10,636 research outputs found

    Assessing the species boundary and ecological niche in freshwater gastropods of the family Physidae (Gastropoda, Hygrophila)

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    The present thesis contributed to increasing the knowledge about the diversity of the neotropical freshwater mollusks. Through the use of different methodologies for analyzing molecular and geographical occurrence data, we address important taxonomic issues and show new paths for future taxonomic research on the Physidae family. This family for a long time had classification proposals based only on morphological characters of the shell and, later, on the anatomy of the soft parts. The application of molecular delimitation methods based on coalescence showed the inadequacy of morphological criteria in discriminating intraspecific variability (overestimating family diversity) and in detecting the existence of cryptic species complexes (underestimating family diversity). The data on the occurrence along with the use of georeferencing tools, modeling, and ecological niche analyses applied to South American physid species, indicated the possibility of errors in species identification and the need to reassess the distribution of these physids using other operational criteria such as molecular approaches to access the actual family diversity and distribution for the continent.A presente tese contribuiu para ampliar o conhecimento sobre a diversidade da malacofauna dulcícola neotropical. Através do emprego de diferentes metodologias de análise de dados moleculares e de ocorrência geográfica abordamos importantes questões taxonômicas e mostramos novos caminhos para futuras pesquisas taxonômicas da família Physidae. Família essa que por muito tempo teve propostas de classificação embasadas apenas em caracteres morfológicos da concha e, posteriormente, na anatomia das partes moles. A aplicação de métodos de delimitação molecular baseados em coalescência, evidenciou a insuficiência dos critérios morfológicos em discriminar a variabilidade intraespecífica (superestimando a diversidade da família) e, em detectar a existência de complexos de espécies crípticas (subestimando a diversidade da família). A abordagem de busca intensiva por dados de ocorrência junto a utilização de ferramentas de georreferenciamento, modelagem e análises de nicho ecológico aplicadas às espécies de fisídeos sul-americanos, indicaram a possibilidade de erros de identificação de espécies e a necessidade de reavaliar a distribuição desses fisídeos usando outros critérios operacionais, incluindo abordagens moleculares, para acessar a diversidade e distribuição reais da família para o continente

    L’Asie du Sud-Est 2023 : bilan, enjeux et perspectives

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    Chaque année, l’Institut de recherche sur l’Asie du Sud-Est contemporaine (IRASEC), basé à Bangkok, mobilise une vingtaine de chercheurs et d’experts pour mieux comprendre l’actualité régionale de ce carrefour économique, culturel et religieux, au cœur de l’Indo-Pacifique. Cette collection permet de suivre au fil des ans l’évolution des grands enjeux contemporains de cette région continentale et archipélagique de plus de 680 millions d’habitants, et d’en comprendre les dynamiques d’intégration régionale et de connectivités avec le reste du monde. L’Asie du Sud-Est 2023 propose une analyse synthétique et détaillée des principaux événements politiques et diplomatiques, ainsi que des évolutions économiques, sociales et environnementales de l’année 2022 dans chacun des onze pays de la région. Ce décryptage est complété pour chaque pays par un focus sur deux personnalités de l’année et une actualité marquante en image. L’ouvrage propose également cinq dossiers thématiques qui abordent des sujets traités à l’échelle régionale sud-est asiatique : les ressorts institutionnels de l’approche de santé intégrée One Health, le vieillissement de la population et sa prise en compte par les politiques publiques, les câbles sous-marins au cœur de la connectivité sud-est asiatique, l’aménagement du bassin du Mékong et ses multiples acteurs, et les enjeux politiques et linguistiques des langues transnationales. Des outils pratiques sont également disponibles : une fiche et une chronologie par pays et un cahier des principaux indicateurs démographiques, sociaux, économiques et environnementaux

    Inference-Time Intervention: Eliciting Truthful Answers from a Language Model

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    We introduce Inference-Time Intervention (ITI), a technique designed to enhance the truthfulness of large language models (LLMs). ITI operates by shifting model activations during inference, following a set of directions across a limited number of attention heads. This intervention significantly improves the performance of LLaMA models on the TruthfulQA benchmark. On an instruction-finetuned LLaMA called Alpaca, ITI improves its truthfulness from 32.5% to 65.1%. We identify a tradeoff between truthfulness and helpfulness and demonstrate how to balance it by tuning the intervention strength. ITI is minimally invasive and computationally inexpensive. Moreover, the technique is data efficient: while approaches like RLHF require extensive annotations, ITI locates truthful directions using only few hundred examples. Our findings suggest that LLMs may have an internal representation of the likelihood of something being true, even as they produce falsehoods on the surface.Comment: code: https://github.com/likenneth/honest_llam

    Consent and the Construction of the Volunteer: Institutional Settings of Experimental Research on Human Beings in Britain during the Cold War

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    This study challenges the primacy of consent in the history of human experimentation and argues that privileging the cultural frameworks adds nuance to our understanding of the construction of the volunteer in the period 1945 to 1970. Historians and bio-ethicists have argued that medical ethics codes have marked out the parameters of using people as subjects in medical scientific research and that the consent of the subjects was fundamental to their status as volunteers. However, the temporality of the creation of medical ethics codes means that they need to be understood within their historical context. That medical ethics codes arose from a specific historical context rather than a concerted and conscious determination to safeguard the well-being of subjects needs to be acknowledged. The British context of human experimentation is under-researched and there has been even less focus on the cultural frameworks within which experiments took place. This study demonstrates, through a close analysis of the Medical Research Council's Common Cold Research Unit (CCRU) and the government's military research facility, the Chemical Defence Experimental Establishment, Porton Down (Porton), that the `volunteer' in human experiments was a subjective entity whose identity was specific to the institution which recruited and made use of the subject. By examining representations of volunteers in the British press, the rhetoric of the government's collectivist agenda becomes evident and this fed into the institutional construction of the volunteer at the CCRU. In contrast, discussions between Porton scientists, staff members, and government officials demonstrate that the use of military personnel in secret chemical warfare experiments was far more complex. Conflicting interests of the military, the government and the scientific imperative affected how the military volunteer was perceived

    Structural diversity of marine anti-freezing proteins, properties and potential applications: a review

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    POCI-01 -145-FEDER-016403Cold-adapted organisms, such as fishes, insects, plants and bacteria produce a group of proteins known as antifreeze proteins (AFPs). The specific functions of AFPs, including thermal hysteresis (TH), ice recrystallization inhibition (IRI), dynamic ice shaping (DIS) and interaction with membranes, attracted significant interest for their incorporation into commercial products. AFPs represent their effects by lowering the water freezing point as well as preventing the growth of ice crystals and recrystallization during frozen storage. The potential of AFPs to modify ice growth results in ice crystal stabilizing over a defined temperature range and inhibiting ice recrystallization, which could minimize drip loss during thawing, improve the quality and increase the shelf-life of frozen products. Most cryopreservation studies using marine-derived AFPs have shown that the addition of AFPs can increase post-thaw viability. Nevertheless, the reduced availability of bulk proteins and the need of biotechnological techniques for industrial production, limit the possible usage in foods. Despite all these drawbacks, relatively small concentrations are enough to show activity, which suggests AFPs as potential food additives in the future. The present work aims to review the results of numerous investigations on marine-derived AFPs and discuss their structure, function, physicochemical properties, purification and potential applications. Graphical Abstract: [Figure not available: see fulltext.].publishersversionpublishe

    Modern Folk Devils

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    The devilish has long been integral to myths, legends, and folklore, firmly located in the relationships between good and evil, and selves and others. But how are ideas of evil constructed in current times and framed by contemporary social discourses? Modern Folk Devils builds on and works with Stanley Cohen’s theory on folk devils and moral panics to discuss the constructions of evil. The authors present an array of case-studies that illustrate how the notion of folk devils nowadays comes into play and animates ideas of otherness and evil throughout the world. Examining current fears and perceived threats, this volume investigates and analyzes how and why these devils are constructed. The chapters discuss how the devilish may take on many different forms: sometimes they exist only as a potential threat, other times they are a single individual or phenomenon or a visible group, such as refugees, technocrats, Roma, hipsters, LGBT groups, and rightwing politicians. Folk devils themselves are also given a voice to offer an essential complementary perspective on how panics become exaggerated, facts distorted, and problems acutely angled.;Bringing together researchers from anthropology, sociology, political studies, ethnology, and criminology, the contributions examine cases from across the world spanning from Europe to Asia and Oceania

    Echinoderms Metabolites: Structure, Functions and Biomedical Perspectives

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    The materials published in the Special Issue reflect the real diversity of echinoderm metabolites and cover most of their specific classes and biomedical potential as antioxidant, antiviral, anticancer, and even anticoagulant preparations. The metabolites include sea urchin naphtoquinoid pigments and their semi-synthetic derivatives, sea cucumber triterpene glycosides, esters of polyhydroxysteroids from starfish, sea urchins free sterols, and sea cucumber fucosylated chondroitin sulfates. This Special Issue, “Echinoderm Metabolites: Structure, Functions, and Biomedical Perspectives”, is a collection of articles about different scientific aspects concerning low molecular weight and biopolymer metabolites from echinoderms, including their isolation and chemical structures, biological activities, biosynthesis and evolution, biological functions, and obtaining of semi-synthetic derivatives of biologically active natural products. This Special Issue includes materials about sea urchin naphtoquinoid pigments and their semi-synthetic derivatives, sea cucumber triterpene glycosides, esters of polyhydroxysteroids from starfish, sea urchin free sterols, and sea cucumber fucosylated chondroitin sulfates
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