Behavioral-Independent Features of Complex Heartbeat Dynamics

We test whether the complexity of cardiac interbeat interval time series is simply a consequence of the wide range of scales characterizing human behavior, especially physical activity, by analyzing data taken from healthy adult subjects under three conditions with controls: (i) a ``constant routine'' protocol where physical activity and postural changes are kept to a minimum, (ii) sympathetic blockade, and (iii) parasympathetic blockade. We find that when fluctuations in physical activity and other behavioral modifiers are minimized, a remarkable level of complexity of heartbeat dynamics remains, while for neuroautonomic blockade the multifractal complexity decreases.Comment: 4 pages with 6 eps figures. Latex file. For more details or for downloading the PDF file of the published article see http://polymer.bu.edu/~amaral/Heart.html and http://polymer.bu.edu/~amaral/Multifractal.htm

The Portuguese grapevine cultivar 'Amaral': synonymies, homonymies and misnames

Within Western Europe, Portugal is the country with highest diversity of grapevine cultivars. As the Iberian Peninsula has been considered a domestication centre of grapevines, the interest on Portuguese grapevine cultivars diversity has increased in the last years.Using twelve SSR markers scattered across twelve grape chromosomes, thirty-three accessions collected on Vinhos Verdes and Lafões Controlled Designations of Origin (DOC) and supposedly of the grapevine cultivar 'Amaral', were analysed. Names of the accessions ranged from 'Amaral' and 'Azal Tinto' to 'Sousão Galego'. Eight different genotypes were detected. The majority of accessions had the genotype attributed to 'Amaral'. However, three accessions were identified as misnaming cases and four genotypes were considered unknown, as no cultivar identification was achieved. Nevertheless, not only the misnamed cultivars, 'Vinhão', 'Melhorio' and 'Touriga Nacional', but also the four unknown genotypes, 'Azal Tinto' (AT2203 and AT2206), 'Amaral-1', 'Amaral-2' and 'Sousão Galego', share at least one allele in each of the 12 SSR loci analysed.The accessions AT2203 and AT2206 were found as possible offspring of 'Amaral' and 'Folgasão' and the accession 'Amaral-2' is likely result of a cross between 'Amaral' and 'Pedral'.The high number of synonym names that are attributed to 'Amaral', like 'Azal Tinto', 'Azar', 'Cainho' or 'Susão Galego' and the fact that it probably has parent-offspring relations with many cultivars, suggests that 'Amaral' is an ancient cultivar in the Northwest of the Iberian Peninsula and was a very important cultivar in the past.

The Web of Human Sexual Contacts

Many ``real-world'' networks are clearly defined while most ``social'' networks are to some extent subjective. Indeed, the accuracy of empirically-determined social networks is a question of some concern because individuals may have distinct perceptions of what constitutes a social link. One unambiguous type of connection is sexual contact. Here we analyze data on the sexual behavior of a random sample of individuals, and find that the cumulative distributions of the number of sexual partners during the twelve months prior to the survey decays as a power law with similar exponents $\alpha \approx 2.4$ for females and males. The scale-free nature of the web of human sexual contacts suggests that strategic interventions aimed at preventing the spread of sexually-transmitted diseases may be the most efficient approach.Comment: 7 pages with 2 eps figures. Latex file. For more details or for downloading the PDF file of the published article see http://polymer.bu.edu/~amaral/WebofContacts.html . For more results on teh structure of complex networks see http://polymer.bu.edu/~amaral/Networks.htm

A polyhedral study of triplet formulation for single row facility layout problem

AbstractThe single row facility layout problem (SRFLP) is the problem of arranging n departments with given lengths on a straight line so as to minimize the total weighted distance between all department pairs. We present a polyhedral study of the triplet formulation of the SRFLP introduced by Amaral [A.R.S. Amaral, A new lower bound for the single row facility layout problem, Discrete Applied Mathematics 157 (1) (2009) 183–190]. For any number of departments n, we prove that the dimension of the triplet polytope is n(n−1)(n−2)/3 (this is also true for the projections of this polytope presented by Amaral). We then prove that several valid inequalities presented by Amaral for this polytope are facet-defining. These results provide theoretical support for the fact that the linear program solved over these valid inequalities gives the optimal solution for all instances studied by Amaral

Dirce Waltrick do Amarante. Vitor Alevato do Amaral (Orgs.). Caetano W. Galindo: Entrevista.

Dirce Waltrick do Amarante. Vitor Alevato do Amaral (Orgs.). Caetano W. Galindo: Entrevista. Curitiba: Medusa, 2020.Dirce Waltrick do Amarante. Vitor Alevato do Amaral (Orgs.). Caetano W. Galindo: Entrevista. Curitiba: Medusa, 2020

Extinction events and species lifetimes in a simple ecological model

A model for large-scale evolution recently introduced by Amaral and Meyer is studied analytically and numerically. Species are located at different trophic levels and become extinct if their prey becomes extinct. It is proved that this model is self-organized critical in the thermodynamic limit, with an exponent 2 characterizing the size distribution of extinction events. The lifetime distribution of species, cutoffs due to finite-size effects, and other quantities are evaluated. The relevance of this model to biological evolution is critically assessed.Comment: 4 pages RevTex, including 3 postscript figure

Maria Adelaide Amaral ou a Crise da Classe Média Brasileira

Maria Adelaide Amaral ou a Crise da Classe Média Brasileir

Topics in Forecasting Macroeconomic Time Series

Koopman, S.J. [Promotor]Blasques Albergaria Amaral, F. [Copromotor

On observation-driven time series modeling

Koopman, S.J. [Promotor]Blasques Albergaria Amaral, F. [Copromotor