Why Do Historical Beeswax Seals Become Brittle Over Time?

ABSTRACT

Mechanical properties of aged beeswax were studied by an indirect measurement, using hydrogenated beeswax as a model material. The adequacy of the model was evaluated by comparison of its chemical composition and thermal properties with those of samples of historical beeswax. It was found that the gradual decrease in content of unsaturated compounds in beeswax contributes significantly to changes of its mechanical properties. As a consequence, beeswax artefacts become increasingly prone to mechanical damage during natural ageing. Understanding the difference between mechanical properties of recent and historical beeswax is primarily important from the point of view of safe handling and storage of such artefacts. Besides, this knowledge could help conservation scientists, e. g. when preparing model samples for testing new conservation methods.     

The Physical Educator as Researcher

In an attempt to confront society's drug problem, many colleges and universities have implemented drug testing programs for their student-athletes. While more and more institutions continue to initiate drug testing programs, a number of questions concerning the constitutionality of drug testing remain unanswered. constitutional questions such as due protection against self-incrimination, due process guarantees, and protection against unreasonable searches and seizures are at issue. In light of the many unanswered questions surrounding drug testing, administrators should develop not only a philosophical rationale but also a legal rationale for either having or not having drug testing programs for student-athletes.     

Administrative behavior and student dissatisfaction: A possible relationship

In postwar Bosnia–Herzegovina, segregation along ethno-nationalistic lines and divergent pedagogies within the education system have presented challenges to social cohesion and the long-term stability of a society that is still struggling to rebuild, reconcile, and regain trust (Jancic, 2008 Hromadzic, A. 2008. Discourses of integration and practices of reunification at the Mostar Gymnasium, Bosnia and Herzegovina. Comparative Education Review, 52: 541[Crossref], [Web of Science ®] , [Google Scholar]). This article examines the current state of the education system within (a) leadership, (b) primary and secondary schooling (i.e., segregation, language of instruction, textbooks, and curriculum), (c) school–community relations (parent–teacher associations and international organizations), and (d) higher education. Within each of the four aspects, the article explores the challenges and possibilities for social cohesion presented within schools and through education at the larger societal level in Bosnia–Herzegovina.     

“ADULT ED”‐THE ULTIMATE GOAL A Genuine “Learning Society” Will Require a Philosophy of Continuing Education Adequate to its Potential as a Social Force

It is time that we had uncommon schools, that we did not leave off our education when we begin to be men and women. It is time that villages were universities, and their elder inhabitants the fellows of universities with leisure—if they are indeed so well off—to pursue liberal studies the rest of their lives.—Thoreau, Walden     

New directions in the history of modern science in China: global science and comparative history

These essays collectively present new perspectives on the history of modem science in China since 1900. Fa-ti Fan describes how science under the Republic of China after 1911 exhibited a complex local and international character that straddled both imperialism and colonialism. Danian Hu focuses on the fate of relativity in the physics community in China after 1917. Zuoyue Wang hopes that a less nationalist political atmosphere in China will stimulate more transnational studies of modern science, which will in turn reveal the underlying commonalities in different national contexts. Sigrid Schmalzer compares the socialist and the capitalist contexts for science in China and reopens the sensitive question of the "mass line" during the Cultural Revolution. Grace Shen describes the tensions early Chinese scientists felt when choosing between foreign models for modem geology and their own professional identities in China. Taken together, these accounts present us with a comparative history of modern science in China that is both globally and locally informed.     

Collaboration modality, cognitive load, and science inquiry learning in virtual inquiry environments

Educational multi-user virtual environments (MUVEs) have been shown to be effective platforms for situated science inquiry curricula. While researchers find MUVEs to be supportive of collaborative scientific inquiry processes, the complex mix of multi-modal messages present in MUVEs can lead to cognitive overload, with learners unable to effectively process the rich information encountered in virtual space. In this study, we investigated the effect of communication modality on cognitive load and science inquiry learning in students completing a science inquiry curriculum in an educational MUVE. Seventy-eight undergraduate education majors from a large southwestern university participated in this control-treatment study. Significant positive results were found for reducing cognitive load for participants communicating through voice-based chat, although this reduction was not found to influence learning outcomes. We conclude that use of voice-based communication can successfully reduce cognitive load in MUVE-based inquiry curricula.     

A meta‐analysis of school‐wide positive behavior support: An exploratory study using single‐case synthesis

Positive Behavior Support (PBS) for behavioral problems was included in the 1997 Individuals With Disabilities Education Act reauthorization, reflecting the increased implementation and strengthening empirical evidence for PBS in schools. Whereas PBS can be used reactively, its flexibility has led to a popular comprehensive school‐wide model used for prevention. School‐Wide Positive Behavioral Support (SWPBS) has been used across a variety of school environments and various demographics and has been evaluated using a variety of different outcome measures. The authors conducted a meta‐analysis of SWPBS research spanning 16 years and 20 articles. Specifically, single‐case studies were evaluated using a regression‐based procedure. Results show promising early trends in the data across dependent variables with a need for further research in specific areas. © 2011 Wiley Periodicals, Inc.