On certain geometric aspects of portfolio optimisation with higher moments

We discuss geometric properties related to the minimisation of a portfolio kurtosis given its first two odd moments, considering a risk-less asset and allowing for short sales. The findings are generalised for the minimisation of any given even portfolio moment with fixed excess return and skewness, and then for the case in which only excess return is constrained. An example with two risky assets provides a better insight on the problems related to the solutions. The importance of the geometric properties and their use in the higher moments portfolio choice context is highlighted.

Inflation targeting, credibility and coordination aspects

There are plenty of economic studies pointing out some requirements, like the inexistence of fiscal dominance, for inflation targeting framework be implemented in successful (credible) way. Essays on how public targets could be used in the absence of such requirements are unusual. In this papel' we appraise how central banks could use inflation targeting before soundness economic fundamentaIs have been achieved. First, based on concise framework, where confidence crises and imperfect information are neglected, we conclude that less ambitious (greater) target for inflation increases the credibility in the precommitment. Optimal target is higher than the one obtained using the Cukierman-Liviatan [7] model, where increasing credibility effect is not considered. Second, extending the model to make confidence crises possible, multiple equilibria solutions becomes possible too. In this case, to set greater targets for inflation may stimulate confidence crises and reduce the policymaker credibility. On the other hand, multiple (bad) equilibria may be avoided. The optimal target depends on the likelihood of each equilibrium be selected. Finally, when perturbing common knowledge uniqueness is restored even considering confidence crises, as in Morris-Shin[ 14]. The first result, i.e. less ambitious target for inflation increases credibility in precommitment, is also recovered. Adding a precise public signal, cOOl'dinated self-fulfilling actions and equilibrium multiplicity may still exist for some lack of common knowledge (as in Angeleto and Weming[l]). In this case, to set greater targets for inflation may stimulate confidence crisis again, reducing the policymaker credibility. From another aspect, multiple (bad) equilibria may be avoided. Optimal policy prescriptions depend on the likelihood of each equilibrium be selected. Results also indicate that more precise public information may open the door for bad equilibrium, contrary to the conventional wisdom that more central oank transparency is always good when considering inflation targeting framework.

Aspects de la syntaxe, de la semantique et de la morphologie des verbes a trait de /complexite/

Cette dissertation porte sur l’analyse syntactico-sémantique des verbes à trait de complexité. Le trait de complexité (Blanche-Benveniste et al. 1984) réunit une classe de verbes connue comme verbes ‘symétriques’, ‘réciproques’ ou ‘collectifs’ sans toutefois se limiter à ces ensembles (cf. grouiller, collectionner, amonceler, scinder, etc.). Ce trait induit une lecture ‘plurielle’ à l’entité formée du lexème verbal et de ses arguments et qui se traduit, sur le plan morphosyntaxique, par deux propriétés: sélection obligatoire d’une position syntaxique (sujet ou objet) au pluriel; en absence de ce pluriel morphologique, le trait de complexité se réalise par la sélection d’un complément prépositionnel correlié à une position syntaxique (sujet ou objet) et l’interprétation de ‘pluriel’ des deux éléments correliés. L’hypothèse générale, et point de départ de cette dissertation, consiste à préciser l’interprétation de ‘pluralité inhérente’ des verbes à trait de complexité comme étant de type ‘collectif’, défini comme désignant du ‘plus d’un en un’ (Jespersen, 1971). La notion de ‘collectif’ est à distinguer de la notion de ‘pluriel’ (Gillon, 1992) et permet d’expliquer le lien entre les deux propriétés morphosyntaxiques présentées. Cette hypothèse générale s’appuie sur la sélection d’un ensemble d’outils d’analyse. Un premier outil vise à rendre compte, du point de vue formel, des réseaux syntactico-sémantiques, par une représentation abstraite de la syntaxe verbale, conçue comme une ‘syntaxe de position’ et où sont délimitées, autour du noyau verbal, deux zones syntaxiques (zone SUJET et zone OBJET) constituées de points d’ancrage du trait de complexité. En tenant compte de la spécificité du ‘collectif’ par rapport à la ‘pluralité’, le recours au concept d’opérateurs de complexité, entendus comme des opérateurs du trait [+discret] (Doetjes, 1999), permet de mieux définir la notion du ‘collectif’ appliquée au domaine verbal. Les différents opérateurs – affixes dérivationnels, constructions prépositionnelles, constructions en SE - se situent à différents niveaux de structuration. L’analyse par ‘opérateurs de complexité’ ([+discret]) présuppose également la prise en compte de la fonction quantitative. Dans cette perspective, ces opérateurs induisent différents degrés de l‘individuation’ des constituants du ‘collectif’ dénoté par la sémantique des verbes à trait de complexité. Les échelles de gradation de [+discret] rendent compte de cette propriété. Les valeurs de ‘plus d’un’ et ‘en un’ dénotées par les expressions verbales à trait de complexité sont interprétées comme faisant partie d’une structure conceptuelle de type ‘tout-intégré’ d’après l’approche lexicale et multidimensionnelle de la sémantique conceptuelle des relations parties/tout de Moltmann (1997).

Structural Aspects of the Distinct Biochemical Properties of Glutaredoxin 1 and Glutaredoxin 2 from Saccharomyces cerevisiae

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Anthropometric aspects of body seated in school

This study aimed to assess the student-furniture interface from anthropometric parameters of the sitting posture. The sample was composed of 887 students from two public schools in the State of Parana - Brazil, which attended children from 7 to 17 years of age. The data collection used anthropometric measures of the sitting position, a questionnaire containing a human body diagram for indication of discomfort areas and photographic records to verify postural and ergonomic inadequacies in classroom. The following anthropometric variables were measured: popliteal height, sacro-popliteal length, hip width, lumbar support height, and elbow and thigh height. Percentiles 5 and 95 of anthropometric variables showed differences statistically significant, with variation coefficient greater than 30%. In relation to body discomfort, the highest occurrences were recorded for ankle, knees and shoulder joints as well as for spine and buttocks. It was concluded that children use school furniture that does not meet their anthropometric standards, which favored the adoption of incorrect postures and contributed to the emergence of musculoskeletal problems that can interfere with their educational process.

Perceptual aspects of the use of faucets (taps)

This paper presents an assessment with simulated activities with the aim of analyzing the perception of ease/difficulty of the use of faucets (taps) handles by 180 Brazilian adults. Five different handles faucets were activated for subsequent collection of perceptual data. The procedures were based on main recommendations for biomedical ethics and human research. The results indicate that handles with levers are significantly (p <= 0.05) easier to use. The most difficult are characterized by not having support points for the rotation (levers) or more points of pressure concentration in the hand.

Sensory aspects of liquid smoking of giant river prawn: comparison with traditional smoking

P>The purpose of this paper is to investigate the impact of liquid smoke on the sensory characteristics of giant river prawn (Macrobrachium rosenbergii). The sensorial profile was plotted using quantitative descriptive analysis and assessment of the acceptability of samples of beheaded and peeled and only beheaded freshwater prawns smoked using the traditional method or liquid smoke (LS). The prawns subjected to LS were characterised by their aroma, artificial flavour and bitter flavour. The beheaded, peeled prawns were found to be more acceptable, confirming that the presence of the shell is a limiting factor in the acceptability of smoked prawns.

Physical, chemical and microbiological aspects during the dry and rainy seasons in a pond covered by macrophyte used in aquaculture water supply

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)