172 research outputs found

    Scale development for pre-service mathematics teachers’ perceptions related to their pedagogical content knowledge

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    The purpose of this study is to develop a scale to determine pre-service mathematics teachers’ perceptions related to their pedagogical content knowledge. Firstly, a preliminary perception scale of pedagogical content knowledge was constructed and then administered to 112 pre-service mathematics teachers who were enrolled in a mathematics teacher education programme. Exploratory and confirmatory factor analysis, item analysis, correlation analysis, internal consistency and descriptive statistic techniques were used to analyse the data. Then validity and reliability of the scale were investigated. The analyses resulted in the development of a five-factor scale of 17 items that was proved valid and reliable. We contend that the scale developed has the merit to contribute to pre-service teachers’ self-awareness by revealing their perceptions regarding their pedagogical content knowledge.Keywords: pedagogical content knowledge, pre-service mathematics teachers,scale developmen

    Red Cell Distribution Width and Acute Complications of Diabetes

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    Context. Red cell distribution width (RDW) has been associated with type 2 diabetes (T2DM), however data in relation to diabetic ketoacidosis (DKA) and hyperglycemic hyperosmolar non-ketotic acidosis (HONK) remains unclear. Objective. The aim of this study was to evaluate the association between RDW, MCV, and RDW/MVC values and acute complications in T2DM. Patients and Methods. RDW was measured in 90 T2DM patients (30 DKA, 30 HONK and 30 T2DM without acute complications). Clinical variables were analyzed by One -Way ANOVA, Kruskal-Wallis and Pearson analysis with SPSS software. Diagnostic screening tests and ROC curve analysis determined the cut-off point of MCV,RDW and RDW/MCV values. Results. DKA patients had higher levels of plasma glucose (524.20 +/- 201.43mg/dL, p<0.001), HbA1c (10.73 +/- 2.29%, p<0.001), osmotic pressure (310.32 mosm/L, p<0.001), RDW (14.61 +/- 1.75g/L, p<0.01), and the RDW/MCV ratio (0.17 +/- 0.04%, p<0.01), compared to HONK patients. RDW/MCV cut-off value was 0.15 with 90% sensitivity 50% specifity these values for only MCV were 76.67%-70%, for only RDW were 76.67%-63.33% respectively. The area under curve values for the ability to reflect DKA for RDW and the RDW/MCV ratio were 0.708 and 0.766, respectively (p<0.001). Conclusions. RDW and RDW/MCV ratio were found associated with DKA and valuable in predicting DKA. However these parameters were not valuable in predicting HONK

    Two-dimensional rule language for querying sensor log data: a framework and use cases

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    Motivated by two industrial use cases that involve detecting events of interest in (asynchronous) time series from sensors in manufacturing rigs and gas turbines, we design an expressive rule language DslD equipped with interval aggregate functions (such as weighted average over a time interval), Allen’s interval relations and various metric constructs. We demonstrate how to model events in the uses cases in terms of DslD programs. We show that answering DslD queries in our use cases can be reduced to evaluating SQL queries. Our experiments with the use cases, carried out on the Apache Spark system, show that such SQL queries scale well on large real-world datasets

    The virtual knowledge graph system Ontop

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    Ontop is a popular open-source virtual knowledge graph system that can expose heterogeneous data sources as a unified knowledge graph. Ontop has been widely used in a variety of research and industrial projects. In this paper, we describe the challenges, design choices, new features of the latest release of Ontop v4, summarizing the development efforts of the last 4 years

    Comparative study of the biochemical changes and volatile compound formations during the production of novel whey-based kefir beverages and traditional milk kefir

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    Cheese whey (CW) and deproteinised cheese whey (DCW) were investigated for their suitability as novel substrates for the production of kefir-like beverages. Lactose consumption, ethanol production, as well as organic acids and volatile compounds formation, were determined during CW and DCW fermentation by kefir grains and compared with values obtained during the production of traditional milk kefir. The results showed that kefir grains were able to utilise lactose from CW and DCW and produce similar amounts of ethanol (7.8–8.3 g/l), lactic acid (5.0 g/l) and acetic acid (0.7 g/l) to those obtained during milk fermentation. In addition, the concentration of higher alcohols (2-methyl-1-butanol, 3-methyl-1-butanol, 1-hexanol, 2-methyl-1-propanol, and 1-propanol), ester (ethyl acetate) and aldehyde (acetaldehyde) in cheese whey-based kefir and milk kefir beverages were also produced in similar amounts. Cheese whey and deproteinised cheese whey may therefore serve as substrates for the production of kefir-like beverages similar to milk kefir.The authors acknowledge the financial support from Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES), CAPES-GRICES and Lactogal for supplying cheese whey powder

    Collision sellar lesions: experience with eight cases and review of the literature

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    The concomitant presence of a pituitary adenoma with a second sellar lesion in patients operated upon for pituitary adenoma is an uncommon entity. Although rare, quite a great variety of lesions have been indentified coexisting with pituitary adenomas. In fact, most combinations have been described before, but an overview with information on the frequency of combined pathologies in a large series has not been published. We present a series of eight collision sellar lesions indentified among 548 transsphenoidally resected pituitary adenomas in two Neurosurgical Departments. The histological studies confirmed a case of sarcoidosis within a non-functioning pituitary adenoma, a case of intrasellar schwannoma coexisting with growth hormone (GH) secreting adenoma, two Rathke’s cleft cysts combined with pituitary adenomas, three gangliocytomas associated with GH-secreting adenomas, and a case of a double pituitary adenoma. The pertinent literature is discussed with emphasis on pathogenetic theories of dual sellar lesions. Although there is no direct evidence to confirm the pathogenetic relationship of collision sellar lesions, the number of cases presented in literature makes the theory of an incidental occurrence rather doubtful. Suggested hypotheses about a common embryonic origin or a potential interaction between pituitary adenomas and the immune system are presented

    Synthesis and characterization of new PNNP-type chiral ligands

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    Polydentate ligands having both soft and hard centers are very effective ligands for the preparation of transition metal complexes. PNNP-type tetradentate diaminodiphosphine ligands are most preferred ligand types cause of their good efficiency for the asymmetric reactions. In this study, three different iminophosphine derivative PNNP-type chiral ligands were synthesized using (R)-(+)-1,1'-Binaphthyl-2,2'-diamine (R-BINAM) and dıphenylphosphıno benzaldehyde derivatives. © 2018, © 2018 Taylor & Francis Group, LLC.British Association for Psychopharmacology: FBA-2018-10690, FDK-2016-5962This work was supported by the Scientific Research Projects Program (BAP No: FDK-2016-5962 and FBA-2018-10690), C¸ukurova University, Turkey

    Deposition of palladium by the hydrogen assisted on SBA-15 with a new precursor using supercritical carbon dioxide

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    Preparation of SBA-15 supported palladium nanoparticles by H2-assisted chemical reduction of a new phenylic precursor dichloro(1,10-phenanthroline) palladium(II) with supercritical carbon dioxide deposition was studied in mild conditions. The solubility study of the precursor in supercritical carbon dioxide was measured under various pressure at 353 K in order to optimize the operating parameters for the metal deposition study. The deposition experiments were performed under 17.2 MPa pressure at 353 K within 8 h. It was found that homogeneous well-dispersed Pd nanoparticles on SBA-15 with a size average of 17.05 ± 1.79 nm determined with HR_TEM images. It was found that Pd nanoparticles deposited in the channel of the porous, into the pores and outer surface of the SBA-15 support. XRD and HR_TEM results showed that obtained Pd nanoparticles are far smaller than particles prepared by H2 reduction method in scCO2 in literature. © 2017 Elsevier B.V.FDK-2015-3668 Firat University Scientific Research Projects Management UnitThis project was financially supported by Scientific and Technological Research Council of Turkey ( TÜBİTAK-BIDEB 2211-E domestic graduate scholarship program) and Management Unit of Scientific Research Projects of Çukurova University (BAP-project no: FDK-2015-3668 under thesis). These are gratefully acknowledged
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