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Mechanical metamaterials are artificial structures that exhibit unusual mechanical properties at the macroscopic level due to architected geometric design at the microscopic level. With rapid advancement of multi-material 3D printing techniques, it is possible to design mechanical metamaterials by varying spatial distributions of different base materials within a representative volume element (RVE), which is then periodically arranged into a lattice structure. The design problem is challenging, however, considering the wide design space of potentially infinitely many configurations of multi-material RVEs. We propose an optimization framework that automates the design flow. We adopt variational autoencoder (VAE), a machine learning generative model to learn a latent, reduced representation of a given RVE configuration. The reduced design space allows to perform Bayesian optimization (BayesOpt), a sequential optimization strategy, for the multi-material design problems. In this work, we select two base materials with distinct elastic moduli and use the proposed optimization scheme to design a composite solid that achieves a prescribed set of macroscopic elastic moduli. We fabricated optimal samples with multi-material 3D printing and performed experimental validation, showing that the optimization framework is reliable.

Crack path instabilities are observed in rapidly quenched rectangular glass plates whereby wavy crack patterns form as a result of the induced temperature gradients. The peculiar characteristic of these instabilities is that the speed of propagation is several order of magnitudes lower that the Rayleigh wave speed. Experimental studies have shown the dependence of the instabilities on certain geometrical, material, and experimental parameters (e.g. plate width, material toughness, speed of quenching). By perturbing these parameters cracks are observed to propagate along a straight line, oscillate with a periodic sinusoidal or semi-circle like morphology, or propagate in a supercritical manner. Here we formulate the problem of a propagating crack in a brittle thermoelastic material while considering the possibility of the crack undergoing bursts of supercritical crack propagation, by extending the model in Negri and Ortner (2008). We also describe a novel higher order computational framework for its numerical solution centered around Universal Meshes, Mapped Finite Element Methods, and Interaction Integral Functionals. We verify the convergence of the results and compare them against experiments. We reveal crack behaviors not previously observed. Particularly we discuss periods of sudden crack propagation, followed by temporary arrest and crack kinking. We identify various crack morphologies: sinusoidal, asymmetric, semi-circle, kinked and flattened oscillations. We investigate the frequency content of the oscillatory crack paths and study their relation to the dominating problem parameters. Additionally, we identify two new thresholds in phase space corresponding to the transition from oscillatory propagation to rapid propagation and arrest, as well as from permanent crack arrest to temporary crack arrest followed by kinking and branching.

Introduction Intracranial stereotactic radiosurgery (SRS) is a technique to deliver an ablative radiation dose with an extremely sharp dose gradient to small brain tumors. In this study the accuracy of the dose delivered in SRS by a non conventional radiotherapy machine, the TomoTherapy Hi-Art System, was investigated using an "end-to-end" test using alanine pellets and gafchromic films. Methods Dose verifications were made using alanine dosimeters placed in an antropomorphic head phantom (Alderson Rando Phantom) under different treatment conditions in case of both single and multiple brain tumors. 1.25mm slice kVCT scan of the phantom was used to generate SRS plans on the TomoTherapy Planning Station platform. Commercial alanine dosimeters (Synergy Health, Germany) were irradiated in various positions of the phantom. EPR measurements were carried out through Bruker spectrometer at room temperature. Results The dose values for 6 different possible clinical scenarios characterized by the presence of one, two or three tumor lesions were reconstructed by means of alanine dosimeters and gafchromic films. The dose values measured through both experimental techniques show a good agreement with the dose values calculated by the TomoTherapy Treatment Planning System, for both tumors and organs at risk (such as optical chiasma and brain stem). Conclusion Alanine absolute dose measurements showed to be useful for the dosimetric validation of HT SRS treatments.

The direction of extension and the architecture of the Messinian basins of the Central Mediterranean region is a controversial issue. By combining original stratigraphic analysis of wells and seismic profiles collected offshore and onshore Calabria, we reassess the tectonic evolution that controlled the sedimentation and basement deformation during Messinian times. Three main deep sedimentary basins in the Calabria area record a Messinian succession formed by two clays/shales-dominated subunits subdivided by a halite-dominated subunit. The correlation with the worldwide recognized stratigraphic features permit to define the chronology of the stratigraphic and tectonic events. Three main rift basins that opened in a N-S direction have been recognized. On the contrary a fourth supradetachment basin opened toward the East. We found that the basin subsidence was controlled by two stages of activity of normal faults and that Messinian rift basins evolve in a deep-water environment. The overall pattern of extensional faults of the Central Mediterranean corresponds to normal faults striking parallel to the trench and normal faults striking at an oblique angle to the trench (Fig. 14). In particular in Campania and Calabria regions are present two rifts parallel to trench and an intervening rift orthogonal to the trench. We maintain that the recognized Messinian rift basins can be interpreted according to the “Double-door saloon tectonics”.

SUMMARY The use of the interaction integral to compute stress intensity factors around a crack tip requires selecting an auxiliary eld and a material variation eld. We formulate a family of these elds accounting for the curvilinear nature of cracks that, in conjunction with a discrete formulation of the interaction integral, yield optimally convergent stress intensity factors. We formulate three pairs of auxiliary and material variation elds chosen to yield a simple expression of the interaction integral for dierent classes of problems. The formulation accounts for crack face tractions and body forces. Distinct features of the elds are their ease of construction and implementation. The resulting stress intensity factors are observed converging at a rate that doubles the one of the stress eld. We provide a sketch of the theoretical justication for the observed convergence rates, and discuss issues such as quadratures and domain approximations needed to attain such convergent behavior. Through two representative examples, a circular arc crack and a loaded power function crack, we illustrate the convergence rates of the computed stress intensity factors. The numerical results also show the independence of the method on the size of the domain of integration. Received . . .

Einstein's perihelion advance formula can be given a geometric interpretation in terms of the curvature of the ellipse. The formula can be obtained by splitting the constant term of an auxiliary polar equation for an elliptical orbit into two parts that, when combined, lead to the expression of this relativistic effect. Using this idea, we develop a general method for dealing with orbital precession in the presence of central perturbing forces, and apply the method to the determination of the total (relativistic plus Newtonian) secular perihelion advance of the planet Mercury.

The southern Apulia foreland recorded a strong (Imax=X MCS) earthquake in 1743 and a concomitant tsunami, which struck the southeastern Salento coast. The seismo-genetic fault and the triggering factors of the tsunami are unknown. Three-dimensional interpretation of multichannel seismic profiles calibrated by wells using a GIS software enabled the recognition of the stratigraphic succession, structural framework, and submarine landslides offshore Salento. A thin Pliocene unit overlying the Mesozoic-Cenozoic substrate is covered by a Pleistocene succession separated by a Middle Pleistocene unconformity that formed during the regional uplift of Salento. The latter gave rise to the morphologic conditions for the deposition of a prograding wedge off the Salento coast, with a shelf break located at 150 m depth. Normal faults, mainly oriented NW-SE, displaced the early Lower Pleistocene succession and are buried by younger deposits. Since the Middle Pleistocene, a compressional event gave rise to the Apulia uplift and large folds and basement-involved reverse faults that are active in the eastern part of Apulia. A huge (58 km(3)) slump affecting the Middle Pleistocene prograding wedge has been documented offshore the southeast coast of Salento. The proposed geological scenario of the 1743 earthquake and subsequent tsunami is (1) an initial strong earthquake (Imax=X MCS) associated with a thrust fault located in the eastern sector of the Apulia offshore, (2) a shacking-induced large-volume slump offshore Otranto, and (3) landslide-triggered tsunamis that struck the Salento coast.

The Southern Tyrrhenian Sea is an extensional basins linked to the Neogene evolution of the Calabria subduction zone located in the western Mediterranean realm where controversial kinematic and geodynamical models have been proposed. Our study provides a key to unravel timing and mode of extension of the upper plate and the breakup of Calabria from Sardinia. By combining original stratigraphic analysis of wells and seismic profiles off Calabria with a stratigraphic correlation to onshore outcrops, we re-assess the tectonic evolution that controlled the sedimentation and basement deformation of the Southern Tyrrhenian basin during Serravallian–Tortonian times. We document the tectono-stratigraphic evolution of adjacent extensional basins characterized by 3rd order depositional sequences (Ser1, Tor1 and Tor2) and different modes of extension, subsidence and opposite dipping faults. Episodic basin development is recorded by a coarsening-up and fining-up trend of the sedimentary succession and by tectonically enhanced unconformities that reflect three episodes of fault activity. We reconstruct Serravallian–Tortonian paleogeographic maps and propose a block faulting model for the evolution of the Sardinia–Calabria area. Sardinia was disconnected from Calabria through N–S normal faults forming Tyrrhenian extensional basins that formed contemporaneously to the E–W opening of the Algerian basin. Unlike published Serravallian–Tortonian reconstructions of the western Mediterranean realm, our results support a geodynamic model characterized by rapid trench retreat, trench-normal extension in the entire overriding plate and very weak coupling between plates.

Summary We formulate a class of delicately controlled problems to model the kink-free evolution of quasistatic cracks in brittle, isotropic, linearly elastic materials in two dimensions. The evolving crack satisfies familiar principles—Griffith's criterion, local symmetry, and irreversibility. A novel feature of the formulation is that in addition to the crack path, the loading is also treated as an unknown. Specifically, a scaling factor for prescribed Dirichlet and Neumann boundary conditions is computed as part of the solution to yield an always-propagating and ostensibly kink-free crack and a continuous loading history beyond the initial step. A dimensionless statement of the problem depends only on the Poisson's ratio of a homogeneous material, and is in particular, independent of its Young's modulus and fracture toughness. Numerical resolution of the formulated problem relies on two new ideas. The first is an algorithm to compute triangulations conforming to cracked domains by locally deforming a given background mesh in the vicinity of evolving cracks. The algorithm is robust under mild assumptions on the sizes and angles of triangles near the crack and its smoothness. Hence, a subset, if not the entire family, of cracked domains realized during the course of a simulation can be discretized with the same background mesh; we term the latter a universal mesh for such a family of domains. Universal meshes facilitate adopting a discrete representation for the crack (as splines in our examples), preclude the need for local splitting/retriangulation operations, liberate the crack from following directions prescribed by the mesh, and enable the adoption of standard FEMs to compute the elastic fields in the cracked solid. Second, we employ a method specifically designed to approximate the stress intensity factors for curvilinear cracks. We examine the performance of the resulting numerical method with detailed examples, including comparisons with an exact solution of a crack propagating along a circular arc (which we construct) and comparisons with experimental fracture paths. In all cases, we observe convergence of computed paths, their derivatives, and loading histories with refinement of the universal mesh. Copyright © 2014 John Wiley & Sons, Ltd.

We assessed the prevalence of gallbladder disease (i.e. gallstones plus cholecystectomy) among patients with liver disease and its association with the severity and aetiology of hepatic injury. Subjects, referred to 79 Italian hospitals, were enrolled in a 6-month period. The independent effect of the severity and aetiology of liver disease on gallstone disease prevalence was assessed by multiple logistic regression analysis. Overall, 4867 subjects tested anti-hepatitis C virus (HCV) positive alone, 839 were hepatitis B virus surface antigen (HBsAg) alone, and 652 had an excessive alcohol intake. The prevalence of gallstone disease was 23.3% in anti-HCV-positive patients, 12.4% in HBsAg positive and 24.2% in subjects reporting excessive alcohol intake, respectively. Gallstone disease prevalence increased by age in each aetiological category. The proportion of patients with gallstone disease who had a cholecystectomy was the highest in HCV+ subjects. After adjusting for the confounding effect of age and body mass index, compared with patients with less severe liver disease, subjects with HCV-related cirrhosis, but not those with alcohol-related cirrhosis, were more likely to have gallstone disease. Subjects with HCV-related cirrhosis (OR 2.13, 95% CI: 1.38-3.26) were more likely to have gallstone disease when compared with those with HBV-related cirrhosis. HCV infection is a risk factor for gallstone disease. In Italy, the high prevalence of HCV infection among cirrhotic patients has important implications, as cholecystectomy in these subjects is associated with high risk of morbidity and mortality. © 2007 The Authors.

Current models for the opening of the Tyrrhenian Sea invoke a unique extension vector throughout the rift to drift process, accommodated by margin parallel faults, but the role of the Campania margin faults in the opening of the Tyrrhenian back-arc basin is still poorly constrained. Gaeta Bay, located on the Campania mar- gin, was investigated through the interpretation of seismic reflection and borehole data together with a strat- igraphic correlation of dated outcropping units. The interpretation of a seismic grid using seismic and sequence stratigraphy and structural geology approaches in a dedicated GIS environment led to the genera- tion of 2-D models of relevant geological surfaces, isochron maps, a 3-D digital model of the subsurface and to the reconstruction of the geological evolution of the margin with a resolution of 100 ka. Gaeta Bay is formed by three basins (northern, central and southern) and features a complex stratigraphic architecture: in the northern and central basins a syn-rift deposit (unit PP) is buried by the oldest aggradational deposit (unit A) that fills the accommodation space; a post 0.7 Ma succession (units B and C) filled the northern basin with a lateral aggradational geometry; a syn-tectonic wedge (unit B) was deposited in the central basin between 0.7 and 0.4 Ma; post 0.4 Ma thick deposits (unit C) are testimony to the collapse of the southern basin. A correlation between the geology of the bathyal basin and that of the Campania margin was established using a CROP seismic section that extended from the Vavilov basin to Gaeta Bay. Based on original and literature data we propose a kinematic evolution of the Tyrrhenian Sea upper plate over the last 10 Ma. This evolution consists of older extensional events (stages 1-2) off Sardinia and in the Vavilov basin (leaving the Campania margin unaffected). Younger events (stages 3-5) developed in the eastern (with a Pliocene-Quaternary change of the extension direction along the Campania Margin) and central Tyrrhenian region. This paper suggests that the Tyrrhenian Sea opening was a polyphase rifting with a migration of activity and a change of style over time (including a period of lithospheric detachment faulting). © 2013 Elsevier B.V. All rights reserved.

Marginal wharves are key components in providing functionality of port facilities. Ports are central components of the United States economy. Earthquake damage to a port can disrupt the economic stability. Therefore port facilities must be able to quickly return to full operation shortly after a seismic event. Prior studies have shown that integrity of marginal wharves may be compromised by excessive soil movement and structural damage. The latter is often localized at pile-to-wharf connections and in the pile body buried within the soil. Recent research has resulted in an improved connection design which mitigates damage. This study was undertaken to evaluate the full seismic performance of marginal wharves including both conventional and damage resisting connections. A series of finite element (FE) models of a representative pile supported wharf facility were created. The models varied in their moment resisting pile-to-wharf connections. A total stress analysis approach was used to capture the soil response along with p-y, t-z and Q-z soil-structure interaction (SSI) springs. Validated connection interface elements were integrated with non-linear frame elements to simulate the marginal wharf structure and substructure. Non-linear static pushover and dynamic time history analyses, for three different hazard levels, were performed. The results of the numerical simulations were used to assess the performance of the marginal wharf including estimates of crane damage and port downtime. Copyright c © 2011 John Wiley & Sons, Ltd.

Objectives To longitudinally map the onset and identify risk factors for skin sclerosis and digital ulcers (DUs) in patients with systemic sclerosis (SSc) from an early time point after the onset of Raynaud9s phenomenon (RP) in the European Scleroderma Trials and Research (EUSTAR) cohort. Methods 695 patients with SSc with a baseline visit within 1 year after RP onset were followed in the prospective multinational EUSTAR database. During the 10-year observation period, cumulative probabilities of cutaneous lesions were assessed with the Kaplan–Meier method. Cox proportional hazards regression analysis was used to evaluate risk factors. Results The median modified Rodnan skin score (mRSS) peaked 1 year after RP onset, and was 15 points. The 1-year probability to develop an mRSS ≥2 in at least one area of the arms and legs was 69% and 25%, respectively. Twenty-five per cent of patients developed diffuse cutaneous involvement in the first year after RP onset. This probability increased to 36% during the subsequent 2 years. Only 6% of patients developed diffuse cutaneous SSc thereafter. The probability to develop DUs increased to a maximum of 70% at the end of the 10-year observation. The main factors associated with diffuse cutaneous SSc were the presence of anti-RNA polymerase III autoantibodies, followed by antitopoisomerase autoantibodies and male sex. The main factor associated with incident DUs was the presence of antitopoisomerase autoantibodies. Conclusion Early after RP onset, cutaneous manifestations exhibit rapid kinetics in SSc. This should be accounted for in clinical trials aiming to prevent skin worsening.

Universal meshes have recently appeared in the literature as a computationally efficient and robust paradigm for the generation of conforming simplicial meshes for domains with evolving boundaries. The main idea behind a universal mesh is to immerse the moving boundary in a background mesh (the universal mesh), and to produce a mesh that conforms to the moving boundary at any given time by adjusting a few elements of the background mesh. In this manuscript we present the application of universal meshes to the simulation of brittle fracturing. To this extent, we provide a high level description of a crack propagation algorithm and showcase its capabilities. Alongside universal meshes for the simulation of brittle fracture, we provide other examples for which universal meshes prove to be a powerful tool, namely fluid flow past moving obstacles. Lastly, we conclude the manuscript with some remarks on the current state of universal meshes and future directions.

The style of extensional basins provides key insights into the magnitude of extension and their kinematic evolution. The newly documented Stilo rift (off Calabria, Italy) features a Serravallian–Tortonian rift basin bounded by a high-angle normal fault and a Messinian adjacent supradetachment basin bounded by a low-angle normal fault. We propose a kinematic model suggesting the abandonment of the high-angle normal fault and the beginning of low-angle normal fault activity, followed by a rapid increase in extension. The triggering mechanism of the low-angle normal faults can be attributed to rapid rollback of the subducting plate and/or to isostatic crustal uplift. Supplementary material: The seismic dataset and methods of interpretation are available at http://www.geolsoc.org.uk/SUP18794.

The relativistic precession can be quickly inferred from the nonlinear polar orbit equation without actually solving it., Accepted for publication in Astrophysics & Space Science

Stem/progenitors have been identified intrahepatically in the canals of Hering and extrahepatically in glands of the biliary tree. Glands of the biliary tree (peribiliary glands) are tubulo-alveolar glands with mucinous and serous acini, located deep within intrahepatic and extrahepatic bile ducts. We have shown that biliary tree stem/progenitors (BTSCs) are multipotent, giving rise in vitro and in vivo to hepatocytes, cholangiocytes or pancreatic islets. Cells with the phenotype of BTSCs are located at the bottom of the peribiliary glands near the fibromuscular layer. They are phenotypically heterogeneous, expressing transcription factors as well as surface and cytoplasmic markers for stem/progenitors of liver (e.g. SOX9/17), pancreas (e.g. PDX1) and endoderm (e.g. SOX17, EpCAM, NCAM, CXCR4, Lgr5, OCT4) but not for mature markers (e.g. albumin, secretin receptor or insulin). Subpopulations co-expressing liver and pancreatic markers (e.g. PDX1+/SOX17+) are EpCAM+/−, and are assumed to be the most primitive of the BTSC subpopulations. Their descendants undergo a maturational lineage process from the interior to the surface of ducts and vary in the mature cells generated: pancreatic cells in hepatopancreatic ducts, liver cells in large intrahepatic bile ducts, and bile duct cells along most of the biliary tree. We hypothesize that there is ongoing organogenesis throughout life, with BTSCs giving rise to hepatic stem cells in the canals of Hering and to committed progenitors within the pancreas. The BTSCs are likely to be central to normal tissue turnover and injury repair and to be key elements in the pathophysiology of liver, pancreas and biliary tree diseases, including oncogenesis.

Since the early days of the Internet, network traffic monitoring has always played a strategic role in understanding and characterizing users? activities. In this article, we present our experience in engineering and deploying Tstat, an open source passive monitoring tool that has been developed in the past 10 years. Started as a scalable tool to continuously monitor packets that flow on a link, Tstat has evolved into a complex application that gives network researchers and operators the possibility to derive extended and complex measurements thanks to advanced traffic classifiers. After discussing Tstat capabilities and internal design, we present some examples of measurements collected deploying Tstat at the edge of several ISP networks in past years. While other works report a continuous decline of P2P traffic with streaming and file hosting services rapidly increasing in popularity, the results presented in this article picture a different scenario. First, P2P decline has stopped, and in the last months of 2010 there was a counter tendency to increase P2P traffic over UDP, so the common belief that UDP traffic is negligible is not true anymore. Furthermore, streaming and file hosting applications have either stabilized or are experiencing decreasing traffic shares. We then discuss the scalability issues software-based tools have to cope with when deployed in real networks, showing the importance of properly identifying bottlenecks.

Three crustal geological sections of the Campanian Volcanic Zone (Italy) were reconstructed by integrating basin architecture and deep well stratigraphies. In addition, mapping of the fault system and of large-volume ignimbrites was carried out. A linked fault system has been identified, which was responsible for asymmetric subsidence contemporaneous with the eruption of ignimbrites. Late Quaternary extension is characterized by a WNW–ESE stretching axis, NNE–SSW normal faults and reactivation of inherited structures. Structural, stratigraphic and palaeogeographical analyses reveal evidence for up to 750 m of subsidence, which has occurred at a mean rate of up to 4.9 mm a −1 over the past 154 ka. These rates suggest that extensional tectonics was responsible for the regional subsidence. A 6 km deep seismic reflector was associated with a magmatic reservoir underlying Campi Flegrei. By matching the structural and stratigraphic architecture with published geophysical and geochemical data a crustal tectonomagmatic model was constructed that displays high-angle faults that root into a low-angle detachment, which in turn roots into a deep sill-like magma reservoir. This model suggests the possible role of extensional faults in localizing magmatic activity, as faults controlled magma rise from deep to shallow reservoirs and to the surface during ignimbrite eruptions. Supplementary material: Seismic reflection profiles and interpretations are available at http://www.geolsoc.org.uk/SUP18451.

Magnetic resonance imaging requested for a potentially serious indication, provided a unique opportunity to explore the intervillous circulation of placentas from pregnancies complicated by Intra Uterine Growth Restriction (IUGR) and to compare them to normal cases. This allowed an innovative characterization of in vivo utero-placental blood flow, correlating a compromised intervillous circulation in IUGR to the deterioration of fetal condition. MR imaging was requested to rule out suspected posterior placental adhesive disorders in 26 patients. Twelve patients had fetuses appropriate for gestational age, while in 14 patients fetuses were affected by severe IUGR. Multiphasic dynamic contrast-enhanced sagittal sequences were acquired and a quantitative analysis of signal intensity and enhancement kinetics was performed for both the entire placenta and for selected regions. Images disclosed a homogeneous perfusion overall the placenta in normal cases, while IUGR placentas displayed a slow intervillous blood flow, along with many patchy unperfused areas. Intermittent stops worsen the perfusion dynamics of the intervillous mostly in IUGR cases with an elevated ductus venosus pulsatility index. In conclusion, we proved that in IUGR placenta maternal placental blood flow is extremely compromised and that superimposed dynamic phenomena concur to worsen the intervillous circulation leading to an end-stage fetal decompensation.

Human cytomegalovirus (HCMV) is the major viral cause of birth defects worldwide. Affected infants can have temporary symptoms that resolve soon after birth, such as growth restriction, and permanent disabilities, including neurological impairment. Passive immunization of pregnant women with primary HCMV infection is a promising treatment to prevent congenital disease. To understand the effects of sustained viral replication on the placenta and passive transfer of protective antibodies, we performed immunohistological analysis of placental specimens from women with untreated congenital infection, HCMV-specific hyperimmune globulin treatment, and uninfected controls. In untreated infection, viral replication proteins were found in trophoblasts and endothelial cells of chorionic villi and uterine arteries. Associated damage included extensive fibrinoid deposits, fibrosis, avascular villi, and edema, which could impair placental functions. Vascular endothelial growth factor and its receptor fms-like tyrosine kinase 1 (Flt1) were up-regulated, and amniotic fluid contained elevated levels of soluble Flt1 (sFlt1), an antiangiogenic protein, relative to placental growth factor. With hyperimmune globulin treatment, placentas appeared uninfected, vascular endothelial growth factor and Flt1 expression was reduced, and sFlt1 levels in amniotic fluid were lower. An increase in the number of chorionic villi and blood vessels over that in controls suggested compensatory development for a hypoxia-like condition. Taken together the results indicate that antibody treatment can suppress HCMV replication and prevent placental dysfunction, thus improving fetal outcome.

The Southern Campania Margin (SCM) represents a key area of the Central Mediterranean because it records all the rifting stages of the Tyrrhenian Sea. The interpretation of a seismic dataset calibrated with deep wells and outcrops, using seismic stratigraphy and structural geology methods in a dedicated Geographic Information System (GIS) environment, the seismic depth conversion, the generation of 2-D and 3-D models led to the reconstruction of a polyphased tectono-stratigraphic evolution of the SCM. During the early stage of Tyrrhenian opening a terrigenous transtensional Basin (Langhian-Tortonian Cilento Basin) formed on the Liguride accretionary prism adjacent to the Calabria crystalline terrane. In the SCM the Liguride thrust sheets tectonically overly the Apennine Platform units and both these nappes have been dismembered by Quaternary faults. Three rifting stages, not homogeneously distributed, affected the region since the Lower Pleistocene. They are associated to the deposition of a thick Quaternary succession (A, B and C units). During these Pleistocene stages there was an abrupt change of the extension direction (from NE-SW to NW-SE) accompanying a change of the nappe transport direction of the Southern Apennines. The construction of balanced sections using dedicated software, permitted us to recognize the true geometry of the faults and compute the amount of Quaternary extension of the SCM that results comparable to those calculated for other sectors of the Tyrrhenian margin and further extensional regions worldwide.

Preterm birth causes infant morbidity and mortality. A single course of antenatal corticosteroids (ACS) should be considered routine for preterm delivery. Benefits of therapy before 34 weeks' gestation have been established for infants born between 24 h and 7 days after treatment. It is still unclear whether multiple courses (MC) of ACS should be performed in women at risk of preterm delivery 7 days or more after initial treatment.To determine the risks and benefits of MC of ACS.Search and selection for human randomized controlled trials were conducted in PubMed and The Cochrane Central Register of Controlled Trials. Statistical analysis was performed using the Review Manager 4.3 software.MC of ACS were associated with a statistically decrease in the occurrence of respiratory distress syndrome, patent ductus arteriosus, use of surfactant, ventilation support, and any maternal side effects. This treatment was also associated with a significant reduction in birth weight and head circumference.MC of ACS in women at risk of preterm birth do not offer significant benefits concerning the composite neonatal morbidity. Data on long-term safety are still insufficient. Further evaluations, most by follow-up studies, are required to study the long-term effects.

The interpretation of high-resolution seismic profiles acquired close the eastern coast of the Bay of Naples offshore Somma-Vesuvius volcano, and calibrated by borehole data, allowed us to recognize a reflection-free seismic facies consisting of a volcaniclastic debris avalanche overlain by pyroclastic density current deposits. Both are associated with the 3.5 ka 'Avellino eruption' and are in turn overlain by a marine succession. The top of the volcaniclastic unit corresponds to a deep erosional surface covered by a coarse-grained bioclastic layer with rounded pumice. We argue that these features are related to a tsunami that was triggered by the sudden entrance into the sea of the gigantic (>1km3) volcaniclastic unit. The onshore-offshore correlation and mapping of this volcaniclastic unit have allowed us to evaluate its distribution west of Somma-Vesuvius. The pyroclastic density current deposits terminate seaward at 40 m water depth; at the same depth the debris avalanche is affected by a gravitational instability. Over the last 3.5 ka the slump has been in constant movement, as documented by the angular unconformities at the top of the chaotic seismic unit and within the overlying marine deposits. © The Geological Society of London 2009.

The interpretation of high-resolution seismic profiles and core data collected in the western Somma-Vesuvius volcano documents a stratigraphic unit consisting of a voluminous debris avalanche that was covered by pyroclastic gravity current deposits after entering the sea. Based on the stratigraphic position together with the ages of the dated Somma-Vesuvius Plinian eruptions, this unit was linked to the ∼3.5 ka-old Avellino Plinian eruption and correlated and mapped in offshore and onshore areas. The deposition of the thick Avellino unit had a strong impact on the physical environment of the volcano's western sector, producing hundreds of metres of prograding coastline and the formation of a morphological barrier in the alluvial plain. The striking erosional and depositional features that characterise the top of the Avellino unit along the coast suggest that the entrance of the debris avalanche into the sea triggered a tsunami that struck the Naples Bay coast. The hazardous geologic events include both the sea-facing flank failure of the volcano (producing the debris avalanche and tsunami) and the Avellino Plinian eruption (producing pumice fall and surge clouds) that profoundly affected several human settlements located within a 20 km radius of the volcano, causing the decline of the Bronze Age communities.

The ad 79 Plinian eruption of Vesuvius that buried Pompeii and Herculaneum began with pumice falls deposited towards the SE of the volcano followed by pyroclastic currents directed towards the SW. These currents reached Herculaneum and rapidly entered the sea, forming a fan. The interpretation of seismic reflection profiles and gravity cores collected off Herculaneum documents a submarine fan-shaped pyroclastic body at 10–140 m water depth that we interpret as the submarine counterpart of the onshore pyroclastic current deposits. This fan, c . 0.3 km 3 in volume, displays a chaotic seismic facies that changes seaward to parallel reflectors and then to wavy reflectors. Gravity cores reveal a succession consisting of centimetre-thick sand- or silt-sized ash couplets followed by a graded gravelly sand-sized bed up to 180 cm thick, containing shell fragments and beach-derived pebbles, overlain by centimetre-thick graded and laminated sandy ash layers. The depositional textures and sedimentary structures of the submarine pyroclastic fan have been interpreted as the product of the interactions between pyroclasts, water waves and tsunamis induced by the ad 79 pyroclastic density currents into the Bay of Naples.

The interpretation of high-resolution seismic profiles and core data collected in the western Somma-Vesuvius volcano documents a stratigraphic unit consisting of a voluminous debris avalanche that was covered by pyroclastic gravity current deposits after entering the sea. Based on the stratigraphic position together with the ages of the dated Somma-Vesuvius Plinian eruptions, this unit was linked to the similar to 3.5 ka-old Avellino Plinian eruption and correlated and mapped in offshore and onshore areas. The deposition of the thick Avellino unit had a strong impact on the physical environment of the volcano's western sector, producing hundreds of metres of prograding coastline and the formation of a morphological barrier in the alluvial plain. The striking erosional and depositional features that characterise the top of the Avellino unit along the coast suggest that the entrance of the debris avalanche into the sea triggered a tsunami that struck the Naples Bay coast. The hazardous geologic events include both the sea-facing flank failure of the volcano (producing the debris avalanche and tsunami) and the Avellino Plinian eruption (producing pumice fall and surge clouds) that profoundly affected several human settlements located within a 20 km radius of the volcano, causing the decline of the Bronze Age communities.

It is shown how the generalized Laplace coefficients can be employed to deduce explicit formulas for ordinary and Newcomb derivatives of the Laplace coefficients.

We derive the first-order orbital equation employing a complex variable formalism. We then examine Newton’s theorem on precessing orbits and apply it to the perihelion shift of an elliptic orbit in general relativity. It is found that corrections to the inverse-square gravitational force law formally similar to that required by general relativity were suggested by Clairaut in the 18th century.

The Campania Plain is a rapidly subsiding Quaternary basin that formed on the eastern margin of the Tyrrhenian Sea in association with the younger phase of Tyrrhenian rifting. It is located in the hinge area between the Apennines fold-thrust belt and the Tyrrhenian extensional backarc basin. By combining original stratigraphic analyses of well logs and seismic profiles we built a basin subsidence curve, mapped the fault pattern of the Campania Plain and analyzed the impact of the block faulting on the sedimentology and stratigraphic architecture of the basin fill. Well data indicate that the Quaternary succession consists of offshore, shoreface and coal-bearing coastal plain deposits arranged to form thick aggradational and retrogradational units. The sequence stratigraphy interpretation of well logs permitted us to recognize thirteen depositional sequences and the stratigraphic signatures of the rift stages. The study area corresponds to a sediment overfilled/balanced infill basin type that resulted from superposition of several rifting events characterized by high rates of basin subsidence.Taking into account the geological data of the adjacent areas, we propose a Pliocene-Quaternary rifting evolution of the upper Tyrrhenian plate consisting of four episodes. Two peculiar features of the Tyrrhenian rifting are a skip of the extensional axial zone eastwards leaving the previous zone of high strain localization (Vavilov basin), followed by a dramatic change (90) of the direction of extension. Because these Tyrrhenian features cannot be accounted for by the current rifting models we hypothesized a link between the evolution of upper plate and subducting slab. The proposed geodynamic scenario is characterized by a progressive rupture of the subducting plate and formation of extensional basins in the upper plate. (C) 2015 Elsevier Ltd. All rights reserved.

Sedimentological and chemical analysis of gravity core samples, along with the interpretation of very high resolution, single channel seismic reflection profiles acquired off the Sarno prodelta system (southeastern Naples Bay), document the sedimentary facies and seismic stratigraphic signature of the tephra deposit erupted by Vesuvius during the plinian eruption of 79 AD. The 79 AD pyroclastic deposits sampled off the Sarno prodelta system revealed significantly different characters with respect to both the subaerial succession documented from the type sections of Pompeii, Herculaneum and Oplontis and the more distal pyroclastic fallout deposits that were recovered from the outer continental shelf off the northern Salerno Bay. This was likely to be expected as, in proximal subaqueous settings, both primary deposition and reworking of tephra are known to be influenced by the hydrodynamics of the water itself (induced by the pyroclastic currents entering the sea) as well as by the early instability of pyroclastic bedforms due to the exceptionally high sediment yield during volcanic eruption. According to the data illustrated and discussed in this study, we suggest that the 79 AD tephra deposit sampled off the Sarno prodelta is likely to be the result of a number of syn-eruptive genetically-related depositional and/or erosional mechanisms associated with (1) anomalous waves (tsunami) and currents generated by the entrance of pyroclastic flows and surges into the sea; (2) subaqueous density flows evolved from the impact of hot pyroclastic currents into the seawater; (3) failure of water-logged, cohesionless pumice deposits, due to instability of pyroclastic bedforms rapidly accumulating on the seafloor. Seismic interpretation revealed that the Upper Holocene sequence off the Sarno prodelta system is affected by extensive creep involving the whole post-79 AD succession. Deformation due to creep is documented by slumping of semi-consolidated strata over a basal surface represented by the lithologic discontinuity between the base of the 79 AD tephra deposits and the underlying hemipelagite. Seismic data also suggest that gravitational instability of this area has been induced, or enhanced, by significant volcanotectonic deformation and local uplift of the seafloor that ostensibly predated the eruptive event. The results of this research may be relevant to studies of other eruption events in close proximity to coastlines in terms of wave- and/or current-generated sedimentary features as a possible explanation of unusual subaqueous facies architecture.

¶The crustal structure of the Campania continental margin is synthesized from outcrop, seismic reflection and gravimetric data. Outcrop and subsurface geological data reveal the presence of NE–SW faults, E–W faults and NW–SE faults. An older extensional event occurred along NW–SE faults and was followed by the main extensional event linked to the activity of NE–SW normal faults. The latter were active between 700 and 400 ka producing half-grabens filled by more than 5 km of Quaternary deposits. The stratigraphic signature of these tectonic events corresponds to a Lower Pleistocene marine unconformity-bounded unit overlain by Middle Pleistocene rocks belonging to a transgressive-regressive cycle. A crustal section of the Campania margin displays an asymmetric linked fault system characterized by a 10–12 km-deep main detachment level, listric normal faults and rollover anticlines. Structural and stratigraphic data document that the inception of volcanic activity at Vesuvius occurred at 400 ka, just after the main extensional event, and the volcano is located at the margin of a rollover anticline.

¶The Campanian continental margin is characterised by asymmetric half grabens and large-volume volcanic deposits. Vesuvius and Campi Flegrei are active volcanoes located along the coast of Naples Bay along one of these half grabens. The interpretation of an extensive set of seismic reflection data allowed to reconstruct the stratigraphy and structural pattern in Naples Bay and their relationships with volcanism. The stratigraphic succession is characterised by a complex architecture due to the presence of 157 Ka old submarine and subaerial vents, pyroclastic flow units associated to the Campanian Ignimbrite and the Neapolitan Yellow Tuff, and numerous tuff cones younger than 12 Ka. These volcanic units occur within marine sediments deposited during the late Quaternary sea level oscillations. The structural pattern is characterised by late Quaternary NE- trending normal faults, NW-trending transtensional faults, E–W trending left-lateral faults and WNW-ESE directed folds. The overall fault kinematics and the evaluated very high displacement rates are consistent with an E-trending left-lateral transtensional shear zone located between 41° and 40° N latitude. The relationship between volcanism and tectonics in the Bay of Naples is explained with block rotation associated with this shear zone. Finally, tectonic and stratigraphic data argue against the occurrence of a caldera in the Bay of Naples.

Objective To compare the clinical manifestations and laboratory abnormalities associated with primary cytomegalovirus (CMV) infection in pregnancy with recurrent and non-active CMV infection (controls). Design A prospective cohort study. Setting Rome, Latium and other Italian regions. Population Three hundred and sixteen pregnant women with CMV infection: 102 had primary infection, 105 had recurrent infection and 109 with non-active infection were followed up as controls. Methods CMV diagnosis was based on serological examinations (CMV IgG, IgM and IgG avidity) and detection of CMV DNA by polymerase chain reaction in maternal serum, urine and cervical samples. The clinical history and laboratory evaluations were carried out at enrolment and at each subsequent visit, every one to three months. Main outcome measures Identification of clinical and laboratory indicators of primary CMV infection in pregnancy. Results Compared with women with recurrent or non-active infection, women with primary infection had a statistically significant higher prevalence of fever, asthenia, myalgia and flu-like syndrome (P Conclusion Clinical manifestations (i.e. flu-like syndrome, fever) and abnormal laboratory findings (i.e. lymphocytes ≥40%, elevated aminotransferases) may suggest the presence of primary CMV infection and should prompt subsequent virological investigations.