Systems Imaging of the Immune Synapse

Three-dimensional live cell imaging of the interaction of T cells with antigen presenting cells (APC) visualizes the subcellular distributions of signaling intermediates during T cell activation at thousands of resolved positions within a cell. These information-rich maps of local protein concentrations are a valuable resource in understanding T cell signaling. Here, we describe a protocol for the efficient acquisition of such imaging data and their computational processing to create four-dimensional maps of local concentrations. This protocol allows quantitative analysis of T cell signaling as it occurs inside live cells with resolution in time and space across thousands of cells

A Computational Model of the Ionic Currents, Ca2+ Dynamics and Action Potentials Underlying Contraction of Isolated Uterine Smooth Muscle

Uterine contractions during labor are discretely regulated by rhythmic action potentials (AP) of varying duration and form that serve to determine calcium-dependent force production. We have employed a computational biology approach to develop a fuller understanding of the complexity of excitation-contraction (E-C) coupling of uterine smooth muscle cells (USMC). Our overall aim is to establish a mathematical platform of sufficient biophysical detail to quantitatively describe known uterine E-C coupling parameters and thereby inform future empirical investigations of physiological and pathophysiological mechanisms governing normal and dysfunctional labors. From published and unpublished data we construct mathematical models for fourteen ionic currents of USMCs: currents (L- and T-type), current, an hyperpolarization-activated current, three voltage-gated currents, two -activated current, -activated current, non-specific cation current, - exchanger, - pump and background current. The magnitudes and kinetics of each current system in a spindle shaped single cell with a specified surface area∶volume ratio is described by differential equations, in terms of maximal conductances, electrochemical gradient, voltage-dependent activation/inactivation gating variables and temporal changes in intracellular computed from known fluxes. These quantifications are validated by the reconstruction of the individual experimental ionic currents obtained under voltage-clamp. Phasic contraction is modeled in relation to the time constant of changing . This integrated model is validated by its reconstruction of the different USMC AP configurations (spikes, plateau and bursts of spikes), the change from bursting to plateau type AP produced by estradiol and of simultaneous experimental recordings of spontaneous AP, and phasic force. In summary, our advanced mathematical model provides a powerful tool to investigate the physiological ionic mechanisms underlying the genesis of uterine electrical E-C coupling of labor and parturition. This will furnish the evolution of descriptive and predictive quantitative models of myometrial electrogenesis at the whole cell and tissue levels

A numerical method for pricing European options with proportional transaction costs

In the paper,we propose a numerical technique based on a finite difference scheme in space and an implicit time-stepping scheme for solving the Hamilton–Jacobi–Bellman (HJB) equation arising from the penalty formulation of the valuation ofEuropean options with proportional transaction costs. We show that the approximate solution from the numerical scheme converges to the viscosity solution of the HJB equation as the mesh sizes in space and time approach zero. We also propose an iterative scheme for solving the nonlinear algebraic system arising from the discretization and establish a convergence theory for the iterative scheme. Numerical experiments are presented to demonstrate the robustness and accuracy of the method

Philips Oy Healthcaren asiakaspalveluprosessin kehittäminen

Tämän insinöörityön aiheena on parantaa Philips Oy Healthcaren asiakaspalveluprosessia. Työn aiheeseen kuuluu vain pelkästään Suomessa palvelevaa Healthcaren osastoa. Työn tavoitteena oli parantaa Philips Oy Healthcaren asiakaspalveluprosessia työntekijöiden näkökulmasta, koska Philipsin johto näki siinä eniten parannettavaa. Tämän insinöörityön tutkimusmenetelmä oli laadullinen tutkimus, jolloin kaikkia Philips Oy Healthcaren asiakaspalvelijoita haastateltiin sekä myynnin että huollon puolelta. Haastateltavia oli yhteensä kuusi kappaletta ja heitä haastateltiin henkilökohtaisesti. Haastatteluista tehtyjen johtopäätöksien mukaan työtehtävät olivat erittäin epäselkeät. Tämän lisäksi puhelinrinkiin ei saatu sitovuutta ja sähköpostien hoitamisessa oli myös suuria vaikeuksia. Tutkimuksen tulokseksi saatiin uusi prosessikuvaus asiakaspalveluprosessiin, jossa on selitetty eri vaiheet ja tapahtumajärjestykset mahdollisimman selkeästi sekä ratkaisut sähköpostiin ja puhelinrinkiin. Tutkimustulosta eli prosessikuvaus annetaan työntekijöille työtehtävien selkeyttämiseksi, jolloin suurin hyöty aiheutuu työntekijöille työskennellessä