Sonophoresis efficiency: consequences of methyl donors supplementation at early developmental stage in gilthead seabream (Sparus aurata). Effects on growth, nutrient metabolism, egg and larval quality, and methylation patterns of larvae and juvenile fish

Dissertação de mestrado, Aquacultura e Pescas, Faculdade de Ciências e Tecnologia, Universidade do Algarve, 2016It is essential that the vegetable ingredients that will be use in Aquaculture feeds can maintain the growth parameters in fish when compared with the fish meal diets. Studies have shown that the replacement may be achieved until a certain level without affecting the growth parameters. Sometimes the vegetable diets lack essential amino acids that need to be supplemented in the feeds, one of the amino acids that sometimes is lacking is the Methionine. In this study the gilthead seabream (Sparus aurata, L. 1758) eggs were supplemented with Methionine to understand if the supplementation had an effect in the larvae growth. The supplementation was performing using the innovative technique Sonophoresis. The amount of Methionine that entered the supplemented eggs was 33.1- fold higher than in the eggs that were not supplemented. Due to the supplementation the oil globule area of the larvae of the treatment MET was higher in the 2 and 4 days after hatching (DAH), also the dry weight was higher in the larvae of treatment MET during the first week. After the first week the larvae of both treatments presented similar growth parameters so a later supplementation was planned and performed at 57 DAH. This second supplementation was done using a Vegetable feed (VEG) supplemented with methionine. At the end of the experiment the juveniles that were from the eggs supplemented and were fed with VEG diet (METVEG) presented higher condition factor (K). In conclusion the Sonophoresis technique was a success, which allowed the alteration of the composition of the egg with the methionine, the early supplementation was able to promote growth in gilthead seabream larvae. The VEG diet did not negatively affected the survival and promoted fish to achieve similar weight to the FM diet

Taxation: Prepaid Income Deferrals and the “Claim of Right Doctrine”

The effects of wear to friction are studied based on constant-speed friction data collected from dedicated experiments during accelerated wear tests. It is shown how the effects of temperature and load uncertainties produce larger changes to friction than those caused by wear, motivating the consideration of these effects. Based on empirical observations, an extended friction model is proposed to describe the effects of speed, load, temperature and wear. Assuming availability of such model and constant-speed friction data, a maximum likelihood wear estimator is proposed.  A criterion for experiment design is proposed which selects speed points to collect constant-speed friction data which improves the achievable performance bound for any unbiased wear estimator. Practical issues related to experiment length are also considered. The performance of the wear estimator under load and temperature uncertainties is found by means of simulations and verified under three case studies based on real data

New Rotation Sets in a Family of Torus Homeomorphisms

We construct a family $\{\Phi_t\}_{t\in[0,1]}$ of homeomorphisms of the two-torus isotopic to the identity, for which all of the rotation sets $\rho(\Phi_t)$ can be described explicitly. We analyze the bifurcations and typical behavior of rotation sets in the family, providing insight into the general questions of toral rotation set bifurcations and prevalence. We show that there is a full measure subset of $[0,1]$, consisting of infinitely many mutually disjoint non-trivial closed intervals, on each of which the rotation set mode locks to a constant polygon with rational vertices; that the generic rotation set in the Hausdorff topology has infinitely many extreme points, accumulating on a single totally irrational extreme point at which there is a unique supporting line; and that, although $\rho(t)$ varies continuously with $t$, the set of extreme points of $\rho(t)$ does not. The family also provides examples of rotation sets for which an extreme point is not represented by any minimal invariant set, or by any directional ergodic measure.Comment: Author's accepted version. The final publication is available at Springer via http://dx.doi.org/10.1007/s00222-015-0628-