I suggest for memorization an equation for calculating approximate sample size requirements intended only for a specific set of values (80 per cent power for a two-tailed alpha = 0.05 test) which seems to occur often in biopharmaceutical research. After presenting the formula in terms of variance estimate s2 and effect size d, I derive a few alternative forms and then discuss the accuracy of th...

Competition for foreign direct investment (FDI) among developing countries has intensified in recent years. Using a sample of 68 developing countries across dif ferent regions, with data from 1975-2005, this paper investigates whether Latin America and the Caribbean (LAC) dif fers from non-LAC regions in regard to determinants of FDI; the evidence suggests that there are dif ferences. In partic...

A differentiation-inducing factor (DIF) for the promyelocytic HL-60 cell line is constitutively produced by the malignant T lymphocyte line HUT-102. DIF was highly purified from HUT-102-conditioned media by means of diethylaminoethanol (DEAE)-chromatography, gel chromatography, and high-resolution, ion-exchange chromatography on a MonoQ column and sodium dodecyl sulfate-polyacrylamide gel elect...

Objective. The present study uses simulated data to find what the optimal number of response categories is to achieve adequate power in ordinal logistic regression (OLR) model for differential item functioning (DIF) analysis in psychometric research. Methods. A hypothetical ten-item quality of life scale with three, four, and five response categories was simulated. The power and type I error ra...

Differential item functioning (DIF) occurs when an item on a test or questionnaire has different measurement properties for 1 group of people versus another, irrespective of mean differences on the construct. This study focuses on the use of multiple-indicator multiple-cause (MIMIC) structural equation models for DIF testing, parameterized as item response models. The accuracy of these methods,...

In emergency responses to natural disasters, actionable information provided by remote sensing images is crucial help managers become aware of the situation and assess magnitude damage. Without accurate prediction time consumption, choosing an algorithm for land use/land cover (LULC) classification under these circumstances could be blind subjective. Here, we proposed a full parameter complexit...

Differentiation-inducing factor-3 (DIF-3), found in the cellular slime mold Dictyostelium discoideum, and its derivatives such as butoxy-DIF-3 (Bu-DIF-3) are potent anti-tumor agents. However, the precise mechanisms underlying the actions of DIF-3 remain to be elucidated. In this study, we synthesized a green fluorescent derivative of DIF-3, BODIPY-DIF-3, and a control fluorescent compound, Bu-...

Previous researchers in knowledge-based systems verification have concentrated on developing various approaches and computational tools to find errors in knowledge bases . However , unlike software engineering for traditional systems , there has been little investigation of the relationship between errors and system size . In addition , there has been little analysis of the relationship between...