What have we learned from the recent historiography of alchemy?

Over the last two decades a new scholarship on alchemy has emerged, leading to a fundamental reformulation of knowledge about alchemists and their activities. We now know that medieval and early modern alchemists employed experiment in concert with theory to demonstrate the existence of stable "chymical atoms," which were thought to combine with one another according to a hierarchical theory of matter. Employing laboratory-based analysis and synthesis, alchemists were among the first explicitly to enunciate the principle of mass balance and to show that materials are compounded of the ingredients into which they can be physically decomposed. Perhaps even more surprisingly, these convictions and practices arose out of the interaction of alchemical practice with scholastic Aristotelianism, long viewed by historians of the Scientific Revolution as antithetical to experiment. Thus the new historiography challenges both a long-standing marginalization of alchemy itself and a commonplace view of Aristotelianism as inimical to the early modern growth of experimental science.     

A study on two-layered model (Casson-Newtonian) for blood flow through an arterial stenosis: Axially variable slip velocity at the wall

The present paper sheds some light on a mathematical model for blood flow through stenosed arteries with axially variable peripheral layer thickness and variable slip at the wall. The model consists of a core region of suspension of all the erythrocytes assumed to be a Casson fluid and a peripheral layer of plasma as a Newtonian fluid. For such models, in literature, the peripheral layer thickness and slip velocity are assumed a priori based on experimental observations. In the present analysis, new analytic expressions for the thickness of the peripheral layer, slip velocity and core viscosity have been obtained in terms of measurable quantities (flow rate (Q), centerline velocity (U), pressure gradient (−dp/dz), plasma viscosity (μ_p) and yield stress (θ)). Using the experimental values of Q, U, (−dp/dz), μ_p and θ, the values of the peripheral layer thickness, core viscosity, and slip velocity at the wall have been computed. The theoretically obtained peripheral layer thickness has been compared with its experimental value. It is found that the agreement between the two is very good (error<1.4%). Further, a comparison between theoretical and experimental values of core viscosity is made and it is observed that the error between the two becomes 3.7465% in the case of two-layered model (Casson-Newtonian) for tube diameter 40 μm. The analysis developed here could be used to determine the more accurate values of the apparent viscosity of blood, agreeability, rigidity and deformability of red cells. This information of blood could be useful in the development of new diagnosis tools for many diseases.     

A validated search assessment tool: assessing practice-based learning and improvement in a residency program

Objective:

The objective of this study was to validate an assessment instrument for MEDLINE search strategies at an academic medical center.

Method:

Two approaches were used to investigate if the search assessment tool could capture performance differences in search strategy construction. First, data from an evaluation of MEDLINE searches from a pediatric resident''s longitudinal assessment were investigated. Second, a cross-section of search strategies from residents in one incoming class was compared with strategies of residents graduating a year later. MEDLINE search strategies formulated by faculty who had been identified as having search expertise were used as a gold standard comparison. Participants were presented with a clinical scenario and asked to identify the search question and conduct a MEDLINE search. Two librarians rated the blinded search strategies.

Results:

Search strategy scores were significantly higher for residents who received training than the comparison group with no training. There was no significant difference in search strategy scores between senior residents who received training and faculty experts.

Conclusion:

The results provide evidence for the validity of the instrument to evaluate MEDLINE search strategies. This assessment tool can measure improvements in information-seeking skills and provide data to fulfill Accreditation Council for Graduate Medical Education competencies.

Highlights

• The University of Michigan MEDLINE Search Assessment tool can be used to assess search skills in residency education.
• Five elements were identified as critical elements in the development of an effective MEDLINE search strategy: inclusion of all search concepts, appropriate use of Medical Subject Headings, appropriate use of search limits, successful combination of all concepts, and search efficiency.

Implications

• This validated assessment tool can serve as an effective means to measure improvements in residents'' information-seeking skills and provide data to fulfill Accreditation Council for Graduate Medical Education competencies.

     

Integrated carbon fiber electrodes within hollow polymer microneedles for transdermal electrochemical sensing

In this study, carbon fiber electrodes were incorporated within a hollow microneedle array, which was fabricated using a digital micromirror device-based stereolithography instrument. Cell proliferation on the acrylate-based polymer used in microneedle fabrication was examined with human dermal fibroblasts and neonatal human epidermal keratinocytes. Studies involving full-thickness cadaveric porcine skin and trypan blue dye demonstrated that the hollow microneedles remained intact after puncturing the outermost layer of cadaveric porcine skin. The carbon fibers underwent chemical modification in order to enable detection of hydrogen peroxide and ascorbic acid; electrochemical measurements were demonstrated using integrated electrode-hollow microneedle devices.     

An analysis of friendship networks, social connectedness, homesickness, and satisfaction levels of international students

International students continue to grow in number worldwide, prompting researchers to look for ways to make the study abroad experience more fruitful. One avenue of research has focused on friendship formation, the significant role it plays in the study abroad experience, and the unique friendship combinations made possible by the study abroad experience. International students form friendships with individuals from their own country, from other countries, and from the host country. Research has found that international students often have more friends from their home country; however, research has also demonstrated a relationship between having more host country friends and satisfaction, contentment, decreased homesickness, and social connectedness. The current study looks to further explore these relationships through a social network lens by examining friendship network ratios, strength, and variability of the three friendship groups. A friendship network grid was developed to assess where international students’ friends are from and how strong those friendships are. Eighty four international students completed a survey examining the relationship between friendship networks, social connectedness, homesickness, contentment, and satisfaction. Contrary to prior research, international students did not report having a higher ratio of individuals from their home country in their friendship networks. However, international students with a higher ratio of individuals from the host country in their network claimed to be more satisfied, content, and less homesick. Furthermore, participants who reported more friendship variability with host country individuals described themselves as more satisfied, content, and more socially connected. Implications and directions for future research are discussed.     

A comparison of anthropometric and training characteristics of Ironman triathletes and Triple Iron ultra-triathletes

We examined differences in anthropometry and training between 64 Triple Iron ultra-triathletes competing over 11.4 km swimming, 540 km cycling, and 126.6 km running, and 71 Ironman triathletes competing over 3.8 km swimming, 180 km cycling, and 42.2 km running. The association of anthropometry and training with race time was investigated using multiple linear regression analysis. The Triple Iron ultra-triathletes were smaller (P < 0.05), had shorter limbs (P < 0.05), a higher body mass index (P < 0.05), and larger limb circumferences (P < 0.01) than the Ironman triathletes. The Triple Iron ultra-triathletes trained for more hours (P < 0.01) and covered more kilometres (P < 0.01), but speed in running during training was slower compared with the Ironman triathletes (P < 0.01). For Triple Iron ultra-triathletes, percent body fat (P = 0.022), training volume per week (P < 0.0001), and weekly kilometres in both cycling (P < 0.0001) and running (P < 0.0001) were related to race time. For Ironman triathletes, percent body fat (P < 0.0001), circumference of upper arm (P = 0.006), and speed in cycling training (P = 0.012) were associated with total race time. We conclude that both Triple Iron ultra-triathletes and Ironman triathletes appeared to profit from low body fat. Triple Iron ultra-triathletes relied more on training volume in cycling and running, whereas speed in cycling training was related to race time in Ironman triathletes.     

Examining the influence of the parent-initiated and coach-created motivational climates upon athletes' perfectionistic cognitions

The aims of this study are threefold. First, we investigate the influence of the parent-initiated motivational climate upon elite junior athletes' perfectionistic cognitions. Second, we examine whether the coach-created motivational climate predicts additional variance in elite junior athletes' perfectionistic cognitions beyond the effects associated with the parent-initiated motivational climate. Third, we test the moderating role of athletes' gender and age in the relationship between the parent-initiated and coach-created motivational climates and athletes' perfectionistic cognitions. A total of 190 elite junior athletes (mean age 15.2 years, s?=?1.5, range 10-18) completed the Parent-Initiated Motivational Climate Questionnaire-2 (White & Duda, 1993), the Perceived Motivational Climate in Sport Questionnaire-2 (Newton, Duda, & Yin, 2000), and the Perfectionistic Cognitions Inventory (Flett, Hewitt, Blankstein, & Gray, 1998). Regression analyses revealed that mother- and father-initiated worry-conducive climates, the father-initiated success-without-effort climate, and the coach-created performance motivational climate predicted male athletes' perfectionistic cognitions. Female athletes' perfectionistic cognitions were predicted by the mother-initiated worry-conducive climate, father-initiated learning-enjoyment climate, and both dimensions of the coach-created climate. Finally, athletes' gender emerged as a significant moderator of the mother-initiated worry-conducive climate and athletes' perfectionistic cognitions relationship. Findings confirm that the parent-initiated motivational climate is a significant predictor of athletes' perfectionism-related thoughts, and provide initial support for the influence of the coach-created motivation climate over children's perfectionistic cognitions.     

Attentional bias for exercise-related images

This research examined attentional bias toward exercise-related images using a visual probe task. It was hypothesized that more-active participants would display attentional bias toward the exercise-related images. The results showed that men displayed attentional bias for the exercise images. There was a significant interaction of activity level by gender, and simple slopes analysis showed that active women displayed attentional bias toward the exercise-related images and inactive women displayed attentional bias toward the control images. A similar analysis with explicit attention to the pictures as the outcome variable was not significant. These findings confirm that attention for exercise-related images can be captured automatically regardless of whether people report they are attending to them.     

Coaching competency and satisfaction with the coach: a multi-level structural equation model

The purpose of this initial predictive validity study was to determine the ability of measures derived from the Athletes' Perceptions of Coaching Competency Scale II?-?High School Teams (APCCS II-HST) to predict satisfaction with the head coach. Specification of the statistical model was informed by the mediational model of coach-athlete interactions. The technical quality of the satisfaction measure was evaluated before testing the predictive validity of the coaching competency measures. Data were collected from athletes of seven sports. Athlete observations (N?=?748) were clustered within teams (G?=?74). Multi-group confirmatory factor analyses (CFA) provided evidence for factorial invariance of a reduced version of the satisfaction measure by athlete gender. Multi-level CFA provided evidence of model-data consistency for a reduced version of the satisfaction measure. Multi-level structural equation modelling provided evidence for the ability of latent coaching competency to positively predict latent satisfaction at both the athlete level (technique competency and motivation competency) and the team level (coaching competency) and for close model-data fit. Implications of this study include: that the APCCS II-HST should be viewed as a replacement for the Coaching Competency Scale when the intended population is appropriate; a preliminary multi-level measurement model for satisfaction with one's coach that should be considered as a potential starting point in subsequent studies; and empirical support for a key relationship proposed in the mediational model of coach-athlete interactions.     

Identifying the Content,Lesson Structure,and Data Use Within Pre-collegiate Data Science Curricula

Journal of Science Education and Technology - As data become more available and integrated into daily life, there has been growing interest in developing data science curricula for youth in...