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

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.     

Physical activity profiles and selected muscular fitness variables in English schoolchildren: A north–south divide?

The aim of the study was to compare and contrast habitual physical activity (PA) profiles and muscular fitness in schoolchildren from northern and southern regions of England. Data were collected from two secondary schools in the north east (NE) of England. The study procedures followed methods employed by the East of England Healthy Hearts Study in 10–16-year-old boys and girls based in the south east (SE) region of England and data were compared. Habitual physical activity (PAQ-A), vertical jump test, and hand-grip (HG) strength were assessed. We converted raw scores from all assessments to age- and sex-normalised z-scores. We recruited 597 children (58% boys) in the NE and compared findings to 597 age- and sex-matched boys and girls from the SE. Boys in the SE had significantly stronger HG scores, jumped higher, were more powerful (mean peak power: 2131?W vs. 1782?W; P?P?P?相似文献   

Influence of sex and limb dominance on lower extremity joint mechanics during unilateral land-and-cut manoeuvres

Limb dominance theory suggests that females tend to be more one-leg dominant and exhibit greater kinematic and kinetic leg asymmetries than their male counterparts, contributing to the increased risk of anterior cruciate ligament injury among female athletes. Thus, the purpose of this study was to examine the influences of sex and limb dominance on lower extremity joint mechanics during unilateral land-and-cut manoeuvres. Twenty-one women and 21 men completed land-and-cut manoeuvres on their dominant limb as well as their nondominant limb. Three-dimensional kinematics and kinetics were calculated bilaterally for the entire stance phase of the manoeuvre. Women performed land-and-cut manoeuvres with altered hip motions and loads as well as greater knee abduction at touchdown compared to men. Dominant limb land-and-cut manoeuvres where characterised by decreased hip flexion at touchdown as well as decreased hip flexion and adduction range of motion compared to nondominant land-and-cuts regardless of sex. The observed sex differences are consistent with previous research regarding mechanisms underlying the sex disparity in anterior cruciate ligament injury rates. However, observed differences regarding limb dominances appear somewhat arbitrary and did not suggest that the dominant or nondominant limb would be at increased risk of anterior cruciate ligament injury.     

Melding ‘High Tech’ and ‘High Touch’: a Communications Curriculum for the New Information Society

Abstract

The article looks at the organization and work of Computer Pals Across the World, and the views on its future by its American President and Australian National Director. It looks briefly at some projects and at some future projects all of which will be of interest to educational technologists. Further information can be obtained from the CPAW Virtual Secretariat ‐ dboehm@onr.com on the Internet

Abstract français: Le sujet de cet article est 1'organisation et la fonction de ‘Computer Pals Across the World’ et il présent les idées de son President Americain et son Directeur National Australian. Il considère en resumé quelques projets d'avenir qui seront très intréssants pour les technologistes éducatives. On peut obtenir d'autres renseignements du CPAW Virtual Secretariat ‐ sur l'Internet     

Hands-On: Investigating the role of physical manipulatives in spatial training

Studies show that spatial interventions lead to improvements in mathematics. However, outcomes vary based on whether physical manipulatives (embodied action) are used during training. This study compares the effects of embodied and non-embodied spatial interventions on spatial and mathematics outcomes. The study has a randomized, controlled, pre-post, follow-up, training design (N = 182; mean age 8 years; 49% female; 83.5% White). We show that both embodied and non-embodied spatial training approaches improve spatial skills compared to control. However, we conclude that embodied spatial training using physical manipulatives leads to larger, more consistent gains in mathematics and greater depth of spatial processing than non-embodied training. These findings highlight the potential of spatial activities, particularly those that use physical materials, for improving children's mathematics skills.     

Everything is illuminated: What big data can tell us about teacher commentary

What happens to writing instructors’ feedback when they use a common rubric and an online tool to respond to student papers in a first-year composition course at a large state university in the United States? To investigate this question, we analyze the 118,611 comments instructors made when responding to 17,433 student essays. Using concordance software to quantify teachers’ use of rubric terms, we found instructors were primarily concerned with global, substantive, higher-order concerns—such as responding to students’ rhetorical situations, use of reason, and organization—rather than lower-order concerns about grammar or formatting. Given past research has determined teachers overemphasize lower-order concerns such as grammar, mechanics, and punctuation (Connors and Lunsford, 1988, Lunsford and Lunsford, 2008, Moxley and Joseph, 1989, Moxley and Joseph, 1992, Schwartz, 1984, Sommers, 1982, Stern and Solomon, 2006), these results may suggest the possibility of a generational shift when it comes to response to student writing. Aggregating teacher commentary, student work, and peer review responses via digital tools and employing concordance software to identify big-data patterns illuminates a new assessment practice for Writing Program Administrators—the practice of Deep Assessment.