2,257 research outputs found

    Complete chloroplast genome sequence of Holoparasite Cistanche Deserticola (Orobanchaceae) reveals gene loss and horizontal gene transfer from Its host Haloxylon Ammodendron (Chenopodiaceae)

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    The central function of chloroplasts is to carry out photosynthesis, and its gene content and structure are highly conserved across land plants. Parasitic plants, which have reduced photosynthetic ability, suffer gene losses from the chloroplast (cp) genome accompanied by the relaxation of selective constraints. Compared with the rapid rise in the number of cp genome sequences of photosynthetic organisms, there are limited data sets from parasitic plants. The authors report the complete sequence of the cp genome of Cistanche deserticola, a holoparasitic desert species belonging to the family Orobanchaceae

    Salience-based selection: attentional capture by distractors less salient than the target

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    Current accounts of attentional capture predict the most salient stimulus to be invariably selected first. However, existing salience and visual search models assume noise in the map computation or selection process. Consequently, they predict the first selection to be stochastically dependent on salience, implying that attention could even be captured first by the second most salient (instead of the most salient) stimulus in the field. Yet, capture by less salient distractors has not been reported and salience-based selection accounts claim that the distractor has to be more salient in order to capture attention. We tested this prediction using an empirical and modeling approach of the visual search distractor paradigm. For the empirical part, we manipulated salience of target and distractor parametrically and measured reaction time interference when a distractor was present compared to absent. Reaction time interference was strongly correlated with distractor salience relative to the target. Moreover, even distractors less salient than the target captured attention, as measured by reaction time interference and oculomotor capture. In the modeling part, we simulated first selection in the distractor paradigm using behavioral measures of salience and considering the time course of selection including noise. We were able to replicate the result pattern we obtained in the empirical part. We conclude that each salience value follows a specific selection time distribution and attentional capture occurs when the selection time distributions of target and distractor overlap. Hence, selection is stochastic in nature and attentional capture occurs with a certain probability depending on relative salience

    Tres medici, duo athei? The Physician as Atheist and the Medicalization of the Soul

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    Until recently, examinations of the ‘mind-body problem’ in historical context paid only cursory attention to its specifically medical dimension, if at all. At best, some ‘folk physiology’ was entertained, usually to laugh at it (the pineal gland, animal spirits). Conversely, historians of neuroscience or of artificial intelligence (Jeannerod 1985, Dupuy 2000) often present figures like La Mettrie as heroic early cases of ‘naturalization’, giving an experimental basis to materialism: their symmetrically inverse mistake is to take professions of medical authority too literally (although there are genuine cases where all of the above does coalesce – where ‘actors’ categories mysteriously transcend historiographic projections –, such as Hieronymus Gaub’s reflections on the ‘regimen of the mind’ in the mid-eighteenth century, or, more theoretically, Guillaume Lamy’s Epicurean-inflected Anatomical Discourses on the Soul, eighty years earlier). Contrary to the denial of the relevance of medicine in early modern philosophy, as regards issues such as the body-soul (then body-mind) relation among others, it seems patently difficult to separate medical theory, medically nourished philosophical speculation, and metaphysics. This is the case, whether in Descartes, Gaub, the ‘animist’ Georg-Ernest Stahl, or materialists such as Guillaume Lamy and La Mettrie: medicine, or rather ‘a certain idea of medicine’, is everywhere. Here I focus on the motif of a radical medicine – a medical precursor of the Radical Enlightenment (Israel 2001, 2006, 2007), symbolized negatively by the slogan, tres medici, duo athei, or ‘where there are three doctors, there are two atheists’, i.e. medicine as a basis for atheism. This theme runs through various works of medical or medico-theological propaganda: Thomas Browne’s 1643 De religio medici begins with Browne regretting rumors of doctors being atheists as the “general scandal of my Profession”; Germain de Bezançon’s 1677 Les médecins à la censure works hard at rebutting the saying, “Bon Physicien, mauvais chrétien.” But these are examples of the fear of a radical medicine – a medicine that denies the existence of an immortal soul, or even defends materialism and atheism. Are there positive statements of this doctrine? Indeed, attacks on it are much more common than statements identifying with it, like medical versions of natural theology in general. In fact, just as there were theologically motivated medical works, there were also medically motivated works of radical or heretical theology, like William Coward’s Second Thoughts on the Human Soul (Coward 1702, building on Overton 1644), which engaged in polemics concerning the nature of the soul – mortal or immortal? (Thomson 2008). Parallel to the mortalist trend, but flowing into a common genre of radical, medico-materialist texts (sometimes anonymous, such as L’Âme Matérielle, from the 1720s) are at least two other strands of radical medicine: a post-Cartesian focus on medicina mentis and the nature of the mind (Henricus Regius, Hieronymus Gaub, Antoine Le Camus), and an Epicurean medicine, in which mind and body are organismically united, with an additional hedonistic component, notably in Lamy, Mandeville and La Mettrie (Wright 1991, Wolfe and van Esveld 2014). The focus on a medicine of the mind (Corneanu, ms. 2013) is obviously connected to a ‘medicalization of the soul’: there was a body-soul problem in and for medicine, a sort of medicalized ‘pneumatology’. Radical medicine is located somewhere in between the early forms of ‘naturalization’ or ‘medicalization’ of the soul and the pose of scientific neutrality that is characteristic of early nineteenth-century medicine (as in Cabanis, Bichat or Bernard): it is a short-lived episode. I seek to reconstruct this intellectual figure, in which mortalist, post-Cartesian and Epicurean strands intersect and sometimes come together. I suggest that medically influenced materialism in the Radical Enlightenment (e.g. in the later French cases, La Mettrie, Ménuret and Diderot), is different from later, more experimentally focused and more quantitatively oriented forms of medical materialism, precisely because of its radical dimension. This radical medicine often insists on vitality, as opposed to “anatomie cadavérique”: it is vital and hedonistic, a medicine concerned with maintaining bodily pleasure.Until recently, examinations of the 'mind-body problem' in historical context paid only cursory attention to its specifically medical dimension, if at all. At best, some 'folk physiology' was entertained, usually to laugh at it (the pineal gland, animal spirits). Conversely, historians of neuroscience or of artificial intelligence (Jeannerod M, The brain machine. The development of neurophysiological thought, trans. D. Urion, Harvard University Press, Cambridge, 1985; Dupuy J-P, The mechanization of the mind: on the origins of cognitive science, trans. M.B. DeBevoise, Princeton University Press, Princeton, 2000) often present figures like La Mettrie as heroic early cases of 'naturalization', giving an experimental basis to materialism: their symmetrically inverse mistake is to take professions of medical authority too literally (although there are genuine cases where all of the above does coalesce where 'actors' categories mysteriously transcend historiographic projections -, such as Hieronymus Gaub's reflections on the 'regimen of the mind' in the mid-eighteenth century, or, more theoretically, Guillaume Lamy's Epicurean-inflected Anatomical Discourses on the Soul, eighty years earlier). Contrary to the denial of the relevance of medicine in early modern philosophy, as regards issues such as the body-soul (then body-mind) relation among others, it seems patently difficult to separate medical theory, medically nourished philosophical speculation, and metaphysics. This is the case, whether in Descartes, Gaub, the 'animist' Georg-Ernest Stahl, or materialists such as Guillaume Lamy and La Mettrie: medicine, or rather 'a certain idea of medicine', is everywhere.Here I focus on the motif of a radical medicine - a medical precursor of the Radical Enlightenment (Israel J, Radical enlightenment. Philosophy and the making of modernity, 1650-1750, Oxford University Press, Oxford, 2001; Israel J, Enlightenment contested. Oxford University Press, Oxford, 2006, Israel J, Enlightenment, radical enlightenment and the "medical revolution" of the late seventeenth and eighteenth centuries. In: Grell OP, Cunningham A (ed) Medicine and religion in enlightenment Europe. Ashgate, Aldershot, pp 5-28, 2007), symbolized negatively by the slogan, tres medici, duo athei, or 'where there are three doctors, there are two atheists', i.e. medicine as a basis for atheism. This theme runs through various works of medical or medico-theological propaganda: Thomas Browne's 1643 De religio medici begins with Browne regretting rumors of doctors being atheists as the "general scandal of my Profession"; Germain de Bezancon's 1677 Les medecins a la censure works hard at rebutting the saying, "Bon Physicien, mauvais chretien." But these are examples of the fear of a radical medicine - a medicine that denies the existence of an immortal soul, or even defends materialism and atheism. Are there positive statements of this doctrine? Indeed, attacks on it are much more common than statements identifying with it, like medical versions of natural theology in general.In fact, just as there were theologically motivated medical works, there were also medically motivated works of radical or heretical theology, like William Coward's Second Thoughts on the Human Soul (Coward W, Second thoughts on the human soul. R. Basset, London, 1702, building on Overton 1644), which engaged in polemics concerning the nature of the soul - mortal or immortal? (Thomson A, Bodies of thought: science, religion, and the soul in the early enlightenment. Oxford University Press, Oxford, 2008). Parallel to the mortalist trend, but flowing into a common genre of radical, medico-materialist texts (sometimes anonymous, such as L'Ame Materielle, from the 1720s) are at least two other strands of radical medicine: a post-Cartesian focus on medicina mentis and the nature of the mind (Henricus Regius, Hieronymus Gaub, Antoine Le Camus), and an Epicurean medicine, in which mind and body are organismically united, with an additional hedonistic component, notably in Lamy, Mandeville and La Mettrie (Wright JP, Locke, Willis, and the seventeenth-century epicurean soul. In: Osler MJ (ed) Atoms, Pneuma, and Tranquillity: Epicurean and stoic themes in European thought. Cambridge University Press, Cambridge, pp 239-258, 1991; Wolfe CT, van Esveld M, The material soul: strategies for naturalising the soul in an early modern epicurean context. In: Kambaskovic D (ed) Conjunctions: body, soul and mind from Plato to the enlightenment. Springer, Dordrecht, pp 371-421, 2014). The focus on a medicine of the mind (Corneanu, (ms. 2013), The care of the whole man: medicine and theology in the late renaissance, 2013) is obviously connected to a 'medicalization of the soul': there was a body-soul problem in and for medicine, a sort of medicalized 'pneumatology'. Radical medicine is located somewhere in between the early forms of 'naturalization' or 'medicalization' of the soul and the pose of scientific neutrality that is characteristic of early nineteenth-century medicine (as in Cabanis, Bichat or Bernard): it is a short-lived episode. I seek to reconstruct this intellectual figure, in which mortalist, post-Cartesian and Epicurean strands intersect and sometimes come together. I suggest that medically influenced materialism in the Radical Enlightenment (e.g. in the later French cases, La Mettrie, Menuret and Diderot), is different from later, more experimentally focused and more quantitatively oriented forms of medical materialism, precisely because of its radical dimension. This radical medicine often insists on vitality, as opposed to "anatomie cadaverique": it is vital and hedonistic, a medicine concerned with maintaining bodily pleasure

    Habitat structure: a fundamental concept and framework for urban soil ecology

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    Habitat structure is defined as the composition and arrangement of physical matter at a location. Although habitat structure is the physical template underlying ecological patterns and processes, the concept is relatively unappreciated and underdeveloped in ecology. However, it provides a fundamental concept for urban ecology because human activities in urban ecosystems are often targeted toward management of habitat structure. In addition, the concept emphasizes the fine-scale, on-the-ground perspective needed in the study of urban soil ecology. To illustrate this, urban soil ecology research is summarized from the perspective of habitat structure effects. Among the key conclusions emerging from the literature review are: (1) habitat structure provides a unifying theme for multivariate research about urban soil ecology; (2) heterogeneous urban habitat structures influence soil ecological variables in different ways; (3) more research is needed to understand relationships among sociological variables, habitat structure patterns and urban soil ecology. To stimulate urban soil ecology research, a conceptual framework is presented to show the direct and indirect relationships among habitat structure and ecological variables. Because habitat structure serves as a physical link between sociocultural and ecological systems, it can be used as a focus for interdisciplinary and applied research (e.g., pest management) about the multiple, interactive effects of urbanization on the ecology of soils

    Gene transfer: anything goes in plant mitochondria

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    Parasitic plants and their hosts have proven remarkably adept at exchanging fragments of mitochondrial DNA. Two recent studies provide important mechanistic insights into the pattern, process and consequences of horizontal gene transfer, demonstrating that genes can be transferred in large chunks and that gene conversion between foreign and native genes leads to intragenic mosaicism. A model involving duplicative horizontal gene transfer and differential gene conversion is proposed as a hitherto unrecognized source of genetic diversity

    Reliability and validity of a short form household food security scale in a Caribbean community

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    BACKGROUND: We evaluated the reliability and validity of the short form household food security scale in a different setting from the one in which it was developed. METHODS: The scale was interview administered to 531 subjects from 286 households in north central Trinidad in Trinidad and Tobago, West Indies. We evaluated the six items by fitting item response theory models to estimate item thresholds, estimating agreement among respondents in the same households and estimating the slope index of income-related inequality (SII) after adjusting for age, sex and ethnicity. RESULTS: Item-score correlations ranged from 0.52 to 0.79 and Cronbach's alpha was 0.87. Item responses gave within-household correlation coefficients ranging from 0.70 to 0.78. Estimated item thresholds (standard errors) from the Rasch model ranged from -2.027 (0.063) for the 'balanced meal' item to 2.251 (0.116) for the 'hungry' item. The 'balanced meal' item had the lowest threshold in each ethnic group even though there was evidence of differential functioning for this item by ethnicity. Relative thresholds of other items were generally consistent with US data. Estimation of the SII, comparing those at the bottom with those at the top of the income scale, gave relative odds for an affirmative response of 3.77 (95% confidence interval 1.40 to 10.2) for the lowest severity item, and 20.8 (2.67 to 162.5) for highest severity item. Food insecurity was associated with reduced consumption of green vegetables after additionally adjusting for income and education (0.52, 0.28 to 0.96). CONCLUSIONS: The household food security scale gives reliable and valid responses in this setting. Differing relative item thresholds compared with US data do not require alteration to the cut-points for classification of 'food insecurity without hunger' or 'food insecurity with hunger'. The data provide further evidence that re-evaluation of the 'balanced meal' item is required

    Neurolymphomatosis mimicking neurosarcoidosis: a case report

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    <p>Abstract</p> <p>Introduction</p> <p>Both neurosarcoidosis and central nervous system lymphoma can be very difficult to diagnose. We describe the case of a patient in whom neurosarcoidosis was strongly suspected, but who was eventually found to have lymphoma. We believe the case to be of interest and practical value to neurologists, oncologists and internists with an interest in inflammatory diseases.</p> <p>Case presentation</p> <p>A diagnosis of neurosarcoidosis was considered in a 49-year-old Caucasian man on the basis of the following symptoms and indications: a cough, bilateral hilar lymphadenopathy confirmed by thoracic computed tomography, the development of an S1 radiculopathy, cerebrospinal fluid abnormalities (raised protein level), bilateral lung hilar and lachrymal gland uptake on a gallium scan, and erythema nodosum confirmed with skin biopsy. These were followed by the development of multiple cranial neuropathies, including seventh nerve palsy. Exhaustive further investigations yielded no evidence for an alternative diagnosis. Treatments with steroids, cyclophosphamide, intravenous immunoglobulin and finally infliximab were of no benefit. He eventually developed cutaneous nodules, a biopsy of which revealed lymphoma that proved resistant to therapy.</p> <p>Conclusion</p> <p>Constant diagnostic vigilance is required in disorders such as neurosarcoidosis.</p

    Degeneracy: a link between evolvability, robustness and complexity in biological systems

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    A full accounting of biological robustness remains elusive; both in terms of the mechanisms by which robustness is achieved and the forces that have caused robustness to grow over evolutionary time. Although its importance to topics such as ecosystem services and resilience is well recognized, the broader relationship between robustness and evolution is only starting to be fully appreciated. A renewed interest in this relationship has been prompted by evidence that mutational robustness can play a positive role in the discovery of adaptive innovations (evolvability) and evidence of an intimate relationship between robustness and complexity in biology. This paper offers a new perspective on the mechanics of evolution and the origins of complexity, robustness, and evolvability. Here we explore the hypothesis that degeneracy, a partial overlap in the functioning of multi-functional components, plays a central role in the evolution and robustness of complex forms. In support of this hypothesis, we present evidence that degeneracy is a fundamental source of robustness, it is intimately tied to multi-scaled complexity, and it establishes conditions that are necessary for system evolvability

    Parallel evolution of the make–accumulate–consume strategy in Saccharomyces and Dekkera yeasts

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    Saccharomyces yeasts degrade sugars to two-carbon components, in particular ethanol, even in the presence of excess oxygen. This characteristic is called the Crabtree effect and is the background for the 'make–accumulate–consume' life strategy, which in natural habitats helps Saccharomyces yeasts to out-compete other microorganisms. A global promoter rewiring in the Saccharomyces cerevisiae lineage, which occurred around 100 mya, was one of the main molecular events providing the background for evolution of this strategy. Here we show that the Dekkera bruxellensis lineage, which separated from the Saccharomyces yeasts more than 200 mya, also efficiently makes, accumulates and consumes ethanol and acetic acid. Analysis of promoter sequences indicates that both lineages independently underwent a massive loss of a specific cis-regulatory element from dozens of genes associated with respiration, and we show that also in D. bruxellensis this promoter rewiring contributes to the observed Crabtree effect
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