Showing papers by "Texas Christian University published in 1998"
TL;DR: The results indicate that mev-1 governs the rate of ageing by modulating the cellular response to oxidative stress, which may cause an indirect increase in superoxide levels, which in turn leads to oxygen hypersensitivity and premature ageing.
Abstract: Much attention has focused on the aetiology of oxidative damagein cellular and organismal ageing1,2,3,4. Especially toxic arethe reactive oxygen byproducts of respiration and other biological processes5. A mev-1 (kn1 ) mutant of Caenorhabditis elegans has been found to be hypersensitive to raised oxygen concentrations6,7. Unlike the wild type, its lifespan decreases dramatically as oxygen concentrations are increased from 1 to 60% (ref. 7). Strains bearing this mutation accumulate markers of ageing (such as fluorescent materials and protein carbonyls) faster than the wild type8,9. We show here that mev-1 encodes a subunit of the enzyme succinate dehydrogenase cytochrome b , which is a component of complex II of the mitochondrial electron transport chain. We found that the ability of complex II to catalyse electron transport from succinate to ubiquinone is compromised in mev-1 animals. This may cause an indirect increase in superoxide levels, which in turn leads to oxygen hypersensitivity and premature ageing. Our results indicate that mev-1 governs the rate of ageing by modulating the cellular response to oxidative stress.
676 citations
TL;DR: In this article, the authors examined client motivation as a predictor of retention and therapeutic engagement across the major types of treatment settings represented in the third national drug abuse treatment outcome study (DATOS) conducted in the United States.
Abstract: Aims. This study examined client motivation as a predictor of retention and therapeutic engagement across the major types of treatment settings represented in the third national drug abuse treatment outcome study (DATOS) conducted in the United States. Design. Sequential admissions during 1991-93 to 37 programs provided representative samples of community-based treatment populations. Based on this naturalistic non-experimental evaluation design, hierarchical linear model (HLM) analysis for nested data was used to control for systematic variations in retention rates and client attributes among programs within modalities. Setting. The data were collected from long-term residential (LTR), outpatient methadone (OMT) and outpatient drug-free (ODF) programs located in 11 large cities. Participants. A total of 2265 clients in 18 LTR, 981 clients in 13 OMT and 1791 clients in 16 ODF programs were studied. Measurements. Pre-treatment variables included problem recognition and treatment readiness (two stages of motivation), socio-demographic indicators, drug use history and dependence, criminality, co-morbid psychiatric diagnosis and previous treatment. Retention and engagement (based on ratings of client and counselor relationships) served as outcome criteria. Findings. Pre-treatment motivation was related to retention in all three modalities, and the treatment readiness scale was the strongest predictor in LTR and OMT. Higher treatment readiness also was significantly related to early therapeutic engagement in each modality. Conclusions. Indicators of intrinsic motivation-especially readiness for treatment-were not only significant predictors of engagement and retention, but were more important than socio-demographic, drug use and other background variables. Improved assessments and planning of interventions that focus on stages of readiness for change and recovery should help improve treatment systems.
381 citations
TL;DR: The authors performed a comparative analysis of the impact of industry structural characteristics on the formation of large and small businesses in a large sample of U.S. manufacturing industries from 1977 to 1987.
Abstract: Despite growing recognition of some strategic advantages held by small firms, little comparative research has been performed on the advantages and disadvantages accruing to firm size. In order to delineate the differential responses of small and large businesses to their environmental context, we perform a comparative analysis of the impact of industry structural characteristics on the formation of large and small businesses in a large sample of U.S. manufacturing industries from 1977 to 1987. The results suggest that small businesses possess certain resources that allow them to overcome some barriers which create greater difficulties for their larger counterparts, as well as allow small businesses to exploit certain industry opportunities more readily than larger ones. © 1998 John Wiley & Sons, Ltd.
379 citations
TL;DR: In this paper, the authors evaluate corporate voluntary disclosure of forward-looking information under the safe harbor provision of the Private Securities Litigation Reform Act of 1995 and find that there was a significant increase in both the frequency of firms issuing forecasts and the number of forecasts issued following enactment of the Reform Act.
Abstract: This study evaluates corporate voluntary disclosure of forward-looking information under the safe harbor provision of the Private Securities Litigation Reform Act of 1995. Using data on earnings and sales forecasts issued by 547 computer, software, and drug firms, we find that there was a significant increase in both the frequency of firms issuing forecasts and the number of forecasts issued following enactment of the Reform Act. The increased level of disclosure is primarily attributable to managers issuing more long horizon forecasts of good news and short horizon forecasts of bad news. Moreover, there is some evidence that the forecasts issued after the safe harbor took effect specified a more precise estimate of expected future earnings performance. We also find that the increase in disclosure was not at the expense of forecast quality in that forecasts issued after passage of the Reform Act are no less accurate than those issued previously. In particular, there is no evidence to support critics' concern that the protection of the safe harbor would prompt managers to issue more overly optimistic statements to investors.
356 citations
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TL;DR: Using 70,822 observations on housing prices from 1969 to 1991 from Fairfax County Virginia, this article demonstrates the substantial benefits obtained by modeling the spatial as well as the temporal dependence of the data.
Abstract: Using 70,822 observations on housing prices during 1969-91 from Fairfax County Virginia, this manuscript demonstrates the substantial benefits obtained by modeling the spatial as well as the temporal dependence of the data. Specifically, the spatio temporal autoregression with 12 variables reduced median absolute error by 37.35% relative to an indicator-based model with 26 variables. One-step ahead forecasts also document the improved performance of the proposed spatio-temporal model. In addition, the manuscript illustrates techniques for rapidly computing the estimates and shows how to compute indices for any location.
302 citations
TL;DR: In this article, a spatiotemporal autoregression with twelve variables reduced median absolute error by 37.35% relative to an indicator-based model with twenty-six variables.
Abstract: Using 70,822 observations on housing prices from 1969 to 1991 from Fairfax County Virginia, this article demonstrates the substantial benefits obtained by modeling the spatial as well as the temporal dependence of the data. Specifically, the spatiotemporal autoregression with twelve variables reduced median absolute error by 37.35% relative to an indicator-based model with twenty-six variables. One-step ahead forecasts also document the improved performance of the proposed spatiotemporal model. In addition, the article illustrates techniques for rapidly computing the estimates and shows how to compute indices for any location.
267 citations
TL;DR: For example, the authors found that boards of directors in venture-capital backed companies are more involved in both strategy formation and evaluation than are boards where members do not have large ownership stakes, even when industry, board size, level of diversification, and insider board representation are held constant.
262 citations
TL;DR: The dicaffeoylquinic acids and DCTAs are a potentially important class of HIV inhibitors that act at a site distinct from that of current HIV therapeutic agents.
Abstract: Current pharmacological agents for human immunodeficiency virus (HIV) infection include drugs targeted against HIV reverse transcriptase and HIV protease. An understudied therapeutic target is HIV integrase, an essential enzyme that mediates integration of the HIV genome into the host chromosome. The dicaffeoylquinic acids (DCQAs) and the dicaffeoyltartaric acids (DCTAs) have potent activity against HIV integrase in vitro and prevent HIV replication in tissue culture. However, their specificity against HIV integrase in cell culture has been questioned. Thus, the ability of the DCQAs and DCTAs to inhibit binding of HIV type 1 (HIV-1) gp120 to CD4 and their activities against HIV-1 reverse transcriptase and HIV RNase H were studied. The DCQAs and DCTAs inhibited HIV-1 integrase at concentrations between 150 and 840 nM. They inhibited HIV replication at concentrations between 2 and 12 μM. Their activity against reverse transcriptase ranged from 7 μM to greater than 100 μM. Concentrations that inhibited gp120 binding to CD4 exceeded 80 μM. None of the compounds blocked HIV-1 RNase H by 50% at concentrations exceeding 80 μM. Furthermore, when the effects of the DCTAs on reverse transcription in acutely infected cells were measured, they were found to have no activity. Therefore, the DCQAs and DCTAs exhibit >10- to >100-fold specificity for HIV integrase, and their activity against integrase in biochemical assays is consistent with their observed anti-HIV activity in tissue culture. Thus, the DCQAs and DCTAs are a potentially important class of HIV inhibitors that act at a site distinct from that of current HIV therapeutic agents.
199 citations
TL;DR: The criminal justice system (CJS) can influence treatment participation and retention, and it appears essential for the CJS and treatment programs to maintain an open and constructive relationship to maximize their potential combined impact.
Abstract: This study examined the association between legal pressure and treatment retention in a national sample of 2,605 clients admitted to 18 long-term residential facilities that participated in the Drug Abuse Treatment Outcome Study (DATOS). Hierarchical linear models were used to assess the relationship of background factors and legal pressure with treatment participation for 90 days or longer. Two thirds of the sample entered residential treatment with moderate to high pressure from legal authorities, and they were significantly more likely than the low-pressure clients to stay 90 days or more. Moreover, the difference in retention between moderate-to-high-and low-pressure clients was even greater in programs with proportionally larger caseloads under legal surveillance. The criminal justice system (CJS) can influence treatment participation and retention, and it appears essential for the CJS and treatment programs to maintain an open and constructive relationship to maximize their potential combined impact.
135 citations
TL;DR: This article reported a U-Pb zircon age of 1105 ± 2 Ma for the extensive Umkondo dolerites in eastern Zimbabwe, which are part of a large igneous province that can be traced over much of southern Africa and originally contiguous parts of East Antarctica.
Abstract: We report a U-Pb zircon age of 1105 ± 2 Ma for the extensive Umkondo dolerites in eastern Zimbabwe, which are part of a large igneous province that can be traced over much of southern Africa and originally contiguous parts of East Antarctica. Other members of the province include widespread tholeiitic intrusions in Botswana and South Africa, bimodal volcanic rocks in Botswana and Namibia, and dolerites and flood basalts in Dronning Maud Land, Antarctica. Available data indicate that substantial parts of the province were emplaced in a restricted interval at ca. 1.1 Ga and originated from a large-scale mantle thermal anomaly inboard of a coeval continental-margin orogen. Striking similarities in age and tectonic setting between the Umkondo igneous province and widespread 1.1 Ga within-plate magmatism in Laurentia are consistent with reconstructions of the early Neoproterozoic Rodinia supercontinent that place southern Africa and Dronning Maud Land off the southern tip of Laurentia.
109 citations
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TL;DR: In this paper, the authors examined the effect of two alternative approaches to segment definition: segments defined by grouping similar products (similarity approach) and segment defined by a company?s internal reporting classification (management approach).
Abstract: This paper reports results from an experiment which provide evidence on how certain provisions of current and revised segment reporting standards affect financial analysts? judgments. Specifically, we examine the effect of two alternative approaches to segment definition: segments defined by grouping similar products (similarity approach) and segments defined by a company?s internal reporting classification (management approach). The first approach is used currently under SFAS No. 14 as the basis for determining externally-reported segments, while the second approach will be used after December 15, 1997, the effective date of the FASB?s new segment reporting standard, SFAS No. 131, Disclosures about Segments of an Enterprise and Related Information. Results show that analysts perceived segment reporting to be more reliable when similar products were combined in a segment (SFAS No. 14) than when dissimilar products were combined, and when external segments were the same as those used internally (SFAS No. 131) than when external and internal segments differed. Analysts? confidence in their earnings forecasts and stock valuation judgments was affected by the interaction of the similarity and management approaches. As long as external segments were the same as internal segments, analysts? confidence was not affected by whether products combined in a segment were similar or dissimilar. In contrast, if external and internal segments differed, analysts had greater confidence in their judgments when similar products were combined in a segment than when dissimilar products were combined. These results support the FASB?s position that the management approach will positively affect analysts? perceptions of the reliability of segment data. In addition, our results suggest that, in certain cases, the management approach will enhance analysts? confidence in reported segment data.
TL;DR: The data indicate that the exercise and diet manipulation altered the number of circulating leukocytes but did not affect the decrease in lymphocyte proliferation that occurred after exercise.
Abstract: To determine the effect of carbohydrate (CHO) status on immune responses after long-duration exercise, on two occasions, 10 men completed a glycogen-depleting bout of cycle ergometry followed by 48...
01 Jan 1998
TL;DR: Examining the ecological, behavioral, and genetic characteristics of host races and recently evolved sibling species of phytophagous insects can test assumptions about the evolution of reproductive isolation made in different models of speciation.
Abstract: Speciation involves the evolution of reproductive isolation between populations (Mayr 1963; Bush 1994). Despite many controversies about how species are defined, and how they evolve, the study of reproductive isolating mechanisms remains central to understanding speciation. Different speciation models make very different assumptions about how reproductive isolation evolves (Mayr 1963; Bush 1975a, 1994; White 1978). Host races and recently evolved sibling species of phytophagous insects offer unique opportunities to study the speciation process. Because the process of speciation is ongoing or recently completed, these extant populations retain the characteristics that were responsible for the evolution of their reproductive isolation. By examining the ecological, behavioral, and genetic characteristics of these populations, we can test assumptions about the evolution of reproductive isolation made in different models of speciation.
TL;DR: Results support the notion that the medial frontal cortex of the rat is a functionally dissociable region and suggest that the prelimbic area appears to be critical for working memory, but less so for attention processes.
TL;DR: Achieving successful implementation is a continuing challenge to the executives responsible for executing strategies and to the scholars seeking to understand implementation processes as mentioned in this paper. But the importance of implementation is not questioned by executives or scholars, although the activity warrants much more attention than it has been given in the past.
Abstract: Achieving successful implementation is a continuing challenge to the executives responsible for executing strategies and to the scholars seeking to understand implementation processes. The importance of implementation is not questioned by executives or scholars, although the activity warrants much more attention than it has been given in the past. Penetrating analyses of strategy implementation by scholars like Piercy (1998) are important and essential to moving the topic beyond action checklists to conceptual foundations for guiding empirical research and executive action. Advancing the state of knowledge of implementation will be enhanced if scholars and executives work together to advance thought and practice.
TL;DR: Progesterone treatment decreased the amount of neuronal death seen in the striatum and the mediodorsal nucleus of the thalamus, consistent with the notion that progesterone is an effective neuroprotective agent and suggest that the hormone can reduce the behavioral impairments associated with frontal cortical ablation injury.
TL;DR: This paper examined the risk and return characteristics of emerging markets and found that these markets have not produced high levels of compound returns relative to U.S. stock markets for the 20-year time period ending in June 1995.
Abstract: Capital markets in developing countries have become an important asset class. These emerging markets are commonly associated with high returns, high volatility, and diversification benefits for investors in developed markets. We used the Emerging Markets Data Base provided by the International Finance Corporation to examine the risk and return characteristics of emerging markets. Contrary to the results often presented in the popular press, we found that these markets have not produced high levels of compound returns relative to U.S. stock markets for the 20-year time period ending in June 1995. They have experienced a high level of volatility, but they also have consistently provided diversification benefits when combined with developed market portfolios.
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TL;DR: In this paper, the authors investigate the market valuation of earnings and book value amounts prepared under International Accounting Standards (IAS) and U.S.-GAAP to provide evidence on the debate between the SEC and the NYSE on whether foreign firms should be allowed to list in the US using IAS.
Abstract: We investigate the market valuation of earnings and book value amounts prepared under International Accounting Standards (IAS) and U.S.-GAAP to provide evidence on the debate between the U.S. SEC and the NYSE on whether foreign firms should be allowed to list in the U.S. using IAS. Our sample consists of foreign firms that adopted IAS in their primary accounts with a reconciliation to U.S.-GAAP in their Form 20-F filing. Using both price and return valuation models, we find evidence that the U.S.-GAAP earnings reconciliation adjustment is associated with market value and stock returns after controlling for IAS amounts. In addition, we find evidence that U.S.-GAAP amounts are valued differently than IAS amounts and are more highly associated with market values and security returns than IAS amounts.
TL;DR: The authors examined several explanations for human inability to detect deceptive communication when it is present and suggested that the inability to distinguish lies from truths may be a function of the decoding task presented to receivers in interpersonal communication.
Abstract: Humans lack the ability to detect deceptive communication when it is present This review examined several explanations for this state of affairs Twenty years of research in deception has shown that there is not a reliable set of nonverbal or verbal indicators of deceptive communication Moreover, human lie detectors’ veracity judgments are often affected by cognitive biases and erroneous stereotypical information about how a prototypical liar should look The current review also suggests that the inability to distinguish lies from truths may be a function of the decoding task presented to receivers in interpersonal communication Receivers of deceptive communication must reject information they have already accepted, must draw inferences of another's underlying intent, and rarely receive any feedback with regard to their inferences Additional factors that mediate lie detection accuracy are also reviewed Finally, suggestions were made regarding how scholars should proceed with future research efforts i
TL;DR: The silicon micromachined gas chromatography system (SMGCS) as mentioned in this paper is composed of a miniature sample injector that incorporates a 10/spl mu/I sample loop; a 0.9-m long, rectangular-shaped (300 /spl µ/m width and 10 /splmu/m height) capillary column coated with a 0,2-/spl cm/m thick copper phthalocyanine (CuPc) stationary phase; and a dual-detector scheme based upon a CuPc-coated chemiresistor and
Abstract: A miniature gas chromatography (GC) system has been designed and fabricated using silicon micromachining and integrated circuit (IC) processing techniques. The silicon micromachined gas chromatography system (SMGCS) is composed of a miniature sample injector that incorporates a 10 /spl mu/I sample loop; a 0.9-m long, rectangular-shaped (300 /spl mu/m width and 10 /spl mu/m height) capillary column coated with a 0,2-/spl mu/m thick copper phthalocyanine (CuPc) stationary-phase; and a dual-detector scheme based upon a CuPc-coated chemiresistor and a commercially available, 125-/spl mu/m diameter thermal conductivity detector (TCD) bead. Silicon micromachining was employed to fabricate the interface between the sample injector and the GC column, the column itself, and the dual-detector cavity. A novel IC thin-film processing technique was developed to sublime the CuPc stationary-phase coating on the column walls that were micromachined in the host silicon wafer substrate and Pyrex cover plate, which were then electrostatically bonded together. The SMGCS can separate binary gas mixtures composed of parts-per-million (ppm) concentrations of ammonia (NH/sub 3/) and nitrogen dioxide (NO/sub 2/) when isothermally operated (55-80/spl deg/C). With a helium carrier gas and nitrogen diluent, a 10 /spl mu/I sample volume containing ammonia and nitrogen dioxide injected at 40 psi (2.8 /spl times/105 Pa) ran be separated in less than 30 min.
TL;DR: In this article, a study of the relationship between students' attitudes toward women and toward gay men and lesbians and changes in those attitudes during social work courses at two universities was conducted.
Abstract: This article reports on a study of the relationship between students' attitudes toward women and toward gay men and lesbians and changes in those attitudes during social work courses at two universities. The study found a significant relationship between students' levels of homophobia and sexism. The relationship was stronger for female students than for male students and varied by race and aca demic major. The article also discusses the implications of the findings for changing social work curricula.
TL;DR: In this paper, the authors explored predictors of the police use of force in Phoenix by analyzing 1,220 arrests and employed the concept of a continuum of force, finding that the strongest predictor of police use-of-force are length of time on the force, suspect race, chemical impairment, at tempt to flee and possession of a weapon.
Abstract: There is a volume of research that has analyzed the police use of force— particularly the use of deadly force. Past research has been limited by em ploying only a dichotomous measurement of force. This paper explores predictors of the police use of force in Phoenix by analyzing 1,220 arrests. In addition, the paper employs the concept of a continuum of force. Lo gistic regression results show the strongest predictors of police use of force are length of time on the force, suspect race, chemical impairment, at tempt to flee and possession of a weapon. Relevant literature and research implications are discussed.
TL;DR: Results indicated that drinking climate combined with low cohesion resulted in increased vulnerability for all five problems, and cohesion appeared to attenuate the negative impact of exposure to drinking norms.
Abstract: Objective: While job-related alcohol use may be associated with problems for drinkers, less is known about the effects of employee drinking on co-workers. We hypothesized that either exposure to co-worker drinking or the presence of a drinking climate would positively correlate with reports of stress and other problems. Following previous research, we also predicted that work group cohesion (or team orientation) would buffer against such problems. Method: Two random samples of municipal employees (Ns = 909 and 1,068) completed anonymous surveys. These assessed individual drinking, co-worker drinking, task-oriented group cohesion, the direct reports of negative consequences due to co-worker substance use, and five problem indicators: job stress, job withdrawal, health problems, and performance (work accidents and absences). Results: In each sample, drinking climate correlated with stress and withdrawal more so than did reports of individual drinking. Drinking climate and individual job stress were negative...
TL;DR: In this paper, the authors identify a relationship dissolution script by asking men and women to list the steps that typically occur when a couple breaks up, based on approach avoidance theories of conflict and relevant relationship dissolution theories.
Abstract: Several models of relationship dissolution imply a sequence of steps or stages, for which there might exist a cultural script. Previous research has identified a script for first dates. The present research attempted to identify a relationship dissolution script by asking men and women to list the steps that typically occur when a couple breaks up. Analysis of their 1480 responses indicated a 16-step ordered script for relation-ship dissolution. The relationship dissolution script is discussed in terms of approach-avoidance theories of conflict and relevant relationship dissolution theories.
Journal Article•
TL;DR: It is revealed that 11 factors explain 71% of the variation in overall physician satisfaction and that a physician's satisfaction with a plan is closely linked to intentions to reenroll and Implications for HMOs, physicians, employers, and public policy makers are explored.
Abstract: The authors examine the issue of continuity, which is directly associated with patient satisfaction, from the perspective of the physician. They attempt to determine which factors are most important in determining physician satisfaction with an HMO and the link between satisfaction with an HMO and intent to remain affiliated with that HMO. Their study reveals that 11 factors explain 71% of the variation in overall physician satisfaction and that a physician's satisfaction with a plan is closely linked to intentions to reenroll. Implications for HMOs, physicians, employers, and public policy makers are explored.
TL;DR: In this paper, the authors investigate the relationship between corporate governance structure and diversification and find that diversified firms exhibit higher levels of pay and lower sensitivity of pay to firm performance, have more outsiders on the board, have similar sensitivity of CEO turnover to performance, and no economic difference in independent blockholdings.
Abstract: We empirically investigate the relationship between corporate governance structure and diversification. Using a sample of 199 firms beginning in 1985 and following these firms through 1994, we examine 1) if governance structure is significantly different between focused and diversified firms; 2) if differences in corporate governance are associated with the decision to become more focused or diverse; and 3) if the previously documented value loss from diversification is associated with governance structure. We find that, relative to focused firms, diversified firms exhibit higher levels of pay and lower sensitivity of pay to firm performance, have more outsiders on the board, have similar sensitivity of CEO turnover to performance, and no economic difference in independent blockholdings. We find that firms that increase their level of diversification over the sample period have governance and performance characteristics remarkably similar to firms that retain their focus. Firms that decrease their level of diversification, however, have lower insider ownership but more equity-based compensation relative to focused firms. We find no evidence that governance characteristics explain the value loss associated with diversification. We do find, however, that the fraction of outside directors in a diversified firm is positively related to firm value. Collectively, our results suggest that diversified firms use alternative governance mechanisms as substitutes for low pay-for-performance sensitivity and CEO ownership. We conclude that agency costs do not provide a complete explanation for the magnitude and persistence of the diversification discount.
TL;DR: In this article, a bis-calix[n]arenes that are singly and doubly bridged at the upper rims with 2-butenyl or 2-methylenepropyl moieties have been prepared by tandem Claisen rearrangement.
Abstract: Bis-calix[n]arenes that are singly and doubly bridged at the upper rims with 2-butenyl or 2-methylenepropyl moieties have been prepared by tandem Claisen rearrangement of bis-calix[n]arenes that are singly and doubly bridged via ether linkages at the lower rims with these same spanners. The complexation behavior of these bis-calixarenes toward C60 and C70 has been measured, and a calix[5]arene singly bridged at the upper rims with a 2-butenyl spanner and carrying allyl groups at all of the other available p-positions has been found to be particularly effective.
TL;DR: The authors found that adding gestalt principles of similarity (using colors and shapes) and proximity (using groupings) would complement the information-organization feature of knowledge maps and thereby enhance recall.
Abstract: Knowledge maps have been found to be an effective communication tool for organizing information so that it can be recalled later. It was predicted that adding gestalt principles of similarity (using colors and shapes) and proximity (using groupings) would complement the information-organization feature of knowledge maps and thereby enhance recall. The students were randomly assigned to 1 of 3 study formats (text, unenhanced maps, and enhanced maps) and were asked to study the information in them. Following a distraction task, the students completed a free-recall task. Returning 2 weeks later, the students again engaged in free recall. The students remembered more during immediate than during delayed recall, and the students who had studied enhanced maps recalled more information than the students who had studied unenhanced maps or text. The results suggest that the use of color, shape, and proximity facilitated learning by improving the organization of information.
TL;DR: A 17-item simpatia scale was developed for use with Hispanic substance abusers using confirmatory factor analytic techniques in a sample of 144 daily opioid users as discussed by the authors, and the overall scale had good internal...
Abstract: A 17-item simpatia scale was developedfor use with Hispanic substance abusers using confirmatoryfactoranalytic techniques in a sample of 144 daily opioid users. The overall scale had good internal ...
TL;DR: Observers viewed an animated ascending or descending target that varied in size and velocity across trials and appeared either to slide along one side of a single larger stationary object, or to slide between two larger stationary objects.
Abstract: Observers viewed an animated ascending or descending target that varied in size and velocity across trials and appeared either (a) in isolation, (b) to slide along one side of a single larger stationary object, or (c) to slide between two larger stationary objects. Targets vanished without warning, and displacements (i.e., differences between actual and remembered final position) along the axis of motion and orthogonal axis were measured. Forward displacement (a) decreased with increases in implied friction, (b) increased with increases in target size for descending targets, and (c) decreased with increases in target size for ascending targets. When a larger stationary object was to one side of the target, orthogonal displacement was toward that object; when no object or objects on both sides were present, orthogonal displacement was near zero. Results are consistent with previous findings and speculation on the effects of representational friction, memory averaging, and target size on memory. An observer who perceives a target moving in a consistent direction will, when subsequently asked to indicate the remembered final position of that target, usually indicate a position that suggests that the target is remembered as having traveled further than it actually did. In other words, memory for the final position of a target is usually shifted in the direction of anticipated target motion. Early explanations of this shift drew upon parallels between the physical momentum of the target and an analogous momentum within the representational system, and so the shift was referred to as representational momentum (e.g., Finke, Freyd, & Shyi, 1986; Freyd & Finke, 1984). More recent investigations suggest shifts may occur in directions other than the direction of target motion and reflect more than just an internalization of the laws of momentum. For example, memory for horizontally moving targets is also shifted downward slightly in the direction of implied gravitational attraction, a shift referred to as representational gravity. These types of shifts are now referred to by the general term displacement, and the overall displacement for a given target may be influenced by several different factors (for a review, see Hubbard, 1995b).1 Displacement is influenced by whether the target interacts with other stimuli in its surroundings; for example, the forward displacement of a horizontally moving target is decreased if the target slides along the surface of a larger stationary object (Hubbard, 1995a). A physical object that slid along the surface of a larger stationary object would experience friction, and so such decreases in forward displacement are referred to as representational friction. If representational friction results from an internalization of the laws of physical friction, and not from some unspecified factor unique to motion along the horizontal axis, then effects of representational friction should be found whenever there is contact between a moving target and some other object; for example, a vertically moving target that slides along the surface of an adjacent stationary object should exhibit less forward displacement than an equivalent vertically moving target that does not slide along the surface of an adjacent stationary object. However, whether representational friction occurs with vertical (or any other non-horizontal) motion has not been examined. Displacement may be influenced by the size of the target, but effects of target size have previously only been observed along the axis aligned with implied gravitational attraction (Hubbard, 1997). In the terrestrial environment, size, mass, and weight are highly correlated, and differences in mass are usually experienced as differences in weight. Thus, observers may respond to the implied weight, rather than the implied mass, of the target. Indeed, weight is the product of mass and (the acceleration due to) gravity, and so effects of weight should be exhibited only along the axis aligned with implied gravitational attraction. …