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Science educators have suggested that, for minority and low-income students, gaps between home and school science cultures necessitate ‘border crossing’ for successful learning in science. Our analysis used National Assessment of Educational Progress 2000 and 2005 data to assess the impact of U.S. state-level policy regarding instructional models for language acquisition for the learning of science. Specifically, we assessed whether policy favouring structured English immersion led to better student outcomes than bilingual education among Hispanic English language learners in 4th and 8th grades in the U.S. We found significantly higher science achievement among 4th grade Hispanic ELLs in states with stronger bilingual emphasis in their policy, suggesting that policy support for bilingual education could provide a better bridge to span the cultural gap between home and school science, at least for younger students.  相似文献   
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Transition into higher education (HE) has received increased interest in recent years, since it represents a challenging period for students. The aim of this study was to further understand the associations between self-efficacy, academic achievements, and regulation in first-year university students during their transition into HE. The convenience sample consisted of 374 first-year university students (230 females, 61.5%), aged from 18 to 33 (M = 19.86, SD = 1.51) and recruited from an Italian university. Self-efficacy was assessed using the Motivated Strategies for Learning Questionnaire; regulation strategies were assessed with the Inventory of Learning Patterns of Students; and a self-reported grade point average was taken as an indicator of each student's academic performance. Result shows that students' self-efficacy was positively associated with self-regulation and negatively associated with a lack of regulation. Students with higher self-efficacy and self-regulation strategies had better academic performance. Female students performed better in academic activities and adopted more external regulation strategies. The findings represent an opportunity for university institutions to consider the interventions they provide to first-year students in order to facilitate the successful transition from secondary school; they also provide researchers with further knowledge about the effect of self-efficacy, and regulation strategies on students' adjustment to HE.  相似文献   
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Procedures involving phlebotomy are critical for obtaining diagnostic blood specimens and represent a well known and recognized problem, probably among the most important issues in laboratory medicine. The aim of this report is to show spurious hyperkalemia and hypocalcemia due to inadequate phlebotomy procedure. The diagnostic blood specimens were collected from a male outpatient 45 years old, with no clinical complaints. The tubes drawing order were as follows: i) clot activator and gel separator (serum vacuum tube), ii) K3EDTA, iii) a needleless blood gas dedicated-syringe with 80 I.U. lithium heparin, directly connected to the vacuum tube holder system. The laboratory testing results from serum vacuum tube and dedicated syringe were 4.8 and 8.5 mmol/L for potassium, 2.36 and 1.48 mmol/L for total calcium, respectively. Moreover 0.15 mmol/L of free calcium was observed in dedicated syringe. A new blood collection was performed without K3EDTA tube. Different results were found for potassium (4.7 and 4.5 mmol/L) and total calcium (2.37 and 2.38 mmol/L) from serum vacuum tube and dedicated syringe, respectively. Also free calcium showed different concentration (1.21 mmol/L) in this new sample when compared with the first blood specimen. Based on this case we do not encourage the laboratory managers training the phlebotomists to insert the dedicated syringes in needle-holder system at the end of all vacuum tubes. To avoid double vein puncture the dedicated syringe for free calcium determination should be inserted immediately after serum tubes before EDTA vacuum tubes.  相似文献   
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International Journal of Science and Mathematics Education - Using data from the Trends in International Mathematics and Science Study (TIMSS) 2015 assessment of fourth-grade students in 32...  相似文献   
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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  相似文献   
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In general, studies on gender and mathematics show that the advantage held by boys over girls in mathematics achievement has diminished markedly over the last 40 years. Some researchers even argue that gender differences in mathematics achievement are no longer a relevant issue. However, the results of the Trends in Mathematics and Science Study of 2003 (TIMSS-2003), as well as the participation rates of girls in (advanced) mathematics courses, show that in some countries, such as the Netherlands, gender equity in mathematics is still far from a reality. Research on gender and mathematics is often limited to the relationship between gender differences in attitudes toward mathematics and gender differences in mathematics achievement. In school effectiveness research, theories and empirical evidence emphasize the importance of certain school and class characteristics (e.g., strong educational leadership, safe and orderly learning climate) for achievement and attitudes. However, there is little information available at to whether these factors have the same or a different influence on the achievement of girls and boys. This study used the Dutch data from TIMSS-2003 to explore the relationship between school- and class characteristics and the mathematics achievement and attitudes for both girls and boys in Grade 4 of the primary school. The explorations documented in this paper were guided by a conceptual model of concentric circles and involved multilevel analyses. Interaction effects with gender were assessed for each influencing factor that turned out to have a significant effect. The results of these analyses provide additional insight into the influence that non-school-related and school-related factors have on the mathematics achievement and attitudes of girls and boys.  相似文献   
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