39 research outputs found

    Espaço e Design. Legibilidade é a Habitabilidade, um Apanhado Histórico-Conceptual da Verdadeira Revolução Industrial da Comunicação Impressa.

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    Neste texto é confrontada a temática desta obra com a área da comunicação, na perspetiva de que tudo o que rodeia a cidade contemporânea possui uma dimensão de comunicação e recebe o tratamento estético do real e virtual. Hoje a cidade é um espaço preenchido e ativo cuja observação detalhada revela um território de produção de mensagens contra um território de circulação de signos ou, paralelamente, uma estrutura de significados contra uma estrutura de significantes. Os meios de comunicação analógicos são os principais responsáveis por este preenchimento, por esta massificação e influência no peão que habita a cidade. Numa visão tipográfica, a fórmula deste processo traduz-se na relação entre o kerning, como elemento primordial de segurança na legibilidade de uma palavra, e a projeção de um bairro na cidade. Outro exemplo paralelo, o tracking está para o bloco de texto como a urbanização está para a cidade e o cânone de Van de Graaf equivale-se à planificação do todo na cidade

    Espacio verbal vs no-verbal, el problema de la tipografía

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    Tendo em conta a comunicação, onde será que reside o verdadeiro problema da tipografia, no espaço verbal ou não-verbal? Muitas são as aplicações que tentam desvendar qual terá maior peso, vejamos aqui um exemplo prático do atelier português DSType

    Desenvolvimento larvar da savelha (Alosa fallax): descrição morfológica e influência da temperatura e da salinidade no crescimento

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    Tese de mestrado. Biologia (Pescas e Aquacultura). Universidade de Lisboa, Faculdade de Ciências, 2011The twait shad, Alosa fallax (Lacepède, 1803), is an anadromous clupeid threatened by anthropogenic pressures from changes in the hydrological dynamics of river flow to limited connectivity of inland waters due to damming, among others. Population recovery is intrinsically dependent on the implementation of conservation measures for the rehabilitation of riverine ecosystems. The timely application of direct approaches aimed at strengthening population size may also be beneficial to its recovery. Therefore, the optimization of hatchery efforts is crucial to enable restocking programs. In this study we tested growth and mortality of A. fallax larvae from the Guadiana population reared at different temperature, salinity and feeding conditions. Results indicated that the temperature for optimal growth is somewhere between 24°C and 28°C, and that the optimal salinity for minimizing mortality in aquaculture systems in which the larvae are fed with Artemia spp. nauplii is close to 2,5 g/L. Moreover, the larval development of individuals from the same population reared under controlled conditions was described, from the moment of hatching to the completion of metamorphosis, using morphometric and meristic characters to define a series of larval stages easily identifiable. This study allowed obtaining important insights for the optimization of larval culture of A. fallax, as well as a relevant basis for the identification of larvae captured for recruitment assessments.A savelha, Alosa fallax (Lacepède, 1803), é um clupeídeo anádromo que se encontra ameaçado devido a várias pressões antropogénicas resultantes, essencialmente, da alteração da dinâmica hidrológica fluvial e da conectividade dos cursos de água interiores. A recuperação populacional desta espécie está intrinsecamente dependente da implementação de medidas de conservação visando, em particular, a reabilitação dos ecossistemas ribeirinhos. A aplicação pontual de abordagens dirigidas ao reforço directo dos efectivos populacionais poderá também ser benéfica à recuperação das populações actuais. Nesta perspectiva, a optimização dos esforços de produção larvar é crucial para a viabilização de programas de repovoamento, sendo imprescindível avaliar as condições ideais de cultivo da espécie. Na presente dissertação foi testada a resposta em termos de crescimento e de mortalidade, de larvas da população de A. fallax do Rio Guadiana criadas a diferentes condições de temperatura, salinidade e frequência de alimentação. Os resultados indicam que a temperatura ideal para optimização do crescimento se situa entre 24°C e 28°C, e que a salinidade óptima para minimização da mortalidade em sistemas de aquacultura em que as larvas são alimentadas com nauplii de Artemia spp., ronda os 2,5 g/L. Tendo por base indivíduos da mesma população criados em laboratório sob condições controladas foi ainda descrito o desenvolvimento larvar de A. fallax desde o momento de eclosão até ao final da metamorfose, recorrendo a caracteres morfométricos e merísticos para definição de uma série de estádios larvares facilmente identificáveis. Deste modo, o estudo desenvolvido permitiu obter dados importantes quer para a optimização da larvicultura da savelha quer para a identificação de larvas, aspecto essencial para uma correcta monitorização dos processos de recrutamento

    Characterizing partial AZFc deletions of the Y chromosome with amplicon-specific sequence markers

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    BACKGROUND: The AZFc region of the human Y chromosome is a highly recombinogenic locus containing multi-copy male fertility genes located in repeated DNA blocks (amplicons). These AZFc gene families exhibit slight sequence variations between copies which are considered to have functional relevance. Yet, partial AZFc deletions yield phenotypes ranging from normospermia to azoospermia, thwarting definite conclusions on their real impact on fertility. RESULTS: The amplicon content of partial AZFc deletion products was characterized with novel amplicon-specific sequence markers. Data indicate that partial AZFc deletions are a male infertility risk [odds ratio: 5.6 (95% CI: 1.6–30.1)] and although high diversity of partial deletion products and sequence conversion profiles were recorded, the AZFc marker profiles detected in fertile men were also observed in infertile men. Additionally, the assessment of rearrangement recurrence by Y-lineage analysis indicated that while partial AZFc deletions occurred in highly diverse samples, haplotype diversity was minimal in fertile men sharing identical marker profiles. CONCLUSION: Although partial AZFc deletion products are highly heterogeneous in terms of amplicon content, this plasticity is not sufficient to account for the observed phenotypical variance. The lack of causative association between the deletion of specific gene copies and infertility suggests that AZFc gene content might be part of a multifactorial network, with Y-lineage evolution emerging as a possible phenotype modulator

    The time scale of recombination rate evolution in great apes

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    We present three linkage-disequilibrium (LD)-based recombination maps generated using whole-genome sequence data from 10 Nigerian chimpanzees, 13 bonobos, and 15 western gorillas, collected as part of the Great Ape Genome Project (Prado-Martinez J, et al. 2013. Great ape genetic diversity and population history. Nature 499:471-475). We also identified species-specific recombination hotspots in each group using a modified LDhot framework, which greatly improves statistical power to detect hotspots at varying strengths. We show that fewer hotspots are shared among chimpanzee subspecies than within human populations, further narrowing the time scale of complete hotspot turnover. Further, using species-specific PRDM9 sequences to predict potential binding sites (PBS), we show higher predicted PRDM9 binding in recombination hotspots as compared to matched cold spot regions in multiple great ape species, including at least one chimpanzee subspecies. We found that correlations between broad-scale recombination rates decline more rapidly than nucleotide divergence between species. We also compared the skew of recombination rates at centromeres and telomeres between species and show a skew from chromosome means extending as far as 10-15Mb from chromosome ends. Further, we examined broad-scale recombination rate changes near a translocation in gorillas and found minimal differences as compared to other great ape species perhaps because the coordinates relative to the chromosome ends were unaffected. Finally, on the basis of multiple linear regression analysis, we found that various correlates of recombination rate persist throughout the African great apes including repeats, diversity, and divergence. Our study is the first to analyze within- And between-species genome-wide recombination rate variation in several close relatives

    Pervasive gaps in Amazonian ecological research

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    Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio

    Pervasive gaps in Amazonian ecological research

    Get PDF

    Pervasive gaps in Amazonian ecological research

    Get PDF
    Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost

    Pervasive gaps in Amazonian ecological research

    Get PDF
    Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost
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