Repeated (4D) marine geophysical surveys as a tool for studying the coastal environment and ground-truthing remote-sensing observations and modeling

Sandy beaches and the nearshore environment are dynamic coastal systems characterized by sediment mobilization driven by alternating stormy and mild wave conditions. However, this natural behavior of beaches can be altered by coastal defense structures. Repeated surveys carried out with autonomous surface vehicles (ASVs) may represent an interesting tool for studying nearshore dynamics and testing the effects of mitigation strategies against erosion. We present a one-year experiment involving repeated stratigraphic and morpho-bathymetric surveys of a nearshore environment prone to coastal erosion along the Emilia-Romagna coast (NE Italy), the Lido di Dante beach, carried out between October 2020 and December 2021 using an ASV. Seafloor and subseafloor “snapshots” collected at different time intervals enabled us to delineate the seasonal variability and shed light on key controlling variables, which could be used to integrate and calibrate remote-sensing observations and modeling. The results demonstrated that repeated surveys could be successfully employed for monitoring coastal areas and represent a promising tool for studying coastal dynamics on a medium/short (years/months) timescale

Focal-Plane Change Triggered Video Compression for Low-Power Vision Sensor Systems

Video sensors with embedded compression offer significant energy savings in transmission but incur energy losses in the complexity of the encoder. Energy efficient video compression architectures for CMOS image sensors with focal-plane change detection are presented and analyzed. The compression architectures use pixel-level computational circuits to minimize energy usage by selectively processing only pixels which generate significant temporal intensity changes. Using the temporal intensity change detection to gate the operation of a differential DCT based encoder achieves nearly identical image quality to traditional systems (4dB decrease in PSNR) while reducing the amount of data that is processed by 67% and reducing overall power consumption reduction of 51%. These typical energy savings, resulting from the sparsity of motion activity in the visual scene, demonstrate the utility of focal-plane change triggered compression to surveillance vision systems

Biological soil crusts of Arctic Svalbard and of Livingston Island, Antarctica

Biological soil crusts (BSCs) occur in arid and semi-arid regions worldwide including the Polar Regions. They are important ecosystem engineers, and their composition and areal coverage should be understood before assessing key current functional questions such as their role in biogeochemical nutrient cycles and possible climate change scenarios. Our aim was to investigate the variability of BSCs from Arctic Svalbard and the Antarctic Island, Livingston, using vegetation surveys based on classification by functional group. An additional aim was to describe the structure of BSCs and represent a classification system that can be used in future studies to provide a fast and efficient way to define vegetation type and areal coverage. Firstly, this study demonstrates huge areas occupied by BSCs in Arctic Svalbard, with up to 90 % of soil surface covered, dominated by bryophytes and cyanobacteria, and showing an unexpectedly high variability in many areas. Livingston Island has lower percentage coverage, up to 55 %, but is dominated by lichens. Our findings show that both Polar Regions have varied BSC coverage, within the sites and between them, especially considering their harsh climates and latitudinal positions. Secondly, we have classified the BSCs of both areas into a system that describes the dominant functional groups and local geography, creating a simple scheme that allows easy identification of the prevailing vegetation type. Our results represent the first contribution to the description of BSCs based on their functional group composition in Polar Regions

An articulatory silicon vocal tract for speech and hearing prostheses

10.1109/TBCAS.2011.2159858IEEE Transactions on Biomedical Circuits and Systems54339-34

Ultra-low-power electronics for non-invasive medical monitoring

New electronics for non-invasive medical monitoring promise low-cost, maintenance-free, and lightweight devices. These devices are critical in long-term medical measurements and in home-based tele-monitoring services, which are extremely important for the reduction of health care costs. Here, we present several methods for reducing power consumption while retaining precision. In particular, we focus on the monitoring of the heart-because of its importance-and we describe a micropower electrocardiograph, an ultra-low-power pulse oximeter, an ultra-low-power phonocardiograph, an integrated-circuit switched-capacitor model of the heart, and a low-power RF-antenna-powered CMOS rectifier for energy harvesting. We also introduce an ultra-low-power platform for medical monitoring that enables the integration of monitoring circuitry in a wireless, low-cost, and battery-free device, and describe a method for audio localization of the device in case of a medical alarm

A spatially explicit food web model for supporting the management of a marine Natura 2000 site: ongoing efforts at the Tegnùe di Chioggia

As remarked by the recent European legislation (MSPD), plans managing the interaction between conservation goals and maritime uses should consider the spatial dimension, to be effective and easily applied. In such a context, food web modelling, considering both the structure and functioning of an ecosystem, is increasingly perceived as an important resource informing sea planning, at the different spatial scales. In this preliminary work, an existing food web model (based on Ecopath with Ecosim) of the northern Adriatic Sea was spatialized and downscaled to the ‘Tegnùe di Chioggia’, for testing different management measures. This area, characterised by the presence of biogenic rocky outcrops and proposed as Site of Community Importance in 2011, is indeed still missing of a management plan. Trophic groups of high naturalistic and socio-economic interest have been distributed by considering different habitats and tolerance to environmental drivers. In the model, four main habitats have been defined (rocky habitat simulating the tegnùe, sandy and muddy habitats and mussel farms) and the trophic groups assigned to each one according to their preferences. Fishing activities are described considering 5 different fleets (including different trawling gears, hydraulic dredge, artisanal and recreational fishery) and their fishing effort have been spatialized based on AIS data. The tool provides output maps of group biomasses, catches, and ecosystem functioning indicators. Preliminary results are discussed in relation to their potential use for comparing the consequences of different management options (for instance the expansion of the current SCI, partial artisanal/recreational fishing openings within the SCI area, and expansion/reallocation of mussel farms and clam fishing areas)

Application of spatial food web simulations at a marine Natura 2000 site: analysis of vulnerability and management actions

Marine Natura 2000 sites play an important role in nature conservation, while representing an opportunity to promote sustainable natural resources exploitation. To be effective, Natura 2000 sites should be managed considering spatial and temporal ecosystem dynamics. In this study, conducted within the Interreg project CASCADE, we applied a spatially explicit food web model in Ecopath with Ecosim to the Tegnùe di Chioggia SCI, a Natura 2000 site characterized by biogenic rocky outcrops and still lacking a proper management plan. Following the principles of the Ecosystem Approach, biological and economic compartments were included in the model. Species groups distribution and spatial dynamics of main fishing fleets were considered. Through temporal simulations, we first assessed the vulnerability of the socio-ecological system to climate change and fishing effort scenarios. Spatial simulations and multi-criteria analysis were combined, to compare the effects of alternative management actions on the ecosystem (artisanal fishing in the SCI, SCI area extension and mussel farms expansion). Ecosystem indicators were used to summarize simulations outputs. Results confirm the expected vulnerability to climate change: increased water temperature induces a reduction in biomass diversity (lower Kempton index) and commercial species abundance, while species associated to rocky outcrops (e.g., Diplodus annularis) are predicted to decrease substantially. Results indicated that bycatch threats trophic groups when fishing effort is increased over time. Spatial food web simulations also reveal how ecosystem complexity can lead to unexpected results when different management options are compared. Indeed, based on the multi-criteria analysis, the expansion of mussel farming areas was the best management scenario, partly explained by the collateral no-take zone effect for trawlers. Constraints on model performances imposed by data availability, and future monitoring efforts to fill these gaps, are discussed