Effectiveness of citrate buffer-fluoride mixture in Terumo tubes as an inhibitor of in vitro glycolysis

Introduction

Glycolysis affects glucose determination in vitro. The placement of sample tubes in ice-water slurry with plasma separation within 30 minutes is recommended, or alternatively the use of a glycolysis inhibitor. The aim of our two-steps study was to evaluate which Terumo tube is best for glucose determination in routine clinical setting.

Materials and methods

In the first study, blood from 100 volunteers was collected into lithium heparin (LH), NaF/Na heparin (FH) and NaF/citrate buffer/Na₂EDTA (FC-Mixture) tubes. LH sample was treated as recommended and considered as reference, while FH and FC-Mixture samples were aliquoted, maintained at room temperature (RT) for 1, 2 and 4 hours; centrifuged and plasma analysed in triplicate. In the second study, samples from 375 volunteers were collected in LH, FH and FC-Mixture tubes and held at RT before centrifugation from 10 to 340 minutes, depending on each laboratory practice. Samples were analysed in one analytical run.

Results

In the first study, FH glucose concentrations were 5.15 ± 0.66 mmol/L, 5.05 ± 0.65 mmol/L and 5.00 ± 0.65 mmol/L (P < 0.001) in tubes stored at RT for 1, 2 and 4 hours, respectively. Mean biases in all time points exceeded the analytical goal for desirable bias based on biological variation criteria. FC-Mixture glucose concentrations were 5.48 ± 0.65 mmol/L, 5.46 ± 0.6 mmol/L and 5.46 ± 0.64 mmol/L in tubes stored at RT for 1, 2 and 4 hours, respectively. Mean biases for FC-Mixture glucose in all time points reached optimal analytical goals. In the second study, the biases for LH and FH glucose compared to reference FC-Mixture glucose exceeded the preset analytical goals, regardless of the blood collection to centrifugation time interval.

Conclusions

FC-mixture tubes glucose concentrations were preserved up to 4h storage at RT. We confirmed that NaF alone does not allow immediate glycolysis inhibition in real life pre-centrifugation storage conditions (up to 340 minutes). FC-Mixture should be used exclusively for glucose determination in laboratories unable to implement the recommended blood samples’ treatment.Key words: glucose, pre-analytical phase, sodium fluoride, citrate acidification, stability     

The effects of a concept map-based information display in an electronic portfolio system on information processing and retention in a fifth-grade science class covering the Earth's atmosphere

An electronic portfolio system, designed to serve as a resource-based learning space, was tested in a fifth-grade science class. The control-group students accessed a traditional folder-based information display in the system and the experimental-group students accessed a concept map-based information display to review a science portfolio. The student-constructed science portfolio was a result of a collection of digital artefacts such as graphic images, instructional videos and textual files on terms and definitions relevant to the Earth's atmosphere. In the information-processing performance test, the experimental-group students scored significantly higher and spent much less time in finding answers to the questions presented. Also, in the 3-day delayed memory retention tests, the experimental-group students achieved significantly higher scores. The multiple regression models confirm that the visualisation variation is the most significant predictor for student performance (ie, comprehension and access time). Also, the regression models suggest that language-arts proficiency may reduce overall system access time; while higher math proficiency may predict retention scores.     

Arguing to learn and learning to argue: Case studies of how students' argumentation relates to their scientific knowledge

In this study we investigated junior high school students' processes of argumentation and cognitive development in science and socioscientific lessons. Detailed studies of the relationship between argumentation and the development of scientific knowledge are rare. Using video and audio documents of small group and classroom discussions, the quality and frequency of students' argumentation was analyzed using a schema based on the work of Toulmin ( 1958 ). In parallel, students' development and use of scientific knowledge was also investigated, drawing on a schema for determining the content and level of abstraction of students' meaning‐making. These two complementary analyses enabled an exploration of their impact on each other. The microanalysis of student discourse showed that: (a) when engaging in argumentation students draw on their prior experiences and knowledge; (b) such activity enables students to consolidate their existing knowledge and elaborate their science understanding at relatively high levels of abstraction. The results also suggest that students can acquire a higher quality of argumentation that consists of well‐grounded knowledge with a relatively low level of abstraction. The findings further suggest that the main indicator of whether or not a high quality of argument is likely to be attained is students' familiarity and understanding of the content of the task. The major implication of this work for developing argumentation in the classroom is the need to consider the nature and extent of students' content‐specific experiences and knowledge prior to asking them to engage in argumentation. © 2007 Wiley Periodicals, Inc. J Res Sci Teach 45: 101–131, 2008     

Maternal and paternal similarities and differences in parenting: An examination of Mexican-American parents of young children

The present study evaluated the degree of parental similarity–dissimilarity across parenting dimensions operationalized in terms of: (1) one's own and one's partner's style; (2) meta-emotion belief structures; (3) behavioral strategies in reaction to children's emotions; as well as (4) parental support and responsiveness. The first four dimensions were assessed with independent self-reports from both mothers and fathers and the latter was measured through observed behaviors in a discussion of emotions. Fifty-seven families participated. The mothers (92%) and fathers (90%) of preschool-aged children (mean age 57.5 months, 54% male) were predominantly of Mexican descent. Results revealed significant similarity when comparing mothers’ and fathers’ observed behaviors. Agreement among parents also emerged when comparing minimizing coping reactions to children's emotional displays and self-reported and reports of one's partner's authoritative parenting. Despite evidence of agreement on use of authoritative strategies and similarity on observed behaviors, comparisons of mean levels revealed dissimilarity. The participating mothers reported a greater tendency to employ authoritative strategies and their partners’ ratings of the mothers’ parenting confirmed this perceived difference. In addition, comparisons of mothers’ and fathers’ observed behaviors in interaction with their children suggested that, while mothers and fathers are engaged in similar behaviors, mothers are observed to engage in them more frequently. These results reinforce the need to assess both parents, employing multiple methods, in determining interdependence or their combined and unique contributions to socializing children.     

Developmental outcomes of children in classes for special educational needs: results from a longitudinal study

This longitudinal study investigates the differences in cognitive and socio‐emotional development and academic achievement between children educated in special education classes (N = 37) and regular classes (N = 37). The study is retrospective. The first measurement point was while children were attending play‐oriented kindergarten and no decision about their education had yet been made. The second measurement point followed after 2 years of schooling. Comparing carefully matched groups, no differences in executive functions (EFs) were found before beginning school. Children assigned to special education had poorer language, fine motor skills and a lower pre‐academic self‐concept, self‐regulatory skills and social integration. Notably, every fourth child in special education was an immigrant, 9% of whom later attended regular classes. After 2 years of schooling in either setting, the groups differed significantly in academic achievement, EFs, fine motor skills and cognitive self‐regulatory skills. However, it was not – as school officials had intended – that children in special education classes had caught up, except in regard to their academic self‐concept and social integration.     

Fulfilling the Promise of Professional Development

It is ironical that developments in the field of education call for teachers to differentiate instruction as a pre-requisite for effective learning,while teacher education and continuing professional development adhere to a one-size-fits-all philos- ophy. In general,professional development initiatives are part of'reform packages'with decisions about what,when,and     

Influence of motherhood on the implicit academic self-concept of female college students: Distinct effects of subtle exposure to cues and directed thinking

Despite notable steps toward gender equality and significant changes in gender roles, women continue to face tension between academic aspirations and the more traditional role of caregiver. The goal of the present research was to examine how this conflict might be revealed through assessments of associations that cannot be consciously controlled. In two experiments, college women completed implicit association tasks measuring the strength of their academic identification. Experiment 1 (N=55) showed that implicit academic identification was weaker when motherhood cues were present (rather than absent). In Experiment 2 (N=73), implicit academic identification was weaker when participants reflected on their aspirations to become a college graduate rather than aspirations to be a mother. These findings emphasize the malleability of the implicit academic self-concept. More precisely, they document that subtle exposure to cues and more deliberate thought processes produce distinct effects. This research contributes to a better understanding of contextual influences on the academic self-concept of college women and their potential implications for academic performances.     

Pocket School: Exploring mobile technology as a sustainable literacy education option for underserved indigenous children in Latin America

Literacy is a human right unequally distributed among the world's population. Despite global efforts to fight illiteracy, high illiteracy rates continue to jeopardize access for many to basic schooling, life-long learning, health, and environment safety. Illiteracy also hinders the economic prosperity of the poorest societies in this digital age. Among the underserved population in Latin America, many of the indigenous children are the poorest of the poor who hardly have access to formal and stable schooling. This paper reviews the literature addressing education inequality issues in Latin America and possible opportunities with mobile learning technology to counter the effects of the education inequality. Also, this paper suggests mobile technology design considerations to meet the particular learning needs of the extremely underserved and underachieving indigenous children in Latin America.     

Advocating and administering critical realism in a study of transnational educational collaborative partnerships

ABSTRACT

Transnational higher education is an increasingly important and essential part of the internationalisation of higher education. As the number of global educational institutions and international students participating in these types of initiatives increases, it becomes of paramount importance that research methodologies that investigate the phenomenon are developed and shared within transnational research communities. This article seeks to contribute to transnational education research by exploring a paradigm that has the potential to generate alternative forms of knowledge concerning transnational collaborative partnerships. By exploring functionalist and interpretivist approaches, often applied in partnership research, this article argues that neither approach, when applied in isolation, can fully articulate the notion of a TNE collaborative partnership. The article therefore champions the application of critical realism when investigating these partnerships and provides an empirical example of two Chinese-British case studies to illustrate the application of the paradigm, followed by a vignette of the type of findings generated, and its value to research and practice.