40 research outputs found

    Conceptualising a Dynamic Technology Practice in Education Using Argyris and Schön's Theory of Action

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    Despite substantial national effort to integrate technology in education, it seems that practitioners in the education system are not working in line with the given policy. Evidence from large-scale studies of students’ technology practices at school over the last decade show disparities in student practices. The observed gap between the micro and the macro level call for a closer exploration. Research that explores the influence of social and organizational factors may be useful for understanding the processes behind such gaps. Argyris and Schön’s ‘Theory of Action’ (1978) is proposed as an example of an organizational theory that can be adopted in educational technology research to move towards understanding the complexities of technology practice. To encourage discourse and application of Argyris and Schön’s theory in the field of educational technology research, this paper introduces the theory, a review of its empirical application in research of teacher educations’ technology practice and relevant conceptual work. The paper presents a conceptual framework based on Argyris and Schön’s theory that has been developed through two recent studies, and invites its application in future research and development

    Biomonitoring of bisphenol A concentrations in maternal and umbilical cord blood in regard to birth outcomes and adipokine expression: a birth cohort study in Taiwan

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    <p>Abstract</p> <p>Background</p> <p>Bisphenol A (BPA) is a sealant and flux of plastic materials and has been determined to be an endocrine-disrupting chemical. Prenatal exposure to BPA can lead to substantial adverse effects on fetal growth and development. This study was conducted to assess BPA concentration in pregnant women and umbilical cord blood, and to investigate whether maternal BPA exposure affected fetal outcomes including lower birth weight (LBW), smaller size for gestational age (SGA), and high leptin (HLP) and low adiponectin (LAD) secretion.</p> <p>Methods</p> <p>We measured the BPA levels of maternal blood (n = 97) and umbilical cord blood (n = 97) with a high-performance liquid chromatography/UV detector. The protein secretion of leptin and adiponectin were separately determined using enzyme-linked immunosorbent assay. A logistic regression was performed to estimate the effects of maternal exposure to BPA on LBW, SGA, and adverse action of adipokines in newborns.</p> <p>Results</p> <p>The geometric means of BPA concentration in maternal blood and fetal cord blood were 2.5 ng/ml and 0.5 ng/ml, respectively. Elevated risks of LBW (OR 2.42, 95% confidence interval (CI) 1.72-3.36), SGA (OR 2.01, 95% CI 1.39-3.01), and adverse action of leptin (OR 1.67, 95% CI 1.12-2.25) and adiponectin (OR 1.25, 95% CI 1.52-3.97) were observed in male neonates in the highest quartile of maternal BPA exposure.</p> <p>Conclusions</p> <p>Elevated prenatal BPA exposure increased the risk of LBW, SGA, and adverse actions of adipokines in neonates, especially in male infants. These results provide further evidence that maternal exposure is correlated with adverse birth outcomes.</p

    Evaluation of Germination Behaviour and Sowing Date in Dorema, Asafetida and Galbanum

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    Abstract\ud This research was conducted for evaluation of germination treatments and favorite planting date of three medicinal plant species including Dorema (Dorema ammoniacum), Asafetida (Ferula assa-foetida) and Galbanum (Ferula gummosa) in Agricultural College of Ferdowsi University of Mashhad in 2008. Effect of different levels of temperature and washing on germination percent and rate of species were evaluated in first experiment. Temperature in 6 levels including 1, 4, 7, 10, 13 and 20 °C and seeds treatment in 3 levels including drench, washing and extract were surveyed. In the second experiment, emergence condition of species in four planting dates including first December, first January, first April and first May in pot and out door conditions were evaluated. Result showed that, optimum temperature for germination of Dorema, Asafetida and Galbanum plants were 7.83, 8.27 and 3.14 °C, respectively. Further, germination percent of each plant had a positive and significant relation (

    PURIFICATION AND CHARACTERIZATION OF HUMAN MENINGIOMA M2-TYPE PYRUVATE-KINASE

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    The M2-type pyruvate kinase was purified from human meningioma by ammonium sulfate precipitation, followed by ion exchange and affinity chromatography. The specific activity of the purified enzyme was 33.4 U/mg with a yield of 6.5%

    REGULATION OF M2-TYPE PYRUVATE-KINASE FROM HUMAN MENINGIOMA BY ALLOSTERIC EFFECTORS FRUCTOSE 1,6 DIPHOSPHATE AND L-ALANINE

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    In the present study the mechanism of action of M2-type pyruvate kinase from human meningioma in the simultaneous presence of fructose 1,6 diphosphate and L-alanine was investigated. Purified pyruvate kinase from human meningioma was allosterically inhibited by L-alanine with respect to substrates phosphoenolpyruvate and ADP. The inhibitory effects of L-alanine was partially removed by fructose 1,6 diphosphate. The purified enzyme was slightly susceptible to ATP inhibition

    Influence of polymer molecular weight on the in vitro cytotoxicity of poly (N-isopropylacrylamide)

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    Short CommunicationAbstract not availableAmir Mellati, Meisam Valizadeh Kiamahalleh, Sheng Dai, Jingxiu Bi, Bo Jin, Hu Zhan

    Effects of estrogen and progesterone on behavioral impairment and neuronal death in ovariectomized rats induced by methamphetamine

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    Background and purpose: Methamphetamine (METH) is one of the most powerful drugs that leads to many cognitive and behavioral side effects such as anxiety. On the other hand, studies have shown that ovarian hormones such as estrogen and progesterone have neuroprotective effects on a wide range of cognitive and behavioral disorders. The aim of this study was to investigate the role of estrogen and progesterone on anxiety-like behaviors, body temperature, brain edema, and neuronal death induced by neurotoxic regimen of methamphetamine. Materials and methods: This study was performed in 48 ovariectomized rats divided into six groups including: control, METH (6mg / kg), vehicle (sesame oil), METH + estrogen (1mg / kg), METH + progesterone (8mg / kg), and METH + estrogen + progesterone. Body temperature and anxiety-like behaviors were investigated, then, the animals were killed and brain tissues were harvested to evaluate brain edema and neuronal death in hippocampal CA1. Results: Body temperature, brain water content, motor activity, and anxiety-related behaviors significantly increased in animals that received METH (P<0.001), but, treatment with estrogen and progesterone attenuated motor activity, and anxiety-related behaviors induced by METH. Brain edema, body temperature, and neuronal cell death in hippocampal CA1 area partially decreased in METH+estrogen and METH + progesterone groups. Conclusion: This study suggests that ovarian hormones such as estrogen and progesterone are effective in improving behavioral deficits and neuronal death induced by METH in ovariectomized rats. © 2020, Mazandaran University of Medical Sciences. All rights reserved
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