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Showing papers by "University of Maryland, Baltimore County published in 1986"


Journal ArticleDOI
21 Nov 1986-Science
TL;DR: Quantitations of messenger RNA and protein showed that the protein increase was greater than the messenger RNA increase in CV1 and HeLa cells, indicating that more than one mechanism was responsible for the trans-activation and that cell type-specific factors may determine the final level of trans- activation.
Abstract: The human T-lymphotropic retrovirus HTLV-III/LAV encodes a trans-activator that increases viral gene expression. We expressed this trans-activator in animal cells and studied its structural and functional characteristics. The putative trans-activator protein was immunoprecipitated from overproducing stable cell lines and shown to migrate as a 14-kilodalton polypeptide on sodium dodecyl sulfate-polyacrylamide gels. S1 nuclease mapping experiments showed that the trans-activator increases the levels of steady-state messenger RNA transcribed from the viral long terminal repeat promoter. Sequences within the R region of the HTLV-III/LAV long terminal repeat are essential for trans-activation. Quantitations of messenger RNA and protein showed that the protein increase was greater than the messenger RNA increase in CV1 and HeLa cells, indicating that more than one mechanism was responsible for the trans-activation and that cell type-specific factors may determine the final level of trans-activation.

254 citations


Journal ArticleDOI
TL;DR: Undergraduates' button presses occasionally produced points exchangeable for money, but performance was inconsistent with typical effects of the respective schedules with nonhuman organisms; it was plausible to conclude that the apparently contingency- Governed performances were instead rule-governed.
Abstract: Undergraduates' button presses occasionally produced points exchangeable for money. Left and right buttons were initially correlated with multiple random-ratio (RR) and random-interval (RI) components, respectively. During interruptions of the multiple schedule, students filled out sentence-completion guess sheets describing the schedules, and points were contingent upon the accuracy of guesses. To test for sensitivity to schedule contingencies, schedule components were repeatedly reversed between the two buttons. Pressing rates were consistently higher in ratio than in interval components even when feedback for guesses was discontinued, demonstrating sensitivity to the difference between ratio and interval contingencies. The question was whether this sensitivity was based directly on the contingencies or whether it was rule-governed. For two students, when multiple RR RI schedules were changed to multiple RI RI schedules, rates became low in both components of the multiple RI RI schedule; however, subsequent prevention of point deliveries for the first few responses in any component produced high rates in that component. For a third student, response rates became higher in the RI component that provided the lower rate of reinforcement. In each case, performance was inconsistent with typical effects of the respective schedules with nonhuman organisms; it was therefore plausible to conclude that the apparently contingency-governed performances were instead rule-governed.

142 citations


Journal ArticleDOI
TL;DR: Examples of frequency distributions, descriptive statistics, item-total correlations, and factor structure of the items within each scale and across scales within each of the areas assessed by the CPHI are discussed.
Abstract: The Communication Profile for the Hearing Impaired (CPHI) is a self-assessment inventory that provides 25 scores describing the Communication Performance, Communication Environment, Communication Strategies, and Personal Adjustment of hearing-impaired adults (Demorest & Erdman, 1986). Description of the content and measurement objective for each scale is given and an analysis of the psychometric properties of the 145 items in the CPHI is presented. Results are based on a sample of 433 active-duty military personnel tested at Walter Reed Army Medical Center during the final phase of CPHI development. Included are frequency distributions, descriptive statistics, item-total correlations, and factor structure of the items within each scale and across scales within each of the areas assessed by the CPHI. Applications of these data in clinical interpretation, construct validation, and further development of the CPHI scales are discussed.

109 citations


Journal ArticleDOI
TL;DR: It is shown that the AIS of the most severe extremity and spinal cord injury carry considerably more weight when predicting functional status at discharge and 6 months after discharge than do the A IS scores of injuries to any other body region, although the relative explanatory power of each type of injury varies with the nature of the functional disability.
Abstract: The utility of the Abbreviated Injury Scale (AIS), the most widely used anatomic scale for rating severity of injuries, and its derivative for assessing the combined effect of multiple injuries, the Injury Severity Score (ISS), were tested for their ability to predict functional disability at time of discharge from the hospital and 6 months after discharge. The ISS has been shown to correlate well with mortality and length of stay, but the relationship to levels of subsequent disability has not been examined. Five hundred and ninety-seven patients (aged 16-45 years) were interviewed at time of discharge and 6 months after discharge to ascertain functional disability along three dimensions: activities of daily living (ADL), instrumental activities of daily living (IADL), and mobility. The authors report on the relationship between severity and functional disability at time of discharge and 6 months after discharge for a subset of 473 patients who did not suffer a severe brain injury. The results show that the relationship between ISS and status at discharge and 6 months after discharge is not monotonically increasing, as it is with mortality and length of stay (LOS). Rather, the proportion of people with severe injuries who report limitations is lower than for those with moderately severe injuries as defined by the ISS. Further, it is shown that the AIS of the most severe extremity and spinal cord injury carry considerably more weight when predicting functional status at discharge and 6 months after discharge than do the AIS scores of injuries to any other body region, although the relative explanatory power of each type of injury varies with the nature of the functional disability and the time interval between the initial insult and assessment.

85 citations


Journal ArticleDOI
TL;DR: The invertebrate phyla illustrate fantastic diversity in design of either receptor type, and the best-studied groups are those with highly complex eyes, including the crustaceans, the molluscs, and some polychaete annelids.
Abstract: SYNOPSIS. In order for photoperiodic phenomena to be expressed by any animal, the organism must possess some sort of photoreceptor. This may be in the form of an eye or an extraocular receptor, and the invertebrate phyla illustrate fantastic diversity in design of either receptor type. While all the major invertebrate phyla possess photoreceptor organs of one type or another, the best-studied groups are those with highly complex eyes. These include the crustaceans, the molluscs, and some polychaete annelids. Many species in these groups possess eyes having extreme sensitivity, good spatial resolution, and in some cases multiple spectral channels. In a few taxa, the eyes are known to provide input to circadian oscillators, which suggests that they may also be employed for measurement of photoperiod. Extraocular photoreceptors include dermal and ganglionic sense organs, which also feed into circadian systems in numerous invertebrates, from cnidarians to molluscs and arthropods.

82 citations


Book ChapterDOI
01 Jan 1986
TL;DR: Since Dethier's experiments, many investigators have incorporated electrophysiology as an invaluable tool in conjunction with behavioral experiments for elucidating the chemosensory basis of behavior.
Abstract: The elegant behavioral experiments of Dethier (1955) on the chemosensory control of feeding in the blow fly set the stage for the first recordings of individual cell responses by Hodgson et al. (1955). The animals clearly accepted some substances and rejected others, leading Dethier to infer that one chemosensory cell coded for acceptance and another for rejection. When electrophysiological techniques became available, the resulting data indicated that more than one sensory cell mediates each of these behaviors. Further electrophysiological experimentation led to the elucidation of how salt-, sugar-, and water-sensitive cells can interact to regulate feeding behavior (Dethier, 1976). Since then many investigators have incorporated electrophysiology as an invaluable tool in conjunction with behavioral experiments for elucidating the chemosensory basis of behavior.

74 citations


Journal ArticleDOI
TL;DR: For instance, this article found that people yawn more during boring than interesting events and males performed longer yawns than females during the uninteresting than during the interesting stimuli, while females performed longer than males.
Abstract: The hypothesis that subjects yawn more while observing uninteresting than while observing interesting stimuli was tested by comparing the yawns produced by 17- to 19-year-old college freshmen while they observed a 30-min rock video, a complex and interesting audiovisual stimulus, and a 30-min color-bar test pattern without an audio track, an unchanging and very uninteresting stimulus. Significantly more and longer yawns were produced during the uninteresting than during the interesting stimulus and males performed longer yawns than females. The folk belief that people yawn more during boring than interesting events was confirmed.

68 citations


Journal ArticleDOI
TL;DR: The primary aim of the review is to attempt to define the mechanisms that lead to the initiation of the taste aversion response following exposure to ionizing radiation.

56 citations


Journal ArticleDOI
TL;DR: It is reported that taxol delays both the microtubule reorientation and reversal in transport direction in a concentration-dependent manner, and this and other presented data suggest that the polarity of the micro Tubule population within a melanophore confers direction on pigment transport.
Abstract: The cellular mechanisms used to direct translocating organelles are poorly understood. It is believed that the intrinsic structural polarity of microtubules may play a role in this process. We have examined the effects that differently oriented microtubules have upon the direction of pigment transport in surgically severed melanophore arms. In a previous paper (McNiven, M. A., M. Wang, and K. R. Porter, 1984, Cell, 37:753-765) we reported that after isolation, arms repolarized and reoriented their microtubules outward from their centers as if to form new "microcells." Pigment aggregation in these arms was toward a new focal point located at the arm centers. In this study we monitored pigment movement in isolated arms containing taxol-stabilized microtubules to test if the reversal in direction of pigment transport is dependent upon the repolarization of microtubules. We report that taxol delays both the microtubule reorientation and reversal in transport direction in a concentration-dependent manner. These and other presented data suggest that the polarity of the microtubule population within a melanophore confers direction on pigment transport.

55 citations


Journal ArticleDOI
TL;DR: It is concluded that an open coordination site is essential but not sufficient to catalyze the dismutation reaction and Manganous N-hydroxyethylethylenediaminetriacetate is oxidized by superoxide, but does not appear to have catalytic activity.

53 citations


Journal ArticleDOI
TL;DR: In an experimental analysis of the performance of verbal subjects, it is important to treat post-session reports about within-session covert verbal behavior as instances, not causes, of behavior.
Abstract: Experimental analyses of the performance of verbal subjects often include verbal reports, obtained during post-session interviews, about within-session covert verbal behavior (e.g., hypotheses about the contingencies). But such post-session reports are not necessarily accurate, and procedural details of how the samples were obtained are typically inadequate. Even when the post-session reports are accurate, the within-session hypotheses do not have the status of causes of within-session nonverbal performance. In an experimental analysis, it is important to treat such reports as instances, not causes, of behavior.

Journal ArticleDOI
TL;DR: In this in vitro system, chloroplast DNA synthesis initiated near the D-loop site and a yeast autonomously replicating (ARS) sequence and an ARC sequence, which promotes autonomous replication in Chlamydomonas, have been mapped within the flanking regions.
Abstract: Chloroplast DNA replication in Chlamydomonas reinhardtii is initiated by the formation of a displacement loop (D-loop) at a specific site. One D-loop site with its flanking sequence was cloned in recombinant plasmids SC3-1 and R-13. The sequence of the chloroplast DNA insert in SC3-1, which includes the 0.42-kilobase (kb) D-loop region, as well as 0.2 kb to the 5′ end and 0.43 kb to the 3′ end of the D-loop region, was determined. The sequence is A+T-rich and contains four large stem-loop stuctures. An open reading frame potentially coding for a polypeptide of 136 amino acids was detected in the D-loop region. One stem-loop structure and two back-to-back prokaryotic-type promoters were mapped within the open reading frame. The 5.5-kb EcoRI fragment cloned in R-13 contains the 1.05-kb SC3-1 insert and its flanking regions. A yeast autonomously replicating (ARS) sequence and an ARC sequence, which promotes autonomous replication in Chlamydomonas, have been mapped within the flanking regions [Vallet, J.-M. & Rochaix, J.-D. (1985) Curr. Genet. 9, 321-324]. Both R-13 and SC3-1 were active as templates in a crude algal preparation that supports DNA synthesis. In this in vitro system, chloroplast DNA synthesis initiated near the D-loop site.

Journal ArticleDOI
01 Jan 1986-Gene
TL;DR: expression of gamS+, but not gamS201, inhibited Escherichia coli RecBC nuclease in vivo; the criteria were inhibition of chromosomal DNA degradation after UV irradiation and plating of T4 gene 2- phages.

Journal ArticleDOI
TL;DR: In this paper, a case study of the way in which a group of children tacitly used ostracism to control and suppress the aggressive behavior of one member of the group was presented.

Journal ArticleDOI
TL;DR: This paper described an experimental course in communication offered to non-native English-speaking pharmacy students at the University of Maryland and reported the results of an evaluation of the course, which met weekly for one semester, was team-taught by a pharmacist specializing in communication for pharmacists and an ESL specialist.
Abstract: After presenting an overview of content-area ESL and English for specific purposes (ESP), this article describes an experimental course in communication offered to nonnative English-speaking pharmacy students at the University of Maryland and reports the results of an evaluation of the course. A combination of content- area ESL and ESP, the course, which met weekly for one semester, was team-taught by a pharmacist specializing in communication for pharmacists and an ESL specialist. Speech functions deemed necessary for effective oral communication by pharmacists in their professional settings were used as an organizing principle for the syllabus, which also provided for instruction in relevant linguistic structures, for instruction in communication principles and techniques, and for much active student participation. Although better evaluation measures are needed, student evaluations and comparison of the results on pre-and posttests of the Speaking Proficiency English Assessment Kit (Educational Testing Service, 1982a) suggest that the course was effective.

Journal ArticleDOI
TL;DR: In this article, the authors explored some substantive and methodological implications of using different data gathering techniques for measuring a couple's division of household labor and found that cross-method comparisons are closer for wives than husbands.
Abstract: This article explores some substantive and methodological implications of using different data gathering techniques for measuring a couple's division of household labor. Four measurement strategies, each requiring reports from both spouses, compared: the relative distribution approach, a weighted distribution, a time reconstruction method, and the activity log approach. Differences in average total estimates produced by the techniques are small, and regardless of the method used, the wife's contribution to housework is higher. Responsibility for domestic labor is suggested as one explanation for the finding that cross-method comparisons are closer for wives than husbands.

Journal ArticleDOI
TL;DR: From measurements of the efficiencies of radiationless energy transfer to the nitro derivatives of Tyr-99 and/or Tyr-138, it is concluded that Trp-19 is located in proximity to the C-terminal lobe of calmodulin in the complex.

Journal ArticleDOI
TL;DR: Using published research articles as a measure of output, the author ranks graduate schools' success in preparing economists as mentioned in this paper, and ranks the success of these schools' programs in the field of economics.
Abstract: Using published research articles as a measure of output, the author ranks graduate schools' success in preparing economists.

Journal ArticleDOI
TL;DR: One of the functions of high ascorbate in the aqueous humor of many primates including human beings may, therefore, be to protect the lens and other surrounding tissues against the toxic effects of active oxygen derivatives produced in situ under ambient, as well as under photochemical, conditions.


Journal ArticleDOI
TL;DR: The results provide direct experimental support for a mode of interaction between Cro and DNA, in which Cro buries its 2-fold related alpha-helices in consecutive DNA major grooves.

Journal ArticleDOI
TL;DR: Evidence is presented demonstrating that the amino acid compositions of the LS derived from the DNA sequence are related to the IEF cluster pattern, and a single charged residue is responsible for the difference in cluster pattern.
Abstract: Comparison of the DNA sequences of the rbcL gene from three Nicotiana species reveals a high degree of homology among the 1431 bp in the coding region. Only eight base pair differences are observed between N. otophora and N. tabacum, and between N. otophora and N. acuminata. Four base pair differences are observed between N. acuminata and N. tabacum. Most changes are in the third position of the codon resulting in only two amino acid alterations when N. otophora and N. acuminata are compared with N. tabacum. Evidence is presented demonstrating that the amino acid compositions of the LS derived from the DNA sequence are related to the IEF cluster pattern. A single charged residue is responsible for the difference in cluster pattern.


Journal ArticleDOI
TL;DR: The interaction of the carbocyanine dye Stains‐all with the Ca2+‐binding proteins calmodulin, troponin C, and parvalbumin has been monitored by means of absorption spectra and CD and a tentative model has been proposed to account for these observations.
Abstract: The interaction of the carbocyanine dye Stains-all with the Ca2+-binding proteins calmodulin, troponin C, and parvalbumin has been monitored by means of absorption spectra and CD. In the absence of Ca2+, complexes with Stains-all of all three proteins exhibit at high dye: protein mole ratios an intense J absorption band at 600–650 nm, which is associated with a characteristic CD spectrum. In the cases of calmodulin and troponin C, the J-band is progressively lost as the dye: protein ratio decreases and is replaced by bands of the γ and β types at 450–550 nm, which likewise give rise to characteristic CD spectra. For parvalbumin, only the J-band is observed; its intensity is undiminished at the lowest dye: protein ratios examined. In the presence of excess Ca2+ the J-band is lost for all three proteins. For calmodulin and troponin C it is replaced by σ- and β-bands; in the case of parvalbumin the bound dye is released. A tentative model has been proposed to account for these observations.

Journal ArticleDOI
TL;DR: Crystals of the lambda cro repressor complexed to a 17 base-pair synthetic binding site related to the OR3 operator have been obtained and diffraction patterns suggest that the cro-DNA complexes are arranged in an open hexagonal network with the DNA fragments stacked end-to-end.

Journal ArticleDOI
TL;DR: An optimal estimation scheme is presented, which determines the satellite attitude using the gyro readings and the star tracker measurements of a commonly used satellite attitude measuring unit, and results indicate that the scheme is more accurate and robust than extended Kalman filtering.

Journal ArticleDOI
TL;DR: The role of public elementary schooling in the development of mass education in nineteenth-century England has been investigated in a number of studies as discussed by the authors. But, the extent of education achieved with an initially active private market could perhaps have been markedly increased by the further development of public-elementary schooling.
Abstract: Considerable controversy exists about the role of public elementary schooling in the development of mass education in nineteenth-century England. Some recent accounts continue to support the long-standing view that the development of a public system of elementary schooling was the central force behind the rise in working-class educational attainment during the nineteenth century. Other accounts have suggested instead that this rise can be attributed to the growth in working-class demand for education and that this demand could have been met by private schooling. However, little attempt has been made to assess directly the effect of public elementary schooling on working-class educational attainment. Much of the debate has focused on the extent and quality of the private provision of working-class schooling in the first half of the nineteenth century. West and Laqueur have argued that an active private market financed in large part by fees was present. However, Hurt and Kiesling have argued that many of the schools West and Laqueur consider private were dame schools primarily providing childcare not instruction, or were aimed at a middle-class clientele, or were financed in part by subsidies from religious, philanthropic, or government sources. Although the state of the private schooling market in the first half of the nineteenth century is of interest as an indicator of the potential for the growth of working-class education under the circumstances of the time, it does not establish how much of the actual rise in school enrolment rates observed in the last half of the nineteenth century can be attributed to the development of a system of public elementary schooling. An initially limited private schooling market could have become much larger with extensive growth in working-class demand for schooling. On the other hand, the extent of education achieved with an initially active private market could perhaps have been markedly increased by the further development of public elementary schooling. 1 Those studies which have considered the relationship between the development of public elementary schooling and the rise of working-class education in the last half of the nineteenth century have tended to rely on post hoc,

Journal ArticleDOI
TL;DR: A method for determining the worth of a given alarm system by considering all factors which influence that worth is provided, which has been applied to several limited-scale engineering processes with rather significant success.

Journal ArticleDOI
01 Jan 1986
TL;DR: In this paper, the authors considered functions f given as exponential sums and obtained a (sharp) estimate for the asymptotic behavior of |C | as δar 0, which is uniform over classes of exponent sequences where μ k + 1 − μ k ≥ d > 0 and λ, d are bounded away from 0.
Abstract: We consider functions f given as exponential sums: f ( t )= Σ k c k exp [ iλ k t ] ( λ 0 = 0, λ − k =− λ k and λ k : = λ + μ k−1 2 for k = 1,2, …). With quadratic spacing of the exponents ( μ k ≈ dk ) it is classical that an arbitrarily small “window” (−δ,δ) for observation of f suffices to obtain the coefficients c = ( c k ); the coefficient map C : f → c is continuous from L 2 (− δ , δ ) to l 2 for any δ > 0. We consider the asymptotic behavior of | C | as δar 0, obtaining a (sharp) estimate: log | C | = O (1/ δ ). The estimate obtained is uniform over classes of exponent sequences where μ k +1 − μ k ≥ d >0 and λ, d are bounded away from 0. An application is given to boundary observation/control of a vibrating plate.

Journal ArticleDOI
TL;DR: Wall et al. as discussed by the authors, in collaboration with Jean Robin and Peter Laslett (eds), Family Forms in Historic Europe (1983) (Cambridge University Press, Cambridge, £39.50).
Abstract: Richard Wall in collaboration with Jean Robin and Peter Laslett (eds), Family Forms in Historic Europe (1983) (Cambridge University Press, Cambridge, £39.50).