Evaluation of the internal structural validity of the Diagnostic and Statistical Manual of Mental Disorders (Fourth Edition) anxiety disorders in children and adolescents

The purpose of the present dissertation was to evaluate the internal validity of symptoms of four common anxiety disorders included in the Diagnostic and Statistical Manual of Mental Disorders fourth edition (text revision) (DSM-IV-TR; American Psychiatric Association, 2000), namely, separation anxiety disorder (SAD), social phobia (SOP), specific phobia (SP), and generalized anxiety disorder (GAD), in a sample of 625 youth (ages 6 to 17 years) referred to an anxiety disorders clinic and 479 parents. Confirmatory factor analyses (CFAs) were conducted on the dichotomous items of the SAD, SOP, SP, and GAD sections of the youth and parent versions of the Anxiety Disorders Interview Schedule for DSM-IV (ADIS-IV: C/P; Silverman & Albano, 1996) to test and compare a number of factor models including a factor model based on the DSM. Contrary to predictions, findings from CFAs showed that a correlated model with five factors of SAD, SOP, SP, GAD worry, and GAD somatic distress, provided the best fit of the youth data as well as the parent data. Multiple group CFAs supported the metric invariance of the correlated five factor model across boys and girls. Thus, the present study’s finding supports the internal validity of DSM-IV SAD, SOP, and SP, but raises doubt regarding the internal validity of GAD.^

Contemporary aspects of dividends: Before and during the financial crisis

The number of dividend paying firms has been on the decline since the popularity of stock repurchases in the 1980s, and the recent financial crisis has brought about a wave of dividend reductions and omissions. This dissertation examined the U.S. firms and American Depository Receipts that are listed on the U.S. equity exchanges according to their dividend paying history in the previous twelve quarters. While accounting for the state of the economy, the firm’s size, profitability, earned equity, and growth opportunities, it determines whether or not the firm will pay a dividend in the next quarter. It also examined the likelihood of a dividend change. Further, returns of firms were examined according to their dividend paying history and the state of the economy using the Fama-French three-factor model. Using forward, backward, and step-wise selection logistic regressions, the results show that firms with a history of regular and uninterrupted dividend payments are likely to continue to pay dividends, while firms that do not have a history of regular dividend payments are not likely to begin to pay dividends or continue to do so. The results of a set of generalized polytomous logistic regressions imply that dividend paying firms are more likely to reduce dividend payments during economic expansions, as opposed to recessions. Also the analysis of returns using the Fama-French three factor model reveals that dividend paying firms are earning significant abnormal positive returns. As a special case, a similar analysis of dividend payment and dividend change was applied to American Depository Receipts that trade on the NYSE, NASDAQ, and AMEX exchanges and are issued by the Bank of New York Mellon. Returns of American Depository Receipts were examined using the Fama-French two-factor model for international firms. The results of the generalized polytomous logistic regression analyses indicate that dividend paying status and economic conditions are also important for dividend level change of American Depository Receipts, and Fama-French two-factor regressions alone do not adequately explain returns for these securities.

The effect of the business cycle on the performance of socially responsible equity mutual funds

The current study applies a two-state switching regression model to examine the behavior of a hypothetical portfolio of ten socially responsible (SRI) equity mutual funds during the expansion and contraction phases of US business cycles between April 1991 and June 2009, based on the Carhart four-factor model, using monthly data. The model identified a business cycle effect on the performance of SRI equity mutual funds. Fund returns were less volatile during expansion/peaks than during contraction/troughs, as indicated by the standard deviation of returns. During contraction/troughs, fund excess returns were explained by the differential in returns between small and large companies, the difference between the returns on stocks trading at high and low Book-to-Market Value, the market excess return over the risk-free rate, and fund objective. During contraction/troughs, smaller companies offered higher returns than larger companies (ci = 0.26, p = 0.01), undervalued stocks out-performed high growth stocks (h i = 0.39, p <0.0001), and funds with growth objectives out-performed funds with other objectives (oi = 0.01, p = 0.02). The hypothetical SRI portfolio was less risky than the market (bi = 0.74, p <0.0001). During expansion/peaks, fund excess returns were explained by the market excess return over the risk-free rate, and fund objective. Funds with other objectives, such as balanced funds and income funds out-performed funds with growth objectives (oi = −0.01, p = 0.03). The hypothetical SRI portfolio exhibited similar risk as the market (bi = 0.93, p <0.0001). The SRI investor adds a third criterion to the risk and return trade-off of traditional portfolio theory. This constraint is social performance. The research suggests that managers of SRI equity mutual funds may diminish value by using social and ethical criteria to select stocks, but add value by superior stock selection. The result is that the performance of SRI mutual funds is very similar to that of the market. There was no difference in the value added among secular SRI, religious SRI, and vice screens.

Time orientation in organizations: Polychronicity and multitasking

This dissertation consists of four studies examining two constructs related to time orientation in organizations: polychronicity and multitasking. The first study investigates the internal structure of polychronicity and its external correlates in a sample of undergraduate students (N = 732). Results converge to support a one-factor model and finds measures of polychronicity to be significantly related to extraversion, agreeableness, and openness to experience. The second study quantitatively reviews the existing research examining the relationship between polychronicity and the Big Five factors of personality. Results reveal a significant relationship between extraversion and openness to experience across studies. Studies three and four examine the usefulness of multitasking ability in the prediction of work related criteria using two organizational samples (N = 175 and 119, respectively). Multitasking ability demonstrated predictive validity, however the incremental validity over that of traditional predictors (i.e., cognitive ability and the Big Five factors of personality) was minimal. The relationships between multitasking ability, polychronicity, and other individual differences were also investigated. Polychronicity and multitasking ability proved to be distinct constructs demonstrating differential relationships with cognitive ability, personality, and performance. Results provided support for multitasking performance as a mediator in the relationship between multitasking ability and overall job performance. Additionally, polychronicity moderated the relationship between multitasking ability and both ratings of multitasking performance and overall job performance in Study four. Clarification of the factor structure of polychronicity and its correlates will facilitate future research in the time orientation literature. Results from two organizational samples point to work related measures of multitasking ability as a worthwhile tool for predicting the performance of job applicants.

A Critical Review of the Implied Cost of Equity: A New Way to Estimate the Expected Return

For the last three decades, the Capital Asset Pricing Model (CAPM) has been a dominant model to calculate expected return. In early 1990% Fama and French (1992) developed the Fama and French Three Factor model by adding two additional factors to the CAPM. However even with these present models, it has been found that estimates of the expected return are not accurate (Elton, 1999; Fama &French, 1997). Botosan (1997) introduced a new approach to estimate the expected return. This approach employs an equity valuation model to calculate the internal rate of return (IRR) which is often called, 'implied cost of equity capital" as a proxy of the expected return. This approach has been gaining in popularity among researchers. A critical review of the literature will help inform hospitality researchers regarding the issue and encourage them to implement the new approach into their own studies.

Risk -taking propensity of faculty, administrators, and academic department heads at a large, urban, multi -campus community college

This research was undertaken to explore dimensions of the risk construct, identify factors related to risk-taking in education, and study risk propensity among employees at a community college. Risk-taking propensity (RTP) was measured by the 12-item BCDQ, which consisted of personal and professional risk-related situations balanced for the money, reputation, and satisfaction dimensions of the risk construct. Scoring ranged from 1.00 (most cautious) to 6.00 (most risky).^ Surveys including the BCDQ and seven demographic questions relating to age, gender, professional status, length of service, academic discipline, highest degree, and campus location were sent to faculty, administrators, and academic department heads. A total of 325 surveys were returned, resulting in a 66.7% response rate. Subjects were relatively homogeneous for age, length of service, and highest degree.^ Subjects were also homogeneous for risk-taking propensity: no substantive differences in RTP scores were noted within and among demographic groups, with the possible exception of academic discipline. The mean RTP score for all subjects was 3.77, for faculty was 3.76, for administrators was 3.83, and for department heads was 3.64.^ The relationship between propensity to take personal risks and propensity to take professional risks was tested by computing Pearson r correlation coefficients. The relationships for the total sample, faculty, and administrator groups were statistically significant, but of limited practical significance. Subjects were placed into risk categories by dividing the response scale into thirds. A 3 x 3 factorial ANOVA revealed no interaction effects between professional status and risk category with regard to RTP score. A discriminant analysis showed that a seven-factor model was not effective in predicting risk category.^ The homogeneity of the study sample and the effect of a risk-encouraging environment were discussed in the context of the community college. Since very little data on risk-taking in education is available, risk propensity data from this study could serve as a basis for comparison to future research. Results could be used by institutions to plan professional development activities, designed to increase risk-taking and encourage active acceptance of change. ^

Ethnic and American identity development: A developmental systems approach

Given the role ethnic identity has as a protective factor against the effects of marginalization and discrimination (Umaña-Taylor, 2011), research longitudinally examining ethnic identity has become of increased importance. However, successful identity development must incorporate elements from both one's ethnic group and from the United States (Berry, 1980). Despite this, relatively few studies have jointly evaluated ethnic and American identity (Schwartz et al., 2012). The current dissertation, guided by three objectives, sought to address this and several other gaps in the literature. First, psychometric properties of the Multigroup Ethnic Identity Measure (MEIM) and the American Identity Measure (AIM) were evaluated. Secondly, the dissertation examined growth trends in recently immigrated Hispanic adolescents' and their caregivers' ethnic and American identity. Lastly, the relationship between adolescents' and caregivers' ethnic and American identity was evaluated. The study used an archival sample consisting of 301 recently immigrated Hispanic families collected from Miami (N = 151) and Los Angeles (N = 150). Consistent with previous research, results in Study 1 indicated a two-factor model reliably provided better fit than a one-factor model and established longitudinal invariance for the MEIM and the AIM. Results from Study 2 found significant growth in adolescents' American identity. While some differences were found across site and nationality, evidence suggested recently immigrated Hispanic adolescents were becoming more bicultural. Counterintuitively, results found a significant decline in caregivers' ethnic identity which future studies should further examine. Finally, results from Study 3, found several significant positive relationships between adolescents' and their caregivers' ethnic and American identity. Findings provided preliminary evidence for the importance of examining identity development within a systemic lens. Despite several limitations, these three studies represented a step forward in addressing the current gaps in the cultural identity literature. Implications for future investigation are discussed.

Workplace Aggression: A Reconceptualization Of The Construct & An Exploration Of Strain Based Outcomes

The examination of Workplace Aggression as a global construct conceptualization has gained considerable attention over the past few years as organizations work to better understand and address the occurrence and consequences of this challenging construct. The purpose of this dissertation is to build on previous efforts to validate the appropriateness and usefulness of a global conceptualization of the workplace aggression construct. This dissertation has been broken up into two parts: Part 1 utilized a Confirmatory Factor Analysis approach in order to assess the existence of workplace aggression as a global construct; Part 2 utilized a series of correlational analyses to examine the relationship between a selection of commonly experienced individual strain based outcomes and the global construct conceptualization assessed in Part 1. Participants were a diverse sample of 219 working individuals from Amazon’s Mechanical Turk participant pool. Results of Part 1 did not show support for a one-factor global construct conceptualization of the workplace aggression construct. However, support was shown for a higher-order five-factor model of the construct, suggesting that it may be possible to conceptualize workplace aggression as an overarching construct that is made up of separate workplace aggression constructs. Results of Part 2 showed support for the relationships between an existing global construct workplace aggression conceptualization and a series of strain-based outcomes. Utilizing correlational analyses, additional post-hoc analyses showed that individual factors such as emotional intelligence and personality are related to the experience of workplace aggression. Further, utilizing moderated regression analysis, the results demonstrated that individuals experiencing high levels of workplace aggression reported higher job satisfaction when they felt strongly that the aggressive act was highly visible, and similarly, when they felt that there was a clear intent to cause harm. Overall, the findings of this dissertation do support the need for a simplification of its current state of measurement. Future research should continue to examine workplace aggression in an effort to shed additional light on the structure and usefulness of this complex construct.

Workplace Discrimination Climate and Team Effectiveness: The Mediating Role of Collective Value Congruence, Team Cohesion, and Collective Affective Commitment

This study explored the relationship between workplace discrimination climate on team effectiveness through three serial mediators: collective value congruence, team cohesion, and collective affective commitment. As more individuals of marginalized groups diversify the workforce and as more organizations move toward team-based work (Cannon-Bowers & Bowers, 2010), it is imperative to understand how employees perceive their organization’s discriminatory climate as well as its effect on teams. An archival dataset consisting of 6,824 respondents was used, resulting in 332 work teams with five or more members in each. The data were collected as part of an employee climate survey administered in 2011 throughout the United States’ Department of Defense. The results revealed that the indirect effect through M1 (collective value congruence) and M2 (team cohesion) best accounted for the relationship between workplace discrimination climate (X) and team effectiveness (Y). Meaning, on average, teams that reported a greater climate for workplace discrimination also reported less collective value congruence with their organization (a1 = -1.07, p < .001). With less shared perceptions of value congruence, there is less team cohesion (d21 = .45, p < .001), and with less team cohesion there is less team effectiveness (b2 = .57, p < .001). In addition, because of theoretical overlap, this study makes the case for studying workplace discrimination under the broader construct of workplace aggression within the I/O psychology literature. Exploratory and confirmatory factor analysis found that workplace discrimination based on five types of marginalized groups: race/ethnicity, gender, religion, age, and disability was best explained by a three-factor model, including: career obstruction based on age and disability bias (CO), verbal aggression based on multiple types of bias (VA), and differential treatment based on racial/ethnic bias (DT). There was initial support to claim that workplace discrimination items covary not only based on type, but also based on form (i.e., nonviolent aggressive behaviors). Therefore, the form of workplace discrimination is just as important as the type when studying climate perceptions and team-level effects. Theoretical and organizational implications are also discussed.

Workplace Aggression: A Reconceptualization of The Construct & an Exploration of Strain Based Outcomes

The examination of Workplace Aggression as a global construct conceptualization has gained considerable attention over the past few years as organizations work to better understand and address the occurrence and consequences of this challenging construct. The purpose of this dissertation is to build on previous efforts to validate the appropriateness and usefulness of a global conceptualization of the workplace aggression construct. This dissertation has been broken up into two parts: Part 1 utilized a Confirmatory Factor Analysis approach in order to assess the existence of workplace aggression as a global construct; Part 2 utilized a series of correlational analyses to examine the relationship between a selection of commonly experienced individual strain based outcomes and the global construct conceptualization assessed in Part 1. Participants were a diverse sample of 219 working individuals from Amazon’s Mechanical Turk participant pool. Results of Part 1 did not show support for a one-factor global construct conceptualization of the workplace aggression construct. However, support was shown for a higher-order five-factor model of the construct, suggesting that it may be possible to conceptualize workplace aggression as an overarching construct that is made up of separate workplace aggression constructs. Results of Part 2 showed support for the relationships between an existing global construct workplace aggression conceptualization and a series of strain-based outcomes. Utilizing correlational analyses, additional post-hoc analyses showed that individual factors such as emotional intelligence and personality are related to the experience of workplace aggression. Further, utilizing moderated regression analysis, the results demonstrated that individuals experiencing high levels of workplace aggression reported higher job satisfaction when they felt strongly that the aggressive act was highly visible, and similarly, when they felt that there was a clear intent to cause harm. Overall, the findings of this dissertation do support the need for a simplification of its current state of measurement. Future research should continue to examine workplace aggression in an effort to shed additional light on the structure and usefulness of this complex construct.

Risk-taking propensity of faculty, administrators and academic departament heads at large, urban, multicampus community college

This research was undertaken to explore dimensions of the risk construct, identify factors related to risk-taking in education, and study risk propensity among employees at a community college. Risk-taking propensity (RTP) was measured by the 12-item BCDQ, which consisted of personal and professional risk-related situations balanced for the money, reputation, and satisfaction dimensions of the risk construct. Scoring ranged from 1.00 (most cautious) to 6.00 (most risky). Surveys including the BCDQ and seven demographic questions relating to age, gender, professional status, length of service, academic discipline, highest degree, and campus location were sent to faculty, administrators, and academic department heads. A total of 325 surveys were returned, resulting in a 66.7% response rate. Subjects were relatively homogeneous for age, length of service, and highest degree. Subjects were also homogeneous for risk-taking propensity: no substantive differences in RTP scores were noted within and among demographic groups, with the possible exception of academic discipline. The mean RTP score for all subjects was 3.77, for faculty was 3.76, for administrators was 3.83, and for department heads was 3.64. The relationship between propensity to take personal risks and propensity to take professional risks was tested by computing Pearson r correlation coefficients. The relationships for the total sample, faculty, and administrator groups were statistically significant, but of limited practical significance. Subjects were placed into risk categories by dividing the response scale into thirds. A 3 X 3 factorial ANOVA revealed no interaction effects between professional status and risk category with regard to RTP score. A discriminant analysis showed that a seven-factor model was not effective in predicting risk category. The homogeneity of the study sample and the effect of a risk encouraging environment were discussed in the context of the community college. Since very little data on risk-taking in education is available, risk propensity data from this study could serve as a basis for comparison to future research. Results could be used by institutions to plan professional development activities, designed to increase risk-taking and encourage active acceptance of change.

An experimental and modelling study of the capture of CO2 from gas mixtures with different techniques, with focus on multicomponent effects.

In the present work, the deviations in the solubility of CO2, CH4, and N2 at 30 °c in the mixed gases (CO2/CH4) and (CO2/N2) from the pure gas behavior were studied using the dual-mode model over a wide range of equilibrium composition and pressure values in two glassy polymers. The first of which was PI-DAR which is the polyimide formed by the reaction between 4, 6-diaminoresorcinol dihydrochloride (DAR-Cl) and 2, 2’-bis-(3, 4-dicarboxyphenyl) hexafluoropropane dianhydride (6FDA). The other glassy polymer was TR-DAR which is the corresponding thermally rearranged polymer of PI-DAR. Also, mixed gas sorption experiments for the gas mixture (CO2/CH4) in TR-DAR at 30°c took place in order to assess the degree of accuracy of the dual-mode model in predicting the true mixed gas behavior. The experiments were conducted on a pressure decay apparatus coupled with a gas chromatography column. On the other hand, the solubility of CO2 and CH4 in two rubbery polymers at 30⁰c in the mixed gas (CO2/CH4) was modelled using the Lacombe and Sanchez equation of state at various values of equilibrium composition and pressure. These two rubbery polymers were cross-linked poly (ethylene oxide) (XLPEO) and poly (dimethylsiloxane) (PDMS). Moreover, data about the sorption of CO2 and CH4 in liquid methyl dietahnolamine MDEA that was collected from literature65-67 was used to determine the deviations in the sorption behavior in the mixed gas from that in the pure gases. It was observed that the competition effects between the penetrants were prevailing in the glassy polymers while swelling effects were predominant in the rubbery polymers above a certain value of the fugacity of CO2. Also, it was found that the dual-mode model showed a good prediction of the sorption of CH4 in the mixed gas for small pressure values but in general, it failed to predict the actual sorption of the penetrants in the mixed gas.

Diatom abundance in surface sediments of the northern North Pacific

In order to map the modern distribution of diatoms and to establish a reliable reference data set for paleoenvironmental reconstruction in the northern North Pacific, a new data set including the relative abundance of diatom species preserved in a total of 422 surface sediments was generated, which covers a broad range of environmental variables characteristic of the subarctic North Pacific, the Sea of Okhotsk and the Bering Sea between 30° and 70°N. The biogeographic distribution patterns as well as the preferences in sea surface temperature of 38 diatom species and species groups are documented. A Q-mode factor analysis yields a three-factor model representing assemblages associated with the Arctic, Subarctic and Subtropical water mass, indicating a close relationship between the diatom composition and the sea surface temperatures. The relative abundance pattern of 38 diatom species and species groups was statistically compared with nine environmental variables, i.e. the summer sea surface temperature and salinity, annual surface nutrient concentration (nitrate, phosphate, silicate), summer and winter mixed layer depth and summer and winter sea ice concentrations. Canonical Correspondence Analysis (CCA) indicates 32 species and species groups have strong correspondence with the pattern of summer sea surface temperature. In addition, the total diatom flux data compiled from ten sediment traps reveal that the seasonal signals preserved in the surface sediments are mostly from spring through autumn. This close relationship between diatom composition and the summer sea surface temperature will be useful in deriving a transfer function in the subarctic North Pacific for the quantitative paleoceanographic and paleoenvironmental studies. The relative abundance of the sea-ice indicator diatoms Fragilariopsis cylindrus and F. oceanica of >20% in the diatom composition is used to represent the winter sea ice edge in the Bering Sea. The northern boundary of the distribution of F. doliolus in the open ocean is suggested to be an indicator of the Subarctic Front, while the abundance of Chaetoceros resting spores may indicate iron input from nearby continents and shelves and induced productivity events in the study area.

Diatom abundance in surface sediments of the Southern Ocean

Based on the quantitative analysis of diatom assemblages preserved in 274 surface sediment samples recovered in the Pacific, Atlantic and western Indian sectors of the Southern Ocean we have defined a new reference database for quantitative estimation of late-middle Pleistocene Antarctic sea ice fields using the transfer function technique. The Detrended Canonical Analysis (DCA) of the diatom data set points to a unimodal distribution of the diatom assemblages. Canonical Correspondence Analysis (CCA) indicates that winter sea ice (WSI) but also summer sea surface temperature (SSST) represent the most prominent environmental variables that control the spatial species distribution. To test the applicability of transfer functions for sea ice reconstruction in terms of concentration and occurrence probability we applied four different methods, the Imbrie and Kipp Method (IKM), the Modern Analog Technique (MAT), Weighted Averaging (WA), and Weighted Averaging Partial Least Squares (WAPLS), using logarithm-transformed diatom data and satellite-derived (1981-2010) sea ice data as a reference. The best performance for IKM results was obtained using a subset of 172 samples with 28 diatom taxa/taxa groups, quadratic regression and a three-factor model (IKM-D172/28/3q) resulting in root mean square errors of prediction (RMSEP) of 7.27% and 11.4% for WSI and summer sea ice (SSI) concentration, respectively. MAT estimates were calculated with different numbers of analogs (4, 6) using a 274-sample/28-taxa reference data set (MAT-D274/28/4an, -6an) resulting in RMSEP's ranging from 5.52% (4an) to 5.91% (6an) for WSI as well as 8.93% (4an) to 9.05% (6an) for SSI. WA and WAPLS performed less well with the D274 data set, compared to MAT, achieving WSI concentration RMSEP's of 9.91% with WA and 11.29% with WAPLS, recommending the use of IKM and MAT. The application of IKM and MAT to surface sediment data revealed strong relations to the satellite-derived winter and summer sea ice field. Sea ice reconstructions performed on an Atlantic- and a Pacific Southern Ocean sediment core, both documenting sea ice variability over the past 150,000 years (MIS 1 - MIS 6), resulted in similar glacial/interglacial trends of IKM and MAT-based sea-ice estimates. On the average, however, IKM estimates display smaller WSI and slightly higher SSI concentration and probability at lower variability in comparison with MAT. This pattern is a result of different estimation techniques with integration of WSI and SSI signals in one single factor assemblage by applying IKM and selecting specific single samples, thus keeping close to the original diatom database and included variability, by MAT. In contrast to the estimation of WSI, reconstructions of past SSI variability remains weaker. Combined with diatom-based estimates, the abundance and flux pattern of biogenic opal represents an additional indication for the WSI and SSI extent.

Conical refraction with low-coherent light sources

We report on conical refraction (CR) experiments with low-coherent light sources such as light-emitting diodes (LEDs) that demonstrated different CR patterns. The change of a pinhole size from 25 to 100 μm reduced the spatial coherence of the LED radiation and resulted in the disappearance of the dark Poggendorf ring in the Lloyd's plane. This is attributed to the interference nature of the Lloyd's distribution and is found to be in excellent agreement with the paraxial dual-cone model of CR.