Critical roles for the Bcl-3 oncoprotein in T cell-mediated immunity, splenic microarchitecture, and germinal center reactions

Chromosomal translocations of bcl-3 are associated with chronic B cell lymphocytic leukemias. Previously, we have shown that Bcl-3, a distinct member of the I kappa B family, may function as a positive regulator of NF-kappa B activity, although its physiologic roles remained unknown. To uncover these roles, we generated Bcl-3-deficient mice. Mutant mice, but not their littermate controls, succumb to T. gondii owing to failure to mount a protective T helper 1 immune response. Bcl-3-deficient mice are also impaired in germinal center reactions and T-dependent antibody responses to influenza virus. The results reveal critical roles for Bcl-3 in antigen-specific priming of T and B cells. Altered microarchitecture of secondary lymphoid organs in mutant mice, including partial loss of B cells, may underlie the immunologic defects. The implied role of Bcl-3 in maintaining B cells in wild-type mice may related to its oncogenic potential.     

Studies of the microwave resistivity of κ-(BEDT-TTF)2CU[N(CN)2]Cl

We have performed temperature dependent measurements of the surface impedance of κ-(BEDT-TTF)₂Cu[N(CN)₂]Cl in both directions, parallel and perpendicular to the highly conducting planes. In both orientations the microwave resistivity basically follows the dc behavior for T > 15 K: the crystal undergoes a broad metal-insulator transition at around 50 K. While there are no indications of superconductivity at ambient pressure found in the dc resistiviy and by ac susceptibility, the microwave resistivity clearly drops at 13 K and again at 5 K, indicating two supercondcuting phases. When pressure is applied by embedding it in grease, only the well known superconducting phase transition at T_c= 13 K remains.     

Shadow-zone diffraction patterns for triangular obstacles

A simplified ray-optics (scalar) theory is presented which can be used to calculate interference patterns in the shadow of a diffracting obstacle whose transverse profile consists of two or more straight line segments. The theory is applicable when the pathlength-to-wavelength ratio is large and the diffraction angle is small, conditions typical of terrestrial microwave diffraction links over conical mountain peaks. Scale-model test results show that the theory quite accurately predicts the pattern structure.     

Combined effects of oxygen and hydrogen on tensile properties of a Nb-10 at. Pct V alloy

The addition of oxygen to a Nb-10 at. pct V alloy results in linear hardening and an increase in the strain rate sensitivity with increasing concentration. Hydrogen induces a minimum in the reduction of area, a temperature dependent hardening, and a maximum in the strain rate sensitivity of Nb-10V at ≈150 K. The strengthening and accompanying low temperature softening by hydrogen below 150 K are explained by a strain-induced ordering of hydrogen atoms around dislocations. Indications are, however, that hydrogen interacts only weakly, if at all, with the oxygen. A ductility minimum and associated return-of-ductility due to hydrogen are attributed to the high strain rate that occurs in the necked region during deformation.     

The Simultaneous Determination of Plant and Leased Warehouse Capacities for a Firm Facing Uncertain Demand in Several Regions

For each of several regions a firm has forecasted a probability distribution of future annual demand, and the plan is to build a single production facility to serve this demand. Each region is served by a simple leased warehouse with a lease cost which is a linear function of capacity. Any regional demand exceeding warehouse capacity is lost. The cost of building the plant is a nonlinear function of its capacity, and the unit cost of producing the product and supplying it to a region is constant. We develop an efficient algorithm based on the Kuhn-Tucker conditions for simultaneously determining the plant and warehouse capacities which will maximize the firm's expected profit. The paper includes a numerical example demonstrating the use of this algorithm.     

Nuclear Data Sheets for A = 116

The 1960 version of the Nuclear Data Sheets for A = 116 has been revised on the basis of experimental data received before August 1973, with some later modifications received via private communications. Experimental data concerning the nuclear structure of ten isotopes were compiled and used in the construction of the level schemes and J^π-assignments.     

Fusion reactor first-wall cooling for very high energy fluxes

A study has been made of the feasibility of a protective first-wall shield between the plasma and the containment vessel for early experimental controlled thermonuclear fusion machines. The proposed first-wall shield is a water-cooled array of thin-walled tubes designed to take very high local energy fluxes originating from the neutral beam injectors. Detailed computer calculations reveal that heat flux capabilities of 3300 W/cm² are possible with first-wall shield sections made up of tubes 1 m long of Ta-10W alloy (with tubes of 10 mm i.d. and tube wall thickness of 0.5 mm) with a structural safety factor of about four. Required pumping powers on the order of 1 MW/m² of first-wall area exposed to these high energy fluxes are predicted for flow in the non-boiling regime. If operation in the subcooled nucleate boiling regime can be achieved without oscillations or instabilities, the required pumping power is shown to decrease by about an order of magnitude.     

The V-VO phase system

A phase diagram is proposed for the V-VO system based on melting point determinations, differential thermal analyses, metallographic observations, and X-ray parametric measurements. A eutectic reaction occurs at 1640°C and 29 at. pct O. The intermediate phases V₉O and V₂O form peritectoidally at 510° and 1185°C, respectively, while V₄O forms by a peritectic reaction at 1665°C. The VO phase melts congruently at 1790°C. The terminal solubility of oxygen in vanadium increases from 3.2 at. pct at room temperature to a maximum of 17.0 at. pct at the peritectic temperature. There is also extensive solid solubility associated with each of the intermediate phases. Two martensite-like phases form in alloys in the composition range 6 to 9 at. pct O upon quenching from above the 510°C peritectoid horizontal.