Researchers conducting Monte Carlo simulation studies involving covariance structure models (e.g., the common factor model) have increasingly recognized the importance of incorporating error due to ...model misfit in simulated data. Incorporating this model error acknowledges that all models are literally false, and no covariance structure model will fit perfectly in the population. Several methods for generating data from error-perturbed models have been proposed, including the Tucker, Koopman, and Linn (TKL; 1969), Cudeck and Browne (CB; 1992), and Wu and Browne (WB; 2015) model-error methods. All of these methods require user-specified parameter values that determine the degree of model misfit to be introduced. In particular, the CB and WB methods each have a single parameter that is related to the desired Root Mean Square Error of Approximation (RMSEA) value for the simulated covariance matrix. In contrast, the TLK method includes two parameter values that are generally chosen to align with values used in previous simulation studies or by testing many combinations of parameter values until solutions have RMSEA values that are close to the desired value. However, although RMSEA has often been used to indicate the degree of misfit introduced by model-error methods, RMSEA alone does not provide a complete summary of model fit. To get a more complete summary of model fit, other types of fit indices like the Comparative Fit Index (CFI) should also be used. Unfortunately, the TKL, CB, and WB model-error methods do not provide a way to specify multiple target fit indices. To address this issue, I proposed an optimization procedure that allows users to specify either a target RMSEA value, a target CFI value, or both simultaneously, and then attempts to find a combination of parameter values that produces a solution with fit indices close to the target values. To test the procedure, I conducted a simulation study using the proposed multiple-target TKL method, the CB method, and the WB method to generate error-perturbed correlation matrices for models with varying numbers of factors, items per factor, salient factor loadings, factor correlations, and target model fit indices. The results of the simulation study showed that the multiple-target TKL method was more likely than the alternative methods to lead to solutions with RMSEA and CFI values corresponding to similar qualitative levels of model fit. Moreover, the multiple-target TKL method produced solutions with RMSEA and CFI values that were closer to specified target RMSEA and CFI values than the alternative model-error methods. Thus, the multiple-target TKL method should be a useful tool for researchers who wish to generate error-perturbed correlation matrices in Monte Carlo simulation studies. To facilitate its use, I wrote an R package (noisemaker) with implementations of the multiple-target TKL method, along with implementations of the CB and WB model-error methods.
Based on the analysis of two sets of data (a cross‐sectional online survey of five product categories with an average sample size of 525 and a longitudinal telecommunications panel of more than two ...million respondents), this study detects a positive relationship between the market size (purchase penetration) of Iranian e‐brands (or websites) and the percentage of customers shared with other e‐brands. This finding is consistent with the well‐established Duplication of Purchase Law; it also holds over time and across different markets (e.g., repertoire vs. subscription). Hence, this study makes a twofold contribution to marketing knowledge. First, it expands the collection of empirical evidence concerning the Duplication of Purchase, which thus far is primarily within offline contexts and Western countries. Second, it addresses issues inherent to research on e‐loyalty, such as the over emphasis on evaluating loyalty for one e‐brand at a time via complex attitudinal measures. Accordingly, this study advances consumer buying behaviour research by clarifying that, similar to offline domains and other geographical areas, e‐loyalty in this buoyant Middle Eastern market divides across a small number of e‐brands. It is also best appraised through behavioural loyalty and by comparing multiple e‐brands competing within the same market. These outcomes translate into a series of practical guidelines for the strategic management of e‐brands, improving the practical understanding how e‐brands compete and grow.
Marijuana has been used as a traditional medicine and a pleasure-inducing drug for thousands of years around the world, especially in Asia. Δ9-Tetrahydrocannabinol, major psychoactive component of ...marijuana, has been shown to interact with specific cannabinoid receptors, thereby eliciting a variety of pharmacological responses in experimental animals and human. In 1990, the gene encoding a cannabinoid receptor (CB1) was cloned. This prompted the search for endogenous ligands. In 1992, N-arachidonoylethanolamine (anandamide) was isolated from pig brain as an endogenous ligand, and in 1995, 2-arachidonoylglycerol was isolated from rat brain and canine gut as another endogenous ligand. Both anandamide and 2-arachidonoylglycerol exhibit various cannabimimetic activities. The results of structure-activity relationship experiments, however, revealed that 2-arachidonoylglycerol, but not anandamide, is the intrinsic natural ligand for the cannabinoid receptor. 2-Arachidonoylglycerol is a degradation product of inositol phospholipids that links the function of the cannabinoid receptors with the enhanced inositol phospholipid turnover in stimulated tissues and cells. The possible physiological roles of cannabinoid receptors and 2-arachidonoylglycerol in various mammalian tissues such as those of the nervous and inflammatory cells are demonstrated. Furthermore, the future development of therapeutic drugs coming from this endocannabinoid system are discussed.
A Walk in the Garden Morris, Paul; Sawyer, Deborah
1992, 1992-05-01, Letnik:
136
eBook
This collection of essays by notable scholars offers a unique, multi-faceted approach to the understanding of the Garden story. Starting with the motifs, context, structure and language of the ...biblical text itself, the chapters trace the Jewish and Christian exegetical traditions, and developments in literature and iconography. This is an invaluable book for students and scholars of biblical studies, theology, literature, art history and the psychology of religion.
This learned volume offers a close reading of chapters 3 to 6 of the book of Amos, and attempts to locate biblical study and theological reflection within the complex cultural context of Latin ...America. The author prefaces his study with a wide-ranging survey of the continuing debate over the proper use of the Bible as a model for the structures of society. The author's particular focus is Latin America, and through sociological and textual analysis, he seeks to define the role of the prophetic biblical voice in this society and presses for a recognition of moral complexities and a constant questioning and self-evaluation from those who would claim to speak for God in society.
Umbilical cord blood (CB) is rich in hematopoietic stem/progenitor cells (SC), which have high proliferative potential. Recently, CB has been used as a source of SC transplantation. Recent results of ...cord blood transplantation (CBST) from siblings showed that CB contains sufficient numbers of SC to engraft recipients and that the transplantation of these cells was associated with a very low risk.of acute and chronic GVHD ; in Japan also, the results are promising. The New York Blood Center established a cord blood bank in 1992, and more than 500 CBSTs from unrelated donors have been performed. As a result of the success with CBST from sibling donors, a pilot bank for CB banking in Japan began in 1995 at the Kanagawa Children's Medical Center (Kanagawa Cord Blood Bank). In this report, the system of our cord blood bank is presented, and the current status of CBST, in Japan and worldwide, from related and unrelated donors is reviewed.