Length-weight relationships of marine fishes from the central Brazilian coast

Parameters of the length-weight relationship are presented for 85 fish species from the marine and estuarine regions of the central Brazilian coast (latitude 13° to 23° S). Three different methods were used. A non-linear iterative process using the quasi-Newton algorithm yielded a better fit for all data sets analyzed. The length-weight allometry coefficient b estimated from standard length data tended to be lower than from total length data. The difference between these estimates was significant for some species

Length-weight relationships of marine fishes from the central Brazilian coast

Parameters of the length-weight relationship are presented for 85 fish species from the marine and estuarine regions of the central Brazilian coast (latitude 13° to 23° S). Three different methods were used. A non-linear iterative process using the quasi-Newton algorithm yielded a better fit for all data sets analyzed. The length-weight allometry coefficient b estimated from standard length data tended to be lower than from total length data. The difference between these estimates was significant for some species.Length-weight relationships, Marine fish, Stock assessment, Brazil,

Human capital and corruption: a microeconomic model of the bribes market with democratic contestability

To overcome market failures society creates common laws that stimulate or penalize individual actions, the enforcement of which depends on the actions of public authorities who may be susceptible to corruption. Thus, a new market emerges where ‘influences’ are traded. Legislators have incentives to deviate from the goal of efficiency and produce laws that maximize the gains that can be expected from bribes. We model this behaviour for an autocracy versus a democracy, using a microeconomic framework. We assume that in an autocracy rulers have a monopoly over the bribes market, whereas in a democracy conflicting groups compete in the bribes market. In order to bring about the downfall of the incumbent rulers, these groups inform voters of the rulers' deviant actions so that, by a stochastic process, they convince voters of the existence of bribes and therefore gain their votes. The models constructed produce results that are compatible with the well-known stylized facts, namely that (1) in a democracy the level of corruption is lower than in an autocracy, although still positive, that (2) in environments where the level of human capital is higher (the proxy for the voters’ receptivity to the efforts of the opposition), regimes are closer to democracies and the level of corruption is lower, and that (3) the level of corruption is higher in more regulated economies.Human capital; corruption; democracy; computational models

What type of firm forges closer innovation linkages with Portuguese Universities?

Using large-scale survey data for (1538) firms located in Portugal, we analyze which firm characteristics are conducive to establishing contacts with universities. Although almost half of the firms surveyed stated they had established some contacts with universities in the period 2001-2003, only a few (21.5%) consider universities an important source of knowledge and information for their innovation activities. A more disturbing finding is that 61% of the total firms claimed they had no intentions of establishing future contacts with universities and 38% would only be moderately interested in doing so (‘if requested’). The Universities of Minho, Porto and Aveiro are the ones that cover a higher percentage of contacts from firms. Furthermore, in terms of the most demanding type of contacts (protocols, partnerships and projects), the Técnica de Lisboa (Lisbon Technical), Aveiro and Porto are the best-ranked universities. Our analysis indicates that the firms’ propensity to draw on each of the Portuguese universities is explained by the characteristics of the different firms and their regional and industrial patterns. For instance, firms that have established contacts with the Aveiro, Coimbra, Évora, Lisboa, and the Nova (Lisbon) universities tend to be relatively R&D-intensive, whereas those that contact the Católica (Porto) and Porto universities are relatively large and export-intensive. If we exclude the Algarve and Beira Interior universities, firms that contact all the other universities tend to be relatively human capital-intensive. Firms belonging to ‘R&D and Engineering services’ show a relatively high propensity to draw on universities in general, and the Aveiro, Beira Interior, Católica (Porto), Porto and Técnica de Lisboa universities, in particular. ‘Textiles and leather’ firms establish more contacts with the Beira Interior and Minho universities, thus reflecting to some extent the specialization pattern of the corresponding region. An unambiguous and statistically robust finding is that proximity matters highly in firms-universities linkages - our estimations reveal that firms are more likely to contacts universities located nearby.University, Firm, linkages

Signalling by tips

New molecules, including protein kinases, lipids and molecules that have neurotransmitter activities in animals have emerged as important players in tip-growing cells. Transcriptomics analysis reveals that the largest single class of genes expressed in pollen tubes encode signal transducers, reflecting the necessity to decode complex and diverse pathways that are associated with tip growth. Many of these pathways may use common intracellular second messengers, with ions and reactive oxygen species emerging as two major common denominators in many of the processes involved in tip growth. These second messengers might influence the actin cytoskeleton through known interactions with actin-binding proteins. In turn, changes in the dynamic properties of the cytoskeleton would define the basic polarity events needed to shape and modify tip-growing cells

An approach to cork oak forest management planning: a case study in southwestern Portugal

This paper presents results of research aiming at the development of tools that may enhance cork oak (Quercus suber L.) forest management planning. Specifically, it proposes an hierarchical approach that encompasses the spatial classification of a cork oak forest and the temporal scheduling of cork harvests. The use of both geographical information systems and operations research techniques is addressed. Emphasis is on the achievement of cork even flow objectives. Results from an application to a case study in the Charneca Plioce´nica of Ribatejo in southern Portugal encompassing a cork oak forest extending over 4.8 thousand ha are discussed. They suggest that the proposed approach is capable of effective spatial classification of cork oak management units. They further suggest that it may be used to select optimal cork even flow scheduling strategies. Results also show that the proposed approach may lead to a substantial increase in net present value when compared to traditional approaches to cork oak forest management planning

Clinical quiz.

J Pediatr Gastroenterol Nutr. 2005 Oct;41(4):483-4, 484. Clinical quiz. Prior AC, Selores M, Pina R, Dias JA, Costa FM, Vale L, Gomes L. Department of Pediatrics, Hospital Geral de Santo António, Portugal. PMID: 16205521 [PubMed - indexed for MEDLIN

Uma experiência com mapas conceituais na formacão inicial de professores de ciências: a argumentaçao como temática

O objetivo deste estudo é apresentar considerações sobre a potencialidade do uso do Mapa Conceitual como instrumento fornecedor de evidências da aprendizagem de licenciandos em Ciências Exatas, no que concerne à temática argumentação em aulas de Ciências. Fizeram parte deste estudo cinco licenciandos que individualmente confeccionaram um mapa sobre aspectos fundamentais para se criar um ambiente argumentativo em sala de aula. Foi possível identificar pelo mapa os conceitos representativos dos conteúdos sobre a argumentação abordados pelos licenciandos e como estes os relacionavam entre si, indicando o grau de entendimento do conteúdo de cada um. Além disso, considera-se que o mapa também contribuiu para a aprendizagem dos licenciandos uma vez que tiveram que organizar de forma interligada os diversos conceitos

Microwave dielectric permittivity and photoluminescence of Eu 2O3 doped laser heated pedestal growth Ta 2O5 fibers

Partilhar documento na coleção da comunidade Laboratório Associado I3NWe report the microwave dielectric properties and photoluminescence of undoped and europium oxide doped Ta2O5 fibers, grown by laser heated pedestal growth technique. The effects of Eu2O3 doping 1–3 mol % on the structural, optical, and dielectric properties were investigated. At a frequency of 5 GHz, the undoped material exhibits a dielectric permittivity of 21 and for Eu2O3 doped Ta2O5 samples it increases, reaching up to 36 for the highest doping concentration. Nevertheless, the dielectric losses maintain a very low value. For this wide band gap oxide, Eu3+ optical activation was achieved and the emission is observed up to room temperature. Thus, the transparency and high permittivity make this material promising for electronic devices and microwave applications. © 2008 American Institute of Physics.FCT-PTDC/FIS/66262/06FCT-PTDC/CTM/66195/200