Engineering muscle networks in 3D gelatin methacryloyl hydrogels: influence of mechanical stiffness and geometrical confinement

In this work, the influence of mechanical stiffness and geometrical confinement on the 3D culture of myoblast-laden gelatin methacryloyl (GelMA) photo-crosslinkable hydrogels was evaluated in terms of in vitro myogenesis. We formulated a set of cell-laden GelMA hydrogels with a compressive modulus in the range 1÷17 kPa, obtained by varying GelMA concentration and degree of cross-linking. C2C12 myoblasts were chosen as the cell model, to investigate the supportiveness of different GelMA hydrogels on myotube formation up to 2 weeks. Results showed that the hydrogels with a stiffness in the range 1÷3 kPa provided enhanced support to C2C12 differentiation in terms of myotube number, rate of formation and space distribution. Finally, we studied the influence of geometrical confinement on myotube orientation by confining cells within thin hydrogel slabs having different cross-sections: i) 2000×2000 m, ii) 1000×1000 m and iii) 500×500 m. The obtained results showed that by reducing the cross-section—i.e., by increasing the level of confinement—myotubes were more likely restrained and formed aligned myostructures that better mimicked the native morphology of skeletal muscle

Similarity Measures and Dimensionality Reduction Techniques for Time Series Data Mining

The chapter is organized as follows. Section 2 will introduce the similarity matching problem on time series. We will note the importance of the use of efficient data structures to perform search, and the choice of an adequate distance measure. Section 3 will show some of the most used distance measure for time series data mining. Section 4 will review the above mentioned dimensionality reduction techniques

Thermal imaging of Erta 'Ale active lava lake (Ethiopia)

Active lava lakes represent the uppermost portion of a volume of convective magma exposed to the atmosphere, and provide open windows on magma dynamics within shallow reservoirs. Erta 'Ale volcano located within the Danakil Depression in Ethiopia, hosts one of the few permanent convecting lava lakes, active at least since the last century. We report here the main features of Erta 'Ale lake surface investigated using a handheld infrared thermal camera between 11 and 12 November 2006. In both days, the lake surface was mainly characterized by efficient magma circulation reflecting in the formation of well-marked incandescent cracks and wide crust plates. These crossed the lake from the upwelling to the downwelling margin with mean speeds ranging between 0.01 and 0.15 m s-1. Hot spots opened eventually in the middle of crust plates and/or along cracks. These produced explosive activity lasting commonly between ~10 and 200 s. Apparent temperatures at cracks ranged between ~700 and 1070˚C, and between ~300 and 500˚C at crust plates. Radiative power output of the lake varied between ~45 and 76 MW according to the superficial activity and continuous resurfacing of the lake. Time series analysis of the radiant power output data reveals cyclicity with a period of ~10 min. The combination of visual and thermal observations with apparent mean temperatures and convection rates allows us to interpret these signals as the periodic release of hot overpressured gas bubbles at the lake surface

Is aortic wall degeneration related to bicuspid aortic valve anatomy in patients with valvular disease?

ObjectivePatients with bicuspid aortic valve are at increased risk for aortic complications.MethodsA total of 115 consecutive patients with bicuspid aortic valve disease underwent surgery of the ascending aorta. We classified the cusp configuration by 3 types: fusion of left coronary and right coronary cusps (type A), fusion of right coronary and noncoronary cusps (type B), and fusion of left coronary and noncoronary cusps (type C). Histopathologic changes in the ascending aortic wall were graded (aortic wall score).ResultsWe observed type A fusion in 85 patients (73.9%), type B fusion in 28 patients (24.3%), and type C fusion in 2 patients (1.8%). Patients with type A fusion were younger at operation than patients with type B fusion (51.3 ± 15.5 years vs 58.7 ± 7.6 years, respectively; P = .034). The mean ascending aorta diameter was 48.9 ± 5.0 mm and 48.7 ± 5.7 mm in type A and type B fusion groups, respectively (P = .34). The mean aortic root diameter was significantly larger in type A fusion (4.9 ± 6.7 mm vs 32.7 ± 2.8 mm; P < .0001). The aortic wall score was significantly higher in type A fusion than in type B fusion (P = .02). The prevalence of aortic wall histopathologic changes was significantly higher in type A fusion. Moreover, there were no statistically significant differences between type A and type B fusion in terms of prevalence of bicuspid aortic valve stenosis, regurgitation, or mixed disease.ConclusionIn diseased bicuspid aortic valves, there was a statistically significant association between type A valve anatomy and a more severe degree of wall degeneration in the ascending aorta and dilatation of the aortic root at younger age compared with type B valve anatomy

Seismic Hazard Mapping inside the Project SIGMA

The Project SIGMA (Sistema Integrato di sensori in ambiente cloud per la Gestione Multirischio Avanzata) arises from the fields of Information and Communications Technologies (ICT) and advanced applications for the control, monitoring and management of high-risk processes of natural and social origin. SIGMA is a multilevel architecture whose main aim is the acquisition, integration and processing of heterogeneous data from different sources (seismic, volcanic, meteorologic, hydric, pluvial, car traffic, marine traffic, and so on) to manage and elaborate risk mitigation strategies which are important for the emergency management planning. Within the several experimental activities included in the project, there is the designing and realization of a prototype of application platform specialized to provide the operating procedures and software to the public administrations and the industrial companies, for constantly monitoring both the anthropic and natural phenomena in Sicily. In this framework, of course, the seismic risk analysis plays a very important role since Sicily is one of the Italian regions with high seismic risk. Seismic risk assessment may be approached in two different ways: i) as average seismic risk of the buildings and facilities in question during the period considered, combining the vulnerability of different building types and the seismic hazard for the site, which are then expressed in terms of the effects of the events derived from an earthquake catalogue that exceed a specified threshold during a given period; ii) as estimated damage of the buildings and the critical facilities using a scenario input described in terms of the source parameters of the hypocenter as location, magnitude, and so on. Here we deal with the hazard calculation through the code CRISIS (Ordaz, Aguilar and Arboleda) and with the code PROSCEN (PRObabilistic SCENario, [Rotondi and Zonno, 2010]) to obtain earthquake scenario to be used in the latter approach. Indeed, an earthquake scenario is a planning tool that helps decision makers to visualize the specific impact of an earthquake based on the scientific knowledge. An earthquake scenario creates a picture that the members of community can recognize and, at the same time, improves the communication between the scientific, emergency management and policy communities to seismic risk reduction

THERMAL IMAGING OF ERTA 'ALE LAVA LAKE

The project ''Sviluppo di sistemi di monitoraggio'' (Dipartimento di Protezione Civile di Regione Sicilia, INGV Catania Section, Italy), the Leverhulme Trust, the BBC, and the Ethiopian Air Force

Measurement of Sea Waves

Sea waves constitute a natural phenomenon with a great impact on human activities, and their monitoring is essential for meteorology, coastal safety, navigation, and renewable energy from the sea. Therefore, the main measurement techniques for their monitoring are here reviewed, including buoys, satellite observation, coastal radars, shipboard observation, and microseism analysis. For each technique, the measurement principle is briefly recalled, the degree of development is outlined, and trends are prospected. The complementarity of such techniques is also highlighted, and the need for further integration in local and global networks is stressed

Infrasonic Gliding Reflects a Rising Magma Column at Mount Etna (Italy)

Infrasound is increasing applied as a tool to investigate magma dynamics at active volcanoes, especially at open-vent volcanoes, such as Mt. Etna (Italy), which are prodigious sources of infrasound. Harmonic infrasound signals have been used to constrain crater dimensions and track the movement of magma within the shallow plumbing system. This study interprets the remarkable systematic change in monotonic infrasound signals preceding a lava fountaining episode at Mt. Etna on 20 February 2021. We model the changing tones (0.7 to 3 Hz fundamental frequency) as a rise in the magma column from 172 ± 25 m below the crater rim to 78 ± 8 m over the course of 24 h. The infrasonic gliding disappears approximately 4 h before the onset of lava fountaining as the magma column approaches the flare of the crater and acoustic resonance is no longer supported. The featured 20 February event was just one of 52 lava fountain episodes that occurred at Mt. Etna over the course of 9 months in 2021 and was the only lava fountain episode where dramatic gliding was observed as a subsequent partial collapse of the crater prevented future resonance. The results presented here demonstrate that analysis of infrasonic gliding can be used to track the position of the magma free surface and hence may provide information on the processes taking place within the plumbing system before eruptive activity