Exploring in vitro gastrointestinal digestion of myofibrillar proteins at different heating temperatures.

The effects of different heating temperatures (40-115 °C) on the structure, oxidation, and digestibility of beef myofibrillar protein were investigated. Reductions in the number of sulfhydryl groups were observed, together with gradual increases in the number of carbonyl groups, indicating oxidation of the protein by the increased temperatures. At temperatures between 40 °C and 85 °C, ß-sheets were converted to α-helices, and increased surface hydrophobicity showed that the protein expanded as the temperature approached 85 °C. These changes were reversed at temperatures over 85 °C, indicative of aggregation induced by thermal oxidation. Between 40 °C and 85 °C, the digestibility of the myofibrillar protein was increased, reaching a maximum of 59.5 % at 85 °C, after which it began to decrease. These results indicated that moderate heating and oxidation-induced protein expansion were beneficial to digestion while protein aggregation resulting from excessive heating is not conducive to digestion.

An Investigation Into the Impact of Test Session Disruptions for At-Home Test Administrations.

In response to the closures of test centers worldwide due to the COVID-19 pandemic, several testing programs offered large-scale standardized assessments to examinees remotely. However, due to the varying quality of the performance of personal devices and internet connections, more at-home examinees likely suffered "disruptions" or an interruption in the connectivity to their testing session compared to typical test-center administrations. Disruptions have the potential to adversely affect examinees and lead to fairness or validity issues. The goal of this study was to investigate the extent to which disruptions impacted performance of at-home examinees using data from a large-scale admissions test. Specifically, the study involved comparing the average test scores of the disrupted examinees with those of the non-disrupted examinees after weighting the non-disrupted examinees to resemble the disrupted examinees along baseline characteristics. The results show that disruptions had a small negative impact on test scores on average. However, there was little difference in performance between the disrupted and non-disrupted examinees after removing records of the disrupted examinees who were unable to complete the test.

How Do Test Takers Interact With Simulation-Based Tasks? A Response-Time Perspective.

Many traditional educational assessments use multiple-choice items and constructed-response items to measure fundamental skills. Virtual performance assessments, such as game- or simulation-based assessments, are designed recently in the field of educational measurement to measure more integrated skills through the test takers' interactive behaviors within an assessment in a virtual environment. This paper presents a systematic timing study based on data collected from a simulation-based task designed recently at Educational Testing Service. The study is intended to understand the response times in complex simulation-based tasks so as to shed light on possible ways of leveraging response time information in designing, assembling, and scoring of simulation-based tasks. To achieve this objective, a series of five analyses were conducted to first understand the statistical properties of the timing data, and then investigate the relationship between the timing patterns and the test takers' performance on the items/task, demographics, motivation level, personality, and test-taking behaviors through use of different statistical approaches. We found that the five analyses complemented each other and revealed different useful timing aspects of this test-taker sample's behavioral features in the simulation-based task. The findings were also compared with notable existing results in the literature related to timing data.

Characterizing Interactive Communications in Computer-Supported Collaborative Problem-Solving Tasks: A Conditional Transition Profile Approach.

Communication in a collaborative problem-solving activity plays a pivotal role in the success of the collaboration in both academia and the workplace. Computer-supported collaboration makes it possible to collect large-scale communication data to investigate the process at a finer granularity. In this paper, we introduce a conditional transition profile (CTP) to characterize aspects of each team member's communication. Based on the data from a large-scale empirical study, we found that participants in the same team tend to show similar CTP compared to participants from different teams. We also found that team members who showed more "negotiation" after the partner "shared" information tended to show more improvement after the collaboration while those who continued sharing ideas while their partners were negotiating tended to improve less.