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Showing papers by "San Diego State University published in 1990"


Journal ArticleDOI
TL;DR: It is shown that the remaining residual generalization error can be reduced by invoking ensembles of similar networks, which helps improve the performance and training of neural networks for classification.
Abstract: Several means for improving the performance and training of neural networks for classification are proposed Crossvalidation is used as a tool for optimizing network parameters and architecture It is shown that the remaining residual generalization error can be reduced by invoking ensembles of similar networks >

3,891 citations


Book
02 Nov 1990
TL;DR: The article proposes an integration of climate and culture thinking and research and concludes with practical implications for the management of effective contemporary organizations.
Abstract: Organizational climate and organizational culture theory and research are reviewed. The article is first framed with definitions of the constructs, and preliminary thoughts on their interrelationships are noted. Organizational climate is briefly defined as the meanings people attach to interrelated bundles of experiences they have at work. Organizational culture is briefly defined as the basic assumptions about the world and the values that guide life in organizations. A brief history of climate research is presented, followed by the major accomplishments in research on the topic with regard to levels issues, the foci of climate research, and studies of climate strength. A brief overview of the more recent study of organizational culture is then introduced, followed by samples of important thinking and research on the roles of leadership and national culture in understanding organizational culture and performance and culture as a moderator variable in research in organizational behavior. The final section of the article proposes an integration of climate and culture thinking and research and concludes with practical implications for the management of effective contemporary organizations. Throughout, recommendations are made for additional thinking and research.

2,406 citations


Journal ArticleDOI
02 Mar 1990-Science
TL;DR: Studies of ecosystem processes on the Jornada Experimental Range in southern New Mexico suggest that longterm grazing of semiarid grasslands leads to an increase in the spatial and temporal heterogeneity of water, nitrogen, and other soil resources, which leads to the desertification of formerly productive land.
Abstract: Studies of ecosystem processes on the Jornada Experimental Range in southern New Mexico suggest that longterm grazing of semiarid grasslands leads to an increase in the spatial and temporal heterogeneity of water, nitrogen, and other soil resources. Heterogeneity of soil resources promotes invasion by desert shrubs, which leads to a further localization of soil resources under shrub canopies. In the barren area between shrubs, soil fertility is lost by erosion and gaseous emissions. This positive feedback leads to the desertification of formerly productive land in southern New Mexico and in other regions, such as the Sahel. Future desertification is likely to be exacerbated by global climate warming and to cause significant changes in global biogeochemical cycles.

2,376 citations


Journal ArticleDOI
TL;DR: Results indicate that regardless of the particular disorder under investigation, a heightened degree of self-focused attention is found, and it is suggested that certain deviations in this process constitute a psychopathological kind of attention.
Abstract: Working largely independently, numerous investigators have explored the role of self-focused attention in various clinical disorders. This article reviews research examining increased self-focused attention in these disorders. Results indicate that regardless of the particular disorder under investigation, a heightened degree of self-focused attention is found. Hence, as ordinarily conceptualized, self-focused attention has little discriminatory power among different psychological disorders. Using information processing constructs, a somewhat different model of self-focused attention is proposed, and it is suggested that certain deviations in this process constitute a psychopathological kind of attention. A meta-construct model of descriptive psychopathology is then outlined to examine how certain aspects of attention can be considered specific to certain disorders and others common to different disorders.

989 citations


Journal Article
TL;DR: Subjects who reported engaging in three or more exercise sessions per week reported a statistically greater density of pay facilities near their homes than did those who reported no exercise sessions, after controlling for age, education, and income.
Abstract: Although personal determinants of exercise behavior have been studied extensively, few investigators have examined the influence of the physical environment on exercise habits. A random sample of 2,053 residents of San Diego, CA, were surveyed regarding exercise habits and other variables. A total of 385 exercise facilities in San Diego were classified into categories of either free or pay. After the addresses of respondents and facilities were located on a grid-map and coded, the density of exercise facilities around each respondent's home address was computed. Subjects who reported engaging in three or more exercise sessions per week reported a statistically greater density of pay facilities near their homes than did those who reported no exercise sessions, after controlling for age, education, and income. The finding suggests an association between proximity of exercise facilities and frequency of exercise.

424 citations


Journal ArticleDOI
TL;DR: The social transactions of popular, rejected, neglected, and average first- and third-grade boys were examined during their initial encounters with peers, finding that socially interactive behaviors anteceded high preference by peers, and low preference in turn led to social isolation in subsequent sessions.
Abstract: The social transactions of popular, rejected, neglected, and average first- and third-grade boys were examined during their initial encounters with peers. 23 groups of 5 or 6 boys each were observed for 45-min free-play sessions conducted on 5 consecutive days, with sociometric interviews following each session. Social preference in the play groups correlated significantly with classroom social preference after the third and subsequent play sessions for the third graders, and after the fourth and subsequent sessions for the first graders. The observational coding system distinguished 4 types of aggressive behavior that were hypothesized to relate to peer status in different ways. The first, rough play, was not related to peer status. However, rejected boys at both ages displayed significantly higher rates of angry reactive aggression and instrumental aggression than average boys. The relation between bullying and peer status varied with the age of the child. Popular first graders engaged in more bullying than average first graders, but popular third graders did not differ from average in bullying. Other questions concerned the temporal relation between play group behaviors and social preference scores within the group. Socially interactive behaviors anteceded high preference by peers, and low preference in turn led to social isolation in subsequent sessions. Language: en

384 citations


Journal ArticleDOI
TL;DR: A comparison was made between the effects reported in humans following moderate levels of alcohol exposure and the neurobehavioral effects detected using animal models, finding a good deal of congruence with respect to qualitative endpoints.

358 citations


Journal ArticleDOI
TL;DR: The experiment found that GDSS groups were less likely to reach consensus, took more time to reach a decision, and had more e-mail communication problems than conventional manual group methods.
Abstract: As organizational environments become more turbulent and as managers spend more time in meetings in an effort to deal with that turbulence, using information technology to support meetings has become more important. This paper reports on an experiment that compared meetings supported by information technology to meetings with conventional manual support only. The experiment differs from most previous group decision support system (GDSS) experiments in that solutions to the task it used could be objectively scored, it introduced assigned leadership as an independent variable, and it is the first GDSS experiment to compare use of a subset of the University of Arizona GroupSystems GDSS tools to manual group methods. In addition to a communication condition (GDSS or manual) and assigned leadership, the experiment also investigated the effects of anonymity on group process and outcomes. The experiment found that GDSS groups were less likely to reach consensus, took more time to reach a decision, and had more e...

328 citations


Journal ArticleDOI
TL;DR: Increased olfactory thresholds in patients with Alzheimer's disease reflect the effects of the disease process and, thus, may aid in the diagnosis and in the understanding of Alzheimer’s disease.

321 citations


Journal ArticleDOI
TL;DR: Differences in the effects of functional expressive support by source on depressive symptoms are examined and spouse, friends, and adult children were found to rank in descending order of importance.
Abstract: Although global measures of social support demonstrate significant effects on psychological and physical well-being, the differential significance of various support sources is largely unknown. The present study examines differences in the effects of functional expressive support by source on depressive symptoms. This approach is contrasted with network interaction studies of elderly persons, which do not measure functional support but do suggest that friends are distinctly significant. Spouse, friends, and adult children were found to rank in descending order of importance; relatives show no effect. Low support may have stronger effects than unavailability of sources. Effects of supports and stressors are not conditioned by age, sex, or widowhood. Implications of findings and further research needs are discussed.

259 citations


Journal ArticleDOI
TL;DR: This paper examined the role of visually explicit sexual stimuli in the processing of verbal information in a persuasive message, and the resulting effect on traditional outcome measures of recall, attitudes, and behavioral intentions, as well as higher-order cognitive response measures.
Abstract: Previous research on the use of either implicit or explicit sexual imagery in advertising has focused mainly on factors such as the gender of the receiver, the product advertised (sexually or non-sexually related), and the type of stimulus presented (double entendre, decorative models, and nudity). Many of the relevant studies have focused on lower-order cognitive processes such as recall and/or recognition. Few, if any at all, examine the higher-order cognitive processes underlying reactions to sexually explicit material. The present study examines the role of visually explicit sexual stimuli in the processing of verbal information in a persuasive message, and the resulting effect on traditional outcome measures of recall, attitudes, and behavioral intentions, as well as higher-order cognitive response measures. In so doing, the study contributes to a greater understanding of sexual- and non-sexual appeals and how they are affected by information level.

Journal ArticleDOI
TL;DR: In this paper, a self-report inventory of sources of life-stress and symptoms of stress is described, which can be used to determine the nature of an athlete's response to training, particularly their capacity to tolerate training loads.
Abstract: A self-report inventory of sources of life-stress and symptoms of stress is described. The tool can be used to determine the nature of an athlete's response to training, particularly his/her capacity to tolerate training loads. Data are used to demonstrate the use of the inventory to determine i) training responses which are either too stressed or under-stressed, ii) the ideal amount of stress to promote the optimum level of training effort, iii) the influence of outside-of-sport stresses that interfere with the training response, iv) preliminary features of overtraining, v) reactions to jet-lag and travel fatigue, and vi) peaking responses.

Journal ArticleDOI
TL;DR: The authors investigated the interaction between affect and language through storytelling and found that the Williams syndrome subjects tell coherent and complex narratives that make extensive use of affective prosody, whereas the Down subjects are infused with lexically encoded narrative evaluative devices that enrich the referential content of the stories.
Abstract: The study of clearly identifiable patterns of atypical development can inform normal development in significant ways. Delayed or deviant development puts in high relief not only the sequence of development but also the individual components. This article presents the results of studies that compare adolescents with Williams syndrome, a rare metabolic neurodevelopmental disorder resulting in mental retardation, with cognitively matched adolescents with Down syndrome. We investigate the interaction between affect and language through storytelling. In contrast to the adolescents with Down syndrome, the Williams syndrome subjects tell coherent and complex narratives that make extensive use of affective prosody. Furthermore, stories from the Williams but not the Down subjects are infused with lexically encoded narrative evaluative devices that enrich the referential content of the stories. This contrast in expressivity between two matched atypical groups provides an unusual perspective on the underlying structure of the social cognitive domain.

Journal ArticleDOI
TL;DR: A general theoretical approach is developed to analyze the morphological and physiological responses of plants to nitrogen availability.

Journal ArticleDOI
TL;DR: The results strongly suggest that transcriptionally active genome regions are preferred targets for retrovirus integration in mouse fibroblasts.
Abstract: We have analyzed the transcriptional activity of cellular target sequences for Moloney murine leukemia virus integration in mouse fibroblasts. At least five of the nine random, unselected integration target sequences studied showed direct evidence for transcriptional activity by hybridization to nuclear run-on transcripts prepared from uninfected cells. At least four of the sequences contained multiple recognition sites for several restriction enzymes that cut preferentially in CpG-rich islands, indicating integration into 5' or 3' ends or flanking regions of genes. Assuming that only a minor fraction (less than 20%) of the genome is transcribed in mammalian cells, we calculated the probability that this association of retroviral integration sites with transcribed sequences is due to chance to be very low (1.6 x 10(-2]. Thus, our results strongly suggest that transcriptionally active genome regions are preferred targets for retrovirus integration.

Journal ArticleDOI
TL;DR: The EMAP (Electromagnetic Array Profiling) method combats the inherent spatial high-pass characteristics of EM distortions by low-pass operations in data collection and processing as discussed by the authors, which proposes the continuous, in-field measurement of electric field dipoles to avoid spatial aliasing.
Abstract: The most revealing description of electromagnetic (EM) distortions due to near-surface inhomogeneities and topography is in terms of galvanic and inductive effects. In either case, the distorted electric and magnetic fields can be best visualized as a vectorial sum of primary and secondary fields. Secondary electric fields due to electric charge build-up in the galvanic case persist to the longest periods. In contrast, the secondary electric and magnetic fields due to inductive, vortex currents disappear at long periods. The static shift of magnetotelluric (MT) apparent resistivity sounding curves is a classic example of the galvanic effect. Methods to correct for unwanted distortions such as the static shift can be classified into six categories: use of invariant response parameters, curve shifting, statistical averaging, spatial filtering, use of distortion tensors, and computer modeling. Although invariant impedance calculations are simple to make, they cannot, in general, recover the undistorted impedance. Short period curve shifting is best done with auxiliary soundings such as time domain EM; however, this requires multiple surveys. The shifting of long period MT sounding branches is useful if a standard curve is known and can be matched. Statistical averaging of neighboring MT soundings that are conformal but static shifted has proven very effective at removing random distortions if adaquate data are available. The new EMAP (Electromagnetic Array Profiling) method combats the inherent spatial high pass characteristics of EM distortions by low pass operations in data collection and processing. EMAP proposes the continuous, in-field measurement of electric field dipoles to avoid spatial aliasing. Distortion tensor stripping of topographic distortions is possible since terrain is deterministic but stripping the effects of uncertain subsurface inhomogeneities may be misleading. A new decomposition of the MT impedance tensor under the assumption of surficial three-dimensional (3-D) galvanic effects imposed on a one- or two-dimensional (1-D and 2-D) regional setting promises a way to recover the regional structure. There is a continual need for 3-D computer modeling to test new methods and to calculate topographic and regional effects. Computer modeling has established the value of 2-D modeling of the data identified as transverse magnetic (TM) in some 3-D environments. Ideally, EM distortion correction requires continuous, or at least many, data and the application of more than one correction-modeling scheme.

Journal ArticleDOI
TL;DR: Reductions in leaf area have the strongest effect on resource capture and use during non-water-stressed periods and the least effect under extreme drought conditions, while shifts in physiological response lead to large savings of water and efficient water use under extreme stress.
Abstract: Mediterranean sclerophyll shrubs respond to seasonal drought by adjusting the amount of leaf area exposed and by reducing gas exchange via stomatal closure mechanisms. The degree to which each of these modifications can influence plant carbon and water balances under typical mediterranean-type climate conditions is examined. Leaf area changes are assessed in the context of a canopy structure and light microclimate model. Shifts in physiological response are examined with a mechanistically-based model of C3 leaf gas exchange that simulates progressive reduction of maximum photosynthesis and transpiration rates and increasingly strong midday stomatal closure over the course of drought. The results demonstrate that midday stomatal closure may effectively contribute to drought avoidance, increase water use efficiency, and strongly alter physiological efficiency in the conversion of intercepted light energy to photoproducts. Physiological adjustments lead to larger reductions in water use than occur when comparing leaf area index 3.5 to 1.5, extremes found for natural stands of sclerophyll shrubs in the California chaparral. Reductions in leaf area have the strongest effect on resource capture and use during non-water-stressed periods and the least effect under extreme drought conditions, while shifts in physiological response lead to large savings of water and efficient water use under extreme stress. An important model parameter termed GFAC (proportionality factor expressing the relation of conductance [g] to net photosynthesis rate) is utilized, which changes in response to the integrated water stress experimence of shrubs and alters the degree to which stomata may open for a given rate of carbon fixation. We attempt to interpret this parameter in terms of physiological mechanisms known to modify control of leaf gas exchange during drought. The analysis helps visualize means by which canopy gas exchange behavior may be coupled to physiological changes occurring in the root environment during soil drying.

Journal ArticleDOI
TL;DR: Analysis of measurements in situ in Eriophorum tussock tundra and seasonality was the best predictor of ecosystem CO2 flux at both ambient and elevated CO2 levels, suggesting little if any long-term stimulation of ecosystem carbon acquisition by increases in atmospheric CO2.
Abstract: Whole ecosystem CO2 flux under ambient (340 μl/l) and elevated (680 μl/l) CO2 was measured in situ in Eriophorum tussock tundra on the North Slope of Alaska. Elevated CO2 resulted in greater carbon acquisition than control treatments and there was a net loss of CO2 under ambient conditions at this upland tundra site. These measurements indicate a current loss of carbon from upland tundra, possibly the result of recent climatic changes. Elevated CO2 for the duration of one growing season appeared to delay the onset of dormancy and resulted in approximately 10 additional days of positive ecosystem flux. Homeostatic adjustment of ecosystem CO2 flux (sum of species' response) was apparent by the third week of exposure to elevated CO2. Ecosystem dark respiration rates were not significantly higher at elevated CO2 levels. Rapid homeostatic adjustment to elevated CO2 may limit carbon uptake in upland tundra. Abiotic factors were evaluated as predictors of ecosystem CO2 flux. For chambers exposed to ambient and elevated CO2 levels for the duration of the growing season, seasonality (Julian day) was the best predictor of ecosystem CO2 flux at both ambient and elevated CO2 levels. Light (PAR), soil temperature, and air temperature were also predictive of seasonal ecosystem flux, but only at elevated CO2 levels. At any combination of physical conditions, flux of the elevated CO2 treatment was greater than that at ambient. In short-term manipulations of CO2, tundra exposed to elevated CO2 had threefold greater carbon gain, and had one half the ecosystem level, light compensation point when compared to ambient CO2 treatments. Elevated CO2-acclimated tundra had twofold greater carbon gain compared to ambient treatments, but there was no difference in ecosystem level, light compensation point between elevated and ambient CO2 treatments. The predicted future increases in cloudiness could substantially decrease the effect of elevated atmospheric CO2 on net ecosystem carbon budget. These analyses suggest little if any long-term stimulation of ecosystem carbon acquisition by increases in atmospheric CO2.

Journal ArticleDOI
TL;DR: Concept mapping and semantic networking are complementary strategies that can be used effectively in tandem to help students learn, to help teachers teach, and to support cognitive research.
Abstract: This article briefly describes the SemNet™ software and some of its uses as an educational and research tool, with emphasis on the similarities and differences between concept mapping and semantic networking. A semantic network captures (in part) each concept's position in psychological space, identifying both the other concepts to which it is connected and the nature of the links that bind them. Computer-based semantic networks differ from paper-and-pencil maps in that they are n-dimensional; each concept can be linked to many other concepts; relations are bidirectional; representations can include images, text, and sound; and nets can be very large. Disadvantages of SemNet™ networks include (a) the difficulties in obtaining a clear overview and (b) the homogeneous nature of the representations, in which all links look alike. Advantages include the ability to integrate ideas across a large knowledge base, the ease and rapidity of net creation, the ease with which elements (concepts, relations, or propositions) can be found within nets, and the utility of nets as self-study tools. Concept mapping and semantic networking are complementary strategies that can be used effectively in tandem to help students learn, to help teachers teach, and to support cognitive research.

Journal ArticleDOI
TL;DR: Evidence is provided for the independent BP lowering effect of aerobic exercise in unmedicated mildly hypertensive men and a crossover replication of the aerobic regimen in the placebo exercise group is conducted.
Abstract: To determine the antihypertensive efficacy of aerobic exercise training in mild essential hypertension, a prospective randomized controlled trial was conducted comparing an aerobic exercise regimen to a placebo exercise regimen, with a crossover replication of the aerobic regimen in the placebo exercise group. The study took place in an outpatient research clinic in a university-affiliated Veterans Administration medical center. Twenty-seven men with untreated diastolic blood pressure (DBP) of 90-104 mm Hg were randomized to the two exercise regimens. Ten patients completed the aerobic regimen. Nine patients completed the control regimen, seven of whom subsequently entered and completed the aerobic regimen. The aerobic regimen consisted of walking, jogging, stationary bicycling, or any combination of these activities for 30 minutes, four times a week, at 65-80% maximal heart rate. The control regimen consisted of slow calisthenics and stretching for the same duration and frequency but maintaining less than 60% maximal heart rate. DBP decreased 9.6 +/- 4.7 mm Hg in the aerobic exercise group but increased 0.8 +/- 6.2 mm Hg in the placebo control exercise group (p = 0.02). Systolic blood pressure (SBP) decreased 6.4 +/- 9.1 mm Hg in the aerobic group and increased 0.9 +/- 9.7 mm Hg in the control group (p = 0.11). Subsequently, seven of the nine controls entered a treatment crossover and completed the aerobic regimen with significant reductions in both DBP (-6.1 +/- 3.2 mm Hg, p less than 0.01) and SBP (-8.1 +/- 5.7 mm Hg, p less than 0.01). BP changes were not associated with any significant changes in weight, body fat, urinary electrolytes, or resting heart rate. This randomized controlled trial provides evidence for the independent BP lowering effect of aerobic exercise in unmedicated mildly hypertensive men.

Journal ArticleDOI
TL;DR: In this article, a model of pedogenesis is framed in an evolutional paradigm that emphasizes the integrated effects of dynamic and passive pedogenic vectors in directing pathways and in controlling rates of soil genesis through time.

Journal ArticleDOI
TL;DR: It is concluded that prenatal alcohol exposure does have long lasting effects, although some of these might only occur under challenging or stressful circumstances, and may only be detected when these compensatory systems break down.
Abstract: Prenatal exposure to alcohol can cause a variety of behavioral disturbances later in life. Many of the reports in animals of the behavioral teratogenic effects of alcohol have focused on assessing younger animals. The purpose of this paper is to review some of the longer lasting behavioral consequences of gestational alcohol exposure in animals. It is not meant as a comprehensive review, but rather focuses on selected studies. It is concluded that prenatal alcohol exposure does have long lasting effects, although some of these might only occur under challenging or stressful circumstances. It is hypothesized that as the animal matures compensatory mechanisms or strategies develop to compensate for these dysfunctions. Thus, behavioral problems may only be detected when these compensatory systems break down, either as a result of stress, because of complex testing procedures, or old age.

Journal ArticleDOI
TL;DR: In this article, the Weinhold-Ruppeiner metric is derived from the microscopic entropy of the thermodynamic phase space, and a non-degenerate bilinear form on the phase space is constructed, whose restriction to Gibbs space can serve as an alternative to the metric proposed by Gilmore.
Abstract: We show how both the contact structure and the metric structure of the thermodynamic phase space arise in a natural way from a generalized canonical probability distribution \ensuremath{\rho} In particular, the metric form and the contact form are found to be derived from the microscopic entropy s=-ln\ensuremath{\rho} Thus the first law and the second law of thermodynamics can be given the geometric interpretation that a thermodynamic system must possess both a contact and a compatible metric structure We proceed to construct explicitly a new nondegenerate bilinear form on the thermodynamic phase space, whose restriction to state space yields the Weinhold-Ruppeiner metric, and whose restriction to Gibbs space can serve as an alternative to the metric proposed by Gilmore

Journal ArticleDOI
TL;DR: A newly discovered fossil locality at Lano (Basque Country) has yielded a vertebrate assemblage of probably Maastrichtian age comprising fishes, amphibians, reptiles and mammals.
Abstract: A newly discovered fossil locality at Lano (Basque Country) has yielded a vertebrate assemblage of probably Maastrichtian age comprising fishes, amphibians, reptiles and mammals. It considerably enlarges our knowledge of the Late Cretaceous continental faunas of Europe, hitherto based on a much less complete record. Some taxa are recorded for the first time in Europe, and the fauna also contains the oldest known representatives of some groups (amphisbaenians, salamandrids). The Lan assemblage reveals an original fauna comprising both forms related to Asian and North American groups and elements with Gondwanan affinities.

Journal ArticleDOI
TL;DR: In this article, the value of the optimal taper depends on the C/sub x/C/sub y/ ratio: the best taper exceeds Jaeger's 2.72 slope, but only moderately.
Abstract: Jaeger's buffer comprises a string of tapered inverters. Each inverter is molded by a capacitor and a conductor. In this work, the capacitor is split into inherent and load components (C/sub x/ and C/sub y/), and it is shown that the value of the optimal taper depends on the C/sub x//C/sub y/ ratio: the best taper exceeds Jaeger's 2.72 slope, but only moderately. >

Journal ArticleDOI
TL;DR: Two promoters for the Escherichia coli operon that contains the four genes dnaA, dnaN, recF, and gyrB were found to be growth rate regulated and under stringent control and it is proposed that one mechanism for coupling DNA replication to the growth rate of bacteria is through ppGpp synthesis at the ribosome.
Abstract: Two promoters for the Escherichia coli operon that contains the four genes dnaA, dnaN, recF, and gyrB were found to be growth rate regulated and under stringent control. Transcript abundance relative to total RNA increased with the growth rate. Changes in transcription from the dnaAp1 and dnaAp2 promoters that were induced by amino acid starvation and chloramphenicol and were relA dependent were correlated with the stringent response. The abundance of these transcripts per total RNA also decreased in spoT mutants as the severity of the mutation increased (guanosine 5'-diphosphate 3'-diphosphate [ppGpp] basal levels increased). Because expression of these promoters appears to be inhibited by ppGpp, it is proposed that one mechanism for coupling DNA replication to the growth rate of bacteria is through ppGpp synthesis at the ribosome.

Journal ArticleDOI
TL;DR: The absence of other alternative exons in the rod-coding region, aside from those shown previously to encode alternative carboxyl termini, demonstrates that the bulk of the myosin rod is not involved in the generation of isoform-specific properties of the MHC molecule.
Abstract: By comparing the structure of wild-type and mutant muscle myosin heavy chain (MHC) genes of Drosophila melanogaster, we have identified the defect in the homozygous-viable, flightless mutant Mhc10. The mutation is within the 3' splice acceptor of an alternative exon (exon 15a) that encodes the central region of the MHC hinge. The splice acceptor defect prevents the accumulation of mRNAs containing exon 15a, whereas transcripts with a divergent copy of this exon (exon 15b) are unaffected by the mutation. In situ hybridization and Northern blot analysis of wild-type organisms reveals that exon 15b is used in larval MHCs, whereas exons 15a and/or 15b are used in adult tissues. Because Mhc10 mutants fail to accumulate transcripts encoding MHC protein with hinge region a, analysis of their muscle-specific reduction in thick filament number serves as a sensitive assay system for determining the pattern of accumulation of MHCs with alternative hinge regions. Electron microscopic comparisons of various muscles from wild-type and Mhc10 adults reveals that those that contract rapidly or develop high levels of tension utilize only hinge region a, those that contract at moderate rates accumulate MHCs of both types, and those that are slowly contracting have MHCs with hinge region b. The presence of alternative hinge-coding exons and their highly tissue-specific usage suggests that this portion of the MHC molecule is important to the isoform-specific properties of MHC that lead to the different physiological and ultrastructural characteristics of various Drosophila muscle types. The absence of other alternative exons in the rod-coding region, aside from those shown previously to encode alternative carboxyl termini, demonstrates that the bulk of the myosin rod is not involved in the generation of isoform-specific properties of the MHC molecule.

Journal ArticleDOI
TL;DR: It was concluded that naive individuals can be taught to reliably conduct and score the Seven-Day Physical Activity Recall interview in a brief training program.
Abstract: The Seven-Day Physical Activity Recall interview is commonly used in epidemiologic research, but the methods of training and certifying interviewers have not been studied or standardized. The purpose of this study was to examine the reliability of the Seven-Day Physical Activity Recall interviews after a structured training program. Twenty-one volunteer interviewers participated in a five-session group training program that targeted standardized interview techniques and scoring procedures. Interviewers scored eight videotaped interviews on two occasions to assess scoring skills. Across all videotapes and interviewers, the test-retest reliability was .99. Two interviewers independently interviewed the same person on the same day, and the reliability of kilocalorie expenditure across interviewers was .86. It was concluded that naive individuals can be taught to reliably conduct and score the Seven-Day Physical Activity Recall interview in a brief training program.

Journal ArticleDOI
TL;DR: This study compares two different ems software tools in a controlled experiment and found that one software tool produced better quality solutions to a combination creativity and intellective task, but the other helped generate more unique alternatives.
Abstract: :Various aspects of the design and use of Electronic Meeting Systems (ems) have been investigated in laboratory and field studies, but until now no one has systematically investigated the role of ems software on group performance. The current study compares two different ems software tools in a controlled experiment. Dependent variables are decision quality, number of unique alternatives generated, satisfaction, and consensus. The study found that one software tool produced better quality solutions to a combination creativity and intellective task, but the other helped generate more unique alternatives. Each tool worked best on the task for which it was designed. The findings support the authors’ premise that there should be a match between the ems software tool and the task to be performed. The findings have several implications for the design of ems software.

Journal ArticleDOI
01 Oct 1990-Language
TL;DR: In this paper, semantic and cognitive development were studied in eight Korean and French-speaking children, and these results were compared with results for 12 English-speakers, which suggests that children may have been motivated to acquire these words because of their cognitive significance.
Abstract: Semantic and cognitive development were studied in eight Korean and French-speaking children, and these results were compared with results for 12 English-speakers. The children received object- permanence, means-ends and categorization tasks and their develop ment of related linguistic forms, disappearance and success/failure words and a naming spurt, was recorded. There were close and specific relations between these semantic and cognitive developments. However, non-English-speakers used very different forms from English-speakers to encode disappearance, success and failure; in particular, Korean-speakers used verbs. This suggests that children may have been motivated to acquire these words because of their cognitive significance. Moreover, both categorization and naming developed later in the Korean-speakers than in English-speakers and French-speakers. This may be due to the fact that verbs are more perceptually salient in Korean than nouns. This difference between the language groups also suggests tha...