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81.
While an emerging body of research has examined the effects of school absences on student outcomes, there is comparatively little research examining the different reasons contributing to school absence, how common these reasons are, and the extent to which different types of absences are differentially associated with achievement. To address these gaps, we used data from the Longitudinal Study of Australian Children to examine the reasons for school absence as reported by 14–15 year olds and how these reasons relate to achievement outcomes in Year 9. Only 7% of 14–15 year olds indicated they had been absent in the previous six months without parental consent, of which 46% indicated the most recent absence was due to problems at school. Of the 90% of students who had been absent with parental consent, only 6% said the most recent absence was due to problems at school. After controlling for student, family and school characteristics and Year 7 achievement, Year 9 achievement was most strongly associated with absences related to student‐ or family‐level reasons. While schools typically bear the responsibility for monitoring and responding to absenteeism, the drivers of absence may not be related to factors that schools can realistically address. For schools, addressing absenteeism requires a dual approach of preventing avoidable absences and mitigation strategies for when either avoidable or unavoidable absences occur.  相似文献   
82.
Embryonic stem (ES) cells are capable of proliferating and differentiating to form cells of the three embryonic germ layers, namely, endoderm, mesoderm, and ectoderm. The utilization of human ES cell derivatives requires the ability to direct differentiation to specific lineages in defined, efficient, and scalable systems. Better markers are needed to identify early differentiation. Lectins have been reported as an attractive alternative to the common stem cell markers. They have been used to identify, characterize, and isolate various cell subpopulations on the basis of the presentation of specific carbohydrate groups on the cell surface. This article demonstrates how simple adhesion assays in lectin-coated microfluidic channels can provide key information on the interaction of lectins with ES and definitive endoderm cells and thereby track early differentiation. The microfluidic approach incorporates both binding strength and cell surface receptor density, whereas traditional flow cytometry only incorporates the latter. Both approaches are examined and shown to be complementary with the microfluidic approach providing more biologically relevant information.  相似文献   
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