Labyrinthum capellae. Le "Annotationes in Marcianum" di Giovanni Scoto Eriugena e la fortuna del neoplatonismo cristiano

The labyrinthum Capella quoted in the title (from a Prudentius of Troyes epistle) represents the allegory of the studium of the liberal arts and the looking for knowledge in the early middle age. This is a capital problem in the early Christianity and, in general, for all the western world, concerning the relationship between faith and science. I studied the evolution of this subject from its birth to Carolingian age, focusing on the most relevant figures, for the western Europe, such Saint Augustine (De doctrina christiana), Martianus Capella (De Nuptiis Philologiae et Mercurii) and Iohannes Scotus Eriugena (Annotationes in Marcianum). Clearly it emerges that there were two opposite ways about this relatioship. According to the first, the human being is capable of get a knowledge about God thanks to its own reason and logical thought processes (by the analysis of the nature as a Speculum Dei); on the other way, only the faith and the grace could give the man the possibility to perceive God, and the Bible is the only book men need to know. From late antiquity to Iohannes Scotus times, a few christian and pagan authors fall into line with first position (the neoplatonic one): Saint Augustine (first part of his life, then he retracted some of his views), Martianus, Calcidius and Macrobius. Other philosophers were not neoplatonic bat believed in the power of the studium: Boethius, Cassiodorus, Isidorus of Seville, Hrabanus Maurus and Lupus of Ferriéres. In order to get an idea of this conception, I finally focused the research on Iohannes Scotus Eriugena's Annotationes in Marcianum. I commented Eriugena's work phrase by phrase trying to catch the sense of his words, the reference, philosophical influences, to trace antecedents and its clouts to later middle age and Chartres school. In this scholastic text Eriugena comments the Capella's work and poses again the question of the studium to his students. Iohannes was a magister in schola Palatina during the time of Carl the Bald, he knew Saint Augustine works, and he knew Boethius, Calcidius, Macrobius, Isidorus and Cassiodorus ones too. He translated Pseudo-Dionysius the Areopagite and Maximus the Confessor. He had a neoplatonic view of Christianity and tried to harmonize the impossibility to know God to man's intellectual capability to get a glimpse of God through the study of the nature. According to this point of view, Eriugena's comment of Martianus Capella was no more a secondary work. It gets more and more importance to understand his research and his mystic, and to understand and really grasp the inner sense of his chief work Periphyseon.

Fine tuning of on-growing diets for farmed marine fish species as a key tool to sustain the aquaculture development

The aim of this thesis was to investigate some important key factors able to promote the prospected growth of the aquaculture sector. The limited availability of fishmeal and fish oil led the attention of the aquafeed industry to reduce the dependency on marine raw materials in favor of vegetable ingredients. In Chapter 2, we reported the effects of fishmeal replacement by a mixture of plant proteins in turbot (Psetta maxima L.) juveniles. At the end of the trial, it was found that over the 15% plant protein inclusion can cause stress and exert negative effects on growth performance and welfare. Climate change aroused the attention of the aquafeed industry toward the production of specific diets capable to counteract high temperatures. In Chapter 3, we investigated the most suitable dietary lipid level for gilthead seabream (Sparus aurata L.) reared at Mediterranean summer temperature. In this trial, it was highlighted that 18% dietary lipid allows a protein sparing effect, thus making the farming of this species economically and environmentally more sustainable. The introduction of new farmed fish species makes necessary the development of new species-specific diets. In Chapter 4, we assessed growth response and feed utilization of common sole (Solea solea L.) juveniles fed graded dietary lipid levels. At the end of the trial, it was found that increasing dietary lipids over 8% led to a substantial decline in growth performance and feed utilization indices. In Chapter 5, we investigated the suitability of mussel meal as alternative ingredient in diets for common sole juveniles. Mussel meal proved to be a very effective alternative ingredient for enhancing growth performance, feed palatability and feed utilization in sole irrespectively to the tested inclusion levels. This thesis highlighted the importance of formulating more specific diets in order to support the aquaculture growth in a sustainable way.