Triggered Source Research Articles

Coordination between innate immune cells, type I IFNs and IRF5 drives SLE pathogenesis

Systemic lupus erythematosus (SLE) is a complex autoimmune disease which affects multiple organs. The type I interferon (IFN) gene signature and circulating autoantibodies are hallmarks of SLE. Plasmacytoid dendritic cells (pDCs) are considered the main producers of type I IFN and production is modulated by multiple other immune cell types. In SLE, essentially every immune cell type is dysregulated and aberrant deregulation is thought to be due, in part, to direct or indirect exposure to IFN. Genetic variants within or around the transcription factor interferon regulatory factor 5 (IRF5) associate with SLE risk. Elevated IFNα activity was detected in the sera of SLE patients carrying IRF5 risk polymorphisms who were positive for either anti-RNA binding protein (anti-RBP) or anti-double-stranded DNA (anti-dsDNA) autoantibodies. Neutrophils are also an important source of type I IFNs and are found in abundance in human blood. Neutrophil extracellular traps (NETs) are considered a potential source of antigenic trigger in SLE that can lead to type I IFN gene induction, as well as increased autoantibody production. In this review, we will focus on immune cell types that produce type I IFNs and/or are affected by type I IFN in SLE. In addition, we will discuss potential inducers of endogenous type I IFN production in SLE. Last, we will postulate how the different immune cell populations may be affected by an IRF5-SLE risk haplotype.

Near-Unity Indistinguishability Single Photon Source for Large-Scale Integrated Quantum Optics.

Integrated single photon sources are key building blocks for realizing scalable devices for quantum information processing. For such applications highly coherent and indistinguishable single photons on a chip are required. Here we report on a triggered resonance fluorescence single photon source based on In(Ga)As/GaAs quantum dots coupled to single- and multimode ridge waveguides. We demonstrate the generation of highly linearly polarized resonance fluorescence photons with 99.1% (96.0%) single photon purity and 97.5% (95.0%) indistinguishability in case of multimode (single mode) waveguide devices fulfilling the strict requirements imposed by multi-interferometric quantum optics applications. Our integrated triggered single photon source can be readily scaled up, promising a realistic pathway for on-chip linear optical quantum simulation, quantum computation, and quantum networks.

Compact electromagnetic pulse forming system based on the trigger vacuum switch

Electromagnetic pulse forming (EMPF) is a type of electromagnetic manufacturing technology which produces a powerful Lorentz force to change the shape or form of a work piece. In this paper, a 6.75-kJ/15-kV compact EMPF system based on the RVU-43 trigger vacuum switch is designed, fabricated and tested. The RVU-43 has good performance in a high-voltage discharge process that can withstand 25 kV and conduct 400 kA. A trigger source for the RVU-43 based on a pulse transformer and a solid-state switch can generate a rectangular trigger pulse of an adjustable amplitude of 0–5 kV and a pulse width of 0–5 μs. A simulation model is built in PSPICE to analyze the parameters affecting the performance of the EMPF. The results show that the system inductance can affect the peak current and the rise time, while the system resistance can affect the peak current. Connecting the capacitors in parallel, reducing the discharge loop area and designing a single-turn forming coil with a 30-degree field shaper are used to reduce the influence of the system parameters. The results of experiments for changing the shape of an aluminum alloy tube suggest that the EMPF system can form and process the metal tube successfully.

Recent advances in compact repetitive high-power Marx generators

AbstractThis paper introduces recent activities on Marx-based compact repetitive pulsed power generators at the Institute of Applied Electronics (IAE), China Academy of Engineering Physics (CAEP), over the period 2010–2018. A characteristic feature of the generators described is the use of a simplified bipolar charged Marx circuit, in which the normal isolation resistors or inductors to ground are removed to make the circuit simpler. Several pulse-forming modules developed to generate a 100 ns square wave output are introduced, including thin-film dielectric lines of different structures, a pulse-forming line based on a Printed Circuit Board, and non-uniform pulse-forming networks. A compact repetitive three-electrode spark gap switch with low-jitter, high-voltage, and high-current was developed and is used in the generators. A positive and negative series resonant constant current power supply with high precision and high power is introduced. As an important part of the repetitive pulse power generator, a lower jitter pulse trigger source is introduced. Several typical high-power repetitive pulsed power generators developed at IAE are introduced including a 30 GW low-impedance Marx generator, a compact square-wave pulse generator based on Kapton-film dielectric Blumlein line, a 20 GW high pulse-energy repetitive PFN-Marx generator, and a coaxial Marx generator based on ceramic capacitors. The research of key technologies and their development status are discussed, which can provide a reference for the future development and application of miniaturization of compact and repetitive Marx generators.

Paleoseismic event recorded in the Upper Cretaceous Nenjiang Formation in southeastern area of the Songliao Basin (NE China)

The Yaojiachezhan (YJCZ) section and NGN1, Zk3389 and SK1-S wells, which are located in the southeastern part of the Songliao Basin, NE China, were used to analyse paleoseismic events recorded in the Upper Cretaceous first member of the Nenjiang Formation. Two representative seismic sequences are recognised in these lacustrine deposits. The seismic sequence observed in the YJCZ section, from the base to top, includes step micro-faulting, seismic fissures, liquefaction sandstone veins, brecelated structures, liquefied fold-deformed laminations and sand pillow structures. Whereas in NGN1 core, from the base to top, includes micro-faulting, seismic fissures, sand pillow structures, liquefied fold-deformed laminations and liquefaction sandstone veins. These two seismic sequences together reflect the processes resulting from a strong seismic event from initiation to culmination, then decline and recession. The occurrence of brecciated structures reflects the earthquake magnitude in the YJCZ section area probably reached M7.5, while liquefied fold-deformed laminations in the NGN1 core area reflects an earthquake magnitude of M7.0. Empirical relations between earthquake magnitude and the maximum distance of liquefaction deformation structure sites from the epicentres show that the longest distance between the earthquake source area for the YJCZ section and NGN1 well are <100 km, whereas the distance for the Zk3389 and SK1-S wells is >100 km. The trigger source area for this paleoseismic event is most likely the Yilan-Yitong Fault, meaning that the Yilan-Yitong Fault was active during the deposition of the first member of the Nenjiang Formation.

Host galaxy effects in the SUSY model for Supernovae Ia

For more than 40 years virtually all work on the theory of type Ia Supernovae (SN Ia) has assumed that these explosions were due to the transfer of mass to a degenerate star from a partner in a binary system. In these binary models, when the mass of one partner closely approaches the Chandrasekhar maximum for a stable degenerate system, fusion can be initiated and the star explodes. However, a number of long-standing nagging problems and the inability of any specific binary model to fit any significant fraction of SN Ia events suggest that fusion could instead be triggered by a phase transition in a sub-Chandrasekhar white dwarf star. It is possible that remarkable host galaxy effects not considered in previous work on phase transition models could point to a specific source of the supernova trigger. Performing a least [Formula: see text] fit to the delay time distribution to fix parameters, we give predictions from the SUSY phase transition model for the host galaxy effects. In addition we discuss a SUSY insight into the Phillips relation which is basic to the cosmological importance of the type Ia supernovae.

Asynchronous optical sampling data-acquisition trigger-signal derived from pulse coherence coincidence.

We propose a data acquisition trigger signal, suitable for free-space, asynchronous optical sampling (ASOPS) systems, based on Laser Pulse Coherence (LPC). At 1 GHz laser pulse repetition frequencies and higher, this method becomes an attractive alternative to established techniques, as it lacks the necessity of high peak pulse intensity, maximising the total laser power available for measurements. Additional advantages are the large unamplified signal generated, ease of initial alignment, and greatly reduced beam pointing stability errors. Employing a LPC trigger source, we realise a sub 30 fs trigger timing error for our ASOPS system.

Directly Visualizing Tactile Perception and Ultrasensitive Tactile Sensors by Utilizing Body‐Enhanced Induction of Ambient Electromagnetic Waves

AbstractTactile recognition is a critical technology for many applications. Here, it is found that the ambient electromagnetic signal, which is usually regarded as electromagnetic noise, can be a good triggering source to realize tactile detection. A circuit consisting of two light emitting diodes (LEDs) is designed as sensor unit and human contact can amplify the electrostatic signal induced by electromagnetic wave in this circuit, which enhances the brightness of the LEDs. Hence, visualizing tactile perception can be achieved based on this strategy. Accordingly, a stretchable and semi‐transparent sensor matrix is established for mapping detailed contact positions, on which the contact force can be smaller than 0.001 N. The detection and the visualization of sliding trajectory and pressure change are also demonstrated by using this sensory method, indicating its good applicability for different purposes. Electromagnetic wave universally exists in the working places and tactile sensors based on this strategy can be possibly applied to many fields such as factory automation, intelligent robotics, human–machine interaction, etc.

Persistent left superior vena cava as an arrhythmogenic source in atrial fibrillation: results from a multicenter experience.

Persistent left superior vena cava (PLSVC) is one of the most frequently reported congenital anomalies and may be an important source of trigger of atrial fibrillation (AF). This was a multicenter retrospective experience including 28 patients with PLSVC who were referred for catheter ablation for drug-refractory symptomatic AF. Pulmonary vein and PLSVC isolation were performed (3.5-mm open irrigated tip ablation catheter at maximum power of 20W, maximum temperature 43°C with flow rate of 17ml/min). Clinical outcomes such as complications and long-term freedom from AF were measured. The mean age of the population was 61 ± 8years, 21% were females, and AF duration was 60 ± 33months. Sixty-one percent paroxysmal AF (17/28), 25% (7/28) persistent AF, and 14% (4/28) had long-standing persistent AF. There were no major complications that required any intervention. PLSVC isolation was achieved in 96% (27/28). Freedom from AF at 1year without antiarrhythmic drugs was seen in 75% (21/28) of patients. In PLSVC patients with AF, segmental isolation of PLSVC appears to be feasible and safe and can translate into favorable clinical outcomes.

Revised and extended analysis of the third spectrum of silver: Ag III

The spectrum of doubly ionized silver (Ag III) having the ground configuration 4p64d9 has been investigated. The silver spectra were recorded on a 3-m normal incidence vacuum spectrograph at St. Francis Xavier University, Antigonish (Canada) using a triggered spark source. Theoretical predictions based on the Hartree–Fock method were made using superposition of interacting configurations and relativistic corrections. For proper interpretation of configuration interaction, the configurations 4p6[4d9, 4d8ns (n=5–9), 4d8nd (n = 5–9), 4d8ng (n=5–7), 4d75s2 and 4d75p2] and 4p54d10, 4p6[4d8np (n=5–7), 4d8nf (n = 4–6), 4d8nh (n = 6–7), 4d75s5p and 4d75s4f] were incorporated in the even and odd parity systems, respectively. The previous analyses were checked thoroughly; five levels of 4d85p were revised and two configurations, viz., 4d85d and 4d86s have been investigated for the first time. A total of 124 energy levels were established belonging to the configurations 4p6[4d9+4d8(5s + 6s + 5p + 5d)], among which 64 levels of 4p64d8(5d + 6s) were newly established. Least squares fitting parametric calculations were carried out to interpret the observed energy level structure. The observed energy levels were optimized to fit the measured wavelengths.

A stable wavelength-tunable triggered source of single photons and cascaded photon pairs at the telecom C-band

The implementation of fiber-based long-range quantum communication requires tunable sources of single photons at the telecom C-band. Stable and easy-to-implement wavelength-tunability of individual sources is crucial to (i) bring remote sources into resonance, (ii) define a wavelength standard, and (iii) ensure scalability to operate a quantum repeater. So far, the most promising sources for true, telecom single photons are semiconductor quantum dots, due to their ability to deterministically and reliably emit single and entangled photons. However, the required wavelength-tunability is hard to attain. Here, we show a stable wavelength-tunable quantum light source by integrating strain-released InAs quantum dots on piezoelectric substrates. We present triggered single-photon emission at 1.55 μm with a multi-photon emission probability as low as 0.097, as well as photon pair emission from the radiative biexciton–exciton cascade. We achieve a tuning range of 0.25 nm which will allow us to spectrally overlap remote quantum dots or tuning distant quantum dots into resonance with quantum memories. This opens up realistic avenues for the implementation of photonic quantum information processing applications at telecom wavelengths.

Development of a tagged source of Pb-206 nuclei

There is a particular class of unavoidable backgrounds that plague low-background experiments and rare event searches, particularly those searching for nuclear recoil event signatures: decaying daughters of the 238U nuclear decay chain, which result from radon plate-out on detector materials. One such daughter isotope, 210Po, undergoes α-decay and produces a recoiling 103 keV 206Pb nucleus. To characterize this important background in the context of noble element detectors, we have implemented a triggered source for these 206Pb recoils in a dual-phase xenon time projection chamber (Xe TPC) within the Davis Xenon R&D testbed system (DAX). By adhering 210Po to the surface of a PIN diode and electrically floating the diode on the cathode of the TPC, we tag the α signals produced in the PIN diode and trigger on the correlated nuclear recoils in the liquid xenon (LXe). We discuss our methods for 210Po deposition, electronic readout of the PIN diode signals at high voltage, and analysis methods for event selection.

Design of an automated and intelligent rock breaker: case of Platinum mine platinum company in Zimbabwe

In this system a camera is put overhead of the rock breaker for capturing local images at high spatial resolution. The grizzly is made of a bleach material so that the image background does not portray as ore particles. As the ore sample is being tipped by loader or Load Hull Dumper (LHD) from one end to another, images are captured by the high speed overhead (Charge-Coupled Device) CCD camera. As the images are acquired they are sent into a certain directory in the Programmable Logic Controller (PLC). The trigger configurations for the camera are set to hardware trigger with a falling edge condition using the timer trigger source (but manual trigger was used in simulation). When the CCD camera detects the position of ore on the grizzly the PLC will give a command signal to the motion control that is servo controller to move the boom to the required position for hammering.

Triggered high-purity telecom-wavelength single-photon generation from p-shell-driven InGaAs/GaAs quantum dot.

We report on the experimental demonstration of triggered single-photon emission at the telecom O-band from In(Ga)As/GaAs quantum dots (QDs) grown by metal-organic vapor-phase epitaxy. Micro-photoluminescence excitation experiments allowed us to identify the p-shell excitonic states in agreement with high excitation photoluminescence on the ensemble of QDs. Hereby we drive an O-band-emitting GaAs-based QD into the p-shell states to get a triggered single photon source of high purity. Applying pulsed p-shell resonant excitation results in strong suppression of multiphoton events evidenced by the as measured value of the second-order correlation function at zero delay of 0.03 (and ~0.005 after background correction).

Abstract 21164: New Pulmonary Vein Derived Theory of Atrial Fibrillation

Introduction: Pulmonary veins (PV) is a major source of triggers for AF. However, the mechanism underlying the rapid firing of PV muscle sleeve is not fully understood. Hypothesis: AF is related to the compensatory increase in PV load in patients with pneumonectomy. Methods: A cohort of 128 patients were recruited and assigned to three groups, group 1: patients with left-sided pneumonectomy (N = 47), group 2: patients with right sided pneumonectomy (N = 21), and control group: patients with paroxysmal AF (N = 60). All patients underwent echocardiography and CT scan preoperatively; PVI was performed in three groups; 24-hour Holter monitoring was performed during 1-year of follow-up. Results: All patients in group 1 and 2 had paroxysmal AF, occurring decades after pneumonectomy. No inter-group differences in left atrial diameter were seen. The average diameter of LSPV (17.2±1.4 mm) and LIPV (14.7±1.2 mm) in group 1 was larger than those in control group (13.6±1.0 mm and 9.9±0.9 mm, P&lt;0.01). The diameter of RSPV and RIPV in group 2 (15.1±1.3 mm and 14.5±1.1 mm) and control group (13.2±1.3 mm and 10.2±1.2 mm) also showed significant differences (P&lt;0.01). Electrical activity in group 1 and 2 could be recorded in all the PV stumps. After isolation of contralateral PV, AF was terminated in 91.5% and 85.7% of patients in group 1 and group 2. During follow-up, the incidence of AF episodes was not significantly different among three groups. Conclusions: the PV-derived mechanism of AF depends on a compensative increase in contralateral PV load in patients that have undergone pneumonectomy, and partial PV mediated AF is hard to progress into persistent state.

Light Detection System simulations for SBND

The Liquid Argon Time Projection Chamber (LArTPC) detectors are becoming the state of the art for neutrino detection and therefore play a major part in the US-based neutrino programme. LArTPCs detect primarily the ionization charge, but argon is also an excellent scintillator generating on the order of 40 000 photons per MeV of deposited energy. Until recently the scintillation light in liquid argon neutrino detectors has been mostly used as a source of trigger for beam and off-beam events, but it carries information that could be used to enhance the physics capabilities of these detectors. Newly designed short baseline experiments, in particular the Short Baseline Near-Detector - SBND, are putting significantly more focus on exploiting and developing the scintillation light capabilities of LArTPCs. This document will describe the simulation constructed for the SBND experiment to develop new applications of using scintillation light in LArTPCs that would take them beyond the state of the art of current liquid-argon detectors. We will discuss the application of scintillation light to determine timing, position and energy of neutrino events in liquid argon.

Pulsed characterization of a UV LED for pulsed power applications on a silicon carbide photoconductive semiconductor switch.

The electrical and optical characteristics of a high-power UV light emitting diode (LED) (365 nm wavelength) were evaluated under pulsed operating conditions at current amplitudes several orders of magnitude beyond the LED's manufacturer specifications. Geared towards triggering of photoconductive semiconductor switches (PCSSs) for pulsed power applications, measurements were made over varying pulse widths (25 ns-100 μs), current (0 A-250 A), and repetition rates (single shot-5 MHz). The LED forward voltage was observed to increase linearly with increasing current (∼3.5 V-53 V) and decrease with increasing pulse widths. The peak optical power observed was >30 W, and a maximum system efficiency of 23% was achieved. The evaluated LED and auxiliary hardware were successfully used as the optical trigger source for a 4H-SiC PCSS. The lowest measured on-resistance of SiC was approximately 67 kΩ.

Multi-year predictability of climate, drought, and wildfire in southwestern North America

Past severe droughts over North America have led to massive water shortages and increases in wildfire frequency. Triggering sources for multi-year droughts in this region include randomly occurring atmospheric blocking patterns, ocean impacts on atmospheric circulation, and climate’s response to anthropogenic radiative forcings. A combination of these sources translates into a difficulty to predict the onset and length of such droughts on multi-year timescales. Here we present results from a new multi-year dynamical prediction system that exhibits a high degree of skill in forecasting wildfire probabilities and drought for 10–23 and 10–45 months lead time, which extends far beyond the current seasonal prediction activities for southwestern North America. Using a state-of-the-art earth system model along with 3-dimensional ocean data assimilation and by prescribing the external radiative forcings, this system simulates the observed low-frequency variability of precipitation, soil water, and wildfire probabilities in close agreement with observational records and reanalysis data. The underlying source of multi-year predictability can be traced back to variations of the Atlantic/Pacific sea surface temperature gradient, external radiative forcings, and the low-pass filtering characteristics of soils.

Front roughening of flames in discrete media.

The morphology of flame fronts propagating in reactive systems composed of randomly positioned, pointlike sources is studied. The solution of the temperature field and the initiation of new sources is implemented using the superposition of the Green's function for the diffusion equation, eliminating the need to use finite-difference approximations. The heat released from triggered sources diffuses outward from each source, activating new sources and enabling a mechanism of flame propagation. Systems of 40000 sources in a 200×200 two-dimensional domain were tracked using computer simulations, and statistical ensembles of 120 realizations of each system were averaged to determine the statistical properties of the flame fronts. The reactive system of sources is parameterized by two nondimensional values: the heat release time (normalized by interparticle diffusion time) and the ignition temperature (normalized by adiabatic flame temperature). These two parameters were systematically varied for different simulations to investigate their influence on front propagation. For sufficiently fast heat release and low ignition temperature, the front roughness [defined as the root mean square deviation of the ignition temperature contour from the average flame position] grew following a power-law dependence that was in excellent agreement with the Kardar-Parisi-Zhang (KPZ) universality class (β=1/3). As the reaction time was increased, lower values of the roughening exponent were observed, and at a sufficiently great value of reaction time, reversion to a steady, constant-width thermal flame was observed that matched the solution from classical combustion theory. Deviation away from KPZ scaling was also observed as the ignition temperature was increased. The features of this system that permit it to exhibit both KPZ and non-KPZ scaling are discussed.

The Third Spectrum of Indium: In III

The present investigation reports on the extended study of the third spectrum of indium (In III). This spectrum was previously analyzed in many articles, but, nevertheless, this study represents a significant extension of the previous analyses. The main new contribution is connected to the observation of transitions involving core-excited configurations. Previous data are critically evaluated and in some cases are corrected. The spectra were recorded on 3-m as well as on 10.7-m normal incidence spectrographs using a triggered spark source. Theoretical calculations were made with Cowan’s code. The analysis results in the identifications of 70 spectral lines and determination of 24 new energy levels. In addition, the manuscript represents a compilation of all presently available data on In III.