Modeling and Detection of Ice Particle Accretion in Aircraft Engine Compression Systems

NASA Technical Reports Server (NTRS)

May, Ryan D.; Simon, Donald L.; Guo, Ten-Huei

2012-01-01

The accretion of ice particles in the core of commercial aircraft engines has been an ongoing aviation safety challenge. While no accidents have resulted from this phenomenon to date, numerous engine power loss events ranging from uneventful recoveries to forced landings have been recorded. As a first step to enabling mitigation strategies during ice accretion, a detection scheme must be developed that is capable of being implemented on board modern engines. In this paper, a simple detection scheme is developed and tested using a realistic engine simulation with approximate ice accretion models based on data from a compressor design tool. These accretion models are implemented as modified Low Pressure Compressor maps and have the capability to shift engine performance based on a specified level of ice blockage. Based on results from this model, it is possible to detect the accretion of ice in the engine core by observing shifts in the typical sensed engine outputs. Results are presented in which, for a 0.1 percent false positive rate, a true positive detection rate of 98 percent is achieved.

An approach to evaluating reactive airborne wind shear systems

NASA Technical Reports Server (NTRS)

Gibson, Joseph P., Jr.

1992-01-01

An approach to evaluating reactive airborne windshear detection systems was developed to support a deployment study for future FAA ground-based windshear detection systems. The deployment study methodology assesses potential future safety enhancements beyond planned capabilities. The reactive airborne systems will be an integral part of planned windshear safety enhancements. The approach to evaluating reactive airborne systems involves separate analyses for both landing and take-off scenario. The analysis estimates the probability of effective warning considering several factors including NASA energy height loss characteristics, reactive alert timing, and a probability distribution for microburst strength.

Sleepiness and Safety: Where Biology Needs Technology.

PubMed

Abe, Takashi; Mollicone, Daniel; Basner, Mathias; Dinges, David F

2014-04-01

Maintaining human alertness and behavioral capability under conditions of sleep loss and circadian misalignment requires fatigue management technologies due to: (1) dynamic nonlinear modulation of performance capability by the interaction of sleep homeostatic drive and circadian regulation; (2) large differences among people in neurobehavioral vulnerability to sleep loss; (3) error in subjective estimates of fatigue on performance; and (4) to inform people of the need for recovery sleep. Two promising areas of technology have emerged for managing fatigue risk in safety-sensitive occupations. The first involves preventing fatigue by optimizing work schedules using biomathematical models of performance changes associated with sleep homeostatic and circadian dynamics. Increasingly these mathematical models account for individual differences to achieve a more accurate estimate of the timing and magnitude of fatigue effects on individuals. The second area involves technologies for detecting transient fatigue from drowsiness. The Psychomotor Vigilance Test (PVT), which has been extensively validated to be sensitive to deficits in attention from sleep loss and circadian misalignment, is an example in this category. Two shorter-duration versions of the PVT recently have been developed for evaluating whether operators have sufficient behavioral alertness prior to or during work. Another example is online tracking the percent of slow eyelid closures (PERCLOS), which has been shown to reflect momentary fluctuations of vigilance. Technologies for predicting and detecting sleepiness/fatigue have the potential to predict and prevent operator errors and accidents in safety-sensitive occupations, as well as physiological and mental diseases due to inadequate sleep and circadian misalignment.

Mars Express MARSIS Radar: A Prediction of the Effect of Overlying Ice on Detecting Polar Basal Lakes and Inter-Glacial Aquifers

NASA Technical Reports Server (NTRS)

Farrell, W. M.; Plaut, J. J.; Gurnett, D. A.; Picardi, G.

2004-01-01

The penetration of the MARSIS radar signal into the polar ice mass is modeled to determine the capability of the instrument to locate sub-glacial aquifers. As a ground penetrating radar, the orbiting MARSIS transmits a signal greater than 1 W between 1-5 MHz. In this work we will investigate the effect of ice conductive losses on the radar-detection of subsurface aquifers. Based on wave propagation analysis, it is found that for a bulk ice conductivity below 10-5 S/m, conductive losses in the medium are not significant. However, if the bulk ice conductivity is relatively large (greater than 10-5 S/m), the reflected signal from any deep aquifer will be absorbed as it propagates in the lossy ice medium limiting the probing depth.

Scalable Algorithms for Global Scale Remote Sensing Applications

NASA Astrophysics Data System (ADS)

Vatsavai, R. R.; Bhaduri, B. L.; Singh, N.

2015-12-01

Recent decade has witnessed major changes on the Earth, for example, deforestation, varying cropping and human settlement patterns, and crippling damages due to disasters. Accurate damage assessment caused by major natural and anthropogenic disasters is becoming critical due to increases in human and economic loss. This increase in loss of life and severe damages can be attributed to the growing population, as well as human migration to the disaster prone regions of the world. Rapid assessment of these changes and dissemination of accurate information is critical for creating an effective emergency response. Change detection using high-resolution satellite images is a primary tool in assessing damages, monitoring biomass and critical infrastructures, and identifying new settlements. Existing change detection methods suffer from registration errors and often based on pixel (location) wise comparison of spectral observations from single sensor. In this paper we present a novel probabilistic change detection framework based on patch comparison and a GPU implementation that supports near real-time rapid damage exploration capability.

High-frequency acoustic spectrum analyzer based on polymer integrated optics

NASA Astrophysics Data System (ADS)

Yacoubian, Araz

This dissertation presents an acoustic spectrum analyzer based on nonlinear polymer-integrated optics. The device is used in a scanning heterodyne geometry by zero biasing a Michelson interferometer. It is capable of detecting vibrations from DC to the GHz range. Initial low frequency experiments show that the device is an effective tool for analyzing an acoustic spectrum even in noisy environments. Three generations of integrated sensors are presented, starting with a very lossy (86 dB total insertion loss) initial device that detects vibrations as low as λ/10, and second and third generation improvements with a final device of 44 dB total insertion loss. The sensor was further tested for detecting a pulsed laser-excited vibration and resonances due to the structure of the sample. The data are compared to the acoustic spectrum measured using a low loss passive fiber interferometer detection scheme which utilizes a high speed detector. The peaks present in the passive detection scheme are clearly visible with our sensor data, which have a lower noise floor. Hybrid integration of GHz electronics is also investigated in this dissertation. A voltage controlled oscillator (VCO) is integrated on a polymer device using a new approach. The VCO is shown to operate as specified by the manufacturer, and the RF signal is efficiently launched onto the micro-strip line used for EO modulation. In the future this technology can be used in conjunction with the presented sensor to produce a fully integrated device containing high frequency drive electronics controlled by low DC voltage. Issues related to device fabrication, loss analysis, RF power delivery to drive circuitry, efficient poling of large area samples, and optimizing poling conditions are also discussed throughout the text.

Plasmid expression and maintenance during long-term starvation-survival of bacteria in well water.

PubMed Central

Caldwell, B A; Ye, C; Griffiths, R P; Moyer, C L; Morita, R Y

1989-01-01

Strains of enteric bacteria and pseudomonads containing plasmid R388::Tnl721 (Tpr, Tcr) or pRO101 (Hgr, Tcr) were starved for over 250 days in sterile well water to evaluate effects of starvation-survival on plasmid expression and maintenance. Viable populations dropped to between approximately 0.1 and 1% of the initial populations. Escherichia coli(pRO101) and Pseudomonas cepacia(pRO101) lost both viability and plasmid expression at a lower rate than strains containing R388::Tnl721. Three patterns of host-plasmid interaction were detected: (i) no apparent loss of plasmid expression, (ii) loss of plasmid expression on initial recovery with subsequent expression upon resuscitation, and (iii) loss of capability to produce functional plasmid resistance. PMID:2782868

Real-Time Model-Based Leak-Through Detection within Cryogenic Flow Systems

NASA Technical Reports Server (NTRS)

Walker, M.; Figueroa, F.

2015-01-01

The timely detection of leaks within cryogenic fuel replenishment systems is of significant importance to operators on account of the safety and economic impacts associated with material loss and operational inefficiencies. Associated loss in control of pressure also effects the stability and ability to control the phase of cryogenic fluids during replenishment operations. Current research dedicated to providing Prognostics and Health Management (PHM) coverage of such cryogenic replenishment systems has focused on the detection of leaks to atmosphere involving relatively simple model-based diagnostic approaches that, while effective, are unable to isolate the fault to specific piping system components. The authors have extended this research to focus on the detection of leaks through closed valves that are intended to isolate sections of the piping system from the flow and pressurization of cryogenic fluids. The described approach employs model-based detection of leak-through conditions based on correlations of pressure changes across isolation valves and attempts to isolate the faults to specific valves. Implementation of this capability is enabled by knowledge and information embedded in the domain model of the system. The approach has been used effectively to detect such leak-through faults during cryogenic operational testing at the Cryogenic Testbed at NASA's Kennedy Space Center.

Studying Cold Nuclear Matter with the MPC-EX of PHENIX

NASA Astrophysics Data System (ADS)

Grau, Nathan; Phenix Collaboration

2017-09-01

Highly asymmetric collision systems, such as d+Au, provide a unique environment to study cold nuclear matter. Potential measurements range from pinning down the modification of the nuclear wave function, i.e. saturation, to studying final state interactions, i.e. energy loss. The PHENIX experiment has enhanced the muon piston calorimeter (MPC) with a silicon-tungsten preshower, the MPC-EX. With its fine segmentation the MPC-EX extends the photon detection capability at 3 < | η | < 3.8. In this talk we review the current status of the detector, its calibration, and its identification capabilities using the 2016 d+Au dataset. We also discuss the specific physics observables the MPC-EX can measure.

Arthritogenic alphaviral infection perturbs osteoblast function and triggers pathologic bone loss

PubMed Central

Chen, Weiqiang; Foo, Suan-Sin; Rulli, Nestor E.; Taylor, Adam; Sheng, Kuo-Ching; Herrero, Lara J.; Herring, Belinda L.; Lidbury, Brett A.; Li, Rachel W.; Walsh, Nicole C.; Sims, Natalie A.; Smith, Paul N.; Mahalingam, Suresh

2014-01-01

Arthritogenic alphaviruses including Ross River virus (RRV), Sindbis virus, and chikungunya virus cause worldwide outbreaks of musculoskeletal disease. The ability of alphaviruses to induce bone pathologies remains poorly defined. Here we show that primary human osteoblasts (hOBs) can be productively infected by RRV. RRV-infected hOBs produced high levels of inflammatory cytokine including IL-6. The RANKL/OPG ratio was disrupted in the synovial fluid of RRV patients, and this was accompanied by an increase in serum Tartrate-resistant acid phosphatase 5b (TRAP5b) levels. Infection of bone cells with RRV was validated using an established RRV murine model. In wild-type mice, infectious virus was detected in the femur, tibia, patella, and foot, together with reduced bone volume in the tibial epiphysis and vertebrae detected by microcomputed tomographic (µCT) analysis. The RANKL/OPG ratio was also disrupted in mice infected with RRV; both this effect and the bone loss were blocked by treatment with an IL-6 neutralizing antibody. Collectively, these findings provide previously unidentified evidence that alphavirus infection induces bone loss and that OBs are capable of producing proinflammatory mediators during alphavirus-induced arthralgia. The perturbed RANKL/OPG ratio in RRV-infected OBs may therefore contribute to bone loss in alphavirus infection. PMID:24733914

Compact multiwire proportional counters for the detection of fission fragments

NASA Astrophysics Data System (ADS)

Jhingan, Akhil; Sugathan, P.; Golda, K. S.; Singh, R. P.; Varughese, T.; Singh, Hardev; Behera, B. R.; Mandal, S. K.

2009-12-01

Two large area multistep position sensitive (two dimensional) multiwire proportional counters have been developed for experiments involving study of fission dynamics using general purpose scattering chamber facility at IUAC. Both detectors have an active area of 20×10 cm2 and provide position signals in horizontal (X) and vertical (Y) planes, timing signal for time of flight measurements and energy signal giving the differential energy loss in the active volume. The design features are optimized for the detection of low energy heavy ions at very low gas pressures. Special care was taken in setting up the readout electronics, constant fraction discriminators for position signals in particular, to get optimum position and timing resolutions along with high count rate handling capability of low energy heavy ions. A custom made charge sensitive preamplifier, having lower gain and shorter decay time, has been developed for extracting the differential energy loss signal. The position and time resolutions of the detectors were determined to be 1.1 mm full width at half maximum (FWHM) and 1.7 ns FWHM, respectively. The detector could handle heavy ion count rates exceeding 20 kHz without any breakdown. Time of flight signal in combination with differential energy loss signal gives a clean separation of fission fragments from projectile and target like particles. The timing and position signals of the detectors are used for fission coincidence measurements and subsequent extraction of their mass, angular, and total kinetic energy distributions. This article describes systematic study of these fission counters in terms of efficiency, time resolution, count rate handling capability, position resolution, and the readout electronics. The detector has been operated with both five electrode geometry and four electrode geometry, and a comparison has been made in their performances.

Pulsed eddy current inspection of broach support plates in steam generators

NASA Astrophysics Data System (ADS)

Mokros, Sarah Gwendolyn

Steam Generators (SGs) are a critical component of nuclear reactors, employing thousands of SG tubes to convert heat generated in the reactor core into useable energy. SG tubes are supported at numerous locations by Broach Support Plates (BSPs) that have trefoil shaped holes, which prevent excessive tube vibrations, while allowing water to easily flow through the support structures. A number of degradation modes occur in SGs, such as SG tube fretting, cracking or denting, requiring periodic inspection. Currently, conventional Eddy Current Testing (ECT) is used to non-destructively assess the condition of SG tubes and components. However, as reactors age, new modes of degradation will likely appear that may be difficult to detect and characterize using conventional ECT, such as wall loss in BSPs and build-up of corrosion products, which typically form as a hard sludge called magnetite. Pulsed Eddy Current (PEC) technologies are an emerging technique that is presented in this work as a method to further advance inspection techniques used in CANDURTM nuclear reactors. A PEC probe was designed to inspect the unique shape of the trefoil shaped hole to detect and characterize wall loss and the presence of magnetite in A516 carbon steel BSPs with trefoil shaped holes from within 15.9 mm (5/8") Alloy-800 SG tubes. PEC was also used to observe how measurements of wall loss were affected by the presence of magnetite. This work presents Finite Element Method (FEM) simulations and experimental results collected to observe these degradation modes. The probe was demonstrated to be capable of detecting far side wall loss as low as 20%, locating and characterizing the relative permeability of magnetite, and of detecting wall loss when magnetite was present. FEM simulations and experimental results were found to be in good agreement, suggesting that additional investigations of the effects of BSP degradation on PEC signal response may also be performed using FEM models.

Detection of clinically relevant copy number alterations in oral cancer progression using multiplexed droplet digital PCR.

PubMed

Hughesman, Curtis B; Lu, X J David; Liu, Kelly Y P; Zhu, Yuqi; Towle, Rebecca M; Haynes, Charles; Poh, Catherine F

2017-09-19

Copy number alterations (CNAs), a common genomic event during carcinogenesis, are known to affect a large fraction of the genome. Common recurrent gains or losses of specific chromosomal regions occur at frequencies that they may be considered distinctive features of tumoral cells. Here we introduce a novel multiplexed droplet digital PCR (ddPCR) assay capable of detecting recurrent CNAs that drive tumorigenesis of oral squamous cell carcinoma. Applied to DNA extracted from oral cell lines and clinical samples of various disease stages, we found good agreement between CNAs detected by our ddPCR assay with those previously reported using comparative genomic hybridization or single nucleotide polymorphism arrays. Furthermore, we demonstrate that the ability to target specific locations of the genome permits detection of clinically relevant oncogenic events such as small, submicroscopic homozygous deletions. Additional capabilities of the multiplexed ddPCR assay include the ability to infer ploidy level, quantify the change in copy number of target loci with high-level gains, and simultaneously assess the status and viral load for high-risk human papillomavirus types 16 and 18. This novel multiplexed ddPCR assay therefore may have clinical value in differentiating between benign oral lesions from those that are at risk of progressing to oral cancer.

Simulation of electron energy loss spectra of nanomaterials with linear-scaling density functional theory

DOE PAGES

Tait, E. W.; Ratcliff, L. E.; Payne, M. C.; ...

2016-04-20

Experimental techniques for electron energy loss spectroscopy (EELS) combine high energy resolution with high spatial resolution. They are therefore powerful tools for investigating the local electronic structure of complex systems such as nanostructures, interfaces and even individual defects. Interpretation of experimental electron energy loss spectra is often challenging and can require theoretical modelling of candidate structures, which themselves may be large and complex, beyond the capabilities of traditional cubic-scaling density functional theory. In this work, we present functionality to compute electron energy loss spectra within the onetep linear-scaling density functional theory code. We first demonstrate that simulated spectra agree withmore » those computed using conventional plane wave pseudopotential methods to a high degree of precision. The ability of onetep to tackle large problems is then exploited to investigate convergence of spectra with respect to supercell size. As a result, we apply the novel functionality to a study of the electron energy loss spectra of defects on the (1 0 1) surface of an anatase slab and determine concentrations of defects which might be experimentally detectable.« less

Missing pulse detector for a variable frequency source

DOEpatents

Ingram, Charles B.; Lawhorn, John H.

1979-01-01

A missing pulse detector is provided which has the capability of monitoring a varying frequency pulse source to detect the loss of a single pulse or total loss of signal from the source. A frequency-to-current converter is used to program the output pulse width of a variable period retriggerable one-shot to maintain a pulse width slightly longer than one-half the present monitored pulse period. The retriggerable one-shot is triggered at twice the input pulse rate by employing a frequency doubler circuit connected between the one-shot input and the variable frequency source being monitored. The one-shot remains in the triggered or unstable state under normal conditions even though the source period is varying. A loss of an input pulse or single period of a fluctuating signal input will cause the one-shot to revert to its stable state, changing the output signal level to indicate a missing pulse or signal.

On-Demand Urine Analyzer

NASA Technical Reports Server (NTRS)

Farquharson, Stuart; Inscore, Frank; Shende, Chetan

2010-01-01

A lab-on-a-chip was developed that is capable of extracting biochemical indicators from urine samples and generating their surface-enhanced Raman spectra (SERS) so that the indicators can be quantified and identified. The development was motivated by the need to monitor and assess the effects of extended weightlessness, which include space motion sickness and loss of bone and muscle mass. The results may lead to developments of effective exercise programs and drug regimes that would maintain astronaut health. The analyzer containing the lab-on-a- chip includes materials to extract 3- methylhistidine (a muscle-loss indicator) and Risedronate (a bone-loss indicator) from the urine sample and detect them at the required concentrations using a Raman analyzer. The lab-on- a-chip has both an extractive material and a SERS-active material. The analyzer could be used to monitor the onset of diseases, such as osteoporosis.

Phase-locked loops and their application

NASA Technical Reports Server (NTRS)

Lindsey, W. C. (Editor); Simon, M. K.

1978-01-01

A collection of papers is presented on the characteristics and capabilities of phase-locked loops (PLLs), along with some applications of interest. The discussion covers basic theory (linear and nonlinear); acquisition; threshold; stability; frequency demodulation and detection; tracking; cycle slipping and loss of lock; phase-locked oscillators; operation and performance in the presence of noise; AGC, AFC, and APC circuits and systems; digital PLL; and applications and miscellaneous. With the rapid development of IC technology, PLLs are expected to be used widely in consumer electronics.

Concept for Inclusion of Analytical and Computational Capability in Optical Plume Anomaly Detection (OPAD) for Measurement of Neutron Flux

NASA Technical Reports Server (NTRS)

Patrick, M. Clinton; Cooper, Anita E.; Powers, W. T.

2004-01-01

Researchers are working on many konts to make possible high speed, automated classification and quantification of constituent materials in numerous environments. NASA's Marshall Space Flight Center has implemented a system for rocket engine flow fields/plumes; the Optical Plume Anomaly Detection (OPAD) system was designed to utilize emission and absorption spectroscopy for monitoring molecular and atomic particulates in gas plasma. An accompanying suite of tools and analytical package designed to utilize information collected by OPAD is known as the Engine Diagnostic Filtering System (EDIFIS). The current combination of these systems identifies atomic and molecular species and quantifies mass loss rates in H2/O2 rocket plumes. Additionally, efforts are being advanced to hardware encode components of the EDIFIS in order to address real-time operational requirements for health monitoring and management. This paper addresses the OPAD with its tool suite, and discusses what is considered a natural progression: a concept for migrating OPAD towards detection of high energy particles, including neutrons and gamma rays. The integration of these tools and capabilities will provide NASA with a systematic approach to monitor space vehicle internal and external environment.

Putting Integrated Systems Health Management Capabilities to Work: Development of an Advanced Caution and Warning System for Next-Generation Crewed Spacecraft Missions

NASA Technical Reports Server (NTRS)

Mccann, Robert S.; Spirkovska, Lilly; Smith, Irene

2013-01-01

Integrated System Health Management (ISHM) technologies have advanced to the point where they can provide significant automated assistance with real-time fault detection, diagnosis, guided troubleshooting, and failure consequence assessment. To exploit these capabilities in actual operational environments, however, ISHM information must be integrated into operational concepts and associated information displays in ways that enable human operators to process and understand the ISHM system information rapidly and effectively. In this paper, we explore these design issues in the context of an advanced caution and warning system (ACAWS) for next-generation crewed spacecraft missions. User interface concepts for depicting failure diagnoses, failure effects, redundancy loss, "what-if" failure analysis scenarios, and resolution of ambiguity groups are discussed and illustrated.

Correction of autofluorescence intensity for epithelial scattering by optical coherence tomography: a phantom study

NASA Astrophysics Data System (ADS)

Pahlevaninezhad, H.; Lee, A. M. D.; Hyun, C.; Lam, S.; MacAulay, C.; Lane, P. M.

2013-03-01

In this paper, we conduct a phantom study for modeling the autofluorescence (AF) properties of tissue. A combined optical coherence tomography (OCT) and AF imaging system is proposed to measure the strength of the AF signal in terms of the scattering layer thickness and concentration. The combined AF-OCT system is capable of estimating the AF loss due to scattering in the epithelium using the thickness and scattering concentration calculated from the co-registered OCT images. We define a correction factor to account for scattering losses in the epithelium and calculate a scatteringcorrected AF signal. We believe the scattering-corrected AF will reduce the diagnostic false-positives rate in the early detection of airway lesions due to confounding factors such as increased epithelial thickness and inflammations.

A compact 45 kV curve tracer with picoampere current measurement capability.

PubMed

Sullivan, W W; Mauch, D; Bullick, A; Hettler, C; Neuber, A; Dickens, J

2013-03-01

This paper discusses a compact high voltage curve tracer for high voltage semiconductor device characterization. The system sources up to 3 mA at up to 45 kV in dc conditions. It measures from 328 V to 60 kV with 15 V resolution and from 9.4 pA to 4 mA with 100 fA minimum resolution. Control software for the system is written in Microsoft Visual C# and features real-time measurement control and IV plotting, arc-protection and detection, an electrically isolated universal serial bus interface, and easy data exporting capabilities. The system has survived numerous catastrophic high voltage device-under-test arcing failures with no loss of measurement capability or system damage. Overall sweep times are typically under 2 min, and the curve tracer system was used to characterize the blocking performance of high voltage ceramic capacitors, high voltage silicon carbide photoconductive semiconductor switches, and high voltage coaxial cable.

Addition of various carbohydrates to beef burgers affects the formation of heterocyclic amines during frying.

PubMed

Persson, Elna; Sjöholm, Ingegerd; Nyman, Margareta; Skog, Kerstin

2004-12-15

The influence of the addition of carbohydrates with different physicochemical properties on weight loss and formation of heterocyclic amines (HAs) during the frying of beef burgers was examined. Furthermore, the capability of carbohydrates to bind HAs was tested. Beef burgers containing 1.5% NaCl and 0.3% tripolyphosphate (reference), with the addition of 1.5% carbohydrate, were fried for 5 min at 200 degrees C in a double-sided pan fryer. The beef burgers were analyzed for HAs with solid phase extraction and liquid chromatography/mass spectrometry. 2-Amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx), 2-amino-3,4,8-trimethylimidazo[4,5-f]quinoxaline (4,8-DiMeIQx), 2-amino-1-methyl-6-phenyl-imidazo[4,5-b]pyridine (PhIP), and 9H-pyrido[3,4-b]indole (Norharman) were detected in all of the beef burgers. The addition of carbohydrates affected both the weight loss and the formation of HAs during cooking. The formation of HAs could be correlated to depend on both the weight loss and the type of the added carbohydrate. Of the 11 different carbohydrates tested, raw potato starch was most capable of inhibiting the formation of HAs, while potato fiber gave the lowest weight loss and a comparably low amount of PhIP. Wheat bran and potato fiber were found to reversibly bind HAs. It is concluded that adding small amounts of certain carbohydrates may be a simple and effective way of reducing the amount of HAs and can easily be applied in households and commercial preparations of beef burgers.

Analytical SuperSTEM for extraterrestrial materials research

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

Bradley, J P; Dai, Z R

2009-09-08

Electron-beam studies of extraterrestrial materials with significantly improved spatial resolution, energy resolution and sensitivity are enabled using a 300 keV SuperSTEM scanning transmission electron microscope with a monochromator and two spherical aberration correctors. The improved technical capabilities enable analyses previously not possible. Mineral structures can be directly imaged and analyzed with single-atomic-column resolution, liquids and implanted gases can be detected, and UV-VIS optical properties can be measured. Detection limits for minor/trace elements in thin (<100 nm thick) specimens are improved such that quantitative measurements of some extend to the sub-500 ppm level. Electron energy-loss spectroscopy (EELS) can be carried outmore » with 0.10-0.20 eV energy resolution and atomic-scale spatial resolution such that variations in oxidation state from one atomic column to another can be detected. Petrographic mapping is extended down to the atomic scale using energy-dispersive x-ray spectroscopy (EDS) and energy-filtered transmission electron microscopy (EFTEM) imaging. Technical capabilities and examples of the applications of SuperSTEM to extraterrestrial materials are presented, including the UV spectral properties and organic carbon K-edge fine structure of carbonaceous matter in interplanetary dust particles (IDPs), x-ray elemental maps showing the nanometer-scale distribution of carbon within GEMS (glass with embedded metal and sulfides), the first detection and quantification of trace Ti in GEMS using EDS, and detection of molecular H{sub 2}O in vesicles and implanted H{sub 2} and He in irradiated mineral and glass grains.« less

Nondestructive Evaluation of Foam Insulation for the External Tank Return to Flight

NASA Technical Reports Server (NTRS)

Walker, James L.; Richter, Joel D.

2006-01-01

Nondestructive evaluation methods have been developed to identify defects in the foam thermal protection system (TPS) of the Space Shuttle External Tank (ET). Terahertz imaging and backscatter radiography have been brought from prototype lab systems to production hardened inspection tools in just a few years. These methods have been demonstrated to be capable of detecting void type defects under many inches of foam which, if not repaired, could lead to detrimental foam loss. The evolution of these methods from lab tools to implementation on the ET will be discussed.

[Application of MALDI-TOF-MS in gene testing for non-syndromic hearing loss].

PubMed

Zeng, Yun; Jiang, Dan; Feng, Da-fei; Jin, Dong-dong; Wu, Xiao-hui; Ding, Yan-li; Zou, Jing

2013-12-01

To investigate the feasibility of Matrix-Assisted Laser Desorption-Ionization Time of Flight Mass Spectrometry (MALDI-TOF-MS) , according to the genetic test of non-syndromic hearing loss (NSHL), and check using the direct sequencing. Peripheral blood was collected from 454 NSHL patients. DNA samples were extracted and 20 loci of the four common disease-causing genes were analysed by MALDI-TOF-MS, including GJB2 (35delG, 167delT, 176_191del16, 235delC, 299_300delAT ), GJB3 (538C→T, 547G→A), SLC26A4 (281C→T, 589G→A, IVS7-2A→G, 1174A→T, 1226G→A, 1229C→T, IVS15+5G→A, 1975G→C, 2027T→A, 2162C→T, 2168A→G), and mitochondrial 12S rRNA (1494C→T, 1555A→G). Direct sequencing was also used to analyse the aforementioned 20 loci in order to validate the accuracy of MALDI-TOF-MS. Among the 454 patients, 166 cases (36.56%) of disease-causing mutations were detected, which included 69 cases (21.15%) of GJB2 gene mutation, four cases (0.88%) of GJB3 gene mutation, 64 cases (14.10%) of SLC26A4 gene mutation, and three cases (0.66%) of mitochondrial 12S rRNA gene mutation. Moreover, the results obtained from direct sequencing and MALDI-TOF-MS were consistent, and the results showed that the two methods were consistent. The MALDI-TOF-MS detection method was designed based on the hearing loss-related mutation hotspots seen in the Chinese population, and it has a high detection rate for NSHL related mutations. In comparison to the conventional detection methods, MALDI-TOF-MS has the following advantages: more detection sites, greater coverage, accurate, high throughput and low cost. Therefore, this method is capable of satisfying the needs of clinical detection for hearing impairment and it is suitable for large-scale implementation.

A real time metabolomic profiling approach to detecting fish fraud using rapid evaporative ionisation mass spectrometry.

PubMed

Black, Connor; Chevallier, Olivier P; Haughey, Simon A; Balog, Julia; Stead, Sara; Pringle, Steven D; Riina, Maria V; Martucci, Francesca; Acutis, Pier L; Morris, Mike; Nikolopoulos, Dimitrios S; Takats, Zoltan; Elliott, Christopher T

2017-01-01

Fish fraud detection is mainly carried out using a genomic profiling approach requiring long and complex sample preparations and assay running times. Rapid evaporative ionisation mass spectrometry (REIMS) can circumvent these issues without sacrificing a loss in the quality of results. To demonstrate that REIMS can be used as a fast profiling technique capable of achieving accurate species identification without the need for any sample preparation. Additionally, we wanted to demonstrate that other aspects of fish fraud other than speciation are detectable using REIMS. 478 samples of five different white fish species were subjected to REIMS analysis using an electrosurgical knife. Each sample was cut 8-12 times with each one lasting 3-5 s and chemometric models were generated based on the mass range m/z 600-950 of each sample. The identification of 99 validation samples provided a 98.99% correct classification in which species identification was obtained near-instantaneously (≈ 2 s) unlike any other form of food fraud analysis. Significant time comparisons between REIMS and polymerase chain reaction (PCR) were observed when analysing 6 mislabelled samples demonstrating how REIMS can be used as a complimentary technique to detect fish fraud. Additionally, we have demonstrated that the catch method of fish products is capable of detection using REIMS, a concept never previously reported. REIMS has been proven to be an innovative technique to help aid the detection of fish fraud and has the potential to be utilised by fisheries to conduct their own quality control (QC) checks for fast accurate results.

Towards Routine Uncued Surveillance of Small Objects at and near Geostationary Orbit with Small Telescopes

NASA Astrophysics Data System (ADS)

Zimmer, P.; McGraw, J. T.; Ackermann, M. R.

There is considerable interest in the capability to discover and monitor small objects (d 20cm) in geosynchronous (GEO) and near-GEO orbital regimes using small, ground-based optical telescopes (D < 0.5m). The threat of such objects is clear. Small telescopes have an unrivaled cost advantage and, under ideal lighting and sky conditions, have the capability of detecting faint objects. This combination of conditions, however, is relatively rare, making routine and persistent surveillance more challenging. In a truly geostationary orbit, a small object is easy to detect because its apparent rate of motion is nearly zero for a ground-based observer, and signal accumulation occurs as it would for more traditional sidereal-tracked astronomical observations. In this regime, though, small objects are not expected to be in controlled or predictable orbits, thus a range of inclinations and eccentricities is possible. This results in a range of apparent angular rates and directions that must be surveilled. This firmly establishes this task as uncued or blind surveillance. Detections in this case are subject to what is commonly called “trailing loss,” where the signal from the object does not accumulate in a fixed detection element, resulting in far lower sensitivity than for a similar object optimally tracked. We review some of the limits of detecting these objects under less than ideal observing conditions, subject further to the current limitations based on technological and operational realities. We demonstrate progress towards this goal using telescopes much smaller than normally considered viable for this task using novel detection and analysis techniques.

Cognitive LF-Ant: a novel protocol for healthcare wireless sensor networks.

PubMed

Sousa, Marcelo; Lopes, Waslon; Madeiro, Francisco; Alencar, Marcelo

2012-01-01

In this paper, the authors present the Cognitive LF-Ant protocol for emergency reporting in healthcare wireless sensor networks. The protocol is inspired by the natural behaviour of ants and a cognitive component provides the capabilities to dynamically allocate resources, in accordance with the emergency degree of each patient. The intra-cluster emergency reporting is inspired by the different capabilities of leg-manipulated ants. The inter-cluster reporting is aided by the cooperative modulation diversity with spectrum sensing, which can detect new emergency reporting requests and forward them. Simulations results show the decrease of average delay time as the probability of opportunistic access increases, which privileges the emergency reporting related to the patients with higher priority of resources' usage. Furthermore, the packet loss rate is decreased by the use of cooperative modulation diversity with spectrum sensing.

Cognitive LF-Ant: A Novel Protocol for Healthcare Wireless Sensor Networks

PubMed Central

Sousa, Marcelo; Lopes, Waslon; Madeiro, Francisco; Alencar, Marcelo

2012-01-01

In this paper, the authors present the Cognitive LF-Ant protocol for emergency reporting in healthcare wireless sensor networks. The protocol is inspired by the natural behaviour of ants and a cognitive component provides the capabilities to dynamically allocate resources, in accordance with the emergency degree of each patient. The intra-cluster emergency reporting is inspired by the different capabilities of leg-manipulated ants. The inter-cluster reporting is aided by the cooperative modulation diversity with spectrum sensing, which can detect new emergency reporting requests and forward them. Simulations results show the decrease of average delay time as the probability of opportunistic access increases, which privileges the emergency reporting related to the patients with higher priority of resources' usage. Furthermore, the packet loss rate is decreased by the use of cooperative modulation diversity with spectrum sensing. PMID:23112610

Relative receiver autonomous integrity monitoring for future GNSS-based aircraft navigation

NASA Astrophysics Data System (ADS)

Gratton, Livio Rafael

The Global Positioning System (GPS) has enabled reliable, safe, and practical aircraft positioning for en-route and non-precision phases of flight for more than a decade. Intense research is currently devoted to extending the use of Global Navigation Satellite Systems (GNSS), including GPS, to precision approach and landing operations. In this context, this work is focused on the development, analysis, and verification of the concept of Relative Receiver Autonomous Integrity Monitoring (RRAIM) and its potential applications to precision approach navigation. RRAIM fault detection algorithms are developed, and associated mathematical bounds on position error are derived. These are investigated as possible solutions to some current key challenges in precision approach navigation, discussed below. Augmentation systems serving continent-size areas (like the Wide Area Augmentation System or WAAS) allow certain precision approach operations within the covered region. More and better satellites, with dual frequency capabilities, are expected to be in orbit in the mid-term future, which will potentially allow WAAS-like capabilities worldwide with a sparse ground station network. Two main challenges in achieving this goal are (1) ensuring that navigation fault detection functions are fast enough to alert worldwide users of hazardously misleading information, and (2) minimizing situations in which navigation is unavailable because the user's local satellite geometry is insufficient for safe position estimation. Local augmentation systems (implemented at individual airports, like the Local Area Augmentation System or LAAS) have the potential to allow precision approach and landing operations by providing precise corrections to user-satellite range measurements. An exception to these capabilities arises during ionospheric storms (caused by solar activity), when hazardous situations can exist with residual range errors several orders of magnitudes higher than nominal. Until dual frequency civil GPS signals are available, the ability to provide integrity during ionospheric storms, without excessive loss of availability is a major challenge. For all users, with or without augmentation, some situations cause short duration losses of satellites in view. Two examples are aircraft banking during turns and ionospheric scintillation. The loss of range signals can translate into gaps in good satellite geometry, and the resulting challenge is to ensure navigation continuity by bridging these gaps, while simultaneously maintaining high integrity. It is shown that the RRAIM methods developed in this research can be applied to mitigate each of these obstacles to safe and reliable precision aircraft navigation.

Detection of exudates in fundus images using a Markovian segmentation model.

PubMed

Harangi, Balazs; Hajdu, Andras

2014-01-01

Diabetic retinopathy (DR) is one of the most common causing of vision loss in developed countries. In early stage of DR, some signs like exudates appear in the retinal images. An automatic screening system must be capable to detect these signs properly so that the treatment of the patients may begin in time. The appearance of exudates shows a rich variety regarding their shape and size making automatic detection more challenging. We propose a way for the automatic segmentation of exudates consisting of a candidate extraction step followed by exact contour detection and region-wise classification. More specifically, we extract possible exudate candidates using grayscale morphology and their proper shape is determined by a Markovian segmentation model considering edge information. Finally, we label the candidates as true or false ones by an optimally adjusted SVM classifier. For testing purposes, we considered the publicly available database DiaretDB1, where the proposed method outperformed several state-of-the-art exudate detectors.

Remote detection of buried land-mines and IEDs using LWIR polarimetric imaging.

PubMed

Gurton, Kristan P; Felton, Melvin

2012-09-24

We report results of an ongoing study designed to assess the ability for enhanced detection of recently buried land-mines and/or improvised explosive devices (IED) devices using passive long-wave infrared (LWIR) polarimetric imaging. Polarimetric results are presented for a series of field tests conducted at various locations and soil types. Well-calibrated Stokes images, S0, S1, S2, and the degree-of-linear-polarization (DoLP) are recorded for different line-of-sight (LOS) slant paths at varying distances. Results span a three-year time period in which three different LWIR polarimetric camera systems are used. All three polarimetric imaging platforms used a spinning-achromatic-retarder (SAR) design capable of achieving high polarimetric frame rates and good radiometric throughput without the loss of spatial resolution inherent in other optical designs. Receiver-operating-characteristic (ROC) analysis and a standardized contrast parameter are used to compare detectability between conventional LWIR thermal and polarimetric imagery. Results suggest improved detectability, regardless of geographic location or soil type.

Late diagenetic indicators of buried oil and gas. 2: Direct detection experiment at Cement and Garza fields, Oklahoma and Texas, using enhanced LANDSAT 1 and 2 images

NASA Technical Reports Server (NTRS)

Donovan, T. J.; Termain, P. A.; Henry, M. E. (Principal Investigator)

1979-01-01

The author has identified the following significant results. The Cement oil field, Oklahoma, was a test site for an experiment designed to evaluate LANDSAT's capability to detect an alteration zone in surface rocks caused by hydrocarbon microseepage. Loss of iron and impregnation of sandstone by carbonate cements and replacement of gypsum by calcite were the major alteration phenomena at Cement. The bedrock alterations were partially masked by unaltered overlying beds, thick soils, and dense natural and cultivated vegetation. Interpreters, biased by detailed ground truth, were able to map the alteration zone subjectively using a magnified, filtered, and sinusoidally stretched LANDSAT composite image; other interpreters, unbiased by ground truth data, could not duplicate that interpretation.

Counting Particles Emitted by Stratospheric Aircraft and Measuring Size of Particles Emitted by Stratospheric Aircraft

NASA Technical Reports Server (NTRS)

Wilson, James Charles

1994-01-01

There were two principal objectives of the cooperative agreement between NASA and the University of Denver. The first goal was to modify the design of the ER-2 condensation nuclei counter (CNC) so that the effective lower detection limit would be improved at high altitudes. This improvement was sought because, in the instrument used prior to 1993, diffusion losses prevented the smallest detectable particles from reaching the detection volume of the instrument during operation at low pressure. Therefore, in spite of the sensor's ability to detect particles as small as 0.008 microns in diameter, many of these particles were lost in transport to the sensing region and were not counted. Most of the particles emitted by aircraft are smaller than 0.1 micron in diameter. At the start date of this work, May 1990, continuous sizing techniques available on the ER-2 were only capable of detecting particles larger than 0.17 micron. Thus, the second objective of this work was to evaluate candidate sizing techniques in an effort to gain additional information concerning the size of particles emitted by aircraft.

Detection of weapons of mass destruction

NASA Astrophysics Data System (ADS)

Bjorkholm, Paul J.

2003-07-01

High Energy X-ray cargo screening is a mature technology that has proven its value in the detection of contraband material hidden within cargo including fully loaded sea containers. To date high energy screening has been largely applied to manifest verification and to drug detection. However, the dramatic change in world terrorism has altered the application. Now it is essential that weapons of mass destruction (WMD"s) be interdicted with incredibly high accuracy. The implication of a missed detection has gone from loss of revenue or the lowering of the street price of drugs to potentially stopping, at least for some significant time, most world commerce. Screening containers with high energy x-rays (~250+ mm of steel penetration) is capable of detecting all nuclear threats at a fraction of the strategically important mass. The screening operation can be automated so that no human decisions are required with very low false alarms. Finally, the goal of 100% inspection of cargo inbound to the United States from the twenty largest international ports is an achievable goal with hardware costs in the area of that already spent on airport security.

78 FR 39571 - Airworthiness Directives; The Boeing Company Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-02

... 2800, Aircraft Fuel System. (e) Unsafe Condition This AD was prompted by reports of two in-service... system, followed by loss of fuel system suction feed capability on one engine, and in-flight shutdown of... and correct loss of the engine fuel suction feed capability of the fuel system, which, in the event of...

Coupling photochemical reaction detection based on singlet oxygen sensitization to capillary electrochromatography

PubMed

Dickson; Odom; Ducheneaux; Murray; Milofsky

2000-07-15

Despite the impressive separation efficiency afforded by capillary electrochromatography (CEC), the detection of UV-absorbing compounds following separation in capillary dimensions remains limited by the short path length (5-75 microm) through the column. Moreover, analytes that are poor chromophores present an additional challenge with respect to sensitive detection in CEC. This paper illustrates a new photochemical reaction detection scheme for CEC that takes advantage of the catalytic nature of type II photooxidation reactions. The sensitive detection scheme is selective toward molecules capable of photosensitizing the formation of singlet molecular oxygen (1O2). Following separation by CEC, UV-absorbing analytes promote groundstate 3O2 to an excited state (1O2) which reacts rapidly with tert-butyl-3,4,5-trimethylpyrrolecarboxylate, which is added to the running buffer. Detection is based on the loss of pyrrole. The reaction is catalytic in nature since one analyte molecule may absorb light many times, producing large amounts of 1O2. The detection limit for 9-acetylanthracene, following separation by CEC, is approximately 6 x 10(-9) M (S/N = 3). Optimization of the factors effecting the S/N for four model compounds is discussed.

Effects of loss on the phase sensitivity with parity detection in an SU(1,1) interferometer

NASA Astrophysics Data System (ADS)

Li, Dong; Yuan, Chun-Hua; Yao, Yao; Jiang, Wei; Li, Mo; Zhang, Weiping

2018-05-01

We theoretically study the effects of loss on the phase sensitivity of an SU(1,1) interferometer with parity detection with various input states. We show that although the sensitivity of phase estimation decreases in the presence of loss, it can still beat the shot-noise limit with small loss. To examine the performance of parity detection, the comparison is performed among homodyne detection, intensity detection, and parity detection. Compared with homodyne detection and intensity detection, parity detection has a slight better optimal phase sensitivity in the absence of loss, but has a worse optimal phase sensitivity with a significant amount of loss with one-coherent state or coherent $\\otimes$ squeezed state input.

Photothermal tomography for the functional and structural evaluation, and early mineral loss monitoring in bones.

PubMed

Kaiplavil, Sreekumar; Mandelis, Andreas; Wang, Xueding; Feng, Ting

2014-08-01

Salient features of a new non-ionizing bone diagnostics technique, truncated-correlation photothermal coherence tomography (TC-PCT), exhibiting optical-grade contrast and capable of resolving the trabecular network in three dimensions through the cortical region with and without a soft-tissue overlayer are presented. The absolute nature and early demineralization-detection capability of a marker called thermal wave occupation index, estimated using the proposed modality, have been established. Selective imaging of regions of a specific mineral density range has been demonstrated in a mouse femur. The method is maximum-permissible-exposure compatible. In a matrix of bone and soft-tissue a depth range of ~3.8 mm has been achieved, which can be increased through instrumental and modulation waveform optimization. Furthermore, photoacoustic microscopy, a comparable modality with TC-PCT, has been used to resolve the trabecular structure and for comparison with the photothermal tomography.

Photothermal tomography for the functional and structural evaluation, and early mineral loss monitoring in bones

PubMed Central

Kaiplavil, Sreekumar; Mandelis, Andreas; Wang, Xueding; Feng, Ting

2014-01-01

Salient features of a new non-ionizing bone diagnostics technique, truncated-correlation photothermal coherence tomography (TC-PCT), exhibiting optical-grade contrast and capable of resolving the trabecular network in three dimensions through the cortical region with and without a soft-tissue overlayer are presented. The absolute nature and early demineralization-detection capability of a marker called thermal wave occupation index, estimated using the proposed modality, have been established. Selective imaging of regions of a specific mineral density range has been demonstrated in a mouse femur. The method is maximum-permissible-exposure compatible. In a matrix of bone and soft-tissue a depth range of ~3.8 mm has been achieved, which can be increased through instrumental and modulation waveform optimization. Furthermore, photoacoustic microscopy, a comparable modality with TC-PCT, has been used to resolve the trabecular structure and for comparison with the photothermal tomography. PMID:25136480

Aviation Trends Related to Atmospheric Environment Safety Technologies Project Technical Challenges

NASA Technical Reports Server (NTRS)

Reveley, Mary S.; Withrow, Colleen A.; Barr, Lawrence C.; Evans, Joni K.; Leone, Karen M.; Jones, Sharon M.

2014-01-01

Current and future aviation safety trends related to the National Aeronautics and Space Administration's Atmospheric Environment Safety Technologies Project's three technical challenges (engine icing characterization and simulation capability; airframe icing simulation and engineering tool capability; and atmospheric hazard sensing and mitigation technology capability) were assessed by examining the National Transportation Safety Board (NTSB) accident database (1989 to 2008), incidents from the Federal Aviation Administration (FAA) accident/incident database (1989 to 2006), and literature from various industry and government sources. The accident and incident data were examined for events involving fixed-wing airplanes operating under Federal Aviation Regulation (FAR) Parts 121, 135, and 91 for atmospheric conditions related to airframe icing, ice-crystal engine icing, turbulence, clear air turbulence, wake vortex, lightning, and low visibility (fog, low ceiling, clouds, precipitation, and low lighting). Five future aviation safety risk areas associated with the three AEST technical challenges were identified after an exhaustive survey of a variety of sources and include: approach and landing accident reduction, icing/ice detection, loss of control in flight, super density operations, and runway safety.

Detection of Pancreatic Cancer-Induced Cachexia Using a Fluorescent Myoblast Reporter System and Analysis of Metabolite Abundance.

PubMed

Winnard, Paul T; Bharti, Santosh K; Penet, Marie-France; Marik, Radharani; Mironchik, Yelena; Wildes, Flonne; Maitra, Anirban; Bhujwalla, Zaver M

2016-03-15

The dire effects of cancer-induced cachexia undermine treatment and contribute to decreased survival rates. Therapeutic options for this syndrome are limited, and therefore efforts to identify signs of precachexia in cancer patients are necessary for early intervention. The applications of molecular and functional imaging that would enable a whole-body "holistic" approach to this problem may lead to new insights and advances for diagnosis and treatment of this syndrome. Here we have developed a myoblast optical reporter system with the purpose of identifying early cachectic events. We generated a myoblast cell line expressing a dual tdTomato:GFP construct that was grafted onto the muscle of mice-bearing human pancreatic cancer xenografts to provide noninvasive live imaging of events associated with cancer-induced cachexia (i.e., weight loss). Real-time optical imaging detected a strong tdTomato fluorescent signal from skeletal muscle grafts in mice with weight losses of only 1.2% to 2.7% and tumor burdens of only approximately 79 to 170 mm(3). Weight loss in cachectic animals was also associated with a depletion of lipid, cholesterol, valine, and alanine levels, which may provide informative biomarkers of cachexia. Taken together, our findings demonstrate the utility of a reporter system that is capable of tracking tumor-induced weight loss, an early marker of cachexia. Future studies incorporating resected tissue from human pancreatic ductal adenocarcinoma into a reporter-carrying mouse may be able to provide a risk assessment of cachexia, with possible implications for therapeutic development. ©2015 American Association for Cancer Research.

An improved, rapid competitive ELISA using a novel conserved 3B epitope for the detection of serum antibodies to foot-and-mouth disease virus.

PubMed

Chung, Chungwon J; Clavijo, Alfonso; Bounpheng, Mangkey A; Uddowla, Sabena; Sayed, Abu; Dancho, Brooke; Olesen, Ian C; Pacheco, Juan; Kamicker, Barbara J; Brake, David A; Bandaranayaka-Mudiyanselage, Carey L; Lee, Stephen S; Rai, Devendra K; Rieder, Elizabeth

2018-06-01

The highly contagious foot-and-mouth disease virus (FMDV) afflicts cloven-hoofed animals, resulting in significant costs because of loss of trade and recovery from disease. We developed a sensitive, specific, and rapid competitive ELISA (cELISA) to detect serum antibodies to FMDV. The cELISA utilized a monoclonal blocking antibody specific for a highly conserved FMDV nonstructural 3B epitope, a recombinant mutant FMDV 3ABC coating protein, and optimized format variables including serum incubation for 90 min at 20-25°C. Samples from 16 animals experimentally infected with one FMDV serotype (A, O, Asia, or SAT-1) demonstrated early detection capacity beginning 7 d post-inoculation. All samples from 55 vesicular stomatitis virus antibody-positive cattle and 44 samples from cloven-hoofed animals affected by non-FMD vesicular diseases were negative in the cELISA, demonstrating 100% analytical specificity. The diagnostic sensitivity was 100% against sera from 128 cattle infected with isolates of all FMDV serotypes, emphasizing serotype-agnostic results. Diagnostic specificities of U.S. cattle ( n = 1135) and swine ( n = 207) sera were 99.4% and 100%, respectively. High repeatability and reproducibility were demonstrated with 3.1% coefficient of variation in percent inhibition data and 100% agreement using 2 kit lots and 400 negative control serum samples, with no difference between bench and biosafety cabinet operation. Negative results from vaccinated, uninfected cattle, pig, and sheep sera confirmed the DIVA (differentiate infected from vaccinated animals) capability. This rapid (<3 h), select agent-free assay with high sensitivity and specificity, DIVA capability, and room temperature processing capability will serve as a useful tool in FMDV surveillance, emergency preparedness, response, and outbreak recovery programs.

Photon counting detector for the personal radiography inspection system "SIBSCAN"

NASA Astrophysics Data System (ADS)

Babichev, E. A.; Baru, S. E.; Grigoriev, D. N.; Leonov, V. V.; Oleynikov, V. P.; Porosev, V. V.; Savinov, G. A.

2017-02-01

X-ray detectors operating in the energy integrating mode are successfully used in many different applications. Nevertheless the direct photon counting detectors, having the superior parameters in comparison with the integrating ones, are rarely used yet. One of the reasons for this is the low value of the electrical signal generated by a detected photon. Silicon photomultiplier (SiPM) based scintillation counters have a high detection efficiency, high electronic gain and compact dimensions. This makes them a very attractive candidate to replace routinely used detectors in many fields. More than 10 years ago the digital scanning radiography system based on multistrip ionization chamber (MIC) was suggested at Budker Institute of Nuclear Physics. The detector demonstrates excellent radiation resistance and parameter stability after 5 year operations and an imaging of up to 1000 persons per day. Currently, the installations operate at several Russian airports and at subway stations in some cities. At the present time we design a new detector operating in the photon counting mode, having superior parameters than the gas one, based on scintillator - SiPM assemblies. This detector has close to zero noise, higher quantum efficiency and a count rate capability of more than 5 MHz per channel (20% losses), which leads to better image quality and improved detection capability. The suggested detector technology could be expanded to medical applications.

Effect of the preform fabrication process on the properties of all-silica optical fibres

NASA Astrophysics Data System (ADS)

Grishchenko, A. B.

2017-12-01

In this paper, we present a detailed comparison of technical capabilities of processes for the fabrication of all-silica optical fibre preforms with the use of an atmospheric pressure radio frequency plasma (POVD process) and low-pressure microwave plasma (PCVD process) and analyse the origin of the difference in optical properties between fibres produced by these methods. It is shown that the higher temperature of the core material and the higher oxygen partial pressure in preform fabrication by the POVD process lead to an increase in optical losses in the visible and UV spectral regions in the silica fibres with low hydroxyl (OH) content and a decrease in the solarisation resistance of the fibres with high OH content, i.e. to a more rapid increase in background losses in response to UV irradiation. No such drawbacks are detected in the case of the growth of reflective layers by the PCVD process.

Visual Inspection of Water Leakage from Ground Penetrating Radar Radargram

NASA Astrophysics Data System (ADS)

Halimshah, N. N.; Yusup, A.; Mat Amin, Z.; Ghazalli, M. D.

2015-10-01

Water loss in town and suburban is currently a significant issue which reflect the performance of water supply management in Malaysia. Consequently, water supply distribution system has to be maintained in order to prevent shortage of water supply in an area. Various techniques for detecting a mains water leaks are available but mostly are time-consuming, disruptive and expensive. In this paper, the potential of Ground Penetrating Radar (GPR) as a non-destructive method to correctly and efficiently detect mains water leaks has been examined. Several experiments were designed and conducted to prove that GPR can be used as tool for water leakage detection. These include instrument validation test and soil compaction test to clarify the maximum dry density (MDD) of soil and simulation studies on water leakage at a test bed consisting of PVC pipe burying in sand to a depth of 40 cm. Data from GPR detection are processed using the Reflex 2D software. Identification of water leakage was visually inspected from the anomalies in the radargram based on GPR reflection coefficients. The results have ascertained the capability and effectiveness of the GPR in detecting water leakage which could help avoiding difficulties with other leak detection methods.

'I didn't see that coming': simulated visual fields and driving hazard perception test performance.

PubMed

Glen, Fiona C; Smith, Nicholas D; Jones, Lee; Crabb, David P

2016-09-01

Evidence is limited regarding specific types of visual field loss associated with unsafe driving. We use novel gaze-contingent software to examine the effect of simulated visual field loss on computer-based driving hazard detection with the specific aim of testing the impact of scotomata located to the right and left of fixation. The 'hazard perception test' is a component of the UK driving licence examination, which measures speed of detecting 15 different hazards in a series of real-life driving films. We have developed a novel eye-tracking and computer set up capable of generating a realistic gaze-contingent scotoma simulation (GazeSS) overlaid on film content. Thirty drivers with healthy vision completed three versions of the hazard perception test in a repeated measures experiment. In two versions, GazeSS simulated a scotoma in the binocular field of view to the left or right of fixation. A third version was unmodified to establish baseline performance. Participants' mean baseline hazard perception test score was 51 ± 7 (out of 75). This reduced to 46 ± 9 and 46 ± 11 when completing the task with a binocular visual field defect located to the left and right of fixation, respectively. While the main effect of simulated visual field loss on performance was statistically significant (p = 0.007), there were no average differences in the experimental conditions where a scotoma was located in the binocular visual field to the right or left of fixation. Simulated visual field loss impairs driving hazard detection on a computer-based test. There was no statistically significant difference in average performance when the simulated scotoma was located to the right or left of fixation of the binocular visual field, but certain types of hazard caused more difficulties than others. © 2016 Optometry Australia.

Phase-detected Brillouin optical correlation-domain reflectometry

NASA Astrophysics Data System (ADS)

Mizuno, Yosuke; Hayashi, Neisei; Fukuda, Hideyuki; Nakamura, Kentaro

2018-05-01

Optical fiber sensing techniques based on Brillouin scattering have been extensively studied for structural health monitoring owing to their capability of distributed strain and temperature measurement. Although a higher signal-to-noise ratio (leading to high spatial resolution and high-speed measurement) is generally obtained for two-end-access systems, they reduce the degree of freedom in embedding the sensors into structures, and render the measurement no longer feasible when extremely high loss or breakage occurs at a point of the sensing fiber. To overcome these drawbacks, a one-end-access sensing technique called Brillouin optical correlation-domain reflectometry (BOCDR) has been developed. BOCDR has a high spatial resolution and cost efficiency, but its conventional configuration suffered from relatively low-speed operation. In this paper, we review the recently developed high-speed configurations of BOCDR, including phase-detected BOCDR, with which we demonstrate real-time distributed measurement by tracking a propagating mechanical wave. We also demonstrate breakage detection with a wide strain dynamic range.

Phase-detected Brillouin optical correlation-domain reflectometry

NASA Astrophysics Data System (ADS)

Mizuno, Yosuke; Hayashi, Neisei; Fukuda, Hideyuki; Nakamura, Kentaro

2018-06-01

Optical fiber sensing techniques based on Brillouin scattering have been extensively studied for structural health monitoring owing to their capability of distributed strain and temperature measurement. Although a higher signal-to-noise ratio (leading to high spatial resolution and high-speed measurement) is generally obtained for two-end-access systems, they reduce the degree of freedom in embedding the sensors into structures, and render the measurement no longer feasible when extremely high loss or breakage occurs at a point of the sensing fiber. To overcome these drawbacks, a one-end-access sensing technique called Brillouin optical correlation-domain reflectometry (BOCDR) has been developed. BOCDR has a high spatial resolution and cost efficiency, but its conventional configuration suffered from relatively low-speed operation. In this paper, we review the recently developed high-speed configurations of BOCDR, including phase-detected BOCDR, with which we demonstrate real-time distributed measurement by tracking a propagating mechanical wave. We also demonstrate breakage detection with a wide strain dynamic range.

Aerial ultrasonic micro Doppler sonar detection range in outdoor environments.

PubMed

Bradley, Marshall; Sabatier, James M

2012-03-01

Current research demonstrates that micro Doppler sonar has the capability to uniquely identify the presence of a moving human, making it an attractive component in surveillance systems for border security applications. Primary environmental factors that limit sonar performance are two-way spreading losses, ultrasonic absorption, and backscattered energy from the ground that appears at zero Doppler shift in the sonar signal processor. Spectral leakage from the backscatter component has a significant effect on sonar performance for slow moving targets. Sonar performance is shown to rapidly decay as the sensor is moved closer to the ground due to increasing surface backscatter levels. © 2012 Acoustical Society of America

Photonics

NASA Astrophysics Data System (ADS)

Roh, Won B.

Photonic technologies-based computational systems are projected to be able to offer order-of-magnitude improvements in processing speed, due to their intrinsic architectural parallelism and ultrahigh switching speeds; these architectures also minimize connectors, thereby enhancing reliability, and preclude EMP vulnerability. The use of optoelectronic ICs would also extend weapons capabilities in such areas as automated target recognition, systems-state monitoring, and detection avoidance. Fiber-optics technologies have an information-carrying capacity fully five orders of magnitude greater than copper-wire-based systems; energy loss in transmission is two orders of magnitude lower, and error rates one order of magnitude lower. Attention is being given to ZrF glasses for optical fibers with unprecedentedly low scattering levels.

Robust fault detection of wind energy conversion systems based on dynamic neural networks.

PubMed

Talebi, Nasser; Sadrnia, Mohammad Ali; Darabi, Ahmad

2014-01-01

Occurrence of faults in wind energy conversion systems (WECSs) is inevitable. In order to detect the occurred faults at the appropriate time, avoid heavy economic losses, ensure safe system operation, prevent damage to adjacent relevant systems, and facilitate timely repair of failed components; a fault detection system (FDS) is required. Recurrent neural networks (RNNs) have gained a noticeable position in FDSs and they have been widely used for modeling of complex dynamical systems. One method for designing an FDS is to prepare a dynamic neural model emulating the normal system behavior. By comparing the outputs of the real system and neural model, incidence of the faults can be identified. In this paper, by utilizing a comprehensive dynamic model which contains both mechanical and electrical components of the WECS, an FDS is suggested using dynamic RNNs. The presented FDS detects faults of the generator's angular velocity sensor, pitch angle sensors, and pitch actuators. Robustness of the FDS is achieved by employing an adaptive threshold. Simulation results show that the proposed scheme is capable to detect the faults shortly and it has very low false and missed alarms rate.

Robust Fault Detection of Wind Energy Conversion Systems Based on Dynamic Neural Networks

PubMed Central

Talebi, Nasser; Sadrnia, Mohammad Ali; Darabi, Ahmad

2014-01-01

Occurrence of faults in wind energy conversion systems (WECSs) is inevitable. In order to detect the occurred faults at the appropriate time, avoid heavy economic losses, ensure safe system operation, prevent damage to adjacent relevant systems, and facilitate timely repair of failed components; a fault detection system (FDS) is required. Recurrent neural networks (RNNs) have gained a noticeable position in FDSs and they have been widely used for modeling of complex dynamical systems. One method for designing an FDS is to prepare a dynamic neural model emulating the normal system behavior. By comparing the outputs of the real system and neural model, incidence of the faults can be identified. In this paper, by utilizing a comprehensive dynamic model which contains both mechanical and electrical components of the WECS, an FDS is suggested using dynamic RNNs. The presented FDS detects faults of the generator's angular velocity sensor, pitch angle sensors, and pitch actuators. Robustness of the FDS is achieved by employing an adaptive threshold. Simulation results show that the proposed scheme is capable to detect the faults shortly and it has very low false and missed alarms rate. PMID:24744774

Protection of Melanized Cryptococcus neoformans from Lethal Dose Gamma Irradiation Involves Changes in Melanin's Chemical Structure and Paramagnetism

PubMed Central

Khajo, Abdelahad; Bryan, Ruth A.; Friedman, Matthew; Burger, Richard M.; Levitsky, Yan; Casadevall, Arturo; Magliozzo, Richard S.; Dadachova, Ekaterina

2011-01-01

Certain fungi thrive in highly radioactive environments including the defunct Chernobyl nuclear reactor. Cryptococcus neoformans (C. neoformans), which uses L-3,4-dihydroxyphenylalanine (L-DOPA) to produce melanin, was used here to investigate how gamma radiation under aqueous aerobic conditions affects the properties of melanin, with the aim of gaining insight into its radioprotective role. Exposure of melanized fungal cell in aqueous suspensions to doses of γ-radiation capable of killing 50 to 80% of the cells did not lead to a detectable loss of melanin integrity according to EPR spectra of melanin radicals. Moreover, upon UV-visible (Xe-lamp) illumination of melanized cells, the increase in radical population was unchanged after γ-irradiation. Gamma-irradiation of frozen cell suspensions and storage of samples for several days at 77 K however, produced melanin modification noted by a reduced radical population and reduced photoresponse. More direct evidence for structural modification of melanin came from the detection of soluble products with absorbance maxima near 260 nm in supernatants collected after γ-irradiation of cells and cell-free melanin. These products, which include thiobarbituric acid (TBA)-reactive aldehydes, were also generated by Fenton reagent treatment of cells and cell-free melanin. In an assay of melanin integrity based on the metal (Bi+3) binding capacity of cells, no detectable loss in binding was detected after γ-irradiation. Our results show that melanin in C. neoformans cells is susceptible to some damage by hydroxyl radical formed in lethal radioactive aqueous environments and serves a protective role in melanized fungi that involves sacrificial breakdown. PMID:21966422

A hetero-core fiber optic smart mat sensor for discrimination between a moving human and object on temporal loss peaks

NASA Astrophysics Data System (ADS)

Hosoki, Ai; Nishiyama, Michiko; Choi, Yongwoon; Watanabe, Kazuhiro

2011-05-01

In this paper, we propose discrimination method between a moving human and object by means of a hetero-core fiber smart mat sensor which induces the optical loss change in time. In addition to several advantages such as flexibility, thin size and resistance to electro-magnetic interference for a fiber optic sensor, a hetero-core fiber optic sensor is sensitive to bending action of the sensor portion and independent of temperature fluctuations. Therefore, the hetero-core fiber thin mat sensor can have a fewer sensing portions than the conventional floor pressure sensors, furthermore, can detect the wide area covering the length of strides. The experimental results for human walking tests showed that the mat sensors were reproducibly working in real-time under limiting locations the foot passed in the mat sensor. Focusing on the temporal peak numbers in the optical loss, human walking and wheeled platform moving action induced the peak numbers in the range of 1 - 3 and 5 - 7, respectively, for the 10 persons including 9 male and 1 female. As a result, we conclude that the hetero-core fiber mat sensor is capable of discriminating between the moving human and object such as a wheeled platform focusing on the peak numbers in the temporal optical loss.

Calibration of the low-energy channel Thomson parabola of the LMJ-PETAL diagnostic SEPAGE with protons and carbon ions.

PubMed

Ducret, J-E; Batani, D; Boutoux, G; Chancé, A; Gastineau, B; Guillard, J-C; Harrault, F; Jakubowska, K; Lantuejoul-Thfoin, I; Leboeuf, D; Loiseau, D; Lotode, A; Pès, C; Rabhi, N; Saïd, A; Semsoum, A; Serani, L; Thomas, B; Toussaint, J-C; Vauzour, B

2018-02-01

The SEPAGE diagnostic will detect charged particles (electrons, protons, and ions) accelerated in the interaction of the PETAL (PETawatt Aquitaine Laser) laser with its targets on the LMJ (Laser MegaJoule)-PETAL laser facility. SEPAGE will be equipped with a proton-radiography front detector and two Thomson parabolas (TP), corresponding to different ranges of the particle energy spectra: Above 0.1 MeV for electrons and protons in the low-energy channel, with a separation capability between protons and 12 C 6+ up to 20 MeV proton energy and above 8 MeV for the high-energy channel, with a separation capability between protons and 12 C 6+ up to 200 MeV proton kinetic energy. This paper presents the calibration of the SEPAGE's low-energy channel TP at the Tandem facility of Orsay (France) with proton beams between 3 and 22 MeV and carbon-ion beams from 5.8 to 84 MeV. The magnetic and electric fields' integrals were determined with an accuracy of 10 -3 by combining the deflections measured at different energies with different target thicknesses and materials, providing different in-target energy losses of the beam particles and hence different detected energies for given beam energies.

Calibration of the low-energy channel Thomson parabola of the LMJ-PETAL diagnostic SEPAGE with protons and carbon ions

NASA Astrophysics Data System (ADS)

Ducret, J.-E.; Batani, D.; Boutoux, G.; Chancé, A.; Gastineau, B.; Guillard, J.-C.; Harrault, F.; Jakubowska, K.; Lantuejoul-Thfoin, I.; Leboeuf, D.; Loiseau, D.; Lotode, A.; Pès, C.; Rabhi, N.; Saïd, A.; Semsoum, A.; Serani, L.; Thomas, B.; Toussaint, J.-C.; Vauzour, B.

2018-02-01

The SEPAGE diagnostic will detect charged particles (electrons, protons, and ions) accelerated in the interaction of the PETAL (PETawatt Aquitaine Laser) laser with its targets on the LMJ (Laser MegaJoule)-PETAL laser facility. SEPAGE will be equipped with a proton-radiography front detector and two Thomson parabolas (TP), corresponding to different ranges of the particle energy spectra: Above 0.1 MeV for electrons and protons in the low-energy channel, with a separation capability between protons and 12C6+ up to 20 MeV proton energy and above 8 MeV for the high-energy channel, with a separation capability between protons and 12C6+ up to 200 MeV proton kinetic energy. This paper presents the calibration of the SEPAGE's low-energy channel TP at the Tandem facility of Orsay (France) with proton beams between 3 and 22 MeV and carbon-ion beams from 5.8 to 84 MeV. The magnetic and electric fields' integrals were determined with an accuracy of 10-3 by combining the deflections measured at different energies with different target thicknesses and materials, providing different in-target energy losses of the beam particles and hence different detected energies for given beam energies.

Potential to Detect Hydrogen Concentration Gradients with Palladium Infused Mesoporous-Titania on D-Shaped Optical Fiber.

PubMed

Poole, Zsolt L; Ohodnicki, Paul R; Yan, Aidong; Lin, Yuankun; Chen, Kevin P

2017-01-27

A distributed sensing capable high temperature D-shaped optical fiber modified with a palladium nanoparticle sensitized mesoporous (∼5 nm) TiO 2 film, is demonstrated. The refractive index of the TiO 2 film was reduced using block copolymer templating in order to realize a mesoporous matrix, accommodating integration with optical fiber. The constructed sensor was analyzed by performing direct transmission loss measurements, and by analyzing the behavior of an integrated fiber Bragg grating. The inscribed grating should reveal whether the refractive index of the composite film experiences changes upon exposure to hydrogen. In addition, with frequency domain reflectometry the distributed sensing potential of the developed sensor for hydrogen concentrations of up to 10% is examined. The results show the possibility of detecting chemical gradients with sub-cm resolution at temperatures greater than 500 °C.

Navy Exploitation of SeaWiFS and MODIS Satellite Imagery for Detection of Desert Dust Storms Over Land and Water

NASA Astrophysics Data System (ADS)

Miller, S. D.

2002-12-01

The United States Navy gives serious consideration to the subject of dust detection. In a recent study of Naval aviation mishaps over the period 1990-1998 (Cantu, 2001), it was found that 70% were associated with visibility problems and accounted for annual equipment losses of nearly 50 million dollars. This figure does not include the tax dollars lost in jettisoned or off-target ordnance owing to obscured targets or failure of laser-guided systems in the presence of significant dust. Nor can it account for the loss of life during a subset of these mishaps. As such, a strong research emphasis has been placed on detecting and quantifying dust over data-sparse/denied parts of the world. The prolific and complex dust climatology of Southwest Asia has posed considerable challenges to Navy operations over the course of Operation Enduring Freedom. In an effort to support the ongoing needs of the Meteorology/Oceanography (METOC) officers afloat, the Satellite Applications Section of the Naval Research Laboratory (NRL) Marine Meteorology Division has developed a novel approach to enhancing significant dust events that appeals to high spatial and spectral resolution satellite data currently available from state of the art ocean/atmospheric radiometers. This paper summarizes progress made on daytime enhancements of desert dust storms over both land and ocean using multispectral imagery from the Moderate Resolution Imaging Spectroradiometer (MODIS; aboard Earth Observing System Terra and Aqua platforms) and the Sea-viewing Wide Field-of-view Sensor (SeaWiFS; aboard the NASA/Orbimage SeaStar platform). The approach leverages the multi-spectral visible capability of these sensors to distinguish dust from clouds over water bodies, and the high spatial resolution required to refine the fine-scale structures that often accompany these events. The MODIS algorithm combines this information with that of several near-to-far infrared channels, taking advantage of unique spectral properties of dust found in these regimes, to extend the capability to detection of dust over land (bright backgrounds). An account for enhancement contamination in the presence of sun glint is also provided in these products. The SeaWiFS and MODIS telemetries are made available to NRL in near real-time, with product turn-around ranging from 3-6 hours from initial capture. An unprecedented intra-agency collaboration forged between NOAA, NASA (Goddard Space Flight Center), and the Department of Defense has resulted in the recent availability of a global Terra MODIS data stream, with the companion Aqua telemetry soon to follow. Preliminary METOC feedback regarding these products has been overwhelmingly positive, and provides the impetus for continued refinement. Examples of the current product's capabilities and limitations will be presented.

Advancing the capabilities of reservoir remote sensing by leveraging multi-source satellite data

NASA Astrophysics Data System (ADS)

Gao, H.; Zhang, S.; Zhao, G.; Li, Y.

2017-12-01

With a total global capacity of more than 6000 km3, reservoirs play a key role in the hydrological cycle and in water resources management. However, essential reservoir data (e.g., elevation, storage, and evaporation loss) are usually not shared at a large scale. While satellite remote sensing offers a unique opportunity for monitoring large reservoirs from space, the commonly used radar altimeters can only detect storage variations of about 15% of global lakes at a repeat period of 10 days or longer. To advance the capabilities of reservoir sensing, we developed a series of algorithms geared towards generating long term reservoir records at improved spatial coverage, and at improved temporal resolution. To this goal, observations are leveraged from multiple satellite sensors, which include radar/laser altimeters, imagers, and passive microwave radiometers. In South Asia, we demonstrate that reservoir storage can be estimated under all-weather conditions at a 4 day time step, with the total capacity of monitored reservoirs increased to 45%. Within the Continuous United States, a first Landsat based evaporation loss dataset was developed (containing 204 reservoirs) from 1984 to 2011. The evaporation trends of these reservoirs are identified and the causes are analyzed. All of these algorithms and products were validated with gauge observations. Future satellite missions, which will make significant contributions to monitoring global reservoirs, are also discussed.

Rainfall erosivity: An historical review

USDA-ARS?s Scientific Manuscript database

Rainfall erosivity is the capability of rainfall to cause soil loss from hillslopes by water. Modern definitions of rainfall erosivity began with the development of the Universal Soil Loss Equation (USLE), where rainfall characteristics were statistically related to soil loss from thousands of plot...

Reversed oxygen sensing using colloidal quantum wells towards highly emissive photoresponsive varnishes

PubMed Central

Lorenzon, Monica; Christodoulou, Sotirios; Vaccaro, Gianfranco; Pedrini, Jacopo; Meinardi, Francesco; Moreels, Iwan; Brovelli, Sergio

2015-01-01

Colloidal quantum wells combine the advantages of size-tunable electronic properties with vast reactive surfaces that could allow one to realize highly emissive luminescent-sensing varnishes capable of detecting chemical agents through their reversible emission response, with great potential impact on life sciences, environmental monitoring, defence and aerospace engineering. Here we combine spectroelectrochemical measurements and spectroscopic studies in a controlled atmosphere to demonstrate the ‘reversed oxygen-sensing’ capability of CdSe colloidal quantum wells, that is, the exposure to oxygen reversibly increases their luminescence efficiency. Spectroelectrochemical experiments allow us to directly relate the sensing response to the occupancy of surface states. Magneto-optical measurements demonstrate that, under vacuum, heterostructured CdSe/CdS colloidal quantum wells stabilize in their negative trion state. The high starting emission efficiency provides a possible means to enhance the oxygen sensitivity by partially de-passivating the particle surfaces, thereby enhancing the density of unsaturated sites with a minimal cost in term of luminescence losses. PMID:25910499

Serological responses and immunity to superinfection with avian malaria in experimentally-infected Hawaii Amakihi

USGS Publications Warehouse

Atkinson, Carter T.; Dusek, Robert J.; Lease, Julie K.

2001-01-01

Six of seven Hawaii Amakihi (Hemignathus virens) with chronic malarial infections had no increases in peripheral parasitemia, declines in food consumption, or loss of body weight when rechallenged with the homologous isolate of Plasmodium relictum 61 to 62 days after initial infection. Five uninfected control amakihi exposed at the same time to infective mosquito bites developed acute infections with high parasitemias. Reductions in food consumption and loss of body weight occurred in all control birds and three of these individuals eventually died. When surviving birds were rechallenged >2 yr later with either the same parasite isolate or an isolate of P. relictum collected on the island of Kauai, all individuals were immune to superinfection. Chronically infected birds developed antibodies to a common suite of malarial antigens ranging in size from 22 to 170 kDa that were detectable as early as 8 days post infection on immunoblots of SDS-polyacrylamide gels. Antibodies to this suite of malarial antigens persisted as long as 1,248 days after initial infection and were consistently detectable at times when parasites were not easily found by microscopy on Giemsa-stained blood smears. The immunoblotting method that is described here appears to be an effective technique for identifying birds with chronic, low-intensity malarial infections when circulating parasites are not easily detectable by microscopy. Hawaiian honeycreepers that are capable of recovering from acute infections develop concomitant immunity to superinfection, making them functionally immune in areas where malaria transmission has become endemic.

Abort Trigger False Positive and False Negative Analysis Methodology for Threshold-Based Abort Detection

NASA Technical Reports Server (NTRS)

Melcher, Kevin J.; Cruz, Jose A.; Johnson Stephen B.; Lo, Yunnhon

2015-01-01

This paper describes a quantitative methodology for bounding the false positive (FP) and false negative (FN) probabilities associated with a human-rated launch vehicle abort trigger (AT) that includes sensor data qualification (SDQ). In this context, an AT is a hardware and software mechanism designed to detect the existence of a specific abort condition. Also, SDQ is an algorithmic approach used to identify sensor data suspected of being corrupt so that suspect data does not adversely affect an AT's detection capability. The FP and FN methodologies presented here were developed to support estimation of the probabilities of loss of crew and loss of mission for the Space Launch System (SLS) which is being developed by the National Aeronautics and Space Administration (NASA). The paper provides a brief overview of system health management as being an extension of control theory; and describes how ATs and the calculation of FP and FN probabilities relate to this theory. The discussion leads to a detailed presentation of the FP and FN methodology and an example showing how the FP and FN calculations are performed. This detailed presentation includes a methodology for calculating the change in FP and FN probabilities that result from including SDQ in the AT architecture. To avoid proprietary and sensitive data issues, the example incorporates a mixture of open literature and fictitious reliability data. Results presented in the paper demonstrate the effectiveness of the approach in providing quantitative estimates that bound the probability of a FP or FN abort determination.

Radiological Environmental Protection for LCLS-II High Power Operation

NASA Astrophysics Data System (ADS)

Liu, James; Blaha, Jan; Cimeno, Maranda; Mao, Stan; Nicolas, Ludovic; Rokni, Sayed; Santana, Mario; Tran, Henry

2017-09-01

The LCLS-II superconducting electron accelerator at SLAC plans to operate at up to 4 GeV and 240 kW average power, which would create higher radiological impacts particularly near the beam loss points such as beam dumps and halo collimators. The main hazards to the public and environment include direct or skyshine radiation, effluent of radioactive air such as 13N, 15O and 41Ar, and activation of groundwater creating tritium. These hazards were evaluated using analytic methods and FLUKA Monte Carlo code. The controls (mainly extensive bulk shielding and local shielding around high loss points) and monitoring (neutron/photon detectors with detection capabilities below natural background at site boundary, site-wide radioactive air monitors, and groundwater wells) were designed to meet the U.S. DOE and EPA, as well as SLAC requirements. The radiological design and controls for the LCW systems [including concrete housing shielding for 15O and 11C circulating in LCW, 7Be and erosion/corrosion products (22Na, 54Mn, 60Co, 65Zn, etc.) captured in resin and filters, leak detection and containment of LCW with 3H and its waste water discharge; explosion from H2 build-up in surge tank and release of radionuclides] associated with the high power beam dumps are also presented.

Orion GN&C Fault Management System Verification: Scope And Methodology

NASA Technical Reports Server (NTRS)

Brown, Denise; Weiler, David; Flanary, Ronald

2016-01-01

In order to ensure long-term ability to meet mission goals and to provide for the safety of the public, ground personnel, and any crew members, nearly all spacecraft include a fault management (FM) system. For a manned vehicle such as Orion, the safety of the crew is of paramount importance. The goal of the Orion Guidance, Navigation and Control (GN&C) fault management system is to detect, isolate, and respond to faults before they can result in harm to the human crew or loss of the spacecraft. Verification of fault management/fault protection capability is challenging due to the large number of possible faults in a complex spacecraft, the inherent unpredictability of faults, the complexity of interactions among the various spacecraft components, and the inability to easily quantify human reactions to failure scenarios. The Orion GN&C Fault Detection, Isolation, and Recovery (FDIR) team has developed a methodology for bounding the scope of FM system verification while ensuring sufficient coverage of the failure space and providing high confidence that the fault management system meets all safety requirements. The methodology utilizes a swarm search algorithm to identify failure cases that can result in catastrophic loss of the crew or the vehicle and rare event sequential Monte Carlo to verify safety and FDIR performance requirements.

O absorption measurements in an engineering-scale high-pressure coal gasifier

NASA Astrophysics Data System (ADS)

Sun, Kai; Sur, Ritobrata; Jeffries, Jay B.; Hanson, Ronald K.; Clark, Tommy; Anthony, Justin; Machovec, Scott; Northington, John

2014-10-01

A real-time, in situ water vapor (H2O) sensor using a tunable diode laser near 1,352 nm was developed to continuously monitor water vapor in the synthesis gas of an engineering-scale high-pressure coal gasifier. Wavelength-scanned wavelength-modulation spectroscopy with second harmonic detection (WMS-2 f) was used to determine the absorption magnitude. The 1 f-normalized, WMS-2 f signal (WMS-2 f/1 f) was insensitive to non-absorption transmission losses including beam steering and light scattering by the particulate in the synthesis gas. A fitting strategy was used to simultaneously determine the water vapor mole fraction and the collisional-broadening width of the transition from the scanned 1 f-normalized WMS-2 f waveform at pressures up to 15 atm, which can be used for large absorbance values. This strategy is analogous to the fitting strategy for wavelength-scanned direct absorption measurements. In a test campaign at the US National Carbon Capture Center, the sensor demonstrated a water vapor detection limit of ~800 ppm (25 Hz bandwidth) at conditions with more than 99.99 % non-absorption transmission losses. Successful unattended monitoring was demonstrated over a 435 h period. Strong correlations between the sensor measurements and transient gasifier operation conditions were observed, demonstrating the capability of laser absorption to monitor the gasification process.

Flight demonstration of a self repairing flight control system in a NASA F-15 fighter aircraft

NASA Technical Reports Server (NTRS)

Urnes, James M.; Stewart, James; Eslinger, Robert

1990-01-01

Battle damage causing loss of control capability can compromise mission objectives and even result in aircraft loss. The Self Repairing Flight Control System (SRFCS) flight development program directly addresses this issue with a flight control system design that measures the damage and immediately refines the control system commands to preserve mission potential. The system diagnostics process detects in flight the type of faults that are difficult to isolate post flight, and thus cause excessive ground maintenance time and cost. The control systems of fighter aircraft have the control power and surface displacement to maneuver the aircraft in a very large flight envelope with a wide variation in airspeed and g maneuvering conditions, with surplus force capacity available from each control surface. Digital flight control processors are designed to include built-in status of the control system components, as well as sensor information on aircraft control maneuver commands and response. In the event of failure or loss of a control surface, the SRFCS utilizes this capability to reconfigure control commands to the remaining control surfaces, thus preserving maneuvering response. Correct post-flight repair is the key to low maintainability support costs and high aircraft mission readiness. The SRFCS utilizes the large data base available with digital flight control systems to diagnose faults. Built-in-test data and sensor data are used as inputs to an Onboard Expert System process to accurately identify failed components for post-flight maintenance action. This diagnostic technique has the advantage of functioning during flight, and so is especially useful in identifying intermittent faults that are present only during maneuver g loads or high hydraulic flow requirements. A flight system was developed to test the reconfiguration and onboard maintenance diagnostics concepts on a NASA F-15 fighter aircraft.

Mineral and nitrogen metabolic studies, experiment M071

NASA Technical Reports Server (NTRS)

Whedon, G. D.; Lutwak, L.; Rambaut, P. C.; Whittle, M. W.; Smith, M. C., Jr.; Reid, J.; Leach, C. S.; Stadler, C. R.; Sanford, D. D.

1977-01-01

The similarity between bed rest test and space flight effects on human mineral and nitrogen metabolisms indicates impairment of capable musculoskeletal functions. A pattern of urinary calcium increases and total calcium shifts suggests that calcium losses continue with time. Significant losses of nitrogen and phosphorus are associated with reduction in muscle tissue. It is concluded that capable musculoskeletal function is likely to be impaired during space flights of 1 1/2 to 3 years duration.

Innovative Sensors for Pipeline Crawlers: Rotating Permanent Magnet Inspection

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

J. Bruce Nestleroth; Richard J. Davis; Stephanie Flamberg

2006-09-30

Internal inspection of pipelines is an important tool for ensuring safe and reliable delivery of fossil energy products. Current inspection systems that are propelled through the pipeline by the product flow cannot be used to inspect all pipelines because of the various physical barriers they may encounter. To facilitate inspection of these ''unpiggable'' pipelines, recent inspection development efforts have focused on a new generation of powered inspection platforms that are able to crawl slowly inside a pipeline and can maneuver past the physical barriers that limit internal inspection applicability, such as bore restrictions, low product flow rate, and low pressure.more » The first step in this research was to review existing inspection technologies for applicability and compatibility with crawler systems. Most existing inspection technologies, including magnetic flux leakage and ultrasonic methods, had significant implementation limitations including mass, physical size, inspection energy coupling requirements and technology maturity. The remote field technique was the most promising but power consumption was high and anomaly signals were low requiring sensitive detectors and electronics. After reviewing each inspection technology, it was decided to investigate the potential for a new inspection method. The new inspection method takes advantage of advances in permanent magnet strength, along with their wide availability and low cost. Called rotating permanent magnet inspection (RPMI), this patent pending technology employs pairs of permanent magnets rotating around the central axis of a cylinder to induce high current densities in the material under inspection. Anomalies and wall thickness variations are detected with an array of sensors that measure local changes in the magnetic field produced by the induced current flowing in the material. This inspection method is an alternative to the common concentric coil remote field technique that induces low-frequency eddy currents in ferromagnetic pipes and tubes. Since this is a new inspection method, both theory and experiment were used to determine fundamental capabilities and limitations. Fundamental finite element modeling analysis and experimental investigations performed during this development have led to the derivation of a first order analytical equation for designing rotating magnetizers to induce current and positioning sensors to record signals from anomalies. Experimental results confirm the analytical equation and the finite element calculations provide a firm basis for the design of RPMI systems. Experimental results have shown that metal loss anomalies and wall thickness variations can be detected with an array of sensors that measure local changes in the magnetic field produced by the induced current flowing in the material. The design exploits the phenomenon that circumferential currents are easily detectable at distances well away from the magnets. Current changes at anomalies were detectable with commercial low cost Hall Effect sensors. Commercial analog to digital converters can be used to measure the sensor output and data analysis can be performed in real time using PC computer systems. The technology was successfully demonstrated during two blind benchmark tests where numerous metal loss defects were detected. For this inspection technology, the detection threshold is a function of wall thickness and corrosion depth. For thinner materials, the detection threshold was experimentally shown to be comparable to magnetic flux leakage. For wall thicknesses greater than three tenths of an inch, the detection threshold increases with wall thickness. The potential for metal loss anomaly sizing was demonstrated in the second benchmarking study, again with accuracy comparable to existing magnetic flux leakage technologies. The rotating permanent magnet system has the potential for inspecting unpiggable pipelines since the magnetizer configurations can be sufficiently small with respect to the bore of the pipe to pass obstructions that limit the application of many inspection technologies. Also, since the largest dimension of the Hall Effect sensor is two tenths of an inch, the sensor packages can be small, flexible and light. The power consumption, on the order of ten watts, is low compared to some inspection systems; this would enable autonomous systems to inspect longer distances between charges. This project showed there are no technical barriers to building a field ready unit that can pass through narrow obstructions, such as plug valves. The next step in project implementation is to build a field ready unit that can begin to establish optimal performance capabilities including detection thresholds, sizing capability, and wall thickness limitations.« less

Methodology for Wide Band-Gap Device Dynamic Characterization

DOE PAGES

Zhang, Zheyu; Guo, Ben; Wang, Fei Fred; ...

2017-01-19

Here, the double pulse test (DPT) is a widely accepted method to evaluate the dynamic behavior of power devices. Considering the high switching-speed capability of wide band-gap devices, the test results are very sensitive to the alignment of voltage and current (V-I) measurements. Also, because of the shoot-through current induced by Cdv/dt (i.e., cross-talk), the switching losses of the nonoperating switch device in a phase-leg must be considered in addition to the operating device. This paper summarizes the key issues of the DPT, including components and layout design, measurement considerations, grounding effects, and data processing. Additionally, a practical method ismore » proposed for phase-leg switching loss evaluation by calculating the difference between the input energy supplied by a dc capacitor and the output energy stored in a load inductor. Based on a phase-leg power module built with 1200-V/50-A SiC MOSFETs, the test results show that this method can accurately evaluate the switching loss of both the upper and lower switches by detecting only one switching current and voltage, and it is immune to V-I timing misalignment errors.« less

3-Hydroxyanthranilate oxygenase activity is increased in the brains of Huntington disease victims

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

Schwarcz, R.; Okuno, E.; White, R.J.

1988-06-01

An excess of the tryptophan metabolite quinolinic acid in the brain has been hypothetically related to the pathogenesis of Huntington disease. Quinolinate's immediate biosynthetic enzyme, 3-hydroxyanthranilate oxygenase, has now been detected in human brain tissue. The activity of 3-hydroxyanthranilate oxygenase is increased in Huntington disease brains as compared to control brains. The increment is particularly pronounced in the striatum, which is known to exhibit the most prominent nerve-cell loss in Huntington disease. Thus, the Huntington disease brain has a disproportionately high capability to produce the endogenous excitotoxin quinolinic acid. This finding may be of relevance for clinical, neuropathologic, and biochemicalmore » features associated with Huntington disease.« less

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

Kaznatcheev, K.; Bertwistle, D.; Cheng, C.

We have explored the capabilities of synchronous ('lock-in') point detection techniques to enhance the x-ray magnetic circular dichroism (XMCD) contrast in scanning x-ray transmission microscopy (STXM) of magnetic thin-film microstructures. Local absorption contrast, measured synchronously with low-amplitude (<10 Oe) and low-frequency (<200 hz) longitudinal fields perturbing the near-remanent magnetization state, reveal a strong spatial dependence of the response, with a roll-off in frequency response above 200 Hz. In this context, synchronous measurement affords us a basis for imaging the relation between energy loss and the sweeping rate. We speculate that the lock-in approach will be uniquely suited for detailing stochasticmore » and deterministic frequency-dependent events in the process of magnetization reversal.« less

General intelligence predicts memory change across sleep.

PubMed

Fenn, Kimberly M; Hambrick, David Z

2015-06-01

Psychometric intelligence (g) is often conceptualized as the capability for online information processing but it is also possible that intelligence may be related to offline processing of information. Here, we investigated the relationship between psychometric g and sleep-dependent memory consolidation. Participants studied paired-associates and were tested after a 12-hour retention interval that consisted entirely of wake or included a regular sleep phase. We calculated the number of word-pairs that were gained and lost across the retention interval. In a separate session, participants completed a battery of cognitive ability tests to assess g. In the wake group, g was not correlated with either memory gain or memory loss. In the sleep group, we found that g correlated positively with memory gain and negatively with memory loss. Participants with a higher level of general intelligence showed more memory gain and less memory loss across sleep. Importantly, the correlation between g and memory loss was significantly stronger in the sleep condition than in the wake condition, suggesting that the relationship between g and memory loss across time is specific to time intervals that include sleep. The present research suggests that g not only reflects the capability for online cognitive processing, but also reflects capability for offline processes that operate during sleep.

Representation of Small-Arms Effects in Aggregated Force-on-Force Combat Models.

DTIC Science & Technology

1984-03-01

CONPUTATICY OF FORCE RATIO AND FRACTIONAL VALUE LOST 54 ***** 0 G. SCALING* COMPUTATION OF CASUALTIES AND WlAPCN LOSSES .. .. .. .. .. .. .. .. . .56 VI...ammo because cf its weight or his adversary with an AK-47 capable of rapid rates of accurate fire? The argument for the long- range kill capability of...LEVEL INDEPENDENT 8. IRE ALLOCATION ICT EXPLICITY CONSIDERED 9. SYMB!TRIC 10. 30 CCNSIDERXTION CF NONCOMBAT LOSSES (E.G. DESERTIONS, S URRENDERS) 11

Loss of Interneuron-Derived Collagen XIX Leads to a Reduction in Perineuronal Nets in the Mammalian Telencephalon.

PubMed

Su, Jianmin; Cole, James; Fox, Michael A

2017-02-01

Perineuronal nets (PNNs) are lattice-like supramolecular assemblies of extracellular glycoproteins that surround subsets of neuronal cell bodies in the mammalian telencephalon. PNNs emerge at the end of the critical period of brain development, limit neuronal plasticity in the adult brain, and are lost in a variety of complex brain disorders diseases, including schizophrenia. The link between PNNs and schizophrenia led us to question whether neuronally expressed extracellular matrix (ECM) molecules associated with schizophrenia contribute to the assembly of these specialized supramolecular ECM assemblies. We focused on collagen XIX-a minor, nonfibrillar collagen expressed by subsets of telencephalic interneurons. Genetic alterations in the region encoding collagen XIX have been associated with familial schizophrenia, and loss of this collagen in mice results in altered inhibitory synapses, seizures, and the acquisition of schizophrenia-related behaviors. Here, we demonstrate that loss of collagen XIX also results in a reduction of telencephalic PNNs. Loss of PNNs was accompanied with reduced levels of aggrecan (Acan), a major component of PNNs. Despite reduced levels of PNN constituents in collagen XIX-deficient mice ( col19a1 - / - ), we failed to detect reduced expression of genes encoding these ECM molecules. Instead, we discovered a widespread upregulation of extracellular proteases capable of cleaving Acan and other PNN constituents in col19a1 - / - brains. Taken together, these results suggest a mechanism by which the loss of collagen XIX speeds PNN degradation and they identify a novel mechanism by which the loss of collagen XIX may contribute to complex brain disorders.

Automatic Detection of Diseased Tomato Plants Using Thermal and Stereo Visible Light Images

PubMed Central

Raza, Shan-e-Ahmed; Prince, Gillian; Clarkson, John P.; Rajpoot, Nasir M.

2015-01-01

Accurate and timely detection of plant diseases can help mitigate the worldwide losses experienced by the horticulture and agriculture industries each year. Thermal imaging provides a fast and non-destructive way of scanning plants for diseased regions and has been used by various researchers to study the effect of disease on the thermal profile of a plant. However, thermal image of a plant affected by disease has been known to be affected by environmental conditions which include leaf angles and depth of the canopy areas accessible to the thermal imaging camera. In this paper, we combine thermal and visible light image data with depth information and develop a machine learning system to remotely detect plants infected with the tomato powdery mildew fungus Oidium neolycopersici. We extract a novel feature set from the image data using local and global statistics and show that by combining these with the depth information, we can considerably improve the accuracy of detection of the diseased plants. In addition, we show that our novel feature set is capable of identifying plants which were not originally inoculated with the fungus at the start of the experiment but which subsequently developed disease through natural transmission. PMID:25861025

Examination of Icing Induced Loss of Control and Its Mitigations

NASA Technical Reports Server (NTRS)

Reehorst, Andrew L.; Addy, Harold E., Jr.; Colantonio, Renato O.

2010-01-01

Factors external to the aircraft are often a significant causal factor in loss of control (LOC) accidents. In today s aviation world, very few accidents stem from a single cause and typically have a number of causal factors that culminate in a LOC accident. Very often the "trigger" that initiates an accident sequence is an external environment factor. In a recent NASA statistical analysis of LOC accidents, aircraft icing was shown to be the most common external environmental LOC causal factor for scheduled operations. When investigating LOC accident or incidents aircraft icing causal factors can be categorized into groups of 1) in-flight encounter with super-cooled liquid water clouds, 2) take-off with ice contamination, or 3) in-flight encounter with high concentrations of ice crystals. As with other flight hazards, icing induced LOC accidents can be prevented through avoidance, detection, and recovery mitigations. For icing hazards, avoidance can take the form of avoiding flight into icing conditions or avoiding the hazard of icing by making the aircraft tolerant to icing conditions. Icing detection mitigations can take the form of detecting icing conditions or detecting early performance degradation caused by icing. Recovery from icing induced LOC requires flight crew or automated systems capable of accounting for reduced aircraft performance and degraded control authority during the recovery maneuvers. In this report we review the icing induced LOC accident mitigations defined in a recent LOC study and for each mitigation describe a research topic required to enable or strengthen the mitigation. Many of these research topics are already included in ongoing or planned NASA icing research activities or are being addressed by members of the icing research community. These research activities are described and the status of the ongoing or planned research to address the technology needs is discussed

Species-specific multiplex PCR for the diagnosis of Brucella ovis, Actinobacillus seminis, and Histophilus somni infection in rams.

PubMed

Moustacas, Valéria S; Silva, Teane M A; Costa, Luciana F; Xavier, Mariana N; Carvalho, Custódio A; Costa, Érica A; Paixão, Tatiane A; Santos, Renato L

2013-03-21

Infectious ovine epididymitis results in substantial economic losses worldwide due to reproductive failure and culling of breeders. The most common causative agents of these infections are Brucella ovis, Actinobacillus seminis, and Histophilus somni. The aim of this study was to develop a multiplex PCR assay for simultaneous detection of Brucella ovis, Actinobacillus seminis, and Histophilus somni with species-specific primers applied to biological samples for molecular diagnosis of these infections. The multiplex assay was capable of detecting B. ovis, A. seminis, and H. somni DNA simultaneously from genomic bacterial DNA samples and pool of semen samples from experimentally infected rams. The method was highly specific since it did not amplify DNA from other bacterial species that can potentially cause epididymitis in rams as well as species phylogenetically related to B. ovis. All negative control samples were negative in PCR multiplex assay. Urine can be used as an alternative to semen samples. The species-specific multiplex PCR assay developed in this study can be successfully used for the detection of three of the most common bacterial causes of ovine epididymitis.

Damage Detection and Verification System (DDVS) for In-Situ Health Monitoring

NASA Technical Reports Server (NTRS)

Williams, Martha K.; Lewis, Mark; Szafran, J.; Shelton, C.; Ludwig, L.; Gibson, T.; Lane, J.; Trautwein, T.

2015-01-01

Project presentation for Game Changing Program Smart Book Release. Detection and Verification System (DDVS) expands the Flat Surface Damage Detection System (FSDDS) sensory panels damage detection capabilities and includes an autonomous inspection capability utilizing cameras and dynamic computer vision algorithms to verify system health. Objectives of this formulation task are to establish the concept of operations, formulate the system requirements for a potential ISS flight experiment, and develop a preliminary design of an autonomous inspection capability system that will be demonstrated as a proof-of-concept ground based damage detection and inspection system.

Study of gamma detection capabilities of the REWARD mobile spectroscopic system

NASA Astrophysics Data System (ADS)

Balbuena, J. P.; Baptista, M.; Barros, S.; Dambacher, M.; Disch, C.; Fiederle, M.; Kuehn, S.; Parzefall, U.

2017-07-01

REWARD is a novel mobile spectroscopic radiation detector system for Homeland Security applications. The system integrates gamma and neutron detection equipped with wireless communication. A comprehensive simulation study on its gamma detection capabilities in different radioactive scenarios is presented in this work. The gamma detection unit consists of a precise energy resolution system based on two stacked (Cd,Zn)Te sensors working in coincidence sum mode. The volume of each of these CZT sensors is 1 cm3. The investigated energy windows used to determine the detection capabilities of the detector correspond to the gamma emissions from 137Cs and 60Co radioactive sources (662 keV and 1173/1333 keV respectively). Monte Carlo and Technology Computer-Aided Design (TCAD) simulations are combined to determine its sensing capabilities for different radiation sources and estimate the limits of detection of the sensing unit as a function of source activity for several shielding materials.

Label free detection of phospholipids by infrared absorption spectroscopy

NASA Astrophysics Data System (ADS)

Ahmed, Tahsin; Foster, Erick; Vigil, Genevieve; Khan, Aamir A.; Bohn, Paul; Howard, Scott S.

2014-08-01

We present our study on compact, label-free dissolved lipid sensing by combining capillary electrophoresis separation in a PDMS microfluidic chip online with mid-infrared (MIR) absorption spectroscopy for biomarker detection. On-chip capillary electrophoresis is used to separate the biomarkers without introducing any extrinsic contrast agent, which reduces both cost and complexity. The label free biomarker detection could be done by interrogating separated biomarkers in the channel by MIR absorption spectroscopy. Phospholipids biomarkers of degenerative neurological, kidney, and bone diseases are detectable using this label free technique. These phospholipids exhibit strong absorption resonances in the MIR and are present in biofluids including urine, blood plasma, and cerebrospinal fluid. MIR spectroscopy of a 12-carbon chain phosphatidic acid (PA) (1,2-dilauroyl-snglycero- 3-phosphate (sodium salt)) dissolved in N-methylformamide, exhibits a strong amide peak near wavenumber 1660 cm-1 (wavelength 6 μm), arising from the phosphate headgroup vibrations within a low-loss window of the solvent. PA has a similar structure to many important phospholipids molecules like phosphatidylcholine (PC), phosphatidylinositol (PI), phosphatidylethanolamine (PE), phosphatidylglycerol (PG), and phosphatidylserine (PS), making it an ideal molecule for initial proof-of-concept studies. This newly proposed detection technique can lead us to minimal sample preparation and is capable of identifying several biomarkers from the same sample simultaneously.

Stand-off detection of explosives vapors by resonance-enhanced Raman spectroscopy

NASA Astrophysics Data System (ADS)

Johansson, Ida; Ceco, Ema; Ehlerding, Anneli; Östmark, Henric

2013-06-01

This paper describes a system for stand-off vapor detection based on Resonant Raman spectroscopy, RRS. The system is a step towards a RRS LIDAR (Light Detection And Ranging) system, capable of detecting vapors from explosives and explosives precursors at long distances. The current system was used to detect the vapor of nitromethane and mononitrotoluene outdoors in the open air, at a stand-off distance of 11-13 meters. Also, the signal dependence upon irradiation wavelength and sample concentration was studied in controlled laboratory conditions. A tunable Optical Parametric Oscillator pumped by an Nd:YAG laser, with a pulse length of 6 ns, was operated in the UV range of interest, 210-400 nm, illuminating the sample vapor. The backscattered Raman signal was collected by a telescope and a roundto- slit optical fiber was used to transmit collected light to the spectrometer with minimum losses. A gated intensified charge-coupled device (ICCD) registered the spectra. The nitromethane cross section was resonance enhanced more than a factor 30 700, when measured at 220 nm, compared to the 532 nm value. The results show that a decrease in concentration can have a positive effect on the sensitivity of the system, due to a decrease in absorption and selfabsorption in the sample.

NDE detectability of fatigue-type cracks in high-strength alloys: NDI reliability assessments

NASA Technical Reports Server (NTRS)

Christner, Brent K.; Long, Donald L.; Rummel, Ward D.

1988-01-01

This program was conducted to generate quantitative flaw detection capability data for the nondestructive evaluation (NDE) techniques typically practiced by aerospace contractors. Inconel 718 and Haynes 188 alloy test specimens containing fatigue flaws with a wide distribution of sizes were used to assess the flaw detection capabilities at a number of contractor and government facilities. During this program 85 inspection sequences were completed presenting a total of 20,994 fatigue cracks to 53 different inspectors. The inspection sequences completed included 78 liquid penetrant, 4 eddy current, and 3 ultrasonic evaluations. The results of the assessment inspections are presented and discussed. In generating the flaw detection capability data base, procedures for data collection, data analysis, and specimen care and maintenance were developed, demonstrated, and validated. The data collection procedures and methods that evolved during this program for the measurement of flaw detection capabilities and the effects of inspection variables on performance are discussed. The Inconel 718 and Haynes 188 test specimens that were used in conducting this program and the NDE assessment procedures that were demonstrated, provide NASA with the capability to accurately assess the flaw detection capabilities of specific inspection procedures being applied or proposed for use on current and future fracture control hardware program.

Target Detection Routine (TADER). User’s Guide.

DTIC Science & Technology

1987-09-01

o System range capability subset (one record - omitted for standoff SLAR and penetrating system) o System inherent detection probability subset ( IELT ...records, i.e., one per element type) * System capability modifier subset/A=1, E=1 ( IELT records) o System capability modifier subset/A=1, E=2 ( IELT ...records) s System capability modifier subset/A=2, E=1 ( IELT records) o System capability modifier subset/A=2, E=2 ( IELT records) Unit Data Set (one set

BepiColombo Serena/ELENA instrument:development and testing

NASA Astrophysics Data System (ADS)

Orsini, S.; De Angelis, E.; Selci, S.; Di Lellis, A. M.:; Leoni, R.; Rispoli, R.; Colasanti, L.; Vertolli, N.; Scheer, J.; Mura, A.; Milillo, A.; Wurz, P.; D'Alessandro, M.; Maschietti, D.; Mattioli, F.; Cibella, S.; Brienza, D.; lo Spazio, Compagnia Generale per

2012-04-01

ELENA is a TOF sensor, based on a novel concept ultra-sonic oscillating shutter (Start section) which is operated at frequencies up to 50 kHz; a MCP detector is used as a Stop section. It is aimed to detect neutral atoms in the range 10 eV - 5 keV, within 70° FOV, perpendicular to the S/C orbital plane. ELENA will monitor the emission of neutral atoms from the whole surface of Mercury thanks to the spacecraft motion. The major scientific objectives are the interaction between the environment and the planet, the global particle loss-rate and the remote sensing of the surface properties. In particular, surface release processes are investigated by identifying particles release from the surface, via solar wind-induced ion sputtering (<1eV - >100 eV) as well as Hydrogen back-scattered at hundreds eV. In particular, the capability to detect non-thermal low energy neutral species is crucial for the sensor ELENA (Emitted Low-Energy Neutral Atoms), part of the package SERENA (Search for Exospheric Refilling and Emitted Natural Abundances) on board the BepiColombo mission to Mercury to be launched in 2014. The instrument is now validated and tested to reach its performances: the up-graded shutter system (Start section) has been operated for the first time with neutral atom beam and tested at high frequency, the Stop section has been calibrated investigating the region of very low energy detection efficiency, the electronics boards and the entire acquisition chain has been appointed and tested with ion beam. The first results of all the ELENA capability will be presented.

Ultra-low loss Si3N4 waveguides with low nonlinearity and high power handling capability.

PubMed

Tien, Ming-Chun; Bauters, Jared F; Heck, Martijn J R; Blumenthal, Daniel J; Bowers, John E

2010-11-08

We investigate the nonlinearity of ultra-low loss Si3N4-core and SiO2-cladding rectangular waveguides. The nonlinearity is modeled using Maxwell's wave equation with a small amount of refractive index perturbation. Effective n2 is used to describe the third-order nonlinearity, which is linearly proportional to the optical intensity. The effective n2 measured using continuous-wave self-phase modulation shows agreement with the theoretical calculation. The waveguide with 2.8-μm wide and 80-nm thick Si3N4 core has low loss and high power handling capability, with an effective n2 of about 9×10(-16) cm2/W.

Infrared On-Orbit Inspection of Shuttle Orbiter Reinforced Carbon-Carbon Using Solar Heating

NASA Technical Reports Server (NTRS)

Howell, P. A.; Winfree, W. P.; Cramer, K. Elliott

2005-01-01

Thermographic nondestructive inspection techniques have been shown to provide quantitative, large area damage detection capabilities for the ground inspection of the reinforced carbon-carbon (RCC) used for the wing leading edge of the Shuttle orbiter. The method is non-contacting and able to inspect large areas in a relatively short inspection time. Thermal nondestructive evaluation (NDE) inspections have been shown to be applicable for several applications to the Shuttle in preparation for return to flight, including for inspection of RCC panels during impact testing, and for between-flight orbiter inspections. The focus of this work is to expand the capabilities of the thermal NDE methodology to enable inspection by an astronaut during orbital conditions. The significant limitations of available resources, such as weight and power, and the impact of these limitations on the inspection technique are discussed, as well as the resultant impact on data analysis and processing algorithms. Of particular interest is the impact to the inspection technique resulting from the use of solar energy as a heat source, the effect on the measurements due to working in the vacuum of space, and the effect of changes in boundary conditions, such as radiation losses seen by the material, on the response of the RCC. The resultant effects on detectability limits are discussed. Keywords: Nondestructive Evaluation, Shuttle, on-orbit inspection, thermography, infrared

Loss of DHR sequences at Browns Ferry Unit One - accident-sequence analysis

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

Cook, D.H.; Grene, S.R.; Harrington, R.M.

1983-05-01

This study describes the predicted response of Unit One at the Browns Ferry Nuclear Plant to a postulated loss of decay heat removal (DHR) capability following scram from full power with the power conversion system unavailable. In accident sequences without DHR capability, the residual heat removal (RHR) system functions of pressure suppression pool cooling and reactor vessel shutdown cooling are unavailable. Consequently, all decay heat energy is stored in the pressure suppression pool with a concomitant increase in pool temperature and primary containment pressure. With the assumption that DHR capability is not regained during the lengthy course of this accidentmore » sequence, the containment ultimately fails by overpressurization. Although unlikely, this catastrophic failure might lead to loss of the ability to inject cooling water into the reactor vessel, causing subsequent core uncovery and meltdown. The timing of these events and the effective mitigating actions that might be taken by the operator are discussed in this report.« less

Minimum Detectable Dose as a Measure of Bioassay Programme Capability

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

Carbaugh, Eugene H.

2003-01-01

This paper suggests that minimum detectable dose (MDD) be used to describe the capability of bioassay programs for which intakes are expected to be rare. This allows expression of the capability in units that correspond directly to primary dose limits. The concept uses the well-established analytical statistic minimum detectable amount (MDA) as the starting point and assumes MDA detection at a prescribed time post intake. The resulting dose can then be used as an indication of the adequacy or capability of the program for demonstrating compliance with the performance criteria. MDDs can be readily tabulated or plotted to demonstrate themore » effectiveness of different types of monitoring programs. The inclusion of cost factors for bioassay measurements can allow optimisation.« less

Minimum detectable dose as a measure of bioassay programme capability.

PubMed

Carbaugh, E H

2003-01-01

This paper suggests that minimum detectable dose (MDD) be used to describe the capability of bioassay programmes for which intakes are expected to be rare. This allows expression of the capability in units that correspond directly to primary dose limits. The concept uses the well established analytical statistic minimum detectable amount (MDA) as the starting point, and assumes MDA detection at a prescribed time post-intake. The resulting dose can then be used as an indication of the adequacy or capability of the programme for demonstrating compliance with the performance criteria. MDDs can be readily tabulated or plotted to demonstrate the effectiveness of different types of monitoring programmes. The inclusion of cost factors for bioassay measurements can allow optimisation.

A Performance Assessment of an Airborne Separation Assistance System Using Realistic Complex Traffic Flows

NASA Technical Reports Server (NTRS)

Smith, Jeremy C.; Bussink, Frank J. L.

2008-01-01

This paper presents the results from a study that investigates the performance of a tactical Airborne Separation Assistance System (ASAS) in en route airspace, under varying demand levels, with realistic traffic flows. The ASAS concept studied here allows flight crews of equipped aircraft to perform separation from other air traffic autonomously. This study addresses the tactical aspects of an ASAS using aircraft state data (i.e. position and velocity) to detect and resolve projected conflicts. In addition, use of a conflict prevention system helps ASAS-equipped aircraft avoid maneuvers that may cause new conflicts. ASAS-capable aircraft are equipped with satellite-based navigation and Automatic Dependent Surveillance Broadcast (ADS-B) for transmission and receipt of aircraft state data. In addition to tactical conflict detection and resolution (CD&R), a complete, integrated ASAS is likely to incorporate a strategic CD&R component with a longer look-ahead time, using trajectory intent information. A system-wide traffic flow management (TFM) component, located at the FAA command center helps aircraft to avoid regions of excessive traffic density and complexity. A Traffic Alert and Collision Avoidance System (TCAS), as used today is the system of last resort. This integrated approach avoids sole reliance on the use of the tactical CD&R studied here, but the tactical component remains a critical element of the complete ASAS. The focus of this paper is to determine to what extent the proposed tactical component of ASAS alone can maintain aircraft separation at demand levels up to three times that of current traffic. The study also investigates the effect of mixing ASAS-equipped aircraft with unequipped aircraft (i.e. current day) that do not have the capability to self-separate. Position and velocity data for unequipped aircraft needs to be available to ASASequipped. Most likely, for this future concept, state data would be available from instrument flight rules (IFR) aircraft, equipped with at least ADS-B transmission capability. The objective is to reduce the number of losses of separation to a minimum and investigate the limits of tactical-only CD&R. Thus, the objective is not, expressly, to achieve zero losses of separation with tactical ASAS because this is one component of an integrated ASAS.

76 FR 16250 - Planning Resource Adequacy Assessment Reliability Standard

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-23

..., to utilize a ``one day in ten years'' loss of load criterion, and to document and post load and...'' loss of load criterion, and to document and post load and resource capability in each area or..., based on ``one day in ten years'' loss of load expectation principles, for the analysis, assessment and...

A conditioned aversion study of sucrose and SC45647 taste in TRPM5 knockout mice.

PubMed

Eddy, Meghan C; Eschle, Benjamin K; Peterson, Darlene; Lauras, Nathan; Margolskee, Robert F; Delay, Eugene R

2012-06-01

Previously, published studies have reported mixed results regarding the role of the TRPM5 cation channel in signaling sweet taste by taste sensory cells. Some studies have reported a complete loss of sweet taste preference in TRPM5 knockout (KO) mice, whereas others have reported only a partial loss of sweet taste preference. This study reports the results of conditioned aversion studies designed to motivate wild-type (WT) and KO mice to respond to sweet substances. In conditioned taste aversion experiments, WT mice showed nearly complete LiCl-induced response suppression to sucrose and SC45647. In contrast, TRPM5 KO mice showed a much smaller conditioned aversion to either sweet substance, suggesting a compromised, but not absent, ability to detect sweet taste. A subsequent conditioned flavor aversion experiment was conducted to determine if TRPM5 KO mice were impaired in their ability to learn a conditioned aversion. In this experiment, KO and WT mice were conditioned to a mixture of SC45647 and amyl acetate (an odor cue). Although WT mice avoided both components of the stimulus mixture, they avoided SC45647 more than the odor cue. The KO mice also avoided both stimuli, but they avoided the odor component more than SC45647, suggesting that while the KO mice are capable of learning an aversion, to them the odor cue was more salient than the taste cue. Collectively, these findings suggest the TRPM5 KO mice have some residual ability to detect SC45647 and sucrose, and, like bitter, there may be a TRPM5-independent transduction pathway for detecting these substances.

Navy/Marine Corps innovative science and technology developments for future enhanced mine detection capabilities

NASA Astrophysics Data System (ADS)

Holloway, John H., Jr.; Witherspoon, Ned H.; Miller, Richard E.; Davis, Kenn S.; Suiter, Harold R.; Hilton, Russell J.

2000-08-01

JMDT is a Navy/Marine Corps 6.2 Exploratory Development program that is closely coordinated with the 6.4 COBRA acquisition program. The objective of the program is to develop innovative science and technology to enhance future mine detection capabilities. The objective of the program is to develop innovative science and technology to enhance future mine detection capabilities. Prior to transition to acquisition, the COBRA ATD was extremely successful in demonstrating a passive airborne multispectral video sensor system operating in the tactical Pioneer unmanned aerial vehicle (UAV), combined with an integrated ground station subsystem to detect and locate minefields from surf zone to inland areas. JMDT is investigating advanced technology solutions for future enhancements in mine field detection capability beyond the current COBRA ATD demonstrated capabilities. JMDT has recently been delivered next- generation, innovative hardware which was specified by the Coastal System Station and developed under contract. This hardware includes an agile-tuning multispectral, polarimetric, digital video camera and advanced multi wavelength laser illumination technologies to extend the same sorts of multispectral detections from a UAV into the night and over shallow water and other difficult littoral regions. One of these illumination devices is an ultra- compact, highly-efficient near-IR laser diode array. The other is a multi-wavelength range-gateable laser. Additionally, in conjunction with this new technology, algorithm enhancements are being developed in JMDT for future naval capabilities which will outperform the already impressive record of automatic detection of minefields demonstrated by the COBAR ATD.

Adaptable radiation monitoring system and method

DOEpatents

Archer, Daniel E [Livermore, CA; Beauchamp, Brock R [San Ramon, CA; Mauger, G Joseph [Livermore, CA; Nelson, Karl E [Livermore, CA; Mercer, Michael B [Manteca, CA; Pletcher, David C [Sacramento, CA; Riot, Vincent J [Berkeley, CA; Schek, James L [Tracy, CA; Knapp, David A [Livermore, CA

2006-06-20

A portable radioactive-material detection system capable of detecting radioactive sources moving at high speeds. The system has at least one radiation detector capable of detecting gamma-radiation and coupled to an MCA capable of collecting spectral data in very small time bins of less than about 150 msec. A computer processor is connected to the MCA for determining from the spectral data if a triggering event has occurred. Spectral data is stored on a data storage device, and a power source supplies power to the detection system. Various configurations of the detection system may be adaptably arranged for various radiation detection scenarios. In a preferred embodiment, the computer processor operates as a server which receives spectral data from other networked detection systems, and communicates the collected data to a central data reporting system.

HABITABLE ZONES OF POST-MAIN SEQUENCE STARS

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

Ramirez, Ramses M.; Kaltenegger, Lisa

Once a star leaves the main sequence and becomes a red giant, its Habitable Zone (HZ) moves outward, promoting detectable habitable conditions at larger orbital distances. We use a one-dimensional radiative-convective climate and stellar evolutionary models to calculate post-MS HZ distances for a grid of stars from 3700 to 10,000 K (∼M1 to A5 stellar types) for different stellar metallicities. The post-MS HZ limits are comparable to the distances of known directly imaged planets. We model the stellar as well as planetary atmospheric mass loss during the Red Giant Branch (RGB) and Asymptotic Giant Branch (AGB) phases for super-Moons tomore » super-Earths. A planet can stay between 200 million years up to 9 Gyr in the post-MS HZ for our hottest and coldest grid stars, respectively, assuming solar metallicity. These numbers increase for increased stellar metallicity. Total atmospheric erosion only occurs for planets in close-in orbits. The post-MS HZ orbital distances are within detection capabilities of direct imaging techniques.« less

Demise of Polymerase Chain Reaction/Electrospray Ionization-Mass Spectrometry as an Infectious Diseases Diagnostic Tool.

PubMed

Özenci, Volkan; Patel, Robin; Ullberg, Måns; Strålin, Kristoffer

2018-01-18

Although there are several US Food and Drug Administration (FDA)-approved/cleared molecular microbiology diagnostics for direct analysis of patient samples, all are single target or panel-based tests. There is no FDA-approved/cleared diagnostic for broad microbial detection. Polymerase chain reaction (PCR)/electrospray ionization-mass spectrometry (PCR/ESI-MS), commercialized as the IRIDICA system (Abbott) and formerly PLEX-ID, had been under development for over a decade and had become CE-marked and commercially available in Europe in 2014. Capable of detecting a large number of microorganisms, it was under review at the FDA when, in April 2017, Abbott discontinued it. This turn of events represents not only the loss of a potential diagnostic tool for infectious diseases but may be a harbinger of similar situations with other emerging and expensive microbial diagnostics, especially genomic tests. © The Author(s) 2017. Published by Oxford University Press for the Infectious Diseases Society of America. All rights reserved. For permissions, e-mail: journals.permissions@oup.com.

The SNAQ(RC), an easy traffic light system as a first step in the recognition of undernutrition in residential care.

PubMed

Kruizenga, H M; de Vet, H C W; Van Marissing, C M E; Stassen, E E P M; Strijk, J E; Van Bokhorst-de Van der Schueren, M A E; Horman, J C H; Schols, J M G A; Van Binsbergen, J J; Eliens, A; Knol, D L; Visser, M

2010-02-01

Development and validation of a quick and easy screening tool for the early detection of undernourished residents in nursing homes and residential homes. Multi-center, cross sectional observational study. Nursing homes and residential homes. The screening tool was developed in a total of 308 residents (development sample; sample A) and cross validated in a new sample of 720 residents (validation sample) consisting of 476 nursing home residents (Sample B1) and 244 residential home residents (sample B2). Patients were defined severely undernourished when they met at least one of the following criteria: BMI or= 5% unintentional weight loss in the past month and/or >or= 10% unintentional weight loss in the past 6 months. Patients were defined as moderately undernourished if they met the following criteria: BMI 20.1-22 kg/m2 and/or 5-10% unintentional weight loss in the past six months. The most predictive questions (originally derived from previously developed screening instruments) of undernourishment were selected in sample A and cross validated in sample B. In a second stage BMI was added to the SNAQRC in sample B. The diagnostic accuracy of the screening tool in the development and validation samples was expressed in sensitivity, specificity, and the negative and positive predictive value. The four most predictive questions for undernutrition related to: unintentional weight loss more than 6 kg during the past 6 months and more than 3 kg in the past month, capability of eating and drinking with help, and decreased appetite during the past month. The diagnostic accuracy of these questions alone was insufficient (Se=45%, Sp=87%, PPV=50% and NPV=84%). However, combining the questions with measured BMI sufficiently improved the diagnostic accuracy (Se=87%, Sp=82%, PPV=59% and NPV=95%). Early detection of undernourished nursing- and residential home residents is possible using four screening questions and measured BMI.

Preclinical Evaluation of a Decision Support Medical Monitoring System for Early Detection of Potential Hemodynamic Decompensation During Blood Loss in Humans

DTIC Science & Technology

2013-09-01

Hemodynamic Decompensation During Blood Loss in Humans PRINCIPAL INVESTIGATOR: Michael J. Joyner, M.D. CONTRACTING ORGANIZATION: Mayo Clinic...Medical Monitoring System for Early Detection of Potential Hemodynamic Decompensation During Blood Loss in Humans 5c. PROGRAM ELEMENT NUMBER 6...loss and hemorrhage in humans. The aim Is to be able to detect subtle changes in hemodynamic variables that provide prodromal clues to Impending

Concept for Inclusion of Analytical and Computational Capability in Optical Plume Anomaly Detection (OPAD) for Measurement of Neutron Flux

NASA Technical Reports Server (NTRS)

Patrick, Marshall Clint; Cooper, Anita E.; Powers, W. T.

2004-01-01

Researchers are working on many fronts to make possible high-speed, automated classification and quantification of constituent materials in numerous environments. NASA's Marshall Space Flight Center has implemented a system for rocket engine flowfields/plumes. The Optical Plume Anomaly Detector (OPAD) system was designed to utilize emission and absorption spectroscopy for monitoring molecular and atomic particulates in gas plasma. An accompanying suite of tools and analytical package designed to utilize information collected by OPAD is known as the Engine Diagnostic Filtering System (EDiFiS). The current combination of these systems identifies atomic and molecular species and quantifies mass loss rates in H2/O2 rocket plumes. Capabilities for real-time processing are being advanced on several fronts, including an effort to hardware encode components of the EDiFiS for health monitoring and management. This paper addresses the OPAD with its tool suites, and discusses what is considered a natural progression: a concept for taking OPAD to the next logical level of high energy physics, incorporating fermion and boson particle analyses in measurement of neutron flux.

Land cover change monitoring within the east central Louisiana study site: A case for large area surveys with LANDSAT multispectral scanner data

NASA Technical Reports Server (NTRS)

Burns, G. S.

1983-01-01

Results established for four digital procedures developed for characterizing the radiometric changes between multidate LANDSAT spectral data sets into meaningful measures of land cover/use dynamics are documented. Each technique's performance was contrasted against digitized land use change maps, which were produced from contemporaneous, retrospective aerophoto coverage, in a cell by cell comparison over a one half by one degree area in east central Louisiana as a standard for comparison. The four techniques identify from 10.5 to 13.0% loss in area of forestland in a five year period; however, they differ more by how accurately this amount of change is distributed, the need for ancillary ground truth, and amount of usable information that is extractable. All require some method of digitally co-registering the two data sets. All are capable of providing tabular statistics as well as map products. Two are capable of detecting changes and identifying their locations. The other two, in addition to this, provide information to qualify land cover conditions at each end of the study interval.

[Subclinical sensorineural hearing loss in female patients with rheumatoid arthritis].

PubMed

Treviño-González, José Luis; Villegas-González, Mario Jesús; Muñoz-Maldonado, Gerardo Enrique; Montero-Cantu, Carlos Alberto; Nava-Zavala, Arnulfo Hernán; Garza-Elizondo, Mario Alberto

2015-01-01

The rheumatoid arthritis is a clinical entity capable to cause hearing impairment that can be diagnosed promptly with high frequencies audiometry. To detect subclinical sensorineural hearing loss in patients with rheumatoid arthritis. Cross-sectional study on patients with rheumatoid arthritis performing high frequency audiometry 125Hz to 16,000Hz and tympanometry. The results were correlated with markers of disease activity and response to therapy. High frequency audiometry was performed in 117 female patients aged from 19 to 65 years. Sensorineural hearing loss was observed at a sensitivity of pure tones from 125 to 8,000 Hz in 43.59%, a tone threshold of 10,000 to 16,000Hz in 94.02% patients in the right ear and in 95.73% in the left ear. Hearing was normal in 8 (6.84%) patients. Hearing loss was observed in 109 (93.16%), and was asymmetric in 36 (30.77%), symmetric in 73 (62.37%), bilateral in 107 (91.45%), unilateral in 2 (1.71%), and no conduction and/or mixed hearing loss was encountered. Eight (6.83%) patients presented vertigo, 24 (20.51%) tinnitus. Tympanogram type A presented in 88.90% in the right ear and 91.46% in the left ear, with 5.98 to 10.25% type As. Stapedius reflex was present in 75.3 to 85.2%. Speech discrimination in the left ear was significantly different (p = 0.02)in the group older than 50 years. No association was found regarding markers of disease activity, but there was an association with the onset of rheumatoid arthritis disease. Patients with rheumatoid arthritis had a high prevalence of sensorineural hearing loss for high and very high frequencies. Copyright © 2015 Academia Mexicana de Cirugía A.C. Published by Masson Doyma México S.A. All rights reserved.

77 FR 64704 - Airworthiness Directives; The Boeing Company Airplanes

Federal Register 2010, 2011, 2012, 2013, 2014

2012-10-23

... airplanes of total loss of boost pump pressure of the fuel feed system, followed by loss of fuel system... the engine fuel suction feed capability of the fuel system, which, in the event of total loss of the... Airplanes, Attention: Data & Services Management, P. O. Box 3707, MC 2H-65, Seattle, WA 98124-2207...

J-2X Abort System Development

NASA Technical Reports Server (NTRS)

Santi, Louis M.; Butas, John P.; Aguilar, Robert B.; Sowers, Thomas S.

2008-01-01

The J-2X is an expendable liquid hydrogen (LH2)/liquid oxygen (LOX) gas generator cycle rocket engine that is currently being designed as the primary upper stage propulsion element for the new NASA Ares vehicle family. The J-2X engine will contain abort logic that functions as an integral component of the Ares vehicle abort system. This system is responsible for detecting and responding to conditions indicative of impending Loss of Mission (LOM), Loss of Vehicle (LOV), and/or catastrophic Loss of Crew (LOC) failure events. As an earth orbit ascent phase engine, the J-2X is a high power density propulsion element with non-negligible risk of fast propagation rate failures that can quickly lead to LOM, LOV, and/or LOC events. Aggressive reliability requirements for manned Ares missions and the risk of fast propagating J-2X failures dictate the need for on-engine abort condition monitoring and autonomous response capability as well as traditional abort agents such as the vehicle computer, flight crew, and ground control not located on the engine. This paper describes the baseline J-2X abort subsystem concept of operations, as well as the development process for this subsystem. A strategy that leverages heritage system experience and responds to an evolving engine design as well as J-2X specific test data to support abort system development is described. The utilization of performance and failure simulation models to support abort system sensor selection, failure detectability and discrimination studies, decision threshold definition, and abort system performance verification and validation is outlined. The basis for abort false positive and false negative performance constraints is described. Development challenges associated with information shortfalls in the design cycle, abort condition coverage and response assessment, engine-vehicle interface definition, and abort system performance verification and validation are also discussed.

Parallel Low-Loss Measurement of Multiple Atomic Qubits

NASA Astrophysics Data System (ADS)

Kwon, Minho; Ebert, Matthew F.; Walker, Thad G.; Saffman, M.

2017-11-01

We demonstrate low-loss measurement of the hyperfine ground state of rubidium atoms by state dependent fluorescence detection in a dipole trap array of five sites. The presence of atoms and their internal states are minimally altered by utilizing circularly polarized probe light and a strictly controlled quantization axis. We achieve mean state detection fidelity of 97% without correcting for imperfect state preparation or background losses, and 98.7% when corrected. After state detection and correction for background losses, the probability of atom loss due to the state measurement is <2 % and the initial hyperfine state is preserved with >98 % probability.

ADAPTIVE MONITORING TO ENHANCE WATER SENSOR CAPABILITIES FOR CHEMICAL AND BIOLOGICAL CONTAMINANT DETECTION IN DRINKING WATER SYSTEMS

EPA Science Inventory

Optoelectronic and other conventional water quality sensors offer a potential for real-time online detection of chemical and biological contaminants in a drinking water supply and distribution system. The nature of the application requires sensors of detection capabilities at lo...

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

Alonso, Jesus

Intelligent Optical Systems, Inc. has developed distributed intrinsic fiber optic sensors to directly quantify the concentration of dissolved or gas-phase CO 2 for leak detection or plume migration in carbon capture and sequestration (CCS). The capability of the sensor for highly sensitive detection of CO 2 in the pressure and temperature range of 15 to 2,000 psi and 25°C to 175°C was demonstrated, as was the capability of operating in highly corrosive and contaminated environments such as those often found in CO 2 injection sites. The novel sensor system was for the first time demonstrated deployed in a deep well,more » detecting multiple CO 2 releases, in real time, at varying depths. Early CO 2 release detection, by means of a sensor cable integrating multiple sensor segments, was demonstrated, as was the capability of quantifying the leak. The novel fiber optic sensor system exhibits capabilities not achieved by any other monitoring technology. This project represents a breakthrough in monitoring capabilities for CCS applications.« less

Mild-moderate congenital hearing loss: secular trends in outcomes across four systems of detection.

PubMed

Carew, P; Mensah, F K; Rance, G; Flynn, T; Poulakis, Z; Wake, M

2018-01-01

Universal newborn hearing screening (UNHS) targets moderate or greater hearing loss. However, UNHS also frequently detects children with mild loss that results in many receiving early treatment. The benefits of this approach are not yet established. We aimed to (i) compare language and psychosocial outcomes between four hearing loss detection systems for children aged 5-8 years with congenital mild-moderate hearing loss; (ii) determine whether age of detection predicts outcomes; and (iii) compare outcomes between children identified via well-established UNHS and the general population. Linear regression adjusted for potential confounding factors was used throughout. Via a quasi-experimental design, language and psychosocial outcomes were compared across four population-based Australian systems of hearing loss detection: opportunistic detection, born 1991-1993, n = 50; universal risk factor referral, born 2003-2005, n = 34; newly established UNHS, born 2003-2005, n = 41; and well-established UNHS, born 2007-2010, n = 21. In pooled analyses, we examined whether age of detection predicted outcomes. Outcomes were similarly compared between the current well-established UNHS system and typically developing children in the Early Language in Victoria Study, born 2003, n = 1217. Age at diagnosis and hearing aid fitting fell steadily across the four systems. For moderate losses, mean expressive language (P for trend .05) and receptive vocabulary (P for trend .06) improved across the four systems, but benefit was not obvious for mild losses. In pooled analyses, diagnosis before age six months predicted better language outcomes for moderate losses. Children with mild-moderate losses exposed to well-established UNHS continue to experience expressive language scores well below children in the general population (adjusted mean difference -8.9 points, 95% CI -14.7 to -3.1). Treatment arising from UNHS appears to be clearly benefitting children with moderate hearing losses. However, rigorous trials are needed to quantify benefits, versus costs and potential harms, of early aiding of children with mild losses. © 2017 John Wiley & Sons Ltd.

Prospective assessment of early fetal loss using an immunoenzymometric screening assay for detection of urinary human chorionic gonadotropin.

PubMed

Taylor, C A; Overstreet, J W; Samuels, S J; Boyers, S P; Canfield, R E; O'Connor, J F; Hanson, F W; Lasley, B L

1992-06-01

To develop an economical, nonradiometric immunoenzymometric assay (IEMA) for the detection of urinary human chorionic gonadotropin (hCG) in studies of early fetal loss. To be effective, the IEMA must have a sensitivity equal to the standard immunoradiometric assay (IRMA) and sufficient specificity to eliminate the need for screening most nonconceptive cycles with the expensive and labor-intensive IRMA. Two different assays were used to measure hCG in daily early morning urine samples from potential conceptive cycles. Women undergoing donor artificial insemination (AI) were evaluated in a prospective study. Ninety-two women volunteers were selected on the basis of apparent normal reproductive health. Artificial insemination with nonfrozen donor semen was performed by cervical cup twice each menstrual cycle at 48-hour intervals, and daily urine samples were self-collected throughout the menstrual cycle. An IEMA was developed to detect urinary hCG using the same antibodies as in the standard IRMA; a study was designed to determine whether this nonradiometric assay could successfully detect the early fetal loss that was detected by the IRMA. Of 224 menstrual cycles analyzed by both assays, a total of six early fetal losses were detected by the IRMA. When the tentative screening rule was set to allow all six of these losses and 95% of future losses to be detected by the IEMA, an additional 34 false-positive results were detected by the IEMA. The specificity of the IEMA with this rule was calculated to be 84%. An IEMA based on the same antibodies used for the standard IRMA can serve as an efficient screening assay for the detection of early fetal loss. When the IEMA is used in this manner, nearly 80% of screened menstrual cycles can be eliminated without further testing by the IRMA.

GPR Imaging of Prehistoric Animal Bone-beds

NASA Astrophysics Data System (ADS)

Schneider, Blair Benson

This research investigates the detection capabilities of Ground-penetrating radar for imaging prehistoric animal bone-beds. The first step of this investigation was to determine the dielectric properties of modern animal bone as a proxy for applying non-invasive ground-penetrating radar (GPR) for detecting prehistoric animal remains. Over 90 thin section samples were cut from four different modern faunal skeleton remains: bison, cow, deer, and elk. One sample of prehistoric mammoth core was also analyzed. Sample dielectric properties (relative permittivity, loss factor, and loss-tangent values) were measured with an impedance analyzer over frequencies ranging from 10 MHz to 1 GHz. The results reveal statistically significant dielectric-property differences among different animal fauna, as well as variation as a function of frequency. The measured sample permittivity values were then compared to modeled sample permittivity values using common dielectric-mixing models. The dielectric mixing models were used to report out new reported values of dry bone mineral of 3-5 in the frequency range of 10 MHz to 1 GHz. The second half of this research collected controlled GPR experiments over a sandbox containing buried bison bone elements to evaluate GPR detection capabilities of buried animal bone. The results of the controlled GPR sandbox tests were then compared to numerical models in order to predict the ability of GPR to detect buried animal bone given a variety of different depositional factors, the size and orientation of the bone target and the degree of bone weathering. The radar profiles show that GPR is an effective method for imaging the horizontal and vertical extent of buried animal bone. However, increased bone weathering and increased bone dip were both found to affect GPR reflection signal strength. Finally, the controlled sandbox experiments were also utilized to investigate the impact of survey design for imaging buried animal bone. In particular, the effects of GPR antenna orientation relative to the survey line (broad-side mode versus end-fire mode) and polarization effects of the buried bone targets were investigated. The results reveal that animal bone does exhibit polarization effects. However, the polarization results are greatly affected by the irregular shape and size of the bone, which ultimately limits the potential usefulness of trying to utilize polarization data to determine the orientation of buried bone targets. In regard to antenna orientation, end-fire mode was found to have little difference in amplitude response as compared to the more commonly used broad-side mode and in fact sometimes outperformed the broad-side mode. Future GPR investigations should consider utilizing multiple antenna orientations during data collection.

Supersensitive detection and discrimination of enantiomers by dorsal olfactory receptors: evidence for hierarchical odour coding.

PubMed

Sato, Takaaki; Kobayakawa, Reiko; Kobayakawa, Ko; Emura, Makoto; Itohara, Shigeyoshi; Kizumi, Miwako; Hamana, Hiroshi; Tsuboi, Akio; Hirono, Junzo

2015-09-11

Enantiomeric pairs of mirror-image molecular structures are difficult to resolve by instrumental analyses. The human olfactory system, however, discriminates (-)-wine lactone from its (+)-form rapidly within seconds. To gain insight into receptor coding of enantiomers, we compared behavioural detection and discrimination thresholds of wild-type mice with those of ΔD mice in which all dorsal olfactory receptors are genetically ablated. Surprisingly, wild-type mice displayed an exquisite "supersensitivity" to enantiomeric pairs of wine lactones and carvones. They were capable of supersensitive discrimination of enantiomers, consistent with their high detection sensitivity. In contrast, ΔD mice showed selective major loss of sensitivity to the (+)-enantiomers. The resulting 10(8)-fold differential sensitivity of ΔD mice to (-)- vs. (+)-wine lactone matched that observed in humans. This suggests that humans lack highly sensitive orthologous dorsal receptors for the (+)-enantiomer, similarly to ΔD mice. Moreover, ΔD mice showed >10(10)-fold reductions in enantiomer discrimination sensitivity compared to wild-type mice. ΔD mice detected one or both of the (-)- and (+)-enantiomers over a wide concentration range, but were unable to discriminate them. This "enantiomer odour discrimination paradox" indicates that the most sensitive dorsal receptors play a critical role in hierarchical odour coding for enantiomer identification.

Supersensitive detection and discrimination of enantiomers by dorsal olfactory receptors: evidence for hierarchical odour coding

PubMed Central

Sato, Takaaki; Kobayakawa, Reiko; Kobayakawa, Ko; Emura, Makoto; Itohara, Shigeyoshi; Kizumi, Miwako; Hamana, Hiroshi; Tsuboi, Akio; Hirono, Junzo

2015-01-01

Enantiomeric pairs of mirror-image molecular structures are difficult to resolve by instrumental analyses. The human olfactory system, however, discriminates (−)-wine lactone from its (+)-form rapidly within seconds. To gain insight into receptor coding of enantiomers, we compared behavioural detection and discrimination thresholds of wild-type mice with those of ΔD mice in which all dorsal olfactory receptors are genetically ablated. Surprisingly, wild-type mice displayed an exquisite “supersensitivity” to enantiomeric pairs of wine lactones and carvones. They were capable of supersensitive discrimination of enantiomers, consistent with their high detection sensitivity. In contrast, ΔD mice showed selective major loss of sensitivity to the (+)-enantiomers. The resulting 108-fold differential sensitivity of ΔD mice to (−)- vs. (+)-wine lactone matched that observed in humans. This suggests that humans lack highly sensitive orthologous dorsal receptors for the (+)-enantiomer, similarly to ΔD mice. Moreover, ΔD mice showed >1010-fold reductions in enantiomer discrimination sensitivity compared to wild-type mice. ΔD mice detected one or both of the (−)- and (+)-enantiomers over a wide concentration range, but were unable to discriminate them. This “enantiomer odour discrimination paradox” indicates that the most sensitive dorsal receptors play a critical role in hierarchical odour coding for enantiomer identification. PMID:26361056

Framework for a space shuttle main engine health monitoring system

NASA Technical Reports Server (NTRS)

Hawman, Michael W.; Galinaitis, William S.; Tulpule, Sharayu; Mattedi, Anita K.; Kamenetz, Jeffrey

1990-01-01

A framework developed for a health management system (HMS) which is directed at improving the safety of operation of the Space Shuttle Main Engine (SSME) is summarized. An emphasis was placed on near term technology through requirements to use existing SSME instrumentation and to demonstrate the HMS during SSME ground tests within five years. The HMS framework was developed through an analysis of SSME failure modes, fault detection algorithms, sensor technologies, and hardware architectures. A key feature of the HMS framework design is that a clear path from the ground test system to a flight HMS was maintained. Fault detection techniques based on time series, nonlinear regression, and clustering algorithms were developed and demonstrated on data from SSME ground test failures. The fault detection algorithms exhibited 100 percent detection of faults, had an extremely low false alarm rate, and were robust to sensor loss. These algorithms were incorporated into a hierarchical decision making strategy for overall assessment of SSME health. A preliminary design for a hardware architecture capable of supporting real time operation of the HMS functions was developed. Utilizing modular, commercial off-the-shelf components produced a reliable low cost design with the flexibility to incorporate advances in algorithm and sensor technology as they become available.

Direct Detection Electron Energy-Loss Spectroscopy: A Method to Push the Limits of Resolution and Sensitivity.

PubMed

Hart, James L; Lang, Andrew C; Leff, Asher C; Longo, Paolo; Trevor, Colin; Twesten, Ray D; Taheri, Mitra L

2017-08-15

In many cases, electron counting with direct detection sensors offers improved resolution, lower noise, and higher pixel density compared to conventional, indirect detection sensors for electron microscopy applications. Direct detection technology has previously been utilized, with great success, for imaging and diffraction, but potential advantages for spectroscopy remain unexplored. Here we compare the performance of a direct detection sensor operated in counting mode and an indirect detection sensor (scintillator/fiber-optic/CCD) for electron energy-loss spectroscopy. Clear improvements in measured detective quantum efficiency and combined energy resolution/energy field-of-view are offered by counting mode direct detection, showing promise for efficient spectrum imaging, low-dose mapping of beam-sensitive specimens, trace element analysis, and time-resolved spectroscopy. Despite the limited counting rate imposed by the readout electronics, we show that both core-loss and low-loss spectral acquisition are practical. These developments will benefit biologists, chemists, physicists, and materials scientists alike.

Real-time fluorescence loop-mediated isothermal amplification assay for direct detection of egg drop syndrome virus.

PubMed

Zheney, Makay; Kaziyev, Zhambul; Kassenova, Gulmira; Zhao, Lingna; Liu, Wei; Liang, Lin; Li, Gang

2018-02-13

Egg drop syndrome (EDS), caused by the adenovirus "egg drop syndrome virus" (EDSV) causes severe economic losses through reduced egg production in breeder and layer flocks. The diagnosis of EDSV has been done by molecular tools since its complete genome sequence was identified. In order to enhance the capabilities of the real-time fluorescence loop-mediated isothermal amplification (RealAmp) assay, we aimed to apply the method for direct detection of the EDSV without viral DNA extraction. In order to detect the presence of the EDSV DNA, three pairs of primers were designed, from the conserved region of fiber gene of the EDSV. For our assay, test and control samples were directly used in the reaction mixture in 10-fold serial dilution. The target DNA was amplified at 65 °C, which yield positive results in a relatively short period of 40-45 min. The method reported in this study is highly sensitive as compared to polymerase chain reaction (PCR) and showed no sign of cross-reactivity or false positive results. The RealAmp accomplished specific identification of EDSV among a variety of poultry disease viruses. The direct RealAmp can be used to detect the presence of EDSV. As our result showed, the RealAmp method could be suitable for the direct detection of other DNA viruses.

Antimicrobial Materials for Advanced Microbial Control in Spacecraft Water Systems

NASA Technical Reports Server (NTRS)

Birmele, Michele; Caro, Janicce; Newsham, Gerard; Roberts, Michael; Morford, Megan; Wheeler, Ray

2012-01-01

Microbial detection, identification, and control are essential for the maintenance and preservation of spacecraft water systems. Requirements set by NASA put limitations on the energy, mass, materials, noise, cost, and crew time that can be devoted to microbial control. Efforts are being made to attain real-time detection and identification of microbial contamination in microgravity environments. Research for evaluating technologies for capability enhancement on-orbit is currently focused on the use of adenosine triphosphate (ATP) analysis for detection purposes and polymerase chain reaction (peR) for microbial identification. Additional research is being conducted on how to control for microbial contamination on a continual basis. Existing microbial control methods in spacecraft utilize iodine or ionic silver biocides, physical disinfection, and point-of-use sterilization filters. Although these methods are effective, they require re-dosing due to loss of efficacy, have low human toxicity thresholds, produce poor taste, and consume valuable mass and crew time. Thus, alternative methods for microbial control are needed. This project also explores ultraviolet light-emitting diodes (UV-LEDs), surface passivation methods for maintaining residual biocide levels, and several antimicrobial materials aimed at improving current microbial control techniques, as well as addressing other materials presently under analysis and future directions to be pursued.

Species-specific multiplex PCR for the diagnosis of Brucella ovis, Actinobacillus seminis, and Histophilus somni infection in rams

PubMed Central

2013-01-01

Background Infectious ovine epididymitis results in substantial economic losses worldwide due to reproductive failure and culling of breeders. The most common causative agents of these infections are Brucella ovis, Actinobacillus seminis, and Histophilus somni. The aim of this study was to develop a multiplex PCR assay for simultaneous detection of Brucella ovis, Actinobacillus seminis, and Histophilus somni with species-specific primers applied to biological samples for molecular diagnosis of these infections. Results The multiplex assay was capable of detecting B. ovis, A. seminis, and H. somni DNA simultaneously from genomic bacterial DNA samples and pool of semen samples from experimentally infected rams. The method was highly specific since it did not amplify DNA from other bacterial species that can potentially cause epididymitis in rams as well as species phylogenetically related to B. ovis. All negative control samples were negative in PCR multiplex assay. Urine can be used as an alternative to semen samples. Conclusions The species-specific multiplex PCR assay developed in this study can be successfully used for the detection of three of the most common bacterial causes of ovine epididymitis. PMID:23514236

Listening to membrane potential: photoacoustic voltage-sensitive dye recording.

PubMed

Zhang, Haichong K; Yan, Ping; Kang, Jeeun; Abou, Diane S; Le, Hanh N D; Jha, Abhinav K; Thorek, Daniel L J; Kang, Jin U; Rahmim, Arman; Wong, Dean F; Boctor, Emad M; Loew, Leslie M

2017-04-01

Voltage-sensitive dyes (VSDs) are designed to monitor membrane potential by detecting fluorescence changes in response to neuronal or muscle electrical activity. However, fluorescence imaging is limited by depth of penetration and high scattering losses, which leads to low sensitivity in vivo systems for external detection. By contrast, photoacoustic (PA) imaging, an emerging modality, is capable of deep tissue, noninvasive imaging by combining near-infrared light excitation and ultrasound detection. Here, we show that voltage-dependent quenching of dye fluorescence leads to a reciprocal enhancement of PA intensity. We synthesized a near-infrared photoacoustic VSD (PA-VSD), whose PA intensity change is sensitive to membrane potential. In the polarized state, this cyanine-based probe enhances PA intensity while decreasing fluorescence output in a lipid vesicle membrane model. A theoretical model accounts for how the experimental PA intensity change depends on fluorescence and absorbance properties of the dye. These results not only demonstrate PA voltage sensing but also emphasize the interplay of both fluorescence and absorbance properties in the design of optimized PA probes. Together, our results demonstrate PA sensing as a potential new modality for recording and external imaging of electrophysiological and neurochemical events in the brain.

Microbial deterioration of vacuum-packaged chilled beef cuts and techniques for microbiota detection and characterization: a review.

PubMed

Hernández-Macedo, Maria Lucila; Barancelli, Giovana Verginia; Contreras-Castillo, Carmen Josefina

2011-01-01

Gas production from microbial deterioration in vacuum-packs of chilled meat leads to pack distension, which is commonly referred as blown pack. This phenomenon is attributed to some psychrophilic and psychrotrophic Clostridium species, as well as Enterobacteria. The ability of these microorganisms to grow at refrigeration temperatures makes the control by the meat industry a challenge. This type of deterioration has been reported in many countries including some plants in the Midwestern and Southeastern regions of Brazil. In addition to causing economic losses, spoilage negatively impacts the commercial product brand, thereby impairing the meat industry. In the case of strict anaerobes species they are difficult to grow and isolate using culture methods in conventional microbiology laboratories. Furthermore, conventional culture methods are sometimes not capable of distinguishing species or genera. DNA-based molecular methods are alternative strategies for detecting viable and non-cultivable microorganisms and strict anaerobic microorganisms that are difficult to cultivate. Here, we review the microorganisms and mechanisms involved in the deterioration of vacuum-packaged chilled meat and address the use of molecular methods for detecting specific strict anaerobic microorganisms and microbial communities in meat samples.

Cetacean population density estimation from single fixed sensors using passive acoustics.

PubMed

Küsel, Elizabeth T; Mellinger, David K; Thomas, Len; Marques, Tiago A; Moretti, David; Ward, Jessica

2011-06-01

Passive acoustic methods are increasingly being used to estimate animal population density. Most density estimation methods are based on estimates of the probability of detecting calls as functions of distance. Typically these are obtained using receivers capable of localizing calls or from studies of tagged animals. However, both approaches are expensive to implement. The approach described here uses a MonteCarlo model to estimate the probability of detecting calls from single sensors. The passive sonar equation is used to predict signal-to-noise ratios (SNRs) of received clicks, which are then combined with a detector characterization that predicts probability of detection as a function of SNR. Input distributions for source level, beam pattern, and whale depth are obtained from the literature. Acoustic propagation modeling is used to estimate transmission loss. Other inputs for density estimation are call rate, obtained from the literature, and false positive rate, obtained from manual analysis of a data sample. The method is applied to estimate density of Blainville's beaked whales over a 6-day period around a single hydrophone located in the Tongue of the Ocean, Bahamas. Results are consistent with those from previous analyses, which use additional tag data. © 2011 Acoustical Society of America

Listening to membrane potential: photoacoustic voltage-sensitive dye recording

NASA Astrophysics Data System (ADS)

Zhang, Haichong K.; Yan, Ping; Kang, Jeeun; Abou, Diane S.; Le, Hanh N. D.; Jha, Abhinav K.; Thorek, Daniel L. J.; Kang, Jin U.; Rahmim, Arman; Wong, Dean F.; Boctor, Emad M.; Loew, Leslie M.

2017-04-01

Voltage-sensitive dyes (VSDs) are designed to monitor membrane potential by detecting fluorescence changes in response to neuronal or muscle electrical activity. However, fluorescence imaging is limited by depth of penetration and high scattering losses, which leads to low sensitivity in vivo systems for external detection. By contrast, photoacoustic (PA) imaging, an emerging modality, is capable of deep tissue, noninvasive imaging by combining near-infrared light excitation and ultrasound detection. Here, we show that voltage-dependent quenching of dye fluorescence leads to a reciprocal enhancement of PA intensity. We synthesized a near-infrared photoacoustic VSD (PA-VSD), whose PA intensity change is sensitive to membrane potential. In the polarized state, this cyanine-based probe enhances PA intensity while decreasing fluorescence output in a lipid vesicle membrane model. A theoretical model accounts for how the experimental PA intensity change depends on fluorescence and absorbance properties of the dye. These results not only demonstrate PA voltage sensing but also emphasize the interplay of both fluorescence and absorbance properties in the design of optimized PA probes. Together, our results demonstrate PA sensing as a potential new modality for recording and external imaging of electrophysiological and neurochemical events in the brain.

Configuration of electro-optic fire source detection system

NASA Astrophysics Data System (ADS)

Fabian, Ram Z.; Steiner, Zeev; Hofman, Nir

2007-04-01

The recent fighting activities in various parts of the world have highlighted the need for accurate fire source detection on one hand and fast "sensor to shooter cycle" capabilities on the other. Both needs can be met by the SPOTLITE system which dramatically enhances the capability to rapidly engage hostile fire source with a minimum of casualties to friendly force and to innocent bystanders. Modular system design enable to meet each customer specific requirements and enable excellent future growth and upgrade potential. The design and built of a fire source detection system is governed by sets of requirements issued by the operators. This can be translated into the following design criteria: I) Long range, fast and accurate fire source detection capability. II) Different threat detection and classification capability. III) Threat investigation capability. IV) Fire source data distribution capability (Location, direction, video image, voice). V) Men portability. ) In order to meet these design criteria, an optimized concept was presented and exercised for the SPOTLITE system. Three major modular components were defined: I) Electro Optical Unit -Including FLIR camera, CCD camera, Laser Range Finder and Marker II) Electronic Unit -including system computer and electronic. III) Controller Station Unit - Including the HMI of the system. This article discusses the system's components definition and optimization processes, and also show how SPOTLITE designers successfully managed to introduce excellent solutions for other system parameters.

Presentation of computer code SPIRALI for incompressible, turbulent, plane and spiral grooved cylindrical and face seals

NASA Technical Reports Server (NTRS)

Walowit, Jed A.

1994-01-01

A viewgraph presentation is made showing the capabilities of the computer code SPIRALI. Overall capabilities of SPIRALI include: computes rotor dynamic coefficients, flow, and power loss for cylindrical and face seals; treats turbulent, laminar, Couette, and Poiseuille dominated flows; fluid inertia effects are included; rotor dynamic coefficients in three (face) or four (cylindrical) degrees of freedom; includes effects of spiral grooves; user definable transverse film geometry including circular steps and grooves; independent user definable friction factor models for rotor and stator; and user definable loss coefficients for sudden expansions and contractions.

Enhancement of the Feature Extraction Capability in Global Damage Detection Using Wavelet Theory

NASA Technical Reports Server (NTRS)

Saleeb, Atef F.; Ponnaluru, Gopi Krishna

2006-01-01

The main objective of this study is to assess the specific capabilities of the defect energy parameter technique for global damage detection developed by Saleeb and coworkers. The feature extraction is the most important capability in any damage-detection technique. Features are any parameters extracted from the processed measurement data in order to enhance damage detection. The damage feature extraction capability was studied extensively by analyzing various simulation results. The practical significance in structural health monitoring is that the detection at early stages of small-size defects is always desirable. The amount of changes in the structure's response due to these small defects was determined to show the needed level of accuracy in the experimental methods. The arrangement of fine/extensive sensor network to measure required data for the detection is an "unlimited" ability, but there is a difficulty to place extensive number of sensors on a structure. Therefore, an investigation was conducted using the measurements of coarse sensor network. The white and the pink noises, which cover most of the frequency ranges that are typically encountered in the many measuring devices used (e.g., accelerometers, strain gauges, etc.) are added to the displacements to investigate the effect of noisy measurements in the detection technique. The noisy displacements and the noisy damage parameter values are used to study the signal feature reconstruction using wavelets. The enhancement of the feature extraction capability was successfully achieved by the wavelet theory.

An Optimized Hidden Node Detection Paradigm for Improving the Coverage and Network Efficiency in Wireless Multimedia Sensor Networks

PubMed Central

Alanazi, Adwan; Elleithy, Khaled

2016-01-01

Successful transmission of online multimedia streams in wireless multimedia sensor networks (WMSNs) is a big challenge due to their limited bandwidth and power resources. The existing WSN protocols are not completely appropriate for multimedia communication. The effectiveness of WMSNs varies, and it depends on the correct location of its sensor nodes in the field. Thus, maximizing the multimedia coverage is the most important issue in the delivery of multimedia contents. The nodes in WMSNs are either static or mobile. Thus, the node connections change continuously due to the mobility in wireless multimedia communication that causes an additional energy consumption, and synchronization loss between neighboring nodes. In this paper, we introduce an Optimized Hidden Node Detection (OHND) paradigm. The OHND consists of three phases: hidden node detection, message exchange, and location detection. These three phases aim to maximize the multimedia node coverage, and improve energy efficiency, hidden node detection capacity, and packet delivery ratio. OHND helps multimedia sensor nodes to compute the directional coverage. Furthermore, an OHND is used to maintain a continuous node– continuous neighbor discovery process in order to handle the mobility of the nodes. We implement our proposed algorithms by using a network simulator (NS2). The simulation results demonstrate that nodes are capable of maintaining direct coverage and detecting hidden nodes in order to maximize coverage and multimedia node mobility. To evaluate the performance of our proposed algorithms, we compared our results with other known approaches. PMID:27618048

An Optimized Hidden Node Detection Paradigm for Improving the Coverage and Network Efficiency in Wireless Multimedia Sensor Networks.

PubMed

Alanazi, Adwan; Elleithy, Khaled

2016-09-07

Successful transmission of online multimedia streams in wireless multimedia sensor networks (WMSNs) is a big challenge due to their limited bandwidth and power resources. The existing WSN protocols are not completely appropriate for multimedia communication. The effectiveness of WMSNs varies, and it depends on the correct location of its sensor nodes in the field. Thus, maximizing the multimedia coverage is the most important issue in the delivery of multimedia contents. The nodes in WMSNs are either static or mobile. Thus, the node connections change continuously due to the mobility in wireless multimedia communication that causes an additional energy consumption, and synchronization loss between neighboring nodes. In this paper, we introduce an Optimized Hidden Node Detection (OHND) paradigm. The OHND consists of three phases: hidden node detection, message exchange, and location detection. These three phases aim to maximize the multimedia node coverage, and improve energy efficiency, hidden node detection capacity, and packet delivery ratio. OHND helps multimedia sensor nodes to compute the directional coverage. Furthermore, an OHND is used to maintain a continuous node- continuous neighbor discovery process in order to handle the mobility of the nodes. We implement our proposed algorithms by using a network simulator (NS2). The simulation results demonstrate that nodes are capable of maintaining direct coverage and detecting hidden nodes in order to maximize coverage and multimedia node mobility. To evaluate the performance of our proposed algorithms, we compared our results with other known approaches.

Failure detection of liquid cooled electronics in sealed packages. [in airborne information management system

NASA Technical Reports Server (NTRS)

Hoadley, A. W.; Porter, A. J.

1991-01-01

The theory and experimental verification of a method of detecting fluid-mass loss, expansion-chamber pressure loss, or excessive vapor build-up in NASA's Airborne Information Management System (AIMS) are presented. The primary purpose of this leak-detection method is to detect the fluid-mass loss before the volume of vapor on the liquid side causes a temperature-critical part to be out of the liquid. The method detects the initial leak after the first 2.5 pct of the liquid mass has been lost, and it can be used for detecting subsequent situations including the leaking of air into the liquid chamber and the subsequent vapor build-up.

Foliage penetration by using 4-D point cloud data

NASA Astrophysics Data System (ADS)

Méndez Rodríguez, Javier; Sánchez-Reyes, Pedro J.; Cruz-Rivera, Sol M.

2012-06-01

Real-time awareness and rapid target detection are critical for the success of military missions. New technologies capable of detecting targets concealed in forest areas are needed in order to track and identify possible threats. Currently, LAser Detection And Ranging (LADAR) systems are capable of detecting obscured targets; however, tracking capabilities are severely limited. Now, a new LADAR-derived technology is under development to generate 4-D datasets (3-D video in a point cloud format). As such, there is a new need for algorithms that are able to process data in real time. We propose an algorithm capable of removing vegetation and other objects that may obfuscate concealed targets in a real 3-D environment. The algorithm is based on wavelets and can be used as a pre-processing step in a target recognition algorithm. Applications of the algorithm in a real-time 3-D system could help make pilots aware of high risk hidden targets such as tanks and weapons, among others. We will be using a 4-D simulated point cloud data to demonstrate the capabilities of our algorithm.

A review on remotely sensed land surface temperature anomaly as an earthquake precursor

NASA Astrophysics Data System (ADS)

Bhardwaj, Anshuman; Singh, Shaktiman; Sam, Lydia; Joshi, P. K.; Bhardwaj, Akanksha; Martín-Torres, F. Javier; Kumar, Rajesh

2017-12-01

The low predictability of earthquakes and the high uncertainty associated with their forecasts make earthquakes one of the worst natural calamities, capable of causing instant loss of life and property. Here, we discuss the studies reporting the observed anomalies in the satellite-derived Land Surface Temperature (LST) before an earthquake. We compile the conclusions of these studies and evaluate the use of remotely sensed LST anomalies as precursors of earthquakes. The arrival times and the amplitudes of the anomalies vary widely, thus making it difficult to consider them as universal markers to issue earthquake warnings. Based on the randomness in the observations of these precursors, we support employing a global-scale monitoring system to detect statistically robust anomalous geophysical signals prior to earthquakes before considering them as definite precursors.

Measurement of mismatch loss in CPV modul

NASA Astrophysics Data System (ADS)

Liu, Mingguo; Kinsey, Geoffrey S.; Bagienski, Will; Nayak, Adi; Garboushian, Vahan

2012-10-01

A setup capable of simultaneously measuring I-V curves of a full string and its individual cells has been developed. This setup enables us to measure mismatch loss from individual cells in concert with various string combinations under varying field conditions. Mismatch loss from cells to plates at different off-track angles and mismatch from plates to strings in Amonix system during normal operation have been investigated.

Immunological analyses of U.S. Space Shuttle crewmembers

NASA Technical Reports Server (NTRS)

Taylor, G. R.; Neale, L. S.; Dardano, J. R.

1986-01-01

Changes in the immunoresponsiveness of 'T' lymphocytes following space flight have been reported previously. Additional data collected before and after 11 Shuttle space flights show that absolute lymphocyte numbers, lymphocyte blastogenic capability, and eosinophil percent in the peripheral blood of crewmembers are generally depressed postflight. These responses resemble those associated with physical and emotional stress and may not be related to flight per se. Additional data from Space Shuttle flights 41B and 41D, involving 11 crewmembers, indicate a postflight decrease in cells reacting with 'B' lymphocyte and monocyte monoclonal antibody tags. Further, the loss of 'T' lymphocyte blast capability correlates with the decreased monocyte count (correlation coefficient = 0.697). This finding implies that the previously reported loss of blastogenic capability may be a function of decreased monocyte control, as noted in several nonspaceflight related studies.

Socio-economic Impact Analysis for Near Real-Time Flood Detection in the Lower Mekong River Basin

NASA Astrophysics Data System (ADS)

Oddo, P.; Ahamed, A.; Bolten, J. D.

2017-12-01

Flood events pose a severe threat to communities in the Lower Mekong River Basin. The combination of population growth, urbanization, and economic development exacerbate the impacts of these flood events. Flood damage assessments are frequently used to quantify the economic losses in the wake of storms. These assessments are critical for understanding the effects of flooding on the local population, and for informing decision-makers about future risks. Remote sensing systems provide a valuable tool for monitoring flood conditions and assessing their severity more rapidly than traditional post-event evaluations. The frequency and severity of extreme flood events are projected to increase, further illustrating the need for improved flood monitoring and impact analysis. In this study we implement a socio-economic damage model into a decision support tool with near real-time flood detection capabilities (NASA's Project Mekong). Surface water extent for current and historical floods is found using multispectral Moderate-resolution Imaging Spectroradiometer (MODIS) 250-meter imagery and the spectral Normalized Difference Vegetation Index (NDVI) signatures of permanent water bodies (MOD44W). Direct and indirect damages to populations, infrastructure, and agriculture are assessed using the 2011 Southeast Asian flood as a case study. Improved land cover and flood depth assessments result in a more refined understanding of losses throughout the Mekong River Basin. Results suggest that rapid initial estimates of flood impacts can provide valuable information to governments, international agencies, and disaster responders in the wake of extreme flood events.

Feasibility study on the design of a probe for rectal cancer detection

NASA Technical Reports Server (NTRS)

Anselm, V. J.; Frazer, R. E.; Lecroisset, D. H.; Roseboro, J. A.; Smokler, M. I.

1977-01-01

Rectal examination techniques are considered in terms of detection capability, patient acceptance, and cost reduction. A review of existing clinical techniques are considered in terms of detection capability, patient acceptance, and cost reduction. A review of existing clinical techniques and of relevant aerospace technology included evaluation of the applicability of visual, thermal, ultrasound, and radioisotope modalities of examination. The desired improvements can be obtained by redesigning the proctosigmoidoscope to have reduced size, additional visibility, and the capability of readily providing a color photograph of the entire rectosigmoid mucosa in a single composite view.

Spray drift and off-target loss reduction with a precision air-assisted sprayer

USDA-ARS?s Scientific Manuscript database

Spray drift and off-target losses are inherent problems of conventional air-assisted sprayers. Their low efficiencies cause environmental pollutions resulting in public anxieties. A new drift reduction technology incorporating laser scanning capabilities with a variable-rate air-assisted sprayer w...

Insect-gene-activity detection system for chemical and biological warfare agents and toxic industrial chemicals

NASA Astrophysics Data System (ADS)

Mackie, Ryan S.; Schilling, Amanda S.; Lopez, Arturo M.; Rayms-Keller, Alfredo

2002-02-01

Detection of multiple chemical and biological weapons (CBW) agents and/or complex mixtures of toxic industrial chemicals (TIC) is imperative for both the commercial and military sectors. In a military scenario, a multi-CBW attack would create confusion, thereby delaying decontamination and therapeutic efforts. In the commercial sector, polluted sites invariably contain a mixture of TIC. Novel detection systems capable of detecting CBW and TIC are sorely needed. While it may be impossible to build a detector capable of discriminating all the possible combinations of CBW, a detection system capable of statistically predicting the most likely composition of a given mixture is within the reach of current emerging technologies. Aquatic insect-gene activity may prove to be a sensitive, discriminating, and elegant paradigm for the detection of CBW and TIC. We propose to systematically establish the expression patterns of selected protein markers in insects exposed to specific mixtures of chemical and biological warfare agents to generate a library of biosignatures of exposure. The predicting capabilities of an operational library of biosignatures of exposures will allow the detection of emerging novel or genetically engineered agents, as well as complex mixtures of chemical and biological weapons agents. CBW and TIC are discussed in the context of war, terrorism, and pollution.

Detection and isolation of nucleic acid sequences using a bifunctional hybridization probe

DOEpatents

Lucas, Joe N.; Straume, Tore; Bogen, Kenneth T.

2000-01-01

A method for detecting and isolating a target sequence in a sample of nucleic acids is provided using a bifunctional hybridization probe capable of hybridizing to the target sequence that includes a detectable marker and a first complexing agent capable of forming a binding pair with a second complexing agent. A kit is also provided for detecting a target sequence in a sample of nucleic acids using a bifunctional hybridization probe according to this method.

Matched filter based detection of floating mines in IR spacetime

NASA Astrophysics Data System (ADS)

Borghgraef, Alexander; Lapierre, Fabian; Philips, Wilfried; Acheroy, Marc

2009-09-01

Ship-based automatic detection of small floating objects on an agitated sea surface remains a hard problem. Our main concern is the detection of floating mines, which proved a real threat to shipping in confined waterways during the first Gulf War, but applications include salvaging,search-and-rescue and perimeter or harbour defense. IR video was chosen for its day-and-night imaging capability, and its availability on military vessels. Detection is difficult because a rough sea is seen as a dynamic background of moving objects with size order, shape and temperature similar to those of the floating mine. We do find a determinant characteristic in the target's periodic motion, which differs from that of the propagating surface waves composing the background. The classical detection and tracking approaches give bad results when applied to this problem. While background detection algorithms assume a quasi-static background, the sea surface is actually very dynamic, causing this category of algorithms to fail. Kalman or particle filter algorithms on the other hand, which stress temporal coherence, suffer from tracking loss due to occlusions and the great noise level of the image. We propose an innovative approach. This approach uses the periodicity of the objects movement and thus its temporal coherence. The principle is to consider the video data as a spacetime volume similar to a hyperspectral data cube by replacing the spectral axis with a temporal axis. We can then apply algorithms developed for hyperspectral detection problems to the detection of small floating objects. We treat the detection problem using multilinear algebra, designing a number of finite impulse response filters (FIR) maximizing the target response. The algorithm was applied to test footage of practice mines in the infrared.

Deep Learning for Real-Time Capable Object Detection and Localization on Mobile Platforms

NASA Astrophysics Data System (ADS)

Particke, F.; Kolbenschlag, R.; Hiller, M.; Patiño-Studencki, L.; Thielecke, J.

2017-10-01

Industry 4.0 is one of the most formative terms in current times. Subject of research are particularly smart and autonomous mobile platforms, which enormously lighten the workload and optimize production processes. In order to interact with humans, the platforms need an in-depth knowledge of the environment. Hence, it is required to detect a variety of static and non-static objects. Goal of this paper is to propose an accurate and real-time capable object detection and localization approach for the use on mobile platforms. A method is introduced to use the powerful detection capabilities of a neural network for the localization of objects. Therefore, detection information of a neural network is combined with depth information from a RGB-D camera, which is mounted on a mobile platform. As detection network, YOLO Version 2 (YOLOv2) is used on a mobile robot. In order to find the detected object in the depth image, the bounding boxes, predicted by YOLOv2, are mapped to the corresponding regions in the depth image. This provides a powerful and extremely fast approach for establishing a real-time-capable Object Locator. In the evaluation part, the localization approach turns out to be very accurate. Nevertheless, it is dependent on the detected object itself and some additional parameters, which are analysed in this paper.

Low-loss adiabatically-tapered high-contrast gratings for slow-wave modulators on SOI

NASA Astrophysics Data System (ADS)

Sciancalepore, Corrado; Hassan, Karim; Ferrotti, Thomas; Harduin, Julie; Duprez, Hélène; Menezo, Sylvie; Ben Bakir, Badhise

2015-02-01

In this communication, we report about the design, fabrication, and testing of Silicon-based photonic integrated circuits (Si-PICs) including low-loss flat-band slow-light high-contrast-gratings (HCGs) waveguides at 1.31 μm. The light slowdown is achieved in 300-nm-thick silicon-on-insulator (SOI) rib waveguides by patterning adiabatically-tapered highcontrast gratings, capable of providing slow-light propagation with extremely low optical losses, back-scattering, and Fabry-Pérot noise. In detail, the one-dimensional (1-D) grating architecture is capable to provide band-edge group indices ng ~ 25, characterized by overall propagation losses equivalent to those of the index-like propagation regime (~ 1-2 dB/cm). Such photonic band-edge slow-light regime at low propagation losses is made possible by the adiabatic apodization of such 1-D HCGs, thus resulting in a win-win approach where light slow-down regime is reached without additional optical losses penalty. As well as that, a tailored apodization optimized via genetic algorithms allows the flattening of slow-light regime over the wavelength window of interest, therefore suiting well needs for group index stability for modulation purposes and non-linear effects generation. In conclusion, such architectures provide key features suitable for power-efficient high-speed modulators in silicon as well as an extremely low-loss building block for non-linear optics (NLO) which is now available in the Si photonics toolbox.

Comparative study of three screening tests, two microbiological tube tests, and a multi-sulphonamide ELISA kit for the detection of antimicrobial and sulphonamide residues in eggs.

PubMed

Gaudin, V; Hedou, C; Rault, A; Sanders, P; Verdon, E

2009-04-01

The screening of antimicrobial residues in eggs is an especially important subject. Three different commercial kits for the screening of sulphonamides and other antimicrobials in eggs were validated in accordance with Decision 2002/657/EC: one enzyme-linked immunoabsorbant assay (ELISA) kit multi-sulphonamides (from RAISIO Diagnostics) and two microbiological tests (a Premi test from DSM and an Explorer kit from Zeu-Inmunotec). The false-positive rates were lower than 2% for all kits. The detection capabilities (CCbeta) have to be as low as possible for banned substances and lower than the maximum residue limit (MRL) when MRLs have been set. The sensitivity of the Premi test was better than that of the Explorer test, probably because of the dilution of the eggs before the Explorer test was used. The CCbeta values towards most of the tested sulphonamides were satisfactory with the Premi test (< or = 100 microg kg(-1)). Performance in a proficiency test for the detection of sulphonamides in eggs with the Premi test confirmed these results. The detection capabilities of tetracycline and doxycycline were at the level of the MRL or twice the MRL maximum. The detection capabilities for chlortetracycline and oxytetracycline were higher (four to six times the MRL). The detection capabilities for amoxicillin, neomycin, tylosin and erythromycin were lower than their respective MRLs. Detection capabilities for sulphonamides were much lower for the ELISA kit than for microbiological tests. The ELISA kit could be recommended for the targeted screening of sulphonamides in eggs. On the other hand, the Explorer and Premi tests could be used as wide screening tests allowing the detection of most of the antimicrobial families.

Cold-evoked potentials - Ready for clinical use?

PubMed

Hüllemann, P; Nerdal, A; Binder, A; Helfert, S; Reimer, M; Baron, R

2016-11-01

Cold-evoked potentials (CEPs) are known to assess the integrity of A-delta fibres and the spinothalamic tract. Nevertheless, the clinical value was not investigated previously. The aim of this study was to measure CEPs in 16 healthy subjects from the face, hand and foot sole and to investigate whether CEPs reliably detect A-delta fibre abnormalities. Swift cold stimuli were applied to the skin with a commercially available thermode, which cooled down from 30 to 25 °C in approximately 0.5 s. CEP latencies (N1, N2 and P2) and amplitudes (N1, N2/P2) were recorded with EEG. Reversible A-fibre function loss was induced by applying a selective A-fibre block at the superficial radial nerve. In all 16 subjects CEPs could be recorded from all locations; N2, P2 mean latencies were 276.4 ± 38.9 and 389.8 ± 52.5 (face), 318.6 ± 31.6 ms and 477.7 ± 43.6 (hand), and 627.6 ± 84.4 and 774.2 ± 94.0 (foot sole). N2/P2 amplitudes were 10.7 ± 4.1, 11.3 ± 4.1 and 7.5 ± 4.1 μV. During A-fibre block no CEPs were detectable in the grand average, which restored 10 min after block removal. CEPs were reliably recorded in healthy subjects at the hand, face and foot. Experimentally induced reversible A-delta fibre function loss was detected by CEPs. Functional recovery was assessed as well. This study is basis for further CEP evaluation studies and might be the first step for implementing CEPs in clinical routine for the early diagnosis of small-fibre disease. WHAT DOES THIS STUDY ADD?: Cold-evoked potentials are capable of reliably measuring A-delta fibre integrity, loss of function and functional recovery in healthy subjects, which is an essential prerequisite for diagnostic use in patients with small-fibre disease. © 2016 European Pain Federation - EFIC®.

7 CFR 1437.104 - Assigned production.

Code of Federal Regulations, 2010 CFR

2010-01-01

...) Irrigation equipment is not capable of supplying adequate water to sustain the expected production of a... practice is not used. (7) For normal irrigated annual and biennial crops, the supply of available water at... determining losses under this section, assigned production will be used to offset the loss of production when...

Turbomachinery Heat Transfer and Loss Modeling for 3D Navier-Stokes Codes

NASA Technical Reports Server (NTRS)

DeWitt, Kenneth; Ameri, Ali

2005-01-01

This report's contents focus on making use of NASA Glenn on-site computational facilities,to develop, validate, and apply models for use in advanced 3D Navier-Stokes Computational Fluid Dynamics (CFD) codes to enhance the capability to compute heat transfer and losses in turbomachiney.

Discriminating a Single Nucleotide Difference for Enhanced miRNA Detection Using Tunable Graphene and Oligonucleotide Nanodevices.

PubMed

Robertson, Neil M; Hizir, Mustafa Salih; Balcioglu, Mustafa; Wang, Rui; Yavuz, Mustafa Selman; Yumak, Hasan; Ozturk, Birol; Sheng, Jia; Yigit, Mehmet V

2015-09-15

In this study we have reported our efforts to address some of the challenges in the detection of miRNAs using water-soluble graphene oxide and DNA nanoassemblies. Purposefully inserting mismatches at specific positions in our DNA (probe) strands shows increasing specificity against our target miRNA, miR-10b, over miR-10a which varies by only a single nucleotide. This increased specificity came at a loss of signal intensity within the system, but we demonstrated that this could be addressed with the use of DNase I, an endonuclease capable of cleaving the DNA strands of the RNA/DNA heteroduplex and recycling the RNA target to hybridize to another probe strand. As we previously demonstrated, this enzymatic signal also comes with an inherent activity of the enzyme on the surface-adsorbed probe strands. To remove this activity of DNase I and the steady nonspecific increase in the fluorescence signal without compromising the recovered signal, we attached a thermoresponsive PEGMA polymer (poly(ethylene glycol) methyl ether methacrylate) to nGO. This smart polymer is able to shield the probes adsorbed on the nGO surface from the DNase I activity and is capable of tuning the detection capacity of the nGO nanoassembly with a thermoswitch at 39 °C. By utilizing probes with multiple mismatches, DNase I cleavage of the DNA probe strands, and the attachment of PEGMA polymers to graphene oxide to block undesired DNase I activity, we were able to detect miR-10b from liquid biopsy mimics and breast cancer cell lines. Overall we have reported our efforts to improve the specificity, increase the sensitivity, and eliminate the undesired enzymatic activity of DNase I on surface-adsorbed probes for miR-10b detection using water-soluble graphene nanodevices. Even though we have demonstrated only the discrimination of miR-10b from miR-10a, our approach can be extended to other short RNA molecules which differ by a single nucleotide.

Micro-Spec: an Integrated, Direct-Detection Spectrometer for Far-Infrared and Sub-Millimeter Astronomy

NASA Astrophysics Data System (ADS)

Cataldo, Giuseppe; Moseley, S. H.; Hsieh, W.; Huang, W.; Stevenson, T.; Wollack, E.

2014-01-01

Many space-based observatories, such as Spitzer and Herschel, have opened the far-infrared (IR) window to the universe, revealing rich line and continuum spectra from objects ranging from interplanetary dust particles to galactic mergers and young galaxies in the early universe. Micro-Spec (µ-Spec) is proposed as a novel technology concept to enable new discoveries in the far-IR spectral range. µ-Spec will be a high-sensitivity, direct-detection spectrometer operating in the 450-1000 µm regime. It will have two antenna arrays, one for transmitting and one for receiving, and superconducting microstrip transmission lines for power division and phase delay. Using superconducting materials reduces losses at a minimum, thereby providing background-limited sensitivity (noise equivalent power, NEP, less than 3x10^-21 W/√Hz) at a resolution 1200, potentially making µ-Spec four orders of magnitude more sensitive than its most capable predecessors. Materials being investigated for the development of the instrument transmission line and detectors include niobium and niobium-titanium nitride for the former, and molybdenum nitride for the latter. In addition, the instrument will be integrated on a four-inch-diameter silicon chip. Such a dramatic size reduction is made possible by the fact that silicon has a refraction index three times that of vacuum, thereby allowing the transmission lines to be shorter than in vacuum by a factor of three. For all these reasons, µ-Spec can become an important capability under the low background conditions provided by space telescopes such as the space infrared telescope for cosmology and astrophysics SPICA, possible Explorers and cryogenically-cooled balloons. The discussion will illustrate a point design developed for initial demonstration with a 30% efficiency due to losses to other diffraction orders. Design variations on this implementation will be shown that lead to near-unity efficiency and will be the basis of future instruments. Models to analyze the properties of the superconductors will also be described along with transmission data used to test and validate the models.

An analytical method to predict efficiency of aircraft gearboxes

NASA Technical Reports Server (NTRS)

Anderson, N. E.; Loewenthal, S. H.; Black, J. D.

1984-01-01

A spur gear efficiency prediction method previously developed by the authors was extended to include power loss of planetary gearsets. A friction coefficient model was developed for MIL-L-7808 oil based on disc machine data. This combined with the recent capability of predicting losses in spur gears of nonstandard proportions allows the calculation of power loss for complete aircraft gearboxes that utilize spur gears. The method was applied to the T56/501 turboprop gearbox and compared with measured test data. Bearing losses were calculated with large scale computer programs. Breakdowns of the gearbox losses point out areas for possible improvement.

Early Identification of Herbicide Stress in Soybean (Glycine max (L.) Merr.) Using Chlorophyll Fluorescence Imaging Technology

PubMed Central

Li, Hui; Wang, Pei; Weber, Jonas Felix; Gerhards, Roland

2017-01-01

Herbicides may damage soybean in conventional production systems. Chlorophyll fluorescence imaging technology has been applied to identify herbicide stress in weed species a few days after application. In this study, greenhouse experiments followed by field experiments at five sites were conducted to investigate if the chlorophyll fluorescence imaging is capable of identifying herbicide stress in soybean shortly after application. Measurements were carried out from emergence until the three-to-four-leaf stage of the soybean plants. Results showed that maximal photosystem II (PS II) quantum yield and shoot dry biomass was significantly reduced in soybean by herbicides compared to the untreated control plants. The stress of PS II inhibiting herbicides occurred on the cotyledons of soybean and plants recovered after one week. The stress induced by DOXP synthase-, microtubule assembly-, or cell division-inhibitors was measured from the two-leaf stage until four-leaf stage of soybean. We could demonstrate that the chlorophyll fluorescence imaging technology is capable for detecting herbicide stress in soybean. The system can be applied under both greenhouse and field conditions. This helps farmers to select weed control strategies with less phytotoxicity in soybean and avoid yield losses due to herbicide stress. PMID:29271905

Early Identification of Herbicide Stress in Soybean (Glycine max (L.) Merr.) Using Chlorophyll Fluorescence Imaging Technology.

PubMed

Li, Hui; Wang, Pei; Weber, Jonas Felix; Gerhards, Roland

2017-12-22

Herbicides may damage soybean in conventional production systems. Chlorophyll fluorescence imaging technology has been applied to identify herbicide stress in weed species a few days after application. In this study, greenhouse experiments followed by field experiments at five sites were conducted to investigate if the chlorophyll fluorescence imaging is capable of identifying herbicide stress in soybean shortly after application. Measurements were carried out from emergence until the three-to-four-leaf stage of the soybean plants. Results showed that maximal photosystem II (PS II) quantum yield and shoot dry biomass was significantly reduced in soybean by herbicides compared to the untreated control plants. The stress of PS II inhibiting herbicides occurred on the cotyledons of soybean and plants recovered after one week. The stress induced by DOXP synthase-, microtubule assembly-, or cell division-inhibitors was measured from the two-leaf stage until four-leaf stage of soybean. We could demonstrate that the chlorophyll fluorescence imaging technology is capable for detecting herbicide stress in soybean. The system can be applied under both greenhouse and field conditions. This helps farmers to select weed control strategies with less phytotoxicity in soybean and avoid yield losses due to herbicide stress.

Fate dynamics of environmentally exposed explosive traces.

PubMed

Kunz, Roderick R; Gregory, Kerin E; Aernecke, Matthew J; Clark, Michelle L; Ostrinskaya, Alla; Fountain, Augustus W

2012-04-12

The chemical and physical fates of trace amounts (<50 μg) of explosives containing 2,4,6-trinitrotoluene (TNT), hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), and pentaerythritol tetranitrate (PETN) were determined for the purpose of informing the capabilities of tactical trace explosive detection systems. From these measurements, it was found that the mass decreases and the chemical composition changes on a time scale of hours, with the loss mechanism due to a combination of sublimation and photodegradation. The rates for these processes were dependent on the explosive composition, as well as on both the ambient temperature and the size distribution of the explosive particulates. From these results, a persistence model was developed and applied to model the time dependence of both the mass and areal coverage of the fingerprints, resulting in a predictive capability for determining fingerprint fate. Chemical analysis confirmed that sublimation rates for TNT were depressed by UV (330-400 nm) exposure due to photochemically driven increases in the molecular weight, whereas the opposite was observed for RDX. No changes were observed for PETN upon exposure to UV radiation, and this was attributed to its low UV absorbance.

Pediatric tinnitus: Incidence of imaging anomalies and the impact of hearing loss.

PubMed

Kerr, Rhorie; Kang, Elise; Hopkins, Brandon; Anne, Samantha

2017-12-01

Guidelines exist for evaluation and management of tinnitus in adults; however lack of evidence in children limits applicability of these guidelines to pediatric patients. Objective of this study is to determine the incidence of inner ear anomalies detected on imaging studies within the pediatric population with tinnitus and evaluate if presence of hearing loss increases the rate of detection of anomalies in comparison to normal hearing patients. Retrospective review of all children with diagnosis of tinnitus from 2010 to 2015 ;at a tertiary care academic center. 102 pediatric patients with tinnitus were identified. Overall, 53 patients had imaging studies with 6 abnormal findings (11.3%). 51/102 patients had hearing loss of which 33 had imaging studies demonstrating 6 inner ear anomalies detected. This is an incidence of 18.2% for inner ear anomalies identified in patients with hearing loss (95% confidence interval (CI) of 7.0-35.5%). 4 of these 6 inner ear anomalies detected were vestibular aqueduct abnormalities. The other two anomalies were cochlear hypoplasia and bilateral semicircular canal dysmorphism. 51 patients had no hearing loss and of these patients, 20 had imaging studies with no inner ear abnormalities detected. There was no statistical difference in incidence of abnormal imaging findings in patients with and without hearing loss (Fisher's exact test, p ;= ;0.072.) CONCLUSION: There is a high incidence of anomalies detected in imaging studies done in pediatric patients with tinnitus, especially in the presence of hearing loss. Copyright © 2017 Elsevier B.V. All rights reserved.

A statistical method (cross-validation) for bone loss region detection after spaceflight

PubMed Central

Zhao, Qian; Li, Wenjun; Li, Caixia; Chu, Philip W.; Kornak, John; Lang, Thomas F.

2010-01-01

Astronauts experience bone loss after the long spaceflight missions. Identifying specific regions that undergo the greatest losses (e.g. the proximal femur) could reveal information about the processes of bone loss in disuse and disease. Methods for detecting such regions, however, remains an open problem. This paper focuses on statistical methods to detect such regions. We perform statistical parametric mapping to get t-maps of changes in images, and propose a new cross-validation method to select an optimum suprathreshold for forming clusters of pixels. Once these candidate clusters are formed, we use permutation testing of longitudinal labels to derive significant changes. PMID:20632144

Late diagenetic indicators of buried oil and gas: II, Direct detection experiment at Cement and Garza oil fields, Oklahoma and Texas, using enhanced LANDSAT I and II images

USGS Publications Warehouse

Donovan, Terrence J.; Termain, Patricia A.; Henry, Mitchell E.

1979-01-01

The Cement oil field, Oklahoma, was a test site for an experiment designed to evaluate LANDSAT's capability to detect an alteration zone in surface rocks caused by hydrocarbon microseepage. Loss of iron and impregnation of sandstone by carbonate cements and replacement of gypsum by calcite are the major alteration phenomena at Cement. The bedrock alterations are partially masked by unaltered overlying beds, thick soils, and dense natural and cultivated vegetation. Interpreters biased by detailed ground truth were able to map the alteration zone subjectively using a magnified, filtered, and sinusoidally stretched LANDSAT composite image; other interpreters, unbiased by ground truth data, could not duplicate that interpretation. Similar techniques were applied at a secondary test site (Garza oil field, Texas), where similar alterations in surface rocks occur. Enhanced LANDSAT images resolved the alteration zone to a biased interpreter and some individual altered outcrops could be mapped using higher resolution SKYLAB color and conventional black and white aerial photographs suggesting repeat experiments with LANDSAT C and D.

Algorithmic network monitoring for a modern water utility: a case study in Jerusalem.

PubMed

Armon, A; Gutner, S; Rosenberg, A; Scolnicov, H

2011-01-01

We report on the design, deployment, and use of TaKaDu, a real-time algorithmic Water Infrastructure Monitoring solution, with a strong focus on water loss reduction and control. TaKaDu is provided as a commercial service to several customers worldwide. It has been in use at HaGihon, the Jerusalem utility, since mid 2009. Water utilities collect considerable real-time data from their networks, e.g. by means of a SCADA system and sensors measuring flow, pressure, and other data. We discuss how an algorithmic statistical solution analyses this wealth of raw data, flexibly using many types of input and picking out and reporting significant events and failures in the network. Of particular interest to most water utilities is the early detection capability for invisible leaks, also a means for preventing large visible bursts. The system also detects sensor and SCADA failures, various water quality issues, DMA boundary breaches, unrecorded or unintended network changes (like a valve or pump state change), and other events, including types unforeseen during system design. We discuss results from use at HaGihon, showing clear operational value.

Is nothing sacred?

USGS Publications Warehouse

Hoffman, G.L.

1980-01-01

N-sodium-N-chloro-rho-toluenesulfonamide (chloramine-T) effectively controls bacterial gill disease (BGD) in cultured fishes, BGD, a common disease of hatchery-reared salmonids, causes more fish losses than any other disease among these species, This study describes a liquid chromatographic (LC) method that is capable of direct, simultaneous analysis of chloramine-T and its primary degradation product, rho-toluenesulfonamide (rho-TSA), in water. The procedure involves reversed-phase (C-18) LC analysis with ion suppression, using 0.01 M phosphate buffer at pH 3. The mobile phase is phosphate buffer-acetonitrile (60 + 40) at 1 mL/min. Both chemicals can be detected with a UV spectrophotometer at 229 nm; the method is linear up to 40 mg, chloramine-T or rho-TSA/L. Mean recoveries were 96.4 +/- 6.1% for water samples fortified with 0.03 mg chloramine-T/L and 95.3 +/- 4.6% for water samples fortified with 0.005 mg rho-TSA/L. Limits of detection without sample enrichment for chloramine-T and rho-TSA are 0.01 mg/L and 0.001 mg/L, respectively.

Liquid chromatographic determination of chloramine-T and its primary degradation product, p-toluenesulfonamide, in water

USGS Publications Warehouse

Dawson, Verdel K.; Davis, Ruth A.

1997-01-01

N-sodium-N-chloro-rho-toluenesulfonamide (chloramine-T) effectively controls bacterial gill disease (BGD) in cultured fishes, BGD, a common disease of hatchery-reared salmonids, causes more fish losses than any other disease among these species. This study describes a liquid chromatographic (LC) method that is capable of direct, simultaneous analysis of chloramine-T and its primary degradation product, rho-toluenesulfonamide (rho-TSA), in water. The procedure involves reversed-phase (C-18) LC analysis with ion suppression, using 0.01 M phosphate buffer at pH 3. The mobile phase is phosphate buffer-acetonitrile (60 + 40) at 1 mL/min. Both chemicals can be detected with a UV spectrophotometer at 229 nm; the method is linear up to 40 mg, chloramine-T or rho-TSA/L. Mean recoveries were 96.4 +/- 6.1% for water samples fortified with 0.03 mg chloramine-T/L and 95.3 +/- 4.6% for water samples fortified with 0.005 mg rho-TSA/L. Limits of detection without sample enrichment for chloramine-T and rho-TSA are 0.01 mg/L and 0.001 mg/L, respectively.

Liquid chromatographic determination of chloramine-T and its primary degradation product, p-toluenesulfonamide, in water

USGS Publications Warehouse

Dawson, V.K.; Davis, R.A.

1997-01-01

N-sodium-N-chloro-rho-toluenesulfonamide (chloramine-T) effectively controls bacterial gill disease (BGD) in cultured fishes, BGD, a common disease of hatchery-reared salmonids, causes more fish losses than any other disease among these species, This study describes a liquid chromatographic (LC) method that is capable of direct, simultaneous analysis of chloramine-T and its primary degradation product, rho-toluenesulfonamide (rho-TSA), in water. The procedure involves reversed-phase (C-18) LC analysis with ion suppression, using 0.01 M phosphate buffer at pH 3. The mobile phase is phosphate buffer-acetonitrile (60 + 40) at 1 mL/min. Both chemicals can be detected with a UV spectrophotometer at 229 nm; the method is linear up to 40 mg, chloramine-T or rho-TSA/L. Mean recoveries were 96.4 +/- 6.1% for water samples fortified with 0.03 mg chloramine-T/L and 95.3 +/- 4.6% for water samples fortified with 0.005 mg rho-TSA/L. Limits of detection without sample enrichment for chloramine-T and rho-TSA are 0.01 mg/L and 0.001 mg/L, respectively.

Electronic drop sensing in microfluidic devices: automated operation of a nanoliter viscometer

PubMed Central

Srivastava, Nimisha; Burns, Mark A.

2007-01-01

We describe three droplet sensing techniques: a digital electrode, an analog electrode, and a thermal method. All three techniques use a single layer of metal lines that is easy to microfabricate and an electronic signal can be produced using low DC voltages. While the electrode methods utilize changes in electrical conductivity when the air/liquid interface of the droplet passes over a pair of electrodes, the thermal method is based on convective heat loss from a locally heated region. For the electrode method, the analog technique is able to detect 25 nL droplets while the digital technique is capable of detecting droplets as small as 100 pL. For thermal sensing, temperature profiles in the range of 36 °C and higher were used. Finally, we have used the digital electrode method and an array of electrodes located at preset distances to automate the operation of a previously described microfluidic viscometer. The viscometer is completely controlled by a laptop computer, and the total time for operation including setup, calibration, sample addition and viscosity calculation is approximately 4 minutes. PMID:16738725

Distributed Fault-Tolerant Control of Networked Uncertain Euler-Lagrange Systems Under Actuator Faults.

PubMed

Chen, Gang; Song, Yongduan; Lewis, Frank L

2016-05-03

This paper investigates the distributed fault-tolerant control problem of networked Euler-Lagrange systems with actuator and communication link faults. An adaptive fault-tolerant cooperative control scheme is proposed to achieve the coordinated tracking control of networked uncertain Lagrange systems on a general directed communication topology, which contains a spanning tree with the root node being the active target system. The proposed algorithm is capable of compensating for the actuator bias fault, the partial loss of effectiveness actuation fault, the communication link fault, the model uncertainty, and the external disturbance simultaneously. The control scheme does not use any fault detection and isolation mechanism to detect, separate, and identify the actuator faults online, which largely reduces the online computation and expedites the responsiveness of the controller. To validate the effectiveness of the proposed method, a test-bed of multiple robot-arm cooperative control system is developed for real-time verification. Experiments on the networked robot-arms are conduced and the results confirm the benefits and the effectiveness of the proposed distributed fault-tolerant control algorithms.

Detection of water in jet fuel using layer-by-layer thin film coated long period grating sensor.

PubMed

Puckett, Sean D; Pacey, Gilbert E

2009-04-15

The quantitative measurement of jet fuel additives in the field is of interest to the Air Force. The "smart nozzle" project was designed as a state-of-the-art diagnostics package attached to a single-point refueling nozzle for assessing key fuel properties as the fuel is dispensed. The objective of the work was to show proof of concept that a layer-by-layer thin film and long period grating fibers could be used to detect the presence of water in jet fuel. The data for the nafion/PDMA film and a long period grating fiber is a combination capable of quantitative measurement of water in kerosene. The average response (spectral loss wavelength shift) to the kerosene sample ranged from -6.0 for 15 ppm to -126.5 for 60 ppm water. The average calculated value for the check standard was 21.71 and ranged from 21.25 to 22.00 with a true value of 22.5 ppm water. Potential interferences were observed and are judged to be insignificant in real samples.

Poor sequestration of toxic host plant cardenolides and their rapid loss in the milkweed butterfly Danaus chrysippus (Lepidoptera: Nymphalidae: Danainae: Danaini).

PubMed

Mebs, Dietrich; Wunder, Cora; Toennes, Stefan W

2017-06-01

Butterflies of the genus Danaus are known to sequester toxic cardenolides from milkweed host plants (Apocynaceae). In particular, Danaus plexippus efficiently sequesters and stores these compounds, whereas D. chrysippus, is considered to poorly sequester cardenolides. To estimate its sequestration capability compared with that of D. plexippus, larvae of both species were jointly reared on Asclepias curassavica and the major cardenolides of the host plant, calotropin and calactin, were analyzed in adults sampled at different time intervals after eclosion. Both cardenolides were detected in body and wings of D. plexippus. Whereas the calotropin-concentration remained constant over a period of 24 days, that of calactin steadily decreased. In the body, but not in the wings of D. chrysippus, calactin only was detected in low amounts, which was then almost completely lost during the following 8 days after eclosion, suggesting that in contrast to D. plexippus, cardenolides seem to be less important for that butterfly's defence against predators. Copyright © 2017 Elsevier Ltd. All rights reserved.

Directed Design of Experiments for Validating Probability of Detection Capability of NDE Systems (DOEPOD)

NASA Technical Reports Server (NTRS)

Generazio, Edward R.

2015-01-01

Directed Design of Experiments for Validating Probability of Detection Capability of NDE Systems (DOEPOD) Manual v.1.2 The capability of an inspection system is established by applications of various methodologies to determine the probability of detection (POD). One accepted metric of an adequate inspection system is that there is 95% confidence that the POD is greater than 90% (90/95 POD). Design of experiments for validating probability of detection capability of nondestructive evaluation (NDE) systems (DOEPOD) is a methodology that is implemented via software to serve as a diagnostic tool providing detailed analysis of POD test data, guidance on establishing data distribution requirements, and resolving test issues. DOEPOD demands utilization of observance of occurrences. The DOEPOD capability has been developed to provide an efficient and accurate methodology that yields observed POD and confidence bounds for both Hit-Miss or signal amplitude testing. DOEPOD does not assume prescribed POD logarithmic or similar functions with assumed adequacy over a wide range of flaw sizes and inspection system technologies, so that multi-parameter curve fitting or model optimization approaches to generate a POD curve are not required. DOEPOD applications for supporting inspector qualifications is included.

Behavioral manifestations of audiometrically-defined "slight" or "hidden" hearing loss revealed by measures of binaural detection.

PubMed

Bernstein, Leslie R; Trahiotis, Constantine

2016-11-01

This study assessed whether audiometrically-defined "slight" or "hidden" hearing losses might be associated with degradations in binaural processing as measured in binaural detection experiments employing interaurally delayed signals and maskers. Thirty-one listeners participated, all having no greater than slight hearing losses (i.e., no thresholds greater than 25 dB HL). Across the 31 listeners and consistent with the findings of Bernstein and Trahiotis [(2015). J. Acoust. Soc. Am. 138, EL474-EL479] binaural detection thresholds at 500 Hz and 4 kHz increased with increasing magnitude of interaural delay, suggesting a loss of precision of coding with magnitude of interaural delay. Binaural detection thresholds were consistently found to be elevated for listeners whose absolute thresholds at 4 kHz exceeded 7.5 dB HL. No such elevations were observed in conditions having no binaural cues available to aid detection (i.e., "monaural" conditions). Partitioning and analyses of the data revealed that those elevated thresholds (1) were more attributable to hearing level than to age and (2) result from increased levels of internal noise. The data suggest that listeners whose high-frequency monaural hearing status would be classified audiometrically as being normal or "slight loss" may exhibit substantial and perceptually meaningful losses of binaural processing.

Prevalence and viability of group A rotavirus in dairy farm water sources.

PubMed

Castells, M; Schild, C; Caffarena, D; Bok, M; Giannitti, F; Armendano, J; Riet-Correa, F; Victoria, M; Parreño, V; Colina, R

2018-03-01

To analyse group A rotavirus (RVA) environmental contamination in waters used for calves' consumption and to assess viral viability in dairy farm water sources. We analysed 202 samples of water used for calves' consumption and RVA was detected by RT-qPCR in 35·1% (95% CI: 28·9-42·0%). A marked pattern of seasonality was observed with higher frequency of detection in colder than warmer months (P = 0·002). There was no association between viral load and season or between the number of milking cows in the herd and the detection of RVA in the farm. The viability of the RVA particles detected was confirmed by isolation of RVA in cell culture from 5 of 10 water samples. Furthermore, an RVA waterborne outbreak of neonatal calf diarrhoea was described. We demonstrate that RVA is frequent in dairy farm waters, and that the virus is infectious and capable of generating a diarrhoea outbreak. Neonatal diarrhoea syndrome leads to economic losses to the livestock industry worldwide. To determine transmission routes is essential to take action in this regard and reduce the impact that this syndrome has for the livestock production. The results obtained in this work alert the dairy industry and highlight that mitigation strategies are crucial to improve the microbiological quality of this water. © 2018 The Society for Applied Microbiology.

Persistent bovine viral diarrhea virus (BVDV) infection in cattle herds

PubMed Central

Khodakaram-Tafti, A.; Farjanikish, GH.

2017-01-01

Bovine viral diarrhea virus (BVDV) is a significant pathogen associated with gastrointestinal, respiratory, and reproductive diseases of cattle worldwide. It causes continuous economic losses to the cattle industry primarily due to decreased reproductive performance. The ability of virus to cross the placenta during early pregnancy can result in the birth of persistently infected (PI) calves. Persistently infected animals are generally much more efficient transmitters of BVDV than transiently or acutely infected animals because they are capable of shedding large quantities of virus throughout their lives and are considered the primary reservoirs for BVDV. Due to the nature of viral infections, there is no treatment to fully cure an animal of a viral infection. All control programs which are in use in many countries of the world, mainly depend upon the detection of PI animals, eliminating them and preventing their return into the herds. Detection of PI animals at early stage, particularly soon after birth is of significant benefit to implement BVDV control programs. Available diagnostic tests such as virus isolation (VI), immunohistochemistry (IHC), Antigen-Capture ELISA (ACE), and reverse transcriptase polymerase chain reaction (RT-PCR) are used for detection of PI cattle. Each method to detect BVDV has advantages, disadvantages, and applicability for different diagnostic situations. The reliability of diagnostic tests is optimized by choosing the appropriate sampling strategy on the basis of animal age. PMID:29163643

Transient Receptor Potential Canonical 3 (TRPC3) Channels Are Required for Hypothalamic Glucose Detection and Energy Homeostasis.

PubMed

Chrétien, Chloé; Fenech, Claire; Liénard, Fabienne; Grall, Sylvie; Chevalier, Charlène; Chaudy, Sylvie; Brenachot, Xavier; Berges, Raymond; Louche, Katie; Stark, Romana; Nédélec, Emmanuelle; Laderrière, Amélie; Andrews, Zane B; Benani, Alexandre; Flockerzi, Veit; Gascuel, Jean; Hartmann, Jana; Moro, Cédric; Birnbaumer, Lutz; Leloup, Corinne; Pénicaud, Luc; Fioramonti, Xavier

2017-02-01

The mediobasal hypothalamus (MBH) contains neurons capable of directly detecting metabolic signals such as glucose to control energy homeostasis. Among them, glucose-excited (GE) neurons increase their electrical activity when glucose rises. In view of previous work, we hypothesized that transient receptor potential canonical type 3 (TRPC3) channels are involved in hypothalamic glucose detection and the control of energy homeostasis. To investigate the role of TRPC3, we used constitutive and conditional TRPC3-deficient mouse models. Hypothalamic glucose detection was studied in vivo by measuring food intake and insulin secretion in response to increased brain glucose level. The role of TRPC3 in GE neuron response to glucose was studied by using in vitro calcium imaging on freshly dissociated MBH neurons. We found that whole-body and MBH TRPC3-deficient mice have increased body weight and food intake. The anorectic effect of intracerebroventricular glucose and the insulin secretory response to intracarotid glucose injection are blunted in TRPC3-deficient mice. TRPC3 loss of function or pharmacological inhibition blunts calcium responses to glucose in MBH neurons in vitro. Together, the results demonstrate that TRPC3 channels are required for the response to glucose of MBH GE neurons and the central effect of glucose on insulin secretion and food intake. © 2017 by the American Diabetes Association.

Validity of height loss as a predictor for prevalent vertebral fractures, low bone mineral density, and vitamin D deficiency.

PubMed

Mikula, A L; Hetzel, S J; Binkley, N; Anderson, P A

2017-05-01

Many osteoporosis-related vertebral fractures are unappreciated but their detection is important as their presence increases future fracture risk. We found height loss is a useful tool in detecting patients with vertebral fractures, low bone mineral density, and vitamin D deficiency which may lead to improvements in patient care. This study aimed to determine if/how height loss can be used to identify patients with vertebral fractures, low bone mineral density, and vitamin D deficiency. A hospital database search in which four patient groups including those with a diagnosis of osteoporosis-related vertebral fracture, osteoporosis, osteopenia, or vitamin D deficiency and a control group were evaluated for chart-documented height loss over an average 3 1/2 to 4-year time period. Data was retrieved from 66,021 patients (25,792 men and 40,229 women). A height loss of 1, 2, 3, and 4 cm had a sensitivity of 42, 32, 19, and 14% in detecting vertebral fractures, respectively. Positive likelihood ratios for detecting vertebral fractures were 1.73, 2.35, and 2.89 at 2, 3, and 4 cm of height loss, respectively. Height loss had lower sensitivities and positive likelihood ratios for detecting low bone mineral density and vitamin D deficiency compared to vertebral fractures. Specificity of 1, 2, 3, and 4 cm of height loss was 70, 82, 92, and 95%, respectively. The odds ratios for a patient who loses 1 cm of height being in one of the four diagnostic groups compared to a patient who loses no height was higher for younger and male patients. This study demonstrated that prospective height loss is an effective tool to identify patients with vertebral fractures, low bone mineral density, and vitamin D deficiency although a lack of height loss does not rule out these diagnoses. If significant height loss is present, the high positive likelihood ratios support a further workup.

Status of Computational Aerodynamic Modeling Tools for Aircraft Loss-of-Control

NASA Technical Reports Server (NTRS)

Frink, Neal T.; Murphy, Patrick C.; Atkins, Harold L.; Viken, Sally A.; Petrilli, Justin L.; Gopalarathnam, Ashok; Paul, Ryan C.

2016-01-01

A concerted effort has been underway over the past several years to evolve computational capabilities for modeling aircraft loss-of-control under the NASA Aviation Safety Program. A principal goal has been to develop reliable computational tools for predicting and analyzing the non-linear stability & control characteristics of aircraft near stall boundaries affecting safe flight, and for utilizing those predictions for creating augmented flight simulation models that improve pilot training. Pursuing such an ambitious task with limited resources required the forging of close collaborative relationships with a diverse body of computational aerodynamicists and flight simulation experts to leverage their respective research efforts into the creation of NASA tools to meet this goal. Considerable progress has been made and work remains to be done. This paper summarizes the status of the NASA effort to establish computational capabilities for modeling aircraft loss-of-control and offers recommendations for future work.

Pulse-Shape Discrimination of Alpha Particles of Different Specific Energy-Loss With Parallel-Plate Avalanche Counters

NASA Astrophysics Data System (ADS)

Nakhostin, M.; Baba, M.

2014-06-01

Parallel-plate avalanche counters have long been recognized as timing detectors for heavily ionizing particles. However, these detectors suffer from a poor pulse-height resolution which limits their capability to discriminate between different ionizing particles. In this paper, a new approach for discriminating between charged particles of different specific energy-loss with avalanche counters is demonstrated. We show that the effect of the self-induced space-charge in parallel-plate avalanche counters leads to a strong correlation between the shape of output current pulses and the amount of primary ionization created by the incident charged particles. The correlation is then exploited for the discrimination of charged particles with different energy-losses in the detector. The experimental results obtained with α-particles from an 241Am α-source demonstrate a discrimination capability far beyond that achievable with the standard pulse-height discrimination method.

Detection of bovine mastitis pathogens by loop-mediated isothermal amplification and an electrochemical DNA chip.

PubMed

Kawai, Kazuhiro; Inada, Mika; Ito, Keiko; Hashimoto, Koji; Nikaido, Masaru; Hata, Eiji; Katsuda, Ken; Kiku, Yoshio; Tagawa, Yuichi; Hayashi, Tomohito

2017-12-22

Bovine mastitis causes significant economic losses in the dairy industry. Effective prevention of bovine mastitis requires an understanding of the infection status of a pathogenic microorganism in a herd that has not yet shown clinical signs of mastitis and appropriate treatment specific for the pathogenic microorganism. However, bacterial identification by culture has drawbacks in that the sensitivity may be low and the procedure can be complex. In this study, we developed a genetic detection method to identify mastitis pathogens using a simple and highly sensitive electrochemical DNA chip which can specifically detect bacterial DNA in milk specimens. First, we selected microorganisms belonging to 12 families and/or genera associated with mastitis for which testing should be performed. Next, we optimized the conditions for amplifying microorganism DNA by loop-mediated isothermal amplification (LAMP) using 32 primers and the use of a DNA chip capable of measuring all pathogens simultaneously. Sample detection could be completed in just a few hours using this method. Comparison of the results obtained with our DNA chip method and those obtained by bacterial culture verified that when the culture method was set to 100%, the total positive concordance rate of the DNA chip was 85.0% and the total negative concordance rate was 86.9%. Furthermore, the proposed method allows both rapid and highly sensitive detection of mastitis pathogens. We believe that this method will contribute to the development of an effective mastitis control program.

Detection of bovine mastitis pathogens by loop-mediated isothermal amplification and an electrochemical DNA chip

PubMed Central

KAWAI, Kazuhiro; INADA, Mika; ITO, Keiko; HASHIMOTO, Koji; NIKAIDO, Masaru; HATA, Eiji; KATSUDA, Ken; KIKU, Yoshio; TAGAWA, Yuichi; HAYASHI, Tomohito

2017-01-01

Bovine mastitis causes significant economic losses in the dairy industry. Effective prevention of bovine mastitis requires an understanding of the infection status of a pathogenic microorganism in a herd that has not yet shown clinical signs of mastitis and appropriate treatment specific for the pathogenic microorganism. However, bacterial identification by culture has drawbacks in that the sensitivity may be low and the procedure can be complex. In this study, we developed a genetic detection method to identify mastitis pathogens using a simple and highly sensitive electrochemical DNA chip which can specifically detect bacterial DNA in milk specimens. First, we selected microorganisms belonging to 12 families and/or genera associated with mastitis for which testing should be performed. Next, we optimized the conditions for amplifying microorganism DNA by loop-mediated isothermal amplification (LAMP) using 32 primers and the use of a DNA chip capable of measuring all pathogens simultaneously. Sample detection could be completed in just a few hours using this method. Comparison of the results obtained with our DNA chip method and those obtained by bacterial culture verified that when the culture method was set to 100%, the total positive concordance rate of the DNA chip was 85.0% and the total negative concordance rate was 86.9%. Furthermore, the proposed method allows both rapid and highly sensitive detection of mastitis pathogens. We believe that this method will contribute to the development of an effective mastitis control program. PMID:29093278

An Evaluation of Quantitative PCR Assays (TaqMan® and SYBR Green) for the Detection of Babesia bigemina and Babesia bovis, and a Novel Fluorescent-ITS1-PCR Capillary Electrophoresis Method for Genotyping B. bovis Isolates

PubMed Central

Zhang, Bing; Sambono, Jacqueline L.; Morgan, Jess A. T.; Venus, Bronwyn; Rolls, Peter; Lew-Tabor, Ala E.

2016-01-01

Babesia spp. are tick-transmitted haemoparasites causing tick fever in cattle. In Australia, economic losses to the cattle industry from tick fever are estimated at AUD$26 Million per annum. If animals recover from these infections, they become immune carriers. Here we describe a novel multiplex TaqMan qPCR targeting cytochrome b genes for the identification of Babesia spp. The assay shows high sensitivity, specificity and reproducibility, and allows quantification of parasite DNA from Babesia bovis and B. bigemina compared to standard PCR assays. A previously published cytochrome b SYBR Green qPCR was also tested in this study, showing slightly higher sensitivity than the Taqman qPCRs but requires melting curve analysis post-PCR to confirm specificity. The SYBR Green assays were further evaluated using both diagnostic submissions and vaccinated cattle (at 7, 9, 11 and 14 days post-inoculation) showed that B. bigemina can be detected more frequently than B. bovis. Due to fewer circulating parasites, B. bovis detection in carrier animals requires higher DNA input. Preliminary data for a novel fluorescent PCR genotyping based on the Internal Transcribed Spacer 1 region to detect vaccine and field alleles of B. bovis are described. This assay is capable of detecting vaccine and novel field isolate alleles in a single sample. PMID:29056732

The economic value of remote sensing of earth resources from space: An ERTS overview and the value of continuity of service. Volume 3: Intensive use of living resources: Agriculture. Part 1: Overview

NASA Technical Reports Server (NTRS)

Kornhauser, A. L.; Wilson, L. B.

1974-01-01

Potential economic benefits obtainable from a state-of-the-art ERS system in the resource area of intensive use of living resources, agriculture, are studied. A spectrum of equal capability (cost saving), increased capability, and new capability benefits are quantified. These benefits are estimated via ECON developed models of the agricultural marketplace and include benefits of improved production and distribution of agricultural crops. It is shown that increased capability benefits and new capability benefits result from a reduction of losses due to disease and insect infestation given ERS's capability to distinguish crop vigor and from the improvement in world trade negotiations given ERS's worldwide surveying capability.

Comparison of Methods for Assessing Body Composition Changes during Weight Loss.

ERIC Educational Resources Information Center

Weyers, Anna M.; Mazzetti, Scott A.; Love, Dawn M.; Gomez, Ana L.; Kraemer, William J.; Volek, Jeff S.

2002-01-01

Investigated whether dual-energy x-ray absorptiometry (DXA) and air displacement plethysmography (ADP) would detect similar changes in body composition after moderate weight loss. Twenty adults had their body composition measured using DXA and ADP before and after an 8-week weight loss program. Overall, both DXA and ADP detected similar changes in…

Thermodynamic framework to assess low abundance DNA mutation detection by hybridization.

PubMed

Willems, Hanny; Jacobs, An; Hadiwikarta, Wahyu Wijaya; Venken, Tom; Valkenborg, Dirk; Van Roy, Nadine; Vandesompele, Jo; Hooyberghs, Jef

2017-01-01

The knowledge of genomic DNA variations in patient samples has a high and increasing value for human diagnostics in its broadest sense. Although many methods and sensors to detect or quantify these variations are available or under development, the number of underlying physico-chemical detection principles is limited. One of these principles is the hybridization of sample target DNA versus nucleic acid probes. We introduce a novel thermodynamics approach and develop a framework to exploit the specific detection capabilities of nucleic acid hybridization, using generic principles applicable to any platform. As a case study, we detect point mutations in the KRAS oncogene on a microarray platform. For the given platform and hybridization conditions, we demonstrate the multiplex detection capability of hybridization and assess the detection limit using thermodynamic considerations; DNA containing point mutations in a background of wild type sequences can be identified down to at least 1% relative concentration. In order to show the clinical relevance, the detection capabilities are confirmed on challenging formalin-fixed paraffin-embedded clinical tumor samples. This enzyme-free detection framework contains the accuracy and efficiency to screen for hundreds of mutations in a single run with many potential applications in molecular diagnostics and the field of personalised medicine.

Caprine Monocytes Release Extracellular Traps against Neospora caninum In Vitro

PubMed Central

Yang, Zhengtao; Wei, Zhengkai; Hermosilla, Carlos; Taubert, Anja; He, Xuexiu; Wang, Xiaocen; Gong, Pengtao; Li, Jianhua; Zhang, Xichen

2018-01-01

Neospora caninum is an obligate intracellular apicomplexan parasite that causes reproductive loss and severe economic losses in dairy and goat industry. In the present study, we aim to investigate the effects of N. caninum tachyzoites on the release of extracellular traps (ETs) in caprine monocytes and furthermore elucidated parts of its molecular mechanisms. N. caninum tachyzoite-induced monocytes-derived ETs formation was detected by scanning electron microscopy. H3 and myeloperoxidase (MPO) within monocyte-ETs structures were examined using laser scanning confocal microscopy analyses. The results showed that N. caninum tachyzoites were not only able to trigger ETs formation in caprine monocytes, but also that monocyte-released ETs were capable of entrapping viable tachyzoites. Histones and MPO were found to be decorating the DNA within the monocytes derived-ETs structures thus proving the classical components of ETs. Furthermore, inhibitors of NADPH oxidase-, MPO-, ERK 1/2-, or p38 MAPK-signaling pathway significantly decreased N. caninum tachyzoite-triggered caprine monocyte-derived ETosis. This is the first report of ETs release extruded from caprine monocytes after N. caninum exposure and thus showing that this early innate immune effector mechanism might be relevant during the acute phase of caprine neosporosis. PMID:29403487

EGRET High Energy Capability and Multiwavelength Flare Studies and Solar Flare Proton Spectra

NASA Technical Reports Server (NTRS)

Chupp, Edward L.

1997-01-01

UNH was assigned the responsibility to use their accelerator neutron measurements to verify the TASC response function and to modify the TASC fitting program to include a high energy neutron contribution. Direct accelerator-based measurements by UNH of the energy-dependent efficiencies for detecting neutrons with energies from 36 to 720 MeV in NaI were compared with Monte Carlo TASC calculations. The calculated TASC efficiencies are somewhat lower (by about 20%) than the accelerator results in the energy range 70-300 MeV. The measured energy-loss spectrum for 207 MeV neutron interactions in NaI were compared with the Monte Carlo response for 200 MeV neutrons in the TASC indicating good agreement. Based on this agreement, the simulation was considered to be sufficiently accurate to generate a neutron response library to be used by UNH in modifying the TASC fitting program to include a neutron component in the flare spectrum modeling. TASC energy-loss data on the 1991 June 11 flare was transferred to UNH. Also included appendix: Gamma-rays and neutrons as a probe of flare proton spectra: the solar flare of 11 June 1991.

Performance Assessment of Hearing Protection and Communication Enhancement Devices: Peltor Comtac III and IV

DTIC Science & Technology

2015-07-01

providing a hear-thru, or active capability while mitigating hearing loss and tinnitus caused by exposure to loud, steady-state and impulse noise. Active...loss and tinnitus caused by exposure to loud, steady-state and impulse noise. The general approach was to use ANSI standard measurement procedures

High-Level Psychophysical Tuning Curves: Forward Masking in Normal-Hearing and Hearing-Impaired Listeners.

ERIC Educational Resources Information Center

Nelson, David A.

1991-01-01

Forward-masked psychophysical tuning curves were obtained at multiple probe levels from 26 normal-hearing listeners and 24 ears of 21 hearing-impaired listeners with cochlear hearing loss. Results indicated that some cochlear hearing losses influence the sharp tuning capabilities usually associated with outer hair cell function. (Author/JDD)

Fault detection monitor circuit provides ''self-heal capability'' in electronic modules - A concept

NASA Technical Reports Server (NTRS)

Kennedy, J. J.

1970-01-01

Self-checking technique detects defective solid state modules used in electronic test and checkout instrumentation. A ten bit register provides failure monitor and indication for 1023 comparator circuits, and the automatic fault-isolation capability permits the electronic subsystems to be repaired by replacing the defective module.

Differential equation models for sharp threshold dynamics.

PubMed

Schramm, Harrison C; Dimitrov, Nedialko B

2014-01-01

We develop an extension to differential equation models of dynamical systems to allow us to analyze probabilistic threshold dynamics that fundamentally and globally change system behavior. We apply our novel modeling approach to two cases of interest: a model of infectious disease modified for malware where a detection event drastically changes dynamics by introducing a new class in competition with the original infection; and the Lanchester model of armed conflict, where the loss of a key capability drastically changes the effectiveness of one of the sides. We derive and demonstrate a step-by-step, repeatable method for applying our novel modeling approach to an arbitrary system, and we compare the resulting differential equations to simulations of the system's random progression. Our work leads to a simple and easily implemented method for analyzing probabilistic threshold dynamics using differential equations. Published by Elsevier Inc.

[Analysis on occupational noise-induced hearing loss of different type workers in underground mining].

PubMed

Liu, Q C; Duo, C H; Wang, Z; Yan, K; Zhang, J; Xiong, W; Zhu, M

2017-11-20

Objective: To investigate hearing loss status of blasters, drillers mechanics and so on in underground mining, and put forward suggestion diagnosis of occupational explosive deafness and occupational deafness. Methods: Underground excavation workers in a metal mine were recruited in this study, those with a history of ear disease and non-occupational deafness were all excluded. Finally, the features of pure tone audiometry of 459 noise-exposed workers were analyzed. Results: High-frequency hearing loss occurred on 351workers and the positive detection rate was 74.29%, workers who had both high-frequency and linguistic frequency hearing loss were 51 and the positive detection rate was 11.11%. The positive detection of high-frequency hearing loss in right ear (χ(2)=9.427 and P = 0.024) and in left ear (χ(2)=14.375, P =0.002) was significantly different between different exposure age groups. The positive detection of high-frequency hearing loss of driving group was the highest, followed by blasting group, mining group and machine repair group. The characteristics of the hearing loss caused by drilling noise of the blasting workers with no accident occurred were in line with that of noise-induced hearing loss. Conclusion: The diagnosis grading should be carried out according to the diagnostic criteria of occupational noise-induced deafness for the employees who engaged in the blasting operation with no record of blast accident.

Internetting tactical security sensor systems

NASA Astrophysics Data System (ADS)

Gage, Douglas W.; Bryan, W. D.; Nguyen, Hoa G.

1998-08-01

The Multipurpose Surveillance and Security Mission Platform (MSSMP) is a distributed network of remote sensing packages and control stations, designed to provide a rapidly deployable, extended-range surveillance capability for a wide variety of military security operations and other tactical missions. The baseline MSSMP sensor suite consists of a pan/tilt unit with video and FLIR cameras and laser rangefinder. With an additional radio transceiver, MSSMP can also function as a gateway between existing security/surveillance sensor systems such as TASS, TRSS, and IREMBASS, and IP-based networks, to support the timely distribution of both threat detection and threat assessment information. The MSSMP system makes maximum use of Commercial Off The Shelf (COTS) components for sensing, processing, and communications, and of both established and emerging standard communications networking protocols and system integration techniques. Its use of IP-based protocols allows it to freely interoperate with the Internet -- providing geographic transparency, facilitating development, and allowing fully distributed demonstration capability -- and prepares it for integration with the IP-based tactical radio networks that will evolve in the next decade. Unfortunately, the Internet's standard Transport layer protocol, TCP, is poorly matched to the requirements of security sensors and other quasi- autonomous systems in being oriented to conveying a continuous data stream, rather than discrete messages. Also, its canonical 'socket' interface both conceals short losses of communications connectivity and simply gives up and forces the Application layer software to deal with longer losses. For MSSMP, a software applique is being developed that will run on top of User Datagram Protocol (UDP) to provide a reliable message-based Transport service. In addition, a Session layer protocol is being developed to support the effective transfer of control of multiple platforms among multiple control stations.

A pilot study of sensory feedback by transcutaneous electrical nerve stimulation to improve manipulation deficit caused by severe sensory loss after stroke

PubMed Central

2013-01-01

Background Sensory disturbance is common following stroke and can exacerbate functional deficits, even in patients with relatively good motor function. In particular, loss of appropriate sensory feedback in severe sensory loss impairs manipulation capability. We hypothesized that task-oriented training with sensory feedback assistance would improve manipulation capability even without sensory pathway recovery. Methods We developed a system that provides sensory feedback by transcutaneous electrical nerve stimulation (SENS) for patients with sensory loss, and investigated the feasibility of the system in a stroke patient with severe sensory impairment and mild motor deficit. The electrical current was modulated by the force exerted by the fingertips so as to allow the patient to identify the intensity. The patient had severe sensory loss due to a right thalamic hemorrhage suffered 27 months prior to participation in the study. The patient first practiced a cylindrical grasp task with SENS for 1 hour daily over 29 days. Pressure information from the affected thumb was fed back to the unaffected shoulder. The same patient practiced a tip pinch task with SENS for 1 hour daily over 4 days. Pressure information from the affected thumb and index finger was fed back to the unaffected and affected shoulders, respectively. We assessed the feasibility of SENS and examined the improvement of manipulation capability after training with SENS. Results The fluctuation in fingertip force during the cylindrical grasp task gradually decreased as the training progressed. The patient was able to maintain a stable grip force after training, even without SENS. Pressure exerted by the tip pinch of the affected hand was unstable before intervention with SENS compared with that of the unaffected hand. However, they were similar to each other immediately after SENS was initiated, suggesting that the somatosensory information improved tip pinch performance. The patient’s manipulation capability assessed by the Box and Block Test score improved through SENS intervention and was partly maintained after SENS was removed, until at least 7 months after the intervention. The sensory test score, however, showed no recovery after intervention. Conclusions We conclude that the proposed system would be useful in the rehabilitation of patients with sensory loss. PMID:23764012

A pilot study of sensory feedback by transcutaneous electrical nerve stimulation to improve manipulation deficit caused by severe sensory loss after stroke.

PubMed

Kita, Kahori; Otaka, Yohei; Takeda, Kotaro; Sakata, Sachiko; Ushiba, Junichi; Kondo, Kunitsugu; Liu, Meigen; Osu, Rieko

2013-06-13

Sensory disturbance is common following stroke and can exacerbate functional deficits, even in patients with relatively good motor function. In particular, loss of appropriate sensory feedback in severe sensory loss impairs manipulation capability. We hypothesized that task-oriented training with sensory feedback assistance would improve manipulation capability even without sensory pathway recovery. We developed a system that provides sensory feedback by transcutaneous electrical nerve stimulation (SENS) for patients with sensory loss, and investigated the feasibility of the system in a stroke patient with severe sensory impairment and mild motor deficit. The electrical current was modulated by the force exerted by the fingertips so as to allow the patient to identify the intensity. The patient had severe sensory loss due to a right thalamic hemorrhage suffered 27 months prior to participation in the study. The patient first practiced a cylindrical grasp task with SENS for 1 hour daily over 29 days. Pressure information from the affected thumb was fed back to the unaffected shoulder. The same patient practiced a tip pinch task with SENS for 1 hour daily over 4 days. Pressure information from the affected thumb and index finger was fed back to the unaffected and affected shoulders, respectively. We assessed the feasibility of SENS and examined the improvement of manipulation capability after training with SENS. The fluctuation in fingertip force during the cylindrical grasp task gradually decreased as the training progressed. The patient was able to maintain a stable grip force after training, even without SENS. Pressure exerted by the tip pinch of the affected hand was unstable before intervention with SENS compared with that of the unaffected hand. However, they were similar to each other immediately after SENS was initiated, suggesting that the somatosensory information improved tip pinch performance. The patient's manipulation capability assessed by the Box and Block Test score improved through SENS intervention and was partly maintained after SENS was removed, until at least 7 months after the intervention. The sensory test score, however, showed no recovery after intervention. We conclude that the proposed system would be useful in the rehabilitation of patients with sensory loss.

Integrated multisensor perimeter detection systems

NASA Astrophysics Data System (ADS)

Kent, P. J.; Fretwell, P.; Barrett, D. J.; Faulkner, D. A.

2007-10-01

The report describes the results of a multi-year programme of research aimed at the development of an integrated multi-sensor perimeter detection system capable of being deployed at an operational site. The research was driven by end user requirements in protective security, particularly in threat detection and assessment, where effective capability was either not available or prohibitively expensive. Novel video analytics have been designed to provide robust detection of pedestrians in clutter while new radar detection and tracking algorithms provide wide area day/night surveillance. A modular integrated architecture based on commercially available components has been developed. A graphical user interface allows intuitive interaction and visualisation with the sensors. The fusion of video, radar and other sensor data provides the basis of a threat detection capability for real life conditions. The system was designed to be modular and extendable in order to accommodate future and legacy surveillance sensors. The current sensor mix includes stereoscopic video cameras, mmWave ground movement radar, CCTV and a commercially available perimeter detection cable. The paper outlines the development of the system and describes the lessons learnt after deployment in a pilot trial.

TR-BREATH: Time-Reversal Breathing Rate Estimation and Detection.

PubMed

Chen, Chen; Han, Yi; Chen, Yan; Lai, Hung-Quoc; Zhang, Feng; Wang, Beibei; Liu, K J Ray

2018-03-01

In this paper, we introduce TR-BREATH, a time-reversal (TR)-based contact-free breathing monitoring system. It is capable of breathing detection and multiperson breathing rate estimation within a short period of time using off-the-shelf WiFi devices. The proposed system exploits the channel state information (CSI) to capture the miniature variations in the environment caused by breathing. To magnify the CSI variations, TR-BREATH projects CSIs into the TR resonating strength (TRRS) feature space and analyzes the TRRS by the Root-MUSIC and affinity propagation algorithms. Extensive experiment results indoor demonstrate a perfect detection rate of breathing. With only 10 s of measurement, a mean accuracy of can be obtained for single-person breathing rate estimation under the non-line-of-sight (NLOS) scenario. Furthermore, it achieves a mean accuracy of in breathing rate estimation for a dozen people under the line-of-sight scenario and a mean accuracy of in breathing rate estimation of nine people under the NLOS scenario, both with 63 s of measurement. Moreover, TR-BREATH can estimate the number of people with an error around 1. We also demonstrate that TR-BREATH is robust against packet loss and motions. With the prevailing of WiFi, TR-BREATH can be applied for in-home and real-time breathing monitoring.

Small Arrays for Seismic Intruder Detections: A Simulation Based Experiment

NASA Astrophysics Data System (ADS)

Pitarka, A.

2014-12-01

Seismic sensors such as geophones and fiber optic have been increasingly recognized as promising technologies for intelligence surveillance, including intruder detection and perimeter defense systems. Geophone arrays have the capability to provide cost effective intruder detection in protecting assets with large perimeters. A seismic intruder detection system uses one or multiple arrays of geophones design to record seismic signals from footsteps and ground vehicles. Using a series of real-time signal processing algorithms the system detects, classify and monitors the intruder's movement. We have carried out numerical experiments to demonstrate the capability of a seismic array to detect moving targets that generate seismic signals. The seismic source is modeled as a vertical force acting on the ground that generates continuous impulsive seismic signals with different predominant frequencies. Frequency-wave number analysis of the synthetic array data was used to demonstrate the array's capability at accurately determining intruder's movement direction. The performance of the array was also analyzed in detecting two or more objects moving at the same time. One of the drawbacks of using a single array system is its inefficiency at detecting seismic signals deflected by large underground objects. We will show simulation results of the effect of an underground concrete block at shielding the seismic signal coming from an intruder. Based on simulations we found that multiple small arrays can greatly improve the system's detection capability in the presence of underground structures. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344

Evaluation of the Orbitrap Mass Spectrometer for the Molecular Fingerprinting Analysis of Natural Dissolved Organic Matter.

PubMed

Hawkes, Jeffrey A; Dittmar, Thorsten; Patriarca, Claudia; Tranvik, Lars; Bergquist, Jonas

2016-08-02

We investigated the application of the LTQ-Orbitrap mass spectrometer (LTQ-Velos Pro, Thermo Fisher) for resolving complex mixtures of natural aquatic dissolved organic matter (DOM) and compared this technique to the more established state-of-the-art technique, Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS, Bruker Daltonics), in terms of the distribution of molecular masses detected and the reproducibility of the results collected. The Orbitrap was capable of excellent reproducibility: Bray-Curtis dissimilarity between duplicate measurements was 2.85 ± 0.42% (mean ± standard deviation). The Orbitrap was also capable of the detection of most major ionizable organic molecules in typical aquatic mixtures, with the exception of most sulfur and phosphorus containing masses. This result signifies that the Orbitrap is an appropriate technique for the investigation of very subtle biogeochemical processing of bulk DOM. The lower costs (purchase and maintenance) and wider availability of Orbitrap mass spectrometers in university departments means that the tools necessary for research into DOM processing at the molecular level should be accessible to a much wider group of scientists than before. The main disadvantage of the technique is that substantially fewer molecular formulas can be resolved from a complex mixture (roughly one third as many), meaning some loss of information. In balance, most biogeochemical studies that aim at molecularly fingerprinting the source of natural DOM could be satisfactorily carried out with Orbitrap mass spectrometry. For more targeted metabolomic studies where individual compounds are traced through natural systems, FTICR-MS remains advantageous.

Integration of Quartz Crystal Microbalance-Dissipation and Reflection-Mode Localized Surface Plasmon Resonance Sensors for Biomacromolecular Interaction Analysis.

PubMed

Ferhan, Abdul Rahim; Jackman, Joshua A; Cho, Nam-Joon

2016-12-20

The combination of label-free, surface-sensitive measurement techniques based on different physical principles enables detailed characterization of biomacromolecular interactions at solid-liquid interfaces. To date, most combined measurement systems have involved experimental techniques with similar probing volumes, whereas the potential of utilizing techniques with different surface sensitivities remains largely unexplored, especially for data interpretation. Herein, we report a combined measurement approach that integrates a conventional quartz crystal microbalance-dissipation (QCM-D) setup with a reflection-mode localized surface plasmon (LSPR) sensor. Using this platform, we investigate vesicle adsorption on a titanium oxide-coated sensing substrate along with the amphipathic, α-helical (AH) peptide-induced structural transformation of surface-adsorbed lipid vesicles into a supported lipid bilayer (SLB) as a model biomacromolecular interaction. While the QCM-D and LSPR signals both detected mass uptake arising from vesicle adsorption, tracking the AH peptide-induced structural transformation revealed more complex measurement responses based on the different surface sensitivities of the two techniques. In particular, the LSPR signal recorded an increase in optical mass near the sensor surface which indicated SLB formation, whereas the QCM-D signals detected a significant loss in net acoustic mass due to excess lipid and coupled solvent leaving the probing volume. Importantly, these measurement capabilities allowed us to temporally distinguish the process of SLB formation at the sensor surface from the overall structural transformation process. Looking forward, these label-free measurement capabilities to simultaneously probe adsorbates at multiple length scales will provide new insights into complex biomacromolecular interactions.

Recording membrane potential changes through photoacoustic voltage sensitive dye

NASA Astrophysics Data System (ADS)

Zhang, Haichong K.; Kang, Jeeun; Yan, Ping; Abou, Diane S.; Le, Hanh N. D.; Thorek, Daniel L. J.; Kang, Jin U.; Gjedde, Albert; Rahmim, Arman; Wong, Dean F.; Loew, Leslie M.; Boctor, Emad M.

2017-03-01

Monitoring of the membrane potential is possible using voltage sensitive dyes (VSD), where fluorescence intensity changes in response to neuronal electrical activity. However, fluorescence imaging is limited by depth of penetration and high scattering losses, which leads to low sensitivity in vivo systems for external detection. In contrast, photoacoustic (PA) imaging, an emerging modality, is capable of deep tissue, noninvasive imaging by combining near infrared light excitation and ultrasound detection. In this work, we develop the theoretical concept whereby the voltage-dependent quenching of dye fluorescence leads to a reciprocal enhancement of PA intensity. Based on this concept, we synthesized a novel near infrared photoacoustic VSD (PA-VSD) whose PA intensity change is sensitive to membrane potential. In the polarized state, this cyanine-based probe enhances PA intensity while decreasing fluorescence output in a lipid vesicle membrane model. With a 3-9 μM VSD concentration, we measured a PA signal increase in the range of 5.3 % to 18.1 %, and observed a corresponding signal reduction in fluorescence emission of 30.0 % to 48.7 %. A theoretical model successfully accounts for how the experimental PA intensity change depends on fluorescence and absorbance properties of the dye. These results not only demonstrate the voltage sensing capability of the dye, but also indicate the necessity of considering both fluorescence and absorbance spectral sensitivities in order to optimize the characteristics of improved photoacoustic probes. Together, our results demonstrate photoacoustic sensing as a potential new modality for sub-second recording and external imaging of electrophysiological and neurochemical events in the brain.

Space Launch Systems Block 1B Preliminary Navigation System Design

NASA Technical Reports Server (NTRS)

Oliver, T. Emerson; Park, Thomas; Anzalone, Evan; Smith, Austin; Strickland, Dennis; Patrick, Sean

2018-01-01

NASA is currently building the Space Launch Systems (SLS) Block 1 launch vehicle for the Exploration Mission 1 (EM-1) test flight. In parallel, NASA is also designing the Block 1B launch vehicle. The Block 1B vehicle is an evolution of the Block 1 vehicle and extends the capability of the NASA launch vehicle. This evolution replaces the Interim Cryogenic Propulsive Stage (ICPS) with the Exploration Upper Stage (EUS). As the vehicle evolves to provide greater lift capability, increased robustness for manned missions, and the capability to execute more demanding missions so must the SLS Integrated Navigation System evolved to support those missions. This paper describes the preliminary navigation systems design for the SLS Block 1B vehicle. The evolution of the navigation hard-ware and algorithms from an inertial-only navigation system for Block 1 ascent flight to a tightly coupled GPS-aided inertial navigation system for Block 1B is described. The Block 1 GN&C system has been designed to meet a LEO insertion target with a specified accuracy. The Block 1B vehicle navigation system is de-signed to support the Block 1 LEO target accuracy as well as trans-lunar or trans-planetary injection accuracy. Additionally, the Block 1B vehicle is designed to support human exploration and thus is designed to minimize the probability of Loss of Crew (LOC) through high-quality inertial instruments and robust algorithm design, including Fault Detection, Isolation, and Recovery (FDIR) logic.

Aircraft Abnormal Conditions Detection, Identification, and Evaluation Using Innate and Adaptive Immune Systems Interaction

NASA Astrophysics Data System (ADS)

Al Azzawi, Dia

Abnormal flight conditions play a major role in aircraft accidents frequently causing loss of control. To ensure aircraft operation safety in all situations, intelligent system monitoring and adaptation must rely on accurately detecting the presence of abnormal conditions as soon as they take place, identifying their root cause(s), estimating their nature and severity, and predicting their impact on the flight envelope. Due to the complexity and multidimensionality of the aircraft system under abnormal conditions, these requirements are extremely difficult to satisfy using existing analytical and/or statistical approaches. Moreover, current methodologies have addressed only isolated classes of abnormal conditions and a reduced number of aircraft dynamic parameters within a limited region of the flight envelope. This research effort aims at developing an integrated and comprehensive framework for the aircraft abnormal conditions detection, identification, and evaluation based on the artificial immune systems paradigm, which has the capability to address the complexity and multidimensionality issues related to aircraft systems. Within the proposed framework, a novel algorithm was developed for the abnormal conditions detection problem and extended to the abnormal conditions identification and evaluation. The algorithm and its extensions were inspired from the functionality of the biological dendritic cells (an important part of the innate immune system) and their interaction with the different components of the adaptive immune system. Immunity-based methodologies for re-assessing the flight envelope at post-failure and predicting the impact of the abnormal conditions on the performance and handling qualities are also proposed and investigated in this study. The generality of the approach makes it applicable to any system. Data for artificial immune system development were collected from flight tests of a supersonic research aircraft within a motion-based flight simulator. The abnormal conditions considered in this work include locked actuators (stabilator, aileron, rudder, and throttle), structural damage of the wing, horizontal tail, and vertical tail, malfunctioning sensors, and reduced engine effectiveness. The results of applying the proposed approach to this wide range of abnormal conditions show its high capability in detecting the abnormal conditions with zero false alarms and very high detection rates, correctly identifying the failed subsystem and evaluating the type and severity of the failure. The results also reveal that the post-failure flight envelope can be reasonably predicted within this framework.

UltraSensitive Mycotoxin Detection by STING Sensors

PubMed Central

Actis, Paolo; Jejelowo, Olufisayo; Pourmand, Nader

2010-01-01

Signal Transduction by Ion Nano Gating (STING) technology is a label-free biosensor capable of identifying DNA and proteins. Based on a functionalized quartz nanopipette, the STING sensor includes specific recognition elements for analyte discrimination based on size, shape and charge density. A key feature of this technology is that it doesn't require any nanofabrication facility; each nanopipette can be easily, reproducibly, and inexpensively fabricated and tailored at the bench, thus reducing the cost and the turnaround time. Here, we show that STING sensors are capable of the ultrasensitive detection of HT-2 toxin with a detection limit of 100 fg/ml and compare the STING capabilities with respect to conventional sandwich assay techniques. PMID:20829024

Eddy Current System for Detection of Cracking Beneath Braiding in Corrugated Metal Hose

NASA Astrophysics Data System (ADS)

Wincheski, Buzz; Simpson, John; Hall, George

2009-03-01

In this paper an eddy current system for the detection of partially-through-the-thickness cracks in corrugated metal hose is presented. Design criteria based upon the geometry and conductivity of the part are developed and applied to the fabrication of a prototype inspection system. Experimental data are used to highlight the capabilities of the system and an image processing technique is presented to improve flaw detection capabilities. A case study for detection of cracking damage in a space shuttle radiator retract flex hoses is also presented.

Eddy Current System for Detection of Cracking Beneath Braiding in Corrugated Metal Hose

NASA Technical Reports Server (NTRS)

Wincheski, Buzz; Simpson, John; Hall, George

2008-01-01

In this paper an eddy current system for the detection of partially-through-the-thickness cracks in corrugated metal hose is presented. Design criteria based upon the geometry and conductivity of the part are developed and applied to the fabrication of a prototype inspection system. Experimental data are used to highlight the capabilities of the system and an image processing technique is presented to improve flaw detection capabilities. A case study for detection of cracking damage in a space shuttle radiator retract flex hoses is also presented.

Cassette bacteria detection system. [for monitoring the sterility of regenerated water in spacecraft

NASA Technical Reports Server (NTRS)

1974-01-01

The design, fabrication, and testing of an automatic bacteria detection system, with a zero-g capability, based on the filter-capable approach, and intended for monitoring the sterility of regenerated water in spacecraft is discussed. The principle of detection is based on measuring the increase in chemiluminescence produced by the action of bacterial porphyrins on a luminol-hydrogen peroxide mixture. Viable organisms are detected by comparing the signal of an incubated water sample with an unincubated control. High signals for the incubated water sample indicate the presence of viable organisms.

Interactions between amplitude modulation and frequency modulation processing: Effects of age and hearing loss.

PubMed

Paraouty, Nihaad; Ewert, Stephan D; Wallaert, Nicolas; Lorenzi, Christian

2016-07-01

Frequency modulation (FM) and amplitude modulation (AM) detection thresholds were measured for a 500-Hz carrier frequency and a 5-Hz modulation rate. For AM detection, FM at the same rate as the AM was superimposed with varying FM depth. For FM detection, AM at the same rate was superimposed with varying AM depth. The target stimuli always contained both amplitude and frequency modulations, while the standard stimuli only contained the interfering modulation. Young and older normal-hearing listeners, as well as older listeners with mild-to-moderate sensorineural hearing loss were tested. For all groups, AM and FM detection thresholds were degraded in the presence of the interfering modulation. AM detection with and without interfering FM was hardly affected by either age or hearing loss. While aging had an overall detrimental effect on FM detection with and without interfering AM, there was a trend that hearing loss further impaired FM detection in the presence of AM. Several models using optimal combination of temporal-envelope cues at the outputs of off-frequency filters were tested. The interfering effects could only be predicted for hearing-impaired listeners. This indirectly supports the idea that, in addition to envelope cues resulting from FM-to-AM conversion, normal-hearing listeners use temporal fine-structure cues for FM detection.

Managing fire risk during drought: the influence of certification and El Niño on fire-driven forest conversion for oil palm in Southeast Asia

NASA Astrophysics Data System (ADS)

Noojipady, Praveen; Morton, Douglas C.; Schroeder, Wilfrid; Carlson, Kimberly M.; Huang, Chengquan; Gibbs, Holly K.; Burns, David; Walker, Nathalie F.; Prince, Stephen D.

2017-08-01

Indonesia and Malaysia have emerged as leading producers of palm oil in the past several decades, expanding production through the conversion of tropical forests to industrial plantations. Efforts to produce sustainable palm oil, including certification by the Roundtable on Sustainable Palm Oil (RSPO), include guidelines designed to reduce the environmental impact of palm oil production. Fire-driven deforestation is prohibited by law in both countries and a stipulation of RSPO certification, yet the degree of environmental compliance is unclear, especially during El Niño events when drought conditions increase fire risk. Here, we used time series of satellite data to estimate the spatial and temporal patterns of fire-driven deforestation on and around oil palm plantations. In Indonesia, fire-driven deforestation accounted for one-quarter of total forest losses on both certified and noncertified plantations. After the first plantations in Indonesia received RSPO certification in 2009, forest loss and fire-driven deforestation declined on certified plantations but did not stop altogether. Oil palm expansion in Malaysia rarely involved fire; only 5 % of forest loss on certified plantations had coincident active fire detections. Interannual variability in fire detections was strongly influenced by El Niño and the timing of certification. Fire activity during the 2002, 2004, and 2006 El Niño events was similar among oil palm plantations in Indonesia that would later become certified, noncertified plantations, and surrounding areas. However, total fire activity was 75 % and 66 % lower on certified plantations than noncertified plantations during the 2009 and 2015 El Niño events, respectively. The decline in fire activity on certified plantations, including during drought periods, highlights the potential for RSPO certification to safeguard carbon stocks in peatlands and remaining forests in accordance with legislation banning fires. However, aligning certification standards with satellite monitoring capabilities will be critical to realize sustainable palm oil production and meet industry commitments to zero deforestation.

Managing Fire Risk During Drought: The Influence of Certification and El Nino on Fire-Driven Forest Conversion for Oil Palm in Southeast Asia

NASA Technical Reports Server (NTRS)

Noojipady, Praveen; Morton, Douglas C.; Schroeder, Wilfrid; Carlson, Kimberly M.; Huang, Chengquan; Gibbs, Holly K.; Burns, David; Walker, Nathalie F.; Prince, Stephen D.

2017-01-01

Indonesia and Malaysia have emerged as leading producers of palm oil in the past several decades, expanding production through the conversion of tropical forests to industrial plantations. Efforts to produce "sustainable" palm oil, including certification by the Roundtable on Sustainable Palm Oil (RSPO), include guidelines designed to reduce the environmental impact of palm oil production. Fire-driven deforestation is prohibited by law in both countries and a stipulation of RSPO certification, yet the degree of environmental compliance isunclear, especially during El Niño events when drought conditions increase fire risk. Here, we used time series of satellite data to estimate the spatial and temporal patterns of fire-driven deforestation on and around oil palm plantations. In Indonesia, fire-driven deforestation accounted for one-quarter of total forest losses on both certified and noncertified plantations. After the first plantations in Indonesia received RSPO certification in 2009,forest loss and fire-driven deforestation declined on certified plantations but did not stop altogether. Oil palm expansion in Malaysia rarely involved fire; only 5 % of forest loss on certified plantations had coincident activefire detections. Interannual variability in fire detections was strongly influenced by El Nino and the timing of certification. Fire activity during the 2002, 2004, and 2006 El Nino events was similar among oil palm plantations in Indonesia that would later become certified, noncertified plantations, and surrounding areas. However, total fire activity was 75% and 66% lower on certified plantations than noncertified plantations during the 2009 and 2015 El Nino events, respectively. The decline in fire activity on certified plantations, including during drought periods, highlights the potential for RSPO certification to safeguard carbon stocks in peatlands and remaining forests in accordance with legislation banning fires. However, aligning certification standards with satellite monitoring capabilities will be critical to realize sustainable palm oil production and meet industry commitments to zero forestation.

Smartphone applications to support weight loss: current perspectives

PubMed Central

Pellegrini, Christine A; Pfammatter, Angela F; Conroy, David E; Spring, Bonnie

2015-01-01

Lower cost alternatives are needed for the traditional in-person behavioral weight loss programs to overcome challenges of lowering the worldwide prevalence of overweight and obesity. Smartphones have become ubiquitous and provide a unique platform to aid in the delivery of a behavioral weight loss program. The technological capabilities of a smartphone may address certain limitations of a traditional weight loss program, while also reducing the cost and burden on participants, interventionists, and health care providers. Awareness of the advantages smartphones offer for weight loss has led to the rapid development and proliferation of weight loss applications (apps). The built-in features and the mechanisms by which they work vary across apps. Although there are an extraordinary number of a weight loss apps available, most lack the same magnitude of evidence-based behavior change strategies typically used in traditional programs. As features develop and new capabilities are identified, we propose a conceptual model as a framework to guide the inclusion of features that can facilitate behavior change and lead to reductions in weight. Whereas the conventional wisdom about behavior change asserts that more is better (with respect to the number of behavior change techniques involved), this model suggests that less may be more because extra techniques may add burden and adversely impact engagement. Current evidence is promising and continues to emerge on the potential of smartphone use within weight loss programs; yet research is unable to keep up with the rapidly improving smartphone technology. Future studies are needed to refine the conceptual model’s utility in the use of technology for weight loss, determine the effectiveness of intervention components utilizing smartphone technology, and identify novel and faster ways to evaluate the ever-changing technology. PMID:26236766

Hearing loss in the developing world: evaluating the iPhone mobile device as a screening tool.

PubMed

Peer, S; Fagan, J J

2015-01-01

Developing countries have the world's highest prevalence of hearing loss, and hearing screening programmes are scarce. Mobile devices such as smartphones have potential for audiometric testing. To evaluate the uHear app using an Apple iPhone as a possible hearing screening tool in the developing world, and to determine accuracy of certain hearing thresholds that could prove useful in early detection of hearing loss for high-risk populations in resource-poor communities. This was a quasi-experimental study design. Participants recruited from the Otolaryngology Clinic, Groote Schuur Hospital, Cape Town, South Africa, completed a uHear test in three settings--waiting room (WR), quiet roon (QR) and soundproof room (SR). Thresholds were compared with formal audiograms. Twenty-five patients were tested (50 ears). The uHear test detected moderate or worse hearing loss (pure-tone average (PTA) > 40 dB accurately with a sensitivity of 100% in all three environments. Specificity was 88% (SR), 73% (QR) and 68% (WR). Its was highly accurate in detecting high-frequency hearing loss (2 000, 4 000, 6 000 Hz) in the QR and SR with 'good' and 'very good' kappa values, showing statistical significance (p < 0.05). It was moderately accurate in low-frequency hearing loss (250, 500, 1 000 Hz) in the SR, and poor in the QR and WR. Using the iPhone, uHear is a feasible screening test to rule out significant hearing loss (PTA > 40 dB). It is highly sensitive for detecting threshold changes at high frequencies, making it reasonably well suited to detect presbycusis and ototoxic hearing loss from HIV, tuberculosis therapy and chemotherapy. Portability and ease of use make it appropriate to use in developing world communities that lack screening programmes.

Statistical Tests of Reliability of NDE

NASA Technical Reports Server (NTRS)

Baaklini, George Y.; Klima, Stanley J.; Roth, Don J.; Kiser, James D.

1987-01-01

Capabilities of advanced material-testing techniques analyzed. Collection of four reports illustrates statistical method for characterizing flaw-detecting capabilities of sophisticated nondestructive evaluation (NDE). Method used to determine reliability of several state-of-the-art NDE techniques for detecting failure-causing flaws in advanced ceramic materials considered for use in automobiles, airplanes, and space vehicles.

Autonomous power expert system advanced development

NASA Technical Reports Server (NTRS)

Quinn, Todd M.; Walters, Jerry L.

1991-01-01

The autonomous power expert (APEX) system is being developed at Lewis Research Center to function as a fault diagnosis advisor for a space power distribution test bed. APEX is a rule-based system capable of detecting faults and isolating the probable causes. APEX also has a justification facility to provide natural language explanations about conclusions reached during fault isolation. To help maintain the health of the power distribution system, additional capabilities were added to APEX. These capabilities allow detection and isolation of incipient faults and enable the expert system to recommend actions/procedure to correct the suspected fault conditions. New capabilities for incipient fault detection consist of storage and analysis of historical data and new user interface displays. After the cause of a fault is determined, appropriate recommended actions are selected by rule-based inferencing which provides corrective/extended test procedures. Color graphics displays and improved mouse-selectable menus were also added to provide a friendlier user interface. A discussion of APEX in general and a more detailed description of the incipient detection, recommended actions, and user interface developments during the last year are presented.

Integrated analysis of error detection and recovery

NASA Technical Reports Server (NTRS)

Shin, K. G.; Lee, Y. H.

1985-01-01

An integrated modeling and analysis of error detection and recovery is presented. When fault latency and/or error latency exist, the system may suffer from multiple faults or error propagations which seriously deteriorate the fault-tolerant capability. Several detection models that enable analysis of the effect of detection mechanisms on the subsequent error handling operations and the overall system reliability were developed. Following detection of the faulty unit and reconfiguration of the system, the contaminated processes or tasks have to be recovered. The strategies of error recovery employed depend on the detection mechanisms and the available redundancy. Several recovery methods including the rollback recovery are considered. The recovery overhead is evaluated as an index of the capabilities of the detection and reconfiguration mechanisms.

Molecules that inhibit growth of Fusarium graminearum, a pathogen causing disease in wheat and corn

USDA-ARS?s Scientific Manuscript database

Fusarium graminearum can cause head blight in wheat and stalk or ear rot in corn, which results in crop losses. Discovery of novel antifungal resistance proteins are crucial to mitigating crop losses. We found, via in vitro studies, a small cationic peptide was capable of inhibiting the growth of th...

Cortical brain connectivity evaluated by graph theory in dementia: a correlation study between functional and structural data.

PubMed

Vecchio, Fabrizio; Miraglia, Francesca; Curcio, Giuseppe; Altavilla, Riccardo; Scrascia, Federica; Giambattistelli, Federica; Quattrocchi, Carlo Cosimo; Bramanti, Placido; Vernieri, Fabrizio; Rossini, Paolo Maria

2015-01-01

A relatively new approach to brain function in neuroscience is the "functional connectivity", namely the synchrony in time of activity in anatomically-distinct but functionally-collaborating brain regions. On the other hand, diffusion tensor imaging (DTI) is a recently developed magnetic resonance imaging (MRI)-based technique with the capability to detect brain structural connection with fractional anisotropy (FA) identification. FA decrease has been observed in the corpus callosum of subjects with Alzheimer's disease (AD) and mild cognitive impairment (MCI, an AD prodromal stage). Corpus callosum splenium DTI abnormalities are thought to be associated with functional disconnections among cortical areas. This study aimed to investigate possible correlations between structural damage, measured by MRI-DTI, and functional abnormalities of brain integration, measured by characteristic path length detected in resting state EEG source activity (40 participants: 9 healthy controls, 10 MCI, 10 mild AD, 11 moderate AD). For each subject, undirected and weighted brain network was built to evaluate graph core measures. eLORETA lagged linear connectivity values were used as weight of the edges of the network. Results showed that callosal FA reduction is associated to a loss of brain interhemispheric functional connectivity characterized by increased delta and decreased alpha path length. These findings suggest that "global" (average network shortest path length representing an index of how efficient is the information transfer between two parts of the network) functional measure can reflect the reduction of fiber connecting the two hemispheres as revealed by DTI analysis and also anticipate in time this structural loss.

A universal DNA-based protein detection system.

PubMed

Tran, Thua N N; Cui, Jinhui; Hartman, Mark R; Peng, Songming; Funabashi, Hisakage; Duan, Faping; Yang, Dayong; March, John C; Lis, John T; Cui, Haixin; Luo, Dan

2013-09-25

Protein immune detection requires secondary antibodies which must be carefully selected in order to avoid interspecies cross-reactivity, and is therefore restricted by the limited availability of primary/secondary antibody pairs. Here we present a versatile DNA-based protein detection system using a universal adapter to interface between IgG antibodies and DNA-modified reporter molecules. As a demonstration of this capability, we successfully used DNA nano-barcodes, quantum dots, and horseradish peroxidase enzyme to detect multiple proteins using our DNA-based labeling system. Our system not only eliminates secondary antibodies but also serves as a novel method platform for protein detection with modularity, high capacity, and multiplexed capability.

A Universal DNA-Based Protein Detection System

PubMed Central

Tran, Thua N. N.; Cui, Jinhui; Hartman, Mark R.; Peng, Songming; Funabashi, Hisakage; Duan, Faping; Yang, Dayong; March, John C.; Lis, John T.; Cui, Haixin; Luo, Dan

2014-01-01

Protein immune detection requires secondary antibodies which must be carefully selected in order to avoid interspecies cross-reactivity, and is therefore restricted by the limited availability of primary/secondary antibody pairs. Here we present a versatile DNA-based protein detection system using a universal adapter to interface between IgG antibodies and DNA-modified reporter molecules. As a demonstration of this capability, we successfully used DNA nano-barcodes, quantum dots, and horseradish peroxidase enzyme to detect multiple proteins using our DNA-based labeling system. Our system not only eliminates secondary antibodies but also serves as a novel method platform for protein detection with modularity, high capacity, and multiplexed capability. PMID:23978265

Quantifying Standing Dead Tree Volume and Structural Loss with Voxelized Terrestrial Lidar Data

NASA Astrophysics Data System (ADS)

Popescu, S. C.; Putman, E.

2017-12-01

Standing dead trees (SDTs) are an important forest component and impact a variety of ecosystem processes, yet the carbon pool dynamics of SDTs are poorly constrained in terrestrial carbon cycling models. The ability to model wood decay and carbon cycling in relation to detectable changes in tree structure and volume over time would greatly improve such models. The overall objective of this study was to provide automated aboveground volume estimates of SDTs and automated procedures to detect, quantify, and characterize structural losses over time with terrestrial lidar data. The specific objectives of this study were: 1) develop an automated SDT volume estimation algorithm providing accurate volume estimates for trees scanned in dense forests; 2) develop an automated change detection methodology to accurately detect and quantify SDT structural loss between subsequent terrestrial lidar observations; and 3) characterize the structural loss rates of pine and oak SDTs in southeastern Texas. A voxel-based volume estimation algorithm, "TreeVolX", was developed and incorporates several methods designed to robustly process point clouds of varying quality levels. The algorithm operates on horizontal voxel slices by segmenting the slice into distinct branch or stem sections then applying an adaptive contour interpolation and interior filling process to create solid reconstructed tree models (RTMs). TreeVolX estimated large and small branch volume with an RMSE of 7.3% and 13.8%, respectively. A voxel-based change detection methodology was developed to accurately detect and quantify structural losses and incorporated several methods to mitigate the challenges presented by shifting tree and branch positions as SDT decay progresses. The volume and structural loss of 29 SDTs, composed of Pinus taeda and Quercus stellata, were successfully estimated using multitemporal terrestrial lidar observations over elapsed times ranging from 71 - 753 days. Pine and oak structural loss rates were characterized by estimating the amount of volumetric loss occurring in 20 equal-interval height bins of each SDT. Results showed that large pine snags exhibited more rapid structural loss in comparison to medium-sized oak snags in this study.

Improving the detectability and imaging capability of ground penetrating radar using novel antenna concepts

NASA Astrophysics Data System (ADS)

Koyadan Koroth, Ajith; Bhattacharya, Amitabha

2017-04-01

Antennas are key components of Ground Penetrating Radar (GPR) instrumentation. A carefully designed antenna can improve the detectability and imaging capability of a GPR to a great extent without changing the other instrumentations. In this work, we propose four different types of antennas for GPR. They are modifications of a conventional bowtie antenna with great improvement in performance parameters. The designed antennas has also been tested in a stepped frequency type GPR and two dimensional scan images of various targets are presented. Bowtie antennas have been traditionally employed in GPR for its wide impedance bandwidth and radiation properties. The researchers proposed resistive loading to improve the bandwidth of the bowtie antenna and for low ringing pulse radiation. But this method was detrimental for antenna gain and efficiency. Bowtie antennas have a very wide impedance bandwidth. But the useful bandwidth of the antenna has been limited by the radiation pattern bandwidth. The boresight gain of bowtie antennas are found to be unstable beyond a 4:1 bandwidth. In this work, these problems have been addressed and maximum usable bandwidth for the bowtie antennas has been achieved. In this work, four antennas have been designed: namely, 1.) RC loaded bowtie antennas, 2.) RC loaded bowtie with metamaterial lens, 3.) Loop loaded bowtie, 4.) Loop loaded bowtie with directors. The designed antennas were characterized for different parameters like impedance bandwidth, radiation pattern and, gain. In antenna 1, a combined resistive-capacitive loading has been applied by periodic slot cut on the arms of the bowtie and pasting a planar graphite sheet over it. Graphite having a less conductance compared to copper acts as resistive loading. This would minimize the losses compared to lumped resistive loading. The antenna had a 10:1 impedance bandwidth and, a 5:1 pattern bandwidth. In antenna 2, a metamaterial lens has been designed to augment the antenna 1, to improve the forward gain. This antenna had the same impedance bandwidth of 10:1 while pattern bandwidth has been raised to 7:1. In antenna 3, a loop loaded bowtie antenna has been designed. This antenna do not employ any kind of resistive loading, yet achieves an impedance bandwidth of 11:1 and also a usable bandwidth of 11:1. The antenna 4 employs concentric offset loops which acts as directors to improve the directivity. This antenna achieved an impedance bandwidth and a pattern bandwidth of 13:1. All the antennas have a maximum size of about 0.3λ at lowest operating frequency. An experimental stepped frequency type GPR has been constructed to study the suitability of the fabricated antennas in detecting buried targets. Four experiments have been conducted viz. 1.) To detect a metallic pipe of 1in diameter, 2.) To detect a metallic pipe of 2in diameter 3.) To detect dry bamboo, 3.) To detect rebar in concrete. The detectability and imaging capability of GPR has been found to be improving from antenna 1 to 4.

Thermodynamic framework to assess low abundance DNA mutation detection by hybridization

PubMed Central

Willems, Hanny; Jacobs, An; Hadiwikarta, Wahyu Wijaya; Venken, Tom; Valkenborg, Dirk; Van Roy, Nadine; Vandesompele, Jo; Hooyberghs, Jef

2017-01-01

The knowledge of genomic DNA variations in patient samples has a high and increasing value for human diagnostics in its broadest sense. Although many methods and sensors to detect or quantify these variations are available or under development, the number of underlying physico-chemical detection principles is limited. One of these principles is the hybridization of sample target DNA versus nucleic acid probes. We introduce a novel thermodynamics approach and develop a framework to exploit the specific detection capabilities of nucleic acid hybridization, using generic principles applicable to any platform. As a case study, we detect point mutations in the KRAS oncogene on a microarray platform. For the given platform and hybridization conditions, we demonstrate the multiplex detection capability of hybridization and assess the detection limit using thermodynamic considerations; DNA containing point mutations in a background of wild type sequences can be identified down to at least 1% relative concentration. In order to show the clinical relevance, the detection capabilities are confirmed on challenging formalin-fixed paraffin-embedded clinical tumor samples. This enzyme-free detection framework contains the accuracy and efficiency to screen for hundreds of mutations in a single run with many potential applications in molecular diagnostics and the field of personalised medicine. PMID:28542229

Numerical analysis of Eucalyptus grandis × E. urophylla heat-treatment: A dynamically detecting method of mass loss during the process

NASA Astrophysics Data System (ADS)

Zhao, Zijian; Ma, Qing; Mu, Jun; Yi, Songlin; He, Zhengbin

Eucalyptus particles, lamellas and boards were applied to explore a simply-implemented method with neglected heat and mass transfer to inspect the mass loss during the heat-treatment course. The results revealed that the mass loss of a certain period was theoretically the definite integration of loss rate to time in this period, and a monitoring model for mass loss speed was developed with the particles and validated with the lamellas and boards. The loss rate was correlated to the temperature and temperature-evolving speed in the model which was composed of three functions during different temperature-evolving period. The sample mass loss was calculated in the MATLAB for the lamellas and boards and the model was validated and adjusted based on the difference between the computed results and the practically measured loss values. The error ranges of the new models were -16.30% to 18.35% for wood lamellas and -9.86% to 6.80% for wood boards. This method made it possible to acquire the instantaneous loss value through continuously detecting the wood temperature evolution. This idea could provide a reference for the Eucalyptus heat-treatment to detect the treating course and control the final material characteristics.

Orbiting Debris: a Space Environmental Problem. Background Paper

NASA Technical Reports Server (NTRS)

1990-01-01

Artificial debris, deposited in a multitude of orbits about the Earth as the result of the exploration and use of the space environment, poses a growing hazard to future space operations. Unless nations sharply reduce the amount of orbital debris they produce, future space activites could suffer loss of capability, loss of income, and even loss of life as a result of collisions between spacecraft and debris. This background paper discusses the sources of debris and how they can be greatly reduced.

Capacitance-based damage detection sensing for aerospace structural composites

NASA Astrophysics Data System (ADS)

Bahrami, P.; Yamamoto, N.; Chen, Y.; Manohara, H.

2014-04-01

Damage detection technology needs improvement for aerospace engineering application because detection within complex composite structures is difficult yet critical to avoid catastrophic failure. Damage detection is challenging in aerospace structures because not all the damage detection technology can cover the various defect types (delamination, fiber fracture, matrix crack etc.), or conditions (visibility, crack length size, etc.). These defect states are expected to become even more complex with future introduction of novel composites including nano-/microparticle reinforcement. Currently, non-destructive evaluation (NDE) methods with X-ray, ultrasound, or eddy current have good resolutions (< 0.1 mm), but their detection capabilities is limited by defect locations and orientations and require massive inspection devices. System health monitoring (SHM) methods are often paired with NDE technologies to signal out sensed damage, but their data collection and analysis currently requires excessive wiring and complex signal analysis. Here, we present a capacitance sensor-based, structural defect detection technology with improved sensing capability. Thin dielectric polymer layer is integrated as part of the structure; the defect in the structure directly alters the sensing layer's capacitance, allowing full-coverage sensing capability independent of defect size, orientation or location. In this work, capacitance-based sensing capability was experimentally demonstrated with a 2D sensing layer consisting of a dielectric layer sandwiched by electrodes. These sensing layers were applied on substrate surfaces. Surface indentation damage (~1mm diameter) and its location were detected through measured capacitance changes: 1 to 250 % depending on the substrates. The damage detection sensors are light weight, and they can be conformably coated and can be part of the composite structure. Therefore it is suitable for aerospace structures such as cryogenic tanks and rocket fairings for example. The sensors can also be operating in space and harsh environment such as high temperature and vacuum.

Integrated System Health Management (ISHM) for Test Stand and J-2X Engine: Core Implementation

NASA Technical Reports Server (NTRS)

Figueroa, Jorge F.; Schmalzel, John L.; Aguilar, Robert; Shwabacher, Mark; Morris, Jon

2008-01-01

ISHM capability enables a system to detect anomalies, determine causes and effects, predict future anomalies, and provides an integrated awareness of the health of the system to users (operators, customers, management, etc.). NASA Stennis Space Center, NASA Ames Research Center, and Pratt & Whitney Rocketdyne have implemented a core ISHM capability that encompasses the A1 Test Stand and the J-2X Engine. The implementation incorporates all aspects of ISHM; from anomaly detection (e.g. leaks) to root-cause-analysis based on failure mode and effects analysis (FMEA), to a user interface for an integrated visualization of the health of the system (Test Stand and Engine). The implementation provides a low functional capability level (FCL) in that it is populated with few algorithms and approaches for anomaly detection, and root-cause trees from a limited FMEA effort. However, it is a demonstration of a credible ISHM capability, and it is inherently designed for continuous and systematic augmentation of the capability. The ISHM capability is grounded on an integrating software environment used to create an ISHM model of the system. The ISHM model follows an object-oriented approach: includes all elements of the system (from schematics) and provides for compartmentalized storage of information associated with each element. For instance, a sensor object contains a transducer electronic data sheet (TEDS) with information that might be used by algorithms and approaches for anomaly detection, diagnostics, etc. Similarly, a component, such as a tank, contains a Component Electronic Data Sheet (CEDS). Each element also includes a Health Electronic Data Sheet (HEDS) that contains health-related information such as anomalies and health state. Some practical aspects of the implementation include: (1) near real-time data flow from the test stand data acquisition system through the ISHM model, for near real-time detection of anomalies and diagnostics, (2) insertion of the J-2X predictive model providing predicted sensor values for comparison with measured values and use in anomaly detection and diagnostics, and (3) insertion of third-party anomaly detection algorithms into the integrated ISHM model.

Enhancing electrical energy storage capability of dielectric polymer nanocomposites via the room temperature Coulomb blockade effect of ultra-small platinum nanoparticles.

PubMed

Wang, Liwei; Huang, Xingyi; Zhu, Yingke; Jiang, Pingkai

2018-02-14

Introducing a high dielectric constant (high-k) nanofiller into a dielectric polymer is the most common way to achieve flexible nanocomposites for electrostatic energy storage devices. However, the significant decrease of breakdown strength and large increase of dielectric loss has long been known as the bottleneck restricting the enhancement of practical energy storage capability of the nanocomposites. In this study, by introducing ultra-small platinum (<2 nm) nanoparticles, high-k polymer nanocomposites with high breakdown strength and low dielectric loss were prepared successfully. Core-shell structured polydopamine@BaTiO 3 (PDA@BT) and core-satellite ultra-small platinum decorated PDA@BT (Pt@PDA@BT) were used as nanofillers. Compared with PDA@BT nanocomposites, the maximum discharged energy density of the Pt@PDA@BT nanocomposites is increased by nearly 70% because of the improved energy storage efficiency. This research provides a simple, promising and unique way to enhance energy storage capability of high-k polymer nanocomposites.

Physical frailty, sarcopenia, and the enablement of autonomy: philosophical issues in geriatric medicine.

PubMed

Blasimme, Alessandro

2017-02-01

Physical frailty and loss of muscular mass (sarcopenia) are believed to be predictors of age-related conditions, such as disability and loss of autonomy. In this paper, I show that what in political and moral philosophy has come to be known as "the capability approach" may indeed provide much needed conceptual clarification in the area of frailty research. Other than being useful at the theoretical level, the capability approach can definitely help in the implementation of clinical guidelines and public health measures aimed at translating the results that are accumulating from frailty research. I will first briefly review the main philosophical tenets of the capability approach, and then analyze how they relate to current debates about frailty and sarcopenia by introducing the notion of "enablement". Finally, I will show how my analysis bears on both clinical research in this domain and public policy aimed at tackling some of the age-related issues in an aging society.

On-Line Loss of Control Detection Using Wavelets

NASA Technical Reports Server (NTRS)

Brenner, Martin J. (Technical Monitor); Thompson, Peter M.; Klyde, David H.; Bachelder, Edward N.; Rosenthal, Theodore J.

2005-01-01

Wavelet transforms are used for on-line detection of aircraft loss of control. Wavelet transforms are compared with Fourier transform methods and shown to more rapidly detect changes in the vehicle dynamics. This faster response is due to a time window that decreases in length as the frequency increases. New wavelets are defined that further decrease the detection time by skewing the shape of the envelope. The wavelets are used for power spectrum and transfer function estimation. Smoothing is used to tradeoff the variance of the estimate with detection time. Wavelets are also used as front-end to the eigensystem reconstruction algorithm. Stability metrics are estimated from the frequency response and models, and it is these metrics that are used for loss of control detection. A Matlab toolbox was developed for post-processing simulation and flight data using the wavelet analysis methods. A subset of these methods was implemented in real time and named the Loss of Control Analysis Tool Set or LOCATS. A manual control experiment was conducted using a hardware-in-the-loop simulator for a large transport aircraft, in which the real time performance of LOCATS was demonstrated. The next step is to use these wavelet analysis tools for flight test support.

Internal seismological stations for monitoring a comprehensive test ban theory

NASA Astrophysics Data System (ADS)

Dahlman, O.; Israelson, H.

1980-06-01

Verification of the compliance with a Comprehensive Test Ban on nuclear explosions is expected to be carried out by a seismological verification system of some fifty globally distributed teleseismic stations designed to monitor underground explosions at large distances (beyond 2000 km). It is attempted to assess various technical purposes that such internal stations might serve in relation to a global network of seismological stations. The assessment is based on estimates of the detection capabilities of hypothetical networks of internal stations. Estimates pertaining to currently used detection techniques (P waves) indicate that a limited number (less than 30) of such stations would not improve significantly upon the detection capability that a global network of stations would have throughout the territories of the US and the USSR. Recently available and not yet fully analyzed data indicate however that very high detection capabilities might be obtained in certain regions.

A Kepler Mission, A Search for Habitable Planets: Concept, Capabilities and Strengths

NASA Technical Reports Server (NTRS)

Koch, David; Borucki, William; Lissauer, Jack; Dunham, Edward; Jenkins, Jon; DeVincenzi, D. (Technical Monitor)

1998-01-01

The detection of extrasolar terrestrial planets orbiting main-sequence stars is of great interest and importance. Current ground-based methods are only capable of detecting objects about the size or mass of Jupiter or larger. The technological challenges of direct imaging of Earth-size planets from space are expected to be resolved over the next twenty years. Spacebased photometry of planetary transits is currently the only viable method for detection of terrestrial planets (30-600 times less massive than Jupiter). The method searches the extended solar neighborhood, providing a statistically large sample and the detailed characteristics of each individual case. A robust concept has been developed and proposed as a Discovery-class mission. The concept, its capabilities and strengths are presented.

Dynamic malware analysis using IntroVirt: a modified hypervisor-based system

NASA Astrophysics Data System (ADS)

White, Joshua S.; Pape, Stephen R.; Meily, Adam T.; Gloo, Richard M.

2013-05-01

In this paper, we present a system for Dynamic Malware Analysis which incorporates the use of IntroVirt™. IntroVirt is an introspective hypervisor architecture and infrastructure that supports advanced analysis techniques for stealth-malwareanalysis. This system allows for complete guest monitoring and interaction, including the manipulation and blocking of system calls. IntroVirt is capable of bypassing virtual machine detection capabilities of even the most sophisticated malware, by spoofing returns to system call responses. Additional fuzzing capabilities can be employed to detect both malware vulnerabilities and polymorphism.

Vomeronasal and Olfactory Structures in Bats Revealed by DiceCT Clarify Genetic Evidence of Function

PubMed Central

Yohe, Laurel R.; Hoffmann, Simone; Curtis, Abigail

2018-01-01

The degree to which molecular and morphological loss of function occurs synchronously during the vestigialization of traits is not well understood. The mammalian vomeronasal system, a sense critical for mediating many social and reproductive behaviors, is highly conserved across mammals. New World Leaf-nosed bats (Phyllostomidae) are under strong selection to maintain a functional vomeronasal system such that most phyllostomids possess a distinct vomeronasal organ and an intact TRPC2, a gene encoding a protein primarily involved in vomeronasal sensory neuron signal transduction. Recent genetic evidence, however, shows that TRPC2 is a pseudogene in some Caribbean nectarivorous phyllostomids. The loss-of-function mutations suggest the sensory neural tissue of the vomeronasal organ is absent in these species despite strong selection on this gene in its mainland relatives, but the anatomy was unknown in most Caribbean nectarivorous phyllostomids until this study. We used diffusible iodine-based contrast-enhanced computed tomography (diceCT) to test whether the vomeronasal and main olfactory anatomy of several phyllostomid species matched genetic evidence of function, providing insight into whether loss of a structure is linked to pseudogenization of a molecular component of the system. The vomeronasal organ is indeed rudimentary or absent in species with a disrupted TRPC2 gene. Caribbean nectar-feeders also exhibit derived olfactory turbinal morphology and a large olfactory recess that differs from closely related bats that have an intact vomeronasal organ, which may hint that the main olfactory system may compensate for loss. We emphasize non-invasive diceCT is capable of detecting the vomeronasal organ, providing a feasible approach for quantifying mammalian chemosensory anatomy across species. PMID:29867373

Radiographic sclerotic contour loss in the identification of glenoid bone loss.

PubMed

Bornes, Troy D; Jaremko, Jacob L; Beaupre, Lauren A; Bouliane, Martin J

2016-07-01

Quantification of glenoid bone loss guides surgical management in the setting of anterior shoulder instability. Glenoid defects resulting in ≥20 % articular area loss require bony reconstruction. The objective of this study was to evaluate the utility of sclerotic glenoid contour loss on true anteroposterior radiography in the detection of varying quantities of simulated glenoid bone loss using a cadaveric model. Eight cadaveric scapulae with full radiographic sclerotic contour were osteotomized to produce glenoid surface area reductions of 10-50 %. Radiography was performed initially and following each osteotomy, and assessed by an orthopedic surgeon and radiologist twice. Quantity of glenoid loss was compared using Fisher's exact test. Sensitivity, specificity, and reliability analyses were performed. On the first radiographic review, sclerotic contour loss was detected in 6 out of 8 scapulae with 50 % area loss, but only 1 out of 8 scapulae with 20 % area loss. There was a significantly higher proportion of radiographs containing sclerotic contour loss for defects with 50 % area loss compared to those with 0-25 % loss (p ≤ 0.02). In the detection of ≥20 % area loss, sclerotic contour loss had a sensitivity of 33-43 % and specificity of 88-100 %. Moderate inter-observer reliability (Cohen's kappa value of 0.42-0.53) and intra-observer reliability (kappa value of 0.46-0.58) were found. Radiographic sclerotic contour loss is commonly observed in radiographs of scapulae with 40-50 % glenoid area loss and less often with smaller lesions. However, this finding lacks utility in discerning specific quantifications of glenoid bone loss. In a clinical setting, sclerotic contour loss suggests the presence of a large glenoid defect that may require bony reconstruction. However, an intact sclerotic contour does not rule out significant bone loss.

Detection and differentiation of coxiella burnetii in biological fluids

DOEpatents

Frazier, Marvin E.; Mallavia, Louis P.; Samuel, James E.; Baca, Oswald G.

1990-01-01

Methods for detecting the presence of Coxiella burenetii in biological samples, as well as a method for differentiating strains of C. burnetii that are capable of causing acute disease from those strains capable of causing chronic disease are disclosed. The methods generally comprise treating cells contained within the biological sample to expose cellular DNA, and hybridizing the cellular DNA (specifically rickettsial DNA) with a C. burnetii-specific labeled DNA probe. Radioisotope and biotin labels are preferred, allowing detection through autoradiography and colorimetric assays, respectively.

Detection and differentiation of coxiella burnetii in biological fluids

DOEpatents

Frazier, Marvin E.; Mallavia, Louis P.; Baca, Oswald G.; Samuel, James E.

1989-01-01

Methods for detecting the presence of Coxiella burnetii in biological samples, as well as a method for differentiating strains of C. burnetii that are capable of causing acute disease from those strains capable of causing chronic disease are disclosed. The methods generally comprise treating cells contained within the biological sample to expose cellular DNA, and hybridizing the cellular DNA (specifically rickettsial DNA) with a C. burnetii-specific labeled DNA probe. Radioisotope and biotin labels are preferred, allowing detection through autoradiography and colorimetric assays, respectively.

Direct detection of the optical field beyond single polarization mode.

PubMed

Che, Di; Sun, Chuanbowen; Shieh, William

2018-02-05

Direct detection is traditionally regarded as a detection method that recovers only the optical intensity. Compared with coherent detection, it owns a natural advantage-the simplicity-but lacks a crucial capability of field recovery that enables not only the multi-dimensional modulation, but also the digital compensation of the fiber impairments linear with the optical field. Full-field detection is crucial to increase the capacity-distance product of optical transmission systems. A variety of methods have been investigated to directly detect the optical field of the single polarization mode, which normally sends a carrier traveling with the signal for self-coherent detection. The crux, however, is that any optical transmission medium supports at least two propagating modes (e.g. single mode fiber supports two polarization modes), and until now there is no direct detection that can recover the complete set of optical fields beyond one polarization, due to the well-known carrier fading issue after mode demultiplexing induced by the random mode coupling. To avoid the fading, direct detection receivers should recover the signal in an intensity space isomorphic to the optical field without loss of any degrees of freedom, and a bridge should be built between the field and its isomorphic space for the multi-mode field recovery. Based on this thinking, we propose, for the first time, the direct detection of dual polarization modes by a novel receiver concept, the Stokes-space field receiver (SSFR) and its extension, the generalized SSFR for multiple spatial modes. The idea is verified by a dual-polarization field recovery of a polarization-multiplexed complex signal over an 80-km single mode fiber transmission. SSFR can be applied to a much wider range of fields beyond optical communications such as coherent sensing and imaging, where simple field recovery without an extra local laser is desired for enhanced system performance.

Recent Stirling engine loss-understanding results

NASA Technical Reports Server (NTRS)

Tew, Roy C.; Thieme, Lanny G.; Dudenhoefer, James E.

1990-01-01

For several years, NASA and other U.S. government agencies have been funding experimental and analytical efforts to improve the understanding of Stirling thermodynamic losses. NASA's objective is to improve Stirling engine design capability to support the development of new engines for space power. An overview of these efforts was last given at the 1988 IECEC. Recent results of this research are reviewed.

Four channel Laser Firing Unit using laser diodes

NASA Technical Reports Server (NTRS)

Rosner, David, Sr.; Spomer, Edwin, Sr.

1994-01-01

This paper describes the accomplishments and status of PS/EDD's (Pacific Scientific/Energy Dynamics Division) internal research and development effort to prototype and demonstrate a practical four channel laser firing unit (LFU) that uses laser diodes to initiate pyrotechnic events. The LFU individually initiates four ordnance devices using the energy from four diode lasers carried over the fiber optics. The LFU demonstrates end-to-end optical built in test (BIT) capabilities. Both Single Fiber Reflective BIT and Dual Fiber Reflective BIT approaches are discussed and reflection loss data is presented. This paper includes detailed discussions of the advantages and disadvantages of both BIT approaches, all-fire and no-fire levels, and BIT detection levels. The following topics are also addressed: electronic control and BIT circuits, fiber optic sizing and distribution, and an electromechanical shutter type safe/arm device. This paper shows the viability of laser diode initiation systems and single fiber BIT for typing military applications.

Heavy Ion Fragmentation Experiments at the Bevatron

NASA Technical Reports Server (NTRS)

Heckman, H. H.

1975-01-01

Fragmentation processes of heavy nuclei in matter using the heavy-ion capability of the Bevatron were studied. The purpose was to obtain the single particle inclusive spectra of secondary nuclei produced at 0 deg by the fragmentation of heavy ion beam projectiles. The process being examined is B+T yields F + anything, where B is the beam nucleus, T is the target nucleus, and F is the detected fragment. The fragments F are isotopically identified by experimental procedures involving magnetic analysis, energy loss and time-of-flight measurements. Attempts were also made to: (1) measure the total and partial production cross section for all isotopes, (2) test the applicability of high-energy multi-particle interaction theory to nuclear fragmentation, (3) apply the cross-section data and fragmentation probabilities to cosmic ray transport theory, and (4) search for systematic behavior of fragment production as a means to improve existing semi-empirical theories of cross sections.

Inferring Meal Eating Activities in Real World Settings from Ambient Sounds: A Feasibility Study

PubMed Central

Thomaz, Edison; Zhang, Cheng; Essa, Irfan; Abowd, Gregory D.

2015-01-01

Dietary self-monitoring has been shown to be an effective method for weight-loss, but it remains an onerous task despite recent advances in food journaling systems. Semi-automated food journaling can reduce the effort of logging, but often requires that eating activities be detected automatically. In this work we describe results from a feasibility study conducted in-the-wild where eating activities were inferred from ambient sounds captured with a wrist-mounted device; twenty participants wore the device during one day for an average of 5 hours while performing normal everyday activities. Our system was able to identify meal eating with an F-score of 79.8% in a person-dependent evaluation, and with 86.6% accuracy in a person-independent evaluation. Our approach is intended to be practical, leveraging off-the-shelf devices with audio sensing capabilities in contrast to systems for automated dietary assessment based on specialized sensors. PMID:25859566

Dust and Debris Tolerant Retractable Cover Connector

NASA Technical Reports Server (NTRS)

Lewis, Mark E. (Inventor); Dokos, Adam G. (Inventor); Townsend, III, Ivan I. (Inventor); Carlson, Jeffrey W. (Inventor); Bastin, Gary L. (Inventor); Murtland, Kevin A. (Inventor)

2017-01-01

A debris exclusion and removal apparatus for connectors which have retractable cover configurations which include internal wafers that clean the connectors prior to mating. XXXX connectors. More particularly, embodiments relate to dust tolerant connectors. Some embodiments also relate to an intelligent connector system capable of detecting damage to or faults within a conductor and then rerouting the energy to a non-damaged spare conductor. Discussion Connectors of the present invention may be used to transfer electrical current, fluid, and gas in a wide variety of environments containing dust and other debris, wherein that debris may present substantial challenges. For example, lunar/Martian dust intrusion and/or accumulation in connectors used to transfer oxygen, hydrogen, nitrogen, etc., may lead to larger system failures as well as loss of life in extraterrestrial human exploration endeavors. Additionally, embodiments of the present invention may also be suitable for use where connectors must resist water intrusion, such as terrestrial deep water operations.

A digital acquisition and elaboration system for nuclear fast pulse detection

NASA Astrophysics Data System (ADS)

Esposito, B.; Riva, M.; Marocco, D.; Kaschuck, Y.

2007-03-01

A new digital acquisition and elaboration system has been developed and assembled in ENEA-Frascati for the direct sampling of fast pulses from nuclear detectors such as scintillators and diamond detectors. The system is capable of performing the digital sampling of the pulses (200 MSamples/s, 14-bit) and the simultaneous (compressed) data transfer for further storage and software elaboration. The design (FPGA-based) is oriented to real-time applications and has been developed in order to allow acquisition with no loss of pulses and data storage for long-time intervals (tens of s at MHz pulse count rates) without the need of large on-board memory. A dedicated pulse analysis software, written in LabVIEWTM, performs the treatment of the acquired pulses, including pulse recognition, pile-up rejection, baseline removal, pulse shape particle separation and pulse height spectra analysis. The acquisition and pre-elaboration programs have been fully integrated with the analysis software.

Remote Sensing Laboratory - RSL

ScienceCinema

None

2018-01-16

One of the primary resources supporting homeland security is the Remote Sensing Laboratory, or RSL. The Laboratory creates advanced technologies for emergency response operations, radiological incident response, and other remote sensing activities. RSL emergency response teams are on call 24-hours a day, and maintain the capability to deploy domestically and internationally in response to threats involving the loss, theft, or release of nuclear or radioactive material. Such incidents might include Nuclear Power Plant accidents, terrorist incidents involving nuclear or radiological materials, NASA launches, and transportation accidents involving nuclear materials. Working with the US Department of Homeland Security, RSL personnel equip, maintain, and conduct training on the mobile detection deployment unit, to provide nuclear radiological security at major national events such as the super bowl, the Indianapolis 500, New Year's Eve celebrations, presidential inaugurations, international meetings and conferences, just about any event where large numbers of people will gather.

A Family of Well-Clear Boundary Models for the Integration of UAS in the NAS

NASA Technical Reports Server (NTRS)

Munoz, Cesar A.; Narkawicz, Anthony; Chamberlain, James; Consiglio, Maria; Upchurch, Jason

2014-01-01

The FAA-sponsored Sense and Avoid Workshop for Unmanned Aircraft Systems (UAS) defines the concept of sense and avoid for remote pilots as "the capability of a UAS to remain well clear from and avoid collisions with other airborne traffic." Hence, a rigorous definition of well clear is fundamental to any separation assurance concept for the integration of UAS into civil airspace. This paper presents a family of well-clear boundary models based on the TCAS II Resolution Advisory logic. For these models, algorithms that predict well-clear violations along aircraft current trajectories are provided. These algorithms are analogous to conflict detection algorithms but instead of predicting loss of separation, they predict whether well-clear violations will occur during a given lookahead time interval. Analytical techniques are used to study the properties and relationships satisfied by the models.

Continuous high speed coherent one-way quantum key distribution.

PubMed

Stucki, Damien; Barreiro, Claudio; Fasel, Sylvain; Gautier, Jean-Daniel; Gay, Olivier; Gisin, Nicolas; Thew, Rob; Thoma, Yann; Trinkler, Patrick; Vannel, Fabien; Zbinden, Hugo

2009-08-03

Quantum key distribution (QKD) is the first commercial quantum technology operating at the level of single quanta and is a leading light for quantum-enabled photonic technologies. However, controlling these quantum optical systems in real world environments presents significant challenges. For the first time, we have brought together three key concepts for future QKD systems: a simple high-speed protocol; high performance detection; and integration both, at the component level and for standard fibre network connectivity. The QKD system is capable of continuous and autonomous operation, generating secret keys in real time. Laboratory and field tests were performed and comparisons made with robust InGaAs avalanche photodiodes and superconducting detectors. We report the first real world implementation of a fully functional QKD system over a 43 dB-loss (150 km) transmission line in the Swisscom fibre optic network where we obtained average real-time distribution rates over 3 hours of 2.5 bps.

Remote Sensing Laboratory - RSL

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

None

2014-11-06

One of the primary resources supporting homeland security is the Remote Sensing Laboratory, or RSL. The Laboratory creates advanced technologies for emergency response operations, radiological incident response, and other remote sensing activities. RSL emergency response teams are on call 24-hours a day, and maintain the capability to deploy domestically and internationally in response to threats involving the loss, theft, or release of nuclear or radioactive material. Such incidents might include Nuclear Power Plant accidents, terrorist incidents involving nuclear or radiological materials, NASA launches, and transportation accidents involving nuclear materials. Working with the US Department of Homeland Security, RSL personnel equip,more » maintain, and conduct training on the mobile detection deployment unit, to provide nuclear radiological security at major national events such as the super bowl, the Indianapolis 500, New Year's Eve celebrations, presidential inaugurations, international meetings and conferences, just about any event where large numbers of people will gather.« less

The video ocular counter-roll (vOCR): a clinical test to detect loss of otolith-ocular function

PubMed Central

Otero-Millan, Jorge; Treviño, Carolina; Winnick, Ariel; Zee, David S.; Carey, John P.; Kheradmand, Amir

2017-01-01

Conclusion vOCR can detect loss of otolith-ocular function without specifying the side of vestibular loss. Since vOCR is measured with a simple head tilt maneuver, it can be potentially used as a bedside clinical test in combination with video head impulse test. Objective Video-oculography (VOG) goggles are being integrated into the bedside assessment of patients with vestibular disorders. Lacking, however, is a method to evaluate otolith function. This study validated a VOG test for loss of otolith function. Methods VOG was used to measure ocular counter-roll (vOCR) in 12 healthy controls, 14 patients with unilateral vestibular loss (UVL), and six patients with bilateral vestibular loss (BVL) with a static lateral head tilt of 30°. The results were compared with vestibular evoked myogenic potentials (VEMP), a widely-used laboratory test of otolith function. Results The average vOCR for healthy controls (4.6°) was significantly different from UVL (2.7°) and BVL (1.6°) patients (p < 0.0001). The vOCR and VEMP measurements were correlated across subjects, especially the click and tap oVEMPs (click oVEMP R = 0.45, tap oVEMP R = 0.51; p < 0.0003). The receiver operator characteristic (ROC) analysis showed that vOCR and VEMPs detected loss of otolith function equally well. The best threshold for vOCR to detect vestibular loss was at 3°. The vOCR values from the side of vestibular loss and the healthy side were not different in UVL patients (2.53° vs 2.8°; p = 0.59). PMID:28084887

Anomaly Detection in Power Quality at Data Centers

NASA Technical Reports Server (NTRS)

Grichine, Art; Solano, Wanda M.

2015-01-01

The goal during my internship at the National Center for Critical Information Processing and Storage (NCCIPS) is to implement an anomaly detection method through the StruxureWare SCADA Power Monitoring system. The benefit of the anomaly detection mechanism is to provide the capability to detect and anticipate equipment degradation by monitoring power quality prior to equipment failure. First, a study is conducted that examines the existing techniques of power quality management. Based on these findings, and the capabilities of the existing SCADA resources, recommendations are presented for implementing effective anomaly detection. Since voltage, current, and total harmonic distortion demonstrate Gaussian distributions, effective set-points are computed using this model, while maintaining a low false positive count.

Atomic layer deposition and characterization of hafnium oxide grown on silicon from tetrakis(diethylamino)hafnium and water vapor

NASA Astrophysics Data System (ADS)

Deshpande, Anand; Inman, Ronald; Jursich, Gregory; Takoudis, Christos

2004-09-01

In this work thin films of hafnium oxide are deposited on Si(100) substrates by means of atomic layer deposition (ALD) using tetrakis(diethylamino)hafnium and water vapor at substrate temperatures of 250-350ºC. Our system capabilities include fast transient delivery of reactive fluids, real-time vapor phase detection (in situ tunable diode laser hygrometer), precursor thermochemical capabilities, and ppt level elemental analysis by inductive coupling plasma mass spectrometry. The composition, purity, and other properties of the films and resulting interfaces are determined using x-ray and Fourier transform infrared spectroscopies, Z-contrast imaging and electron energy loss spectroscopy in a scanning transmission electron microscope with A˚ scale resolution, and spectroscopic ellipsometry. The observed ALD rate is ~1.4 A˚ per cycle. The nonuniformity across the film is less than 4%. Negligible carbon contamination is found in the resulting stoichiometric films under all conditions studied. The pulse sequence was optimized to prevent disastrous particulate problems while still minimizing purge times. The film deposition is investigated as a function of substrate temperature and reagent pulsing characteristics. A mild inverse temperature dependence of the ALD rate is observed. The initial stage of the HfO2 growth is investigated in detail.

A soft robot capable of 2D mobility and self-sensing for obstacle detection and avoidance

NASA Astrophysics Data System (ADS)

Qin, Lei; Tang, Yucheng; Gupta, Ujjaval; Zhu, Jian

2018-04-01

Soft robots have shown great potential for surveillance applications due to their interesting attributes including inherent flexibility, extreme adaptability, and excellent ability to move in confined spaces. High mobility combined with the sensing systems that can detect obstacles plays a significant role in performing surveillance tasks. Extensive studies have been conducted on movement mechanisms of traditional hard-bodied robots to increase their mobility. However, there are limited efforts in the literature to explore the mobility of soft robots. In addition, little attempt has been made to study the obstacle-detection capability of a soft mobile robot. In this paper, we develop a soft mobile robot capable of high mobility and self-sensing for obstacle detection and avoidance. This robot, consisting of a dielectric elastomer actuator as the robot body and four electroadhesion actuators as the robot feet, can generate 2D mobility, i.e. translations and turning in a 2D plane, by programming the actuation sequence of the robot body and feet. Furthermore, we develop a self-sensing method which models the robot body as a deformable capacitor. By measuring the real-time capacitance of the robot body, the robot can detect an obstacle when the peak capacitance drops suddenly. This sensing method utilizes the robot body itself instead of external sensors to achieve detection of obstacles, which greatly reduces the weight and complexity of the robot system. The 2D mobility and self-sensing capability ensure the success of obstacle detection and avoidance, which paves the way for the development of lightweight and intelligent soft mobile robots.

Detection capability of the IMS seismic network based on ambient seismic noise measurements

NASA Astrophysics Data System (ADS)

Gaebler, Peter J.; Ceranna, Lars

2016-04-01

All nuclear explosions - on the Earth's surface, underground, underwater or in the atmosphere - are banned by the Comprehensive Nuclear-Test-Ban Treaty (CTBT). As part of this treaty, a verification regime was put into place to detect, locate and characterize nuclear explosion testings at any time, by anyone and everywhere on the Earth. The International Monitoring System (IMS) plays a key role in the verification regime of the CTBT. Out of the different monitoring techniques used in the IMS, the seismic waveform approach is the most effective technology for monitoring nuclear underground testing and to identify and characterize potential nuclear events. This study introduces a method of seismic threshold monitoring to assess an upper magnitude limit of a potential seismic event in a certain given geographical region. The method is based on ambient seismic background noise measurements at the individual IMS seismic stations as well as on global distance correction terms for body wave magnitudes, which are calculated using the seismic reflectivity method. From our investigations we conclude that a global detection threshold of around mb 4.0 can be achieved using only stations from the primary seismic network, a clear latitudinal dependence for the detection threshold can be observed between northern and southern hemisphere. Including the seismic stations being part of the auxiliary seismic IMS network results in a slight improvement of global detection capability. However, including wave arrivals from distances greater than 120 degrees, mainly PKP-wave arrivals, leads to a significant improvement in average global detection capability. In special this leads to an improvement of the detection threshold on the southern hemisphere. We further investigate the dependence of the detection capability on spatial (latitude and longitude) and temporal (time) parameters, as well as on parameters such as source type and percentage of operational IMS stations.

Hundreds of conserved non-coding genomic regions are independently lost in mammals

PubMed Central

Hiller, Michael; Schaar, Bruce T.; Bejerano, Gill

2012-01-01

Conserved non-protein-coding DNA elements (CNEs) often encode cis-regulatory elements and are rarely lost during evolution. However, CNE losses that do occur can be associated with phenotypic changes, exemplified by pelvic spine loss in sticklebacks. Using a computational strategy to detect complete loss of CNEs in mammalian genomes while strictly controlling for artifacts, we find >600 CNEs that are independently lost in at least two mammalian lineages, including a spinal cord enhancer near GDF11. We observed several genomic regions where multiple independent CNE loss events happened; the most extreme is the DIAPH2 locus. We show that CNE losses often involve deletions and that CNE loss frequencies are non-uniform. Similar to less pleiotropic enhancers, we find that independently lost CNEs are shorter, slightly less constrained and evolutionarily younger than CNEs without detected losses. This suggests that independently lost CNEs are less pleiotropic and that pleiotropic constraints contribute to non-uniform CNE loss frequencies. We also detected 35 CNEs that are independently lost in the human lineage and in other mammals. Our study uncovers an interesting aspect of the evolution of functional DNA in mammalian genomes. Experiments are necessary to test if these independently lost CNEs are associated with parallel phenotype changes in mammals. PMID:23042682

ELENA MCP detector: absolute detection efficiency for low-energy neutral atoms

NASA Astrophysics Data System (ADS)

Rispoli, R.; De Angelis, E.; Colasanti, L.; Vertolli, N.; Orsini, S.; Scheer, J. A.; Mura, A.; Milillo, A.; Wurz, P.; Selci, S.; Di Lellis, A. M.; Leoni, R.; D'Alessandro, M.; Mattioli, F.; Cibella, S.

2012-09-01

Microchannel Plates (MCP) detectors are frequently used in space instrumentation for detecting a wide range of radiation and particles. In particular, the capability to detect non-thermal low energy neutral species is crucial for the sensor ELENA (Emitted Low-Energy Neutral Atoms), part of the package SERENA (Search for Exospheric Refilling and Emitted Natural Abundances) on board the BepiColombo mission of ESA to Mercury to be launched in 2015. ELENA is a Time of Flight (TOF) sensor, based on a novel concept using an ultra-sonic oscillating shutter (Start section), which is operated at frequencies up to 50 kHz; a MCP detector is used as a Stop detector. The scientific objective of ELENA is to detect energetic neutral atoms in the range 10 eV - 5 keV, within 76° FOV, perpendicular to the S/C orbital plane. ELENA will monitor the emission of neutral atoms from the whole surface of Mercury thanks to the spacecraft motion. The major scientific objectives are the interaction between the plasma environment and the planet’s surface, the global particle loss-rate and the remote sensing of the surface properties. In particular, surface release processes are investigated by identifying particles released from the surface, via solar wind-induced ion sputtering (< 1eV - < 100 eV) as well as Hydrogen back-scattered at hundreds eV. MCP absolute detection efficiency for very low energy neutral atoms (E < 30 eV) is a crucial point for this investigation. At the MEFISTO facility of the Physical Institute of the University of Bern (CH), measurements on three different types of MCP (with and without coating) have been performed providing the detection efficiencies in the energy range 10eV - 1keV. Outcomes from such measurements are discussed here.

Automated detection and differentiation of drusen, exudates, and cotton-wool spots in digital color fundus photographs for diabetic retinopathy diagnosis.

PubMed

Niemeijer, Meindert; van Ginneken, Bram; Russell, Stephen R; Suttorp-Schulten, Maria S A; Abràmoff, Michael D

2007-05-01

To describe and evaluate a machine learning-based, automated system to detect exudates and cotton-wool spots in digital color fundus photographs and differentiate them from drusen, for early diagnosis of diabetic retinopathy. Three hundred retinal images from one eye of 300 patients with diabetes were selected from a diabetic retinopathy telediagnosis database (nonmydriatic camera, two-field photography): 100 with previously diagnosed bright lesions and 200 without. A machine learning computer program was developed that can identify and differentiate among drusen, (hard) exudates, and cotton-wool spots. A human expert standard for the 300 images was obtained by consensus annotation by two retinal specialists. Sensitivities and specificities of the annotations on the 300 images by the automated system and a third retinal specialist were determined. The system achieved an area under the receiver operating characteristic (ROC) curve of 0.95 and sensitivity/specificity pairs of 0.95/0.88 for the detection of bright lesions of any type, and 0.95/0.86, 0.70/0.93, and 0.77/0.88 for the detection of exudates, cotton-wool spots, and drusen, respectively. The third retinal specialist achieved pairs of 0.95/0.74 for bright lesions and 0.90/0.98, 0.87/0.98, and 0.92/0.79 per lesion type. A machine learning-based, automated system capable of detecting exudates and cotton-wool spots and differentiating them from drusen in color images obtained in community based diabetic patients has been developed and approaches the performance level of retinal experts. If the machine learning can be improved with additional training data sets, it may be useful for detecting clinically important bright lesions, enhancing early diagnosis, and reducing visual loss in patients with diabetes.

Deep sub-wavelength metrology for advanced defect classification

NASA Astrophysics Data System (ADS)

van der Walle, P.; Kramer, E.; van der Donck, J. C. J.; Mulckhuyse, W.; Nijsten, L.; Bernal Arango, F. A.; de Jong, A.; van Zeijl, E.; Spruit, H. E. T.; van den Berg, J. H.; Nanda, G.; van Langen-Suurling, A. K.; Alkemade, P. F. A.; Pereira, S. F.; Maas, D. J.

2017-06-01

Particle defects are important contributors to yield loss in semi-conductor manufacturing. Particles need to be detected and characterized in order to determine and eliminate their root cause. We have conceived a process flow for advanced defect classification (ADC) that distinguishes three consecutive steps; detection, review and classification. For defect detection, TNO has developed the Rapid Nano (RN3) particle scanner, which illuminates the sample from nine azimuth angles. The RN3 is capable of detecting 42 nm Latex Sphere Equivalent (LSE) particles on XXX-flat Silicon wafers. For each sample, the lower detection limit (LDL) can be verified by an analysis of the speckle signal, which originates from the surface roughness of the substrate. In detection-mode (RN3.1), the signal from all illumination angles is added. In review-mode (RN3.9), the signals from all nine arms are recorded individually and analyzed in order to retrieve additional information on the shape and size of deep sub-wavelength defects. This paper presents experimental and modelling results on the extraction of shape information from the RN3.9 multi-azimuth signal such as aspect ratio, skewness, and orientation of test defects. Both modeling and experimental work confirm that the RN3.9 signal contains detailed defect shape information. After review by RN3.9, defects are coarsely classified, yielding a purified Defect-of-Interest (DoI) list for further analysis on slower metrology tools, such as SEM, AFM or HIM, that provide more detailed review data and further classification. Purifying the DoI list via optical metrology with RN3.9 will make inspection time on slower review tools more efficient.

Java Architecture for Detect and Avoid Extensibility and Modeling

NASA Technical Reports Server (NTRS)

Santiago, Confesor; Mueller, Eric Richard; Johnson, Marcus A.; Abramson, Michael; Snow, James William

2015-01-01

Unmanned aircraft will equip with a detect-and-avoid (DAA) system that enables them to comply with the requirement to "see and avoid" other aircraft, an important layer in the overall set of procedural, strategic and tactical separation methods designed to prevent mid-air collisions. This paper describes a capability called Java Architecture for Detect and Avoid Extensibility and Modeling (JADEM), developed to prototype and help evaluate various DAA technological requirements by providing a flexible and extensible software platform that models all major detect-and-avoid functions. Figure 1 illustrates JADEM's architecture. The surveillance module can be actual equipment on the unmanned aircraft or simulators that model the process by which sensors on-board detect other aircraft and provide track data to the traffic display. The track evaluation function evaluates each detected aircraft and decides whether to provide an alert to the pilot and its severity. Guidance is a combination of intruder track information, alerting, and avoidance/advisory algorithms behind the tools shown on the traffic display to aid the pilot in determining a maneuver to avoid a loss of well clear. All these functions are designed with a common interface and configurable implementation, which is critical in exploring DAA requirements. To date, JADEM has been utilized in three computer simulations of the National Airspace System, three pilot-in-the-loop experiments using a total of 37 professional UAS pilots, and two flight tests using NASA's Predator-B unmanned aircraft, named Ikhana. The data collected has directly informed the quantitative separation standard for "well clear", safety case, requirements development, and the operational environment for the DAA minimum operational performance standards. This work was performed by the Separation Assurance/Sense and Avoid Interoperability team under NASA's UAS Integration in the NAS project.

Weather and climate

NASA Technical Reports Server (NTRS)

1975-01-01

Recommendations for using space observations of weather and climate to aid in solving earth based problems are given. Special attention was given to: (1) extending useful forecasting capability of space systems, (2) reducing social, economic, and human losses caused by weather, (3) development of space system capability to manage and control air pollutant concentrations, and (4) establish mechanisms for the national examination of deliberate and inadvertent means for modifying weather and climate.

Analysis of Measurements for Solid State Lidar Development

NASA Technical Reports Server (NTRS)

Amzajerdian, Farzin

1996-01-01

A Detector Characterization Facility (DCF), capable of measuring 2-micron detection devices and evaluating heterodyne receivers, was developed at the Marshall Space Flight Center. The DCF is capable of providing all the necessary detection parameters for design, development, and calibration of coherent and incoherent solid state laser radar (lidar) systems. The coherent lidars in particular require an accurate knowledge of detector heterodyne quantum efficient, nonlinearity properties, and voltage-current relationship as a function of applied optical power. At present, no detector manufacturer provides these qualities or adequately characterizes their detectors for heterodyne detection operation. In addition, the detector characterization facility measures the detectors DC and AC quantum efficiencies noise equivalent power and frequency response up to several GHz. The DCF is also capable of evaluating various heterodyne detection schemes such as balanced detectors and fiber optic interferometers. The design and analyses of measurements for the DCF were preformed over the previous year and a detailed description of its design and capabilities was provided in the NASA report NAS8-38609/DO77. It should also be noted that the DCF design was further improved to allow for the characterization of diffractive andholographical optical elements and other critical components of coherent lidar systems.

Implications of Delay in Detection and Management of Deafness.

ERIC Educational Resources Information Center

Ross, Mark

1990-01-01

This article explores the rationale for early detection and management of children with significant hearing loss. Topics covered include attitudes toward hearing loss, monaural and binaural auditory sensory deprivation, auditory self-monitoring, and value of early intervention on linguistic and psychosocial development. (Author/DB)

Correlates of rediscovery and the detectability of extinction in mammals

PubMed Central

Fisher, Diana O.; Blomberg, Simon P.

2011-01-01

Extinction is difficult to detect, even in well-known taxa such as mammals. Species with long gaps in their sighting records, which might be considered possibly extinct, are often rediscovered. We used data on rediscovery rates of missing mammals to test whether extinction from different causes is equally detectable and to find which traits affect the probability of rediscovery. We find that species affected by habitat loss were much more likely to be misclassified as extinct or to remain missing than those affected by introduced predators and diseases, or overkill, unless they had very restricted distributions. We conclude that extinctions owing to habitat loss are most difficult to detect; hence, impacts of habitat loss on extinction have probably been overestimated, especially relative to introduced species. It is most likely that the highest rates of rediscovery will come from searching for species that have gone missing during the 20th century and have relatively large ranges threatened by habitat loss, rather than from additional effort focused on charismatic missing species. PMID:20880890

Visible and UV photo-detection in ZnO nanostructured thin films via simple tuning of solution method.

PubMed

Khokhra, Richa; Bharti, Bandna; Lee, Heung-No; Kumar, Rajesh

2017-11-08

This study demonstrates significant visible light photo-detection capability of pristine ZnO nanostructure thin films possessing substantially high percentage of oxygen vacancies [Formula: see text] and zinc interstitials [Formula: see text], introduced by simple tuning of economical solution method. The demonstrated visible light photo-detection capability, in addition to the inherent UV light detection ability of ZnO, shows great dependency of [Formula: see text] and [Formula: see text] with the nanostructure morphology. The dependency was evaluated by analyzing the presence/percentage of [Formula: see text] and [Formula: see text] using photoluminescence (PL) and X-ray photoelectron spectroscopy (XPS) measurements. Morphologies of ZnO viz. nanoparticles (NPs), nanosheets (NSs) and nanoflowers (NFs), as a result of tuning of synthesis method contended different concentrations of defects, demonstrated different photo-detection capabilities in the form of a thin film photodetector. The photo-detection capability was investigated under different light excitations (UV; 380~420 nm, white ; λ > 420 nm and green; 490~570 nm). The as fabricated NSs photodetector possessing comparatively intermediate percentage of [Formula: see text] ~ 47.7% and [Formula: see text] ~ 13.8% exhibited superior performance than that of NPs and NFs photodetectors, and ever reported photodetectors fabricated by using pristine ZnO nanostructures in thin film architecture. The adopted low cost and simplest approach makes the pristine ZnO-NSs applicable for wide-wavelength applications in optoelectronic devices.

Sensitivity to synchronicity of biological motion in normal and amblyopic vision

PubMed Central

Luu, Jennifer Y.; Levi, Dennis M.

2017-01-01

Amblyopia is a developmental disorder of spatial vision that results from abnormal early visual experience usually due to the presence of strabismus, anisometropia, or both strabismus and anisometropia. Amblyopia results in a range of visual deficits that cannot be corrected by optics because the deficits reflect neural abnormalities. Biological motion refers to the motion patterns of living organisms, and is normally displayed as points of lights positioned at the major joints of the body. In this experiment, our goal was twofold. We wished to examine whether the human visual system in people with amblyopia retained the higher-level processing capabilities to extract visual information from the synchronized actions of others, therefore retaining the ability to detect biological motion. Specifically, we wanted to determine if the synchronized interaction of two agents performing a dancing routine allowed the amblyopic observer to use the actions of one agent to predict the expected actions of a second agent. We also wished to establish whether synchronicity sensitivity (detection of synchronized versus desynchronized interactions) is impaired in amblyopic observers relative to normal observers. The two aims are differentiated in that the first aim looks at whether synchronized actions result in improved expected action predictions while the second aim quantitatively compares synchronicity sensitivity, or the ratio of desynchronized to synchronized detection sensitivities, to determine if there is a difference between normal and amblyopic observers. Our results show that the ability to detect biological motion requires more samples in both eyes of amblyopes than in normal control observers. The increased sample threshold is not the result of low-level losses but may reflect losses in feature integration due to undersampling in the amblyopic visual system. However, like normal observers, amblyopes are more sensitive to synchronized versus desynchronized interactions, indicating that higher-level processing of biological motion remains intact. We also found no impairment in synchronicity sensitivity in the amblyopic visual system relative to the normal visual system. Since there is no impairment in synchronicity sensitivity in either the nonamblyopic or amblyopic eye of amblyopes, our results suggest that the higher order processing of biological motion is intact. PMID:23474301

Combined hostile fire and optics detection

NASA Astrophysics Data System (ADS)

Brännlund, Carl; Tidström, Jonas; Henriksson, Markus; Sjöqvist, Lars

2013-10-01

Snipers and other optically guided weapon systems are serious threats in military operations. We have studied a SWIR (Short Wave Infrared) camera-based system with capability to detect and locate snipers both before and after shot over a large field-of-view. The high frame rate SWIR-camera allows resolution of the temporal profile of muzzle flashes which is the infrared signature associated with the ejection of the bullet from the rifle. The capability to detect and discriminate sniper muzzle flashes with this system has been verified by FOI in earlier studies. In this work we have extended the system by adding a laser channel for optics detection. A laser diode with slit-shaped beam profile is scanned over the camera field-of-view to detect retro reflection from optical sights. The optics detection system has been tested at various distances up to 1.15 km showing the feasibility to detect rifle scopes in full daylight. The high speed camera gives the possibility to discriminate false alarms by analyzing the temporal data. The intensity variation, caused by atmospheric turbulence, enables discrimination of small sights from larger reflectors due to aperture averaging, although the targets only cover a single pixel. It is shown that optics detection can be integrated in combination with muzzle flash detection by adding a scanning rectangular laser slit. The overall optics detection capability by continuous surveillance of a relatively large field-of-view looks promising. This type of multifunctional system may become an important tool to detect snipers before and after shot.

The piecewise-linear dynamic attenuator reduces the impact of count rate loss with photon-counting detectors

NASA Astrophysics Data System (ADS)

Hsieh, Scott S.; Pelc, Norbert J.

2014-06-01

Photon counting x-ray detectors (PCXDs) offer several advantages compared to standard energy-integrating x-ray detectors, but also face significant challenges. One key challenge is the high count rates required in CT. At high count rates, PCXDs exhibit count rate loss and show reduced detective quantum efficiency in signal-rich (or high flux) measurements. In order to reduce count rate requirements, a dynamic beam-shaping filter can be used to redistribute flux incident on the patient. We study the piecewise-linear attenuator in conjunction with PCXDs without energy discrimination capabilities. We examined three detector models: the classic nonparalyzable and paralyzable detector models, and a ‘hybrid’ detector model which is a weighted average of the two which approximates an existing, real detector (Taguchi et al 2011 Med. Phys. 38 1089-102 ). We derive analytic expressions for the variance of the CT measurements for these detectors. These expressions are used with raw data estimated from DICOM image files of an abdomen and a thorax to estimate variance in reconstructed images for both the dynamic attenuator and a static beam-shaping (‘bowtie’) filter. By redistributing flux, the dynamic attenuator reduces dose by 40% without increasing peak variance for the ideal detector. For non-ideal PCXDs, the impact of count rate loss is also reduced. The nonparalyzable detector shows little impact from count rate loss, but with the paralyzable model, count rate loss leads to noise streaks that can be controlled with the dynamic attenuator. With the hybrid model, the characteristic count rates required before noise streaks dominate the reconstruction are reduced by a factor of 2 to 3. We conclude that the piecewise-linear attenuator can reduce the count rate requirements of the PCXD in addition to improving dose efficiency. The magnitude of this reduction depends on the detector, with paralyzable detectors showing much greater benefit than nonparalyzable detectors.

Chemical Sensing for Buried Landmines - Fundamental Processes Influencing Trace Chemical Detection

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

PHELAN, JAMES M.

2002-05-01

Mine detection dogs have a demonstrated capability to locate hidden objects by trace chemical detection. Because of this capability, demining activities frequently employ mine detection dogs to locate individual buried landmines or for area reduction. The conditions appropriate for use of mine detection dogs are only beginning to emerge through diligent research that combines dog selection/training, the environmental conditions that impact landmine signature chemical vapors, and vapor sensing performance capability and reliability. This report seeks to address the fundamental soil-chemical interactions, driven by local weather history, that influence the availability of chemical for trace chemical detection. The processes evaluated include:more » landmine chemical emissions to the soil, chemical distribution in soils, chemical degradation in soils, and weather and chemical transport in soils. Simulation modeling is presented as a method to evaluate the complex interdependencies among these various processes and to establish conditions appropriate for trace chemical detection. Results from chemical analyses on soil samples obtained adjacent to landmines are presented and demonstrate the ultra-trace nature of these residues. Lastly, initial measurements of the vapor sensing performance of mine detection dogs demonstrates the extreme sensitivity of dogs in sensing landmine signature chemicals; however, reliability at these ultra-trace vapor concentrations still needs to be determined. Through this compilation, additional work is suggested that will fill in data gaps to improve the utility of trace chemical detection.« less

Analysis of a Novel Diffractive Scanning Wire Beam Position Monitor (BPM) for Discriminative Profiling of Electron Vs. X Ray Beams

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

Tatchyn, Roman; /SLAC

2011-09-01

Recent numerical studies of Free Electron Lasers (FELs) operating in the Self Amplified Spontaneous Emission (SASE) regime indicate a large sensitivity of the gain to the degree of transverse overlap (and associated phase coherence) between the electron and photon beams traveling down the insertion device. Simulations of actual systems imply that accurate detection and correction for this relative loss of overlap, rather than correction for the absolute departure of the electron beam from a fixed axis, is the preferred function of an FEL amplifier's Beam Position Monitor (BPM) and corrector systems. In this note we propose a novel diffractive BPMmore » with the capability of simultaneously detecting and resolving the absolute (and relative) transverse positions and profiles of electron and x-ray beams co-propagating through an undulator. We derive the equations governing the performance of the BPM and examine its predicted performance for the SLAC Linac Coherent Light Source (LCLS), viz., for profiling multi-GeV electron bunches co-propagating with one-to-several-hundred keV x-ray beams. Selected research and development (r&d) tasks for fabricating and testing the proposed BPM are discussed.« less

On-orbit Passive Thermography

NASA Technical Reports Server (NTRS)

Howell, Patricia A.; Winfree, William P.; Cramer, K. Elliott

2008-01-01

On July 12, 2006, British-born astronaut Piers Sellers became the first person to conduct thermal nondestructive evaluation experiments in space, demonstrating the feasibility of a new tool for detecting damage to the reinforced carbon-carbon (RCC) structures of the Shuttle. This new tool was an EVA (Extravehicular Activity, or spacewalk) compatible infrared camera developed by NASA engineers. Data was collected both on the wing leading edge of the Orbiter and on pre-damaged samples mounted in the Shuttle s cargo bay. A total of 10 infrared movies were collected during the EVA totaling over 250 megabytes of data. Images were downloaded from the orbiting Shuttle to Johnson Space Center for analysis and processing. Results are shown to be comparable to ground-based thermal inspections performed in the laboratory with the same type of camera and simulated solar heating. The EVA camera system detected flat-bottom holes as small as 2.54cm in diameter with 50% material loss from the back (hidden) surface in RCC during this first test of the EVA IR Camera. Data for the time history of the specimen temperature and the capability of the inspection system for imaging impact damage are presented.

Anomaly Detection for Beam Loss Maps in the Large Hadron Collider

NASA Astrophysics Data System (ADS)

Valentino, Gianluca; Bruce, Roderik; Redaelli, Stefano; Rossi, Roberto; Theodoropoulos, Panagiotis; Jaster-Merz, Sonja

2017-07-01

In the LHC, beam loss maps are used to validate collimator settings for cleaning and machine protection. This is done by monitoring the loss distribution in the ring during infrequent controlled loss map campaigns, as well as in standard operation. Due to the complexity of the system, consisting of more than 50 collimators per beam, it is difficult to identify small changes in the collimation hierarchy, which may be due to setting errors or beam orbit drifts with such methods. A technique based on Principal Component Analysis and Local Outlier Factor is presented to detect anomalies in the loss maps and therefore provide an automatic check of the collimation hierarchy.

International-Aerial Measuring System (I-AMS) Training Program

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

Wasiolek, Piotre T.; Malchor, Russell L.; Maurer, Richard J.

2015-10-01

Since the Fukushima reactor accident in 2011, there has been an increased interest worldwide in developing national capabilities to rapidly map and assess ground contamination resulting from nuclear reactor accidents. The capability to rapidly measure the size of the contaminated area, determine the activity level, and identify the radionuclides can aid emergency managers and decision makers in providing timely protective action recommendations to the public and first responders. The development of an aerial detection capability requires interagency coordination to assemble the radiation experts, detection system operators, and aviation aircrews to conduct the aerial measurements, analyze and interpret the data, andmore » provide technical assessments. The Office of International Emergency Management and Cooperation (IEMC) at the U.S. Department of Energy, National Nuclear Security Administration (DOE/NNSA) sponsors an International - Aerial Measuring System (I-AMS) training program for partner nations to develop and enhance their response to radiological emergencies. An initial series of courses can be conducted in the host country to assist in developing an aerial detection capability. As the capability develops and expands, additional experience can be gained through advanced courses with the opportunity to conduct aerial missions over a broad range of radiation environments.« less

X ray sensitive area detection device

NASA Technical Reports Server (NTRS)

Carter, Daniel C. (Inventor); Witherow, William K. (Inventor); Pusey, Marc L. (Inventor); Yost, Vaughn H. (Inventor)

1990-01-01

A radiation sensitive area detection device is disclosed which comprises a phosphor-containing film capable of receiving and storing an image formed by a pattern of incoming x rays, UV, or other radiation falling on the film. The device is capable of fluorescing in response to stimulation by a light source in a manner directly proportional to the stored radiation pattern. The device includes: (1) a light source capable of projecting light or other appropriate electromagnetic wave on the film so as to cause it to fluoresce; (2) a means to focus the fluoresced light coming from the phosphor-containing film after light stimulation; and (3) at least one charged coupled detector or other detecting element capable of receiving and digitizing the pattern of fluoresced light coming from the phosphor-containing film. The device will be able to generate superior x ray images of high resolution from a crystal or other sample and will be particularly advantageous in that instantaneous near-real-time images of rapidly deteriorating samples can be obtained. Furthermore, the device can be made compact and sturdy, thus capable of carrying out x ray or other radiation imaging under a variety of conditions, including those experienced in space.

International decade for natural disaster reduction

USGS Publications Warehouse

Hays, W. W.

1990-01-01

Throughout history, humanity has found itself in conflict with naturally occurring events of geologic, hydrologic, and atmospheric origin. this conflict has been demonstrated repeatedly when people build urban centers at the water's edge, in or near active fault systems capable of generating earthquakes, on steep slopes, near active volcanoes, or at the urban-wilderness interface prone to wildfires. Naturally occurring, recurrent events such as floods, windstorms, tsunamis, earthquakes, landslides, volcanic eruptions, and wildfires have tested human-engineered works many times and have often found them unable to withstand the forces generated by the event. In the past 20 years, for example, events like these throughout the world have claimed more than 2.8 million lives and adversely affected 820 million people; single disasters have caused economic losses of billions of dollars. Industrialized countries like the United States and Japan have been able to absorb the socioeconomic losses of past natural disasters, but the economics of many developing countries have been devastated by losses equal to a large percentage of their gross national product. Furthermore, the magnitude of the losses is increasing at a rapid rate as the building wealth of nations is expanded to meet the needs of rapidly increasing population, often without adequate consideration of the potential threat posed by the recurrent natural hazards and without implementing effective loss-reduction measures because of lack of knowledge or lack of technical capability. 

A robust algorithm for automated target recognition using precomputed radar cross sections

NASA Astrophysics Data System (ADS)

Ehrman, Lisa M.; Lanterman, Aaron D.

2004-09-01

Passive radar is an emerging technology that offers a number of unique benefits, including covert operation. Many such systems are already capable of detecting and tracking aircraft. The goal of this work is to develop a robust algorithm for adding automated target recognition (ATR) capabilities to existing passive radar systems. In previous papers, we proposed conducting ATR by comparing the precomputed RCS of known targets to that of detected targets. To make the precomputed RCS as accurate as possible, a coordinated flight model is used to estimate aircraft orientation. Once the aircraft's position and orientation are known, it is possible to determine the incident and observed angles on the aircraft, relative to the transmitter and receiver. This makes it possible to extract the appropriate radar cross section (RCS) from our simulated database. This RCS is then scaled to account for propagation losses and the receiver's antenna gain. A Rician likelihood model compares these expected signals from different targets to the received target profile. We have previously employed Monte Carlo runs to gauge the probability of error in the ATR algorithm; however, generation of a statistically significant set of Monte Carlo runs is computationally intensive. As an alternative to Monte Carlo runs, we derive the relative entropy (also known as Kullback-Liebler distance) between two Rician distributions. Since the probability of Type II error in our hypothesis testing problem can be expressed as a function of the relative entropy via Stein's Lemma, this provides us with a computationally efficient method for determining an upper bound on our algorithm's performance. It also provides great insight into the types of classification errors we can expect from our algorithm. This paper compares the numerically approximated probability of Type II error with the results obtained from a set of Monte Carlo runs.

Sniper detection using infrared camera: technical possibilities and limitations

NASA Astrophysics Data System (ADS)

Kastek, M.; Dulski, R.; Trzaskawka, P.; Bieszczad, G.

2010-04-01

The paper discusses technical possibilities to build an effective system for sniper detection using infrared cameras. Descriptions of phenomena which make it possible to detect sniper activities in infrared spectra as well as analysis of physical limitations were performed. Cooled and uncooled detectors were considered. Three phases of sniper activities were taken into consideration: before, during and after the shot. On the basis of experimental data the parameters defining the target were determined which are essential in assessing the capability of infrared camera to detect sniper activity. A sniper body and muzzle flash were analyzed as targets. The simulation of detection ranges was done for the assumed scenario of sniper detection task. The infrared sniper detection system was discussed, capable of fulfilling the requirements. The discussion of the results of analysis and simulations was finally presented.

Detection Rates of Cortical Auditory Evoked Potentials at Different Sensation Levels in Infants with Sensory/Neural Hearing Loss and Auditory Neuropathy Spectrum Disorder

PubMed Central

Gardner-Berry, Kirsty; Chang, Hsiuwen; Ching, Teresa Y. C.; Hou, Sanna

2016-01-01

With the introduction of newborn hearing screening, infants are being diagnosed with hearing loss during the first few months of life. For infants with a sensory/neural hearing loss (SNHL), the audiogram can be estimated objectively using auditory brainstem response (ABR) testing and hearing aids prescribed accordingly. However, for infants with auditory neuropathy spectrum disorder (ANSD) due to the abnormal/absent ABR waveforms, alternative measures of auditory function are needed to assess the need for amplification and evaluate whether aided benefit has been achieved. Cortical auditory evoked potentials (CAEPs) are used to assess aided benefit in infants with hearing loss; however, there is insufficient information regarding the relationship between stimulus audibility and CAEP detection rates. It is also not clear whether CAEP detection rates differ between infants with SNHL and infants with ANSD. This study involved retrospective collection of CAEP, hearing threshold, and hearing aid gain data to investigate the relationship between stimulus audibility and CAEP detection rates. The results demonstrate that increases in stimulus audibility result in an increase in detection rate. For the same range of sensation levels, there was no difference in the detection rates between infants with SNHL and ANSD. PMID:27587922

Early pregnancy factor (EPF) as a marker for the diagnosis of subclinical embryonic loss.

PubMed

Shahani, S K; Moniz, C; Chitlange, S; Meherji, P

1992-01-01

The validation of EPF as a possible correlate of early fertilization has made it possible to study and detect fertilization of the ovum in normal fertile women (during the luteal phase) and also in women with infertility, where the fertilization of the ovum may not be affected but there may be impairment in early embryonic development which results in early embryo loss or subclinical embryo loss. Our results have suggested that using EPF as a marker, we could detect subclinical embryonic loss in 57.8% of the infertile women where more than one menstrual cycle was studied and the blood was collected 4-7 days after ovulation. After the missed period, 80% of the patients who were negative for EPF but positive for hCG had spontaneous abortions. It would be interesting to study how EPF behaves as a marker, to detect subclinical embryonic loss in diverse pathological situations such as recurrent abortions, parental age and translocation carrier parents.

Pitfalls in the molecular genetic diagnosis of Leber hereditary optic neuropathy (LHON)

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

Johns, D.R.; Neufeld, M.J.

1993-10-01

Pathogenetic mutations in mtDNA are found in the majority of patients with Leber hereditary optic neuropathy (LHON), and molecular genetic techniques to detect them are important for diagnosis. A false-positive molecular genetic error has adverse consequences for the diagnosis of this maternally inherited disease. The authors found a number of mtDNA polymorphisms that occur adjacent to known LHON-associated mutations and that confound their molecular genetic detection. These transition mutations occur at mtDNA nt 11779 (SfaNI site loss, 11778 mutation), nt 3459 (BsaHI site loss, 3460 mutation), nt 15258 (AccI site loss, 15257 mutation), nt 14485 (mismatch primer Sau3AI site loss,more » 14484 mutation), and nt 13707 (BstNI site loss, 13708 mutation). Molecular genetic detection of the most common pathogenetic mtDNA mutations in LHON, using a single restriction enzyme, may be confounded by adjacent polymorphisms that occur with a false-positive rate of 2%-7%. 19 refs.« less

An explosives detection system for airline security using coherent x-ray scattering technology

NASA Astrophysics Data System (ADS)

Madden, Robert W.; Mahdavieh, Jacob; Smith, Richard C.; Subramanian, Ravi

2008-08-01

L-3 Communications Security and Detection Systems (SDS) has developed a new system for automated alarm resolution in airline baggage Explosive Detection Systems (EDS) based on coherent x-ray scattering spectroscopy. The capabilities of the system were demonstrated in tests with concealed explosives at the Transportation Security Laboratory and airline passenger baggage at Orlando International Airport. The system uses x-ray image information to identify suspicious objects and performs targeted diffraction measurements to classify them. This extra layer of detection capability affords a significant reduction in the rate of false alarm objects that must presently be resolved by opening passenger bags for hand inspection.

Performance analysis of a multispectral framing camera for detecting mines in the littoral zone and beach zone

NASA Astrophysics Data System (ADS)

Louchard, Eric; Farm, Brian; Acker, Andrew

2008-04-01

BAE Systems Sensor Systems Identification & Surveillance (IS) has developed, under contract with the Office of Naval Research, a multispectral airborne sensor system and processing algorithms capable of detecting mine-like objects in the surf zone and land mines in the beach zone. BAE Systems has used this system in a blind test at a test range established by the Naval Surface Warfare Center - Panama City Division (NSWC-PCD) at Eglin Air Force Base. The airborne and ground subsystems used in this test are described, with graphical illustrations of the detection algorithms. We report on the performance of the system configured to operate with a human operator analyzing data on a ground station. A subsurface (underwater bottom proud mine in the surf zone and moored mine in shallow water) mine detection capability is demonstrated in the surf zone. Surface float detection and proud land mine detection capability is also demonstrated. Our analysis shows that this BAE Systems-developed multispectral airborne sensor provides a robust technical foundation for a viable system for mine counter-measures, and would be a valuable asset for use prior to an amphibious assault.

What can be learned from a future supernova neutrino detection?

NASA Astrophysics Data System (ADS)

Horiuchi, Shunsaku; Kneller, James P.

2018-04-01

This year marks the 30th anniversary of the only supernova from which we have detected neutrinos—SN 1987A. The 20 or so neutrinos that were detected were mined to great depth in order to determine the events that occurred in the explosion and to place limits upon all manner of neutrino properties. Since 1987 the scale and sensitivity of the detectors capable of identifying neutrinos from a Galactic supernova have grown considerably so that current generation detectors are capable of detecting of order 10 000 neutrinos for a supernova at the Galactic Center. Next generation detectors will increase that yield by another order of magnitude. Simultaneous with the growth of neutrino detection capability, our understanding of how massive stars explode and how the neutrino interacts with hot and dense matter has also increased by a tremendous degree. The neutrino signal will contain much information on all manner of physics of interest to a wide community. In this review we describe the expected features of the neutrino signal, the detectors which will detect it, and the signatures one might try to look for in order to get at this physics.

Detection and classification of underwater targets by echolocating dolphins

NASA Astrophysics Data System (ADS)

Au, Whitlow

2003-10-01

Many experiments have been performed with echolocating dolphins to determine their target detection and discrimination capabilities. Target detection experiments have been performed in a naturally noisy environment, with masking noise and with both phantom echoes and masking noise, and in reverberation. The echo energy to rms noise spectral density for the Atlantic bottlenose dolphin (Tursiops truncatus) at the 75% correct response threshold is approximately 7.5 dB whereas for the beluga whale (Delphinapterus leucas) the threshold is approximately 1 dB. The dolphin's detection threshold in reverberation is approximately 2.5 dB vs 2 dB for the beluga. The difference in performance between species can probably be ascribed to differences in how both species perceived the task. The bottlenose dolphin may be performing a combination detection/discrimination task whereas the beluga may be performing a simple detection task. Echolocating dolphins also have the capability to make fine discriminate of target properties such as wall thickness difference of water-filled cylinders and material differences in metallic plates. The high resolution property of the animal's echolocation signals and the high dynamic range of its auditory system are important factors in their outstanding discrimination capabilities.

Earth's surface loading study using InSAR

NASA Astrophysics Data System (ADS)

Amelung, F.; Zhao, W.; Doin, M. P.

2014-12-01

Earth's surface loading/unloading such as glacier retreat, lake water level change, ocean tide, cause measurable (centimeter to millimeter) surface deformation from Synthetic Aperture Radar Interferometry (InSAR). Such seasonal or decadal deformation signals are useful for the estimation of the amount of load and the parameterization of crust and upper mantle - typically under an elastic or a visco-elastic mechanism. Since 2010, we established a study of surface loading using small baseline InSAR time-series analysis. Four sites are included in this study, which are Vatnajokull ice cap, Lake Yamzho Yumco, Petermann glacier, and Barnes ice cap using different satellites such as ERS1/2, Envisat, Radarsat-2, TerraSAR-X. We present results that mainly answer three questions: 1) Is InSAR time-series capable for the detection of millimeter level deformation due to surface loading; 2) When the Earth's rheology is known, how much load change occured; 3) When the surface loading is known, what are the Earth's parameters such as Young's modulus, viscosity. For glacier retreat problem, we introduce a new model for the ice mass loss estimation considering the spatial distribution of ice loss. For lake unloading problem, modeled elastic parameters are useful for the comparison to other 1-D models, e.g. the model based on seismic data.

Molecular evidence of heavy-oil weathering following the M/V Cosco Busan spill: insights from Fourier transform ion cyclotron resonance mass spectrometry.

PubMed

Lemkau, Karin L; McKenna, Amy M; Podgorski, David C; Rodgers, Ryan P; Reddy, Christopher M

2014-04-01

Recent studies have highlighted a critical need to investigate oil weathering beyond the analytical window afforded by conventional gas chromatography (GC). In particular, techniques capable of detecting polar and higher molecular weight (HMW; > 400 Da) components abundant in crude and heavy fuel oils (HFOs) as well as transformation products. Here, we used atmospheric pressure photoionization Fourier transform ion cyclotron resonance mass spectrometry (APPI FT-ICR MS) to identify molecular transformations in oil-residue samples from the 2007 M/V Cosco Busan HFO spill (San Francisco, CA). Over 617 days, the abundance and diversity of oxygen-containing compounds increased relative to the parent HFO, likely from bio- and photodegradation. HMW, highly aromatic, alkylated compounds decreased in relative abundance concurrent with increased relative abundance of less alkylated stable aromatic structures. Combining these results with GC-based data yielded a more comprehensive understanding of oil spill weathering. For example, dealkylation trends and the overall loss of HMW species observed by FT-ICR MS has not previously been documented and is counterintuitive given losses of lower molecular weight species observed by GC. These results suggest a region of relative stability at the interface of these techniques, which provides new indicators for studying long-term weathering and identifying sources.

The optimised sc dipole of SIS100 for series production

NASA Astrophysics Data System (ADS)

Roux, Christian; Mierau, Anna; Bleile, Alexander; Fischer, Egbert; Kaether, Florian; Körber, Boris; Schnizer, Pierre; Sugita, Kei; Szwangruber, Piotr

2017-02-01

At the international facility for antiproton and ion research (FAIR) in Darmstadt, Germany, an accelerator complex is developed for fundamental research in various fields of modern physics. In the SIS100 heavy-ion synchrotron, the main accelerator of FAIR, superconducting dipoles are used to bend the particle beam. The fast ramped dipoles are 3 m long super-ferric curved magnets operated at 4.5 K. The demands on field homogeneity required for sufficient beam stability are given by ΔB/B ≤ ±6 · 10-4. An intense measurement program of the First of Series (FoS) dipole showed excellent quench behavior and lower than expected AC losses yielding the main load on the SIS100 cryoplant. The FoS is capable to provide a field strength of 1.9 T. However, with sophisticated measurement systems slight distortions of the dipole field were detected. Those effects were tracked down to mechanical inaccuracies of the yoke proven by appropriate geometrical measurements and simulations. After a survey on alternative fabrication techniques a magnet with a new yoke was built with substantial changes to improve the mechanical accuracy. Its characteristics concerning cryogenic losses, cold geometry and the resulting magnetic-field quality are presented and an outlook on the series production of superconducting dipoles for SIS100 is given.

Use of open-path FTIR and inverse dispersion technique to quantify gaseous nitrogen loss from an intensive vegetable production site

NASA Astrophysics Data System (ADS)

Bai, Mei; Suter, Helen; Lam, Shu Kee; Sun, Jianlei; Chen, Deli

2014-09-01

An open-path Fourier transform infrared (OP-FTIR) spectroscopic technique in combination with a backward Lagrangian stochastic (bLS) dispersion model (WindTrax) can be used to simultaneously measure gaseous emissions of N2O, NH3, CH4 and CO2. We assessed the capability of this technique for measuring NH3 and N2O emissions following the application of calcium nitrate (Ca(NO3)2), Nitrophoska (NPK) and chicken manure on a celery farm at Boneo, Victoria, during April and May 2013. We found that the OP-FTIR/WindTrax method was able to measure the diurnal variation in NH3 flux from the field site following application of chicken manure with measured emissions ranging from approximately 0.1-9.8 kg NH3-N ha-1 day-1. The OP-FTIR/WindTrax method also detected a diurnal variation in N2O flux of 1.5-6.2 kg N2O-N ha-1 day-1 and N2O flux increased in response to application of the Ca(NO3)2. We concluded that the OP-FTIR/WindTrax technique can quantify gaseous N loss from vegetable production systems.

Sustainability of industrial yeast serial repitching practice studied by gene expression and correlation analysis.

PubMed

Bühligen, Franziska; Rüdinger, Philipp; Fetzer, Ingo; Stahl, Frank; Scheper, Thomas; Harms, Hauke; Müller, Susann

2013-12-01

Bottom-fermenting Saccharomyces pastorianus strains driving brewing fermentation processes are usually reused several times. It is still unclear, whether the number of successions may have an impact on cell physiology prompting consequences for brewing quality. In this study, fermentation performance of up to twenty consecutive runs in a brewery was investigated. For each run mRNA expression levels of cellular marker molecules, which are known to correlate with metabolism, hexose transport, aging processes, stress response mechanisms and flocculation capability was estimated to obtain information on changes in cell physiology over the successive runs. Low-density microarrays were used for this purpose and the resulting gene expression profiles were finally correlated with changes in the abiotic micro-environments. A surprising stability of the marker molecule expression profiles within each specific serial repitching was stated. Loss of flocculation or an advanced aging could not be detected during serial repitching in the analyzed brewery. However, certain runs of the serial repitchings showed high variation in stress response which was found to be caused by perturbations of the abiotic conditions. Regardless, the study showed that S. pastorianus can be used repeatedly in serial repitching processes without loss of prominent physiological characteristics. Copyright © 2013 Elsevier B.V. All rights reserved.

Shallow water imaging sonar system for environmental surveying. Final report

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

NONE

1998-05-01

The scope of this research is to develop a shallow water sonar system designed to detect and map the location of objects such as hazardous wastes or discarded ordnance in coastal waters. The system will use high frequency wide-bandwidth imaging sonar, mounted on a moving platform towed behind a boat, to detect and identify objects on the sea bottom. Resolved images can be obtained even if the targets are buried in an overlayer of silt. The specific technical objective of this research was to develop and test a prototype system that is capable of (1) scan at high speeds (upmore » to 10m/s), even in shallow water (depth to ten meters), without motion blurring or loss of resolution; (2) produce images of the bottom structure that are detailed enough for unambiguous detection of objects as small as 15cm, even if they are buried up to 30cm deep in silt or sand. The critical technology involved uses an linear FM (LFM) or similar complex waveform, which has a high bandwidth for good range resolution, with a long pulse length for similar Dopper resolution. The lone duration signal deposits more energy on target than a narrower pulse, which increases the signal-to-noise ratio and signal-to-clutter ratio. This in turn allows the use of cheap, lightweight, low power, piezoelectric transducers at the 30--500 kHz range.« less

Evaluation and refinement of a field-portable drinking water toxicity sensor utilizing electric cell-substrate impedance sensing and a fluidic biochip.

PubMed

Widder, Mark W; Brennan, Linda M; Hanft, Elizabeth A; Schrock, Mary E; James, Ryan R; van der Schalie, William H

2015-07-01

The US Army's need for a reliable and field-portable drinking water toxicity sensor was the catalyst for the development and evaluation of an electric cell-substrate impedance sensing (ECIS) device. Water testing technologies currently available to soldiers in the field are analyte-specific and have limited capabilities to detect broad-based water toxicity. The ECIS sensor described here uses rainbow trout gill epithelial cells seeded on fluidic biochips to measure changes in impedance for the detection of possible chemical contamination of drinking water supplies. Chemicals selected for testing were chosen as representatives of a broad spectrum of toxic industrial compounds. Results of a US Environmental Protection Agency (USEPA)-sponsored evaluation of the field portable device were similar to previously published US Army testing results of a laboratory-based version of the same technology. Twelve of the 18 chemicals tested following USEPA Technology Testing and Evaluation Program procedures were detected by the ECIS sensor within 1 h at USEPA-derived human lethal concentrations. To simplify field-testing methods further, elimination of a procedural step that acclimated cells to serum-free media streamlined the test process with only a slight loss of chemical sensitivity. For field use, the ECIS sensor will be used in conjunction with an enzyme-based sensor that is responsive to carbamate and organophosphorus pesticides. Copyright © 2014 John Wiley & Sons, Ltd.

Development and validation of an anti-N3 indirect immunofluorescent antibody test to be used as a companion diagnostic test in the framework of a "DIVA" vaccination strategy for avian influenza infections in poultry.

PubMed

Cattoli, Giovanni; Milani, Adelaide; Bettini, Francesca; Serena Beato, Maria; Mancin, Marzia; Terregino, Calogero; Capua, Ilaria

2006-04-01

Avian influenza (AI) infections have become of growing importance both for animal and human health. Vaccination has become a recommended tool to support eradication efforts and limit the economic losses caused by this disease. The "DIVA" system, using a vaccine containing a heterologous neuraminidase to the field virus, has been shown to be an effective tool in increasing the resistance of birds to field challenge, preventing clinical signs and reducing viral shedding in the environment. The companion diagnostic test to the vaccine, however, has been only partially validated in the field against one subtype of neuraminidase (N1). The present paper presents the results of a full laboratory and field validation of the diagnostic test developed to detect antibodies to the N3 subtype of AI in vaccinated and unvaccinated chickens and turkeys. Antibody kinetic studies conducted in the laboratory have shown that antibodies to the N protein may be detected earlier than antibodies to the haemagglutinin. The data derived from this extensive validation trial indicate the excellent capability of this assay in detecting the presence of active AI infection at an early stage in both unvaccinated and vaccinated birds and the lack of interference with vaccine-induced antibodies.

Failure detection and recovery in the assembly/contingency subsystem

NASA Technical Reports Server (NTRS)

Gantenbein, Rex E.

1993-01-01

The Assembly/Contingency Subsystem (ACS) is the primary communications link on board the Space Station. Any failure in a component of this system or in the external devices through which it communicates with ground-based systems will isolate the Station. The ACS software design includes a failure management capability (ACFM) that provides protocols for failure detection, isolation, and recovery (FDIR). The the ACFM design requirements as outlined in the current ACS software requirements specification document are reviewed. The activities carried out in this review include: (1) an informal, but thorough, end-to-end failure mode and effects analysis of the proposed software architecture for the ACFM; and (2) a prototype of the ACFM software, implemented as a C program under the UNIX operating system. The purpose of this review is to evaluate the FDIR protocols specified in the ACS design and the specifications themselves in light of their use in implementing the ACFM. The basis of failure detection in the ACFM is the loss of signal between the ground and the Station, which (under the appropriate circumstances) will initiate recovery to restore communications. This recovery involves the reconfiguration of the ACS to either a backup set of components or to a degraded communications mode. The initiation of recovery depends largely on the criticality of the failure mode, which is defined by tables in the ACFM and can be modified to provide a measure of flexibility in recovery procedures.

Early Wheel Train Damage Detection Using Wireless Sensor Network Antenna

NASA Astrophysics Data System (ADS)

Fazilah, A. F. M.; Azemi, S. N.; Azremi, A. A. H.; Soh, P. J.; Kamarudin, L. M.

2018-03-01

Antenna for a wireless sensor network for early wheel trains damage detection has successfully developed and fabricated with the aim to minimize the risk and increase the safety guaranty for train. Current antenna design is suffered in gain and big in size. For the sensor, current existing sensor only detect when the wheel malfunction. Thus, a compact microstrip patch antenna with operating frequency at 2.45GHz is design with high gain of 4.95dB will attach to the wireless sensor device. Simulation result shows that the antenna is working at frequency 2.45GHz and the return loss at -34.46dB are in a good agreement. The result also shows the good radiation pattern and almost ideal VSWR which is 1.04. The Arduino Nano, LM35DZ and ESP8266-07 Wi-Fi module is applied to the core system with capability to sense the temperature and send the data wirelessly to the cloud. An android application has been created to monitor the temperature reading based on the real time basis. The mainly focuses for the future improvement is by minimize the size of the antenna in order to make in more compact. In addition, upgrade an android application that can collect the raw data from cloud and make an alarm system to alert the loco pilot.

Recent advances of mid-infrared compact, field deployable sensors: principles and applications

NASA Astrophysics Data System (ADS)

Tittel, Frank; Gluszek, Aleksander; Hudzikowski, Arkadiusz; Dong, Lei; Li, Chunguang; Patimisco, Pietro; Sampaolo, Angelo; Spagnolo, Vincenzo; Wojtas, Jacek

2016-04-01

The recent development of compact interband cascade lasers(ICLs) and quantum cascade lasers (QCLs) based trace gas sensors will permit the targeting of strong fundamental rotational-vibrational transitions in the mid-infrared which are one to two orders of magnitude more intense than transitions in the overtone and combination bands in the near-infrared. This has led to the design and fabrication of mid-infrared compact, field deployable sensors for use in the petrochemical industry, environmental monitoring and atmospheric chemistry. Specifically, the spectroscopic detection and monitoring of four molecular species, methane (CH4) [1], ethane (C2H6), formaldehyde (H2CO) [2] and hydrogen sulphide (H2S) [3] will be described. CH4, C2H6 and H2CO can be detected using two detection techniques: mid-infrared tunable laser absorption spectroscopy (TDLAS) using a compact multi-pass gas cell and quartz enhanced photoacoustic spectroscopy (QEPAS). Both techniques utilize state-of-the-art mid-IR, continuous wave (CW), distributed feedback (DFB) ICLs and QCLs. TDLAS was performed with an ultra-compact 54.6m effective optical path length innovative spherical multipass gas cell capable of 435 passes between two concave mirrors separated by 12.5 cm. QEPAS used a small robust absorption detection module (ADM) which consists of a quartz tuning fork (QTF), two optical windows, gas inlet/outlet ports and a low noise frequency pre-amplifier. Wavelength modulation and second harmonic detection were employed for spectral data processing. TDLAS and QEPAS can achieve minimum detectable absorption losses in the range from 10-8 to 10-11cm-1/Hz1/2. Several recent examples of real world applications of field deployable gas sensors will be described. For example, an ICL based TDLAS sensor system is capable of detecting CH4 and C2H6 concentration levels of 1 ppb in a 1 sec. sampling time, using an ultra-compact, robust sensor architecture. H2S detection was realized with a THz QEPAS sensor system using a custom quartz tuning fork (QTF) with a new geometry and a QCL emitting at 2.913 THz [4]. Furthermore, two new approaches aimed to achieve enhanced detection sensitivities with QEPAS based sensing can be realized. The first method will make use of a compact optical power buildup cavity, which achieves significantly lower minimum detectable trace gas concentration levels of < 10 pptv. The second approach will use custom fabricated QTFs capable of improved detection sensitivity. Acknowledgements F.K. Tittel acknowledges support by the National Science Foundation (NSF) ERC MIRTHE award, the Robert Welch Foundation (Grant C-0586) and DOE ARPA-E Monitor Proram. L. Dong acknowledges support by NSF-China (Grant #s. 61275213, 61108030), J. Wojtas acknowledges support by The National Centre for Research and Development, Poland (project ID: 179616). References [1] L. Dong, C. Li, N. P. Sanchez, A. K. Gluszek, R. Griffin and F. K. Tittel;" Compact CH4 sensor system based on a continuous-wave, low power consumption, room temperature interband cascade laser", Appl. Phys Lett. 108, 011106 (2016). [2] L. Dong, Y. Yu, C. Li, S. So, and F.K. Tittel, "Ppb-level formaldehyde detection using a CW room-temperature interband cascade laser and a miniature dense pattern multipass cell" Optics Express; 23, 19821-19830 (2015). [3] V. Spagnolo, P. Patimisco, R. Pennetta, A. Sampaolo, G. Scamarcio, M. Vitiello, and F.K. Tittel, "THz Quartz-enhanced photoacoustic sensor for H2S trace gas detection", Opt. Exp. 23, 7574-7582 (2015). [4] A. Sampaolo, P. Patimisco, L. Dong , A. Geras, S, G. Scamarcio' T. Starecki, F.K Tittel, V. Spagnolo; "Quartz-Enhanced Photoacoustic Spectroscopy exploiting tuning fork overtone modes", Appl. Phys Lett. 107, 231102 (2015).

Decision - making of Direct Customers Based on Available Transfer Capability

NASA Astrophysics Data System (ADS)

Quan, Tang; Zhaohang, Lin; Huaqiang, Li

2017-05-01

Large customer direct-power-purchasing is a hot spot in the electricity market reform. In this paper, the author established an Available Transfer Capability (ATC) model which takes uncertain factors into account, applied the model into large customer direct-power-purchasing transactions and improved the reliability of power supply during direct-power-purchasing by introducing insurance theory. The author also considered the customers loss suffered from power interruption when building ATC model, established large customer decision model, took purchasing quantity of power from different power plants and reserved capacity insurance as variables, targeted minimum power interruption loss as optimization goal and best solution by means of particle swarm algorithm to produce optimal power purchasing decision of large consumers. Simulation was made through IEEE57 system finally and proved that such method is effective.

A hybrid nanosensor for TNT vapor detection.

PubMed

Díaz Aguilar, Alvaro; Forzani, Erica S; Leright, Mathew; Tsow, Francis; Cagan, Avi; Iglesias, Rodrigo A; Nagahara, Larry A; Amlani, Islamshah; Tsui, Raymond; Tao, N J

2010-02-10

Real-time detection of trace chemicals, such as explosives, in a complex environment containing various interferents has been a difficult challenge. We describe here a hybrid nanosensor based on the electrochemical reduction of TNT and the interaction of the reduction products with conducting polymer nanojunctions in an ionic liquid. The sensor simultaneously measures the electrochemical current from the reduction of TNT and the conductance change of the polymer nanojunction caused from the reduction product. The hybrid detection mechanism, together with the unique selective preconcentration capability of the ionic liquid, provides a selective, fast, and sensitive detection of TNT. The sensor, in its current form, is capable of detecting parts-per-trillion level TNT in the presence of various interferents within a few minutes.

Organo Luminescent semiconductor nanocrystal probes for biological applications and process for making and using such probes

DOEpatents

Weiss, Shimon; Bruchez, Jr., Marcel; Alivisatos, Paul

1999-01-01

A luminescent semiconductor nanocrystal compound is described which is capable of linking to an affinity molecule. The compound comprises (1) a semiconductor nanocrystal capable of emitting electromagnetic radiation (luminescing) in a narrow wavelength band and/or absorbing energy, and/or scattering or diffracting electromagnetic radiation--when excited by an electromagnetic radiation source (of narrow or broad bandwidth) or a particle beam; and (2) at least one linking agent, having a first portion linked to the semiconductor nanocrystal and a second portion capable of linking to an affinity molecule. The luminescent semiconductor nanocrystal compound is linked to an affinity molecule to form an organo luminescent semiconductor nanocrystal probe capable of bonding with a detectable substance in a material being analyzed, and capable of emitting electromagnetic radiation in a narrow wavelength band and/or absorbing, scattering, or diffracting energy when excited by an electromagnetic radiation source (of narrow or broad bandwidth) or a particle beam. The probe is stable to repeated exposure to light in the presence of oxygen and/or other radicals. Further described is a process for making the luminescent semiconductor nanocrystal compound and for making the organo luminescent semiconductor nanocrystal probe comprising the luminescent semiconductor nanocrystal compound linked to an affinity molecule capable of bonding to a detectable substance. A process is also described for using the probe to determine the presence of a detectable substance in a material.

Paucity of PD-L1 expression in prostate cancer: innate and adaptive immune resistance.

PubMed

Martin, A M; Nirschl, T R; Nirschl, C J; Francica, B J; Kochel, C M; van Bokhoven, A; Meeker, A K; Lucia, M S; Anders, R A; DeMarzo, A M; Drake, C G

2015-12-01

Primary prostate cancers are infiltrated with programmed death-1 (PD-1) expressing CD8+ T-cells. However, in early clinical trials, men with metastatic castrate-resistant prostate cancer did not respond to PD-1 blockade as a monotherapy. One explanation for this unresponsiveness could be that prostate tumors generally do not express programmed death ligand-1 (PD-L1), the primary ligand for PD-1. However, lack of PD-L1 expression in prostate cancer would be surprising, given that phosphatase and tensin homolog (PTEN) loss is relatively common in prostate cancer and several studies have shown that PTEN loss correlates with PD-L1 upregulation--constituting a mechanism of innate immune resistance. This study tested whether prostate cancer cells were capable of expressing PD-L1, and whether the rare PD-L1 expression that occurs in human specimens correlates with PTEN loss. Human prostate cancer cell lines were evaluated for PD-L1 expression and loss of PTEN by flow cytometry and western blotting, respectively. Immunohistochemical (IHC) staining for PTEN was correlated with PD-L1 IHC using a series of resected human prostate cancer samples. In vitro, many prostate cancer cell lines upregulated PD-L1 expression in response to inflammatory cytokines, consistent with adaptive immune resistance. In these cell lines, no association between PTEN loss and PD-L1 expression was apparent. In primary prostate tumors, PD-L1 expression was rare, and was not associated with PTEN loss. These studies show that some prostate cancer cell lines are capable of expressing PD-L1. However, in human prostate cancer, PTEN loss is not associated with PD-L1 expression, arguing against innate immune resistance as a mechanism that mitigates antitumor immune responses in this disease.

Sixty-four-Channel Inline Cable Tester

NASA Technical Reports Server (NTRS)

2008-01-01

Faults in wiring are a serious concern for the aerospace and aeronautics (commercial, military, and civil) industries. A number of accidents have occurred because faulty wiring created shorts or opens that resulted in the loss of control of the aircraft or because arcing led to fires and explosions. Some of these accidents have resulted in the massive loss of lives (such as in the TWA Flight 800 accident). Circuits on the Space Shuttle have also failed because of faulty insulation on wiring. STS-93 lost power when a primary power circuit in one engine failed and a second engine had a backup power circuit fault. Cables are usually tested on the ground after the crew reports a fault encountered during flight. Often such failures result from vibration and cannot be replicated while the aircraft is stationary. It is therefore important to monitor faults while the aircraft is in operation, when cables are more likely to fail. Work is in progress to develop a cable fault tester capable of monitoring up to 64 individual wires simultaneously. Faults can be monitored either inline or offline. In the inline mode of operation, the monitoring is performed without disturbing the normal operation of the wires under test. That is, the operations are performed unintrusively and are essentially undetectable for the test signal levels are below the noise floor. A cable can be monitored several times per second in the offline mode and once a second in the inline mode. The 64-channel inline cable tester not only detects the occurrence of a fault, but also determines the type of fault (short/open) and the location of the fault. This will enable the detection of intermittent faults that can be repaired before they become serious problems.

Metal ions from S‐PRG filler have the potential to prevent periodontal disease

PubMed Central

Iwamatsu‐Kobayashi, Yoko; Abe, Syouta; Fujieda, Yoshiyasu; Orimoto, Ai; Kanehira, Masafumi; Handa, Keisuke; Venkataiah, Venkata Suresh; Zou, Wei; Ishikawa, Masaki

2017-01-01

Abstract The surface pre‐reacted glass ionomer (S‐PRG) filler, a component of composite resin, is capable of releasing metal ions that possess antibacterial activity against caries and periodontal pathogens. Although S‐PRG has been suggested to be involved in oral disease prevention, no reports have been published regarding its preventive effect on periodontal disease in vivo. The present study investigated whether the eluate from S‐PRG (S‐PRG eluate) has a suppressive effect on tissue destruction induced in a mouse model of ligature‐induced periodontal disease. Twenty‐seven C57BL/6 mice were divided into three groups of nine animals each, no ligature group (Lig(−)), ligature group (Lig(+)S‐PRG(−)) and ligature with S‐PRG eluate group (Lig(+)S‐PRG(+)). Alveolar bone loss was evaluated using micro‐computed tomography scanning. Histologic changes were detected by hematoxylin and eosin staining. The infiltration of inflammatory cells was assessed by Ly6G and F4/80 staining immunohistochemically. The distribution of metal ions was detected by time‐of‐flight secondary ion mass spectrometry. S‐PRG eluate clearly inhibited alveolar bone loss and bone density. The histological analysis revealed that S‐PRG eluate reduced destruction of the collagen bundle in the periodontal ligament and the infiltration of inflammatory cells. Immunohistochemical analysis showed that the S‐PRG eluate significantly suppressed the number of infiltrating neutrophils and macrophages. Time‐of‐flight secondary ion mass spectrometry analysis revealed that more boron ions were present in the Lig(+)S‐PRG(+) group than in the Lig(+)S‐PRG(−) group. Our results suggest that the S‐PRG eluate has a preventive effect against tissue destruction in periodontal disease through its anti‐inflammatory effects in vivo. PMID:29744190

Helicopter collision avoidance and brown-out recovery with HELLAS

NASA Astrophysics Data System (ADS)

Seidel, Christian; Schwartz, Ingo; Kielhorn, Peter

2008-10-01

EADS Germany is the world market leader in commercial and military Helicopter Laser Radar (HELLAS) Obstacle Warning Systems. The HELLAS-Warning System has been introduced into the market in 2000, is in service at German Federal Police and Royal Thai Air Force. HELLAS was also successfully evaluated by the Foreign Comparative Test Program (FCT) of the U.S. Army and other governmental agencies. Currently the successor system for military applications, HELLAS-Awareness, is in qualification phase. It will have extended sensor performance, enhanced real-time data processing capabilities and advanced human machine interface (HMI) features. Flight tests on NH90 helicopter have been successfully performed. Helicopter series integration is scheduled to begin from 2009. We will give an outline of the new sensor unit concerning detection technology and helicopter integration aspects. The system provides a widespread field of view with additional dynamic line of sight steering and a large detection range in combination with a high frame rate. We will show the HMI representations. This HELLAS system is the basis for a 3 dimensional see-and-remember-system for brown-out recovery. When landing in sandy or dusty areas the downwash of the helicopter rotor causes clouds of visually-restrictive material that can completely obstruct the pilot's outside reference, resulting in a complete loss of situational awareness and spatial orientation of the pilot which can end up in total loss of aircraft control and dangerous accidents. The brown-out recovery system presented here creates an augmented enhanced synthetic vision of the landing area with the surrounding which is based on HELLAS range image data as well as altimeter and inertial reference information.

Response of transposable elements to environmental stressors.

PubMed

Miousse, Isabelle R; Chalbot, Marie-Cecile G; Lumen, Annie; Ferguson, Alesia; Kavouras, Ilias G; Koturbash, Igor

2015-01-01

Transposable elements (TEs) comprise a group of repetitive sequences that bring positive, negative, as well as neutral effects to the host organism. Earlier considered as "junk DNA," TEs are now well-accepted driving forces of evolution and critical regulators of the expression of genetic information. Their activity is regulated by epigenetic mechanisms, including methylation of DNA and histone modifications. The loss of epigenetic control over TEs, exhibited as loss of DNA methylation and decondensation of the chromatin structure, may result in TEs reactivation, initiation of their insertional mutagenesis (retrotransposition) and has been reported in numerous human diseases, including cancer. Accumulating evidence suggests that these alterations are not the simple consequences of the disease, but often may drive the pathogenesis, as they can be detected early during disease development. Knowledge derived from the in vitro, in vivo, and epidemiological studies, clearly demonstrates that exposure to ubiquitous environmental stressors, many of which are carcinogens or suspected carcinogens, are capable of causing alterations in methylation and expression of TEs and initiate retrotransposition events. Evidence summarized in this review suggests that TEs are the sensitive endpoints for detection of effects caused by such environmental stressors, as ionizing radiation (terrestrial, space, and UV-radiation), air pollution (including particulate matter [PM]-derived and gaseous), persistent organic pollutants, and metals. Furthermore, the significance of these effects is characterized by their early appearance, persistence and presence in both, target organs and peripheral blood. Altogether, these findings suggest that TEs may potentially be introduced into safety and risk assessment and serve as biomarkers of exposure to environmental stressors. Furthermore, TEs also show significant potential to become invaluable surrogate biomarkers in clinic and possible targets for therapeutic modalities for disease treatment and prevention. Copyright © 2015 Elsevier B.V. All rights reserved.

Transposable elements in response to environmental stressors&

PubMed Central

Miousse, Isabelle R.; Chalbot, Marie-Cecile G.; Lumen, Annie; Ferguson, Alesia; Kavouras, Ilias G.; Koturbash, Igor

2015-01-01

Transposable elements (TEs) comprise a group of repetitive sequences that bring positive, negative, as well as neutral effects to the host organism. Earlier considered as “junk DNA,” TEs are now well-accepted driving forces of evolution and critical regulators the of expression of genetic information. Their activity is regulated by epigenetic mechanisms, including methylation of DNA and histone modifications. The loss of epigenetic control over TEs, exhibited as loss of DNA methylation and decondensation of the chromatin structure, may result in TEs reactivation, initiation of their insertional mutagenesis (retrotransposition) and has been reported in numerous human diseases, including cancer. Accumulating evidence suggests that these alterations are not the simple consequences of the disease, but often may drive the pathogenesis, as they can be detected early during disease development. Knowledge derived from the in vitro, in vivo, and epidemiological studies, clearly demonstrates that exposure to ubiquitous environmental stressors, many of which are carcinogens or suspected carcinogens, are capable of causing alterations in methylation and expression of TEs and initiate retrotransposition events. Evidence summarized in this review suggests that TEs are the sensitive endpoints for detection of effects caused by such environmental stressors, as ionizing radiation (terrestrial, space, and UV-radiation), air pollution (including particulate matter [PM]-derived and gaseous), persistent organic pollutants, and metals. Furthermore, the significance of these effects is characterized by their early appearance, persistence and presence in both, target organs and peripheral blood. Altogether, these findings suggest that TEs may potentially be introduced into safety and risk assessment and serve as biomarkers of exposure to environmental stressors. Furthermore, TEs also show significant potential to become invaluable surrogate biomarkers in clinic and possible targets for therapeutic modalities for disease treatment and prevention. PMID:26281766

Quantitative Percussion Diagnostics For Evaluating Bond Integrity Between Composite Laminates

NASA Astrophysics Data System (ADS)

Poveromo, Scott Leonard

Conventional nondestructive testing (NDT) techniques used to detect defects in composites are not able to determine intact bond integrity within a composite structure and are costly to use on large and complex shaped surfaces. To overcome current NDT limitations, a new technology was utilized based on quantitative percussion diagnostics (QPD) to better quantify bond quality in fiber reinforced composite materials. Experimental results indicate that this technology is capable of detecting 'kiss' bonds (very low adhesive shear strength), caused by the application of release agents on the bonding surfaces, between flat composite laminates bonded together with epoxy adhesive. Specifically, the local value of the loss coefficient determined from quantitative percussion testing was found to be significantly greater for a release coated panel compared to that for a well bonded sample. Also, the local value of the probe force or force returned to the probe after impact was observed to be lower for the release coated panels. The increase in loss coefficient and decrease in probe force are thought to be due to greater internal friction during the percussion event for poorly bonded specimens. NDT standards were also fabricated by varying the cure parameters of an epoxy film adhesive. Results from QPD for the variable cure NDT standards and lap shear strength measurements taken of mechanical test specimens were compared and analyzed. Finally, experimental results have been compared to a finite element analysis to understand the visco-elastic behavior of the laminates during percussion testing. This comparison shows how a lower quality bond leads to a reduction in the percussion force by biasing strain in the percussion tested side of the panel.

Strategies for the screening of antibiotic residues in eggs: comparison of the validation of the classical microbiological method with an immunobiosensor method.

PubMed

Gaudin, Valérie; Rault, Annie; Hedou, Celine; Soumet, Christophe; Verdon, Eric

2017-09-01

Efficient screening methods are needed to control antibiotic residues in eggs. A microbiological kit (Explorer® 2.0 test (Zeu Inmunotech, Spain)) and an immunobiosensor kit (Microarray II (AM® II) on Evidence Investigator™ system (Randox, UK)) have been evaluated and validated for screening of antibiotic residues in eggs, according to the European decision EC/2002/657 and to the European guideline for the validation of screening methods. The e-reader™ system, a new automatic incubator/reading system, was coupled to the Explorer 2.0 test. The AM II kit can detect residues of six different families of antibiotics in different matrices including eggs. For both tests, a different liquid/liquid extraction of eggs had to be developed. Specificities of the Explorer 2.0 and AM II kit were equal to 8% and 0% respectively. The detection capabilities were determined for 19 antibiotics, with representatives from different families, for Explorer 2.0 and 12 antibiotics for the AM II kit. For the nine antibiotics having a maximum residue limit (MRL) in eggs, the detection capabilities CCβ of Explorer 2.0 were below the MRL for four antibiotics, equal to the MRL for two antibiotics and between 1 and 1.5 MRLs for the three remaining antibiotics (tetracyclines). For the antibiotics from other families, the detection capabilities were low for beta-lactams and sulfonamides and satisfactory for dihydrostreptomycin (DHS) and fluoroquinolones, which are usually difficult to detect with microbiological tests. The CCβ values of the AM II kit were much lower than the respective MRLs for three detected antibiotics (tetracycline, oxytetracycline, tylosin). Concerning the nine other antibiotics, the detection capabilities determined were low. The highest CCβ was obtained for streptomycin (100 µg kg -1 ).

Glaucoma diagnostic ability of ganglion cell-inner plexiform layer thickness differs according to the location of visual field loss.

PubMed

Shin, Hye-Young; Park, Hae-Young Lopilly; Jung, Kyoung-In; Choi, Jin-A; Park, Chan Kee

2014-01-01

To determine whether the ganglion cell-inner plexiform layer (GCIPL) or circumpapillary retinal nerve fiber layer (cpRNFL) is better at distinguishing eyes with early glaucoma from normal eyes on the basis of the the initial location of the visual field (VF) damage. Retrospective, observational study. Eighty-four patients with early glaucoma and 43 normal subjects were enrolled. The patients with glaucoma were subdivided into 2 groups according to the location of VF damage: (1) an isolated parafoveal scotoma (PFS, N = 42) within 12 points of a central 10 degrees in 1 hemifield or (2) an isolated peripheral nasal step (PNS, N = 42) within the nasal periphery outside 10 degrees of fixation in 1 hemifield. All patients underwent macular and optic disc scanning using Cirrus high-definition optical coherence tomography (Carl Zeiss Meditec, Dublin, CA). The GCIPL and cpRNFL thicknesses were compared between groups. Areas under the receiver operating characteristic curves (AUCs) were calculated. Comparison of diagnostic ability using AUCs. The average and minimum GCIPL of the PFS group were significantly thinner than those of the PNS group, whereas there was no significant difference in the average retinal nerve fiber layer (RNFL) thickness between the 2 groups. The AUCs of the average (0.962) and minimum GCIPL (0.973) thicknesses did not differ from that of the average RNFL thickness (0.972) for discriminating glaucomatous changes between normal and all glaucoma eyes (P =0.566 and 0.974, respectively). In the PFS group, the AUCs of the average (0.988) and minimum GCIPL (0.999) thicknesses were greater than that of the average RNFL thickness (0.961, P =0.307 and 0.125, respectively). However, the AUCs of the average (0.936) and minimum GCIPL (0.947) thicknesses were lower than that of the average RNFL thickness (0.984) in the PNS group (P =0.032 and 0.069, respectively). The GCIPL parameters were more valuable than the cpRNFL parameters for detecting glaucoma in eyes with parafoveal VF loss, and the cpRNFL parameters were better than the GCIPL parameters for detecting glaucoma in eyes with peripheral VF loss. Clinicians should know that the diagnostic capability of macular GCIPL parameters depends largely on the location of the VF loss. Copyright © 2014 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

The Need for Improved Detection and Management of Adult-Onset Hearing Loss in Australia

PubMed Central

McMahon, Catherine M.; Gopinath, Bamini; Schneider, Julie; Reath, Jennifer; Hickson, Louise; Leeder, Stephen R.; Mitchell, Paul; Cowan, Robert

2013-01-01

Adult-onset hearing loss is insidious and typically diagnosed and managed several years after onset. Often, this is after the loss having led to multiple negative consequences including effects on employment, depressive symptoms, and increased risk of mortality. In contrast, the use of hearing aids is associated with reduced depression, longer life expectancy, and retention in the workplace. Despite this, several studies indicate high levels of unmet need for hearing health services in older adults and poor use of prescribed hearing aids, often leading to their abandonment. In Australia, the largest component of financial cost of hearing loss (excluding the loss of well-being) is due to lost workplace productivity. Nonetheless, the Australian public health system does not have an effective and sustainable hearing screening strategy to tackle the problem of poor detection of adult-onset hearing loss. Given the increasing prevalence and disease burden of hearing impairment in adults, two key areas are not adequately met in the Australian healthcare system: (1) early identification of persons with chronic hearing impairment; (2) appropriate and targeted referral of these patients to hearing health service providers. This paper reviews the current literature, including population-based data from the Blue Mountains Hearing Study, and suggests different models for early detection of adult-onset hearing loss. PMID:23710184

Evaluation of two-stage system for neutron measurement aiming at increase in count rate at Japan Atomic Energy Agency-Fusion Neutronics Source

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

Shinohara, K., E-mail: shinohara.koji@jaea.go.jp; Ochiai, K.; Sukegawa, A.

In order to increase the count rate capability of a neutron detection system as a whole, we propose a multi-stage neutron detection system. Experiments to test the effectiveness of this concept were carried out on Fusion Neutronics Source. Comparing four configurations of alignment, it was found that the influence of an anterior stage on a posterior stage was negligible for the pulse height distribution. The two-stage system using 25 mm thickness scintillator was about 1.65 times the count rate capability of a single detector system for d-D neutrons and was about 1.8 times the count rate capability for d-T neutrons.more » The results suggested that the concept of a multi-stage detection system will work in practice.« less

Integrated failure detection and management for the Space Station Freedom external active thermal control system

NASA Technical Reports Server (NTRS)

Mesloh, Nick; Hill, Tim; Kosyk, Kathy

1993-01-01

This paper presents the integrated approach toward failure detection, isolation, and recovery/reconfiguration to be used for the Space Station Freedom External Active Thermal Control System (EATCS). The on-board and on-ground diagnostic capabilities of the EATCS are discussed. Time and safety critical features, as well as noncritical failures, and the detection coverage for each provided by existing capabilities are reviewed. The allocation of responsibility between on-board software and ground-based systems, to be shown during ground testing at the Johnson Space Center, is described. Failure isolation capabilities allocated to the ground include some functionality originally found on orbit but moved to the ground to reduce on-board resource requirements. Complex failures requiring the analysis of multiple external variables, such as environmental conditions, heat loads, or station attitude, are also allocated to ground personnel.

Key Future Engineering Capabilities for Human Capital Retention

NASA Astrophysics Data System (ADS)

Sivich, Lorrie

Projected record retirements of Baby Boomer generation engineers have been predicted to result in significant losses of mission-critical knowledge in space, national security, and future scientific ventures vital to high-technology corporations. No comprehensive review or analysis of engineering capabilities has been performed to identify threats related to the specific loss of mission-critical knowledge posed by the increasing retirement of tenured engineers. Archival data from a single diversified Fortune 500 aerospace manufacturing engineering company's engineering career database were analyzed to ascertain whether relationships linking future engineering capabilities, engineering disciplines, and years of engineering experience could be identified to define critical knowledge transfer models. Chi square, logistic, and linear regression analyses were used to map patterns of discipline-specific, mission-critical knowledge using archival data of engineers' perceptions of engineering capabilities, key developmental experiences, and knowledge learned from their engineering careers. The results from the study were used to document key engineering future capabilities. The results were then used to develop a proposed human capital retention plan to address specific key knowledge gaps of younger engineers as veteran engineers retire. The potential for social change from this study involves informing leaders of aerospace engineering corporations on how to build better quality mentoring or succession plans to fill the void of lost knowledge from retiring engineers. This plan can secure mission-critical knowledge for younger engineers for current and future product development and increased global competitiveness in the technology market.

The Use of End-to-End Multicast Measurements for Characterizing Internal Network Behavior

DTIC Science & Technology

2002-08-01

dropping on the basis Random Early Detection ( RED ) [17] is another mechanism by which packet loss may become decorrelated. It remains to be seen whether...this mechanism will be widely deployed in communications networks. On the other hand, the use of RED to merely mark packets will not break correlations...Tail and Random Early Detection ( RED ) buffer discard methods, [17]. We compared the inferred loss and delay with actual probe loss and delay. We found

Wavelet Entropy and Directed Acyclic Graph Support Vector Machine for Detection of Patients with Unilateral Hearing Loss in MRI Scanning

PubMed Central

Wang, Shuihua; Yang, Ming; Du, Sidan; Yang, Jiquan; Liu, Bin; Gorriz, Juan M.; Ramírez, Javier; Yuan, Ti-Fei; Zhang, Yudong

2016-01-01

Highlights We develop computer-aided diagnosis system for unilateral hearing loss detection in structural magnetic resonance imaging.Wavelet entropy is introduced to extract image global features from brain images. Directed acyclic graph is employed to endow support vector machine an ability to handle multi-class problems.The developed computer-aided diagnosis system achieves an overall accuracy of 95.1% for this three-class problem of differentiating left-sided and right-sided hearing loss from healthy controls. Aim: Sensorineural hearing loss (SNHL) is correlated to many neurodegenerative disease. Now more and more computer vision based methods are using to detect it in an automatic way. Materials: We have in total 49 subjects, scanned by 3.0T MRI (Siemens Medical Solutions, Erlangen, Germany). The subjects contain 14 patients with right-sided hearing loss (RHL), 15 patients with left-sided hearing loss (LHL), and 20 healthy controls (HC). Method: We treat this as a three-class classification problem: RHL, LHL, and HC. Wavelet entropy (WE) was selected from the magnetic resonance images of each subjects, and then submitted to a directed acyclic graph support vector machine (DAG-SVM). Results: The 10 repetition results of 10-fold cross validation shows 3-level decomposition will yield an overall accuracy of 95.10% for this three-class classification problem, higher than feedforward neural network, decision tree, and naive Bayesian classifier. Conclusions: This computer-aided diagnosis system is promising. We hope this study can attract more computer vision method for detecting hearing loss. PMID:27807415

Wavelet Entropy and Directed Acyclic Graph Support Vector Machine for Detection of Patients with Unilateral Hearing Loss in MRI Scanning.

PubMed

Wang, Shuihua; Yang, Ming; Du, Sidan; Yang, Jiquan; Liu, Bin; Gorriz, Juan M; Ramírez, Javier; Yuan, Ti-Fei; Zhang, Yudong

2016-01-01

Highlights We develop computer-aided diagnosis system for unilateral hearing loss detection in structural magnetic resonance imaging.Wavelet entropy is introduced to extract image global features from brain images. Directed acyclic graph is employed to endow support vector machine an ability to handle multi-class problems.The developed computer-aided diagnosis system achieves an overall accuracy of 95.1% for this three-class problem of differentiating left-sided and right-sided hearing loss from healthy controls. Aim: Sensorineural hearing loss (SNHL) is correlated to many neurodegenerative disease. Now more and more computer vision based methods are using to detect it in an automatic way. Materials: We have in total 49 subjects, scanned by 3.0T MRI (Siemens Medical Solutions, Erlangen, Germany). The subjects contain 14 patients with right-sided hearing loss (RHL), 15 patients with left-sided hearing loss (LHL), and 20 healthy controls (HC). Method: We treat this as a three-class classification problem: RHL, LHL, and HC. Wavelet entropy (WE) was selected from the magnetic resonance images of each subjects, and then submitted to a directed acyclic graph support vector machine (DAG-SVM). Results: The 10 repetition results of 10-fold cross validation shows 3-level decomposition will yield an overall accuracy of 95.10% for this three-class classification problem, higher than feedforward neural network, decision tree, and naive Bayesian classifier. Conclusions: This computer-aided diagnosis system is promising. We hope this study can attract more computer vision method for detecting hearing loss.

Viral Diagnostics in Plants Using Next Generation Sequencing: Computational Analysis in Practice.

PubMed

Jones, Susan; Baizan-Edge, Amanda; MacFarlane, Stuart; Torrance, Lesley

2017-01-01

Viruses cause significant yield and quality losses in a wide variety of cultivated crops. Hence, the detection and identification of viruses is a crucial facet of successful crop production and of great significance in terms of world food security. Whilst the adoption of molecular techniques such as RT-PCR has increased the speed and accuracy of viral diagnostics, such techniques only allow the detection of known viruses, i.e., each test is specific to one or a small number of related viruses. Therefore, unknown viruses can be missed and testing can be slow and expensive if molecular tests are unavailable. Methods for simultaneous detection of multiple viruses have been developed, and (NGS) is now a principal focus of this area, as it enables unbiased and hypothesis-free testing of plant samples. The development of NGS protocols capable of detecting multiple known and emergent viruses present in infected material is proving to be a major advance for crops, nuclear stocks or imported plants and germplasm, in which disease symptoms are absent, unspecific or only triggered by multiple viruses. Researchers want to answer the question "how many different viruses are present in this crop plant?" without knowing what they are looking for: RNA-sequencing (RNA-seq) of plant material allows this question to be addressed. As well as needing efficient nucleic acid extraction and enrichment protocols, virus detection using RNA-seq requires fast and robust bioinformatics methods to enable host sequence removal and virus classification. In this review recent studies that use RNA-seq for virus detection in a variety of crop plants are discussed with specific emphasis on the computational methods implemented. The main features of a number of specific bioinformatics workflows developed for virus detection from NGS data are also outlined and possible reasons why these have not yet been widely adopted are discussed. The review concludes by discussing the future directions of this field, including the use of bioinformatics tools for virus detection deployed in analytical environments using cloud computing.

Final Report Nucleic Acid System - Hybrid PCR and Multiplex Assay Project Phase 2

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

Koopman, R P; Langlois, R G; Nasarabadi, S

2002-04-17

This report covers phase 2 (year 2) of the Nucleic Acid System--Hybrid PCR and Multiplex Assay project. The objective of the project is to reduce to practice the detection and identification of biological warfare pathogens by the nucleic acid recognition technique of PCR (polymerase chain reaction) in a multiplex mode using flow cytometry. The Hybrid instrument consists of a flow-through PCR module capable of handling a multiplexed PCR assay, a hybridizing module capable of hybridizing multiplexed PCR amplicons and beads, and a flow cytometer module for bead-based identification, all controlled by a single computer. Multiplex immunoassay using bead-based Luminex flowmore » cytometry is available, allowing rapid screening for many agents. PCR is highly specific and complements and verifies immunoassay. It can also be multiplexed and detection provided using the bead-based Luminex flow cytometer. This approach allows full access to the speed and 100-fold multiplex capability of flow cytometry for rapid screening as well as the accuracy and specificity of PCR. This project has two principal activities: (1) Design, build and test a prototype hybrid PCR/flow cytometer with the basic capabilities for rapid, broad spectrum detection and identification, and (2) Develop and evaluate multiplex flow analysis assay protocols and reagents for the simultaneous detection of PCR products. This project requires not only building operationally functional instrumentation but also developing the chemical assays for detection of priority pathogens. This involves development and evaluation of multiplex flow analysis assay protocols and reagents for the simultaneous detection of PCR products.« less

Evaluation and validation of a multi-residue method based on biochip technology for the simultaneous screening of six families of antibiotics in muscle and aquaculture products.

PubMed

Gaudin, Valérie; Hedou, Celine; Soumet, Christophe; Verdon, Eric

2016-01-01

The Evidence Investigator™ system (Randox, UK) is a biochip and semi-automated system. The microarray kit II (AM II) is capable of detecting several compounds belonging to different families of antibiotics: quinolones, ceftiofur, thiamphenicol, streptomycin, tylosin and tetracyclines. The performance of this innovative system was evaluated for the detection of antibiotic residues in new matrices, in muscle of different animal species and in aquaculture products. The method was validated according to the European Decision No. EC/2002/657 and the European guideline for the validation of screening methods, which represents a complete initial validation. The false-positive rate was equal to 0% in muscle and in aquaculture products. The detection capabilities CCβ for 12 validated antibiotics (enrofloxacin, difloxacin, ceftiofur, desfuroyl ceftiofur cysteine disulfide, thiamphenicol, florfenicol, tylosin, tilmicosin, streptomycin, dihydrostreptomycin, tetracycline, doxycycline) were all lower than the respective maximum residue limits (MRLs) in muscle from different animal origins (bovine, ovine, porcine, poultry). No cross-reactions were observed with other antibiotics, neither with the six detected families nor with other families of antibiotics. The AM II kit could be applied to aquaculture products but with higher detection capabilities from those in muscle. The detection capabilities CCβ in aquaculture products were respectively at 0.25, 0.10 and 0.5 of the respective MRL in aquaculture products for enrofloxacin, tylosin and oxytetracycline. The performance of the AM II kit has been compared with other screening methods and with the performance characteristics previously determined in honey.

Standoff laser-based spectroscopy for explosives detection

NASA Astrophysics Data System (ADS)

Gaft, M.; Nagli, L.

2007-10-01

Real time detection and identification of explosives at a standoff distance is a major issue in efforts to develop defense against so-called Improvised Explosive Devices (IED). It is recognized that the only technique, which is potentially capable to standoff detection of minimal amounts of explosives is laser-based spectroscopy. LDS activity is based on a combination of laser-based spectroscopic methods with orthogonal capabilities. Our technique belongs to trace detection, namely to its micro-particles variety. It is based on commonly held belief that surface contamination was very difficult to avoid and could be exploited for standoff detection. We has applied optical techniques including gated Raman and time-resolved luminescence spectroscopy for detection of main explosive materials, both factory and homemade. We developed and tested a Raman system for the field remote detection and identification of minimal amounts of explosives on relevant surfaces at a distance of up to 30 meters.

Universal explosive detection system for homeland security applications

NASA Astrophysics Data System (ADS)

Lee, Vincent Y.; Bromberg, Edward E. A.

2010-04-01

L-3 Communications CyTerra Corporation has developed a high throughput universal explosive detection system (PassPort) to automatically screen the passengers in airports without requiring them to remove their shoes. The technical approach is based on the patented energetic material detection (EMD) technology. By analyzing the results of sample heating with an infrared camera, one can distinguish the deflagration or decomposition of an energetic material from other clutters such as flammables and general background substances. This becomes the basis of a universal explosive detection system that does not require a library and is capable of detecting trace levels of explosives with a low false alarm rate. The PassPort is a simple turnstile type device and integrates a non-intrusive aerodynamic sampling scheme that has been shown capable of detecting trace levels of explosives on shoes. A detailed description of the detection theory and the automated sampling techniques, as well as the field test results, will be presented.

A Nanocoaxial-Based Electrochemical Sensor for the Detection of Cholera Toxin

NASA Astrophysics Data System (ADS)

Archibald, Michelle M.; Rizal, Binod; Connolly, Timothy; Burns, Michael J.; Naughton, Michael J.; Chiles, Thomas C.

2015-03-01

Sensitive, real-time detection of biomarkers is of critical importance for rapid and accurate diagnosis of disease for point of care (POC) technologies. Current methods do not allow for POC applications due to several limitations, including sophisticated instrumentation, high reagent consumption, limited multiplexing capability, and cost. Here, we report a nanocoaxial-based electrochemical sensor for the detection of bacterial toxins using an electrochemical enzyme-linked immunosorbent assay (ELISA) and differential pulse voltammetry (DPV). Proof-of-concept was demonstrated for the detection of cholera toxin (CT). The linear dynamic range of detection was 10 ng/ml - 1 μg/ml, and the limit of detection (LOD) was found to be 2 ng/ml. This level of sensitivity is comparable to the standard optical ELISA used widely in clinical applications. In addition to matching the detection profile of the standard ELISA, the nanocoaxial array provides a simple electrochemical readout and a miniaturized platform with multiplexing capabilities for the simultaneous detection of multiple biomarkers, giving the nanocoax a desirable advantage over the standard method towards POC applications. Sensitive, real-time detection of biomarkers is of critical importance for rapid and accurate diagnosis of disease for point of care (POC) technologies. Current methods do not allow for POC applications due to several limitations, including sophisticated instrumentation, high reagent consumption, limited multiplexing capability, and cost. Here, we report a nanocoaxial-based electrochemical sensor for the detection of bacterial toxins using an electrochemical enzyme-linked immunosorbent assay (ELISA) and differential pulse voltammetry (DPV). Proof-of-concept was demonstrated for the detection of cholera toxin (CT). The linear dynamic range of detection was 10 ng/ml - 1 μg/ml, and the limit of detection (LOD) was found to be 2 ng/ml. This level of sensitivity is comparable to the standard optical ELISA used widely in clinical applications. In addition to matching the detection profile of the standard ELISA, the nanocoaxial array provides a simple electrochemical readout and a miniaturized platform with multiplexing capabilities for the simultaneous detection of multiple biomarkers, giving the nanocoax a desirable advantage over the standard method towards POC applications. This work was supported by the National Institutes of Health (National Cancer Institute award No. CA137681 and National Institute of Allergy and Infectious Diseases Award No. AI100216).

The Integrated Design Plan for the Coastal Module of GOOS

NASA Astrophysics Data System (ADS)

Malone, T.; Knap, T.

2003-04-01

Changes in the ocean-climate system and land-use in coastal drainage basins are major drivers of change in coastal waters of the U.S. EEZ. Consequent changes in physical, biological, chemical and geological processes affect public health and well being, the health of coastal marine ecosystems, and the sustainability of living marine resources. Such changes are related through a hierarchy of interactions that can be represented by robust models of ecosystems dynamics. These observations make a compelling case for an ecosystem-based approach to the management of living marine resources, environmental protection, coastal zone management, and coastal engineering, especially in coastal systems where erosion, flooding, habitat alterations, over-fishing, water pollution, fish kills, invasions of non-indigenous species, and harmful algal blooms are collectively most severe. Implementing an ecosystem-based strategy requires the capability to engage in adaptive management, a decision-making activity that depends on the ability to (1) routinely and rapidly detect changes in the environment and living resources and to (2) provide timely predictions of changes in or the occurrence of the phenomena that affect the capacity of ecosystems to provide goods and services (from surface currents and coastal flooding to habitat modification and the loss of biodiversity). We do not have this capability today. Effective management and sustainable use also depend on efficient and timely coupling of the processes by which new scientific knowledge is gained and the fruits of this knowledge are used for the public good. Today, there is an unacceptable disconnect between these processes. A new approach to detecting and predicting environmental changes is needed that enables adaptive management through routine, continuous and rapid provision of data and information. The Coastal Module of the Global Ocean Observing System is being developed as part of the Integrated Global Observing Strategy to address this challenge. The observing system is not only needed to provide data and information on the time scales that environmental decisions should be made, it is needed to facilitate environmental research and to protect the integrity of the scientific method upon which the development of predictive capabilities depend.

ELER software - a new tool for urban earthquake loss assessment

NASA Astrophysics Data System (ADS)

Hancilar, U.; Tuzun, C.; Yenidogan, C.; Erdik, M.

2010-12-01

Rapid loss estimation after potentially damaging earthquakes is critical for effective emergency response and public information. A methodology and software package, ELER-Earthquake Loss Estimation Routine, for rapid estimation of earthquake shaking and losses throughout the Euro-Mediterranean region was developed under the Joint Research Activity-3 (JRA3) of the EC FP6 Project entitled "Network of Research Infrastructures for European Seismology-NERIES". Recently, a new version (v2.0) of ELER software has been released. The multi-level methodology developed is capable of incorporating regional variability and uncertainty originating from ground motion predictions, fault finiteness, site modifications, inventory of physical and social elements subjected to earthquake hazard and the associated vulnerability relationships. Although primarily intended for quasi real-time estimation of earthquake shaking and losses, the routine is also equally capable of incorporating scenario-based earthquake loss assessments. This paper introduces the urban earthquake loss assessment module (Level 2) of the ELER software which makes use of the most detailed inventory databases of physical and social elements at risk in combination with the analytical vulnerability relationships and building damage-related casualty vulnerability models for the estimation of building damage and casualty distributions, respectively. Spectral capacity-based loss assessment methodology and its vital components are presented. The analysis methods of the Level 2 module, i.e. Capacity Spectrum Method (ATC-40, 1996), Modified Acceleration-Displacement Response Spectrum Method (FEMA 440, 2005), Reduction Factor Method (Fajfar, 2000) and Coefficient Method (ASCE 41-06, 2006), are applied to the selected building types for validation and verification purposes. The damage estimates are compared to the results obtained from the other studies available in the literature, i.e. SELENA v4.0 (Molina et al., 2008) and ATC-55 (Yang, 2005). An urban loss assessment exercise for a scenario earthquake for the city of Istanbul is conducted and physical and social losses are presented. Damage to the urban environment is compared to the results obtained from similar software, i.e. KOERILoss (KOERI, 2002) and DBELA (Crowley et al., 2004). The European rapid loss estimation tool is expected to help enable effective emergency response, on both local and global level, as well as public information.

[Medical computer-aided detection method based on deep learning].

PubMed

Tao, Pan; Fu, Zhongliang; Zhu, Kai; Wang, Lili

2018-03-01

This paper performs a comprehensive study on the computer-aided detection for the medical diagnosis with deep learning. Based on the region convolution neural network and the prior knowledge of target, this algorithm uses the region proposal network, the region of interest pooling strategy, introduces the multi-task loss function: classification loss, bounding box localization loss and object rotation loss, and optimizes it by end-to-end. For medical image it locates the target automatically, and provides the localization result for the next stage task of segmentation. For the detection of left ventricular in echocardiography, proposed additional landmarks such as mitral annulus, endocardial pad and apical position, were used to estimate the left ventricular posture effectively. In order to verify the robustness and effectiveness of the algorithm, the experimental data of ultrasonic and nuclear magnetic resonance images are selected. Experimental results show that the algorithm is fast, accurate and effective.

BIOHAZ: Rapid On-Site Biological Detection for First Responders

DTIC Science & Technology

2001-09-01

numbers comprise the compilation report: ADP013371 thru ADP013468 UNCLASSIFIED 84. BIORAZ: Rapid On- Site Biological Detection for First Responders Randall... responders an integated capability to collect an environmental sample and to rapidly screen that sample on site for the presence of biological material. This...further analyzed on site with immunoassay tickets before being sent to a laboratory. This system provides the emergency responders with a capability that

Army Science and Technology Master Plan, Fiscal Year 1997 - Volume 1.

DTIC Science & Technology

1996-12-01

the EMW battlefield mission areas, mobility manportable mine detector, with the capability to detect both metallic and non- metallic minesand...b. Countermobility 98). The vehicular detector will demonstrate the mounted capability to detect metallic and Engineers impede the enemy’s freedom...This network pro- that will be effective against a wide variety of vides the commander with real-time targeting antitank and antipersonnel metallic and

Advanced Ground Systems Maintenance Enterprise Architecture Project

NASA Technical Reports Server (NTRS)

Harp, Janicce Leshay

2014-01-01

The project implements an architecture for delivery of integrated health management capabilities for the 21st Century launch complex. Capabilities include anomaly detection, fault isolation, prognostics and physics-based diagnostics.

The use of transient evoked otoacoustic emissions as a hearing screen following grommet insertion.

PubMed

Dale, O T; McCann, L J; Thio, D; Wells, S C; Drysdale, A J

2011-07-01

This study aimed to evaluate the sensitivity of transient evoked otoacoustic emission testing as a screening tool for hearing loss in children, after grommet insertion. A prospective study was conducted of 48 children (91 ears) aged three to 16 years who had undergone grommet insertion for glue ear. At post-operative review, pure tone audiometry was performed followed by transient evoked otoacoustic emission testing. Outcomes for both tests, in each ear, were compared. The pure tone audiometry threshold was ≤ 20 dB in 85 ears (93.4 per cent), 25 dB in two ears (2.2 per cent) and ≥ 30 dB in four ears (4.4 per cent). Transient evoked otoacoustic emissions were detected in 69 ears (75.8 per cent). The sensitivity of transient evoked otoacoustic emission testing for detecting hearing loss was 100 per cent for ≥ 30 dB loss but only 66.7 per cent for ≥ 25 dB loss. Transient evoked otoacoustic emission testing offers a sensitive means of detecting hearing loss of ≥ 30 dB following grommet insertion in children. However, the use of such testing as a screening tool may miss some cases of mild hearing loss.

Materials and Techniques for Implantable Nutrient Sensing Using Flexible Sensors Integrated with Metal-Organic Frameworks.

PubMed

Ling, Wei; Liew, Guoguang; Li, Ya; Hao, Yafeng; Pan, Huizhuo; Wang, Hanjie; Ning, Baoan; Xu, Hang; Huang, Xian

2018-06-01

The combination of novel materials with flexible electronic technology may yield new concepts of flexible electronic devices that effectively detect various biological chemicals to facilitate understanding of biological processes and conduct health monitoring. This paper demonstrates single- or multichannel implantable flexible sensors that are surface modified with conductive metal-organic frameworks (MOFs) such as copper-MOF and cobalt-MOF with large surface area, high porosity, and tunable catalysis capability. The sensors can monitor important nutriments such as ascorbicacid, glycine, l-tryptophan (l-Trp), and glucose with detection resolutions of 14.97, 0.71, 4.14, and 54.60 × 10 -6 m, respectively. In addition, they offer sensing capability even under extreme deformation and complex surrounding environment with continuous monitoring capability for 20 d due to minimized use of biological active chemicals. Experiments using live cells and animals indicate that the MOF-modified sensors are biologically safe to cells, and can detect l-Trp in blood and interstitial fluid. This work represents the first effort in integrating MOFs with flexible sensors to achieve highly specific and sensitive implantable electrochemical detection and may inspire appearance of more flexible electronic devices with enhanced capability in sensing, energy storage, and catalysis using various properties of MOFs. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Current Range Safety Capabilities

DTIC Science & Technology

1994-02-01

weights of up to 10 pounds. 12 (4) Tactical Aircraft Overpressure Signature Prediction. This interactive computer program accurately predicts the...Here the effect might be the loss of an aircraft and/or lives. "MINIMIZING PROCEDURES" are the things you plan to do to prevent the hazard from...occurrence is highly subjective end will dominate the discussion. The guidelnes below may be of some help. HAZARD CATEGORY CATASTROPHIC: Death. Loss of

Effect of storage, processing and cooking on glucosinolate content of Brassica vegetables.

PubMed

Song, Lijiang; Thornalley, Paul J

2007-02-01

Epidemiological studies have shown that consumption of Brassica vegetables decrease the risk of cancer. These associations are linked to dietary intake of glucosinolates and their metabolism to cancer preventive isothiocyanates. Bioavailability of glucosinolates and related isothiocyanates are influenced by storage and culinary processing of Brassica vegetables. In this work, the content of the 7 major glucosinolates in broccoli, Brussels sprouts, cauliflower and green cabbage and their stability under different storage and cooking conditions is examined. Glucosinolates and isothiocyanates were quantified by liquid chromatography with tandem mass spectrometric detection (LC-MS/MS). Isothiocyanates were detected with high sensitivity as the corresponding thiourea derivatives. Storage at ambient temperature and in a domestic refrigerator showed no significant difference and a minor loss (9-26%) of glucosinolate levels over 7 days. Vegetables shredded finely showed a marked decline of glucosinolate level with post-shredding dwell time - up to 75% over 6h. Glucosinolate losses were detected partly as isothiocyanates. Cooking by steaming, microwaving and stir-fry did not produce significant loss of glucosinolates whereas boiling showed significant losses by leaching into cooking water. Most of the loss of the glucosinolates (approximately 90%) was detected in the cooking water. Increased bioavailability of dietary isothiocyanates may be achieved by avoiding boiling of vegetables.

Short term hearing loss in general aviation operations, phase 1, part 1

NASA Technical Reports Server (NTRS)

Parker, J. F., Jr.

1972-01-01

The effects of light aircraft noise on six subjects during flight operations were investigated. The noise environment in the Piper Apache light aircraft was found to be capable of producing hearing threshold shifts. The following are the principal findings and conclusions: (1) Through most of the frequency range for which measurements were taken (500 to 6000 Hz), there was a regular progression showing increased loss of auditory acuity as a function of increased exposure time. (2) Extensive variability was found in the results among subjects, and in the measured loss at discrete frequencies for each subject. (3) The principal loss of hearing occurred at the low frequencies, around 500 Hz.

Effect of conductive hearing loss on central auditory function.

PubMed

Bayat, Arash; Farhadi, Mohammad; Emamdjomeh, Hesam; Saki, Nader; Mirmomeni, Golshan; Rahim, Fakher

It has been demonstrated that long-term Conductive Hearing Loss (CHL) may influence the precise detection of the temporal features of acoustic signals or Auditory Temporal Processing (ATP). It can be argued that ATP may be the underlying component of many central auditory processing capabilities such as speech comprehension or sound localization. Little is known about the consequences of CHL on temporal aspects of central auditory processing. This study was designed to assess auditory temporal processing ability in individuals with chronic CHL. During this analytical cross-sectional study, 52 patients with mild to moderate chronic CHL and 52 normal-hearing listeners (control), aged between 18 and 45 year-old, were recruited. In order to evaluate auditory temporal processing, the Gaps-in-Noise (GIN) test was used. The results obtained for each ear were analyzed based on the gap perception threshold and the percentage of correct responses. The average of GIN thresholds was significantly smaller for the control group than for the CHL group for both ears (right: p=0.004; left: p<0.001). Individuals with CHL had significantly lower correct responses than individuals with normal hearing for both sides (p<0.001). No correlation was found between GIN performance and degree of hearing loss in either group (p>0.05). The results suggest reduced auditory temporal processing ability in adults with CHL compared to normal hearing subjects. Therefore, developing a clinical protocol to evaluate auditory temporal processing in this population is recommended. Copyright © 2017 Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial. Published by Elsevier Editora Ltda. All rights reserved.

Short article: Relapsing Whipple's disease: a case report and literature review.

PubMed

Ruggiero, Elena; Zurlo, Anna; Giantin, Valter; Galeazzi, Francesca; Mescoli, Claudia; Nante, Giovanni; Petruzzellis, Florinda; Manzato, Enzo

2016-03-01

Whipple's disease is a rare infection caused by Tropheryma whipplei, a Gram-negative Bacillus usually found in macrophages of the lamina propria of the small intestine. The typical clinical manifestations of classic Whipple's disease are diarrhea, weight loss, malabsorption, abdominal pain, and arthralgia. The disease's laboratory diagnosis is currently based on duodenal biopsy. Treatment generally includes primary therapy for 2 weeks with intravenous antibiotics capable of reaching high levels in the cerebrospinal fluid, such as ceftriaxone, usually followed by treatment with oral cotrimoxazole for 1 year. Early diagnosis should enable appropriate treatment and improves the prognosis, and prolonged antibiotic treatment often leads to complete remission. Our case report focuses on a 72-year-old man who had been passing watery stools for 1-2 months, accompanied by low-grade fever. He reported profound asthenia, a weight loss of about 3 kg, and loss of appetite. Thirty years earlier (in 1984), he had been working as a horse keeper at a University Department of Agricultural and Veterinary Studies, where he had contracted Whipple's disease. Laboratory tests and microbiological studies led to a diagnosis of recurrent Whipple's disease. Esophagogastroduodenoscopy was performed under deep sedation. Biopsy samples obtained from the stomach and duodenum were stained with hematoxylin and eosin, Giemsa, and periodic acid-Schiff to identify any accumulation of typical periodic acid-Schiff-positive macrophages in the lamina propria. A specific quantitative real-time PCR assay using specific oligonucleotide probes for targeting repeated sequences of Tropheryma whipplei was also performed to detect its DNA in the duodenum samples.

Error detection and correction unit with built-in self-test capability for spacecraft applications

NASA Technical Reports Server (NTRS)

Timoc, Constantin

1990-01-01

The objective of this project was to research and develop a 32-bit single chip Error Detection and Correction unit capable of correcting all single bit errors and detecting all double bit errors in the memory systems of a spacecraft. We designed the 32-bit EDAC (Error Detection and Correction unit) based on a modified Hamming code and according to the design specifications and performance requirements. We constructed a laboratory prototype (breadboard) which was converted into a fault simulator. The correctness of the design was verified on the breadboard using an exhaustive set of test cases. A logic diagram of the EDAC was delivered to JPL Section 514 on 4 Oct. 1988.

Cross polarization optical coherence tomography for diagnosis of oral soft tissues

NASA Astrophysics Data System (ADS)

Gladkova, Natalia; Karabut, Maria; Kiseleva, Elena; Robakidze, Natalia; Muraev, Alexander; Fomina, Julia

2011-03-01

We consider the capabilities of cross-polarization OCT (CP OCT) focused on comparison of images resulting from cross-polarization and co-polarization scattering simultaneously for diagnosis of oral soft tissues. CP OCT was done for 35 patients with dental implants and 30 patients with inflammatory intestine diseases. Our study showed good diagnostic capabilities of CP OCT for detecting soft tissue pathology in the oral cavity. The cross-polarized images demonstrate the ability of tissue to depolarize. CP OCT demonstrates clinical capabilities for early diagnosis of inflammatory intestine diseases by the state of oral cavity mucosa and for early detection of gingivitis in patients above implant.

Detection of Visual Field Loss in Pituitary Disease: Peripheral Kinetic Versus Central Static

PubMed Central

Rowe, Fiona J.; Cheyne, Christopher P.; García-Fiñana, Marta; Noonan, Carmel P.; Howard, Claire; Smith, Jayne; Adeoye, Joanne

2015-01-01

Abstract Visual field assessment is an important clinical evaluation for eye disease and neurological injury. We evaluated Octopus semi-automated kinetic peripheral perimetry (SKP) and Humphrey static automated central perimetry for detection of neurological visual field loss in patients with pituitary disease. We carried out a prospective cross-sectional diagnostic accuracy study comparing Humphrey central 30-2 SITA threshold programme with a screening protocol for SKP on Octopus perimetry. Humphrey 24-2 data were extracted from 30-2 results. Results were independently graded for presence/absence of field defect plus severity of defect. Fifty patients (100 eyes) were recruited (25 males and 25 females), with mean age of 52.4 years (SD = 15.7). Order of perimeter assessment (Humphrey/Octopus first) and order of eye tested (right/left first) were randomised. The 30-2 programme detected visual field loss in 85%, the 24-2 programme in 80%, and the Octopus combined kinetic/static strategy in 100% of eyes. Peripheral visual field loss was missed by central threshold assessment. Qualitative comparison of type of visual field defect demonstrated a match between Humphrey and Octopus results in 58%, with a match for severity of defect in 50%. Tests duration was 9.34 minutes (SD = 2.02) for Humphrey 30-2 versus 10.79 minutes (SD = 4.06) for Octopus perimetry. Octopus semi-automated kinetic perimetry was found to be superior to central static testing for detection of pituitary disease-related visual field loss. Where reliant on Humphrey central static perimetry, the 30-2 programme is recommended over the 24-2 programme. Where kinetic perimetry is available, this is preferable to central static programmes for increased detection of peripheral visual field loss. PMID:27928344

Economic consequences of improved temperature forecasts: An experiment with the Florida citrus growers (control group results). Executive summary. [weather forecasting

NASA Technical Reports Server (NTRS)

1977-01-01

A demonstration experiment is being planned to show that frost and freeze prediction improvements are possible utilizing timely Synchronous Meteorological Satellite temperature measurements and that this information can affect Florida citrus grower operations and decisions so as to significantly reduce the cost for frost and freeze protection and crop losses. The design and implementation of the first phase of an economic experiment which will monitor citrus growers decisions, actions, costs and losses, and meteorological forecasts and actual weather events was carried out. The economic experiment was designed to measure the change in annual protection costs and crop losses which are the direct result of improved temperature forecasts. To estimate the benefits that may result from improved temperature forecasting capability, control and test groups were established with effective separation being accomplished temporally. The control group, utilizing current forecasting capability, was observed during the 1976-77 frost season and the results are reported. A brief overview is given of the economic experiment, the results obtained to date, and the work which still remains to be done.

Assessing the Effects of Multi-Node Sensor Network Configurations on the Operational Tempo

DTIC Science & Technology

2014-09-01

receiver, nP is the noise power of the receiver, and iL is the implementation loss of the receiver due to hardware manufacturing. The received...13. ABSTRACT (maximum 200 words) The LPISimNet software tool provides the capability to quantify the performance of sensor network configurations by...INTENTIONALLY LEFT BLANK v ABSTRACT The LPISimNet software tool provides the capability to quantify the performance of sensor network configurations

ELENA MCP detector: absolute efficiency measurement for low energy neutral atoms

NASA Astrophysics Data System (ADS)

Rispoli, R.; De Angelis, E.; Colasanti, L.; Vertolli, N.; Orsini, S.; Scheer, J.; Mura, A.; Milillo, A.; Wurz, P.; Selci, S.; Di Lellis, A. M.; Leoni, R.; D'Alessandro, M.; Mattioli, F.; Cibella, S.

2012-04-01

MicroChannel plates (MCP) detectors are frequently used in space instrumentation for detecting a wide range of radiation and particles. In particular, the capability to detect non-thermal low energy neutral species is crucial for the sensor ELENA (Emitted Low-Energy Neutral Atoms), part of the package SERENA (Search for Exospheric Refilling and Emitted Natural Abundances) on board the BepiColombo mission to Mercury to be launched in 2014. ELENA is a TOF sensor, based on a novel concept ultra-sonic oscillating shutter (Start section)which is operated at frequencies up to 50 kHz; a MCP detector is used as a Stop section. It is aimed to detect neutral atoms in the range 10 eV - 5 keV, within 70° FOV, perpendicular to the S/C orbital plane. ELENA will monitor the emission of neutral atoms from the whole surface of Mercury thanks to the spacecraft motion. The major scientific objectives are the interaction between the environment and the planet, the global particle loss-rate and the remote sensing of the surface properties. In particular, surface release processes are investigated by identifying particles release from the surface, via solar wind-induced ion sputtering (<1eV and >100 eV) as well as Hydrogen back-scattered at hundreds eV. MCP absolute detection efficiency for very low energy neutral atoms (E< 30eV) is a crucial point not yet investigated. At the MEFISTO facility of the Physical Institute of University of Bern (CH), measurements on three different type of MCPs coating have been performed providing the behaviors of MCP detection efficiency in the range 10eV-1keV. Outcomes from such measurements are here discussed.

Quantitative blood group typing using surface plasmon resonance.

PubMed

Then, Whui Lyn; Aguilar, Marie-Isabel; Garnier, Gil

2015-11-15

The accurate and reliable typing of blood groups is essential prior to blood transfusion. While current blood typing methods are well established, results are subjective and heavily reliant on analysis by trained personnel. Techniques for quantifying blood group antibody-antigen interactions are also very limited. Many biosensing systems rely on surface plasmon resonance (SPR) detection to quantify biomolecular interactions. While SPR has been widely used for characterizing antibody-antigen interactions, measuring antibody interactions with whole cells is significantly less common. Previous studies utilized SPR for blood group antigen detection, however, showed poor regeneration causing loss of functionality after a single use. In this study, a fully regenerable, multi-functional platform for quantitative blood group typing via SPR detection is achieved by immobilizing anti-human IgG antibody to the sensor surface, which binds to the Fc region of human IgG antibodies. The surface becomes an interchangeable platform capable of quantifying the blood group interactions between red blood cells (RBCs) and IgG antibodies. As with indirect antiglobulin tests (IAT), which use IgG antibodies for detection, IgG antibodies are initially incubated with RBCs. This facilitates binding to the immobilized monolayer and allows for quantitative blood group detection. Using the D-antigen as an example, a clear distinction between positive (>500 RU) and negative (<100 RU) RBCs is achieved using anti-D IgG. Complete regeneration of the anti-human IgG surface is also successful, showing negligible degradation of the surface after more than 100 regenerations. This novel approach is validated with human-sourced whole blood samples to demonstrate an interesting alternative for quantitative blood grouping using SPR analysis. Crown Copyright © 2015. Published by Elsevier B.V. All rights reserved.

Multiple fault separation and detection by joint subspace learning for the health assessment of wind turbine gearboxes

NASA Astrophysics Data System (ADS)

Du, Zhaohui; Chen, Xuefeng; Zhang, Han; Zi, Yanyang; Yan, Ruqiang

2017-09-01

The gearbox of a wind turbine (WT) has dominant failure rates and highest downtime loss among all WT subsystems. Thus, gearbox health assessment for maintenance cost reduction is of paramount importance. The concurrence of multiple faults in gearbox components is a common phenomenon due to fault induction mechanism. This problem should be considered before planning to replace the components of the WT gearbox. Therefore, the key fault patterns should be reliably identified from noisy observation data for the development of an effective maintenance strategy. However, most of the existing studies focusing on multiple fault diagnosis always suffer from inappropriate division of fault information in order to satisfy various rigorous decomposition principles or statistical assumptions, such as the smooth envelope principle of ensemble empirical mode decomposition and the mutual independence assumption of independent component analysis. Thus, this paper presents a joint subspace learning-based multiple fault detection (JSL-MFD) technique to construct different subspaces adaptively for different fault patterns. Its main advantage is its capability to learn multiple fault subspaces directly from the observation signal itself. It can also sparsely concentrate the feature information into a few dominant subspace coefficients. Furthermore, it can eliminate noise by simply performing coefficient shrinkage operations. Consequently, multiple fault patterns are reliably identified by utilizing the maximum fault information criterion. The superiority of JSL-MFD in multiple fault separation and detection is comprehensively investigated and verified by the analysis of a data set of a 750 kW WT gearbox. Results show that JSL-MFD is superior to a state-of-the-art technique in detecting hidden fault patterns and enhancing detection accuracy.

Lateral flow assay for rapid detection of white spot syndrome virus (WSSV) using a phage-displayed peptide as bio-recognition probe.

PubMed

Kulabhusan, Prabir Kumar; Rajwade, Jyutika M; Sahul Hameed, A S; Paknikar, Kishore M

2017-06-01

White spot disease caused by the white spot syndrome virus (WSSV) has a major socio-economic impact on shrimp farming in India. It has been realized that a field-usable diagnostic capable of rapid detection of WSSV can prevent huge economic losses in disease outbreaks. In this work, we explored the possibility of using a peptide as bio-recognition probe in a field-usable device for the detection of WSSV from infected shrimps and prawns. A commercially available random phage-display library was screened against rVP28 (a major structural protein of WSSV, expressed as a recombinant protein in Escherichia coli). A bacteriophage clone VP28-4L was obtained, and its binding to purified rVP28 protein as well as WSSV from infected shrimp Litopaeneus vannamei tissue was confirmed by ELISA and western blot. The apparent equilibrium dissociation constant (K d ,app) was calculated to be 810 nM. VP28-4L did not show cross-reactivity with any other shrimp viruses. A 12-mer peptide (pep28, with the sequence 'TFQAFDLSPFPS') displayed on the VP28-4L was synthesized, and its diagnostic potential was evaluated in a lateral flow assay (LFA). Visual detection of WSSV could be achieved using biotinylated-pep28 and streptavidin-conjugated gold nanoparticles. In LFA, 12.5 μg/mL of the virus could be detected from L. vannamei gill tissue homogenate within 20 min. Pep28 thus becomes an attractive candidate in bio-recognition of WSSV in field-usable diagnostic platforms benefitting the aquaculture sector.

Deep Spatial-Temporal Joint Feature Representation for Video Object Detection.

PubMed

Zhao, Baojun; Zhao, Boya; Tang, Linbo; Han, Yuqi; Wang, Wenzheng

2018-03-04

With the development of deep neural networks, many object detection frameworks have shown great success in the fields of smart surveillance, self-driving cars, and facial recognition. However, the data sources are usually videos, and the object detection frameworks are mostly established on still images and only use the spatial information, which means that the feature consistency cannot be ensured because the training procedure loses temporal information. To address these problems, we propose a single, fully-convolutional neural network-based object detection framework that involves temporal information by using Siamese networks. In the training procedure, first, the prediction network combines the multiscale feature map to handle objects of various sizes. Second, we introduce a correlation loss by using the Siamese network, which provides neighboring frame features. This correlation loss represents object co-occurrences across time to aid the consistent feature generation. Since the correlation loss should use the information of the track ID and detection label, our video object detection network has been evaluated on the large-scale ImageNet VID dataset where it achieves a 69.5% mean average precision (mAP).

Method and system for monitoring environmental conditions

DOEpatents

Kulesz, James J [Oak Ridge, TN; Lee, Ronald W [Oak Ridge, TN

2010-11-16

A system for detecting the occurrence of anomalies includes a plurality of spaced apart nodes, with each node having adjacent nodes, each of the nodes having one or more sensors associated with the node and capable of detecting anomalies, and each of the nodes having a controller connected to the sensors associated with the node. The system also includes communication links between adjacent nodes, whereby the nodes form a network. At least one software agent is capable of changing the operation of at least one of the controllers in response to the detection of an anomaly by a sensor.

Advanced Ground Systems Maintenance Enterprise Architecture Project

NASA Technical Reports Server (NTRS)

Perotti, Jose M. (Compiler)

2015-01-01

The project implements an architecture for delivery of integrated health management capabilities for the 21st Century launch complex. The delivered capabilities include anomaly detection, fault isolation, prognostics and physics based diagnostics.

DNA-based species detection capabilities using laser transmission spectroscopy

PubMed Central

Mahon, A. R.; Barnes, M. A.; Li, F.; Egan, S. P.; Tanner, C. E.; Ruggiero, S. T.; Feder, J. L.; Lodge, D. M.

2013-01-01

Early detection of invasive species is critical for effective biocontrol to mitigate potential ecological and economic damage. Laser transmission spectroscopy (LTS) is a powerful solution offering real-time, DNA-based species detection in the field. LTS can measure the size, shape and number of nanoparticles in a solution and was used here to detect size shifts resulting from hybridization of the polymerase chain reaction product to nanoparticles functionalized with species-specific oligonucleotide probes or with the species-specific oligonucleotide probes alone. We carried out a series of DNA detection experiments using the invasive freshwater quagga mussel (Dreissena bugensis) to evaluate the capability of the LTS platform for invasive species detection. Specifically, we tested LTS sensitivity to (i) DNA concentrations of a single target species, (ii) the presence of a target species within a mixed sample of other closely related species, (iii) species-specific functionalized nanoparticles versus species-specific oligonucleotide probes alone, and (iv) amplified DNA fragments versus unamplified genomic DNA. We demonstrate that LTS is a highly sensitive technique for rapid target species detection, with detection limits in the picomolar range, capable of successful identification in multispecies samples containing target and non-target species DNA. These results indicate that the LTS DNA detection platform will be useful for field application of target species. Additionally, we find that LTS detection is effective with species-specific oligonucleotide tags alone or when they are attached to polystyrene nanobeads and with both amplified and unamplified DNA, indicating that the technique may also have versatility for broader applications. PMID:23015524

Development of a wireless, self-sustaining damage detection sensor system based on chemiluminescence for structural health monitoring

NASA Astrophysics Data System (ADS)

Kuang, K. S. C.

2014-03-01

A novel application of chemiluminescence resulting from the chemical reaction in a glow-stick as sensors for structural health monitoring is demonstrated here. By detecting the presence of light emitting from these glow-sticks, it is possible to develop a low-cost sensing device with the potential to provide early warning of damage in a variety of engineering applications such as monitoring of cracks or damage in concrete shear walls, detecting of ground settlement, soil liquefaction, slope instability, liquefaction-related damage of underground structure and others. In addition, this paper demonstrates the ease of incorporating wireless capability to the sensor device and the possibility of making the sensor system self-sustaining by means of a renewable power source for the wireless module. A significant advantage of the system compared to previous work on the use of plastic optical fibre (POF) for damage detection is that here the system does not require an electrically-powered light source. Here, the sensing device, embedded in a cement host, is shown to be capable of detecting damage. A series of specimens with embedded glow-sticks have been investigated and an assessment of their damage detection capability will be reported. The specimens were loaded under flexure and the sensor responses were transmitted via a wireless connection.

Optical detection of special nuclear materials: an alternative approach for standoff and remote sensing

NASA Astrophysics Data System (ADS)

Johnson, J. Bruce; Reeve, S. W.; Burns, W. A.; Allen, Susan D.

2010-04-01

Termed Special Nuclear Material (SNM) by the Atomic Energy Act of 1954, fissile materials, such as 235U and 239Pu, are the primary components used to construct modern nuclear weapons. Detecting the clandestine presence of SNM represents an important capability for Homeland Security. An ideal SNM sensor must be able to detect fissile materials present at ppb levels, be able to distinguish between the source of the detected fissile material, i.e., 235U, 239Pu, 233U or other fission source, and be able to perform the discrimination in near real time. A sensor with such capabilities would provide not only rapid identification of a threat but, ultimately, information on the potential source of the threat. For example, current detection schemes for monitoring clandestine nuclear testing and nuclear fuel reprocessing to provide weapons grade fissile material rely largely on passive air sampling combined with a subsequent instrumental analysis or some type of wet chemical analysis of the collected material. It would be highly useful to have a noncontact method of measuring isotopes capable of providing forensic information rapidly at ppb levels of detection. Here we compare the use of Kr, Xe and I as "canary" species for distinguishing between 235U and 239Pu fission sources by spectroscopic methods.

Self-efficacy moderates message-framing effects: The case of skin-cancer detection.

PubMed

van 't Riet, Jonathan; Ruiter, Robert A C; Werrij, Marieke Q; De Vries, Hein

2010-03-01

Health-promoting messages can be framed in terms of the gains associated with healthy behaviour, or the losses associated with unhealthy behaviour. Studies show inconsistent results as to which type of framing is more effective. In this study, we examined the influence of self-efficacy to perform skin self-examination on the effects of gain- and loss-framed skin-cancer detection messages among 124 university students. For participants with high self-efficacy, a loss-framed message resulted in a higher intention to perform skin self-examination than a gain-framed message. For participants with low self-efficacy, there were no differences in intention between the gain- and loss-framed message conditions. Our results suggest that self-efficacy levels play an important role in message-framing effects. For health communication strategies promoting the active detection of skin-cancer symptoms, messages stressing losses may be more effective than messages stressing gains, but only in persons with high self-efficacy. In addition, our results suggest that health promoting messages can be framed to match recipients' self-efficacy levels.

Zeolite Degradation: An Investigation of CO2 Capacity Loss of 13x Sorbent

NASA Technical Reports Server (NTRS)

Huang, Roger; Richardson, Tra-My Justine; Belancik, Grace; Jan, Darrell; Hogan, John; Knox, James C.

2017-01-01

System testing of the Carbon Dioxide Removal and Compression System (CRCS) has revealed that sufficient CO2 removal capability was not achieved with the designed system. Subsystem component analysis of the zeolite bed revealed that the sorbent material suffered significant degradation and CO2 loading capacity loss. In an effort to find the root cause of this degradation, various factors were investigated to try to reproduce the observed performance loss. These factors included contamination by vacuum pump oil, o-ring vacuum grease, loading/unloading procedures, and operations. This paper details the experiments that were performed and their results.

Coupling loss reducing for fiber Raman gas detection technology

NASA Astrophysics Data System (ADS)

Hu, Jialin; Jiang, Shubo; Zhang, Xiumei

2017-01-01

During the design of the photonic crystal fiber Raman gas detection device and taking the cost and practicability in to consideration, we choose to use a stainless steel tube as a connector for the connecting of the HCPCF and SMF to replace the fiber fusing splice. Basis on the measurement to reduce coupling loss, we calculated the optimum fiber gap for maximum light coupling and to reduce Fresnel loss. Using the stainless steel tube not only result in low loss but also benefit input of the sample gas and recycling of the fiber which is very expensive. By adjusting the central alignment of the stainless steel tube we can easily control the fiber deviation loss for specific type of SMF and HCPCF. The mode mismatch is also demonstrated.

Post-operative monitoring of free muscle transfers by Laser Doppler Imaging: A prospective study.

PubMed

Tschumi, Christian; Seyed Jafari, S Morteza; Rothenberger, Jens; Van de Ville, Dimitri; Keel, Marius; Krause, Fabian; Shafighi, Maziar

2015-10-01

Despite different existing methods, monitoring of free muscle transfer is still challenging. In the current study we evaluated our clinical setting regarding monitoring of such tissues, using a recent microcirculation-imaging camera (EasyLDI) as an additional tool for detection of perfusion incompetency. This study was performed on seven patients with soft tissue defect, who underwent reconstruction with free gracilis muscle. Beside standard monitoring protocol (clinical assessment, temperature strips, and surface Doppler), hourly EasyLDI monitoring was performed for 48 hours. Thereby a baseline value (raised flap but connected to its vascular bundle) and an ischaemia perfusion value (completely resected flap) were measured at the same point. The mean age of the patients, mean baseline value, ischaemia value perfusion were 48.00 ± 13.42 years, 49.31 ± 17.33 arbitrary perfusion units (APU), 9.87 ± 4.22 APU, respectively. The LDI measured values in six free muscle transfers were compatible with hourly standard monitoring protocol, and normalized LDI values significantly increased during time (P < 0.001, r = 0.412). One of the flaps required a return to theatre 17 hours after the operation, where an unsalvageable flap loss was detected. All normalized LDI values of this flap were under the ischaemia perfusion level and the trend was significantly descending during time (P < 0.001, r = -0.870). Due to the capability of early detection of perfusion incompetency, LDI may be recommended as an additional post-operative monitoring device for free muscle flaps, for early detection of suspected failing flaps and for validation of other methods. © 2015 Wiley Periodicals, Inc.

Image computing techniques to extrapolate data for dust tracking in case of an experimental accident simulation in a nuclear fusion plant.

PubMed

Camplani, M; Malizia, A; Gelfusa, M; Barbato, F; Antonelli, L; Poggi, L A; Ciparisse, J F; Salgado, L; Richetta, M; Gaudio, P

2016-01-01

In this paper, a preliminary shadowgraph-based analysis of dust particles re-suspension due to loss of vacuum accident (LOVA) in ITER-like nuclear fusion reactors has been presented. Dust particles are produced through different mechanisms in nuclear fusion devices, one of the main issues is that dust particles are capable of being re-suspended in case of events such as LOVA. Shadowgraph is based on an expanded collimated beam of light emitted by a laser or a lamp that emits light transversely compared to the flow field direction. In the STARDUST facility, the dust moves in the flow, and it causes variations of refractive index that can be detected by using a CCD camera. The STARDUST fast camera setup allows to detect and to track dust particles moving in the vessel and then to obtain information about the velocity field of dust mobilized. In particular, the acquired images are processed such that per each frame the moving dust particles are detected by applying a background subtraction technique based on the mixture of Gaussian algorithm. The obtained foreground masks are eventually filtered with morphological operations. Finally, a multi-object tracking algorithm is used to track the detected particles along the experiment. For each particle, a Kalman filter-based tracker is applied; the particles dynamic is described by taking into account position, velocity, and acceleration as state variable. The results demonstrate that it is possible to obtain dust particles' velocity field during LOVA by automatically processing the data obtained with the shadowgraph approach.

Image computing techniques to extrapolate data for dust tracking in case of an experimental accident simulation in a nuclear fusion plant

NASA Astrophysics Data System (ADS)

Camplani, M.; Malizia, A.; Gelfusa, M.; Barbato, F.; Antonelli, L.; Poggi, L. A.; Ciparisse, J. F.; Salgado, L.; Richetta, M.; Gaudio, P.

2016-01-01

In this paper, a preliminary shadowgraph-based analysis of dust particles re-suspension due to loss of vacuum accident (LOVA) in ITER-like nuclear fusion reactors has been presented. Dust particles are produced through different mechanisms in nuclear fusion devices, one of the main issues is that dust particles are capable of being re-suspended in case of events such as LOVA. Shadowgraph is based on an expanded collimated beam of light emitted by a laser or a lamp that emits light transversely compared to the flow field direction. In the STARDUST facility, the dust moves in the flow, and it causes variations of refractive index that can be detected by using a CCD camera. The STARDUST fast camera setup allows to detect and to track dust particles moving in the vessel and then to obtain information about the velocity field of dust mobilized. In particular, the acquired images are processed such that per each frame the moving dust particles are detected by applying a background subtraction technique based on the mixture of Gaussian algorithm. The obtained foreground masks are eventually filtered with morphological operations. Finally, a multi-object tracking algorithm is used to track the detected particles along the experiment. For each particle, a Kalman filter-based tracker is applied; the particles dynamic is described by taking into account position, velocity, and acceleration as state variable. The results demonstrate that it is possible to obtain dust particles' velocity field during LOVA by automatically processing the data obtained with the shadowgraph approach.

An initial evaluation of a proof-of-concept 128-Hz electronic tuning fork in the detection of peripheral neuropathy.

PubMed

O'Brien, Todd; Karem, Joseph

2014-03-01

Diabetic peripheral neuropathy (DPN) is an essential precursor leading to diabetic limb loss. Neurologic screening tests, including the 128-Hz tuning fork (TF), have long been used to identify and track the progression of DPN, thereby guiding the implementation of preventive strategies. Although a sensitive indicator of neuropathy, shortcomings of TF testing include the lack of standardization and quantification of clinical findings. In an attempt to overcome these limitations, a novel 128-Hz electronic TF (ETF) prototype has been developed that is capable of performing accurate timed vibration tests (TVTs). This study was designed to assess the ability of the ETF to detect sensory impairment compared with three established neurologic screening methods: the Semmes-Weinstein monofilament test, the biothesiometer, and the sharp/dull discrimination test. Fifty-five test patients were recruited from the primary author's practice and enrolled according to an approved protocol. The 10-g Semmes-Weinstein monofilament test and the sharp/dull discrimination test were administered in standard fashion to the plantar aspects of digits 1 and 5 bilaterally. The ETF and the biothesiometer (25-V setting) were applied to the dorsal aspects of the distal phalanx of the hallux and fifth metatarsal head bilaterally. The sensitivity and specificity of neuropathy detection for the ETF were 0.953 and 0.761, respectively, using conventional tests as reference standards. Performance of TVTs with the ETF detected sensory impairment compared with three conventional neurologic screening methods. Given these findings, the ETF could facilitate the use of standardized TVTs as an indicator of DPN progression.

Insulation board and process of making

DOEpatents

Nowobilski, Jeffert J.; Owens, William J.

1985-01-01

Insulation board capable of bearing a load without significant loss of insulating capacity due to compression, produced by a method wherein the board is made in compliance with specified conditions of time, temperature and pressure.

7 CFR 12.1 - General.

Code of Federal Regulations, 2011 CFR

2011-01-01

...— (1) Reduce soil loss due to wind and water erosion; (2) Protect the Nation's long-term capability to produce food and fiber; (3) Reduce sedimentation and improve water quality; and (4) Assist in preserving...

7 CFR 12.1 - General.

Code of Federal Regulations, 2010 CFR

2010-01-01

...— (1) Reduce soil loss due to wind and water erosion; (2) Protect the Nation's long-term capability to produce food and fiber; (3) Reduce sedimentation and improve water quality; and (4) Assist in preserving...

State of the art in perceptual design of hearing aids

NASA Astrophysics Data System (ADS)

Edwards, Brent W.; van Tasell, Dianne J.

2002-05-01

Hearing aid capabilities have increased dramatically over the past six years, in large part due to the development of small, low-power digital signal processing chips suitable for hearing aid applications. As hearing aid signal processing capabilities increase, there will be new opportunities to apply perceptually based knowledge to technological development. Most hearing loss compensation techniques in today's hearing aids are based on simple estimates of audibility and loudness. As our understanding of the psychoacoustical and physiological characteristics of sensorineural hearing loss improves, the result should be improved design of hearing aids and fitting methods. The state of the art in hearing aids will be reviewed, including form factors, user requirements, and technology that improves speech intelligibility, sound quality, and functionality. General areas of auditory perception that remain unaddressed by current hearing aid technology will be discussed.

Lunar Surface Operations. Part 1; Post-Touchdown Lunar Surface and System Checkouts

NASA Technical Reports Server (NTRS)

Interbartolo, Michael

2009-01-01

This slide presentation reviews the first part of the post-touchdown lunar surface and system checkout tasks. A stay/no stay decision for the lunar lander was made based on the questions: "Is the Lunar Module (LM) stable on the lunar surface?"; "Are there any time critical systems failures or trends indicating impending loss of capability to ascent and achieve a safe lunar orbit?"; and "Is there loss of capability in critical LM systems?" The sequence of these decisions is given as a time after touchdown on the surface of the moon. After the decision to stay is made the next task is to checkout status of the lunar module. While the status of the lunar module is checking out certain conditions, the Command Service Module was also engaged in certain checkout activities.

Aluminum Toxicity Is Associated with Mitochondrial Dysfunction and the Production of Reactive Oxygen Species in Plant Cells1

PubMed Central

Yamamoto, Yoko; Kobayashi, Yukiko; Devi, S. Rama; Rikiishi, Sanae; Matsumoto, Hideaki

2002-01-01

Potential mechanisms of Al toxicity measured as Al-induced inhibition of growth in cultured tobacco cells (Nicotiana tabacum, nonchlorophyllic cell line SL) and pea (Pisum sativum) roots were investigated. Compared with the control treatment without Al, the accumulation of Al in tobacco cells caused instantaneously the repression of mitochondrial activities [monitored by the reduction of 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide and the uptake of Rhodamine 123] and, after a lag of about 12 h, triggered reactive oxygen species (ROS) production, respiration inhibition, ATP depletion, and the loss of growth capability almost simultaneously. The presence of an antioxidant, butylated hydroxyanisol, during Al treatment of SL cells prevented not only ROS production but also ATP depletion and the loss of growth capability, suggesting that the Al-triggered ROS production seems to be a cause of ATP depletion and the loss of growth capability. Furthermore, these three late events were similarly repressed in an Al-tolerant cell line (ALT301) isolated from SL cells, suggesting that the acquisition of antioxidant functions mimicking butylated hydroxyanisol can be a mechanism of Al tolerance. In the pea root, Al also triggered ROS production, respiration inhibition, and ATP depletion, which were all correlated with inhibition of root elongation. Taken together, we conclude that Al affects mitochondrial functions, which leads to ROS production, probably the key critical event in Al inhibition of cell growth. PMID:11788753

The Global Detection Capability of the IMS Seismic Network in 2013 Inferred from Ambient Seismic Noise Measurements

NASA Astrophysics Data System (ADS)

Gaebler, P. J.; Ceranna, L.

2016-12-01

All nuclear explosions - on the Earth's surface, underground, underwater or in the atmosphere - are banned by the Comprehensive Nuclear-Test-Ban Treaty (CTBT). As part of this treaty, a verification regime was put into place to detect, locate and characterize nuclear explosion testings at any time, by anyone and everywhere on the Earth. The International Monitoring System (IMS) plays a key role in the verification regime of the CTBT. Out of the different monitoring techniques used in the IMS, the seismic waveform approach is the most effective technology for monitoring nuclear underground testing and to identify and characterize potential nuclear events. This study introduces a method of seismic threshold monitoring to assess an upper magnitude limit of a potential seismic event in a certain given geographical region. The method is based on ambient seismic background noise measurements at the individual IMS seismic stations as well as on global distance correction terms for body wave magnitudes, which are calculated using the seismic reflectivity method. From our investigations we conclude that a global detection threshold of around mb 4.0 can be achieved using only stations from the primary seismic network, a clear latitudinal dependence for the detection thresholdcan be observed between northern and southern hemisphere. Including the seismic stations being part of the auxiliary seismic IMS network results in a slight improvement of global detection capability. However, including wave arrivals from distances greater than 120 degrees, mainly PKP-wave arrivals, leads to a significant improvement in average global detection capability. In special this leads to an improvement of the detection threshold on the southern hemisphere. We further investigate the dependence of the detection capability on spatial (latitude and longitude) and temporal (time) parameters, as well as on parameters such as source type and percentage of operational IMS stations.

Characterization of the Resource Potential of Martian Soil using the Integrated Dust/Soil Experiment Package (IDEP)

NASA Technical Reports Server (NTRS)

Cooper, Bonnie L.; Mckay, David S.; Allen, Carlton C.; Hoffman, John H.; Gittleman, Mark E.

1997-01-01

The Integrated Dust/Soil Experiment Package (IDEP) is a suite of instruments that can detect and quantify the abundances of useful raw materials on Mars. We focus here on its capability for resource characterization in the martian soil; however, it is also capable of detecting and quantifying gases in the atmosphere. This paper describes the scientific rationale and the engineering design behind the IDEP.

Seeing Eye Drones: How The DOD Can Transform CBM And Disaster Response In The Homeland

DTIC Science & Technology

2016-12-01

thesis explores the possibility of integrating small unmanned aircraft systems (sUAS) with video capability and CBRN detection and identification sensors...small, unmanned aircraft systems (sUAS) with video capability and CBRN detection and identification sensors for use by National Guard civil support...CBRN) and hazardous material (HAZMAT) materials, as well as providing video to the incident commander. One of the primary benefits of providing

Watt-Level Continuous-Wave Emission from a Bifunctional Quantum Cascade Laser/Detector

PubMed Central

2017-01-01

Bifunctional active regions, capable of light generation and detection at the same wavelength, allow a straightforward realization of the integrated mid-infrared photonics for sensing applications. Here, we present a high performance bifunctional device for 8 μm capable of 1 W single facet continuous wave emission at 15 °C. Apart from the general performance benefits, this enables sensing techniques which rely on continuous wave operation, for example, heterodyne detection, to be realized within a monolithic platform and demonstrates that bifunctional operation can be realized at longer wavelength, where wavelength matching becomes increasingly difficult and that the price to be paid in terms of performance is negligible. In laser operation, the device has the same or higher efficiency compared to the best lattice-matched QCLs without same wavelength detection capability, which is only 30% below the record achieved with strained material at this wavelength. PMID:28540324

Results from Automated Cloud and Dust Devil Detection Onboard the MER

NASA Technical Reports Server (NTRS)

Chien, Steve; Castano, Rebecca; Bornstein, Benjamin; Fukunaga, Alex; Castano, Andres; Biesiadecki, Jeffrey; Greeley, Ron; Whelley, Patrick; Lemmon, Mark

2008-01-01

We describe a new capability to automatically detect dust devils and clouds in imagery onboard rovers, enabling downlink of just the images with the targets or only portions of the images containing the targets. Previously, the MER rovers conducted campaigns to image dust devils and clouds by commanding a set of images be collected at fixed times and downloading the entire image set. By increasing the efficiency of the campaigns, more campaigns can be executed. Software for these new capabilities was developed, tested, integrated, uploaded, and operationally checked out on both rovers as part of the R9.2 software upgrade. In April 2007 on Sol 1147 a dust devil was automatically detected onboard the Spirit rover for the first time. We discuss the operational usage of the capability and present initial dust devil results showing how this preliminary application has demonstrated the feasibility and potential benefits of the approach.

Spatial interactions reveal inhibitory cortical networks in human amblyopia.

PubMed

Wong, Erwin H; Levi, Dennis M; McGraw, Paul V

2005-10-01

Humans with amblyopia have a well-documented loss of sensitivity for first-order, or luminance defined, visual information. Recent studies show that they also display a specific loss of sensitivity for second-order, or contrast defined, visual information; a type of image structure encoded by neurons found predominantly in visual area A18/V2. In the present study, we investigate whether amblyopia disrupts the normal architecture of spatial interactions in V2 by determining the contrast detection threshold of a second-order target in the presence of second-order flanking stimuli. Adjacent flanks facilitated second-order detectability in normal observers. However, in marked contrast, they suppressed detection in each eye of the majority of amblyopic observers. Furthermore, strabismic observers with no loss of visual acuity show a similar pattern of detection suppression. We speculate that amblyopia results in predominantly inhibitory cortical interactions between second-order neurons.

Oral-Fluid Thiol-Detection Test Identifies Underlying Active Periodontal Disease Not Detected by the Visual Awake Examination.

PubMed

Queck, Katherine E; Chapman, Angela; Herzog, Leslie J; Shell-Martin, Tamara; Burgess-Cassler, Anthony; McClure, George David

Periodontal disease in dogs is highly prevalent but can only be accurately diagnosed by performing an anesthetized oral examination with periodontal probing and dental radiography. In this study, 114 dogs had a visual awake examination of the oral cavity and were administered an oral-fluid thiol-detection test prior to undergoing a a full-mouth anesthetized oral examination and digital dental radiographs. The results show the visual awake examination underestimated the presence and severity of active periodontal disease. The thiol-detection test was superior to the visual awake examination at detecting the presence and severity of active periodontal disease and was an indicator of progression toward alveolar bone loss. The thiol-detection test detected active periodontal disease at early stages of development, before any visual cues were present, indicating the need for intervention to prevent periodontal bone loss. Early detection is important because without intervention, dogs with gingivitis (active periodontal disease) progress to irreversible periodontal bone loss (stage 2+). As suggested in the current AAHA guidelines, a thiol-detection test administered in conjunction with the visual awake examination during routine wellness examinations facilitates veterinarian-client communication and mitigates under-diagnosis of periodontal disease and underutilization of dental services. The thiol-detection test can be used to monitor the periodontal health status of the conscious patient during follow-up examinations based on disease severity.

46 CFR 27.203 - What are the requirements for fire detection on towing vessels?

Code of Federal Regulations, 2010 CFR

2010-10-01

... detection on towing vessels? You must have a fire-detection system installed on your vessel to detect engine... use an existing engine-room-monitoring system (with fire-detection capability) instead of a fire-detection system, if the monitoring system is operable and complies with this section. You must ensure that...

Soil losses in rural watersheds with environmental land use conflicts.

PubMed

Pacheco, F A L; Varandas, S G P; Sanches Fernandes, L F; Valle Junior, R F

2014-07-01

Soil losses were calculated in a rural watershed where environmental land use conflicts developed in the course of a progressive invasion of forest and pasture/forest lands by agriculture, especially vineyards. The hydrographic basin is located in the Douro region where the famous Port wine is produced (northern Portugal) and the soil losses were estimated by the Universal Soil Loss Equation (USLE) in combination with a Geographic Information System (GIS). Environmental land use conflicts were set up on the basis of land use and land capability maps, coded as follows: 1-agriculture, 2-pasture, 3-pasture/forest, and 4-forest. The difference between the codes of capability and use defines a conflict class, where a negative or nil value means no conflict and a positive i value means class i conflict. The reliability of soil loss estimates was tested by a check of these values against the frequency of stone wall instabilities in vineyard terraces, with good results. Using the USLE, the average soil loss (A) was estimated in A=12.2 t·ha(-1)·yr(-1) and potential erosion risk areas were found to occupy 28.3% of the basin, defined where soil losses are larger than soil loss tolerances. Soil losses in no conflict regions (11.2 t·ha(-1)·yr(-1)) were significantly different from those in class 2 (6.8 t·ha(-1)·yr(-1)) and class 3 regions (21.3 t·ha(-1)·yr(-1)) that in total occupy 2.62 km(2) (14.3% of the basin). When simulating a scenario of no conflict across the entire basin, whereby land use in class 2 conflict regions is set up to permanent pastures and in class 3 conflict regions to pine forests, it was concluded that A=0.95 t·ha(-1)·yr(-1) (class 2) or A=9.8 t·ha(-1)·yr(-1) (class 3), which correspond to drops of 86% and 54% in soil loss relative to the actual values. Copyright © 2014 Elsevier B.V. All rights reserved.

Evaluation of Long-Range Lightning Detection Networks Using TRMM/LIS Observations

NASA Technical Reports Server (NTRS)

Rudlosky, Scott D.; Holzworth, Robert H.; Carey, Lawrence D.; Schultz, Chris J.; Bateman, Monte; Cecil, Daniel J.; Cummins, Kenneth L.; Petersen, Walter A.; Blakeslee, Richard J.; Goodman, Steven J.

2011-01-01

Recent advances in long-range lightning detection technologies have improved our understanding of thunderstorm evolution in the data sparse oceanic regions. Although the expansion and improvement of long-range lightning datasets have increased their applicability, these applications (e.g., data assimilation, atmospheric chemistry, and aviation weather hazards) require knowledge of the network detection capabilities. Toward this end, the present study evaluates data from the World Wide Lightning Location Network (WWLLN) using observations from the Lightning Imaging Sensor (LIS) aboard the Tropical Rainfall Measurement Mission (TRMM) satellite. The study documents the WWLLN detection efficiency and location accuracy relative to LIS observations, describes the spatial variability in these performance metrics, and documents the characteristics of LIS flashes that are detected by WWLLN. Improved knowledge of the WWLLN detection capabilities will allow researchers, algorithm developers, and operational users to better prepare for the spatial and temporal coverage of the upcoming GOES-R Geostationary Lightning Mapper (GLM).

Modeling of a latent fault detector in a digital system

NASA Technical Reports Server (NTRS)

Nagel, P. M.

1978-01-01

Methods of modeling the detection time or latency period of a hardware fault in a digital system are proposed that explain how a computer detects faults in a computational mode. The objectives were to study how software reacts to a fault, to account for as many variables as possible affecting detection and to forecast a given program's detecting ability prior to computation. A series of experiments were conducted on a small emulated microprocessor with fault injection capability. Results indicate that the detecting capability of a program largely depends on the instruction subset used during computation and the frequency of its use and has little direct dependence on such variables as fault mode, number set, degree of branching and program length. A model is discussed which employs an analog with balls in an urn to explain the rate of which subsequent repetitions of an instruction or instruction set detect a given fault.

Software-implemented fault insertion: An FTMP example

NASA Technical Reports Server (NTRS)

Czeck, Edward W.; Siewiorek, Daniel P.; Segall, Zary Z.

1987-01-01

This report presents a model for fault insertion through software; describes its implementation on a fault-tolerant computer, FTMP; presents a summary of fault detection, identification, and reconfiguration data collected with software-implemented fault insertion; and compares the results to hardware fault insertion data. Experimental results show detection time to be a function of time of insertion and system workload. For the fault detection time, there is no correlation between software-inserted faults and hardware-inserted faults; this is because hardware-inserted faults must manifest as errors before detection, whereas software-inserted faults immediately exercise the error detection mechanisms. In summary, the software-implemented fault insertion is able to be used as an evaluation technique for the fault-handling capabilities of a system in fault detection, identification and recovery. Although the software-inserted faults do not map directly to hardware-inserted faults, experiments show software-implemented fault insertion is capable of emulating hardware fault insertion, with greater ease and automation.

Acoustic thermometry for detecting quenches in superconducting coils and conductor stacks

NASA Astrophysics Data System (ADS)

Marchevsky, M.; Gourlay, S. A.

2017-01-01

Quench detection capability is essential for reliable operation and protection of superconducting magnets, coils, cables, and machinery. We propose a quench detection technique based on sensing local temperature variations in the bulk of a superconducting winding by monitoring its transient acoustic response. Our approach is primarily aimed at coils and devices built with high-temperature superconductor materials where quench detection using standard voltage-based techniques may be inefficient due to the slow velocity of quench propagation. The acoustic sensing technique is non-invasive, fast, and capable of detecting temperature variations of less than 1 K in the interior of the superconductor cable stack in a 77 K cryogenic environment. We show results of finite element modeling and experiments conducted on a model superconductor stack demonstrating viability of the technique for practical quench detection, discuss sensitivity limits of the technique, and its various applications.

Application of a CO2 dial system for infrared detection of forest fire and reduction of false alarm

NASA Astrophysics Data System (ADS)

Bellecci, C.; Francucci, M.; Gaudio, P.; Gelfusa, M.; Martellucci, S.; Richetta, M.; Lo Feudo, T.

2007-04-01

Forest fires can be the cause of serious environmental and economic damages. For this reason considerable effort has been directed toward forest protection and fire fighting. The means traditionally used for early fire detection mainly consist in human observers dispersed over forest regions. A significant improvement in early warning capabilities could be obtained by using automatic detection apparatus. In order to early detect small forest fires and minimize false alarms, the use of a lidar system and dial technique will be considered. A first evaluation of the lowest detectable concentration will be estimated by numerical simulation. The theoretical model will also be used to get the capability of the dial system to control wooded areas. Fixing the burning rate for several fuels, the maximum range of detection will be evaluated. Finally results of simulations will be reported.

Accuracy of self-report in detecting taste dysfunction.

PubMed

Soter, Ana; Kim, John; Jackman, Alexis; Tourbier, Isabelle; Kaul, Arti; Doty, Richard L

2008-04-01

To determine the sensitivity, specificity, and positive and negative predictive value of responses to the following questionnaire statements in detecting taste loss: "I can detect salt in chips, pretzels, or salted nuts," "I can detect sourness in vinegar, pickles, or lemon," "I can detect sweetness in soda, cookies, or ice cream," and "I can detect bitterness, in coffee, beer, or tonic water." Responses to an additional item, "I can detect chocolate in cocoa, cake or candy," was examined to determine whether patients clearly differentiate between taste loss and flavor loss secondary to olfactory dysfunction. A total of 469 patients (207 men, mean age = 54 years, standard deviation = 15 years; and 262 women, mean age = 54 years, standard deviation = 14 years) were administered a questionnaire containing these questions with the response categories of "easily," "somewhat," and "not at all," followed by a comprehensive taste and smell test battery. The questionnaire items poorly detected bona fide taste problems. However, they were sensitive in detecting persons without such problems (i.e., they exhibited low positive but high negative predictive value). Dysfunction categories of the University of Pennsylvania Smell Identification Test (UPSIT) were not meaningfully related to subjects' responses to the questionnaire statements. Both sex and age influenced performance on most of the taste tests, with older persons performing more poorly than younger ones and women typically outperforming men. Although it is commonly assumed that straight-forward questions concerning taste may be useful in detecting taste disorders, this study suggests this is not the case. However, patients who specifically report having no problems with taste perception usually do not exhibit taste dysfunction. The difficulty in detecting true taste problems by focused questionnaire items likely reflects a combination of factors. These include the relatively low prevalence of taste deficits in the general population and the tendency of patients to confuse loss of olfaction-related flavor sensations with taste-bud mediated deficits.

High-sensitivity O-glycomic analysis of mice deficient in core 2 β1,6-N-acetylglucosaminyltransferases

PubMed Central

Ismail, Mohd Nazri; Stone, Erica L; Panico, Maria; Lee, Seung Ho; Luu, Ying; Ramirez, Kevin; Ho, Samuel B; Fukuda, Minoru; Marth, Jamey D; Haslam, Stuart M; Dell, Anne

2011-01-01

Core 2 β1,6-N-acetylglucosaminyltransferase (C2GnT), which exists in three isoforms, C2GnT1, C2GnT2 and C2GnT3, is one of the key enzymes in the O-glycan biosynthetic pathway. These isoenzymes produce core 2 O-glycans and have been correlated with the biosynthesis of core 4 O-glycans and I-branches. Previously, we have reported mice with single and multiple deficiencies of C2GnT isoenzyme(s) and have evaluated the biological and structural consequences of the loss of core 2 function. We now present more comprehensive O-glycomic analyses of neutral and sialylated glycans expressed in the colon, small intestine, stomach, kidney, thyroid/trachea and thymus of wild-type, C2GnT2 and C2GnT3 single knockouts and the C2GnT1–3 triple knockout mice. Very high-quality data have emerged from our mass spectrometry techniques with the capability of detecting O-glycans up to at least 3500 Da. We were able to unambiguously elucidate the types of O-glycan core, branching location and residue linkages, which allowed us to exhaustively characterize structural changes in the knockout tissues. The C2GnT2 knockout mice suffered a major loss of core 2 O-glycans as well as glycans with I-branches on core 1 antennae especially in the stomach and the colon. In contrast, core 2 O-glycans still dominated the O-glycomic profile of most tissues in the C2GnT3 knockout mice. Analysis of the C2GnT triple knockout mice revealed a complete loss of both core 2 O-glycans and branched core 1 antennae, confirming that the three known isoenzymes are entirely responsible for producing these structures. Unexpectedly, O-linked mannosyl glycans are upregulated in the triple deficient stomach. In addition, our studies have revealed an interesting terminal structure detected on O-glycans of the colon tissues that is similar to the RM2 antigen from glycolipids. PMID:20855471

Attribution of irreversible loss to anthropogenic climate change

NASA Astrophysics Data System (ADS)

Huggel, Christian; Bresch, David; Hansen, Gerrit; James, Rachel; Mechler, Reinhard; Stone, Dáithí; Wallimann-Helmer, Ivo

2016-04-01

The Paris Agreement (2015) under the UNFCCC has anchored loss and damage in a separate article which specifies that understanding and support should be enhanced in areas addressing loss and damage such as early warning, preparedness, insurance and resilience. Irreversible loss is a special category under loss and damage but there is still missing clarity over what irreversible loss actually includes. Many negative impacts of climate change may be handled or mitigated by existing risk management, reduction and absorption approaches. Irreversible loss, however, is thought to be insufficiently addressed by risk management. Therefore, countries potentially or actually affected by irreversible loss are calling for other measures such as compensation, which however is highly contested in international climate policy. In Paris (2015) a decision was adopted that loss and damage as defined in the respective article of the agreement does not involve compensation and liability. Nevertheless, it is likely that some sort of mechanism will eventually need to come into play for irreversible loss due to anthropogenic climate change, which might involve compensation, other forms of non-monetary reparation, or transformation. Furthermore, climate litigation has increasingly been attempted to address negative effects of climate change. In this context, attribution is important to understand the drivers of change, what counts as irreversible loss due to climate change, and, possibly, who or what is responsible. Here we approach this issue by applying a detection and attribution perspective on irreversible loss. We first analyze detected climate change impacts as assessed in the IPCC Fifth Assessment Report. We distinguish between irreversible loss in physical, biological and human systems, and accordingly identify the following candidates of irreversible loss in these systems: loss of glaciers and ice sheets, loss of subsurface ice (permafrost) and related loss of lake systems; loss of land area due to coastal and hillslope erosion and sea level change; loss of plant and animal species, loss of ecosystems and biodiversity; loss of human lives, homelands, and cultural identity. Attribution to anthropogenic climate change is analyzed based on recent progress following from the IPCC AR5. Generally, high confidence in attributing irreversible loss to anthropogenic climate change is found in physical systems and more specifically in cryosphere environments, both in mountain and polar regions. Detected loss in terrestrial ecosystems has typically low confidence in attribution whereas loss in some ocean ecosystems (corals) has high confidence. Impacts in human systems that may be classified as irreversible loss are of low confidence in terms of attribution except for the Arctic where higher confidence for a relation with anthropogenic emissions was found. Our analysis suggests that scientific progress in detection and attribution is now at a level that would likely allow policy, or courts, to define mechanisms, or take decisions, as related to irreversible loss in many cryosphere systems. On the other hand, policy may need to consider that at least in the near future it will be difficult to establish clear tracks between irreversible loss in most human systems and anthropogenic climate change, a domain, which however is at the forefront of discussions. We end our discussion with setting out ideas for further clarification of different categories of irreversible loss, including in human systems, and the role of attribution in any policy or legal mechanism in order to help in the development of just and sensible solutions.

Deep Learning for Extreme Weather Detection

NASA Astrophysics Data System (ADS)

Prabhat, M.; Racah, E.; Biard, J.; Liu, Y.; Mudigonda, M.; Kashinath, K.; Beckham, C.; Maharaj, T.; Kahou, S.; Pal, C.; O'Brien, T. A.; Wehner, M. F.; Kunkel, K.; Collins, W. D.

2017-12-01

We will present our latest results from the application of Deep Learning methods for detecting, localizing and segmenting extreme weather patterns in climate data. We have successfully applied supervised convolutional architectures for the binary classification tasks of detecting tropical cyclones and atmospheric rivers in centered, cropped patches. We have subsequently extended our architecture to a semi-supervised formulation, which is capable of learning a unified representation of multiple weather patterns, predicting bounding boxes and object categories, and has the capability to detect novel patterns (w/ few, or no labels). We will briefly present our efforts in scaling the semi-supervised architecture to 9600 nodes of the Cori supercomputer, obtaining 15PF performance. Time permitting, we will highlight our efforts in pixel-level segmentation of weather patterns.

Benefits and Challenges of Architecture Frameworks

DTIC Science & Technology

2011-06-01

systems and identify emerging and obsolete standards. • The NATO Capability View ( NCV ) serves the analysis and optimization of military ca- pabilities... NCVs show the dependencies between different capabilities and allow detecting gaps and overlaps of capabilities. NCVs deliver indirectly requirements...Email (possibly with vendor-specific extensions/modifications) • Proprietary, and possibly not well-documented, message formats • Web services

Concept of electro-optical sensor module for sniper detection system

NASA Astrophysics Data System (ADS)

Trzaskawka, Piotr; Dulski, Rafal; Kastek, Mariusz

2010-10-01

The paper presents an initial concept of the electro-optical sensor unit for sniper detection purposes. This unit, comprising of thermal and daylight cameras, can operate as a standalone device but its primary application is a multi-sensor sniper and shot detection system. Being a part of a larger system it should contribute to greater overall system efficiency and lower false alarm rate thanks to data and sensor fusion techniques. Additionally, it is expected to provide some pre-shot detection capabilities. Generally acoustic (or radar) systems used for shot detection offer only "after-the-shot" information and they cannot prevent enemy attack, which in case of a skilled sniper opponent usually means trouble. The passive imaging sensors presented in this paper, together with active systems detecting pointed optics, are capable of detecting specific shooter signatures or at least the presence of suspected objects in the vicinity. The proposed sensor unit use thermal camera as a primary sniper and shot detection tool. The basic camera parameters such as focal plane array size and type, focal length and aperture were chosen on the basis of assumed tactical characteristics of the system (mainly detection range) and current technology level. In order to provide costeffective solution the commercially available daylight camera modules and infrared focal plane arrays were tested, including fast cooled infrared array modules capable of 1000 fps image acquisition rate. The daylight camera operates as a support, providing corresponding visual image, easier to comprehend for a human operator. The initial assumptions concerning sensor operation were verified during laboratory and field test and some example shot recording sequences are presented.

A correlational approach to predicting operator status

NASA Technical Reports Server (NTRS)

Shingledecker, Clark A.

1988-01-01

This paper discusses a research approach for identifying and validating candidate physiological and behavioral parameters which can be used to predict the performance capabilities of aircrew and other system operators. In this methodology, concurrent and advance correlations are computed between predictor values and criterion performance measures. Continuous performance and sleep loss are used as stressors to promote performance variation. Preliminary data are presented which suggest dependence of prediction capability on the resource allocation policy of the operator.

Air Force is Developing Risk-Mitigation Strategies to Manage Potential Loss of the RD-180 Engine (REDACTED)

DTIC Science & Technology

2015-03-05

launched on its rocket- estimated completion date of May 2015. Air Force will require verification that SpaceX can meet payload integration...design and accelerate integration capability at Space Exploration Technologies Corporation ( SpaceX )1 launch sites. o The Air Force does not intend to...accelerate integration capabilities at SpaceX launch sites because of the studies it directed, but will require verification that SpaceX can meet

Brucella

USDA-ARS?s Scientific Manuscript database

Brucella are intracellular pathogens that cause reproductive losses in animals and zoonotic infections in people. Although named by preferred host species, members of the Brucella genus are capable of infecting multiple species. In preferred hosts, clinical symptoms are generally minimal whereas m...

Supercontinuum Fourier transform spectrometry with balanced detection on a single photodiode

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

Goncharov, Vasily; Hall, Gregory

Here, we have developed phase-sensitive signal detection and processing algorithms for Fourier transform spectrometers fitted with supercontinuum sources for applications requiring ultimate sensitivity. Similar to well-established approach of source noise cancellation through balanced detection of monochromatic light, our method is capable of reducing the relative intensity noise of polychromatic light by 40 dB. Unlike conventional balanced detection, which relies on differential absorption measured with a well matched pair of photo-detectors, our algorithm utilizes phase-sensitive differential detection on a single photodiode and is capable of the real-time correction for instabilities in supercontinuum spectral structure over a broad range of wavelengths. Inmore » the resulting method is universal in terms of applicable wavelengths and compatible with commercial spectrometers. We present a proof-of-principle experimental« less

Supercontinuum Fourier transform spectrometry with balanced detection on a single photodiode

DOE PAGES

Goncharov, Vasily; Hall, Gregory

2016-08-25

Here, we have developed phase-sensitive signal detection and processing algorithms for Fourier transform spectrometers fitted with supercontinuum sources for applications requiring ultimate sensitivity. Similar to well-established approach of source noise cancellation through balanced detection of monochromatic light, our method is capable of reducing the relative intensity noise of polychromatic light by 40 dB. Unlike conventional balanced detection, which relies on differential absorption measured with a well matched pair of photo-detectors, our algorithm utilizes phase-sensitive differential detection on a single photodiode and is capable of the real-time correction for instabilities in supercontinuum spectral structure over a broad range of wavelengths. Inmore » the resulting method is universal in terms of applicable wavelengths and compatible with commercial spectrometers. We present a proof-of-principle experimental« less

Nutrition and muscle loss in humans during spaceflight

NASA Technical Reports Server (NTRS)

Stein, T. P.

1999-01-01

The protein loss in humans during spaceflight is partly due to a normal adaptive response to a decreased work load on the muscles involved in weight bearing. The process is mediated by changes in prostaglandin release, secondary to the decrease in tension on the affected muscles. On missions, where there is a high level of physical demands on the astronauts, there tends to be an energy deficit, which adds to the muscle protein loss and depletes the body fat reserves. While the adaptive response is a normal part of homeostasis, the additional protein loss from an energy deficit can, in the long run, have a negative effect on health and capability of humans to live and work in space and afterward return to Earth.

Predicting concentrations of trace organic compounds in municipal wastewater treatment plant sludge and biosolids using the PhATE™ model.

PubMed

Cunningham, Virginia L; D'Aco, Vincent J; Pfeiffer, Danielle; Anderson, Paul D; Buzby, Mary E; Hannah, Robert E; Jahnke, James; Parke, Neil J

2012-07-01

This article presents the capability expansion of the PhATE™ (pharmaceutical assessment and transport evaluation) model to predict concentrations of trace organics in sludges and biosolids from municipal wastewater treatment plants (WWTPs). PhATE was originally developed as an empirical model to estimate potential concentrations of active pharmaceutical ingredients (APIs) in US surface and drinking waters that could result from patient use of medicines. However, many compounds, including pharmaceuticals, are not completely transformed in WWTPs and remain in biosolids that may be applied to land as a soil amendment. This practice leads to concerns about potential exposures of people who may come into contact with amended soils and also about potential effects to plants and animals living in or contacting such soils. The model estimates the mass of API in WWTP influent based on the population served, the API per capita use, and the potential loss of the compound associated with human use (e.g., metabolism). The mass of API on the treated biosolids is then estimated based on partitioning to primary and secondary solids, potential loss due to biodegradation in secondary treatment (e.g., activated sludge), and potential loss during sludge treatment (e.g., aerobic digestion, anaerobic digestion, composting). Simulations using 2 surrogate compounds show that predicted environmental concentrations (PECs) generated by PhATE are in very good agreement with measured concentrations, i.e., well within 1 order of magnitude. Model simulations were then carried out for 18 APIs representing a broad range of chemical and use characteristics. These simulations yielded 4 categories of results: 1) PECs are in good agreement with measured data for 9 compounds with high analytical detection frequencies, 2) PECs are greater than measured data for 3 compounds with high analytical detection frequencies, possibly as a result of as yet unidentified depletion mechanisms, 3) PECs are less than analytical reporting limits for 5 compounds with low analytical detection frequencies, and 4) the PEC is greater than the analytical method reporting limit for 1 compound with a low analytical detection frequency, possibly again as a result of insufficient depletion data. Overall, these results demonstrate that PhATE has the potential to be a very useful tool in the evaluation of APIs in biosolids. Possible applications include: prioritizing APIs for assessment even in the absence of analytical methods; evaluating sludge processing scenarios to explore potential mitigation approaches; using in risk assessments; and developing realistic nationwide concentrations, because PECs can be represented as a cumulative probability distribution. Finally, comparison of PECs to measured concentrations can also be used to identify the need for fate studies of compounds of interest in biosolids. Copyright © 2011 SETAC.

Detection of Unilateral Hearing Loss by Stationary Wavelet Entropy.

PubMed

Zhang, Yudong; Nayak, Deepak Ranjan; Yang, Ming; Yuan, Ti-Fei; Liu, Bin; Lu, Huimin; Wang, Shuihua

2017-01-01

Sensorineural hearing loss is correlated to massive neurological or psychiatric disease. T1-weighted volumetric images were acquired from fourteen subjects with right-sided hearing loss (RHL), fifteen subjects with left-sided hearing loss (LHL), and twenty healthy controls (HC). We treated a three-class classification problem: HC, LHL, and RHL. Stationary wavelet entropy was employed to extract global features from magnetic resonance images of each subject. Those stationary wavelet entropy features were used as input to a single-hidden layer feedforward neuralnetwork classifier. The 10 repetition results of 10-fold cross validation show that the accuracies of HC, LHL, and RHL are 96.94%, 97.14%, and 97.35%, respectively. Our developed system is promising and effective in detecting hearing loss. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Advancing Explosives Detection Capabilities: Vapor Detection

ScienceCinema

Atkinson, David

2018-05-11

A new, PNNL-developed method provides direct, real-time detection of trace amounts of explosives such as RDX, PETN and C-4. The method selectively ionizes a sample before passing the sample through a mass spectrometer to detect explosive vapors. The method could be used at airports to improve aviation security.

40 CFR 264.1101 - Design and operating standards.

Code of Federal Regulations, 2010 CFR

2010-07-01

... hazardous waste (e.g., upon detection of leakage from the primary barrier) the owner or operator must: (A... constituents into the barrier, and a leak detection system that is capable of detecting failure of the primary... requirements of the leak detection component of the secondary containment system are satisfied by installation...

Advancing Explosives Detection Capabilities: Vapor Detection

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

Atkinson, David

2012-10-15

A new, PNNL-developed method provides direct, real-time detection of trace amounts of explosives such as RDX, PETN and C-4. The method selectively ionizes a sample before passing the sample through a mass spectrometer to detect explosive vapors. The method could be used at airports to improve aviation security.

Loss of heterozygosity assay for molecular detection of cancer using energy-transfer primers and capillary array electrophoresis.

PubMed

Medintz, I L; Lee, C C; Wong, W W; Pirkola, K; Sidransky, D; Mathies, R A

2000-08-01

Microsatellite DNA loci are useful markers for the detection of loss of heterozygosity (LOH) and microsatellite instability (MI) associated with primary cancers. To carry out large-scale studies of LOH and MI in cancer progression, high-throughput instrumentation and assays with high accuracy and sensitivity need to be validated. DNA was extracted from 26 renal tumor and paired lymphocyte samples and amplified with two-color energy-transfer (ET) fluorescent primers specific for loci associated with cancer-induced chromosomal changes. PCR amplicons were separated on the MegaBACE-1000 96 capillary array electrophoresis (CAE) instrument and analyzed with MegaBACE Genetic Profiler v.1.0 software. Ninety-six separations were achieved in parallel in 75 minutes. Loss of heterozygosity was easily detected in tumor samples as was the gain/loss of microsatellite core repeats. Allelic ratios were determined with a precision of +/- 10% or better. Prior analysis of these samples with slab gel electrophoresis and radioisotope labeling had not detected these changes with as much sensitivity or precision. This study establishes the validity of this assay and the MegaBACE instrument for large-scale, high-throughput studies of the molecular genetic changes associated with cancer.

New method to determine the total carbonyl functional group content in extractable particulate organic matter by tandem mass spectrometry.

PubMed

Dron, J; Zheng, W; Marchand, N; Wortham, H

2008-08-01

A functional group analysis method was developed to determine the quantitative content of carbonyl functional groups in atmospheric particulate organic matter (POM) using constant neutral loss scanning-tandem mass spectrometry (CNLS-MS/MS). The neutral loss method consists in monitoring the loss of a neutral fragment produced by the fragmentation of a precursor ion in a collision cell. The only ions detected are the daughter ions resulting from the loss of the neutral fragment under study. Then, scanning the loss of a neutral fragment characteristic of a functional group enables the selective detection of the compounds bearing the chemical function under study within a complex mixture. The selective detection of carbonyl functional groups was achieved after derivatization with pentafluorophenylhydrazine (PFPH) by monitoring the neutral loss of C(6)F(5)N (181 amu), which was characteristic of a large panel of derivatized carbonyl compounds. The method was tested on 25 reference mixtures of different composition, all containing 24 carbonyl compounds at randomly determined concentrations. The repeatability and calibration tests were satisfying as they resulted in a relative standard deviation below 5% and a linear range between 0.01 and 0.65 mM with a calculated detection limit of 0.0035 mM. Also, the relative deviation induced by changing the composition of the mixture while keeping the total concentration of carbonyl functional groups constant was less than 20%. These reliability experiments demonstrate the high robustness of the developed procedure for accurate carbonyl functional group measurement, which was applied to atmospheric POM samples. Copyright (c) 2008 John Wiley & Sons, Ltd.

Positive and relaxed selection associated with flight evolution and loss in insect transcriptomes

PubMed Central

Mitterboeck, T. Fatima; Liu, Shanlin; Adamowicz, Sarah J.; Fu, Jinzhong; Zhang, Rui; Song, Wenhui; Meusemann, Karen

2017-01-01

Abstract The evolution of powered flight is a major innovation that has facilitated the success of insects. Previously, studies of birds, bats, and insects have detected molecular signatures of differing selection regimes in energy-related genes associated with flight evolution and/or loss. Here, using DNA sequences from more than 1000 nuclear and mitochondrial protein-coding genes obtained from insect transcriptomes, we conduct a broader exploration of which gene categories display positive and relaxed selection at the origin of flight as well as with multiple independent losses of flight. We detected a number of categories of nuclear genes more often under positive selection in the lineage leading to the winged insects (Pterygota), related to catabolic processes such as proteases, as well as splicing-related genes. Flight loss was associated with relaxed selection signatures in splicing genes, mirroring the results for flight evolution. Similar to previous studies of flight loss in various animal taxa, we observed consistently higher nonsynonymous-to-synonymous substitution ratios in mitochondrial genes of flightless lineages, indicative of relaxed selection in energy-related genes. While oxidative phosphorylation genes were not detected as being under selection with the origin of flight specifically, they were most often detected as being under positive selection in holometabolous (complete metamorphosis) insects as compared with other insect lineages. This study supports some convergence in gene-specific selection pressures associated with flight ability, and the exploratory analysis provided some new insights into gene categories potentially associated with the gain and loss of flight in insects. PMID:29020740

Positive and relaxed selection associated with flight evolution and loss in insect transcriptomes.

PubMed

Mitterboeck, T Fatima; Liu, Shanlin; Adamowicz, Sarah J; Fu, Jinzhong; Zhang, Rui; Song, Wenhui; Meusemann, Karen; Zhou, Xin

2017-10-01

The evolution of powered flight is a major innovation that has facilitated the success of insects. Previously, studies of birds, bats, and insects have detected molecular signatures of differing selection regimes in energy-related genes associated with flight evolution and/or loss. Here, using DNA sequences from more than 1000 nuclear and mitochondrial protein-coding genes obtained from insect transcriptomes, we conduct a broader exploration of which gene categories display positive and relaxed selection at the origin of flight as well as with multiple independent losses of flight. We detected a number of categories of nuclear genes more often under positive selection in the lineage leading to the winged insects (Pterygota), related to catabolic processes such as proteases, as well as splicing-related genes. Flight loss was associated with relaxed selection signatures in splicing genes, mirroring the results for flight evolution. Similar to previous studies of flight loss in various animal taxa, we observed consistently higher nonsynonymous-to-synonymous substitution ratios in mitochondrial genes of flightless lineages, indicative of relaxed selection in energy-related genes. While oxidative phosphorylation genes were not detected as being under selection with the origin of flight specifically, they were most often detected as being under positive selection in holometabolous (complete metamorphosis) insects as compared with other insect lineages. This study supports some convergence in gene-specific selection pressures associated with flight ability, and the exploratory analysis provided some new insights into gene categories potentially associated with the gain and loss of flight in insects. © The Authors 2017. Published by Oxford University Press.

Research on capability of detecting ballistic missile by near space infrared system

NASA Astrophysics Data System (ADS)

Lu, Li; Sheng, Wen; Jiang, Wei; Jiang, Feng

2018-01-01

The infrared detection technology of ballistic missile based on near space platform can effectively make up the shortcomings of high-cost of traditional early warning satellites and the limited earth curvature of ground-based early warning radar. In terms of target detection capability, aiming at the problem that the formula of the action distance based on contrast performance ignores the background emissivity in the calculation process and the formula is only valid for the monochromatic light, an improved formula of the detecting range based on contrast performance is proposed. The near space infrared imaging system parameters are introduced, the expression of the contrastive action distance formula based on the target detection of the near space platform is deduced. The detection range of the near space infrared system for the booster stage ballistic missile skin, the tail nozzle and the tail flame is calculated. The simulation results show that the near-space infrared system has the best effect on the detection of tail-flame radiation.

CTBT infrasound network performance to detect the 2013 Russian fireball event

DOE PAGES

Pilger, Christoph; Ceranna, Lars; Ross, J. Ole; ...

2015-03-18

The explosive fragmentation of the 2013 Chelyabinsk meteorite generated a large airburst with an equivalent yield of 500 kT TNT. It is the most energetic event recorded by the infrasound component of the Comprehensive Nuclear-Test-Ban Treaty-International Monitoring System (CTBT-IMS), globally detected by 20 out of 42 operational stations. This study performs a station-by-station estimation of the IMS detection capability to explain infrasound detections and nondetections from short to long distances, using the Chelyabinsk meteorite as global reference event. Investigated parameters influencing the detection capability are the directivity of the line source signal, the ducting of acoustic energy, and the individualmore » noise conditions at each station. Findings include a clear detection preference for stations perpendicular to the meteorite trajectory, even over large distances. Only a weak influence of stratospheric ducting is observed for this low-frequency case. As a result, a strong dependence on the diurnal variability of background noise levels at each station is observed, favoring nocturnal detections.« less

Moving beyond the function of the health behaviour: the effect of message frame on behavioural decision-making.

PubMed

Bartels, Roger D; Kelly, Kristina M; Rothman, Alexander J

2010-09-01

Health messages that provide gain- or loss-framed arguments have a differential impact on behavioural decision-making (Rothman & Salovey, 1997). Typically, gain-framed messages more effectively promote preventive health behaviours, which maintain health and minimise the risk of a health problem, whereas loss-framed messages more effectively promote detection behaviours, which involve the risk of finding a health problem. Two experiments tested the thesis that the risk implications of the behaviour are an important determinant of the persuasive impact of gain- and loss-framed appeals. Results revealed that when the risk associated with a health behaviour (either a prevention behaviour in Experiment 1 or a detection behaviour in Experiment 2) was low, participants responded more favourably to gain-framed messages. However, when the risk associated with the health behaviour (either prevention or detection) was high, participants responded more favourably to loss-framed messages. Discussion focuses on the importance of taking into account how individuals construe a behaviour when constructing framed appeals.

Development of an imaging system for the detection of alumina on turbine blades

NASA Astrophysics Data System (ADS)

Greenwell, S. J.; Kell, J.; Day, J. C. C.

2014-03-01

An imaging system capable of detecting alumina on turbine blades by acquiring LED-induced fluorescence images has been developed. Acquiring fluorescence images at adjacent spectral bands allows the system to distinguish alumina from fluorescent surface contaminants. Repair and overhaul processes require that alumina is entirely removed from the blades by grit blasting and chemical stripping. The capability of the system to detect alumina has been investigated with two series of turbine blades provided by Rolls-Royce plc. The results illustrate that the system provides a superior inspection method to visual assessment when ascertaining whether alumina is present on turbine blades during repair and overhaul processes.

Oil pollution signatures by remote sensing.

NASA Technical Reports Server (NTRS)

Catoe, C. E.; Mclean, J. T.

1972-01-01

Study of the possibility of developing an effective remote sensing system for oil pollution monitoring which would be capable of detecting oil films on water, mapping the areal extent of oil slicks, measuring slick thickness, and identifying the oil types. In the spectral regions considered (ultraviolet, visible, infrared, microwave, and radar), the signatures were sufficiently unique when compared to the background so that it was possible to detect and map oil slicks. Both microwave and radar techniques are capable of operating in adverse weather. Fluorescence techniques show promise in identifying oil types. A multispectral system will be required to detect oil, map its distribution, estimate film thickness, and characterize the oil pollutant.

Organo luminescent semiconductor nanocrystal probes for biological applications and process for making and using such probes

DOEpatents

Weiss, Shimon; Bruchez, Jr., Marcel; Alivisatos, Paul

2006-09-05

A semiconductor nanocrystal compound is described capable of linking to an affinity molecule. The compound comprises (1) a semiconductor nanocrystal capable of emitting electromagnetic radiation and/or absorbing energy, and/or scattering or diffracting electromagnetic radiation--when excited by an electromagnetic radiation source or a particle beam; and (2) at least one linking agent, having a first portion linked to the semiconductor nanocrystal and a second portion capable of linking to an affinity molecule. The compound is linked to an affinity molecule to form a semiconductor nanocrystal probe capable of bonding with a detectable substance. subsequent exposure to excitation energy will excite the semiconductor nanocrystal in the probe causing the emission of electromagnetic radiation. Further described are processes for respectively: making the luminescent semiconductor nanocrystal compound; making the semiconductor nanocrystal probe; and using the probe to determine the presence of a detectable substance in a material.

Organo luminescent semiconductor nanocrystal probes for biological applications and process for making and using such probes

DOEpatents

Weiss, Shimon [Pinole, CA; Bruchez, Jr., Marcel; Alivisatos, Paul [Oakland, CA

2004-03-02

A semiconductor nanocrystal compound is described capable of linking to an affinity molecule. The compound comprises (1) a semiconductor nanocrystal capable of emitting electromagnetic radiation and/or absorbing energy, and/or scattering or diffracting electromagnetic radiation--when excited by an electromagnetic radiation source or a particle beam; and (2) at least one linking agent, having a first portion linked to the semiconductor nanocrystal and a second portion capable of linking to an affinity molecule. The compound is linked to an affinity molecule to form a semiconductor nanocrystal probe capable of bonding with a detectable substance. Subsequent exposure to excitation energy will excite the semiconductor nanocrystal in the probe, causing the emission of electromagnetic radiation. Further described are processes for respectively: making the semiconductor nanocrystal compound; making the semiconductor nanocrystal probe; and using the probe to determine the presence of a detectable substance in a material.

Organo luminescent semiconductor nanocrystal probes for biological applications and process for making and using such probes

DOEpatents

Weiss, Shimon; Bruchez, Jr., Marcel; Alivisatos, Paul

2005-08-09

A semiconductor nanocrystal compound is described capable of linking to an affinity molecule. The compound comprises (1) a semiconductor nanocrystal capable of emitting electromagnetic radiation and/or absorbing energy, and/or scattering or diffracting electromagnetic radiation--when excited by an electromagnetic radiation source or a particle beam; and (2) at least one linking agent, having a first portion linked to the semiconductor nanocrystal and a second portion capable of linking to an affinity molecule. The compound is linked to an affinity molecule to form a semiconductor nanocrystal probe capable of bonding with a detectable substance. Subsequent exposure to excitation energy will excite the semiconductor nanocrystal in the probe causing the emission of electromagnetic radiation. Further described are processes for respectively: making the luminescent semiconductor nanocrystal compound; making the semiconductor nanocrystal probe; and using the probe to determine the presence of a detectable substance in a material.

Organo luminescent semiconductor nanocrystal probes for biological applications and process for making and using such probes

DOEpatents

Weiss, Shimon; Bruchez, Jr., Marcel; Alivisatos, Paul

2002-01-01

A semiconductor nanocrystal compound is described capable of linking to an affinity molecule. The compound comprises (1) a semiconductor nanocrystal capable of emitting electromagnetic radiation and/or absorbing energy, and/or scattering or diffracting electromagnetic radiation--when excited by an electromagnetic radiation source or a particle beam; and (2) at least one linking agent, having a first portion linked to the semiconductor nanocrystal and a second portion capable of linking to an affity molecule. The compound is linked to an affinity molecule to form a semiconductor nanocrystal probe capable of bonding with a detectable substance. Subsequent exposure to excitation energy will excite the semiconductor nanocrystal in he probe, causing the emission of electromagnetic radiation. Further described are processes for respectively: making the semiconductor nanocrystal compound; making the semiconductor nanocrystal probe; and using the probe to determine the presence of a detectable substance in a material.

In vivo MR detection of fluorine-labeled human MSC using the bSSFP sequence

PubMed Central

Ribot, Emeline J; Gaudet, Jeffrey M; Chen, Yuhua; Gilbert, Kyle M; Foster, Paula J

2014-01-01

Mesenchymal stem cells (MSC) are used to restore deteriorated cell environments. There is a need to specifically track these cells following transplantation in order to evaluate different methods of implantation, to follow their migration within the body, and to quantify their accumulation at the target. Cellular magnetic resonance imaging (MRI) using fluorine-based nanoemulsions is a great means to detect these transplanted cells in vivo because of the high specificity for fluorine detection and the capability for precise quantification. This technique, however, has low sensitivity, necessitating improvement in MR sequences. To counteract this issue, the balanced steady-state free precession (bSSFP) imaging sequence can be of great interest due to the high signal-to-noise ratio (SNR). Furthermore, it can be applied to obtain 3D images within short acquisition times. In this paper, bSSFP provided accurate quantification of samples of the perfluorocarbon Cell Sense-labeled cells in vitro. Cell Sense was internalized by human MSC (hMSC) without adverse alterations in cell viability or differentiation into adipocytes/osteocytes. The bSSFP sequence was applied in vivo to track and quantify the signals from both Cell Sense-labeled and iron-labeled hMSC after intramuscular implantation. The fluorine signal was observed to decrease faster and more significantly than the volume of iron-associated voids, which points to the advantage of quantifying the fluorine signal and the complexity of quantifying signal loss due to iron. PMID:24748787

In vivo MR detection of fluorine-labeled human MSC using the bSSFP sequence.

PubMed

Ribot, Emeline J; Gaudet, Jeffrey M; Chen, Yuhua; Gilbert, Kyle M; Foster, Paula J

2014-01-01

Mesenchymal stem cells (MSC) are used to restore deteriorated cell environments. There is a need to specifically track these cells following transplantation in order to evaluate different methods of implantation, to follow their migration within the body, and to quantify their accumulation at the target. Cellular magnetic resonance imaging (MRI) using fluorine-based nanoemulsions is a great means to detect these transplanted cells in vivo because of the high specificity for fluorine detection and the capability for precise quantification. This technique, however, has low sensitivity, necessitating improvement in MR sequences. To counteract this issue, the balanced steady-state free precession (bSSFP) imaging sequence can be of great interest due to the high signal-to-noise ratio (SNR). Furthermore, it can be applied to obtain 3D images within short acquisition times. In this paper, bSSFP provided accurate quantification of samples of the perfluorocarbon Cell Sense-labeled cells in vitro. Cell Sense was internalized by human MSC (hMSC) without adverse alterations in cell viability or differentiation into adipocytes/osteocytes. The bSSFP sequence was applied in vivo to track and quantify the signals from both Cell Sense-labeled and iron-labeled hMSC after intramuscular implantation. The fluorine signal was observed to decrease faster and more significantly than the volume of iron-associated voids, which points to the advantage of quantifying the fluorine signal and the complexity of quantifying signal loss due to iron.

Chemiluminescence-based pesticide biosensor utilizing the intelligent evolved properties of the enzyme alkaline phosphatase

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

Ayyagari, M.; Kamtekar, S.; Pande, R.

A methodology is described for immobilizing the enzyme alkaline phosphatase onto a glass surface using a novel biotinylated copolymer, poly(3-undecylthiophene-co-3- methanoithiophene). A streptavidin conjugate of alkaline phosphatase is used in this study. The biotinylated polymer is attached to the silanized glass surface via hydrophobic interactions and the enzyme is interfaced with the polymer through the classical biotin- streptavidin interaction. Alkaline phosphatase catalyzes the dephosphorylation of a macrocyclic compound, chloro-3-(4-methoxy spiro) (1,2 dioxetane-3-2`-tricyclo-) (3.3.1.1 )-(decani-4-yl) phenyl phosphate, to a species which emits energy by chemiluminescence. This chemiluminescence signal can be detected with a photomultiplier tube for enzymatic catalysis with the biocatalystmore » both in solution and immobilized on a glass surface. The signal generation is inhibited by the organophosphorus based insecticides such as paraoxon as well as nerve agents. We demonstrate in this study that a number of organophosphorus based insecticides inhibit the enzyme-mediated generation of chemiluminescence signal. This is true for the enzyme conjugate both free in solution and immobilized on a glass surface. In solution, the inhibition resembles the case of a partially uncompetitive system. By this type of inhibition we are able to detect pesticides down to about 50 ppb for the enzyme in solution. The pesticide detection limit of immobilized enzyme is currently being investigated. The enzyme is capable of a number of measurement cycles without significant loss of signal level.« less

Proteomic analyses of host and pathogen responses during bovine mastitis.

PubMed

Boehmer, Jamie L

2011-12-01

The pursuit of biomarkers for use as clinical screening tools, measures for early detection, disease monitoring, and as a means for assessing therapeutic responses has steadily evolved in human and veterinary medicine over the past two decades. Concurrently, advances in mass spectrometry have markedly expanded proteomic capabilities for biomarker discovery. While initial mass spectrometric biomarker discovery endeavors focused primarily on the detection of modulated proteins in human tissues and fluids, recent efforts have shifted to include proteomic analyses of biological samples from food animal species. Mastitis continues to garner attention in veterinary research due mainly to affiliated financial losses and food safety concerns over antimicrobial use, but also because there are only a limited number of efficacious mastitis treatment options. Accordingly, comparative proteomic analyses of bovine milk have emerged in recent years. Efforts to prevent agricultural-related food-borne illness have likewise fueled an interest in the proteomic evaluation of several prominent strains of bacteria, including common mastitis pathogens. The interest in establishing biomarkers of the host and pathogen responses during bovine mastitis stems largely from the need to better characterize mechanisms of the disease, to identify reliable biomarkers for use as measures of early detection and drug efficacy, and to uncover potentially novel targets for the development of alternative therapeutics. The following review focuses primarily on comparative proteomic analyses conducted on healthy versus mastitic bovine milk. However, a comparison of the host defense proteome of human and bovine milk and the proteomic analysis of common veterinary pathogens are likewise introduced.

Detection of BRCA1 gross rearrangements by droplet digital PCR.

PubMed

Preobrazhenskaya, Elena V; Bizin, Ilya V; Kuligina, Ekatherina Sh; Shleykina, Alla Yu; Suspitsin, Evgeny N; Zaytseva, Olga A; Anisimova, Elena I; Laptiev, Sergey A; Gorodnova, Tatiana V; Belyaev, Alexey M; Imyanitov, Evgeny N; Sokolenko, Anna P

2017-10-01

Large genomic rearrangements (LGRs) constitute a significant share of pathogenic BRCA1 mutations. Multiplex ligation-dependent probe amplification (MLPA) is a leading method for LGR detection; however, it is entirely based on the use of commercial kits, includes relatively time-consuming hybridization step, and is not convenient for large-scale screening of recurrent LGRs. We developed and validated the droplet digital PCR (ddPCR) assay, which covers the entire coding region of BRCA1 gene and is capable to precisely quantitate the copy number for each exon. 141 breast cancer (BC) patients, who demonstrated evident clinical features of hereditary BC but turned out to be negative for founder BRCA1/2 mutations, were subjected to the LGR analysis. Four patients with LGR were identified, with three cases of exon 8 deletion and one women carrying the deletion of exons 5-7. Excellent concordance with MLPA test was observed. Exon 8 copy number was tested in additional 720 BC and 184 ovarian cancer (OC) high-risk patients, and another four cases with the deletion were revealed; MLPA re-analysis demonstrated that exon 8 loss was a part of a larger genetic alteration in two cases, while the remaining two patients had isolated defect of exon 8. Long-range PCR and next generation sequencing of DNA samples carrying exon 8 deletion revealed two types of recurrent LGRs. Droplet digital PCR is a reliable tool for the detection of large genomic rearrangements.

A burst-mode photon counting receiver with automatic channel estimation and bit rate detection

NASA Astrophysics Data System (ADS)

Rao, Hemonth G.; DeVoe, Catherine E.; Fletcher, Andrew S.; Gaschits, Igor D.; Hakimi, Farhad; Hamilton, Scott A.; Hardy, Nicholas D.; Ingwersen, John G.; Kaminsky, Richard D.; Moores, John D.; Scheinbart, Marvin S.; Yarnall, Timothy M.

2016-04-01

We demonstrate a multi-rate burst-mode photon-counting receiver for undersea communication at data rates up to 10.416 Mb/s over a 30-foot water channel. To the best of our knowledge, this is the first demonstration of burst-mode photon-counting communication. With added attenuation, the maximum link loss is 97.1 dB at λ=517 nm. In clear ocean water, this equates to link distances up to 148 meters. For λ=470 nm, the achievable link distance in clear ocean water is 450 meters. The receiver incorporates soft-decision forward error correction (FEC) based on a product code of an inner LDPC code and an outer BCH code. The FEC supports multiple code rates to achieve error-free performance. We have selected a burst-mode receiver architecture to provide robust performance with respect to unpredictable channel obstructions. The receiver is capable of on-the-fly data rate detection and adapts to changing levels of signal and background light. The receiver updates its phase alignment and channel estimates every 1.6 ms, allowing for rapid changes in water quality as well as motion between transmitter and receiver. We demonstrate on-the-fly rate detection, channel BER within 0.2 dB of theory across all data rates, and error-free performance within 1.82 dB of soft-decision capacity across all tested code rates. All signal processing is done in FPGAs and runs continuously in real time.

Telemetric real-time sensor for the detection of acute upper gastrointestinal bleeding.

PubMed

Schostek, Sebastian; Zimmermann, Melanie; Keller, Jan; Fode, Mario; Melbert, Michael; Schurr, Marc O; Gottwald, Thomas; Prosst, Ruediger L

2016-04-15

Acute upper gastrointestinal bleedings from ulcers or esophago-gastric varices are life threatening medical conditions which require immediate endoscopic therapy. Despite successful endoscopic hemostasis, there is a significant risk of rebleeding often requiring close surveillance of these patients in the intensive care unit (ICU). Any time delay to recognize bleeding may lead to a high blood loss and increases the risk of death. A novel telemetric real-time bleeding sensor can help indicate blood in the stomach: the sensor is swallowed to detect active bleeding or is anchored endoscopically on the gastrointestinal wall close to the potential bleeding source. By telemetric communication with an extra-corporeal receiver, information about the bleeding status is displayed. In this study the novel sensor, which measures characteristic optical properties of blood, has been evaluated in an ex-vivo setting to assess its clinical applicability and usability. Human venous blood of different concentrations, various fluids, and liquid food were tested. The LED-based sensor was able to reliably distinguish between concentrated blood and other liquids, especially red-colored fluids. In addition, the spectrometric quality of the small sensor (size: 6.5mm in diameter, 25.5mm in length) was comparable to a much larger and technically more complex laboratory spectrophotometer. The experimental data confirm the capability of a miniaturized sensor to identify concentrated blood, which could help in the very near future the detection of upper gastrointestinal bleeding and to survey high-risk patients for rebleeding. Copyright © 2015 Elsevier B.V. All rights reserved.

Measuring mouse retina response near the detection threshold to direct stimulation of photons with sub-poisson statistics

NASA Astrophysics Data System (ADS)

Tavala, Amir; Dovzhik, Krishna; Schicker, Klaus; Koschak, Alexandra; Zeilinger, Anton

Probing the visual system of human and animals at very low photon rate regime has recently attracted the quantum optics community. In an experiment on the isolated photoreceptor cells of Xenopus, the cell output signal was measured while stimulating it by pulses with sub-poisson distributed photons. The results showed single photon detection efficiency of 29 +/-4.7% [1]. Another behavioral experiment on human suggests a less detection capability at perception level with the chance of 0.516 +/-0.01 (i.e. slightly better than random guess) [2]. Although the species are different, both biological models and experimental observations with classical light stimuli expect that a fraction of single photon responses is filtered somewhere within the retina network and/or during the neural processes in the brain. In this ongoing experiment, we look for a quantitative answer to this question by measuring the output signals of the last neural layer of WT mouse retina using microelectrode arrays. We use a heralded downconversion single-photon source. We stimulate the retina directly since the eye lens (responsible for 20-50% of optical loss and scattering [2]) is being removed. Here, we demonstrate our first results that confirms the response to the sub-poisson distributied pulses. This project was supported by Austrian Academy of Sciences, SFB FoQuS F 4007-N23 funded by FWF and ERC QIT4QAD 227844 funded by EU Commission.

Optics-Integrated Microfluidic Platforms for Biomolecular Analyses

PubMed Central

Bates, Kathleen E.; Lu, Hang

2016-01-01

Compared with conventional optical methods, optics implemented on microfluidic chips provide small, and often much cheaper ways to interrogate biological systems from the level of single molecules up to small model organisms. The optical probing of single molecules has been used to investigate the mechanical properties of individual biological molecules; however, multiplexing of these measurements through microfluidics and nanofluidics confers many analytical advantages. Optics-integrated microfluidic systems can significantly simplify sample processing and allow a more user-friendly experience; alignments of on-chip optical components are predetermined during fabrication and many purely optical techniques are passively controlled. Furthermore, sample loss from complicated preparation and fluid transfer steps can be virtually eliminated, a particularly important attribute for biological molecules at very low concentrations. Excellent fluid handling and high surface area/volume ratios also contribute to faster detection times for low abundance molecules in small sample volumes. Although integration of optical systems with classical microfluidic analysis techniques has been limited, microfluidics offers a ready platform for interrogation of biophysical properties. By exploiting the ease with which fluids and particles can be precisely and dynamically controlled in microfluidic devices, optical sensors capable of unique imaging modes, single molecule manipulation, and detection of minute changes in concentration of an analyte are possible. PMID:27119629

Usefulness of Intravital Multiphoton Microscopy in Visualizing Study of Mouse Cochlea and Volume Changes in the Scala Media

PubMed Central

Ju, Hyun Mi; Lee, Sun Hee; Kong, Tae Hoon; Kwon, Seung-Hae; Choi, Jin Sil; Seo, Young Joon

2017-01-01

Conventional microscopy has limitations in viewing the cochlear microstructures due to three-dimensional spiral structure and the overlying bone. But these issues can be overcome by imaging the cochlea in vitro with intravital multiphoton microscopy (MPM). By using near-infrared lasers for multiphoton excitation, intravital MPM can detect endogenous fluorescence and second harmonic generation of tissues. In this study, we used intravital MPM to visualize various cochlear microstructures without any staining and non-invasively analyze the volume changes of the scala media (SM) without removing the overlying cochlear bone. The intravital MPM images revealed various tissue types, ranging from thin membranes to dense bone, as well as the spiral ganglion beneath the cochlear bone. The two-dimensional, cross-sectional, and serial z-stack intravital MPM images also revealed the spatial dilation of the SM in the temporal bone of pendrin-deficient mice. These findings suggest that intravital MPM might serve as a new method for obtaining microanatomical information regarding the cochlea, similar to standard histopathological analyses in the animal study for the cochlea. Given the capability of intravital MPM for detecting an increase in the volume of the SM in pendrin-deficient mice, it might be a promising new tool for assessing the pathophysiology of hearing loss in the future. PMID:28824523

Soft, Transparent, Electronic Skin for Distributed and Multiple Pressure Sensing

PubMed Central

Levi, Alessandro; Piovanelli, Matteo; Furlan, Silvano; Mazzolai, Barbara; Beccai, Lucia

2013-01-01

In this paper we present a new optical, flexible pressure sensor that can be applied as smart skin to a robot or to consumer electronic devices. We describe a mechano-optical transduction principle that can allow the encoding of information related to an externally applied mechanical stimulus, e.g., contact, pressure and shape of contact. The physical embodiment that we present in this work is an electronic skin consisting of eight infrared emitters and eight photo-detectors coupled together and embedded in a planar PDMS waveguide of 5.5 cm diameter. When a contact occurs on the sensing area, the optical signals reaching the peripheral detectors experience a loss because of the Frustrated Total Internal Reflection and deformation of the material. The light signal is converted to electrical signal through an electronic system and a reconstruction algorithm running on a computer reconstructs the pressure map. Pilot experiments are performed to validate the tactile sensing principle by applying external pressures up to 160 kPa. Moreover, the capabilities of the electronic skin to detect contact pressure at multiple subsequent positions, as well as its function on curved surfaces, are validated. A weight sensitivity of 0.193 gr−1 was recorded, thus making the electronic skin suitable to detect pressures in the order of few grams. PMID:23686140

Monitoring and localization of buried plastic natural gas pipes using passive RF tags

NASA Astrophysics Data System (ADS)

Mondal, Saikat; Kumar, Deepak; Ghazali, Mohd. Ifwat; Chahal, Prem; Udpa, Lalita; Deng, Yiming

2018-04-01

A passive harmonic radio frequency (RF) tag on the pipe with added sensing capabilities is proposed in this paper. Radio frequency identification (RFID) based tagging has already emerged as a potential solution for chemical sensing, location detection, animal tagging, etc. Harmonic transponders are already quite popular compared to conventional RFIDs due to their improved signal to noise ratio (SNR). However, the operating frequency, transmitted power and tag efficiency become critical issues for underground RFIDs. In this paper, a comprehensive on-tag sensing, power budget and frequency analyses is performed for buried harmonic tag design. Accurate tracking of infrastructure burial depth is proposed to reduce the probability of failure of underground pipelines. Burial depth is estimated using phase information of received signals at different frequencies calculated using genetic algorithm (GA) based optimization for post processing. Suitable frequency range is determined for a variety of soil with different moisture content for small tag-antenna size. Different types of harmonic tags such as 1) Schottky diode, 2) Non-linear Transmission Line (NLTL) were compared for underground applications. In this study, the power, frequency and tag design have been optimized to achieve small antenna size, minimum signal loss and simple reader circuit for underground detection at up to 5 feet depth in different soil medium and moisture contents.

Usefulness of Intravital Multiphoton Microscopy in Visualizing Study of Mouse Cochlea and Volume Changes in the Scala Media.

PubMed

Ju, Hyun Mi; Lee, Sun Hee; Kong, Tae Hoon; Kwon, Seung-Hae; Choi, Jin Sil; Seo, Young Joon

2017-01-01

Conventional microscopy has limitations in viewing the cochlear microstructures due to three-dimensional spiral structure and the overlying bone. But these issues can be overcome by imaging the cochlea in vitro with intravital multiphoton microscopy (MPM). By using near-infrared lasers for multiphoton excitation, intravital MPM can detect endogenous fluorescence and second harmonic generation of tissues. In this study, we used intravital MPM to visualize various cochlear microstructures without any staining and non-invasively analyze the volume changes of the scala media (SM) without removing the overlying cochlear bone. The intravital MPM images revealed various tissue types, ranging from thin membranes to dense bone, as well as the spiral ganglion beneath the cochlear bone. The two-dimensional, cross-sectional, and serial z-stack intravital MPM images also revealed the spatial dilation of the SM in the temporal bone of pendrin-deficient mice. These findings suggest that intravital MPM might serve as a new method for obtaining microanatomical information regarding the cochlea, similar to standard histopathological analyses in the animal study for the cochlea. Given the capability of intravital MPM for detecting an increase in the volume of the SM in pendrin-deficient mice, it might be a promising new tool for assessing the pathophysiology of hearing loss in the future.

Hepcidin, Cathelicidin-1 and IL-8 as immunological markers of responsiveness in early developmental stages of rainbow trout.

PubMed

Santana, Paula A; Guzmán, Fanny; Forero, Juan C; Luna, Omar F; Mercado, Luis

2016-09-01

During the early developmental stage of salmonids, high mortality occurs largely as a result of pathogens. These cause low immune competence in fry, producing disease, decreasing production and finally leading to economic losses. Therefore, the aim of this study was to characterise the developmental stages in which rainbow trout acquires immune response capability when challenged with LPS from Pseudomona aeruginosa for 8 h, studying the hepcidin, cathelicidin-1 and IL-8. Total RNA was extracted from fry at 34, 42, 56 and 66 days post hatching (dph). Hepcidin and cathelicidin-1 transcripts were detected only at days 34 and 42, whereas the IL-8 transcript was detected from day 34 to day 66. To analyse the protein expression in the fry, polyclonal anti-peptide antibodies were generated in rabbit. These three immune sera demonstrated the ability to recognise the whole molecule in biological samples. Immunofluorescence showed that skin, gills and intestine mainly responded to the LPS challenge, indicating that these portals of pathogen entry are capturing LPS. This study constitutes a valuable approach, since it has the potential to identify molecules with biological activity that can be used to evaluate the status of fry in culture. Copyright © 2016 Elsevier Ltd. All rights reserved.

Designing a reliable leak bio-detection system for natural gas pipelines.

PubMed

Batzias, F A; Siontorou, C G; Spanidis, P-M P

2011-02-15

Monitoring of natural gas (NG) pipelines is an important task for economical/safety operation, loss prevention and environmental protection. Timely and reliable leak detection of gas pipeline, therefore, plays a key role in the overall integrity management for the pipeline system. Owing to the various limitations of the currently available techniques and the surveillance area that needs to be covered, the research on new detector systems is still thriving. Biosensors are worldwide considered as a niche technology in the environmental market, since they afford the desired detector capabilities at low cost, provided they have been properly designed/developed and rationally placed/networked/maintained by the aid of operational research techniques. This paper addresses NG leakage surveillance through a robust cooperative/synergistic scheme between biosensors and conventional detector systems; the network is validated in situ and optimized in order to provide reliable information at the required granularity level. The proposed scheme is substantiated through a knowledge based approach and relies on Fuzzy Multicriteria Analysis (FMCA), for selecting the best biosensor design that suits both, the target analyte and the operational micro-environment. This approach is illustrated in the design of leak surveying over a pipeline network in Greece. Copyright © 2010 Elsevier B.V. All rights reserved.

Radar-based collision avoidance for unmanned surface vehicles

NASA Astrophysics Data System (ADS)

Zhuang, Jia-yuan; Zhang, Lei; Zhao, Shi-qi; Cao, Jian; Wang, Bo; Sun, Han-bing

2016-12-01

Unmanned surface vehicles (USVs) have become a focus of research because of their extensive applications. To ensure safety and reliability and to perform complex tasks autonomously, USVs are required to possess accurate perception of the environment and effective collision avoidance capabilities. To achieve these, investigation into realtime marine radar target detection and autonomous collision avoidance technologies is required, aiming at solving the problems of noise jamming, uneven brightness, target loss, and blind areas in marine radar images. These technologies should also satisfy the requirements of real-time and reliability related to high navigation speeds of USVs. Therefore, this study developed an embedded collision avoidance system based on the marine radar, investigated a highly real-time target detection method which contains adaptive smoothing algorithm and robust segmentation algorithm, developed a stable and reliable dynamic local environment model to ensure the safety of USV navigation, and constructed a collision avoidance algorithm based on velocity obstacle (V-obstacle) which adjusts the USV's heading and speed in real-time. Sea trials results in multi-obstacle avoidance firstly demonstrate the effectiveness and efficiency of the proposed avoidance system, and then verify its great adaptability and relative stability when a USV sailing in a real and complex marine environment. The obtained results will improve the intelligent level of USV and guarantee the safety of USV independent sailing.

An astrometric facility for planetary detection on the space station

NASA Technical Reports Server (NTRS)

Nishioka, Kenji; Scargle, Jeffrey D.; Givens, John J.

1987-01-01

An Astrometric Telescope Facility (ATF) for planetary detection is being studied as a potential space station initial operating capability payload. The primary science objective of this mission is the detection and study of planetary systems around other stars. In addition, the facility will be capable of other astrometric measurements such as stellar motions of other galaxies and highly precise direct measurement of stellar distance within the Milky Way Galaxy. The results of a recently completed ATF preliminary systems definition study are summarized. Results of this study indicate that the preliminary concept for the facility is fully capable of meeting the science objective without the development of any new technologies. A simple straightforward operations approach was developed for the ATF. A real-time facility control is not normally required, but does maintain a near real-time ground monitoring capability for the facility and science data stream on a full-time basis. Facility observational sequences are normally loaded once a week. In addition, the preliminary system is designed to be fail-safe and single-fault tolerant. Routine interactions by the space station crew with the ATF will not be necessary, but onboard controls are provided for crew override as required for emergencies and maintenance.

Evaluation of eddy current and magnetic techniques for inspecting rebars in bridge barrier rails

NASA Astrophysics Data System (ADS)

Lo, C. C. H.; Nakagawa, N.

2013-01-01

This paper reports on a feasibility study of using eddy current (EC) and magnetic flux leakage (MFL) methods to detect corrosion damage in rebars that anchor concrete barrier rails to the road deck of bridge structures. EC and MFL measurements were carried out on standalone rebars with and without artificial defects of 25% and 50% material loss, using a commercial EC-based rebar locator and a MFL system that was developed using giant magnetoresistance sensors to detect leakage fluxes from the defects. Both techniques can readily detect the defects at a distance of 2.5″ (63.5 mm). The amplitudes of the EC and MFL signals vary monotonically with the amount of material loss, indicating the potential of using the techniques to quantify material loss of standalone rebars.

LACED

Science.gov Websites

Search Site submit Feynman Center for Innovation Los Alamos National Laboratory Collaboration for Explosives Detection Los Alamos National Laboratory Los Alamos Collaboration for Explosives Detection Menu is built upon Los Alamos' unparalleled explosive detection capabilities derived from the expertise of

Improved dual-loop detection system for collecting real-time truck data

DOT National Transportation Integrated Search

2005-02-01

The WSDOTs dual-loop detectors capability of measuring vehicle lengths makes the dual-loop detection system a potential real-time truck data source for freight movement study. However, a previous study found the WSDOT dual-loop detection system...

A gold@polydopamine core-shell nanoprobe for long-term intracellular detection of microRNAs in differentiating stem cells.

PubMed

Choi, Chun Kit K; Li, Jinming; Wei, Kongchang; Xu, Yang J; Ho, Lok Wai C; Zhu, Meiling; To, Kenneth K W; Choi, Chung Hang J; Bian, Liming

2015-06-17

The capability of monitoring the differentiation process in living stem cells is crucial to the understanding of stem cell biology and the practical application of stem-cell-based therapies, yet conventional methods for the analysis of biomarkers related to differentiation require a large number of cells as well as cell lysis. Such requirements lead to the unavoidable loss of cell sources and preclude real-time monitoring of cellular events. In this work, we report the detection of microRNAs (miRNAs) in living human mesenchymal stem cells (hMSCs) by using polydopamine-coated gold nanoparticles (Au@PDA NPs). The PDA shell facilitates the immobilization of fluorescently labeled hairpin DNA strands (hpDNAs) that can recognize specific miRNA targets. The gold core and PDA shell quench the fluorescence of the immobilized hpDNAs, and subsequent binding of the hpDNAs to the target miRNAs leads to their dissociation from Au@PDA NPs and the recovery of fluorescence signals. Remarkably, these Au@PDA-hpDNA nanoprobes can naturally enter stem cells, which are known for their poor transfection efficiency, without the aid of transfection agents. Upon cellular uptake of these nanoprobes, we observe intense and time-dependent fluorescence responses from two important osteogenic marker miRNAs, namely, miR-29b and miR-31, only in hMSCs undergoing osteogenic differentiation and living primary osteoblasts but not in undifferentiated hMSCs and 3T3 fibroblasts. Strikingly, our nanoprobes can afford long-term tracking of miRNAs (5 days) in the differentiating hMSCs without the need of continuously replenishing cell culture medium with fresh nanoprobes. Our results demonstrate the capability of our Au@PDA-hpDNA nanoprobes for monitoring the differentiation status of hMSCs (i.e., differentiating versus undifferentiated) via the detection of specific miRNAs in living stem cells. Our nanoprobes show great promise in the investigation of the long-term dynamics of stem cell differentiation, identification and isolation of specific cell types, and high-throughput drug screening.

Diffraction measurements using the LHC Beam Loss Monitoring System

NASA Astrophysics Data System (ADS)

Kalliokoski, Matti

2017-03-01

The Beam Loss Monitoring (BLM) system of the Large Hadron Collider protects the machine from beam induced damage by measuring the absorbed dose rates of beam losses, and by triggering beam dump if the rates increase above the allowed threshold limits. Although the detection time scales are optimized for multi-turn losses, information on fast losses can be recovered from the loss data. In this paper, methods in using the BLM system in diffraction studies are discussed.

Electrochemical immunosensor based on ensemble of nanoelectrodes for immunoglobulin IgY detection: application to identify hen's egg yolk in tempera paintings.

PubMed

Bottari, Fabio; Oliveri, Paolo; Ugo, Paolo

2014-02-15

A nanostructured electrochemical biosensor for detecting proteins of interest in work of art, in particular in tempera paintings, is presented. To determine egg yolk we focus here on the determination of immunoglobulin IgY. The transducers are nanoelectrode ensembles (NEEs), prepared via membrane templated electroless deposition of gold. Because of their geometrical and diffusion characteristics, NEEs are characterized by significantly low detection limits, moreover they display the capability of capturing proteins by interaction with the polycarbonate membrane of the NEE. At first, the proteic component of the paint is extracted by ultrasonication in an aqueous buffer, then IgY is captured by incubation on the NEE. The immunoglobulin is detected by treatment with anti-IgY labeled with horse radish peroxidase (Anti-IgY-HRP). The binding of the Anti-IgY-HRP is detected by recording the electrocatalytic signal caused by addition of H2O2 and methylene blue. The sensor detection capabilities are tested by analyzing both paint models, prepared in the lab, and real samples, from paintings of the XVIII-XX century. Multivariate exploratory analysis is applied to classify the voltammetric patterns, confirming the capability to differentiate egg-yolk tempera from other kind of tempera binders as well as from acrylic or oil paints. © 2013 Elsevier B.V. All rights reserved.

The application of an optical Fourier spectrum analyzer on detecting defects in mass-produced satellite photographs

NASA Technical Reports Server (NTRS)

Athale, R.; Lee, S. H.

1976-01-01

Various defects in mass-produced pictures transmitted to earth from a satellite are investigated. It is found that the following defects are readily detectable via Fourier spectrum analysis: (1) bit slip, (2) breakup causing loss of image, and (3) disabled track at the top of the imagery. The scratches made on the film during mass production, which are difficult to detect by visual observation, also show themselves readily in Fourier spectrum analysis. A relation is established between the number of scratches, their width and depth and the intensity of their Fourier spectra. Other defects that are found to be equally suitable for Fourier spectrum analysis or visual (image analysis) detection are synchronous loss without blurring of image, and density variation in gray scale. However, the Fourier spectrum analysis is found to be unsuitable for detection of such defects as pin holes, annotation error, synchronous loss with blurring of images, and missing image in the beginning of the work order. The design of an automated, real time system, which will reject defective films, is treated.

Experimental integration of quantum key distribution and gigabit-capable passive optical network

NASA Astrophysics Data System (ADS)

Sun, Wei; Wang, Liu-Jun; Sun, Xiang-Xiang; Mao, Yingqiu; Yin, Hua-Lei; Wang, Bi-Xiao; Chen, Teng-Yun; Pan, Jian-Wei

2018-01-01

Quantum key distribution (QKD) ensures information-theoretic security for the distribution of random bits between two remote parties. To extend QKD applications to fiber-to-the-home optical communications, such as gigabit-capable passive optical networks (GPONs), an effective method is the use of wavelength-division multiplexing. However, the Raman scattering noise from intensive classical traffic and the huge loss introduced by the beam splitter in a GPON severely limits the performance of QKD. Here, we demonstrate the integration of QKD and a commercial GPON system with fiber lengths up to 14 km, in which the maximum splitting ratio of the beam splitter reaches 1:64. By placing the QKD transmitter on the optical line terminal side, we reduce the Raman noise collected at the QKD receiver. Using a bypass structure, the loss of the beam splitter is circumvented effectively. Our results pave the way to extending the applications of QKD to last-mile communications.

Architecture for improved mass transport and system performance in redox flow batteries

NASA Astrophysics Data System (ADS)

Houser, Jacob; Pezeshki, Alan; Clement, Jason T.; Aaron, Douglas; Mench, Matthew M.

2017-05-01

In this work, electrochemical performance and parasitic losses are combined in an overall system-level efficiency metric for a high performance, all-vanadium redox flow battery. It was found that pressure drop and parasitic pumping losses are relatively negligible for high performance cells, i.e., those capable of operating at a high current density while at a low flow rate. Through this finding, the Equal Path Length (EPL) flow field architecture was proposed and evaluated. This design has superior mass transport characteristics in comparison with the standard serpentine and interdigitated designs at the expense of increased pressure drop. An Aspect Ratio (AR) design is discussed and evaluated, which demonstrates decreased pressure drop compared to the EPL design, while maintaining similar electrochemical performance under most conditions. This AR design is capable of leading to improved system energy efficiency for flow batteries of all chemistries.

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

Xu, Yun; Zhao, Mingyang; Khalid, Syed

The high voltage cathode material, LiMn 1.6Ni 0.4O 4, was prepared by a polymer-assisted method. The novelty of this paper is the substitution of Ni with Mn, which already exists in the crystal structure instead of other isovalent metal ion dopants which would result in capacity loss. The electrochemical performance testing including stability and rate capability was evaluated. The temperature was found to impose a change on the valence and structure of the cathode materials. Specifically, manganese tends to be reduced at a high temperature of 800 °C and leads to structural changes. The manganese substituted LiMn 1.5Ni 0.5O 4more » (LMN) has proved to be a good candidate material for Li-ion battery cathodes displaying good rate capability and capacity retention. Finally, the cathode materials processed at 550 °C showed a stable performance with negligible capacity loss for 400 cycles.« less

Early detection of changes in lung mechanics with oscillometry following bariatric surgery in severe obesity.

PubMed

Peters, Ubong; Hernandez, Paul; Dechman, Gail; Ellsmere, James; Maksym, Geoffrey

2016-05-01

Obesity is associated with respiratory symptoms that are reported to improve with weight loss, but this is poorly reflected in spirometry, and few studies have measured respiratory mechanics with oscillometry. We investigated whether early changes in lung mechanics following weight loss are detectable with oscillometry. Furthermore, we investigated whether the changes in lung mechanics measured in the supine position following weight loss are associated with changes in sleep quality. Nineteen severely obese female subjects (mean body mass index, 47.2 ± 6.6 kg/m(2)) were evaluated using spirometry, oscillometry, plethysmography, and the Pittsburgh Sleep Quality Index before and 5 weeks after bariatric surgery. These tests were conducted in both the upright and the supine position, and pre- and postbronchodilation with 200 μg of salbutamol. Five weeks after surgery, weight loss of 11.5 ± 2.5 kg was not associated with changes in spirometry and plethysmography, with the exception of functional residual capacity. There were also no changes in upright respiratory system resistance (Rrs) or reactance following weight loss. Importantly, however, in the supine position, weight loss caused a substantial reduction in Rrs. In addition, sleep quality improved significantly and was highly correlated with the reduction in supine Rrs. Prior to weight loss, subjects did not respond to the bronchodilator when assessed in the upright position with either spirometry or oscillometry; however, with modest weight loss, bronchodilator responsiveness returned to the normal range. Improvements in lung mechanics occur very early after weight loss, mostly in the supine position, resulting in improved sleep quality. These improvements are detectable with oscillometry but not with spirometry.

Prevalence of Dental Implants and Evaluation of Peri-implant Bone Levels in Patients Presenting to a Dental School: A Radiographic Cross-Sectional 2-Year Study.

PubMed

Alkan, Eylem Ayhan; Mau, Lian Ping; Schoolfield, John; Guest, Gary F; Cochran, David L

To evaluate the number of patients with dental implants who present to a dental school clinic for screening and to report the prevalence of peri-implant bone level change detected on digital panoramic radiographs of those subjects. Patient screening files for 9,422 patients over a 2-year period were examined to see how many patients presented with dental implants. Those patients with at least one implant were further evaluated by measuring the bone level on the mesial and distal sides of the implant using the screening radiograph. A total of 187 patients (2%) had at least one implant. In regard to implants, 423 were examined and 146 (33%) had no detectable bone loss defined as bone level below the top of the implant. When thresholds of bone loss were evaluated, 109 implants (25%) had ≥ 2 mm of bone loss on either the mesial or distal sides or both. The median bone loss was 1.74 mm for the 277 implants with detectable bone loss and 2.97 mm for the 109 implants that had ≥ 2 mm bone loss. Interestingly, patients who were ≥ 70 years of age had significantly (P = .03) more bone loss in the mandible compared with the maxilla, while patients who were 60 to 69 years of age had significantly greater loss in the maxilla. These data reveal that for patients presenting to the dental school for a screening over a 2-year period, 1.98% had one or more dental implants. Furthermore, those patients with implants had a minimum amount of bone loss as measured from the top of the implant.

Automatic Skin Lesion Segmentation Using Deep Fully Convolutional Networks With Jaccard Distance.

PubMed

Yuan, Yading; Chao, Ming; Lo, Yeh-Chi

2017-09-01

Automatic skin lesion segmentation in dermoscopic images is a challenging task due to the low contrast between lesion and the surrounding skin, the irregular and fuzzy lesion borders, the existence of various artifacts, and various imaging acquisition conditions. In this paper, we present a fully automatic method for skin lesion segmentation by leveraging 19-layer deep convolutional neural networks that is trained end-to-end and does not rely on prior knowledge of the data. We propose a set of strategies to ensure effective and efficient learning with limited training data. Furthermore, we design a novel loss function based on Jaccard distance to eliminate the need of sample re-weighting, a typical procedure when using cross entropy as the loss function for image segmentation due to the strong imbalance between the number of foreground and background pixels. We evaluated the effectiveness, efficiency, as well as the generalization capability of the proposed framework on two publicly available databases. One is from ISBI 2016 skin lesion analysis towards melanoma detection challenge, and the other is the PH2 database. Experimental results showed that the proposed method outperformed other state-of-the-art algorithms on these two databases. Our method is general enough and only needs minimum pre- and post-processing, which allows its adoption in a variety of medical image segmentation tasks.

Functionalized Nanopipettes: A Sensitive Tool for Pathogen Detection

NASA Astrophysics Data System (ADS)

Actis, P.; Jejelowo, O.; Pourmand, N.

2010-04-01

Nanopipette technology is capable of detecting and functional analyzing biomolecules. Preliminary experiments are demonstrating the sensitivity and selectivity of the technique with specific proteins targeting environmental toxins.

Dolphin sonar detection and discrimination capabilities

NASA Astrophysics Data System (ADS)

Au, Whitlow W. L.

2004-05-01

Dolphins have a very sophisticated short range sonar that surpasses all technological sonar in its capabilities to perform complex target discrimination and recognition tasks. The system that the U.S. Navy has for detecting mines buried under ocean sediment is one that uses Atlantic bottlenose dolphins. However, close examination of the dolphin sonar system will reveal that the dolphin acoustic hardware is fairly ordinary and not very special. The transmitted signals have peak-to-peak amplitudes as high as 225-228 dB re 1 μPa which translates to an rms value of approximately 210-213 dB. The transmit beamwidth is fairly broad at about 10o in both the horizontal and vertical planes and the receiving beamwidth is slightly broader by several degrees. The auditory filters are not very narrow with Q values of about 8.4. Despite these fairly ordinary features of the acoustic system, these animals still demonstrate very unusual and astonishing capabilities. Some of the capabilities of the dolphin sonar system will be presented and the reasons for their keen sonar capabilities will be discussed. Important features of their sonar include the broadband clicklike signals used, adaptive sonar search capabilities and large dynamic range of its auditory system.

Detection of free and covalently bound microcystins in animal tissues by liquid chromatography-tandem mass spectrometry.

PubMed

Neffling, Milla-Riina; Lance, Emilie; Meriluoto, Jussi

2010-03-01

Microcystins are cyanobacterial hepatotoxins capable of accumulation into animal tissues. The toxins act by inhibiting specific protein phosphatases and both non-covalent and covalent interactions occur. The 2-methyl-3-methoxy-4-phenylbutyric acid (MMPB) method determines the total, i.e. the sum of free and protein-bound microcystin in tissues. The aim of the method development in this paper was to tackle the problems with the MMPB methodology: the rather laborious workflow and the loss of material during different steps of the method. In the optimised workflow the oxidation recovery was of acceptable level (29-40%), the extraction efficiency good (62-97%), but the signal suppression effect from the matrix remained severe in our system (16-37% signal left). The extraction efficiency for the determination of the free, extractable microcystins, was found to be good, 52-100%, depending on the sample and the toxin variant and concentration. Copyright (c) 2009 Elsevier Ltd. All rights reserved.

Impact of the Usher syndrome on olfaction.

PubMed

Jansen, Fabian; Kalbe, Benjamin; Scholz, Paul; Mikosz, Marta; Wunderlich, Kirsten A; Kurtenbach, Stefan; Nagel-Wolfrum, Kerstin; Wolfrum, Uwe; Hatt, Hanns; Osterloh, Sabrina

2016-02-01

Usher syndrome is a genetically and clinically heterogeneous disease in humans, characterized by sensorineural hearing loss, retinitis pigmentosa and vestibular dysfunction. This disease is caused by mutations in genes encoding proteins that form complex networks in different cellular compartments. Currently, it remains unclear whether the Usher proteins also form networks within the olfactory epithelium (OE). Here, we describe Usher gene expression at the mRNA and protein level in the OE of mice and showed interactions between these proteins and olfactory signaling proteins. Additionally, we analyzed the odor sensitivity of different Usher syndrome mouse models using electro-olfactogram recordings and monitored significant changes in the odor detection capabilities in mice expressing mutant Usher proteins. Furthermore, we observed changes in the expression of signaling proteins that might compensate for the Usher protein deficiency. In summary, this study provides novel insights into the presence and purpose of the Usher proteins in olfactory signal transduction. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Use of IgY antibody to recombinant avian reovirus σC protein in the virus diagnostics.

PubMed

Jung, K M; Bae, E H; Jung, Y T; Kim, J W

2014-01-01

Avian reovirus (ARV) is an important agent of several diseases causing considerable losses in poultry farming. An outer capsid protein (σC) of ARV, is known as a virus-cell attachment protein essential for virus infectivity. In this study, the σC gene of ARV was cloned and expressed in Escherichia coli. The expressed recombinant protein was used as immunogen for raising a specific IgY antibody in laying hens. At 14 weeks post immunization, the antibody titers in serum and egg yolk reached 302,000 and 355,000, respectively. The IgY antibody was capable to neutralize ARV in BHK-21 cells and it strongly reacted in ELISA with ARV but not with heterologous viruses. The IgY antibody detected ARV in field samples of infected animal tissues in dot blot assay. These results suggest that an efficient, economic and rapid diagnostics of ARV can be performed routinely using the IgY antibody against a recombinant ARV σC protein.

Development of a Portable 3CCD Camera System for Multispectral Imaging of Biological Samples

PubMed Central

Lee, Hoyoung; Park, Soo Hyun; Noh, Sang Ha; Lim, Jongguk; Kim, Moon S.

2014-01-01

Recent studies have suggested the need for imaging devices capable of multispectral imaging beyond the visible region, to allow for quality and safety evaluations of agricultural commodities. Conventional multispectral imaging devices lack flexibility in spectral waveband selectivity for such applications. In this paper, a recently developed portable 3CCD camera with significant improvements over existing imaging devices is presented. A beam-splitter prism assembly for 3CCD was designed to accommodate three interference filters that can be easily changed for application-specific multispectral waveband selection in the 400 to 1000 nm region. We also designed and integrated electronic components on printed circuit boards with firmware programming, enabling parallel processing, synchronization, and independent control of the three CCD sensors, to ensure the transfer of data without significant delay or data loss due to buffering. The system can stream 30 frames (3-waveband images in each frame) per second. The potential utility of the 3CCD camera system was demonstrated in the laboratory for detecting defect spots on apples. PMID:25350510

Results from the First Two Flights of the Static Computer Memory Integrity Testing Experiment

NASA Technical Reports Server (NTRS)

Hancock, Thomas M., III

1999-01-01

This paper details the scientific objectives, experiment design, data collection method, and post flight analysis following the first two flights of the Static Computer Memory Integrity Testing (SCMIT) experiment. SCMIT is designed to detect soft-event upsets in passive magnetic memory. A soft-event upset is a change in the logic state of active or passive forms of magnetic memory, commonly referred to as a "Bitflip". In its mildest form a soft-event upset can cause software exceptions, unexpected events, start spacecraft safeing (ending data collection) or corrupted fault protection and error recovery capabilities. In it's most severe form loss of mission or spacecraft can occur. Analysis after the first flight (in 1991 during STS-40) identified possible soft-event upsets to 25% of the experiment detectors. Post flight analysis after the second flight (in 1997 on STS-87) failed to find any evidence of soft-event upsets. The SCMIT experiment is currently scheduled for a third flight in December 1999 on STS-101.

Locally oxidized silicon surface-plasmon Schottky detector for telecom regime.

PubMed

Goykhman, Ilya; Desiatov, Boris; Khurgin, Jacob; Shappir, Joseph; Levy, Uriel

2011-06-08

We experimentally demonstrate an on-chip nanoscale silicon surface-plasmon Schottky photodetector based on internal photoemission process and operating at telecom wavelengths. The device is fabricated using a self-aligned approach of local-oxidation of silicon (LOCOS) on silicon on insulator substrate, which provides compatibility with standard complementary metal-oxide semiconductor technology and enables the realization of the photodetector and low-loss bus photonic waveguide at the same fabrication step. Additionally, LOCOS technique allows avoiding lateral misalignment between the silicon surface and the metal layer to form a nanoscale Schottky contact. The fabricated devices showed enhanced detection capability for shorter wavelengths that is attributed to increased probability of the internal photoemission process. We found the responsivity of the nanodetector to be 0.25 and 13.3 mA/W for incident optical wavelengths of 1.55 and 1.31 μm, respectively. The presented device can be integrated with other nanophotonic and nanoplasmonic structures for the realization of monolithic opto-electronic circuitry on-chip.

Electric field feedback for Magneto(elasto)Electric magnetometer development

NASA Astrophysics Data System (ADS)

Yang, M.-T.; Zhuang, X.; Sing, M. Lam Chok; Dolabdjian, C.; Finkel, P.; Li, J.; Viehland, D.

2017-12-01

Magneto(elasto)Electric (ME) sensors based on magnetostrictive-piezoelectric composites have been investigated to evaluate their performances to sense a magnetic signal. Previous results have shown that the dielectric loss noise in the piezoelectric layer exhibits as the dominant intrinsic noise at low frequencies, which limits the sensor performances. Also, it has intrinsically no DC capability. To avoid a part of this limitation, modulation detection methods are evaluated through a frequency up-conversion technique [1-4]. Moreover, classical magnetic field feedback techniques can be used to increase the dynamic range, the sensing stability and the system linearity, too. In this paper, we propose a new method to feedback the system by using both the magneto-capacitance modulation and an electric field feedback technique. Our development shows the feasibility of the method and the results match with the theoretical description and material properties. Even if the present results are not totally satisfactory, they give the proof of concept and yield a way for the development of very low power magnetometers.

Wind Turbine Clutter Mitigation in Coastal UHF Radar

PubMed Central

Wang, Caijun; Jiang, Dapeng; Wen, Biyang

2014-01-01

Coastal UHF radar provides a unique capability to measure the sea surface dynamic parameters and detect small moving targets, by exploiting the low energy loss of electromagnetic waves propagating along the salty and good conducting ocean surface. It could compensate the blind zone of HF surface wave radar at close range and reach further distance than microwave radars. However, its performance is susceptible to wind turbines which are usually installed on the shore. The size of a wind turbine is much larger than the wavelength of radio waves at UHF band, which results in large radar cross section. Furthermore, the rotation of blades adds time-varying Doppler frequency to the clutter and makes the suppression difficult. This paper proposes a mitigation method which is based on the specific periodicity of wind turbine clutter and performed mainly in the time-frequency domain. Field experimental data of a newly developed UHF radar are used to verify this method, and the results prove its effectiveness. PMID:24550709

Wind turbine clutter mitigation in coastal UHF radar.

PubMed

Yang, Jing; Pan, Chao; Wang, Caijun; Jiang, Dapeng; Wen, Biyang

2014-01-01

Coastal UHF radar provides a unique capability to measure the sea surface dynamic parameters and detect small moving targets, by exploiting the low energy loss of electromagnetic waves propagating along the salty and good conducting ocean surface. It could compensate the blind zone of HF surface wave radar at close range and reach further distance than microwave radars. However, its performance is susceptible to wind turbines which are usually installed on the shore. The size of a wind turbine is much larger than the wavelength of radio waves at UHF band, which results in large radar cross section. Furthermore, the rotation of blades adds time-varying Doppler frequency to the clutter and makes the suppression difficult. This paper proposes a mitigation method which is based on the specific periodicity of wind turbine clutter and performed mainly in the time-frequency domain. Field experimental data of a newly developed UHF radar are used to verify this method, and the results prove its effectiveness.

a Framework for Voxel-Based Global Scale Modeling of Urban Environments

NASA Astrophysics Data System (ADS)

Gehrung, Joachim; Hebel, Marcus; Arens, Michael; Stilla, Uwe

2016-10-01

The generation of 3D city models is a very active field of research. Modeling environments as point clouds may be fast, but has disadvantages. These are easily solvable by using volumetric representations, especially when considering selective data acquisition, change detection and fast changing environments. Therefore, this paper proposes a framework for the volumetric modeling and visualization of large scale urban environments. Beside an architecture and the right mix of algorithms for the task, two compression strategies for volumetric models as well as a data quality based approach for the import of range measurements are proposed. The capabilities of the framework are shown on a mobile laser scanning dataset of the Technical University of Munich. Furthermore the loss of the compression techniques is evaluated and their memory consumption is compared to that of raw point clouds. The presented results show that generation, storage and real-time rendering of even large urban models are feasible, even with off-the-shelf hardware.

Crosscutting Airborne Remote Sensing Technologies for Oil and Gas and Earth Science Applications

NASA Technical Reports Server (NTRS)

Aubrey, A. D.; Frankenberg, C.; Green, R. O.; Eastwood, M. L.; Thompson, D. R.; Thorpe, A. K.

2015-01-01

Airborne imaging spectroscopy has evolved dramatically since the 1980s as a robust remote sensing technique used to generate 2-dimensional maps of surface properties over large spatial areas. Traditional applications for passive airborne imaging spectroscopy include interrogation of surface composition, such as mapping of vegetation diversity and surface geological composition. Two recent applications are particularly relevant to the needs of both the oil and gas as well as government sectors: quantification of surficial hydrocarbon thickness in aquatic environments and mapping atmospheric greenhouse gas components. These techniques provide valuable capabilities for petroleum seepage in addition to detection and quantification of fugitive emissions. New empirical data that provides insight into the source strength of anthropogenic methane will be reviewed, with particular emphasis on the evolving constraints enabled by new methane remote sensing techniques. Contemporary studies attribute high-strength point sources as significantly contributing to the national methane inventory and underscore the need for high performance remote sensing technologies that provide quantitative leak detection. Imaging sensors that map spatial distributions of methane anomalies provide effective techniques to detect, localize, and quantify fugitive leaks. Airborne remote sensing instruments provide the unique combination of high spatial resolution (<1 m) and large coverage required to directly attribute methane emissions to individual emission sources. This capability cannot currently be achieved using spaceborne sensors. In this study, results from recent NASA remote sensing field experiments focused on point-source leak detection, will be highlighted. This includes existing quantitative capabilities for oil and methane using state-of-the-art airborne remote sensing instruments. While these capabilities are of interest to NASA for assessment of environmental impact and global climate change, industry similarly seeks to detect and localize leaks of both oil and methane across operating fields. In some cases, higher sensitivities desired for upstream and downstream applications can only be provided by new airborne remote sensing instruments tailored specifically for a given application. There exists a unique opportunity for alignment of efforts between commercial and government sectors to advance the next generation of instruments to provide more sensitive leak detection capabilities, including those for quantitative source strength determination.

Early pregnancy factor (EPF) as a marker for detecting subclinical embryonic loss in clomiphene citrate-treated women.

PubMed

Shahani, S K; Moniz, C L; Gokral, J S; Meherji, P K

1995-05-01

A discrepancy exists between the apparently normal ovulation and the pregnancy rates in women treated with clomiphene citrate (CC). Our previous studies have indicated that immuno-suppressive "early pregnancy factor" (EPF) is a novel marker to detect subclinical embryonic loss in infertile women. In the present study EPF was used as a marker to detect subclinical embryonic loss in women treated with CC with/without gonadotropins. In some of the women treated with CC, conception was assisted by artificial insemination with husband's semen (AIH). Our results have indicated that fertilization occurred (EPF + ve) in 47.7% (52/109) of women treated with CC with/without gonadotropins; 13.46% (7/52) retained the fetus and continued pregnancy till full term, whereas 78.9% (41/52) did not retain the fetuses. In the group where after stimulation, conception was assisted by AIH, fertilization was observed in 38.24% (26/68), retention in 11.54% (3/26) but subclinical embryonic loss was observed in 80.8% (21/26) cases. Thus, our results have indicated that subclinical embryonic loss may account for some of the discrepancy observed between the apparently normal ovulation and the pregnancy rates in women treated with clomiphene citrate.

First detection of rotational CO line emission in a red giant branch star

NASA Astrophysics Data System (ADS)

Groenewegen, M. A. T.

2014-01-01

Context. For stars with initial masses below ~1 M⊙, the mass loss during the first red giant branch (RGB) phase dominates mass loss in the later asymptotic giant branch (AGB) phase. Nevertheless, mass loss on the RGB is still often parameterised by a simple Reimers law in stellar evolution models. Aims: To try to detect CO thermal emission in a small sample of nearby RGB stars with reliable Hipparcos parallaxes that were shown to have infrared excess in an earlier paper. Methods: A sample of five stars was observed in the CO J = 2-1 and J = 3-2 lines with the IRAM and APEX telescopes. Results: One star, the one with the largest mass-loss rate based on the previous analysis of the spectral energy distribution, was detected. The expansion velocity is unexpectedly large at 12 km s-1. The line profile and intensity are compared to the predictions from a molecular line emission code. The standard model predicts a double-peaked profile, while the observations indicate a flatter profile. A model that does fit the data has a much smaller CO envelope (by a factor of 3), and a CO abundance that is two times larger and/or a larger mass-loss rate than the standard model. This could indicate that the phase of large mass loss has only recently started. Conclusions: The detection of CO in an RGB star with a luminosity of only ~1300 L⊙ and a mass-loss rate as low as a few 10-9M⊙ yr-1 is important and the results also raise new questions. However, ALMA observations are required in order to study the mass-loss process of RGB stars in more detail, both for reasons of sensitivity (6 h of integration in superior weather at IRAM were needed to get a 4σ detection in the object with the largest detection probability), and spatial resolution (to determine the size of the CO envelope). Based on observations made with ESO telescopes at the La Silla Paranal Observatory under programme ID 091.D-0073 (ESO time) and 091.F-9322 (Swedish time). Based on observations with the Atacama Pathfinder EXperiment (APEX) telescope. APEX is a collaboration between the Max Planck Institute for Radio Astronomy, the European Southern Observatory, and the Onsala Space Observatory. Based on observations carried out with the IRAM 30 m Telescope under programme 183-11. IRAM is supported by INSU/CNRS (France), MPG (Germany), and IGN (Spain).

Reply to "Comment on 'Cosmic-ray-driven reaction and greenhouse effect of halogenated molecules: Culprits for atmospheric ozone depletion and global climate change' by Rolf Müller and Jens-Uwe Grooß"

NASA Astrophysics Data System (ADS)

Lu, Q.-B.

2014-04-01

In their Comment, Müller and Grooß continuously use problematic "observed data" and misleading arguments to make a case against our CRE mechanism of the ozone hole and CFC-warming mechanism of global climate change. They make the groundless assertion that the CRE theory cannot be considered as an independent process for ozone loss in the polar stratosphere. Their claim that the impact of the CRE mechanism on polar chlorine activation and ozone loss in the stratosphere would be limited does not agree with the observed data over the past decades. They also make many contradictory and fact-distorting arguments that "There is no polar ozone loss in darkness, there is no apparent 11-year periodicity in polar total ozone measurements, the age of air in the polar lower stratosphere is much older than 1-2 years, and the reported detection of a pronounced recovery (by about 20-25%) in Antarctic total ozone measurements by the year 2010 is in error." These assertions ignore and contradict a great deal of robust observed data from both laboratory and field measurements reported in the literature including their own publications. Their new argument for the photodissociation of CFCs on PSCs also contradicts their previous extraordinary efforts including the use of fabricated "ACE-FTS satellite data" to argue for no physical/chemical loss of CFCs in the winter lower polar stratosphere. Finally, they do not provide any scientific evidence to support their criticism for the no physical basis of the CFC-warming theory and its conclusions. In summary, their misleading arguments and false "data" do not change the convincing conclusion reached by robust observations in my recent paper that both the CRE mechanism and the CFC-warming mechanism not only provide new fundamental understandings of the O3 hole and global climate change but have superior predictive capabilities, compared with the conventional models.

Efficient direct yaw moment control: tyre slip power loss minimisation for four-independent wheel drive vehicle

NASA Astrophysics Data System (ADS)

Kobayashi, Takao; Katsuyama, Etsuo; Sugiura, Hideki; Ono, Eiichi; Yamamoto, Masaki

2018-05-01

This paper proposes an efficient direct yaw moment control (DYC) capable of minimising tyre slip power loss on contact patches for a four-independent wheel drive vehicle. Simulations identified a significant power loss reduction with a direct yaw moment due to a change in steer characteristics during acceleration or deceleration while turning. Simultaneously, the vehicle motion can be stabilised. As a result, the proposed control method can ensure compatibility between vehicle dynamics performance and energy efficiency. This paper also describes the results of a full-vehicle simulation that was conducted to examine the effectiveness of the proposed DYC.

Extreme energy cosmic rays (EECR) observation capabilities of an "Airwatch from Space" mission.

NASA Astrophysics Data System (ADS)

de Marzo, C. N.

1999-01-01

The longitudinal development and other characteristics of the EECR induced atmospheric showers can be studied from space by detecting the fluorescence light induced in the atmospheric nitrogen. According to the Airwatch concept a single fast detector can be used for measuring both intensity and time development of the streak of fluorescence light produced by the atmospheric shower induced by an EECR. In the present communication the detection capabilities for the EECR observation from space are discussed.

Receptors useful for gas phase chemical sensing

DOEpatents

Jaworski, Justyn W; Lee, Seung-Wuk; Majumdar, Arunava; Raorane, Digvijay A

2015-02-17

The invention provides for a receptor, capable of binding to a target molecule, linked to a hygroscopic polymer or hydrogel; and the use of this receptor in a device for detecting the target molecule in a gaseous and/or liquid phase. The invention also provides for a method for detecting the presence of a target molecule in the gas phase using the device. In particular, the receptor can be a peptide capable of binding a 2,4,6-trinitrotoluene (TNT) or 2,4,-dinitrotoluene (DNT).

Detection and differentiation of coxiella burnetii in biological fluids

DOEpatents

Frazier, Marvin E.; Mallavia, Louis P.; Samuel, James E.; Baca, Oswald G.

1993-01-01

Methods for detecting the presence of Coxiella burnetii in biological samples, as well as a method for differentiating strains of C. burnetii that are capable of causing acute disease from those strains capable of causing chronic disease are disclosed. The methods generally comprise treating cells contained within the biological sample to expose cellular DNA, and hybridizing the cellular DNA with a DNA probe containing DNA sequences that specifically hybridize with C. burnetii DNA of strains associated with the capacity to cause acute or chronic disease.

Influenza sensor

DOEpatents

Swanson, Basil I.; Song, Xuedong; Unkefer, Clifford; Silks, III, Louis A.; Schmidt, Jurgen G.

2003-09-30

A sensor for the detection of tetrameric multivalent neuraminidase within a sample is disclosed, where a positive detection indicates the presence of a target virus within the sample. Also disclosed is a trifunctional composition of matter including a trifunctional linker moiety with groups bonded thereto including (a) an alkyl chain adapted for attachment to a substrate, (b) a fluorescent moiety capable of generating a fluorescent signal, and (c) a recognition moiety having a spacer group of a defined length thereon, the recognition moiety capable of binding with tetrameric multivalent neuraminidase.

Influenza Sensor

DOEpatents

Swanson, Basil I.; Song, Xuedong; Unkefer, Clifford; Silks, III, Louis A.; Schmidt, Jurgen G.

2006-03-28

A sensor for the detection of tetrameric multivalent neuraminidase within a sample is disclosed, where a positive detection indicates the presence of a target virus within the sample. Also disclosed is a trifunctional composition of matter including a trifunctional linker moiety with groups bonded thereto including (a) an alkyl chain adapted for attachment to a substrate, (b) a fluorescent moiety capable of generating a fluorescent signal, and (c) a recognition moiety having a spacer group of a defined length thereon, the recognition moiety capable of binding with tetrameric multivalent neuraminidase.

Influenza Sensor

DOEpatents

Swanson, Basil I.; Song, Xuedong; Unkefer, Clifford; Silks, III, Louis A.; Schmidt, Jurgen G.

2005-05-17

A sensor for the detection of tetrameric multivalent neuraminidase within a sample is disclosed, where a positive detection indicates the presence of a target virus within the sample. Also disclosed is a trifunctional composition of matter including a trifunctional linker moiety with groups bonded thereto including (a) an alkyl chain adapted for attachment to a substrate, (b) a fluorescent moiety capable of generating a fluorescent signal, and (c) a recognition moiety having a spacer group of a defined length thereon, the recognition moiety capable of binding with tetrameric multivalent neuraminidase.

Visual Reading Method for Detection of Bacterial Tannase

PubMed Central

Osawa, R.; Walsh, T. P.

1993-01-01

Tannase activity of bacteria capable of degrading tannin-protein complexes was determined by a newly developed visual reading method. The method is based on two phenomena: (i) the ability of tannase to hydrolyze methyl gallate to release free gallic acid and (ii) the green to brown coloration of gallic acid after prolonged exposure to oxygen in an alkaline condition. The method has been successfully used to detect the presence of tannase in the cultures of bacteria capable of degrading tannin-protein complexes. PMID:16348918

Time stamping of single optical photons with 10 ns resolution

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

Chakaberia, Irakli; Cotlet, Mircea; Fisher-Levine, Merlin

High spatial and temporal resolution are key features for many modern applications, e.g. mass spectrometry, probing the structure of materials via neutron scattering, studying molecular structure, etc. Fast imaging also provides the capability of coincidence detection, and the further addition of sensitivity to single optical photons with the capability of timestamping them further broadens the field of potential applications. Here, photon counting is already widely used in X-ray imaging, where the high energy of the photons makes their detection easier.

Time stamping of single optical photons with 10 ns resolution

DOE PAGES

Chakaberia, Irakli; Cotlet, Mircea; Fisher-Levine, Merlin; ...

2017-05-08

High spatial and temporal resolution are key features for many modern applications, e.g. mass spectrometry, probing the structure of materials via neutron scattering, studying molecular structure, etc. Fast imaging also provides the capability of coincidence detection, and the further addition of sensitivity to single optical photons with the capability of timestamping them further broadens the field of potential applications. Here, photon counting is already widely used in X-ray imaging, where the high energy of the photons makes their detection easier.

Trace level detection of analytes using artificial olfactometry

NASA Technical Reports Server (NTRS)

Lewis, Nathan S. (Inventor); Severin, Erik J. (Inventor); Wong, Bernard (Inventor)

2002-01-01

The present invention provides a device for detecting the presence of an analyte, such as for example, a lightweight device, including: a sample chamber having a fluid inlet port for the influx of the analyte; a fluid concentrator in flow communication with the sample chamber wherein the fluid concentrator has an absorbent material capable of absorbing the analyte and capable of desorbing a concentrated analyte; and an array of sensors in fluid communication with the concentrated analyte to be released from the fluid concentrator.

Neutron detection in a high gamma-ray background with EJ-301 and EJ-309 liquid scintillators

NASA Astrophysics Data System (ADS)

Stevanato, L.; Cester, D.; Nebbia, G.; Viesti, G.

2012-10-01

Using a fast digitizer, the neutron-gamma discrimination capability of the new liquid scintillator EJ-309 is compared with that obtained using standard EJ-301. Moreover the capability of both the scintillation detectors to identify a weak neutron source in a high gamma-ray background is demonstrated. The probability of neutron detection is PD=95% at 95% confidence level for a gamma-ray background corresponding to a dose rate of 100 μSv/h.

Robust flight design for an advanced launch system vehicle

NASA Astrophysics Data System (ADS)

Dhand, Sanjeev K.; Wong, Kelvin K.

Current launch vehicle trajectory design philosophies are generally based on maximizing payload capability. This approach results in an expensive trajectory design process for each mission. Two concepts of robust flight design have been developed to significantly reduce this cost: Standardized Trajectories and Command Multiplier Steering (CMS). These concepts were analyzed for an Advanced Launch System (ALS) vehicle, although their applicability is not restricted to any particular vehicle. Preliminary analysis has demonstrated the feasibility of these concepts at minimal loss in payload capability.

Free-Swinging Failure Tolerance for Robotic Manipulators

NASA Technical Reports Server (NTRS)

English, James

1997-01-01

Under this GSRP fellowship, software-based failure-tolerance techniques were developed for robotic manipulators. The focus was on failures characterized by the loss of actuator torque at a joint, called free-swinging failures. The research results spanned many aspects of the free-swinging failure-tolerance problem, from preparing for an expected failure to discovery of postfailure capabilities to establishing efficient methods to realize those capabilities. Developed algorithms were verified using computer-based dynamic simulations, and these were further verified using hardware experiments at Johnson Space Center.

Waveguide device and method for making same

DOEpatents

Forman, Michael A [San Francisco, CA

2007-08-14

A monolithic micromachined waveguide device or devices with low-loss, high-power handling, and near-optical frequency ranges is set forth. The waveguide and integrated devices are capable of transmitting near-optical frequencies due to optical-quality sidewall roughness. The device or devices are fabricated in parallel, may be mass produced using a LIGA manufacturing process, and may include a passive component such as a diplexer and/or an active capping layer capable of particularized signal processing of the waveforms propagated by the waveguide.

Silicon Photomultiplier Performance in High ELectric Field

NASA Astrophysics Data System (ADS)

Montoya, J.; Morad, J.

2016-12-01

Roughly 27% of the universe is thought to be composed of dark matter. The Large Underground Xenon (LUX) relies on the emission of light from xenon atoms after a collision with a dark matter particle. After a particle interaction in the detector, two things can happen: the xenon will emit light and charge. The charge (electrons), in the liquid xenon needs to be pulled into the gas section so that it can interact with gas and emit light. This allows LUX to convert a single electron into many photons. This is done by applying a high voltage across the liquid and gas regions, effectively ripping electrons out of the liquid xenon and into the gas. The current device used to detect photons is the photomultiplier tube (PMT). These devices are large and costly. In recent years, a new technology that is capable of detecting single photons has emerged, the silicon photomultiplier (SiPM). These devices are cheaper and smaller than PMTs. Their performance in a high electric fields, such as those found in LUX, are unknown. It is possible that a large electric field could introduce noise on the SiPM signal, drowning the single photon detection capability. My hypothesis is that SiPMs will not observe a significant increase is noise at an electric field of roughly 10kV/cm (an electric field within the range used in detectors like LUX). I plan to test this hypothesis by first rotating the SiPMs with no applied electric field between two metal plates roughly 2 cm apart, providing a control data set. Then using the same angles test the dark counts with the constant electric field applied. Possibly the most important aspect of LUX, is the photon detector because it's what detects the signals. Dark matter is detected in the experiment by looking at the ratio of photons to electrons emitted for a given interaction in the detector. Interactions with a low electron to photon ratio are more like to be dark matter events than those with a high electron to photon ratio. The ability to distinguish these ratios relies on the high sensitivity to single photons. To achieve a similar sensitivity to dark matter interactions as LUX, the new SiPM devices need to operate in the same conditions without any loss in sensitivity to single photons. Knowing that this new type of technology operates in high electric field without issues, could save hundreds of thousands of dollars and valuable space.

State-of-the-art technologies for intrusion and obstacle detection for railroad operations

DOT National Transportation Integrated Search

2007-07-01

This report provides an update on the state-of-the-art technologies with intrusion and obstacle detection capabilities for rail rights of way (ROW) and crossings. A workshop entitled Intruder and Obstacle Detection Systems (IODS) for Railroads Requir...

On amplifications of photonuclear neutron flux in thunderstorm atmosphere and possibility of detecting them

NASA Astrophysics Data System (ADS)

Babich, L. P.; Bochkov, E. I.; Kutsyk, I. M.; Zalyalov, A. N.

2013-05-01

The reliability of communications reporting observations of neutron flux enhancements in thunderstorm atmosphere is analyzed. The analysis is motivated by the fact that the employed gas-discharge counters on the basis of reactions 3He( n, p)3H and 10B( n; 4He, γ)7Li detect not only neutrons but any penetrating radiations. Photonuclear reactions are capable of accounting for the possible amplifications of neutron flux in thunder-storm atmosphere since in correlation with thunderstorms γ-ray flashes were repeatedly observed with spectra extending high above the threshold of photonuclear reactions in air. By numerical simulations, it was demonstrated that γ-ray pulses detected in thunderstorm atmosphere are capable of generating photonuclear neutrons in numbers sufficient to be detected even at sea level.

Perspectives of Maine Forest Cover Change from Landsat Imagery and Forest Inventory Analysis (FIA)

Treesearch

Steven Sader; Michael Hoppus; Jacob Metzler; Suming Jin

2005-01-01

A forest change detection map was developed to document forest gains and losses during the decade of the 1990s. The effectiveness of the Landsat imagery and methods for detecting Maine forest cover change are indicated by the good accuracy assessment results: forest-no change, forest loss, and forest gain accuracy were 90, 88, and 92% respectively, and the good...

Evolutionary Instability of Symbiotic Function in Bradyrhizobium japonicum

PubMed Central

Sachs, Joel L.; Russell, James E.; Hollowell, Amanda C.

2011-01-01

Bacterial mutualists are often acquired from the environment by eukaryotic hosts. However, both theory and empirical work suggest that this bacterial lifestyle is evolutionarily unstable. Bacterial evolution outside of the host is predicted to favor traits that promote an independent lifestyle in the environment at a cost to symbiotic function. Consistent with these predictions, environmentally-acquired bacterial mutualists often lose symbiotic function over evolutionary time. Here, we investigate the evolutionary erosion of symbiotic traits in Bradyrhizobium japonicum, a nodulating root symbiont of legumes. Building on a previous published phylogeny we infer loss events of nodulation capability in a natural population of Bradyrhizobium, potentially driven by mutation or deletion of symbiosis loci. Subsequently, we experimentally evolved representative strains from the symbiont population under host-free in vitro conditions to examine potential drivers of these loss events. Among Bradyrhizobium genotypes that evolved significant increases in fitness in vitro, two exhibited reduced symbiotic quality, but no experimentally evolved strain lost nodulation capability or evolved any fixed changes at six sequenced loci. Our results are consistent with trade-offs between symbiotic quality and fitness in a host free environment. However, the drivers of loss-of-nodulation events in natural Bradyrhizobium populations remain unknown. PMID:22073160

Evidence from aerial photography of structural loss of coral reefs at Barbados, West Indies

NASA Astrophysics Data System (ADS)

Lewis, J.

2002-04-01

In response to concerns about widespread degradation of coral reefs at Barbados, West Indies, over the past two decades, maps and planimetric areas of 20 fringing coral reefs were estimated from enlargements of aerial photographs of the island, using geographic information system analysis. There were statistically significant reductions in reef areas over a 40-year period from 1950 to 1991. Areal losses exceeding measurement and boundary interpretation errors of 10% were detected on eight of the 20 reefs. Ground validation carried out by divers on six of the reefs confirmed physical losses of reef structures and accumulation of rubble and sand substrata at sites where substantial planimetric area loss was detected on aerial photographs. Structural losses occurred along the "spur and groove" system of the reef-seaward edge, within deep channels or breaches in the reef front, and along the flanks or ends of reefs. The location and nature of the observed losses suggest that storm damage and seasonal alterations in beach morphology are the two most important factors contributing to geomorphological structural loss of the reefs.

Prospects for detecting decreasing exoplanet frequency with main-sequence age using PLATO

NASA Astrophysics Data System (ADS)

Veras, Dimitri; Brown, David J. A.; Mustill, Alexander J.; Pollacco, Don

2015-10-01

The space mission PLATO will usher in a new era of exoplanetary science by expanding our current inventory of transiting systems and constraining host star ages, which are currently highly uncertain. This capability might allow PLATO to detect changes in planetary system architecture with time, particularly because planetary scattering due to Lagrange instability may be triggered long after the system was formed. Here, we utilize previously published instability time-scale prescriptions to determine PLATO's capability to detect a trend of decreasing planet frequency with age for systems with equal-mass planets. For two-planet systems, our results demonstrate that PLATO may detect a trend for planet masses which are at least as massive as super-Earths. For systems with three or more planets, we link their initial compactness to potentially detectable frequency trends in order to aid future investigations when these populations will be better characterized.

Prospects for detecting decreasing exoplanet frequency with main-sequence age using PLATO

NASA Astrophysics Data System (ADS)

Veras, D.; Brown, D. J. A.; Mustill, A. J.; Pollacco, D.

2017-09-01

The space mission PLATO will usher in a new era of exoplanetary science by expanding our current inventory of transiting systems and constraining host star ages, which are currently highly uncertain. This capability might allow PLATO to detect changes in planetary system architecture with time, particularly because planetary scattering due to Lagrange instability may be triggered long after the system was formed. Here, we utilize previously published instability time-scale prescriptions to determine PLATO's capability to detect a trend of decreasing planet frequency with age for systems with equal- mass planets. For two-planet systems, our results demonstrate that PLATO may detect a trend for planet masses which are at least as massive as super-Earths. For systems with three or more planets, we link their initial compactness to potentially detectable frequency trends in order to aid future investigations when these populations will be better characterized.

Explicit and Implicit Components of the Emotional Processing in Non-organic Vision Loss: Behavioral Evidence About the Role of Fear in Functional Blindness

PubMed Central

Scarpina, Federica; Melzi, Lisa; Castelnuovo, Gianluca; Mauro, Alessandro; Marzoli, Stefania B.; Molinari, Enrico

2018-01-01

Non-organic vision loss (NOVL), a functional partial or global vision loss, might be considered a manifestation of conversion disorder. The few previous studies focused on investigating the relationship between cerebral activity and subjective symptoms in NOVL; however, the emotional processing is still neglected. In the present case-controls study, we investigated the capability of two individuals diagnosed with NOVL to recognize implicitly the emotions of fear and anger; this was assessed through a facial emotion recognition task based on the redundant target effect. In addition, the level of alexithymia was measured by asking them to judge explicitly their ability to identify and describe emotions. Both individuals showed selective difficulties in recognizing the emotion of fear when their performance was contrasted with a matched control sample; they also mislabeled other emotional stimuli, judging them as fearful, when they were not. However, they did not report alexithymia when measured using a standard questionnaire. This preliminary investigation reports a mismatch between the implicit (i.e., the behavior in the experimental paradigm) and the explicit (i.e., the subjective evaluation of one’s own emotional capability) components of the emotional processing in NOVL. Moreover, fear seems to represent a critical emotion in this condition, as has been reported in other psychiatric disorders. However, possible difficulties in the emotional processing of fear would emerge only when they are inferred from an implicit behavior, instead of a subjective evaluation of one’s own emotional processing capability. PMID:29692751

Monolithic graphene transistor biointerface.

PubMed

Nam, SungWoo; Lee, Mi-Sun; Park, Jang-Ung

2012-01-01

We report monolithic integration of graphene and graphite for all-carbon integrated bioelectronics. First, we demonstrate that the electrical properties of graphene and graphite can be modulated by controlling the number of graphene layers, and such capabilities allow graphene to be used as active channels and graphite as metallic interconnects for all-carbon bioelectronics. Furthermore, we show that monolithic graphene-graphite devices exhibit mechanical flexibility and robustness while their electrical responses are not perturbed by mechanical deformation, demonstrating their unique electromechanical properties. Chemical sensing capability of all-carbon integrated bioelectronics is manifested in real-time, complementary pH detection. These unique capabilities of our monolithic graphene-graphite bioelectronics could be exploited in chemical and biological detection and conformal interface with biological systems in the future.

Metamaterial split ring resonator as a sensitive mechanical vibration sensor

NASA Astrophysics Data System (ADS)

Sikha Simon, K.; Chakyar, Sreedevi P.; Andrews, Jolly; Joseph V., P.

2017-06-01

This paper introduces a sensitive vibration sensor based on microwave metamaterial Split Ring Resonator (SRR) capable of detecting any ground vibration. The experimental setup consists of single Broad-side Coupled SRR (BCSRR) unit fixed on a cantilever capable of sensitive vibrations. It is arranged between transmitting and receiving probes of a microwave measurement system. The absorption level variations at the resonant frequency due to the displacement from the reference plane of SRR, which is a function of the strength of external mechanical vibration, is analyzed. This portable and cost effective sensor working on a single frequency is observed to be capable of detecting even very weak vibrations. This may find potential applications in the field of tamper-proofing, mining, quarrying and earthquake sensing.

Hyperspectral sensing to detect the impact of herbicide drift on cotton growth and yield

NASA Astrophysics Data System (ADS)

Suarez, L. A.; Apan, A.; Werth, J.

2016-10-01

Yield loss in crops is often associated with plant disease or external factors such as environment, water supply and nutrient availability. Improper agricultural practices can also introduce risks into the equation. Herbicide drift can be a combination of improper practices and environmental conditions which can create a potential yield loss. As traditional assessment of plant damage is often imprecise and time consuming, the ability of remote and proximal sensing techniques to monitor various bio-chemical alterations in the plant may offer a faster, non-destructive and reliable approach to predict yield loss caused by herbicide drift. This paper examines the prediction capabilities of partial least squares regression (PLS-R) models for estimating yield. Models were constructed with hyperspectral data of a cotton crop sprayed with three simulated doses of the phenoxy herbicide 2,4-D at three different growth stages. Fibre quality, photosynthesis, conductance, and two main hormones, indole acetic acid (IAA) and abscisic acid (ABA) were also analysed. Except for fibre quality and ABA, Spearman correlations have shown that these variables were highly affected by the chemical. Four PLS-R models for predicting yield were developed according to four timings of data collection: 2, 7, 14 and 28 days after the exposure (DAE). As indicated by the model performance, the analysis revealed that 7 DAE was the best time for data collection purposes (RMSEP = 2.6 and R2 = 0.88), followed by 28 DAE (RMSEP = 3.2 and R2 = 0.84). In summary, the results of this study show that it is possible to accurately predict yield after a simulated herbicide drift of 2,4-D on a cotton crop, through the analysis of hyperspectral data, thereby providing a reliable, effective and non-destructive alternative based on the internal response of the cotton leaves.

Pavement Subsidence in the Cumberland Gap Tunnel, USA: A Story of Groundwater Chemistry

NASA Astrophysics Data System (ADS)

Zhu, J.; Currens, J. C.; Webb, S. E.; Rister, B. W.

2014-12-01

Cumberland Gap Tunnel was constructed in 1996 to improve highway travel between southeastern Kentucky and northeastern Tennessee and to restore Cumberland Gap to its historical appearance. About five years after construction, the concrete pavement in the tunnel began to exhibit noticeable signs of subsidence. Ground penetrating radar surveys detected voids in many areas of the limestone roadbed aggregate beneath the pavement. Field investigations conducted by the Kentucky Geological Survey and Kentucky Transportation Center from 2006 to 2008 discovered that groundwater was flowing from the bedrock invert into the aggregate along many parts of the tunnel. Average groundwater discharge from the tunnel was measured at approximately 1700 m3/d. We analyzed 265 groundwater samples collected from aggregate in different parts of the tunnel roadbed during low and high flow conditions. Calculated calcite saturation indices indicated that the groundwater was geochemically aggressive and capable of continuously dissolving calcite in the limestone aggregate although pH values of these water samples were near neutral. We also conducted an in-situ dissolution experiment by placing eight baskets filled with limestone aggregate beneath the roadbed in different locations in the tunnel for 178 days. At the end of the experiment, the limestone aggregate in contact with groundwater exhibited visual signs of dissolution and lost mass, and the highest mass loss recorded was 3.4 percent. Mass loss calculations based on kinetic models of calcite mineral and water samples taken near the baskets matched well with the actual measured mass losses, confirming that dissolution of calcite by the groundwater was the primary cause of the roadbed subsidence problem. Based on these findings, we suggested the limestone aggregate be replaced with noncarbonate (granite) aggregate to mitigate future road subsidence. The suggestion was adopted, and the repair was completed in early 2014.

Erosion rills offset the efficacy of vegetated buffer strips to mitigate pesticide exposure in surface waters.

PubMed

Stehle, Sebastian; Dabrowski, James Michael; Bangert, Uli; Schulz, Ralf

2016-03-01

Regulatory risk assessment considers vegetated buffer strips as effective risk mitigation measures for the reduction of runoff-related pesticide exposure of surface waters. However, apart from buffer strip widths, further characteristics such as vegetation density or the presence of erosion rills are generally neglected in the determination of buffer strip mitigation efficacies. This study conducted a field survey of fruit orchards (average slope 3.1-12.2%) of the Lourens River catchment, South Africa, which specifically focused on the characteristics and attributes of buffer strips separating orchard areas from tributary streams. In addition, in-stream and erosion rill water samples were collected during three runoff events and GIS-based modeling was employed to predict losses of pesticides associated with runoff. The results show that erosion rills are common in buffer strips (on average 13 to 24 m wide) of the tributaries (up to 6.5 erosion rills per km flow length) and that erosion rills represent concentrated entry pathways of pesticide runoff into the tributaries during rainfall events. Exposure modeling shows that measured pesticide surface water concentrations correlated significantly (R(2)=0.626; p<0.001) with runoff losses predicted by the modeling approach in which buffer strip width was set to zero at sites with erosion rills; in contrast, no relationship between predicted runoff losses and in-stream pesticide concentrations were detected in the modeling approach that neglected erosion rills and thus assumed efficient buffer strips. Overall, the results of our study show that erosion rills may substantially reduce buffer strip pesticide retention efficacies during runoff events and suggest that the capability of buffer strips as a risk mitigation tool for runoff is largely overestimated in current regulatory risk assessment procedures conducted for pesticide authorization. Copyright © 2015 Elsevier B.V. All rights reserved.

Development and application of novelty pretreatment method for the concurrent quantitation of eleven water-soluble B vitamins in ultrafiltrates after renal replacement therapy.

PubMed

Wirkus, Dorota; Jakubus, Aleksandra; Owczuk, Radosław; Stepnowski, Piotr; Paszkiewicz, Monika

2017-02-01

Continous renal replacement therapy (CRRT) is particularly recommended for septic shock patients in intensive care units. The CRRT technique used most frequently is high volume continuous veno-venous haemofiltration. It provides a high rate of clearance of uremic toxins and inflammatory cytokines. However, it should also be taken into account that substances important for homeostasis may be concurrently unintentionally removed. Accordingly, water-soluble vitamins can be removed during continuous renal replacement therapy, and the estimate of the loss is critical to ensure appropriate supplementation. The aim of this work was to develop a simple methodology for a purification step prior to the LC-MS/MS determination of water-soluble vitamins in ultrafiltrate samples. For this purpose, two types of resin and a mix of resins were used as sorbents for the purification step. Moreover, parameters such as the amount of resin and the extraction time were optimized. The LC-MS/MS method was developed and validated for final determination of 11 vitamins. The results demonstrated the high purification capability of DEAE Sephadex resin with recoveries between 65 and 101% for water-soluble vitamins from ultrafiltrate samples. An optimized method was applied to assess the loss of B-group vitamins in patients after 24h of renal replacement therapy. The loss of vitamins B2, B6 pyridoxamine, B6 pyridoxal, B7, B1, and B5 in ultrafiltrates was similar in all patients. In the native ultrafiltrates, vitamins B6 pyridoxine, B9 and B12 were not detected. Copyright © 2016 Elsevier B.V. All rights reserved.

40 CFR 63.1184 - What do I need to know about the design specifications, installation, and operation of a bag leak...

Code of Federal Regulations, 2010 CFR

2010-07-01

... design specifications, installation, and operation of a bag leak detection system? 63.1184 Section 63... bag leak detection system? A bag leak detection system must meet the following requirements: (a) The bag leak detection system must be certified by the manufacturer to be capable of detecting PM...

Bayesian methods for outliers detection in GNSS time series

NASA Astrophysics Data System (ADS)

Qianqian, Zhang; Qingming, Gui

2013-07-01

This article is concerned with the problem of detecting outliers in GNSS time series based on Bayesian statistical theory. Firstly, a new model is proposed to simultaneously detect different types of outliers based on the conception of introducing different types of classification variables corresponding to the different types of outliers; the problem of outlier detection is converted into the computation of the corresponding posterior probabilities, and the algorithm for computing the posterior probabilities based on standard Gibbs sampler is designed. Secondly, we analyze the reasons of masking and swamping about detecting patches of additive outliers intensively; an unmasking Bayesian method for detecting additive outlier patches is proposed based on an adaptive Gibbs sampler. Thirdly, the correctness of the theories and methods proposed above is illustrated by simulated data and then by analyzing real GNSS observations, such as cycle slips detection in carrier phase data. Examples illustrate that the Bayesian methods for outliers detection in GNSS time series proposed by this paper are not only capable of detecting isolated outliers but also capable of detecting additive outlier patches. Furthermore, it can be successfully used to process cycle slips in phase data, which solves the problem of small cycle slips.

Mapping the Recent US Hurricanes Triggered Flood Events in Near Real Time

NASA Astrophysics Data System (ADS)

Shen, X.; Lazin, R.; Anagnostou, E. N.; Wanik, D. W.; Brakenridge, G. R.

2017-12-01

Synthetic Aperture Radar (SAR) observations is the only reliable remote sensing data source to map flood inundation during severe weather events. Unfortunately, since state-of-art data processing algorithms cannot meet the automation and quality standard of a near-real-time (NRT) system, quality controlled inundation mapping by SAR currently depends heavily on manual processing, which limits our capability to quickly issue flood inundation maps at global scale. Specifically, most SAR-based inundation mapping algorithms are not fully automated, while those that are automated exhibit severe over- and/or under-detection errors that limit their potential. These detection errors are primarily caused by the strong overlap among the SAR backscattering probability density functions (PDF) of different land cover types. In this study, we tested a newly developed NRT SAR-based inundation mapping system, named Radar Produced Inundation Diary (RAPID), using Sentinel-1 dual polarized SAR data over recent flood events caused by Hurricanes Harvey, Irma, and Maria (2017). The system consists of 1) self-optimized multi-threshold classification, 2) over-detection removal using land-cover information and change detection, 3) under-detection compensation, and 4) machine-learning based correction. Algorithm details are introduced in another poster, H53J-1603. Good agreements were obtained by comparing the result from RAPID with visual interpretation of SAR images and manual processing from Dartmouth Flood Observatory (DFO) (See Figure 1). Specifically, the over- and under-detections that is typically noted in automated methods is significantly reduced to negligible levels. This performance indicates that RAPID can address the automation and accuracy issues of current state-of-art algorithms and has the potential to apply operationally on a number of satellite SAR missions, such as SWOT, ALOS, Sentinel etc. RAPID data can support many applications such as rapid assessment of damage losses and disaster alleviation/rescue at global scale.

Insider Threat - Material Control and Accountability Mitigation

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

Powell, Danny H; Elwood Jr, Robert H; Roche, Charles T

2011-01-01

The technical objectives of nuclear safeguards are (1) the timely detection of diversion of significant quantities of nuclear material from peaceful uses to the manufacture of nuclear weapons or other nuclear explosive devices or for purposes unknown and (2) the deterrence of such diversion by the risk of early detection. The safeguards and security program must address both outsider threats and insider threats. Outsider threats are primarily addressed by the physical protection system. Insider threats can be any level of personnel at the site including passive or active insiders that could attempt protracted or abrupt diversion. This could occur bymore » an individual acting alone or by collusion between an individual with material control and accountability (MC&A) responsibilities and another individual who has responsibility or control within both the physical protection and the MC&A systems. The insider threat is one that must be understood and incorporated into the safeguards posture. There have been more than 18 documented cases of theft or loss of plutonium or highly enriched uranium. The insider has access, authority, and knowledge, as well as a set of attributes, that make him/her difficult to detect. An integrated safeguards program is designed as a defense-in-depth system that seeks to prevent the unauthorized removal of nuclear material, to provide early detection of any unauthorized attempt to remove nuclear material, and to rapidly respond to any attempted removal of nuclear material. The program is also designed to support protection against sabotage, espionage, unauthorized access, compromise, and other hostile acts that may cause unacceptable adverse impacts on national security, program continuity, the health and safety of employees, the public, or the environment. Nuclear MC&A play an essential role in the capabilities of an integrated safeguards system to deter and detect theft or diversion of nuclear material. An integrated safeguards system with compensating mitigation can decrease the risk of an insider performing a malicious act without detection.« less

Insulation board and process of making

DOEpatents

Nowobilski, J.J.; Owens, W.J.

1985-08-27

Insulation board is described which is capable of bearing a load without significant loss of insulating capacity due to compression, produced by a method wherein the board is made in compliance with specified conditions of time, temperature and pressure. 2 figs.

Aggressive periodontitis: case definition and diagnostic criteria.

PubMed

Albandar, Jasim M

2014-06-01

Aggressive periodontitis is a destructive disease characterized by the following: the involvement of multiple teeth with a distinctive pattern of periodontal tissue loss; a high rate of disease progression; an early age of onset; and the absence of systemic diseases. In some patients periodontal tissue loss may commence before puberty, whereas in most patients the age of onset is during or somewhat after the circumpubertal period. Besides infection with specific microorganisms, a host predisposition seems to play a key role in the pathogenesis of aggressive periodontitis, as evidenced by the familial aggregation of the disease. In this article we review the historical background of the diagnostic criteria of aggressive periodontitis, present a contemporary case definition and describe the clinical parameters of the disease. At present, the diagnosis of aggressive periodontitis is achieved using case history, clinical examination and radiographic evaluation. The data gathered using these methods are prone to relatively high measurement errors. Besides, this diagnostic approach measures past disease history and may not reliably measure existing disease activity or accurately predict future tissue loss. A diagnosis is often made years after the onset of the disease, partly because current assessment methods detect established disease more readily and reliably than they detect incipient or initial lesions where the tissue loss is minimal and usually below the detection threshold of present examination methods. Future advancements in understanding the pathogenesis of this disease may contribute to an earlier diagnosis. Insofar, future case definitions may involve the identification of key etiologic and risk factors, combined with high-precision methodologies that enable the early detection of initial lesions. This may significantly enhance the predictive value of these tests and detect cases of aggressive periodontitis before significant tissue loss develops. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Probablilistic evaluation of earthquake detection and location capability for Illinois, Indiana, Kentucky, Ohio, and West Virginia

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

Mauk, F.J.; Christensen, D.H.

1980-09-01

Probabilistic estimations of earthquake detection and location capabilities for the states of Illinois, Indiana, Kentucky, Ohio and West Virginia are presented in this document. The algorithm used in these epicentrality and minimum-magnitude estimations is a version of the program NETWORTH by Wirth, Blandford, and Husted (DARPA Order No. 2551, 1978) which was modified for local array evaluation at the University of Michigan Seismological Observatory. Estimations of earthquake detection capability for the years 1970 and 1980 are presented in four regional minimum m/sub b/ magnitude contour maps. Regional 90% confidence error ellipsoids are included for m/sub b/ magnitude events from 2.0more » through 5.0 at 0.5 m/sub b/ unit increments. The close agreement between these predicted epicentral 90% confidence estimates and the calculated error ellipses associated with actual earthquakes within the studied region suggest that these error determinations can be used to estimate the reliability of epicenter location. 8 refs., 14 figs., 2 tabs.« less

Chemical Detection and Identification Techniques for Exobiology Flight Experiments

NASA Technical Reports Server (NTRS)

Kojiro, Daniel R.; Sheverev, Valery A.; Khromov, Nikolai A.

2002-01-01

Exobiology flight experiments require highly sensitive instrumentation for in situ analysis of the volatile chemical species that occur in the atmospheres and surfaces of various bodies within the solar system. The complex mixtures encountered place a heavy burden on the analytical Instrumentation to detect and identify all species present. The minimal resources available onboard for such missions mandate that the instruments provide maximum analytical capabilities with minimal requirements of volume, weight and consumables. Advances in technology may be achieved by increasing the amount of information acquired by a given technique with greater analytical capabilities and miniaturization of proven terrestrial technology. We describe here methods to develop analytical instruments for the detection and identification of a wide range of chemical species using Gas Chromatography. These efforts to expand the analytical capabilities of GC technology are focused on the development of detectors for the GC which provide sample identification independent of the GC retention time data. A novel new approach employs Penning Ionization Electron Spectroscopy (PIES).

Wake Vortex Tangential Velocity Adaptive Spectral (TVAS) algorithm for pulsed Lidar systems.

DOT National Transportation Integrated Search

2011-06-20

In 2008 the FAA tasked the Volpe Center with the development of a government owned processing package capable of performing wake detection, characterization and tracking. : The current paper presents the background, progress, and capabilities to date...

Performance analysis of a multispectral system for mine detection in the littoral zone

NASA Astrophysics Data System (ADS)

Hargrove, John T.; Louchard, Eric

2004-09-01

Science & Technology International (STI) has developed, under contract with the Office of Naval Research, a system of multispectral airborne sensors and processing algorithms capable of detecting mine-like objects in the surf zone. STI has used this system to detect mine-like objects in a littoral environment as part of blind tests at Kaneohe Marine Corps Base Hawaii, and Panama City, Florida. The airborne and ground subsystems are described. The detection algorithm is graphically illustrated. We report on the performance of the system configured to operate without a human in the loop. A subsurface (underwater bottom proud mine in the surf zone and moored mine in shallow water) mine detection capability is demonstrated in the surf zone, and in shallow water with wave spillage and foam. Our analysis demonstrates that this STI-developed multispectral airborne mine detection system provides a technical foundation for a viable mine counter-measures system for use prior to an amphibious assault.

Building a Predictive Capability for Decision-Making that Supports MultiPEM

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

Carmichael, Joshua Daniel

Multi-phenomenological explosion monitoring (multiPEM) is a developing science that uses multiple geophysical signatures of explosions to better identify and characterize their sources. MultiPEM researchers seek to integrate explosion signatures together to provide stronger detection, parameter estimation, or screening capabilities between different sources or processes. This talk will address forming a predictive capability for screening waveform explosion signatures to support multiPEM.

A physics investigation of deadtime losses in neutron counting at low rates with Cf252

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

Evans, Louise G; Croft, Stephen

2009-01-01

{sup 252}Cf spontaneous fission sources are used for the characterization of neutron counters and the determination of calibration parameters; including both neutron coincidence counting (NCC) and neutron multiplicity deadtime (DT) parameters. Even at low event rates, temporally-correlated neutron counting using {sup 252}Cf suffers a deadtime effect. Meaning that in contrast to counting a random neutron source (e.g. AmLi to a close approximation), DT losses do not vanish in the low rate limit. This is because neutrons are emitted from spontaneous fission events in time-correlated 'bursts', and are detected over a short period commensurate with their lifetime in the detector (characterizedmore » by the system die-away time, {tau}). Thus, even when detected neutron events from different spontaneous fissions are unlikely to overlap in time, neutron events within the detected 'burst' are subject to intrinsic DT losses. Intrinsic DT losses for dilute Pu will be lower since the multiplicity distribution is softer, but real items also experience self-multiplication which can increase the 'size' of the bursts. Traditional NCC DT correction methods do not include the intrinsic (within burst) losses. We have proposed new forms of the traditional NCC Singles and Doubles DT correction factors. In this work, we apply Monte Carlo neutron pulse train analysis to investigate the functional form of the deadtime correction factors for an updating deadtime. Modeling is based on a high efficiency {sup 3}He neutron counter with short die-away time, representing an ideal {sup 3}He based detection system. The physics of dead time losses at low rates is explored and presented. It is observed that new forms are applicable and offer more accurate correction than the traditional forms.« less