627 research outputs found

    The Ithaca Interpretation of Quantum Mechanics

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    I list several strong requirements for what I would consider a sensible interpretation of quantum mechanics and I discuss two simple theorems. One, as far as I know, is new; the other was only noted a few years ago. Both have important implications for such a sensible interpretation. My talk will not clear everything up; indeed, you may conclude that it has not cleared anything up. But I hope it will provide a different perspective from which to view some old and vexing puzzles (or, if you believe nothing needs to be cleared up, some ancient verities.)Comment: 21 pages, plain TEX. Notes for a lecture given at the Golden Jubilee Workshop on Foundations of Quantum Theory, Tata Institute, Bombay, September 9-12, 199

    Construction and Evaluation of Scenarios as a Learning Strategy through Modelling-Simulation

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    [EN] From a systemic perspective and in the context of an increasing generalization in the use of new technologies and the change in the educational paradigm -which emphasizes guided and autonomous learning-, the learning strategy should be routed to join logical reasoning and instrumental skills (software). The inclusion of new computing and communication resources to the learning process turns them into teaching tools, which makes it possible to organize the teaching and learning process in a different way. The design of these new scenarios of study has important implications to the way information is processed, to the different levels of learning (descriptive, explanatory or analytical ones) and to the way knowledge is acquired and evaluated. In addition, that design takes into account the greater student-content, student-student and student-teacher interactivities, always emphasizing guided independent learning. Thus, the construction, analysis and evaluation of scenarios through models and simulation are the strategy that best suits the current learning style followed by students.Peñaloza Figueroa, JL.; Vargas Perez, C. (2015). Construction and Evaluation of Scenarios as a Learning Strategy through Modelling-Simulation. Multidisciplinary Journal for Education, Social and Technological Sciences. 2(1):40-62. doi:10.4995/muse.2015.2245.SWORD40622

    Overview of the fifth international conference on the effects of noise on aquatic life

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    The Effects of Noise on Aquatic Life took place in Den Haag, the Netherlands, in July 2019. The potential effects on animals ranging from plankton, shrimps, crabs, and lobsters, to fishes, seals, dolphins, and whales were discussed. Reported effects include behavioral responses, auditory masking, cardiac rate changes, stress, a temporary loss of hearing, and perhaps more serious tissue and organ damage. Short-term and long-term, individual and population-level effects were portrayed. Several studies also looked at the fundamentals of animal sound production and perception. One session dealt with the regulation and management of underwater noise. Another integral part of the meeting focused on the sounds and sound sources that might affect aquatic life. As a consequence, underwater noise from pile driving, seismic surveying, shipping, and sonars, as well as from non-anthropogenic sources such as wind and waves was examined. The social program was intended to encourage more leisurely discussions amongst conference participants in order to facilitate networking and the strengthening of relationships. The feedback from conference delegates (submitted via an online survey after the meeting) was very positive

    Towards a higher plane of air transportation security: from hubris to knowledge

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    Security—in air transportation is an issue of global importance. Since September 11, 2001 there have been numerous events where terrorists have successfully exploited vulnerabilities and weakness in the security system. The authors, both security practitioners and academics—contribute to the discussion of what security in air transportation means—by proposing that the existing system still remains vulnerable to future exploitation by terrorists and other threat groups. The essay proffers a framing device. The meaning of security is considered in terms of our knowledge of the system. It considers air transportation security from the position that our knowledge and understanding is limited by hubris; and explains how this can be improved so that system vulnerabilities are revealed and mitigated against before they are exploited. The essay concerns itself with the notion that air transportation security has a multitude of meanings, and that the system is in a critical state because it is perpetually reliant upon sophisticated technologies to retrospectively plug gaps in the defences. The essay concludes that complexity and hubris create a malign condition—which is not visible to lawmakers, regulators and system designers. And, to improve our understanding of what effective security means we need to look behind the hubristic curtain and grapple with the complexities and vagaries, which are the ingredients to the creation and incubation of system vulnerability and weakness

    Unsharp Quantum Reality

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    The positive operator (valued) measures (POMs) allow one to generalize the notion of observable beyond the traditional one based on projection valued measures (PVMs). Here, we argue that this generalized conception of observable enables a consistent notion of unsharp reality and with it an adequate concept of joint properties. A sharp or unsharp property manifests itself as an element of sharp or unsharp reality by its tendency to become actual or to actualize a specific measurement outcome. This actualization tendency-or potentiality-of a property is quantified by the associated quantum probability. The resulting single-case interpretation of probability as a degree of reality will be explained in detail and its role in addressing the tensions between quantum and classical accounts of the physical world will be elucidated. It will be shown that potentiality can be viewed as a causal agency that evolves in a well-defined way

    Dietary Supplementation with Soluble Plantain Non-Starch Polysaccharides Inhibits Intestinal Invasion of Salmonella Typhimurium in the Chicken

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    Soluble fibres (non-starch polysaccharides, NSP) from edible plants but particularly plantain banana (Musa spp.), have been shown in vitro and ex vivo to prevent various enteric pathogens from adhering to, or translocating across, the human intestinal epithelium, a property that we have termed contrabiotic. Here we report that dietary plantain fibre prevents invasion of the chicken intestinal mucosa by Salmonella. In vivo experiments were performed with chicks fed from hatch on a pellet diet containing soluble plantain NSP (0 to 200 mg/d) and orally infected with S.Typhimurium 4/74 at 8 d of age. Birds were sacrificed 3, 6 and 10 d post-infection. Bacteria were enumerated from liver, spleen and caecal contents. In vitro studies were performed using chicken caecal crypts and porcine intestinal epithelial cells infected with Salmonella enterica serovars following pre-treatment separately with soluble plantain NSP and acidic or neutral polysaccharide fractions of plantain NSP, each compared with saline vehicle. Bacterial adherence and invasion were assessed by gentamicin protection assay. In vivo dietary supplementation with plantain NSP 50 mg/d reduced invasion by S.Typhimurium, as reflected by viable bacterial counts from splenic tissue, by 98.9% (95% CI, 98.1–99.7; P<0.0001). In vitro studies confirmed that plantain NSP (5–10 mg/ml) inhibited adhesion of S.Typhimurium 4/74 to a porcine epithelial cell-line (73% mean inhibition (95% CI, 64–81); P<0.001) and to primary chick caecal crypts (82% mean inhibition (95% CI, 75–90); P<0.001). Adherence inhibition was shown to be mediated via an effect on the epithelial cells and Ussing chamber experiments with ex-vivo human ileal mucosa showed that this effect was associated with increased short circuit current but no change in electrical resistance. The inhibitory activity of plantain NSP lay mainly within the acidic/pectic (homogalacturonan-rich) component. Supplementation of chick feed with plantain NSP was well tolerated and shows promise as a simple approach for reducing invasive salmonellosis

    Loss of adipose triglyceride lipase is associated with human cancer and induces mouse pulmonary neoplasia

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    Metabolic reprogramming is a hallmark of cancer. Understanding cancer metabolism is instrumental to devise innovative therapeutic approaches. Anabolic metabolism, including the induction of lipogenic enzymes, is a key feature of proliferating cells. Here, we report a novel tumor suppressive function for adipose triglyceride lipase (ATGL), the rate limiting enzyme in the triglyceride hydrolysis cascade. In immunohistochemical analysis, non-small cell lung cancers, pancreatic adenocarcinoma as well as leiomyosarcoma showed significantly reduced levels of ATGL protein compared to corresponding normal tissues. The ATGL gene was frequently deleted in various forms of cancers. Low levels of ATGL mRNA correlated with significantly reduced survival in patients with ovarian, breast, gastric and non-small cell lung cancers. Remarkably, pulmonary neoplasia including invasive adenocarcinoma developed spontaneously in mice lacking ATGL pointing to an important role for this lipase in controlling tumor development. Loss of ATGL, as detected in several forms of human cancer, induces spontaneous development of pulmonary neoplasia in a mouse model. Our results, therefore, suggest a novel tumor suppressor function for ATGL and contribute to the understanding of cancer metabolism. We propose to evaluate loss of ATGL protein expression for the diagnosis of malignant tumors. Finally, modulation of the lipolytic pathway may represent a novel therapeutic approach in the treatment of human cancer
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