1,582 research outputs found

    Numerical calculation of the transonic potential flow past a cranked wing

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    The widely transonic swept-wing code, FL022, was found to have an error in the transformed flow equation in the computational domain. The revised version of the code correctly accounted for the non-straight leading edge geometry and its effect on the pressure distribution

    A Symbiotic View Of Life: We Have Never Been Individuals

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    The notion of the biological individual is crucial to studies of genetics, immunology, evolution, development, anatomy, and physiology. Each of these biological subdisciplines has a specific conception of individuality, which has historically provided conceptual contexts for integrating newly acquired data. During the past decade, nucleic acid analysis, especially genomic sequencing and high-throughput RNA techniques, has challenged each of these disciplinary definitions by finding significant interactions of animals and plants with symbiotic microorganisms that disrupt the boundaries that heretofore had characterized the biological individual. Animals cannot be considered individuals by anatomical or physiological criteria because a diversity of symbionts are both present and functional in completing metabolic pathways and serving other physiological functions. Similarly, these new studies have shown that animal development is incomplete without symbionts. Symbionts also constitute a second mode of genetic inheritance, providing selectable genetic variation for natural selection. The immune system also develops, in part, in dialogue with symbionts and thereby functions as a mechanism for integrating microbes into the animal-cell community. Recognizing the holobiont -the multicellular eukaryote plus its colonies of persistent symbionts-as a critically important unit of anatomy, development, physiology, immunology, and evolution opens up new investigative avenues and conceptually challenges the ways in which the biological subdisciplines have heretofore characterized living entities

    From the immune self to moral agency. Comments

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    Author comments on the changes in the philosophy of immunology that have occurred since the publication of his book The Immune Self: Theory or Metaphor?, as well as on the dangers, misunderstandings and expectations in this area. Finally, he presents his account of moral agency in the context of his own works discussing this question

    Od immunologicznego „ja” do działania moralnego. Komentarze

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    [Przekład] Autor komentuje zmiany w filozofii immunologii, które zaszły od czasu opublikowania jego książki The Immune Self: Theory or Metaphor?, a także istniejące w tej dziedzinie zagrożenia, nieporozumienia i oczekiwania. Wreszcie – przedstawia w tym kontekście własne ujęcie działania moralnego, odnosząc się do własnych prac

    Immunity in context: science and society in dialogue

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    Según el paradigma dominante en inmunología, la inmunidad está basada en la discriminación entre yo/no-yo y requiere, por tanto, una construcción de la identidad. Dos orientaciones compiten por dominar: la concepción original, concebida en el contexto de las enfermedades infecciosas contempla al organismo como aislado y autónomo, como una entidad que necesita defender sus fronteras. Una visión alternativa sitúa firmemente al organismo en su entorno, en el cual suceden tanto encuentros beneficiosos como costosos. En este enfoque relacional, la tolerancia activa permite relaciones cooperativas con otros organismos en una economía ecológica más amplia. Estas orientaciones en liza —una derivada de la biomedicina y otra de las ciencias ecológicas— han llamado la atención de los científicos sociales y de los críticos de la cultura. Por una parte, el feminismo ha descrito la teoría inmunológica como basada en nociones sociales prestadas de identidad que reflejan los valores agresivos del macho y que, de este modo, impiden una explicación más equilibrada de la inmunidad. Por otra parte, otro comentario proyecta la teoría inmunológica como un marco en el que el análisis de las sociedades occidentales revela aparentemente patrones análogos de interacciones ‘yo’ y ‘otros’, en las que la autoinmunidad y la inmunización son entendidas como expresiones de la comprensión insular de la identidad. Se ofrece aquí una meta-representación que muestra cómo estas críticas sitúan al yo inmune en un espectro que va desde su formulación como un agente autónomo, una concepción modernista del individuo independiente, a una visión postmoderna en la que esta concepción de la identidad ha sido deconstruida. De acuerdo con esto, la inmunología recoge un amplio debate sobre la agencia en el que diferentes interpretaciones de la inmunidad sirven como molde en el que se modelan comprensiones competidoras de la comprensión de las relaciones sociales humanas.; Without disputing the richness of the original incarnation of the immune self – conceived in segregated terms and defended by immunity – this useful heuristic is undergoing transformation. A relational or dialectical orientation has supplemented this incarnation of selfhood from an exclusive focus on the defensive scenario to one that now accommodates more expansive ecological intercourse, one in which active tolerance allows for cooperative exchanges within both the internal and external environments. This revision that emphasizes communal relationships finds support in the social matrix. Just as the autonomous immune self found its own conceptual coordinates in modernist notions of personal identity, changing cultural values, revised notions of personal identity, and the vast growth of ecological awareness resonate with shifts in theorizing about immunity. Such correspondence highlights the ready movement of potent metaphors between the laboratory and its supporting culture

    The Triumph of Uncertainty

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    Tauber, a leading figure in history and philosophy of science, offers a unique autobiographical overview of how science as a discipline of thought has been characterized by philosophers and historians over the past century. He frames his account through science’s – and his own personal – quest for explanatory certainty. During the 20th century, that goal was displaced by the probabilistic epistemologies required to characterize complex systems, whether in physics, biology, economics, or the social sciences. This “triumph of uncertainty” is the inevitable outcome of irreducible chance and indeterminate causality. And beyond these epistemological limits, the interpretative faculties of the individual scientist (what Michael Polanyi called the “personal” and the “tacit”) invariably affects how data are understood. Whereas positivism had claimed radical objectivity, post-positivists have identified how a web of non-epistemic values and social forces profoundly influence the production of knowledge. Tauber presents a case study of these claims by showing how immunology has incorporated extra-curricular social elements in its theoretical development and how these in turn have influenced interpretive problems swirling around biological identity, individuality, and cognition. The correspondence between contemporary immunology and cultural notions of selfhood are strong and striking. Just as uncertainty haunts science, so too does it hover over current constructions of personal identity, self knowledge, and moral agency. Across the chasm of uncertainty, science and selfhood speak

    General relativistic spinning fluids with a modified projection tensor

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    An energy-momentum tensor for general relativistic spinning fluids compatible with Tulczyjew-type supplementary condition is derived from the variation of a general Lagrangian with unspecified explicit form. This tensor is the sum of a term containing the Belinfante-Rosenfeld tensor and a modified perfect-fluid energy-momentum tensor in which the four-velocity is replaced by a unit four-vector in the direction of fluid momentum. The equations of motion are obtained and it is shown that they admit a Friedmann-Robertson-Walker space-time as a solution.Comment: Submitted to General Relativity and Gravitatio

    A Search for Small-Scale Clumpiness in Dense Cores of Molecular Clouds

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    We have analyzed HCN(1-0) and CS(2-1) line profiles obtained with high signal-to-noise ratios toward distinct positions in three selected objects in order to search for small-scale structure in molecular cloud cores associated with regions of high-mass star formation. In some cases, ripples were detected in the line profiles, which could be due to the presence of a large number of unresolved small clumps in the telescope beam. The number of clumps for regions with linear scales of ~0.2-0.5 pc is determined using an analytical model and detailed calculations for a clumpy cloud model; this number varies in the range: ~2 10^4-3 10^5, depending on the source. The clump densities range from ~3 10^5-10^6 cm^{-3}, and the sizes and volume filling factors of the clumps are ~(1-3) 10^{-3} pc and ~0.03-0.12. The clumps are surrounded by inter-clump gas with densities not lower than ~(2-7) 10^4 cm^{-3}. The internal thermal energy of the gas in the model clumps is much higher than their gravitational energy. Their mean lifetimes can depend on the inter-clump collisional rates, and vary in the range ~10^4-10^5 yr. These structures are probably connected with density fluctuations due to turbulence in high-mass star-forming regions.Comment: 23 pages including 4 figures and 4 table

    Development Of The Extraction Method Of Inactive Forms Of Pectin Substances From Fruits To Easy-digestible Active Form During The Obtaining Of Nanofood

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    The aim of the work is development of a unique method for deep processing of fruits and vegetables with a high content of sparingly soluble pectin substances, which makes it possible to remove pectic substances from inactive form and transform them into an easily digestible active form when obtaining natural semi-finished products and food products in nanosized form. To achieve the aim, a complex effect on the raw material of steam-thermal treatment or cryogenic shock freezing and fine-dispersed grinding is used as an innovation.A new method for obtaining finely dispersed additives and health products from fruits and vegetables with a high content of biologically active substances (BAS) and prebiotic substances is developed, which is based on a complex effect on raw materials of processes of steam-thermal or cryogenic treatment of raw materials and fine-dispersed grinding, which is accompanied by destruction, mechanochemistry, non-enzymatic catalysis. It is found that when these processes are activated, pectic substances are activated, more complete extraction from raw materials (4.5 ... 7.3 times) from a latent form and transformation into a soluble form. The mechanism of these processes is disclosed, recommendations for the creation of recreational nanoproducts are developed. It is shown that, in parallel, non-enzymatic catalysis (up to 70%) of hardly soluble pectic substances in individual monomers takes place, that is, transformation into a soluble, easily digestible form.The increase and seizures of latent forms of biologically active substances in finely dispersed frozen and heat-treated purees from fruit compared with fresh raw materials is established. The increase is respectively 1.5 ... 4.0 times and 1.5 ... 3.0 times. The quality of the obtained new types of fine mashed potatoes exceeds the known analogs for BAS content and technological characteristics. New types of purees are in a nanoscale, easily digestible form.With the use of new types of finely dispersed additives, a wide range of products for health-improving nutrition has been developed with a record content of natural BASs (new types of nano-lipids, nanosorb products, milk-vegetable cocktails, fillings for confectionery and extruded products, curd desserts, bakery products, snacks - falafel, creams, etc.)
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