Application of colour metallography in the examination of ancient metals

The use of colour in the metallographic examination of ancient metals is useful both for research and teaching purposes. Application of different optical methods of examination include: polarized light, with or without a first-order red compensator, and differential interference contrast microscopy (DIC). The use of DIC can be combined with the other techniques mentioned in the text for the examination of etched or unetched metal surfaces, which are best observed microscopically using a metallograph. Colour techniques are now used routinely in industrial metallography, and are available for a variety of metals and alloys. Colour tint etching can be used to enhance grain structure or different phases present in the metallic artefact which may not be visible in conventional etched samples, or which lack optical contrast. Many more applications of these techniques in the examination of ancient metals will be published in the literature as they become better known and second-hand equipment with DIC lenses enter the market at a price suitable for conservation laboratories to purchase them.     

Cut points of the Actigraph GT9X for moderate and vigorous intensity physical activity at four different wear locations

ABSTRACT

Accelerometer cut points are an important consideration for distinguishing the intensity of activity into categories such as moderate and vigorous. It is well-established in the literature that these cut points depend on a variety of factors, including age group, device, and wear location. The Actigraph GT9X is a newer model accelerometer that is used for physical activity research, but existing cut points for this device are limited since it is a newer device. Furthermore, there is not existing data on cut points for the GT9X at the ankle or foot locations, which offers some potential benefit for activities that do not involve arm and/or core motion. A total of N = 44 adults completed a four-stage treadmill protocol while wearing Actigraph GT9X sensors at four different locations: foot, ankle, wrist, and hip. Metabolic Equivalent of Task (MET) levels assessed by indirect calorimetry along with Receiver Operating Characteristic (ROC) curves were used to establish cut points for moderate and vigorous intensity for each wear location of the GT9X. Area under the ROC curves indicated high discrimination accuracy for each case.     

Factors Influencing Information Literacy Competency of College Students

This paper analyzes multiple factors from current university students' high school experiences, including demographic, educational, and economic factors, and current standing and grade point average (GPA), to evaluate the students' information literacy skills associated with a 1000 level course on information literacy which is part of the university's general education requirement. The pre-test indicates that students lack sufficient skills needed to do college-level research. Results of regression analyses demonstrate that only current university GPA and standardized test scores have any influence on information literacy test scores.     

Profitably Bundling Information Goods: Evidence From the Evolving Video Library of Netflix

Using a unique dataset of the Netflix video on demand library, this article measures the characteristics of information goods important when employing a strategic bundling strategy. By matching the titles entering and exiting the library to their relevant properties, I use a characteristic approach to determine when the value to Netflix of adding a title exceeds the licensing fee and when the displacement effect associated with presence in the library dictates that the title will not be offered. Results show that titles of median commercial success are bundled more frequently than the most and least successful, and the number of similar films exiting the library is important to how likely a film is to enter, indicating strategic bundling. These results are generalizable to the streaming video industry and any information goods with rapidly diminishing marginal utility.     

A Study of the Effectiveness of Web-Based Homework in Teaching Undergraduate Business Statistics

Web-based homework (WBH) Technology can simplify the creation and grading of assignments as well as provide a feasible platform for assessment testing, but its effect on student learning in business statistics is unknown. This is particularly true of the latest software development of Web-based tutoring agents that dynamically evaluate individual students' skill level and purport to respond with appropriate, targeted teaching to improve learning efficiency. In this article, we compare traditional, textbook-based homework assignments with three systems of WBH for undergraduate business statistics courses: ALEKS, PH Grade Assist, and custom-made online quizzes in Blackboard. These systems represent a range of media from artificial intelligence–based tutoring to instructor-controlled objective testing. Using a common assessment test, we compare the performance of students taught with these different systems. Our study finds, as we anticipated, that student performance depends significantly upon teacher experience and student academic competence. Once these factors are controlled for, however, the technique used to deliver homework makes little difference in student success. In contrast to other published research, we do not find any advantage to automated tutoring and identify some limitations of this approach based on both instructor and student feedback.