Shoaling Waves Interacting with an Orthogonal Current

In the present work, an experimental investigation on the hydrodynamics of shoaling waves superposed on a steady orthogonal current is carried out. An experimental campaign in a wave tank has been performed, with waves and current interacting at a right angle over a sloping planar beach. Velocity data have been gathered during the experiments in order to investigate mean, phase and turbulent flow. A detailed preliminary analysis of the time- and space-variability of the experiments is presented. Results show that a complex interaction between waves and current occurs as the wave shoals, in terms of sheer production, momentum transfer and turbulent mixing. Superposition of waves determines a shear increase at the bottom due to an enhanced turbulence mixing, nonetheless as depth decreases and the current velocity consequently increases, shoaling waves may be less efficient in enhancing shear at the bottom. Moreover, the superposition of waves determines the current to oscillate around its mean velocity value. Nevertheless, as wave shoals and simultaneously current velocity increases with decreasing depth, waves and current oscillatory motion experience a phase lag, as a response of the larger momentum of the current to the changing of the shoaling waves acceleration distribution along the wave phase. Moreover, the turbulent bursting events of the combined flow in proximity of the bed have been investigated by means of quadrant analysis, showing an increase of the turbulent ejections and sweeps due to the superposition of the shoaling waves

Context-aware Peer-to-Peer and Cooperative Positioning

Peer-to-peer and cooperative positioning represent one of the major evolutions for mass-market positioning, bringing together capabilities of Satellite Navigation and Communication Systems. It is well known that smartphones already provide user position leveraging both GNSS and information collected through the communication network (e.g., Assisted-GNSS). However, exploiting the exchange of information among close users can attain further benefits. In this paper, we deal with such an approach and show that sharing information on the environmental conditions that characterize the reception of satellite signals can be effectively exploited to improve the accuracy and availability of user positioning. This approach extends the positioning service to indoor environments and, in general, to any scenario where full visibility of the satellite constellation cannot be grante

Turbulent features of nearshore wave–current flow

Waves and currents influence nearly all nearshore physical processes. Their complex interaction gives birth to complex turbulence features that are far from being completely understood. In this regard, previous studies mainly focused on mean flow or inferred turbulent features from averaged velocities, seldom examining turbulent fluctuations. Moreover, the dynamics of wave–current flow have mostly been replicated in experimental channel setups, i.e., overlooking the natural occurrence of waves and longshore currents intersecting at a near-orthogonal angle. In the present work, the hydrodynamics of near-orthogonal wave–current interaction are investigated through a physical model study. Experiments were carried out in a laboratory basin in the presence of fixed sand and gravel beds, where current-only, wave-only, and combined flow tests were performed. Flow velocities were measured by means of acoustic Doppler velocimeters, through which time-averaged, phase-averaged, and turbulent velocities were obtained. Results revealed two main features of the wave–current flow. First, we observed that the superposition of waves does not necessarily induce an increase in the current bed shear stresses. Indeed, depending on bed roughness, current freestream velocity and wave orbital velocity, enhancements or reductions of the current bed shear were observed. Moreover, application of quadrant analysis revealed a periodic evolution of the current turbulent bursts. Specifically, the number of current turbulent ejections and sweeps is reduced or increased as the wave phase progresses from antinodes to nodes and from nodes to antinodes, respectively.</p

Expression and Localization of aquaporin‐1 in Temporomandibular Joint Disc with Internal Derangement

Background: Internal derangement is the most frequent arthropathy affecting the temporomandibular joint, where its commonest form is anterior disc displacement with or without reduction. Despite the frequency of the disorder, the biochemical features of displaced discs are still unclear. Methods: We investigated the expression pattern and localization of aquaporin‐1, an important channel protein involved in plasma membrane water permeability, in patients with anterior disc displacement (both with and without reduction), with a view to assessing the characteristics of local tissue responses to the microenvironmental changes induced by abnormal mechanical loading of the displaced disc. Protein expression was studied by immunohistochemistry in different areas of discs from 18 patients with anterior disc displacement with or without reduction and in four normal controls. Results: A greater proportion of cells immunopositive for aquaporin‐1 were detected in diseased than in normal discs. Whereas protein expression was substantially similar in the different areas of normal discs, a significantly larger number of immunopositive cells were detected in the posterior band of displaced discs without reduction and in the anterior and intermediate bands of those with reduction. Conclusions: These findings suggest that aquaporin‐1 is expressed and upregulated in temporomandibular joint with anterior disc displacement (both with and without reduction)

Structural health monitoring and earthquake early warning: preliminary studies for application in eastern Sicily

In this work, the reduction of seismic hazard in eastern Sicily is addressed by both studying the fundamental resonant frequency of strategic buildings through low cost geophysical investigation techniques, and exploring a practical approach to earthquake early warning EEW) system. The fundamental period and the corresponding amplification of some selected strategic buildings has been estimated using ambient vibration and earthquake data. We analyzed the basic dynamic parameters of buildings chosen as target, by using continuous vibration measurements at different floors. The dynamic behavior of structures was evaluated considering both small strains induced by ambient vibrations and larger excitation levels due to the earthquakes occurrence. A practical approach to earthquake early warning in the investigated area was dealt with by using empirical relationships between parameters measured on the initial portion of seismic recordings and related to the earthquake magnitude and peak ground motion. In particular, we performed the first preliminary tests by using empirical relationships calibrated for the considered area and taking into account the geometry of the existing permanent seismic network deployed in the eastern Sicily. The estimated relationships have been used to provide onsite warning around a given seismic station and evaluate the potential damaging effects. The joint of EEW system and geophysical investigation shown in this work may be deemed a useful guide for the future implementation of the in real time seismic monitoring in the region.This work has been supported by the following project: “Attività di sviluppo sperimentale finalizzata alla riduzione del rischio sismico nella Sicilia Orientale” inside the PO-FESR 2007-2013 Sicilia; MED-SUV funded from the European Union Seventh Framework Programme (FP7) under Grant agreement n°308665. This work is sponsored by European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement n° 798480. We are thankful to Salvatore Rapisarda and Danilo Contrafatto to support us in the field work

ADAM10 Localization in Temporomandibular Joint Disk with Internal Derangement: An Ex Vivo Immunohistochemical Study

The purpose of this study was to determine the presence of ADAM10 in temporomandibular joint disk with internal derangement. Twenty-five paraffin blocks of displaced temporomandibular joint (TMJ) disk specimens from earlier investigations were retrieved from the archives of the University of Catania. Of these 16 had been removed from females and 9 from males; 11 with anterior disk displacement with reduction (ADDwR) and 14 with anterior disk displacement without reduction (ADDwoR). The sections were dehydrated, embedded in paraffin and cut. Then they were incubated in 0.3% H2O2/methanol and half of sections from each sample were incubated in diluted rabbit polyclonal anti-ADAM10 antibody. Then biotinylated anti-mouse/anti-rabbit IgG was applied to the sections, followed by avidin–biotin–perioxidase complex. The results were analyzed and the results were that ADAM10 was overexpressed in the posterior band of sections from patients with ADDwR compared to the other bands of both ADDwR and ADDwoR sections. Overexpression correlated with severe histopathological degeneration. We believe these results have the potential to provide insights into the pathogenesis of TMJ disk degeneration and to help design new therapeutic approaches targeting the proteolytic events that lead to tissue degeneration. Early therapeutic block of ADAM10 activity could succeed in limiting aggrecan-rich matrix breakdown without affecting normal physiology

Aquaporin 1 expression in human normal temporomandibular disc

The aquaporins (AQPs) are a family of hydrophobic membrane channel proteins that are expressed in many epithelial, endothelial and other tissues and that participate in many physiological and pathological processes. In particular aquaporin-1 (AQP1), a member of this family proteins, is expressed by the masseter and infrahyoid muscles, meckel’s cartilage and submandibular gland. Literature data on the role and the localization of AQP1 in articular joints are very poor, and none providing data on the normal temporomandibular joint (TMJ) disc. Accordantly, the present paper prompted this immunohistochemical and western blotting investigation, on the presence and distribution of AQP1 in human TMJ discs without any degenerative changes, in order to elucidate further aspects of the TMJ homeostasis system and disc tribology. Twelve TMJ discs, were obtained bilaterally from six cadavers and they were processed for immunohistochemical and Western Blot analysis. The results showed an AQP1 immunoexpression in few fibroblasts-like cells and fibrochondrocytes of normal human TMJ discs demonstrating a constitutive expression of this protein. No difference between the disc regions was seen in normal specimens. Western blot analysis of disc samples confirm the physiological AQP1 expression. In this view it appears reasonable a physiological expression of AQP1 by TMJ fibrocartilage cells and interpretable as a physiological mechanism of tissue homeostasis. Further future interesting studies could be conducted to elucidate the full AQPs profile in TMJ pathological disc investigating their change of the expression patterns during TMJ disc diseases

Lubricin in synovial fluid of mild and severe temporomandibular joint internal derangements

To understand the molecular basis of temporomandibular joint (TMJ) pathologies, we aimed to investigate the lubricin levels in the TMJ synovial fluid (SF) of patients with mild to severe internal derangements (IDs). A total, 34 joints were the study group. Only patients, with a Wilkes stage of III, IV and V were included, in this sample. Control group consisted of SF from eight joints, from patients undergoing to orthognatic surgery. Concentrations of lubricin in the SF from both samples were measured using ELISA system. The mean lubricin concentration was 7.029 ± 0.21 µg/mL in stage III patients; 5.64 ± 0.10 µg/mL in stage IV patients, and 4.78 ± 0.11 µg/mL in stage V patients. The lubricin levels from stage IV and stage V patients differed significantly (P ? 0.001) from those of control subjects. Lubricin levels were inversely correlated with age and to VAS score. The results of this cross-sectional study highlight the relationship between disease severity and the levels of lubricin in TMJ SF. Our findings suggest that novel biotherapeutic approaches, including the administration of recombinant lubricin in the joint cavity, for the treatment of TMJ diseases can be developed

Caseous calcification of the mitral annulus with mitral regurgitation and impairment of functional capacity: a case report

<p>Abstract</p> <p>Introduction</p> <p>Mitral annular calcification is a common echocardiographic finding, especially in the elderly. Caseous calcification of the mitral annulus, however, is a relatively rare variant, having an echocardiographic prevalence of 0.6% in patients with mitral annular calcification. Caseous calcification needs to be differentiated from infected mitral annular calcification, mitral annular abscess and tumours. It is not malignant, and medical therapy with clinical follow-up is the therapeutic option. Surgery should be reserved for co-existent mitral valve dysfunction.</p> <p>Case presentation</p> <p>We report the case of a 69-year-old woman, in whom caseous calcification of the mitral annulus was found at transthoracic echocardiography. Cardiac surgery was performed because of significant mitral regurgitation and impairment of functional capacity.</p> <p>Conclusion</p> <p>Caseous calcification of the mitral annulus needs to be considered and confirmed by transthoracic echocardiography since there is potential for diagnostic confusion or misdiagnosis. This lesion appears to have a benign prognosis but, when associated with mitral valve dysfunction, cardiac surgery appears to be the best therapeutic option.</p