98 research outputs found
Optimal Investment-Consumption Problem with Constraint
In this paper, we consider an optimal investment-consumption problem subject to a closed convex constraint. In the problem, a constraint is imposed on both the investment and the consumption strategy, rather than just on the investment. The existence of solution is established by using the Martingale technique and convex duality. In addition to investment, our technique embeds also the consumption into a family of fictitious markets. However, with the addition of consumption, it leads to nonreflexive dual spaces. This difficulty is overcome by employing the so-called technique of \relaxation-projection" to establish the existence of solution to the problem. Furthermore, if the solution to the dual problem is obtained, then the solution to the primal problem can be found by using the characterization of the solution. An illustrative example is given with a dynamic risk constraint to demonstrate the method
Revised radioreceptor assay for beta 2-adrenoceptors expressed on peripheral mononuclear leukocytes
Peripheral mononuclear leukocytes (pMNL) bear a population of beta 2-adrenoceptors. Radioreceptor assays with (-)-125Iodocyanopindolol (125I-CYP) are often used to determine the expression of these hormone receptors under physiological and pathological conditions. Doubts on the occurrence of just one class of binding sites as well as the availability of new laboratory equipment prompted us to revise the procedure employed for investigation of these receptors. pMNL were harvested from venous human blood by density centrifugation with LymphopaqueR, LymphoprepR, or FicollR yielding immunologically distinct pMNL fractions. Receptor binding assays were performed semi-automatically with 125I-CYP in the range from 0.6-600 pmol/l. Analysis of the data (modified affinity spectra, Scatchard plot) revealed two classes of binding sites (high- and low affinity binding). The binding isotherms were sigmoidal in the concentration range from 0.6-3.0 pmol/l. Parameters estimated for the high affinity binding site may vary by a factor of 10, depending on the mathematical model employed
Early high-affinity neutralizing anti-viral IgG responses without further overall improvements of affinity.
Affinity maturation of IgG antibodies in adaptive immune responses is a well-accepted mechanism to improve effector functions of IgG within 2 weeks to several months of antigen encounter. This concept has been defined mainly for IgG responses against chemically defined haptens. We have evaluated this concept in a viral system and analyzed neutralizing IgG antibody responses against vesicular stomatitis virus (a close relative of rabies virus) with a panel of monoclonal antibodies obtained early (day 6 or 12) and late (day 150) after hyperimmunization. These neutralizing IgG antibodies recognize a single major antigenic site with high affinities (Ka of 10(8)-10(10) liter.mol-1) and with rapid on-rates already on day 6 of a primary response and with no evidence for further antigen dose- and time-dependent overall improvement of affinity. This type of IgG response is probably representative for viruses or bacterial toxins which are crucially controlled by neutralizing antibodies
Early high-affinity neutralizing anti-viral IgG responses without further overall improvements of affinity.
Affinity maturation of IgG antibodies in adaptive immune responses is a well-accepted mechanism to improve effector functions of IgG within 2 weeks to several months of antigen encounter. This concept has been defined mainly for IgG responses against chemically defined haptens. We have evaluated this concept in a viral system and analyzed neutralizing IgG antibody responses against vesicular stomatitis virus (a close relative of rabies virus) with a panel of monoclonal antibodies obtained early (day 6 or 12) and late (day 150) after hyperimmunization. These neutralizing IgG antibodies recognize a single major antigenic site with high affinities (Ka of 10(8)-10(10) liter.mol-1) and with rapid on-rates already on day 6 of a primary response and with no evidence for further antigen dose- and time-dependent overall improvement of affinity. This type of IgG response is probably representative for viruses or bacterial toxins which are crucially controlled by neutralizing antibodies
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