Subtle reproductive impairment through nitric oxide-mediated mechanisms in sea urchins from an area affected by harmful algal blooms

The health of the sea urchin Paracentrotus lividus, a key species in the Mediterranean Sea, is menaced by several pressures in coastal environments. Here, we aimed at assessing the reproductive ability of apparently healthy P. lividus population in a marine protected area affected by toxic blooms of Ostreospsis cf. ovata. Wide-ranging analyses were performed in animals collected prior to and during the bloom, as well as at several times thereafter, during the reproductive season. Adults showed a low fertilization rate, along with high nitric oxide (NO) levels in the gonads and the nitration of the major yolk protein toposome, which is an important player in sea urchin development. Serious developmental anomalies were observed in the progeny, which persist several months after the bloom. NO levels were high in the different developmental stages, which also showed variations in the transcription of several genes that were found to be directly or indirectly modulated by NO. These results highlight subtle but important reproductive flaws transmitted from the female gonads to the offspring with the NO involvement. Despite a recovery along time after the bloom, insidious damages can be envisaged in the local sea urchin population, with possible reverberation on the whole benthic system

InP/InGaAs photodetector on SOI photonic circuitry

We present an InP-based membrane p-i-n photodetector on a silicon-on-insulator sample containing a Si-wiring photonic circuit that is suitable for use in optical interconnections on Si integrated circuits (ICs). The detector mesa footprint is 50 µm2, which is the smallest reported to date for this kind of device, and the junction capacitance is below 10 fF, which allows for high integration density and low dynamic power consumption. The measured detector responsivity and 3-dB bandwidth are 0.45 A/W and 33 GHz, respectively. The device fabrication is compatible with wafer-scale processing steps, guaranteeing compatibility toward future-generation electronic IC processing

The 2018 GaN Power Electronics Roadmap

Gallium nitride (GaN) is a compound semiconductor that has tremendous potential to facilitate economic growth in a semiconductor industry that is silicon-based and currently faced with diminishing returns of performance versus cost of investment. At a material level, its high electric field strength and electron mobility have already shown tremendous potential for high frequency communications and photonic applications. Advances in growth on commercially viable large area substrates are now at the point where power conversion applications of GaN are at the cusp of commercialisation. The future for building on the work described here in ways driven by specific challenges emerging from entirely new markets and applications is very exciting. This collection of GaN technology developments is therefore not itself a road map but a valuable collection of global state-of-the-art GaN research that will inform the next phase of the technology as market driven requirements evolve. First generation production devices are igniting large new markets and applications that can only be achieved using the advantages of higher speed, low specific resistivity and low saturation switching transistors. Major investments are being made by industrial companies in a wide variety of markets exploring the use of the technology in new circuit topologies, packaging solutions and system architectures that are required to achieve and optimise the system advantages offered by GaN transistors. It is this momentum that will drive priorities for the next stages of device research gathered here

High Yield Production Process for Shigella Outer Membrane Particles

Gram-negative bacteria naturally shed particles that consist of outer membrane lipids, outer membrane proteins, and soluble periplasmic components. These particles have been proposed for use as vaccines but the yield has been problematic. We developed a high yielding production process of genetically derived outer membrane particles from the human pathogen Shigella sonnei. Yields of approximately 100 milligrams of membrane-associated proteins per liter of fermentation were obtained from cultures of S. sonnei ΔtolR ΔgalU at optical densities of 30–45 in a 5 L fermenter. Proteomic analysis of the purified particles showed the preparation to primarily contain predicted outer membrane and periplasmic proteins. These were highly immunogenic in mice. The production of these outer membrane particles from high density cultivation of bacteria supports the feasibility of scaling up this approach as an affordable manufacturing process. Furthermore, we demonstrate the feasibility of using this process with other genetic manipulations e.g. abolition of O antigen synthesis and modification of the lipopolysaccharide structure in order to modify the immunogenicity or reactogenicity of the particles. This work provides the basis for a large scale manufacturing process of Generalized Modules of Membrane Antigens (GMMA) for production of vaccines from Gram-negative bacteria

Developmental endpoints of chronic exposure to suspected endocrine-disrupting chemicals on benthic and hyporheic freshwater copepods

The aims of this study were: (i) to assess if carbamate pesticides and ammonium, widely detected in European freshwater bodies, can be considered ecologically relevant endocrine-disrupting chemicals (EDCs) for benthic and interstitial freshwater copepods; and (ii) to evaluate the potential of copepods as sentinels for monitoring ecosystem health. In order to achieve these objectives, four species belonging to the harpacticoid copepod genus Bryocamptus, namely B. (E.) echinatus, B. (R.) zschokkei, B. (R.) pygmaeus and B. (B.) minutus, were subjected to chronic exposures to Aldicarb and ammonium. A significant deviation from the developmental time of unexposed control cultures was observed for all the species in test cultures. Aldicarb caused an increase in generation time over 80% in both B. minutus and B. zschokkei, but less than 35% in B. pygmaeus and B. echinatus. Ammonium increased generation time over 33% in B. minutus, and 14, 12 and 3.5% for B. pygmaeus, B. zschokkei and B. echinatus, respectively. On the basis of these results it can be concluded that chronic exposure to carbamate pesticides and ammonium alters the post-naupliar development of the test-species and propose their potential role as EDCs, leaving open the basis to search what are the mechanism underlying. A prolonged developmental time would probably produce a detrimental effect on population attributes, such as age structure and population size. These deviations from a pristine population condition may be considered suitable biological indicators of ecosystem stress, particularly useful to compare polluted to unpolluted reference sites. Due to their dominance in both benthic and interstitial habitats, and their sensitivity as test organisms, freshwater benthic and hyporheic copepods can fully be used as sentinel species for assessing health condition of aquatic ecosystems as required by world-wide water legislation.Fil: Di Marzio, Walter Dario. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Castaldo, D.. Universita degli Studi dell'Aquila; ItaliaFil: Di Lorenzo, T.. Istituto per lo Studio degli Ecosistemi; ItaliaFil: Di Cioccio, A.. Universita degli Studi dell'Aquila; ItaliaFil: Sáenz, María Elena. Universidad Nacional de Luján. Departamento de Ciencias Básicas. Programa de Investigación en Ecotoxicología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Galassi, D.. Universita degli Studi dell'Aquila; Itali

Quantitative histopathology of the Mediterranean mussel (Mytilus galloprovincialis L.) exposed to the harmful dinoflagellate Ostreopsis cf. ovata

Ostreopsis cf. ovata is a benthic dinoflagellate that produces palytoxin-like compounds that adversely affect both marine vertebrates and invertebrates and are reported to be responsible for human intoxication in aerosol form. In this work, a histopathological analysis accompanied by quantitative evaluation of tissue injury in mussels (Mytilus galloprovincialis) exposed to O. cf. ovata cells under natural and experimental conditions, provided baseline data on the health status of the mussels in terms of defensive and regressive pathological changes. We recorded a total of 15 health parameters in the digestive system, muscle, kidney and gills in mussels exposed to O. cf. ovata both in the laboratory and at sea. Animals exposed to different concentrations of O. cf. ovata cells (300, 500 and 1000cellsml(-)(1)) for 48h showed activation of the inflammatory response, which increased with the cell concentration, mainly characterized by haemocyte aggregates actively enclosing the algae, while mussel mortality was also recorded in some cases. Moreover the use of image analysis for the evaluation of digestive tubule damage revealed a pronounced increase in the lumen in terms of its area, perimeter and circularity, with a shift in a high percentage of tubules from an adsorbing profile to an atrophic profile. Animals collected from the natural environment during a summer bloom of O. cf. ovata in the Gulf of Naples (Italy) showed comparable lesions in terms of types and severity. This is the first quantitative study assessing damage to the digestive epithelia in terms of lumen modifications in mussels exposed to O. cf. ovata. The presented methodology provides a new technique for automating the evaluation of epithelial tubule modifications. Our results highlight the importance of monitoring the presence of O. cf. ovata in this area, taking into account the effects on the residing marine species