Regulatory risk constraints and investment decisions: unintended consequences for the financial system.

This thesis contributes to the extant research on the impact of regulatory constraints on financial markets, by presenting a collection of three intertwined essays. The first essay examines the relation between regulatory constraints on market risk and the fluctuation of the financial market, often depicted in the literature but not empirically proven. I find that market volatility is significantly dependent on (and Granger-caused by) the relative market risk exposure of Italian banks, measured as the ratio of value at risk and banks’ market risk limit. In the second paper, I explore the channel for the results obtained in the first paper. The theoretical framework is based on a risk-constrained mean-variance framework. In such a framework, if the constraint binds, the portion of the portfolio invested in risky assets (alpha) is lower than in the unconstrained scenario, as expected. Furthermore, alpha is inversely related to the relative market risk exposure (as above, given by the ratio between value at risk and market risk limit). Empirical tests confirm that this constrained mean-variance framework is more accurate in forecasting investment behaviour in risky assets of the Italian banks than the ordinary mean-variance framework. In the third essay, I investigate the role of uncertainty, whose relevance has been deeply investigated by several papers. By adding uncertainty to the constrained mean-variance framework built in the previous chapter, I find that an increase in uncertainty determines a decrease of the portion of portfolio invested in risky assets, in line with the literature. I perform empirical tests which confirm the theoretical result, especially in high-volatility periods when constraints bind tighter

Quimiometria: De los algoritmos clásicos a los genéticos

In this paper the fundamentals of Chemometrics are presented, by means of a quick overview of the most relevant techniques for data display, classification, modeling and calibration. Two emerging techniques such as Genetic Algorithms and Artificial Neural Networks will also be presented. Goal of the paper is to make people aware of the great superiority of multivariate analysis over the commonly used univariate approach. Mathematical and algorithmical details are not presented, since the paper is mainly focused on the general problems to which Chemometrics can be successfully applied in the field of Food Chemistry.En este artículo se muestran los aspectos fundamentales de la Quimiometria por medio de una revisión rápida de las técnicas más relevantes para mostrar los datos, modelar y calibrar. Se describen dos técnicas emergentes como los algoritmos genéticos y las redes neuronales. El objetivo del articulo es que la comunidad científica tome conciencia de la gran superioridad del análisis multivariante sobre el análisis univariante. No se describen los detalles matemáticos y algorítmicos porque el articulo está dirigido a problemas genéricos en los que la Quimiometría puede ser aplicada con éxito dentro del campo de la Química Analítica

Knowledge in Context: The Factivity Principle and Its Epistemological Consequences

The traditional analysis of the notion of knowledge seems to neglect that although we gather many of our beliefs under the flag of \u201cknowledge\u201d we do not always employ the same standards to bestow this title to them. The semantic thesis known as epistemic contextualism, instead, clearly vindicates and accounts for this phenomenon concerning our epistemic custom. Unfortunately, however, epistemic contextualism faces a severe objection - known in the philosophical literature as the factivity problem, - that seriously menaces its own survival. This objection, indeed, claims that the contextualist who endorses two well-known epistemological principles that he should not desire to give up (i.e. the factivity principle, according to which knowledge implies truth, and the closure principle, that maintains that knowledge is closed under known logical implication) cannot coherently state his own theory. Here, after an analytical introduction of the contextualist\u2019s thesis, we propose an analysis of the factivity problem by a critical scrutiny of the main strategies proposed to solve the conundrum. We will show that some of these strategies make some interesting moves forward in the unravelling of the puzzle, but that they all achieve a solution to the factivity problem only at that which seem to be high prices for contextualism

Braincase and endocranial anatomy of two thalattosuchian crocodylomorphs and their relevance in understanding their adaptations to the marine environment

Thalattosuchians are a group of Mesozoic crocodylomorphs known from aquatic deposits of the Early Jurassic-Early Cretaceous that comprises two main lineages of almost exclusively marine forms, Teleosauridae and Metriorhynchoidea. Teleosaurids were found in shallow marine, brackish and freshwater deposits, and have been characterized as semiaquatic near-shore forms, whereas metriorhynchids are a lineage of fully pelagic forms, supported by a large set of morphological characters of the skull and postcranial anatomy. Recent contributions on Thalattosuchia have been focused on the study of the endocranial anatomy. This newly available information provides novel evidence to suggest adaptations on the neuroanatomy, senses organs, vasculature, and behavioral evolution of these crocodylomorphs. However, is still not clear if the major morphological differences between teleosaurids and metriorhynchids were also mirrored by changes in the braincase and endocranial anatomy. Based on X-ray CT scanning and digital endocast reconstructions we describe the braincase and endocranial anatomy of two well-preserved specimens of Thalattosuchia, the semiaquatic teleosaurid Steneosaurus bollensis and the pelagic metriorhynchid Cricosaurus araucanensis. We propose that some morphological traits, such as: an enlarged foramen for the internal carotid artery, a carotid foramen ventral to the occipital condyle, a single CN XII foramen, absence of brain flexures, well-developed cephalic vascular system, lack ofsubtympanic foramina and the reduction of the paratympanic sinus system, are distinctive features of Thalattosuchia. It has been previously suggested that the enlarged foramen for the internal carotid artery, the absence of brain flexures, and the hypertrophied cephalic vascular system were synapomorphies of Metriorhynchidae; however, new information revealed that all of these features were already established at the base of Thalattosuchia and might have been exapted later on their evolutionary history. Also, we recognized some differences within Thalattosuchia that previously have not been received attention or even were overlooked (e.g., circular/bilobate trigeminal foramen, single/double CN XII foramen, separation of the cranioquadrate canal from the external otic apertureFacultad de Ciencias Naturales y Muse

Braincase anatomy of araripesuchus gomesii price, 1959 (crocodyliformes, notosuchia) and the evolution of braincase pneumaticity in crocodyliforms

Recent high-resolution CT-scans of the referred specimen of Araripesuchus gomesii (AMNH-FR 24450; housed at the American Museum of Natural History, New york, USA) from the Santana Formation (Albian; NW Brazil) allowed a detailed study of its skull. Given the pristine preservation of the specimen, the delicate structures of its internal anatomy are preserved. Additionally, given the recent increase of CT data on fossil crocodyliforms, we evaluated the distribution and relative development of the braincase pneumaticity in the group. The braincase of A. gomesii is invaded by several pneumatic recesses that are highly interconnected among them, in many cases being separated by thin bony struts. This condition contrasts with that observed in non-crocodyliform crocodylomorphs (e.g., Almadasuchus, Dibothrosuchus), where these cavities are completely surrounded by their respective hosting bones. In particular, the ventral pneumatic (rostral, pre- and postcarotid, and basioccipital) recesses of A. gomesii are fused between them, forming an almost continuous cavity that extends from the rostrum of the basisphenoid to the level of the otic capsule. As in basal crocodyliforms like Protosuchus haughtoni, the eustachian foramina open directly into a large ventral recess and are not extended internally forming bony tubes that divide internally into canals (anterior and posterior communicating canals), as observed in extant crocodylians, thalattosuchians and Rhabdognathus. Posterodorsally, the mastoid antrum is large and is also interconnected with other dorsal pneumatizations of the skull (intertympanic, posterior tympanic and trigeminal recesses) trough large foramina that are bounded by thin struts. Araripesuchus gomesii bears a rare condition among crocodylomorphs as some of its dermal bones (parietal and squamosal) are invaded by pneumatic cavities. These pneumatic recesses can be interpreted as an anterodorsal expansion of the mastoid antrum and intertympanic recess, as the recess on the squamosal is connected with the former and the recess on the parietal is connected with the latter. The parietal pneumatization seems to be an exclusive feature of crocodyliforms, as Protosuchus richardsoni and Campinasuchus dinszi also bear a pneumatic recess in this bone. It is important to mention that neosuchians (including thalattosuchians) lack any parietal recess, which can be interpreted as a secondary reduction in the clade considering the available information. On the other hand, squamosal pneumatizations have only been reported in some notosuchians (e.g., Notosuchus terrestris) and might represent an additional unique feature of the clade, even though it is not present ubiquitously among members of Notosuchia. The presence of additional cavities also shows that the degree of pneumatization was a dynamic feature among crocodyliforms. Finally, our study reports the presence of recesses (e.g., rostral and trigeminal recesses) in crocodyliforms that were previously reported only in non- crocodyliform crocodylomorphs, expanding their distribution in the clade.Fil: Leardi, Juan Martín. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Estudios Andinos "Don Pablo Groeber". Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Estudios Andinos "Don Pablo Groeber"; ArgentinaFil: Pol, Diego. Museo Paleontológico Egidio Feruglio; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Turner, Alan. Stony Brook University ; State University Of New York;Fil: Kelner, Alexander. Universidade Federal Do Rio de Janeiro. Museu Nacional; BrasilXII Congreso de la Asociación Paleontológica ArgentinaBuenos AiresArgentinaAsociación Paleontológica Argentin