9,879 research outputs found

    Using Formal Concept Analysis for Finding the Closest Relatives among a Group of Organisms

    Get PDF
    AbstractThe paperpresents a study on comparing different organisms, which requires their DNA sequences. If one considers a sample of DNA regions, an interesting result can be obtained. By using formal concept analysis a procedure that allows to determine the strongest family among different organisms is proposed. The methodology is explained in this paper

    Chimpanzee Rights: The Philosophers' Brief

    Get PDF
    In December 2013, the Nonhuman Rights Project (NhRP) filed a petition for a common law writ of habeas corpus in the New York State Supreme Court on behalf of Tommy, a chimpanzee living alone in a cage in a shed in rural New York (Barlow, 2017). Under animal welfare laws, Tommy’s owners, the Laverys, were doing nothing illegal by keeping him in those conditions. Nonetheless, the NhRP argued that given the cognitive, social, and emotional capacities of chimpanzees, Tommy’s confinement constituted a profound wrong that demanded remedy by the courts. Soon thereafter, the NhRP filed habeas corpus petitions on behalf of Kiko, another chimpanzee housed alone in Niagara Falls, and Hercules and Leo, two chimpanzees held in research facilities at Stony Brook University. Thus began the legal struggle to move these chimpanzees from captivity to a sanctuary, an effort that has led the NhRP to argue in multiple courts before multiple judges. The central point of contention has been whether Tommy, Kiko, Hercules, and Leo have legal rights. To date, no judge has been willing to issue a writ of habeas corpus on their behalf. Such a ruling would mean that these chimpanzees have rights that confinement might violate. Instead, the judges have argued that chimpanzees cannot be bearers of legal rights because they are not, and cannot be persons. In this book we argue that chimpanzees are persons because they are autonomous

    The evolution of RNA interference system, blue light sensing mechanism and circadian clock in Rhizophagus irregularis give insight on Arbuscular mycorrhizal symbiosis

    Full text link
    La symbiose mycorhizienne arbusculaire (MA) est une association formée par les racines des plantes et les champignons mycorhiziens arbusculaires (CMA). Ces champignons sont les plus anciens symbiotes des plantes et ils sont apparus il y a au moins 460 millions d'années avec l'émergence et l'évolution des plantes terrestres. Les CMA sont également les partenaires symbiotiques des plantes les plus répandus dans les écosystèmes et ils peuvent s’associer avec plus de 80% des espèces de plantes vasculaires. Les CMA appartiennent à une lignée fongique primitive dont la position phylogénétique est encore en débat. Les CMA sont des microorganismes biotrophes obligatoires qui dépendent entièrement du carbone provenant de la photosynthèse des plantes hôtes, autrement dit, les CMA ne peuvent assimiler le carbone qu’on association avec les racines des plantes. En échange, les CMA aident les plantes à absorber divers nutriments essentiels du sol, tels que le phosphore. En effet, les CMA absorbent les nutriments et ils les transportent à travers leurs hyphes jusqu’aux cellules des racines dans lesquelles ils forment une structure appelée arbuscule. L'allocation des nutriments et les voies métaboliques interconnectées entre le champignon et l'hôte ont subi une pression sélective en tant que partenaires symbiotiques. En plus, les hyphes de des CMA agissent comme une niche écologique pour divers microbes du sol tels que les bactéries et les champignons, formant ainsi le pivot de la rhizosphère des racines. La symbiose MA est un élément essentiel pour comprendre la physiologie des plantes ainsi que l'écosystème. Malgré les rôles cruciaux des CMA dans les écosystèmes, leur génétique et leur évolution demeure méconnues. Le système d'interférence de l'ARN (ARNi), le mécanisme de détection de la lumière bleue et l'horloge circadienne sont des mécanismes importants qui sont impliqués dans la régulation de l’expression des gènes chez les champignons. Bien que son rôle reconnu dans la régulation des gènes et la traduction des protéines, en particulier dans la symbiose telle que celle des nématodes, le système ARNi n’a jamais été étudié chez les CMA. Pareil pour le cas du mécanisme de détection de la lumière bleue. Seules quelques études ont montré que la lumière bleue peut affecter la germination des spores et la croissance des hyphes des CMA, cependant son mécanisme n'a pas été décrit. Dans le cas de l’horloge circadienne, même si le rythme circadien est omniprésent chez les champignons et que le rythme diurne de la croissance des hyphes a été reporté dans les CMA dans une étude sur le terrain, le mécanisme demeure méconnu. Le génome et le transcriptome du CMA modèle Rhizophagus irregularis isolat DAOM 197198, étaient publiquement disponibles et ils ont été exploité dans mon projet. L'objectif de ma thèse de doctorat visait donc à étudier l'évolution du système ARNi, du mécanisme de détection de la lumière bleue et de l'horloge circadienne dans le génome de R. irregularis à l'aide d'approches biologiques et bioinformatiques. Les objectifs spécifiques étaient de: 1) déterminer si le système ARNi est conservé dans le génome de R. irregularis et d’analyser les traits évolutifs de ses protéines; 2) décrire le mécanisme de détection de la lumière bleue dans le génome R. irregularis ; 3) étudier le mécanisme circadien fongique dans le génome de R. irregularis. J'ai analysé les données génomiques et transcriptomiques pour rechercher les mécanismes conservés du système ARNi de R. irregularis et de certaines espèces de CMA qui lui sont apparentées. Deux phases du cycle de vie de R. irregularis (la phase de la germination des spores et la phase symbiotique avec des racines) ont été utilisées pour déterminer les profils d'expression des gènes en utilisant la PCR quantitative par transcriptase inverse (qPCR). J'ai identifié des traits évolutifs particuliers dans le système ARNi de R. irregularis, tels que le transfert de gènes horizontal (HGT) d’un gène important codant la protéine ribonucléase III, d’origine des cyanobactéries qui n’a jamais été observé chez aucun eucaryote. J'ai également trouvé et identifié un ancien mécanisme de détection de la lumière bleue corrélé à l'horloge circadienne. J’ai trouvé que le gène frequency est conservé dans le génome R. irregularis et que son expression est influencée par l’exposition à la lumière bleue. Ce qui est intéressant est que la protéine la plus importante de l’horloge circadienne (FRQ) n’a jamais été retrouvée dans d’autres lignées primitives fongiques, y compris chez Mucoromycotina, un sous-embranchement fongique considéré comme le plus proche des CMA. Les résultats de mon projet de doctorat a significativement contribuer à la progression de nos connaissances sur les mécanismes importants qui régulent l’expression des gènes chez les CMA qui sont des partenaires symbiotiques des racines des plantes et les plus anciens et les plus répandus dans les écosystèmes. Mes résultats apportent également de nouvelles informations sur le transfert des gènes entre les cyanobactéries et les CMA, et ils ont élargi les connaissances de l'évolution du gène frq chez les champignons. De plus, la présence de gène frq dans le génome de R. irregularis ouvre la voie à l’étude de la chronologique de la symbiose MA, qui peut être le modèle intéressant d’holobiontes des plantes.Arbuscular mycorrhizal (AM) symbiosis is formed by plant roots and arbuscular mycorrhizal fungi (AMF) which are the oldest symbiotic partners of plants and have evolved at least 460 million years ago with the emergence and evolution of land plants. AMF are also the most ubiquitous symbiotic partner of plants as they can colonize more than 80% of vascular plant species. AMF are an early diverged fungal lineage whose phylogenetic position is still under debate. AMF are obligatory plant root symbionts which depend on a source of carbon from the photosynthesis of host plants. In exchange, AMF help plants to absorb various essential soil nutrients, such as phosphorus and transfer these nutrients through their hyphae which have grown into and colonized plant root cells in which they form a structure called an arbuscule. The nutrient allocation and interlocked metabolic pathways between the fungus and the host underwent selective pressure as symbiotic partners. Moreover, AMF hyphae act as an ecological niche for various soil bacteria and other fungi, thus forming the backbone of the rhizospheric part of the plant. AM symbiosis is an essential element to understand plant physiology and ecosystem. Despite the crucial roles of AMF in ecosystems, their genetics and evolution are far from being understood. The RNA interference (RNAi) system, the blue light sensing mechanism and the circadian clock are important mechanisms which regulate expression of various genes in fungi. Although it has an acknowledged role in gene regulation, especially with symbiosis as well as reflected selective pressures on core proteins in the cases of other symbiotic organisms such as nematode worms, the RNAi system has never been considered in AMF. The same is true for the case of blue light sensing mechanisms. Only a few studies showed that blue light can affect spore germination and hyphae growth of AMF, but the mechanism was not addressed. In the case of the circadian clock, even though circadian rhythms are ubiquitous in fungi and a diurnal rhythm of hyphae growth was reported in AMF during a field level study, the mechanism was unknown. Currently, the genome and transcriptome of the model AM fungus Rhizophagus irregularis isolate DAOM 197198, are publicly available and they were used in my studies. The objective of my Ph.D. project was therefore to study the evolution of the RNAi system, blue light sensing mechanisms and the circadian clock in R. irregularis genome using both bioinformatic and molecular biological approaches. The specific objectives of my Ph.D. project were: 1) to investigate whether the RNAi system is conserved in the genome of R. irregularis and explore the evolutionary traits in its core proteins; 2) to describe the blue light sensing mechanism in the genome of R. irregularis; and 3) to search for a fungal circadian mechanism in the genome of R. irregularis. I surveyed genomic and transcriptomic data to search for conserved elements of the RNAi system of R. irregularis and its relatives. Two life stages of the R. irregularis lifecycle (germination of spores without roots and established mycorrhizal symbiosis) were investigated for gene expressional profiles using reverse-transcriptase quantitative PCR (qPCR). I identified particular evolutionary traits in R. irregularis RNAi system, such as horizontal gene transfer (HGT) of its core gene coding ribonuclease III protein from autotrophic cyanobacteria, which has never been reported in any eukaryotes so far. I also found and identified an ancient mechanism of blue light sensing which is related to circadian clock. It was intriguing to find a conserved core gene (frequency) that responds to light exposure in the genome of this underground plant-root symbiont. At the same time, the circadian clock core component (FRQ) was not found in other basal fungal lineages including Mucoromycotina, a fungal subphylum which is considered as the closest relative of AMF. The outcome of my Ph.D. project advanced our knowledge on important mechanisms which regulate the expression of various genes in the oldest and most ubiquitous symbiotic partner of plants. My results also provide new insight on the intimacy between cyanobacteria and AMF which resulted in a unique HGT in the RNAi system. It also expands the knowledge of evolution of the circadian frq gene in fungi. Furthermore, the presence of circadian clock and output genes in R. irregularis opens the door to the chronological study of AM symbiosis, which can be used as a model for the plant holobiont

    Placing Birds On A Dynamic Evolutionary Map: Using Digital Tools To Update The Evolutionary Metaphor Of The Tree Of Life

    Get PDF
    This dissertation describes and presents a new type of interactive visualization for communicating about evolutionary biology, the dynamic evolutionary map. This web-based tool utilizes a novel map-based metaphor to visualize evolution, rather than the traditional tree of life. The dissertation begins with an analysis of the conceptual affordances of the traditional tree of life as the dominant metaphor for evolution. Next, theories from digital media, visualization, and cognitive science research are synthesized to support the assertion that digital media tools can extend the types of visual metaphors we use in science communication in order to overcome conceptual limitations of traditional metaphors. These theories are then applied to a specific problem of science communication, resulting in the dynamic evolutionary map. Metaphor is a crucial part of scientific communication, and metaphor-based scientific visualizations, models, and analogies play a profound role in shaping our ideas about the world around us. Users of the dynamic evolutionary map interact with evolution in two ways: by observing the diversification of bird orders over time and by examining the evidence for avian evolution at several places in evolutionary history. By combining these two types of interaction with a non-traditional map metaphor, evolution is framed in a novel way that supplements traditional metaphors for communicating about evolution. This reframing in turn suggests new conceptual affordances to users who are learning about evolution. Empirical testing of the dynamic evolutionary map by biology novices suggests that this approach is successful in communicating evolution differently than in existing tree-based visualization methods. Results of evaluation of the map by biology experts suggest possibilities for future enhancement and testing of this visualization that would help refine these successes. This dissertation represents an important step forward in the synthesis of scientific, design, and metaphor theory, as applied to a specific problem of science communication. The dynamic evolutionary map demonstrates that these theories can be used to guide the construction of a visualization for communicating a scientific concept in a way that is both novel and grounded in theory. There are several potential applications in the fields of informal science education, formal education, and evolutionary biology for the visualization created in this dissertation. Moreover, the approach suggested in this dissertation can potentially be extended into other areas of science and science communication. By placing birds onto the dynamic evolutionary map, this dissertation points to a way forward for visualizing science communication in the futur

    Social bonding and nurture kinship: compatibility between cultural and biological approaches

    Get PDF
    The current thesis aims to clarify some aspects of the relationship between biology and social bonds. The central task is to demonstrate that, despite clear problems of some past approaches claiming to represent biology, there is non-reductive compatibility between the perspective from cultural approaches documenting processes of social bonding in humans and the perspective from basic biological theory. In demonstrating this compatibility, the thesis also attempts to contribute to delineating the utility and limits of applying insights from biology to understanding aspects of human social behaviour, and to sociological study in general. The areas of social bonding and social relationships under focus are mainly at the level of individuals and primary social groups, rather than a structural-functional approach often employed in classical sociology of the family and comparative sociology. The thesis initially reviews recent cultural approaches to understanding social bonding, and notes the potential academic value of a clarification of the association between social kinship and physical ('related by blood') kinship. In reviewing biological theory on social bonding and social behaviour, it is argued that classic sociobiological interpretations of this biological theory are erroneous in some crucial respects, and a different interpretation is argued for. Evidence on processes mediating social bonding in social mammals and particularly in primates is reviewed. It is demonstrated that circumstantial, social and contextual 'cues' typically mediate the formation of primary social bonds in these species, not genealogical relationship per se, and that these findings are compatible with basic sociological theory. In the human case, it is demonstrated that the current interpretation of biological theory is also compatible with established disciplines closely associated with detailing mechanisms of social bonding (such as attachment theory). The consensus here is again that social bonds are mediated by various social and contextual cues rather than genealogical relationship per se. Contemporary cultural approaches to describing processes of social bonding are investigated and found to be also compatible with the present interpretation of biological theory. With this basic compatibility demonstrated, the possible implications for analyses of patterns of social bonding in human societies is discussed. Delineating the scope of the biological perspective underlines the importance of analysing sociological and cultural influences on patterns of social bonding, including historical, economic and political factors. This is illustrated with some examples

    Distal communication by chimpanzees (Pan troglodytes): evidence for common ground?

    Get PDF
    van der Goot et al. (2014) proposed that distal, deictic communication indexed the appreciation of the psychological state of a common ground between a signaler and a receiver. In their study, great apes did not signal distally, which they construed as evidence for the human uniqueness of a sense of common ground. This study exposed 166 chimpanzees to food and an experimenter, at an angular displacement, to ask, “Do chimpanzees display distal communication?” Apes were categorized as (a) proximal or (b) distal signalers on each of four trials. The number of chimpanzees who communicated proximally did not statistically differ from the number who signaled distally. Therefore, contrary to the claim by van der Goot et al., apes do communicate distally

    Combining Interactomes from Multiple Organisms: a Case Study on Human-Mouse

    Get PDF
    The amount and quality of available data on different organisms varies greatly. While model organisms benefit from extensive experimental studies, there is often a lack of detailed experimental data for more specific organisms. Additionally, even among model organisms there are noticeable differences in the amount and type of data available, due to the different suitability of experiments in different organisms. The combination of interactomes for closely related species, represents a viable tool to increase the amount of protein- protein interaction data for a given organism. The Human-Mouse case of study is particularly relevant, as many experiments cannot be carried out on humans. This paper describes a general method to construct a combined interactome from different organisms.CONACYT – Consejo Nacional de Ciencia y TecnologíaPROCIENCI

    Volume 1, Chapter 2-1: Meet the Bryophytes

    Get PDF
    https://digitalcommons.mtu.edu/bryo-ecol-subchapters/1001/thumbnail.jp
    • …
    corecore