Lead soaps in paintings: Friends or foes?     

Marine Cotte  Emilie Checroun  Wout De Nolf  Yoko Taniguchi  Laurence De Viguerie  Manfred Burghammer 《文物保护研究》2017,62(1):2-23

The origin(s) and role(s) of metal soaps in paints are a worldwide concern today. These hybrid compounds, containing both fatty acid chains and metals associated with a carboxylate function, are increasingly identified in paints. As reviewed in the first part of this work, the presence of metal soaps in paints is differently interpreted in scientific publications: metal soaps are sometimes considered to play a positive role as anchor points, during paint drying processes; they can also be considered as responsible for many degradation processes (protrusions, efflorescences, darkening, etc.). Their origins are also interpreted in various ways. In some paintings (in particular from the twentieth century), they have sometimes introduced on purpose, as additives, to modify the physical properties of the painting materials. In older paintings, metal soaps are usually thought to result from an uncontrolled reaction of oil with lead-based pigments, in particular lead white, red lead, and lead tin yellow. In the second part of this work, the review of historical recipes of lead-based paint shows an important number of recipes based on controlled mixing of oil with lead driers. In the third part, the experimental reproduction of such traditional recipes using walnut oil and litharge (PbO) shows that lead soaps can be formed, both in about one hour at ～100°C, or in about one month at room temperature. It shows as well that after a few years, litharge is no longer detected in the paint medium, while different lead carbonates are. Finally, the micro-infrared spectroscopy and micro-X-ray diffraction re-analysis of protrusions from a nine-year model painting shows together with lead soaps, the presence of Pb₅(CO₃)₃(OH)₂O (‘synthetic plumbonacrite’), an unusual phase recently observed in a protrusion from a painting by Vincent Van Gogh. This work highlights (i) the multiple origins and roles of metal soaps in paints and (ii) the importance of combining the analysis of fragments from historical paintings with the analysis and reproduction of historical recipes. In particular, we show that the components detected today in historical paintings may severely differ from those originally used or prepared by the painter, complicating the assessment of the painter's intentions. More than the presence of metal soaps, the key questions to be tackled should be about their origins and (re)mobilization.  相似文献   

A comparison of types of attorney representation for children in California juvenile court dependency cases     

Goodman GS  Edelstein RS  Mitchell EB  Myers JE 《Child abuse & neglect》2008,32(4):497-501

OBJECTIVE: The present study concerns types of attorney representation for maltreated children involved in juvenile court actions in the state of California. The aims of the research were to document the different types of representation used in dependency cases in 2000 (e.g., public defender, District Attorney, private firms) and to evaluate these types of representation with respect to children's experiences in foster care. METHODS: Every county in California was surveyed about the predominant type of legal representation used in their dependency court system. In addition, data on children's experiences in foster care were obtained from the Child Welfare System/Child Management System (CWS/CMS). RESULTS: Findings indicate that, in the majority of counties in California, children were represented by the public defender's office or by a panel of court-appointed attorneys. Approximately equal numbers of counties employed county-affiliated (i.e., District Attorney, public defender, county counsel) and independent (i.e., private firm, panel of court-appointed attorneys) types of representation (47% and 52%, respectively). Further analyses suggested that children in counties employing independent types of representation tended to experience fewer foster-care placements than did children in counties employing county-affiliated types of representation. This relation remained significant when potentially confounding variables were statistically controlled. CONCLUSION: Results indicated that some types of representation, specifically, private firms and court-appointed attorneys, were associated with one better outcome for children.  相似文献   

Developing a System of Program Assessment Within Teacher Education: Lessons Learned     

Kara Mitchell Viesca  Emilie Mitescu Reagan  Sarah Enterline  Ann Marie Gleeson 《The Teacher Educator》2013,48(4):257-275

Our intention in this article is to present one institution's efforts to take on program assessment and respond to calls for accountability. To do so, the teacher education program simultaneously sought to address the narrowly defined measures called for by policy makers and politicians, while at the same time broadening and expanding outcomes (such as student learning) and the missions, themes, and values of the teacher education program. The following describes the accountability movement in teacher education and then offers the lessons learned within one program developing a system of assessment within teacher education.  相似文献   

Microfluidic device for generating a stepwise concentration gradient on a microwell slide for cell analysis     

Emilie Weibull  Shunsuke Matsui  Manabu Sakai  Helene Andersson Svahn  Toshiro Ohashi 《Biomicrofluidics》2013,7(6)

Understanding biomolecular gradients and their role in biological processes is essential for fully comprehending the underlying mechanisms of cells in living tissue. Conventional in vitro gradient-generating methods are unpredictable and difficult to characterize, owing to temporal and spatial fluctuations. The field of microfluidics enables complex user-defined gradients to be generated based on a detailed understanding of fluidic behavior at the μm-scale. By using microfluidic gradients created by flow, it is possible to develop rapid and dynamic stepwise concentration gradients. However, cells exposed to stepwise gradients can be perturbed by signals from neighboring cells exposed to another concentration. Hence, there is a need for a device that generates a stepwise gradient at discrete and isolated locations. Here, we present a microfluidic device for generating a stepwise concentration gradient, which utilizes a microwell slide''s pre-defined compartmentalized structure to physically separate different reagent concentrations. The gradient was generated due to flow resistance in the microchannel configuration of the device, which was designed using hydraulic analogy and theoretically verified by computational fluidic dynamics simulations. The device had two reagent channels and two dilutant channels, leading to eight chambers, each containing 4 microwells. A dose-dependency assay was performed using bovine aortic endothelial cells treated with saponin. High reproducibility between experiments was confirmed by evaluating the number of living cells in a live-dead assay. Our device generates a fully mixed fluid profile using a simple microchannel configuration and could be used in various gradient studies, e.g., screening for cytostatics or antibiotics.  相似文献   

Social play as joint action: A framework to study the evolution of shared intentionality as an interactional achievement     

Raphaela Heesen  Emilie Genty  Federico Rossano  Klaus Zuberbühler  Adrian Bangerter 《Learning & behavior》2017,45(4):390-405

Social play has a complex, cooperative nature that requires substantial coordination. This has led researchers to use social games to study cognitive abilities like shared intentionality, the skill and motivation to share goals and intentions with others during joint action. We expand this proposal by considering play as a joint action and examining how shared intentionality is achieved during human joint action. We describe how humans get into, conduct, and get out of joint actions together in an orderly way, thereby constructing the state of “togetherness” characteristic of shared intentionality. These processes play out as three main phases, the opening (where participants are ratified and joint commitments are established), the main body (where progress, ongoing commitments, and possible role reversals are coordinated), and the closing (where the intention to terminate the action is coordinated and where participants take leave of each other). We use this process in humans as a framework for examining how various animal species get into, maintain, and get out of play bouts. This comparative approach constitutes an alternative measure of those species’ possession of shared intentionality. Using this framework, we review the play literature on human children and different social species of mammals and birds in search of behavioral markers of shared intentionality in the coordination of play bouts. We discuss how our approach could shed light on the evolution of the special human motivation to cooperate and share psychological states with others.  相似文献   

Community colleges maintain modest response rates to prospective student inquiry     

David Shadinger  Kristin M. Sherry  Hollie L. Smith  Emilie C. Clark 《Community College Journal of Research & Practice》2016,40(5):385-393

None of the community colleges in this study responded with a text message, as requested in the prospective student’s inquiry. Only 1.38% (n = 3) of the institutions responded to the inquiry with a telephone call. This research realized a slightly higher rate of e-mail response within five working days; 54.98% (n = 116) as opposed to the 2009 results of 50.5% (n = 110) in Shadinger’s (2014) study. More community colleges (n = 12, 5.5%) also had e-mail addresses or information request forms (n = 182, 83.5%) than in the original study (n = 170, 78.0%). Nearly 100% of community college websites had social media links, even when an e-mail address or information request form was not available. In an expansion of previous statements about communication, Noel-Levitz (2014a) reported prospective students were “more likely to consider schools that use e-mail, text messages or social media to communicate” (p. 4). Concurrently, the underutilization of e-mail, social media, and cell phones will simply exacerbate communication and recruiting issues for community colleges.  相似文献   

Taylor,T. D. (2017). Music in the World: Selected Essays. Chicago: University of Chicago Press. 243 pages.     

Emilie Hurst 《Journal of Radio & Audio Media》2018,25(2):351-353

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Differential time responses in inflammatory and oxidative stress markers after a marathon: An observational study     

Emil List Larsen  Henrik Enghusen Poulsen  Cristina Michaelsen  Laura Kofoed Kjær  Mark Lyngbæk  Emilie Skytte Andersen 《Journal of sports sciences》2020,38(18):2080-2091

ABSTRACT