Total-effect Test May Erroneously Reject So-called "Full" or "Complete" Mediation

The procedure for establishing mediation, i.e., determining that an independent variable X affects a dependent variable Y through some mediator M, has been under debate. The classic causal steps require that a "total effect" be significant, now also known as statistically acknowledged. It has been shown that the total-effect test can erroneously reject competitive mediation and is superfluous for establishing complementary mediation. Little is known about the last type, indirect-only mediation, aka "full" or "complete" mediation, in which the indirect (ab) path passes the statistical partition test while the direct-and-remainder (d) path fails. This study 1) provides proof that the total-effect test can erroneously reject indirect-only mediation, including both sub-types, assuming least square estimation (LSE) F-test or Sobel test; 2) provides a simulation to duplicate the mathematical proofs and extend the conclusion to LAD-Z test; 3) provides two real-data examples, one for each sub-type, to illustrate the mathematical conclusion; 4) in view of the mathematical findings, proposes to revisit concepts, theories, and techniques of mediation analysis and other causal dissection analyses, and showcase a more comprehensive alternative, process-and-product analysis (PAPA)

TV Use and Snacking Behaviors Among Children and Adolescents in China

Television (TV) use has been linked with poor eating behaviors and obesity in young people. This study examines the association between TV watching and paying attention to TV commercials with buying and requesting snacks seen on commercials, and eating snacks while watching TV among youth in China

Metamorphism and geochronology of the spinel−cordierite granulite in the Mirror Peninsula, East Antarctica

Objective  The Prydz Bay belt in East Antarctica recorded two significant tectono-thermal events, the Grenvillian event and the Pan-African event, which are considered to be closely related to the evolution of the Rodinia and Gondwana supercontinents. However, the geological history and the tectonic nature of the two events remain controversial.   Methods  Mineralogical and petrological analyses, phase equilibria modelling and zircon geochronology are combined to investigate the spinel−cordierite granulite from the Mirror Peninsula in order to better understand the tectono-thermal history of the Prydz Bay belt.   Results  The spinel−cordierite granulite contains different stages of mineral assemblages. The major stage of mineral assemblage involves cordierite, spinel, biotite, sillimanite, K-feldspar and minor garnet and ilmenite. The later stage of mineral assemblage is indicated by the emergence of magnetite as the increasing volumes of biotite and cordierite. Minor garnet and corundum are locally preserved, implying the mineral reaction ‘g+cor→sp+sill’ and more garnet and corundum in the peak stage. The garnet grains consist of 70%−72% almandine, 20%−22% pyrope, ~4% grossularite and ~4% spessartine. The XFe (Fe2+/(Fe2++Mg2+)) of representative garnet grains ranges from 0.77 to 0.80. The spinel exhibits an XFe range from 0.80 to 0.86. Different cordierite grains have similar compositions with Al of 3.89−3.93 a.p.f.u (atoms per formula unit) and XFe of 0.32−0.36. Biotite has high TiO2 (4.13%−5.23%) and Ti (0.23−0.30 a.p.f.u). K-feldspar grains consist of 78%−85% orthoclase, 15%−23% albite and ~1% anorthite. Based on the mineral compositions and phase equilibrium modelling, the pressure−temperature (P−T) conditions of the major stage of mineral assemblage are constrained to 870−910 °C and 0.64−0.69 GPa, followed by later retrogression to 810−820°C and 0.49−0.53 GPa. A peak stage with higher P−T conditions (T>910 ℃, P>0.69 GPa) can be inferred based on the relict peak minerals and characteristic mineral compositions (e.g. Ti in biotite). Zircon grains commonly show core-mantle-rim structures in cathodoluminescence (CL) images. The LA−ICP−MS zircon U−Pb dating analyses reveal a wide age range from 613±7 Ma to 877±9 Ma (except a maximum of 916±11 Ma) for the cores. The zircon bright rims yield a weighted mean age of 526±8 Ma with a wide range of Th/U (0.06−1.23), mostly higher than 0.1.   Conclusion  Based on the results, a few conclusions can be drawn: (1) The spinel−cordierite granulite recorded medium−low pressure/high-ultrahigh temperature metamorphism with a clockwise P−T evolution path and high dT/dP. (2) The results of zircon geochronological analysis show that zircon cores mainly record U−Pb ages in the range of 800~600 Ma, younger than typical ages of Grenvillian events, which may reflect younger inherited zircon cores or significant isotopic resetting. (3) The age of ~530 Ma of zircon rims is interpreted to represent the post-peak cooling stage of the Pan-African tectono-thermal event. [Significance] This study examined the P−T conditions and the zircon ages of the spinel−cordierite granulite in the Mirror Peninsula. In combination with previous results, the P−T−t path constructed for the spinel−cordierite granulite provides new constraints on the evolution of the Prydz Bay belt during the Pan-African period

The acceptance of the clinical photographic posture assessment tool (CPPAT)

Abstract Background There is a lack of evidence-based quantitative clinical methods to adequately assess posture. Our team developed a clinical photographic posture assessment tool (CPPAT) and implemented this tool in clinical practice to standardize posture assessment. The objectives were to determine the level of acceptance of the CPPAT and to document predictors as well as facilitators of and barriers to the acceptance of this tool by clinicians doing posture re-education. Methods This is a prospective study focussing on technology acceptance. Thirty-two clinician participants (physical therapists and sport therapists) received a 3–5 h training workshop explaining how to use the CPPAT. Over a three-month trial, they recorded time-on-task for a complete posture evaluation (photo - and photo-processing). Subsequently, participants rated their acceptance of the tool and commented on facilitators and barriers of the clinical method. Results Twenty-three clinician participants completed the trial. They took 22 (mean) ± 10 min (SD) for photo acquisition and 36 min ± 19 min for photo-processing. Acceptance of the CPPAT was high. Perceived ease of use was an indirect predictor of intention to use, mediated by perceived usefulness. Analysis time was an indirect predictor, mediated by perceived usefulness, and a marginally significant direct predictor. Principal facilitators were objective measurements, visualization, utility, and ease of use. Barriers were time to do a complete analysis of posture, quality of human-computer interaction, non-automation of posture index calculation and photo transfer, and lack of versatility. Conclusion The CPPAT is perceived as useful and easy to use by clinicians and may facilitate the quantitative analysis of posture. Adapting the user-interface and functionality to quantify posture may facilitate a wider adoption of the tool

The Impact of Brand Quality on Shareholder Wealth

This study examines the impact of brand quality on three components of shareholder wealth: stock returns, systematic risk, and idiosyncratic risk. The study finds that brand quality enhances shareholder wealth insofar as unanticipated changes in brand quality are positively associated with stock returns and negatively related to changes in idiosyncratic risk. However, unanticipated changes in brand quality can also erode shareholder wealth because they have a positive association with changes in systematic risk. The study introduces a contingency theory view to the marketing-finance interface by analyzing the moderating role of two factors that are widely followed by investors. The results show an unanticipated increase (decrease) in current-period earnings enhances (depletes) the positive impact of unanticipated changes in brand quality on stock returns and mitigates (enhances) their deleterious effects on changes in systematic risk. Similarly, brand quality is more valuable for firms facing increasing competition (i.e., unanticipated decreases in industry concentration). The results are robust to endogeneity concerns and across alternative models. The authors conclude by discussing the nuanced implications of their findings for shareholder wealth, reporting brand quality to investors, and its use in employee evaluation

Assumptions behind Intercoder Reliability Indices

Inter-coder reliability is the most often used quantitative indicator of measurement quality in content studies. Researchers in psychology, sociology, education, medicine, marketing and other disciplines also use reliability to evaluate the quality of diagnosis, tests and other assessments. Many indices of reliability have been recommended for general use. This article analyzes 22, which are organized into 18 chance-adjusted and four non-adjusted indices. The chance-adjusted indices are further organized into three groups, including nine category-based indices, eight distribution-based indices, and one that is double based, on category and distribution. The main purpose of this work is to examine the assumptions behind each index. Most of the assumptions are unexamined in the literature, and yet these assumptions have implications for assessments of reliability that need to be understood, and that result in paradoxes and abnormalities. This article discusses 13 paradoxes and nine abnormalities to illustrate the 24 assumptions. To facilitate understanding, the analysis focuses on categorical scales with two coders, and further focuses on binary scales where appropriate. The discussion is situated mostly in analysis of communication content. The assumptions and patterns that we will discover will also apply to studies, evaluations and diagnoses in other disciplines with more coders, raters, diagnosticians, or judges using binary or multi-category scales. We will argue that a new index is needed. Before the new index can be established, we need guidelines for using the existing indices. This article will recommend such guidelines.Statistic

The Digital Economy and Carbon Productivity: Evidence at China’s City Level

Based on the panel data of 285 prefecture-level cities in China, this paper empirically tests the impact of digital economic development on carbon productivity by using a two-way fixed effect model, intermediary mechanism model and threshold mechanism model. The results show that: (1) the digital economy can significantly improve carbon productivity, and this conclusion is still valid after a series of robustness tests. (2) An intermediary mechanism test found that technological innovation, reducing energy consumption intensity and improving urban productivity are the three primary paths through which the digital economy significantly improves carbon productivity. (3) A threshold mechanism test found that the promotion effect of the digital economy on carbon productivity is also affected by the degree of marketization and the level of human capital, showing a single threshold effect and a U-shaped trend. (4) The impact of the digital economy on carbon productivity has regional heterogeneity, urban agglomeration heterogeneity, and resource-based city heterogeneity. This study provides substantial empirical evidence for the relevant authorities to formulate green development policies from the perspective of digital economy development