Nonlinear bivariate comovements of asset prices: Theory and tests

Comovements among asset prices have received a lot of attention for several reasons. For example, comovements are important in cross-hedging and cross-speculation; they determine capital allocation both domestically and in international mean–variance portfolios and also, they are useful in investigating the extent of integration among financial markets. In this paper we propose a new methodology for the non–linear modelling of bivariate comovements. Our approach extends the ones presented in the recent literature. In fact, our methodology outlined in three steps, allows the evaluation and the statistical testing of non-linearly driven comovements between two given random variables. Moreover, when such a bivariate dependence relationship is detected, our approach solves for a polynomial approximation. We illustrate our three–steps methodology to the time series of energy related asset prices. Finally, we exploit this dependence relationship and its polynomial approximation to obtain analytical approximations of the Greeks for the European call and put options in terms of an asset whose price comoves with the price of the underlying asset

Custos de transação e comportamento da base para o preço do milho em Rio Verde, GO.

O objetivo deste trabalho foi analisar o comportamento da base, que é a diferença entre o preço do milho de Rio Verde, GO, e o preço futuro do milho na BM&FBovespa de 3/1/2005 até 15/3/2011. Por conseguinte, a hipótese do estudo é que os custos de transação e as características regionais da comercialização do milho fazem que ocorra elevada divergência de preços entre os mercados. O modelo autorregressivo com threshold (TAR) foi usado para captar as importantes dimensões dos custos de transação. Os resultados estimados para o parâmetro TAR de 7,78% mostram uma fraca convergência entre os preços dos mercados e, por consequência, o enfraquecimento da base na região. Isso evidencia que os produtores minimizam custos de transação regionais e, por isso, estão mais preocupados com as transações de hedging privado no mercado físico, não recorrendo à bolsa de valores para proteção contra oscilação de preços

First observational evidence of a relation between globular clusters' internal rotation and stellar masses

Several observational studies have shown that many Galactic globular clusters (GCs) are characterised by internal rotation. Theoretical studies of the dynamical evolution of rotating clusters have predicted that, during their long-term evolution, these stellar systems should develop a dependence of the rotational velocity around the cluster's centre on the mass of stars, with the internal rotation increasing for more massive stars. In this paper we present the first observational evidence of the predicted rotation-mass trend. In our investigation, we exploited the $\mathit{Gaia}$ Data Release 3 catalogue of three GCs: NGC 104 (47 Tuc), NGC 5139 ($\omega$ Cen) and NGC 5904 (M 5). We found clear evidence of a cluster rotation-mass relation in 47 Tuc and M 5, while in $\omega$ Cen, the dynamically youngest system among the three clusters studied here, no such trend was detected.Comment: 6 pages, 4 figures, 1 table. Accepted for publication in MNRAS Letter

Rhabdomyolysis: a genetic perspective

Rhabdomyolysis (RM) is a clinical emergency characterized by fulminant skeletal muscle damage and release of intracellular muscle components into the blood stream leading to myoglobinuria and, in severe cases, acute renal failure. Apart from trauma, a wide range of causes have been reported including drug abuse and infections. Underlying genetic disorders are also a cause of RM and can often pose a diagnostic challenge, considering their marked heterogeneity and comparative rarity.In this paper we review the range of rare genetic defects known to be associated with RM. Each gene has been reviewed for the following: clinical phenotype, typical triggers for RM and recommended diagnostic approach. The purpose of this review is to highlight the most important features associated with specific genetic defects in order to aid the diagnosis of patients presenting with hereditary causes of recurrent RM

Applicability of the cobb angle measurement in idiopathic scoliosis using scanned imaging

OBJECTIVES: To compare the measurement of the Cobb angle on printed radiographs and on scanned radiographs viewed through the software "PixViewer". METHODS: Preoperative radiographs of 23 patients were evaluated on printed films and through the software "PixViewer". The same evaluator, a spine surgeon, chose the proximal and distal limiting vertebrae of the main curve on printed radiographs, without identification of patients, and measured the Cobb angle based on these parameters. The same parameters and measurements were applied to scanned radiographs. The measurements were compared, as well as the choice of limiting vertebrae. RESULTS: The average variation of the Cobb angle between methods was 1.48 ± 1.73°. The intraclass correlation coefficient (ICC) was 0.99, demonstrating excellent reproducibility. CONCLUSION: The Cobb method can be used to evaluate scoliosis through the "PixViewer" tool with the same reliability as the classic method on printed radiographs

Theranostics in Boron neutron capture therapy

Boron neutron capture therapy (BNCT) has the potential to specifically destroy tumor cells without damaging the tissues infiltrated by the tumor. BNCT is a binary treatment method based on the combination of two agents that have no effect when applied individually:10B and thermal neutrons. Exclusively, the combination of both produces an effect, whose extent depends on the amount of10B in the tumor but also on the organs at risk. It is not yet possible to determine the10B concentration in a specific tissue using non-invasive methods. At present, it is only possible to measure the10B concentration in blood and to estimate the boron concentration in tissues based on the assumption that there is a fixed uptake of10B from the blood into tissues. On this imprecise assumption, BNCT can hardly be developed further. A therapeutic approach, combining the boron carrier for therapeutic purposes with an imaging tool, might allow us to determine the10B concentration in a specific tissue using a non-invasive method. This review provides an overview of the current clinical protocols and preclinical experiments and results on how innovative drug development for boron delivery systems can also incorporate concurrent imaging. The last section focuses on the importance of proteomics for further optimization of BNCT, a highly precise and personalized therapeutic approach