108 research outputs found

    Distinct roles of Akt1 and Akt2 in regulating cell migration and epithelial–mesenchymal transition

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    The Akt family of kinases are activated by growth factors and regulate pleiotropic cellular activities. In this study, we provide evidence for isoform-specific positive and negative roles for Akt1 and -2 in regulating growth factor–stimulated phenotypes in breast epithelial cells. Insulin-like growth factor-I receptor (IGF-IR) hyperstimulation induced hyperproliferation and antiapoptotic activities that were reversed by Akt2 down-regulation. In contrast, Akt1 down-regulation in IGF-IR–stimulated cells promoted dramatic neomorphic effects characteristic of an epithelial–mesenchymal transition (EMT) and enhanced cell migration induced by IGF-I or EGF stimulation. The phenotypic effects of Akt1 down-regulation were accompanied by enhanced extracellular signal–related kinase (ERK) activation, which contributed to the induction of migration and EMT. Interestingly, down-regulation of Akt2 suppressed the EMT-like morphological conversion induced by Akt1 down-regulation in IGF-IR–overexpressing cells and inhibited migration in EGF-stimulated cells. These results highlight the distinct functions of Akt isoforms in regulating growth factor–stimulated EMT and cell migration, as well as the importance of Akt1 in cross-regulating the ERK signaling pathway

    Hyper-precarious lives : Migrants, work and forced labour in the Global North

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    This paper unpacks the contested inter-connections between neoliberal work and welfare regimes, asylum and immigration controls, and the exploitation of migrant workers. The concept of precarity is explored as a way of understanding intensifying and insecure post-Fordist work in late capitalism. Migrants are centrally implicated in highly precarious work experiences at the bottom end of labour markets in Global North countries, including becoming trapped in forced labour. Building on existing research on the working experiences of migrants in the Global North, the main part of the article considers three questions. First, what is precarity and how does the concept relate to working lives? Second, how might we understand the causes of extreme forms of migrant labour exploitation in precarious lifeworlds? Third, how can we adequately theorize these particular experiences using the conceptual tools of forced labour, slavery, unfreedom and precarity? We use the concept of ‘hyper-precarity’ alongside notions of a ‘continuum of unfreedom’ as a way of furthering human geographical inquiry into the intersections between various terrains of social action and conceptual debate concerning migrants’ precarious working experiences

    Highly efficient single molecule detection in different micro and submicrometer channels with cw-excitation

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    In this article we describe a detailed comparison between single molecule detection in three different types of microchannels. The overall detection efficiencies and the signal-to-noise ratios are compared. A new data evaluation technique that is used is explained in detail. The average number of photons per molecule is calculated from the measurements and the detection properties of each channel with respect to the diffusional characteristics of the dye molecules are investigated. From the detection efficiencies advantages and drawbacks of the individual methods are elucidated as well as possible applications of the techniques are illustrated

    Moho and Lithosphere-Asthenosphere Boundaries in East Africa from regional gravity data

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    The analysis, processing and interpretation of gravity anomaly fields between East Africa and South Arabia are here studied as a contribution to the reconstruction of the Afro-Arabian plates geodynamical evolution.Baaritaan ku saabsan bedad cufsijiidad oo aan caadi ahayn oo ka dhexeeya Afrika Bari iyo Koofur Areebiya; diraasaddani waxay qayb ka qaadanaysaa dibudhiska kobaca "Afro-Arabian plates geodynamical evolution".Analisi, elaborazione e interpretazione delle anomalie nei campi di gravità tra l'Africa orientale e l'Arabia meridionale, qui studiati come un contributo alla ricostruzione dell'evoluzione geodinamica delle placche afro-arabe

    Highly efficient single molecule detection in different micro and submicrometer channels with cw-excitation

    No full text
    In this article we describe a detailed comparison between single molecule detection in three different types of microchannels. The overall detection efficiencies and the signal-to-noise ratios are compared. A new data evaluation technique that is used is explained in detail. The average number of photons per molecule is calculated from the measurements and the detection properties of each channel with respect to the diffusional characteristics of the dye molecules are investigated. From the detection efficiencies advantages and drawbacks of the individual methods are elucidated as well as possible applications of the techniques are illustrated
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