Science.gov

Sample records for 1-hour time point

  1. [Analysis on prevalence of physical activity time <1 hour and related factors in students aged 9-22 years in China, 2014].

    PubMed

    Wang, Z H; Dong, Y H; Song, Y; Yang, Z P; Ma, J

    2017-03-10

    Objective: To explore the prevalence of physical activity time <1 hour and related factors in students aged 9-22 years in China. Methods: A total of 220 159 students (110 039 boys and 110 120 girls) aged 9-22 years who completed the questionnaire of physical activity and lifestyle behaviors were selected from " 2014 National Physical Fitness and Health Surveillance" for the current study. All the participants were divided into 2 groups, i.e. physical activity time <1 hour and physical activity time1 hour according the suggestion of Central Government, stratified by age and gender. χ(2) tests were used to compare the difference in the prevalence of physical activity time <1 hour between boys and girls in every age groups. Univariate and multivariate log-binomial regression models were used to explore the factors that influenced the prevalence of physical activity time <1 hour. Results: The boy's prevalence of physical activity time <1 hour was 73.3%, with the lowest (57.0%) in 9-years-old group, and highest (82.5%) in 18 years old group. The girl's prevalence of physical activity time <1 hour was 79.1%, with the lowest (60.1%) in 9-years-old group, and highest (89.8%) in 21 years old group. Overall, The prevalence of physical activity time <1 hour was significantly higher in girls than in boys (P<0.001), and the prevalence were significantly higher in girls than in boys in all the age groups (P<0.001), and it was observed that the prevalence of physical activity <1 hour increased with age in both boys and girls (P<0.001). Multivariate log-binomial regression model found that being girl (PR=1.05, 95%CI: 1.05-1.06), parents' disliking children to participate physical activity (PR=1.08, 95% CI: 1.07-1.09), heavy homework (PR=1.13, 95% CI: 1.12-1.14), long homework time (PR =1.08, 95%CI: 1.07-1.08), long time spending on electronic screen watching (PR=1.01, 95%CI: 1.00-1.01) and disliking physical class (PR=1.11, 95%CI: 1.10-1.12) could be the risk factors for

  2. 40 CFR 60.1755 - How do I convert my 1-hour arithmetic averages into appropriate averaging times and units?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...-hour arithmetic averages into appropriate averaging times and units? (a) Use the equation in § 60.1935.... If you are monitoring the percent reduction of sulfur dioxide, use EPA Reference Method 19 in... Reference Method 19 in appendix A of this part, section 4.1, to calculate the daily arithmetic average...

  3. 40 CFR 60.1755 - How do I convert my 1-hour arithmetic averages into appropriate averaging times and units?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... part, section 4.3, to calculate the daily geometric average concentrations of sulfur dioxide emissions... potential sulfur dioxide emissions. (c) If you operate a Class I municipal waste combustion unit, use EPA... SOURCES Emission Guidelines and Compliance Times for Small Municipal Waste Combustion Units Constructed...

  4. 40 CFR 60.1265 - How do I convert my 1-hour arithmetic averages into the appropriate averaging times and units?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... geometric average concentrations of sulfur dioxide emissions. If you are monitoring the percent reduction of... daily geometric average percent reduction of potential sulfur dioxide emissions. (c) If you operate a... Continuous Emission Monitoring § 60.1265 How do I convert my 1-hour arithmetic averages into the...

  5. 40 CFR 60.1265 - How do I convert my 1-hour arithmetic averages into the appropriate averaging times and units?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... averages into the appropriate averaging times and units? 60.1265 Section 60.1265 Protection of Environment... averaging times and units? (a) Use the equation in § 60.1460(a) to calculate emissions at 7 percent oxygen. (b) Use EPA Reference Method 19 in appendix A of this part, section 4.3, to calculate the...

  6. 40 CFR 60.2943 - How do I convert my 1-hour arithmetic averages into the appropriate averaging times and units?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... averages into the appropriate averaging times and units? (a) Use Equation 1 in § 60.2975 to calculate emissions at 7 percent oxygen. (b) Use Equation 2 in § 60.2975 to calculate the 12-hour rolling averages...

  7. 40 CFR 60.3042 - How do I convert my 1-hour arithmetic averages into the appropriate averaging times and units?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... arithmetic averages into the appropriate averaging times and units? (a) Use Equation 1 in § 60.3076 to calculate emissions at 7 percent oxygen. (b) Use Equation 2 in § 60.3076 to calculate the 12-hour...

  8. Early Time Points Perfusion Imaging

    PubMed Central

    Kwong, Kenneth K.; Reese, Timothy G.; Nelissen, Koen; Wu, Ona; Chan, Suk-Tak; Benner, Thomas; Mandeville, Joseph B.; Foley, Mary; Vanduffel, Wim; Chesler, David A.

    2010-01-01

    The aim was to investigate the feasibility of making relative cerebral blood flow (rCBF) maps from MR images acquired with short TR by measuring the initial arrival amount of Gd-DTPA evaluated within a time window before any contrast agent has a chance to leave the tissue. We named this rCBF measurement technique utilizing the early data points of the Gd-DTPA bolus the “early time points” method (ET), based on the hypothesis that early time point signals were proportional to rCBF. Simulation data were used successfully to examine the ideal behavior of ET while monkey’s MRI results offered encouraging support to the utility of ET for rCBF calculation. A better brain coverage for ET could be obtained by applying the Simultaneous Echo Refocusing (SER) EPI technique. A recipe to run ET was presented, with attention paid to the noise problem around the time of arrival (TOA) of the contrast agent. PMID:20851196

  9. 40 CFR 51.905 - How do areas transition from the 1-hour NAAQS to the 1997 8-hour NAAQS and what are the anti...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... met its obligation to have a fully-approved attainment demonstration SIP for the 1-hour NAAQS, the... SIP at the time of the effective date of designation and in addition to national or regional measures... obligation for an approved 1-hour ROP SIP, it must develop and submit to EPA all outstanding 1-hour ROP...

  10. MINOS Timing and GPS Precise Point Positioning

    DTIC Science & Technology

    2012-01-01

    Minos Timing Spec • Neutrinos created in bunches separated by 19 ns • ~ 1 neutrino /day detected in Soudan Mine – 2 milliseconds travel time...Must know which bunch created the observed neutrino • Bunches are about 6 ns wide – To become 3.5 ns wide after planned upgrade in 2013

  11. Arctic tipping points: governance in turbulent times.

    PubMed

    Young, Oran R

    2012-02-01

    Interacting forces of climate change and globalization are transforming the Arctic. Triggered by a non-linear shift in sea ice, this transformation has unleashed mounting interest in opportunities to exploit the region's natural resources as well as growing concern about environmental, economic, and political issues associated with such efforts. This article addresses the implications of this transformation for governance, identifies limitations of existing arrangements, and explores changes needed to meet new demands. It advocates the development of an Arctic regime complex featuring flexibility across issues and adaptability over time along with an enhanced role for the Arctic Council both in conducting policy-relevant assessments and in promoting synergy in interactions among the elements of the emerging Arctic regime complex. The emphasis throughout is on maximizing the fit between the socioecological features of the Arctic and the character of the governance arrangements needed to steer the Arctic toward a sustainable future.

  12. 76 FR 28661 - Interim Final Determination To Defer Sanctions, Sacramento Metro 1-Hour Ozone Nonattainment Area...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-18

    ... AGENCY 40 CFR Part 52 Interim Final Determination To Defer Sanctions, Sacramento Metro 1-Hour Ozone... the Sacramento Metro 1- hour Ozone nonattainment area (Sacramento Metro Area) to satisfy anti- backsliding requirements for the 1-hour Ozone standard. DATES: This interim final determination is...

  13. Searching for periodicity in weighted time point series.

    NASA Astrophysics Data System (ADS)

    Jetsu, L.; Pelt, J.

    1996-09-01

    Consistent statistics for two methods of searching for periodicity in a series of weighted time points are formulated. An approach based on the bootstrap method to estimate the accuracy of detected periodicity is presented.

  14. Time optimal robotic manipulator motions and work places for point to point tasks

    NASA Technical Reports Server (NTRS)

    Dubowsky, S.; Blubaugh, T. D.

    1985-01-01

    High productivity requires that manipulators perform complex tasks quickly. Recently, optimal control algorithms have been developed which enable manipulators to move quickly, but only for simple motions. A method is presented here which combines simple time optimal motions in an optimal manner to yield the minimum time motions for an important class of complex manipulator tasks composed of point to point moves, such as assembly, electronic component insertion and spot welding. This method can also be used to design manipulator actions and work places so that tasks can be completd in minimum time. The method has been implemented in a CAD software package. Examples are presented which show the methods effectiveness.

  15. Planning time-optimal robotic manipulator motions and work places for point-to-point tasks

    NASA Technical Reports Server (NTRS)

    Dubowsky, S.; Blubaugh, T. D.

    1989-01-01

    A method is presented which combines simple time-optimal motions in an optimal manner to yield the minimum-time motions for an important class of complex manipulator tasks composed of point-to-point moves such as assembly, electronic component insertion, and spot welding. This method can also be used to design manipulator actions and work places so that tasks can be completed in minimum time. The method has been implemented in a computer-aided design software system. Several examples are presented. Experimental results show the method's validity and utility.

  16. Supporting One-Time Point Annotations for Gesture Recognition.

    PubMed

    Nguyen-Dinh, Long-Van; Calatroni, Alberto; Troester, Gerhard

    2016-12-08

    This paper investigates a new annotation technique that reduces significantly the amount of time to annotate training data for gesture recognition. Conventionally, the annotations comprise the start and end times, and the corresponding labels of gestures in sensor recordings. In this work, we propose a one-time point annotation in which labelers do not have to select the start and end time carefully, but just mark a one-time point within the time a gesture is happening. The technique gives more freedom and reduces significantly the burden for labelers. To make the one-time point annotations applicable, we propose a novel BoundarySearch algorithm to find automatically the correct temporal boundaries of gestures by discovering data patterns around their given one-time point annotations. The corrected annotations are then used to train gesture models. We evaluate the method on three applications from wearable gesture recognition with various gesture classes (10-17 classes) recorded with different sensor modalities. The results show that training on the corrected annotations can achieve performances close to a fully supervised training on clean annotations (lower by just up to 5% F1-score on average). Furthermore, the BoundarySearch algorithm is also evaluated on the ChaLearn 2014 multi-modal gesture recognition challenge recorded with Kinect sensors from computer vision and achieves similar results.

  17. Parametric time delay modeling for floating point units

    NASA Astrophysics Data System (ADS)

    Fahmy, Hossam A. H.; Liddicoat, Albert A.; Flynn, Michael J.

    2002-12-01

    A parametric time delay model to compare floating point unit implementations is proposed. This model is used to compare a previously proposed floating point adder using a redundant number representation with other high-performance implementations. The operand width, the fan-in of the logic gates and the radix of the redundant format are used as parameters to the model. The comparison is done over a range of operand widths, fan-in and radices to show the merits of each implementation.

  18. Return times at periodic points in random dynamics

    NASA Astrophysics Data System (ADS)

    Haydn, Nicolai; Todd, Mike

    2017-01-01

    We prove a quenched limiting law for random measures on subshifts at periodic points. We consider a family of measures {≤ft\\{{{μω}\\right\\}}ω \\in Ω } , where the ‘driving space’ Ω is equipped with a probability measure which is invariant under a transformation θ. We assume that the fibred measures {μω} satisfy a generalised invariance property and are ψ-mixing. We then show that for almost every ω the return times to cylinders A n at periodic points are in the limit compound Poisson distributed for a parameter ϑ which is given by the escape rate at the periodic point.

  19. Accessing the exceptional points of parity-time symmetric acoustics

    PubMed Central

    Shi, Chengzhi; Dubois, Marc; Chen, Yun; Cheng, Lei; Ramezani, Hamidreza; Wang, Yuan; Zhang, Xiang

    2016-01-01

    Parity-time (PT) symmetric systems experience phase transition between PT exact and broken phases at exceptional point. These PT phase transitions contribute significantly to the design of single mode lasers, coherent perfect absorbers, isolators, and diodes. However, such exceptional points are extremely difficult to access in practice because of the dispersive behaviour of most loss and gain materials required in PT symmetric systems. Here we introduce a method to systematically tame these exceptional points and control PT phases. Our experimental demonstration hinges on an active acoustic element that realizes a complex-valued potential and simultaneously controls the multiple interference in the structure. The manipulation of exceptional points offers new routes to broaden applications for PT symmetric physics in acoustics, optics, microwaves and electronics, which are essential for sensing, communication and imaging. PMID:27025443

  20. Guidance for 1-Hour Sulfur Dioxide (SO2) Nonattainment Area State Implementation Plans (SIP) Submissions

    EPA Pesticide Factsheets

    The document is intended to provide guidance and recommendations to state, local and tribal governments for the development of SIPs and tribal implementation plans (TIPs) under the 2010 1-hour primary NAAQS for Sulfur Dioxide (SO2).

  1. The timing of control signals underlying fast point-to-point arm movements.

    PubMed

    Ghafouri, M; Feldman, A G

    2001-04-01

    It is known that proprioceptive feedback induces muscle activation when the facilitation of appropriate motoneurons exceeds their threshold. In the suprathreshold range, the muscle-reflex system produces torques depending on the position and velocity of the joint segment(s) that the muscle spans. The static component of the torque-position relationship is referred to as the invariant characteristic (IC). According to the equilibrium-point (EP) hypothesis, control systems produce movements by changing the activation thresholds and thus shifting the IC of the appropriate muscles in joint space. This control process upsets the balance between muscle and external torques at the initial limb configuration and, to regain the balance, the limb is forced to establish a new configuration or, if the movement is prevented, a new level of static torques. Taken together, the joint angles and the muscle torques generated at an equilibrium configuration define a single variable called the EP. Thus by shifting the IC, control systems reset the EP. Muscle activation and movement emerge following the EP resetting because of the natural physical tendency of the system to reach equilibrium. Empirical and simulation studies support the notion that the control IC shifts and the resulting EP shifts underlying fast point-to-point arm movements are gradual rather than step-like. However, controversies exist about the duration of these shifts. Some studies suggest that the IC shifts cease with the movement offset. Other studies propose that the IC shifts end early in comparison to the movement duration (approximately, at peak velocity). The purpose of this study was to evaluate the duration of the IC shifts underlying fast point-to-point arm movements. Subjects made fast (hand peak velocity about 1.3 m/s) planar arm movements toward different targets while grasping a handle. Hand forces applied to the handle and shoulder/elbow torques were, respectively, measured from a force sensor placed

  2. Taming the Exceptional Points of Parity-Time Symmetric Acoustics

    NASA Astrophysics Data System (ADS)

    Dubois, Marc; Shi, Chengzhi; Chen, Yun; Cheng, Lei; Ramezani, Hamidreza; Wang, Yuan; Zhang, Xiang

    Parity-time (PT) symmetric concept and development lead to a wide range of applications including coherent perfect absorbers, single mode lasers, unidirectional cloaking and sensing, and optical isolators. These new applications and devices emerge from the existence of a phase transition in PT symmetric complex-valued potential obtained by balancing gain and loss materials. However, the systematic extension of such devices is adjourned by the key challenge in the management of the complex scattering process within the structure in order to engineer PT phase and exceptional points. Here, based on active acoustic elements, we experimentally demonstrate the simultaneous control of complex-valued potentials and multiple interference inside the structure at any given frequency. This method broadens the scope of applications for PT symmetric devices in many fields including optics, microwaves, electronics, which are crucial for sensing, imaging, cloaking, lasing, absorbing, etc.

  3. Pixel timing correction in time-lapsed calcium imaging using point scanning microscopy.

    PubMed

    Boiroux, Dimitri; Oke, Yoshihiko; Miwakeichi, Fumikazu; Oku, Yoshitaka

    2014-11-30

    In point scanning imaging, data are acquired by sequentially scanning each pixel of a predetermined area. This way of scanning leads to time delays between pixels, especially for lower scanning speed or large scanned areas. Therefore, experiments are often performed at lower framerates in order to ensure a sufficient signal-to-noise ratio, even though framerates above 30 frames per second are technically feasible. For these framerates, we suggest that it becomes crucial to correct the time delay between image pixels prior to analyses. In this paper, we apply temporal interpolation (or pixel timing correction) for calcium imaging in two-photon microscopy as an example of fluorescence imaging. We present and compare three interpolation methods (linear, Lanczos and cubic B-spline). We test these methods on a simulated network of coupled bursting neurons at different framerates. In this network, we introduce a time delay to simulate a scanning by point scanning microscopy. We also assess these methods on actual microscopic calcium imaging movies recorded at usual framerates. Our numerical results suggest that point scanning microscopy imaging introduces statistically significant time delays between image pixels at low frequency. However, we demonstrate that pixel timing correction compensates for these time delays, regardless of the used interpolation method.

  4. GOES Infrared and Reflectance 0-1 hour Lightning Initiation Indicators: Development and Initial Testing within a Convective Nowcasting System

    NASA Astrophysics Data System (ADS)

    Mecikalski, J. R.; Harris, R.; MacKenzie, W.; Durkee, P. A.; Iskenderian, H.; Bickmeier, L.; Nielsen, K. E.

    2010-12-01

    Within cumulus cloud fields that develop in conditionally unstable air masses, only a fraction of the cumuli may eventually develop into deep convection. Identifying which of these convective clouds most likely to generate lightning often starts with little more than a qualitative visual satellite analysis. The goal of this study is to identify the observed satellite infrared (IR) signatures associated with growing cumulus clouds prior to the first lightning strike, so-called lightning initiation (LI). This study quantifies the behavior of ten Geostationary Operational Environmental Satellite (GOES-12) IR interest fields in the 1-hour in advance of LI. A total of 172 lightning-producing storms that occurred during the 2009 convective season are manually tracked and studied over four regions: Northern Alabama, Central Oklahoma, the Kennedy Space Center and Washington D.C. Four-dimensional and cloud-to-ground lightning array data provide a total cloud lightning picture (in-cloud, cloud-to-cloud, cloud-to-air, cloud-to-ground) and thus precise LI points for each storm in both time and space. Statistical significance tests are conducted on observed trends for each of the ten LI fields to determine the unique information each field provides in terms of behavior prior to LI. Eight out of ten LI fields exhibited useful information at least 15 min in advance of LI, with 35 min being the average. Statistical tests on these eight fields are compared for separate large geographical areas. IR temperature thresholds are then determined as an outcome, which may be valuable when implementing a LI prediction algorithm into real-time satellite-based systems. The key LI indicators from GOES IR data (as well as 3.9 μm reflectance) will be presented. Beginning in 2010, the feasibility of using the satellite-based LI indicators found in the above analysis to forecast first lightning will be assessed within the Federal Aviation Administration’s (FAA) CoSPA nowcasting system. The goal

  5. Aerosolized Red Tide Toxins (Brevetoxins) and Asthma: Continued health effects after 1 hour beach exposure.

    PubMed

    Kirkpatrick, Barbara; Fleming, Lora E; Bean, Judy A; Nierenberg, Kate; Backer, Lorraine C; Cheng, Yung Sung; Pierce, Richard; Reich, Andrew; Naar, Jerome; Wanner, Adam; Abraham, William M; Zhou, Yue; Hollenbeck, Julie; Baden, Daniel G

    2011-01-01

    Blooms of the toxic dinoflagellate, Karenia brevis, produce potent neurotoxins in marine aerosols. Recent studies have demonstrated acute changes in both symptoms and pulmonary function in asthmatics after only 1 hour of beach exposure to these aerosols. This study investigated if there were latent and/or sustained effects in asthmatics in the days following the initial beach exposure during periods with and without an active Florida red tide.Symptom data and spirometry data were collected before and after 1 hour of beach exposure. Subjects kept daily symptom diaries and measured their peak flow each morning for 5 days following beach exposure. During non-exposure periods, there were no significant changes in symptoms or pulmonary function either acutely or over 5 days of follow-up. After the beach exposure during an active Florida red tide, subjects had elevated mean symptoms which did not return to the pre-exposure baseline for at least 4 days. The peak flow measurements decreased after the initial beach exposure, decreased further within 24 hours, and continued to be suppressed even after 5 days. Asthmatics may continue to have increased symptoms and delayed respiratory function suppression for several days after 1 hour of exposure to the Florida red tide toxin aerosols.

  6. Improved Magnetic STAR Methods for Real-Time, Point-by-Point Localization of Unexploded Ordnance and Buried Mines

    DTIC Science & Technology

    2008-09-01

    portable STAR Gradiometer was designed and constructed at NSWC PCD to provide a completely portable and user-friendly technology for real-time DLC...r-values between the target and the respective CT-measurement points. Thus, if CT is measured at multiple points within a STAR gradiometer array...geometrical design of the gradiometer . b) The triangulation baselines, their respective end-point CT values and (3) can be used in a STAR Algorithm

  7. Cumulative time statistics of surface-point rainfall rates

    NASA Technical Reports Server (NTRS)

    Rice, P. L.; Holmberg, N. R.

    1973-01-01

    Statistics on rainfall rates near and above the earth's surface are needed in order to estimate the percentage of time of absorption, or scattering of radio waves that affect radio system design and electrospace management. The most useful averaging time for computing such rates is on the order of 1 min or less. This paper extrapolates excessive short-duration precipitation data to provide such statistics from data routinely reported by the National Weather Service. For the 8766 h in an average year, and for a median or random location in any part of the world, the model described here estimates the fraction of time during which t-minute average rainfall rates exceed any given value.

  8. 77 FR 4940 - Determination of Failure To Attain by 2005 and Determination of Current Attainment of the 1-Hour...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-01

    .... EPA, 375 F.3d 537(7th Cir. 2004) and Our Children's Earth Foundation v. EPA, No. 04-73032 (9thCir... monitored attainment of the 1-hour ozone NAAQS. EPA's review shows that the area has attained the 1-hour..., Associate Director, Office of Air Program Planning, Mailcode 3AP30, U.S. Environmental Protection...

  9. 40 CFR 50.9 - National 1-hour primary and secondary ambient air quality standards for ozone.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... ambient air quality standards for ozone. 50.9 Section 50.9 Protection of Environment ENVIRONMENTAL....9 National 1-hour primary and secondary ambient air quality standards for ozone. (a) The level of the national 1-hour primary and secondary ambient air quality standards for ozone measured by...

  10. 40 CFR 50.9 - National 1-hour primary and secondary ambient air quality standards for ozone.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... ambient air quality standards for ozone. 50.9 Section 50.9 Protection of Environment ENVIRONMENTAL....9 National 1-hour primary and secondary ambient air quality standards for ozone. (a) The level of the national 1-hour primary and secondary ambient air quality standards for ozone measured by...

  11. 40 CFR 50.9 - National 1-hour primary and secondary ambient air quality standards for ozone.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... ambient air quality standards for ozone. 50.9 Section 50.9 Protection of Environment ENVIRONMENTAL....9 National 1-hour primary and secondary ambient air quality standards for ozone. (a) The level of the national 1-hour primary and secondary ambient air quality standards for ozone measured by...

  12. 40 CFR 50.9 - National 1-hour primary and secondary ambient air quality standards for ozone.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... ambient air quality standards for ozone. 50.9 Section 50.9 Protection of Environment ENVIRONMENTAL....9 National 1-hour primary and secondary ambient air quality standards for ozone. (a) The level of the national 1-hour primary and secondary ambient air quality standards for ozone measured by...

  13. 40 CFR 50.9 - National 1-hour primary and secondary ambient air quality standards for ozone.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... ambient air quality standards for ozone. 50.9 Section 50.9 Protection of Environment ENVIRONMENTAL....9 National 1-hour primary and secondary ambient air quality standards for ozone. (a) The level of the national 1-hour primary and secondary ambient air quality standards for ozone measured by...

  14. Setting Spacecraft Maximum Allowable Concentrations for 1 hour or 24 hour contingency exposures to airborne chemicals

    NASA Technical Reports Server (NTRS)

    Garcia, Hector D.; Limero, Thomas F.; James, John T.

    1992-01-01

    Since the early years of the manned space program, NASA has developed and used exposure limits called Spacecraft Maximum Allowable Concentrations (SMACs) to help protect astronauts from airborne toxicants. Most of these SMACS are based on an exposure duration of 7 days, since this is the duration of a 'typical' mission. A set of 'contingency SMACs' is also being developed for scenarios involving brief (1-hour or 24- hour) exposures to relatively high levels of airborne toxicants from event-related 'contingency' releases of contaminants. The emergency nature of contingency exposures dictates the use of different criteria for setting exposure limits. The NASA JSC Toxicology Group recently began a program to document the rationales used to set new SMACs and plans to review the older, 7-day SMACs. In cooperation with the National Research Council's Committee on Toxicology, a standard procedure has been developed for researching, setting, and documenting SMAC values.

  15. MAPT and PAICE: Tools for time series and single time point transcriptionist visualization and knowledge discovery

    PubMed Central

    Hosseini, Parsa; Tremblay, Arianne; Matthews, Benjamin F; Alkharouf, Nadim W

    2012-01-01

    With the advent of next-generation sequencing, -omics fields such as transcriptomics have experienced increases in data throughput on the order of magnitudes. In terms of analyzing and visually representing these huge datasets, an intuitive and computationally tractable approach is to map quantified transcript expression onto biochemical pathways while employing datamining and visualization principles to accelerate knowledge discovery. We present two cross-platform tools: MAPT (Mapping and Analysis of Pathways through Time) and PAICE (Pathway Analysis and Integrated Coloring of Experiments), an easy to use analysis suite to facilitate time series and single time point transcriptomics analysis. In unison, MAPT and PAICE serve as a visual workbench for transcriptomics knowledge discovery, data-mining and functional annotation. Both PAICE and MAPT are two distinct but yet inextricably linked tools. The former is specifically designed to map EC accessions onto KEGG pathways while handling multiple gene copies, detection-call analysis, as well as UN/annotated EC accessions lacking quantifiable expression. The latter tool integrates PAICE datasets to drive visualization, annotation, and data-mining. Availability The database is available for free at http://sourceforge.net/projects/paice/http://sourceforge.net/projects/mapt/ PMID:22493539

  16. Bifurcated method and apparatus for floating point addition with decreased latency time

    DOEpatents

    Farmwald, Paul M.

    1987-01-01

    Apparatus for decreasing the latency time associated with floating point addition and subtraction in a computer, using a novel bifurcated, pre-normalization/post-normalization approach that distinguishes between differences of floating point exponents.

  17. LiDAR-IMU Time Delay Calibration Based on Iterative Closest Point and Iterated Sigma Point Kalman Filter.

    PubMed

    Liu, Wanli

    2017-03-08

    The time delay calibration between Light Detection and Ranging (LiDAR) and Inertial Measurement Units (IMUs) is an essential prerequisite for its applications. However, the correspondences between LiDAR and IMU measurements are usually unknown, and thus cannot be computed directly for the time delay calibration. In order to solve the problem of LiDAR-IMU time delay calibration, this paper presents a fusion method based on iterative closest point (ICP) and iterated sigma point Kalman filter (ISPKF), which combines the advantages of ICP and ISPKF. The ICP algorithm can precisely determine the unknown transformation between LiDAR-IMU; and the ISPKF algorithm can optimally estimate the time delay calibration parameters. First of all, the coordinate transformation from the LiDAR frame to the IMU frame is realized. Second, the measurement model and time delay error model of LiDAR and IMU are established. Third, the methodology of the ICP and ISPKF procedure is presented for LiDAR-IMU time delay calibration. Experimental results are presented that validate the proposed method and demonstrate the time delay error can be accurately calibrated.

  18. LiDAR-IMU Time Delay Calibration Based on Iterative Closest Point and Iterated Sigma Point Kalman Filter

    PubMed Central

    Liu, Wanli

    2017-01-01

    The time delay calibration between Light Detection and Ranging (LiDAR) and Inertial Measurement Units (IMUs) is an essential prerequisite for its applications. However, the correspondences between LiDAR and IMU measurements are usually unknown, and thus cannot be computed directly for the time delay calibration. In order to solve the problem of LiDAR-IMU time delay calibration, this paper presents a fusion method based on iterative closest point (ICP) and iterated sigma point Kalman filter (ISPKF), which combines the advantages of ICP and ISPKF. The ICP algorithm can precisely determine the unknown transformation between LiDAR-IMU; and the ISPKF algorithm can optimally estimate the time delay calibration parameters. First of all, the coordinate transformation from the LiDAR frame to the IMU frame is realized. Second, the measurement model and time delay error model of LiDAR and IMU are established. Third, the methodology of the ICP and ISPKF procedure is presented for LiDAR-IMU time delay calibration. Experimental results are presented that validate the proposed method and demonstrate the time delay error can be accurately calibrated. PMID:28282897

  19. Fixed-point vs. floating-point arithmetic comparison for adaptive optics real-time control computation

    NASA Astrophysics Data System (ADS)

    Martín-Hernando, Yolanda; Rodríguez-Ramos, Luis F.; Garcia-Talavera, Marcos R.

    2008-07-01

    Most computers in the past have been equipped with floating point processing capabilities, allowing an easy and brute-force solution for the machine computation errors, not requiring any specific tailoring of the computation in nearly hundred percent of situations. However, the computation needed for the adaptive optics real-time control in 30-50 meter telescopes is big enough to cause trouble to conventional von-Neumann processors, even if Moore's Law is valid for the next years. Field Programmable Gate Array (FPGAs) have been proposed as a viable alternative to cope with such computation needs[1,2], but--at least today's chips--will require fixed-point arithmetic to be used instead. It is then important to evaluate up to what point the accuracy and stability of the control system will be affected by this limitation. This paper presents the simulation and laboratory results of the comparison between both arithmetics, specifically evaluated in an adaptive optics system. The real-time controller has been modeled as black box having as input the wavefront sensor camera digital output data, providing a digital output to the actuators of the deformable mirror, and with the task of internally computing all outputs from the inputs. MATLAB fixed-point library has been used to evaluate the effect of different precision lengths (5-10 fractional bits) in the computation of the Shack-Hartmann subaperture centroid, in comparison with the reference 64-bit floating-point arithmetic and with the noise floor of the real system, concluding that the effect of the limited precision can be overcome by adequately selecting the number of fractional bits used in the representation, and tailoring that number with the needs at every step of the algorithm.

  20. Detecting shifts in gene regulatory networks during time-course experiments at single-time-point temporal resolution.

    PubMed

    Takenaka, Yoichi; Seno, Shigeto; Matsuda, Hideo

    2015-10-01

    Comprehensively understanding the dynamics of biological systems is one of the greatest challenges in biology. Vastly improved biological technologies have provided vast amounts of information that must be understood by bioinformatics and systems biology researchers. Gene regulations have been frequently modeled by ordinary differential equations or graphical models based on time-course gene expression profiles. The state-of-the-art computational approaches for analyzing gene regulations assume that their models are same throughout time-course experiments. However, these approaches cannot easily analyze transient changes at a time point, such as diauxic shift. We propose a score that analyzes the gene regulations at each time point. The score is based on the information gains of information criterion values. The method detects the shifts in gene regulatory networks (GRNs) during time-course experiments with single-time-point resolution. The effectiveness of the method is evaluated on the diauxic shift from glucose to lactose in Escherichia coli. Gene regulation shifts were detected at two time points: the first corresponding to the time at which the growth of E. coli ceased and the second corresponding to the end of the experiment, when the nutrient sources (glucose and lactose) had become exhausted. According to these results, the proposed score and method can appropriately detect the time of gene regulation shifts. The method based on the proposed score provides a new tool for analyzing dynamic biological systems. Because the score value indicates the strength of gene regulation at each time point in a gene expression profile, it can potentially infer hidden GRNs from time-course experiments.

  1. 77 FR 34810 - Determination of Failure To Attain by 2005 and Determination of Current Attainment of the 1-Hour...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-12

    .... 2004); and Our Children's Earth Foundation v. EPA, No. 04-73032 (9th Cir. June 28, 2005) (memorandum... attaining the revoked 1-hour ozone standard since 2008. EPA's determination that the area has attained the 1... inspection during normal business hours at the Air Protection Division, U.S. Environmental Protection...

  2. 75 FR 232 - Finding of Failure To Submit Certain State Implementation Plans Required for the 1-Hour Ozone NAAQS

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-05

    ... Ozone NAAQS AGENCY: Environmental Protection Agency (EPA). ACTION: Final rule. SUMMARY: The EPA is... Implementation Plans (SIPs) for three ozone nonattainment areas to satisfy certain requirements of the Clean Air Act (CAA) for the 1-hour ozone National Ambient Air Quality Standards (NAAQS). To accompany...

  3. Statistical analysis and multi-instrument overview of the quasi-periodic 1-hour pulsations in Saturn's outer magnetosphere

    NASA Astrophysics Data System (ADS)

    Palmaerts, B.; Roussos, E.; Krupp, N.; Kurth, W. S.; Mitchell, D. G.; Yates, J. N.

    2016-06-01

    The in-situ exploration of the magnetospheres of Jupiter and Saturn has revealed different periodic processes. In particular, in the Saturnian magnetosphere, several studies have reported pulsations in the outer magnetosphere with a periodicity of about 1 h in the measurements of charged particle fluxes, plasma wave, magnetic field strength and auroral emissions brightness. The Low-Energy Magnetospheric Measurement System detector of the Magnetospheric Imaging Instrument (MIMI/LEMMS) on board Cassini regularly detects 1-hour quasi-periodic enhancements in the intensities of electrons with an energy range from a hundred keV to several MeV. We extend an earlier survey of these relativistic electron injections using 10 years of LEMMS observations in addition to context measurements by several other Cassini magnetospheric experiments. The one-year extension of the data and a different method of detection of the injections do not lead to a discrepancy with the results of the previous survey, indicating an absence of a long-term temporal evolution of this phenomenon. We identified 720 pulsed events in the outer magnetosphere over a wide range of latitudes and local times, revealing that this phenomenon is common and frequent in Saturn's magnetosphere. However, the distribution of the injection events presents a strong local time asymmetry with ten times more events in the duskside than in the dawnside. In addition to the study of their topology, we present a first statistical analysis of the pulsed events properties. The morphology of the pulsations shows a weak local time dependence which could imply a high-latitude acceleration source. We provide some clues that the electron population associated with this pulsed phenomenon is distinct from the field-aligned electron beams previously observed in Saturn's magnetosphere, but both populations can be mixed. We have also investigated the signatures of each electron injection event in the observations acquired by the Radio

  4. Kick-Off, Half-Time, and Over-Time: Flexible Scheduling Scores Points

    ERIC Educational Resources Information Center

    McLeod, Jade

    2005-01-01

    When faculty members at Furman Middle School in Sumter, South Carolina, expressed concern about the lack of time in each day to provide the interventions, remediation, and enrichment the students needed to be prepared for state testing, their principal devised a creative flexible schedule to meet student needs. These include: (1) a morning…

  5. Knee Point Search Using Cascading Top-k Sorting with Minimized Time Complexity

    PubMed Central

    Tseng, Shian-Shyong

    2013-01-01

    Anomaly detection systems and many other applications are frequently confronted with the problem of finding the largest knee point in the sorted curve for a set of unsorted points. This paper proposes an efficient knee point search algorithm with minimized time complexity using the cascading top-k sorting when a priori probability distribution of the knee point is known. First, a top-k sort algorithm is proposed based on a quicksort variation. We divide the knee point search problem into multiple steps. And in each step an optimization problem of the selection number k is solved, where the objective function is defined as the expected time cost. Because the expected time cost in one step is dependent on that of the afterwards steps, we simplify the optimization problem by minimizing the maximum expected time cost. The posterior probability of the largest knee point distribution and the other parameters are updated before solving the optimization problem in each step. An example of source detection of DNS DoS flooding attacks is provided to illustrate the applications of the proposed algorithm. PMID:24068888

  6. A Well-Clear Volume Based on Time to Entry Point

    NASA Technical Reports Server (NTRS)

    Narkawicz, Anthony J.; Munoz, Cesar A.; Upchurch, Jason M.; Chamberlain, James P.; Consiglio, Maria C.

    2014-01-01

    A well-clear volume is a key component of NASA's Separation Assurance concept for the integration of UAS in the NAS. This paper proposes a mathematical definition of the well-clear volume that uses, in addition to distance thresholds, a time threshold based on time to entry point (TEP). The mathematical model that results from this definition is more conservative than other candidate definitions of the wellclear volume that are based on range over closure rate and time to closest point of approach.

  7. Anomalous parity-time-symmetry transition away from an exceptional point

    NASA Astrophysics Data System (ADS)

    Ge, Li

    2016-07-01

    Parity-time (PT ) symmetric systems have two distinguished phases, e.g., one with real-energy eigenvalues and the other with complex-conjugate eigenvalues. To enter one phase from the other, it is believed that the system must pass through an exceptional point, which is a non-Hermitian degenerate point with coalesced eigenvalues and eigenvectors. Here we reveal an anomalous PT transition that takes place away from an exceptional point in a nonlinear system: as the nonlinearity increases, the original linear system evolves along two distinct PT -symmetric trajectories, each of which can have an exceptional point. However, the two trajectories collide and vanish away from these exceptional points, after which the system is left with a PT -broken phase. We first illustrate this phenomenon using a coupled-mode theory and then exemplify it using paraxial wave propagation in a transverse periodic potential.

  8. Selecting the most appropriate time points to profile in high-throughput studies

    PubMed Central

    Kleyman, Michael; Sefer, Emre; Nicola, Teodora; Espinoza, Celia; Chhabra, Divya; Hagood, James S; Kaminski, Naftali; Ambalavanan, Namasivayam; Bar-Joseph, Ziv

    2017-01-01

    Biological systems are increasingly being studied by high throughput profiling of molecular data over time. Determining the set of time points to sample in studies that profile several different types of molecular data is still challenging. Here we present the Time Point Selection (TPS) method that solves this combinatorial problem in a principled and practical way. TPS utilizes expression data from a small set of genes sampled at a high rate. As we show by applying TPS to study mouse lung development, the points selected by TPS can be used to reconstruct an accurate representation for the expression values of the non selected points. Further, even though the selection is only based on gene expression, these points are also appropriate for representing a much larger set of protein, miRNA and DNA methylation changes over time. TPS can thus serve as a key design strategy for high throughput time series experiments. Supporting Website: www.sb.cs.cmu.edu/TPS DOI: http://dx.doi.org/10.7554/eLife.18541.001 PMID:28124972

  9. 40 CFR 60.1755 - How do I convert my 1-hour arithmetic averages into appropriate averaging times and units?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... or Before August 30, 1999 Model Rule-Continuous Emission Monitoring § 60.1755 How do I convert my 1.... If you are monitoring the percent reduction of sulfur dioxide, use EPA Reference Method 19 in appendix A of this part, section 5.4, to determine the daily geometric average percent reduction...

  10. 40 CFR 62.15210 - How do I convert my 1-hour arithmetic averages into appropriate averaging times and units?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... dioxide emissions. If you are monitoring the percent reduction of sulfur dioxide, use EPA Reference Method... dioxide emissions. (c) If you operate a Class I municipal waste combustion unit, use EPA Reference Method... Combustion Units Constructed on or Before August 30, 1999 Continuous Emission Monitoring § 62.15210 How do...

  11. 40 CFR 62.15210 - How do I convert my 1-hour arithmetic averages into appropriate averaging times and units?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... dioxide emissions. If you are monitoring the percent reduction of sulfur dioxide, use EPA Reference Method... dioxide emissions. (c) If you operate a Class I municipal waste combustion unit, use EPA Reference Method... Combustion Units Constructed on or Before August 30, 1999 Continuous Emission Monitoring § 62.15210 How do...

  12. Robust Optimization of Fixed Points of Nonlinear Discrete Time Systems with Uncertain Parameters

    NASA Astrophysics Data System (ADS)

    Kastsian, Darya; Monnigmann, Martin

    2010-01-01

    This contribution extends the normal vector method for the optimization of parametrically uncertain dynamical systems to a general class of nonlinear discrete time systems. Essentially, normal vectors are used to state constraints on dynamical properties of fixed points in the optimization of discrete time dynamical systems. In a typical application of the method, a technical dynamical system is optimized with respect to an economic profit function, while the normal vector constraints are used to guarantee the stability of the optimal fixed point. We derive normal vector systems for flip, fold, and Neimark-Sacker bifurcation points, because these bifurcation points constitute the stability boundary of a large class of discrete time systems. In addition, we derive normal vector systems for a related type of critical point that can be used to ensure a user-specified disturbance rejection rate in the optimization of parametrically uncertain systems. We illustrate the method by applying it to the optimization of a discrete time supply chain model and a discretized fermentation process model.

  13. An Integrated 0-1 Hour First-Flash Lightning Nowcasting, Lightning Amount and Lightning Jump Warning Capability

    NASA Technical Reports Server (NTRS)

    Mecikalski, John; Jewett, Chris; Carey, Larry; Zavodsky, Brad; Stano, Geoffrey

    2015-01-01

    Lightning one of the most dangerous weather-related phenomena, especially as many jobs and activities occur outdoors, presenting risk from a lightning strike. Cloud-to-ground (CG) lightning represents a considerable safety threat to people at airfields, marinas, and outdoor facilities-from airfield personnel, to people attending outdoor stadium events, on beaches and golf courses, to mariners, as well as emergency personnel. Holle et al. (2005) show that 90% of lightning deaths occurred outdoors, while 10% occurred indoors despite the perception of safety when inside buildings. Curran et al. (2000) found that nearly half of fatalities due to weather were related to convective weather in the 1992-1994 timeframe, with lightning causing a large component of the fatalities, in addition to tornadoes and flash flooding. Related to the aviation industry, CG lightning represents a considerable hazard to baggage-handlers, aircraft refuelers, food caterers, and emergency personnel, who all become exposed to the risk of being struck within short time periods while convective storm clouds develop. Airport safety protocols require that ramp operations be modified or discontinued when lightning is in the vicinity (typically 16 km), which becomes very costly and disruptive to flight operations. Therefore, much focus has been paid to nowcasting the first-time initiation and extent of lightning, both of CG and of any lightning (e.g, in-cloud, cloud-to-cloud). For this project three lightning nowcasting methodologies will be combined: (1) a GOESbased 0-1 hour lightning initiation (LI) product (Harris et al. 2010; Iskenderian et al. 2012), (2) a High Resolution Rapid Refresh (HRRR) lightning probability and forecasted lightning flash density product, such that a quantitative amount of lightning (QL) can be assigned to a location of expected LI, and (3) an algorithm that relates Pseudo-GLM data (Stano et al. 2012, 2014) to the so-called "lightning jump" (LJ) methodology (Shultz et al

  14. Electroencephalogram (EEG) duration needed to detect abnormalities in angelman syndrome: is 1 hour of overnight recording sufficient?

    PubMed

    Robinson, Althea A; Goldman, Suzanne; Barnes, Gregory; Goodpaster, Luke; Malow, Beth A

    2015-01-01

    Approximately, 90% of patients with Angelman syndrome present with epileptic seizures. Obtaining an electroencephalogram (EEG) with sleep improves the chances of detecting ictal, interictal, and benign abnormal rhythms in Angelman syndrome. However, electroencephalograms, even when obtained during sleep, can be challenging in this population because of tactile sensitivities as well as anxiety related to a novel environment. We tested the hypothesis that 1 hour of sleep on an electroencephalogram would provide as much information as an entire night of electroencephalogram recording, yet more than a routine electroencephalogram conducted during the day. Overnight polysomnograms were collected in 14 children with Angelman syndrome seen at Vanderbilt University. All patients who obtained sleep within the first hour of the overnight electroencephalogram had interictal discharges recorded. Our results show that when sleep is obtained, a 1-hour electroencephalogram yields just as much information as recording an entire night.

  15. A proxy method for real-time 3-DOF haptic rendering of streaming point cloud data.

    PubMed

    Rydén, Fredrik; Chizeck, Howard Jay

    2013-01-01

    This paper presents a new haptic rendering method for streaming point cloud data. It provides haptic rendering of moving physical objects using data obtained from RGB-D cameras. Thus, real-time haptic interaction with moving objects can be achieved using noncontact sensors. This method extends "virtual coupling"-based proxy methods in a way that does not require preprocessing of points and allows for spatial point cloud discontinuities. The key ideas of the algorithm are iterative motion of the proxy with respect to the points, and the use of a variable proxy step size that results in better accuracy for short proxy movements and faster convergence for longer movements. This method provides highly accurate haptic interaction for geometries in which the proxy can physically fit. Another advantage is a significant reduction in the risk of "pop through" during haptic interaction with dynamic point clouds, even in the presence of noise. This haptic rendering method is computationally efficient; it can run in real time on available personal computers without the need for downsampling of point clouds from commercially available depth cameras.

  16. Electrical stimulation of embryonic neurons for 1 hour improves axon regeneration and the number of reinnervated muscles that function.

    PubMed

    Liu, Yang; Grumbles, Robert M; Thomas, Christine K

    2013-07-01

    Motoneuron death after spinal cord injury or disease results in muscle denervation, atrophy, and paralysis. We have previously transplanted embryonic ventral spinal cord cells into the peripheral nerve to reinnervate denervated muscles and to reduce muscle atrophy, but reinnervation was incomplete. Here, our aim was to determine whether brief electrical stimulation of embryonic neurons in the peripheralnerve changes motoneuron survival, axon regeneration, and muscle reinnervation and function because neural depolarization is crucial for embryonic neuron survival and may promote activity-dependent axon growth. At 1 week after denervation by sciatic nerve section, embryonic day 14 to 15 cells were purified for motoneurons, injected into the tibial nerve of adult Fischer rats, and stimulated immediatelyfor up to 1 hour. More myelinated axons were present in tibial nerves 10 weeks after transplantation when transplants had been stimulated acutely at 1 Hz for 1 hour. More muscles were reinnervated if the stimulation treatment lasted for 1 hour. Reinnervation reduced muscle atrophy, with or without the stimulation treatment. These data suggest that brief stimulation of embryonic neurons promotes axon growth, which has a long-term impact on muscle reinnervation and function. Muscle reinnervation is important because it may enable the use of functional electrical stimulation to restore limb movements.

  17. Electrical Stimulation of Embryonic Neurons for 1 Hour Improves Axon Regeneration and the Number of Reinnervated Muscles that Function

    PubMed Central

    Liu, Yang; Grumbles, Robert M.; Thomas, Christine K.

    2013-01-01

    Motoneuron death following spinal cord injury or disease results in muscle denervation, atrophy, and paralysis. We have previously transplanted embryonic ventral spinal cord cells into peripheral nerve to reinnervate denervated muscles and to reduce muscle atrophy, but reinnervation was incomplete. Here, our aim was to determine whether brief electrical stimulation of embryonic neurons in peripheral nerve changes motoneuron survival, axon regeneration, and muscle reinnervation and function because neural depolarization is crucial for embryonic neuron survival and may promote activity-dependent axon growth. At 1 week after denervation by sciatic nerve section, embryonic day 14-15 cells were purified for motoneurons, injected into the tibial nerve of adult Fischer rats, and stimulated immediately for up to 1 hour. More myelinated axons were present in tibial nerves when transplants had been stimulated at 1 Hz for 1 hour at 10 weeks following transplantation. More muscles were reinnervated if the stimulation treatment lasted for 1 hour. Reinnervation reduced muscle atrophy, with or without the stimulation treatment. These data suggest that brief stimulation of embryonic neurons promotes axon growth, which has a long-term impact on muscle reinnervation and function. Muscle reinnervation is important because it may enable the use of functional electrical stimulation to restore limb movements. PMID:23771218

  18. Two-point time-series measurementsof hydroxyl concentration in a turbulent nonpremixed flame.

    PubMed

    Zhang, Jiayao; King, Galen B; Laurendeau, Normand M; Renfro, Michael W

    2007-08-10

    Quantitative two-point hydroxyl time-series measurements have been performed in a turbulent nonpremixed flame by using two-point picosecond time-resolved laser-induced fluorescence. The current diagnostic system has been improved from its preliminary version to address optical aberrations and fluorescence lifetime fluctuations. In particular, with a newly designed collection system, the aberration-limited blur spot is reduced from 6 mm to 180 microm. Additional photon-counting channels enable the recovery of absolute OH concentrations through a triple-bin integration method. The present research represents what we believe to be the first application of this two-point technique to turbulent flames. Two independent schemes have been applied to remove uncorrelated noise in the derived two-point statistics. We show that optical aberrations can have a significant effect on space-time correlations. However, the sampling rate and fluctuations in the fluorescence lifetime barely affect the spatial autocorrelation function and thus the integral length scale. Such length scales for hydroxyl are found to rise linearly with increasing axial distance at peak [OH] locations. Along the jet centerline, the integral length scale varies slightly below the flame tip but increases rapidly above the flame tip. In addition, the OH length scale demonstrates the same trend as the OH time scale along the jet centerline, but the opposite trend at peak [OH] locations.

  19. Portable Dew Point Mass Spectrometry System for Real-Time Gas and Moisture Analysis

    NASA Technical Reports Server (NTRS)

    Arkin, C.; Gillespie, Stacey; Ratzel, Christopher

    2010-01-01

    A portable instrument incorporates both mass spectrometry and dew point measurement to provide real-time, quantitative gas measurements of helium, nitrogen, oxygen, argon, and carbon dioxide, along with real-time, quantitative moisture analysis. The Portable Dew Point Mass Spectrometry (PDP-MS) system comprises a single quadrupole mass spectrometer and a high vacuum system consisting of a turbopump and a diaphragm-backing pump. A capacitive membrane dew point sensor was placed upstream of the MS, but still within the pressure-flow control pneumatic region. Pressure-flow control was achieved with an upstream precision metering valve, a capacitance diaphragm gauge, and a downstream mass flow controller. User configurable LabVIEW software was developed to provide real-time concentration data for the MS, dew point monitor, and sample delivery system pressure control, pressure and flow monitoring, and recording. The system has been designed to include in situ, NIST-traceable calibration. Certain sample tubing retains sufficient water that even if the sample is dry, the sample tube will desorb water to an amount resulting in moisture concentration errors up to 500 ppm for as long as 10 minutes. It was determined that Bev-A-Line IV was the best sample line to use. As a result of this issue, it is prudent to add a high-level humidity sensor to PDP-MS so such events can be prevented in the future.

  20. Time-point and dosage of gene inactivation determine the tumor spectrum in conditional Ptch knockouts.

    PubMed

    Zibat, Arne; Uhmann, Anja; Nitzki, Frauke; Wijgerde, Mark; Frommhold, Anke; Heller, Tanja; Armstrong, Victor; Wojnowski, Leszek; Quintanilla-Martinez, Leticia; Reifenberger, Julia; Schulz-Schaeffer, Walter; Hahn, Heidi

    2009-06-01

    Mutations in Patched (PTCH) have been associated with tumors characteristic both for children [medulloblastoma (MB) and rhabdomyosarcoma (RMS)] and for elderly [basal cell carcinoma (BCC)]. The determinants of the variability in tumor onset and histology are unknown. We investigated the effects of the time-point and dosage of Ptch inactivation on tumor spectrum using conditional Ptch-knockout mice. Ptch heterozygosity induced prenatally resulted in the formation of RMS, which was accompanied by the silencing of the remaining wild-type Ptch allele. In contrast, RMS was observed neither after mono- nor biallelic postnatal deletion of Ptch. Postnatal biallelic deletion of Ptch led to BCC precancerous lesions of the gastrointestinal epithelium and mesenteric tumors. Hamartomatous gastrointestinal cystic tumors were induced by monoallelic, but not biallelic Ptch mutations, independently of the time-point of mutation induction. These data suggest that the expressivity of Ptch deficiency is largely determined by the time-point, the gene dose and mode of Ptch inactivation. Furthermore, they point to key differences in the tumorigenic mechanisms underlying adult and childhood tumors. The latter ones are unique among all tumors since their occurrence decreases rather than increases with age. A better understanding of mechanisms underlying this ontological restriction is of potential therapeutic value.

  1. Minimum time solar sailing from geosynchronous orbit to the sun-earth L2 point

    NASA Astrophysics Data System (ADS)

    Hur, Sun H.; Bryson, Arthur E., Jr.

    1992-08-01

    An approximate time-optimal of a solar sail from a geosynchronous orbit to the sun-earth L2 libration point is found using a combined method of local optimization and single shooting. The local optimization strategy is based on maximizing the time rate of change of an energy variable at each time. This strategy overcomes the numerical difficulties associated with solving optimal control problems of long duration like the solar sail transfer problem. The single shooting portion of the method is employed to meet the terminal constraints. The combined method can be applied to other optimal low thrust transfer problems of long duration.

  2. A point implicit time integration technique for slow transient flow problems

    SciTech Connect

    Kadioglu, Samet Y.; Berry, Ray A.; Martineau, Richard C.

    2015-05-01

    We introduce a point implicit time integration technique for slow transient flow problems. The method treats the solution variables of interest (that can be located at cell centers, cell edges, or cell nodes) implicitly and the rest of the information related to same or other variables are handled explicitly. The method does not require implicit iteration; instead it time advances the solutions in a similar spirit to explicit methods, except it involves a few additional function(s) evaluation steps. Moreover, the method is unconditionally stable, as a fully implicit method would be. This new approach exhibits the simplicity of implementation of explicit methods and the stability of implicit methods. It is specifically designed for slow transient flow problems of long duration wherein one would like to perform time integrations with very large time steps. Because the method can be time inaccurate for fast transient problems, particularly with larger time steps, an appropriate solution strategy for a problem that evolves from a fast to a slow transient would be to integrate the fast transient with an explicit or semi-implicit technique and then switch to this point implicit method as soon as the time variation slows sufficiently. We have solved several test problems that result from scalar or systems of flow equations. Our findings indicate the new method can integrate slow transient problems very efficiently; and its implementation is very robust.

  3. Incremental Real-Time Bundle Adjustment for Multi-Camera Systems with Points at Infinity

    NASA Astrophysics Data System (ADS)

    Schneider, J.; Läbe, T.; Förstner, W.

    2013-08-01

    This paper presents a concept and first experiments on a keyframe-based incremental bundle adjustment for real-time structure and motion estimation in an unknown scene. In order to avoid periodic batch steps, we use the software iSAM2 for sparse nonlinear incremental optimization, which is highly efficient through incremental variable reordering and fluid relinearization. We adapted the software to allow for (1) multi-view cameras by taking the rigid transformation between the cameras into account, (2) omnidirectional cameras as it can handle arbitrary bundles of rays and (3) scene points at infinity, which improve the estimation of the camera orientation as points at the horizon can be observed over long periods of time. The real-time bundle adjustment refers to sets of keyframes, consisting of frames, one per camera, taken in a synchronized way, that are initiated if a minimal geometric distance to the last keyframe set is exceeded. It uses interest points in the keyframes as observations, which are tracked in the synchronized video streams of the individual cameras and matched across the cameras, if possible. First experiments show the potential of the incremental bundle adjustment w.r.t. time requirements. Our experiments are based on a multi-camera system with four fisheye cameras, which are mounted on a UAV as two stereo pairs, one looking ahead and one looking backwards, providing a large field of view.

  4. A real-time recursive filter for the attitude determination of the Spacelab instrument pointing subsystem

    NASA Technical Reports Server (NTRS)

    West, M. E.

    1992-01-01

    A real-time estimation filter which reduces sensitivity to system variations and reduces the amount of preflight computation is developed for the instrument pointing subsystem (IPS). The IPS is a three-axis stabilized platform developed to point various astronomical observation instruments aboard the shuttle. Currently, the IPS utilizes a linearized Kalman filter (LKF), with premission defined gains, to compensate for system drifts and accumulated attitude errors. Since the a priori gains are generated for an expected system, variations result in a suboptimal estimation process. This report compares the performance of three real-time estimation filters with the current LKF implementation. An extended Kalman filter and a second-order Kalman filter are developed to account for the system nonlinearities, while a linear Kalman filter implementation assumes that the nonlinearities are negligible. The performance of each of the four estimation filters are compared with respect to accuracy, stability, settling time, robustness, and computational requirements. It is shown, that for the current IPS pointing requirements, the linear Kalman filter provides improved robustness over the LKF with less computational requirements than the two real-time nonlinear estimation filters.

  5. Two Time Point MS Lesion Segmentation in Brain MRI: An Expectation-Maximization Framework

    PubMed Central

    Jain, Saurabh; Ribbens, Annemie; Sima, Diana M.; Cambron, Melissa; De Keyser, Jacques; Wang, Chenyu; Barnett, Michael H.; Van Huffel, Sabine; Maes, Frederik; Smeets, Dirk

    2016-01-01

    Purpose: Lesion volume is a meaningful measure in multiple sclerosis (MS) prognosis. Manual lesion segmentation for computing volume in a single or multiple time points is time consuming and suffers from intra and inter-observer variability. Methods: In this paper, we present MSmetrix-long: a joint expectation-maximization (EM) framework for two time point white matter (WM) lesion segmentation. MSmetrix-long takes as input a 3D T1-weighted and a 3D FLAIR MR image and segments lesions in three steps: (1) cross-sectional lesion segmentation of the two time points; (2) creation of difference image, which is used to model the lesion evolution; (3) a joint EM lesion segmentation framework that uses output of step (1) and step (2) to provide the final lesion segmentation. The accuracy (Dice score) and reproducibility (absolute lesion volume difference) of MSmetrix-long is evaluated using two datasets. Results: On the first dataset, the median Dice score between MSmetrix-long and expert lesion segmentation was 0.63 and the Pearson correlation coefficient (PCC) was equal to 0.96. On the second dataset, the median absolute volume difference was 0.11 ml. Conclusions: MSmetrix-long is accurate and consistent in segmenting MS lesions. Also, MSmetrix-long compares favorably with the publicly available longitudinal MS lesion segmentation algorithm of Lesion Segmentation Toolbox. PMID:28066162

  6. Two Time Point MS Lesion Segmentation in Brain MRI: An Expectation-Maximization Framework.

    PubMed

    Jain, Saurabh; Ribbens, Annemie; Sima, Diana M; Cambron, Melissa; De Keyser, Jacques; Wang, Chenyu; Barnett, Michael H; Van Huffel, Sabine; Maes, Frederik; Smeets, Dirk

    2016-01-01

    Purpose: Lesion volume is a meaningful measure in multiple sclerosis (MS) prognosis. Manual lesion segmentation for computing volume in a single or multiple time points is time consuming and suffers from intra and inter-observer variability. Methods: In this paper, we present MSmetrix-long: a joint expectation-maximization (EM) framework for two time point white matter (WM) lesion segmentation. MSmetrix-long takes as input a 3D T1-weighted and a 3D FLAIR MR image and segments lesions in three steps: (1) cross-sectional lesion segmentation of the two time points; (2) creation of difference image, which is used to model the lesion evolution; (3) a joint EM lesion segmentation framework that uses output of step (1) and step (2) to provide the final lesion segmentation. The accuracy (Dice score) and reproducibility (absolute lesion volume difference) of MSmetrix-long is evaluated using two datasets. Results: On the first dataset, the median Dice score between MSmetrix-long and expert lesion segmentation was 0.63 and the Pearson correlation coefficient (PCC) was equal to 0.96. On the second dataset, the median absolute volume difference was 0.11 ml. Conclusions: MSmetrix-long is accurate and consistent in segmenting MS lesions. Also, MSmetrix-long compares favorably with the publicly available longitudinal MS lesion segmentation algorithm of Lesion Segmentation Toolbox.

  7. Point-of-care diagnostics: will the hurdles be overcome this time?

    PubMed

    Huckle, David

    2006-07-01

    Point-of-care diagnostics have been proposed as the latest development in clinical diagnostics several times in the last 30 years; however, they have not yet fully developed into a business sector to match the projections. This perspective examines the reasons for past failures and the failure of technology to meet user needs. Advances have taken place in the last few years that effectively remove technology as a barrier to the development of point-of-care testing. Even regulatory issues regarding how products are developed and claims supported have been absorbed, understood and now accepted. The emphasis here is on the possible favorable aspects that are novel this time around. These changes have arisen as a result of the situation with global healthcare economics and the pressure from patients to be treated more like customers. The final hurdles relate to the conflict between diagnosis with the patient present and treated as soon as the point-of-care result is available and the entrenched positions of the central laboratory, the suppliers and their established distribution chains, and the way in which healthcare budgets are allocated. The ultimate hurdle that encapsulates all of these issues is reimbursement, which is the final barrier to a significant point-of-care diagnostics market--without reimbursement there will be no market.

  8. Meta-Analysis of Effect Sizes Reported at Multiple Time Points Using General Linear Mixed Model

    PubMed Central

    Musekiwa, Alfred; Manda, Samuel O. M.; Mwambi, Henry G.; Chen, Ding-Geng

    2016-01-01

    Meta-analysis of longitudinal studies combines effect sizes measured at pre-determined time points. The most common approach involves performing separate univariate meta-analyses at individual time points. This simplistic approach ignores dependence between longitudinal effect sizes, which might result in less precise parameter estimates. In this paper, we show how to conduct a meta-analysis of longitudinal effect sizes where we contrast different covariance structures for dependence between effect sizes, both within and between studies. We propose new combinations of covariance structures for the dependence between effect size and utilize a practical example involving meta-analysis of 17 trials comparing postoperative treatments for a type of cancer, where survival is measured at 6, 12, 18 and 24 months post randomization. Although the results from this particular data set show the benefit of accounting for within-study serial correlation between effect sizes, simulations are required to confirm these results. PMID:27798661

  9. A Time-Domain CMOS Oscillator-Based Thermostat with Digital Set-Point Programming

    PubMed Central

    Chen, Chun-Chi; Lin, Shih-Hao

    2013-01-01

    This paper presents a time-domain CMOS oscillator-based thermostat with digital set-point programming [without a digital-to-analog converter (DAC) or external resistor] to achieve on-chip thermal management of modern VLSI systems. A time-domain delay-line-based thermostat with multiplexers (MUXs) was used to substantially reduce the power consumption and chip size, and can benefit from the performance enhancement due to the scaling down of fabrication processes. For further cost reduction and accuracy enhancement, this paper proposes a thermostat using two oscillators that are suitable for time-domain curvature compensation instead of longer linear delay lines. The final time comparison was achieved using a time comparator with a built-in custom hysteresis to generate the corresponding temperature alarm and control. The chip size of the circuit was reduced to 0.12 mm2 in a 0.35-μm TSMC CMOS process. The thermostat operates from 0 to 90 °C, and achieved a fine resolution better than 0.05 °C and an improved inaccuracy of ± 0.6 °C after two-point calibration for eight packaged chips. The power consumption was 30 μW at a sample rate of 10 samples/s. PMID:23385403

  10. A time-domain CMOS oscillator-based thermostat with digital set-point programming.

    PubMed

    Chen, Chun-Chi; Lin, Shih-Hao

    2013-01-29

    This paper presents a time-domain CMOS oscillator-based thermostat with digital set-point programming [without a digital-to-analog converter (DAC) or external resistor] to achieve on-chip thermal management of modern VLSI systems. A time-domain delay-line-based thermostat with multiplexers (MUXs) was used to substantially reduce the power consumption and chip size, and can benefit from the performance enhancement due to the scaling down of fabrication processes. For further cost reduction and accuracy enhancement, this paper proposes a thermostat using two oscillators that are suitable for time-domain curvature compensation instead of longer linear delay lines. The final time comparison was achieved using a time comparator with a built-in custom hysteresis to generate the corresponding temperature alarm and control. The chip size of the circuit was reduced to 0.12 mm2 in a 0.35-mm TSMC CMOS process. The thermostat operates from 0 to 90 °C, and achieved a fine resolution better than 0.05 °C and an improved inaccuracy of ± 0.6 °C after two-point calibration for eight packaged chips. The power consumption was 30 µW at a sample rate of 10 samples/s.

  11. Detecting space-time alternating biological signals close to the bifurcation point.

    PubMed

    Jia, Zhiheng; Bien, Harold; Entcheva, Emilia

    2010-02-01

    Time-alternating biological signals, i.e., alternans, arise in variety of physiological states marked by dynamic instabilities, e.g., period doubling. Normally, a sequence of large-small-large transients, they can exhibit variable patterns over time and space, including spatial discordance. Capture of the early formation of such alternating regions is challenging because of the spatiotemporal similarities between noise and the small-amplitude alternating signals close to the bifurcation point. We present a new approach for automatic detection of alternating signals in large noisy spatiotemporal datasets by exploiting quantitative measures of alternans evolution, e.g., temporal persistence, and by preserving phase information. The technique specifically targets low amplitude, relatively short alternating sequences and is validated by combinatorics-derived probabilities and empirical datasets with white noise. Using high-resolution optical mapping in live cardiomyocyte networks, exhibiting calcium alternans, we reveal for the first time early fine-scale alternans, close to the noise level, which are linked to the later formation of larger regions and evolution of spatially discordant alternans. This robust method aims at quantification and better understanding of the onset of cardiac arrhythmias and can be applied to general analysis of space-time alternating signals, including the vicinity of the bifurcation point.

  12. Analysis of the kinetics of lipid peroxidation in terms of characteristic time-points.

    PubMed

    Pinchuk, Ilya; Lichtenberg, Dov

    2014-02-01

    Measuring peroxidation of aggregated lipids in model systems (liposomes, micelles, emulsions or microemulsions) as well as in samples of biological origin ex vivo (isolated lipoproteins, blood sera or plasma) is widely used in medical and biological investigations, to evaluate the oxidative stress, antioxidants' efficiency and lipid oxidizability in different pathophysiological states. To avoid possible artifacts, such investigations must be based on the time course of peroxidation (i.e. on kinetic studies). To be able to compare complex kinetic profiles, it is important to characterize them in terms of mechanistically meaningful and experimentally unequivocal parameters. In this review, we characterize the typically observed continuous kinetic profiles in terms of a limited number of characteristic time-points (both commonly used and additional time-points and their combinations) that can be derived from experimental time-dependencies. The meaning of each of the experimentally observed characteristic parameters is presented in terms of rate constants and concentrations, derived on the basis of mechanistic considerations. Theoretical expressions for these characteristic parameters are based on a model that includes both the inhibited peroxidation and the uninhibited peroxidation occurring after consumption of the antioxidant(s). Comparison between theoretically predicted dependencies and experimental data support our treatment considered with special emphasis on transition metals-induced peroxidation of lipoproteins.

  13. Motion data classification on the basis of dynamic time warping with a cloud point distance measure

    NASA Astrophysics Data System (ADS)

    Switonski, Adam; Josinski, Henryk; Zghidi, Hafedh; Wojciechowski, Konrad

    2016-06-01

    The paper deals with the problem of classification of model free motion data. The nearest neighbors classifier which is based on comparison performed by Dynamic Time Warping transform with cloud point distance measure is proposed. The classification utilizes both specific gait features reflected by a movements of subsequent skeleton joints and anthropometric data. To validate proposed approach human gait identification challenge problem is taken into consideration. The motion capture database containing data of 30 different humans collected in Human Motion Laboratory of Polish-Japanese Academy of Information Technology is used. The achieved results are satisfactory, the obtained accuracy of human recognition exceeds 90%. What is more, the applied cloud point distance measure does not depend on calibration process of motion capture system which results in reliable validation.

  14. New real-time-PCR method to identify single point mutations in hepatitis C virus

    PubMed Central

    Chen, Qian; Belmonte, Irene; Buti, Maria; Nieto, Leonardo; Garcia-Cehic, Damir; Gregori, Josep; Perales, Celia; Ordeig, Laura; Llorens, Meritxell; Soria, Maria Eugenia; Esteban, Rafael; Esteban, Juan Ignacio; Rodriguez-Frias, Francisco; Quer, Josep

    2016-01-01

    AIM To develop a fast, low-cost diagnostic strategy to identify single point mutations in highly variable genomes such as hepatitis C virus (HCV). METHODS In patients with HCV infection, resistance-associated amino acid substitutions within the viral quasispecies prior to therapy can confer decreased susceptibility to direct-acting antiviral agents and lead to treatment failure and virological relapse. One such naturally occurring mutation is the Q80K substitution in the HCV-NS3 protease gene, which confers resistance to PI inhibitors, particularly simeprevir. Low-cost, highly sensitive techniques enabling routine detection of these single point mutations would be useful to identify patients at a risk of treatment failure. LightCycler methods, based on real-time PCR with sequence-specific probe hybridization, have been implemented in most diagnostic laboratories. However, this technique cannot identify single point mutations in highly variable genetic environments, such as the HCV genome. To circumvent this problem, we developed a new method to homogenize all nucleotides present in a region except the point mutation of interest. RESULTS Using nucleotide-specific probes Q, K, and R substitutions at position 80 were clearly identified at a sensitivity of 10% (mutations present at a frequency of at least 10% were detected). The technique was successfully applied to identify the Q80K substitution in 240 HCV G1 serum samples, with performance comparable to that of direct Sanger sequencing, the current standard procedure for this purpose. The new method was then validated in a Catalonian population of 202 HCV G1-infected individuals. Q80K was detected in 14.6% of G1a patients and 0% of G1b in our setting. CONCLUSION A fast, low-cost diagnostic strategy based on real-time PCR and fluorescence resonance energy transfer probe melting curve analysis has been successfully developed to identify single point mutations in highly variable genomes such as hepatitis C virus. This

  15. Calculation of power spectrums from digital time series with missing data points

    NASA Technical Reports Server (NTRS)

    Murray, C. W., Jr.

    1980-01-01

    Two algorithms are developed for calculating power spectrums from the autocorrelation function when there are missing data points in the time series. Both methods use an average sampling interval to compute lagged products. One method, the correlation function power spectrum, takes the discrete Fourier transform of the lagged products directly to obtain the spectrum, while the other, the modified Blackman-Tukey power spectrum, takes the Fourier transform of the mean lagged products. Both techniques require fewer calculations than other procedures since only 50% to 80% of the maximum lags need be calculated. The algorithms are compared with the Fourier transform power spectrum and two least squares procedures (all for an arbitrary data spacing). Examples are given showing recovery of frequency components from simulated periodic data where portions of the time series are missing and random noise has been added to both the time points and to values of the function. In addition the methods are compared using real data. All procedures performed equally well in detecting periodicities in the data.

  16. Time reversal ultrasound focusing to a point away from the beacon location

    NASA Astrophysics Data System (ADS)

    Sinelnikov, Yegor; Sutin, Alexander; Gandhi, Gaurav; Sarvazyan, Armen

    2012-10-01

    In percutaneous procedures there is often a need to focus therapeutic ultrasound to a predefined area without affecting surrounding tissues. Focusing based on Time Reversal Acoustics (TRA) principles constitutes a promising approach for generating high intensity ultrasound field tailored to the shape of the predefined area. Conventional TRA technique enables ultrasound focusing only at a site, where there is an ultrasound beacon, e.g. piezo-transducer mounted at the tip of a catheter. We developed a method of steering the focus away from the beacon location. The method is based on the measurements of impulse response (IR) in several reference points and calculating virtual IRs for the points outside the reference beacon location. The IR for the point away from the beacon is constructed based on mathematical extrapolation of the measured reference IRs frequency spectra, particularly phases. The effectiveness of extrapolated TRA focusing is explored experimentally and by computer simulation. Potential applications include ultrasounda-ssisted drug delivery, artery recanalization and tumor ablation.

  17. Real-time IP-hologram conversion hardware based on floating point DSPs

    NASA Astrophysics Data System (ADS)

    Oi, Ryutaro; Mishina, Tomoyuki; Yamamoto, Kenji; Okui, Makoto

    2009-02-01

    Holography is a 3-D display method that fully satisfies the visual characteristics of the human eye. However, the hologram must be developed in a darkroom under laser illumination. We attempted hologram generation under white light by adopting an integral photography (IP) technique as the input. In this research, we developed a hardware converter to convert IP input (with 120×66 elemental images) to a hologram with high definition television (HDTV) resolution (approximately 2 million pixels). This conversion could be carried out in real time. In this conversion method, each elemental image can be independently extracted and processed. Our hardware contains twenty 300-MHz floating-point digital signal processors (DSPs) operating in parallel. We verified real-time conversion operations by the implemented hardware.

  18. Time delay of critical images in the vicinity of cusp point of gravitational-lens systems

    NASA Astrophysics Data System (ADS)

    Alexandrov, A.; Zhdanov, V.

    2016-12-01

    We consider approximate analytical formulas for time-delays of critical images of a point source in the neighborhood of a cusp-caustic. We discuss zero, first and second approximations in powers of a parameter that defines the proximity of the source to the cusp. These formulas link the time delay with characteristics of the lens potential. The formula of zero approximation was obtained by Congdon, Keeton & Nordgren (MNRAS, 2008). In case of a general lens potential we derived first order correction thereto. If the potential is symmetric with respect to the cusp axis, then this correction is identically equal to zero. For this case, we obtained second order correction. The relations found are illustrated by a simple model example.

  19. Repair of Physiologic Time Series: Replacement of Anomalous Data Points to Preserve Fractal Exponents

    PubMed Central

    Shelhamer, Mark; Lowen, Steven B.

    2017-01-01

    Extraction of fractal exponents via the slope of the power spectrum is common in the analysis of many physiological time series. The fractal structure thus characterized is a manifestation of long-term correlations, for which the temporal order of the sample values is crucial. However, missing data points due to artifacts and dropouts are common in such data sets, which can seriously disrupt the computation of fractal parameters. We evaluated a number of methods for replacing missing data in time series to enable reliable extraction of the fractal exponent and make recommendations as to the preferred replacement method depending on the proportion of missing values and any a priori estimate of the fractal exponent. PMID:28271060

  20. A Novel Method for Fast Change-Point Detection on Simulated Time Series and Electrocardiogram Data

    PubMed Central

    Qi, Jin-Peng; Zhang, Qing; Zhu, Ying; Qi, Jie

    2014-01-01

    Although Kolmogorov-Smirnov (KS) statistic is a widely used method, some weaknesses exist in investigating abrupt Change Point (CP) problems, e.g. it is time-consuming and invalid sometimes. To detect abrupt change from time series fast, a novel method is proposed based on Haar Wavelet (HW) and KS statistic (HWKS). First, the two Binary Search Trees (BSTs), termed TcA and TcD, are constructed by multi-level HW from a diagnosed time series; the framework of HWKS method is implemented by introducing a modified KS statistic and two search rules based on the two BSTs; and then fast CP detection is implemented by two HWKS-based algorithms. Second, the performance of HWKS is evaluated by simulated time series dataset. The simulations show that HWKS is faster, more sensitive and efficient than KS, HW, and T methods. Last, HWKS is applied to analyze the electrocardiogram (ECG) time series, the experiment results show that the proposed method can find abrupt change from ECG segment with maximal data fluctuation more quickly and efficiently, and it is very helpful to inspect and diagnose the different state of health from a patient's ECG signal. PMID:24690633

  1. Scattering experiments with microwave billiards at an exceptional point under broken time-reversal invariance.

    PubMed

    Bittner, S; Dietz, B; Harney, H L; Miski-Oglu, M; Richter, A; Schäfer, F

    2014-03-01

    Scattering experiments with microwave cavities were performed and the effects of broken time-reversal invariance (TRI), induced by means of a magnetized ferrite placed inside the cavity, on an isolated doublet of nearly degenerate resonances were investigated. All elements of the effective Hamiltonian of this two-level system were extracted. As a function of two experimental parameters, the doublet and the associated eigenvectors could be tuned to coalesce at a so-called exceptional point (EP). The behavior of the eigenvalues and eigenvectors when encircling the EP in parameter space was studied, including the geometric amplitude that builds up in the case of broken TRI. A one-dimensional subspace of parameters was found where the differences of the eigenvalues are either real or purely imaginary. There, the Hamiltonians were found to be PT invariant under the combined operation of parity (P) and time reversal (T) in a generalized sense. The EP is the point of transition between both regions. There a spontaneous breaking of PT occurs.

  2. ICESAT Laser Altimeter Pointing, Ranging and Timing Calibration from Integrated Residual Analysis

    NASA Technical Reports Server (NTRS)

    Luthcke, Scott B.; Rowlands, D. D.; Carabajal, C. C.; Harding, D. H.; Bufton, J. L.; Williams, T. A.

    2003-01-01

    On January 12, 2003 the Ice, Cloud and land Elevation Satellite (ICESat) was successfully placed into orbit. The ICESat mission carries the Geoscience Laser Altimeter System (GLAS), which has a primary measurement of short-pulse laser- ranging to the Earth s surface at 1064nm wavelength at a rate of 40 pulses per second. The instrument has collected precise elevation measurements of the ice sheets, sea ice roughness and thickness, ocean and land surface elevations and surface reflectivity. The accurate geolocation of GLAS s surface returns, the spots from which the laser energy reflects on the Earth s surface, is a critical issue in the scientific application of these data. Pointing, ranging, timing and orbit errors must be compensated to accurately geolocate the laser altimeter surface returns. Towards this end, the laser range observations can be fully exploited in an integrated residual analysis to accurately calibrate these geolocation/instrument parameters. ICESat laser altimeter data have been simultaneously processed as direct altimetry from ocean sweeps along with dynamic crossovers in order to calibrate pointing, ranging and timing. The calibration methodology and current calibration results are discussed along with future efforts.

  3. Social behavior in a genetic model of dopamine dysfunction at different neurodevelopmental time points.

    PubMed

    Kabitzke, P A; Simpson, E H; Kandel, E R; Balsam, P D

    2015-09-01

    Impairments in social behavior characterize many neurodevelopmental psychiatric disorders. In fact, the temporal emergence and trajectory of these deficits can define the disorder, specify their treatment and signal their prognosis. The sophistication of mouse models with neurobiological endophenotypes of many aspects of psychiatric diseases has increased in recent years, with the necessity to evaluate social behavior in these models. We adapted an assay for the multimodal characterization of social behavior at different development time points (juvenile, adolescent and adult) in control mice in different social contexts (specifically, different sex pairings). Although social context did not affect social behavior in juvenile mice, it did have an effect on the quantity and type of social interaction as well as ultrasonic vocalizations in both adolescence and adulthood. We compared social development in control mice to a transgenic mouse model of the increase in postsynaptic striatal D2R activity observed in patients with schizophrenia (D2R-OE mice). Genotypic differences in social interactions emerged in adolescence and appeared to become more pronounced in adulthood. That vocalizations emitted from dyads with a D2R-OE subject were negatively correlated with active social behavior while vocalizations from control dyads were positively correlated with both active and passive social behavior also suggest social deficits. These data show that striatal dopamine dysfunction plays an important role in the development of social behavior and mouse models such as the one studied here provide an opportunity for screening potential therapeutics at different developmental time points.

  4. Real-time gesture recognition by learning and selective control of visual interest points.

    PubMed

    Kirishima, Toshiyuki; Sato, Kosuke; Chihara, Kunihiro

    2005-03-01

    For the real-time recognition of unspecified gestures by an arbitrary person, a comprehensive framework is presented that addresses two important problems in gesture recognition systems: selective attention and processing frame rate. To address the first problem, we propose the Quadruple Visual Interest Point Strategy. No assumptions are made with regard to scale or rotation of visual features, which are computed from dynamically changing regions of interest in a given image sequence. In this paper, each of the visual features is referred to as a visual interest point, to which a probability density function is assigned, and the selection is carried out. To address the second problem, we developed a selective control method to equip the recognition system with self-load monitoring and controlling functionality. Through evaluation experiments, we show that our approach provides robust recognition with respect to such factors as type of clothing, type of gesture, extent of motion trajectories, and individual differences in motion characteristics. In order to indicate the real-time performance and utility aspects of our approach, a gesture video system is developed that demonstrates full video-rate interaction with displayed image objects.

  5. Social behavior in a genetic model of dopamine dysfunction at different neurodevelopmental time points

    PubMed Central

    Kabitzke, P. A.; Simpson, E. H.; Kandel, E. R.; Balsam, P. D.

    2016-01-01

    Impairments in social behavior characterize many neurodevelopmental psychiatric disorders. In fact, the temporal emergence and trajectory of these deficits can define the disorder, specify their treatment and signal their prognosis. The sophistication of mouse models with neurobiological endophenotypes of many aspects of psychiatric diseases has increased in recent years, with the necessity to evaluate social behavior in these models. We adapted an assay for the multimodal characterization of social behavior at different development time points (juvenile, adolescent and adult) in control mice in different social contexts (specifically, different sex pairings). Although social context did not affect social behavior in juvenile mice, it did have an effect on the quantity and type of social interaction as well as ultrasonic vocalizations in both adolescence and adulthood. We compared social development in control mice to a transgenic mouse model of the increase in postsynaptic striatal D2R activity observed in patients with schizophrenia (D2R-OE mice). Genotypic differences in social interactions emerged in adolescence and appeared to become more pronounced in adulthood. That vocalizations emitted from dyads with a D2R-OE subject were negatively correlated with active social behavior while vocalizations from control dyads were positively correlated with both active and passive social behavior also suggest social deficits. These data show that striatal dopamine dysfunction plays an important role in the development of social behavior and mouse models such as the one studied here provide an opportunity for screening potential therapeutics at different developmental time points. PMID:26176662

  6. Real-Time Single Frequency Precise Point Positioning Using SBAS Corrections

    PubMed Central

    Li, Liang; Jia, Chun; Zhao, Lin; Cheng, Jianhua; Liu, Jianxu; Ding, Jicheng

    2016-01-01

    Real-time single frequency precise point positioning (PPP) is a promising technique for high-precision navigation with sub-meter or even centimeter-level accuracy because of its convenience and low cost. The navigation performance of single frequency PPP heavily depends on the real-time availability and quality of correction products for satellite orbits and satellite clocks. Satellite-based augmentation system (SBAS) provides the correction products in real-time, but they are intended to be used for wide area differential positioning at 1 meter level precision. By imposing the constraints for ionosphere error, we have developed a real-time single frequency PPP method by sufficiently utilizing SBAS correction products. The proposed PPP method are tested with static and kinematic data, respectively. The static experimental results show that the position accuracy of the proposed PPP method can reach decimeter level, and achieve an improvement of at least 30% when compared with the traditional SBAS method. The positioning convergence of the proposed PPP method can be achieved in 636 epochs at most in static mode. In the kinematic experiment, the position accuracy of the proposed PPP method can be improved by at least 20 cm relative to the SBAS method. Furthermore, it has revealed that the proposed PPP method can achieve decimeter level convergence within 500 s in the kinematic mode. PMID:27517930

  7. Six-month functional recovery of stroke patients: a multi-time-point study

    PubMed Central

    Lee, Kyoung Bo; Lim, Seong Hoon; Kim, Kyung Hoon; Kim, Ki Jeon; Kim, Yang Rae; Chang, Woo Nam; Yeom, Jun Woo; Kim, Young Dong

    2015-01-01

    The aim of this study is to compare the time-course changes in neurologic impairments (trunk control, motor function, sensory, and cognition) and recovery in functional impairments (activity of daily livings and gait) simultaneously from initiating rehabilitation to 6 months after stroke. Consecutive stroke patients were recruited from the department of nervous surgery, and transferred into the department of rehabilitation medicine and continued on treatment during the acute stage. Outcome measures were examined at the initial rehabilitation baseline, 1, 2, and 4 weeks after rehabilitation treatment, and 3, 4, 5, and 6 months after stroke. Patients were assessed using the Trunk Impairment Scale, the Fugl-Meyer Motor and Sensory Assessments for the upper and lower limbs, Mini-Mental State Examination, Functional Ambulation Category, and Modified Barthel Index. Twenty consecutive patients were analyzed in the study with complete assessments. The recovery was relatively rapid during the 4 weeks after treatment (P value ranges from <0.001 to <0.007) and then to a lesser extent decelerated between 3 and 6 months after stroke (P value between <0.001 and 0.080). Statistical comparison by repeated measures analysis showed a significant interaction between time points and measures of all recovery variables (P<0.001). Significant differences in level of impairments and functional recovery were found at the different time points. In comparison with the lower leg and trunk control, the upper arm showed less recovery, with a significant difference. All variables except for leg motor function improved continuously over 6 months after stroke. Nevertheless, this study confirms the importance of the period within 3 months for recovery after stroke, during which most of the recovery occurred, ranging from 48 to 91%. Therefore, intensive treatment targeting motor and sensory functions early after stroke may be beneficial for recovery of impairments and functional performance. PMID

  8. Double point source W-phase inversion: Real-time implementation and automated model selection

    USGS Publications Warehouse

    Nealy, Jennifer; Hayes, Gavin

    2015-01-01

    Rapid and accurate characterization of an earthquake source is an extremely important and ever evolving field of research. Within this field, source inversion of the W-phase has recently been shown to be an effective technique, which can be efficiently implemented in real-time. An extension to the W-phase source inversion is presented in which two point sources are derived to better characterize complex earthquakes. A single source inversion followed by a double point source inversion with centroid locations fixed at the single source solution location can be efficiently run as part of earthquake monitoring network operational procedures. In order to determine the most appropriate solution, i.e., whether an earthquake is most appropriately described by a single source or a double source, an Akaike information criterion (AIC) test is performed. Analyses of all earthquakes of magnitude 7.5 and greater occurring since January 2000 were performed with extended analyses of the September 29, 2009 magnitude 8.1 Samoa earthquake and the April 19, 2014 magnitude 7.5 Papua New Guinea earthquake. The AIC test is shown to be able to accurately select the most appropriate model and the selected W-phase inversion is shown to yield reliable solutions that match published analyses of the same events.

  9. Double Point Source W-phase Inversion: Real-time Implementation and Automated Model Selection

    NASA Astrophysics Data System (ADS)

    Nealy, J. L.; Hayes, G. P.

    2015-12-01

    Rapid and accurate characterization of an earthquake source is an extremely important and ever-evolving field of research. Within this field, source inversion of the W-phase has recently been shown to be an effective technique, which can be efficiently implemented in real-time. An extension to the W-phase source inversion is presented in which two point sources are derived to better characterize complex earthquakes. A single source inversion followed by a double point source inversion with centroid locations fixed at the single source solution location can be efficiently run as part of earthquake monitoring network operational procedures. In order to determine the most appropriate solution, i.e., whether an earthquake is most appropriately described by a single source or a double source, an Akaike information criterion (AIC) test is performed. Analyses of all earthquakes of magnitude 7.5 and greater occurring since January 2000 were performed with extended analyses of the September 29, 2009 magnitude 8.1 Samoa and the April 19, 2014 magnitude 7.5 Papua New Guinea earthquakes. The AIC test is shown to be able to accurately select the most appropriate model and the selected W-phase inversion is shown to yield reliable solutions that match previously published analyses of the same events.

  10. Double point source W-phase inversion: Real-time implementation and automated model selection

    NASA Astrophysics Data System (ADS)

    Nealy, Jennifer L.; Hayes, Gavin P.

    2015-12-01

    Rapid and accurate characterization of an earthquake source is an extremely important and ever evolving field of research. Within this field, source inversion of the W-phase has recently been shown to be an effective technique, which can be efficiently implemented in real-time. An extension to the W-phase source inversion is presented in which two point sources are derived to better characterize complex earthquakes. A single source inversion followed by a double point source inversion with centroid locations fixed at the single source solution location can be efficiently run as part of earthquake monitoring network operational procedures. In order to determine the most appropriate solution, i.e., whether an earthquake is most appropriately described by a single source or a double source, an Akaike information criterion (AIC) test is performed. Analyses of all earthquakes of magnitude 7.5 and greater occurring since January 2000 were performed with extended analyses of the September 29, 2009 magnitude 8.1 Samoa earthquake and the April 19, 2014 magnitude 7.5 Papua New Guinea earthquake. The AIC test is shown to be able to accurately select the most appropriate model and the selected W-phase inversion is shown to yield reliable solutions that match published analyses of the same events.

  11. Single-point position and transition defects in continuous time quantum walks

    PubMed Central

    Li, Z. J.; Wang, J. B.

    2015-01-01

    We present a detailed analysis of continuous time quantum walks (CTQW) with both position and transition defects defined at a single point in the line. Analytical solutions of both traveling waves and bound states are obtained, which provide valuable insight into the dynamics of CTQW. The number of bound states is found to be critically dependent on the defect parameters, and the localized probability peaks can be readily obtained by projecting the state vector of CTQW on to these bound states. The interference between two bound states are also observed in the case of a transition defect. The spreading of CTQW probability over the line can be finely tuned by varying the position and transition defect parameters, offering the possibility of precision quantum control of the system. PMID:26323855

  12. Implementation of a Point Algorithm for Real-Time Convex Optimization

    NASA Technical Reports Server (NTRS)

    Acikmese, Behcet; Motaghedi, Shui; Carson, John

    2007-01-01

    The primal-dual interior-point algorithm implemented in G-OPT is a relatively new and efficient way of solving convex optimization problems. Given a prescribed level of accuracy, the convergence to the optimal solution is guaranteed in a predetermined, finite number of iterations. G-OPT Version 1.0 is a flight software implementation written in C. Onboard application of the software enables autonomous, real-time guidance and control that explicitly incorporates mission constraints such as control authority (e.g. maximum thrust limits), hazard avoidance, and fuel limitations. This software can be used in planetary landing missions (Mars pinpoint landing and lunar landing), as well as in proximity operations around small celestial bodies (moons, asteroids, and comets). It also can be used in any spacecraft mission for thrust allocation in six-degrees-of-freedom control.

  13. Undergraduate Consent Form Reading in Relation to Conscientiousness, Procrastination, and the Point-of-Time Effect.

    PubMed

    Theiss, Justin D; Hobbs, William B; Giordano, Peter J; Brunson, Olivia M

    2014-07-01

    Informed consent is central to conducting ethical research with human participants. The present study investigated differences in consent form reading in relation to conscientiousness, procrastination, and the point-of-time (PT) effect among undergraduate participants at a U.S. university. As hypothesized, conscientious participants and those who signed up to participate in a research study more days in advance and for earlier sessions (PT effect) read the consent form more thoroughly. However, procrastination was not related to consent form reading. Most importantly, consent form reading in general was poor, with 80% of participants demonstrating that they had not read the consent form. Conscientious participants were more likely to self-report reading the consent form, irrespective of their measured consent form reading. The article closes with suggestions to improve the process of obtaining informed consent with undergraduate participants.

  14. Travel Time Estimation Using Freeway Point Detector Data Based on Evolving Fuzzy Neural Inference System.

    PubMed

    Tang, Jinjun; Zou, Yajie; Ash, John; Zhang, Shen; Liu, Fang; Wang, Yinhai

    2016-01-01

    Travel time is an important measurement used to evaluate the extent of congestion within road networks. This paper presents a new method to estimate the travel time based on an evolving fuzzy neural inference system. The input variables in the system are traffic flow data (volume, occupancy, and speed) collected from loop detectors located at points both upstream and downstream of a given link, and the output variable is the link travel time. A first order Takagi-Sugeno fuzzy rule set is used to complete the inference. For training the evolving fuzzy neural network (EFNN), two learning processes are proposed: (1) a K-means method is employed to partition input samples into different clusters, and a Gaussian fuzzy membership function is designed for each cluster to measure the membership degree of samples to the cluster centers. As the number of input samples increases, the cluster centers are modified and membership functions are also updated; (2) a weighted recursive least squares estimator is used to optimize the parameters of the linear functions in the Takagi-Sugeno type fuzzy rules. Testing datasets consisting of actual and simulated data are used to test the proposed method. Three common criteria including mean absolute error (MAE), root mean square error (RMSE), and mean absolute relative error (MARE) are utilized to evaluate the estimation performance. Estimation results demonstrate the accuracy and effectiveness of the EFNN method through comparison with existing methods including: multiple linear regression (MLR), instantaneous model (IM), linear model (LM), neural network (NN), and cumulative plots (CP).

  15. An Integrated 0-1 Hour First-Flash Lightning Nowcasting, Lightning Amount and Lightning Jump Warning Capability

    NASA Technical Reports Server (NTRS)

    Mecikalski, John; Jewett, Chris; Carey, Larry; Zavodsky, Brad; Stano, Geoffrey; Chronis, Themis

    2015-01-01

    Using satellite-based methods that provide accurate 0-1 hour convective initiation (CI) nowcasts, and rely on proven success coupling satellite and radar fields in the Corridor Integrated Weather System (CIWS; operated and developed at MIT-Lincoln Laboratory), to subsequently monitor for first-flash lightning initiation (LI) and later period lightning trends as storms evolve. Enhance IR-based methods within the GOES-R CI Algorithm (that must meet specific thresholds for a given cumulus cloud before the cloud is considered to have an increased likelihood of producing lightning next 90 min) that forecast LI. Integrate GOES-R CI and LI fields with radar thresholds (e.g., first greater than or equal to 40 dBZ echo at the -10 C altitude) and NWP model data within the WDSS-II system for LI-events from new convective storms. Track ongoing lightning using Lightning Mapping Array (LMA) and pseudo-Geostationary Lightning Mapper (GLM) data to assess per-storm lightning trends (e.g., as tied to lightning jumps) and outline threat regions. Evaluate the ability to produce LI nowcasts through a "lightning threat" product, and obtain feedback from National Weather Service forecasters on its value as a decision support tool.

  16. A periodicity of approximately 1 hour in X-ray emission from the active galaxy RE J1034+396.

    PubMed

    Gierliński, Marek; Middleton, Matthew; Ward, Martin; Done, Chris

    2008-09-18

    Active galactic nuclei and quasars are thought to be scaled-up versions of Galactic black hole binaries, powered by accretion onto supermassive black holes with masses of 10(6)-10(9) M[symbol: see text], as opposed to the approximately 10 M [symbol: see text] in binaries (here M [symbol: see text] is the solar mass). One example of the similarities between these two types of systems is the characteristic rapid X-ray variability seen from the accretion flow. The power spectrum of this variability in black hole binaries consists of a broad noise with multiple quasi-periodic oscillations superimposed on it. Although the broad noise component has been observed in many active galactic nuclei, there have hitherto been no significant detections of quasi-periodic oscillations. Here we report the discovery of an approximately 1-hour X-ray periodicity in a bright active galaxy, RE J1034+396. The signal is highly statistically significant (at the 5.6 sigma level) and very coherent, with quality factor Q > 16. The X-ray modulation arises from the direct vicinity of the black hole.

  17. Real-time Precise Point Positioning with Ambiguity Resolution for Geosciences

    NASA Astrophysics Data System (ADS)

    Geng, J.; Meng, X.; Teferle, F. N.; Dodson, A. H.; Ge, M.; Shi, C.; Liu, J.

    2009-04-01

    Real-time provision of information on large scale crustal deformation during an earthquake can be crucial in assessing property damage and managing relief operations. Moreover, such a real-time monitoring system may even lead to the accurate prediction of earthquakes in future and help the subsequent studies on the mechanism involved. During the past two decades, Global Positioning System (GPS) measurements have been extensively applied to investigate such processes in the geosciences. Precise point positioning (PPP) using GPS based on single stations can achieve comparable accuracies to conventional relative positioning, when precise satellite orbits and clocks, and Earth rotation products are used. Thus, PPP does not need any reference stations to achieve high positioning accuracy, e.g. at the millimetre level in static and centimetre level in kinematic applications. This has both technical and economic advantages and may be the only feasible option in some specific applications such as Tsunami early warning systems. However, unlike relative positioning, PPP suffers from unresolved integer ambiguities, which prevented further accuracy improvements within short observation periods or in real-time. On account of the great potential of PPP, we developed a prototype real-time PPP system which also employs ambiguity resolution at a single station. This development is based on the PANDA (Positioning And Navigation Data Analyst) software, which was originally developed at Wuhan University in China, and has been significantly refined by the authors. To assess this system, about 30 stations from the EUREF Permanent Network Internet Protocol (EUREF-IP) pilot project are used to produce the real-time satellite clocks, with satellite orbits and Earth rotation parameters (ERP) fixed to the predicted part of the IGS (International GNSS Service) ultra-rapid products. This is followed by the estimation of the uncalibrated hardware delays (UHD), which are crucial in resolving the

  18. Impact of telavancin on prothrombin time and activated partial thromboplastin time as determined using point-of-care coagulometers.

    PubMed

    Ero, Michael P; Harvey, Nathaniel R; Harbert, Jack L; Janc, James W; Chin, Kay H; Barriere, Steven L

    2014-01-01

    Telavancin is approved in the United States, Canada, and Europe (At the time of submission, the telavancin European marketing authorization for nosocomial pneumonia was suspended until Theravance provides evidence of a new European Medicines Agency approved supplier) as an antibiotic to treat certain Gram-positive bacterial skin infections. Telavancin has been shown to prolong plasmatic prothrombin (PT) and activated partial thromboplastin (aPTT) clotting times in clinical diagnostic lab-based assays. In this study, we evaluated the potential for telavancin to prolong whole blood PT/International Normalized Ratio (INR) and aPTT tests on point-of-care (POC) instruments. Whole blood collected from 8 healthy subjects was supplemented with telavancin to final concentrations of 0, 10, 20, and 100 μg/ml. Final concentrations were selected to match trough, twice trough, and peak plasma levels following the approved 10 mg/kg dose. Four widely employed POC coagulation instruments were chosen to be representative of the POC platforms currently in use.. These systems were the Roche Coaguchek XS, the Abbott iSTAT, the ITC Hemochron SIG+, and the Alere INRatio2 POC devices. The PT/INR measured by the Coaguchek XS showed the greatest sensitivity to the presence of telavancin. The PT/INR measured by the Hemochron SIG+ and iSTAT were sensitive to telavancin but to a lesser extent. The INRatio2 was the least sensitive to the presence of telavancin when testing the whole blood PT/INR. Only the Hemochron SIG+ device was capable of measuring aPTT and showed a concentration-dependent increase in aPTT. This study supports the current recommendation that PT and aPTT monitoring be conducted immediately to the next dose of telavancin when coagulation parameters are tested using POC instrumentation.

  19. Guidance on Developing Fee Programs Required by Clean Air Act Section 185 for the 1997 1-hour Ozone National Ambient Air Quality Standards (NAAQS)

    EPA Pesticide Factsheets

    This January 2010 memorandum provides additional guidance on fee collection programs for the 1997 1-hour ozone NAAQS, which are required as anti-backsliding measures during transition to the 1997 8-hour ozone standard.

  20. Terahertz time domain interferometry of a SIS tunnel junction and a quantum point contact

    SciTech Connect

    Karadi, Chandu

    1995-09-01

    The author has applied the Terahertz Time Domain Interferometric (THz-TDI) technique to probe the ultrafast dynamic response of a Superconducting-Insulating-Superconducting (SIS) tunnel junction and a Quantum Point Contact (QPC). The THz-TDI technique involves monitoring changes in the dc current induced by interfering two picosecond electrical pulses on the junction as a function of time delay between them. Measurements of the response of the Nb/AlOxNb SIS tunnel junction from 75--200 GHz are in full agreement with the linear theory for photon-assisted tunneling. Likewise, measurements of the induced current in a QPC as a function of source-drain voltage, gate voltage, frequency, and magnetic field also show strong evidence for photon-assisted transport. These experiments together demonstrate the general applicability of the THz-TDI technique to the characterization of the dynamic response of any micron or nanometer scale device that exhibits a non-linear I-V characteristic.

  1. Two Point Space-Time Correlation of Density Fluctuations Measured in High Velocity Free Jets

    NASA Technical Reports Server (NTRS)

    Panda, Jayanta

    2006-01-01

    Two-point space-time correlations of air density fluctuations in unheated, fully-expanded free jets at Mach numbers M(sub j) = 0.95, 1.4, and 1.8 were measured using a Rayleigh scattering based diagnostic technique. The molecular scattered light from two small probe volumes of 1.03 mm length was measured for a completely non-intrusive means of determining the turbulent density fluctuations. The time series of density fluctuations were analyzed to estimate the integral length scale L in a moving frame of reference and the convective Mach number M(sub c) at different narrow Strouhal frequency (St) bands. It was observed that M(sub c) and the normalized moving frame length scale L*St/D, where D is the jet diameter, increased with Strouhal frequency before leveling off at the highest resolved frequency. Significant differences were observed between data obtained from the lip shear layer and the centerline of the jet. The wave number frequency transform of the correlation data demonstrated progressive increase in the radiative part of turbulence fluctuations with increasing jet Mach number.

  2. Travel Time Estimation Using Freeway Point Detector Data Based on Evolving Fuzzy Neural Inference System

    PubMed Central

    Tang, Jinjun; Zou, Yajie; Ash, John; Zhang, Shen; Liu, Fang; Wang, Yinhai

    2016-01-01

    Travel time is an important measurement used to evaluate the extent of congestion within road networks. This paper presents a new method to estimate the travel time based on an evolving fuzzy neural inference system. The input variables in the system are traffic flow data (volume, occupancy, and speed) collected from loop detectors located at points both upstream and downstream of a given link, and the output variable is the link travel time. A first order Takagi-Sugeno fuzzy rule set is used to complete the inference. For training the evolving fuzzy neural network (EFNN), two learning processes are proposed: (1) a K-means method is employed to partition input samples into different clusters, and a Gaussian fuzzy membership function is designed for each cluster to measure the membership degree of samples to the cluster centers. As the number of input samples increases, the cluster centers are modified and membership functions are also updated; (2) a weighted recursive least squares estimator is used to optimize the parameters of the linear functions in the Takagi-Sugeno type fuzzy rules. Testing datasets consisting of actual and simulated data are used to test the proposed method. Three common criteria including mean absolute error (MAE), root mean square error (RMSE), and mean absolute relative error (MARE) are utilized to evaluate the estimation performance. Estimation results demonstrate the accuracy and effectiveness of the EFNN method through comparison with existing methods including: multiple linear regression (MLR), instantaneous model (IM), linear model (LM), neural network (NN), and cumulative plots (CP). PMID:26829639

  3. Integrity monitoring in real-time precise point positioning in the presence of ionospheric disturbances

    NASA Astrophysics Data System (ADS)

    Wezka, K.; Galas, R.

    2013-12-01

    Ionospheric disturbances are characterized as fast and random variability in the ionosphere. Those phenomena are difficult to predict, detect and model. Occurrence of some strong ionospheric disturbances can cause, inter alia degradation and interruption of GNSS signals. Therefore they are especially harmful for real-time applications, as for example Precise Point Positioning (PPP) in real time, where one of the most important requirements is to ensure the high level of reliability. In such applications verification and confirmation of a high trust degree towards the estimated coordinates is a very critical issue. In one of the previous papers (K. Wezka, 2012 -Identification of system performance parameters and their usability) two sets of parameters have been proposed for enhance reliability of the PPP. The first one for data quality control (QC) of the raw GNSS observations and the second one for examination of the quality, robustness and performance of various processing approaches (strategies). To the second group the following parameters has been proposed: accuracy, precision, availability, integrity and convergence time. In consideration of perturbation of GNSS signal resulting from sudden ionospheric disturbances, one of the most important demands is effective autonomous integrity monitoring. The poster presents first preliminary results of the applicability of the proposed parameters in order to ensure the high level of reliability/integrity of GNSS observations and positioning results under the presence of strong ionospheric anomalies. The data-set from continuously operated GNSS station located at high latitude, where ionospheric disturbances occur more frequently, were used for the analysis. Various selected Receiver Autonomous Integrity Monitoring (RAIM) approaches for quality control of the GNSS observables are applied to the data sets recorded under different (low/quite and high) ionospheric activities. Based on those analyses the usability of the

  4. Real Time Precise Point Positioning: Preliminary Results for the Brazilian Region

    NASA Astrophysics Data System (ADS)

    Marques, Haroldo; Monico, João.; Hirokazu Shimabukuro, Milton; Aquino, Marcio

    2010-05-01

    GNSS positioning can be carried out in relative or absolute approach. In the last years, more attention has been driven to the real time precise point positioning (PPP). To achieve centimeter accuracy with this method in real time it is necessary to have available the satellites precise coordinates as well as satellites clocks corrections. The coordinates can be used from the predicted IGU ephemeris, but the satellites clocks must be estimated in a real time. It can be made from a GNSS network as can be seen from EUREF Permanent Network. The infra-structure to realize the PPP in real time is being available in Brazil through the Brazilian Continuous Monitoring Network (RBMC) together with the Sao Paulo State GNSS network which are transmitting GNSS data using NTRIP (Networked Transport of RTCM via Internet Protocol) caster. Based on this information it was proposed a PhD thesis in the Univ. Estadual Paulista (UNESP) aiming to investigate and develop the methodology to estimate the satellites clocks and realize PPP in real time. Then, software is being developed to process GNSS data in the real time PPP mode. A preliminary version of the software was called PPP_RT and is able to process GNSS code and phase data using precise ephemeris and satellites clocks. The PPP processing can be accomplished considering the absolute satellite antenna Phase Center Variation (PCV), Ocean Tide Loading (OTL), Earth Body Tide, among others. The first order ionospheric effects can be eliminated or minimized by ion-free combination or parameterized in the receiver-satellite direction using a stochastic process, e.g. random walk or white noise. In the case of ionosphere estimation, a pseudo-observable is introduced in the mathematical model for each satellite and the initial value can be computed from Klobuchar model or from Global Ionospheric Map (GIM). The adjustment is realized in the recursive mode and the DIA (Detection Identification and Adaptation) is used for quality control. In

  5. The Way Point Planning Tool: Real Time Flight Planning for Airborne Science

    NASA Technical Reports Server (NTRS)

    He, Yubin; Blakeslee, Richard; Goodman, Michael; Hall, John

    2012-01-01

    Airborne real time observation are a major component of NASA's Earth Science research and satellite ground validation studies. For mission scientist, planning a research aircraft mission within the context of meeting the science objective is a complex task because it requires real time situational awareness of the weather conditions that affect the aircraft track. Multiple aircraft are often involved in the NASA field campaigns the coordination of the aircraft with satellite overpasses, other airplanes and the constantly evolving dynamic weather conditions often determine the success of the campaign. A flight planning tool is needed to provide situational awareness information to the mission scientist and help them plan and modify the flight tracks successfully. Scientists at the University of Alabama Huntsville and the NASA Marshal Space Flight Center developed the Waypoint Planning Tool (WPT), an interactive software tool that enables scientist to develop their own flight plans (also known as waypoints), with point and click mouse capabilities on a digital map filled with time raster and vector data. The development of this Waypoint Planning Tool demonstrates the significance of mission support in responding to the challenges presented during NASA field campaigns. Analyses during and after each campaign helped identify both issues and new requirements, initiating the next wave of development. Currently the Waypoint Planning Tool has gone through three rounds of development and analysis processes. The development of this waypoint tool is directly affected by the technology advances on GIS/Mapping technologies. From the standalone Google Earth application and simple KML functionalities to the Google Earth Plugin and Java Web Start/Applet on web platform, as well as to the rising open source GIS tools with new JavaScript frameworks, the Waypoint planning Tool has entered its third phase of technology advancement. The newly innovated, cross-platform, modular designed

  6. Quantum percolation and transition point of a directed discrete-time quantum walk

    PubMed Central

    Chandrashekar, C. M.; Busch, Th.

    2014-01-01

    Quantum percolation describes the problem of a quantum particle moving through a disordered system. While certain similarities to classical percolation exist, the quantum case has additional complexity due to the possibility of Anderson localisation. Here, we consider a directed discrete-time quantum walk as a model to study quantum percolation of a two-state particle on a two-dimensional lattice. Using numerical analysis we determine the fraction of connected edges required (transition point) in the lattice for the two-state particle to percolate with finite (non-zero) probability for three fundamental lattice geometries, finite square lattice, honeycomb lattice, and nanotube structure and show that it tends towards unity for increasing lattice sizes. To support the numerical results we also use a continuum approximation to analytically derive the expression for the percolation probability for the case of the square lattice and show that it agrees with the numerically obtained results for the discrete case. Beyond the fundamental interest to understand the dynamics of a two-state particle on a lattice (network) with disconnected vertices, our study has the potential to shed light on the transport dynamics in various quantum condensed matter systems and the construction of quantum information processing and communication protocols. PMID:25301394

  7. Brachytherapy in cancer cervix: Time to move ahead from point A?

    PubMed Central

    Srivastava, Anurita; Datta, Niloy Ranjan

    2014-01-01

    Brachytherapy forms an integral part of the radiation therapy in cancer cervix. The dose prescription for intracavitary brachytherapy (ICBT) in cancer cervix is based on Tod and Meredith’s point A and has been in practice since 1938. This was proposed at a time when accessibility to imaging technology and dose computation facilities was limited. The concept has been in practice worldwide for more than half a century and has been the fulcrum of all ICBT treatments, strategies and outcome measures. The method is simple and can be adapted by all centres practicing ICBT in cancer cervix. However, with the widespread availability of imaging techniques, clinical use of different dose-rates, availability of a host of applicators fabricated with image compatible materials, radiobiological implications of dose equivalence and its impact on tumour and organs at risk; more and more weight is being laid down on individualised image based brachytherapy. Thus, computed tomography, magnetic-resonance imaging and even positron emission computerized tomography along with brachytherapy treatment planning system are being increasingly adopted with promising outcomes. The present article reviews the evolution of dose prescription concepts in ICBT in cancer cervix and brings forward the need for image based brachytherapy to evaluate clinical outcomes. As is evident, a gradual transition from “point” based brachytherapy to “profile” based image guided brachytherapy is gaining widespread acceptance for dose prescription, reporting and outcome evaluation in the clinical practice of ICBT in cancer cervix. PMID:25302176

  8. Bayesian inference of whole-organ deformation dynamics from limited space-time point data.

    PubMed

    Morishita, Yoshihiro; Suzuki, Takayuki

    2014-09-21

    To understand the morphogenetic mechanisms of organ development and regeneration, it is essential to clarify the inter-hierarchical relationship between microscopic, molecular/cellular activities and organ-level tissue deformation dynamics. While the former have been studied for several decades, the latter - macroscopic geometrical information about physical tissue deformation - is often missing, especially for many vertebrates. This is mainly because live recording of detailed cell behaviors in whole tissues during vertebrate organogenesis is technically difficult. In this study, we have developed a novel method that combines snapshot lineage tracing with Bayesian statistical estimation to construct whole-organ deformation maps from landmark data on limited numbers of space-time points. Following the validation of the method using artificially generated data sets, we applied it to the analysis of tissue deformation dynamics in chick limb development. A quantitative tissue deformation map for St.23-St.24 has been constructed, and its precision has been proven by evaluating its predictive performance. Geometrical analyses of the map have revealed a spatially heterogeneous volume growth pattern that is consistent with the expression pattern of a major morphogen and anisotropic tissue deformation along an axis. Thus, our method enables deformation dynamics analysis in organogenesis using practical lineage marking techniques.

  9. Improving BeiDou real-time precise point positioning with numerical weather models

    NASA Astrophysics Data System (ADS)

    Lu, Cuixian; Li, Xingxing; Zus, Florian; Heinkelmann, Robert; Dick, Galina; Ge, Maorong; Wickert, Jens; Schuh, Harald

    2017-02-01

    Precise positioning with the current Chinese BeiDou Navigation Satellite System is proven to be of comparable accuracy to the Global Positioning System, which is at centimeter level for the horizontal components and sub-decimeter level for the vertical component. But the BeiDou precise point positioning (PPP) shows its limitation in requiring a relatively long convergence time. In this study, we develop a numerical weather model (NWM) augmented PPP processing algorithm to improve BeiDou precise positioning. Tropospheric delay parameters, i.e., zenith delays, mapping functions, and horizontal delay gradients, derived from short-range forecasts from the Global Forecast System of the National Centers for Environmental Prediction (NCEP) are applied into BeiDou real-time PPP. Observational data from stations that are capable of tracking the BeiDou constellation from the International GNSS Service (IGS) Multi-GNSS Experiments network are processed, with the introduced NWM-augmented PPP and the standard PPP processing. The accuracy of tropospheric delays derived from NCEP is assessed against with the IGS final tropospheric delay products. The positioning results show that an improvement in convergence time up to 60.0 and 66.7% for the east and vertical components, respectively, can be achieved with the NWM-augmented PPP solution compared to the standard PPP solutions, while only slight improvement in the solution convergence can be found for the north component. A positioning accuracy of 5.7 and 5.9 cm for the east component is achieved with the standard PPP that estimates gradients and the one that estimates no gradients, respectively, in comparison to 3.5 cm of the NWM-augmented PPP, showing an improvement of 38.6 and 40.1%. Compared to the accuracy of 3.7 and 4.1 cm for the north component derived from the two standard PPP solutions, the one of the NWM-augmented PPP solution is improved to 2.0 cm, by about 45.9 and 51.2%. The positioning accuracy for the up component

  10. Ultra-Wideband Time-Difference-of-Arrival Two-Point-Tracking System

    NASA Technical Reports Server (NTRS)

    Ni, Jianjun David; Arndt, Dickey; Ngo, Phong; Phan, Chau; Dekome, Kent; Dusl, John

    2009-01-01

    A UWB TDOA Two-Point-Tracking System has been conceived and developed at JSC. This system can provide sub-inch tracking capability of two points on one target. This capability can be applied to guide a docking process in a 2D space. Lab tests demonstrate the feasibility of this technology.

  11. Common conversion point stacking of receiver functions versus passive source reverse time migration and wavefield regularization

    NASA Astrophysics Data System (ADS)

    Shang, Xuefeng; de Hoop, Maarten V.; van der Hilst, Robert D.

    2017-02-01

    We demonstrate with synthetic and field data that with sufficiently dense sampling wave-equation based methods such as reverse time migration (RTM), implicitly forming array receiver functions (ARFs), perform better resolution-wise than migration of common conversion point (CCP) stacks of traditional receiver functions. However, even with modern array deployments the sampling requirement is typically not met for teleseismic (earthquake) data. To enable RTM imaging with sparsely (and irregularly) sampled wavefields at the surface we use an intermediate reconstruction based on sparsity promoting optimization using a curvelet (or wave packet) representation of the data, as an important and necessary preprocessing step. To suppress artifacts, the curvelet coefficients are constrained to represent the range of known directions present in the data. We show that our proposed preprocessing procedure (which may be viewed as generating 'missing' traces) can produce artifact-free data for RTM even if only 20% of the necessary data is available in the original data set. With synthetic data we also demonstrate that if sampling criteria are not met, CCP can produce results that are superior over wave-equation methods such as RTM. As a proof-of-concept with field data we image the structure of the crust beneath the Himalayas with passive-source RTM of teleseismic data from the Hi-CLIMB project (Nábělek et al., 2005). For Hi-CLIMB data the CCP and RTM results are similar because sampling is still too sparse for RTM and because the structure is simple enough for successful CCP. Both results are both improved by wavefield regularization and reveal that the Moho is continuous beneath most of the array, and not fragmented as suggested by some earlier studies.

  12. Universal GFR determination based on two time points during plasma iohexol disappearance.

    PubMed

    Ng, Derek K S; Schwartz, George J; Jacobson, Lisa P; Palella, Frank J; Margolick, Joseph B; Warady, Bradley A; Furth, Susan L; Muñoz, Alvaro

    2011-08-01

    An optimal measurement of glomerular filtration rate (GFR) should minimize the number of blood draws, and reduce procedural invasiveness and the burden to study personnel and cost, without sacrificing accuracy. Equations have been proposed to calculate GFR from the slow compartment separately for adults and children. To develop a universal equation, we used 1347 GFR measurements from two diverse groups consisting of 527 men in the Multicenter AIDS Cohort Study and 514 children in the Chronic Kidney Disease in Children cohort. Both studies used nearly identical two-compartment (fast and slow) protocols to measure GFR. To estimate the fast component from markers of body size and of the slow component, we used standard linear regression methods with the log-transformed fast area as the dependent variable. The fast area could be accurately estimated from body surface area by a simple parameter (6.4/body surface area) with no residual dependence on the slow area or other markers of body size. Our equation measures only the slow iohexol plasma disappearance curve with as few as two time points and was normalized to 1.73 m2 body surface area. It is of the form: GFR=slowGFR/[1+0.12(slowGFR/100)]. In a random sample utilizing a third of the patients for validation, there was excellent agreement between the calculated and measured GFR with low root mean square errors being 4.6 and 1.5 ml/min per 1.73 m2 for adults and children, respectively. Thus, our proposed simple equation, developed in a combined patient group with a broad range of GFRs, may be applied universally and is independent of the injected amount of iohexol.

  13. GNSS related periodic signals in coordinate time-series from Precise Point Positioning

    NASA Astrophysics Data System (ADS)

    Abraha, K. E.; Teferle, F. N.; Hunegnaw, A.; Dach, R.

    2017-03-01

    In Global Navigation Satellite System (GNSS) coordinate time-series unrecognized errors and unmodelled (periodic) effects may bias nonlinear motions induced by geophysical signals. Hence, understanding and mitigating these errors is vital to reducing biases and on revealing subtle geophysical signals. To assess the nature of periodic signals in coordinate time-series Precise Point Positioning (PPP) solutions for the period 2008-2015 are generated. The solutions consider Global Positioning System (GPS), GLObalnaya NAvigatsionnaya Sputnikovaya Sistema (GLONASS) or combined GPS+GLONASS (GNSS) observations. We assess the periodic signals of station coordinates computed using the combined International GNSS Service (IGS) and four of its Analysis Centers (ACs) products. Furthermore, we make use of different filtering methods to investigate the sources of the periodic signals. A faint fortnightly signal in our PPP solution based on Jet Propulsion Laboratory (JPL) products and the existence of an 8 d period for those ACs generating combined GPS+GLONASS products are the main features in the GPS-only solutions. The existence of the 8 d period in the GPS-only solution indicates that GPS orbits computed in a combined GNSS solution contain GLONASS-specific signals. The GLONASS-only solution shows highly elevated powers at the third draconitic harmonic (˜120 d period), at the 8 d period and its harmonics (4 d, 2.67 d) besides the well-known annual, semi-annual and other draconitic harmonics. We show that the GLONASS constellation gaps before December 2011 contribute to the power at some of the frequencies. However, the well-known fortnightly signal in GPS-only solutions is not discernible in the GLONASS-only solution. The combined GNSS solution contains periodic signals from both systems, with most of the powers being reduced when compared to the single-GNSS solutions. A 52 per cent reduction for the horizontal components and a 36 per cent reduction for the vertical component

  14. Benefits of a Geosynchronous Orbit (GEO) Observation Point for Orbit Determination

    DTIC Science & Technology

    2011-09-01

    look “up” for GEO objects. This paper analyzes the potential benefits of a GEO observation point for performing metric observations that are...error covariance. 1. INTRODUCTION This paper analyzes the potential benefits of a GEO observation point for performing metric observations that...reporting burden for the collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching

  15. Stochastic modelling for biodosimetry: Predicting the chromosomal response to radiation at different time points after exposure

    NASA Astrophysics Data System (ADS)

    Deperas-Standylo, Joanna; Gudowska-Nowak, Ewa; Ritter, Sylvia

    2014-07-01

    Cytogenetic data accumulated from the experiments with peripheral blood lymphocytes exposed to densely ionizing radiation clearly demonstrate that for particles with linear energy transfer (LET) >100 keV/ μm the derived relative biological effectiveness (RBE) will strongly depend on the time point chosen for the analysis. A reasonable prediction of radiation-induced chromosome damage and its distribution among cells can be achieved by exploiting Monte Carlo methodology along with the information about the radius of the penetrating ion-track and the LET of the ion beam. In order to examine the relationship between the track structure and the distribution of aberrations induced in human lymphocytes and to clarify the correlation between delays in the cell cycle progression and the aberration burden visible at the first post-irradiation mitosis, we have analyzed chromosome aberrations in lymphocytes exposed to Fe-ions with LET values of 335 keV/ μm and formulated a Monte Carlo model which reflects time-delay in mitosis of aberrant cells. Within the model the frequency distributions of aberrations among cells follow the pattern of local energy distribution and are well approximated by a time-dependent compound Poisson statistics. The cell-division cycle of undamaged and aberrant cells and chromosome aberrations are modelled as a renewal process represented by a random sum of (independent and identically distributed) random elements S N = ∑ N i=0 X i . Here N stands for the number of particle traversals of cell nucleus, each leading to a statistically independent formation of X i aberrations. The parameter N is itself a random variable and reflects the cell cycle delay of heavily damaged cells. The probability distribution of S N follows a general law for which the moment generating function satisfies the relation Φ S N = Φ N ( Φ X i ). Formulation of the Monte Carlo model which allows to predict expected fluxes of aberrant and non-aberrant cells has been based

  16. Repeated diffusion MRI reveals earliest time point for stratification of radiotherapy response in brain metastases

    NASA Astrophysics Data System (ADS)

    Mahmood, Faisal; Johannesen, Helle H.; Geertsen, Poul; Hansen, Rasmus H.

    2017-04-01

    An imaging biomarker for early prediction of treatment response potentially provides a non-invasive tool for better prognostics and individualized management of the disease. Radiotherapy (RT) response is generally related to changes in gross tumor volume manifesting months later. In this prospective study we investigated the apparent diffusion coefficient (ADC), perfusion fraction and pseudo diffusion coefficient derived from diffusion weighted MRI as potential early biomarkers for radiotherapy response of brain metastases. It was a particular aim to assess the optimal time point for acquiring the DW-MRI scan during the course of treatment, since to our knowledge this important question has not been addressed directly in previous studies. Twenty-nine metastases (N  =  29) from twenty-one patients, treated with whole-brain fractionated external beam RT were analyzed. Patients were scanned with a 1 T MRI system to acquire DW-, T2*W-, T2W- and T1W scans, before start of RT, at each fraction and at follow up two to three months after RT. The DW-MRI parameters were derived using regions of interest based on high b-value images (b  =  800 s mm‑2). Both volumetric and RECIST criteria were applied for response evaluation. It was found that in non-responding metastases the mean ADC decreased and in responding metastases it increased. The volume based response proved to be far more consistently predictable by the ADC change found at fraction number 7 and later, compared to the linear response (RECIST). The perfusion fraction and pseudo diffusion coefficient did not show sufficient prognostic value with either response assessment criteria. In conclusion this study shows that the ADC derived using high b-values may be a reliable biomarker for early assessment of radiotherapy response for brain metastases patients. The earliest response stratification can be achieved using two DW-MRI scans, one pre-treatment and one at treatment day 7–9 (equivalent to 21

  17. Radioisotopic Tie Points of the Quaternary Geomagnetic Instability Time Scale (GITS): How Accurate and Precise?

    NASA Astrophysics Data System (ADS)

    Singer, B. S.

    2014-12-01

    Reversals and excursions of the geomagnetic field are recorded globally by sedimentary and volcanic rocks. These geodynamo instabilities provide a rich set of chronostratigraphic tie points for the Quaternary period that can provide tests of age models central to paleoclimate studies. Radioisotopic dating of volcanic rocks, mainly 40Ar/39Ar dating of lava flows, coupled with astronomically-dated deep sea sediments, reveals 10 polarity reversals and 27 field excursions during the Quaternary (Singer, 2014). A key question concerns the uncertainties associated with radioisotopic dates of those geodynamo instabilities that have been identified both in terrestrial volcanic rocks and in deep sea sediments. These particular features offer the highest confidence in linking 40Ar/39Ar dates to the global marine climate record. Geological issues aside, for rocks in which the build-up of 40Ar by decay of 40K may be overwhelmed by atmospheric 40Ar at the time of eruption, the uncertainty in 40Ar/39Ar dates derives from three sources: (1) analytical uncertainty associated with measurement of the isotopes; this is straightforward to estimate; (2) systematic uncertainties stemming from the age of standard minerals, such as the Fish Canyon sanidine, and in the 40K decay constant; and (3) systematic uncertainty introduced during analysis, mainly the size and reproducibility of procedural blanks. Whereas 1 and 2 control the precision of an age determination, 2 and 3 also control accuracy. In parallel with an astronomical calibration of 28.201 Ma for the Fish Canyon sanidine standard, awareness of the importance of procedural blanks, and a new generation multi-collector mass spectrometer capable of exceptionally low-blank and isobar-free analysis, are improving both accuracy and precision of 40Ar/39Ar dates. Results from lavas recording the Matuyama-Brunhes reversal, the Santa Rosa excursion, and the reversal at the top of the Cobb Mtn subchron demonstrate these advances. Current best

  18. Exact solution for a random walk in a time-dependent 1D random environment: the point-to-point Beta polymer

    NASA Astrophysics Data System (ADS)

    Thiery, Thimothée; Le Doussal, Pierre

    2017-01-01

    We consider the Beta polymer, an exactly solvable model of directed polymer on the square lattice, introduced by Barraquand and Corwin (BC) (2016 Probab. Theory Relat. Fields 1-16). We study the statistical properties of its point to point partition sum. The problem is equivalent to a model of a random walk in a time-dependent (and in general biased) 1D random environment. In this formulation, we study the sample to sample fluctuations of the transition probability distribution function (PDF) of the random walk. Using the Bethe ansatz we obtain exact formulas for the integer moments, and Fredholm determinant formulas for the Laplace transform of the directed polymer partition sum/random walk transition probability. The asymptotic analysis of these formulas at large time t is performed both (i) in a diffusive vicinity, x˜ {{t}1/2} , of the optimal direction (in space-time) chosen by the random walk, where the fluctuations of the PDF are found to be Gamma distributed; (ii) in the large deviations regime, x˜ t , of the random walk, where the fluctuations of the logarithm of the PDF are found to grow with time as t 1/3 and to be distributed according to the Tracy-Widom GUE distribution. Our exact results complement those of BC for the cumulative distribution function of the random walk in regime (ii), and in regime (i) they unveil a novel fluctuation behavior. We also discuss the crossover regime between (i) and (ii), identified as x˜ {{t}3/4} . Our results are confronted to extensive numerical simulations of the model.

  19. FUSING POINT AND AREAL LEVEL SPACE-TIME DATA WITH APPLICATION TO WET DEPOSITION

    EPA Science Inventory

    Motivated by the problem of predicting annual wet chemical deposition in the eastern United States, this paper develops a framework for joint modeling of point and grid referenced spatio-temporal data. The proposed hierarchical model is able to provide accurate spatial interpolat...

  20. Free-time and fixed end-point optimal control theory in quantum mechanics: application to entanglement generation.

    PubMed

    Mishima, K; Yamashita, K

    2009-01-21

    We have constructed free-time and fixed end-point optimal control theory for quantum systems and applied it to entanglement generation between rotational modes of two polar molecules coupled by dipole-dipole interaction. The motivation of the present work is to solve optimal control problems more flexibly by extending the popular fixed time and fixed end-point optimal control theory for quantum systems to free-time and fixed end-point optimal control theory. As a demonstration, the theory that we have constructed in this paper will be applied to entanglement generation in rotational modes of NaCl-NaBr polar molecular systems that are sensitive to the strength of entangling interactions. Our method will significantly be useful for the quantum control of nonlocal interaction such as entangling interaction, which depends crucially on the strength of the interaction or the distance between the two molecules, and other general quantum dynamics, chemical reactions, and so on.

  1. Free-time and fixed end-point optimal control theory in quantum mechanics: Application to entanglement generation

    NASA Astrophysics Data System (ADS)

    Mishima, K.; Yamashita, K.

    2009-01-01

    We have constructed free-time and fixed end-point optimal control theory for quantum systems and applied it to entanglement generation between rotational modes of two polar molecules coupled by dipole-dipole interaction. The motivation of the present work is to solve optimal control problems more flexibly by extending the popular fixed time and fixed end-point optimal control theory for quantum systems to free-time and fixed end-point optimal control theory. As a demonstration, the theory that we have constructed in this paper will be applied to entanglement generation in rotational modes of NaCl-NaBr polar molecular systems that are sensitive to the strength of entangling interactions. Our method will significantly be useful for the quantum control of nonlocal interaction such as entangling interaction, which depends crucially on the strength of the interaction or the distance between the two molecules, and other general quantum dynamics, chemical reactions, and so on.

  2. 40 CFR 51.905 - How do areas transition from the 1-hour NAAQS to the 1997 8-hour NAAQS and what are the anti...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... NAAQS to the 1997 8-hour NAAQS and what are the anti-backsliding provisions? 51.905 Section 51.905... National Ambient Air Quality Standard § 51.905 How do areas transition from the 1-hour NAAQS to the 1997 8... implement the applicable requirements as defined in § 51.900(f), except as provided in paragraph...

  3. Validation of a Single-Time-Point Measurement of Total Abdominal Counts to Simplify Small Bowel and Colon Transit Analyses.

    PubMed

    Maurer, Alan H; Parupalli, Rahul; Orthey, Perry; Parkman, Henry P

    2016-12-01

    The Society of Nuclear Medicine and Molecular Imaging and European Association of Nuclear Medicine procedure guide on gastrointestinal transit currently indicates that the mean of total abdominal counts of 7 time points (0-360 min) is used to define the total abdominal counts for bowel transit studies. The purpose of this study was to investigate the variability of total abdominal counts during the initial 6 h of bowel transit and to determine whether a simplified, single-time-point measurement can be used.

  4. Different RAN Components Relate to Reading at Different Points in Time

    ERIC Educational Resources Information Center

    Georgiou, George K.; Papadopoulos, Timothy C.; Kaizer, Eleni L.

    2014-01-01

    The present 10-year longitudinal study examined how rapid automatized naming (RAN) components--articulation time and pause time--relate to reading fluency. Seventy-five Greek-speaking children were followed from Grade 1 to Grade 10 and were assessed five times (in Grades 1, 2, 4, 6, and 10) on RAN (digits and objects) and reading fluency (word…

  5. Atypical late-time singular regimes accurately diagnosed in stagnation-point-type solutions of 3D Euler flows

    NASA Astrophysics Data System (ADS)

    Mulungye, Rachel M.; Lucas, Dan; Bustamante, Miguel D.

    2016-02-01

    We revisit, both numerically and analytically, the finite-time blowup of the infinite-energy solution of 3D Euler equations of stagnation-point-type introduced by Gibbon et al. (1999). By employing the method of mapping to regular systems, presented in Bustamante (2011) and extended to the symmetry-plane case by Mulungye et al. (2015), we establish a curious property of this solution that was not observed in early studies: before but near singularity time, the blowup goes from a fast transient to a slower regime that is well resolved spectrally, even at mid-resolutions of $512^2.$ This late-time regime has an atypical spectrum: it is Gaussian rather than exponential in the wavenumbers. The analyticity-strip width decays to zero in a finite time, albeit so slowly that it remains well above the collocation-point scale for all simulation times $t < T^* - 10^{-9000}$, where $T^*$ is the singularity time. Reaching such a proximity to singularity time is not possible in the original temporal variable, because floating point double precision ($\\approx 10^{-16}$) creates a `machine-epsilon' barrier. Due to this limitation on the \\emph{original} independent variable, the mapped variables now provide an improved assessment of the relevant blowup quantities, crucially with acceptable accuracy at an unprecedented closeness to the singularity time: $T^*- t \\approx 10^{-140}.$

  6. Side Effects in Time Discounting Procedures: Fixed Alternatives Become the Reference Point

    PubMed Central

    2016-01-01

    Typical research on intertemporal choice utilizes a two-alternative forced choice (2AFC) paradigm requiring participants to choose between a smaller sooner and larger later payoff. In the adjusting-amount procedure (AAP) one of the alternatives is fixed and the other is adjusted according to particular choices made by the participant. Such a method makes the alternatives unequal in status and is speculated to make the fixed alternative a reference point for choices, thereby affecting the decision made. The current study shows that fixing different alternatives in the AAP influences discount rates in intertemporal choices. Specifically, individuals’ (N = 283) choices were affected to just the same extent by merely fixing an alternative as when choices were preceded by scenarios explicitly imposing reference points. PMID:27768759

  7. Side Effects in Time Discounting Procedures: Fixed Alternatives Become the Reference Point.

    PubMed

    Sawicki, Przemysław; Białek, Michał

    2016-01-01

    Typical research on intertemporal choice utilizes a two-alternative forced choice (2AFC) paradigm requiring participants to choose between a smaller sooner and larger later payoff. In the adjusting-amount procedure (AAP) one of the alternatives is fixed and the other is adjusted according to particular choices made by the participant. Such a method makes the alternatives unequal in status and is speculated to make the fixed alternative a reference point for choices, thereby affecting the decision made. The current study shows that fixing different alternatives in the AAP influences discount rates in intertemporal choices. Specifically, individuals' (N = 283) choices were affected to just the same extent by merely fixing an alternative as when choices were preceded by scenarios explicitly imposing reference points.

  8. Dynamic contrast-enhanced magnetic resonance imaging of osseous spine metastasis before and 1 hour after high-dose image-guided radiation therapy.

    PubMed

    Lis, Eric; Saha, Atin; Peck, Kyung K; Zatcky, Joan; Zelefsky, Michael J; Yamada, Yoshiya; Holodny, Andrei I; Bilsky, Mark H; Karimi, Sasan

    2017-01-01

    OBJECTIVE High-dose image-guided radiation therapy (HD IGRT) has been instrumental in mitigating some limitations of conventional RT. The recent emergence of dynamic contrast-enhanced (DCE) MRI to investigate tumor physiology can be used to verify the response of human tumors to HD IGRT. The purpose of this study was to evaluate the near-immediate effects of HD IGRT on spine metastases through the use of DCE MRI perfusion studies. METHODS Six patients with spine metastases from prostate, thyroid, and renal cell carcinoma who underwent HD IGRT were studied using DCE MRI prior to and 1 hour after HD IGRT. The DCE perfusion parameters plasma volume (Vp) and vascular permeability (Ktrans) were measured to assess the near-immediate and long-term tumor response. A Mann-Whitney U-test was performed to compare significant changes (at p ≤ 0.05) in perfusion parameters before and after RT. RESULTS The authors observed a precipitous drop in Vp within 1 hour of HD IGRT, with a mean decrease of 65.2%. A significant difference was found between Vp values for before and 1 hour after RT (p ≤ 0.05). No significant change was seen in Vp (p = 0.31) and Ktrans (p = 0.1) from 1 hour after RT to the first follow-up. CONCLUSIONS The data suggest that there is an immediate effect of HD IGRT on the vascularity of spine metastases, as demonstrated by a precipitous decrease in Vp. The DCE MRI studies can detect such changes within 1 hour after RT, and findings are concordant with existing animal models.

  9. Real-time 2D floating-point fast Fourier transforms for seeker simulation

    NASA Astrophysics Data System (ADS)

    Chamberlain, Richard; Lord, Eric; Shand, David J.

    2002-07-01

    The floating point Fast Fourier Transform (FFT) is one of the most useful basic functions available to the image and signal processing engineer allowing many complex and detailed special functions to be implemented more simply in the frequency domain. In the Hardware-in-the-Loop field an image transformed using FFT would allow the designer to think about accurate frequency based simulation of seeker lens effects, motion blur, detector transfer functions and much more. Unfortunately, the transform requires many hundreds of thousands or millions of floating point operations on a single modest sized image making it impractical for realtime Hardware-in-the-Loop systems. .until now. This paper outlines the development, by Nallatech, of an FPGA based IEEE floating point core. It traces the subsequent use of this core to develop a full 256 X 256 FFT and filter process implemented on COTS hardware at frame rates up to 150Hz. This transform can be demonstrated to model optical transfer functions at a far greater accuracy than the current spatial models. Other applications and extensions of this technique will be discussed such as filtering for image tracking algorithms and in the simulation of radar processing in the frequency domain.

  10. Temperature dependence of the point defect properties of GaN thin films studied by terahertz time-domain spectroscopy

    NASA Astrophysics Data System (ADS)

    Fang, HeNan; Zhang, Rong; Liu, Bin; Li, YeCao; Fu, DeYi; Li, Yi; Xie, ZiLi; Zhuang, Zhe; Zheng, YouDou; Wu, JingBo; Jin, BiaoBing; Chen, Jian; Wu, PeiHeng

    2013-11-01

    The dielectric functions of GaN for the temperature and frequency ranges of 10-300 K and 0.3-1 THz are obtained using terahertz time-domain spectroscopy. It is found that there are oscillations of the dielectric functions at various temperatures. Physically, the oscillation behavior is attributed to the resonance states of the point defects in the material. Furthermore, the dielectric functions are well fitted by the combination of the simple Drude model together with the classical damped oscillator model. According to the values of the fitting parameters, the concentration and electron lifetime of the point defects for various temperatures are determined, and the temperature dependences of them are in accordance with the previously reported result. Therefore, terahertz time-domain spectroscopy can be considered as a promising technique for investigating the relevant characteristics of the point defects in semiconductor materials.

  11. Time Series Discord Detection in Medical Data using a Parallel Relational Database [PowerPoint

    SciTech Connect

    Woodbridge, Diane; Wilson, Andrew T.; Rintoul, Mark Daniel; Goldstein, Richard H.

    2015-11-01

    Recent advances in sensor technology have made continuous real-time health monitoring available in both hospital and non-hospital settings. Since data collected from high frequency medical sensors includes a huge amount of data, storing and processing continuous medical data is an emerging big data area. Especially detecting anomaly in real time is important for patients’ emergency detection and prevention. A time series discord indicates a subsequence that has the maximum difference to the rest of the time series subsequences, meaning that it has abnormal or unusual data trends. In this study, we implemented two versions of time series discord detection algorithms on a high performance parallel database management system (DBMS) and applied them to 240 Hz waveform data collected from 9,723 patients. The initial brute force version of the discord detection algorithm takes each possible subsequence and calculates a distance to the nearest non-self match to find the biggest discords in time series. For the heuristic version of the algorithm, a combination of an array and a trie structure was applied to order time series data for enhancing time efficiency. The study results showed efficient data loading, decoding and discord searches in a large amount of data, benefiting from the time series discord detection algorithm and the architectural characteristics of the parallel DBMS including data compression, data pipe-lining, and task scheduling.

  12. Time-Transient Characteristics of a Point-Contact-Type Peltier Device

    NASA Astrophysics Data System (ADS)

    Anzai, Toru; Yamaguchi, Shigeo

    We proposed a new type of Peltier device, and succeeded in the fabrication of the device, which we call a point-contact-type sandwich-structure (PCS). A micro-object can be cooled or heated using our fabricated device. The tip was cooled through the Peltier effect, and a tip temperature of -36.3°C was achieved at a current of 28 A. When current was reversed, the tip was heated and the maximum tip temperature was 251.5°C at a current of 20 A. The PCS Peltier device can be useful in medical treatment and bioelectronics.

  13. Multiple length and time scales of dynamic heterogeneities in model glass-forming liquids: a systematic analysis of multi-point and multi-time correlations.

    PubMed

    Kim, Kang; Saito, Shinji

    2013-03-28

    We report an extensive and systematic investigation of the multi-point and multi-time correlation functions to reveal the spatio-temporal structures of dynamic heterogeneities in glass-forming liquids. Molecular dynamics simulations are carried out for the supercooled states of various prototype models of glass-forming liquids such as binary Kob-Andersen, Wahnström, soft-sphere, and network-forming liquids. While the first three models act as fragile liquids exhibiting super-Arrhenius temperature dependence in their relaxation times, the last is a strong glass-former exhibiting Arrhenius behavior. First, we quantify the length scale of the dynamic heterogeneities utilizing the four-point correlation function. The growth of the dynamic length scale with decreasing temperature is characterized by various scaling relations that are analogous to the critical phenomena. We also examine how the growth of the length scale depends upon the model employed. Second, the four-point correlation function is extended to a three-time correlation function to characterize the temporal structures of the dynamic heterogeneities based on our previous studies [K. Kim and S. Saito, Phys. Rev. E 79, 060501(R) (2009); and J. Chem. Phys. 133, 044511 (2010)]. We provide comprehensive numerical results obtained from the three-time correlation function for the above models. From these calculations, we examine the time scale of the dynamic heterogeneities and determine the associated lifetime in a consistent and systematic way. Our results indicate that the lifetime of the dynamical heterogeneities becomes much longer than the α-relaxation time determined from a two-point correlation function in fragile liquids. The decoupling between the two time scales is remarkable, particularly in supercooled states, and the time scales differ by more than an order of magnitude in a more fragile liquid. In contrast, the lifetime is shorter than the α-relaxation time in tetrahedral network-forming strong

  14. The Effects of Part-Time Employment on High School Students' Grade Point Averages and Rate of School Attendance.

    ERIC Educational Resources Information Center

    Heffez, Jack

    To determine what effects employment will have on high school students' grade point averages and rate of school attendance, the author involved fifty-six students in an experiment. Twenty-eight students were employed part-time under the Youth Incentive Entitlement Project (YIEP). The twenty-eight students in the control group were eligible for…

  15. The Use and Abuse of Part-Time Faculty: The Part-Timers' Point of View.

    ERIC Educational Resources Information Center

    Wilson, Wendy L.

    Problems faced by part-time faculty members are identified, and suggestions to avoid mistreatment of these teachers are offered. Disadvantages of part-time teaching include the lack of equitable pay and benefits. Since most institutions have a standard pay rate for part-timers, it is suggested that teaching excellence be recognized by creating…

  16. Prothrombin time and activated partial thromboplastin time using a point-of-care analyser (Abaxis VSpro®) in Bennett's wallabies (Macropus rufogriseus).

    PubMed

    Nevitt, B N; Chinnadurai, S K; Watson, M K; Langan, J N; Adkesson, M J

    2016-10-01

    There are few reports of coagulation times in marsupial species. Blood samples collected from 14 Bennett's wallabies (Macropus rufogriseus) under anaesthesia during routine health assessments were analysed for prothrombin time (PT) and activated partial thromboplastin time (aPTT) using a point-of-care analyser (POC) (Abaxis VSPro®). The wallabies had an aPTT mean of 78.09 s and median of 78.1 s. The PT for all wallabies was greater than 35 s, exceeding the longest time measured on the POC. Although PT was significantly longer, aPTT was similar to the manufacturer's domestic canine reference range.

  17. A zero-crossing point locking system in the time-of-flight measurement of femtosecond pulsed laser

    NASA Astrophysics Data System (ADS)

    Li, Shuyi; Zhao, Chunbo; Wu, Tengfei; Han, Jibo

    2016-10-01

    The background and principle of zero-crossing point locking technology are introduced in this paper. An experimental locking system is designed to realize fast locking of zero-crossing point, and the results of locking is studied by analyzing zero-crossing point locking signal. In the distance measurement of femtosecond pulsed laser, a crystal produces the balanced cross-correlation (BCC) signal, which signifies the time offset of the target pulses with respect to the reference pulses. By continuously pulling this signal to zero-crossing point, the locking system provides a closed loop control process, which ensures the stability of the zero-crossing point and the precision of measurement. This locking system is mainly made up by five sections. As a core section of system, P-I circuit can optimize the locking state by changing parameters. A frequency counter referenced to the rubidium atomic clock is used to measure the pulse repetition rate with a stability of 10-12 in the sampling rate of 10s in 24 hours, which is helpful to analyze the measurement precision. In the experiment, the result of zero-crossing point lock can reach to 15mV, in other words, the range of amplitude variation can be reduced to less than 15mV after locking. With the repetition rate data evaluated, the jitter of the pulse repetition rate is within 25Hz in the sampling time of 15s after locking the zero-crossing point. It is proved that the locking system designed has a high practical value in the distance and vibration measurement of femtosecond pulsed laser.

  18. GPS Carrier-Phase Time and Frequency Transfer With Different Versions of Precise Point Positioning Software

    DTIC Science & Technology

    2008-12-01

    standards at PTB. For this reason, a Dicom GTR50 time and frequency transfer receiver has been combined with a transportable passive hydrogen maser...comparisons described in this paper have been done with Dicom GTR50 time and frequency transfer receivers. The receiver is based on the Javad GGD...software. Figure 1. The Dicom GTR50 receiver and its mode of operation. In this setup, the precision of the results is limited by the

  19. A hierarchical model combining distance sampling and time removal to estimate detection probability during avian point counts

    USGS Publications Warehouse

    Amundson, Courtney L.; Royle, J. Andrew; Handel, Colleen M.

    2014-01-01

    Imperfect detection during animal surveys biases estimates of abundance and can lead to improper conclusions regarding distribution and population trends. Farnsworth et al. (2005) developed a combined distance-sampling and time-removal model for point-transect surveys that addresses both availability (the probability that an animal is available for detection; e.g., that a bird sings) and perceptibility (the probability that an observer detects an animal, given that it is available for detection). We developed a hierarchical extension of the combined model that provides an integrated analysis framework for a collection of survey points at which both distance from the observer and time of initial detection are recorded. Implemented in a Bayesian framework, this extension facilitates evaluating covariates on abundance and detection probability, incorporating excess zero counts (i.e. zero-inflation), accounting for spatial autocorrelation, and estimating population density. Species-specific characteristics, such as behavioral displays and territorial dispersion, may lead to different patterns of availability and perceptibility, which may, in turn, influence the performance of such hierarchical models. Therefore, we first test our proposed model using simulated data under different scenarios of availability and perceptibility. We then illustrate its performance with empirical point-transect data for a songbird that consistently produces loud, frequent, primarily auditory signals, the Golden-crowned Sparrow (Zonotrichia atricapilla); and for 2 ptarmigan species (Lagopus spp.) that produce more intermittent, subtle, and primarily visual cues. Data were collected by multiple observers along point transects across a broad landscape in southwest Alaska, so we evaluated point-level covariates on perceptibility (observer and habitat), availability (date within season and time of day), and abundance (habitat, elevation, and slope), and included a nested point

  20. Reaction time and movement duration influence on end point accuracy in a fast reaching task.

    PubMed

    Skurvidas, A; Mickevichiene, D; Cesnavichiene, V; Gutnik, B; Nash, D

    2012-01-01

    In labor and sport physiology a great deal of interest concerns the conceptual model of governance of both rapid and precise target-directed movements. Widely known in the theory of motor control, Fitts' paradigm determines the time of motion, calculated from the distance to the target and the diameter of the target. However this paradigm does not take into account the time of preparation for movement, which can have a significant impact on accuracy. In addition, the literature highlights little evidence of temporal and spatial asymmetry in the production of fast and accurate movements. The aim of our work was to investigate the influence of the duration of the preparatory phase (reaction time - T(R)) and duration of protractile motion of the arm (T(M)) on the speed and accuracy of movement. Also, the in-dividual asymmetry of the temporal characteristics and accuracy of performance of movements were studied. We measured three aspects of translational motion of the arm to the computerized target: reaction time (T(R), s), time of motion of the arm (T(M), s), and error in the achievement of the target (deltaL, mm). The group of participants consisted of 12 healthy, right-handed, untrained girls, each of whom completed 5 series of 10 discrete movements by each of the left and right arms. Mathematical analysis of the results revealed the existence of five models of performance. Each model was represented in the participant's performance with different probability. The combination of high speed and high precision when the arm moved towards the target was found only in model 5, which combines a long period of preparation for the movement (T(R)) and a short time of motion (T(M)). The probability of its occurrence in the untrained subjects was very low (2-3%). We suggest that it may be possible to develop special methods of training, geared towards the ability to increase the probability of appearance of this model. Asymmetry of motor action appeared clearly evident only in

  1. Atmospheric plume progression as a function of time and distance from the release point for radioactive isotopes

    SciTech Connect

    Eslinger, Paul W.; Bowyer, Ted W.; Cameron, Ian M.; Hayes, James C.; Miley, Harry S.

    2015-10-01

    The International Monitoring System contains up to 80 stations around the world that have aerosol and xenon monitoring systems designed to detect releases of radioactive materials to the atmosphere from nuclear tests. A rule of thumb description of plume concentration and duration versus time and distance from the release point is useful when designing and deploying new sample collection systems. This paper uses plume development from atmospheric transport modeling to provide a power-law rule describing atmospheric dilution factors as a function of distance from the release point.

  2. Timing readout in paper device for quantitative point-of-use hemin/G-quadruplex DNAzyme-based bioassays.

    PubMed

    Zhang, Yun; Fan, Jinlong; Nie, Jinfang; Le, Shangwang; Zhu, Wenyuan; Gao, Dong; Yang, Jiani; Zhang, Songbai; Li, Jianping

    2015-11-15

    This work describes a quantitative point-of-use hemin/G-quadruplex DNAzyme-based assay that integrates a simple timing detection motif with low-cost, portable microfluidic paper-based analytical devices (μPADs). The timing readout is based on the selective DNAzyme-mediated wettability change of paper from hydrophilicity to hydrophobicity. Its utility is well demonstrated with sensitive, specific detection of K(+) ion as a model analyte in artificial samples as well as real human serum samples. This new method only requires a ubiquitous cheap timer (or a cell phone with a timing function) to provide quantitative results. It could offer new opportunities for the development of more peroxidase-mimicking DNAzyme-based bioassays that are simple, affordable, portable, and operable by minimally-trained users for broad point-of-use applications especially in resource-poor settings.

  3. Drive time to cardiac rehabilitation: at what point does it affect utilization?

    PubMed Central

    2010-01-01

    Background A 30 minute drive time threshold has often been cited as indicative of accessible health services. Cardiac rehabilitation (CR) is a chronic disease management program designed to enhance and maintain cardiovascular health, and geographic barriers to utilization are often cited. The purpose of this study was to empirically test the drive time threshold for CR utilization. Methods A prospective study, using a multi-level design of coronary artery disease outpatients nested within 97 cardiologists. Participants completed a baseline sociodemographic survey, and reported CR referral, enrollment and participation in a second survey 9 months later. CR utilization was verified with CR sites. Geographic information systems were used to generate drive times at 60, 80 and 100% of the speed limit to the closest CR site from participants' homes, to take into consideration various traffic conditions. Bivariate analysis was used to test for differences in CR referral, enrollment and degree of participation by drive time. Logistic regression was used to test drive time increments where significant differences were found. Results Drive times were generated for 1209 outpatients. Overall, CR referral was verified for 523 (43.3%) outpatients, with verified enrollment for 444 (36.7%) participating in a mean of 86.4 ± 25.7% of prescribed sessions. There were significant differences in CR referral and enrollment by drive time (ps < .01), but not degree of participation. Logistic regression analysis (ps < .001) revealed that the drive time threshold at 80% of the posted speed limit for physician referral may be 60 minutes (OR = .26, 95% CI: 0.13-0.55), and the threshold for patient CR enrollment may also be 60 minutes (OR = .11, 95% CI: 0.04-0.33). Conclusions Physicians may be taking geography into consideration when referring patients to CR. Empirical consideration also reveals that patients are significantly less likely to enroll in CR where they must drive 60 minutes or

  4. Time delay of critical images of a point source near the gravitational lens fold-caustic

    NASA Astrophysics Data System (ADS)

    Alexandrov, A.; Zhdanov, V.

    2016-06-01

    Within the framework of the analytical theory of the gravitational lensing we derive asymptotic formula for the time delay of critical images of apoint source, which is situated near a fold-caustic. We found corrections of the first and second order in powers of a parameter, which describescloseness of the source to the caustic. Our formula modifies earlier result by Congdon, Keeton &Nordgren (MNRAS, 2008) obtained in zero-orderapproximation. We have proved the hypothesis put forward by these authors that the first-order correction to the relative time delay of two criticalmages is identically zero. The contribution of the corrections is illustrated in model example by comparison with exact expression.

  5. [Forestalling policy as a strategic objective of space biology and medicine at the present time point].

    PubMed

    Ushakov, I B

    2011-01-01

    The article ushers into the acrimonious debates about paths of innovative development and criticality of fundamental sciences in technological progress for Russia security, and breakthrough potential. Among the alternative routes of technical development are different forms of priority boost of growing points in which Russia has attained and held steadily the leading position occupying a prominent segment in the international division of labor. Space effort of Russia gives a model example of successful implementation of the national program and demonstrates leadership in this area of human activities. The article presents analysis of the factors and circumstances that predetermined the winning in the early, Gagarin's period of piloted space flights of the forefront position of the country as well as the vector of cosmonautics' advance for many years ahead Despite the host of issues with implementation of the ISS utilization program and planning of exploration missions to the Moon and Mars, the unique experience of preparations and carrying out investigations and tests with humans in space, the enormous groundwork in fundamental biomedical researches over the past 50 years of piloted flights allow optimistic prognosis of gaining headway with essentially new ambitious space projects. The key question is whether the forestalling policy of priority development of piloted cosmonautics as the most integrated and science intensive sector of innovation techniques will be realized. The answer will guide near- and long-term future of the space industry and, consequently, the fortune of national fundamental space sciences, space biomedicine being its part and parcel.

  6. The cryptococcal antigen lateral flow assay: A point-of-care diagnostic at an opportune time.

    PubMed

    Tang, Michele W; Clemons, Karl V; Katzenstein, David A; Stevens, David A

    2016-08-01

    Cryptococcal meningitis is a devastating HIV-related opportunistic infection, affecting nearly 1 million individuals and causing over 500 000 deaths each year. The burden of disease is greatest in sub-Saharan Africa and Southeast Asia, where cryptococcal disease is the most common cause of meningitis. Rapid, accurate and affordable diagnosis of cryptococcal disease has been lacking in many of the most heavily affected areas. Here, we review a point-of-care assay for cryptococcal disease, the dipstick-formatted cryptococcal antigen lateral flow assay (LFA) (IMMY, Norman, OK). In comparison to culture, the assay is 99.5% sensitive and 98% specific. In comparison to other commercially available tests for cryptococcal antigen, the LFA has equal or superior sensitivity and specificity in CSF, plasma and serum samples. We discuss potential applications for the use of the assay in resource-limited settings, including what is likely to be an important role of the LFA in screening for early cryptococcal infection before clinical disease and in evaluating pre-emptive treatment.

  7. Low-Dose-Rate Irradiation for 1 Hour Induces Protection Against Lethal Radiation Doses but Does Not Affect Life Span of DBA/2 Mice

    PubMed Central

    Altaner, Čestmír; Altanerova, Veronika; Ebbesen, Peter; Pettersen, Erik O.

    2016-01-01

    Prior findings showed that serum from DBA/2 mice that had been given whole-body irradiation for 1 hour at a low dose rate (LDR) of 30 cGy/h induced protection against radiation in reporter cells by a mechanism depending on transforming growth factor β3 and inducible nitric oxide synthase activity. In the present study, the effect of the 1 hour of LDR irradiation on the response of the preirradiated mice to a subsequent lethal dose and on the life span is examined. These DBA/2 mice were prime irradiated for 1 hour at 30 cGy/h. Two experiments with 9 and 9.5 Gy challenge doses given 6 weeks after priming showed increased survival in primed mice compared to unprimed mice followed up to 225 and 81 days after challenge irradiation, respectively. There was no overall significant difference in life span between primed and unprimed mice when no challenge irradiation was given. The males seemed to have a slight increase in lifespan after priming while the opposite was seen for the females. PMID:27867323

  8. [Multiple time scales analysis of spatial differentiation characteristics of non-point source nitrogen loss within watershed].

    PubMed

    Liu, Mei-bing; Chen, Xing-wei; Chen, Ying

    2015-07-01

    Identification of the critical source areas of non-point source pollution is an important means to control the non-point source pollution within the watershed. In order to further reveal the impact of multiple time scales on the spatial differentiation characteristics of non-point source nitrogen loss, a SWAT model of Shanmei Reservoir watershed was developed. Based on the simulation of total nitrogen (TN) loss intensity of all 38 subbasins, spatial distribution characteristics of nitrogen loss and critical source areas were analyzed at three time scales of yearly average, monthly average and rainstorms flood process, respectively. Furthermore, multiple linear correlation analysis was conducted to analyze the contribution of natural environment and anthropogenic disturbance on nitrogen loss. The results showed that there were significant spatial differences of TN loss in Shanmei Reservoir watershed at different time scales, and the spatial differentiation degree of nitrogen loss was in the order of monthly average > yearly average > rainstorms flood process. TN loss load mainly came from upland Taoxi subbasin, which was identified as the critical source area. At different time scales, land use types (such as farmland and forest) were always the dominant factor affecting the spatial distribution of nitrogen loss, while the effect of precipitation and runoff on the nitrogen loss was only taken in no fertilization month and several processes of storm flood at no fertilization date. This was mainly due to the significant spatial variation of land use and fertilization, as well as the low spatial variability of precipitation and runoff.

  9. Free-Time and Fixed End-Point Optimal Control Theory in Quantum Mechanics: Application to Entanglement Generation

    NASA Astrophysics Data System (ADS)

    Mishima, Kenji; Yamashita, Koichi

    2009-03-01

    We have constructed free-time and fixed end-point optimal control theory for quantum systems and applied it to entanglement generation between rotational modes of two polar molecules coupled by dipole-dipole interaction. The motivation of the present work is to solve optimal control problems more flexibly by extending the popular fixed-time and fixed end-point optimal control theory for quantum systems to free-time and fixed end-point optimal control theory. Our theory can not only achieve high transition probabilities but also determine exact temporal duration of the laser pulses. As a demonstration, our theory is applied to entanglement generation in rotational modes of NaCl-NaBr polar molecular systems that are sensitive to the strength of entangling interactions. Using the tailored laser pulses, we discuss the fidelity of entanglement distillation and quantum teleportation. Our method will significantly be useful for the quantum control of non-local interaction such as entangling interaction, and other time-sensitive general quantum dynamics, chemical reactions.

  10. Joint transfer of time and frequency signals and multi-point synchronization via fiber network

    NASA Astrophysics Data System (ADS)

    Nan, Cheng; Wei, Chen; Qin, Liu; Dan, Xu; Fei, Yang; You-Zhen, Gui; Hai-Wen, Cai

    2016-01-01

    A system of jointly transferring time signals with a rate of 1 pulse per second (PPS) and frequency signals of 10 MHz via a dense wavelength division multiplex-based (DWDM) fiber is demonstrated in this paper. The noises of the fiber links are suppressed and compensated for by a controlled fiber delay line. A method of calibrating and characterizing time is described. The 1PPS is synchronized by feed-forward calibrating the fiber delays precisely. The system is experimentally examined via a 110 km spooled fiber in laboratory. The frequency stabilities of the user end with compensation are 1.8×10-14 at 1 s and 2.0×10-17 at 104 s average time. The calculated uncertainty of time synchronization is 13.1 ps, whereas the direct measurement of the uncertainty is 12 ps. Next, the frequency and 1PPS are transferred via a metropolitan area optical fiber network from one central site to two remote sites with distances of 14 km and 110 km. The frequency stabilities of 14 km link reach 3.0×10-14 averaged in 1 s and 1.4×10-17 in 104 s respectively; and the stabilities of 110 km link are 8.3×10-14 and 1.7×10-17, respectively. The accuracies of synchronization are estimated to be 12.3 ps for the 14 km link and 13.1 ps for the 110 km link, respectively. Project supported by the National Natural Science Foundation of China (Grant No. 61405227).

  11. Real-time performance analysis of wireless multimedia networks based on partially observed multivariate point processes

    NASA Astrophysics Data System (ADS)

    Hortos, William S.

    2000-07-01

    Third-generation (3G) wireless networks will support integrated multimedia services based on a cellular extension of a packet-switched architecture using variants of the Internet protocol (IP). Services can be categorized as real- time and delay-sensitive, or non-real-time and delay- insensitive. Each call, arriving to or active within the network, carries demand for one or more services in parallel; each service type with a guaranteed quality of service (QoS). Admission of new calls to the wireless IP network (WIN) from the gateway of a wired network or from a mobile subscriber (MS) is allowed by call admission control procedures. Roaming of the MSs among the nodes of the WIN is controlled by handoff procedures between base stations (BSs), or BS controllers, and the MSs. Metrics such as the probabilities of call blocking and dropping, handoff transition time, processing latency of a call, throughput, and capacity are used to evaluate the performance of network control procedures. The metrics are directly related to the network resources required to provide the QoS for the integrated services.

  12. Deparaffination time: a crucial point in histochemical detection of tissue copper.

    PubMed

    Nemolato, Sonia; Serra, S; Saccani, S; Faa, G

    2008-01-01

    The search for a sensitive histochemical method for revealing tissue copper has been the object of many workers in the past. In spite of multiple methods available, the occurrence in clinical practice of negative histochemical stains, even in cases with high copper levels demonstrated by quantitative methods is very high.This study was aimed at verifying the role of technical variations in the sensitivity of the Timm method and, in particular, the role of the dewaxing time of paraffin sections. To this end, 15 liver specimens, 10 from patients affected by Wilson's disease and 5 newborn livers were fixed in 10% formalin, paraffin embedded and routinaly processed. Four 4-micron sections from each case were rinsed in xylene for 10, 20, 60 min, and for 24 hrs. All sections were stained with Timm's method. In 13 out of the 15 liver biopsies utilized in this study, the sensitivity of Timm's method in revealing copper deposits in liver cells appeared to be dependent on the dewaxing time. In two other cases, reactivity of copper granules to Timm solution did not change significantly with the different deparaffination times. The best results were obtained by rinsing sections in xylene for 24 hrs, the worst in sections treated with xylen for 10 minutes. In particular, in five cases of Wilson's disease, Timm stain applied to sections following ten minutes of xylene were completely negative, while copper granules were clearly evidenced in the same section following an overnight bath in xylene. Our data show that an overnight bath of paraffin sections in xylene may completely change the sensitivity of Timm stain in revealing copper deposits in the liver, relaunching copper histochemistry in the diagnosis of copper-related liver diseases.

  13. Solar glare hazard analysis tool on account of determined points of time

    SciTech Connect

    Ho, Clifford K; Sims, Cianan Alexander

    2014-09-23

    Technologies pertaining to determining when glare will be perceived by a hypothetical observer from a glare source and the intensity of glare that will be perceived by the hypothetical observer from the glare source are described herein. A first location of a potential source of solar glare is received, and a second location of the hypothetical observer is received. Based upon such locations, including respective elevations, and known positions of the sun over time, a determination as to when the hypothetical observer will perceive glare from the potential source of solar glare is made. Subsequently, an amount of irradiance entering the eye of the hypothetical observer is calculated to assess potential ocular hazards.

  14. Real-Time Point Positioning Performance Evaluation of Single-Frequency Receivers Using NASA's Global Differential GPS System

    NASA Technical Reports Server (NTRS)

    Muellerschoen, Ronald J.; Iijima, Byron; Meyer, Robert; Bar-Sever, Yoaz; Accad, Elie

    2004-01-01

    This paper evaluates the performance of a single-frequency receiver using the 1-Hz differential corrections as provided by NASA's global differential GPS system. While the dual-frequency user has the ability to eliminate the ionosphere error by taking a linear combination of observables, the single-frequency user must remove or calibrate this error by other means. To remove the ionosphere error we take advantage of the fact that the magnitude of the group delay in range observable and the carrier phase advance have the same magnitude but are opposite in sign. A way to calibrate this error is to use a real-time database of grid points computed by JPL's RTI (Real-Time Ionosphere) software. In both cases we evaluate the positional accuracy of a kinematic carrier phase based point positioning method on a global extent.

  15. Spinodals and critical point using short-time dynamics for a simple model of liquid.

    PubMed

    Loscar, Ernesto S; Ferrara, C Gastón; Grigera, Tomás S

    2016-04-07

    We have applied the short-time dynamics method to the gas-liquid transition to detect the supercooled gas instability (gas spinodal) and the superheated liquid instability (liquid spinodal). Using Monte Carlo simulation, we have obtained the two spinodals for a wide range of pressure in sub-critical and critical conditions and estimated the critical temperature and pressure. Our method is faster than previous approaches and allows studying spinodals without needing equilibration of the system in the metastable region. It is thus free of the extrapolation problems present in other methods, and in principle could be applied to systems such as glass-forming liquids, where equilibration is very difficult even far from the spinodal. We have also done molecular dynamics simulations, where we find the method again able to detect the both spinodals. Our results are compared with different previous results in the literature and show a good agreement.

  16. Multiple Time Courses of Vestibular Set-Point Adaptation Revealed by Sustained Magnetic Field Stimulation of the Labyrinth.

    PubMed

    Jareonsettasin, Prem; Otero-Millan, Jorge; Ward, Bryan K; Roberts, Dale C; Schubert, Michael C; Zee, David S

    2016-05-23

    A major focus in neurobiology is how the brain adapts its motor behavior to changes in its internal and external environments [1, 2]. Much is known about adaptively optimizing the amplitude and direction of eye and limb movements, for example, but little is known about another essential form of learning, "set-point" adaptation. Set-point adaptation balances tonic activity so that reciprocally acting, agonist and antagonist muscles have a stable platform from which to launch accurate movements. Here, we use the vestibulo-ocular reflex-a simple behavior that stabilizes the position of the eye while the head is moving-to investigate how tonic activity is adapted toward a new set point to prevent eye drift when the head is still [3, 4]. Set-point adaptation was elicited with magneto-hydrodynamic vestibular stimulation (MVS) by placing normal humans in a 7T MRI for 90 min. MVS is ideal for prolonged labyrinthine activation because it mimics constant head acceleration and induces a sustained nystagmus similar to natural vestibular lesions [5, 6]. The MVS-induced nystagmus diminished slowly but incompletely over multiple timescales. We propose a new adaptation hypothesis, using a cascade of imperfect mathematical integrators, that reproduces the response to MVS (and more natural chair rotations), including the gradual decrease in nystagmus as the set point changes over progressively longer time courses. MVS set-point adaptation is a biological model with applications to basic neurophysiological research into all types of movements [7], functional brain imaging [8], and treatment of vestibular and higher-level attentional disorders by introducing new biases to counteract pathological ones [9].

  17. Stable long-time semiclassical description of zero-point energy in high-dimensional molecular systems.

    PubMed

    Garashchuk, Sophya; Rassolov, Vitaly A

    2008-07-14

    Semiclassical implementation of the quantum trajectory formalism [J. Chem. Phys. 120, 1181 (2004)] is further developed to give a stable long-time description of zero-point energy in anharmonic systems of high dimensionality. The method is based on a numerically cheap linearized quantum force approach; stabilizing terms compensating for the linearization errors are added into the time-evolution equations for the classical and nonclassical components of the momentum operator. The wave function normalization and energy are rigorously conserved. Numerical tests are performed for model systems of up to 40 degrees of freedom.

  18. Multiple length and time scales of dynamic heterogeneities in model glass-forming liquids: A systematic analysis of multi-point and multi-time correlations

    NASA Astrophysics Data System (ADS)

    Kim, Kang; Saito, Shinji

    2013-03-01

    We report an extensive and systematic investigation of the multi-point and multi-time correlation functions to reveal the spatio-temporal structures of dynamic heterogeneities in glass-forming liquids. Molecular dynamics simulations are carried out for the supercooled states of various prototype models of glass-forming liquids such as binary Kob-Andersen, Wahnström, soft-sphere, and network-forming liquids. While the first three models act as fragile liquids exhibiting super-Arrhenius temperature dependence in their relaxation times, the last is a strong glass-former exhibiting Arrhenius behavior. First, we quantify the length scale of the dynamic heterogeneities utilizing the four-point correlation function. The growth of the dynamic length scale with decreasing temperature is characterized by various scaling relations that are analogous to the critical phenomena. We also examine how the growth of the length scale depends upon the model employed. Second, the four-point correlation function is extended to a three-time correlation function to characterize the temporal structures of the dynamic heterogeneities based on our previous studies [K. Kim and S. Saito, Phys. Rev. E 79, 060501-R (2009), 10.1103/PhysRevE.79.060501; K. Kim and S. Saito, J. Chem. Phys. 133, 044511 (2010), 10.1063/1.3464331]. We provide comprehensive numerical results obtained from the three-time correlation function for the above models. From these calculations, we examine the time scale of the dynamic heterogeneities and determine the associated lifetime in a consistent and systematic way. Our results indicate that the lifetime of the dynamical heterogeneities becomes much longer than the α-relaxation time determined from a two-point correlation function in fragile liquids. The decoupling between the two time scales is remarkable, particularly in supercooled states, and the time scales differ by more than an order of magnitude in a more fragile liquid. In contrast, the lifetime is shorter

  19. Maternal–Fetal Transfer of Domoic Acid in Rats at Two Gestational Time Points

    PubMed Central

    Maucher, Jennifer M.; Ramsdell, John S.

    2007-01-01

    Background and objectives Prenatal exposure to asymptomatic doses of domoic acid (DA) causes learning and memory deficits later in life; therefore, we sought to measure distribution of DA in maternal plasma and brain, prenatal brain, and amniotic fluid 1 hr after exposure, a time frame that normally encompasses acute seizure behavior. Methods Pregnant rats were given a single intravenous dose of DA (0.6 or 1.6 mg/kg body weight) at either gestational day (GD) 13 or GD20, which correspond to the beginning of rat embryo neurogenesis and the last day of gestation, respectively. Using a direct ELISA, dose-dependent levels of DA were detected in each sample matrix tested. Results An average of 6.6 and 14 ng DA/g brain tissue was found in GD13 and GD20 prenatal rats, respectively. Brain concentrations of DA in the GD13 prenates were identical to amniotic fluid levels, consistent with no restriction for DA to enter the GD13 prenatal brain. At GD20 the prenatal brain contained half the concentration of DA in the amniotic fluid, and was approximately half that found in the brain of the dams. After 1 hr, fetal brain and amniotic fluid contained between 1 and 5% of DA found in the maternal circulation. The amniotic fluid levels of DA in this study were also within the same range measured in stranded California sea lions that showed reproductive failure. Conclusions DA crosses the placenta, enters brain tissue of prenates, and accumulates in the amniotic fluid. Amniotic fluid appears to be a useful fluid to monitor DA exposure. PMID:18087593

  20. Adaptive marker-free registration using a multiple point strategy for real-time and robust endoscope electromagnetic navigation.

    PubMed

    Luo, Xiongbiao; Wan, Ying; He, Xiangjian; Mori, Kensaku

    2015-02-01

    Registration of pre-clinical images to physical space is indispensable for computer-assisted endoscopic interventions in operating rooms. Electromagnetically navigated endoscopic interventions are increasingly performed at current diagnoses and treatments. Such interventions use an electromagnetic tracker with a miniature sensor that is usually attached at an endoscope distal tip to real time track endoscope movements in a pre-clinical image space. Spatial alignment between the electromagnetic tracker (or sensor) and pre-clinical images must be performed to navigate the endoscope to target regions. This paper proposes an adaptive marker-free registration method that uses a multiple point selection strategy. This method seeks to address an assumption that the endoscope is operated along the centerline of an intraluminal organ which is easily violated during interventions. We introduce an adaptive strategy that generates multiple points in terms of sensor measurements and endoscope tip center calibration. From these generated points, we adaptively choose the optimal point, which is the closest to its assigned the centerline of the hollow organ, to perform registration. The experimental results demonstrate that our proposed adaptive strategy significantly reduced the target registration error from 5.32 to 2.59 mm in static phantoms validation, as well as from at least 7.58 mm to 4.71 mm in dynamic phantom validation compared to current available methods.

  1. Real time, TV-based, point-image quantizer and sorter

    DOEpatents

    Case, Arthur L.; Davidson, Jackson B.

    1976-01-01

    A device is provided for improving the vertical resolution in a television-based, two-dimensional readout for radiation detection systems such as are used to determine the location of light or nuclear radiation impinging a target area viewed by a television camera, where it is desired to store the data indicative of the centroid location of such images. In the example embodiment, impinging nuclear radiation detected in the form of a scintillation occurring in a crystal is stored as a charge image on a television camera tube target. The target is scanned in a raster and the image position is stored according to a corresponding vertical scan number and horizontal position number along the scan. To determine the centroid location of an image that may overlap a number of horizontal scan lines along the vertical axis of the raster, digital logic circuits are provided with at least four series-connected shift registers, each having 512 bit positions according to a selected 512 horizontal increment of resolutions along a scan line. The registers are shifted by clock pulses at a rate of 512 pulses per scan line. When an image or portion thereof is detected along a scan, its horizontal center location is determined and the present front bit is set in the first shift register and shifted through the registers one at a time for each horizontal scan. Each register is compared bit-by-bit with the preceding register to detect coincident set bit positions until the last scan line detecting a portion of the image is determined. Depending on the number of shift registers through which the first detection of the image is shifted, circuitry is provided to store the vertical center position of the event according to the number of shift registers through which the first detection of the event is shifted. Interpolation circuitry is provided to determine if the event centroid is between adjacent scan lines and stored in a vertical address accordingly. The horizontal location of the event

  2. How Feasible is Multiple Time Point Web-Based Data Collection with Individuals Experiencing Street Homelessness?

    PubMed

    Eyrich-Garg, Karin M; Moss, Shadiya L

    2017-01-19

    Three barriers investigators often encounter when conducting longitudinal work with homeless or other marginalized populations are difficulty tracking participants, high rates of no-shows for follow-up interviews, and high rates of loss to follow-up. Recent research has shown that homeless populations have substantial access to information technologies, including mobile devices and computers. These technologies have the potential both to make longitudinal data collection with homeless populations easier and to minimize some of these methodological challenges. This pilot study's purpose was to test whether individuals who were homeless and sleeping on the streets-the "street homeless"-would answer questions remotely through a web-based data collection system at regular "follow-up" intervals. We attempted to simulate longitudinal data collection in a condensed time period. Participants (N = 21) completed an in-person baseline interview. Each participant was given a remotely reloadable gift card. Subsequently, weekly for 8 weeks, participants were sent an email with a link to a SurveyMonkey questionnaire. Participants were given 48 h to complete each questionnaire. Data were collected about life on the streets, service use, community inclusion, substance use, and high-risk sexual behaviors. Ten dollars was remotely loaded onto each participant's gift card when they completed the questionnaire within the completion window. A substantial number of participants (67% of the total sample and 86% of the adjusted sample) completed at least seven out of the eight follow-up questionnaires. Most questionnaires were completed at public libraries, but several were completed at other types of locations (social service agencies, places of employment, relative/friend/acquaintance's domiciles, or via mobile phone). Although some of the questions were quite sensitive, very few participants skipped any questions. The only variables associated with questionnaire completion were

  3. An Efficient Real-Time Precise Point Positioning (RT-PPP) Solution for Offshore Surveys in Turkey

    NASA Astrophysics Data System (ADS)

    Abdelazeem, Mohamed; Nurhan Çelik, Rahmi

    2016-07-01

    Recently, the international global navigation satellite systems (GNSS) service (IGS) has launched the real-time service (IGS-RTS). The IGS-RTS has shown promise accuracy in precise point positioning applications. Currently, the precise point positioning technique is used extensively in marine applications. In this study, we evaluate the accuracy of the real-time precise point positioning (RT-PPP) solution using the IGS-RTS for offshore surveys in Turkey. Dual-frequency GPS data is collected onboard a vessel and then processed using the Bernese 5.2 PPP module. The IGS-RTS precise orbit and clock products are used in order to account for the satellite orbit and clock products. To investigate the accuracy of the RT-PPP technique, the positioning accuracy is assessed and compared with the traditional double-difference solution. It is shown that the RT-PPP solution has good agreement with the double-difference solution. Also, the proposed solution efficiently fulfills the international maritime organization (IMO) standards for the offshore surveys.

  4. Time-dependent Monte Carlo simulations of critical and Lifshitz points of the axial-next-nearest-neighbor Ising model.

    PubMed

    da Silva, Roberto; Alves, Nelson; Drugowich de Felício, Jose Roberto

    2013-01-01

    In this work, we study the critical behavior of second-order points, specifically the Lifshitz point (LP) of a three-dimensional Ising model with axial competing interactions [the axial-next-nearest-neighbor Ising (ANNNI) model], using time-dependent Monte Carlo simulations. We use a recently developed technique that helps us localize the critical temperature corresponding to the best power law for magnetization decay over time: (m(0)=1)~t(-β/νz), which is expected of simulations starting from initially ordered states. We obtain original results for the dynamic critical exponent z, evaluated from the behavior of the ratio F(2)(t)=(m(0)=0)/(2)(m(0)=1)~t(3/z), along the critical line up to the LP. We explore all the critical exponents of the LP in detail, including the dynamic critical exponent θ that characterizes the initial slip of magnetization and the global persistence exponent θ(g) associated with the probability P(t) that magnetization keeps its signal up to time t. Our estimates for the dynamic critical exponents at the Lifshitz point are z=2.34(2) and θ(g)=0.336(4), values that are very different from those of the three-dimensional Ising model (the ANNNI model without the next-nearest-neighbor interactions at the z axis, i.e., J(2)=0), i.e., z≈2.07 and θ(g)≈0.38. We also present estimates for the static critical exponents β and ν, obtained from extended time-dependent scaling relations. Our results for static exponents are in good agreement with previous works.

  5. Analysis of PolSK based FSO system using wavelength and time diversity over strong atmospheric turbulence with pointing errors

    NASA Astrophysics Data System (ADS)

    Prabu, K.; Cheepalli, Shashidhar; Kumar, D. Sriram

    2014-08-01

    Free space optics (FSO) or wireless optical communication systems is an evolving alternative to the current radio frequency (RF) links due to its high and secure datarates, large license free bandwidth access, ease of installation, and lower cost for shorter range distances. These systems are largely influenced by atmospheric conditions due to wireless transmission; requirement of line of sight (LOS) propagation may lead to alignment problems in turn pointing errors. In this paper, we consider atmospheric turbulence and pointing errors are the major limitations. We tried to address these difficulties by considering polarization shift keying (PolSK) modulated FSO communication system with wavelength and time diversity. We derived the closed form expressions for estimation of the average bit error rate (BER) and outage probability, which are vital system performance metrics. Analytical results are shown considering different practical cases.

  6. Time-Point Dependent Activation of Autophagy and the UPS in SOD1G93A Mice Skeletal Muscle

    PubMed Central

    Oliván, Sara; Calvo, Ana Cristina; Gasco, Samanta; Muñoz, María Jesús; Zaragoza, Pilar; Osta, Rosario

    2015-01-01

    Amyotrophic Lateral Sclerosis (ALS) is a fatal neurodegenerative disease characterized by a selective loss of motor neurons together with a progressive muscle weakness. Albeit the pathophysiological mechanisms of the disease remain unknown, growing evidence suggests that skeletal muscle can be a target of ALS toxicity. In particular, the two main intracellular degradation mechanisms, autophagy and the ubiquitin-proteasome degradative system (UPS) have been poorly studied in this tissue. In this study we investigated the activation of autophagy and the UPS as well as apoptosis in the skeletal muscle from SOD1G93A mice along disease progression. Our results showed a significant upregulation of proteasome activity at early symptomatic stage, while the autophagy activation was found at presymptomatic and terminal stages. The mRNA upregulated levels of LC3, p62, Beclin1, Atg5 and E2f1 were only observed at symptomatic and terminal stages, which reinforced the time-point activation of autophagy. Furthermore, no apoptosis activation was observed along disease progression. The combined data provided clear evidence for the first time that there is a time-point dependent activation of autophagy and UPS in the skeletal muscle from SOD1G93A mice. PMID:26244336

  7. Recurrence network-based time series analysis for identifying tipping points in Plio-Pleistocene African climate

    NASA Astrophysics Data System (ADS)

    Donges, J. F.; Donner, R. V.; Trauth, M. H.; Marwan, N.; Schellnhuber, H. J.; Kurths, J.

    2012-04-01

    The analysis of paleoclimate time series is usually affected by severe methodological problems, resulting primarily from non-equidistant sampling and uncertain age models. As an alternative to existing methods of time series analysis, the statistical properties of recurrence networks are promising candidates for characterizing a system's nonlinear dynamics and quantifying structural changes in its reconstructed phase space as time evolves. The results of recurrence network analysis are robust under changes in the age model and are not directly affected by non-equidistant sampling of the data. Specifically, we investigate three marine records of African climate variability during the Plio-Pleistocene. We detect several statistically significant dynamical transitions or tipping points and show that the obtained results are qualitatively robust under changes of the relevant parameters of our method, including detrending, size of the running window used for analysis, and embedding delay. Finally, relating the identified tipping points in paleoclimate-variability to speciation and extinction events in the available fossil record of human ancestors contributes to the understanding of climatic mechanisms driving human evolution in Africa during the past 5 million years.

  8. Numerical study and ex vivo assessment of HIFU treatment time reduction through optimization of focal point trajectory

    NASA Astrophysics Data System (ADS)

    Grisey, A.; Yon, S.; Pechoux, T.; Letort, V.; Lafitte, P.

    2017-03-01

    Treatment time reduction is a key issue to expand the use of high intensity focused ultrasound (HIFU) surgery, especially for benign pathologies. This study aims at quantitatively assessing the potential reduction of the treatment time arising from moving the focal point during long pulses. In this context, the optimization of the focal point trajectory is crucial to achieve a uniform thermal dose repartition and avoid boiling. At first, a numerical optimization algorithm was used to generate efficient trajectories. Thermal conduction was simulated in 3D with a finite difference code and damages to the tissue were modeled using the thermal dose formula. Given an initial trajectory, the thermal dose field was first computed, then, making use of Pontryagin's maximum principle, the trajectory was iteratively refined. Several initial trajectories were tested. Then, an ex vivo study was conducted in order to validate the efficicency of the resulting optimized strategies. Single pulses were performed at 3MHz on fresh veal liver samples with an Echopulse and the size of each unitary lesion was assessed by cutting each sample along three orthogonal planes and measuring the dimension of the whitened area based on photographs. We propose a promising approach to significantly shorten HIFU treatment time: the numerical optimization algorithm was shown to provide a reliable insight on trajectories that can improve treatment strategies. The model must now be improved in order to take in vivo conditions into account and extensively validated.

  9. On some testable conditions for excitability and transparency of a class of time-delay systems with point delays

    NASA Astrophysics Data System (ADS)

    De la Sen, M.

    2009-11-01

    This article is concerned with the excitability of positive linear time-invariant systems subject to internal point delays. It is proved that the excitability independent of delay is guaranteed if an auxiliary delay-free system is excitable. Necessary and sufficient conditions for excitability and transparency are formulated in terms of the parameterization of the dynamics and control matrices and, equivalently, in terms of strict positivity of a matrix of an associate system obtained from the influence graph of the original system. Such conditions are testable through simple algebraic tests involving moderate computational effort.

  10. The effects of arm movement on reaction time in patients with latent and active upper trapezius myofascial trigger point

    PubMed Central

    Yassin, Marzieh; Talebian, Saeed; Ebrahimi Takamjani, Ismail; Maroufi, Nader; Ahmadi, Amir; Sarrafzadeh, Javad; Emrani, Anita

    2015-01-01

    Background: Myofascial pain syndrome is a significant source of mechanical pain. The aim of this study was to investigate the effects of arm movement on reaction time in females with latent and active upper trapezius myofascial trigger point. Methods: In this interventional study, a convenience sample of fifteen women with one active MTP, fifteen women with one latent MTP in the upper trapezius, and fifteen normal healthy women were participated. Participants were asked to stand for 10 seconds in an erect standing position. Muscle reaction times were recorded including anterior deltoid (AD), cervical paraspinal (CP) lumbar paraspinal (LP), both of upper trapezius (UT), sternocleidomastoid (SCM) and medial head of gastrocnemius (GcM). Participants were asked to flex their arms in response to a sound stimulus preceded by a warning sound stimulus. Data were analyzed using one-way ANOVA Test. Results: There was significant differences in motor time and reaction time between active and control groups (p< 0.05) except for GcM. There was no significant difference in motor time between active and passive groups except for UT without MTP and SCM (p< 0.05). Also, there were no significant differences in motor times between latent MTP and control groups. Furthermore, there was no significant difference in premotor times between the three groups. Conclusion: The present study shows that patients with active MTP need more time to react to stimulus, but patients with latent MTP are similar to healthy subjects in the reaction time. Patients with active MTP had less compatibility with environmental stimulations, and they responded to a specific stimulation with variability in Surface Electromyography (SEMG). PMID:26913258

  11. A Time Scheduling Model of Logistics Service Supply Chain Based on the Customer Order Decoupling Point: A Perspective from the Constant Service Operation Time

    PubMed Central

    Yang, Yi; Xu, Haitao; Liu, Xiaoyan; Wang, Yijia; Liang, Zhicheng

    2014-01-01

    In mass customization logistics service, reasonable scheduling of the logistics service supply chain (LSSC), especially time scheduling, is benefit to increase its competitiveness. Therefore, the effect of a customer order decoupling point (CODP) on the time scheduling performance should be considered. To minimize the total order operation cost of the LSSC, minimize the difference between the expected and actual time of completing the service orders, and maximize the satisfaction of functional logistics service providers, this study establishes an LSSC time scheduling model based on the CODP. Matlab 7.8 software is used in the numerical analysis for a specific example. Results show that the order completion time of the LSSC can be delayed or be ahead of schedule but cannot be infinitely advanced or infinitely delayed. Obtaining the optimal comprehensive performance can be effective if the expected order completion time is appropriately delayed. The increase in supply chain comprehensive performance caused by the increase in the relationship coefficient of logistics service integrator (LSI) is limited. The relative concern degree of LSI on cost and service delivery punctuality leads to not only changes in CODP but also to those in the scheduling performance of the LSSC. PMID:24715818

  12. A time scheduling model of logistics service supply chain based on the customer order decoupling point: a perspective from the constant service operation time.

    PubMed

    Liu, Weihua; Yang, Yi; Xu, Haitao; Liu, Xiaoyan; Wang, Yijia; Liang, Zhicheng

    2014-01-01

    In mass customization logistics service, reasonable scheduling of the logistics service supply chain (LSSC), especially time scheduling, is benefit to increase its competitiveness. Therefore, the effect of a customer order decoupling point (CODP) on the time scheduling performance should be considered. To minimize the total order operation cost of the LSSC, minimize the difference between the expected and actual time of completing the service orders, and maximize the satisfaction of functional logistics service providers, this study establishes an LSSC time scheduling model based on the CODP. Matlab 7.8 software is used in the numerical analysis for a specific example. Results show that the order completion time of the LSSC can be delayed or be ahead of schedule but cannot be infinitely advanced or infinitely delayed. Obtaining the optimal comprehensive performance can be effective if the expected order completion time is appropriately delayed. The increase in supply chain comprehensive performance caused by the increase in the relationship coefficient of logistics service integrator (LSI) is limited. The relative concern degree of LSI on cost and service delivery punctuality leads to not only changes in CODP but also to those in the scheduling performance of the LSSC.

  13. Disease progression subtype discovery from longitudinal EMR data with a majority of missing values and unknown initial time points

    PubMed Central

    Huopaniemi, Ilkka; Nadkarni, Girish; Nadukuru, Rajiv; Lotay, Vaneet; Ellis, Steve; Gottesman, Omri; Bottinger, Erwin P

    2014-01-01

    Electronic medical records (EMR) contain a longitudinal collection of laboratory data that contains valuable phenotypic information on disease progression of a large collection of patients. These data can be potentially used in medical research or patient care; finding disease progression subtypes is a particularly important application. There are, however, two significant difficulties in utilizing this data for statistical analysis: (a) a large proportion of data is missing and (b) patients are in very different stages of disease progression and there are no well-defined start points of the time series. We present a Bayesian machine learning model that overcomes these difficulties. The method can use highly incomplete time-series measurement of varying lengths, it aligns together similar trajectories in different phases and is capable of finding consistent disease progression subtypes. We demonstrate the method on finding chronic kidney disease progression subtypes. PMID:25954377

  14. Skilled players' and novices' difficulty anticipating left- vs. right-handed opponents' action intentions varies across different points in time.

    PubMed

    Loffing, Florian; Hagemann, Norbert; Schorer, Jörg; Baker, Joseph

    2015-04-01

    A left-handers' performance advantage in interactive sports is assumed to result from their relative rarity compared to right-handers. Part of this advantage may be explained by athletes facing difficulties anticipating left-handers' action intentions, particularly when anticipation is based on kinematic cues available at an early stage of an opponent's movement. Here we tested whether the type of volleyball attack is predicted better against right- vs. left-handed opponents' movements and whether such handedness effects are evident at earlier time points in skilled players than novices. In a video-based experiment volleyball players and novices predicted the type of shot (i.e., smash vs. lob) of left- and right-handed volleyball attacks occluded at six different time points. Overall, right-handed attacks were better anticipated than left-handed attacks, volleyball players outperformed novices, and performance improved in later occlusion conditions. Moreover, in skilled players the handedness effect was most pronounced when attacks were occluded 480 ms prior to hand-ball-contact, whereas in novices it was most evident 240 ms prior to hand-ball-contact. Our findings provide further evidence of the effect of an opponent's handedness on action outcome anticipation and suggest that its occurrence in the course of an opponent's unfolding action likely depends on an observers' domain-specific skill.

  15. ICESat Laser Altimeter Pointing, Ranging and Timing Calibration from Integrated Residual Analysis: A Summary of Early Mission Results

    NASA Technical Reports Server (NTRS)

    Lutchke, Scott B.; Rowlands, David D.; Harding, David J.; Bufton, Jack L.; Carabajal, Claudia C.; Williams, Teresa A.

    2003-01-01

    On January 12, 2003 the Ice, Cloud and land Elevation Satellite (ICESat) was successfUlly placed into orbit. The ICESat mission carries the Geoscience Laser Altimeter System (GLAS), which consists of three near-infrared lasers that operate at 40 short pulses per second. The instrument has collected precise elevation measurements of the ice sheets, sea ice roughness and thickness, ocean and land surface elevations and surface reflectivity. The accurate geolocation of GLAS's surface returns, the spots from which the laser energy reflects on the Earth's surface, is a critical issue in the scientific application of these data Pointing, ranging, timing and orbit errors must be compensated to accurately geolocate the laser altimeter surface returns. Towards this end, the laser range observations can be fully exploited in an integrated residual analysis to accurately calibrate these geolocation/instrument parameters. Early mission ICESat data have been simultaneously processed as direct altimetry from ocean sweeps along with dynamic crossovers resulting in a preliminary calibration of laser pointing, ranging and timing. The calibration methodology and early mission analysis results are summarized in this paper along with future calibration activities

  16. Free-time and fixed end-point optimal control theory in dissipative media: application to entanglement generation and maintenance.

    PubMed

    Mishima, K; Yamashita, K

    2009-07-07

    We develop monotonically convergent free-time and fixed end-point optimal control theory (OCT) in the density-matrix representation to deal with quantum systems showing dissipation. Our theory is more general and flexible for tailoring optimal laser pulses in order to control quantum dynamics with dissipation than the conventional fixed-time and fixed end-point OCT in that the optimal temporal duration of laser pulses can also be optimized exactly. To show the usefulness of our theory, it is applied to the generation and maintenance of the vibrational entanglement of carbon monoxide adsorbed on the copper (100) surface, CO/Cu(100). We demonstrate the numerical results and clarify how to combat vibrational decoherence as much as possible by the tailored shapes of the optimal laser pulses. It is expected that our theory will be general enough to be applied to a variety of dissipative quantum dynamics systems because the decoherence is one of the quantum phenomena sensitive to the temporal duration of the quantum dynamics.

  17. Location and release time identification of pollution point source in river networks based on the Backward Probability Method.

    PubMed

    Ghane, Alireza; Mazaheri, Mehdi; Mohammad Vali Samani, Jamal

    2016-09-15

    The pollution of rivers due to accidental spills is a major threat to environment and human health. To protect river systems from accidental spills, it is essential to introduce a reliable tool for identification process. Backward Probability Method (BPM) is one of the most recommended tools that is able to introduce information related to the prior location and the release time of the pollution. This method was originally developed and employed in groundwater pollution source identification problems. One of the objectives of this study is to apply this method in identifying the pollution source location and release time in surface waters, mainly in rivers. To accomplish this task, a numerical model is developed based on the adjoint analysis. Then the developed model is verified using analytical solution and some real data. The second objective of this study is to extend the method to pollution source identification in river networks. In this regard, a hypothetical test case is considered. In the later simulations, all of the suspected points are identified, using only one backward simulation. The results demonstrated that all suspected points, determined by the BPM could be a possible pollution source. The proposed approach is accurate and computationally efficient and does not need any simplification in river geometry and flow. Due to this simplicity, it is highly recommended for practical purposes.

  18. Beach response dynamics of a littoral cell using a 17-year single-point time series of sand thickness

    USGS Publications Warehouse

    Barnard, P.L.; Hubbard, D.M.; Dugan, J.E.

    2012-01-01

    A 17-year time series of near-daily sand thickness measurements at a single intertidal location was compared with 5. years of semi-annual 3-dimensional beach surveys at the same beach, and at two other beaches within the same littoral cell. The daily single point measurements correlated extremely well with the mean beach elevation and shoreline position of ten high-spatial resolution beach surveys. Correlations were statistically significant at all spatial scales, even for beach surveys 10s of kilometers downcoast, and therefore variability at the single point monitoring site was representative of regional coastal behavior, allowing us to examine nearly two decades of continuous coastal evolution. The annual cycle of beach oscillations dominated the signal, typical of this region, with additional, less intense spectral peaks associated with seasonal wave energy fluctuations (~. 45 to 90. days), as well as full lunar (~. 29. days) and semi-lunar (~. 13. days; spring-neap cycle) tidal cycles. Sand thickness variability was statistically linked to wave energy with a 2. month peak lag, as well as the average of the previous 7-8. months of wave energy. Longer term anomalies in sand thickness were also apparent on time scales up to 15. months. Our analyses suggest that spatially-limited morphological data sets can be extremely valuable (with robust validation) for understanding the details of beach response to wave energy over timescales that are not resolved by typical survey intervals, as well as the regional behavior of coastal systems. ?? 2011.

  19. Enhancing real-time precise point positioning with zenith troposphere delay products and the determination of corresponding tropospheric stochastic models

    NASA Astrophysics Data System (ADS)

    Yao, Yibin; Peng, Wenjie; Xu, Chaoqian; Cheng, Shuyang

    2017-02-01

    By introducing two types of zenith troposphere delay (ZTD) products in precise point positioning (PPP), we developed the ZTD-corrected PPP and the ZTD-constrained PPP, both of them reduced the PPP convergence time. Both enhanced PPP methods are examined by global empirical ZTD models and regional ZTD corrections. For global ZTD models, we verified that ZTD-corrected PPP will deviate the positioning results, while ZTD-constrained PPP could produce unbiased estimations. Therefore, the latter is utilized to study the performance of global ZTD models (ITG, GPT2w, GZTD and UNB3m). After numerous experiments, we found that the performance of ZTD models was positively related to the real ZTD accuracy, and we proposed a universal tropospheric stochastic model 2SQR(9rms) which denotes double the square of nine times ZTD rms, to constrain ZTD in PPP. The proposed model subsequently was validated by real-time static and kinematic ZTD-constrained PPP on the premise that the ZTD rms on every station was known. Compared with traditional PPP, in static PPP, the number of improved stations is increased by 15.5 per cent (ITG), 14.4 per cent (GPT2w), 11.1 per cent (GZTD) and 8.3 per cent (UNB3m). For kinematic PPP, PPP constrained by ITG model still had the best performance, the number of improved stations is increased by 14.4 per cent, after 30 min of initialization time, 13.4 cm east, 13.4 cm north and 11.7 cm up positioning accuracy was obtained, compared with 15.3 cm east, 15.3 cm north and 14.3 cm up accuracy by traditional PPP. In addition, experiments using regional ZTD corrections to enhance real-time PPP showed that both ZTD-corrected PPP and ZTD-constrained PPP can notably reduce the convergence time on the vertical component (within 15 cm).

  20. A phase 2 safety study of accelerated elotuzumab infusion, over less than 1 hour, in combination with lenalidomide and dexamethasone, in patients with multiple myeloma.

    PubMed

    Berenson, James; Manges, Robert; Badarinath, Suprith; Cartmell, Alan; McIntyre, Kristi; Lyons, Roger; Harb, Wael; Mohamed, Hesham; Nourbakhsh, Ali; Rifkin, Robert

    2017-02-18

    Elotuzumab, an immunostimulatory SLAMF7-targeting monoclonal antibody, induces myeloma cell death with minimal effects on normal tissue. In a previous phase 3 study in patients with relapsed/refractory multiple myeloma (RRMM), elotuzumab (10 mg/kg, ∼3-hour infusion), combined with lenalidomide and dexamethasone, demonstrated durable efficacy and acceptable safety; 10% (33/321) of patients had infusion reactions (IRs; Grade 1/2: 29; Grade 3: 4). This phase 2 study (NCT02159365) investigated an accelerated infusion schedule in 70 patients with newly diagnosed multiple myeloma or RRMM. The primary endpoint was cumulative incidence of Grade 3/4 IRs by completion of treatment Cycle 2. Dosing comprised elotuzumab 10 mg/kg intravenously (weekly, Cycles 1-2; biweekly, Cycles 3+), lenalidomide 25 mg (daily, Days 1-21) and dexamethasone (28 mg orally and 8 mg intravenously, weekly, Cycles 1-2; 40 mg orally, weekly, Cycles 3+), in 28-day cycles. Premedication with diphenhydramine, acetaminophen, and ranitidine (or their equivalents) was given as in previous studies. If no IRs occurred, infusion rate was increased in Cycle 1 from 0.5 to 2 mL/min during dose 1 (∼2 hours 50 min duration) to 5 mL/min for the entire infusion by dose 3 and also during all subsequent infusions (∼1-hour duration). Median number of treatment cycles was six. No Grade 3/4 IRs occurred; only one Grade 1 and one Grade 2 IR occurred, both during the first infusion. These data support the safety of a faster infusion of elotuzumab administered over ∼1 hour by the third dose, providing a more convenient alternative dosing option for patients. This article is protected by copyright. All rights reserved.

  1. Parcellation of the Healthy Neonatal Brain into 107 Regions Using Atlas Propagation through Intermediate Time Points in Childhood.

    PubMed

    Blesa, Manuel; Serag, Ahmed; Wilkinson, Alastair G; Anblagan, Devasuda; Telford, Emma J; Pataky, Rozalia; Sparrow, Sarah A; Macnaught, Gillian; Semple, Scott I; Bastin, Mark E; Boardman, James P

    2016-01-01

    Neuroimage analysis pipelines rely on parcellated atlases generated from healthy individuals to provide anatomic context to structural and diffusion MRI data. Atlases constructed using adult data introduce bias into studies of early brain development. We aimed to create a neonatal brain atlas of healthy subjects that can be applied to multi-modal MRI data. Structural and diffusion 3T MRI scans were acquired soon after birth from 33 typically developing neonates born at term (mean postmenstrual age at birth 39(+5) weeks, range 37(+2)-41(+6)). An adult brain atlas (SRI24/TZO) was propagated to the neonatal data using temporal registration via childhood templates with dense temporal samples (NIH Pediatric Database), with the final atlas (Edinburgh Neonatal Atlas, ENA33) constructed using the Symmetric Group Normalization (SyGN) method. After this step, the computed final transformations were applied to T2-weighted data, and fractional anisotropy, mean diffusivity, and tissue segmentations to provide a multi-modal atlas with 107 anatomical regions; a symmetric version was also created to facilitate studies of laterality. Volumes of each region of interest were measured to provide reference data from normal subjects. Because this atlas is generated from step-wise propagation of adult labels through intermediate time points in childhood, it may serve as a useful starting point for modeling brain growth during development.

  2. Real-Time, Noninvasive Recording And Three-Dimensional Display Of The Functional Movements Of An Arbitrary Mandible Point

    NASA Astrophysics Data System (ADS)

    Mesqui, F.; Kaeser, F.; Fischer, P.

    1986-07-01

    The monitoring of the motion of an arbitrary mandibular point is essential in dentistry in order to extract from typical motion patterns relevant parameters indicating normal or abnormal masticatory function. After first experiences of nonrestrictive jaw motion quantification with the help of a Selspot I we designed a new real-time optoelectronic system. The recording system includes three cameras. Each camera contains a cylindrical lens and a linear optosensor (CCD). Two extra-oral lightweight target frames (2g) containing each three light emitting diodes are fixed on the patients's teeth. The system fires each LED cyclically and computes their three-dimensional coordinates in a reconstruction unit. From these coordinates another processing unit computes the three-dimensional coordinates of an arbitrary jaw point in a head fixed coordinate system. The computed trajectories are drawn on-line with the help of a dedicated 3D viewing hardware on a CRT where they can be directly rotated and zoomed to follow intricate motion details. The system is easy to handle, low-cost, stand-alone, has an excellent linearity and a resolution better than 0.1 mm.

  3. Parcellation of the Healthy Neonatal Brain into 107 Regions Using Atlas Propagation through Intermediate Time Points in Childhood

    PubMed Central

    Blesa, Manuel; Serag, Ahmed; Wilkinson, Alastair G.; Anblagan, Devasuda; Telford, Emma J.; Pataky, Rozalia; Sparrow, Sarah A.; Macnaught, Gillian; Semple, Scott I.; Bastin, Mark E.; Boardman, James P.

    2016-01-01

    Neuroimage analysis pipelines rely on parcellated atlases generated from healthy individuals to provide anatomic context to structural and diffusion MRI data. Atlases constructed using adult data introduce bias into studies of early brain development. We aimed to create a neonatal brain atlas of healthy subjects that can be applied to multi-modal MRI data. Structural and diffusion 3T MRI scans were acquired soon after birth from 33 typically developing neonates born at term (mean postmenstrual age at birth 39+5 weeks, range 37+2–41+6). An adult brain atlas (SRI24/TZO) was propagated to the neonatal data using temporal registration via childhood templates with dense temporal samples (NIH Pediatric Database), with the final atlas (Edinburgh Neonatal Atlas, ENA33) constructed using the Symmetric Group Normalization (SyGN) method. After this step, the computed final transformations were applied to T2-weighted data, and fractional anisotropy, mean diffusivity, and tissue segmentations to provide a multi-modal atlas with 107 anatomical regions; a symmetric version was also created to facilitate studies of laterality. Volumes of each region of interest were measured to provide reference data from normal subjects. Because this atlas is generated from step-wise propagation of adult labels through intermediate time points in childhood, it may serve as a useful starting point for modeling brain growth during development. PMID:27242423

  4. Point-and-stare operation and high-speed image acquisition in real-time hyperspectral imaging

    NASA Astrophysics Data System (ADS)

    Driver, Richard D.; Bannon, David P.; Ciccone, Domenic; Hill, Sam L.

    2010-04-01

    The design and optical performance of a small-footprint, low-power, turnkey, Point-And-Stare hyperspectral analyzer, capable of fully automated field deployment in remote and harsh environments, is described. The unit is packaged for outdoor operation in an IP56 protected air-conditioned enclosure and includes a mechanically ruggedized fully reflective, aberration-corrected hyperspectral VNIR (400-1000 nm) spectrometer with a board-level detector optimized for point and stare operation, an on-board computer capable of full system data-acquisition and control, and a fully functioning internal hyperspectral calibration system for in-situ system spectral calibration and verification. Performance data on the unit under extremes of real-time survey operation and high spatial and high spectral resolution will be discussed. Hyperspectral acquisition including full parameter tracking is achieved by the addition of a fiber-optic based downwelling spectral channel for solar illumination tracking during hyperspectral acquisition and the use of other sensors for spatial and directional tracking to pinpoint view location. The system is mounted on a Pan-And-Tilt device, automatically controlled from the analyzer's on-board computer, making the HyperspecTM particularly adaptable for base security, border protection and remote deployments. A hyperspectral macro library has been developed to control hyperspectral image acquisition, system calibration and scene location control. The software allows the system to be operated in a fully automatic mode or under direct operator control through a GigE interface.

  5. Robust stability analysis and dynamic gain-scheduled controller design for point time-delay systems with parametrical uncertainties

    NASA Astrophysics Data System (ADS)

    De la Sen, M.

    2008-08-01

    This paper discusses linear fractional representations (LFR) of parameter-dependent nonlinear systems with real-rational nonlinearities and point-delayed dynamics. Sufficient conditions for robust global asymptotic stability independent of the delays and the existence of a robust stabilizing gain-scheduled dynamic controller are investigated via linear matrix inequalities. Such inequalities are obtained from the values of the time-derivatives of appropriate Lyapunov functions at all the vertices of the polytope which contains the parametrized uncertainties. The synthesized stabilizing controller consists of an interpolation being performed with the stabilizing controllers at the set of vertices of a certain polytope where the nonlinear-rational parametrization belongs to. Some extensions are also given concerning robust global asymptotic stability dependent of the delays. Numerical examples corroborate the usefulness of the proposed formalism and its applicability to practical related problems.

  6. New time-domain three-point error separation methods for measurement roundness and spindle error motion

    NASA Astrophysics Data System (ADS)

    Liu, Wenwen; Tao, Tingting; Zeng, Hao

    2016-10-01

    Error separation is a key technology for online measuring spindle radial error motion or artifact form error, such as roundness and cylindricity. Three time-domain three-point error separation methods are proposed based on solving the minimum norm solution of the linear equations. Three laser displacement sensors are used to collect a set of discrete measurements recorded, by which a group of linear measurement equations is derived according to the criterion of prior separation form (PSF), prior separation spindle error motion (PSM) or synchronous separation both form and spindle error motion (SSFM). The work discussed the correlations between the angles of three sensors in measuring system, rank of coefficient matrix in the measurement equations and harmonics distortions in the separation results, revealed the regularities of the first order harmonics distortion and recommended the applicable situation of the each method. Theoretical research and large simulations show that SSFM is the more precision method because of the lower distortion.

  7. Initial bioadhesion on dental materials as a function of contact time, pH, surface wettability, and isoelectric point.

    PubMed

    Müller, Christine; Lüders, Anne; Hoth-Hannig, Wiebke; Hannig, Matthias; Ziegler, Christiane

    2010-03-16

    The adsorption of bovine serum albumin (BSA) on surfaces of dental enamel and of dental materials was investigated by scanning force spectroscopy. This method provides adhesion forces which can be measured as a function of contact time between protein and surface, pH, wettability, and isoelectric point of the surface. Whereas the chosen ceramic and composite materials resemble very well the adhesion on natural enamel, a much stronger adhesion was found for the more hydrophobic surfaces, that is, gold, titanium, poly(methyl methacrylate) (PMMA), and poly(tetrafluoroethylene) (PTFE). On hydrophilic surfaces, adhesion is mainly influenced by the electrostatic forces between protein and surface. However, the conformational change of BSA at pH values above pH 8 has to be taken into account. On the very hydrophobic PTFE surface, the special interface structure between PTFE and water plays an important role which governs BSA adhesion.

  8. A space-time point process model for analyzing and predicting case patterns of diarrheal disease in northwestern Ecuador

    PubMed Central

    Ahn, Jaeil; Johnson, Timothy D.; Bhavnani, Darlene; Eisenberg, Joseph N.S.; Mukherjee, Bhramar

    2014-01-01

    We consider modeling case-patterns under a complex spatial and longitudinal sampling design as conducted via a serial case–control study of diarrheal disease in northwestern Ecuador. We build a two-stage space-time model to understand the role of spatially and temporally referenced covariates that reflect social and natural environments in the sampled region, after accounting for unmeasured residual heterogeneities. All diarrheal case events are collected from 21 sampled communities in Esmeraldes province in Ecuador, during seven sampling cycles from 2003 to 2008. The region of interest comprises 158 communities along a river basin. Prediction of case counts at unsampled communities at a future time is of interest along with estimation of risk-related parameters. We propose a computationally feasible two-stage Bayesian approach to estimate the risk-related parameters and conduct predictive inference. We first apply the log Gaussian Cox process (LGCP), commonly used to model spatial clustering of point patterns, to accommodate temporal variation within the sampled communities. Prediction of the number of cases at unsampled communities at a future time is obtained by a disease mapping model conditional on the expected case counts from Stage I. PMID:24889991

  9. Reducing start-up time and minimizing energy losses of Microbial Fuel Cells using Maximum Power Point Tracking strategy

    NASA Astrophysics Data System (ADS)

    Molognoni, Daniele; Puig, Sebastià; Balaguer, M. Dolors; Liberale, Alessandro; Capodaglio, Andrea G.; Callegari, Arianna; Colprim, Jesús

    2014-12-01

    Microbial Fuel Cells (MFCs) are considered to be an environmental friendly energy conversion technology. The main limitations that delay their industrialization include low current and power densities achievable and long start-up times. Maximum Power Point Tracking (MPPT) has been proposed as a method to enhance MFCs electrical performances. However, the specialized literature is still lacking of experimental works on scaled-up reactors and/or real wastewater utilization. This study evaluates the impact of a MPPT system applied to MFCs treating swine wastewater in terms of start-up time and long-term performance. For this purpose, two replicate cells were compared, one with applied MPPT control and one working with fixed resistance. Both MFCs were continuously fed with swine wastewater to validate the control system under real and dynamic conditions. The study demonstrated that the automatic resistance control was able to reduce the start-up time of about one month. Moreover, MPPT system increased of 40% the Coulombic efficiency at steady-state conditions, reduced energy losses associated with anode and cathode reactions and limited methanogenic activity in the anode chamber. A power density of 5.0 ± 0.2 W m-3 NAC was achieved feeding the system at an organic loading rate of 10 kg COD m-3 d-1.

  10. Dual time-point imaging for post-dose binding potential estimation applied to a [(11)C]raclopride PET dose occupancy study.

    PubMed

    Alves, Isadora L; Willemsen, Antoon Tm; Dierckx, Rudi A; da Silva, Ana Maria M; Koole, Michel

    2017-03-01

    Receptor occupancy studies performed with PET often require time-consuming dynamic imaging for baseline and post-dose scans. Shorter protocol approximations based on standard uptake value ratios have been proposed. However, such methods depend on the time-point chosen for the quantification and often lead to overestimation and bias. The aim of this study was to develop a shorter protocol for the quantification of post-dose scans using a dual time-point approximation, which employs kinetic parameters from the baseline scan. Dual time-point was evaluated for a [(11)C]raclopride PET dose occupancy study with the D2 antagonist JNJ-37822681, obtaining estimates for binding potential and receptor occupancy. Results were compared to standard simplified reference tissue model and standard uptake value ratios-based estimates. Linear regression and Bland-Altman analysis demonstrated excellent correlation and agreement between dual time-point and the standard simplified reference tissue model approach. Moreover, the stability of dual time-point-based estimates is shown to be independent of the time-point chosen for quantification. Therefore, a dual time-point imaging protocol can be applied to post-dose [(11)C]raclopride PET scans, resulting in a significant reduction in total acquisition time while maintaining accuracy in the quantification of both the binding potential and the receptor occupancy.

  11. Atmospheric plume progression as a function of time and distance from the release point for radioactive isotopes.

    PubMed

    Eslinger, Paul W; Bowyer, Ted W; Cameron, Ian M; Hayes, James C; Miley, Harry S

    2015-10-01

    The radionuclide network of the International Monitoring System comprises up to 80 stations around the world that have aerosol and xenon monitoring systems designed to detect releases of radioactive materials to the atmosphere from nuclear explosions. A rule of thumb description of plume concentration and duration versus time and distance from the release point is useful when designing and deploying new sample collection systems. This paper uses plume development from atmospheric transport modeling to provide a power-law rule describing atmospheric dilution factors as a function of distance from the release point. Consider the plume center-line concentration seen by a ground-level sampler as a function of time based on a short-duration ground-level release of a nondepositing radioactive tracer. The concentration C (Bq m(-3)) near the ground varies with distance from the source with the relationship C=R×A(D,C) ×e (-λ(-1.552+0.0405×D)) × 5.37×10(-8) × D(-2.35) where R is the release magnitude (Bq), D is the separation distance (km) from the ground level release to the measurement location, λ is the decay constant (h(-1)) for the radionuclide of interest and AD,C is an attenuation factor that depends on the length of the sample collection period. This relationship is based on the median concentration for 10 release locations with different geographic characteristics and 365 days of releases at each location, and it has an R(2) of 0.99 for 32 distances from 100 to 3000 km. In addition, 90 percent of the modeled plumes fall within approximately one order of magnitude of this curve for all distances.

  12. Specific detection of Flt3 point mutations by highly sensitive real-time polymerase chain reaction in acute myeloid leukemia.

    PubMed

    Scholl, Sebastian; Krause, Claudia; Loncarevic, Ivan F; Müller, Rouven; Kunert, Christa; Wedding, Ulrich; Sayer, Herbert G; Clement, Joachim H; Höffken, Klaus

    2005-06-01

    Among activating class III receptor tyrosine kinase (Flt3) mutations, internal tandem duplications of Flt3 (Flt3-ITD) are detected in about 25% of patients with acute myeloid leukemia (AML). In contrast, mutations within the tyrosine kinase domain of Flt3 (Flt3-TKD mutations) are less frequent (approximately 7%), and there are only limited data on the frequency of recently demonstrated activating Flt3 point mutation at codon 592 (Flt3-V592A mutation). We evaluated a new approach for rapid screening of Flt3-TKD and Flt3-V592A mutations using the fluorescence resonance energy transfer (FRET) principle in a group of 122 patients. Based on individual Flt3-TKD mutations, we designed patient-specific primers to perform a highly sensitive polymerase chain reaction (PCR) assay for rapid detection of minimal residual disease (MRD). We also used a model system with MonoMac-6 cells carrying the Flt3-V592A mutation to establish a mutation-specific real-time PCR approach also for this molecular aberration. We identified 9 cases (8%) of Flt3-TKD mutations (5 cases of mutation D835Y, 3 cases of mutation D835H, and 1 case of mutation Del836), and no cases of Flt3-V592A mutation. Screening for Flt3-TKD mutations with fluorescent probes is equivalent to conventional screening using standard PCR followed by EcoRV restriction. We present a real-time PCR protocol that can be used for MRD analyses based on individual Flt3-TKD mutations. Examples of MRD analyses are presented for all 3 subtypes of Flt3-TKD mutation identified in this study. In summary, we demonstrate new methodological approaches for rapid screening of Flt3 point mutations and for detection of MRD based on patient-specific Flt3-TKD mutations.

  13. Reference intervals for coagulation times using two point-of-care analysers in healthy pet rabbits (Oryctolagus cuniculus).

    PubMed

    Mentré, V; Bulliot, C; Linsart, A; Ronot, P

    2014-06-28

    The purpose of this study was to establish reference intervals for prothrombin time (PT) and activated partial prothrombin time (aPTT) in healthy rabbits using two different point-of-care analysers (Idexx Coag DX and MS Quick Vet Coag Combo). These intervals would be useful in the diagnosis of coagulopathies and in the determination of coagulation status in critical patients. We are unaware of reports of coagulation values in pet rabbits. Blood samples were analysed from 81 clinically healthy pet rabbits under three years of age (49 females and 32 males). The reference intervals were as follows (non-parametric method for the MS Quick Vet Coag Combo and Box-Cox Robust method for the Idexx Coag DX, p<0.05 limit for statistical significance): PT (MS Quick Vet Coag Combo)=N=33, 17.2-28.5; PT (Idexx Coag DX)=N=48, 10.0-14.8, aPTT (MS Quick Vet Coag Combo)=N=33, 103.2-159.2 and aPTT (Idexx Coag DX)=N=48, 104.2-159.1. PT was significantly longer using the MS Quick Vet Coag Combo. aPTT was significantly shorter with the MS Quick Vet Coag Combo. On each type of analyser, there was no significant difference between sexes and blood sampling sites. A significant difference was present for the use or not of anaesthesia with the MS Quick Vet Coag Combo analyser. This study on healthy pet rabbits will be useful in point-of-care diagnosis of coagulopathies.

  14. A multiscale maximum entropy moment closure for locally regulated space-time point process models of population dynamics.

    PubMed

    Raghib, Michael; Hill, Nicholas A; Dieckmann, Ulf

    2011-05-01

    The prevalence of structure in biological populations challenges fundamental assumptions at the heart of continuum models of population dynamics based only on mean densities (local or global). Individual-based models (IBMs) were introduced during the last decade in an attempt to overcome this limitation by following explicitly each individual in the population. Although the IBM approach has been quite useful, the capability to follow each individual usually comes at the expense of analytical tract ability, which limits the generality of the statements that can be made. For the specific case of spatial structure in populations of sessile (and identical) organisms, space-time point processes with local regulation seem to cover the middle ground between analytical tract ability and a higher degree of biological realism. This approach has shown that simplified representations of fecundity, local dispersal and density-dependent mortality weighted by the local competitive environment are sufficient to generate spatial patterns that mimic field observations. Continuum approximations of these stochastic processes try to distill their fundamental properties, and they keep track of not only mean densities, but also higher order spatial correlations. However, due to the non-linearities involved they result in infinite hierarchies of moment equations. This leads to the problem of finding a 'moment closure'; that is, an appropriate order of (lower order) truncation, together with a method of expressing the highest order density not explicitly modelled in the truncated hierarchy in terms of the lower order densities. We use the principle of constrained maximum entropy to derive a closure relationship for truncation at second order using normalisation and the product densities of first and second orders as constraints, and apply it to one such hierarchy. The resulting 'maxent' closure is similar to the Kirkwood superposition approximation, or 'power-3' closure, but it is

  15. Adaptive error detection for HDR/PDR brachytherapy: Guidance for decision making during real-time in vivo point dosimetry

    SciTech Connect

    Kertzscher, Gustavo Andersen, Claus E.; Tanderup, Kari

    2014-05-15

    Purpose: This study presents an adaptive error detection algorithm (AEDA) for real-timein vivo point dosimetry during high dose rate (HDR) or pulsed dose rate (PDR) brachytherapy (BT) where the error identification, in contrast to existing approaches, does not depend on an a priori reconstruction of the dosimeter position. Instead, the treatment is judged based on dose rate comparisons between measurements and calculations of the most viable dosimeter position provided by the AEDA in a data driven approach. As a result, the AEDA compensates for false error cases related to systematic effects of the dosimeter position reconstruction. Given its nearly exclusive dependence on stable dosimeter positioning, the AEDA allows for a substantially simplified and time efficient real-time in vivo BT dosimetry implementation. Methods: In the event of a measured potential treatment error, the AEDA proposes the most viable dosimeter position out of alternatives to the original reconstruction by means of a data driven matching procedure between dose rate distributions. If measured dose rates do not differ significantly from the most viable alternative, the initial error indication may be attributed to a mispositioned or misreconstructed dosimeter (false error). However, if the error declaration persists, no viable dosimeter position can be found to explain the error, hence the discrepancy is more likely to originate from a misplaced or misreconstructed source applicator or from erroneously connected source guide tubes (true error). Results: The AEDA applied on twoin vivo dosimetry implementations for pulsed dose rate BT demonstrated that the AEDA correctly described effects responsible for initial error indications. The AEDA was able to correctly identify the major part of all permutations of simulated guide tube swap errors and simulated shifts of individual needles from the original reconstruction. Unidentified errors corresponded to scenarios where the dosimeter position was

  16. Why timing matters in a coastal sea: Trends, variability and tipping points in the Strait of Georgia, Canada

    NASA Astrophysics Data System (ADS)

    Riche, O.; Johannessen, S. C.; Macdonald, R. W.

    2014-03-01

    too short to produce a confident assessment. The timing of geochemical cycles in the Strait of Georgia is delicately poised, with, for example, deep-water oxygen reaching a hypoxic tolerance threshold in the spring, just before deep-water renewal replenishes the oxygen from outside. However, long-term trends in oxygen, temperature and timing of biological activity may lead to the crossing of crucial biological tipping points within this century. Timing is particularly important for monitoring. Relatively long records for basic water properties like temperature and salinity are accompanied by much shorter records for biogeochemical properties like dissolved O2, pH, nutrients and vertical flux, making it difficult to assemble a clear picture of the sorts of changes that may be occurring in the latter. A confident assessment of the ecological resilience of the Strait of Georgia will require longer time series of biological and geochemical properties that are collected with consideration for the strong seasonal variability.

  17. Effect of time-of-flight and point spread function modeling on detectability of myocardial defects in PET

    SciTech Connect

    Schaefferkoetter, Joshua; Ouyang, Jinsong; Rakvongthai, Yothin; El Fakhri, Georges; Nappi, Carmela

    2014-06-15

    Purpose: A study was designed to investigate the impact of time-of-flight (TOF) and point spread function (PSF) modeling on the detectability of myocardial defects. Methods: Clinical FDG-PET data were used to generate populations of defect-present and defect-absent images. Defects were incorporated at three contrast levels, and images were reconstructed by ordered subset expectation maximization (OSEM) iterative methods including ordinary Poisson, alone and with PSF, TOF, and PSF+TOF. Channelized Hotelling observer signal-to-noise ratio (SNR) was the surrogate for human observer performance. Results: For three iterations, 12 subsets, and no postreconstruction smoothing, TOF improved overall defect detection SNR by 8.6% as compared to its non-TOF counterpart for all the defect contrasts. Due to the slow convergence of PSF reconstruction, PSF yielded 4.4% less SNR than non-PSF. For reconstruction parameters (iteration number and postreconstruction smoothing kernel size) optimizing observer SNR, PSF showed larger improvement for faint defects. The combination of TOF and PSF improved mean detection SNR as compared to non-TOF and non-PSF counterparts by 3.0% and 3.2%, respectively. Conclusions: For typical reconstruction protocol used in clinical practice, i.e., less than five iterations, TOF improved defect detectability. In contrast, PSF generally yielded less detectability. For large number of iterations, TOF+PSF yields the best observer performance.

  18. The effects of cuing in time-shared tasks. [for aircraft flight route-way-point information

    NASA Technical Reports Server (NTRS)

    Chechile, R. A.; Sadoski, D. M.

    1983-01-01

    The results of two divided-attention experiments involving the editing of route-way-point displays on an avionics computer unit are reported. Two side tasks were required of the subjects, and either no cue, verbal cues appearing on the CRT, or symbolic cues (lights on the keyboard adjacent to keys to be used) were given to facilitate the primary editing task. Forty female and 30 male undergraduates were trained in the separate and combined tasks and divided randomly into groups of 25 for the cuing tests. A second test with three 10-subject groups was conducted at least one month later to investigate the efficacy of cuing for infrequently used procedures. It is found that only symbolic cuing significantly improved primary-task performance, increasing editing accuracy in the repetitive tests and reducing editing time in the delayed tests. Verbal cuing, probably because it requires additional cognitive effort, has no significant beneficial effect. These results are considered important for designing instruments for work environments requiring the performance of concurrent tasks, and as aircraft cockpits.

  19. The Origin of Sterol Biosynthesis: A Time-Point for the Evolution of Eukaryotes and the Presence of O2

    NASA Astrophysics Data System (ADS)

    Pearson, A.; Budin, M.; Brocks, J. J.

    2003-12-01

    The evolution of sterol biosynthesis is of critical interest to geoscientists as well as to evolutionary biologists. The first enzyme in the pathway, squalene monooxygenase (Sqmo), requires molecular oxygen (O2), suggesting that this process post-dates the evolution of Cyanobacteria. Additionally, the presence of steranes in ancient rocks marks the suggested time-point of eukaryogenesis(1). Sterol biosynthesis is viewed primarily as a eukaryotic process, and the frequency of its occurrence in bacteria long has been a subject of controversy. In this work, 19 protein gene sequences for Sqmo from eukaryotes were compared to all available complete and partial prokaryotic genomes. Twelve protein gene sequences representing oxidosqualene cyclase (Osc), the second enzyme of the sterol biosynthetic pathway, also were examined. The only unequivocal matches among the bacteria were the alpha-proteobacterium, Methylococcus capsulatus, in which sterol biosynthesis already is known, and the planctomycete, Gemmata obscuriglobus. The latter species contains the most abbreviated sterol pathway yet identified in any organism. Experiments show that the major sterols in Gemmata are lanosterol and its uncommon isomer, parkeol. In bacteria, the sterol biosynthesis genes occupy a contiguous coding region and may represent a single operon. Phylogenetic trees show that the sterol pathway in bacteria and eukaryotes has a common ancestry. Gemmata may retain the most ancient remnants of the pathway's origin, and it is likely that sterol biosynthesis in eukaryotes was acquired through gene transfer from bacteria. However, this work indicates that no known prokaryotes could produce the 24-ethyl steranes found in Archaean rocks(1). Therefore these compounds remain indicative of the presence of both eukaryotes and O2 at 2.7 Ga. 1. J. J. Brocks, G. A. Logan, R. Buick, R. E. Summons, (1999) Science 285, 1033-1036.

  20. Relationship of estimated SHIV acquisition time points during the menstrual cycle and thinning of vaginal epithelial layers in pigtail macaques

    PubMed Central

    Kersh, Ellen N.; Ritter, Jana; Butler, Katherine; Ostergaard, Sharon Dietz; Hanson, Debra; Ellis, Shanon; Zaki, Sherif; McNicholl, Janet M.

    2015-01-01

    Background HIV acquisition in the female genital tract remains incompletely understood. Quantitative data on biological HIV risk factors, the influence of reproductive hormones, and infection risk are lacking. We evaluated vaginal epithelial thickness during the menstrual cycle in pigtail macaques (Macaca nemestrina). This model previously revealed increased susceptibility to vaginal infection during and following progesterone-dominated periods in the menstrual cycle. Methods Nucleated and non-nucleated (superficial) epithelial layers were quantitated throughout the menstrual cycle of 16 macaques. We examined the relationship with previously estimated vaginal SHIVSF162P3 acquisition time points in the cycle of 43 different animals repeatedly exposed to low virus doses. Results In the luteal phase (days 17 to cycle end), the mean vaginal epithelium thinned to 66% of mean follicular thickness (days 1-16; p=0.007, Mann-Whitney test). Analyzing four-day segments, the epithelium was thickest on days 9-12, and thinned to 31% thereof on days 29-32, with reductions of nucleated and non-nucleated layers to 36 and 15% of their previous thickness, respectively. The proportion of animals with estimated SHIV acquisition in each cycle segment correlated with non-nucleated layer thinning (Pearson’s r = 0.7, p<0.05, linear regression analysis), but not nucleated layer thinning (Pearson’s r = 0.6, p=0.15). Conclusions These data provide a detailed picture of dynamic cycle-related changes in the vaginal epithelium of pigtail macaques. Substantial thinning occurred in the superficial, non-nucleated layer, which maintains the vaginal microbiome. The findings support vaginal tissue architecture as susceptibility factor for infection and contribute to our understanding of innate resistance to SHIV infection. PMID:26562699

  1. Change Points in the Population Trends of Aerial-Insectivorous Birds in North America: Synchronized in Time across Species and Regions

    PubMed Central

    Smith, Adam C.; Hudson, Marie-Anne R.; Downes, Constance M.; Francis, Charles M.

    2015-01-01

    North American populations of aerial insectivorous birds are in steep decline. Aerial insectivores (AI) are a group of bird species that feed almost exclusively on insects in flight, and include swallows, swifts, nightjars, and flycatchers. The causes of the declines are not well understood. Indeed, it is not clear when the declines began, or whether the declines are shared across all species in the group (e.g., caused by changes in flying insect populations) or specific to each species (e.g., caused by changes in species’ breeding habitat). A recent study suggested that population trends of aerial insectivores changed for the worse in the 1980s. If there was such a change point in trends of the group, understanding its timing and geographic pattern could help identify potential causes of the decline. We used a hierarchical Bayesian, penalized regression spline, change point model to estimate group-level change points in the trends of 22 species of AI, across 153 geographic strata of North America. We found evidence for group-level change points in 85% of the strata. Change points for flycatchers (FC) were distinct from those for swallows, swifts and nightjars (SSN) across North America, except in the Northeast, where all AI shared the same group-level change points. During the 1980s, there was a negative change point across most of North America, in the trends of SSN. For FC, the group-level change points were more geographically variable, and in many regions there were two: a positive change point followed by a negative change point. This group-level synchrony in AI population trends is likely evidence of a response to a common environmental factor(s) with similar effects on many species across broad spatial extents. The timing and geographic patterns of the change points that we identify here should provide a spring-board for research into the causes behind aerial insectivore declines. PMID:26147572

  2. Change Points in the Population Trends of Aerial-Insectivorous Birds in North America: Synchronized in Time across Species and Regions.

    PubMed

    Smith, Adam C; Hudson, Marie-Anne R; Downes, Constance M; Francis, Charles M

    2015-01-01

    North American populations of aerial insectivorous birds are in steep decline. Aerial insectivores (AI) are a group of bird species that feed almost exclusively on insects in flight, and include swallows, swifts, nightjars, and flycatchers. The causes of the declines are not well understood. Indeed, it is not clear when the declines began, or whether the declines are shared across all species in the group (e.g., caused by changes in flying insect populations) or specific to each species (e.g., caused by changes in species' breeding habitat). A recent study suggested that population trends of aerial insectivores changed for the worse in the 1980s. If there was such a change point in trends of the group, understanding its timing and geographic pattern could help identify potential causes of the decline. We used a hierarchical Bayesian, penalized regression spline, change point model to estimate group-level change points in the trends of 22 species of AI, across 153 geographic strata of North America. We found evidence for group-level change points in 85% of the strata. Change points for flycatchers (FC) were distinct from those for swallows, swifts and nightjars (SSN) across North America, except in the Northeast, where all AI shared the same group-level change points. During the 1980s, there was a negative change point across most of North America, in the trends of SSN. For FC, the group-level change points were more geographically variable, and in many regions there were two: a positive change point followed by a negative change point. This group-level synchrony in AI population trends is likely evidence of a response to a common environmental factor(s) with similar effects on many species across broad spatial extents. The timing and geographic patterns of the change points that we identify here should provide a spring-board for research into the causes behind aerial insectivore declines.

  3. A theorem proving the irreversibility of the biological arrow of time, based on fixed points in the brain as a compact, Δ-complete topological space

    NASA Astrophysics Data System (ADS)

    Bounias, Michel

    2000-05-01

    A physical space can exist as a collection of closed topologies in the intersections of abstract topological subspaces provided with non-equal dimensions. Furthermore, the ordered sequence of mappings of one to another intersection provides an arrow of time which is shared by all connected systems of closed, involving those of the brain type with other types (i.e., physical objects of all categories). The topology of closed spaces associates fixed points of the Brouwer's type with fixed points of the Banach's type. The former are specific of each closed and the latter drive the information from the outside space to mental images inside a closed, through mappings of Jordan's points. The set of fixed points thus provides the properties of both perception and self in living organisms. Conditions for existence of various kinds of Banach's type fixed points are fulfilled by the mathematical brain, since it is both a discrete finite structure, thus a compact topological space, and provided with a set distance (Δ), thus Δ-complete. Finally, since (i) iterates in a sequence of mappings include at least a surjective component and (ii) not identical (if even existing) fixed points would be generated by the non-surjective property which would characterize reciprocal mappings, in either metric or nonmetric setting, the reversion of biological time would break the direct link of the self with perception functions. Thus, while time could be reversible for physics, it is perceived as irreversible for biology, although physical and biological objects share a common space.

  4. Estimation of point source fugitive emission rates from a single sensor time series: a conditionally-sampled Gaussian plume reconstruction

    EPA Science Inventory

    This paper presents a technique for determining the trace gas emission rate from a point source. The technique was tested using data from controlled methane release experiments and from measurement downwind of a natural gas production facility in Wyoming. Concentration measuremen...

  5. A comparison of inner ear imaging features at different time points of sudden sensorineural hearing loss with three-dimensional fluid-attenuated inversion recovery magnetic resonance imaging.

    PubMed

    Zhu, Honglei; Ou, Yongkang; Fu, Jia; Zhang, Ya; Xiong, Hao; Xu, Yaodong

    2015-10-01

    It has been reported that about half of patients with sudden sensorineural hearing loss (SSNHL) show high signals in the affected inner ear on three-dimensional, fluid-attenuated inversion recovery magnetic resonance imaging (3D-FLAIR MRI). These signals may reflect minor hemorrhage or an increased concentration of protein in the inner ear, which has passed through blood vessels with increased permeability. Our objective was to compare the positive ratio of the high signal in affected inner ears at different time points to determine the suitable imaging time point for 3D-FLAIR MRI in SSNHL. 3D-FLAIR MRI images were taken at three times, precontrast and approximately 10 min and 4 h after intravenous injection of a single dose of gadodiamide (Gd) (0.1 mmol/kg), in 46 patients with SNHL. We compared the positive findings of the high signals in the inner ear of patients with SNHL as well as the signal intensity ratio (SIR) between the affected cochleae and unaffected cochleae at three time points. The positive ratios of the high signals in the affected inner ear at the time points of precontrast and 10 min and 4 h after the intravenous Gd injection were 26.1, 32.6, and 41.3%, respectively. The high signal intensity ratios of affected inner ears at the three time points were 1.28, 1.31, and 1.48, respectively. The difference between the positive ratios precontrast and at 10 min after the intravenous Gd injection was statistically significant (P = 0.006); the differences between the positive ratios at 4 h after the intravenous Gd injection and precontrast and between the ratios at 4 h and 10 min after the intravenous Gd injection were not statistically significant. The time effects of the median value of SIR were not significant (P = 0.064). We do not recommend 4 h after intravenous Gd injection as a time point to image the inner ear in SNHL. We believe that imaging precontrast and at 10 min after the intravenous Gd injection are suitable time points.

  6. Terrain Dynamics Analysis Using Space-Time Domain Hypersurfaces and Gradient Trajectories Derived From Time Series of 3D Point Clouds

    DTIC Science & Technology

    2015-08-01

    CONTRACT NUMBER Form Approved OMB NO. 0704-0188 3. DATES COVERED (From - To) - UU UU UU UU 01-08-2015 1-Apr-2011 31- Mar -2014 Approved for Public Release...Research Office P.O. Box 12211 Research Triangle Park, NC 27709-2211 landscape dynamics, lidar time series, space time cube, tangible interface...2701 Sullivan Drive Suite 240 Raleigh, NC 27695 -7514 31- Mar -2014 ABSTRACT Terrain Dynamics Analysis Using Space-Time Domain Hypersurfaces and

  7. Space-Time Point Pattern Analysis of Flavescence Dorée Epidemic in a Grapevine Field: Disease Progression and Recovery.

    PubMed

    Maggi, Federico; Bosco, Domenico; Galetto, Luciana; Palmano, Sabrina; Marzachì, Cristina

    2016-01-01

    Analyses of space-time statistical features of a flavescence dorée (FD) epidemic in Vitis vinifera plants are presented. FD spread was surveyed from 2011 to 2015 in a vineyard of 17,500 m(2) surface area in the Piemonte region, Italy; count and position of symptomatic plants were used to test the hypothesis of epidemic Complete Spatial Randomness and isotropicity in the space-time static (year-by-year) point pattern measure. Space-time dynamic (year-to-year) point pattern analyses were applied to newly infected and recovered plants to highlight statistics of FD progression and regression over time. Results highlighted point patterns ranging from disperse (at small scales) to aggregated (at large scales) over the years, suggesting that the FD epidemic is characterized by multiscale properties that may depend on infection incidence, vector population, and flight behavior. Dynamic analyses showed moderate preferential progression and regression along rows. Nearly uniform distributions of direction and negative exponential distributions of distance of newly symptomatic and recovered plants relative to existing symptomatic plants highlighted features of vector mobility similar to Brownian motion. These evidences indicate that space-time epidemics modeling should include environmental setting (e.g., vineyard geometry and topography) to capture anisotropicity as well as statistical features of vector flight behavior, plant recovery and susceptibility, and plant mortality.

  8. Space-Time Point Pattern Analysis of Flavescence Dorée Epidemic in a Grapevine Field: Disease Progression and Recovery

    PubMed Central

    Maggi, Federico; Bosco, Domenico; Galetto, Luciana; Palmano, Sabrina; Marzachì, Cristina

    2017-01-01

    Analyses of space-time statistical features of a flavescence dorée (FD) epidemic in Vitis vinifera plants are presented. FD spread was surveyed from 2011 to 2015 in a vineyard of 17,500 m2 surface area in the Piemonte region, Italy; count and position of symptomatic plants were used to test the hypothesis of epidemic Complete Spatial Randomness and isotropicity in the space-time static (year-by-year) point pattern measure. Space-time dynamic (year-to-year) point pattern analyses were applied to newly infected and recovered plants to highlight statistics of FD progression and regression over time. Results highlighted point patterns ranging from disperse (at small scales) to aggregated (at large scales) over the years, suggesting that the FD epidemic is characterized by multiscale properties that may depend on infection incidence, vector population, and flight behavior. Dynamic analyses showed moderate preferential progression and regression along rows. Nearly uniform distributions of direction and negative exponential distributions of distance of newly symptomatic and recovered plants relative to existing symptomatic plants highlighted features of vector mobility similar to Brownian motion. These evidences indicate that space-time epidemics modeling should include environmental setting (e.g., vineyard geometry and topography) to capture anisotropicity as well as statistical features of vector flight behavior, plant recovery and susceptibility, and plant mortality. PMID:28111581

  9. Points of Transition: Understanding the Constructed Identities of L2 Learners/Users across Time and Space

    ERIC Educational Resources Information Center

    Adawu, Anthony; Martin-Beltran, Melinda

    2012-01-01

    Using sociocultural and poststructuralist theoretical lenses, this study examines the narrative construction of language-learner identity across time and space. We applied cross-narrative methodologies to analyze language-learning autobiographies and interview data from three English users who had recently transitioned to a U.S. context for…

  10. Comparison of Affective Credit Attitude Scores and Credit Use of College Students at Two Points in Time.

    ERIC Educational Resources Information Center

    Hayhoe, Celia Ray

    2002-01-01

    A study of 120 college students' use of credit in 1997 and 1999 showed that, during that time, 60 students graduated; 41 had more credit cards in 1999 than 1997; 62 had fewer; and 32 were repaying student loans. Affective credit attitude scores for those with four or more credit cards and for students who had graduated were lower in 1999 than in…

  11. Coexistence and local μ-stability of multiple equilibrium points for memristive neural networks with nonmonotonic piecewise linear activation functions and unbounded time-varying delays.

    PubMed

    Nie, Xiaobing; Zheng, Wei Xing; Cao, Jinde

    2016-12-01

    In this paper, the coexistence and dynamical behaviors of multiple equilibrium points are discussed for a class of memristive neural networks (MNNs) with unbounded time-varying delays and nonmonotonic piecewise linear activation functions. By means of the fixed point theorem, nonsmooth analysis theory and rigorous mathematical analysis, it is proven that under some conditions, such n-neuron MNNs can have 5(n) equilibrium points located in ℜ(n), and 3(n) of them are locally μ-stable. As a direct application, some criteria are also obtained on the multiple exponential stability, multiple power stability, multiple log-stability and multiple log-log-stability. All these results reveal that the addressed neural networks with activation functions introduced in this paper can generate greater storage capacity than the ones with Mexican-hat-type activation function. Numerical simulations are presented to substantiate the theoretical results.

  12. Point-of-care ultrasonography as a training milestone for internal medicine residents: the time is now

    PubMed Central

    Sabath, Bruce F.; Singh, Gurkeerat

    2016-01-01

    Point-of-care (POC) ultrasonography is considered fundamental in emergency medicine training and recently has become a milestone in critical care fellowship programs as well. Currently, there is no such standard requirement for internal medicine residency programs in the United States. We present a new case and briefly review another case at our institution – a community hospital – in which internal medicine house staff trained in ultrasonography were able to uncover unexpected and critical diagnoses that significantly changed patient care and outcomes. We also review the growing evidence of the application of ultrasound in the diagnosis of a myriad of conditions encountered in general internal medicine as well as the mounting data on the ability of internal medicine residents to apply this technology accurately at the bedside. We advocate that the literature has sufficiently established the role of POC ultrasonography in general internal medicine that there should no longer be any delay in giving this an official place in the development of internal medicine trainees. This may be particularly useful in the community hospital setting where 24-h echocardiography or other sonography may not be readily available. PMID:27802866

  13. Time dependence of the field energy densities surrounding sources: Application to scalar mesons near point sources and to electromagnetic fields near molecules

    NASA Astrophysics Data System (ADS)

    Persico, F.; Power, E. A.

    1987-07-01

    The time dependence of the dressing-undressing process, i.e., the acquiring or losing by a source of a boson field intensity and hence of a field energy density in its neighborhood, is considered by examining some simple soluble models. First, the loss of the virtual field is followed in time when a point source is suddenly decoupled from a neutral scalar meson field. Second, an initially bare point source acquires a virtual meson cloud as the coupling is switched on. The third example is that of an initially bare molecule interacting with the vacuum of the electromagnetic field to acquire a virtual photon cloud. In all three cases the dressing-undressing is shown to take place within an expanding sphere of radius r=ct centered at the source. At each point in space the energy density tends, for large times, to that of the ground state of the total system. Differences in the time dependence of the dressing between the massive scalar field and the massless electromagnetic field are discussed. The results are also briefly discussed in the light of Feinberg's ideas on the nature of half-dressed states in quantum field theory.

  14. Caspase multiplexing: simultaneous homogeneous time-resolved quenching assay (TruPoint) for caspases 1, 3, and 6.

    PubMed

    Karvinen, Jarkko; Elomaa, Annika; Mäkinen, Maija Liisa; Hakala, Harri; Mukkala, Veli Matti; Peuralahti, Jari; Hurskainen, Pertti; Hovinen, Jari; Hemmilä, Ilkka

    2004-02-15

    Caspases are a group of cysteine proteases involved in apoptosis and inflammation. A multiparametric homogeneous assay capable of measuring activity of three different caspases in a single well of a microtiter plate is described. Different fluorescent europium, samarium, terbium, and dysprosium chelates were coupled to a caspase substrate peptide, their luminescence properties, were analyzed, and their function in a time-resolved fluorescence quenching-based caspase 3 assay was studied. Substrates for caspases 1, 2, 3, 6, and 8 and granzyme B were also synthesized and their specificities for different caspases were determined. By selecting suitable lanthanide chelates and substrates we developed a multiparametric homogeneous time-resolved fluorescence quenching-based assay for caspases 1, 3, and 6. The assay was capable of measuring the activity of both single caspases and a mixture of three caspases mixed in the same well.

  15. Turbulent pair separation due to multiscale stagnation point structure and its time asymmetry in two-dimensional turbulence

    NASA Astrophysics Data System (ADS)

    Faber, T.; Vassilicos, J. C.

    2009-01-01

    The pair separation model of Goto and Vassilicos [New J. Phys. 6, 65 (2004)] is revisited and placed on a sound mathematical foundation. A direct numerical simulation of two-dimensional homogeneous isotropic turbulence with an inverse energy cascade and a k-5/3 power law is used to investigate properties of pair separation in two-dimensional turbulence. A special focus lies on the time asymmetry observed between forward and backward separations. Application of the present model to these data suffers from finite inertial range effects and thus, conditional averaging on scales rather than on time has been employed to obtain values for the Richardson constants and their ratio. The Richardson constants for the forward and backward case are found to be (1.066±0.020) and (0.999±0.007), respectively. The ratio of Richardson constants for the backward and forward cases is therefore gb/gf=(0.92±0.03), and hence exhibits a qualitatively different behavior from pair separation in three-dimensional turbulence, where gb>gf [J. Berg et al., Phys. Rev. E 74, 016304 (2006)]. This indicates that previously proposed explanations for this time asymmetry based on the strain tensor eigenvalues are not sufficient to describe this phenomenon in two-dimensional turbulence. We suggest an alternative qualitative explanation based on the time asymmetry related to the inverse versus forward energy cascade. In two-dimensional turbulence, this asymmetry manifests itself in merging eddies due to the inverse cascade, leading to the observed ratio of Richardson constants.

  16. Glycemic Excursions in Type 1 Diabetes in Pregnancy: A Semiparametric Statistical Approach to Identify Sensitive Time Points during Gestation

    PubMed Central

    Gupta, Resmi; Khoury, Jane; Altaye, Mekibib; Dolan, Lawrence

    2017-01-01

    Aim. To examine the gestational glycemic profile and identify specific times during pregnancy that variability in glucose levels, measured by change in velocity and acceleration/deceleration of blood glucose fluctuations, is associated with delivery of a large-for-gestational-age (LGA) baby, in women with type 1 diabetes. Methods. Retrospective analysis of capillary blood glucose levels measured multiple times daily throughout gestation in women with type 1 diabetes was performed using semiparametric mixed models. Results. Velocity and acceleration/deceleration in glucose levels varied across gestation regardless of delivery outcome. Compared to women delivering LGA babies, those delivering babies appropriate for gestational age exhibited significantly smaller rates of change and less variation in glucose levels between 180 days of gestation and birth. Conclusions. Use of innovative statistical methods enabled detection of gestational intervals in which blood glucose fluctuation parameters might influence the likelihood of delivering LGA baby in mothers with type 1 diabetes. Understanding dynamics and being able to visualize gestational changes in blood glucose are a potentially useful tool to assist care providers in determining the optimal timing to initiate continuous glucose monitoring. PMID:28280744

  17. Magnetic field pitch angle and perpendicular velocity measurements from multi-point time-delay estimation of poloidal correlation reflectometry

    NASA Astrophysics Data System (ADS)

    Prisiazhniuk, D.; Krämer-Flecken, A.; Conway, G. D.; Happel, T.; Lebschy, A.; Manz, P.; Nikolaeva, V.; Stroth, U.; the ASDEX Upgrade Team

    2017-02-01

    In fusion machines, turbulent eddies are expected to be aligned with the direction of the magnetic field lines and to propagate in the perpendicular direction. Time delay measurements of density fluctuations can be used to calculate the magnetic field pitch angle α and perpendicular velocity {{v}\\bot} profiles. The method is applied to poloidal correlation reflectometry installed at ASDEX Upgrade and TEXTOR, which measure density fluctuations from poloidally and toroidally separated antennas. Validation of the method is achieved by comparing the perpendicular velocity (composed of the E× B drift and the phase velocity of turbulence {{v}\\bot}={{v}E× B}+{{v}\\text{ph}} ) with Doppler reflectometry measurements and with neoclassical {{v}E× B} calculations. An important condition for the application of the method is the presence of turbulence with a sufficiently long decorrelation time. It is shown that at the shear layer the decorrelation time is reduced, limiting the application of the method. The magnetic field pitch angle measured by this method shows the expected dependence on the magnetic field, plasma current and radial position. The profile of the pitch angle reproduces the expected shape and values. However, comparison with the equilibrium reconstruction code cliste suggests an additional inclination of turbulent eddies at the pedestal position (2-3°). This additional angle decreases towards the core and at the edge.

  18. Real-time adaptive optics testbed to investigate point-ahead angle in pre-compensation of Earth-to-GEO optical communication.

    PubMed

    Leonhard, Nina; Berlich, René; Minardi, Stefano; Barth, Alexander; Mauch, Steffen; Mocci, Jacopo; Goy, Matthias; Appelfelder, Michael; Beckert, Erik; Reinlein, Claudia

    2016-06-13

    We explore adaptive optics (AO) pre-compensation for optical communication between Earth and geostationary (GEO) satellites in a laboratory experiment. Thus, we built a rapid control prototyping breadboard with an adjustable point-ahead angle where downlink and uplink can operate both at 1064 nm and 1550 nm wavelength. With our real-time system, beam wander resulting from artificial turbulence was reduced such that the beam hits the satellite at least 66% of the time as compared to merely 3% without correction. A seven-fold increase of the average Strehl ratio to (28 ± 15)% at 18 μrad point-ahead angle leads to a considerable reduction of the calculated fading probability. These results make AO pre-compensation a viable technique to enhance Earth-to-GEO optical communication.

  19. A Remark on the Heat Equation with a Point Perturbation, the Feynman-Kac Formula with Local Time and Derivative Pricing

    NASA Astrophysics Data System (ADS)

    Albeverio, Sergio; Fassari, Silvestro; Rinaldi, Fabio

    2015-04-01

    We discuss the probabilistic representation of the solutions of the heat equation perturbed by a repulsive point interaction in terms of a perturbation of Brownian motion, via a Feynman-Kac formula involving a local time functional. An application to option pricing is given, interpolating between the extreme cases of classical Black-Scholes options and knockouts having the barrier situated exactly at the exercise price.

  20. Time resolved DNA occupancy dynamics during the respiratory oscillation uncover a global reset point in the yeast growth program

    PubMed Central

    Amariei, Cornelia; Machné, Rainer; Stolc, Viktor; Soga, Tomoyoshi; Tomita, Masaru; Murray, Douglas B.

    2014-01-01

    The structural dynamics of chromatin have been implicated in the regulation of fundamental eukaryotic processes, such as DNA transcription, replication and repair. Although previous studies have revealed that the chromatin landscape, nucleosome remodeling and histone modification events are intimately tied into cellular energetics and redox state, few studies undertake defined time-resolved measurements of these state variables. Here, we use metabolically synchronous, continuously-grown yeast cultures to measure DNA occupancy and track global patterns with respect to the metabolic state of the culture. Combined with transcriptome analyses and ChIP-qPCR experiments, these paint an intriguing picture where genome-wide nucleosome focusing occurs during the recovery of energy charge, followed by clearance of the promoter regions and global transcriptional slow-down, thus indicating a nucleosome-mediated “reset point” for the cycle. The reset begins at the end of the catabolic and stress-response transcriptional programs and ends prior to the start of the anabolic and cell-growth transcriptional program, and the histones on genes from both the catabolic and anabolic superclusters are deacetylated. PMID:28357254

  1. Pb enamel biomarker: Deposition of pre- and postnatal Pb isotope injection in reconstructed time points along rat enamel transect

    SciTech Connect

    Rinderknecht, A.L.; Kleinman, M.T.; Ericson, J.E. . E-mail: jeericso@uci.edu

    2005-10-01

    Exposure to lead (Pb) as well as other heavy metals in the environment is still a matter of public health concern. The development of the enamel biomarker for heavy metal exposure assessment is designed to improve studies of dose-effect relationships to developmental anomalies, particularly embryonic dysfunctions, and to provide a time-specific recount of past exposures. The work presented in this paper demonstrates maternal transfer across the placental barrier of the enriched isotope {sup 206}Pb tracer to the enamel of the rat pup. Likewise, injections of {sup 204}Pb-enriched tracer in the neonate rat resulted in deposition of the tracer in the enamel histology as measured by secondary ion microprobe spectrometry. Through enamel, we were able to observe biological removal and assimilation of prenatal and postnatal tracers, respectively. This research demonstrates that enamel can be used as a biomarker of exposure to Pb and may illustrate the toxicokinetics of incorporating Pb into fetal and neonatal steady-state system processes. The biomarker technique, when completely developed, may be applied to cross-sectional and longitudinal epidemiological research.

  2. Identification of polybrominated diphenyl ether metabolites based on calculated boiling points from COSMO-RS, experimental retention times, and mass spectral fragmentation patterns.

    PubMed

    Simpson, Scott; Gross, Michael S; Olson, James R; Zurek, Eva; Aga, Diana S

    2015-02-17

    The COnductor-like Screening MOdel for Realistic Solvents (COSMO-RS) was used to predict the boiling points of several polybrominated diphenyl ethers (PBDEs) and methylated derivatives (MeO-BDEs) of monohydroxylated BDE (OH-BDE) metabolites. The linear correlation obtained by plotting theoretical boiling points calculated by COSMO-RS against experimentally determined retention times from gas chromatography-mass spectrometry facilitated the identification of PBDEs and OH-BDEs. This paper demonstrates the applicability of COSMO-RS in identifying unknown PBDE metabolites of 2,2',4,4'-tetrabromodiphenyl ether (BDE-47) and 2,2',4,4',6-pentabromodiphenyl ether (BDE-100). Metabolites of BDE-47 and BDE-100 were formed through individual incubations of each PBDE with recombinant cytochrome P450 2B6. Using calculated boiling points and characteristic mass spectral fragmentation patterns of the MeO-BDE positional isomers, the identities of the unknown monohydroxylated metabolites were proposed to be 2'-hydroxy-2,3',4,4'-tetrabromodiphenyl ether (2'-OH-BDE-66) from BDE-47, and 2'-hydroxy-2,3',4,4',6-pentabromodiphenyl ether (2'-OH-BDE-119) and 4-hydroxy-2,2',3,4',6-pentabromodiphenyl ether (4-OH-BDE-91) from BDE-100. The collective use of boiling points predicted with COSMO-RS, and characteristic mass spectral fragmentation patterns provided a valuable tool toward the identification of isobaric compounds.

  3. Application of the nonlinear time series prediction method of genetic algorithm for forecasting surface wind of point station in the South China Sea with scatterometer observations

    NASA Astrophysics Data System (ADS)

    Zhong, Jian; Dong, Gang; Sun, Yimei; Zhang, Zhaoyang; Wu, Yuqin

    2016-11-01

    The present work reports the development of nonlinear time series prediction method of genetic algorithm (GA) with singular spectrum analysis (SSA) for forecasting the surface wind of a point station in the South China Sea (SCS) with scatterometer observations. Before the nonlinear technique GA is used for forecasting the time series of surface wind, the SSA is applied to reduce the noise. The surface wind speed and surface wind components from scatterometer observations at three locations in the SCS have been used to develop and test the technique. The predictions have been compared with persistence forecasts in terms of root mean square error. The predicted surface wind with GA and SSA made up to four days (longer for some point station) in advance have been found to be significantly superior to those made by persistence model. This method can serve as a cost-effective alternate prediction technique for forecasting surface wind of a point station in the SCS basin. Project supported by the National Natural Science Foundation of China (Grant Nos. 41230421 and 41605075) and the National Basic Research Program of China (Grant No. 2013CB430101).

  4. Does point of care prothrombin time measurement reduce the transfusion of fresh frozen plasma in patients undergoing major surgery? The POC-OP randomized-controlled trial

    PubMed Central

    2009-01-01

    Background Bleeding is a frequent complication during surgery. The intraoperative administration of blood products, including packed red blood cells, platelets and fresh frozen plasma (FFP), is often live saving. Complications of blood transfusions contribute considerably to perioperative costs and blood product resources are limited. Consequently, strategies to optimize the decision to transfuse are needed. Bleeding during surgery is a dynamic process and may result in major blood loss and coagulopathy due to dilution and consumption. The indication for transfusion should be based on reliable coagulation studies. While hemoglobin levels and platelet counts are available within 15 minutes, standard coagulation studies require one hour. Therefore, the decision to administer FFP has to be made in the absence of any data. Point of care testing of prothrombin time ensures that one major parameter of coagulation is available in the operation theatre within minutes. It is fast, easy to perform, inexpensive and may enable physicians to rationally determine the need for FFP. Methods/Design The objective of the POC-OP trial is to determine the effectiveness of point of care prothrombin time testing to reduce the administration of FFP. It is a patient and assessor blind, single center randomized controlled parallel group trial in 220 patients aged between 18 and 90 years undergoing major surgery (any type, except cardiac surgery and liver transplantation) with an estimated blood loss during surgery exceeding 20% of the calculated total blood volume or a requirement of FFP according to the judgment of the physicians in charge. Patients are randomized to usual care plus point of care prothrombin time testing or usual care alone without point of care testing. The primary outcome is the relative risk to receive any FFP perioperatively. The inclusion of 110 patients per group will yield more than 80% power to detect a clinically relevant relative risk of 0.60 to receive FFP of

  5. A smart device for label-free and real-time detection of gene point mutations based on the high dark phase contrast of vapor condensation.

    PubMed

    Zhang, Junqi; Fu, Rongxin; Xie, Liping; Li, Qi; Zhou, Wenhan; Wang, Ruliang; Ye, Jiancheng; Wang, Dong; Xue, Ning; Lin, Xue; Lu, Ying; Huang, Guoliang

    2015-10-07

    A smart device for label-free and real-time detection of gene point mutation-related diseases was developed based on the high dark phase contrast of vapor condensation. The main components of the device included a Peltier cooler and a mini PC board for image processing. Heat from the hot side of the Peltier cooler causes the fluid in a copper chamber to evaporate, and the vapor condenses on the surface of a microarray chip placed on the cold side of the cooler. The high dark phase contrast of vapor condensation relative to the analytes on the microarray chip was explored. Combined with rolling circle amplification, the device visualizes less-to-more hydrophilic transitions caused by gene trapping and DNA amplification. A lung cancer gene point mutation was analysed, proving the high selectivity and multiplex analysis capability of this low-cost device.

  6. A Four-Point Screening Method for Assessing Molecular Mechanism of Action (MMOA) Identifies Tideglusib as a Time-Dependent Inhibitor of Trypanosoma brucei GSK3β

    PubMed Central

    Swinney, Zachary T.; Haubrich, Brad A.; Xia, Shuangluo; Ramesha, Chakk; Gomez, Stephen R.; Guyett, Paul; Mensa-Wilmot, Kojo; Swinney, David C.

    2016-01-01

    Background New therapeutics are needed for neglected tropical diseases including Human African trypanosomiasis (HAT), a progressive and fatal disease caused by the protozoan parasites Trypanosoma brucei gambiense and T. b. rhodesiense. There is a need for simple, efficient, cost effective methods to identify new molecules with unique molecular mechanisms of action (MMOAs). The mechanistic features of a binding mode, such as competition with endogenous substrates and time-dependence can affect the observed inhibitory IC50, and differentiate molecules and their therapeutic usefulness. Simple screening methods to determine time-dependence and competition can be used to differentiate compounds with different MMOAs in order to identify new therapeutic opportunities. Methodology/Principal Findings In this work we report a four point screening methodology to evaluate the time-dependence and competition for inhibition of GSK3β protein kinase isolated from T. brucei. Using this method, we identified tideglusib as a time-dependent inhibitor whose mechanism of action is time-dependent, ATP competitive upon initial binding, which transitions to ATP non-competitive with time. The enzyme activity was not recovered following 100-fold dilution of the buffer consistent with an irreversible mechanism of action. This is in contrast to the T. brucei GSK3β inhibitor GW8510, whose inhibition was competitive with ATP, not time-dependent at all measured time points and reversible in dilution experiments. The activity of tideglusib against T. brucei parasites was confirmed by inhibition of parasite proliferation (GI50 of 2.3 μM). Conclusions/Significance Altogether this work demonstrates a straightforward method for determining molecular mechanisms of action and its application for mechanistic differentiation of two potent TbGSK3β inhibitors. The four point MMOA method identified tideglusib as a mechanistically differentiated TbGSK3β inhibitor. Tideglusib was shown to inhibit parasite

  7. Terrestrial laser scanning point clouds time series for the monitoring of slope movements: displacement measurement using image correlation and 3D feature tracking

    NASA Astrophysics Data System (ADS)

    Bornemann, Pierrick; Jean-Philippe, Malet; André, Stumpf; Anne, Puissant; Julien, Travelletti

    2016-04-01

    Dense multi-temporal point clouds acquired with terrestrial laser scanning (TLS) have proved useful for the study of structure and kinematics of slope movements. Most of the existing deformation analysis methods rely on the use of interpolated data. Approaches that use multiscale image correlation provide a precise and robust estimation of the observed movements; however, for non-rigid motion patterns, these methods tend to underestimate all the components of the movement. Further, for rugged surface topography, interpolated data introduce a bias and a loss of information in some local places where the point cloud information is not sufficiently dense. Those limits can be overcome by using deformation analysis exploiting directly the original 3D point clouds assuming some hypotheses on the deformation (e.g. the classic ICP algorithm requires an initial guess by the user of the expected displacement patterns). The objective of this work is therefore to propose a deformation analysis method applied to a series of 20 3D point clouds covering the period October 2007 - October 2015 at the Super-Sauze landslide (South East French Alps). The dense point clouds have been acquired with a terrestrial long-range Optech ILRIS-3D laser scanning device from the same base station. The time series are analyzed using two approaches: 1) a method of correlation of gradient images, and 2) a method of feature tracking in the raw 3D point clouds. The estimated surface displacements are then compared with GNSS surveys on reference targets. Preliminary results tend to show that the image correlation method provides a good estimation of the displacement fields at first order, but shows limitations such as the inability to track some deformation patterns, and the use of a perspective projection that does not maintain original angles and distances in the correlated images. Results obtained with 3D point clouds comparison algorithms (C2C, ICP, M3C2) bring additional information on the

  8. An algorithm for approximating the L * invariant coordinate from the real-time tracing of one magnetic field line between mirror points

    NASA Astrophysics Data System (ADS)

    Lejosne, Solène

    2014-08-01

    The L * invariant coordinate depends on the global electromagnetic field topology at a given instance, and the standard method for its determination requires a computationally expensive drift contour tracing. This fact makes L * a cumbersome parameter to handle. In this paper, we provide new insights on the L * parameter, and we introduce an algorithm for an L * approximation that only requires the real-time tracing of one magnetic field line between mirrors points. This approximation is based on the description of the variation of the magnetic field mirror intensity after an adiabatic dipolarization, i.e., after the nondipolar components of a magnetic field have been turned off with a characteristic time very long in comparison with the particles' drift periods. The corresponding magnetic field topological variations are deduced, assuming that the field line foot points remain rooted in the Earth's surface, and the drift average operator is replaced with a computationally cheaper circular average operator. The algorithm results in a relative difference of a maximum of 12% between the approximate L * and the output obtained using the International Radiation Belt Environment Modeling library, in the case of the Tsyganenko 89 model for the external magnetic field (T89). This margin of error is similar to the margin of error due to small deviations between different magnetic field models at geostationary orbit. This approximate L * algorithm represents therefore a reasonable compromise between computational speed and accuracy of particular interest for real-time space weather forecast purposes.

  9. Study of thermal behavior of vitamin D3 by pyrolysis-GC-MS in combination with boiling point-retention time correlation.

    PubMed

    Sun, Yu'an; Liu, Baoxia; Wang, Guoqing; Zhang, Rongjie; Xie, Bing

    2005-01-01

    The thermal behavior of vitamin D3 was studied based on pyrolysis-GC-MS technique. It was pyrolyzed at 600 degrees C, 750 degrees C, 900 degrees C, respectively. The pyrolysis product were separated With an HP-5 column and identified by the NIST mass spectral search program in combination with the correlation of boiling point and retention time (BP-RT). There are totally 50 components, including mono aromatics and polycyclic aromatic hydrocarbons (PAHs), were determined. It is shown that the contents of the PAHs are increasing with the increasing of the pyrolysis temperature. The contents of the determined components vary from 0.04% to 37.08%.

  10. Simple and Fast Continuous Estimation Method of Respiratory Frequency During Sleep using the Number of Extreme Points of Heart Rate Time Series

    NASA Astrophysics Data System (ADS)

    Yoshida, Yutaka; Yokoyama, Kiyoko; Ishii, Naohiro

    It is reported that frequency component of approximately 0.25Hz of heart rate time series (RSA) is corresponding to the respiratory frequency. In this paper, we proposed that continuous estimation method of respiratory fequency during sleep using the number of extreme points of heart rate time series in real time. Equation for calculation of the method is very simple and the method can continuously calculate frequency by window width of about 18 beats. To evaluate accuracy of proposal method, RSA frequency was calculated using proposal method from the heart rate time series during supine rest. Result, minimum error rate was observed when RSA had time lag for about 11s and error rate was about 13.8%. Result of estimating RSA frequency time series during sleep, it varied regularly during non-REM and varied irregularly during REM. This result is similar as report of previous study about respiratory variability during sleep. Therefore, it is considered that proposal method possible to apply respiratory monitoring system during sleep.

  11. Cr stable isotopes as indicators of Cr(VI) reduction in groundwater: a detailed time-series study of a point-source plume.

    PubMed

    Berna, Emily C; Johnson, Thomas M; Makdisi, Richard S; Basu, Anirban

    2010-02-01

    Chromium stable isotope ratios show promise as indicators of Cr(VI) reduction in groundwater, but no published study has yet demonstrated that expected relationships between (53)Cr/(52)Cr and Cr(VI) concentration, position, and time occur in an actual groundwater plume. We present an extensive data set from a point-source plume in Berkeley, CA; data extend over 5 years and 14 locations covering the entire plume. We interpret the data using a Rayleigh distillation model with an effective fractionation factor that incorporates an intrinsic fractionation factor determined from incubations of site sediments and accounts for reservoir effects in the restricted subsurface zones where Cr(VI) reduction is thought to occur. The groundwater (53)Cr/(52)Cr and Cr(VI) concentration data are consistent with a scenario where the system has reached a steady state: Cr(VI) reduction continues, the extent of reduction at any point is constant over time, reduction proceeds to completion at the downgradient edge of the plume, and the plume is no longer advancing. The overall consistency of the results with a reasonable model for the site supports the use of Cr isotope-based estimates of reduction, but we discuss current uncertainties and limitations of the approach as well.

  12. Effect of Time (Within and Between Days), and Dairy Production Factors on the Impedance Value at 24 Acupuncture Points in Dairy Cows

    PubMed Central

    Bosma, Roel H.; Kalkers-van de Ven, Shirley C.G.; den Boer, Mauk M. J.

    2012-01-01

    Simple Summary: Whether electro-acupuncture can contribute to reduced antibiotic use in dairy farming depends, among other things, on effects of time and production factors on the impedance values (IVs) at acupuncture points (APs). We measured the IV at 24 APs located left (L) and right (R) of the bladder (BL) and stomach (ST) meridians. The effect of time of measurement (assessed on six cows in one herd) was confirmed for seven APs, and of production factors (analyzed using 108 cows in three herds) for seven APs. We recommend BL19R, BL20R and BL46-02L as reference values, and BL14L, BL16L and BL17L for diagnostics, and ten other APs for further study. Abstract: This study evaluated the effect of hour and day of measurement, and of production factors on the impedance values (IVs) at 24 acupuncture points (APs). This is a first step in assessing whether electro-acupuncture can contribute to reduced antibiotic use in dairy farming. The APs studied were left (L) and right (R) points of the bladder (BL) and stomach (ST) meridians. The effect of time was measured in a 3x3 Latin square on six cows in one herd. The effect of production factors was analyzed using 108 cows from three herds for two months. The effect of time excludes BL 14R, 16R, 21R, 22R, 30R, 46-02R, 43-01L and 30L, and ST18 bilaterally for diagnostic use. The contribution of parity, age or lactation period to monthly models of BL21R, 18R and 15R, and ST18R exclude these for diagnostic use. Of the remaining APs, BL19R, BL20R and BL46-02L showed stable IVs and are recommended for reference measurements. APs BL14L, BL16L and BL17L are recommended for diagnostics, and BL 16R, 17R, 18R, 23R, 30R, 15L, 20L, 22L and 29L need further study. Factors contributing to the variation in the IV of several APs were: milk robot, number of inseminations, body condition score, days of the preceding lactation, kg milk and kg milk fat of current and preceding month and preceding year, and milk cell count and urea content

  13. Time-Lapse Analysis of Methane Quantity in the Mary Lee Group of Coal Seams Using Filter-Based Multiple-Point Geostatistical Simulation.

    PubMed

    Karacan, C Özgen; Olea, Ricardo A

    2013-08-01

    Coal seam degasification and its success are important for controlling methane, and thus for the health and safety of coal miners. During the course of degasification, properties of coal seams change. Thus, the changes in coal reservoir conditions and in-place gas content as well as methane emission potential into mines should be evaluated by examining time-dependent changes and the presence of major heterogeneities and geological discontinuities in the field. In this work, time-lapsed reservoir and fluid storage properties of the New Castle coal seam, Mary Lee/Blue Creek seam, and Jagger seam of Black Warrior Basin, Alabama, were determined from gas and water production history matching and production forecasting of vertical degasification wellbores. These properties were combined with isotherm and other important data to compute gas-in-place (GIP) and its change with time at borehole locations. Time-lapsed training images (TIs) of GIP and GIP difference corresponding to each coal and date were generated by using these point-wise data and Voronoi decomposition on the TI grid, which included faults as discontinuities for expansion of Voronoi regions. Filter-based multiple-point geostatistical simulations, which were preferred in this study due to anisotropies and discontinuities in the area, were used to predict time-lapsed GIP distributions within the study area. Performed simulations were used for mapping spatial time-lapsed methane quantities as well as their uncertainties within the study area. The systematic approach presented in this paper is the first time in literature that history matching, TIs of GIPs and filter simulations are used for degasification performance evaluation and for assessing GIP for mining safety. Results from this study showed that using production history matching of coalbed methane wells to determine time-lapsed reservoir data could be used to compute spatial GIP and representative GIP TIs generated through Voronoi decomposition

  14. An Estimation of the Likelihood of Significant Eruptions During 2000-2009 Using Poisson Statistics on Two-Point Moving Averages of the Volcanic Time Series

    NASA Technical Reports Server (NTRS)

    Wilson, Robert M.

    2001-01-01

    Since 1750, the number of cataclysmic volcanic eruptions (volcanic explosivity index (VEI)>=4) per decade spans 2-11, with 96 percent located in the tropics and extra-tropical Northern Hemisphere. A two-point moving average of the volcanic time series has higher values since the 1860's than before, being 8.00 in the 1910's (the highest value) and 6.50 in the 1980's, the highest since the 1910's peak. Because of the usual behavior of the first difference of the two-point moving averages, one infers that its value for the 1990's will measure approximately 6.50 +/- 1, implying that approximately 7 +/- 4 cataclysmic volcanic eruptions should be expected during the present decade (2000-2009). Because cataclysmic volcanic eruptions (especially those having VEI>=5) nearly always have been associated with short-term episodes of global cooling, the occurrence of even one might confuse our ability to assess the effects of global warming. Poisson probability distributions reveal that the probability of one or more events with a VEI>=4 within the next ten years is >99 percent. It is approximately 49 percent for an event with a VEI>=5, and 18 percent for an event with a VEI>=6. Hence, the likelihood that a climatically significant volcanic eruption will occur within the next ten years appears reasonably high.

  15. Portable open-path optical remote sensing (ORS) Fourier transform infrared (FTIR) instrumentation miniaturization and software for point and click real-time analysis

    NASA Astrophysics Data System (ADS)

    Zemek, Peter G.; Plowman, Steven V.

    2010-04-01

    Advances in hardware have miniaturized the emissions spectrometer and associated optics, rendering them easily deployed in the field. Such systems are also suitable for vehicle mounting, and can provide high quality data and concentration information in minutes. Advances in software have accompanied this hardware evolution, enabling the development of portable point-and-click OP-FTIR systems that weigh less than 16 lbs. These systems are ideal for first-responders, military, law enforcement, forensics, and screening applications using optical remote sensing (ORS) methodologies. With canned methods and interchangeable detectors, the new generation of OP-FTIR technology is coupled to the latest forward reference-type model software to provide point-and-click technology. These software models have been established for some time. However, refined user-friendly models that use active, passive, and solar occultation methodologies now allow the user to quickly field-screen and quantify plumes, fence-lines, and combustion incident scenarios in high-temporal-resolution. Synthetic background generation is now redundant as the models use highly accurate instrument line shape (ILS) convolutions and several other parameters, in conjunction with radiative transfer model databases to model a single calibration spectrum to collected sample spectra. Data retrievals are performed directly on single beam spectra using non-linear classical least squares (NLCLS). Typically, the Hitran line database is used to generate the initial calibration spectrum contained within the software.

  16. Self-Organizing Hierarchical Particle Swarm Optimization with Time-Varying Acceleration Coefficients for Economic Dispatch with Valve Point Effects and Multifuel Options

    NASA Astrophysics Data System (ADS)

    Polprasert, Jirawadee; Ongsakul, Weerakorn; Dieu, Vo Ngoc

    2011-06-01

    This paper proposes a self-organizing hierarchical particle swarm optimization (SPSO) with time-varying acceleration coefficients (TVAC) for solving economic dispatch (ED) problem with non-smooth functions including multiple fuel options (MFO) and valve-point loading effects (VPLE). The proposed SPSO with TVAC is the new approach optimizer and good performance for solving ED problems. It can handle the premature convergence of the problem by re-initialization of velocity whenever particles are stagnated in the search space. To properly control both local and global explorations of the swarm during the optimization process, the performance of TVAC is included. The proposed method is tested in different ED problems with non-smooth cost functions and the obtained results are compared to those from many other methods in the literature. The results have revealed that the proposed SPSO with TVAC is effective in finding higher quality solutions for non-smooth ED problems than many other methods.

  17. A procedure for tuning automatic controllers with determining a second-order plant model with time delay from two points of a complex frequency response

    NASA Astrophysics Data System (ADS)

    Kuzishchin, V. F.; Petrov, S. V.

    2012-10-01

    The problem of obtaining the mathematical model of a plant in the course of adaptively tuning the operating automatic closed-loop control systems is considered. A new method is proposed for calculating the parameters of a model with four free coefficients represented by two inertial sections with a time delay. The model parameters are calculated from the data of experiments on determining two points of a plant's complex frequency response. The results from checking the performance of the method in combination with obtaining information on the plant dynamics by applying the Fourier transform to the impulse transient response of the system are presented. The PID controller is tuned using a parameter scanning algorithm with directly checking the amplitude-frequency response of the closed-loop system, using which the stability margin can be calculated and different quality criteria can be applied.

  18. Processing time-series point clouds to reveal strain conditions of the Helheim Glacier terminus and its adjacent mélange

    NASA Astrophysics Data System (ADS)

    Byers, L. C.; Stearns, L. A.; Finnegan, D. C.; LeWinter, A. L.; Gadomski, P. J.; Hamilton, G. S.

    2014-12-01

    Flow near the termini of tidewater glaciers varies over short time-scales due to mechanisms that are poorly understood. Repeat observations with high temporal and spatial resolution, recorded around the terminus, are required to better understand the processes that control flow variability. Progress in light detection and ranging (LiDAR) technology permit such observations of the near-terminus and the pro-glacial ice mélange, though standard workflows for quantifying deformation from point clouds currently do not exist. Here, we test and develop methods for processing displacements from LiDAR data of complexly deforming bodies. We use data collected at 30-minute intervals over three-days in August 2013 at Helheim Glacier, Greenland by a long-range (6-10 km), 1064 nm wavelength Terrestrial LiDAR Scanner (TLS). The total area of coverage was ~25 km2. Distributed shear in glaciers prevents a simple transformation for aligning repeat point clouds, but within small regions (~100 m2) strain is assumed to be minor between scans. Registering a large number of these individual regions, subset from the full point-cloud, results in reduced alignment errors. By subsetting in a regular grid, rasters of velocities between scans are created. However, using data-dependent properties such as point density causes the generation of unevenly spaced velocity estimations, which can locally improve resolution or decrease registration errors. The choice of subsets therefore controls the output product's resolution and accuracy. We test how the spatial segmentation scheme affects the displacement results and alignment errors, finding that displacements can be quantified with limited assumption of the true value of displacement for the subset, barring great morphological changes. By identifying areas that do not deform over the temporal domain of the dataset, and using these as the subsets to align, it should be possible to deduce which structures are accommodating strain. This allows for

  19. The impact of multiple memory formation on dendritic complexity in the hippocampus and anterior cingulate cortex assessed at recent and remote time points

    PubMed Central

    Wartman, Brianne C.; Holahan, Matthew R.

    2014-01-01

    Consolidation processes, involving synaptic and systems level changes, are suggested to stabilize memories once they are formed. At the synaptic level, dendritic structural changes are associated with long-term memory storage. At the systems level, memory storage dynamics between the hippocampus and anterior cingulate cortex (ACC) may be influenced by the number of sequentially encoded memories. The present experiment utilized Golgi-Cox staining and neuron reconstruction to examine recent and remote structural changes in the hippocampus and ACC following training on three different behavioral procedures. Rats were trained on one hippocampal-dependent task only (a water maze task), two hippocampal-dependent tasks (a water maze task followed by a radial arm maze task), or one hippocampal-dependent and one non-hippocampal-dependent task (a water maze task followed by an operant conditioning task). Rats were euthanized recently or remotely. Brains underwent Golgi-Cox processing and neurons were reconstructed using Neurolucida software (MicroBrightField, Williston, VT, USA). Rats trained on two hippocampal-dependent tasks displayed increased dendritic complexity compared to control rats, in neurons examined in both the ACC and hippocampus at recent and remote time points. Importantly, this behavioral group showed consistent, significant structural differences in the ACC compared to the control group at the recent time point. These findings suggest that taxing the demand placed upon the hippocampus, by training rats on two hippocampal-dependent tasks, engages synaptic and systems consolidation processes in the ACC at an accelerated rate for recent and remote storage of spatial memories. PMID:24795581

  20. Lab-in-a-tube: Real-time molecular point-of-care diagnostics for influenza A and B using the cobas® Liat® system.

    PubMed

    Melchers, Willem J G; Kuijpers, Judith; Sickler, Joanna Jackson; Rahamat-Langendoen, Janette

    2017-02-18

    Rapid diagnosis of influenza A and B is important for direct treatment decisions in patient care and for the reduction of in-hospital transmissions. The new real-time PCR based molecular point-of-care (POC) assay, the cobas(®) Influenza A/B test on the cobas(®) Liat(®) System (cobas(®) Liat(®) Influenza A/B assay), generated a PCR result in less than 20 min, was evaluated for the detection of influenza A and B. One hundred twenty-one retrospectively collected respiratory specimens, previously analyzed with a routine influenza A/B test (Diagenode) were tested using the cobas(®) Liat(®) Influenza A/B assay. The cobas(®) Liat(®) Influenza A/B assay allows influenza A and B testing by RT-PCR within 20 min. This assay detected influenza A in 51 of 56 samples positive by the Diagenode test. The five discrepant results were retested with the Cepheid Influenza A/B test, confirming two positive cases. All 30 influenza B Diagenode positive samples were found positive by the cobas(®) Liat(®) Influenza A/B assay. Control samples (viral negative and non-influenza pathogens) were all negative by the cobas(®) Liat(®) Influenza A/B assay. The cobas(®) Liat(®) Influenza A/B assay showed a sensitivity for influenza A/B of 96% and 100%, respectively, and 100% specificity for both targets. The cobas(®) Liat(®) Influenza A/B assay is a useful tool for accurate, rapid, and sensitive detection of influenza A and B, offering timely and personalized patient management and infection control when implemented at the point-of-care.

  1. End-point limiting-dilution real-time PCR assay for evaluation of hepatitis C virus quasispecies in serum: performance under optimal and suboptimal conditions.

    PubMed

    Ramachandran, Sumathi; Xia, Guo-Liang; Ganova-Raeva, Lilia M; Nainan, Omana V; Khudyakov, Yury

    2008-08-01

    An approach for determination of hepatitis C virus (HCV) quasispecies by end-point limiting-dilution real-time PCR (EPLD-PCR) is described. It involves isolation of individual coexisting sequence variants of the hypervariable region 1 (HVR1) of the HCV genome from serum specimens using a limiting-dilution protocol. EPLD-PCR applied to an HCV outbreak study provided insights into the epidemiological relationships between incident and chronic cases. When applied to samples from a longitudinal study of infected patients, HVR1 sequences from each sampling time-point were observed to group as distinct phylogenetic clusters. Melting peak analysis conducted on EPLD-PCR products generated from these patients could be used for evaluation of HVR1 sequence heterogeneity without recourse to clonal sequencing. Further, to better understand the mechanism of single-molecule PCR, experiments were conducted under optimal and suboptimal annealing temperatures. Under all temperature conditions tested, HVR1 variants from the major phylogenetic clusters of quasispecies could be amplified, revealing that successful HVR1 quasispecies analysis is not contingent to dilution of starting cDNA preparations to a single-molecule state. It was found that EPLD-PCR conducted at suboptimal annealing temperatures generated distributions of unique-sequence variants slightly different from the distribution obtained by PCR conducted at the optimal temperature. Hence, EPLD-PCR conditions can be manipulated to access different subpopulations of HCV HVR1 quasispecies, thus, improving the range of the quasispecies detection. Although EPLD-PCR conducted at different conditions detect slightly different quasispecies populations, as was shown in this study, the resulted samples of quasispecies are completely suitable for molecular epidemiological investigation in different clinical and epidemiological settings.

  2. Assessing the Influence of Land Use and Land Cover Datasets with Different Points in Time and Levels of Detail on Watershed Modeling in the North River Watershed, China

    PubMed Central

    Huang, Jinliang; Zhou, Pei; Zhou, Zengrong; Huang, Yaling

    2012-01-01

    Land use and land cover (LULC) information is an important component influencing watershed modeling with regards to hydrology and water quality in the river basin. In this study, the sensitivity of the Soil and Water Assessment Tool (SWAT) model to LULC datasets with three points in time and three levels of detail was assessed in a coastal subtropical watershed located in Southeast China. The results showed good agreement between observed and simulated values for both monthly and daily streamflow and monthly NH4+-N and TP loads. Three LULC datasets in 2002, 2007 and 2010 had relatively little influence on simulated monthly and daily streamflow, whereas they exhibited greater effects on simulated monthly NH4+-N and TP loads. When using the two LULC datasets in 2007 and 2010 compared with that in 2002, the relative differences in predicted monthly NH4+-N and TP loads were −11.0 to −7.8% and −4.8 to −9.0%, respectively. There were no significant differences in simulated monthly and daily streamflow when using the three LULC datasets with ten, five and three categories. When using LULC datasets from ten categories compared to five and three categories, the relative differences in predicted monthly NH4+-N and TP loads were −6.6 to −6.5% and −13.3 to −7.3%, respectively. Overall, the sensitivity of the SWAT model to LULC datasets with different points in time and levels of detail was lower in monthly and daily streamflow simulation than in monthly NH4+-N and TP loads prediction. This research provided helpful insights into the influence of LULC datasets on watershed modeling. PMID:23271303

  3. Real-time estimation of prostate tumor rotation and translation with a kV imaging system based on an iterative closest point algorithm

    NASA Astrophysics Data System (ADS)

    Nasehi Tehrani, Joubin; O'Brien, Ricky T.; Rugaard Poulsen, Per; Keall, Paul

    2013-12-01

    Previous studies have shown that during cancer radiotherapy a small translation or rotation of the tumor can lead to errors in dose delivery. Current best practice in radiotherapy accounts for tumor translations, but is unable to address rotation due to a lack of a reliable real-time estimate. We have developed a method based on the iterative closest point (ICP) algorithm that can compute rotation from kilovoltage x-ray images acquired during radiation treatment delivery. A total of 11 748 kilovoltage (kV) images acquired from ten patients (one fraction for each patient) were used to evaluate our tumor rotation algorithm. For each kV image, the three dimensional coordinates of three fiducial markers inside the prostate were calculated. The three dimensional coordinates were used as input to the ICP algorithm to calculate the real-time tumor rotation and translation around three axes. The results show that the root mean square error was improved for real-time calculation of tumor displacement from a mean of 0.97 mm with the stand alone translation to a mean of 0.16 mm by adding real-time rotation and translation displacement with the ICP algorithm. The standard deviation (SD) of rotation for the ten patients was 2.3°, 0.89° and 0.72° for rotation around the right-left (RL), anterior-posterior (AP) and superior-inferior (SI) directions respectively. The correlation between all six degrees of freedom showed that the highest correlation belonged to the AP and SI translation with a correlation of 0.67. The second highest correlation in our study was between the rotation around RL and rotation around AP, with a correlation of -0.33. Our real-time algorithm for calculation of rotation also confirms previous studies that have shown the maximum SD belongs to AP translation and rotation around RL. ICP is a reliable and fast algorithm for estimating real-time tumor rotation which could create a pathway to investigational clinical treatment studies requiring real-time

  4. Time-lapse analysis of methane quantity in Mary Lee group of coal seams using filter-based multiple-point geostatistical simulation

    USGS Publications Warehouse

    Karacan, C. Özgen; Olea, Ricardo A.

    2013-01-01

    The systematic approach presented in this paper is the first time in literature that history matching, TIs of GIPs and filter simulations are used for degasification performance evaluation and for assessing GIP for mining safety. Results from this study showed that using production history matching of coalbed methane wells to determine time-lapsed reservoir data could be used to compute spatial GIP and representative GIP TIs generated through Voronoi decomposition. Furthermore, performing filter simulations using point-wise data and TIs could be used to predict methane quantity in coal seams subjected to degasification. During the course of the study, it was shown that the material balance of gas produced by wellbores and the GIP reductions in coal seams predicted using filter simulations compared very well, showing the success of filter simulations for continuous variables in this case study. Quantitative results from filter simulations of GIP within the studied area briefly showed that GIP was reduced from an initial ∼73 Bcf (median) to ∼46 Bcf (2011), representing a 37 % decrease and varying spatially through degasification. It is forecasted that there will be an additional ∼2 Bcf reduction in methane quantity between 2011 and 2015. This study and presented results showed that the applied methodology and utilized techniques can be used to map GIP and its change within coal seams after degasification, which can further be used for ventilation design for methane control in coal mines.

  5. The relation between doses or post-plasma time points and apoptosis of leukemia cells induced by dielectric barrier discharge plasma

    NASA Astrophysics Data System (ADS)

    Wang, Chao; Zhang, Haixia; Xue, Zhixiao; Yin, Huijuan; Niu, Qing; Chen, Hongli

    2015-12-01

    The dielectric barrier discharge (DBD) plasma was applied to induce apoptosis of LT-12 leukemia cells. Plasma effects on cell death was evaluated by MTT assay and FCM apoptosis assay with Annexin V/PI double staining, suggesting that plasma killing cells rate and inducing cell apoptosis rate both positively were related to the plasma doses or the post-plasma time points. The cell death rates increased from 15.2% to 33.1% and the apoptosis rate raise from 23.8% to 28% when the dose raise from 60s to 120 s at 8 h post-plasma, while they increased from 15.4% to 34.9% and from 48% to 55.3% respectively at the same doses at 12 h post-plasma. Furthermore, the production of reactive oxygen species (ROS), gene and protein expression for Caspases and Bcl-2 family members were measured for exploring the related apoptotic mechanisms phenomenon. We found ROS immediately increased to 1.24 times of the original amount, then increasing to 5.39-fold at 20 h after treatment. The gene and protein expression for Caspases and Bcl-2 family members are very active at 8-12 h post-plasma. Our results demonstrate that DBD plasma can effectively induce tumor cell death through primarily related apoptotic mechanisms.

  6. Dual time point method for the quantification of irreversible tracer kinetics: A reference tissue approach applied to [(18)F]-FDOPA brain PET.

    PubMed

    Alves, Isadora L; Meles, Sanne K; Willemsen, Antoon Tm; Dierckx, Rudi A; Marques da Silva, Ana M; Leenders, Klaus L; Koole, Michel

    2016-01-01

    The Patlak graphical analysis (PGAREF) for quantification of irreversible tracer binding with a reference tissue model was approximated by a dual time point imaging approach (DTPREF). The DTPREF was applied to 18 [(18)F]-FDOPA brain scans using the occipital cortex as reference region (DTPOCC) and compared to both PGAOCC and striatal-to-occipital ratios (SOR). Pearson correlation analysis and Bland-Altman plots showed an excellent correlation and good agreement between DTPOCC and PGAOCC, while correlations between SOR and PGAOCC were consistently lower. Linear discriminant analysis (LDA) demonstrated a similar performance for all methods in differentiating patients with Parkinson's disease (PD) from healthy controls (HC). Specifically for [(18)F]-FDOPA brain imaging, these findings validate DTPOCC as an approximation for PGAOCC, providing the same quantitative information while reducing the acquisition time to two short static scans. For PD patients, this approach can greatly improve patient comfort while reducing motion artifacts and increasing image quality. In general, DTPREF can improve the clinical applicability of tracers with irreversible binding characteristics when a reference tissue is available.

  7. Time-integrated passive sampling as a complement to conventional point-in-time sampling for investigating drinking-water quality, McKenzie River Basin, Oregon, 2007 and 2010-11

    USGS Publications Warehouse

    McCarthy, Kathleen A.; Alvarez, David A.

    2014-01-01

    The Eugene Water & Electric Board (EWEB) supplies drinking water to approximately 200,000 people in Eugene, Oregon. The sole source of this water is the McKenzie River, which has consistently excellent water quality relative to established drinking-water standards. To ensure that this quality is maintained as land use in the source basin changes and water demands increase, EWEB has developed a proactive management strategy that includes a combination of conventional point-in-time discrete water sampling and time‑integrated passive sampling with a combination of chemical analyses and bioassays to explore water quality and identify where vulnerabilities may lie. In this report, we present the results from six passive‑sampling deployments at six sites in the basin, including the intake and outflow from the EWEB drinking‑water treatment plant (DWTP). This is the first known use of passive samplers to investigate both the source and finished water of a municipal DWTP. Results indicate that low concentrations of several polycyclic aromatic hydrocarbons and organohalogen compounds are consistently present in source waters, and that many of these compounds are also present in finished drinking water. The nature and patterns of compounds detected suggest that land-surface runoff and atmospheric deposition act as ongoing sources of polycyclic aromatic hydrocarbons, some currently used pesticides, and several legacy organochlorine pesticides. Comparison of results from point-in-time and time-integrated sampling indicate that these two methods are complementary and, when used together, provide a clearer understanding of contaminant sources than either method alone.

  8. Magnitude, Timing, and Geometry of Extension in the Southern Sevier Desert Basin From Piercing Points, Seismic-Stratigraphic Reconstruction, and Deep well Data

    NASA Astrophysics Data System (ADS)

    Coogan, J. C.; Decelles, P. G.

    2007-12-01

    Palinspastic reconstruction of Mesozoic thrust sheets provides the main constraint for an estimated 47 km of Cenozoic extensional displacement along the Sevier Desert detachment (SDD) in the central Sevier Desert Basin. Hanging wall and footwall piercing points indicate that the SDD accommodated a minimum of 35 km of extensional displacement in the narrower southern part of the basin. The piercing points for the SDD are defined by the intersection of the SDD, the Canyon Range thrust (CRT), and a regional early Cenozoic erosion surface (ES). The hanging wall piercing point lies immediately northeast of the Cricket Mountains, where the SDD-CRT- ES intersection is narrowly defined by intersecting structure maps derived from published seismic reflection data. The footwall piercing point lies in the southern foothills of the Canyon Range, where the SDD breakaway plane is well constrained by an industry seismic line that lies within 2 km of the exposed intersection of the CRT with the base of the Oligocene Oak City Formation. Timing of extension in the southern Sevier Desert basin is constrained by a kinematic reconstruction of detachment and imbricate fault displacement, footwall uplift, and supradetachment sedimentation for Oligocene, Miocene, and Plio-Pleistocene seismic sequences. The reconstruction is centered on a seismic reflection and gravity interpretation along the published Pan Canadian profiles 2 and 3 that is tied to dated intervals in six industry wells. Fault restoration indicates that Oligocene and Miocene phases of slip each accounted for about 40 percent of the total displacement. Simultaneous backstripping of the Oligocene, Miocene, and Plio-Pleistocene supradetachment sequences records hanging wall subsidence simultaneous with footwall uplift, with a footwall burial history that is consistent with published Miocene apatite and zircon fission-track ages of footwall samples. The geometric evolution of the southern SDD extensional system is consistent

  9. [Determination of the critical time point for efficacy of L-arginine infusion therapy in a case of MELAS with frequent stroke-like episodes].

    PubMed

    Sudo, Akira; Sano, Hitomi; Kawamura, Nobuaki

    2014-01-01

    MELAS (mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes) is the most representative subtype of mitochondrial diseases. Administration of L-arginine (L-Arg) or a precursor of nitric oxide (NO) has been proposed as a promising medication for MELAS because one of the pathophysiological mechanisms is supposedly a decreased capacity for NO-dependent vasodilation. We experienced a girl with MELAS and frequent stroke-like episodes who was treated with L-Arg infusion. We evaluated the efficacy of L-Arg infusion therapy based on whether her headache and nausea were disappeared and neurological symptoms were improved within 24 hours of L-Arg administration. L-Arg infusions were effective in all four episodes when the treatment was started within 4 hours of the onset of stroke-like episodes. On the other hand, the infusion was effective in only one out of five episodes when the medication was delayed by more than 4 hours after the onset. Furthermore, the early administration of L-Arg resulted in better outcomes regarding new lesions determined by brain MRI. Our data suggest that L-Arg infusion may be most effective when it is started within 4 hours of the onset of neurological symptoms in the acute phase of MELAS. The study of a large number of episodes in many patients will be needed to determine the critical time point of L-Arg administration after the onset of the acute phase of MELAS.

  10. Evaluation of the Industrial Point Source Emission Inventory for the Houston Ship Channel Area Using Ship-Based, High-Time-Resolution Measurements of Volatile Organic Compounds

    NASA Astrophysics Data System (ADS)

    Bon, D.; de Gouw, J. A.; Gilman, J. B.; Kuster, W. C.; Lerner, B. M.; Williams, E. J.; Frost, G. J.

    2010-12-01

    Proton Transfer Reaction Ion Trap Mass Spectrometry (PIT-MS) was used to characterize several large (>100 ppbv) industrial volatile organic compound (VOC) plumes in the Houston, Texas Ship Channel observed from the NOAA R/V Ronald H. Brown during the 2006 Texas Air Quality Study (TexAQS) field campaign. Because the ship was sampling close to numerous large emission sources, many of the observed plumes were highly transient making the PIT-MS, with its high time resolution and continuous full mass scan capability, a very useful tool for VOC characterization of the plumes. Plume compositions are compared to the TexAQS2K6 Houston-Galveston-Brazoria Point Source Emission Inventory for individual aromatic compounds; oxygenated VOCs and other selected industrial VOCs observed by PIT-MS. In many cases, we do not find good agreement between the measured plume composition and the VOC speciation in the emissions inventory. These observations are not surprising, as previous research has shown that emission fluxes of individual VOCs may be underestimated by as much as 1-2 orders of magnitude in inventories for the Houston area. In many cases, PIT-MS measurements show clear evidence of industrial emissions not previously identified by the Proton Transfer Reaction (PTR) method. The frequent lack of correlation between large VOC enhancements and enhancements in SO2, NOx and CO suggests large, non-combustion sources of VOCs.

  11. Arrests for child pornography production: data at two time points from a national sample of U.S. law enforcement agencies.

    PubMed

    Wolak, Janis; Finkelhor, David; Mitchell, Kimberly J; Jones, Lisa M

    2011-08-01

    This study collected information on arrests for child pornography (CP) production at two points (2000-2001 and 2006) from a national sample of more than 2,500 law enforcement agencies. In addition to providing descriptive data about an understudied crime, the authors examined whether trends in arrests suggested increasing CP production, shifts in victim populations, and challenges to law enforcement. Arrests for CP production more than doubled from an estimated 402 in 2000-2001 to an estimated 859 in 2006. Findings suggest the increase was related to increased law enforcement activity rather than to growth in the population of CP producers. Adolescent victims increased, but there was no increase in the proportion of arrest cases involving very young victims or violent images. Producers distributed images in 23% of arrest cases, a proportion that did not change over time. This suggests that much CP production may be primarily for private use. Proactive law enforcement operations increased, as did other features consistent with a robust law enforcement response.

  12. Field-induced quantum critical point in planar Heisenberg ferromagnets with long-range interactions: Two-time Green's function framework

    NASA Astrophysics Data System (ADS)

    Campana, L. S.; de Cesare, L.; Esposito, U.; Mercaldo, M. T.; Rabuffo, I.

    2010-07-01

    The two-time Green’s function method is used to study the critical properties and crossover phenomena near the field-induced quantum critical point (QCP) of a d -dimensional spin- S planar Heisenberg ferromagnet with long-range interactions decaying as r-α (with α>d ) with the distance r between spins. We adopt the Callen scheme for spin S and the Tyablikov decoupling procedure which is expected to provide suitable results at low temperatures. Different quantum critical regimes are found in the (α,d) plane and the global structure of the phase diagram is determined showing the typical V-shaped region close to the QCP. Depending on the values of α , we find that also for dimensionalities d⩽2 a finite-temperature critical line, ending in the QCP, exists with asymptotic behaviors and crossovers which can be employed as a useful guide for experimental studies. Moreover, these crossovers are shown to be suitably described in terms of (α,d) -dependent scaling functions and effective critical exponents.

  13. Real-time PCR array chip with capillary-driven sample loading and reactor sealing for point-of-care applications.

    PubMed

    Ramalingam, Naveen; Liu, Hao-Bing; Dai, Chang-Chun; Jiang, Yu; Wang, Hui; Wang, Qinghui; M Hui, Kam; Gong, Hai-Qing

    2009-10-01

    A major challenge for the lab-on-a-chip (LOC) community is to develop point-of-care diagnostic chips that do not use instruments. Such instruments include pumping or liquid handling devices for distribution of patient's nucleic-acid test sample among an array of reactors and microvalves or mechanical parts to seal these reactors. In this paper, we report the development of a primer pair pre-loaded PCR array chip, in which the loading of the PCR mixture into an array of reactors and subsequent sealing of the reactors were realized by a novel capillary-based microfluidics with a manual two-step pipetting operations. The chip is capable of performing simultaneous (parallel) analyses of multiple gene targets and its performance was tested by amplifying twelve different gene targets against cDNA template from human hepatocellular carcinoma using SYBR Green I fluorescent dye. The versatility and reproducibility of the PCR-array chip are demonstrated by real-time PCR amplification of the BNI-1 fragment of SARS cDNA cloned in a plasmid vector. The reactor-to-reactor diffusion of the pre-loaded primer pairs in the chip is investigated to eliminate the possibility of primer cross-contamination. Key technical issues such as PCR mixture loss in gas-permeable PDMS chip layer and bubble generation due to different PDMS-glass bonding methods are investigated.

  14. Time-of-day effects on the internal simulation of motor actions: psychophysical evidence from pointing movements with the dominant and non-dominant arm.

    PubMed

    Gueugneau, Nicolas; Papaxanthis, Charalambos

    2010-05-01

    It is well known that circadian rhythms modulate human physiology and behavior at various levels. However, chronobiological data concerning mental and sensorimotor states of motor actions are still lacking in the literature. In the present study, we examined the effects of time-of-day on two important aspects of the human motor behavior: prediction and laterality. Motor prediction was experimentally investigated by means of imagined movements and laterality by comparing the difference in temporal performance between right and left arm movements. Ten healthy participants had to actually perform or to imagine performing arm-pointing movements between two targets at different hours of the day (i.e., 08:00, 11:00, 14:00, 17:00, 20:00, and 23:00 h). Executed and imagined movements were accomplished with both the right and left arm. We found that both imagined and executed arm pointing movements significantly fluctuated through the day. Furthermore, the accuracy of motor prediction, investigated by the temporal discrepancy between executed and imagined movements, was significantly better in the afternoon (i.e., 14:00, 17:00, and 20:00 h) than morning (08:00 and 11:00 h) and evening (23:00 h). Our results also revealed that laterality was not stable throughout the day. Indeed, the smallest temporal differences between the two arms appeared at 08:00 and 23:00 h, whereas the largest ones occurred at the end of the morning (11:00 h). The daily variation of motor imagery may suggest that internal predictive models are flexible entities that are continuously updated throughout the day. Likewise, the variations in temporal performance between the right and the left arm during the day may indicate a relative independence of the two body sides in terms of circadian rhythms. In general, our findings suggest that cognitive (i.e., mental imagery) and motor (i.e., laterality) states of human behavior are modulated by circadian rhythms.

  15. Determination of n-octanol/water partition coefficient for DDT-related compounds by RP-HPLC with a novel dual-point retention time correction.

    PubMed

    Han, Shu-ying; Qiao, Jun-qin; Zhang, Yun-yang; Yang, Li-li; Lian, Hong-zhen; Ge, Xin; Chen, Hong-yuan

    2011-03-01

    n-Octanol/water partition coefficients (P) for DDTs and dicofol were determined by reversed-phase high performance liquid chromatography (RP-HPLC) on a C(18) column using methanol-water mixture as mobile phase. A dual-point retention time correction (DP-RTC) was proposed to rectify chromatographic retention time (t(R)) shift resulted from stationary phase aging. Based on this correction, the relationship between logP and logk(w), the logarithm of the retention factor extrapolated to pure water, was investigated for a set of 12 benzene homologues and DDT-related compounds with reliable experimental P as model compounds. A linear regression logP=(1.10±0.04) logk(w) - (0.60±0.17) was established with correlation coefficient R(2) of 0.988, cross-validated correlation coefficient R(cv)(2) of 0.983 and standard deviation (SD) of 0.156. This model was further validated using four verification compounds, naphthalene, biphenyl, 2,2-bis(4-chlorophenyl)-1,1-dichloroethane (p,p'-DDD) and 2,2-bis(4-chlorophenyl)-1,1-dichloroethene (p,p'-DDE) with similar structure to DDT. The RP-HPLC-determined P values showed good consistency with shake-flask (SFM) or slow-stirring (SSM) results, especially for highly hydrophobic compounds with logP in the range of 4-7. Then, the P values for five DDT-related compounds, 2-(2-chlorophenyl)-2-(4-chlorophenyl)-1,1,1-trichloroethane (o,p'-DDT), 2-(2-chlorophenyl)-2-(4-chlorophenyl)-1,1-dichloroethane (o,p'-DDD), 2-(2-chlorophenyl)-2-(4-chlorophenyl)-1,1-dichloroethene (o,p'-DDE), and 2,2,2-trichloro-1,1-bis(4-chlorophenyl)ethanol (dicofol) and its main degradation product 4,4'-dichlorobenzophenone (p,p'-DBP) were evaluated by the improved RP-HPLC method for the first time. The excellent precision with SD less than 0.03 proved that the novel DP-RTC protocol can significantly increases the determination accuracy and reliability of P by RP-HPLC.

  16. Differential Diagnosis of Malaria on Truelab Uno®, a Portable, Real-Time, MicroPCR Device for Point-Of-Care Applications

    PubMed Central

    Nair, Chandrasekhar Bhaskaran; Manjula, Jagannath; Subramani, Pradeep Annamalai; Nagendrappa, Prakash B.; Manoj, Mulakkapurath Narayanan; Malpani, Sukriti; Pullela, Phani Kumar; Subbarao, Pillarisetti Venkata; Ramamoorthy, Siva; Ghosh, Susanta K.

    2016-01-01

    Background Sensitive and specific detection of malarial parasites is crucial in controlling the significant malaria burden in the developing world. Also important is being able to identify life threatening Plasmodium falciparum malaria quickly and accurately to reduce malaria related mortality. Existing methods such as microscopy and rapid diagnostic tests (RDTs) have major shortcomings. Here, we describe a new real-time PCR-based diagnostic test device at point-of-care service for resource-limited settings. Methods Truenat® Malaria, a chip-based microPCR test, was developed by bigtec Labs, Bangalore, India, for differential identification of Plasmodium falciparum and Plasmodium vivax parasites. The Truenat Malaria tests runs on bigtec’s Truelab Uno® microPCR device, a handheld, battery operated, and easy-to-use real-time microPCR device. The performance of Truenat® Malaria was evaluated versus the WHO nested PCR protocol. The Truenat® Malaria was further evaluated in a triple-blinded study design using a sample panel of 281 specimens created from the clinical samples characterized by expert microscopy and a rapid diagnostic test kit by the National Institute of Malaria Research (NIMR). A comparative evaluation was done on the Truelab Uno® and a commercial real-time PCR system. Results The limit of detection of the Truenat Malaria assay was found to be <5 parasites/μl for both P. falciparum and P. vivax. The Truenat® Malaria test was found to have sensitivity and specificity of 100% each, compared to the WHO nested PCR protocol based on the evaluation of 100 samples. The sensitivity using expert microscopy as the reference standard was determined to be around 99.3% (95% CI: 95.5–99.9) at the species level. Mixed infections were identified more accurately by Truenat Malaria (32 samples identified as mixed) versus expert microscopy and RDTs which detected 4 and 5 mixed samples, respectively. Conclusion The Truenat® Malaria microPCR test is a valuable

  17. Point-of-care detection and real-time monitoring of intravenously delivered drugs via tubing with an integrated SERS sensor

    NASA Astrophysics Data System (ADS)

    Wu, Hsin-Yu; Cunningham, Brian T.

    2014-04-01

    We demonstrate an approach for detection, identification, and kinetic monitoring of drugs flowing within tubing, through the use of a plasmonic nanodome array (PNA) surface. The PNA structures are fabricated using a low-cost nanoreplica molding process upon a flexible plastic substrate that is subsequently integrated with a flow cell that connects in series with ordinary intravenous (IV) drug delivery tubing. To investigate the potential clinical applications for point-of-care detection and real-time monitoring, we perform SERS detection of ten pharmaceutical compounds (hydrocodone, levorphanol, morphine, oxycodone, methadone, phenobarbital, dopamine, diltiazem, promethazine, and mitoxantrone). We demonstrate dose-dependent SERS signal magnitude, resulting in detection limits (ng ml-1) well below typical administered dosages (mg ml-1). Further, we show that the detected drugs are not permanently attached to the PNA surface, and thus our approach is capable of performing continuous monitoring of drug delivery as materials flow through IV tubing that is connected in series with the sensor. Finally, we demonstrate the potential co-detection of multiple drugs when they are mixed together, and show excellent reproducibility and stability of SERS measurements for periods extending at least five days. The capabilities reported here demonstrate the potential to use PNA SERS surfaces for enhancing the safety of IV drug delivery.We demonstrate an approach for detection, identification, and kinetic monitoring of drugs flowing within tubing, through the use of a plasmonic nanodome array (PNA) surface. The PNA structures are fabricated using a low-cost nanoreplica molding process upon a flexible plastic substrate that is subsequently integrated with a flow cell that connects in series with ordinary intravenous (IV) drug delivery tubing. To investigate the potential clinical applications for point-of-care detection and real-time monitoring, we perform SERS detection of ten

  18. Point-of-Care Autofluorescence Imaging for Real-Time Sampling and Treatment Guidance of Bioburden in Chronic Wounds: First-in-Human Results

    PubMed Central

    DaCosta, Ralph S.; Kulbatski, Iris; Lindvere-Teene, Liis; Starr, Danielle; Blackmore, Kristina; Silver, Jason I.; Opoku, Julie; Wu, Yichao Charlie; Medeiros, Philip J.; Xu, Wei; Xu, Lizhen; Wilson, Brian C.; Rosen, Cheryl; Linden, Ron

    2015-01-01

    Background Traditionally, chronic wound infection is diagnosed by visual inspection under white light and microbiological sampling, which are subjective and suboptimal, respectively, thereby delaying diagnosis and treatment. To address this, we developed a novel handheld, fluorescence imaging device (PRODIGI) that enables non-contact, real-time, high-resolution visualization and differentiation of key pathogenic bacteria through their endogenous autofluorescence, as well as connective tissues in wounds. Methods and Findings This was a two-part Phase I, single center, non-randomized trial of chronic wound patients (male and female, ≥18 years; UHN REB #09-0015-A for part 1; UHN REB #12-5003 for part 2; clinicaltrials.gov Identifier: NCT01378728 for part 1 and NCT01651845 for part 2). Part 1 (28 patients; 54% diabetic foot ulcers, 46% non-diabetic wounds) established the feasibility of autofluorescence imaging to accurately guide wound sampling, validated against blinded, gold standard swab-based microbiology. Part 2 (12 patients; 83.3% diabetic foot ulcers, 16.7% non-diabetic wounds) established the feasibility of autofluorescence imaging to guide wound treatment and quantitatively assess treatment response. We showed that PRODIGI can be used to guide and improve microbiological sampling and debridement of wounds in situ, enabling diagnosis, treatment guidance and response assessment in patients with chronic wounds. PRODIGI is safe, easy to use and integrates into the clinical workflow. Clinically significant bacterial burden can be detected in seconds, quantitatively tracked over days-to-months and their biodistribution mapped within the wound bed, periphery, and other remote areas. Conclusions PRODIGI represents a technological advancement in wound sampling and treatment guidance for clinical wound care at the point-of-care. Trial Registration ClinicalTrials.gov NCT01651845; ClinicalTrials.gov NCT01378728 PMID:25790480

  19. Strain distribution in thin concrete pavement panels under three-point loading to failure with pre-pulse-pump Brillouin optical time domain analysis (Presentation Video)

    NASA Astrophysics Data System (ADS)

    Bao, Yi; Cain, John; Chen, Yizheng; Huang, Ying; Chen, Genda; Palek, Leonard

    2015-04-01

    Thin concrete panels reinforced with alloy polymer macro-synthetic fibers have recently been introduced to rapidly and cost-effectively improve the driving condition of existing roadways by laying down a fabric sheet on the roadways, casting a thin layer of concrete, and then cutting the layer into panels. This study is aimed to understand the strain distribution and potential crack development of concrete panels under three-point loading. To this end, six full-size 6ft×6ft×3in concrete panels were tested to failure in the laboratory. They were instrumented with three types of single-mode optical fiber sensors whose performance and ability to measure the strain distribution and detect cracks were compared. Each optical fiber sensor was spliced and calibrated, and then attached to a fabric sheet using adhesive. A thin layer of mortar (0.25 ~ 0.5 in thick) was cast on the fabric sheet. The three types of distributed sensors were bare SM-28e+ fiber, SM-28e+ fiber with a tight buffer, and concrete crack cable, respectively. The concrete crack cable consisted of one SM-28e+ optical fiber with a tight buffer, one SM-28e+ optical fiber with a loose buffer for temperature compensation, and an outside protective tight sheath. Distributed strains were collected from the three optical fiber sensors with pre-pulse-pump Brillouin optical time domain analysis in room temperature. Among the three sensors, the bare fiber was observed to be most fragile during construction and operation, but most sensitive to strain change or micro-cracks. The concrete crack cable was most rugged, but not as sensitive to micro-cracks and robust in micro-crack measurement as the bare fiber. The ruggedness and sensitivity of the fiber with a tight buffer were in between the bare fiber and the concrete crack cable. The strain distribution resulted from the three optical sensors are in good agreement, and can be applied to successfully locate cracks in the concrete panels. It was observed that the

  20. SOE-LRed: a simple and time-efficient method to localize genes with point mutations onto the Escherichia coli chromosome

    PubMed Central

    Benson, Ryan W.; Cafarelli, Tiziana M.; Godoy, Veronica G.

    2011-01-01

    We report a powerful method to replace wild type genes on the chromosome of Escherichia coli. Employing a unique form of PCR, we generate easily constructible gene fusions bearing single point mutations. Used in conjunction with homologous recombination, this method eliminates cloning procedures previously used for this purpose. PMID:21185880

  1. Unpredictable points and chaos

    NASA Astrophysics Data System (ADS)

    Akhmet, Marat; Fen, Mehmet Onur

    2016-11-01

    It is revealed that a special kind of Poisson stable point, which we call an unpredictable point, gives rise to the existence of chaos in the quasi-minimal set. The existing definitions of chaos are formulated in sets of motions. This is the first time in the literature that description of chaos is initiated from a single motion. The theoretical results are exemplified by means of the symbolic dynamics.

  2. The time-space relationship of the data point (Pixels) of the thematic mapper and multispectral scanner or the myth of simultaneity

    NASA Technical Reports Server (NTRS)

    Gordon, F., Jr.

    1980-01-01

    A simplified explanation of the time space relationships among scanner pixels is presented. The examples of the multispectral scanner (MSS) on Landsats 1, 2, and 3 and the thematic mapper (TM) of Landsat D are used to describe the concept and degree of nonsimultaneity of scanning system data. The time aspects of scanner data acquisition and those parts of the MSS and TM systems related to that phenomena are addressed.

  3. A biospectroscopic analysis of human prostate tissue obtained from different time periods points to a trans-generational alteration in spectral phenotype

    PubMed Central

    Theophilou, Georgios; Lima, Kássio M. G.; Briggs, Matthew; Martin-Hirsch, Pierre L.; Stringfellow, Helen F.; Martin, Francis L.

    2015-01-01

    Prostate cancer is the most commonly-diagnosed malignancy in males worldwide; however, there is marked geographic variation in incidence that may be associated with a Westernised lifestyle. We set out to determine whether attenuated total reflection Fourier-transform infrared (ATR-FTIR) or Raman spectroscopy combined with principal component analysis-linear discriminant analysis or variable selection techniques employing genetic algorithm or successive projection algorithm could be utilised to explore differences between prostate tissues from differing years. In total, 156 prostate tissues from transurethral resection of the prostate procedures for benign prostatic hyperplasia from 1983 to 2013 were collected. These were distributed to form seven categories: 1983–1984 (n = 20), 1988–1989 (n = 25), 1993–1994 (n = 21), 1998–1999 (n = 21), 2003–2004 (n = 21), 2008–2009 (n = 20) and 2012–2013 (n = 21). Ten-μm-thick tissue sections were floated onto Low-E (IR-reflective) slides for ATR-FTIR or Raman spectroscopy. The prostate tissue spectral phenotype altered in a temporal fashion. Examination of the two categories that are at least one generation (30 years) apart indicated highly-significant segregation, especially in spectral regions containing DNA and RNA bands (≈1,000–1,490 cm−1). This may point towards alterations that have occurred through genotoxicity or through epigenetic modifications. Immunohistochemical studies for global DNA methylation supported this. This study points to a trans-generational phenotypic change in human prostate. PMID:26310632

  4. A biospectroscopic analysis of human prostate tissue obtained from different time periods points to a trans-generational alteration in spectral phenotype.

    PubMed

    Theophilou, Georgios; Lima, Kássio M G; Briggs, Matthew; Martin-Hirsch, Pierre L; Stringfellow, Helen F; Martin, Francis L

    2015-08-27

    Prostate cancer is the most commonly-diagnosed malignancy in males worldwide; however, there is marked geographic variation in incidence that may be associated with a Westernised lifestyle. We set out to determine whether attenuated total reflection Fourier-transform infrared (ATR-FTIR) or Raman spectroscopy combined with principal component analysis-linear discriminant analysis or variable selection techniques employing genetic algorithm or successive projection algorithm could be utilised to explore differences between prostate tissues from differing years. In total, 156 prostate tissues from transurethral resection of the prostate procedures for benign prostatic hyperplasia from 1983 to 2013 were collected. These were distributed to form seven categories: 1983-1984 (n = 20), 1988-1989 (n = 25), 1993-1994 (n = 21), 1998-1999 (n = 21), 2003-2004 (n = 21), 2008-2009 (n = 20) and 2012-2013 (n = 21). Ten-μm-thick tissue sections were floated onto Low-E (IR-reflective) slides for ATR-FTIR or Raman spectroscopy. The prostate tissue spectral phenotype altered in a temporal fashion. Examination of the two categories that are at least one generation (30 years) apart indicated highly-significant segregation, especially in spectral regions containing DNA and RNA bands (≈1,000-1,490 cm(-1)). This may point towards alterations that have occurred through genotoxicity or through epigenetic modifications. Immunohistochemical studies for global DNA methylation supported this. This study points to a trans-generational phenotypic change in human prostate.

  5. From the wrong point of view! Athletes' ability to identify structured playing patterns suffers from the misalignment of tactic boards during time-outs in professional basketball.

    PubMed

    Schul, Karsten; Memmert, Daniel; Weigelt, Matthias; Jansen, Petra

    2014-01-01

    In professional basketball, coaches commonly use time-outs to instruct players on the upcoming playing pattern. In an explorative study a total of 154 time-outs in professional basketball were analyzed and the data revealed that coaches usually present these playing patterns from their own viewing perspective on the tactic board. This habit leads to a misalignment of the instructed playing pattern with the viewing perspective of players, so that they have to mentally rotate the pattern's spatial-temporal information before they can execute the action on the court. In an experimental study thirty-two basketball experts and forty-eight novices watched video clips of different playing patterns, which were presented from their own or from a coaches' viewing perspective. Identification performance suffered significantly for experts and novices when the upcoming pattern was presented upside down. It is suggested that basketball coaches should align their tactic boards with the viewing perspective of their athletes during time-outs.

  6. Fat accumulation, fatty acids and melting point changes in broiler chick abdominal fat as affected by time of dietary fat feeding and slaughter age.

    PubMed

    Carmona, J M; Lopez-Bote, C J; Daza, A; Rey, A I

    2017-03-23

    1. This work aims to quantify changes in fatty acid profile, melting point, abdominal fat accumulation and 2-thiobarbituric acid-reactive substances production depending on dietary fat source and age at slaughter, and to estimate the optimal date for the change from an unsaturated fat to a saturated fat diet or vice versa. 2. Treatments established were (1) birds fed 8% tallow from 21 to 49 d (TTT); (2) birds fed 8% tallow from 21 to 37 d and 8% sunflower oil from d 38 to 49 (TSS); (3) birds fed 8% sunflower oil from 21 to 37 d and 8% tallow from d 38 to 49 (STT); (4) birds fed 8% sunflower oil from 21 to 41 d and 8% tallow from d 42 to 49 (SST); (5) birds fed 8% sunflower oil from 21 to 49 d (SSS). Birds from each group were slaughtered on d 21, 29, 38, 40, 42, 44, 46 and 49. 3. The polyunsaturated fatty acids (PUFAs) proportion in the SSS group reached maximum values at d 40 and fitted a quadratic response. This group also showed a decrease in saturated fatty acids (SATs) and monounsaturated fatty acids (MUFAs) of lower intensity than the PUFA increase. The highest synthesis of SAT + MUFA was found in the SSS and TSS groups, whereas these had the lowest body-to-dietary PUFA ratio. 4. A high and quadratic increase in the MUFA proportion was observed during the first 10 d of feeding with the tallow-enriched diet at the expenses of the proportion of PUFA that quadratically decreased (minimum values at d 38). 5. Lipogenic and desaturation capacity decreased with age. 6. The TSS group increased tissue PUFA content faster that the SST group decreased PUFA content after the change in diet which indicates that the earlier feeding has to be taken into consideration for obtaining higher or lower changes in quality parameters. 7. The melting point of the SSS group showed a lower response to the dietary treatment in the initial period when compared to the TTT treatment. 8. The TTT, STT, SST and TSS groups showed similar fat accumulation, and changes in lipid

  7. Label-free microfluidic free-flow isoelectric focusing, pH gradient sensing and near real-time isoelectric point determination of biomolecules and blood plasma fractions.

    PubMed

    Poehler, Elisabeth; Herzog, Christin; Lotter, Carsten; Pfeiffer, Simon A; Aigner, Daniel; Mayr, Torsten; Nagl, Stefan

    2015-11-21

    We demonstrate the fabrication, characterization and application of microfluidic chips capable of continuous electrophoretic separation via free flow isoelectric focussing (FFIEF). By integration of a near-infrared (NIR) fluorescent pH sensor layer under the whole separation bed, on-line observation of the pH gradient and determination of biomolecular isoelectric points (pI) was achieved within a few seconds. Using an optical setup for imaging of the intrinsic fluorescence of biomolecules at 266 nm excitation, labelling steps could be avoided and the native biomolecules could be separated, collected and analysed for their pI. The fabricated microchip was successfully used for the monitoring of the separation and simultaneous observation of the pH gradient during the isoelectric focussing of the proteins α-lactalbumin and β-lactoglobulin, blood plasma proteins and the antibiotics ampicillin and ofloxacin. The obtained pIs are in good agreement with literature data, demonstrating the applicability of the system. Mass spectra from the separated antibiotics taken after 15 minutes of continuous separation from different fractions at the end of the microchip validated the separation via microfluidic isoelectric focussing and indicate the possibility of further on- or off-chip processing steps.

  8. Getting It Right the First Time: Defining Regionally Relevant Training Curricula and Provider Core Competencies for Point-of-Care Ultrasound Education on the African Continent.

    PubMed

    Salmon, Margaret; Landes, Megan; Hunchak, Cheryl; Paluku, Justin; Malemo Kalisya, Luc; Salmon, Christian; Muller, Mundenga Mutendi; Wachira, Benjamin; Mangan, James; Chhaganlal, Kajal; Kalanzi, Joseph; Azazh, Aklilu; Berman, Sara; Zied, El-Sayed; Lamprecht, Hein

    2017-02-01

    Significant evidence identifies point-of-care ultrasound (PoCUS) as an important diagnostic and therapeutic tool in resource-limited settings. Despite this evidence, local health care providers on the African continent continue to have limited access to and use of ultrasound, even in potentially high-impact fields such as obstetrics and trauma. Dedicated postgraduate emergency medicine residency training programs now exist in 8 countries, yet no current consensus exists in regard to core PoCUS competencies. The current practice of transferring resource-rich PoCUS curricula and delivery methods to resource-limited health systems fails to acknowledge the unique challenges, needs, and disease burdens of recipient systems. As emergency medicine leaders from 8 African countries, we introduce a practical algorithmic approach, based on the local epidemiology and resource constraints, to curriculum development and implementation. We describe an organizational structure composed of nexus learning centers for PoCUS learners and champions on the continent to keep credentialing rigorous and standardized. Finally, we put forth 5 key strategic considerations: to link training programs to hospital systems, to prioritize longitudinal learning models, to share resources to promote health equity, to maximize access, and to develop a regional consensus on training standards and credentialing.

  9. The evolution of ROAN 2016 - Radio surveillance of meteors and determination of reflection points through calculation of the radio path, based on times

    NASA Astrophysics Data System (ADS)

    Georgescu, T.; Georgescu, A.; Lesanu, C.

    2016-01-01

    The article presents the activity calendar describing the steps until the finalization of the Allsky project in December 2016. It presents also the new developed technology for detection and localization of meteors' ionic traces, which is based on information time-stamped on the radio carrier. The year 2016 is the final one for our project, during which our target is the creation of 25 integrated stations (radio and video, Allsky MK3 type) and to install the ROAN radio beacon. Its location will be the operation base initially, before being moved to an eastern spot, near the Ukrainian border. The novelty of it all is brought by the newly patented technology of time-stamping.

  10. Design of a nanoscale time-of-flight sensor and an integrated multiscale module for the point-of-care diagnosis of stroke

    NASA Astrophysics Data System (ADS)

    Andrus, Matthew

    Stroke is a leading cause of death and disability in the United States, however, there remains no rapid diagnostic test for differentiating between ischemic and hemorrhagic stroke within the three-hour treatment window. Here we describe the design of a multiscale microfluidic module with an embedded time-of-flight nanosensor for the clinical diagnosis of stroke. The nanosensor described utilizes two synthetic pores in series, relying on resistive pulse sensing (RPS) to measure the passage of molecules through the time-of-flight tube. Once the nanosensor design was completed, a multiscale module to process patient samples and house the sensors was designed in a similar iterative process. This design utilized pillar arrays, called "pixels" to immobilize oligonucleotides from patient samples for ligase detection reactions (LDR) to be carried out. COMSOL simulations were performed to understand the operation and behavior of both the nanosensor and the modular chip once the designs were completed.

  11. Quantitative measurement of blood flow in paediatric brain tumours—a comparative study of dynamic susceptibility contrast and multi time-point arterial spin labelled MRI

    PubMed Central

    Abernethy, Laurence; Pizer, Barry; Avula, Shivaram; Parkes, Laura M

    2016-01-01

    Objective: Arterial spin-labelling (ASL) MRI uses intrinsic blood water to quantify the cerebral blood flow (CBF), removing the need for the injection of a gadolinium-based contrast agent used for conventional perfusion imaging such as dynamic susceptibility contrast (DSC). Owing to the non-invasive nature of the technique, ASL is an attractive option for use in paediatric patients. This work compared DSC and multi-timepoint ASL measures of CBF in paediatric brain tumours. Methods: Patients (n = 23; 20 low-grade tumours and 3 high-grade tumours) had DSC and multi-timepoint ASL with and without vascular crushers (VC). VC removes the contribution from larger vessel blood flow. Mean perfusion metrics were extracted from control and T1-enhanced tumour regions of interest (ROIs): arterial arrival time (AAT) and CBF from the ASL images with and without VC, relative cerebral blood flow (rCBF), relative cerebral blood volume, delay time (DT) and mean transit time (MTT) from the DSC images. Results: Significant correlations existed for: AAT and DT (r = 0.77, p = 0.0002) and CBF and rCBF (r = 0.56, p = 0.02) in control ROIs for ASL-noVC. No significant correlations existed between DSC and ASL measures in the tumour region. Significant differences between control and tumour ROI were found for MTT (p < 0.001) and rCBF (p < 0.005) measures. Conclusion: Significant correlations between ASL-noVC and DSC measures in the normal brain suggest that DSC is most sensitive to macrovascular blood flow. The absence of significant correlations within the tumour ROI suggests that ASL is sensitive to different physiological mechanisms compared with DSC measures. Advances in knowledge: ASL provides information which is comparable with that of DSC in healthy tissues, but appears to reflect a different physiology in tumour tissues. PMID:26975495

  12. History of Maltreatment in Childhood and Subsequent Parenting Stress in At-Risk, First-Time Mothers: Identifying Points of Intervention During Home Visiting.

    PubMed

    Shenk, Chad E; Ammerman, Robert T; Teeters, Angelique R; Bensman, Heather E; Allen, Elizabeth K; Putnam, Frank W; Van Ginkel, Judith B

    2017-04-01

    Home visiting is an effective preventive intervention that can improve parenting outcomes for at-risk, new mothers, thereby optimizing subsequent child development. A history of maltreatment in childhood is common in mothers participating in home visiting, yet the extent to which such a history is related to parenting outcomes during home visiting is unknown. The current study evaluated whether mothers with a history of maltreatment in childhood respond less favorably to home visiting by examining the direct and indirect pathways to subsequent parenting stress, a key parenting outcome affecting child development. First-time mothers (N = 220; age range = 16-42) participating in one of two home visiting programs, Healthy Families America or Nurse Family Partnership, were evaluated at enrollment and again at 9-and 18-month post-enrollment assessments. Researchers administered measures of maternal history of maltreatment in childhood, depressive symptoms, social support, and parenting stress. Maternal history of maltreatment in childhood predicted worsening parenting stress at the 18-month assessment. Mediation modeling identified two indirect pathways, one involving social support at enrollment and one involving persistent depressive symptoms during home visiting, that explained the relation between a history of maltreatment in childhood and parenting stress at the 18-month assessment. Ways to improve the preventive effects of home visiting for mothers with a history of maltreatment in childhood through the identification of relevant intervention targets and their ideal time of administration are discussed.

  13. Reported barriers to mental health care in three samples of U.S. Army National Guard soldiers at three time points.

    PubMed

    Valenstein, Marcia; Gorman, Lisa; Blow, Adrian J; Ganoczy, Dara; Walters, Heather; Kees, Michelle; Pfeiffer, Paul N; Kim, H Myra; Lagrou, Robert; Wadsworth, Shelley MacDermid; Rauch, Sheila A M; Dalack, Gregory W

    2014-08-01

    The military community and its partners have made vigorous efforts to address treatment barriers and increase appropriate mental health services use among returning National Guard soldiers. We assessed whether there were differences in reports of treatment barriers in 3 categories (stigma, logistics, or negative beliefs about treatment) in sequential cross-sectional samples of U.S. soldiers from a Midwestern Army National Guard Organization who were returning from overseas deployments. Data were collected during 3 time periods: September 2007-August 2008 (n = 333), March 2009-March 2010 (n = 884), and August 2011-August 2012 (n = 737). In analyses using discretized time periods and in trend analyses, the percentages of soldiers endorsing negative beliefs about treatment declined significantly across the 3 sequential samples (19.1%, 13.9%, and 11.1%). The percentages endorsing stigma barriers (37.8%, 35.2%, 31.8%) decreased significantly only in trend analyses. Within the stigma category, endorsement of individual barriers regarding negative reactions to a soldier seeking treatment declined, but barriers related to concerns about career advancement did not. Negative treatment beliefs were associated with reduced services use (OR = 0.57; 95% CI [0.33, 0.97]).

  14. Methods of a large prospective, randomised, open-label, blinded end-point study comparing morning versus evening dosing in hypertensive patients: the Treatment In Morning versus Evening (TIME) study

    PubMed Central

    Rorie, David A; Rogers, Amy; Mackenzie, Isla S; Ford, Ian; Webb, David J; Willams, Bryan; Brown, Morris; Poulter, Neil; Findlay, Evelyn; Saywood, Wendy; MacDonald, Thomas M

    2016-01-01

    Introduction Nocturnal blood pressure (BP) appears to be a better predictor of cardiovascular outcome than daytime BP. The BP lowering effects of most antihypertensive therapies are often greater in the first 12 h compared to the next 12 h. The Treatment In Morning versus Evening (TIME) study aims to establish whether evening dosing is more cardioprotective than morning dosing. Methods and analysis The TIME study uses the prospective, randomised, open-label, blinded end-point (PROBE) design. TIME recruits participants by advertising in the community, from primary and secondary care, and from databases of consented patients in the UK. Participants must be aged over 18 years, prescribed at least one antihypertensive drug taken once a day, and have a valid email address. After the participants have self-enrolled and consented on the secure TIME website (http://www.timestudy.co.uk) they are randomised to take their antihypertensive medication in the morning or the evening. Participant follow-ups are conducted after 1 month and then every 3 months by automated email. The trial is expected to run for 5 years, randomising 10 269 participants, with average participant follow-up being 4 years. The primary end point is hospitalisation for the composite end point of non-fatal myocardial infarction (MI), non-fatal stroke (cerebrovascular accident; CVA) or any vascular death determined by record-linkage. Secondary end points are: each component of the primary end point, hospitalisation for non-fatal stroke, hospitalisation for non-fatal MI, cardiovascular death, all-cause mortality, hospitalisation or death from congestive heart failure. The primary outcome will be a comparison of time to first event comparing morning versus evening dosing using an intention-to-treat analysis. The sample size is calculated for a two-sided test to detect 20% superiority at 80% power. Ethics and dissemination TIME has ethical approval in the UK, and results will be published in a

  15. Time-resolved measurement of photon emission during fast crack propagation in three-point bending fracture of silica glass and soda lime glass

    SciTech Connect

    Shiota, Tadashi Sato, Yoshitaka; Yasuda, Kouichi

    2014-03-10

    Simultaneous time-resolved measurements of photon emission (PE) and fast crack propagation upon bending fracture were conducted in silica glass and soda lime glass. Observation of fracture surfaces revealed that macroscopic crack propagation behavior was similar between the silica glass and soda lime glass when fracture loads for these specimens were comparable and cracks propagated without branching. However, a large difference in the PE characteristics was found between the two glasses. In silica glass, PE (645–655 nm) was observed during the entire crack propagation process, whereas intense PE (430–490 nm and 500–600 nm) was observed during the initial stages of propagation. In contrast, only weak PE was detected in soda lime glass. These results show that there is a large difference in the atomic processes involved in fast crack propagation between these glasses, and that PE can be used to study brittle fracture on the atomic scale.

  16. FLOPAK: FLOATING POINT PROGRAMING PACKAGE,

    DTIC Science & Technology

    FLOPAK is a Packard-Bell 250 Computer semi-automatic, floating - point programing system which may be operated simultaneously in either of two modes...250 floating - point system available which may be used in real-time control. The system was originally designed to solve a real-time communication problem....The first is a non-time optimized mode which may be used by inex perienced coders; the second mode is a high-speed, fully time-optimized floating

  17. Acute or Delayed Treatment with Anatabine Improves Spatial Memory and Reduces Pathological Sequelae at Late Time-Points after Repetitive Mild Traumatic Brain Injury.

    PubMed

    Ferguson, Scott; Mouzon, Benoit; Paris, Daniel; Aponte, Destinee; Abdullah, Laila; Stewart, William; Mullan, Michael; Crawford, Fiona

    2017-01-20

    Traumatic brain injury (TBI) has chronic and long-term consequences for which there are currently no approved pharmacological treatments. We have previously characterized the chronic neurobehavioral and pathological sequelae of a mouse model of repetitive mild TBI (r-mTBI) through to 2 years post-TBI. Despite the mild nature of the initial insult, secondary injury processes are initiated that involve neuroinflammatory and neurodegenerative pathways persisting and progressing for weeks and months post-injury and providing a potential window of opportunity for therapeutic intervention. In this study we examined the efficacy of a novel anti-inflammatory compound, anatabine, in modifying outcome after TBI. Our model of r-mTBI involves a series of five mild impacts (midline impact at 5 m/sec, 1 mm strike depth, 200 msec dwell time) with an interval of 48 h. Anatabine treatment was administered starting 30 min after injury and was delivered continuously through drinking water. At 6 months after TBI, anatabine treatment improved spatial memory in injured mice. Nine months after TBI, a cohort of mice was euthanized for pathological analysis that revealed reductions in astroglial (glial fibrillary acid protein, GFAP) and microglial (ionized calcium-binding adapter molecule 1, IBA1) responses in treated, injured animals. Treatments for the remaining mice were then crossed-over to assess the effects of late treatment administration and the effects of treatment termination. Nine months following crossover the remaining mice showed no effect of injury on their spatial memory, and whereas pathological analysis showed improvements in mice that had received delayed treatment, corpus callosum IBA1 increased in post-crossover placebo r-mTBI mice. These data demonstrate efficacy of both early and late initiation of treatment with anatabine in improving long term behavioral and pathology outcomes after mild TBI. Future studies will characterize the treatment window, the time

  18. Early life stress disrupts social behavior and prefrontal cortex parvalbumin interneurons at an earlier time-point in females than in males.

    PubMed

    Holland, Freedom H; Ganguly, Prabarna; Potter, David N; Chartoff, Elena H; Brenhouse, Heather C

    2014-04-30

    Early life stress exposure (ELS) yields risk for psychiatric disorders that might occur though a population-specific mechanism that impacts prefrontal cortical development. Sex differences in ELS effects are largely unknown and are also essential to understand social and cognitive development. ELS can cause dysfunction within parvalbumin (PVB)-containing inhibitory interneurons in the prefrontal cortex and in several prefrontal cortex-mediated behaviors including social interaction. Social behavior deficits are often the earliest observed changes in psychiatric disorders, therefore the time-course and causation of social interaction deficits after ELS are important to determine. PVB interneuron dysfunction can disrupt social behavior, and has been correlated in males with elevated markers of oxidative stress and inflammation, such as cyclooxygenase-2 after ELS. Here, we measured the effects of maternal separation ELS on social interaction behaviors in males and females. Prefrontal cortex PVB and cyclooxygenase-2 were also measured in juveniles and adolescents using Western blots. ELS led to social interaction alterations earlier in females than males. Sexually dimorphic behavioral changes were consistent with prefrontal cortex PVB loss after ELS. PVB levels were decreased in ELS-exposed juvenile females, while males exposed to ELS do not display parvalbumin decreases until adolescence. Early behavioral and PVB changes in females did not appear to be mediated through cyclooxygenase-2, since levels were not affected in ELS females. Therefore, these data suggest that ELS affects males and females differently and with distinct developmental profiles.

  19. Evaluation of point mutation detection in Mycobacterium tuberculosis with isoniazid resistance using real-time PCR and TaqMan probe assay.

    PubMed

    Riahi, F; Derakhshan, M; Mosavat, A; Soleimanpour, S; Rezaee, S A

    2015-03-01

    Rapid methods for diagnosis of Mycobacterium tuberculosis (Mtb) drug resistance and choosing appropriate antibiotic treatment are pivotal. Thirty isoniazid (INH)-resistant and 30 INH-susceptible Mtb isolates were evaluated using minimum inhibitory concentration (MIC) method followed by multiplex real-time PCR (RT-PCR). Amplification refractory mutation system (ARMS) for detection of mutation in 315 codon of katG gene and single-nucleotide polymorphism (SNP) for detection of mutation in -15 (C>T) in the regulatory zone of mabA-inhA were carried out using the TaqMan method. Primers and probe were used for IS6110 region of Mtb as an internal amplification control. The sensitivity and specificity of the RT-PCR TaqMan probe for detection of Mtb complex were 100 %. Detection of INH-resistant Mtb using the ARMS method for KatG had 69 % sensitivity and 100 % specificity. The sensitivity and specificity of SNP in mabA-inhA fragment for detection of INH-resistant Mtb were 53 and 100 %, respectively. Furthermore, considering both regions, the sensitivity of RT-PCR has increased to 75 %. This study revealed that the qPCR-TaqMan method can be used as a standard tool for diagnosis of Mtb. Moreover, ARMS and SNP RT-PCR TaqMan methods can be used as rapid screening methods for detection of INH-resistant Mtb.

  20. Space-time design of the tangled C-points and optical vortex chain and loop reactions in paraxial dynamic elliptic speckle fields

    NASA Astrophysics Data System (ADS)

    Soskin, Marat S.; Vasil'ev, Vasil I.

    2013-04-01

    The unique effect of ‘optical damage’ in photorefractive LiNbO3:Fe crystals produces a developing speckle field in the propagating beam of a He-Ne laser (0.63 μm). Elliptic developing speckle fields were created and investigated thoroughly by means of the Stokes polarimetry and monstardom (Dennis 2008 Opt. Lett. 33 2572). The ergodicity of elliptic speckle fields under the index (star, monstar, lemon) and contour (elliptic, hyperbolic) classifications was revealed experimentally by our measurements for developing speckle fields, measurements for static elliptic speckle fields, as well as theory (Flossmann et al 2008 Phys. Rev. Lett. 100 203902). Both hyperbolic (H) and elliptic (E) diabolos were fixed. All the probable topological structures for the neighbour diabolos in the developing elliptic speckle field were measured. All the measured nucleation/annihilation events occur as H(S)+H(M) reactions. The evolution of the singularities occurs separately in the speckle-field areas with fixed handedness and is realized through minimizing the changes needed for the developing speckle fields at each moment. The general regularities of the elliptic speckle-field development were revealed and confirmed. They occur through the time-limited loop and continuous chain reactions in both single and multiple speckles in 1:4 proportion. Strict morphological scenarios for their evolution were found. Applications of the methods of dynamical singular optics are discussed.

  1. My starting point: the discovery of an NMR method for measuring blood oxygenation using the transverse relaxation time of blood water.

    PubMed

    Thulborn, Keith R

    2012-08-15

    This invited personal story, covering the period from 1979 to 2010, describes the discovery of the dependence of the transverse relaxation time of water in blood on the oxygenation state of hemoglobin in the erythrocytes. The underlying mechanism of the compartmentation of the different magnetic susceptibilities of hemoglobin in its different oxygenation states also explains the mechanism that underlies blood oxygenation level dependent contrast used in fMRI. The story begins with the initial observation of line broadening during ischemia in small rodents detected by in vivo 31P NMR spectroscopy at high field. This spectroscopic line broadening or T2* relaxation effect was demonstrated to be related to the oxygenation state of blood. The effect was quantified more accurately using T2 values measured by the Carr-Purcell-Meiboom-Gill method. The effect was dependent on the integrity of the erythrocytes to compartmentalize the different magnetic susceptibilities produced by the changing spin state of the ferrous iron of hemoglobin in its different oxygenation states between the erythrocytes and the suspending solution. The hematocrit and magnetic field dependence, the requirement for erythrocyte integrity and lack of T1 dependence confirmed that the magnetic susceptibility effect explained the oxygenation state dependence of T2* and T2. This T2/T2* effect was combined with T1 based measurements of blood flow to measure oxygen consumption in animals. This blood oxygenation assay and its underlying magnetic susceptibility gradient mechanism was published in the biochemistry literature in 1982 and largely forgotten. The observation was revived to explain evolving imaging features of cerebral hematoma as MR imaging of humans increased in field strength to 1.5 T by the mid 1980s. Although the imaging version of this assay was used to measure a global metabolic rate of cerebral oxygen consumption in humans at 1.5-T by 1991, the global measurement had little clinical value

  2. Effects of immunological castration and distiller's dried grains with solubles on carcass cutability and commercial bacon slicing yields of barrows slaughtered at two time points.

    PubMed

    Tavárez, M A; Bohrer, B M; Asmus, M D; Schroeder, A L; Matulis, R J; Boler, D D; Dilger, A C

    2014-07-01

    Male pigs were randomly assigned to a castration method at birth and allotted to 48 pens (28 pigs/pen). Physically castrated (PC) barrows were castrated at 2 d of age; immunologically castrated (IC) barrows were administered Improvest (GnRF analog diphtheria toxoid conjugate; Zoetis, Kalamazoo, MI) at 16 and 20 wk of age. Distiller's dried grains with solubles (DDGS) feeding strategies included either 0% DDGS (control), 30% DDGS (30% DDGS) fed from 6 wk of age to slaughter, or 30% DDGS fed from 6 wk of age to second dose of Improvest and then fed 0% DDGS until slaughter (withdrawal). Four barrows closest to the median pen weight at 4.5 wk after second dose were selected for evaluation; two were randomly selected and slaughtered at 5 wk and the other two at 7 wk after second dose. Data from each slaughter time were analyzed independently as a 2 × 3 factorial design with pen as the experimental unit. At 5 wk after second dose, bone-in lean cutting yields were 2.63% units greater (P < 0.01) in IC when compared to PC. Bellies were thicker (P < 0.01) and tended to have greater belly flop distances (P = 0.07) in PC compared to IC, however iodine values (IV) were not altered (P = 0.84). Carcass traits (P ≥ 0.10), cutting yields (P ≥ 0.43), and fresh belly characteristics (P ≥ 0.08) were minimally affected by DDGS feeding strategy. Bacon slicing yields (percentage of green weight) were 6.10% units less (P < 0.01) in IC compared with PC. At 7 wk after second dose, bone-in lean cutting yields were 1.57% units greater (P = 0.03) in IC compared with PC. Distiller's grains feeding strategy had no effect (P ≥ 0.83) on boneless carcass cutting yields in IC; while in PC, these yields were 2.32% units less (P < 0.02) in control-fed barrows when compared to other feeding strategies (castration method × feeding strategy; P = 0.03). Bellies from PC tended to be thicker (P = 0.07) and have similar flop distances (P = 0.44) and IV (P = 0.54) when compared with IC. Iodine value

  3. Imaging study on acupuncture points

    NASA Astrophysics Data System (ADS)

    Yan, X. H.; Zhang, X. Y.; Liu, C. L.; Dang, R. S.; Ando, M.; Sugiyama, H.; Chen, H. S.; Ding, G. H.

    2009-09-01

    The topographic structures of acupuncture points were investigated by using the synchrotron radiation based Dark Field Image (DFI) method. Four following acupuncture points were studied: Sanyinjiao, Neiguan, Zusanli and Tianshu. We have found that at acupuncture point regions there exists the accumulation of micro-vessels. The images taken in the surrounding tissue out of the acupuncture points do not show such kind of structure. It is the first time to reveal directly the specific structure of acupuncture points by X-ray imaging.

  4. Oscillating stagnation point flow

    NASA Technical Reports Server (NTRS)

    Grosch, C. E.; Salwen, H.

    1982-01-01

    A solution of the Navier-Stokes equations is given for an incompressible stagnation point flow whose magnitude oscillates in time about a constant, non-zero, value (an unsteady Hiemenz flow). Analytic approximations to the solution in the low and high frequency limits are given and compared with the results of numerical integrations. The application of these results to one aspect of the boundary layer receptivity problem is also discussed.

  5. Oscillating stagnation point flow

    NASA Astrophysics Data System (ADS)

    Grosch, C. E.; Salwen, H.

    1982-11-01

    A solution of the Navier-Stokes equations is given for an incompressible stagnation point flow whose magnitude oscillates in time about a constant, non-zero, value (an unsteady Hiemenz flow). Analytic approximations to the solution in the low and high frequency limits are given and compared with the results of numerical integrations. The application of these results to one aspect of the boundary layer receptivity problem is also discussed.

  6. Accurate pointing of tungsten welding electrodes

    NASA Technical Reports Server (NTRS)

    Ziegelmeier, P.

    1971-01-01

    Thoriated-tungsten is pointed accurately and quickly by using sodium nitrite. Point produced is smooth and no effort is necessary to hold the tungsten rod concentric. The chemically produced point can be used several times longer than ground points. This method reduces time and cost of preparing tungsten electrodes.

  7. Effect of Receiver Choosing on Point Positions Determination in Network RTK

    NASA Astrophysics Data System (ADS)

    Bulbul, Sercan; Inal, Cevat

    2016-04-01

    Nowadays, the developments in GNSS technique allow to determinate point positioning in real time. Initially, point positioning was determined by RTK (Real Time Kinematic) based on a reference station. But, to avoid systematic errors in this method, distance between the reference points and rover receiver must be shorter than10 km. To overcome this restriction in RTK method, the idea of setting more than one reference point had been suggested and, CORS (Continuously Operations Reference Systems) was put into practice. Today, countries like ABD, Germany, Japan etc. have set CORS network. CORS-TR network which has 146 reference points has also been established in 2009 in Turkey. In CORS-TR network, active CORS approach was adopted. In Turkey, CORS-TR reference stations covering whole country are interconnected and, the positions of these stations and atmospheric corrections are continuously calculated. In this study, in a selected point, RTK measurements based on CORS-TR, were made with different receivers (JAVAD TRIUMPH-1, TOPCON Hiper V, MAGELLAN PRoMark 500, PENTAX SMT888-3G, SATLAB SL-600) and with different correction techniques (VRS, FKP, MAC). In the measurements, epoch interval was taken as 5 seconds and measurement time as 1 hour. According to each receiver and each correction technique, means and differences between maximum and minimum values of measured coordinates, root mean squares in the directions of coordinate axis and 2D and 3D positioning precisions were calculated, the results were evaluated by statistical methods and the obtained graphics were interpreted. After evaluation of the measurements and calculations, for each receiver and each correction technique; the coordinate differences between maximum and minimum values were measured to be less than 8 cm, root mean squares in coordinate axis directions less than ±1.5 cm, 2D point positioning precisions less than ±1.5 cm and 3D point positioning precisions less than ±1.5 cm. In the measurement

  8. The Point of No Return

    PubMed Central

    Logan, Gordon D.

    2015-01-01

    Bartlett (1958) described the point of no return as a point of irrevocable commitment to action, which was preceded by a period of gradually increasing commitment. As such, the point of no return reflects a fundamental limit on the ability to control thought and action. I review the literature on the point of no return, taking three perspectives. First, I consider the point of no return from the perspective of the controlled act, as a locus in the architecture and anatomy of the underlying processes. I review experiments from the stop-signal paradigm that suggest that the point of no return is located late in the response system. Then I consider the point of no return from the perspective of the act of control that tries to change the controlled act before it becomes irrevocable. From this perspective, the point of no return is a point in time that provides enough “lead time” for the act of control to take effect. I review experiments that measure the response time to the stop signal as the lead time required for response inhibition in the stop-signal paradigm. Finally, I consider the point of no return in hierarchically controlled tasks, in which there may be many points of no return at different levels of the hierarchy. I review experiments on skilled typing that suggest different points of no return for the commands that determine what is typed and the countermands that inhibit typing, with increasing commitment to action the lower the level in the hierarchy. I end by considering the point of no return in perception and thought as well as action. PMID:25633089

  9. Point set registration: coherent point drift.

    PubMed

    Myronenko, Andriy; Song, Xubo

    2010-12-01

    Point set registration is a key component in many computer vision tasks. The goal of point set registration is to assign correspondences between two sets of points and to recover the transformation that maps one point set to the other. Multiple factors, including an unknown nonrigid spatial transformation, large dimensionality of point set, noise, and outliers, make the point set registration a challenging problem. We introduce a probabilistic method, called the Coherent Point Drift (CPD) algorithm, for both rigid and nonrigid point set registration. We consider the alignment of two point sets as a probability density estimation problem. We fit the Gaussian mixture model (GMM) centroids (representing the first point set) to the data (the second point set) by maximizing the likelihood. We force the GMM centroids to move coherently as a group to preserve the topological structure of the point sets. In the rigid case, we impose the coherence constraint by reparameterization of GMM centroid locations with rigid parameters and derive a closed form solution of the maximization step of the EM algorithm in arbitrary dimensions. In the nonrigid case, we impose the coherence constraint by regularizing the displacement field and using the variational calculus to derive the optimal transformation. We also introduce a fast algorithm that reduces the method computation complexity to linear. We test the CPD algorithm for both rigid and nonrigid transformations in the presence of noise, outliers, and missing points, where CPD shows accurate results and outperforms current state-of-the-art methods.

  10. Coupling high resolution 3D point clouds from terrestrial LiDAR with high precision displacement time series from GB-InSAR to understand landslide kinematic: example of the La Perraire instability, Swiss Alps.

    NASA Astrophysics Data System (ADS)

    Michoud, Clément; Baillifard, François; Harald Blikra, Lars; Derron, Marc-Henri; Jaboyedoff, Michel; Kristensen, Lene; Leva, Davide; Metzger, Richard; Rivolta, Carlo

    2014-05-01

    Terrestrial Laser Scanning and Ground-Based Radar Interferometry have changed our perception and interpretation of slope activities for the last 20 years and are now routinely used for monitoring and even early warning purposes. Terrestrial LiDAR allows indeed to model topography with very high point density, even in steep slopes, and to extract 3D displacements of rock masses by comparing successive datasets. GB-InSAR techniques are able to detect mm displacements over large areas. Nevertheless, both techniques suffer of some limitations. The precision of LiDAR devices actually limits its ability to monitor very slow-moving landslides, as well as by the dam resolution and the particular geometry (in azimuth/range) of GB-InSAR data may complicate their interpretations. To overcome those limitations, tools were produced to truly combine strong advantages of both techniques, by coupling high resolution geometrical data from terrestrial LiDAR or photogrammetry with high precision displacement time series from GB-InSAR. We thus developed a new exportation module into the processing chain of LiSAmobile (GB-InSAR) devices in order to wrap radar results from their particular geometry on high resolution 3D point clouds with cm mean point spacing. Furthermore, we also added new importation and visualization functionalities into Coltop3D (software for geological interpretations of laser scanning data) to display those results in 3D and even analyzing displacement time series. This new method has also been optimized to create as few and small files as possible and for time processing. Advantages of coupling terrestrial LiDAR and GB-InSAR data will be illustrated on the La Perraire instability, an active large rockslide involving frequent rockfalls and threatening inhabitant within the Val de Bagnes in the Swiss Alps. This rock mass, monitored by LiDAR and GPS since 2006, is huge enough and long-term movements are big (up to 1.6 m in 6 years) and complex enough to make

  11. Assessment of the usefulness of the standardized uptake values and the radioactivity levels for the preoperative diagnosis of thyroid cancer measured by using 18F-FDG PET/CT dual-time-point imaging

    NASA Astrophysics Data System (ADS)

    Lee, Hyeon-Guck; Hong, Seong-Jong; Cho, Jae-Hwan; Han, Man-Seok; Kim, Tae-Hyung; Lee, Ik-Han

    2013-02-01

    The purpose of this study was to assess and compare the changes in the SUV (standardized uptake value), the 18F-FDG (18F-fluorodeoxyglucose) uptake pattern, and the radioactivity level for the diagnosis of thyroid cancer via dual-time-point 18F-FDG PET/CT (positron emission tomographycomputed tomography) imaging. Moreover, the study aimed to verify the usefulness and significance of SUV values and radioactivity levels to discriminate tumor malignancy. A retrospective analysis was performed on 40 patients who received 18F-FDG PET/CT for thyroid cancer as a primary tumor. To set the background, we compared changes in values by calculating the dispersion of scattered rays in the neck area and the lung apex, and by comparing the mean and SD (standard deviation) values of the maxSUV and the radioactivity levels. According to the statistical analysis of the changes in 18F-FDG uptake for the diagnosis of thyroid cancer, a high similarity was observed with the coefficient of determination being R2 = 0.939, in the SUVs and the radioactivity levels. Moreover, similar results were observed in the assessment of tumor malignancy using dual-time-point. The quantitative analysis method for assessing tumor malignancy using radioactivity levels was neither specific nor discriminative compared to the semi-quantitative analysis method.

  12. Relationships among rat ultrasonic vocalizations, behavioral measures of striatal dopamine loss, and striatal tyrosine hydroxylase immunoreactivity at acute and chronic time points following unilateral 6-hydroxydopamine-induced dopamine depletion.

    PubMed

    Grant, Laura M; Barnett, David G; Doll, Emerald J; Leverson, Glen; Ciucci, Michelle

    2015-09-15

    Voice deficits in Parkinson disease (PD) emerge early in the disease process, but do not improve with standard treatments targeting dopamine. Experimental work in the rat shows that severe and chronic unilateral nigrostriatal dopamine depletion with 6-OHDA results in decreased intensity, bandwidth, and complexity of ultrasonic vocalizations. However, it is unclear if mild/acute dopamine depletion, paralleling earlier stages of PD, results in vocalization deficits, or to what degree vocalization parameters are correlated with other dopamine-dependent indicators of lesion severity or percent of tyrosine hydroxylase (%TH) loss. Here, we assayed ultrasonic vocalizations, forelimb asymmetry, and apomorphine rotations in rats with a range of unilateral dopamine loss resulting from 6-OHDA or vehicle control infusions to the medial forebrain bundle at acute (72 h) and chronic (4 weeks) time points post-infusion. The %TH loss was evaluated at 4 weeks. At 72 h, forelimb asymmetry and %TH loss were significantly correlated, while at 4 weeks, all measures of lesion severity were significantly correlated with each other. Call complexity was significantly correlated with all measures of lesion severity at 72 h but only with %TH loss at 4 weeks. Bandwidth was correlated with forelimb asymmetry at both time points. Duration was significantly correlated with all dopamine depletion measures at 4 weeks. Notably, not all parameters were affected universally or equally across time. These results suggest that vocalization deficits may be a sensitive index of acute and mild catecholamine loss and further underscores the need to characterize the neural mechanisms underlying vocal deficits in PD.

  13. Glufosfamide administered using a 1-hour infusion given as first-line treatment for advanced pancreatic cancer. A phase II trial of the EORTC-new drug development group.

    PubMed

    Briasoulis, E; Pavlidis, N; Terret, C; Bauer, J; Fiedler, W; Schöffski, P; Raoul, J L; Hess, D; Selvais, R; Lacombe, D; Bachmann, P; Fumoleau, P

    2003-11-01

    The activity of glufosfamide (beta-D-glucopyranosyl-N,N'-di-(2-chloroethyl)-phosphoric acid diamide) against pancreatic cancer was investigated in a multicentre, phase II clinical study. Chemotherapy-nai;ve patients with advanced or metastatic disease were treated with glufosfamide (5 g/m(2)) using a 1-h intravenous (i.v.) infusion every 3 weeks. Patients were randomised between active-hydration and normal fluids to evaluate the nephroprotective effect of forced diuresis. Patients experiencing >0.4 mg/dl (>35 micromol/l) increase in serum creatinine compared with their baseline value were taken off treatment for safety reasons. The evaluation of response was according to the Response evaluation criteria in solid tumours (RECIST). Blood sampling was performed for pharmacokinetic analyses. 35 patients from 13 institutions were registered over a 13-month period. A total of 114 treatment cycles (median 3, range 1-8) were administered to 34 patients; 18 patients were allocated to the hydration arm. Overall haematological toxicity was mild. Metabolic acidosis occurred in 2 patients treated in the active-hydration arm, grade 3 hypokalaemia was recorded in 5 patients and grade 3 hypophosphataemia in 4 patients. One patient had a grade 4 increase in serum creatinine level, concomitantly to disease progression. Active-hydration did not show a nephroprotective effect and the plasma pharmacokinetics (Pk) of glufosfamide was not significantly influenced by hydration. Two confirmed partial remissions (PR) were reported (response rate 5.9%, 95% Confidence Interval (CI) 0.7-19.7%) and 11 cases obtained disease stabilisation (32.4%). An extra mural review panel confirmed all of the responses. Median overall survival was 5.3 months (95% CI 3.9-7.1) and time to progression (TTP) was 1.4 months (95% CI 1.3-2.7). In conclusion, glufosfamide administered using a 1-h infusion every 3 weeks has a modest activity in advanced pancreatic adenocarcinoma. Haematological toxicity is

  14. Screen Time May Not Be So Bad for Teens After All

    MedlinePlus

    ... hours of screen time every day -- on video games, smartphones, computers, TV and the like -- may not ... in one of these daily scenarios: Playing video games for about 1 hour and 40 minutes, Fooling ...

  15. Characterizing configurations of fire ignition points through spatiotemporal point processes

    NASA Astrophysics Data System (ADS)

    Comas, C.; Costafreda-Aumedes, S.; Vega-Garcia, C.

    2014-04-01

    Human-caused forest fires are usually regarded as unpredictable but often exhibit trends towards clustering in certain locations and periods. Characterizing such configurations is crucial for understanding spatiotemporal fire dynamics and implementing preventive actions. Our objectives were to analyse the spatiotemporal point configuration and to test for spatiotemporal interaction. We characterized the spatiotemporal structure of 984 fire ignition points in a study area of Galicia, Spain, during 2007-2011 by the K-Ripley's function. Our results suggest the presence of spatiotemporal structures for time lags of less than two years and ignition point distances in the range 0-12 km. Ignition centre points at time lags of less than 100 days are aggregated for any inter-event distance. This cluster structure loses strength as the time lag increases, and at time lags of more than 365 days this cluster structure is not significant for any lag distance. Our results also suggest spatiotemporal interdependencies at time lags of less than 100 days and inter-event distances of less than 10 km. At time lags of up to 365 days spatiotemporal components are independent for any point distance. These results suggest that risk conditions occur locally and are short-lived in this study area.

  16. Two alternative multiplex PCRs for the identification of the seven species of anglerfish (Lophius spp.) using an end-point or a melting curve analysis real-time protocol.

    PubMed

    Castigliego, Lorenzo; Armani, Andrea; Tinacci, Lara; Gianfaldoni, Daniela; Guidi, Alessandra

    2015-01-01

    Anglerfish (Lophius spp.) is consumed worldwide and is an important economic resource though its seven species are often fraudulently interchanged due to their different commercial value, especially when sold in the form of fillets or pieces. Molecular analysis is the only possible mean to verify traceability and counteract fraud. We developed two multiplex PCRs, one end-point and one real-time with melting curve post-amplification analysis, which can even be run with the simplest two-channel thermocyclers. The two methods were tested on seventy-five reference samples. Their specificity was checked in twenty more species of those most commonly available on the market and in other species of the Lophiidae family. Both methods, the choice of which depends on the equipment and budget of the lab, provide a rapid and easy-to-read response, improving both the simplicity and cost-effectiveness of existing methods for identifying Lophius species.

  17. Kikuchi-Fujimoto Disease with 18F-Fludeoxyglucose Uptake in Cervical Lymph Nodes on Dual-time-point Imaging Positron Emission Tomography/Computed Tomography Mimicking Malignant Disease

    PubMed Central

    Aoyama, Ken-ichi; Otsuru, Mitsunobu; Uchibori, Masahiro; Ota, Yoshihide

    2017-01-01

    Kikuchi-Fujimoto disease (KFD) is a benign but self-limiting disorder. However, KFD is often misdiagnosed as a malignant disease. Although 18F-fludeoxyglucose (FDG) uptake on dual-time-point imaging (DTPI) positron emission tomography (PET)/computed tomography (CT) is useful in distinguishing malignant from benign disease, the latter sometimes mimics malignancy on DTPI PET/CT, resulting in a misdiagnosis. Here, we describe the case of a 30-year-old woman who complained of cervical lymphadenopathy. PET showed increased FDG uptake in multiple lymph nodes, with a maximum standardized uptake value (SUVmax) of 19.0 in the early phase to 21.8 in the late phase. A biopsy was performed, and pathological examination revealed KFD. KFD with FDG uptake in lymph nodes on DTPI PET/CT is rare and difficult to be distinguished from a malignant disease. PMID:28217024

  18. Is It Possible to Detect Activated Brown Adipose Tissue in Humans Using Single-Time-Point Infrared Thermography under Thermoneutral Conditions? Impact of BMI and Subcutaneous Adipose Tissue Thickness

    PubMed Central

    Gatidis, Sergios; Schmidt, Holger; Pfannenberg, Christina A.; Nikolaou, Konstantin; Schick, Fritz; Schwenzer, Nina F.

    2016-01-01

    Purpose To evaluate the feasibility to detect activated brown adipose tissue (BAT) using single-time-point infrared thermography of the supraclavicular skin region under thermoneutral conditions. To this end, infrared thermography was compared with 18-F-FDG PET, the current reference standard for the detection of activated BAT. Methods 120 patients were enrolled in this study. After exclusion of 18 patients, 102 patients (44 female, 58 male, mean age 58±17 years) were included for final analysis. All patients underwent a clinically indicated 18F-FDG-PET/CT examination. Immediately prior to tracer injection skin temperatures of the supraclavicular, presternal and jugular regions were measured using spatially resolved infrared thermography at room temperature. The presence of activated BAT was determined in PET by typical FDG uptake within the supraclavicular adipose tissue compartments. Local thickness of supraclavicular subcutaneous adipose tissue (SCAT) was measured on CT. Measured skin temperatures were statistically correlated with the presence of activated BAT and anthropometric data. Results Activated BAT was detected in 9 of 102 patients (8.8%). Local skin temperature of the supraclavicular region was significantly higher in individuals with active BAT compared to individuals without active BAT. However, after statistical correction for the influence of BMI, no predictive value of activated BAT on skin temperature of the supraclavicular region could be observed. Supraclavicular skin temperature was significantly negatively correlated with supraclavicular SCAT thickness. Conclusion We conclude that supraclavicular SCAT thickness influences supraclavicular skin temperature and thus makes a specific detection of activated BAT using single-time-point thermography difficult. Further studies are necessary to evaluate the possibility of BAT detection using alternative thermographic methods, e.g. dynamic thermography or MR-based thermometry taking into account BMI

  19. Vernal Point and Anthropocene

    NASA Astrophysics Data System (ADS)

    Chavez-Campos, Teodosio; Chavez S, Nadia; Chavez-Sumarriva, Israel

    2014-05-01

    The time scale was based on the internationally recognized formal chronostratigraphical /geochronological subdivisions of time: The Phanerozoic Eonathem/Eon; the Cenozoic Erathem/Era; the Quaternary System/Period; the Pleistocene and Holocene Series/Epoch. The Quaternary was divided into: (1) The Pleistocene that was characterized by cycles of glaciations (intervals between 40,000 and 100,000 years). (2) The Holocene that was an interglacial period that began about 12,000 years ago. It was believed that the Milankovitch cycles (eccentricity, axial tilt and the precession of the equinoxes) were responsible for the glacial and interglacial Holocene periods. The magnetostratigraphic units have been widely used for global correlations valid for Quaternary. The gravitational influence of the sun and moon on the equatorial bulges of the mantle of the rotating earth causes the precession of the earth. The retrograde motion of the vernal point through the zodiacal band is 26,000 years. The Vernal point passes through each constellation in an average of 2000 years and this period of time was correlated to Bond events that were North Atlantic climate fluctuations occurring every ≡1,470 ± 500 years throughout the Holocene. The vernal point retrogrades one precessional degree approximately in 72 years (Gleissberg-cycle) and approximately enters into the Aquarius constellation on March 20, 1940. On earth this entry was verify through: a) stability of the magnetic equator in the south central zone of Peru and in the north zone of Bolivia, b) the greater intensity of equatorial electrojet (EEJ) in Peru and Bolivia since 1940. With the completion of the Holocene and the beginning of the Anthropocene (widely popularized by Paul Crutzen) it was proposed the date of March 20, 1940 as the beginning of the Anthropocene. The date proposed was correlated to the work presented in IUGG (Italy 2007) with the title "Cusco base meridian for the study of geophysical data"; Cusco was

  20. 76 FR 66925 - Guidance for 1-Hour SO2

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-28

    ..., identified by Docket ID No. EPA-HQ- OAR-2010-1059, by one of the following methods: http://www.regulations... . Attention Docket ID No. EPA-HQ-OAR-2010-1059. Fax: (202) 566-9744. Attention Docket ID No. EPA-HQ-OAR- 2010-1059. Mail: Air Docket, Attention Docket ID No. EPA-HQ-OAR-2010- 1059, Environmental Protection...

  1. 76 FR 61098 - Guidance for 1-Hour SO2

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-03

    ... Docket ID No. EPA-HQ- OAR-2010-1059, by one of the following methods: http://www.regulations.gov . Follow... No. EPA-HQ-OAR-2010-1059. Fax: 202-566-9744. Attention Docket ID No. EPA-HQ-OAR- 2010-1059. Mail: Air Docket, Attention Docket ID No. EPA-HQ-OAR-2010- 1059, Environmental Protection Agency, Mail Code:...

  2. Ocular torsion before and after 1 hour centrifugation.

    PubMed

    Groen, E; De Graaf, B; Bles, W; Bos, J E

    1996-01-01

    To assess a possible otolith contribution to effects observed following prolonged exposure to hypergravity, we used video oculography to measure ocular torsion during static and dynamic conditions of lateral body tilt (roll) before and after 1 h of centrifugation with a Gx-load of 3 G. Static tilt (from 0 to 57 degrees to either side) showed a 10% decrease in otolith-induced ocular torsion after centrifugation. This implies a reduced gain of the otolith function. The dynamic condition consisted of sinusoidal body roll (frequency 0.25 Hz, amplitude 45 degrees) about an earth horizontal and about an earth vertical axis (respectively, "with" and "without" otolith stimulation). Before centrifugation the gain of the slow component velocity (SCV) was significantly lower "with" otolith stimulation than "without" otolith stimulation. Apparently, the contribution of the otoliths counteracts the ocular torsion response generated by the semicircular canals. Therefore, the observed increase in SCV gain in the condition "with" otolith stimulation after centrifugation, seems in correspondence with the decreased otolith gain in the static condition.

  3. A New Look at Trigger Point Injections

    PubMed Central

    Wong, Clara S. M.; Wong, Steven H. S.

    2012-01-01

    Trigger point injections are commonly practised pain interventional techniques. However, there is still lack of objective diagnostic criteria for trigger points. The mechanisms of action of trigger point injection remain obscure and its efficacy remains heterogeneous. The advent of ultrasound technology in the noninvasive real-time imaging of soft tissues sheds new light on visualization of trigger points, explaining the effect of trigger point injection by blockade of peripheral nerves, and minimizing the complications of blind injection. PMID:21969825

  4. SPS antenna pointing control

    NASA Technical Reports Server (NTRS)

    Hung, J. C.

    1980-01-01

    The pointing control of a microwave antenna of the Satellite Power System was investigated emphasizing: (1) the SPS antenna pointing error sensing method; (2) a rigid body pointing control design; and (3) approaches for modeling the flexible body characteristics of the solar collector. Accuracy requirements for the antenna pointing control consist of a mechanical pointing control accuracy of three arc-minutes and an electronic phased array pointing accuracy of three arc-seconds. Results based on the factors considered in current analysis, show that the three arc-minute overall pointing control accuracy can be achieved in practice.

  5. Deconfined Quantum Critical Points

    NASA Astrophysics Data System (ADS)

    Senthi, T.; Vishwanath, Ashvin; Balents, Leon; Sachdev, Subir; Fisher, Matthew P. A.

    The theory of second-order phase transitions is one of the foundations of modern statistical mechanics and condensed-matter theory. A central concept is the observable order parameter, whose nonzero average value characterizes one or more phases. At large distances and long times, fluctuations of the order parameter(s) are described by a continuum field theory, and these dominate the physics near such phase transitions. We show that near second-order quantum phase transitions, subtle quantum interference effects can invalidate this paradigm, and we present a theory of quantum critical points in a variety of experimentally relevant two-dimensional antiferromagnets. The critical points separate phases characterized by conventional "confining" order parameters. Nevertheless, the critical theory contains an emergent gauge field and "deconfined" degrees of freedom associated with fractionalization of the order parameters. We propose that this paradigm for quantum criticality may be the key to resolving a number of experimental puzzles in correlated electron systems and offer a new perspective on the properties of complex materials.

  6. Repelling Point Bosons

    NASA Astrophysics Data System (ADS)

    McGuire, J. B.

    2011-12-01

    There is a body of conventional wisdom that holds that a solvable quantum problem, by virtue of its solvability, is pathological and thus irrelevant. It has been difficult to refute this view owing to the paucity of theoretical constructs and experimental results. Recent experiments involving equivalent ions trapped in a spatial conformation of extreme anisotropic confinement (longitudinal extension tens, hundreds or even thousands of times transverse extension) have modified the view of relevancy, and it is now possible to consider systems previously thought pathological, in particular point Bosons that repel in one dimension. It has been difficult for the experimentalists to utilize existing theory, mainly due to long-standing theoretical misunderstanding of the relevance of the permutation group, in particular the non-commutativity of translations (periodicity) and transpositions (permutation). This misunderstanding is most easily rectified in the case of repelling Bosons.

  7. Translation of a laboratory-validated equine herpesvirus-1 specific real-time PCR assay into an insulated isothermal polymerase chain reaction (iiPCR) assay for point-of-need diagnosis using POCKIT™ nucleic acid analyzer.

    PubMed

    Balasuriya, Udeni B R; Lee, Pei-Yu Alison; Tsai, Yun-Long; Tsai, Chuan-Fu; Shen, Yu-Han; Chang, Hsiao-Fen Grace; Skillman, Ashley; Wang, Hwa-Tang Thomas; Pronost, Stéphane; Zhang, Yan

    2017-03-01

    Equine herpesvirus myeloencephalopathy (EHM), a major problem for the equine industry in the United States, is caused by equine herpesvirus-1 (EHV-1). In addition, EHV-1 is associated with upper respiratory disease, abortion, and chorioretinal lesions in horses. Here we describe the development and evaluation of an inexpensive, user-friendly insulated isothermal PCR (iiPCR) method targeting open reading 30 (ORF30) to detect both neuropathogenic and non-neuropathogenic strains on the field-deployable POCKIT™ device for point-of-need detection of EHV-1. The analytical sensitivity of the EHV-1 iiPCR assay was 13 genome equivalents per reaction. The assay did not cross react with ten non-target equine viral pathogens. Performance of the EHV-1 iiPCR assay was compared to two previously described real-time PCR (qPCR) assays in two laboratories by using 104 archived clinical samples. All 53 qPCR-positive and 46 of the 51 qPCR-negative samples tested positive and negative, respectively, by the iiPCR. The agreement between the two assays was 95.19% (confidence interval 90.48-99.90%) with a kappa value of 0.90. In conclusion, the newly developed EHV-1 iiPCR assay is robust to provide specificity and sensitivity comparable to qPCR assays for the detection of EHV-1 nucleic acid in clinical specimens.

  8. The hippocampus plays a role in the recognition of visual scenes presented at behaviorally relevant points in time: evidence from amnestic mild cognitive impairment (aMCI) and healthy controls.

    PubMed

    Szamosi, András; Levy-Gigi, Einat; Kelemen, Oguz; Kéri, Szabolcs

    2013-01-01

    When people perform an attentionally demanding target task at fixation, they also encode the surrounding visual environment, which serves as a context of the task. Here, we examined the role of the hippocampus in memory for target and context. Thirty-five patients with amnestic mild cognitive impairment (aMCI) and 35 healthy controls matched for age, gender, and education participated in the study. Participants completed visual letter detection and auditory tone discrimination target tasks, while also viewing a series of briefly presented urban and natural scenes. For the measurement of hippocampal and cerebral cortical volume, we utilized the FreeSurfer protocol using a Siemens Trio 3 T scanner. Before the quantification of brain volumes, hippocampal atrophy was confirmed by visual inspection in each patient. Results revealed intact letter recall and tone discrimination performances in aMCI patients, whereas they showed severe impairments in the recognition of scenes presented together with the targets. Patients with aMCI showed bilaterally reduced hippocampal volumes, but intact cortical volume, as compared with the controls. In controls and in the whole sample, hippocampal volume was positively associated with scene recognition when a target task was present. This relationship was observed in both visual and auditory conditions. Scene recognition and target tasks were not associated with executive functions. These results suggest that the hippocampus plays an essential role in the formation of memory traces of the visual environment when people concurrently perform a target task at behaviorally relevant points in time.

  9. Regulation of expression of Sertoli cell glucose transporters 1 and 3 by FSH, IL1 beta, and bFGF at two different time-points in pubertal development.

    PubMed

    Galardo, María Noel; Riera, María Fernanda; Pellizzari, Eliana Herminia; Chemes, Héctor Edgardo; Venara, Marcela Cristina; Cigorraga, Selva Beatriz; Meroni, Silvina Beatriz

    2008-11-01

    Sertoli cells are necessary to provide adequate levels of lactate for germ cell development. Lactate production is hormonally regulated by follicle-stimulating hormone (FSH) and by a large set of intratesticular regulators such as interleukin-1 beta (IL1 beta) and basic fibroblast growth factor (bFGF). Little is known regarding the critical step in the production of this metabolite, viz., the entrance of glucose into the cell as mediated by GLUTs. The aim of the present study was to investigate the expression of the glucose transporters GLUT1 and GLUT3 and its possible regulation by FSH, IL1 beta, and bFGF in Sertoli cells at two different time-points in sexual development. Sertoli cells retaining the ability to undergo mitosis (obtained from 8-day-old rats) and in the process of terminal differentiation (obtained from 20-day-old rats) were examined. Testicular tissue sections and Sertoli cell monolayers obtained from 8- and 20-day-old rats showed positive immunostaining for GLUT1 and GLUT3 proteins. GLUT1 and GLUT3 mRNA levels were detected at the two ages analyzed. Treatment of Sertoli cells obtained from 8- and 20-day-old rats with FSH, IL1 beta, and bFGF for various periods of time (12, 24, and 48 h) increased GLUT1 without changing GLUT3 mRNA levels. Our results thus show that Sertoli cells express GLUT1 and GLUT3 throughout pubertal development, and that, in Sertoli cells, only GLUT1 is regulated by hormones during pubertal development. Hormonal regulation of GLUT1 expression and consequently glucose uptake and lactate production may be a key molecular event in the regulation of spermatogenesis by hormones.

  10. Volume 2 - Point Sources

    EPA Pesticide Factsheets

    Point source emission reference materials from the Emissions Inventory Improvement Program (EIIP). Provides point source guidance on planning, emissions estimation, data collection, inventory documentation and reporting, and quality assurance/quality contr

  11. Comparing Point Clouds

    DTIC Science & Technology

    2004-04-01

    Point clouds are one of the most primitive and fundamental surface representations. A popular source of point clouds are three dimensional shape...acquisition devices such as laser range scanners. Another important field where point clouds are found is in the representation of high-dimensional...framework for comparing manifolds given by point clouds is presented in this paper. The underlying theory is based on Gromov-Hausdorff distances, leading

  12. Point-to-Point Multicast Communications Protocol

    NASA Technical Reports Server (NTRS)

    Byrd, Gregory T.; Nakano, Russell; Delagi, Bruce A.

    1987-01-01

    This paper describes a protocol to support point-to-point interprocessor communications with multicast. Dynamic, cut-through routing with local flow control is used to provide a high-throughput, low-latency communications path between processors. In addition multicast transmissions are available, in which copies of a packet are sent to multiple destinations using common resources as much as possible. Special packet terminators and selective buffering are introduced to avoid a deadlock during multicasts. A simulated implementation of the protocol is also described.

  13. Oil point pressure of Indian almond kernels

    NASA Astrophysics Data System (ADS)

    Aregbesola, O.; Olatunde, G.; Esuola, S.; Owolarafe, O.

    2012-07-01

    The effect of preprocessing conditions such as moisture content, heating temperature, heating time and particle size on oil point pressure of Indian almond kernel was investigated. Results showed that oil point pressure was significantly (P < 0.05) affected by above mentioned parameters. It was also observed that oil point pressure reduced with increase in heating temperature and heating time for both coarse and fine particles. Furthermore, an increase in moisture content resulted in increased oil point pressure for coarse particles while there was a reduction in oil point pressure with increase in moisture content for fine particles.

  14. Precise Time and Time Interval (PTTI) Systems and Applications Meeting (42nd Annual) Held in Reston, Virginia on November 15-18, 2010

    DTIC Science & Technology

    2010-11-01

    i 42nd Annual Precise Time and Time Interval (PTTI) Systems and Applications Meeting Proceedings of a meeting sponsored by...collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources...NATIONAL LABORATORY UPDATES Greg Weaver, Chairman Johns Hopkins University Time and Frequency Activities at the U.S. Naval Observatory

  15. Usefulness of K-Point Injection for the Nonspecific Neck Pain in So-Called K-Point Syndrome

    PubMed Central

    Moon, Jeong Jae; Ahn, Hyo Sae; Lee, Sung Jun; Lee, Dong Yeol

    2016-01-01

    Background Shoichi Kokubun introduced his successful experience with local anesthetic injection at the occipital insertion of the sternocleidomastoid muscle in K-point syndrome. The purpose of this study was to evaluate the short-term and long-term effectiveness of K-point injection and investigate factors affecting treatment results. Methods K-point injection was performed in 58 patients with K-point syndrome at Yeungnam University Medical Center. The syndrome was associated with cervical whiplash injury in 10 patients and was of nonspecific origin in the rest. One milliliter of 2% lidocaine mixed with 1 milliliter of dexamethasone was injected in 50 patients and 2 milliliters of 1% lidocaine alone in the rest. Initially, the severity of local tenderness at the K-point and other tender points was examined and the degree of immediate pain relief effect was assessed within 1 hour after injection. Early effect within 1 month after the injection and current effect were evaluated in 27 patients using a modified Kim's questionnaire with regard to the duration of improvement, degree of improvement in pain and daily living activities, and satisfaction. Results Of the total 58 patients, 44 (75.8%) apparently had immediate pain relief after K-point injection. The only factor associated with successful immediate pain relief was the whiplash injury associated with traffic accident (TA). The early pain control effect was associated with the immediate effect. The current effect was associated with the early effect alone. Satisfaction with the K-point injection was related to early successful pain relief. Conclusions K-point injection would be useful for early pain relief in nonspecific neck pain syndrome so called K-point syndrome, but not for current pain relief. Especially, it was very effective for early pain control in the whiplash injury associated with TA. PMID:27904721

  16. Ferulic Acid Administered at Various Time Points Protects against Cerebral Infarction by Activating p38 MAPK/p90RSK/CREB/Bcl-2 Anti-Apoptotic Signaling in the Subacute Phase of Cerebral Ischemia-Reperfusion Injury in Rats

    PubMed Central

    Cheng, Chin-Yi; Tang, Nou-Ying; Kao, Shung-Te; Hsieh, Ching-Liang

    2016-01-01

    Objectives This study aimed to evaluate the effects of ferulic acid (FA) administered at various time points before or after 30 min of middle cerebral artery occlusion (MCAo) followed by 7 d of reperfusion and to examine the involvement of mitogen-activated protein kinase (MAPK) signaling pathways in the cortical penumbra. Methods FA was intravenously administered to rats at a dose of 100 mg/kg 24 h before ischemia (B-FA), 2 h before ischemia (P-FA), immediately after ischemic insult (I-FA), 2 h after reperfusion (R-FA), or 24 h after reperfusion (D-FA). Results Our study results indicated that P-FA, I-FA, and R-FA effectively reduced cerebral infarct areas and neurological deficits. P-FA, I-FA, and R-FA significantly downregulated glial fibrillary acidic protein (GFAP), mitochondrial Bax, cytochrome c, and cleaved caspase-3 expression, and effectively restored the phospho-p38 MAPK (p-p38 MAPK)/p38 MAPK ratio, phospho-90 kDa ribosomal S6 kinase (p-p90RSK) expression, phospho-Bad (p-Bad) expression, the phospho-cAMP response element-binding protein (p-CREB)/CREB ratio, the cytosolic and mitochondrial Bcl-2/Bax ratios, and the cytosolic Bcl-xL/Bax ratio in the cortical penumbra 7 d after reperfusion. SB203580, a specific inhibitor of p38 MAPK, administered 30 min prior to ischemia abrogated the downregulating effects of I-FA on cerebral infarction, and mitochondrial Bax and cleaved caspase-3 expression, and the upregulating effects of I-FA on the p-p38 MAPK/p38 MAPK ratio, p-p90RSK expression, p-Bad expression, and the p-CREB/CREB, and cytosolic and mitochondrial Bcl-2/Bax ratios. Conclusions Our study results thus indicate that P-FA, I-FA, and R-FA effectively suppress reactive astrocytosis and exert neuroprotective effects against cerebral infarction by activating p38 MAPK signaling. The regulating effects of P-FA, I-FA, and R-FA on Bax-induced apoptosis result from activation of the p38 MAPK/p90RSK/CREB/Bcl-2 signaling pathway, and eventually contribute to

  17. Real-Time Tele-Mentored Low Cost “Point-of-Care US” in the Hands of Paediatricians in the Emergency Department: Diagnostic Accuracy Compared to Expert Radiologists

    PubMed Central

    Zennaro, Floriana; Neri, Elena; Nappi, Federico; Grosso, Daniele; Triunfo, Riccardo; Cabras, Francesco; Frexia, Francesca; Norbedo, Stefania; Guastalla, Pierpaolo; Gregori, Massino; Cattaruzzi, Elisabetta; Sanabor, Daniela; Barbi, Egidio; Lazzerini, Marzia

    2016-01-01

    Background The use of point-of-care ultrasonography (POC US) in paediatrics is increasing. This study investigated the diagnostic accuracy of POC US in children accessing the emergency department (ED) when performed by paediatricians under the remote guidance of radiologists (TELE POC). Methods Children aged 0 to 18 years accessing the ED of a third level research hospital with eight possible clinical scenarios and without emergency/severity signs at the triage underwent three subsequent US tests: by a paediatrician guided remotely by a radiologist (TELE POC); by the same radiologist (UNBLIND RAD); by an independent blinded radiologist (BLIND RAD). Tele-radiology was implemented using low cost “commercial off-the-shelf” (COTS) equipment and open-source software. Data were prospectively collected on predefined templates. Results Fifty-two children were enrolled, for a total of 170 ultrasound findings. Sensitivity, specificity, positive and negative predictive values of TELE POC were: 93.8, 99.7, 96.8, 99.4 when compared to UNBLIND RAD and 88.2, 99.7, 96.8, 98.7 when compared to BLIND RAD. The inter-observers agreement between the paediatricians and either the unblind or blind radiologist was excellent (k = 0.93). The mean duration of TELE POC was 6.3 minutes (95% CI 4.1 to 8.5). Technical difficulties occurred in two (3.8%) cases. Quality of the transmission was rated as fair, good, very good and excellent in 7.7%, 15.4%, 42.3% and 34.6% of cases respectively, while in no case was it rated as poor. Conclusions POC US performed by paediatricians in ED guided via tele-radiology by an expert radiologist (TELE POC) produced reliable and timely diagnoses. Findings of this study, especially for the rarer conditions under evaluation, need further confirmation. Future research should investigate the overall benefits and the cost savings of using tele-ultrasound to perform US “at children’s bedsides”, under remote guidance of expert radiologists. PMID:27749905

  18. Robust Critical Point Detection

    SciTech Connect

    Bhatia, Harsh

    2016-07-28

    Robust Critical Point Detection is a software to compute critical points in a 2D or 3D vector field robustly. The software was developed as a part of the author's work at the lab as a Phd student under Livermore Scholar Program (now called Livermore Graduate Scholar Program).

  19. Nickel Curie Point Engine

    ERIC Educational Resources Information Center

    Chiaverina, Chris; Lisensky, George

    2014-01-01

    Ferromagnetic materials such as nickel, iron, or cobalt lose the electron alignment that makes them attracted to a magnet when sufficient thermal energy is added. The temperature at which this change occurs is called the "Curie temperature," or "Curie point." Nickel has a Curie point of 627 K, so a candle flame is a sufficient…

  20. Model Breaking Points Conceptualized

    ERIC Educational Resources Information Center

    Vig, Rozy; Murray, Eileen; Star, Jon R.

    2014-01-01

    Current curriculum initiatives (e.g., National Governors Association Center for Best Practices and Council of Chief State School Officers 2010) advocate that models be used in the mathematics classroom. However, despite their apparent promise, there comes a point when models break, a point in the mathematical problem space where the model cannot,…

  1. The Lagrangian points

    NASA Astrophysics Data System (ADS)

    Linton, J. Oliver

    2017-03-01

    There are five unique points in a star/planet system where a satellite can be placed whose orbital period is equal to that of the planet. Simple methods for calculating the positions of these points, or at least justifying their existence, are developed.

  2. End Points of Sepsis Resuscitation.

    PubMed

    Greenwood, John C; Orloski, Clinton J

    2017-02-01

    Resuscitation goals for the patient with sepsis and septic shock are to return the patient to a physiologic state that promotes adequate end-organ perfusion along with matching metabolic supply and demand. Ideal resuscitation end points should assess the adequacy of tissue oxygen delivery and oxygen consumption, and be quantifiable and reproducible. Despite years of research, a single resuscitation end point to assess adequacy of resuscitation has yet to be found. Thus, the clinician must rely on multiple end points to assess the patient's overall response to therapy. This review will discuss the role and limitations of central venous pressure (CVP), mean arterial pressure (MAP), and cardiac output/index as macrocirculatory resuscitation targets along with lactate, central venous oxygen saturation (ScvO2), central venous-arterial CO2 gradient, urine output, and capillary refill time as microcirculatory resuscitation endpoints in patients with sepsis.

  3. Impact of selected troposphere models on Precise Point Positioning convergence

    NASA Astrophysics Data System (ADS)

    Kalita, Jakub; Rzepecka, Zofia

    2016-04-01

    The Precise Point Positioning (PPP) absolute method is currently intensively investigated in order to reach fast convergence time. Among various sources that influence the convergence of the PPP, the tropospheric delay is one of the most important. Numerous models of tropospheric delay are developed and applied to PPP processing. However, with rare exceptions, the quality of those models does not allow fixing the zenith path delay tropospheric parameter, leaving difference between nominal and final value to the estimation process. Here we present comparison of several PPP result sets, each of which based on different troposphere model. The respective nominal values are adopted from models: VMF1, GPT2w, MOPS and ZERO-WET. The PPP solution admitted as reference is based on the final troposphere product from the International GNSS Service (IGS). The VMF1 mapping function was used for all processing variants in order to provide capability to compare impact of applied nominal values. The worst case initiates zenith wet delay with zero value (ZERO-WET). Impact from all possible models for tropospheric nominal values should fit inside both IGS and ZERO-WET border variants. The analysis is based on data from seven IGS stations located in mid-latitude European region from year 2014. For the purpose of this study several days with the most active troposphere were selected for each of the station. All the PPP solutions were determined using gLAB open-source software, with the Kalman filter implemented independently by the authors of this work. The processing was performed on 1 hour slices of observation data. In addition to the analysis of the output processing files, the presented study contains detailed analysis of the tropospheric conditions for the selected data. The overall results show that for the height component the VMF1 model outperforms GPT2w and MOPS by 35-40% and ZERO-WET variant by 150%. In most of the cases all solutions converge to the same values during first

  4. Constructive points of powerlocales

    NASA Astrophysics Data System (ADS)

    Vickers, Steven

    1997-09-01

    Results of Bunge and Funk and of Johnstone, providing constructively sound descriptions of the global points of the lower and upper powerlocales, are extended here to describe the generalized points and proved in a way that displays in a symmetric fashion two complementary treatments of frames: as suplattices and as preframes. Also described here are the points of the Vietoris powerlocale.In each of two special cases, an exponential D ( being the Sierpinski locale) is shown to be homeomorphic to a powerlocale: to the lower powerlocale when D is discrete, and to the upper powerlocale when D is compact regular.

  5. Assessing Accuracy in Varying LIDAR Data Point Densities in Digital Elevation Maps

    DTIC Science & Technology

    2008-09-01

    burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instruction, searching ...collected by the National Geospatial Intelligence Agency in February 2008 in areas of differing ground cover amounts. 2 The following chapters will...a greater area collected (and mapped) for each pass. This becomes important when collecting against hostile targets in a military or intelligence

  6. Arctic climate tipping points.

    PubMed

    Lenton, Timothy M

    2012-02-01

    There is widespread concern that anthropogenic global warming will trigger Arctic climate tipping points. The Arctic has a long history of natural, abrupt climate changes, which together with current observations and model projections, can help us to identify which parts of the Arctic climate system might pass future tipping points. Here the climate tipping points are defined, noting that not all of them involve bifurcations leading to irreversible change. Past abrupt climate changes in the Arctic are briefly reviewed. Then, the current behaviour of a range of Arctic systems is summarised. Looking ahead, a range of potential tipping phenomena are described. This leads to a revised and expanded list of potential Arctic climate tipping elements, whose likelihood is assessed, in terms of how much warming will be required to tip them. Finally, the available responses are considered, especially the prospects for avoiding Arctic climate tipping points.

  7. Collinear Points Problem

    ERIC Educational Resources Information Center

    Shultz, Harris S.; Shiflett, Ray C.

    2008-01-01

    Students were asked to find all possible values for A so that the points (1, 2), (5, A), and (A, 7) lie on a straight line. This problem suggests a generalization: Given (x, y), find all values of A so that the points (x, y), (5, A), and (A, 7) lie on a straight line. We find that this question about linear equations must be resolved using the…

  8. Nickel Curie point engine

    NASA Astrophysics Data System (ADS)

    Chiaverina, Chris; Lisensky, George

    2014-04-01

    Ferromagnetic materials such as nickel, iron, or cobalt lose the electron alignment that makes them attracted to a magnet when sufficient thermal energy is added. The temperature at which this change occurs is called the "Curie temperature," or "Curie point." Nickel has a Curie point of 627 K, so a candle flame is a sufficient heat source. A simple but elegant device illustrates this phenomenon beautifully.

  9. Bloch points are sticky

    NASA Astrophysics Data System (ADS)

    Tchernyshyov, Oleg; Kim, Se Kwon

    2014-03-01

    Bloch points are zero-dimensional topological defects in three-dimensional ferromagnets. A representative magnetic configuration is a hedgehog with magnetization pointing away from a center. The singular nature of a Bloch point's core leads to interesting and observable consequences. A simple argument based on dimensional analysis shows that a magnetic lattice creates a periodic potential that can pin a Bloch point even if the lattice has no defects. The pinning force is of the order of the micromagnetic exchange constant, a few piconewtons in a typical ferromagnet. A domain wall in a cylindrical ferromagnetic wire with the diameter of a few tens of nanometers may contain a Bloch point. Such a domain wall will have a sizable depinning field, tens of oersteds. A Bloch point moving through an atomic lattice should emit electromagnetic waves at the frequency of a few hundred gigahertz. Research supported in part by the U.S. National Science Foundation under Grants No. DMR-0520491 and No. DMR-1104753.

  10. Reference Point Heterogeneity

    PubMed Central

    Terzi, Ayse; Koedijk, Kees; Noussair, Charles N.; Pownall, Rachel

    2016-01-01

    It is well-established that, when confronted with a decision to be taken under risk, individuals use reference payoff levels as important inputs. The purpose of this paper is to study which reference points characterize decisions in a setting in which there are several plausible reference levels of payoff. We report an experiment, in which we investigate which of four potential reference points: (1) a population average payoff level, (2) the announced expected payoff of peers in a similar decision situation, (3) a historical average level of earnings that others have received in the same task, and (4) an announced anticipated individual payoff level, best describes decisions in a decontextualized risky decision making task. We find heterogeneity among individuals in the reference points they employ. The population average payoff level is the modal reference point, followed by experimenter's stated expectation of a participant's individual earnings, followed in turn by the average earnings of other participants in previous sessions of the same experiment. A sizeable share of individuals show multiple reference points simultaneously. The reference point that best fits the choices of the individual is not affected by a shock to her income. PMID:27672374

  11. Reference Point Heterogeneity.

    PubMed

    Terzi, Ayse; Koedijk, Kees; Noussair, Charles N; Pownall, Rachel

    2016-01-01

    It is well-established that, when confronted with a decision to be taken under risk, individuals use reference payoff levels as important inputs. The purpose of this paper is to study which reference points characterize decisions in a setting in which there are several plausible reference levels of payoff. We report an experiment, in which we investigate which of four potential reference points: (1) a population average payoff level, (2) the announced expected payoff of peers in a similar decision situation, (3) a historical average level of earnings that others have received in the same task, and (4) an announced anticipated individual payoff level, best describes decisions in a decontextualized risky decision making task. We find heterogeneity among individuals in the reference points they employ. The population average payoff level is the modal reference point, followed by experimenter's stated expectation of a participant's individual earnings, followed in turn by the average earnings of other participants in previous sessions of the same experiment. A sizeable share of individuals show multiple reference points simultaneously. The reference point that best fits the choices of the individual is not affected by a shock to her income.

  12. Hyperbolic Weyl Point in Reciprocal Chiral Metamaterials

    NASA Astrophysics Data System (ADS)

    Xiao, Meng; Lin, Qian; Fan, Shanhui

    2016-07-01

    We report the existence of Weyl points in a class of noncentral symmetric metamaterials, which has time reversal symmetry, but does not have inversion symmetry due to chiral coupling between electric and magnetic fields. This class of metamaterial exhibits either type-I or type-II Weyl points depending on its nonlocal response. We also provide a physical realization of such metamaterial consisting of an array of metal wires in the shape of elliptical helices which exhibits type-II Weyl points.

  13. Critical points of metal vapors

    SciTech Connect

    Khomkin, A. L. Shumikhin, A. S.

    2015-09-15

    A new method is proposed for calculating the parameters of critical points and binodals for the vapor–liquid (insulator–metal) phase transition in vapors of metals with multielectron valence shells. The method is based on a model developed earlier for the vapors of alkali metals, atomic hydrogen, and exciton gas, proceeding from the assumption that the cohesion determining the basic characteristics of metals under normal conditions is also responsible for their properties in the vicinity of the critical point. It is proposed to calculate the cohesion of multielectron atoms using well-known scaling relations for the binding energy, which are constructed for most metals in the periodic table by processing the results of many numerical calculations. The adopted model allows the parameters of critical points and binodals for the vapor–liquid phase transition in metal vapors to be calculated using published data on the properties of metals under normal conditions. The parameters of critical points have been calculated for a large number of metals and show satisfactory agreement with experimental data for alkali metals and with available estimates for all other metals. Binodals of metals have been calculated for the first time.

  14. Change Point Detection in Correlation Networks

    PubMed Central

    Barnett, Ian; Onnela, Jukka-Pekka

    2016-01-01

    Many systems of interacting elements can be conceptualized as networks, where network nodes represent the elements and network ties represent interactions between the elements. In systems where the underlying network evolves, it is useful to determine the points in time where the network structure changes significantly as these may correspond to functional change points. We propose a method for detecting change points in correlation networks that, unlike previous change point detection methods designed for time series data, requires minimal distributional assumptions. We investigate the difficulty of change point detection near the boundaries of the time series in correlation networks and study the power of our method and competing methods through simulation. We also show the generalizable nature of the method by applying it to stock price data as well as fMRI data. PMID:26739105

  15. Infrared image mosaic using point feature operators

    NASA Astrophysics Data System (ADS)

    Huang, Zhen; Sun, Shaoyuan; Shen, Zhenyi; Hou, Junjie; Zhao, Haitao

    2016-10-01

    In this paper, we study infrared image mosaic around a single point of rotation, aiming at expanding the narrow view range of infrared images. We propose an infrared image mosaic method using point feature operators including image registration and image synthesis. Traditional mosaic algorithms usually use global image registration methods to extract the feature points in the global image, which cost too much time as well as considerable matching errors. To address this issue, we first roughly calculate the image shift amount using phase correlation and determine the overlap region between images, and then extract image features in overlap region, which shortens the registration time and increases the quality of feature points. We improve the traditional algorithm through increasing constraints of point matching based on prior knowledge of image shift amount based on which the weighted map is computed using fade in-out method. The experimental results verify that the proposed method has better real time performance and robustness.

  16. Change Point Detection in Correlation Networks

    NASA Astrophysics Data System (ADS)

    Barnett, Ian; Onnela, Jukka-Pekka

    2016-01-01

    Many systems of interacting elements can be conceptualized as networks, where network nodes represent the elements and network ties represent interactions between the elements. In systems where the underlying network evolves, it is useful to determine the points in time where the network structure changes significantly as these may correspond to functional change points. We propose a method for detecting change points in correlation networks that, unlike previous change point detection methods designed for time series data, requires minimal distributional assumptions. We investigate the difficulty of change point detection near the boundaries of the time series in correlation networks and study the power of our method and competing methods through simulation. We also show the generalizable nature of the method by applying it to stock price data as well as fMRI data.

  17. A holographic critical point

    SciTech Connect

    DeWolfe, Oliver; Rosen, Christopher; Gubser, Steven S.

    2011-04-15

    We numerically construct a family of five-dimensional black holes exhibiting a line of first-order phase transitions terminating at a critical point at finite chemical potential and temperature. These black holes are constructed so that the equation of state and baryon susceptibilities approximately match QCD lattice data at vanishing chemical potential. The critical end point in the particular model we consider has temperature 143 MeV and chemical potential 783 MeV. Critical exponents are calculated, with results that are consistent with mean-field scaling relations.

  18. SAMPEX special pointing mode

    NASA Technical Reports Server (NTRS)

    Markley, F. Landis; Flatley, Thomas W.; Leoutsakos, Theodore

    1995-01-01

    A new pointing mode has been developed for the Solar, Anomalous, and Magnetospheric Particle Explorer (SAMPEX) spacecraft. This pointing mode orients the instrument boresights perpendicular to the field lines of the Earth's magnetic field in regions of low field strength and parallel to the field lines in regions of high field strength, to allow better characterization of heavy ions trapped by the field. The new mode uses magnetometer signals and is algorithmically simpler than the previous control mode, but it requires increased momentum wheel activity. It was conceived, designed, tested, coded, uplinked to the spacecraft, and activated in less than seven months.

  19. Point and Shoot Astronomy

    NASA Astrophysics Data System (ADS)

    Hoot, John E.

    2011-05-01

    A new generation of point and shoot digital cameras, when combined with open source firmware enhancements can operate as astrographs. This paper explores the research and astro-photographic opportunities and capabilities offered by this pairing of mass production optics and open source functional extensions that retail for as little as $200.

  20. ACCESS Pointing Control System

    NASA Technical Reports Server (NTRS)

    Brugarolas, Paul; Alexander, James; Trauger, John; Moody, Dwight; Egerman, Robert; Vallone, Phillip; Elias, Jason; Hejal, Reem; Camelo, Vanessa; Bronowicki, Allen; O'Connor, David; Partrick, Richard; Orzechowski, Pawel; Spitter, Connie; Lillie, Chuck

    2010-01-01

    ACCESS (Actively-Corrected Coronograph for Exoplanet System Studies) was one of four medium-class exoplanet concepts selected for the NASA Astrophysics Strategic Mission Concept Study (ASMCS) program in 2008/2009. The ACCESS study evaluated four major coronograph concepts under a common space observatory. This paper describes the high precision pointing control system (PCS) baselined for this observatory.

  1. EcoTipping Points

    ERIC Educational Resources Information Center

    Marten, Gerald G.; Matthews, Catherine E.

    2009-01-01

    Contrary to what we often hear and teach, there is good news to be found on the environmental front. Environmental success stories show us not only that sustainability is possible, but also how people have made it happen. We can make these stories and their lessons accessible to students with help from the EcoTipping Points Project, which has…

  2. The Lagrange Points

    ERIC Educational Resources Information Center

    Lovell, M.S.

    2007-01-01

    This paper presents a derivation of all five Lagrange points by methods accessible to sixth-form students, and provides a further opportunity to match Newtonian gravity with centripetal force. The predictive powers of good scientific theories are also discussed with regard to the philosophy of science. Methods for calculating the positions of the…

  3. Decision Points in Cataloging.

    ERIC Educational Resources Information Center

    Bright, Franklyn F.

    Libraries are frequently faced with policy decisions which can affect the quality and cost of library services for years to come. This point can be illustrated by citing examples of decisions made at the University of Wisconsin Library in the areas of: (1) conforming to national cataloging standards; (2) producing catalog cards in-house; and (3)…

  4. Optical Pointing Sensor

    NASA Technical Reports Server (NTRS)

    Shields, Joel F.; Metz, Brandon C.

    2010-01-01

    The optical pointing sensor provides a means of directly measuring the relative positions of JPL s Formation Control Testbed (FCT) vehicles without communication. This innovation is a steerable infrared (IR) rangefinder that gives measurements in terms of range and bearing to a passive retroreflector.

  5. Building Temperature Set Point

    SciTech Connect

    Meincke, Carol L.; Evans, Christopher A.

    2014-09-01

    This white paper provides information and recommendations for an actionable and enforceable corporate policy statement on temperature set points for office and related spaces at Sandia and presents a strategy that balances the need to achieve the energy goals with optimizing employee comfort and productivity.

  6. Points and Practices

    ERIC Educational Resources Information Center

    Ahmed, Syed Jamil; Heddon, Dee; Mackey, Sally

    2007-01-01

    This collection of three articles represents the "Points and Practices" section of this month's issue of "Research in Drama Education." The first article, "'Fitting the Bill' for 'Helping Them.' A Response to 'Integrated Popular Theatre Approach in Africa' and 'Commissioned Theatre Projects on Human Rights in…

  7. Investigating Two Different Training Time Frames during Ramadan Fasting

    PubMed Central

    Kordi, Ramin; Abdollahi, Mohammad; Memari, Amir-Hossein; Najafabadi, Mahboubeh Ghayour

    2011-01-01

    Purpose Muslim athletes may continue training and competing while they are fasting. There is a concern about negative effects of fasting on sports performance. This study aimed to investigate the influence of two training time frames on athletes’ body composition and performance during Ramadan fasting. Methods An observational study was conducted and thirty four male volunteer athletes from different sports including volleyball, karate, taekwondo and football were assigned in two groups. The first group included 14 elite athletes who during Ramadan voluntarily participated in training sessions at 1 hour before Iftar (BI) and the second group of 20 elite athletes who during Ramadan participated in training sessions at 3 hours after Iftar (AI). Testing was performed one week before; in the first and fourth weeks of Ramadan and one week after Ramadan. Weights, heights and skinfold thickness were assessed at each time point and body mass index was calculated. Each player was assessed for agility and explosive strength as well. Results The mean weight and body mass index of both groups decreased significantly during Ramadan (P<0.001). Performance variables were not negatively affected by fasting in BI or AI group athletes. Conclusions Weight reduction might come with either BI or AI training schedules in Ramadan. Daytime or evening training did not inversely affect the agility and power performances in a group of elite athletes during Ramadan fasting. PMID:22375240

  8. Eigenspace-based tracking for feature points

    NASA Astrophysics Data System (ADS)

    Peng, Chen; Chen, Qian; Qian, Wei-xian

    2014-05-01

    Feature point tracking deals with image streams that change over time. Most existing feature point tracking algorithms only consider two adjacent frames at a time, and forget the feature information of previous frames. In this paper, we present a new eigenspace-based tracking method that learns an eigenspace representation of training features online, and finds the target feature point with Gauss-Newton style search method. A coarse-to-fine processing strategy is introduced to handle large affine transformations. Several simulations and experiments on real images indicate the effectiveness of the proposed feature tracking algorithm under the conditions of large pose changes and temporary occlusions.

  9. Quantum Change Point

    NASA Astrophysics Data System (ADS)

    Sentís, Gael; Bagan, Emilio; Calsamiglia, John; Chiribella, Giulio; Muñoz-Tapia, Ramon

    2016-10-01

    Sudden changes are ubiquitous in nature. Identifying them is crucial for a number of applications in biology, medicine, and social sciences. Here we take the problem of detecting sudden changes to the quantum domain. We consider a source that emits quantum particles in a default state, until a point where a mutation occurs that causes the source to switch to another state. The problem is then to find out where the change occurred. We determine the maximum probability of correctly identifying the change point, allowing for collective measurements on the whole sequence of particles emitted by the source. Then, we devise online strategies where the particles are measured individually and an answer is provided as soon as a new particle is received. We show that these online strategies substantially underperform the optimal quantum measurement, indicating that quantum sudden changes, although happening locally, are better detected globally.

  10. Point clouds in BIM

    NASA Astrophysics Data System (ADS)

    Antova, Gergana; Kunchev, Ivan; Mickrenska-Cherneva, Christina

    2016-10-01

    The representation of physical buildings in Building Information Models (BIM) has been a subject of research since four decades in the fields of Construction Informatics and GeoInformatics. The early digital representations of buildings mainly appeared as 3D drawings constructed by CAD software, and the 3D representation of the buildings was only geometric, while semantics and topology were out of modelling focus. On the other hand, less detailed building representations, with often focus on ‘outside’ representations were also found in form of 2D /2,5D GeoInformation models. Point clouds from 3D laser scanning data give a full and exact representation of the building geometry. The article presents different aspects and the benefits of using point clouds in BIM in the different stages of a lifecycle of a building.

  11. Quantum Change Point.

    PubMed

    Sentís, Gael; Bagan, Emilio; Calsamiglia, John; Chiribella, Giulio; Muñoz-Tapia, Ramon

    2016-10-07

    Sudden changes are ubiquitous in nature. Identifying them is crucial for a number of applications in biology, medicine, and social sciences. Here we take the problem of detecting sudden changes to the quantum domain. We consider a source that emits quantum particles in a default state, until a point where a mutation occurs that causes the source to switch to another state. The problem is then to find out where the change occurred. We determine the maximum probability of correctly identifying the change point, allowing for collective measurements on the whole sequence of particles emitted by the source. Then, we devise online strategies where the particles are measured individually and an answer is provided as soon as a new particle is received. We show that these online strategies substantially underperform the optimal quantum measurement, indicating that quantum sudden changes, although happening locally, are better detected globally.

  12. Prelinguistic Vocalizations Distinguish Pointing Acts

    ERIC Educational Resources Information Center

    Grunloh, Thomas; Liszkowski, Ulf

    2015-01-01

    The current study investigated whether point-accompanying characteristics, like vocalizations and hand shape, differentiate infants' underlying motives of prelinguistic pointing. We elicited imperative (requestive) and declarative (expressive and informative) pointing acts in experimentally controlled situations, and analyzed accompanying…

  13. Pointing control for LDR

    NASA Technical Reports Server (NTRS)

    Yam, Y.; Briggs, C.

    1988-01-01

    One important aspect of the LDR control problem is the possible excitations of structural modes due to random disturbances, mirror chopping, and slewing maneuvers. An analysis was performed to yield a first order estimate of the effects of such dynamic excitations. The analysis involved a study of slewing jitters, chopping jitters, disturbance responses, and pointing errors, making use of a simplified planar LDR model which describes the LDR dynamics on a plane perpendicular to the primary reflector. Briefly, the results indicate that the command slewing profile plays an important role in minimizing the resultant jitter, even to a level acceptable without any control action. An optimal profile should therefore be studied.

  14. Non-Gimbaled Antenna Pointing

    NASA Technical Reports Server (NTRS)

    Vigil, Jeannine S.

    1997-01-01

    The small satellite community has been interested in accessing fixed ground stations for means of space-to-ground transmissions, although a problem arises from the limited global coverage. There is a growing interest for using the Space Network (SN) or Tracking and Data Relay Satellites (TDRS) as the primary support for communications because of the coverage it provides. This thesis will address the potential for satellite access of the Space Network with a non-gimbaled antenna configuration and low-power, coded transmission. The non-gimbaled antenna and the TDRS satellites, TDRS-East, TDRS-West, and TDRS-Zone of Exclusion, were configured in an orbital analysis software package called Satellite Tool Kit to emulate the three-dimensional position of the satellites. The access potential, which is the average number of contacts per day and the average time per contact, were obtained through simulations run over a 30-day period to gain all the possible orientations. The orbital altitude was varied from 600 km through 1200 km with the results being a function of orbital inclination angles varying from 20 deg through 100 deg and pointing half-angles of I0 deg through 40 deg. To compare the validity of the simulations, Jet Propulsion Laboratory granted the use of the TOPEX satellite. The TOPEX satellite was configured to emulate a spin-stabilized antenna with its communications antenna stowed in the zenith-pointing direction. This mimicked the antenna pointing spin-stabilized satellite in the simulations. To make valid comparisons, the TOPEX orbital parameters were entered into Satellite Tool Kit and simulated over five test times provided by Jet Propulsion Laboratory.

  15. Best-practices approach to determination of blood alcohol concentration (BAC) at specific time points: Combination of ante-mortem alcohol pharmacokinetic modeling and post-mortem alcohol generation and transport considerations.

    PubMed

    Cowan, Dallas M; Maskrey, Joshua R; Fung, Ernest S; Woods, Tyler A; Stabryla, Lisa M; Scott, Paul K; Finley, Brent L

    2016-07-01

    Alcohol concentrations in biological matrices offer information regarding an individual's intoxication level at a given time. In forensic cases, the alcohol concentration in the blood (BAC) at the time of death is sometimes used interchangeably with the BAC measured post-mortem, without consideration for alcohol concentration changes in the body after death. However, post-mortem factors must be taken into account for accurate forensic determination of BAC prior to death to avoid incorrect conclusions. The main objective of this work was to describe best practices for relating ante-mortem and post-mortem alcohol concentrations, using a combination of modeling, empirical data and other qualitative considerations. The Widmark modeling approach is a best practices method for superimposing multiple alcohol doses ingested at various times with alcohol elimination rate adjustments based on individual body factors. We combined the selected ante-mortem model with a suggestion for an approach used to roughly estimate changes in BAC post-mortem, and then analyzed the available data on post-mortem alcohol production in human bodies and potential markers for alcohol production through decomposition and putrefaction. Hypothetical cases provide best practice approaches as an example for determining alcohol concentration in biological matrices ante-mortem, as well as potential issues encountered with quantitative post-mortem approaches. This study provides information for standardizing BAC determination in forensic toxicology, while minimizing real world case uncertainties.

  16. Stress-Induced Accumulation of DcAOX1 and DcAOX2a Transcripts Coincides with Critical Time Point for Structural Biomass Prediction in Carrot Primary Cultures (Daucus carota L.)

    PubMed Central

    Campos, M. Doroteia; Nogales, Amaia; Cardoso, Hélia G.; Kumar, Sarma R.; Nobre, Tânia; Sathishkumar, Ramalingam; Arnholdt-Schmitt, Birgit

    2016-01-01

    Stress-adaptive cell plasticity in target tissues and cells for plant biomass growth is important for yield stability. In vitro systems with reproducible cell plasticity can help to identify relevant metabolic and molecular events during early cell reprogramming. In carrot, regulation of the central root meristem is a critical target for yield-determining secondary growth. Calorespirometry, a tool previously identified as promising for predictive growth phenotyping has been applied to measure the respiration rate in carrot meristem. In a carrot primary culture system (PCS), this tool allowed identifying an early peak related with structural biomass formation during lag phase of growth, around the 4th day of culture. In the present study, we report a dynamic and correlated expression of carrot AOX genes (DcAOX1 and DcAOX2a) during PCS lag phase and during exponential growth. Both genes showed an increase in transcript levels until 36 h after explant inoculation, and a subsequent down-regulation, before the initiation of exponential growth. In PCS growing at two different temperatures (21°C and 28°C), DcAOX1 was also found to be more expressed in the highest temperature. DcAOX genes’ were further explored in a plant pot experiment in response to chilling, which confirmed the early AOX transcript increase prior to the induction of a specific anti-freezing gene. Our findings point to DcAOX1 and DcAOX2a as being reasonable candidates for functional marker development related to early cell reprogramming. While the genomic sequence of DcAOX2a was previously described, we characterize here the complete genomic sequence of DcAOX1. PMID:26858746

  17. Short-Term Thermal-Humidity Shock Affects Point-of-Care Glucose Testing: Implications for Health Professionals and Patients.

    PubMed

    Lam, Mandy; Louie, Richard F; Curtis, Corbin M; Ferguson, William J; Vy, John H; Truong, Anh-Thu; Sumner, Stephanie L; Kost, Gerald J

    2014-01-01

    The objective was to assess the effects of short-term (≤1 hour) static high temperature and humidity stresses on the performance of point-of-care (POC) glucose test strips and meters. Glucose meters are used by medical responders and patients in a variety of settings including hospitals, clinics, homes, and the field. Reagent test strips and instruments are potentially exposed to austere environmental conditions. Glucose test strips and meters were exposed to a mean relative humidity of 83.0% (SD = 8.0%) and temperature of 42°C (107.6°F, SD = 3.2) in a Tenney BTRC environmental chamber. Stressed and unstressed glucose reagent strips and meters were tested with spiked blood samples (n = 40 measurements per time point for each of 4 trials) after 15, 30, 45, and 60 minutes of exposure. Wilcoxon's signed rank test was applied to compare measurements test strip and meter measurements to isolate and characterize the magnitude of meter versus test strip effects individually. Stressed POC meters and test strips produced elevated glucose results, with stressed meter bias as high as 20 mg/dL (17.7% error), and stressed test strip bias as high as 13 mg/dL (12.2% error). The aggregate stress effect on meter and test strips yielded a positive bias as high as 33 mg/dL (30.1% error) after 15 minutes of exposure. Short-term exposure (15 minutes) to high temperature and humidity can significantly affect the performance of POC glucose test strips and meters, with measurement biases that potentially affect clinical decision making and patient safety.

  18. Instrument Pointing Capabilities: Past, Present, and Future

    NASA Technical Reports Server (NTRS)

    Blackmore, Lars; Murray, Emmanuell; Scharf, Daniel P.; Aung, Mimi; Bayard, David; Brugarolas, Paul; Hadaegh, Fred; Lee, Allan; Milman, Mark; Sirlin, Sam; Kang, Bryan

    2011-01-01

    This paper surveys the instrument pointing capabilities of past, present and future space telescopes and interferometers. As an important aspect of this survey, we present a taxonomy for "apples-to-apples" comparisons of pointing performances. First, pointing errors are defined relative to either an inertial frame or a celestial target. Pointing error can then be further sub-divided into DC, that is, steady state, and AC components. We refer to the magnitude of the DC error relative to the inertial frame as absolute pointing accuracy, and we refer to the magnitude of the DC error relative to a celestial target as relative pointing accuracy. The magnitude of the AC error is referred to as pointing stability. While an AC/DC partition is not new, we leverage previous work by some of the authors to quantitatively clarify and compare varying definitions of jitter and time window averages. With this taxonomy and for sixteen past, present, and future missions, pointing accuracies and stabilities, both required and achieved, are presented. In addition, we describe the attitude control technologies used to and, for future missions, planned to achieve these pointing performances.

  19. Relative Critical Points

    NASA Astrophysics Data System (ADS)

    Lewis, Debra

    2013-05-01

    Relative equilibria of Lagrangian and Hamiltonian systems with symmetry are critical points of appropriate scalar functions parametrized by the Lie algebra (or its dual) of the symmetry group. Setting aside the structures - symplectic, Poisson, or variational - generating dynamical systems from such functions highlights the common features of their construction and analysis, and supports the construction of analogous functions in non-Hamiltonian settings. If the symmetry group is nonabelian, the functions are invariant only with respect to the isotropy subgroup of the given parameter value. Replacing the parametrized family of functions with a single function on the product manifold and extending the action using the (co)adjoint action on the algebra or its dual yields a fully invariant function. An invariant map can be used to reverse the usual perspective: rather than selecting a parametrized family of functions and finding their critical points, conditions under which functions will be critical on specific orbits, typically distinguished by isotropy class, can be derived. This strategy is illustrated using several well-known mechanical systems - the Lagrange top, the double spherical pendulum, the free rigid body, and the Riemann ellipsoids - and generalizations of these systems.

  20. HORSESHOE CURVE IN GLACIER POINT ROAD NEAR GLACIER POINT. HALF ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    HORSESHOE CURVE IN GLACIER POINT ROAD NEAR GLACIER POINT. HALF DOME AT CENTER REAR. SAME VIEW AT CA-157-2. LOOKING NNE. GIS: N-37' 43 44.3 / W-119 34 14.1 - Glacier Point Road, Between Chinquapin Flat & Glacier Point, Yosemite Village, Mariposa County, CA

  1. 2. HORSESHOE CURVE IN GLACIER POINT ROAD NEAR GLACIER POINT. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. HORSESHOE CURVE IN GLACIER POINT ROAD NEAR GLACIER POINT. HALF DOME AT CENTER REAR. LOOKING NNE. GIS N-37 43 44.3 / W-119 34 14.1 - Glacier Point Road, Between Chinquapin Flat & Glacier Point, Yosemite Village, Mariposa County, CA

  2. 47 CFR 80.41 - Control points and dispatch points.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Control points and dispatch points. 80.41... SERVICES STATIONS IN THE MARITIME SERVICES Applications and Licenses § 80.41 Control points and dispatch... dispatch points may be installed and used without obtaining any authorization from the Commission....

  3. 47 CFR 80.41 - Control points and dispatch points.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 5 2011-10-01 2011-10-01 false Control points and dispatch points. 80.41... SERVICES STATIONS IN THE MARITIME SERVICES Applications and Licenses § 80.41 Control points and dispatch... dispatch points may be installed and used without obtaining any authorization from the Commission....

  4. 47 CFR 80.41 - Control points and dispatch points.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 5 2013-10-01 2013-10-01 false Control points and dispatch points. 80.41... SERVICES STATIONS IN THE MARITIME SERVICES Applications and Licenses § 80.41 Control points and dispatch... dispatch points may be installed and used without obtaining any authorization from the Commission....

  5. 47 CFR 80.41 - Control points and dispatch points.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 5 2014-10-01 2014-10-01 false Control points and dispatch points. 80.41... SERVICES STATIONS IN THE MARITIME SERVICES Applications and Licenses § 80.41 Control points and dispatch... dispatch points may be installed and used without obtaining any authorization from the Commission....

  6. 47 CFR 80.41 - Control points and dispatch points.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 5 2012-10-01 2012-10-01 false Control points and dispatch points. 80.41... SERVICES STATIONS IN THE MARITIME SERVICES Applications and Licenses § 80.41 Control points and dispatch... dispatch points may be installed and used without obtaining any authorization from the Commission....

  7. A three-point time series study of antibiotic usage on an intensive care unit, following an antibiotic stewardship programme, after an outbreak of multi-resistant Acinetobacter baumannii.

    PubMed

    Singh, S; Zhang, Y Z; Chalkley, S; Ananthan, K; Demertzi, E; Beach, M; Cohen, M; Grover, V; Chung, C; Tatlock, J; Soni, N; Azadian, B

    2015-09-01

    Antibiotic use in intensive care units (ICUs) can promote antimicrobial resistance. Outbreaks of multi-resistant bacteria significantly affect patient outcomes and delivery of care. Antibiotic stewardship programmes (ASPs), combining root-cause analyses and multi-faceted prevention strategies, are necessary, often at significant cost and time. Which elements of such strategies have the largest impact on antibiotic usage following an outbreak is unclear. The aim of this study was to investigate how antibiotic usage in a university hospital ICU changed with a non-protocolised ASP following a disruptive outbreak of multi-resistant Acinetobacter baumannii (MRAB). This was a three time-period observational cohort study. The primary endpoint was the change in overall antibiotic usage (daily defined dose, DDD, antibiotic-days, antibiotic-courses) for consecutive ICU patients staying >48 h, over three 6-month study time periods pre-MRAB (2008, n = 84) and post-MRAB (2010, n = 88; 2012, n = 122). Secondary endpoints were changes in antibiotic usage and patient demographics, in predefined admission categories (Medical Emergency, ME; Surgical Elective, SEL; and Surgical Emergency, SE). The mean age (54.6 ± 17.7, 58.1 ± 17.9, 62.8 ± 19.1 years*) and severity of illness (APACHE 14.8 ± 8.0, 16.7 ± 6.8, 18.3 ± 6.1*) increased, particularly medical admissions. There was a sustained reduction in DDD antibiotic usage [1895.1 (2008), 1224.2 (2010), 1236.6 (2012) per 1000 patient-days] but no overall change in antibiotic-days or antibiotic-courses. Antibiotic usage (antibiotic-days) fell significantly in surgical emergency admissions [20.2 ± 32.1, 4.6 ± 7.4*, 5.9 ± 7.3]. There was a sustained drop in beta-lactam, quinolone, glycopeptide and macrolide usage. Following an MRAB outbreak, and subsequent operational changes including enhanced ASPs (non-protocolised), there was a sustained overall fall in antibiotic usage in spite of

  8. Improvements in floating point addition/subtraction operations

    DOEpatents

    Farmwald, P.M.

    1984-02-24

    Apparatus is described for decreasing the latency time associated with floating point addition and subtraction in a computer, using a novel bifurcated, pre-normalization/post-normalization approach that distinguishes between differences of floating point exponents.

  9. Extended Kalman filtering of point process observation.

    PubMed

    Salimpour, Yousef; Soltanian-Zadeh, Hamid; Abolhassani, Mohammad D

    2010-01-01

    A temporal point process is a stochastic time series of binary events that occurs in continuous time. In computational neuroscience, the point process is used to model neuronal spiking activity; however, estimating the model parameters from spike train is a challenging problem. The state space point process filtering theory is a new technique for the estimation of the states and parameters. In order to use the stochastic filtering theory for the states of neuronal system with the Gaussian assumption, we apply the extended Kalman filter. In this regard, the extended Kalman filtering equations are derived for the point process observation. We illustrate the new filtering algorithm by estimating the effect of visual stimulus on the spiking activity of object selective neurons from the inferior temporal cortex of macaque monkey. Based on the goodness-offit assessment, the extended Kalman filter provides more accurate state estimate than the conventional methods.

  10. Statistical aspects of point count sampling

    USGS Publications Warehouse

    Barker, R.J.; Sauer, J.R.; Ralph, C.J.; Sauer, J.R.; Droege, S.

    1995-01-01

    The dominant feature of point counts is that they do not census birds, but instead provide incomplete counts of individuals present within a survey plot. Considering a simple model for point count sampling, we demon-strate that use of these incomplete counts can bias estimators and testing procedures, leading to inappropriate conclusions. A large portion of the variability in point counts is caused by the incomplete counting, and this within-count variation can be confounded with ecologically meaningful varia-tion. We recommend caution in the analysis of estimates obtained from point counts. Using; our model, we also consider optimal allocation of sampling effort. The critical step in the optimization process is in determining the goals of the study and methods that will be used to meet these goals. By explicitly defining the constraints on sampling and by estimating the relationship between precision and bias of estimators and time spent counting, we can predict the optimal time at a point for each of several monitoring goals. In general, time spent at a point will differ depending on the goals of the study.

  11. Time Resolved Measurements and Reactive Pathways of Hypergolic Bipropellant Combustion

    DTIC Science & Technology

    2006-03-31

    estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the...0704-0188,) Washington, DC 20503. 1 . AGENCY USE ONLY ( Leave Blank) 2. REPORT DATE 3. REPORT TYPE AND DATES COVERED 4. TITLE AND SUBTITLE 5...Standard Form 298 (Rev.2-89) Prescribed by ANSI Std. 239-18 298-102 Enclosure 1 03/31/06 Final Report 01 Aug 02 - 31 Dec 05 TIME RESOLVED

  12. Discovering new points of differentiation.

    PubMed

    MacMillan, I C; McGrath, R G

    1997-01-01

    Most profitable strategies are built on differentiation: offering customers something they value that competitors don't have. But most companies concentrate only on their products or services. In fact, a company can differentiate itself every point where it comes in contact with its customers--from the moment customers realize they need a product or service to the time when they dispose of it. The authors believe that if companies open up their thinking to their customer's entire experience with a product or service--the consumption chain--they can uncover opportunities to position their offerings in ways that neither they nor their competitors though possible. The authors show how even a mundane product such as candles can be successfully differentiated. By analyzing its customers' experiences and exploring various options, Blyth Industries, for example, has grown from a $2 million U.S. candle manufacturer into a global candle and accessory business with nearly $500 million in sales and a market value of $1.2 billion. Finding ways to differentiate one's company is a skill that can be nurtured, the authors contend. In this Manager's Tool Kit, they have designed a two-part approach that can help companies continually identify new points of differentiation and develop the ability to generate successful differentiation strategies. "Mapping the Consumption Chain" captures the customer's total experience with a product or service. "Analyzing Your Customer's Experience" shows managers how directed brainstorming about each step in the consumption chain can elicit numerous ways to differentiate any offering.

  13. Function Point Analysis Depot

    NASA Technical Reports Server (NTRS)

    Muniz, R.; Martinez, El; Szafran, J.; Dalton, A.

    2011-01-01

    The Function Point Analysis (FPA) Depot is a web application originally designed by one of the NE-C3 branch's engineers, Jamie Szafran, and created specifically for the Software Development team of the Launch Control Systems (LCS) project. The application consists of evaluating the work of each developer to be able to get a real estimate of the hours that is going to be assigned to a specific task of development. The Architect Team had made design change requests for the depot to change the schema of the application's information; that information, changed in the database, needed to be changed in the graphical user interface (GUI) (written in Ruby on Rails (RoR and the web service/server side in Java to match the database changes. These changes were made by two interns from NE-C, Ricardo Muniz from NE-C3, who made all the schema changes for the GUI in RoR and Edwin Martinez, from NE-C2, who made all the changes in the Java side.

  14. Pointing at 'Puffin'

    NASA Technical Reports Server (NTRS)

    2004-01-01

    [figure removed for brevity, see original site] [figure removed for brevity, see original site] Figure 1Figure 2

    The intriguing dunes at the bottom of 'Endurance Crater' presented a tantalizing target for the science team for NASA's Mars Exploration Rover Opportunity. After analyzing the soil near and around the dunes, however, the rover engineering team decided that it was too risky to send Opportunity any closer. The terrain between the rover and the dune tendril did not present clear evidence of rocky plates to give the rover sufficient traction. A finger-like dune tendril pictured here (left) is, essentially, pointing to the rover's current area of investigation. Opportunity rolled over the foreground rock, called 'Puffin.' During the past several sols the rover has been examining its new neighborhood, an area that includes the rocks 'Ellesmere' and 'Escher' (not pictured) and the soil targets 'Shag' and 'Auk' (also not pictured). Experiencing significant slippage, the rover did some unintended trenching and left deep tracks in this area. This view is a mosaic of two images taken by the rover's navigation camera on Opportunity's 206th sol on Mars (August 22, 2004) and presented in a perspective projection. Figure 1 is a cylindrical-perspective projection and Figure 2 is a cylindrical perspective.

  15. Chiral exceptional points in metasurfaces

    NASA Astrophysics Data System (ADS)

    Kang, Ming; Chen, Jing; Chong, Y. D.

    2016-09-01

    An exceptional point (EP) is a degeneracy occurring in a non-energy-conserving system, in which two eigenvectors of a non-Hermitian Hamiltonian coalesce. We explore how EPs can be realized in a metamaterial surface, or metasurface, consisting of a pair of lossy coupled linear antennas in each unit cell. EPs appear in the eigenvectors of the transmission matrix by tuning the frequency and the coupling and loss rates of the metasurface. Each EP is associated with the appearance of a circularly polarized transmission eigenstate; hence, within the parameter space of the system, the EPs lie along pairs of curves with distinct chirality. Our results are obtained using finite-difference time-domain simulations, as well as a fitted coupled-mode theory. The coupled-mode theory agrees well with the numerical results and is capable of accurately predicting the EP f curves.

  16. Hidden isosbestic point(s) in ultraviolet spectra.

    PubMed

    Pouët, M-F; Baures, E; Vaillant, S; Thomas, O

    2004-04-01

    The existence of isosbestic point(s) in a set of UV-visible spectra is rarely exploited for quantitative or qualitative information despite its interest. Indeed, the presence of isosbestic points means a quality and quantity conservation in the global composition of samples with a given relation between the concentration of absorbing compounds or mixtures of compounds. However, in some cases, for example, when a dilution occurs, no isosbestic point appears. This work shows that a simple operation, called normalization, can reveal the existence of hidden isosbestic point(s) (IP*). This paper first summarizes the required conditions for the presence of isosbestic points. Second, it demonstrates the significance of IP* revealed by normalization. An example of the exploitation of direct or hidden isosbestic points in the environmental field illustrates the interest in and application of the technique.

  17. Change point detection of the Persian Gulf sea surface temperature

    NASA Astrophysics Data System (ADS)

    Shirvani, A.

    2017-01-01

    In this study, the Student's t parametric and Mann-Whitney nonparametric change point models (CPMs) were applied to detect change point in the annual Persian Gulf sea surface temperature anomalies (PGSSTA) time series for the period 1951-2013. The PGSSTA time series, which were serially correlated, were transformed to produce an uncorrelated pre-whitened time series. The pre-whitened PGSSTA time series were utilized as the input file of change point models. Both the applied parametric and nonparametric CPMs estimated the change point in the PGSSTA in 1992. The PGSSTA follow the normal distribution up to 1992 and thereafter, but with a different mean value after year 1992. The estimated slope of linear trend in PGSSTA time series for the period 1951-1992 was negative; however, that was positive after the detected change point. Unlike the PGSSTA, the applied CPMs suggested no change point in the Niño3.4SSTA time series.

  18. Role of Erosion in Shaping Point Bars

    NASA Astrophysics Data System (ADS)

    Moody, J.; Meade, R.

    2012-04-01

    A powerful metaphor in fluvial geomorphology has been that depositional features such as point bars (and other floodplain features) constitute the river's historical memory in the form of uniformly thick sedimentary deposits waiting for the geomorphologist to dissect and interpret the past. For the past three decades, along the channel of Powder River (Montana USA) we have documented (with annual cross-sectional surveys and pit trenches) the evolution of the shape of three point bars that were created when an extreme flood in 1978 cut new channels across the necks of two former meander bends and radically shifted the location of a third bend. Subsequent erosion has substantially reshaped, at different time scales, the relic sediment deposits of varying age. At the weekly to monthly time scale (i.e., floods from snowmelt or floods from convective or cyclonic storms), the maximum scour depth was computed (by using a numerical model) at locations spaced 1 m apart across the entire point bar for a couple of the largest floods. The maximum predicted scour is about 0.22 m. At the annual time scale, repeated cross-section topographic surveys (25 during 32 years) indicate that net annual erosion at a single location can be as great as 0.5 m, and that the net erosion is greater than net deposition during 8, 16, and 32% of the years for the three point bars. On average, the median annual net erosion was 21, 36, and 51% of the net deposition. At the decadal time scale, an index of point bar preservation often referred to as completeness was defined for each cross section as the percentage of the initial deposit (older than 10 years) that was still remaining in 2011; computations indicate that 19, 41, and 36% of the initial deposits of sediment were eroded. Initial deposits were not uniform in thickness and often represented thicker pods of sediment connected by thin layers of sediment or even isolated pods at different elevations across the point bar in response to multiple

  19. What's the Point? The Benefits of Grading without Points

    ERIC Educational Resources Information Center

    Brilleslyper, Mike; Ghrist, Michelle; Holcomb, Trae; Schaubroeck, Beth; Warner, Bradley; Williams, Scott

    2012-01-01

    Most instructors desire to create a learning environment conducive to deep learning. However, in courses where grades are based upon the accumulation of points, students may focus on collecting points rather than on learning and achieving the course objectives. We discuss an alternative points-free course design based on the development of clear…

  20. Perpetual points and periodic perpetual loci in maps

    NASA Astrophysics Data System (ADS)

    Dudkowski, Dawid; Prasad, Awadhesh; Kapitaniak, Tomasz

    2016-10-01

    We introduce the concepts of perpetual points and periodic perpetual loci in discrete-time systems (maps). The occurrence and analysis of these points/loci are shown and basic examples are considered. We discuss the potential usage and properties of the introduced concepts. The comparison of perpetual points and loci in discrete-time and continuous-time systems is presented. The discussed methods can be widely applied in other dynamical systems.

  1. Perpetual points and periodic perpetual loci in maps.

    PubMed

    Dudkowski, Dawid; Prasad, Awadhesh; Kapitaniak, Tomasz

    2016-10-01

    We introduce the concepts of perpetual points and periodic perpetual loci in discrete-time systems (maps). The occurrence and analysis of these points/loci are shown and basic examples are considered. We discuss the potential usage and properties of the introduced concepts. The comparison of perpetual points and loci in discrete-time and continuous-time systems is presented. The discussed methods can be widely applied in other dynamical systems.

  2. Using Covariance Analysis to Assess Pointing Performance

    NASA Technical Reports Server (NTRS)

    Bayard, David; Kang, Bryan

    2009-01-01

    A Pointing Covariance Analysis Tool (PCAT) has been developed for evaluating the expected performance of the pointing control system for NASA s Space Interferometry Mission (SIM). The SIM pointing control system is very complex, consisting of multiple feedback and feedforward loops, and operating with multiple latencies and data rates. The SIM pointing problem is particularly challenging due to the effects of thermomechanical drifts in concert with the long camera exposures needed to image dim stars. Other pointing error sources include sensor noises, mechanical vibrations, and errors in the feedforward signals. PCAT models the effects of finite camera exposures and all other error sources using linear system elements. This allows the pointing analysis to be performed using linear covariance analysis. PCAT propagates the error covariance using a Lyapunov equation associated with time-varying discrete and continuous-time system matrices. Unlike Monte Carlo analysis, which could involve thousands of computational runs for a single assessment, the PCAT analysis performs the same assessment in a single run. This capability facilitates the analysis of parametric studies, design trades, and "what-if" scenarios for quickly evaluating and optimizing the control system architecture and design.

  3. The power of PowerPoint.

    PubMed

    Niamtu, J

    2001-08-01

    Carousel slide presentations have been used for academic and clinical presentations since the late 1950s. However, advances in computer technology have caused a paradigm shift, and digital presentations are quickly becoming standard for clinical presentations. The advantages of digital presentations include cost savings; portability; easy updating capability; Internet access; multimedia functions, such as animation, pictures, video, and sound; and customization to augment audience interest and attention. Microsoft PowerPoint has emerged as the most popular digital presentation software and is currently used by many practitioners with and without significant computer expertise. The user-friendly platform of PowerPoint enables even the novice presenter to incorporate digital presentations into his or her profession. PowerPoint offers many advanced options that, with a minimal investment of time, can be used to create more interactive and professional presentations for lectures, patient education, and marketing. Examples of advanced PowerPoint applications are presented in a stepwise manner to unveil the full power of PowerPoint. By incorporating these techniques, medical practitioners can easily personalize, customize, and enhance their PowerPoint presentations. Complications, pitfalls, and caveats are discussed to detour and prevent misadventures in digital presentations. Relevant Web sites are listed to further update, customize, and communicate PowerPoint techniques.

  4. On Pfaffian Random Point Fields

    NASA Astrophysics Data System (ADS)

    Kargin, V.

    2014-02-01

    We study Pfaffian random point fields by using the Moore-Dyson quaternion determinants. First, we give sufficient conditions that ensure that a self-dual quaternion kernel defines a valid random point field, and then we prove a CLT for Pfaffian point fields. The proofs are based on a new quaternion extension of the Cauchy-Binet determinantal identity. In addition, we derive the Fredholm determinantal formulas for the Pfaffian point fields which use the quaternion determinant.

  5. Control of precision pointing system

    NASA Astrophysics Data System (ADS)

    Gu, Zheng

    Distributed-parameter modeling of tube with moving mass using Magnetic Compressional Damping Treatment (MCDT) is developed. Hamilton's principle is utilized to develop the model and boundary condition of a tube with moving mass using MCDT. Based on the electromagnetic theory, the relation between the generated magnet force of the actuator (MCDT) and the control current is determined. A stable control strategy is developed to damp out the vibration of the tube with moving mass using MCDT system. The fundamental characteristics of an active and a passive version of the Magnetic Compressional Damping Treatment (MCDT) are investigated by the finite element method. The damping characteristics of tube/MCDT system are modeled by Golla-Hughes-McTavish (GHM) method in order to predict the tube response in the time domain. The numerical results are verified through experimentation using a cantilevered tube treated with MCDT at the free end. The tube vibration due to an internally moving load is controlled by the MCDT using a deflection feedback controller. Close agreement is obtained between theory and experiments. The effectiveness of the MCDT in attenuating structural vibration of the tube has also been clearly demonstrated in the time and frequency domains. The developed theoretical and experimental techniques present invaluable tools for designing and predicting the performance of precision pointing tubes different damping treatments when subjected to moving loads.

  6. Multipoint-to-Point and Point-to-Multipoint Space-Time Network Coding

    DTIC Science & Technology

    2010-03-01

    on July 06,2010 at 13:53:22 UTC from IEEE Xplore . Restrictions apply. Report Documentation Page Form ApprovedOMB No. 0704-0188 Public reporting...Authorized licensed use limited to: University of Maryland College Park. Downloaded on July 06,2010 at 13:53:22 UTC from IEEE Xplore . Restrictions apply...University of Maryland College Park. Downloaded on July 06,2010 at 13:53:22 UTC from IEEE Xplore . Restrictions apply. 0 5 10 15 20 25 30 10 −6 10 −5 10

  7. Turning Points: Priorities for Teacher Education in a Democracy

    ERIC Educational Resources Information Center

    Romano, Rosalie M.

    2009-01-01

    Every generation has its moment, some turning point that will mark its place in the historical record. Such points provide the direction of our history and our future. Turning points are, characteristically, times of turmoil based on a fundamental change in models or events--what Thomas Kuhn called a "paradigm shift." In terms of a democratic…

  8. The Herschel Point Source Catalogue

    NASA Astrophysics Data System (ADS)

    Marton, Gabor; Schulz, Bernhard; Altieri, Bruno; Calzoletti, Luca; Kiss, Csaba; Lim, Tanya; Lu, Nanyao; Paladini, Roberta; Papageorgiou, Andreas; Pearson, Chris; Rector, John; Shupe, David; Valtchanov, Ivan; Verebélyi, Erika; Xu, Kevin

    2015-08-01

    The Herschel Space Observatory was the fourth cornerstone mission in the European Space Agency (ESA) science programme with excellent broad band imaging capabilities in the submillimetre and far-infrared part of the spectrum. Although the spacecraft finished its observations in 2013, it left a large legacy dataset that is far from having been fully scrutinized and still has potential for new scientific discoveries. This is specifically true for the photometric observations of the PACS and SPIRE instruments that scanned >10% of the sky at 70, 100, 160, 250, 350 and 500 microns. Some source catalogs have already been produced by individual observing programs, but there are many observations that would never be analyzed for their full source content. To maximize the science return of the SPIRE and PACS data sets, our international team of instrument experts is in the process of building the Herschel Point Source Catalog (HPSC) from all scan map observations. Our homogeneous source extraction enables a systematic and unbiased comparison of sensitivity across the different Herschel fields that single programs will generally not be able to provide. The extracted point sources will contain individual YSOs of our Galaxy, unresolved YSO clusters in resolved nearby galaxies and unresolved galaxies of the local and distant Universe that are related to star formation. Such a huge dataset will help scientists better understand the evolution from interstellar clouds to individual stars. Furthermore the analysis of stellar clusters and the star formation on galactic scales will add more details to the understanding of star formation laws through time.We present our findings on comparison of different source detection and photometric tools. First results of the extractions are shown along with the description of our pipelines and catalogue entries. We also provide an additional science product, the structure noise map, that is used for the quality assessment of the catalogue in

  9. Timing Tricks For Complicated Accelerators [PowerPoint

    SciTech Connect

    Bjorklund, Eric A.

    2015-11-02

    A brief description of the Los Alamos Neutron Science Center is given first, including static and dynamic scheduling. The principal tricks presented are prescient feed forward and pulser replication. Tricks with flip/flop pulsers are also included.

  10. 22 CFR 161.5 - Major decision points and timing.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... regulations at the earliest practicable stage of Departmental study, consideration or planning of a proposed... variety of circumstances. Bearing in mind the degree to which other countries possess information on...

  11. 22 CFR 161.5 - Major decision points and timing.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... regulations at the earliest practicable stage of Departmental study, consideration or planning of a proposed... variety of circumstances. Bearing in mind the degree to which other countries possess information on...

  12. 22 CFR 161.5 - Major decision points and timing.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... regulations at the earliest practicable stage of Departmental study, consideration or planning of a proposed... variety of circumstances. Bearing in mind the degree to which other countries possess information on...

  13. 22 CFR 161.5 - Major decision points and timing.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... regulations at the earliest practicable stage of Departmental study, consideration or planning of a proposed... variety of circumstances. Bearing in mind the degree to which other countries possess information on...

  14. 22 CFR 161.5 - Major decision points and timing.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... regulations at the earliest practicable stage of Departmental study, consideration or planning of a proposed... variety of circumstances. Bearing in mind the degree to which other countries possess information on...

  15. JMCC Point-Counterpoint

    PubMed Central

    Lakatta, Edward G.; DiFrancesco, Dario

    2015-01-01

    Prologue The processes underlying the initiation of the heartbeat, whether due to intracellular metabolism or surface membrane events, have always been a major focus of cardiac research. About 50 years ago, pioneering work initiated by Silvio Weidmann and others applied the Hodgkin-Huxley formalism of membrane excitation to interpret the cardiac electrical activity, including the pacemaker depolarization (see D. Noble, 1979 The initiation of the heartbeat, Clarendon Press). The underlying idea was that voltage- and time-dependent gating of various surface membrane channels not only generated the cardiac pacemaker action potential (AP), but also controlled the spontaneous depolarization between AP’s and thus determined when the next AP would occur. According to this description, the ensemble of surface membrane ion channels works as a clock that regulates the rate and rhythm of spontaneous AP firing, otherwise known as normal automaticity. A formidable research effort then concentrated in attempting to target which of the surface membrane ion channels had an important role in controlling the spontaneous diastolic depolarization (DD). Originally, a major role was attributed to the “IK-decay theory”. This was strongly influenced by the previous Hodgkin-Huxley model of nerve AP, which described the slow depolarization following a nerve AP as due to the decay of a K+ current. This model of pacemaker depolarization lasted some 20 years, until it was turned upside-down by a full re-interpretation based on the discovery of the If current. Other ionic currents gated by membrane depolarization, i.e. ICaL, ICaT, IST, non-gated and non-specific background leak currents, and also a current generated by the Na-Ca exchange (NCX) carrier, were also proposed to be involved in pacemaking. Based on a wealth of experimental evidence, If is today considered as the most important ion channel involved in the rate regulation of cardiac pacemaker cells, and is sometimes referred to

  16. Ground point filtering of UAV-based photogrammetric point clouds

    NASA Astrophysics Data System (ADS)

    Anders, Niels; Seijmonsbergen, Arie; Masselink, Rens; Keesstra, Saskia

    2016-04-01

    Unmanned Aerial Vehicles (UAVs) have proved invaluable for generating high-resolution and multi-temporal imagery. Based on photographic surveys, 3D surface reconstructions can be derived photogrammetrically so producing point clouds, orthophotos and surface models. For geomorphological or ecological applications it may be necessary to separate ground points from vegetation points. Existing filtering methods are designed for point clouds derived using other methods, e.g. laser scanning. The purpose of this paper is to test three filtering algorithms for the extraction of ground points from point clouds derived from low-altitude aerial photography. Three subareas were selected from a single flight which represent different scenarios: 1) low relief, sparsely vegetated area, 2) low relief, moderately vegetated area, 3) medium relief and moderately vegetated area. The three filtering methods are used to classify ground points in different ways, based on 1) RGB color values from training samples, 2) TIN densification as implemented in LAStools, and 3) an iterative surface lowering algorithm. Ground points are then interpolated into a digital terrain model using inverse distance weighting. The results suggest that different landscapes require different filtering methods for optimal ground point extraction. While iterative surface lowering and TIN densification are fully automated, color-based classification require fine-tuning in order to optimize the filtering results. Finally, we conclude that filtering photogrammetric point clouds could provide a cheap alternative to laser scan surveys for creating digital terrain models in sparsely vegetated areas.

  17. Fixed-point adiabatic quantum search

    NASA Astrophysics Data System (ADS)

    Dalzell, Alexander M.; Yoder, Theodore J.; Chuang, Isaac L.

    2017-01-01

    Fixed-point quantum search algorithms succeed at finding one of M target items among N total items even when the run time of the algorithm is longer than necessary. While the famous Grover's algorithm can search quadratically faster than a classical computer, it lacks the fixed-point property—the fraction of target items must be known precisely to know when to terminate the algorithm. Recently, Yoder, Low, and Chuang [Phys. Rev. Lett. 113, 210501 (2014), 10.1103/PhysRevLett.113.210501] gave an optimal gate-model search algorithm with the fixed-point property. Previously, it had been discovered by Roland and Cerf [Phys. Rev. A 65, 042308 (2002), 10.1103/PhysRevA.65.042308] that an adiabatic quantum algorithm, operating by continuously varying a Hamiltonian, can reproduce the quadratic speedup of gate-model Grover search. We ask, can an adiabatic algorithm also reproduce the fixed-point property? We show that the answer depends on what interpolation schedule is used, so as in the gate model, there are both fixed-point and non-fixed-point versions of adiabatic search, only some of which attain the quadratic quantum speedup. Guided by geometric intuition on the Bloch sphere, we rigorously justify our claims with an explicit upper bound on the error in the adiabatic approximation. We also show that the fixed-point adiabatic search algorithm can be simulated in the gate model with neither loss of the quadratic Grover speedup nor of the fixed-point property. Finally, we discuss natural uses of fixed-point algorithms such as preparation of a relatively prime state and oblivious amplitude amplification.

  18. Antenna pointing compensation based on precision optical measurement techniques

    NASA Technical Reports Server (NTRS)

    Schumacher, L. L.; Vivian, H. C.

    1988-01-01

    The pointing control loops of the Deep Space Network 70 meter antennas extend only to the Intermediate Reference Structure (IRS). Thus, distortion of the structure forward of the IRS due to unpredictable environmental loads can result in uncompensated boresight shifts which degrade blind pointing accuracy. A system is described which can provide real time bias commands to the pointing control system to compensate for environmental effects on blind pointing performance. The bias commands are computed in real time based on optical ranging measurements of the structure from the IRS to a number of selected points on the primary and secondary reflectors.

  19. An unsteady stagnation-point flow

    NASA Astrophysics Data System (ADS)

    Riley, N.; Vasantha, R.

    1989-11-01

    The oscillatory flow at a two-dimensional stagnation point is studied. It is shown that, following the initiation of the motion, the solution always develops a singularity at a finite time. The implications of this finding for the flow over a cylinder which performs transverse harmonic oscillations are discussed.

  20. Point discharge current measurements beneath dust devils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We document for the first time observations of point discharge currents under dust devils using a novel compact sensor deployed in summer 2016 at the USDA-ARS Jornada Experimental Range in New Mexico, USA. A consistent signature is noted in about a dozen events seen over 40 days, with a positive cur...

  1. Misuse the Power, Miss the Point

    ERIC Educational Resources Information Center

    Lonergan, David

    2011-01-01

    In this article, the author addresses a problem that plagues virtually all academics, as well as most people in business, K-12 education, and many other walks of life. At one time or another most members of post-millennial western society have suffered through that most hideous of well-intentioned experiences, the botched PowerPoint presentation.…

  2. Active Learning: A PowerPoint Tutorial

    ERIC Educational Resources Information Center

    Gareis, Elisabeth

    2007-01-01

    Individual or group presentations are common assignments in business communication courses, and many students use PowerPoint slides as audiovisual support. Frequently, curriculum constraints don't allow instructors much time to teach effective design and delivery of presentation graphics in their courses; guidelines in the form of minilectures or…

  3. An integrated paper-based sample-to-answer biosensor for nucleic acid testing at the point of care.

    PubMed

    Choi, Jane Ru; Hu, Jie; Tang, Ruihua; Gong, Yan; Feng, Shangsheng; Ren, Hui; Wen, Ting; Li, XiuJun; Wan Abas, Wan Abu Bakar; Pingguan-Murphy, Belinda; Xu, Feng

    2016-02-07

    With advances in point-of-care testing (POCT), lateral flow assays (LFAs) have been explored for nucleic acid detection. However, biological samples generally contain complex compositions and low amounts of target nucleic acids, and currently require laborious off-chip nucleic acid extraction and amplification processes (e.g., tube-based extraction and polymerase chain reaction (PCR)) prior to detection. To the best of our knowledge, even though the integration of DNA extraction and amplification into a paper-based biosensor has been reported, a combination of LFA with the aforementioned steps for simple colorimetric readout has not yet been demonstrated. Here, we demonstrate for the first time an integrated paper-based biosensor incorporating nucleic acid extraction, amplification and visual detection or quantification using a smartphone. A handheld battery-powered heating device was specially developed for nucleic acid amplification in POC settings, which is coupled with this simple assay for rapid target detection. The biosensor can successfully detect Escherichia coli (as a model analyte) in spiked drinking water, milk, blood, and spinach with a detection limit of as low as 10-1000 CFU mL(-1), and Streptococcus pneumonia in clinical blood samples, highlighting its potential use in medical diagnostics, food safety analysis and environmental monitoring. As compared to the lengthy conventional assay, which requires more than 5 hours for the entire sample-to-answer process, it takes about 1 hour for our integrated biosensor. The integrated biosensor holds great potential for detection of various target analytes for wide applications in the near future.

  4. A Contract That Manages Itself: The Time Has Arrived

    DTIC Science & Technology

    2015-02-01

    study of being. In this context, ontology involves describing information and relationships in an informative way. That sounds like a database. But...ApprovedOMB No. 0704-0188 Public reporting burden for the collection of information is estimated to average 1 hour per response, including the time for... information . Send comments regarding this burden estimate or any other aspect of this collection of information , including suggestions for reducing this burden

  5. Fermat's point from five perspectives

    NASA Astrophysics Data System (ADS)

    Park, Jungeun; Flores, Alfinio

    2015-04-01

    The Fermat point of a triangle is the point such that minimizes the sum of the distances from that point to the three vertices. Five approaches to study the Fermat point of a triangle are presented in this article. First, students use a mechanical device using masses, strings and pulleys to study the Fermat point as the one that minimizes the potential energy of the system. Second, students use soap films between parallel planes connecting three pegs. The tension on the film will be minimal when the sum of distances is minimal. Third, students use an empirical approach, measuring distances in an interactive GeoGebra page. Fourth, students use Euclidean geometry arguments for two proofs based on the Torricelli configuration, and one using Viviani's Theorem. And fifth, the kinematic method is used to gain additional insight on the size of the angles between the segments joining the Fermat point with the vertices.

  6. Point contact silicon solar cells

    NASA Technical Reports Server (NTRS)

    Swanson, Richard M.

    1987-01-01

    A new type of silicon solar cell has been developed. It is called the point-contact cell because the metal semiconductor contacts are restricted to an array of small points on the back of the cell. The point contact cell has recently demonstrated 22 percent conversion efficiency at one sun and 27.5 percent at 100 suns under an AM1.5 spectrum.

  7. Method of forming pointed structures

    NASA Technical Reports Server (NTRS)

    Pugel, Diane E. (Inventor)

    2011-01-01

    A method of forming an array of pointed structures comprises depositing a ferrofluid on a substrate, applying a magnetic field to the ferrofluid to generate an array of surface protrusions, and solidifying the surface protrusions to form the array of pointed structures. The pointed structures may have a tip radius ranging from approximately 10 nm to approximately 25 micron. Solidifying the surface protrusions may be carried out at a temperature ranging from approximately 10 degrees C. to approximately 30 degrees C.

  8. Error Mitigation of Point-to-Point Communication for Fault-Tolerant Computing

    NASA Technical Reports Server (NTRS)

    Akamine, Robert L.; Hodson, Robert F.; LaMeres, Brock J.; Ray, Robert E.

    2011-01-01

    Fault tolerant systems require the ability to detect and recover from physical damage caused by the hardware s environment, faulty connectors, and system degradation over time. This ability applies to military, space, and industrial computing applications. The integrity of Point-to-Point (P2P) communication, between two microcontrollers for example, is an essential part of fault tolerant computing systems. In this paper, different methods of fault detection and recovery are presented and analyzed.

  9. Fixed Point Implementations of Fast Kalman Algorithms.

    DTIC Science & Technology

    1983-11-01

    fined point multiply. ve &geete a meatn ’C.- nero. variance N random vector s~t) each time weAfilter is said to be 12 Scaled if udae 8(t+11t0 - 3-1* AS...nl.v by bl ’k rn.b.) 20 AST iA C T ’Cnnin to .- a , o. a ide It .,oco ea ry and Idenuty by block number) In this paper we study scaling rules and round...realized in a -fast form that uses the so-called fast Kalman gain algorithm. The algorithm for the gain is fixed point. Scaling rules and expressions for

  10. Real-time GPS positioning of the Pacific Northwest Geodetic Array

    NASA Astrophysics Data System (ADS)

    Rabak, I.; Santillan, V. M.; Scrivner, C. W.; Melbourne, T. I.

    2009-12-01

    The Pacific Northwest Geodetic Array (PANGA) is now comprised of nearly 130 continuously operating GPS receivers located throughout the Cascadia subduction zone. The stations straddle active crustal faults, volcanoes and landslides, they span the megathrust forearc and tsunamigenic regions along the Pacific coast, and they monitor ageing man-made structures such as dams, levees and elevated freeways. All data are streamed in real-time into CWU where they are processed in real-time into station position and tropospheric water content within a reference frame defined in central Washington. To disseminate these streams, we currently provide 16 station position streams via an interface to Google Maps to present geographically the three component real-time plots in 5 min, 1 hour, and 24 hour time periods. The user's web browser makes repeated requests at a refresh rate of 5 seconds and after the initial request it only requests new data points from the web server. The 5 min real-time plot is updated every second. The web server provides the data streams in a compact JSON (JavaScript Object Notation) form and data plotting is handled by the user's web browser. The data streams are parsed into JavaScript arrays and plotted using the new HTML5 "canvas" element. This approach produces faster response times for the data streams, and by reducing the load on the web server, allows distribution to large numbers of users. Data are also available via a dedicated Ntrip/TCP-IP socket interface. These real-time data are now being used to monitor geodetic displacements caused by earthquakes, volcanic eruptions and landslides; current efforts to develop real-time finite fault inversions and automated alarm systems will be discussed.

  11. Inertial Pointing and Positioning System

    NASA Technical Reports Server (NTRS)

    Yee, Robert (Inventor); Robbins, Fred (Inventor)

    1998-01-01

    An inertial pointing and control system and method for pointing to a designated target with known coordinates from a platform to provide accurate position, steering, and command information. The system continuously receives GPS signals and corrects Inertial Navigation System (INS) dead reckoning or drift errors. An INS is mounted directly on a pointing instrument rather than in a remote location on the platform for-monitoring the terrestrial position and instrument attitude. and for pointing the instrument at designated celestial targets or ground based landmarks. As a result. the pointing instrument and die INS move independently in inertial space from the platform since the INS is decoupled from the platform. Another important characteristic of the present system is that selected INS measurements are combined with predefined coordinate transformation equations and control logic algorithms under computer control in order to generate inertial pointing commands to the pointing instrument. More specifically. the computer calculates the desired instrument angles (Phi, Theta. Psi). which are then compared to the Euler angles measured by the instrument- mounted INS. and forms the pointing command error angles as a result of the compared difference.

  12. BEST POSSIBLE FLOATING POINT ARITHMETIC.

    DTIC Science & Technology

    The report presents an algorithm for floating point arithmetic, using single-length arithmetic registers, which yields the most accurate...approximation which can be expressed in the given floating point format, the greatest lower bound, or the least upper bound for the result of the operation

  13. PowerPointing the Way.

    ERIC Educational Resources Information Center

    Stafford, Deborah J.

    1997-01-01

    Describes instructional uses of Microsoft PowerPoint software as demonstrated in a summer workshop for educators. Notes three uses: open house-type presentations, tutorials, and student-produced projects. Discusses how PowerPoint was used to present general information about the school and gives examples of uses in science and music history…

  14. Brocard Point and Euler Function

    ERIC Educational Resources Information Center

    Sastry, K. R. S.

    2007-01-01

    This paper takes a known point from Brocard geometry, a known result from the geometry of the equilateral triangle, and bring in Euler's [empty set] function. It then demonstrates how to obtain new Brocard Geometric number theory results from them. Furthermore, this paper aims to determine a [triangle]ABC whose Crelle-Brocard Point [omega]…

  15. NON-POINT SOURCE POLLUTION

    EPA Science Inventory

    Non-point source pollution is a diffuse source that is difficult to measure and is highly variable due to different rain patterns and other climatic conditions. In many areas, however, non-point source pollution is the greatest source of water quality degradation. Presently, stat...

  16. Planetary system detection by POINTS

    NASA Technical Reports Server (NTRS)

    Reasenberg, Robert D.

    1993-01-01

    The final report and semiannual reports 1, 2, and 3 in response to the study of 'Planetary System Detection by POINTS' is presented. The grant covered the period from 15 Jun. 1988 through 31 Dec. 1989. The work during that period comprised the further development and refinement of the POINTS concept. The status of the POINTS development at the end of the Grant period was described by Reasenberg in a paper given at the JPL Workshop on Space Interferometry, 12-13 Mar. 1990, and distributed as CfA Preprint 3138. That paper, 'POINTS: a Small Astrometric Interferometer,' follows as Appendix-A. Our proposal P2276-7-09, dated July 1990, included a more detailed description of the state of the development of POINTS at the end of the tenure of Grant NAGW-1355. That proposal, which resulted in Grant NAGW-2497, is included by reference.

  17. New Observations of Subarcsecond Photospheric Bright Points

    NASA Technical Reports Server (NTRS)

    Berger, T. E.; Schrijver, C. J.; Shine, R. A.; Tarbell, T. D.; Title, A. M.; Scharmer, G.

    1995-01-01

    We have used an interference filter centered at 4305 A within the bandhead of the CH radical (the 'G band') and real-time image selection at the Swedish Vacuum Solar Telescope on La Palma to produce very high contrast images of subarcsecond photospheric bright points at all locations on the solar disk. During the 6 day period of 1993 September 15-20 we observed active region NOAA 7581 from its appearance on the East limb to a near-disk-center position on September 20. A total of 1804 bright points were selected for analysis from the disk center image using feature extraction image processing techniques. The measured Full Width at Half Maximum (FWHM) distribution of the bright points in the image is lognormal with a modal value of 220 km (0 sec .30) and an average value of 250 km (0 sec .35). The smallest measured bright point diameter is 120 km (0 sec .17) and the largest is 600 km (O sec .69). Approximately 60% of the measured bright points are circular (eccentricity approx. 1.0), the average eccentricity is 1.5, and the maximum eccentricity corresponding to filigree in the image is 6.5. The peak contrast of the measured bright points is normally distributed. The contrast distribution variance is much greater than the measurement accuracy, indicating a large spread in intrinsic bright-point contrast. When referenced to an averaged 'quiet-Sun' area in the image, the modal contrast is 29% and the maximum value is 75%; when referenced to an average intergranular lane brightness in the image, the distribution has a modal value of 61% and a maximum of 119%. The bin-averaged contrast of G-band bright points is constant across the entire measured size range. The measured area of the bright points, corrected for pixelation and selection effects, covers about 1.8% of the total image area. Large pores and micropores occupy an additional 2% of the image area, implying a total area fraction of magnetic proxy features in the image of 3.8%. We discuss the implications of this

  18. New Observations of Subarcsecond Photospheric Bright Points

    NASA Technical Reports Server (NTRS)

    Berger, T. E.; Schrijver, C. J.; Shine, R. A.; Tarbell, T. D.; Title, A. M.; Scharmer, G.

    1995-01-01

    We have used an interference filter centered at 4305 A within the bandhead of the CH radical (the 'G band') and real-time image selection at the Swedish Vacuum Solar Telescope on La Palma to produce very high contrast images of subarcsecond photospheric bright points at all locations on the solar disk. During the 6 day period of 15-20 Sept. 1993 we observed active region NOAA 7581 from its appearance on the East limb to a near-disk-center position on 20 Sept. A total of 1804 bright points were selected for analysis from the disk center image using feature extraction image processing techniques. The measured FWHM distribution of the bright points in the image is lognormal with a modal value of 220 km (0.30 sec) and an average value of 250 km (0.35 sec). The smallest measured bright point diameter is 120 km (0.17 sec) and the largest is 600 km (O.69 sec). Approximately 60% of the measured bright points are circular (eccentricity approx. 1.0), the average eccentricity is 1.5, and the maximum eccentricity corresponding to filigree in the image is 6.5. The peak contrast of the measured bright points is normally distributed. The contrast distribution variance is much greater than the measurement accuracy, indicating a large spread in intrinsic bright-point contrast. When referenced to an averaged 'quiet-Sun' area in the image, the modal contrast is 29% and the maximum value is 75%; when referenced to an average intergranular lane brightness in the image, the distribution has a modal value of 61% and a maximum of 119%. The bin-averaged contrast of G-band bright points is constant across the entire measured size range. The measured area of the bright points, corrected for pixelation and selection effects, covers about 1.8% of the total image area. Large pores and micropores occupy an additional 2% of the image area, implying a total area fraction of magnetic proxy features in the image of 3.8%. We discuss the implications of this area fraction measurement in the context of

  19. Controlling superconductivity by tunable quantum critical points.

    PubMed

    Seo, S; Park, E; Bauer, E D; Ronning, F; Kim, J N; Shim, J-H; Thompson, J D; Park, Tuson

    2015-03-04

    The heavy fermion compound CeRhIn5 is a rare example where a quantum critical point, hidden by a dome of superconductivity, has been explicitly revealed and found to have a local nature. The lack of additional examples of local types of quantum critical points associated with superconductivity, however, has made it difficult to unravel the role of quantum fluctuations in forming Cooper pairs. Here, we show the precise control of superconductivity by tunable quantum critical points in CeRhIn5. Slight tin-substitution for indium in CeRhIn5 shifts its antiferromagnetic quantum critical point from 2.3 GPa to 1.3 GPa and induces a residual impurity scattering 300 times larger than that of pure CeRhIn5, which should be sufficient to preclude superconductivity. Nevertheless, superconductivity occurs at the quantum critical point of the tin-doped metal. These results underline that fluctuations from the antiferromagnetic quantum criticality promote unconventional superconductivity in CeRhIn5.

  20. Ocular stability and set-point adaptation.

    PubMed

    Zee, D S; Jareonsettasin, P; Leigh, R J

    2017-04-19

    A fundamental challenge to the brain is how to prevent intrusive movements when quiet is needed. Unwanted limb movements such as tremor impair fine motor control and unwanted eye drifts such as nystagmus impair vision. A stable platform is also necessary to launch accurate movements. Accordingly, nature has designed control systems with agonist (excitation) and antagonist (inhibition) muscle pairs functioning in push-pull, around a steady level of balanced tonic activity, the set-point Sensory information can be organized similarly, as in the vestibulo-ocular reflex, which generates eye movements that compensate for head movements. The semicircular canals, working in coplanar pairs, one in each labyrinth, are reciprocally excited and inhibited as they transduce head rotations. The relative change in activity is relayed to the vestibular nuclei, which operate around a set-point of stable balanced activity. When a pathological imbalance occurs, producing unwanted nystagmus without head movement, an adaptive mechanism restores the proper set-point and eliminates the nystagmus. Here we used 90 min of continuous 7 T magnetic field labyrinthine stimulation (MVS) in normal humans to produce sustained nystagmus simulating vestibular imbalance. We identified multiple time-scale processes towards a new zero set-point showing that MVS is an excellent paradigm to investigate the neurobiology of set-point adaptation.This article is part of the themed issue 'Movement suppression: brain mechanisms for stopping and stillness'.

  1. Comparison between one-point calibration and two-point calibration approaches in a continuous glucose monitoring algorithm.

    PubMed

    Mahmoudi, Zeinab; Johansen, Mette Dencker; Christiansen, Jens Sandahl; Hejlesen, Ole

    2014-07-01

    The purpose of this study was to investigate the effect of using a 1-point calibration approach instead of a 2-point calibration approach on the accuracy of a continuous glucose monitoring (CGM) algorithm. A previously published real-time CGM algorithm was compared with its updated version, which used a 1-point calibration instead of a 2-point calibration. In addition, the contribution of the corrective intercept (CI) to the calibration performance was assessed. Finally, the sensor background current was estimated real-time and retrospectively. The study was performed on 132 type 1 diabetes patients. Replacing the 2-point calibration with the 1-point calibration improved the CGM accuracy, with the greatest improvement achieved in hypoglycemia (18.4% median absolute relative differences [MARD] in hypoglycemia for the 2-point calibration, and 12.1% MARD in hypoglycemia for the 1-point calibration). Using 1-point calibration increased the percentage of sensor readings in zone A+B of the Clarke error grid analysis (EGA) in the full glycemic range, and also enhanced hypoglycemia sensitivity. Exclusion of CI from calibration reduced hypoglycemia accuracy, while slightly increased euglycemia accuracy. Both real-time and retrospective estimation of the sensor background current suggest that the background current can be considered zero in the calibration of the SCGM1 sensor. The sensor readings calibrated with the 1-point calibration approach indicated to have higher accuracy than those calibrated with the 2-point calibration approach.

  2. Effective dynamics of a classical point charge

    SciTech Connect

    Polonyi, Janos

    2014-03-15

    The effective Lagrangian of a point charge is derived by eliminating the electromagnetic field within the framework of the classical closed time path formalism. The short distance singularity of the electromagnetic field is regulated by an UV cutoff. The Abraham–Lorentz force is recovered and its similarity to quantum anomalies is underlined. The full cutoff-dependent linearized equation of motion is obtained, no runaway trajectories are found but the effective dynamics shows acausality if the cutoff is beyond the classical charge radius. The strength of the radiation reaction force displays a pole in its cutoff-dependence in a manner reminiscent of the Landau-pole of perturbative QED. Similarity between the dynamical breakdown of the time reversal invariance and dynamical symmetry breaking is pointed out. -- Highlights: •Extension of the classical action principle for dissipative systems. •New derivation of the Abraham–Lorentz force for a point charge. •Absence of a runaway solution of the Abraham–Lorentz force. •Acausality in classical electrodynamics. •Renormalization of classical electrodynamics of point charges.

  3. Reachability and Real-Time Actuation Strategies for the Active SLIP Model

    DTIC Science & Technology

    2015-06-01

    reachability space of the actuated SLIP model by acti- vating the series elastic actuator at any possible time during the stance phase. Starting from the...University of California Santa Barbara Reachability and Real- Time Actuation Strategies for the Active SLIP Model A dissertation submitted in partial...Public reporting burden for the collection of information is estimated to average 1 hour per response, including the time for reviewing instructions

  4. Pivots for Pointing: Visually-Monitored Pointing Has Higher Arm Elevations than Pointing Blindfolded

    ERIC Educational Resources Information Center

    Wnuczko, Marta; Kennedy, John M.

    2011-01-01

    Observers pointing to a target viewed directly may elevate their fingertip close to the line of sight. However, pointing blindfolded, after viewing the target, they may pivot lower, from the shoulder, aligning the arm with the target as if reaching to the target. Indeed, in Experiment 1 participants elevated their arms more in visually monitored…

  5. NOTE: Do acupuncture points exist?

    NASA Astrophysics Data System (ADS)

    Yan, Xiaohui; Zhang, Xinyi; Liu, Chenglin; Dang, Ruishan; Huang, Yuying; He, Wei; Ding, Guanghong

    2009-05-01

    We used synchrotron x-ray fluorescence analysis to probe the distribution of four chemical elements in and around acupuncture points, two located in the forearm and two in the lower leg. Three of the four acupuncture points showed significantly elevated concentrations of elements Ca, Fe, Cu and Zn in relation to levels in the surrounding tissue, with similar elevation ratios for Cu and Fe. The mapped distribution of these elements implies that each acupuncture point seems to be elliptical with the long axis along the meridian.

  6. Davies Critical Point and Tunneling

    NASA Astrophysics Data System (ADS)

    La, Hoseong

    2012-04-01

    From the point of view of tunneling, the physical meaning of the Davies critical point of a second-order phase transition in the black hole thermodynamics is clarified. At the critical point, the nonthermal contribution vanishes so that the black hole radiation is entirely thermal. It separates two phases: one with radiation enhanced by the nonthermal contribution, the other suppressed by the nonthermal contribution. We show this in both charged and rotating black holes. The phase transition is also analyzed in the cases in which emissions of charges and angular momenta are incorporated.

  7. Effects of Point Mutations in Plasmodium falciparum Dihydrofolate Reductase and Dihydropterate Synthase Genes on Clinical Outcomes and In Vitro Susceptibility to Sulfadoxine and Pyrimethamine

    DTIC Science & Technology

    2009-08-01

    Alejandro Llanos-Cuentas4, Coralith Garcia4, Lelv Solari4, Dennis Kyle5, Alan J. Magill3 1 Parasitology Program, Naval Medical Research Center...5]. PLoS ONE | www.plosone.org 1 August 2009 | Volume 4 | Issue 8 | e6762 Report Documentation Page Form ApprovedOMB No. 0704-0188 Public reporting...burden for the collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing

  8. Pointing Device Performance in Steering Tasks.

    PubMed

    Senanayake, Ransalu; Goonetilleke, Ravindra S

    2016-06-01

    Use of touch-screen-based interactions is growing rapidly. Hence, knowing the maneuvering efficacy of touch screens relative to other pointing devices is of great importance in the context of graphical user interfaces. Movement time, accuracy, and user preferences of four pointing device settings were evaluated on a computer with 14 participants aged 20.1 ± 3.13 years. It was found that, depending on the difficulty of the task, the optimal settings differ for ballistic and visual control tasks. With a touch screen, resting the arm increased movement time for steering tasks. When both performance and comfort are considered, whether to use a mouse or a touch screen for person-computer interaction depends on the steering difficulty. Hence, a input device should be chosen based on the application, and should be optimized to match the graphical user interface.

  9. Effects of directional uncertainty on visually-guided joystick pointing.

    PubMed

    Berryhill, Marian; Kveraga, Kestutis; Hughes, Howard C

    2005-02-01

    Reaction times generally follow the predictions of Hick's law as stimulus-response uncertainty increases, although notable exceptions include the oculomotor system. Saccadic and smooth pursuit eye movement reaction times are independent of stimulus-response uncertainty. Previous research showed that joystick pointing to targets, a motor analog of saccadic eye movements, is only modestly affected by increased stimulus-response uncertainty; however, a no-uncertainty condition (simple reaction time to 1 possible target) was not included. Here, we re-evaluate manual joystick pointing including a no-uncertainty condition. Analysis indicated simple joystick pointing reaction times were significantly faster than choice reaction times. Choice reaction times (2, 4, or 8 possible target locations) only slightly increased as the number of possible targets increased. These data suggest that, as with joystick tracking (a motor analog of smooth pursuit eye movements), joystick pointing is more closely approximated by a simple/choice step function than the log function predicted by Hick's law.

  10. Articulation points in complex networks

    PubMed Central

    Tian, Liang; Bashan, Amir; Shi, Da-Ning; Liu, Yang-Yu

    2017-01-01

    An articulation point in a network is a node whose removal disconnects the network. Those nodes play key roles in ensuring connectivity of many real-world networks, from infrastructure networks to protein interaction networks and terrorist communication networks. Despite their fundamental importance, a general framework of studying articulation points in complex networks is lacking. Here we develop analytical tools to study key issues pertinent to articulation points, such as the expected number of them and the network vulnerability against their removal, in an arbitrary complex network. We find that a greedy articulation point removal process provides us a different perspective on the organizational principles of complex networks. Moreover, this process results in a rich phase diagram with two fundamentally different types of percolation transitions. Our results shed light on the design of more resilient infrastructure networks and the effective destruction of terrorist communication networks. PMID:28139697

  11. NULL convention floating point multiplier.

    PubMed

    Albert, Anitha Juliette; Ramachandran, Seshasayanan

    2015-01-01

    Floating point multiplication is a critical part in high dynamic range and computational intensive digital signal processing applications which require high precision and low power. This paper presents the design of an IEEE 754 single precision floating point multiplier using asynchronous NULL convention logic paradigm. Rounding has not been implemented to suit high precision applications. The novelty of the research is that it is the first ever NULL convention logic multiplier, designed to perform floating point multiplication. The proposed multiplier offers substantial decrease in power consumption when compared with its synchronous version. Performance attributes of the NULL convention logic floating point multiplier, obtained from Xilinx simulation and Cadence, are compared with its equivalent synchronous implementation.

  12. The Jeanie Point complex revisited

    USGS Publications Warehouse

    Dumoulin, Julie A.; Miller, Martha L.

    1984-01-01

    The so-called Jeanie Point complex is a distinctive package of rocks within the Orca Group, a Tertiary turbidite sequence. The rocks crop out on the southeast coast of Montague Island, Prince William Sound, approximately 3 km northeast of Jeanie Point (loc. 7, fig. 44). These rocks consist dominantly of fine-grained limestone and lesser amounts of siliceous limestone, chert, tuff, mudstone, argillite, and sandstone (fig. 47). The Jeanie Point rocks also differ from those typical of the Orca Group in their fold style. Thus, the Orca Group of the area is isoclinally folded on a large scale (tens to hundreds of meters), whereas the Jeanie Point rocks are tightly folded on a 1- to 3- m-wavelength scale (differences in rock competency may be responsible for this variation in fold style).

  13. NULL Convention Floating Point Multiplier

    PubMed Central

    Ramachandran, Seshasayanan

    2015-01-01

    Floating point multiplication is a critical part in high dynamic range and computational intensive digital signal processing applications which require high precision and low power. This paper presents the design of an IEEE 754 single precision floating point multiplier using asynchronous NULL convention logic paradigm. Rounding has not been implemented to suit high precision applications. The novelty of the research is that it is the first ever NULL convention logic multiplier, designed to perform floating point multiplication. The proposed multiplier offers substantial decrease in power consumption when compared with its synchronous version. Performance attributes of the NULL convention logic floating point multiplier, obtained from Xilinx simulation and Cadence, are compared with its equivalent synchronous implementation. PMID:25879069

  14. Articulation points in complex networks

    NASA Astrophysics Data System (ADS)

    Tian, Liang; Bashan, Amir; Shi, Da-Ning; Liu, Yang-Yu

    2017-01-01

    An articulation point in a network is a node whose removal disconnects the network. Those nodes play key roles in ensuring connectivity of many real-world networks, from infrastructure networks to protein interaction networks and terrorist communication networks. Despite their fundamental importance, a general framework of studying articulation points in complex networks is lacking. Here we develop analytical tools to study key issues pertinent to articulation points, such as the expected number of them and the network vulnerability against their removal, in an arbitrary complex network. We find that a greedy articulation point removal process provides us a different perspective on the organizational principles of complex networks. Moreover, this process results in a rich phase diagram with two fundamentally different types of percolation transitions. Our results shed light on the design of more resilient infrastructure networks and the effective destruction of terrorist communication networks.

  15. Detecting determinism from point processes

    NASA Astrophysics Data System (ADS)

    Andrzejak, Ralph G.; Mormann, Florian; Kreuz, Thomas

    2014-12-01

    The detection of a nonrandom structure from experimental data can be crucial for the classification, understanding, and interpretation of the generating process. We here introduce a rank-based nonlinear predictability score to detect determinism from point process data. Thanks to its modular nature, this approach can be adapted to whatever signature in the data one considers indicative of deterministic structure. After validating our approach using point process signals from deterministic and stochastic model dynamics, we show an application to neuronal spike trains recorded in the brain of an epilepsy patient. While we illustrate our approach in the context of temporal point processes, it can be readily applied to spatial point processes as well.

  16. Tipping point analysis of atmospheric oxygen concentration

    NASA Astrophysics Data System (ADS)

    Livina, Valerie N.; Vaz Martins, Teresa M.; Forbes, Alistair

    2015-04-01

    We apply tipping point analysis to atmospheric oxygen concentration records. We warn that decrease of oxygen concentration from 21% to 19% would lead to significant health problems for humans and other animals, and estimate the time scale of such decline under various antropogenic scenarios. We suggest that society should be careful with introduction of new mass technologies that utilise double sink of atmospheric oxygen by both combustion and air-consuming synthesis in energy generation and product manufacturing.

  17. Hermit Points on a Box

    ERIC Educational Resources Information Center

    Hess, Richard; Grinstead, Charles; Grindstead, Marshall; Bergstrand, Deborah

    2008-01-01

    Suppose that we are given a rectangular box in 3-space. Given any two points on the surface of this box, we can define the surface distance between them to be the length of the shortest path between them on the surface of the box. This paper determines the pairs of points of maximum surface distance for all boxes. It is often the case that these…

  18. Determining critical points in organizational learning modes

    NASA Astrophysics Data System (ADS)

    Hamner, Marvine P.

    2002-07-01

    It has been postulated that organizations can be categorized into one of three perspectives that represent the mind-set of managers within organizations with respect to their organization and organizational learning. These are the normative, the developmental and the capability perspectives. Each of these reflects variations among organizational features such as the source of organizational learning, the timeframe for organizational learning and the relationship between organizational learning and organizational culture. However, much like the dynamics experienced by teams, i.e. various stages such as forming, norming, storming and performing, organizations can move through various learning stages, i.e. the three 'perspectives,' often stopping and restarting at different points in their cycles. This means that the three perspectives can be simply viewed as different modes of organizational learning. All organizations operate within one of the three perspectives all the time. And, the perspective through which the organization is best viewed at any point in time changes over time. Because organizations are complex, adaptive systems these modes can be mathematically represented using the output from a neural network model of complex, adaptive systems. This paper briefly describes the organizational science, the neural network model, and the mathematics required to determine critical points in these modes.

  19. Fixed points and FLRW cosmologies: Flat case

    NASA Astrophysics Data System (ADS)

    Awad, Adel

    2013-05-01

    We use a phase space approach to study possible consequences of fixed points in a single fluid flat Friedmann-Lemaître-Robertson-Walker (FLRW) models with pressure p(H), where H is the Hubble parameter. One of these consequences is that a fluid with a differentiable pressure, i.e., a finite adiabatic speed of sound, reaches a fixed point in an infinite time and has no finite-time singularities of types I, II, and III described by Nojiri, Odintsov, and Tsujikawa [Phys. Rev. D 71, 063004 (2005)]. It is impossible for such a fluid to cross the phantom divide in a finite time. We show that a divergent dp/dH, or the speed of sound, is a necessary but not sufficient condition for phantom crossing. We use pressure properties, such as asymptotic behavior and fixed points, to qualitatively describe the entire behavior of a solution in flat FLRW models. We discuss FLRW models with bulk viscosity η˜ρr, in particular, solutions for r=1 and r=1/4 cases, which can be expressed in terms of the Lambert-W function. The last solution behaves as either a nonsingular phantom fluid or a unified dark fluid. Using causality and stability constraints, we show that the universe must end as a de Sitter space. Relaxing the stability constraint leads to a de Sitter universe, an empty universe, or a turnaround solution that reaches a maximum size and then recollapses.

  20. Optimizing robot placement for visit-point tasks

    SciTech Connect

    Hwang, Y.K.; Watterberg, P.A.

    1996-06-01

    We present a manipulator placement algorithm for minimizing the length of the manipulator motion performing a visit-point task such as spot welding. Given a set of points for the tool of a manipulator to visit, our algorithm finds the shortest robot motion required to visit the points from each possible base configuration. The base configurations resulting in the shortest motion is selected as the optimal robot placement. The shortest robot motion required for visiting multiple points from a given base configuration is computed using a variant of the traveling salesman algorithm in the robot joint space and a point-to-point path planner that plans collision free robot paths between two configurations. Our robot placement algorithm is expected to reduce the robot cycle time during visit- point tasks, as well as speeding up the robot set-up process when building a manufacturing line.

  1. RETENTION TIME EFFECT ON METAL REMOVAL BY PEAT COLUMNS

    SciTech Connect

    Nelson, E

    2007-02-28

    The potential use of a peat bed to treat the H-12 Outfall discharge to bring it to new compliance limits was previously investigated and reported utilizing a 7 hour retention time. The influence of retention time (contact time) of water with peat moss on the removal of copper from the water was investigated under laboratory conditions using vertical flow peat moss columns. Reduction of the necessary retention time has a large influence on the design sizing of any peat bed that would be constructed to treat the H-12 discharge on a full scale basis. Retention times of 5 hours, 3 hours and 1 hour were tested to determine the copper removal by the peat columns using vertical flow. Water samples were collected after 4, 8, 12, and 16 water volumes had passed through the columns and analyzed for a suite of metals, with quantitative emphasis on copper. Laboratory results indicated that copper removal was very high at each of the 3 retention times tested, ranging from 99.6 % removal at 5 and 3 hours to 98.8% removal at 1 hour. All these values are much lower that the new compliance limit for the outfall. The results also indicated that most divalent metals were removed to their normal reporting detection limit for the analytical methods used, including zinc. Lead levels in the H-12 discharge used in this study were below PQL in all samples analyzed. While each of the retention times studied removed copper very well, there were indications that 1 hour is probably too short for an operational, long-term facility. At that retention time, there was about 6% compaction of the peat in the column due to the water velocity, and this may affect long term hydraulic conductivity of the peat bed. At that retention time, copper concentration in the effluent was higher than the other times tested, although still very low. Because of the potential compacting and somewhat reduced removal efficiency at a 1 hour retention time, it would be prudent to design to at least a 3 hour retention

  2. Time Transfer Techniques: Historical Overview, Current Practices and Future Capabilities

    DTIC Science & Technology

    1984-11-01

    Iiurrr .j. Klepcrynski Time St.r:r~cc rlcpurtrnent 0. 5. r.luvr_ll :)lrservutory Wusl-iington, 13, i:. 20390-5 100 A br ief i i istoricnl re vie^ r:jf...Form ApprovedOMB No. 0704-0188 Public reporting burden for the collection of information is estimated to average 1 hour per response, including the time ...DATES COVERED 00-00-1984 to 00-00-1984 4. TITLE AND SUBTITLE Time Transfer Techniques: Historical Overview, Current Practices and Future

  3. Stagnation Point Radiative Heating Relations for Venus Entry

    NASA Technical Reports Server (NTRS)

    Tauber, Michael E.; Palmer, Grant E.; Prabhu, Dinesh K.

    2012-01-01

    Improved analytic expressions for calculating the stagnation point radiative heating during entry into the atmosphere of Venus have been developed. These analytic expressions can be incorporated into entry trajectory simulation codes. Together with analytical expressions for convective heating at the stagnation point, the time-integrated total heat load at the stagnation point is used in determining the thickness of protective material required, and hence the mass of the fore body heatshield of uniform thickness.

  4. Trigger Points: An Anatomical Substratum

    PubMed Central

    Akamatsu, Flávia Emi; Ayres, Bernardo Rodrigues; Saleh, Samir Omar; Hojaij, Flávio; Andrade, Mauro; Hsing, Wu Tu; Jacomo, Alfredo Luiz

    2015-01-01

    This study aimed to bring the trapezius muscle knowledge of the locations where the accessory nerve branches enter the muscle belly to reach the motor endplates and find myofascial trigger points (MTrPs). Although anatomoclinical correlations represent a major feature of MTrP, no previous reports describing the distribution of the accessory nerve branches and their anatomical relationship with MTrP are found in the literature. Both trapezius muscles from twelve adult cadavers were carefully dissected by the authors (anatomy professors and medical graduate students) to observe the exact point where the branches of the spinal accessory nerve entered the muscle belly. Dissection was performed through stratigraphic layers to preserve the motor innervation of the trapezius muscle, which is located deep in the muscle. Seven points are described, four of which are motor points: in all cases, these locations corresponded to clinically described MTrPs. The four points were common in these twelve cadavers. This type of clinical correlation between spinal accessory nerve branching and MTrP is useful to achieve a better understanding of the anatomical correlation of MTrP and the physiopathology of these disorders and may provide a scientific basis for their treatment, rendering useful additional information to therapists to achieve better diagnoses and improve therapeutic approaches. PMID:25811029

  5. Determination of stable points in deformation analysis

    NASA Astrophysics Data System (ADS)

    Vodopivec, F.; Savsek-Safic, S.

    2003-04-01

    Determination of displacements of natural and man-made objects is one of the more demanding tasks of the surveying profession. The underlying problem is in the identification of stability and potential hazards of man-made objects in the time of building and later on, as well as earth movements brought about by natural forces or unsupervised land consumption. Due to a constant emergence of displacements, the identification of size, velocity and periodicity of displacements plays an important role especially in civil engineering, mining and related geosciences. The preliminary condition for the deformation analysis is to measure and process the data of respective epochs carefully in the sense of estimating the quality of a given network. In observations, a special emphasis should be given to detecting and eliminating the gross errors. The characteristic point displacements are identified on the basis of at least two epochs and solely on identical network points. This paper aims at presenting the implementation of the Hannover, Asanin and Mihailovic deformation analysis approaches. For the purpose of testing the approaches a trigonometric network in the shape of a sexangle with a centre point was used. The observations and displacements were simulated, accordingly, for pattern generation of normally distributed random variables the Box and Mueller polar generation method was used. On the basis of geodetic observations and with the use of statistical methods the displacements of a given object are determined. Additionally, a comparison regarding the efficiency of stable point identification according to the deformation analysis approaches has been made.

  6. Myofacial Trigger Points in Advanced Cancer Patients

    PubMed Central

    Hasuo, Hideaki; Ishihara, Tatsuhiko; Kanbara, Kenji; Fukunaga, Mikihiko

    2016-01-01

    Myofascial pain syndrome is started to be recognized as one of important factors of pain in cancer patients. However, no reports on features of myofascial trigger points were found in terminally-ill cancer populations. This time, we encountered 5 patients with myofascial pain syndrome and terminal cancer in whom delirium developed due to increased doses of opioid without a diagnosis of myofascial pain syndrome on initial presentation. The delirium subsided with dose reductions of opioid and treatment of myofascial pain syndrome. The common reason for a delayed diagnosis among the patients included an incomplete palpation of the painful sites, which led to unsuccessful myofascial trigger points identification. The features of myofascial trigger points included single onset in the cancer pain management site with opioid and the contralateral abdominal side muscles of the non-common sites. Withdrawal reflexes associated with cancer pain in the supine position, which are increasingly seen in the terminal cancer patients, were considered to have contributed to this siuation. We consider that careful palpation of the painful site is important, in order to obtain greater knowledge and understanding of the features of myofascial trigger points. PMID:26962285

  7. Point and transfer mobility of point-connected ribbed plates

    NASA Astrophysics Data System (ADS)

    Mayr, A. R.; Gibbs, B. M.

    2011-09-01

    The work reported in this paper addresses the problem of structure-borne sound transmission between vibrating sources and ribbed-plate receiver structures. Vibrating sources, such as pumps, motors, fans, etc., transmit vibro-acoustic power, causing noise complaints by occupants in cars, trains, aircraft, buildings and/or material fatigue and damage. The transmission process is complicated in that sources transmit power through several contacts and by up to six components of excitation at each contact. The structure-borne sound power is a function of source activity, source mobility and receiver mobility, and all three quantities must be known to some degree. For non-homogeneous receiver structures, such as thin-plate cavity constructions or lightweight framed constructions, the sheathing plates are typically fastened to the framing members using bolts, screws or spot-welded joints. Hence the resulting system is a point-connected ribbed plate structure and the receiver mobility is expected to vary significantly with position. Since measured receiver data seldom is available for prediction purposes, a method of estimating the point and transfer mobility of point connected ribbed plates is required. In this paper, an approximate approach, based on substitution forces, is described. The model uses infinite beam and infinite plate behaviour as input quantities. Estimates of point and transfer mobility are compared with measured results using a timber joist floor construction as an example.

  8. Point to point continuum percolation in two dimensions

    NASA Astrophysics Data System (ADS)

    Sadeghnejad, S.; Masihi, M.

    2016-10-01

    The outcome of the classic percolation approach is several power-law curves with some universal (critical) exponents. Here, the universality means that these power laws as well as their critical exponents, which control the global properties of a system, are independent of its details. Classic percolation considers the connectivity between two lines and two faces at opposite sides of a system in 2- and 3D problems, respectively; whereas, in practice (e.g. hydrocarbon formations), production and injection wells are represented by points (in 2D areal models) and lines (in 3D models). This study presents the results of Monte Carlo simulations of a 2D percolation model wherein the connection locations (i.e. wells) are represented by two points, called point-to-point (P2P) connectivity. The main contribution is to find the percolation threshold as well as the geometrical and dynamical critical exponents of a continuum percolation system with a P2P connection, which is closer to reality in some applications. The result shows that in comparison to classical percolation, some critical exponents definitely changes in the P2P connection.

  9. Photonic crystals possessing single and double Weyl points (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Chan, Che Ting

    2016-09-01

    The concepts of topological states have captured much attention in condensed-matter physics and the importance of these systems is subsequently realized in other subfields, such as cold atom and classical waves. In the past few years, the attention was focused on "topological insulators" while very recently, the attention is shifting to "Weyl semi-metals" which have gapless bulk band structures with pairs of topological points (called Weyl points) and topologically-protected surface states. In this work, we designed, fabricated and experimentally characterized a Weyl photonic crystal with both single and double Weyl points. We used tight-binding Hamiltonian as a starting point to guide us to the structures that have the correct symmetry to support topological features including synthetic gauge flux and associated Weyl points. We fabricated for the first time a system that exhibits Weyl points of topological charge higher than 1. In our photonic crystal, the existence of the double Weyl point is made possible by the degeneracy between the two single Weyl points which is protected by C3 symmetry and time reversal. Once the C3 symmetry is broken, two Weyl points with charge of ±1 will separate and each forms a linear dispersion in all three directions. Nontrivial 2D bulk band gaps for fixed kz and Weyl points were confirmed by angle-resolved transmission spectra. The robustness of the associated surface states against kz-preserved scattering was experimentally observed.

  10. A CMOS floating point multiplier

    NASA Astrophysics Data System (ADS)

    Uya, M.; Kaneko, K.; Yasui, J.

    1984-10-01

    This paper describes a 32-bit CMOS floating point multiplier. The chip can perform 32-bit floating point multiplication (based on the proposed IEEE Standard format) and 24-bit fixed point multiplication (two's complement format) in less than 78.7 and 71.1 ns, respectively, and the typical power dissipation is 195 mW at 10 million operations per second. High-speed multiplication techniques - a modified Booth's allgorithm, a carry save adder scheme, a high-speed CMOS full adder, and a modified carry select adder - are used to achieve the above high performance. The chip is designed for compatibility with 16-bit microcomputer systems, and is fabricated in 2 micron n-well CMOS technology; it contains about 23000 transistors of 5.75 x 5.67 sq mm in size.

  11. Thermodynamic curvature from the critical point to the triple point.

    PubMed

    Ruppeiner, George

    2012-08-01

    I evaluate the thermodynamic curvature R for fourteen pure fluids along their liquid-vapor coexistence curves, from the critical point to the triple point, using thermodynamic input from the NIST Chemistry WebBook. In this broad overview, R is evaluated in both the coexisting liquid and vapor phases. R is an invariant whose magnitude |R| is a measure of the size of mesoscopic organized structures in a fluid, and whose sign specifies whether intermolecular interactions are effectively attractive (R<0) or repulsive (R>0). I discuss five principles for R in pure fluids: (1) Near the critical point, the attractive part of the interactions forms loose structures of size |R| proportional to the correlation volume ξ(3), and the sign of R is negative. (2) In the vapor phase, there are instances of compact clusters of size |R| formed by the attractive part of the interactions and prevented from collapse by the repulsive part of the interactions, and the sign of R is positive. (3) In the asymptotic critical point regime, the R's in the coexisting liquid and vapor phases are equal to each other, i.e., commensurate. (4) Outside the asymptotic critical-point regime incommensurate R's may be associated with metastability. (5) The compact liquid phase has |R| on the order of the volume of a molecule, with the sign of R being negative for a liquidlike state held together by attractive interactions and the sign of R being positive for a solidlike state held up by repulsive interactions. These considerations amplify and extend the application of thermodynamic curvature in pure fluids.

  12. Tipping Points in Texas Rivers

    NASA Astrophysics Data System (ADS)

    Phillips, Jonathan

    2016-04-01

    Anticipating geomorphic tipping points requires that we learn from the past. Major geomorphic changes in coastal plain rivers of Texas resulting in river metamorphosis or regime shifts were identified, and the major driving factors determined. Nine fluvial tipping points were identified from contemporary observations, historical records, and Quaternary reconstructions. Two of the tipping points (between general aggrading and degrading valley states) are associated with reversals in a fundamental system control (sea-level). One (stable or aggrading vs. degrading channels) is associated with an abrupt change in sediment supply due to dam construction, and two others (changes from meandering to anastomosing channel patterns, and different anastomosis styles) are similarly related to changes in sediment supply and/or transport capacity, but with additional elements of historical contingency. Three tipping points are related to avulsions. One, from a regime dominated to reoccupation of former channels to one dominated by progradation into flood basins, is driven by progressive long term filling of incised valleys. Another, nodal avulsions, are driven by disturbances associated with tectonics or listric faults. The third, avulsions and related valley metamorphosis in unfilled incised valleys, is due to fundamental dynamical instabilities within the fluvial system. This synthesis and analysis suggests that geomorphic tipping points are sometimes associated with general extrinsic or intrinsic (to the fluvial system) environmental change, independent of any disturbances or instabilities. Others are associated with natural (e.g., tectonic) or human (dams) disturbances, and still others with intrinsic geomorphic instabilities. This suggests that future tipping points will be equally diverse with respect to their drivers.

  13. Point estimates for probability moments

    PubMed Central

    Rosenblueth, Emilio

    1975-01-01

    Given a well-behaved real function Y of a real random variable X and the first two or three moments of X, expressions are derived for the moments of Y as linear combinations of powers of the point estimates y(x+) and y(x-), where x+ and x- are specific values of X. Higher-order approximations and approximations for discontinuous Y using more point estimates are also given. Second-moment approximations are generalized to the case when Y is a function of several variables. PMID:16578731

  14. Isotropic and anisotropic pointing models

    NASA Astrophysics Data System (ADS)

    Pál, András; Vida, Krisztián; Mészáros, László; Mező, György

    2016-02-01

    This paper describes an alternative approach for generating pointing models for telescopes equipped with serial kinematics, esp. equatorial or alt-az mounts. Our model construction does not exploit any assumption for the underlying physical constraints of the mount, however, one can assign various effects to the respective components of the equations. In order to recover the pointing model parameters, classical linear least squares fitting procedures can be applied. This parameterization also lacks any kind of parametric singularity. We demonstrate the efficiency of this type of model on real measurements with meter-class telescopes where the results provide a root mean square accuracy of 1.5-2 arcseconds.

  15. Cumulants of Hawkes point processes

    NASA Astrophysics Data System (ADS)

    Jovanović, Stojan; Hertz, John; Rotter, Stefan

    2015-04-01

    We derive explicit, closed-form expressions for the cumulant densities of a multivariate, self-exciting Hawkes point process, generalizing a result of Hawkes in his earlier work on the covariance density and Bartlett spectrum of such processes. To do this, we represent the Hawkes process in terms of a Poisson cluster process and show how the cumulant density formulas can be derived by enumerating all possible "family trees," representing complex interactions between point events. We also consider the problem of computing the integrated cumulants, characterizing the average measure of correlated activity between events of different types, and derive the relevant equations.

  16. Method of reflection point correlation seismic surveying

    SciTech Connect

    Barbier, M.G.; Staron, P.J.

    1982-02-16

    A method of seismic exploration comprises transmitting waves from transmission sources into the medium to be explored and picking up signals in a receiver and recording these as traces, the signals being produced by reflection in the medium, the sequential transmission of the sources taking place at intervals less than the reflection time of the longest transmitted waves, the repeated transmission of any one source taking place at intervals at least equal to the said reflection time and therein being an intercorrelation function of a series of transmission instants of all the sources and a series of transmission instants of any one of the sources to give a relationship between the maximum peak amplitude and the secondary residue amplitude greater than a predetermined value and grouping the recorded traces corresponding to the same reflection point, adjusting the traces in relation to the associated source providing the information relating to the reflection point and adding together the adjusted traces relating to the same reflection point.

  17. Point Positioning Service for Natural Hazard Monitoring

    NASA Astrophysics Data System (ADS)

    Bar-Sever, Y. E.

    2014-12-01

    In an effort to improve natural hazard monitoring, JPL has invested in updating and enlarging its global real-time GNSS tracking network, and has launched a unique service - real-time precise positioning for natural hazard monitoring, entitled GREAT Alert (GNSS Real-Time Earthquake and Tsunami Alert). GREAT Alert leverages the full technological and operational capability of the JPL's Global Differential GPS System [www.gdgps.net] to offer owners of real-time dual-frequency GNSS receivers: Sub-5 cm (3D RMS) real-time, absolute positioning in ITRF08, regardless of location Under 5 seconds turnaround time Full covariance information Estimates of ancillary parameters (such as troposphere) optionally provided This service enables GNSS networks operators to instantly have access to the most accurate and reliable real-time positioning solutions for their sites, and also to the hundreds of participating sites globally, assuring inter-consistency and uniformity across all solutions. Local authorities with limited technical and financial resources can now access to the best technology, and share environmental data to the benefit of the entire pacific region. We will describe the specialized precise point positioning techniques employed by the GREAT Alert service optimized for natural hazard monitoring, and in particular Earthquake monitoring. We address three fundamental aspects of these applications: 1) small and infrequent motion, 2) the availability of data at a central location, and 3) the need for refined solutions at several time scales

  18. [Consideration of the newly standardized interventional reference point].

    PubMed

    Sakamoto, Hajime; Aikawa, Yoshihito; Ikegawa, Hiroaki; Sano, Yoshitomo; Araki, Tsutomu

    2004-04-01

    The interventional reference point is standardized by the International Electrotechnical Commission (IEC), and is adapted to adult cardiovascular studies. We examined the precision of the indicated incident dose at the interventional reference point. As a fundamental examination, we compared entrance phantom dose and incident dose at the interventional reference point. We also compared the entrance skin dose of patients with incident dose at the interventional reference point and evaluated the possibility of clinical application. Results showed that the incident dose at the interventional reference point indicated an underestimation of 0.77 times to an overestimation of 2.2 times when representing entrance surface dose. In clinical application, the incident dose at the interventional reference point calculated from the dose area product tended to overestimate by about 1.17 times the entrance skin dose measured by thermoluminescence dosimeter (TLD). Furthermore, the evaluation varied according to the angles of the C-arm of the x-ray system. A interventional reference point is a useful standard for simple, real-time dose measurement by the indirect method. It is important to understand the characteristics of the indicated incident dose at the interventional reference point in clinical use.

  19. 49 CFR 236.334 - Point detector.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Instructions § 236.334 Point detector. Point detector shall be maintained so that when switch mechanism is... switch point. Point detector circuit controller shall be maintained so that the contacts will not assume the position corresponding to switch point closure if the switch point is prevented by an...

  20. 49 CFR 236.334 - Point detector.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Instructions § 236.334 Point detector. Point detector shall be maintained so that when switch mechanism is... switch point. Point detector circuit controller shall be maintained so that the contacts will not assume the position corresponding to switch point closure if the switch point is prevented by an...

  1. Energy-efficient technologies for point-to-point fiber access

    NASA Astrophysics Data System (ADS)

    Lee, Ka-Lun; Li, Jie; Chan, Chien Aun; Anthapadmanabhan, N. Prasanth; Chow, Hungkei (Keith)

    2015-12-01

    This article discusses the fundamental issues and the technologies to achieve an energy-efficient Gigabit-Ethernet point-to-point (PtP) fiber access network. To minimize the power consumption of PtP fiber access for long-term development, it is essential to optimize each of the network components such as optical transceiver, user network interface, Ethernet aggregator and also their modes of operation. Our analysis shows that the energy consumption of a PtP fiber access network using our proposed technologies can be up to 7.5 times lower than that of the 2010 technologies when a combination of appropriate technologies is applied.

  2. Collocation points distributions for optimal spacecraft trajectories

    NASA Astrophysics Data System (ADS)

    Fumenti, Federico; Circi, Christian; Romagnoli, Daniele

    2013-03-01

    The method of direct collocation with nonlinear programming (DCNLP) is a powerful tool to solve optimal control problems (OCP). In this method the solution time history is approximated with piecewise polynomials, which are constructed using interpolation points deriving from the Jacobi polynomials. Among the Jacobi polynomials family, Legendre and Chebyshev polynomials are the most used, but there is no evidence that they offer the best performance with respect to other family members. By solving different OCPs with interpolation points not only taken within the Jacoby family, the behavior of the Jacobi polynomials in the optimization problems is discussed. This paper focuses on spacecraft trajectories optimization problems. In particular orbit transfers, interplanetary transfers and station keepings are considered.

  3. A miniaturized pointing mount for Spacelab missions

    NASA Technical Reports Server (NTRS)

    Fritz, C. G.; Howell, T., Jr.; Nicaise, P. D.; Parker, J. R.

    1975-01-01

    A Miniaturized Pointing Mount (MPM) for Spacelab missions is defined and simulation results are described. This mount is proposed to complement the Spacelab Instrument Pointing System (IPS). It uses the same mount isolator concept as the Spacelab IPS but is much more efficient and economical for the accommodation of small shuttle payloads. The MPM is built from star tracker assemblies left over from the Apollo Telescope Mount program thereby assuring low cost and development risk. Simulation results indicate a high level of instrument stability can be expected. The short development time of the MPM would permit it to serve as a precursor to the Spacelab IPS for verifying critical new concepts such as the mount isolation and hold down mechanisms.

  4. Multiple Kernel Point Set Registration.

    PubMed

    Nguyen, Thanh Minh; Wu, Q M Jonathan

    2015-12-22

    The finite Gaussian mixture model with kernel correlation is a flexible tool that has recently received attention for point set registration. While there are many algorithms for point set registration presented in the literature, an important issue arising from these studies concerns the mapping of data with nonlinear relationships and the ability to select a suitable kernel. Kernel selection is crucial for effective point set registration. We focus here on multiple kernel point set registration. We make several contributions in this paper. First, each observation is modeled using the Student's t-distribution, which is heavily tailed and more robust than the Gaussian distribution. Second, by automatically adjusting the kernel weights, the proposed method allows us to prune the ineffective kernels. This makes the choice of kernels less crucial. After parameter learning, the kernel saliencies of the irrelevant kernels go to zero. Thus, the choice of kernels is less crucial and it is easy to include other kinds of kernels. Finally, we show empirically that our model outperforms state-of-the-art methods recently proposed in the literature.

  5. Multiple Kernel Point Set Registration.

    PubMed

    Nguyen, Thanh Minh; Wu, Q M Jonathan

    2016-06-01

    The finite Gaussian mixture model with kernel correlation is a flexible tool that has recently received attention for point set registration. While there are many algorithms for point set registration presented in the literature, an important issue arising from these studies concerns the mapping of data with nonlinear relationships and the ability to select a suitable kernel. Kernel selection is crucial for effective point set registration. We focus here on multiple kernel point set registration. We make several contributions in this paper. First, each observation is modeled using the Student's t-distribution, which is heavily tailed and more robust than the Gaussian distribution. Second, by automatically adjusting the kernel weights, the proposed method allows us to prune the ineffective kernels. This makes the choice of kernels less crucial. After parameter learning, the kernel saliencies of the irrelevant kernels go to zero. Thus, the choice of kernels is less crucial and it is easy to include other kinds of kernels. Finally, we show empirically that our model outperforms state-of-the-art methods recently proposed in the literature.

  6. High Points of Human Genetics

    ERIC Educational Resources Information Center

    Stern, Curt

    1975-01-01

    Discusses such high points of human genetics as the study of chromosomes, somatic cell hybrids, the population formula: the Hardy-Weinberg Law, biochemical genetics, the single-active X Theory, behavioral genetics and finally how genetics can serve humanity. (BR)

  7. A Personal Point of View.

    ERIC Educational Resources Information Center

    Skophammer, Karen

    2003-01-01

    Describes how to teach students about art concepts during a photography lesson. Explains that students learn about concepts such as: how to take a sharp picture, how to fill the frame and leading lines, and how to focus on point of view in photographs. Includes learning objectives for the lesson. (CMK)

  8. Fixed points of quantum gravity.

    PubMed

    Litim, Daniel F

    2004-05-21

    Euclidean quantum gravity is studied with renormalization group methods. Analytical results for a nontrivial ultraviolet fixed point are found for arbitrary dimensions and gauge fixing parameters in the Einstein-Hilbert truncation. Implications for quantum gravity in four dimensions are discussed.

  9. An efficient floating-point to fixed-point conversion process for biometric algorithm on DaVinci DSP architecture

    NASA Astrophysics Data System (ADS)

    Konvalinka, Ira; Quddus, Azhar; Asraf, Daniel

    2009-05-01

    Today there is no direct path for the conversion of a floating-point algorithm implementation to an optimized fixed-point implementation. This paper proposes a novel and efficient methodology for Floating-point to Fixed-point Conversion (FFC) of biometric Fingerprint Algorithm Library (FAL) on fixed-point DaVinci processor. A general FFC research task is streamlined along smaller tasks which can be accomplished with lower effort and higher certainty. Formally specified in this paper is the optimization target in FFC, to preserve floating-point accuracy and to reduce execution time, while preserving the majority of algorithm code base. A comprehensive eight point strategy is formulated to achieve that target. Both local (focused on the most time consuming routines) and global optimization flow (to optimize across multiple routines) are used. Characteristic phases in the FFC activity are presented using data from employing the proposed FFC methodology to FAL, starting with target optimization specification, to speed optimization breakthroughs, finalized with validation of FAL accuracy after the execution time optimization. FAL implementation resulted in biometric verification time reduction for over a factor of 5, with negligible impact on accuracy. Any algorithm developer facing the task of implementing his floating-point algorithm on DaVinci DSP is expected to benefit from this presentation.

  10. Libration Point Navigation Concepts Supporting Exploration Vision

    NASA Technical Reports Server (NTRS)

    Carpenter, J. Russell; Folta, David C.; Moreau, Michael C.; Gramling, Cheryl J.

    2004-01-01

    Farquhar described several libration point navigation concepts that would appear to support NASA s current exploration vision. One concept is a Lunar Relay Satellite operating in the vicinity of Earth-Moon L2, providing Earth-to-lunar far-side and long- range surface-to-surface navigation and communications capability. Reference [ 1] lists several advantages of such a system in comparison to a lunar orbiting relay satellite constellation. Among these are one or two vs. many satellites for coverage, simplified acquisition and tracking due to very low relative motion, much longer contact times, and simpler antenna pointing. An obvious additional advantage of such a system is that uninterrupted links to Earth avoid performing critical maneuvers "in the blind." Another concept described is the use of Earth-Moon L1 for lunar orbit rendezvous, rather than low lunar orbit as was done for Apollo. This rendezvous technique would avoid large plane change and high fuel cost associated with high latitude landing sites and long stay times. Earth-Moon L1 also offers unconstrained launch windows from the lunar surface. Farquhar claims this technique requires only slightly higher fuel cost than low lunar orbit rendezvous for short-stay equatorial landings. Farquhar also describes an Interplanetary Transportation System that would use libration points as terminals for an interplanetary shuttle. This approach would offer increased operational flexibility in terms of launch windows, rendezvous, aborts, etc. in comparison to elliptical orbit transfers. More recently, other works including Folta[3] and Howell[4] have shown that patching together unstable trajectories departing Earth-Moon libration points with stable trajectories approaching planetary libration points may also offer lower overall fuel costs than elliptical orbit transfers. Another concept Farquhar described was a Deep Space Relay at Earth-Moon IA and/or L5 that would serve as a high data rate optical navigation and

  11. Transient Point Infiltration In The Unsaturated Zone

    NASA Astrophysics Data System (ADS)

    Buecker-Gittel, M.; Mohrlok, U.

    The risk assessment of leaking sewer pipes gets more and more important due to urban groundwater management and environmental as well as health safety. This requires the quantification and balancing of transport and transformation processes based on the water flow in the unsaturated zone. The water flow from a single sewer leakage could be described as a point infiltration with time varying hydraulic conditions externally and internally. External variations are caused by the discharge in the sewer pipe as well as the state of the leakage itself. Internal variations are the results of microbiological clogging effects associated with the transformation processes. Technical as well as small scale laboratory experiments were conducted in order to investigate the water transport from an transient point infiltration. From the technical scale experiment there was evidence that the water flow takes place under transient conditions when sewage infiltrates into an unsaturated soil. Whereas the small scale experiments investigated the hydraulics of the water transport and the associated so- lute and particle transport in unsaturated soils in detail. The small scale experiment was a two-dimensional representation of such a point infiltration source where the distributed water transport could be measured by several tensiometers in the soil as well as by a selective measurement of the discharge at the bottom of the experimental setup. Several series of experiments were conducted varying the boundary and initial con- ditions in order to derive the important parameters controlling the infiltration of pure water from the point source. The results showed that there is a significant difference between the infiltration rate in the point source and the discharge rate at the bottom, that could be explained by storage processes due to an outflow resistance at the bottom. This effect is overlayn by a decreasing water content decreases over time correlated with a decreasing infiltration

  12. Weyl points and line nodes in gapless gyroid photonic crystals

    NASA Astrophysics Data System (ADS)

    Lu, Ling; Fu, Liang; Joannopoulos, John; Soljacic, Marin; MIT Team

    2013-03-01

    Weyl points and line nodes are three-dimensional linear point- and line-degeneracies between two bands. In contrast to Dirac points, which are their two-dimensional analogues, Weyl points are stable in the momentum space and the associated surface states are predicted to be topologically non-trivial. However, Weyl points are yet to be discovered in nature. Here, we report photonic crystals, based on the double-gyroid structures, exhibiting frequency-isolated Weyl points with complete phase diagrams by breaking the parity and time-reversal symmetries. The surface states associated with the non-zero Chern numbers are demonstrated. Line nodes are also found in similar geometries; the associated surface states are shown to be at bands. Our results are based on realistic ``numerical experiments'' with true predictive power and should be readily experimentally realizable at both microwave and optical frequencies.

  13. Weyl points and line nodes in gyroid photonic crystals

    NASA Astrophysics Data System (ADS)

    Lu, Ling; Fu, Liang; Joannopoulos, John D.; Soljačić, Marin

    2013-04-01

    Weyl points and line nodes are three-dimensional linear point and line degeneracies between two bands. In contrast to two-dimensional Dirac points, which are their lower-dimensional analogues, Weyl points are stable in momentum space, and the associated surface states are predicted to be topologically non-trivial. However, Weyl points are yet to be discovered in nature. Here, we report photonic crystals based on double-gyroid structures, exhibiting frequency-isolated Weyl points with complete phase diagrams by breaking the parity and time-reversal symmetries. Gapless surface dispersions associated with non-zero Chern numbers are demonstrated. Line nodes are also found in similar geometries, the associated surface states forming flat dispersion bands. Our results are based on realistic ab initio calculations with true predictive power and should be readily realizable experimentally from microwave to optical frequencies.

  14. Mirror Identification and Correction of 3d Point Clouds

    NASA Astrophysics Data System (ADS)

    Käshammer, P.-F.; Nüchter, A.

    2015-02-01

    In terrestrial laser scanning (TLS), the surface geometry of objects is scanned by laser beams and recorded digitally. This produces a discrete set of scan points, commonly referred to as a point cloud. The coordinates of the scan points are determined by measuring the angles and the time-of-flight relative to the origin (scanner position). However, if it comes to mirror surfaces laser beams are fully reflected, due to the high reflectivity. Mirrors do not appear in the point cloud at all. Instead, for every reflected beam, a incorrect scan point is created behind the actual mirror plane. Consequently, problems arise in multiple derived application fields such as 3D virtual reconstruction of complex architectures. The paper presents a new approach to automatically detect framed rectangular mirrors with known dimensions and to correct the 3D point cloud, using the calculated mirror plane.

  15. Femtosecond photoelectron point projection microscope

    SciTech Connect

    Quinonez, Erik; Handali, Jonathan; Barwick, Brett

    2013-10-15

    By utilizing a nanometer ultrafast electron source in a point projection microscope we demonstrate that images of nanoparticles with spatial resolutions of the order of 100 nanometers can be obtained. The duration of the emission process of the photoemitted electrons used to make images is shown to be of the order of 100 fs using an autocorrelation technique. The compact geometry of this photoelectron point projection microscope does not preclude its use as a simple ultrafast electron microscope, and we use simple analytic models to estimate temporal resolutions that can be expected when using it as a pump-probe ultrafast electron microscope. These models show a significant increase in temporal resolution when comparing to ultrafast electron microscopes based on conventional designs. We also model the microscopes spectroscopic abilities to capture ultrafast phenomena such as the photon induced near field effect.

  16. EBTR design-point selection

    SciTech Connect

    Krakowski, R.A.; Bathke, C.G.

    1981-01-01

    The procedure used to select the design point for the ELMO Bumpy Torus Reactor (EBTR) study is described. The models used in each phase of the selection process are described, with an emphasis placed on the parametric design curves produced by each model. The tradeoffs related to burn physics, stability/equilibrium, electron-ring physics, and magnetics design are discussed. The resulting design point indicates a plasma with a 35-m major radius and a 1-m minor radium operating at an average core-plasma beta of 0.17, which at approx. 30 keV produces an average neutron wall loading of 1.4 MW/m/sup 2/ while maintaining key magnet (< 10 T) and total power (less than or equal to 4000 MWt) constraints.

  17. Sensing with Superconducting Point Contacts

    PubMed Central

    Nurbawono, Argo; Zhang, Chun

    2012-01-01

    Superconducting point contacts have been used for measuring magnetic polarizations, identifying magnetic impurities, electronic structures, and even the vibrational modes of small molecules. Due to intrinsically small energy scale in the subgap structures of the supercurrent determined by the size of the superconducting energy gap, superconductors provide ultrahigh sensitivities for high resolution spectroscopies. The so-called Andreev reflection process between normal metal and superconductor carries complex and rich information which can be utilized as powerful sensor when fully exploited. In this review, we would discuss recent experimental and theoretical developments in the supercurrent transport through superconducting point contacts and their relevance to sensing applications, and we would highlight their current issues and potentials. A true utilization of the method based on Andreev reflection analysis opens up possibilities for a new class of ultrasensitive sensors. PMID:22778630

  18. Le Point sur... Astronomie IV

    NASA Astrophysics Data System (ADS)

    Pecker, J.-C.

    Cet ouvrage regroupe des articles de mise au point sollicités par le rédacteur en chef de la rubrique Astronomie des Comptes rendus de l'Académie des sciences. Les textes se proposent de faire découvrir aux lecteurs, dans les principales disciplines de l'astronomie, les résultats les plus remarquables des dernières années.Leurs auteurs sont des spécialistes participant activement à l'accroissement des connaissances dans des domaines faisant l'objet de recherches intensives. Ces mises au point sur des questions particulièrement importantes de l'astronomie sont rédigées soit en français, soit en anglais et accompagnées d'une bibliographie détaillée.

  19. Sensing with superconducting point contacts.

    PubMed

    Nurbawono, Argo; Zhang, Chun

    2012-01-01

    Superconducting point contacts have been used for measuring magnetic polarizations, identifying magnetic impurities, electronic structures, and even the vibrational modes of small molecules. Due to intrinsically small energy scale in the subgap structures of the supercurrent determined by the size of the superconducting energy gap, superconductors provide ultrahigh sensitivities for high resolution spectroscopies. The so-called Andreev reflection process between normal metal and superconductor carries complex and rich information which can be utilized as powerful sensor when fully exploited. In this review, we would discuss recent experimental and theoretical developments in the supercurrent transport through superconducting point contacts and their relevance to sensing applications, and we would highlight their current issues and potentials. A true utilization of the method based on Andreev reflection analysis opens up possibilities for a new class of ultrasensitive sensors.

  20. Leverage points for sustainability transformation.

    PubMed

    Abson, David J; Fischer, Joern; Leventon, Julia; Newig, Jens; Schomerus, Thomas; Vilsmaier, Ulli; von Wehrden, Henrik; Abernethy, Paivi; Ives, Christopher D; Jager, Nicolas W; Lang, Daniel J

    2017-02-01

    Despite substantial focus on sustainability issues in both science and politics, humanity remains on largely unsustainable development trajectories. Partly, this is due to the failure of sustainability science to engage with the root causes of unsustainability. Drawing on ideas by Donella Meadows, we argue that many sustainability interventions target highly tangible, but essentially weak, leverage points (i.e. using interventions that are easy, but have limited potential for transformational change). Thus, there is an urgent need to focus on less obvious but potentially far more powerful areas of intervention. We propose a research agenda inspired by systems thinking that focuses on transformational 'sustainability interventions', centred on three realms of leverage: reconnecting people to nature, restructuring institutions and rethinking how knowledge is created and used in pursuit of sustainability. The notion of leverage points has the potential to act as a boundary object for genuinely transformational sustainability science.

  1. Point contacts in encapsulated graphene

    SciTech Connect

    Handschin, Clevin; Fülöp, Bálint; Csonka, Szabolcs; Makk, Péter; Blanter, Sofya; Weiss, Markus; Schönenberger, Christian; Watanabe, Kenji; Taniguchi, Takashi

    2015-11-02

    We present a method to establish inner point contacts with dimensions as small as 100 nm on hexagonal boron nitride (hBN) encapsulated graphene heterostructures by pre-patterning the top-hBN in a separate step prior to dry-stacking. 2- and 4-terminal field effect measurements between different lead combinations are in qualitative agreement with an electrostatic model assuming point-like contacts. The measured contact resistances are 0.5–1.5 kΩ per contact, which is quite low for such small contacts. By applying a perpendicular magnetic field, an insulating behaviour in the quantum Hall regime was observed, as expected for inner contacts. The fabricated contacts are compatible with high mobility graphene structures and open up the field for the realization of several electron optical proposals.

  2. Turning points in reactor design

    SciTech Connect

    Beckjord, E.S.

    1995-09-01

    This article provides some historical aspects on nuclear reactor design, beginning with PWR development for Naval Propulsion and the first commercial application at Yankee Rowe. Five turning points in reactor design and some safety problems associated with them are reviewed: (1) stability of Dresden-1, (2) ECCS, (3) PRA, (4) TMI-2, and (5) advanced passive LWR designs. While the emphasis is on the thermal-hydraulic aspects, the discussion is also about reactor systems.

  3. Viviani Polytopes and Fermat Points

    ERIC Educational Resources Information Center

    Zhou, Li

    2012-01-01

    Given a set of oriented hyperplanes P = {p1, . . . , pk} in R[superscript n], define v : R[superscript n] [right arrow] R by v(X) = the sum of the signed distances from X to p[subscript 1], . . . , p[subscript k], for any point X [is a member of] R[superscript n]. We give a simple geometric characterization of P for which v is constant, leading to…

  4. Interpretation of human pointing by African elephants: generalisation and rationality.

    PubMed

    Smet, Anna F; Byrne, Richard W

    2014-11-01

    Factors influencing the abilities of different animals to use cooperative social cues from humans are still unclear, in spite of long-standing interest in the topic. One of the few species that have been found successful at using human pointing is the African elephant (Loxodonta africana); despite few opportunities for learning about pointing, elephants follow a pointing gesture in an object-choice task, even when the pointing signal and experimenter's body position are in conflict, and when the gesture itself is visually subtle. Here, we show that the success of captive African elephants at using human pointing is not restricted to situations where the pointing signal is sustained until the time of choice: elephants followed human pointing even when the pointing gesture was withdrawn before they had responded to it. Furthermore, elephants rapidly generalised their response to a type of social cue they were unlikely to have seen before: pointing with the foot. However, unlike young children, they showed no sign of evaluating the 'rationality' of this novel pointing gesture according to its visual context: that is, whether the experimenter's hands were occupied or not.

  5. Active point out-of-plane ultrasound calibration

    NASA Astrophysics Data System (ADS)

    Cheng, Alexis; Guo, Xiaoyu; Zhang, Haichong K.; Kang, Hyunjae; Etienne-Cummings, Ralph; Boctor, Emad M.

    2015-03-01

    Image-guided surgery systems are often used to provide surgeons with informational support. Due to several unique advantages such as ease of use, real-time image acquisition, and no ionizing radiation, ultrasound is a common intraoperative medical imaging modality used in image-guided surgery systems. To perform advanced forms of guidance with ultrasound, such as virtual image overlays or automated robotic actuation, an ultrasound calibration process must be performed. This process recovers the rigid body transformation between a tracked marker attached to the transducer and the ultrasound image. Point-based phantoms are considered to be accurate, but their calibration framework assumes that the point is in the image plane. In this work, we present the use of an active point phantom and a calibration framework that accounts for the elevational uncertainty of the point. Given the lateral and axial position of the point in the ultrasound image, we approximate a circle in the axial-elevational plane with a radius equal to the axial position. The standard approach transforms all of the imaged points to be a single physical point. In our approach, we minimize the distances between the circular subsets of each image, with them ideally intersecting at a single point. We simulated in noiseless and noisy cases, presenting results on out-of-plane estimation errors, calibration estimation errors, and point reconstruction precision. We also performed an experiment using a robot arm as the tracker, resulting in a point reconstruction precision of 0.64mm.

  6. Saddle point of attachment in jet-crossflow interaction

    NASA Astrophysics Data System (ADS)

    Zhang, Chenxing; Shi, Junxiang; Ke, Zhaoqing; Chen, Chung-Lung

    2017-03-01

    Numerical simulation and theoretical analysis were performed to investigate the upstream topology of a jet-crossflow interaction. The numerical results were validated with mathematical theory as well as a juncture flow structure. The upstream critical point satisfies the condition of occurrence for a saddle point of attachment in the horseshoe vortex system. In addition to the classical topology led by a saddle point of separation, a new topology led by a saddle point of attachment was found for the first time in a jet-crossflow interaction. The degeneration of the critical point from separation to attachment is determined by the velocity ratio of the jet over the crossflow, and the boundary layer thickness of the flat plate. When the boundary layer thickness at the upstream edge of the jet is close to one diameter of the jet, the flow topology is led by a saddle point of attachment. Variation of the velocity ratio does not change the topology but the location of the saddle point. When the boundary layer thickness is less than 0.255 of the jet flow diameter, large velocity ratio can generate a saddle point of attachment without spiral horseshoe vortex; continuously decreasing the velocity ratio will change the flow topology to saddle point of the separation. The degeneration of the critical point from attachment to separation was observed.

  7. Point discharge current measurements beneath dust devils

    NASA Astrophysics Data System (ADS)

    Lorenz, Ralph D.; Neakrase, Lynn D. V.; Anderson, John P.; Harrison, R. Giles; Nicoll, Keri A.

    2016-12-01

    We document for the first time observations of point discharge currents under dust devils using a novel compact sensor deployed in summer 2016 at the USDA-ARS Jornada Experimental Range in New Mexico, USA. A consistent signature is noted in about a dozen events seen over 40 days, with a positive current ramping up towards closest approach, switching to a decaying negative current as the devil recedes. The currents, induced on a small wire about 10 cm above the ground, correlate with dust devil intensity (pressure drop) and dust loading, and reached several hundred picoAmps.

  8. The Critical Point Facility (CPF)

    NASA Technical Reports Server (NTRS)

    1992-01-01

    The Critical Point Facility (CPF) is an ESA multiuser facility designed for microgravity research onboard Spacelab. It has been conceived and built to offer investigators opportunities to conduct research on critical point phenomena in microgravity. This facility provides the high precision and stability temperature standards required in this field of research. It has been primarily designed for the purpose of optical investigations of transparent fluids. During a Spacelab mission, the CPF automatically processes several thermostats sequentially, each thermostat corresponding to an experiment. The CPF is now integrated in Spacelab at Kennedy Space Center, in preparation for the International Microgravity Lab. mission. The CPF was designed to submit transparent fluids to an adequate, user defined thermal scenario, and to monitor their behavior by using thermal and optical means. Because they are strongly affected by gravity, a good understanding of critical phenomena in fluids can only be gained in low gravity conditions. Fluids at the critical point become compressed under their own weight. The role played by gravity in the formation of interfaces between distinct phases is not clearly understood.

  9. 51. LINES AT TIME OFFICE NO. 13 AT CHECKOUT TIME. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    51. LINES AT TIME OFFICE NO. 13 AT CHECKOUT TIME. SEAPLANE HANGARS (BLDGS. 1-2) IN BACKGROUND. USN PHOTO, JULY 11, 1941. - Quonset Point Naval Air Station, Roger Williams Way, North Kingstown, Washington County, RI

  10. Implementation of Fast-ICA: A Performance Based Comparison Between Floating Point and Fixed Point DSP Platform

    NASA Astrophysics Data System (ADS)

    Patil, Dinesh; Das, Niva; Routray, Aurobinda

    2011-01-01

    The main focus of the paper is to bring out the differences in performance related issues of Fast-ICA algorithm associated with floating point and fixed point digital signal processing (DSP) platforms. The DSP platforms consisting of TMS320C6713 floating point processor and TMS320C6416 fixed point processor from Texas Instruments have been chosen for this purpose. To study the consistency of performance, the algorithm has been subjected to three different test cases comprising of a mixture of synthetic signals, a mixture of speech signals and a mixture of synthetic signals in presence of noise, respectively. The performance of the Fast-ICA algorithm on floating point and fixed point platform are compared on the basis of accuracy of separation and execution time. Experimental results show insignificant differences in the accuracy of separation and execution time obtained from fixed point processor when compared with those obtained from floating point processor. This clearly strengthens the feasibility issue concerning hardware realization of Fast-ICA on fixed point platform for specific applications.

  11. Risley prism universal pointing system (RPUPS)

    NASA Astrophysics Data System (ADS)

    Dixon, John; Engel, James R.; Vaillancourt, Robert; Schwarze, Craig; Potter, Kevin

    2015-09-01

    OPTRA is currently developing a Risley Prism Universal Pointing System (RPUPS): a highly customizable cued beamsteering system. The RPUPS consists of a visible or infrared cueing imager co-aligned with an optical beam steering system's pointing-field-of-regard. The cueing imager is used to identify a region-of-interest within its wide field-of-view, via a wireless tablet device. The tablet user can choose to manually or automatically, identify and track regions-of-interest. The optical beam steering system uses a matched pair of Risley Prisms to direct an interrogating optical system's instantaneous-field-of-view onto the identified region-of-interest. The tablet updates the user with real time information from both the cueing imager and the interrogating optical system. Risley prism material and geometry choices provide operating wavelength, aperture size, and field-of-regard flexibility for this front-end pointing component. Back-end components may be receive-only, transmit-only, or transmit/receive combinations. The flexibility of the RPUPS allows for mission specific customization where applications include but are not limited to: synthetic foveated imaging, spectroscopic probes and laser (LIDAR) ranging and tracking. This paper will focus on the design and anticipated applications of the RPUPS.

  12. SOFIA pointing and chopping: performance and prospect

    NASA Astrophysics Data System (ADS)

    Reinacher, Andreas; Lammen, Yannick; Graf, Friederike; Jakob, Holger

    2016-09-01

    The Stratospheric Observatory for Infrared Astronomy (SOFIA) is a 2.5m infrared telescope built into a Boeing 747 SP. In 2014 SOFIA reached its Full Operational Capability milestone and nowadays takes off about three times a week to observe the infrared sky from altitudes above most of the atmosphere's water vapor content. Despite reaching this major milestone the work to improve the observatory's performance is continuing in many areas. This paper focuses on the telescope's current pointing and chopping performance and gives an overview over the ongoing and foreseen work to further improve in those two areas. Pointing performance as measured with the fast focal plane camera in flight is presented and based on that data it is elaborated how and in which frequency bands a further reduction of image jitter might be achieved. One contributor to the remaining jitter as well as the major actuator to reduce jitter with frequencies greater than 5 Hz is SOFIA's Secondary Mirror Assembly (SMA) or Chopper. As-is SMA jitter and chopping performance data as measured in flight is presented as well as recent improvements to the position sensor cabling and calibration and their effect on the SMA's pointing accuracy. Furthermore a brief description of a laboratory mockup of the SMA is given and the intended use of this mockup to test major hardware changes for further performance improvement is explained.

  13. High speed point derivative microseismic detector

    DOEpatents

    Uhl, James Eugene; Warpinski, Norman Raymond; Whetten, Ernest Blayne

    1998-01-01

    A high speed microseismic event detector constructed in accordance with the present invention uses a point derivative comb to quickly and accurately detect microseismic events. Compressional and shear waves impinging upon microseismic receiver stations disposed to collect waves are converted into digital data and analyzed using a point derivative comb including assurance of quiet periods prior to declaration of microseismic events. If a sufficient number of quiet periods have passed, the square of a two point derivative of the incoming digital signal is compared to a trip level threshold exceeding the determined noise level to declare a valid trial event. The squaring of the derivative emphasizes the differences between noise and signal, and the valid event is preferably declared when the trip threshold has been exceeded over a temporal comb width to realize a comb over a given time period. Once a trial event has been declared, the event is verified through a spatial comb, which applies the temporal event comb to additional stations. The detector according to the present invention quickly and accurately detects initial compressional waves indicative of a microseismic event which typically exceed the ambient cultural noise level by a small amount, and distinguishes the waves from subsequent larger amplitude shear waves.

  14. High speed point derivative microseismic detector

    DOEpatents

    Uhl, J.E.; Warpinski, N.R.; Whetten, E.B.

    1998-06-30

    A high speed microseismic event detector constructed in accordance with the present invention uses a point derivative comb to quickly and accurately detect microseismic events. Compressional and shear waves impinging upon microseismic receiver stations disposed to collect waves are converted into digital data and analyzed using a point derivative comb including assurance of quiet periods prior to declaration of microseismic events. If a sufficient number of quiet periods have passed, the square of a two point derivative of the incoming digital signal is compared to a trip level threshold exceeding the determined noise level to declare a valid trial event. The squaring of the derivative emphasizes the differences between noise and signal, and the valid event is preferably declared when the trip threshold has been exceeded over a temporal comb width to realize a comb over a given time period. Once a trial event has been declared, the event is verified through a spatial comb, which applies the temporal event comb to additional stations. The detector according to the present invention quickly and accurately detects initial compressional waves indicative of a microseismic event which typically exceed the ambient cultural noise level by a small amount, and distinguishes the waves from subsequent larger amplitude shear waves. 9 figs.

  15. SAMPEX science pointing with velocity avoidance

    NASA Astrophysics Data System (ADS)

    Frakes, Joseph P.; Henretty, Debra A.; Flatley, Thomas W.; Markley, F. L.; San, Josephine K.; Lightsey, E. G.

    The Solar, Anomalous, and Magnetospheric Particle Explorer (SAMPEX) science pointing mode is presented with the additional constraint of velocity avoidance. This constraint has been added in light of the orbital debris and micrometeoroid fluxes that have been revealed by the Long Duration Exposure Facility (LDEF) recovered in January 1990. These fluxes are 50-100 times higher than the flux tables that were used in the September 1988 proposal to NASA for the SAMPEX mission. The SAMPEX Heavey Ion Large Telescope (HILT) sensor includes a flow-through isobutane proportional counter that is susceptible to penetration by orbital debris and micrometeoroids. Thus, keeping the HILT sensor pointed away from the velocity vector, the direction of maximum flux, will compensate for the higher than expected fluxes. Using an orbital debris model and a micrometeoroid model developed at the Johnson Space Center (JSC), and a SAMPEX dynamic simulator developed by the Guidance and Control Branch at the Goddard Space Flight Center (GSFC), an 'optimal' minimum ram angle (the angle between the HILT boresight and the velocity vector) of 90 degrees has been determined. It is optimal in the sense of minimizing the science pointing performance degradation while providing approximately an 89 percent chance of survival for the HILT sensor over a three year period.

  16. 47 CFR 90.467 - Dispatch points.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 5 2011-10-01 2011-10-01 false Dispatch points. 90.467 Section 90.467... MOBILE RADIO SERVICES Transmitter Control § 90.467 Dispatch points. Dispatch points meeting the... radio station operated from a dispatch point or points shall assume full responsibility for the use...

  17. 47 CFR 90.467 - Dispatch points.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 5 2014-10-01 2014-10-01 false Dispatch points. 90.467 Section 90.467... MOBILE RADIO SERVICES Transmitter Control § 90.467 Dispatch points. Dispatch points meeting the... radio station operated from a dispatch point or points shall assume full responsibility for the use...

  18. 47 CFR 90.467 - Dispatch points.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 5 2013-10-01 2013-10-01 false Dispatch points. 90.467 Section 90.467... MOBILE RADIO SERVICES Transmitter Control § 90.467 Dispatch points. Dispatch points meeting the... radio station operated from a dispatch point or points shall assume full responsibility for the use...

  19. 47 CFR 90.467 - Dispatch points.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 5 2012-10-01 2012-10-01 false Dispatch points. 90.467 Section 90.467... MOBILE RADIO SERVICES Transmitter Control § 90.467 Dispatch points. Dispatch points meeting the... radio station operated from a dispatch point or points shall assume full responsibility for the use...

  20. 47 CFR 90.467 - Dispatch points.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Dispatch points. 90.467 Section 90.467... MOBILE RADIO SERVICES Transmitter Control § 90.467 Dispatch points. Dispatch points meeting the... radio station operated from a dispatch point or points shall assume full responsibility for the use...