Aspectos acústicos do comportamento dos golfinhos

Este artigo pretende apresentar uma recolha bibliográfica de alguns dados e hipóteses relativos a adaptações sensoriais e comunicativas dos cetáceos, particularmente dos golfinhos. São consideradas as suas capacidades perceptivas e as potencialidades dos canais de comunicação de que dispõem, sendo realçada a sua considerável especialização na utilização do canal acústico. Depois de uma breve referência às suas capacidades auditivas concretas e às teorias explicativa da produção de vocalizações pelos golfinhos, sistematiza-se uma classificação dos sons por eles produzidos. São descritas características acústicas das vocalizações, sendo também discutidas as suas possíveis funções e a sua combinação com outros tipos de sinais no decurso das interacções sociais. Enquanto os trens de impulsos curtos ou estalidos são usados sobretudo na ecolocação, os estalos e os assobios, bem como alguns sons não-vocais, assumem fundamentalmente funções comunicativas. São ainda referidas questões metodológicas relacionadas com o estudo acústico das vocalizações dos cetáceos, sendo comparadas as vantagens e as desvantagens do trabalho no meio natural e em situações de cativeiro. ------ ABSTRACT ------ This paper presents a literature review of some data and hipotheses on perceptual and communicative adaptations of cetaceans, particulary of dolphins. Their perceptive capabilities and the comparative possibilities of the communication channels available to them are discussed, and their considerable specialization in the use of the auditory channel is stressed. After a brief review of their specific auditory capabilities and a reference to the theories of sound production by dolphins, a classification of their sounds is presented. Some acoustical characteristics of their vocalizations are described, and their possible functions and combination with other of signals used in social interactions are discussed. While click trains are mainly used in echolocation, burst-pulses and whistles, as well as some non-vocal signals, have a predominant communicative function. A reference is also made to the methods used in the acoustical study of cetacean vocalizations, with a comparison of the pros and cons of recording in the wild or in captivity

Jerónimo Martins Group international opportunities : a multinational group market selection decision process

This case study has been designed based on the Jerónimo Martins Group situation between 2007 and 2011 with the objective of acting as a teaching supplement in the study of companies’ international opportunities, market selection and the internationalization decision process utilized to reach an optimal decision for a company. Jerónimo Martins was the main Portuguese group in the food retail and wholesale industry, present in supermarkets, cash & carries and discount stores, and operating in Poland and Portugal. In 2011 Portugal was suffering the consequences of an economic recession, while the Polish food retail market was starting to consolidate, with the Group’s Polish operations representing more than half of Jerónimo Martins Group’s revenue. This situation led the Group CEO, together with the Board of Directors, to decide to explore new market and business opportunities to ensure the Group’s long-term growth. The Group’s decision process took into account the Jerónimo Martins characteristics, objectives, strengths and competences in order to define and compare new opportunities. According to the Group’s strategy specialists, Brazil, Colombia and Turkey were the final three countries chosen as the most promising markets: one of them would fulfil the Group’s needs and hopefully ensure its balanced long-term future. The Jerónimo Martins case was developed using information provided by the Group and also by international economic institutions so as to provide students with the most accurate information enabling them to solve the case

A Quantitative analysis of pulsed signals emitted by Wild Bottlenose Dolphins

Common bottlenose dolphins (Tursiops truncatus), produce a wide variety of vocal emissions for communication and echolocation, of which the pulsed repertoire has been the most difficult to categorize. Packets of high repetition, broadband pulses are still largely reported under a general designation of burst-pulses, and traditional attempts to classify these emissions rely mainly in their aural characteristics and in graphical aspects of spectrograms. Here, we present a quantitative analysis of pulsed signals emitted by wild bottlenose dolphins, in the Sado estuary, Portugal (2011-2014), and test the reliability of a traditional classification approach. Acoustic parameters (minimum frequency, maximum frequency, peak frequency, duration, repetition rate and inter-click-interval) were extracted from 930 pulsed signals, previously categorized using a traditional approach. Discriminant function analysis revealed a high reliability of the traditional classification approach (93.5% of pulsed signals were consistently assigned to their aurally based categories). According to the discriminant function analysis (Wilk's Λ = 0.11, F3, 2.41 = 282.75, P < 0.001), repetition rate is the feature that best enables the discrimination of different pulsed signals (structure coefficient = 0.98). Classification using hierarchical cluster analysis led to a similar categorization pattern: two main signal types with distinct magnitudes of repetition rate were clustered into five groups. The pulsed signals, here described, present significant differences in their time-frequency features, especially repetition rate (P < 0.001), inter-click-interval (P < 0.001) and duration (P < 0.001). We document the occurrence of a distinct signal type-short burst-pulses, and highlight the existence of a diverse repertoire of pulsed vocalizations emitted in graded sequences. The use of quantitative analysis of pulsed signals is essential to improve classifications and to better assess the contexts of emission, geographic variation and the functional significance of pulsed signals.Fundação para a Ciência e Tecnologia - FCTinfo:eu-repo/semantics/publishedVersio

Nanocrystalline cathodes for PC-SOFCs based on BCZY

Perovskites based on BaCeO3-δ exhibit the highest proton conductivity among this class of materials, however, they are susceptible to hydration and carbonation in presence of water vapor and CO2 [1]. In contrast, the chemical stability of BaZrO3-based protonic conductors is better, but they require sintering temperatures as high as 1700 ºC and suffer from high intrinsic grain boundary resistance, limiting the final performance. Partial substitution of Zr for Ce in Ba(Ce0.9-xZrx)Y0.2O3-δ allows obtaining electrolytes with both high proton conductivity and good chemical stability. The performance of a PC-SOFC at low temperatures depends significantly on the ohmic resistance of the electrolyte, although it can be lowered by reducing the electrolyte thickness. Another important limiting factor is the increase of the cathode polarization resistance due to the thermally activated nature of the oxygen reduction reaction. For this reason, it is essential to obtain high efficiency cathodes operating at reduced temperatures. In this work, BaCe0.6Zr0.2Y0.2O3-δ (BCZY) powders were prepared by freeze-drying precursor method. These powders were mixed with a Zn-containing solution as sintering additive in order to obtain dense pellets with submicrometric grain size at only 1200 ºC. After that, La0.6Sr0.4Co0.8Fe0.2O3 nanocrystalline electrodes were deposited symmetrically onto dense pellets BCZY by conventional spray-pyrolysis [3]. The structure, microstructure and electrochemical properties of these electrodes have been examined by XRD, FE-SEM and impedance spectroscopy. The stability of these electrodes at intermediate temperatures was evaluated as a function of time. These nanocrystalline cathodes exhibit a substantial improvement of the electrode polarization resistance with respect to the same materials prepared by screen-printing method at high sintering temperatures, e.g. 0.7 and 3.2 cm2 at 600 ºC for LSCF cathodes prepared by spray-pyrolysis and screen-printing method respectively (Figure). An anode supported cell with composition LSCF/BCZY/NiO-BCZY was also prepared to test the electrochemical performance.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Holistic evaluation of the potencial performance of the chief information officer

At the position of senior leader for the organization and Information Systems Function management, we find the Information Systems Manager. Given the nature of the activities that he needs to accomplish, his action influences unfailingly the development of the organization in which he is engaged with. Thus, it is important to evaluate the potential performance of the candidates chosen to occupy that role, before being placed at the control of a determinant function for the business success. This article presents an extension of the 'Model for the Evaluation of Potential Performance of Information Systems Managers' considering, for the potential performance of the chief information officer, the dimensions Experience, Education and Psychosocial characteristics.Na posição de responsável máximo pela organização e direção da Função Sistemas de Informação, encontramos o Gestor de Sistemas de Informação. Dada a natureza das atividades que necessita de realizar, a sua ação influencia incontornavelmente o desenvolvimento da organização com que colabora. É, assim, importante avaliar o desempenho potencial de candidatos a ocupar este lugar, antes de serem colocados ao comando de uma função determinante para o sucesso do negócio. O presente artigo apresenta uma extensão do “Modelo para a Avaliação do Desempenho Potencial de Gestores de Sistemas de Informação”, considerando para a avaliação do desempenho potencial do gestor de sistemas de informação, as dimensões Experiência, Formação e Características Psicossociais.info:eu-repo/semantics/publishedVersio

The relevance of competitiveness on entrepreneurship : evidence for different country's development stage

Mestrado em Ciências EmpresariaisNum mundo dinâmico como o de hoje, o empreendedorismo revelou-se como uma forma de sobressair e de ganhar vantagens competitivas como vários estudos têm demonstrado ao longo dos anos. Uma questão que se encontra ainda por responder, a qual endereçamos neste trabalho, é como a competitividade afeta o empreendedorismo. Utilizaram-se os pilares do Global Competitiveness Index (GCI) - instituições, infraestruturas, ambiente macroeconómico, saúde e educação primária, formação e educação superior, eficiência de mercado dos bens, eficiência do mercado laboral, desenvolvimento do mercado financeiro, preparação tecnológica, dimensão do mercado, sofisticação do negócio e inovação - que, todos juntos, definem a competitividade de uma nação, e os dados provenientes da Total early-stage Entrepreneurial Activity (TEA), desde 2006 até 2015. Adicionalmente, utilizando a classificação de Porter, dividimos os países em factor-, efficiency- e innovation driven economies, por forma a perceber como a competitividade afeta o empreendedorismo de acordo com o grau de desenvolvimento económico de cada nação. Verificámos individualmente como cada pilar afeta o empreendedorismo em geral e para cada estádio. Os resultados obtidos demonstram algumas relações esperadas entre os pilares da competitividade e o empreendedorismo, mas provam também que alguns conceitos suprimem o empreendedorismoIn a dynamic world as today, entrepreneurship has revealed itself as a way of standing out and gaining competitive advantages as several studies have shown in the past years. One main question that is left to understand, which we address in this work, is how competitiveness affects entrepreneurship. We used Global Competitiveness Index's 12 pillars - institutions, infrastructures, macroeconomic environment, health and primary education, higher education and training, goods market efficiency, labor market efficiency, financial market development, technological readiness, market size, business sophistication and innovation - which, together, define a nation's competitiveness, and used data related to the Total early-stage Entrepreneurial Activity from 2006 to 2015. Additionally, using Porter's classification, we divided countries in factor, efficiency and innovation-driven economies to understand how competitiveness affects entrepreneurship according to a country's stage of economic development. We individually check how each pillar affects entrepreneurship in general and for each stage. The results show some expected significant relations between competitiveness's pillars but also proves some concepts supress entrepreneurship.info:eu-repo/semantics/publishedVersio

Wind-CSP short-term coordination by MILP approach

This paper is on the maximization of total profit in a day-ahead market for a price-taker producer needing a short-term scheduling for wind power plants coordination with concentrated solar power plants, having thermal energy storage systems. The optimization approach proposed for the maximization of profit is a mixed-integer linear programming problem. The approach considers not only transmission grid constraints, but also technical operating constraints on both wind and concentrated solar power plants. Then, an improved short-term scheduling coordination is provided due to the more accurate modelling presented in this paper. Computer simulation results based on data for the Iberian wind and concentrated solar power plants illustrate the coordination benefits and show the effectiveness of the approach

Revisiting the North American freshwater mussel genus Quadrula sensu lato (Bivalvia Unionidae): phylogeny, taxonomy and species delineation

© 2019 Royal Swedish Academy of Sciences Freshwater mussels (Bivalvia, Unionidae) have suffered strong declines over the last century. High morphological plasticity of Unionidae causes disturbances in their systematics and taxonomy, hampering conservation efforts. Species that have historically been placed under the North American genus Quadrula have suffered from numerous taxonomic and species delineation problems since its inception. Four genera are presently recognized within Quadrula sensu lato, that is, Cyclonaias, Quadrula, Theliderma and Tritogonia, but their phylogenetic basis remains incompletely tested. In the present study, we reconstructed several two-marker (mtDNA cytochrome c oxidase subunit I—COI and NADH dehydrogenase subunit 1—ND1) phylogenies with newly collected specimens and all previously available sequences covering most species within this group. We then delineated the species within the group using an integrative approach with the application of molecular statistical methods, morphometric (Fourier Shape) analyses and geographic distribution data. Four clades corresponding to these genera were consistently recovered in all phylogenies. To validate the generic status of these clades, molecular analyses were complemented with morphological, anatomical and ecological data compiled from the literature. Several revisions are here proposed to the current systematics and taxonomy of these genera, including the synonymization of Cyclonaias asperata under Cyclonaias kieneriana; the inclusion of Quadrula apiculata and Quadrula rumphiana under Quadrula quadrula; the placement of Quadrula nobilis under Tritogonia; and finally the separation of the Mobile River basin populations of Theliderma metanevra as a new species, that is, Theliderma johnsoni n. sp. The conservation implications of the proposed changes are then discussed

A participação dos trabalhadores na construção dos programas de integridade corporativa

This article focuses on compliance in the Brazilian law, in the framework of the moral, political and legal criticism on the cleavage between ethics and economics that marks ultracompetitive capitalism. In this context, it claims that employee participation is an important condition of effectiveness in compliance actions and programs. Their participation is also conceived as an important step to overcome the views according to which commitment to integrity is just an external constraint to economic decisions.Keywords: compliance, capitalism, ethics, economy, employee participation.Este artigo examina os programas de integridade corporativa no direito brasileiro, no quadro da crítica moral, política e jurídica à cisão entre ética e economia que marca o capitalismo ultracompetitivo contemporâneo. Nesse quadro, examina-se a conveniência da participação dos empregados na construção dos programas de compliance, participação esta concebida como importante apoio tanto da sua efetividade dos programas de integridade como da superação de um modelo de atividade empresarial que compreenda o compromisso com a integridade como um mero limitador externo à ação empresarial.Palavras-chave: integridade corporativa, combate à corrupção, capitalismo, ética, economia, participação dos empregados

Longitudinal development of 5m sprint performance in young female tennis players

Sprint performance over short distances is a central component in young tennis players' development. This study aimed to examine the longitudinal development of sprint performance in young female tennis players, and to investigate differences between performance levels. Also potentially explanatory variables were investigated. Female tennis players aged 10-15 (N= 167) participated in a, mixed-longitudinal study (n= 48 elite;n= 119 sub-elite). Players were measured annually on the 5 m sprint as well as for possible explaining variables for 5 m sprint performance development (age, height, body mass, maturity status, lower limb explosive strength). Multilevel analysis was used to obtain a developmental model. Moreover, it was possible to predict sprint performance (5 m) based on chronological age, body size given by height, and lower limb strength performance (p . 05). Sprint performance is an important characteristic of young female tennis players and seemed to depend on growth and maturation in parallel to physical fitness