A Method Based on Wavelet Transforms for Source Detection in Photon-counting Detector Images. II. Application to ROSAT PSPC Images

NASA Astrophysics Data System (ADS)

Damiani, F.; Maggio, A.; Micela, G.; Sciortino, S.

1997-07-01

We apply to the specific case of images taken with the ROSAT PSPC detector our wavelet-based X-ray source detection algorithm presented in a companion paper. Such images are characterized by the presence of detector ``ribs,'' strongly varying point-spread function, and vignetting, so that their analysis provides a challenge for any detection algorithm. First, we apply the algorithm to simulated images of a flat background, as seen with the PSPC, in order to calibrate the number of spurious detections as a function of significance threshold and to ascertain that the spatial distribution of spurious detections is uniform, i.e., unaffected by the ribs; this goal was achieved using the exposure map in the detection procedure. Then, we analyze simulations of PSPC images with a realistic number of point sources; the results are used to determine the efficiency of source detection and the accuracy of output quantities such as source count rate, size, and position, upon a comparison with input source data. It turns out that sources with 10 photons or less may be confidently detected near the image center in medium-length (~104 s), background-limited PSPC exposures. The positions of sources detected near the image center (off-axis angles < 15') are accurate to within a few arcseconds. Output count rates and sizes are in agreement with the input quantities, within a factor of 2 in 90% of the cases. The errors on position, count rate, and size increase with off-axis angle and for detections of lower significance. We have also checked that the upper limits computed with our method are consistent with the count rates of undetected input sources. Finally, we have tested the algorithm by applying it on various actual PSPC images, among the most challenging for automated detection procedures (crowded fields, extended sources, and nonuniform diffuse emission). The performance of our method in these images is satisfactory and outperforms those of other current X-ray detection techniques, such as those employed to produce the MPE and WGA catalogs of PSPC sources, in terms of both detection reliability and efficiency. We have also investigated the theoretical limit for point-source detection, with the result that even sources with only 2-3 photons may be reliably detected using an efficient method in images with sufficiently high resolution and low background.

High resolution time interval meter

DOEpatents

Martin, A.D.

1986-05-09

Method and apparatus are provided for measuring the time interval between two events to a higher resolution than reliability available from conventional circuits and component. An internal clock pulse is provided at a frequency compatible with conventional component operating frequencies for reliable operation. Lumped constant delay circuits are provided for generating outputs at delay intervals corresponding to the desired high resolution. An initiation START pulse is input to generate first high resolution data. A termination STOP pulse is input to generate second high resolution data. Internal counters count at the low frequency internal clock pulse rate between the START and STOP pulses. The first and second high resolution data are logically combined to directly provide high resolution data to one counter and correct the count in the low resolution counter to obtain a high resolution time interval measurement.

Roles for Coincidence Detection in Coding Amplitude-Modulated Sounds

PubMed Central

Ashida, Go; Kretzberg, Jutta; Tollin, Daniel J.

2016-01-01

Many sensory neurons encode temporal information by detecting coincident arrivals of synaptic inputs. In the mammalian auditory brainstem, binaural neurons of the medial superior olive (MSO) are known to act as coincidence detectors, whereas in the lateral superior olive (LSO) roles of coincidence detection have remained unclear. LSO neurons receive excitatory and inhibitory inputs driven by ipsilateral and contralateral acoustic stimuli, respectively, and vary their output spike rates according to interaural level differences. In addition, LSO neurons are also sensitive to binaural phase differences of low-frequency tones and envelopes of amplitude-modulated (AM) sounds. Previous physiological recordings in vivo found considerable variations in monaural AM-tuning across neurons. To investigate the underlying mechanisms of the observed temporal tuning properties of LSO and their sources of variability, we used a simple coincidence counting model and examined how specific parameters of coincidence detection affect monaural and binaural AM coding. Spike rates and phase-locking of evoked excitatory and spontaneous inhibitory inputs had only minor effects on LSO output to monaural AM inputs. In contrast, the coincidence threshold of the model neuron affected both the overall spike rates and the half-peak positions of the AM-tuning curve, whereas the width of the coincidence window merely influenced the output spike rates. The duration of the refractory period affected only the low-frequency portion of the monaural AM-tuning curve. Unlike monaural AM coding, temporal factors, such as the coincidence window and the effective duration of inhibition, played a major role in determining the trough positions of simulated binaural phase-response curves. In addition, empirically-observed level-dependence of binaural phase-coding was reproduced in the framework of our minimalistic coincidence counting model. These modeling results suggest that coincidence detection of excitatory and inhibitory synaptic inputs is essential for LSO neurons to encode both monaural and binaural AM sounds. PMID:27322612

A photon-counting photodiode array detector for far ultraviolet (FUV) astronomy

NASA Technical Reports Server (NTRS)

Hartig, G. F.; Moos, H. W.; Pembroke, R.; Bowers, C.

1982-01-01

A compact, stable, single-stage intensified photodiode array detector designed for photon-counting, far ultraviolet astronomy applications employs a saturable, 'C'-type MCP (Galileo S. MCP 25-25) to produce high gain pulses with a narrowly peaked pulse height distribution. The P-20 output phosphor exhibits a very short decay time, due to the high current density of the electron pulses. This intensifier is being coupled to a self-scanning linear photodiode array which has a fiber optic input window which allows direct, rigid mechanical coupling with minimal light loss. The array was scanned at a 250 KHz pixel rate. The detector exhibits more than adequate signal-to-noise ratio for pulse counting and event location.

Portable multiplicity counter

DOEpatents

Newell, Matthew R [Los Alamos, NM; Jones, David Carl [Los Alamos, NM

2009-09-01

A portable multiplicity counter has signal input circuitry, processing circuitry and a user/computer interface disposed in a housing. The processing circuitry, which can comprise a microcontroller integrated circuit operably coupled to shift register circuitry implemented in a field programmable gate array, is configured to be operable via the user/computer interface to count input signal pluses receivable at said signal input circuitry and record time correlations thereof in a total counting mode, coincidence counting mode and/or a multiplicity counting mode. The user/computer interface can be for example an LCD display/keypad and/or a USB interface. The counter can include a battery pack for powering the counter and low/high voltage power supplies for biasing external detectors so that the counter can be configured as a hand-held device for counting neutron events.

Method and means for generating a synchronizing pulse from a repetitive wave of varying frequency

DOEpatents

DeVolpi, Alexander; Pecina, Ronald J.; Travis, Dale J.

1976-01-01

An event that occurs repetitively at continuously changing frequencies can be used to generate a triggering pulse which is used to synchronize or control. The triggering pulse is generated at a predetermined percentage of the period of the repetitive waveform without regard to frequency. Counts are accumulated in two counters, the first counting during the "on" fraction of the period, and the second counting during the "off" fraction. The counts accumulated during each cycle are compared. On equality the trigger pulse is generated. Count input rates to each counter are determined by the ratio of the on-off fractions of the event waveform and the desired phase relationship. This invention is of particular utility in providing a trigger or synchronizing pulse during the open period of the shutter of a high-speed framing camera during its acceleration as well as its period of substantially constant speed.

CLARO: an ASIC for high rate single photon counting with multi-anode photomultipliers

NASA Astrophysics Data System (ADS)

Baszczyk, M.; Carniti, P.; Cassina, L.; Cotta Ramusino, A.; Dorosz, P.; Fiorini, M.; Gotti, C.; Kucewicz, W.; Malaguti, R.; Pessina, G.

2017-08-01

The CLARO is a radiation-hard 8-channel ASIC designed for single photon counting with multi-anode photomultiplier tubes. Each channel outputs a digital pulse when the input signal from the photomultiplier crosses a configurable threshold. The fast return to baseline, typically within 25 ns, and below 50 ns in all conditions, allows to count up to 107 hits/s on each channel, with a power consumption of about 1 mW per channel. The ASIC presented here is a much improved version of the first 4-channel prototype. The threshold can be precisely set in a wide range, between 30 ke- (5 fC) and 16 Me- (2.6 pC). The noise of the amplifier with a 10 pF input capacitance is 3.5 ke- (0.6 fC) RMS. All settings are stored in a 128-bit configuration and status register, protected against soft errors with triple modular redundancy. The paper describes the design of the ASIC at transistor-level, and demonstrates its performance on the test bench.

Does Facial Expressivity Count? How Typically Developing Children Respond Initially to Children with Autism

ERIC Educational Resources Information Center

Stagg, Steven D.; Slavny, Rachel; Hand, Charlotte; Cardoso, Alice; Smith, Pamela

2014-01-01

Research investigating expressivity in children with autism spectrum disorder has reported flat affect or bizarre facial expressivity within this population; however, the impact expressivity may have on first impression formation has received little research input. We examined how videos of children with autism spectrum disorder were rated for…

Estimation of Enterococci Input from Bathers and Animals on A Recreational Beach Using Camera Images

PubMed Central

D, Wang John; M, Solo-Gabriele Helena; M, Abdelzaher Amir; E, Fleming Lora

2010-01-01

Enterococci, are used nationwide as a water quality indicator of marine recreational beaches. Prior research has demonstrated that enterococci inputs to the study beach site (located in Miami, FL) are dominated by non-point sources (including humans and animals). We have estimated their respective source functions by developing a counting methodology for individuals to better understand their non-point source load impacts. The method utilizes camera images of the beach taken at regular time intervals to determine the number of people and animal visitors. The developed method translates raw image counts for weekdays and weekend days into daily and monthly visitation rates. Enterococci source functions were computed from the observed number of unique individuals for average days of each month of the year, and from average load contributions for humans and for animals. Results indicate that dogs represent the larger source of enterococci relative to humans and birds. PMID:20381094

Photon counting photodiode array detector for far ultraviolet (FUV) astronomy

NASA Technical Reports Server (NTRS)

Hartig, G. F.; Moos, H. W.; Pembroke, R.; Bowers, C.

1982-01-01

A compact, stable, single-stage intensified photodiode array detector designed for photon-counting, far ultraviolet astronomy applications employs a saturable, 'C'-type MCP (Galileo S. MCP 25-25) to produce high gain pulses with a narrowly peaked pulse height distribution. The P-20 output phosphor exhibits a very short decay time, due to the high current density of the electron pulses. This intensifier is being coupled to a self-scanning linear photodiode array which has a fiber optic input window which allows direct, rigid mechanical coupling with minimal light loss. The array was scanned at a 250 KHz pixel rate. The detector exhibits more than adequate signal-to-noise ratio for pulse counting and event location. Previously announced in STAR as N82-19118

Nitrogen fixation in biological soil crusts from southeast Utah, USA

USGS Publications Warehouse

Belnap, Jayne

2002-01-01

Biological soil crusts can be the dominant source of N for arid land ecosystems. We measured potential N fixation rates biweekly for 2 years, using three types of soil crusts: (1) crusts whose directly counted cells were >98% Microcoleus vaginatus (light crusts); (2) crusts dominated by M. vaginatus, but with 20% or more of the directly counted cells represented by Nostoc commune and Scytonema myochrous (dark crusts); and (3) the soil lichen Collema sp. At all observation times, Collema had higher nitrogenase activity (NA) than dark crusts, which had higher NA than light crusts, indicating that species composition is critical when estimating N inputs. In addition, all three types of crusts generally responded in a similar fashion to climate conditions. Without precipitation within a week of collection, no NA was recorded, regardless of other conditions being favorable. Low (<1°C) and high (>26°C) temperatures precluded NA, even if soils were moist. If rain or snow melt had occurred 3 or less days before collection, NA levels were highly correlated with daily average temperatures of the previous 3 days (r2=0.93 for Collema crusts; r2=0.86 for dark crusts and r2=0.83 for light crusts) for temperatures between 1°C and 26°C. If a precipitation event followed a long dry period, NA levels were lower than if collection followed a time when soils were wet for extended periods (e.g., winter). Using a combination of data from a recording weather datalogger, time-domain reflectometry, manual dry-down curves, and N fixation rates at different temperatures, annual N input from the different crust types was estimated. Annual N input from dark crusts found at relatively undisturbed sites was estimated at 9 kg ha–1 year–1. With 20% cover of the N-fixing soil lichen Collema, inputs are estimated at 13 kg ha–1 year–1. N input from light crusts, generally indicating soil surface disturbance, was estimated at 1.4 kg ha–1 year–1. The rates in light crusts are expected to be highly variable, as disturbance history will determine cyanobacterial biomass and therefore N fixation rates.

Inspection Methods in Programming.

DTIC Science & Technology

1981-06-01

Counting is a a specialization of Iterative-generation in which the generating function is Oneplus ) Waters’ second category of plan building method...is Oneplus and the initial input is 1. 0 I 180 CHAPTER NINE -ta a acio f igr9-.IeaieGnrtoPln 7 -7 STEADY STATE PLANS 181 TemporalPlan counting...specializalion iterative-generation roles .action(afu nction) ,tail(counting) conslraints .action.op = oneplus A .action.input = 1 The lItcrative-application

DIRECT COUPLED PROGRESSIVE STAGE PULSE COUNTER APPARATUS

DOEpatents

Kaufman, W.M.

1962-08-14

A progressive electrical pulse counter circuit was designed for the counting of a chain of input pulses of random width and/or frequency. The circuit employs an odd and even pulse input line alternately connected to a series of directly connected bistable counting stages. Each bistable stage has two d-c operative states which stage, when in its rnrtial state, prevents the next succeeding stage from changing its condition when the latter stage is pulsed. Since only altennate stages are pulsed for each incoming pulse, only one stage will change its state for each input pulse thereby providing prog essive stage by stage counting. (AEC)

A matrix-inversion method for gamma-source mapping from gamma-count data

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

Adsley, Ian; Burgess, Claire; Bull, Richard K

In a previous paper it was proposed that a simple matrix inversion method could be used to extract source distributions from gamma-count maps, using simple models to calculate the response matrix. The method was tested using numerically generated count maps. In the present work a 100 kBq Co{sup 60} source has been placed on a gridded surface and the count rate measured using a NaI scintillation detector. The resulting map of gamma counts was used as input to the matrix inversion procedure and the source position recovered. A multi-source array was simulated by superposition of several single-source count maps andmore » the source distribution was again recovered using matrix inversion. The measurements were performed for several detector heights. The effects of uncertainties in source-detector distances on the matrix inversion method are also examined. The results from this work give confidence in the application of the method to practical applications, such as the segregation of highly active objects amongst fuel-element debris. (authors)« less

Conversion of Phase Information into a Spike-Count Code by Bursting Neurons

PubMed Central

Samengo, Inés; Montemurro, Marcelo A.

2010-01-01

Single neurons in the cerebral cortex are immersed in a fluctuating electric field, the local field potential (LFP), which mainly originates from synchronous synaptic input into the local neural neighborhood. As shown by recent studies in visual and auditory cortices, the angular phase of the LFP at the time of spike generation adds significant extra information about the external world, beyond the one contained in the firing rate alone. However, no biologically plausible mechanism has yet been suggested that allows downstream neurons to infer the phase of the LFP at the soma of their pre-synaptic afferents. Therefore, so far there is no evidence that the nervous system can process phase information. Here we study a model of a bursting pyramidal neuron, driven by a time-dependent stimulus. We show that the number of spikes per burst varies systematically with the phase of the fluctuating input at the time of burst onset. The mapping between input phase and number of spikes per burst is a robust response feature for a broad range of stimulus statistics. Our results suggest that cortical bursting neurons could play a crucial role in translating LFP phase information into an easily decodable spike count code. PMID:20300632

ELECTRICAL PULSE COUNTER APPARATUS

DOEpatents

Kaufman, W.M.; Jeeves, T.A.

1962-09-01

A progressive electrical pulse counter circuit rs designed for the counting of a chain of input pulses. The circuit employs a series of direct connected bistable counting stages simultaneously pulsed by each input pulse and a delay means connected between each of the stages. Each bistable stage has two d-c operative states, which stage, when in its initial state, prevents the next succeeding stage from changing its condition when the latter stage is pulsed. Since the delay circuits between the stages prevents the immediate decay of the d-c state of each stage when the stages are pulsed, only one stage will change its state for each input pulse, thereby providing progressive stage-by-stage counting. (AEC)

Fast and High Dynamic Range Imaging with Superconducting Tunnel Junction Detectors

NASA Astrophysics Data System (ADS)

Matsuo, Hiroshi

2014-08-01

We have demonstrated a combined test of the submillimeter-wave SIS photon detectors and GaAs-JFET cryogenic integrated circuits. A relatively large background photo-current can be read out by fast-reset integrating amplifiers. An integration time of 1 ms enables fast frame rate readout and large dynamic range imaging, with an expected dynamic range of 8,000 in 1 ms. Ultimate fast and high dynamic range performance of superconducting tunnel junction detectors (STJ) will be obtained when photon counting capabilities are employed. In the terahertz frequencies, when input photon rate of 100 MHz is measured, the photon bunching gives us enough timing resolution to be used as phase information of intensity fluctuation. Application of photon statistics will be a new tool in the terahertz frequency region. The design parameters of STJ terahertz photon counting detectors are discussed.

Low cost digital electronics for isotope analysis with microcalorimeters - final report

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

W. Hennig

2006-09-11

The overall goal of the Phase I research was to demonstrate that the digital readout electronics and filter algorithms developed by XIA for use with HPGe detectors can be adapted to high precision, cryogenic gamma detectors (microcalorimeters) and not only match the current state of the art in terms of energy resolution, but do so at a significantly reduced cost. This would make it economically feasible to instrument large arrays of microcalorimeters and would also allow automation of the setup, calibration and operation of large numbers of channels through software. We expected, and have demonstrated, that this approach would furthermore » allow much higher count rates than the optimum filter algorithms currently used. In particular, in measurements with a microcalorimeter at LLNL, the adapted Pixie-16 spectrometer achieved an energy resolution of 0.062%, significantly better than the targeted resolution of 0.1% in the Phase I proposal and easily matching resolutions obtained with LLNL readout electronics and optimum filtering (0.066%). The theoretical maximum output count rate for the filter settings used to achieve this resolution is about 120cps. If the filter is adjusted for maximum throughput with an energy resolution of 0.1% or better, rates of 260cps are possible. This is 20-50 times higher than the maximum count rates of about 5cps with optimum filters for this detector. While microcalorimeter measurements were limited to count rates of ~1.3cps due to the strength of available sources, pulser measurements demonstrated that measured energy resolutions were independent of counting rate to output counting rates well in excess of 200cps or more.. We also developed a preliminary hardware design of a spectrometer module, consisting of a digital processing core and several input options that can be implemented on daughter boards. Depending upon the daughter board, the total parts cost per channel ranged between $12 and $27, resulting in projected product prices of $80 to $160 per channel. This demonstrates that a price of $100 per channel is economically very feasible for large microcalorimeter arrays.« less

STDP allows fast rate-modulated coding with Poisson-like spike trains.

PubMed

Gilson, Matthieu; Masquelier, Timothée; Hugues, Etienne

2011-10-01

Spike timing-dependent plasticity (STDP) has been shown to enable single neurons to detect repeatedly presented spatiotemporal spike patterns. This holds even when such patterns are embedded in equally dense random spiking activity, that is, in the absence of external reference times such as a stimulus onset. Here we demonstrate, both analytically and numerically, that STDP can also learn repeating rate-modulated patterns, which have received more experimental evidence, for example, through post-stimulus time histograms (PSTHs). Each input spike train is generated from a rate function using a stochastic sampling mechanism, chosen to be an inhomogeneous Poisson process here. Learning is feasible provided significant covarying rate modulations occur within the typical timescale of STDP (~10-20 ms) for sufficiently many inputs (~100 among 1000 in our simulations), a condition that is met by many experimental PSTHs. Repeated pattern presentations induce spike-time correlations that are captured by STDP. Despite imprecise input spike times and even variable spike counts, a single trained neuron robustly detects the pattern just a few milliseconds after its presentation. Therefore, temporal imprecision and Poisson-like firing variability are not an obstacle to fast temporal coding. STDP provides an appealing mechanism to learn such rate patterns, which, beyond sensory processing, may also be involved in many cognitive tasks.

STDP Allows Fast Rate-Modulated Coding with Poisson-Like Spike Trains

PubMed Central

Hugues, Etienne

2011-01-01

Spike timing-dependent plasticity (STDP) has been shown to enable single neurons to detect repeatedly presented spatiotemporal spike patterns. This holds even when such patterns are embedded in equally dense random spiking activity, that is, in the absence of external reference times such as a stimulus onset. Here we demonstrate, both analytically and numerically, that STDP can also learn repeating rate-modulated patterns, which have received more experimental evidence, for example, through post-stimulus time histograms (PSTHs). Each input spike train is generated from a rate function using a stochastic sampling mechanism, chosen to be an inhomogeneous Poisson process here. Learning is feasible provided significant covarying rate modulations occur within the typical timescale of STDP (∼10–20 ms) for sufficiently many inputs (∼100 among 1000 in our simulations), a condition that is met by many experimental PSTHs. Repeated pattern presentations induce spike-time correlations that are captured by STDP. Despite imprecise input spike times and even variable spike counts, a single trained neuron robustly detects the pattern just a few milliseconds after its presentation. Therefore, temporal imprecision and Poisson-like firing variability are not an obstacle to fast temporal coding. STDP provides an appealing mechanism to learn such rate patterns, which, beyond sensory processing, may also be involved in many cognitive tasks. PMID:22046113

Spent Fuel Assay with an Ultra-High Rate HPGe Spectrometer

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

Fast, James; Fulsom, Bryan; Pitts, Karl

2015-07-01

Traditional verification of spent nuclear fuel (SNF) includes determination of initial enrichment, burnup and cool down time (IE, BU, CT). Along with neutron measurements, passive gamma assay provides important information for determining BU and CT. Other gamma-ray-based assay methods such as passive tomography and active delayed gamma offer the potential to measure the spatial distribution of fission products and the fissile isotopic concentration of the fuel, respectively. All fuel verification methods involving gamma-ray spectroscopy require that the spectrometers manage very high count rates while extracting the signatures of interest. PNNL has developed new digital filtering and analysis techniques to producemore » an ultra-high rate gamma-ray spectrometer from a standard coaxial high-purity germanium (HPGe) crystal. This 37% relative efficiency detector has been operated for SNF measurements at input count rates of 500-1300 kcps and throughput in excess of 150 kcps. Optimized filtering algorithms preserve the spectroscopic capability of the system even at these high rates. This paper will present the results of both passive and active SNF measurement performed with this system at PNNL. (authors)« less

Could Early Antiretroviral Therapy Entail More Risks than Benefits in sub-Saharan African HIV-Infected Adults? A Model-Based Analysis

PubMed Central

Anglaret, Xavier; Scott, Callie A.; Walensky, Rochelle P.; Ouattara, Eric; Losina, Elena; Moh, Raoul; Becker, Jessica E.; Uhler, Lauren; Danel, Christine; Messou, Eugene; Eholié, Serge; Freedberg, Kenneth A.

2013-01-01

Background Initiation of antiretroviral therapy (ART) in all HIV-infected adults, regardless of count, is a proposed strategy for reducing HIV transmission. We investigated the conditions under which starting ART early could entail more risks than benefits for patients with high CD4 counts. Methods We used a simulation model to compare ART initiation upon entry to care (“immediate ART”) to initiation at CD4 ≤350 cells/μL (“WHO 2010 ART”) in African adults with CD4 counts >500 cells/μL. We varied inputs to determine the combination of parameters (population characteristics, conditions of care, treatment outcomes) that would result in higher 15-year mortality with immediate ART. Results Fifteen-year mortality was 56.7% for WHO 2010 and 51.8% for immediate ART. In one-way sensitivity analysis, lower 15-year mortality was consistently achieved with immediate ART unless the rate of fatal ART toxicity was >1.0/100PY, the rate of withdrawal from care was >1.2-fold higher or the rate of ART failure due to poor adherence was >4.3-fold higher on immediate ART. In multi-way sensitivity analysis, immediate ART led to higher mortality when moderate rates of fatal ART toxicity (0.25/100PY) were combined with rates of withdrawal from care >1.1-fold higher and rates of treatment failure >2.1-fold higher on immediate ART than on WHO 2010 ART. Conclusions In sub-Saharan Africa, ART initiation at entry into care would improve long-term survival of patients with high CD4 counts, unless it is associated with increased withdrawal from care and decreased adherence. In early ART trials, a focus on retention and adherence will be critical. PMID:22809695

On the frequency response of a Wenglor particle-counting system for aeolian transport measurements

NASA Astrophysics Data System (ADS)

Bauer, Bernard O.; Davidson-Arnott, Robin G. D.; Hilton, Michael J.; Fraser, Douglas

2018-06-01

A commonly deployed particle-counting system for aeolian saltation flux, consisting of a Wenglor fork sensor and an Onset Hobo Pulse Input Adapter linked to an Onset Hobo Energy Logger Pro data logger, was tested for frequency response. The Wenglor fork sensor is an optical gate device that has very fast switching capacity that can accommodate the time of flight of saltating sand particles through the sensing volume with the exception of very fine sand or silt and very quickly moving particles. The Pulse Input Adapter, in contrast, imposes limitations on the frequency response of the system. The manufacturer of the pulse adapter specifies an upper limit of 120 Hz, although bench tests with an electronic pulse generator indicate that the frequency response of the Pulse Input Adapter, in isolation, is excellent up to 3000 Hz, with only small error (less than 1.6%) due to under-counting during data transfer intervals. A mechanical test of the integrated system (fork sensor, pulse input adapter, and data logger) demonstrates excellent performance up to about 700 Hz (less than 2% error), but significant under-counting above 1000 Hz for unknown reasons. This specific particle-counting system therefore has a frequency response that is well suited for investigation of the dynamics of aeolian saltation as typically encountered in most field conditions on coastal beaches with the exception of extreme wind events and very small particle sizes.

Effect of a dual inlet channel on cell loading in microfluidics.

PubMed

Yun, Hoyoung; Kim, Kisoo; Lee, Won Gu

2014-11-01

Unwanted sedimentation and attachment of a number of cells onto the bottom channel often occur on relatively large-scale inlets of conventional microfluidic channels as a result of gravity and fluid shear. Phenomena such as sedimentation have become recognized problems that can be overcome by performing microfluidic experiments properly, such as by calculating a meaningful output efficiency with respect to real input. Here, we present a dual-inlet design method for reducing cell loss at the inlet of channels by adding a new " upstream inlet " to a single main inlet design. The simple addition of an upstream inlet can create a vertically layered sheath flow prior to the main inlet for cell loading. The bottom layer flow plays a critical role in preventing the cells from attaching to the bottom of the channel entrance, resulting in a low possibility of cell sedimentation at the main channel entrance. To provide proof-of-concept validation, we applied our design to a microfabricated flow cytometer system (μFCS) and compared the cell counting efficiency of the proposed μFCS with that of the previous single-inlet μFCS and conventional FCS. We used human white blood cells and fluorescent microspheres to quantitatively evaluate the rate of cell sedimentation in the main inlet and to measure fluorescence sensitivity at the detection zone of the flow cytometer microchip. Generating a sheath flow as the bottom layer was meaningfully used to reduce the depth of field as well as the relative deviation of targets in the z-direction (compared to the x-y flow plane), leading to an increased counting sensitivity of fluorescent detection signals. Counting results using fluorescent microspheres showed both a 40% reduction in the rate of sedimentation and a 2-fold higher sensitivity in comparison with the single-inlet μFCS. The results of CD4(+) T-cell counting also showed that the proposed design results in a 25% decrease in the rate of cell sedimentation and a 28% increase in sensitivity when compared to the single-inlet μFCS. This method is simple and easy to use in design, yet requires no additional time or cost in fabrication. Furthermore, we expect that this approach could potentially be helpful for calculating exact cell loading and counting efficiency for a small input number of cells, such as primary cells and rare cells, in microfluidic channel applications.

The AGS Ggamma Meter and Calibrating the Gauss Clock

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

Ahrens, Leif

2014-03-31

During AGS Polarized Proton acceleration periods, one output from the AGS Ggamma Meter, namely the energy (or Ggamma) calculated from the magnetic field in the AGS main magnets and the beam radius- both measured in particular instant, is used to figure out the times in the AGS magnet acceleration cycle when the beam passes through a particular set of depolarizing resonances. The resonance set occur whenever a particle’s Ggamma (energy*(G/m) becomes nearly equal to n*Qx (i.e. any integer multiplied by the horizontal betatron tune). This deliverable is why the machinery is referred to as the ''Ggamma Meter'' rather than themore » AGS energy meter. The Ggamma Meter takes as inputs a set of measurements of frequency (F(t)), radius (r(t)), and gauss clock counts (GCC(t)). The other energy (GgammaBr) assumes the field when the gauss clock starts counting is known. The change in field to time t is given by the measured accumulated gauss clock counts multiplied by the gauss clock calibration (gauss/GCC). In order to deal with experimental data, this calibration factor gets an added ad hoc complication, namely a correction dependent on the rate of change the counting rate. The Ggamma meter takes GCC(t) and together with the past history for this cycle calculates B(t).« less

Adjoint-Based Implicit Uncertainty Analysis for Figures of Merit in a Laser Inertial Fusion Engine

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

Seifried, J E; Fratoni, M; Kramer, K J

A primary purpose of computational models is to inform design decisions and, in order to make those decisions reliably, the confidence in the results of such models must be estimated. Monte Carlo neutron transport models are common tools for reactor designers. These types of models contain several sources of uncertainty that propagate onto the model predictions. Two uncertainties worthy of note are (1) experimental and evaluation uncertainties of nuclear data that inform all neutron transport models and (2) statistical counting precision, which all results of a Monte Carlo codes contain. Adjoint-based implicit uncertainty analyses allow for the consideration of anymore » number of uncertain input quantities and their effects upon the confidence of figures of merit with only a handful of forward and adjoint transport calculations. When considering a rich set of uncertain inputs, adjoint-based methods remain hundreds of times more computationally efficient than Direct Monte-Carlo methods. The LIFE (Laser Inertial Fusion Energy) engine is a concept being developed at Lawrence Livermore National Laboratory. Various options exist for the LIFE blanket, depending on the mission of the design. The depleted uranium hybrid LIFE blanket design strives to close the fission fuel cycle without enrichment or reprocessing, while simultaneously achieving high discharge burnups with reduced proliferation concerns. Neutron transport results that are central to the operation of the design are tritium production for fusion fuel, fission of fissile isotopes for energy multiplication, and production of fissile isotopes for sustained power. In previous work, explicit cross-sectional uncertainty analyses were performed for reaction rates related to the figures of merit for the depleted uranium hybrid LIFE blanket. Counting precision was also quantified for both the figures of merit themselves and the cross-sectional uncertainty estimates to gauge the validity of the analysis. All cross-sectional uncertainties were small (0.1-0.8%), bounded counting uncertainties, and were precise with regard to counting precision. Adjoint/importance distributions were generated for the same reaction rates. The current work leverages those adjoint distributions to transition from explicit sensitivities, in which the neutron flux is constrained, to implicit sensitivities, in which the neutron flux responds to input perturbations. This treatment vastly expands the set of data that contribute to uncertainties to produce larger, more physically accurate uncertainty estimates.« less

Optimizing microwave photodetection: input-output theory

NASA Astrophysics Data System (ADS)

Schöndorf, M.; Govia, L. C. G.; Vavilov, M. G.; McDermott, R.; Wilhelm, F. K.

2018-04-01

High fidelity microwave photon counting is an important tool for various areas from background radiation analysis in astronomy to the implementation of circuit quantum electrodynamic architectures for the realization of a scalable quantum information processor. In this work we describe a microwave photon counter coupled to a semi-infinite transmission line. We employ input-output theory to examine a continuously driven transmission line as well as traveling photon wave packets. Using analytic and numerical methods, we calculate the conditions on the system parameters necessary to optimize measurement and achieve high detection efficiency. With this we can derive a general matching condition depending on the different system rates, under which the measurement process is optimal.

How Parents Read Counting Books and Non-numerical Books to Their Preverbal Infants: An Observational Study.

PubMed

Goldstein, Alison; Cole, Thomas; Cordes, Sara

2016-01-01

Studies have stressed the importance of counting with children to promote formal numeracy abilities; however, little work has investigated when parents begin to engage in this behavior with their young children. In the current study, we investigated whether parents elaborated on numerical information when reading a counting book to their preverbal infants and whether developmental differences in numerical input exist even in the 1st year of life. Parents and their 5-10 months old infants were asked to read, as they would at home, two books to their infants: a counting book and another book that did not have numerical content. Parents' spontaneous statements rarely focused on number and those that did consisted primarily of counting, with little emphasis on labeling the cardinality of the set. However, developmental differences were observed even in this age range, such that parents were more likely to make numerical utterances when reading to older infants. Together, results are the first to characterize naturalistic reading behaviors between parents and their preverbal infants in the context of counting books, suggesting that although counting books promote numerical language in parents, infants still receive very little in the way of numerical input before the end of the 1st year of life. While little is known regarding the impact of number talk on the cognitive development of young infants, the current results may guide future work in this area by providing the first assessment of the characteristics of parental numerical input to preverbal infants.

High-rate dead-time corrections in a general purpose digital pulse processing system

PubMed Central

Abbene, Leonardo; Gerardi, Gaetano

2015-01-01

Dead-time losses are well recognized and studied drawbacks in counting and spectroscopic systems. In this work the abilities on dead-time correction of a real-time digital pulse processing (DPP) system for high-rate high-resolution radiation measurements are presented. The DPP system, through a fast and slow analysis of the output waveform from radiation detectors, is able to perform multi-parameter analysis (arrival time, pulse width, pulse height, pulse shape, etc.) at high input counting rates (ICRs), allowing accurate counting loss corrections even for variable or transient radiations. The fast analysis is used to obtain both the ICR and energy spectra with high throughput, while the slow analysis is used to obtain high-resolution energy spectra. A complete characterization of the counting capabilities, through both theoretical and experimental approaches, was performed. The dead-time modeling, the throughput curves, the experimental time-interval distributions (TIDs) and the counting uncertainty of the recorded events of both the fast and the slow channels, measured with a planar CdTe (cadmium telluride) detector, will be presented. The throughput formula of a series of two types of dead-times is also derived. The results of dead-time corrections, performed through different methods, will be reported and discussed, pointing out the error on ICR estimation and the simplicity of the procedure. Accurate ICR estimations (nonlinearity < 0.5%) were performed by using the time widths and the TIDs (using 10 ns time bin width) of the detected pulses up to 2.2 Mcps. The digital system allows, after a simple parameter setting, different and sophisticated procedures for dead-time correction, traditionally implemented in complex/dedicated systems and time-consuming set-ups. PMID:26289270

Hopfield neural network and optical fiber sensor as intelligent heart rate monitor

NASA Astrophysics Data System (ADS)

Mutter, Kussay Nugamesh

2018-01-01

This paper presents a design and fabrication of an intelligent fiber-optic sensor used for examining and monitoring heart rate activity. It is found in the literature that the use of fiber sensors as heart rate sensor is widely studied. However, the use of smart sensors based on Hopfield neural networks is very low. In this work, the sensor is a three fibers without cladding of about 1 cm, fed by laser light of 1550 nm of wavelength. The sensing portions are mounted with a micro sensitive diaphragm to transfer the pulse pressure on the left radial wrist. The influenced light intensity will be detected by a three photodetectors as inputs into the Hopfield neural network algorithm. The latter is a singlelayer auto-associative memory structure with a same input and output layers. The prior training weights are stored in the net memory for the standard recorded normal heart rate signals. The sensors' heads work on the reflection intensity basis. The novelty here is that the sensor uses a pulse pressure and Hopfield neural network in an integrity approach. The results showed a significant output measurements of heart rate and counting with a plausible error rate.

Characterisation of the Hamamatsu photomultipliers for the KM3NeT Neutrino Telescope

NASA Astrophysics Data System (ADS)

Aiello, S.; Akrame, S. E.; Ameli, F.; Anassontzis, E. G.; Andre, M.; Androulakis, G.; Anghinolfi, M.; Anton, G.; Ardid, M.; Aublin, J.; Avgitas, T.; Baars, M.; Bagatelas, C.; Barbarino, G.; Baret, B.; Barrios-Martí, J.; Belias, A.; Berbee, E.; van den Berg, A.; Bertin, V.; Biagi, S.; Biagioni, A.; Biernoth, C.; Bormuth, R.; Boumaaza, J.; Bourret, S.; Bouwhuis, M.; Bozza, C.; Brânzaş, H.; Briukhanova, N.; Bruijn, R.; Brunner, J.; Buis, E.; Buompane, R.; Busto, J.; Calvo, D.; Capone, A.; Caramete, L.; Celli, S.; Chabab, M.; Cherubini, S.; Chiarella, V.; Chiarusi, T.; Circella, M.; Cocimano, R.; Coelho, J. A. B.; Coleiro, A.; Colomer Molla, M.; Coniglione, R.; Coyle, P.; Creusot, A.; Cuttone, G.; D'Onofrio, A.; Dallier, R.; De Sio, C.; Di Palma, I.; Díaz, A. F.; Distefano, C.; Domi, A.; Donà, R.; Donzaud, C.; Dornic, D.; Dörr, M.; Durocher, M.; Eberl, T.; van Eijk, D.; El Bojaddaini, I.; Elsaesser, D.; Enzenhöfer, A.; Ferrara, G.; Fusco, L. A.; Gal, T.; Garufi, F.; Gauchery, S.; Geißelsöder, S.; Gialanella, L.; Giorgio, E.; Giuliante, A.; Gozzini, S. R.; Ruiz, R. Gracia; Graf, K.; Grasso, D.; Grégoire, T.; Grella, G.; Hallmann, S.; van Haren, H.; Heid, T.; Heijboer, A.; Hekalo, A.; Hernández-Rey, J. J.; Hofestädt, J.; Illuminati, G.; James, C. W.; Jongen, M.; Jongewaard, B.; de Jong, M.; de Jong, P.; Kadler, M.; Kalaczyński, P.; Kalekin, O.; Katz, U. F.; Chowdhury, N. R. Khan; Kieft, G.; Kießling, D.; Koffeman, E. N.; Kooijman, P.; Kouchner, A.; Kreter, M.; Kulikovskiy, V.; Lahmann, R.; Le Breton, R.; Leone, F.; Leonora, E.; Levi, G.; Lincetto, M.; Lonardo, A.; Longhitano, F.; Lotze, M.; Loucatos, S.; Maggi, G.; Mańczak, J.; Mannheim, K.; Margiotta, A.; Marinelli, A.; Markou, C.; Martin, L.; Martínez-Mora, J. A.; Martini, A.; Marzaioli, F.; Mele, R.; Melis, K. W.; Migliozzi, P.; Migneco, E.; Mijakowski, P.; Miranda, L. S.; Mollo, C. M.; Morganti, M.; Moser, M.; Moussa, A.; Muller, R.; Musumeci, M.; Nauta, L.; Navas, S.; Nicolau, C. A.; Nielsen, C.; Organokov, M.; Orlando, A.; Panagopoulos, V.; Papalashvili, G.; Papaleo, R.; Păvălaş, G. E.; Pellegrini, G.; Pellegrino, C.; Pérez Romero, J.; Perrin-Terrin, M.; Piattelli, P.; Pikounis, K.; Pisanti, O.; Poirè, C.; Polydefki, G.; Poma, G. E.; Popa, V.; Post, M.; Pradier, T.; Pühlhofer, G.; Pulvirenti, S.; Quinn, L.; Raffaelli, F.; Randazzo, N.; Razzaque, S.; Real, D.; Resvanis, L.; Reubelt, J.; Riccobene, G.; Richer, M.; Rovelli, A.; Salvadori, I.; Samtleben, D. F. E.; Sánchez Losa, A.; Sanguineti, M.; Santangelo, A.; Sapienza, P.; Schermer, B.; Sciacca, V.; Seneca, J.; Sgura, I.; Shanidze, R.; Sharma, A.; Simeone, F.; Sinopoulou, A.; Spisso, B.; Spurio, M.; Stavropoulos, D.; Steijger, J.; Stellacci, S. M.; Strandberg, B.; Stransky, D.; Stüven, T.; Taiuti, M.; Tatone, F.; Tayalati, Y.; Tenllado, E.; Thakore, T.; Timmer, P.; Trovato, A.; Tsagkli, S.; Tzamariudaki, E.; Tzanetatos, D.; Valieri, C.; Vallage, B.; Van Elewyck, V.; Versari, F.; Viola, S.; Vivolo, D.; Volkert, M.; de Waardt, L.; Wilms, J.; de Wolf, E.; Zaborov, D.; Zornoza, J. D.; Zúñiga, J.

2018-05-01

The Hamamatsu R12199-02 3-inch photomultiplier tube is the photodetector chosen for the first phase of the KM3NeT neutrino telescope. About 7000 photomultipliers have been characterised for dark count rate, timing spread and spurious pulses. The quantum efficiency, the gain and the peak-to-valley ratio have also been measured for a sub-sample in order to determine parameter values needed as input to numerical simulations of the detector.

How Parents Read Counting Books and Non-numerical Books to Their Preverbal Infants: An Observational Study

PubMed Central

Goldstein, Alison; Cole, Thomas; Cordes, Sara

2016-01-01

Studies have stressed the importance of counting with children to promote formal numeracy abilities; however, little work has investigated when parents begin to engage in this behavior with their young children. In the current study, we investigated whether parents elaborated on numerical information when reading a counting book to their preverbal infants and whether developmental differences in numerical input exist even in the 1st year of life. Parents and their 5–10 months old infants were asked to read, as they would at home, two books to their infants: a counting book and another book that did not have numerical content. Parents’ spontaneous statements rarely focused on number and those that did consisted primarily of counting, with little emphasis on labeling the cardinality of the set. However, developmental differences were observed even in this age range, such that parents were more likely to make numerical utterances when reading to older infants. Together, results are the first to characterize naturalistic reading behaviors between parents and their preverbal infants in the context of counting books, suggesting that although counting books promote numerical language in parents, infants still receive very little in the way of numerical input before the end of the 1st year of life. While little is known regarding the impact of number talk on the cognitive development of young infants, the current results may guide future work in this area by providing the first assessment of the characteristics of parental numerical input to preverbal infants. PMID:27493639

Computing row and column counts for sparse QR and LU factorization

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

Gilbert, John R.; Li, Xiaoye S.; Ng, Esmond G.

2001-01-01

We present algorithms to determine the number of nonzeros in each row and column of the factors of a sparse matrix, for both the QR factorization and the LU factorization with partial pivoting. The algorithms use only the nonzero structure of the input matrix, and run in time nearly linear in the number of nonzeros in that matrix. They may be used to set up data structures or schedule parallel operations in advance of the numerical factorization. The row and column counts we compute are upper bounds on the actual counts. If the input matrix is strong Hall and theremore » is no coincidental numerical cancellation, the counts are exact for QR factorization and are the tightest bounds possible for LU factorization. These algorithms are based on our earlier work on computing row and column counts for sparse Cholesky factorization, plus an efficient method to compute the column elimination tree of a sparse matrix without explicitly forming the product of the matrix and its transpose.« less

Influence of residual oxygen-15-labeled carbon monoxide radioactivity on cerebral blood flow and oxygen extraction fraction in a dual-tracer autoradiographic method.

PubMed

Iwanishi, Katsuhiro; Watabe, Hiroshi; Hayashi, Takuya; Miyake, Yoshinori; Minato, Kotaro; Iida, Hidehiro

2009-06-01

Cerebral blood flow (CBF), cerebral metabolic rate of oxygen (CMRO(2)), oxygen extraction fraction (OEF), and cerebral blood volume (CBV) are quantitatively measured with PET with (15)O gases. Kudomi et al. developed a dual tracer autoradiographic (DARG) protocol that enables the duration of a PET study to be shortened by sequentially administrating (15)O(2) and C(15)O(2) gases. In this protocol, before the sequential PET scan with (15)O(2) and C(15)O(2) gases ((15)O(2)-C(15)O(2) PET scan), a PET scan with C(15)O should be preceded to obtain CBV image. C(15)O has a high affinity for red blood cells and a very slow washout rate, and residual radioactivity from C(15)O might exist during a (15)O(2)-C(15)O(2) PET scan. As the current DARG method assumes no residual C(15)O radioactivity before scanning, we performed computer simulations to evaluate the influence of the residual C(15)O radioactivity on the accuracy of measured CBF and OEF values with DARG method and also proposed a subtraction technique to minimize the error due to the residual C(15)O radioactivity. In the simulation, normal and ischemic conditions were considered. The (15)O(2) and C(15)O(2) PET count curves with the residual C(15)O PET counts were generated by the arterial input function with the residual C(15)O radioactivity. The amounts of residual C(15)O radioactivity were varied by changing the interval between the C(15)O PET scan and (15)O(2)-C(15)O(2) PET scan, and the absolute inhaled radioactivity of the C(15)O gas. Using the simulated input functions and the PET counts, the CBF and OEF were computed by the DARG method. Furthermore, we evaluated a subtraction method that subtracts the influence of the C(15)O gas in the input function and PET counts. Our simulations revealed that the CBF and OEF values were underestimated by the residual C(15)O radioactivity. The magnitude of this underestimation depended on the amount of C(15)O radioactivity and the physiological conditions. This underestimation was corrected by the subtraction method. This study showed the influence of C(15)O radioactivity in DARG protocol, and the magnitude of the influence was affected by several factors, such as the radioactivity of C(15)O, and the physiological condition.

Unattended Multiplicity Shift Register

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

Newell, Matt; Jones, David C.

2017-01-16

The Unattended Multiplicity Shift Register (UMSR) is a specialized pulse counter used primarily to count neutron events originating in neutron detection instruments. While the counter can be used to count any TTL input pulses, its unique ability to record time correlated events and the multiplicity distributions of these events makes it an ideal instrument for counting neutron events in the nuclear fields of material safeguards, waste assay and process monitoring and control. The UMSR combines the Los Alamos National Laboratory (LANL) simple and robust shift register design with a Commercial-Off-The-Shelf (COTS) processor and Ethernet communications. The UMSR is fully compatiblemore » with existing International Atomic Energy Agency (IAEA) neutron data acquisition instruments such as the Advance Multiplicity Shift Register (AMSR) and JSR-15. The UMSR has three input channels: a multiplicity shift register input and two auxiliary inputs. The UMSR provides 0V to 2kV of programmable High Voltage (HV) bias and both a 12V and a 5V detector power supply output. A serial over USB communication line to the UMSR allows the use of existing versions of INCC or MIC software while the Ethernet port is compatible with the new IAEA RAINSTORM communication protocol.« less

Method and apparatus for combinatorial logic signal processor in a digitally based high speed x-ray spectrometer

DOEpatents

Warburton, William K.; Zhou, Zhiquing

1999-01-01

A high speed, digitally based, signal processing system which accepts a digitized input signal and detects the presence of step-like pulses in the this data stream, extracts filtered estimates of their amplitudes, inspects for pulse pileup, and records input pulse rates and system livetime. The system has two parallel processing channels: a slow channel, which filters the data stream with a long time constant trapezoidal filter for good energy resolution; and a fast channel which filters the data stream with a short time constant trapezoidal filter, detects pulses, inspects for pileups, and captures peak values from the slow channel for good events. The presence of a simple digital interface allows the system to be easily integrated with a digital processor to produce accurate spectra at high count rates and allow all spectrometer functions to be fully automated. Because the method is digitally based, it allows pulses to be binned based on time related values, as well as on their amplitudes, if desired.

High-performance reconfigurable coincidence counting unit based on a field programmable gate array.

PubMed

Park, Byung Kwon; Kim, Yong-Su; Kwon, Osung; Han, Sang-Wook; Moon, Sung

2015-05-20

We present a high-performance reconfigurable coincidence counting unit (CCU) using a low-end field programmable gate array (FPGA) and peripheral circuits. Because of the flexibility guaranteed by the FPGA program, we can easily change system parameters, such as internal input delays, coincidence configurations, and the coincidence time window. In spite of a low-cost implementation, the proposed CCU architecture outperforms previous ones in many aspects: it has 8 logic inputs and 4 coincidence outputs that can measure up to eight-fold coincidences. The minimum coincidence time window and the maximum input frequency are 0.47 ns and 163 MHz, respectively. The CCU will be useful in various experimental research areas, including the field of quantum optics and quantum information.

Improving ECG Classification Accuracy Using an Ensemble of Neural Network Modules

PubMed Central

Javadi, Mehrdad; Ebrahimpour, Reza; Sajedin, Atena; Faridi, Soheil; Zakernejad, Shokoufeh

2011-01-01

This paper illustrates the use of a combined neural network model based on Stacked Generalization method for classification of electrocardiogram (ECG) beats. In conventional Stacked Generalization method, the combiner learns to map the base classifiers' outputs to the target data. We claim adding the input pattern to the base classifiers' outputs helps the combiner to obtain knowledge about the input space and as the result, performs better on the same task. Experimental results support our claim that the additional knowledge according to the input space, improves the performance of the proposed method which is called Modified Stacked Generalization. In particular, for classification of 14966 ECG beats that were not previously seen during training phase, the Modified Stacked Generalization method reduced the error rate for 12.41% in comparison with the best of ten popular classifier fusion methods including Max, Min, Average, Product, Majority Voting, Borda Count, Decision Templates, Weighted Averaging based on Particle Swarm Optimization and Stacked Generalization. PMID:22046232

Merged analog and photon counting profiles used as input for other RLPROF VAPs

DOE Data Explorer

Newsom, Rob

2014-10-03

The rlprof_merge VAP "merges" the photon counting and analog signals appropriately for each channel, creating an output data file that is very similar to the original raw data file format that the Raman lidar initially had.

Merged analog and photon counting profiles used as input for other RLPROF VAPs

DOE Data Explorer

Newsom, Rob

1998-03-01

The rlprof_merge VAP "merges" the photon counting and analog signals appropriately for each channel, creating an output data file that is very similar to the original raw data file format that the Raman lidar initially had.

Selective data segment monitoring system. [using shift registers

NASA Technical Reports Server (NTRS)

Wirth, M. N. (Inventor)

1976-01-01

High speed data monitoring apparatus is described for displaying the bit pattern of a selected portion of a block of transmitted data comprising a shift register for receiving the transmitted data and for temporarily containing the consecutive data bits. A programmable sync detector for monitoring the contents of the shift register and for generating a sync signal when the shift register contains a predetermined sync code is included. A counter is described for counting the data bits input to the shift register after the sync signal is generated and for generating a count complete signal when a selected number of data bits have been input to the register. A data storage device is used for storing the contents of the shift register at the time the count complete signal is generated.

Preparation of X-ray astronomy satellite experiment Development of computer programs for the Salyut-HEXE X-ray experiment ground station

NASA Astrophysics Data System (ADS)

Petrik, J.

The engineering model of the Salyut-HEXE experiment is described. The detector system, electronics box, and ground station are addressed. The microprocessor system is considered, discussing the cards and presenting block diagrams of their functions. The telemetry is examined, including the various modes and the direct and indirect transmission modes. The ground station programs are discussed, including the tasks, program development, input and output programs, status, power supply, count rates, telemetry dump, hard copy, and checksum.

Influences of red blood cell and platelet counts on the distribution and elimination of crystalloid fluid.

PubMed

Hahn, Robert G

2017-01-01

A high number of blood cells increases the viscosity of the blood. The present study explored whether variations in blood cell counts are relevant to the distribution and elimination of infused crystalloid fluid. On three different occasions, 10 healthy male volunteers received an intravenous infusion of 25mL/kg of Ringer's acetate, Ringer's lactate, and isotonic saline over 30min. Blood hemoglobin and urinary excretion were monitored for 4h and used as input in a two-volume kinetic model, using nonlinear mixed effects software. The covariates used in the kinetic model were red blood cell and platelet counts, the total leukocyte count, the use of isotonic saline, and the arterial pressure. Red blood cell and platelet counts in the upper end of the normal range were associated with a decreased rate of distribution and redistribution of crystalloid fluid. Simulations showed that high counts were correlated with volume expansion of the peripheral (interstitial) fluid space, while the plasma volume was less affected. In contrast, the total leukocyte count had no influence on the distribution, redistribution, or elimination. The use of isotonic saline caused a transient reduction in the systolic arterial pressure (P<0.05) and doubled the half-life of infused fluid in the body when compared to the two Ringer solutions. Isotonic saline did not decrease the serum potassium concentration, despite the fact that saline is potassium-free. High red blood cell and platelet counts are associated with peripheral accumulation of infused crystalloid fluid. Copyright © 2017 The Lithuanian University of Health Sciences. Production and hosting by Elsevier Sp. z o.o. All rights reserved.

Experimental Studies of Nuclear Physics Input for γ -Process Nucleosynthesis

NASA Astrophysics Data System (ADS)

Scholz, Philipp; Heim, Felix; Mayer, Jan; Netterdon, Lars; Zilges, Andreas

The predictions of reaction rates for the γ process in the scope of the Hauser-Feshbach statistical model crucially depend on nuclear physics input-parameters as optical-model potentials (OMP) or γ -ray strength functions. Precise cross-section measurements at astrophysically relevant energies help to constrain adopted models and, therefore, to reduce the uncertainties in the theoretically predicted reaction rates. During the last years, several cross-sections of charged-particle induced reactions on heavy nuclei have been measured at the University of Cologne. Either by means of the in-beam method at the HORUS γ -ray spectrometer or the activation technique using the Cologne Clover Counting Setup, total and partial cross-sections could be used to further constrain different models for nuclear physics input-parameters. It could be shown that modifications on the α -OMP in the case of the 112Sn(α , γ ) reaction also improve the description of the recently measured cross sections of the 108Cd(α , γ ) and 108Cd(α , n) reaction and other reactions as well. Partial cross-sections of the 92Mo(p, γ ) reaction were used to improve the γ -strength function model in 93Tc in the same way as it was done for the 89Y(p, γ ) reaction.

An analysis of I/O efficient order-statistic-based techniques for noise power estimation in the HRMS sky survey's operational system

NASA Technical Reports Server (NTRS)

Zimmerman, G. A.; Olsen, E. T.

1992-01-01

Noise power estimation in the High-Resolution Microwave Survey (HRMS) sky survey element is considered as an example of a constant false alarm rate (CFAR) signal detection problem. Order-statistic-based noise power estimators for CFAR detection are considered in terms of required estimator accuracy and estimator dynamic range. By limiting the dynamic range of the value to be estimated, the performance of an order-statistic estimator can be achieved by simpler techniques requiring only a single pass of the data. Simple threshold-and-count techniques are examined, and it is shown how several parallel threshold-and-count estimation devices can be used to expand the dynamic range to meet HRMS system requirements with minimal hardware complexity. An input/output (I/O) efficient limited-precision order-statistic estimator with wide but limited dynamic range is also examined.

OBIST methodology incorporating modified sensitivity of pulses for active analogue filter components

NASA Astrophysics Data System (ADS)

Khade, R. H.; Chaudhari, D. S.

2018-03-01

In this paper, oscillation-based built-in self-test method is used to diagnose catastrophic and parametric faults in integrated circuits. Sallen-Key low pass filter and high pass filter circuits with different gains are used to investigate defects. Variation in seven parameters of operational amplifier (OP-AMP) like gain, input impedance, output impedance, slew rate, input bias current, input offset current, input offset voltage and catastrophic as well as parametric defects in components outside OP-AMP are introduced in the circuit and simulation results are analysed. Oscillator output signal is converted to pulses which are used to generate a signature of the circuit. The signature and pulse count changes with the type of fault present in the circuit under test (CUT). The change in oscillation frequency is observed for fault detection. Designer has flexibility to predefine tolerance band of cut-off frequency and range of pulses for which circuit should be accepted. The fault coverage depends upon the required tolerance band of the CUT. We propose a modification of sensitivity of parameter (pulses) to avoid test escape and enhance yield. Result shows that the method provides 100% fault coverage for catastrophic faults.

Counting digital filters

NASA Technical Reports Server (NTRS)

Zohar, S. (Inventor)

1973-01-01

Several embodiments of a counting digital filter of the non-recursive type are disclosed. In each embodiment two registers, at least one of which is a shift register, are included. The shift register received j sub x-bit data input words bit by bit. The kth data word is represented by the integer.

Assessment of Traffic-Related Noise in Three Cities in the United States

PubMed Central

Lee, Eunice Y.; Jerrett, Michael; Ross, Zev; Coogan, Patricia F.; Seto, Edmund Y. W.

2014-01-01

Background Traffic-related noise is a growing public health concern in developing and developed countries due to increasing vehicle traffic. Epidemiological studies have reported associations between noise exposure and high blood pressure, increased risk of hypertension and heart disease, and stress induced by sleep disturbance and annoyance. These findings motivate the need for regular noise assessments within urban areas. This paper assesses the relationships between traffic and noise in three US cities. Methods Noise measurements were conducted in downtown areas in three cities in the United States: Atlanta, Los Angeles, and New York City. For each city, we measured ambient noise levels, and assessed their correlation with simultaneously measured vehicle counts, and with traffic data provided by local Metropolitan Planning Organizations (MPO). Additionally, measured noise levels were compared to noise levels predicted by the Federal Highway Administration’s Traffic Noise Model using (1) simultaneously measured traffic counts or (2) MPO traffic data sources as model input. Results We found substantial variations in traffic and noise within and between cities. Total number of vehicle counts explained a substantial amount of variation in measured ambient noise in Atlanta (78%), Los Angeles (58%), and New York City (62%). Modeled noise levels were moderately correlated with measured noise levels when observed traffic counts were used as model input. Weaker correlations were found when MPO traffic data was used as model input. Conclusions Ambient noise levels measured in all three cities were correlated with traffic data, highlighting the importance of traffic planning in mitigating noise-related health effects. Model performance was sensitive to the traffic data used as input. Future noise studies that use modeled noise estimates should evaluate traffic data quality and should ideally include other factors, such as local roadway, building, and meteorological characteristics. PMID:24792415

Method and apparatus for combinatorial logic signal processor in a digitally based high speed x-ray spectrometer

DOEpatents

Warburton, W.K.

1999-02-16

A high speed, digitally based, signal processing system is disclosed which accepts a digitized input signal and detects the presence of step-like pulses in the this data stream, extracts filtered estimates of their amplitudes, inspects for pulse pileup, and records input pulse rates and system lifetime. The system has two parallel processing channels: a slow channel, which filters the data stream with a long time constant trapezoidal filter for good energy resolution; and a fast channel which filters the data stream with a short time constant trapezoidal filter, detects pulses, inspects for pileups, and captures peak values from the slow channel for good events. The presence of a simple digital interface allows the system to be easily integrated with a digital processor to produce accurate spectra at high count rates and allow all spectrometer functions to be fully automated. Because the method is digitally based, it allows pulses to be binned based on time related values, as well as on their amplitudes, if desired. 31 figs.

Results of the first continuous meteor head echo survey at polar latitudes

NASA Astrophysics Data System (ADS)

Schult, Carsten; Stober, Gunter; Janches, Diego; Chau, Jorge L.

2017-11-01

We present the first quasi continuous meteor head echo measurements obtained during a period of over two years using the Middle Atmosphere ALOMAR Radar System (MAARSY). The measurements yield information on the altitude, trajectory, vector velocity, radar cross section, deceleration and dynamical mass of every single event. The large statistical amount of nearly one million meteor head detections provide an excellent overview of the elevation, altitude, velocity and daily count rate distributions during different times of the year at polar latitudes. Only 40% of the meteors were detected within the full width half maximum of the specific sporadic meteor sources. Our observation of the sporadic meteors are compared to the observations with other radar systems and a meteor input function (MIF). The best way to compare different radar systems is by comparing the radar cross section (RCS), which is the main detection criterion for each system. In this study we aim to compare our observations with a MIF, which provides information only about the meteoroid mass. Thus, we are using a statistical approach for the elevation and velocity dependent visibility and a specific mass selection. The predicted absolute count rates from the MIF are in a good agreement with the observation when it is assumed that the radar system is only sensitive to meteoroids with masses higher than one microgram. The analysis of the dynamic masses seems to be consistent with this assumption since the count rate of events with smaller masses are low and decrease even more by using events with relatively small errors.

Entangled-Pair Transmission Improvement Using Distributed Phase-Sensitive Amplification

NASA Astrophysics Data System (ADS)

Agarwal, Anjali; Dailey, James M.; Toliver, Paul; Peters, Nicholas A.

2014-10-01

We demonstrate the transmission of time-bin entangled photon pairs through a distributed optical phase-sensitive amplifier (OPSA). We utilize four-wave mixing at telecom wavelengths in a 5-km dispersion-shifted fiber OPSA operating in the low-gain limit. Measurements of two-photon interference curves show no statistically significant degradation in the fringe visibility at the output of the OPSA. In addition, coincidence counting rates are higher than direct passive transmission because of constructive interference between amplitudes of input photon pairs and those generated in the OPSA. Our results suggest that application of distributed phase-sensitive amplification to transmission of entangled photon pairs could be highly beneficial towards advancing the rate and scalability of future quantum communications systems.

Carving up Word Meaning: Portioning and Grinding

ERIC Educational Resources Information Center

Frisson, S.; Frazier, L.

2005-01-01

Two eye-tracking experiments investigated the processing of mass nouns used as count nouns and count nouns used as mass nouns. Following Copestake and Briscoe (1995), the basic or underived sense of a word was treated as the input to a derivational rule (''grinding'' or ''portioning'') which produced the derived sense as output. It was…

UDATE1: A computer program for the calculation of uranium-series isotopic ages

USGS Publications Warehouse

Rosenbauer, R.J.

1991-01-01

UDATE1 is a FORTRAN-77 program with an interface for an Apple Macintosh computer that calculates isotope activities from measured count rates to date geologic materials by uranium-series disequilibria. Dates on pure samples can be determined directly by the accumulation of 230Th from 234U and of 231Pa from 235U. Dates for samples contaminated by clays containing abundant natural thorium can be corrected by the program using various mixing models. Input to the program and file management are made simple and user friendly by a series of Macintosh modal dialog boxes. ?? 1991.

Complementary frame reconstruction: a low-biased dynamic PET technique for low count density data in projection space

NASA Astrophysics Data System (ADS)

Hong, Inki; Cho, Sanghee; Michel, Christian J.; Casey, Michael E.; Schaefferkoetter, Joshua D.

2014-09-01

A new data handling method is presented for improving the image noise distribution and reducing bias when reconstructing very short frames from low count dynamic PET acquisition. The new method termed ‘Complementary Frame Reconstruction’ (CFR) involves the indirect formation of a count-limited emission image in a short frame through subtraction of two frames with longer acquisition time, where the short time frame data is excluded from the second long frame data before the reconstruction. This approach can be regarded as an alternative to the AML algorithm recently proposed by Nuyts et al, as a method to reduce the bias for the maximum likelihood expectation maximization (MLEM) reconstruction of count limited data. CFR uses long scan emission data to stabilize the reconstruction and avoids modification of algorithms such as MLEM. The subtraction between two long frame images, naturally allows negative voxel values and significantly reduces bias introduced in the final image. Simulations based on phantom and clinical data were used to evaluate the accuracy of the reconstructed images to represent the true activity distribution. Applicability to determine the arterial input function in human and small animal studies is also explored. In situations with limited count rate, e.g. pediatric applications, gated abdominal, cardiac studies, etc., or when using limited doses of short-lived isotopes such as 15O-water, the proposed method will likely be preferred over independent frame reconstruction to address bias and noise issues.

Turtle: identifying frequent k-mers with cache-efficient algorithms.

PubMed

Roy, Rajat Shuvro; Bhattacharya, Debashish; Schliep, Alexander

2014-07-15

Counting the frequencies of k-mers in read libraries is often a first step in the analysis of high-throughput sequencing data. Infrequent k-mers are assumed to be a result of sequencing errors. The frequent k-mers constitute a reduced but error-free representation of the experiment, which can inform read error correction or serve as the input to de novo assembly methods. Ideally, the memory requirement for counting should be linear in the number of frequent k-mers and not in the, typically much larger, total number of k-mers in the read library. We present a novel method that balances time, space and accuracy requirements to efficiently extract frequent k-mers even for high-coverage libraries and large genomes such as human. Our method is designed to minimize cache misses in a cache-efficient manner by using a pattern-blocked Bloom filter to remove infrequent k-mers from consideration in combination with a novel sort-and-compact scheme, instead of a hash, for the actual counting. Although this increases theoretical complexity, the savings in cache misses reduce the empirical running times. A variant of method can resort to a counting Bloom filter for even larger savings in memory at the expense of false-negative rates in addition to the false-positive rates common to all Bloom filter-based approaches. A comparison with the state-of-the-art shows reduced memory requirements and running times. The tools are freely available for download at http://bioinformatics.rutgers.edu/Software/Turtle and http://figshare.com/articles/Turtle/791582. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Comparing generativist and constructivist accounts of the use of the past tense form in early child Japanese.

PubMed

Tatsumi, Tomoko; Pine, Julian M

2016-11-01

The present study investigated children's early use of verb inflection in Japanese by comparing a generativist account, which predicts that the past tense will have a special default-like status for the child during the early stages, with a constructivist input-driven account, which assumes that children's acquisition and use of inflectional forms reflects verb-specific distributional patterns in their input. Analysis of naturalistic data from four Japanese children aged 1;5 to 2;10 showed that there was substantial by-verb variation in the use of inflectional forms from the earliest stages of verb use, and no general preference for past tense forms. Correlational and partial correlational analyses showed that it was possible to predict the proportional frequency with which the child produced verbs in past tense versus other inflectional forms on the basis of differences in the proportional frequency with which the verb occurred in past tense form in the child's input, even after controlling for differences in the rate at which verbs occurred in past tense form in input averaged across the caregivers of the other children in the sample. When taken together, these results count against the idea that the past tense has a special default-like status in early child Japanese, and in favour of a constructivist input-driven account of children's early use of verb inflection.

Cross-Section Measurements via the Activation Technique at the Cologne Clover Counting Setup

NASA Astrophysics Data System (ADS)

Heim, Felix; Mayer, Jan; Netterdon, Lars; Scholz, Philipp; Zilges, Andreas

The activation technique is a widely used method for the determination of cross-section values for charged-particle induced reactions at astrophysically relevant energies. Since network calculations of nucleosynthesis processes often depend on reaction rates calculated in the scope of the Hauser-Feshbach statistical model, these cross-sections can be used to improve the nuclear-physics input-parameters like optical-model potentials (OMP), γ-ray strength functions, and nuclear level densities. In order to extend the available experimental database, the 108Cd(α, n)111Sn reaction cross section was investigated at ten energies between 10.2 and 13.5 MeV. As this reaction at these energies is almost only sensitive on the α-decay width, the results were compared to statistical model calculations using different models for the α-OMP. The irradiation as well as the consecutive γ-ray counting were performed at the Institute for Nuclear Physics of the University of Cologne using the 10 MV FN-Tandem accelerator and the Cologne Clover Counting Setup. This setup consists of two clover- type high purity germanium (HPGe) detectors in a close face-to-face geometry to cover a solid angle of almost 4π.

A novel nanoscaled Schottky barrier based transmission gate and its digital circuit applications

NASA Astrophysics Data System (ADS)

Kumar, Sunil; Loan, Sajad A.; Alamoud, Abdulrahman M.

2017-04-01

In this work we propose and simulate a compact nanoscaled transmission gate (TG) employing a single Schottky barrier based transistor in the transmission path and a single transistor based Sajad-Sunil-Schottky (SSS) device as an inverter. Therefore, just two transistors are employed to realize a complete transmission gate which normally consumes four transistors in the conventional technology. The transistors used to realize the transmission path and the SSS inverter in the proposed TG are the double gate Schottky barrier devices, employing stacks of two metal silicides, platinum silicide (PtSi) and erbium silicide (ErSi). It has been observed that the realization of the TG gate by the proposed technology has resulted into a compact structure, with reduced component count, junctions, interconnections and regions in comparison to the conventional technology. The further focus of this work is on the application part of the proposed technology. So for the first time, the proposed technology has been used to realize various combinational circuits, like a two input AND gate, a 2:1 multiplexer and a two input XOR circuits. It has been observed that the transistor count has got reduced by half in a TG, two input AND gate, 2:1 multiplexer and in a two input XOR gate. Therefore, a significant reduction in transistor count and area requirement can be achieved by using the proposed technology. The proposed technology can be also used to perform the compact realization of other combinational and sequential circuitry in future.

Solid-state image sensor with focal-plane digital photon-counting pixel array

NASA Technical Reports Server (NTRS)

Fossum, Eric R. (Inventor); Pain, Bedabrata (Inventor)

1995-01-01

A photosensitive layer such as a-Si for a UV/visible wavelength band is provided for low light level imaging with at least a separate CMOS amplifier directly connected to each PIN photodetector diode to provide a focal-plane array of NxN pixels, and preferably a separate photon-counting CMOS circuit directly connected to each CMOS amplifier, although one row of counters may be time shared for reading out the photon flux rate of each diode in the array, together with a buffer memory for storing all rows of the NxN image frame before transfer to suitable storage. All CMOS circuitry is preferably fabricated in the same silicon layer as the PIN photodetector diode for a monolithic structure, but when the wavelength band of interest requires photosensitive material different from silicon, the focal-plane array may be fabricated separately on a different semiconductor layer bump-bonded or otherwise bonded for a virtually monolithic structure with one free terminal of each diode directly connected to the input terminal of its CMOS amplifier and digital counter for integration of the photon flux rate at each photodetector of the array.

In-line wear monitor. Final report, July 1988-April 1989

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

Pieper, K.A.; Taylor, I.J.

This report describes construction and test results of an in-line monitor for critical ferrous and nonferrous metal debris in turbine engine lubrication systems. The in-line wear monitor (ILWM) uses the X-ray fluorescence principle for detecting metal debris on a continuous basis while the engine is running. The sensor portion of the system is engine mounted and contains a radioactive X-ray source, a flow cell to direct the oil across an X-ray permeable window, a proportional counter X-ray detector and its associated preamplifier and amplifier electronics. The data acquisition electronics is mounted on the airframe and contains a microprocessor based systemmore » for inputting pulses from the sensor, classifying and counting them according to energy bands, and analyzing the data and outputting metal concentration values to the engine monitoring system. The sensor portion of the system is designed to fit on a TF41 turbine engine in place of a tube between the oil tank and the oil pump. A TF41 engine monitoring system has been modified to accept the new signals from the ILWM on spare inputs so that none of the existing functions were disturbed. The ILWM has been flow tested at various flow rates, concentration levels, oil temperatures, and aerations. The wear monitor detected iron, copper, and both iron and copper together with less than 2 ppm one sigma statistical uncertainty for 30 minute count times over the 0-50 ppm range. There was no significant effect of flow rate or aeration on accuracy. The system is developed to the point that it can be tested in an actual flight environment.« less

Microbial Source Module (MSM): Documenting the Science ...

EPA Pesticide Factsheets

The Microbial Source Module (MSM) estimates microbial loading rates to land surfaces from non-point sources, and to streams from point sources for each subwatershed within a watershed. A subwatershed, the smallest modeling unit, represents the common basis for information consumed and produced by the MSM which is based on the HSPF (Bicknell et al., 1997) Bacterial Indicator Tool (EPA, 2013b, 2013c). Non-point sources include numbers, locations, and shedding rates of domestic agricultural animals (dairy and beef cows, swine, poultry, etc.) and wildlife (deer, duck, raccoon, etc.). Monthly maximum microbial storage and accumulation rates on the land surface, adjusted for die-off, are computed over an entire season for four land-use types (cropland, pasture, forest, and urbanized/mixed-use) for each subwatershed. Monthly point source microbial loadings to instream locations (i.e., stream segments that drain individual sub-watersheds) are combined and determined for septic systems, direct instream shedding by cattle, and POTWs/WWTPs (Publicly Owned Treatment Works/Wastewater Treatment Plants). The MSM functions within a larger modeling system that characterizes human-health risk resulting from ingestion of water contaminated with pathogens. The loading estimates produced by the MSM are input to the HSPF model that simulates flow and microbial fate/transport within a watershed. Microbial counts within recreational waters are then input to the MRA-IT model (Soller et

Application of an Artificial Neural Network to the Prediction of OH Radical Reaction Rate Constants for Evaluating Global Warming Potential.

PubMed

Allison, Thomas C

2016-03-03

Rate constants for reactions of chemical compounds with hydroxyl radical are a key quantity used in evaluating the global warming potential of a substance. Experimental determination of these rate constants is essential, but it can also be difficult and time-consuming to produce. High-level quantum chemistry predictions of the rate constant can suffer from the same issues. Therefore, it is valuable to devise estimation schemes that can give reasonable results on a variety of chemical compounds. In this article, the construction and training of an artificial neural network (ANN) for the prediction of rate constants at 298 K for reactions of hydroxyl radical with a diverse set of molecules is described. Input to the ANN consists of counts of the chemical bonds and bends present in the target molecule. The ANN is trained using 792 (•)OH reaction rate constants taken from the NIST Chemical Kinetics Database. The mean unsigned percent error (MUPE) for the training set is 12%, and the MUPE of the testing set is 51%. It is shown that the present methodology yields rate constants of reasonable accuracy for a diverse set of inputs. The results are compared to high-quality literature values and to another estimation scheme. This ANN methodology is expected to be of use in a wide range of applications for which (•)OH reaction rate constants are required. The model uses only information that can be gathered from a 2D representation of the molecule, making the present approach particularly appealing, especially for screening applications.

Status of the NIST Penning-Trap Neutron Lifetime Measurement

NASA Astrophysics Data System (ADS)

Snow, W. M.; Fei, X.; Chowdhuri, Z.; Dewey, M. S.; Gilliam, D.; Nico, J. S.; Greene, G. L.

1998-10-01

The decay rate of the free neutron is important input for Big-Bang Nucleosynthesis calculations of the primordial ^4He abundance in the universe(T. P. Walker et al, Astrophys. J. 376, 51 (1991).) and for tests of the electroweak model in the charged-current sector(I. S. Towner, Nucl. Phys. A540, 478 (1992).). We will describe an experiment in progress at NIST to measure the neutron decay rate. The technique uses a Penning trap to trap and count protons from in-beam neutron decay(J. Byrne et al., Phys. Rev. Lett. 65, 289 (1990).) and an absolutely calibrated beam monitor to measure the neutron density in the beam(R. D. Scott et al., Nucl. Inst. Meth. A362, 151 (1995).). We will present data taken in the spring and summer of 1998.

Multichannel low power time-to-digital converter card with 21 ps precision and full scale range up to 10 μs

NASA Astrophysics Data System (ADS)

Tamborini, D.; Portaluppi, D.; Villa, F.; Tisa, S.; Tosi, A.

2014-11-01

We present a Time-to-Digital Converter (TDC) card with a compact form factor, suitable for multichannel timing instruments or for integration into more complex systems. The TDC Card provides 10 ps timing resolution over the whole measurement range, which is selectable from 160 ns up to 10 μs, reaching 21 ps rms precision, 1.25% LSB rms differential nonlinearity, up to 3 Mconversion/s with 400 mW power consumption. The I/O edge card connector provides timing data readout through either a parallel bus or a 100 MHz serial interface and further measurement information like input signal rate and valid conversion rate (typically useful for time-correlated single-photon counting application) through an independent serial link.

Multichannel low power time-to-digital converter card with 21 ps precision and full scale range up to 10 μs.

PubMed

Tamborini, D; Portaluppi, D; Villa, F; Tisa, S; Tosi, A

2014-11-01

We present a Time-to-Digital Converter (TDC) card with a compact form factor, suitable for multichannel timing instruments or for integration into more complex systems. The TDC Card provides 10 ps timing resolution over the whole measurement range, which is selectable from 160 ns up to 10 μs, reaching 21 ps rms precision, 1.25% LSB rms differential nonlinearity, up to 3 Mconversion/s with 400 mW power consumption. The I/O edge card connector provides timing data readout through either a parallel bus or a 100 MHz serial interface and further measurement information like input signal rate and valid conversion rate (typically useful for time-correlated single-photon counting application) through an independent serial link.

Investigation of FPGA-Based Real-Time Adaptive Digital Pulse Shaping for High-Count-Rate Applications

NASA Astrophysics Data System (ADS)

Saxena, Shefali; Hawari, Ayman I.

2017-07-01

Digital signal processing techniques have been widely used in radiation spectrometry to provide improved stability and performance with compact physical size over the traditional analog signal processing. In this paper, field-programmable gate array (FPGA)-based adaptive digital pulse shaping techniques are investigated for real-time signal processing. National Instruments (NI) NI 5761 14-bit, 250-MS/s adaptor module is used for digitizing high-purity germanium (HPGe) detector's preamplifier pulses. Digital pulse processing algorithms are implemented on the NI PXIe-7975R reconfigurable FPGA (Kintex-7) using the LabVIEW FPGA module. Based on the time separation between successive input pulses, the adaptive shaping algorithm selects the optimum shaping parameters (rise time and flattop time of trapezoid-shaping filter) for each incoming signal. A digital Sallen-Key low-pass filter is implemented to enhance signal-to-noise ratio and reduce baseline drifting in trapezoid shaping. A recursive trapezoid-shaping filter algorithm is employed for pole-zero compensation of exponentially decayed (with two-decay constants) preamplifier pulses of an HPGe detector. It allows extraction of pulse height information at the beginning of each pulse, thereby reducing the pulse pileup and increasing throughput. The algorithms for RC-CR2 timing filter, baseline restoration, pile-up rejection, and pulse height determination are digitally implemented for radiation spectroscopy. Traditionally, at high-count-rate conditions, a shorter shaping time is preferred to achieve high throughput, which deteriorates energy resolution. In this paper, experimental results are presented for varying count-rate and pulse shaping conditions. Using adaptive shaping, increased throughput is accepted while preserving the energy resolution observed using the longer shaping times.

What Counts as Effective Input for Word Learning?

ERIC Educational Resources Information Center

Shneidman, Laura A.; Arroyo, Michelle E.; Levine, Susan C.; Goldin-Meadow, Susan

2013-01-01

The talk children hear from their primary caregivers predicts the size of their vocabularies. But children who spend time with multiple individuals also hear talk that others direct to them, as well as talk not directed to them at all. We investigated the effect of linguistic input on vocabulary acquisition in children who routinely spent time…

Compton suppression gamma-counting: The effect of count rate

USGS Publications Warehouse

Millard, H.T.

1984-01-01

Past research has shown that anti-coincidence shielded Ge(Li) spectrometers enhanced the signal-to-background ratios for gamma-photopeaks, which are situated on high Compton backgrounds. Ordinarily, an anti- or non-coincidence spectrum (A) and a coincidence spectrum (C) are collected simultaneously with these systems. To be useful in neutron activation analysis (NAA), the fractions of the photopeak counts routed to the two spectra must be constant from sample to sample to variations must be corrected quantitatively. Most Compton suppression counting has been done at low count rate, but in NAA applications, count rates may be much higher. To operate over the wider dynamic range, the effect of count rate on the ratio of the photopeak counts in the two spectra (A/C) was studied. It was found that as the count rate increases, A/C decreases for gammas not coincident with other gammas from the same decay. For gammas coincident with other gammas, A/C increases to a maximum and then decreases. These results suggest that calibration curves are required to correct photopeak areas so quantitative data can be obtained at higher count rates. ?? 1984.

Quantum Key Distribution Using Polarized Single Photons

DTIC Science & Technology

2009-04-01

liquid helium the SSPD with a low - noise , cryogenic high-electron-mobility transistor (HEMT) with high-input impedance. This arrangement allowed us...Sobolewski, IEEE Trans. Appl. Supercon., accepted (2009). 19. " Measurements of amplitude distributions of dark counts and photon counts in NbN ...75, 174507 (2007). 6. "Fiber-Coupled NbN Superconducting Single-Photon Detectors for Quantum Correlation Measurements ," W. Slysz, M. Wegrzecki, J

Laminar Organization of Attentional Modulation in Macaque Visual Area V4.

PubMed

Nandy, Anirvan S; Nassi, Jonathan J; Reynolds, John H

2017-01-04

Attention is critical to perception, serving to select behaviorally relevant information for privileged processing. To understand the neural mechanisms of attention, we must discern how attentional modulation varies by cell type and across cortical layers. Here, we test whether attention acts non-selectively across cortical layers or whether it engages the laminar circuit in specific and selective ways. We find layer- and cell-class-specific differences in several different forms of attentional modulation in area V4. Broad-spiking neurons in the superficial layers exhibit attention-mediated increases in firing rate and decreases in variability. Spike count correlations are highest in the input layer and attention serves to reduce these correlations. Superficial and input layer neurons exhibit attention-dependent decreases in low-frequency (<10 Hz) coherence, but deep layer neurons exhibit increases in coherence in the beta and gamma frequency ranges. Our study provides a template for attention-mediated laminar information processing that might be applicable across sensory modalities. Copyright © 2017 Elsevier Inc. All rights reserved.

Multichannel low power time-to-digital converter card with 21 ps precision and full scale range up to 10 μs

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

Tamborini, D., E-mail: davide.tamborini@polimi.it; Portaluppi, D.; Villa, F.

We present a Time-to-Digital Converter (TDC) card with a compact form factor, suitable for multichannel timing instruments or for integration into more complex systems. The TDC Card provides 10 ps timing resolution over the whole measurement range, which is selectable from 160 ns up to 10 μs, reaching 21 ps rms precision, 1.25% LSB rms differential nonlinearity, up to 3 Mconversion/s with 400 mW power consumption. The I/O edge card connector provides timing data readout through either a parallel bus or a 100 MHz serial interface and further measurement information like input signal rate and valid conversion rate (typically usefulmore » for time-correlated single-photon counting application) through an independent serial link.« less

Single molecule counting and assessment of random molecular tagging errors with transposable giga-scale error-correcting barcodes.

PubMed

Lau, Billy T; Ji, Hanlee P

2017-09-21

RNA-Seq measures gene expression by counting sequence reads belonging to unique cDNA fragments. Molecular barcodes commonly in the form of random nucleotides were recently introduced to improve gene expression measures by detecting amplification duplicates, but are susceptible to errors generated during PCR and sequencing. This results in false positive counts, leading to inaccurate transcriptome quantification especially at low input and single-cell RNA amounts where the total number of molecules present is minuscule. To address this issue, we demonstrated the systematic identification of molecular species using transposable error-correcting barcodes that are exponentially expanded to tens of billions of unique labels. We experimentally showed random-mer molecular barcodes suffer from substantial and persistent errors that are difficult to resolve. To assess our method's performance, we applied it to the analysis of known reference RNA standards. By including an inline random-mer molecular barcode, we systematically characterized the presence of sequence errors in random-mer molecular barcodes. We observed that such errors are extensive and become more dominant at low input amounts. We described the first study to use transposable molecular barcodes and its use for studying random-mer molecular barcode errors. Extensive errors found in random-mer molecular barcodes may warrant the use of error correcting barcodes for transcriptome analysis as input amounts decrease.

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.

NEMA count-rate evaluation of the first and second generation of the Ecat Exact and Ecat Exact HR family of scanners

NASA Astrophysics Data System (ADS)

Eriksson, L.; Wienhard, K.; Eriksson, M.; Casey, M. E.; Knoess, C.; Bruckbauer, T.; Hamill, J.; Mulnix, T.; Vollmar, S.; Bendriem, B.; Heiss, W. D.; Nutt, R.

2002-06-01

The first and second generation of the Exact and Exact HR family of scanners has been evaluated in terms of noise equivalent count rate (NEC) and count-rate capabilities. The new National Electrical Manufacturers Association standard was used for the evaluation. In spite of improved electronics and improved count-rate capabilities, the peak NEC was found to be fairly constant between the generations. The results are discussed in terms of the different electronic solutions for the two generations and its implications on system dead time and NEC count-rate capability.

Compensated count-rate circuit for radiation survey meter

DOEpatents

Todd, Richard A.

1981-01-01

A count-rate compensating circuit is provided which may be used in a portable Geiger-Mueller (G-M) survey meter to ideally compensate for counting loss errors in the G-M tube detector. In a G-M survey meter, wherein the pulse rate from the G-M tube is converted into a pulse rate current applied to a current meter calibrated to indicate dose rate, the compensated circuit generates and controls a reference voltage in response to the rate of pulses from the detector. This reference voltage is gated to the current-generating circuit at a rate identical to the rate of pulses coming from the detector so that the current flowing through the meter is varied in accordance with both the frequency and amplitude of the reference voltage pulses applied thereto so that the count rate is compensated ideally to indicate a true count rate within 1% up to a 50% duty cycle for the detector. A positive feedback circuit is used to control the reference voltage so that the meter output tracks true count rate indicative of the radiation dose rate.

Advanced Wavefront Sensor Concepts.

DTIC Science & Technology

1981-01-01

internal optics (a) Characteristics (see Figure 47) - Intensification with a 256 element linear self scanned diode array - Optical input; lenticular ...34 diameter - Lenticular array input to fiber optics which spread out to tubes - Photon counting for low noise fac- tor (b) Pe r fo rmance - Bialkali...problem in making the lenslet arrays in the pupil divider rectangular. The last optical elements are the lenticular lens arrays. In this group, the first

Bayesian analysis of energy and count rate data for detection of low count rate radioactive sources.

PubMed

Klumpp, John; Brandl, Alexander

2015-03-01

A particle counting and detection system is proposed that searches for elevated count rates in multiple energy regions simultaneously. The system analyzes time-interval data (e.g., time between counts), as this was shown to be a more sensitive technique for detecting low count rate sources compared to analyzing counts per unit interval (Luo et al. 2013). Two distinct versions of the detection system are developed. The first is intended for situations in which the sample is fixed and can be measured for an unlimited amount of time. The second version is intended to detect sources that are physically moving relative to the detector, such as a truck moving past a fixed roadside detector or a waste storage facility under an airplane. In both cases, the detection system is expected to be active indefinitely; i.e., it is an online detection system. Both versions of the multi-energy detection systems are compared to their respective gross count rate detection systems in terms of Type I and Type II error rates and sensitivity.

Superconducting analog-to-digital converter with a triple-junction reversible flip-flop bidirectional counter

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

Lee, G.S.

1993-07-13

A high-performance superconducting analog-to-digital converter is described, comprising: a bidirectional binary counter having n stages of triple-junction reversible flip-flops connected together in a cascade arrangement from the least significant bit (LSB) to the most significant bit (MSB) where n is the number of bits of the digital output, each triple-junction reversible flip-flop including first, second and third shunted Josephson tunnel junctions and a superconducting inductor connected in a bridge circuit, the Josephson junctions and the inductor forming upper and lower portions of the flip-flop, each reversible flip-flop being a bistable logic circuit in which the direction of the circulating currentmore » determines the state of the circuit; and means for applying an analog input current to the bidirectional counter; wherein the bidirectional counter algebraically counts incremental changes in the analog input current, increasing the binary count for positive incremental changes in the analog current and decreasing the binary count for negative incremental changes in the current, and wherein the counter does not require a gate bias, thus minimizing power dissipation.« less

Relationship between salivary flow rates and Candida albicans counts.

PubMed

Navazesh, M; Wood, G J; Brightman, V J

1995-09-01

Seventy-one persons (48 women, 23 men; mean age, 51.76 years) were evaluated for salivary flow rates and Candida albicans counts. Each person was seen on three different occasions. Samples of unstimulated whole, chewing-stimulated whole, acid-stimulated parotid, and candy-stimulated parotid saliva were collected under standardized conditions. An oral rinse was also obtained and evaluated for Candida albicans counts. Unstimulated and chewing-stimulated whole flow rates were negatively and significantly (p < 0.001) related to the Candida counts. Unstimulated whole saliva significantly (p < 0.05) differed in persons with Candida counts of 0 versus <500 versus < or = 500. Chewing-stimulated saliva was significantly (p < 0.05) different in persons with 0 counts compared with those with a > or = 500 count. Differences in stimulated parotid flow rates were not significant among different levels of Candida counts. The results of this study reveal that whole saliva is a better predictor than parotid saliva in identification of persons with high Candida albicans counts.

A Six-Year Study on the Changes in Airborne Pollen Counts and Skin Positivity Rates in Korea: 2008–2013

PubMed Central

Park, Hye Jung; Lee, Jae-Hyun; Park, Kyung Hee; Kim, Kyu Rang; Han, Mae Ja; Choe, Hosoeng

2016-01-01

Purpose The occurrence of pollen allergy is subject to exposure to pollen, which shows regional and temporal variations. We evaluated the changes in pollen counts and skin positivity rates for 6 years, and explored the correlation between their annual rates of change. Materials and Methods We assessed the number of pollen grains collected in Seoul, and retrospectively reviewed the results of 4442 skin-prick tests conducted at the Severance Hospital Allergy-Asthma Clinic from January 1, 2008 to December 31, 2013. Results For 6 years, the mean monthly total pollen count showed two peaks, one in May and the other in September. Pollen count for grasses also showed the same trend. The pollen counts for trees, grasses, and weeds changed annually, but the changes were not significant. The annual skin positivity rates in response to pollen from grasses and weeds increased significantly over the 6 years. Among trees, the skin positivity rates in response to pollen from walnut, popular, elm, and alder significantly increased over the 6 years. Further, there was a significant correlation between the annual rate of change in pollen count and the rate of change in skin positivity rate for oak and hop Japanese. Conclusion The pollen counts and skin positivity rates should be monitored, as they have changed annually. Oak and hop Japanese, which showed a significant correlation with the annual rate of change in pollen count and the rate of change in skin positivity rate over the 6 years may be considered the major allergens in Korea. PMID:26996572

A Six-Year Study on the Changes in Airborne Pollen Counts and Skin Positivity Rates in Korea: 2008-2013.

PubMed

Park, Hye Jung; Lee, Jae-Hyun; Park, Kyung Hee; Kim, Kyu Rang; Han, Mae Ja; Choe, Hosoeng; Oh, Jae-Won; Hong, Chein-Soo

2016-05-01

The occurrence of pollen allergy is subject to exposure to pollen, which shows regional and temporal variations. We evaluated the changes in pollen counts and skin positivity rates for 6 years, and explored the correlation between their annual rates of change. We assessed the number of pollen grains collected in Seoul, and retrospectively reviewed the results of 4442 skin-prick tests conducted at the Severance Hospital Allergy-Asthma Clinic from January 1, 2008 to December 31, 2013. For 6 years, the mean monthly total pollen count showed two peaks, one in May and the other in September. Pollen count for grasses also showed the same trend. The pollen counts for trees, grasses, and weeds changed annually, but the changes were not significant. The annual skin positivity rates in response to pollen from grasses and weeds increased significantly over the 6 years. Among trees, the skin positivity rates in response to pollen from walnut, popular, elm, and alder significantly increased over the 6 years. Further, there was a significant correlation between the annual rate of change in pollen count and the rate of change in skin positivity rate for oak and hop Japanese. The pollen counts and skin positivity rates should be monitored, as they have changed annually. Oak and hop Japanese, which showed a significant correlation with the annual rate of change in pollen count and the rate of change in skin positivity rate over the 6 years may be considered the major allergens in Korea.

Impact of double counting and transfer bias on estimated rates and outcomes of acute myocardial infarction.

PubMed

Westfall, J M; McGloin, J

2001-05-01

Ischemic heart disease is the leading cause of death in the United States. Recent studies report inconsistent findings on the changes in the incidence of hospitalizations for ischemic heart disease. These reports have relied primarily on hospital discharge data. Preliminary data suggest that a significant percentage of patients suffering acute myocardial infarction (MI) in rural communities are transferred to urban centers for care. Patients transferred to a second hospital may be counted twice for one episode of ischemic heart disease. To describe the impact of double counting and transfer bias on the estimation of incidence rates and outcomes of ischemic heart disease, specifically acute MI, in the United States. Analysis of state hospital discharge data from Kansas, Colorado (State Inpatient Database [SID]), Nebraska, Arizona, New Jersey, Michigan, Pennsylvania, and Illinois (SID) for the years 1995 to 1997. A matching algorithm was developed for hospital discharges to determine patients counted twice for one episode of ischemic heart disease. Validation of our matching algorithm. Patients reported to have suffered ischemic heart disease (ICD9 codes 410-414, 786.5). Number of patients counted twice for one episode of acute MI. It is estimated that double count rates range from 10% to 15% for all states and increased over the 3 years. Moderate sized rural counties had the highest estimated double count rates at 15% to 20% with a few counties having estimated double count rates a high as 35% to 50%. Older patients and females were less likely to be double counted (P <0.05). Double counting patients has resulted in a significant overestimation in the incidence rate for hospitalization for acute MI. Correction of this double counting reveals a significantly lower incidence rate and a higher in-hospital mortality rate for acute MI. Transferred patients differ significantly from nontransferred patients, introducing significant bias into MI outcome studies. Double counting and transfer bias should be considered when conducting and interpreting research on ischemic heart disease, particularly in rural regions.

The effects of awareness and count duration on adult respiratory rate measurements: An experimental study.

PubMed

Hill, Andrew; Kelly, Eliza; Horswill, Mark S; Watson, Marcus O

2018-02-01

To investigate whether awareness of manual respiratory rate monitoring affects respiratory rate in adults, and whether count duration influences respiratory rate estimates. Nursing textbooks typically suggest that the patient should ideally be unaware of respiratory rate observations; however, there is little published evidence of the effect of awareness on respiratory rate, and none specific to manual measurement. In addition, recommendations about the length of the respiratory rate count vary from text to text, and the relevant empirical evidence is scant, inconsistent and subject to substantial methodological limitations. Experimental study with awareness of respiration monitoring (aware, unaware; randomised between-subjects) and count duration (60 s, 30 s, 15 s; within-subjects) as the independent variables. Respiratory rate (breaths/minute) was the dependent variable. Eighty-two adult volunteers were randomly assigned to aware and unaware conditions. In the baseline block, no live monitoring occurred. In the subsequent experimental block, the researcher informed aware participants that their respiratory rate would be counted, and did so. Respirations were captured throughout via video recording, and counted by blind raters viewing 60-, 30- and 15-s extracts. The data were collected in 2015. There was no baseline difference between the groups. During the experimental block, the respiratory rates of participants in the aware condition were an average of 2.13 breaths/minute lower compared to unaware participants. Reducing the count duration from 1 min to 15 s caused respiratory rate to be underestimated by an average of 2.19 breaths/minute (and 0.95 breaths/minute for 30-s counts). The awareness effect did not depend on count duration. Awareness of monitoring appears to reduce respiratory rate, and shorter monitoring durations yield systematically lower respiratory rate estimates. When interpreting and acting upon respiratory rate data, clinicians should consider the potential influence of these factors, including cumulative effects. © 2017 The Authors. Journal of Clinical Nursing Published by John Wiley & Sons Ltd.

Real-time multi-mode neutron multiplicity counter

DOEpatents

Rowland, Mark S; Alvarez, Raymond A

2013-02-26

Embodiments are directed to a digital data acquisition method that collects data regarding nuclear fission at high rates and performs real-time preprocessing of large volumes of data into directly useable forms for use in a system that performs non-destructive assaying of nuclear material and assemblies for mass and multiplication of special nuclear material (SNM). Pulses from a multi-detector array are fed in parallel to individual inputs that are tied to individual bits in a digital word. Data is collected by loading a word at the individual bit level in parallel, to reduce the latency associated with current shift-register systems. The word is read at regular intervals, all bits simultaneously, with no manipulation. The word is passed to a number of storage locations for subsequent processing, thereby removing the front-end problem of pulse pileup. The word is used simultaneously in several internal processing schemes that assemble the data in a number of more directly useable forms. The detector includes a multi-mode counter that executes a number of different count algorithms in parallel to determine different attributes of the count data.

Position-sensitive proportional counter with low-resistance metal-wire anode

DOEpatents

Kopp, Manfred K.

1980-01-01

A position-sensitive proportional counter circuit is provided which allows the use of a conventional (low-resistance, metal-wire anode) proportional counter for spatial resolution of an ionizing event along the anode of the counter. A pair of specially designed active-capacitance preamplifiers are used to terminate the anode ends wherein the anode is treated as an RC line. The preamplifiers act as stabilized active capacitance loads and each is composed of a series-feedback, low-noise amplifier, a unity-gain, shunt-feedback amplifier whose output is connected through a feedback capacitor to the series-feedback amplifier input. The stabilized capacitance loading of the anode allows distributed RC-line position encoding and subsequent time difference decoding by sensing the difference in rise times of pulses at the anode ends where the difference is primarily in response to the distributed capacitance along the anode. This allows the use of lower resistance wire anodes for spatial radiation detection which simplifies the counter construction and handling of the anodes, and stabilizes the anode resistivity at high count rates (>10.sup.6 counts/sec).

Monitoring Oilfield Operations and GHG Emissions Sources Using Object-based Image Analysis of High Resolution Spatial Imagery

NASA Astrophysics Data System (ADS)

Englander, J. G.; Brodrick, P. G.; Brandt, A. R.

2015-12-01

Fugitive emissions from oil and gas extraction have become a greater concern with the recent increases in development of shale hydrocarbon resources. There are significant gaps in the tools and research used to estimate fugitive emissions from oil and gas extraction. Two approaches exist for quantifying these emissions: atmospheric (or 'top down') studies, which measure methane fluxes remotely, or inventory-based ('bottom up') studies, which aggregate leakage rates on an equipment-specific basis. Bottom-up studies require counting or estimating how many devices might be leaking (called an 'activity count'), as well as how much each device might leak on average (an 'emissions factor'). In a real-world inventory, there is uncertainty in both activity counts and emissions factors. Even at the well level there are significant disagreements in data reporting. For example, some prior studies noted a ~5x difference in the number of reported well completions in the United States between EPA and private data sources. The purpose of this work is to address activity count uncertainty by using machine learning algorithms to classify oilfield surface facilities using high-resolution spatial imagery. This method can help estimate venting and fugitive emissions sources from regions where reporting of oilfield equipment is incomplete or non-existent. This work will utilize high resolution satellite imagery to count well pads in the Bakken oil field of North Dakota. This initial study examines an area of ~2,000 km2 with ~1000 well pads. We compare different machine learning classification techniques, and explore the impact of training set size, input variables, and image segmentation settings to develop efficient and robust techniques identifying well pads. We discuss the tradeoffs inherent to different classification algorithms, and determine the optimal algorithms for oilfield feature detection. In the future, the results of this work will be leveraged to be provide activity counts of oilfield surface equipment including tanks, pumpjacks, and holding ponds.

Industrial metabolism of chlorine: a case study of a chlor-alkali industrial chain.

PubMed

Han, Feng; Li, Wenfeng; Yu, Fei; Cui, Zhaojie

2014-05-01

Substance flow analysis (SFA) is applied to a case study of chlorine metabolism in a chlor-alkali industrial chain. A chain-level SFA model is constructed, and eight indices are proposed to analyze and evaluate the metabolic status of elemental chlorine. The primary objectives of this study are to identify low-efficiency links in production processes and to find ways to improve the operational performance of the industrial chain. Five-year in-depth data collection and analysis revealed that system production efficiency and source efficiency continued increasing since 2008, i.e., when the chain was first formed, at average annual growth rates of 21.01 % and 1.01 %, respectively. In 2011, 64.15 % of the total chlorine input was transformed into final products. That is, as high as 98.50 % of the chlorine inputs were utilized when other by-products were counted. Chlorine loss occurred mostly in the form of chloride ions in wastewater, and the system loss rate was 0.54 %. The metabolic efficiency of chlorine in this case was high, and the chain system had minimal impact on the environment. However, from the perspectives of processing depth and economic output, the case study of a chlor-alkali industrial chain still requires expansion.

Toward Scalable Boson Sampling with Photon Loss

NASA Astrophysics Data System (ADS)

Wang, Hui; Li, Wei; Jiang, Xiao; He, Y.-M.; Li, Y.-H.; Ding, X.; Chen, M.-C.; Qin, J.; Peng, C.-Z.; Schneider, C.; Kamp, M.; Zhang, W.-J.; Li, H.; You, L.-X.; Wang, Z.; Dowling, J. P.; Höfling, S.; Lu, Chao-Yang; Pan, Jian-Wei

2018-06-01

Boson sampling is a well-defined task that is strongly believed to be intractable for classical computers, but can be efficiently solved by a specific quantum simulator. However, an outstanding problem for large-scale experimental boson sampling is the scalability. Here we report an experiment on boson sampling with photon loss, and demonstrate that boson sampling with a few photons lost can increase the sampling rate. Our experiment uses a quantum-dot-micropillar single-photon source demultiplexed into up to seven input ports of a 16 ×16 mode ultralow-loss photonic circuit, and we detect three-, four- and fivefold coincidence counts. We implement and validate lossy boson sampling with one and two photons lost, and obtain sampling rates of 187, 13.6, and 0.78 kHz for five-, six-, and seven-photon boson sampling with two photons lost, which is 9.4, 13.9, and 18.0 times faster than the standard boson sampling, respectively. Our experiment shows an approach to significantly enhance the sampling rate of multiphoton boson sampling.

Toward Scalable Boson Sampling with Photon Loss.

PubMed

Wang, Hui; Li, Wei; Jiang, Xiao; He, Y-M; Li, Y-H; Ding, X; Chen, M-C; Qin, J; Peng, C-Z; Schneider, C; Kamp, M; Zhang, W-J; Li, H; You, L-X; Wang, Z; Dowling, J P; Höfling, S; Lu, Chao-Yang; Pan, Jian-Wei

2018-06-08

Boson sampling is a well-defined task that is strongly believed to be intractable for classical computers, but can be efficiently solved by a specific quantum simulator. However, an outstanding problem for large-scale experimental boson sampling is the scalability. Here we report an experiment on boson sampling with photon loss, and demonstrate that boson sampling with a few photons lost can increase the sampling rate. Our experiment uses a quantum-dot-micropillar single-photon source demultiplexed into up to seven input ports of a 16×16 mode ultralow-loss photonic circuit, and we detect three-, four- and fivefold coincidence counts. We implement and validate lossy boson sampling with one and two photons lost, and obtain sampling rates of 187, 13.6, and 0.78 kHz for five-, six-, and seven-photon boson sampling with two photons lost, which is 9.4, 13.9, and 18.0 times faster than the standard boson sampling, respectively. Our experiment shows an approach to significantly enhance the sampling rate of multiphoton boson sampling.

Mobile HIV screening in Cape Town, South Africa: clinical impact, cost and cost-effectiveness.

PubMed

Bassett, Ingrid V; Govindasamy, Darshini; Erlwanger, Alison S; Hyle, Emily P; Kranzer, Katharina; van Schaik, Nienke; Noubary, Farzad; Paltiel, A David; Wood, Robin; Walensky, Rochelle P; Losina, Elena; Bekker, Linda-Gail; Freedberg, Kenneth A

2014-01-01

Mobile HIV screening may facilitate early HIV diagnosis. Our objective was to examine the cost-effectiveness of adding a mobile screening unit to current medical facility-based HIV testing in Cape Town, South Africa. We used the Cost Effectiveness of Preventing AIDS Complications International (CEPAC-I) computer simulation model to evaluate two HIV screening strategies in Cape Town: 1) medical facility-based testing (the current standard of care) and 2) addition of a mobile HIV-testing unit intervention in the same community. Baseline input parameters were derived from a Cape Town-based mobile unit that tested 18,870 individuals over 2 years: prevalence of previously undiagnosed HIV (6.6%), mean CD4 count at diagnosis (males 423/µL, females 516/µL), CD4 count-dependent linkage to care rates (males 31%-58%, females 49%-58%), mobile unit intervention cost (includes acquisition, operation and HIV test costs, $29.30 per negative result and $31.30 per positive result). We conducted extensive sensitivity analyses to evaluate input uncertainty. Model outcomes included site of HIV diagnosis, life expectancy, medical costs, and the incremental cost-effectiveness ratio (ICER) of the intervention compared to medical facility-based testing. We considered the intervention to be "very cost-effective" when the ICER was less than South Africa's annual per capita Gross Domestic Product (GDP) ($8,200 in 2012). We projected that, with medical facility-based testing, the discounted (undiscounted) HIV-infected population life expectancy was 132.2 (197.7) months; this increased to 140.7 (211.7) months with the addition of the mobile unit. The ICER for the mobile unit was $2,400/year of life saved (YLS). Results were most sensitive to the previously undiagnosed HIV prevalence, linkage to care rates, and frequency of HIV testing at medical facilities. The addition of mobile HIV screening to current testing programs can improve survival and be very cost-effective in South Africa and other resource-limited settings, and should be a priority.

Automating cell detection and classification in human brain fluorescent microscopy images using dictionary learning and sparse coding.

PubMed

Alegro, Maryana; Theofilas, Panagiotis; Nguy, Austin; Castruita, Patricia A; Seeley, William; Heinsen, Helmut; Ushizima, Daniela M; Grinberg, Lea T

2017-04-15

Immunofluorescence (IF) plays a major role in quantifying protein expression in situ and understanding cell function. It is widely applied in assessing disease mechanisms and in drug discovery research. Automation of IF analysis can transform studies using experimental cell models. However, IF analysis of postmortem human tissue relies mostly on manual interaction, often subjected to low-throughput and prone to error, leading to low inter and intra-observer reproducibility. Human postmortem brain samples challenges neuroscientists because of the high level of autofluorescence caused by accumulation of lipofuscin pigment during aging, hindering systematic analyses. We propose a method for automating cell counting and classification in IF microscopy of human postmortem brains. Our algorithm speeds up the quantification task while improving reproducibility. Dictionary learning and sparse coding allow for constructing improved cell representations using IF images. These models are input for detection and segmentation methods. Classification occurs by means of color distances between cells and a learned set. Our method successfully detected and classified cells in 49 human brain images. We evaluated our results regarding true positive, false positive, false negative, precision, recall, false positive rate and F1 score metrics. We also measured user-experience and time saved compared to manual countings. We compared our results to four open-access IF-based cell-counting tools available in the literature. Our method showed improved accuracy for all data samples. The proposed method satisfactorily detects and classifies cells from human postmortem brain IF images, with potential to be generalized for applications in other counting tasks. Copyright © 2017 Elsevier B.V. All rights reserved.

Development of the U.S. Army Railroad Track Maintenance Management System (RAILER).

DTIC Science & Technology

1986-05-01

availability is both feasible and desirable. Section 5 of this study discusses measurement and analysis equipment. .5 *- Sample Deduct Value Calculations... Sample of Five Groups of 50 Ties From Same Mile on Track 72 C2 Bad Tie Count Adjustment Factors 80 C3 Adjusted Badtie Count Factors Under Conservative...economic analysis developed as part of the PAVER system 3 can be used for RAILER; however, guidelines for providing track information inputs to the

Photon Counting Detectors for the 1.0 - 2.0 Micron Wavelength Range

NASA Technical Reports Server (NTRS)

Krainak, Michael A.

2004-01-01

We describe results on the development of greater than 200 micron diameter, single-element photon-counting detectors for the 1-2 micron wavelength range. The technical goals include quantum efficiency in the range 10-70%; detector diameter greater than 200 microns; dark count rate below 100 kilo counts-per-second (cps), and maximum count rate above 10 Mcps.

Integration of manatee life-history data and population modeling

USGS Publications Warehouse

Eberhardt, L.L.; O'Shea, Thomas J.; O'Shea, Thomas J.; Ackerman, B.B.; Percival, H. Franklin

1995-01-01

Aerial counts and the number of deaths have been a major focus of attention in attempts to understand the population status of the Florida manatee (Trichechus manatus latirostris). Uncertainties associated with these data have made interpretation difficult. However, knowledge of manatee life-history attributes increased and now permits the development of a population model. We describe a provisional model based on the classical approach of Lotka. Parameters in the model are based on data from'other papers in this volume and draw primarily on observations from the Crystal River, Blue Spring, and Adantic Coast areas. The model estimates X (the finite rate ofincrease) at each study area, and application ofthe delta method provides estimates of variance components and partial derivatives ofX with respectto key input parameters (reproduction, adult survival, and early survival). In some study areas, only approximations of some parameters are available. Estimates of X and coefficients of variation (in parentheses) of manatees were 1.07 (0.009) in the Crystal River, 1.06 (0.012) at Blue Spring, and 1.01 (0.012) on the Atlantic Coast. Changing adult survival has a major effect on X. Early-age survival has the smallest effect. Bootstrap comparisons of population growth estimates from trend counts in the Crystal River and at Blue Spring and the reproduction and survival data suggest that the higher, observed rates from counts are probably not due to chance. Bootstrapping for variance estimates based on reproduction and survival data from manatees at Blue Spring and in the Crystal River provided estimates of X, adult survival, and rates of reproduction that were similar to those obtained by other methods. Our estimates are preliminary and suggestimprovements for future data collection and analysis. However, results support efforts to reduce mortality as the most effective means to promote the increased growth necessary for the eventual recovery of the Florida manatee population.

JUNGFRAU 0.2: prototype characterization of a gain-switching, high dynamic range imaging system for photon science at SwissFEL and synchrotrons

NASA Astrophysics Data System (ADS)

Jungmann-Smith, J. H.; Bergamaschi, A.; Cartier, S.; Dinapoli, R.; Greiffenberg, D.; Johnson, I.; Maliakal, D.; Mezza, D.; Mozzanica, A.; Ruder, Ch; Schaedler, L.; Schmitt, B.; Shi, X.; Tinti, G.

2014-12-01

JUNGFRAU (adJUstiNg Gain detector FoR the Aramis User station) is a two-dimensional pixel detector for photon science applications at free electron lasers and synchrotron light sources. It is developed for the SwissFEL currently under construction at the Paul Scherrer Institute, Switzerland. Characteristics of this application-specific integrating circuit readout chip include single photon sensitivity and low noise over a dynamic range of over four orders of magnitude of photon input signal. These characteristics are achieved by a three-fold gain-switching preamplifier in each pixel, which automatically adjusts its gain to the amount of charge deposited on the pixel. The final JUNGFRAU chip comprises 256 × 256 pixels of 75 × 75 μm2 each. Arrays of 2 × 4 chips are bump-bonded to monolithic detector modules of about 4 × 8 cm2. Multi-module systems up to 16 Mpixels are planned for the end stations at SwissFEL. A readout rate in excess of 2 kHz is anticipated, which serves the readout requirements of SwissFEL and enables high count rate synchrotron experiments with a linear count rate capability of > 20 MHz/pixel. Promising characterization results from a 3.6 × 3.6 mm2 prototype (JUNGFRAU 0.2) with fluorescence X-ray, infrared laser and synchrotron irradiation are shown. The results include an electronic noise as low as 100 electrons root-mean-square, which enables single photon detection down to X-ray energies of about 2 keV. Noise below the Poisson fluctuation of the photon number and a linearity error of the pixel response of about 1% are demonstrated. First imaging experiments successfully show automatic gain switching. The edge spread function of the imaging system proves to be comparable in quality to single photon counting hybrid pixel detectors.

500-514 N. Peshtigo Ct, May 2018, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

maximum gamma count rate for each lift was recorded on the attached RadiationSurvey Forms. Count rates in the excavation ranged from 1,800 cpm - 5,000 cpm.No count rates were found at any time that exceeded the instrument specific thresholdlimits.

550 E. Illinois, May 2018, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

Maximum gamma count rate for each lift was recorded on the attached RadiationSurvey Forms. Count rates in the excavation ranged from 1,250 cpm to 4,880 cpm.No count rates were found at any time that exceeded the instrument specific thresholdlimits.

Quantitative Electron-Excited X-Ray Microanalysis of Borides, Carbides, Nitrides, Oxides, and Fluorides with Scanning Electron Microscopy/Silicon Drift Detector Energy-Dispersive Spectrometry (SEM/SDD-EDS) and NIST DTSA-II.

PubMed

Newbury, Dale E; Ritchie, Nicholas W M

2015-10-01

A scanning electron microscope with a silicon drift detector energy-dispersive X-ray spectrometer (SEM/SDD-EDS) was used to analyze materials containing the low atomic number elements B, C, N, O, and F achieving a high degree of accuracy. Nearly all results fell well within an uncertainty envelope of ±5% relative (where relative uncertainty (%)=[(measured-ideal)/ideal]×100%). Quantification was performed with the standards-based "k-ratio" method with matrix corrections calculated based on the Pouchou and Pichoir expression for the ionization depth distribution function, as implemented in the NIST DTSA-II EDS software platform. The analytical strategy that was followed involved collection of high count (>2.5 million counts from 100 eV to the incident beam energy) spectra measured with a conservative input count rate that restricted the deadtime to ~10% to minimize coincidence effects. Standards employed included pure elements and simple compounds. A 10 keV beam was employed to excite the K- and L-shell X-rays of intermediate and high atomic number elements with excitation energies above 3 keV, e.g., the Fe K-family, while a 5 keV beam was used for analyses of elements with excitation energies below 3 keV, e.g., the Mo L-family.

Compensated count-rate circuit for radiation survey meter

DOEpatents

Todd, R.A.

1980-05-12

A count-rate compensating circuit is provided which may be used in a portable Geiger-Mueller (G-M) survey meter to ideally compensate for couting loss errors in the G-M tube detector. In a G-M survey meter, wherein the pulse rate from the G-M tube is converted into a pulse rate current applied to a current meter calibrated to indicate dose rate, the compensation circuit generates and controls a reference voltage in response to the rate of pulses from the detector. This reference voltage is gated to the current-generating circuit at a rate identical to the rate of pulses coming from the detector so that the current flowing through the meter is varied in accordance with both the frequency and amplitude of the reference voltage pulses applied thereto so that the count rate is compensated ideally to indicate a true count rate within 1% up to a 50% duty cycle for the detector. A positive feedback circuit is used to control the reference voltage so that the meter output tracks true count rate indicative of the radiation dose rate.

Method and apparatus for digitally based high speed x-ray spectrometer for direct coupled use with continuous discharge preamplifiers

DOEpatents

Warburton, W.K.

1998-06-30

A high speed, digitally based, signal processing system is disclosed which accepts directly coupled input data from a detector with a continuous discharge type preamplifier and produces a spectral analysis of the x-rays illuminating the detector. The system`s principal elements are an analog signal conditioning section, a combinatorial logic section which implements digital triangular filtering and pileup inspection, and a microprocessor which accepts values captured by the logic section and uses them to compute x-ray energy values. Operating without pole-zero correction, the system achieves high resolution by capturing, in conjunction with each peak value from the digital filter, an associated value of the unfiltered signal, and using this latter signal to correct the former for errors which arise from its local slope terms. This correction greatly reduces both energy resolution degradation and peak centroid shifting in the output spectrum as a function of input count rate. When the noise of this correction is excessive, a modification allows two filtered averages of the signal to be captured and a corrected peak amplitude computed therefrom. 14 figs.

Method and apparatus for digitally based high speed x-ray spectrometer for direct coupled use with continuous discharge preamplifiers

DOEpatents

Warburton, William K.

1998-01-01

A high speed, digitally based, signal processing system which accepts directly coupled input data from a detector with a continuous discharge type preamplifier and produces a spectral analysis of the x-rays illuminating the detector. The system's principal elements are an analog signal conditioning section, a combinatorial logic section which implements digital triangular filtering and pileup inspection, and a microprocessor which accepts values captured by the logic section and uses them to compute x-ray energy values. Operating without pole-zero correction, the system achieves high resolution by capturing, in conjunction with each peak value from the digital filter, an associated value of the unfiltered signal, and using this latter signal to correct the former for errors which arise from its local slope terms. This correction greatly reduces both energy resolution degradation and peak centroid shifting in the output spectrum as a function of input count rate. When the noise of this correction is excessive, a modification allows two filtered averages of the signal to be captured and a corrected peak amplitude computed therefrom.

Note: Operation of gamma-ray microcalorimeters at elevated count rates using filters with constraints

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

Alpert, B. K.; Horansky, R. D.; Bennett, D. A.

Microcalorimeter sensors operated near 0.1 K can measure the energy of individual x- and gamma-ray photons with significantly more precision than conventional semiconductor technologies. Both microcalorimeter arrays and higher per pixel count rates are desirable to increase the total throughput of spectrometers based on these devices. The millisecond recovery time of gamma-ray microcalorimeters and the resulting pulse pileup are significant obstacles to high per pixel count rates. Here, we demonstrate operation of a microcalorimeter detector at elevated count rates by use of convolution filters designed to be orthogonal to the exponential tail of a preceding pulse. These filters allow operationmore » at 50% higher count rates than conventional filters while largely preserving sensor energy resolution.« less

Utilizing Dynamically Coupled Cores to Form a Resilient Chip Multiprocessor

DTIC Science & Technology

2007-06-01

requires a significant deviation from previous work. For instance, we find that using the relaxed input replication model from Reunion incurs a...Circuit Width Delay Count CRC-16 16 6.65 754 CRC- SDLC -16 16 6.10 888 CRC-32 16 7.28 2260 CRC-32 32 8.60 4240 Table 1. FO4 delay and transistor count for...the operation of our proposed system is the same in all other respects. 4.4 Compatibility Across Memory Consis- tency Models The memory consistency

Cryogenic, high-resolution x-ray detector with high count rate capability

DOEpatents

Frank, Matthias; Mears, Carl A.; Labov, Simon E.; Hiller, Larry J.; Barfknecht, Andrew T.

2003-03-04

A cryogenic, high-resolution X-ray detector with high count rate capability has been invented. The new X-ray detector is based on superconducting tunnel junctions (STJs), and operates without thermal stabilization at or below 500 mK. The X-ray detector exhibits good resolution (.about.5-20 eV FWHM) for soft X-rays in the keV region, and is capable of counting at count rates of more than 20,000 counts per second (cps). Simple, FET-based charge amplifiers, current amplifiers, or conventional spectroscopy shaping amplifiers can provide the electronic readout of this X-ray detector.

Input current shaped ac-to-dc converters

NASA Technical Reports Server (NTRS)

1985-01-01

Input current shaping techniques for ac-to-dc converters were investigated. Input frequencies much higher than normal, up to 20 kHz were emphasized. Several methods of shaping the input current waveform in ac-to-dc converters were reviewed. The simplest method is the LC filter following the rectifier. The next simplest method is the resistor emulation approach in which the inductor size is determined by the converter switching frequency and not by the line input frequency. Other methods require complicated switch drive algorithms to construct the input current waveshape. For a high-frequency line input, on the order of 20 kHz, the simple LC cannot be discarded so peremptorily, since the inductor size can be compared with that for the resistor emulation method. In fact, since a dc regulator will normally be required after the filter anyway, the total component count is almost the same as for the resistor emulation method, in which the filter is effectively incorporated into the regulator.

Noise Characterization of Erbium-Doped Fiber Amplifiers and Avalanche Photodiodes in Optical Communication Systems.

NASA Astrophysics Data System (ADS)

Kahraman, Gokalp

We examine the performance of optical communication systems using erbium-doped fiber amplifiers (OFAs) and avalanche photodiodes (APDs) including nonlinear and transient effects in the former and transient effects in the latter. Transient effects become important as these amplifiers are operated at very high data rates. Nonlinear effects are important for high gain amplifiers. In most studies of noise in these devices, the temporal and nonlinear effects have been ignored. We present a quantum theory of noise in OFAs including the saturation of the atomic population inversion and the pump depletion. We study the quantum-statistical properties of pulse amplification. The generating function of the output photon number distribution (PND) is determined as a function of time during the course of the pulse with an arbitrary input PND assumed. Under stationary conditions, we determine the Kolmogorov equation obeyed by the PND. The PND at the output is determined for arbitrary input distributions. The effect of the counting time and the filter bandwidth used by the detection circuit is determined. We determine the gain, the noise figure, and the sensitivity of receivers using OFAs as preamplifiers, including the effect of backward amplified spontaneous emission (ASE). Backward ASE degrades the noise figure and the sensitivity by depleting the population inversion at the input side of the fiber and thus increasing the noise during signal amplification. We show that the sensitivity improves with the bit rate at low rates but degrades at high rates. We provide a stochastic model that describes the time dynamics in a double-carrier multiplication (DCM) APD. A discrete stochastic model for the electron/hole motion and multiplication is defined on a spatio-temporal lattice and used to derive recursive equations for the mean, the variance, and the autocorrelation of the impulse response as functions of time. The power spectral density of the photocurrent produced in response to a Poisson-distributed stream of photons of uniform rate is evaluated. A method is also developed for solving the coupled transport equations that describe the electron and hole currents in a DCM-APD of arbitrary structure.

Alice Solar Occultation

NASA Image and Video Library

2015-07-17

This figure shows how the Alice instrument count rate changed over time during the sunset and sunrise observations. The count rate is largest when the line of sight to the sun is outside of the atmosphere at the start and end times. Molecular nitrogen (N2) starts absorbing sunlight in the upper reaches of Pluto's atmosphere, decreasing as the spacecraft approaches the planet's shadow. As the occultation progresses, atmospheric methane and hydrocarbons can also absorb the sunlight and further decrease the count rate. When the spacecraft is totally in Pluto's shadow the count rate goes to zero. As the spacecraft emerges from Pluto's shadow into sunrise, the process is reversed. By plotting the observed count rate in the reverse time direction, it is seen that the atmospheres on opposite sides of Pluto are nearly identical. http://photojournal.jpl.nasa.gov/catalog/PIA19716

Uptake Index of 123I-metaiodobenzylguanidine Myocardial Scintigraphy for Diagnosing Lewy Body Disease

PubMed Central

Kamiya, Yoshito; Ota, Satoru; Okumiya, Shintaro; Yamashita, Kosuke; Takaki, Akihiro; Ito, Shigeki

2017-01-01

Objective(s): Iodine-123 metaiodobenzylguanidine (123I-MIBG) myocardial scintigraphy has been used to evaluate cardiac sympathetic denervation in Lewy body disease (LBD), including Parkinson’s disease (PD) and dementia with Lewy bodies (DLB). The heart-to-mediastinum ratio (H/M) in PD and DLB is significantly lower than that in Parkinson’s plus syndromes and Alzheimer’s disease. Although this ratio is useful for distinguishing LBD from non-LBD, it fluctuates depending on the system performance of the gamma cameras. Therefore, a new, simple quantification method using 123I-MIBG uptake analysis is required for clinical study. The purpose of this study was to develop a new uptake index with a simple protocol to determine 123I-MIBG uptake on planar images. Methods: The 123I-MIBG input function was obtained from the input counts of the pulmonary artery (PA), which were assessed by analyzing the PA time-activity curves. The heart region of interest used for determining the H/M was used for calculating the uptake index, which was obtained by dividing the heart count by the input count. Results: Forty-eight patients underwent 123I-MIBG chest angiography and planar imaging, after clinical feature assessment and tracer injection. The H/M and 123I-MIBG uptake index were calculated and correlated with clinical features. Values for LBD were significantly lower than those for non-LBD in all analyses (P<0.001). The overlapping ranges between non-LBD and LBD were 2.15 to 2.49 in the H/M method, and 1.04 to 1.22% in the uptake index method. The diagnostic accuracy of the uptake index (area under the curve (AUC), 0.98; sensitivity, 96%; specificity, 91%; positive predictive value (PPV), 90%; negative predictive value (NPV), 93%; and accuracy, 92%) was approximately equal to that of the H/M (AUC, 0.95; sensitivity, 93%; specificity, 91%; PPV, 90%; NPV, 93%; and accuracy, 92%) for discriminating patients with LBD and non-LBD. Conclusion: A simple uptake index method was developed using 123I-MIBG planar imaging and the input counts determined by analyzing chest radioisotope angiography images of the PA. The diagnostic accuracy of the uptake index was approximately equal to that of the H/M for discriminating patients with LBD and non-LBD. PMID:28840137

Kids Count in Indiana: 1996 Data Book.

ERIC Educational Resources Information Center

Erickson, Judith B.

This Kids Count report is the third in a series examining statewide trends in the well-being of Indiana's children. The report combines statistics of special concern in Indiana with 10 national Kids Count well-being indicators: (1) percent low birthweight; (2) infant mortality rate; (3) child death rate; (4) birth rate to unmarried teens ages 15…

Automating Cell Detection and Classification in Human Brain Fluorescent Microscopy Images Using Dictionary Learning and Sparse Coding

PubMed Central

Alegro, Maryana; Theofilas, Panagiotis; Nguy, Austin; Castruita, Patricia A.; Seeley, William; Heinsen, Helmut; Ushizima, Daniela M.

2017-01-01

Background Immunofluorescence (IF) plays a major role in quantifying protein expression in situ and understanding cell function. It is widely applied in assessing disease mechanisms and in drug discovery research. Automation of IF analysis can transform studies using experimental cell models. However, IF analysis of postmortem human tissue relies mostly on manual interaction, often subjected to low-throughput and prone to error, leading to low inter and intra-observer reproducibility. Human postmortem brain samples challenges neuroscientists because of the high level of autofluorescence caused by accumulation of lipofuscin pigment during aging, hindering systematic analyses. We propose a method for automating cell counting and classification in IF microscopy of human postmortem brains. Our algorithm speeds up the quantification task while improving reproducibility. New method Dictionary learning and sparse coding allow for constructing improved cell representations using IF images. These models are input for detection and segmentation methods. Classification occurs by means of color distances between cells and a learned set. Results Our method successfully detected and classified cells in 49 human brain images. We evaluated our results regarding true positive, false positive, false negative, precision, recall, false positive rate and F1 score metrics. We also measured user-experience and time saved compared to manual countings. Comparison with existing methods We compared our results to four open-access IF-based cell-counting tools available in the literature. Our method showed improved accuracy for all data samples. Conclusion The proposed method satisfactorily detects and classifies cells from human postmortem brain IF images, with potential to be generalized for applications in other counting tasks. PMID:28267565

A state comparison amplifier with feed forward state correction

NASA Astrophysics Data System (ADS)

Mazzarella, Luca; Donaldson, Ross; Collins, Robert; Zanforlin, Ugo; Buller, Gerald; Jeffers, John

2017-04-01

The Quantum State Comparison AMPlifier (SCAMP) is a probabilistic amplifier that works for known sets of coherent states. The input state is mixed with a guess state at a beam splitter and one of the output ports is coupled to a detector. The other output contains the amplified state, which is accepted on the condition that no counts are recorded. The system uses only classical resources and has been shown to achieve high gain and repetition rate. However the output fidelity is not high enough for most quantum communication purposes. Here we show how the success probability and fidelity are enhanced by repeated comparison stages, conditioning later state choices on the outcomes of earlier detections. A detector firing at an early stage means that a guess is wrong. This knowledge allows us to correct the state perfectly. The system requires fast-switching between different input states, but still requires only classical resources. Figures of merit compare favourably with other schemes, most notably the probability-fidelity product is higher than for unambiguous state discrimination. Due to its simplicity, the system is a candidate to counteract quantum signal degradation in a lossy fibre or as a quantum receiver to improve the key rate of continuous variable quantum communication. The work was supported by the QComm Project of the UK Engineering and Physical Sciences Research Council (EP/M013472/1).

Counting-loss correction for X-ray spectroscopy using unit impulse pulse shaping.

PubMed

Hong, Xu; Zhou, Jianbin; Ni, Shijun; Ma, Yingjie; Yao, Jianfeng; Zhou, Wei; Liu, Yi; Wang, Min

2018-03-01

High-precision measurement of X-ray spectra is affected by the statistical fluctuation of the X-ray beam under low-counting-rate conditions. It is also limited by counting loss resulting from the dead-time of the system and pile-up pulse effects, especially in a high-counting-rate environment. In this paper a detection system based on a FAST-SDD detector and a new kind of unit impulse pulse-shaping method is presented, for counting-loss correction in X-ray spectroscopy. The unit impulse pulse-shaping method is evolved by inverse deviation of the pulse from a reset-type preamplifier and a C-R shaper. It is applied to obtain the true incoming rate of the system based on a general fast-slow channel processing model. The pulses in the fast channel are shaped to unit impulse pulse shape which possesses small width and no undershoot. The counting rate in the fast channel is corrected by evaluating the dead-time of the fast channel before it is used to correct the counting loss in the slow channel.

Digital computing cardiotachometer

NASA Technical Reports Server (NTRS)

Smith, H. E.; Rasquin, J. R.; Taylor, R. A. (Inventor)

1973-01-01

A tachometer is described which instantaneously measures heart rate. During the two intervals between three succeeding heart beats, the electronic system: (1) measures the interval by counting cycles from a fixed frequency source occurring between the two beats; and (2) computes heat rate during the interval between the next two beats by counting the number of times that the interval count must be counted to zero in order to equal a total count of sixty times (to convert to beats per minute) the frequency of the fixed frequency source.

Development of microchannel plates in advanced wind-tunnel instrumentation

NASA Technical Reports Server (NTRS)

Feller, W. Bruce

1990-01-01

Microchannel plate (MCP) electron multiplier dynamic range has been increased 3 to 4 orders of magnitude at ambient temperatures, through enhanced input count rate capability and reduced background or 'dark' noise. The previous upper limit of roughly 10(exp 7) - 10(exp 8) cm(exp -2)s(exp -1) at ambient has been extended to levels approach 10(exp 10) cm(exp -2)s(exp -1) under continuous dc operation. The lower limit, previously set by an irreducible background component (approximately 0.6 cm(exp -2)s(exp -1)), has been lowered to the cosmic ray limit of .01 cm(exp -2)s(exp -1). The high end improvement was achieved by conductively cooling a very low resistance MCP by bonding it to a heat sink, while maintaining pulse-counting operation with multianode readouts. The low-end improvement was achieved by removing all radioisotopes from the MCP matrix glass. The detectors will benefit optical and mass spectrometry, flow visualization, plasma diagnostics, magnetometry, and other high signal flux applications. Very low MCP background noise will benefit X-ray and UV astronomy, medical imaging, trace isotope mass spectrometry, and other applications where the signal flux is often extremely low.

Interdependent effects of sound duration and amplitude on neuronal onset response in mice inferior colliculus.

PubMed

Wang, Ningqian; Wang, Xiao; Yang, Xiaoli; Tang, Jie; Xiao, Zhongju

2014-01-16

In this study, we adopted iso-frequency pure tone bursts to investigate the interdependent effects of sound amplitude/intensity and duration on mice inferior colliculus (IC) neuronal onset responses. On the majority of the sampled neurons (n=57, 89.1%), sound amplitude and duration had effects on the neuronal response to each other by showing complex changes of the rat-intensity function/duration selectivity types and/or best amplitudes (BAs)/durations (BDs), evaluated by spike counts. These results suggested that the balance between the excitatory and inhibitory inputs set by one acoustic parameter, amplitude or duration, affected the neuronal spike counts responses to the other. Neuronal duration selectivity types were altered easily by the low-amplitude sounds while the changes of rate-intensity function types had no obvious preferred stimulus durations. However, the first spike latencies (FSLs) of the onset response neurons were relative stable to iso-amplitude sound durations and changing systematically along with the sound levels. The superimposition of FSL and duration threshold (DT) as a function of stimulus amplitude after normalization indicated that the effects of the sound levels on FSLs are considered on DT actually. © 2013 Published by Elsevier B.V.

A simulation model for studying the role of pre-slaughter factors on the exposure of beef carcasses to human microbial hazards.

PubMed

Jordan, D; McEwen, S A; Lammerding, A M; McNab, W B; Wilson, J B

1999-06-29

A Monte Carlo simulation model was constructed for assessing the quantity of microbial hazards deposited on cattle carcasses under different pre-slaughter management regimens. The model permits comparison of industry-wide and abattoir-based mitigation strategies and is suitable for studying pathogens such as Escherichia coli O157:H7 and Salmonella spp. Simulations are based on a hierarchical model structure that mimics important aspects of the cattle population prior to slaughter. Stochastic inputs were included so that uncertainty about important input assumptions (such as prevalence of a human pathogen in the live cattle-population) would be reflected in model output. Control options were built into the model to assess the benefit of having prior knowledge of animal or herd-of-origin pathogen status (obtained from the use of a diagnostic test). Similarly, a facility was included for assessing the benefit of re-ordering the slaughter sequence based on the extent of external faecal contamination. Model outputs were designed to evaluate the performance of an abattoir in a 1-day period and included outcomes such as the proportion of carcasses contaminated with a pathogen, the daily mean and selected percentiles of pathogen counts per carcass, and the position of the first infected animal in the slaughter run. A measure of the time rate of introduction of pathogen into the abattoir was provided by assessing the median, 5th percentile, and 95th percentile cumulative pathogen counts at 10 equidistant points within the slaughter run. Outputs can be graphically displayed as frequency distributions, probability densities, cumulative distributions or x-y plots. The model shows promise as an inexpensive method for evaluating pathogen control strategies such as those forming part of a Hazard Analysis and Critical Control Point (HACCP) system.

Estimation of low-level neutron dose-equivalent rate by using extrapolation method for a curie level Am-Be neutron source.

PubMed

Li, Gang; Xu, Jiayun; Zhang, Jie

2015-01-01

Neutron radiation protection is an important research area because of the strong radiation biological effect of neutron field. The radiation dose of neutron is closely related to the neutron energy, and the connected relationship is a complex function of energy. For the low-level neutron radiation field (e.g. the Am-Be source), the commonly used commercial neutron dosimeter cannot always reflect the low-level dose rate, which is restricted by its own sensitivity limit and measuring range. In this paper, the intensity distribution of neutron field caused by a curie level Am-Be neutron source was investigated by measuring the count rates obtained through a 3 He proportional counter at different locations around the source. The results indicate that the count rates outside of the source room are negligible compared with the count rates measured in the source room. In the source room, 3 He proportional counter and neutron dosimeter were used to measure the count rates and dose rates respectively at different distances to the source. The results indicate that both the count rates and dose rates decrease exponentially with the increasing distance, and the dose rates measured by a commercial dosimeter are in good agreement with the results calculated by the Geant4 simulation within the inherent errors recommended by ICRP and IEC. Further studies presented in this paper indicate that the low-level neutron dose equivalent rates in the source room increase exponentially with the increasing low-energy neutron count rates when the source is lifted from the shield with different radiation intensities. Based on this relationship as well as the count rates measured at larger distance to the source, the dose rates can be calculated approximately by the extrapolation method. This principle can be used to estimate the low level neutron dose values in the source room which cannot be measured directly by a commercial dosimeter. Copyright © 2014 Elsevier Ltd. All rights reserved.

Fast counting electronics for neutron coincidence counting

DOEpatents

Swansen, James E.

1987-01-01

An amplifier-discriminator is tailored to output a very short pulse upon an above-threshold input from a detector which may be a .sup.3 He detector. The short pulse output is stretched and energizes a light emitting diode (LED) to provide a visual output of operation and pulse detection. The short pulse is further fed to a digital section for processing and possible ORing with other like generated pulses. Finally, the output (or ORed output ) is fed to a derandomizing buffer which converts the rapidly and randomly occurring pulses into synchronized and periodically spaced-apart pulses for the accurate counting thereof. Provision is also made for the internal and external disabling of each individual channel of amplifier-discriminators in an ORed plurality of same.

Fast counting electronics for neutron coincidence counting

DOEpatents

Swansen, J.E.

1985-03-05

An amplifier-discriminator is tailored to output a very short pulse upon an above-threshold input from a detector which may be a /sup 3/He detector. The short pulse output is stretched and energizes a light emitting diode (LED) to provide a visual output of operation and pulse detection. The short pulse is further fed to a digital section for processing and possible ORing with other like generated pulses. Finally, the output (or ORed output) is fed to a derandomizing buffer which converts the rapidly and randomly occurring pulses into synchronized and periodically spaced-apart pulses for the accurate counting thereof. Provision is also made for the internal and external disabling of each individual channel of amplifier-discriminators in an ORed plurality of same.

A Dasymetric-Based Monte Carlo Simulation Approach to the Probabilistic Analysis of Spatial Variables

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

Morton, April M; Piburn, Jesse O; McManamay, Ryan A

2017-01-01

Monte Carlo simulation is a popular numerical experimentation technique used in a range of scientific fields to obtain the statistics of unknown random output variables. Despite its widespread applicability, it can be difficult to infer required input probability distributions when they are related to population counts unknown at desired spatial resolutions. To overcome this challenge, we propose a framework that uses a dasymetric model to infer the probability distributions needed for a specific class of Monte Carlo simulations which depend on population counts.

Pneumotachometer counts respiration rate of human subject

NASA Technical Reports Server (NTRS)

Graham, O.

1964-01-01

To monitor breaths per minute, two rate-to-analog converters are alternately used to read and count the respiratory rate from an impedance pneumograph sequentially displayed numerically on electroluminescent matrices.

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

Duchaineau, M.; Wolinsky, M.; Sigeti, D.E.

Terrain visualization is a difficult problem for applications requiring accurate images of large datasets at high frame rates, such as flight simulation and ground-based aircraft testing using synthetic sensor stimulation. On current graphics hardware, the problem is to maintain dynamic, view-dependent triangle meshes and texture maps that produce good images at the required frame rate. We present an algorithm for constructing triangle meshes that optimizes flexible view-dependent error metrics, produces guaranteed error bounds, achieves specified triangle counts directly, and uses frame-to-frame coherence to operate at high frame rates for thousands of triangles per frame. Our method, dubbed Real-time Optimally Adaptingmore » Meshes (ROAM), uses two priority queues to drive split and merge operations that maintain continuous triangulations built from pre-processed bintree triangles. We introduce two additional performance optimizations: incremental triangle stripping and priority-computation deferral lists. ROAM execution time is proportionate to the number of triangle changes per frame, which is typically a few percent of the output mesh size, hence ROAM performance is insensitive to the resolution and extent of the input terrain. Dynamic terrain and simple vertex morphing are supported.« less

Modeling and performance metrics of MIMO-SDM systems with different amplification schemes in the presence of mode-dependent loss.

PubMed

Antonelli, Cristian; Mecozzi, Antonio; Shtaif, Mark; Winzer, Peter J

2015-02-09

Mode-dependent loss (MDL) is a major factor limiting the achievable information rate in multiple-input multiple-output space-division multiplexed systems. In this paper we show that its impact on system performance, which we quantify in terms of the capacity reduction relative to a reference MDL-free system, may depend strongly on the operation of the inline optical amplifiers. This dependency is particularly strong in low mode-count systems. In addition, we discuss ways in which the signal-to-noise ratio of the MDL-free reference system can be defined and quantify the differences in the predicted capacity loss. Finally, we stress the importance of correctly accounting for the effect of MDL on the accumulation of amplification noise.

ERA: Adverse Consequences

ERIC Educational Resources Information Center

Martin, Brian

2011-01-01

Excellence in Research for Australia has a number of limitations: inputs are counted as outputs, time is wasted, disciplinary research is favoured and public engagement is discouraged. Most importantly, by focusing on measurement and emphasising competition, ERA may actually undermine the cooperation and intrinsic motivation that underpin research…

QNB: differential RNA methylation analysis for count-based small-sample sequencing data with a quad-negative binomial model.

PubMed

Liu, Lian; Zhang, Shao-Wu; Huang, Yufei; Meng, Jia

2017-08-31

As a newly emerged research area, RNA epigenetics has drawn increasing attention recently for the participation of RNA methylation and other modifications in a number of crucial biological processes. Thanks to high throughput sequencing techniques, such as, MeRIP-Seq, transcriptome-wide RNA methylation profile is now available in the form of count-based data, with which it is often of interests to study the dynamics at epitranscriptomic layer. However, the sample size of RNA methylation experiment is usually very small due to its costs; and additionally, there usually exist a large number of genes whose methylation level cannot be accurately estimated due to their low expression level, making differential RNA methylation analysis a difficult task. We present QNB, a statistical approach for differential RNA methylation analysis with count-based small-sample sequencing data. Compared with previous approaches such as DRME model based on a statistical test covering the IP samples only with 2 negative binomial distributions, QNB is based on 4 independent negative binomial distributions with their variances and means linked by local regressions, and in the way, the input control samples are also properly taken care of. In addition, different from DRME approach, which relies only the input control sample only for estimating the background, QNB uses a more robust estimator for gene expression by combining information from both input and IP samples, which could largely improve the testing performance for very lowly expressed genes. QNB showed improved performance on both simulated and real MeRIP-Seq datasets when compared with competing algorithms. And the QNB model is also applicable to other datasets related RNA modifications, including but not limited to RNA bisulfite sequencing, m 1 A-Seq, Par-CLIP, RIP-Seq, etc.

Dynamic range considerations for EUV MAMA detectors. [Extreme UV Multianode Microchannel Array

NASA Technical Reports Server (NTRS)

Illing, Rainer M. E.; Bybee, Richard L.; Timothy, J. G.

1990-01-01

The multianode microchannel array (MAMA) has been chosen as the detector for two instruments on the ESA/NASA Solar Heliospheric Observatory. The response of the MAMA to the two extreme types of solar spectra, disk and corona, have been modeled with a view toward evaluating dynamic range effects present. The method of MAMA operation is discussed, with emphasis given to modeling the effect of electron cloud charge spreading to several detector anodes and amplifiers (n-fold events). Representative synthetic EUV spectra have been created. The detector response to these spectra is modeled by dissecting the input photon radiation field across the detector array into contributions to the various amplifier channels. The results of this dissection are shown for spectral regions across the entire wavelength region of interest. These results are used to identify regions in which total array photon counting rate or individual amplifier rate may exceed the design limits. This allows the design or operational modes to be tailored to eliminate the problem areas.

Can simple mobile phone applications provide reliable counts of respiratory rates in sick infants and children? An initial evaluation of three new applications.

PubMed

Black, James; Gerdtz, Marie; Nicholson, Pat; Crellin, Dianne; Browning, Laura; Simpson, Julie; Bell, Lauren; Santamaria, Nick

2015-05-01

Respiratory rate is an important sign that is commonly either not recorded or recorded incorrectly. Mobile phone ownership is increasing even in resource-poor settings. Phone applications may improve the accuracy and ease of counting of respiratory rates. The study assessed the reliability and initial users' impressions of four mobile phone respiratory timer approaches, compared to a 60-second count by the same participants. Three mobile applications (applying four different counting approaches plus a standard 60-second count) were created using the Java Mobile Edition and tested on Nokia C1-01 phones. Apart from the 60-second timer application, the others included a counter based on the time for ten breaths, and three based on the time interval between breaths ('Once-per-Breath', in which the user presses for each breath and the application calculates the rate after 10 or 20 breaths, or after 60s). Nursing and physiotherapy students used the applications to count respiratory rates in a set of brief video recordings of children with different respiratory illnesses. Limits of agreement (compared to the same participant's standard 60-second count), intra-class correlation coefficients and standard errors of measurement were calculated to compare the reliability of the four approaches, and a usability questionnaire was completed by the participants. There was considerable variation in the counts, with large components of the variation related to the participants and the videos, as well as the methods. None of the methods was entirely reliable, with no limits of agreement better than -10 to +9 breaths/min. Some of the methods were superior to the others, with ICCs from 0.24 to 0.92. By ICC the Once-per-Breath 60-second count and the Once-per-Breath 20-breath count were the most consistent, better even than the 60-second count by the participants. The 10-breath approaches performed least well. Users' initial impressions were positive, with little difference between the applications found. This study provides evidence that applications running on simple phones can be used to count respiratory rates in children. The Once-per-Breath methods are the most reliable, outperforming the 60-second count. For children with raised respiratory rates the 20-breath version of the Once-per-Breath method is faster, so it is a more suitable option where health workers are under time pressure. Copyright © 2015 Elsevier Ltd. All rights reserved.

Cerebellar pathology in childhood-onset vs. adult-onset essential tremor.

PubMed

Louis, Elan D; Kuo, Sheng-Han; Tate, William J; Kelly, Geoffrey C; Faust, Phyllis L

2017-10-17

Although the incidence of ET increases with advancing age, the disease may begin at any age, including childhood. The question arises as to whether childhood-onset ET cases manifest the same sets of pathological changes in the cerebellum as those whose onset is during adult life. We quantified a broad range of postmortem features (Purkinje cell [PC] counts, PC axonal torpedoes, a host of associated axonal changes [PC axonal recurrent collateral count, PC thickened axonal profile count, PC axonal branching count], heterotopic PCs, and basket cell rating) in 60 ET cases (11 childhood-onset and 49 adult-onset) and 30 controls. Compared to controls, childhood-onset ET cases had lower PC counts, higher torpedo counts, higher heterotopic PC counts, higher basket cell plexus rating, and marginally higher PC axonal recurrent collateral counts. The median PC thickened axonal profile count and median PC axonal branching count were two to five times higher in childhood-onset ET than controls, but the differences did not reach statistical significance. Childhood-onset and adult-onset ET had similar PC counts, torpedo counts, heterotopic PC counts, basket cell plexus rating, PC axonal recurrent collateral counts, PC thickened axonal profile count and PC axonal branching count. In conclusion, we found that childhood-onset and adult-onset ET shared similar pathological changes in the cerebellum. The data suggest that pathological changes we have observed in the cerebellum in ET are a part of the pathophysiological cascade of events in both forms of the disease and that both groups seem to reach the same pathological endpoints at a similar age of death. Copyright © 2017 Elsevier B.V. All rights reserved.

Point count length and detection of forest neotropical migrant birds

USGS Publications Warehouse

Dawson, D.K.; Smith, D.R.; Robbins, C.S.; Ralph, C. John; Sauer, John R.; Droege, Sam

1995-01-01

Comparisons of bird abundances among years or among habitats assume that the rates at which birds are detected and counted are constant within species. We use point count data collected in forests of the Mid-Atlantic states to estimate detection probabilities for Neotropical migrant bird species as a function of count length. For some species, significant differences existed among years or observers in both the probability of detecting the species and in the rate at which individuals are counted. We demonstrate the consequence that variability in species' detection probabilities can have on estimates of population change, and discuss ways for reducing this source of bias in point count studies.

Probing Jupiter's Radiation Environment with Juno-UVS

NASA Astrophysics Data System (ADS)

Kammer, J.; Gladstone, R.; Greathouse, T. K.; Hue, V.; Versteeg, M. H.; Davis, M. W.; Santos-Costa, D.; Becker, H. N.; Bolton, S. J.; Connerney, J. E. P.; Levin, S.

2017-12-01

While primarily designed to observe photon emission from the Jovian aurora, Juno's Ultraviolet Spectrograph (Juno-UVS) has also measured background count rates associated with penetrating high-energy radiation. These background counts are distinguishable from photon events, as they are generally spread evenly across the entire array of the Juno-UVS detector, and as the spacecraft spins, they set a baseline count rate higher than the sky background rate. During eight perijove passes, this background radiation signature has varied significantly on both short (spin-modulated) timescales, as well as longer timescales ( minutes to hours). We present comparisons of the Juno-UVS data across each of the eight perijove passes, with a focus on the count rate that can be clearly attributed to radiation effects rather than photon events. Once calibrated to determine the relationship between count rate and penetrating high-energy radiation (e.g., using existing GEANT models), these in situ measurements by Juno-UVS will provide additional constraints to radiation belt models close to the planet.

A cascaded model of spectral distortions due to spectral response effects and pulse pileup effects in a photon-counting x-ray detector for CT

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

Cammin, Jochen, E-mail: jcammin1@jhmi.edu, E-mail: ktaguchi@jhmi.edu; Taguchi, Katsuyuki, E-mail: jcammin1@jhmi.edu, E-mail: ktaguchi@jhmi.edu; Xu, Jennifer

Purpose: Energy discriminating, photon-counting detectors (PCDs) are an emerging technology for computed tomography (CT) with various potential benefits for clinical CT. The photon energies measured by PCDs can be distorted due to the interactions of a photon with the detector and the interaction of multiple coincident photons. These effects result in distorted recorded x-ray spectra which may lead to artifacts in reconstructed CT images and inaccuracies in tissue identification. Model-based compensation techniques have the potential to account for the distortion effects. This approach requires only a small number of parameters and is applicable to a wide range of spectra andmore » count rates, but it needs an accurate model of the spectral distortions occurring in PCDs. The purpose of this study was to develop a model of those spectral distortions and to evaluate the model using a PCD (model DXMCT-1; DxRay, Inc., Northridge, CA) and various x-ray spectra in a wide range of count rates. Methods: The authors hypothesize that the complex phenomena of spectral distortions can be modeled by: (1) separating them into count-rate independent factors that we call the spectral response effects (SRE), and count-rate dependent factors that we call the pulse pileup effects (PPE), (2) developing separate models for SRE and PPE, and (3) cascading the SRE and PPE models into a combined SRE+PPE model that describes PCD distortions at both low and high count rates. The SRE model describes the probability distribution of the recorded spectrum, with a photo peak and a continuum tail, given the incident photon energy. Model parameters were obtained from calibration measurements with three radioisotopes and then interpolated linearly for other energies. The PPE model used was developed in the authors’ previous work [K. Taguchi et al., “Modeling the performance of a photon counting x-ray detector for CT: Energy response and pulse pileup effects,” Med. Phys. 38(2), 1089–1102 (2011)]. The agreement between the x-ray spectra calculated by the cascaded SRE+PPE model and the measured spectra was evaluated for various levels of deadtime loss ratios (DLR) and incident spectral shapes, realized using different attenuators, in terms of the weighted coefficient of variation (COV{sub W}), i.e., the root mean square difference weighted by the statistical errors of the data and divided by the mean. Results: At low count rates, when DLR < 10%, the distorted spectra measured by the DXMCT-1 were in agreement with those calculated by SRE only, with COV{sub W}'s less than 4%. At higher count rates, the measured spectra were also in agreement with the ones calculated by the cascaded SRE+PPE model; with PMMA as attenuator, COV{sub W} was 5.6% at a DLR of 22% and as small as 6.7% for a DLR as high as 55%. Conclusions: The x-ray spectra calculated by the proposed model agreed with the measured spectra over a wide range of count rates and spectral shapes. The SRE model predicted the distorted, recorded spectra with low count rates over various types and thicknesses of attenuators. The study also validated the hypothesis that the complex spectral distortions in a PCD can be adequately modeled by cascading the count-rate independent SRE and the count-rate dependent PPE.« less

A cascaded model of spectral distortions due to spectral response effects and pulse pileup effects in a photon-counting x-ray detector for CT

PubMed Central

Cammin, Jochen; Xu, Jennifer; Barber, William C.; Iwanczyk, Jan S.; Hartsough, Neal E.; Taguchi, Katsuyuki

2014-01-01

Purpose: Energy discriminating, photon-counting detectors (PCDs) are an emerging technology for computed tomography (CT) with various potential benefits for clinical CT. The photon energies measured by PCDs can be distorted due to the interactions of a photon with the detector and the interaction of multiple coincident photons. These effects result in distorted recorded x-ray spectra which may lead to artifacts in reconstructed CT images and inaccuracies in tissue identification. Model-based compensation techniques have the potential to account for the distortion effects. This approach requires only a small number of parameters and is applicable to a wide range of spectra and count rates, but it needs an accurate model of the spectral distortions occurring in PCDs. The purpose of this study was to develop a model of those spectral distortions and to evaluate the model using a PCD (model DXMCT-1; DxRay, Inc., Northridge, CA) and various x-ray spectra in a wide range of count rates. Methods: The authors hypothesize that the complex phenomena of spectral distortions can be modeled by: (1) separating them into count-rate independent factors that we call the spectral response effects (SRE), and count-rate dependent factors that we call the pulse pileup effects (PPE), (2) developing separate models for SRE and PPE, and (3) cascading the SRE and PPE models into a combined SRE+PPE model that describes PCD distortions at both low and high count rates. The SRE model describes the probability distribution of the recorded spectrum, with a photo peak and a continuum tail, given the incident photon energy. Model parameters were obtained from calibration measurements with three radioisotopes and then interpolated linearly for other energies. The PPE model used was developed in the authors’ previous work [K. Taguchi , “Modeling the performance of a photon counting x-ray detector for CT: Energy response and pulse pileup effects,” Med. Phys. 38(2), 1089–1102 (2011)]. The agreement between the x-ray spectra calculated by the cascaded SRE+PPE model and the measured spectra was evaluated for various levels of deadtime loss ratios (DLR) and incident spectral shapes, realized using different attenuators, in terms of the weighted coefficient of variation (COVW), i.e., the root mean square difference weighted by the statistical errors of the data and divided by the mean. Results: At low count rates, when DLR < 10%, the distorted spectra measured by the DXMCT-1 were in agreement with those calculated by SRE only, with COVW's less than 4%. At higher count rates, the measured spectra were also in agreement with the ones calculated by the cascaded SRE+PPE model; with PMMA as attenuator, COVW was 5.6% at a DLR of 22% and as small as 6.7% for a DLR as high as 55%. Conclusions: The x-ray spectra calculated by the proposed model agreed with the measured spectra over a wide range of count rates and spectral shapes. The SRE model predicted the distorted, recorded spectra with low count rates over various types and thicknesses of attenuators. The study also validated the hypothesis that the complex spectral distortions in a PCD can be adequately modeled by cascading the count-rate independent SRE and the count-rate dependent PPE. PMID:24694136

Design and implementation of an audio indicator

NASA Astrophysics Data System (ADS)

Zheng, Shiyong; Li, Zhao; Li, Biqing

2017-04-01

This page proposed an audio indicator which designed by using C9014, LED by operational amplifier level indicator, the decimal count/distributor of CD4017. The experimental can control audibly neon and holiday lights through the signal. Input audio signal after C9014 composed of operational amplifier for power amplifier, the adjust potentiometer extraction amplification signal input voltage CD4017 distributors make its drive to count, then connect the LED display running situation of the circuit. This simple audio indicator just use only U1 and can produce two colors LED with the audio signal tandem come pursuit of the running effect, from LED display the running of the situation takes can understand the general audio signal. The variation in the audio and the frequency of the signal and the corresponding level size. In this light can achieve jump to change, slowly, atlas, lighting four forms, used in home, hotel, discos, theater, advertising and other fields, and a wide range of USES, rU1h life in a modern society.

Shared performance monitor in a multiprocessor system

DOEpatents

Chiu, George; Gara, Alan G.; Salapura, Valentina

2012-07-24

A performance monitoring unit (PMU) and method for monitoring performance of events occurring in a multiprocessor system. The multiprocessor system comprises a plurality of processor devices units, each processor device for generating signals representing occurrences of events in the processor device, and, a single shared counter resource for performance monitoring. The performance monitor unit is shared by all processor cores in the multiprocessor system. The PMU comprises: a plurality of performance counters each for counting signals representing occurrences of events from one or more the plurality of processor units in the multiprocessor system; and, a plurality of input devices for receiving the event signals from one or more processor devices of the plurality of processor units, the plurality of input devices programmable to select event signals for receipt by one or more of the plurality of performance counters for counting, wherein the PMU is shared between multiple processing units, or within a group of processors in the multiprocessing system. The PMU is further programmed to monitor event signals issued from non-processor devices.

Channel-capacity gain in entanglement-assisted communication protocols based exclusively on linear optics, single-photon inputs, and coincidence photon counting

DOE PAGES

Lougovski, P.; Uskov, D. B.

2015-08-04

Entanglement can effectively increase communication channel capacity as evidenced by dense coding that predicts a capacity gain of 1 bit when compared to entanglement-free protocols. However, dense coding relies on Bell states and when implemented using photons the capacity gain is bounded by 0.585 bits due to one's inability to discriminate between the four optically encoded Bell states. In this research we study the following question: Are there alternative entanglement-assisted protocols that rely only on linear optics, coincidence photon counting, and separable single-photon input states and at the same time provide a greater capacity gain than 0.585 bits? In thismore » study, we show that besides the Bell states there is a class of bipartite four-mode two-photon entangled states that facilitate an increase in channel capacity. We also discuss how the proposed scheme can be generalized to the case of two-photon N-mode entangled states for N=6,8.« less

Analysis of Sample Size, Counting Time, and Plot Size from an Avian Point Count Survey on Hoosier National Forest, Indiana

Treesearch

Frank R. Thompson; Monica J. Schwalbach

1995-01-01

We report results of a point count survey of breeding birds on Hoosier National Forest in Indiana. We determined sample size requirements to detect differences in means and the effects of count duration and plot size on individual detection rates. Sample size requirements ranged from 100 to >1000 points with Type I and II error rates of <0.1 and 0.2. Sample...

A New Statistics-Based Online Baseline Restorer for a High Count-Rate Fully Digital System.

PubMed

Li, Hongdi; Wang, Chao; Baghaei, Hossain; Zhang, Yuxuan; Ramirez, Rocio; Liu, Shitao; An, Shaohui; Wong, Wai-Hoi

2010-04-01

The goal of this work is to develop a novel, accurate, real-time digital baseline restorer using online statistical processing for a high count-rate digital system such as positron emission tomography (PET). In high count-rate nuclear instrumentation applications, analog signals are DC-coupled for better performance. However, the detectors, pre-amplifiers and other front-end electronics would cause a signal baseline drift in a DC-coupling system, which will degrade the performance of energy resolution and positioning accuracy. Event pileups normally exist in a high-count rate system and the baseline drift will create errors in the event pileup-correction. Hence, a baseline restorer (BLR) is required in a high count-rate system to remove the DC drift ahead of the pileup correction. Many methods have been reported for BLR from classic analog methods to digital filter solutions. However a single channel BLR with analog method can only work under 500 kcps count-rate, and normally an analog front-end application-specific integrated circuits (ASIC) is required for the application involved hundreds BLR such as a PET camera. We have developed a simple statistics-based online baseline restorer (SOBLR) for a high count-rate fully digital system. In this method, we acquire additional samples, excluding the real gamma pulses, from the existing free-running ADC in the digital system, and perform online statistical processing to generate a baseline value. This baseline value will be subtracted from the digitized waveform to retrieve its original pulse with zero-baseline drift. This method can self-track the baseline without a micro-controller involved. The circuit consists of two digital counter/timers, one comparator, one register and one subtraction unit. Simulation shows a single channel works at 30 Mcps count-rate with pileup condition. 336 baseline restorer circuits have been implemented into 12 field-programmable-gate-arrays (FPGA) for our new fully digital PET system.

Death rates in HIV-positive antiretroviral-naive patients with CD4 count greater than 350 cells per microL in Europe and North America: a pooled cohort observational study

PubMed Central

2011-01-01

Background It is unclear whether antiretroviral (ART) naive HIV-positive individuals with high CD4 counts have a raised mortality risk compared with the general population, but this is relevant for considering earlier initiation of antiretroviral therapy. Methods Pooling data from 23 European and North American cohorts, we calculated country-, age-, sex-, and year-standardised mortality ratios (SMRs), stratifying by risk group. Included patients had at least one pre-ART CD4 count above 350 cells/mm3. The association between CD4 count and death rate was evaluated using Poisson regression methods. Findings Of 40,830 patients contributing 80,682 person-years of follow up with CD4 count above 350 cells/mm3, 419 (1.0%) died. The SMRs (95% confidence interval) were 1.30 (1.06-1.58) in homosexual men, and 2.94 (2.28-3.73) and 9.37 (8.13-10.75) in the heterosexual and IDU risk groups respectively. CD4 count above 500 cells/mm3 was associated with a lower death rate than 350-499 cells/mm3: adjusted rate ratios (95% confidence intervals) for 500-699 cells/mm3 and above 700 cells/mm3 were 0.77 (0.61-0.95) and 0.66 (0.52-0.85) respectively. Interpretation In HIV-infected ART-naive patients with high CD4 counts, death rates were raised compared with the general population. In homosexual men this was modest, suggesting that a proportion of the increased risk in other groups is due to confounding by other factors. Even in this high CD4 count range, lower CD4 count was associated with raised mortality. PMID:20638118

Precision absolute-value amplifier for a precision voltmeter

DOEpatents

Hearn, W.E.; Rondeau, D.J.

1982-10-19

Bipolar inputs are afforded by the plus inputs of first and second differential input amplifiers. A first gain determining resistor is connected between the minus inputs of the differential amplifiers. First and second diodes are connected between the respective minus inputs and the respective outputs of the differential amplifiers. First and second FETs have their gates connected to the outputs of the amplifiers, while their respective source and drain circuits are connected between the respective minus inputs and an output lead extending to a load resistor. The output current through the load resistor is proportional to the absolute value of the input voltage difference between the bipolar input terminals. A third differential amplifier has its plus input terminal connected to the load resistor. A second gain determining resistor is connected between the minus input of the third differential amplifier and a voltage source. A third FET has its gate connected to the output of the third amplifier. The source and drain circuit of the third transistor is connected between the minus input of the third amplifier and a voltage-frequency converter, constituting an output device. A polarity detector is also provided, comprising a pair of transistors having their inputs connected to the outputs of the first and second differential amplifiers. The outputs of the polarity detector are connected to gates which switch the output of the voltage-frequency converter between up and down counting outputs.

Precision absolute value amplifier for a precision voltmeter

DOEpatents

Hearn, William E.; Rondeau, Donald J.

1985-01-01

Bipolar inputs are afforded by the plus inputs of first and second differential input amplifiers. A first gain determining resister is connected between the minus inputs of the differential amplifiers. First and second diodes are connected between the respective minus inputs and the respective outputs of the differential amplifiers. First and second FETs have their gates connected to the outputs of the amplifiers, while their respective source and drain circuits are connected between the respective minus inputs and an output lead extending to a load resister. The output current through the load resister is proportional to the absolute value of the input voltage difference between the bipolar input terminals. A third differential amplifier has its plus input terminal connected to the load resister. A second gain determining resister is connected between the minus input of the third differential amplifier and a voltage source. A third FET has its gate connected to the output of the third amplifier. The source and drain circuit of the third transistor is connected between the minus input of the third amplifier and a voltage-frequency converter, constituting an output device. A polarity detector is also provided, comprising a pair of transistors having their inputs connected to the outputs of the first and second differential amplifiers. The outputs of the polarity detector are connected to gates which switch the output of the voltage-frequency converter between up and down counting outputs.

Ultra-Compact Motor Controller

NASA Technical Reports Server (NTRS)

Townsend, William T.; Cromwell, Adam; Hauptman, Traveler; Pratt, Gill Andrews

2012-01-01

This invention is an electronically commutated brushless motor contro ller that incorporates Hall-array sensing in a small, 42-gram packag e that provides 4096 absolute counts per motor revolution position s ensing. The unit is the size of a miniature hockey puck, and is a 44 -pin male connector that provides many I/O channels, including CANbus , RS-232 communications, general-purpose analog and digital I/O (GPI O), analog and digital Hall inputs, DC power input (18-90 VDC, 0-l0 A), three-phase motor outputs, and a strain gauge amplifier.

A Prescription for List-Mode Data Processing Conventions

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

Beddingfield, David H.; Swinhoe, Martyn Thomas; Huszti, Jozsef

There are a variety of algorithmic approaches available to process list-mode pulse streams to produce multiplicity histograms for subsequent analysis. In the development of the INCC v6.0 code to include the processing of this data format, we have noted inconsistencies in the “processed time” between the various approaches. The processed time, tp, is the time interval over which the recorded pulses are analyzed to construct multiplicity histograms. This is the time interval that is used to convert measured counts into count rates. The observed inconsistencies in tp impact the reported count rate information and the determination of the error-values associatedmore » with the derived singles, doubles, and triples counting rates. This issue is particularly important in low count-rate environments. In this report we will present a prescription for the processing of list-mode counting data that produces values that are both correct and consistent with traditional shift-register technologies. It is our objective to define conventions for list mode data processing to ensure that the results are physically valid and numerically aligned with the results from shift-register electronics.« less

40 CFR 75.83 - Calculation of Hg mass emissions and heat input rate.

Code of Federal Regulations, 2010 CFR

2010-07-01

... heat input rate. 75.83 Section 75.83 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY... Calculation of Hg mass emissions and heat input rate. The owner or operator shall calculate Hg mass emissions and heat input rate in accordance with the procedures in sections 9.1 through 9.3 of appendix F to...

Comparison of C-14 liquid scintillation counting at NIST and NRC Canada

PubMed Central

Bergeron, Denis E.; Galea, Raphael; Laureano-Pérez, Lizbeth; Zimmerman, Brian E.

2016-01-01

An informal bilateral comparison of 14C liquid scintillation (LS) counting at the National Research Council of Canada (NRC) and the National Institute of Standards and Technology (NIST) has been completed. Two solutions, one containing 14C-labeled sodium benzoate and one containing 14C-labeled n-hexadecane, were measured at both laboratories. Despite observed LS cocktail instabilities, the two laboratories achieved accord in their standardizations of both solutions. At the conclusion of the comparison, the beta spectrum used for efficiency calculations was identified as inadequate and the data were reanalyzed with different inputs, improving accord. PMID:26585641

THE USE OF QUENCHING IN A LIQUID SCINTILLATION COUNTER FOR QUANTITATIVE ANALYSIS

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

Foster, G.V.

1963-01-01

Quenching was used to quantitatively determine the amonnt of quenching agent present. A sealed promethium147 source was prepared to be used for the count rate determinations. Two methods to determine the amount of quenching agent present in a sample were developed. One method related the count rate of a sample containing a quenching agent to the amount of quenching agent present. Calibration curves were plotted using both color and chemical quenchers. The quenching agents used were: F.D.C. Orange No. 2, F.D.C. Yellow No. 3, F.D.C. Yellow No. 4, Scarlet Red, acetone, benzaldehyde, and carbon tetrachloride. the color quenchers gave amore » linear-relationship, while the chemical quenchers gave a non-linear relationship. Quantities of the color quenchers between about 0.008 mg and 0.100 mg can be determined with an error less than 5%. The calibration curves were found to be usable over a long period of time. The other method related the change in the ratio of the count rates in two voltage windows to the amount of quenching agent present. The quenchers mentioned above were used. Calibration curves were plotted for both the color and chemical quenchers. The relationships of ratio versus amount of quencher were non-linear in each case. It was shown that the reproducibility of the count rate and the ratio was independent of the amount of quencher present but was dependent on the count rate. At count rates above 10,000 counts per minute the reproducibility was better than 1%. (TCO)« less

Performance Prediction Toolkit

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

Chennupati, Gopinath; Santhi, Nanadakishore; Eidenbenz, Stephen

The Performance Prediction Toolkit (PPT), is a scalable co-design tool that contains the hardware and middle-ware models, which accept proxy applications as input in runtime prediction. PPT relies on Simian, a parallel discrete event simulation engine in Python or Lua, that uses the process concept, where each computing unit (host, node, core) is a Simian entity. Processes perform their task through message exchanges to remain active, sleep, wake-up, begin and end. The PPT hardware model of a compute core (such as a Haswell core) consists of a set of parameters, such as clock speed, memory hierarchy levels, their respective sizes,more » cache-lines, access times for different cache levels, average cycle counts of ALU operations, etc. These parameters are ideally read off a spec sheet or are learned using regression models learned from hardware counters (PAPI) data. The compute core model offers an API to the software model, a function called time_compute(), which takes as input a tasklist. A tasklist is an unordered set of ALU, and other CPU-type operations (in particular virtual memory loads and stores). The PPT application model mimics the loop structure of the application and replaces the computational kernels with a call to the hardware model's time_compute() function giving tasklists as input that model the compute kernel. A PPT application model thus consists of tasklists representing kernels and the high-er level loop structure that we like to think of as pseudo code. The key challenge for the hardware model's time_compute-function is to translate virtual memory accesses into actual cache hierarchy level hits and misses.PPT also contains another CPU core level hardware model, Analytical Memory Model (AMM). The AMM solves this challenge soundly, where our previous alternatives explicitly include the L1,L2,L3 hit-rates as inputs to the tasklists. Explicit hit-rates inevitably only reflect the application modeler's best guess, perhaps informed by a few small test problems using hardware counters; also, hard-coded hit-rates make the hardware model insensitive to changes in cache sizes. Alternatively, we use reuse distance distributions in the tasklists. In general, reuse profiles require the application modeler to run a very expensive trace analysis on the real code that realistically can be done at best for small examples.« less

Performance evaluation of the Ingenuity TF PET/CT scanner with a focus on high count-rate conditions

NASA Astrophysics Data System (ADS)

Kolthammer, Jeffrey A.; Su, Kuan-Hao; Grover, Anu; Narayanan, Manoj; Jordan, David W.; Muzic, Raymond F.

2014-07-01

This study evaluated the positron emission tomography (PET) imaging performance of the Ingenuity TF 128 PET/computed tomography (CT) scanner which has a PET component that was designed to support a wider radioactivity range than is possible with those of Gemini TF PET/CT and Ingenuity TF PET/MR. Spatial resolution, sensitivity, count rate characteristics and image quality were evaluated according to the NEMA NU 2-2007 standard and ACR phantom accreditation procedures; these were supplemented by additional measurements intended to characterize the system under conditions that would be encountered during quantitative cardiac imaging with 82Rb. Image quality was evaluated using a hot spheres phantom, and various contrast recovery and noise measurements were made from replicated images. Timing and energy resolution, dead time, and the linearity of the image activity concentration, were all measured over a wide range of count rates. Spatial resolution (4.8-5.1 mm FWHM), sensitivity (7.3 cps kBq-1), peak noise-equivalent count rate (124 kcps), and peak trues rate (365 kcps) were similar to those of the Gemini TF PET/CT. Contrast recovery was higher with a 2 mm, body-detail reconstruction than with a 4 mm, body reconstruction, although the precision was reduced. The noise equivalent count rate peak was broad (within 10% of peak from 241-609 MBq). The activity measured in phantom images was within 10% of the true activity for count rates up to those observed in 82Rb cardiac PET studies.

Current automated 3D cell detection methods are not a suitable replacement for manual stereologic cell counting

PubMed Central

Schmitz, Christoph; Eastwood, Brian S.; Tappan, Susan J.; Glaser, Jack R.; Peterson, Daniel A.; Hof, Patrick R.

2014-01-01

Stereologic cell counting has had a major impact on the field of neuroscience. A major bottleneck in stereologic cell counting is that the user must manually decide whether or not each cell is counted according to three-dimensional (3D) stereologic counting rules by visual inspection within hundreds of microscopic fields-of-view per investigated brain or brain region. Reliance on visual inspection forces stereologic cell counting to be very labor-intensive and time-consuming, and is the main reason why biased, non-stereologic two-dimensional (2D) “cell counting” approaches have remained in widespread use. We present an evaluation of the performance of modern automated cell detection and segmentation algorithms as a potential alternative to the manual approach in stereologic cell counting. The image data used in this study were 3D microscopic images of thick brain tissue sections prepared with a variety of commonly used nuclear and cytoplasmic stains. The evaluation compared the numbers and locations of cells identified unambiguously and counted exhaustively by an expert observer with those found by three automated 3D cell detection algorithms: nuclei segmentation from the FARSIGHT toolkit, nuclei segmentation by 3D multiple level set methods, and the 3D object counter plug-in for ImageJ. Of these methods, FARSIGHT performed best, with true-positive detection rates between 38 and 99% and false-positive rates from 3.6 to 82%. The results demonstrate that the current automated methods suffer from lower detection rates and higher false-positive rates than are acceptable for obtaining valid estimates of cell numbers. Thus, at present, stereologic cell counting with manual decision for object inclusion according to unbiased stereologic counting rules remains the only adequate method for unbiased cell quantification in histologic tissue sections. PMID:24847213

Background Conditions for the October 29, 2003 Solar Flare by the AVS-F Apparatus Data

NASA Astrophysics Data System (ADS)

Arkhangelskaja, I. V.; Arkhangelskiy, A. I.; Lyapin, A. R.; Troitskaya, E. V.

The background model for AVS-F apparatus onboard CORONAS-F satellite for the October 29, 2003 X10-class solar flare is discussed in the presented work. This background model developed for AVS-F counts rate in the low- and high-energy spectral ranges in both individual channels and summarized. Count rate were approximated by polynomials of high order taking into account the mean count rate in the geomagnetic equatorial region at the different orbits parts and Kp-index averaged on 5 bins in time interval from -24 to -12 hours before the time of geomagnetic equator passing. The observed averaged counts rate on equator in the region of geomagnetic latitude ±5o and estimated minimum count rate values are in coincidence within statistical errors for all selected orbits parts used for background modeling. This model will used to refine the estimated energy of registered during the solar flare spectral features and detailed analysis of their temporal profiles behavior both in corresponding energy bands and in summarized energy range.

Extreme Ultraviolet Explorer observations of the magnetic cataclysmic variable RE 1938-461

NASA Technical Reports Server (NTRS)

Warren, John K.; Vallerga, John V.; Mauche, Christopher W.; Mukai, Koji; Siegmund, Oswald H. W.

1993-01-01

The magnetic cataclysmic variable RE 1938-461 was observed by the Extreme Ultraviolet Explorer (EUVE) Deep Survey instrument on 1992 July 8-9 during in-orbit calibration. It was detected in the Lexan/ boron (65-190 A) band, with a quiescent count rate of 0.0062 +/- 0.0017/s, and was not detected in the aluminum/carbon (160-360 A) band. The Lexan/boron count rate is lower than the corresponding ROSAT wide-field camera Lexan/boron count rate. This is consistent with the fact that the source was in a low state during an optical observation performed just after the EUVE observation, whereas it was in an optical high state during the ROSAT observation. The quiescent count rates are consistent with a virtual cessation of accretion. Two transient events lasting about 1 hr occurred during the Lexan/boron pointing, the second at a count rate of 0.050 +/- 0.006/s. This appears to be the first detection of an EUV transient during the low state of a magnetic cataclysmic variable. We propose two possible explanations for the transient events.

Conversion from Engineering Units to Telemetry Counts on Dryden Flight Simulators

NASA Technical Reports Server (NTRS)

Fantini, Jay A.

1998-01-01

Dryden real-time flight simulators encompass the simulation of pulse code modulation (PCM) telemetry signals. This paper presents a new method whereby the calibration polynomial (from first to sixth order), representing the conversion from counts to engineering units (EU), is numerically inverted in real time. The result is less than one-count error for valid EU inputs. The Newton-Raphson method is used to numerically invert the polynomial. A reverse linear interpolation between the EU limits is used to obtain an initial value for the desired telemetry count. The method presented here is not new. What is new is how classical numerical techniques are optimized to take advantage of modem computer power to perform the desired calculations in real time. This technique makes the method simple to understand and implement. There are no interpolation tables to store in memory as in traditional methods. The NASA F-15 simulation converts and transmits over 1000 parameters at 80 times/sec. This paper presents algorithm development, FORTRAN code, and performance results.

Making Schools Work

ERIC Educational Resources Information Center

Bruns, Barbara; Filmer, Deon; Patrinos, Harry Anthony

2011-01-01

This book is about the threats to education quality in the developing world that cannot be explained by lack of resources. It reviews the observed phenomenon of service delivery failures in public education: cases where programs and policies increase the inputs to education but do not produce effective services where it counts--in schools and…

Active quench and reset integrated circuit with novel hold-off time control logic for Geiger-mode avalanche photodiodes.

PubMed

Deng, Shijie; Morrison, Alan P

2012-09-15

This Letter presents an active quench-and-reset circuit for Geiger-mode avalanche photodiodes (GM-APDs). The integrated circuit was fabricated using a conventional 0.35 μm complementary metal oxide semiconductor process. Experimental results show that the circuit is capable of linearly setting the hold-off time from several nanoseconds to microseconds with a resolution of 6.5 ns. This allows the selection of the optimal afterpulse-free hold-off time for the GM-APD via external digital inputs or additional signal processing circuitry. Moreover, this circuit resets the APD automatically following the end of the hold-off period, thus simplifying the control for the end user. Results also show that a minimum dead time of 28.4 ns is achieved, demonstrating a saturated photon-counting rate of 35.2 Mcounts/s.

Crater Age and Hydrogen Content in Lunar Regolith from LEND Neutron Data

NASA Astrophysics Data System (ADS)

Sanin, Anton; Starr, Richard; Litvak, Maxim; Petro, Noah; Mitrofanov, Igor

2017-04-01

We are presenting an analysis of Lunar Exploration Neutron Detector (LEND) epithermal neutron count rates for a large set of mid-latitude craters. Epithermal neutron count rates for crater interiors measured by the LEND Sensor for Epithermal Neutrons (SETN) were compared to crater exteriors for 322 craters. An increase in relative count rate at about 9-sigma confidence level was found, consistent with a lower hydrogen content. A smaller subset of 31 craters, all located near three Copernican era craters, Jackson, Tycho, and Necho, also shows a significant increase in Optical Maturity parameter implying an immature regolith. The increase in SETN count rate for these craters is greater than the increase for the full set of craters by more than a factor of two.

Crater Age and Hydrogen Content in Lunar Regolith from LEND Neutron Data

NASA Technical Reports Server (NTRS)

Starr, Richard D.; Litvak, Maxim L.; Petro, Noah E.; Mitrofanov, Igor G.; Boynton, William V.; Chin, Gordon; Livengood, Timothy A.; McClanahan, Timothy P.; Sanin, Anton B.; Sagdeev, Roald Z.;

Relationship of milking rate to somatic cell count.

PubMed

Brown, C A; Rischette, S J; Schultz, L H

1986-03-01

Information on milking rate, monthly bucket somatic cell counts, mastitis treatment, and milk production was obtained from 284 lactations of Holstein cows separated into three lactation groups. Significant correlations between somatic cell count (linear score) and other parameters included production in lactation 1 (-.185), production in lactation 2 (-.267), and percent 2-min milk in lactation 2 (.251). Somatic cell count tended to increase with maximum milking rate in all lactations, but correlations were not statistically significant. Twenty-nine percent of cows with milking rate measurements were treated for clinical mastitis. Treated cows in each lactation group produced less milk than untreated cows. In the second and third lactation groups, treated cows had a shorter total milking time and a higher percent 2-min milk than untreated cows, but differences were not statistically significant. Overall, the data support the concept that faster milking cows tend to have higher cell counts and more mastitis treatments, particularly beyond first lactation. However, the magnitude of the relationship was small.

Event-related potentials reveal the relations between feature representations at different levels of abstraction.

PubMed

Hannah, Samuel D; Shedden, Judith M; Brooks, Lee R; Grundy, John G

2016-11-01

In this paper, we use behavioural methods and event-related potentials (ERPs) to explore the relations between informational and instantiated features, as well as the relation between feature abstraction and rule type. Participants are trained to categorize two species of fictitious animals and then identify perceptually novel exemplars. Critically, two groups are given a perfectly predictive counting rule that, according to Hannah and Brooks (2009. Featuring familiarity: How a familiar feature instantiation influences categorization. Canadian Journal of Experimental Psychology/Revue Canadienne de Psychologie Expérimentale, 63, 263-275. Retrieved from http://doi.org/10.1037/a0017919), should orient them to using abstract informational features when categorizing the novel transfer items. A third group is taught a feature list rule, which should orient them to using detailed instantiated features. One counting-rule group were taught their rule before any exposure to the actual stimuli, and the other immediately after training, having learned the instantiations first. The feature-list group were also taught their rule after training. The ERP results suggest that at test, the two counting-rule groups processed items differently, despite their identical rule. This not only supports the distinction that informational and instantiated features are qualitatively different feature representations, but also implies that rules can readily operate over concrete inputs, in contradiction to traditional approaches that assume that rules necessarily act on abstract inputs.

40 CFR 75.36 - Missing data procedures for heat input rate determinations.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 16 2011-07-01 2011-07-01 false Missing data procedures for heat input... (CONTINUED) AIR PROGRAMS (CONTINUED) CONTINUOUS EMISSION MONITORING Missing Data Substitution Procedures § 75.36 Missing data procedures for heat input rate determinations. (a) When hourly heat input rate is...

40 CFR 75.36 - Missing data procedures for heat input rate determinations.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 17 2014-07-01 2014-07-01 false Missing data procedures for heat input... (CONTINUED) AIR PROGRAMS (CONTINUED) CONTINUOUS EMISSION MONITORING Missing Data Substitution Procedures § 75.36 Missing data procedures for heat input rate determinations. (a) When hourly heat input rate is...

40 CFR 75.36 - Missing data procedures for heat input rate determinations.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 17 2013-07-01 2013-07-01 false Missing data procedures for heat input... (CONTINUED) AIR PROGRAMS (CONTINUED) CONTINUOUS EMISSION MONITORING Missing Data Substitution Procedures § 75.36 Missing data procedures for heat input rate determinations. (a) When hourly heat input rate is...

40 CFR 75.36 - Missing data procedures for heat input rate determinations.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 16 2010-07-01 2010-07-01 false Missing data procedures for heat input... (CONTINUED) AIR PROGRAMS (CONTINUED) CONTINUOUS EMISSION MONITORING Missing Data Substitution Procedures § 75.36 Missing data procedures for heat input rate determinations. (a) When hourly heat input rate is...

40 CFR 75.36 - Missing data procedures for heat input rate determinations.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 17 2012-07-01 2012-07-01 false Missing data procedures for heat input... (CONTINUED) AIR PROGRAMS (CONTINUED) CONTINUOUS EMISSION MONITORING Missing Data Substitution Procedures § 75.36 Missing data procedures for heat input rate determinations. (a) When hourly heat input rate is...

The intersection of health and wealth: association between personal bankruptcy and myocardial infarction rates in Canada.

PubMed

Savu, Anamaria; Schopflocher, Donald; Scholnick, Barry; Kaul, Padma

2016-01-13

We examined the association between personal bankruptcy filing and acute myocardial infarction (AMI) rates in Canada. Between 2002 and 2009, aggregate and yearly bankruptcy and AMI rates were estimated for 1,155 forward sortation areas of Canada. Scatter plot and correlations were used to assess the association of the aggregate rates. Cross-lagged structural equation models were used to explore the longitudinal relationship between bankruptcy and AMI after adjustment for socio-economic factors. A cross-lagged structural equation model estimated that on average, an increase of 100 in bankruptcy filing count is associated with an increase of 1.5 (p = 0.02) in AMI count in the following year, and an increase of 100 in AMI count is associated with an increase of 7 (p < 0.01) in bankruptcy filing count. We found that regions with higher rates of AMI corresponded to those with higher levels of economic and financial stress, as indicated by personal bankruptcy rate, and vice-versa.

Direct recovery of regional tracer kinetics from temporally inconsistent dynamic ECT projections using dimension-reduced time-activity basis

NASA Astrophysics Data System (ADS)

Maltz, Jonathan S.

2000-11-01

We present an algorithm of reduced computational cost which is able to estimate kinetic model parameters directly from dynamic ECT sinograms made up of temporally inconsistent projections. The algorithm exploits the extreme degree of parameter redundancy inherent in linear combinations of the exponential functions which represent the modes of first-order compartmental systems. The singular value decomposition is employed to find a small set of orthogonal functions, the linear combinations of which are able to accurately represent all modes within the physiologically anticipated range in a given study. The reduced-dimension basis is formed as the convolution of this orthogonal set with a measured input function. The Moore-Penrose pseudoinverse is used to find coefficients of this basis. Algorithm performance is evaluated at realistic count rates using MCAT phantom and clinical 99mTc-teboroxime myocardial study data. Phantom data are modelled as originating from a Poisson process. For estimates recovered from a single slice projection set containing 2.5×105 total counts, recovered tissue responses compare favourably with those obtained using more computationally intensive methods. The corresponding kinetic parameter estimates (coefficients of the new basis) exhibit negligible bias, while parameter variances are low, falling within 30% of the Cramér-Rao lower bound.

Rheumatoid arthritis disease activity measures: American College of Rheumatology recommendations for use in clinical practice.

PubMed

Anderson, Jaclyn; Caplan, Liron; Yazdany, Jinoos; Robbins, Mark L; Neogi, Tuhina; Michaud, Kaleb; Saag, Kenneth G; O'Dell, James R; Kazi, Salahuddin

2012-05-01

Although the systematic measurement of disease activity facilitates clinical decision making in rheumatoid arthritis (RA), no recommendations currently exist on which measures should be applied in clinical practice in the US. The American College of Rheumatology (ACR) convened a Working Group (WG) to comprehensively evaluate the validity, feasibility, and acceptability of available RA disease activity measures and derive recommendations for their use in clinical practice. The Rheumatoid Arthritis Clinical Disease Activity Measures Working Group conducted a systematic review of the literature to identify RA disease activity measures. Using exclusion criteria, input from an Expert Advisory Panel (EAP), and psychometric analysis, a list of potential measures was created. A survey was administered to rheumatologists soliciting input. The WG used these survey results in conjunction with the psychometric analyses to derive final recommendations. Systematic review of the literature resulted in identification of 63 RA disease activity measures. Application of exclusion criteria and ratings by the EAP narrowed the list to 14 measures for further evaluation. Practicing rheumatologists rated 9 of these 14 measures as most useful and feasible. From these 9 measures, the WG selected 6 with the best psychometric properties for inclusion in the final set of ACR-recommended RA disease activity measures. We recommend the Clinical Disease Activity Index, Disease Activity Score with 28-joint counts (erythrocyte sedimentation rate or C-reactive protein), Patient Activity Scale (PAS), PAS-II, Routine Assessment of Patient Index Data with 3 measures, and Simplified Disease Activity Index because they are accurate reflections of disease activity; are sensitive to change; discriminate well between low, moderate, and high disease activity states; have remission criteria; and are feasible to perform in clinical settings. Copyright © 2012 by the American College of Rheumatology.

Relationship of long-term highly active antiretroviral therapy on salivary flow rate and CD4 Count among HIV-infected patients.

PubMed

Kumar, J Vijay; Baghirath, P Venkat; Naishadham, P Parameswar; Suneetha, Sujai; Suneetha, Lavanya; Sreedevi, P

2015-01-01

To determine if long-term highly active antiretroviral therapy (HAART) therapy alters salivary flow rate and also to compare its relation of CD4 count with unstimulated and stimulated whole saliva. A cross-sectional study was performed on 150 individuals divided into three groups. Group I (50 human immunodeficiency virus (HIV) seropositive patients, but not on HAART therapy), Group II (50 HIV-infected subjects and on HAART for less than 3 years called short-term HAART), Group III (50 HIV-infected subjects and on HAART for more than or equal to 3 years called long-term HAART). Spitting method proposed by Navazesh and Kumar was used for the measurement of unstimulated and stimulated salivary flow rate. Chi-square test and analysis of variance (ANOVA) were used for statistical analysis. The mean CD4 count was 424.78 ± 187.03, 497.82 ± 206.11 and 537.6 ± 264.00 in the respective groups. Majority of the patients in all the groups had a CD4 count between 401 and 600. Both unstimulated and stimulated whole salivary (UWS and SWS) flow rates in Group I was found to be significantly higher than in Group II (P < 0.05). Unstimulated salivary flow rate between Group II and III subjects were also found to be statistically significant (P < 0.05). ANOVA performed between CD4 count and unstimulated and stimulated whole saliva in each group demonstrated a statistically significant relationship in Group II (P < 0.05). There were no significant results found between CD4 count and stimulated whole saliva in each groups. The reduction in CD4 cell counts were significantly associated with salivary flow rates of HIV-infected individuals who are on long-term HAART.

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

Evaluation of Hematological Parameters in the Differentiation of Subarachnoid Hemorrhage and Other Headache Syndromes.

PubMed

Goktekin, Mehmet C; Yilmaz, Mustafa

2018-06-01

In this research, the aim was to compare hematological data for the differentiation of subarachnoid hemorrhage, migraine attack, and other headache syndromes during consultation in emergency service. In this research, which was designed as retrospective case control study, hematological parameters (WBC, HgB, HCT, PLT, lymphocyte and neutrophile counts and neutrophile/lymphocyte rates) of the patients consulting to emergency service with SAH and migraine and other consulting patients complaining mainly from headache and having normal cranial CT were analysed. Sixty migraine attack patients (F/M:47/13), 57 SAH patients (F/M:30/27), and 53 patients except migraine having normal brain CT (F/M:36/17) who were consulted to emergency service with headache complaint were included in our research. WBC, Hct, HgB, MCV, PLT, MPV, LY, Neu counts, and NY/LY rates were found to differentiate between SAH and migraine. WBC, PLT, MPV, LY, and Neu rates were found to differentiate between SAH and HS patients. Only Hct, HgB, MCV, and NY/LY rates were found to differ meaningfully between SAH and migraine patients but these rates were not found to have meaningful difference between SAH and HS patients. In addition, an increase in WBC counts and NY/LY rates and decrease in MPV counts in ROC analysis were found to be more specific for SAH. WBC, HgB, HCT, PLT, lymphocyte and Neu counts, and NY/LY rates can indicate distinguishing SAH and migraine. WBC, HgB, HCT, PLT, lymphocyte and Neu counts can indicate to the clinician a differentiation of SAH and other headache syndromes.

Multianode cylindrical proportional counter for high count rates

DOEpatents

Hanson, J.A.; Kopp, M.K.

1980-05-23

A cylindrical, multiple-anode proportional counter is provided for counting of low-energy photons (< 60 keV) at count rates of greater than 10/sup 5/ counts/sec. A gas-filled proportional counter cylinder forming an outer cathode is provided with a central coaxially disposed inner cathode and a plurality of anode wires disposed in a cylindrical array in coaxial alignment with and between the inner and outer cathodes to form a virtual cylindrical anode coaxial with the inner and outer cathodes. The virtual cylindrical anode configuration improves the electron drift velocity by providing a more uniform field strength throughout the counter gas volume, thus decreasing the electron collection time following the detection of an ionizing event. This avoids pulse pile-up and coincidence losses at these high count rates. Conventional RC position encoding detection circuitry may be employed to extract the spatial information from the counter anodes.

Multianode cylindrical proportional counter for high count rates

DOEpatents

Hanson, James A.; Kopp, Manfred K.

1981-01-01

A cylindrical, multiple-anode proportional counter is provided for counting of low-energy photons (<60 keV) at count rates of greater than 10.sup.5 counts/sec. A gas-filled proportional counter cylinder forming an outer cathode is provided with a central coaxially disposed inner cathode and a plurality of anode wires disposed in a cylindrical array in coaxial alignment with and between the inner and outer cathodes to form a virtual cylindrical anode coaxial with the inner and outer cathodes. The virtual cylindrical anode configuration improves the electron drift velocity by providing a more uniform field strength throughout the counter gas volume, thus decreasing the electron collection time following the detection of an ionizing event. This avoids pulse pile-up and coincidence losses at these high count rates. Conventional RC position encoding detection circuitry may be employed to extract the spatial information from the counter anodes.

Solid-state Image Sensor with Focal-plane Digital Photon-counting Pixel Array

NASA Technical Reports Server (NTRS)

Fossum, Eric R.; Pain, Bedabrata

1997-01-01

A solid-state focal-plane imaging system comprises an NxN array of high gain. low-noise unit cells. each unit cell being connected to a different one of photovoltaic detector diodes, one for each unit cell, interspersed in the array for ultra low level image detection and a plurality of digital counters coupled to the outputs of the unit cell by a multiplexer(either a separate counter for each unit cell or a row of N of counters time shared with N rows of digital counters). Each unit cell includes two self-biasing cascode amplifiers in cascade for a high charge-to-voltage conversion gain (greater than 1mV/e(-)) and an electronic switch to reset input capacitance to a reference potential in order to be able to discriminate detection of an incident photon by the photoelectron (e(-))generated in the detector diode at the input of the first cascode amplifier in order to count incident photons individually in a digital counter connected to the output of the second cascade amplifier. Reseting the input capacitance and initiating self-biasing of the amplifiers occurs every clock cycle of an integratng period to enable ultralow light level image detection by the may of photovoltaic detector diodes under such ultralow light level conditions that the photon flux will statistically provide only a single photon at a time incident on anyone detector diode during any clock cycle.

Dark-count-less photon-counting x-ray computed tomography system using a YAP-MPPC detector

NASA Astrophysics Data System (ADS)

Sato, Eiichi; Sato, Yuich; Abudurexiti, Abulajiang; Hagiwara, Osahiko; Matsukiyo, Hiroshi; Osawa, Akihiro; Enomoto, Toshiyuki; Watanabe, Manabu; Kusachi, Shinya; Sato, Shigehiro; Ogawa, Akira; Onagawa, Jun

2012-10-01

A high-sensitive X-ray computed tomography (CT) system is useful for decreasing absorbed dose for patients, and a dark-count-less photon-counting CT system was developed. X-ray photons are detected using a YAP(Ce) [cerium-doped yttrium aluminum perovskite] single crystal scintillator and an MPPC (multipixel photon counter). Photocurrents are amplified by a high-speed current-voltage amplifier, and smooth event pulses from an integrator are sent to a high-speed comparator. Then, logical pulses are produced from the comparator and are counted by a counter card. Tomography is accomplished by repeated linear scans and rotations of an object, and projection curves of the object are obtained by the linear scan. The image contrast of gadolinium medium slightly fell with increase in lower-level voltage (Vl) of the comparator. The dark count rate was 0 cps, and the count rate for the CT was approximately 250 kcps.

Quantum model of light transmission in array waveguide gratings.

PubMed

Capmany, J; Mora, J; Fernández-Pousa, C R; Muñoz, P

2013-06-17

We develop, to the best of our knowledge, the first model for an array waveguide grating (AWG) device subject to quantum inputs and analyze its basic transformation functionalities for single-photon states. A commercial, cyclic AWG is experimentally characterized with weak input coherent states as a means of exploring its behaviour under realistic quantum detection. In particular it is shown the existence of a cutoff value of the average photon number below which quantum crosstalk between AWG ports is negligible with respect to dark counts. These results can be useful when considering the application of AWG devices to integrated quantum photonic systems.

Montana Kids Count Data Book and County Profiles, 1994.

ERIC Educational Resources Information Center

Healthy Mothers, Healthy Babies--The Montana Coalition, Helena.

This Kids Count publication is the first to examine statewide trends in the well-being of Montana's children. The statistical portrait is based on 13 indicators of well-being: (1) low birthweight rate; (2) infant mortality rate; (3) child death rate; (4) teen violent death rate; (5) percent of public school enrollment in Chapter 1 programs; (6)…

A real-time phoneme counting algorithm and application for speech rate monitoring.

PubMed

Aharonson, Vered; Aharonson, Eran; Raichlin-Levi, Katia; Sotzianu, Aviv; Amir, Ofer; Ovadia-Blechman, Zehava

2017-03-01

Adults who stutter can learn to control and improve their speech fluency by modifying their speaking rate. Existing speech therapy technologies can assist this practice by monitoring speaking rate and providing feedback to the patient, but cannot provide an accurate, quantitative measurement of speaking rate. Moreover, most technologies are too complex and costly to be used for home practice. We developed an algorithm and a smartphone application that monitor a patient's speaking rate in real time and provide user-friendly feedback to both patient and therapist. Our speaking rate computation is performed by a phoneme counting algorithm which implements spectral transition measure extraction to estimate phoneme boundaries. The algorithm is implemented in real time in a mobile application that presents its results in a user-friendly interface. The application incorporates two modes: one provides the patient with visual feedback of his/her speech rate for self-practice and another provides the speech therapist with recordings, speech rate analysis and tools to manage the patient's practice. The algorithm's phoneme counting accuracy was validated on ten healthy subjects who read a paragraph at slow, normal and fast paces, and was compared to manual counting of speech experts. Test-retest and intra-counter reliability were assessed. Preliminary results indicate differences of -4% to 11% between automatic and human phoneme counting. Differences were largest for slow speech. The application can thus provide reliable, user-friendly, real-time feedback for speaking rate control practice. Copyright © 2017 Elsevier Inc. All rights reserved.

Testing the hierarchical assembly of massive galaxies using accurate merger rates out to z ˜ 1.5

NASA Astrophysics Data System (ADS)

Rodrigues, Myriam; Puech, M.; Flores, H.; Hammer, F.; Pirzkal, N.

2018-04-01

We established an accurate comparison between observationally and theoretically estimated major merger rates over a large range of mass (log Mbar/M⊙ =9.9-11.4) and redshift (z = 0.7-1.6). For this, we combined a new estimate of the merger rate from an exhaustive count of pairs within the virial radius of massive galaxies at z ˜ 1.265 and cross-validated with their morphology, with estimates from the morpho-kinematic analysis of two other samples. Theoretical predictions were estimated using semi-empirical models with inputs matching the properties of the observed samples, while specific visibility time-scales scaled to the observed samples were used. Both theory and observations are found to agree within 30 per cent of the observed value, which provides strong support to the hierarchical assembly of galaxies over the probed ranges of mass and redshift. Here, we find that ˜60 per cent of population of local massive (Mstellar =1010.3-11.6 M⊙) galaxies would have undergone a wet major merger since z = 1.5, consistently with previous studies. Such recent mergers are expected to result in the (re-)formation of a significant fraction of local disc galaxies.

HgCdTe APD-based linear-mode photon counting components and ladar receivers

NASA Astrophysics Data System (ADS)

Jack, Michael; Wehner, Justin; Edwards, John; Chapman, George; Hall, Donald N. B.; Jacobson, Shane M.

2011-05-01

Linear mode photon counting (LMPC) provides significant advantages in comparison with Geiger Mode (GM) Photon Counting including absence of after-pulsing, nanosecond pulse to pulse temporal resolution and robust operation in the present of high density obscurants or variable reflectivity objects. For this reason Raytheon has developed and previously reported on unique linear mode photon counting components and modules based on combining advanced APDs and advanced high gain circuits. By using HgCdTe APDs we enable Poisson number preserving photon counting. A metric of photon counting technology is dark count rate and detection probability. In this paper we report on a performance breakthrough resulting from improvement in design, process and readout operation enabling >10x reduction in dark counts rate to ~10,000 cps and >104x reduction in surface dark current enabling long 10 ms integration times. Our analysis of key dark current contributors suggest that substantial further reduction in DCR to ~ 1/sec or less can be achieved by optimizing wavelength, operating voltage and temperature.

Linking reproduction and survival can improve model estimates of vital rates derived from limited time-series counts of pinnipeds and other species.

PubMed

Battaile, Brian C; Trites, Andrew W

2013-01-01

We propose a method to model the physiological link between somatic survival and reproductive output that reduces the number of parameters that need to be estimated by models designed to determine combinations of birth and death rates that produce historic counts of animal populations. We applied our Reproduction and Somatic Survival Linked (RSSL) method to the population counts of three species of North Pacific pinnipeds (harbor seals, Phoca vitulina richardii (Gray, 1864); northern fur seals, Callorhinus ursinus (L., 1758); and Steller sea lions, Eumetopias jubatus (Schreber, 1776))--and found our model outperformed traditional models when fitting vital rates to common types of limited datasets, such as those from counts of pups and adults. However, our model did not perform as well when these basic counts of animals were augmented with additional observations of ratios of juveniles to total non-pups. In this case, the failure of the ratios to improve model performance may indicate that the relationship between survival and reproduction is redefined or disassociated as populations change over time or that the ratio of juveniles to total non-pups is not a meaningful index of vital rates. Overall, our RSSL models show advantages to linking survival and reproduction within models to estimate the vital rates of pinnipeds and other species that have limited time-series of counts.

A Method for Extracting the Free Energy Surface and Conformational Dynamics of Fast-Folding Proteins from Single Molecule Photon Trajectories

PubMed Central

2015-01-01

Single molecule fluorescence spectroscopy holds the promise of providing direct measurements of protein folding free energy landscapes and conformational motions. However, fulfilling this promise has been prevented by technical limitations, most notably, the difficulty in analyzing the small packets of photons per millisecond that are typically recorded from individual biomolecules. Such limitation impairs the ability to accurately determine conformational distributions and resolve sub-millisecond processes. Here we develop an analytical procedure for extracting the conformational distribution and dynamics of fast-folding proteins directly from time-stamped photon arrival trajectories produced by single molecule FRET experiments. Our procedure combines the maximum likelihood analysis originally developed by Gopich and Szabo with a statistical mechanical model that describes protein folding as diffusion on a one-dimensional free energy surface. Using stochastic kinetic simulations, we thoroughly tested the performance of the method in identifying diverse fast-folding scenarios, ranging from two-state to one-state downhill folding, as a function of relevant experimental variables such as photon count rate, amount of input data, and background noise. The tests demonstrate that the analysis can accurately retrieve the original one-dimensional free energy surface and microsecond folding dynamics in spite of the sub-megahertz photon count rates and significant background noise levels of current single molecule fluorescence experiments. Therefore, our approach provides a powerful tool for the quantitative analysis of single molecule FRET experiments of fast protein folding that is also potentially extensible to the analysis of any other biomolecular process governed by sub-millisecond conformational dynamics. PMID:25988351

The Effect of Weld Reinforcement and Post-Welding Cooling Cycles on Fatigue Strength of Butt-Welded Joints under Cyclic Tensile Loading.

PubMed

Araque, Oscar; Arzola, Nelson; Hernández, Edgar

2018-04-12

This research deals with the fatigue behavior of butt-welded joints, by considering the geometry and post-welding cooling cycles, as a result of cooling in quiet air and immersed in water. ASTM A-36 HR structural steel was used as the base metal for the shielded metal arc welding (SMAW) process with welding electrode E6013. The welding reinforcement was 1 mm and 3 mm, respectively; axial fatigue tests were carried out to determine the life and behavior in cracks propagation of the tested welded joints, mechanical characterization tests of properties in welded joints such as microhardness, Charpy impact test and metallographic analysis were carried out. The latter were used as input for the analysis by finite elements which influence the initiation and propagation of cracks and the evaluation of stress intensity factors (SIF). The latter led to obtaining the crack propagation rate and the geometric factor. The tested specimens were analyzed, by taking photographs of the cracks at its beginning in order to make a count of the marks at the origin of the crack. From the results obtained and the marks count, the fatigue crack growth rate and the influence of the cooling media on the life of the welded joint are validated, according to the experimental results. It can be concluded that the welded joints with a higher weld reinforcement have a shorter fatigue life. This is due to the stress concentration that occurs in the vicinity of the weld toe.

The Effect of Weld Reinforcement and Post-Welding Cooling Cycles on Fatigue Strength of Butt-Welded Joints under Cyclic Tensile Loading

PubMed Central

Arzola, Nelson; Hernández, Edgar

2018-01-01

This research deals with the fatigue behavior of butt-welded joints, by considering the geometry and post-welding cooling cycles, as a result of cooling in quiet air and immersed in water. ASTM A-36 HR structural steel was used as the base metal for the shielded metal arc welding (SMAW) process with welding electrode E6013. The welding reinforcement was 1 mm and 3 mm, respectively; axial fatigue tests were carried out to determine the life and behavior in cracks propagation of the tested welded joints, mechanical characterization tests of properties in welded joints such as microhardness, Charpy impact test and metallographic analysis were carried out. The latter were used as input for the analysis by finite elements which influence the initiation and propagation of cracks and the evaluation of stress intensity factors (SIF). The latter led to obtaining the crack propagation rate and the geometric factor. The tested specimens were analyzed, by taking photographs of the cracks at its beginning in order to make a count of the marks at the origin of the crack. From the results obtained and the marks count, the fatigue crack growth rate and the influence of the cooling media on the life of the welded joint are validated, according to the experimental results. It can be concluded that the welded joints with a higher weld reinforcement have a shorter fatigue life. This is due to the stress concentration that occurs in the vicinity of the weld toe. PMID:29649117

A Method for Extracting the Free Energy Surface and Conformational Dynamics of Fast-Folding Proteins from Single Molecule Photon Trajectories.

PubMed

Ramanathan, Ravishankar; Muñoz, Victor

2015-06-25

Single molecule fluorescence spectroscopy holds the promise of providing direct measurements of protein folding free energy landscapes and conformational motions. However, fulfilling this promise has been prevented by technical limitations, most notably, the difficulty in analyzing the small packets of photons per millisecond that are typically recorded from individual biomolecules. Such limitation impairs the ability to accurately determine conformational distributions and resolve sub-millisecond processes. Here we develop an analytical procedure for extracting the conformational distribution and dynamics of fast-folding proteins directly from time-stamped photon arrival trajectories produced by single molecule FRET experiments. Our procedure combines the maximum likelihood analysis originally developed by Gopich and Szabo with a statistical mechanical model that describes protein folding as diffusion on a one-dimensional free energy surface. Using stochastic kinetic simulations, we thoroughly tested the performance of the method in identifying diverse fast-folding scenarios, ranging from two-state to one-state downhill folding, as a function of relevant experimental variables such as photon count rate, amount of input data, and background noise. The tests demonstrate that the analysis can accurately retrieve the original one-dimensional free energy surface and microsecond folding dynamics in spite of the sub-megahertz photon count rates and significant background noise levels of current single molecule fluorescence experiments. Therefore, our approach provides a powerful tool for the quantitative analysis of single molecule FRET experiments of fast protein folding that is also potentially extensible to the analysis of any other biomolecular process governed by sub-millisecond conformational dynamics.

Efficiency of synaptic transmission of single-photon events from rod photoreceptor to rod bipolar dendrite.

PubMed

Schein, Stan; Ahmad, Kareem M

2006-11-01

A rod transmits absorption of a single photon by what appears to be a small reduction in the small number of quanta of neurotransmitter (Q(count)) that it releases within the integration period ( approximately 0.1 s) of a rod bipolar dendrite. Due to the quantal and stochastic nature of release, discrete distributions of Q(count) for darkness versus one isomerization of rhodopsin (R*) overlap. We suggested that release must be regular to narrow these distributions, reduce overlap, reduce the rate of false positives, and increase transmission efficiency (the fraction of R* events that are identified as light). Unsurprisingly, higher quantal release rates (Q(rates)) yield higher efficiencies. Focusing here on the effect of small changes in Q(rate), we find that a slightly higher Q(rate) yields greatly reduced efficiency, due to a necessarily fixed quantal-count threshold. To stabilize efficiency in the face of drift in Q(rate), the dendrite needs to regulate the biochemical realization of its quantal-count threshold with respect to its Q(count). These considerations reveal the mathematical role of calcium-based negative feedback and suggest a helpful role for spontaneous R*. In addition, to stabilize efficiency in the face of drift in degree of regularity, efficiency should be approximately 50%, similar to measurements.

Counting Jobs and Economic Impacts from Distributed Wind in the United States (Poster)

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

Tegen, S.

This conference poster describes the distributed wind Jobs and Economic Development Imapcts (JEDI) model. The goal of this work is to provide a model that estimates jobs and other economic effects associated with the domestic distributed wind industry. The distributed wind JEDI model is a free input-output model that estimates employment and other impacts resulting from an investment in distributed wind installations. Default inputs are from installers and industry experts and are based on existing projects. User input can be minimal (use defaults) or very detailed for more precise results. JEDI can help evaluate potential scenarios, current or future; informmore » stakeholders and decision-makers; assist businesses in evaluating economic development impacts and estimating jobs; assist government organizations with planning and evaluating and developing communities.« less

Recursive Feature Extraction in Graphs

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

2014-08-14

ReFeX extracts recursive topological features from graph data. The input is a graph as a csv file and the output is a csv file containing feature values for each node in the graph. The features are based on topological counts in the neighborhoods of each nodes, as well as recursive summaries of neighbors' features.

NON-BLOCKING STABILIZED FEED BACK AMPLIFIER

DOEpatents

Fairstein, E.

1960-03-01

A plural stuge nonblocking degenerative feed-back amplifier was designed particularly suitable for counting circuits because of the stability and linearity in operation, characterized by the fact that the inltial stage employs a cathode coupled input circuit fed from a cathode follower and the final stage has a tline constant greater than those of the other stages.

Balanced Synaptic Input Shapes the Correlation between Neural Spike Trains

PubMed Central

Litwin-Kumar, Ashok; Oswald, Anne-Marie M.; Urban, Nathaniel N.; Doiron, Brent

2011-01-01

Stimulus properties, attention, and behavioral context influence correlations between the spike times produced by a pair of neurons. However, the biophysical mechanisms that modulate these correlations are poorly understood. With a combined theoretical and experimental approach, we show that the rate of balanced excitatory and inhibitory synaptic input modulates the magnitude and timescale of pairwise spike train correlation. High rate synaptic inputs promote spike time synchrony rather than long timescale spike rate correlations, while low rate synaptic inputs produce opposite results. This correlation shaping is due to a combination of enhanced high frequency input transfer and reduced firing rate gain in the high input rate state compared to the low state. Our study extends neural modulation from single neuron responses to population activity, a necessary step in understanding how the dynamics and processing of neural activity change across distinct brain states. PMID:22215995

Modal Logics with Counting

NASA Astrophysics Data System (ADS)

Areces, Carlos; Hoffmann, Guillaume; Denis, Alexandre

We present a modal language that includes explicit operators to count the number of elements that a model might include in the extension of a formula, and we discuss how this logic has been previously investigated under different guises. We show that the language is related to graded modalities and to hybrid logics. We illustrate a possible application of the language to the treatment of plural objects and queries in natural language. We investigate the expressive power of this logic via bisimulations, discuss the complexity of its satisfiability problem, define a new reasoning task that retrieves the cardinality bound of the extension of a given input formula, and provide an algorithm to solve it.

PHASE DIFFERENTIAL INDICATING CIRCUIT

DOEpatents

Kirsten, F.A.

1962-01-01

An electronic circuit for totalizing the net phase difference between two alternating current signals is designed which responds to both increasing and decreasing phase changes. A phase comparator provldes an output pulse for each 360 deg of phase difference occurring, there being a negative pulse for phase shtft in one direction and a positive pulse for a phase shift in the opposite direction. A counting circuit utilizing glow discharge tubes receives the negative and positive pulses at a single input terminal and provides a running net total, pulses of one polarity dded and pulses of the opposite polarity being subtracted. The glow discharge tubes may be decaded to increase the total count capacity. (AEC)

Comparison of (14)C liquid scintillation counting at NIST and NRC Canada.

PubMed

Bergeron, Denis E; Galea, Raphael; Laureano-Pérez, Lizbeth; Zimmerman, Brian E

2016-03-01

An informal bilateral comparison of (14)C liquid scintillation (LS) counting at the National Research Council of Canada (NRC) and the National Institute of Standards and Technology (NIST) has been completed. Two solutions, one containing (14)C-labeled sodium benzoate and one containing (14)C-labeled n-hexadecane, were measured at both laboratories. Despite observed LS cocktail instabilities, the two laboratories achieved accord in their standardizations of both solutions. At the conclusion of the comparison, the beta spectrum used for efficiency calculations was identified as inadequate and the data were reanalyzed with different inputs, improving accord. Published by Elsevier Ltd.

Refractory pulse counting processes in stochastic neural computers.

PubMed

McNeill, Dean K; Card, Howard C

2005-03-01

This letter quantitiatively investigates the effect of a temporary refractory period or dead time in the ability of a stochastic Bernoulli processor to record subsequent pulse events, following the arrival of a pulse. These effects can arise in either the input detectors of a stochastic neural network or in subsequent processing. A transient period is observed, which increases with both the dead time and the Bernoulli probability of the dead-time free system, during which the system reaches equilibrium. Unless the Bernoulli probability is small compared to the inverse of the dead time, the mean and variance of the pulse count distributions are both appreciably reduced.

High Resolution Gamma Ray Spectroscopy at MHz Counting Rates With LaBr3 Scintillators for Fusion Plasma Applications

NASA Astrophysics Data System (ADS)

Nocente, M.; Tardocchi, M.; Olariu, A.; Olariu, S.; Pereira, R. C.; Chugunov, I. N.; Fernandes, A.; Gin, D. B.; Grosso, G.; Kiptily, V. G.; Neto, A.; Shevelev, A. E.; Silva, M.; Sousa, J.; Gorini, G.

2013-04-01

High resolution γ-ray spectroscopy measurements at MHz counting rates were carried out at nuclear accelerators, combining a LaBr 3(Ce) detector with dedicated hardware and software solutions based on digitization and off-line analysis. Spectra were measured at counting rates up to 4 MHz, with little or no degradation of the energy resolution, adopting a pile up rejection algorithm. The reported results represent a step forward towards the final goal of high resolution γ-ray spectroscopy measurements on a burning plasma device.

Network and neuronal membrane properties in hybrid networks reciprocally regulate selectivity to rapid thalamocortical inputs.

PubMed

Pesavento, Michael J; Pinto, David J

2012-11-01

Rapidly changing environments require rapid processing from sensory inputs. Varying deflection velocities of a rodent's primary facial vibrissa cause varying temporal neuronal activity profiles within the ventral posteromedial thalamic nucleus. Local neuron populations in a single somatosensory layer 4 barrel transform sparsely coded input into a spike count based on the input's temporal profile. We investigate this transformation by creating a barrel-like hybrid network with whole cell recordings of in vitro neurons from a cortical slice preparation, embedding the biological neuron in the simulated network by presenting virtual synaptic conductances via a conductance clamp. Utilizing the hybrid network, we examine the reciprocal network properties (local excitatory and inhibitory synaptic convergence) and neuronal membrane properties (input resistance) by altering the barrel population response to diverse thalamic input. In the presence of local network input, neurons are more selective to thalamic input timing; this arises from strong feedforward inhibition. Strongly inhibitory (damping) network regimes are more selective to timing and less selective to the magnitude of input but require stronger initial input. Input selectivity relies heavily on the different membrane properties of excitatory and inhibitory neurons. When inhibitory and excitatory neurons had identical membrane properties, the sensitivity of in vitro neurons to temporal vs. magnitude features of input was substantially reduced. Increasing the mean leak conductance of the inhibitory cells decreased the network's temporal sensitivity, whereas increasing excitatory leak conductance enhanced magnitude sensitivity. Local network synapses are essential in shaping thalamic input, and differing membrane properties of functional classes reciprocally modulate this effect.

Possible effects of depolarizing GABAA conductance on the neuronal input-output relationship: a modeling study.

PubMed

Morita, Kenji; Tsumoto, Kunichika; Aihara, Kazuyuki

2005-06-01

Recent in vitro experiments revealed that the GABAA reversal potential is about 10 mV higher than the resting potential in mature mammalian neocortical pyramidal cells; thus GABAergic inputs could have facilitatory, rather than inhibitory, effects on action potential generation under certain conditions. However, how the relationship between excitatory input conductances and the output firing rate is modulated by such depolarizing GABAergic inputs under in vivo circumstances has not yet been understood. We examine herewith the input-output relationship in a simple conductance-based model of cortical neurons with the depolarized GABAA reversal potential, and show that a tonic depolarizing GABAergic conductance up to a certain amount does not change the relationship between a tonic glutamatergic driving conductance and the output firing rate, whereas a higher GABAergic conductance prevents spike generation. When the tonic glutamatergic and GABAergic conductances are replaced by in vivo-like highly fluctuating inputs, on the other hand, the effect of depolarizing GABAergic inputs on the input-output relationship critically depends on the degree of coincidence between glutamatergic input events and GABAergic ones. Although a wide range of depolarizing GABAergic inputs hardly changes the firing rate of a neuron driven by noncoincident glutamatergic inputs, a certain range of these inputs considerably decreases the firing rate if a large number of driving glutamatergic inputs are coincident with them. These results raise the possibility that the depolarized GABAA reversal potential is not a paradoxical mystery, but is instead a sophisticated device for discriminative firing rate modulation.

Growth Curve Models for Zero-Inflated Count Data: An Application to Smoking Behavior

ERIC Educational Resources Information Center

Liu, Hui; Powers, Daniel A.

2007-01-01

This article applies growth curve models to longitudinal count data characterized by an excess of zero counts. We discuss a zero-inflated Poisson regression model for longitudinal data in which the impact of covariates on the initial counts and the rate of change in counts over time is the focus of inference. Basic growth curve models using a…

Delayed gamma-ray spectroscopy with lanthanum bromide detector for non-destructive assay of nuclear material

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

Favalli, Andrea; Iliev, Metodi; Ianakiev, Kiril

High-energy delayed γ-ray spectroscopy is a potential technique for directly assaying spent fuel assemblies and achieving the safeguards goal of quantifying nuclear material inventories for spent fuel handling, interim storage, reprocessing facilities, repository sites, and final disposal. Requirements for the γ-ray detection system, up to ~6 MeV, can be summarized as follows: high efficiency at high γ-ray energies, high energy resolution, good linearity between γ-ray energy and output signal amplitude, ability to operate at very high count rates, and ease of use in industrial environments such as nuclear facilities. High Purity Germanium Detectors (HPGe) are the state of the artmore » and provide excellent energy resolution but are limited in their count rate capability. Lanthanum Bromide (LaBr 3) scintillation detectors offer significantly higher count rate capabilities at lower energy resolution. Thus, LaBr 3 detectors may be an effective alternative for nuclear spent-fuel applications, where count-rate capability is a requirement. This paper documents the measured performance of a 2” (length) × 2” (diameter) of LaBr3 scintillation detector system, coupled to a negatively biased PMT and a tapered active high voltage divider, with count-rates up to ~3 Mcps. An experimental methodology was developed that uses the average current from the PMT’s anode and a dual source method to characterize the detector system at specific very high count rate values. Delayed γ-ray spectra were acquired with the LaBr 3 detector system at the Idaho Accelerator Center, Idaho State University, where samples of ~3g of 235U were irradiated with moderated neutrons from a photo-neutron source. Results of the spectroscopy characterization and analysis of the delayed γ-ray spectra acquired indicate the possible use of LaBr3 scintillation detectors when high count rate capability may outweigh the lower energy resolution.« less

Delayed gamma-ray spectroscopy with lanthanum bromide detector for non-destructive assay of nuclear material

DOE PAGES

Favalli, Andrea; Iliev, Metodi; Ianakiev, Kiril; ...

2017-10-09

High-energy delayed γ-ray spectroscopy is a potential technique for directly assaying spent fuel assemblies and achieving the safeguards goal of quantifying nuclear material inventories for spent fuel handling, interim storage, reprocessing facilities, repository sites, and final disposal. Requirements for the γ-ray detection system, up to ~6 MeV, can be summarized as follows: high efficiency at high γ-ray energies, high energy resolution, good linearity between γ-ray energy and output signal amplitude, ability to operate at very high count rates, and ease of use in industrial environments such as nuclear facilities. High Purity Germanium Detectors (HPGe) are the state of the artmore » and provide excellent energy resolution but are limited in their count rate capability. Lanthanum Bromide (LaBr 3) scintillation detectors offer significantly higher count rate capabilities at lower energy resolution. Thus, LaBr 3 detectors may be an effective alternative for nuclear spent-fuel applications, where count-rate capability is a requirement. This paper documents the measured performance of a 2” (length) × 2” (diameter) of LaBr3 scintillation detector system, coupled to a negatively biased PMT and a tapered active high voltage divider, with count-rates up to ~3 Mcps. An experimental methodology was developed that uses the average current from the PMT’s anode and a dual source method to characterize the detector system at specific very high count rate values. Delayed γ-ray spectra were acquired with the LaBr 3 detector system at the Idaho Accelerator Center, Idaho State University, where samples of ~3g of 235U were irradiated with moderated neutrons from a photo-neutron source. Results of the spectroscopy characterization and analysis of the delayed γ-ray spectra acquired indicate the possible use of LaBr3 scintillation detectors when high count rate capability may outweigh the lower energy resolution.« less

Delayed gamma-ray spectroscopy with lanthanum bromide detector for non-destructive assay of nuclear material

NASA Astrophysics Data System (ADS)

Favalli, Andrea; Iliev, Metodi; Ianakiev, Kiril; Hunt, Alan W.; Ludewigt, Bernhard

2018-01-01

High-energy delayed γ-ray spectroscopy is a potential technique for directly assaying spent fuel assemblies and achieving the safeguards goal of quantifying nuclear material inventories for spent fuel handling, interim storage, reprocessing facilities, repository sites, and final disposal. Requirements for the γ-ray detection system, up to ∼6 MeV, can be summarized as follows: high efficiency at high γ-ray energies, high energy resolution, good linearity between γ-ray energy and output signal amplitude, ability to operate at very high count rates, and ease of use in industrial environments such as nuclear facilities. High Purity Germanium Detectors (HPGe) are the state of the art and provide excellent energy resolution but are limited in their count rate capability. Lanthanum Bromide (LaBr3) scintillation detectors offer significantly higher count rate capabilities at lower energy resolution. Thus, LaBr3 detectors may be an effective alternative for nuclear spent-fuel applications, where count-rate capability is a requirement. This paper documents the measured performance of a 2" (length) × 2" (diameter) of LaBr3 scintillation detector system, coupled to a negatively biased PMT and a tapered active high voltage divider, with count-rates up to ∼3 Mcps. An experimental methodology was developed that uses the average current from the PMT's anode and a dual source method to characterize the detector system at specific very high count rate values. Delayed γ-ray spectra were acquired with the LaBr3 detector system at the Idaho Accelerator Center, Idaho State University, where samples of ∼3g of 235U were irradiated with moderated neutrons from a photo-neutron source. Results of the spectroscopy characterization and analysis of the delayed γ-ray spectra acquired indicate the possible use of LaBr3 scintillation detectors when high count rate capability may outweigh the lower energy resolution.

Kids Count Data Book, 2003: State Profiles of Child Well-Being.

ERIC Educational Resources Information Center

O'Hare, William P.

This Kids Count data book examines national and statewide trends in the well being of the nation's children. Statistical portraits are based on 10 indicators of well being: (1) percent of low birth weight babies; (2) infant mortality rate; (3) child death rate; (4) rate of teen deaths by accident, homicide, and suicide; (5) teen birth rate; (6)…

KIDS COUNT Data Book, 2002: State Profiles of Child Well-Being.

ERIC Educational Resources Information Center

O'Hare, William P.

This KIDS COUNT data book examines national and statewide trends in the well being of the nations children. Statistical portraits are based on 10 indicators of well being: (1) percent of low birth weight babies; (2) infant mortality rate; (3) child death rate; (4) rate of teen deaths by accident, homicide, and suicide; (5) teen birth rate; (6)…

KIDS COUNT Data Book, 2001: State Profiles of Child Well-Being.

ERIC Educational Resources Information Center

Annie E. Casey Foundation, Baltimore, MD.

This Kids Count report examines national and statewide trends in the well-being of the nation's children. The statistical portrait is based on 10 indicators of well being: (1) percent of low birth weight babies; (2) infant mortality rate; (3) child death rate; (4) rate of teen deaths by accident, homicide and suicide; (5) teen birth rate; (6)…

Waveguide integrated low noise NbTiN nanowire single-photon detectors with milli-Hz dark count rate

PubMed Central

Schuck, Carsten; Pernice, Wolfram H. P.; Tang, Hong X.

2013-01-01

Superconducting nanowire single-photon detectors are an ideal match for integrated quantum photonic circuits due to their high detection efficiency for telecom wavelength photons. Quantum optical technology also requires single-photon detection with low dark count rate and high timing accuracy. Here we present very low noise superconducting nanowire single-photon detectors based on NbTiN thin films patterned directly on top of Si3N4 waveguides. We systematically investigate a large variety of detector designs and characterize their detection noise performance. Milli-Hz dark count rates are demonstrated over the entire operating range of the nanowire detectors which also feature low timing jitter. The ultra-low dark count rate, in combination with the high detection efficiency inherent to our travelling wave detector geometry, gives rise to a measured noise equivalent power at the 10−20 W/Hz1/2 level. PMID:23714696

High resolution gamma-ray spectroscopy at high count rates with a prototype High Purity Germanium detector

NASA Astrophysics Data System (ADS)

Cooper, R. J.; Amman, M.; Vetter, K.

2018-04-01

High-resolution gamma-ray spectrometers are required for applications in nuclear safeguards, emergency response, and fundamental nuclear physics. To overcome one of the shortcomings of conventional High Purity Germanium (HPGe) detectors, we have developed a prototype device capable of achieving high event throughput and high energy resolution at very high count rates. This device, the design of which we have previously reported on, features a planar HPGe crystal with a reduced-capacitance strip electrode geometry. This design is intended to provide good energy resolution at the short shaping or digital filter times that are required for high rate operation and which are enabled by the fast charge collection afforded by the planar geometry crystal. In this work, we report on the initial performance of the system at count rates up to and including two million counts per second.

Material screening with HPGe counting station for PandaX experiment

NASA Astrophysics Data System (ADS)

Wang, X.; Chen, X.; Fu, C.; Ji, X.; Liu, X.; Mao, Y.; Wang, H.; Wang, S.; Xie, P.; Zhang, T.

2016-12-01

A gamma counting station based on high-purity germanium (HPGe) detector was set up for the material screening of the PandaX dark matter experiments in the China Jinping Underground Laboratory. Low background gamma rate of 2.6 counts/min within the energy range of 20 to 2700 keV is achieved due to the well-designed passive shield. The sentivities of the HPGe detetector reach mBq/kg level for isotopes like K, U, Th, and even better for Co and Cs, resulted from the low-background rate and the high relative detection efficiency of 175%. The structure and performance of the counting station are described in this article. Detailed counting results for the radioactivity in materials used by the PandaX dark-matter experiment are presented. The upgrading plan of the counting station is also discussed.

RNA-SeQC: RNA-seq metrics for quality control and process optimization.

PubMed

DeLuca, David S; Levin, Joshua Z; Sivachenko, Andrey; Fennell, Timothy; Nazaire, Marc-Danie; Williams, Chris; Reich, Michael; Winckler, Wendy; Getz, Gad

2012-06-01

RNA-seq, the application of next-generation sequencing to RNA, provides transcriptome-wide characterization of cellular activity. Assessment of sequencing performance and library quality is critical to the interpretation of RNA-seq data, yet few tools exist to address this issue. We introduce RNA-SeQC, a program which provides key measures of data quality. These metrics include yield, alignment and duplication rates; GC bias, rRNA content, regions of alignment (exon, intron and intragenic), continuity of coverage, 3'/5' bias and count of detectable transcripts, among others. The software provides multi-sample evaluation of library construction protocols, input materials and other experimental parameters. The modularity of the software enables pipeline integration and the routine monitoring of key measures of data quality such as the number of alignable reads, duplication rates and rRNA contamination. RNA-SeQC allows investigators to make informed decisions about sample inclusion in downstream analysis. In summary, RNA-SeQC provides quality control measures critical to experiment design, process optimization and downstream computational analysis. See www.genepattern.org to run online, or www.broadinstitute.org/rna-seqc/ for a command line tool.

Role of spike-frequency adaptation in shaping neuronal response to dynamic stimuli.

PubMed

Peron, Simon Peter; Gabbiani, Fabrizio

2009-06-01

Spike-frequency adaptation is the reduction of a neuron's firing rate to a stimulus of constant intensity. In the locust, the Lobula Giant Movement Detector (LGMD) is a visual interneuron that exhibits rapid adaptation to both current injection and visual stimuli. Here, a reduced compartmental model of the LGMD is employed to explore adaptation's role in selectivity for stimuli whose intensity changes with time. We show that supralinearly increasing current injection stimuli are best at driving a high spike count in the response, while linearly increasing current injection stimuli (i.e., ramps) are best at attaining large firing rate changes in an adapting neuron. This result is extended with in vivo experiments showing that the LGMD's response to translating stimuli having a supralinear velocity profile is larger than the response to constant or linearly increasing velocity translation. Furthermore, we show that the LGMD's preference for approaching versus receding stimuli can partly be accounted for by adaptation. Finally, we show that the LGMD's adaptation mechanism appears well tuned to minimize sensitivity for the level of basal input.

A large ultra-clean gas system with closed loop for the high-rate Outer Tracker at HERA-B

NASA Astrophysics Data System (ADS)

Hohlmann, Marcus

2003-12-01

The gas system for the Outer Tracker of the HERA-B experiment at DESY produces the desired counting gas mixture Ar/CF 4/CO 2 65:30:5 and circulates it through the detector at a flow rate of 20 m3/ h, i.e. ˜1 vol/ h. It controls flows and regulates pressures in all 26 OTR half-superlayers, purifies the gas upon return from the detector, and automatically performs a quantitative analysis of main and trace (O 2, N 2, H 2O) gas components for the common input and the outputs of all half-superlayers. The first running experience and the strategies employed during system construction to avoid any detector aging possibly induced by the gas system are discussed. The large system with major gas purification stations was constructed using only non-outgassing, "clean" materials and devices, such as stainless steel, PEEK, baked Viton, and metal bellows pumps. An epoxy glue was used extensively as a non-outgassing sealing material in applications with up to 100 bar pressure.

Feasibility of a high-speed gamma-camera design using the high-yield-pileup-event-recovery method.

PubMed

Wong, W H; Li, H; Uribe, J; Baghaei, H; Wang, Y; Yokoyama, S

2001-04-01

Higher count-rate gamma cameras than are currently used are needed if the technology is to fulfill its promise in positron coincidence imaging, radionuclide therapy dosimetry imaging, and cardiac first-pass imaging. The present single-crystal design coupled with conventional detector electronics and the traditional Anger-positioning algorithm hinder higher count-rate imaging because of the pileup of gamma-ray signals in the detector and electronics. At an interaction rate of 2 million events per second, the fraction of nonpileup events is < 20% of the total incident events. Hence, the recovery of pileup events can significantly increase the count-rate capability, increase the yield of imaging photons, and minimize image artifacts associated with pileups. A new technology to significantly enhance the performance of gamma cameras in this area is introduced. We introduce a new electronic design called high-yield-pileup-event-recovery (HYPER) electronics for processing the detector signal in gamma cameras so that the individual gamma energies and positions of pileup events, including multiple pileups, can be resolved and recovered despite the mixing of signals. To illustrate the feasibility of the design concept, we have developed a small gamma-camera prototype with the HYPER-Anger electronics. The camera has a 10 x 10 x 1 cm NaI(Tl) crystal with four photomultipliers. Hot-spot and line sources with very high 99mTc activities were imaged. The phantoms were imaged continuously from 60,000 to 3,500,000 counts per second to illustrate the efficacy of the method as a function of counting rates. At 2-3 million events per second, all phantoms were imaged with little distortion, pileup, and dead-time loss. At these counting rates, multiple pileup events (> or = 3 events piling together) were the predominate occurrences, and the HYPER circuit functioned well to resolve and recover these events. The full width at half maximum of the line-spread function at 3,000,000 counts per second was 1.6 times that at 60,000 counts per second. This feasibility study showed that the HYPER electronic concept works; it can significantly increase the count-rate capability and dose efficiency of gamma cameras. In a larger clinical camera, multiple HYPER-Anger circuits may be implemented to further improve the imaging counting rates that we have shown by multiple times. This technology would facilitate the use of gamma cameras for radionuclide therapy dosimetry imaging, cardiac first-pass imaging, and positron coincidence imaging and the simultaneous acquisition of transmission and emission data using different isotopes with less cross-contamination between transmission and emission data.

Illinois Quality Counts: QRS Profile. The Child Care Quality Rating System (QRS) Assessment

ERIC Educational Resources Information Center

Child Trends, 2010

2010-01-01

This paper presents a profile of Illinois' Quality Counts prepared as part of the Child Care Quality Rating System (QRS) Assessment Study. The profile consists of several sections and their corresponding descriptions including: (1) Program Information; (2) Rating Details; (3) Quality Indicators for Center-Based Programs; (4) Indicators for Family…

Pitch Counts in Youth Baseball and Softball: A Historical Review.

PubMed

Feeley, Brian T; Schisel, Jessica; Agel, Julie

2018-07-01

Pitching injuries are getting increased attention in the mass media. Many references are made to pitch counts and the role they play in injury prevention. The original purpose of regulating the pitch count in youth baseball was to reduce injury and fatigue to pitchers. This article reviews the history and development of the pitch count limit in baseball, the effect it has had on injury, and the evidence regarding injury rates on softball windmill pitching. Literature search through PubMed, mass media, and organizational Web sites through June 2015. Pitch count limits and rest recommendations were introduced in 1996 after a survey of 28 orthopedic surgeons and baseball coaches showed injuries to baseball pitchers' arms were believed to be from the number of pitches thrown. Follow-up research led to revised recommendations with more detailed guidelines in 2006. Since that time, data show a relationship between innings pitched and upper extremity injury, but pitch type has not clearly been shown to affect injury rates. Current surveys of coaches and players show that coaches, parents, and athletes often do not adhere to these guidelines. There are no pitch count guidelines currently available in softball. The increase in participation in youth baseball and softball with an emphasis on early sport specialization in youth sports activities suggests that there will continue to be a rise in injury rates to young throwers. The published pitch counts are likely to positively affect injury rates but must be adhered to by athletes, coaches, and parents.

Broadband high resolution X-ray spectral analyzer

DOEpatents

Silver, Eric H.; Legros, Mark; Madden, Norm W.; Goulding, Fred; Landis, Don

1998-01-01

A broad bandwidth high resolution x-ray fluorescence spectrometer has a performance that is superior in many ways to those currently available. It consists of an array of 4 large area microcalorimeters with 95% quantum efficiency at 6 keV and it produces x-ray spectra between 0.2 keV and 7 keV with an energy resolution of 7 to 10 eV. The resolution is obtained at input count rates per array element of 10 to 50 Hz in real-time, with analog pulse processing and thermal pile-up rejection. This performance cannot be matched by currently available x-ray spectrometers. The detectors are incorporated into a compact and portable cryogenic refrigerator system that is ready for use in many analytical spectroscopy applications as a tool for x-ray microanalysis or in research applications such as laboratory and astrophysical x-ray and particle spectroscopy.

Broadband high resolution X-ray spectral analyzer

DOEpatents

Silver, E.H.; Legros, M.; Madden, N.W.; Goulding, F.; Landis, D.

1998-07-07

A broad bandwidth high resolution X-ray fluorescence spectrometer has a performance that is superior in many ways to those currently available. It consists of an array of 4 large area microcalorimeters with 95% quantum efficiency at 6 keV and it produces X-ray spectra between 0.2 keV and 7 keV with an energy resolution of 7 to 10 eV. The resolution is obtained at input count rates per array element of 10 to 50 Hz in real-time, with analog pulse processing and thermal pile-up rejection. This performance cannot be matched by currently available X-ray spectrometers. The detectors are incorporated into a compact and portable cryogenic refrigerator system that is ready for use in many analytical spectroscopy applications as a tool for X-ray microanalysis or in research applications such as laboratory and astrophysical X-ray and particle spectroscopy. 6 figs.

Characterization of time-resolved fluorescence response measurements for distributed optical-fiber sensing.

PubMed

Sinchenko, Elena; Gibbs, W E Keith; Davis, Claire E; Stoddart, Paul R

2010-11-20

A distributed optical-fiber sensing system based on pulsed excitation and time-gated photon counting has been used to locate a fluorescent region along the fiber. The complex Alq3 and the infrared dye IR-125 were examined with 405 and 780 nm excitation, respectively. A model to characterize the response of the distributed fluorescence sensor to a Gaussian input pulse was developed and tested. Analysis of the Alq3 fluorescent response confirmed the validity of the model and enabled the fluorescence lifetime to be determined. The intrinsic lifetime obtained (18.2±0.9 ns) is in good agreement with published data. The decay rate was found to be proportional to concentration, which is indicative of collisional deactivation. The model allows the spatial resolution of a distributed sensing system to be improved for fluorophores with lifetimes that are longer than the resolution of the sensing system.

An accurate derivation of the air dose-rate and the deposition concentration distribution by aerial monitoring in a low level contaminated area

NASA Astrophysics Data System (ADS)

Nishizawa, Yukiyasu; Sugita, Takeshi; Sanada, Yukihisa; Torii, Tatsuo

2015-04-01

Since 2011, MEXT (Ministry of Education, Culture, Sports, Science and Technology, Japan) have been conducting aerial monitoring to investigate the distribution of radioactive cesium dispersed into the atmosphere after the accident at the Fukushima Dai-ichi Nuclear Power Plant (FDNPP), Tokyo Electric Power Company. Distribution maps of the air dose-rate at 1 m above the ground and the radioactive cesium deposition concentration on the ground are prepared using spectrum obtained by aerial monitoring. The radioactive cesium deposition is derived from its dose rate, which is calculated by excluding the dose rate of the background radiation due to natural radionuclides from the air dose-rate at 1 m above the ground. The first step of the current method of calculating the dose rate due to natural radionuclides is calculate the ratio of the total count rate of areas where no radioactive cesium is detected and the count rate of regions with energy levels of 1,400 keV or higher (BG-Index). Next, calculate the air dose rate of radioactive cesium by multiplying the BG-Index and the integrated count rate of 1,400 keV or higher for the area where the radioactive cesium is distributed. In high dose-rate areas, however, the count rate of the 1,365-keV peak of Cs-134, though small, is included in the integrated count rate of 1,400 keV or higher, which could cause an overestimation of the air dose rate of natural radionuclides. We developed a method for accurately evaluating the distribution maps of natural air dose-rate by excluding the effect of radioactive cesium, even in contaminated areas, and obtained the accurate air dose-rate map attributed the radioactive cesium deposition on the ground. Furthermore, the natural dose-rate distribution throughout Japan has been obtained by this method.

Radiation Discrimination in LiBaF3 Scintillator Using Digital Signal Processing Techniques

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

Aalseth, Craig E.; Bowyer, Sonya M.; Reeder, Paul L.

2002-11-01

The new scintillator material LiBaF3:Ce offers the possibility of measuring neutron or alpha count rates and energy spectra simultaneously while measuring gamma count rates and spectra using a single detector.

259 E Ohio, April 2014, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

The count rates for the sidewalk ranged from 5,600 cpm to 16,800 cpm.There were two locations along Ontario St. with elevated count rates approaching thethreshold limit correlating to 7.1 pCi/g total thorium.

An important step forward in continuous spectroscopic imaging of ionising radiations using ASICs

NASA Astrophysics Data System (ADS)

Fessler, P.; Coffin, J.; Eberlé, H.; de Raad Iseli, C.; Hilt, B.; Huss, D.; Krummenacher, F.; Lutz, J. R.; Prévot, G.; Renouprez, A.; Sigward, M. H.; Schwaller, B.; Voltolini, C.

1999-01-01

Characterization results are given for an original ASIC allowing continuous acquisition of ionising radiation images in spectroscopic mode. Ionising radiation imaging in general and spectroscopic imaging in particular must primarily be guided by the attempt to decrease statistical noise, which requires detection systems designed to allow very high counting rates. Any source of dead time must therefore be avoided. Thus, the use of on-line corrections of the inevitable dispersion of characteristics between the large number of electronic channels of the detection system, shall be precluded. Without claiming to achieve ultimate noise levels, the work described is focused on how to prevent good individual acquisition channel noise performance from being totally destroyed by the dispersion between channels without introducing dead times. With this goal, we developed an automatic charge amplifier output voltage offset compensation system which operates regardless of the cause of the offset (detector or electronic). The main performances of the system are the following: the input equivalent noise charge is 190 e rms (input non connected, peaking time 500 ns), the highest gain is 255 mV/fC, the peaking time is adjustable between 200 ns and 2 μs and the power consumption is 10 mW per channel. The agreement between experimental data and theoretical simulation results is excellent.

Modeling the frequency-dependent detective quantum efficiency of photon-counting x-ray detectors.

PubMed

Stierstorfer, Karl

2018-01-01

To find a simple model for the frequency-dependent detective quantum efficiency (DQE) of photon-counting detectors in the low flux limit. Formula for the spatial cross-talk, the noise power spectrum and the DQE of a photon-counting detector working at a given threshold are derived. Parameters are probabilities for types of events like single counts in the central pixel, double counts in the central pixel and a neighboring pixel or single count in a neighboring pixel only. These probabilities can be derived in a simple model by extensive use of Monte Carlo techniques: The Monte Carlo x-ray propagation program MOCASSIM is used to simulate the energy deposition from the x-rays in the detector material. A simple charge cloud model using Gaussian clouds of fixed width is used for the propagation of the electric charge generated by the primary interactions. Both stages are combined in a Monte Carlo simulation randomizing the location of impact which finally produces the required probabilities. The parameters of the charge cloud model are fitted to the spectral response to a polychromatic spectrum measured with our prototype detector. Based on the Monte Carlo model, the DQE of photon-counting detectors as a function of spatial frequency is calculated for various pixel sizes, photon energies, and thresholds. The frequency-dependent DQE of a photon-counting detector in the low flux limit can be described with an equation containing only a small set of probabilities as input. Estimates for the probabilities can be derived from a simple model of the detector physics. © 2017 American Association of Physicists in Medicine.

Using Crater Counts to Constrain Erosion Rates on Mars: Implications for the Global Dust Cycle, Sedimentary Rock Erosion and Organic Matter Preservation

NASA Astrophysics Data System (ADS)

Mayer, D. P.; Kite, E. S.

2016-12-01

Sandblasting, aeolian infilling, and wind deflation all obliterate impact craters on Mars, complicating the use of crater counts for chronology, particularly on sedimentary rock surfaces. However, crater counts on sedimentary rocks can be exploited to constrain wind erosion rates. Relatively small, shallow craters are preferentially obliterated as a landscape undergoes erosion, so the size-frequency distribution of impact craters in a landscape undergoing steady exhumation will develop a shallower power-law slope than a simple production function. Estimating erosion rates is important for several reasons: (1) Wind erosion is a source of mass for the global dust cycle, so the global dust reservoir will disproportionately sample fast-eroding regions; (2) The pace and pattern of recent wind erosion is a sorely-needed constraint on models of the sculpting of Mars' sedimentary-rock mounds; (3) Near-surface complex organic matter on Mars is destroyed by radiation in <108 years, so high rates of surface exhumation are required for preservation of near-surface organic matter. We use crater counts from 18 HiRISE images over sedimentary rock deposits as the basis for estimating erosion rates. Each image was counted by ≥3 analysts and only features agreed on by ≥2 analysts were included in the erosion rate estimation. Erosion rates range from 0.1-0.2 {μ }m/yr across all images. These rates represent an upper limit on surface erosion by landscape lowering. At the conference we will discuss the within and between-image variability of erosion rates and their implications for recent geological processes on Mars.

Dynamic time-correlated single-photon counting laser ranging

NASA Astrophysics Data System (ADS)

Peng, Huan; Wang, Yu-rong; Meng, Wen-dong; Yan, Pei-qin; Li, Zhao-hui; Li, Chen; Pan, Hai-feng; Wu, Guang

2018-03-01

We demonstrate a photon counting laser ranging experiment with a four-channel single-photon detector (SPD). The multi-channel SPD improve the counting rate more than 4×107 cps, which makes possible for the distance measurement performed even in daylight. However, the time-correlated single-photon counting (TCSPC) technique cannot distill the signal easily while the fast moving targets are submersed in the strong background. We propose a dynamic TCSPC method for fast moving targets measurement by varying coincidence window in real time. In the experiment, we prove that targets with velocity of 5 km/s can be detected according to the method, while the echo rate is 20% with the background counts of more than 1.2×107 cps.

TH-EF-207A-03: Photon Counting Implementation Challenges Using An Electron Multiplying Charged-Coupled Device Based Micro-CT System

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

Podgorsak, A; Bednarek, D; Rudin, S

2016-06-15

Purpose: To successfully implement and operate a photon counting scheme on an electron multiplying charged-coupled device (EMCCD) based micro-CT system. Methods: We built an EMCCD based micro-CT system and implemented a photon counting scheme. EMCCD detectors use avalanche transfer registries to multiply the input signal far above the readout noise floor. Due to intrinsic differences in the pixel array, using a global threshold for photon counting is not optimal. To address this shortcoming, we generated a threshold array based on sixty dark fields (no x-ray exposure). We calculated an average matrix and a variance matrix of the dark field sequence.more » The average matrix was used for the offset correction while the variance matrix was used to set individual pixel thresholds for the photon counting scheme. Three hundred photon counting frames were added for each projection and 360 projections were acquired for each object. The system was used to scan various objects followed by reconstruction using an FDK algorithm. Results: Examination of the projection images and reconstructed slices of the objects indicated clear interior detail free of beam hardening artifacts. This suggests successful implementation of the photon counting scheme on our EMCCD based micro-CT system. Conclusion: This work indicates that it is possible to implement and operate a photon counting scheme on an EMCCD based micro-CT system, suggesting that these devices might be able to operate at very low x-ray exposures in a photon counting mode. Such devices could have future implications in clinical CT protocols. NIH Grant R01EB002873; Toshiba Medical Systems Corp.« less

355 E Riverwalk, February 2017, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

Radiological Survey of Right-of-Way Utility Excavation. The count rates in the excavation ranged from 2,600 cpm to 4,300 cpm. No count rates were found at any time that exceeded the threshold limit of 7,029 cpm.

230 E. Ontario, May 2018, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

Radiological Survey of Right-of-Way Utility Excavation. The count rates in the excavation ranged from 1,800 cpm to 2,600 cpm.No count rates were found at any time that exceeded the threshold limit of 7,366 cpm.

Apparatus and method for temperature correction and expanded count rate of inorganic scintillation detectors

DOEpatents

Ianakiev, Kiril D [Los Alamos, NM; Hsue, Sin Tao [Santa Fe, NM; Browne, Michael C [Los Alamos, NM; Audia, Jeffrey M [Abiquiu, NM

2006-07-25

The present invention includes an apparatus and corresponding method for temperature correction and count rate expansion of inorganic scintillation detectors. A temperature sensor is attached to an inorganic scintillation detector. The inorganic scintillation detector, due to interaction with incident radiation, creates light pulse signals. A photoreceiver processes the light pulse signals to current signals. Temperature correction circuitry that uses a fast light component signal, a slow light component signal, and the temperature signal from the temperature sensor to corrected an inorganic scintillation detector signal output and expanded the count rate.

Machine Learning Based Single-Frame Super-Resolution Processing for Lensless Blood Cell Counting

PubMed Central

Huang, Xiwei; Jiang, Yu; Liu, Xu; Xu, Hang; Han, Zhi; Rong, Hailong; Yang, Haiping; Yan, Mei; Yu, Hao

2016-01-01

A lensless blood cell counting system integrating microfluidic channel and a complementary metal oxide semiconductor (CMOS) image sensor is a promising technique to miniaturize the conventional optical lens based imaging system for point-of-care testing (POCT). However, such a system has limited resolution, making it imperative to improve resolution from the system-level using super-resolution (SR) processing. Yet, how to improve resolution towards better cell detection and recognition with low cost of processing resources and without degrading system throughput is still a challenge. In this article, two machine learning based single-frame SR processing types are proposed and compared for lensless blood cell counting, namely the Extreme Learning Machine based SR (ELMSR) and Convolutional Neural Network based SR (CNNSR). Moreover, lensless blood cell counting prototypes using commercial CMOS image sensors and custom designed backside-illuminated CMOS image sensors are demonstrated with ELMSR and CNNSR. When one captured low-resolution lensless cell image is input, an improved high-resolution cell image will be output. The experimental results show that the cell resolution is improved by 4×, and CNNSR has 9.5% improvement over the ELMSR on resolution enhancing performance. The cell counting results also match well with a commercial flow cytometer. Such ELMSR and CNNSR therefore have the potential for efficient resolution improvement in lensless blood cell counting systems towards POCT applications. PMID:27827837

CORNAS: coverage-dependent RNA-Seq analysis of gene expression data without biological replicates.

PubMed

Low, Joel Z B; Khang, Tsung Fei; Tammi, Martti T

2017-12-28

In current statistical methods for calling differentially expressed genes in RNA-Seq experiments, the assumption is that an adjusted observed gene count represents an unknown true gene count. This adjustment usually consists of a normalization step to account for heterogeneous sample library sizes, and then the resulting normalized gene counts are used as input for parametric or non-parametric differential gene expression tests. A distribution of true gene counts, each with a different probability, can result in the same observed gene count. Importantly, sequencing coverage information is currently not explicitly incorporated into any of the statistical models used for RNA-Seq analysis. We developed a fast Bayesian method which uses the sequencing coverage information determined from the concentration of an RNA sample to estimate the posterior distribution of a true gene count. Our method has better or comparable performance compared to NOISeq and GFOLD, according to the results from simulations and experiments with real unreplicated data. We incorporated a previously unused sequencing coverage parameter into a procedure for differential gene expression analysis with RNA-Seq data. Our results suggest that our method can be used to overcome analytical bottlenecks in experiments with limited number of replicates and low sequencing coverage. The method is implemented in CORNAS (Coverage-dependent RNA-Seq), and is available at https://github.com/joel-lzb/CORNAS .

Relationship between salivary flow rates and Candida counts in subjects with xerostomia.

PubMed

Torres, Sandra R; Peixoto, Camila Bernardo; Caldas, Daniele Manhães; Silva, Eline Barboza; Akiti, Tiyomi; Nucci, Márcio; de Uzeda, Milton

2002-02-01

This study evaluated the relationship between salivary flow and Candida colony counts in the saliva of patients with xerostomia. Sialometry and Candida colony-forming unit (CFU) counts were taken from 112 subjects who reported xerostomia in a questionnaire. Chewing-stimulated whole saliva was collected and streaked in Candida plates and counted in 72 hours. Species identification was accomplished under standard methods. There was a significant inverse relationship between salivary flow and Candida CFU counts (P =.007) when subjects with high colony counts were analyzed (cutoff point of 400 or greater CFU/mL). In addition, the median sialometry of men was significantly greater than that of women (P =.003), even after controlling for confounding variables like underlying disease and medications. Sjögren's syndrome was associated with low salivary flow rate (P =.007). There was no relationship between the median Candida CFU counts and gender or age. There was a high frequency (28%) of mixed colonization. Candida albicans was the most frequent species, followed by C parapsilosis, C tropicalis, and C krusei. In subjects with high Candida CFU counts there was an inverse relationship between salivary flow and Candida CFU counts.

Urban and regional land use analysis: CARETS and census cities experiment package

NASA Technical Reports Server (NTRS)

Alexander, R. (Principal Investigator); Lins, H. F., Jr.; Gallagher, D. B.

1975-01-01

The author has identified the following significant results. Temperatures in degrees Celsius were derived from PCM counts using the Pease's modified gray window technique. The Outcalt simulator was setup on the USGS computer. The input data to the model are basically meteorological and geographical in nature. The output data is presented in three matrices.

The impact of cow nutrient status during the second and third trimesters on age at puberty, antral follicle count, and fertility of daughters

USDA-ARS?s Scientific Manuscript database

Fluctuating feed resources to beef cows across the production cycle is a proven method for decreasing input costs; however, limiting nutrients during late gestation have been demonstrated to decrease ovarian follicle numbers in female offspring in some studies. We hypothesize that limiting nutrients...

Correlation transfer from basal ganglia to thalamus in Parkinson's disease

PubMed Central

Pamela, Reitsma; Brent, Doiron; Jonathan, Rubin

2011-01-01

Spike trains from neurons in the basal ganglia of parkinsonian primates show increased pairwise correlations, oscillatory activity, and burst rate compared to those from neurons recorded during normal brain activity. However, it is not known how these changes affect the behavior of downstream thalamic neurons. To understand how patterns of basal ganglia population activity may affect thalamic spike statistics, we study pairs of model thalamocortical (TC) relay neurons receiving correlated inhibitory input from the internal segment of the globus pallidus (GPi), a primary output nucleus of the basal ganglia. We observe that the strength of correlations of TC neuron spike trains increases with the GPi correlation level, and bursty firing patterns such as those seen in the parkinsonian GPi allow for stronger transfer of correlations than do firing patterns found under normal conditions. We also show that the T-current in the TC neurons does not significantly affect correlation transfer, despite its pronounced effects on spiking. Oscillatory firing patterns in GPi are shown to affect the timescale at which correlations are best transferred through the system. To explain this last result, we analytically compute the spike count correlation coefficient for oscillatory cases in a reduced point process model. Our analysis indicates that the dependence of the timescale of correlation transfer is robust to different levels of input spike and rate correlations and arises due to differences in instantaneous spike correlations, even when the long timescale rhythmic modulations of neurons are identical. Overall, these results show that parkinsonian firing patterns in GPi do affect the transfer of correlations to the thalamus. PMID:22355287

Kids Count Data Sheet, 2000.

ERIC Educational Resources Information Center

Annie E. Casey Foundation, Baltimore, MD.

Data from the 50 United States are listed for 1997 from Kids Count in an effort to track state-by-state the status of children in the United States and to secure better futures for all children. Data include percent low birth weight babies; infant mortality rate; child death rate; rate of teen deaths by accident, homicide, and suicide; teen birth…

Palm Beach Quality Counts: QRS Profile. The Child Care Quality Rating System (QRS) Assessment

ERIC Educational Resources Information Center

Child Trends, 2010

2010-01-01

This paper presents a profile of Palm Beach's Quality Counts prepared as part of the Child Care Quality Rating System (QRS) Assessment Study. The profile consists of several sections and their corresponding descriptions including: (1) Program Information; (2) Rating Details; (3) Quality Indicators for Center-Based Programs; (4) Indicators for…

Miami-Dade Quality Counts: QRS Profile. The Child Care Quality Rating System (QRS) Assessment

ERIC Educational Resources Information Center

Child Trends, 2010

2010-01-01

This paper presents a profile of Miami-Dade's Quality Counts prepared as part of the Child Care Quality Rating System (QRS) Assessment Study. The profile consists of several sections and their corresponding descriptions including: (1) Program Information; (2) Rating Details; (3) Quality Indicators for Center-Based Programs; (4) Indicators for…

Plastic Scintillator Based Detector for Observations of Terrestrial Gamma-ray Flashes.

NASA Astrophysics Data System (ADS)

Barghi, M. R., Sr.; Delaney, N.; Forouzani, A.; Wells, E.; Parab, A.; Smith, D.; Martinez, F.; Bowers, G. S.; Sample, J.

2017-12-01

We present an overview of the concept and design of the Light and Fast TGF Recorder (LAFTR), a balloon borne gamma-ray detector designed to observe Terrestrial Gamma-Ray Flashes (TGFs). Terrestrial Gamma-Ray Flashes (TGFs) are extremely bright, sub-millisecond bursts of gamma-rays observed to originate inside thunderclouds coincident with lightning. LAFTR is joint institutional project built by undergraduates at the University of California Santa Cruz and Montana State University. It consists of a detector system fed into analog front-end electronics and digital processing. The presentation focuses specifically on the UCSC components, which consists of the detector system and analog front-end electronics. Because of the extremely high count rates observed during TGFs, speed is essential for both the detector and electronics of the instrument. The detector employs a fast plastic scintillator (BC-408) read out by a SensL Silicon Photomultiplier (SiPM). BC-408 is chosen for its speed ( 4 ns decay time) and low cost and availability. Furthermore, GEANT3 simulations confirm the scintillator is sensitive to 500 counts at 7 km horizontal distance from the TGF source (for a 13 km source altitude and 26 km balloon altitude) and to 5 counts out to 20 km. The signal from the SiPM has a long exponential decay tail and is sent to a custom shaping circuit board that amplifies and shapes the signal into a semi-Gaussian pulse with a 40 ns FWHM. The signal is then input to a 6-channel discriminator board that clamps the signal and outputs a Low Voltage Differential Signal (LVDS) for processing by the digital electronics.

What Can Quantum Optics Say about Computational Complexity Theory?

NASA Astrophysics Data System (ADS)

Rahimi-Keshari, Saleh; Lund, Austin P.; Ralph, Timothy C.

2015-02-01

Considering the problem of sampling from the output photon-counting probability distribution of a linear-optical network for input Gaussian states, we obtain results that are of interest from both quantum theory and the computational complexity theory point of view. We derive a general formula for calculating the output probabilities, and by considering input thermal states, we show that the output probabilities are proportional to permanents of positive-semidefinite Hermitian matrices. It is believed that approximating permanents of complex matrices in general is a #P-hard problem. However, we show that these permanents can be approximated with an algorithm in the BPPNP complexity class, as there exists an efficient classical algorithm for sampling from the output probability distribution. We further consider input squeezed-vacuum states and discuss the complexity of sampling from the probability distribution at the output.

A Comparison of Bird Detection Rates Derived from On-Road vs. Off-Road Point Counts in Northern Montana

Treesearch

Richard L. Hutto; Sallie J. Hejl; Jeffrey F. Kelly; Sandra M. Pletschet

1995-01-01

We conducted a series of 275 paired (on- and off-road) point counts within 4 distinct vegetation cover types in northwestern Montana. Roadside counts generated a bird list that was essentially the same as the list generated from off-road counts within the same vegetation cover type. Species that were restricted to either on- or off-road counts were rare, suggesting...

Integrated input protection against discharges for Micro Pattern Gas Detectors readout ASICs

NASA Astrophysics Data System (ADS)

Fiutowski, T.; Dąbrowski, W.; Koperny, S.; Wiącek, P.

2017-02-01

Immunity against possible random discharges inside active detector volume of MPGDs is one of the key aspects that should be addressed in the design of the front-end electronics. This issue becomes particularly critical for systems with high channel counts and high density readout employing the front-end electronics built as multichannel ASICs implemented in modern CMOS technologies, for which the breakdown voltages are in the range of a few Volts. The paper presents the design of various input protection structures integrated in the ASIC manufactured in a 350 nm CMOS process and test results using an electrical circuit to mimic discharges in the detectors.

Flow rate calibration to determine cell-derived microparticles and homogeneity of blood components.

PubMed

Noulsri, Egarit; Lerdwana, Surada; Kittisares, Kulvara; Palasuwan, Attakorn; Palasuwan, Duangdao

2017-08-01

Cell-derived microparticles (MPs) are currently of great interest to screening transfusion donors and blood components. However, the current approach to counting MPs is not affordable for routine laboratory use due to its high cost. The current study aimed to investigate the potential use of flow-rate calibration for counting MPs in whole blood, packed red blood cells (PRBCs), and platelet concentrates (PCs). The accuracy of flow-rate calibration was investigated by comparing the platelet counts of an automated counter and a flow-rate calibrator. The concentration of MPs and their origins in whole blood (n=100), PRBCs (n=100), and PCs (n=92) were determined using a FACSCalibur. The MPs' fold-changes were calculated to assess the homogeneity of the blood components. Comparing the platelet counts conducted by automated counting and flow-rate calibration showed an r 2 of 0.6 (y=0.69x+97,620). The CVs of the within-run and between-run variations of flow-rate calibration were 8.2% and 12.1%, respectively. The Bland-Altman plot showed a mean bias of -31,142platelets/μl. MP enumeration revealed both the difference in MP levels and their origins in whole blood, PRBCs, and PCs. Screening the blood components demonstrated high heterogeneity of the MP levels in PCs when compared to whole blood and PRBCs. The results of the present study suggest the accuracy and precision of flow-rate calibration for enumerating MPs. This flow-rate approach is affordable for assessing the homogeneity of MPs in blood components in routine laboratory practice. Copyright © 2017 Elsevier Ltd. All rights reserved.

371 E. Lower Wacker Drive, March 2017, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

Radiological Survey of Right-of-Way Utility Excavation. The count rates in the excavation ranged from 1,600 cpm to 2,600 cpm.No count rates were found at any time that exceeded the threshold limit of 7,029 cpm.

220 E. Illinois St., March 2017, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

Radiological Survey of Right-of-Way Utility Excavation. The count rates in the excavation ranged from 1,500 cpm to 5,600 cpm.No count rates were found at any time that exceeded the threshold limit of 7,029 cpm.

8-37 W. Hubbard, March 2017, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

Radiological Survey of Right-of-Way Utility Excavation. The count rates in the excavation ranged from 1,800 cpm to 5,200 cpm. No count rates were found at any time that exceeded the threshold limit of 7,389 cpm.

429 E. Grand Ave, March 2017, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

Radiological Survey of Right-of-Way Utility Excavation. The count rates in the excavation ranged from 1,700 cpm to 3,700 cpm.No count rates were found at any time that exceeded the threshold limit of 7,029 cpm.

201-211 E. Grand Ave, January 2017, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

Radiological Survey of Right-of-Way Utility Excavation. The count rates in the excavation ranged from 1,700 cpm to 3,900 cpm. No count rates were found at any time that exceeded the threshold limit of 7,029 cpm.

230 N. Michigan Ave, April 2018, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

Radiological Survey of Right-of-Way Utility Excavation. The count rates in the excavation ranged from 1,400 cpm to 3,800 cpm. No count rates were found at any time that exceeded the threshold limit of 6,542 cpm.

36 W. Illinois St, March 2017, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

Radiological Survey of Right-of-Way Utility Excavation. The count rates in the excavation ranged from 1,800 cpm to 2,400 cpm.No count rates were found at any time that exceeded the threshold limit of 7,029 cpm.

1-37 W. Hubbard, March 2017, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

Radiological Survey of Right-of-Way Utility Excavation. The count rates in the excavation ranged from 1,800 cpm to 5,000 cpm. No count rates were found at any time that exceeded the threshold limit of 7,389 cpm.

211 E. Ohio St., March 2017, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

Radiological Survey of Right-of-Way Utility Excavation. The count rates in the excavation ranged from 1,700 cpm to 2,300 cpm.No count rates were found at any time that exceeded the threshold limit of 6,338 cpm.

140-200 E. Grand Ave, February 2017, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

Radiological Survey of Right-of-Way Utility Excavation. The count rates in the excavation ranged from 1,700 cpm to 2,400 cpm. No count rates were found at any time that exceeded the threshold limit of 6,738 cpm.

430 N. Michigan Ave, January 2017, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

Radiological Survey of Right-of-Way Utility Excavation. The count rates in the excavation ranged from 1,600 cpm to 2,100 cpm. No count rates were found at any time that exceeded the threshold limit of 6,338 cpm.

401-599 N. Dearborn St., March 2017, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

Radiological Survey of Right-of-Way Utility Excavation, The count rates in the excavation ranged from 1,700 cpm to 5,800 cpm.No count rates were found at any time that exceeded the threshold limit of 6,738 cpm.

Neutronic analysis of the 1D and 1E banks reflux detection system

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

Blanchard, A.

1999-12-21

Two H Canyon neutron monitoring systems for early detection of postulated abnormal reflux conditions in the Second Uranium Cycle 1E and 1D Mixer-Settle Banks have been designed and built. Monte Carlo neutron transport simulations using the general purpose, general geometry, n-particle MCNP code have been performed to model expected response of the monitoring systems to varying conditions.The confirmatory studies documented herein conclude that the 1E and 1D neutron monitoring systems are able to achieve adequate neutron count rates for various neutron source and detector configurations, thereby eliminating excessive integration count time. Neutron count rate sensitivity studies are also performed. Conversely,more » the transport studies concluded that the neutron count rates are statistically insensitive to nitric acid content in the aqueous region and to the transition region length. These studies conclude that the 1E and 1D neutron monitoring systems are able to predict the postulated reflux conditions for all examined perturbations in the neutron source and detector configurations. In the cases examined, the relative change in the neutron count rates due to postulated transitions from normal {sup 235}U concentration levels to reflux levels remain satisfactory detectable.« less

Point Count Length and Detection of Forest Neotropical Migrant Birds

Treesearch

Deanna K. Dawson; David R. Smith; Chandler S. Robbins

1995-01-01

Comparisons of bird abundances among years or among habitats assume that the rates at which birds are detected and counted are constant within species. We use point count data collected in forests of the Mid-Atlantic states to estimate detection probabilities for Neotropical migrant bird species as a function of count length. For some species, significant differences...

A compact 7-cell Si-drift detector module for high-count rate X-ray spectroscopy.

PubMed

Hansen, K; Reckleben, C; Diehl, I; Klär, H

2008-05-01

A new Si-drift detector module for fast X-ray spectroscopy experiments was developed and realized. The Peltier-cooled module comprises a sensor with 7 × 7-mm 2 active area, an integrated circuit for amplification, shaping and detection, storage, and derandomized readout of signal pulses in parallel, and amplifiers for line driving. The compactness and hexagonal shape of the module with a wrench size of 16mm allow very short distances to the specimen and multi-module arrangements. The power dissipation is 186mW. At a shaper peaking time of 190 ns and an integration time of 450 ns an electronic rms noise of ~11 electrons was achieved. When operated at 7 °C, FWHM line widths around 260 and 460 eV (Cu-K α ) were obtained at low rates and at sum-count rates of 1.7 MHz, respectively. The peak shift is below 1% for a broad range of count rates. At 1.7-MHz sum-count rate the throughput loss amounts to 30%.

Acoustic Emission Parameters of Three Gorges Sandstone during Shear Failure

NASA Astrophysics Data System (ADS)

Xu, Jiang; Liu, Yixin; Peng, Shoujian

2016-12-01

In this paper, an experimental investigation of sandstone samples from the Three Gorges during shear failure was conducted using acoustic emission (AE) and direct shear tests. The AE count rate, cumulative AE count, AE energy, and amplitude of the sandstone samples were determined. Then, the relationships among the AE signals and shearing behaviors of the samples were analyzed in order to detect micro-crack initiation and propagation and reflect shear failure. The results indicated that both the shear strength and displacement exhibited a logarithmic relationship with the displacement rate at peak levels of stress. In addition, the various characteristics of the AE signals were apparent in various situations. The AE signals corresponded with the shear stress under different displacement rates. As the displacement rate increased, the amount of accumulative damage to each specimen decreased, while the AE energy peaked earlier and more significantly. The cumulative AE count primarily increased during the post-peak period. Furthermore, the AE count rate and amplitude exhibited two peaks during the peak shear stress period due to crack coalescence and rock bridge breakage. These isolated cracks later formed larger fractures and eventually caused ruptures.

High-Throughput Quantification of Bacterial-Cell Interactions Using Virtual Colony Counts

PubMed Central

Hoffmann, Stefanie; Walter, Steffi; Blume, Anne-Kathrin; Fuchs, Stephan; Schmidt, Christiane; Scholz, Annemarie; Gerlach, Roman G.

2018-01-01

The quantification of bacteria in cell culture infection models is of paramount importance for the characterization of host-pathogen interactions and pathogenicity factors involved. The standard to enumerate bacteria in these assays is plating of a dilution series on solid agar and counting of the resulting colony forming units (CFU). In contrast, the virtual colony count (VCC) method is a high-throughput compatible alternative with minimized manual input. Based on the recording of quantitative growth kinetics, VCC relates the time to reach a given absorbance threshold to the initial cell count using a series of calibration curves. Here, we adapted the VCC method using the model organism Salmonella enterica sv. Typhimurium (S. Typhimurium) in combination with established cell culture-based infection models. For HeLa infections, a direct side-by-side comparison showed a good correlation of VCC with CFU counting after plating. For MDCK cells and RAW macrophages we found that VCC reproduced the expected phenotypes of different S. Typhimurium mutants. Furthermore, we demonstrated the use of VCC to test the inhibition of Salmonella invasion by the probiotic E. coli strain Nissle 1917. Taken together, VCC provides a flexible, label-free, automation-compatible methodology to quantify bacteria in in vitro infection assays. PMID:29497603

Two-Stage Variable Sample-Rate Conversion System

NASA Technical Reports Server (NTRS)

Tkacenko, Andre

2009-01-01

A two-stage variable sample-rate conversion (SRC) system has been pro posed as part of a digital signal-processing system in a digital com munication radio receiver that utilizes a variety of data rates. The proposed system would be used as an interface between (1) an analog- todigital converter used in the front end of the receiver to sample an intermediatefrequency signal at a fixed input rate and (2) digita lly implemented tracking loops in subsequent stages that operate at v arious sample rates that are generally lower than the input sample r ate. This Two-Stage System would be capable of converting from an input sample rate to a desired lower output sample rate that could be var iable and not necessarily a rational fraction of the input rate.

Laboratory productivity and the rate of manual peripheral blood smear review: a College of American Pathologists Q-Probes study of 95,141 complete blood count determinations performed in 263 institutions.

PubMed

Novis, David A; Walsh, Molly; Wilkinson, David; St Louis, Mary; Ben-Ezra, Jonathon

2006-05-01

Automated laboratory hematology analyzers are capable of performing differential counts on peripheral blood smears with greater precision and more accurate detection of distributional and morphologic abnormalities than those performed by manual examinations of blood smears. Manual determinations of blood morphology and leukocyte differential counts are time-consuming, expensive, and may not always be necessary. The frequency with which hematology laboratory workers perform manual screens despite the availability of labor-saving features of automated analyzers is unknown. To determine the normative rates with which manual peripheral blood smears were performed in clinical laboratories, to examine laboratory practices associated with higher or lower manual review rates, and to measure the effects of manual smear review on the efficiency of generating complete blood count (CBC) determinations. From each of 3 traditional shifts per day, participants were asked to select serially, 10 automated CBC specimens, and to indicate whether manual scans and/or reviews with complete differential counts were performed on blood smears prepared from those specimens. Sampling continued until a total of 60 peripheral smears were reviewed manually. For each specimen on which a manual review was performed, participants indicated the patient's age, hemoglobin value, white blood cell count, platelet count, and the primary reason why the manual review was performed. Participants also submitted data concerning their institutions' demographic profiles and their laboratories' staffing, work volume, and practices regarding CBC determinations. The rates of manual reviews and estimations of efficiency in performing CBC determinations were obtained from the data. A total of 263 hospitals and independent laboratories, predominantly located in the United States, participating in the College of American Pathologists Q-Probes Program. There were 95,141 CBC determinations examined in this study; participants reviewed 15,423 (16.2%) peripheral blood smears manually. In the median institution (50th percentile), manual reviews of peripheral smears were performed on 26.7% of specimens. Manual differential count review rates were inversely associated with the magnitude of platelet counts that were required by laboratory policy to trigger smear reviews and with the efficiency of generating CBC reports. Lower manual differential count review rates were associated with laboratory policies that allowed manual reviews solely on the basis of abnormal automated red cell parameters and that precluded performing repeat manual reviews within designated time intervals. The manual scan rate elevated with increased number of hospital beds. In more than one third (35.7%) of the peripheral smears reviewed manually, participants claimed to have learned additional information beyond what was available on automated hematology analyzer printouts alone. By adopting certain laboratory practices, it may be possible to reduce the rates of manual reviews of peripheral blood smears and increase the efficiency of generating CBC results.

Linear-log counting-rate meter uses transconductance characteristics of a silicon planar transistor

NASA Technical Reports Server (NTRS)

Eichholz, J. J.

1969-01-01

Counting rate meter compresses a wide range of data values, or decades of current. Silicon planar transistor, operating in the zero collector-base voltage mode, is used as a feedback element in an operational amplifier to obtain the log response.

The use of noise equivalent count rate and the NEMA phantom for PET image quality evaluation.

PubMed

Yang, Xin; Peng, Hao

2015-03-01

PET image quality is directly associated with two important parameters among others: count-rate performance and image signal-to-noise ratio (SNR). The framework of noise equivalent count rate (NECR) was developed back in the 1990s and has been widely used since then to evaluate count-rate performance for PET systems. The concept of NECR is not entirely straightforward, however, and among the issues requiring clarification are its original definition, its relationship to image quality, and its consistency among different derivation methods. In particular, we try to answer whether a higher NECR measurement using a standard NEMA phantom actually corresponds to better imaging performance. The paper includes the following topics: 1) revisiting the original analytical model for NECR derivation; 2) validating three methods for NECR calculation based on the NEMA phantom/standard; and 3) studying the spatial dependence of NECR and quantitative relationship between NECR and image SNR. Copyright © 2015 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

Modeling and simulation of count data.

PubMed

Plan, E L

2014-08-13

Count data, or number of events per time interval, are discrete data arising from repeated time to event observations. Their mean count, or piecewise constant event rate, can be evaluated by discrete probability distributions from the Poisson model family. Clinical trial data characterization often involves population count analysis. This tutorial presents the basics and diagnostics of count modeling and simulation in the context of pharmacometrics. Consideration is given to overdispersion, underdispersion, autocorrelation, and inhomogeneity.

Reducing the Teen Death Rate. KIDS COUNT Indicator Brief

ERIC Educational Resources Information Center

Shore, Rima; Shore, Barbara

2009-01-01

Life continues to hold considerable risk for adolescents in the United States. In 2006, the teen death rate stood at 64 deaths per 100,000 teens (13,739 teens) (KIDS COUNT Data Center, 2009). Although it has declined by 4 percent since 2000, the rate of teen death in this country remains substantially higher than in many peer nations, based…

CASA-Mot technology: how results are affected by the frame rate and counting chamber.

PubMed

Bompart, Daznia; García-Molina, Almudena; Valverde, Anthony; Caldeira, Carina; Yániz, Jesús; Núñez de Murga, Manuel; Soler, Carles

2018-04-04

For over 30 years, CASA-Mot technology has been used for kinematic analysis of sperm motility in different mammalian species, but insufficient attention has been paid to the technical limitations of commercial computer-aided sperm analysis (CASA) systems. Counting chamber type and frame rate are two of the most important aspects to be taken into account. Counting chambers can be disposable or reusable, with different depths. In human semen analysis, reusable chambers with a depth of 10µm are the most frequently used, whereas for most farm animal species it is more common to use disposable chambers with a depth of 20µm . The frame rate was previously limited by the hardware, although changes in the number of images collected could lead to significant variations in some kinematic parameters, mainly in curvilinear velocity (VCL). A frame rate of 60 frames s-1 is widely considered to be the minimum necessary for satisfactory results. However, the frame rate is species specific and must be defined in each experimental condition. In conclusion, we show that the optimal combination of frame rate and counting chamber type and depth should be defined for each species and experimental condition in order to obtain reliable results.

Note: Fully integrated active quenching circuit achieving 100 MHz count rate with custom technology single photon avalanche diodes.

PubMed

Acconcia, G; Labanca, I; Rech, I; Gulinatti, A; Ghioni, M

2017-02-01

The minimization of Single Photon Avalanche Diodes (SPADs) dead time is a key factor to speed up photon counting and timing measurements. We present a fully integrated Active Quenching Circuit (AQC) able to provide a count rate as high as 100 MHz with custom technology SPAD detectors. The AQC can also operate the new red enhanced SPAD and provide the timing information with a timing jitter Full Width at Half Maximum (FWHM) as low as 160 ps.

Single-Photon-Sensitive HgCdTe Avalanche Photodiode Detector

NASA Technical Reports Server (NTRS)

Huntington, Andrew

2013-01-01

The purpose of this program was to develop single-photon-sensitive short-wavelength infrared (SWIR) and mid-wavelength infrared (MWIR) avalanche photodiode (APD) receivers based on linear-mode HgCdTe APDs, for application by NASA in light detection and ranging (lidar) sensors. Linear-mode photon-counting APDs are desired for lidar because they have a shorter pixel dead time than Geiger APDs, and can detect sequential pulse returns from multiple objects that are closely spaced in range. Linear-mode APDs can also measure photon number, which Geiger APDs cannot, adding an extra dimension to lidar scene data for multi-photon returns. High-gain APDs with low multiplication noise are required for efficient linear-mode detection of single photons because of APD gain statistics -- a low-excess-noise APD will generate detectible current pulses from single photon input at a much higher rate of occurrence than will a noisy APD operated at the same average gain. MWIR and LWIR electron-avalanche HgCdTe APDs have been shown to operate in linear mode at high average avalanche gain (M > 1000) without excess multiplication noise (F = 1), and are therefore very good candidates for linear-mode photon counting. However, detectors fashioned from these narrow-bandgap alloys require aggressive cooling to control thermal dark current. Wider-bandgap SWIR HgCdTe APDs were investigated in this program as a strategy to reduce detector cooling requirements.

Electron-excited energy dispersive X-ray spectrometry at high speed and at high resolution: silicon drift detectors and microcalorimeters.

PubMed

Newbury, Dale E

2006-12-01

Two recent developments in X-ray spectrometer technology provide dramatic improvements in analytical capabilities that impact the frontiers of electron microscopy. Silicon drift detectors (SDD) use the same physics as silicon (lithium) energy dispersive spectrometers [Si(Li) EDS] but differ in design: only 10% of the thickness of the Si(Li) EDS with an anode area below 0.1 mm2 and a complex rear surface electrode pattern that creates a lateral internal charge collection field. The SDD equals or betters the Si(Li) EDS in most measures of performance. For output versus input count rate, the SDD exceeds the Si(Li) EDS by a factor of 5 to 10 for the same resolution. This high throughput can benefit analytical measurements that are count limited, such as X-ray mapping and trace measurements. The microcalorimeter EDS determines the X-ray energy by measuring the temperature rise in a metal absorber. Operating at 100 mK, the microcalorimeter EDS achieves resolution of 2-5 eV over a photon energy range of 200 eV to 10 keV in energy dispersive operation, eliminating most peak interference situations and providing high peak-to-background to detect low fluorescence yield peaks. Chemical bonding effects on low energy (< 2 keV) peak shapes can be measured.

cnvScan: a CNV screening and annotation tool to improve the clinical utility of computational CNV prediction from exome sequencing data.

PubMed

Samarakoon, Pubudu Saneth; Sorte, Hanne Sørmo; Stray-Pedersen, Asbjørg; Rødningen, Olaug Kristin; Rognes, Torbjørn; Lyle, Robert

2016-01-14

With advances in next generation sequencing technology and analysis methods, single nucleotide variants (SNVs) and indels can be detected with high sensitivity and specificity in exome sequencing data. Recent studies have demonstrated the ability to detect disease-causing copy number variants (CNVs) in exome sequencing data. However, exonic CNV prediction programs have shown high false positive CNV counts, which is the major limiting factor for the applicability of these programs in clinical studies. We have developed a tool (cnvScan) to improve the clinical utility of computational CNV prediction in exome data. cnvScan can accept input from any CNV prediction program. cnvScan consists of two steps: CNV screening and CNV annotation. CNV screening evaluates CNV prediction using quality scores and refines this using an in-house CNV database, which greatly reduces the false positive rate. The annotation step provides functionally and clinically relevant information using multiple source datasets. We assessed the performance of cnvScan on CNV predictions from five different prediction programs using 64 exomes from Primary Immunodeficiency (PIDD) patients, and identified PIDD-causing CNVs in three individuals from two different families. In summary, cnvScan reduces the time and effort required to detect disease-causing CNVs by reducing the false positive count and providing annotation. This improves the clinical utility of CNV detection in exome data.

Neutron counting with cameras

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

Van Esch, Patrick; Crisanti, Marta; Mutti, Paolo

2015-07-01

A research project is presented in which we aim at counting individual neutrons with CCD-like cameras. We explore theoretically a technique that allows us to use imaging detectors as counting detectors at lower counting rates, and transits smoothly to continuous imaging at higher counting rates. As such, the hope is to combine the good background rejection properties of standard neutron counting detectors with the absence of dead time of integrating neutron imaging cameras as well as their very good spatial resolution. Compared to Xray detection, the essence of thermal neutron detection is the nuclear conversion reaction. The released energies involvedmore » are of the order of a few MeV, while X-ray detection releases energies of the order of the photon energy, which is in the 10 KeV range. Thanks to advances in camera technology which have resulted in increased quantum efficiency, lower noise, as well as increased frame rate up to 100 fps for CMOS-type cameras, this more than 100-fold higher available detection energy implies that the individual neutron detection light signal can be significantly above the noise level, as such allowing for discrimination and individual counting, which is hard to achieve with X-rays. The time scale of CMOS-type cameras doesn't allow one to consider time-of-flight measurements, but kinetic experiments in the 10 ms range are possible. The theory is next confronted to the first experimental results. (authors)« less

Photon-Counting Laser Altimeters: Aircraft Demonstration and Future Application to Globally Contiguous Spaceborne Topographic Mapping

NASA Astrophysics Data System (ADS)

Degnan, J. J.

2002-05-01

We have recently demonstrated a scanning, photon-counting, laser altimeter, which is capable of daylight operations from aircraft cruise altitudes. The instrument measures the times-of-flight of individual photons to deduce the distances between the instrument reference and points on the underlying terrain from which the arriving photons were reflected. By imaging the terrain onto a highly pixellated detector followed by a multi-channel timing receiver, one can make multiple spatially-resolved measurements to the surface within a single laser pulse. The horizontal spatial resolution is limited by the optical projection of a single pixel onto the surface. In short, a 3D image of the terrain within the laser ground spot is obtained on each laser fire, assuming at least one signal photon is recorded by each pixel.. In test flights, a prototype airborne system has successfully recorded few kHz rate, single photon returns from clouds, soils, man-made objects, vegetation, and water surfaces at mid-day under conditions of maximum solar illumination. The system has also demonstrated a capability to resolve volumetrically distributed targets, such as tree canopies, and has performed wave height measurements and shallow water bathymetry over the Chesapeake Bay and Atlantic Ocean. The signal photons were reliably extracted from the solar noise background using an optimized Post-Detection Poisson Filter. The passively Q-switched microchip Nd:YAG laser transmitter measures only 2.25 mm in length and is pumped by a single 1.2 Watt laser diode. The output is frequency-doubled to take advantage of higher detector counting efficiencies and narrower spectral filters available at 532 nm. The transmitter produces a few microjoules of green energy in a subnanosecond pulse at several kilohertz rates. The illuminated ground area is imaged by a 14 cm diameter, diffraction-limited, off-axis telescope onto a segmented anode photomultiplier with up to 16 pixels (4 x4). Each anode segment is input to one channel of "fine" range receiver (5 cm detector-limited resolution), which records the times-of-flight of the individual photons. A parallel "coarse" receiver provides a lower resolution (>75 cm) histogram of atmospheric scatterers between the aircraft and ground and centers the "fine" receiver gate on the last set of returns, permitting the fine receiver to lock onto ground features with no a priori range knowledge. Many scientists have expressed a desire for globally contiguous maps of planetary bodies with few meter horizontal spatial resolutions and decimeter vertical resolutions. By sequentially overcoming various technical hurdles to globally contiguous mapping from space, we are led to a conceptual point design for a spaceborne, 3D imaging lidar, which utilizes low energy, high repetition rate lasers, photon-counting detector arrays, multi-channel timing receivers, and a unique optical scanner.

Dead-time correction for high-throughput fluorescence lifetime imaging microscopy (Conference Presentation)

NASA Astrophysics Data System (ADS)

Enderlein, Joerg; Ruhlandt, Daja; Chithik, Anna; Ebrecht, René; Wouters, Fred S.; Gregor, Ingo

2016-02-01

Fluorescence lifetime microscopy has become an important method of bioimaging, allowing not only to record intensity and spectral, but also lifetime information across an image. One of the most widely used methods of FLIM is based on Time-Correlated Single Photon Counting (TCSPC). In TCSPC, one determines this curve by exciting molecules with a periodic train of short laser pulses, and then measuring the time delay between the first recorded fluorescence photon after each exciting laser pulse. An important technical detail of TCSPC measurements is the fact that the delay times between excitation laser pulses and resulting fluorescence photons are always measured between a laser pulse and the first fluorescence photon which is detected after that pulse. At high count rates, this leads to so-called pile-up: ``early'' photons eclipse long-delay photons, resulting in heavily skewed TCSPC histograms. To avoid pile-up, a rule of thumb is to perform TCSPC measurements at photon count rates which are at least hundred times smaller than the laser-pulse excitation rate. The downside of this approach is that the fluorescence-photon count-rate is restricted to a value below one hundredth of the laser-pulse excitation-rate, reducing the overall speed with which a fluorescence signal can be measured. We present a new data evaluation method which provides pile-up corrected fluorescence decay estimates from TCSPC measurements at high count rates, and we demonstrate our method on FLIM of fluorescently labeled cells.

200-300 N. Stetson, January 2017, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

Radiological Survey of Right-of-Way Utility Excavation. The count rates throughout the grading ranged from 4,500 cpm to 8,000 cpm. No count rates were found at any time that exceeded the threshold limits of 17,246 cpm and 18,098 cpm.

0 - 36 W. Illinois St., January 2017, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

Radiological Survey of Right-of-Way Utility Excavation. The count rates in the excavation ranged from 1,600 cpm to 3,700 cpm.No count rates were found at any time that exceeded the threshold limits of 6,738 cpm and 7,029 cpm.

400-449 N. State St, March 2017, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

Radiological Survey of Right-of-Way Utility Excavation. The count rates in the excavation ranged from 1,600 cpm to 4,300 cpm. No count rates were found at any time that exceeded the threshold limits of 6,338 cpm and 7,038 cpm.

Database crime to crime match rate calculation.

PubMed

Buckleton, John; Bright, Jo-Anne; Walsh, Simon J

2009-06-01

Guidance exists on how to count matches between samples in a crime sample database but we are unable to locate a definition of how to estimate a match rate. We propose a method that does not proceed from the match counting definition but which has a strong logic.

Revised SNAP III Training Manual

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

Moss, Calvin Elroy; Gonzales, Samuel M.; Myers, William L.

The Shielded Neutron Assay Probe (SNAP) technique was developed to determine the leakage neutron source strength of a radioactive object. The original system consisted of an Eberline TM Mini-scaler and discrete neutron detector. The system was operated by obtaining the count rate with the Eberline TM instrument, determining the absolute efficiency from a graph, and calculating the neutron source strength by hand. In 2003 the SNAP III, shown in Figure 1, was designed and built. It required the operator to position the SNAP, and then measure the source-to-detector and detectorto- reflector distances. Next the operator entered the distance measurements andmore » started the data acquisition. The SNAP acquired the required count rate and then calculated and displayed the leakage neutron source strength (NSS). The original design of the SNAP III is described in SNAP III Training Manual (ER-TRN-PLN-0258, Rev. 0, January 2004, prepared by William Baird) This report describes some changes that have been made to the SNAP III. One important change is the addition of a LEMO connector to provide neutron detection output pulses for input to the MC-15. This feature is useful in active interrogation with a neutron generator because the MC-15 has the capability to only record data when it is not gated off by a pulse from the neutron generator. This avoids recording of a lot of data during the generator pulses that are not useful. Another change was the replacement of the infrared RS-232 serial communication output by a similar output via a 4-pin LEMO connector. The current document includes a more complete explanation of how to estimate the amount of moderation around a neutron-emitting source.« less

Improving the Accuracy of a Heliocentric Potential (HCP) Prediction Model for the Aviation Radiation Dose

NASA Astrophysics Data System (ADS)

Hwang, Junga; Yoon, Kyoung-Won; Jo, Gyeongbok; Noh, Sung-Jun

2016-12-01

The space radiation dose over air routes including polar routes should be carefully considered, especially when space weather shows sudden disturbances such as coronal mass ejections (CMEs), flares, and accompanying solar energetic particle events. We recently established a heliocentric potential (HCP) prediction model for real-time operation of the CARI-6 and CARI-6M programs. Specifically, the HCP value is used as a critical input value in the CARI-6/6M programs, which estimate the aviation route dose based on the effective dose rate. The CARI-6/6M approach is the most widely used technique, and the programs can be obtained from the U.S. Federal Aviation Administration (FAA). However, HCP values are given at a one month delay on the FAA official webpage, which makes it difficult to obtain real-time information on the aviation route dose. In order to overcome this critical limitation regarding the time delay for space weather customers, we developed a HCP prediction model based on sunspot number variations (Hwang et al. 2015). In this paper, we focus on improvements to our HCP prediction model and update it with neutron monitoring data. We found that the most accurate method to derive the HCP value involves (1) real-time daily sunspot assessments, (2) predictions of the daily HCP by our prediction algorithm, and (3) calculations of the resultant daily effective dose rate. Additionally, we also derived the HCP prediction algorithm in this paper by using ground neutron counts. With the compensation stemming from the use of ground neutron count data, the newly developed HCP prediction model was improved.

45 CFR 261.34 - Are there any limitations in counting job search and job readiness assistance toward the...

Code of Federal Regulations, 2011 CFR

2011-10-01

... 45 Public Welfare 2 2011-10-01 2011-10-01 false Are there any limitations in counting job search and job readiness assistance toward the participation rates? 261.34 Section 261.34 Public Welfare... Work Activities and How Do They Count? § 261.34 Are there any limitations in counting job search and...

45 CFR 261.34 - Are there any limitations in counting job search and job readiness assistance toward the...

Code of Federal Regulations, 2013 CFR

2013-10-01

... 45 Public Welfare 2 2013-10-01 2012-10-01 true Are there any limitations in counting job search and job readiness assistance toward the participation rates? 261.34 Section 261.34 Public Welfare... Work Activities and How Do They Count? § 261.34 Are there any limitations in counting job search and...

45 CFR 261.34 - Are there any limitations in counting job search and job readiness assistance toward the...

Code of Federal Regulations, 2010 CFR

2010-10-01

... 45 Public Welfare 2 2010-10-01 2010-10-01 false Are there any limitations in counting job search and job readiness assistance toward the participation rates? 261.34 Section 261.34 Public Welfare... Work Activities and How Do They Count? § 261.34 Are there any limitations in counting job search and...

45 CFR 261.34 - Are there any limitations in counting job search and job readiness assistance toward the...

Code of Federal Regulations, 2012 CFR

2012-10-01

... 45 Public Welfare 2 2012-10-01 2012-10-01 false Are there any limitations in counting job search and job readiness assistance toward the participation rates? 261.34 Section 261.34 Public Welfare... Work Activities and How Do They Count? § 261.34 Are there any limitations in counting job search and...

45 CFR 261.34 - Are there any limitations in counting job search and job readiness assistance toward the...

Code of Federal Regulations, 2014 CFR

2014-10-01

... 45 Public Welfare 2 2014-10-01 2012-10-01 true Are there any limitations in counting job search and job readiness assistance toward the participation rates? 261.34 Section 261.34 Public Welfare... Work Activities and How Do They Count? § 261.34 Are there any limitations in counting job search and...

Bunch mode specific rate corrections for PILATUS3 detectors

DOE PAGES

Trueb, P.; Dejoie, C.; Kobas, M.; ...

2015-04-09

PILATUS X-ray detectors are in operation at many synchrotron beamlines around the world. This article reports on the characterization of the new PILATUS3 detector generation at high count rates. As for all counting detectors, the measured intensities have to be corrected for the dead-time of the counting mechanism at high photon fluxes. The large number of different bunch modes at these synchrotrons as well as the wide range of detector settings presents a challenge for providing accurate corrections. To avoid the intricate measurement of the count rate behaviour for every bunch mode, a Monte Carlo simulation of the counting mechanismmore » has been implemented, which is able to predict the corrections for arbitrary bunch modes and a wide range of detector settings. This article compares the simulated results with experimental data acquired at different synchrotrons. It is found that the usage of bunch mode specific corrections based on this simulation improves the accuracy of the measured intensities by up to 40% for high photon rates and highly structured bunch modes. For less structured bunch modes, the instant retrigger technology of PILATUS3 detectors substantially reduces the dependency of the rate correction on the bunch mode. The acquired data also demonstrate that the instant retrigger technology allows for data acquisition up to 15 million photons per second per pixel.« less

Phase space representation of neutron monitor count rate and atmospheric electric field in relation to solar activity in cycles 21 and 22.

PubMed

Silva, H G; Lopes, I

Heliospheric modulation of galactic cosmic rays links solar cycle activity with neutron monitor count rate on earth. A less direct relation holds between neutron monitor count rate and atmospheric electric field because different atmospheric processes, including fluctuations in the ionosphere, are involved. Although a full quantitative model is still lacking, this link is supported by solid statistical evidence. Thus, a connection between the solar cycle activity and atmospheric electric field is expected. To gain a deeper insight into these relations, sunspot area (NOAA, USA), neutron monitor count rate (Climax, Colorado, USA), and atmospheric electric field (Lisbon, Portugal) are presented here in a phase space representation. The period considered covers two solar cycles (21, 22) and extends from 1978 to 1990. Two solar maxima were observed in this dataset, one in 1979 and another in 1989, as well as one solar minimum in 1986. Two main observations of the present study were: (1) similar short-term topological features of the phase space representations of the three variables, (2) a long-term phase space radius synchronization between the solar cycle activity, neutron monitor count rate, and potential gradient (confirmed by absolute correlation values above ~0.8). Finally, the methodology proposed here can be used for obtaining the relations between other atmospheric parameters (e.g., solar radiation) and solar cycle activity.

User's Manual for Total-Tree Multiproduct Cruise Program

Treesearch

Alexander Clark; Thomas M. Burgan; Richard C. Field; Peter E. Dress

1985-01-01

This interactive computer program uses standard tree-cruise data to estimate the weight and volume of the total tree, saw logs, plylogs, chipping logs, pulpwood, crown firewood, and logging residue in timber stands.Input is cumulative cruise data for tree counts by d.b.h. and height. Output is in tables: board-foot volume by d.b.h.; total-tree and tree-component...

The prevalence of abnormal leukocyte count, and its predisposing factors, in patients with sickle cell disease in Saudi Arabia.

PubMed

Ahmed, Anwar E; Ali, Yosra Z; Al-Suliman, Ahmad M; Albagshi, Jafar M; Al Salamah, Majid; Elsayid, Mohieldin; Alanazi, Wala R; Ahmed, Rayan A; McClish, Donna K; Al-Jahdali, Hamdan

2017-01-01

High white blood cell (WBC) count is an indicator of sickle cell disease (SCD) severity, however, there are limited studies on WBC counts in Saudi Arabian patients with SCD. The aim of this study was to estimate the prevalence of abnormal leukocyte count (either low or high) and identify factors associated with high WBC counts in a sample of Saudi patients with SCD. A cross-sectional and retrospective chart review study was carried out on 290 SCD patients who were routinely treated at King Fahad Hospital in Hofuf, Saudi Arabia. An interview was conducted to assess clinical presentations, and we reviewed patient charts to collect data on blood test parameters for the previous 6 months. Almost half (131 [45.2%]) of the sample had abnormal leukocyte counts: low WBC counts 15 (5.2%) and high 116 (40%). High WBC counts were associated with shortness of breath ( P =0.022), tiredness ( P =0.039), swelling in hands/feet ( P =0.020), and back pain ( P =0.007). The mean hemoglobin was higher in patients with normal WBC counts ( P =0.024), while the mean hemoglobin S was high in patients with high WBC counts ( P =0.003). After adjustment for potential confounders, predictors of high WBC counts were male gender (adjusted odds ratio [aOR]=3.63) and patients with cough (aOR=2.18), low hemoglobin (aOR=0.76), and low heart rate (aOR=0.97). Abnormal leukocyte count was common: approximately five in ten Saudi SCD patients assessed in this sample. Male gender, cough, low hemoglobin, and low heart rate were associated with high WBC count. Strategies targeting high WBC count could prevent disease complication and thus could be beneficial for SCD patients.

Analysis of overdispersed count data by mixtures of Poisson variables and Poisson processes.

PubMed

Hougaard, P; Lee, M L; Whitmore, G A

1997-12-01

Count data often show overdispersion compared to the Poisson distribution. Overdispersion is typically modeled by a random effect for the mean, based on the gamma distribution, leading to the negative binomial distribution for the count. This paper considers a larger family of mixture distributions, including the inverse Gaussian mixture distribution. It is demonstrated that it gives a significantly better fit for a data set on the frequency of epileptic seizures. The same approach can be used to generate counting processes from Poisson processes, where the rate or the time is random. A random rate corresponds to variation between patients, whereas a random time corresponds to variation within patients.

Hantavirus pulmonary syndrome, United States, 1993-2009.

PubMed

MacNeil, Adam; Ksiazek, Thomas G; Rollin, Pierre E

2011-07-01

Hantavirus pulmonary syndrome (HPS) is a severe respiratory illness identified in 1993. Since its identification, the Centers for Disease Control and Prevention has obtained standardized information about and maintained a registry of all laboratory-confirmed HPS cases in the United States. During 1993-2009, a total of 510 HPS cases were identified. Case counts have varied from 11 to 48 per year (case-fatality rate 35%). However, there were no trends suggesting increasing or decreasing case counts or fatality rates. Although cases were reported in 30 states, most cases occurred in the western half of the country; annual case counts varied most in the southwestern United States. Increased hematocrits, leukocyte counts, and creatinine levels were more common in HPS case-patients who died. HPS is a severe disease with a high case-fatality rate, and cases continue to occur. The greatest potential for high annual HPS incidence exists in the southwestern United States.

Performance characteristics of high-conductivity channel electron multipliers. [as UV and x ray detector

NASA Technical Reports Server (NTRS)

Timothy, J. G.; Bybee, R. L.

1978-01-01

The paper describes a new type of continuous channel multiplier (CEM) fabricated from a low-resistance glass to produce a high-conductivity channel section and thereby obtain a high count-rate capability. The flat-cone cathode configuration of the CEM is specifically designed for the detection of astigmatic exit images from grazing-incidence spectrometers at the optimum angle of illumination for high detection efficiencies at XUV wavelengths. Typical operating voltages are in the range of 2500-2900 V with stable counting plateau slopes in the range 3-6% per 100-V increment. The modal gain at 2800 V was typically in the range (50-80) million. The modal gain falls off at count rates in excess of about 20,000 per sec. The detection efficiency remains essentially constant to count rates in excess of 2 million per sec. Higher detection efficiencies (better than 20%) are obtained by coating the CEM with MgF2. In life tests of coated CEMs, no measurable change in detection efficiency was measured to a total accumulated signal of 2 times 10 to the 11th power counts.

Key Facts about the Children: Florida Kids Count 1994. A Report on the Status of Florida's Children: Volume V.

ERIC Educational Resources Information Center

University of South Florida, Tampa. Florida Center for Children and Youth.

This Kids Count report investigates statewide trends in the well-being of Florida's children. The statistical report is based on 19 indicators of child well being: (1) low birth weight infants; (2) infant mortality rate; (3) child death rate; (4) births to single teens; (5) juvenile violent crime arrest rate; (6) percent graduating from high…

1-99 W. Hubbard St, May 2018, Lindsay Light Radiological Survey

EPA Pesticide Factsheets

Radiological Survey of Right-of-Way Utility Excavation.The count rates in the excavation ranged from 2,100 cpm to 4,200 cpm.No count rates were found at any time that exceeded the instrument specific threshold limits of 7,366 and 6,415 cpm.

Is Parenting Child's Play? Kids Count in Missouri Report on Adolescent Pregnancy.

ERIC Educational Resources Information Center

Citizens for Missouri's Children, St. Louis.

This Kids Count report presents current information on adolescent pregnancy rates in Missouri. Part 1, "Overview of Adolescent Pregnancy in Missouri," discusses the changing pregnancy, abortion, and birth rates for 15- to 19-year-old adolescents, racial differences in pregnancy risk, regional differences suggesting a link between…

Blocking Losses With a Photon Counter

NASA Technical Reports Server (NTRS)

Moision, Burce E.; Piazzolla, Sabino

2012-01-01

It was not known how to assess accurately losses in a communications link due to photodetector blocking, a phenomenon wherein a detector is rendered inactive for a short time after the detection of a photon. When used to detect a communications signal, blocking leads to losses relative to an ideal detector, which may be measured as a reduction in the communications rate for a given received signal power, or an increase in the signal power required to support the same communications rate. This work involved characterizing blocking losses for single detectors and arrays of detectors. Blocking may be mitigated by spreading the signal intensity over an array of detectors, reducing the count rate on any one detector. A simple approximation was made to the blocking loss as a function of the probability that a detector is unblocked at a given time, essentially treating the blocking probability as a scaling of the detection efficiency. An exact statistical characterization was derived for a single detector, and an approximation for multiple detectors. This allowed derivation of several accurate approximations to the loss. Methods were also derived to account for a rise time in recovery, and non-uniform illumination due to diffraction and atmospheric distortion of the phase front. It was assumed that the communications signal is intensity modulated and received by an array of photon-counting photodetectors. For the purpose of this analysis, it was assumed that the detectors are ideal, in that they produce a signal that allows one to reproduce the arrival times of electrons, produced either as photoelectrons or from dark noise, exactly. For single detectors, the performance of the maximum-likelihood (ML) receiver in blocking is illustrated, as well as a maximum-count (MC) receiver, that, when receiving a pulse-position-modulated (PPM) signal, selects the symbol corresponding to the slot with the largest electron count. Whereas the MC receiver saturates at high count rates, the ML receiver may not. The loss in capacity, symbol-error-rate (SER), and count-rate were numerically computed. It was shown that the capacity and symbol-error-rate losses track, whereas the count-rate loss does not generally reflect the SER or capacity loss, as the slot-statistics at the detector output are no longer Poisson. It is also shown that the MC receiver loss may be accurately predicted for dead times on the order of a slot.

Changes in Sensitization Rate to Weed Allergens in Children with Increased Weeds Pollen Counts in Seoul Metropolitan Area

PubMed Central

Kim, Joo-Hwa; Lee, Ha-Baik; Kim, Seong-Won; Kang, Im-Joo; Kook, Myung-Hee; Kim, Bong-Seong; Park, Kang-Seo; Baek, Hey-Sung; Kim, Kyu-Rang; Choi, Young-Jean

2012-01-01

The prevalence of allergic diseases in children has increased for several decades. We evaluated the correlation between pollen count of weeds and their sensitization rate in Seoul, 1997-2009. Airborne particles carrying allergens were collected daily from 3 stations around Seoul. Skin prick tests to pollen were performed on children with allergic diseases. Ragweed pollen gradually increased between 1999 and 2005, decreased after 2005 and plateaued until 2009 (peak counts, 67 in 2003, 145 in 2005 and 83 grains/m3/day in 2007). Japanese hop pollen increased between 2002 and 2009 (peak counts, 212 in 2006 and 492 grains/m3/day in 2009). Sensitization rates to weed pollen, especially ragweed and Japanese hop in children with allergic diseases, increased annually (ragweed, 2.2% in 2000 and 2.8% in 2002; Japanese hop, 1.4% in 2000 and 1.9% in 2002). The age for sensitization to pollen gradually became younger since 2000 (4 to 6 yr of age, 3.5% in 1997 and 6.2% in 2009; 7 to 9 yr of age, 4.2% in 1997 and 6.4% in 2009). In conclusion, sensitization rates for weed pollens increase in Korean children given increasing pollen counts of ragweed and Japanese hop. PMID:22468096

Changes in sensitization rate to weed allergens in children with increased weeds pollen counts in Seoul metropolitan area.

PubMed

Kim, Joo-Hwa; Oh, Jae-Won; Lee, Ha-Baik; Kim, Seong-Won; Kang, Im-Joo; Kook, Myung-Hee; Kim, Bong-Seong; Park, Kang-Seo; Baek, Hey-Sung; Kim, Kyu-Rang; Choi, Young-Jean

2012-04-01

The prevalence of allergic diseases in children has increased for several decades. We evaluated the correlation between pollen count of weeds and their sensitization rate in Seoul, 1997-2009. Airborne particles carrying allergens were collected daily from 3 stations around Seoul. Skin prick tests to pollen were performed on children with allergic diseases. Ragweed pollen gradually increased between 1999 and 2005, decreased after 2005 and plateaued until 2009 (peak counts, 67 in 2003, 145 in 2005 and 83 grains/m(3)/day in 2007). Japanese hop pollen increased between 2002 and 2009 (peak counts, 212 in 2006 and 492 grains/m(3)/day in 2009). Sensitization rates to weed pollen, especially ragweed and Japanese hop in children with allergic diseases, increased annually (ragweed, 2.2% in 2000 and 2.8% in 2002; Japanese hop, 1.4% in 2000 and 1.9% in 2002). The age for sensitization to pollen gradually became younger since 2000 (4 to 6 yr of age, 3.5% in 1997 and 6.2% in 2009; 7 to 9 yr of age, 4.2% in 1997 and 6.4% in 2009). In conclusion, sensitization rates for weed pollens increase in Korean children given increasing pollen counts of ragweed and Japanese hop.

Count trends for migratory Bald Eagles reveal differences between two populations at a spring site along the Lake Ontario shoreline

PubMed Central

2016-01-01

The recovery of Bald Eagles (Haliaeetus leucophalus), after DDT and other organochlorine insecticides were banned in the United States, can be regarded as one of the most iconic success stories resulting from the Endangered Species Act. Interest remains high in the recovery and growth of the Bald Eagle population. Common to evaluating growth and recovery rates are counts at nesting sites and analyses of individuals fledged per season. But this is merely one snapshot that ignores survival rates as eagles grow to maturity. By analyzing indices from migration counts, we get a different snapshot better reflecting the survival of young birds. Different populations of Bald Eagles breed at different sites at different times of the year. Typical migration count analyses do not separate the populations. A separation of two distinct populations can be achieved at spring count sites by taking advantage of the tendency for northern summer breeding birds to migrate north in spring earlier than southern winter breeding birds who disperse north later in spring. In this paper I analyze migratory indices at a spring site along Lake Ontario. The analysis shows that eagles considered to be primarily of the northern summer breeding population showed an estimated growth rate of 5.3 ± 0.85% (SE) per year with 49% of eagles tallied in adult plumage, whereas the migrants considered to be primarily of the southern breeding population had an estimated growth rate of 14.0 ± 1.79% with only 22% in adult plumage. Together these results argue that the populations of southern breeding Bald Eagles are growing at a substantially higher rate than northern breeding eagles. These findings suggest that aggregate population indices for a species at migration counting sites can sometimes obscure important differences among separate populations at any given site and that separating counts by time period can be a useful way to check for differences among sub-populations. PMID:27231647

Cryptographic robustness of a quantum cryptography system using phase-time coding

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

Molotkov, S. N.

2008-01-15

A cryptographic analysis is presented of a new quantum key distribution protocol using phase-time coding. An upper bound is obtained for the error rate that guarantees secure key distribution. It is shown that the maximum tolerable error rate for this protocol depends on the counting rate in the control time slot. When no counts are detected in the control time slot, the protocol guarantees secure key distribution if the bit error rate in the sifted key does not exceed 50%. This protocol partially discriminates between errors due to system defects (e.g., imbalance of a fiber-optic interferometer) and eavesdropping. In themore » absence of eavesdropping, the counts detected in the control time slot are not caused by interferometer imbalance, which reduces the requirements for interferometer stability.« less

Nitrogen balance dynamics during 2000-2010 in the Yangtze River Basin croplands, with special reference to the relative contributions of cropland area and synthetic fertilizer N application rate changes

PubMed Central

Wang, Lijuan; Zhao, He; Robinson, Brian E.

2017-01-01

With the increases of cropland area and fertilizer nitrogen (N) application rate, general N balance characteristics in regional agroecosystems have been widely documented. However, few studies have quantitatively analyzed the drivers of spatial changes in the N budget. We constructed a mass balance model of the N budget at the soil surface using a database of county-level agricultural statistics to analyze N input, output, and proportional contribution of various factors to the overall N input changes in croplands during 2000–2010 in the Yangtze River Basin, the largest basin and the main agricultural production region in China. Over the period investigated, N input increased by 9%. Of this 87% was from fertilizer N input. In the upper and middle reaches of the basin, the increased synthetic fertilizer N application rate accounted for 84% and 76% of the N input increase, respectively, mainly due to increased N input in the cropland that previously had low synthetic fertilizer N application rate. In lower reaches of the basin, mainly due to urbanization, the decrease in cropland area and synthetic fertilizer N application rate nearly equally contributed to decreases in N input. Quantifying spatial N inputs can provide critical managerial information needed to optimize synthetic fertilizer N application rate and monitor the impacts of urbanization on agricultural production, helping to decrease agricultural environment risk and maintain sustainable agricultural production in different areas. PMID:28678841

Nitrogen balance dynamics during 2000-2010 in the Yangtze River Basin croplands, with special reference to the relative contributions of cropland area and synthetic fertilizer N application rate changes.

PubMed

Wang, Lijuan; Zheng, Hua; Zhao, He; Robinson, Brian E

2017-01-01

With the increases of cropland area and fertilizer nitrogen (N) application rate, general N balance characteristics in regional agroecosystems have been widely documented. However, few studies have quantitatively analyzed the drivers of spatial changes in the N budget. We constructed a mass balance model of the N budget at the soil surface using a database of county-level agricultural statistics to analyze N input, output, and proportional contribution of various factors to the overall N input changes in croplands during 2000-2010 in the Yangtze River Basin, the largest basin and the main agricultural production region in China. Over the period investigated, N input increased by 9%. Of this 87% was from fertilizer N input. In the upper and middle reaches of the basin, the increased synthetic fertilizer N application rate accounted for 84% and 76% of the N input increase, respectively, mainly due to increased N input in the cropland that previously had low synthetic fertilizer N application rate. In lower reaches of the basin, mainly due to urbanization, the decrease in cropland area and synthetic fertilizer N application rate nearly equally contributed to decreases in N input. Quantifying spatial N inputs can provide critical managerial information needed to optimize synthetic fertilizer N application rate and monitor the impacts of urbanization on agricultural production, helping to decrease agricultural environment risk and maintain sustainable agricultural production in different areas.

HIGH VOLTAGE GENERATOR

DOEpatents

Zito, G.V.

1959-04-21

This patent relates to high voltage supply circuits adapted for providing operating voltages for GeigerMueller counter tubes, and is especially directed to an arrangement for maintaining uniform voltage under changing conditions of operation. In the usual power supply arrangement for counter tubes the counter voltage is taken from across the power supply output capacitor. If the count rate exceeds the current delivering capaciiy of the capacitor, the capacitor voltage will drop, decreasing the counter voltage. The present invention provides a multivibrator which has its output voltage controlled by a signal proportional to the counting rate. As the counting rate increases beyond the current delivering capacity of the capacitor, the rectified voltage output from the multivibrator is increased to maintain uniform counter voltage.

Effects of Finger Counting on Numerical Development – The Opposing Views of Neurocognition and Mathematics Education

PubMed Central

Moeller, Korbinian; Martignon, Laura; Wessolowski, Silvia; Engel, Joachim; Nuerk, Hans-Christoph

2011-01-01

Children typically learn basic numerical and arithmetic principles using finger-based representations. However, whether or not reliance on finger-based representations is beneficial or detrimental is the subject of an ongoing debate between researchers in neurocognition and mathematics education. From the neurocognitive perspective, finger counting provides multisensory input, which conveys both cardinal and ordinal aspects of numbers. Recent data indicate that children with good finger-based numerical representations show better arithmetic skills and that training finger gnosis, or “finger sense,” enhances mathematical skills. Therefore neurocognitive researchers conclude that elaborate finger-based numerical representations are beneficial for later numerical development. However, research in mathematics education recommends fostering mentally based numerical representations so as to induce children to abandon finger counting. More precisely, mathematics education recommends first using finger counting, then concrete structured representations and, finally, mental representations of numbers to perform numerical operations. Taken together, these results reveal an important debate between neurocognitive and mathematics education research concerning the benefits and detriments of finger-based strategies for numerical development. In the present review, the rationale of both lines of evidence will be discussed. PMID:22144969

Modeling bias and variation in the stochastic processes of small RNA sequencing

PubMed Central

Etheridge, Alton; Sakhanenko, Nikita; Galas, David

2017-01-01

Abstract The use of RNA-seq as the preferred method for the discovery and validation of small RNA biomarkers has been hindered by high quantitative variability and biased sequence counts. In this paper we develop a statistical model for sequence counts that accounts for ligase bias and stochastic variation in sequence counts. This model implies a linear quadratic relation between the mean and variance of sequence counts. Using a large number of sequencing datasets, we demonstrate how one can use the generalized additive models for location, scale and shape (GAMLSS) distributional regression framework to calculate and apply empirical correction factors for ligase bias. Bias correction could remove more than 40% of the bias for miRNAs. Empirical bias correction factors appear to be nearly constant over at least one and up to four orders of magnitude of total RNA input and independent of sample composition. Using synthetic mixes of known composition, we show that the GAMLSS approach can analyze differential expression with greater accuracy, higher sensitivity and specificity than six existing algorithms (DESeq2, edgeR, EBSeq, limma, DSS, voom) for the analysis of small RNA-seq data. PMID:28369495

Attention-related changes in correlated neuronal activity arise from normalization mechanisms

PubMed Central

Verhoef, Bram-Ernst; Maunsell, John H.R.

2017-01-01

Attention is believed to enhance perception by altering the correlations between pairs of neurons. How attention changes neuronal correlations is unknown. Using multi-electrodes in primate visual cortex, we measured spike-count correlations when single or multiple stimuli were presented, and stimuli were attended or unattended. When stimuli were unattended, adding a suppressive, non-preferred, stimulus beside a preferred stimulus increased spike-count correlations between pairs of similarly-tuned neurons, but decreased spike-count correlations between pairs of oppositely-tuned neurons. These changes are explained by a stochastic normalization model containing populations of oppositely-tuned, mutually-suppressive neurons. Importantly, this model also explains why attention decreased (attend preferred stimulus) or increased (attend non-preferred stimulus) correlations: as an indirect consequence of attention-related changes in the inputs to normalization mechanisms. Our findings link normalization mechanisms to correlated neuronal activity and attention, showing that normalization mechanisms shape response correlations and that these correlations change when attention biases normalization mechanisms. PMID:28553943

The Effects of Gamma and Proton Radiation Exposure on Hematopoietic Cell Counts in the Ferret Model

PubMed Central

Sanzari, Jenine K.; Wan, X. Steven; Krigsfeld, Gabriel S.; Wroe, Andrew J.; Gridley, Daila S.; Kennedy, Ann R.

2014-01-01

Exposure to total-body radiation induces hematological changes, which can detriment one's immune response to wounds and infection. Here, the decreases in blood cell counts after acute radiation doses of γ-ray or proton radiation exposure, at the doses and dose-rates expected during a solar particle event (SPE), are reported in the ferret model system. Following the exposure to γ-ray or proton radiation, the ferret peripheral total white blood cell (WBC) and lymphocyte counts decreased whereas neutrophil count increased within 3 hours. At 48 hours after irradiation, the WBC, neutrophil, and lymphocyte counts decreased in a dose-dependent manner but were not significantly affected by the radiation type (γ-rays verses protons) or dose rate (0.5 Gy/minute verses 0.5 Gy/hour). The loss of these blood cells could accompany and contribute to the physiological symptoms of the acute radiation syndrome (ARS). PMID:25356435

Variable input observer for state estimation of high-rate dynamics

NASA Astrophysics Data System (ADS)

Hong, Jonathan; Cao, Liang; Laflamme, Simon; Dodson, Jacob

2017-04-01

High-rate systems operating in the 10 μs to 10 ms timescale are likely to experience damaging effects due to rapid environmental changes (e.g., turbulence, ballistic impact). Some of these systems could benefit from real-time state estimation to enable their full potential. Examples of such systems include blast mitigation strategies, automotive airbag technologies, and hypersonic vehicles. Particular challenges in high-rate state estimation include: 1) complex time varying nonlinearities of system (e.g. noise, uncertainty, and disturbance); 2) rapid environmental changes; 3) requirement of high convergence rate. Here, we propose using a Variable Input Observer (VIO) concept to vary the input space as the event unfolds. When systems experience high-rate dynamics, rapid changes in the system occur. To investigate the VIO's potential, a VIO-based neuro-observer is constructed and studied using experimental data collected from a laboratory impact test. Results demonstrate that the input space is unique to different impact conditions, and that adjusting the input space throughout the dynamic event produces better estimations than using a traditional fixed input space strategy.

Geometric Representation of Association between Categories

ERIC Educational Resources Information Center

Heiser, Willem J.

2004-01-01

Categories can be counted, rated, or ranked, but they cannot be measured. Likewise, persons or individuals can be counted, rated, or ranked, but they cannot be measured either. Nevertheless, psychology has realized early on that it can take an indirect road to measurement: What can be measured is the strength of association between categories in…

Partial-Interval Estimation of Count: Uncorrected and Poisson-Corrected Error Levels

ERIC Educational Resources Information Center

Yoder, Paul J.; Ledford, Jennifer R.; Harbison, Amy L.; Tapp, Jon T.

2018-01-01

A simulation study that used 3,000 computer-generated event streams with known behavior rates, interval durations, and session durations was conducted to test whether the main and interaction effects of true rate and interval duration affect the error level of uncorrected and Poisson-transformed (i.e., "corrected") count as estimated by…

The Objectivity, Reliability, and Validity of the OSU Step Test for College Males

ERIC Educational Resources Information Center

Santa Maria, D. L.; And Others

1976-01-01

The O.S.U. Step Test was administered to 68 male university students to determine the objectivity of three methods of monitering heart rate--subjects count, investigator's count, and ECG records--with results indicating that the investigator was significantly more accurate in heart rate determination than were the subjects. (MB)

Observation of fluctuation of gamma-ray count rate accompanying thunderstorm activity and energy spectrum of gamma rays in the atmosphere up to several kilometers altitude from the ground

NASA Astrophysics Data System (ADS)

Torii, T.; Sanada, Y.; Watanabe, A.

2017-12-01

In the vicinity of the tops of high mountains and in the coastal areas of the Sea of Japan in winter, the generation of high energy photons that lasts more than 100 seconds at the occurrence of thunderclouds has been reported. At the same time, 511 keV gamma rays are also detected. On the other hand, we irradiated a radiosonde equipped with gamma-ray detectors at the time of thunderstorm and observed fluctuation in gamma-ray count-rate. As a result, we found that the gamma-ray count-rate increases significantly near the top of the thundercloud. Therefore, in order to investigate the fluctuation of the energy of the gamma rays, we developed a radiation detector for radiosonde to observe the fluctuation of the low energy gamma-ray spectrum and observed the fluctuation of the gamma-ray spectrum. We will describe the counting rate and spectral fluctuation of gamma-ray detectors for radiosonde observed in the sky in Fukushima prefecture, Japan.

Programmable noise bandwidth reduction by means of digital averaging

NASA Technical Reports Server (NTRS)

Poklemba, John J. (Inventor)

1993-01-01

Predetection noise bandwidth reduction is effected by a pre-averager capable of digitally averaging the samples of an input data signal over two or more symbols, the averaging interval being defined by the input sampling rate divided by the output sampling rate. As the averaged sample is clocked to a suitable detector at a much slower rate than the input signal sampling rate the noise bandwidth at the input to the detector is reduced, the input to the detector having an improved signal to noise ratio as a result of the averaging process, and the rate at which such subsequent processing must operate is correspondingly reduced. The pre-averager forms a data filter having an output sampling rate of one sample per symbol of received data. More specifically, selected ones of a plurality of samples accumulated over two or more symbol intervals are output in response to clock signals at a rate of one sample per symbol interval. The pre-averager includes circuitry for weighting digitized signal samples using stored finite impulse response (FIR) filter coefficients. A method according to the present invention is also disclosed.

29 CFR 778.318 - Productive and nonproductive hours of work.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Special Problems Effect of Failure to Count Or Pay for Certain Working Hours § 778.318 Productive and... Act; such nonproductive working hours must be counted and paid for. (b) Compensation payable for... which such nonproductive hours are properly counted as working time but no special hourly rate is...

Multi-Parameter Linear Least-Squares Fitting to Poisson Data One Count at a Time

NASA Technical Reports Server (NTRS)

Wheaton, W.; Dunklee, A.; Jacobson, A.; Ling, J.; Mahoney, W.; Radocinski, R.

1993-01-01

A standard problem in gamma-ray astronomy data analysis is the decomposition of a set of observed counts, described by Poisson statistics, according to a given multi-component linear model, with underlying physical count rates or fluxes which are to be estimated from the data.

The relationship between pollen count levels and prevalence of Japanese cedar pollinosis in Northeast Japan.

PubMed

Honda, Kohei; Saito, Hidekazu; Fukui, Naoko; Ito, Eiko; Ishikawa, Kazuo

2013-09-01

The prevalence of Japanese cedar (JC) pollinosis in Japanese children is increasing. However, few studies have reported the relationship between pollen count levels and the prevalence of pollinosis. To evaluate the relationship between JC pollen count levels and the prevalence of pollinosis in children, we investigated the sensitization and development of symptoms for JC pollen in two areas of Akita in northeast Japan with contrasting levels of exposure to JC pollen. The study population consisted of 339 elementary school students (10-11 years of age) from the coastal and mountainous areas of Akita in 2005-2006. A questionnaire about symptoms of allergic rhinitis was filled out by the students' parents. A blood sample was taken to determine specific IgE antibodies against five common aeroallergens. The mean pollen count in the mountainous areas was two times higher than that in the coastal areas in 1996-2006. The prevalence rates of nasal allergy symptoms and sensitization for mites were almost the same in both areas. On the other hand, the rates of nasal allergy symptoms and sensitization for JC pollen were significantly higher in the mountainous areas than in the coastal areas. The rate of the development of symptoms among children sensitized for JC pollen was almost the same in both areas. These results suggest that pollen count levels may correlate with the rate of sensitization for JC pollinosis, but may not affect the rate of onset among sensitized children in northeast Japan.

A 48Cycles/MB H.264/AVC Deblocking Filter Architecture for Ultra High Definition Applications

NASA Astrophysics Data System (ADS)

Zhou, Dajiang; Zhou, Jinjia; Zhu, Jiayi; Goto, Satoshi

In this paper, a highly parallel deblocking filter architecture for H.264/AVC is proposed to process one macroblock in 48 clock cycles and give real-time support to QFHD@60fps sequences at less than 100MHz. 4 edge filters organized in 2 groups for simultaneously processing vertical and horizontal edges are applied in this architecture to enhance its throughput. While parallelism increases, pipeline hazards arise owing to the latency of edge filters and data dependency of deblocking algorithm. To solve this problem, a zig-zag processing schedule is proposed to eliminate the pipeline bubbles. Data path of the architecture is then derived according to the processing schedule and optimized through data flow merging, so as to minimize the cost of logic and internal buffer. Meanwhile, the architecture's data input rate is designed to be identical to its throughput, while the transmission order of input data can also match the zig-zag processing schedule. Therefore no intercommunication buffer is required between the deblocking filter and its previous component for speed matching or data reordering. As a result, only one 24×64 two-port SRAM as internal buffer is required in this design. When synthesized with SMIC 130nm process, the architecture costs a gate count of 30.2k, which is competitive considering its high performance.

When the Ostrich-Algorithm Fails: Blanking Method Affects Spike Train Statistics.

PubMed

Joseph, Kevin; Mottaghi, Soheil; Christ, Olaf; Feuerstein, Thomas J; Hofmann, Ulrich G

2018-01-01

Modern electroceuticals are bound to employ the usage of electrical high frequency (130-180 Hz) stimulation carried out under closed loop control, most prominent in the case of movement disorders. However, particular challenges are faced when electrical recordings of neuronal tissue are carried out during high frequency electrical stimulation, both in-vivo and in-vitro . This stimulation produces undesired artifacts and can render the recorded signal only partially useful. The extent of these artifacts is often reduced by temporarily grounding the recording input during stimulation pulses. In the following study, we quantify the effects of this method, "blanking," on the spike count and spike train statistics. Starting from a theoretical standpoint, we calculate a loss in the absolute number of action potentials, depending on: width of the blanking window, frequency of stimulation, and intrinsic neuronal activity. These calculations were then corroborated by actual high signal to noise ratio (SNR) single cell recordings. We state that, for clinically relevant frequencies of 130 Hz (used for movement disorders) and realistic blanking windows of 2 ms, up to 27% of actual existing spikes are lost. We strongly advice cautioned use of the blanking method when spike rate quantification is attempted. Blanking (artifact removal by temporarily grounding input), depending on recording parameters, can lead to significant spike loss. Very careful use of blanking circuits is advised.

When the Ostrich-Algorithm Fails: Blanking Method Affects Spike Train Statistics

PubMed Central

Joseph, Kevin; Mottaghi, Soheil; Christ, Olaf; Feuerstein, Thomas J.; Hofmann, Ulrich G.

2018-01-01

Modern electroceuticals are bound to employ the usage of electrical high frequency (130–180 Hz) stimulation carried out under closed loop control, most prominent in the case of movement disorders. However, particular challenges are faced when electrical recordings of neuronal tissue are carried out during high frequency electrical stimulation, both in-vivo and in-vitro. This stimulation produces undesired artifacts and can render the recorded signal only partially useful. The extent of these artifacts is often reduced by temporarily grounding the recording input during stimulation pulses. In the following study, we quantify the effects of this method, “blanking,” on the spike count and spike train statistics. Starting from a theoretical standpoint, we calculate a loss in the absolute number of action potentials, depending on: width of the blanking window, frequency of stimulation, and intrinsic neuronal activity. These calculations were then corroborated by actual high signal to noise ratio (SNR) single cell recordings. We state that, for clinically relevant frequencies of 130 Hz (used for movement disorders) and realistic blanking windows of 2 ms, up to 27% of actual existing spikes are lost. We strongly advice cautioned use of the blanking method when spike rate quantification is attempted. Impact statement Blanking (artifact removal by temporarily grounding input), depending on recording parameters, can lead to significant spike loss. Very careful use of blanking circuits is advised. PMID:29780301

Catastrophic cooling and cessation of heating in the solar corona

NASA Astrophysics Data System (ADS)

Peter, H.; Bingert, S.; Kamio, S.

2012-01-01

Context. Condensations in the more than 106 K hot corona of the Sun are commonly observed in the extreme ultraviolet (EUV). While their contribution to the total solar EUV radiation is still a matter of debate, these condensations certainly provide a valuable tool for studying the dynamic response of the corona to the heating processes. Aims: We investigate different distributions of energy input in time and space to investigate which process is most relevant for understanding these coronal condensations. Methods: For a comparison to observations we synthesize EUV emission from a time-dependent, one-dimensional model for coronal loops, where we employ two heating scenarios: simply shutting down the heating and a model where the heating is very concentrated at the loop footpoints, while keeping the total heat input constant. Results: The heating off/on model does not lead to significant EUV count rates that one observes with SDO/AIA. In contrast, the concentration of the heating near the footpoints leads to thermal non-equilibrium near the loop top resulting in the well-known catastrophic cooling. This process gives a good match to observations of coronal condensations. Conclusions: This shows that the corona needs a steady supply of energy to support the coronal plasma, even during coronal condensations. Otherwise the corona would drain very fast, too fast to even form a condensation. Movies are available in electronic form at http://www.aanda.org

Man-Portable Simultaneous Magnetometer and EM System (MSEMS)

DTIC Science & Technology

2008-12-01

expensive fluxgate magnetometers . This is because the interleaving hardware is expecting a Larmor signal as input; it performs period counting of the...Larmor signal between EM61 pulses to convert the frequency-based Larmor signal into nanotesla. A fluxgate magnetometer does not employ the resonance...FINAL REPORT Man-Portable Simultaneous Magnetometer and EM System (MSEMS) ESTCP Project MM-0414 December 2008 Robert Siegel Science

Error Tolerant Plan Recognition: An Empirical Investigation

DTIC Science & Technology

2015-05-01

structure can differ drastically in semantics. For instance, a plan to travel to a grocery store to buy milk might coincidentally be structurally...algorithm for its ability to tolerate input errors, and that storing and leveraging state information in its plan representation substantially...proposed a novel representation for storing and organizing plans in a plan library, based on action-state pairs and abstract states. It counts the

Advanced Integrated Display System V/STOL Program Performance Specification. Volume I.

DTIC Science & Technology

1980-06-01

sensor inputs required before the sensor can be designated acceptable. The reactivation count of each sensor parameter which satisfies its veri...129 3.5.2 AIDS Configuration Parameters .............. 133 3.5.3 AIDS Throughput Requirements ............... 133 4 QUALITY ASSURANCE...lists the adaptation parameters of the AIDS software; these parameters include the throughput and memory requirements of the software. 3.2 SYSTEM

PULSE HEIGHT ANALYZER

DOEpatents

Johnstone, C.W.

1958-01-21

An anticoincidence device is described for a pair of adjacent channels of a multi-channel pulse height analyzer for preventing the lower channel from generating a count pulse in response to an input pulse when the input pulse has sufficient magnitude to reach the upper level channel. The anticoincidence circuit comprises a window amplifier, upper and lower level discriminators, and a biased-off amplifier. The output of the window amplifier is coupled to the inputs of the discriminators, the output of the upper level discriminator is connected to the resistance end of a series R-C network, the output of the lower level discriminator is coupled to the capacitance end of the R-C network, and the grid of the biased-off amplifier is coupled to the junction of the R-C network. In operation each discriminator produces a negative pulse output when the input pulse traverses its voltage setting. As a result of the connections to the R-C network, a trigger pulse will be sent to the biased-off amplifier when the incoming pulse level is sufficient to trigger only the lower level discriminator.

Design and development of cell queuing, processing, and scheduling modules for the iPOINT input-buffered ATM testbed

NASA Astrophysics Data System (ADS)

Duan, Haoran

1997-12-01

This dissertation presents the concepts, principles, performance, and implementation of input queuing and cell-scheduling modules for the Illinois Pulsar-based Optical INTerconnect (iPOINT) input-buffered Asynchronous Transfer Mode (ATM) testbed. Input queuing (IQ) ATM switches are well suited to meet the requirements of current and future ultra-broadband ATM networks. The IQ structure imposes minimum memory bandwidth requirements for cell buffering, tolerates bursty traffic, and utilizes memory efficiently for multicast traffic. The lack of efficient cell queuing and scheduling solutions has been a major barrier to build high-performance, scalable IQ-based ATM switches. This dissertation proposes a new Three-Dimensional Queue (3DQ) and a novel Matrix Unit Cell Scheduler (MUCS) to remove this barrier. 3DQ uses a linked-list architecture based on Synchronous Random Access Memory (SRAM) to combine the individual advantages of per-virtual-circuit (per-VC) queuing, priority queuing, and N-destination queuing. It avoids Head of Line (HOL) blocking and provides per-VC Quality of Service (QoS) enforcement mechanisms. Computer simulation results verify the QoS capabilities of 3DQ. For multicast traffic, 3DQ provides efficient usage of cell buffering memory by storing multicast cells only once. Further, the multicast mechanism of 3DQ prevents a congested destination port from blocking other less- loaded ports. The 3DQ principle has been prototyped in the Illinois Input Queue (iiQueue) module. Using Field Programmable Gate Array (FPGA) devices, SRAM modules, and integrated on a Printed Circuit Board (PCB), iiQueue can process incoming traffic at 800 Mb/s. Using faster circuit technology, the same design is expected to operate at the OC-48 rate (2.5 Gb/s). MUCS resolves the output contention by evaluating the weight index of each candidate and selecting the heaviest. It achieves near-optimal scheduling and has a very short response time. The algorithm originates from a heuristic strategy that leads to 'socially optimal' solutions, yielding a maximum number of contention-free cells being scheduled. A novel mixed digital-analog circuit has been designed to implement the MUCS core functionality. The MUCS circuit maps the cell scheduling computation to the capacitor charging and discharging procedures that are conducted fully in parallel. The design has a uniform circuit structure, low interconnect counts, and low chip I/O counts. Using 2 μm CMOS technology, the design operates on a 100 MHz clock and finds a near-optimal solution within a linear processing time. The circuit has been verified at the transistor level by HSPICE simulation. During this research, a five-port IQ-based optoelectronic iPOINT ATM switch has been developed and demonstrated. It has been fully functional with an aggregate throughput of 800 Mb/s. The second-generation IQ-based switch is currently under development. Equipped with iiQueue modules and MUCS module, the new switch system will deliver a multi-gigabit aggregate throughput, eliminate HOL blocking, provide per-VC QoS, and achieve near-100% link bandwidth utilization. Complete documentation of input modules and trunk module for the existing testbed, and complete documentation of 3DQ, iiQueue, and MUCS for the second-generation testbed are given in this dissertation.

Real-Time Microfluidic Blood-Counting System for PET and SPECT Preclinical Pharmacokinetic Studies.

PubMed

Convert, Laurence; Lebel, Réjean; Gascon, Suzanne; Fontaine, Réjean; Pratte, Jean-François; Charette, Paul; Aimez, Vincent; Lecomte, Roger

2016-09-01

Small-animal nuclear imaging modalities have become essential tools in the development process of new drugs, diagnostic procedures, and therapies. Quantification of metabolic or physiologic parameters is based on pharmacokinetic modeling of radiotracer biodistribution, which requires the blood input function in addition to tissue images. Such measurements are challenging in small animals because of their small blood volume. In this work, we propose a microfluidic counting system to monitor rodent blood radioactivity in real time, with high efficiency and small detection volume (∼1 μL). A microfluidic channel is built directly above unpackaged p-i-n photodiodes to detect β-particles with maximum efficiency. The device is embedded in a compact system comprising dedicated electronics, shielding, and pumping unit controlled by custom firmware to enable measurements next to small-animal scanners. Data corrections required to use the input function in pharmacokinetic models were established using calibrated solutions of the most common PET and SPECT radiotracers. Sensitivity, dead time, propagation delay, dispersion, background sensitivity, and the effect of sample temperature were characterized. The system was tested for pharmacokinetic studies in mice by quantifying myocardial perfusion and oxygen consumption with (11)C-acetate (PET) and by measuring the arterial input function using (99m)TcO4 (-) (SPECT). Sensitivity for PET isotopes reached 20%-47%, a 2- to 10-fold improvement relative to conventional catheter-based geometries. Furthermore, the system detected (99m)Tc-based SPECT tracers with an efficiency of 4%, an outcome not possible through a catheter. Correction for dead time was found to be unnecessary for small-animal experiments, whereas propagation delay and dispersion within the microfluidic channel were accurately corrected. Background activity and sample temperature were shown to have no influence on measurements. Finally, the system was successfully used in animal studies. A fully operational microfluidic blood-counting system for preclinical pharmacokinetic studies was developed. Microfluidics enabled reliable and high-efficiency measurement of the blood concentration of most common PET and SPECT radiotracers with high temporal resolution in small blood volume. © 2016 by the Society of Nuclear Medicine and Molecular Imaging, Inc.

Final Technical Report- Radiation Hard Tight Pitch GaInP SPAD Arrays for High Energy Physics

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

Harmon, Eric S.

The specialized photodetectors used in high energy physics experiments often need to remain extremely sensitive for years despite radiation induced damage caused by the constant bombardment of high energy particles. To solve this problem, LightSpin Technologies, Inc. in collaboration with Prof. Bradley Cox and the University of Virginia is developing radiation-hard GaInP photodetectors which are projected to be extraordinarily radiation hard, theoretically capable of withstanding a 100,000-fold higher radiation dose than silicon. In this Phase I SBIR project, LightSpin investigated the performance and radiation hardness of fifth generation GaInP SPAD arrays. These fifth generation devices used a new planar processingmore » approach that enables very tight pitch arrays to be produced. High performance devices with SPAD pitches of 11, 15, and 25 μm were successfully demonstrated, which greatly increased the dynamic range and maximum count rate of the devices. High maximum count rates are critical when considering radiation hardness, since radiation damage causes a proportional increase in the dark count rate, causing SPAD arrays with low maximum count rates (large SPAD pitches) to fail. These GaInP SPAD array Photomultiplier Chips™ were irradiated with protons, electrons, and neutrons. Initial irradiation results were disappointing, with the post-irradiation devices exhibiting excessively high dark currents. The degradation was traced to surface leakage currents that were largely eliminated through the use of trenches etched around the exterior of the Photomultiplier Chip™ (not between SPAD elements). A second round of irradiations on Photomultiplier Chips™ with trenches proved substantially more successful, with post-irradiation dark currents remaining relatively low, though dark count rates were observed to increase at the highest doses. Preliminary analysis of the post-irradiation devices is promising … many of the irradiated Photomultiplier Chips™ still exhibit good gain characteristics after 1E12/cm 2 – 1E13/cm 2 doses and have apparent dark count rates that are lower than the apparent dark count rates published for irradiation of silicon SPAD arrays (silicon photomultipliers or SiPMs). Some post-irradiation results are still pending because the samples will still too radioactive to be shipped back from the irradiation facility for post-irradiation testing.« less

Impaired hippocampal rate coding after lesions of the lateral entorhinal cortex.

PubMed

Lu, Li; Leutgeb, Jill K; Tsao, Albert; Henriksen, Espen J; Leutgeb, Stefan; Barnes, Carol A; Witter, Menno P; Moser, May-Britt; Moser, Edvard I

2013-08-01

In the hippocampus, spatial and non-spatial parameters may be represented by a dual coding scheme, in which coordinates in space are expressed by the collective firing locations of place cells and the diversity of experience at these locations is encoded by orthogonal variations in firing rates. Although the spatial signal may reflect input from medial entorhinal cortex, the sources of the variations in firing rate have not been identified. We found that rate variations in rat CA3 place cells depended on inputs from the lateral entorhinal cortex (LEC). Hippocampal rate remapping, induced by changing the shape or the color configuration of the environment, was impaired by lesions in those parts of the ipsilateral LEC that provided the densest input to the hippocampal recording position. Rate remapping was not observed in LEC itself. The findings suggest that LEC inputs are important for efficient rate coding in the hippocampus.

Variability, drivers, and effects of atmospheric nitrogen inputs across an urban area: Emerging patterns among human activities, the atmosphere, and soils.

PubMed

Decina, Stephen M; Templer, Pamela H; Hutyra, Lucy R; Gately, Conor K; Rao, Preeti

2017-12-31

Atmospheric deposition of nitrogen (N) is a major input of N to the biosphere and is elevated beyond preindustrial levels throughout many ecosystems. Deposition monitoring networks in the United States generally avoid urban areas in order to capture regional patterns of N deposition, and studies measuring N deposition in cities usually include only one or two urban sites in an urban-rural comparison or as an anchor along an urban-to-rural gradient. Describing patterns and drivers of atmospheric N inputs is crucial for understanding the effects of N deposition; however, little is known about the variability and drivers of atmospheric N inputs or their effects on soil biogeochemistry within urban ecosystems. We measured rates of canopy throughfall N as a measure of atmospheric N inputs, as well as soil net N mineralization and nitrification, soil solution N, and soil respiration at 15 sites across the greater Boston, Massachusetts area. Rates of throughfall N are 8.70±0.68kgNha -1 yr -1 , vary 3.5-fold across sites, and are positively correlated with rates of local vehicle N emissions. Ammonium (NH 4 + ) composes 69.9±2.2% of inorganic throughfall N inputs and is highest in late spring, suggesting a contribution from local fertilizer inputs. Soil solution NO 3 - is positively correlated with throughfall NO 3 - inputs. In contrast, soil solution NH 4 + , net N mineralization, nitrification, and soil respiration are not correlated with rates of throughfall N inputs. Rather, these processes are correlated with soil properties such as soil organic matter. Our results demonstrate high variability in rates of urban throughfall N inputs, correlation of throughfall N inputs with local vehicle N emissions, and a decoupling of urban soil biogeochemistry and throughfall N inputs. Copyright © 2017 Elsevier B.V. All rights reserved.

Experimental evaluation of the extended Dytlewski-style dead time correction formalism for neutron multiplicity counting

NASA Astrophysics Data System (ADS)

Lockhart, M.; Henzlova, D.; Croft, S.; Cutler, T.; Favalli, A.; McGahee, Ch.; Parker, R.

2018-01-01

Over the past few decades, neutron multiplicity counting has played an integral role in Special Nuclear Material (SNM) characterization pertaining to nuclear safeguards. Current neutron multiplicity analysis techniques use singles, doubles, and triples count rates because a methodology to extract and dead time correct higher order count rates (i.e. quads and pents) was not fully developed. This limitation is overcome by the recent extension of a popular dead time correction method developed by Dytlewski. This extended dead time correction algorithm, named Dytlewski-Croft-Favalli(DCF), is detailed in reference Croft and Favalli (2017), which gives an extensive explanation of the theory and implications of this new development. Dead time corrected results can then be used to assay SNM by inverting a set of extended point model equations which as well have only recently been formulated. The current paper discusses and presents the experimental evaluation of practical feasibility of the DCF dead time correction algorithm to demonstrate its performance and applicability in nuclear safeguards applications. In order to test the validity and effectiveness of the dead time correction for quads and pents, 252Cf and SNM sources were measured in high efficiency neutron multiplicity counters at the Los Alamos National Laboratory (LANL) and the count rates were extracted up to the fifth order and corrected for dead time. In order to assess the DCF dead time correction, the corrected data is compared to traditional dead time correction treatment within INCC. The DCF dead time correction is found to provide adequate dead time treatment for broad range of count rates available in practical applications.

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

Fisk, William J.; Sullivan, Douglas

This pilot scale study evaluated the counting accuracy of two people counting systems that could be used in demand controlled ventilation systems to provide control signals for modulating outdoor air ventilation rates. The evaluations included controlled challenges of the people counting systems using pre-planned movements of occupants through doorways and evaluations of counting accuracies when naive occupants (i.e., occupants unaware of the counting systems) passed through the entrance doors of the building or room. The two people counting systems had high counting accuracy accuracies, with errors typically less than 10percent, for typical non-demanding counting events. However, counting errors were highmore » in some highly challenging situations, such as multiple people passing simultaneously through a door. Counting errors, for at least one system, can be very high if people stand in the field of view of the sensor. Both counting system have limitations and would need to be used only at appropriate sites and where the demanding situations that led to counting errors were rare.« less

Exfoliation rate of mammary epithelial cells in milk on bovine mastitis caused by Staphylococcus aureus is associated with bacterial load.

PubMed

Nagasawa, Yuya; Kiku, Yoshio; Sugawara, Kazue; Tanabe, Fuyuko; Hayashi, Tomohito

2018-01-01

The exfoliation rate of mammary epithelial cells (MECs) in milk is affected by physiological, breeding and environmental factors. Little is known about the relationship between the MEC exfoliation into milk and mammary-infected Staphylococcus aureus (S. aureus) load on bovine mastitis caused by S. aureus. The aim of this study was to investigate the relationship between S. aureus load and the proportion of MEC exfoliation in milk using five substantial bovine mastitis models. In 64 randomly extracted milk samples from udders at 3-21 days after S. aureus infusion, there were various samples with different numbers of S. aureus counts and somatic cell counts. No significant correlations were found between the S. aureus counts and somatic cell count (r = 0.338). In contrast, a significant correlation was noted between S. aureus counts and the proportion of cytokeratin-positive cells in the milk from the infused udders (r = 0.734, P < 0.01). In conclusion, the increasing MEC exfoliation rate in milk from mastitis udders caused by S. aureus may contribute to reduced milk yield. © 2017 Japanese Society of Animal Science.

Addressing immunization registry population inflation in adolescent immunization rates.

PubMed

Robison, Steve G

2015-01-01

While U.S. adolescent immunization rates are available annually at national and state levels, finding pockets of need may require county or sub-county information. Immunization information systems (IISs) are one tool for assessing local immunization rates. However, the presence of IIS records dating back to early childhood and challenges in capturing mobility out of IIS areas typically leads to denominator inflation. We examined the feasibility of weighting adolescent immunization records by length of time since last report to produce more accurate county adolescent counts and immunization rates. We compared weighted and unweighted adolescent denominators from the Oregon ALERT IIS, along with county-level Census Bureau estimates, with school enrollment counts from Oregon's annual review of seventh-grade school immunization compliance for public and private schools. Adolescent immunization rates calculated using weighted data, for the state as a whole, were also checked against comparable National Immunization Survey (NIS) rates. Weighting individual records by the length of time since last activity substantially improved the fit of IIS data to county populations for adolescents. A nonlinear logarithmic (ogive) weight produced the best fit to the school count data of all examined estimates. Overall, the ogive weighted results matched NIS adolescent rates for Oregon. The problem of mobility-inflated counts of teenagers can be addressed by weighting individual records based on time since last immunization. Well-populated IISs can rely on their own data to produce adolescent immunization rates and find pockets of need.

Total motile sperm count has a superior predictive value over the WHO 2010 cut-off values for the outcomes of intracytoplasmic sperm injection cycles.

PubMed

Borges, E; Setti, A S; Braga, D P A F; Figueira, R C S; Iaconelli, A

2016-09-01

The objective of this study was to compare (i) the intracytoplasmic sperm injection outcomes among groups with different total motile sperm count ranges, (ii) the intracytoplasmic sperm injection outcomes between groups with normal and abnormal total motile sperm count, and (iii) the predictive values of WHO 2010 cut-off values and pre-wash total motile sperm count for the intracytoplasmic sperm injection outcomes, in couples with male infertility. This study included data from 518 patients undergoing their first intracytoplasmic sperm injection cycle as a result of male infertility. Couples were divided into five groups according to their total motile sperm count: Group I, total motile sperm count <1 × 10(6) ; group II, total motile sperm count 1-5 × 10(6) ; group III, total motile sperm count 5-10 × 10(6) ; group IV, total motile sperm count 10-20 × 10(6) ; and group V, total motile sperm count >20 × 10(6) (which was considered a normal total motile sperm count value). Then, couples were grouped into an abnormal and normal total motile sperm count group. The groups were compared regarding intracytoplasmic sperm injection outcomes. The predictive values of WHO 2010 cut-off values and total motile sperm count for the intracytoplasmic sperm injection outcomes were also investigated. The fertilization rate was lower in total motile sperm count group I compared to total motile sperm count group V (72.5 ± 17.6 vs. 84.9 ± 14.4, p = 0.011). The normal total motile sperm count group had a higher fertilization rate (84.9 ± 14.4 vs. 81.1 ± 15.8, p = 0.016) and lower miscarriage rate (17.9% vs. 29.5%, p = 0.041) compared to the abnormal total motile sperm count group. The total motile sperm count was the only parameter that demonstrated a predictive value for the formation of high-quality embryos on D2 (OR: 1.18, p = 0.013), formation of high-quality embryos on D3 (OR: 1.12, p = 0.037), formation of blastocysts on D5 (OR: 1.16, p = 0.011), blastocyst expansion grade on D5 (OR: 1.27, p = 0.042), and the odds of miscarriage (OR: 0.52, p < 0.045). The total motile sperm count has a greater predictive value than the WHO 2010 cut-off values for laboratory results and pregnancy outcomes in couples undergoing intracytoplasmic sperm injection as a result of male infertility. © 2016 American Society of Andrology and European Academy of Andrology.

Making Hawai'i's Kids Count. Issue Paper Number 3.

ERIC Educational Resources Information Center

Hawaii Univ., Manoa. Center on the Family.

This issue paper from Hawai'i Kids Count addresses the issue of teen pregnancy and birth rates. The paper notes that teen pregnancy and birth rates are declining both nationally and in Hawaii and describes key risk factors associated with having a baby before age 20: (1) early school failure; (2) early behavioral problems; (3) family dysfunction;…

Arkansas Kids Count Data Book 1995: A Portrait of Arkansas' Children.

ERIC Educational Resources Information Center

Arkansas Advocates for Children and Families, Little Rock.

This Kids Count report is the third to examine the well-being of Arkansas' children and the first to provide trend information. The statistical report is based on 10 core indicators of well-being: (1) unemployment rate and per capita personal income; (2) federal and state assistance program participation rates; (3) percent of high school students…

Pneumocystis jirovecii colonisation in HIV-positive and HIV-negative subjects in Cameroon.

PubMed

Riebold, D; Enoh, D O; Kinge, T N; Akam, W; Bumah, M K; Russow, K; Klammt, S; Loebermann, M; Fritzsche, C; Eyong, J E; Eppel, G; Kundt, G; Hemmer, C J; Reisinger, E C

2014-06-01

To determine the prevalence of Pneumocystis pneumonia (PCP), a major opportunistic infection in AIDS patients in Europe and the USA, in Cameroon. Induced sputum samples from 237 patients without pulmonary symptoms (126 HIV-positive and 111 HIV-negative outpatients) treated at a regional hospital in Cameroon were examined for the prevalence of Pneumocystis jirovecii by specific nested polymerase chain reaction (nPCR) and staining methods. CD 4 counts and the history of antiretroviral therapy of the subjects were obtained through the ESOPE database system. Seventy-five of 237 study participants (31.6%) were colonised with Pneumocystis, but none showed active PCP. The Pneumocystis colonisation rate in HIV-positive subjects was more than double that of HIV-negative subjects (42.9% vs. 18.9%, P < 0.001). In the HIV-positive group, the colonisation rate corresponds to the reduction in the CD 4 lymphocyte counts. Subjects with CD 4 counts >500 cells/μl were colonised at a rate of 20.0%, subjects with CD 4 counts between 200 and 500 cells/μl of 42.5%, and subjects with CD 4 counts <200 cells/μl of 57.1%. Colonisation with Pneumocystis in Cameroon seems to be comparable to rates found in Western Europe. Prophylactic and therapeutic measures against Pneumocystis should be taken into account in HIV care in western Africa. © 2014 John Wiley & Sons Ltd.

Differential Die-Away Instrument: Report on Neutron Detector Recovery Performance and Proposed Improvements

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

Goodsell, Alison Victoria; Swinhoe, Martyn Thomas; Henzl, Vladimir

2014-09-22

Four helium-3 ( 3He) detector/preamplifier packages (¾”/KM200, DDSI/PDT-A111, DDA/PDT-A111, and DDA/PDT10A) were experimentally tested to determine the deadtime effects at different DT neutron generator output settings. At very high count rates, the ¾”/KM200 package performed best. At high count rates, the ¾”/KM200 and the DDSI/PDT-A111 packages performed very well, with the DDSI/PDT-A111 operating with slightly higher efficiency. All of the packages performed similarly at mid to low count rates. Proposed improvements include using a fast recovery LANL-made dual channel preamplifier, testing smaller diameter 3He tubes, and further investigating quench gases.

Clustering method for counting passengers getting in a bus with single camera

NASA Astrophysics Data System (ADS)

Yang, Tao; Zhang, Yanning; Shao, Dapei; Li, Ying

2010-03-01

Automatic counting of passengers is very important for both business and security applications. We present a single-camera-based vision system that is able to count passengers in a highly crowded situation at the entrance of a traffic bus. The unique characteristics of the proposed system include, First, a novel feature-point-tracking- and online clustering-based passenger counting framework, which performs much better than those of background-modeling-and foreground-blob-tracking-based methods. Second, a simple and highly accurate clustering algorithm is developed that projects the high-dimensional feature point trajectories into a 2-D feature space by their appearance and disappearance times and counts the number of people through online clustering. Finally, all test video sequences in the experiment are captured from a real traffic bus in Shanghai, China. The results show that the system can process two 320×240 video sequences at a frame rate of 25 fps simultaneously, and can count passengers reliably in various difficult scenarios with complex interaction and occlusion among people. The method achieves high accuracy rates up to 96.5%.

Single photon detection in a waveguide-coupled Ge-on-Si lateral avalanche photodiode.

PubMed

Martinez, Nicholas J D; Gehl, Michael; Derose, Christopher T; Starbuck, Andrew L; Pomerene, Andrew T; Lentine, Anthony L; Trotter, Douglas C; Davids, Paul S

2017-07-10

We examine gated-Geiger mode operation of an integrated waveguide-coupled Ge-on-Si lateral avalanche photodiode (APD) and demonstrate single photon detection at low dark count for this mode of operation. Our integrated waveguide-coupled APD is fabricated using a selective epitaxial Ge-on-Si growth process resulting in a separate absorption and charge multiplication (SACM) design compatible with our silicon photonics platform. Single photon detection efficiency and dark count rate is measured as a function of temperature in order to understand and optimize performance characteristics in this device. We report single photon detection of 5.27% at 1310 nm and a dark count rate of 534 kHz at 80 K for a Ge-on-Si single photon avalanche diode. Dark count rate is the lowest for a Ge-on-Si single photon detector in this range of temperatures while maintaining competitive detection efficiency. A jitter of 105 ps was measured for this device.

Regional Hospital Input Price Indexes

PubMed Central

Freeland, Mark S.; Schendler, Carol Ellen; Anderson, Gerard

1981-01-01

This paper describes the development of regional hospital input price indexes that is consistent with the general methodology used for the National Hospital Input Price Index. The feasibility of developing regional indexes was investigated because individuals inquired whether different regions experienced different rates of increase in hospital input prices. The regional indexes incorporate variations in cost-share weights (the amount an expense category contributes to total spending) associated with hospital type and location, and variations in the rate of input price increases for various regions. We found that between 1972 and 1979 none of the regional price indexes increased at average annual rates significantly different from the national rate. For the more recent period 1977 through 1979, the increase in one Census Region was significantly below the national rate. Further analyses indicated that variations in cost-share weights for various types of hospitals produced no substantial variations in the regional price indexes relative to the national index. We consider these findings preliminary because of limitations in the availability of current, relevant, and reliable data, especially for local area wage rate increases. PMID:10309557

47 CFR 2.1049 - Measurements required: Occupied bandwidth.

Code of Federal Regulations, 2012 CFR

2012-10-01

... monaural operation—when amplitude modulated 85% by a 7,500 Hz input signal. (2) AM broadcast stereophonic... broadcast stereophonic sound transmitters—when the transmitter is modulated with a 15 kHz input signal to... input signal such that its amplitude and symbol rate represent the maximum rated conditions under which...

47 CFR 2.1049 - Measurements required: Occupied bandwidth.

Code of Federal Regulations, 2011 CFR

2011-10-01

... monaural operation—when amplitude modulated 85% by a 7,500 Hz input signal. (2) AM broadcast stereophonic... broadcast stereophonic sound transmitters—when the transmitter is modulated with a 15 kHz input signal to... input signal such that its amplitude and symbol rate represent the maximum rated conditions under which...

47 CFR 2.1049 - Measurements required: Occupied bandwidth.

Code of Federal Regulations, 2013 CFR

2013-10-01

... monaural operation—when amplitude modulated 85% by a 7,500 Hz input signal. (2) AM broadcast stereophonic... broadcast stereophonic sound transmitters—when the transmitter is modulated with a 15 kHz input signal to... input signal such that its amplitude and symbol rate represent the maximum rated conditions under which...

47 CFR 2.1049 - Measurements required: Occupied bandwidth.

Code of Federal Regulations, 2014 CFR

2014-10-01

... monaural operation—when amplitude modulated 85% by a 7,500 Hz input signal. (2) AM broadcast stereophonic... broadcast stereophonic sound transmitters—when the transmitter is modulated with a 15 kHz input signal to... input signal such that its amplitude and symbol rate represent the maximum rated conditions under which...

[Clinical randomized controlled trial on the feasibility and validity of continuous blood purification during the early stage of severe burn].

PubMed

Liu, F; Huang, Z G; Peng, Y Z; Wu, J; He, W F; Yuan, Z Q; Zhang, J P; Luo, Q Z; Yan, H; Peng, D Z; Dang, Y M; Luo, G X

2016-03-01

To observe and primarily evaluate the feasibility and validity of continuous blood purification (CBP) during the early stage of severe burn. Forty-one patients with severe burn admitted to our ward from January 2013 to July 2015, conforming to the study criteria, were divided into conventional treatment group (CT, n=21) and blood purification group (BP, n=20) according to the random number table and patient's personal consent. Patients in group CT received CT conforming to the traditional resuscitation principle for severe burn, while patients in group BP received CT and blood purification treatment in the mode of continuous venous-venous hemodiafiltration in addition up to post injury hour (PIH) 72. On post injury day (PID) 1, 2, 3, the vital signs, volume of fluid input, and volume of the urine output were observed and recorded; femoral artery blood was drawn to determine lactate, bicarbonate radical, and base excess, and oxygen index was calculated. At PIH 12, 24, 48, 72, femoral vein blood was drawn to determine white cell count, platelet count, neutrophils, creatine kinase-MB, creatine kinase, lactic dehydrogenase, aspartate transaminase (AST), alanine aminotransferase (ALT), creatinine, urea nitrogen, and blood glucose (the ratio of AST to ALT was calculated). The incidence of infection, sepsis, and multiple organ dysfunction syndrome (MODS) and the mortality of patients were recorded during 2 months after injury. Data were processed with chi-square test, analysis of variance for repeated measurement, t test and Wilcoxon test, and the values of P were adjusted by Bonferroni. The observation was completed in the 41 patients without exclusion. (1) There were no statistically significant differences in vital signs, volume of fluid input, and volume of the urine output of patients between two groups on PID 1, 2, 3 (with t values from -1.64 to 1.48, P values above 0.05). (2) Compared with that in group CT, the level of lactate of patients in group BP declined significantly on PID 2 and 3 (with Z values respectively -2.37 and -2.46, P values below 0.05). Compared with those in group CT, the levels of bicarbonate radical and base excess of patients in group BP declined significantly on PID 3 (with t values both as -2.51, P values below 0.05). The oxygen index of patients in group BP on PID 3 was (370±98) mmHg (1 mmHg=0.133 kPa), which was significantly higher than that in group CT [(305±81) mmHg, t=2.27, P<0.05]. (3) There were no statistically significant differences in white cell count, platelet count, neutrophils, creatine kinase, lactic dehydrogenase, AST, ALT, and AST to ALT ratio of patients between two groups at PIH 12, 24, 48, 72 (with t values from -1.47 to 1.19, Z values from -1.58 to -0.03, P values above 0.05). At PIH 24, 48, 72, the levels of creatine kinase-MB and blood glucose of patients in group BP were respectively (81±43), (55±34), (58±40) U/L and (7.9±2.0), (6.7±0.9), (6.9±1.8) mmol/L, which were significantly lower than those in group CT [(179±184), (124±71), (103±57) U/L and (10.1±3.8), (9.1±2.4), (8.8±4.1) mmol/L, with Z values from -3.73 to -2.02, P<0.05 or P<0.01]. Compared with those of patients in group CT, creatinine at PIH 48 and urea nitrogen at PIH 24, 48, 72 were obviously lower in group BP (with t values from -4.23 to -2.44, P<0.05 or P<0.01). (4) During the two months after injury, the infection rate of patients in group BP was 60.0% (12/20), which was significantly lower than that in group CT [95.2% (20/21), χ(2)=5.51, P<0.05]. The incidence of sepsis and MODS and the mortality of patients in group BP were all lower than those in group CT, but there were no statistically significant differences (with χ(2) values from 0.22 to 2.93, P values above 0.05). Conducting CBP in the early stage of severe burn is safe and feasible, which does not obviously affect the vital signs, volumes of fluid input and urine output, or platelet count of patients, additionally, it could help protect the function of vital organs, eliminate stress hyperglycemia, and reduce infection rate. Clinical trial registration Chinese Clinical Trial Registry, ChiCTR-TRC-12002616.

Digital scale converter

DOEpatents

Upton, Richard G.

1978-01-01

A digital scale converter is provided for binary coded decimal (BCD) conversion. The converter may be programmed to convert a BCD value of a first scale to the equivalent value of a second scale according to a known ratio. The value to be converted is loaded into a first BCD counter and counted down to zero while a second BCD counter registers counts from zero or an offset value depending upon the conversion. Programmable rate multipliers are used to generate pulses at selected rates to the counters for the proper conversion ratio. The value present in the second counter at the time the first counter is counted to the zero count is the equivalent value of the second scale. This value may be read out and displayed on a conventional seven-segment digital display.

Potential of silver nanoparticle-coated polyurethane foam as an antibacterial water filter.

PubMed

Jain, Prashant; Pradeep, T

2005-04-05

Silver nanoparticles can be coated on common polyurethane (PU) foams by overnight exposure of the foams to nanoparticle solutions. Repeated washing and air-drying yields uniformly coated PU foam, which can be used as a drinking water filter where bacterial contamination of the surface water is a health risk. Nanoparticles are stable on the foam and are not washed away by water. Morphology of the foam was retained after coating. The nanoparticle binding is due to its interaction with the nitrogen atom of the PU. Online tests were conducted with a prototypical water filter. At a flow rate of 0.5 L/min, in which contact time was of the order of a second, the output count of Escherichia coli was nil when the input water had a bacterial load of 10(5) colony-forming units (CFU) per mL. Combined with the low cost and effectiveness in its applications, the technology may have large implications to developing countries. Copyright (c) 2005 Wiley Periodicals, Inc.

Prospects for measuring the 229Th isomer energy using a metallic magnetic microcalorimeter.

PubMed

Kazakov, G A; Schauer, V; Schwestka, J; Stellmer, S P; Sterba, J H; Fleischmann, A; Gastaldo, L; Pabinger, A; Enss, C; Schumm, T

2014-01-21

The Thorium-229 isotope features a nuclear isomer state with an extremely low energy. The currently most accepted energy value, 7.8±0.5 eV, was obtained from an indirect measurement using a NASA x-ray microcalorimeter with an instrumental resolution 26 eV. We study, how state-of-the-art magnetic metallic microcalorimeters with an energy resolution down to a few eV can be used to measure the isomer energy. In particular, resolving the 29.18 keV doublet in the γ-spectrum following the α-decay of Uranium-233, corresponding to the decay into the ground and isomer state, allows to measure the isomer transition energy without additional theoretical input parameters, and increase the energy accuracy. We study the possibility of resolving the 29.18 keV line as a doublet and the dependence of the attainable precision of the energy measurement on the signal and background count rates and the instrumental resolution.

Prospects for measuring the 229Th isomer energy using a metallic magnetic microcalorimeter☆

PubMed Central

Kazakov, G.A.; Schauer, V.; Schwestka, J.; Stellmer, S.P.; Sterba, J.H.; Fleischmann, A.; Gastaldo, L.; Pabinger, A.; Enss, C.; Schumm, T.

2014-01-01

The Thorium-229 isotope features a nuclear isomer state with an extremely low energy. The currently most accepted energy value, 7.8±0.5 eV, was obtained from an indirect measurement using a NASA x-ray microcalorimeter with an instrumental resolution 26 eV. We study, how state-of-the-art magnetic metallic microcalorimeters with an energy resolution down to a few eV can be used to measure the isomer energy. In particular, resolving the 29.18 keV doublet in the γ-spectrum following the α-decay of Uranium-233, corresponding to the decay into the ground and isomer state, allows to measure the isomer transition energy without additional theoretical input parameters, and increase the energy accuracy. We study the possibility of resolving the 29.18 keV line as a doublet and the dependence of the attainable precision of the energy measurement on the signal and background count rates and the instrumental resolution. PMID:25844000

Modeling the distribution of illicit oily discharges detected by aerial surveillance in western Canadian marine waters.

PubMed

Serra-Sogas, Norma; O'Hara, Patrick D; Canessa, Rosaline

2014-10-15

Oily discharges from vessel operations have been documented in Canada's Pacific region by the National Aerial Surveillance Program (NASP) since the early 1990s. We explored a number of regression methods to explain the distribution and counts per grid cell of oily discharges detected from 1998 to 2007 using independent predictor variables, while trying to address the large number of zeros present in the data. Best-fit models indicate that discharges are generally concentrated close to shore typically in association with small harbours, and with major commercial and tourist centers. Oily discharges were also concentrated in Barkley Sound and at the entrance of Juan de Fuca Strait. The identification of important factors associated with discharge patterns, and predicting discharge rates in areas with surveillance effort can be used to inform future surveillance. Model output can also be used as inputs for risk models for existing conditions and as baseline for future scenarios. Crown Copyright © 2014. Published by Elsevier Ltd. All rights reserved.

TOFPET 2: A high-performance circuit for PET time-of-flight

NASA Astrophysics Data System (ADS)

Di Francesco, Agostino; Bugalho, Ricardo; Oliveira, Luis; Rivetti, Angelo; Rolo, Manuel; Silva, Jose C.; Varela, Joao

2016-07-01

We present a readout and digitization ASIC featuring low-noise and low-power for time-of flight (TOF) applications using SiPMs. The circuit is designed in standard CMOS 110 nm technology, has 64 independent channels and is optimized for time-of-flight measurement in Positron Emission Tomography (TOF-PET). The input amplifier is a low impedance current conveyor based on a regulated common-gate topology. Each channel has quad-buffered analogue interpolation TDCs (time binning 20 ps) and charge integration ADCs with linear response at full scale (1500 pC). The signal amplitude can also be derived from the measurement of time-over-threshold (ToT). Simulation results show that for a single photo-electron signal with charge 200 (550) fC generated by a SiPM with (320 pF) capacitance the circuit has 24 (30) dB SNR, 75 (39) ps r.m.s. resolution, and 4 (8) mW power consumption. The event rate is 600 kHz per channel, with up to 2 MHz dark counts rejection.

A method to test the performance of an energy-dispersive X-ray spectrometer (EDS).

PubMed

Hodoroaba, Vasile-Dan; Procop, Mathias

2014-10-01

A test material for routine performance evaluation of energy-dispersive X-ray spectrometers (EDS) is presented. It consists of a synthetic, thick coating of C, Al, Mn, Cu, and Zr, in an elemental composition that provides interference-free characteristic X-ray lines of similar intensities at 10 kV scanning electron microscope voltage. The EDS energy resolution at the C-K, Mn-Lα, Cu-Lα, Al-K, Zr-Lα, and Mn-Kα lines, the calibration state of the energy scale, and the Mn-Lα/Mn-Kα intensity ratio as a measure for the low-energy detection efficiency are calculated by a dedicated software package from the 10 kV spectrum. Measurements at various input count rates and processor shaping times enable an estimation of the operation conditions for which the X-ray spectrum is not yet corrupted by pile-up events. Representative examples of EDS systems characterized with the test material and the related software are presented and discussed.

Multichannel analyzers at high rates of input

NASA Technical Reports Server (NTRS)

Rudnick, S. J.; Strauss, M. G.

1969-01-01

Multichannel analyzer, used with a gating system incorporating pole-zero compensation, pile-up rejection, and baseline-restoration, achieves good resolution at high rates of input. It improves resolution, reduces tailing and rate-contributed continuum, and eliminates spectral shift.

Association of Mycoplasma pneumoniae infection with increased risk of asthma in children.

PubMed

Yin, Sha-Sha; Ma, Feng-Lian; Gao, Xing

2017-05-01

The present study was conducted to investigate the relationship between Mycoplasma pneumoniae (MP) infection and the risk of asthma among children by detecting the rate of MP immunoglobulin M (MP-IgM) and the eosinophil (EOS) count. A total of 139 asthmatic children were enrolled as the case group and assigned into three groups: Group A (aged <3 years, n=42), group B (aged 3-8 years, n=45) and group C (aged >8 years, n=52). Additionally, 115 healthy children were enrolled in the control group. Enzyme-linked immunosorbent assay was used to measure the MP-IgM-positive rate. EOS count was detected in the experimental and control groups by using a hemocytometer analyzer. A meta-analysis was performed by using the Comprehensive Meta-Analysis version 2.0 software. The positive rates of the MP-IgM and EOS count in the experimental group were significantly higher than those in control group (both P<0.001). Furthermore, the asthmatic children in group C had a higher MP-IgM-positive rate and EOS count as compared to those in groups A and B, respectively (all P<0.05). Results from groups A and B were not statistically significant (all P>0.05). The meta-analysis further confirmed that asthmatic children had a higher MP-IgM-positive rate as compared to the healthy controls (P<0.001). Age-stratified analysis revealed that the MP-IgM-positive rate in asthmatic children aged ≥8 and <8 years was significantly higher than that in the healthy controls (P=0.003 and P<0.001). Asthmatic children had a higher MP-IgM-positive rate and EOS count as compared with controls, suggesting that the MP infection may be closely associated with the risk of asthma. Additionally, the positive rate of MP-IgM may indicate an important biological marker in predicting the development of asthma.

Population structure, persistence, and seasonality of autochthonous Escherichia coli in temperate, coastal forest soil from a Great Lakes watershed

USGS Publications Warehouse

Byappanahalli, M.N.; Whitman, R.L.; Shively, D.A.; Sadowsky, M.J.; Ishii, S.

2006-01-01

The common occurrence of Escherichia coli in temperate soils has previously been reported, however, there are few studies to date to characterize its source, distribution, persistent capability and genetic diversity. In this study, undisturbed, forest soils within six randomly selected 0.5 m2 exclosure plots (covered by netting of 2.3 mm2 mesh size) were monitored from March to October 2003 for E. coli in order to describe its numerical and population characteristics. Culturable E. coli occurred in 88% of the samples collected, with overall mean counts of 16 MPN g-1, ranging from <1 to 1657 (n = 66). Escherichia coli counts did not correlate with substrate moisture content, air, or soil temperatures, suggesting that seasonality were not a strong factor in population density control. Mean E. coli counts in soil samples (n = 60) were significantly higher inside than immediately outside the exclosures; E. coli distribution within the exclosures was patchy. Repetitive extragenic palindromic polymerase chain reaction (Rep-PCR) demonstrated genetic heterogeneity of E. coli within and among exclosure sites, and the soil strains were genetically distinct from animal (E. coli) strains tested (i.e. gulls, terns, deer and most geese). These results suggest that E. coli can occur and persist for extended periods in undisturbed temperate forest soils independent of recent allochthonous input and season, and that the soil E. coli populations formed a cohesive phylogenetic group in comparison to the set of fecal strains with which they were compared. Thus, in assessing E. coli sources within a stream, it is important to differentiate background soil loadings from inputs derived from animal and human fecal contamination. ?? 2005 Society for Applied Microbiology and Blackwell Publishing Ltd.

Effects of Point Count Duration, Time-of-Day, and Aural Stimuli on Detectability of Migratory and Resident Bird Species in Quintana Roo, Mexico

Treesearch

James F. Lynch

1995-01-01

Effects of count duration, time-of-day, and aural stimuli were studied in a series of unlimited-radius point counts conducted during winter in Quintana Roo, Mexico. The rate at which new species were detected was approximately three times higher during the first 5 minutes of each 15- minute count than in the final 5 minutes. The number of individuals and species...

Fluorescence decay data analysis correcting for detector pulse pile-up at very high count rates

NASA Astrophysics Data System (ADS)

Patting, Matthias; Reisch, Paja; Sackrow, Marcus; Dowler, Rhys; Koenig, Marcelle; Wahl, Michael

2018-03-01

Using time-correlated single photon counting for the purpose of fluorescence lifetime measurements is usually limited in speed due to pile-up. With modern instrumentation, this limitation can be lifted significantly, but some artifacts due to frequent merging of closely spaced detector pulses (detector pulse pile-up) remain an issue to be addressed. We propose a data analysis method correcting for this type of artifact and the resulting systematic errors. It physically models the photon losses due to detector pulse pile-up and incorporates the loss in the decay fit model employed to obtain fluorescence lifetimes and relative amplitudes of the decay components. Comparison of results with and without this correction shows a significant reduction of systematic errors at count rates approaching the excitation rate. This allows quantitatively accurate fluorescence lifetime imaging at very high frame rates.

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

Church, J; Slaughter, D; Norman, E

Error rates in a cargo screening system such as the Nuclear Car Wash [1-7] depend on the standard deviation of the background radiation count rate. Because the Nuclear Car Wash is an active interrogation technique, the radiation signal for fissile material must be detected above a background count rate consisting of cosmic, ambient, and neutron-activated radiations. It was suggested previously [1,6] that the Corresponding negative repercussions for the sensitivity of the system were shown. Therefore, to assure the most accurate estimation of the variation, experiments have been performed to quantify components of the actual variance in the background count rate,more » including variations in generator power, irradiation time, and container contents. The background variance is determined by these experiments to be a factor of 2 smaller than values assumed in previous analyses, resulting in substantially improved projections of system performance for the Nuclear Car Wash.« less

[Health management system in outpatient follow-up of kidney transplantation patients].

PubMed

Zhang, Hong; Xie, Jinliang; Yao, Hui; Liu, Ling; Tan, Jianwen; Geng, Chunmi

2014-07-01

To develop a health management system for outpatient follow-up of kidney transplant patients. Access 2010 database software was used to establish the health management system for kidney transplantation patients in Windows XP operating system. Database management and post-operation follow-up of the kidney transplantation patients were realized through 6 function modules including data input, data query, data printing, questionnaire survey, data export, and follow-up management. The system worked stably and reliably, and the data input was easy and fast. The query, the counting and printing were convenient. Health management system for patients after kidney transplantation not only reduces the work pressure of the follow-up staff, but also improves the efficiency of outpatient follow-up.

Dynamic Testing and Automatic Repair of Reconfigurable Wiring Harnesses

DTIC Science & Technology

2006-11-27

Switch An M ×N grid of switches configured to provide a M -input, N -output routing network. Permutation Network A permutation network performs an...wiring reduces the effective advantage of their reduced switch count, particularly when considering that regular grids (crossbar switches being a...are connected to. The outline circuit shown in Fig. 20 shows how a suitable ‘discovery probe’ might be implemented. The circuit shows a UART

Community-Based Decision-Making: Application of Web ...

EPA Pesticide Factsheets

Living, working, and going to school near roadways has been associated with a number of adverse health effects, including asthma exacerbation, cardiovascular impairment, and respiratory symptoms. In the United States, 30% - 45% of urban populations live or work in the near-road environment, with a greater percentage of minority and low-income residents living in areas with highly- trafficked roadways. Near-road studies typically use surrogates of exposure to evaluate potential causality of health effects, including proximity, traffic counts, or total length of roads within a given radius. In contrast, simplified models provide an opportunity to examine how changes in input parameters, such as vehicle counts or speeds, can affect air quality. Simplified or reduced-form models typically retain the same or similar algorithms most responsible for characterizing uncertainty in more sophisticated models. The Community Line Source modeling system (C-LINE) allows users to explore what-if scenarios such as increases in diesel trucks or total traffic; examine hot spot conditions and areas for further study; determine ideal monitor placement locations; or evaluate air quality changes due to traffic re-routing. This presentation describes the input parameters, analytical procedures, visualization routines, and software considerations for C-LINE, and an example application for Newport News, Virginia. Results include scenarios related to port development and resulting traffic

A novel method for flow pattern identification in unstable operational conditions using gamma ray and radial basis function.

PubMed

Roshani, G H; Nazemi, E; Roshani, M M

2017-05-01

Changes of fluid properties (especially density) strongly affect the performance of radiation-based multiphase flow meter and could cause error in recognizing the flow pattern and determining void fraction. In this work, we proposed a methodology based on combination of multi-beam gamma ray attenuation and dual modality densitometry techniques using RBF neural network in order to recognize the flow regime and determine the void fraction in gas-liquid two phase flows independent of the liquid phase changes. The proposed system is consisted of one 137 Cs source, two transmission detectors and one scattering detector. The registered counts in two transmission detectors were used as the inputs of one primary Radial Basis Function (RBF) neural network for recognizing the flow regime independent of liquid phase density. Then, after flow regime identification, three RBF neural networks were utilized for determining the void fraction independent of liquid phase density. Registered count in scattering detector and first transmission detector were used as the inputs of these three RBF neural networks. Using this simple methodology, all the flow patterns were correctly recognized and the void fraction was predicted independent of liquid phase density with mean relative error (MRE) of less than 3.28%. Copyright © 2017 Elsevier Ltd. All rights reserved.

Pile-up correction algorithm based on successive integration for high count rate medical imaging and radiation spectroscopy

NASA Astrophysics Data System (ADS)

Mohammadian-Behbahani, Mohammad-Reza; Saramad, Shahyar

2018-07-01

In high count rate radiation spectroscopy and imaging, detector output pulses tend to pile up due to high interaction rate of the particles with the detector. Pile-up effects can lead to a severe distortion of the energy and timing information. Pile-up events are conventionally prevented or rejected by both analog and digital electronics. However, for decreasing the exposure times in medical imaging applications, it is important to maintain the pulses and extract their true information by pile-up correction methods. The single-event reconstruction method is a relatively new model-based approach for recovering the pulses one-by-one using a fitting procedure, for which a fast fitting algorithm is a prerequisite. This article proposes a fast non-iterative algorithm based on successive integration which fits the bi-exponential model to experimental data. After optimizing the method, the energy spectra, energy resolution and peak-to-peak count ratios are calculated for different counting rates using the proposed algorithm as well as the rejection method for comparison. The obtained results prove the effectiveness of the proposed method as a pile-up processing scheme designed for spectroscopic and medical radiation detection applications.

Fast radio burst event rate counts - I. Interpreting the observations

NASA Astrophysics Data System (ADS)

Macquart, J.-P.; Ekers, R. D.

2018-02-01

The fluence distribution of the fast radio burst (FRB) population (the `source count' distribution, N (>F) ∝Fα), is a crucial diagnostic of its distance distribution, and hence the progenitor evolutionary history. We critically reanalyse current estimates of the FRB source count distribution. We demonstrate that the Lorimer burst (FRB 010724) is subject to discovery bias, and should be excluded from all statistical studies of the population. We re-examine the evidence for flat, α > -1, source count estimates based on the ratio of single-beam to multiple-beam detections with the Parkes multibeam receiver, and show that current data imply only a very weak constraint of α ≲ -1.3. A maximum-likelihood analysis applied to the portion of the Parkes FRB population detected above the observational completeness fluence of 2 Jy ms yields α = -2.6_{-1.3}^{+0.7 }. Uncertainties in the location of each FRB within the Parkes beam render estimates of the Parkes event rate uncertain in both normalizing survey area and the estimated post-beam-corrected completeness fluence; this uncertainty needs to be accounted for when comparing the event rate against event rates measured at other telescopes.

A mercuric iodide detector system for X-ray astronomy. II - Results from flight tests of a balloon borne instrument

NASA Technical Reports Server (NTRS)

Vallerga, J. V.; Vanderspek, R. K.; Ricker, G. R.

1983-01-01

To establish the expected sensitivity of a new hard X-ray telescope design, described by Ricker et al., an experiment was conducted to measure the background counting rate at balloon altitudes (40 km) of mercuric iodide, a room temperature solid state X-ray detector. The prototype detector consisted of two thin mercuric iodide (HgI2) detectors surrounded by a large bismuth germanate scintillator operated in anticoincidence. The bismuth germanate shield vetoed most of the background counting rate induced by atmospheric gamma-rays, neutrons and cosmic rays. A balloon-borne gondola containing a prototype detector assembly was designed, constructed and flown twice in the spring of 1982 from Palestine, TX. The second flight of this instrument established a differential background counting rate of 4.2 + or - 0.7 x 10 to the -5th counts/s sq cm keV over the energy range of 40-80 keV. This measurement was within 50 percent of the predicted value. The measured rate is about 5 times lower than previously achieved in shielded NaI/CsI or Ge systems operating in the same energy range.

The Money/Counting Kit. The Prospectus Series, Paper No. 6.

ERIC Educational Resources Information Center

Musumeci, Judith

The Money/Counting Kit for Handicapped Children and Youth, frees the teacher from lessons in money and counting concepts and enables a student to learn at his own rate with immediate feedback from activity cards, name cards, thermoformed coin cards (optional), and self-instructional booklets. The activity cards, which may be used individually or…

Development of an Object-Oriented Turbomachinery Analysis Code within the NPSS Framework

NASA Technical Reports Server (NTRS)

Jones, Scott M.

2014-01-01

During the preliminary or conceptual design phase of an aircraft engine, the turbomachinery designer has a need to estimate the effects of a large number of design parameters such as flow size, stage count, blade count, radial position, etc. on the weight and efficiency of a turbomachine. Computer codes are invariably used to perform this task however, such codes are often very old, written in outdated languages with arcane input files, and rarely adaptable to new architectures or unconventional layouts. Given the need to perform these kinds of preliminary design trades, a modern 2-D turbomachinery design and analysis code has been written using the Numerical Propulsion System Simulation (NPSS) framework. This paper discusses the development of the governing equations and the structure of the primary objects used in OTAC.

Experimental evaluation of the extended Dytlewski-style dead time correction formalism for neutron multiplicity counting

DOE PAGES

Lockhart, M.; Henzlova, D.; Croft, S.; ...

2017-09-20

Over the past few decades, neutron multiplicity counting has played an integral role in Special Nuclear Material (SNM) characterization pertaining to nuclear safeguards. Current neutron multiplicity analysis techniques use singles, doubles, and triples count rates because a methodology to extract and dead time correct higher order count rates (i.e. quads and pents) was not fully developed. This limitation is overcome by the recent extension of a popular dead time correction method developed by Dytlewski. This extended dead time correction algorithm, named Dytlewski-Croft-Favalli (DCF), is detailed in reference Croft and Favalli (2017), which gives an extensive explanation of the theory andmore » implications of this new development. Dead time corrected results can then be used to assay SNM by inverting a set of extended point model equations which as well have only recently been formulated. Here, we discuss and present the experimental evaluation of practical feasibility of the DCF dead time correction algorithm to demonstrate its performance and applicability in nuclear safeguards applications. In order to test the validity and effectiveness of the dead time correction for quads and pents, 252Cf and SNM sources were measured in high efficiency neutron multiplicity counters at the Los Alamos National Laboratory (LANL) and the count rates were extracted up to the fifth order and corrected for dead time. To assess the DCF dead time correction, the corrected data is compared to traditional dead time correction treatment within INCC. In conclusion, the DCF dead time correction is found to provide adequate dead time treatment for broad range of count rates available in practical applications.« less

Experimental evaluation of the extended Dytlewski-style dead time correction formalism for neutron multiplicity counting

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

Lockhart, M.; Henzlova, D.; Croft, S.

Over the past few decades, neutron multiplicity counting has played an integral role in Special Nuclear Material (SNM) characterization pertaining to nuclear safeguards. Current neutron multiplicity analysis techniques use singles, doubles, and triples count rates because a methodology to extract and dead time correct higher order count rates (i.e. quads and pents) was not fully developed. This limitation is overcome by the recent extension of a popular dead time correction method developed by Dytlewski. This extended dead time correction algorithm, named Dytlewski-Croft-Favalli (DCF), is detailed in reference Croft and Favalli (2017), which gives an extensive explanation of the theory andmore » implications of this new development. Dead time corrected results can then be used to assay SNM by inverting a set of extended point model equations which as well have only recently been formulated. Here, we discuss and present the experimental evaluation of practical feasibility of the DCF dead time correction algorithm to demonstrate its performance and applicability in nuclear safeguards applications. In order to test the validity and effectiveness of the dead time correction for quads and pents, 252Cf and SNM sources were measured in high efficiency neutron multiplicity counters at the Los Alamos National Laboratory (LANL) and the count rates were extracted up to the fifth order and corrected for dead time. To assess the DCF dead time correction, the corrected data is compared to traditional dead time correction treatment within INCC. In conclusion, the DCF dead time correction is found to provide adequate dead time treatment for broad range of count rates available in practical applications.« less

Thrombocytopenia in Small for Gestational Age Infants

PubMed Central

Christensen, Robert D.; Baer, Vickie L.; Henry, Erick; Snow, Gregory L.; Butler, Allison; Sola-Visner, Martha C.

2016-01-01

BACKGROUND Thrombocytopenia is common among small for gestational age neonates (SGA; birth weight <10th % reference range) but several aspects of this thrombocytopenia are unclear, including the incidence, typical nadir, duration, association with preeclampsia, mechanism, and risk of death. METHODS Using nine years of multihospital records we studied SGA neonates with ≥2 platelet counts <150,000/μL in their first week. RESULTS We found first-week thrombocytopenia in 31% (905 of 2891) of SGA neonates vs. 10% of non-SGA matched-controls (p<0.0001). One hundred-two of the 905 had a recognized cause of thrombocytopenia (DIC, early-onset sepsis, ECMO). This group had a 65% mortality rate. The remaining 803 did not have an obvious cause for their thrombocytopenia. We termed these the “thrombocytopenia of SGA”. They had a mortality rate of 2% (p<0.0001) and a mean nadir count on day 4 of 93,000/μL (standard deviation, 51,580/μL, 10th % 50,000/μL, 90th % 175,000/μL). By day 14, platelet counts were ≥150,000/μL in >half of the patients. Severely SGA neonates (<1st %) had lower counts and longer thrombocytopenia duration (p<0.001). High nucleated red cell counts at birth correlated with low platelets (p<0.0001). Platelet transfusions were given to 23% and counts typically >tripled. Thrombocytopenia was associated with SGA status more so than with the diagnosis of maternal preeclampsia. CONCLUSIONS SGA neonates with clearly recognized varieties of thrombocytopenia have a high mortality rate. In contrast the “thrombocytopenia of SGA” is a hyporegenerative condition of moderate severity and two weeks duration, associated with evidence of intrauterine hypoxia, and associated with a low mortality rate. PMID:26216323

Sperm count as a surrogate endpoint for male fertility control.

PubMed

Benda, Norbert; Gerlinger, Christoph

2007-11-30

When assessing the effectiveness of a hormonal method of fertility control in men, the classical approach used for the assessment of hormonal contraceptives in women, by estimating the pregnancy rate or using a life-table analysis for the time to pregnancy, is difficult to apply in a clinical development program. The main reasons are the dissociation of the treated unit, i.e. the man, and the observed unit, i.e. his female partner, the high variability in the frequency of male intercourse, the logistical cost and ethical concerns related to the monitoring of the trial. A reasonable surrogate endpoint of the definite endpoint time to pregnancy is sperm count. In addition to the avoidance of the mentioned problems, trials that compare different treatments are possible with reasonable sample sizes, and study duration can be shorter. However, current products do not suppress sperm production to 100 per cent in all men and the sperm count is only observed with measurement error. Complete azoospermia might not be necessary in order to achieve an acceptable failure rate compared with other forms of male fertility control. Therefore, the use of sperm count as a surrogate endpoint must rely on the results of a previous trial in which both the definitive- and surrogate-endpoint results were assessed. The paper discusses different estimation functions of the mean pregnancy rate (corresponding to the cumulative hazard) that are based on the results of sperm count trial and a previous trial in which both sperm count and time to pregnancy were assessed, as well as the underlying assumptions. Sample size estimations are given for pregnancy rate estimation with a given precision.

Use of Surveillance Data on HIV Diagnoses with HIV-Related Symptoms to Estimate the Number of People Living with Undiagnosed HIV in Need of Antiretroviral Therapy

PubMed Central

van Sighem, Ard; Sabin, Caroline A.; Phillips, Andrew N.

2015-01-01

Background It is important to have methods available to estimate the number of people who have undiagnosed HIV and are in need of antiretroviral therapy (ART). Methods The method uses the concept that a predictable level of occurrence of AIDS or other HIV-related clinical symptoms which lead to presentation for care, and hence diagnosis of HIV, arises in undiagnosed people with a given CD4 count. The method requires surveillance data on numbers of new HIV diagnoses with HIV-related symptoms, and the CD4 count at diagnosis. The CD4 count-specific rate at which HIV-related symptoms develop are estimated from cohort data. 95% confidence intervals can be constructed using a simple simulation method. Results For example, if there were 13 HIV diagnoses with HIV-related symptoms made in one year with CD4 count at diagnosis between 150–199 cells/mm3, then since the CD4 count-specific rate of HIV-related symptoms is estimated as 0.216 per person-year, the estimated number of person years lived in people with undiagnosed HIV with CD4 count 150–199 cells/mm3 is 13/0.216 = 60 (95% confidence interval: 29–100), which is considered an estimate of the number of people living with undiagnosed HIV in this CD4 count stratum. Conclusions The method is straightforward to implement within a short period once a surveillance system of all new HIV diagnoses, collecting data on HIV-related symptoms at diagnosis, is in place and is most suitable for estimating the number of undiagnosed people with CD4 count <200 cells/mm3 due to the low rate of developing HIV-related symptoms at higher CD4 counts. A potential source of bias is under-diagnosis and under-reporting of diagnoses with HIV-related symptoms. Although this method has limitations as with all approaches, it is important for prompting increased efforts to identify undiagnosed people, particularly those with low CD4 count, and for informing levels of unmet need for ART. PMID:25768925

Use of surveillance data on HIV diagnoses with HIV-related symptoms to estimate the number of people living with undiagnosed HIV in need of antiretroviral therapy.

PubMed

Lodwick, Rebecca K; Nakagawa, Fumiyo; van Sighem, Ard; Sabin, Caroline A; Phillips, Andrew N

2015-01-01

It is important to have methods available to estimate the number of people who have undiagnosed HIV and are in need of antiretroviral therapy (ART). The method uses the concept that a predictable level of occurrence of AIDS or other HIV-related clinical symptoms which lead to presentation for care, and hence diagnosis of HIV, arises in undiagnosed people with a given CD4 count. The method requires surveillance data on numbers of new HIV diagnoses with HIV-related symptoms, and the CD4 count at diagnosis. The CD4 count-specific rate at which HIV-related symptoms develop are estimated from cohort data. 95% confidence intervals can be constructed using a simple simulation method. For example, if there were 13 HIV diagnoses with HIV-related symptoms made in one year with CD4 count at diagnosis between 150-199 cells/mm3, then since the CD4 count-specific rate of HIV-related symptoms is estimated as 0.216 per person-year, the estimated number of person years lived in people with undiagnosed HIV with CD4 count 150-199 cells/mm3 is 13/0.216 = 60 (95% confidence interval: 29-100), which is considered an estimate of the number of people living with undiagnosed HIV in this CD4 count stratum. The method is straightforward to implement within a short period once a surveillance system of all new HIV diagnoses, collecting data on HIV-related symptoms at diagnosis, is in place and is most suitable for estimating the number of undiagnosed people with CD4 count <200 cells/mm3 due to the low rate of developing HIV-related symptoms at higher CD4 counts. A potential source of bias is under-diagnosis and under-reporting of diagnoses with HIV-related symptoms. Although this method has limitations as with all approaches, it is important for prompting increased efforts to identify undiagnosed people, particularly those with low CD4 count, and for informing levels of unmet need for ART.

Prognostic implication of simultaneous anemia and lymphopenia during concurrent chemoradiotherapy in cervical squamous cell carcinoma.

PubMed

Cho, Oyeon; Chun, Mison; Oh, Young-Taek; Noh, O Kyu; Chang, Suk-Joon; Ryu, Hee-Sug; Lee, Eun Ju

2017-10-01

Radioresistance often leads to poor survival in concurrent chemoradiotherapy-treated cervical squamous cell carcinoma, and reliable biomarkers can improve prognosis. We compared the prognostic potential of hemoglobin, absolute neutrophil count, and absolute lymphocyte count with that of squamous cell carcinoma antigen in concurrent chemoradiotherapy-treated squamous cell carcinoma. We analyzed 152 patients with concurrent chemoradiotherapy and high-dose-rate intracavitary brachytherapy-treated cervical squamous cell carcinoma. Hemoglobin, absolute neutrophil count, absolute lymphocyte count, and squamous cell carcinoma antigen were quantitated and correlated with survival, using Cox regression, receiver operating characteristic curve analysis, and Kaplan-Meier plots. Both hemoglobin and absolute lymphocyte count in the second week of concurrent chemoradiotherapy (Hb2 and ALC2) and squamous cell carcinoma antigen in the third week of concurrent chemoradiotherapy (mid-squamous cell carcinoma antigen) correlated significantly with disease-specific survival and progression-free survival. The ratio of high-dose-rate intracavitary brachytherapy dose to total dose (high-dose-rate intracavitary brachytherapy ratio) correlated significantly with progression-free survival. Patients with both low Hb2 (≤11 g/dL) and ALC2 (≤639 cells/µL) showed a lower 5-year disease-specific survival rate than those with high Hb2 and/or ALC2, regardless of mid-squamous cell carcinoma antigen (mid-squamous cell carcinoma antigen: ≤4.7 ng/mL; 5-year disease-specific survival rate: 85.5% vs 94.6%, p = 0.0096, and mid-squamous cell carcinoma antigen: >4.7 ng/mL; 5-year disease-specific survival rate: 43.8% vs 66.7%, p = 0.192). When both Hb2 and ALC2 were low, the low high-dose-rate intracavitary brachytherapy ratio (≤0.43) subgroup displayed significantly lower 5-year disease-specific survival rate compared to the subgroup high high-dose-rate intracavitary brachytherapy ratio (>0.43) (62.5% vs 88.2%, p = 0.0067). Patients with both anemia and lymphopenia during concurrent chemoradiotherapy showed poor survival, independent of mid-squamous cell carcinoma antigen, and escalating high-dose-rate intracavitary brachytherapy ratio might improve survival.

Ultra-fast photon counting with a passive quenching silicon photomultiplier in the charge integration regime

NASA Astrophysics Data System (ADS)

Zhang, Guoqing; Lina, Liu

2018-02-01

An ultra-fast photon counting method is proposed based on the charge integration of output electrical pulses of passive quenching silicon photomultipliers (SiPMs). The results of the numerical analysis with actual parameters of SiPMs show that the maximum photon counting rate of a state-of-art passive quenching SiPM can reach ~THz levels which is much larger than that of the existing photon counting devices. The experimental procedure is proposed based on this method. This photon counting regime of SiPMs is promising in many fields such as large dynamic light power detection.

Comparisons of monthly mean cosmic ray counting rates observes from worldwide network of neutron monitors

NASA Technical Reports Server (NTRS)

Ryu, J. Y.; Wada, M.

1985-01-01

In order to examine the stability of neutron monitor observation, each of the monthly average counting rates of a neutron monitors is correlated to those of Kiel neutron monitor. The regression coefficients thus obtained are compared with the coupling coefficients of isotropic intensity radiation. The results of the comparisons for five year periods during 1963 to 1982, and for whole period are given. The variation spectrum with a single power law with an exponent of -0.75 up to 50 GV is not so unsatisfactory one. More than one half of the stations show correlations with the coefficient greater than 0.9. Some stations have shifted the level of mean counting rates by changing the instrumental characteristics which can be adjusted.

The relative efficiency of Iranian's rural traffic police: a three-stage DEA model.

PubMed

Rahimi, Habibollah; Soori, Hamid; Nazari, Seyed Saeed Hashemi; Motevalian, Seyed Abbas; Azar, Adel; Momeni, Eskandar; Javartani, Mehdi

2017-10-13

Road traffic Injuries (RTIs) as a health problem imposes governments to implement different interventions. Target achievement in this issue required effective and efficient measures. Efficiency evaluation of traffic police as one of the responsible administrators is necessary for resource management. Therefore, this study conducted to measure Iran's rural traffic police efficiency. This was an ecological study. To obtain pure efficiency score, three-stage DEA model was conducted with seven inputs and three output variables. At the first stage, crude efficiency score was measured with BCC-O model. Next, to extract the effects of socioeconomic, demographic, traffic count and road infrastructure as the environmental variables and statistical noise, the Stochastic Frontier Analysis (SFA) model was applied and the output values were modified according to similar environment and statistical noise conditions. Then, the pure efficiency score was measured using modified outputs and BCC-O model. In total, the efficiency score of 198 police stations from 24 provinces of 31 provinces were measured. The annual means (standard deviation) of damage, injury and fatal accidents were 247.7 (258.4), 184.9 (176.9), and 28.7 (19.5), respectively. Input averages were 5.9 (3.0) patrol teams, 0.5% (0.2) manpower proportions, 7.5 (2.9) patrol cars, 0.5 (1.3) motorcycles, 77,279.1 (46,794.7) penalties, 90.9 (2.8) cultural and educational activity score, 0.7 (2.4) speed cameras. The SFA model showed non-significant differences between police station performances and the most differences attributed to the environmental and random error. One-way main road, by road, traffic count and the number of household owning motorcycle had significant positive relations with inefficiency score. The length of freeway/highway and literacy rate variables had negative relations, significantly. Pure efficiency score was with mean of 0.95 and SD of 0.09. Iran's traffic police has potential opportunity to reduce RTIs. Adjusting police performance with environmental conditions is necessary. Capability of DEA method in setting quantitative targets for every station induces motivation for managers to reduce RTIs. Repetition of this study is recommended, annually.

ChromAIX2: A large area, high count-rate energy-resolving photon counting ASIC for a Spectral CT Prototype

NASA Astrophysics Data System (ADS)

Steadman, Roger; Herrmann, Christoph; Livne, Amir

2017-08-01

Spectral CT based on energy-resolving photon counting detectors is expected to deliver additional diagnostic value at a lower dose than current state-of-the-art CT [1]. The capability of simultaneously providing a number of spectrally distinct measurements not only allows distinguishing between photo-electric and Compton interactions but also discriminating contrast agents that exhibit a K-edge discontinuity in the absorption spectrum, referred to as K-edge Imaging [2]. Such detectors are based on direct converting sensors (e.g. CdTe or CdZnTe) and high-rate photon counting electronics. To support the development of Spectral CT and show the feasibility of obtaining rates exceeding 10 Mcps/pixel (Poissonian observed count-rate), the ChromAIX ASIC has been previously reported showing 13.5 Mcps/pixel (150 Mcps/mm2 incident) [3]. The ChromAIX has been improved to offer the possibility of a large area coverage detector, and increased overall performance. The new ASIC is called ChromAIX2, and delivers count-rates exceeding 15 Mcps/pixel with an rms-noise performance of approximately 260 e-. It has an isotropic pixel pitch of 500 μm in an array of 22×32 pixels and is tile-able on three of its sides. The pixel topology consists of a two stage amplifier (CSA and Shaper) and a number of test features allowing to thoroughly characterize the ASIC without a sensor. A total of 5 independent thresholds are also available within each pixel, allowing to acquire 5 spectrally distinct measurements simultaneously. The ASIC also incorporates a baseline restorer to eliminate excess currents induced by the sensor (e.g. dark current and low frequency drifts) which would otherwise cause an energy estimation error. In this paper we report on the inherent electrical performance of the ChromAXI2 as well as measurements obtained with CZT (CdZnTe)/CdTe sensors and X-rays and radioactive sources.

Multiplicity counting from fission detector signals with time delay effects

NASA Astrophysics Data System (ADS)

Nagy, L.; Pázsit, I.; Pál, L.

2018-03-01

In recent work, we have developed the theory of using the first three auto- and joint central moments of the currents of up to three fission chambers to extract the singles, doubles and triples count rates of traditional multiplicity counting (Pázsit and Pál, 2016; Pázsit et al., 2016). The objective is to elaborate a method for determining the fissile mass, neutron multiplication, and (α, n) neutron emission rate of an unknown assembly of fissile material from the statistics of the fission chamber signals, analogous to the traditional multiplicity counting methods with detectors in the pulse mode. Such a method would be an alternative to He-3 detector systems, which would be free from the dead time problems that would be encountered in high counting rate applications, for example the assay of spent nuclear fuel. A significant restriction of our previous work was that all neutrons born in a source event (spontaneous fission) were assumed to be detected simultaneously, which is not fulfilled in reality. In the present work, this restriction is eliminated, by assuming an independent, identically distributed random time delay for all neutrons arising from one source event. Expressions are derived for the same auto- and joint central moments of the detector current(s) as in the previous case, expressed with the singles, doubles, and triples (S, D and T) count rates. It is shown that if the time-dispersion of neutron detections is of the same order of magnitude as the detector pulse width, as they typically are in measurements of fast neutrons, the multiplicity rates can still be extracted from the moments of the detector current, although with more involved calibration factors. The presented formulae, and hence also the performance of the proposed method, are tested by both analytical models of the time delay as well as with numerical simulations. Methods are suggested also for the modification of the method for large time delay effects (for thermalised neutrons).

Daily step count predicts acute exacerbations in a US cohort with COPD.

PubMed

Moy, Marilyn L; Teylan, Merilee; Weston, Nicole A; Gagnon, David R; Garshick, Eric

2013-01-01

COPD is characterized by variability in exercise capacity and physical activity (PA), and acute exacerbations (AEs). Little is known about the relationship between daily step count, a direct measure of PA, and the risk of AEs, including hospitalizations. In an observational cohort study of 169 persons with COPD, we directly assessed PA with the StepWatch Activity Monitor, an ankle-worn accelerometer that measures daily step count. We also assessed exercise capacity with the 6-minute walk test (6MWT) and patient-reported PA with the St. George's Respiratory Questionnaire Activity Score (SGRQ-AS). AEs and COPD-related hospitalizations were assessed and validated prospectively over a median of 16 months. Mean daily step count was 5804±3141 steps. Over 209 person-years of observation, there were 263 AEs (incidence rate 1.3±1.6 per person-year) and 116 COPD-related hospitalizations (incidence rate 0.56±1.09 per person-year). Adjusting for FEV1 % predicted and prednisone use for AE in previous year, for each 1000 fewer steps per day walked at baseline, there was an increased rate of AEs (rate ratio 1.07; 95%CI = 1.003-1.15) and COPD-related hospitalizations (rate ratio 1.24; 95%CI = 1.08-1.42). There was a significant linear trend of decreasing daily step count by quartiles and increasing rate ratios for AEs (P = 0.008) and COPD-related hospitalizations (P = 0.003). Each 30-meter decrease in 6MWT distance was associated with an increased rate ratio of 1.07 (95%CI = 1.01-1.14) for AEs and 1.18 (95%CI = 1.07-1.30) for COPD-related hospitalizations. Worsening of SGRQ-AS by 4 points was associated with an increased rate ratio of 1.05 (95%CI = 1.01-1.09) for AEs and 1.10 (95%CI = 1.02-1.17) for COPD-related hospitalizations. Lower daily step count, lower 6MWT distance, and worse SGRQ-AS predict future AEs and COPD-related hospitalizations, independent of pulmonary function and previous AE history. These results support the importance of assessing PA in patients with COPD, and provide the rationale to promote PA as part of exacerbation-prevention strategies.

Estimation method for serial dilution experiments.

PubMed

Ben-David, Avishai; Davidson, Charles E

2014-12-01

Titration of microorganisms in infectious or environmental samples is a corner stone of quantitative microbiology. A simple method is presented to estimate the microbial counts obtained with the serial dilution technique for microorganisms that can grow on bacteriological media and develop into a colony. The number (concentration) of viable microbial organisms is estimated from a single dilution plate (assay) without a need for replicate plates. Our method selects the best agar plate with which to estimate the microbial counts, and takes into account the colony size and plate area that both contribute to the likelihood of miscounting the number of colonies on a plate. The estimate of the optimal count given by our method can be used to narrow the search for the best (optimal) dilution plate and saves time. The required inputs are the plate size, the microbial colony size, and the serial dilution factors. The proposed approach shows relative accuracy well within ±0.1log10 from data produced by computer simulations. The method maintains this accuracy even in the presence of dilution errors of up to 10% (for both the aliquot and diluent volumes), microbial counts between 10(4) and 10(12) colony-forming units, dilution ratios from 2 to 100, and plate size to colony size ratios between 6.25 to 200. Published by Elsevier B.V.

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

Erchinger, J. L.; Orrell, John L.; Aalseth, C. E.

The Ultra-Low Background Liquid Scintillation Counter developed by Pacific Northwest National Laboratory will expand the application of liquid scintillation counting by enabling lower detection limits and smaller sample volumes. By reducing the overall count rate of the background environment approximately 2 orders of magnitude below that of commercially available systems, backgrounds on the order of tens of counts per day over an energy range of ~3–3600 keV can be realized. Finally, initial test results of the ULB LSC show promising results for ultra-low background detection with liquid scintillation counting.

Comparative Effectiveness of Two Walking Interventions on Participation, Step Counts, and Health.

PubMed

Smith-McLallen, Aaron; Heller, Debbie; Vernisi, Kristin; Gulick, Diana; Cruz, Samantha; Snyder, Richard L

2017-03-01

To (1) compare the effects of two worksite-based walking interventions on employee participation rates; (2) compare average daily step counts between conditions, and; (3) examine the effects of increases in average daily step counts on biometric and psychologic outcomes. We conducted a cluster-randomized trial in which six employer groups were randomly selected and randomly assigned to condition. Four manufacturing worksites and two office-based worksite served as the setting. A total of 474 employees from six employer groups were included. A standard walking program was compared to an enhanced program that included incentives, feedback, competitive challenges, and monthly wellness workshops. Walking was measured by self-reported daily step counts. Survey measures and biometric screenings were administered at baseline and 3, 6, and 9 months after baseline. Analysis used linear mixed models with repeated measures. During 9 months, participants in the enhanced condition averaged 726 more steps per day compared with those in the standard condition (p < .001). A 1000-step increase in average daily steps was associated with significant weight loss for both men (-3.8 lbs.) and women (-2.1 lbs.), and reductions in body mass index (-0.41 men, -0.31 women). Higher step counts were also associated with improvements in mood, having more energy, and higher ratings of overall health. An enhanced walking program significantly increases participation rates and daily step counts, which were associated with weight loss and reductions in body mass index.

A Neutron Burst Associated with an Extensive Air Shower?

NASA Astrophysics Data System (ADS)

Alves, Mauro; Martin, Inacio; Shkevov, Rumen; Gusev, Anatoly; De Abreu, Alessandro

2016-07-01

A portable and compact system based on a He-3 tube (LND, USA; model 25311) with an area of approximately 250 cm² and is used to record neutron count rates at ground level in the energy range of 0.025 eV to 10 MeV, in São José dos Campos, SP, Brazil (23° 12' 45" S, 45° 52' 00" W; altitude, 660m). The detector, power supply, digitizer and other hardware are housed in an air-conditioned room. The detector power supply and digitizer are not connected to the main electricity network; a high-capacity 12-V battery is used to power the detector and digitizer. Neutron counts are accumulated at 1-minute intervals continuously. The data are stored in a PC for further analysis. In February 8, 2015, at 12 h 22 min (local time) during a period of fair weather with minimal cloud cover (< 1 okta) the neutron detector recorded a sharp (count rate = 27 neutrons/min) and brief (< 1 min) increase in the count rate. In the days before and after this event, the neutron count rate has oscillated between 0 and 3 neutrons/min. Since the occurrence of this event is not related with spurious signals, malfunctioning equipment, oscillations in the mains voltage, etc. we are led to believe that the sharp increase was caused by a physical source such as a an extensive air shower that occurred over the detector.

Performance assessment of self-interrogation neutron resonance densitometry for spent nuclear fuel assay

NASA Astrophysics Data System (ADS)

Hu, Jianwei; Tobin, Stephen J.; LaFleur, Adrienne M.; Menlove, Howard O.; Swinhoe, Martyn T.

2013-11-01

Self-Interrogation Neutron Resonance Densitometry (SINRD) is one of several nondestructive assay (NDA) techniques being integrated into systems to measure spent fuel as part of the Next Generation Safeguards Initiative (NGSI) Spent Fuel Project. The NGSI Spent Fuel Project is sponsored by the US Department of Energy's National Nuclear Security Administration to measure plutonium in, and detect diversion of fuel pins from, spent nuclear fuel assemblies. SINRD shows promising capability in determining the 239Pu and 235U content in spent fuel. SINRD is a relatively low-cost and lightweight instrument, and it is easy to implement in the field. The technique makes use of the passive neutron source existing in a spent fuel assembly, and it uses ratios between the count rates collected in fission chambers that are covered with different absorbing materials. These ratios are correlated to key attributes of the spent fuel assembly, such as the total mass of 239Pu and 235U. Using count rate ratios instead of absolute count rates makes SINRD less vulnerable to systematic uncertainties. Building upon the previous research, this work focuses on the underlying physics of the SINRD technique: quantifying the individual impacts on the count rate ratios of a few important nuclides using the perturbation method; examining new correlations between count rate ratio and mass quantities based on the results of the perturbation study; quantifying the impacts on the energy windows of the filtering materials that cover the fission chambers by tallying the neutron spectra before and after the neutrons go through the filters; and identifying the most important nuclides that cause cooling-time variations in the count rate ratios. The results of these studies show that 235U content has a major impact on the SINRD signal in addition to the 239Pu content. Plutonium-241 and 241Am are the two main nuclides responsible for the variation in the count rate ratio with cooling time. In short, this work provides insights into some of the main factors that affect the performance of SINRD, and it should help improve the hardware design and the algorithm used to interpret the signal for the SINRD technique. In addition, the modeling and simulation techniques used in this work can be easily adopted for analysis of other NDA systems, especially when complex systems like spent nuclear fuel are involved. These studies were conducted at Los Alamos National Laboratory.

Variability of Seasonal CO2 Ice Caps on Mars for Mars Years 26 through 29

NASA Astrophysics Data System (ADS)

Feldman, W. C.; Maurice, S.; Prettyman, T. H.

2011-12-01

We have developed an improved thermal, epithermal, and fast neutron counting-rate time series data of the Mars Odyssey Neutron Spectrometer (MONS), optimized to greatly reduce both statistical and systematic uncertainties. This new data set was applied to study temporal and spatial distributions of the growth, decay, and maximum amount of precipitated CO2 ice during Martian years (MY) 26, 27, 28, and 29. For this study, we concentrate on the epithermal counting rate detected using the down-looking prism (P1) of MONS, and a combination of the epithermal and thermal counting rate detected by the forward-looking sensor (P2) of MONS. Although the energy range of neutrons detected by P2 covers both the thermal and epithermal range, it is heavily weighted to the thermal range. We find that the variance of the maximum epithermal counting rate is remarkably small over both north and south seasonal caps, varying by less than 3% over the four-year period. In contrast, although the maximum P2 counting rate over both poles is sensibly the same within error bars (about 2%) during the first three years, it drops by 18% over the north pole and 8% over the south pole during MY 29. The most-likely explanation of this drop is that abundances of the non-condensable gases N2 and Ar, are unusually enhanced during MY 29. Movies were also made of maps of the growth and decay of P2 counting rates summed over the first three years of these data. Careful inspection shows that both the growth and decay in the north were cylindrically symmetric, centered near the geographic north pole. In contrast, both the growth and decay of CO2 buildup in the south were skewed off the geographic pole to the center of the CO2 residual cap, and contained a small, but definitely distinct ring-like annular enhancement centered at a latitude of about 83.5° S spread over a longitude range that extends between about -35° and +35° E. This arc runs parallel to, and overlays, the very steep drop in altitude from the top of the south-polar CO2/water-ice residual cap at about +4.2 km to the surrounding plains at about +2.5 km. Algorithms developed previously to convert counting rates to CO2 and noncondensable gas column abundance will be applied to interpret the data.

Neural Measures of a Japanese Consonant Length Discrimination by Japanese and American English Listeners: Affects of Attention

PubMed Central

Hisagi, Miwako; Shafer, Valerie L.; Strange, Winifred; Sussman, Elyse S.

2015-01-01

This study examined automaticity of discrimination of a Japanese length contrast for consonants (miʃi vs. miʃʃi) in native (Japanese) and non-native (American-English) listeners using behavioral measures and the event-related potential (ERP) mismatch negativity (MMN). Attention to the auditory input was manipulated either away from the auditory input via a visual oddball task (Visual Attend), or to the input by asking the listeners to count auditory deviants (Auditory Attend). Results showed a larger MMN when attention was focused on the consonant contrast than away from it for both groups. The MMN was larger for consonant duration increments than decrements. No difference in MMN between the language groups was observed, but the Japanese listeners did show better behavioral discrimination than the American English listeners. In addition, behavioral responses showed a weak, but significant correlation with MMN amplitude. These findings suggest that both acoustic-phonetic properties and phonological experience affects automaticity of speech processing. PMID:26119918

Prospects for distinguishing dark matter models using annual modulation

DOE PAGES

Witte, Samuel J.; Gluscevic, Vera; McDermott, Samuel D.

2017-02-24

It has recently been demonstrated that, in the event of a putative signal in dark matter direct detection experiments, properly identifying the underlying dark matter-nuclei interaction promises to be a challenging task. Given the most optimistic expectations for the number counts of recoil events in the forthcoming Generation 2 experiments, differentiating between interactions that produce distinct features in the recoil energy spectra will only be possible if a strong signal is observed simultaneously on a variety of complementary targets. However, there is a wide range of viable theories that give rise to virtually identical energy spectra, and may only differmore » by the dependence of the recoil rate on the dark matter velocity. In this work, we investigate how degeneracy between such competing models may be broken by analyzing the time dependence of nuclear recoils, i.e. the annual modulation of the rate. For this purpose, we simulate dark matter events for a variety of interactions and experiments, and perform a Bayesian model-selection analysis on all simulated data sets, evaluating the chance of correctly identifying the input model for a given experimental setup. Lastly, we find that including information on the annual modulation of the rate may significantly enhance the ability of a single target to distinguish dark matter models with nearly degenerate recoil spectra, but only with exposures beyond the expectations of Generation 2 experiments.« less

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

Witte, Samuel J.; Gluscevic, Vera; McDermott, Samuel D.

It has recently been demonstrated that, in the event of a putative signal in dark matter direct detection experiments, properly identifying the underlying dark matter-nuclei interaction promises to be a challenging task. Given the most optimistic expectations for the number counts of recoil events in the forthcoming Generation 2 experiments, differentiating between interactions that produce distinct features in the recoil energy spectra will only be possible if a strong signal is observed simultaneously on a variety of complementary targets. However, there is a wide range of viable theories that give rise to virtually identical energy spectra, and may only differmore » by the dependence of the recoil rate on the dark matter velocity. In this work, we investigate how degeneracy between such competing models may be broken by analyzing the time dependence of nuclear recoils, i.e. the annual modulation of the rate. For this purpose, we simulate dark matter events for a variety of interactions and experiments, and perform a Bayesian model-selection analysis on all simulated data sets, evaluating the chance of correctly identifying the input model for a given experimental setup. Lastly, we find that including information on the annual modulation of the rate may significantly enhance the ability of a single target to distinguish dark matter models with nearly degenerate recoil spectra, but only with exposures beyond the expectations of Generation 2 experiments.« less

Upgrading a high-throughput spectrometer for high-frequency (<400 kHz) measurements

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

Nishizawa, T., E-mail: nishizawa@wisc.edu; Nornberg, M. D.; Den Hartog, D. J.

2016-11-15

The upgraded spectrometer used for charge exchange recombination spectroscopy on the Madison Symmetric Torus resolves emission fluctuations up to 400 kHz. The transimpedance amplifier’s cutoff frequency was increased based upon simulations comparing the change in the measured photon counts for time-dynamic signals. We modeled each signal-processing stage of the diagnostic and scanned the filtering frequency to quantify the uncertainty in the photon counting rate. This modeling showed that uncertainties can be calculated based on assuming each amplification stage is a Poisson process and by calibrating the photon counting rate with a DC light source to address additional variation.

Upgrading a high-throughput spectrometer for high-frequency (<400 kHz) measurements

NASA Astrophysics Data System (ADS)

Nishizawa, T.; Nornberg, M. D.; Den Hartog, D. J.; Craig, D.

2016-11-01

The upgraded spectrometer used for charge exchange recombination spectroscopy on the Madison Symmetric Torus resolves emission fluctuations up to 400 kHz. The transimpedance amplifier's cutoff frequency was increased based upon simulations comparing the change in the measured photon counts for time-dynamic signals. We modeled each signal-processing stage of the diagnostic and scanned the filtering frequency to quantify the uncertainty in the photon counting rate. This modeling showed that uncertainties can be calculated based on assuming each amplification stage is a Poisson process and by calibrating the photon counting rate with a DC light source to address additional variation.

Disk-based k-mer counting on a PC

PubMed Central

2013-01-01

Background The k-mer counting problem, which is to build the histogram of occurrences of every k-symbol long substring in a given text, is important for many bioinformatics applications. They include developing de Bruijn graph genome assemblers, fast multiple sequence alignment and repeat detection. Results We propose a simple, yet efficient, parallel disk-based algorithm for counting k-mers. Experiments show that it usually offers the fastest solution to the considered problem, while demanding a relatively small amount of memory. In particular, it is capable of counting the statistics for short-read human genome data, in input gzipped FASTQ file, in less than 40 minutes on a PC with 16 GB of RAM and 6 CPU cores, and for long-read human genome data in less than 70 minutes. On a more powerful machine, using 32 GB of RAM and 32 CPU cores, the tasks are accomplished in less than half the time. No other algorithm for most tested settings of this problem and mammalian-size data can accomplish this task in comparable time. Our solution also belongs to memory-frugal ones; most competitive algorithms cannot efficiently work on a PC with 16 GB of memory for such massive data. Conclusions By making use of cheap disk space and exploiting CPU and I/O parallelism we propose a very competitive k-mer counting procedure, called KMC. Our results suggest that judicious resource management may allow to solve at least some bioinformatics problems with massive data on a commodity personal computer. PMID:23679007

Health care resource utilization and characteristics of patients with eosinophilic asthma in secondary health care in Finland.

PubMed

Mäkelä, Mika J; Christensen, Helene Nordahl; Karlsson, Antti; Rastogi, Sarang; Kettunen, Kirsi

2018-01-01

Background : Eosinophilic airway inflammation is common in asthma patients and appears to be associated with severe exacerbations and loss of asthma control. Objective : To describe the resource utilization and clinical characteristics of patients with eosinophilic asthma. Design : Asthma patients ≥18 years with ≥1 blood eosinophil count in secondary care (South West Finland) during 2003‒2013 were included. Clinical characteristics (age, lung function, body mass index, and comorbidities) and asthma-related resource utilization (hospital admissions, outpatient visits, and emergency room [ER] visits) were retrieved. Resource utilization rates were compared for patients with blood eosinophil ≤ or >300 cells/μL, using adjusted negative binomial regression models. Results : Overall, 4,357 eligible patients were identified (mean age 60 years, females 68%), of which 1,927 (44%) had >300 eosinophil cells/μL blood. Patients with ≤300 and >300 eosinophil counts, exhibited similar clinical characteristics, including advanced age, poor lung function, and overweight. Comorbidities such as pneumonia, sinusitis, and nasal polyps, were more frequent among those with >300 eosinophil cells/μL blood compared with patients with lower counts. Eosinophil counts >300 cells/μL were associated with greater hospital admissions (rate ratio [RR] [95% confidence interval CI]: 1.13 [1.02;1.24]) and outpatient visits (RR [95% CI]: 1.11 [1.03;1.20]) compared with patients with lower eosinophil counts. Rates of ER visits were similar between the patient groups (RR [95% CI]: 0.99 [0.87;1.12]). Conclusions : Hospital admissions and outpatient visits occurred more often for patients with eosinophil counts >300 cells/µL, than for patients with lower eosinophil counts. Routine blood eosinophil screening might be useful to identify patients with an eosinophilic phenotype eligible for more targeted treatments.

Acceptability of Early Antiretroviral Therapy Among South African Women.

PubMed

Garrett, Nigel; Norman, Emily; Leask, Kerry; Naicker, Nivashnee; Asari, Villeshni; Majola, Nelisile; Karim, Quarraisha Abdool; Karim, Salim S Abdool

2018-03-01

WHO guidelines recommend immediate initiation of antiretroviral therapy (ART) for all individuals at HIV diagnosis regardless of CD4 count, but concerns remain about potential low uptake or poor adherence among healthy patients with high CD4 counts, especially in resource-limited settings. This study assessed the acceptability of earlier treatment among HIV-positive South African women, median age at enrollment 25 (IQR 22-30), in a 10 year prospective cohort study by (i) describing temporal CD4 count trends at initiation in relation to WHO guidance, (ii) virological suppression rates post-ART initiation at different CD4 count thresholds, and (iii) administration of a standardized questionnaire. 158/232 (68.1%) participants initiated ART between 2006 and 2015. Mean CD4 count at initiation was 217 cells/µl (range 135-372) before 2010, and increased to 531 cells/µl (range 272-1095) by 2015 (p < 0.001). Median viral load at ART initiation decreased over this period from 5.2 (IQR 4.6-5.6) to 4.1 (IQR 3.4-4.6) log copies/ml (p = 0.004). Virological suppression rates at 3, 6, 12 and 18 months were consistently above 85% with no statistically significant differences for participants starting ART at different CD4 count thresholds. A questionnaire assessing uptake of early ART amongst ART-naïve women, median age 28 (IQR 24-33), revealed that 40/51 (78.4%) were willing to start ART at CD4 ≥500. Of those unwilling, 6/11 (54.5%) started ART within 6 months of questionnaire administration. Temporal increases in CD4 counts, comparable virological suppression rates, and positive patient perceptions confirm high acceptability of earlier ART initiation for the majority of patients.

Effects of Sampling Strategy, Detection Probability, and Independence of Counts on the Use of Point Counts

Treesearch

Grey W. Pendleton

1995-01-01

Many factors affect the use of point counts for monitoring bird populations, including sampling strategies, variation in detection rates, and independence of sample points. The most commonly used sampling plans are stratified sampling, cluster sampling, and systematic sampling. Each of these might be most useful for different objectives or field situations. Variation...

An Epidemiologic Investigation of Health Effects in Air Force Personnel Following Exposure to Herbicides: Mortality Update - 1986.

DTIC Science & Technology

1986-12-26

the counts of new deaths in the populations since the last report. Table 3 contains summary counts and death rates by occupation, race and group. All...the last report, due to 2 Ranch Hand ground deaths during 1985. Although the overall Ranch Hand and Comparison death rates of 4.7 and 5.1 percent, shown

SiC-based Photo-detectors for UV, VUV, EUV and Soft X-ray Detection

NASA Technical Reports Server (NTRS)

Yan, Feng

2006-01-01

A viewgraph presentation describing an ideal Silicon Carbide detector for ultraviolet, vacuum ultraviolet, extreme ultraviolet and soft x-ray detection is shown. The topics include: 1) An ideal photo-detector; 2) Dark current density of SiC photodiodes at room temperature; 3) Dark current in SiC detectors; 4) Resistive and capacitive feedback trans-impedance amplifier; 5) Avalanche gain; 6) Excess noise; 7) SNR in single photon counting mode; 8) Structure of SiC single photon counting APD and testing structure; 9) Single photon counting waveform and testing circuit; 10) Amplitude of SiC single photon counter; 11) Dark count of SiC APD photon counters; 12) Temperature-dependence of dark count rate; 13) Reduce the dark count rate by reducing the breakdown electric field; 14) Spectrum range for SiC detectors; 15) QE curves of Pt/4H-SiC photodiodes; 16) QE curve of SiC; 17) QE curves of SiC photodiode vs. penetration depth; 18) Visible rejection of SiC photodiodes; 19) Advantages of SiC photodiodes; 20) Competitors of SiC detectors; 21) Extraterrestrial solar spectra; 22) Visible-blind EUV detection; 23) Terrestrial solar spectra; and 24) Less than 1KeV soft x-ray detection.

Optimization of high count rate event counting detector with Microchannel Plates and quad Timepix readout

NASA Astrophysics Data System (ADS)

Tremsin, A. S.; Vallerga, J. V.; McPhate, J. B.; Siegmund, O. H. W.

2015-07-01

Many high resolution event counting devices process one event at a time and cannot register simultaneous events. In this article a frame-based readout event counting detector consisting of a pair of Microchannel Plates and a quad Timepix readout is described. More than 104 simultaneous events can be detected with a spatial resolution of 55 μm, while >103 simultaneous events can be detected with <10 μm spatial resolution when event centroiding is implemented. The fast readout electronics is capable of processing >1200 frames/sec, while the global count rate of the detector can exceed 5×108 particles/s when no timing information on every particle is required. For the first generation Timepix readout, the timing resolution is limited by the Timepix clock to 10-20 ns. Optimization of the MCP gain, rear field voltage and Timepix threshold levels are crucial for the device performance and that is the main subject of this article. These devices can be very attractive for applications where the photon/electron/ion/neutron counting with high spatial and temporal resolution is required, such as energy resolved neutron imaging, Time of Flight experiments in lidar applications, experiments on photoelectron spectroscopy and many others.

Expected count rate for the Self- Interrogation Neutron Resonance Densitometry measurements of spent nuclear fuel

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

Rossa, Riccardo; Universite libre de Bruxelles, Ecole polytechnique de Bruxelles - Service de Metrologie Nucleaire, CP 165/84, Avenue F.D. Roosevelt, 50 - B1050 Brussels; Borella, Alessandro

The Self-Interrogation Neutron Resonance Densitometry (SINRD) is a passive neutron technique that aims at a direct quantification of {sup 239}Pu in the fuel assemblies by measuring the attenuation of the neutron flux in the energy region close to the 0.3 eV resonance of {sup 239}Pu. The {sup 239}Pu mass is estimated by calculating the SINRD signature, that is the ratio between the neutron flux integrated over the fast energy region and around the 0.3 eV resonance region. The SINRD measurement approach considered in this study consists in introducing a small neutron detector in the central guide tube of a PWRmore » 17x17 fuel assembly. In order to measure the neutron flux in the energy regions defined in the SINRD signature, different detector types are used. The response of a bare {sup 238}U fission chamber is considered for the determination of the fast neutron flux, while other thermal-epithermal detectors wrapped in neutron absorbers are envisaged to measure the neutron flux around the resonance region. This paper provides an estimation of the count rate that can be achieved with the detector types proposed for the SINRD measurement. In the first section a set of detectors are evaluated in terms of count rate and sensitivity to the {sup 239}Pu content, in order to identify the optimal measurement configuration for each detector type. Then a study is performed to increase the count rate by increasing the detector size. The study shows that the highest count rate is achieved by using either {sup 3}He or {sup 10}B proportional counters because of the high neutron efficiency of these detectors. However, the calculations indicate that the biggest contribution to the measurement uncertainty is due to the measurement of the fast neutron flux. Finally, similar sensitivity to the {sup 239}Pu content is obtained by using the different detector types for the measurement of the neutron flux close to the resonance region. Therefore, the count rate associated to each detector type will play a major role in the selection of the detector types used for the SINRD measurement. (authors)« less

Correlation between mastitis occurrence and the count of microorganisms in bulk raw milk of bovine dairy herds in four selective culture media.

PubMed

Souto, Luís I M; Minagawa, Clarice Y; Telles, Evelise O; Garbuglio, Márcio A; Amaku, Marcos; Melville, Priscilla A; Dias, Ricardo A; Sakata, Sonia T; Benites, Nilson R

2010-02-01

Milk is the normal secretion of the mammary gland, practically free of colostrum and obtained by the complete milking of one or more healthy animals. Mastitis is an inflammatory process of the mammary gland and it may cause alterations in the milk. The present work aimed to verify whether it is possible, by means of the counts of microorganism in the bulk raw milk in four selective culture media, to establish a correlation with the occurrence of mastitis and therefore, to monitor this disease in bovine dairy herds. The following selective culture media were used: KF Streptococcus Agar, Edwards Agar, Baird-Parker Agar, Blood Agar plus potassium tellurite. Spearman's correlation coefficient was calculated in order to compare the occurrence of mastitis (percentage) in each herd with respective selective culture media counts of microorganisms in bulk raw milk. Thirty-six possibilities were analysed (Tamis and CMT-positive rates were compared with the log-transformed count in four selective culture media) and there was a negative correlation between Tamis 3 and the Baird-Parker Agar plate count. The total results of microbiological tests showed that there were three correlations of the counts in selective culture media. Fifty-two possibilities were analysed and there was a negative correlation between no-bacterial-growth mastitis rates and log10 of KF Streptoccocus Agar plate count and there were two positive correlations between coagulase-positive staphylococci and log10 of Baird-Parker Agar plate count and Blood Agar plus potassium tellurite plate count.

The Cognitive Advantages of Counting Specifically: A Representational Analysis of Verbal Numeration Systems in Oceanic Languages.

PubMed

Bender, Andrea; Schlimm, Dirk; Beller, Sieghard

2015-10-01

The domain of numbers provides a paradigmatic case for investigating interactions of culture, language, and cognition: Numerical competencies are considered a core domain of knowledge, and yet the development of specifically human abilities presupposes cultural and linguistic input by way of counting sequences. These sequences constitute systems with distinct structural properties, the cross-linguistic variability of which has implications for number representation and processing. Such representational effects are scrutinized for two types of verbal numeration systems-general and object-specific ones-that were in parallel use in several Oceanic languages (English with its general system is included for comparison). The analysis indicates that the object-specific systems outperform the general systems with respect to counting and mental arithmetic, largely due to their regular and more compact representation. What these findings reveal on cognitive diversity, how the conjectures involved speak to more general issues in cognitive science, and how the approach taken here might help to bridge the gap between anthropology and other cognitive sciences is discussed in the conclusion. Copyright © 2015 Cognitive Science Society, Inc.

Novel flat datacenter network architecture based on scalable and flow-controlled optical switch system.

PubMed

Miao, Wang; Luo, Jun; Di Lucente, Stefano; Dorren, Harm; Calabretta, Nicola

2014-02-10

We propose and demonstrate an optical flat datacenter network based on scalable optical switch system with optical flow control. Modular structure with distributed control results in port-count independent optical switch reconfiguration time. RF tone in-band labeling technique allowing parallel processing of the label bits ensures the low latency operation regardless of the switch port-count. Hardware flow control is conducted at optical level by re-using the label wavelength without occupying extra bandwidth, space, and network resources which further improves the performance of latency within a simple structure. Dynamic switching including multicasting operation is validated for a 4 x 4 system. Error free operation of 40 Gb/s data packets has been achieved with only 1 dB penalty. The system could handle an input load up to 0.5 providing a packet loss lower that 10(-5) and an average latency less that 500 ns when a buffer size of 16 packets is employed. Investigation on scalability also indicates that the proposed system could potentially scale up to large port count with limited power penalty.

Enhancing the Linear Dynamic Range in Multi-Channel Single Photon Detector beyond 7OD

PubMed Central

Gudkov, Dmytro; Gudkov, George; Gorbovitski, Boris; Gorfinkel, Vera

2015-01-01

We present design, implementation, and characterization of a single photon detector based on 32-channel PMT sensor [model H7260-20, Hamamatsu]. The developed high speed electronics enables the photon counting with linear dynamic range (LDR) up to 108count/s per detector's channel. The experimental characterization and Monte-Carlo simulations showed that in the single photon counting mode the LDR of the PMT sensor is limited by (i) “photon” pulse width (current pulse) of 900ps and (ii) substantial decrease of amplitudes of current pulses for count rates exceeding 108 count/s. The multi-channel architecture of the detector and the developed firm/software allow further expansion of the dynamic range of the device by 32-fold by using appropriate beam shaping. The developed single photon counting detector was tested for the detection of fluorescence labeled microbeads in capillary flow. PMID:27087788

Research of misalignment between dithered ring laser gyro angle rate input axis and dither axis

NASA Astrophysics Data System (ADS)

Li, Geng; Wu, Wenqi; FAN, Zhenfang; LU, Guangfeng; Hu, Shaomin; Luo, Hui; Long, Xingwu

2014-12-01

The strap-down inertial navigation system (SINS), especially the SINS composed by dithered ring laser gyroscope (DRLG) is a kind of equipment, which providing high reliability and performance for moving vehicles. However, the mechanical dither which is used to eliminate the "Lock-In" effect can cause vibration disturbance to the INS and lead to dithering coupling problem in the inertial measurement unit (IMU) gyroscope triad, so its further application is limited. Among DRLG errors between the true gyro rotation rate and the measured rotation rate, the frequently considered one is the input axis misalignment between input reference axis which is perpendicular to the mounting surface and gyro angular rate input axis. But the misalignment angle between DRLG dither axis and gyro angular rate input axis is often ignored by researchers, which is amplified by dither coupling problem and that would lead to negative effects especially in high accuracy SINS. In order to study the problem more clearly, the concept of misalignment between DRLG dither axis and gyro angle rate input axis is researched. Considering the error of misalignment is of the order of 10-3 rad. or even smaller, the best way to measure it is using DRLG itself by means of an angle exciter as an auxiliary. In this paper, the concept of dither axis misalignment is explained explicitly firstly, based on this, the frequency of angle exciter is induced as reference parameter, when DRLG is mounted on the angle exciter in a certain angle, the projections of angle exciter rotation rate and mechanical oscillation rate on the gyro input axis are both sensed by DRLG. If the dither axis has misalignment error with the gyro input axis, there will be four major frequencies detected: the frequency of angle exciter, the dither mechanical frequency, sum and difference frequencies of the former two frequencies. Then the amplitude spectrum of DRLG output signal obtained by the using LabVIEW program. if there are only angle exciter and the dither mechanical frequencies, the misalignment may be too small to be detected, otherwise, the amplitude of the sum and difference frequencies will show the misalignment angle between the gyro angle rate input axis and the dither axis. Finally, some related parameters such as frequency and amplitude of the angle exciter and sample rate are calculated and the results are analyzed. The simulation and experiment result prove the effectiveness of the proposed method..

Platelet Counts in Insoluble Platelet-Rich Fibrin Clots: A Direct Method for Accurate Determination.

PubMed

Kitamura, Yutaka; Watanabe, Taisuke; Nakamura, Masayuki; Isobe, Kazushige; Kawabata, Hideo; Uematsu, Kohya; Okuda, Kazuhiro; Nakata, Koh; Tanaka, Takaaki; Kawase, Tomoyuki

2018-01-01

Platelet-rich fibrin (PRF) clots have been used in regenerative dentistry most often, with the assumption that growth factor levels are concentrated in proportion to the platelet concentration. Platelet counts in PRF are generally determined indirectly by platelet counting in other liquid fractions. This study shows a method for direct estimation of platelet counts in PRF. To validate this method by determination of the recovery rate, whole-blood samples were obtained with an anticoagulant from healthy donors, and platelet-rich plasma (PRP) fractions were clotted with CaCl 2 by centrifugation and digested with tissue-plasminogen activator. Platelet counts were estimated before clotting and after digestion using an automatic hemocytometer. The method was then tested on PRF clots. The quality of platelets was examined by scanning electron microscopy and flow cytometry. In PRP-derived fibrin matrices, the recovery rate of platelets and white blood cells was 91.6 and 74.6%, respectively, after 24 h of digestion. In PRF clots associated with small and large red thrombi, platelet counts were 92.6 and 67.2% of the respective total platelet counts. These findings suggest that our direct method is sufficient for estimating the number of platelets trapped in an insoluble fibrin matrix and for determining that platelets are distributed in PRF clots and red thrombi roughly in proportion to their individual volumes. Therefore, we propose this direct digestion method for more accurate estimation of platelet counts in most types of platelet-enriched fibrin matrix.

Platelet Counts in Insoluble Platelet-Rich Fibrin Clots: A Direct Method for Accurate Determination

PubMed Central

Kitamura, Yutaka; Watanabe, Taisuke; Nakamura, Masayuki; Isobe, Kazushige; Kawabata, Hideo; Uematsu, Kohya; Okuda, Kazuhiro; Nakata, Koh; Tanaka, Takaaki; Kawase, Tomoyuki

2018-01-01

Platelet-rich fibrin (PRF) clots have been used in regenerative dentistry most often, with the assumption that growth factor levels are concentrated in proportion to the platelet concentration. Platelet counts in PRF are generally determined indirectly by platelet counting in other liquid fractions. This study shows a method for direct estimation of platelet counts in PRF. To validate this method by determination of the recovery rate, whole-blood samples were obtained with an anticoagulant from healthy donors, and platelet-rich plasma (PRP) fractions were clotted with CaCl2 by centrifugation and digested with tissue-plasminogen activator. Platelet counts were estimated before clotting and after digestion using an automatic hemocytometer. The method was then tested on PRF clots. The quality of platelets was examined by scanning electron microscopy and flow cytometry. In PRP-derived fibrin matrices, the recovery rate of platelets and white blood cells was 91.6 and 74.6%, respectively, after 24 h of digestion. In PRF clots associated with small and large red thrombi, platelet counts were 92.6 and 67.2% of the respective total platelet counts. These findings suggest that our direct method is sufficient for estimating the number of platelets trapped in an insoluble fibrin matrix and for determining that platelets are distributed in PRF clots and red thrombi roughly in proportion to their individual volumes. Therefore, we propose this direct digestion method for more accurate estimation of platelet counts in most types of platelet-enriched fibrin matrix. PMID:29450197

Star formation rates and efficiencies in the Galactic Centre

NASA Astrophysics Data System (ADS)

Barnes, A. T.; Longmore, S. N.; Battersby, C.; Bally, J.; Kruijssen, J. M. D.; Henshaw, J. D.; Walker, D. L.

2017-08-01

The inner few hundred parsecs of the Milky Way harbours gas densities, pressures, velocity dispersions, an interstellar radiation field and a cosmic ray ionization rate orders of magnitude higher than the disc; akin to the environment found in star-forming galaxies at high redshift. Previous studies have shown that this region is forming stars at a rate per unit mass of dense gas which is at least an order of magnitude lower than in the disc, potentially violating theoretical predictions. We show that all observational star formation rate diagnostics - both direct counting of young stellar objects and integrated light measurements - are in agreement within a factor two, hence the low star formation rate (SFR) is not the result of the systematic uncertainties that affect any one method. As these methods trace the star formation over different time-scales, from 0.1 to 5 Myr, we conclude that the SFR has been constant to within a factor of a few within this time period. We investigate the progression of star formation within gravitationally bound clouds on ˜parsec scales and find 1-4 per cent of the cloud masses are converted into stars per free-fall time, consistent with a subset of the considered 'volumetric' star formation models. However, discriminating between these models is obstructed by the current uncertainties on the input observables and, most importantly and urgently, by their dependence on ill-constrained free parameters. The lack of empirical constraints on these parameters therefore represents a key challenge in the further verification or falsification of current star formation theories.

Measurement of the Solar Electron Neutrino Flux with the Homestake Chlorine Detector

NASA Astrophysics Data System (ADS)

Cleveland, Bruce T.; Daily, Timothy; Davis, Raymond, Jr.; Distel, James R.; Lande, Kenneth; Lee, C. K.; Wildenhain, Paul S.; Ullman, Jack

1998-03-01

The Homestake Solar Neutrino Detector, based on the inverse beta-decay reaction νe + 37Cl --> 37Ar + e-, has been measuring the flux of solar neutrinos since 1970. The experiment has operated in a stable manner throughout this time period. All aspects of this detector are reviewed, with particular emphasis on the determination of the extraction and counting efficiencies, the key experimental parameters that are necessary to convert the measured 37Ar count rate to the solar neutrino production rate. A thorough consideration is also given to the systematics of the detector, including the measurement of the extraction and counting efficiencies and the nonsolar production of 37Ar. The combined result of 108 extractions is a solar neutrino-induced 37Ar production rate of 2.56 +/- 0.l6 (statistical) +/- 0.16 (systematic) SNU.

Composition of riparian litter input regulates organic matter decomposition: Implications for headwater stream functioning in a managed forest landscape.

PubMed

Lidman, Johan; Jonsson, Micael; Burrows, Ryan M; Bundschuh, Mirco; Sponseller, Ryan A

2017-02-01

Although the importance of stream condition for leaf litter decomposition has been extensively studied, little is known about how processing rates change in response to altered riparian vegetation community composition. We investigated patterns of plant litter input and decomposition across 20 boreal headwater streams that varied in proportions of riparian deciduous and coniferous trees. We measured a suite of in-stream physical and chemical characteristics, as well as the amount and type of litter inputs from riparian vegetation, and related these to decomposition rates of native (alder, birch, and spruce) and introduced (lodgepole pine) litter species incubated in coarse- and fine-mesh bags. Total litter inputs ranged more than fivefold among sites and increased with the proportion of deciduous vegetation in the riparian zone. In line with differences in initial litter quality, mean decomposition rate was highest for alder, followed by birch, spruce, and lodgepole pine (12, 55, and 68% lower rates, respectively). Further, these rates were greater in coarse-mesh bags that allow colonization by macroinvertebrates. Variance in decomposition rate among sites for different species was best explained by different sets of environmental conditions, but litter-input composition (i.e., quality) was overall highly important. On average, native litter decomposed faster in sites with higher-quality litter input and (with the exception of spruce) higher concentrations of dissolved nutrients and open canopies. By contrast, lodgepole pine decomposed more rapidly in sites receiving lower-quality litter inputs. Birch litter decomposition rate in coarse-mesh bags was best predicted by the same environmental variables as in fine-mesh bags, with additional positive influences of macroinvertebrate species richness. Hence, to facilitate energy turnover in boreal headwaters, forest management with focus on conifer production should aim at increasing the presence of native deciduous trees along streams, as they promote conditions that favor higher decomposition rates of terrestrial plant litter.

Contribution of intrinsic properties and synaptic inputs to motoneuron discharge patterns: a simulation study

PubMed Central

ElBasiouny, Sherif M.; Rymer, W. Zev; Heckman, C. J.

2012-01-01

Motoneuron discharge patterns reflect the interaction of synaptic inputs with intrinsic conductances. Recent work has focused on the contribution of conductances mediating persistent inward currents (PICs), which amplify and prolong the effects of synaptic inputs on motoneuron discharge. Certain features of human motor unit discharge are thought to reflect a relatively stereotyped activation of PICs by excitatory synaptic inputs; these features include rate saturation and de-recruitment at a lower level of net excitation than that required for recruitment. However, PIC activation is also influenced by the pattern and spatial distribution of inhibitory inputs that are activated concurrently with excitatory inputs. To estimate the potential contributions of PIC activation and synaptic input patterns to motor unit discharge patterns, we examined the responses of a set of cable motoneuron models to different patterns of excitatory and inhibitory inputs. The models were first tuned to approximate the current- and voltage-clamp responses of low- and medium-threshold spinal motoneurons studied in decerebrate cats and then driven with different patterns of excitatory and inhibitory inputs. The responses of the models to excitatory inputs reproduced a number of features of human motor unit discharge. However, the pattern of rate modulation was strongly influenced by the temporal and spatial pattern of concurrent inhibitory inputs. Thus, even though PIC activation is likely to exert a strong influence on firing rate modulation, PIC activation in combination with different patterns of excitatory and inhibitory synaptic inputs can produce a wide variety of motor unit discharge patterns. PMID:22031773

[Effects of HiLo for two weeks on erythrocyte immune adhesion and leukocyte count of swimmers].

PubMed

Zhao, Yong-Cai; Gao, Bing-Hong; Wu, Ge-Lin; Zhang, Jiu-Li

2012-07-01

To investigate the effects of living high-training low (HiLo) on innate immunity in blood of elite swimmers. Six female swimmers undertook HiLo for two weeks, erythrocyte adhesion function and counts of leukocyte were tested in different time of training period. Red blood cell C3b receptor ring rate (RBC-C3bRR) decreased and red blood cell immune complex matter ring rate (RBC-ICR) increased significantly (P < 0.05), the two markers returned to base line 1 week after training. Counts of leukocyte and granulocyte decreased significantly (P < 0.05), and they recovered 1 week after training; Counts of lymphocyte and monocyte decreased without significance during training and did not recovered after training. Immunity of erythrocyte and granulocyte decreased quickly, but lymphocyte and monocyte recovered slowly, swimmers were adaptive to the training.

Comparison of Kato-Katz thick-smear and McMaster egg counting method for the assessment of drug efficacy against soil-transmitted helminthiasis in school children in Jimma Town, Ethiopia.

PubMed

Bekana, Teshome; Mekonnen, Zeleke; Zeynudin, Ahmed; Ayana, Mio; Getachew, Mestawet; Vercruysse, Jozef; Levecke, Bruno

2015-10-01

There is a paucity of studies that compare efficacy of drugs obtained by different diagnostic methods. We compared the efficacy of a single oral dose albendazole (400 mg), measured as egg reduction rate, against soil-transmitted helminth infections in 210 school children (Jimma Town, Ethiopia) using both Kato-Katz thick smear and McMaster egg counting method. Our results indicate that differences in sensitivity and faecal egg counts did not imply a significant difference in egg reduction rate estimates. The choice of a diagnostic method to assess drug efficacy should not be based on sensitivity and faecal egg counts only. © The Author 2015. Published by Oxford University Press on behalf of Royal Society of Tropical Medicine and Hygiene. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Automatic measurements and computations for radiochemical analyses

USGS Publications Warehouse

Rosholt, J.N.; Dooley, J.R.

1960-01-01

In natural radioactive sources the most important radioactive daughter products useful for geochemical studies are protactinium-231, the alpha-emitting thorium isotopes, and the radium isotopes. To resolve the abundances of these thorium and radium isotopes by their characteristic decay and growth patterns, a large number of repeated alpha activity measurements on the two chemically separated elements were made over extended periods of time. Alpha scintillation counting with automatic measurements and sample changing is used to obtain the basic count data. Generation of the required theoretical decay and growth functions, varying with time, and the least squares solution of the overdetermined simultaneous count rate equations are done with a digital computer. Examples of the complex count rate equations which may be solved and results of a natural sample containing four ??-emitting isotopes of thorium are illustrated. These methods facilitate the determination of the radioactive sources on the large scale required for many geochemical investigations.

Nursing Care Hour Standards Study. Part 2 thru Part 4

DTIC Science & Technology

1981-09-01

pulse area and record results. PULSE - APICAL: Place equipment at bedside, place stethoscope over .5 apex of heart and count rate, remove stethoscope ...equipment at bedside, assist physi- 2 cian with measurement, then remove equipment from area, HEART SOUNDS ASSESSMENT: Place stethoscope at bedside...Remove fingers from pulse area and record results. OR PULSE - APICAL: Place equipment at bedside, place stethoscope over apex of heart and count rate

Performance Evaluation of the microPET®—FOCUS-F120

NASA Astrophysics Data System (ADS)

Laforest, Richard; Longford, Desmond; Siegel, Stefan; Newport, Danny F.; Yap, Jeffrey

2007-02-01

microPETreg-Focus-F120 is the latest model of dedicated small animal PET scanners from CTI-Concorde Microsystems LLC, (Knoxville, TN). This scanner, based on the geometry of the microPET-R4, takes advantage of several detector modifications to the coincidence processing electronics that improve the image resolution, sensitivity, and counting rate performance as compared to the predecessor models. This work evaluates the performance of the Focus-F120 system and shows its improvement over the earlier models. In particular, the spatial resolution is shown to improve from 2.32 to 1.69 mm at 5 mm radial distance and the peak absolute sensitivity increases from 4.1% to 7.1% compared to the microPET-R4. The counting rate capability, expressed in noise equivalent counting rate (NEC-1R), was shown to peak at over 800 kcps at 88 MBq for both systems using a mouse phantom. For this small phantom, the NECR counting rate is limited by the data transmission bandwidth between the scanner and the acquisition console. The rat-like phantom showed peak NEC-1R value at 300 kcps at 140 MBq. Evaluation of image quality and quantitation accuracy was also performed using specially designed phantoms and animal experiments

[Analysis on 2011 quality control results on aerobic plate count of microbiology laboratories in China].

PubMed

Han, Haihong; Li, Ning; Li, Yepeng; Fu, Ping; Yu, Dongmin; Li Zhigang; Du, Chunming; Guo, Yunchang

2015-01-01

To test the aerobic plate count examining capability of microbiology laboratories, to ensure the accuracy and comparability of quantitative bacteria examination results, and to improve the quality of monitoring. The 4 different concentration aerobic plate count piece samples were prepared and noted as I, II, III and IV. After homogeneity and stability tests, the samples were delivered to monitoring institutions. The results of I, II, III samples were logarithmic transformed, and evaluated with Z-score method using the robust average and standard deviation. The results of IV samples were evaluated as "satisfactory" when reported as < 10 CFU/piece or as "not satisfactory" otherwise. Pearson χ2 test was used to analyze the ratio results. 309 monitoring institutions, which was 99.04% of the total number, reported their results. 271 institutions reported a satisfactory result, and the satisfactory rate was 87.70%. There was no statistical difference in satisfactory rates of I, II and III samples which were 81.52%, 88.30% and 91.40% respectively. The satisfactory rate of IV samples was 93.33%. There was no statistical difference in satisfactory rates between provincial and municipal CDC. The quality control program has provided scientific data that the aerobic plate count capability of the laboratories meets the requirements of monitoring tasks.

Bayesian analysis of energy and count rate data for detection of low count rate radioactive sources

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

Klumpp, John

We propose a radiation detection system which generates its own discrete sampling distribution based on past measurements of background. The advantage to this approach is that it can take into account variations in background with respect to time, location, energy spectra, detector-specific characteristics (i.e. different efficiencies at different count rates and energies), etc. This would therefore be a 'machine learning' approach, in which the algorithm updates and improves its characterization of background over time. The system would have a 'learning mode,' in which it measures and analyzes background count rates, and a 'detection mode,' in which it compares measurements frommore » an unknown source against its unique background distribution. By characterizing and accounting for variations in the background, general purpose radiation detectors can be improved with little or no increase in cost. The statistical and computational techniques to perform this kind of analysis have already been developed. The necessary signal analysis can be accomplished using existing Bayesian algorithms which account for multiple channels, multiple detectors, and multiple time intervals. Furthermore, Bayesian machine-learning techniques have already been developed which, with trivial modifications, can generate appropriate decision thresholds based on the comparison of new measurements against a nonparametric sampling distribution. (authors)« less

A mercuric detector system for X-ray astronomy. 2. Results from flight tests of a balloon borne instrument

NASA Technical Reports Server (NTRS)

Vallerga, J.; Vanderspek, R. K.; Ricker, G. R.

1982-01-01

To establish the expected sensitivity of a new hard X-ray telescope design, an experiment was conducted to measure the background counting rate at balloon altitudes (40 km) of mercuric iodide, a room temperature solid state X-ray detector. The prototype detector consisted of two thin mercuric iodide (HgI2) detectors surrounded by a large bismuth germanate (Bi4Ge3O12) scintillator operated in anticoincidence. The bismuth germanate shield vetoed most of the background counting rate induced by atmospheric gamma-rays, neutrons and cosmic rays. A balloon-borne gondola containing a prototype detector assembly was designed, constructed and flown twice in the spring of 1982 from Palestine, Texas. The second flight of this instrument established a differential background counting rate of 4.2 O.7 x 10-5 counts/sec cm keV over the energy range of 40 to 80 keV. This measurement was within 50% of the predicted value. The measured rate is approx 5 times lower than previously achieved in shielded NaI/CsI or Ge systems operating in the same energy range. The prediction was based on a Monte Carlo simulation of the detector assembly in the radiation environment at float altitude.

Dual physiological rate measurement instrument

NASA Technical Reports Server (NTRS)

Cooper, Tommy G. (Inventor)

1990-01-01

The object of the invention is to provide an instrument for converting a physiological pulse rate into a corresponding linear output voltage. The instrument which accurately measures the rate of an unknown rectangular pulse wave over an extended range of values comprises a phase-locked loop including a phase comparator, a filtering network, and a voltage-controlled oscillator, arranged in cascade. The phase comparator has a first input responsive to the pulse wave and a second input responsive to the output signal of the voltage-controlled oscillator. The comparator provides a signal dependent on the difference in phase and frequency between the signals appearing on the first and second inputs. A high-input impedance amplifier accepts an output from the filtering network and provides an amplified output DC signal to a utilization device for providing a measurement of the rate of the pulse wave.

PREDICT: Pattern Representation and Evaluation of Data through Integration, Correlation, and Transformation

DTIC Science & Technology

2015-02-01

than 36ºC; 2) heart rate > 90 beats/min; 3) respiratory rate > 20 breaths/min; and 4) white blood cell count > 12,000/mm3 or < 4,000/mm3 which more than...4) white blood cell count 5) heart rate variability 6) blood pressure The challenge is that once these criteria are met, it is often the case that...Figure 7) was not actually meant to be read (no individual variables or numbers). We believed that showing an increasing size (and color and

Effects of sampling strategy, detection probability, and independence of counts on the use of point counts

USGS Publications Warehouse

Pendleton, G.W.; Ralph, C. John; Sauer, John R.; Droege, Sam

1995-01-01

Many factors affect the use of point counts for monitoring bird populations, including sampling strategies, variation in detection rates, and independence of sample points. The most commonly used sampling plans are stratified sampling, cluster sampling, and systematic sampling. Each of these might be most useful for different objectives or field situations. Variation in detection probabilities and lack of independence among sample points can bias estimates and measures of precision. All of these factors should be con-sidered when using point count methods.

AUTOMATIC COUNTING APPARATUS

DOEpatents

Howell, W.D.

1957-08-20

An apparatus for automatically recording the results of counting operations on trains of electrical pulses is described. The disadvantages of prior devices utilizing the two common methods of obtaining the count rate are overcome by this apparatus; in the case of time controlled operation, the disclosed system automatically records amy information stored by the scaler but not transferred to the printer at the end of the predetermined time controlled operations and, in the case of count controlled operation, provision is made to prevent a weak sample from occupying the apparatus for an excessively long period of time.

UV superconducting nanowire single-photon detectors with high efficiency, low noise, and 4 K operating temperature

NASA Astrophysics Data System (ADS)

Wollman, E. E.; Verma, V. B.; Beyer, A. D.; Briggs, R. M.; Korzh, B.; Allmaras, J. P.; Marsili, F.; Lita, A. E.; Mirin, R. P.; Nam, S. W.; Shaw, M. D.

2017-10-01

For photon-counting applications at ultraviolet wavelengths, there are currently no detectors that combine high efficiency (> 50%), sub-nanosecond timing resolution, and sub-Hz dark count rates. Superconducting nanowire single-photon detectors (SNSPDs) have seen success over the past decade for photon-counting applications in the near-infrared, but little work has been done to optimize SNSPDs for wavelengths below 400 nm. Here, we describe the design, fabrication, and characterization of UV SNSPDs operating at wavelengths between 250 and 370 nm. The detectors have active areas up to 56 ${\\mu}$m in diameter, 70 - 80% efficiency, timing resolution down to 60 ps FWHM, blindness to visible and infrared photons, and dark count rates of ~ 0.25 counts/hr for a 56 ${\\mu}$m diameter pixel. By using the amorphous superconductor MoSi, these UV SNSPDs are also able to operate at temperatures up to 4.2 K. These performance metrics make UV SNSPDs ideal for applications in trapped-ion quantum information processing, lidar studies of the upper atmosphere, UV fluorescent-lifetime imaging microscopy, and photon-starved UV astronomy.

Infant breathing rate counter based on variable resistor for pneumonia

NASA Astrophysics Data System (ADS)

Sakti, Novi Angga; Hardiyanto, Ardy Dwi; La Febry Andira R., C.; Camelya, Kesa; Widiyanti, Prihartini

2016-03-01

Pneumonia is one of the leading causes of death in new born baby in Indonesia. According to WHO in 2002, breathing rate is very important index to be the symptom of pneumonia. In the Community Health Center, the nurses count with a stopwatch for exactly one minute. Miscalculation in Community Health Center occurs because of long time concentration and focus on two object at once. This calculation errors can cause the baby who should be admitted to the hospital only be attended at home. Therefore, an accurate breathing rate counter at Community Health Center level is necessary. In this work, resistance change of variable resistor is made to be breathing rate counter. Resistance change in voltage divider can produce voltage change. If the variable resistance moves periodically, the voltage will change periodically too. The voltage change counted by software in the microcontroller. For the every mm shift at the variable resistor produce average 0.96 voltage change. The software can count the number of wave generated by shifting resistor.

Background considerations in the analysis of PIXE spectra by Artificial Neural Systems.

NASA Astrophysics Data System (ADS)

Correa, R.; Morales, J. R.; Requena, I.; Miranda, J.; Barrera, V. A.

2016-05-01

In order to study the importance of background in PIXE spectra to determine elemental concentrations in atmospheric aerosols using artificial neural systems ANS, two independently trained ANS were constructed, one which considered as input the net number of counts in the peak, and another which included the background. In the training and validation phases thirty eight spectra of aerosols collected in Santiago, Chile, were used. In both cases the elemental concentration values were similar. This fact was due to the intrinsic characteristic of ANS operating with normalized values of the net and total number of counts under the peaks, something that was verified in the analysis of 172 spectra obtained from aerosols collected in Mexico city. Therefore, networks operating under the mode which include background can reduce time and cost when dealing with large number of samples.

Road profiling of traffic accidents in Jos, Nigeria, 1995-1999.

PubMed

Bombom, Leonard S; Edino, Marcus O

2009-09-01

Road traffic accident data in Nigeria generally lack exact coordinate information. Accident analysis is, therefore, restricted to aggregate data on trends, magnitude and temporal dimensions. This article addresses the road accident problem in Jos between 1995 and 1999 through a road profiling approach. Results show that four gateway routes, seven multi-lane roadways (including two gateway routes) and seven road intersections accounted for 84% of all traffic accidents, 84% of injured casualties and 88% of fatalities. This approach allows for quantification of impacts of controlling for accidents by deliberate profiling of roads for close monitoring and policing. For example, reducing accident counts and fatalities by 50% each on gateway routes will amount to approximately 35 and 40% reduction in accident and fatality counts, respectively. Countermeasures must consider these roadways and intersections as important inputs in their accidents and casualty reduction targets.

Application of the support vector machine to predict subclinical mastitis in dairy cattle.

PubMed

Mammadova, Nazira; Keskin, Ismail

2013-01-01

This study presented a potentially useful alternative approach to ascertain the presence of subclinical and clinical mastitis in dairy cows using support vector machine (SVM) techniques. The proposed method detected mastitis in a cross-sectional representative sample of Holstein dairy cattle milked using an automatic milking system. The study used such suspected indicators of mastitis as lactation rank, milk yield, electrical conductivity, average milking duration, and control season as input data. The output variable was somatic cell counts obtained from milk samples collected monthly throughout the 15 months of the control period. Cattle were judged to be healthy or infected based on those somatic cell counts. This study undertook a detailed scrutiny of the SVM methodology, constructing and examining a model which showed 89% sensitivity, 92% specificity, and 50% error in mastitis detection.

Predicting Air Permeability of Handloom Fabrics: A Comparative Analysis of Regression and Artificial Neural Network Models

NASA Astrophysics Data System (ADS)

Mitra, Ashis; Majumdar, Prabal Kumar; Bannerjee, Debamalya

2013-03-01

This paper presents a comparative analysis of two modeling methodologies for the prediction of air permeability of plain woven handloom cotton fabrics. Four basic fabric constructional parameters namely ends per inch, picks per inch, warp count and weft count have been used as inputs for artificial neural network (ANN) and regression models. Out of the four regression models tried, interaction model showed very good prediction performance with a meager mean absolute error of 2.017 %. However, ANN models demonstrated superiority over the regression models both in terms of correlation coefficient and mean absolute error. The ANN model with 10 nodes in the single hidden layer showed very good correlation coefficient of 0.982 and 0.929 and mean absolute error of only 0.923 and 2.043 % for training and testing data respectively.

39 CFR 3010.12 - Contents of notice of rate adjustment.

Code of Federal Regulations, 2014 CFR

2014-07-01

... information must be supported by workpapers in which all calculations are shown and all input values, including all relevant CPI-U values, are listed with citations to the original sources. (2) A schedule... input values, including current rates, new rates, and billing determinants, are listed with citations to...

Mycological studies housed in the Apollo 16 microbial ecology evaluation device

NASA Technical Reports Server (NTRS)

Volz, P. A.

1973-01-01

Survival, death, and phenotype count have yielded variation in the number of fungi recovered from the controls and the flight exposed cuvettes during preliminary analysis of postflight first phase data. Also the preliminary analysis was indicative that fungi exposed to specific space flight conditions demonstrated variable survival rates and phenotype counts. Specific space flight conditions included full light space exposure for Chaetomium globosum, exposure at 300- and 254-nanometer wavelengths for Rhodotorula rubra, full light and 280-nanometer wavelength exposure for Trichophyton terrestre, and 254-nanometer wavelength exposure for Saccharomyces cerevisiae. In general, phenotype counts for flight cuvettes and survival rates for control cuvettes were higher compared with the remaining cuvettes.

Twenty Years of Litter and Root Manipulations: Insights into Multi-Decadal SOM Dynamics and Controls

NASA Astrophysics Data System (ADS)

Wig, J.; Lajtha, K.; Nadelhoffer, K. J.

2012-12-01

Reforestation, reducing deforestation, and sustainable forest management are often recommended by policy makers to mitigate the greenhouse gas contributions of the forestry sector. However, underlying many of these policy recommendations is the assumption that increasing above-ground carbon stocks corresponds to long-term increases in ecosystem carbon stocks, the majority of which is stored in soils. We analyzed soil carbon and nitrogen dynamics in forest soils that had undergone twenty years of continuous manipulations of above- and below-ground organic inputs as part of the Detritus Input and Removal Treatment (DIRT) network. Although we expected that increased C inputs would correspond to significantly elevated C in surface mineral soils, our data suggest that increasing above-ground litter inputs has had a positive priming effect in this soil. Positive priming occurs when increased rates of litter addition to soil lead to disproportionate increases in microbial respiration rates of native soil C, resulting in a net decrease of soil C. Soil respiration rates in a year-long laboratory incubation support this theory: increased above-ground litter inputs led to decreased respiration rates, suggesting a relative deficit of labile organic matter. Removal of below ground inputs, either with or without above-ground litter inputs, also led to decreased respiration in laboratory incubations, demonstrating the importance of fresh root inputs to labile C. Trends in non-hydrolyzable C fractions, a proxy for the more stable C pool, agree with our respiration measurements. Data from sequential density fractionation are consistent with the hypotheses that priming has occurred in response to increased above-ground litter inputs and that root inputs are an important control of the labile C pool. The importance of roots inputs for C stabilization is well documented in the literature, and our hypothesis that increased above-ground litter inputs leads to priming is supported by data from several other DIRT sites. These data indicate there is an important potential loss of ecosystem C due to priming which should be considered when changing organic inputs to the soil, as is the case in some sustainable forestry recommendations.

Effects of high CD4 cell counts on death and attrition among HIV patients receiving antiretroviral treatment: an observational cohort study.

PubMed

Tang, Zhenzhu; Pan, Stephen W; Ruan, Yuhua; Liu, Xuanhua; Su, Jinming; Zhu, Qiuying; Shen, Zhiyong; Zhang, Heng; Chen, Yi; Lan, Guanghua; Xing, Hui; Liao, Lingjie; Feng, Yi; Shao, Yiming

2017-06-09

Current WHO guidelines recommend initiating ART regardless of CD4+ cell count. In response, we conducted an observational cohort study to assess the effects of pre-ART CD4+ cell count levels on death, attrition, and death or attrition in HIV treated patients. This large HIV treatment cohort study (n = 49,155) from 2010 to 2015 was conducted in Guangxi, China. We used a Cox regression model to analyze associations between pre-ART CD4+ cell counts and death, attrition, and death or attrition. The average mortality and ART attrition rates among all treated patients were 2.63 deaths and 5.32 attritions per 100 person-years, respectively. Compared to HIV patients with <350 CD4+ cells/mm 3 at ART initiation, HIV patients with >500 CD4+ cells/mm 3 at ART initiation had a significantly lower mortality rate (Adjusted hazard ratio: 0.56, 95% CI: 0.40-0.79), but significantly higher ART attrition rate (AHR: 1.17, 95% CI: 1.03-1.33). Results from this study suggest that HIV patients with high CD4+ cell counts at the time of ART initiation may be at greater risk of treatment attrition. To further reduce ART attrition, it is imperative that patient education and healthcare provider training on ART adherence be enhanced and account for CD4 levels at ART initiation.

Scale-dependent associations of Band-tailed Pigeon counts at mineral sites

USGS Publications Warehouse

Overton, Cory T.; Casazza, Michael L.; Coates, Peter S.

2010-01-01

The abundance of Band-tailed Pigeons (Patagioenas fasciata monilis) has declined substantially from historic numbers along the Pacific Coast. Identification of patterns and causative factors of this decline are hampered because habitat use data are limited, and temporal and spatial variability patterns associated with population indices are not known. Furthermore, counts are influenced not only by pigeon abundance but also by rate of visitation to mineral sites, which may not be consistent. To address these issues, we conducted mineral site counts during 2001 and 2002 at 20 locations from 4 regions in the Pacific Northwest, including central Oregon and western Washington, USA, and British Columbia, Canada. We developed inference models that consisted of environmental factors and spatial characteristics at multiple spatial scales. Based on information theory, we compared models within a final set that included variables measured at 3 spatial scales (0.03 ha, 3.14 ha, and 7850 ha). Pigeon counts increased from central Oregon through northern Oregon and decreased into British Columbia. After accounting for this spatial pattern, we found that pigeon counts increased 12% ± 2.7 with a 10% increase in the amount of deciduous forested area within 100 m from a mineral site. Also, distance from the mineral site of interest to the nearest known mineral site was positively related to pigeon counts. These findings provide direction for future research focusing on understanding the relationships between indices of relative abundance and complete counts (censuses) of pigeon populations by identifying habitat characteristics that might influence visitation rates. Furthermore, our results suggest that spatial arrangement of mineral sites influences Band-tailed Pigeon counts and the populations which those counts represent.

An Efficient Algorithm for the Detection of Infrequent Rapid Bursts in Time Series Data

NASA Astrophysics Data System (ADS)

Giles, A. B.

1997-01-01

Searching through data for infrequent rapid bursts is a common requirement in many areas of scientific research. In this paper, we present a powerful and flexible analysis method that, in a single pass through the data, searches for statistically significant bursts on a set of specified short timescales. The input data are binned, if necessary, and then quantified in terms of probabilities rather than rates or ratios. Using a measure-like probability makes the method relatively count rate independent. The method has been made computationally efficient by the use of lookup tables and cyclic buffers, and it is therefore particularly well suited to real-time applications. The technique has been developed specifically for use in an X-ray astronomy application to search for millisecond bursts from black hole candidates such as Cyg X-1. We briefly review the few observations of these types of features reported in the literature, as well as the variety of ways in which their statistical reliability was challenged. The developed technique, termed the burst expectation search (BES) method, is illustrated using some data simulations and archived data obtained during ground testing of the proportional counter array (PCA) experiment detectors on the Rossi X-Ray Timing Explorer (RXTE). A potential application for a real-time BES method on board RXTE is also examined.

Electrooculography-based continuous eye-writing recognition system for efficient assistive communication systems

PubMed Central

Shinozaki, Takahiro

2018-01-01

Human-computer interface systems whose input is based on eye movements can serve as a means of communication for patients with locked-in syndrome. Eye-writing is one such system; users can input characters by moving their eyes to follow the lines of the strokes corresponding to characters. Although this input method makes it easy for patients to get started because of their familiarity with handwriting, existing eye-writing systems suffer from slow input rates because they require a pause between input characters to simplify the automatic recognition process. In this paper, we propose a continuous eye-writing recognition system that achieves a rapid input rate because it accepts characters eye-written continuously, with no pauses. For recognition purposes, the proposed system first detects eye movements using electrooculography (EOG), and then a hidden Markov model (HMM) is applied to model the EOG signals and recognize the eye-written characters. Additionally, this paper investigates an EOG adaptation that uses a deep neural network (DNN)-based HMM. Experiments with six participants showed an average input speed of 27.9 character/min using Japanese Katakana as the input target characters. A Katakana character-recognition error rate of only 5.0% was achieved using 13.8 minutes of adaptation data. PMID:29425248

Forecasting Emergency Department Crowding: An External, Multi-Center Evaluation

PubMed Central

Hoot, Nathan R.; Epstein, Stephen K.; Allen, Todd L.; Jones, Spencer S.; Baumlin, Kevin M.; Chawla, Neal; Lee, Anna T.; Pines, Jesse M.; Klair, Amandeep K.; Gordon, Bradley D.; Flottemesch, Thomas J.; LeBlanc, Larry J.; Jones, Ian; Levin, Scott R.; Zhou, Chuan; Gadd, Cynthia S.; Aronsky, Dominik

2009-01-01

Objective To apply a previously described tool to forecast ED crowding at multiple institutions, and to assess its generalizability for predicting the near-future waiting count, occupancy level, and boarding count. Methods The ForecastED tool was validated using historical data from five institutions external to the development site. A sliding-window design separated the data for parameter estimation and forecast validation. Observations were sampled at consecutive 10-minute intervals during 12 months (n = 52,560) at four sites and 10 months (n = 44,064) at the fifth. Three outcome measures – the waiting count, occupancy level, and boarding count – were forecast 2, 4, 6, and 8 hours beyond each observation, and forecasts were compared to observed data at corresponding times. The reliability and calibration were measured following previously described methods. After linear calibration, the forecasting accuracy was measured using the median absolute error (MAE). Results The tool was successfully used for five different sites. Its forecasts were more reliable, better calibrated, and more accurate at 2 hours than at 8 hours. The reliability and calibration of the tool were similar between the original development site and external sites; the boarding count was an exception, which was less reliable at four out of five sites. Some variability in accuracy existed among institutions; when forecasting 4 hours into the future, the MAE of the waiting count ranged between 0.6 and 3.1 patients, the MAE of the occupancy level ranged between 9.0 and 14.5% of beds, and the MAE of the boarding count ranged between 0.9 and 2.7 patients. Conclusion The ForecastED tool generated potentially useful forecasts of input and throughput measures of ED crowding at five external sites, without modifying the underlying assumptions. Noting the limitation that this was not a real-time validation, ongoing research will focus on integrating the tool with ED information systems. PMID:19716629

Feasibility Study and Development of Modular Appliance Technologies, Centralized Heating (MATCH) Field Kitchen

DTIC Science & Technology

1994-07-01

including standby losses. The required input fuel rate is 261.000 Btu/hr ( LHV ) or 277,700 Btu/hr ( HHV ). The Becker burner used in the system is rated at 2...cost of -$6/gallon. Burning diesel fuel , with 20-percent excess air and a final exhaust temperature of 932°F, requires a fuel LHV input of 261,000 Btu...GPH diesel fuel burning rate, corresponding to 280.000 Btu/hr ( HHV ) input. The flue gases leave the fluid heater at a nominal temperature of 932°F

Atmospheric Inputs of Nitrogen, Carbon, and Phosphorus across an Urban Area: Unaccounted Fluxes and Canopy Influences

NASA Astrophysics Data System (ADS)

Decina, Stephen M.; Templer, Pamela H.; Hutyra, Lucy R.

2018-02-01

Rates of atmospheric deposition are declining across the United States, yet urban areas remain hotspots of atmospheric deposition. While past studies show elevated rates of inorganic nitrogen (N) deposition in cities, less is known about atmospheric inputs of organic N, organic carbon (C), and organic and inorganic phosphorus (P), all of which can affect ecosystem processes, water quality, and air quality. Further, the effect of the tree canopy on amounts and forms of nutrients reaching urban ground surfaces is not well-characterized. We measured growing season rates of total N, organic C, and total P in bulk atmospheric inputs, throughfall, and soil solution around the greater Boston area. We found that organic N constitutes a third of total N inputs, organic C inputs are comparable to rural inputs, and inorganic P inputs are 1.2 times higher than those in sewage effluent. Atmospheric inputs are enhanced two-to-eight times in late spring and are elevated beneath tree canopies, suggesting that trees augment atmospheric inputs to ground surfaces. Additionally, throughfall inputs may directly enter runoff when trees extend above impervious surfaces, as is the case with 26.1% of Boston's tree canopy. Our results indicate that the urban atmosphere is a significant source of elemental inputs that may impact urban ecosystems and efforts to improve water quality, particularly in terms of P. Further, as cities create policies encouraging tree planting to provide ecosystem services, locating trees above permeable surfaces to reduce runoff nutrient loads may be essential to managing urban biogeochemical cycling and water quality.

Smartphone Text Input Method Performance, Usability, and Preference With Younger and Older Adults.

PubMed

Smith, Amanda L; Chaparro, Barbara S

2015-09-01

User performance, perceived usability, and preference for five smartphone text input methods were compared with younger and older novice adults. Smartphones are used for a variety of functions other than phone calls, including text messaging, e-mail, and web browsing. Research comparing performance with methods of text input on smartphones reveals a high degree of variability in reported measures, procedures, and results. This study reports on a direct comparison of five of the most common input methods among a population of younger and older adults, who had no experience with any of the methods. Fifty adults (25 younger, 18-35 years; 25 older, 60-84 years) completed a text entry task using five text input methods (physical Qwerty, onscreen Qwerty, tracing, handwriting, and voice). Entry and error rates, perceived usability, and preference were recorded. Both age groups input text equally fast using voice input, but older adults were slower than younger adults using all other methods. Both age groups had low error rates when using physical Qwerty and voice, but older adults committed more errors with the other three methods. Both younger and older adults preferred voice and physical Qwerty input to the remaining methods. Handwriting consistently performed the worst and was rated lowest by both groups. Voice and physical Qwerty input methods proved to be the most effective for both younger and older adults, and handwriting input was the least effective overall. These findings have implications to the design of future smartphone text input methods and devices, particularly for older adults. © 2015, Human Factors and Ergonomics Society.

National, regional, and worldwide estimates of stillbirth rates in 2009 with trends since 1995: a systematic analysis.

PubMed

Cousens, Simon; Blencowe, Hannah; Stanton, Cynthia; Chou, Doris; Ahmed, Saifuddin; Steinhardt, Laura; Creanga, Andreea A; Tunçalp, Ozge; Balsara, Zohra Patel; Gupta, Shivam; Say, Lale; Lawn, Joy E

2011-04-16

Stillbirths do not count in routine worldwide data-collating systems or for the Millennium Development Goals. Two sets of national stillbirth estimates for 2000 produced similar worldwide totals of 3·2 million and 3·3 million, but rates differed substantially for some countries. We aimed to develop more reliable estimates and a time series from 1995 for 193 countries, by increasing input data, using recent data, and applying improved modelling approaches. For international comparison, stillbirth is defined as fetal death in the third trimester (≥1000 g birthweight or ≥28 completed weeks of gestation). Several sources of stillbirth data were identified and assessed against prespecified inclusion criteria: vital registration data; nationally representative surveys; and published studies identified through systematic literature searches, unpublished studies, and national data identified through a WHO country consultation process. For 2009, reported rates were used for 33 countries and model-based estimates for 160 countries. A regression model of log stillbirth rate was developed and used to predict national stillbirth rates from 1995 to 2009. Uncertainty ranges were obtained with a bootstrap approach. The final model included log(neonatal mortality rate) (cubic spline), log(low birthweight rate) (cubic spline), log(gross national income purchasing power parity) (cubic spline), region, type of data source, and definition of stillbirth. Vital registration data from 79 countries, 69 nationally representative surveys from 39 countries, and 113 studies from 42 countries met inclusion criteria. The estimated number of global stillbirths was 2·64 million (uncertainty range 2·14 million to 3·82 million) in 2009 compared with 3·03 million (uncertainty range 2·37 million to 4·19 million) in 1995. Worldwide stillbirth rate has declined by 14·5%, from 22·1 stillbirths per 1000 births in 1995 to 18·9 stillbirths per 1000 births in 2009. In 2009, 76·2% of stillbirths occurred in south Asia and sub-Saharan Africa. This study draws attention to the dearth of reliable data in regions where most stillbirths occur. The estimated trend in stillbirth rate reduction is slower than that for maternal mortality and lags behind the increasing progress in reducing deaths in children younger than 5 years. Improved data and improved use of data are crucial to ensure that stillbirths count in global and national policy. The Bill & Melinda Gates Foundation through the Global Alliance to Prevent Prematurity and Stillbirth, Saving Newborn Lives/Save the Children, and the International Stillbirth Alliance. The Department of Reproductive Health and Research, WHO, through the UN Development Programme, UN Population Fund, WHO, and World Bank Special Programme of Research, Development and Research Training in Human Reproduction. Copyright © 2011 Elsevier Ltd. All rights reserved.

Linear operating region in the ozone dial photon counting system

NASA Technical Reports Server (NTRS)

Andrawis, Madeleine

1995-01-01

Ozone is a relatively unstable molecule found in Earth's atmosphere. An ozone molecule is made up of three atoms of oxygen. Depending on where ozone resides, it can protect or harm life on Earth. High in the atmosphere, about 15 miles up, ozone acts as a shield to protect Earth's surface from the sun's harmful ultraviolet radiation. Without this shield, we would be more susceptible to skin cancer, cataracts, and impaired immune systems. Closer to Earth, in the air we breathe, ozone is a harmful pollutant that causes damage to lung tissue and plants. Since the early 1980's, airborne lidar systems have been used for making measurements of ozone. The differential absorption lidar (DIAL) technique is used in the remote measurement of O3. This system allows the O3 to be measured as function of the range in the atmosphere. Two frequency-doubled Nd:YAG lasers are used to pump tunable dye lasers. The lasers are operating at 289 nm for the DIAL on-line wavelength of O3, and the other one is operated at 300 nm for the off-line wavelength. The DIAL wavelengths are produced in sequential laser pulses with a time separation of 300 micro s. The backscattered laser energy is collected by telescopes and measured using photon counting systems. The photon counting system measures the light signal by making use of the photon nature of light. The output pulse from the Photo-Multiplier Tube (PE), caused by a photon striking the PMT photo-cathode, is amplified and passed to a pulse height discriminator. The peak value of the pulse is compared to a reference voltage (discrimination level). If the pulse amplitude exceeds the discrimination level, the discriminator generates a standard pulse which is counted by the digital counter. Non-linearity in the system is caused by the overlapping of pulses and the finite response time of the electronics. At low count rates one expects the system to register one event for each output pulse from the PMT corresponding to a photon incident upon the photocathode, however, at higher rates the limitations of the discrimination/counting system will cause the observed count rate to be non-linear with respect to the true count rate. Depending on the pulse height distribution and the discriminator level, the overlapping of pulses (pulse pile-up) can cause count loss or even an additional apparent count gain as the signal levels increase. Characterization of the system, including the pulse height distribution, the signal to noise ratio, and the effect of the discriminator threshold level, is critical in maximizing the linear operating region of the system, thus greatly increasing the useful dynamic range of the system.

Dynamic Histogram Analysis To Determine Free Energies and Rates from Biased Simulations.

PubMed

Stelzl, Lukas S; Kells, Adam; Rosta, Edina; Hummer, Gerhard

2017-12-12

We present an algorithm to calculate free energies and rates from molecular simulations on biased potential energy surfaces. As input, it uses the accumulated times spent in each state or bin of a histogram and counts of transitions between them. Optimal unbiased equilibrium free energies for each of the states/bins are then obtained by maximizing the likelihood of a master equation (i.e., first-order kinetic rate model). The resulting free energies also determine the optimal rate coefficients for transitions between the states or bins on the biased potentials. Unbiased rates can be estimated, e.g., by imposing a linear free energy condition in the likelihood maximization. The resulting "dynamic histogram analysis method extended to detailed balance" (DHAMed) builds on the DHAM method. It is also closely related to the transition-based reweighting analysis method (TRAM) and the discrete TRAM (dTRAM). However, in the continuous-time formulation of DHAMed, the detailed balance constraints are more easily accounted for, resulting in compact expressions amenable to efficient numerical treatment. DHAMed produces accurate free energies in cases where the common weighted-histogram analysis method (WHAM) for umbrella sampling fails because of slow dynamics within the windows. Even in the limit of completely uncorrelated data, where WHAM is optimal in the maximum-likelihood sense, DHAMed results are nearly indistinguishable. We illustrate DHAMed with applications to ion channel conduction, RNA duplex formation, α-helix folding, and rate calculations from accelerated molecular dynamics. DHAMed can also be used to construct Markov state models from biased or replica-exchange molecular dynamics simulations. By using binless WHAM formulated as a numerical minimization problem, the bias factors for the individual states can be determined efficiently in a preprocessing step and, if needed, optimized globally afterward.

The normalization of solar X-ray data from many experiments.

NASA Technical Reports Server (NTRS)

Wende, C. D.

1972-01-01

A conversion factor is used to convert Geiger (GM) tube count rates or ion chamber currents into units of the incident X-ray energy flux in a specified passband. A method is described which varies the passband to optimize these conversion factors such that they are relatively independent of the spectrum of the incident photons. This method was applied to GM tubes flown on Explorers 33 and 35 and Mariner 5 and to ion chambers flown on OSO 3 and OGO 4. Revised conversion factors and passbands are presented, and the resulting absolute solar X-ray fluxes based on these are shown to improve the agreement between the various experiments. Calculations have shown that, although the GM tubes on Explorer 33 viewed the Sun off-axis, the effective passband did not change appreciably, and the simple normalization of the count rates to the count rates of a similar GM tube on Explorer 35 was justified.

Asm-Triggered too Observations of 100,000 C/s Black Hole Candidates

NASA Astrophysics Data System (ADS)

van der Klis, Michiel

One of the most valuable unique characteristics of the PCA is the high count rates (100,000 c/s) it can record, and the resulting extreme sensitivity to weak variability. Only few sources get this bright. Our Cycle-1 work on Sco X-1 has shown that performing high count rate observations is very rewarding, but also difficult and not without risk. In the life of the satellite probably only one black-hole transient (if any) will reach 100,000 c/s levels. When this occurs, a window of discovery will be opened on black holes, which will nearly certainly close again within a few days. This proposal aims at ensuring that optimal use is made of this opportunity by performing state-of-the-art high count rate observations covering all of the most crucial aspects of the source variability.

Asm-Triggered too Observations of 100,000 C/s Black Hole Candidates

NASA Astrophysics Data System (ADS)

van der Klis, Michiel

Resubmission accepted Cycle 2-7 proposal. - The PCA is unique by the high count rates (~100,000 c/s) it can record, and its resulting extreme sensitivity to weak variability. Only few sources get this bright. Our RXTE work on Sco X-1 and 1744-28 shows that high count rate observations are very rewarding, but also difficult and not without risk. In the life of the satellite probably only one black-hole transient (if any) will reach 10^5 c/s/5PCU levels. When this occurs, a window of discovery will be opened on black holes, which will nearly certainly close again within a few days. This proposal aims at ensuring that optimal use is made of this opportunity by performing state-of- the-art high count rate observations covering all of the most crucial aspects of the source variability.

Asm-Triggered too Observations of 100,000 C/s Black Hole Candidates

NASA Astrophysics Data System (ADS)

van der Klis, Michiel

Resubmission accepted Cycle 2-8 proposal. - The PCA is unique by the high count rates (~100,000 c/s) it can record, and its resulting extreme sensitivity to weak variability. Only few sources get this bright. Our RXTE work on Sco X-1 and 1744-28 shows that high count rate observations are very rewarding, but also difficult and not without risk. In the life of the satellite probably only one black-hole transient (if any) will reach 10^5 c/s/5PCU levels. When this occurs, a window of discovery will be opened on black holes, which will nearly certainly close again within a few days. This proposal aims at ensuring that optimal use is made of this opportunity by performing state-of- the-art high count rate observations covering all of the most crucial aspects of the source variability.

Asm-Triggered too Observations of 100,000 C/s Black Hole Candidates

NASA Astrophysics Data System (ADS)

van der Klis, Michiel

Resubmission accepted Cycle 2-9 proposal. The PCA is unique by the high count rates (~100,000 c/s) it can record, and its resulting extreme sensitivity to weak variability. Only few sources get this bright. Our RXTE work on Sco X-1 and 1744-28 shows that high count rate observations are very rewarding, but also difficult and not without risk. In the life og the satallire probably only one black-hole transient (if any) will reach 10^5 cps/5PCU levels. when this occurs, a window of discovery will be opened on black holes, which will nearly certainly close again within a few days. This proposal aims at ensuring that optimal use is made of this opportunity by performing state of the art high count rate observations covering all of the most crucial aspects of the source variability.

Asm-Triggered too Observations of 100,000 C/s Black Hole Candidates

NASA Astrophysics Data System (ADS)

van der Klis, Michiel

Resubmission accepted Cycle 2-5 proposal. - The PCA is unique by the high count rates (~100,000 c/s) it can record, and its resulting extreme sensitivity to weak variability. Only few sources get this bright. Our RXTE work on Sco X-1 and 1744-28 shows that high count rate observations are very rewarding, but also difficult and not without risk. In the life of the satellite probably only one black-hole transient (if any) will reach 100,000 c/s levels. When this occurs, a window of discovery will be opened on black holes, which will nearly certainly close again within a few days. This proposal aims at ensuring that optimal use is made of this opportunity by performing state-of- the-art high count rate observations covering all of the most crucial aspects of the source variability.

Asm-Triggered too Observations of 100,000 C/s Black Hole Candidates

NASA Astrophysics Data System (ADS)

van der Klis, Michiel

Resubmission accepted Cycle 2&3 proposal. - The PCA is unique by the high count rates (~100,000 c/s) it can record, and its resulting extreme sensitivity to weak variability. Only few sources get this bright. Our Cycle 1-3 work on Sco X-1 and 1744-28 shows that high count rate observations are very rewarding, but also difficult and not without risk. In the life of the satellite probably only one black-hole transient (if any) will reach 100,000 c/s levels. When this occurs, a window of discovery will be opened on black holes, which will nearly certainly close again within a few days. This proposal aims at ensuring that optimal use is made of this opportunity by performing state-of- the-art high count rate observations covering all of the most crucial aspects of the source variability.

Asm-Triggered too Observations of 100,000 C/s Black Hole Candidates

NASA Astrophysics Data System (ADS)

van der Klis, Michiel

Resubmission accepted Cycle 2,3&4 proposal. - The PCA is unique by the high count rates (~100,000 c/s) it can record, and its resulting extreme sensitivity to weak variability. Only few sources get this bright. Our Cycle 1-3 work on Sco X-1 and 1744-28 shows that high count rate observations are very rewarding, but also difficult and not without risk. In the life of the satellite probably only one black-hole transient (if any) will reach 100,000 c/s levels. When this occurs, a window of discovery will be opened on black holes, which will nearly certainly close again within a few days. This proposal aims at ensuring that optimal use is made of this opportunity by performing state-of- the-art high count rate observations covering all of the most crucial aspects of the source variability.

Asm-Triggered too Observations of 100,000 C/s Black Hole Candidates

NASA Astrophysics Data System (ADS)

van der Klis, Michiel

RESUBMISSION ACCEPTED CYCLE 2 PROPOSAL - The PCA is unique by the high count rates (~100,000 c/s) it can record, and its resulting extreme sensitivity to weak variability. Only few sources get this bright. Our Cycle 1&2 work on Sco X-1 and 1744-28 has shown that high count rate observations are very rewarding, but also difficult and not without risk. In the life of the satellite probably only one black-hole transient (if any) will reach 100,000 c/s levels. When this occurs, a window of discovery will be opened on black holes, which will nearly certainly close again within a few days. This proposal aims at ensuring that optimal use is made of this opportunity by performing state-of- the-art high count rate observations covering all of the most crucial aspects of the source variability.

ASM Triggered too Observations of 100,000 C/s Black-Hole Candidates

NASA Astrophysics Data System (ADS)

van der Klis, Michiel

Resubmission accepted Cycle 2-10 proposal. The PCA is unique by the high count rates (~100.000 c/s) it can record, and its resulting extreme sensitivity to weak variability. Only few sources get this bright. Our RXTE work on Sco X-1 and 1744-28 shows that high count rate observations are very rewarding, but also difficult and not without risk. In the life of the satellite probably only one black hole transient (if any) will reach 10^5 cps/5 PCU levels. When this occurs a window of discovery will be opened on black holes, which will nearly certainly close again within a few days. This proposal aims at ensuring that optimal use is made of this opportunity by performing state of the art high count rate observations covering all of the most crusial aspects of the source variability.

ASM Triggered too Observations of 100,000 C/s Black-Hole Candidates (core Program)

NASA Astrophysics Data System (ADS)

Resubmission accepted Cycle 2-11 proposal. The PCA is unique by the high count rates (~100.000 c/s) it can record, and its resulting extreme sensitivity to weak variability. Only few sources get this bright. Our RXTE work on Sco X-1 and 1744-28 shows that high count rate observations are very rewarding, but also difficult and not without risk. In the life of the satellite probably only one black hole transient (if any) will reach 10^5 cps/5 PCU levels. When this occurs a window of discovery will be opened on black holes, which will nearly certainly close again within a few days. This proposal aims at ensuring that optimal use is made of this opportunity by performing state of the art high count rate observations covering all of the most crusial aspects of the source variability.

ASM Triggered too Observations of 100,000 C/s Black-Hole Candidates

NASA Astrophysics Data System (ADS)

van der Klis, Michiel

Resubmission accepted Cycle 2-11 proposal. The PCA is unique by the high count rates (~100.000 c/s) it can record, and its resulting extreme sensitivity to weak variability. Only few sources get this bright. Our RXTE work on Sco X-1 and 1744-28 shows that high count rate observations are very rewarding, but also difficult and not without risk. In the life of the satellite probably only one black hole transient (if any) will reach 10^5 cps/5 PCU levels. When this occurs a window of discovery will be opened on black holes, which will nearly certainly close again within a few days. This proposal aims at ensuring that optimal use is made of this opportunity by performing state of the art high count rate observations covering all of the most crusial aspects of the source variability.

Monte Carlo simulation of Ray-Scan 64 PET system and performance evaluation using GATE toolkit

NASA Astrophysics Data System (ADS)

Li, Suying; Zhang, Qiushi; Vuletic, Ivan; Xie, Zhaoheng; Yang, Kun; Ren, Qiushi

2017-02-01

In this study, we aimed to develop a GATE model for the simulation of Ray-Scan 64 PET scanner and model its performance characteristics. A detailed implementation of system geometry and physical process were included in the simulation model. Then we modeled the performance characteristics of Ray-Scan 64 PET system for the first time, based on National Electrical Manufacturers Association (NEMA) NU-2 2007 protocols and validated the model against experimental measurement, including spatial resolution, sensitivity, counting rates and noise equivalent count rate (NECR). Moreover, an accurate dead time module was investigated to simulate the counting rate performance. Overall results showed reasonable agreement between simulation and experimental data. The validation results showed the reliability and feasibility of the GATE model to evaluate major performance of Ray-Scan 64 PET system. It provided a useful tool for a wide range of research applications.

ACUTE CARDIOVASCULAR EFFECTS OF FIREFIGHTING AND ACTIVE COOLING DURING REHABILITATION

PubMed Central

Burgess, Jefferey L.; Duncan, Michael D.; Hu, Chengcheng; Littau, Sally R.; Caseman, Delayne; Kurzius-Spencer, Margaret; Davis-Gorman, Grace; McDonagh, Paul F.

2012-01-01

Objectives To determine the cardiovascular and hemostatic effects of fire suppression and post-exposure active cooling. Methods Forty-four firefighters were evaluated prior to and after a 12 minute live-fire drill. Next, 50 firefighters undergoing the same drill were randomized to post-fire forearm immersion in 10°C water or standard rehabilitation. Results In the first study, heart rate and core body temperature increased and serum C-reactive protein decreased but there were no significant changes in fibrinogen, sE-selectin or sL-selectin. The second study demonstrated an increase in blood coagulability, leukocyte count, factors VIII and X, cortisol and glucose, and a decrease in plasminogen and sP-selectin. Active cooling reduced mean core temperature, heart rate and leukocyte count. Conclusions Live-fire exposure increased core temperature, heart rate, coagulability and leukocyte count; all except coagulability were reduced by active cooling. PMID:23090161

Electronic Delivery System: Presentation Features.

DTIC Science & Technology

1981-04-01

THE INFOR’"TiO 1. 0 THE FULNCTIONALITY OF THE PRESENTATIO,’, NOT ITS REPLIC., NATURE IS WHAT COUNTS. S-12 REAL ISM _(CNTD. ) * A SEQUENCE OF...E.G, A MOUSE) IS USED FOR INPUTTINZ RESPONSES, THEY CAN BE VERY EFFICIENT, , S-21 -~i INTERACTION - MECHANISt, S (CONTD.) * TOUCH PANELS -- NATURAL , NO...INTERACTION - MECHANISMS (CONTD, i fm O VOICE INPUT --USED WHERE HANDS OR EYES ARE BUSY (E.G., FOR MAINTENANCE AIDING), -- A NATURAL MEANS OF CO;r UNICATION

Economic Analysis of Redesign Alternatives for the RESFMS Information System

DTIC Science & Technology

1992-09-01

input parameters to produce the variations of output ( Pressman , 1992). Thus, if system maintenance dictates that the procedure needs to be modified, it...easily counted, and that "a large body of literature and data predicated on LOC already exists." ( Pressman , 1992) Another term for LOC, used by Boehm... Pressman , 1992). 54 D. FUNCTION POINTS An alternative to size metrics such as LOC is the measurement of software "functionality" or "utility." Function

Intrinsic vs. extrinsic influences on life history expression: metabolism and parentally induced temperature influences on embryo development rate.

PubMed

Martin, Thomas E; Ton, Riccardo; Niklison, Alina

2013-06-01

Intrinsic processes are assumed to underlie life history expression and trade-offs, but extrinsic inputs are theorised to shift trait expression and mask trade-offs within species. Here, we explore application of this theory across species. We do this based on parentally induced embryo temperature as an extrinsic input, and mass-specific embryo metabolism as an intrinsic process, underlying embryonic development rate. We found that embryonic metabolism followed intrinsic allometry rules among 49 songbird species from temperate and tropical sites. Extrinsic inputs via parentally induced temperatures explained the majority of variation in development rates and masked a relationship with metabolism; metabolism explained a minor proportion of the variation in development rates among species, and only after accounting for temperature effects. We discuss evidence that temperature further obscures the expected interspecific trade-off between development rate and offspring quality. These results demonstrate the importance of considering extrinsic inputs to trait expression and trade-offs across species. © 2013 John Wiley & Sons Ltd/CNRS.

Dual Brushless Resolver Rate Sensor

NASA Technical Reports Server (NTRS)

Howard, David E. (Inventor)

1996-01-01

This invention relates to dual analog angular rate sensors which are implemented without the use of mechanical brushes. A resolver rate sensor which includes two brushless resolvers which are mechanically coupled to the same output shaft is provided with inputs which are provided to each resolver by providing the first resolver with a DC input and the second resolver with an AC sinusoidal input. A trigonometric identity in which the sum of the squares of the sin and cosine components equal one is used to advantage in providing a sensor of increased accuracy. The first resolver may have a fixed or variable DC input to permit dynamic adjustment of resolver sensitivity thus permitting a wide range of coverage. Novelty and advantages of the invention reside in the excitation of a resolver with a DC signal and in the utilization of two resolvers and the trigonometric identity of cos(exp 2)(theta) + sin(exp 2)(theta) = 1 to provide an accurate rate sensor which is sensitive to direction and accurate through zero rate.

Intrinsic vs. extrinsic influences on life history expression: metabolism and parentally induced temperature influences on embryo development rate

USGS Publications Warehouse

Martin, Thomas E.; Ton, Riccardo; Nikilson, Alina

2013-01-01

Intrinsic processes are assumed to underlie life history expression and trade-offs, but extrinsic inputs are theorised to shift trait expression and mask trade-offs within species. Here, we explore application of this theory across species. We do this based on parentally induced embryo temperature as an extrinsic input, and mass-specific embryo metabolism as an intrinsic process, underlying embryonic development rate. We found that embryonic metabolism followed intrinsic allometry rules among 49 songbird species from temperate and tropical sites. Extrinsic inputs via parentally induced temperatures explained the majority of variation in development rates and masked a relationship with metabolism; metabolism explained a minor proportion of the variation in development rates among species, and only after accounting for temperature effects. We discuss evidence that temperature further obscures the expected interspecific trade-off between development rate and offspring quality. These results demonstrate the importance of considering extrinsic inputs to trait expression and trade-offs across species.

An information-theoretic approach to motor action decoding with a reconfigurable parallel architecture.

PubMed

Craciun, Stefan; Brockmeier, Austin J; George, Alan D; Lam, Herman; Príncipe, José C

2011-01-01

Methods for decoding movements from neural spike counts using adaptive filters often rely on minimizing the mean-squared error. However, for non-Gaussian distribution of errors, this approach is not optimal for performance. Therefore, rather than using probabilistic modeling, we propose an alternate non-parametric approach. In order to extract more structure from the input signal (neuronal spike counts) we propose using minimum error entropy (MEE), an information-theoretic approach that minimizes the error entropy as part of an iterative cost function. However, the disadvantage of using MEE as the cost function for adaptive filters is the increase in computational complexity. In this paper we present a comparison between the decoding performance of the analytic Wiener filter and a linear filter trained with MEE, which is then mapped to a parallel architecture in reconfigurable hardware tailored to the computational needs of the MEE filter. We observe considerable speedup from the hardware design. The adaptation of filter weights for the multiple-input, multiple-output linear filters, necessary in motor decoding, is a highly parallelizable algorithm. It can be decomposed into many independent computational blocks with a parallel architecture readily mapped to a field-programmable gate array (FPGA) and scales to large numbers of neurons. By pipelining and parallelizing independent computations in the algorithm, the proposed parallel architecture has sublinear increases in execution time with respect to both window size and filter order.

Virological failure and development of new resistance mutations according to CD4 count at combination antiretroviral therapy initiation.

PubMed

Jose, S; Quinn, K; Dunn, D; Cox, A; Sabin, C; Fidler, S

2016-05-01

No randomized controlled trials have yet reported an individual patient benefit of initiating combination antiretroviral therapy (cART) at CD4 counts > 350 cells/μL. It is hypothesized that earlier initiation of cART in asymptomatic and otherwise healthy individuals may lead to poorer adherence and subsequently higher rates of resistance development. In a large cohort of HIV-positive individuals, we investigated the emergence of new resistance mutations upon virological treatment failure according to the CD4 count at the initiation of cART. Of 7918 included individuals, 6514 (82.3%), 996 (12.6%) and 408 (5.2%) started cART with a CD4 count ≤ 350, 351-499 and ≥ 500 cells/μL, respectively. Virological rebound occurred while on cART in 488 (7.5%), 46 (4.6%) and 30 (7.4%) with a baseline CD4 count ≤ 350, 351-499 and ≥ 500 cells/μL, respectively. Only four (13.0%) individuals with a baseline CD4 count > 350 cells/μL in receipt of a resistance test at viral load rebound were found to have developed new resistance mutations. This compared to 107 (41.2%) of those with virological failure who had initiated cART with a CD4 count < 350 cells/μL. We found no evidence of increased rates of resistance development when cART was initiated at CD4 counts above 350 cells/μL. © 2015 The Authors. HIV Medicine published by John Wiley & Sons Ltd on behalf of British HIV Association.

Trends in the Authorship of Peer Reviewed Publications in the Urology Literature.

PubMed

An, Julie Y; Baiocco, Joseph A; Rais-Bahrami, Soroush

2018-05-01

We evaluated the authorship count of all original research and review articles published in prominent Urology journals to trend patterns in authorship over the last decade. Secondarily, we evaluated bibliometric assessments and sought to understand whether authorship count was associated with citation rate and each article's field-normalized measure of impact. Information on authorship count, date of publication, study type, journal of publication, citation rate, and relative citation ratio (RCR) was collected for all original research and review articles published in European Urology, Journal of Urology, Urology , and British Journal of Urology International between 2006 and 2016. We examined trends in authorship count over the past decade, as well as between journals and article types. 21,336 articles were analyzed, of which 19,527 (91.5%) were original research and 1,809 (8.5%) were review articles. Overall, number of authors increased 46.1% from 2006 to 2016. Authorship counts in original research articles increased by an average of 2.45 per manuscript (43.3% increase) over the decade analyzed. More dramatically, authorship counts in review articles increased by an average of 3.14 per manuscript (92.6% increase). Articles with higher authorship counts were associated with more citations and greater RCR (r=0.13, p<0.001). There is a global trend towards more authors per article in urology publications-in both original research publications and review articles, and across each of the individual journals evaluated. An increase in author count has also been associated with increased citations and measures of article impact.

Measures of clustering and heterogeneity in multilevel Poisson regression analyses of rates/count data

PubMed Central

Austin, Peter C.; Stryhn, Henrik; Leckie, George; Merlo, Juan

2017-01-01

Multilevel data occur frequently in many research areas like health services research and epidemiology. A suitable way to analyze such data is through the use of multilevel regression models. These models incorporate cluster‐specific random effects that allow one to partition the total variation in the outcome into between‐cluster variation and between‐individual variation. The magnitude of the effect of clustering provides a measure of the general contextual effect. When outcomes are binary or time‐to‐event in nature, the general contextual effect can be quantified by measures of heterogeneity like the median odds ratio or the median hazard ratio, respectively, which can be calculated from a multilevel regression model. Outcomes that are integer counts denoting the number of times that an event occurred are common in epidemiological and medical research. The median (incidence) rate ratio in multilevel Poisson regression for counts that corresponds to the median odds ratio or median hazard ratio for binary or time‐to‐event outcomes respectively is relatively unknown and is rarely used. The median rate ratio is the median relative change in the rate of the occurrence of the event when comparing identical subjects from 2 randomly selected different clusters that are ordered by rate. We also describe how the variance partition coefficient, which denotes the proportion of the variation in the outcome that is attributable to between‐cluster differences, can be computed with count outcomes. We illustrate the application and interpretation of these measures in a case study analyzing the rate of hospital readmission in patients discharged from hospital with a diagnosis of heart failure. PMID:29114926

Heart rate and leukocytes after air and ground transportation in artificially ventilated neonates: a prospective observational study.

PubMed

Grosek, Stefan; Mlakar, Gorazd; Vidmar, Ivan; Ihan, Alojz; Primozic, Janez

2009-01-01

To evaluate the effect of interhospital air and ground transportation of artificially ventilated neonates on heart rate and peripheral blood leukocyte counts. Prospective, observational study. Level III multidisciplinary Neonatal and Pediatric Intensive Care Unit. Fifty-eight near-term artificially ventilated transported neonates between May 2006 and April 2007. Day-helicopter, day- and night-ground transportation. Heart rate at retrieval, on admission to the ICU and 1 h later, and peripheral blood leukocyte counts on admission and 1 d later were compared. Fifteen neonates were transported by helicopter during the daytime (D-HEL), 20 by daytime ground and 23 by nighttime ground transportation (D-GROUND, N-GROUND). No differences in delivery mode, birth weight, gestational age, gender, primary diagnoses for transportation, response time and duration of transportation were found between the groups. Similarly, no differences in pH, pCO(2), blood pressure and skin temperature at retrieval and on admission to the ICU were found between the three groups. The mean heart rate at retrieval did not differ significantly, while on arrival in the ICU and 1 h later the D-GROUND group of patients showed a significantly higher mean heart rate compared to the D-HEL and N-GROUND groups. Moreover, leukocyte counts on arrival in the ICU showed significantly higher leukocyte counts in the D-GROUND group of patients compared to the D-HEL group of patients. These results demonstrate that there is an association between daytime ground transportation and higher heart rate and peripheral blood leukocytes.

Effective count rates for PET scanners with reduced and extended axial field of view

NASA Astrophysics Data System (ADS)

MacDonald, L. R.; Harrison, R. L.; Alessio, A. M.; Hunter, W. C. J.; Lewellen, T. K.; Kinahan, P. E.

2011-06-01

We investigated the relationship between noise equivalent count (NEC) and axial field of view (AFOV) for PET scanners with AFOVs ranging from one-half to twice those of current clinical scanners. PET scanners with longer or shorter AFOVs could fulfill different clinical needs depending on exam volumes and site economics. Using previously validated Monte Carlo simulations, we modeled true, scattered and random coincidence counting rates for a PET ring diameter of 88 cm with 2, 4, 6, and 8 rings of detector blocks (AFOV 7.8, 15.5, 23.3, and 31.0 cm). Fully 3D acquisition mode was compared to full collimation (2D) and partial collimation (2.5D) modes. Counting rates were estimated for a 200 cm long version of the 20 cm diameter NEMA count-rate phantom and for an anthropomorphic object based on a patient scan. We estimated the live-time characteristics of the scanner from measured count-rate data and applied that estimate to the simulated results to obtain NEC as a function of object activity. We found NEC increased as a quadratic function of AFOV for 3D mode, and linearly in 2D mode. Partial collimation provided the highest overall NEC on the 2-block system and fully 3D mode provided the highest NEC on the 8-block system for clinically relevant activities. On the 4-, and 6-block systems 3D mode NEC was highest up to ~300 MBq in the anthropomorphic phantom, above which 3D NEC dropped rapidly, and 2.5D NEC was highest. Projected total scan time to achieve NEC-density that matches current clinical practice in a typical oncology exam averaged 9, 15, 24, and 61 min for the 8-, 6-, 4-, and 2-block ring systems, when using optimal collimation. Increasing the AFOV should provide a greater than proportional increase in NEC, potentially benefiting patient throughput-to-cost ratio. Conversely, by using appropriate collimation, a two-ring (7.8 cm AFOV) system could acquire whole-body scans achieving NEC-density levels comparable to current standards within long, but feasible, scan times.

Internalisation of microbes in vegetables: microbial load of Ghanaian vegetables and the relationship with different water sources of irrigation.

PubMed

Donkor, Eric S; Lanyo, R; Kayang, Boniface B; Quaye, Jonathan; Edoh, Dominic A

2010-09-01

The occurrence of pathogens in the internal parts of vegetables is usually associated with irrigation water or contaminated soil and could pose risk to consumers as the internalised pathogens are unaffected by external washing. This study was carried out to assess the rate of internalisation of microbes in common Ghanaian vegetables. Standard microbiological methods were employed in microbial enumeration of vegetables collected at the market and farm levels, as well as irrigation water and soil samples. The overall mean counts of vegetables were 4.0 x 10(3) cfu g(-1); 8.1 x 10(2) cfu g(-1); 2.0 x 10(2) cfu g(-1); 3.5 x 10(2) cfu g(-1) for total bacteria, coliform counts, faecal coliform counts and yeast counts, respectively. The rate of internalisation of coliforms in vegetables irrigated with stream/well water was 2.7 times higher than those irrigated with pipe water. The mean coliform counts (4.7 x 10(7) cfu g(-1)) and faecal coliform counts (1.8 x 10(6) cfu g(-1)) of soil samples were similar to those of stream water suggesting both sources exerted similar contamination rates on the vegetables. Generally, there were no significant variations between the rates of internalisation of microbes at the market and farm levels at p < 05, indicating that internalisation of microbes in the vegetables mainly occurred at the farm level. The study has shown that microbial contamination of vegetables in Ghana is not limited to the external surface, but internal vegetable parts could harbour high microbial loads and pose risk to consumers. Safety practices associated with the commodity should therefore not be limited to external washing only. There is the additional need of heating vegetables to eliminate microbes both externally and internally before consumption.

Using Enrollment Data to Predict Retention Rate

ERIC Educational Resources Information Center

Bingham, Melissa A.; Solverson, Natalie Walleser

2016-01-01

First- to second-year retention rates are one metric reported by colleges and universities to convey institutional success to a variety of external constituents. But how much of a retention rate is institutional inputs, and how much can be understood by examining student inputs? The authors utilize multi-year, multi-institutional data to examine…

High-rate x-ray spectroscopy in mammography with a CdTe detector: a digital pulse processing approach.

PubMed

Abbene, L; Gerardi, G; Principato, F; Del Sordo, S; Ienzi, R; Raso, G

2010-12-01

Direct measurement of mammographic x-ray spectra under clinical conditions is a difficult task due to the high fluence rate of the x-ray beams as well as the limits in the development of high resolution detection systems in a high counting rate environment. In this work we present a detection system, based on a CdTe detector and an innovative digital pulse processing (DPP) system, for high-rate x-ray spectroscopy in mammography. The DPP system performs a digital pile-up inspection and a digital pulse height analysis of the detector signals, digitized through a 14-bit, 100 MHz digitizer, for x-ray spectroscopy even at high photon counting rates. We investigated on the response of the digital detection system both at low (150 cps) and at high photon counting rates (up to 500 kcps) by using monoenergetic x-ray sources and a nonclinical molybdenum anode x-ray tube. Clinical molybdenum x-ray spectrum measurements were also performed by using a pinhole collimator and a custom alignment device. The detection system shows excellent performance up to 512 kcps with an energy resolution of 4.08% FWHM at 22.1 keV. Despite the high photon counting rate (up to 453 kcps), the molybdenum x-ray spectra, measured under clinical conditions, are characterized by a low number of pile-up events. The agreement between the attenuation curves and the half value layer values, obtained from the measured spectra, simulated spectra, and from the exposure values directly measured with an ionization chamber, also shows the accuracy of the measurements. These results make the proposed detection system a very attractive tool for both laboratory research and advanced quality controls in mammography.

Correlation of platelet count and acute ST-elevation in myocardial infarction.

PubMed

Paul, G K; Sen, B; Bari, M A; Rahman, Z; Jamal, F; Bari, M S; Sazidur, S R

2010-07-01

The role of platelets in the pathogenesis of ST-elevation myocardial infarction (STEMI) has been substantiated by studies that demonstrated significant clinical benefits associated with antiplatelet therapy. Initial platelet counts in Acute Myocardial Infarction (AMI) may be a useful adjunct for identifying those patients who may or may not respond to fibrinolytic agents. Patient with acute STEMI has variable level of platelet count and with higher platelet count have poor in hospital outcome. There are many predictors of poor outcome in Acute Myocardial Infarction (AMI) like cardiac biomarkers (Troponin I, Troponin T and CK-MB), C-Reactive Protien (CRP) and WBC (White Blood Cell) counts. Platelet count on presentation of STEMI is one of them. Higher platelet count is associated with higher rate of adverse clinical outcome in ST-Elevation Myocardial Infarction (STEMI), like heart failure, arrhythmia, re-infarction & death. So, categorization of patient with STEMI on the basis of platelet counts may be helpful for risk stratification and management of these patients.

[Main concepts of preventive health care for the air staff of sea-based aviation].

PubMed

Mel'nik, S G; Chulaevskiĭ, A O

2013-08-01

The authors researched the air-stuff and complex of adverse factors uncharacteristic for the air-staff of land-based aircraft. It was determined that adverse factors affect the air-staff foremost in 4-5 months of a blue-water sailing, except cardiovascular system diseases. In a month of a blue-water sailing was registered a hypotonic state. Systolic blood pressure varied from 100-105 mm Hg and lower, dystolic blood pressure varied from 60-65 mm Hg and lower. The lowest ranges of blood pressure were registered in three months after the beginning of the sailing. In the following, the hypotonic state, registered during the monthly medical examinations, remained till the end of the sailing. Normal averages of blood pressure were restored in two weeks after the end of sailing. Low red cell count (for more than 1100 points) was registered in 61.5% of patients, (for more than 550 points) in 38.4% of patients. Low white cell count (for more than 4800 points) was registered in 33.3% of patients, (for more than 3300 points) in 41% of patients, (for more than 1330 points) in 25% of patients. Input data was: red cell count--4250 points, white cell count--7300 points in 1 ml of blood. After the sailing haematological indices were restored. The authors suggested guidelines for primary and secondary disease prevention.

Low-Power, 8-Channel EEG Recorder and Seizure Detector ASIC for a Subdermal Implantable System.

PubMed

Do Valle, Bruno G; Cash, Sydney S; Sodini, Charles G

2016-12-01

EEG remains the mainstay test for the diagnosis and treatment of patients with epilepsy. Unfortunately, ambulatory EEG systems are far from ideal for patients who have infrequent seizures. These systems only last up to 3 days and if a seizure is not captured during the recordings, a definite diagnosis of the patient's condition cannot be given. This work aims to address this need by proposing a subdermal implantable, eight-channel EEG recorder and seizure detector that has two modes of operation: diagnosis and seizure counting. In the diagnosis mode, EEG is continuously recorded until a number of seizures are recorded. In the seizure counting mode, the system uses a low-power algorithm to track the number of seizures a patient has, providing doctors with a reliable count to help determine medication efficacy or other clinical endpoint. An ASIC that implements the EEG recording and seizure detection algorithm was designed and fabricated in a 0.18 μm CMOS process. The ASIC includes eight EEG channels and is designed to minimize the system's power and size. The result is a power-efficient analog front end that requires 2.75 μW per channel in diagnosis mode and 0.84 μW per channel in seizure counting mode. Both modes have an input referred noise of approximately 1.1 μVrms.

Mapping from multiple-control Toffoli circuits to linear nearest neighbor quantum circuits

NASA Astrophysics Data System (ADS)

Cheng, Xueyun; Guan, Zhijin; Ding, Weiping

2018-07-01

In recent years, quantum computing research has been attracting more and more attention, but few studies on the limited interaction distance between quantum bits (qubit) are deeply carried out. This paper presents a mapping method for transforming multiple-control Toffoli (MCT) circuits into linear nearest neighbor (LNN) quantum circuits instead of traditional decomposition-based methods. In order to reduce the number of inserted SWAP gates, a novel type of gate with the optimal LNN quantum realization was constructed, namely NNTS gate. The MCT gate with multiple control bits could be better cascaded by the NNTS gates, in which the arrangement of the input lines was LNN arrangement of the MCT gate. Then, the communication overhead measurement model on inserted SWAP gate count from the original arrangement to the new arrangement was put forward, and we selected one of the LNN arrangements with the minimum SWAP gate count. Moreover, the LNN arrangement-based mapping algorithm was given, and it dealt with the MCT gates in turn and mapped each MCT gate into its LNN form by inserting the minimum number of SWAP gates. Finally, some simplification rules were used, which can further reduce the final quantum cost of the LNN quantum circuit. Experiments on some benchmark MCT circuits indicate that the direct mapping algorithm results in fewer additional SWAP gates in about 50%, while the average improvement rate in quantum cost is 16.95% compared to the decomposition-based method. In addition, it has been verified that the proposed method has greater superiority for reversible circuits cascaded by MCT gates with more control bits.

Validation of a Monte Carlo simulation of the Philips Allegro/GEMINI PET systems using GATE

NASA Astrophysics Data System (ADS)

Lamare, F.; Turzo, A.; Bizais, Y.; Cheze LeRest, C.; Visvikis, D.

2006-02-01

A newly developed simulation toolkit, GATE (Geant4 Application for Tomographic Emission), was used to develop a Monte Carlo simulation of a fully three-dimensional (3D) clinical PET scanner. The Philips Allegro/GEMINI PET systems were simulated in order to (a) allow a detailed study of the parameters affecting the system's performance under various imaging conditions, (b) study the optimization and quantitative accuracy of emission acquisition protocols for dynamic and static imaging, and (c) further validate the potential of GATE for the simulation of clinical PET systems. A model of the detection system and its geometry was developed. The accuracy of the developed detection model was tested through the comparison of simulated and measured results obtained with the Allegro/GEMINI systems for a number of NEMA NU2-2001 performance protocols including spatial resolution, sensitivity and scatter fraction. In addition, an approximate model of the system's dead time at the level of detected single events and coincidences was developed in an attempt to simulate the count rate related performance characteristics of the scanner. The developed dead-time model was assessed under different imaging conditions using the count rate loss and noise equivalent count rates performance protocols of standard and modified NEMA NU2-2001 (whole body imaging conditions) and NEMA NU2-1994 (brain imaging conditions) comparing simulated with experimental measurements obtained with the Allegro/GEMINI PET systems. Finally, a reconstructed image quality protocol was used to assess the overall performance of the developed model. An agreement of <3% was obtained in scatter fraction, with a difference between 4% and 10% in the true and random coincidence count rates respectively, throughout a range of activity concentrations and under various imaging conditions, resulting in <8% differences between simulated and measured noise equivalent count rates performance. Finally, the image quality validation study revealed a good agreement in signal-to-noise ratio and contrast recovery coefficients for a number of different volume spheres and two different (clinical level based) tumour-to-background ratios. In conclusion, these results support the accurate modelling of the Philips Allegro/GEMINI PET systems using GATE in combination with a dead-time model for the signal flow description, which leads to an agreement of <10% in coincidence count rates under different imaging conditions and clinically relevant activity concentration levels.

The role of size of input box, location of input box, input method and display size in Chinese handwriting performance and preference on mobile devices.

PubMed

Chen, Zhe; Rau, Pei-Luen Patrick

2017-03-01

This study presented two experiments on Chinese handwriting performance (time, accuracy, the number of protruding strokes and number of rewritings) and subjective ratings (mental workload, satisfaction, and preference) on mobile devices. Experiment 1 evaluated the effects of size of the input box, input method and display size on Chinese handwriting performance and preference. It was indicated that the optimal input sizes were 30.8 × 30.8 mm, 46.6 × 46.6 mm, 58.9 × 58.9 mm and 84.6 × 84.6 mm for devices with 3.5-inch, 5.5-inch, 7.0-inch and 9.7-inch display sizes, respectively. Experiment 2 proved the significant effects of location of the input box, input method and display size on Chinese handwriting performance and subjective ratings. It was suggested that the optimal location was central regardless of display size and input method. Copyright © 2016 Elsevier Ltd. All rights reserved.

P2 and behavioral effects of stroke count in Chinese characters: Evidence for an analytic and attentional view.

PubMed

Yang, Shasha; Zhang, Shunmei; Wang, Quanhong

2016-08-15

The inconsistent stroke-count effect in Chinese character recognition has resulted in an intense debate between the analytic and holistic views of character processing. The length effects of English words on behavioral responses and event-related potentials (ERPs) are similarly inconclusive. In this study, we identified any behavioral and ERP stroke-count effects when orthographic neighborhood sizes are balanced across three stroke counts. A delayed character-matching task was conducted while ERPs were recorded. The behavioral data indicated that both response latency and error rate increased with increasing stroke count. The ERP data showed higher P2 but lower N2 amplitudes in the large count than in the median count condition. A higher P2 can reflect increased attentional load and reduced attentional resource for processing each stroke because of the additional strokes in the large count condition. The behavioral and ERP effects of stroke count provide evidence for the analytic view of character processing but also provide evidence against the holistic view. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Improving the counting efficiency in time-correlated single photon counting experiments by dead-time optimization

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

Peronio, P.; Acconcia, G.; Rech, I.

Time-Correlated Single Photon Counting (TCSPC) has been long recognized as the most sensitive method for fluorescence lifetime measurements, but often requiring “long” data acquisition times. This drawback is related to the limited counting capability of the TCSPC technique, due to pile-up and counting loss effects. In recent years, multi-module TCSPC systems have been introduced to overcome this issue. Splitting the light into several detectors connected to independent TCSPC modules proportionally increases the counting capability. Of course, multi-module operation also increases the system cost and can cause space and power supply problems. In this paper, we propose an alternative approach basedmore » on a new detector and processing electronics designed to reduce the overall system dead time, thus enabling efficient photon collection at high excitation rate. We present a fast active quenching circuit for single-photon avalanche diodes which features a minimum dead time of 12.4 ns. We also introduce a new Time-to-Amplitude Converter (TAC) able to attain extra-short dead time thanks to the combination of a scalable array of monolithically integrated TACs and a sequential router. The fast TAC (F-TAC) makes it possible to operate the system towards the upper limit of detector count rate capability (∼80 Mcps) with reduced pile-up losses, addressing one of the historic criticisms of TCSPC. Preliminary measurements on the F-TAC are presented and discussed.« less

Association of asymptomatic oral candidal carriage, oral candidiasis and CD4 lymphocyte count in HIV-positive patients in China.

PubMed

Liu, X; Liu, H; Guo, Z; Luan, W

2006-01-01

To compare the prevalence of asymptomatic oral candidal carriage in healthy volunteers with human immunodeficiency virus (HIV)-positive patients in China, as well as to investigate the relationship between CD4+ lymphocyte count and oral candidal colonization or oral candidiasis. Oral candidal carriage and oral candidiasis were investigated in 101 patients with HIV-infection seen at Youan Hospital, Beijing, China. Two hundred and seventeen healthy volunteers were involved as a control. Culture from saliva was used to test for the presence of oral Candida. CD4+ lymphocyte count was measured by flow cytometry. All data were analyzed statistically by SAS. Asymptomatic oral candidal carriage rate (28.6%) in HIV-positive group was similar to that in the healthy group (18.0%; P = 0.07). No significant difference in CD4+ lymphocyte count was found between oral Candida carriers and non-carriers among HIV-positive subjects (P = 0.89). However, the frequency of oral candidiasis increased with the decrease in CD4+ lymphocyte count (P < 0.0001), and pseudomembranous candidiasis was predominant in HIV-positive patients with CD4+ <200 cells microl(-1) (66.7%). In HIV-positive subjects, asymptomatic oral candidal colonization is not related to CD4+ lymphocyte count of blood, and the carriage rate is similar to that in the healthy population. Oral candidiasis is more likely to be observed in HIV-positive patients who have a low CD4+ lymphocyte count.

Evaluation of Pulse Counting for the Mars Organic Mass Analyzer (MOMA) Ion Trap Detection Scheme

NASA Technical Reports Server (NTRS)

Van Amerom, Friso H.; Short, Tim; Brinckerhoff, William; Mahaffy, Paul; Kleyner, Igor; Cotter, Robert J.; Pinnick, Veronica; Hoffman, Lars; Danell, Ryan M.; Lyness, Eric I.

2011-01-01

The Mars Organic Mass Analyzer is being developed at Goddard Space Flight Center to identify organics and possible biological compounds on Mars. In the process of characterizing mass spectrometer size, weight, and power consumption, the use of pulse counting was considered for ion detection. Pulse counting has advantages over analog-mode amplification of the electron multiplier signal. Some advantages are reduced size of electronic components, low power consumption, ability to remotely characterize detector performance, and avoidance of analog circuit noise. The use of pulse counting as a detection method with ion trap instruments is relatively rare. However, with the recent development of high performance electrical components, this detection method is quite suitable and can demonstrate significant advantages over analog methods. Methods A prototype quadrupole ion trap mass spectrometer with an internal electron ionization source was used as a test setup to develop and evaluate the pulse-counting method. The anode signal from the electron multiplier was preamplified. The an1plified signal was fed into a fast comparator for pulse-level discrimination. The output of the comparator was fed directly into a Xilinx FPGA development board. Verilog HDL software was written to bin the counts at user-selectable intervals. This system was able to count pulses at rates in the GHz range. The stored ion count nun1ber per bin was transferred to custom ion trap control software. Pulse-counting mass spectra were compared with mass spectra obtained using the standard analog-mode ion detection. Prelin1inary Data Preliminary mass spectra have been obtained for both analog mode and pulse-counting mode under several sets of instrument operating conditions. Comparison of the spectra revealed better peak shapes for pulse-counting mode. Noise levels are as good as, or better than, analog-mode detection noise levels. To artificially force ion pile-up conditions, the ion trap was overfilled and ions were ejected at very high scan rates. Pile-up of ions was not significant for the ion trap under investigation even though the ions are ejected in so-called 'ion-micro packets'. It was found that pulse counting mode had higher dynamic range than analog mode, and that the first amplification stage in analog mode can distort mass peaks. The inherent speed of the pulse counting method also proved to be beneficial to ion trap operation and ion ejection characterization. Very high scan rates were possible with pulse counting since the digital circuitry response time is so much smaller than with the analog method. Careful investigation of the pulse-counting data also allowed observation of the applied resonant ejection frequency during mass analysis. Ejection of ion micro packets could be clearly observed in the binned data. A second oscillation frequency, much lower than the secular frequency, was also observed. Such an effect was earlier attributed to the oscillation of the total plasma cloud in the ion trap. While the components used to implement pulse counting are quite advanced, due to their prevalence in consumer electronics, the cost of this detection system is no more than that of an analog mode system. Total pulse-counting detection system electronics cost is under $250

2007 Michigan traffic crash facts

DOT National Transportation Integrated Search

2008-03-08

The 2007 traffic fatality count was 1,084, identical to the 2006 count. Compared with 2006, : injuries were down 1.7 percent, while total crashes increased 2.8 percent. These figures : translated into a death rate of 1.04 per 100 million miles of tra...

X-ray detection of Nova Del 2013 with Swift

NASA Astrophysics Data System (ADS)

Castro-Tirado, Alberto J.; Martin-Carrillo, Antonio; Hanlon, Lorraine

2013-08-01

Continuous X-ray monitoring by Swift of Nova Del 2013 (see CBET #3628) shows an increase of X-ray emission at the source location compared to previous observations (ATEL #5283, ATEL #5305) during a 3.9 ksec observation at UT 2013-08-22 12:05. With the XRT instrument operating in window timing mode, 744 counts were extracted from a 50 pixel long source region and 324 counts from a similar box for a background region, resulting in a 13-sigma detection with a net count rate of 0.11±0.008 counts/sec.

Background characterization of an ultra-low background liquid scintillation counter

DOE PAGES

Erchinger, J. L.; Orrell, John L.; Aalseth, C. E.; ...

2017-01-26

The Ultra-Low Background Liquid Scintillation Counter developed by Pacific Northwest National Laboratory will expand the application of liquid scintillation counting by enabling lower detection limits and smaller sample volumes. By reducing the overall count rate of the background environment approximately 2 orders of magnitude below that of commercially available systems, backgrounds on the order of tens of counts per day over an energy range of ~3–3600 keV can be realized. Finally, initial test results of the ULB LSC show promising results for ultra-low background detection with liquid scintillation counting.

Negative Avalanche Feedback Detectors for Photon-Counting Optical Communications

NASA Technical Reports Server (NTRS)

Farr, William H.

2009-01-01

Negative Avalanche Feedback photon counting detectors with near-infrared spectral sensitivity offer an alternative to conventional Geiger mode avalanche photodiode or phototube detectors for free space communications links at 1 and 1.55 microns. These devices demonstrate linear mode photon counting without requiring any external reset circuitry and may even be operated at room temperature. We have now characterized the detection efficiency, dark count rate, after-pulsing, and single photon jitter for three variants of this new detector class, as well as operated these uniquely simple to use devices in actual photon starved free space optical communications links.