ANTIBODY RESPONSE TO HOMOGRAFTS : VIII. RELATION OF MOUSE HEMAGGLUTININS AND CYTOTOXINS

Antigenic differences between certain inbred strains of mice which could not be revealed by hemagglutination techniques were readily disclosed by lymphocyte cytotoxicity. With an improved cytotoxicity test lymphotoxic titers were as high as 1:512 with non-hemagglutinating A anti CBA antisera. In other mouse strain combinations, a close parallel of both types of antibody activity was obtained. Though both activities were absorbed from antisera proportionally by erythrocytes and lymph node cells, 100 to 1000 times as many erythrocytes as lymphocytes were necessary to produce an equivalent reduction in antibody activity. These findings suggest that erythrocytes may possess only subthreshold quantities of certain antigens which are present in readily detectable levels on lymphocytes. Lymphocyte cytotoxicity therefore may assay a wider range of allogenic antigens than hemagglutination

Pump-probe differencing technique for cavity-enhanced, noise-canceling saturation laser spectroscopy

We present an experimental technique enabling mechanical-noise free, cavity-enhanced frequency measurements of an atomic transition and its hyperfine structure. We employ the 532nm frequency doubled output from a Nd:YAG laser and an iodine vapour cell. The cell is placed in a traveling-wave Fabry-Perot interferometer (FPI) with counter-propagating pump and probe beams. The FPI is locked using the Pound-Drever-Hall (PDH) technique. Mechanical noise is rejected by differencing pump and probe signals. In addition, this differenced error signal gives a sensitive measure of differential non-linearity within the FPI.Comment: 3 pages, 5 figures, submitted to Optics Letter

Applications of Infrared Photoacoustic Spectroscopy For Wood Samples

Various infrared (IR) spectroscopic techniques for the analysis of wood samples are briefly discussed. Theories and instrumentation of the newly developed photoacoustic spectroscopic (PAS) technique for measuring absorbance spectra of solids are presented. Some important applications of the PAS technique in wood science research are discussed. The application of the Fourier transform infrared-photoacoustic spectroscopic (FTIR-PAS) technique is demonstrated by three preliminary studies of different forms of wood samples

Quantitative Analysis of Radiation-Associated Parenchymal Lung Change

We present a novel classification system of the parenchymal features of radiation-induced lung damage (RILD). We developed a deep learning network to automate the delineation of five classes of parenchymal textures. We quantify the volumetric change in classes after radiotherapy in order to allow detailed, quantitative descriptions of the evolution of lung parenchyma up to 24 months after RT, and correlate these with radiotherapy dose and respiratory outcomes. Diagnostic CTs were available pre-RT, and at 3, 6, 12 and 24 months post-RT, for 46 subjects enrolled in a clinical trial of chemoradiotherapy for non-small cell lung cancer. All 230 CT scans were segmented using our network. The five parenchymal classes showed distinct temporal patterns. Moderate correlation was seen between change in tissue class volume and clinical and dosimetric parameters, e.g., the Pearson correlation coefficient was ≤0.49 between V30 and change in Class 2, and was 0.39 between change in Class 1 and decline in FVC. The effect of the local dose on tissue class revealed a strong dose-dependent relationship. Respiratory function measured by spirometry and MRC dyspnoea scores after radiotherapy correlated with the measured radiological RILD. We demonstrate the potential of using our approach to analyse and understand the morphological and functional evolution of RILD in greater detail than previously possible

Relativistic Treatment of Hypernuclear Decay

We compute for the first time the decay width of lambda-hypernuclei in a relativistic mean-field approximation to the Walecka model. Due to the small mass difference between the lambda-hyperon and its decay products---a nucleon and a pion---the mesonic component of the decay is strongly Pauli blocked in the nuclear medium. Thus, the in-medium decay becomes dominated by the non-mesonic, or two-body, component of the decay. For this mode, the lambda-hyperon decays into a nucleon and a spacelike nuclear excitation. In this work we concentrate exclusively on the pion-like modes. By relying on the analytic structure of the nucleon and pion propagators, we express the non-mesonic component of the decay in terms of the spin-longitudinal response function. This response has been constrained from precise quasielastic (p,n) measurements done at LAMPF. We compute the spin-longitudinal response in a relativistic random-phase-approximation model that reproduces accurately the quasielastic data. By doing so, we obtain hypernuclear decay widths that are considerably smaller---by factors of two or three---relative to existing nonrelativistic calculations.Comment: Revtex: 18 pages and 4 postscript figure

Astronomical X-Ray Optics Using Mono-Crystalline Silicon: High Resolution, Light Weight, and Low Cost

X-ray astronomy critically depends on X-ray optics. The capability of an X-ray telescope is largelydetermined by the point-spread function (PSF) and the photon-collection area of its mirrors, the same astelescopes in other wavelength bands. Since an X-ray telescope must be operated above the atmosphere inspace and that X-rays reflect only at grazing incidence, X-ray mirrors must be both lightweight and thin, bothof which add significant technical and engineering challenge to making an X-ray telescope. In this paper wereport our effort at NASA Goddard Space Flight Center (GSFC) of developing an approach to making an Xraymirror assembly that can be significantly better than the mirror assembly currently flying on the ChandraX-ray Observatory in each of the three aspects: PSF, effective area per unit mass, and production cost per uniteffective area. Our approach is based on the precision polishing of mono-crystalline silicon to fabricate thinand lightweight X-ray mirrors of the highest figure quality and micro-roughness, therefore, having thepotential of achieving diffraction-limited X-ray optics. When successfully developed, this approach will makeimplementable in the 2020s and 2030s many X-ray astronomical missions that are currently on the drawingboard, including sounding rocket flights such as OGRE, Explorer class missions such as STAR-X andFORCE, Probe class missions such as AXIS, TAP, and HEX-P, as well as large missions such as Lynx

Kinematic Alignment and Bonding of Silicon Mirrors for High-Resolution Astronomical X-Ray Optics

Optics for the next generation's high-resolution, high throughput x-ray telescope requires fabrication of well-formed lightweight mirror segments and their integration at arc-second precision. Recent advances in the fabrication of silicon mirrors developed at NASA/Goddard prompted us to develop a new method of mirror alignment and integration. In this method, stiff silicon mirrors are aligned quasi-kinematically and are bonded in an interlocking fashion to produce a "meta-shell" with large collective area. We address issues of aligning and bonding mirrors with this method and show a recent result of 4 seconds-of-arc for a single pair of mirrors tested at soft x-rays

Explorations using computer simulation to comprehend thematic apperceptive measurement of motivation

The new theory of motivation by Atkinson and Birch (1970), based on conceptual analysis of a change in activity, has been programmed to allow computer simulation of effects of differences in motivation on the stream of operant behavior. Simulation of conditions that exist when people who differ in strength of achievement motive write imaginative stories in response to a sequence of pictures shows that construct validity does not require internal consistency as traditionally supposed. The theoretically deduced differences in total time spent imagining achieving (instead of something else) can postdict input differences in motive strength (i.e., construct validity) even when there is little or no internal consistency reliability as indicated by Cronbach's (1951) alpha computed from theoretically deduced time spent imagining achievement in response to particular pictures. This general point has already been amply documented in 25 years of productive empirical research using TAT n Achievement. Now a definitive theoretical refutation of the repeated psychometric criticism of the method is provided. Those who have been moved “to dispel fantasies about fantasy-based measures of achievement motivation” (Entwistle, 1972) are invited, instead, to examine the shallow theoretical foudation of our traditional myths of measurement.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45359/1/11031_2005_Article_BF00997578.pd