1,913 research outputs found

    Heat shock induces variably the major heat shock proteins of CV1 clones

    Get PDF
    AbstractCV1 cells have been subcloned several times. Five of these clones were studied for the induction of the major heat shock proteins. These CV1 clones exhibit morphological differences as well as differences in SDS-PAGE protein profiles. These clones responded to heat shock variably as judged from the induction of the major heat shock proteins, 70, 72 and 92 kDa. Variable expression of the heat shock proteins suggests that the selective pressure for isolation of cell clones may affect gene expression differently

    A workflow for learning objects lifecycle and reuse: Towards evaluating cost effective reuse

    Get PDF
    Over the last decade Learning Objects (LOs) have gained a lot of attention as a common format for developing and sharing digital educational content in the field of technology-enhanced learning. The main advantage of LOs is considered to be their potential for component-based reuse in different learning settings supporting different learning activities. However, despite the importance of the concept of reuse and its potential benefits in digital educational content production and deployment, there are only sporadic efforts to study issues related to LOs reuse that would allow interested parties (such as people, organizations and initiatives) to assess the conditions for and eventually implement systematic LOs reuse within the context of learning activities design and development. This is a drawback in adopting the LOs paradigm towards reducing costs and effort. In this paper, we study existing efforts for the definition of the different steps involved during the LOs lifecycle, we identify the aspects of LOs reuse within the context of learning activities design and development, we propose a thorough workflow for LOs lifecycle that can support LOs reuse and enable us to define a set of metrics for cost effective LOs reuse, and discuss the cost effectiveness conditions in various use cases

    Supersymmetric Laser Arrays

    Full text link
    The theoretical framework of supersymmetry (SUSY) aims to relate bosons and fermions -- two profoundly different species of particles -- and their interactions. While this space-time symmetry is seen to provide an elegant solution to many unanswered questions in high-energy physics, its experimental verification has so far remained elusive. Here, we demonstrate that, notions from supersymmetry can be strategically utilized in optics in order to address one of the longstanding challenges in laser science. In this regard, a supersymmetric laser array is realized, capable of emitting exclusively in its fundamental transverse mode. Our results not only pave the way towards devising new schemes for scaling up radiance in integrated lasers, but also on a more fundamental level, they could shed light on the intriguing synergy between non-Hermiticity and supersymmetry

    Effect of 910-MHz Electromagnetic Field on Rat Bone Marrow

    Get PDF
    Aiming to investigate the possibility of electromagnetic fields (EMF) developed by nonionizing radiation to be a noxious agent capable of inducing genotoxicity to humans, in the current study we have investigated the effect of 910-MHz EMF in rat bone marrow. Rats were exposed daily for 2 h over a period of 30 consecutive days. Studying bone marrow smears from EMF-exposed and sham-exposed animals, we observed an almost threefold increase of micronuclei (MN) in polychromatic erythrocytes (PCEs) after EMF exposure. An induction of MN was also observed in polymorphonuclear cells. The induction of MN in female rats was less than that in male rats. The results indicate that 910-MHz EMF could be considered as a noxious agent capable of producing genotoxic effects

    Developing teachers' competences for designing inclusive learning experiences

    Get PDF
    Inclusive education, namely the process of providing all learners with equal educational opportunities, is a major challenge for many educational systems worldwide. In order to address this issue, a widely used framework has been developed, namely the Universal Design for Learning (UDL), which aims to provide specific educational design guidelines to ensure accessibility of all learner types to the learning environment. On the other hand, nowadays teachers are provided with ample opportunities for freely accessing a wide number of Open Educational Resources (OERs) that are available through existing OER initiatives. Within this context and following the UDL principles, teachers are expected to be able to select and transform and/or augment, OERs to fit their learners' diverse needs towards delivering inclusive learning experiences. This calls for developing specific teachers' competences that are aligned with existing competence frameworks such as the Competence Framework for Inclusive Teachers (CFIT) towards effectively engaging them in the aforementioned process. To this end, the scope of this paper is to present the design, implementation and evaluation of a teacher professional development program (PDP) aligned with CFIT for designing inclusive OERs by applying the UDL principles. The evaluation results of the teacher PDP demonstrated its added value for developing teachers' competences towards designing inclusive learning experiences for their students

    Cytochrome P450 CYP1A1: wider roles in cancer progression and prevention

    Get PDF
    CYP1A1 is one of the main cytochrome P450 enzymes, examined extensively for its capacity to activate compounds with carcinogenic properties. Continuous exposure to inhalation chemicals and environmental carcinogens is thought to increase the level of CYP1A1 expression in extrahepatic tissues, through the aryl hydrocarbon receptor (AhR). Although the latter has long been recognized as a ligand-induced transcription factor, which is responsible for the xenobiotic activating pathway of several phase I and phase II metabolizing enzymes, recent evidence suggests that the AhR is involved in various cell signaling pathways critical to cell cycle regulation and normal homeostasis. Disregulation of these pathways is implicated in tumor progression. In addition, it is becoming increasingly evident that CYP1A1 plays an important role in the detoxication of environmental carcinogens, as well as in the metabolic activation of dietary compounds with cancer preventative activity. Ultimately the contribution of CYP1A1 to cancer progression or prevention may depend on the balance of procarcinogen activation/detoxication and dietary natural product extrahepatic metabolism

    Bragg solitons in nonlinear PT-symmetric periodic potentials

    Get PDF
    It is shown that slow Bragg soliton solutions are possible in nonlinear complex parity-time (PT) symmetric periodic structures. Analysis indicates that the PT-symmetric component of the periodic optical refractive index can modify the grating band structure and hence the effective coupling between the forward and backward waves. Starting from a classical modified massive Thirring model, solitary wave solutions are obtained in closed form. The basic properties of these slow solitary waves and their dependence on their respective PT-symmetric gain/loss profile are then explored via numerical simulations.Comment: 6 pages, 4 figures, published in Physical Review
    • …
    corecore