Multiple Bursts Research Articles

Extreme and rapid bursts of functional adaptations shape bite force in amniotes.

Adaptation is the fundamental driver of functional and biomechanical evolution. Accordingly, the states of biomechanical traits (absolute or relative trait values) have long been used as proxies for adaptations in response to direct selection. However, ignoring evolutionary history, in particular ancestry, passage of time and the rate of evolution, can be misleading. Here, we apply a recently developed phylogenetic statistical approach using significant rate shifts to detect instances of exceptional rates of adaptive changes in bite force in a large group of terrestrial vertebrates, the amniotes. Our results show that bite force in amniotes evolved through multiple bursts of exceptional rates of adaptive changes, whereby whole groups-including Darwin's finches, maniraptoran dinosaurs (group of non-avian dinosaurs including birds), anthropoids and hominins (fossil and modern humans)-experienced significant rate increases compared to the background rate. However, in most parts of the amniote tree of life, we find no exceptional rate increases, indicating that coevolution with body size was primarily responsible for the patterns observed in bite force. Our approach represents a template for future studies in functional morphology and biomechanics, where exceptional rates of adaptive changes can be quantified and potentially linked to specific ecological factors underpinning major evolutionary radiations.

Bowel Sounds Identification and Migrating Motor Complex Detection with Low-Cost Piezoelectric Acoustic Sensing Device.

Interpretation of bowel sounds (BS) provides a convenient and non-invasive technique to aid in the diagnosis of gastrointestinal (GI) conditions. However, the approach’s potential is limited by variation between BS and their irregular occurrence. A short, manual auscultation is sufficient to aid in diagnosis of only a few conditions. A longer recording has the potential to unlock additional understanding of GI physiology and clinical utility. In this paper, a low-cost and straightforward piezoelectric acoustic sensing device was designed and used for long BS recordings. The migrating motor complex (MMC) cycle was detected using this device and the sound index as the biomarker for MMC phases. This cycle of recurring motility is typically measured using expensive and invasive equipment. We also used our recordings to develop an improved categorization system for BS. Five different types of BS were extracted: the single burst, multiple bursts, continuous random sound, harmonic sound, and their combination. Their acoustic characteristics and distribution are described. The quantities of different BS during two-hour recordings varied considerably from person to person, while the proportions of different types were consistent. The sensing devices provide a useful tool for MMC detection and study of GI physiology and function.

Experimental Study of Gas Cooling During Firefighting Operations

Gas cooling is a technique used by firefighters to reduce the dangers posed by the hot smoke in enclosure fires and, to thereby approach a fire while keeping their escape route safe. The technique includes bursts of water from a fog nozzle producing small droplets into the hot gases. The purpose of this work was to experimentally investigate the effects of gas cooling. A total of 44 tests were conducted in an 1800 × 1200 × 1200 mm room with an added fire room sizing 1200 × 760 × 1200 mm. A gas burner with a RHR of approximately 90 kW was used as a heat source. Four different nozzles were used, differing in droplet size, flow, and spray pattern. Also, reach, number of bursts and open time of the nozzles varied between tests. In this paper, six of the test with the most important and pronounced results were used for comparison. Conclusions from the tests included that nozzles producing droplets with a median diameter of approximately 500 µm delivered in multiple short burst with time in between bursts kept as short as possible were most effective for gas cooling. However, overall in this experimental setup taking all droplets sizes into consideration, a single longer burst performed slightly better than several short bursts as a similar temperature reduction is achieved in 1/3rd of the time of 5 short bursts and gases are cooled over a larger part of the room. The volume of the smoke was not observed to change significantly due to gas cooling.

A SINFONI view of the nuclear activity and circumnuclear star formation in NGC 4303 – II. Spatially resolved stellar populations

We present a spatially resolved stellar population study of the inner $\sim$200\,pc radius of NGC4303 based on near-infrared integral field spectroscopy with SINFONI/VLT at a spatial resolution of 40-80pc and using the STARLIGHT code. We found the distribution of the stellar populations presents a spatial variation, suggesting an age stratification. Three main structures stand out. Two nuclear blobs, one composed by young stars (t $\leq$ 50Myr) and one with intermediate-age stars (50Myr $<$ t $\leq$ 2Gyr) both shifted from the centre. The third one is an internal intermediate-age spiral arm-like structure, surrounding the blob of young stars. Our results indicate star formation has occurred through multiple bursts in this source. Furthermore, the youngest stellar populations (t $\lesssim$ 2Gyr) are distributed along a circumnuclear star-forming ring with r$\sim$250pc. The ring displays star formation rates (SFRs) in the range of 0.002-0.14M$_{\odot}$yr$^{-1}$, favoring the `pearls-on-a-string' scenario. The old underlying bulge stellar population component (t $>$ 2Gyr) is distributed outside the two blob structures. For the nuclear region (inner $\sim$60pc radius) we derived a SFR of 0.43\,M$_{\odot}$yr$^{-1}$ and found no signatures of non-thermal featureless continuum and hot dust emission, supporting the scenario in which a LLAGN/LINER-like source is hidden in the centre of NGC4303. Thus, our results reveal a rather complex star formation history in NGC4303, with different stellar population components coexisting with a low efficiency accreting black hole in its centre.

Silent T2* and T2 encoding using ZTE combined with BURST.

To obtain T2* and T2 -weighted images as well as quantitative T2* , T2 , and susceptibility maps with a novel, silent 3D imaging method, which combines zero-echo-time (ZTE) imaging with gradient- and spin-echo BURST encoding. After a segment of standard ZTE encoding with multiple 3D radial k-space spokes, the direction of traversing k-space is reversed while excitation is switched off. This recalls gradient echoes for each spoke/excitation. This results in multiple images: one FID image from ZTE and multiple BURST echo images at different echo times weighted by a T2* decay. By adding a pair of 180° pulses with an appropriate wait period, it is also possible to obtain spin echoes, leading to T2 -weighted images. Data is reconstructed using standard 3D gridding and Fourier transformation. In vivo feasibility was demonstrated by imaging the brain of multiple healthy volunteers. It is possible to acquire high-quality T2* - and T2 -weighted brain images in a silent manner. From images acquired with gradient-echo ZTE-BURST, it is possible to extract quantitative T2* and magnetic susceptibility maps, whereas the spin echo version yields T2 maps. ZTE combined with BURST enables silent acquisition of T2* - and T2 -weighted images with good image quality.

SOCIOEMOTIONAL DYNAMICS OF EMOTION REGULATION AND DEPRESSIVE SYMPTOMS: A PERSON-SPECIFIC NETWORK APPROACH

Socioemotional processes engaged in daily life may afford and/or constrain individuals' emotion regulation in ways that affect psychological health. Recent findings from experience sampling studies suggest that persistence of negative emotions (emotion inertia), the strength of relations among an individual's negative emotions (density of the emotion network), and cycles of negative/aggressive interpersonal transactions are related to psychological health. Using multiple bursts of intensive experience sampling data obtained from 150 persons over one year, person-specific analysis, and impulse response analysis, this study quantifies the complex and interconnected socioemotional processes that surround individuals' daily social interactions and on-going regulation of negative emotion in terms of recovery time. We also examine how this measure of regulatory inefficiency is related to interindividual differences and intraindividual change in level of depressive symptoms. Individuals with longer recovery times had higher overall level of depressive symptoms. As well, during periods where recovery time of sadness was longer than usual, individuals' depressive symptoms were also higher than usual, particularly among individuals who experienced higher overall level of stressful life events. The findings and analysis highlight the utility of a person-specific network approach to study emotion regulation, how regulatory processes change over time, and potentially how planned changes in the configuration of individuals' systems may contribute to psychological health.

Fast radio burst source properties from polarization measurements

Recent polarization measurements of fast radio bursts (FRBs) provide new insights on these enigmatic sources. We show that the nearly 100% linear polarization and small variation of the polarization position angles (PAs) of multiple bursts from the same source suggest that the radiation is produced near the surface of a strongly magnetized neutron star. As the emitted radiation travels through the magnetosphere, the electric vector of the X-mode wave adiabatically rotates and stays perpendicular to the local magnetic field direction. The PA freezes at a radius where the plasma density becomes too small to be able to turn the electric vector. At the freeze-out radius, the electric field is perpendicular to the magnetic dipole moment of the neutron star projected in the plane of the sky, independent of the radiation mechanism or the orientation of the magnetic field in the emission region. We discuss a number of predictions of the model. The variation of PAs from repeating FRBs should follow the rotational period of the underlying neutron star (but the burst occurrence may not be periodic). Measuring this period will provide crucial support for the neutron star nature of the progenitors of FRBs. For FRB 121102, the small range of PA variation means that the magnetic inclination angle is less than about 20 degrees and that the observer's line of sight is outside the magnetic inclination cone. Other repeating FRBs may have a different range of PA variation from that of FRB 121102, depending on the magnetic inclination and the observer's viewing angle.

El Dr. Hyacinthe Guilleminot y los primeros sistemas de sincronización respiratoria y cardíaca para obtención de imagen radiológica

In an era when it was not possible to achieve quality x-rays with short exposure times, the need to obtain chest images without movement led the French doctor Emré Hyacinthe Guilleminot to construct a machine that repeatedly emitted x-rays only when desired during the respiratory cycle. His aim was to create a satisfactory radiograph from multiple short bursts performed at the moment of inhalation or exhalation, based on Charles Bouchard's research on heart disease. He extended his idea to radiography of the heart, creating a system that enabled images to be obtained disassociating the phases of heartbeat. This article seeks to explain the basic functioning of these mechanisms, and to recover previous research papers that led to their creation. We will also retrieve biographical and personal data of the two people involved – one directly, the other indirectly – in these novel inventions.

Prefrontal cortex modulates firing pattern in the nucleus reuniens of the midline thalamus via distinct corticothalamic pathways.

The thalamus has long been recognized for its role in relaying sensory information from the periphery, a function accomplished by its "first-order" nuclei. However, a second category of thalamic nuclei, termed "higher-order" nuclei, have been shown instead to mediate communication between cortical areas. The nucleus reuniens of the midline thalamus (RE) is a higher-order nucleus known to act as a conduit of reciprocal communication between the medial prefrontal cortex (mPFC) and hippocampus. While anatomical and behavioural studies of RE are numerous, circuit-based electrophysiological studies, particularly those examining the impact of cortical input and the thalamic reticular nucleus (TRN) on RE neuron firing, are sparse. To characterize RE neuron firing properties and dissect the circuit dynamics of the infralimbic subdivision of the mPFC (ilPFC), the TRN and RE, we used in vivo, extracellular, single-unit recordings in male Sprague Dawley rats and manipulated neural activity using targeted pharmacological manipulations, electrical stimulation and a projection-specific implementation of designer receptors exclusively activated by designer drugs (DREADDs). We show that ilPFC inhibition reduces multiple burst firing parameters in RE, whereas ilPFC stimulation drives burst firing and dampens tonic firing. In addition, TRN inhibition reduces the number of spontaneously active neurons in RE. Finally, inhibition of ilPFC terminals in RE selectively enhances a subset of burst firing parameters. These findings demonstrate that ilPFC input, both via direct projections and via the TRN, can modulate RE neuron firing pattern in nuanced and complex ways. They also highlight the ilPFC-TRN-RE circuit as a likely critical component of prefrontal-hippocampal interactions.

Progenitor Mass Distribution for Core-collapse Supernova Remnants in M31 and M33

Abstract Using the star formation histories (SFHs) near 94 supernova remnants (SNRs), we infer the progenitor mass distribution for core-collapse supernovae. We use Bayesian inference and model each SFH with multiple bursts of star formation (SF), one of which is assumed to be associated with the SNR. Assuming single-star evolution, the minimum mass of CCSNe is 7.33 − 0.16 + 0.02 M ⊙ , the slope of the progenitor mass distribution is α = − 2.96 − 0.25 + 0.45 , and the maximum mass is greater than M max &gt; 59 M ⊙ with a 68% confidence. While these results are consistent with previous inferences, they also provide tighter constraints. The progenitor distribution is somewhat steeper than a Salpeter initial mass function (α = −2.35). This suggests that either SNR catalogs are biased against the youngest SF regions, or the most massive stars do not explode as easily as lower mass stars. If SNR catalogs are biased, it will most likely affect the slope but not the minimum mass. The uncertainties are dominated by three primary sources of uncertainty, the SFH resolution, the number of SF bursts, and the uncertainty on SF rate in each age bin. We address the first two of these uncertainties, with an emphasis on multiple bursts. The third will be addressed in future work.

The Role of Capillary Hysteresis and Pore‐Scale Heterogeneity in Limiting the Migration of Buoyant Immiscible Fluids in Porous Media

AbstractUnderstanding the main mechanisms affecting long‐term migration and redistribution of injected CO2 in geological carbon storage is needed for developing predictive models to assess environmental risks and designing monitoring schemes. Preparation of a postinjection site care plan is required for CO2 injection wells, including monitoring of pressure changes and injected CO2 plume. Knowledge gaps exist regarding assessment of postinjection monitoring timeframes for the CO2 plume because the processes driving long‐term CO2 plume migration and trapping are not fully understood. In the postinjection stage of geological carbon storage, redistribution of CO2 occurs mainly due to buoyancy and capillary forces. This work presents experimental and modeling studies to investigate processes contributing to postinjection plume distribution and stabilization. We conducted a flow cell experiments (0.5 m × 0.05 m × 0.01 m) with two immiscible fluid phases in a glass bead porous medium to study postinjection plume behavior. We employed a hysteretic macroscopic two‐phase flow model to interpret the experimental results and to understand main processes leading to plume stabilization. Our findings show that capillary pressure hysteresis explains the experimentally observed plume shape and redistribution at early postinjection stages; however, the long‐term plume migration and eventual plume stabilization can only be represented when in addition microscale heterogeneity is accounted for. Results also show that plume stabilization can be extremely slow and that the migration of the plume front can occur through multiple intermittent bursts over long times. Further studies are needed to understand implications of the results for more realistic porous media and large‐scale storage reservoirs.

Stimulated Axion Decay in Superradiant Clouds around Primordial Black Holes.

The superradiant instability can lead to the generation of extremely dense axion clouds around rotating black holes. We show that, despite the long lifetime of the QCD axion with respect to spontaneous decay into photon pairs, stimulated decay becomes significant above a minimum axion density and leads to extremely bright lasers. The lasing threshold can be attained for axion masses μ≳10^{-8} eV, which implies superradiant instabilities around spinning primordial black holes with mass ≲0.01 M_{⊙}. Although the latter are expected to be nonrotating at formation, a population of spinning black holes may result from subsequent mergers. We further show that lasing can be quenched by Schwinger pair production, which produces a critical electron-positron plasma within the axion cloud. Lasing can nevertheless restart once annihilation lowers the plasma density sufficiently, resulting in multiple laser bursts that repeat until the black hole spins down sufficiently to quench the superradiant instability. In particular, axions with a mass ∼10^{-5} eV and primordial black holes with mass ∼10^{24} kg, which may account for all the dark matter in the Universe, lead to millisecond bursts in the GHz radio-frequency range, with peak luminosities ∼10^{42} erg/s, suggesting a possible link to the observed fast radio bursts.

Finite-Length Analysis of Spatially-Coupled Regular LDPC Ensembles on Burst-Erasure Channels

Regular spatially-coupled low-density parity-check ensembles have gained significant interest, since they were shown to universally achieve the capacity of binary memoryless channels under low-complexity belief-propagation decoding. In this paper, we focus primarily on the performance of these ensembles over binary channels affected by bursts of erasures. We first develop an analysis of the finite length performance for a single burst per code word and no errors otherwise. We first assume that the burst erases a complete spatial position, modeling for instance node failures in distributed storage. We provide new tight lower bounds for the block erasure probability (PB) at finite block length and bounds on the coupling parameter for being asymptotically able to recover the burst. We further show that expurgating the ensemble can improve the block erasure probability by several orders of magnitude. Later we extend our methodology to more general channel models. In a first extension, we consider bursts that can start at a random location in the code word and span across multiple spatial positions. Besides the finite length analysis, we determine by means of density evolution the maximum correctable burst length. In a second extension, we consider the case where in addition to a single burst, random bit erasures may occur. Finally, we consider a block erasure channel model which erases each spatial position independently with some probability p, potentially introducing multiple bursts simultaneously. All results are verified using Monte-Carlo simulations.

Joint algorithm for burst detection and AGC improvement in high throughput software defined radio waveform

The SDR networking waveforms mostly use non-constant envelope modulation schemes at the physical layer requiring a stable AGC operation during envelope amplitude variations. Moreover, the size of network packets may vary form a single burst to multiple bursts requiring an AGC with fast convergence to reduce settling time overhead. In this paper, we propose a novel joint algorithm for both the burst detection and improvement of the convergence time and stability of a conventional AGC by using Zadoff-Chu sequence. A specifically designed repeated Zadoff-Chu sequence is used for the detection of burst and fixing the gain for the complete burst duration. The proposed algorithm is implemented on Field Programmable Gate Array (FPGA) on SDR platform. Results of both the simulation and implementation are shown to demonstrate the effectiveness of the proposed technique.

The search for multiple populations in Magellanic Cloud clusters -- IV. Coeval multiple stellar populations in the young star cluster NGC 1978

We have recently shown that the $\sim2$ Gyr old Large Magellanic Cloud star cluster NGC 1978 hosts multiple populations in terms of star-to-star abundance variations in [N/Fe]. These can be seen as a splitting or spread in the sub-giant and red giant branches (SGB and RGB) when certain photometric filter combinations are used. Due to its relative youth, NGC 1978 can be used to place stringent limits on whether multiple bursts of star-formation have taken place within the cluster, as predicted by some models for the origin of multiple populations. We carry out two distinct analyses to test whether multiple star-formation epochs have occurred within NGC 1978. First, we use UV CMDs to select stars from the first and second population along the SGB, and then compare their positions in optical CMDs, where the morphology is dominantly controlled by age as opposed to multiple population effects. We find that the two populations are indistinguishable, with age differences of $1\pm20$ Myr between them. This is in tension with predictions from the AGB scenario for the origin of multiple populations. Second, we estimate the broadness of the main sequence turnoff (MSTO) of NGC 1978 and we report that it is consistent with the observational errors. We find an upper limit of $\sim$65 Myr on the age spread in the MSTO of NGC 1978. This finding is in conflict with the age spread scenario as origin of the extended MSTO in intermediate age clusters, while it fully supports predictions from the stellar rotation model.

Multiple abdominal burst patterns observed during tracheobronchial coughing in anesthetized cats

The cough motor pattern is classically defined as a neuromechanical sequence of inspiration, compression, and expulsion. This definition is most applicable to single coughs. However, humans routinely produce multiple expulsions per each inspiratory effort during single or repetitive coughing. The functional significance of this coughing pattern is not fully understood, but it could represent a mechanism to facilitate the stairstep movement of particulates and mucus up the airway tree against gravity in humans. This repetitive expulsion pattern following single inspiratory cough efforts has not been reported in animal models of coughing. In the anesthetized cat, repetitive coughing can be produced by either mechanical or chemical stimulation of airway afferents. We hypothesized that expulsive cough motor patterns consistent with those seen in humans could be observed in the anesthetized cat. Further, we have previously observed that thoracotomy depresses cough excitability, presumably though a decrease in pulmonary volume‐related feedback. We also hypothesized that thoracotomy would reduce the occurrence of coughs in which multiple expiratory bursts were observed. We investigated the cough patterns of 9 cats pre‐ (n=5) and post‐thoracotomy (n=4) for multiple abdominal bursting patterns during cough. Thoracotomized animals were artificially ventilated at a positive end expiratory pressure of 5 cmH2O. Electromyograms (EMGs) were recorded from the diaphragm, thyroarytenoid, and internal oblique muscles. Repetitive coughing was produced by mechanical stimulation of the intrathoracic airway. The percentage of cough epochs that contained at least one cough with a multiple bursting pattern was similar for closed (CC, 44±18%) and open chested (OC, 42±11%) animals. These patterns consisted of double abdominal bursts (71%), three abdominal bursts (23%) and four bursts (5%). Corresponding abdominal bursts had similar amplitudes in both CC and OC animals. In OC animals, the amplitude of the second abdominal burst (CC − 45±11 to 31±7%, p=n.s.; OC − 43±4 to 28±5, p&lt;0.05) was significantly lower than the first. Thoracotomy prolonged E2 duration for coughs with only 1 expiratory burst (CC 1±0.2s; OC 2±0.4 s, p &lt; 0.05), but not for multiple expiratory bursts (CC 0.6±0.1 s; OC 0.9±0.4 s). The time between multiple abdominal bursts (CC 232±16 msec; OC 233±32 msec) was not different after thoracotomy. In some animals, small amplitude bursts in thyroarytenoid EMGs occurred out of phase with multiple abdominal bursting, consistent with adductor/abdominal oscillations. We conclude that the anesthetized cat is capable of expressing multiple abdominal bursting following a single inspiratory effort during tracheobronchial coughing. Our results support the existence of multiple oscillatory patterns during repetitive tracheobronchial coughing in the cat. This pattern may be analogous to that exhibited by awake humans.Support or Funding InformationSupported by NIH HL 103415 and 1OT20D001983.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

High-molecular-weight adiponectin is inversely associated with sympathetic activity in polycystic ovary syndrome

To examine the role of high-molecular-weight (HMW) adiponectin and its relationship to sympathetic activity in women with polycystic ovary syndrome (PCOS). Cross sectional study using biobanked samples. Not applicable. Premenopausal women with PCOS (n = 46, Rotterdam diagnostic criteria) and without PCOS (n = 22). None. High-molecular-weight adiponectin levels with secondary outcomes of sympathetic activity and leptin levels. The high-molecular-weight adiponectin level was lower in women with PCOS (median 2.2 [interquartile range (IQR)2.3] μg/mL) than in controls (median 3 [IQR2.5] μg/mL) (age and BMI adjusted), and it correlated inversely with the values measured for homeostatic model of assessment of insulin resistance (HOMA-IR), fasting insulin, triglycerides, and free androgen index and positively with sex hormone-binding globulin (SHBG) and high-density lipoprotein cholesterol in all participants and in the PCOS group. In the PCOS group, sympathetic activity (burst frequency) was statistically significantly higher than in controls (median 26 [IQR11] vs. median 22 [IQR14], respectively) and correlated inversely with HMW adiponectin (r = -0.230). The leptin levels were similar between the women with PCOS and controls and did not statistically significantly correlate with HMW adiponectin or sympathetic activity. On multiple regression analysis, burst frequency and SHBG explained 40% of the HMW adiponectin variability (B = -0.7; 95% CI -1.2 to -0.2; and B = 0.01; 95% CI 0.004-0.01) in PCOS. Alongside insulin resistance, increased sympathetic activity is associated with and may modulate HMW adiponectin levels in women with PCOS.

Socioemotional Dynamics of Emotion Regulation and Depressive Symptoms: A Person-Specific Network Approach.

Socioemotional processes engaged in daily life may afford and/or constrain individuals' emotion regulation in ways that affect psychological health. Recent findings from experience sampling studies suggest that persistence of negative emotions (emotion inertia), the strength of relations among an individual's negative emotions (density of the emotion network), and cycles of negative/aggressive interpersonal transactions are related to psychological health. Using multiple bursts of intensive experience sampling data obtained from 150 persons over one year, person-specific analysis, and impulse response analysis, this study quantifies the complex and interconnected socioemotional processes that surround individuals' daily social interactions and on-going regulation of negative emotion in terms of recovery time. We also examine how this measure of regulatory inefficiency is related to interindividual differences and intraindividual change in level of depressive symptoms. Individuals with longer recovery times had higher overall level of depressive symptoms. As well, during periods where recovery time of sadness was longer than usual, individuals' depressive symptoms were also higher than usual, particularly among individuals who experienced higher overall level of stressful life events. The findings and analysis highlight the utility of a person-specific network approach to study emotion regulation, how regulatory processes change over time, and potentially how planned changes in the configuration of individuals' systems may contribute to psychological health.

Coal bursts that occur during development: A rock mechanics enigma

Coal bursts are typically associated with highly stressed coal. Most bursts occur during retreat mining (longwall mining or pillar recovery) in highly stressed locations like the tailgate corner of the longwall panel. Others are associated with multiple seam interactions. However, a small but significant percentage of coal bursts have occurred during development or in outby locations unaffected by active mining. Most development bursts have been relatively small, but some have been highly destructive. No theory of coal bursts can be complete if it does not account for this type of event. This paper focusses on the development mining coal burst experience in the US, putting it into the context of the entire US coal burst database. The first documented development coal burst occurred almost exactly 100 years ago during slope drivage at the Sunnyside Mine in Utah. Sunnyside subsequently had a long history of bursts, mainly during retreat mining but also during development. Several Colorado mines have also experienced multiple development bursts. Many, but by no means all, of the development bursts in these western US coalfields have been associated with known faults. In the Central Appalachian coalfields, most development bursts have occurred in multiple seam situations. In some of these cases, however, there was no retreat mining in either seam. The paper closes with some lessons from this history, with implications for preventing such events in the future.

Type I X-ray Bursts Detected by the JEM-X Telescope Onboard the INTEGRAL Observatory in 2003–2015

We present the results of our analysis of the JEM-X/INTEGRAL data obtained from January 2003 to January 2015 aimed at searching for type I X-ray bursts from known and new bursters. Such bursts are caused by thermonuclear explosions on the surface of a neutron star. We have searched for bursts in the records of the count rate of the JEM-X detectors in the 3–20 keV energy band. We have separately reconstructed and analyzed the light curves of 104 X-ray bursters known to date based on the JEM-X data. A similar search for bursts was previously carried out in the 15–25 keV data from the IBIS/ISGRI telescope onboard the INTEGRAL observatory obtained in 2003–2009. We have continued to analyze the data from this telescope up until the observations in January 2015. The joint catalog of bursts detected by the two instruments includes 2201 events; their basic parameters are given. The large size of the sample of bursts makes it one of the most representative of the existing one and allows various statistical studies of bursts to be performed. In particular, we have constructed the dependence of the mean rate of type I bursts from bursters on the luminosity (accretion rate), revealed an appreciable burst rate from sources with a near-Eddington luminosity, and investigated the population of multiple bursts with a recurrence time much shorter than the time it takes for a critical mass of matter required for the initiation of an explosion to be accumulated on the neutron star surface. Almost all of the detected bursts are associated with already known bursters,we have found only one previously unknown burster, IGRJ17380-3749, in the archival data, and one more known, but poorly studied source, AX J1754.2-2754, has been identified as a burster. Several similar sources have previously been identified as bursters directly during the INTEGRAL observations.