Folded fabric tunes rock deformation and failure mode in the upper crust

The micro-mechanisms of brittle failure affect the bulk mechanical behaviour and permeability of crustal rocks. In low-porosity crystalline rocks, these mechanisms are related to mineralogy and fabric anisotropy, while confining pressure, temperature and strain rates regulate the transition from brittle to ductile behaviour. However, the effects of folded anisotropic fabrics, widespread in orogenic settings, on the mechanical behaviour of crustal rocks are largely unknown. Here we explore the deformation and failure behaviour of a representative folded gneiss, by combining the results of triaxial deformation experiments carried out while monitoring microseismicity with microstructural and damage proxies analyses. We show that folded crystalline rocks in upper crustal conditions exhibit dramatic strength heterogeneity and contrasting failure modes at identical confining pressure and room temperature, depending on the geometrical relationships between stress and two different anisotropies associated to the folded rock fabric. These anisotropies modulate the competition among quartz- and mica-dominated microscopic damage processes, resulting in transitional brittle to semi-brittle modes under P and T much lower than expected. This has significant implications on scales relevant to seismicity, energy resources, engineering applications and geohazards

Approccio alla caratterizzazione di un lembo di bosco vetusto: il caso di Monte Egitto

An integrated approach to characterize an old growth forest patch; the Monte Egitto case study Old growth forests, i.e. forests which have achieved a remarkable age without or with a very limited disturbance, are nowadays subject of detailed studies in order to understand their characters and capacity of ecosystems services providing. In Sicily only few wooded areas are classified as old growth forest, following the heavy land use change toward agriculture during the centuries. This paper reports the results of a study carried out to characterize the vegetation of a little crater on the Mount Etna, where a residual open wood of Quercus congesta (an endemic oak of Southern Italy) survived the year 1651 lava flows surrounding the crater. About 35 years ago inside the crater some areas were planted with Calabrian Black Pine. As a consequence today there is a remarkable competition between trees of the two species. An integrated approach monitoring was adopted, taking into account both trees and understory (herbs, shrubs and tree regeneration) characters as well as bird fauna, in order to describe the current situation and monitor the effect of pine plantation thinning aimed at favouring oak regeneration and reducing pine-oak competition

The brittle-ductile transition in active volcanoes

Abstract Contrasting deformation mechanisms precede volcanic eruptions and control precursory signals. Density increase and high uplifts consistent with magma intrusion and pressurization are in contrast with dilatant responses and reduced surface uplifts observed before eruptions. We investigate the impact that the rheology of rocks constituting the volcanic edifice has on the deformation mechanisms preceding eruptions. We propose a model for the pressure and temperature dependent brittle-ductile transition through which we build a strength profile of the shallow crust in two idealized volcanic settings (igneous and sedimentary basement). We have performed finite element analyses in coupled thermo-hydro-mechanical conditions to investigate the influence of static diking on the local brittle-ductile transition. Our results show that in active volcanoes: (i) dilatancy is an appropriate indicator for the brittle-ductile transition; (ii) the predicted depth of the brittle-ductile transition agrees with the observed attenuated seismicity; (iii) seismicity associated with diking is likely to be affected by ductile deformation mode caused by the local temperature increase; (iv) if failure occurs within the edifice, it is likely to be brittle-dilatant with strength and stiffness reduction that blocks stress transfers within the volcanic edifice, ultimately damping surface uplifts

Influence of perineural invasion in predicting overall survival and disease-free survival in patients With locally advanced gastric cancer

Background The aim of the present study was to evaluate the prognostic significance of perineural invasion (PNI) in locally advanced gastric cancer patients who underwent D2 gastrectomy and adjuvant chemotherapy. Methods The records of a series of 103 patients undergoing D2 gastrectomy with curative intent combined with adjuvant chemotherapy from January 2004 to December 2014 were retrospectively reviewed. Results PNI was positive in 47 (45.6%) specimens. The 1-, 3-, and 5-year overall survival rates were 81%, 55%, and 42%, respectively. The 1-, 3-, and 5-year disease-free survival (DFS) rates were 76%, 57%, and 49%, respectively. A multivariate analysis showed that age number of positive lymph nodes, T stage, and PNI were independently associated with overall survival. Regarding DFS, the multivariate analysis showed that only PNI was independently associated with DFS. Conclusions PNI and T stage and positive lymph nodes are independent markers of poor prognosis in patients with gastric cancer. PNI should be incorporated in the postoperative staging system for planning follow-up after surgery and in our opinion to propose more aggressive postoperative therapies in PNI-positive patients

Analysis of Self-Organized Criticality in the Olami-Feder-Christensen model and in real earthquakes

We perform a new analysis on the dissipative Olami-Feder-Christensen model on a small world topology considering avalanche size differences. We show that when criticality appears the Probability Density Functions (PDFs) for the avalanche size differences at different times have fat tails with a q-Gaussian shape. This behaviour does not depend on the time interval adopted and is found also when considering energy differences between real earthquakes. Such a result can be analytically understood if the sizes (released energies) of the avalanches (earthquakes) have no correlations. Our findings support the hypothesis that a self-organized criticality mechanism with long-range interactions is at the origin of seismic events and indicate that it is not possible to predict the magnitude of the next earthquake knowing those of the previous ones.Comment: 5 pages, 3 figures. New version accepted for publication on PRE Rapid Communication

Physical properties of seismogenic Triassic evaporites in the northern Appennines (Central Italy)

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Enhancing the significance of gravitational wave bursts through signal classification

The quest to observe gravitational waves challenges our ability to discriminate signals from detector noise. This issue is especially relevant for transient gravitational waves searches with a robust eyes wide open approach, the so called all- sky burst searches. Here we show how signal classification methods inspired by broad astrophysical characteristics can be implemented in all-sky burst searches preserving their generality. In our case study, we apply a multivariate analyses based on artificial neural networks to classify waves emitted in compact binary coalescences. We enhance by orders of magnitude the significance of signals belonging to this broad astrophysical class against the noise background. Alternatively, at a given level of mis-classification of noise events, we can detect about 1/4 more of the total signal population. We also show that a more general strategy of signal classification can actually be performed, by testing the ability of artificial neural networks in discriminating different signal classes. The possible impact on future observations by the LIGO-Virgo network of detectors is discussed by analysing recoloured noise from previous LIGO-Virgo data with coherent WaveBurst, one of the flagship pipelines dedicated to all-sky searches for transient gravitational waves

Recent Decisions

Admiralty--Damages in a Maritime Collision or Stranding Caused by Mutual Fault Must be Apportioned According to the Comparative Negligence of the Parties Anne Markey ============================= Admiralty--Wrongful Death--General Maritime Law Provides Remedy for Pain and Suffering of Decedent Incurred in Wrongful Death on High Seas but not for Funeral Expenses James F. Maddox ============================= Arbitration--Securities Regulation--In International Sale of Securities, Arbitration Agreement is Binding not Withstanding Non-Waiverability of Judicial Remedy of Securities Exchange Act of 1934 Thomas C. Eklund ============================= IMMIGRATION--ALIEN COMMUTERS, BOTH DAILY AND SEASONAL, WHO HAVE ONCE OBTAINED THE STATUS OF IMMIGRANTS ARE PROPERLY CLASSIFIED AS SPECIAL IMMIGRANTS LAWFULLY ADMITTED FOR PERMANENT RESIDENCE RETURNING FROM A TEMPORARY VISIT ABROAD Thomas F. Taylor ============================ INSURANCE--WAR RISK EXCLUSION CLAUSE DOES NOT BAR RECOVERY UNDER AN ALL RISK POLICY FOR DAMAGES RESULTING FROM TERRORIST ACTIVITIES Ralph Vinciguerra ============================ INTERNATIONAL ARBITRATION--U.N. CONVENTION ON THE RECOGNITION AND ENFORCEMENT OF FOREIGN ARBITRAL AWARDS--DEFENSES RAISED AGAINST ENFORCEMENT OF FOREIGN ARBITRAL AWARD WILL BE NARROWLY CONSTRUED BY U.S. COURTS TO COMPLY WITH PRO-ENFORCEMENT POLICY OF THE CONVENTION Clark Mervi

Salmeterol and formoterol in partially reversible severe chronic obstructive pulmonary disease: a dose-response study

AbstractWhen testing the response to β2-agonist drugs in severe chronic obstructive pulmonary disease (COPD), a dose-response assessment should be undertaken. This study compares the time course of inhaled salmeterol (25, 50 and 75 μg) and formoterol (12, 24 and 36 μg) at different doses in a group of 12 patients with partially reversible, but severe COPD (FEV1 of 12–32% of predicted values after β2-agonist drugs had been withheld for 24 h). All doses of salmeterol and formoterol induced a significant (P<0·01) spirometric improvement over the 12-h monitoring period, when compared to the spirometric improvement after placebo, but while formoterol induced a dose-dependent increase of the FVC, FEV1 and FEF50, this was not the case for salmeterol. In fact, 75 μg salmeterol did not produce a further improvement of these parameters. Mean peak bronchodilation, expressed as the increase in FEV1 over baseline values, occurred 2 h after inhalation of the three doses of salmeterol, and 1 h after inhalation of the three doses of formoterol. A comparison of 50 μg salmeterol with 12 μg or 24 μg formoterol (clinically recommended doses), showed that improvement of FEV1 after salmeterol was statistically (P<0·05) higher than that after the two doses of formoterol, although the mean peak bronchodilations were similar. This was because salmeterol has a longer duration of action than formoterol. These data demonstrate that salmeterol is equally effective as, but longer-acting than, formoterol at clinically recommended doses in patients suffering from COPD, with severe airway obstruction. Moreover, these data suggest that 50 μg is the best dosage for salmeterol in these patients