Weight–length relationships of four intertidal mollusc species from the northeastern Atlantic Ocean and their potential for conservation

Weight-length relationships (WLRs) are frequently used for the development of comparative studies of life history, population dynamics, ecosystem modelling and estimation of the production and biomass of populations among regions. WLRs provide information about growth, wellbeing and fitness of a population in a marine environment. WLRs for four topshells (Phorcus atratus, Phorcus lineatus, Phorcus mariae, Phorcus sauciatus) caught in North-eastern Atlantic Ocean (Azores, Canaries, Cape Verde, Madeira and Mainland Portugal) were established and their relative growth was assessed. The results showed that almost all species exhibited a positive allometric growth. A comparative study on the effect of harvest in the relative growth of P. sauciatus in the archipelago of Madeira showed that all the populations from exploited areas exhibited a negative allometric growth in contrast to the populations from the Marine Protected Areas (MPAs) which were predominantly isometric. The present results indicate that the conservation measures established in the protected areas promoted a positive effect in the protected populations and are valuable for establishing a set of monitoring and management measures aiming at the sustainable exploitation and conservation of these species. These results are important to demonstrate the role of MPAs in the conservation of these keystone species in the north eastern Atlantic Ocean rocky shore ecosystems.info:eu-repo/semantics/publishedVersio

Unravelling the effects of exploitation on the size–structure of the intertidal topshell Phorcus sauciatus in harvested and non-harvested Atlantic regions

Intertidal molluscs are keystone species often used as biological indicators of human-driven pertur bations. The increasing levels of harvesting pressure on these intertidal grazers, due to the expansion of human population on coastal areas, is known to affect negatively the exploited populations by altering population size–structure and decreasing abundances. A comparative study on the effect of harvest on the size–structure of Phorcus sauciatus populations was conducted according to the exploitation level, harvested and non-harvested, throughout the intertidal zone of mainland Portugal, Azores, Madeira, and the Canaries. The comparative analysis of the size–structure of 10,480 individuals of P. sauciatus showed that the largest individuals were recorded in the Azores and the smallest in Madeira. In harvested populations, P. sauciatus showed to be under greater harvesting pressure in the archipelago of Madeira, where the lowest mean size was observed. In the Canaries the harvesting is regulated whilst in the mainland Portugal the regulation is scarce. The Azores showed no harvesting pressure. Marine Protected Areas showed individuals with the highest mean sizes supporting their effectiveness in preserving the size–structure of this species, regardless the ecoregion and thus, the harvesting pressure. The present results highlight the importance of harvesting regulation of P. sauciatus in Madeira, as well as the implementation of management measures aiming at the sustainable exploitation and conservation of this species.info:eu-repo/semantics/publishedVersio

Regional imbalances and market potential in Brazil

Brazil presented in the last 30 years not only periods of economic growth but also crises and stagnation. The Brazilian regions’ performance (in face of the challenges and opportunities presented during this period) was not even at all, as we can see by the massive regional imbalances around the country. Various approaches have tried to understand this reality of economic activity spatial concentration. Among them, the emerging New Economic Geography (NEG). Could this theory comprehend and explain the regional unevenness on wages among Brazilian municipalities over the recent decades? Using 1980, 1991 and 2000 Brazilian Census data (at comparables municipalities areas), this paper aims to estimate the NEG wage equation, using panel data model with spatially correlated errors components. The results point to a strong relationship between market potential and wages, indicating that the NEG theoretical framework might be well fit to recent Brazilian municipalities’ reality.New economic geography, market potential, Brazil

Thinking of fish population discrimination: population average phenotype vs. population phenotypes

The genetic polymorphism and phenotypic variation are key in ecology and evolution. The morphological variability of the contour of fish otoliths has been extensively used for the delimitation of stocks. These studies are conventionally based on average phenotype using elliptic Fourier analysis and lineal discriminant analysis as classifier. Considering new analytical options, such as the wavelet transformand non-parametric algorithms, we here analyzed the otolith shape of Trachurus picturatus (blue jack mackerel) from mainland Portugal, Madeira, and the Canaries. We explore the phenotypic variation throughout a latitudinal gradient, establish a hypothesis to explain this variability based on the reaction norms, and determine how the use of average phenotype and/or morphotypes influences in the delimitation of stocks. Four morphotypes were identified in all regions, with an increase of phenotypes in warmer waters. The findings demonstrated that stocks were clearly separated with classification rates over 90%. The use of morphotypes, revealed seasonal variations in their frequencies and per region. The presence of shared phenotypes in different proportions among fishing grounds may open new management approaches in migratory species. These results show the importance of the phenotypic diversity in fisheries management.Preprin

Evaluation of DoS attacks on Commercial Wi-Fi-Based UAVs

One of the biggest challenges for the use of Unmanned Aerial Vehicles (UAVs) in large-scale real-world applications is security.  However, most of research projects related to robotics does not discuss security issues, moving on directly to studying classical problems (i.e., perception, control, planning). This paper evaluates the effects of availability issues (Denial of Service attacks) in two commonly used commercially available UAVs (AR.Drone 2.0 and 3DR SOLO). Denial of Service (DoS) attacks are made while the vehicles are navigating, simulating common conditions found both by the general public and in a research scenario. Experiments show how effective such attacks are and demonstrate actual security breaches that create specific vulnerabilities. The results indicate that both studied UAVs are susceptible to several types of DoS attacks which can critically influence the performance of UAVs during navigation, including a decrease in camera functionality, drops in telemetry feedback and lack of response to remote control commands. We also present a tool that can be used as a failsafe mechanism to alert the user when a drone is reaching out a determined flight limit range, avoiding availability issues

A tomada de decisões conservacionistas baseadas em informações sobre a biodiversidade em empreendimentos hidrelétricos na Bacia Amazônica

Environmental impact studies (EIAs) are used to understand the potential impacts of a construction and to suggest whether the project is viable under the environmental point of view. However, few ecological tools of analysis are currently used for this conclusion. One of them is the legal requirement for the stabilization of the collector curve, which has been strongly accepted by the consultants and employees of Ibama (Brazilian Institute of Environment and Renewable Natural Resources) because it is well known and used by some researchers in the world to analyze EIAs. However, the assumptions of the analysis are rarely found in real decision-making situations about hydroelectric dams. The main factor that prevents its use is the impossibility of performing random sampling in large areas of difficult access. In some spatial scales, the absence of randomization is not relevant, but this is not the case with hydroelectric projects in the Amazon basin. If this assumption can not be met, decision-making based on the collector curve is not informative about the validity of the sampling. The species richness measured by the collector curve has had little applicability by conservation biology. Knowledge of the elements of biodiversity present is considered more relevant today and, therefore, sampling in all area of inference is a more useful recommendation, since knowledge of less rare species can give more support in decision making. Complementarity is the current paradigm of conservation biology that relies on some widely used algorithms and analytical tools in the world. Choosing conservation targets that should be considered relevant is a critical part of this process. Initially, we considered the list of targets presented in the EIAs, those required by the legislation, and also those listed at a workshop of researchers on hydroelectric dams in the Tapajós River basin. The selection of priority targets was made in this study through the spatial overlap of these initial targets with all the dams built and planned in the Amazon basin. The analyzes indicated that only aquatic targets were threatened by dams, and the use of a high number of targets may lead to the erroneous conclusion that there is little impact on the targets analyzed. The Tapajós basin is planned to receive the greatest investment in construction of new dams by the current proposal of the Brazilian Ministry of Mines and Energy. Using only the targets that were selected in Chapter 2, a simulation of dam combinations was made by contrasting the hydroelectric potential and the degradation in biodiversity that each potential combination could cause. By means of the Pareto frontier analysis, some arrangements of dams have resulted in “win-win” situations, showing that energy production can be compatible with environmental preservation, but these best combinations are not the current government's proposal. One of the most efficient points showed that it is possible to produce 78% of the potential electricity with a loss of 21% of biodiversity compared to the current government proposal. All the results were strongly influenced by the choice of the analyzed targets and these should be investigated more thoroughly before hydroelectric decisions are made in the basin.O Estudo de Impacto Ambiental - EIA é utilizado para entender os impactos de uma intervenção humana no meio ambiente e sugerir se o empreendimento é ou não viável sob o ponto de vista ambiental. No entanto, atualmente, são usadas poucas ferramentas ecológicas de análise para embasar essa conclusão. Uma delas é a exigência legal da estabilização da curva do coletor, que tem um forte aceite pelas empresas de consultoria e pelos órgão licenciadores porque é bem conhecida e utilizada por alguns pesquisadores no mundo para analisar EIAs. Entretanto, as premissas da análise raramente são encontradas em situações reais de tomada de decisão sobre hidrelétricas. No capítulo 1 analisamos se o estimador de número de espécies dado pela Curva do Coletor é robusta a essa ausência de premissas. Utilizamos anuros como o elemento da fauna porque eram os dados disponíveis nos 4 sítios de amostragem. O principal fator que impede o uso da curva do coletor é a impossibilidade de se realizar amostragens aleatórias em grandes áreas de difícil acesso. Em algumas escalas espaciais, a ausência de aleatorização não é relevante, mas esse não é o caso de empreendimentos hidrelétricos na bacia amazônica. Na impossibilidade de atender a esse pressuposto, a tomada de decisão baseada em curva do coletor é pouco elucidativa sobre a validade da amostragem. A riqueza de espécies estimada pela curva do coletor tem tido pouca aplicabilidade pela biologia da conservação. O conhecimento dos elementos da biodiversidade presentes é considerado mais relevante atualmente e, portanto, a realização de amostragens em toda área de inferência é uma recomendação mais útil, pois o conhecimento das espécies menos raras pode ajudar mais na tomada de decisão. A complementaridade é o atual paradigma da biologia da conservação, que conta com alguns algoritmos e ferramentas largamente usadas no mundo. Os mais comuns desses algorítimos podem ser nomeados de Planejamento Sistemático da Conservação (PSC), que é uma lógica que estabelece algumas etapas fundamentais que o processo de decisão deve seguir até chegar a se discutir o que deve ou não ser preservado. Escolher os alvos que devem ser considerados como relevantes é parte crítica desse processo. No capítulo 2 realizamos essa etapa do PSC e procuramos estabelecer os alvos para a região hidrográfica da Amazônia brasileira que estão ameaçadas pelas hidrelétricas a serem instaladas. Para isso, inicialmente consideramos a lista de alvos apresentadas nos EIAs, aqueles exigidos pela legislação, e em um encontro de pesquisadores sobre hidrelétricas . Foram elencados 335 alvos entre espécies e feições geográficas que potencialmente seriam afetados pelas barragens. A seleção de alvos prioritários foi feita através da sobreposição espacial desses alvos iniciais com todas as barragens construídas e planejadas na região hidrográfica da Amazônia. As análises indicaram que apenas alvos aquáticos foram ameaçados pelas represas e também ficou evidente que a bacia do Tapajós será a mais afetada pela instalação das novas barragens. . Na bacia do Tapajós será feito o maior investimento em construção de novas barragens pela proposta do setor elétrico. No capítulo 3, foi feita uma simulação das combinações de barragens mensurando o potencial hidrelétrico e nos impactos previstos sobre a biodiversidade que cada potencial combinação de empreendimentos poderia causar. Os elementos de biodiversidade usados foram as espécies (p.e Trichechus inuinguis e Brachyplatystoma rousseauxii) e ambientes (p.e. pedrais e rios conectados) selecionados no capítulo 2. Como custo da preservação desses elementos foram considerados a quantidade de energia perdida em Mega Watts(que são as barragens que não poderia ser construída) para que a área não fosse degradada e o alvo pudesse persistir. A análise foi feita através da Fronteira de Pareto, que é uma ferramenta apropriada para comparar dois recursos competitivos. A investigação dessa curva pode mostrar alguns níveis ótimos de utilização de um recurso prejudicando o mínimo possível do uso do outro recurso. Através da fronteira de Pareto alguns pontos encontraram a situação de ganha-ganha, mostrando que pode ser compatível a produção de energia com a preservação ambiental, mas essas melhores combinações não são a proposta atual do governo. A fronteira de Pareto revela que um dos pontos de maior eficiência mostrou que é possível produzir 78% da energia elétrica potencial planejada com uma perda estimada de 21% da biodiversidade em relação à proposta atual do governo. Todos os resultados foram fortemente influenciados pela escolha dos alvos analisados e esses devem ser investigados mais a fundo antes da tomada de decisões sobre hidrelétricas na bacia

LA PRAXIS AFROENSAYÍSTICA DE MANUEL ZAPATA OLIVELLA/ THE AFRO-ESSAY PRAXIS OF MANUEL ZAPATA OLIVELLA

O presente estudio tem como objetivo investigar a práxis afro-ensaística do colombiano Manuel Zapata Olivella (1920-2004). Apartir da analise da antología organizada por Alfonso Múnera intitulada Por los senderos de sus ancestros: textos escogidos- 1940/2000, verificarei como no quefazer ensaístico de Zapata Olivella configura a sua estética e os possivéis desdobramentos na sua ficção. Os postulados teóricos desta pesquisa serão os colocados por Frantz Fanon no clássico Piel negra, máscaras blancas (2009). Além disso, o nacionalismo literário de Zapata Olivella será comparado com outras produções ensaísticas iberoamericanas, como a de Antônio Cândido, por exemplo, levando em consideração seu contexto de enunciação. As profundas mudanças históricas do século XX afetaram o posicionamento da intelectualidade latinoamericana, sobretudo a colombiana, apartir da perspectiva de um olhar e uma voz que reivindica o seu direito à participação no debate artístico o que não acontece na maioria das historiografías literárias tradicionais e que na atualidade é mais necessário do que nunca para os diálogos interculturais entre os países de Latinoamérica.Palavras-chave: Zapata Olivella. Afro-Ensaio. Literatura ColombianaResumenEste estudio tiene como meta investigar la práxis afroensayística del colombiano Manuel Zapata Olivella (1920-2004). A partir del análisis de la antología organizada por Alfonso Múnera intitulada Por los senderos de sus ancestros: textos escogidos- 1940/2000, voy a verificar cómo el quehacer ensayístico de Zapata Olivella configura su estética y cuáles serán los posibles desdoblamientos en su ficción. Los postulados teóricos de susodicha investigación van a ser los planteados por Frantz Fanon en el clásico Piel negra, máscaras blancas (2009). Además, el nacionalismo literario de Zapata Olivella será comparado con otras producciones ensayísticas iberoamericanas, como la de Antônio Cândido, por ejemplo, y teniendo en cuenta su contexto de enunciación. Los profundos cambios históricos del siglo XX afectaron la toma de posición de la intelectualidad latinoamericana, sobre todo la colombiana, a partir de la perspectiva de una mirada y una voz que plantea su derecho a la participación en el debate artístico y que en la mayoría de las historiografías literarias tradicionales no hace parte y que en la actualidad es más necesaria que nunca para los diálogos interculturales de los países de Latinoamérica.Palabras-clave: Zapata Olivella. Afroensayo. Literatura ColombianaAbstractThis study aims to investigate the Colombian afro essays of the Manuel Zapata Olivella (1920-2004). From the analysis of the anthology organized by Alfonso Munera entitled Por los senderos de sus ancestros: textos escogidos- 1940/2000, I will check how the essayistic work of Zapata Olivella set aesthetic and what are the possible splits in his fiction. The aforementioned theoretical postulates of research will be presented by Frantz Fanon in Piel negra, máscaras blancas (2009). In addition, the literary nationalism Zapata Olivella will be compared with other Latin American essayistic productions, such as Antonio Candido, for example, and taking into account its context of enunciation. The profound historical changes of the twentieth century affected the stance of Latin American intellectuals, especially Colombia, from the perspective of a look and a voice that raises their right to participate in the artistic debate and that in most traditional literary historiography not part and today is more necessary than ever for intercultural dialogue in the countries of Latin America.Keywords: Zapata Olivella. Afro Essays. Colombian Literatur