115 research outputs found

    Fractal Fluctuations and Quantum-Like Chaos in the Brain by Analysis of Variability of Brain Waves: A New Method Based on a Fractal Variance Function and Random Matrix Theory

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    We developed a new method for analysis of fundamental brain waves as recorded by EEG. To this purpose we introduce a Fractal Variance Function that is based on the calculation of the variogram. The method is completed by using Random Matrix Theory. Some examples are given

    The PI3K-Akt pathway inhibits senescence and promotes self-renewal of human skin-derived precursors in vitro

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    Skin-derived precursors (SKPs) are embryonic neural crest- or somite-derived multipotent progenitor cells with properties of dermal stem cells. Although a large number of studies deal with their differentiation ability and potential applications in tissue damage repair, only a few studies have concentrated on the regulation of SKP self-renewal. Here, we found that after separation from their physiological microenvironment, human foreskin-derived SKPs (hSKPs) quickly senesced and lost their self-renewal ability. We observed a sharp decrease in Akt activity during this process, suggesting a possible role of the PI3K-Akt pathway in hSKP maintenance in vitro. Blocking this pathway with several inhibitors inhibited hSKP proliferation and sphere formation and increased hSKP senescence. In contrast, activating this pathway with PDGF-AA and a PTEN inhibitor, bpV(pic), promoted proliferation, improved sphere formation, and alleviated senescence of hSKPs, without altering their differentiation potential. Data also implied that this effect was associated with altered actions of FoxO3 and GSK-3β. Our results suggest an important role of the PI3K-Akt pathway in the senescence and self-renewal of hSKPs. These findings also provide a better understanding of the cellular mechanisms underlying hSKP self-renewal and stem cell senescence to allow more efficient expansion of hSKPs for regenerative medical applications

    Waging peace: militarising pacifism in Central Africa and the problem of geography, 1962

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    Despite the discipline having undergone a ‘peace turn’ in recent years, the history of the peace movement itself remains curiously under explored by geographers. This paper retraces the World Peace Brigade and its collaboration with the Northern Rhodesian independence movement in 1962. I argue that the Brigade offers geographers important insights into how ideas of peace have been circulated, adapted and even resisted. The paper suggests that geography poses a distinct conceptual problem for peace movements, which must simultaneously operate beyond conventional forms of territorial politics while remaining sufficiently flexible in the political arena for their strength and relevance. In Central Africa this meant the Brigade developed two, ultimately incompatible, conceptions of peace: an internationalist one that stressed world community, and a local one that adapted pacifism for nationalist movements. I suggest this case study has two implications for peace research in geography. First, it encourages us to remain attentive to the big stories of peace and, specifically, the way in which the peace movement has been a historically important conduit for a range of internationalist ideas. Second, the histories of waging peace (peace armies, civil disobedience, etc.) allow us to critically interrogate the co-constitutive geographies of violence and nonviolence while retaining peace as a distinct category around which to promote political engagement

    GTPase regulator associated with the focal adhesion kinase (GRAF) transcript was down-regulated in patients with myeloid malignancies

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    <p>Abstract</p> <p>Background</p> <p>GTPase regulator associated with the focal adhesion kinase (<it>GRAF</it>), a putative tumor suppressor gene, is found inactivated in hematopoietic malignancies by either genetic or epigenetic abnormalities. However, the expression level of <it>GRAF </it>gene has not yet been studied in leukemia. The aim of this study was to investigate the expression level of <it>GRAF </it>gene in those patients with myeloid malignancies including acute myeloid leukemia (AML), myelodysplastic syndrome (MDS) and chronic myeloid leukemia (CML).</p> <p>Methods</p> <p>The expression levels of <it>GRAF </it>transcript were determined in 94 patients using real-time quantitative PCR (RQ-PCR). Clinical and laboratory data of these patients were collected and analyzed.</p> <p>Results</p> <p>The significantly decreased level of <it>GRAF </it>transcript was observed in three myeloid malignancies compared to controls. Within AML, there was no difference in the level of <it>GRAF </it>transcript among different FAB subtypes (<it>P </it>> 0.05). Difference was not observed in the amount of <it>GRAF </it>mRNA between CML at chronic phase and controls. As CML progressed, <it>GRAF </it>transcript significantly decreased. In MDS, three cases with 5q deletion had lower <it>GRAF </it>transcript than four without 5q deletion (median 0.76 vs 2.99) (<it>P </it>> 0.05).</p> <p>Conclusion</p> <p>our results demonstrate that the <it>GRAF </it>transcript is decreased in myeloid malignancies.</p

    The Quantum Mitochondrion and Optimal Health

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    A sufficiently complex set of molecules, if subject to perturbation, will self-organise and show emergent behaviour. If such a system can take on information it will become subject to natural selection. This could explain how self-replicating molecules evolved into life and how intelligence arose. A pivotal step in this evolutionary process was of course the emergence of the eukaryote and the advent of the mitochondrion, which both enhanced energy production per cell and increased the ability to process, store and utilise information. Recent research suggest that from its inception life embraced quantum effects such as “tunnelling” and “coherence” while competition and stressful conditions provided a constant driver for natural selection. We believe that the biphasic adaptive response to stress described by hormesis – a process that captures information to enable adaptability, is central to this whole process. Critically, hormesis could improve mitochondrial quantum efficiency, improving the ATP/ROS ratio, while inflammation, which is tightly associated with the aging process, might do the opposite. This all suggests that to achieve optimal health and healthy ageing, one has to sufficiently stress the system to ensure peak mitochondrial function, which itself could reflect selection of optimum efficiency at the quantum level

    Persistent activation of interlinked type 2 airway epithelial gene networks in sputum-derived cells from aeroallergen-sensitized symptomatic asthmatics

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    © 2018 The Author(s). Atopic asthma is a persistent disease characterized by intermittent wheeze and progressive loss of lung function. The disease is thought to be driven primarily by chronic aeroallergen-induced type 2-associated inflammation. However, the vast majority of atopics do not develop asthma despite ongoing aeroallergen exposure, suggesting additional mechanisms operate in conjunction with type 2 immunity to drive asthma pathogenesis. We employed RNA-Seq profiling of sputum-derived cells to identify gene networks operative at baseline in house dust mite-sensitized (HDM S ) subjects with/without wheezing history that are characteristic of the ongoing asthmatic state. The expression of type 2 effectors (IL-5, IL-13) was equivalent in both cohorts of subjects. However, in HDM S -wheezers they were associated with upregulation of two coexpression modules comprising multiple type 2- and epithelial-associated genes. The first module was interlinked by the hubs EGFR, ERBB2, CDH1 and IL-13. The second module was associated with CDHR3 and mucociliary clearance genes. Our findings provide new insight into the molecular mechanisms operative at baseline in the airway mucosa in atopic asthmatics undergoing natural aeroallergen exposure, and suggest that susceptibility to asthma amongst these subjects involves complex interactions between type 2- and epithelial-associated gene networks, which are not operative in equivalently sensitized/exposed atopic non-asthmatics

    NADPH oxidases: key modulators in aging and age-related cardiovascular diseases?

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    Reactive oxygen species (ROS) and oxidative stress have long been linked to aging and diseases prominent in the elderly such as hypertension, atherosclerosis, diabetes and atrial fibrillation (AF). NADPH oxidases (Nox) are a major source of ROS in the vasculature and are key players in mediating redox signalling under physiological and pathophysiological conditions. In this review, we focus on the Nox-mediated ROS signalling pathways involved in the regulation of 'longevity genes' and recapitulate their role in age-associated vascular changes and in the development of age-related cardiovascular diseases (CVDs). This review is predicated on burgeoning knowledge that Nox-derived ROS propagate tightly regulated yet varied signalling pathways, which, at the cellular level, may lead to diminished repair, the aging process and predisposition to CVDs. In addition, we briefly describe emerging Nox therapies and their potential in improving the health of the elderly population

    Resource Warfare, Pacification and the Spectacle of ‘Green’ Development: Logics of Violence in Engineering Extraction in Southern Madagascar

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    Bringing political ecology's concern with the critical politics of nature and resource violence into dialogue with key debates in political geography, critical security studies and research on the geographies and phenomenology of violence and warfare, this paper explores strategies ‘from above’ in relation to the establishment and operation of the Rio Tinto QIT-Madagascar Minerals (QMM) ilmenite mine in southeast Madagascar. While QMM claims to be a responsible ‘green’ self-regulator and sustainable development actor, it has triggered serious social, environmental and legal conflicts since its inception, including allegations of a ‘double land grab’ to accommodate mining activities and compensatory biodiversity offsetting. We argue that ‘pacification’, theorised as a productive form of violence that works through the re-ordering of socio-nature, underwrites the forms of ‘security’, ‘stability’ and even ‘sustainability’ that facilitate multiple and overlapping strategies of value extraction in the territorial and extra-territorial spaces occupied by the QMM mine partnership. By situating these dynamics historically, we identify ways in which pacification draws upon sedimented and evolving logics of racialised violence to facilitate operations and silence opposition
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