35 research outputs found

    Coupling between internal spin dynamics and external degrees of freedom in the presence of colored noise

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    We observe asymmetric transition rates between Zeeman levels (spin-flips) of magnetically trapped atoms. The asymmetry strongly depends on the spectral shape of an applied noise. This effect follows from the interplay between the internal states of the atoms and their external degrees of freedom, where different trapped levels experience different potentials. Such insight may prove useful for controlling atomic states by the introduction of noise, as well as provide a better understanding of the effect of noise on the coherent operation of quantum systems.Comment: 5 pages, 4 figures; accepted to PR

    Trapping cold atoms using surface-grown carbon nanotubes

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    We present a feasibility study for loading cold atomic clouds into magnetic traps created by single-wall carbon nanotubes grown directly onto dielectric surfaces. We show that atoms may be captured for experimentally sustainable nanotube currents, generating trapped clouds whose densities and lifetimes are sufficient to enable detection by simple imaging methods. This opens the way for a novel type of conductor to be used in atomchips, enabling atom trapping at sub-micron distances, with implications for both fundamental studies and for technological applications

    University-level practical activities in bioinformatics benefit voluntary groups of pupils in the last 2 years of school

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    This work was supported in part by the Science and Technology Facilities Council under grant ST/M000435/1 to Daniel Barker.Background Bioinformatics—the use of computers in biology—is of major and increasing importance to biological sciences and medicine. We conducted a preliminary investigation of the value of bringing practical, university-level bioinformatics education to the school level. We conducted voluntary activities for pupils at two schools in Scotland (years S5 and S6; pupils aged 15–17). We used material originally developed for an optional final-year undergraduate module and now incorporated into 4273π, a resource for teaching and learning bioinformatics on the low-cost Raspberry Pi computer. Results Pupils’ feedback forms suggested our activities were beneficial. During the course of the activity, they provide strong evidence of increase in the following: pupils’ perception of the value of computers within biology; their knowledge of the Linux operating system and the Raspberry Pi; their willingness to use computers rather than phones or tablets; their ability to program a computer and their ability to analyse DNA sequences with a computer. We found no strong evidence of negative effects. Conclusions Our preliminary study supports the feasibility of bringing university-level, practical bioinformatics activities to school pupils.Publisher PDFPeer reviewe

    Ligand-independent degradation of epidermal growth factor receptor involves receptor ubiquitylation and hgs, an adaptor whose ubiquitin-interacting motif targets ubiquitylation by Nedd4

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    Ligand-dependent endocytosis of the epidermal growth factor receptor (EGFR) involves recruitment of a ubiquitin ligase, and sorting of ubiquitylated receptors to lysosomal degradation. By studying Hgs, a mammalian homolog of a yeast vacuolar-sorting adaptor, we provide information on the less understood, ligand- independent pathway of receptor endocytosis and degradation. Constitutive endocytosis involves receptor ubiquitylation and translocation to Hgs-containing endosomes. Whereas the lipid- binding motif of Hgs is necessary for receptor endocytosis, the ubiquitin-interacting motif negatively regulates receptor degradation. We demonstrate that the ubiquitin-interacting motif is endowed with two functions: it binds ubiquitylated proteins and it targets self-ubiquitylation by recruiting Nedd4, an ubiquitin ligase previously implicated in endocytosis. Based upon the dual function of the ubiquitin- interacting motif and its wide occurrence in endocytic adaptors, we propose a ubiquitin-interacting motif network that relays ubiquitylated membrane receptors to lysosomal degradation through successive budding events

    Nanoghosts: Mesenchymal Stem cells derived nanoparticles as a unique approach for cartilage regeneration

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    Osteoarthritis (OA) is a chronic degenerative disease, which affects the joints and is characterized by inflammation, cartilage loss and bone changes. Nowadays, there are no treatments for OA, and current therapies are focused on relieving the symptoms. As a new therapy approach, micro and nanoparticles have been extensively explored and among all the studied particles, the use of cell-membrane-based particles is expanding. Another promising approach studied to treat OA, is the use of mesenchymal stem cells (MSCs) which play an important role modulating inflammation. We developed a novel kind of MSCs' cytoplasmic-membrane-based nanoparticles, termed nano-ghosts (NGs).Retaining MSCs' surface properties and lacking cells' internal machinery allow the NGs to have immunomodulatory capacity and to be immune-evasive while not susceptible to host-induced changes.In this study, we demonstrate NGs' ability to target cartilage tissues, in vitro and in vivo, while modulating the inflammatory process. In vivo studies demonstrated NGs ability to act as an immunomodulatory drug slowing down cartilage degeneration process.Our proof-of-concept experiments show that NGs system is a versatile nano-carrier system, capable of therapeutics loading, with targeting capabilities towards healthy and inflamed cartilage cells.Our results, along with previously published data, clearly reveal the NGs system as a promising nano-carrier platform and as a potential immunomodulatory drug for several inflammation-related diseases.Imaging- and therapeutic targets in neoplastic and musculoskeletal inflammatory diseas
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