Showing papers by "Michigan State University published in 1984"

Reciprocal Teaching of Comprehension-Fostering and Comprehension-Monitoring Activities

Abstract: Two instructional studies directed at the comprehension-fostering and comprehension-monitoring activities of seventh grade poor comprehenders are reported. The four study activities were summarizing (self-review), questioning, clarifying, and predicting. The training method was that of reciprocal teaching, where the tutor and students took turns leading a dialogue centered on pertinent features of the text. In Study 1, a comparison between the reciprocal teaching method and a second intervention modeled on typical classroom practice resulted in greater gains and maintenance over time for the reciprocal procedure. Reciprocal teaching, with an adult model guiding the student to interact with the text in more sophisticated ways, led to a significant improvement in the quality of the summaries and questions. It also led to sizable gains on criterion tests of comprehension, reliable maintenance over time, generalization to classroom comprehension tests, transfer to novel tasks that tapped the trained skills of...

The ontogenetic niche and species interactions in size-structured populations

Abstract: Body size is manifestly one of the most important attributes of an organism from an ecological and evolutionary point of view. Size has a predominant influence on an animal's energetic requirements, its potential for resource exploitation, and its susceptibility to natural enemies. A large literature now exists on how physiological, life history, and population parameters scale with body dimensions (24, 131). The ecological literature on species interactions and the structure of animal communities also stresses the importance of body size. Differences in body size are a major means by which species avoid direct overlap in resource use (153), and size-selective predation can be a primary organizing force in some communities (20, 70). Size thus imposes important constraints on the manner in which an organism interacts with its environment and influences the strength, type, and symmetry of interactions with other species (152, 207). Paradoxically, ecologists have virtually ignored the implications of these observations for interactions among species that exhibit size-distributed populations. For instance, it has been often suggested that competing species

Validity and Utility of Alternative Predictors of Job Performance

Abstract: Meta-analysis of the cumulative research on various predictors of job performance shows that for entry-level jobs there is no predictor with validity equal to that of ability, which has a mean validity of .53. For selection on the basis of current job performance, the work sample test, with mean validity of .54, is slightly better. For federal entry-level jobs, substitution of an alternative predictor would cost from $3.12 billion (job tryout) to $15.89 billion per year (age). Hiring on ability has a utility of $15.61 billion per year, but affects minority groups adversely. Hiring on ability by quotas would decrease this utility by 5%. A third strategy—using a low cutoff score—would decrease utility by 83%. Using other predictors in conjunction with ability tests might improve validity and reduce adverse impact, but there is as yet no data base for studying this possibility.

Production Frontiers and Panel Data

Abstract: This article considers estimation of a stochastic frontier production function-the type introduced by Aigner, Lovell, and Schmidt (1977) and Meeusen and van den Broeck (1977). Such a production frontier model consists of a production function of the usual regression type but with an error term equal to the sum of two parts. The first part is typically assumed to be normally distributed and represents the usual statistical noise, such as luck, weather, machine breakdown, and other events beyond the control of the firm. The second part is nonpositive and represents technical inefficiencythat is, failure to produce maximal output, given the set of inputs used. Realized output is bounded from above by a frontier that includes the deterministic part of the regression, plus the part of the error representing noise; so the frontier is stochastic. There also exist socalled deterministic frontier models, whose error term contains only the nonpositive component, but we will not consider them here (e.g., see Greene 1980). Frontier models arise naturally in the problem of efficiency measurement, since one needs a bound on output to measure efficiency. A good survey of such production functions and their relationship to the measurement of productive efficiency was given by F0rsund, Lovell, and Schmidt (1980).

Metaanalyses of validity studies published between 1964 and 1982 and the investigation of study characteristics

Abstract: Review and metaanalyses of published validation studies for the years 1964-1982 of Journal of Applied Psychology and Personnel Psychology were undertaken to examine the effect of (1) research design; (2) criterion used; (3) type of selection instrument used; (4) occupational group studies; and (5) predictor-criterion combination on the level of observed validity coefficients. Results indicate that concurrent validation designs produce validity coefficients roughly equivalent to those obtained in predictive validation designs and that both of these designs produce higher validity coefficients than does a predictive design which includes use of the selection instrument. Of the criteria examined, performance rating criteria generally produced lower validity coefficients than did the use of other more “objective” criteria. In comparing the validities of various types of predictors, it was found cognitive ability tests were not superior to other predictors such as assessment centers, work samples, and supervisory/peer evaluations as has been found in previous metaanalytic work. Personality measures were clearly less valid. Compared to previous validity generalization work, much unexplained variance in validity coefficients remained after corrections for differences in sample size. Finally, the studies reviewed were deficient for our purposes with respect to the data reported. Selection ratios, standard deviations, reliabilities, predictor and criterion intercorrelations were rarely and inconsistently reported. There are also many predictor-criterion relationships for which very few validation efforts have been undertaken.

Membrane protein damage and repair: Selective loss of a quinone-protein function in chloroplast membranes.

Abstract: A loss of electron transport capacity in chloroplast membranes was induced by high-light intensities (photoinhibition). The primary site of inhibition was at the reducing side of photosystem II (PSII) with little damage to the oxidizing side or to the reaction center core of PSII. Addition of herbicides (atrazine or diuron) partially protected the membrane from photoinhibition; these compounds displace the bound plastoquinone (designated as QB), which functions as the secondary electron acceptor on the reducing side of PSII. Loss of function of the 32-kilodalton QB apoprotein was demonstrated by a loss of binding sites for [14C]atrazine. We suggest that quinone anions, which may interact with molecular oxygen to produce an oxygen radical, selectively damage the apoprotein of the secondary acceptor of PSII, thus rendering it inactive and thereby blocking photosynthetic electron flow under conditions of high photon flux densities.

Ionophores: their effect on production efficiency and mode of action

Abstract: Carboxylic polyether ionophores, when fed to growing ruminants improve efficiency of production. This review summarizes the observed effects of ionophores on the ruminal fermentation and the host animal. The effect of ionophores on prokaryotic and eukaryotic cells is described and this knowledge is then utilized to explain many of the observed ionophore effects on the rumen fermentations and host gastrointestinal physiology.

Relational Messages Associated with Nonverbal Behaviors.

Abstract: Based on the assumptions that relational messages are multidimensional and that they are frequently communicated by nonverbal cues, this experiment manipulated five nonverbal cues -eye contact, proximity, body lean, smiling, and touch - to determine what meanings they convey along four relational message dimensions. Subjects (N= 150) observed 2 out of 40 videotaped conversational segments in which a male-female dyad presented various combinations of the nonverbal cues. High eye contact, close proximity, forward body lean, and smiling all conveyed greater intimacy, attraction, and trust. Low eye contact, a distal position, backward body lean, and the absence of smiling and touch communicated greater detachment. High eye contact, close proximity, and smiling also communicated less emotional arousal and greater composure, while high eye contact and close proximity alone conveyed greater dominance and control. Effects of combinations of cues and sex-differences are also reported.

Isolation and partial characterization of bacteria in an anaerobic consortium that mineralizes 3-chlorobenzoic Acid.

Abstract: A methanogenic consortium able to use 3-chlorobenzoic acid as its sole energy and carbon source was enriched from anaerobic sewage sludge. Seven bacteria were isolated from the consortium in mono- or coculture. They included: one dechlorinating bacterium (strain DCB-1), one benzoate-oxidizing bacterium (strain BZ-2), two butyrate-oxidizing bacteria (strains SF-1 and NSF-2), two H(2)-consuming methanogens (Methanospirillum hungatei PM-1 and Methanobacterium sp. strain PM-2), and a sulfate-reducing bacterium (Desulfovibrio sp. strain PS-1). The dechlorinating bacterium (DCB-1) was a gram-negative, obligate anaerobe with a unique "collar" surrounding the cell. A medium containing rumen fluid supported minimal growth; pyruvate was the only substrate found to increase growth. The bacterium had a generation time of 4 to 5 days. 3-Chlorobenzoate was dechlorinated stoichiometrically to benzoate, which accumulated in the medium; the rate of dechlorination was ca. 0.1 pmol bacterium day. The benzoate-oxidizing bacterium (BZ-2) was a gram-negative, obligate anaerobe and could only be grown as a syntroph. Benzoate was the only substrate observed to support growth, and, when grown in coculture with M. hungatei, it was fermented to acetate and CH(4). One butyrate-oxidizing bacterium (NSF-2) was a gram-negative, non-sporeforming, obligate anaerobe; the other (SF-1) was a gram-positive, sporeforming, obligate anaerobe. Both could only be grown as syntrophs. The substrates observed to support growth of both bacteria were butyrate, 2-dl-methylbutyrate, valerate, and caproate; isobutyrate supported growth of only the sporeforming bacterium (SF-1). Fermentation products were acetate and CH(4) (from butyrate, isobutyrate, or caproate) or acetate, propionate, and CH(4) (from 2-dl-methylbutyrate or valerate) when grown in coculture with M. hungatei. A mutualism among at least the dechlorinating, benzoate-oxidizing, and methane-forming members was apparently required for utilization of the 3-chlorobenzoate substrate.

Construction of shuttle vectors capable of conjugative transfer from Escherichia coli to nitrogen-fixing filamentous cyanobacteria

Abstract: Wild-type cyanobacteria of the genus Anabaena are capable of oxygenic photosynthesis, differentiation of cells called heterocysts at semiregular intervals along the cyanobacterial filaments, and aerobic nitrogen fixation by the heterocysts. To foster analysis of the physiological processes characteristic of these cyanobacteria, we have constructed a family of shuttle vectors capable of replication and selection in Escherichia coli and, in unaltered form, in several strains of Anabaena. Highly efficient conjugative transfer of these vectors from E. coli to Anabaena is dependent upon the presence of broad host-range plasmid RP-4 and of helper plasmids. The shuttle vectors contain portions of plasmid pBR322 required for replication and mobilization, with sites for Anabaena restriction enzymes deleted; cyanobacterial replicon pDU1, which lacks such sites; and determinants for resistance to chloramphenicol, streptomycin, neomycin, and erythromycin.

Molecular aspects of aluminum toxicity

Abstract: The focus in this review is directed to molecular aspects of aluminum toxicity in animal and plant cells. Unique thermodynamic features of Al(lII) ions impart biological specificity which may form the biochemical basis of aluminum interactions with cellular constituents. Current knowledge about aluminum‐specific, molecular interactions is rather scanty. Al(III) ions may coordinate with nucleotides or complex to phospholipids resulting in impaired genetic expression or aluminum‐induced membrane phase changes, respectively. Aluminum‐specific structures are formed with proteins involved in iron transport. and with calmodulin, a key regulatory protein involved in coordinating the actions of second messengers. A novel hypothesis is put forward that Al‐calmodulin may be a primary lesion that occurs in the broadly defined syndrome of aluminum toxicity. Pertinent research areas are discussed.

The metric entropy of diffeomorphisms

Abstract: Soit M une variete de Riemann compacte C ∞ sans bord, soit f un diffeomorphisme C 2 de M, et soit m une mesure de probabilite de Borel f-invariante sur M. Soit h m (f) l'entropie de f. On donne des relations entre h m (f) et les proprietes geometriques de f et de m

Anaerobic processes in soil

Abstract: Anaerobic conditions in soil affect plant productivity as well as organic matter and nutrient dynamics. Anaerobic processes often dominate biological and chemical features of flooded and poorly drained soils but in well-drained soils, anoxia is restricted to small zones and to limited periods. The anaerobic processes listed according to their approximate sequence of occurrence as the redox decreases are: Fe3+ and Mn4+ reduction, denitrification, fermentation, nitrate respiration, dissimilatory nitrate reduction to ammonium, sulfate reduction, carbon dioxide reduction, acetate splitting, and proton reduction. Two of the anaerobic processes, denitrification and fermentation of pollutant chemicals have been studied and recent results are summarized here. We describe the measurement of denitrification using a recirculating atmosphere of acetylene, provide quantitative information on the effect of moisture and oxygen on denitrification, and report on the oxygen concentration within soil aggregates measured by oxygen microelectrodes. The current hypotheses for the pathway leading from nitrate to the N−N bond and N2O are also presented. Recent work in our laboratory has shown a new reaction for the metabolism of some chlorinated organic chemicals. In this reductive dehalogenation, the ring Cl is replaced by a proton. An unusual organism which carried out this reaction has been enriched and isolated on 3-chlorobenzoate. These anaerobic reactions may be of further use in pollutant removal. With these new techniques and knowledge available, it is now possible to gain a better understanding of the biochemistry, physiology, ecology and diversity of the anaerobic organisms and their processes in soil.

Competition between sulfate-reducing and methanogenic bacteria for H2 under resting and growing conditions

Abstract: The basis for the outcome of competition between sulfidogens and methanogens for H2 was examined by comparing the kinetic parameters of representatives of each group separately and in co-culture. Michaelis-Menten parameters (Vmax and Km) for four methanogens and five sulfate-reducing bacteria were determined from H2-depletion data. Further, Monod growth parameters (μmax, Ks, YH2) for Desulfovibrio sp. G11 and Methanospirillum hungatei JF-1 were similarly estimated. H2Km values for the methanogenic bacteria ranged from 2.5 μM (Methanospirillum PM1) to 13 μM for Methanosarcina barkeri MS; Methanospirillum hungatei JF-1 and Methanobacterium PM2 had intermediate H2Km estimates of 5 μM. Average H2Km estimates for the five sulfidogens was 1.2 μM. No consistent difference among the Vmax estimates for the above sulfidogens (mean=100 nmol H2 min-1 mg-1 protein) and methanogens (mean=110 nmol H2 min-1 mg-1 protein) was found. A two-term Michaelis-Menten equation accurately predicted the apparent H2Km values and the fate of H2 by resting co-cultures of sulfate-reducers and methanogens. Half-saturation coefficients (Ks) for H2-limited growth of Desulfovibrio sp. G11 (2–4 μM) and Methanospirillum JF-1 (6–7 μM) were comparable to H2Km estimates obtained for these organisms. Maximum specific growth rates for Desulfovibrio sp. G11 (0.05 h-1) were similar to those of Methanospirillum JF-1 (0.05–0.06 h-1); whereas G11 had an average yield coefficient 4 x that of JF-1. Calculated μmax and Vmax/Km values for the methanogens and sulfidogens studied predict that the latter bacterial group will process more H2 whether these organisms are in a growing or resting state, when the H2 concentration is in the first-order region.

Anaerobic biodegradation of chlorophenols in fresh and acclimated sludge

Abstract: We investigated the anaerobic biodegradation of mono- and dichlorophenol isomers by fresh (unacclimated) sludge and by sludge acclimated to either 2-chlorophenol, 3-chlorophenol, or 4-chlorophenol Biodegradation was evaluated by monitoring substrate disappearance and, in selected cases, production of 14CH4 from labeled substrates In unacclimated sludge, each of the monochlorophenol isomers was degraded The relative rates of disappearance were in this order: ortho greater than meta greater than para For the dichlorophenols in unacclimated sludge, reductive dechlorination of the Cl group ortho to phenolic OH was observed, and the monochlorophenol compounds released were subsequently degraded 3,4-Dichlorophenol and 3,5-dichlorophenol were persistent Sludge acclimated to 2-chlorophenol cross-acclimated to 4-chlorophenol but did not utilize 3-chlorophenol This sludge also degraded 2,4-dichlorophenol Sludge acclimated to 3-chlorophenol cross-acclimated to 4-chlorophenol but not to 2-chlorophenol This sludge degraded 3,4- and 3,5-dichlorophenol but not 2,3- or 2,5-dichlorophenol The specific cross-acclimation patterns observed for monochlorophenol degradation demonstrated the existence of two unique microbial activities that were in turn different from fresh sludge The sludge acclimated to 4-chlorophenol could degrade all three monochlorophenol isomers and 2,4- and 3,4-dichlorophenol The active microbial population in this sludge appeared to be a mixture of populations present in the 2-chlorphenol- and 3-chlorophenol-acclimated sludges, both of which could utilize 4-chlorophenol Experiments with 14C-radiolabeled p-chlorophenol, o-chlorophenol, and 2,4-dichlorophenol demonstrated that these compounds were converted to 14CH4 and 14CO2

Fear-Arousing Persuasive Messages

Abstract: (1984). Fear-Arousing Persuasive Messages. Annals of the International Communication Association: Vol. 8, Communication Yearbook 8, pp. 330-375.

The economics of overeducation

Abstract: This paper provides a brief account of the economics of overeducation. The main emphasis is on explaining Overeducation using several labor-market models and establishing theoretically the impact of overeducation on production. The paper first points out that although overeducation is only a short-run phenomenon according to the neoclassical account of the labor market, it can be a persistent problem when analyzed from the perspective of Spence's job-screening model or Thurow's job-competition model. It then proceeds to argue how overeducation can adversely affect individual productivity. The argument is based on indirect evidence from the industrial-psychology literature which shows that workers with more education than their jobs require often exhibit counterproductive behavior in the workplace. To establish the overeducation-productivity relationship more formally and directly, a production-function model which incorporates the negative impact of overeducation on production has been constructed. This model is based on a review of the economic literature on production and it characterizes production as a two-phase process. The paper concludes with a brief discussion of the implications of overeducation for both private and public policies.

Sequential-request persuasive strategies: Meta-analysis of foot-in-the-door and door-in-the-face.

Abstract: Meta-analysis of the foot-in-the-door (FITD) and door-in-the-face (DITF) literatures showed both effects to be small (r = .17, .15 respectively), even under optimal conditions. Both require aprosocial topic in order to work. The amount of time between the first and second requests plays a different role in the operation of each of the two strategies. DITF was effective only when the delay between requests was brief. Effectiveness of FITD was unrelated to delay, but did depend on whether or not an incentive was provided with the first request. The positive relationship between effort and FITD predicted by self-perception theory was not found. Self-perception theory and reciprocal concessions theory, the theoretical perspectives usually applied to FITD and DITF respectively are examined in light of the findings and it is concluded that both are flawed seriously. Directions for future research are suggested.

A Two-Stage Cross Correlation Approach to Template Matching

Abstract: Two-stage template matching with sum of absolute differences as the similarity measure has been developed by Vanderburg and Rosenfeld [1], [2]. This correspondence shows the development of two-stage template matching with cross correlation as the similarity measure. The threshold value of the first-stage is derived analytically and its validity is verified experimentally. Considerable speed-up over the one-stage process can be obtained by introducing only a small false dismissal probability.

On the Theory of Party Organization

Abstract: Assessments of the condition of our political parties reveal as much about the disarray in our theory of parties as they do about the actual disarray in the parties themselves. This paper argues that in the literature there exists a cumulative theory that explains most of what we know about parties. At the level of party competition this has been laid down by Downs and his successors. The rational-choice model, however, says little about party organization. A theory of party organization can be developed from similar assumptions, thus providing a realistic yet compatible theory of parties. The character of the political party emerges from the fact that it combines three facets of organization in a unique manner: (1) the party maintains itself through market-exchange, making it similar to the business firm and thus unlike the interest group or public bureau; (2) the party's output consists of collective goods, making it similar to the interest group and public bureau yet unlike the business; and (3) the pa...

The structure of medical knowledge in the memories of medical students and general practitioners: categories and prototypes.

Abstract: According to recent research on categorization, knowledge of a given category is structured in memory around key cases or clear examples, referred to as the prototypes, which capture the core meaning of the category. The purpose of this study was to establish a converging sequence of evidence concerning the internal structure of fourteen broad categories of medical disorders as stored in the long-term memories of pre-clinical medical students and experienced doctors. It was shown that the mental representation of the categories was better described by the overlapping features of the prototype view of categorization than the criterial features of the classical view. It is argued that the prototype view may help facilitate the understanding of the learning and problem-solving process in medicine.

Cognitive arithmetic: comparison of operations.

Abstract: Adults' performance of simple arithmetic calculations (addition, multiplication, and numerical comparison) was examined to test predictions of digital (counting), analog, and network models. Although all of these models have been supported by studies of mental addition, each leads to a different prediction concerning relations between the times required for addition, multiplication, and numerical comparison. Pairs of single-digit integers were presented and reaction times (RTs) for adding, multiplying, and comparing the stimuli were collected. A high correlation between RT for addition and multiplication of the same digits was obtained. This result is consistent with a network model, but presents difficulties for both analog and counting models. A "ties" effect of no increase in RT with increases in problem size for doubles such as 2 + 2 has been found in previous studies of addition using verification procedures, but was not found with the production task employed in the present study. Instead, a different kind of ties effect was found. Reaction time for both addition and multiplication of ties increased more slowly with problem size than did RT for non-tie problems. This ties effect, and the finding that probability of making errors contributes independently of problem size to RT support a distinction between location and accessibility of information in a network. Language: en

Role of gibberellin in the growth response of submerged deep water rice.

Abstract: We have shown previously that ethylene, which accumulates in the air spaces of submerged stem sections of rice (Oryza sativa L. cv "Habiganj Aman II"), is involved in regulating the growth response caused by submergence. The role of gibberellins in the submergence response was studied using tetcyclacis (TCY), a new plant growth retardant, which inhibits gibberellin biosynthesis. Stem sections excised from plants that had been watered with a solution of 1 micromolar TCY for 7 to 10 days did not elongate when submerged in the same solution or when exposed to 1 microliter per liter ethylene in air. Gibberellic acid (GA(3)) at 0.3 micromolar overcame the effect of TCY and restored the rapid internodal elongation in submerged and ethylene-treated sections to the levels observed in control sections that had not been treated with TCY. The effect of 0.01 to 0.2 micromolar GA(3) on internodal elongation was enhanced two- to eight-fold when 1 microliter per liter ethylene was added to the air passing through the chamber in which the sections were incubated. GA(3) and ethylene caused a similar increase in cell division and cell elongation in rice internodes. Thus, ethylene may cause internodal elongation in rice by increasing the activity of endogenous GAs. In internodes from which the leaf sheath had been peeled off, growth in response to submergence, ethylene and GA(3) was severely inhibited by light.