Extreme geomagnetic field variability indicated by Eastern Mediterranean full-vector archaeomagnetic records

The magnetic field of the Earth can exhibit considerable variations at short time scales, even as short as decades. The archaeomagnetic studies of Middle Eastern artefacts (mainly from Israel and Jordan) show evidence for an exceptionally high intensity period from 1050-700 BC which displays two distinct spikes over the Levant, the Levantine Iron Age Anomaly (LIAA). Its exact duration and geographical extent are still poorly known. Despite the wealth of ancient settlements, the extensive cultural heritage and a long history of trade and immigration, the archaeomagnetism of Turkey and Cyprus remains largely unexplored. This study presents a large data set of ancient directions and intensities from seven archaeological sites in the Eastern Mediterranean covering a time span of ∼2000 yrs. The recorded directions from thirteen sets of samples are coherent with our earlier findings, yet show significantly larger swings than existing field models. In particular, we confirm the very large swing in inclination we found earlier, from 1910-1850 BC, that is also captured by the Greek PSV curve, and shallower by more than 10° than predicted by existing field models. Consequently, these models require substantial revision in this region. We were able to determine the archaeointensity from five sets of mud-bricks, from the thirteen attempted, allowing us to provide the full field vector. Furthermore, we present thirty-one new archaeointensity results from potsherds and mud-bricks that considerably enhance existing data, especially when a set of strict selection criteria is applied. Fourteen sets of potsherds from a single site (Tell Atchana) provide the longest sequence recorded so far in Turkey, from 2100 to 1350 BC. We find exceptionally high intensities of 145 and 175 ZAm2 around 700 BC, in well-dated mud-bricks and potsherds from two different locations (Tell Tayinat and Kilise Tepe), supporting extreme geomagnetic field variability in the region. Moreover, these two high intensities confirm the younger spike of the LIAA in Turkey

Effect of instruction supplied with the investigative-oriented laboratory approach on achievement in a science course

This study examines the differential effectiveness of the laboratory method based on the investigative approach and the worksheet study, both used as a supplement to the regular class work on achievement in science subject-matter. Subjects were 43 students (8th grade) enrolled in two science classes of a secondary school. Each teaching strategy was randomly assigned to one class. The experimental group utilized supplementary instruction through the investigative-oriented activities; the control group received similar instruction through worksheet study. The Logical Thinking Ability Test was used as a pretest to control students' intellectual ability before treatment. The dependent variable was achievement in science subjects assessed through the use of the Science Subject Achievement Test. All subjects received instruction covering the same science topics during approximately five weeks. It was found that both treatment groups had statistically identical performance related to logical thinking ability at the beginning of the treatment. The subjects taught by the investigative-oriented laboratory activities earned significantly higher science achievement scores than those taught by the worksheet study. It was concluded that the supplementary instruction with the investigative-oriented laboratory activities seemed to be more suitable for teaching science subjects

The nature of pre-­‐service science teachers’ argumentation in inquiry-­‐oriented laboratory context

The aim of this study was to investigate the kinds of argumentation schemes generated by pre-service elementary science teachers (PSTs) as they perform inquiry-oriented laboratory tasks, and to explore how argumentation schemes vary by task as well as by experimentation and discussion sessions. The model of argumentative and scientific inquiry was used as a design framework in the present study. According to the model, the inquiry of scientific topics was employed by groups of participants through experimentation and critical discussion sessions. The participants of the study were 35 PSTs, who teach middle school science to sixth through eighth grade students after graduation. The data were collected through video- and audio-recordings of the discussions made by PSTs in six inquiry-oriented laboratory sessions. For the analysis of data, pre-determined argumentation schemes by Walton were employed. The results illustrated that PSTs applied varied premises rather than only observations or reliable sources to ground their claims or to argue for a case or an action. It is also worthy of notice that the construction and evaluation of scientific knowledge claims resulted in different numbers and kinds of arguments. Results of this study suggest that designing inquiry-oriented laboratory environments, which are enriched with critical discussion, provides discourse opportunities that can support argumentation. Moreover, PSTs can be encouraged to support and promote argumentation in their future science classrooms if they engage in argumentation integrated instructional strategies

The pedagogy of argumentation in science education: Science teachers’ instructional practices

Argumentation has been a prominent concern in science education research and a common goal in science curriculum in many countries over the past decade. With reference to this goal, policy documents burden responsibilities on science teachers, such as involving students in dialogues and being guides in students’ spoken or written argumentation. Consequently, teachers’ pedagogical practices regarding argumentation gain importance due to their impact on how they incorporate this practice into their classrooms. In this study, therefore, we investigated the instructional strategies adopted by science teachers for their argumentation-based science teaching. Participants were one elementary science teacher, two chemistry teachers, and four graduate students, who have a background in science education. The study took place during a graduate course, which was aimed at developing science teachers’ theory and pedagogy of argumentation. Data sources included the participants’ video-recorded classroom practices, audio-recorded reflections, post-interviews, and participants’ written materials. The findings revealed three typologies of instructional strategies towards argumentation. They are named as Basic Instructional Strategies for Argumentation, Meta-level Instructional ‌St‌‌rategies for ‌Argumentation, and Meta-strategic Instructional ‌St‌‌rategies for ‌Argumentation. In conclusion, the study provided a detailed coding framework for the exploration of science teachers’ instructional practices while they are implementing argumentation-based lessons

The pedagogy of argumentation in science education: Science teachers’ instructional practices

Argumentation has been a prominent concern in science education research and a common goal in science curriculum in many countries over the past decade. With reference to this goal, policy documents burden responsibilities on science teachers, such as involving students in dialogues and being guides in students’ spoken or written argumentation. Consequently, teachers’ pedagogical practices regarding argumentation gain importance due to their impact on how they incorporate this practice into their classrooms. In this study, therefore, we investigated the instructional strategies adopted by science teachers for their argumentation-based science teaching. Participants were one elementary science teacher, two chemistry teachers, and four graduate students, who have a background in science education. The study took place during a graduate course, which was aimed at developing science teachers’ theory and pedagogy of argumentation. Data sources included the participants’ video-recorded classroom practices, audio-recorded reflections, post-interviews, and participants’ written materials. The findings revealed three typologies of instructional strategies towards argumentation. They are named as Basic Instructional Strategies for Argumentation, Meta-level Instructional ‌St‌‌rategies for ‌Argumentation, and Meta-strategic Instructional ‌St‌‌rategies for ‌Argumentation. In conclusion, the study provided a detailed coding framework for the exploration of science teachers’ instructional practices while they are implementing argumentation-based lessons

QSAR study on antibacterial and antifungal activities of some 3,4-disubstituted-1,2,4-oxa(thia)-diazole-5(4 H)-ones(thiones) using physicochemical, quantumchemical and structural parameters

This work demonstrated the quantitative structure-activity relationships of 3,4-disubstituted-1,2,4-oxa(thia)-diazole-5(4 H)-ones (thiones) using quantum chemical parameter R(I), hydrophobicity descriptor and structural parameters. Semiempirical molecular orbital calculations were used to determine the quantum chemical parameter R(I), which is the electron density of HOMO at the sulfur and oxygen in position 1 of the compounds investigated, divided by the orbital energy of HOMO. It was shown that the electron density of HOMO at the sulfur and oxygen of the molecules was strongly related to the biological activities of these molecules. The results obtained from the QSAR application indicated that there was a parabolic dependence between the biological activities and the R(I) index. The structural factor I-Y which shows the presence of a sulfur atom in position 1 was the dominant predictor for the antibacterial and antifungal activities. On the other hand, the other structural variable I-X which shows the presence of a sulfur atom double bonded to the C atom in position 5 caused a decrease, but the hydrophobicity of the whole molecule (Sigma) caused an increase in activity. (C) 1999 Editions scientifiques et medicales Elsevier SAS

An investigation of elementary students' scientific literacy levels

Scientific literacy has become the major goal of science education in many countries as well as Turkey. In line with this goal, the purpose of this study is to investigate the scientific literacy level of elementary students in Turkey. In this study, the scientific literacy level of students is investigated through "Scientific Literacy Test" adapted by the researchers. The test was administered to 946 elementary students enrolled in 6th, 7th and 8th grades in nine cities during the academic year of 2008-2009. The results of the study showed that 8th grade students significantly differ in their scientific literacy level compared to 6th and 7th grade students. However, eight graders have also some difficulties on some items related to the nature of science