Computational modeling of immune system of the fish for a more effective vaccination in aquaculture

1

Dye-Derived Red-Emitting Carbon Dots for Lasing and Solid-State Lighting

Carbon dots are carbon-based nanoparticles renowned for their intense light-emitting capabilities covering the whole visible light range. Achieving carbon dots emitting in the red region with high efficiency is extremely relevant due to their huge potential in biological applications and in optoelectronics. Currently, photoluminescence in such an energy interval is often associated with polyheterocyclic molecular domains forming during the synthesis that, however, present low emission efficiency and issues in controlling the optical features. Here, we overcome these problems by solvothermally synthesizing carbon dots starting from Neutral Red, a common red-emitting dye, as a molecular precursor. As a result of the synthesis, such molecular fluorophore is incorporated into a carbonaceous core while retaining its original optical properties. The obtained nanoparticles are highly luminescent in the red region, with a quantum yield comparable to that of the starting dye. Most importantly, the nanoparticle carbogenic matrix protects the Neutral Red molecules from photobleaching under ultraviolet excitation while preventing aggregation-induced quenching, thus allowing solid-state emission. These advantages have been exploited to develop a fluorescence-based color conversion layer by fabricating polymer-based highly concentrated solid-state carbon dot nanocomposites. Finally, the dye-based carbon dots demonstrate both stable Fabry-Perot lasing and efficient random lasing emission in the red region

Design and Application of New Low-Cost Instruments for Marine Environmental Research

The development of low-cost instrumentation plays a key role in marine environmental studies and represents one of the most innovative aspects of current oceanographic research. These kinds of devices can be used for several applications, ranging from vertical profilers to stand-alone systems, and can be installed on different platforms (buoys, Voluntary Observing Ships, underwater vehicles, etc.). The availability of low-cost technologies enables the realization of extended observatory networks for the study of marine physical and biological processes through an integrated approach merging in situ observations, forecasting models and remotely sensed data. We present new low-cost sensors and probes developed to measure marine temperature, conductivity, chlorophyll a and Chromophoric Dissolved Organic Matter fluorescence, focusing on sensing strategies, general architecture, laboratory trials, in situ tests and comparison with standard instruments. Furthermore, we report the expendable (New T-FLaP), vertical profiler (T-FLaPpro) and stand-alone (Spectra) applications of these technological developments that were tested during several oceanographic surveys in the Mediterranean Sea

Assessment of the Photosynthetic Response of Posidonia oceanica (Linneaus) Delile, 1813 along a Depth Gradient in the Northern Tyrrhenian Sea (Latium, Italy)

Posidonia oceanica (L.) Delile meadows are recognized to be one of the most productive ecosystems of the Mediterranean basin. Due to the impacts of human activities in coastal areas, seagrasses are experiencing a critical decline. In this context, the understanding of the dynamics of production and photosynthesis in response to the environmental factors is essential to address efficient conservation strategies that limit this trend and to assess the ecological status of marine ecosystems. Pulse Amplitude Modulated (PAM) fluorometry has been widely implemented to assess seagrass health and productivity. Here we analyzed the photosynthetic dynamics of P. oceanica according to its bathymetric distribution and daily light availability along a depth gradient to be used as baseline for monitoring purposes on the health status of the seagrass meadows in the Northern Tyrrhenian Sea. Moreover, to investigate the effects of the environmental factors on the health status of P. oceanica within the study area through a multidisciplinary approach, the models contained in the Civitavecchia Coastal Environmental Monitoring System were used. In this study, significant photo-physiological changes have been observed among the investigated meadows. Moreover, the integration of physiological and hydrodynamic information allowed the description of how P. oceanica modulates its photosynthetic capacity at different environmental conditions

Development of a new predictive index (Bathing water quality index, bwqi) based on escherichia coli physiological states for bathing waters monitoring

Bacterial pathogens in coastal aquatic ecosystems pose a potential public health hazard for bathing water use. The European Bathing Water Directive (2006/7/EC) currently relies on the culturability of fecal pollution bacterial indicators such as Escherichia coli, without considering dormant or quiescent (Viable But Not Culturable, VBNC) cells, whose possible resuscitation after bathers ingestion cannot be excluded. Standard methods are also time-consuming and therefore hardly meet early warning needs of marine monitoring. To solve this issue, a new index, the Bathing Water Quality Index (BWQI), has here been developed, allowing to identify the most favorable coastal zones for recreational use. The index was calculated by combining numerical simulations of living and dormant E. coli abundances and their residence times. To specifically set up the model with the different physiological states of the whole E. coli population, an ad hoc experiment based on the fluorescent antibody method was performed. The BWQI application to Santa Marinella bathing area highlights a potential risk for human health in the zone most frequented by bathers. This study provides a predictive tool to support preventive decisions of the competent authorities and to properly protect bathers’ health, stressing the need for improved methods for environmental monitoring