Greater Explanatory Power Research Articles

This mechanistic step is “productive”: organic chemistry students' backward-oriented reasoning

If an organic chemistry student explains that she represents a mechanistic step because “it's a productive part of the mechanism,” what meaning could the professor teaching the class attribute to this statement, what is actually communicated, and what does it mean for the student? The professor might think that the explanation is based on knowledge of equilibria of alternative steps. The professor might also assume that the student implies information about how one of the alternatives influences the energetics of subsequent steps or how subsequent steps influence the equilibria of the alternatives. Meanwhile, the student might literally mean that the step is represented simply because it leads to the product. Reasoning about energetic influences has much greater explanatory power than teleological reasoning taking the consequence of mechanistic steps as the reason for their prediction. In both cases, however, the same backward-oriented reasoning is applied. Information about subsequent parts in the mechanism is used to make a decision about prior parts. To qualitatively compare the reasoning patterns and the causality employed by students and expected by their professor, we used a mechanistic approach from philosophy of science that mirrors the directionality of a mechanism and its components: activities, entities, and their properties. Our analysis led to the identification of different reasoning patterns involving backward-oriented reasoning. Participants' use of properties gave additional insight into the students' reasoning and their professor's expectations, which supports the necessity for clear expectations in mechanistic reasoning in organic chemistry classrooms. We present a framework that offers a lens to clarify these expectations and discuss implications of the framework for improving student mechanistic reasoning in organic chemistry.

Measuring the contribution of academic and general vocabulary knowledge to learners' academic achievement

The Academic Word List (AWL) (Coxhead, 2000) is widely used in preparing non-native speakers for academic courses, and it is thought that the words in this list are essential for the understanding of English academic texts (Cobb & Horst, 2004). It is also thought that the AWL is a list of infrequent and specialised words inaccessible from general language. These preconceptions are challenged in the current study. With reference to BNC/COCA word lists, the study demonstrates that the majority of the words from the AWL fall within the 3000 most frequent words, a grouping that Schmitt and Schmitt (2014) describe as highly frequent. Using a specifically created test of the AWL and a test of overall vocabulary size (XK-Lex; Masrai & Milton, 2012), the study demonstrates that the learning of the AWL appears to be strongly influenced by the frequency of these words in general corpora and that the AWL test very strongly resembles a test of overall vocabulary size. Knowledge of the AWL also adds marginally to the power of overall vocabulary size in explaining variance in grade point average (GPA) scores. This conclusion matches that of Townsend, Filippini, Collins, and Biancarosa (2012), although the tests in the current study appear to have greater explanatory power.

Estrés percibido y quejas subjetivas de memoria en adultos jóvenes: papel mediador de las funciones ejecutivas

Previous studies have shown that executive functions can be mediators between perceived stress and subjective memory complaints. However, it has not been evaluated which executive functions are those that most mediate this relationship. To determine if executive functions have a mediating role in the relationship between perceived stress and subjective memory complaints, and which ones have the greatest explanatory power. The sample consisted of 743 university students (76.4% women), with an average age of 22.24 ± 3.64 years. The subjective memory complaints were evaluated with the Memory Failure of Everyday Questionnaire, the stress with the Perceived Stress Scale, and the executive functions with the Prefrontal Symptoms Inventory. The executive functions and the perceived stress explained altogether 57% of the subjective memory complaints, being the attentional problems and the executive control problems the two variables with a greater weight in the model. On the other hand, the executive control problems, attentional problems and social behaviour problems showed a mediating effect between perceived stress and subjective memory complaints. The executive control problems and the attentional problems could be factors of choice for clinical intervention, since they act on their own as generators of subjective memory complaints and, moreover, are involved in mediation processes of perceived stress.

Endogenous dynamics of innovation networks in the German automotive industry: analysing structural network evolution using a stochastic actor-oriented approach

The generation of innovation is well known to be a social process depending on mutual interactions, aiming at accessing and exchanging knowledge in order to generate novel goods and services. Accordingly, interest in interfirm innovation networks has increased sharply over the last decade. Preceding research indicates that the structural dynamics of networks is driven both by endogenous and exogenous forces. In particular, we focus on the role of the endogenous determinants of the network evolution of interfirm networks - a category of often underestimated forces. We employ a longitudinal dataset that comprises German automotive firms' performance between 2002 and 2006 and apply a stochastic actor-oriented model (SAOM) designed to analyse both the endogenous and exogenous determinants of network change. Our results show that endogenous determinants - approximated by measures for local and global clustering - exhibit greater explanatory power than exogenous firm characteristics such as age, size, and R&D activity.

Obesidade e associação de indicadores antropométricos com fatores de risco em professores

The aim of this study was to verify general and central obesity, as well as the association of anthropometric indicators with cardiovascular risk factors (CvRF) in teachers of the private network of Viçosa-MG. A cross-sectional observational study was conducted with 150 teachers. Body mass index (BMI), conicity index (CI), body adiposity index (BAI), waist-to-hip ratio (WHR), waist-to-height ratio (WHtR), waist circumference (WC), abdominal circumference (AC) and body fat percentage (%BF); systolic blood pressure (SBP) and diastolic blood pressure (DBP); glycemia (GL), total cholesterol (TC), high density lipoprotein (HDL-C), low density lipoprotein (LDL-C) and triglycerides (TG) were evaluated. The prevalence of general and central obesity was calculated in addition to the simple linear regression to verify the association of anthropometric indicators between themselves and with CvRF. General and central obesity was identified in 19% and 17% of teachers respectively. The best associations between anthropometric indicators were between BMI and WHtR (R² = 0.81), WHtR and AC (R² = 0.78) and BMI and AC (R² = 0.76), all of which were positive. Between anthropometric indicators and CvRF, the best associations were found between WHtR and TG (R² = 0.25), AC and SBP (R² = 0.18) and WHR and HDL-c (R² = 0.19), the first two associations being positive and the last negative. It was concluded that approximately one in five teachers presented obesity. The general obesity indicator, BMI, was positively associated with anthropometric indicators and with most CvRF. However, central obesity indicators presented greater explanatory power on CvRF.

Combining sensory evaluations and experimental auctions to assess consumers’ preferences for fresh fruit quality characteristics

AbstractA combination of sensory evaluation and experimental auctions was used to analyze consumer preferences for external and internal quality characteristics of two fresh apple varieties “Honeycrisp” and “Gala.” A group of 384 panelists in three locations in the United States evaluated the appearance, the internal quality characteristics, in three sequential rounds, for the two apple variety samples. Each panelist responded to a sensory evaluation questionnaire, and then bid on the samples in an incentive compatible second price auction. We found that panelists’ bids increased with the amount of information given. Also, we found that for some attributes such as sweetness, panelists preferred levels closer to their ideal rather than objectively measured higher levels. When evaluating consumers’ preference and valuation for different fresh fruit varieties, a greater explanatory power is obtained when including an indicator variable for the variety along with the set of quality attributes. The indicator variable could improve the control of inherent factors related with the varieties but cannot be observed or inferred easily. Finally, our findings add to previous studies in that flavor, when expressed as a combination of sweetness and acidity in addition to textural attributes, are important determinants of consumers’ acceptance. [EconLit citations: Q13]

Climate and rapid local adaptation as drivers of germination and seed bank dynamics of Alliaria petiolata (garlic mustard) in North America

Summary Local differences in climate conditions may facilitate rapid evolutionary changes in introduced plants to optimize timing of germination or ability to survive in seed banks, which may constitute beneficial demographic adaptations during range expansions. Understanding differences in germination requirements and emergence patterns across a species’ range is critical for demographic modelling and potential invasive species control efforts. We assessed germination responses of Alliaria petiolata using seeds collected from 10 populations spanning much of the North American distribution of the species. We compared germination responses under different stratification regimes in a growth chamber over 2·5 years, and evaluated seedling emergence in a common garden in Ithaca, New York over 13 years. We further evaluated how climate overlap between Ithaca and original collection sites influenced emergence patterns. In the laboratory, germination of all populations was similar and highest at 4 °C stratification. Seeds exposed to sub‐zero temperatures delayed germination and population responses were variable. In the common garden, seedlings from most populations emerged over 13 years, and emergence patterns were strongly influenced by population. Annual emergence was positively correlated with spring temperature and inversely correlated with number of spring days with minimum temperature below freezing. Climate overlap between the common garden and original collection location enhanced germination, but common garden climate conditions over the course of the 13‐year experiment and population identity had greater explanatory power. Synthesis. Laboratory germination tests did not reflect seedling emergence under field conditions. After 150 years of residence time in North America, Alliaria petiolata populations have developed striking differences in their responses to local climates and stratification requirements suggesting that a complex interplay of pre‐adaptation, rapid evolutionary changes, and phenotypic plasticity result in locally adapted populations.

Internet Banking Adoption in South Africa: The Mediating Role of Consumer Readiness

The recent rapid development of Internet banking (IB) around the world is not without certain challenges. For instance while a majority of banking SSTs (Self Service Technologies, e.g. ATMs and debit cards) have been well received by the South African market, consumers seem sceptical towards Internet banking. This paper seeks to test various conceptual frameworks of consumer adoption patterns of IB with the view of a framework with the greatest explanatory power for the South African market. To achieve the stated objective of a framework for IB adoption in South Africa, this paper suggests an approach not yet undertaken, according to the literature review conducted, within the South African retail banking industry – investigating a comparison of the predictive efficacy of two common groupings of variables most cited in the consumer behaviour literature as important determinants of adoptive behaviour in SSTs. These are: perceptions of innovation characteristics and consumer readiness (CR) variables. Therefore, the primary objective of this article is the consideration of this gap within the body of knowledge around South African consumers’ IB adoption behaviour. Through a descriptive quantitative analysis of 1516 large sample size, innovation characteristics as consumer’s perceptions (complexity, perceived risk notably) or views (endogenous variables) were found with greatest predictive power over IB adoption, in the South African consumer market context. This finding is therefore for marketers (particularly in South Africa) a set of useful tools that can be relevant to promote the adoption of IB.

Internet Banking Adoption in South Africa: The Mediating Role of Consumer Readiness

The recent rapid development of Internet banking (IB) around the world is not without certain challenges. For instance while a majority of banking SSTs (Self Service Technologies, e.g. ATMs and debit cards) have been well received by the South African market, consumers seem sceptical towards Internet banking. This paper seeks to test various conceptual frameworks of consumer adoption patterns of IB with the view of a framework with the greatest explanatory power for the South African market. To achieve the stated objective of a framework for IB adoption in South Africa, this paper suggests an approach not yet undertaken, according to the literature review conducted, within the South African retail banking industry – investigating a comparison of the predictive efficacy of two common groupings of variables most cited in the consumer behaviour literature as important determinants of adoptive behaviour in SSTs. These are: perceptions of innovation characteristics and consumer readiness (CR) variables. Therefore, the primary objective of this article is the consideration of this gap within the body of knowledge around South African consumers’ IB adoption behaviour. Through a descriptive quantitative analysis of 1516 large sample size, innovation characteristics as consumer’s perceptions (complexity, perceived risk notably) or views (endogenous variables) were found with greatest predictive power over IB adoption, in the South African consumer market context. This finding is therefore for marketers (particularly in South Africa) a set of useful tools that can be relevant to promote the adoption of IB.

Short Selling and Economic Policy Uncertainty

We study the trading behavior of short sellers in the presence of economic policy uncertainty (EPU). Daily short selling activity at either the aggregate level or the individual stock level is increasing in the EPU index (Baker, Bloom and Davis, 2016). EPU has great explanatory power for short trading. Cross-sectional tests show that the increase in short interest under high political uncertainty is from shorting stocks characterized by higher mispricing, greater policy sensitivity, higher illiquidity, greater volatility or analyst dispersion. Short sellers earn abnormal profits by trading on public information related to EPU.

Litter thickness, but not root biomass, explains the average and spatial structure of soil hydraulic conductivity in secondary forests and coffee agroecosystems in Veracruz, Mexico

Secondary forests and coffee agroecosystems are considered good alternatives for conservation of a high capacity for water filtration in the soil where tropical montane cloud forests (TMCF) once grew; however, it is not clear which characteristics of the vegetation modulate the field saturated hydraulic conductivity of the soil (Kfs) and whether these characteristics persist in such derived systems. Here, we explore how changes in vegetation between secondary forests and coffee agroecosystems have consequences for the average value and spatial variation of litter thickness and root biomass, and whether these differences can explain the Kfs and its spatial distribution. We found that the thickest litter, greatest total biomass and thickest roots are in the secondary forest of the north of the study area. The litter is spatially structured in patches of ca. 12m at plot scale in the secondary forest and coffee agroecosystem of the southern area. Like the Kfs, the thickness of the litter and biomass of the thick (>2mm), medium (1–2mm) and fine (<1mm) roots are spatially distributed on a north to south gradient at landscape scale. Our linear model indicates that geographic area (north or south), land use and litter thickness explain the Kfs and its spatial distribution along this gradient. Even on inclusion of the antecedent soil moisture and percentage of clays (found to explain Kfs in a previous study), it was not possible to eliminate from the model geographic area and land use, due to their high explanatory power. However, antecedent soil moisture became redundant on inclusion of the litter layer, which had a greater explanatory power. Our modeling suggests that undiscovered differences prevail between the geographic areas and secondary forest and coffee agroecosystems (possibly related to the edaphogenesis and management practices) that determine the Kfs.

The Frontal Sinus Cavity Exhibits Sexual Dimorphism in 3D Cone-beam CT Images and can be Used for Sex Determination.

Few studies have assessed the use of the frontal sinus cavities for sex differentiation. In this study, a new methodology was used to assess the reliability of CBCT images of the frontal sinus cavity for determining sex based on the sexual dimorphism found in this anatomical structure. The survey sample consisted of 130 scans that were reconstructed three-dimensionally. 3D images of the cavity volume in the frontal, lateral, and basal views were exported in TIFF. The following variables were measured in a second program: area, perimeter, bounding rectangle, ellipse fit, circularity, aspect ratio, roundness, solidity, and Feret's diameter. The methodology demonstrated the existence of sexual dimorphism with an accuracy of 80.0% in the logistic regression model. The basal view had the greatest explanatory power in the final model. This methodology may be used as an alternative way of determining a reliable biological profile during the analysis of skeletal remains.

Urban Economic Openness and IPO Underpricing

This paper represents a first attempt to employ a macroeconomic approach to explain the high and varying IPO underpricing within a single emerging market. We examine the empirical impact of trade openness on the short-run underpricing of initial public offerings (IPOs) using city-level data. Particularly, we argue that urban economic openness (UEO) has a significant impact on the productivity and on prices of both direct and indirect real estate due to productivity gains of companies in more open areas. This in turn positively affects the firm’s profitability, enhancing the confidence in local real estate markets and future company performance, hence decreasing the uncertainty of the IPO valuation. As a result, issuers have less incentive to underprice IPO shares. We use a sample of Chinese real estate IPOs, which offer a suitable laboratory thanks to their strong geographic investment patterns focused locally and a country with a highly heterogeneous openness across regions. Controlling for traditional firm- and issuing-specific characteristics of IPOs that are used for developed markets and Chinese-related features (i.e. listing location and state ownership), we find the evidence that companies investing in economically more open areas experience less IPO underpricing. Our results show great explanatory power and are robust to different specifications.

Randomness or stock–flow: which mechanism describes labour market matching in Poland?

ABSTRACTI identify which theoretical model (random, stock–flow, or job queuing) best describes the matching mechanism in the labour market in Poland. The purpose of this work is to formulate policy recommendations aimed at increasing the number of matches. I use monthly registered unemployment data for the period January 1999–June 2013 and econometrically correct for temporal aggregation bias in the data. I extend known solutions and apply them directly to a job queuing model. Job seekers (from the pool) seek work among old and new job posts, but only a small fraction of the newly unemployed individuals find work quickly. Vacancies are the driving force in aggregate hiring, but the inflow is more important than the stock. The random model has greater explanatory power, although the results do not negate the non-random model. Hence, better information and higher inflows (especially of job offers) should facilitate matching.

Etiology in psychiatry: embracing the reality of poly-gene-environmental causation of mental illness.

Intriguing findings on genetic and environmental causation suggest a need to reframe the etiology of mental disorders. Molecular genetics shows that thousands of common and rare genetic variants contribute to mental illness. Epidemiological studies have identified dozens of environmental exposures that are associated with psychopathology. The effect of environment is likely conditional on genetic factors, resulting in gene-environment interactions. The impact of environmental factors also depends on previous exposures, resulting in environment-environment interactions. Most known genetic and environmental factors are shared across multiple mental disorders. Schizophrenia, bipolar disorder and major depressive disorder, in particular, are closely causally linked. Synthesis of findings from twin studies, molecular genetics and epidemiological research suggests that joint consideration of multiple genetic and environmental factors has much greater explanatory power than separate studies of genetic or environmental causation. Multi-factorial gene-environment interactions are likely to be a generic mechanism involved in the majority of cases of mental illness, which is only partially tapped by existing gene-environment studies. Future research may cut across psychiatric disorders and address poly-causation by considering multiple genetic and environmental measures across the life course with a specific focus on the first two decades of life. Integrative analyses of poly-causation including gene-environment and environment-environment interactions can realize the potential for discovering causal types and mechanisms that are likely to generate new preventive and therapeutic tools.

Capitalist diversity and compliance: economic reforms in Central and Eastern Europe after EU accession

ABSTRACT This paper investigates whether different capitalist varieties in Central and Eastern Europe have different records of post-accession compliance. Drawing on an explorative cluster analysis of 25 EU member states and additional case study evidence, its results suggest that there are two broader clusters of Central and East European countries, which are associated with different Varieties of Capitalism and privilege certain explanatory factors for (non-) compliance over others: I identify a cluster comprising the Baltic States and Slovakia that leans toward a liberal market economy type. I argue that post-accession compliance processes in this cluster are dominated by market-based modes of coordination, in which government ideologies and effectiveness gain greater explanatory power. The second cluster is associated with coordinated market economies marked by a more inclusive political process that privileges the interplay of preferences of various state and non-state actors to explain compliance after EU accession.

Abstract IA17: How does Cultural Equivalence Impact Asian American Cancer Survivors?

Abstract Introduction Over 1,500 studies are in Medline today on the psychosocial impact and quality of life (QOL) of breast cancer (BC) survivors. Only a small percentage of these studies have been conducted with women of color, yet most of these studies appear to use the same psycho-social theories for intervention and outcomes, developed and validated with non-Hispanic white women. This assumed universality of (EA) cultural beliefs and practices undermines the importance of cultural differences in cancer research. Often standardized questionnaires are tested for reliability in diverse groups with an α score, but many validated scales have rarely been tested for cross-cultural equivalence of concepts and metrics in diverse populations. The absence of research exploring and testing the cross cultural equivalence of EA developed concepts, such as, self-integrity and well-being of BC survivors thwarts our ability to effectively address the QOL of diverse populations, and hinders our ability to promote health equity. Therefore, this presentation will first briefly present a consensus definition of culture, second, discuss the general lack of attention to cross-cultural equivalence of concepts and measures used in cancer survivor research, last, present an example of a mixed paradigm and mixed method study designed to identify and test such potential cultural differences in among Asian American (AA) breast cancer (BC) survivors. AA BC survivors are reported to suffer significant emotional and social problems, but do not avail themselves of existing and available EA based services, even if they have been in the U.S. for multiple generations and/or are proficient in English. Yet, few studies have been conducted to identify why AA BC survivors do not use existing support services and how to better design high-quality programs that provide that needed support. Breast cancer support groups are designed to increase self-integrity, and well-being, but the cross-cultural equivalence of concepts of self-integrity and well-being have not been tested in breast cancer survivorship. Study Design This mixed paradigm and mixed method study was developed to 1) test the cultural equivalence and validity of standard measures of distress and well-being in order to investigate such potential cultural differences in the BC survivorship experience among three groups of Asian American women in three different geographic areas, 2) identify potential cultural differences in their perceptions of the cancer experience and degree of satisfaction with their strategies to manage the experience by providing context and meaning to our deductive findings, and 3) test if the cultural specific constructs and measures provide greater explanatory power to the QOL of the AA women than the set of standardized tools currently used. We conducted, in depth ethnographic interviews with 35 key informants, 118 BC survivors and 57 family members. We also surveyed 450 Chinese-, Japanese-, Vietnamese- and European American BC survivors. Implications for Health Disparities Research in Cancer The findings from this study will demonstrate how mixed-paradigms and methods are essential to develop a culturally informed understanding of the lives of women with cancer from diverse cultural backgrounds. Such study designs are crucial to inform the science and practice of BC survivorship in AA communities by mobilizing more culturally appropriate assessment tools built on culturally valid concepts and constructs. Such tools may aid in designing culturally grounded and congruent programs that more adequately meet the needs of those in underrepresented communities, and, thereby, improve the QOL of BC survivors from diverse populations as well as facilitate the elimination of health disparities. Citation Format: Marjorie Kagawa-Singer. How does Cultural Equivalence Impact Asian American Cancer Survivors? [abstract]. In: Proceedings of the Ninth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2016 Sep 25-28; Fort Lauderdale, FL. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2017;26(2 Suppl):Abstract nr IA17.

Security-related factors in extended UTAUT model for NFC based mobile payment in the restaurant industry

This study aims to provide an integrated model that examines the determinants of near-field communication (NFC) based mobile payment (MP) technology acceptance in the restaurant industry. The proposed model, which combines the unified theory of acceptance and use of technology (UTAUT) and technology acceptance model (TAM), was tested via structural equation modeling (SEM) by using data collected from 412 restaurant customers. The study results indicated that the proposed model provides approximately 20% greater explanatory power and predictive accuracy than the original UTAUT model and demonstrates strong evidence of the effects of risk, security, and trust on customers' intentions to use NFC-based MP technology in restaurant settings. In addition, considering the total effect, attitude, security, and risk have the most substantial impact on customers’ behavioral intentions. The study results further demonstrate that risk, security, and trust are also important determinants, with direct and indirect impacts, of other critical constructs (i.e., effort expectancy, hedonic and utilitarian performance expectancy, attitude, and intention). The empirical findings provide valuable theoretical contributions for researchers and practical implications for restaurant operators and technology vendors by explaining the reasons as to why the NFC-based MP is not popular in North American restaurants.

Environmental factors related to biogeographical transition zones of areas of endemism of Neotropical mammals

Biogeographical transition zones are areas of a complex biotic mixture located at the borders between biogeographical units. Climatic, physical and ecological factors should play an important role in allowing coexistence of different biotic elements in the transition zone. Here, we explore the relationship between environmental factors and biogeographical transition zones, defined by Neotropical mammal distributions, by a model selection approach based on the Akaike information criterion and accounting for the spatial structure in the data. We detected three areas of high overlap between mammalian areas of endemism. Two of them corresponded to the well-established regional-level transition zones, namely Mexican (MTZ) and South American (SATZ) transition zones; the third was one located in south-eastern Brazil, approximately between the Paraná and Chacoan dominion that we call The Atlantic Forest integration zone (AF). Only one explicative variable was shared by the three transitions zones (precipitation of the warmest quarter). However, shared variables with great explanatory power indicated two environmental aspects as facilitators for the coexistence of different biotic components in a given geographical area. The first one was the heterogeneity component, either topographic for the SATZ and MTZ or climatic for the AF. The second one was related non-extreme thermal conditions: precipitation of the warmest quarter, interpreted as a thermal buffer, shared by AF and SATZ, and isothermality shared by MTZ and SATZ.

ВАРИАТИВНОСТЬ АНГЛИЙСКОГО И РУССКОГО ЯЗЫКОВ В СВЕТЕ ЛИНГВИСТИЧЕСКОЙ КОНЦЕПЦИИ Г.П. МЕЛЬНИКОВА

The article presents the authors’ attempt to explain the territorial and demographic impera-tive of the English language and variability of the Russian language from the position of the linguistic theory of Russian scientist G. P. Melnikov. According to the founder of the theory of World Englishes at the present time in there is no any appropriate methodological basis for the explanation of the English language’s “triumphal march” in linguistics. Many works devoted to the variation of the Russian language, as well as English are not considered from the standpoint of systemic linguistics. It appears to the authors that a sys-tematic approach G. P. Melnikov has great explanatory power in the issue of linguistic vitality of these two languages. The authors rely on the concept of internal determinant as a specific attribute of the system developing in the direction of optimal adaptation to the completion of the super-system functional request and the external determinant that conditions functional requirements of the super-system. The article con-tains the language situations analysis of the Russian language as a language with event determinant and the language situations analysis of the English language as a language with occasional determinant.