Single-Event Effects Ground Testing and On-Orbit Rate Prediction Methods: The Past, Present and Future

NASA Technical Reports Server (NTRS)

Reed, Robert A.; Kinnison, Jim; Pickel, Jim; Buchner, Stephen; Marshall, Paul W.; Kniffin, Scott; LaBel, Kenneth A.

2003-01-01

Over the past 27 years, or so, increased concern over single event effects in spacecraft systems has resulted in research, development and engineering activities centered around a better understanding of the space radiation environment, single event effects predictive methods, ground test protocols, and test facility developments. This research has led to fairly well developed methods for assessing the impact of the space radiation environment on systems that contain SEE sensitive devices and the development of mitigation strategies either at the system or device level.

Performance of the High-Energy Single-Event Effects Test Facility (SEETF) at Michigan State University's National Superconducting Cyclotron Laboratory (NSCL)

NASA Technical Reports Server (NTRS)

Ladbury, R.; Reed, R. A.; Marshall, P. W.; LaBel, K. A.; Anantaraman, R.; Fox, R.; Sanderson, D. P.; Stolz, A.; Yurkon, J.; Zeller, A. F.;

Test Standard Revision Update: JESD57, "Procedures for the Measurement of Single-Event Effects in Semiconductor Devices from Heavy-Ion Irradiation"

NASA Technical Reports Server (NTRS)

Lauenstein, Jean-Marie

2015-01-01

The JEDEC JESD57 test standard, Procedures for the Measurement of Single-Event Effects in Semiconductor Devices from Heavy-Ion Irradiation, is undergoing its first revision since 1996. In this talk, we place this test standard into context with other relevant radiation test standards to show its importance for single-event effect radiation testing for space applications. We show the range of industry, government, and end-user party involvement in the revision. Finally, we highlight some of the key changes being made and discuss the trade-space in which setting standards must be made to be both useful and broadly adopted.

Heavy Ion Irradiation Fluence Dependence for Single-Event Upsets in a NAND Flash Memory

NASA Technical Reports Server (NTRS)

Chen, Dakai; Wilcox, Edward; Ladbury, Raymond L.; Kim, Hak; Phan, Anthony; Seidleck, Christina; Label, Kenneth

2016-01-01

We investigated the single-event effect (SEE) susceptibility of the Micron 16 nm NAND flash, and found that the single-event upset (SEU) cross section varied inversely with cumulative fluence. We attribute the effect to the variable upset sensitivities of the memory cells. Furthermore, the effect impacts only single cell upsets in general. The rate of multiple-bit upsets remained relatively constant with fluence. The current test standards and procedures assume that SEU follow a Poisson process and do not take into account the variability in the error rate with fluence. Therefore, traditional SEE testing techniques may underestimate the on-orbit event rate for a device with variable upset sensitivity.

Single event upset suspectibility testing of the Xilinx Virtex II FPGA

NASA Technical Reports Server (NTRS)

Carmichael, C.; Swift, C.; Yui, G.

2002-01-01

Heavy ion testing of the Xilinx Virtex II was conducted on the configuration, block RAM and user flip flop cells to determine their static single-event upset susceptibility using LETs of 1.2 to 60 MeVcm^2/mg. A software program specifically designed to count errors in the FPGA was used to reveal L1/e, values (the LET at which the cross section is l/e times the saturation cross-section) and single-event functional-interrupt failures.

NASA Electronic Parts and Packaging Field Programmable Gate Array Single Event Effects Test Guideline Update

NASA Technical Reports Server (NTRS)

Berg, Melanie D.; LaBel, Kenneth A.

2018-01-01

The following are updated or new subjects added to the FPGA SEE Test Guidelines manual: academic versus mission specific device evaluation, single event latch-up (SEL) test and analysis, SEE response visibility enhancement during radiation testing, mitigation evaluation (embedded and user-implemented), unreliable design and its affects to SEE Data, testing flushable architectures versus non-flushable architectures, intellectual property core (IP Core) test and evaluation (addresses embedded and user-inserted), heavy-ion energy and linear energy transfer (LET) selection, proton versus heavy-ion testing, fault injection, mean fluence to failure analysis, and mission specific system-level single event upset (SEU) response prediction. Most sections within the guidelines manual provide information regarding best practices for test structure and test system development. The scope of this manual addresses academic versus mission specific device evaluation and visibility enhancement in IP Core testing.

NASA Electronic Parts and Packaging (NEPP) Field Programmable Gate Array (FPGA) Single Event Effects (SEE) Test Guideline Update

NASA Technical Reports Server (NTRS)

Berg, Melanie D.; LaBel, Kenneth A.

2018-01-01

The following are updated or new subjects added to the FPGA SEE Test Guidelines manual: academic versus mission specific device evaluation, single event latch-up (SEL) test and analysis, SEE response visibility enhancement during radiation testing, mitigation evaluation (embedded and user-implemented), unreliable design and its affects to SEE Data, testing flushable architectures versus non-flushable architectures, intellectual property core (IP Core) test and evaluation (addresses embedded and user-inserted), heavy-ion energy and linear energy transfer (LET) selection, proton versus heavy-ion testing, fault injection, mean fluence to failure analysis, and mission specific system-level single event upset (SEU) response prediction. Most sections within the guidelines manual provide information regarding best practices for test structure and test system development. The scope of this manual addresses academic versus mission specific device evaluation and visibility enhancement in IP Core testing.

Compendium of Single-Event Latchup and Total Ionizing Dose Test Results of Commercial Analog to Digital Converters

NASA Technical Reports Server (NTRS)

Irom, Farokh; Agarwal, Shri G.

2012-01-01

This paper reports single-event latchup and total dose results for a variety of analog to digital converters targeted for possible use in NASA spacecraft's. The compendium covers devices tested over the last 15 years.

Single Event Effects in FPGA Devices 2015-2016

NASA Technical Reports Server (NTRS)

Berg, Melanie; LaBel, Kenneth; Pellish, Jonathan

2016-01-01

This presentation provides an overview of single event effects in FPGA devices 2015-2016 including commercial Xilinx V5 heavy ion accelerated testing, Xilinx Kintex-7 heavy ion accelerated testing. Mitigation study, and investigation of various types of triple modular redundancy (TMR) for commercial SRAM based FPGAs.

Single Event Effects in FPGA Devices 2014-2015

NASA Technical Reports Server (NTRS)

Berg, Melanie D.; LaBel, Kenneth A.; Pellish, Jonathan

2015-01-01

This presentation provides an overview of single event effects in FPGA devices 2014-2015 including commercial Xilinx V5 heavy ion accelerated testing, Xilinx Kintex-7 heavy ion accelerated testing. Mitigation study, and investigation of various types of triple modular redundancy (TMR) for commercial SRAM based FPGAs.

Single Event Effects in FPGA Devices 2015-2016

NASA Technical Reports Server (NTRS)

Berg, Melanie; LaBel, Kenneth; Pellish, Jonathan

2016-01-01

This presentation provides an overview of single event effects in FPGA devices 2015-2016 including commercial Xilinx V5 heavy ion accelerated testing, Xilinx Kintex-7 heavy ion accelerated testing, mitigation study, and investigation of various types of triple modular redundancy (TMR) for commercial SRAM based FPGAs.

Compendium of Single Event Effects Test Results for Commercial Off-The-Shelf and Standard Electronics for Low Earth Orbit and Deep Space Applications

NASA Technical Reports Server (NTRS)

Reddell, Brandon D.; Bailey, Charles R.; Nguyen, Kyson V.; O'Neill, Patrick M.; Wheeler, Scott; Gaza, Razvan; Cooper, Jaime; Kalb, Theodore; Patel, Chirag; Beach, Elden R.;

Criticality of Low-Energy Protons in Single-Event Effects Testing of Highly-Scaled Technologies

NASA Technical Reports Server (NTRS)

Pellish, Jonathan A.; Marshall, Paul W.; Rodbell, Kenneth P.; Gordon, Michael S.; LaBel, Kenneth A.; Schwank, James R.; Dodds, Nathaniel A.; Castaneda, Carlos M.; Berg, Melanie D.; Kim, Hak S.;

Investigation of the Semicoa 2N7616 and 2N7425 and the Microsemi 2N7480 for Single-Event Gate Rupture and Single-Event Burnout

NASA Technical Reports Server (NTRS)

Scheick, Leif

2014-01-01

Single-event-effect test results for hi-rel total-dose-hardened power MOSFETs are presented in this report. The 2N7616 and the 2N7425 from Semicoa and the 2N7480 from International Rectifier were tested to NASA test condition standards and requirements. The 2N7480 performed well and the data agree with the manufacture's data. The 2N7616 and 2N7425 were entry parts from Semicoa using a new device architecture. Unfortunately, the device performed poorly and Semicoa is withdrawing power MOSFETs from it line due to these data. Vertical metal-oxide-semiconductor field-effect transistors (MOSFETs) are the most commonly used power transistor. MOSFETs are typically employed in power supplies and high current switching applications. Due to the inherent high electric fields in the device, power MOSFETs are sensitive to heavy ion irradiation and can fail catastrophically as a result of single-event gate rupture (SEGR) or single-event burnout (SEB). Manufacturers have designed radiation-hardened power MOSFETs for space applications. See [1] through [5] for more information. The objective of this effort was to investigate the SEGR and SEB responses of two power MOSFETs recently produced. These tests will serve as a limited verification of these parts. It is acknowledged that further testing on the respective parts may be needed for some mission profiles.

Characteristics of Single-Event Upsets in a Fabric Switch (ADS151)

NASA Technical Reports Server (NTRS)

Buchner, Stephen; Carts, Martin A.; McMorrow, Dale; Kim, Hak; Marshall, Paul W.; LaBel, Kenneth A.

2003-01-01

Abstract-Two types of single event effects - bit errors and single event functional interrupts - were observed during heavy-ion testing of the AD8151 crosspoint switch. Bit errors occurred in bursts with the average number of bits in a burst being dependent on both the ion LET and on the data rate. A pulsed laser was used to identify the locations on the chip where the bit errors and single event functional interrupts occurred. Bit errors originated in the switches, drivers, and output buffers. Single event functional interrupts occurred when the laser was focused on the second rank latch containing the data specifying the state of each switch in the 33x17 matrix.

Virtex-II Pro SEE Test Methods and Results

NASA Technical Reports Server (NTRS)

Petrick, David; Powell, Wesley; Howard, James W., Jr.; LaBel, Kenneth A.

2004-01-01

The objective of this coarse Single Event Effect (SEE) test is to determine the suitability of the commercial Virtex-II Pro family for use in spaceflight applications. To this end, this test is primarily intended to determine any Singe Event Latchup (SEL) susceptibilities for these devices. Secondly, this test is intended to measure the level of Single Event Upset (SEU) susceptibilities and in a general sense where they occur. The coarse SEE test was performed on a commercial XC2VP7 device, a relatively small single processor version of the Virtex-II Pro. As the XC2VP7 shares the same functional block design and fabrication process with the larger Virtex-II Pro devices, the results of this test should also be applicable to the larger devices. The XC2VP7 device was tested on a commercial Virtex-II Pro development board. The testing was performed at the Cyclotron laboratories at Texas A&M and Michigan State Universities using ions of varying energy levels and fluences.

Decline in Radiation Hardened Microcircuit Infrastructure

NASA Technical Reports Server (NTRS)

LaBel, Kenneth A.

2015-01-01

Two areas of radiation hardened microcircuit infrastructure will be discussed: 1) The availability and performance of radiation hardened microcircuits, and, and 2) The access to radiation test facilities primarily for proton single event effects (SEE) testing. Other areas not discussed, but are a concern include: The challenge for maintaining radiation effects tool access for assurance purposes, and, the access to radiation test facilities primarily for heavy ion single event effects (SEE) testing. Status and implications will be discussed for each area.

Laser Scanner Tests For Single-Event Upsets

NASA Technical Reports Server (NTRS)

Kim, Quiesup; Soli, George A.; Schwartz, Harvey R.

1992-01-01

Microelectronic advanced laser scanner (MEALS) is opto/electro/mechanical apparatus for nondestructive testing of integrated memory circuits, logic circuits, and other microelectronic devices. Multipurpose diagnostic system used to determine ultrafast time response, leakage, latchup, and electrical overstress. Used to simulate some of effects of heavy ions accelerated to high energies to determine susceptibility of digital device to single-event upsets.

JESD57 Test Standard, Procedures for the Measurement of Single-Event Effects in Semiconductor Devices from Heavy-Ion Irradiation Revision Update

NASA Technical Reports Server (NTRS)

Lauenstein, Jean-Marie

2016-01-01

The JEDEC JESD57 test standard, Procedures for the Measurement of Single-Event Effects in Semiconductor Devices from Heavy-Ion Irradiation, is undergoing its first revision since 1996. This presentation will provide an overview of some of the key proposed updates to the document.

Observations of Single Event Failure in Power MOSFETS

NASA Technical Reports Server (NTRS)

Nichols, D.; McCarty, K.; Coss, J.

1994-01-01

The first compendium of single event test data for power MOSFETs provides failure thresholds from burnout or gate rupture for over 100 devices of eight manufacturers. Ordering the data has also provided some useful insights.

Destructive Single-Event Failures in Schottky Diodes

NASA Technical Reports Server (NTRS)

Casey, Megan C.; Lauenstein, Jean-Marie; Gigliuto, Robert A.; Wilcox, Edward P.; Phan, Anthony M.; Kim, Hak; Chen, Dakai; LaBel, Kenneth A.

2014-01-01

This presentation contains test results for destructive failures in DC-DC converters. We have shown that Schottky diodes are susceptible to destructive single-event effects. Future work will be completed to identify parameter that determines diode susceptibility.

Current Single Event Effects Results for Candidate Spacecraft Electronics for NASA

NASA Technical Reports Server (NTRS)

OBryan, Martha V.; Seidleck, Christina M.; Carts, Martin A.; LaBel, Kenneth A.; Marshall, Cheryl J.; Reed, Robert A.; Sanders, Anthony B.; Hawkins, Donald K.; Cox, Stephen R.; Kniffin, Scott D.

2004-01-01

We present data on the vulnerability of a variety of candidate spacecraft electronics to proton and heavy ion induced single event effects. Devices tested include digital, analog, linear bipolar, and hybrid devices, among others.

Single Event Effects Results for Candidate Spacecraft Electronics for NASA

NASA Technical Reports Server (NTRS)

O'Bryan, Martha; LaBel, Kenneth A.; Kniffin, Scott D.; Howard, James W., Jr.; Poivey, Christian; Ladbury, Ray L.; Buchner, Stephen P.; Xapsos, Michael; Reed, Robert A.; Sanders, Anthony B.

2003-01-01

We present data on the vulnerability of a variety of candidate spacecraft electronics to proton and heavy ion induced single event effects. Devices tested include digital, analog, linear bipolar, and hybrid devices, among others.

Single-Event Transient Testing of the Crane Aerospace and Electronics SMHF2812D Dual DC-DC Converter

NASA Technical Reports Server (NTRS)

Casey, Megan

2015-01-01

The purpose of this testing was to characterize the Crane Aerospace & Electronics (Crane) Interpoint SMHF2812D for single-event transient (SET) susceptibility. These data shall be used for flight lot evaluation, as well as qualification by similarity of the SMHF family of converters, all of which use the same active components.

Radiation Tests on 2Gb NAND Flash Memories

NASA Technical Reports Server (NTRS)

Nguyen, Duc N.; Guertin, Steven M.; Patterson, J. D.

2006-01-01

We report on SEE and TID tests of highly scaled Samsung 2Gbits flash memories. Both in-situ and biased interval irradiations were used to characterize the response of the total accumulated dose failures. The radiation-induced failures can be categorized as followings: single event upset (SEU) read errors in biased and unbiased modes, write errors, and single-event-functional-interrupt (SEFI) failures.

Update on parts SEE suspectibility from heavy ions. [Single Event Effects

NASA Technical Reports Server (NTRS)

Nichols, D. K.; Smith, L. S.; Schwartz, H. R.; Soli, G.; Watson, K.; Koga, R.; Crain, W. R.; Crawford, K. B.; Hansel, S. J.; Lau, D. D.

1991-01-01

JPL and the Aerospace Corporation have collected a fourth set of heavy ion single event effects (SEE) test data. Trends in SEE susceptibility (including soft errors and latchup) for state-of-the-art parts are displayed. All data are conveniently divided into two tables: one for MOS devices, and one for a shorter list of recently tested bipolar devices. In addition, a new table of data for latchup tests only (invariably CMOS processes) is given.

Reliability Assessment of GaN Power Switches

DTIC Science & Technology

2015-04-17

Possibilities for single event burnout testing were examined as well. Device simulation under the conditions of some of the testing was performed on...reverse-bias (HTRB) and single electron burnout (SEE) tests. 8. Refine test structures, circuits, and procedures, and, if possible, develop

Trends In Susceptibility To Single-Event Upset

NASA Technical Reports Server (NTRS)

Nichols, Donald K.; Price, William E.; Kolasinski, Wojciech A.; Koga, Rukotaro; Waskiewicz, Alvin E.; Pickel, James C.; Blandford, James T.

1989-01-01

Report provides nearly comprehensive body of data on single-event upsets due to irradiation by heavy ions. Combines new test data and previously published data from governmental and industrial laboratories. Clear trends emerge from data useful in predicting future performances of devices.

Characterization of Single-Event Burnout in Power MOSFET Using Backside Laser Testing

NASA Astrophysics Data System (ADS)

Miller, F.; Luu, A.; Prud'homme, F.; Poirot, P.; Gaillard, R.; Buard, N.; Carrire, T.

2006-12-01

This paper presents a new methodology based upon backside laser irradiations to characterize the sensitivity of power devices towards Single-Event Burnout. It is shown that this technique can be used to define the safe operating area

Single Event Transients in Low Voltage Dropout (LVDO) Voltage Regulators

NASA Technical Reports Server (NTRS)

LaBel, K.; Karsh, J.; Pursley, S.; Kleyner, I.; Katz, R.; Poivey, C.; Kim, H.; Seidleck, C.

2006-01-01

This viewgraph presentation reviews the use of Low Voltage Dropout (LVDO) Voltage Regulators in environments where heavy ion induced Single Event Transients are a concern to the designers.Included in the presentation are results of tests of voltage regulators.

Effects of cosmic rays on single event upsets

NASA Technical Reports Server (NTRS)

Venable, D. D.; Zajic, V.; Lowe, C. W.; Olidapupo, A.; Fogarty, T. N.

1989-01-01

Assistance was provided to the Brookhaven Single Event Upset (SEU) Test Facility. Computer codes were developed for fragmentation and secondary radiation affecting Very Large Scale Integration (VLSI) in space. A computer controlled CV (HP4192) test was developed for Terman analysis. Also developed were high speed parametric tests which are independent of operator judgment and a charge pumping technique for measurement of D(sub it) (E). The X-ray secondary effects, and parametric degradation as a function of dose rate were simulated. The SPICE simulation of static RAMs with various resistor filters was tested.

Single Event Effects Test Results for the Actel ProASIC Plus and Altera Stratix-II Field Programmable Gate Arrays

NASA Technical Reports Server (NTRS)

Allen, Gregory R.; Swift, Gary M.

2006-01-01

This work describes radiation testing of Actel's ProASIC Plus and Altera's Stratix-II FPGAs. The Actel Device Under Test (DUT) was a ProASIC Plus APA300-PQ208 nonvolatile, field reprogrammable device which is based on a 0.22micron flash-based LVCMOS technology. Limited investigation has taken place into flash based FPGA technologies, therefore this test served as a preliminary reference point for various SEE behaviors. The Altera DUT was a Stratix-II EP2S60F1020C4. Single Event Upset (SEU) and Single Event Latchup (SEL) were the focus of these studies. For the Actel, a latchup test was done at an effective LET of 75.0 MeV-sq cm/mg at room temperature, and no latchup was detected when irradiated to a total fluence of 1 x 10(exp 7) particles/sq cm. The Altera part was shown to latchup at room temperature.

Single event upset sensitivity of low power Schottky devices

NASA Technical Reports Server (NTRS)

Price, W. E.; Nichols, D. K.; Measel, P. R.; Wahlin, K. L.

1982-01-01

Data taken from tests involving heavy ions in the Berkeley 88 in. cyclotron being directed at low power Schottky barrier devices are reported. The tests also included trials in the Harvard cyclotron with 130 MeV protons, and at the U.C. Davis cyclotron using 56 MeV protons. The experiments were performed to study the single event upsets in MSI logic devices containing flip-flops. Results are presented of single-event upsets (SEU) causing functional degradation observed in post-exposure tests of six different devices. The effectiveness of the particles in producing SEUs in logic device functioning was found to be directly proportional to the proton energy. Shielding was determined to offer negligible protection from the particle bombardment. The results are considered significant for the design and fabrication of LS devices for space applications.

Functional Interrupts and Destructive Failures from Single Event Effect Testing of Point-Of-Load Devices

NASA Technical Reports Server (NTRS)

Chen, Dakai; Phan, Anthony; Kim, Hak; Swonger, James; Musil, Paul; LaBel, Kenneth

2013-01-01

We show examples of single event functional interrupt and destructive failure in modern POL devices. The increasing complexity and diversity of the design and process introduce hard SEE modes that are triggered by various mechanisms.

Complex Parts, Complex Data: Why You Need to Understand What Radiation Single Event Testing Data Does and Doesn't Show and the Implications Thereof

NASA Technical Reports Server (NTRS)

LaBel, Kenneth A.; Berg, Melanie D.

2015-01-01

Electronic parts (integrated circuits) have grown in complexity such that determining all failure modes and risks from single particle event testing is impossible. In this presentation, the authors will present why this is so and provide some realism on what this means. Its all about understanding actual risks and not making assumptions.

The Single Event Effect Characteristics of the 486-DX4 Microprocessor

NASA Technical Reports Server (NTRS)

Kouba, Coy; Choi, Gwan

1996-01-01

This research describes the development of an experimental radiation testing environment to investigate the single event effect (SEE) susceptibility of the 486-DX4 microprocessor. SEE effects are caused by radiation particles that disrupt the logic state of an operating semiconductor, and include single event upsets (SEU) and single event latchup (SEL). The relevance of this work can be applied directly to digital devices that are used in spaceflight computer systems. The 486-DX4 is a powerful commercial microprocessor that is currently under consideration for use in several spaceflight systems. As part of its selection process, it must be rigorously tested to determine its overall reliability in the space environment, including its radiation susceptibility. The goal of this research is to experimentally test and characterize the single event effects of the 486-DX4 microprocessor using a cyclotron facility as the fault-injection source. The test philosophy is to focus on the "operational susceptibility," by executing real software and monitoring for errors while the device is under irradiation. This research encompasses both experimental and analytical techniques, and yields a characterization of the 486-DX4's behavior for different operating modes. Additionally, the test methodology can accommodate a wide range of digital devices, such as microprocessors, microcontrollers, ASICS, and memory modules, for future testing. The goals were achieved by testing with three heavy-ion species to provide different linear energy transfer rates, and a total of six microprocessor parts were tested from two different vendors. A consistent set of error modes were identified that indicate the manner in which the errors were detected in the processor. The upset cross-section curves were calculated for each error mode, and the SEU threshold and saturation levels were identified for each processor. Results show a distinct difference in the upset rate for different configurations of the on-chip cache, as well as proving that one vendor is superior to the other in terms of latchup susceptibility. Results from this testing were also used to provide a mean-time-between-failure estimate of the 486-DX4 operating in the radiation environment for the International Space Station.

Single-event burnout of n-p-n bipolar-junction transistors in hybrid DC/DC converters

NASA Astrophysics Data System (ADS)

Warren, K.; Roth, D.; Kinnison, J.; Pappalardo, R.

2002-12-01

Single-event-induced failure of the Lambda Advanced Analog AMF2805S DC/DC Converter has been traced to burnout of an n-p-n transistor in the MOSFET drive stage. The failures were observed during testing while in inhibit mode only. Modifications to prevent burnout of the drive stage were successfully employed. A discussion of the failure mechanism and consequences for DC/DC converter testing are presented.

Discussions On Worst-Case Test Condition For Single Event Burnout

NASA Astrophysics Data System (ADS)

Liu, Sandra; Zafrani, Max; Sherman, Phillip

2011-10-01

This paper discusses the failure characteristics of single- event burnout (SEB) on power MOSFETs based on analyzing the quasi-stationary avalanche simulation curves. The analyses show the worst-case test condition for SEB would be using the ion that has the highest mass that would result in the highest transient current due to charge deposition and displacement damage. The analyses also show it is possible to build power MOSFETs that will not exhibit SEB even when tested with the heaviest ion, which have been verified by heavy ion test data on SEB sensitive and SEB immune devices.

A guideline for heavy ion radiation testing for Single Event Upset (SEU)

NASA Technical Reports Server (NTRS)

Nichols, D. K.; Price, W. E.; Malone, C.

1984-01-01

A guideline for heavy ion radiation testing for single event upset was prepared to assist new experimenters in preparing and directing tests. How to estimate parts vulnerability and select an irradiation facility is described. A broad brush description of JPL equipment is given, certain necessary pre-test procedures are outlined and the roles and testing guidelines for on-site test personnel are indicated. Detailed descriptions of equipment needed to interface with JPL test crew and equipment are not provided, nor does it meet the more generalized and broader requirements of a MIL-STD document. A detailed equipment description is available upon request, and a MIL-STD document is in the early stages of preparation.

Analyzing Test-As-You-Fly Single Event Upset (SEU) Responses using SEU Data, Classical Reliability Models, and Space Environment Data

NASA Technical Reports Server (NTRS)

Berg, Melanie; Label, Kenneth; Campola, Michael; Xapsos, Michael

2017-01-01

We propose a method for the application of single event upset (SEU) data towards the analysis of complex systems using transformed reliability models (from the time domain to the particle fluence domain) and space environment data.

Toward Joint Hypothesis-Tests Seismic Event Screening Analysis: Ms|mb and Event Depth

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

Anderson, Dale; Selby, Neil

2012-08-14

Well established theory can be used to combine single-phenomenology hypothesis tests into a multi-phenomenology event screening hypothesis test (Fisher's and Tippett's tests). Commonly used standard error in Ms:mb event screening hypothesis test is not fully consistent with physical basis. Improved standard error - Better agreement with physical basis, and correctly partitions error to include Model Error as a component of variance, correctly reduces station noise variance through network averaging. For 2009 DPRK test - Commonly used standard error 'rejects' H0 even with better scaling slope ({beta} = 1, Selby et al.), improved standard error 'fails to rejects' H0.

Heavy Ion Irradiation Fluence Dependence for Single-Event Upsets of NAND Flash Memory

NASA Technical Reports Server (NTRS)

Chen, Dakai; Wilcox, Edward; Ladbury, Raymond; Kim, Hak; Phan, Anthony; Seidleck, Christina; LaBel, Kenneth

2016-01-01

We investigated the single-event effect (SEE) susceptibility of the Micron 16 nm NAND flash, and found the single-event upset (SEU) cross section varied inversely with fluence. The SEU cross section decreased with increasing fluence. We attribute the effect to the variable upset sensitivities of the memory cells. The current test standards and procedures assume that SEU follow a Poisson process and do not take into account the variability in the error rate with fluence. Therefore, heavy ion irradiation of devices with variable upset sensitivity distribution using typical fluence levels may underestimate the cross section and on-orbit event rate.

Single-Event Effect Report for EPC Series eGaN FETs: Comparison of EPC1000 and EPC2000 Series Devices for Destructive SEE

NASA Technical Reports Server (NTRS)

Scheick, Leif

2014-01-01

Recent testing of the EPC1000 series eGaN FETs has shown sensitivity to Single Event Effects (SEE) that are destructive. These effects are most likely the failure of the very thin gate structure in HEMT architecture. EPC has recently changed the doping of the substrate to improve the performance and the SEE response. This testing compares the SEE response of both devices.

Compendium of Single Event Effects, Total Ionizing Dose, and Displacement Damage for Candidate Spacecraft Electronics for NASA

NASA Technical Reports Server (NTRS)

LaBel, Kenneth A.; O'Bryan, Martha V.; Chen, Dakai; Campola, Michael J.; Casey, Megan C.; Pellish, Jonathan A.; Lauenstein, Jean-Marie; Wilcox, Edward P.; Topper, Alyson D.; Ladbury, Raymond L.;

Re-Verification of the IRHN57133SE and IRHN57250SE for Single Event Gate Rupture and Single Event Burnout

NASA Technical Reports Server (NTRS)

Scheick, Leif

2010-01-01

The vertical metal oxide semiconductor field-effect transistor (MOSFET) is a widely used power transistor onboard a spacecraft. The MOSFET is typically employed in power supplies and high current switching applications. Due to the inherent high electric fields in the device, power MOSFETs are sensitive to heavy ion irradiation and can fail catastrophically as a result of single event gate rupture (SEGR) or single event burnout (SEB). Manufacturers have designed radiation-hardened power MOSFETs for space applications. These radiation hardened devices are not immune to SEGR or SEB but, rather, can exhibit them at a much more damaging ion than their non-radiation hardened counterparts. See [1] through [5] for more information.This effort was to investigate the SEGR and SEB responses of two power MOSFETs from IR(the IRHN57133SE and the IRHN57250SE) that have recently been produced on a new fabrication line. These tests will serve as a limited verification of these parts, but it is acknowledged that further testing on the respective parts may be needed for some mission profiles.

Case report of vasovagal syncope associated with single pulse transcranial magnetic stimulation in a healthy adult participant.

PubMed

Gillick, Bernadette T; Rich, Tonya; Chen, Mo; Meekins, Gregg D

2015-12-01

Non-invasive brain stimulation-related seizures or syncopal events are rare. However, we report on a syncopal event in a healthy female during a transcranial magnetic stimulation single-pulse testing session. A 47-year-old healthy female presented for a transcranial magnetic stimulation session involving single-pulse assessment of cortical excitability. During the session, the participant appeared to have a brief event involving fainting and myoclonic jerks of the upper extremities. Orthostatic assessment was performed after the event and physician evaluation determined that this was a vasovagal syncopal event. The ethical aspects of this neurophysiology testing protocol were reviewed by the University of Minnesota Institutional Review Board (IRB), and formal IRB approval was deemed unnecessary for single-pulse assessment of healthy control participants not directly involved in a research study. Informed consent was obtained by the participant, including review of potential adverse events. Although rare and rarely reported, vasovagal syncopal events surrounding non-invasive brain stimulation do occur. Thorough pre-screening should incorporate assessment of history of syncope and a plan for risk mitigation if such an event should occur. A complete assessment of the impact of stimulation on the autonomic nervous system is unknown. As such studies expand into patients with myriad neurologic diagnoses, further studies on this effect, in both healthy control and patient populations, are warranted. Such knowledge could contribute to identification of the optimal study participant, and improvements in techniques of stimulation administration.

Proton Single Event Effects (SEE) Testing of the Myrinet Crossbar Switch and Network Interface Card

NASA Technical Reports Server (NTRS)

Howard, James W., Jr.; LaBel, Kenneth A.; Carts, Martin A.; Stattel, Ronald; Irwin, Timothy L.; Day, John H. (Technical Monitor)

2002-01-01

As part of the Remote Exploration and Experimentation Project (REE), work was performed to do a proton SEE (Single Event Effect) evaluation of the Myricom network protocol system (Myrinet). This testing included the evaluation of the Myrinet crossbar switch and the Network Interface Card (NIC). To this end, two crossbar switch devices and five components in the NIC were exposed to the proton beam at the University of California at Davis Crocker Nuclear Laboratory (CNL).

Blind tests of methods for InSight Mars mission: Open scientific challenge

NASA Astrophysics Data System (ADS)

Clinton, John; Ceylan, Savas; Giardini, Domenico; Khan, Amir; van Driel, Martin; Böse, Maren; Euchner, Fabian; Garcia, Raphael F.; Drilleau, Mélanie; Lognonné, Philippe; Panning, Mark; Banerdt, Bruce

2017-04-01

The Marsquake Service (MQS) will be the ground segment service within the InSight mission to Mars, which will deploy a single seismic station on Elysium Planitia in November 2018. The main tasks of the MQS are the identification and characterisation of seismicity, and managing the Martian seismic event catalogue. In advance of the mission, we have developed a series of single station event location methods that rely on a priori 1D and 3D structural models. In coordination with the Mars Structural Service, we expect to use iterative inversion techniques to revise these structural models and event locations. In order to seek methodological advancements and test our current approaches, we have designed a blind test case using Martian synthetics combined with realistic noise models for the Martian surface. We invite all scientific parties that are interested in single station approaches and in exploring the Martian time-series to participate and contribute to our blind test. We anticipate the test will can improve currently developed location and structural inversion techniques, and also allow us explore new single station techniques for moment tensor and magnitude determination. The waveforms for our test case are computed employing AxiSEM and Instaseis for a randomly selected 1D background model and event catalogue that is statistically consistent with our current expectation of Martian seismicity. Realistic seismic surface noise is superimposed to generate a continuous time-series spanning 6 months. The event catalog includes impacts as well as Martian quakes. The temporal distribution of the seismicity in the timeseries, as well as the true structural model, are not be known to any participating parties including MQS till the end of competition. We provide our internal tools such as event location codes, suite of background models, seismic phase travel times, in order to support researchers who are willing to use/improve our current methods. Following the deadline of our blind test in late 2017, we plan to combine all outcomes in an article with all participants as co-authors.

Heavy ion induced Single Event Phenomena (SEP) data for semiconductor devices from engineering testing

NASA Technical Reports Server (NTRS)

Nichols, Donald K.; Huebner, Mark A.; Price, William E.; Smith, L. S.; Coss, James R.

1988-01-01

The accumulation of JPL data on Single Event Phenomena (SEP), from 1979 to August 1986, is presented in full report format. It is expected that every two years a supplement report will be issued for the follow-on period. This data for 135 devices expands on the abbreviated test data presented as part of Refs. (1) and (3) by including figures of Single Event Upset (SEU) cross sections as a function of beam Linear Energy Transfer (LET) when available. It also includes some of the data complied in the JPL computer in RADATA and the SPACERAD data bank. This volume encompasses bipolar and MOS (CMOS and MHNOS) device data as two broad categories for both upsets (bit-flips) and latchup. It also includes comments on less well known phenomena, such as transient upsets and permanent damage modes.

Recent Radiation Damage and Single Event Effect Results for Candidate Spacecraft Electronics

NASA Technical Reports Server (NTRS)

OBryan, Martha V.; LaBel, Kenneth A.; Reed, Robert A.; Ladbury, Ray L.; Howard, James W., Jr.; Buchner, Stephen P.; Barth, Janet L.; Kniffen, Scott D.; Seidleck, Christina M.; Marshall, Cheryl J.;

Current Single Event Effects and Radiation Damage Results for Candidate Spacecraft Electronics

NASA Technical Reports Server (NTRS)

OBryan, Martha V.; LaBel, Kenneth A.; Reed, Robert A.; Ladbury, Ray L.; Howard, James W., Jr.; Kniffin, Scott D.; Poivey, Christian; Buchner, Stephen P.; Bings, John P.; Titus, Jeff L.

2002-01-01

We present data on the vulnerability of a variety of candidate spacecraft electronics to proton and heavy ion induced single event effects, total ionizing dose and proton-induced damage. Devices tested include optoelectronics, digital, analog, linear bipolar, hybrid devices, Analog-to-Digital Converters (ADCs), Digital-to-Analog Converters (DACs), and DC-DC converters, among others.

Bevalac Ion Beam Characterizations for Single Event Phenomena

DTIC Science & Technology

1992-07-16

site. 13 REFERENCES 1. T. L. Criswell, P. R. Measel and K. L. Wablin, "Single Event Upset Testing with Relativistic Heavy Ions," IEEE Trans. Nucl. Sci...NS-31, 1559-1563, (1984). 2. T. L. Criswell, D. L. Oberg, J. L. Wert, P. R. Measel , and W. E. Wilson, "Measurement of SEU Thresholds and Cross

A Nuclear Interaction Model for Understanding Results of Single Event Testing with High Energy Protons

NASA Technical Reports Server (NTRS)

Culpepper, William X.; ONeill, Pat; Nicholson, Leonard L.

2000-01-01

An internuclear cascade and evaporation model has been adapted to estimate the LET spectrum generated during testing with 200 MeV protons. The model-generated heavy ion LET spectrum is compared to the heavy ion LET spectrum seen on orbit. This comparison is the basis for predicting single event failure rates from heavy ions using results from a single proton test. Of equal importance, this spectra comparison also establishes an estimate of the risk of encountering a failure mode on orbit that was not detected during proton testing. Verification of the general results of the model is presented based on experiments, individual part test results, and flight data. Acceptance of this model and its estimate of remaining risk opens the hardware verification philosophy to the consideration of radiation testing with high energy protons at the board and box level instead of the more standard method of individual part testing with low energy heavy ions.

Classifier for gravitational-wave inspiral signals in nonideal single-detector data

NASA Astrophysics Data System (ADS)

Kapadia, S. J.; Dent, T.; Dal Canton, T.

2017-11-01

We describe a multivariate classifier for candidate events in a templated search for gravitational-wave (GW) inspiral signals from neutron-star-black-hole (NS-BH) binaries, in data from ground-based detectors where sensitivity is limited by non-Gaussian noise transients. The standard signal-to-noise ratio (SNR) and chi-squared test for inspiral searches use only properties of a single matched filter at the time of an event; instead, we propose a classifier using features derived from a bank of inspiral templates around the time of each event, and also from a search using approximate sine-Gaussian templates. The classifier thus extracts additional information from strain data to discriminate inspiral signals from noise transients. We evaluate a random forest classifier on a set of single-detector events obtained from realistic simulated advanced LIGO data, using simulated NS-BH signals added to the data. The new classifier detects a factor of 1.5-2 more signals at low false positive rates as compared to the standard "reweighted SNR" statistic, and does not require the chi-squared test to be computed. Conversely, if only the SNR and chi-squared values of single-detector events are available, random forest classification performs nearly identically to the reweighted SNR.

Single Event Effect (SEE) Test Planning 101

NASA Technical Reports Server (NTRS)

LaBel, Kenneth A.; Pellish, Jonathan; Berg, Melanie D.

2011-01-01

This is a course on SEE Test Plan development. It is an introductory discussion of the items that go into planning an SEE test that should complement the SEE test methodology used. Material will only cover heavy ion SEE testing and not proton, LASER, or other though many of the discussed items may be applicable. While standards and guidelines for how-to perform single event effects (SEE) testing have existed almost since the first cyclotron testing, guidance on the development of SEE test plans has not been as easy to find. In this section of the short course, we attempt to rectify this lack. We consider the approach outlined here as a "living" document: mission specific constraints and new technology related issues always need to be taken into account. We note that we will use the term "test planning" in the context of those items being included in a test plan.

Using Cf-252 for single event upset testing

NASA Astrophysics Data System (ADS)

Howard, J. W.; Chen, R.; Block, R. C.; Becker, M.; Costantine, A. G.; Smith, L. S.; Soli, G. A.; Stauber, M. C.

An improved system using Cf-252 and associated nuclear instrumentation has been used to determine single event upset (SEU) cross section versus linear energy transfer (LET) curve for several static random access memory (SRAM) devices. Through the use of a thin-film scintillator, providing energy information on each fission fragment, individual SEU's and ion energy can be associated to calculate the cross section curves. Results are presented from tests of several SRAM's over the 17-43 MeV-cm squared/mg LET range. Values obtained for SEU cross sections and LET thresholds are in good agreement with the results from accelerator testing. The equipment is described, the theory of thin-film scintillation detector response is summarized, experimental procedures are reviewed, and the test results are discussed.

Single event effects in pulse width modulation controllers

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

Penzin, S.H.; Crain, W.R.; Crawford, K.B.

1996-12-01

SEE testing was performed on pulse width modulation (PWM) controllers which are commonly used in switching mode power supply systems. The devices are designed using both Set-Reset (SR) flip-flops and Toggle (T) flip-flops which are vulnerable to single event upset (SEU) in a radiation environment. Depending on the implementation of the different devices the effect can be significant in spaceflight hardware.

Proton Particle Test Fluence: What's the Right Number?

NASA Technical Reports Server (NTRS)

LaBel, Kenneth A.; Ladbury, Raymond

2015-01-01

While we have been utilizing standard fluence levels such as those listed in the JESD57 document, we have begun revisiting what an appropriate test fluence is when it comes to qualifying a device for single events. Instead of a fixed fluence level or until a specific number of events occurs, a different thought process is required.

Particle Test Fluence: What's the Right Number?

NASA Technical Reports Server (NTRS)

LaBel, Kenneth A.

2014-01-01

While we have been utilizing standard fluence levels such as those listed in the JESD57 document, we have begun revisiting what an appropriate test fluence is when it comes to qualifying a device for single events. Instead of a fixed fluence level or until a specific number of events occurs, a different thought process is required.

Interpreting Space-Mission LET Requirements for SEGR in Power MOSFETs

NASA Technical Reports Server (NTRS)

Lauenstein, J. M.; Ladbury, R. L.; Batchelor, D. A.; Goldsman, N.; Kim, H. S.; Phan, A. M.

2010-01-01

A Technology Computer Aided Design (TCAD) simulation-based method is developed to evaluate whether derating of high-energy heavy-ion accelerator test data bounds the risk for single-event gate rupture (SEGR) from much higher energy on-orbit ions for a mission linear energy transfer (LET) requirement. It is shown that a typical derating factor of 0.75 applied to a single-event effect (SEE) response curve defined by high-energy accelerator SEGR test data provides reasonable on-orbit hardness assurance, although in a high-voltage power MOSFET, it did not bound the risk of failure.

Single Event Rates for Devices Sensitive to Particle Energy

NASA Technical Reports Server (NTRS)

Edmonds, L. D.; Scheick, L. Z.; Banker, M. W.

2012-01-01

Single event rates (SER) can include contributions from low-energy particles such that the linear energy transfer (LET) is not constant. Previous work found that the environmental description that is most relevant to the low-energy contribution to the rate is a "stopping rate per unit volume" even when the physical mechanisms for a single-event effect do not require an ion to stop in some device region. Stopping rate tables are presented for four heavy-ion environments that are commonly used to assess device suitability for space applications. A conservative rate estimate utilizing limited test data is derived, and the example of SEGR rate in a power MOSFET is presented.

Software resilience and the effectiveness of software mitigation in microcontrollers

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

Quinn, Heather; Baker, Zachary; Fairbanks, Tom

Commercially available microprocessors could be useful to the space community for noncritical computations. There are many possible components that are smaller, lower-power, and less expensive than traditional radiation-hardened microprocessors. Many commercial microprocessors have issues with single-event effects (SEEs), such as single-event upsets (SEUs) and single-event transients (SETs), that can cause the microprocessor to calculate an incorrect result or crash. In this paper we present the Trikaya technique for masking SEUs and SETs through software mitigation techniques. Furthermore, test results show that this technique can be very effective at masking errors, making it possible to fly these microprocessors for a varietymore » of missions.« less

Software resilience and the effectiveness of software mitigation in microcontrollers

DOE PAGES

Quinn, Heather; Baker, Zachary; Fairbanks, Tom; ...

2015-12-01

Commercially available microprocessors could be useful to the space community for noncritical computations. There are many possible components that are smaller, lower-power, and less expensive than traditional radiation-hardened microprocessors. Many commercial microprocessors have issues with single-event effects (SEEs), such as single-event upsets (SEUs) and single-event transients (SETs), that can cause the microprocessor to calculate an incorrect result or crash. In this paper we present the Trikaya technique for masking SEUs and SETs through software mitigation techniques. Furthermore, test results show that this technique can be very effective at masking errors, making it possible to fly these microprocessors for a varietymore » of missions.« less

Single Event Effects and Total Dose Testing of the Intersil ISL 70003SEH Integrated Point of Load Converter

NASA Astrophysics Data System (ADS)

van Vonno, N. W.; White, J. D.; Pearce, L. G.; Thomson, E. J.; Gill, J. S.; Mansilla, O. E.

2014-08-01

Single-event transient (SET) phenomena in power management applications has evolved into a key issue, particularly in point of load (POL) buck regulators, as the loads driven by these devices are sensitive to even short-term overvoltage conditions. We preface this paper by a discussion of earlier destructive and nondestructive SEE testing of Intersil integrated point of load regulators, with emphasis on SET phenomena and some of the lessons learned in this work. We then report recent results of SET and destructive SEE testing of the ISL70003SEH POL converter, together with a brief discussion of the part's electrical and radiation hardness specifications. We conclude with a brief overview of low and high dose rate total dose testing of the part.

Mitigating Upsets in SRAM Based FPGAs from the Xilinix Virtex 2 Family

NASA Technical Reports Server (NTRS)

Swift, Gary M.; Yui, Candice C.; Carmichael, Carl; Koga, Rocky; George, Jeffrey S.

2003-01-01

This slide presentation reviews the single event upset static testing of the Virtex II field programmable gate arrays (FPGA) that were tested in protons and heavy-ions. The test designs and static and dynamic test results are reviewed.

Leveraging Long-term Seismic Catalogs for Automated Real-time Event Classification

NASA Astrophysics Data System (ADS)

Linville, L.; Draelos, T.; Pankow, K. L.; Young, C. J.; Alvarez, S.

2017-12-01

We investigate the use of labeled event types available through reviewed seismic catalogs to produce automated event labels on new incoming data from the crustal region spanned by the cataloged events. Using events cataloged by the University of Utah Seismograph Stations between October, 2012 and June, 2017, we calculate the spectrogram for a time window that spans the duration of each event as seen on individual stations, resulting in 110k event spectrograms (50% local earthquakes examples, 50% quarry blasts examples). Using 80% of the randomized example events ( 90k), a classifier is trained to distinguish between local earthquakes and quarry blasts. We explore variations of deep learning classifiers, incorporating elements of convolutional and recurrent neural networks. Using a single-layer Long Short Term Memory recurrent neural network, we achieve 92% accuracy on the classification task on the remaining 20K test examples. Leveraging the decisions from a group of stations that detected the same event by using the median of all classifications in the group increases the model accuracy to 96%. Additional data with equivalent processing from 500 more recently cataloged events (July, 2017), achieves the same accuracy as our test data on both single-station examples and multi-station medians, suggesting that the model can maintain accurate and stable classification rates on real-time automated events local to the University of Utah Seismograph Stations, with potentially minimal levels of re-training through time.

Texas Instruments-Digital Signal Processor(TI-DSP)SMJ320F20 SEL Testing

NASA Technical Reports Server (NTRS)

Sanders, Anthony B.; Poivey, C.; Kim, H. S.; Gee, George B.

2006-01-01

This viewgraph presentation reviews the testing of the Texas Instrument Digital Signal Processor(TI-DSP)SMJ320F20. Tests were performed to screen for susceptibility to Single Event Latchup (SEL) and measure sensitivity as a function of Linear Energy Transfer (LET) for an application specific test setup. The Heavy Ion Testing of two TI-DSP SMJ320F240 devices experienced Single Event Latchup (SEL) conditions at an LET of 1.8 MeV/(mg/square cm) The devices were exposed from a fluence of 1.76 x l0(exp 3) to 5.00 x 10(exp 6) particles/square cm of the Neon, Argon and Krypton ion beams. For DI(sub DD) an average latchup current occurred at about 700mA, which is a magnitude of 10 over the nominal current of 700mA.

Automated Detection of Obstructive Sleep Apnea Events from a Single-Lead Electrocardiogram Using a Convolutional Neural Network.

PubMed

Urtnasan, Erdenebayar; Park, Jong-Uk; Joo, Eun-Yeon; Lee, Kyoung-Joung

2018-04-23

In this study, we propose a method for the automated detection of obstructive sleep apnea (OSA) from a single-lead electrocardiogram (ECG) using a convolutional neural network (CNN). A CNN model was designed with six optimized convolution layers including activation, pooling, and dropout layers. One-dimensional (1D) convolution, rectified linear units (ReLU), and max pooling were applied to the convolution, activation, and pooling layers, respectively. For training and evaluation of the CNN model, a single-lead ECG dataset was collected from 82 subjects with OSA and was divided into training (including data from 63 patients with 34,281 events) and testing (including data from 19 patients with 8571 events) datasets. Using this CNN model, a precision of 0.99%, a recall of 0.99%, and an F 1 -score of 0.99% were attained with the training dataset; these values were all 0.96% when the CNN was applied to the testing dataset. These results show that the proposed CNN model can be used to detect OSA accurately on the basis of a single-lead ECG. Ultimately, this CNN model may be used as a screening tool for those suspected to suffer from OSA.

Recent Radiation Test Results for Power MOSFETs

NASA Technical Reports Server (NTRS)

Lauenstein, Jean-Marie; Topper, Alyson D.; Casey, Megan C.; Wilcox, Edward P.; Phan, Anthony M.; Kim, Hak S.; LaBel, Kenneth A.

2013-01-01

Single-event effect (SEE) and total ionizing dose (TID) test results are presented for various hardened and commercial power metal-oxide-semiconductor field effect transistors (MOSFETs), including vertical planar, trench, superjunction, and lateral process designs.

Single Event Effects Testing For Low Earth Orbit Missions with Neutrons

NASA Technical Reports Server (NTRS)

Reddell, Brandon; O'Neill, Pat; Bailey, Chuck; Nguyen, Kyson

2015-01-01

Neutrons can effectively be used to screen electronic parts intended to be used in Low Earth Orbit. This paper compares neutron with proton environments in spacecraft and discusses recent comparison testing.

Irradiation setup at the U-120M cyclotron facility

NASA Astrophysics Data System (ADS)

Křížek, F.; Ferencei, J.; Matlocha, T.; Pospíšil, J.; Príbeli, P.; Raskina, V.; Isakov, A.; Štursa, J.; Vaňát, T.; Vysoká, K.

2018-06-01

This paper describes parameters of the proton beams provided by the U-120M cyclotron and the related irradiation setup at the open access irradiation facility at the Nuclear Physics Institute of the Czech Academy of Sciences. The facility is suitable for testing radiation hardness of various electronic components. The use of the setup is illustrated by a measurement of an error rate for errors caused by Single Event Transients in an SRAM-based Xilinx XC3S200 FPGA. This measurement provides an estimate of a possible occurrence of Single Event Transients. Data suggest that the variation of error rate of the Single Event Effects for different clock phase shifts is not significant enough to use clock phase alignment with the beam as a fault mitigation technique.

Considerations for GPU SEE Testing

NASA Technical Reports Server (NTRS)

Wyrwas, Edward J.

2017-01-01

This presentation will discuss the considerations an engineer should take to perform Single Event Effects (SEE) testing on GPU devices. Notable topics will include setup complexity, architecture insight which permits cross platform normalization, acquiring a reasonable detail of information from the test suite, and a few lessons learned from preliminary testing.

Radiation Damage and Single Event Effect Results for Candidate Spacecraft Electronics

NASA Technical Reports Server (NTRS)

OBryan, Martha V.; LaBel, Kenneth A.; Reed, Robert A.; Howard, James W., Jr.; Ladbury, Ray L.; Barth, Janet L.; Kniffin, Scott D.; Seidleck, Christina M.; Marshall, Paul W.; Marshall, Cheryl J.;

Multiple disturbances classifier for electric signals using adaptive structuring neural networks

NASA Astrophysics Data System (ADS)

Lu, Yen-Ling; Chuang, Cheng-Long; Fahn, Chin-Shyurng; Jiang, Joe-Air

2008-07-01

This work proposes a novel classifier to recognize multiple disturbances for electric signals of power systems. The proposed classifier consists of a series of pipeline-based processing components, including amplitude estimator, transient disturbance detector, transient impulsive detector, wavelet transform and a brand-new neural network for recognizing multiple disturbances in a power quality (PQ) event. Most of the previously proposed methods usually treated a PQ event as a single disturbance at a time. In practice, however, a PQ event often consists of various types of disturbances at the same time. Therefore, the performances of those methods might be limited in real power systems. This work considers the PQ event as a combination of several disturbances, including steady-state and transient disturbances, which is more analogous to the real status of a power system. Six types of commonly encountered power quality disturbances are considered for training and testing the proposed classifier. The proposed classifier has been tested on electric signals that contain single disturbance or several disturbances at a time. Experimental results indicate that the proposed PQ disturbance classification algorithm can achieve a high accuracy of more than 97% in various complex testing cases.

Incorporating Probability Models of Complex Test Structures to Perform Technology Independent FPGA Single Event Upset Analysis

NASA Technical Reports Server (NTRS)

Berg, M. D.; Kim, H. S.; Friendlich, M. A.; Perez, C. E.; Seidlick, C. M.; LaBel, K. A.

2011-01-01

We present SEU test and analysis of the Microsemi ProASIC3 FPGA. SEU Probability models are incorporated for device evaluation. Included is a comparison to the RTAXS FPGA illustrating the effectiveness of the overall testing methodology.

A Compendium of Recent Optocoupler Radiation Test Data

NASA Technical Reports Server (NTRS)

Label, K. A.; Kniffin, S. D.; Reed, R. A.; Kim, H. S.; Wert, J. L.; Oberg, D. L.; Normand, E.; Johnston, A. H.; Lum, G. K.; Koga, R.;

A novel approach for analyzing data on recurrent events with duration to estimate the combined cumulative rate of both variables over time.

PubMed

Bhattacharya, Sudipta

2018-06-01

Recurrent adverse events, once occur often continue for some duration of time in clinical trials; and the number of events along with their durations is clinically considered as a measure of severity of a disease under study. While there are methods available for analyzing recurrent events or durations or for analyzing both side by side, no effort has been made so far to combine them and present as a single measure. However, this single-valued combined measure may help clinicians assess the wholesome effect of recurrence of incident comprising events and durations. Non-parametric approach is adapted here to develop an estimator for estimating the combined rate of both, the recurrence of events as well as the event-continuation, that is the duration per event. The proposed estimator produces a single numerical value, the interpretation and meaningfulness of which are discussed through the analysis of a real-life clinical dataset. The algebraic expression of variance is derived, asymptotic normality of the estimator is noted, and demonstration is provided on how the estimator can be used in the setup of testing of statistical hypothesis. Further possible development of the estimator is also noted, to adjust for the dependence of event occurrences on the history of the process generating recurrent events through covariates and for the case of dependent censoring.

Exploring the Potential of Direct-To-Consumer Genomic Test Data for Predicting Adverse Drug Events.

PubMed

Zhang, Patrick M; Sarkar, Indra Neil

2018-01-01

Recent technological advancements in genetic testing and the growing accessibility of public genomic data provide researchers with a unique avenue to approach personalized medicine. This feasibility study examined the potential of direct-to-consumer (DTC) genomic tests (focusing on 23andMe) in research and clinical applications. In particular, we combined population genetics information from the Personal Genome Project with adverse event reports from AEOLUS and pharmacogenetic information from PharmGKB. Primarily, associations between drugs based on co-occurring genetic variations and associations between variants and adverse events were used to assess the potential for leveraging single nucleotide polymorphism information from 23andMe. The results of this study suggest potential clinical uses of DTC tests in light of potential drug interactions. Furthermore, the results suggest great potential for analyzing associations at a population level to facilitate knowledge discovery in the realm of predicting adverse drug events.

Compendium of Single Event Effects (SEE) Test Results for COTS and Standard Electronics for Low Earth Orbit and Deep Space Applications

NASA Technical Reports Server (NTRS)

Reddell, Brandon; Bailey, Chuck; Nguyen, Kyson; O'Neill, Patrick; Gaza, Razvan; Patel, Chirag; Cooper, Jaime; Kalb, Theodore

2017-01-01

We present the results of SEE testing with high energy protons and with low and high energy heavy ions. This paper summarizes test results for components considered for Low Earth Orbit and Deep Space applications.

Radiation Test Results on COTS and non-COTS Electronic Devices for NASA-JSC Space Flight Projects

NASA Technical Reports Server (NTRS)

Allums, Kimberly K.; O'Neill, P. M.; Reddell, B. D.; Nguyen, K. V.; Bailey, C. R.

2012-01-01

This presentation reports the results of recent proton and heavy ion Single Event Effect (SEE) testing on a variety of COTS and non-COTs electronic devices and assemblies tested for the Space Shuttle, International Space Station (ISS) and Multi-Purpose Crew Vehicle (MPCV).

Simultaneous Determination of Structure and Event Location Using Body and Surface Wave Measurements at a Single Station: Preparation for Mars Data from the InSight Mission

NASA Astrophysics Data System (ADS)

Panning, M. P.; Banerdt, W. B.; Beucler, E.; Blanchette-Guertin, J. F.; Boese, M.; Clinton, J. F.; Drilleau, M.; James, S. R.; Kawamura, T.; Khan, A.; Lognonne, P. H.; Mocquet, A.; van Driel, M.

2015-12-01

An important challenge for the upcoming InSight mission to Mars, which will deliver a broadband seismic station to Mars along with other geophysical instruments in 2016, is to accurately determine event locations with the use of a single station. Locations are critical for the primary objective of the mission, determining the internal structure of Mars, as well as a secondary objective of measuring the activity of distribution of seismic events. As part of the mission planning process, a variety of techniques have been explored for location of marsquakes and inversion of structure, and preliminary procedures and software are already under development as part of the InSight Mars Quake and Mars Structure Services. One proposed method, involving the use of recordings of multiple-orbit surface waves, has already been tested with synthetic data and Earth recordings. This method has the strength of not requiring an a priori velocity model of Mars for quake location, but will only be practical for larger events. For smaller events where only first orbit surface waves and body waves are observable, other methods are required. In this study, we implement a transdimensional Bayesian inversion approach to simultaneously invert for basic velocity structure and location parameters (epicentral distance and origin time) using only measurements of body wave arrival times and dispersion of first orbit surface waves. The method is tested with synthetic data with expected Mars noise and Earth data for single events and groups of events and evaluated for errors in both location and structural determination, as well as tradeoffs between resolvable parameters and the effect of 3D crustal variations.

Adverse events associated with single dose oral analgesics for acute postoperative pain in adults - an overview of Cochrane reviews.

PubMed

Moore, R Andrew; Derry, Sheena; Aldington, Dominic; Wiffen, Philip J

2015-10-13

This is an update of a Cochrane overview published in Issue 9, 2011; that overview considered both efficacy and adverse events. This overview considers adverse events, with efficacy dealt with in a separate overview.Thirty-nine Cochrane reviews of randomised trials have examined the adverse events associated with individual drug interventions in acute postoperative pain. This overview brings together the results of those individual reviews. To provide an overview of adverse event rates associated with single-dose oral analgesics, compared with placebo, for acute postoperative pain in adults. We identified systematic reviews in The Cochrane Database of Systematic Reviews on The Cochrane Library through a simple search strategy. All reviews were overseen by a single review group. We extracted information related to participants experiencing any adverse event, and reports of serious adverse events, and deaths from the individual reviews. Information was available from 39 Cochrane reviews for 41 different analgesics or analgesic combinations (51 drug/dose/formulations) tested in single oral doses in participants with moderate or severe postoperative pain. This involved around 350 unique studies involving about 35,000 participants. Most studies involved younger participants with pain following removal of molar teeth.For most nonsteroidal anti-inflammatory drugs (NSAIDs), paracetamol, and combinations not containing opioids, there were few examples where participants experienced significantly more or fewer adverse events than with placebo. For aspirin 1000 mg and diflunisal 1000 mg, opioids, or fixed-dose combination drugs containing opioids, participants typically experienced significantly more adverse events than with placebo. Studies of combinations of ibuprofen and paracetamol reported significantly fewer adverse events.Serious adverse events were rare, occurring a rate of about 1 in 3200 participants.Most reviews did not report specific adverse events. Despite ongoing problems with the measurement, recording, and reporting of adverse events in clinical trials and in systematic reviews, the large amount of information available for single oral doses of analgesics provides evidence that adverse events rates are generally similar with active drug and placebo in these circumstances, except at higher doses of some drugs, and in combinations including opioids.

Single Event Upset Rate Estimates for a 16-K CMOS (Complementary Metal Oxide Semiconductor) SRAM (Static Random Access Memory).

DTIC Science & Technology

1986-09-30

4 . ~**..ft.. ft . - - - ft SI TABLES 9 I. SA32~40 Single Event Upset Test, 1140-MeV Krypton, 9/l8/8~4. . .. .. .. .. .. .16 II. CRUP Simulation...cosmic ray interaction analysis described in the remainder of this report were calculated using the CRUP computer code 3 modified for funneling. The... CRUP code requires, as inputs, the size of a depletion region specified as a retangular parallel piped with dimensions a 9 b S c, the effective funnel

Single-Trial Normalization for Event-Related Spectral Decomposition Reduces Sensitivity to Noisy Trials

PubMed Central

Grandchamp, Romain; Delorme, Arnaud

2011-01-01

In electroencephalography, the classical event-related potential model often proves to be a limited method to study complex brain dynamics. For this reason, spectral techniques adapted from signal processing such as event-related spectral perturbation (ERSP) – and its variant event-related synchronization and event-related desynchronization – have been used over the past 20 years. They represent average spectral changes in response to a stimulus. These spectral methods do not have strong consensus for comparing pre- and post-stimulus activity. When computing ERSP, pre-stimulus baseline removal is usually performed after averaging the spectral estimate of multiple trials. Correcting the baseline of each single-trial prior to averaging spectral estimates is an alternative baseline correction method. However, we show that this method leads to positively skewed post-stimulus ERSP values. We eventually present new single-trial-based ERSP baseline correction methods that perform trial normalization or centering prior to applying classical baseline correction methods. We show that single-trial correction methods minimize the contribution of artifactual data trials with high-amplitude spectral estimates and are robust to outliers when performing statistical inference testing. We then characterize these methods in terms of their time–frequency responses and behavior compared to classical ERSP methods. PMID:21994498

Event boundaries and memory improvement.

PubMed

Pettijohn, Kyle A; Thompson, Alexis N; Tamplin, Andrea K; Krawietz, Sabine A; Radvansky, Gabriel A

2016-03-01

The structure of events can influence later memory for information that is embedded in them, with evidence indicating that event boundaries can both impair and enhance memory. The current study explored whether the presence of event boundaries during encoding can structure information to improve memory. In Experiment 1, memory for a list of words was tested in which event structure was manipulated by having participants walk through a doorway, or not, halfway through the word list. In Experiment 2, memory for lists of words was tested in which event structure was manipulated using computer windows. Finally, in Experiments 3 and 4, event structure was manipulated by having event shifts described in narrative texts. The consistent finding across all of these methods and materials was that memory was better when the information was distributed across two events rather than combined into a single event. Moreover, Experiment 4 demonstrated that increasing the number of event boundaries from one to two increased the memory benefit. These results are interpreted in the context of the Event Horizon Model of event cognition. Copyright © 2015 Elsevier B.V. All rights reserved.

Automatic Single Event Effects Sensitivity Analysis of a 13-Bit Successive Approximation ADC

NASA Astrophysics Data System (ADS)

Márquez, F.; Muñoz, F.; Palomo, F. R.; Sanz, L.; López-Morillo, E.; Aguirre, M. A.; Jiménez, A.

2015-08-01

This paper presents Analog Fault Tolerant University of Seville Debugging System (AFTU), a tool to evaluate the Single-Event Effect (SEE) sensitivity of analog/mixed signal microelectronic circuits at transistor level. As analog cells can behave in an unpredictable way when critical areas interact with the particle hitting, there is a need for designers to have a software tool that allows an automatic and exhaustive analysis of Single-Event Effects influence. AFTU takes the test-bench SPECTRE design, emulates radiation conditions and automatically evaluates vulnerabilities using user-defined heuristics. To illustrate the utility of the tool, the SEE sensitivity of a 13-bits Successive Approximation Analog-to-Digital Converter (ADC) has been analysed. This circuit was selected not only because it was designed for space applications, but also due to the fact that a manual SEE sensitivity analysis would be too time-consuming. After a user-defined test campaign, it was detected that some voltage transients were propagated to a node where a parasitic diode was activated, affecting the offset cancelation, and therefore the whole resolution of the ADC. A simple modification of the scheme solved the problem, as it was verified with another automatic SEE sensitivity analysis.

Considerations for a Proton Single Event Effects (SEE) Guideline

NASA Technical Reports Server (NTRS)

LaBel, Kenneth A.

2010-01-01

The intent of this document is to provide guidance on when and what type of -SEE tests should be performed on a device under test (OUT) based on orbit, technology, existing data, and application. It is NOT intended to provide a detailed guideline for how to perform proton SEE radiation tests on electronics.

Considerations for a Proton Single Event Effects (SEE) Guideline

NASA Technical Reports Server (NTRS)

LaBel, Kenneth A.

2010-01-01

The intent of this document is to provide guidance on when and what type of SEE tests should be performed on a device under test (DUT) based on orbit, technology, existing data, and application. It is NOT intended to provide a detailed guideline for how to perform proton SEE radiation tests on electronics.

Single Event Effect microchip testing at the Texas A&M University Cyclotron Institute

NASA Astrophysics Data System (ADS)

Clark, Henry; Yennello, Sherry; Texas A&M University-Cyclotron Institute Team

2015-10-01

A Single Event Effect (SEE) is caused by a single, energetic particle that deposits a sufficient amount of charge in a device as it transverses it and upsets its normal operation. Soft errors are non-destructive and normally appear as transient pulses in logic or support circuitry, or as bit flips in memory cells or registers. Hard errors usually result in a high operating current, above device specifications, and must be cleared by a power reset. Burnout errors are so destructive that the device becomes operationally dead. Spacecraft designers must be concerned with the causes of SEE's from protons and heavy ions since commercial devices are typically chosen reduce the parameters of power, weight, volume and cost but have increased functionality, which in turn are typically vulnerable to SEE. As a result all mission-critical devices must be tested. The TAMU K500 superconducting cyclotron has provided beams for space radiation testing since 1994. Starting at just 100 hours/year at inception, the demand has grown to 3000 hours/year. In recent years, most beam time has been for US defense system testing. Nearly 15% has been provided for foreign agencies from Europe and Asia. An overview of the testing facility and future plans will be presented.

Use of Commercial FPGA-Based Evaluation Boards for Single-Event Testing of DDR2 and DDR3 SDRAMs

NASA Technical Reports Server (NTRS)

Ladbury, R. L.; Berg, M. D.; Wilcox, E. P.; LaBel, K. A.; Kim, H. S.; Phan, A. M.; Seidleck, C. M.

2013-01-01

We investigate the use of commercial FPGA based evaluation boards for radiation testing DDR2 and DDR3 SDRAMs. We evaluate the resulting data quality and the tradeoffs involved in the use of these boards.

Effects of heavy ion radiation on digital micromirror device performance

NASA Astrophysics Data System (ADS)

Travinsky, Anton; Vorobiev, Dmitry; Ninkov, Zoran; Raisanen, Alan D.; Pellish, Jonny; Robberto, Massimo; Heap, Sara

2016-09-01

There is a pressing need in the astronomical community for space-suitable multiobject spectrometers (MOSs). Several digital micromirror device (DMD)-based prototype MOSs have been developed for ground-based observatories; however, their main use will come with deployment on a space-based mission. Therefore, the performance of DMDs under exoatmospheric radiation needs to be evaluated. DMDs were rewindowed with 2-μm thick pellicle and tested under accelerated heavy-ion radiation (control electronics shielded from radiation), with a focus on the detection of single-event effects (SEEs) including latch-up events. Testing showed that while DMDs are sensitive to nondestructive ion-induced state changes, all SEEs are cleared with a soft reset (i.e., sending a pattern to the device). The DMDs did not experience single-event induced permanent damage or functional changes that required a hard reset (power cycle), even at high ion fluences. This suggests that the SSE rate burden will be manageable for a DMD-based instrument when exposed to solar particle fluxes and cosmic rays in orbit.

Single-event and total-dose effects in geo-stationary transfer orbit during solar-activity maximum period measured by the Tsubasa satellite

NASA Astrophysics Data System (ADS)

Koshiishi, H.; Kimoto, Y.; Matsumoto, H.; Goka, T.

The Tsubasa satellite developed by the Japan Aerospace Exploration Agency was launched in Feb 2002 into Geo-stationary Transfer Orbit GTO Perigee 500km Apogee 36000km and had been operated well until Sep 2003 The objective of this satellite was to verify the function of commercial parts and new technologies of bus-system components in space Thus the on-board experiments were conducted in the more severe radiation environment of GTO rather than in Geo-stationary Earth Orbit GEO or Low Earth Orbit LEO The Space Environment Data Acquisition equipment SEDA on board the Tsubasa satellite had the Single-event Upset Monitor SUM and the DOSimeter DOS to evaluate influences on electronic devices caused by radiation environment that was also measured by the particle detectors of the SEDA the Standard DOse Monitor SDOM for measurements of light particles and the Heavy Ion Telescope HIT for measurements of heavy ions The SUM monitored single-event upsets and single-event latch-ups occurred in the test sample of two 64-Mbit DRAMs The DOS measured accumulated radiation dose at fifty-six locations in the body of the Tsubasa satellite Using the data obtained by these instruments single-event and total-dose effects in GTO during solar-activity maximum period especially their rapid changes due to solar flares and CMEs in the region from L 1 1 through L 11 is discussed in this paper

Do you really represent my task? Sequential adaptation effects to unexpected events support referential coding for the joint Simon effect.

PubMed

Klempova, Bibiana; Liepelt, Roman

2016-07-01

Recent findings suggest that a Simon effect (SE) can be induced in Individual go/nogo tasks when responding next to an event-producing object salient enough to provide a reference for the spatial coding of one's own action. However, there is skepticism against referential coding for the joint Simon effect (JSE) by proponents of task co-representation. In the present study, we tested assumptions of task co-representation and referential coding by introducing unexpected double response events in a joint go/nogo and a joint independent go/nogo task. In Experiment 1b, we tested if task representations are functionally similar in joint and standard Simon tasks. In Experiment 2, we tested sequential updating of task co-representation after unexpected single response events in the joint independent go/nogo task. Results showed increased JSEs following unexpected events in the joint go/nogo and joint independent go/nogo task (Experiment 1a). While the former finding is in line with the assumptions made by both accounts (task co-representation and referential coding), the latter finding supports referential coding. In contrast to Experiment 1a, we found a decreased SE after unexpected events in the standard Simon task (Experiment 1b), providing evidence against the functional equivalence assumption between joint and two-choice Simon tasks of the task co-representation account. Finally, we found an increased JSE also following unexpected single response events (Experiment 2), ruling out that the findings of the joint independent go/nogo task in Experiment 1a were due to a re-conceptualization of the task situation. In conclusion, our findings support referential coding also for the joint Simon effect.

Creation of a Radiation Hard 0.13 Micron CMOS Library at IHP

NASA Astrophysics Data System (ADS)

Jagdhold, U.

2010-08-01

To support space applications we will develop an 0.13 micron CMOS library which should be radiation hard up to 200 krad. By introducing new radiation hard design rules we will minimize IC-level leakage and single event latchup (SEL). To reduce single event upset (SEU) we will add two p-MOS transistors to all flip flops. For reliability reasons we will use double contacts in all library elements. The additional rules and the library elements will then be integrated in our Cadence mixed signal designkit, Virtuoso IC6.1 [1]. A test chip will be produced with our in house 0.13 micron BiCMOS technology, see Ref. [2].Thereafter we will doing radiation tests according the ESA specifications, see Ref. [3], [4].

Combining destination diversion decisions and critical in-flight event diagnosis in computer aided testing of pilots

NASA Technical Reports Server (NTRS)

Rockwell, T. H.; Giffin, W. C.; Romer, D. J.

1984-01-01

Rockwell and Giffin (1982) and Giffin and Rockwell (1983) have discussed the use of computer aided testing (CAT) in the study of pilot response to critical in-flight events. The present investigation represents an extension of these earlier studies. In testing pilot responses to critical in-flight events, use is made of a Plato-touch CRT system operating on a menu based format. In connection with the typical diagnostic problem, the pilot was presented with symptoms within a flight scenario. In one problem, the pilot has four minutes for obtaining the information which is needed to make a diagnosis of the problem. In the reported research, the attempt has been made to combine both diagnosis and diversion scenario into a single computer aided test. Tests with nine subjects were conducted. The obtained results and their significance are discussed.

What Reliability Engineers Should Know about Space Radiation Effects

NASA Technical Reports Server (NTRS)

DiBari, Rebecca

2013-01-01

Space radiation in space systems present unique failure modes and considerations for reliability engineers. Radiation effects is not a one size fits all field. Threat conditions that must be addressed for a given mission depend on the mission orbital profile, the technologies of parts used in critical functions and on application considerations, such as supply voltages, temperature, duty cycle, and redundancy. In general, the threats that must be addressed are of two types-the cumulative degradation mechanisms of total ionizing dose (TID) and displacement damage (DD). and the prompt responses of components to ionizing particles (protons and heavy ions) falling under the heading of single-event effects. Generally degradation mechanisms behave like wear-out mechanisms on any active components in a system: Total Ionizing Dose (TID) and Displacement Damage: (1) TID affects all active devices over time. Devices can fail either because of parametric shifts that prevent the device from fulfilling its application or due to device failures where the device stops functioning altogether. Since this failure mode varies from part to part and lot to lot, lot qualification testing with sufficient statistics is vital. Displacement damage failures are caused by the displacement of semiconductor atoms from their lattice positions. As with TID, failures can be either parametric or catastrophic, although parametric degradation is more common for displacement damage. Lot testing is critical not just to assure proper device fi.mctionality throughout the mission. It can also suggest remediation strategies when a device fails. This paper will look at these effects on a variety of devices in a variety of applications. This paper will look at these effects on a variety of devices in a variety of applications. (2) On the NEAR mission a functional failure was traced to a PIN diode failure caused by TID induced high leakage currents. NEAR was able to recover from the failure by reversing the current of a nearby Thermal Electric Cooler (turning the TEC into a heater). The elevated temperature caused the PIN diode to anneal and the device to recover. It was by lot qualification testing that NEAR knew the diode would recover when annealed. This paper will look at these effects on a variety of devices in a variety of applications. Single Event Effects (SEE): (1) In contrast to TID and displacement damage, Single Event Effects (SEE) resemble random failures. SEE modes can range from changes in device logic (single-event upset, or SEU). temporary disturbances (single-event transient) to catastrophic effects such as the destructive SEE modes, single-event latchup (SEL). single-event gate rupture (SEGR) and single-event burnout (SEB) (2) The consequences of nondestructive SEE modes such as SEU and SET depend critically on their application--and may range from trivial nuisance errors to catastrophic loss of mission. It is critical not just to ensure that potentially susceptible devices are well characterized for their susceptibility, but also to work with design engineers to understand the implications of each error mode. -For destructive SEE, the predominant risk mitigation strategy is to avoid susceptible parts, or if that is not possible. to avoid conditions under which the part may be susceptible. Destructive SEE mechanisms are often not well understood, and testing is slow and expensive, making rate prediction very challenging. (3) Because the consequences of radiation failure and degradation modes depend so critically on the application as well as the component technology, it is essential that radiation, component. design and system engineers work togetherpreferably starting early in the program to ensure critical applications are addressed in time to optimize the probability of mission success.

Proton Irradiation of the 16GB Intel Optane SSD

NASA Technical Reports Server (NTRS)

Wyrwas, E. J.

2017-01-01

The purpose of this test is to assess the single event effects (SEE) and radiation susceptibility of the Intel Optane Memory device (SSD) containing the 3D Xpoint phase change memory (PCM) technology. This test is supported by the NASA Electronics Parts and Packaging Program (NEPP).

Robust Covariate-Adjusted Log-Rank Statistics and Corresponding Sample Size Formula for Recurrent Events Data

PubMed Central

Song, Rui; Kosorok, Michael R.; Cai, Jianwen

2009-01-01

Summary Recurrent events data are frequently encountered in clinical trials. This article develops robust covariate-adjusted log-rank statistics applied to recurrent events data with arbitrary numbers of events under independent censoring and the corresponding sample size formula. The proposed log-rank tests are robust with respect to different data-generating processes and are adjusted for predictive covariates. It reduces to the Kong and Slud (1997, Biometrika 84, 847–862) setting in the case of a single event. The sample size formula is derived based on the asymptotic normality of the covariate-adjusted log-rank statistics under certain local alternatives and a working model for baseline covariates in the recurrent event data context. When the effect size is small and the baseline covariates do not contain significant information about event times, it reduces to the same form as that of Schoenfeld (1983, Biometrics 39, 499–503) for cases of a single event or independent event times within a subject. We carry out simulations to study the control of type I error and the comparison of powers between several methods in finite samples. The proposed sample size formula is illustrated using data from an rhDNase study. PMID:18162107

Heavy Ion and Proton-Induced Single Event Upset Characteristics of a 3D NAND Flash Memory

NASA Technical Reports Server (NTRS)

Chen, Dakai; Wilcox, Edward; Ladbury, Raymond; Seidleck, Christina; Kim, Hak; Phan, Anthony; Label, Kenneth

2017-01-01

We evaluated the effects of heavy ion and proton irradiation for a 3D NAND flash. The 3D NAND showed similar single-event upset (SEU) sensitivity to a planar NAND of identical density in the multiple-cell level (MLC) storage mode. The 3D NAND showed significantly reduced SEU susceptibility in single-level-cell (SLC) storage mode. Additionally, the 3D NAND showed less multiple-bit upset susceptibility than the planar NAND, with fewer number of upset bits per byte and smaller cross sections overall. However, the 3D architecture exhibited angular sensitivities for both base and face angles, reflecting the anisotropic nature of the SEU vulnerability in space. Furthermore, the SEU cross section decreased with increasing fluence for both the 3D NAND and the Micron 16 nm planar NAND, which suggests that typical heavy ion test fluences will underestimate the upset rate during a space mission. These unique characteristics introduce complexity to traditional ground irradiation test procedures.

Collapse and Earthquake Swarm After North Korea's 3 September 2017 Nuclear Test

NASA Astrophysics Data System (ADS)

Tian, Dongdong; Yao, Jiayuan; Wen, Lianxing

2018-05-01

North Korea's 3 September 2017 nuclear test was followed by several small seismic events, with one eight-and-a-half minutes after the test and three on and after 23 September 2017. Seismic analysis reveals that the first event is a near vertical on-site collapse toward the nuclear test center from 440 ± 260 m northwest of the test site, with its seismic source best represented by a single force with a dip angle of 70°-75° and an azimuth of 150°, and the later events are an earthquake swarm located 8.4 ± 1.7 km north of the test site within a region of 520 m, with a focal depth of at least 2.4 km and a focal mechanism of nearly pure strike slip along the north-south direction with a high dip angle of 50°-90°. The occurrence of the on-site collapse calls for continued monitoring of any leaks of radioactive materials from the test site.

Single event upset (SEU) testing at JPL

NASA Technical Reports Server (NTRS)

Coss, James R.

1987-01-01

It is believed that the increase in SEUs with more modern devices may have serious consequences for future space missions. The physics behind an SEU is discussed as well as SEU test philosophy and equipment, and testing results. It is concluded that the problem may be ameliorated by careful device selection and the use of redundancy or error correction.

Nonlinear Least-Squares Based Method for Identifying and Quantifying Single and Mixed Contaminants in Air with an Electronic Nose

PubMed Central

Zhou, Hanying; Homer, Margie L.; Shevade, Abhijit V.; Ryan, Margaret A.

2006-01-01

The Jet Propulsion Laboratory has recently developed and built an electronic nose (ENose) using a polymer-carbon composite sensing array. This ENose is designed to be used for air quality monitoring in an enclosed space, and is designed to detect, identify and quantify common contaminants at concentrations in the parts-per-million range. Its capabilities were demonstrated in an experiment aboard the National Aeronautics and Space Administration's Space Shuttle Flight STS-95. This paper describes a modified nonlinear least-squares based algorithm developed to analyze data taken by the ENose, and its performance for the identification and quantification of single gases and binary mixtures of twelve target analytes in clean air. Results from laboratory-controlled events demonstrate the effectiveness of the algorithm to identify and quantify a gas event if concentration exceeds the ENose detection threshold. Results from the flight test demonstrate that the algorithm correctly identifies and quantifies all registered events (planned or unplanned, as singles or mixtures) with no false positives and no inconsistencies with the logged events and the independent analysis of air samples.

Validation of an "Intelligent Mouthguard" Single Event Head Impact Dosimeter.

PubMed

Bartsch, Adam; Samorezov, Sergey; Benzel, Edward; Miele, Vincent; Brett, Daniel

2014-11-01

Dating to Colonel John Paul Stapp MD in 1975, scientists have desired to measure live human head impacts with accuracy and precision. But no instrument exists to accurately and precisely quantify single head impact events. Our goal is to develop a practical single event head impact dosimeter known as "Intelligent Mouthguard" and quantify its performance on the benchtop, in vitro and in vivo. In the Intelligent Mouthguard hardware, limited gyroscope bandwidth requires an algorithm-based correction as a function of impact duration. After we apply gyroscope correction algorithm, Intelligent Mouthguard results at time of CG linear acceleration peak correlate to the Reference Hybrid III within our tested range of pulse durations and impact acceleration profiles in American football and Boxing in vitro tests: American football, IMG=1.00REF-1.1g, R2=0.99; maximum time of peak XYZ component imprecision 3.6g and 370 rad/s2; maximum time of peak azimuth and elevation imprecision 4.8° and 2.9°; maximum average XYZ component temporal imprecision 3.3g and 390 rad/s2. Boxing, IMG=1.00REF-0.9 g, R2=0.99, R2=0.98; maximum time of peak XYZ component imprecision 3.9 g and 390 rad/s2, maximum time of peak azimuth and elevation imprecision 2.9° and 2.1°; average XYZ component temporal imprecision 4.0 g and 440 rad/s2. In vivo Intelligent Mouthguard true positive head impacts from American football players and amateur boxers have temporal characteristics (first harmonic frequency from 35 Hz to 79 Hz) within our tested benchtop (first harmonic frequency<180 Hz) and in vitro (first harmonic frequency<100 Hz) ranges. Our conclusions apply only to situations where the rigid body assumption is valid, sensor-skull coupling is maintained and the ranges of tested parameters and harmonics fall within the boundaries of harmonics validated in vitro. For these situations, Intelligent Mouthguard qualifies as a single event dosimeter in American football and Boxing.

Single-Word Multiple-Bit Upsets in Static Random Access Devices

DTIC Science & Technology

1998-01-15

Transactions on Nuclear Science, NS-33, 1616- 1619,1986. Criswell, T.L., P.R. Measel , and K.L. Walin, "Single Event Upset Testing with Relativistic...Heavy Ions," IEEE Transactions on Nuclear Science, NS-31, 1559- 1561,1984. 1946 3. Criswell, T.L., D.L. Oberg, J.L. Wert, P.R. Measel , and W.E

SEU Test Facility

Science.gov Websites

to the effects of ionizing radiation. This is of particular concern for space applications due to the develop a powerful and user-friendly test facility for investigating space-radiation effects on micro -electronic devices[1]. The main type of effects studied are the so called Single Event Upsets (SEUs) where

TVDG Home Page

Science.gov Websites

Download WinZip Radiation Effects Testing and Calibration This facility is available for the study of space radiation effects, in particular, Single Event Upset ( SEU ) Testing and Spacecraft Instrument Calibration information about our facility. Visit our Space and Radiation Effects Links page to find out what is going on

Detecting Earthquakes over a Seismic Network using Single-Station Similarity Measures

NASA Astrophysics Data System (ADS)

Bergen, Karianne J.; Beroza, Gregory C.

2018-03-01

New blind waveform-similarity-based detection methods, such as Fingerprint and Similarity Thresholding (FAST), have shown promise for detecting weak signals in long-duration, continuous waveform data. While blind detectors are capable of identifying similar or repeating waveforms without templates, they can also be susceptible to false detections due to local correlated noise. In this work, we present a set of three new methods that allow us to extend single-station similarity-based detection over a seismic network; event-pair extraction, pairwise pseudo-association, and event resolution complete a post-processing pipeline that combines single-station similarity measures (e.g. FAST sparse similarity matrix) from each station in a network into a list of candidate events. The core technique, pairwise pseudo-association, leverages the pairwise structure of event detections in its network detection model, which allows it to identify events observed at multiple stations in the network without modeling the expected move-out. Though our approach is general, we apply it to extend FAST over a sparse seismic network. We demonstrate that our network-based extension of FAST is both sensitive and maintains a low false detection rate. As a test case, we apply our approach to two weeks of continuous waveform data from five stations during the foreshock sequence prior to the 2014 Mw 8.2 Iquique earthquake. Our method identifies nearly five times as many events as the local seismicity catalog (including 95% of the catalog events), and less than 1% of these candidate events are false detections.

A SEU-Hard Flip-Flop for Antifuse FPGAs

NASA Technical Reports Server (NTRS)

Katz, R.; Wang, J. J.; McCollum, J.; Cronquist, B.; Chan, R.; Yu, D.; Kleyner, I.; Day, John H. (Technical Monitor)

2001-01-01

A single event upset (SEU)-hardened flip-flop has been designed and developed for antifuse Field Programmable Gate Array (FPGA) application. Design and application issues, testability, test methods, simulation, and results are discussed.

Managing Risk to Ensure a Successful Cassini/Huygens Saturn Orbit Insertion (SOI)

NASA Technical Reports Server (NTRS)

Witkowski, Mona M.; Huh, Shin M.; Burt, John B.; Webster, Julie L.

2004-01-01

I. Design: a) S/C designed to be largely single fault tolerant; b) Operate in flight demonstrated envelope, with margin; and c) Strict compliance with requirements & flight rules. II. Test: a) Baseline, fault & stress testing using flight system testbeds (H/W & S/W); b) In-flight checkout & demos to remove first time events. III. Failure Analysis: a) Critical event driven fault tree analysis; b) Risk mitigation & development of contingencies. IV) Residual Risks: a) Accepted pre-launch waivers to Single Point Failures; b) Unavoidable risks (e.g. natural disaster). V) Mission Assurance: a) Strict process for characterization of variances (ISAs, PFRs & Waivers; b) Full time Mission Assurance Manager reports to Program Manager: 1) Independent assessment of compliance with institutional standards; 2) Oversight & risk assessment of ISAs, PFRs & Waivers etc.; and 3) Risk Management Process facilitator.

Multiclass classification of obstructive sleep apnea/hypopnea based on a convolutional neural network from a single-lead electrocardiogram.

PubMed

Urtnasan, Erdenebayar; Park, Jong-Uk; Lee, Kyoung-Joung

2018-05-24

In this paper, we propose a convolutional neural network (CNN)-based deep learning architecture for multiclass classification of obstructive sleep apnea and hypopnea (OSAH) using single-lead electrocardiogram (ECG) recordings. OSAH is the most common sleep-related breathing disorder. Many subjects who suffer from OSAH remain undiagnosed; thus, early detection of OSAH is important. In this study, automatic classification of three classes-normal, hypopnea, and apnea-based on a CNN is performed. An optimal six-layer CNN model is trained on a training dataset (45,096 events) and evaluated on a test dataset (11,274 events). The training set (69 subjects) and test set (17 subjects) were collected from 86 subjects with length of approximately 6 h and segmented into 10 s durations. The proposed CNN model reaches a mean -score of 93.0 for the training dataset and 87.0 for the test dataset. Thus, proposed deep learning architecture achieved a high performance for multiclass classification of OSAH using single-lead ECG recordings. The proposed method can be employed in screening of patients suspected of having OSAH. © 2018 Institute of Physics and Engineering in Medicine.

Effects of space radiation on electronic microcircuits

NASA Technical Reports Server (NTRS)

Kolasinski, W. A.

1989-01-01

The single event effects or phenomena (SEP), which so far have been observed as events falling on one or another of the SE classes: Single Event Upset (SEU), Single Event Latchup (SEL) and Single Event Burnout (SEB), are examined. Single event upset is defined as a lasting, reversible change in the state of a multistable (usually bistable) electronic circuit such as a flip-flop or latch. In a computer memory, SEUs manifest themselves as unexplained bit flips. Since latchup is in general caused by a single event of short duration, the single event part of the SEL term is superfluous. Nevertheless, it is used customarily to differentiate latchup due to a single heavy charged particle striking a sensitive cell from more ordinary kinds of latchup. Single event burnout (SEB) refers usually to total instantaneous failure of a power FET when struck by a single particle, with the device shorting out the power supply. An unforeseen failure of these kinds can be catastrophic to a space mission, and the possibilities are discussed.

Annual Conference on Nuclear and Space Radiation Effects, 18th, University of Washington, Seattle, WA, July 21-24, 1981, Proceedings

NASA Technical Reports Server (NTRS)

Tasca, D. M.

1981-01-01

Single event upset phenomena are discussed, taking into account cosmic ray induced errors in IIL microprocessors and logic devices, single event upsets in NMOS microprocessors, a prediction model for bipolar RAMs in a high energy ion/proton environment, the search for neutron-induced hard errors in VLSI structures, soft errors due to protons in the radiation belt, and the use of an ion microbeam to study single event upsets in microcircuits. Basic mechanisms in materials and devices are examined, giving attention to gamma induced noise in CCD's, the annealing of MOS capacitors, an analysis of photobleaching techniques for the radiation hardening of fiber optic data links, a hardened field insulator, the simulation of radiation damage in solids, and the manufacturing of radiation resistant optical fibers. Energy deposition and dosimetry is considered along with SGEMP/IEMP, radiation effects in devices, space radiation effects and spacecraft charging, EMP/SREMP, and aspects of fabrication, testing, and hardness assurance.

Shortcomings in ground testing, environment simulations, and performance predictions for space applications

NASA Technical Reports Server (NTRS)

Stassinopoulos, E. G.; Brucker, G. J.

1992-01-01

This paper addresses the issues involved in radiation testing of devices and subsystems to obtain the data that are required to predict the performance and survivability of satellite systems for extended missions in space. The problems associated with space environmental simulations, or the lack thereof, in experiments intended to produce information to describe the degradation and behavior of parts and systems are discussed. Several types of radiation effects in semiconductor components are presented, as for example: ionization dose effects, heavy ion and proton induced Single Event Upsets (SEUs), and Single Event Transient Upsets (SETUs). Examples and illustrations of data relating to these ground testing issues are provided. The primary objective of this presentation is to alert the reader to the shortcomings, pitfalls, variabilities, and uncertainties in acquiring information to logically design electronic subsystems for use in satellites or space stations with long mission lifetimes, and to point out the weaknesses and deficiencies in the methods and procedures by which that information is obtained.

Statistical Properties of SEE Rate Calculation in the Limits of Large and Small Event Counts

NASA Technical Reports Server (NTRS)

Ladbury, Ray

2007-01-01

This viewgraph presentation reviews the Statistical properties of Single Event Effects (SEE) rate calculations. The goal of SEE rate calculation is to bound the SEE rate, though the question is by how much. The presentation covers: (1) Understanding errors on SEE cross sections, (2) Methodology: Maximum Likelihood and confidence Contours, (3) Tests with Simulated data and (4) Applications.

Computing in the presence of soft bit errors. [caused by single event upset on spacecraft

NASA Technical Reports Server (NTRS)

Rasmussen, R. D.

1984-01-01

It is shown that single-event-upsets (SEUs) due to cosmic rays are a significant source of single bit error in spacecraft computers. The physical mechanism of SEU, electron hole generation by means of Linear Energy Transfer (LET), it discussed with reference made to the results of a study of the environmental effects on computer systems of the Galileo spacecraft. Techniques for making software more tolerant of cosmic ray effects are considered, including: reducing the number of registers used by the software; continuity testing of variables; redundant execution of major procedures for error detection; and encoding state variables to detect single-bit changes. Attention is also given to design modifications which may reduce the cosmic ray exposure of on-board hardware. These modifications include: shielding components operating in LEO; removing low-power Schottky parts; and the use of CMOS diodes. The SEU parameters of different electronic components are listed in a table.

Radiation-Induced Transient Effects in Near Infrared Focal Plane Arrays

NASA Technical Reports Server (NTRS)

Reed, Robert A.; Pickel, J.; Marshall, P.; Waczynski, A.; McMurray, R.; Gee, G.; Polidan, E.; Johnson, S.; McKeivey, M.; Ennico, K.;

Criticality of Low-Energy Protons in Single-Event Effects Testing of Highly-Scaled Technologies

NASA Technical Reports Server (NTRS)

Pellish, Jonathan Allen; Marshall, Paul W.; Rodbell, K. P.; Gordon, M. S.; LaBel, K. A.; Schwank, J. R.; Dodds, N. A.; Castaneda, C. M.; Berg, M. D.; Kim, H. S.;

Single-event Effect Report for EPC Series eGaN FETs: Proton Testing for SEE and TNID Effects

NASA Technical Reports Server (NTRS)

Scheick, Leif

2014-01-01

Previous testing of the Enhanced Power Conversion (EPC) eGaN FETs showed sensitivity to destructive single-event effects (SEE) effects to heavy ions. The presence of tungsten plugs in the gate area raises concerns that the device may be vulnerable to SEE from protons. Irradiation of biased and unbiased devices with heavy ion has results in some damage suspected of being due to total non-ionizing dose (TNID). Proton irradiation is a better radiation type to study this effect. This study presents the results of testing device with protons for SEE and TNID. No SEE in the EPC2012 device, the most sensitive device to SEE, were seen with 53 MeV protons at several angles. The devices continued to function after 1.5 Mrad (Si) of proton dose with only a slight shift in parameters. These results suggest that gross TNID will not be a factor in using these devices nor suffer from SEE due to protons. However, the device should be tested at with 500 MeV protons to guarantee to immunity proton SEE.

Single event upset susceptibilities of latchup immune CMOS process programmable gate arrays

NASA Astrophysics Data System (ADS)

Koga, R.; Crain, W. R.; Crawford, K. B.; Hansel, S. J.; Lau, D. D.; Tsubota, T. K.

Single event upsets (SEU) and latchup susceptibilities of complementary metal oxide semiconductor programmable gate arrays (CMOS PPGA's) were measured at the Lawrence Berkeley Laboratory 88-in. cyclotron facility with Xe (603 MeV), Cu (290 MeV), and Ar (180 MeV) ion beams. The PPGA devices tested were those which may be used in space. Most of the SEU measurements were taken with a newly constructed tester called the Bus Access Storage and Comparison System (BASACS) operating via a Macintosh II computer. When BASACS finds that an output does not match a prerecorded pattern, the state of all outputs, position in the test cycle, and other necessary information is transmitted and stored in the Macintosh. The upset rate was kept between 1 and 3 per second. After a sufficient number of errors are stored, the test is stopped and the total fluence of particles and total errors are recorded. The device power supply current was closely monitored to check for occurrence of latchup. Results of the tests are presented, indicating that some of the PPGA's are good candidates for selected space applications.

The effects of heavy ion radiation on digital micromirror device performance

NASA Astrophysics Data System (ADS)

Travinsky, Anton; Vorobiev, Dmitry; Raisanen, Alan D.; Pellish, Jonathan; Ninkov, Zoran; Robberto, Massimo; Heap, Sara

2016-02-01

There is a need for a space-suitable solution to the selection of targets to be observed in astronomical multiobject spectrometers (MOS). A few digital micromirror device (DMD) - based prototype MOS have been developed for use at ground observatories, However their main use will come in deploying a space based mission. The question of DMD performance under in-orbit radiation remains unanswered. DMDs were tested under accelerated heavy-ion radiation (with the control electronics shielded from radiation), with a focus on detection of single-event effects (SEEs) including latch-up events. Testing showed that DMDs are sensitive to non-destructive ion-induced state changes; however, all SEEs were cleared with a soft reset (that is, sending a new pattern to the device). The DMDs did not experience single-event induced permanent damage or functional changes that required a hard reset (power cycle), even at high ion fluences. This suggests that the SSE rate burden will be manageable for a DMD-based instrument when exposed to solar particle fluxes and cosmic rays on orbit.

Proton Testing of nVidia GTX 1050 GPU

NASA Technical Reports Server (NTRS)

Wyrwas, E. J.

2017-01-01

Single-Event Effects (SEE) testing was conducted on the nVidia GTX 1050 Graphics Processor Unit (GPU); herein referred to as device under test (DUT). Testing was conducted at Massachusetts General Hospitals (MGH) Francis H. Burr Proton Therapy Center on April 9th, 2017 using 200-MeV protons. This testing trip was purposed to provide a baseline assessment of the radiation susceptibility of the DUT as no previous testing had been conducted on this component.

Proton Testing of nVidia Jetson TX1

NASA Technical Reports Server (NTRS)

Wyrwas, Edward J.

2017-01-01

Single-Event Effects (SEE) testing was conducted on the nVidia Jetson TX1 System on Chip (SOC); herein referred to as device under test (DUT). Testing was conducted at Massachusetts General Hospitals (MGH) Francis H. Burr Proton Therapy Center on October 16th, 2016 using 200MeV protons. This testing trip was purposed to provide a baseline assessment of the radiation susceptibility of the DUT as no previous testing had been conducted on this component.

Improved event positioning in a gamma ray detector using an iterative position-weighted centre-of-gravity algorithm.

PubMed

Liu, Chen-Yi; Goertzen, Andrew L

2013-07-21

An iterative position-weighted centre-of-gravity algorithm was developed and tested for positioning events in a silicon photomultiplier (SiPM)-based scintillation detector for positron emission tomography. The algorithm used a Gaussian-based weighting function centred at the current estimate of the event location. The algorithm was applied to the signals from a 4 × 4 array of SiPM detectors that used individual channel readout and a LYSO:Ce scintillator array. Three scintillator array configurations were tested: single layer with 3.17 mm crystal pitch, matched to the SiPM size; single layer with 1.5 mm crystal pitch; and dual layer with 1.67 mm crystal pitch and a ½ crystal offset in the X and Y directions between the two layers. The flood histograms generated by this algorithm were shown to be superior to those generated by the standard centre of gravity. The width of the Gaussian weighting function of the algorithm was optimized for different scintillator array setups. The optimal width of the Gaussian curve was found to depend on the amount of light spread. The algorithm required less than 20 iterations to calculate the position of an event. The rapid convergence of this algorithm will readily allow for implementation on a front-end detector processing field programmable gate array for use in improved real-time event positioning and identification.

Reaction times to weak test lights. [psychophysics biological model

NASA Technical Reports Server (NTRS)

Wandell, B. A.; Ahumada, P.; Welsh, D.

1984-01-01

Maloney and Wandell (1984) describe a model of the response of a single visual channel to weak test lights. The initial channel response is a linearly filtered version of the stimulus. The filter output is randomly sampled over time. Each time a sample occurs there is some probability increasing with the magnitude of the sampled response - that a discrete detection event is generated. Maloney and Wandell derive the statistics of the detection events. In this paper a test is conducted of the hypothesis that the reaction time responses to the presence of a weak test light are initiated at the first detection event. This makes it possible to extend the application of the model to lights that are slightly above threshold, but still within the linear operating range of the visual system. A parameter-free prediction of the model proposed by Maloney and Wandell for lights detected by this statistic is tested. The data are in agreement with the prediction.

Full-Waveform Envelope Templates for Low Magnitude Discrimination and Yield Estimation at Local and Regional Distances with Application to the North Korean Nuclear Tests

NASA Astrophysics Data System (ADS)

Yoo, S. H.

2017-12-01

Monitoring seismologists have successfully used seismic coda for event discrimination and yield estimation for over a decade. In practice seismologists typically analyze long-duration, S-coda signals with high signal-to-noise ratios (SNR) at regional and teleseismic distances, since the single back-scattering model reasonably predicts decay of the late coda. However, seismic monitoring requirements are shifting towards smaller, locally recorded events that exhibit low SNR and short signal lengths. To be successful at characterizing events recorded at local distances, we must utilize the direct-phase arrivals, as well as the earlier part of the coda, which is dominated by multiple forward scattering. To remedy this problem, we have developed a new hybrid method known as full-waveform envelope template matching to improve predicted envelope fits over the entire waveform and account for direct-wave and early coda complexity. We accomplish this by including a multiple forward-scattering approximation in the envelope modeling of the early coda. The new hybrid envelope templates are designed to fit local and regional full waveforms and produce low-variance amplitude estimates, which will improve yield estimation and discrimination between earthquakes and explosions. To demonstrate the new technique, we applied our full-waveform envelope template-matching method to the six known North Korean (DPRK) underground nuclear tests and four aftershock events following the September 2017 test. We successfully discriminated the event types and estimated the yield for all six nuclear tests. We also applied the same technique to the 2015 Tianjin explosions in China, and another suspected low-yield explosion at the DPRK test site on May 12, 2010. Our results show that the new full-waveform envelope template-matching method significantly improves upon longstanding single-scattering coda prediction techniques. More importantly, the new method allows monitoring seismologists to extend coda-based techniques to lower magnitude thresholds and low-yield local explosions.

Monte Carlo event generators in atomic collisions: A new tool to tackle the few-body dynamics

NASA Astrophysics Data System (ADS)

Ciappina, M. F.; Kirchner, T.; Schulz, M.

2010-04-01

We present a set of routines to produce theoretical event files, for both single and double ionization of atoms by ion impact, based on a Monte Carlo event generator (MCEG) scheme. Such event files are the theoretical counterpart of the data obtained from a kinematically complete experiment; i.e. they contain the momentum components of all collision fragments for a large number of ionization events. Among the advantages of working with theoretical event files is the possibility to incorporate the conditions present in a real experiment, such as the uncertainties in the measured quantities. Additionally, by manipulating them it is possible to generate any type of cross sections, specially those that are usually too complicated to compute with conventional methods due to a lack of symmetry. Consequently, the numerical effort of such calculations is dramatically reduced. We show examples for both single and double ionization, with special emphasis on a new data analysis tool, called four-body Dalitz plots, developed very recently. Program summaryProgram title: MCEG Catalogue identifier: AEFV_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEFV_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 2695 No. of bytes in distributed program, including test data, etc.: 18 501 Distribution format: tar.gz Programming language: FORTRAN 77 with parallelization directives using scripting Computer: Single machines using Linux and Linux servers/clusters (with cores with any clock speed, cache memory and bits in a word) Operating system: Linux (any version and flavor) and FORTRAN 77 compilers Has the code been vectorised or parallelized?: Yes RAM: 64-128 kBytes (the codes are very cpu intensive) Classification: 2.6 Nature of problem: The code deals with single and double ionization of atoms by ion impact. Conventional theoretical approaches aim at a direct calculation of the corresponding cross sections. This has the important shortcoming that it is difficult to account for the experimental conditions when comparing results to measured data. In contrast, the present code generates theoretical event files of the same type as are obtained in a real experiment. From these event files any type of cross sections can be easily extracted. The theoretical schemes are based on distorted wave formalisms for both processes of interest. Solution method: The codes employ a Monte Carlo Event Generator based on theoretical formalisms to generate event files for both single and double ionization. One of the main advantages of having access to theoretical event files is the possibility of adding the conditions present in real experiments (parameter uncertainties, environmental conditions, etc.) and to incorporate additional physics in the resulting event files (e.g. elastic scattering or other interactions absent in the underlying calculations). Additional comments: The computational time can be dramatically reduced if a large number of processors is used. Since the codes has no communication between processes it is possible to achieve an efficiency of a 100% (this number certainly will be penalized by the queuing waiting time). Running time: Times vary according to the process, single or double ionization, to be simulated, the number of processors and the type of theoretical model. The typical running time is between several hours and up to a few weeks.

DETECTORS AND EXPERIMENTAL METHODS: Equivalent properties of single event burnout induced by different sources

NASA Astrophysics Data System (ADS)

Yang, Shi-Yu; Cao, Zhou; Da, Dao-An; Xue, Yu-Xiong

2009-05-01

The experimental results of single event burnout induced by heavy ions and 252Cf fission fragments in power MOSFET devices have been investigated. It is concluded that the characteristics of single event burnout induced by 252Cf fission fragments is consistent to that in heavy ions. The power MOSFET in the “turn-off" state is more susceptible to single event burnout than it is in the “turn-on" state. The thresholds of the drain-source voltage for single event burnout induced by 173 MeV bromine ions and 252Cf fission fragments are close to each other, and the burnout cross section is sensitive to variation of the drain-source voltage above the threshold of single event burnout. In addition, the current waveforms of single event burnouts induced by different sources are similar. Different power MOSFET devices may have different probabilities for the occurrence of single event burnout.

Detecting earthquakes over a seismic network using single-station similarity measures

NASA Astrophysics Data System (ADS)

Bergen, Karianne J.; Beroza, Gregory C.

2018-06-01

New blind waveform-similarity-based detection methods, such as Fingerprint and Similarity Thresholding (FAST), have shown promise for detecting weak signals in long-duration, continuous waveform data. While blind detectors are capable of identifying similar or repeating waveforms without templates, they can also be susceptible to false detections due to local correlated noise. In this work, we present a set of three new methods that allow us to extend single-station similarity-based detection over a seismic network; event-pair extraction, pairwise pseudo-association, and event resolution complete a post-processing pipeline that combines single-station similarity measures (e.g. FAST sparse similarity matrix) from each station in a network into a list of candidate events. The core technique, pairwise pseudo-association, leverages the pairwise structure of event detections in its network detection model, which allows it to identify events observed at multiple stations in the network without modeling the expected moveout. Though our approach is general, we apply it to extend FAST over a sparse seismic network. We demonstrate that our network-based extension of FAST is both sensitive and maintains a low false detection rate. As a test case, we apply our approach to 2 weeks of continuous waveform data from five stations during the foreshock sequence prior to the 2014 Mw 8.2 Iquique earthquake. Our method identifies nearly five times as many events as the local seismicity catalogue (including 95 per cent of the catalogue events), and less than 1 per cent of these candidate events are false detections.

Heavy-Ion Testing of the Freescale Qorivva 32-bit Automotive-Grade MCU

NASA Technical Reports Server (NTRS)

Wilcox, Ted; Seidleck, Christina; Casey, Megan; LaBel, Ken

2016-01-01

We present single-event effects testing results from a commercially-available automotive microcontroller. We discuss the difficulties encountered testing with commercially-provided evaluation boards while attempting to classify the complex and varied failure modes of a modern 32-bit microcontroller. This work also describes some of the possible advantages to using off-the-shelf automotive-grade electronics for low-risk aerospace applications.

Team Update on North American Proton Facilities for Radiation Testing

NASA Technical Reports Server (NTRS)

LaBel, Kenneth A.; Turflinger, Thomas; Haas, Thurman; George, Jeffrey; Moss, Steven; Davis, Scott; Kostic, Andrew; Wie, Brian; Reed, Robert; Guertin, Steven;

Highly specific detection of genetic modification events using an enzyme-linked probe hybridization chip.

PubMed

Zhang, M Z; Zhang, X F; Chen, X M; Chen, X; Wu, S; Xu, L L

2015-08-10

The enzyme-linked probe hybridization chip utilizes a method based on ligase-hybridizing probe chip technology, with the principle of using thio-primers for protection against enzyme digestion, and using lambda DNA exonuclease to cut multiple PCR products obtained from the sample being tested into single-strand chains for hybridization. The 5'-end amino-labeled probe was fixed onto the aldehyde chip, and hybridized with the single-stranded PCR product, followed by addition of a fluorescent-modified probe that was then enzymatically linked with the adjacent, substrate-bound probe in order to achieve highly specific, parallel, and high-throughput detection. Specificity and sensitivity testing demonstrated that enzyme-linked probe hybridization technology could be applied to the specific detection of eight genetic modification events at the same time, with a sensitivity reaching 0.1% and the achievement of accurate, efficient, and stable results.

Radiation Hard 0.13 Micron CMOS Library at IHP

NASA Astrophysics Data System (ADS)

Jagdhold, U.

2013-08-01

To support space applications we have developed an 0.13 micron CMOS library which should be radiation hard up to 200 krad. The article describes the concept to come to a radiation hard digital circuit and was introduces in 2010 [1]. By introducing new radiation hard design rules we will minimize IC-level leakage and single event latch-up (SEL). To reduce single event upset (SEU) we add two p-MOS transistors to all flip flops. For reliability reasons we use double contacts in all library elements. The additional rules and the library elements are integrated in our Cadence mixed signal design kit, “Virtuoso” IC6.1 [2]. A test chip is produced with our in house 0.13 micron BiCMOS technology, see Ref. [3]. As next step we will doing radiation tests according the european space agency (ESA) specifications, see Ref. [4], [5].

Multicasting mesh AER: a scalable assembly approach for reconfigurable neuromorphic structured AER systems. Application to ConvNets.

PubMed

Zamarreno-Ramos, C; Linares-Barranco, A; Serrano-Gotarredona, T; Linares-Barranco, B

2013-02-01

This paper presents a modular, scalable approach to assembling hierarchically structured neuromorphic Address Event Representation (AER) systems. The method consists of arranging modules in a 2D mesh, each communicating bidirectionally with all four neighbors. Address events include a module label. Each module includes an AER router which decides how to route address events. Two routing approaches have been proposed, analyzed and tested, using either destination or source module labels. Our analyses reveal that depending on traffic conditions and network topologies either one or the other approach may result in better performance. Experimental results are given after testing the approach using high-end Virtex-6 FPGAs. The approach is proposed for both single and multiple FPGAs, in which case a special bidirectional parallel-serial AER link with flow control is exploited, using the FPGA Rocket-I/O interfaces. Extensive test results are provided exploiting convolution modules of 64 × 64 pixels with kernels with sizes up to 11 × 11, which process real sensory data from a Dynamic Vision Sensor (DVS) retina. One single Virtex-6 FPGA can hold up to 64 of these convolution modules, which is equivalent to a neural network with 262 × 10(3) neurons and almost 32 million synapses.

Addressing Angular Single-Event Effects in the Estimation of On-Orbit Error Rates

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

Lee, David S.; Swift, Gary M.; Wirthlin, Michael J.

2015-12-01

Our study describes complications introduced by angular direct ionization events on space error rate predictions. In particular, prevalence of multiple-cell upsets and a breakdown in the application of effective linear energy transfer in modern-scale devices can skew error rates approximated from currently available estimation models. Moreover, this paper highlights the importance of angular testing and proposes a methodology to extend existing error estimation tools to properly consider angular strikes in modern-scale devices. Finally, these techniques are illustrated with test data provided from a modern 28 nm SRAM-based device.

Heavy Ion and Proton Tests for Subsystem Upset.

DTIC Science & Technology

1988-03-21

R. Kennerud, P. Measel , and K. Wahlin, "Transient And Total Dose Radiation Properties Of The CMOS/SOS EPIC Chip Set", IEEE Trans. on Nucl. Sci., Vol...NS-30, No. 6, Dec. 1983 .(3) T. L. Criswell, P. R. Measel , and K. L. Wahlin, "Single Event Upset P Testing With Relativistic Heavy Ions", IEEE Trans

A full-angle Monte-Carlo scattering technique including cumulative and single-event Rutherford scattering in plasmas

NASA Astrophysics Data System (ADS)

Higginson, Drew P.

2017-11-01

We describe and justify a full-angle scattering (FAS) method to faithfully reproduce the accumulated differential angular Rutherford scattering probability distribution function (pdf) of particles in a plasma. The FAS method splits the scattering events into two regions. At small angles it is described by cumulative scattering events resulting, via the central limit theorem, in a Gaussian-like pdf; at larger angles it is described by single-event scatters and retains a pdf that follows the form of the Rutherford differential cross-section. The FAS method is verified using discrete Monte-Carlo scattering simulations run at small timesteps to include each individual scattering event. We identify the FAS regime of interest as where the ratio of temporal/spatial scale-of-interest to slowing-down time/length is from 10-3 to 0.3-0.7; the upper limit corresponds to Coulomb logarithm of 20-2, respectively. Two test problems, high-velocity interpenetrating plasma flows and keV-temperature ion equilibration, are used to highlight systems where including FAS is important to capture relevant physics.

SRAM Based Re-programmable FPGA for Space Applications

NASA Technical Reports Server (NTRS)

Wang, J. J.; Sun, J. S.; Cronquist, B. E.; McCollum, J. L.; Speers, T. M.; Plants, W. C.; Katz, R. B.

1999-01-01

An SRAM (static random access memory)-based reprogrammable FPGA (field programmable gate array) is investigated for space applications. A new commercial prototype, named the RS family, was used as an example for the investigation. The device is fabricated in a 0.25 micrometers CMOS technology. Its architecture is reviewed to provide a better understanding of the impact of single event upset (SEU) on the device during operation. The SEU effect of different memories available on the device is evaluated. Heavy ion test data and SPICE simulations are used integrally to extract the threshold LET (linear energy transfer). Together with the saturation cross-section measurement from the layout, a rate prediction is done on each memory type. The SEU in the configuration SRAM is identified as the dominant failure mode and is discussed in detail. The single event transient error in combinational logic is also investigated and simulated by SPICE. SEU mitigation by hardening the memories and employing EDAC (error detection and correction) at the device level are presented. For the configuration SRAM (CSRAM) cell, the trade-off between resistor de-coupling and redundancy hardening techniques are investigated with interesting results. Preliminary heavy ion test data show no sign of SEL (single event latch-up). With regard to ionizing radiation effects, the increase in static leakage current (static I(sub CC)) measured indicates a device tolerance of approximately 50krad(Si).

Analyzing System on A Chip Single Event Upset Responses using Single Event Upset Data, Classical Reliability Models, and Space Environment Data

NASA Technical Reports Server (NTRS)

Berg, Melanie; LaBel, Kenneth; Campola, Michael; Xapsos, Michael

2017-01-01

We are investigating the application of classical reliability performance metrics combined with standard single event upset (SEU) analysis data. We expect to relate SEU behavior to system performance requirements. Our proposed methodology will provide better prediction of SEU responses in harsh radiation environments with confidence metrics. single event upset (SEU), single event effect (SEE), field programmable gate array devises (FPGAs)

Radon backgrounds in the DEAP-1 liquid-argon-based Dark Matter detector

NASA Astrophysics Data System (ADS)

Amaudruz, P.-A.; Batygov, M.; Beltran, B.; Boudjemline, K.; Boulay, M. G.; Cai, B.; Caldwell, T.; Chen, M.; Chouinard, R.; Cleveland, B. T.; Contreras, D.; Dering, K.; Duncan, F.; Ford, R.; Gagnon, R.; Giuliani, F.; Gold, M.; Golovko, V. V.; Gorel, P.; Graham, K.; Grant, D. R.; Hakobyan, R.; Hallin, A. L.; Harvey, P.; Hearns, C.; Jillings, C. J.; Kuźniak, M.; Lawson, I.; Li, O.; Lidgard, J.; Liimatainen, P.; Lippincott, W. H.; Mathew, R.; McDonald, A. B.; McElroy, T.; McFarlane, K.; McKinsey, D.; Muir, A.; Nantais, C.; Nicolics, K.; Nikkel, J.; Noble, T.; O'Dwyer, E.; Olsen, K. S.; Ouellet, C.; Pasuthip, P.; Pollmann, T.; Rau, W.; Retiere, F.; Ronquest, M.; Skensved, P.; Sonley, T.; Tang, J.; Vázquez-Jáuregui, E.; Veloce, L.; Ward, M.

2015-03-01

The DEAP-1 7 kg single phase liquid argon scintillation detector was operated underground at SNOLAB in order to test the techniques and measure the backgrounds inherent to single phase detection, in support of the DEAP-3600 Dark Matter detector. Backgrounds in DEAP are controlled through material selection, construction techniques, pulse shape discrimination, and event reconstruction. This report details the analysis of background events observed in three iterations of the DEAP-1 detector, and the measures taken to reduce them. The 222 Rn decay rate in the liquid argon was measured to be between 16 and 26 μBq kg-1. We found that the background spectrum near the region of interest for Dark Matter detection in the DEAP-1 detector can be described considering events from three sources: radon daughters decaying on the surface of the active volume, the expected rate of electromagnetic events misidentified as nuclear recoils due to inefficiencies in the pulse shape discrimination, and leakage of events from outside the fiducial volume due to imperfect position reconstruction. These backgrounds statistically account for all observed events, and they will be strongly reduced in the DEAP-3600 detector due to its higher light yield and simpler geometry.

Combat Helmet-Headform Coupling Characterized from Blunt Impact Events

DTIC Science & Technology

2011-11-01

Testing was completed on a monorail drop tower to analyze the effect of helmet/headform coupling on the blunt impact behavior of ACH helmets using FMVSS...designates its own methods and test equipment: a drop tower ( monorail or twin- wire), headform (DOT, ISO, NOCSAE), headform CG accelerometer (single or...the more anthropomorphic International Standard Organization (ISO) half headform. Testing was completed on a monorail drop tower to analyze the effect

Optimized breeding strategies for multiple trait integration: I. Minimizing linkage drag in single event introgression.

PubMed

Peng, Ting; Sun, Xiaochun; Mumm, Rita H

2014-01-01

From a breeding standpoint, multiple trait integration (MTI) is a four-step process of converting an elite variety/hybrid for value-added traits (e.g. transgenic events) using backcross breeding, ultimately regaining the performance attributes of the target hybrid along with reliable expression of the value-added traits. In the light of the overarching goal of recovering equivalent performance in the finished conversion, this study focuses on the first step of MTI, single event introgression, exploring the feasibility of marker-aided backcross conversion of a target maize hybrid for 15 transgenic events, incorporating eight events into the female hybrid parent and seven into the male parent. Single event introgression is conducted in parallel streams to convert the recurrent parent (RP) for individual events, with the primary objective of minimizing residual non-recurrent parent (NRP) germplasm, especially in the chromosomal proximity to the event (i.e. linkage drag). In keeping with a defined lower limit of 96.66 % overall RP germplasm recovery (i.e. ≤120 cM NRP germplasm given a genome size of 1,788 cM), a breeding goal for each of the 15 single event conversions was developed: <8 cM of residual NRP germplasm across the genome with ~1 cM in the 20 cM region flanking the event. Using computer simulation, we aimed to identify optimal breeding strategies for single event introgression to achieve this breeding goal, measuring efficiency in terms of number of backcross generations required, marker data points needed, and total population size across generations. Various selection schemes classified as three-stage, modified two-stage, and combined selection conducted from BC1 through BC3, BC4, or BC5 were compared. The breeding goal was achieved with a selection scheme involving five generations of marker-aided backcrossing, with BC1 through BC3 selected for the event of interest and minimal linkage drag at population size of 600, and BC4 and BC5 selected for the event of interest and recovery of the RP germplasm across the genome at population size of 400, with selection intensity of 0.01 for all generations. In addition, strategies for choice of donor parent to facilitate conversion efficiency and quality were evaluated. Two essential criteria for choosing an optimal donor parent for a given RP were established: introgression history showing reduction of linkage drag to ~1 cM in the 20 cM region flanking the event and genetic similarity between the RP and potential donor parents. Computer simulation demonstrated that single event conversions with <8 cM residual NRP germplasm can be accomplished by BC5 with no genetic similarity, by BC4 with 30 % genetic similarity, and by BC3 with 86 % genetic similarity using previously converted RPs as event donors. This study indicates that MTI to produce a 'quality' 15-event-stacked hybrid conversion is achievable. Furthermore, it lays the groundwork for a comprehensive approach to MTI by outlining a pathway to produce appropriate starting materials with which to proceed with event pyramiding and trait fixation before version testing.

Experience with custom processors in space flight applications

NASA Technical Reports Server (NTRS)

Fraeman, M. E.; Hayes, J. R.; Lohr, D. A.; Ballard, B. W.; Williams, R. L.; Henshaw, R. M.

1991-01-01

The Applied Physics Laboratory (APL) has developed a magnetometer instrument for a swedish satellite named Freja with launch scheduled for August 1992 on a Chinese Long March rocket. The magnetometer controller utilized a custom microprocessor designed at APL with the Genesil silicon compiler. The processor evolved from our experience with an older bit-slice design and two prior single chip efforts. The architecture of our microprocessor greatly lowered software development costs because it was optimized to provide an interactive and extensible programming environment hosted by the target hardware. Radiation tolerance of the microprocessor was also tested and was adequate for Freja's mission -- 20 kRad(Si) total dose and very infrequent latch-up and single event upset events.

Single event induced transients in I/O devices - A characterization

NASA Technical Reports Server (NTRS)

Newberry, D. M.; Kaye, D. H.; Soli, G. A.

1990-01-01

The results of single-event upset (SEU) testing performed to evaluate the parametric transients, i.e., amplitude and duration, in several I/O devices, and the impact of these transients are discussed. The failure rate of these devices is dependent on the susceptibility of interconnected devices to the resulting transient change in the output of the I/O device. This failure rate, which is a function of the susceptibility of the interconnected device as well as the SEU response of the I/O device itself, may be significantly different from an upset rate calculated without taking these factors into account. The impact at the system level is discussed by way of an example.

Scaling and Single Event Effects (SEE) Sensitivity

NASA Technical Reports Server (NTRS)

Oldham, Timothy R.

2003-01-01

This paper begins by discussing the potential for scaling down transistors and other components to fit more of them on chips in order to increasing computer processing speed. It also addresses technical challenges to further scaling. Components have been scaled down enough to allow single particles to have an effect, known as a Single Event Effect (SEE). This paper explores the relationship between scaling and the following SEEs: Single Event Upsets (SEU) on DRAMs and SRAMs, Latch-up, Snap-back, Single Event Burnout (SEB), Single Event Gate Rupture (SEGR), and Ion-induced soft breakdown (SBD).

Robust inference for group sequential trials.

PubMed

Ganju, Jitendra; Lin, Yunzhi; Zhou, Kefei

2017-03-01

For ethical reasons, group sequential trials were introduced to allow trials to stop early in the event of extreme results. Endpoints in such trials are usually mortality or irreversible morbidity. For a given endpoint, the norm is to use a single test statistic and to use that same statistic for each analysis. This approach is risky because the test statistic has to be specified before the study is unblinded, and there is loss in power if the assumptions that ensure optimality for each analysis are not met. To minimize the risk of moderate to substantial loss in power due to a suboptimal choice of a statistic, a robust method was developed for nonsequential trials. The concept is analogous to diversification of financial investments to minimize risk. The method is based on combining P values from multiple test statistics for formal inference while controlling the type I error rate at its designated value.This article evaluates the performance of 2 P value combining methods for group sequential trials. The emphasis is on time to event trials although results from less complex trials are also included. The gain or loss in power with the combination method relative to a single statistic is asymmetric in its favor. Depending on the power of each individual test, the combination method can give more power than any single test or give power that is closer to the test with the most power. The versatility of the method is that it can combine P values from different test statistics for analysis at different times. The robustness of results suggests that inference from group sequential trials can be strengthened with the use of combined tests. Copyright © 2017 John Wiley & Sons, Ltd.

Characterizing SRAM Single Event Upset in Terms of Single and Double Node Charge Collection

NASA Technical Reports Server (NTRS)

Black, J. D.; Ball, D. R., II; Robinson, W. H.; Fleetwood, D. M.; Schrimpf, R. D.; Reed, R. A.; Black, D. A.; Warren, K. M.; Tipton, A. D.; Dodd, P. E.;

Single-Event Effect Response of a Commercial ReRAM

NASA Technical Reports Server (NTRS)

Chen, Dakai; Label, Kenneth A.; Kim, Hak; Phan, Anthony; Wilcox, Edward; Buchner, Stephen; Khachatrian, Ani; Roche, Nicolas

2014-01-01

We show heavy ion test results of a commercial production-level ReRAM. The memory array is robust to bit upsets. However the ReRAM system is vulnerable to SEFIs due to upsets in peripheral circuits, including the sense amplifier.

Evaluation of commercial ADC radiation tolerance for accelerator experiments

DOE PAGES

Chen, K.; Chen, H.; Kierstead, J.; ...

2015-08-17

Electronic components used in high energy physics experiments are subjected to a radiation background composed of high energy hadrons, mesons and photons. These particles can induce permanent and transient effects that affect the normal device operation. Ionizing dose and displacement damage can cause chronic damage which disable the device permanently. Transient effects or single event effects are in general recoverable with time intervals that depend on the nature of the failure. The magnitude of these effects is technology dependent with feature size being one of the key parameters. Analog to digital converters are components that are frequently used in detectormore » front end electronics, generally placed as close as possible to the sensing elements to maximize signal fidelity. We report on radiation effects tests conducted on 17 commercially available analog to digital converters and extensive single event effect measurements on specific twelve and fourteen bit ADCs that presented high tolerance to ionizing dose. We discuss mitigation strategies for single event effects (SEE) for their use in the large hadron collider environment.« less

Single-Event Effect Performance of a Conductive-Bridge Memory EEPROM

NASA Technical Reports Server (NTRS)

Chen, Dakai; Wilcox, Edward; Berg, Melanie; Kim, Hak; Phan, Anthony; Figueiredo, Marco; Seidleck, Christina; LaBel, Kenneth

2015-01-01

We investigated the heavy ion single-event effect (SEE) susceptibility of the industry’s first stand-alone memory based on conductive-bridge memory (CBRAM) technology. The device is available as an electrically erasable programmable read-only memory (EEPROM). We found that single-event functional interrupt (SEFI) is the dominant SEE type for each operational mode (standby, dynamic read, and dynamic write/read). SEFIs occurred even while the device is statically biased in standby mode. Worst case SEFIs resulted in errors that filled the entire memory space. Power cycle did not always clear the errors. Thus the corrupted cells had to be reprogrammed in some cases. The device is also vulnerable to bit upsets during dynamic write/read tests, although the frequency of the upsets are relatively low. The linear energy transfer threshold for cell upset is between 10 and 20 megaelectron volts per square centimeter per milligram, with an upper limit cross section of 1.6 times 10(sup -11) square centimeters per bit (95 percent confidence level) at 10 megaelectronvolts per square centimeter per milligram. In standby mode, the CBRAM array appears invulnerable to bit upsets.

Frequency Dependence of Single-Event Upset in Highly Advanced PowerPC Microprocessors

NASA Technical Reports Server (NTRS)

Irom, Farokh; Farmanesh, Farhad; White, Mark; Kouba, Coy K.

2006-01-01

Single-event upset effects from heavy ions were measured for Motorola silicon-on-insulator (SOI) microprocessor with 90 nm feature sizes at three frequencies of 500, 1066 and 1600 MHz. Frequency dependence of single-event upsets is discussed. The results of our studies suggest the single-event upset in registers and D-Cache tend to increase with frequency. This might have important implications for the overall single-event upset trend as technology moves toward higher frequencies.

Design Tools for Reconfigurable Hardware in Orbit (RHinO)

NASA Technical Reports Server (NTRS)

French, Mathew; Graham, Paul; Wirthlin, Michael; Larchev, Gregory; Bellows, Peter; Schott, Brian

2004-01-01

The Reconfigurable Hardware in Orbit (RHinO) project is focused on creating a set of design tools that facilitate and automate design techniques for reconfigurable computing in space, using SRAM-based field-programmable-gate-array (FPGA) technology. These tools leverage an established FPGA design environment and focus primarily on space effects mitigation and power optimization. The project is creating software to automatically test and evaluate the single-event-upsets (SEUs) sensitivities of an FPGA design and insert mitigation techniques. Extensions into the tool suite will also allow evolvable algorithm techniques to reconfigure around single-event-latchup (SEL) events. In the power domain, tools are being created for dynamic power visualiization and optimization. Thus, this technology seeks to enable the use of Reconfigurable Hardware in Orbit, via an integrated design tool-suite aiming to reduce risk, cost, and design time of multimission reconfigurable space processors using SRAM-based FPGAs.

Single Event Effects Test Results for Advanced Field Programmable Gate Arrays

NASA Technical Reports Server (NTRS)

Allen, Gregory R.; Swift, Gary M.

2006-01-01

Reconfigurable Field Programmable Gate Arrays (FPGAs) from Altera and Actel and an FPGA-based quick-turnApplication Specific Integrated Circuit (ASIC) from Altera were subjected to single-event testing using heavy ions. Both Altera devices (Stratix II and HardCopy II) exhibited a low latchup threshold (below an LET of 3 MeV-cm2/mg) and thus are not recommended for applications in the space radiation environment. The flash-based Actel ProASIC Plus device did not exhibit latchup to an effective LET of 75 MeV-cm2/mg at room temperature. In addition, these tests did not show flash cell charge loss (upset) or retention damage. Upset characterization of the design-level flip-flops yielded an LET threshold below 10 MeV-cm2/mg and a high LET cross section of about lxlO-6 cm2/bit for storing ones and about lxl0-7 cm2/bit for storing zeros . Thus, the ProASIC device may be suitable for critical flight applications with appropriate triple modular redundancy mitigation techniques.

Compendium of Current Total Ionizing Dose and Displacement Damage Results from NASA Goddard Space Flight Center and NASA Electronic Parts and Packaging Program

NASA Technical Reports Server (NTRS)

Topper, Alyson D.; Campola, Michael J.; Chen, Dakai; Casey, Megan C.; Yau, Ka-Yen; Cochran, Donna J.; Label, Kenneth A.; Ladbury, Raymond L.; Mondy, Timothy K.; O'Bryan, Martha V.;

A prospective, randomized, double-blind trial of intranasal dexmedetomidine and oral chloral hydrate for sedated auditory brainstem response (ABR) testing.

PubMed

Reynolds, Jason; Rogers, Amber; Medellin, Eduardo; Guzman, Jonathan A; Watcha, Mehernoor F

2016-03-01

Dexmedetomidine is increasingly used by various routes for pediatric sedation. However, there are few randomized controlled trials comparing the efficacy of dexmedetomidine to other commonly used sedatives. To compare the efficacy of sedation with intranasal dexmedetomidine to oral chloral hydrate for auditory brainstem response (ABR) testing. In this double-blind, double-dummy study, children undergoing ABR testing were randomized to receive intranasal dexmedetomidine 3 mcg · kg(-1) plus oral placebo (Group IN DEX) or oral chloral hydrate 50 mg · kg(-1) plus intranasal saline placebo (Group CH). We recorded demographic data, times from sedative administration to start and completion of testing, quality of sedation, occurrence of predefined adverse events, discharge times, and return to baseline activity on the day of testing. Testing completion rates with a single dose of medication were higher in the IN DEX group (89% vs 66% for CH, odds ratio with 95% confidence intervals 4.04 [1.3-12.6], P = 0.018). The median [95% CI)] time to successful testing start was shorter (25 [20-29] min vs 30 [20-49] min for IN DEX and CH, respectively, log rank test P = 0.02) and the proportion of children whose parents reported a return to baseline activity on the day of testing was greater for the IN DEX than the CH group (89% vs 64%, OR [95% CI] 4.71 [1.34-16.6], P = 0.02). There were no major adverse events in either group and no significant differences in the incidence of minor events. Intranasal dexmedetomidine is an effective alternative to oral chloral hydrate sedation for ABR testing, with the advantages of a higher incidence of testing completion with a single dose, shorter time to desired sedation level, and with significantly more patients reported to return to baseline activity on the same day. © 2016 John Wiley & Sons Ltd.

Search for Correlated Fluctuations in the Beta+ Decay of Na-22

NASA Astrophysics Data System (ADS)

Silverman, M. P.; Strange, W.

2008-10-01

Claims for a ``cosmogenic'' force that correlates otherwise independent stochastic events have been made for at least 10 years, based largely on visual inspection of time series of histograms whose shapes were interpreted as suggestive of recurrent patterns with semi-diurnal, diurnal, and monthly periods. Building on our earlier work to test randomness of different nuclear decay processes, we have searched for correlations in the time-series of coincident positron-electron annihilations deriving from beta+ decay of Na-22. Disintegrations were counted within a narrow time window over a period of 7 days, leading to a time series of more than 1 million events. Statistical tests were performed on the raw time series, its correlation function, and its Fourier transform to search for cyclic correlations indicative of quantum-mechanical violating deviations from Poisson statistics. The time series was then partitioned into a sequence of 167 ``bags'' each of 8192 events. A histogram was made of the events of each bag, where contiguous frequency classes differed by a single count. The chronological sequence of histograms was then tested for correlations within classes. In all cases the results of the tests were in accord with statistical control, giving no evidence of correlated fluctuations.

Importance of ion energy on SEU in CMOS SRAMs

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

Dodd, P.E.; Shaneyfelt, M.R.; Sexton, F.W.

1998-03-01

The single-event upset (SEU) responses of 16 Kbit to 1 Mbit SRAMs irradiated with low and high-energy heavy ions are reported. Standard low-energy heavy ion tests appear to be sufficiently conservative for technologies down to 0.5 {micro}m.

A comparative study of calcium absorption following a single serving administration of calcium carbonate powder versus calcium citrate tablets in healthy premenopausal women

PubMed Central

Wang, Haiyuan; Bua, Peter; Capodice, Jillian

2014-01-01

Background Calcium is an essential mineral often taken as a daily, long-term nutritional supplement. Data suggests that once-daily dosing is important with regard to long-term compliance of both drugs and nutritional supplements. Objective This study was undertaken to compare the bioavailability of a single serving of two calcium supplements in healthy, premenopausal women. Design A two-period, crossover bioavailability study of a single serving of calcium citrate tablets (two tablets=500 mg calcium) versus a single serving of calcium carbonate powder (one packet of powder=1,000 mg calcium) was performed in healthy women aged between 25 and 45. All subjects were on a calcium-restricted diet 7 days prior to testing and fasted for 12 h before being evaluated at 0, 1, 2, and 4 h after oral administration of the test agents. Blood measurements for total and ionized calcium and parathyroid hormone were performed and adverse events were monitored. Results Twenty-three women were evaluable with a mean age of 33.2±8.71. Results showed that administration of a single serving of a calcium carbonate powder resulted in greater absorption in total and ionized calcium versus a single serving of calcium citrate tablets at 4 h (4.25±0.21 vs. 4.16±0.16, p=0.001). There were minimal side effects and no reported serious adverse events. Conclusions This study shows that a single serving of a calcium carbonate powder is more bioavailable than a single serving of calcium citrate tablets. This may be beneficial for long-term compliance. PMID:24772062

Evaluation of the Radiation Susceptibility of a 3D NAND Flash Memory

NASA Technical Reports Server (NTRS)

Chen, Dakai; Wilcox, Edward; Ladbury, Raymond; Seidleck, Christina; Kim, Hak; Phan, Anthony; LaBel, Kenneth

2017-01-01

We evaluated the heavy ion and proton-induced single-event effects (SEE) for a 3D NAND flash. The 3D NAND showed similar single-event upset (SEU) sensitivity to a planar NAND of similar density and performance in the multiple-cell level (MLC) storage mode. However, the single-level-cell (SLC) storage mode of the 3D NAND showed significantly reduced SEU susceptibility. Additionally, the 3D NAND showed less MBU susceptibility than the planar NAND, with reduced number of upset bits per byte and reduced cross sections overall. However, the 3D architecture exhibited angular sensitivities for both base and face angles, reflecting the anisotropic nature of the SEU vulnerability in space. Furthermore, the SEU cross section decreased with increasing fluence for both the 3D NAND and the latest generation planar NAND, indicating a variable upset rate for a space mission. These unique characteristics introduce complexity to traditional ground irradiation test procedures.

Modeling the effects of low-LET cosmic rays on electronic components.

PubMed

Keating, A; Goncalves, P; Pimenta, M; Brogueira, P; Zadeh, A; Daly, E

2012-08-01

The effects of cosmic radiation in single cells, organic tissues and electronics are a major concern for space exploration and manned missions. Standard heavy ions radiation tests employ ion cocktails with energy of the order of 10 MeV per nucleon and with a linear energy transfer ranging from a few MeV cm(2) mg(-1) to hundreds of MeV cm(2) mg(-1). In space, cosmic rays show significant fluxes at energies up to the order of GeV per nucleon. The present work aims at investigating single event damage due to low-, high- and very-high-energy ions. The European Space Agency reference single event upset monitor data are used to support the discussion. Finally, the effect of ionization induced directly by primary particles and ionization induced by recoils produced in an electronic device is investigated for different types of devices.

Classification of single-trial auditory events using dry-wireless EEG during real and motion simulated flight.

PubMed

Callan, Daniel E; Durantin, Gautier; Terzibas, Cengiz

2015-01-01

Application of neuro-augmentation technology based on dry-wireless EEG may be considerably beneficial for aviation and space operations because of the inherent dangers involved. In this study we evaluate classification performance of perceptual events using a dry-wireless EEG system during motion platform based flight simulation and actual flight in an open cockpit biplane to determine if the system can be used in the presence of considerable environmental and physiological artifacts. A passive task involving 200 random auditory presentations of a chirp sound was used for evaluation. The advantage of this auditory task is that it does not interfere with the perceptual motor processes involved with piloting the plane. Classification was based on identifying the presentation of a chirp sound vs. silent periods. Evaluation of Independent component analysis (ICA) and Kalman filtering to enhance classification performance by extracting brain activity related to the auditory event from other non-task related brain activity and artifacts was assessed. The results of permutation testing revealed that single trial classification of presence or absence of an auditory event was significantly above chance for all conditions on a novel test set. The best performance could be achieved with both ICA and Kalman filtering relative to no processing: Platform Off (83.4% vs. 78.3%), Platform On (73.1% vs. 71.6%), Biplane Engine Off (81.1% vs. 77.4%), and Biplane Engine On (79.2% vs. 66.1%). This experiment demonstrates that dry-wireless EEG can be used in environments with considerable vibration, wind, acoustic noise, and physiological artifacts and achieve good single trial classification performance that is necessary for future successful application of neuro-augmentation technology based on brain-machine interfaces.

Single Event Effects (SEE) Testing: Practical Approach to Test Plans

NASA Technical Reports Server (NTRS)

LaBel, Kenneth A.; Pellish, Jonathan Allen; Berg, Melanie D.

2014-01-01

While standards and guidelines for performing SEE testing have existed for several decades, guidance for developing SEE test plans has not been as easy to find. In this presentation, the variety of areas that need to be considered ranging from resource issues (funds, personnel, schedule) to extremely technical challenges (particle interaction and circuit application), shall be discussed. Note: we consider the approach outlined here as a "living" document: Mission-specific constraints and new technology related issues always need to be taken into account.

Single Event Test Methodologies and System Error Rate Analysis for Triple Modular Redundant Field Programmable Gate Arrays

NASA Technical Reports Server (NTRS)

Allen, Gregory; Edmonds, Larry D.; Swift, Gary; Carmichael, Carl; Tseng, Chen Wei; Heldt, Kevin; Anderson, Scott Arlo; Coe, Michael

2010-01-01

We present a test methodology for estimating system error rates of Field Programmable Gate Arrays (FPGAs) mitigated with Triple Modular Redundancy (TMR). The test methodology is founded in a mathematical model, which is also presented. Accelerator data from 90 nm Xilins Military/Aerospace grade FPGA are shown to fit the model. Fault injection (FI) results are discussed and related to the test data. Design implementation and the corresponding impact of multiple bit upset (MBU) are also discussed.

A progressive 5-week exercise therapy program leads to significant improvement in knee function early after anterior cruciate ligament injury.

PubMed

Eitzen, Ingrid; Moksnes, Håvard; Snyder-Mackler, Lynn; Risberg, May Arna

2010-11-01

Prospective cohort study without a control group. Firstly, to present our 5-week progressive exercise therapy program in the early stage after anterior cruciate ligament (ACL) injury. Secondly, to evaluate changes in knee function after completion of the program for patients with ACL injury in general and also when classified as potential copers or noncopers, and, finally, to examine potential adverse events. Few studies concerning early-stage ACL rehabilitation protocols exist. Consequently, little is known about the tolerance for, and outcomes from, short-term exercise therapy programs in the early stage after injury. One-hundred patients were included in a 5-week progressive exercise therapy program, within 3 months after injury. Knee function before and after completion of the program was evaluated from isokinetic quadriceps and hamstrings muscle strength tests, 4 single-leg hop tests, 2 different self-assessment questionnaires, and a global rating of knee function. A 2-way mixed-model analysis of variance was conducted to evaluate changes from pretest to posttest for the limb symmetry index for muscle strength and single-leg hop tests, and the change in scores for the patient-reported questionnaires. In addition, absolute values and the standardized response mean for muscle strength and single-leg hop tests were calculated at pretest and posttest for the injured and uninjured limb. Adverse events during the 5-week period were recorded. The progressive 5-week exercise therapy program led to significant improvements (P<.05) in knee function from pretest to posttest both for patients classified as potential copers and noncopers. Standardized response mean values for changes in muscle strength and single-leg hop performance from pretest to posttest for the injured limb were moderate to strong (0.49-0.84), indicating the observed improvements to be clinically relevant. Adverse events occurred in 3.9% of the patients. Short-term progressive exercise therapy programs are well tolerated and should be incorporated in early-stage ACL rehabilitation, either to improve knee function before ACL reconstruction or as a first step in further nonoperative management. Therapy, level 2b.

The role of renin-angiotensin-aldosterone system genes in the progression of chronic kidney disease: findings from the Chronic Renal Insufficiency Cohort (CRIC) study.

PubMed

Kelly, Tanika N; Raj, Dominic; Rahman, Mahboob; Kretzler, Matthias; Kallem, Radhakrishna R; Ricardo, Ana C; Rosas, Sylvia E; Tao, Kaixiang; Xie, Dawei; Hamm, Lotuce Lee; He, Jiang

2015-10-01

We conducted single-marker, gene- and pathway-based analyses to examine the association between renin-angiotensin-aldosterone system (RAAS) variants and chronic kidney disease (CKD) progression among Chronic Renal Insufficiency Cohort study participants. A total of 1523 white and 1490 black subjects were genotyped for 490 single nucleotide polymorphisms (SNPs) in 12 RAAS genes as part of the ITMAT-Broad-CARe array. CKD progression phenotypes included decline in estimated glomerular filtration rate (eGFR) over time and the occurrence of a renal disease event, defined as incident end-stage renal disease or halving of eGFR from baseline. Mixed-effects models were used to examine SNP associations with eGFR decline, while Cox proportional hazards models tested SNP associations with renal events. Gene- and pathway-based analyses were conducted using the truncated product method. All analyses were stratified by race, and a Bonferroni correction was applied to adjust for multiple testing. Among white and black participants, eGFR declined an average of 1.2 and 2.3 mL/min/1.73 m(2)/year, respectively, while renal events occurred in a respective 11.5 and 24.9% of participants. We identified strong gene- and pathway-based associations with CKD progression. The AGT and RENBP genes were consistently associated with risk of renal events in separate analyses of white and black participants (both P < 1.00 × 10(-6)). Driven by the significant gene-based findings, the entire RAAS pathway was also associated with renal events in both groups (both P < 1.00 × 10(-6)). No single-marker associations with CKD progression were observed. The current study provides strong evidence for a role of the RAAS in CKD progression. © The Author 2015. Published by Oxford University Press on behalf of ERA-EDTA. All rights reserved.

The role of renin–angiotensin–aldosterone system genes in the progression of chronic kidney disease: findings from the Chronic Renal Insufficiency Cohort (CRIC) study

PubMed Central

Kelly, Tanika N.; Raj, Dominic; Rahman, Mahboob; Kretzler, Matthias; Kallem, Radhakrishna R.; Ricardo, Ana C.; Rosas, Sylvia E.; Tao, Kaixiang; Xie, Dawei; Hamm, Lotuce Lee; He, Jiang; Appel, J.; Feldman, Harold I.; Go, Alan S.; Kusek, John W.; Lash, James P.; Ojo, Akinlolu; Townsend, Raymond R.

2015-01-01

Background We conducted single-marker, gene- and pathway-based analyses to examine the association between renin–angiotensin–aldosterone system (RAAS) variants and chronic kidney disease (CKD) progression among Chronic Renal Insufficiency Cohort study participants. Methods A total of 1523 white and 1490 black subjects were genotyped for 490 single nucleotide polymorphisms (SNPs) in 12 RAAS genes as part of the ITMAT-Broad-CARe array. CKD progression phenotypes included decline in estimated glomerular filtration rate (eGFR) over time and the occurrence of a renal disease event, defined as incident end-stage renal disease or halving of eGFR from baseline. Mixed-effects models were used to examine SNP associations with eGFR decline, while Cox proportional hazards models tested SNP associations with renal events. Gene- and pathway-based analyses were conducted using the truncated product method. All analyses were stratified by race, and a Bonferroni correction was applied to adjust for multiple testing. Results Among white and black participants, eGFR declined an average of 1.2 and 2.3 mL/min/1.73 m2/year, respectively, while renal events occurred in a respective 11.5 and 24.9% of participants. We identified strong gene- and pathway-based associations with CKD progression. The AGT and RENBP genes were consistently associated with risk of renal events in separate analyses of white and black participants (both P < 1.00 × 10−6). Driven by the significant gene-based findings, the entire RAAS pathway was also associated with renal events in both groups (both P < 1.00 × 10−6). No single-marker associations with CKD progression were observed. Conclusions The current study provides strong evidence for a role of the RAAS in CKD progression. PMID:25906781

Experimental setup for Single Event Effects at the São Paulo 8UD Pelletron Accelerator

NASA Astrophysics Data System (ADS)

Aguiar, V. A. P.; Added, N.; Medina, N. H.; Macchione, E. L. A.; Tabacniks, M. H.; Aguirre, F. R.; Silveira, M. A. G.; Santos, R. B. B.; Seixas, L. E.

2014-08-01

In this work we present an experimental setup mounted in one of the beam lines at the São Paulo 8UD Pelletron Accelerator in order to study Single Event Effects in electronic devices. The basic idea is to use elastic scattering collisions to achieve a low-flux with a high-uniformity ion beam to irradiate several devices. 12C, 16O, 28Si, 35Cl and 63Cu beams were used to test the experimental setup. In this system it is possible to use efficiently LET values of 17 MeV/mg/cm2 for an external beam arrangement and up to 32 MeV/mg/cm2 for in-vacuum irradiation.

Simulating Chemical-Induced Injury Using Virtual Hepatic Tissues

EPA Science Inventory

Chemical-induced liver injury involves a dynamic sequence of events that span multiple levels of biological organization. Current methods for testing the toxicity of a single chemical can cost millions of dollars, take up to two years and sacrifice thousands of animals. It is dif...

A full-angle Monte-Carlo scattering technique including cumulative and single-event Rutherford scattering in plasmas [Theory of cumulative large-angle collisions in plasmas

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

Higginson, Drew P.

Here, we describe and justify a full-angle scattering (FAS) method to faithfully reproduce the accumulated differential angular Rutherford scattering probability distribution function (pdf) of particles in a plasma. The FAS method splits the scattering events into two regions. At small angles it is described by cumulative scattering events resulting, via the central limit theorem, in a Gaussian-like pdf; at larger angles it is described by single-event scatters and retains a pdf that follows the form of the Rutherford differential cross-section. The FAS method is verified using discrete Monte-Carlo scattering simulations run at small timesteps to include each individual scattering event.more » We identify the FAS regime of interest as where the ratio of temporal/spatial scale-of-interest to slowing-down time/length is from 10 -3 to 0.3–0.7; the upper limit corresponds to Coulomb logarithm of 20–2, respectively. Two test problems, high-velocity interpenetrating plasma flows and keV-temperature ion equilibration, are used to highlight systems where including FAS is important to capture relevant physics.« less

A full-angle Monte-Carlo scattering technique including cumulative and single-event Rutherford scattering in plasmas [Theory of cumulative large-angle collisions in plasmas

DOE PAGES

Higginson, Drew P.

2017-08-12

Here, we describe and justify a full-angle scattering (FAS) method to faithfully reproduce the accumulated differential angular Rutherford scattering probability distribution function (pdf) of particles in a plasma. The FAS method splits the scattering events into two regions. At small angles it is described by cumulative scattering events resulting, via the central limit theorem, in a Gaussian-like pdf; at larger angles it is described by single-event scatters and retains a pdf that follows the form of the Rutherford differential cross-section. The FAS method is verified using discrete Monte-Carlo scattering simulations run at small timesteps to include each individual scattering event.more » We identify the FAS regime of interest as where the ratio of temporal/spatial scale-of-interest to slowing-down time/length is from 10 -3 to 0.3–0.7; the upper limit corresponds to Coulomb logarithm of 20–2, respectively. Two test problems, high-velocity interpenetrating plasma flows and keV-temperature ion equilibration, are used to highlight systems where including FAS is important to capture relevant physics.« less

Vulnerability, life events and depression amongst Moslem Malaysian women: comparing those married and those divorced or separated.

PubMed

Abdul Kadir, Nor Ba'yah; Bifulco, Antonia

2011-09-01

The experiences of married and single mothers were compared in an investigation of psychosocial vulnerability, stress and depression in a community-based study of Moslem mothers in Malaysia. For the first time, a model of vulnerability-provoking agent originally developed by Brown et al. in the UK was tested in a Malaysian context. A cross-sectional study was carried out in the district of Johor Bahru, Malaysia. Of the 1,200 women approached from membership of community associations, 1,002 (84%) completed the questionnaires. Severe life events Recent Life Events Questionnaire (Brugha and Cragg in Acta Psychiatr Scand 82:77-81, 1990) and psychosocial vulnerability (VDQ) (Moran et al. in Br J Clin Psychol 40:411-427, 2001) were used to measure vulnerability factors. Depression was measured by the General Health Questionnaire (GHQ-30) (Havenaar et al. in Soc Psychiatry Psychiatr Epidemiol 43:209-215, 2008). Single mothers had significantly higher rates of depression than those married (60.5 vs. 39.5%), as well as higher rates of severe life events and Negative Elements in Close Relationships (lack of support and conflict with children). However, married mothers had greater Negative Evaluation of Self. The two vulnerability factors were correlated to each other and to severe life events and social adversity. Logistic regression showed an interaction between severe life events in the material and relationship domains and joint vulnerability for depression outcome. The results are discussed in relation to the low recognition of psychosocial risks for depression in single mothers in Malaysia, as well as lack of appropriate services.

Detection of change points in underlying earthquake rates, with application to global mega-earthquakes

NASA Astrophysics Data System (ADS)

Touati, Sarah; Naylor, Mark; Main, Ian

2016-02-01

The recent spate of mega-earthquakes since 2004 has led to speculation of an underlying change in the global `background' rate of large events. At a regional scale, detecting changes in background rate is also an important practical problem for operational forecasting and risk calculation, for example due to volcanic processes, seismicity induced by fluid injection or withdrawal, or due to redistribution of Coulomb stress after natural large events. Here we examine the general problem of detecting changes in background rate in earthquake catalogues with and without correlated events, for the first time using the Bayes factor as a discriminant for models of varying complexity. First we use synthetic Poisson (purely random) and Epidemic-Type Aftershock Sequence (ETAS) models (which also allow for earthquake triggering) to test the effectiveness of many standard methods of addressing this question. These fall into two classes: those that evaluate the relative likelihood of different models, for example using Information Criteria or the Bayes Factor; and those that evaluate the probability of the observations (including extreme events or clusters of events) under a single null hypothesis, for example by applying the Kolmogorov-Smirnov and `runs' tests, and a variety of Z-score tests. The results demonstrate that the effectiveness among these tests varies widely. Information Criteria worked at least as well as the more computationally expensive Bayes factor method, and the Kolmogorov-Smirnov and runs tests proved to be the relatively ineffective in reliably detecting a change point. We then apply the methods tested to events at different thresholds above magnitude M ≥ 7 in the global earthquake catalogue since 1918, after first declustering the catalogue. This is most effectively done by removing likely correlated events using a much lower magnitude threshold (M ≥ 5), where triggering is much more obvious. We find no strong evidence that the background rate of large events worldwide has increased in recent years.

Large-Scale Test of Dynamic Correlation Processors: Implications for Correlation-Based Seismic Pipelines

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

Dodge, D. A.; Harris, D. B.

Correlation detectors are of considerable interest to the seismic monitoring communities because they offer reduced detection thresholds and combine detection, location and identification functions into a single operation. They appear to be ideal for applications requiring screening of frequent repeating events. However, questions remain about how broadly empirical correlation methods are applicable. We describe the effectiveness of banks of correlation detectors in a system that combines traditional power detectors with correlation detectors in terms of efficiency, which we define to be the fraction of events detected by the correlators. This paper elaborates and extends the concept of a dynamic correlationmore » detection framework – a system which autonomously creates correlation detectors from event waveforms detected by power detectors; and reports observed performance on a network of arrays in terms of efficiency. We performed a large scale test of dynamic correlation processors on an 11 terabyte global dataset using 25 arrays in the single frequency band 1-3 Hz. The system found over 3.2 million unique signals and produced 459,747 screened detections. A very satisfying result is that, on average, efficiency grows with time and, after nearly 16 years of operation, exceeds 47% for events observed over all distance ranges and approaches 70% for near regional and 90% for local events. This observation suggests that future pipeline architectures should make extensive use of correlation detectors, principally for decluttering observations of local and near-regional events. Our results also suggest that future operations based on correlation detection will require commodity large-scale computing infrastructure, since the numbers of correlators in an autonomous system can grow into the hundreds of thousands.« less

Large-Scale Test of Dynamic Correlation Processors: Implications for Correlation-Based Seismic Pipelines

DOE PAGES

Dodge, D. A.; Harris, D. B.

2016-03-15

Correlation detectors are of considerable interest to the seismic monitoring communities because they offer reduced detection thresholds and combine detection, location and identification functions into a single operation. They appear to be ideal for applications requiring screening of frequent repeating events. However, questions remain about how broadly empirical correlation methods are applicable. We describe the effectiveness of banks of correlation detectors in a system that combines traditional power detectors with correlation detectors in terms of efficiency, which we define to be the fraction of events detected by the correlators. This paper elaborates and extends the concept of a dynamic correlationmore » detection framework – a system which autonomously creates correlation detectors from event waveforms detected by power detectors; and reports observed performance on a network of arrays in terms of efficiency. We performed a large scale test of dynamic correlation processors on an 11 terabyte global dataset using 25 arrays in the single frequency band 1-3 Hz. The system found over 3.2 million unique signals and produced 459,747 screened detections. A very satisfying result is that, on average, efficiency grows with time and, after nearly 16 years of operation, exceeds 47% for events observed over all distance ranges and approaches 70% for near regional and 90% for local events. This observation suggests that future pipeline architectures should make extensive use of correlation detectors, principally for decluttering observations of local and near-regional events. Our results also suggest that future operations based on correlation detection will require commodity large-scale computing infrastructure, since the numbers of correlators in an autonomous system can grow into the hundreds of thousands.« less

Association of single nucleotide polymorphisms in a glutamate receptor gene (GRM8) with theta power of event-related oscillations and alcohol dependence.

PubMed

Chen, Andrew C H; Tang, Yongqiang; Rangaswamy, Madhavi; Wang, Jen C; Almasy, Laura; Foroud, Tatiana; Edenberg, Howard J; Hesselbrock, Victor; Nurnberger, John; Kuperman, Samuel; O'Connor, Sean J; Schuckit, Marc A; Bauer, Lance O; Tischfield, Jay; Rice, John P; Bierut, Laura; Goate, Alison; Porjesz, Bernice

2009-04-05

Evidence suggests the P3 amplitude of the event-related potential and its underlying superimposed event-related oscillations (EROs), primarily in the theta (4-5 Hz) and delta (1-3 Hz) frequencies, as endophenotypes for the risk of alcoholism and other disinhibitory disorders. Major neurochemical substrates contributing to theta and delta rhythms and P3 involve strong GABAergic, cholinergic and glutamatergic system interactions. The aim of this study was to test the potential associations between single nucleotide polymorphisms (SNPs) in glutamate receptor genes and ERO quantitative traits. GRM8 was selected because it maps at chromosome 7q31.3-q32.1 under the peak region where we previously identified significant linkage (peak LOD = 3.5) using a genome-wide linkage scan of the same phenotype (event-related theta band for the target visual stimuli). Neural activities recorded from scalp electrodes during a visual oddball task in which rare target elicited P3s were analyzed in a subset of the Collaborative Study on the Genetics of Alcoholism (COGA) sample comprising 1,049 Caucasian subjects from 209 families (with 472 DSM-IV alcohol dependent individuals). The family-based association test (FBAT) detected significant association (P < 0.05) with multiple SNPs in the GRM8 gene and event-related theta power to target visual stimuli, and also with alcohol dependence, even after correction for multiple comparisons by false discovery rate (FDR). Our results suggest that variation in GRM8 may be involved in modulating event-related theta oscillations during information processing and also in vulnerability to alcoholism. These findings underscore the utility of electrophysiology and the endophenotype approach in the genetic study of psychiatric disorders. (c) 2008 Wiley-Liss, Inc.

The effect of a career activity on the students' perception of the nursing profession and their career plan: A single-group experimental study.

PubMed

Yilmaz, Arzu Akman; Ilce, Arzu; Can Cicek, Saadet; Yuzden, Ganime Esra; Yigit, Ummuhan

2016-04-01

Students' conceptualizations of nursing and their reasons for choosing the profession motivate them and affect their education, work performance and career plans. Nursing educators should support them to plan their careers consciously during their education. The study aimed to investigate the effect of career-planning event for nursing students on their conceptualizations of the nursing profession and their career plans. The study was as single-group experimental study using a pre-test and post-test. The career-planning event was held in the conference hall of the university involved in the current study, and was open to the all students of the nursing school. The sample of the study consisted of 105 students who participated in the "Nursing Career Symposium" held on 27 March 2015. Methods At the event, the importance of career planning and the opportunities of the nursing profession was presented. The data were collected using a questionnaire consisted of two sections including descriptive characteristics and the opinions of the students regarding their career plans and Perception of Nursing Profession Scale. The students completed the first section of the questionnaire before the career event began and the second section of the questionnaire and scale both before and after the event. The participants had positive conceptualizations of the profession. Following a career event, the participants' opinions of professional qualities and professional status as measured through the Perception of Nursing Profession Scale showed a significant increase, and that the event had made an important contribution to their career plans. In the light of these results, it is possible to suggest that such events have an important place during education in that they introduce the nursing profession, and they develop the students' positive thoughts regarding the profession in terms of both course content and teaching methodology. Copyright © 2016 Elsevier Ltd. All rights reserved.

Trending autoregulatory indices during treatment for traumatic brain injury.

PubMed

Kim, Nam; Krasner, Alex; Kosinski, Colin; Wininger, Michael; Qadri, Maria; Kappus, Zachary; Danish, Shabbar; Craelius, William

2016-12-01

Our goal is to use automatic data monitoring for reliable prediction of episodes of intracranial hypertension in patients with traumatic brain injury. Here we test the validity of our method on retrospective patient data. We developed the Continuous Hemodynamic Autoregulatory Monitor (CHARM), that siphons and stores signals from existing monitors in the surgical intensive care unit (SICU), efficiently compresses them, and standardizes the search for statistical relationships between any proposed index and adverse events. CHARM uses an automated event detector to reliably locate episodes of elevated intracranial pressure (ICP), while eliminating artifacts within retrospective patient data. A graphical user interface allowed data scanning, selection of criteria for events, and calculating indices. The pressure reactivity index (PRx), defined as the least square linear regression slope of intracranial pressure versus arterial BP, was calculated for a single case that spanned 259 h. CHARM collected continuous records of ABP, ICP, ECG, SpO2, and ventilation from 29 patients with TBI over an 18-month period. Analysis of a single patient showed that PRx data distribution in the single hours immediately prior to all 16 intracranial hypertensive events, significantly differed from that in the 243 h that did not precede such events (p < 0.0001). The PRx index, however, lacked sufficient resolution as a real-time predictor of IH in this patient. CHARM streamlines the search for reliable predictors of intracranial hypertension. We report statistical evidence supporting the predictive potential of the pressure reactivity index.

Behavioral and neuroanatomical investigation of Highly Superior Autobiographical Memory (HSAM)

PubMed Central

LePort, Aurora K.R.; Mattfeld, Aaron T.; Dickinson-Anson, Heather; Fallon, James H.; Stark, Craig E.L.; Kruggel, Frithjof; Cahill, Larry; McGaugh, James L.

2013-01-01

A single case study recently documented one woman’s ability to recall accurately vast amounts of autobiographical information, spanning most of her lifetime, without the use of practiced mnemonics (Parker, Cahill, & McGaugh, 2006). The current study reports findings based on eleven participants expressing this same memory ability, now referred to as Highly Superior Autobiographical Memory (HSAM). Participants were identified and subsequently characterized based on screening for memory of public events. They were then tested for personal autobiographical memories as well as for memory assessed by laboratory memory tests. Additionally, whole-brain structural MRI scans were obtained. Results indicated that HSAM participants performed significantly better at recalling public as well as personal autobiographical events as well as the days and dates on which these events occurred. However, their performance was comparable to age- and sex-matched controls on most standard laboratory memory tests. Neuroanatomical results identified nine structures as being morphologically different from those of control participants. The study of HSAM may provide new insights into the neurobiology of autobiographical memory. PMID:22652113

An integrated logit model for contamination event detection in water distribution systems.

PubMed

Housh, Mashor; Ostfeld, Avi

2015-05-15

The problem of contamination event detection in water distribution systems has become one of the most challenging research topics in water distribution systems analysis. Current attempts for event detection utilize a variety of approaches including statistical, heuristics, machine learning, and optimization methods. Several existing event detection systems share a common feature in which alarms are obtained separately for each of the water quality indicators. Unifying those single alarms from different indicators is usually performed by means of simple heuristics. A salient feature of the current developed approach is using a statistically oriented model for discrete choice prediction which is estimated using the maximum likelihood method for integrating the single alarms. The discrete choice model is jointly calibrated with other components of the event detection system framework in a training data set using genetic algorithms. The fusing process of each indicator probabilities, which is left out of focus in many existing event detection system models, is confirmed to be a crucial part of the system which could be modelled by exploiting a discrete choice model for improving its performance. The developed methodology is tested on real water quality data, showing improved performances in decreasing the number of false positive alarms and in its ability to detect events with higher probabilities, compared to previous studies. Copyright © 2015 Elsevier Ltd. All rights reserved.

ULTRAFINE PARTICULATE MATTER EXPOSURE ATTENUATES MOUSE AORTIC RELAXATIONS

EPA Science Inventory

Particulate air pollution (PM) contributes to adverse cardiovascular events by yet unknown mechanisms. We tested the hypothesis that PM exposure altered endothelial regulation of systemic vascular tone. 6-10 week old male ICR mice were exposed to a single dose of 10, 30 or 100 'g...

Evaluation of an Ultra-Low Power Reed Solomon Encoder for NASA's Space Technology 5 Mission

NASA Technical Reports Server (NTRS)

Li, K. E.; Xapsos, M. A.; Poivey, C.; LaBel, K. A.; Stone, R. F.; Yeh, P-S.; Gambles, J.; Hass, J.; Maki, G.; Marguia, J.

2003-01-01

This viewgraph presentation provides information on radiation tests on encoders intended for a constellation of microsatellites. The encoders use CMOS Ultra-Low Power Radiation Tolerant (CULPRiT) technology. The presentation addresses power consumption, radiation dosage, and Single Event Upset (SEU).

Extracellular adenosine initiates rapid arteriolar vasodilation induced by a single skeletal muscle contraction in hamster cremaster muscle.

PubMed

Ross, G A; Mihok, M L; Murrant, C L

2013-05-01

Recent studies suggest that adenosine (ADO) can be produced extracellularly in response to skeletal muscle contraction. We tested the hypothesis that a single muscle contraction produces extracellular ADO rapidly enough and in physiologically relevant concentrations to be able to contribute to the rapid vasodilation that occurs at the onset of muscle contraction. We stimulated four to five skeletal muscle fibres in the anaesthetized hamster cremaster preparation in situ and measured the change in diameter of arterioles at a site of overlap with the stimulated muscle fibres before and after a single contraction (stimulus frequencies: 4, 20 and 60 Hz; 250 ms train duration). Muscle fibres were stimulated in the absence and presence of non-specific ADO membrane receptor antagonists 8-phenyltheophylline (8-PT, 10(-6) M) or xanthine amine congener (XAC, 10(-6) M) or an inhibitor of an extracellular source of ADO, ecto-5'-nucleotidase inhibitor α,β-methylene adenosine 5'-diphosphate (AMPCP, 10(-5) M). We observed that the dilatory event at 4 s following a single contraction was significantly inhibited at all stimulus frequencies by an average of 63.9 ± 2.6% by 8-PT. The 20-s dilatory event that occurred at 20 and 60 Hz was significantly inhibited by 53.6 ± 2.6 and 73.8 ± 2.3% by 8-PT and XAC respectively. Further, both the 4- and 20-s dilatory events were significantly inhibited by AMPCP by 78.6 ± 6.6 and 67.1 ± 1.5%, respectively, at each stimulus frequency tested. Our data show that ADO is produced extracellularly during a single muscle contraction and that it is produced rapidly enough and in physiologically relevant concentrations to contribute to the rapid vasodilation in response to muscle contraction. © 2013 The Authors Acta Physiologica © 2013 Scandinavian Physiological Society.

Complex Dynamic Scene Perception: Effects of Attentional Set on Perceiving Single and Multiple Event Types

ERIC Educational Resources Information Center

Sanocki, Thomas; Sulman, Noah

2013-01-01

Three experiments measured the efficiency of monitoring complex scenes composed of changing objects, or events. All events lasted about 4 s, but in a given block of trials, could be of a single type (single task) or of multiple types (multitask, with a total of four event types). Overall accuracy of detecting target events amid distractors was…

Optimized breeding strategies for multiple trait integration: II. Process efficiency in event pyramiding and trait fixation.

PubMed

Peng, Ting; Sun, Xiaochun; Mumm, Rita H

2014-01-01

Multiple trait integration (MTI) is a multi-step process of converting an elite variety/hybrid for value-added traits (e.g. transgenic events) through backcross breeding. From a breeding standpoint, MTI involves four steps: single event introgression, event pyramiding, trait fixation, and version testing. This study explores the feasibility of marker-aided backcross conversion of a target maize hybrid for 15 transgenic events in the light of the overall goal of MTI of recovering equivalent performance in the finished hybrid conversion along with reliable expression of the value-added traits. Using the results to optimize single event introgression (Peng et al. Optimized breeding strategies for multiple trait integration: I. Minimizing linkage drag in single event introgression. Mol Breed, 2013) which produced single event conversions of recurrent parents (RPs) with ≤8 cM of residual non-recurrent parent (NRP) germplasm with ~1 cM of NRP germplasm in the 20 cM regions flanking the event, this study focused on optimizing process efficiency in the second and third steps in MTI: event pyramiding and trait fixation. Using computer simulation and probability theory, we aimed to (1) fit an optimal breeding strategy for pyramiding of eight events into the female RP and seven in the male RP, and (2) identify optimal breeding strategies for trait fixation to create a 'finished' conversion of each RP homozygous for all events. In addition, next-generation seed needs were taken into account for a practical approach to process efficiency. Building on work by Ishii and Yonezawa (Optimization of the marker-based procedures for pyramiding genes from multiple donor lines: I. Schedule of crossing between the donor lines. Crop Sci 47:537-546, 2007a), a symmetric crossing schedule for event pyramiding was devised for stacking eight (seven) events in a given RP. Options for trait fixation breeding strategies considered selfing and doubled haploid approaches to achieve homozygosity as well as seed chipping and tissue sampling approaches to facilitate genotyping. With selfing approaches, two generations of selfing rather than one for trait fixation (i.e. 'F2 enrichment' as per Bonnett et al. in Strategies for efficient implementation of molecular markers in wheat breeding. Mol Breed 15:75-85, 2005) were utilized to eliminate bottlenecking due to extremely low frequencies of desired genotypes in the population. The efficiency indicators such as total number of plants grown across generations, total number of marker data points, total number of generations, number of seeds sampled by seed chipping, number of plants requiring tissue sampling, and number of pollinations (i.e. selfing and crossing) were considered in comparisons of breeding strategies. A breeding strategy involving seed chipping and a two-generation selfing approach (SC + SELF) was determined to be the most efficient breeding strategy in terms of time to market and resource requirements. Doubled haploidy may have limited utility in trait fixation for MTI under the defined breeding scenario. This outcome paves the way for optimizing the last step in the MTI process, version testing, which involves hybridization of female and male RP conversions to create versions of the converted hybrid for performance evaluation and possible commercial release.

Calibration and Extension of a Discrete Event Operations Simulation Modeling Multiple Un-Manned Aerial Vehicles Controlled by a Single Operator

DTIC Science & Technology

2013-03-01

within systems of UAVs and between UAVs and the operators that use them. The next step for small UAVs in this direction is for one operator to be able...Team’s testing efforts, both in the planning and execution stages. The flight tests would never have taken place without the tremendous assistance...1 1.2 Unmanned Aerial Systems

Comparison of Single-Event Transients Induced in an Operational Amplifier (LM124) by Pulsed Laser Light and a Broad Beam of Heavy Ions

NASA Technical Reports Server (NTRS)

Buchner, Steve; McMorrow, Dale; Poivey, Christian; Howard, James, Jr.; Pease, Rom; Savage, Mark; Boulghassoul, Younis; Massengill, Lloyd

2003-01-01

A comparison of transients from heavy-ion and pulsed-laser testing shows good agreement for many different voltage configurations. The agreement is illustrated by comparing directly individual transients and plots of transient amplitude versus width.

neutron-Induced Failures in semiconductor Devices

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

Wender, Stephen Arthur

2017-03-13

Single Event Effects are a very significant failure mode in modern semiconductor devices that may limit their reliability. Accelerated testing is important for semiconductor industry. Considerable more work is needed in this field to mitigate the problem. Mitigation of this problem will probably come from Physicists and Electrical Engineers working together

Overview of Device SEE Susceptibility from Heavy Ions

NASA Technical Reports Server (NTRS)

Nichols, D. K.; Coss, J. R.; McCarthy, K. P.; Schwartz, H. R.; Smith, L. S.

1998-01-01

A fifth set of heavy ion single event effects (SEE) test data have been collected since the last IEEE publications (1,2,3,4) in December issues for 1985, 1987, 1989, and 1991. Trends in SEE susceptibility (including soft errors and latchup) for state-of-the-art parts are evaluated.

Developmental outcome after a single episode of status epilepticus.

PubMed

Roy, Hélène; Lippé, Sarah; Lussier, Francine; Sauerwein, Hannelore Catherine; Lortie, Anne; Lacroix, Jacques; Lassonde, Maryse

2011-08-01

Consequences of status epilepticus (SE) on psychomotor development and the specific impact of the convulsive event on emerging executive functions remain controversial. Infants treated for a single episode of SE, those treated for a single febrile seizure, and healthy infants were tested with respect to motor development, language, personal, and social skills and self-regulation. The children were divided into two age groups to investigate the impact of the convulsive event at different windows of brain maturation. We found that infants who had had SE were inferior to healthy controls on the development scales. Age differentiated SE impact on visuomotor development versus sociolinguistic development. Children who had been treated for SE had significantly more difficulties delaying a response to an attractive stimulus in one of the long-delay conditions. A single episode of SE can interfere with psychomotor and cognitive development in children without previous developmental delay, and it seems that the functions that are emerging at the time of insult are most vulnerable. Crown Copyright © 2011. Published by Elsevier Inc. All rights reserved.

Board Level Proton Testing Book of Knowledge for NASA Electronic Parts and Packaging Program

NASA Technical Reports Server (NTRS)

Guertin, Steven M.

2017-01-01

This book of knowledge (BoK) provides a critical review of the benefits and difficulties associated with using proton irradiation as a means of exploring the radiation hardness of commercial-off-the-shelf (COTS) systems. This work was developed for the NASA Electronic Parts and Packaging (NEPP) Board Level Testing for the COTS task. The fundamental findings of this BoK are the following. The board-level test method can reduce the worst case estimate for a board's single-event effect (SEE) sensitivity compared to the case of no test data, but only by a factor of ten. The estimated worst case rate of failure for untested boards is about 0.1 SEE/board-day. By employing the use of protons with energies near or above 200 MeV, this rate can be safely reduced to 0.01 SEE/board-day, with only those SEEs with deep charge collection mechanisms rising this high. For general SEEs, such as static random-access memory (SRAM) upsets, single-event transients (SETs), single-event gate ruptures (SEGRs), and similar cases where the relevant charge collection depth is less than 10 µm, the worst case rate for SEE is below 0.001 SEE/board-day. Note that these bounds assume that no SEEs are observed during testing. When SEEs are observed during testing, the board-level test method can establish a reliable event rate in some orbits, though all established rates will be at or above 0.001 SEE/board-day. The board-level test approach we explore has picked up support as a radiation hardness assurance technique over the last twenty years. The approach originally was used to provide a very limited verification of the suitability of low cost assemblies to be used in the very benign environment of the International Space Station (ISS), in limited reliability applications. Recently the method has been gaining popularity as a way to establish a minimum level of SEE performance of systems that require somewhat higher reliability performance than previous applications. This sort of application of the method suggests a critical analysis of the method is in order. This is also of current consideration because the primary facility used for this type of work, the Indiana University Cyclotron Facility (IUCF) (also known as the Integrated Science and Technology (ISAT) hall), has closed permanently, and the future selection of alternate test facilities is critically important. This document reviews the main theoretical work on proton testing of assemblies over the last twenty years. It augments this with review of reported data generated from the method and other data that applies to the limitations of the proton board-level test approach. When protons are incident on a system for test they can produce spallation reactions. From these reactions, secondary particles with linear energy transfers (LETs) significantly higher than the incident protons can be produced. These secondary particles, together with the protons, can simulate a subset of the space environment for particles capable of inducing single event effects (SEEs). The proton board-level test approach has been used to bound SEE rates, establishing a maximum possible SEE rate that a test article may exhibit in space. This bound is not particularly useful in many cases because the bound is quite loose. We discuss the established limit that the proton board-level test approach leaves us with. The remaining possible SEE rates may be as high as one per ten years for most devices. The situation is actually more problematic for many SEE types with deep charge collection. In cases with these SEEs, the limits set by the proton board-level test can be on the order of one per 100 days. Because of the limited nature of the bounds established by proton testing alone, it is possible that tested devices will have actual SEE sensitivity that is very low (e.g., fewer than one event in 1 × 10(exp 4) years), but the test method will only be able to establish the limits indicated above. This BoK further examines other benefits of proton board-level testing besides hardness assurance. The primary alternate use is the injection of errors. Error injection, or fault injection, is something that is often done in a simulation environment. But the proton beam has the benefit of injecting the majority of actual SEEs without risk of something being missed, and without the risk of simulation artifacts misleading the SEE investigation.

Charge generation by heavy ions in power MOSFETs, burnout space predictions, and dynamic SEB sensitivity

NASA Technical Reports Server (NTRS)

Stassinopoulos, E. G.; Brucker, G. J.; Calvel, P.; Baiget, A.; Peyrotte, C.; Gaillard, R.

1992-01-01

The transport, energy loss, and charge production of heavy ions in the sensitive regions of IRF 150 power MOSFETs are described. The dependence and variation of transport parameters with ion type and energy relative to the requirements for single event burnout in this part type are discussed. Test data taken with this power MOSFET are used together with analyses by means of a computer code of the ion energy loss and charge production in the device to establish criteria for burnout and parameters for space predictions. These parameters are then used in an application to predict burnout rates in a geostationary orbit for power converters operating in a dynamic mode. Comparisons of rates for different geometries in simulating SEU (single event upset) sensitive volumes are presented.

PDSOI and Radiation Effects: An Overview

NASA Technical Reports Server (NTRS)

Forgione, Joshua B.

2005-01-01

Bulk silicon substrates are a common characteristic of nearly all commercial, Complementary Metal-Oxide-Semiconductor (CMOS), integrated circuits. These devices operate well on Earth, but are not so well received in the space environment. An alternative to bulk CMOS is the Silicon-On-Insulator (SOI), in which a &electric isolates the device layer from the substrate. SO1 behavior in the space environment has certain inherent advantages over bulk, a primary factor in its long-time appeal to space-flight IC designers. The discussion will investigate the behavior of the Partially-Depleted SO1 (PDSOI) device with respect to some of the more common space radiation effects: Total Ionized Dose (TID), Single-Event Upsets (SEUs), and Single-Event Latchup (SEL). Test and simulation results from the literature, bulk and epitaxial comparisons facilitate reinforcement of PDSOI radiation characteristics.

Dead-time optimized time-correlated photon counting instrument with synchronized, independent timing channels

NASA Astrophysics Data System (ADS)

Wahl, Michael; Rahn, Hans-Jürgen; Gregor, Ingo; Erdmann, Rainer; Enderlein, Jörg

2007-03-01

Time-correlated single photon counting is a powerful method for sensitive time-resolved fluorescence measurements down to the single molecule level. The method is based on the precisely timed registration of single photons of a fluorescence signal. Historically, its primary goal was the determination of fluorescence lifetimes upon optical excitation by a short light pulse. This goal is still important today and therefore has a strong influence on instrument design. However, modifications and extensions of the early designs allow for the recovery of much more information from the detected photons and enable entirely new applications. Here, we present a new instrument that captures single photon events on multiple synchronized channels with picosecond resolution and over virtually unlimited time spans. This is achieved by means of crystal-locked time digitizers with high resolution and very short dead time. Subsequent event processing in programmable logic permits classical histogramming as well as time tagging of individual photons and their streaming to the host computer. Through the latter, any algorithms and methods for the analysis of fluorescence dynamics can be implemented either in real time or offline. Instrument test results from single molecule applications will be presented.

A single CD4 test with 250 cells/mm3 threshold predicts viral suppression in HIV-infected adults failing first-line therapy by clinical criteria.

PubMed

Gilks, Charles F; Walker, A Sarah; Munderi, Paula; Kityo, Cissy; Reid, Andrew; Katabira, Elly; Goodall, Ruth L; Grosskurth, Heiner; Mugyenyi, Peter; Hakim, James; Gibb, Diana M

2013-01-01

In low-income countries, viral load (VL) monitoring of antiretroviral therapy (ART) is rarely available in the public sector for HIV-infected adults or children. Using clinical failure alone to identify first-line ART failure and trigger regimen switch may result in unnecessary use of costly second-line therapy. Our objective was to identify CD4 threshold values to confirm clinically-determined ART failure when VL is unavailable. 3316 HIV-infected Ugandan/Zimbabwean adults were randomised to first-line ART with Clinically-Driven (CDM, CD4s measured but blinded) or routine Laboratory and Clinical Monitoring (LCM, 12-weekly CD4s) in the DART trial. CD4 at switch and ART failure criteria (new/recurrent WHO 4, single/multiple WHO 3 event; LCM: CD4<100 cells/mm(3)) were reviewed in 361 LCM, 314 CDM participants who switched over median 5 years follow-up. Retrospective VLs were available in 368 (55%) participants. Overall, 265/361 (73%) LCM participants failed with CD4<100 cells/mm(3); only 7 (2%) switched with CD4≥250 cells/mm(3), four switches triggered by WHO events. Without CD4 monitoring, 207/314 (66%) CDM participants failed with WHO 4 events, and 77(25%)/30(10%) with single/multiple WHO 3 events. Failure/switching with single WHO 3 events was more likely with CD4≥250 cells/mm(3) (28/77; 36%) (p = 0.0002). CD4 monitoring reduced switching with viral suppression: 23/187 (12%) LCM versus 49/181 (27%) CDM had VL<400 copies/ml at failure/switch (p<0.0001). Amongst CDM participants with CD4<250 cells/mm(3) only 11/133 (8%) had VL<400 copies/ml, compared with 38/48 (79%) with CD4≥250 cells/mm(3) (p<0.0001). Multiple, but not single, WHO 3 events predicted first-line ART failure. A CD4 threshold 'tiebreaker' of ≥250 cells/mm(3) for clinically-monitored patients failing first-line could identify ∼80% with VL<400 copies/ml, who are unlikely to benefit from second-line. Targeting CD4s to single WHO stage 3 'clinical failures' would particularly avoid premature, costly switch to second-line ART.

A Single CD4 Test with 250 Cells/Mm3 Threshold Predicts Viral Suppression in HIV-Infected Adults Failing First-Line Therapy by Clinical Criteria

PubMed Central

Munderi, Paula; Kityo, Cissy; Reid, Andrew; Katabira, Elly; Goodall, Ruth L.; Grosskurth, Heiner; Mugyenyi, Peter; Hakim, James; Gibb, Diana M.

2013-01-01

Background In low-income countries, viral load (VL) monitoring of antiretroviral therapy (ART) is rarely available in the public sector for HIV-infected adults or children. Using clinical failure alone to identify first-line ART failure and trigger regimen switch may result in unnecessary use of costly second-line therapy. Our objective was to identify CD4 threshold values to confirm clinically-determined ART failure when VL is unavailable. Methods 3316 HIV-infected Ugandan/Zimbabwean adults were randomised to first-line ART with Clinically-Driven (CDM, CD4s measured but blinded) or routine Laboratory and Clinical Monitoring (LCM, 12-weekly CD4s) in the DART trial. CD4 at switch and ART failure criteria (new/recurrent WHO 4, single/multiple WHO 3 event; LCM: CD4<100 cells/mm3) were reviewed in 361 LCM, 314 CDM participants who switched over median 5 years follow-up. Retrospective VLs were available in 368 (55%) participants. Results Overall, 265/361 (73%) LCM participants failed with CD4<100 cells/mm3; only 7 (2%) switched with CD4≥250 cells/mm3, four switches triggered by WHO events. Without CD4 monitoring, 207/314 (66%) CDM participants failed with WHO 4 events, and 77(25%)/30(10%) with single/multiple WHO 3 events. Failure/switching with single WHO 3 events was more likely with CD4≥250 cells/mm3 (28/77; 36%) (p = 0.0002). CD4 monitoring reduced switching with viral suppression: 23/187 (12%) LCM versus 49/181 (27%) CDM had VL<400 copies/ml at failure/switch (p<0.0001). Amongst CDM participants with CD4<250 cells/mm3 only 11/133 (8%) had VL<400copies/ml, compared with 38/48 (79%) with CD4≥250 cells/mm3 (p<0.0001). Conclusion Multiple, but not single, WHO 3 events predicted first-line ART failure. A CD4 threshold ‘tiebreaker’ of ≥250 cells/mm3 for clinically-monitored patients failing first-line could identify ∼80% with VL<400 copies/ml, who are unlikely to benefit from second-line. Targeting CD4s to single WHO stage 3 ‘clinical failures’ would particularly avoid premature, costly switch to second-line ART. PMID:23437399

[Posttraumatic anosmia: olfactory event related potentials and MRI evaluation].

PubMed

Liu, Jian-Feng; You, Hui; Ni, Dao-Feng; Zhang, Qiu-Hang; Yang, Da-Zhang; Wang, Na-Ya

2008-03-01

Using olfactory event related potentials (OERP) and magnetic resonance to evaluate olfactory function in patients with posttraumatic anosmia. Twenty four patients with posttraumatic anosmia were reviewed retrospectively. A thorough medical history, physical examination, nasal endoscopy, T&T olfactory testing, olfactory event-related potentials, brain computed tomography scan and magnetic resonance image of olfactory pathway were performed in all patients. Subjective olfactory testing indicated 20 of 24 patients were birhinal anosmia, 2 with right nostril anosmia and left impairment, 2 with left anosmia and right normal. No OERP were obtained in 24 (20 were birhinal, 4 was monorhinal), except 4 cases with single nostril. Magnetic resonance imaging revealed the injures to the olfactory bulbs (100%), rectus gyrus (91.7%), orbital gyrus (67%), olfactory tracts (8%) and temporal lobes (8%). OERP can objectively evaluate posttraumatic olfactory function, and magnetic resonance of olfactory pathway can precisely identify the location and extent of injures.

Analytical Framework for Identifying and Differentiating Recent Hitchhiking and Severe Bottleneck Effects from Multi-Locus DNA Sequence Data

DOE PAGES

Sargsyan, Ori

2012-05-25

Hitchhiking and severe bottleneck effects have impact on the dynamics of genetic diversity of a population by inducing homogenization at a single locus and at the genome-wide scale, respectively. As a result, identification and differentiation of the signatures of such events from DNA sequence data at a single locus is challenging. This study develops an analytical framework for identifying and differentiating recent homogenization events at multiple neutral loci in low recombination regions. The dynamics of genetic diversity at a locus after a recent homogenization event is modeled according to the infinite-sites mutation model and the Wright-Fisher model of reproduction withmore » constant population size. In this setting, I derive analytical expressions for the distribution, mean, and variance of the number of polymorphic sites in a random sample of DNA sequences from a locus affected by a recent homogenization event. Based on this framework, three likelihood-ratio based tests are presented for identifying and differentiating recent homogenization events at multiple loci. Lastly, I apply the framework to two data sets. First, I consider human DNA sequences from four non-coding loci on different chromosomes for inferring evolutionary history of modern human populations. The results suggest, in particular, that recent homogenization events at the loci are identifiable when the effective human population size is 50000 or greater in contrast to 10000, and the estimates of the recent homogenization events are agree with the “Out of Africa” hypothesis. Second, I use HIV DNA sequences from HIV-1-infected patients to infer the times of HIV seroconversions. The estimates are contrasted with other estimates derived as the mid-time point between the last HIV-negative and first HIV-positive screening tests. Finally, the results show that significant discrepancies can exist between the estimates.« less

Investigation of HZETRN 2010 as a Tool for Single Event Effect Qualification of Avionics Systems

NASA Technical Reports Server (NTRS)

Rojdev, Kristina; Koontz, Steve; Atwell, William; Boeder, Paul

2014-01-01

NASA's future missions are focused on long-duration deep space missions for human exploration which offers no options for a quick emergency return to Earth. The combination of long mission duration with no quick emergency return option leads to unprecedented spacecraft system safety and reliability requirements. It is important that spacecraft avionics systems for human deep space missions are not susceptible to Single Event Effect (SEE) failures caused by space radiation (primarily the continuous galactic cosmic ray background and the occasional solar particle event) interactions with electronic components and systems. SEE effects are typically managed during the design, development, and test (DD&T) phase of spacecraft development by using heritage hardware (if possible) and through extensive component level testing, followed by system level failure analysis tasks that are both time consuming and costly. The ultimate product of the SEE DD&T program is a prediction of spacecraft avionics reliability in the flight environment produced using various nuclear reaction and transport codes in combination with the component and subsystem level radiation test data. Previous work by Koontz, et al.1 utilized FLUKA, a Monte Carlo nuclear reaction and transport code, to calculate SEE and single event upset (SEU) rates. This code was then validated against in-flight data for a variety of spacecraft and space flight environments. However, FLUKA has a long run-time (on the order of days). CREME962, an easy to use deterministic code offering short run times, was also compared with FLUKA predictions and in-flight data. CREME96, though fast and easy to use, has not been updated in several years and underestimates secondary particle shower effects in spacecraft structural shielding mass. Thus, this paper will investigate the use of HZETRN 20103, a fast and easy to use deterministic transport code, similar to CREME96, that was developed at NASA Langley Research Center primarily for flight crew ionizing radiation dose assessments. HZETRN 2010 includes updates to address secondary particle shower effects more accurately, and might be used as another tool to verify spacecraft avionics system reliability in space flight SEE environments.

Frequency Dependence of Single-event Upset in Advanced Commerical PowerPC Microprocessors

NASA Technical Reports Server (NTRS)

Irom, Frokh; Farmanesh, Farhad F.; Swift, Gary M.; Johnston, Allen H.

2004-01-01

This paper examines single-event upsets in advanced commercial SOI microprocessors in a dynamic mode, studying SEU sensitivity of General Purpose Registers (GPRs) with clock frequency. Results are presented for SOI processors with feature sizes of 0.18 microns and two different core voltages. Single-event upset from heavy ions is measured for advanced commercial microprocessors in a dynamic mode with clock frequency up to 1GHz. Frequency and core voltage dependence of single-event upsets in registers is discussed.

Real Time Fault Detection and Diagnostics Using FPGA-Based Architectures

DTIC Science & Technology

2010-03-01

vector sets sent to the DUT. The testing platform combines a myriad of testing and measuring equipment and work hours onto one small reprogrammable ...recently few reprogrammable devices have been used on spacecraft due to their sensitivity to involuntary reconfiguration due to Single Event Upsets...Determination of Nuclear Yield from Thermal Degradation of Automobile Paint MS Thesis. AFIT/GWM/ENP/10-M10. Wright-Patterson AFB OH: Graduate School of

[Follow-up of patients with good exercise capacity in stress test with myocardial single-photon emission computed tomography (SPECT)].

PubMed

González, Javiera; Prat, Hernán; Swett, Eduardo; Berrocal, Isabel; Fernández, René; Zhindon, Juan Pablo; Castro, Ariel; Massardo, Teresa

2015-11-01

The evaluation of coronary artery disease (CAD) can be performed with stress test and myocardial SPECT tomography. To assess the predictive value of myocardial SPECT using stress test for cardiovascular events in patients with good exercise capacity. We included 102 males aged 56 ± 10 years and 19 females aged 52 ± 10 years, all able to achieve 10 METs and ≥ 85% of the theoretical maximum heart rate and at least 8 min in their stress test with gated 99mTc-sestamibi SPECT. Eighty two percent of patients were followed clinically for 33 ± 17 months. Sixty seven percent of patients were studied for CAD screening and the rest for known disease assessment. Treadmill stress test was negative in 75.4%; 37% of patients with moderate to severe Duke Score presented ischemia. Normal myocardial perfusion SPECT was observed in 70.2%. Reversible defects appeared in 24.8% of cases, which were of moderate or severe degree (> 10% left ventricular extension) in 56.6%. Only seven cases had coronary events after the SPECT. Two major (myocardial infarction and emergency coronary revascularization) and 5 minor events (elective revascularization) ere observed in the follow-up. In a multivariate analysis, SPECT ischemia was the only statistically significant parameter that increased the probability of having a major or minor event. Nearly a quarter of our patients with good exercise capacity demonstrated reversible defects in their myocardial perfusion SPECT. In the intermediate-term follow-up, a low rate of cardiac events was observed, being the isotopic ischemia the only significant predictive parameter.

Contemporary Toxicity Profile of Breast Brachytherapy Versus External Beam Radiation After Lumpectomy for Breast Cancer

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

Huo, Jinhai; Giordano, Sharon H.; Department of Breast Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas

Purpose: We compared toxicities after brachytherapy versus external beam radiation therapy (EBRT) in contemporary breast cancer patients. Methods and Materials: Using MarketScan healthcare claims, we identified 64,112 women treated from 2003 to 2012 with lumpectomy followed by radiation (brachytherapy vs EBRT). Brachytherapy was further classified by multichannel versus single-channel applicator approach. We identified the risks and predictors of 1-year infectious and noninfectious postoperative adverse events using logistic regression and temporal trends using Cochran-Armitage tests. We estimated the 5-year Kaplan-Meier cumulative incidence of radiation-associated adverse events. Results: A total of 4522 (7.1%) patients received brachytherapy (50.2% multichannel vs 48.7% single-channel applicator).more » The overall risk of infectious adverse events was higher after brachytherapy than after EBRT (odds ratio [OR] = 1.21; 95% confidence interval [CI] 1.09-1.34, P<.001). However, over time, the frequency of infectious adverse events after brachytherapy decreased, from 17.3% in 2003 to 11.6% in 2012, and was stable after EBRT at 9.7%. Beyond 2007, there were no longer excess infections with brachytherapy (P=.97). The overall risk of noninfectious adverse events was higher after brachytherapy than after EBRT (OR=2.27; 95% CI 2.09-2.47, P<.0001). Over time, the frequency of noninfectious adverse events detected increased: after multichannel brachytherapy, from 9.1% in 2004 to 18.9% in 2012 (Ptrend = .64); single-channel brachytherapy, from 12.8% to 29.8% (Ptrend<.001); and EBRT, from 6.1% to 10.3% (Ptrend<.0001). The risk was significantly higher with single-channel than with multichannel brachytherapy (hazard ratio = 1.32; 95% CI 1.03-1.69, P=.03). Of noninfectious adverse events, 70.9% were seroma. Seroma significantly increased breast pain risk (P<.0001). Patients with underlying diabetes, cardiovascular disease, and treatment with chemotherapy had increased infectious and noninfectious adverse events. The 5-year incidences of fat necrosis, breast pain, and rib fracture were slightly higher after brachytherapy than after EBRT (13.7% vs 8.1%, 19.4% vs 16.0%, and 1.6% vs 1.3%, respectively), but the risks were not significantly different for multichannel versus single-channel applicators. Conclusion: Toxicities after breast brachytherapy were distinct from those after EBRT. Temporal toxicity trends may reflect changing technology and evolving practitioner experience with brachytherapy.« less

Making A D-Latch Sensitive To Alpha Particles

NASA Technical Reports Server (NTRS)

Buehler, Martin G.; Blaes, Brent R.; Nixon, Robert H.

1994-01-01

Standard complementary metal oxide/semiconductor (CMOS) D-latch integrated circuit modified to increase susceptibility to single-event upsets (SEU's) (changes in logic state) caused by impacts of energetic alpha particles. Suitable for use in relatively inexpensive bench-scale SEU tests of itself and of related integrated circuits like static random-access memories.

Silicon Power MOSFETs

NASA Technical Reports Server (NTRS)

Lauenstein, Jean-Marie; Casey, Megan; Campola, Michael; Ladbury, Raymond; Label, Kenneth; Wilcox, Ted; Phan, Anthony; Kim, Hak; Topper, Alyson

2017-01-01

Recent work for the NASA Electronic Parts and Packaging Program Power MOSFET task is presented. The Task technology focus, roadmap, and partners are given. Recent single-event effect test results on commercial, automotive, and radiation hardened trench power MOSFETs are summarized with an emphasis on risk of using commercial and automotive trench-gate power MOSFETs in space applications.

CRIS Cyber Range Lexicon, Version 1.0

DTIC Science & Technology

2015-11-10

Figure 4: Planes and Teams...Technology (S&T) experimentation , Developmental and Operational Test and Evaluation (DT&E, OT&E), cyber force training, and mission rehearsal. To...an Event in cyber space . A Range contains a set of assets and capabilities located at one or more sites. A Range has a single Range Manager. A

Trends in Device SEE Susceptibility from Heavy Ions

NASA Technical Reports Server (NTRS)

Nichols, D. K.; Coss, J. R.; McCarty, K. P.; Schwartz, H. R.; Swift, G. M.; Watson, R. K.; Koga, R.; Crain, W. R.; Crawford, K. B.; Hansel, S. J.

1995-01-01

The sixth set of heavy ion single event effects (SEE) test data have been collected since the last IEEE publications in December issues of IEEE - Nuclear Science Transactions for 1985, 1987, 1989, 1991, and the IEEE Workshop Record, 1993. Trends in SEE susceptibility (including soft errors and latchup) for state-of- are evaluated.

Comparison of CREME (cosmic-ray effects on microelectronics) model LET (linear energy transfer) spaceflight dosimetry data

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

Letaw, J.R.; Adams, J.H.

The galactic cosmic radiation (GCR) component of space radiation is the dominant cause of single-event phenomena in microelectronic circuits when Earth's magnetic shielding is low. Spaceflights outside the magnetosphere and in high inclination orbits are examples of such circumstances. In high-inclination orbits, low-energy (high LET) particles are transmitted through the field only at extreme latitudes, but can dominate the orbit-averaged dose. GCR is an important part of the radiation dose to astronauts under the same conditions. As a test of the CREME environmental model and particle transport codes used to estimate single event upsets, we have compiled existing measurements ofmore » HZE doses were compiled where GCR is expected to be important: Apollo 16 and 17, Skylab, Apollo Soyuz Test Project, and Kosmos 782. The LET spectra, due to direct ionization from GCR, for each of these missions has been estimated. The resulting comparisons with data validate the CREME model predictions of high-LET galactic cosmic-ray fluxes to within a factor of two. Some systematic differences between the model and data are identified.« less

Workup for Perinatal Stroke Does Not Predict Recurrence.

PubMed

Lehman, Laura L; Beaute, Jeanette; Kapur, Kush; Danehy, Amy R; Bernson-Leung, Miya E; Malkin, Hayley; Rivkin, Michael J; Trenor, Cameron C

2017-08-01

Perinatal stroke, including neonatal and presumed perinatal presentation, represents the age in childhood in which stroke occurs most frequently. The roles of thrombophilia, arteriopathy, and cardiac anomalies in perinatal ischemic stroke are currently unclear. We took a uniform approach to perinatal ischemic stroke evaluation to study these risk factors and their association with recurrent stroke. We reviewed records of perinatal stroke patients evaluated from August 2008 to February 2016 at a single referral center. Demographics, echocardiography, arterial imaging, and thrombophilia testing were collected. Statistical analysis was performed using Fisher exact test. Across 215 cases, the median follow-up was 3.17 years (1.49, 6.46). Females comprised 42.8% of cases. Age of presentation was neonatal (110, 51.2%) or presumed perinatal (105, 48.8%). The median age at diagnosis was 2.9 days (interquartile range, 2.0-9.9) for neonatal stroke and 12.9 months (interquartile range, 8.7-32.8) for presumed perinatal stroke. Strokes were classified as arterial (149, 69.3%), venous (60, 27.9%), both (4, 1.9%), or uncertain (2, 0.9%) by consensus imaging review. Of the 215 cases, there were 6 (2.8%) recurrent ischemic cerebrovascular events. Abnormal thrombophilia testing was not associated with recurrent stroke, except for a single patient with combined antithrombin deficiency and protein C deficiency. After excluding venous events, 155 patients were evaluated for arteriopathy and cardioembolic risk factors; neither was associated with recurrent stroke. Positive family history of thrombosis was not predictive of abnormal thrombophilia testing. Thrombophilia, arteriopathy, or cardioembolic risk factors were not predictive of recurrent events after perinatal stroke. Thrombophilia evaluation in perinatal stroke should only rarely be considered. © 2017 American Heart Association, Inc.

Sequential parallel comparison design with binary and time-to-event outcomes.

PubMed

Silverman, Rachel Kloss; Ivanova, Anastasia; Fine, Jason

2018-04-30

Sequential parallel comparison design (SPCD) has been proposed to increase the likelihood of success of clinical trials especially trials with possibly high placebo effect. Sequential parallel comparison design is conducted with 2 stages. Participants are randomized between active therapy and placebo in stage 1. Then, stage 1 placebo nonresponders are rerandomized between active therapy and placebo. Data from the 2 stages are pooled to yield a single P value. We consider SPCD with binary and with time-to-event outcomes. For time-to-event outcomes, response is defined as a favorable event prior to the end of follow-up for a given stage of SPCD. We show that for these cases, the usual test statistics from stages 1 and 2 are asymptotically normal and uncorrelated under the null hypothesis, leading to a straightforward combined testing procedure. In addition, we show that the estimators of the treatment effects from the 2 stages are asymptotically normal and uncorrelated under the null and alternative hypothesis, yielding confidence interval procedures with correct coverage. Simulations and real data analysis demonstrate the utility of the binary and time-to-event SPCD. Copyright © 2018 John Wiley & Sons, Ltd.

Statistical analysis of secondary particle distributions in relativistic nucleus-nucleus collisions

NASA Technical Reports Server (NTRS)

Mcguire, Stephen C.

1987-01-01

The use is described of several statistical techniques to characterize structure in the angular distributions of secondary particles from nucleus-nucleus collisions in the energy range 24 to 61 GeV/nucleon. The objective of this work was to determine whether there are correlations between emitted particle intensity and angle that may be used to support the existence of the quark gluon plasma. The techniques include chi-square null hypothesis tests, the method of discrete Fourier transform analysis, and fluctuation analysis. We have also used the method of composite unit vectors to test for azimuthal asymmetry in a data set of 63 JACEE-3 events. Each method is presented in a manner that provides the reader with some practical detail regarding its application. Of those events with relatively high statistics, Fe approaches 0 at 55 GeV/nucleon was found to possess an azimuthal distribution with a highly non-random structure. No evidence of non-statistical fluctuations was found in the pseudo-rapidity distributions of the events studied. It is seen that the most effective application of these methods relies upon the availability of many events or single events that possess very high multiplicities.

Single Event Burnout in DC-DC Converters for the LHC Experiments

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

Claudio H. Rivetta et al.

High voltage transistors in DC-DC converters are prone to catastrophic Single Event Burnout in the LHC radiation environment. This paper presents a systematic methodology to analyze single event effects sensitivity in converters and proposes solutions based on de-rating input voltage and output current or voltage.

Meadow voles, Microtus pennsylvanicus, have the capacity to recall the "what", "where", and "when" of a single past event.

PubMed

Ferkin, Michael H; Combs, Amy; delBarco-Trillo, Javier; Pierce, Andrew A; Franklin, Stan

2008-01-01

Some non-human animals may possess the ability to recall the "what", "where", and "when" of a single past event. We tested the hypothesis that male meadow voles possess the capacity to recall the "what", "where", and "when" of a single past event associated with mate selection in two experiments. Briefly, male voles were allowed to explore an apparatus that contained two chambers. One chamber contained a day-20 pregnant female (24 h prepartum). The other chamber contained a sexually mature female that was neither pregnant nor lactating (REF female). Twenty-four hour after the exposure, the males were placed in the same apparatus, which was empty and clean. At this time, the pregnant female would have entered postpartum estrus (PPE), a period of heightened sexual receptivity. Males initially chose and spent significantly more time investigating the chamber that originally housed the pregnant female (now a PPE female) than the chamber that originally housed the REF female. Male voles also explored an apparatus containing a chamber with a PPE female and one chamber containing a REF female. Twenty-four hour later, males were placed into an empty and clean apparatus. The males did not display an initial choice and they spent similar amounts of time investigating the chamber that originally housed the PPE female (now a lactating female) and the chamber that originally housed the REF female. The results of these and additional experiments suggest that male voles may have the capacity to recall the "what", "where", and "when" of a single past event, which may allow males to remember the location of females who would currently be in heightened states of sexual receptivity.

Generation and Inheritance of Targeted Mutations in Potato (Solanum tuberosum L.) Using the CRISPR/Cas System

PubMed Central

Butler, Nathaniel M.; Atkins, Paul A.; Voytas, Daniel F.; Douches, David S.

2015-01-01

Genome editing using sequence-specific nucleases (SSNs) offers an alternative approach to conventional genetic engineering and an opportunity to extend the benefits of genetic engineering in agriculture. Currently available SSN platforms, such as zinc finger nucleases (ZFNs), transcription activator-like effector nucleases (TALENs), and CRISPR/Cas (clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated systems (Cas)) have been used in a range of plant species for targeted mutagenesis via non-homologous end joining (NHEJ) are just beginning to be explored in crops such as potato (Solanum tuberosum Group Tuberosum L.). In this study, CRISPR/Cas reagents expressing one of two single-guide RNA (sgRNA) targeting the potato ACETOLACTATE SYNTHASE1 (StALS1) gene were tested for inducing targeted mutations in callus and stable events of diploid and tetraploid potato using Agrobacterium-mediated transformation with either a conventional T-DNA or a modified geminivirus T-DNA. The percentage of primary events with targeted mutations ranged from 3–60% per transformation and from 0–29% above an expected threshold based on the number of ALS alleles. Primary events with targeted mutation frequencies above the expected threshold were used for mutation cloning and inheritance studies using clonal propagation and crosses or selfing. Four of the nine primary events used for mutation cloning had more than one mutation type, and eight primary events contained targeted mutations that were maintained across clonal generations. Somatic mutations were most evident in the diploid background with three of the four primary events having more than two mutation types at a single ALS locus. Conversely, in the tetraploid background, four of the five candidates carried only one mutation type. Single targeted mutations were inherited through the germline of both diploid and tetraploid primary events with transmission percentages ranging from 87–100%. This demonstration of CRISPR/Cas in potato extends the range of plant species modified using CRISPR/Cas and provides a framework for future studies. PMID:26657719

Generation and Inheritance of Targeted Mutations in Potato (Solanum tuberosum L.) Using the CRISPR/Cas System.

PubMed

Butler, Nathaniel M; Atkins, Paul A; Voytas, Daniel F; Douches, David S

2015-01-01

Genome editing using sequence-specific nucleases (SSNs) offers an alternative approach to conventional genetic engineering and an opportunity to extend the benefits of genetic engineering in agriculture. Currently available SSN platforms, such as zinc finger nucleases (ZFNs), transcription activator-like effector nucleases (TALENs), and CRISPR/Cas (clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated systems (Cas)) have been used in a range of plant species for targeted mutagenesis via non-homologous end joining (NHEJ) are just beginning to be explored in crops such as potato (Solanum tuberosum Group Tuberosum L.). In this study, CRISPR/Cas reagents expressing one of two single-guide RNA (sgRNA) targeting the potato ACETOLACTATE SYNTHASE1 (StALS1) gene were tested for inducing targeted mutations in callus and stable events of diploid and tetraploid potato using Agrobacterium-mediated transformation with either a conventional T-DNA or a modified geminivirus T-DNA. The percentage of primary events with targeted mutations ranged from 3-60% per transformation and from 0-29% above an expected threshold based on the number of ALS alleles. Primary events with targeted mutation frequencies above the expected threshold were used for mutation cloning and inheritance studies using clonal propagation and crosses or selfing. Four of the nine primary events used for mutation cloning had more than one mutation type, and eight primary events contained targeted mutations that were maintained across clonal generations. Somatic mutations were most evident in the diploid background with three of the four primary events having more than two mutation types at a single ALS locus. Conversely, in the tetraploid background, four of the five candidates carried only one mutation type. Single targeted mutations were inherited through the germline of both diploid and tetraploid primary events with transmission percentages ranging from 87-100%. This demonstration of CRISPR/Cas in potato extends the range of plant species modified using CRISPR/Cas and provides a framework for future studies.

Mitigating Upsets in SRAM-Based FPGAs from the Xilinx Virtex 2 Family

NASA Technical Reports Server (NTRS)

Swift, G. M.; Yui, C. C.; Carmichael, C.; Koga, R.; George, J. S.

2003-01-01

Static random access memory (SRAM) upset rates in field programmable gate arrays (FPGAs) from the Xilinx Virtex 2 family have been tested for radiation effects on configuration memory, block RAM and the power-on-reset (POR) and SelectMAP single event functional interrupts (SEFIs). Dynamic testing has shown the effectiveness and value of Triple Module Redundancy (TMR) and partial reconfiguration when used in conjunction. Continuing dynamic testing for more complex designs and other Virtex 2 capabilities (i.e., I/O standards, digital clock managers (DCM), etc.) is scheduled.

Single-Event Effect Report for EPC Series eGaN FETs: EPC1001, EPC1010, EPC1014, EPC1012

NASA Technical Reports Server (NTRS)

Scheick, Leif

2013-01-01

Heavy ion testing of newly available GaN FETs from EPC were tested in March of 2012 at TAM. The EPC1010, EPC1001, EPC1012, and EPC1014 were tested for general radiation response from gold and xenon ions. Overall the devices showed radiation degradation commensurate with breakdown in isolation oxides, and similar testing by EPC and Microsemi agrees with these data. These devices were the first generation production of the device called Gen1. Gen2 parts are scheduled for later in the third quarter of FY2012

Latest trends in parts SEP susceptibility from heavy ions

NASA Technical Reports Server (NTRS)

Nichols, Donald K.; Smith, L. S.; Soli, George A.; Koga, R.; Kolasinski, W. A.

1989-01-01

JPL and Aerospace have collected a third set of heavy-ion single-event phenomena (SEP) test data since their last joint IEEE publications in December 1985 and December 1987. Trends in SEP susceptibility (e.g., soft errors and latchup) for state-of-the-art parts are presented. Results of the study indicate that hard technologies and unacceptably soft technologies can be flagged. In some instances, specific tested parts can be taken as candidates for key microprocessors or memories. As always with radiation test data, specific test data for qualified flight parts is recommended for critical applications.

FPGAs in Space Environment and Design Techniques

NASA Technical Reports Server (NTRS)

Katz, Richard B.; Day, John H. (Technical Monitor)

2001-01-01

This viewgraph presentation gives an overview of Field Programmable Gate Arrays (FPGA) in the space environment and design techniques. Details are given on the effects of the space radiation environment, total radiation dose, single event upset, single event latchup, single event transient, antifuse technology and gate rupture, proton upsets and sensitivity, and loss of functionality.

An Updated Perspective of Single Event Gate Rupture and Single Event Burnout in Power MOSFETs

NASA Astrophysics Data System (ADS)

Titus, Jeffrey L.

2013-06-01

Studies over the past 25 years have shown that heavy ions can trigger catastrophic failure modes in power MOSFETs [e.g., single-event gate rupture (SEGR) and single-event burnout (SEB)]. In 1996, two papers were published in a special issue of the IEEE Transaction on Nuclear Science [Johnson, Palau, Dachs, Galloway and Schrimpf, “A Review of the Techniques Used for Modeling Single-Event Effects in Power MOSFETs,” IEEE Trans. Nucl. Sci., vol. 43, no. 2, pp. 546-560, April. 1996], [Titus and Wheatley, “Experimental Studies of Single-Event Gate Rupture and Burnout in Vertical Power MOSFETs,” IEEE Trans. Nucl. Sci., vol. 43, no. 2, pp. 533-545, Apr. 1996]. Those two papers continue to provide excellent information and references with regard to SEB and SEGR in vertical planar MOSFETs. This paper provides updated references/information and provides an updated perspective of SEB and SEGR in vertical planar MOSFETs as well as provides references/information to other device types that exhibit SEB and SEGR effects.

Theory of single-molecule controlled rotation experiments, predictions, tests, and comparison with stalling experiments in F1-ATPase.

PubMed

Volkán-Kacsó, Sándor; Marcus, Rudolph A

2016-10-25

A recently proposed chemomechanical group transfer theory of rotary biomolecular motors is applied to treat single-molecule controlled rotation experiments. In these experiments, single-molecule fluorescence is used to measure the binding and release rate constants of nucleotides by monitoring the occupancy of binding sites. It is shown how missed events of nucleotide binding and release in these experiments can be corrected using theory, with F 1 -ATP synthase as an example. The missed events are significant when the reverse rate is very fast. Using the theory the actual rate constants in the controlled rotation experiments and the corrections are predicted from independent data, including other single-molecule rotation and ensemble biochemical experiments. The effective torsional elastic constant is found to depend on the binding/releasing nucleotide, and it is smaller for ADP than for ATP. There is a good agreement, with no adjustable parameters, between the theoretical and experimental results of controlled rotation experiments and stalling experiments, for the range of angles where the data overlap. This agreement is perhaps all the more surprising because it occurs even though the binding and release of fluorescent nucleotides is monitored at single-site occupancy concentrations, whereas the stalling and free rotation experiments have multiple-site occupancy.

Single-Event Effect Performance of a Conductive-Bridge Memory EEPROM

NASA Technical Reports Server (NTRS)

Chen, Dakai; Wilcox, Edward; Berg, Melanie; Kim, Hak; Phan, Anthony; Figueiredo, Marco; Seidleck, Christina; LaBel, Kenneth

2015-01-01

We investigated the heavy ion SEE characteristics of an EEPROM based on CBRAM technology. SEFI is the dominant type of SEE for each operating mode (standby, read-only, write/read). We also observed single bit upsets in the CBRAM cell, during write/read tests. the SEULET threshold is between 10 and 20 MeV * sq cm/mg, with an upper fluence limit of 3 × 10(exp 6) cm(exp -2) at 10 MeV * sq cm/mg. In the stand by mode, the CBRAM array appears immune to bit upsets.

A clinical study of the LiVac laparoscopic liver retractor system.

PubMed

Gan, Philip; Bingham, Judy

2016-02-01

All retractors for laparoscopic operations on the gallbladder or stomach apply an upward force to the under-surface of the liver or gallbladder, most requiring an additional skin incision. The LiVac laparoscopic liver retractor system (LiVac retractor) comprises a soft silicone ring attached to suction tubing and connected to a regulated source of suction. The suction tubing extends alongside existing ports. When placed between the liver and diaphragm, and suction applied, a vacuum is created within the ring, keeping these in apposition. Following successful proof-of-concept animal testing, a clinical study was conducted to evaluate the performance and safety of the retractor in patients. The study was a dual-centre, single-surgeon, open-label study and recruited ten patients scheduled to undergo routine upper abdominal laparoscopic surgery including cholecystectomy, primary gastric banding surgery or fundoplication. The study was conducted at two sites and was approved by the institutions' ethics committees. The primary objective of the study was to evaluate the performance of the LiVac retractor in patients undergoing upper abdominal single- or multi-port laparoscopic surgery. Performance was measured by the attainment of milestones for the retractor and accessory bevel, where used, and safety outcomes through the recording of adverse events, physical parameters, pain scales, blood tests and a post-operative liver ultrasound. The LiVac retractor achieved both primary and secondary performance and safety objectives in all patients. No serious adverse events and no device-related adverse events or device deficiencies were reported. The LiVac retractor achieved effective liver retraction without clinically significant trauma and has potential application in multi- or single-port laparoscopic upper abdominal surgery. As a separate incision is not required, the use of the LiVac retractor in multi-port surgery therefore reduces the number of incisions.

What Dominates a Craters Size, the Largest Single Explosion of the Formation Process or the Cumulative Energy of Many? Results of Multiblast Crater Evolution Experiments

NASA Astrophysics Data System (ADS)

Sonder, I.; Graettinger, A. H.; Valentine, G. A.

2015-12-01

Craters of explosive volcanic eruptions are products of many explosions. Such craters are different than products of single events such as meteorite impacts or those produced by military testing because they typically result from multiple, rather than single, explosions. We analyzed the evolution of experimental craters that were created by several detonations of chemical explosives in layered aggregates. A method to calculate an effective explosion depth for non-flat topography (e.g. for explosions below existing craters) is derived, showing how multi-blast crater sizes differ from the single blast case. It is shown that sizes of natural caters (radii, volumes) are not characteristic of the number of explosions, and therefore not characteristic for the total acting energy, that formed a crater. Also the crater size is not simply related to the largest explosion in a sequence, but depends upon that explosion and the energy of that single blast and on the cumulative energy of all blasts that formed the crater. The two energies can be combined to form an effective number of explosions that is characteristic for the crater evolution. The multi-blast crater size evolution implies that it is not correct to estimate explosion energy of volcanic events from crater size using previously published relationships that were derived for single blast cases.

Untangling Psychiatric Comorbidity in Young Children Who Experienced Single, Repeated, or Hurricane Katrina Traumatic Events

ERIC Educational Resources Information Center

Scheeringa, Michael S.

2015-01-01

Background: In individuals with posttraumatic stress disorder (PTSD), 70-90 % have at least one comorbid non-PTSD disorder. Objective: This study tested several hypotheses to untangle comorbidity issues. Following McMillen et al. ("Compr Psychiatry" 43(6):478-485, 2002), we hypothesized that few non-PTSD disorders would arise following…

Defect-sensitivity analysis of an SEU immune CMOS logic family

NASA Technical Reports Server (NTRS)

Ingermann, Erik H.; Frenzel, James F.

1992-01-01

Fault testing of resistive manufacturing defects is done on a recently developed single event upset immune logic family. Resistive ranges and delay times are compared with those of traditional CMOS logic. Reaction of the logic to these defects is observed for a NOR gate, and an evaluation of its ability to cope with them is determined.

Using HFire for spatial modeling of fire in shrublands

Treesearch

Seth H. Peterson; Marco E. Morais; Jean M. Carlson; Philip E. Dennison; Dar A. Roberts; Max A. Moritz; David R. Weise

2009-01-01

An efficient raster fire-spread model named HFire is introduced. HFire can simulate single-fire events or long-term fire regimes, using the same fire-spread algorithm. This paper describes the HFire algorithm, benchmarks the model using a standard set of tests developed for FARSITE, and compares historical and predicted fire spread perimeters for three southern...

Microcircuit radiation effects databank

NASA Technical Reports Server (NTRS)

1983-01-01

Radiation test data submitted by many testers is collated to serve as a reference for engineers who are concerned with and have some knowledge of the effects of the natural radiation environment on microcircuits. Total dose damage information and single event upset cross sections, i.e., the probability of a soft error (bit flip) or of a hard error (latchup) are presented.

Serial Learning in Rats: A Test of Three Hypotheses

ERIC Educational Resources Information Center

Capaldi, E. J.; Miller, Ronald Mellado

2004-01-01

Findings obtained by providing rats with a single fixed series of events, A-B-C-..., often are equally compatible with three alternative serial learning interpretations: that the signal for items is (A) their position in the series (position view), (B) the prior item of the series (chaining view), and (C) one, two, or more prior items of the…

Data-Enabled Quantification of Aluminum Microstructural Damage Under Tensile Loading

NASA Astrophysics Data System (ADS)

Wayne, Steven F.; Qi, G.; Zhang, L.

2016-08-01

The study of material failure with digital analytics is in its infancy and offers a new perspective to advance our understanding of damage initiation and evolution in metals. In this article, we study the failure of aluminum using data-enabled methods, statistics and data mining. Through the use of tension tests, we establish a multivariate acoustic-data matrix of random damage events, which typically are not visible and are very difficult to measure due to their variability, diversity and interactivity during damage processes. Aluminium alloy 6061-T651 and single crystal aluminium with a (111) orientation were evaluated by comparing the collection of acoustic signals from damage events caused primarily by slip in the single crystal and multimode fracture of the alloy. We found the resulting acoustic damage-event data to be large semi-structured volumes of Big Data with the potential to be mined for information that describes the materials damage state under strain. Our data-enabled analyses has allowed us to determine statistical distributions of multiscale random damage that provide a means to quantify the material damage state.

A Carbon Nanotube Reporter of miRNA Hybridization Events In Vivo

PubMed Central

Harvey, Jackson D.; Jena, Prakrit V.; Baker, Hanan A.; Zerze, Gül H.; Williams, Ryan M.; Galassi, Thomas V.; Roxbury, Daniel; Mittal, Jeetain

2017-01-01

MicroRNAs and other small oligonucleotides in biofluids are promising disease biomarkers, yet conventional assays require complex processing steps that are unsuitable for point-of-care testing or for implantable or wearable sensors. Single-walled carbon nanotubes are an ideal material for implantable sensors, owing to their emission in the near-infrared spectral region, photostability and exquisite sensitivity. Here, we report an engineered carbon-nanotube-based sensor capable of real-time optical quantification of hybridization events of microRNA and other oligonucleotides. The mechanism of the sensor arises from competitive effects between displacement of both oligonucleotide charge groups and water from the nanotube surface, which result in a solvatochromism-like response. The sensor, which allows for detection via single-molecule sensor elements and for multiplexing by using multiple nanotube chiralities, can monitor toehold-based strand-displacement events, which reverse the sensor response and regenerate the sensor complex. We also show that the sensor functions in whole urine and serum, and can non-invasively measure DNA and microRNA after implantation in live mice. PMID:28845337

A Carbon Nanotube Reporter of miRNA Hybridization Events In Vivo.

PubMed

Harvey, Jackson D; Jena, Prakrit V; Baker, Hanan A; Zerze, Gül H; Williams, Ryan M; Galassi, Thomas V; Roxbury, Daniel; Mittal, Jeetain; Heller, Daniel A

2017-01-01

MicroRNAs and other small oligonucleotides in biofluids are promising disease biomarkers, yet conventional assays require complex processing steps that are unsuitable for point-of-care testing or for implantable or wearable sensors. Single-walled carbon nanotubes are an ideal material for implantable sensors, owing to their emission in the near-infrared spectral region, photostability and exquisite sensitivity. Here, we report an engineered carbon-nanotube-based sensor capable of real-time optical quantification of hybridization events of microRNA and other oligonucleotides. The mechanism of the sensor arises from competitive effects between displacement of both oligonucleotide charge groups and water from the nanotube surface, which result in a solvatochromism-like response. The sensor, which allows for detection via single-molecule sensor elements and for multiplexing by using multiple nanotube chiralities, can monitor toehold-based strand-displacement events, which reverse the sensor response and regenerate the sensor complex. We also show that the sensor functions in whole urine and serum, and can non-invasively measure DNA and microRNA after implantation in live mice.

CRISPR-directed mitotic recombination enables genetic mapping without crosses.

PubMed

Sadhu, Meru J; Bloom, Joshua S; Day, Laura; Kruglyak, Leonid

2016-05-27

Linkage and association studies have mapped thousands of genomic regions that contribute to phenotypic variation, but narrowing these regions to the underlying causal genes and variants has proven much more challenging. Resolution of genetic mapping is limited by the recombination rate. We developed a method that uses CRISPR (clustered, regularly interspaced, short palindromic repeats) to build mapping panels with targeted recombination events. We tested the method by generating a panel with recombination events spaced along a yeast chromosome arm, mapping trait variation, and then targeting a high density of recombination events to the region of interest. Using this approach, we fine-mapped manganese sensitivity to a single polymorphism in the transporter Pmr1. Targeting recombination events to regions of interest allows us to rapidly and systematically identify causal variants underlying trait differences. Copyright © 2016, American Association for the Advancement of Science.

Single event burnout sensitivity of embedded field effect transistors

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

Koga, R.; Crain, S.H.; Crawford, K.B.

Observations of single event burnout (SEB) in embedded field effect transistors are reported. Both SEB and other single event effects are presented for several pulse width modulation and high frequency devices. The microscope has been employed to locate and to investigate the damaged areas. A model of the damage mechanism based on the results so obtained is described.

Single event burnout sensitivity of embedded field effect transistors

NASA Astrophysics Data System (ADS)

Koga, R.; Crain, S. H.; Crawford, K. B.; Yu, P.; Gordon, M. J.

1999-12-01

Observations of single event burnout (SEB) in embedded field effect transistors are reported. Both SEB and other single event effects are presented for several pulse width modulation and high frequency devices. The microscope has been employed to locate and to investigate the damaged areas. A model of the damage mechanism based on the results so obtained is described.

Twelve- to 14-Month-Old Infants Can Predict Single-Event Probability with Large Set Sizes

ERIC Educational Resources Information Center

Denison, Stephanie; Xu, Fei

2010-01-01

Previous research has revealed that infants can reason correctly about single-event probabilities with small but not large set sizes (Bonatti, 2008; Teglas "et al.", 2007). The current study asks whether infants can make predictions regarding single-event probability with large set sizes using a novel procedure. Infants completed two trials: A…

Rapid formation of a modern bedrock canyon by a single flood event

NASA Astrophysics Data System (ADS)

Lamb, Michael P.; Fonstad, Mark A.

2010-07-01

Deep river canyons are thought to form slowly over geological time (see, for example, ref. 1), cut by moderate flows that reoccur every few years. In contrast, some of the most spectacular canyons on Earth and Mars were probably carved rapidly during ancient megaflood events. Quantification of the flood discharge, duration and erosion mechanics that operated during such events is hampered because we lack modern analogues. Canyon Lake Gorge, Texas, was carved in 2002 during a single catastrophic flood. The event offers a rare opportunity to analyse canyon formation and test palaeo-hydraulic-reconstruction techniques under known topographic and hydraulic conditions. Here we use digital topographic models and visible/near-infrared aerial images from before and after the flood, discharge measured during the event, field measurements and sediment-transport modelling to show that the flood moved metre-sized boulders, excavated ~7m of limestone and transformed a soil-mantled valley into a bedrock canyon in just ~3days. We find that canyon morphology is strongly dependent on rock type: plucking of limestone blocks produced waterfalls, inner channels and bedrock strath terraces, whereas abrasion of cemented alluvium sculpted walls, plunge pools and streamlined islands. Canyon formation was so rapid that erosion might have been limited by the ability of the flow to transport sediment. We suggest that our results might improve hydraulic reconstructions of similar megafloods on Earth and Mars.

Adaptive Neural Network-Based Event-Triggered Control of Single-Input Single-Output Nonlinear Discrete-Time Systems.

PubMed

Sahoo, Avimanyu; Xu, Hao; Jagannathan, Sarangapani

2016-01-01

This paper presents a novel adaptive neural network (NN) control of single-input and single-output uncertain nonlinear discrete-time systems under event sampled NN inputs. In this control scheme, the feedback signals are transmitted, and the NN weights are tuned in an aperiodic manner at the event sampled instants. After reviewing the NN approximation property with event sampled inputs, an adaptive state estimator (SE), consisting of linearly parameterized NNs, is utilized to approximate the unknown system dynamics in an event sampled context. The SE is viewed as a model and its approximated dynamics and the state vector, during any two events, are utilized for the event-triggered controller design. An adaptive event-trigger condition is derived by using both the estimated NN weights and a dead-zone operator to determine the event sampling instants. This condition both facilitates the NN approximation and reduces the transmission of feedback signals. The ultimate boundedness of both the NN weight estimation error and the system state vector is demonstrated through the Lyapunov approach. As expected, during an initial online learning phase, events are observed more frequently. Over time with the convergence of the NN weights, the inter-event times increase, thereby lowering the number of triggered events. These claims are illustrated through the simulation results.

Testing the Speed of Gravitational Waves over Cosmological Distances with Strong Gravitational Lensing.

PubMed

Collett, Thomas E; Bacon, David

2017-03-03

Probing the relative speeds of gravitational waves and light acts as an important test of general relativity and alternative theories of gravity. Measuring the arrival time of gravitational waves (GWs) and electromagnetic (EM) counterparts can be used to measure the relative speeds, but only if the intrinsic time lag between emission of the photons and gravitational waves is well understood. Here we suggest a method that does not make such an assumption, using future strongly lensed GW events and EM counterparts; Biesiada et al. [J. Cosmol. Astropart. Phys.10 (2014) 080JCAPBP1475-751610.1088/1475-7516/2014/10/080] forecast that 50-100 strongly lensed GW events will be observed each year with the Einstein Telescope. A single strongly lensed GW event would produce robust constraints on c_{GW}/c_{γ} at the 10^{-7} level, if a high-energy EM counterpart is observed within the field of view of an observing γ-ray burst monitor.

First observations of power MOSFET burnout with high energy neutrons

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

Oberg, D.L.; Wert, J.L.; Normand, E.

Single event burnout was seen in power MOSFETs exposed to high energy neutrons. Devices with rated voltage {ge}400 volts exhibited burnout at substantially less than the rated voltage. Tests with high energy protons gave similar results. Burnout was also seen in limited tests with lower energy protons and neutrons. Correlations with heavy-ion data are discussed. Accelerator proton data gave favorable comparisons with burnout rates measured on the APEX spacecraft. Implications for burnout at lower altitudes are also discussed.

First observations of power MOSFET burnout with high energy neutrons

NASA Astrophysics Data System (ADS)

Oberg, D. L.; Wert, J. L.; Normand, E.; Majewski, P. P.; Wender, S. A.

1996-12-01

Single event burnout was seen in power MOSFETs exposed to high energy neutrons. Devices with rated voltage /spl ges/400 volts exhibited burnout at substantially less than the rated voltage. Tests with high energy protons gave similar results. Burnout was also seen in limited tests with lower energy protons and neutrons. Correlations with heavy-ion data are discussed. Accelerator proton data gave favorable comparisons with burnout rates measured on the APEX spacecraft. Implications for burnout at lower altitudes are also discussed.

Use of a krypton isotope for rapid ion changeover at the Lawrence Berkeley Laboratory 88-inch cyclotron

NASA Technical Reports Server (NTRS)

Soli, George A.; Nichols, Donald K.

1989-01-01

An isotope of krypton, Kr86, has been combined with a mix of Ar, Ne, and N ions at the electron cyclotron resonance (ECR) source, at the Lawrence Berkeley Laboratory cyclotron, to provide rapid ion changeover in Single Event Phenomena (SEP) testing. The new technique has been proved out successfully by a recent Jet Propulsion Laboratory (JPL) test in which it was found that there was no measurable contamination from other isotopes.

Microcircuit radiation effects databank

NASA Technical Reports Server (NTRS)

1983-01-01

This databank is the collation of radiation test data submitted by many testers and serves as a reference for engineers who are concerned with and have some knowledge of the effects of the natural radiation environment on microcircuits. It contains radiation sensitivity results from ground tests and is divided into two sections. Section A lists total dose damage information, and section B lists single event upset cross sections, I.E., the probability of a soft error (bit flip) or of a hard error (latchup).

Natural environment support guidelines for Space Shuttle tests and operations

NASA Technical Reports Server (NTRS)

Carter, E. A.; Brown, S. C.

1974-01-01

The present work outlines the general concept as to how natural environment guidelines will be developed for Space Shuttle activities. The following six categories that might need natural environment support are single out: development tests; preliminary operations and prelaunch; launch to orbit; orbital mission and operations; deorbit, entry, and landing; ferry flights. An example of detailed event requirements for decisions to launch is given. Some artist's conceptions of proposed launch complexes at Kennedy Space Center and Vandenberg AFB are shown.

Phase II Trials for Heterogeneous Patient Populations with a Time-to-Event Endpoint.

PubMed

Jung, Sin-Ho

2017-07-01

In this paper, we consider a single-arm phase II trial with a time-to-event end-point. We assume that the study population has multiple subpopulations with different prognosis, but the study treatment is expected to be similarly efficacious across the subpopulations. We review a stratified one-sample log-rank test and present its sample size calculation method under some practical design settings. Our sample size method requires specification of the prevalence of subpopulations. We observe that the power of the resulting sample size is not very sensitive to misspecification of the prevalence.

Anthology of the Development of Radiation Transport Tools as Applied to Single Event Effects

NASA Astrophysics Data System (ADS)

Reed, R. A.; Weller, R. A.; Akkerman, A.; Barak, J.; Culpepper, W.; Duzellier, S.; Foster, C.; Gaillardin, M.; Hubert, G.; Jordan, T.; Jun, I.; Koontz, S.; Lei, F.; McNulty, P.; Mendenhall, M. H.; Murat, M.; Nieminen, P.; O'Neill, P.; Raine, M.; Reddell, B.; Saigné, F.; Santin, G.; Sihver, L.; Tang, H. H. K.; Truscott, P. R.; Wrobel, F.

2013-06-01

This anthology contains contributions from eleven different groups, each developing and/or applying Monte Carlo-based radiation transport tools to simulate a variety of effects that result from energy transferred to a semiconductor material by a single particle event. The topics span from basic mechanisms for single-particle induced failures to applied tasks like developing websites to predict on-orbit single event failure rates using Monte Carlo radiation transport tools.

A statistical study of single crest phenomenon in the equatorial ionospheric anomaly region using Swarm A satellite

NASA Astrophysics Data System (ADS)

Fathy, Adel; Ghamry, Essam

2017-03-01

Though the Equatorial Ionospheric Anomaly (EIA) is represented by two crests within ±15° latitude, a single crest is also observed in the entire ionosphere. Few studies have addressed single crest phenomena. A statistical study of 2237 single crest phenomenon from the in situ electron density measurements of Swarm A satellite was investigated during December 2013-December 2015. Our analysis focused on local time, seasonal, and both geographic and geomagnetic latitudinal variations. Our results show the following observations: 1 - The maximum number of events peaks mainly in the dayside region around 0800-1200 LT and these occur mainly within the magnetic equator. 2 - The maximum amplitude of the single crests take place most prominently during equinoxes. 3 - The majority of single crests occur in the northern hemisphere. 4 - The seasonal distribution of the events shows that the summer events are located further from the magnetic equator in the northern hemisphere and shift their locations into the southern hemisphere in winter, while spring events are centered along the magnetic equator. 5 - Dayside single crest events appear close to the magnetic equator and more centered on the equator in winter season. 6 - Dawn, night and dusk side events reverse their location from northern hemisphere in summer to southern hemisphere in winter.

Annual Conference on Nuclear and Space Radiation Effects, 19th, Las Vegas, NV, July 20-22, 1982, Proceedings

NASA Technical Reports Server (NTRS)

Long, D. M.

1982-01-01

The results of research concerning the effects of nuclear and space radiation are presented. Topics discussed include the basic mechanisms of nuclear and space radiation effects, radiation effects in devices, and radiation effects in microcircuits, including studies of radiation-induced paramagnetic defects in MOS structures, silicon solar cell damage from electrical overstress, radiation-induced charge dynamics in dielectrics, and the enhanced radiation effects on submicron narrow-channel NMOS. Also examined are topics in SGEMP/IEMP phenomena, hardness assurance and testing, energy deposition, desometry, and radiation transport, and single event phenomena. Among others, studies are presented concerning the limits to hardening electronic boxes to IEMP coupling, transient radiation screening of silicon devices using backside laser irradiation, the damage equivalence of electrons, protons, and gamma rays in MOS devices, and the single event upset sensitivity of low power Schottky devices.

Single Event Upset in Static Random Access Memories in Atmospheric Neutron Environments

NASA Astrophysics Data System (ADS)

Arita, Yutaka; Takai, Mikio; Ogawa, Izumi; Kishimoto, Tadafumi

2003-07-01

Single-event upsets (SEUs) in a 0.4 μm 4 Mbit complementary metal oxide semiconductor (CMOS) static random access memory (SRAM) were investigated in various atmospheric neutron environments at sea level, at an altitude of 2612 m mountain, at an altitude of commercial airplane, and at an underground depth of 476 m. Neutron-induced SEUs increase with the increase in altitude. For a device with a borophosphosilicate glass (BPSG) film, SEU rates induced by thermal neutrons increase with the decrease in the cell charge of a memory cell. A thermal neutron-induced SEU is significant in SRAMs with a small cell charge. With the conditions of small cell charge, thermal neutron-induced SEUs account for 60% or more of the total neutron-induced SEUs. The SEU rate induced by atmospheric thermal neutrons can be estimated by an acceleration test using 252Cf.

Added Value of Physical Performance Measures in Predicting Adverse Health-Related Events: Results from the Health, Aging, and Body Composition Study

PubMed Central

Cesari, Matteo; Kritchevsky, Stephen B; Newman, Anne B; Simonsick, Eleanor M; Harris, Tamara B; Penninx, Brenda W; Brach, Jennifer S; Tylavsky, Frances A; Satterfield, Suzanne; Bauer, Doug C; Rubin, Susan M; Visser, Marjolein; Pahor, Marco

2009-01-01

Objectives To determine how three different physical performance measures (PPM) combine for added utility in predicting adverse health events in elders. Design Prospective cohort study. Setting Health, Aging, and Body Composition Study. Participants 3,024 well-functioning older persons (mean age 73.6 years). Measurements Timed gait, repeated chair stands and balance (semi- and full-tandem, and single leg stands each held for 30 seconds) tests were administered at baseline. Usual gait speed was categorized to distinguish high and low risk participants using the previously established 1 m/sec cut-point. The same population-percentile (21.3%) was used to identify cut-points for repeated chair stands (17.05 sec) and balance (53 sec) tests. Cox proportional hazard analyses were performed to evaluate the added value of PPM in predicting mortality, hospitalization, and (severe) mobility limitation events over 6.9 years of follow-up. Results Risk estimates for developing adverse health-related events were similarly large for each of the three high risk groups considered separately. A greater number of PPM scores at the high risk level was associated with a greater risk of developing adverse health-related events. When all three PPMs were considered, having only one poor performance was sufficient to indicate a highly significant higher risk of (severe) lower extremity and mortality events. Conclusion Although gait speed is considered the most important predictor of adverse health events, these findings demonstrate that poor performance on other tests of lower extremity function are equally prognostic. This suggests that chair stand and standing balance performance may be adequate substitutes when gait speed is unavailable. PMID:19207142

RH1020 Single Event Clock Upset Summary Report

NASA Technical Reports Server (NTRS)

Katz, Richard B.; Wang, J. J.

1998-01-01

This report summarizes the testing and analysis of "single event clock upset' in the RH1020. Also included are SEU-rate predictions and design recommendations for risk analysis and reduction. The subject of "upsets" in the RH1020 is best understood by using a model consisting of a global clock buffer and a D-type flip-flop as the basic memory unit. The RH1020 is built on the ACT 1 family architecture. As such, it has one low-skew global clock buffer with a TTL-level input threshold that is accessed via a single dedicated pin. The clock signal is driven to full CMOS levels, buffered, and sent to individual row buffers with one buffer per channel. For low-skew performance, the outputs of all of the RH1020 row buffers are shorted together via metal lines, as is done in the A1020B. All storage in the RH1020 consists of routed flip-flops, constructed with multiplexors and feedback through the routing segments. A simple latch can be constructed from a single (combinatorial or C) module; an edge-triggered flip-flop is constructed using two concatenated latches. There is no storage in the I/O modules. The front end of the clock buffering circuitry, at a common point relative to the row buffer, is a sub-circuit that was determined to be the most susceptible to heavy ions. This is due, in part, to its smaller transistors compared to the rest of the circuitry. This conclusion is also supported by SPICE simulations and an analysis of the heavy ion data, described in this report. The edge triggered D flip-flop has two single-event-upset modes. Mode one, called C-module upset, is caused by a heavy ion striking the C-module's sensitive area on the silicon and produces a soft single bit error at the output of the flip-flop. Mode two, called clock upset, is caused by a heavy ion strike on the clock buffer, generating a runt pulse interpreted as a false clock signal and consequently producing errors at the flip-flop outputs. C-module upset sensitivity in the RH1020 is essentially the same as that of its ACT 1 siblings (A1020, A1020A and A1020B), which were well tested, analyzed, and documented in the literature.

Tropical Pacific Mean State and ENSO Variability across Marine Isotope Stage 3

NASA Astrophysics Data System (ADS)

Hertzberg, J. E.; Schmidt, M. W.; Marcantonio, F.; Bianchi, T. S.

2017-12-01

The El Niño/Southern Oscillation (ENSO) phenomenon is the largest natural interannual signal in the Earth's climate system and has widespread effects on global climate that impact millions of people worldwide. A series of recent research studies predict an increase in the frequency of extreme El Niño and La Niña events as Earth's climate continues to warm. In order for climate scientists to forecast how ENSO will evolve in response to global warming, it is necessary to have accurate, comprehensive records of how the system has naturally changed in the past, especially across past abrupt warming events. Nevertheless, there remains significant uncertainty about past changes in tropical Pacific climate and how ENSO variability relates to the millennial-scale warming events of the last ice age. This study aims to reconstruct changes in the tropical Pacific mean state and ENSO variability across Marine Isotope Stage 3 from a sediment core recovered from the Eastern Equatorial Pacific cold tongue (MV1014-02-17JC, 0°10.8' S, 85°52.0' W, 2846 m water depth). In this region, thermocline temperatures are significantly correlated to ENSO variability - thus, we analyzed Mg/Ca ratios in the thermocline dwelling foraminifera Neogloboquadrina dutertrei as a proxy for thermocline temperatures in the past. Bulk ( 50 tests/sample) foraminifera Mg/Ca temperatures are used to reconstruct long-term variability in the mean state, while single shell ( 1 test/sample, 60 samples) Mg/Ca analyses are used to assess thermocline temperature variance. Based on our refined age model, we find that thermocline temperature increases of up to 3.5°C occur in-step with interstadial warming events recorded in Greenland ice cores. Cooler thermocline temperatures prevail during stadial intervals and Heinrich Events. This suggests that interstadials were more El-Niño like, while stadials and Heinrich Events were more La-Niña like. These temperature changes are compared to new records of dust flux, export productivity, and bottom-water oxygenation measured in the same core. We will also present single shell Mg/Ca results for an interstadial, stadial, and Heinrich Event interval.

The Unconstrained Event Bulletin (UEB) for the IMS Seismic Network Spaning the Period May 15-28, 2010: a New Resource for Algorithm Development and Testing

NASA Astrophysics Data System (ADS)

Brogan, R.; Young, C. J.; Ballard, S.

2017-12-01

A major problem with developing new data processing algorithms for seismic event monitoring is the lack of standard, high-quality "ground-truth" data sets to test against. The unfortunate effect of this is that new algorithms are often developed and tested with new data sets, making comparison of algorithms difficult and subjective. In an effort towards resolving this problem, we have developed the Unconstrained Event Bulletin (UEB), a ground-truth data set from the International Monitoring System (IMS) primary and auxiliary seismic networks for a two-week period in May 2010. All UEB analysis was performed by the same expert, who has more than 30 years of experience analyzing seismic data for nuclear explosion monitoring. We used the most complete International Data Centre (IDC) analyst-review event bulletin (the Late Event Bulletin or LEB) as a starting point for this analysis. To make the UEB more complete, we relaxed the minimum event definite criteria to the level of a pair of P-type and an S-type phases at a single station and using azimuth/slowness as defining. To add even more events that our analyst recognized and didn't want to omit, in rare cases, events were constructed using only 1 P-phase. Perhaps most importantly, on average our analyst spent more than 60 hours per day of data, far more than was possible in the production of the LEB. The result of all this was that while the LEB had 2,101 LEB events for the 2-week time period, we ended up with 11,435 events in the UEB, an increase of over 400%. New events are located all over the world and include both earthquakes and manmade events such as mining explosions. Our intent is to make our UEB data set openly available for all researchers to use for testing detection, correlation, and location algorithms, thus making it much easier to objectively compare different research efforts. Acknowledgement: Sandia National Laboratories is a multi-mission laboratory managed and operated by National Technology and Engineering Solutions of Sandia, LLC., a wholly owned subsidiary of Honeywell International, Inc., for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-NA-0003525.

Remote detection of weak aftershocks of the DPRK underground explosions using waveform cross correlation

NASA Astrophysics Data System (ADS)

Le Bras, R.; Rozhkov, M.; Bobrov, D.; Kitov, I. O.; Sanina, I.

2017-12-01

Association of weak seismic signals generated by low-magnitude aftershocks of the DPRK underground tests into event hypotheses represent a challenge for routine automatic and interactive processing at the International Data Centre (IDC) of the Comprehensive Nuclear-Test-Ban Treaty Organization, due to the relatively low station density of the International Monitoring System (IMS) seismic network. Since 2011, as an alternative, the IDC has been testing various prototype techniques of signal detection and event creation based on waveform cross correlation. Using signals measured by seismic stations of the IMS from DPRK explosions as waveform templates, the IDC detected several small (estimated mb between 2.2 and 3.6) seismic events after two DPRK tests conducted on September 9, 2016 and September 3, 2017. The obtained detections were associated with reliable event hypothesis and then used to locate these events relative to the epicenters of the DPRK explosions. We observe high similarity of the detected signals with the corresponding waveform templates. The newly found signals also correlate well between themselves. In addition, the values of the signal-to-noise ratios (SNR) estimated using the traces of cross correlation coefficients, increase with template length (from 5 s to 150 s), providing strong evidence in favour of their spatial closeness, which allows interpreting them as explosion aftershocks. We estimated the relative magnitudes of all aftershocks using the ratio of RMS amplitudes of the master and slave signal in the cross correlation windows characterized by the highest SNR. Additional waveform data from regional non-IMS stations MDJ and SEHB provide independent validation of these aftershock hypotheses. Since waveform templates from any single master event may be sub-efficient at some stations, we have also developed a method of joint usage of the DPRK and the biggest aftershocks templates to build more robust event hypotheses.

Single Color Multiplexed ddPCR Copy Number Measurements and Single Nucleotide Variant Genotyping.

PubMed

Wood-Bouwens, Christina M; Ji, Hanlee P

2018-01-01

Droplet digital PCR (ddPCR) allows for accurate quantification of genetic events such as copy number variation and single nucleotide variants. Probe-based assays represent the current "gold-standard" for detection and quantification of these genetic events. Here, we introduce a cost-effective single color ddPCR assay that allows for single genome resolution quantification of copy number and single nucleotide variation.

Thoracic injuries to contained and restrained occupants in single-vehicle pure rollover crashes.

PubMed

Bambach, M R; Grzebieta, R H; McIntosh, A S

2013-01-01

Around one in three contained and restrained seriously injured occupants in single-vehicle pure rollover crashes receive a serious injury to the thorax. With dynamic rollover test protocols currently under development, there is a need to understand the nature and cause of serious thoracic injuries incurred in rollover events. This will allow decisions to be made with regards to adoption of a suitable crash test dummy and appropriate thoracic injury criteria in such protocols. Valid rollover occupant protection test protocols will lead to vehicle improvements that will reduce the high trauma burden of vehicle rollover crashes. This paper presents an analysis of contained and restrained occupants involved in single-vehicle pure rollover crashes that occurred in the United States between 2000 and 2009 (inclusive). Serious thoracic injury typology and causality are determined. A logistic regression model is developed to determine associations between the incidence of serious thoracic injury and the human, vehicle and environmental characteristics of the crashes. Recommendations are made with regards to the appropriate assessment of potential thoracic injury in dynamic rollover occupant protection crash test protocols. Copyright © 2012 Elsevier Ltd. All rights reserved.

Radiation Testing, Characterization and Qualification Challenges for Modern Microelectronics and Photonics Devices and Technologies

NASA Technical Reports Server (NTRS)

LaBel, Kenneth A.; Cohn, Lewis M.

2008-01-01

At GOMAC 2007, we discussed a selection of the challenges for radiation testing of modern semiconductor devices focusing on state-of-the-art memory technologies. This included FLASH non-volatile memories (NVMs) and synchronous dynamic random access memories (SDRAMs). In this presentation, we extend this discussion in device packaging and complexity as well as single event upset (SEU) mechanisms using several technology areas as examples including: system-on-a-chip (SOC) devices and photonic or fiber optic systems. The underlying goal is intended to provoke thought for understanding the limitations and interpretation of radiation testing results.

Resolving Single Molecule Lysozyme Dynamics with a Carbon Nanotube Electronic Circuit

NASA Astrophysics Data System (ADS)

Choi, Yongki; Moody, Issa S.; Perez, Israel; Sheps, Tatyana; Weiss, Gregory A.; Collins, Philip G.

2011-03-01

High resolution, real-time monitoring of a single lysozyme molecule is demonstrated by fabricating nanoscale electronic devices based on single-walled carbon nanotubes (SWCNT). In this sensor platform, a biomolecule of interest is attached to a single SWCNT device. The electrical conductance transduces chemical events with single molecule sensitivity and 10 microsecond resolution. In this work, enzymatic turnover by lysozyme is investigated, because the mechanistic details for its processivity and dynamics remain incompletely understood. Stochastically distributed binding events between a lysozyme and its binding substrate, peptidoglycan, are monitored via the sensor conductance. Furthermore, the magnitude and repetition rate of these events varies with pH and the presence of inhibitors or denaturation agents. Changes in the conductance signal are analyzed in terms of lysozyme's internal hinge motion, binding events, and enzymatic processing.

Field Programmable Gate Aray (FPGA) Radiation Data: All Data is Not Equal

NASA Technical Reports Server (NTRS)

Label, Kenneth A.; Berg, Melanie D.

2016-01-01

Electronic parts (integrated circuits) have grown in complexity such that determining all failure modes and risks based on single particle event radiation testing is impossible. In this presentation, the authors will present why this is so and provide some realism on what this means to FPGAs. Its all about understanding actual risks and not making assumptions.

1990 IEEE Annual Conference on Nuclear and Space Radiation Effects, 27th, Reno, NV, July 16-20, 1990, Proceedings

NASA Technical Reports Server (NTRS)

Fleetwood, Daniel M. (Editor)

1990-01-01

Various papers on nuclear and space radiation effects are presented. The general topics addressed include: basic mechanisms of radiation effects, dosimetry and energy-dependent effects, hardness assurance and testing techniques, single-event upset and latchup, isolation technologies, device and integrated circuit effects and hardening, spacecraft charging and electromagnetic effects.

The impact of heat on mortality and morbidity in the Greater Metropolitan Sydney Region: a case crossover analysis.

PubMed

Wilson, Leigh Ann; Morgan, Geoffrey Gerard; Hanigan, Ivan Charles; Johnston, Fay H; Abu-Rayya, Hisham; Broome, Richard; Gaskin, Clive; Jalaludin, Bin

2013-11-15

This study examined the association between unusually high temperature and daily mortality (1997-2007) and hospital admissions (1997-2010) in the Sydney Greater Metropolitan Region (GMR) to assist in the development of targeted health programs designed to minimise the public health impact of extreme heat. Sydney GMR was categorized into five climate zones. Heat-events were defined as severe or extreme. Using a time-stratified case-crossover design with a conditional logistic regression model we adjusted for influenza epidemics, public holidays, and climate zone. Odds ratios (OR) and 95% confidence intervals were estimated for associations between daily mortality and hospital admissions with heat-event days compared to non-heat event days for single and three day heat-events. All-cause mortality overall had similar magnitude associations with single day and three day extreme and severe events as did all cardiovascular mortality. Respiratory mortality was associated with single day and three day severe events (95th percentile, lag0: OR = 1.14; 95%CI: 1.04 to 1.24). Diabetes mortality had similar magnitude associations with single day and three day severe events (95th percentile, lag0: OR = 1.22; 95%CI: 1.03 to 1.46) but was not associated with extreme events. Hospital admissions for heat related injuries, dehydration, and other fluid disorders were associated with single day and three day extreme and severe events. Contrary to our findings for mortality, we found inconsistent and sometimes inverse associations for extreme and severe events with cardiovascular disease and respiratory disease hospital admissions. Controlling for air pollutants did not influence the mortality associations but reduced the magnitude of the associations with hospital admissions particularly for ozone and respiratory disease. Single and three day events of unusually high temperatures in Sydney are associated with similar magnitude increases in mortality and hospital admissions. The trend towards an inverse association between cardio-vascular admissions and heat-events and the strong positive association between cardio-vascular mortality and heat-events suggests these events may lead to a rapid deterioration in persons with existing cardio-vascular disease resulting in death. To reduce the adverse effects of high temperatures over multiple days, and less extreme but more frequent temperatures over single days, targeted public health messages are critical.

The impact of heat on mortality and morbidity in the Greater Metropolitan Sydney Region: a case crossover analysis

PubMed Central

2013-01-01

Background This study examined the association between unusually high temperature and daily mortality (1997–2007) and hospital admissions (1997–2010) in the Sydney Greater Metropolitan Region (GMR) to assist in the development of targeted health programs designed to minimise the public health impact of extreme heat. Methods Sydney GMR was categorized into five climate zones. Heat-events were defined as severe or extreme. Using a time-stratified case-crossover design with a conditional logistic regression model we adjusted for influenza epidemics, public holidays, and climate zone. Odds ratios (OR) and 95% confidence intervals were estimated for associations between daily mortality and hospital admissions with heat-event days compared to non-heat event days for single and three day heat-events. Results All-cause mortality overall had similar magnitude associations with single day and three day extreme and severe events as did all cardiovascular mortality. Respiratory mortality was associated with single day and three day severe events (95thpercentile, lag0: OR = 1.14; 95%CI: 1.04 to 1.24). Diabetes mortality had similar magnitude associations with single day and three day severe events (95thpercentile, lag0: OR = 1.22; 95%CI: 1.03 to 1.46) but was not associated with extreme events. Hospital admissions for heat related injuries, dehydration, and other fluid disorders were associated with single day and three day extreme and severe events. Contrary to our findings for mortality, we found inconsistent and sometimes inverse associations for extreme and severe events with cardiovascular disease and respiratory disease hospital admissions. Controlling for air pollutants did not influence the mortality associations but reduced the magnitude of the associations with hospital admissions particularly for ozone and respiratory disease. Conclusions Single and three day events of unusually high temperatures in Sydney are associated with similar magnitude increases in mortality and hospital admissions. The trend towards an inverse association between cardio-vascular admissions and heat-events and the strong positive association between cardio-vascular mortality and heat-events suggests these events may lead to a rapid deterioration in persons with existing cardio-vascular disease resulting in death. To reduce the adverse effects of high temperatures over multiple days, and less extreme but more frequent temperatures over single days, targeted public health messages are critical. PMID:24238064

Developing and Testing the Health Care Safety Hotline: A Prototype Consumer Reporting System for Patient Safety Events.

PubMed

Schneider, Eric C; Ridgely, M Susan; Quigley, Denise D; Hunter, Lauren E; Leuschner, Kristin J; Weingart, Saul N; Weissman, Joel S; Zimmer, Karen P; Giannini, Robert C

2017-06-01

This article describes the design, development, and testing of the Health Care Safety Hotline, a prototype consumer reporting system for patient safety events. The prototype was designed and developed with ongoing review by a technical expert panel and feedback obtained during a public comment period. Two health care delivery organizations in one metropolitan area collaborated with the researchers to demonstrate and evaluate the system. The prototype was deployed and elicited information from patients, family members, and caregivers through a website or an 800 phone number. The reports were considered useful and had little overlap with information received by the health care organizations through their usual risk management, customer service, and patient safety monitoring systems. However, the frequency of reporting was lower than anticipated, suggesting that further refinements, including efforts to raise awareness by actively soliciting reports from subjects, might be necessary to substantially increase the volume of useful reports. It is possible that a single technology platform could be built to meet a variety of different patient safety objectives, but it may not be possible to achieve several objectives simultaneously through a single consumer reporting system while also establishing trust with patients, caregivers, and providers.

Analysis of SEL on Commercial SRAM Memories and Mixed-Field Characterization of a Latchup Detection Circuit for LEO Space Applications

NASA Astrophysics Data System (ADS)

Secondo, R.; Alía, R. Garcia; Peronnard, P.; Brugger, M.; Masi, A.; Danzeca, S.; Merlenghi, A.; Vaillé, J.-R.; Dusseau, L.

2017-08-01

A single event latchup (SEL) experiment based on commercial static random access memory (SRAM) memories has recently been proposed in the framework of the European Organization for Nuclear Research (CERN) Latchup Experiment and Student Satellite nanosatellite low Earth orbit (LEO) space mission. SEL characterization of three commercial SRAM memories has been carried out at the Paul Scherrer Institut (PSI) facility, using monoenergetic focused proton beams and different acquisition setups. The best target candidate was selected and a circuit for SEL detection has been proposed and tested at CERN, in the CERN High Energy AcceleRator Mixed-field facility (CHARM). Experimental results were carried out at test locations representative of the LEO environment, thus providing a full characterization of the SRAM cross sections, together with the analysis of the single-event effect and total ionizing dose of the latchup detection circuit in relation to the particle spectra expected during mission. The setups used for SEL monitoring are described, and details of the proposed circuit components and topology are presented. Experimental results obtained both at PSI and at CHARM facilities are discussed.

The Influence of Age at Single-Event Multilevel Surgery on Outcome in Children with Cerebral Palsy Who Walk with Flexed Knee Gait

ERIC Educational Resources Information Center

Svehlik, Martin; Steinwender, Gerhard; Kraus, Tanja; Saraph, Vinay; Lehmann, Thomas; Linhart, Wolfgang E.; Zwick, Ernst B.

2011-01-01

Aim: Information on the timing and long-term outcome of single-event multilevel surgery in children with bilateral spastic cerebral palsy (CP) walking with flexed knee gait is limited. Based on our clinical experience, we hypothesized that older children with bilateral spastic CP would benefit more from single-event multilevel surgery than younger…

Grand average ERP-image plotting and statistics: A method for comparing variability in event-related single-trial EEG activities across subjects and conditions

PubMed Central

Delorme, Arnaud; Miyakoshi, Makoto; Jung, Tzyy-Ping; Makeig, Scott

2014-01-01

With the advent of modern computing methods, modeling trial-to-trial variability in biophysical recordings including electroencephalography (EEG) has become of increasingly interest. Yet no widely used method exists for comparing variability in ordered collections of single-trial data epochs across conditions and subjects. We have developed a method based on an ERP-image visualization tool in which potential, spectral power, or some other measure at each time point in a set of event-related single-trial data epochs are represented as color coded horizontal lines that are then stacked to form a 2-D colored image. Moving-window smoothing across trial epochs can make otherwise hidden event-related features in the data more perceptible. Stacking trials in different orders, for example ordered by subject reaction time, by context-related information such as inter-stimulus interval, or some other characteristic of the data (e.g., latency-window mean power or phase of some EEG source) can reveal aspects of the multifold complexities of trial-to-trial EEG data variability. This study demonstrates new methods for computing and visualizing grand ERP-image plots across subjects and for performing robust statistical testing on the resulting images. These methods have been implemented and made freely available in the EEGLAB signal-processing environment that we maintain and distribute. PMID:25447029

Single event effect hardness for the front-end ASICs in the DAMPE satellite BGO calorimeter

NASA Astrophysics Data System (ADS)

Gao, Shan-Shan; Jiang, Di; Feng, Chang-Qing; Xi, Kai; Liu, Shu-Bin; An, Qi

2016-01-01

The Dark Matter Particle Explorer (DAMPE) is a Chinese scientific satellite designed for cosmic ray studies with a primary scientific goal of indirect detection of dark matter particles. As a crucial sub-detector, the BGO calorimeter measures the energy spectrum of cosmic rays in the energy range from 5 GeV to 10 TeV. In order to implement high-density front-end electronics (FEE) with the ability to measure 1848 signals from 616 photomultiplier tubes on the strictly constrained satellite platform, two kinds of 32-channel front-end ASICs, VA160 and VATA160, are customized. However, a space mission period of more than 3 years makes single event effects (SEEs) become threats to reliability. In order to evaluate SEE sensitivities of these chips and verify the effectiveness of mitigation methods, a series of laser-induced and heavy ion-induced SEE tests were performed. Benefiting from the single event latch-up (SEL) protection circuit for power supply, the triple module redundancy (TMR) technology for the configuration registers and the optimized sequential design for the data acquisition process, 52 VA160 chips and 32 VATA160 chips have been applied in the flight model of the BGO calorimeter with radiation hardness assurance. Supported by Strategic Priority Research Program on Space Science of the Chinese Academy of Sciences (XDA04040202-4) and Fundamental Research Funds for the Central Universities (WK2030040048)

Catastrophic ice lake collapse in Aram Chaos, Mars

NASA Astrophysics Data System (ADS)

Roda, Manuel; Kleinhans, Maarten G.; Zegers, Tanja E.; Oosthoek, Jelmer H. P.

2014-07-01

Hesperian chaotic terrains have been recognized as the source of outflow channels formed by catastrophic outflows. Four main scenarios have been proposed for the formation of chaotic terrains that involve different amounts of water and single or multiple outflow events. Here, we test these scenarios with morphological and structural analyses of imagery and elevation data for Aram Chaos in conjunction with numerical modeling of the morphological evolution of the catastrophic carving of the outflow valley. The morphological and geological analyses of Aram Chaos suggest large-scale collapse and subsidence (1500 m) of the entire area, which is consistent with a massive expulsion of liquid water from the subsurface in one single event. The combined observations suggest a complex process starting with the outflow of water from two small channels, followed by continuous groundwater sapping and headward erosion and ending with a catastrophic lake rim collapse and carving of the Aram Valley, which is synchronous with the 2.5 Ga stage of the Ares Vallis formation. The water volume and formative time scale required to carve the Aram channels indicate that a single, rapid (maximum tens of days) and catastrophic (flood volume of 9.3 × 104 km3) event carved the outflow channel. We conclude that a sub-ice lake collapse model can best explain the features of the Aram Chaos Valley system as well as the time scale required for its formation.

Simulations of Cloud-Radiation Interaction Using Large-Scale Forcing Derived from the CINDY/DYNAMO Northern Sounding Array

NASA Technical Reports Server (NTRS)

Wang, Shuguang; Sobel, Adam H.; Fridlind, Ann; Feng, Zhe; Comstock, Jennifer M.; Minnis, Patrick; Nordeen, Michele L.

2015-01-01

The recently completed CINDY/DYNAMO field campaign observed two Madden-Julian oscillation (MJO) events in the equatorial Indian Ocean from October to December 2011. Prior work has indicated that the moist static energy anomalies in these events grew and were sustained to a significant extent by radiative feedbacks. We present here a study of radiative fluxes and clouds in a set of cloud-resolving simulations of these MJO events. The simulations are driven by the large-scale forcing data set derived from the DYNAMO northern sounding array observations, and carried out in a doubly periodic domain using the Weather Research and Forecasting (WRF) model. Simulated cloud properties and radiative fluxes are compared to those derived from the S-PolKa radar and satellite observations. To accommodate the uncertainty in simulated cloud microphysics, a number of single-moment (1M) and double-moment (2M) microphysical schemes in the WRF model are tested. The 1M schemes tend to underestimate radiative flux anomalies in the active phases of the MJO events, while the 2M schemes perform better, but can overestimate radiative flux anomalies. All the tested microphysics schemes exhibit biases in the shapes of the histograms of radiative fluxes and radar reflectivity. Histograms of radiative fluxes and brightness temperature indicate that radiative biases are not evenly distributed; the most significant bias occurs in rainy areas with OLR less than 150 W/ cu sq in the 2M schemes. Analysis of simulated radar reflectivities indicates that this radiative flux uncertainty is closely related to the simulated stratiform cloud coverage. Single-moment schemes underestimate stratiform cloudiness by a factor of 2, whereas 2M schemes simulate much more stratiform cloud.

Vasodilator Stress Single-Photon Emission Computed Tomography or Contrast Stress Echocardiography Association with Hard Cardiac Events in Suspected Coronary Artery Disease.

PubMed

Gaibazzi, Nicola; Siniscalchi, Carmine; Porter, Thomas R; Crocamo, Antonio; Basaglia, Manuela; Boffetti, Francesca; Lorenzoni, Valentina

2018-06-01

We compared the long-term outcome of subjects without prior cardiac disease who underwent either vasodilator single-photon emission computed tomography (SPECT) or contrast stress-echocardiography (cSE) for suspected coronary artery disease (CAD). Subjects who underwent vasodilator SPECT or cSE between 2008 and 2012 for suspected CAD but no history of cardiac disease were included. We retrospectively compared the association of each method with combined all-cause death and nonfatal myocardial infarction and their positive predictive value (PPV) for angiographically obstructive CAD. A total of 1,387 subjects were selected: 497 who underwent SPECT and 890 who underwent cSE. During 4 years of mean follow-up there were 78 hard events in the cSE group and 51 in the SPECT group. Event-free survival in subjects testing positive for ischemia, either with SPECT or cSE, was significantly worse both in the overall population and after propensity matching patients. In multivariable analyses, vasodilator SPECT or cSE demonstrated significant stratification capability with an ischemic test doubling (SPECT) or more than doubling (cSE) the risk of future hard events independently from other variables. PPV of vasodilator SPECT for the diagnosis of obstructive CAD was inferior to vasodilator cSE (PPV = 63% vs 89%, respectively; P < .001). Our study suggests that the associations of vasodilator SPECT or cSE with outcome are comparable, with cSE demonstrating better diagnostic PPV for CAD. The absence of ionizing radiation and anticipated lower costs from higher PPV suggest that vasodilator cSE is a valid alternative to vasodilator SPECT as a gatekeeper in subjects without a prior history of CAD. Copyright © 2018 American Society of Echocardiography. Published by Elsevier Inc. All rights reserved.

FPGA Online Tracking Algorithm for the PANDA Straw Tube Tracker

NASA Astrophysics Data System (ADS)

Liang, Yutie; Ye, Hua; Galuska, Martin J.; Gessler, Thomas; Kuhn, Wolfgang; Lange, Jens Soren; Wagner, Milan N.; Liu, Zhen'an; Zhao, Jingzhou

2017-06-01

A novel FPGA based online tracking algorithm for helix track reconstruction in a solenoidal field, developed for the PANDA spectrometer, is described. Employing the Straw Tube Tracker detector with 4636 straw tubes, the algorithm includes a complex track finder, and a track fitter. Implemented in VHDL, the algorithm is tested on a Xilinx Virtex-4 FX60 FPGA chip with different types of events, at different event rates. A processing time of 7 $\\mu$s per event for an average of 6 charged tracks is obtained. The momentum resolution is about 3\\% (4\\%) for $p_t$ ($p_z$) at 1 GeV/c. Comparing to the algorithm running on a CPU chip (single core Intel Xeon E5520 at 2.26 GHz), an improvement of 3 orders of magnitude in processing time is obtained. The algorithm can handle severe overlapping of events which are typical for interaction rates above 10 MHz.

Longitudinal associations between post-traumatic distress and depressive symptoms following a traumatic event: a test of three models.

PubMed

Schindel-Allon, I; Aderka, I M; Shahar, G; Stein, M; Gilboa-Schechtman, E

2010-10-01

Symptoms of post-traumatic stress disorder (PTSD) and depression are highly co-morbid following a traumatic event. Nevertheless, decisive evidence regarding the direction of the relationship between these clinical entities is missing. The aim of the present study was to examine the nature of this relationship by comparing a synchronous change model (PTSD and depression are time synchronous, possibly stemming from a third common factor) with a demoralization model (i.e. PTSD symptoms causing depression) and a depressogenic model (i.e. depressive symptoms causing PTSD symptoms). Israeli adult victims of single-event traumas (n=156) were assessed on measures of PTSD and depression at 2, 4 and 12 weeks post-event. A cross-lagged structural equation modeling (SEM) analysis provided results consistent with the synchronous change model and the depressogenic model. Depressive symptoms may play an important role in the development of post-traumatic symptoms.

Entropy Based Genetic Association Tests and Gene-Gene Interaction Tests

PubMed Central

de Andrade, Mariza; Wang, Xin

2011-01-01

In the past few years, several entropy-based tests have been proposed for testing either single SNP association or gene-gene interaction. These tests are mainly based on Shannon entropy and have higher statistical power when compared to standard χ2 tests. In this paper, we extend some of these tests using a more generalized entropy definition, Rényi entropy, where Shannon entropy is a special case of order 1. The order λ (>0) of Rényi entropy weights the events (genotype/haplotype) according to their probabilities (frequencies). Higher λ places more emphasis on higher probability events while smaller λ (close to 0) tends to assign weights more equally. Thus, by properly choosing the λ, one can potentially increase the power of the tests or the p-value level of significance. We conducted simulation as well as real data analyses to assess the impact of the order λ and the performance of these generalized tests. The results showed that for dominant model the order 2 test was more powerful and for multiplicative model the order 1 or 2 had similar power. The analyses indicate that the choice of λ depends on the underlying genetic model and Shannon entropy is not necessarily the most powerful entropy measure for constructing genetic association or interaction tests. PMID:23089811

Event-Based Stereo Depth Estimation Using Belief Propagation.

PubMed

Xie, Zhen; Chen, Shengyong; Orchard, Garrick

2017-01-01

Compared to standard frame-based cameras, biologically-inspired event-based sensors capture visual information with low latency and minimal redundancy. These event-based sensors are also far less prone to motion blur than traditional cameras, and still operate effectively in high dynamic range scenes. However, classical framed-based algorithms are not typically suitable for these event-based data and new processing algorithms are required. This paper focuses on the problem of depth estimation from a stereo pair of event-based sensors. A fully event-based stereo depth estimation algorithm which relies on message passing is proposed. The algorithm not only considers the properties of a single event but also uses a Markov Random Field (MRF) to consider the constraints between the nearby events, such as disparity uniqueness and depth continuity. The method is tested on five different scenes and compared to other state-of-art event-based stereo matching methods. The results show that the method detects more stereo matches than other methods, with each match having a higher accuracy. The method can operate in an event-driven manner where depths are reported for individual events as they are received, or the network can be queried at any time to generate a sparse depth frame which represents the current state of the network.

Variation in esophageal physiology testing in clinical practice: Results from an international survey.

PubMed

Sweis, R; Heinrich, H; Fox, M

2018-03-01

Advances in clinical measurement of esophageal motility and function have improved the assessment of swallowing disorders and reflux symptoms. Variation in data acquisition, analysis, and reporting exists and impacts on diagnosis and management. This study examined variation in esophageal manometry methodology between institutions to establish the status in current practice. A structured survey was distributed through international NGM societies using an Internet-based platform. Questions explored infrastructure, technology, analysis, and reporting. Responses were received from 91 centers from 29 countries. Eighteen (20%) centers used "conventional" manometry, 75 (82%) high-resolution manometry, and 53 (58%) HR impedance manometry. All centers documented motility for single water swallows. The Chicago Classification was applied by 65 (71.4%) centers. In contrast, analysis of EGJ morphology varied widely. Adjunctive testing was often applied: multiple rapid swallows (77%), rapid drink challenge (77%), single solid swallows (63%), and a standard test meal (18%). Of 86 (94.5%) units that offered pH impedance (pH-Z) studies, approximately half (53.5%) performed tests on acid-suppressant medication in patients with a high pretest probability (eg, erosive esophagitis). Most (75.6%) centers manually reviewed every reflux event. Others examined pH-Z data only prior to symptoms. To assess symptom association with reflux events, 73.6% centers analyzed each symptom separately, whereas 29.7% centers pooled symptoms. There is marked variation in the data acquisition, analysis, and reporting of esophageal manometry studies. Further efforts to improve quality and uniformity in testing and reporting are required. This survey provides information upon which best-practice guidelines can be developed. © 2017 John Wiley & Sons Ltd.

Assessment of lnternational Space Station (ISS) Lithium-ion Battery Thermal Runaway (TR)

NASA Technical Reports Server (NTRS)

Graika, Jason

2017-01-01

This task was developed in the wake of the Boeing 787 Dreamliner lithium-ion battery TR incidents of January 2013 and January 2014. The Electrical Power Technical Discipline Team supported the Dreamliner investigations and has followed up by applying lessons learned to conduct an introspective evaluation of NASA's risk of similar incidents in its own lithium-ion battery deployments. This activity has demonstrated that historically NASA, like Boeing and others in the aerospace industry, has emphasized the prevention of TR in a single cell within the battery (e.g., cell screening) but has not considered TR severity-reducing measures in the event of a single-cell TR event. center dotIn the recent update of the battery safety standard (JSC 20793) to address this paradigm shift, the NASA community included requirements for assessing TR severity and identifying simple, low-cost severity reduction measures. This task will serve as a pathfinder for meeting those requirements and will specifically look at a number of different lithium-ion batteries currently in the design pipeline within the ISS Program batteries that, should they fail in a Dreamliner-like incident, could result in catastrophic consequences. This test is an abuse test to understand the heat transfer properties of the cell and ORU in thermal runaway, with radiant barriers in place in a flight like test in on orbit conditions. This includes studying the heat flow and distribution in the ORU. This data will be used to validate the thermal runaway analysis. This test does not cover the ambient pressure case. center dotThere is no pass/ fail criteria for this test.

pH and rate of ‘dark’ events in toad retinal rods: test of a hypothesis on the molecular origin of photoreceptor noise

PubMed Central

Firsov, Mikhail L; Donner, Kristian; Govardovskii, Victor I

2002-01-01

Thermal activation of the visual pigment constitutes a fundamental constraint on visual sensitivity. Its electrical correlate in the membrane current of dark-adapted rods are randomly occurring discrete ‘dark events’ indistinguishable from responses to single photons. It has been proposed that thermal activation occurs in a small subpopulation of rhodopsin molecules where the Schiff base linking the chromophore to the protein part is unprotonated. On this hypothesis, rates of thermal activation should increase strongly with rising pH. The hypothesis has been tested by measuring the effect of pH changes on the frequency of discrete dark events in red rods of the common toad Bufo bufo. Dark noise was recorded from isolated rods using the suction pipette technique. Changes in cytoplasmic pH upon manipulations of extracellular pH were quantified by measuring, using fast single-cell microspectrophotometry, the pH-dependent metarhodopsin I-metarhodopsin II equilibrium and subsequent metarhodopsin III formation. These measurements show that, in the conditions of the electrophysiological experiments, changing perfusion pH from 6.5 to 9.3 resulted in a cytoplasmic pH shift from 7.6 to 8.5 that was readily sensed by the rhodopsin. This shift, which implies an 8-fold decrease in cytoplasmic [H+], did not increase the rate of dark events. The results contradict the hypothesis that thermal pigment activation depends on prior deprotonation of the Schiff base. PMID:11897853

Subdecoherence time generation and detection of orbital entanglement in quantum dots.

PubMed

Brange, F; Malkoc, O; Samuelsson, P

2015-05-01

Recent experiments have demonstrated subdecoherence time control of individual single-electron orbital qubits. Here we propose a quantum-dot-based scheme for generation and detection of pairs of orbitally entangled electrons on a time scale much shorter than the decoherence time. The electrons are entangled, via two-particle interference, and transferred to the detectors during a single cotunneling event, making the scheme insensitive to charge noise. For sufficiently long detector dot lifetimes, cross-correlation detection of the dot charges can be performed with real-time counting techniques, providing for an unambiguous short-time Bell inequality test of orbital entanglement.

Updated Electronic Testbed System

NASA Technical Reports Server (NTRS)

Brewer, Kevin L.

2001-01-01

As we continue to advance in exploring space frontiers, technology must also advance. The need for faster data recovery and data processing is crucial. In this, the less equipment used, and lighter that equipment is, the better. Because integrated circuits become more sensitive in high altitude, experimental verification and quantification is required. The Center for Applied Radiation Research (CARR) at Prairie View A&M University was awarded a grant by NASA to participate in the NASA ER-2 Flight Program, the APEX balloon flight program, and the Student Launch Program. These programs are to test anomalous errors in integrated circuits due to single event effects (SEE). CARR had already begun experiments characterizing the SEE behavior of high speed and high density SRAM's. The research center built a error testing system using a PC-104 computer unit, an Iomega Zip drive for storage, a test board with the components under test, and a latchup detection and reset unit. A test program was written to continuously monitor a stored data pattern in the SRAM chip and record errors. The devices under test were eight 4Mbit memory chips totaling 4Mbytes of memory. CARR was successful at obtaining data using the Electronic TestBed System (EBS) in various NASA ER-2 test flights. These series of high altitude flights of up to 70,000 feet, were effective at yielding the conditions which single event effects usually occur. However, the data received from the series of flights indicated one error per twenty-four hours. Because flight test time is very expensive, the initial design proved not to be cost effective. The need for orders of magnitude with more memory became essential. Therefore, a project which could test more memory within a given time was created. The goal of this project was not only to test more memory within a given time, but also to have a system with a faster processing speed, and which used less peripherals. This paper will describe procedures used to build an updated Electronic Testbed System.

Joint Models of Longitudinal and Time-to-Event Data with More Than One Event Time Outcome: A Review.

PubMed

Hickey, Graeme L; Philipson, Pete; Jorgensen, Andrea; Kolamunnage-Dona, Ruwanthi

2018-01-31

Methodological development and clinical application of joint models of longitudinal and time-to-event outcomes have grown substantially over the past two decades. However, much of this research has concentrated on a single longitudinal outcome and a single event time outcome. In clinical and public health research, patients who are followed up over time may often experience multiple, recurrent, or a succession of clinical events. Models that utilise such multivariate event time outcomes are quite valuable in clinical decision-making. We comprehensively review the literature for implementation of joint models involving more than a single event time per subject. We consider the distributional and modelling assumptions, including the association structure, estimation approaches, software implementations, and clinical applications. Research into this area is proving highly promising, but to-date remains in its infancy.

Method and apparatus for single-stepping coherence events in a multiprocessor system under software control

DOEpatents

Blumrich, Matthias A.; Salapura, Valentina

2010-11-02

An apparatus and method are disclosed for single-stepping coherence events in a multiprocessor system under software control in order to monitor the behavior of a memory coherence mechanism. Single-stepping coherence events in a multiprocessor system is made possible by adding one or more step registers. By accessing these step registers, one or more coherence requests are processed by the multiprocessor system. The step registers determine if the snoop unit will operate by proceeding in a normal execution mode, or operate in a single-step mode.

The promise of discovering population-specific disease-associated genes in South Asia.

PubMed

Nakatsuka, Nathan; Moorjani, Priya; Rai, Niraj; Sarkar, Biswanath; Tandon, Arti; Patterson, Nick; Bhavani, Gandham SriLakshmi; Girisha, Katta Mohan; Mustak, Mohammed S; Srinivasan, Sudha; Kaushik, Amit; Vahab, Saadi Abdul; Jagadeesh, Sujatha M; Satyamoorthy, Kapaettu; Singh, Lalji; Reich, David; Thangaraj, Kumarasamy

2017-09-01

The more than 1.5 billion people who live in South Asia are correctly viewed not as a single large population but as many small endogamous groups. We assembled genome-wide data from over 2,800 individuals from over 260 distinct South Asian groups. We identified 81 unique groups, 14 of which had estimated census sizes of more than 1 million, that descend from founder events more extreme than those in Ashkenazi Jews and Finns, both of which have high rates of recessive disease due to founder events. We identified multiple examples of recessive diseases in South Asia that are the result of such founder events. This study highlights an underappreciated opportunity for decreasing disease burden among South Asians through discovery of and testing for recessive disease-associated genes.

The past and the future of Alzheimer's disease CSF biomarkers-a journey toward validated biochemical tests covering the whole spectrum of molecular events.

PubMed

Blennow, Kaj; Zetterberg, Henrik

2015-01-01

This paper gives a short review on cerebrospinal fluid (CSF) biomarkers for Alzheimer's disease (AD), from early developments to high-precision validated assays on fully automated lab analyzers. We also discuss developments on novel biomarkers, such as synaptic proteins and Aβ oligomers. Our vision for the future is that assaying a set of biomarkers in a single CSF tube can monitor the whole spectrum of AD molecular pathogenic events. CSF biomarkers will have a central position not only for clinical diagnosis, but also for the understanding of the sequence of molecular events in the pathogenic process underlying AD and as tools to monitor the effects of novel drug candidates targeting these different mechanisms.

The promise of disease gene discovery in South Asia

PubMed Central

Nakatsuka, Nathan; Moorjani, Priya; Rai, Niraj; Sarkar, Biswanath; Tandon, Arti; Patterson, Nick; Bhavani, Gandham SriLakshmi; Girisha, Katta Mohan; Mustak, Mohammed S; Srinivasan, Sudha; Kaushik, Amit; Vahab, Saadi Abdul; Jagadeesh, Sujatha M.; Satyamoorthy, Kapaettu; Singh, Lalji; Reich, David; Thangaraj, Kumarasamy

2017-01-01

The more than 1.5 billion people who live in South Asia are correctly viewed not as a single large population, but as many small endogamous groups. We assembled genome-wide data from over 2,800 individuals from over 260 distinct South Asian groups. We identify 81 unique groups, of which 14 have estimated census sizes of more than a million, that descend from founder events more extreme than those in Ashkenazi Jews and Finns, both of which have high rates of recessive disease due to founder events. We identify multiple examples of recessive diseases in South Asia that are the result of such founder events. This study highlights an under-appreciated opportunity for reducing disease burden among South Asians through the discovery of and testing for recessive disease genes. PMID:28714977

A Tool for Low Noise Procedures Design and Community Noise Impact Assessment: The Rotorcraft Noise Model (RNM)

NASA Technical Reports Server (NTRS)

Conner, David A.; Page, Juliet A.

2002-01-01

To improve aircraft noise impact modeling capabilities and to provide a tool to aid in the development of low noise terminal area operations for rotorcraft and tiltrotors, the Rotorcraft Noise Model (RNM) was developed by the NASA Langley Research Center and Wyle Laboratories. RNM is a simulation program that predicts how sound will propagate through the atmosphere and accumulate at receiver locations located on flat ground or varying terrain, for single and multiple vehicle flight operations. At the core of RNM are the vehicle noise sources, input as sound hemispheres. As the vehicle "flies" along its prescribed flight trajectory, the source sound propagation is simulated and accumulated at the receiver locations (single points of interest or multiple grid points) in a systematic time-based manner. These sound signals at the receiver locations may then be analyzed to obtain single event footprints, integrated noise contours, time histories, or numerous other features. RNM may also be used to generate spectral time history data over a ground mesh for the creation of single event sound animation videos. Acoustic properties of the noise source(s) are defined in terms of sound hemispheres that may be obtained from theoretical predictions, wind tunnel experimental results, flight test measurements, or a combination of the three. The sound hemispheres may contain broadband data (source levels as a function of one-third octave band) and pure-tone data (in the form of specific frequency sound pressure levels and phase). A PC executable version of RNM is publicly available and has been adopted by a number of organizations for Environmental Impact Assessment studies of rotorcraft noise. This paper provides a review of the required input data, the theoretical framework of RNM's propagation model and the output results. Code validation results are provided from a NATO helicopter noise flight test as well as a tiltrotor flight test program that used the RNM as a tool to aid in the development of low noise approach profiles.

Are the Stress Drops of Small Earthquakes Good Predictors of the Stress Drops of Larger Earthquakes?

NASA Astrophysics Data System (ADS)

Hardebeck, J.

2017-12-01

Uncertainty in PSHA could be reduced through better estimates of stress drop for possible future large earthquakes. Studies of small earthquakes find spatial variability in stress drop; if large earthquakes have similar spatial patterns, their stress drops may be better predicted using the stress drops of small local events. This regionalization implies the variance with respect to the local mean stress drop may be smaller than the variance with respect to the global mean. I test this idea using the Shearer et al. (2006) stress drop catalog for M1.5-3.1 events in southern California. I apply quality control (Hauksson, 2015) and remove near-field aftershocks (Wooddell & Abrahamson, 2014). The standard deviation of the distribution of the log10 stress drop is reduced from 0.45 (factor of 3) to 0.31 (factor of 2) by normalizing each event's stress drop by the local mean. I explore whether a similar variance reduction is possible when using the Shearer catalog to predict stress drops of larger southern California events. For catalogs of moderate-sized events (e.g. Kanamori, 1993; Mayeda & Walter, 1996; Boyd, 2017), normalizing by the Shearer catalog's local mean stress drop does not reduce the standard deviation compared to the unmodified stress drops. I compile stress drops of larger events from the literature, and identify 15 M5.5-7.5 earthquakes with at least three estimates. Because of the wide range of stress drop estimates for each event, and the different techniques and assumptions, it is difficult to assign a single stress drop value to each event. Instead, I compare the distributions of stress drop estimates for pairs of events, and test whether the means of the distributions are statistically significantly different. The events divide into 3 categories: low, medium, and high stress drop, with significant differences in mean stress drop between events in the low and the high stress drop categories. I test whether the spatial patterns of the Shearer catalog stress drops can predict the categories of the 15 events. I find that they cannot, rather the large event stress drops are uncorrelated with the local mean stress drop from the Shearer catalog. These results imply that the regionalization of stress drops of small events does not extend to the larger events, at least with current standard techniques of stress drop estimation.

Titrating Oxygen Requirements During Exercise: Evaluation of a Standardized Single Walk Test Protocol.

PubMed

Giovacchini, Coral X; Mathews, Anne M; Lawlor, Brian R; MacIntyre, Neil R

2018-04-01

Oxygen supplementation for exercise-induced hypoxemia is a common clinical practice that improves exercise tolerance. However, we know of no standardized exercise oxygen titration protocol using a single walk test. We report our experience with a protocol developed in our laboratory. Our protocol is based on the 6-min walk test (6MWT). Pulse oximetry readings (oxygen saturation [Spo 2 ]) are monitored, and supplemental oxygen is added in 2 L/min increments to keep Spo 2 > 88%. This continues for at least 6 min of walking with the Spo 2 remaining > 88% for at least 3 min. The records of consecutive patients over 4 months undergoing this procedure were reviewed for test performance, oxygen titration results, and adverse events. Two hundred twenty-two patients were tested; only two prematurely terminated the protocol because of intractable dyspnea. One hundred fifty-six patients (38%) required oxygen supplementation, with the first titration most commonly occurring between 1 and 2 min of walking. Nine of the patients had the first titration after 5 min of walking. The average test duration was 7 min (maximum, 15 min). The average number of titrations was 2.2 (maximum six). Sixteen patients could not maintain Spo 2 > 88% for 3 min despite administration of 15 L/min of supplemental oxygen (maximal dose). Our protocol was easily performed as a modification of a standard 6MWT with no serious adverse events. Because it is based on a widely accepted measurement of functional capabilities, and because it determined a stable final oxygen dose for ≥ 3 min of walking in most patients, we believe this protocol can be easily adapted for clinical use. Copyright © 2017 American College of Chest Physicians. Published by Elsevier Inc. All rights reserved.

Evaluating Composite Sampling Methods of Bacillus Spores at Low Concentrations

PubMed Central

Hess, Becky M.; Amidan, Brett G.; Anderson, Kevin K.; Hutchison, Janine R.

2016-01-01

Restoring all facility operations after the 2001 Amerithrax attacks took years to complete, highlighting the need to reduce remediation time. Some of the most time intensive tasks were environmental sampling and sample analyses. Composite sampling allows disparate samples to be combined, with only a single analysis needed, making it a promising method to reduce response times. We developed a statistical experimental design to test three different composite sampling methods: 1) single medium single pass composite (SM-SPC): a single cellulose sponge samples multiple coupons with a single pass across each coupon; 2) single medium multi-pass composite: a single cellulose sponge samples multiple coupons with multiple passes across each coupon (SM-MPC); and 3) multi-medium post-sample composite (MM-MPC): a single cellulose sponge samples a single surface, and then multiple sponges are combined during sample extraction. Five spore concentrations of Bacillus atrophaeus Nakamura spores were tested; concentrations ranged from 5 to 100 CFU/coupon (0.00775 to 0.155 CFU/cm2). Study variables included four clean surface materials (stainless steel, vinyl tile, ceramic tile, and painted dry wallboard) and three grime coated/dirty materials (stainless steel, vinyl tile, and ceramic tile). Analysis of variance for the clean study showed two significant factors: composite method (p< 0.0001) and coupon material (p = 0.0006). Recovery efficiency (RE) was higher overall using the MM-MPC method compared to the SM-SPC and SM-MPC methods. RE with the MM-MPC method for concentrations tested (10 to 100 CFU/coupon) was similar for ceramic tile, dry wall, and stainless steel for clean materials. RE was lowest for vinyl tile with both composite methods. Statistical tests for the dirty study showed RE was significantly higher for vinyl and stainless steel materials, but lower for ceramic tile. These results suggest post-sample compositing can be used to reduce sample analysis time when responding to a Bacillus anthracis contamination event of clean or dirty surfaces. PMID:27736999

Evaluating Composite Sampling Methods of Bacillus Spores at Low Concentrations.

PubMed

Hess, Becky M; Amidan, Brett G; Anderson, Kevin K; Hutchison, Janine R

2016-01-01

Restoring all facility operations after the 2001 Amerithrax attacks took years to complete, highlighting the need to reduce remediation time. Some of the most time intensive tasks were environmental sampling and sample analyses. Composite sampling allows disparate samples to be combined, with only a single analysis needed, making it a promising method to reduce response times. We developed a statistical experimental design to test three different composite sampling methods: 1) single medium single pass composite (SM-SPC): a single cellulose sponge samples multiple coupons with a single pass across each coupon; 2) single medium multi-pass composite: a single cellulose sponge samples multiple coupons with multiple passes across each coupon (SM-MPC); and 3) multi-medium post-sample composite (MM-MPC): a single cellulose sponge samples a single surface, and then multiple sponges are combined during sample extraction. Five spore concentrations of Bacillus atrophaeus Nakamura spores were tested; concentrations ranged from 5 to 100 CFU/coupon (0.00775 to 0.155 CFU/cm2). Study variables included four clean surface materials (stainless steel, vinyl tile, ceramic tile, and painted dry wallboard) and three grime coated/dirty materials (stainless steel, vinyl tile, and ceramic tile). Analysis of variance for the clean study showed two significant factors: composite method (p< 0.0001) and coupon material (p = 0.0006). Recovery efficiency (RE) was higher overall using the MM-MPC method compared to the SM-SPC and SM-MPC methods. RE with the MM-MPC method for concentrations tested (10 to 100 CFU/coupon) was similar for ceramic tile, dry wall, and stainless steel for clean materials. RE was lowest for vinyl tile with both composite methods. Statistical tests for the dirty study showed RE was significantly higher for vinyl and stainless steel materials, but lower for ceramic tile. These results suggest post-sample compositing can be used to reduce sample analysis time when responding to a Bacillus anthracis contamination event of clean or dirty surfaces.

Evaluating Composite Sampling Methods of Bacillus spores at Low Concentrations

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

Hess, Becky M.; Amidan, Brett G.; Anderson, Kevin K.

Restoring facility operations after the 2001 Amerithrax attacks took over three months to complete, highlighting the need to reduce remediation time. The most time intensive tasks were environmental sampling and sample analyses. Composite sampling allows disparate samples to be combined, with only a single analysis needed, making it a promising method to reduce response times. We developed a statistical experimental design to test three different composite sampling methods: 1) single medium single pass composite: a single cellulose sponge samples multiple coupons; 2) single medium multi-pass composite: a single cellulose sponge is used to sample multiple coupons; and 3) multi-medium post-samplemore » composite: a single cellulose sponge samples a single surface, and then multiple sponges are combined during sample extraction. Five spore concentrations of Bacillus atrophaeus Nakamura spores were tested; concentrations ranged from 5 to 100 CFU/coupon (0.00775 to 0.155CFU/cm2, respectively). Study variables included four clean surface materials (stainless steel, vinyl tile, ceramic tile, and painted wallboard) and three grime coated/dirty materials (stainless steel, vinyl tile, and ceramic tile). Analysis of variance for the clean study showed two significant factors: composite method (p-value < 0.0001) and coupon material (p-value = 0.0008). Recovery efficiency (RE) was higher overall using the post-sample composite (PSC) method compared to single medium composite from both clean and grime coated materials. RE with the PSC method for concentrations tested (10 to 100 CFU/coupon) was similar for ceramic tile, painted wall board, and stainless steel for clean materials. RE was lowest for vinyl tile with both composite methods. Statistical tests for the dirty study showed RE was significantly higher for vinyl and stainless steel materials, but significantly lower for ceramic tile. These results suggest post-sample compositing can be used to reduce sample analysis time when responding to a Bacillus anthracis contamination event of clean or dirty surfaces.« less

Combining Microinjection and Immunoblotting to Analyze MAP Kinase Phosphorylation in Single Starfish Oocytes and Eggs

NASA Astrophysics Data System (ADS)

Carroll, David J.; Hua, Wei

The starfish oocyte has proven useful for studies involving microinjection because it is relatively large (190 μm) and optically clear. These oocytes are easily obtained from the ovary arrested at prophase of meiosis I, making them useful as a model system for the study of cell cycle-related events. In this chapter, a method for combining microinjection with immunoblotting of single cells is described. Individual starfish oocytes are injected, removed from the microinjection chamber, and analyzed by immunoblotting for the dual-phosphorylated form of mitogen-activated protein kinase (MAPK). This method will allow for experiments testing the regulation of MAPK in single cells and for the manipulation of these cells by a quantitative microinjection technique.

Multiplex Droplet Digital PCR Protocols for Quantification of GM Maize Events.

PubMed

Dobnik, David; Spilsberg, Bjørn; Bogožalec Košir, Alexandra; Štebih, Dejan; Morisset, Dany; Holst-Jensen, Arne; Žel, Jana

2018-01-01

The standard-curve based simplex quantitative polymerase chain reaction (qPCR) has been the gold standard for DNA target quantification for more than a decade. The large and growing number of individual analyses needed to test for genetically modified organisms (GMOs) is reducing the cost-effectiveness of qPCR. Droplet digital PCR (ddPCR) enables absolute quantification without standard curves, avoids the amplification efficiency bias observed with qPCR, allows more accurate estimations at low target copy numbers and, in combination with multiplexing, significantly improves cost efficiency. Here we describe two protocols for multiplex quantification of GM maize events: (1) nondiscriminating, with multiplex quantification of targets as a group (12 GM maize lines) and (2) discriminating, with multiplex quantification of individual targets (events). The first enables the quantification of twelve European Union authorized GM maize events as a group with only two assays, but does not permit determination of the individual events present. The second protocol enables the quantification of four individual targets (three GM events and one endogene) in a single reaction. Both protocols can be modified for quantification of any other DNA target.

Multiple-Event, Single-Photon Counting Imaging Sensor

NASA Technical Reports Server (NTRS)

Zheng, Xinyu; Cunningham, Thomas J.; Sun, Chao; Wang, Kang L.

2011-01-01

The single-photon counting imaging sensor is typically an array of silicon Geiger-mode avalanche photodiodes that are monolithically integrated with CMOS (complementary metal oxide semiconductor) readout, signal processing, and addressing circuits located in each pixel and the peripheral area of the chip. The major problem is its single-event method for photon count number registration. A single-event single-photon counting imaging array only allows registration of up to one photon count in each of its pixels during a frame time, i.e., the interval between two successive pixel reset operations. Since the frame time can t be too short, this will lead to very low dynamic range and make the sensor merely useful for very low flux environments. The second problem of the prior technique is a limited fill factor resulting from consumption of chip area by the monolithically integrated CMOS readout in pixels. The resulting low photon collection efficiency will substantially ruin any benefit gained from the very sensitive single-photon counting detection. The single-photon counting imaging sensor developed in this work has a novel multiple-event architecture, which allows each of its pixels to register as more than one million (or more) photon-counting events during a frame time. Because of a consequently boosted dynamic range, the imaging array of the invention is capable of performing single-photon counting under ultra-low light through high-flux environments. On the other hand, since the multiple-event architecture is implemented in a hybrid structure, back-illumination and close-to-unity fill factor can be realized, and maximized quantum efficiency can also be achieved in the detector array.

Single event upset in avionics

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

Taber, A.; Normand, E.

1993-04-01

Data from military/experimental flights and laboratory testing indicate that typical non radiation-hardened 64K and 256K static random access memories (SRAMs) can experience a significant soft upset rate at aircraft altitudes due to energetic neutrons created by cosmic ray interactions in the atmosphere. It is suggested that error detection and correction (EDAC) circuitry be considered for all avionics designs containing large amounts of semi-conductor memory.

Goal Structured Notation in a Radiation Hardening Safety Case for COTS-Based Spacecraft

NASA Technical Reports Server (NTRS)

Witulski, Arthur; Austin, Rebekah; Reed, Robert; Karsai, Gabor; Mahadevan, Nag; Sierawski, Brian; Evans, John; LaBel, Ken

2016-01-01

A systematic approach is presented to constructing a radiation assurance case using Goal Structured Notation (GSN) for spacecraft containing COTS parts. The GSN paradigm is applied to an SRAM single-event upset experiment board designed to fly on a CubeSat November 2016. Construction of a radiation assurance case without use of hardened parts or extensive radiation testing is discussed.

Attention benefits after a single dose of metadoxine extended release in adults with predominantly inattentive ADHD.

PubMed

Manor, Iris; Rubin, Jonathan; Daniely, Yaron; Adler, Lenard A

2014-09-01

To assess the first-dose effectiveness and tolerability of metadoxine extended release (MDX) in adults with predominantly inattentive attention-deficit/hyperactivity disorder (ADHD-PI). In this double-blind, placebo-controlled, crossover study, adults with ADHD-PI were randomized 1:1:1 to receive a single dose of MDX 1400 mg, MDX 700 mg, and placebo (ClinicalTrials.gov identifier: NCT01685281). The primary efficacy end point was the mean change in the Test of Variables of Attention (TOVA) ADHD score from baseline to 3 to 5 hours after drug administration. Secondary assessments included TOVA subscores, TOVA response rates (defined as an increase of 0.8 points in the TOVA ADHD score), and the Cambridge Neuropsychological Automated Test Battery. Safety assessments included adverse events and vital signs. The intention-to-treat population included 36 patients (52.8% men; mean age, 32 years). The efficacy of MDX 1400 mg was demonstrated by a statistically significant difference in the mean (± SD) change in the TOVA ADHD score at baseline to 3 to 5 hours after drug administration compared with placebo (2.0 [4.2]; P = 0.009). The TOVA response time variability subscore was significantly different between MDX 1400 mg and placebo (mean difference, 7.9 [19.2] points; P = 0.022). Significantly more adults responded to single-dose MDX 1400 mg versus placebo (97.1% vs 71.4%, P = 0.006). There were no statistically significant differences between MDX 700 mg and placebo on any measures. Exploratory analyses of the Cambridge Neuropsychological Automated Test Battery did not yield significant findings. Fatigue and headache were the 2 most frequently reported adverse events. There were no clinically significant abnormalities in laboratory values, vital signs measurements, Columbia-Suicide Severity Rating Scale scores, or electrocardiographic parameters. Single-dose MDX 1400 mg significantly improved sustained and selective attention in adults with ADHD-PI as measured by the TOVA ADHD score 3 to 5 hours after drug administration. Single doses of MDX 700 and 1400 mg were well tolerated.

Nonvolatile Memory Technology for Space Applications

NASA Technical Reports Server (NTRS)

Oldham, Timothy R.; Irom, Farokh; Friendlich, Mark; Nguyen, Duc; Kim, Hak; Berg, Melanie; LaBel, Kenneth A.

2010-01-01

This slide presentation reviews several forms of nonvolatile memory for use in space applications. The intent is to: (1) Determine inherent radiation tolerance and sensitivities, (2) Identify challenges for future radiation hardening efforts, (3) Investigate new failure modes and effects, and technology modeling programs. Testing includes total dose, single event (proton, laser, heavy ion), and proton damage (where appropriate). Test vehicles are expected to be a variety of non-volatile memory devices as available including Flash (NAND and NOR), Charge Trap, Nanocrystal Flash, Magnetic Memory (MRAM), Phase Change--Chalcogenide, (CRAM), Ferroelectric (FRAM), CNT, and Resistive RAM.

The Galileo Attitude and Articulation Control System - A radiation-hard, high precision, state-of-the-art control system

NASA Technical Reports Server (NTRS)

Rhoads Stephenson, R.

1986-01-01

The Galileo Mission and Spacecraft design impose tight requirements on the Attitude and Articulation Control System (AACS). These requirements, coupled with the flexible spacecraft, the need for autonomy, and a severe radiation environment, pose a great challenge for the AACS designer. The resulting design and implementation are described, along with the discovery and solution of the Single-Event Upset problem. The status of the testing of the AACS in the Integration and Test Laboratory as well as at the spacecraft level is summarized.

Reasoning about conjunctive probabilistic concepts in childhood.

PubMed

Fisk, John E; Slattery, Rachel

2005-09-01

While adults are known to exhibit biases when making conjunctive probability judgments, little is known about childhood competencies in this area. Participants (aged between four and five years, eight and ten years, and a group of young adults) attempted to select the more likely of two events, a single event, and a conjunctive event containing, as one of its components, the single event. The problems were such that the objective probabilities of the component events were potentially available. Children in both age groups were generally successful when the single event was likely. However, when it was unlikely, a majority of children rejected it, choosing the conjunctive event instead, thereby committing the conjunction fallacy. A substantial minority of adults also committed the fallacy under equivalent conditions. It is concluded that under certain conditions children are capable of normative conjunctive judgments but that the mechanisms underpinning this capacity remain to be fully understood.

Single-Event Transgene Product Levels Predict Levels in Genetically Modified Breeding Stacks.

PubMed

Gampala, Satyalinga Srinivas; Fast, Brandon J; Richey, Kimberly A; Gao, Zhifang; Hill, Ryan; Wulfkuhle, Bryant; Shan, Guomin; Bradfisch, Greg A; Herman, Rod A

2017-09-13

The concentration of transgene products (proteins and double-stranded RNA) in genetically modified (GM) crop tissues is measured to support food, feed, and environmental risk assessments. Measurement of transgene product concentrations in breeding stacks of previously assessed and approved GM events is required by many regulatory authorities to evaluate unexpected transgene interactions that might affect expression. Research was conducted to determine how well concentrations of transgene products in single GM events predict levels in breeding stacks composed of these events. The concentrations of transgene products were compared between GM maize, soybean, and cotton breeding stacks (MON-87427 × MON-89034 × DAS-Ø15Ø7-1 × MON-87411 × DAS-59122-7 × DAS-40278-9 corn, DAS-81419-2 × DAS-44406-6 soybean, and DAS-21023-5 × DAS-24236-5 × SYN-IR102-7 × MON-88913-8 × DAS-81910-7 cotton) and their component single events (MON-87427, MON-89034, DAS-Ø15Ø7-1, MON-87411, DAS-59122-7, and DAS-40278-9 corn, DAS-81419-2, and DAS-44406-6 soybean, and DAS-21023-5, DAS-24236-5, SYN-IR102-7, MON-88913-8, and DAS-81910-7 cotton). Comparisons were made within a crop and transgene product across plant tissue types and were also made across transgene products in each breeding stack for grain/seed. Scatter plots were generated comparing expression in the stacks to their component events, and the percent of variability accounted for by the line of identity (y = x) was calculated (coefficient of identity, I 2 ). Results support transgene concentrations in single events predicting similar concentrations in breeding stacks containing the single events. Therefore, food, feed, and environmental risk assessments based on concentrations of transgene products in single GM events are generally applicable to breeding stacks composed of these events.

Low frequency events on Montserrat

NASA Astrophysics Data System (ADS)

Visser, K.; Neuberg, J.

2003-04-01

Earthquake swarms observed on volcanoes consist generally of low frequency events. The low frequency content of these events indicates the presence of interface waves at the boundary of the magma filled conduit and the surrounding country rock. The observed seismic signal at the surface shows therefore a complicated interference pattern of waves originating at various parts of the magma filled conduit, interacting with the free surface and interfaces in the volcanic edifice. This research investigates the applicability of conventional seismic tools on these low frequency events, focusing on hypocenter location analysis using arrival times and particle motion analysis for the Soufrière Hills Volcano on Montserrat. Both single low frequency events and swarms are observed on this volcano. Synthetic low frequency events are used for comparison. Results show that reliable hypocenter locations and particle motions can only be obtained if the low frequency events are single events with an identifiable P wave onset, for example the single events preceding swarms on Montserrat or the first low frequency event of a swarm. Consecutive events of the same swarm are dominated by interface waves which are converted at the top of the conduit into weak secondary P waves and surface waves. Conventional seismic tools fail to correctly analyse these events.

Use of Proton SEE Data as a Proxy for Bounding Heavy-Ion SEE Susceptibility

NASA Technical Reports Server (NTRS)

Ladbury, Raymond L.; Lauenstein, Jean-Marie; Hayes, Kathryn P.

2015-01-01

Although heavy-ion single-event effects (SEE) pose serious threats to semiconductor devices in space, many missions face difficulties testing such devices at heavy-ion accelerators. Low-cost missions often find such testing too costly. Even well funded missions face issues testing commercial off the shelf (COTS) due to packaging and integration. Some missions wish to fly COTS systems with little insight into their components. Heavy-ion testing such parts and systems requires access to expensive and hard-to-access ultra-high energy ion accelerators, or significant system modification. To avoid these problems, some have proposed using recoil ions from high-energy protons as a proxy to bound heavy-ion SEE rates.

Characterization of radiation effects in 65 nm digital circuits with the DRAD digital radiation test chip

NASA Astrophysics Data System (ADS)

Jara Casas, L. M.; Ceresa, D.; Kulis, S.; Miryala, S.; Christiansen, J.; Francisco, R.; Gnani, D.

2017-02-01

A Digital RADiation (DRAD) test chip has been specifically designed to study the impact of Total Ionizing Dose (TID) (<1 Grad) and Single Event Upset (SEU) on digital logic gates in a 65 nm CMOS technology. Nine different versions of standard cell libraries are studied in this chip, basically differing in the device dimensions, Vt flavor and layout of the device. Each library has eighteen test structures specifically designed to characterize delay degradation and power consumption of the standard cells. For SEU study, a dedicated test structure based on a shift register is designed for each library. TID results up to 500 Mrad are reported.

Comparison of event landslide inventories: the Pogliaschina catchment test case, Italy

NASA Astrophysics Data System (ADS)

Mondini, A. C.; Viero, A.; Cavalli, M.; Marchi, L.; Herrera, G.; Guzzetti, F.

2014-07-01

Event landslide inventory maps document the extent of populations of landslides caused by a single natural trigger, such as an earthquake, an intense rainfall event, or a rapid snowmelt event. Event inventory maps are important for landslide susceptibility and hazard modelling, and prove useful to manage residual risk after a landslide-triggering event. Standards for the preparation of event landslide inventory maps are lacking. Traditional methods are based on the visual interpretation of stereoscopic aerial photography, aided by field surveys. New and emerging techniques exploit remotely sensed data and semi-automatic algorithms. We describe the production and comparison of two independent event inventories prepared for the Pogliaschina catchment, Liguria, Northwest Italy. The two inventories show landslides triggered by an intense rainfall event on 25 October 2011, and were prepared through the visual interpretation of digital aerial photographs taken 3 days and 33 days after the event, and by processing a very-high-resolution image taken by the WorldView-2 satellite 4 days after the event. We compare the two inventories qualitatively and quantitatively using established and new metrics, and we discuss reasons for the differences between the two landslide maps. We expect that the results of our work can help in deciding on the most appropriate method to prepare reliable event inventory maps, and outline the advantages and the limitations of the different approaches.

A systematic review of the association between a single strenuous event and the development of an inguinal hernia: A medicolegal grey area.

PubMed

Patterson, Timothy; Currie, Peter; Spence, Robert; McNally, Sinead; Spence, Gary

2018-03-10

Inguinal hernia is a common surgical presentation. Evidence for its causation regarding occupational and recreational physical exposures is limited. The aim of this study is to conduct a systematic review objectively evaluating the evidence for a causal link between a single strenuous event and the development of an inguinal hernia. A systematic review was carried out in accordance with PRISMA guidelines. PubMed, Ovid Embase, SCOPUS, and Cochrane Library were searched. In addition, the ISRCTN register, ClinicalTrials.gov, ICTR Platform, and EU Clinical Trials Register were searched. Identified publications were collated and both reviewers independently reviewed their contents. 5508 records were identified, resulting in 5 studies being selected. These 5 studies were all case series. Of 957 patients identified, 1003 hernias were described, of which 983 were inguinal hernias which 255 (26%) were attributed by patients to a single strenuous event. Only two of these studies applied Smith's Criteria (causation of a hernia from a single strenuous event): officially reported, severe pain at the time of the event, no prior history of inguinal hernia, and the diagnosis was made by a doctor within 30 days (preferably 3 days). Only 2 of 54 patients (4%) met all four criteria and so could be considered as having an inguinal hernia relating to a single strenuous event. Many patients associate hernias to a single episode, however upon application of more stringent criteria such as Smith's, a much smaller proportion are deemed to be actually attributable to a single strenuous event. Copyright © 2018 Royal College of Surgeons of Edinburgh (Scottish charity number SC005317) and Royal College of Surgeons in Ireland. Published by Elsevier Ltd. All rights reserved.

Single-Event Effect (SEE) Survey of Advanced Reconfigurable Field Programmable Gate Arrays: NASA Electronic Parts and Packaging (NEPP) Program Office of Safety and Mission Assurance

NASA Technical Reports Server (NTRS)

Allen, Gregory

2011-01-01

The NEPP Reconfigurable Field-Programmable Gate Array (FPGA) task has been charged to evaluate reconfigurable FPGA technologies for use in space. Under this task, the Xilinx single-event-immune, reconfigurable FPGA (SIRF) XQR5VFX130 device was evaluated for SEE. Additionally, the Altera Stratix-IV and SiliconBlue iCE65 were screened for single-event latchup (SEL).

On the use of Lineal Energy Measurements to Estimate Linear Energy Transfer Spectra

NASA Technical Reports Server (NTRS)

Adams, David A.; Howell, Leonard W., Jr.; Adam, James H., Jr.

2007-01-01

This paper examines the error resulting from using a lineal energy spectrum to represent a linear energy transfer spectrum for applications in the space radiation environment. Lineal energy and linear energy transfer spectra are compared in three diverse but typical space radiation environments. Different detector geometries are also studied to determine how they affect the error. LET spectra are typically used to compute dose equivalent for radiation hazard estimation and single event effect rates to estimate radiation effects on electronics. The errors in the estimations of dose equivalent and single event rates that result from substituting lineal energy spectra for linear energy spectra are examined. It is found that this substitution has little effect on dose equivalent estimates in interplanetary quiet-time environment regardless of detector shape. The substitution has more of an effect when the environment is dominated by solar energetic particles or trapped radiation, but even then the errors are minor especially if a spherical detector is used. For single event estimation, the effect of the substitution can be large if the threshold for the single event effect is near where the linear energy spectrum drops suddenly. It is judged that single event rate estimates made from lineal energy spectra are unreliable and the use of lineal energy spectra for single event rate estimation should be avoided.

The t-CWT: a new ERP detection and quantification method based on the continuous wavelet transform and Student's t-statistics.

PubMed

Bostanov, Vladimir; Kotchoubey, Boris

2006-12-01

This study was aimed at developing a method for extraction and assessment of event-related brain potentials (ERP) from single-trials. This method should be applicable in the assessment of single persons' ERPs and should be able to handle both single ERP components and whole waveforms. We adopted a recently developed ERP feature extraction method, the t-CWT, for the purposes of hypothesis testing in the statistical assessment of ERPs. The t-CWT is based on the continuous wavelet transform (CWT) and Student's t-statistics. The method was tested in two ERP paradigms, oddball and semantic priming, by assessing individual-participant data on a single-trial basis, and testing the significance of selected ERP components, P300 and N400, as well as of whole ERP waveforms. The t-CWT was also compared to other univariate and multivariate ERP assessment methods: peak picking, area computation, discrete wavelet transform (DWT) and principal component analysis (PCA). The t-CWT produced better results than all of the other assessment methods it was compared with. The t-CWT can be used as a reliable and powerful method for ERP-component detection and testing of statistical hypotheses concerning both single ERP components and whole waveforms extracted from either single persons' or group data. The t-CWT is the first such method based explicitly on the criteria of maximal statistical difference between two average ERPs in the time-frequency domain and is particularly suitable for ERP assessment of individual data (e.g. in clinical settings), but also for the investigation of small and/or novel ERP effects from group data.

Stressful Life Event Experiences of Homeless Adults: A Comparison of Single Men, Single Women, and Women with Children

ERIC Educational Resources Information Center

Zugazaga, Carole

2004-01-01

This article describes stressful life events experienced by a multi-shelter sample of 162 homeless adults in the Central Florida area. Participants included homeless single men (n = 54), homeless single women (n = 54), and homeless women with children (n = 54). Subjects were interviewed with a modified version of the List of Threatening…

Heterogeneous distribution of exocytotic microdomains in adrenal chromaffin cells resolved by high-density diamond ultra-microelectrode arrays.

PubMed

Gosso, Sara; Turturici, Marco; Franchino, Claudio; Colombo, Elisabetta; Pasquarelli, Alberto; Carbone, Emilio; Carabelli, Valentina

2014-08-01

Here we describe the ability of a high-density diamond microelectrode array targeted to resolve multi-site detection of fast exocytotic events from single cells. The array consists of nine boron-doped nanocrystalline diamond ultra-microelectrodes (9-Ch NCD-UMEA) radially distributed within a circular area of the dimensions of a single cell. The device can be operated in voltammetric or chronoamperometric configuration. Sensitivity to catecholamines, tested by dose-response calibrations, set the lowest detectable concentration of adrenaline to ∼5 μm. Catecholamine release from bovine or mouse chromaffin cells could be triggered by electrical stimulation or external KCl-enriched solutions. Spikes detected from the cell apex using carbon fibre microelectrodes showed an excellent correspondence with events measured at the bottom of the cell by the 9-Ch NCD-UMEA, confirming the ability of the array to resolve single quantal secretory events. Subcellular localization of exocytosis was provided by assigning each quantal event to one of the nine channels based on its location. The resulting mapping highlights the heterogeneous distribution of secretory activity in cell microdomains of 12-27 μm2. In bovine chromaffin cells, secretion was highly heterogeneous with zones of high and medium activity in 54% of the cell surface and zones of low or no activity in the remainder. The 'non-active' ('silent') zones covered 24% of the total and persisted for 6-8 min, indicating stable location. The 9-Ch NCD-UMEA therefore appears suitable for investigating the microdomain organization of neurosecretion with high spatial resolution. © 2014 The Authors. The Journal of Physiology © 2014 The Physiological Society.

Bleeding complications in BCR-ABL negative myeloproliferative neoplasms: prevalence, type, and risk factors in a single-center cohort.

PubMed

Kander, Elizabeth M; Raza, Sania; Zhou, Zheng; Gao, Juehua; Zakarija, Anaadriana; McMahon, Brandon J; Stein, Brady L

2015-11-01

The BCR-ABL1-negative myeloproliferative neoplasms (MPN) share an increased risk of thrombotic and hemorrhagic complications. Risk factors for hemorrhage are less well defined than those for thrombosis. Because patients with CALR mutations have higher platelet counts compared to JAK2 V617F-mutated patients, bleeding rates may be increased in this group. Our aim was to retrospectively evaluate whether acquired von Willebrand disease (AvWD), thrombocytosis, mutational status, or treatment history are associated with bleeding in a cohort of MPN patients. Using an electronic database, MPN patients seen between 2005 and 2013 were retrospectively identified using ICD-9 codes and billing records. A bleeding event was defined as one that was identified in the medical record and graded based on the Common Terminology Criteria for Adverse Event (CTCAE) version 4.0. Among 351 MPN patients, 15.6 % experienced 64 bleeding event types. There was no association of bleeding with mutational status, gender, MPN subtype, aspirin use, prior thrombosis, or platelet count at presentation. There was an association between bleeding and older age at diagnosis. aVWD was identified in six patients. In this single-center retrospective study, bleeding events were identified in 15 % of patients, and associated with older age at diagnosis. aVWD was rarely tested for in this cohort.

Phagocytosis as a biomarker for stress responses

NASA Astrophysics Data System (ADS)

Huber, K.; Krotz-Fahning, M.; Hock, B.

2005-08-01

An in vitro test has been developed for the detection of immunotoxic events. It will be used within the project "TRIPLE LUX" on the International Space Station to investigate the effects of single and combined space flight conditions on mammalian phagocytes. The intensity of the respiratory burst during phagocytosis can be followed by the luminol-based chemiluminescence response after stimulation with zymosan. We adapted this test system for polymorphonuclear leukocytes, purified from sheep blood and stored by cryoconservation. In this report we show the immunostimulating effect of hydrocortisone and the immunosuppressive impact of cadmium as an example for alterations that can be detected by this test.

A panning DLT procedure for three-dimensional videography.

PubMed

Yu, B; Koh, T J; Hay, J G

1993-06-01

The direct linear transformation (DLT) method [Abdel-Aziz and Karara, APS Symposium on Photogrammetry. American Society of Photogrammetry, Falls Church, VA (1971)] is widely used in biomechanics to obtain three-dimensional space coordinates from film and video records. This method has some major shortcomings when used to analyze events which take place over large areas. To overcome these shortcomings, a three-dimensional data collection method based on the DLT method, and making use of panning cameras, was developed. Several small single control volumes were combined to construct a large total control volume. For each single control volume, a regression equation (calibration equation) is developed to express each of the 11 DLT parameters as a function of camera orientation, so that the DLT parameters can then be estimated from arbitrary camera orientations. Once the DLT parameters are known for at least two cameras, and the associated two-dimensional film or video coordinates of the event are obtained, the desired three-dimensional space coordinates can be computed. In a laboratory test, five single control volumes (in a total control volume of 24.40 x 2.44 x 2.44 m3) were used to test the effect of the position of the single control volume on the accuracy of the computed three dimensional space coordinates. Linear and quadratic calibration equations were used to test the effect of the order of the equation on the accuracy of the computed three dimensional space coordinates. For four of the five single control volumes tested, the mean resultant errors associated with the use of the linear calibration equation were significantly larger than those associated with the use of the quadratic calibration equation. The position of the single control volume had no significant effect on the mean resultant errors in computed three dimensional coordinates when the quadratic calibration equation was used. Under the same data collection conditions, the mean resultant errors in the computed three dimensional coordinates associated with the panning and stationary DLT methods were 17 and 22 mm, respectively. The major advantages of the panning DLT method lie in the large image sizes obtained and in the ease with which the data can be collected. The method also has potential for use in a wide variety of contexts. The major shortcoming of the method is the large amount of digitizing necessary to calibrate the total control volume. Adaptations of the method to reduce the amount of digitizing required are being explored.

Multiple-Event Seismic Location Using the Markov-Chain Monte Carlo Technique

NASA Astrophysics Data System (ADS)

Myers, S. C.; Johannesson, G.; Hanley, W.

2005-12-01

We develop a new multiple-event location algorithm (MCMCloc) that utilizes the Markov-Chain Monte Carlo (MCMC) method. Unlike most inverse methods, the MCMC approach produces a suite of solutions, each of which is consistent with observations and prior estimates of data and model uncertainties. Model parameters in MCMCloc consist of event hypocenters, and travel-time predictions. Data are arrival time measurements and phase assignments. Posteriori estimates of event locations, path corrections, pick errors, and phase assignments are made through analysis of the posteriori suite of acceptable solutions. Prior uncertainty estimates include correlations between travel-time predictions, correlations between measurement errors, the probability of misidentifying one phase for another, and the probability of spurious data. Inclusion of prior constraints on location accuracy allows direct utilization of ground-truth locations or well-constrained location parameters (e.g. from InSAR) that aid in the accuracy of the solution. Implementation of a correlation structure for travel-time predictions allows MCMCloc to operate over arbitrarily large geographic areas. Transition in behavior between a multiple-event locator for tightly clustered events and a single-event locator for solitary events is controlled by the spatial correlation of travel-time predictions. We test the MCMC locator on a regional data set of Nevada Test Site nuclear explosions. Event locations and origin times are known for these events, allowing us to test the features of MCMCloc using a high-quality ground truth data set. Preliminary tests suggest that MCMCloc provides excellent relative locations, often outperforming traditional multiple-event location algorithms, and excellent absolute locations are attained when constraints from one or more ground truth event are included. When phase assignments are switched, we find that MCMCloc properly corrects the error when predicted arrival times are separated by several seconds. In cases where the predicted arrival times are within the combined uncertainty of prediction and measurement errors, MCMCloc determines the probability of one or the other phase assignment and propagates this uncertainty into all model parameters. We find that MCMCloc is a promising method for simultaneously locating large, geographically distributed data sets. Because we incorporate prior knowledge on many parameters, MCMCloc is ideal for combining trusted data with data of unknown reliability. This work was performed under the auspices of the U.S. Department of Energy by the University of California Lawrence Livermore National Laboratory under contract No. W-7405-Eng-48, Contribution UCRL-ABS-215048

Quantifying full phenological event distributions reveals simultaneous advances, temporal stability and delays in spring and autumn migration timing in long-distance migratory birds.

PubMed

Miles, Will T S; Bolton, Mark; Davis, Peter; Dennis, Roy; Broad, Roger; Robertson, Iain; Riddiford, Nick J; Harvey, Paul V; Riddington, Roger; Shaw, Deryk N; Parnaby, David; Reid, Jane M

2017-04-01

Phenological changes in key seasonally expressed life-history traits occurring across periods of climatic and environmental change can cause temporal mismatches between interacting species, and thereby impact population and community dynamics. However, studies quantifying long-term phenological changes have commonly only measured variation occurring in spring, measured as the first or mean dates on which focal traits or events were observed. Few studies have considered seasonally paired events spanning spring and autumn or tested the key assumption that single convenient metrics accurately capture entire event distributions. We used 60 years (1955-2014) of daily bird migration census data from Fair Isle, Scotland, to comprehensively quantify the degree to which the full distributions of spring and autumn migration timing of 13 species of long-distance migratory bird changed across a period of substantial climatic and environmental change. In most species, mean spring and autumn migration dates changed little. However, the early migration phase (≤10th percentile date) commonly got earlier, while the late migration phase (≥90th percentile date) commonly got later. Consequently, species' total migration durations typically lengthened across years. Spring and autumn migration phenologies were not consistently correlated within or between years within species and hence were not tightly coupled. Furthermore, different metrics quantifying different aspects of migration phenology within seasons were not strongly cross-correlated, meaning that no single metric adequately described the full pattern of phenological change. These analyses therefore reveal complex patterns of simultaneous advancement, temporal stability and delay in spring and autumn migration phenologies, altering species' life-history structures. Additionally, they demonstrate that this complexity is only revealed if multiple metrics encompassing entire seasonal event distributions, rather than single metrics, are used to quantify phenological change. Existing evidence of long-term phenological changes detected using only one or two metrics should consequently be interpreted cautiously because divergent changes occurring simultaneously could potentially have remained undetected. © 2016 John Wiley & Sons Ltd.

A new approach for deciphering between single and multiple accumulation events using intra-tooth isotopic variations: Application to the Middle Pleistocene bone bed of Schöningen 13 II-4.

PubMed

Julien, Marie-Anne; Rivals, Florent; Serangeli, Jordi; Bocherens, Hervé; Conard, Nicholas J

2015-12-01

It is often difficult to differentiate between archaeological bonebeds formed by one event such as a mass kill of a single herd, and those formed by multiple events that occurred over a longer period of time. The application of high temporal resolution studies such as intra-tooth isotopic profiles on archaeological mammal cohorts offers new possibilities for exploring this issue, allowing investigators to decipher between single and multiple accumulation events. We examined (18)O and (13)C isotopic variations from the enamel carbonate of 23 horse third molars from the Middle Pleistocene archaeological site of Schöningen. We employed a new approach to investigate processes of fossil accumulation that uses both bulk and intra-tooth isotopic variations and takes into account animal behavior, age at death and dental development to test the degree of isotopic affinity of animals from the same fossil assemblage. Oxygen and carbon isotope bulk values indicate that the horses from Schöningen 13 II-4 experienced relatively similar climatic and dietary regimes. Inter-individual differences of the bulk values of the horses sampled in the current study present nevertheless inter-individual variability similar to individuals from multi-layered localities. In addition, the intra-tooth isotopic variation of specimens of the same age at death seems to indicate that the studied cohort corresponds to a mix of individuals that recorded both similar and different isotopic histories. Finally, the conditions recorded in the isotopic signal shortly before death (i.e., for teeth not fully mineralized) varied between sampled individuals, suggesting possible differences in the seasonality of death. Considering those results, we discuss the possibility that the horses from Schöningen 13 II-4 correspond to an accumulation of different death events. Copyright © 2015 Elsevier Ltd. All rights reserved.

Adaptive Stress Testing of Airborne Collision Avoidance Systems

NASA Technical Reports Server (NTRS)

Lee, Ritchie; Kochenderfer, Mykel J.; Mengshoel, Ole J.; Brat, Guillaume P.; Owen, Michael P.

2015-01-01

This paper presents a scalable method to efficiently search for the most likely state trajectory leading to an event given only a simulator of a system. Our approach uses a reinforcement learning formulation and solves it using Monte Carlo Tree Search (MCTS). The approach places very few requirements on the underlying system, requiring only that the simulator provide some basic controls, the ability to evaluate certain conditions, and a mechanism to control the stochasticity in the system. Access to the system state is not required, allowing the method to support systems with hidden state. The method is applied to stress test a prototype aircraft collision avoidance system to identify trajectories that are likely to lead to near mid-air collisions. We present results for both single and multi-threat encounters and discuss their relevance. Compared with direct Monte Carlo search, this MCTS method performs significantly better both in finding events and in maximizing their likelihood.

Single-Event Upsets Caused by High-Energy Protons

NASA Technical Reports Server (NTRS)

Price, W. E.; Nichols, D. K.; Smith, L. S.; Soli, G. A.

1986-01-01

Heavy secondary ions do not significantly alter device responses. Conclusion that external reaction products cause no significant alteration of single-event-upset response based on comparison of data obtained from both lidded and unlidded devices and for proton beams impinging at angles ranging from 0 degrees to 180 degrees with respect to chip face. Study also found single-event-upset cross section increases only modestly as proton energy increased to 590 MeV, characteristic of maximum energies expected in belts of trapped protons surrounding Earth and Jupiter.

Numerical 3D flow simulation of attached cavitation structures at ultrasonic horn tips and statistical evaluation of flow aggressiveness via load collectives

NASA Astrophysics Data System (ADS)

Mottyll, S.; Skoda, R.

2015-12-01

A compressible inviscid flow solver with barotropic cavitation model is applied to two different ultrasonic horn set-ups and compared to hydrophone, shadowgraphy as well as erosion test data. The statistical analysis of single collapse events in wall-adjacent flow regions allows the determination of the flow aggressiveness via load collectives (cumulative event rate vs collapse pressure), which show an exponential decrease in agreement to studies on hydrodynamic cavitation [1]. A post-processing projection of event rate and collapse pressure on a reference grid reduces the grid dependency significantly. In order to evaluate the erosion-sensitive areas a statistical analysis of transient wall loads is utilised. Predicted erosion sensitive areas as well as temporal pressure and vapour volume evolution are in good agreement to the experimental data.

Postglacial recolonization of eastern Blacknose Dace,Rhinichthys atratulus(Teleostei: Cyprinidae), through the gateway of New England

PubMed Central

Tipton, Michelle L; Gignoux-Wolfsohn, Sarah; Stonebraker, Phoebe; Chernoff, Barry

2011-01-01

During the last ice age, much of North America far south as 40°N was covered by glaciers (Hewitt 2000). About 20,000 years ago, as the glaciers retreated, the hydrologic landscape changed dramatically creating waterways for fish dispersal. The number of populations responsible for recolonization and the regions from which they recolonized are unknown for many freshwater fishes living in New England and southeastern Canada. The Blacknose Dace,Rhinichthys atratulus, is one of the freshwater fish species that recolonized this region. We hypothesize that the earliest deglaciated region, modern-day Connecticut, was recolonized byR. atratulusvia a single founding event by a single population. In this paper, we test this hypothesis phylogenetically with regard to the major drainage basins within Connecticut. The mitochondrial DNA exhibits low nucleotide diversity, high haplotype diversity, and a dominant haplotype found across the state. A small percentage of individuals in the Housatonic drainage basin, however, share a haplotype with populations in New York drainage basins, a haplotype not found elsewhere in Connecticut's drainage basins. We calculated a range for the rate of divergence for NADH dehydrogenase subunit 2 (nd2) and control region (ctr) of 4.43–6.76% and 3.84–8.48% per million years (my), respectively. While this range is higher than the commonly accepted rate of 2% for mitochondrial DNA, these results join a growing list of publications finding high rates of divergence for various taxa (Peterson and Masel 2009). The data support the conclusion that Connecticut as a whole was recolonized initially by a single founding event that came from a single refugium. Subsequently, the Housatonic basin alone experienced a secondary recolonization event. PMID:22393505

Postglacial recolonization of eastern Blacknose Dace,Rhinichthys atratulus(Teleostei: Cyprinidae), through the gateway of New England.

PubMed

Tipton, Michelle L; Gignoux-Wolfsohn, Sarah; Stonebraker, Phoebe; Chernoff, Barry

2011-11-01

During the last ice age, much of North America far south as 40°N was covered by glaciers (Hewitt 2000). About 20,000 years ago, as the glaciers retreated, the hydrologic landscape changed dramatically creating waterways for fish dispersal. The number of populations responsible for recolonization and the regions from which they recolonized are unknown for many freshwater fishes living in New England and southeastern Canada. The Blacknose Dace,Rhinichthys atratulus, is one of the freshwater fish species that recolonized this region. We hypothesize that the earliest deglaciated region, modern-day Connecticut, was recolonized byR. atratulusvia a single founding event by a single population. In this paper, we test this hypothesis phylogenetically with regard to the major drainage basins within Connecticut. The mitochondrial DNA exhibits low nucleotide diversity, high haplotype diversity, and a dominant haplotype found across the state. A small percentage of individuals in the Housatonic drainage basin, however, share a haplotype with populations in New York drainage basins, a haplotype not found elsewhere in Connecticut's drainage basins. We calculated a range for the rate of divergence for NADH dehydrogenase subunit 2 (nd2) and control region (ctr) of 4.43-6.76% and 3.84-8.48% per million years (my), respectively. While this range is higher than the commonly accepted rate of 2% for mitochondrial DNA, these results join a growing list of publications finding high rates of divergence for various taxa (Peterson and Masel 2009). The data support the conclusion that Connecticut as a whole was recolonized initially by a single founding event that came from a single refugium. Subsequently, the Housatonic basin alone experienced a secondary recolonization event.

A Phase 1, Single-center, Double-blind, Placebo-controlled Study in Healthy Subjects to Assess the Safety, Tolerability, Clinical Effects, and Pharmacokinetics-Pharmacodynamics of Intravenous Cyclopropyl-methoxycarbonylmetomidate (ABP-700) after a Single Ascending Bolus Dose.

PubMed

Struys, Michel M R F; Valk, Beatrijs I; Eleveld, Douglas J; Absalom, Anthony R; Meyer, Peter; Meier, Sascha; den Daas, Izaak; Chou, Thomas; van Amsterdam, Kai; Campagna, Jason A; Sweeney, Steven P

2017-07-01

Cyclopropyl-methoxycarbonylmetomidate (ABP-700) is a new "soft" etomidate analog. The primary objectives of this first-in-human study were to describe the safety and efficacy of ABP-700 and to determine its maximum tolerated dose. Secondary objectives were to characterize the pharmacokinetics of ABP-700 and its primary metabolite (cyclopropyl-methoxycarbonyl acid), to assess the clinical effects of ABP-700, and to investigate the dose-response and pharmacokinetic/pharmacodynamic relationships. Sixty subjects were divided into 10 cohorts and received an increasing, single bolus of either ABP-700 or placebo. Safety was assessed by clinical laboratory evaluations, infusion-site reactions, continuous monitoring of vital signs, physical examination, adverse event monitoring, and adrenocorticotropic hormone stimulation testing. Clinical effects were assessed with modified observer's assessment of alertness/sedation and Bispectral Index monitoring. Pharmacokinetic parameters were calculated. Stopping criteria were met at 1.00 mg/kg dose. No serious adverse events were reported. Adverse events were dose-dependent and comprised involuntary muscle movement, tachycardia, and ventilatory effects. Adrenocorticotropic hormone stimulation evoked a physiologic cortisol response in all subjects, no different from placebo. Pharmacokinetics were dose-proportional. A three-compartment pharmacokinetic model described the data well. A rapid onset of anesthesia/sedation after bolus administration and also a rapid recovery were observed. A quantitative concentration-effect relationship was described for the modified observer's assessment of alertness/sedation and Bispectral Index. This first-in-human study of ABP-700 shows that ABP-700 was safe and well tolerated after single-bolus injections up to 1.00 mg/kg. Bolus doses of 0.25 and 0.35 mg/kg were found to provide the most beneficial clinical effect versus side-effect profile.

Verification and Quantification of Single Event Effects on High Speed SRAM in Terrestrial Environments

NASA Technical Reports Server (NTRS)

Huff, H.; You, Z.; Williams, T.; Nichols, T.; Attia, J.; Fogarty, T. N.; Kirby, K.; Wilkins, R.; Lawton, R.

1998-01-01

As integrated circuits become more sensitive to charged particles and neutrons, anomalous performance due to single event effects (SEE) is a concern and requires experimental verification and quantification. The Center for Applied Radiation Research (CARR) at Prairie View A&M University has developed experiments as a participant in the NASA ER-2 Flight Program, the APEX balloon flight program and the Student Launch Program. Other high altitude and ground level experiments of interest to DoD and commercial applications are being developed. The experiment characterizes the SEE behavior of high speed and high density SRAM's. The system includes a PC-104 computer unit, an optical drive for storage, a test board with the components under test, and a latchup detection and reset unit. The test program will continuously monitor the stored checkerboard data pattern in the SW and record errors. Since both the computer and the optical drive contain integrated circuits, they are also vulnerable to radiation effects. A latchup detection unit with discrete components will monitor the test program and reset the system when necessary. The first results will be obtained from the NASA ER-2 flights, which are now planned to take place in early 1998 from Dryden Research Center in California. The series of flights, at altitudes up to 70,000 feet, and a variety of flight profiles should yield a distribution of conditions for correlating SEES. SEE measurements will be performed from the time of aircraft power-up on the ground throughout the flight regime until systems power-off after landing.

Safety and immunogenicity of a single intramuscular dose of a tetanus-diphtheria toxoid (Td) vaccine (BR-TD-1001) in healthy Korean adult subjects.

PubMed

Hong, Taegon; Chung, Yong-Ju; Kim, Tae-Yeon; Kim, Ik-Hwan; Choe, Yong-Kyung; Lee, Jongtae; Jeon, Sangil; Han, Seunghoon; Yim, Dong-Seok

2015-01-01

BR-TD-1001 was developed as a booster for the immunity maintenance of diphtheria and tetanus. The aim of this study was to evaluate the safety and immunogenicity of BR-TD-1001 (test vaccine) in comparison with placebo and an active comparator in healthy Korean adults. A randomized, double-blind, placebo-controlled, active comparator, phase I clinical trial was conducted. Fifty subjects were randomly assigned to one of 3 treatment groups in a ratio of 2:2:1, and were administered a single intramuscular dose of test vaccine, active comparator, or placebo, respectively. All subjects were monitored for 4 weeks after injection. The antibody titers of the patients 2 and 4 weeks after vaccination were compared with the baseline. The frequencies of all adverse events including adverse drug reactions in the test group were not statistically different from those of the other treatment groups (P = 0.4974, 0.3061). No serious adverse event occurred, and no subject was withdrawn from the study for safety. The seroprotection rates against both tetanus and diphtheria at 4 weeks after vaccination were over 0.95. For anti-tetanus antibody, the geometric mean titer in the test group was significantly higher than those of the other groups (P = 0.0364, 0.0033). The geometric mean titer of anti-diphtheria antibody in the test group was significantly higher than the value of the placebo (P = 0.0347) while it was not for the value of the active comparator (P = 0.8484). In conclusion, BR-TD-1001 was safe, well-tolerated, and showed sufficient immunogenicity as a booster for diphtheria and tetanus.

1989 IEEE Annual Conference on Nuclear and Space Radiation Effects, 26th, Marco Island, FL, July 25-29, 1989, Proceedings. Part 1

NASA Technical Reports Server (NTRS)

Ochoa, Agustin, Jr. (Editor)

1989-01-01

Various papers on nuclear science are presented. The general topics addressed include: basic mechanics of radiation effects, dosimetry and energy-dependent effects, hardness assurance and testing techniques, spacecraft charging and space radiation effects, EMP/SGEMP/IEMP phenomena, device radiation effects and hardening, radiation effects on isolation technologies, IC radiation effects and hardening, and single-event phenomena.

Tactile Instrument for Aviation

DTIC Science & Technology

2000-07-30

response times using 8 tactor locations was repeated with a dual memory /tracking task or an air combat simulation to evaluate the effectiveness of the...Global Positioning/Inertial Navigation System technologies into a single system for evaluation in an UH-60 Helicopter. A 10-event test operation was... evaluation of the following technology areas need to be pursued: • Integration of tactile instruments with helmet mounted displays and 3D audio displays

Goal Structuring Notation in a Radiation Hardening Assurance Case for COTS-Based Spacecraft

NASA Technical Reports Server (NTRS)

Witulski, Arthur; Austin, Rebekah; Evans, John; Mahadevan, Nag; Karsai, Gabor; Sierawski, Brian; LaBel, Ken; Reed, Robert; Schrimpf, Ron

2016-01-01

A systematic approach is presented to constructing a radiation assurance case using Goal Structuring Notation (GSN) for spacecraft containing commercial-off-the-shelf (COTS) parts. The GSN paradigm is applied to an SRAM single-event upset experiment board designed to fly on a CubeSat November 2016. Construction of a radiation assurance case without use of hardened parts or extensive radiation testing is discussed.

TID and SEE Response of an Advanced Samsung 4G NAND Flash Memory

NASA Technical Reports Server (NTRS)

Oldham, Timothy R.; Friendlich, M.; Howard, J. W.; Berg, M. D.; Kim, H. S.; Irwin, T. L.; LaBel, K. A.

2007-01-01

Initial total ionizing dose (TID) and single event heavy ion test results are presented for an unhardened commercial flash memory, fabricated with 63 nm technology. Results are that the parts survive to a TID of nearly 200 krad (SiO2), with a tractable soft error rate of about 10(exp -l2) errors/bit-day, for the Adams Ten Percent Worst Case Environment.

Offshore Earthquakes Do Not Influence Marine Mammal Stranding Risk on the Washington and Oregon Coasts.

PubMed

Grant, Rachel A; Savirina, Anna; Hoppitt, Will

2018-01-26

The causes of marine mammals stranding on coastal beaches are not well understood, but may relate to topography, currents, wind, water temperature, disease, toxic algal blooms, and anthropogenic activity. Offshore earthquakes are a source of intense sound and disturbance and could be a contributing factor to stranding probability. We tested the hypothesis that the probability of marine mammal stranding events on the coasts of Washington and Oregon, USA is increased by the occurrence of offshore earthquakes in the nearby Cascadia subduction zone. The analysis carried out here indicated that earthquakes are at most, a very minor predictor of either single, or large (six or more animals) stranding events, at least for the study period and location. We also tested whether earthquakes inhibit stranding and again, there was no link. Although we did not find a substantial association of earthquakes with strandings in this study, it is likely that there are many factors influencing stranding of marine mammals and a single cause is unlikely to be responsible. Analysis of a subset of data for which detailed descriptions were available showed that most live stranded animals were pups, calves, or juveniles, and in the case of dead stranded mammals, the commonest cause of death was trauma, disease, and emaciation.

Using contests to ``spice up'' workshop physics

NASA Astrophysics Data System (ADS)

Duffy, M. G.; Warden, J. A.

1997-03-01

Once or twice each semester we give the students in our calculus-based Workshop Physics (1) course a problem dressed up as a contest. To "win," a team must correctly predict the outcome of a unique event and test that prediction within a single fifty minute class period. Successful teams win a home-cooked meal or other prize unrelated to course grade. We design a contest to focus cooperative effort, yet it also serves in ways like a problem session, review, or exam, but with no grade pressure. As illustrated by the sample contests exhibited on the poster, you can adjust the difficulty of these exercises to get a variety of different success rates. While this is hardly a novel idea, we provide it as a reminder that it is useful to step out of the normal homework, quiz, exam mode once in a while. Pedagogical goals include: • Fast, intensive review, like an exam but without the pass/fail stress. • Puts a premium on cooperative effort and promotes teamwork. • Serves as a morale booster, an antidote to "midterm blues." Student teams are given a chance to predict the outcome of a unique event and to test that prediction within a single fifty-minute class. The task chosen requires at least two careful measurements and subsequent analysis.

Radiation characterization report for the GPS Receiver microcontroller chip. Final report

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

Not Available

1994-06-20

The overall objective of this characterization test was to determine the sensitivity of the Motorola 68332 32-bit microcontroller to radiation induced single event upset and latch-up (SEU/SEL). The microcontroller is a key component of the GPS Receiver which will be a subsystem of the satellite required for the {open_quotes}FORTE{close_quotes} experiment. Testing was conducted at the Single Event Effects Laboratory at Brookhaven National Laboratory. The results obtained included a latch-up (SEL) threshold LET (Linear Energy Transfer) of 20 MeV-CM{sub 2}/mg and an upset (SEU) threshold LET of 5 MeV-CM{sup 2}/mg. The SEU threshold is typical of this technology, commercial 0.8{mu}m HCMOS.more » Some flow errors were observed that were not reset by the internal watchdog timer of the 68332. It is important that the Receiver design include a monitor of the device, such as an external watch-dog timer, that would initiate a reset of the program when this type of upset occurs. The SEL threshold is lower than would be expected for this 12{mu}m epi layer process and suggests the need for a strategy that would allow for a hard reset of the controller when a latch-up event occurs. Analysis of the galactic cosmic ray spectrum for the FORTE orbit was done and the results indicate a worst case latch-up rate for this device of 6.3 {times} 10{sup {minus}5} latch-ups per device day or roughly one latch-up per 43.5 device years.« less

Event-related brain potentials in memory: correlates of episodic, semantic and implicit memory.

PubMed

Wieser, Stephan; Wieser, Heinz Gregor

2003-06-01

To study cognitive evoked potentials, recorded from scalp EEG and foramen ovale electrodes, during activation of explicit and implicit memory. The subgroups of explicit memory, episodic and semantic memory, are looked at separately. A word-learning task was used, which has been shown to activate hippocampus in H(2)(15)O positron emission tomography studies. Subjects had to study and remember word pairs using different learning strategies: (i) associative word learning (AWL), which activates the episodic memory, (ii) deep single word encoding (DSWE), which activates the semantic memory, and (iii) shallow single word encoding (SSWE), which activates the implicit memory and serves as a baseline. The test included the 'remember/know' paradigm as a behavioural learning control. During the task condition, a 10-20 scalp EEG with additional electrodes in both temporal lobes regions was recorded from 11 healthy volunteers. In one patient with mesiotemporal lobe epilepsy, the EEG was recorded from bilateral foramen ovale electrodes directly from mesial temporal lobe structures. Event-related potentials (ERPs) were calculated off-line and visual and statistical analyses were made. Associative learning strategy produced the best memory performance and the best noetic awareness experience, whereas shallow single word encoding produced the worst performance and the smallest noetic awareness. Deep single word encoding performance was in between. ERPs differed according to the test condition, during both encoding and retrieval, from both the scalp EEG and the foramen ovale electrode recordings. Encoding showed significant differences between the shallow single word encoding (SSWE), which is mainly a function of graphical characteristics, and the other two strategies, deep single word (DSWE) and associative learning (AWL), in which there is a semantic processing of the meaning. ERPs generated by these two categories, which are both functions of explicit memory, differed as well, indicating the presence or the absence of associative binding. Retrieval showed a significant test effect between the word pairs learned by association (AWL) and the ones learned by encoding the words in isolation of each other (DSWE and SSWE). The comparison of the ERPs generated by autonoetic awareness ('remember') and noetic awareness ('know') exhibited a significant test effect as well. The results of behavioural data, in particular that of the 'remember/know' procedure, are evidence that the task paradigm was efficient in activating different kinds of memory. Associative word learning generated a high degree of autonoetic awareness, which is a result of the episodic memory, whereas both kinds of single word learning generated less. AWL, DSWE and SSWE resulted in different electrophysiological correlates, both for encoding as well as retrieval, indicating that different brain structures were activated in different temporal sequence.

Wide coverage biomedical event extraction using multiple partially overlapping corpora

PubMed Central

2013-01-01

Background Biomedical events are key to understanding physiological processes and disease, and wide coverage extraction is required for comprehensive automatic analysis of statements describing biomedical systems in the literature. In turn, the training and evaluation of extraction methods requires manually annotated corpora. However, as manual annotation is time-consuming and expensive, any single event-annotated corpus can only cover a limited number of semantic types. Although combined use of several such corpora could potentially allow an extraction system to achieve broad semantic coverage, there has been little research into learning from multiple corpora with partially overlapping semantic annotation scopes. Results We propose a method for learning from multiple corpora with partial semantic annotation overlap, and implement this method to improve our existing event extraction system, EventMine. An evaluation using seven event annotated corpora, including 65 event types in total, shows that learning from overlapping corpora can produce a single, corpus-independent, wide coverage extraction system that outperforms systems trained on single corpora and exceeds previously reported results on two established event extraction tasks from the BioNLP Shared Task 2011. Conclusions The proposed method allows the training of a wide-coverage, state-of-the-art event extraction system from multiple corpora with partial semantic annotation overlap. The resulting single model makes broad-coverage extraction straightforward in practice by removing the need to either select a subset of compatible corpora or semantic types, or to merge results from several models trained on different individual corpora. Multi-corpus learning also allows annotation efforts to focus on covering additional semantic types, rather than aiming for exhaustive coverage in any single annotation effort, or extending the coverage of semantic types annotated in existing corpora. PMID:23731785

Research in millimeter wave techniques

NASA Technical Reports Server (NTRS)

Mcmillan, R. W.

1978-01-01

During the past six months, efforts on this project have been devoted to: (1) continuation of construction and testing of a 6 GHz subharmonic mixer model with extension of the pumping frequency of this mixer to omega sub s/4, (2) construction of a 183 GHz subharmonic mixer based on the results of tests on this 6 GHz model, (3) ground-based radiometric measurements at 183 GHz, (4) fabrication and testing of wire grid interferometers, (5) calculations of reflected and lost power in these interferometers, and (6) calculations of the antenna temperature due to water vapor to be expected in down-looking radiometry as a function of frequency. Significant events during the past six months include: (1) Receipt of a 183 GHz single-ended fundamental mixer, (2) attainment of 6 db single sideband conversion loss with the 6 GHz subharmonic mixer model by using a 1.5 GHz (omega sub s/4) pump frequency, (3) additional ground-based radiometric measurements and (4) derivation of equations for reflection and loss for wire grid interferometers.

Efficacy of a high-resolution consultation system in gastroenterology at an Andalusian hospital center.

PubMed

Zambrana-García, José Luis; Montoro-Caba, María Isabel; Chicano-Gallardo, Maite; Monrobel-Lancho, Ana; Pérez-de-Luque, Daniel Jesús; Peña-Ojeda, José Antonio; Recio-Ramírez, José Manuel

2016-01-01

By high resolution consultation (HRC) we mean an ambulatory process of assistance fulfilled in a single day, by which treatment and diagnosis are established and recorded. To assess to which extent patients with digestive conditions may benefit from a single consultation system. A descriptive study of 179 first visit events, randomly selected as high-resolution consultations in gastroenterology. We discuss the percentage of patients who benefited from HRC and the complementary tests performed. Most common conditions included dyspepsia (16%), a family history of colon cancer (16%) and gastroesophageal reflux disease (GERD) (16%). Seventy-nine (44%) of all first visits became HRCs and 80 (45%) required a diagnostic test (100% abdominal ultrasound) that was reviewed on the same day. Performing a test on the same day significantly increased the percentage of HRCs (57% vs. 34%, p < 0.002). GERD, dyspepsia, cholelithiasis and chronic liver disease were the subjects most commonly leading to HRC. Gastroenterology consultations may largely benefit from an HRC system with only organizational changes and no additional costs.

Sensitivity booster for DOI-PET scanner by utilizing Compton scattering events between detector blocks

NASA Astrophysics Data System (ADS)

Yoshida, Eiji; Tashima, Hideaki; Yamaya, Taiga

2014-11-01

In a conventional PET scanner, coincidence events are measured with a limited energy window for detection of photoelectric events in order to reject Compton scatter events that occur in a patient, but Compton scatter events caused in detector crystals are also rejected. Scatter events within the patient causes scatter coincidences, but inter crystal scattering (ICS) events have useful information for determining an activity distribution. Some researchers have reported the feasibility of PET scanners based on a Compton camera for tracing ICS into the detector. However, these scanners require expensive semiconductor detectors for high-energy resolution. In the Anger-type block detector, single photons interacting with multiple detectors can be obtained for each interacting position and complete information can be gotten just as for photoelectric events in the single detector. ICS events in the single detector have been used to get coincidence, but single photons interacting with multiple detectors have not been used to get coincidence. In this work, we evaluated effect of sensitivity improvement using Compton kinetics in several types of DOI-PET scanners. The proposed method promises to improve the sensitivity using coincidence events of single photons interacting with multiple detectors, which are identified as the first interaction (FI). FI estimation accuracy can be improved to determine FI validity from the correlation between Compton scatter angles calculated on the coincidence line-of-response. We simulated an animal PET scanner consisting of 42 detectors. Each detector block consists of three types of scintillator crystals (LSO, GSO and GAGG). After the simulation, coincidence events are added as information for several depth-of-interaction (DOI) resolutions. From the simulation results, we concluded the proposed method promises to improve the sensitivity considerably when effective atomic number of a scintillator is low. Also, we showed that FI estimate accuracy is improved, as DOI resolution is high.

Introducing the Event Related Fixed Interval Area (ERFIA) Multilevel Technique: a Method to Analyze the Complete Epoch of Event-Related Potentials at Single Trial Level

PubMed Central

Vossen, Catherine J.; Vossen, Helen G. M.; Marcus, Marco A. E.; van Os, Jim; Lousberg, Richel

2013-01-01

In analyzing time-locked event-related potentials (ERPs), many studies have focused on specific peaks and their differences between experimental conditions. In theory, each latency point after a stimulus contains potentially meaningful information, regardless of whether it is peak-related. Based on this assumption, we introduce a new concept which allows for flexible investigation of the whole epoch and does not primarily focus on peaks and their corresponding latencies. For each trial, the entire epoch is partitioned into event-related fixed-interval areas under the curve (ERFIAs). These ERFIAs, obtained at single trial level, act as dependent variables in a multilevel random regression analysis. The ERFIA multilevel method was tested in an existing ERP dataset of 85 healthy subjects, who underwent a rating paradigm of 150 painful and non-painful somatosensory electrical stimuli. We modeled the variability of each consecutive ERFIA with a set of predictor variables among which were stimulus intensity and stimulus number. Furthermore, we corrected for latency variations of the P2 (260 ms). With respect to known relationships between stimulus intensity, habituation, and pain-related somatosensory ERP, the ERFIA method generated highly comparable results to those of commonly used methods. Notably, effects on stimulus intensity and habituation were also observed in non-peak-related latency ranges. Further, cortical processing of actual stimulus intensity depended on the intensity of the previous stimulus, which may reflect pain-memory processing. In conclusion, the ERFIA multilevel method is a promising tool that can be used to study event-related cortical processing. PMID:24224018

Point-source inversion techniques

NASA Astrophysics Data System (ADS)

Langston, Charles A.; Barker, Jeffrey S.; Pavlin, Gregory B.

1982-11-01

A variety of approaches for obtaining source parameters from waveform data using moment-tensor or dislocation point source models have been investigated and applied to long-period body and surface waves from several earthquakes. Generalized inversion techniques have been applied to data for long-period teleseismic body waves to obtain the orientation, time function and depth of the 1978 Thessaloniki, Greece, event, of the 1971 San Fernando event, and of several events associated with the 1963 induced seismicity sequence at Kariba, Africa. The generalized inversion technique and a systematic grid testing technique have also been used to place meaningful constraints on mechanisms determined from very sparse data sets; a single station with high-quality three-component waveform data is often sufficient to discriminate faulting type (e.g., strike-slip, etc.). Sparse data sets for several recent California earthquakes, for a small regional event associated with the Koyna, India, reservoir, and for several events at the Kariba reservoir have been investigated in this way. Although linearized inversion techniques using the moment-tensor model are often robust, even for sparse data sets, there are instances where the simplifying assumption of a single point source is inadequate to model the data successfully. Numerical experiments utilizing synthetic data and actual data for the 1971 San Fernando earthquake graphically demonstrate that severe problems may be encountered if source finiteness effects are ignored. These techniques are generally applicable to on-line processing of high-quality digital data, but source complexity and inadequacy of the assumed Green's functions are major problems which are yet to be fully addressed.

High rate tests of the photon detection system for the LHCb RICH Upgrade

NASA Astrophysics Data System (ADS)

Blago, M. P.; Keizer, F.

2017-12-01

The photon detection system for the LHCb RICH Upgrade consists of an array of multianode photomultiplier tubes (MaPMTs) read out by custom-built modular electronics. The behaviour of the whole chain was studied at CERN using a pulsed laser. Threshold scans were performed in order to study the MaPMT pulse-height spectra at high event rates and different photon intensities. The results show a reduction in photon detection efficiency at 900 V bias voltage, marked by a 20% decrease in the single-photon peak height, when increasing the event rate from 100 kHz to 20 MHz. This reduction was not observed at 1000 V bias voltage.

Operation of a LAr-TPC equipped with a multilayer LEM charge readout

NASA Astrophysics Data System (ADS)

Baibussinov, B.; Centro, S.; Farnese, C.; Fava, A.; Gibin, D.; Guglielmi, A.; Meng, G.; Pietropaolo, F.; Varanini, F.; Ventura, S.; Zatrimaylov, K.

2018-03-01

A novel detector for ionization signals in a single phase LAr-TPC has been experimented in the ICARINO test facility at the INFN Laboratories in Legnaro. It is based on the adoption of a multilayer Large Electron Multiplier (LEM) replacing the traditional anodic wire arrays. Cosmic muon tracks were detected allowing the measurement of energy deposition and a first determination of the signal to noise ratio. The analysis of the recorded events demonstrated the 3D reconstruction capability of this device for ionizing events in liquid Argon. The collected fraction of ionization charge is close to about 90%, with signal to noise ratio similar to that measured with more traditional wire chambers.

Single-well monitoring of protein-protein interaction and phosphorylation-dephosphorylation events.

PubMed

Arcand, Mathieu; Roby, Philippe; Bossé, Roger; Lipari, Francesco; Padrós, Jaime; Beaudet, Lucille; Marcil, Alexandre; Dahan, Sophie

2010-04-20

We combined oxygen channeling assays with two distinct chemiluminescent beads to detect simultaneously protein phosphorylation and interaction events that are usually monitored separately. This novel method was tested in the ERK1/2 MAP kinase pathway. It was first used to directly monitor dissociation of MAP kinase ERK2 from MEK1 upon phosphorylation and to evaluate MAP kinase phosphatase (MKP) selectivity and mechanism of action. In addition, MEK1 and ERK2 were probed with an ATP competitor and an allosteric MEK1 inhibitor, which generated distinct phosphorylation-interaction patterns. Simultaneous monitoring of protein-protein interactions and substrate phosphorylation can provide significant mechanistic insight into enzyme activity and small molecule action.

Evaluating average and atypical response in radiation effects simulations

NASA Astrophysics Data System (ADS)

Weller, R. A.; Sternberg, A. L.; Massengill, L. W.; Schrimpf, R. D.; Fleetwood, D. M.

2003-12-01

We examine the limits of performing single-event simulations using pre-averaged radiation events. Geant4 simulations show the necessity, for future devices, to supplement current methods with ensemble averaging of device-level responses to physically realistic radiation events. Initial Monte Carlo simulations have generated a significant number of extremal events in local energy deposition. These simulations strongly suggest that proton strikes of sufficient energy, even those that initiate purely electronic interactions, can initiate device response capable in principle of producing single event upset or microdose damage in highly scaled devices.

SEGR- and SEB-hardened structure with DSPSOI in power MOSFETs

NASA Astrophysics Data System (ADS)

Tang, Zhaohuan; Fu, Xinghua; Yang, Fashun; Tan, Kaizhou; Ma, Kui; Wu, Xue; Lin, Jiexing

2017-12-01

Single event irradiation-hardened power MOSFET is the most important device for DC/DC converter in space environment application. Single event gate rupture (SEGR) and single event burnout (SEB), which will degrade the running safety and reliability of spacecraft, are the two typical failure modes in power MOSFETs. In this paper, based on recombination mechanism of interface between oxide and silicon, a novel hardened power MOSFETs structure for SEGR and SEB is proposed. The structure comprises double stagger partial silicon-on-insulator (DSPSOI) layers. Results show that the safety operation area (SOA) of a 130 V N-channel power MOSFET in single event irradiation environment is enhanced by up to 50% when the linear-energy-transfer value of heavy ion is a constant of 98 MeV·cm2/mg in the whole incident track, and the other parameters are almost maintained at the same value. Thus this novel structure can be widely used in designing single event irradiation-hardened power MOSFETs. Project supported by the National Natural Science Foundation of China (No. 61464002), the Grand Science and Technology Special Project in Guizhou Province of China (No. [2015]6006), and the Ministry of Education Open Foundation for Semiconductor Power Device Reliability (No. 010201).

Single-Event Effects in Silicon and Silicon Carbide Power Devices

NASA Technical Reports Server (NTRS)

Lauenstein, Jean-Marie; Casey, Megan C.; LaBel, Kenneth A.; Topper, Alyson D.; Wilcox, Edward P.; Kim, Hak; Phan, Anthony M.

2014-01-01

NASA Electronics Parts and Packaging program-funded activities over the past year on single-event effects in silicon and silicon carbide power devices are presented, with focus on SiC device failure signatures.

Single-event upset in advanced PowerPC microprocessors

NASA Technical Reports Server (NTRS)

Irom, F.; Swift, G. M.; Farmanesh, F.; Millward, D. G.

2002-01-01

Proton and heavy-ion single-event upset susceptibility has been measured for the MotorolaPowerPC7400. The results show that this advanced device has low upset susceptibility, despite the scaling and design advances.

Single-Nanoparticle Photoelectrochemistry at a Nanoparticulate TiO2 -Filmed Ultramicroelectrode.

PubMed

Peng, Yue-Yi; Ma, Hui; Ma, Wei; Long, Yi-Tao; Tian, He

2018-03-26

An ultrasensitive photoelectrochemical method for achieving real-time detection of single nanoparticle collision events is presented. Using a micrometer-thick nanoparticulate TiO 2 -filmed Au ultra-microelectrode (TiO 2 @Au UME), a sub-millisecond photocurrent transient was observed for an individual N719-tagged TiO 2 (N719@TiO 2 ) nanoparticle and is due to the instantaneous collision process. Owing to a trap-limited electron diffusion process as the rate-limiting step, a random three-dimensional diffusion model was developed to simulate electron transport dynamics in TiO 2 film. The combination of theoretical simulation and high-resolution photocurrent measurement allow electron-transfer information of a single N719@TiO 2 nanoparticle to be quantified at single-molecule accuracy and the electron diffusivity and the electron-collection efficiency of TiO 2 @Au UME to be estimated. This method provides a test for studies of photoinduced electron transfer at the single-nanoparticle level. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Simulation of SEU Cross-sections using MRED under Conditions of Limited Device Information

NASA Technical Reports Server (NTRS)

Lauenstein, J. M.; Reed, R. A.; Weller, R. A.; Mendenhall, M. H.; Warren, K. M.; Pellish, J. A.; Schrimpf, R. D.; Sierawski, B. D.; Massengill, L. W.; Dodd, P. E.;

Combined array CGH plus SNP genome analyses in a single assay for optimized clinical testing

PubMed Central

Wiszniewska, Joanna; Bi, Weimin; Shaw, Chad; Stankiewicz, Pawel; Kang, Sung-Hae L; Pursley, Amber N; Lalani, Seema; Hixson, Patricia; Gambin, Tomasz; Tsai, Chun-hui; Bock, Hans-Georg; Descartes, Maria; Probst, Frank J; Scaglia, Fernando; Beaudet, Arthur L; Lupski, James R; Eng, Christine; Wai Cheung, Sau; Bacino, Carlos; Patel, Ankita

2014-01-01

In clinical diagnostics, both array comparative genomic hybridization (array CGH) and single nucleotide polymorphism (SNP) genotyping have proven to be powerful genomic technologies utilized for the evaluation of developmental delay, multiple congenital anomalies, and neuropsychiatric disorders. Differences in the ability to resolve genomic changes between these arrays may constitute an implementation challenge for clinicians: which platform (SNP vs array CGH) might best detect the underlying genetic cause for the disease in the patient? While only SNP arrays enable the detection of copy number neutral regions of absence of heterozygosity (AOH), they have limited ability to detect single-exon copy number variants (CNVs) due to the distribution of SNPs across the genome. To provide comprehensive clinical testing for both CNVs and copy-neutral AOH, we enhanced our custom-designed high-resolution oligonucleotide array that has exon-targeted coverage of 1860 genes with 60 000 SNP probes, referred to as Chromosomal Microarray Analysis – Comprehensive (CMA-COMP). Of the 3240 cases evaluated by this array, clinically significant CNVs were detected in 445 cases including 21 cases with exonic events. In addition, 162 cases (5.0%) showed at least one AOH region >10 Mb. We demonstrate that even though this array has a lower density of SNP probes than other commercially available SNP arrays, it reliably detected AOH events >10 Mb as well as exonic CNVs beyond the detection limitations of SNP genotyping. Thus, combining SNP probes and exon-targeted array CGH into one platform provides clinically useful genetic screening in an efficient manner. PMID:23695279

The Impact on Space Radiation Requirements and Effects on ASIMS

NASA Technical Reports Server (NTRS)

Barnes, C.; Johnston, A.; Swift, G.

1995-01-01

The evolution of highly miniaturized electronic and mechanical systems will be accompanied by new problems and issues regarding the radiation response of these systems in the space environment. In this paper we discuss some of the more prominent radiation problems brought about by miniaturization. For example, autonomous micro-spacecraft will require large amounts of high density memory, most likely in the form of stacked, multichip modules of DRAM's, that must tolerate the radiation environment. However, advanced DRAM's (16 to 256 Mbit) are quite susceptible to radiation, particularly single event effects, and even exhibit new radiation phenomena that were not a problem for older, less dense memory chips. Another important trend in micro-spacecraft electronics is toward the use of low-voltage microelectronic systems that consume less power. However, the reduction in operating voltage also caries with it an increased susceptibility to radiation. In the case of application specific integrated microcircuits (ASIM's), advanced devices of this type, such as high density field programmable gate arrays (FPGA's) exhibit new single event effects (SEE), such as single particle reprogramming of anti-fuse links. New advanced bipolar circuits have been shown recently to degrade more rapidly in the low dose rate space environment than in the typical laboratory total dose radiation test used to qualify such devices. Thus total dose testing of these parts is no longer an appropriately conservative measure to be used for hardness assurance. We also note that the functionality of micromechanical Si-based devices may be altered due to the radiation-induced deposition of charge in the oxide passivation layers.

Accelerated event-by-event Monte Carlo microdosimetric calculations of electrons and protons tracks on a multi-core CPU and a CUDA-enabled GPU.

PubMed

Kalantzis, Georgios; Tachibana, Hidenobu

2014-01-01

For microdosimetric calculations event-by-event Monte Carlo (MC) methods are considered the most accurate. The main shortcoming of those methods is the extensive requirement for computational time. In this work we present an event-by-event MC code of low projectile energy electron and proton tracks for accelerated microdosimetric MC simulations on a graphic processing unit (GPU). Additionally, a hybrid implementation scheme was realized by employing OpenMP and CUDA in such a way that both GPU and multi-core CPU were utilized simultaneously. The two implementation schemes have been tested and compared with the sequential single threaded MC code on the CPU. Performance comparison was established on the speed-up for a set of benchmarking cases of electron and proton tracks. A maximum speedup of 67.2 was achieved for the GPU-based MC code, while a further improvement of the speedup up to 20% was achieved for the hybrid approach. The results indicate the capability of our CPU-GPU implementation for accelerated MC microdosimetric calculations of both electron and proton tracks without loss of accuracy. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

SEE Transient Response of Crane Interpoint Single Output Point of Load DC-DC Converters

NASA Technical Reports Server (NTRS)

Sanders, Anthony B.; Chen, Dakai; Kim, Hak S.; Phan, Anthony M.

2011-01-01

This study was undertaken to determine the single event effect and transient susceptibility of the Crane Interpoint Maximum Flexible Power (MFP) Single Output Point of Load DC/DC Converters for transient interruptions in the output signal and for destructive and non destructive events induced by exposing it to a heavy ion beam..

Ophthalmic Vascular Events after Primary Unilateral Intra-arterial Chemotherapy for Retinoblastoma in Early and Recent Eras.

PubMed

Dalvin, Lauren A; Ancona-Lezama, David; Lucio-Alvarez, J Antonio; Masoomian, Babak; Jabbour, Pascal; Shields, Carol L

2018-06-16

To assess risk factors for ophthalmic vascular events after intra-arterial chemotherapy (IAC) for retinoblastoma. Retrospective cohort study. Patients who received unilateral IAC as primary treatment for retinoblastoma from January 1, 2009, to November 30, 2017, at a single center. Records were reviewed for patient demographics, tumor features, IAC parameters, and treatment-related vascular events in the early IAC era (2009-2011) compared with the recent era (2012-2017) using the t test and Fisher exact test. Change in event rates over time was assessed using Poisson regression analysis, with Spearman's rho used to test correlation. Rate of IAC-induced ophthalmic vascular events. There were 243 chemotherapy infusions in 76 eyes of 76 patients, divided into early (22 eyes, 57 infusions) and recent (54 eyes, 186 infusions) eras. Intra-arterial chemotherapy consisted of melphalan (243 infusions), topotecan (124 infusions), and carboplatin (9 infusions). A comparison (early vs. recent era) revealed fewer mean number of infusions (2.6 vs. 3.4, P = 0.02) with similar mean patient age and presenting tumor features. Event rates decreased over time (P < 0.01), with fewer ophthalmic vascular events (early era vs. recent era) in the recent era (59% vs. 9% per eye, 23% vs. 3% per infusion, P < 0.01), including peripheral retinal nonperfusion (5% vs. 2% per eye, P = 0.50), vitreous hemorrhage (9% vs. 2%, P = 0.20), subretinal hemorrhage (0% vs. 2%, P = 0.99), branch retinal vein occlusion (5% vs. 0%, P = 0.29), choroidal ischemia (14% vs. 4%, P = 0.14), and ophthalmic artery spasm/occlusion (27% vs. 0%, P < 0.01). Events did not correlate to patient age (P = 0.75), tumor diameter (P = 0.32), tumor thickness (P = 0.59), or cumulative dosage of melphalan (P = 0.13) or topotecan (P = 0.59). There were no IAC-induced vascular events in 72 infusions of 21 consecutively treated eyes in 2016 to 2017. Ophthalmic vascular events after IAC have decreased from the early era (2009-2011) through the current era (2012-2017) at this center. Experience performing this highly specialized procedure could be an important factor predicting IAC-related vascular events. Copyright © 2018 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Analysis and visualization of single-trial event-related potentials

NASA Technical Reports Server (NTRS)

Jung, T. P.; Makeig, S.; Westerfield, M.; Townsend, J.; Courchesne, E.; Sejnowski, T. J.

2001-01-01

In this study, a linear decomposition technique, independent component analysis (ICA), is applied to single-trial multichannel EEG data from event-related potential (ERP) experiments. Spatial filters derived by ICA blindly separate the input data into a sum of temporally independent and spatially fixed components arising from distinct or overlapping brain or extra-brain sources. Both the data and their decomposition are displayed using a new visualization tool, the "ERP image," that can clearly characterize single-trial variations in the amplitudes and latencies of evoked responses, particularly when sorted by a relevant behavioral or physiological variable. These tools were used to analyze data from a visual selective attention experiment on 28 control subjects plus 22 neurological patients whose EEG records were heavily contaminated with blink and other eye-movement artifacts. Results show that ICA can separate artifactual, stimulus-locked, response-locked, and non-event-related background EEG activities into separate components, a taxonomy not obtained from conventional signal averaging approaches. This method allows: (1) removal of pervasive artifacts of all types from single-trial EEG records, (2) identification and segregation of stimulus- and response-locked EEG components, (3) examination of differences in single-trial responses, and (4) separation of temporally distinct but spatially overlapping EEG oscillatory activities with distinct relationships to task events. The proposed methods also allow the interaction between ERPs and the ongoing EEG to be investigated directly. We studied the between-subject component stability of ICA decomposition of single-trial EEG epochs by clustering components with similar scalp maps and activation power spectra. Components accounting for blinks, eye movements, temporal muscle activity, event-related potentials, and event-modulated alpha activities were largely replicated across subjects. Applying ICA and ERP image visualization to the analysis of sets of single trials from event-related EEG (or MEG) experiments can increase the information available from ERP (or ERF) data. Copyright 2001 Wiley-Liss, Inc.

Intermittency in a single event

NASA Astrophysics Data System (ADS)

Bialas, A.; Ziaja, B.

1996-02-01

The possibility to study intermittency in a single event of high multiplicity is investigated in the framework of the α-model. It is found that, for cascade long enough, the dispersion of intermittency exponents obtained from individual events is fairly small. This fact opens the possibility to study the distribution of the intermittency parameters characterizing the cascades seen (by observing intermittency) in particle spectra.

Calculation of cosmic ray induced single event upsets: Program CRUP (Cosmic Ray Upset Program)

NASA Astrophysics Data System (ADS)

Shapiro, P.

1983-09-01

This report documents PROGRAM CRUP, COSMIC RAY UPSET PROGRAM. The computer program calculates cosmic ray induced single-event error rates in microelectronic circuits exposed to several representative cosmic-ray environments.

FPGA-based gating and logic for multichannel single photon counting

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

Pooser, Raphael C; Earl, Dennis Duncan; Evans, Philip G

2012-01-01

We present results characterizing multichannel InGaAs single photon detectors utilizing gated passive quenching circuits (GPQC), self-differencing techniques, and field programmable gate array (FPGA)-based logic for both diode gating and coincidence counting. Utilizing FPGAs for the diode gating frontend and the logic counting backend has the advantage of low cost compared to custom built logic circuits and current off-the-shelf detector technology. Further, FPGA logic counters have been shown to work well in quantum key distribution (QKD) test beds. Our setup combines multiple independent detector channels in a reconfigurable manner via an FPGA backend and post processing in order to perform coincidencemore » measurements between any two or more detector channels simultaneously. Using this method, states from a multi-photon polarization entangled source are detected and characterized via coincidence counting on the FPGA. Photons detection events are also processed by the quantum information toolkit for application testing (QITKAT)« less

Distributional Tests for Gravitational Waves from Core-Collapse Supernovae

NASA Astrophysics Data System (ADS)

Szczepanczyk, Marek; LIGO Collaboration

2017-01-01

Core-Collapse Supernovae (CCSN) are spectacular and violent deaths of massive stars. CCSN are some of the most interesting candidates for producing gravitational-waves (GW) transients. Current published results focus on methodologies to detect single GW unmodelled transients. The advantages of these tests are that they do not require a background for which we have an analytical model. Examples of non-parametric tests that will be compared are Kolmogorov-Smirnov, Mann-Whitney, chi squared, and asymmetric chi squared. I will present methodological results using publicly released LIGO-S6 data recolored to the design sensitivity of Advanced LIGO and that will be time lagged between interferometers sites so that the resulting coincident events are not GW.

CREME96 and Related Error Rate Prediction Methods

NASA Technical Reports Server (NTRS)

Adams, James H., Jr.

2012-01-01

Predicting the rate of occurrence of single event effects (SEEs) in space requires knowledge of the radiation environment and the response of electronic devices to that environment. Several analytical models have been developed over the past 36 years to predict SEE rates. The first error rate calculations were performed by Binder, Smith and Holman. Bradford and Pickel and Blandford, in their CRIER (Cosmic-Ray-Induced-Error-Rate) analysis code introduced the basic Rectangular ParallelePiped (RPP) method for error rate calculations. For the radiation environment at the part, both made use of the Cosmic Ray LET (Linear Energy Transfer) spectra calculated by Heinrich for various absorber Depths. A more detailed model for the space radiation environment within spacecraft was developed by Adams and co-workers. This model, together with a reformulation of the RPP method published by Pickel and Blandford, was used to create the CR ME (Cosmic Ray Effects on Micro-Electronics) code. About the same time Shapiro wrote the CRUP (Cosmic Ray Upset Program) based on the RPP method published by Bradford. It was the first code to specifically take into account charge collection from outside the depletion region due to deformation of the electric field caused by the incident cosmic ray. Other early rate prediction methods and codes include the Single Event Figure of Merit, NOVICE, the Space Radiation code and the effective flux method of Binder which is the basis of the SEFA (Scott Effective Flux Approximation) model. By the early 1990s it was becoming clear that CREME and the other early models needed Revision. This revision, CREME96, was completed and released as a WWW-based tool, one of the first of its kind. The revisions in CREME96 included improved environmental models and improved models for calculating single event effects. The need for a revision of CREME also stimulated the development of the CHIME (CRRES/SPACERAD Heavy Ion Model of the Environment) and MACREE (Modeling and Analysis of Cosmic Ray Effects in Electronics). The Single Event Figure of Merit method was also revised to use the solar minimum galactic cosmic ray spectrum and extended to circular orbits down to 200 km at any inclination. More recently a series of commercial codes was developed by TRAD (Test & Radiations) which includes the OMERE code which calculates single event effects. There are other error rate prediction methods which use Monte Carlo techniques. In this chapter the analytic methods for estimating the environment within spacecraft will be discussed.

Probing the SEB Sensitive Depth of a Power MOSFET Using a Two-Photon Absorption Laser Method

NASA Technical Reports Server (NTRS)

Lauenstein, Jean-Marie; Liu, Sandra; Titus, Jeffrey L.; McMorrow, Dale; Casey, Megan C.; Buchner, Stephen P.; Warner, Jeffrey; Phan, Anthony M.; Topper, Alyson D.; Kim, Hak S.;

Methodologies for the Statistical Analysis of Memory Response to Radiation

NASA Astrophysics Data System (ADS)

Bosser, Alexandre L.; Gupta, Viyas; Tsiligiannis, Georgios; Frost, Christopher D.; Zadeh, Ali; Jaatinen, Jukka; Javanainen, Arto; Puchner, Helmut; Saigné, Frédéric; Virtanen, Ari; Wrobel, Frédéric; Dilillo, Luigi

2016-08-01

Methodologies are proposed for in-depth statistical analysis of Single Event Upset data. The motivation for using these methodologies is to obtain precise information on the intrinsic defects and weaknesses of the tested devices, and to gain insight on their failure mechanisms, at no additional cost. The case study is a 65 nm SRAM irradiated with neutrons, protons and heavy ions. This publication is an extended version of a previous study [1].

Initial Single Event Effects Testing of the Xilinx Virtex-4 Field Programmable Gate Array

NASA Technical Reports Server (NTRS)

Allen, Gregory R.; Swift, Gary M.; Carmichael, C.; Tseng, C.

2007-01-01

We present initial results for the thin epitaxial Xilinx Virtex-4 Fie ld Programmable Gate Array (FPGA), and compare to previous results ob tained for the Virtex-II and Virtex-II Pro. The data presented was a cquired through a consortium based effort with the common goal of pr oviding the space community with data and mitigation methods for the use of Xilinx FPGAs in space.

Multipulsed dynamic moire interferometer

DOEpatents

Deason, Vance A.

1991-01-01

An improved dynamic moire interferometer comprised of a lasing medium providing a plurality of beams of coherent light, a multiple q-switch producing multiple trains of 100,000 or more pulses per second, a combining means collimating multiple trains of pulses into substantially a single train and directing beams to specimen gratings affixed to a test material, and a controller, triggering and sequencing the emission of the pulses with the occurrence and recording of a dynamic loading event.

Multiple acousto-optic q-switch

DOEpatents

Deason, Vance A.

1993-01-01

An improved dynamic moire interferometer comprised of a lasing medium providing a plurality of beams of coherent light, a multiple q-switch producing multiple trains of 100,000 or more pulses per second, a combining means collimating multiple trains of pulses into substantially a single train and directing beams to specimen gratings affixed to a test material, and a controller, triggering and sequencing the emission of the pulses with the occurrence and recording of a dynamic loading event.

Multiple acousto-optic q-switch

DOEpatents

Deason, Vance A.

1993-12-07

An improved dynamic moire interferometer comprised of a lasing medium providing a plurality of beams of coherent light, a multiple q-switch producing multiple trains of 100,000 or more pulses per second, a combining means collimating multiple trains of pulses into substantially a single train and directing beams to specimen gratings affixed to a test material, and a controller, triggering and sequencing the emission of the pulses with the occurrence and recording of a dynamic loading event.

Estimation of full moment tensors, including uncertainties, for earthquakes, volcanic events, and nuclear explosions

NASA Astrophysics Data System (ADS)

Alvizuri, Celso; Silwal, Vipul; Krischer, Lion; Tape, Carl

2017-04-01

A seismic moment tensor is a 3 × 3 symmetric matrix that provides a compact representation of seismic events within Earth's crust. We develop an algorithm to estimate moment tensors and their uncertainties from observed seismic data. For a given event, the algorithm performs a grid search over the six-dimensional space of moment tensors by generating synthetic waveforms at each grid point and then evaluating a misfit function between the observed and synthetic waveforms. 'The' moment tensor M for the event is then the moment tensor with minimum misfit. To describe the uncertainty associated with M, we first convert the misfit function to a probability function. The uncertainty, or rather the confidence, is then given by the 'confidence curve' P(V ), where P(V ) is the probability that the true moment tensor for the event lies within the neighborhood of M that has fractional volume V . The area under the confidence curve provides a single, abbreviated 'confidence parameter' for M. We apply the method to data from events in different regions and tectonic settings: small (Mw < 2.5) events at Uturuncu volcano in Bolivia, moderate (Mw > 4) earthquakes in the southern Alaska subduction zone, and natural and man-made events at the Nevada Test Site. Moment tensor uncertainties allow us to better discriminate among moment tensor source types and to assign physical processes to the events.

Real-time envelope cross-correlation detector: application to induced seismicity in the Insheim and Landau deep geothermal reservoirs

NASA Astrophysics Data System (ADS)

Vasterling, Margarete; Wegler, Ulrich; Becker, Jan; Brüstle, Andrea; Bischoff, Monika

2017-01-01

We develop and test a real-time envelope cross-correlation detector for use in seismic response plans to mitigate hazard of induced seismicity. The incoming seismological data are cross-correlated in real-time with a set of previously recorded master events. For robustness against small changes in the earthquake source locations or in the focal mechanisms we cross-correlate the envelopes of the seismograms rather than the seismograms themselves. Two sequenced detection conditions are implemented: After passing a single trace cross-correlation condition, a network cross-correlation is calculated taking amplitude ratios between stations into account. Besides detecting the earthquake and assigning it to the respective reservoir, real-time magnitudes are important for seismic response plans. We estimate the magnitudes of induced microseismicity using the relative amplitudes between master event and detected event. The real-time detector is implemented as a SeisComP3 module. We carry out offline and online performance tests using seismic monitoring data of the Insheim and Landau geothermal power plants (Upper Rhine Graben, Germany), also including blasts from a nearby quarry. The comparison of the automatic real-time catalogue with a manually processed catalogue shows, that with the implemented parameters events are always correctly assigned to the respective reservoir (4 km distance between reservoirs) or the quarry (8 km and 10 km distance, respectively, from the reservoirs). The real-time catalogue achieves a magnitude of completeness around 0.0. Four per cent of the events assigned to the Insheim reservoir and zero per cent of the Landau events are misdetections. All wrong detections are local tectonic events, whereas none are caused by seismic noise.

Adverse Events in the Long-Term Follow-Up of Patients Treated With Samarium Sm 153 Lexidronam for Osseous Metastases

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

Paravati, Anthony J., E-mail: Anthony.J.Paravati@dartmouth.edu; Russo, Andrea L.; Aitken, Candice

Purpose: To investigate adverse events after samarium Sm 153 lexidronam and the effect of pre- and post-samarium Sm 153 lexidronam external beam radiation therapy (EBRT) and/or chemotherapy on myelosuppression in patients who received samarium Sm 153 lexidronam for osseous metastases. Methods and Materials: We performed a single-institution retrospective review of 139 patients treated with samarium Sm 153 lexidronam between November 1997 and February 2008. New-onset adverse events after samarium Sm 153 lexidronam were reported. The effect of samarium Sm 153 lexidronam on platelet and peripheral white blood cell counts and the duration of myelosuppression after samarium Sm 153 lexidronam plusmore » EBRT and/or chemotherapy were calculated. Differences in the prevalence of adverse events among patients with varying treatment histories were evaluated with the Pearson chi-square test. Results: Hematologic follow-up was available for 103 patients. Chemotherapy and/or EBRT had no effect on the magnitude or duration of myelosuppression. The most common nonhematologic adverse events were acute lower extremity edema (n = 27) and acute and transient neuropathy (n = 29). Patients treated with chemotherapy after samarium Sm 153 lexidronam had a higher prevalence of lower extremity edema (9 of 18 [50%]) than those who were not treated with chemotherapy after samarium Sm 153 lexidronam (18 of 85 [21.2%]) (p = 0.01, chi-square test). No adverse events were correlated with EBRT. Conclusions: Our observation of new-onset, acute and transient edema and neuropathy after samarium Sm 153 lexidronam and of a relationship between edema and post-samarium Sm 153 lexidronam chemotherapy suggests the need for re-examination of patients in past series or for a prospective investigation with nonhematologic adverse events as a primary endpoint.« less

Testicular histology and germ cell cytology during spermatogenesis in the Mississippi map turtle, Graptemys pseudogeographica kohnii, from Northeast Arkansas.

PubMed

Lancaster, Kelsey; Trauth, Stanley E; Gribbins, Kevin M

2014-01-01

The testicular histology and cytology of spermatogenesis in Graptemys pseudogeographica kohnii were examined using specimens collected between July 1996 and May 2004 from counties in northeastern Arkansas. A histological examination of the testes and germ cell cytology indicates a postnuptial testicular cycle of spermatogenesis and a major fall spermiation event. The majority of the germ cell populations in May and June specimens are represented by resting spermatogonia, type A spermatogonia, type B spermatogonia, pre-leptotene spermatocytes, and numerous Sertoli cell nuclei near the basement membrane. The start of proliferation is evident as spermatogonia in metaphase are present near the basal lamina and many of these germ cells have entered meiosis in June seminiferous tubules. Major spermatogenic events occur in the June and July specimens and result in an increased height of the seminiferous epithelium and increased diameter of the seminiferous tubules. The germ cell population during this time is represented by spermatogonia (type A, B, and resting), hypertrophic cells, large populations of early primary spermatocytes, and early round spermatids. By September, the major germ cell population has progressed past meiosis with abundant round and early elongating spermatids dominating the seminiferous epithelium. October seminiferous epithelia are marked by a decreas in height and mature spermatozoa fill the luminal space. Round and elongating spermatids constitute the largest portion of the germ cell population. Following the spermiation event, the testes enter a period of quiescence that lasts till the next spermatogenic cycle, which begins in the subsequent spring. Based on the cytological development of the seminiferous tubules revealed by our study, Graptemys pseudogeographica kohnii demonstrates a temporal germ cell development strategy similar to other temperate reptiles. A single major generation of germ cells progresses through spermatogenesis each year resulting in a single spermiation event with sperm stored within the epididymis until the next spring mating season.

Testicular histology and germ cell cytology during spermatogenesis in the Mississippi map turtle, Graptemys pseudogeographica kohnii, from Northeast Arkansas

PubMed Central

Lancaster, Kelsey; Trauth, Stanley E; Gribbins, Kevin M

2014-01-01

The testicular histology and cytology of spermatogenesis in Graptemys pseudogeographica kohnii were examined using specimens collected between July 1996 and May 2004 from counties in northeastern Arkansas. A histological examination of the testes and germ cell cytology indicates a postnuptial testicular cycle of spermatogenesis and a major fall spermiation event. The majority of the germ cell populations in May and June specimens are represented by resting spermatogonia, type A spermatogonia, type B spermatogonia, pre-leptotene spermatocytes, and numerous Sertoli cell nuclei near the basement membrane. The start of proliferation is evident as spermatogonia in metaphase are present near the basal lamina and many of these germ cells have entered meiosis in June seminiferous tubules. Major spermatogenic events occur in the June and July specimens and result in an increased height of the seminiferous epithelium and increased diameter of the seminiferous tubules. The germ cell population during this time is represented by spermatogonia (type A, B, and resting), hypertrophic cells, large populations of early primary spermatocytes, and early round spermatids. By September, the major germ cell population has progressed past meiosis with abundant round and early elongating spermatids dominating the seminiferous epithelium. October seminiferous epithelia are marked by a decreas in height and mature spermatozoa fill the luminal space. Round and elongating spermatids constitute the largest portion of the germ cell population. Following the spermiation event, the testes enter a period of quiescence that lasts till the next spermatogenic cycle, which begins in the subsequent spring. Based on the cytological development of the seminiferous tubules revealed by our study, Graptemys pseudogeographica kohnii demonstrates a temporal germ cell development strategy similar to other temperate reptiles. A single major generation of germ cells progresses through spermatogenesis each year resulting in a single spermiation event with sperm stored within the epididymis until the next spring mating season. PMID:26413408

Safety, pharmacokinetics, and pharmacodynamics of S-(-)-pantoprazole sodium injections after single and multiple intravenous doses in healthy Chinese subjects.

PubMed

Jiao, Hui-Wen; Sun, Lu-Ning; Li, Yue-Qi; Yu, Lei; Zhang, Hong-Wen; Wang, Mei-Feng; Yu, Li-Yuan; Yuan, Zi-Qing-Yun; Xie, Li-Jun; Chen, Juan; Meng, Ling; Zhang, Xue-Hui; Wang, Yong-Qing

2018-03-01

The objective of this study was to evaluate the safety, pharmacokinetics, and pharmacodynamics of S-(-)-pantoprazole (PPZ) sodium injections following single and multiple intravenous doses in healthy Chinese subjects. The dosage groups were set as followed: 20 mg of single and multiple intravenous administration of S-(-)-PPZ, 40 mg of single and multiple intravenous administration of S-(-)-PPZ or pantoprazole, and 80 mg of single dosage group of S-(-)-PPZ. Subjects were sampled for pharmacokinetic analysis and were monitored for 24-h intragastric pH prior to and 48-h intragastric pH after administration for the pharmacodynamic study. The pharmacokinetic and pharmacodynamic parameters were compared between S-(-)-PPZ and PPZ. Safety was evaluated on the basis of adverse events, vital signs, laboratory tests, and physical examination. All adverse events were mild and of limited duration. Maximum plasma concentration and area under the concentration-time curve for S-(-)-PPZ were dose proportional over the range of 20-80 mg following a single intravenous administration. Elimination rate constant and half-life observed statistical difference from a single dose to multiple doses in 40 mg of S-(-)-PPZ groups. After administration of a single dose, the mean 24-h intragastric pH value was observed higher in 80-mg group than in 40- and 20-mg groups. Slightly increase of intragastric pH was found after a single dose of 40 mg S-(-)-PPZ than 40 mg PPZ; however, the differences were not statistically significant. Twice daily of 40 mg S-(-)-PPZ sodium injections is effective in achieving satisfying acid inhibition. Compared with plasma R-(+)-PPZ levels, most subjects presented more potent and prolonged suppression of gastric acid of S-(-)-PPZ, while a few subjects showed faster metabolic rate of S-(-)-PPZ in vivo.

Performance Assessment of the Optical Transient Detector and Lightning Imaging Sensor. Part 2; Clustering Algorithm

NASA Technical Reports Server (NTRS)

Mach, Douglas M.; Christian, Hugh J.; Blakeslee, Richard; Boccippio, Dennis J.; Goodman, Steve J.; Boeck, William

2006-01-01

We describe the clustering algorithm used by the Lightning Imaging Sensor (LIS) and the Optical Transient Detector (OTD) for combining the lightning pulse data into events, groups, flashes, and areas. Events are single pixels that exceed the LIS/OTD background level during a single frame (2 ms). Groups are clusters of events that occur within the same frame and in adjacent pixels. Flashes are clusters of groups that occur within 330 ms and either 5.5 km (for LIS) or 16.5 km (for OTD) of each other. Areas are clusters of flashes that occur within 16.5 km of each other. Many investigators are utilizing the LIS/OTD flash data; therefore, we test how variations in the algorithms for the event group and group-flash clustering affect the flash count for a subset of the LIS data. We divided the subset into areas with low (1-3), medium (4-15), high (16-63), and very high (64+) flashes to see how changes in the clustering parameters affect the flash rates in these different sizes of areas. We found that as long as the cluster parameters are within about a factor of two of the current values, the flash counts do not change by more than about 20%. Therefore, the flash clustering algorithm used by the LIS and OTD sensors create flash rates that are relatively insensitive to reasonable variations in the clustering algorithms.

V-FASTR: THE VLBA FAST RADIO TRANSIENTS EXPERIMENT

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

Wayth, Randall B.; Tingay, Steven J.; Brisken, Walter F.

2011-07-10

Recent discoveries of dispersed, non-periodic impulsive radio signals with single-dish radio telescopes have sparked significant interest in exploring the relatively uncharted space of fast transient radio signals. Here we describe V-FASTR, an experiment to perform a blind search for fast transient radio signals using the Very Long Baseline Array (VLBA). The experiment runs entirely in a commensal mode, alongside normal VLBA observations and operations. It is made possible by the features and flexibility of the DiFX software correlator that is used to process VLBA data. Using the VLBA for this type of experiment offers significant advantages over single-dish experiments, includingmore » a larger field of view, the ability to easily distinguish local radio-frequency interference from real signals, and the possibility to localize detected events on the sky to milliarcsecond accuracy. We describe our software pipeline, which accepts short integration ({approx} ms) spectrometer data from each antenna in real time during correlation and performs an incoherent dedispersion separately for each antenna, over a range of trial dispersion measures. The dedispersed data are processed by a sophisticated detector and candidate events are recorded. At the end of the correlation, small snippets of the raw data at the time of the events are stored for further analysis. We present the results of our event detection pipeline from some test observations of the pulsars B0329+54 and B0531+21 (the Crab pulsar).« less

A Single-Unit Design Structure and Gender Differences in the Swimming World Championships

PubMed Central

Pushkar, Svetlana; Issurin, Vladimir B.; Verbitsky, Oleg

2014-01-01

Four 50 meter male/female finals - the freestyle, butterfly, breaststroke, and backstroke - swum during individual events at the Swimming World Championships (SWCs) can be defined in four clusters. The aim of the present study was to use a single-unit design structure, in which the swimmer was defined at only one scale, to evaluate gender differences in start reaction times among elite swimmers in 50 m events. The top six male and female swimmers in the finals of four swimming stroke final events in six SWCs were analyzed. An unpaired t-test was used. The p-values were evaluated using Neo-Fisherian significance assessments (Hurlbert and Lombardi, 2012). For the freestyle, gender differences in the start reaction times were positively identified for five of the six SWCs. For the backstroke, gender differences in the start reaction times could be dismissed for five of the six SWCs. For both the butterfly and breaststroke, gender differences in the start reaction times yielded inconsistent statistical differences. Pooling all swimmers together (df = 286) showed that an overall gender difference in the start reaction times could be positively identified: p = 0.00004. The contrast between the gender differences in start reaction times between the freestyle and backstroke may be associated with different types of gender adaptations to swimming performances. When the natural groupings of swimming stroke final events were ignored, sacrificial pseudoreplication occurred, which may lead to erroneous statistical differences. PMID:25414754

Fecal-indicator bacteria in the Allegheny, Monongahela, and Ohio Rivers, near Pittsburgh, Pennsylvania, July-September 2001

USGS Publications Warehouse

Fulton, John W.; Buckwalter, Theodore F.

2004-01-01

This report presents the results of a study by the Allegheny County Health Department (ACHD) and the U.S. Geological Survey (USGS) to determine the concentrations of fecal-indicator bacteria in the Allegheny, Monongahela, and Ohio Rivers (Three Rivers) in Allegheny County, Pittsburgh, Pa. Water-quality samples and river-discharge measurements were collected from July to September 2001 during dry- (72-hour dry antecedent period), mixed-, and wet-weather (48-hour dry antecedent period and at least 0.3 inch of rain in a 6-hour period) conditions at five sampling sites on the Three Rivers in Allegheny County. Water samples were collected weekly to establish baseline conditions and during successive days after three wet-weather events. Water samples were analyzed for fecal-indicator organisms including fecal-coliform (FC) bacteria, Escherichia coli (E. coli), and enterococci bacteria. Water samples were collected by the USGS and analyzed by the ACHD Laboratory. At each site, left-bank and right-bank surface-water samples were collected in addition to a composite sample (discharge-weighted sample representative of the channel cross section as a whole) at each site. Fecal-indicator bacteria reported in bank and composite samples were used to evaluate the distribution and mixing of bacteria-source streams in receiving waters such as the Three Rivers. Single-event concentrations of enterococci, E. coli, and FC during dry-weather events were greater than State and Federal water-quality standards (WQS) in 11, 28, and 28 percent of the samples, respectively; during mixed-weather events, concentrations of fecal-indicator bacteria were greater than WQS in 28, 37, and 43 percent of the samples, respectively; and during wet-weather events, concentrations of fecal-indicator bacteria were greater than WQS in 56, 71, and 81 percent of samples, respectively. Single-event, wet-weather concentrations exceeded those during dry-weather events for all sites except the Allegheny River at Oakmont. For this site, dilution during wet-weather events or the lack of source streams upgradient of the site may have caused this anomaly. Additionally, single-event concentrations of E. coli and FC frequently exceeded the WQS reported during wet-weather events. It is difficult to establish a short-term trend in fecal-indicator bacteria concentrations as a function of time after a wet-weather event due to factors including the spatial variability of sources contributing fecal material, dry-weather discharges, resuspension of bottom sediments, and flow augmentation from reservoirs. Relative to E. coli and enterococci, FC concentrations appeared to decrease with time, which may be attributed to the greater die-off rate for FC bacteria. Fecal-indicator bacteria concentrations at a site are dependent on the spatial distribution of point sources upstream of the station, the time-of-travel, rate of decay, and the degree of mixing and resuspension. Therefore, it is difficult to evaluate whether the left, right, and composite concentrations reported at a particular site are significantly different. To evaluate the significance of the fecal-indicator bacteria concentrations and turbidity reported in grab and composite samples during dry-, mixed-, and wet-weather events, data sets were evaluated using Wilcoxon rank sum tests. Tests were conducted using the fecal-indicator bacteria colonies and turbidity reported for each station for a given weather event. For example, fecal coliform counts reported in the left-bank sample were compared against the right-bank and composite samples, respectively, for the Ohio River at Sewickley site during dry-, mixed-, and wet-weather events. The statistical analyses suggest that, depending on the sampling site, the fecal-bacteria concentrations measured at selected locations vary spatially within a channel (left bank compared to right, right bank compared to composite). The most significant differences occurred between feca

Network hydraulics inclusion in water quality event detection using multiple sensor stations data.

PubMed

Oliker, Nurit; Ostfeld, Avi

2015-09-01

Event detection is one of the current most challenging topics in water distribution systems analysis: how regular on-line hydraulic (e.g., pressure, flow) and water quality (e.g., pH, residual chlorine, turbidity) measurements at different network locations can be efficiently utilized to detect water quality contamination events. This study describes an integrated event detection model which combines multiple sensor stations data with network hydraulics. To date event detection modelling is likely limited to single sensor station location and dataset. Single sensor station models are detached from network hydraulics insights and as a result might be significantly exposed to false positive alarms. This work is aimed at decreasing this limitation through integrating local and spatial hydraulic data understanding into an event detection model. The spatial analysis complements the local event detection effort through discovering events with lower signatures by exploring the sensors mutual hydraulic influences. The unique contribution of this study is in incorporating hydraulic simulation information into the overall event detection process of spatially distributed sensors. The methodology is demonstrated on two example applications using base runs and sensitivity analyses. Results show a clear advantage of the suggested model over single-sensor event detection schemes. Copyright © 2015 Elsevier Ltd. All rights reserved.

Single-event upset in advanced commercial power PC microprocessors

NASA Technical Reports Server (NTRS)

Irom, F.; Farmanesh, F.; Swift, G. M.; Johnston, A. H.

2003-01-01

Single-event upset from heavy ions in measured for advanced commercial microprocessors, comparing upset sensitivity in registers and d-cache for several generations of devices. Multiple-bit upsets and asymmetry in registers upset cross sections are also discussed.

Bioequivalence and pharmacokinetic evaluation of two formulations of risperidone 2 mg : an open-label, single-dose, fasting, randomized-sequence, two-way crossover study in healthy male Chinese volunteers.

PubMed

Liu, Yun; Zhang, Meng-qi; Jia, Jing-ying; Liu, Yan-mei; Liu, Gang-yi; Li, Shui-jun; Wang, Wei; Weng, Li-ping; Yu, Chen

2013-03-01

Risperidone is a benzisoxazole derivate and is effective in the treatment of schizophrenia and other psychiatric illnesses in adults and children. Although there are a few reports in the literature regarding the pharmacokinetic characteristics of risperidone, insufficient data on its pharmacokinetic properties in a Chinese population are available. To meet the requirements for marketing a new generic product, this study was designed to compare the pharmacokinetic properties and bioequivalence of two 2 mg tablet formulations of risperidone: a newly developed generic formulation (test) and a branded formulation (reference) in healthy adult male Chinese volunteers. A single-dose, open-label, randomized-sequence, 2 × 2 crossover study was conducted in fasted healthy male Chinese volunteers. Eligible participants were randomly assigned in a 1:1 ratio to receive 1 tablet (2 mg each) of the test formulation (Risperidone tablet; Dr. Reddy's Laboratories Ltd., Hyderabad, India) or the reference formulation (Risperdal(®) tablet; Xian-Janssen Pharmaceutical Ltd., Xi-an, China), followed by a 2-week washout period and subsequent administration of the alternate formulation. The study drugs were administered after a 10-hour overnight fast. Plasma samples were collected over 96 hours. Plasma concentrations of the parent drug, risperidone, and its active metabolite, 9-hydroxy-risperidone, were analyzed by a liquid chromatography-tandem mass spectrometry method. The formulations would be considered bioequivalent if the 90% confidence intervals (CIs) of the natural log-transformed values were within the predetermined 80-125% equivalence range for the maximum plasma drug concentration (Cmax) and the area under the plasma concentration-time curve (AUC), in accordance with guidelines issued by the US Food and Drug Administration. Assessment of tolerability was based on recording of adverse events (AEs), monitoring of vital signs, electrocardiograms, and laboratory tests at baseline and at completion of the study. A total of 24 healthy male Chinese volunteers (mean age 22.9 years [standard deviation (SD) 2.7, range 19.2-27.1]; weight 63.2 kg [SD 7.0, range 52.0-78.0]; and height 171.3 cm [SD 6.1, range 162.0-187.0]) were enrolled, and all completed the study. For the parent drug, risperidone, the 90% CIs of the relative values (test vs. reference) of the Cmax, AUC from time zero to time t (AUCt), and AUC from time zero to infinity (AUC∞) were 97.0-124.0%, 92.7-115.1%, and 92.8-114.2%, respectively. For the active metabolite, 9-hydroxy-risperidone, the values were 104.4-117.7%, 101.0-113.7%, and 100.4-113.4%, respectively. The two formulations met the predetermined criteria for bioequivalence. A total of 73 AEs were observed in 24 subjects during the study. The most common AE was sedation (48 events), followed by nasal reactions (14 events), postural hypotension (3 events), hypertriglyceridemia (2 events), dizziness (4 events), nausea (1 event), and anorexia (1 event). Their severity was as follows: 16 were mild, 57 were moderate, and none were severe. The majority of the AEs were considered to be related (48 events) or probably related (23 events) to the study medication. No clinically significant abnormalities on physical examination, vital sign measurements, or electrocardiographic recordings were reported. No serious AEs were reported. The data from this study in healthy adult male Chinese subjects suggest that the test formulation met the regulatory criteria for bioequivalence to the reference formulation, on the basis of the rate and extent of absorption. Both formulations were well tolerated.

Applying a Hidden Markov Model-Based Event Detection and Classification Algorithm to Apollo Lunar Seismic Data

NASA Astrophysics Data System (ADS)

Knapmeyer-Endrun, B.; Hammer, C.

2014-12-01

The seismometers that the Apollo astronauts deployed on the Moon provide the only recordings of seismic events from any extra-terrestrial body so far. These lunar events are significantly different from ones recorded on Earth, in terms of both signal shape and source processes. Thus they are a valuable test case for any experiment in planetary seismology. In this study, we analyze Apollo 16 data with a single-station event detection and classification algorithm in view of NASA's upcoming InSight mission to Mars. InSight, scheduled for launch in early 2016, has the goal to investigate Mars' internal structure by deploying a seismometer on its surface. As the mission does not feature any orbiter, continuous data will be relayed to Earth at a reduced rate. Full range data will only be available by requesting specific time-windows within a few days after the receipt of the original transmission. We apply a recently introduced algorithm based on hidden Markov models that requires only a single example waveform of each event class for training appropriate models. After constructing the prototypes we detect and classify impacts and deep and shallow moonquakes. Initial results for 1972 (year of station installation with 8 months of data) indicate a high detection rate of over 95% for impacts, of which more than 80% are classified correctly. Deep moonquakes, which occur in large amounts, but often show only very weak signals, are detected with less certainty (~70%). As there is only one weak shallow moonquake covered, results for this event class are not statistically significant. Daily adjustments of the background noise model help to reduce false alarms, which are mainly erroneous deep moonquake detections, by about 25%. The algorithm enables us to classify events that were previously listed in the catalog without classification, and, through the combined use of long period and short period data, identify some unlisted local impacts as well as at least two yet unreported deep moonquakes.

A test of multiple correlation temporal window characteristic of non-Markov processes

NASA Astrophysics Data System (ADS)

Arecchi, F. T.; Farini, A.; Megna, N.

2016-03-01

We introduce a sensitive test of memory effects in successive events. The test consists of a combination K of binary correlations at successive times. K decays monotonically from K = 1 for uncorrelated events as a Markov process. For a monotonic memory fading, K<1 always. Here we report evidence of a K>1 temporal window in cognitive tasks consisting of the visual identification of the front face of the Necker cube after a previous presentation of the same. We speculate that memory effects provide a temporal window with K>1 and this experiment could be a possible first step towards a better comprehension of this phenomenon. The K>1 behaviour is maximal at an inter-measurement time τ around 2s with inter-subject differences. The K>1 persists over a time window of 1s around τ; outside this window the K<1 behaviour is recovered. The universal occurrence of a K>1 window in pairs of successive perceptions suggests that, at variance with single visual stimuli eliciting a suitable response, a pair of stimuli shortly separated in time displays mutual correlations.

An experimental study of non-destructive testing on glass fibre reinforced polymer composites after high velocity impact event

NASA Astrophysics Data System (ADS)

Razali, N.; Sultan, M. T. H.; Cardona, F.

2016-10-01

A non-destructive testing method on Glass Fibre Reinforced Polymer (GFRP) after high velocity impact event using single stage gas gun (SSGG) is presented. Specimens of C- type and E-type fibreglass reinforcement, which were fabricated with 6mm, 8mm, 10mm and 12mm thicknesses and size 100 mm x 100 mm, were subjected to a high velocity impact with three types of bullets: conical, hemispherical and blunt at various gas gun pressure levels from 6 bar to 60 bar. Visual observation techniques using a lab microscope were used to determine the infringed damage by looking at the crack zone. Dye penetrants were used to inspect the area of damage, and to evaluate internal and external damages on the specimens after impact. The results from visual analysis of the impacted test laminates were discussed and presented. It was found that the impact damage started with induced delamination, fibre cracking and then failure, simultaneously with matrix cracking and breakage, and finally followed by the fibres pulled out. C-type experienced more damaged areas compared to E-type of GFRP.

Development and Testing of Operational Dual-Polarimetric Radar Based Lightning Initiation Forecast Techniques

NASA Technical Reports Server (NTRS)

Woodard, Crystal; Carey, Lawrence D.; Petersen, Walter A.; Felix, Mariana; Roeder, William P.

2011-01-01

Lightning is one of Earth s natural dangers, destructive not only to life but also physical property. According to the National Weather Service, there are on average 58 lightning fatalities each year, with over 300 related injuries (NWS 2010). The ability to forecast lightning is critical to a host of activities ranging from space vehicle launch operations to recreational sporting events. For example a single lightning strike to a Space Shuttle could cause billions of dollars of damage and possible loss of life. While forecasting that provides longer lead times could provide sporting officials with more time to respond to possible threatening weather events, thus saving the lives of player and bystanders. Many researchers have developed and tested different methods and tools of first flash forecasting, however few have done so using dual-polarimetric radar variables and products on an operational basis. The purpose of this study is to improve algorithms for the short-term prediction of lightning initiation through development and testing of operational techniques that rely on parameters observed and diagnosed using C-band dual-polarimetric radar.

Simultaneous density-field visualization and PIV of the Richtmyer-Meshkov instability

NASA Astrophysics Data System (ADS)

Prestridge, Katherine; Rightley, Paul; Benjamin, Robert; Kurnit, Norman; Boxx, Isaac; Vorobieff, Peter

1999-11-01

We describe a highly-detailed experimental characterization of the Richtmyer-Meshkov instability. A vertical curtain of heavy gas (SF_6) flows into the test section of an air-filled, horizontal shock tube, and the instability evolves after the passage of a Mach 1.2 shock past the curtain. The evolution of the curtain is visualized by seeding the SF6 with small (d ≈ 0.5 μm) glycol/water droplets using a modified theatrical fog generator. Because the event lasts only 1 ms and the initial conditions vary from test to test, rapid and high-resolution (both spatial and temporal) data acquisition is required in order to characterize the initial and dynamic conditions for each experimental event. A customized, frequency-doubled, burst mode Nd:YAG laser and a commercial single-pulse laser are used for the implementation of simultaneous density-field imaging and PIV diagnostics. We have provided data about flow scaling and mixing through image analysis, and PIV data gives us further quantitative physical insight into the evolution of the Richtmyer-Meshkov instability.

Modeling of single event transients with dual double-exponential current sources: Implications for logic cell characterization

DOE PAGES

Black, Dolores Archuleta; Robinson, William H.; Wilcox, Ian Zachary; ...

2015-08-07

Single event effects (SEE) are a reliability concern for modern microelectronics. Bit corruptions can be caused by single event upsets (SEUs) in the storage cells or by sampling single event transients (SETs) from a logic path. Likewise, an accurate prediction of soft error susceptibility from SETs requires good models to convert collected charge into compact descriptions of the current injection process. This paper describes a simple, yet effective, method to model the current waveform resulting from a charge collection event for SET circuit simulations. The model uses two double-exponential current sources in parallel, and the results illustrate why a conventionalmore » model based on one double-exponential source can be incomplete. Furthermore, a small set of logic cells with varying input conditions, drive strength, and output loading are simulated to extract the parameters for the dual double-exponential current sources. As a result, the parameters are based upon both the node capacitance and the restoring current (i.e., drive strength) of the logic cell.« less

Single Low Dose Primaquine (0.25 mg/kg) Does Not Cause Clinically Significant Haemolysis in G6PD Deficient Subjects.

PubMed

Bancone, Germana; Chowwiwat, Nongnud; Somsakchaicharoen, Raweewan; Poodpanya, Lalita; Moo, Paw Khu; Gornsawun, Gornpan; Kajeechiwa, Ladda; Thwin, May Myo; Rakthinthong, Santisuk; Nosten, Suphak; Thinraow, Suradet; Nyo, Slight Naw; Ling, Clare L; Wiladphaingern, Jacher; Kiricharoen, Naw Lily; Moore, Kerryn A; White, Nicholas J; Nosten, Francois

2016-01-01

Primaquine is the only drug consistently effective against mature gametocytes of Plasmodium falciparum. The transmission blocking dose of primaquine previously recommended was 0.75 mg/kg (adult dose 45 mg) but its deployment was limited because of concerns over haemolytic effects in patients with glucose-6-phosphate dehydrogenase (G6PD) deficiency. G6PD deficiency is an inherited X-linked enzymatic defect that affects an estimated 400 million people around the world with high frequencies (15-20%) in populations living in malarious areas. To reduce transmission in low transmission settings and facilitate elimination of P. falciparum, the World Health Organization now recommends adding a single dose of 0.25 mg/kg (adult dose 15 mg) to Artemisinin-based Combination Therapies (ACTs) without G6PD testing. Direct evidence of the safety of this low dose is lacking. Adverse events and haemoglobin variations after this treatment were assessed in both G6PD normal and deficient subjects in the context of targeted malaria elimination in a malaria endemic area on the North-Western Myanmar-Thailand border where prevalence of G6PD deficiency (Mahidol variant) approximates 15%. The tolerability and safety of primaquine (single dose 0.25 mg base/kg) combined with dihydroartemisinin-piperaquine (DHA-PPQ) given three times at monthly intervals was assessed in 819 subjects. Haemoglobin concentrations were estimated over the six months preceding the ACT + primaquine rounds of mass drug administration. G6PD deficiency was assessed with a phenotypic test and genotyping was performed in male subjects with deficient phenotypes and in all females. Fractional haemoglobin changes in relation to G6PD phenotype and genotype and primaquine round were assessed using linear mixed-effects models. No adverse events related to primaquine were reported during the trial. Mean fractional haemoglobin changes after each primaquine treatment in G6PD deficient subjects (-5.0%, -4.2% and -4.7%) were greater than in G6PD normal subjects (0.3%, -0.8 and -1.7%) but were clinically insignificant. Fractional drops in haemoglobin concentration larger than 25% following single dose primaquine were observed in 1.8% of the population but were asymptomatic. The single low dose (0.25mg/kg) of primaquine is clinically well tolerated and can be used safely without prior G6PD testing in populations with high prevalence of G6PD deficiency. The present evidence supports a broader use of low dose primaquine without G6PD testing for the treatment and elimination of falciparum malaria. ClinicalTrials.gov NCT01872702.

Feasibility, safety and outcomes of playing Kinect Adventures!™ for people with Parkinson's disease: a pilot study.

PubMed

Pompeu, J E; Arduini, L A; Botelho, A R; Fonseca, M B F; Pompeu, S M A A; Torriani-Pasin, C; Deutsch, J E

2014-06-01

To assess the feasibility, safety and outcomes of playing Microsoft Kinect Adventures™ for people with Parkinson's disease in order to guide the design of a randomised clinical trial. Single-group, blinded trial. Rehabilitation Center of São Camilo University, Brazil. Seven patients (six males, one female) with Parkinson's disease (Hoehn and Yahr Stages 2 and 3). Fourteen 60-minute sessions, three times per week, playing four games of Kinect Adventures! The feasibility and safety outcomes were patients' game performance and adverse events, respectively. The clinical outcomes were the 6-minute walk test, Balance Evaluation System Test, Dynamic Gait Index and Parkinson's Disease Questionnaire (PDQ-39). Patients' scores for the four games showed improvement. The mean [standard deviation (SD)] scores in the first and last sessions of the Space Pop game were 151 (36) and 198 (29), respectively [mean (SD) difference 47 (7), 95% confidence interval 15 to 79]. There were no adverse events. Improvements were also seen in the 6-minute walk test, Balance Evaluation System Test, Dynamic Gait Index and PDQ-39 following training. Kinect-based training was safe and feasible for people with Parkinson's disease (Hoehn and Yahr Stages 2 and 3). Patients improved their scores for all four games. No serious adverse events occurred during training with Kinect Adventures!, which promoted improvement in activities (balance and gait), body functions (cardiopulmonary aptitude) and participation (quality of life). Copyright © 2013 Chartered Society of Physiotherapy. Published by Elsevier Ltd. All rights reserved.

The relative bioavailability and fasting pharmacokinetics of three formulations of olmesartan medoxomil 20-mg capsules and tablets in healthy Chinese male volunteers: An open-label, randomized-sequence, single-dose, three-way crossover study.

PubMed

Li, Kun-Yan; Liang, Jian-Ping; Hu, Bing-Qiang; Qiu, Yu; Luo, Chen-Hui; Jiang, Yun; Lin, Xiao-Ping; Yang, Nong

2010-08-01

Olmesartan medoxomil is an angiotensin II-receptor antagonist used in the treatment of hypertension. It is a prodrug and is converted to the pharmacologically active compound on de-esterification by arylesterase in the gastrointestinal tract. This study investigated the relative bioavailability and fasting pharmacokinetic properties of olmesartan after single doses of a 20-mg test tablet, a 20-mg test capsule, and a commercially available 20-mg reference tablet in healthy Chinese male volunteers. The study was conducted to satisfy Chinese State Food and Drug Administration regulatory requirements for approval of a generic formulation of olmesartan medoxomil. This study had an open-label, randomized-sequence, single-dose, 3-treatment, 3-period crossover design. Healthy volunteers were randomly assigned in a 1:1:1 ratio to receive a single 20-mg dose of the test tablet, test capsule, or reference tablet, each administered after a 12-hour overnight fast, followed by a 1-week washout period and administration of the alternate formulation. Blood samples were obtained at baseline and at 0.5, 1, 1.5,2,2.5,3,4,6,8,12,24,36, and 48 hours after dosing. Tolerability was assessed based on vital signs and laboratory values obtained before and after administration of study drug. The formulations were assumed to be bioequivalent if the 90% CIs for the log-transformed ratios of C(max), AUC(0-t), and AUC(0-∞) were within the predetermined equivalence range (70%-143% for C(max); 80%-125% for AUC(0-t) and AUC(0-∞)), as established by the Chinese State Food and Drug Administration. Twenty-one healthy male subjects (mean age, 21 years [range, 18-25 years]; weight, 62.1 kg [range, 54.0-80.0 kg]) were enrolled in and completed the study. No period or sequence effect was observed. The mean AUC(0-∞) values for the test tablet, test capsule, and reference tablet were 3993 (1070), 3567 (850), and 3849 (872) ng/mL/h, respectively. The 90% CIs for the log-transformed ratios of test tablet to reference tablet for C(max), AUC(0-48), and AUC(0-∞) were 103.9 to 124.9, 94.0 to 111.5, and 94.4 to 111.7, respectively (all, P = NS). The corresponding 90% CIs for the log-transformed ratios of test capsule to reference tablet were 90.8 to 109.2, 84.9 to 107.9, and 85.1 to 100.7 (all, P = NS). Ten adverse events were reported during the study; 7 subjects complained of pain during blood sampling, and 3 had a blocked venous catheter. No treatment-related adverse events were reported or observed. In this single-dose crossover study in healthy Chinese male volunteers, the test and reference formulations of olmesartan medoxomil 20-mg capsules and tablets met the regulatory criteria for assuming bioequivalence. The 3 formulations were well tolerated. Copyright © 2010 Excerpta Medica Inc. All rights reserved.

Comparison of total coliform, fecal coliform, and enterococcus bacterial indicator response for ocean recreational water quality testing.

PubMed

Noble, R T; Moore, D F; Leecaster, M K; McGee, C D; Weisberg, S B

2003-04-01

In July 1999, California's ocean recreational bacterial water quality standards were changed from a total coliform (TC) test to a standard requiring testing for all three bacterial indicators: TC, fecal coliforms (FC), and enterococci (EC). To compare the relationship between the bacterial indicators, and the effect that changing the standards would have on recreational water regulatory actions, three regional studies were conducted along the southern California shoreline from Santa Barbara to San Diego, California. Two studies were conducted during dry weather and one following a large storm event. In each study, samples were collected at over 200 sites which were selected using a stratified random design, with strata consisting of open beach areas and rocky shoreline, and areas near freshwater outlets that drain land-based runoff. During the dry weather studies, samples were collected once per week for 5 weeks. For the storm event study, sampling occurred on a single day about 24 h following the storm. The three indicator bacteria were measured at each site and the results were compared to the single sample standards (TC > 10,000; FC > 400 and EC > 104 MPN or cfu/100 ml). EC was the indicator that failed the single sample standards most often. During the wet weather study, 99% of all standard failures were detected using EC, compared with only 56% for FC, and 40% for TC. During the Summer Study, EC was again the indicator that failed the single sample standards most often, with 60% of the failures for EC alone. The increased failure of the EC standard occurred consistently regardless of whether the sample was collected at a beach or rocky shoreline site, or at a site near a freshwater outlet. Agreement among indicators was better during wet weather than during dry weather. During dry weather, agreement among indicators was better near freshwater outlets than along open shoreline. Cumulatively, our results suggest that replacement of a TC standard with an EC standard will lead to a five-fold increase in failures during dry weather and a doubling of failures during wet weather. Replacing a TC standard with one based on all three indicators will lead to an eight-fold increase in failures. Changes in the requirements for water quality testing have strong implications for increases in beach closures and restrictions. Copyright 2002 Elsevier Science Ltd.

Effects of Temperature and Supply Voltage on SEU- and SET-Induced Errors in Bulk 40-nm Sequential Circuits

NASA Astrophysics Data System (ADS)

Chen, R. M.; Diggins, Z. J.; Mahatme, N. N.; Wang, L.; Zhang, E. X.; Chen, Y. P.; Zhang, H.; Liu, Y. N.; Narasimham, B.; Witulski, A. F.; Bhuva, B. L.; Fleetwood, D. M.

2017-08-01

The single-event sensitivity of bulk 40-nm sequential circuits is investigated as a function of temperature and supply voltage. An overall increase in SEU cross section versus temperature is observed at relatively high supply voltages. However, at low supply voltages, there is a threshold temperature beyond which the SEU cross section decreases with further increases in temperature. Single-event transient induced errors in flip-flops also increase versus temperature at relatively high supply voltages and are more sensitive to temperature variation than those caused by single-event upsets.

Single Event Transient Analysis of an SOI Operational Amplifier for Use in Low-Temperature Martian Exploration

NASA Technical Reports Server (NTRS)

Laird, Jamie S.; Scheik, Leif; Vizkelethy, Gyorgy; Mojarradi, Mohammad M; Chen, Yuan; Miyahira, Tetsuo; Blalock, Benjamin; Greenwell, Robert; Doyle, Barney

2006-01-01

The next generation of Martian rover#s to be launched by JPL are to examine polar regions where temperatures are extremely low and the absence of an earth-like atmosphere results in high levels of cosmic radiation at ground level. Cosmic rays lead to a plethora of radiation effects including Single Event Transients (SET) which can severely degrade microelectronic functionality. As such, a radiation-hardened, temperature compensated CMOS Single-On-Insulator (SOI) Operational Amplifier has been designed for JPL by the University of Tennessee and fabricated by Honeywell using the SOI V process. SOI technology has been shownto be far less sensitive to transient effects than both bulk and epilayer Si. Broad beam heavy-ion tests at the University of Texas A&M using Kr and Xebeams of energy 25MeV/amu were performed to ascertain the duration and severity of the SET for the op-amp configured for a low and high gain application. However, some ambiguity regarding the location of transient formation required the use of a focused MeV ion microbeam. A 36MeV O6(+) microbeam. the Sandia National Laboratory (SNL) was used to image and verify regions of particular concern. This is a viewgraph presentation

Mechanical measurement of hydrogen bonded host-guest systems under non-equilibrium, near-physiological conditions.

PubMed

Naranjo, Teresa; Cerrón, Fernando; Nieto-Ortega, Belén; Latorre, Alfonso; Somoza, Álvaro; Ibarra, Borja; Pérez, Emilio M

2017-09-01

Decades after the birth of supramolecular chemistry, there are many techniques to measure noncovalent interactions, such as hydrogen bonding, under equilibrium conditions. As ensembles of molecules rapidly lose coherence, we cannot extrapolate bulk data to single-molecule events under non-equilibrium conditions, more relevant to the dynamics of biological systems. We present a new method that exploits the high force resolution of optical tweezers to measure at the single molecule level the mechanical strength of a hydrogen bonded host-guest pair out of equilibrium and under near-physiological conditions. We utilize a DNA reporter to unambiguously isolate single binding events. The Hamilton receptor-cyanuric acid host-guest system is used as a test bed. The force required to dissociate the host-guest system is ∼17 pN and increases with the pulling rate as expected for a system under non-equilibrium conditions. Blocking one of the hydrogen bonding sites results in a significant decrease of the force-to-break by 1-2 pN, pointing out the ability of the method to resolve subtle changes in the mechanical strength of the binding due to the individual H-bonding components. We believe the method will prove to be a versatile tool to address important questions in supramolecular chemistry.

A multicentre, randomised, controlled trial to assess the safety, ease of use, and reliability of hyaluronic acid/carboxymethylcellulose powder adhesion barrier versus no barrier in colorectal laparoscopic surgery.

PubMed

Berdah, Stéphane V; Mariette, Christophe; Denet, Christine; Panis, Yves; Laurent, Christophe; Cotte, Eddy; Huten, Nöel; Le Peillet Feuillet, Eliane; Duron, Jean-Jacques

2014-10-27

Intra-peritoneal adhesions are frequent following abdominal surgery and are the most common cause of small bowel obstructions. A hyaluronic acid/carboxymethylcellulose (HA/CMC) film adhesion barrier has been shown to reduce adhesion formation in abdominal surgery. An HA/CMC powder formulation was developed for application during laparoscopic procedures. This was an exploratory, prospective, randomised, single-blind, parallel-group, Phase IIIb, multicentre study conducted at 15 hospitals in France to assess the safety of HA/CMC powder versus no adhesion barrier following laparoscopic colorectal surgery. Subjects ≥18 years of age who were scheduled for colorectal laparoscopy (Mangram contamination class I‒III) within 8 weeks of selection were eligible, regardless of aetiology. Participants were randomised 1:1 to the HA/CMC powder or no adhesion barrier group using a centralised randomisation list. Patients assigned to HA/CMC powder received a single application of 1 to 10 g on adhesion-prone areas. In the no adhesion barrier group, no adhesion barrier or placebo was applied. The primary safety assessments were the incidence of adverse events, serious adverse events, and surgical site infections (SSIs) for 30 days following surgery. Between-group comparisons were made using Fisher's exact test. Of those randomised to the HA/CMC powder (n = 105) or no adhesion barrier (n = 104) groups, one patient in each group discontinued prior to the study end (one death in each group). Adverse events were more frequent in the HA/CMC powder group versus the no adhesion barrier group (63% vs. 39%; P <0.001), as were serious adverse events (28% vs. 11%; P <0.001). There were no statistically significant differences between the HA/CMC powder group and the no adhesion barrier group in SSIs (21% vs. 14%; P = 0.216) and serious SSIs (12% vs. 9%; P = 0.38), or in the most frequent serious SSIs of pelvic abscess (5% and 2%; significance not tested), anastomotic fistula (3% and 4%), and peritonitis (2% and 3%). This exploratory study found significantly higher rates of adverse events and serious adverse events in the HA/CMC powder group compared with the no adhesion barrier group in laparoscopic colorectal resection. ClinicalTrials.gov NCT00813397. Registered 19 December 2008.

A compact and modular x- and gamma-ray detector with a CsI scintillator and double-readout Silicon Drift Detectors

NASA Astrophysics Data System (ADS)

Campana, R.; Fuschino, F.; Labanti, C.; Marisaldi, M.; Amati, L.; Fiorini, M.; Uslenghi, M.; Baldazzi, G.; Bellutti, P.; Evangelista, Y.; Elmi, I.; Feroci, M.; Ficorella, F.; Frontera, F.; Picciotto, A.; Piemonte, C.; Rachevski, A.; Rashevskaya, I.; Rignanese, L. P.; Vacchi, A.; Zampa, G.; Zampa, N.; Zorzi, N.

2016-07-01

A future compact and modular X and gamma-ray spectrometer (XGS) has been designed and a series of proto- types have been developed and tested. The experiment envisages the use of CsI scintillator bars read out at both ends by single-cell 25 mm2 Silicon Drift Detectors. Digital algorithms are used to discriminate between events absorbed in the Silicon layer (lower energy X rays) and events absorbed in the scintillator crystal (higher energy X rays and -rays). The prototype characterization is shown and the modular design for future experiments with possible astrophysical applications (e.g. for the THESEUS mission proposed for the ESA M5 call) are discussed.

Operation of a LAr-TPC equipped with a multilayer LEM charge readout

DOE PAGES

Baibussinov, B.; Centro, S.; Farnese, C.; ...

2018-03-01

A novel detector for ionization signals in a single phase LAr-TPC has been experimented in the ICARINO test facility at the INFN Laboratories in Legnaro. It is based on the adoption of a multilayer Large Electron Multiplier (LEM) replacing the traditional anodic wire arrays. Cosmic muon tracks were detected allowing the measurement of energy deposition and a first determination of the signal to noise ratio. The analysis of the recorded events thus demonstrated the 3D reconstruction capability of this device for ionizing events in liquid Argon. The collected fraction of ionization charge is close to about 90%, with signal tomore » noise ratio similar to that measured with more traditional wire chambers.« less

Operation of a LAr-TPC equipped with a multilayer LEM charge readout

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

Baibussinov, B.; Centro, S.; Farnese, C.

A novel detector for ionization signals in a single phase LAr-TPC has been experimented in the ICARINO test facility at the INFN Laboratories in Legnaro. It is based on the adoption of a multilayer Large Electron Multiplier (LEM) replacing the traditional anodic wire arrays. Cosmic muon tracks were detected allowing the measurement of energy deposition and a first determination of the signal to noise ratio. The analysis of the recorded events thus demonstrated the 3D reconstruction capability of this device for ionizing events in liquid Argon. The collected fraction of ionization charge is close to about 90%, with signal tomore » noise ratio similar to that measured with more traditional wire chambers.« less

Field-aligned currents associated with multiple arc systems

NASA Astrophysics Data System (ADS)

Wu, J.; Knudsen, D. J.; Gillies, D. M.; Donovan, E.; Burchill, J. K.

2016-12-01

It is often thought that auroral arcs are a direct consequence of upward field-aligned currents. In fact, the relation between currents and brightness is more complicated. Multiple auroral arc systems provide and opportunity to study this relation in detail; this information can be used as a test of models for quasi-static arc formation. In this study, we have identified two types of FAC configurations in multiple parallel arc systems using ground-based optical data from the THEMIS all-sky imagers (ASIs), magnetometers and electric field instruments onboard the Swarm satellites during the period from December 2013 to March 2015. In type 1 events, each arc is an intensification within a broad, unipolar current sheet and downward currents only exist outside the upward current sheet. In type 2 events, multiple arc systems represent a collection of multiple up/down current pairs. By collecting 12 events for type 1 and 17 events for type 2, we find that (1) Type 1 events are mainly located between 22-23MLT. Type 2 events are mainly located around midnight. (2) The typical size of upward and downward FAC in type 2 events are comparable, while upward FAC in type 1 events are larger than downward FAC. (3) Upward currents with more arcs embedded have larger intensities and widths. (4) There is no significant difference between the characteristic widths of multiple arcs and single arcs.

Radiation Characteristics of a 0.11 Micrometer Modified Commercial CMOS Process

NASA Technical Reports Server (NTRS)

Poivey, Christian; Kim, Hak; Berg, Melanie D.; Forney, Jim; Seidleck, Christina; Vilchis, Miguel A.; Phan, Anthony; Irwin, Tim; LaBel, Kenneth A.; Saigusa, Rajan K.;

Physical and chemical analysis of lithium-ion battery cell-to-cell failure events inside custom fire chamber

NASA Astrophysics Data System (ADS)

Spinner, Neil S.; Field, Christopher R.; Hammond, Mark H.; Williams, Bradley A.; Myers, Kristina M.; Lubrano, Adam L.; Rose-Pehrsson, Susan L.; Tuttle, Steven G.

2015-04-01

A 5-cubic meter decompression chamber was re-purposed as a fire test chamber to conduct failure and abuse experiments on lithium-ion batteries. Various modifications were performed to enable remote control and monitoring of chamber functions, along with collection of data from instrumentation during tests including high speed and infrared cameras, a Fourier transform infrared spectrometer, real-time gas analyzers, and compact reconfigurable input and output devices. Single- and multi-cell packages of LiCoO2 chemistry 18650 lithium-ion batteries were constructed and data was obtained and analyzed for abuse and failure tests. Surrogate 18650 cells were designed and fabricated for multi-cell packages that mimicked the thermal behavior of real cells without using any active components, enabling internal temperature monitoring of cells adjacent to the active cell undergoing failure. Heat propagation and video recordings before, during, and after energetic failure events revealed a high degree of heterogeneity; some batteries exhibited short burst of sparks while others experienced a longer, sustained flame during failure. Carbon monoxide, carbon dioxide, methane, dimethyl carbonate, and ethylene carbonate were detected via gas analysis, and the presence of these species was consistent throughout all failure events. These results highlight the inherent danger in large format lithium-ion battery packs with regards to cell-to-cell failure, and illustrate the need for effective safety features.

Wave Pattern Peculiarities of Different Types of Explosions Conducted at Semipalatinsk Test Site

NASA Astrophysics Data System (ADS)

Sokolova, Inna

2014-05-01

The historical seismograms of the explosions conducted at the STS in 1949 - 1989 are of great interest for the researchers in the field of monitoring. Large number of air (86), surface (30) and underground nuclear explosions were conducted here in boreholes and tunnels (340). In addition to nuclear explosions, large chemical explosions were conducted at the Test Site. It is known that tectonic earthquakes occur on the Test Site territory and near it. Since 2005 the Institute of Geophysical Researches conducts works on digitizing the historical seismograms of nuclear explosions. Currently, the database contains more than 6000 digitized seismograms of nuclear explosions used for investigative monitoring tasks, major part of them (4000) are events from the STS region. Dynamic parameters of records of air, surface and underground nuclear explosions, as well as large chemical explosions with compact charge laying were investigated for seismic stations located on the territory of Kazakhstan using digitized records of the STS events. In addition, the comparison between salvo wave pattern and single explosions was conducted. The records of permanent and temporary seismic stations (epicentral distances range 100 - 800 km) were used for the investigations. Explosions spectra were analyzed, specific features of each class of events were found. The seismograms analysis shows that the wave pattern depends significantly on the explosion site and on the source type.

Impact of repeated single-metal and multi-metal pollution events on soil quality.

PubMed

Burges, Aritz; Epelde, Lur; Garbisu, Carlos

2015-02-01

Most frequently, soil metal pollution results from the occurrence of repeated single-metal and, above all, multi-metal pollution events, with concomitant adverse consequences for soil quality. Therefore, in this study, we evaluated the impact of repeated single-metal and multi-metal (Cd, Pb, Cu, Zn) pollution events on soil quality, as reflected by the values of a variety of soil microbial parameters with potential as bioindicators of soil functioning. Specifically, parameters of microbial activity (potentially mineralizable nitrogen, β-glucosidase and acid phosphatase activity) and biomass (fungal and bacterial gene abundance by RT-qPCR) were determined, in the artificially metal-polluted soil samples, at regular intervals over a period of 26 weeks. Similarly, we studied the evolution over time of CaCl2-extractable metal fractions, in order to estimate metal bioavailability in soil. Different metals showed different values of bioavailability and relative bioavailability ([metal]bio/[metal]tot) in soil throughout the experiment, under both repeated single-metal and multi-metal pollution events. Both repeated Zn-pollution and multi-metal pollution events led to a significant reduction in the values of acid phosphatase activity, and bacterial and fungal gene abundance, reflecting the negative impact of these repeated events on soil microbial activity and biomass, and, hence, soil quality. Copyright © 2014 Elsevier Ltd. All rights reserved.

Feasibility and potential effectiveness of a non-pharmacological multidisciplinary care programme for persons with generalised osteoarthritis: a randomised, multiple-baseline single-case study

PubMed Central

Kwakkenbos, Linda; Rietveld, Leonie; den Broeder, Alfons A; de Bie, Rob A; van den Ende, Cornelia H M

2012-01-01

Objectives To evaluate the feasibility and potential effectiveness of a 12-week, non-pharmacological multidisciplinary intervention in patients with generalised osteoarthritis (GOA). Design A randomised, concurrent, multiple-baseline single-case design. During the baseline period, the intervention period and the postintervention period, all participants completed several health outcomes twice a week on Visual Analogue Scales. Setting Rheumatology outpatient department of a specialised hospital in the Netherlands. Participants 1 man and four women (aged 51–76 years) diagnosed with GOA. Primary outcome measures To assess feasibility, the authors assessed the number of dropouts and adverse events, adherence rates and patients' satisfaction. Secondary outcome measures To assess the potential effectiveness, the authors assessed pain and self-efficacy using visual data inspection and randomisation tests. Results The intervention was feasible in terms of adverse events (none) and adherence rate but not in terms of participants' satisfaction with the intervention. Visual inspection of the data and randomisation testing demonstrated no effects on pain (p=0.93) or self-efficacy (p=0.85). Conclusions The results of the present study indicate that the proposed intervention for patients with GOA was insufficiently feasible and effective. The data obtained through this multiple-baseline study have highlighted several areas in which the therapy programme can be optimised. PMID:22815466

28 CFR 35.138 - Ticketing.

Code of Federal Regulations, 2013 CFR

2013-07-01

... for a single event or series of events shall modify its policies, practices, or procedures to ensure... the same terms and conditions as other tickets sold for the same event or series of events. (b... event or series of events shall, upon inquiry— (1) Inform individuals with disabilities, their...

A proton irradiation test facility for space research in Ankara, Turkey

NASA Astrophysics Data System (ADS)

Gencer, Ayşenur; Yiǧitoǧlu, Merve; Bilge Demirköz, Melahat; Efthymiopoulos, Ilias

2016-07-01

Space radiation often affects the electronic components' performance during the mission duration. In order to ensure reliable performance, the components must be tested to at least the expected dose that will be received in space, before the mission. Accelerator facilities are widely used for such irradiation tests around the world. Turkish Atomic Energy Authority (TAEA) has a 15MeV to 30MeV variable proton cyclotron in Ankara and the facility's main purpose is to produce radioisotopes in three different rooms for different target systems. There is also an R&D room which can be used for research purposes. This paper will detail the design and current state of the construction of a beamline to perform Single Event Effect (SEE) tests in Ankara for the first time. ESA ESCC No.25100 Standard Single Event Effect Test Method and Guidelines is being considered for these SEE tests. The proton beam kinetic energy must be between 20MeV and 200MeV according to the standard. While the proton energy is suitable for SEE tests, the beam size must be 15.40cm x 21.55cm and the flux must be between 10 ^{5} p/cm ^{2}/s to at least 10 ^{8} p/cm ^{2}/s according to the standard. The beam size at the entrance of the R&D room is mm-sized and the current is variable between 10μA and 1.2mA. Therefore, a defocusing beam line has been designed to enlarge the beam size and reduce the flux value. The beam line has quadrupole magnets to enlarge the beam size and the collimators and scattering foils are used for flux reduction. This facility will provide proton fluxes between 10 ^{7} p/cm ^{2}/s and 10 ^{10} p/cm ^{2}/s for the area defined in the standard when completed. Also for testing solar cells developed for space, the proton beam energy will be lowered below 10MeV. This project has been funded by Ministry of Development in Turkey and the beam line construction will finish in two years and SEE tests will be performed for the first time in Turkey.

Single event effects and laser simulation studies

NASA Technical Reports Server (NTRS)

Kim, Q.; Schwartz, H.; Mccarty, K.; Coss, J.; Barnes, C.

1993-01-01

The single event upset (SEU) linear energy transfer threshold (LETTH) of radiation hardened 64K Static Random Access Memories (SRAM's) was measured with a picosecond pulsed dye laser system. These results were compared with standard heavy ion accelerator (Brookhaven National Laboratory (BNL)) measurements of the same SRAM's. With heavy ions, the LETTH of the Honeywell HC6364 was 27 MeV-sq cm/mg at 125 C compared with a value of 24 MeV-sq cm/mg obtained with the laser. In the case of the second type of 64K SRAM, the IBM640lCRH no upsets were observed at 125 C with the highest LET ions used at BNL. In contrast, the pulsed dye laser tests indicated a value of 90 MeV-sq cm/mg at room temperature for the SEU-hardened IBM SRAM. No latchups or multiple SEU's were observed on any of the SRAM's even under worst case conditions. The results of this study suggest that the laser can be used as an inexpensive laboratory SEU prescreen tool in certain cases.

Multiple genetic origins of histidine-rich protein 2 gene deletion in Plasmodium falciparum parasites from Peru

PubMed Central

Akinyi, Sheila; Hayden, Tonya; Gamboa, Dionicia; Torres, Katherine; Bendezu, Jorge; Abdallah, Joseph F.; Griffing, Sean M.; Quezada, Wilmer Marquiño; Arrospide, Nancy; De Oliveira, Alexandre Macedo; Lucas, Carmen; Magill, Alan J.; Bacon, David J.; Barnwell, John W.; Udhayakumar, Venkatachalam

2013-01-01

The majority of malaria rapid diagnostic tests (RDTs) detect Plasmodium falciparum histidine-rich protein 2 (PfHRP2), encoded by the pfhrp2 gene. Recently, P. falciparum isolates from Peru were found to lack pfhrp2 leading to false-negative RDT results. We hypothesized that pfhrp2-deleted parasites in Peru derived from a single genetic event. We evaluated the parasite population structure and pfhrp2 haplotype of samples collected between 1998 and 2005 using seven neutral and seven chromosome 8 microsatellite markers, respectively. Five distinct pfhrp2 haplotypes, corresponding to five neutral microsatellite-based clonal lineages, were detected in 1998-2001; pfhrp2 deletions occurred within four haplotypes. In 2003-2005, outcrossing among the parasite lineages resulted in eight population clusters that inherited the five pfhrp2 haplotypes seen previously and a new haplotype; pfhrp2 deletions occurred within four of these haplotypes. These findings indicate that the genetic origin of pfhrp2 deletion in Peru was not a single event, but likely occurred multiple times. PMID:24077522

Galileo environmental test and analysis program summary

NASA Technical Reports Server (NTRS)

Hoffman, A. R.

1991-01-01

This paper presents an overview of the Galileo Project's environmental test and analysis program during the spacecraft development phase - October 1978 through launch in October 1989. After describing the top-level objectives of the program, summaries of-the approach, requirements, and margins are provided. Examples of assembly- and system-level test results are given for both the pre-1986 (direct mission) testing and the post-1986 (Venus-Earth-Earth gravity assist mission) testing, including dynamic, thermal, electromagnetic compatibility (EMC), and magnetic. The approaches and results for verifying by analysis that the requirements of certain environments (e.g., radiation, micrometeoroids, and single event upsets) are satisfied are presented. The environmental program implemented on Galileo satisfied the spirit and intent of the requirements imposed by the Project during the spacecraft's development. The lessons learned from the Galileo environmental program are discussed in this paper.

Large Area Flat Panel Imaging Detectors for Astronomy and Night Time Sensing

NASA Astrophysics Data System (ADS)

Siegmund, O.; McPhate, J.; Frisch, H.; Elam, J.; Mane, A.; Wagner, R.; Varner, G.

2013-09-01

Sealed tube photo-sensing detectors for optical/IR detection have applications in astronomy, nighttime remote reconnaissance, and airborne/space situational awareness. The potential development of large area photon counting, imaging, timing detectors has significance for these applications and a number of other areas (High energy particle detection (RICH), biological single-molecule fluorescence lifetime imaging microscopy, neutron imaging, time of flight mass spectroscopy, diffraction imaging). We will present details of progress towards the development of a 20 cm sealed tube optical detector with nanoengineered microchannel plates for photon counting, imaging and sub-ns event time stamping. In the operational scheme of the photodetector incoming light passes through an entrance window and interacts with a semitransparent photocathode on the inside of the window. The photoelectrons emitted are accelerated across a proximity gap and are detected by an MCP pair. The pair of novel borosilicate substrate MCPs are functionalized by atomic layer deposition (ALD), and amplify the signal and the resulting electron cloud is detected by a conductive strip line anode for determination of the event positions and the time of arrival. The physical package is ~ 25 x 25 cm but only 1.5 cm thick. Development of such a device in a square 20 cm format presents challenges: hermetic sealing to a large entrance window, a 20 cm semitransparent photocathode with good efficiency and uniformity, 20 cm MCPs with reasonable cost and performance, robust construction to preserve high vacuum and withstand an atmosphere pressure differential. We will discuss the schemes developed to address these issues and present the results for the first test devices. The novel microchannel plates employing borosilicate micro-capillary arrays provide many performance characteristics typical of conventional MCPs, but have been made in sizes up to 20 cm, have low intrinsic background (0.08 events cm2 s-1) and have very stable gain behavior over > 7 C cm2 of charge extracted. They are high temperature compatible and have minimal outgassing, which shortens and simplifies the sealed tube production process and should improve overall lifetimes. Bialkali (NaKSb) semitransparent photocathodes with > 20% quantum efficiency have also been made on 20 cm borosilicate windows compatible with the window seals for the large sealed tube device. The photocathodes have good response uniformity and have been stable for > 5 months in testing. Tests with a 20 cm detector with a cross delay line readout have achieved ~50µm FWHM imaging with single photon sub-ns timing and MHz event rates, and tests with a 10 x 10cm detector with cross strip readout has achieved ~20µm FWHM imaging with >4 MHz event rates with ~10% deadtime. We will discuss the details and implications of these novel detector implementations and their potential applications.

Empirical Modeling Of Single-Event Upset

NASA Technical Reports Server (NTRS)

Zoutendyk, John A.; Smith, Lawrence S.; Soli, George A.; Thieberger, Peter; Smith, Stephen L.; Atwood, Gregory E.

1988-01-01

Experimental study presents examples of empirical modeling of single-event upset in negatively-doped-source/drain metal-oxide-semiconductor static random-access memory cells. Data supports adoption of simplified worst-case model in which cross sectionof SEU by ion above threshold energy equals area of memory cell.

Potential impact of single-risk-factor versus total risk management for the prevention of cardiovascular events in Seychelles.

PubMed

Ndindjock, Roger; Gedeon, Jude; Mendis, Shanthi; Paccaud, Fred; Bovet, Pascal

2011-04-01

To assess the prevalence of cardiovascular (CV) risk factors in Seychelles, a middle-income African country, and compare the cost-effectiveness of single-risk-factor management (treating individuals with arterial blood pressure ≥ 140/90 mmHg and/or total serum cholesterol ≥ 6.2 mmol/l) with that of management based on total CV risk (treating individuals with a total CV risk ≥ 10% or ≥ 20%). CV risk factor prevalence and a CV risk prediction chart for Africa were used to estimate the 10-year risk of suffering a fatal or non-fatal CV event among individuals aged 40-64 years. These figures were used to compare single-risk-factor management with total risk management in terms of the number of people requiring treatment to avert one CV event and the number of events potentially averted over 10 years. Treatment for patients with high total CV risk (≥ 20%) was assumed to consist of a fixed-dose combination of several drugs (polypill). Cost analyses were limited to medication. A total CV risk of ≥ 10% and ≥ 20% was found among 10.8% and 5.1% of individuals, respectively. With single-risk-factor management, 60% of adults would need to be treated and 157 cardiovascular events per 100000 population would be averted per year, as opposed to 5% of adults and 92 events with total CV risk management. Management based on high total CV risk optimizes the balance between the number requiring treatment and the number of CV events averted. Total CV risk management is much more cost-effective than single-risk-factor management. These findings are relevant for all countries, but especially for those economically and demographically similar to Seychelles.

Aircraft Operations Classification System

NASA Technical Reports Server (NTRS)

Harlow, Charles; Zhu, Weihong

2001-01-01

Accurate data is important in the aviation planning process. In this project we consider systems for measuring aircraft activity at airports. This would include determining the type of aircraft such as jet, helicopter, single engine, and multiengine propeller. Some of the issues involved in deploying technologies for monitoring aircraft operations are cost, reliability, and accuracy. In addition, the system must be field portable and acceptable at airports. A comparison of technologies was conducted and it was decided that an aircraft monitoring system should be based upon acoustic technology. A multimedia relational database was established for the study. The information contained in the database consists of airport information, runway information, acoustic records, photographic records, a description of the event (takeoff, landing), aircraft type, and environmental information. We extracted features from the time signal and the frequency content of the signal. A multi-layer feed-forward neural network was chosen as the classifier. Training and testing results were obtained. We were able to obtain classification results of over 90 percent for training and testing for takeoff events.

Time-resolved single-shot terahertz time-domain spectroscopy for ultrafast irreversible processes

NASA Astrophysics Data System (ADS)

Zhai, Zhao-Hui; Zhong, Sen-Cheng; Li, Jun; Zhu, Li-Guo; Meng, Kun; Li, Jiang; Liu, Qiao; Peng, Qi-Xian; Li, Ze-Ren; Zhao, Jian-Heng

2016-09-01

Pulsed terahertz spectroscopy is suitable for spectroscopic diagnostics of ultrafast events. However, the study of irreversible or single shot ultrafast events requires ability to record transient properties at multiple time delays, i.e., time resolved at single shot level, which is not available currently. Here by angular multiplexing use of femtosecond laser pulses, we developed and demonstrated a time resolved, transient terahertz time domain spectroscopy technique, where burst mode THz pulses were generated and then detected in a single shot measurement manner. The burst mode THz pulses contain 2 sub-THz pulses, and the time gap between them is adjustable up to 1 ns with picosecond accuracy, thus it can be used to probe the single shot event at two different time delays. The system can detect the sub-THz pulses at 0.1 THz-2.5 THz range with signal to noise ratio (SNR) of ˜400 and spectrum resolution of 0.05 THz. System design was described here, and optimizations of single shot measurement of THz pulses were discussed in detail. Methods to improve SNR were also discussed in detail. A system application was demonstrated where pulsed THz signals at different time delays of the ultrafast process were successfully acquired within single shot measurement. This time resolved transient terahertz time domain spectroscopy technique provides a new diagnostic tool for irreversible or single shot ultrafast events where dynamic information can be extracted at terahertz range within one-shot experiment.

Time-resolved single-shot terahertz time-domain spectroscopy for ultrafast irreversible processes.

PubMed

Zhai, Zhao-Hui; Zhong, Sen-Cheng; Li, Jun; Zhu, Li-Guo; Meng, Kun; Li, Jiang; Liu, Qiao; Peng, Qi-Xian; Li, Ze-Ren; Zhao, Jian-Heng

2016-09-01

Pulsed terahertz spectroscopy is suitable for spectroscopic diagnostics of ultrafast events. However, the study of irreversible or single shot ultrafast events requires ability to record transient properties at multiple time delays, i.e., time resolved at single shot level, which is not available currently. Here by angular multiplexing use of femtosecond laser pulses, we developed and demonstrated a time resolved, transient terahertz time domain spectroscopy technique, where burst mode THz pulses were generated and then detected in a single shot measurement manner. The burst mode THz pulses contain 2 sub-THz pulses, and the time gap between them is adjustable up to 1 ns with picosecond accuracy, thus it can be used to probe the single shot event at two different time delays. The system can detect the sub-THz pulses at 0.1 THz-2.5 THz range with signal to noise ratio (SNR) of ∼400 and spectrum resolution of 0.05 THz. System design was described here, and optimizations of single shot measurement of THz pulses were discussed in detail. Methods to improve SNR were also discussed in detail. A system application was demonstrated where pulsed THz signals at different time delays of the ultrafast process were successfully acquired within single shot measurement. This time resolved transient terahertz time domain spectroscopy technique provides a new diagnostic tool for irreversible or single shot ultrafast events where dynamic information can be extracted at terahertz range within one-shot experiment.

Fault-Tolerant Sequencer Using FPGA-Based Logic Designs for Space Applications

DTIC Science & Technology

2013-12-01

Prototype Board SBU single bit upset SDK software development kit SDRAM synchronous dynamic random-access memory SEB single-event burnout ...current VHDL VHSIC hardware description language VHSIC very-high-speed integrated circuits VLSI very-large- scale integration VQFP very...transient pulse, called a single-event transient (SET), or even cause permanent damage to the device in the form of a burnout or gate rupture. The SEE

First observation of proton induced power MOSFET burnout in space: the CRUX experiment on APEX

NASA Astrophysics Data System (ADS)

Adolphsen, J. W.; Barth, J. L.; Gee, G. B.

1996-12-01

Ground testing has shown that power MOSFETs are susceptible to burnout when irradiated with heavy ions and protons. Satellite data from the Cosmic Ray Upset Experiment (CRUX) demonstrate that single event burnouts (SEBs) on 100-volt and 200-volt power MOSFETs can and do occur in space. Few SEBs occurred on the 100-volt devices, all at L/sup 1/>3. The 200-volt devices experienced many SEBs at L<3 when drain-to-source voltage (V/sub D-S/) was greater than 85% of maximum rated voltage. CRUX flight lot devices were ground tested with protons. The SEB rates calculated with the cross-sections from the ground tests show close agreement with the measured rates.

A NASA Perspective and Validation and Testing of Design Hardening for the Natural Space Radiation Environment (GOMAC Tech 03)

NASA Technical Reports Server (NTRS)

Day, John H. (Technical Monitor); LaBel, Kenneth A.; Howard, James W.; Carts, Martin A.; Seidleck, Christine

2003-01-01

With the dearth of dedicated radiation hardened foundries, new and novel techniques are being developed for hardening designs using non-dedicated foundry services. In this paper, we will discuss the implications of validating these methods for the natural space radiation environment issues: total ionizing dose (TID) and single event effects (SEE). Topics of discussion include: Types of tests that are required, Design coverage (i.e., design libraries: do they need validating for each application?) A new task within NASA to compare existing design. This latter task is a new effort in FY03 utilizing a 8051 microcontroller core from multiple design hardening developers as a test vehicle to evaluate each mitigative technique.

Prediction of Intensity Change Subsequent to Concentric Eyewall Events

NASA Astrophysics Data System (ADS)

Mauk, Rachel Grant

Concentric eyewall events have been documented numerous times in intense tropical cyclones over the last two decades. During a concentric eyewall event, an outer (secondary) eyewall forms around the inner (primary) eyewall. Improved instrumentation on aircraft and satellites greatly increases the likelihood of detecting an event. Despite the increased ability to detect such events, forecasts of intensity changes during and after these events remain poor. When concentric eyewall events occur near land, accurate intensity change predictions are especially critical to ensure proper emergency preparations and staging of recovery assets. A nineteen-year (1997-2015) database of concentric eyewall events is developed by analyzing microwave satellite imagery, aircraft- and land-based radar, and other published documents. Events are identified in both the North Atlantic and eastern North Pacific basins. TCs are categorized as single (1 event), serial (>= 2 events) and super-serial (>= 3 events). Key findings here include distinct spatial patterns for single and serial Atlantic TCs, a broad seasonal distribution for eastern North Pacific TCs, and apparent ENSO-related variability in both basins. The intensity change subsequent to the concentric eyewall event is calculated from the HURDAT2 database at time points relative to the start and to the end of the event. Intensity change is then categorized as Weaken (≤ -10 kt), Maintain (+/- 5 kt), and Strengthen (≥ 10 kt). Environmental conditions in which each event occurred are analyzed based on the SHIPS diagnostic files. Oceanic, dynamic, thermodynamic, and TC status predictors are selected for testing in a multiple discriminant analysis procedure to determine which variables successfully discriminate the intensity change category and the occurrence of additional concentric eyewall events. Intensity models are created for 12 h, 24 h, 36 h, and 48 h after the concentric eyewall events end. Leave-one-out cross validation is performed on each set of discriminators to generate classifications, which are then compared to observations. For each model, the top combinations achieve 80-95% overall accuracy in classifying TCs based on the environmental characteristics, although Maintain systems are frequently misclassified. The third part of this dissertation employs the Weather Research and Forecasting model to further investigate concentric eyewall events. Two serial Atlantic concentric eyewall cases (Katrina 2005 and Wilma 2005) are selected from the original study set, and WRF simulations performed using several model designs. Despite strong evidence from multiple sources that serial concentric eyewalls formed in both hurricanes, the WRF simulations did not produce identifiable concentric eyewall structures for Katrina, and only transient structures for Wilma. Possible reasons for the lack of concentric eyewall formation are discussed, including model resolution, microphysics, and data sources.

The origin of multiple clones in the parthenogenetic lizard species Darevskia rostombekowi.

PubMed

Ryskov, Alexey P; Osipov, Fedor A; Omelchenko, Andrey V; Semyenova, Seraphima K; Girnyk, Anastasiya E; Korchagin, Vitaly I; Vergun, Andrey A; Murphy, Robert W

2017-01-01

The all-female Caucasian rock lizard Darevskia rostombekowi and other unisexual species of this genus reproduce normally via true parthenogenesis. Typically, diploid parthenogenetic reptiles exhibit some amount of clonal diversity. However, allozyme data from D. rostombekowi have suggested that this species consists of a single clone. Herein, we test this hypothesis by evaluating variation at three variable microsatellite loci for 42 specimens of D. rostombekowi from four populations in Armenia. Analyses based on single nucleotide polymorphisms of each locus reveal five genotypes or presumptive clones in this species. All individuals are heterozygous at the loci. The major clone occurs in 24 individuals and involves three populations. Four rare clones involve one or several individuals from one or two populations. Most variation owes to parent-specific single nucleotide polymorphisms, which occur as heterozygotes. This result fails to reject the hypothesis of a single hybridization founder event that resulted in the initial formation of one major clone. The other clones appear to have originated via post-formation microsatellite mutations of the major clone.

Chemical Dosing and First-Order Kinetics

ERIC Educational Resources Information Center

Hladky, Paul W.

2011-01-01

College students encounter a variety of first-order phenomena in their mathematics and science courses. Introductory chemistry textbooks that discuss first-order processes, usually in conjunction with chemical kinetics or radioactive decay, stop at single, discrete dose events. Although single-dose situations are important, multiple-dose events,…

Characterization of System Level Single Event Upset (SEU) Responses using SEU Data, Classical Reliability Models, and Space Environment Data

NASA Technical Reports Server (NTRS)

Berg, Melanie; Label, Kenneth; Campola, Michael; Xapsos, Michael

2017-01-01

We propose a method for the application of single event upset (SEU) data towards the analysis of complex systems using transformed reliability models (from the time domain to the particle fluence domain) and space environment data.

Analyzing Single-Event Gate Ruptures In Power MOSFET's

NASA Technical Reports Server (NTRS)

Zoutendyk, John A.

1993-01-01

Susceptibilities of power metal-oxide/semiconductor field-effect transistors (MOSFET's) to single-event gate ruptures analyzed by exposing devices to beams of energetic bromine ions while applying appropriate bias voltages to source, gate, and drain terminals and measuring current flowing into or out of each terminal.

Cross-linguistic experiments in word-form recognition

NASA Astrophysics Data System (ADS)

Vihman, Marilyn

2004-05-01

When do children first represent word forms without experimental training or contextual support? Both English- and Welsh-learning children were tested, replicating Halle and Boysson-Bardies (1994: French, 11 months.). Twelve children acquiring English showed word-form recognition by 11 months (Vihman et al., in press); 12 Welsh children showed the effect at 12 months but a separate sample of 12 tested at 11 months did not (Vihman and DePaolis, 1999). A subsequent study of 16 children using event-related potentials (ERPs) showed word-form recognition within 250 ms for English at 11 months (Thierry et al., 2003). Attempts to locate the age of onset longitudinally proved problematic: Repeated tests of single samples of English and Welsh monolingual children (12 each) at 9, 10, 11, and 12 months showed that infant episodic memory interferes sufficiently with longitudinal observation based on a single set of stimuli to preclude drawing any conclusions. Cross-sectional samples of monolingual English and Welsh children (24 each) are currently being tested at 9 to12 months, using both head turn and ERPs, as are English/Welsh bilingual children at 11 months. These studies should yield solid information as to the age of onset of spontaneous word form representation. [ESRC support is gratefully acknowledged.

Uncertainties in radiation effect predictions for the natural radiation environments of space.

PubMed

McNulty, P J; Stassinopoulos, E G

1994-10-01

Future manned missions beyond low earth orbit require accurate predictions of the risk to astronauts and to critical systems from exposure to ionizing radiation. For low-level exposures, the hazards are dominated by rare single-event phenomena where individual cosmic-ray particles or spallation reactions result in potentially catastrophic changes in critical components. Examples might be a biological lesion leading to cancer in an astronaut or a memory upset leading to an undesired rocket firing. The risks of such events appears to depend on the amount of energy deposited within critical sensitive volumes of biological cells and microelectronic components. The critical environmental information needed to estimate the risks posed by the natural space environments, including solar flares, is the number of times more than a threshold amount of energy for an event will be deposited in the critical microvolumes. These predictions are complicated by uncertainties in the natural environments, particularly the composition of flares, and by the effects of shielding. Microdosimetric data for large numbers of orbits are needed to improve the environmental models and to test the transport codes used to predict event rates.

Uncertainties in radiation effect predictions for the natural radiation environments of space

NASA Technical Reports Server (NTRS)

Mcnulty, P. J.; Stassinopoulos, E. G.

1994-01-01

Future manned missions beyond low earth orbit require accurate predictions of the risk to astronauts and to critical systems from exposure to ionizing radiation. For low-level exposures, the hazards are dominated by rare single-event phenomena where individual cosmic-ray particles or spallation reactions result in potentially catastrophic changes in critical components. Examples might be a biological lesion leading to cancer in an astronaut or a memory upset leading to an undesired rocket firing. The risks of such events appears to depend on the amount of energy deposited within critical sensitive volumes of biological cells and microelectronic components. The critical environmental information needed to estimate the risks posed by the natural space environments, including solar flares, is the number of times more than a threshold amount of energy for an event will be deposited in the critical microvolumes. These predictions are complicated by uncertainties in the natural environments, particularly the composition of flares, and by the effects of shielding. Microdosimetric data for large numbers of orbits are needed to improve the environmental models and to test the transport codes used to predict event rates.

An iterative matching and locating technique for borehole microseismic monitoring

NASA Astrophysics Data System (ADS)

Chen, H.; Meng, X.; Niu, F.; Tang, Y.

2016-12-01

Microseismic monitoring has been proven to be an effective and valuable technology to image hydraulic fracture geometry. The success of hydraulic fracturing monitoring relies on the detection and characterization (i.e., location and focal mechanism estimation) of a maximum number of induced microseismic events. All the events are important to quantify the stimulated reservior volume (SRV) and characterize the newly created fracture network. Detecting and locating low magnitude events, however, are notoriously difficult, particularly at a high noisy production environment. Here we propose an iterative matching and locating technique (iMLT) to obtain a maximum detection of small events and the best determination of their locations from continuous data recorded by a single azimuth downhole geophone array. As the downhole array is located in one azimuth, the regular M&L using the P-wave cross-correlation only is not able to resolve the location of a matched event relative to the template event. We thus introduce the polarization direction in the matching, which significantly improve the lateral resolution of the M&L method based on numerical simulations with synthetic data. Our synthetic tests further indicate that the inclusion of S-wave cross-correlation data can help better constrain the focal depth of the matched events. We apply this method to a dataset recorded during hydraulic fracturing treatment of a pilot horizontal well within the shale play in southwest China. Our approach yields a more than fourfold increase in the number of located events, compared with the original event catalog from traditional downhole processing.

Incidence and risk factors of bleeding-related adverse events in patients with chronic lymphocytic leukemia treated with ibrutinib.

PubMed

Lipsky, Andrew H; Farooqui, Mohammed Z H; Tian, Xin; Martyr, Sabrina; Cullinane, Ann M; Nghiem, Khanh; Sun, Clare; Valdez, Janet; Niemann, Carsten U; Herman, Sarah E M; Saba, Nakhle; Soto, Susan; Marti, Gerald; Uzel, Gulbu; Holland, Steve M; Lozier, Jay N; Wiestner, Adrian

2015-12-01

Ibrutinib is associated with bleeding-related adverse events of grade ≤ 2 in severity, and infrequently with grade ≥ 3 events. To investigate the mechanisms of bleeding and identify patients at risk, we prospectively assessed platelet function and coagulation factors in our investigator-initiated trial of single-agent ibrutinib for chronic lymphocytic leukemia. At a median follow-up of 24 months we recorded grade ≤ 2 bleeding-related adverse events in 55% of 85 patients. No grade ≥ 3 events occurred. Median time to event was 49 days. The cumulative incidence of an event plateaued by 6 months, suggesting that the risk of bleeding decreases with continued therapy. At baseline, von Willebrand factor and factor VIII levels were often high and normalized on treatment. Platelet function measured via the platelet function analyzer (PFA-100™) was impaired in 22 patients at baseline and in an additional 19 patients on ibrutinib (often transiently). Collagen and adenosine diphosphate induced platelet aggregation was tested using whole blood aggregometry. Compared to normal controls, response to both agonists was decreased in all patients with chronic lymphocytic leukemia, whether on ibrutinib or not. Compared to untreated chronic lymphocytic leukemia patients, response to collagen showed a mild further decrement on ibrutinib, while response to adenosine diphosphate improved. All parameters associated with a significantly increased risk of bleeding-related events were present at baseline, including prolonged epinephrine closure time (HR 2.74, P=0.012), lower levels of von Willebrand factor activity (HR 2.73, P=0.009) and factor VIII (HR 3.73, P=0.0004). In conclusion, both disease and treatment-related factors influence the risk of bleeding. Patients at greater risk for bleeding of grade ≤ 2 can be identified by clinical laboratory tests and counseled to avoid aspirin, non-steroidal anti-inflammatory drugs and fish oils. ClinicalTrials.gov identifier NCT01500733. Copyright© Ferrata Storti Foundation.

Incidence and risk factors of bleeding-related adverse events in patients with chronic lymphocytic leukemia treated with ibrutinib

PubMed Central

Lipsky, Andrew H.; Farooqui, Mohammed Z.H.; Tian, Xin; Martyr, Sabrina; Cullinane, Ann M.; Nghiem, Khanh; Sun, Clare; Valdez, Janet; Niemann, Carsten U.; Herman, Sarah E. M.; Saba, Nakhle; Soto, Susan; Marti, Gerald; Uzel, Gulbu; Holland, Steve M.; Lozier, Jay N.; Wiestner, Adrian

2015-01-01

Ibrutinib is associated with bleeding-related adverse events of grade ≤2 in severity, and infrequently with grade ≥3 events. To investigate the mechanisms of bleeding and identify patients at risk, we prospectively assessed platelet function and coagulation factors in our investigator-initiated trial of single-agent ibrutinib for chronic lymphocytic leukemia. At a median follow-up of 24 months we recorded grade ≤2 bleeding-related adverse events in 55% of 85 patients. No grade ≥3 events occurred. Median time to event was 49 days. The cumulative incidence of an event plateaued by 6 months, suggesting that the risk of bleeding decreases with continued therapy. At baseline, von Willebrand factor and factor VIII levels were often high and normalized on treatment. Platelet function measured via the platelet function analyzer (PFA-100™) was impaired in 22 patients at baseline and in an additional 19 patients on ibrutinib (often transiently). Collagen and adenosine diphosphate induced platelet aggregation was tested using whole blood aggregometry. Compared to normal controls, response to both agonists was decreased in all patients with chronic lymphocytic leukemia, whether on ibrutinib or not. Compared to untreated chronic lymphocytic leukemia patients, response to collagen showed a mild further decrement on ibrutinib, while response to adenosine diphosphate improved. All parameters associated with a significantly increased risk of bleeding-related events were present at baseline, including prolonged epinephrine closure time (HR 2.74, P=0.012), lower levels of von Willebrand factor activity (HR 2.73, P=0.009) and factor VIII (HR 3.73, P=0.0004). In conclusion, both disease and treatment-related factors influence the risk of bleeding. Patients at greater risk for bleeding of grade ≤2 can be identified by clinical laboratory tests and counseled to avoid aspirin, non-steroidal anti-inflammatory drugs and fish oils. ClinicalTrials.gov identifier NCT01500733 PMID:26430171

Flat H Frangible Joint Evolution

NASA Technical Reports Server (NTRS)

Diegelman, Thomas E.; Hinkel, Todd J.; Benjamin, Andrew; Rochon, Brian V.; Brown, Christopher W.

2016-01-01

Space vehicle staging and separation events require pyrotechnic devices. They are single-use mechanisms that cannot be tested, nor can failure-tolerant performance be demonstrated in actual flight articles prior to flight use. This necessitates the implementation of a robust design and test approach coupled with a fully redundant, failure-tolerant explosive mechanism to ensure that the system functions even in the event of a single failure. Historically, NASA has followed the single failure-tolerant (SFT) design philosophy for all human-rated spacecraft, including the Space Shuttle Program. Following the end of this program, aerospace companies proposed building the next generation human-rated vehicles with off-the-shelf, non-redundant, zero-failure-tolerant (ZFT) separation systems. Currently, spacecraft and launch vehicle providers for both the Orion and Commercial Crew Programs (CCPs) plan to deviate from the heritage safety approach and NASA's SFT human rating requirements. Both programs' partners have base-lined ZFT frangible joints for vehicle staging and fairing separation. These joints are commercially available from pyrotechnic vendors. Non-human-rated missions have flown them numerous times. The joints are relatively easy to integrate structurally within the spacecraft. In addition, the separation event is debris free, and the resultant pyro shock is lower than that of other design solutions. It is, however, a serious deficiency to lack failure tolerance. When used for critical applications on human-rated vehicles, a single failure could potentially lead to loss of crew (LOC) or loss of mission (LOM)). The Engineering and Safety & Mission Assurance directorates within the NASA Johnson Space Center took action to address this safety issue by initiating a project to develop a fully redundant, SFT frangible joint design, known as the Flat H. Critical to the ability to retrofit on launch vehicles being developed, the SFT mechanisms must fit within the same three-dimensional envelope as current designs as well as meet structural loads requirements. There is increased mass associated with the redundant design, and the goal is to minimize the weight impact as much as possible. These requirements presented significant challenges, both technically and financially; these challenges will be explored in this paper. Perhaps greater than the technical issues confronted during this design process, were the financial considerations. These were a significant part of the story of this design and development plan. Insufficient financial and labor resources were formidable barriers to completing this project. Nevertheless, JSC personnel successfully conducted several test series at JSC with very useful results. The many lessons learned drove design improvements, performance efficiency, and increased functional reliability. This paper examines the significant technical and financial challenges that these requirements posed to the project team. It discusses the evolution of the SFT frangible joint design, including optimization, testing, and successful partnering of the Johnson Space Center (JSC) engineering and JSC safety organizations, to enhance the flight safety margin for America's next generation of human-rated space vehicles.

Single-Event Latchup Testing of the Micrel MIC4424 Dual Power MOSFET Driver

NASA Technical Reports Server (NTRS)

Pellish, J. A.; Boutte, A.; Kim, H.; Phan, A.; Topper, A.

2016-01-01

We conducted 47 exposures of four different MIC4424 devices and did not observe any SEL or high-current events. This included worst-case conditions with a LET of 81 MeV-sq cm/mg, applied voltage of 18.5 V, a case temperature greater than 120 C, and a final fluence of 1x10(exp 7)/sq cm. We also monitored both the outputs for the presence of SETs. While the period of the 1 MHz square wave was slightly altered in some cases, no pulses were added or deleted. 1. Purpose: The purpose of this testing is to characterize the BiCMOS/DMOS Micrel MIC4424 dual, non-inverting MOSFET driver for single-event latchup (SEL) susceptibility. These data will be used for flight lot evaluation purposes. 2. Devices Tested: The MIC4423/4424/4425 family are highly reliable BiCMOS/DMOS buffer/driver MOSFET drivers. They are higher output current versions of the MIC4426/4427/4428. They can survive up to 5V of noise spiking, of either polarity, on the ground pin. They can accept, without either damage or logic upset, up to half an amp of reverse current (either polarity) forced back into their outputs. Primarily intended for driving power MOSFETs, the MIC4423/4424/4425 drivers are suitable for driving other loads (capacitive, resistive, or inductive) which require low-impedance, high peak currents, and fast switching times. Heavily loaded clock lines, coaxial cables, or piezoelectric transducers are some examples. The only known limitation on loading is that total power dissipated in the driver must be kept within the maximum power dissipation limits of the package. Five (5) parts were provided for SEL testing. We prepared four parts for irradiation and reserved one piece as an un-irradiated control. More information about the devices can be found in Table 1. The parts were prepared for testing by removing the lid from the CDIP package to expose the target die. The parts were then soldered to small copper circuit adapter boards for easy handling. These parts are fabricated in a bulk BiCMOS/DMOS technology. Since we do not know the number of overlayers used in the fabrication processes, linear energy transfer calculations are determined based on the top-surface incident ion species and kinetic energy.

Assessment of the cardiac safety between cetuximab and panitumumab as single therapy in Chinese chemotherapy-refractory mCRC.

PubMed

Tang, Xue-Miao; Chen, Hao; Li, Qing; Song, Yiling; Zhang, Shuping; Xu, Xiao-Shuan; Xu, Yiwei; Chen, Shulin

2018-01-01

The cardiac safety of cetuximab and panitumumab, particularly as single agents, has not been investigated extensively. This trial was designed to specifically evaluate the cardiac safety of cetuximab and panitumumab as single therapy in Chinese chemotherapy-refractory metastatic colorectal cancer (mCRC) patients. Sixty-one patients received cetuximab at an initial dose of 400 mg/m 2 intravenously over 120 minutes on day 1 (week 1), followed by a maintenance dose of 250 mg/m 2 intravenously over 60 minutes on day 1 of each 7-day cycle. Forty-three patients received panitumumab at a dose of 6 mg/kg intravenously every 14 days. Routine laboratory tests and electrocardiogram (ECG) were performed at baseline, during therapy and after the treatment (4th and 10th months). The incidence of elevation of troponin I ultra (TNI Ultra), abnormal ECGs, cardiac events and noncardiac adverse events (AEs) were recorded and analyzed. The incidence of elevation of TNI Ultra between the two groups had no significance ( p =0.681), and TNI Ultra+ was observed more frequently in patients with metastases to more than three organs and they received fourth or above lines of chemotherapy. The most frequent abnormal ECG manifestations were nonspecific ST changes and QTc prolongation in the two groups. At 10 months after treatment, most of the abnormal ECG manifestations were reversed. The most common cardiac AEs of cetuximab and panitumumab included palpitations, dyspnea, chest pain and arrhythmias requiring treatment. Most of the events were mild and transient. The incidence of cardiac AEs had no significant difference between the two groups. Rash was still the most common noncardiac AE in both groups. Cetuximab and panitumumab showed favorable cardiac safety as single agents for Chinese chemotherapy-refractory mCRC patients. But monitoring for cardiac AEs is still necessary throughout the entire treatment process.

Mismatch repair factor MSH2-MSH3 binds and alters the conformation of branched DNA structures predicted to form during genetic recombination.

PubMed

Surtees, Jennifer A; Alani, Eric

2006-07-14

Genetic studies in Saccharomyces cerevisiae predict that the mismatch repair (MMR) factor MSH2-MSH3 binds and stabilizes branched recombination intermediates that form during single strand annealing and gene conversion. To test this model, we constructed a series of DNA substrates that are predicted to form during these recombination events. We show in an electrophoretic mobility shift assay that S. cerevisiae MSH2-MSH3 specifically binds branched DNA substrates containing 3' single-stranded DNA and that ATP stimulates its release from these substrates. Chemical footprinting analyses indicate that MSH2-MSH3 specifically binds at the double-strand/single-strand junction of branched substrates, alters its conformation and opens up the junction. Therefore, MSH2-MSH3 binding to its substrates creates a unique nucleoprotein structure that may signal downstream steps in repair that include interactions with MMR and nucleotide excision repair factors.

Probing microbubble targeting with atomic force microscopy.

PubMed

Sboros, V; Glynos, E; Ross, J A; Moran, C M; Pye, S D; Butler, M; McDicken, W N; Brown, S B; Koutsos, V

2010-10-01

Microbubble science is expanding beyond ultrasound imaging applications to biological targeting and drug/gene delivery. The characteristics of molecular targeting should be tested by a measurement system that can assess targeting efficacy and strength. Atomic force microscopy (AFM) is capable of piconewton force resolution, and is reported to measure the strength of single hydrogen bonds. An in-house targeted microbubble modified using the biotin-avidin chemistry and the CD31 antibody was used to probe cultures of Sk-Hep1 hepatic endothelial cells. We report that the targeted microbubbles provide a single distribution of adhesion forces with a median of 93pN. This interaction is assigned to the CD31 antibody-antigen unbinding event. Information on the distances between the interaction forces was obtained and could be important for future microbubble fabrication. In conclusion, the capability of single microbubbles to target cell lines was shown to be feasible with AFM.

Single nucleotide polymorphisms in long noncoding RNA, ANRIL, are not associated with severe periodontitis but with adverse cardiovascular events among patients with cardiovascular disease.

PubMed

Schulz, S; Seitter, L; Werdan, K; Hofmann, B; Schaller, H-G; Schlitt, A; Reichert, S

2018-05-06

Biological plausibility of an association between severe periodontitis and cardiovascular disease (CVD) has been proven. Genetic characteristics play an important role in both complex inflammatory diseases. Polymorphisms (single nucleotide polymorphisms [SNPs]) in the long noncoding RNA, antisense noncoding RNA in the INK4 locus (ANRIL), were shown to play a leading role in both diseases. The primary objectives of the study were to assess, among cardiovascular (CV angiographically proven ≥50% stenosis of a main coronary artery) patients, the impact of ANRIL SNPs rs133049 and rs3217992 on the severity of periodontitis and the previous history of coronary events, as well as on the occurrence of further adverse CV events. The prevalence of severe periodontitis was analyzed in 1002 CV patients. ANRIL SNPs rs133049 and rs3217992 were genotyped. The prognostic value of both ANRIL SNPs for combined CV endpoint (stroke/transient ischemic attack [TIA], myocardial infarction, death from a CV-related event, death from stroke) was evaluated after a 3-year follow-up period. Hazard ratios (HRs) were adjusted for established CV risk factors applying Cox regression. ANRIL SNPs rs133049 and rs3217992 were not associated with severe periodontitis or history of CVD in CV patients. In the Kaplan-Meier survival curve including the log rank-test (P = .036) and Cox regression (hazard ratio = 1.684, P = .009) the AA genotype of rs3217992 was shown to be an independent predictor for adverse CV events after 3 years of follow-up. SNPs in ANRIL are not risk modulators for severe periodontitis and history of CVD in CV patients. The AA genotype of ANRIL SNPs rs3217992 possesses prognostic power for further CV events within 3 years of follow-up. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

26 CFR 1.274-5A - Substantiation requirements.

Code of Federal Regulations, 2010 CFR

2010-04-01

... independent contractor to his client or customer in the regular course of good business practice. (b... nature occurring during the course of a single event shall be considered a single expenditure. To... the portion of such amount which is attributable to each person participating in the event giving rise...

Characterization of System on a Chip (SoC) Single Event Upset (SEU) Responses Using SEU Data, Classical Reliability Models, and Space Environment Data

NASA Technical Reports Server (NTRS)

Berg, Melanie; Label, Kenneth; Campola, Michael; Xapsos, Michael

2017-01-01

We propose a method for the application of single event upset (SEU) data towards the analysis of complex systems using transformed reliability models (from the time domain to the particle fluence domain) and space environment data.

New Mode For Single-Event Upsets

NASA Technical Reports Server (NTRS)

Zoutendyk, John A.; Smith, Lawrence S.; Soli, George A.; Lo, Roger Y.

1988-01-01

Report presents theory and experimental data regarding newly discovered mode for single-event upsets, (SEU's) in complementary metal-oxide/semiconductor, static random-access memories, CMOS SRAM's. SEU cross sections larger than those expected from previously known modes given rise to speculation regarding additional mode, and subsequent cross-section measurements appear to confirm speculation.

A bio-inspired system for spatio-temporal recognition in static and video imagery

NASA Astrophysics Data System (ADS)

Khosla, Deepak; Moore, Christopher K.; Chelian, Suhas

2007-04-01

This paper presents a bio-inspired method for spatio-temporal recognition in static and video imagery. It builds upon and extends our previous work on a bio-inspired Visual Attention and object Recognition System (VARS). The VARS approach locates and recognizes objects in a single frame. This work presents two extensions of VARS. The first extension is a Scene Recognition Engine (SCE) that learns to recognize spatial relationships between objects that compose a particular scene category in static imagery. This could be used for recognizing the category of a scene, e.g., office vs. kitchen scene. The second extension is the Event Recognition Engine (ERE) that recognizes spatio-temporal sequences or events in sequences. This extension uses a working memory model to recognize events and behaviors in video imagery by maintaining and recognizing ordered spatio-temporal sequences. The working memory model is based on an ARTSTORE1 neural network that combines an ART-based neural network with a cascade of sustained temporal order recurrent (STORE)1 neural networks. A series of Default ARTMAP classifiers ascribes event labels to these sequences. Our preliminary studies have shown that this extension is robust to variations in an object's motion profile. We evaluated the performance of the SCE and ERE on real datasets. The SCE module was tested on a visual scene classification task using the LabelMe2 dataset. The ERE was tested on real world video footage of vehicles and pedestrians in a street scene. Our system is able to recognize the events in this footage involving vehicles and pedestrians.

Usefulness of the novel risk estimation software, Heart Risk View, for the prediction of cardiac events in patients with normal myocardial perfusion SPECT.

PubMed

Sakatani, Tomohiko; Shimoo, Satoshi; Takamatsu, Kazuaki; Kyodo, Atsushi; Tsuji, Yumika; Mera, Kayoko; Koide, Masahiro; Isodono, Koji; Tsubakimoto, Yoshinori; Matsuo, Akiko; Inoue, Keiji; Fujita, Hiroshi

2016-12-01

Myocardial perfusion single-photon emission-computed tomography (SPECT) can predict cardiac events in patients with coronary artery disease with high accuracy; however, pseudo-negative cases sometimes occur. Heart Risk View, which is based on the prospective cohort study (J-ACCESS), is a software for evaluating cardiac event probability. We examined whether Heart Risk View was useful to evaluate the cardiac risk in patients with normal myocardial perfusion SPECT (MPS). We studied 3461 consecutive patients who underwent MPS to detect myocardial ischemia and those who had normal MPS were enrolled in this study (n = 698). We calculated cardiac event probability by Heart Risk View and followed-up for 3.8 ± 2.4 years. The cardiac events were defined as cardiac death, non-fatal myocardial infarction, and heart failure requiring hospitalization. During the follow-up period, 21 patients (3.0 %) had cardiac events. The event probability calculated by Heart Risk View was higher in the event group (5.5 ± 2.6 vs. 2.9 ± 2.6 %, p < 0.001). According to the receiver-operating characteristics curve, the cut-off point of the event probability for predicting cardiac events was 3.4 % (sensitivity 0.76, specificity 0.72, and AUC 0.85). Kaplan-Meier curves revealed that a higher event rate was observed in the high-event probability group by the log-rank test (p < 0.001). Although myocardial perfusion SPECT is useful for the prediction of cardiac events, risk estimation by Heart Risk View adds more prognostic information, especially in patients with normal MPS.

Radiation Requirements and Requirements Flowdown: Single Event Effects (SEEs) and Requirements

NASA Technical Reports Server (NTRS)

LaBel, Kenneth A.

2002-01-01

This short course session provides: (1) an overview of the single particle-induced hazard for space system as they apply in the natural space environment. This shall focus on the implementation of a single event effect hardness assurance (SEEHA) program for systems including system engineering approach and mitigation of effects. (2) The final portion of this session shell provide relevant real-life examples of in-flight performance of systems.

1987 Annual Conference on Nuclear and Space Radiation Effects, Snowmass Village, CO, July 28-31, 1987, Proceedings

NASA Technical Reports Server (NTRS)

1987-01-01

Various papers on nuclear and space radiation effects are presented. The general topics addressed include: basic mechanisms of radiation effects, single-event phenomena, temperature and field effects, modeling and characterization of radiation effects, IC radiation effects and hardening, and EMP/SGEMP/IEMP phenomena. Also considered are: dosimetry/energy-dependent effects, sensors in and for radiation environments, spacecraft charging and space radiation effects, radiation effects and devices, radiation effects on isolation technologies, and hardness assurance and testing techniques.

1992 IEEE Annual Conference on Nuclear and Space Radiation Effects, 29th, New Orleans, LA, July 13-17, 1992, Proceedings

NASA Technical Reports Server (NTRS)

Van Vonno, Nick W. (Editor)

1992-01-01

The papers presented in this volume provide an overview of recent theoretical and experimental research related to nuclear and space radiation effects. Topics dicussed include single event phenomena, radiation effects in particle detectors and associated electronics for accelerators, spacecraft charging, and space environments and effects. The discussion also covers hardness assurance and testing techniques, electromagnetic effects, radiation effects in devices and integrated circuits, dosimetry and radiation facilities, isolation techniques, and basic mechanisms.

Goal Structuring Notation in a Radiation Hardening Assurance Case for COTS-Based Spacecraft

NASA Technical Reports Server (NTRS)

Witulski, A.; Austin, R.; Evans, J.; Mahadevan, N.; Karsai, G.; Sierawski, B.; LaBel, K.; Reed, R.; Schrimpf, R.

2016-01-01

A systematic approach is presented to constructing a radiation assurance case using Goal Structuring Notation (GSN) for spacecraft containing COTS parts. The GSN paradigm is applied to an SRAM single-event upset experiment board designed to fly on a CubeSat in January 2017. A custom software language for development of a GSN assurance case is under development at Vanderbilt. Construction of a radiation assurance case without use of hardened parts or extensive radiation testing is discussed.

What Can We Learn From Proton Recoils about Heavy-Ion SEE Sensitivity?

NASA Technical Reports Server (NTRS)

Ladbury, Raymond L.

2016-01-01

The fact that protons cause single-event effects (SEE) in most devices through production of light-ion recoils has led to attempts to bound heavy-ion SEE susceptibility through use of proton data. Although this may be a viable strategy for some devices and technologies, the data must be analyzed carefully and conservatively to avoid over-optimistic estimates of SEE performance. We examine the constraints that proton test data can impose on heavy-ion SEE susceptibility.

Analysis of the Noise in Data from the Mt. Meron Array

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

Chambers, D. H.; Breitfeller, E.

2010-07-15

This memo describes an analysis of the noise in data obtained from the Mt. Meron seismic array in northern Israel. The overall objective is to development a method for removing noise from extraneous sources in the environment, increasing the sensitivity to seismic signals from far events. For this initial work, we concentrated on understanding the propagation characteristics of the noise in the frequency band from 0.1 – 8 Hz, and testing a model-based method for removing narrow band (single frequency) noise.

The value of time-averaged serum high-sensitivity C-reactive protein in prediction of mortality and dropout in peritoneal dialysis patients.

PubMed

Liu, Shou-Hsuan; Chen, Chao-Yu; Li, Yi-Jung; Wu, Hsin-Hsu; Lin, Chan-Yu; Chen, Yung-Chang; Chang, Ming-Yang; Hsu, Hsiang-Hao; Ku, Cheng-Lung; Tian, Ya-Chung

2017-01-01

C-reactive protein (CRP) is a useful biomarker for prediction of long-term outcomes in patients undergoing chronic dialysis. This observational cohort study evaluated whether the time-averaged serum high-sensitivity CRP (HS-CRP) level was a better predictor of clinical outcomes than a single HS-CRP level in patients undergoing peritoneal dialysis (PD). We classified 335 patients into three tertiles according to the time-averaged serum HS-CRP level and followed up regularly from January 2010 to December 2014. Clinical outcomes such as cardiovascular events, infection episodes, newly developed malignancy, encapsulating peritoneal sclerosis (EPS), dropout (death plus conversion to hemodialysis), and mortality were assessed. During a 5-year follow-up, 164 patients (49.0%) ceased PD; this included 52 patient deaths (15.5%), 100 patients (29.9%) who converted to hemodialysis, and 12 patients (3.6%) who received a kidney transplantation. The Kaplan-Meier survival analysis and log-rank test revealed a significantly worse survival accumulation in patients with high time-average HS-CRP levels. A multivariate Cox regression analysis revealed that a higher time-averaged serum HS-CRP level, older age, and the occurrence of cardiovascular events were independent mortality predictors. A higher time-averaged serum HS-CRP level, the occurrence of cardiovascular events, infection episodes, and EPS were important predictors of dropout. The receiver operating characteristic analysis verified that the value of the time-average HS-CRP level in predicting the 5-year mortality and dropout was superior to a single serum baseline HS-CRP level. This study shows that the time-averaged serum HS-CRP level is a better marker than a single baseline measurement in predicting the 5-year mortality and dropout in PD patients.

Choosing MUSE: Validation of a Low-Cost, Portable EEG System for ERP Research

PubMed Central

Krigolson, Olave E.; Williams, Chad C.; Norton, Angela; Hassall, Cameron D.; Colino, Francisco L.

2017-01-01

In recent years there has been an increase in the number of portable low-cost electroencephalographic (EEG) systems available to researchers. However, to date the validation of the use of low-cost EEG systems has focused on continuous recording of EEG data and/or the replication of large system EEG setups reliant on event-markers to afford examination of event-related brain potentials (ERP). Here, we demonstrate that it is possible to conduct ERP research without being reliant on event markers using a portable MUSE EEG system and a single computer. Specifically, we report the results of two experiments using data collected with the MUSE EEG system—one using the well-known visual oddball paradigm and the other using a standard reward-learning task. Our results demonstrate that we could observe and quantify the N200 and P300 ERP components in the visual oddball task and the reward positivity (the mirror opposite component to the feedback-related negativity) in the reward-learning task. Specifically, single sample t-tests of component existence (all p's < 0.05), computation of Bayesian credible intervals, and 95% confidence intervals all statistically verified the existence of the N200, P300, and reward positivity in all analyses. We provide with this research paper an open source website with all the instructions, methods, and software to replicate our findings and to provide researchers with an easy way to use the MUSE EEG system for ERP research. Importantly, our work highlights that with a single computer and a portable EEG system such as the MUSE one can conduct ERP research with ease thus greatly extending the possible use of the ERP methodology to a variety of novel contexts. PMID:28344546

Choosing MUSE: Validation of a Low-Cost, Portable EEG System for ERP Research.

PubMed

Krigolson, Olave E; Williams, Chad C; Norton, Angela; Hassall, Cameron D; Colino, Francisco L

2017-01-01

In recent years there has been an increase in the number of portable low-cost electroencephalographic (EEG) systems available to researchers. However, to date the validation of the use of low-cost EEG systems has focused on continuous recording of EEG data and/or the replication of large system EEG setups reliant on event-markers to afford examination of event-related brain potentials (ERP). Here, we demonstrate that it is possible to conduct ERP research without being reliant on event markers using a portable MUSE EEG system and a single computer. Specifically, we report the results of two experiments using data collected with the MUSE EEG system-one using the well-known visual oddball paradigm and the other using a standard reward-learning task. Our results demonstrate that we could observe and quantify the N200 and P300 ERP components in the visual oddball task and the reward positivity (the mirror opposite component to the feedback-related negativity) in the reward-learning task. Specifically, single sample t -tests of component existence (all p 's < 0.05), computation of Bayesian credible intervals, and 95% confidence intervals all statistically verified the existence of the N200, P300, and reward positivity in all analyses. We provide with this research paper an open source website with all the instructions, methods, and software to replicate our findings and to provide researchers with an easy way to use the MUSE EEG system for ERP research. Importantly, our work highlights that with a single computer and a portable EEG system such as the MUSE one can conduct ERP research with ease thus greatly extending the possible use of the ERP methodology to a variety of novel contexts.

Single Event Effects: Space and Atmospheric Environments

NASA Technical Reports Server (NTRS)

Barth, Janet L.

2003-01-01

The paper discusses the following: 1. Sun-Earth connections. 2. Heavy ions: galactic cosmic rays; solar particle events. 3. Protons: solar particle events; trapped. 4. Atmospheric neutrons. 5. Summary.

Near bed suspended sediment flux by single turbulent events

NASA Astrophysics Data System (ADS)

Amirshahi, Seyed Mohammad; Kwoll, Eva; Winter, Christian

2018-01-01

The role of small scale single turbulent events in the vertical mixing of near bed suspended sediments was explored in a shallow shelf sea environment. High frequency velocity and suspended sediment concentration (SSC; calibrated from the backscatter intensity) were collected using an Acoustic Doppler Velocimeter (ADV). Using quadrant analysis, the despiked velocity time series was divided into turbulent events and small background fluctuations. Reynolds stress and Turbulent Kinetic Energy (TKE) calculated from all velocity samples, were compared to the same turbulent statistics calculated only from velocity samples classified as turbulent events (Reevents and TKEevents). The comparison showed that Reevents and TKEevents was increased 3 and 1.6 times, respectively, when small background fluctuations were removed and that the correlation with SSC for TKE could be improved through removal of the latter. The correlation between instantaneous vertical turbulent flux (w ‧) and SSC fluctuations (SSC ‧) exhibits a tidal pattern with the maximum correlation at peak ebb and flood currents, when strong turbulent events appear. Individual turbulent events were characterized by type, strength, duration and length. Cumulative vertical turbulent sediment fluxes and average SSC associated with individual turbulent events were calculated. Over the tidal cycle, ejections and sweeps were the most dominant events, transporting 50% and 36% of the cumulative vertical turbulent event sediment flux, respectively. Although the contribution of outward interactions to the vertical turbulent event sediment flux was low (11%), single outward interaction events were capable of inducing similar SSC ‧ as sweep events. The results suggest that on time scales of tens of minutes to hours, TKE may be appropriate to quantify turbulence in sediment transport studies, but that event characteristics, particular the upward turbulent flux need to be accounted for when considering sediment transport on process time scales.

Nitrous oxide emission from wetland soil following single and seasonal split application of cattle manure to field tomato (Lycopersicon esculentum, Mill var. Heinz) and rape (Brassica napus, L. var. Giant) crops.

PubMed

Masaka, Johnson; Nyamangara, Justice; Wuta, Menas

2016-01-01

An understanding of the contribution of manure applications to global atmospheric N2O loading is needed to evaluate agriculture's contribution to the global warming process. Two field experiments were carried out at Dufuya wetland (19°17'S; 29°21'E, 1260 m above sea level) to determine the effects of single and split manure applications on emissions of N2O from soil during the growing seasons of two rape and two tomato crops. Two field experiments were established. In the first experiment the manure was applied in three levels of 0, 15, and 30 Mg ha(-1) as a single application just before planting of the first tomato crop. In the second experiment the 15 and 30 Mg ha(-1) manure application rates were divided into four split applications of 3.75 and 7.5 Mg ha(-1) respectively, for each of the four cropping events. Single applications of 15 and 30 Mg ha(-1) manure once in four cropping events had higher emissions of N2O than those recorded on plots that received split applications of 3.75 and 7.5 Mg ha(-1) manure at least up to the second test crop. Thereafter N2O emissions on plots subjected to split applications of manure were higher or equal to those recorded in plots that received single basal applications of 30 Mg ha(-1) applied a week before planting the first crop. Seasonal split applications of manure to wetland vegetable crops can reduce emissions of N2O at least up to the second seasonal split application.

Noninvasive studies of human visual cortex using neuromagnetic techniques

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

Aine, C.J.; George, J.S.; Supek, S.

1990-01-01

The major goals of noninvasive studies of the human visual cortex are: to increase knowledge of the functional organization of cortical visual pathways; and to develop noninvasive clinical tests for the assessment of cortical function. Noninvasive techniques suitable for studies of the structure and function of human visual cortex include magnetic resonance imaging (MRI), positron emission tomography (PET), single photon emission tomography (SPECT), scalp recorded event-related potentials (ERPs), and event-related magnetic fields (ERFs). The primary challenge faced by noninvasive functional measures is to optimize the spatial and temporal resolution of the measurement and analytic techniques in order to effectively characterizemore » the spatial and temporal variations in patterns of neuronal activity. In this paper we review the use of neuromagnetic techniques for this purpose. 8 refs., 3 figs.« less

Gravitational microlensing of gamma-ray bursts

NASA Technical Reports Server (NTRS)

Mao, Shude

1993-01-01

A Monte Carlo code is developed to calculate gravitational microlensing in three dimensions when the lensing optical depth is low or moderate (not greater than 0.25). The code calculates positions of microimages and time delays between the microimages. The majority of lensed gamma-ray bursts should show a simple double-burst structure, as predicted by a single point mass lens model. A small fraction should show complicated multiple events due to the collective effects of several point masses (black holes). Cosmological models with a significant fraction of mass density in massive compact objects can be tested by searching for microlensing events in the current BATSE data. Our catalog generated by 10,000 Monte Carlo models is accessible through the computer network. The catalog can be used to take realistic selection effects into account.

LLNL Location and Detection Research

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

Myers, S C; Harris, D B; Anderson, M L

2003-07-16

We present two LLNL research projects in the topical areas of location and detection. The first project assesses epicenter accuracy using a multiple-event location algorithm, and the second project employs waveform subspace Correlation to detect and identify events at Fennoscandian mines. Accurately located seismic events are the bases of location calibration. A well-characterized set of calibration events enables new Earth model development, empirical calibration, and validation of models. In a recent study, Bondar et al. (2003) develop network coverage criteria for assessing the accuracy of event locations that are determined using single-event, linearized inversion methods. These criteria are conservative andmore » are meant for application to large bulletins where emphasis is on catalog completeness and any given event location may be improved through detailed analysis or application of advanced algorithms. Relative event location techniques are touted as advancements that may improve absolute location accuracy by (1) ensuring an internally consistent dataset, (2) constraining a subset of events to known locations, and (3) taking advantage of station and event correlation structure. Here we present the preliminary phase of this work in which we use Nevada Test Site (NTS) nuclear explosions, with known locations, to test the effect of travel-time model accuracy on relative location accuracy. Like previous studies, we find that the reference velocity-model and relative-location accuracy are highly correlated. We also find that metrics based on travel-time residual of relocated events are not a reliable for assessing either velocity-model or relative-location accuracy. In the topical area of detection, we develop specialized correlation (subspace) detectors for the principal mines surrounding the ARCES station located in the European Arctic. Our objective is to provide efficient screens for explosions occurring in the mines of the Kola Peninsula (Kovdor, Zapolyarny, Olenogorsk, Khibiny) and the major iron mines of northern Sweden (Malmberget, Kiruna). In excess of 90% of the events detected by the ARCES station are mining explosions, and a significant fraction are from these northern mining groups. The primary challenge in developing waveform correlation detectors is the degree of variation in the source time histories of the shots, which can result in poor correlation among events even in close proximity. Our approach to solving this problem is to use lagged subspace correlation detectors, which offer some prospect of compensating for variation and uncertainty in source time functions.« less

Radiation Testing and Evaluation Issues for Modern Integrated Circuits

NASA Technical Reports Server (NTRS)

LaBel, Kenneth A.; Cohn, Lew M.

2005-01-01

Abstract. Changes in modern integrated circuit (IC) technologies have modified the way we approach and conduct radiation tolerance and testing of electronics. These changes include scaling of geometries, new materials, new packaging technologies, and overall speed and device complexity challenges. In this short course section, we will identify and discuss these issues as they impact radiation testing, modeling, and effects mitigation of modern integrated circuits. The focus will be on CMOS-based technologies, however, other high performance technologies will be discussed where appropriate. The effects of concern will be: Single-Event Effects (SEE) and steady state total ionizing dose (TID) IC response. However, due to the growing use of opto-electronics in space systems issues concerning displacement damage testing will also be considered. This short course section is not intended to provide detailed "how-to-test" information, but simply provide a snapshot of current challenges and some of the approaches being considered.

Can tokamaks PFC survive a single event of any plasma instabilities?

NASA Astrophysics Data System (ADS)

Hassanein, A.; Sizyuk, V.; Miloshevsky, G.; Sizyuk, T.

2013-07-01

Plasma instability events such as disruptions, edge-localized modes (ELMs), runaway electrons (REs), and vertical displacement events (VDEs) are continued to be serious events and most limiting factors for successful tokamak reactor concept. The plasma-facing components (PFCs), e.g., wall, divertor, and limited surfaces of a tokamak as well as coolant structure materials are subjected to intense particle and heat loads and must maintain a clean and stable surface environment among them and the core/edge plasma. Typical ITER transient events parameters are used for assessing the damage from these four different instability events. HEIGHTS simulation showed that a single event of a disruption, giant ELM, VDE, or RE can cause significant surface erosion (melting and vaporization) damage to PFC, nearby components, and/or structural materials (VDE, RE) melting and possible burnout of coolant tubes that could result in shut down of reactor for extended repair time.

Arden Syntax Clinical Foundation Framework for Event Monitoring in Intensive Care Units: Report on a Pilot Study.

PubMed

de Bruin, Jeroen S; Zeckl, Julia; Adlassnig, Katharina; Blacky, Alexander; Koller, Walter; Rappelsberger, Andrea; Adlassnig, Klaus-Peter

2017-01-01

The creation of clinical decision support systems has received a strong impulse over the last years, but their integration into a clinical routine has lagged behind, partly due to a lack of interoperability and trust by physicians. We report on the implementation of a clinical foundation framework in Arden Syntax, comprising knowledge units for (a) preprocessing raw clinical data, (b) the determination of single clinical concepts, and (c) more complex medical knowledge, which can be modeled through the composition and configuration of knowledge units in this framework. Thus, it can be tailored to clinical institutions or patients' caregivers. In the present version, we integrated knowledge units for several infection-related clinical concepts into the framework and developed a clinical event monitoring system over the framework that employs three different scenarios for monitoring clinical signs of bloodstream infection. The clinical event monitoring system was tested using data from intensive care units at Vienna General Hospital, Austria.

Simulations of cloud-radiation interaction using large-scale forcing derived from the CINDY/DYNAMO northern sounding array

DOE PAGES

Wang, Shuguang; Sobel, Adam H.; Fridlind, Ann; ...

2015-09-25

The recently completed CINDY/DYNAMO field campaign observed two Madden-Julian oscillation (MJO) events in the equatorial Indian Ocean from October to December 2011. Prior work has indicated that the moist static energy anomalies in these events grew and were sustained to a significant extent by radiative feedbacks. We present here a study of radiative fluxes and clouds in a set of cloud-resolving simulations of these MJO events. The simulations are driven by the large scale forcing dataset derived from the DYNAMO northern sounding array observations, and carried out in a doubly-periodic domain using the Weather Research and Forecasting (WRF) model. simulatedmore » cloud properties and radiative fluxes are compared to those derived from the S-Polka radar and satellite observations. Furthermore, to accommodate the uncertainty in simulated cloud microphysics, a number of single moment (1M) and double moment (2M) microphysical schemes in the WRF model are tested.« less

Development and validation of a 48-target analytical method for high-throughput monitoring of genetically modified organisms.

PubMed

Li, Xiaofei; Wu, Yuhua; Li, Jun; Li, Yunjing; Long, Likun; Li, Feiwu; Wu, Gang

2015-01-05

The rapid increase in the number of genetically modified (GM) varieties has led to a demand for high-throughput methods to detect genetically modified organisms (GMOs). We describe a new dynamic array-based high throughput method to simultaneously detect 48 targets in 48 samples on a Fludigm system. The test targets included species-specific genes, common screening elements, most of the Chinese-approved GM events, and several unapproved events. The 48 TaqMan assays successfully amplified products from both single-event samples and complex samples with a GMO DNA amount of 0.05 ng, and displayed high specificity. To improve the sensitivity of detection, a preamplification step for 48 pooled targets was added to enrich the amount of template before performing dynamic chip assays. This dynamic chip-based method allowed the synchronous high-throughput detection of multiple targets in multiple samples. Thus, it represents an efficient, qualitative method for GMO multi-detection.

Development and Validation of A 48-Target Analytical Method for High-throughput Monitoring of Genetically Modified Organisms

PubMed Central

Li, Xiaofei; Wu, Yuhua; Li, Jun; Li, Yunjing; Long, Likun; Li, Feiwu; Wu, Gang

2015-01-01

The rapid increase in the number of genetically modified (GM) varieties has led to a demand for high-throughput methods to detect genetically modified organisms (GMOs). We describe a new dynamic array-based high throughput method to simultaneously detect 48 targets in 48 samples on a Fludigm system. The test targets included species-specific genes, common screening elements, most of the Chinese-approved GM events, and several unapproved events. The 48 TaqMan assays successfully amplified products from both single-event samples and complex samples with a GMO DNA amount of 0.05 ng, and displayed high specificity. To improve the sensitivity of detection, a preamplification step for 48 pooled targets was added to enrich the amount of template before performing dynamic chip assays. This dynamic chip-based method allowed the synchronous high-throughput detection of multiple targets in multiple samples. Thus, it represents an efficient, qualitative method for GMO multi-detection. PMID:25556930

Effects of multiple scattering on time- and depth-resolved signals in airborne lidar systems

NASA Technical Reports Server (NTRS)

Punjabi, A.; Venable, D. D.

1986-01-01

A semianalytic Monte Carlo radiative transfer model (SALMON) is employed to probe the effects of multiple-scattering events on the time- and depth-resolved lidar signals from homogeneous aqueous media. The effective total attenuation coefficients in the single-scattering approximation are determined as functions of dimensionless parameters characterizing the lidar system and the medium. Results show that single-scattering events dominate when these parameters are close to their lower bounds and that when their values exceed unity multiple-scattering events dominate.

Destructive Single-Event Effects in Diodes

NASA Technical Reports Server (NTRS)

Casey, Megan C.; Lauenstein, Jean-Marie; Campola, Michael J.; Wilcox, Edward P.; Phan, Anthony M.; Label, Kenneth A.

2017-01-01

In this work, we discuss the observed single-event effects in a variety of types of diodes. In addition, we conduct failure analysis on several Schottky diodes that were heavy-ion irradiated. High- and low-magnitude optical microscope images, infrared camera images, and scanning electron microscope images are used to identify and describe the failure locations.

Planning Single-Event Nutrition Education: A New Model

ERIC Educational Resources Information Center

Brown, Lora Beth

2011-01-01

A theoretical model for planning single-event nutrition education contrasts a Practical, Foods, and Positive (PFP) emphasis to an Abstract, Nutrient, and Negative (ANN) focus on nutrition topics. Use of this model makes messages more appealing to consumers and may increase the likelihood that people will apply the nutrition information in their…

Effects of cosmic rays on single event upsets

NASA Technical Reports Server (NTRS)

Lowe, Calvin W.; Oladipupo, Adebisi O.; Venable, Demetrius D.

1988-01-01

The efforts at establishing a research program in space radiation effects are discussed. The research program has served as the basis for training several graduate students in an area of research that is of importance to NASA. In addition, technical support was provided for the Single Event Facility Group at Brookhaven National Laboratory.

Single-Event Rapid Word Collection Workshops: Efficient, Effective, Empowering

ERIC Educational Resources Information Center

Boerger, Brenda H.; Stutzman, Verna

2018-01-01

In this paper we describe single-event Rapid Word Collection (RWC) workshop results in 12 languages, and compare these results to fieldwork lexicons collected by other means. We show that this methodology of collecting words by semantic domain by community engagement leads to obtaining more words in less time than conventional collection methods.…

Single Event Effects (SEE) for Power Metal-Oxide-Semiconductor Field-Effect Transistors (MOSFETs)

NASA Technical Reports Server (NTRS)

Lauenstein, Jean-Marie

2011-01-01

Single-event gate rupture (SEGR) continues to be a key failure mode in power MOSFETs. (1) SEGR is complex, making rate prediction difficult SEGR mechanism has two main components: (1) Oxide damage-- Reduces field required for rupture (2) Epilayer response -- Creates transient high field across the oxide.

Using single-case experimental design methodology to evaluate the effects of the ABC method for nursing staff on verbal aggressive behaviour after acquired brain injury.

PubMed

Winkens, Ieke; Ponds, Rudolf; Pouwels, Climmy; Eilander, Henk; van Heugten, Caroline

2014-01-01

The ABC method is a basic and simplified form of behavioural modification therapy for use by nurses. ABC refers to the identification of Antecedent events, target Behaviours, and Consequent events. A single-case experimental AB design was used to evaluate the effects of the ABC method on a woman diagnosed with olivo-ponto-cerebellar ataxia. Target behaviour was verbal aggressive behaviour during ADL care, assessed at 9 time points immediately before implementation of the ABC method and at 36 time points after implementation. A randomisation test showed a significant treatment effect between the baseline and intervention phases (t = .58, p = .03; ES [Nonoverlap All Pairs] = .62). Visual analysis, however, showed that the target behaviour was still present after implementation of the method and that on some days the nurses even judged the behaviour to be more severe than at baseline. Although the target behaviour was still present after treatment, the ABC method seems to be a promising tool for decreasing problem behaviour in patients with acquired brain injury. It is worth investigating the effects of this method in future studies. When interpreting single-subject data, both visual inspection and statistical analysis are needed to determine whether treatment is effective and whether the effects lead to clinically desirable results.

The maximum single dose of resistant maltodextrin that does not cause diarrhea in humans.

PubMed

Kishimoto, Yuka; Kanahori, Sumiko; Sakano, Katsuhisa; Ebihara, Shukuko

2013-01-01

The objective of the present study was to determine the maximum dose of resistant maltodextrin (Fibersol)-2, a non-viscous water-soluble dietary fiber), that does not induce transitory diarrhea. Ten healthy adult subjects (5 men and 5 women) ingested Fibersol-2 at increasing dose levels of 0.7, 0.8, 0.9, 1.0, and 1.1 g/kg body weight (bw). Each administration was separated from the previous dose by an interval of 1 wk. The highest dose level that did not cause diarrhea in any subject was regarded as the maximum non-effective level for a single dose. The results showed that no subject of either sex experienced diarrhea at dose levels of 0.7, 0.8, 0.9, or 1.0 g/kg bw. At the highest dose level of 1.1 g/kg bw, no female subject experienced diarrhea, whereas 1 male subject developed diarrhea with muddy stools 2 h after ingestion of the test substance. Consequently, the maximum non-effective level for a single dose of the resistant maltodextrin Fibersol-2 is 1.0 g/kg bw for men and >1.1 g/kg bw for women. Gastrointestinal symptoms were gurgling sounds in 4 subjects (7 events) and flatus in 5 subjects (9 events), although no association with dose level was observed. These symptoms were mild and transient and resolved without treatment.

Photon Counting Imaging with an Electron-Bombarded Pixel Image Sensor

PubMed Central

Hirvonen, Liisa M.; Suhling, Klaus

2016-01-01

Electron-bombarded pixel image sensors, where a single photoelectron is accelerated directly into a CCD or CMOS sensor, allow wide-field imaging at extremely low light levels as they are sensitive enough to detect single photons. This technology allows the detection of up to hundreds or thousands of photon events per frame, depending on the sensor size, and photon event centroiding can be employed to recover resolution lost in the detection process. Unlike photon events from electron-multiplying sensors, the photon events from electron-bombarded sensors have a narrow, acceleration-voltage-dependent pulse height distribution. Thus a gain voltage sweep during exposure in an electron-bombarded sensor could allow photon arrival time determination from the pulse height with sub-frame exposure time resolution. We give a brief overview of our work with electron-bombarded pixel image sensor technology and recent developments in this field for single photon counting imaging, and examples of some applications. PMID:27136556

Response Time Analysis and Test of Protection System Instrument Channels for APR1400 and OPR1000

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

Lee, Chang Jae; Han, Seung; Yun, Jae Hee

2015-07-01

Safety limits are required to maintain the integrity of physical barriers designed to prevent the uncontrolled release of radioactive materials in nuclear power plants. The safety analysis establishes two critical constraints that include an analytical limit in terms of a measured or calculated variable, and a specific time after the analytical limit is reached to begin protective action. Keeping with the nuclear regulations and industry standards, satisfying these two requirements will ensure that the safety limit will not be exceeded during the design basis event, either an anticipated operational occurrence or a postulated accident. Various studies on the setpoint determinationmore » methodology for the safety-related instrumentation have been actively performed to ensure that the requirement of the analytical limit is satisfied. In particular, the protection setpoint methodology for the advanced power reactor 1400 (APP1400) and the optimized power reactor 1000 (OPR1000) has been recently developed to cover both the design basis event and the beyond design basis event. The developed setpoint methodology has also been quantitatively validated using specific computer programs and setpoint calculations. However, the safety of nuclear power plants cannot be fully guaranteed by satisfying the requirement of the analytical limit. In spite of the response time verification requirements of nuclear regulations and industry standards, it is hard to find the studies on the systematically integrated methodology regarding the response time evaluation. In cases of APR1400 and OPR1000, the response time analysis for the plant protection system is partially included in the setpoint calculation and the response time test is separately performed via the specific plant procedure. The test technique has a drawback which is the difficulty to demonstrate completeness of timing test. The analysis technique has also a demerit of resulting in extreme times that not actually possible. Thus, the establishment of the systematic response time evaluation methodology is needed to justify the conformance to the response time requirement used in the safety analysis. This paper proposes the response time evaluation methodology for APR1400 and OPR1000 using the combined analysis and test technique to confirm that the plant protection system can meet the analytical response time assumed in the safety analysis. In addition, the results of the quantitative evaluation performed for APR1400 and OPR1000 are presented in this paper. The proposed response time analysis technique consists of defining the response time requirement, determining the critical signal path for the trip parameter, allocating individual response time to each component on the signal path, and analyzing the total response time for the trip parameter, and demonstrates that the total analyzed response time does not exceed the response time requirement. The proposed response time test technique is composed of defining the response time requirement, determining the critical signal path for the trip parameter, determining the test method for each component on the signal path, performing the response time test, and demonstrates that the total test result does not exceed the response time requirement. The total response time should be tested in a single test that covers from the sensor to the final actuation device on the instrument channel. When the total channel is not tested in a single test, separate tests on groups of components or single components including the total instrument channel shall be combined to verify the total channel response. For APR1400 and OPR1000, the ramp test technique is used for the pressure and differential pressure transmitters and the step function testing technique is applied to the signal processing equipment and final actuation device. As a result, it can be demonstrated that the response time requirement is satisfied by the combined analysis and test technique. Therefore, the proposed methodology in this paper plays a crucial role in guaranteeing the safety of the nuclear power plants systematically satisfying one of two critical requirements from the safety analysis. (authors)« less

The New Multi-HAzard and MulTi-RIsK Assessment MethodS for Europe (MATRIX) Project - An overview of its major findings

NASA Astrophysics Data System (ADS)

Fleming, Kevin; Zschau, Jochen; Gasparini, Paolo

2014-05-01

Recent major natural disasters, such as the 2011 Tōhoku earthquake, tsunami and subsequent Fukushima nuclear accident, have raised awareness of the frequent and potentially far-reaching interconnections between natural hazards. Such interactions occur at the hazard level, where an initial hazard may trigger other events (e.g., an earthquake triggering a tsunami) or several events may occur concurrently (or nearly so), e.g., severe weather around the same time as an earthquake. Interactions also occur at the vulnerability level, where the initial event may make the affected community more susceptible to the negative consequences of another event (e.g., an earthquake weakens buildings, which are then damaged further by windstorms). There is also a temporal element involved, where changes in exposure may alter the total risk to a given area. In short, there is the likelihood that the total risk estimated when considering multiple hazard and risks and their interactions is greater than the sum of their individual parts. It is with these issues in mind that the European Commission, under their FP7 program, supported the New Multi-HAzard and MulTi-RIsK Assessment MethodS for Europe or MATRIX project (10.2010 to 12.2013). MATRIX set out to tackle multiple natural hazards (i.e., those of concern to Europe, namely earthquakes, landslides, volcanos, tsunamis, wild fires, storms and fluvial and coastal flooding) and risks within a common theoretical framework. The MATRIX work plan proceeded from an assessment of single-type risk methodologies (including how uncertainties should be treated), cascade effects within a multi-hazard environment, time-dependent vulnerability, decision making and support for multi-hazard mitigation and adaption, and an assessment of how the multi-hazard and risk viewpoint may be integrated into current decision making and risk mitigation programs, considering the existing single-hazard and risk focus. Three test sites were considered during the project: Naples, Cologne, and the French West Indies. In addition, a software platform, the MATRIX-Common IT sYstem (MATRIX-CITY), was developed to allow the evaluation of characteristic multi-hazard and risk scenarios in comparison to single-type analyses. This presentation therefore outlines the more significant outcomes of the project, in particular those dealing with the harmonization of single-type hazards, cascade event analysis, time-dependent vulnerability changes and the response of the disaster management community to the MATRIX point of view.

Effect of endogenous reference genes on digital PCR assessment of genetically engineered canola events.

PubMed

Demeke, Tigst; Eng, Monika

2018-05-01

Droplet digital PCR (ddPCR) has been used for absolute quantification of genetically engineered (GE) events. Absolute quantification of GE events by duplex ddPCR requires the use of appropriate primers and probes for target and reference gene sequences in order to accurately determine the amount of GE materials. Single copy reference genes are generally preferred for absolute quantification of GE events by ddPCR. Study has not been conducted on a comparison of reference genes for absolute quantification of GE canola events by ddPCR. The suitability of four endogenous reference sequences ( HMG-I/Y , FatA(A), CruA and Ccf) for absolute quantification of GE canola events by ddPCR was investigated. The effect of DNA extraction methods and DNA quality on the assessment of reference gene copy numbers was also investigated. ddPCR results were affected by the use of single vs. two copy reference genes. The single copy, FatA(A), reference gene was found to be stable and suitable for absolute quantification of GE canola events by ddPCR. For the copy numbers measured, the HMG-I/Y reference gene was less consistent than FatA(A) reference gene. The expected ddPCR values were underestimated when CruA and Ccf (two copy endogenous Cruciferin sequences) were used because of high number of copies. It is important to make an adjustment if two copy reference genes are used for ddPCR in order to obtain accurate results. On the other hand, real-time quantitative PCR results were not affected by the use of single vs. two copy reference genes.

A modified detector concept for SuperCDMS: The HiZIP and its charge performance

NASA Astrophysics Data System (ADS)

Page, Kedar Mohan

SuperCDMS is a leading direct dark matter search experiment which uses solid state detectors (Ge crystals) at milliKelvin temperatures to look for nuclear recoils caused by dark matter interactions in the detector. 'Weakly Interacting Massive Particles' (WIMPs) are the most favoured dark matter candidate particles. SuperCDMS, like many other direct dark matter search experiments, primarily looks for WIMPs. The measurement of both the ionization and the lattice vibration (phonon) signals from an interaction in the detector allow it to discriminate against electron recoils which are the main source of background for WIMP detection. SuperCDMS currently operates about 9 kgs worth of germanium detectors at the Soudan underground lab in northern Minnesota. In its next phase, SuperCDMS SNOLAB, it plans to use 100-200 kg of target mass (Ge) which would allow it to probe more of the interesting and unexplored parameter space for WIMPs predicted by theoretical models. The SuperCDMS Queen's Test Facility is a detector testing facility which is intended to serve detector testing and detector research and development purposes for the SuperCDMS experiment. A modified detector called the 'HiZIP' (Half-iZIP), which is reduced in complexity in comparison to the currently used iZIP (interleaved Z-sensitive Ionization and Phonon mediated) detectors, is studied in this thesis. The HiZIP detector design also serves to discriminate against background from multiple scatter events occurring close to the surfaces in a single detector. Studies carried out to compare the surface event leakage in the HiZIP detector using limited information from iZIP data taken at SuperCDMS test facility at UC Berkley produce a highly conservative upper limit of 5 out of 10,000 events at 90% confidence level. This upper limit is the best among many different HiZIP configurations that were investigated and is comparable to the upper limit calculated for an iZIP detector in the same way using the same data. A real HiZIP device operated at Queen's Test Facility produced an exposure limited 90% upper limit of about 1 in 100 events for surface event leakage. The data used in these studies contain true nuclear recoil events from cosmogenic and ambient neutrons. This background was not subtracted in the calculation of the upper limits stated above and hence they are highly conservative. A surface event source was produced by depositing lead-210 from radon exposure onto a copper plate. This source was then used to take data for a surface event discrimination study of the HiZIP detector operated at Queen's Test Facility. A study of the contribution of the noise from capacitive crosstalk between charge sensors in a HiZIP detector configuration was investigated, confirming the expectation that no significant drop in performance is to be expected due to this effect.

Clustering of trauma and associations with single and co-occurring depression and panic attack over twenty years.

PubMed

McCutcheon, Vivia V; Heath, Andrew C; Nelson, Elliot C; Bucholz, Kathleen K; Madden, Pamela A F; Martin, Nicholas G

2010-02-01

Individuals who experience one type of trauma often experience other types, yet few studies have examined the clustering of trauma. This study examines the clustering of traumatic events and associations of trauma with risk for single and co-occurring major depressive disorder (MDD) and panic attack for 20 years after first trauma. Lifetime histories of MDD, panic attack, and traumatic events were obtained from participants in an Australian twin sample. Latent class analysis was used to derive trauma classes based on each respondent's trauma history. Associations of the resulting classes and of parental alcohol problems and familial effects with risk for a first onset of single and co-occurring MDD and panic attack were examined from the year of first trauma to 20 years later. Traumatic events clustered into three distinct classes characterized by endorsement of little or no trauma, primarily nonassaultive, and primarily assaultive events. Individuals in the assaultive class were characterized by a younger age at first trauma, a greater number of traumatic events, and high rates of parental alcohol problems. Members of the assaultive trauma class had the strongest and most enduring risk for single and co-occurring lifetime MDD and panic attack. Assaultive trauma outweighed associations of familial effects and nonassaultive trauma with risk for 10 years following first trauma.

Single Low Dose Primaquine (0.25mg/kg) Does Not Cause Clinically Significant Haemolysis in G6PD Deficient Subjects

PubMed Central

Bancone, Germana; Chowwiwat, Nongnud; Somsakchaicharoen, Raweewan; Poodpanya, Lalita; Moo, Paw Khu; Gornsawun, Gornpan; Kajeechiwa, Ladda; Thwin, May Myo; Rakthinthong, Santisuk; Nosten, Suphak; Thinraow, Suradet; Nyo, Slight Naw; Ling, Clare L.; Wiladphaingern, Jacher; Kiricharoen, Naw Lily; Moore, Kerryn A.; White, Nicholas J.; Nosten, Francois

2016-01-01

Background Primaquine is the only drug consistently effective against mature gametocytes of Plasmodium falciparum. The transmission blocking dose of primaquine previously recommended was 0.75mg/kg (adult dose 45mg) but its deployment was limited because of concerns over haemolytic effects in patients with glucose-6-phosphate dehydrogenase (G6PD) deficiency. G6PD deficiency is an inherited X-linked enzymatic defect that affects an estimated 400 million people around the world with high frequencies (15–20%) in populations living in malarious areas. To reduce transmission in low transmission settings and facilitate elimination of P. falciparum, the World Health Organization now recommends adding a single dose of 0.25mg/kg (adult dose 15mg) to Artemisinin-based Combination Therapies (ACTs) without G6PD testing. Direct evidence of the safety of this low dose is lacking. Adverse events and haemoglobin variations after this treatment were assessed in both G6PD normal and deficient subjects in the context of targeted malaria elimination in a malaria endemic area on the North-Western Myanmar-Thailand border where prevalence of G6PD deficiency (Mahidol variant) approximates 15%. Methods and Findings The tolerability and safety of primaquine (single dose 0.25 mg base/kg) combined with dihydroartemisinin-piperaquine (DHA-PPQ) given three times at monthly intervals was assessed in 819 subjects. Haemoglobin concentrations were estimated over the six months preceding the ACT + primaquine rounds of mass drug administration. G6PD deficiency was assessed with a phenotypic test and genotyping was performed in male subjects with deficient phenotypes and in all females. Fractional haemoglobin changes in relation to G6PD phenotype and genotype and primaquine round were assessed using linear mixed-effects models. No adverse events related to primaquine were reported during the trial. Mean fractional haemoglobin changes after each primaquine treatment in G6PD deficient subjects (-5.0%, -4.2% and -4.7%) were greater than in G6PD normal subjects (0.3%, -0.8 and -1.7%) but were clinically insignificant. Fractional drops in haemoglobin concentration larger than 25% following single dose primaquine were observed in 1.8% of the population but were asymptomatic. Conclusions The single low dose (0.25mg/kg) of primaquine is clinically well tolerated and can be used safely without prior G6PD testing in populations with high prevalence of G6PD deficiency. The present evidence supports a broader use of low dose primaquine without G6PD testing for the treatment and elimination of falciparum malaria. Trial Registration ClinicalTrials.gov NCT01872702 PMID:27010542

Rapid diagnostic testing for community-acquired pneumonia: can innovative technology for clinical microbiology be exploited?

PubMed

Yu, Victor L; Stout, Janet E

2009-12-01

Two nonsynchronous events have affected the management of community-acquired pneumonia (CAP): spiraling empiricism for CAP and the "golden era" of clinical microbiology. The development of broad-spectrum antibiotics has led to widespread empiric use without ascertaining the etiology of the infecting microbe. Unfortunately, this approach clashes with the second event, which is the advent of molecular-based microbiology that can identify the causative pathogen rapidly at the point of care. The urinary antigen is a most effective rapid test that has allowed targeted therapy for Legionnaire disease at the point of care. The high specificity (> 90%) allows the clinician to administer appropriate anti-Legionella therapy based on a single rapid test; however, its low sensitivity (76%) means that a notable number of cases of Legionnaire disease will go undiagnosed if other tests, especially culture, are not performed. Further, culture for Legionella is not readily available. If a culture is not performed, epidemiologic identification of the source of the bacterium cannot be ascertained by molecular fingerprinting of the patient and the putative source strain. We recommend resurrection of the basic principles of infectious disease, which are to identify the microbial etiology of the infection and to use narrow, targeted antimicrobial therapy. To reduce antimicrobial overuse with subsequent antimicrobial resistance, these basic principles must be applied in concert with traditional and newer tests in the clinical microbiology laboratory.

Use of incidentally encoded memory from a single experience in cats.

PubMed

Takagi, Saho; Tsuzuki, Mana; Chijiiwa, Hitomi; Arahori, Minori; Watanabe, Arii; Saito, Atsuko; Fujita, Kazuo

2017-08-01

We examined whether cats could retrieve and utilize incidentally encoded information from a single past event in a simple food-exploration task previously used for dogs (Fujita et al., 2012). In Experiment 1, cats were led to four open, baited containers and allowed to eat from two of them (Exposure phase). After a 15-min delay during which the cats were absent and all containers were replaced with empty ones, the cats were unexpectedly returned to the room and allowed to explore the containers (Test phase). Although the cats' first choice of container to visit was random, they explored containers from which they had not previously eaten for longer than those from which they did previously eat. In the Exposure phase of Experiment 2, two containers held food, one held a nonedible object, and the fourth was empty. Cats were allowed to eat from one of them. In the post-delay Test phase, the cats first visited the remaining baited-uneaten container significantly more often than chance and they spent more time exploring this container. Because the cats' behavior in the Test phase cannot be explained by association of the container with a pleasant experience (eating), the results suggest that cats retrieved and utilized "what" and "where" information from an incidentally encoded memory from a single experience. Copyright © 2017 Elsevier B.V. All rights reserved.

Expanding Coherent Array Processing to Larger Apertures Using Empirical Matched Field Processing

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

Ringdal, F; Harris, D B; Kvaerna, T

2009-07-23

We have adapted matched field processing, a method developed in underwater acoustics to detect and locate targets, to classify transient seismic signals arising from mining explosions. Matched field processing, as we apply it, is an empirical technique, using observations of historic events to calibrate the amplitude and phase structure of wavefields incident upon an array aperture for particular repeating sources. The objective of this project is to determine how broadly applicable the method is and to understand the phenomena that control its performance. We obtained our original results in distinguishing events from ten mines in the Khibiny and Olenegorsk miningmore » districts of the Kola Peninsula, for which we had exceptional ground truth information. In a cross-validation test, some 98.2% of 549 explosions were correctly classified by originating mine using just the Pn observations (2.5-12.5 Hz) on the ARCES array at ranges from 350-410 kilometers. These results were achieved despite the fact that the mines are as closely spaced as 3 kilometers. Such classification performance is significantly better than predicted by the Rayleigh limit. Scattering phenomena account for the increased resolution, as we make clear in an analysis of the information carrying capacity of Pn under two alternative propagation scenarios: free-space propagation and propagation with realistic (actually measured) spatial covariance structure. The increase in information capacity over a wide band is captured by the matched field calibrations and used to separate explosions from very closely-spaced sources. In part, the improvement occurs because the calibrations enable coherent processing at frequencies above those normally considered coherent. We are investigating whether similar results can be expected in different regions, with apertures of increasing scale and for diffuse seismicity. We verified similar performance with the closely-spaced Zapolyarni mines, though discovered that it may be necessary to divide event populations from a single mine into identifiable subpopulations. For this purpose, we perform cluster analysis using matched field statistics calculated on pairs of individual events as a distance metric. In our initial work, calibrations were derived from ensembles of events ranging in number to more than 100. We are considering the performance now of matched field calibrations derived with many fewer events (even, as mentioned, individual events). Since these are high-variance estimates, we are testing the use of cross-channel, multitaper, spectral estimation methods to reduce the variance of calibrations and detection statistics derived from single-event observations. To test the applicability of the technique in a different tectonic region, we have obtained four years of continuous data from 4 Kazakh arrays and are extracting large numbers of event segments. Our initial results using 132 mining explosions recorded by the Makanchi array are similar to those obtained in the European Arctic. Matched field processing clearly separates the explosions from three closely-spaced mines located approximately 400 kilometers from the array, again using waveforms in a band (6-10 Hz) normally considered incoherent for this array. Having reproduced ARCES-type performance with another small aperture array, we have two additional objectives for matched field processing. We will attempt to extend matched field processing to larger apertures: a 200 km aperture (the KNET) and, if data permit, to an aperture comprised of several Kazakh arrays. We also will investigate the potential of developing matched field processing to roughly locate and classify natural seismicity, which is more diffuse than the concentrated sources of mining explosions that we have investigated to date.« less

Scaling multiblast craters: General approach and application to volcanic craters

NASA Astrophysics Data System (ADS)

Sonder, I.; Graettinger, A. H.; Valentine, G. A.

2015-09-01

Most volcanic explosions leave a crater in the surface around the center of the explosions. Such craters differ from products of single events like meteorite impacts or those produced by military testing because they typically result from multiple, rather than single, explosions. Here we analyze the evolution of experimental craters that were created by several detonations of chemical explosives in layered aggregates. An empirical relationship for the scaled crater radius as a function of scaled explosion depth for single blasts in flat test beds is derived from experimental data, which differs from existing relations and has better applicability for deep blasts. A method to calculate an effective explosion depth for nonflat topography (e.g., for explosions below existing craters) is derived, showing how multiblast crater sizes differ from the single-blast case: Sizes of natural caters (radii and volumes) are not characteristic of the number of explosions, nor therefore of the total acting energy, that formed a crater. Also, the crater size is not simply related to the largest explosion in a sequence but depends upon that explosion and the energy of that single blast and on the cumulative energy of all blasts that formed a crater. The two energies can be combined to form an effective number of explosions that is characteristic for the crater evolution. The multiblast crater size evolution has implications on the estimates of volcanic eruption energies, indicating that it is not correct to estimate explosion energy from crater size using previously published relationships that were derived for single-blast cases.

Single CA3 pyramidal cells trigger sharp waves in vitro by exciting interneurones.

PubMed

Bazelot, Michaël; Teleńczuk, Maria T; Miles, Richard

2016-05-15

The CA3 hippocampal region generates sharp waves (SPW), a population activity associated with neuronal representations. The synaptic mechanisms responsible for the generation of these events still require clarification. Using slices maintained in an interface chamber, we found that the firing of single CA3 pyramidal cells triggers SPW like events at short latencies, similar to those for the induction of firing in interneurons. Multi-electrode records from the CA3 stratum pyramidale showed that pyramidal cells triggered events consisting of putative interneuron spikes followed by field IPSPs. SPW fields consisted of a repetition of these events at intervals of 4-8 ms. Although many properties of induced and spontaneous SPWs were similar, the triggered events tended to be initiated close to the stimulated cell. These data show that the initiation of SPWs in vitro is mediated via pyramidal cell synapses that excite interneurons. They do not indicate why interneuron firing is repeated during a SPW. Sharp waves (SPWs) are a hippocampal population activity that has been linked to neuronal representations. We show that SPWs in the CA3 region of rat hippocampal slices can be triggered by the firing of single pyramidal cells. Single action potentials in almost one-third of pyramidal cells initiated SPWs at latencies of 2-5 ms with probabilities of 0.07-0.76. Initiating pyramidal cells evoked field IPSPs (fIPSPs) at similar latencies when SPWs were not initiated. Similar spatial profiles for fIPSPs and middle components of SPWs suggested that SPW fields reflect repeated fIPSPs. Multiple extracellular records showed that the initiated SPWs tended to start near the stimulated pyramidal cell, whereas spontaneous SPWs could emerge at multiple sites. Single pyramidal cells could initiate two to six field IPSPs with distinct amplitude distributions, typically preceeded by a short-duration extracellular action potential. Comparison of these initiated fields with spontaneously occurring inhibitory field motifs allowed us to identify firing in different interneurones during the spread of SPWs. Propagation away from an initiating pyramidal cell was typically associated with the recruitment of interneurones and field IPSPs that were not activated by the stimulated pyramidal cell. SPW fields initiated by single cells were less variable than spontaneous events, suggesting that more stereotyped neuronal ensembles were activated, although neither the spatial profiles of fields, nor the identities of interneurone firing were identical for initiated events. The effects of single pyramidal cell on network events are thus mediated by different sequences of interneurone firing. © 2016 The Authors. The Journal of Physiology © 2016 The Physiological Society.

A Large-scale Search for Evidence of Quasi-periodic Pulsations in Solar Flares

NASA Astrophysics Data System (ADS)

Inglis, A. R.; Ireland, J.; Dennis, B. R.; Hayes, L.; Gallagher, P.

2016-12-01

The nature of quasi-periodic pulsations (QPP) in solar flares is poorly constrained, and critically the general prevalence of such signals in solar flares is unknown. Therefore, we perform a large-scale search for evidence of signals consistent with QPP in solar flares, focusing on the 1-300 s timescale. We analyze 675 M- and X-class flares observed by the Geostationary Operational Environmental Satellite (GOES) series in 1-8 Å soft X-rays between 2011 February 1 and 2015 December 31. Additionally, over the same era we analyze Fermi/Gamma-ray Burst Monitor (GBM) 15-25 keV X-ray data for each of these flares associated with a Fermi/GBM solar flare trigger, a total of 261 events. Using a model comparison method, we determine whether there is evidence for a substantial enhancement in the Fourier power spectrum that may be consistent with a QPP signature, based on three tested models; a power-law plus a constant, a broken power-law plus constant, and a power-law-plus-constant with an additional QPP signature component. From this, we determine that ˜30% of GOES events and ˜8% of Fermi/GBM events show strong signatures consistent with classical interpretations of QPP. For the remaining events either two or more tested models cannot be strongly distinguished from each other, or the events are well-described by single power-law or broken power-law Fourier power spectra. For both instruments, a preferred characteristic timescale of ˜5-30 s was found in the QPP-like events, with no dependence on flare magnitude in either GOES or GBM data. We also show that individual events in the sample show similar characteristic timescales in both GBM and GOES data sets. We discuss the implications of these results for our understanding of solar flares and possible QPP mechanisms.

A Large-Scale Search for Evidence of Quasi-Periodic Pulsations in Solar Flares

NASA Technical Reports Server (NTRS)

Inglis, A. R.; Ireland, J.; Dennis, B. R..; Hayes, L.; Gallagher, P.

2016-01-01

The nature of quasi-periodic pulsations (QPP) in solar flares is poorly constrained, and critically the general prevalence of such signals in solar flares is unknown. Therefore, we perform a large-scale search for evidence of signals consistent with QPP in solar flares, focusing on the 1300 s timescale. We analyze 675 M- and X-class flares observed by the Geostationary Operational Environmental Satellite (GOES) series in 18 soft X-rays between 2011 February 1 and 2015 December 31. Additionally, over the same era we analyze Fermi/Gamma-ray Burst Monitor (GBM) 1525 keV X-ray data for each of these flares associated with a Fermi/GBM solar flare trigger, a total of 261 events. Using a model comparison method, we determine whether there is evidence for a substantial enhancement in the Fourier power spectrum that may be consistent with a QPP signature, based on three tested models; a power-law plus a constant, a broken power-law plus constant, and a power-law-plus-constant with an additional QPP signature component. From this, we determine that approx. 30% of GOES events and approx. 8% of Fermi/GBM events show strong signatures consistent with classical interpretations of QPP. For the remaining events either two or more tested models cannot be strongly distinguished from each other, or the events are well-described by single power-law or broken power-law Fourier power spectra. For both instruments, a preferred characteristic time-scale of approx. 5-30 s was found in the QPP-like events, with no dependence on flare magnitude in either GOES or GBM data. We also show that individual events in the sample show similar characteristic time-scales in both GBM and GOES data sets. We discuss the implications of these results for our understanding of solar flares and possible QPP mechanisms.

A LARGE-SCALE SEARCH FOR EVIDENCE OF QUASI-PERIODIC PULSATIONS IN SOLAR FLARES

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

Inglis, A. R.; Ireland, J.; Dennis, B. R.

The nature of quasi-periodic pulsations (QPP) in solar flares is poorly constrained, and critically the general prevalence of such signals in solar flares is unknown. Therefore, we perform a large-scale search for evidence of signals consistent with QPP in solar flares, focusing on the 1–300 s timescale. We analyze 675 M- and X-class flares observed by the Geostationary Operational Environmental Satellite (GOES) series in 1–8 Å soft X-rays between 2011 February 1 and 2015 December 31. Additionally, over the same era we analyze Fermi /Gamma-ray Burst Monitor (GBM) 15–25 keV X-ray data for each of these flares associated with amore » Fermi /GBM solar flare trigger, a total of 261 events. Using a model comparison method, we determine whether there is evidence for a substantial enhancement in the Fourier power spectrum that may be consistent with a QPP signature, based on three tested models; a power-law plus a constant, a broken power-law plus constant, and a power-law-plus-constant with an additional QPP signature component. From this, we determine that ∼30% of GOES events and ∼8% of Fermi /GBM events show strong signatures consistent with classical interpretations of QPP. For the remaining events either two or more tested models cannot be strongly distinguished from each other, or the events are well-described by single power-law or broken power-law Fourier power spectra. For both instruments, a preferred characteristic timescale of ∼5–30 s was found in the QPP-like events, with no dependence on flare magnitude in either GOES or GBM data. We also show that individual events in the sample show similar characteristic timescales in both GBM and GOES data sets. We discuss the implications of these results for our understanding of solar flares and possible QPP mechanisms.« less

A new method for using Cf-252 in SEU testing

NASA Astrophysics Data System (ADS)

Costantine, A.; Howard, J. W.; Becker, M.; Block, R. C.; Smith, L. S.; Soli, G. A.; Stauber, M. C.

1990-12-01

A system using Cf-252 and associated nuclear instrumentation has determined the single-event upset (SEU) cross section versus linear energy transfer (LET) curve for several 2K x 8 static random access memories (SRAMs). The Cf-252 fission fragments pass through a thin-film organic scintillator detector (TFD) on the way to the device under test (DUT). The TFD provides energy information for each transiting fragment. Data analysis provides the energy of the individual ion responsible for each SEU; thus, separate upset cross sections can be developed for different energy and mass regions of the californium spectrum. This californium-based device is quite small and fits onto a bench top. It provides a convenient and inexpensive supplement or alternative to accelerator and high-altitude/space SEU testing.

Design and qualification of the SEU/TD Radiation Monitor chip

NASA Technical Reports Server (NTRS)

Buehler, Martin G.; Blaes, Brent R.; Soli, George A.; Zamani, Nasser; Hicks, Kenneth A.

1992-01-01

This report describes the design, fabrication, and testing of the Single-Event Upset/Total Dose (SEU/TD) Radiation Monitor chip. The Radiation Monitor is scheduled to fly on the Mid-Course Space Experiment Satellite (MSX). The Radiation Monitor chip consists of a custom-designed 4-bit SRAM for heavy ion detection and three MOSFET's for monitoring total dose. In addition the Radiation Monitor chip was tested along with three diagnostic chips: the processor monitor and the reliability and fault chips. These chips revealed the quality of the CMOS fabrication process. The SEU/TD Radiation Monitor chip had an initial functional yield of 94.6 percent. Forty-three (43) SEU SRAM's and 14 Total Dose MOSFET's passed the hermeticity and final electrical tests and were delivered to LL.