Found in all eukaryotic cells, linker histones H1 are known to bind to and rearrange nucleosomal linker DNA. In vitro, the fundamental nature of H1∕DNA interactions has attracted wide interest among research communities-from biologists to physicists. Hence, H1∕DNA binding processes and structural and dynamical information about these self-assemblies are of broad importance. Targeting a quantitative understanding of H1 induced DNA compaction mechanisms, our strategy is based on using small-angle x-ray microdiffraction in combination with microfluidics. The usage of microfluidic hydrodynamic focusing devices facilitates a microscale control of these self-assembly processes, which cannot be achieved using conventional bulk setups. In addition, the method enables time-resolved access to structure formation in situ, in particular, to transient intermediate states. The observed time dependent structure evolution shows that the H1∕DNA interaction can be described as a two-step process: an initial unspecific binding of H1 to DNA is followed by a rearrangement of molecules within the formed assemblies. The second step is most likely induced by interactions between the DNA and the H1's charged side chains. This leads to an increase in lattice spacing within the DNA∕protein assembly and induces a decrease in the correlation length of the mesophases, probably due to a local bending of the DNA. 相似文献
Education and Information Technologies - Computational thinking in the educational environment has awaken a rising interest, having been included as part of the curricula from the very beginnings... 相似文献
La incidencia de las competencias lingüistícas del escolar sobre las adquisiciones escolares en las demás áreas del currículum es una realidad que todos los maestros pueden comprobar día a día. En este trabajo se investiga esa incidencia, medida a través de la variable fracaso escolar, y sus resultados podrían permitir extraer algunos principios de intervención educativa precoz en algunos aspectos del lenguaje cruciales para la escolaridad posterior. 相似文献
The methodology of protecting the European stained glass windows against environmental risk (e.g. meteorological factors, air pollution, microorganisms) by means of an external glazing is not new. In spite of many scientific studies carried out in the last 20 years, some questions were still up for discussion. The European VIDRIO (2002–2005) project gave an answer to these questions. The research carried out by the different project partners established a new multidisciplinary approach aimed at evaluating the efficiency of the protective glazing systems and their effects on stained glass windows conservation, and finally at assessing the most appropriate strategy to preserve stained glass windows. Scientific results showed that the so-called isothermal glazing (i.e. ventilation by the air coming from the inside of the building) protected efficiently the ancient stained glass window from environmental attack (i.e. rain, pollutants, condensation, thermal shocks) with very limited secondary effects. The scientific research highlighted that its efficiency was strongly related to the technical design of the protective system. In particular, the ventilation and the size of the interspace had to be carefully considered. The research developed within the VIDRIO project was turned into general recommendations to the owners and practitioners on the best practice for the stained glass windows future conservation. 相似文献
Research in Science Education - The theory of evolution is the backbone of the biological sciences. Arguably, this is the reason why evolution education is an extensively investigated issue in... 相似文献
Research in Science Education - This research draws on Legitimation Code Theory (LCT) to understand the epistemic dimension of the higher education classroom discourse of a professor who is well... 相似文献
Covid-19 literacy, induced by the coronavirus disease (2019), is characterized as the understanding of Covid-19 as well as informed decisions based upon this understanding. This type of literacy is closely related to health literacy, scientific literacy, and scientific media literacy. It may be obvious to say that Covid-19 literacy is a key factor for governments to effectively manage the Covid-19 transition. However, lack of literature exists about Covid-19 literacy among university students. Therefore, the current study aimed to determine the Covid-19 literacy level among 4168 students from a Colombian university. The data were derived from students’ responses to a 25–item anonymous online self-reporting questionnaire. We found that 21–25-year age group, graduate students,?students enrolled prior to 2015, and medical students had a significantly higher mean score. Moreover, the Internet (86.8%) was the most popular source of information from which participants gained most information regarding Covid-19. Furthermore, 58.5% of the participants considered health workers as a source that can provide accurate information. Most importantly, the findings reveal the students’ knowledge about (1) the role of an eventual process of vaccination, (2) the test currently used as diagnostic for Covid-19, and (3) the fatality rate, three aspects of Covid-19 literacy that deserve more attention. The findings provide a useful basis for the formulation of policies and concrete actions in improving Covid-19 literacy.
The purpose of this study was to determine the effects of various mastery criteria on student performance and attitude in
a course in which mastery learning strategies were employed.
Undergraduates in an introductory course in educational psychology were randomly assigned to one of three treatments—one in
which mastery criteria gradually increased from 70% to 90%, a second in which mastery criteria gradually decreased from 90%
to 70%, or a third in which mastery criteria remained constant at 80%. Results indicated that although the high mastery criterion
(90%) had a positive effect on some aspects of quiz performance, it did not have an effect on final examination performance.
Results also indicated that students preferred that mastery criteria remain constant during a semester. These findings, when
examined in light of previous research, call into question some prior notions regarding the levels at which mastery criteria
should be set. 相似文献
This study examined whether the criteria for mastering unit quizzes in a mastery-oriented course should increase, decrease,
or remain fixed across units. Subjects were randomly assigned to one of three treatments, one in which mastery criteria on
unit quizzes gradually increased, a second in which mastery criteria gradually decreased, and a third in which mastery criteria
remained fixed. Results indicated that students in the fixed criterion condition proceeded through the course at the steadiest
pace and performed better than the other students on the unit quizzes they mastered. In addition, the vast majority of subjects
indicated that they preferred the fixed criterion condition. These results strengthen the notion that the level of performance
expected of students in a mastery-oriented course should not vary across units. 相似文献