Purification and properties of a plant Agglutinin

Thesis (M.A.)--Boston UniversityThis study involved work with extracts of the seeds of Bauhinia purpurea alba, in which an N specific lectin was found by Mäkelä (37) and Boyd and McMaster (16). There were two main purposes in mind. First, to see if the lectin could be of practical use as a typing sera; and secondly, to get some insight into its chemical make-up. After working out a purification method and a method for checking the agglutinating power of the lectin, the lectin was tested against several small samples. The writer then tested this lectin against 90 random blood samples. The lectin disagreed with rabbit anti-N in one case -- the lectin typed one MN as an M. There is as yet no known reason for this difference, so it would seem that one could not use the lectin as a typing sera at the present time. The lectin was treated with formaldehyde and lost all its activity as a result. Erythrocytes were treated with an enzyme, ficin, and were then reacted with the lectin. The results showed an increase in the titer of the lectin, and the specificity of the lectin was lost. The freezing of a sample of the lectin for four months resulted in the loss of some of its activity. It remained specific, however. Upon dialyzing the crude extract against saline or water, the substances (Y) that remained behind in the membrane became nonspecific. This showed that there were at least two parts to the extract, one of large molecular weight because it would not pass through the membrane, and the other smaller in size because it would pass through the membrane. The substance that passed through the membrane was called X. By dialyzing the crude extract against distilled water and lyophilizing the distilled water, a substance was found which gave the reaction of a sugar and also seemed to have either or both glucosamine and galactosamine present. Since X showed the presence of reducing sugars and could be shown to inhibit Y against the M site on erythrocytes (see Table 7), it was thought that some sugars should be tested against Y to see if any of them would be able to inhibit Y. The same sugars were also tested against the lectin (Table 5). It was found that none of the sugars had any effect on the lectin; but raffinose, melibiose, and galactose all were found to inhibit Y (Table 8). It has also been shown by other workers (13) that lactose will inhibit Y. The inhibition of the sugars against lectin and Y were run in three ways. The first was the usual inhibition method where the inhibiting substance (sugar, in this case) is placed with the substance to be inhibited (Y) and incubated for one hour. Then the appropriate erythrocyte was added. The second method was to place erythrocytes, Y, and sugar all in the same tube at the same time. The third was to incubate sugar and erythrocytes together and then add Y. The results are given in Table 9. It was found by the writer that Method 2 was the best. This agrees with Krüpe as cited in Mäkelä (37) who states that if an appropriate sugar is added to erythrocytes that are agglutinated by a lectin, the lectin will leave the erythrocytes and pick up the sugar. This is shown by the breaking up of the clumps of erythrocytes. The sugars that would inhibit Y were tried against adsorbed rabbit sera, both anti-M and N. The sugars showed no effect against the rabbit sera. The writer feels that the lectin may not be as specific as the rabbit sera; thus, these inhibiting sugars may only be closely related to the true configuration of the M site

The polarographic determination of cobalt in potassium iodide

Not available.Donald Lee KiserNot ListedNot ListedMaster of ScienceDepartment Not ListedCunningham Memorial Library, Terre Haute, Indiana State University.isua-thesis-1961-kiserMastersTitle from document title page. Document formatted into pages: conatins 48p. : ill. Includes bibliography

Electron and Ion Acceleration in Relativistic Shocks with Applications to GRB Afterglows

We have modeled the simultaneous first-order Fermi shock acceleration of protons, electrons, and helium nuclei by relativistic shocks. By parameterizing the particle diffusion, our steady-state Monte Carlo simulation allows us to follow particles from particle injection at nonthermal thermal energies to above PeV energies, including the nonlinear smoothing of the shock structure due to cosmic-ray (CR) backpressure. We observe the mass-to-charge (A/Z) enhancement effect believed to occur in efficient Fermi acceleration in non-relativistic shocks and we parameterize the transfer of ion energy to electrons seen in particle-in-cell (PIC) simulations. For a given set of environmental and model parameters, the Monte Carlo simulation determines the absolute normalization of the particle distributions and the resulting synchrotron, inverse-Compton, and pion-decay emission in a largely self-consistent manner. The simulation is flexible and can be readily used with a wide range of parameters typical of gamma-ray burst (GRB) afterglows. We describe some preliminary results for photon emission from shocks of different Lorentz factors and outline how the Monte Carlo simulation can be generalized and coupled to hydrodynamic simulations of GRB blast waves. We assume Bohm diffusion for simplicity but emphasize that the nonlinear effects we describe stem mainly from an extended shock precursor where higher energy particles diffuse further upstream. Quantitative differences will occur with different diffusion models, particularly for the maximum CR energy and photon emission, but these nonlinear effects should be qualitatively similar as long as the scattering mean free path is an increasing function of momentum.Comment: Accepted for publication in MNRA

Competition, Consumer Welfare, and the Social Cost of Monopoly

Conventional deadweight loss measures of the social cost of monopoly ignore, among other things, the social cost of inducing competition and thus cannot accurately capture the loss in social welfare. In this Article, we suggest an alternative method of measuring the social cost of monopoly. Using elements of general equilibrium theory, we propose a social cost metric where the benchmark is the Pareto optimal state of the economy that uses the least amount of resources, consistent with consumers' utility levels in the monopolized state. If the primary goal of antitrust policy is the enhancement of consumer welfare, then the proper benchmark is Pareto optimality, not simply competitive markets. We discuss the implications of our approach for antitrust law as well as how our methodology can be used in practice for allegations of monopoly power given a history of price-demand observations.Monopoly power, Antitrust economics, Applied general equilibrium

Mobile Image Ratiometry: A New Method for Instantaneous Analysis of Rapid Test Strips

Here we describe Mobile Image Ratiometry (MIR), a new method for the automated quantification of standardized rapid immunoassay strips using consumer-based mobile smartphone and tablet cameras. To demonstrate MIR we developed a standardized method using rapid immunotest strips directed against cocaine (COC) and its major metabolite, benzoylecgonine (BE). We performed image analysis of three brands of commercially available dye-conjugated anti-COC/BE antibody test strips in response to three different series of cocaine concentrations ranging from 0.1 to 300 ng/ml and BE concentrations ranging from 0.003 to 0.1 ng/ml. These data were then used to create standard curves to allow quantification of COC/BE in biological samples. MIR quantification of COC and BE proved to be a sensitive, economical, and faster alternative to more costly methods, such as gas chromatography-mass spectrometry, tandem mass spectrometry, or high pressure liquid chromatography. MIR is a valuable tool that provides instant data acquisition, tracking and analysis for the emerging field of mobile platform informatics (MPI)

Characterization and snubbing of a bidirectional MCT in a resonant ac link converter

The MOS-Controlled Thyristor (MCT) is emerging as a powerful switch that combines the better characteristics of existing power devices. A study of switching stresses on an MCT switch under zero voltage resonant switching is presented. The MCT is used as a bidirectional switch in an ac/ac pulse density modulated inverter for induction motor drive. Current and voltage spikes are observed and analyzed with variations in the timing of the switching. Different snubber circuit configurations are under investigation to minimize the effect of these transients. The results will be extended to study and test the MCT switching in a medium power (5 hp) induction motor drive