Gastric Emptying Characteristics of Glucose and Glucose Polymer Solutions

Abstract

In an effort to evaluate various carbohydrate (CHO) molecules for inclusion in an athletic drink, the gastric emptying characteristics of 5, 10, 20, and 40% solutions of glucose and a glucose polymer were compared. The volume of gastric residue remaining 30 minutes after ingestion of 400 ml of each of the solutions was determined in 15 healthy individuals. The volume of gastric residue recovered increased progressively with increasing solute concentration. At the lowest CHO concentration the glucose polymer yielded a significantly smaller gastric residue than glucose. The smaller residue appeared to be attributable both to a greater rate of exit of the polymer from the stomach as well as to a lower rate of gastric secretion induced by the polymer. The calculated delivery of CHO to the intestine increased with solute concentration. At the lowest CHO concentration the more rapid gastric emptying of the polymer allowed significantly greater calculated CHO delivery. We conclude that at low CHO concentrations (≤5 g/100 ml), such as used in drinks designed for athletics participants, the glucose polymer might be an advantageous alternative to glucose as a source of CHO.     

Increasing Student Success Using Online Quizzing in Introductory (Majors) Biology

Students often complain about their perceived disconnect between the time and effort spent studying and their subsequent performance on exams. Robert Bjork''s research asserts that retrieval of stored information acts as a memory modifier, and that using tests as learning events creates “desirable difficulties that enhance learning.” To determine the effect of utilizing testing as a learning event in the introductory (majors) biology classroom, we used an online homework platform to give required quizzes throughout the course. Analysis of exam grades earned by those taking 100% of pre-exam quizzes indicates that not only does this group have a significantly higher exam average than the group of students who took 0% of the pre-exam quizzes, but they also have a significantly higher exam average than the class average. Through detailed, statistical analysis, the benefit of quizzing is demonstrated to be significant for students of diverse academic abilities. Pre-exam quizzing using an online homework platform is an effective way to increase student performance on exams and allows class time to be utilized for teaching activities.     

Cataloging in a Remote Location: A Case Study of International Collaboration in the Galapagos Islands

The Corley Smith Library is a small, special library located at the Charles Darwin Research Station in the Galapagos Islands. Currently, the library is managed by international volunteer librarians in collaboration with Station staff and local volunteers. Recently the library migrated its online public access catalog to Koha. We describe the process of selecting an open-source integrated library system and implementing Koha. Cataloging in this remote location presents challenges related to technology, staff expertise, language, local practices, and obtaining supplies. We define the strategies to address these issues, including long-term goals of copy cataloging with Z39.50 and remote cataloging by volunteer librarians.     

User dyads in software testing: bypassing the need for expert observers

This paper arises out of a research study into the online help facilities provided in popular software applications such as word processors. Its particular focus is on experimental methods of evaluating the effectiveness and usability of those facilities. Focus groups, questionnaires, and online surveys had already been used in other phases of the study, but it was judged that these approaches would be unsuitable for measuring effectiveness and usability because they are susceptible to respondents’ subjectivity. Direct observation of people working on set word‐processing tasks was ruled out initially because of a lack of trained observers; it would have taken too long for the investigator to observe a large enough sample by himself. Automatic recording of users’ actions was also rejected, as it would have demanded equipment and/or software that was not available and seemed too expensive to acquire. The approach and techniques described here were an attempt to overcome these difficulties by using observers drawn from the same population of students that provided the test subjects; as a by‐product, this may also have enhanced the acceptability (and hence possibly the validity) of the experiments by reducing the “exam pressure” perceived by participants.