Concurrent and longitudinal predictors of calculation skills in preschoolers

Early calculation abilities in preschoolers are predictive of mathematics achievement in subsequent grades (e.g., Jordan et al. 2009). Two studies were conducted to evaluate concurrent and longitudinal predictors of early calculation skills. In the first study, 102 preschoolers (57.8 % female; mean age?=?60.57?±?8.66 months) were given vocabulary, language comprehension, and verbal working memory tasks and a test battery that evaluated components of early number competence (quantity comparison, counting, number line, size seriation, semantic knowledge of digits, visual-spatial memory). The children were also asked to complete early calculation tasks, including addition and subtraction calculations. The results of this task constituted the dependent variable. The results showed that vocabulary, size seriation, and visual-spatial memory were significant concurrent predictors of early calculation competence. In the second study, 43 children completed the early number competence battery at time 1 (53.5 % female; mean age?=?59.30?±?3.46 months) and the linguistic and early calculation tasks at time 2, about 10 months later (mean age?=?69.43?±?3.31 months). The analysis of the longitudinal predictors of early calculation showed significant effects for counting and size seriation. The implications for preschool assessment and intervention are discussed.     

CPV边界积分的对称数值求积法

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Preservice teachers’ use of contrasting cases in mathematics instruction

Drawing comparisons between students’ alternative solution strategies to a single mathematics problem is a powerful yet challenging instructional practice. We examined 80 preservice teachers’ when asked to design a short lesson when given a problem and two student solutions—one correct and one incorrect. These micro-teaching events were videotaped and coded, revealing that fewer than half of participants (43%) made any explicit comparison or contrasts between the two solution strategies. Those who did were still not likely to use additional support strategies to draw students’ attention to key elements of the comparison. Further, correlations suggest that participants’ mathematical content knowledge may be related to whether participants’ showed contrasting cases but not to whether they used specific pedagogical cues to support those comparisons. While these micro-teaching events differ from the interactive constraints of a classroom, they reveal that participants did not immediately orient toward differing student solutions as a discussion opportunity, and that future instruction on contrasting cases must highlight the utility of this practice.     

Infrared Absorption Spectra of Serpentine Cat＇s Eye from Sichuan Province of China

Infrared （IR） absorption spectra and X-ray powder diffraction （XRD） patterrns of sexpenfine cat＇s eye from Sichuan Province have been investigated, and infrared absorption bands of the serpentine have been assigned in this paper. The results indicate that the bands near 3 600 - 3 700 cm^-1 belong to the stretching absorption band VOH, the bands in 948 - 1 100 cm^-1 axe assigned to the stretching vibraling band Usvo, and the bands at 600 570 and 440 cm^-1 respectively belong to the bending vibration band VOH, δMg-O and δSi-O. The serpentine cat＇ s eye includes two types： chrysotile and antigorite. Chrysotile has a sharp and intensive band at 3 688 cm^-1 and a weak band at 3 643 cm^-1 , while antigorite has only one intensive band in the region. At vibration band VSi-O, chrysotile and antigorite have a similar feature at 1 071 cm^-1, but the band at 980 cm^-1 in anfigorite has been split into two bands in chrysotile - a strong one at 1 027 cm^-1 and a weak one at 949 cm^-1. In addition, antigorite has a characteristic bending vibrating band δMg-O at 570 cm^-1. Based on the analysis of the feature of crystal structure, their IR differences axe well explained.     

Indigenous cultural contexts for STEM experiences: snow snakes’ impact on students and the community

Opportunities for American Indian youth to meaningfully engage in school-based science, technology, engineering, and mathematics (STEM) experiences have historically been inadequate. As a consequence, American Indian students perform lower on standardized assessments of science education than their peers. In this article we describe the emergence of meaning for students—as well as their community—resulting from Indigenous culturally-based STEM curriculum that used an American Indian tradition as a focal context. Specifically, the game of snow snakes (Gooneginebig in Ojibwe) afforded an opportunity for STEM and culturally-based resources to work in unison. A case study research design was used with the bounded case represented by the community associated with the snow snake project. The research question guiding this study was: What forms of culturally relevant meaning do students and the community form as a result of the snow snake game? Results indicate evidence of increased student and community engagement through culturally-based STEM experiences in the form of active participation and the rejuvenation of a traditional game. Implications are discussed for using culturally-based contexts for STEM learning.     

Research of technical knowledge and creativity development of children in pre-primary education through interactive whiteboard

The introduced study represents methodology and results of research focused on utilization of interactive whiteboard as didactic technology mediating information through multimedia worksheets applied in education process in pre-primary education. Its aim was to determine whether it can significantly increase the level of children’s acquired knowledge in the field of technical skills education and whether it can positively influence the development of children’s creative skills as a sign of their motivation. We observe that this issue in the way it is theoretically and practically established in this study can contribute by proposing education standards and set of multimedia worksheets in the technical field in Slovak pre-primary education.     

Clinical analysis of minimally invasive McKeown esophagectomy in a single center by a single medical group

Objective: McKeown esophagectomy followed by cervical and abdominal procedures has been commonly used for invasive esophageal carcinoma. This minimally-invasive operative procedure in the lateral prone position has been considered to be the most appropriate method. We describe our experiences in minimally invasive McKeown esophagectomy (MIME) for esophageal cancer. Methods: Between March 2016 and February 2018, a total of 82 patients underwent MIME by a single group in our department (a single center). All procedure, operation, oncology, and complication data were reviewed. Results: All MIME procedures were completed successfully, with no conversions to open surgery. The median operative time was 260 min, and median blood loss was 100 ml. The average number of total harvested lymph nodes was 20.1 in the chest and 13.5 in the abdomen. There were no deaths within 30 postoperative days. Twenty cases (24.4%) developed postoperative complications, including anastomotic leak in 4 (4.9%), single lateral recurrent nerve palsy in 4 (4.9%), bilateral recurrent nerve palsy in 1 (1.2%), pulmonary problems in 3 (3.7%), chyle leak in 1 (1.2%), and other complications in 7 (including pleural effusions in 4, incomplete ileus in 2, and neck incision infection in 1; 8.54%). Average postoperative hospitalization time was 12 d. Blood loss, operation time, morbidity rate, and the number of harvested lymph nodes were analyzed by evaluating learning curves in different periods. Significant differences were found in operative time (P=0.006), postoperative hospitalization days (P=0.015), total harvested lymph nodes (P=0.003), harvested thoracic lymph nodes (P=0.006), and harvested abdominal lymph nodes (P=0.022) among different periods. Conclusions: Surgical outcomes following MIME for esophageal cancer are safe and acceptable. The MIME procedure for stages I and II could be performed proficiently and reached an experience plateau after approximately 25 cases.     

The Talking Drawings Strategy: Using Primary Children’s Illustrations and Oral Language to Improve Comprehension of Expository Text

Listening and reading comprehension can be assessed by analyzing children’s visual, verbal, and written representations of their understandings. “Talking Drawings” (McConnell, S. (1993). Talking drawings: A strategy for assisting learners. Journal of Reading, 36(4), 260–269 is one strategy that enables children to combine their prior knowledge with the new information derived from an expository text and “translate” those newly-acquired understandings into other symbol systems, including an oral discussion with a partner, a more detailed drawing, and written labels for the drawing. The Talking Drawings strategy begins by inviting children to create pre-learning drawings. These initial drawings are a way of taking inventory of a child’s current content knowledge about a particular topic. After pre-learning drawings are created and shared, children listen to or read an expository text (e.g., information book, passage from a textbook) on the same topic as their drawing. Pairs of students discuss the information and either modify their pre-learning drawings to be more detailed or create completely new drawings that reflect the recently-acquired information. Students are encouraged to label their drawings with words in a diagram or schematic fashion. By evaluating the “before” and “after” artwork, educators can identify advances in students’ reading and listening comprehension of the terminology, facts, and principles on a particular topic.     

„Jeder Schule ihre Lehrer“?

Neue Personalauswahl- und Einstellungsverfahren, an denen die Einzelschulen ma?geblich beteiligt werden, kommen bei der Besetzung von Lehrerstellen in zahlreichen Bundesl?ndern seit Mitte der 1990er-Jahre zur Anwendung und haben mittlerweile die herk?mmlichen zentralen Auswahl- und Zuweisungsverfahren zumindest in einigen von ihnen nahezu vollst?ndig abgel?st. Die Praxis und Wirkung der neuen Auswahlverfahren wurde bislang allerdings nicht systematisch untersucht. In diesem Beitrag werden empirische Befunde einer Untersuchung von Schulen in Nordrhein-Westfalen vorgestellt, die im Jahr 2002 freie Lehrerstellen über das neue Ausschreibungsverfahren besetzt haben. Erfasst wurden unter anderem die in der Praxis angewandten Kriterien der Personalauswahl und die Inhalte der Auswahlgespr?che, die Beurteilung des neuen Auswahl- und Einstellungsverfahrens durch die beteiligten Schulleitungen und Mitglieder der Auswahlkommissionen, Einsch?tzungen und Erfahrungen der neu eingestellten Lehrkr?fte sowie der Verlauf ihrer Berufseinstiegsphase und ihre Bew?hrung am neuen Arbeitsplatz.