Potential instability of gas hydrates along the chilean margin due to ocean warming

In the last few years, interest in the offshore Chilean margin has increased rapidly due to the presence of gas hydrates. We have modelled the gas hydrate stability zone off Chilean shores (from 33\ub0 S to 46\ub0 S) using a steady state approach to evaluate the effects of climate change on gas hydrate stability. Present day conditions were modelled using published literature and compared with available measurements. Then, we simulated the effects of climate change on gas hydrate stability in 50 and 100 years on the basis of Intergovernmental Panel on Climate Change and National Aeronautics and Space Administration forecasts. An increase in temperature might cause the dissociation of gas hydrate that could strongly affect gas hydrate stability. Moreover, we found that the high seismicity of this area could have a strong effect on gas hydrate stability. Clearly, the Chilean margin should be considered as a natural laboratory for understanding the relationship between gas hydrate systems and complex natural phenomena, such as climate change, slope stability and earthquakes

Detection of a slow-flow component in contrast-enhanced ultrasound of the synovia for the differential diagnosis of arthritis

Contrast Enhanced Ultrasound (CEUS) is a sensitive imaging technique to assess tissue vascularity, that can be useful in the quantification of different perfusion patterns. This can particularly important in the early detection and differentiation of different types of arthritis. A Gamma-variate can accurately quantify synovial perfusion and it is flexible enough to describe many heterogeneous patterns. However, in some cases the heterogeneity of the kinetics can be such that even the Gamma model does not properly describe the curve, especially in presence of recirculation or of an additional slowflow component. In this work we apply to CEUS data both the Gamma-variate and the single compartment recirculation model (SCR) which takes explicitly into account an additional component of slow flow. The models are solved within a Bayesian framework. We also employed the perfusion estimates obtained with SCR to train a support vector machine classifier to distinguish different types of arthritis. When dividing the patients into two groups (rheumatoid arthritis and polyarticular RA-like psoriatic arthritis vs. other arthritis types), the slow component amplitude was significantly different across groups: mean values of a1 and its variability were statistically higher in RA and RA-like patients (131% increase in mean, p = 0.035 and 73% increase in standard deviation, p = 0.049 respectively). The SVM classifier achieved a balanced accuracy of 89%, with a sensitivity of 100% and a specificity of 78%. © 2017 SPIE

Increase of CSF inflammatory profile in a case of highly active multiple sclerosis

BACKGROUND: Clinical and imaging follow-up coupled with cerebrospinal fluid (CSF) and possibly serum profiling could provide information on disease activity and disability evolution in multiple sclerosis patients. CASE PRESENTATION: We describe the case of a relapsing-remitting MS patient whose history was characterized by failure of several therapeutic approaches and sustained disease activity. By using a highly sensitive immunoassay methodology, we examined protein expression of 70 inflammatory/cytotoxic molecules in two consecutive paired CSF and serum samples, obtained respectively in 2006 and 2013. At disease diagnosis, elevated CSF protein levels of an inflammatory pattern, including CXCL13, CXCL12, IFNγ, TNF, sTNFR1, IL8, sCD163, APRIL, BAFF, pentraxin III and MMP2 were found compared with a group of controls. At the second lumbar puncture, sustained disease activity was accompanied by considerable (more than 2 fold changes) increase expression of most of these inflammatory molecules while no significant changes in serum inflammatory markers were detected in the two consecutive serum samples. CONCLUSIONS: Elevated CSF protein expression of pro-inflammatory mediators, possibly specifically associated to GM demyelination, could remain stable or increase over time in patients with active multiple sclerosis. We underline the role of fluid analysis in understanding the pathophysiology of the disease and providing information on possible markers of disease activity and evolution

A wide field-of-view, modular, high-density diffuse optical tomography system for minimally constrained three-dimensional functional neuroimaging

The ability to produce high-quality images of human brain function in any environment and during unconstrained movement of the subject has long been a goal of neuroimaging research. Diffuse optical tomography, which uses the intensity of back-scattered near-infrared light from multiple source-detector pairs to image changes in haemoglobin concentrations in the brain, is uniquely placed to achieve this goal. Here, we describe a new generation of modular, fibre-less, high-density diffuse optical tomography technology that provides exceptional sensitivity, a large dynamic range, a field-of-view sufficient to cover approximately one-third of the adult scalp, and also incorporates dedicated motion sensing into each module. Using in-vivo measures, we demonstrate a noise-equivalent power of 318 fW, and an effective dynamic range of 142 dB. We describe the application of this system to a novel somatomotor neuroimaging paradigm that involves subjects walking and texting on a smartphone. Our results demonstrate that wearable high-density diffuse optical tomography permits three-dimensional imaging of the human brain function during overt movement of the subject; images of somatomotor cortical activation can be obtained while subjects move in a relatively unconstrained manner, and these images are in good agreement with those obtained while the subjects remain stationary. The scalable nature of the technology we described here paves the way for the routine acquisition of high-quality, three-dimensional, whole-cortex diffuse optical tomography images of cerebral haemodynamics, both inside and outside of the laboratory environment, which has profound implications for neuroscience

Heterogeneity of Cortical Lesion Susceptibility Mapping in Multiple Sclerosis.

BACKGROUND AND PURPOSE: Quantitative susceptibility mapping has been used to characterize iron and myelin content in the deep gray matter of patients with multiple sclerosis. Our aim was to characterize the susceptibility mapping of cortical lesions in patients with MS and compare it with neuropathologic observations. MATERIALS AND METHODS: The pattern of microglial activation was studied in postmortem brain tissues from 16 patients with secondary-progressive MS and 5 age-matched controls. Thirty-six patients with MS underwent 3T MR imaging, including 3D double inversion recovery and 3D-echo-planar SWI. RESULTS: Neuropathologic analysis revealed the presence of an intense band of microglia activation close to the pial membrane in subpial cortical lesions or to the WM border of leukocortical cortical lesions. The quantitative susceptibility mapping analysis revealed 131 cortical lesions classified as hyperintense; 33, as isointense; and 84, as hypointense. Quantitative susceptibility mapping hyperintensity edge found in the proximity of the pial surface or at the white matter/gray matter interface in some of the quantitative susceptibility mapping–hyperintense cortical lesions accurately mirrors the microglia activation observed in the neuropathology analysis. CONCLUSIONS: Cortical lesion susceptibility maps are highly heterogeneous, even at individual levels. Quantitative susceptibility mapping hyperintensity edge found in proximity to the pial surface might be due to the subpial gradient of microglial activation

Blood pressure control is not enough to normalize endothelial repair by progenitor cells

Patients presenting with classical cardiovascular risk factors within acceptable or average value ranges often develop cardiovascular disease, suggesting that other risk factors need to be considered. Considering that endothelial progenitor cells (EPCs) contribute to endothelial repair, we investigated whether EPCs might be such a factor. We compared the ability of peripheral blood EPCs to attach to extracellular matrix proteins and to grow and function in culture, between controlled hypertensive patients exhibiting a Framingham score (FS) of < 10% while showing severe vascular impairment (intima-media thickness/diameter, carotid-femoral pulse wave velocity, brachial artery flow-mediated dilation, carotid and femoral atherosclerotic plaque presence; vulnerable group, N = 30) and those with an FS of ≥ 10% and scarce vascular changes (protected group, N = 30). When compared with vulnerable patients, protected patients had significantly higher early and late-EPC and early and latetunneling nanotube (TNT) numbers. Significant negative associations were found between vascular damage severity and early EPC, lateEPC, or late-TNT numbers, whereas EPC or TNT numbers and patient characteristics or cardiovascular risk factors were not associated. Except for protected patients, in all controlled hypertensive patients, early and late-EPC and early and late-TNT counts were significantly lower than those in the normotensive subjects studied (N = 30). We found that the disparity in vascular status between patients presenting with both an FS of ≥10% and scarce vascular changes and those presenting with both an FS of < 10% and severe vascular impairment is related to differences in peripheral blood EPC and TNT numbers. These observations support the role of EPCs as contributors to vascular injury repair and suggest that EPC numbers may be a potential cardiovascular risk factor to be included in the FS calculation. New & Noteworthy: As individuals who present with risk factors within acceptable or average value ranges often develop cardiovascular (CV) disease, it has been suggested that other CV risk factors need to be considered in addition to those that are commonly combined in the Framingham score (FS) to estimate the risk of general CV disease. We investigated whether peripheral endothelial progenitor cells (EPCs) and tunneling nanotubes (TNTs) deserve to be considered. Here we report that EPCs and TNTs are significantly lower in controlled hypertensive patients versus normotensive subjects and that the disparity in vascular status between patients presenting with an FS of ≥ 10% with scarce vascular changes and those presenting with an FS of < 10% with severe vascular impairment is related to differences in EPC and TNT numbers. These data point to EPC and TNT numbers as potential CV risk factors to be included in the FS calculation.Fil: De Cavanagh, Elena M. V.. No especifíca;Fil: González, Sergio Alejandro. Universidad Austral. Hospital Universitario Austral; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Inserra, Felipe. Universidad Maimónides; ArgentinaFil: Forcada, Pedro. No especifíca;Fil: Castellaro, Carlos. Universidad Austral; Argentina. Centro de Educación Medica E Invest.clinicas; ArgentinaFil: Chiabaut Svane, Jorge. Universidad Austral. Hospital Universitario Austral; ArgentinaFil: Obregón, Sebastián. Universidad Austral. Hospital Universitario Austral; ArgentinaFil: Casarini, María Jesús. No especifíca;Fil: Kempny, Pablo. Universidad Austral. Hospital Universitario Austral; ArgentinaFil: Kotliar, Carol Virginia. Universidad Austral. Hospital Universitario Austral; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

La ricostruzione dello scuotimento del terremoto del Garda del 2004 (ML=5.2)

Il terremoto di magnitudo ML=5.2 che nel 2004 ha colpito il lato occidentale del Lago di Garda (Nord Italia) viene modellato sia nell’approssimazione di sorgente puntiforme sia mediante simulazioni da sorgente estesa, al fine di investigare l’anisotropia del campo di risentimento osservata tra 5 e 15 km di distanza epicentrale. Il confronto con le osservazioni viene effettuato in termini intensità macrosismica IMCS osservata, considerando i soli comuni localizzati su roccia (o formazione «rigida») fino a 40 km dall’epicentro; un ulteriore confronto fra simulazioni e osservazioni viene effettuato utilizzando i dati registrati dalla stazione accelerometrica di Vallio Terme (GVD), localizzata a 13.3 km dall’epicentro, appartenente alla rete nazionale (RAN). Le simulazioni più semplici utilizzano una sorgente puntiforme ed equazioni predittive empiriche in termini di intensità. Le modellazioni a faglia estesa riproducono il campo di scuotimento in termini di valori di picco dello scuotimento, successivamente convertiti in intensità attraverso relazioni empiriche. Nonostante la moderata magnitudo dell’evento, le simulazioni a faglia estesa, che richiedono l’assunzione di ipotesi plausibili sia sulla geometria della sorgente che sulle proprietà di attenuazione del mezzo di propagazione, sono in grado di confermare l’anisotropia osservata della distribuzione di intensità a scala regionale (30×30 km2). Inoltre, poiché la distribuzione delle intensità presenta anche eterogeneità a scala locale (di dimensione inferiore a 3 km), probabilmente dovute ad effetti geologici e geomorfologici, oppure ad effetti di interazione terreno-struttura, nella seconda parte del lavoro vengono presentati alcuni esempi di misure di rumore sismico e di misure di frequenza propria degli edifici

Statistical modeling of ground motion relations for seismic hazard analysis

We introduce a new approach for ground motion relations (GMR) in the probabilistic seismic hazard analysis (PSHA), being influenced by the extreme value theory of mathematical statistics. Therein, we understand a GMR as a random function. We derive mathematically the principle of area-equivalence; wherein two alternative GMRs have an equivalent influence on the hazard if these GMRs have equivalent area functions. This includes local biases. An interpretation of the difference between these GMRs (an actual and a modeled one) as a random component leads to a general overestimation of residual variance and hazard. Beside this, we discuss important aspects of classical approaches and discover discrepancies with the state of the art of stochastics and statistics (model selection and significance, test of distribution assumptions, extreme value statistics). We criticize especially the assumption of logarithmic normally distributed residuals of maxima like the peak ground acceleration (PGA). The natural distribution of its individual random component (equivalent to exp(epsilon_0) of Joyner and Boore 1993) is the generalized extreme value. We show by numerical researches that the actual distribution can be hidden and a wrong distribution assumption can influence the PSHA negatively as the negligence of area equivalence does. Finally, we suggest an estimation concept for GMRs of PSHA with a regression-free variance estimation of the individual random component. We demonstrate the advantages of event-specific GMRs by analyzing data sets from the PEER strong motion database and estimate event-specific GMRs. Therein, the majority of the best models base on an anisotropic point source approach. The residual variance of logarithmized PGA is significantly smaller than in previous models. We validate the estimations for the event with the largest sample by empirical area functions. etc

Task 4 - Garda - Deliverables D14-D15: Stima degli effetti di sito

Nell’area del Garda, gli effetti di sito sono stati valutati in modo speditivo, utilizzando le informazioni geologiche e geomorfologiche di superficie insieme a misure di rumore ambientale. Dove possibile, sono stati utilizzati anche dati e informazioni disponibili dagli studi di rischio sismico della Regione Lombardia-CNR (1996). Le misure di rumore sono state effettuate nei quattro comuni prescelti: Vobarno, Salò, Toscolano Maderno e Gardone Riviera. Inoltre è stata condotta una campagna di misure lungo la Val Sabbia, dove sono stati rilevati i maggiori danni. Nel comune di Gardone Riviera è stata selezionata un’area rappresentativa dell’intero versante che va da questo comune fino a Gargnano, caratterizzato da depositi eluviali sovrastanti calcari stratificati. Come area rappresentativa dei conoidi detritici, presenti in vari comuni del lago, deposti lungo il fronte del sovrascorrimento e immergenti nel lago di Garda, è stato selezionato l’abitato di Toscolano Maderno. L’area di Vobarno si trova su depositi alluvionali recenti e terrazzati del fiume Chiese, mentre Salò è ubicatosu depositi morenici di spessore significativo (massimo un centinaio di metri) su cui poggiano depositi alluvioniali recenti. Lo scopo di questo studio è la classificazione dei suoli secondo la normativa italiana (Ordinanza PCM 3274; 2003 e Norme tecniche per le costruzioni; D.M. 14/09/05) attraverso l’utilizzo congiunto delle informazioni geologiche e della frequenza di risonanza dei depositi, calcolata attraverso i rapporti spettrali della componente orizzontale e verticale del rumore ambientale. Inoltre si è verificato se esistesse una correlazione fra dati di intensità risentita durante l’evento del 24 Novembre 2004 e le condizioni di sito, individuate utlizzando informazioni geologiche

Inflammatory intrathecal profiles and cortical damage in multiple sclerosis

OBJECTIVE: Grey matter (GM) damage and meningeal inflammation have been associated with early disease onset and a more aggressive disease course in Multiple Sclerosis (MS), but can these changes be identified in the patient early in the disease course? METHODS: To identify possible biomarkers linking meningeal inflammation, GM damage and disease severity, gene and protein expression were analysed in meninges and CSF from 27 post-mortem secondary progressive MS (SPMS) and 14 control cases. Combined cytokine/chemokine CSF profiling and 3T-MRI were performed at diagnosis in two independent cohorts of MS patients (35 and 38 subjects) and in 26 non-MS patients. RESULTS: Increased expression of pro-inflammatory cytokines (IFNγ, TNF, IL2 and IL22) and molecules related to sustained B-cell activity and lymphoid-neogenesis (CXCL13, CXCL10, LTα, IL6, IL10) was detected in the meninges and CSF of post-mortem MS cases with high levels of meningeal inflammation and GM demyelination. Similar pro-inflammatory patterns, including increased levels of CXCL13, TNF, IFNγ, CXCL12, IL6, IL8 and IL10, together with high levels of BAFF, APRIL, LIGHT, TWEAK, sTNFR1, sCD163, MMP2 and pentraxin III, were detected in the CSF of MS patients with higher levels of GM damage at diagnosis. INTERPRETATION: A common pattern of intrathecal (meninges and CSF) inflammatory profile strongly correlates with increased cortical pathology, both at time of the diagnosis and of death. These results suggest a role for detailed CSF analysis combined with MRI, as a prognostic marker for more aggressive MS. This article is protected by copyright. All rights reserved