Clonal analysis of a human antibody response. Quantitation of precursors of antibody-producing cells and generation and characterization of monoclonal IgM, IgG, and IgA to rabies virus.

We quantitated and characterized the changes in the human B cell repertoire, at the clonal level, before and after immunization with rabies virus. Moreover, we generated 10 monoclonal cell lines producing IgM, IgG, and IgA antibodies to the virus. We found that in healthy subjects, not previously exposed to the virus, nearly 2% of the circulating B lymphocytes were committed to the production of antibodies that bound the virus. These B cells expressed the surface CD5 molecule. The antibodies they produced were polyreactive IgM that displayed a relatively low affinity for the virus components (Kd, 1.0-2.4 x 10(-6) g/microliters). After immunization, different anti-virus (IgG and IgA) antibody-producing cells consistently appeared in the circulation and increased from less than 0.005% to greater than 10% of the total B cells committed to the production of IgG and IgA, respectively. Most of such B cells do not express CD5 and produce monoreactive antibodies of high affinity for rabies virus (Kd, 6.5 x 10(-9) to 1.2 x 10(-10) g/microliters). One of these IgG mAbs efficiently neutralized rabies virus in vitro and in vivo, as detailed elsewhere (Dietzschold, B., P. Casali, Y. Ueki, M. Gore, C. E. Rupprecht, A. L. Notkins, and H. Koprowski, manuscript submitted for publication). Hybridization experiments using probes specific for the different human V gene segment families revealed that cell precursors producing low affinity IgM binding to rabies virus utilized a restricted number of VH gene segments (i.e., only members of the VHIIIb subfamily), whereas cell precursors producing high affinity IgG and IgA to rabies virus utilized an assortment of different VH gene segments (i.e., members of the VHI, VHIII, VHIV, and VHVI families and VHIIIb subfamily). In conclusion, our studies show that EBV transformation in conjunction with limiting dilution technology and somatic cell hybridization techniques are useful methods for quantitating, at the B cell clonal level, the human antibody response to foreign Ags and for generating human mAbs of predetermined specificity and high affinity

Privacy regulation and online advertising

Advertisers use online customer data to target their marketing appeals. This has heightened consumers' privacy concerns, leading governments to pass laws designed to protect consumer privacy by restricting the use of data and by restricting online tracking techniques used by websites. We use the responses of 3.3 million survey takers who had been randomly exposed to 9,596 online display (banner) advertising campaigns to explore how privacy regulation in the European Union (EU) has influenced advertising effectiveness. This privacy regulation restricted advertisers' ability to collect data on Web users in order to target ad campaigns. We find that, on average, display advertising became far less effective at changing stated purchase intent after the EU laws were enacted, relative to display advertising in other countries. The loss in effectiveness was more pronounced for websites that had general content (such as news sites), where non-data-driven targeting is particularly hard to do. The loss of effectiveness was also more pronounced for ads with a smaller presence on the webpage and for ads that did not have additional interactive, video, or audio features

Response of \u3cem\u3eAxonopus catarinensis\u3c/em\u3e and \u3cem\u3eArachis pintoi\u3c/em\u3e to Shade Conditions

In the north-east of Argentina, there are more than 100,000 hectares of silvopastoral systems where trees, forages and livestock are combined with the goal to diversify income, reduce financial risk, obtain more profit and enhance environmental benefit (Cubbage et al. 2013). The rapid adoption of this production system by farmers has generated high demand for information on shade tolerant grass and legume forage species. Axonopus catarinensis is a native grass from Itajai Vally (Brazil) that was introduced to the north-east of Argentina 10 years ago; whereas Arachis pintoi is a sub-tropical legume (also native to Brazil) adapted to acid soils and tolerant of medium levels of shade (Fisher and Cruz 1994). Visual observation of these species in the field indicated high yields and acceptable tolerance to shade. A trial was subsequently carried out with the aim to quantify dry matter yield and nutritive quality of the species under different levels of shade for silvopastoral use

Lecture object: an architecture for archiving lectures on the Web

A new software architectural model for the archival of slide-based presentations on the Internet is proposed. This architecture is based on the concept of the "lecture object," a persistent format, independent of the lecture production and viewing technology. The work has been undertaken in the context of the Web Lecture Archive Project, a collaboration of the CERN HR Division Training and Development group and the University of Michigan, Ann Arbor. To date some 250 lectures have been archived and are viewable worldwide using standard Web browsers and freely available video player software

WLAP the Web Lecture Archive Project: The Development of a Web-Based Archive of Lectures, Tutorials, Meetings and Events at CERN and at the University of Michigan

This paper summarizes the results of a project to develop an electronic repository of "content-rich" lectures, talks, and training activities on the World-Wide Web. The work was carried out from July 1999 to July 2001 by a collaboration consisting of the University of Michigan ATLAS Collaboratory Project, the University of Michigan Media Union, the CERN HR Division, supported by the CERN IT and ETT Divisions and the CERN Academic and Summer Student Programs. In this document, we describe the software application chosen to synchronize the slide presentations to the video recordings, provide technical solutions to the various recording and archival challenges encountered during the project, and propose a set of research and development issues we feel merit further investigation. We also present the concept of a "Lecture Object" and suggest the adoption of standards so that lectures at multiple institutes can be seamlessly shared and incorporated into federated databases world-wide

A Quadratic Programming Approach to Quasi-Static Whole-Body Manipulation

This paper introduces a local motion planning method for robotic systems with manipulating limbs, moving bases (legged or wheeled), and stance stability constraints arising from the presence of gravity. We formulate the problem of selecting local motions as a linearly constrained quadratic program (QP), that can be solved efficiently. The solution to this QP is a tuple of locally optimal joint velocities. By using these velocities to step towards a goal, both a path and an inverse-kinematic solution to the goal are obtained. This formulation can be used directly for real-time control, or as a local motion planner to connect waypoints. This method is particularly useful for high-degree-of-freedom mobile robotic systems, as the QP solution scales well with the number of joints. We also show how a number of practically important geometric constraints (collision avoidance, mechanism self-collision avoidance, gaze direction, etc.) can be readily incorporated into either the constraint or objective parts of the formulation. Additionally, motion of the base, a particular joint, or a particular link can be encouraged/discouraged as desired. We summarize the important kinematic variables of the formulation, including the stance Jacobian, the reach Jacobian, and a center of mass Jacobian. The method is easily extended to provide sparse solutions, where the fewest number of joints are moved, by iteration using Tibshirani’s method to accommodate an l_1 regularizer. The approach is validated and demonstrated on SURROGATE, a mobile robot with a TALON base, a 7 DOF serial-revolute torso, and two 7 DOF modular arms developed at JPL/Caltech

Dynamical reentrance and geometry imposed quantization effects in Nb-AlOx-Nb Josephson junction arrays

In this paper, we report on different phenomena related to the magnetic properties of artificially prepared highly ordered (periodic) two-dimensional Josephson junction arrays (2D-JJA) of both shunted and unshunted Nb-AlOx-Nb tunnel junctions. By employing mutual-inductance measurements and using a high-sensitive bridge, we have thoroughly investigated (both experimentally and theoretically) the temperature and magnetic field dependence of complex AC susceptibility of 2D-JJA. We also demonstrate the use of the scanning SQUID microscope for imaging the local flux distribution within our unshunted arrays