Combining remote sensing analysis with machine learning to evaluate short-term coastal evolution trend in the shoreline of Venice.

With increasing storminess and incessant sea-level rise, coastal erosion is becoming a primary issue along many littorals in the world. To cope with present and future climate change scenarios, it is important to map the shoreline position over years and assess the coastal erosion trends to select the best risk management solutions and guarantee a sustainable management of communities, structures, and ecosystems. However, this objective is particularly challenging on gentle-sloping sandy coasts, where also small sea-level changes trigger significant morphological evolutions. This study presents a multidisciplinary study combining satellite images with Machine Learning and GIS-based spatial tools to analyze short-term shoreline evolution trends and detect erosion hot-spots on the Venice coast over the period 2015-2019. Firstly, advanced image preprocessing, which is not frequently adopted in coastal erosion studies, was performed on satellite images downloaded within the same tidal range. Secondly, different Machine Learning classification methods were tested to accurately define shoreline position by recognizing the land-sea interface in each image. Finally, the application of the Digital Shoreline Analysis System tool was performed to evaluate and visualize coastal changes over the years. Overall, the case study littoral reveals to be stable or mainly subjected to accretion. This is probably due to the high presence of coastal protection structures that stabilize the beaches, enhancing deposition processes. In detail, with respect to the total length of the considered shoreline (about 83 km), 5 % of the coast is eroding, 36 % is stable, 52 % is accreting and 7 % is not evaluable. Despite a significant coastal erosion risk was not recognized within this region, well-delimited erosion hot-spots were mapped in correspondence of Caorle, Jesolo and Cavallino-Treporti municipalities. These areas deserve higher attention for territorial planning and prioritization of adaptation measures, facing climate change scenarios and sea-level rise emergencies in the context of Integrated Coastal Zone Management.

Development of a Multi-Dimensional Coastal Vulnerability Index: Assessing vulnerability to inundation scenarios in the Italian coast.

Understanding how natural and human-induced drivers will contribute to rising vulnerability and risks in coastal areas requires a broader use of future projections capturing the spatio-temporal dynamics which drive changes in the different vulnerability dimensions, including the socio-demographic and economic spheres. To go beyond the traditional approaches for coastal vulnerability appraisal, a Multi-dimensional Coastal Vulnerability Index (MDim-CVI) - integrating a composite set of physical, environmental and socio-economic indicators - is proposed to rank Italian coastal provinces according to their relative vulnerability to extreme sea level scenarios, in 2050. Specifically, information on hazard-prone areas, potentially inundated by sea level rise and extreme water levels (under the RCP8.5 climate scenario) is combined with indicators of geomorphic vulnerability (e.g. elevation, distance from coastline, shoreline evolution trend) exposure, and adaptive capacity (e.g. sensible segments of the population, GDP, land use patterns). The methodology is applied to a reference timeframe, representing current climate and land use condition, and a future scenario for the year 2050, integrating both climate projections and data simulating potential evolution of the environmental and socio-economic systems. Results show that most vulnerable provinces are located in the North Adriatic, the Gargano area and other Southern parts of Italy, mostly due to the very high vulnerability scores reported by climate-related indicators (e.g. extreme sea level). The number of vulnerable provinces as well as the magnitude of vulnerability is expected to increase in the future due to the worsening of climate, environmental, and socio-economic conditions (e.g. land use variations and increase of the elderly population). These outcomes can timely inform integrated coastal zone management and support climate adaptation planning.

Demonstration of a near-IR line-referenced electro-optical laser frequency comb for precision radial velocity measurements in astronomy.

An important technique for discovering and characterizing planets beyond our solar system relies upon measurement of weak Doppler shifts in the spectra of host stars induced by the influence of orbiting planets. A recent advance has been the introduction of optical frequency combs as frequency references. Frequency combs produce a series of equally spaced reference frequencies and they offer extreme accuracy and spectral grasp that can potentially revolutionize exoplanet detection. Here we demonstrate a laser frequency comb using an alternate comb generation method based on electro-optical modulation, with the comb centre wavelength stabilized to a molecular or atomic reference. In contrast to mode-locked combs, the line spacing is readily resolvable using typical astronomical grating spectrographs. Built using commercial off-the-shelf components, the instrument is relatively simple and reliable. Proof of concept experiments operated at near-infrared wavelengths were carried out at the NASA Infrared Telescope Facility and the Keck-II telescope.

The development of a protoplanetary disk from its natal envelope.

Class 0 protostars, the youngest type of young stellar objects, show many signs of rapid development from their initial, spheroidal configurations, and therefore are studied intensively for details of the formation of protoplanetary disks within protostellar envelopes. At millimetre wavelengths, kinematic signatures of collapse have been observed in several such protostars, through observations of molecular lines that probe their outer envelopes. It has been suggested that one or more components of the proto-multiple system NGC 1333-IRAS 4 (refs 1, 2) may display signs of an embedded region that is warmer and denser than the bulk of the envelope. Here we report observations that reveal details of the core on Solar System dimensions. We detect in NGC 1333-IRAS 4B a rich emission spectrum of H2O, at wavelengths 20-37 microm, which indicates an origin in extremely dense, warm gas. We can model the emission as infall from a protostellar envelope onto the surface of a deeply embedded, dense disk, and therefore see the development of a protoplanetary disk. This is the only example of mid-infrared water emission from a sample of 30 class 0 objects, perhaps arising from a favourable orientation; alternatively, this may be an early and short-lived stage in the evolution of a protoplanetary disk.

Evaluation of the genotoxic activity and acute toxicity of Euphorbia splendens latex, a molluscicide for the control of schistosomiasis.

1. The latex of Euphorbia splendens var. hislopii has a molluscicidal action at low concentration (LD90 less than 1.5 ppm or 1.5 micrograms/ml) against the vector snails of schistosomiasis. 2. In the present study, the latex in natura or after lyophilization was submitted to the Ames test and the chromotest to evaluate genotoxicity, to the Microtox System to determine acute toxicity, and to the Chinese hamster ovary cell assay (CHO) to measure cytotoxicity. 3. The latex had no mutagenic activity in the presence or absence of S9 toward the TA98 and TA100 strains of Salmonella typhimurium (Ames test) at concentrations up to 200 microliters/plate (in natura) and of 200 micrograms/plate (lyophilized). The lyophilized latex had no genotoxic activity (Chromotest) and no acute toxic effect on Photobacterium phosphoreum at concentrations up to 445 micrograms/ml, whereas the sample in natura had a toxic effect with an EC50 of 148,000 microliters/l (or ppm). In the CHO/cytotoxicity assay, the lyophilized latex had no cytotoxic effect in quantities up to 200 micrograms. 4. The latex was found to have no acute toxicity or mutagenic activity at the concentrations of 10 to 12 micrograms/ml (or ppm) that are being proposed for molluscicidal use in the field.

Evaluation of the genotoxic activity and acute toxicity of Euphorbia splendens latex, a molluscicide for the control of Schistosomiasis

The latex of euphorbia splendens var. hislopii has a molluscicidal action at low concentration (LD90 less than 1.5 ppm or 1.5 */ml) against the vector snails of schistosomiasis. In the present study, the latex in natura or after lyophilization was submitted to the Ames test and the chromotest to evaluate genotoxicity, to the Microtox System to determine acute toxicity, and to the Chinese hamster ovary cell assay (CHO) to measure cytotoxicity. The latex had no mutagenic activity in the presence or absence of S9 toward the TA98 and TA100 strains of Salmonella typhimurium (Ames test) at concentration up to 200 */plate (in natura) and of 200 *g/plate (lyophilized). The lyophilized latex had no genotoxic activity (Chromotest) and acute toxic effect on Photobacterium phosphoreum at concentrations up to 445 *g/ml, whereas the sample in natura had a toxic effect with an EC50 of 148,000 *l/l (or ppm). In the CHO/cytotoxicity assay, the lyophilized latex had no cytotoxicit effect in quantities up to 200 *g. The latex was found to have no acute toxicity or mutagenic at the concentrations of 10 to 12 *g/ml (or ppm) that are being proposed for molluscicidal use in the field