5,186 research outputs found

    Distinct dynamical behavior in Erd\H{o}s-R\'enyi networks, regular random networks, ring lattices, and all-to-all neuronal networks

    Get PDF
    Neuronal network dynamics depends on network structure. In this paper we study how network topology underpins the emergence of different dynamical behaviors in neuronal networks. In particular, we consider neuronal network dynamics on Erd\H{o}s-R\'enyi (ER) networks, regular random (RR) networks, ring lattices, and all-to-all networks. We solve analytically a neuronal network model with stochastic binary-state neurons in all the network topologies, except ring lattices. Given that apart from network structure, all four models are equivalent, this allows us to understand the role of network structure in neuronal network dynamics. Whilst ER and RR networks are characterized by similar phase diagrams, we find strikingly different phase diagrams in the all-to-all network. Neuronal network dynamics is not only different within certain parameter ranges, but it also undergoes different bifurcations (with a richer repertoire of bifurcations in ER and RR compared to all-to-all networks). This suggests that local heterogeneity in the ratio between excitation and inhibition plays a crucial role on emergent dynamics. Furthermore, we also observe one subtle discrepancy between ER and RR networks, namely ER networks undergo a neuronal activity jump at lower noise levels compared to RR networks, presumably due to the degree heterogeneity in ER networks that is absent in RR networks. Finally, a comparison between network oscillations in RR networks and ring lattices shows the importance of small-world properties in sustaining stable network oscillations.Comment: 9 pages, 4 figure

    Fibonacci Oscillators in the Landau Diamagnetism problem

    Get PDF
    We address the issue of the Landau diamagnetism problem via qq-deformed algebra of Fibonacci oscillators through its generalized sequence of two real and independent deformation parameters q1q_1 and q2q_2. We obtain qq-deformed thermodynamic quantities such as internal energy, number of particles, magnetization and magnetic susceptibility which recover their usual form in the degenerate limit q12+q22q_1^2 + q_2^2=1.Comment: Latex, 11 pages, two figures, version to appear in Physica

    Annotated checklist and illustrated key to braconid parasitoids (Hymenoptera, Braconidae) of economically important fruit flies (Diptera, Tephritidae) in Brazil

    Get PDF
    The braconid parasitoids of fruit-infesting flies have been more intensively studied from the middle to late 1990s, when taxonomic research was restarted in Brazil. At the same time, efforts toward the biological control of fruit flies intensified, and an exotic species, Diachasmimorpha longicaudata, was introduced. In the decade 2010, another exotic species, Fopius arisanus, was introduced, and two new species of Doryctobracon were described. Currently, 12 species of braconids from the subfamilies Alysiinae (two species) and Opiinae (10 species) are associated with fruit flies of economic importance in Brazil, two of which are introduced species. More than half of the species belong to the genus Doryctobracon, with D. areolatus (Szépligeti) the most widely distributed species in Brazil.Fil: Fidelis Marinho, Claudia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro de Investigaciones y Transferencia de Catamarca. Universidad Nacional de Catamarca. Centro de Investigaciones y Transferencia de Catamarca; ArgentinaFil: Costa, Valmir A.. Universidade Estadual de Campinas; BrasilFil: Zucchi, Roberto A.. Universidade do Sao Paulo. Escola Superior de Agricultura Luiz de Queiroz; Brasi

    Systematic optimization of human pluripotent stem cells media using Design of Experiments.

    Get PDF
    Human pluripotent stem cells (hPSC) are used to study the early stages of human development in vitro and, increasingly due to somatic cell reprogramming, cellular and molecular mechanisms of disease. Cell culture medium is a critical factor for hPSC to maintain pluripotency and self-renewal. Numerous defined culture media have been empirically developed but never systematically optimized for culturing hPSC. We applied design of experiments (DOE), a powerful statistical tool, to improve the medium formulation for hPSC. Using pluripotency and cell growth as read-outs, we determined the optimal concentration of both basic fibroblast growth factor (bFGF) and neuregulin-1 beta 1 (NRG1β1). The resulting formulation, named iDEAL, improved the maintenance and passage of hPSC in both normal and stressful conditions, and affected trimethylated histone 3 lysine 27 (H3K27me3) epigenetic status after genetic reprogramming. It also enhances efficient hPSC plating as single cells. Altogether, iDEAL potentially allows scalable and controllable hPSC culture routine in translational research. Our DOE strategy could also be applied to hPSC differentiation protocols, which often require numerous and complex cell culture media

    Unclassified autoimmune pancreatitis mimicking pancreatic cancer

    Get PDF
    A 24-year-old black male presented with a 1-week obstructive jaundice and intermittent abdominal pain, with no significant weight loss and an unsuspicious abdominal exam. Blood chemistry showed a cholestatic pattern but a complete immunological and tumoral panel (anti-smooth muscle antibody, anti-mitochondrial antibody, anti-nuclear antibody, anti-neutrophil cytoplasmic antibody, anti-Smith, anti-double-stranded-DNA antibody (anti-dsDNA), complement C3/C4, carcinoembryonic antigen, CA 19-9 and IgG4) were all within normal limits. Abdominal ultrasound revealed dilatation of the intra and extra-hepatic bile ducts. CT scan showed an abnormal dilatation of the distal bile duct but no focal enlargement of the head of the pancreas. Endoscopic ultrasound suggested an inflammatory process but the magnetic resonance cholangio-pancreatography favored a neoplastic obstruction of the distal common bile duct. Fine-needle aspiration cytology was insufficient for definitive diagnosis and the patient underwent major surgery. Follow-up with mild exocrine pancreatic insufficiency treated with enzyme replacement.info:eu-repo/semantics/publishedVersio
    corecore