51 research outputs found

    Memory encoding of stimulus features in human perceptual learning

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    Two experiments analyzed memory encoding in human perceptual learning. Both experiments started with preexposure without feedback to four checkerboards composed by a unique feature each and sharing a common feature (AX, BX, CX and DX). Elements of one pair were presented intermixed and elements of the other pair were presented in separate blocks. Immediately after preexposure participants completed a memory recognition task in which the characteristics of the distractors were manipulated. Experiment 1 showed that only intermixed presentation results in good encoding of the unique features of the stimuli. Experiment 2 demonstrated that intermixed preexposure results in different encoding of unique vs. common features of the stimuli: Participants are able to remember A and B better then they remember X, while for the blocked condition memory for C, D and X does not differ. Overall, the results presented here support the proposal that intermixing stimuli results in differential memory traces for unique vs. common features and that contributes to the intermixed/blocked effect.The work reported here was included in a Masters’ dissertation submitted by the first author to the University of Minho, Portugal. Research supported in part by a Multi-Year Funding Program from the Portuguese Foundation for Science and Technology (FCT). Manuscript preparation was supported in part by a Fulbright Research Fellowship to the first author

    Artesãos, cartografia e império. A produção social de um instrumento náutico no mundo ibérico, 1500-1650

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    Explicar cómo y en qué condiciones fueron construidos algunos de los instrumentos científicos más emblemáticos del mundo moderno sigue siendo un desafío para los historiadores de la ciencia y de la tecnología. Este principio afecta también a los instrumentos náuticos. Así, el objetivo del presente artículo es considerar el “cómo” y el “en qué condiciones”, en un sentido amplio, analizando uno de estos artefactos: las cartas náuticas construidas durante la expansión marítima europea. Originalidad: La originalidad del texto no reside únicamente en llevar a cabo una reconstrucción de este instrumento en Portugal y España que aporte nuevos datos sobre su proceso de fabricación y sus fabricantes, sino también en arrojar luz sobre antiguos debates historiográficos que subyacen a la génesis de la ciencia moderna, tales como la difícil colaboración entre hombres prácticos y hombres teóricos; la aportación de comunidades de artesanos al mundo del conocimiento; el papel que los saberes prácticos tuvieron en el establecimiento de nuevas formas de estandarización en ciencia; la adopción de una metodología empírica para el dominio del mundo o la construcción de grandes imperios globales cimentados sobre la base del trabajo manual. Metodología: El análisis de estos debates requiere una aproximación metodológica que atienda a las categorías y los conceptos principales puestos en circulación tanto por la historia como por la filosofía de la ciencia más reciente. En definitiva, se trata de atender a las condiciones que permitieron el establecimiento de acuerdos (y también de controversias) epistemológicos entre diferentes comunidades de conocimiento tomando un instrumento náutico como “mediador”. Conclusiones: El artículo concluye que la consideración de las culturas empíricas del conocimiento y sus realizaciones materiales son una condición sine qua non para entender la génesis de la modernidad científica europea y la construcción de un mundo globalExplaining how and under what conditions some of the most emblematic scientific instruments of the modern world were built remains a challenge for historians of science and technology. This principle also affects nautical instruments. Thus, the objective of this article is to consider the “how” and the “under what conditions”, in a broad sense, by examining one of these devices: the nautical charts developed during the European maritime expansion. Originality: The originality of this article lies not only in the reconstruction of this instrument in Portugal and Spain, providing new information about its development process and its manufacturers, but also in shedding light on old historiographical debates that underlie the genesis of modern science, such as the difficult collaboration between practical men and theoretical men; the contribution of artisan communities to the world of knowledge; the role that practical knowledge played in the establishment of new forms of standardization in science; the adoption of an empirical methodology for achieving mastery of the world or the construction of large global empires founded upon manual labor. Methodology: Analyzing these debates requires a methodological approach that addresses the main categories and concepts put into circulation by the most recent history and philosophy of science. In short, unveiling the conditions that enabled the establishment of epistemological agreements (and also disputes) between different knowledge communities by taking a nautical instrument as “mediator.” Conclusions: The article concludes that examining empirical knowledge cultures and their material achievements are a sine qua non condition to understand the genesis of European scientific modernity and the construction of a global worldExplicar como e em que condições foram construídos alguns dos instrumentos científicos mais emblemáticos do mundo moderno continua sendo um desafio para os historiadores da ciência e da tecnologia. Esse princípio afeta também os instrumentos náuticos. Assim, o objetivo do presente artigo é considerar o “como” e o “em que condições”, em um sentido amplo, e analisar um desses artefatos: as cartas náuticas construídas durante a expansão marítima europeia. Originalidade: A originalidade do texto não reside unicamente na realização de uma reconstrução desse instrumento em Portugal e na Espanha de forma que traga novos dados sobre seu processo de fabricação e de seus fabricantes, mas também em lançar luz sobre antigos debates historiográficos que subjazem à gênese da ciência moderna, tais como a difícil colaboração entre homens práticos e homens teóricos, a contribuição de comunidades de artesãos ao mundo do conhecimento; o papel que os saberes práticos tiveram no estabelecimento de novas formas de padronização na ciência, a adoção de uma metodologia empírica para o domínio do mundo ou a construção de grandes impérios globais cimentados sobre a base do trabalho manual. Metodologia: A análise desses debates requer uma aproximação metodológica que atenda às categorias e aos principais conceitos colocados em circulação tanto pela história quanto pela filosofia da ciência mais recente. Definitivamente, trata-se de atender às condições que permitiram o estabelecimento de acordos (e também de controvérsias) epistemológicos entre diferentes comunidades de conhecimento tomando o instrumento náutico como “mediador”. Conclusões: O artigo conclui que a consideração das culturas empíricas do conhecimento e suas realizações materiais são uma condição sine qua non para entender a gênese da modernidade científica europeia e a construção de um mundo globa

    Pervasive gaps in Amazonian ecological research

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    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

    Mitochondrial physiology

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    As the knowledge base and importance of mitochondrial physiology to evolution, health and disease expands, the necessity for harmonizing the terminology concerning mitochondrial respiratory states and rates has become increasingly apparent. The chemiosmotic theory establishes the mechanism of energy transformation and coupling in oxidative phosphorylation. The unifying concept of the protonmotive force provides the framework for developing a consistent theoretical foundation of mitochondrial physiology and bioenergetics. We follow the latest SI guidelines and those of the International Union of Pure and Applied Chemistry (IUPAC) on terminology in physical chemistry, extended by considerations of open systems and thermodynamics of irreversible processes. The concept-driven constructive terminology incorporates the meaning of each quantity and aligns concepts and symbols with the nomenclature of classical bioenergetics. We endeavour to provide a balanced view of mitochondrial respiratory control and a critical discussion on reporting data of mitochondrial respiration in terms of metabolic flows and fluxes. Uniform standards for evaluation of respiratory states and rates will ultimately contribute to reproducibility between laboratories and thus support the development of data repositories of mitochondrial respiratory function in species, tissues, and cells. Clarity of concept and consistency of nomenclature facilitate effective transdisciplinary communication, education, and ultimately further discovery

    Mitochondrial physiology

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    As the knowledge base and importance of mitochondrial physiology to evolution, health and disease expands, the necessity for harmonizing the terminology concerning mitochondrial respiratory states and rates has become increasingly apparent. The chemiosmotic theory establishes the mechanism of energy transformation and coupling in oxidative phosphorylation. The unifying concept of the protonmotive force provides the framework for developing a consistent theoretical foundation of mitochondrial physiology and bioenergetics. We follow the latest SI guidelines and those of the International Union of Pure and Applied Chemistry (IUPAC) on terminology in physical chemistry, extended by considerations of open systems and thermodynamics of irreversible processes. The concept-driven constructive terminology incorporates the meaning of each quantity and aligns concepts and symbols with the nomenclature of classical bioenergetics. We endeavour to provide a balanced view of mitochondrial respiratory control and a critical discussion on reporting data of mitochondrial respiration in terms of metabolic flows and fluxes. Uniform standards for evaluation of respiratory states and rates will ultimately contribute to reproducibility between laboratories and thus support the development of data repositories of mitochondrial respiratory function in species, tissues, and cells. Clarity of concept and consistency of nomenclature facilitate effective transdisciplinary communication, education, and ultimately further discovery

    Large expert-curated database for benchmarking document similarity detection in biomedical literature search

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    Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe

    Memória e esquecimento: narrativa sobre imperador romano e senado

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