Showing papers by "University of Maryland, Baltimore County published in 1982"

Instructed versus shaped human verbal behavior: Interactions with nonverbal responding.

Abstract: Undergraduate students' presses on left and right buttons occasionally made available points exchangeable for money. Blue lights over the buttons were correlated with multiple random-ratio random-interval components; usually, the random-ratio schedule was assigned to the left button and the random-interval to the right. During interruptions on the multiple schedule, students filled out sentence-completion guess sheets (e.g., The way to earn points with the left button is to...). For different groups, guesses were shaped with differential points also worth money (e.g., successive approximations to "press fast" for the left button), or were instructed (e.g., Write "press slowly" for the left button), or were simply collected. Control of rate of pressing by guesses was examined in individual cases by reversing shaped or instructed guesses, by instructing pressing rates, and/or by reversing multiple-schedule contingencies. Shaped guesses produced guess-consistent pressing even when guessed rates opposed those characteristic of the contingencies (e.g., slow random-ratio and fast random-interval rates), whereas guesses and rates of pressing rarely corresponded after unsuccessful shaping of guesses or when guessing had no differential consequences. Instructed guesses and pressing were inconsistently related. In other words, when verbal responses were shaped (contingency-governed), they controlled nonverbal responding. When they were instructed (rule-governed), their control of nonverbal responding was inconsistent: the verbal behavior sometimes controlled, sometimes was controlled by, and sometimes was independent of the nonverbal behavior.

Ordeal by Fire: The Civil War and Reconstruction

Abstract: Part 1 The coming of war: American modernization, 1800-1860 the antebellum south the ideological conflict over slavery Texas, Mexico, and the compromise of 1850 filibusters, fugitives, and nativists Kansas and the rise of the Republican party the deepening crisis, 1857-1859 the critical year, 1859-1860 secession and the coming of war. Part 2 The Civil War: a brother's war - the upper South mobilizing for war the balance sheet of war the war at home and abroad the springtime of Northern hope Jackson and Lee strike back slavery and the war - Northern politics, 1861-1862 the first turning point - Antietam and emancipation the winter of northern discontent the second turning point - Gettysburg, Vicksburg, and Chattanooga war issues and politics in 1863 behind the lines wartime reconstruction and the freedpeople military stalemate, 1864 the third turning point - the election of 1864 the end of the Confederacy. Part 3 Reconstruction: the problems of peace the origins of \"racial\" reconstruction reconstruction and the crisis of impeachment the first grant administration the southern question, 1869-1872 social and economic reconstruction the retreat from reconstruction the new South.

Nicotiana chloroplast genome III. Chloroplast DNA evolution.

Abstract: Nicotiana chloroplast genomes exhibit a high degree of diversity and a general similarity as revealed by restriction enzyme analysis. This property can be measured accurately by restriction enzymes which generate over 20 fragments. However, the restriction enzymes which generate a small number (about 10) of fragments are extremely useful not only in constructing the restriction maps but also in establishing the sequence of ct-DNA evolution. By using a single enzyme, Sma I, a elimination and sequential gain of its recognition sites during the course of ct-DNA evolution is clearly demonstrated. Thus, a sequence of ct-DNA evolution for many Nicotiana species is formulated. The observed changes are all clustered in one region to form a “hot spot” in the circular molecule of ct-DNA. The mechanisms involved for such alterations are mostly point mutations but inversion and deficiency are also indicated. Since there is a close correlation between the ct-DNA evolution and speciation in Nicotiana a high degree of cooperation and coordination betwen organellar and nuclear genomes is evident.

Nicotiana chloroplast genome

Abstract: N. accuminata has a chloroplast genome of 171 Kb which is larger than 160 Kb reported for N. tabacum. A physical map of the former has been constructed by SalI, BglI, and PvuII enzymes in comparison with N. tabacum. They both share identical restriction map except in the extra segment of N. accuminata. This extra segment is located on the right-hand border of an inverted repeat in the large-single copy region of N. accuminata. It contains the following restriction sites: two for BglI and SmaI; three for SalI and XhoI. The size of inverted repeat measured by electron microscope is 22.67±0.78 Kb and 19.28±0.61 Kb for N. accuminata and N. tabacum, respectively. This is the first case where a larger inverted repeat region accompanied by a larger genome size was found among over 30 Nicotiana species studied thus far.

The Intracity Distribution of Services: A Multivariate Analysis

Abstract: Significant differences in the distribution of public resources among neighborhoods within the same municipality have been repeatedly reported in the literature. Previous researchers have generally concluded that these differences in the distribution of governmental benefits represent "unpatterned inequality" produced by idiosyncratic events and bureaucratic decision rules. This study of the distribution of municipal expenditures for public services in New York City comes to a very different conclusion. Municipal expenditures for social services (health, welfare, and education) increase with the dependency of district populations, which suggests a compensatory model of distribution. At the same time, municipal expenditures for property-related services (fire, sanitation) increase with tax revenues, which suggests a contributory model of distribution for these services. City expenditures for police services, however, are determined by both tax contributions and degree of dependence. These findings indicate that differences in the allocation of public resources in New York City are patterned by clearly recognizable distributional criteria.

Photosynthetic O2 Exchange Kinetics in Isolated Soybean Cells

Abstract: Light-dependent O(2) exchange was measured in intact, isolated soybean (Glycine max. var. Williams) cells using isotopically labeled O(2) and a mass spectrometer. The dependence of O(2) exchange on O(2) and CO(2) was investigated at high light in coupled and uncoupled cells. With coupled cells at high O(2), O(2) evolution followed similar kinetics at high and low CO(2). Steady-state rates of O(2) uptake were insignificant at high CO(2), but progressively increased with decreasing CO(2). At low CO(2), steady-state rates of O(2) uptake were 50% to 70% of the maximum CO(2)-supported rates of O(2) evolution. These high rates of O(2) uptake exceeded the maximum rate of O(2) reduction determined in uncoupled cells, suggesting the occurrence of another light-induced O(2)-uptake process (i.e. photorespiration).Rates of O(2) exchange in uncoupled cells were half-saturated at 7% to 8% O(2). Initial rates (during induction) of O(2) exchange in uninhibited cells were also half-saturated at 7% to 8% O(2). In contrast, steady-state rates of O(2) evolution and O(2) uptake (at low CO(2)) were half-saturated at 18% to 20% O(2). O(2) uptake was significantly suppressed in the presence of nitrate, suggesting that nitrate and/or nitrite can compete with O(2) for photoreductant.These results suggest that two mechanisms (O(2) reduction and photorespiration) are responsible for the light-dependent O(2) uptake observed in uninhibited cells under CO(2)-limiting conditions. The relative contribution of each process to the rate of O(2) uptake appears to be dependent on the O(2) level. At high O(2) concentrations (>/=40%), photorespiration is the major O(2)-consuming process. At lower (ambient) O(2) concentrations (

CHEMIOSMOTIC ATPase MECHANISMS

Abstract: Our main aim in this paper on the ion-motive ATPases is to comment on some realistic theoretical molecular models that may possibly be used to stimulate and guide experimental research into the molecular structure and function of these remarkable osmoenzymes (for reviews, see References 1-30). For reasons that have become increasingly relevant with the growth of knowledge of the detailed topology of biochemical systems over the last 25 year^,^^.^' we take the view that much better progress may be made on the basis of a biomechanical formality, in which we treat the ATPase molecules as miniature statistical-mechanical engines or machine^,^'.^^ than on the customary basis of a bioenergetic formality, which has encouraged us to regard the ATPase molecules as protein black boxes that can do anything thermodynamically feasible by appropriate conformatiopal prestidigitation, the secrets of which are not intended to be visible to the onlooker^.'^^^^ At the risk of spoiling the fun, we suggest that the conjuring bioenergetic fingers may be revealed by focusing attention on the balance of real interatomic vectorial forces that cause the relative motions of the chemical groups and ions involved in the ion-motive ATPase mechanism^.^^'^^,^^,^^ In the chemiosmotic processes catalyzed by the ion-motive ATPases, the reversible coupling between the chemical group-transfer process of ATP hydrolysis in the catalytic site domain and the osmotic process of ion translocation through the osmotic barrier domain in the osmoenzyme molecules may be abstractly accounted for by the balance of chemical and osmotic energy changes, according to the first law of thermodynamics. Thus, at equilibrium, the sum of the chemical and osmotic energy changes is zero. However, the abstract [scalar) energy changes are given by multiplying the vectorial forces on the chemical particles involved in the osmoenzyme-catalyzed process [including mobile components of the osmoenzyme molecule) by the colinear vectorial displacements that these particles undergo as the system turns over through its working catalytic configurational cycle, like a miniature engine.28.29.s6.37 The equilibrium condition of energy balance can accordingly be seen as a consequence of what we call the first law of molecular mechanics-the essentialIy Newtonian statistical-mechanical principle that the forces of action and reaction on every particle are equal and opposite.” In other words, the sum of the vectorial chemical and osmotic forces on each of the chemical groups and ions involved in the chemiosmotic process must be zer0?5,37 These considerations lead us to ask explicitly: What is the magnitude of the forces that must be transmitted between the chemical groups undergoing transfer and the ions undergoing translocation in the ion-motive ATPase molecules? And by what means, and how directly, are these forces transmitted? 584

The Effects of Megadoses of Selected B Complex Vitamins on Children with Hyperkinesis Controlled Studies with Long-Term Follow-up.

Abstract: One hundred children with hyperkinesis and cerebral dysfunction were given individual three-day trials of pharmacologic doses of thiamin, calcium pantothenate, pyridoxine, and placebo. When beneficial response was noted, a second week-long trial of vitamins was given, alternating with placebo, followed by long-term therapy. Two-thirds of the remaining children not responding to this schedule were then given pharmacologic doses of niacinamide, combinations of B-complex vitamins, or elimination diets.Eight children dramatically responded to pharmacologic doses of thiamin, of which four still require the vitamin either intermittently or continuously after four years. Nine children responded to 300 mg of pyridoxine; an additional 5 patients responded only after receiving larger doses. Only one child could be maintained on placebo.In subsequent trials, 11 responded to niacin or to combinations of B-complex vitamins with minerals. In a two-year follow-up, six children who had demonstrated no beneficial response...

Acoustical correlates of the perception of speech rate: an experimental investigation.

Abstract: The purpose of the study was to investigate the influence of vocal frequency and vocal intensity upon the perception of speech rate at three levels of actual speech rate. A single sample of spontaneous speech was electronically varied to produce nine stimulus segments that factorially combined three levels each of vocal frequency and intensity. The nine stimuli were recorded such that preceding each was the original segment that served as the standard with which each of the nine stimuli was to be compared. The speech rate of the set of nine stimulus pairs was then electronically altered to obtain a slow set, a moderate set, and a fast set, although the duration of every segment in the three sets was 20 seconds. The sets were rated by different groups of judges in terms of four 7-point scales that measured perceived speech rate, pitch, loudness, and perceived duration. The results indicate that the perception of speech rate is positively related to vocal frequency and intensity at each of the three actual speech rates, and suggest that these relationships are a function of the repeated experience of almost always hearing such covariation in spontaneously occurring speech.

The effects of redundant communications on the behavior of listeners: Does a picture need a thousand words?

Abstract: Using a referential communication paradigm, two types of, informative messages, contrastive and redundant, were compared developmentally in terms of their relative effects on the accuracy of listeners' responses as a function of task variables. Contrastive messages contained the minimal information necessary to distinguish a referent from a nonreferent. Redundant messages contained additional information. We predicted that redundant messages would be more effective than contrastive ones when the stimulus array was too complex for a listener to notice all aspects of it in the allotted time. Also manipulated were the order of presentation of the message and array and the delay between the two in order to determine how these factors would contribute to task complexity. Subjects were first-and third-graders and college students. The stimuli were drawings of cartoonlike figures. The results confirmed our predictions for the older subjects but not for the younger ones. The discussion of the data centered on why the picture-message sequence, was a more difficult sequence than the message-picture one for all age groups.

Toward the automated measurement of the type-A behavior pattern.

Abstract: Sixty-six structured interviews that were rated by Rosenman on a 5-point Type A/B behavior pattern scale, were scored by means of a semiautomated system for verbosity, voice volume and the temporal pacing of speech. A significant negative correlation obtained between interviewees' A/B ratings and their reaction-time scores; significant positive correlations obtained between their behavior type ratings and their voice volume and duration of vocalization scores. A regression equation consisting of reaction-time and voice volume scores correctly classified the A/B ratings of 89 percent of the interviewees. The significant correlations that were obtained between the interviewer's and the interviewees' speech patterns emphasize the need for standardizing the interviewer's style. Finally, the findings suggest that anxiety-arousal is a mediating variable in the relationship between Type-A behavior and coronary heart disease.

Children's Health Problems: Implications for Parental Labor Supply and Earnings

Abstract: A considerable amount of empirical research has been carried out on the economic impact of adults' health problems (e.g., Bartel and Taubman 1979; Luft 1975; Grossman and Benham 1974). A principal objective of the research has been to estimate the effects of these problems on the labor supply and earnings of illness victims. Policymakers and analysts have also expressed interest in these estimates as inputs to the process of allocating health sector resources among prevention and treatment programs for various diseases (Fuchs 1966; Fein 1958; Klarman 1965; Rice, Feldman, and White, 1976). By contrast, very few econometric studies have examined the economic impact of health problems on other family members. In particular, little is currently known about impacts on the spouses of illness victims or the parents of children with health problems. As a result, consideration of these impacts in policy analyses have been based on conjecture or, more frequently, ignored altogether. The present study focuses on the effect of chronic health problems and disabilities among children on parental labor supply and earnings. The severity of these problems, along with the long-term expense and difficulty of coping with them, raises the possibility of substantial impact on the psychological, physical, and economic health of the child's family. While relatively few children report such problems, a dramatic increase has occurred over the last decade. According to National Center for Health Statistics data (Table 8.1), the number of children with activity limitations due to chronic conditions nearly doubled from 1967 to 1978. The reasons for this increase are not presently known, but it seems likely that a variety of factors are involved, including more sophisticated medical therapies which increase survival rates for children born with physical impairments and the growing emphasis on "mainstreaming" and deinstitutionalization in public educational and social services programs.

Rate of environmental change and adaptation in the copepod eurytemora affinis

Abstract: The calanoid copepod Eurytemora affinis (Poppe) is a year-round inhabitat of the Chesapeake Bay, experiencing temperatures ranging from 0 C to 30 C. Since the generation time is only about three weeks at 15 C, much less than the seasonal cycle, individuals do not experience the entire range of temperatures. Adaptation to seasonal variation could be at least partly genetic. However, although seasonal differences in adaptation, measured as temperature tolerance, were found, these differences were not genetic (Bradley, 1981), in spite of the presence of a large amount of genetic variance in temperature tolerance in Eurytemora (Bradley, 1978b). The apparent absence of short-term selection effects raises the question of whether temperature tolerance can in fact be changed genetically by selection. Morrison and Milkman (1978) were able to alter heat resistance in Drosophila lines, especially in the downward direction and, earlier, Dallinger (1887) selected populations of flagellates for temperature tolerance over a seven-year period, beginning at 16 C. When the culture temperature reached 70 C the selected populations would no longer grow at 16 C, their original optimum. The results reported here show genetic adaptation to several constant and fluctuating temperatures. Based on other experiments, genetic response in Eurytemora seems to depend on the rate of environmental change.

Properties of the complexes formed by 1-anilinonaphthalene-8-sulfonate with phosphorylase kinase and calmodulin.

Abstract: Phosphorylase kinase contains four approximately equivalent binding sites for 1-anilinonaphthalene-8-sulfonate (1,8-ANS). Measurements of the time decay of fluorescence anisotropy have failed to give any indication of internal degrees of rotational freedom involving a significant portion of the tertiary structure. In the presence of 1 mM Ca2+, calmodulin binds one molecule of 1,8-ANS. No binding occurs in the absence of Ca2+. The binding is strongly temperature-dependent, a decrease in binding occurring with increasing temperature. Determinations of the time decay of fluorescence anisotropy indicate the presence of internal rotations, which become more important with increasing temperature. Complex formation between phosphorylase kinase and calmodulin reduces the binding of 1,8-ANS.

Evidence for contractile flexing of the gliding bacterium Flexibacter FS-1.

Abstract: Flexing movements have been described in a variety of gliding bacteria and cyanobacteria (blue-green algae)1–7. Flexing of trichomes (chains of cells) of the genera Oscillatoria and Beggiatoa was attributed8 to a “certain degree of elasticity”; it was concluded that there is no spontaneous flexibility. In contrast, observations of active flexing of free ends of otherwise immobilized Oscillatoria trichomes suggested9 that active contractions are involved. It has been proposed that flexing and gliding motility are powered by the same mechanism10. No organelles have been demonstrated irrefutably to be responsible for these movements, although several mechanistic hypotheses have been proposed11. I demonstrate here that flexing movements by the bacterium Flexibacter FS-1 require no more than one point of attachment by the cell to its substratum, which suggests that flexing may result from a unilateral, longitudinal contraction. As the same motility mechanism is thought to operate for both flexing and gliding, the latter may be powered by a contractile apparatus, at least in this species.