Extended Testing Time Research Articles

Mammalian Cell Culture on a Novel Chitosan‐Based Biomaterial Crosslinked with Gluteraldehyde

AbstractA novel (Chitosan‐g‐Glycidyl Methacrylate)‐Xanthan, (CTS‐g‐GMA)‐X, hydrogel was successfully synthesized at Cinvestav Queretaro. In the present work, we attempt to study the in vitro biocompatibility of (CTS‐g‐GMA)‐X hydrogels as scaffolds for neural cells obtained from cerebral cortex of mice; skin cells from skin of mice; and chondrocytes from human cartilage. The results obtained in the live/dead assay show that the materials maintain the morphology and viability of the cells. However the high friability of the materials prevented an extended test time in this assay. Therefore, glutaraldehyde (GL) was added to the structure as crosslinking agent to enhance friability. All results point out that [(CTS‐g‐GMA)‐X]‐GL hydrogel is viable as a scaffold for chondrocytes and skin cells; and (CTS‐g‐GMA)‐X for neural cell due to their physicochemical properties and biocompatibility with the cells for both materials.

Math, Science, and Foreign Language: Evidence‐Based Accommodation Decision Making at the Postsecondary Level

Accommodations in postsecondary settings have become commonplace for many students with learning disabilities (LD) who have documented needs. Many of the accommodations professionals recommend for students with LD are based on an analysis of the course demands, the student's functional limitations, and a basic understanding of how the accommodation can facilitate the demonstration or acquisition of knowledge. However, little is known about which accommodations are recommended for math, science, and foreign language courses as well as the effectiveness of those accommodations. Because these content areas pose substantial hurdles for secondary students with LD who may transition to postsecondary settings, a review of the literature was conducted to evaluate current practices in the provision of accommodations to postsecondary students with LD in math, science, and foreign language courses. Findings indicate strong empirical evidence for extended test time for algebra exams and emerging research in changes to foreign language instruction. Recommendations for further research are provided.

Using Speeded Cognitive, Reading, and Academic Measures to Determine the Need for Extended Test Time among University Students with Learning Disabilities

This study examined the relationship between scores on “speeded” cognitive and academic tests and the need for the accommodation of extended test time for normally achieving students (NA) and students with learning disabilities (LD). Often, in postsecondary settings the decision to provide the accommodation of extended test time is based largely on the diagnostic test scores in the student's LD documentation. Therefore, the primary purpose of this study was to evaluate the relationship between specific diagnostic tests and the need for the accommodation of extended test time. A secondary purpose was to investigate the relationships and predictive ability of five speeded cognitive tests, three speeded cluster scores, and two measures of timed reading. Correlations and logistic regression analyses were used to assess gain in score performance and predict the need for extended test time. Participants included 41 NA university students and 43 university students with LD. The findings indicated significant group differences on all speeded cognitive, reading, and academic tests, with the exception of Digit Symbol on the Wechsler Adult Intelligence Scale-III and Retrieval Fluency and Decision Speed tests on the Woodcock-Johnson III Tests of Cognitive Abilities. The Reading Fluency test and the Academic Fluency cluster of the Woodcock-Johnson Tests of Achievement III were the best predictors of students with LD who needed extended time on the multiple-choice reading comprehension test.

A STUDY OF FATIGUE EFFECTS FROM THE NEW SAT®

ABSTRACTThis study evaluated whether the addition of a writing section to the SAT Reasoning Test™ (referred to as the SAT® in this study) would impact test‐taker performance because of fatigue caused by increased test length. The study also investigated test‐takers' subjective feelings of fatigue. Ninety‐seven test‐takers were randomly assigned to three groups: the first group took a current SAT with no essay; the second group took a pseudo new SAT composed of the current SAT plus an essay, with the essay appearing in the first section of the test; and the third group also took the pseudo new SAT with an essay, but with the essay in the last section. Test‐taker performance on the verbal and math sections and the essay was then evaluated and compared. The results indicated that while the extended testing time for the new SAT may cause test‐takers to feel fatigued, fatigue did not affect test‐taker performance.

Extended Test Time and postsecondary Students with Learning Disabilities: A Model for Decision Making

The most frequently requested accommodation among students with learning disabilities (LD) in postsecondary settings is extended test time. The frequency with which this accommodation is requested and granted compels disability service providers to become knowledgeable about the factors that influence the need for, and appropriateness of, the accommodation. Moreover, the synthesis of these factors becomes the basis for determining if the accommodation is reasonable under federal law. The purpose of this article is to present a step‐by‐step model to be used as a decision‐making process when considering the accommodation of extended test time for postsecondary students with LD. The model is designed to assist disability service providers in the analysis and synthesis of information collected from (1) the student's diagnostic evaluation, (2) the course or classroom test to be accommodated, and (3) student interviews. A list of diagnostic tests from the four most frequently administered test batteries used with adults is provided, along with a concise explanation of how characteristics of LD impact reading, writing, and math, and relate to the need for extended time. This information can be used to determine if extended test time is a reasonable accommodation and to estimate how much additional time to provide.

Effect of cycle frequency on high-temperature oxidation behavior of alumina-forming alloys

Cycle frequency affects both high-temperature oxidation behavior and the method in which the cyclic test is conducted. Several issues are discussed using examples taken from results for Ni-base and Fe-base, alumina-forming alloys. For alloys that form adherent scales, cycle frequency has little effect on results over extended test times ( ≥500 hr). When an alloy forms a less adherent scale, reducing the cycle time often has the expected effect of increasing the mass loss per unit exposure time; however, the opposite effect is observed in other cases. Low-frequency cycle experiments can be conducted with specimens contained in alumina crucibles. This has the important benefit of collecting the spalled oxide and measuring the “total” mass gain, equivalent to the metal wastage. However, higher-frequency-cyclic tests cannot be performed with crucibles because of the large thermal mass and thermal-shock problems of alumina crucibles. The test method and cycle frequency ultimately have a strong effect on lifetime predictions.

Long‐term habituation of the speech‐elicited mismatch negativity

A significant issue in the use of the mismatch negativity evoked potential (MMN) concerns its low signal-to-noise ratio (SNR). One can improve the noise level by increasing the number of samples included in the averaged response. However, improvement achieved in this way assumes that the signal, the MMN, remains stable for extended test times, an assumption which has not been tested. If the MMN is not stable, or exhibits habituation over the test session, then SNR would be adversely affected. MMN response magnitude was measured in 5-min intervals over the course of a test session in response to various speech syllable contrasts. Significant long-term habituation of MMN was observed for all three subject populations tested: young adults, school-age children, and guinea pigs. The time course of the habituation and the stimulus conditions under which it occurs have important implications for research and clinical applications of the MMN. Recording procedures that minimize habituation effects may be used to advantage to improve the signal-to-noise ratio of the MMN.

Effect of testing conditions on the laser flash thermal diffusivity measurements of ceramics

Several experimental techniques either under steady state or transient heat transfer conditions, have been developed to evaluate thermal conductivity and thermal diffusivity of materials. However, testing difficulties resulting from specimen size, extended testing time and heat losses, have somewhat impaired the applicability of many of them. In this respect, the use of the laser flash technique for thermal diffusivity measurements, is a very convenient alternative, considering its basic modeling equation is independent of the temperature gradient as well as the heat flow, and in addition the heat losses can be analytically treated. Another important advantage of the technique is its rapid experimental execution. In this work, it is presented as an investigation concerning how the testing conditions such as specimen coating, laser power and pulse duration, base line adoption, heat losses correction methods, and specimen thickness, may affect the thermal diffusivity measurements of some ceramic materials using the laser flash technique.

The influence of crank rate on peak oxygen consumption during arm crank ergometry

The aim of this study was to assess the influence of three imposed crank rates on the attainment of peak oxygen consumption ( V O 2peak ) and other physiological responses during incremental arm crank ergometry. Twenty physically active, although non-specifically trained, males volunteered for the study. They completed an exercise protocol using an electrically braked arm ergometer (Lode Angio, Groningen, Netherlands) at crank rates of 60, 70 and 80 rev·min -1 . The order of tests was randomized and they were separated by at least 2 days. Peak V O 2 was significantly higher ( P ≪ 0.05) at 70 and 80 rev·min -1 than at 60 rev·min -1 . Peak ventilation volume increased as a function of crank rate and was higher ( P ≪ 0.05) at 80 than at 60 rev·min -1 . Peak heart rate was higher ( P ≪ 0.05) at 70 and 80 rev·min -1 than at 60 rev·min -1 . Furthermore, 70 and 80 rev·min -1 resulted in an extended test time compared with 60 rev·min -1 . The greater physiological responses observed during the tests at the two faster crank rates might have been the result of a postponement of acute localized neuromuscular fatigue, allowing for more work to be completed. We recommend, therefore, that an imposed crank rate between 70 and 80 rev·min -1 should be used to elicit V O 2peak and other physiological responses in arm crank ergometry.

Relationship between stator core buckling, core losses, vibration and local over-temperatures

Measurements on a hydrogenerator stator core during core test with higher-than-normal magnetic flux and extended test time provided the base for a study of interaction between buckling, local heat generation, hot spots, and vibration. The mechanism of buckling is analyzed. Curves were developed showing how the buckling influences the temperature at the bottom of the slot and between the stator coils. There is clear evidence that the core does not behave as a homogeneous structure. The upper and lower halves of the core may vibrate independently of each other, with different node numbers. The node number may be an odd number, contrary to the accepted theory. The magnitude and position of buckling does not seem to have any influence on the distribution of vibration nodes.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>