Condition-dependence, pleiotropy and the handicap principle of sexual selection in melanin-based colouration.

The signalling function of melanin-based colouration is debated. Sexual selection theory states that ornaments should be costly to produce, maintain, wear or display to signal quality honestly to potential mates or competitors. An increasing number of studies supports the hypothesis that the degree of melanism covaries with aspects of body condition (e.g. body mass or immunity), which has contributed to change the initial perception that melanin-based colour ornaments entail no costs. Indeed, the expression of many (but not all) melanin-based colour traits is weakly sensitive to the environment but strongly heritable suggesting that these colour traits are relatively cheap to produce and maintain, thus raising the question of how such colour traits could signal quality honestly. Here I review the production, maintenance and wearing/displaying costs that can generate a correlation between melanin-based colouration and body condition, and consider other evolutionary mechanisms that can also lead to covariation between colour and body condition. Because genes controlling melanic traits can affect numerous phenotypic traits, pleiotropy could also explain a linkage between body condition and colouration. Pleiotropy may result in differently coloured individuals signalling different aspects of quality that are maintained by frequency-dependent selection or local adaptation. Colouration may therefore not signal absolute quality to potential mates or competitors (e.g. dark males may not achieve a higher fitness than pale males); otherwise genetic variation would be rapidly depleted by directional selection. As a consequence, selection on heritable melanin-based colouration may not always be directional, but mate choice may be conditional to environmental conditions (i.e. context-dependent sexual selection). Despite the interest of evolutionary biologists in the adaptive value of melanin-based colouration, its actual role in sexual selection is still poorly understood.

Parental body condition does not correlate with offspring sex-ratio in Cory's shearwater

We analyzed offspring sex ratio variation in Mediterranean Cory's Shearwater (Calonectris d. diomedea) during two consecutive breeding seasons in two colonies. We test for differential breeding conditions between years and colonies looking at several breeding parameters and parental condition. We then explored the relationship between offspring sex ratio and parental condition and breeding parameters. This species is sexually dimorphic with males larger and heavier than females; consequently we expected differential parental cost in rearing sexes, or a greater sensitivity of male chicks to adverse conditions, which may lead to biased sex ratios. Chicks were sexed molecularly by the amplification of the CHD genes. Offspring sex ratio did not differ from parity, either at hatching or fledging, regardless of the colony or year. However, parental body condition and breeding parameters such as egg size and breeding success were different between years and colonies. Nevertheless, neither nestling mortality nor body condition at fledging varied between years or colonies, suggesting that male and female chicks were probably not differentially affected by variability in breeding conditions.

Programa Leibniz: millora dels serveis bibliotecaris de la UPC

Postprint (published version)

A Method for Sky-Condition Classification from Ground-Based Solar Radiation Measurements

Identification of clouds from satellite images is now a routine task. Observation of clouds from the ground, however, is still needed to acquire a complete description of cloud conditions. Among the standard meteorologicalvariables, solar radiation is the most affected by cloud cover. In this note, a method for using global and diffuse solar radiation data to classify sky conditions into several classes is suggested. A classical maximum-likelihood method is applied for clustering data. The method is applied to a series of four years of solar radiation data and human cloud observations at a site in Catalonia, Spain. With these data, the accuracy of the solar radiation method as compared with human observations is 45% when nine classes of sky conditions are to be distinguished, and it grows significantly to almost 60% when samples are classified in only five different classes. Most errors are explained by limitations in the database; therefore, further work is under way with a more suitable database

Remote Condition Monitoring and Asset Management in Offshore Power Systems

Condition monitoring systems for physical assets are constantly becoming more and more common in the industrial sector. At the same time an increasing portion of asset monitoring systems are being remotely supported. As global competitors are actively developing solutions for condition monitoring and condition-based maintenance, which it enables, Wärtsilä too feels the pressure to provide customers with more sophisticated condition-based maintenance solutions. The main aim of this thesis study is to consider Wärtsilä remote condition monitoring solutions and how they relate to similar solutions from other suppliers and end customers’ needs, in the context of offshore assets. A theoretical study is also included in the thesis, where the concepts of condition monitoring, condition-based maintenance, maintenance management and physical asset management are introduced.

El juego y su estructura interna en relación con el trabajo de la condición física en primaria = Games and their internal structure in relation to the work of physical condition in Primary Education

One of the methodological resources that teachers use in a generalised way in Physical Education classes is the game. Inthis article we define the concept of game and analyse the characteristics of their internal structure. On the other hand welook at the concepts of physical condition and conditional skills and describe the objectives of its work in Primary Education.Finally, we relate these concepts and propose two practical examples of modifying the internal structure of the game so asto produce variations in the implied conditional skills

Callus cell culture of Pothomorphe umbellata (L.) under stress condition leads to high content of peroxidase enzyme

Pothomorphe umbellata (L.) known on Brazil as Caapeba has a number of popular medicinal use, and it has been studied in relation to its pharmacological activity. Peroxidase specific activity (units/mg protein) was evaluated in callus cell culture samples of the P.umbellata, grown in two different MS medium (media 1 and media 2), submitted to 16 hours photoperiod or kept in darkness. Cell growth rate curve showed that the best growth indices were observed when media 2 submitted to the photoperiod regime was used, followed by the same media kept in darkness (stress condition). The results obtained also showed that the cell culture grown under stress conditions (darkness) lead to high content of peroxidase enzyme (an increase of 700% was observed). Kinetic constant values of 3.3 mmol.L-1 and 2,8 sec-1 were obtained for kM and v max,, respectively, using guaiacol as enzyme substrate.

Leibniz's theory of bodies: monadic aggregates, phenomena, or both?

Leibniz's conception of bodies seems to be a puzzling theory. Bodies are seen as aggregates of monads and as wellfounded phenomena. This has initiated controversy and unending discussions. The paper attempts to resolve the apparent inconsistencies by a new and formally spirited reconstruction of Leibniz's theory of monads and perception, on the one hand, and a (re-)formulation and precisation of his concept of preestablished harmony, on the other hand. Preestablished harmony is modelled basically as a covariation between the monadic and the ideal realm.

Indiferença, simetria e perfeição segundo Leibniz

Na Teodicéia, Leibniz apresentatrês soluções para o sofisma de Buridan, em particular, e para o problema da liberdade de indiferença, em geral. A primeira refuta a idéia de que, mesmo em uma situação de perfeito equilíbrio e total ausência de uma razão determinante, os homens (diferentemente dos animais irracionais) seriam capazes de agir. As outras duas refutam diretamente a possibilidade de haver no universo tal situação de equilíbrio e simetria perfeitos, de modo que o próprio sofisma perde seu sentido.

Contingência e análise infinita em Leibniz

Leibniz afirma em diversas ocasiões que a análise infinita é o conceito central para explicar a compatibilização entre determinismo e contingência. Não é evidente, no entanto, por que a aplicação analógica de um conceito matemático, tal como o de cálculo infinitesimal, poderia solucionar esse problema ontológico, nem em que sentido deve-se entender tal analogia. O objetivo deste artigo é esclarecer esses dois pontos.

Leibniz e Hume sobre a indiferença

O artigo busca comparar algumas das razões diversas subjacentes à crítica comum de Leibniz e de Hume à idéia de uma liberdade de indiferença. Em Leibniz, como a ligação harmônica entre as substâncias individuais concretas se dá exclusivamente por meio de relações intrínsecas a seus conceitos completos, só é possível haver indiferença no domínio das noções incompletas ou de razão, o único em que podemos privilegiar e isolar termos e relações uns dos outros. Em Hume, a impossibilidade de fato de escaparmos da regularidade das relações extrínsecas, que, pela aplicação das regras gerais, acabam por se estender a toda a experiência, ainda que sem garantias racionais, relega a indiferença à situação quase fictícia de um estado original da mente, anterior à experiência, ou então ao domínio restrito de situações que provocam o afloramento desse estado no interior da experiência.

Possibilidade, compossibilidade e incompossibilidade em Leibniz

O presente artigo tem por objetivo tornar claro que há um problema referente à origem da incompossibilidade na metafísica de Leibniz, fornecendo, em um segundo momento, uma resposta ao problema.

Leibniz acerca de almas, corpos, agregados e substâncias na discussão com Fardella (1690)

Defendo neste artigo, contra a interpretação de Robert Adams, a tese de que, na discussão com Fardella (1690), Leibniz adota uma ontologia realista, segundo a qual seres vivos, e não almas, são substâncias.

LEIBNIZ Y LA FILOSOFÍA DE LA RELIGIÓN EN NISHIDA KITARÔ

ABSTRACT This paper is an analysis of the manner Nishida Kitarô (1870-1945), in the process of construction of his own philosophy of religion, enters into dialogue with Leibniz's thought concerning Pre-established Harmony. Although the philosophy of religion is an important theme and Nishida goes back to Leibniz at some points in his textual career, there are relatively few studies that touch on the relationship between these two thinkers. I study Nishida's approach under three headings. The first section concerns ten main aspects of the world of pre-established harmony. The second tries to show the manner in which such a world becomes a guide towards a philosophy of religion, placing the emphasis on three characteristically Christian aspects: a created, fallen, and Trinitarian world. The third section includes some elements such as the entrance into religion, metanoia, satori and a comparison between Christian agape and Buddhist maha-kruna. These are themes on which Nishida elaborates in his 1945 masterpiece, The Logic of Basho and a Religious Worldview.