Impulsive Source of the 2017 MW=7.3 Ezgeleh, Iran, Earthquake.

On 12 November 2017, a M W=7.3 earthquake struck near the Iranian town of Ezgeleh, at the Iran-Iraq border. This event was located within the Zagros fold and thrust belt which delimits the continental collision between the Arabian and Eurasian Plates. Despite a high seismic risk, the seismogenic behavior of the complex network of active faults is not well documented in this area due to the long recurrence interval of large earthquakes. In this study, we jointly invert interferometric synthetic aperture radar and near-field strong motions to infer a kinematic slip model of the rupture. The incorporation of these near-field observations enables a fine resolution of the kinematic rupture process. It reveals an impulsive seismic source with a strong southward rupture directivity, consistent with significant damage south of the epicenter. We also show that the slip direction does not match plate convergence, implying that some of the accumulated strain must be partitioned onto other faults.

Resolving Fine-Scale Heterogeneity of Co-seismic Slip and the Relation to Fault Structure.

Fault slip distributions provide important insight into the earthquake process. We analyze high-resolution along-strike co-seismic slip profiles of the 1992 Mw = 7.3 Landers and 1999 Mw = 7.1 Hector Mine earthquakes, finding a spatial correlation between fluctuations of the slip distribution and geometrical fault structure. Using a spectral analysis, we demonstrate that the observed variation of co-seismic slip is neither random nor artificial, but self-affine fractal and rougher for Landers. We show that the wavelength and amplitude of slip variability correlates to the spatial distribution of fault geometrical complexity, explaining why Hector Mine has a smoother slip distribution as it occurred on a geometrically simpler fault system. We propose as a physical explanation that fault complexity induces a heterogeneous stress state that in turn controls co-seismic slip. Our observations detail the fundamental relationship between fault structure and earthquake rupture behavior, allowing for modeling of realistic slip profiles for use in seismic hazard assessment and paleoseismology studies.

Diameter dependent thermoelectric properties of individual SnTe nanowires.

The lead-free compound tin telluride (SnTe) has recently been suggested to be a promising thermoelectric material. In this work, we report on the first thermoelectric study of individual single-crystalline SnTe nanowires with different diameters ranging from ∼218 to ∼913 nm. Measurements of thermopower S, electrical conductivity σ and thermal conductivity κ were carried out on the same nanowires over a temperature range of 25-300 K. While the electrical conductivity does not show a strong diameter dependence, the thermopower increases by a factor of two when the nanowire diameter is decreased from ∼913 nm to ∼218 nm. The thermal conductivity of the measured NWs is lower than that of the bulk SnTe, which may arise from the enhanced phonon - surface boundary scattering and phonon-defect scattering. Temperature dependent figure of merit ZT was determined for individual nanowires and the achieved maximum value at room temperature is about three times higher than that in bulk samples of comparable carrier density.

Note: Time-gated 3D single quantum dot tracking with simultaneous spinning disk imaging.

We describe recent upgrades to a 3D tracking microscope to include simultaneous Nipkow spinning disk imaging and time-gated single-particle tracking (SPT). Simultaneous 3D molecular tracking and spinning disk imaging enable the visualization of cellular structures and proteins around a given fluorescently labeled target molecule. The addition of photon time-gating to the SPT hardware improves signal to noise by discriminating against Raman scattering and short-lived fluorescence. In contrast to camera-based SPT, single-photon arrival times are recorded, enabling time-resolved spectroscopy (e.g., measurement of fluorescence lifetimes and photon correlations) to be performed during single molecule/particle tracking experiments.

Near-unity quantum yields of biexciton emission from CdSe/CdS nanocrystals measured using single-particle spectroscopy.

Biexciton photoluminescence (PL) quantum yields (Q(2X)) of individual CdSe/CdS core-shell nanocrystal quantum dots with various shell thicknesses are derived from independent PL saturation and two-photon correlation measurements. We observe a near-unity Q(2X) for some nanocrystals with an ultrathick 19-monolayer shell. High Q(2X)'s are, however, not universal and vary widely among nominally identical nanocrystals indicating a significant dependence of Q(2X) upon subtle structural differences. Interestingly, our measurements indicate that high Q(2X)'s are not required to achieve complete suppression of PL intensity fluctuations in individual nanocrystals.

Nano-engineered electron-hole exchange interaction controls exciton dynamics in core-shell semiconductor nanocrystals.

A strong electron-hole exchange interaction (EI) in semiconductor nanocrystals (NCs) gives rise to a large (up to tens of meV) splitting between optically active ('bright') and optically passive ('dark') excitons. This dark-bright splitting has a significant effect on the optical properties of band-edge excitons and leads to a pronounced temperature and magnetic field dependence of radiative decay. Here we demonstrate a nanoengineering-based approach that provides control over EI while maintaining nearly constant emission energy. We show that the dark-bright splitting can be widely tuned by controlling the electron-hole spatial overlap in core-shell CdSe/CdS NCs with a variable shell width. In thick-shell samples, the EI energy reduces to <250 µeV, which yields a material that emits with a nearly constant rate over temperatures from 1.5 to 300 K and magnetic fields up to 7 T. The EI-manipulation strategies demonstrated here are general and can be applied to other nanostructures with variable electron-hole overlap.

Highly emissive multiexcitons in steady-state photoluminescence of individual "giant" CdSe/CdS Core/Shell nanocrystals.

The development of nanocrystal quantum dots (NQDs) with suppressed nonradiative Auger recombination has been an important goal in colloidal nanostructure research motivated by the needs of prospective applications in lasing devices, light-emitting diodes, and photovoltaic cells. Here, we conduct single-nanocrystal spectroscopic studies of recently developed core-shell NQDs (so-called "giant" NQDs) that comprise a small CdSe core surrounded by a 16-monolayer-thick CdS shell. Using both continuous-wave and pulsed excitation, we observe strong emission features due both to neutral and charged biexcitons, as well as multiexcitons of higher order. The development of pronounced multiexcitonic peaks in steady-state photoluminescence of individual nanocrystals, as well as continuous growth of the emission intensity in the range of high pump levels, point toward a significant suppression of nonradiative Auger decay that normally renders multiexcitons nonemissive. The unusually high multiexciton emission efficiencies in these systems open interesting opportunities for studies of multiexciton phenomena using well-established methods of single-dot spectroscopy, as well as new exciting prospects for applications, that have previously been hampered by nonradiative Auger decay.

Clinical diagnosis of acute coronary syndrome in patients with chest pain and a normal or non-diagnostic electrocardiogram.

BACKGROUND: Clinical features may be used to determine which patients with suspected acute coronary syndrome (ACS), but a normal or non-diagnostic ECG, should be selected for further investigation or inpatient care. We aimed to measure the diagnostic value of clinical features for ACS. METHODS: Standardised data relating to presenting characteristics, associated features and risk factors were collected at seven chest pain units established for the ESCAPE trial. All patients received troponin measurement at least 6 h after last significant symptoms, creatine kinase MB(mass) gradient over 2 h and, if appropriate, treadmill exercise testing. The reference standard of ACS was defined as troponin >0.03 ng/ml, creatine kinase MB(mass) gradient >3.0 ng/ml or early positive treadmill exercise test. RESULTS: 1576 patients were analysed, including 132 (8.4%) with ACS. Patients with ACS were older, had longer symptom duration, were more likely to be a man, hypertensive and an ex-smoker or have pain radiating to their right arm. On multivariate analysis, only age, duration, sex and radiation of pain to the right arm were independently associated with ACS. Likelihood ratios (95% CI) were radiation of pain to the right arm, 2.9 (95% CI 1.4 to 6.3), male sex 1.2 (95% CI 1.0 to 1.3) and female sex 0.79 (95% CI 0.62 to 1.0). The area under the receiver operator characteristic curve for age was 0.629 (95% CI 0.573 to 0.686) and for duration was 0.546 (95% CI 0.481 to 0.610). CONCLUSION: Clinical features have very limited value for diagnosing ACS in patients with a normal or non-diagnostic ECG. Radiation of pain to the right arm increases the likelihood of ACS.

Bakery flour dust exposure causes non-allergic inflammation and enhances allergic airway inflammation in mice.

BACKGROUND: Baker's asthma is one of the most commonly reported occupational lung diseases in countries where fresh bread is baked daily in large quantities, and is characterized by rhinitis, bronchial hyperresponsiveness, and reversible airflow obstruction. Epidemiological studies have identified pre-existing atopy as an important risk factor for developing baker's asthma, yet the aetiology and pathogenesis of baker's asthma remain poorly understood. OBJECTIVE: We sought to develop a mouse model of baker's asthma that could be used to characterize the development and progression of baker's asthma. METHODS: We were unable to sensitize mice to bakery flour dust or flour dust extract. We assessed total inflammatory cells, cellular differential, total serum IgE and the pro-inflammatory cytokine response to oropharyngeally instilled bakery flour dust or flour dust extract by itself or in the context of ovalbumin (OVA) sensitization and challenge. RESULTS: Both bakery flour dust and flour dust extract consistently elicited a neutrophilic inflammation in a Toll-like receptor 4-independent manner; suggesting that endotoxin is not playing a role in the inflammatory response to flour dust. Moreover, bakery flour dust and dust extract significantly enhance the inflammatory response in OVA-sensitized and challenged mice. CONCLUSIONS: Bakery flour dust and flour dust extract are strongly pro-inflammatory and can cause non-allergic airway inflammation and can enhance allergen-mediated airway inflammation.

Successful treatment of Ochroconis gallopavum infection in an immunocompetent host.

Ochroconis gallopavum, a dematiaceous fungus, is a rare cause disease in immunocompromised patients and epidemic encephalitis in poultry. We report the first case of active O. gallopavum pulmonary infection in an immunocompetent host with rapid and complete response to oral antifungal therapy.

The Food Marketing Institute and the National Council of Chain Restaurants: animal welfare and the retail food industry in the United States of America.

In order to achieve real change, there must be a motivating force and all the stakeholders need to be involved. This is the premise of the animal welfare programme developed for the food retail, wholesale and chain restaurant industries in the United States of America (USA) by the Food Marketing Institute (FMI) and the National Council of Chain Restaurants (NCCR). This paper outlines a collaborative process that retailers and producers in the USA are using to enhance the care and welfare of animals in commercial food production. Although the efforts of the FMI and the NCCR are still underway, the process provides one example of how different parts of the food production system can work together to achieve positive change.

Incidences of problematic organisms on petrifilm aerobic count plates used to enumerate selected meat and dairy products.

Petrifilm aerobic count plates are similar to or better than conventional pour plates. Petrifilm has its problems, however; some microorganisms can liquefy the Petrifilm gel and others do not produce the necessary color change with the indicator dye used. Petrifilm aerobic count plates were compared with the pour plates for determining the incidence and identification of problematic organisms in 329 meat and dairy products. Petrifilm plates produced higher mean counts with better repeatability than did pour plates. There was also close correlation between methods with coefficients of 0.97 to 1.0. Bacillus subtilis, Bacillus licheniformis, and a group D Streptococcus liquefied Petrifilm gels in 17.4% of the samples tested: dairy products accounted for 16.0%, and meats accounted for the remaining 1.4%. Liquefaction hindered enumeration in 3.2% of the Petrifilm plates used. Streptococcus viridans was not detectable on Petrifilm plates after the recommend incubation period, and this organism occurred in 0.3% of the Petrifilm plates used. These results indicate that Petrifilm plates would be unsuitable for samples with large numbers of these organisms. Knowledge of the contaminating flora may be an asset when utilizing Petrifilm aerobic count plates for the enumeration of microbes in food.

Effect of zero- to one-dimensional transformation on multiparticle Auger recombination in semiconductor quantum rods.

We study the effect of the zero- to one-dimensional (1D) transformation on multiparticle Auger recombination using a series of elongated semiconductor nanocrystals (quantum rods). We observe a transition from the three- to two-particle recombination process as the nanocrystal aspect ratio is increased. This transition indicates that in the 1D confinement limit, Auger decay is dominated by Coulomb interactions between 1D excitons that recombine in a bimolecular fashion. One consequence of this effect is strongly reduced decay rates of higher multiparticle states that lead to increased optical-gain lifetimes and efficient light amplification due to involvement of excited electronic states.

Confocal microscopy of Thygeson's superficial punctate keratopathy.

PURPOSE: To describe the changes seen with the confocal microscope in Thygeson's superficial punctate keratopathy (TSPK). METHODS: Confocal microscopy was performed on six patients with TSPK presenting to Manchester Royal Eye Hospital from October 1999 to June 2001. Both eyes were examined including the normal fellow eyes of two patients with unilateral TSPK. Images were compared with age-matched controls. RESULTS: Irregular nerve fibers, masked by considerable haze, were seen in the subepithelial nerve plexus immediately above Bowman's membrane in TSPK. Generalized haze was also present in the anterior stroma along with areas of high reflectivity, microdots, and reflective bodies. Keratocytes had highly reflective nuclei and cell bodies of irregular size, orientation, and shape. The changes were related to the duration of TSPK, were not seen in normal fellow eyes, and were also present in areas without lesions. CONCLUSION: Confocal imaging of TSPK demonstrated considerable abnormalities in the subepithelial nerve plexus, Bowman's membrane, and the anterior stroma that were related to disease duration. Similar changes have been reported in a variety of corneal diseases and following laser corneal surgery. Recent evidence has supported interactions between the epithelium and Bowman's membrane and the anterior stroma in corneal disease and after laser corneal surgery. We speculate that such interactions may have a role in TSPK.

Spectrally resolved dynamics of energy transfer in quantum-dot assemblies: towards engineered energy flows in artificial materials.

We report on the dynamics of resonant energy transfer in monodisperse, mixed-size, and energy-gradient (layered) assemblies of CdSe nanocrystal quantum dots. Time-resolved and spectrally resolved photoluminescence directly reveals the energy-dependent transfer rate of excitons from smaller to larger dots via electrostatic coupling. The data show a rapid (0.7-1.9 ns) energy transfer directly across a large tens-of-meV energy gap (i.e., between dots of disparate size), and suggest that interdot energy transfer can approach picosecond time scales in structurally optimized systems.