An Analyses and Meta-Synthesis of Research on STEM Education

The purpose of the current study is to draw an outline of empirical research studies conducted on STEM education with a focus on student achievement, in addition to their creativity and problem solving skills, attitudes and interests towards STEM subjects. After an initial screening of several articles, papers and dissertations on STEM education, 33 studies are selected according to their fit into our research framework. These selected studies are exposed to analysis and synthesis processes in line with the stages of meta-synthesis research method to specify and present findings under the specified themes. The findings include the strong alignment between STEM education principles and international comparison studies, such as PISA/TIMSS, as well as a positive impact of STEM education on student achievement at school and on their attitudes towards individual STEM disciplines. There is also evidence to support that interventions that follow STEM education principles reinforce students’ problem solving and creativity. Keywords: STEM education, meta-synthesis studies, science and mathematics educatio

Phytochemical compositions, antioxidant properties, enzyme inhibitory effects of extracts of four endemic Lathyrus L. taxa from Türkiye and a taxonomic approach

ABSTRACT Lathyrus is an economically important genus, with different parts of some species used as foodstuff or animal feed. In this study, phytochemical compositions and bioactivities of Lathyrus brachypterus var. brachypterus, L. brachypterus var. haussknechtii, L. nivalis subsp. sahinii and L. tefennicus taxa which are endemic to Türkiye were investigated. Total phenolic and flavonoid contents (TPC, TFC) of methanolic extracts were detected. Then, phytochemical compositions, antioxidant features (radical scavenging (DPPH: 1,1-diphenyl-2-picrylhydrazyl, ABTS: 2,2′-azino-bis(3 ethylbenzothiazoline) 6 sulfonic acid), reducing power (FRAP:Ferric ion reducing antioxidant power, CUPRAC:Cupric ion reducing antioxidant capacity), metal chelating activity (MCA), and the phosphomolybdenum assays (PDA)) and enzyme inhibitory properties of the extracts were also determined. The highest values were found at L. brachypterus var. brachypterus for TPC, L. brachypterus var. haussknechtii for TFC. The highest antioxidant properties were seen in extracts of L. brachypterus var. brachypterus in DPPH, ABTS, FRAP, CUPRAC and PDA assays, while in extract of L. nivalis subsp. sahinii in MCA. The highest enzyme inhibitory activity was found in extract of L. brachypterus var. brachypterus in tyrosinase and glucosidase assays, while in extracts of L. nivalis subsp. sahinii in AChE (acetylcholinesterase), BChE (butyrylcholinesterase) and amylase. Finally, a taxonomic evaluation was made by considering the phytochemicals

Variability of phenolic composition and tocopherol content of some commercial Almond cultivars

The phenolic (gallic acid, catechin, caffeic acid, chlorogenic acid, epicatechin, ferulic acid, kaempferol, naringenin, and p-coumaric acid) and tocopherol contents (α, β, γ, and δ) of some commercially significant almond cultivars were determined in the research. Wide variations in phenolic and tocopherol contents were detected among the cultivars in the research. The highest rate among the phenolic substances was obtained in catechin, with the average values of 27.35 µg g-1 in 2008 and 39.87 µg g-1  in 2009. The highest catechin content was recorded in cultivar ‘Ferraduel’ in both years, with the values of 117.59 µg g-1 in 2008 and 145.86 µg g-1 in 2009. The highest rate among the tocopherols was obtained in α-tocopherol, and the average values were detected as 312.29 mg kg-1 in 2008 and 467.31 mg kg-1 in 2009. The highest α-tocopherol contents were determined as 899.49 mg kg-1 and 945.41 mg kg-1  in cultivar ‘Supernova’ in both years, respectively. In the research, α-tocopherol turned out to be the major tocopherol

Determination of Optimum Filter Size for Detecting Yarn Boundaries

The gray line profile method is widely used for detecting the boundaries between yarns in woven fabric surface images. One lack of the approach is the absence of generally accepted filtering method to eliminate minimum values which do not correspond to the yam boundaries. Aim of this research is to propose a method which automatically determines the filter size for sliding filters so as to detect the true local minimum points those correspond to the boundary positions of weft and warp yarns. The method is tested with real fabric images. Experimental findings demonstrate the effectiveness of the method

Preschool STEM Activities: Preschool Teachers' Preparation and Views

WOS:000521879100002The aim of this study was to determine preschool teachers' STEM training, STEM classroom activities, lesson planning processes, problems, and evaluation strategies and methods during activities. The study sample consisted of 20 preschool teachers. Participants were recruited using criterion sampling, which is a purposive sampling method. This was a case study, which is a qualitative research method. Data were collected using a semi-structured interview form. Qualitative data were analyzed inductive content analysis. Themes, categories, and codes were developed according to the content analysis results in line with the research purpose. Content analysis results showed that participants implemented different preschool STEM activities and used different strategies, methods, and techniques while implementing those activities. They also stated that they faced various problems during those activities. They stated that the STEM training helped them to develop professional competence. However, they had difficulty planning lessons in line with STEM education, due to lack of content knowledge

Projection profile analysis for skew angle estimation of woven fabric images

In this paper, a skew angle detection method based on projection profile analysis is introduced for woven fabric images. The horizontal or vertical projection profiles (VPPs) of woven fabrics tend to fluctuate in bigger magnitudes as the skewed image rotation approaches to the aligned position of the horizontal or vertical yarns in respect of the image edges. The image is rotated through a range of angles and horizontal or VPPs are computed at each angle. In order to detect the skew angle, difference values are computed from adjacent elements of projection profiles. Standard deviation of the difference values for each angle is used as a criterion of the tested skew angles. Experimental results show that the projection profile analysis is suitable for skew angle estimation of woven fabric images