Comparison of oil and egg tempera paint systems using time-of-flight secondary ion mass spectrometry     

Zachary E. Voras  Kristin deGhetaldi  Brian Baade  Eric Gordon  Glenn Gates  Thomas P. Beebe 《文物保护研究》2016,61(4):222-235

Time-of-flight secondary ion mass spectrometry (ToF-SIMS) is quickly becoming a critical tool in the field of art conservation. This technique provides high-resolution spatial maps of both inorganic and organic components located within cross-sectional samples collected from works of art. With recent advances in surface analysis, ToF-SIMS can now be used to identify specific amino acids present in protein-containing materials as well as fatty acids in drying oils. For example, the detection of the ion fragment associated with the amino acid hydroxyproline can be used to confirm the use of animal glue in a paint sample. As an analytical technique, ToF-SIMS avoids the need for derivatization/silylation reagents, with no interference by the presence of pigments. Furthermore, the layered systems that are often encountered in historical paint samples remain intact throughout the analytical procedure. This allows for the co-localization of organic and inorganic species in specific layers (e.g. egg yolk paint atop a glue ground). Because of this ability to localize the analytical signal to approximately 6?µm or less, the mass spectral information can be used to produce mass-resolved and spatially-resolve images which can be correlated to previous studies of the same samples. In this study, ToF-SIMS was used to analyze a paint cross section obtained from a painting attributed to Raphael, and another from a painting by the Sienese artist Matteo di Giovanni.  相似文献   

The effects of physical contact type on the internal and external demands during a rugby league match simulation protocol     

Jonathan P. Norris  Jamie Highton  Stephen F. Hughes  Craig Twist 《Journal of sports sciences》2016,34(19):1859-1866

The aim of this study was to investigate how the type of contact influences physiological, perceptual and locomotive load during a simulated rugby league match. Eleven male university rugby league players performed two trials of the rugby league movement simulation protocol for interchange forwards with a traditional soft tackle bag and a weighted tackle sled to replicate contact demands. The interchange forward-specific simulation was chosen given the contact frequency is higher for this group of players compared to whole match players. Locomotive rate, sprint speed, tackle intensity, heart rate (HR) and rating of perceived exertion were analysed during the first and second bouts that replicated two ~23 min on-field passages. Countermovement jump (CMJ) was measured before and immediately after each trial. More time was spent in heart rate zone between 91 and 100% HR_peak during the first (effect size ± 90% confidence interval: 0.44 ± 0.49) and second bouts (0.44 ± 0.43), and larger (0.6 ± 0.69) decrements in CMJ performance were observed during the sled trial (5.9, s = 4.9%) compared to the bag trial (2.6, s = 5.4%). Changing the type of contact during the match simulation subtly altered both the internal and external loads on participants. Using a standard tackle bag results in faster sprint speed to contact, but lower overall high-intensity running. Conversely, a heavier tackle object increases the internal load and results in greater lower limb neuromuscular fatigue as reflected by the decrease in CMJ performance.  相似文献   

Visually Framing Press Freedom and Responsibility of a Massacre: Photographic and Graphic Images in Charlie Hebdo's Newspaper Front Pages Around the World     

Kristin L. Gustafson  Linda Jean Kenix 《Visual Communication Quarterly》2016,23(3):147-160

This research examines 441 front-page images published in 367 newspapers on the day following the shooting in Paris of 12 people at or near the Charlie Hebdo office. The aim of this study is to understand how mainstream media visually framed responsibility for the Charlie Hebdo massacre and how these visual frames coalesced to represent collective narratives about press freedom. Through a collaborative visual analysis, this study attempts to understand how the selected visual frames worked to communicate the causes, effects, and responses to the massacre and also to press freedom—an ideological construct that news media had a vested interest in advancing.  相似文献   

Mapping Survey Data to the Mission and Strategic Plan: You Won't Believe What Happened Next!          下载免费PDF全文

Judith A. Ouimet  Kristin A. Hobson  Dennis P. Groth 《Assessment Update》2016,28(5):5-11

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No Child Left Behind: Implications for college student learning     

Teniell L. Trolian  Kristin S. Fouts 《About Campus》2011,16(3):2-7

What does No Child Left Behind (NCLB) have to do with higher education? Turns out plenty, according to Teniell L. Trolian and Kristin S. Fouts. They argue that NCLB has signifcant consequences for college learners.  相似文献   

Analysis of self-regulated learning processing using statistical models for count data     

Jeffrey Alan Greene  Lara-Jeane Costa  Kristin Dellinger 《Metacognition and Learning》2011,6(3):275-301

Researchers often use measures of the frequency of self-regulated learning (SRL; Zimmerman, American Educational Research Journal, 45(1), 166–183, 2000) processing as a predictor of learning gains. These frequency data, which are really counts of SRL processing events, are often non-normally distributed, and the accurate analysis of these data requires the use of specialized statistical models. In this study, we demonstrate how to implement and interpret count statistical models in path and latent profile analyses to investigate the role of SRL as a mediator of the relation between pretest and posttest conceptual understanding. Our findings from a sample of 170 college students using a computer to learn about the circulatory system show that SRL does mediate the aforementioned relation, and that count models are a more accurate representation of SRL processing data than standard analysis models based on ordinary least squares estimation. The results of our path analyses revealed which specific SRL processes were related to learning, above and beyond the effect of prior knowledge. Our latent profile analysis revealed two groups of participants, indicative of Brophy’s (2004) model of schematic and aschematic learners. We conclude with implications and future directions for basic and applied SRL research.  相似文献   

How Prepared Are MSW Graduates for Doctoral Research? Views of PhD Research Faculty     

James W. Drisko  Kristin Evans 《Journal of Teaching in Social Work》2018,38(2):198-213

ABSTRACT

This national survey of PhD faculty assessed the research preparation of entering doctoral social work students on a wide range of research knowledge and related skills. The prior literature shows that PhD programs repeat much BSW and MSW research course content. This study shows that the trend continues and has perhaps widened. PhD research faculty report that the typical entering PhD student displayed solid conceptual, ethics, and writing skills but lesser preparation for conducting quantitative and qualitative research, including methods related to understanding evidence-based practice. The research expectations of responding PhD faculty were low, reflecting limited retention and little production of research among typical entering doctoral students. These findings raise the issue of how effectively the social work profession prepares students for research and for future PhD education.  相似文献   

Student formation in higher education: teachers’ approaches matter     

Tone Dyrdal Solbrekke  Kristin Helstad 《Teaching in Higher Education》2016,21(8):962-977

Teaching in higher education encompasses more than merely helping students develop knowledge and skills. It entails engaging students in their own formation as persons, professionals and citizens. From this perspective, this article investigates how approaches to teaching academic writing contribute to formation. By analysing a case from initial teacher education in Norway, we identify and examine one teacher educator’s beliefs about writing and his approaches to teaching writing. Theoretical framework rests on six discourses of writing developed by Roz Ivani? and on the formative possibilities and constraints embedded in these different literacy discourses. Thus, we provide students’ experien-ces with this teacher’s approaches and discuss what formation his approaches seem to have initiated. The findings point to the need for more critical reflection on the formative impact of teaching approaches in higher education more generally.  相似文献   

Device Comparability of Tablets and Computers for Assessment Purposes     

Laurie Laughlin Davis  Xiaojing Kong  Yuanyuan McBride  Kristin M. Morrison 《教育实用测度》2017,30(1):16-26

The definition of what it means to take a test online continues to evolve with the inclusion of a broader range of item types and a wide array of devices used by students to access test content. To assure the validity and reliability of test scores for all students, device comparability research should be conducted to evaluate the impact of testing device on student test performance. The current study looked at the comparability of test scores across tablets and computers for high school students in three commonly assessed content areas and for a variety of different item types. Results indicate no statistically significant differences across device type for any content area or item type. Student survey results suggest that students may have a preference for taking tests on devices with which they have more experience, but that even limited exposure to tablets in this study increased positive responses for testing on tablets.  相似文献   

Thinking about the future because of the past: young children's knowledge about the causes of worry and preventative decisions   总被引：1，自引：1，他引：0  

Lagattuta KH 《Child development》2007,78(5):1492-1509

Two studies investigated 3- to 6-year-olds' and adults' (N= 128) knowledge about emotions and behaviors caused by thinking about the future because of the past. Participants listened to stories featuring characters that experienced negative events, and then, many days later, felt worried or changed their behaviors upon seeing an entity associated with the prior harm. Results revealed a significant increase between 3 and 5 years in the frequency that participants explained characters' reactions as caused by anticipating the reoccurrence of a negative past event. Across age, females more often marked future events as uncertain, as well as predicted that people in ambiguous risk situations would feel worried due to past-to-future connections.  相似文献