45 research outputs found

    Employing a novel bioelastomer to toughen polylactide

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    Biodegradable, biocompatible polylactide (PLA) synthesized from renewable resources has attracted extensive interests over the past decades and holds great potential to replace many petroleum-derived plastics. With no loss of biodegradability and biocompatibility, we highly toughened PLA using a novel bioelastomer (BE)–synthesized from biomass diols and diacids. Although PLA and BE are immiscible, BE particles of ∼1 μm in diameter are uniformly dispersed in the matrix, and this indicates some compatibility between PLA and BE. BE significantly increased the cold crystallization ability of PLA, which was valuable for practical processing and performance. SEM micrographs of fracture surface showed a brittle-to-ductile transition owing to addition of BE. At 11.5 vol%, notched Izod impact strength improved from 2.4 to 10.3 kJ/m2, 330% increment; the increase is superior to previous toughening effect by using petroleum-based tougheners

    Hominin reactions to herbivore distribution in the Lower Palaeolithic of the Southern Levant

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    We explore the relationship between the edaphic potential of soils and the mineral properties of the underlying geology as a means of mapping the differential productivity of different areas of the Pleistocene landscape for large herbivores. These factors strongly control the health of grazing animals irrespective of the particular types of vegetation growing on them, but they have generally been neglected in palaeoanthropological studies in favour of a more general emphasis on water and vegetation, which provide an incomplete picture. Taking the Carmel-Galilee-Golan region as an example, we show how an understanding of edaphic potential provides insight into how animals might have exploited the environment. In order to simplify the analysis, we concentrate on the Lower Palaeolithic period and the very large animals that dominate the archaeofaunal assemblages of this period. Topography and the ability of soils to retain water also contribute to the differential productivity and accessibility of different regions and to patterns of seasonal movements of the animals, which are essential to ensure a supply of healthy fodder throughout the year, especially for large animals such as elephants, which require substantial regions of good grazing and browsing. Other animals migrating in groups have similar needs. The complex topography of the Southern Levant with frequent sudden and severe changes in gradient, and a wide variety of landforms including rocky outcrops, cliffs, gorges, and ridges, places major limits on these patterns of seasonal movements. We develop methods of mapping these variables, based on the geology and our substantial field experience, in order to create a framework of landscape variation that can be compared with the locations and contents of archaeological sites to suggest ways in which early hominins used the variable features of the landscape to target animal prey, and we extend the analysis to the consideration of smaller mammals that were exploited more intensively after the disappearance of the elephants. We consider some of the ways in which this regional-scale approach can be further tested and refined, and advocate the development of such studies as an essential contribution to understanding the wider pattern of hominin dispersal

    Towards an approach for analysing external representations created during sensemaking using generative grammar

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    During sensemaking, users often create external representations to help them make sense of what they know, and what they need to know. In doing so, they necessarily adopt or construct some form of representational language using the tools at hand. By describing such languages implicit in representations we believe that we are better able to describe and differentiate what users do and better able to describe and differentiate interfaces that might support them. Drawing on approaches to the analysis of language, and in particular, Mann and Thompson’s Rhetorical Structure Theory, we analyse the representations that users create to expose their underlying ‘visual grammar’. We do this in the context of a user study involving evidential reasoning. Participants were asked to address an adapted version of IEEE VAST 2011 mini challenge 3 (interpret a potential terrorist plot implicit in a set of news reports). We show how our approach enables the unpacking of the heterogeneous and embedded nature of user-generated representations and allows us to show how visual grammars evolve and become more complex over time in response to evolving sensemaking needs

    Gliadin Peptide P31-43 Localises to Endocytic Vesicles and Interferes with Their Maturation

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    BACKGROUND: Celiac Disease (CD) is both a frequent disease (1:100) and an interesting model of a disease induced by food. It consists in an immunogenic reaction to wheat gluten and glutenins that has been found to arise in a specific genetic background; however, this reaction is still only partially understood. Activation of innate immunity by gliadin peptides is an important component of the early events of the disease. In particular the so-called "toxic" A-gliadin peptide P31-43 induces several pleiotropic effects including Epidermal Growth Factor Receptor (EGFR)-dependent actin remodelling and proliferation in cultured cell lines and in enterocytes from CD patients. These effects are mediated by delayed EGFR degradation and prolonged EGFR activation in endocytic vesicles. In the present study we investigated the effects of gliadin peptides on the trafficking and maturation of endocytic vesicles. METHODS/PRINCIPAL FINDINGS: Both P31-43 and the control P57-68 peptide labelled with fluorochromes were found to enter CaCo-2 cells and interact with the endocytic compartment in pulse and chase, time-lapse, experiments. P31-43 was localised to vesicles carrying early endocytic markers at time points when P57-68-carrying vesicles mature into late endosomes. In time-lapse experiments the trafficking of P31-43-labelled vesicles was delayed, regardless of the cargo they were carrying. Furthermore in celiac enterocytes, from cultured duodenal biopsies, P31-43 trafficking is delayed in early endocytic vesicles. A sequence similarity search revealed that P31-43 is strikingly similar to Hrs, a key molecule regulating endocytic maturation. A-gliadin peptide P31-43 interfered with Hrs correct localisation to early endosomes as revealed by western blot and immunofluorescence microscopy. CONCLUSIONS: P31-43 and P57-68 enter cells by endocytosis. Only P31-43 localises at the endocytic membranes and delays vesicle trafficking by interfering with Hrs-mediated maturation to late endosomes in cells and intestinal biopsies. Consequently, in P31-43-treated cells, Receptor Tyrosine Kinase (RTK) activation is extended. This finding may explain the role played by gliadin peptides in inducing proliferation and other effects in enterocytes from CD biopsies

    Re-defining the role of artificial intelligence (AI) in wiser service systems

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    Advances in Artificial Intelligence (AI) are raising important questions for companies, employees, consumers and policy makers. Researchers predict that intelligent machine will outperform humans in a wide range of tasks in the coming decade. Our purpose is to re-define the role of AI technologies and their relationship with people by re-thinking the concept of Intelligence Augmentation (IA), an interaction between AI technologies and people that, more than amplifying human capacities, produce a cognitive transformation. This transformation modifies the structure of humans thought, changing people’s cognitive processes and providing new tools to optimize interpretative schemas, useful to analyze the real world. In line with the need to define new directions in Service Science, new rules should be formulated to create a synergic and collaborative processes between humans (people) and machines. In order to design a wiser service system, this paper proposes T-shaped professionals as especially well-adapted for augmented and collaborative intelligence
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