Showing papers by "University of Oregon published in 1972"

X-Ray Fluorescence Yields, Auger, and Coster-Kronig Transition Probabilities

Abstract: The present status of the field of fluorescence yields, radiationless (Auger and Coster-Kronig) and radiative transition probabilities is summarized. Tables of experimental and theoretical results are included, and tables of "best values" of important quantities are presented.

The viscosity of magmatic silicate liquids; a model calculation

Abstract: The composition dependence of viscosity in binary silicate liquids is approximated by a linear equation of the form ln h = Si Xi Di, where h is the Newtonian viscosity coefficient, Xi is the mole fraction of oxide component i, and Di is an empirical constant associated component i over a restricted range of SiO 2 concentration. This relation has been extended to multicomponent silicate liquid systems, and a preferred set of viscosity measurements (2440 data points) has been used to evaluate Di constants at 50 degrees C intervals over the temperature range 1200 degrees to 1800 degrees C. Di values for the components SiO 2 , TiO 2 , FeO, MnO, MgO, CaO, SrO, BaO, Li 2 O, Na 2 O, K 2 O. KAlO 2 , NaAlO 2 , BaAl 2 O 4 , CaAl 2 O 4 , MgAl 2 O 4 , and MnAl 2 O 4 are given for mole fraction SiO 2 intervals 0.35 to 0.45, 0.45 to 0.55, 0.55 to 0.65, 0.65 to 0.75, and 0.75 to 0.81. The model may be used to calculate the viscosities of many natural magmatic liquids. A comparison of calculated viscosities with all the published data for molten rock and mineral systems shows a very satisfactory agreement over a range of viscosities from approximately 1 to 106 poises.

Pleasant events, activity schedules, and depressions.

Abstract: Three groups of 10 Ss, (depressed, psychiatric controls, and normal controls) were used. The 6s rated their moods and also indicated the number of \"pleasant\" activities engaged in each day over a period of 30 days. A significant association between mood and pleasant activities was found. There were large individual differences in regard to the magnitude of the correlation between mood and activity, but differences between groups failed to attain statistical significance. The results are interpreted as consistent with the major tenet of the behavioral theory of depression, that is, that there is an association between rate of positive reinforcement and intensity of depression.

Three-dimensional Structure of Thermolysin

Abstract: The electron density map of thermolysin indicates how the polypeptide chain is displaced throughout the overall shape of the molecule.

Control of synthesis of reaction center bacteriochlorophyll in photosynthetic bacteria

Abstract: — The ratio of total bacteriochlorophyll (BChl) to reaction center BChl has been determined in the wild-type and carotenoid-less mutants of Rhodopseudomonas spheroides and Rhodospirillum rubrum with various specific BChl contents. In wild-type R. spheroides the ratio increases as the specific BChl content increases; in the other strains the ratio is almost invariant. The ability of the wild-type of R. spheroides to alter the size of the photosynthetic unit is apparently correlated with its multi-component BChl spectrum. The amount of reaction center BChl relative to the amount of the longest wavelength component of the spectrum is constant. The variation in the size of the photosynthetic unit is due to variation in the amount of this component relative to total BChl. The size of the photosynthetic unit does not change as the specific BChl content decreases during growth under aerobic conditions of a culture grown previously under photosynthetic conditions.

Self-regulation in the modification of disruptive classroom behavior.

Abstract: This study compared self-regulation and external regulation procedures in the treatment of children's disruptive classroom behavior. After baseline data were collected, three of the four most disruptive children in each of 10 first- and second-grade classrooms received reinforcement for achieving low rates of disruptive behavior. The fourth child served as a control subject throughout the experiment. Two of the three experimental subjects were then taught to self-observe their own disruptive behavior. In the final reinforcement period, these subjects were given control over dispensing reinforcers to themselves, based on their self-collected behavioral data while subjects in the other experimental group continued with the externally managed reinforcement. In extinction, reinforcement was discontinued for all subjects, but one of the self-regulation subjects in each classroom continued overtly to self-observe. Results indicated that both reinforcement programs reduced disruptive behavior. The self-regulation procedures were slightly more effective in reducing disruptiveness than was the external regulation procedure, and this advantage persisted into extinction. These results suggest that self-regulation procedures provide a practical, inexpensive, and powerful alternative in dealing with disruptive behavior in children.

Optical activity of polypeptides and proteins.

Abstract: Using methods described in a previous publication the optical activity of a number of polypeptides and proteins has been calculated. The systems included the α-helix, the two β-structures, polyproline I, polyproline II, collagen and collagen models, and poly-N-methylalanine. In addition to these orderded structures, calculations were also performed on the α, β and nonperiodic regions of myoglobin, lysozyme, ribonuclease-S and β-chymotrypsin. The α and β structures in prteins differ from the polypeptide models by being very short and partially disordered. It is concluded that the 222-nm band of the α-helix is a good method for detecting helices in proteins but that the 207-and 191-nm bands of the helix will not fit a linear superposition model. The circular dichroism of the so-called β regions of proteins differs markedly from that for ideal β structure because of breakdownin symmetry. As a result estimates of β-structure in proteins based on polypeptide models are not likely to be quantitative. The theoretical methods give an adequate account of the optical activity of all the ordered polypeptides except polyproline II and collagen and (by inference) the nonperiodic chains in the various proteins. This difficulty is the remaining barrier to a complete theory of the optical activity of the polypeptide backbone in globular proteins.

Similarity grouping and peripheral discriminability under uncertainty.

Abstract: The effectiveness of rotated figures in producing similarity grouping corresponded to their peripheral discriminability under uncertainty in a patterned visual field--but not to their discriminability in an empty visual field. The results support the hypothesis that similarity grouping is a segregative process based on the response of the visual system to stimulus differences before attention narrows or focuses.

Atomic Vacancy Distributions Produced by Inner-Shell Ionization

Abstract: Average $L$- and $M$-shell-vacancy distributions produced in the deexcitation of atoms that have been singly ionized in the $K$ shell or one of the $L$ subshells are derived from a comprehensive set of available experimental and theoretical data on radiative- and Auger-transition rates. The data are supplemented by new calculations in $j\ensuremath{-}j$ coupling from nonrelativistic screened hydrogenic wave functions of the following radiationless transition rates: $K\ensuremath{-}LL$, $K\ensuremath{-}LM$, and $K\ensuremath{-}LN$ for selected elements with $20\ensuremath{\le}Z\ensuremath{\le}81$, and ${L}_{i}\ensuremath{-}MM$, ${L}_{i}\ensuremath{-}MX$, and ${L}_{i}\ensuremath{-}XY$ for $26\ensuremath{\le}Z\ensuremath{\le}93$. Experimental and theoretical data on Auger- and radiative-transition probabilities are critically compared. Auger-electron intensity ratios and $\frac{K{\ensuremath{\alpha}}_{2}}{K{\ensuremath{\alpha}}_{1}}$ and $\frac{K\ensuremath{\beta}}{K\ensuremath{\alpha}}$ x-ray intensity ratios from a best fit to experimental data are tabulated for even atomic numbers from 20 to 94. The probability, per initial $K$ vacancy, of vacancy production in each ${L}_{i}$ subshell is derived from experimental data and tabulated for $20\ensuremath{\le}Z\ensuremath{\le}94$; components due to Auger and x-ray transitions are listed separately. These probabilities agree well with purely theoretical vacancy distributions also derived here. The probability of $M$-shell-vacancy production in the decay of $K$ and ${L}_{i}$ vacancies is derived from theory and tabulated for selected atoms with $16\ensuremath{\le}Z\ensuremath{\le}93$.

Structure of thermolysin.

Abstract: Results of the chemical and X-ray analyses are combined to locate the active site and the calcium binding sites.

Industrial injuries of the back and extremities. Comprehensive evaluation--an aid in prognosis and management: a study of one hundred and eighty patients.

Abstract: Comprehensive evaluation and follow-up of a group of 180 industrially injured patients and a group of non-injured workers were carried out to ascertain the extent to which psychological, vocational, physical and other factors influenced the return to work of the injured patients. Significant differences were demonstrated in the psychological posture of back-injured, extremity-injured, and non-injured industrial workers. This study indicated that physical and psychological disability play an important role in the return to work of both extremity-injured and back-injured patients. Although a significant number of patients returned to work two or more years after injury, there was a general relationship between the duration of non-employment and the probability of return to work. In predicting return to work of the back-injured patient, psychological ratings by psychologists were superior to those made by physicians. These studies document the importance of psychological evaluation for optimum rehabilitation effort and suggest that the whole man concept is a useful, and perhaps necessary, consideration in the rehabilitation of the industrially injured workman. We believe that psychological evaluation is of value for patients who have failed to respond to usual therapy and in those being considered for spine fusion. Such evaluation is also useful in predicting the need for vocational retraining. Although the population represented in this study is a distinctive group, it is not unique. There are a large number of patients who exhibit similar characteristics. It seems unlikely that the concepts illustrated in this study are confined to the industrially-injured worker on compensation. They undoubtedly apply to other patients as well. Additional studies of the various factors influencing return to work following injury are needed.

Suppressed cell-mediated immunity in two adults with atopic dermatitis.

Abstract: Summary.— Tests of immune function over a 12-month period in a young woman and a young man with life-long atopic dermatitis showed depressed cell-mediated immunity (CMI) (delayed-type skin test unresponsiveness, inability to be sensitized to DNCB, diminished responsiveness of cultured lymphocytes to phytohaemagglutinin, enlarged subcutaneous lymph nodes without any cell-mediated immunopathology, but with the structure of a node involved in humoral antibody production). Direct immunofluorescence localized IgE in the germinal centres of these subcutaneous lymph nodes. No anti-immunoglobulin or anti-C3 complement fluorescent conjugates were localized in their involved or uninvolved skin. Cells corresponding to small-and medium-sized lymphocytes in concentrated peripheral leucocyte smears stained with FITC antiserum to human IgE. The woman's lymphocyte transformation suppression improved during a remission and relapsed during an exacerbation of the dermatitis.

Programming generalization and maintenance of treatment effects across time and across settings1

Abstract: Effects of three experimental and one control strategy were investigated in facilitating generalization and maintenance of treatment effects after two months in a token-economy classroom. At the conclusion of treatment, subjects were randomly assigned to one of three maintenance strategies or a control group and returned to their regular classrooms. The maintenance strategies were peer reprogramming, equating stimulus conditions between the experimental and regular classrooms, and teacher training in behavior management techniques. The maintenance strategies were implemented in the regular classroom for a two-month period and then terminated. Results indicated a powerful treatment effect produced by the token economy. Behavior maintenance effects following treatment were also obtained. The mean per cent appropriate behavior for the peer reprogramming and equating stimulus conditions strategies was significantly greater than the mean for the control subjects. The teacher training and control group means were not significantly different.

k-Homogeneous groups

Abstract: Theorem 1. Let G be a group k-homogeneous but not k-transitive on a finite set f2 of n points, where n>=2k. Then, up to permutation isomorphism, one of the following holds: (i) k = 2 and G < AFL(1, q) with n = q-= 3 (mod 4); (ii) k = 3 and PSL(2, q)<<_G<_PFL(2, q), where n 1 = q = 3 (rood 4); (iii) k = 3 and G=AGL(1, 8), AFL(1, 8) or AFL(1, 32); or (iv) k = 4 and G = PSL(2, 8), PFL(2, 8) or PFL(2, 32).

Work and Leisure: A Simplified Paradigm

Abstract: Definitions of leisure have been both exclusive and inclusive. Although different definitions have been used by various students of leisure, the nature of the differences has not always been clear....