Recreational snorkeling activities to enhance seascape enjoyment and environmental education in the Islas Atlánticas de Galicia National Park (Spain).

Marine ecosystems provide goods and services for human well-being, and many of them correspond to cultural ecosystem services (CES). In Marine Protected Areas (MPAs), recreational activities such as snorkeling have increased recently, taking advantage of CES. However, there is a lack of educational initiatives in temperate areas to promote seascape enjoyment and pro-environmental behavior among these users, in contrast with other coastal areas such as subtropical and Caribbean ones. In this study, we have designed and implemented several snorkeling trails in Cíes Archipelago to address a better usage of CES, in a National Park (NP) context. To assess the seascape in Cíes from the point of view of the marine and sea-watching activities that take place in the NP, a new methodology was designed and implemented, including a pilot experience with snorkelers. This methodology assesses underwater aesthetic values from a multifaceted approach and allows the identification of trail-specific features that should be highlighted for increasing conservation awareness among users through environmental education and interpretation. Also, include the analysis of the users' perception and experience satisfaction, as the factors that may be influencing their pro-environmental behaviors and knowledge. Our results show that snorkeling is a good activity to learn about the seascape values, and the NP could offer it as a guided activity considering some pre and post snorkeling experience requirements.

Flagellin is a Th1 polarizing factor for human CD4+ T cells and induces protection in a murine neonatal vaccination model of rotavirus infection.

Neonates have an increased susceptibility to infections, particularly those caused by intracellular pathogens, leading to high morbidity and mortality rates. This is partly because of a poor response of neonatal CD4+ T cells, leading to deficient antibody production and a low production of IFN-γ, resulting in deficient elimination of intracellular pathogens. The poor memory response of human neonates has underpinned the need for improving vaccine formulations. Molecular adjuvants that improve the response of neonatal lymphocytes, such as the ligands of toll-like receptors (TLRs), are attractive candidates. Among them, flagellin, the TLR5 ligand, is effective at very low doses; prior immunity to flagellin does not impair its adjuvant activity. Human CD4+ and CD8+ T cells express TLR5. We found that flagellin induces the expression of IFN-γ, IL-1ß and IL-12 in mononuclear cells from human neonate and adult donors. When human naïve CD4+ T cells were activated in the presence of flagellin, there was high level of expression of IFN-γ in both neonates and adults. Furthermore, flagellin induced IFN-γ production in Th1 cells obtained from adult donors; in the Th2 population, it inhibited IL-4 cytokine production. Flagellin also promoted expression of the IFN-γ receptor in naive CD4+ T cells from neonates and adults. To test the adjuvant capacity of flagellin in vivo, we used a murine neonate vaccination model for infection with rotavirus, a pathogen responsible for severe diarrhea in young infants. Using the conserved VP6 antigen, we observed an 80% protection against rotavirus infection in the presence of flagellin, but only in those mice previously primed in the neonatal period. Our data suggest that flagellin could be an attractive adjuvant for achieving a Th1 response.

Protamine-based nanoparticles as new antigen delivery systems.

The use of biodegradable nanoparticles as antigen delivery vehicles is an attractive approach to overcome the problems associated with the use of Alum-based classical adjuvants. Herein we report, the design and development of protamine-based nanoparticles as novel antigen delivery systems, using recombinant hepatitis B surface antigen as a model viral antigen. The nanoparticles, composed of protamine and a polysaccharide (hyaluronic acid or alginate), were obtained using a mild ionic cross-linking technique. The size and surface charge of the nanoparticles could be modulated by adjusting the ratio of the components. Prototypes with optimal physicochemical characteristics and satisfactory colloidal stability were selected for the assessment of their antigen loading capacity, antigen stability during storage and in vitro and in vivo proof-of-concept studies. In vitro studies showed that antigen-loaded nanoparticles induced the secretion of cytokines by macrophages more efficiently than the antigen in solution, thus indicating a potential adjuvant effect of the nanoparticles. Finally, in vivo studies showed the capacity of these systems to trigger efficient immune responses against the hepatitis B antigen following intramuscular administration, suggesting the potential interest of protamine-polysaccharide nanoparticles as antigen delivery systems.

Biocompatibility of a self-assembled glycol chitosan nanogel.

The research of chitosan-based nanogel for biomedical applications has grown exponentially in the last years; however, its biocompatibility is still insufficiently reported. Hence, the present work provides a thorough study of the biocompatibility of a glycol chitosan (GC) nanogel. The obtained results showed that GC nanogel induced slight decrease on metabolic activity of RAW, 3T3 and HMEC cell cultures, although no effect on cell membrane integrity was verified. The nanogel does not promote cell death by apoptosis and/or necrosis, exception made for the HMEC cell line challenged with the higher GC nanogel concentration. Cell cycle arrest on G1 phase was observed only in the case of RAW cells. Remarkably, the nanogel is poorly internalized by bone marrow derived macrophages and does not trigger the activation of the complement system. GC nanogel blood compatibility was confirmed through haemolysis and whole blood clotting time assays. Overall, the results demonstrated the safety of the use of the GC nanogel as drug delivery system.

Conformational changes in human plasma proteins induced by metal oxide nanoparticles.

The interaction of nanoparticles (Nps) with body fluids may induce conformational changes in the proteins present in the medium. Such interactions could induce functional loss or important modifications in some proteins, and trigger cellular events induced by the Np-protein moiety. As metal oxide nanoparticles are widely used for various applications, the interaction of four different metal oxide Nps (ZnO, TiO2, CeO2 and Al2O3) with three of the main protein fractions from human plasma (albumin, fibrinogen and globulins) was characterized by fluorescence and Fourier-transform infrared (FTIR) spectroscopy. The pattern of Np-protein interaction was shown to vary depending on the type of Np. For ZnO Nps, a strong interaction was observed, which induced a decrease in the thermal stability of both fibrinogen and albumin at a low temperature, interfering with the clotting activity of fibrinogen. TiO2 and CeO2 Nps showed lower effects, while for Al2O3 Nps only a slight or null interaction was observed at physiological pH. Moreover, the influence of pH was characterized for albumin, showing that the Np-protein interaction has an important dependence on the Np surface charge. The conformational changes induced by metal oxide Nps in the secondary structure of albumin are principally the transformation of α-helices into ß-sheet structures. The interaction, with the exception of Al2O3 nanoparticles at basic pH, could take place in the domain II of the protein, formed mainly by hydrophobic and positive residues.

Effects of in vivo treatment with the dopamine antagonist pimozide and gonadotropin-releasing hormone agonist (GnRHa) on the reproductive axis of Senegalese sole (Solea senegalensis).

The Senegalese sole (Solea senegalensis) is a flatfish that exhibits severe reproductive dysfunctions in captivity. This study aimed at investigating the existence of a dopamine (DA) inhibitory tone on the reproductive axis of this species. Four groups of Senegalese sole breeders were treated with, saline (controls, CNT), the DA antagonist pimozide (PIM, 5 mg kg(-1)), gonadotropin-releasing hormone agonist (GnRHa, 40 µg kg(-1)) or a combination of PIM+GnRHa (COMB). Effects were evaluated on pituitary GnRH levels (ELISA), pituitary gonadotropin subunit transcript levels (qPCR), plasma levels of sex steroids and vitellogenin (ELISA), gonad development (histology), spermiation and egg production. The GnRHa treatment induced egg release and stimulated testis maturation. In males, PIM did not affect pituitary GnRH content, but enhanced GnRHa-induced pituitary GPα transcripts and modified plasma androgen levels; moreover, PIM stimulated spermatogenesis and milt production, both alone and combined with GnRHa. In females, PIM did not affect pituitary and plasma endocrine parameters and did not affect egg production and fertilization success of the broodstock, either alone or in the combined treatment. In conclusion, data indicated the existence of a DA inhibition in mature males, which would be absent or weakly expressed in females.

Effects of carbohydrate sources on growth, body composition and tissue lipid deposition of blackspot seabream, Pagellus bogaraveo (Brunnich).

Rearing blackspot seabream has been associated with low growth rates and excessive lipid accumulation, resulting in a reduction of the edible yield. The effect of extruded diets containing different carbohydrate sources (wheat vs. wheat bran) was evaluated on 100 g blackspot seabream growth performance, feed utilization and fat deposition, taking into consideration the optimal dietary protein and lipid level described for smaller-sized fish. A fish meal-based diet was also tested as a control to assure maximal growth rates were achieved. The experiment was held in sea cages at environmental conditions. Duplicate groups of fish were distributed among six cages with a stocking density of 1.3 kg/m(3) and hand-fed each diet for 7 months. At the end of the experiment, fish in all groups doubled their body weight attaining 190-230 g. Specific growth rate (0.3-04), feed conversion ratio (1.3-1.6) and protein gain (0.5-0.6 g/kg/day) were similar among treatments. The Hepatosomatic Index, the Viscerosomatic Index and final whole body composition did not vary significantly among dietary treatments; nevertheless, the inclusion of wheat bran induced a significant increase of liver lipid content and the highest mesenteric fat index. All diets were effective in reducing whole body and mesenteric fat compared with initial values.