Earthquake-induced rotational ground motions from G-Pisa ring laser gyroscope.

In order to fully characterize the local ground motion induced by earthquakes, one needs to determine three components of translation, six components of strain and three components of rotation (Aki and Richards, 2002). The first two quantities are commonly studied by seismologists with the use of classical seismological instrumentation, like accelerometers/seismometers and strainmeters. Rotational motions in seismology have always been considered negligible, mainly because of the lack of instrumentation of adequate sensitivity. Indeed, the rotation rates which have been observed thus far, range from 10^-1 rad/s close to seismic sources (Nigbor, 1994), to 10^-11 rad/s for large telesismic earthquakes (Igel et al.2005, 2007). It is expected that collocated measurements of translations and rotations may (1) allow the estimate of velocities and propagation directions of the incoming wavefield (2) help to further constrain rupture processes and (3) provide additional hazard-relevant information to earthquake engineers (Igel et al.2007). But as reported just a decade ago by Aki and Richards (2002): “...seismology still awaits a suitable instrument for making such measurements.” Over the last few years ring laser gyroscopes, based on the Sagnac effect, demonstrated a high potential in investigating the rotational ground motion, and they appear to be the most promising instruments to address Aki and Richard's requirements. Theory suggests a general link between rotational and translational motions induced by earthquakes. In the case of horizontally and vertically polarized surface waves (Love and Rayleigh-waves) the relations are particularly simple. Vertical acceleration and rotation rate about a horizontal axis should be in phase and scaled by a factor that corresponds to local Rayleigh-waves phase velocity. By the same token, transverse acceleration and rotation rate about vertical axis should be in phase and scaled by two times Love-waves phase velocity. According to the above relationships, under the plane-wave approximation, collocated measurements of translation and rotation can provide the estimate of phase velocities and propagation directions, otherwise only accessible through seismic array measurements, polarization analysis, or additional strain measurements. This thesis focuses on the data collected by the G-Pisa ring laser gyroscope, developed by the University of Pisa (Department of Physics) and INFN. This instrument has been operating for almost 2 years at the European Gravitational Observatory in Cascina (Pisa), in the framework of the VIRGO project. In particular, I report the very first seismic analysis of the rotational data from a gyrolaser lying in the vertical plane, which is sensitive to rotation about a horizontal axis (tilt). The main part of the thesis is dedicated to the analysis of the Mw=9.0, March 11th, 2011, Japan earthquake; in addition, I also account for recordings from some events occurred at regional distances. The first objective of this work is to characterize the performance of G-Pisa in relation to a collocated accelerometer and to verify the ground-coupling of the instrument. By calculating power spectral density (PSD) of rotation rate and acceleration I first identify the signal to noise ratio as a function of frequency and, by computing time-frequency transforms (spectrograms), I individuate the most energetic frequency bands as a function of time for both the instruments during several selected earthquakes. Then, rotation rates and accelerations are correlated within subsequent frequency bands, in order to quantify similarity between the signals. The second objective of the thesis is to compare the recorded rotation rates with those obtained through an array-based analysis. Applying the seismo-geodetic method by Spudich et al. (2008), I derive the rotation rate from a tripartite array of three-components accelerometers. This method provides an independent estimation of ground rotations that should be in agreement with that directly recorded by the gyrolaser. Results from this analysis show that the two measurements are in general agreement; I attribute the discrepancies to both the geometrical setting of the array and the band limitations of its sensors. The third objective concerns phase velocities estimation and derivation of surface waves dispersion curves from collocated measurements of rotation and translation. Following Igel et al. (2005, 2007) and Kurrle et al. (2010), I address this issue by calculating the zero-lag correlation coefficient between translational and rotational traces. When the correlation coefficient is above an arbitrary threshold, phase velocity is obtained through a linear regression within overlapping sliding time windows. Iterating the procedure after a narrow band-pass filtering of both traces, it is possible to derive a dispersion curve for the selected wave packet. A theoretically equivalent dispersion curve could be derived in frequency domain as showed by Suryanto et al (2006), both for Love- and Rayleigh-waves, simply by calculating the spectral ratios between translation and rotation. I implemented this second procedure using a multitaper method (MTM, Thomson, 1982), in order to reduce variance and bias by averaging periodograms obtained using a properly-designed taper. The dispersion curves calculated in this manner are compared to those obtained with a multi-frequency Plane Wave Fit (PWF) analysis. This method that consists in estimating wavefield slowness for an array of sensors provides independent information about velocities and direction of propagation (azimuth) for plane waves crossing the array. Rayleigh-waves dispersion curves derived from the Japan earthquake, are then compared against the theoretical phase velocities derived from a standard (AK135) Earth Model. Since Rayleigh-waves are fully recorded by the gyrolaser only when their direction of propagation is perpendicular to G-Pisa area vector, I implemented a rotation rate signal correction method that takes into account the different directions of propagation of Rayleigh-waves (as estimated from PWF inversion) with respect to G-Pisa axis of sensitivity. This correction leads to a more reliable result in estimating phase velocities, that otherwise would be overestimated. Collocated measurements of rotation about vertical axis and transverse acceleration for horizontally-polarized seismic waves (SH- and Love-waves) allow estimating direction of propagation and azimuth of the incoming wavefield. Following Igel et al. (2007), and Hadziioannou et al. (2012), I conducted these estimates for Love waves recorded when G-Pisa was configured with area vector oriented vertically. This thesis is organised into five chapters. In the first chapter, I briefly report the general theory behind rotational motions, and present the relationships between rotation and translation in the context of classical elasticity. Here I show that surface-waves phase velocities and thus dispersion curves can be obtained from collocated measurements or rotation and translation. In the second chapter I present the instrumentation and data, with particular reference to G-Pisa and its ability to investigate both Rayleigh-and Love-waves with a sensitivity in the order of a few nrad/s/over the 0.02-1 Hz frequency band. In the third chapter I describe the data analysis methods, and their practical implementation in terms of Matlab scripts. In the fourth chapter I present and critically comment the results from the analysis. This chapter is divided into two sections, dedicated respectively to the Love- and Rayleigh-waves results. The last chapter is dedicated to the general discussion and conclusions

The deep structure of the Larderello-Travale geothermal field (Italy) from integrated, passive seismic investigations

AbstractWe report the preliminary results from a project (GAPSS-Geothermal Area Passive Seismic Sources), aimed at testing the resolving capabilities of passive exploration methods on a well-known geothermal area, namely the Larderello-Travale Geothermal Field (LTGF). Located in the western part of Tuscany (Italy), LTGF is the most ancient geothermal power field of the world. GAPSS consisted of up to 20 seismic stations deployed over an area of about 50 x 50 Km. During the first 12 months of measurements, we located more than 2000 earthquakes, with a peak rate of up to 40 shocks/day. Preliminary results from analysis of these signals include: (i) analysis of Shear-Wave-Splitting from local earthquake data, from which we determined the areal distribution of the most anisotropic regions; (ii) local-earthquake travel-time tomography for both P- and S-wave velocities; (iii) telesismic receiver function aimed at determining the high-resolution (<0.5km) S-velocity structure over the 0-20km depth range, and seismic anisotropy using the decomposition of the angular harmonics of the RF data-set; (iv) S-wave velocity profiling through inversion of the dispersive characteristics of Rayleigh waves from earthquakes recorded at regional distances. After presenting results from these different analyses, we eventually discuss their potential application to the characterisation and exploration of the investigated area

Symptomatic Isolated Pleural Effusion as an Atypical Presentation of Ovarian Hyperstimulation Syndrome

Ovarian hyperstimulation syndrome (OHSS) presents in ~33% of ovarian stimulation cycles with clinical manifestations varying from mild to severe. Its pathogenesis is unknown. Pleural effusion is reported in ~10% of severe OHSS cases and is usually associated with marked ascites. The isolated finding of pleural effusions without ascites, as the main presenting symptom of OHSS is not frequently reported and its pathogenesis is also unknown. We describe two unusual cases of OHSS where dyspnea secondary to unilateral pleural effusion was the only presenting symptom. By reporting our experience, we would like to heighten physicians' awareness in detecting these cases early, as it is our belief that the incidence of pleural effusion in the absence of most commonly recognized risk factors for OHSS may be underestimated and may significantly compromise the health of the patient if treatment is not initiated in a reasonable amount of time

Cross-Linked Hyaluronan Derivatives in the Delivery of Phycocyanin

An easy and viable crosslinking technology, based on the “click-chemistry” reaction copper(I)-catalyzed azide-alkyne 1,3-dipolar cycloaddition (click-crosslinking), was applied to graft copolymers of medium molecular weight (i.e., 270 kDa) hyaluronic acid (HA) grafted with ferulic acid (FA) residues bearing clickable propargyl groups, as well as caffeic acid derivatives bearing azidoterminated oligo(ethylene glycol) side chains. The obtained crosslinked materials were characterized from the point of view of their structure and aggregation liability to form hydrogels in a water environment. The most promising materials showed interesting loading capability regarding the antioxidant agent phycocyanin (PC). Two novel materials complexes (namely HA(270)-FA-TEGECCL- 20/PC and HA(270)-FA-HEGEC-CL-20/PC) were obtained with a drug-to-material ratio of 1:2 (w/w). Zeta potential measurements of the new complexes (−1.23 mV for HA(270)-FA-TEGECCL- 20/PC and −1.73 mV for HA(270)-FA-HEGEC-CL-20/PC) showed alterations compared to the zeta potential values of the materials on their own, suggesting the achievement of drug–material interactions. According to the in vitro dissolution studies carried out in different conditions, novel drug delivery systems (DDSs) were obtained with a variety of characteristics depending on the desired route of administration and, consequently, on the pH of the surrounding environment, thanks to the complexation of phycocyanin with these two new crosslinked materials. Both complexes showed excellent potential for providing a controlled/prolonged release of the active pharmaceutical ingredient (API). They also increased the amount of drug that reach the target location, enabling pH-dependent release. Importantly, as demonstrated by the DPPH free radical scavenging assay, the complexation process, involving freezing and freeze-drying, showed no adverse effects on the antioxidant activity of phycocyanin. This activity was preserved in the two novel materials and followed a concentration-dependent pattern similar to pure PC

First diagnosis of multisystem inflammatory syndrome in children (MIS-C): an analysis of PoCUS findings in the ED

Children with multisystem inflammatory syndrome (MIS-C) tend to develop a clinical condition of fluid overload due both to contractile cardiac pump deficit and to endotheliitis with subsequent capillary leak syndrome. In this context, the ability of point-of-care ultrasound (PoCUS) to simultaneously explore multiple systems and detect polyserositis could promote adequate therapeutic management of fluid balance. We describe the PoCUS findings in a case-series of MIS-C patients admitted to the Emergency Department. At admission 10/11 patients showed satisfactory clinical condition without signs and symptoms suggestive for cardiovascular impairment/shock, but PoCUS showed pathological findings in 11/11 (100%). In particular, according to Rapid Ultrasound in SHock (RUSH) protocol, cardiac hypokinesis was detected in 5/11 (45%) and inferior vena cava dilatation in 3/11 (27%). Peritoneal fluid was reported in 6/11 cases (54%). Lung ultrasound (LUS) evaluation revealed an interstitial syndrome in 11/11 (100%), mainly localized in posterior basal lung segments. We suggest PoCUS as a useful tool in the first evaluation of children with suspected MIS-C for the initial therapeutic management and the following monitoring of possible cardiovascular deterioration

Streptomyces coelicolor Vesicles: Many Molecules To Be Delivered

Streptomyces coelicolor is a model organism for the study of Streptomyces, a genus of Gram-positive bacteria that undergoes a complex life cycle and produces a broad repertoire of bioactive metabolites and extracellular enzymes. This study investigated the production and characterization of membrane vesicles (MVs) in liquid cultures of S. coelicolor M145 from a structural and biochemical point of view; this was achieved by combining microscopic, physical and -omits analyses. Two main populations of MVs, with different sizes and cargos, were isolated and purified. S. coelicolor MV cargo was determined to be complex, containing different kinds of proteins and metabolites. In particular, a total of 166 proteins involved in cell metabolism/differentiation, molecular processing/transport, and stress response were identified in MVs, the latter functional class also being important for bacterial morpho-physiological differentiation. A subset of these proteins was protected from degradation following treatment of MVs with proteinase K, indicating their localization inside the vesicles. Moreover, S. coelicolor MVs contained an array of metabolites, such as antibiotics, vitamins, amino acids, and components of carbon metabolism. In conclusion, this analysis provides detailed information on S. coelicolor MVs under basal conditions and on their corresponding content, which may be useful in the near future to elucidate vesicle biogenesis and functions.IMPORTANCE Streptomycetes are widely distributed in nature and characterized by a complex life cycle that involves morphological differentiation. They are very relevant in industry because they produce about half of all clinically used antibiotics, as well as other important pharmaceutical products of natural origin. Streptomyces coelicolor is a model organism for the study of bacterial differentiation and bioactive molecule production. S. coelicolor produces extracellular vesicles that carry many molecules, such as proteins and metabolites, including antibiotics. The elucidation of S. coelicolor extracellular vesicle cargo will help us to understand different aspects of streptomycete physiology, such as cell communication during differentiation and response to environmental stimuli. Moreover, the capability of these vesicles for carrying different kinds of biomolecules opens up new biotechnological possibilities related to drug delivery. Indeed, decoding the molecular mechanisms involved in cargo selection may lead to the customization of extracellular vesicle content

Optimal resolution tomography with error tracking and the structure of the crust and upper mantle beneath Ireland and Britain

The classical Backus–Gilbert method seeks localized Earth-structure averages at the shortest length scales possible, given a data set, data errors, and a threshold for acceptable model errors. The resolving length at a point is the width of the local averaging kernel, and the optimal averaging kernel is the narrowest one such that the model error is below a specified level. This approach is well suited for seismic tomography, which maps 3-D Earth structure using large sets of seismic measurements. The continual measurement-error decreases and data-redundancy increases have reduced the impact of random errors on tomographic models. Systematic errors, however, are resistant to data redundancy and their effect on the model is difficult to predict. Here, we develop a method for finding the optimal resolving length at every point, implementing it for surface-wave tomography. As in the Backus–Gilbert method, every solution at a point results from an entire-system inversion, and the model error is reduced by increasing the model-parameter averaging. The key advantage of our method stems from its direct, empirical evaluation of the posterior model error at a point. We first measure inter- station phase velocities at simultaneously recording station pairs and compute phase-velocity maps at densely, logarithmically spaced periods. Numerous versions of the maps with varying smoothness are then computed, ranging from very rough to very smooth. Phase-velocity curves extracted from the maps at every point can be inverted for shear-velocity (V S ) profiles. As we show, errors in these phase-velocity curves increase nearly monotonically with the map roughness. We evaluate the error by isolating the roughness of the phase-velocity curve that cannot be explained by any Earth structure and determine the optimal resolving length at a point such that the error of the local phase-velocity curve is below a threshold. A 3-D V S model is then computed by the inversion of the composite phase-velocity maps with an optimal resolution at every point. The estimated optimal resolution shows smooth lateral variations, confirming the robustness of the procedure. Importantly, the optimal resolving length does not scale with the density of the data coverage: some of the best-sampled locations display relatively low lateral resolution, probably due to systematic errors in the data. We apply the method to image the lithosphere and underlying mantle beneath Ireland and Britain. Our very large data set was created using new data from Ireland Array, the Irish National Seismic Network, the UK Seismograph Network and other deployments. A total of 11 238 inter-station dispersion curves, spanning a very broad total period range (4–500 s), yield unprecedented data coverage of the area and provide fine regional resolution from the crust to the deep asthenosphere. The lateral resolution of the 3-D model is computed explicitly and varies from 39 km in central Ireland to over 800 km at the edges of the area, where the data coverage declines. Our tomography reveals pronounced, previously unknown variations in the lithospheric thickness beneath Ireland and Britain, with implications for their Caledonian assembly and for the mechanisms of the British Tertiary Igneous Province magmatism

Paediatric recurrent pericarditis: Appropriateness of the standard of care and response to IL1-blockade

Objective: To analyse, in a cohort of paediatric patients with recurrent pericarditis (RP) undergoing anti-IL-1 treatment: the agent and dosing used as first line treatment, the long-term efficacy of IL1-blockers, the percentage of patients achieving a drug-free remission, the presence of variables associated with drug-free remission. Study design: Data were collected from patients' charts. Annualized relapse rate (ARR) was used for evaluation of treatment efficacy, bivariate logistic regression analysis for variables associated with drug-free remisison. Results: 58 patients, treated between 2008 and 2018, were included in the study (mean follow-up 2.6 years). 14/56 patients non-responsive to first line drugs were under-dosed. 57 patients were treated with anakinra: the ARR before and during daily treatment was 3.05 and 0.28, respectively (p<0.0001); an increase to 0.83 was observed after the reduction/withdrawal of treatment (p<.0001). The switch from anakinra to canakinumab (5 patients) was associated to an increase of the ARR (0.49 vs 1.46), but without statistical significance (p=0.215). At last follow-up only 9/58 patients had withdrawn all treatments. With the limits of a retrospective study and the heterogeneity between the patients enrolled in the study, a shorter duration of treatment with anakinra was the only variable associated with drug-free remission. Conclusion: This study shows that most of the pediatric patients with RP needing IL-1 blockade received an inadequate treatment with first line agents. The effectiveness of anakinra is supported by this study, but few patients achieved drug free-remission. The different rate of response to anakinra and canakinumab may suggest a possible role of IL1α in the pathogenesis of RP