CDK-dependent nuclear localization of B-Cyclin Clb1 promotes FEAR activation during meiosis I in budding yeast

Cyclin-dependent kinases (CDK) are master regulators of the cell cycle in eukaryotes. CDK activity is regulated by the presence, post-translational modification and spatial localization of its regulatory subunit cyclin. In budding yeast, the B-cyclin Clb1 is phosphorylated and localizes to the nucleus during meiosis I. However the functional significance of Clb1's phosphorylation and nuclear localization and their mutual dependency is unknown. In this paper, we demonstrate that meiosis-specific phosphorylation of Clb1 requires its import to the nucleus but not vice versa. While Clb1 phosphorylation is dependent on activity of both CDK and polo-like kinase Cdc5, its nuclear localization requires CDK but not Cdc5 activity. Furthermore we show that increased nuclear localization of Clb1 during meiosis enhances activation of FEAR (Cdc Fourteen Early Anaphase Release) pathway. We discuss the significance of our results in relation to regulation of exit from meiosis I

Numerical analysis of gas-solid behavior in a cyclone separator for circulating fluidized bed system

Cyclones are one of the most widely used gas-solid separators in circulating fluidized bed (CFB) systems. This paper focuses on numerical study of the gas-solid flow in a cyclone attached to the CFB system. The objective was to understand the flow pattern in the cyclone in order to run the CFB setup problem free. The previous works on cyclone separators do not include critical parameter such as coefficient of restitution which is responsible for swirling effect and increase in efficiency. Reynolds stress model (RSM) is used to obtain the gas flow characteristics. The resulting flow and pressure fields are verified by comparing with the measured experimental results and then used in the determination of solids flow that is simulated by the use of a discrete phase model. The simulation results show how the particle trajectories and cyclone efficiency change with varying coefficient of restitution and particle size keeping inlet velocity of gas and mean particle diameter constant. The separation efficiency, pressure drop and particle trapping time from the numerical analysis are shown to be comparable to those observed experimentally. The velocity distribution pattern obtained from the analysis exhibits strong flow recirculation with large turbulent eddies in the cyclone separator. The particle trajectories depend upon relative velocity of fluid/particles and concentration of particles. Efficiency of the cyclone is found to be dependent on particle size and coefficient of restitution. The results obtained are further utilized to optimize the velocity range of gas flow in the loop seal and riser for stable operation of CFB setup

Measurement of charged particle spectra in minimum-bias events from proton-proton collisions at root s =13 TeV

Pseudorapidity, transverse momentum, and multiplicity distributions are measured in the pseudorapidity range vertical bar eta vertical bar 0.5 GeV in proton-proton collisions at a center-of-mass energy of root s = 13 TeV. Measurements are presented in three different event categories. The most inclusive of the categories corresponds to an inelastic pp data set, while the other two categories are exclusive subsets of the inelastic sample that are either enhanced or depleted in single diffractive dissociation events. The measurements are compared to predictions from Monte Carlo event generators used to describe high-energy hadronic interactions in collider and cosmic-ray physics.Peer reviewe