluded. If UTIs persist, medical prophylaxis should be considered. Currently, no prophylactic measure with evidence-based efficacy exists. Long-term antibiotic prophylaxis should be used merely as an ultimate measure. Among the various mentioned innovative approaches for UTI prevention, bacteriophages, intravesical instillations, complementary and alternative medicine techniques, and probiotics seem to be most promising. Recently, several promising innovative options for UTI prophylaxis have been developed which may help overcome the current therapeutic dilemma. However, further well designed studies are necessary to evaluate the safety and efficacy of these approaches.

Current trends in protein crystallization.

PubMed

Gavira, José A

2016-07-15

Proteins belong to the most complex colloidal system in terms of their physicochemical properties, size and conformational-flexibility. This complexity contributes to their great sensitivity to any external change and dictate the uncertainty of crystallization. The need of 3D models to understand their functionality and interaction mechanisms with other neighbouring (macro)molecules has driven the tremendous effort put into the field of crystallography that has also permeated other fields trying to shed some light into reluctant-to-crystallize proteins. This review is aimed at revising protein crystallization from a regular-laboratory point of view. It is also devoted to highlight the latest developments and achievements to produce, identify and deliver high-quality protein crystals for XFEL, Micro-ED or neutron diffraction. The low likelihood of protein crystallization is rationalized by considering the intrinsic polypeptide nature (folded state, surface charge, etc) followed by a description of the standard crystallization methods (batch, vapour diffusion and counter-diffusion), including high throughput advances. Other methodologies aimed at determining protein features in solution (NMR, SAS, DLS) or to gather structural information from single particles such as Cryo-EM are also discussed. Finally, current approaches showing the convergence of different structural biology techniques and the cross-methodologies adaptation to tackle the most difficult problems, are presented. Current advances in biomacromolecules crystallization, from nano crystals for XFEL and Micro-ED to large crystals for neutron diffraction, are covered with special emphasis in methodologies applicable at laboratory scale. Copyright © 2015 Elsevier Inc. All rights reserved.

Nanoparticle exposure biomonitoring: exposure/effect indicator development approaches

NASA Astrophysics Data System (ADS)

Marie-Desvergne, C.; Dubosson, M.; Lacombe, M.; Brun, V.; Mossuz, V.

2015-05-01

The use of engineered nanoparticles (NP) is more and more widespread in various industrial sectors. The inhalation route of exposure is a matter of concern (adverse effects of air pollution by ultrafine particles and asbestos). No NP biomonitoring recommendations or standards are available so far. The LBM laboratory is currently studying several approaches to develop bioindicators for occupational health applications. As regards exposure indicators, new tools are being implemented to assess potentially inhaled NP in non-invasive respiratory sampling (nasal sampling and exhaled breath condensates (EBC)). Diverse NP analytical characterization methods are used (ICP-MS, dynamic light scattering and electron microscopy coupled to energy-dispersive X-ray analysis). As regards effect indicators, a methodology has been developed to assess a range of 29 cytokines in EBCs (potential respiratory inflammation due to NP exposure). Secondly, collaboration between the LBM laboratory and the EDyp team has allowed the EBC proteome to be characterized by means of an LC-MS/MS process. These projects are expected to facilitate the development of individual NP exposure biomonitoring tools and the analysis of early potential impacts on health. Innovative techniques such as field-flow fractionation combined with ICP-MS and single particle-ICPMS are currently being explored. These tools are directly intended to assist occupational physicians in the identification of exposure situations.

Measurement of discharge using tracers

USGS Publications Warehouse

Kilpatrick, F.A.; Cobb, Ernest D.

1985-01-01

The development of fluorescent dyes and fluorometers that can measure these dyes at very low concentrations has made dye-dilution methods practical for measuring discharge. These methods are particularly useful for determining discharge under certain flow conditions that are unfavorable for current meter measurements. These include small streams, canals, and pipes where 1. Turbulence is excessive for current-meter measurement but conducive to good mixing. 2. Moving rocks and debris may damage instruments placed in the flow. 3. Cross-sectional areas or velocities are indeterminate or changing. 4. The flow is unsteady, such as the flow that exists with storm-runoff events on small streams and urban storm-sewer systems. 5. The flow is physically inaccessible or unsafe. From a practical standpoint, such methods are limited primarily to small streams, because of the excessively long channel-mixing lengths required for larger streams. Very good accuracy can be obtained provided that 1. Adequate mixing length and time are allowed. 2. Careful field and laboratory techniques are used. 3. Dye losses are not significant. This manual describes the slug-injection and constant-rate injection methods of performing tracer-dilution measurements. Emphasis is on the use of fluorescent dyes as tracers and the equipment, field methods, and laboratory procedures for performing such measurements. The tracer-velocity method is also briefly discussed.