Dietary supplementation of heat-treated Gracilaria and Ulva seaweeds enhanced acute hypoxia tolerance in gilthead sea bream (Sparus aurata)

Intensive aquaculture practices involve rearing fish at high densities. In these conditions, fish may be exposed to suboptimal dissolved O2 levels with an increased formation of reactive O2 species (ROS) in tissues. Seaweeds (SW) contain biologically active substances with efficient antioxidant capacities. This study evaluated the effects of dietary supplementation of heat-treated SW (5% Gracilaria vermiculophylla or 5% Ulva lactuca) on stress bioindicators in sea bream subjected to a hypoxic challenge. 168 fish (104.5 g average weight) were distributed in 24 tanks, in which eight tanks were fed one of three experimental diets for 34 days: (i) a control diet without SW supplementation, (ii) a control diet supplemented with Ulva, or (iii) a control diet with Gracilaria. Thereafter, fish from 12 tanks (n=4 tanks/dietary treatment) were subjected to 24 h hypoxia (1.3 mg O2 l-1) and subsequent recovery normoxia (8.6 mg O2 l-1). Hypoxic fish showed an increase in hematocrit values regardless of dietary treatment. Dietary modulation of the O2-carrying capacity was conspicuous during recovery, as fish fed SW supplemented diets displayed significantly higher haemoglobin concentration than fish fed the control diet. After the challenge, survival rates in both groups of fish fed SW were higher, which was consistent with a decrease in hepatic lipid peroxidation in these groups. Furthermore, the hepatic antioxidant enzyme activities were modulated differently by changes in environmental O2 condition, particularly in sea bream fed the Gracilaria diet. After being subjected to hypoxia, the gene expression of antioxidant enzymes and molecular chaperones in liver and heart were down regulated in sea bream fed SW diets. This study suggests that the antioxidant properties of heat-treated SW may have a protective role against oxidative stress. The nature of these compounds and possible mechanisms implied are currently being investigated.Fil: Magnoni, Leonardo Julián. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús). Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas. Instituto de Investigaciones Biotecnológicas "Dr. Raúl Alfonsín" (sede Chascomús); Argentina. Universidad de Porto; PortugalFil: Martos Sitcha, Juan Antonio. Consejo Superior de Investigaciones Científicas; EspañaFil: Queiroz, Augusto. Universidad de Porto; PortugalFil: Calduch Giner, Josep Alvar. Consejo Superior de Investigaciones Científicas; EspañaFil: Magalhaes Gonçalves, Jose Fernando. Universidad de Porto; PortugalFil: Rocha, Cristina M.R.. Universidad de Porto; PortugalFil: Abreu, Helena T.. ALGAplus; PortugalFil: Schrama, Johan W.. Wageningen University; Países BajosFil: Ozorio, Rodrigo O.A.. Universidad de Porto; PortugalFil: Perez Sanchez, Jaume. Consejo Superior de Investigaciones Científicas; Españ

Underlying molecular mechanism in the modulation of the ram sperm acrosome reaction by progesterone and 17ß-estradiol

Steroid hormones progesterone (P4) and 17ß-estradiol (E2) not only have important functions in regulation of reproductive processes in mammals but also have direct effects on spermatozoa. There can be induction of the acrosome reaction in ram spermatozoa by P4 and E2 and, in the present study, there was further investigation of mechanisms underlying this effect. In a medium containing agents that increase cAMP, the presence of both P4 and E2 led to changes in the localization of proteins phosphorylated in tyrosine residues evaluated by indirect immunofluorescence. The inclusion of P4 at 1 µM in the media induced an increase in Ca2+i and mobilization in the area of the acrosome (Fluo-4 and Rhod-5 staining, respectively), an increase in ROS (H2DCFDA staining) and a substantial disruption of the acrosome (evaluated using RCA), while E2 did not have these effects. There were no effects on cAMP concentrations or PKA activity with inclusion of these hormones in the media. The inclusion of P4 at 100 pM in the media led to changes in values for sperm kinematic variables which could indicate there was an inhibition of the hyperactivation caused by agents that induce an increase in cAMP concentrations. In conclusion, results from the present study indicate that P4 and E2 promote mechanisms regulating the acrosome reaction in ram spermatozoa, however, these effects on mechanisms are different for the two hormones, and for E2, require further clarification

Statistical Mechanics of Soft Margin Classifiers

We study the typical learning properties of the recently introduced Soft Margin Classifiers (SMCs), learning realizable and unrealizable tasks, with the tools of Statistical Mechanics. We derive analytically the behaviour of the learning curves in the regime of very large training sets. We obtain exponential and power laws for the decay of the generalization error towards the asymptotic value, depending on the task and on general characteristics of the distribution of stabilities of the patterns to be learned. The optimal learning curves of the SMCs, which give the minimal generalization error, are obtained by tuning the coefficient controlling the trade-off between the error and the regularization terms in the cost function. If the task is realizable by the SMC, the optimal performance is better than that of a hard margin Support Vector Machine and is very close to that of a Bayesian classifier.Comment: 26 pages, 12 figures, submitted to Physical Review

Cultivation of Pleurotus mushrooms in substrates obtained by short composting and steam pasteurization

This paper presents results of two experiments for cultivation of Pleurotus ostreatus, Pleurotus pulmonarius and Pleurotus eryngii grown with different formulations of grass and straw mixtures derived from agro-industrial residues. Cultivation was prepared through a number of approaches, such as short composting/pasteurization and axenic culture. In the first experiment, P. pulmonarius was grown on two formulations of different grasses, with no significant differences observed for either productivity or biological efficiency, with values close to 20 and 60%, respectively. The second experiment revealed similar productivity and biological efficiency between P. pulmonarius and P. ostreatus for both forms of substrate treatment (short composting/pasteurization vs. axenic culture), with similar values to those observed in the first experiment. P. eryngii did not produce mushrooms in the composting treatment and showed lower productivity (17.5%) than the other two species (20.5 and 20.8%, respectively) when the substrates were autoclaved (axenic culture). The preparation for short composting and steam pasteurization was described in illustrative figures in order to provide expertise to small producers who wish to initiate economic and sustainable mushroom cultivation making use of regional lignocellulosic residues.Keywords: Steam pasteurization, lignocellulosic biomass, straw mixtures, mushroom

RhIGF-1 treatment increases bone mineral density and trabecular bone structure in children with PAPP-A2 deficiency

KARGER: "This is the peer-reviewed but unedited manuscript version of the following article: Hormone Research in Paediatrics 89.3 (2018): 200-204 DOI: 10.1159/000486336. The final, published version is available at http://www.karger.com/. http://doi.org/10.1159/000486336]."Aim: Our objective was to determine changes in bone mineral density (BMD), trabecular bone score (TBS), and body composition after 2 years of therapy with recombinant human insulin-like growth factor-1 (rhIGF-1) in 2 prepubertal children with a complete lack of circulating PAPP-A2 due to a homozygous mutation in PAPP-A2 (p.D643fs25∗) resulting in a premature stop codon. Methods: Body composition, BMD, and bone structure were determined by dual-energy X-ray absorptiometry at baseline and after 1 and 2 years of rhIGF-1 treatment. Results: Height increased from 132 to 145.5 cm (patient 1) and from 111.5 to 124.5 cm (patient 2). Bone mineral content increased from 933.40 to 1,057.97 and 1,152.77 g in patient 1, and from 696.12 to 773.26 and 911.51 g in patient 2, after 1 and 2 years, respectively. Whole-body BMD also increased after 2 years of rhIGF-1 from baseline 0.788 to 0.869 g/cm2in patient 1 and from 0.763 to 0.829 g/cm2in patient 2. After 2 years of treatment, both children had an improvement in TBS. During therapy, a slight increase in body fat mass was seen, with a concomitant increase in lean mass. No adverse effects were reported. Conclusion: Two years of rhIGF-1 improved growth, with a tendency to improve bone mass and bone microstructure and to modulate body composition.The authors are funded by Fondos de Investigación Sanitaria and FEDER (Grants PI1302195 and PI1600485 to J.A.), Ministerio de Ciencia e Innovación (BFU2014-51836-C2-2-R to J.A.C.), Centro de Investigación Biomédica en Red Fisiopatología de Obesidad y Nutrición (CIBEROBN), Instituto de Salud Carlos III (J.A.), and Fundación Endocrinología y Nutrició