257 research outputs found

    In-situ-Fabrikation

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    Die technischen Anforderungen zukünftiger Bauprozesse werden immer komplexer und erfordern maßgeschneiderte Lösungen. Computergesteuerte Produktionsmethoden ermöglichen die Herstellung individuell gestalteter Bauteile ohne erhöhten Kosten- und Zeitaufwand. Im Gegensatz zu stationären Maschinen können mobile Einheiten direkt auf einer bestehenden Baustelle eingesetzt werden und die Leistungsfähigkeit digital beschriebener Elemente produktiv mit einer In-situ-Bauweise vereinen. Der direkte Einsatz von Industrierobotern in der Architektur und die roboterbasierte Fertigung im Maßstab 1 : 1 sind Kernthemen dieser Arbeit. Mobile Robotersysteme müssen die gebaute Umgebung wahrnehmen und auf veränderte Bedingungen reaktiv eingehen können. Als Grundlage für die Dissertation dient die erforderliche Untersuchung des neuartigen Zusammenschlusses der roboterbasierten digitalen Fabrikation mit kognitiven Fähigkeiten. Der experimentelle Schwerpunkt dieser Forschungsarbeit liegt daher ebenso auf der digitalen Ansteuerung und Durchführung maschineller Bauprozesse wie auf der Entwicklung einer mobilen Robotereinheit und von erweiterten Rückkopplungs- und Lokalisierungstechniken durch Sensorik. Der Synergieeffekt zwischen den Forschungsbereichen Architektur und Experimentelle Informatik ist angesichts dieser interdisziplinären Themenbereiche von zentraler Bedeutung.The technical demands of future construction processes are becoming increasingly complex and require customised solutions. Computercontrolled production methods allow for the manufacture of individually designed building components without increasing outlay in terms of costs or time. In contrast to stationary machines, mobile units can be deployed directly on an existing building site and thus combine the capabilities of digitally defined elements with an in-situ construction technique. The core themes of this dissertation are the direct use of industrial robots in architecture and robot- assisted in-situ fabrication on a 1 : 1 scale. Mobile robotic systems must be able to perceive the constructed environment and respond to changing conditions. The necessary investigation of the innovative fusion of robot-based digital fabrication and cognitive abilities forms the basis of this research. Thus, the experimental focus of this research is on the development of a mobile robotic unit and advanced feedback and localisation techniques, as well as the digital management and implementation of mechanical construction processes. Due to the interdisciplinary nature of this subject area, the synergetic effect between the research areas of architecture and experimental computer science is of central importance

    Twelve tips for engaging learners in online discussions

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    Educators play a critical role in designing, facilitating and delivering an online medical education experience. Their teaching decisions and practices shape learners’ experiences and affect their achievements. This is true even in large-scale, open educational contexts such as Massive Open Online Courses (MOOCs), which are designed based on self-regulated and collaborative learning. Thus, it is particularly important to explore the ways in which educators can effectively support online or blended learning through their interactions with learners. The 12 tips in this article aim to provide medical educators with guidelines for creating engaging online discussions that both support and challenge learners’ understanding. The advice draws on a recent study examining the experiences and activities of 24 educators in MOOC discussion areas, and how their learners engaged with them. It provides practical recommendations on facilitating online discussions, producing engaging discussion tasks, and creating a balanced educator presence

    Spatio-temporal Models of Lymphangiogenesis in Wound Healing

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    Several studies suggest that one possible cause of impaired wound healing is failed or insufficient lymphangiogenesis, that is the formation of new lymphatic capillaries. Although many mathematical models have been developed to describe the formation of blood capillaries (angiogenesis), very few have been proposed for the regeneration of the lymphatic network. Lymphangiogenesis is a markedly different process from angiogenesis, occurring at different times and in response to different chemical stimuli. Two main hypotheses have been proposed: 1) lymphatic capillaries sprout from existing interrupted ones at the edge of the wound in analogy to the blood angiogenesis case; 2) lymphatic endothelial cells first pool in the wound region following the lymph flow and then, once sufficiently populated, start to form a network. Here we present two PDE models describing lymphangiogenesis according to these two different hypotheses. Further, we include the effect of advection due to interstitial flow and lymph flow coming from open capillaries. The variables represent different cell densities and growth factor concentrations, and where possible the parameters are estimated from biological data. The models are then solved numerically and the results are compared with the available biological literature.Comment: 29 pages, 9 Figures, 6 Tables (39 figure files in total

    Classical and revisionary theism on the divine as personal: a rapprochement?

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    To claim that the divine is a person or personal is, according to Richard Swinburne, ‘the most elementary claim of theism’ (1993, 101). I argue that, whether the classical theist’s concept of the divine as a person or personal is construed as an analogy or a metaphor, or a combination of the two, analysis necessitates qualification of that concept such that any differences between the classical theist’s concept of the divine as a person or personal and revisionary interpretations of that concept are merely superficial. Thus, either the classical theist has more in common with revisionary theism than he/she might care to admit, or classical theism is a multi-faceted position which encompasses interpretations which some might regard as revisionist. This article also explores and employs the use of a gender-neutral pronoun in talk about God

    TRY plant trait database - enhanced coverage and open access

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    Plant traits-the morphological, anatomical, physiological, biochemical and phenological characteristics of plants-determine how plants respond to environmental factors, affect other trophic levels, and influence ecosystem properties and their benefits and detriments to people. Plant trait data thus represent the basis for a vast area of research spanning from evolutionary biology, community and functional ecology, to biodiversity conservation, ecosystem and landscape management, restoration, biogeography and earth system modelling. Since its foundation in 2007, the TRY database of plant traits has grown continuously. It now provides unprecedented data coverage under an open access data policy and is the main plant trait database used by the research community worldwide. Increasingly, the TRY database also supports new frontiers of trait-based plant research, including the identification of data gaps and the subsequent mobilization or measurement of new data. To support this development, in this article we evaluate the extent of the trait data compiled in TRY and analyse emerging patterns of data coverage and representativeness. Best species coverage is achieved for categorical traits-almost complete coverage for 'plant growth form'. However, most traits relevant for ecology and vegetation modelling are characterized by continuous intraspecific variation and trait-environmental relationships. These traits have to be measured on individual plants in their respective environment. Despite unprecedented data coverage, we observe a humbling lack of completeness and representativeness of these continuous traits in many aspects. We, therefore, conclude that reducing data gaps and biases in the TRY database remains a key challenge and requires a coordinated approach to data mobilization and trait measurements. This can only be achieved in collaboration with other initiatives

    Pancreatitis after percutaneous ethanol injection into HCC: a minireview of the literature

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    Deaths after percutaneous ethanol injection (PEI) into hepatocellular carcinoma (HCC) may occur within a few hours to a few days following the procedure because of hemoperitoneum and haemorrhage from oesophageal varices or hepatic insufficiency. Pancreatitis has been recently reported as a rare lethal complication of intra-arterial PEI, another modality for treating HCCs. In this minireview, we analyze the literature concerning the development of acute pancreatitis after PEI. Pathogenesis of pancreatitis from opioids and ethanol is also addressed. Treatment with opioids to reduce the patient's abdominal pain after PEI in combination with the PEI itself may lead to direct toxic effects, thus favouring the development of pancreatitis

    The concept of RNA-assisted protein folding: the role of tRNA

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    We suggest that tRNA actively participates in the transfer of 3D information from mRNA to peptides - in addition to its well-known, "classical" role of translating the 3-letter RNA codes into the one letter protein code. The tRNA molecule displays a series of thermodynamically favored configurations during translation, a movement which places the codon and coded amino acids in proximity to each other and make physical contact between some amino acids and their codons possible. This specific codon-amino acid interaction of some selected amino acids is necessary for the transfer of spatial information from mRNA to coded proteins, and is known as RNA-assisted protein folding

    Brain architecture in the terrestrial hermit crab Coenobita clypeatus (Anomura, Coenobitidae), a crustacean with a good aerial sense of smell

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    <p>Abstract</p> <p>Background</p> <p>During the evolutionary radiation of Crustacea, several lineages in this taxon convergently succeeded in meeting the physiological challenges connected to establishing a fully terrestrial life style. These physiological adaptations include the need for sensory organs of terrestrial species to function in air rather than in water. Previous behavioral and neuroethological studies have provided solid evidence that the land hermit crabs (Coenobitidae, Anomura) are a group of crustaceans that have evolved a good sense of aerial olfaction during the conquest of land. We wanted to study the central olfactory processing areas in the brains of these organisms and to that end analyzed the brain of <it>Coenobita clypeatus </it>(Herbst, 1791; Anomura, Coenobitidae), a fully terrestrial tropical hermit crab, by immunohistochemistry against synaptic proteins, serotonin, FMRFamide-related peptides, and glutamine synthetase.</p> <p>Results</p> <p>The primary olfactory centers in this species dominate the brain and are composed of many elongate olfactory glomeruli. The secondary olfactory centers that receive an input from olfactory projection neurons are almost equally large as the olfactory lobes and are organized into parallel neuropil lamellae. The architecture of the optic neuropils and those areas associated with antenna two suggest that <it>C. clypeatus </it>has visual and mechanosensory skills that are comparable to those of marine Crustacea.</p> <p>Conclusion</p> <p>In parallel to previous behavioral findings of a good sense of aerial olfaction in C. clypeatus, our results indicate that in fact their central olfactory pathway is most prominent, indicating that olfaction is a major sensory modality that these brains process. Interestingly, the secondary olfactory neuropils of insects, the mushroom bodies, also display a layered structure (vertical and medial lobes), superficially similar to the lamellae in the secondary olfactory centers of <it>C. clypeatus</it>. More detailed analyses with additional markers will be necessary to explore the question if these similarities have evolved convergently with the establishment of superb aerial olfactory abilities or if this design goes back to a shared principle in the common ancestor of Crustacea and Hexapoda.</p
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