2,300 research outputs found

    Electrochemical communication with the inside of cells using micro-patterned vertical carbon nanofibre electrodes

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    With the rapidly increasing demands for ultrasensitive biodetection, the design and applications of new nano-scale materials for development of sensors based on optical and electrochemical transducers have attracted substantial interest. In particular, given the comparable sizes of nanomaterials and biomolecules, there exist plenty of opportunities to develop functional nanoprobes with biomolecules for highly sensitive and selective biosensing, shedding new light on cellular behaviour. Towards this aim, herein we interface cells with patterned nano-arrays of carbon nanofibers forming a nanosensor-cell construct. We show that such a construct is capable of electrochemically communicating with the intracellular environment.This work was supported by the Leverhulme Trust [grant numbers F/00 094/BD, ECF/2013-603]; the Biotechnology and Biological Sciences Research Council [grant number BB/L017059/1]; the European Research Council [Consolidator Grant, number 614787], the Engineering and Physical Sciences Research Council [EP/K027263/1]; and the NC3Rs [grant number NC/L00058X/1]

    Seminar Users in the Arabic Twitter Sphere

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    We introduce the notion of "seminar users", who are social media users engaged in propaganda in support of a political entity. We develop a framework that can identify such users with 84.4% precision and 76.1% recall. While our dataset is from the Arab region, omitting language-specific features has only a minor impact on classification performance, and thus, our approach could work for detecting seminar users in other parts of the world and in other languages. We further explored a controversial political topic to observe the prevalence and potential potency of such users. In our case study, we found that 25% of the users engaged in the topic are in fact seminar users and their tweets make nearly a third of the on-topic tweets. Moreover, they are often successful in affecting mainstream discourse with coordinated hashtag campaigns.Comment: to appear in SocInfo 201

    Non-destructive imaging of buried electronic interfaces using a decelerated scanning electron beam

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    Recent progress in nanotechnology enables the production of atomically abrupt interfaces in multilayered junctions, allowing to increase the number of transistors in a processor, as known as Moore’s law, for example. However, uniform electron transport has never been achieved across the entire interfacial area in junctions due to the existence of local defects, causing local heating and reduction in transport efficiency. To date, junction uniformity has been predominantly assessed by cross-sectional transmission electron microscopy, which requires slicing and milling processes with potentially introducing additional damage and deformation. It is therefore essential to develop an alternative non-destructive method. Here we show a non-destructive technique using scanning electron microscopy to map buried junction properties. By controlling the electron-beam energy, we demonstrate the contrast imaging of local junction resistances at a controlled depth. This technique can be applied to any buried junctions, from conventional semiconductor and metal devices to organic devices

    Oldest known pantherine skull and evolution of the tiger

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    The tiger is one of the most iconic extant animals, and its origin and evolution have been intensely debated. Fossils attributable to extant pantherine species-lineages are less than 2 MYA and the earliest tiger fossils are from the Calabrian, Lower Pleistocene. Molecular studies predict a much younger age for the divergence of modern tiger subspecies at <100 KYA, although their cranial morphology is readily distinguishable, indicating that early Pleistocene tigers would likely have differed markedly anatomically from extant tigers. Such inferences are hampered by the fact that well-known fossil tiger material is middle to late Pleistocene in age. Here we describe a new species of pantherine cat from Longdan, Gansu Province, China, Panthera zdanskyi sp. nov. With an estimated age of 2.55–2.16 MYA it represents the oldest complete skull of a pantherine cat hitherto found. Although smaller, it appears morphologically to be surprisingly similar to modern tigers considering its age. Morphological, morphometric, and cladistic analyses are congruent in confirming its very close affinity to the tiger, and it may be regarded as the most primitive species of the tiger lineage, demonstrating the first unequivocal presence of a modern pantherine species-lineage in the basal stage of the Pleistocene (Gelasian; traditionally considered to be Late Pliocene). This find supports a north-central Chinese origin of the tiger lineage, and demonstrates that various parts of the cranium, mandible, and dentition evolved at different rates. An increase in size and a reduction in the relative size of parts of the dentition appear to have been prominent features of tiger evolution, whereas the distinctive cranial morphology of modern tigers was established very early in their evolutionary history. The evolutionary trend of increasing size in the tiger lineage is likely coupled to the evolution of its primary prey species

    The smaller vesicomyid bivalves in the genus Isorropodon (Bivalvia, Vesicomyidae, Pliocardiinae) also harbour chemoautotrophic symbionts

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    Species of Isorropodon are vesicomyid bivalves for which little information is available regarding host phylogeny and bacterial symbioses. In this study we investigated the symbioses in three Isorropodon species from three cold seep areas: Isorropodon bigoti (Gulf of Guinea), Isorropodon megadesmus (Gulf of Cadiz) and Isorropodon perplexum (Eastern Mediterranean). Analysis of bacterial 16S ribosomal RNA gene sequences demonstrated that each vesicomyid species harbours a single symbiont phylotype, that symbionts from the three species cluster together, and that they are closely related to other known vesicomyid symbionts. These results are confirmed by other marker genes (encoding 23S rRNA and APS reductase) and by fluorescence in situ hybridization. Due to their extended depth range and transoceanic distribution Isorropodon species are interesting examples to further study evolutionary processes in bivalve hosts and their associated symbionts

    From External Evaluation, to School Self-evaluation, to Peer Review

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    Most modern systems of school education around the world now have highly developed evaluation processes. Following quickly in the wake of external evaluation policies have followed calls for schools to develop their own capacities for self-review. An OECD report (2013) describes a number of ways in which developing school evaluation capacity should be a priority for school improvement. Among the report’s suggestions are promoting peer learning among schools (pp. 469–470). This chapter describes the research on external evaluation, internal evaluation and the relationship between these two. It then moves on to define and describes peer review and chart its growth. The accountability dimension of peer review is also explored. Finally the existing evidence on peer review is presented from the vocational and schools sectors to show key findings so far, and key conditions for effective peer review are described

    Olives and olive oil are sources of electrophilic fatty acid nitroalkenes

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    Extra virgin olive oil (EVOO) and olives, key sources of unsaturated fatty acids in the Mediterranean diet, provide health benefits to humans. Nitric oxide (•NO) and nitrite (NO2-)-dependent reactions of unsaturated fatty acids yield electrophilic nitroalkene derivatives (NO 2-FA) that manifest salutary pleiotropic cell signaling responses in mammals. Herein, the endogenous presence of NO2-FA in both EVOO and fresh olives was demonstrated by mass spectrometry. The electrophilic nature of these species was affirmed by the detection of significant levels of protein cysteine adducts of nitro-oleic acid (NO2-OA-cysteine) in fresh olives, especially in the peel. Further nitration of EVOO by NO2- under acidic gastric digestive conditions revealed that human consumption of olive lipids will produce additional nitro-conjugated linoleic acid (NO2-cLA) and nitro-oleic acid (NO2-OA). The presence of free and protein-adducted NO2-FA in both mammalian and plant lipids further affirm a role for these species as signaling mediators. Since NO2-FA instigate adaptive anti-inflammatory gene expression and metabolic responses, these redox-derived metabolites may contribute to the cardiovascular benefits associated with the Mediterranean diet. © 2014 Fazzari et al

    Statistical analysis of arthroplasty data: I. Introduction and background

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    It is envisaged that guidelines for statistical analysis and presentation of results will improve the quality and value of research. The Nordic Arthroplasty Register Association (NARA) has therefore developed guidelines for the statistical analysis of arthroplasty register data. The guidelines are divided into two parts, this one with an introduction and a discussion of the background to the guidelines, and the second one with a more technical statistical discussion on how specific problems can be handled (Ranstam et al. 2011b, see pages x-y in this issue). This first part contains an overview of implant survival analysis and statistical methods used to evaluate factors with a potential influence on this outcome

    Event-related alpha suppression in response to facial motion

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    This article has been made available through the Brunel Open Access Publishing Fund.While biological motion refers to both face and body movements, little is known about the visual perception of facial motion. We therefore examined alpha wave suppression as a reduction in power is thought to reflect visual activity, in addition to attentional reorienting and memory processes. Nineteen neurologically healthy adults were tested on their ability to discriminate between successive facial motion captures. These animations exhibited both rigid and non-rigid facial motion, as well as speech expressions. The structural and surface appearance of these facial animations did not differ, thus participants decisions were based solely on differences in facial movements. Upright, orientation-inverted and luminance-inverted facial stimuli were compared. At occipital and parieto-occipital regions, upright facial motion evoked a transient increase in alpha which was then followed by a significant reduction. This finding is discussed in terms of neural efficiency, gating mechanisms and neural synchronization. Moreover, there was no difference in the amount of alpha suppression evoked by each facial stimulus at occipital regions, suggesting early visual processing remains unaffected by manipulation paradigms. However, upright facial motion evoked greater suppression at parieto-occipital sites, and did so in the shortest latency. Increased activity within this region may reflect higher attentional reorienting to natural facial motion but also involvement of areas associated with the visual control of body effectors. © 2014 Girges et al

    Two successful pregnancies in a woman with chronic myeloid leukemia exposed to nilotinib during the first trimester of her second pregnancy: case study

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    The occurrence of chronic myeloid leukemia in pregnancy is rare and its management poses a clinical challenge for physicians treating these patients. We report a 30-year-old woman with chronic myeloid leukemia who became pregnant twice successfully. Philadelphia-positive CML in its chronic phase was diagnosed at 16 weeks of her first gestation. At that time, she received no treatment throughout her pregnancy. At 38 weeks of gestation, a normal infant was delivered by cesarean section. At six weeks postpartum, the patient underwent imatinib mesylate therapy but she could not tolerate the treatment. The treatment was then changed to nilotinib at 400 mg orally b.i.d. Two years later, she became pregnant again while she was on nilotinib 200 mg b.i.d. The unplanned pregnancy was identified during her 7.4 weeks of gestation. Because the patient elected to continue her pregnancy, nilotinib was stopped immediately, and no further treatment was given until delivery. Neither obstetrical complications nor structural malformations in neonates in both pregnancies were observed. Both babies' growth and development have been normal. Although this experience is limited to a single patient, the success of this patient demonstrates that the management of chronic myeloid leukemia in pregnant women may be individualized based on the relative risks and benefits of the patient and fetus
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