The purpose of this article is to identify some necessary conditions of learning. To learn something, the learner must discern what is to be learned (the object of learning). Discerning the object of learning amounts to discerning its critical aspects. To discern an aspect, the learner must experience potential alternatives, that is, variation in a dimension corresponding to that aspect, against the background of invariance in other aspects of the same object of learning. (One could not discern the color of things, for instance, if there was only one color.) The study results illustrate that what students learn in a sequence of lessons is indeed a function of the pattern of variation and invariance constituted in that sequence. All teachers make use of variation and invariance in their teaching, but this study shows that teachers informed by a systematic framework do it more systematically, with striking effects on their students' learning.

The objective of this study, a parallel study to global gene expression profiling, was to identify dysregulated microRNAs (miRNAs) associated with endometrioid endometrial adenocarcinoma (EEC), examine their correlation with clinico‐pathological characteristics and identify predicted target genes of the dysregulated miRNAs. Using real‐time quantitative reverse transcription‐polymerase chain reaction (qRT‐PCR), profiling of miRNA expression was performed in 30 EECs and 22 normal counterparts in which genome‐wide gene expression had been previously profiled and reported. Clustering analysis identified 30 miRNAs which were significantly dysregulated in EEC. The expression of a sub‐group of miRNAs was significantly correlated with clinico‐pathological characteristics including stage, myometrial invasion, recurrence and lymph node involvement. By searching for predicted miRNA targets that were linked to the dysregulated genes previously identified, 68 genes were predicted as candidate targets of these 30 dysregulated miRNAs. miR‐205 was significantly overexpressed in EECs compared with normal controls. After transfection of a miR‐205 inhibitor, the expression of miR‐205 in endometrial cancer cell line RL95‐2 cells decreased whereas its predicted target gene, JPH4, showed increased protein expression. JPH4 seems to be a real miR‐205 target in vitro and in vivo, and a candidate tumor suppressor gene in EEC. Based on this study in EEC, miRNAs predicted to be involved in tumorigenesis and tumor progression have been identified and placed in the context of the transcriptome of EEC. This work provides a framework on which further research into novel diagnosis and treatment of EEC can be focused. © 2008 Wiley‐Liss, Inc.

Recent developments in phenomenography have created some confusion because their links with the research tradition is not immediately obvious. This paper argues that an interest in variation is the thread that runs through the phenomenographic movement. To understand how the 'new phenomenography' emerged, we must recognise the different senses of variation that have drawn attention at different times. Phenomenography set out to reveal the different ways in which people experience the same phenomena. This 'first face of variation' refers to the variation in ways of seeing something, as experienced and described by the researchers. New phenomenography shifts the primary focus from methodological to theoretical questions, and characterises a way of experiencing something in terms of the critical aspects of the phenomenon as discerned by the learners. However, learners can only discern a particular aspect when they experience variation in that aspect. This is the 'second face of variation', which is experienced by the learners but described by the researchers.

The lesson study approach is a systematic process for producing professional knowledge about teaching by teachers, and has spread rapidly and extensively in the United States. The learning study approach is essentially a kind of lesson study with an explicit learning theory-the variation theory of learning. In this paper, we argue that having an explicit learning theory adds value to lesson study, as the variation theory of learning serves as a source of guiding principles for the teachers when they engage in pedagogical design, lesson analysis and evaluation. Through the use of two Hong Kong learning study cases, one from each of the two major ways of conducting learning study, we demonstrate the power of variation theory in explaining and predicting the relationship between what has taken place in the classroom and what the learners learn, and subsequently identifying ways to improve student learning through promoting teacher professional learning in a learning study setting.

A significant proportion of women changed their preferred mode of delivery after their first childbirth. Apart from reducing the number of cesarean sections in nulliparous women, prompt provision of education to women who had complications and investigations into fear factors during vaginal birth might help in reducing women's wish to change to elective cesarean section.

Objectives To construct new reference charts and equations for fetal biometry in the Hong

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Objective To establish whether women's preference for elective caesarean section (ELCS) changes as gestation advances.Design A prospective longitudinal observational study.Setting Two units providing obstetric care in Hong Kong, one public and one private.Sample Five hundred and one nulliparous Chinese pregnant women attending their routine fetal anomaly scan in either unit.Methods Consented subjects had two interviews using a structured questionnaire at 18-22 weeks and 35-37 weeks of gestation, respectively. Multivariate analysis was performed to identify determinants for preferring ELCS at the two gestational ages.Main outcome measure The preferences for the mode of delivery at the two gestational ages.Results The prevalence of maternal preference for ELCS in the study cohort was 17.2% (95% CI 13.9-20.5) and 12.7% (95% CI 9.6-15.8) at mid-trimester and at term, respectively. Significantly more women who preferred ELCS at mid-trimester changed to a trial of vaginal delivery (VD) at term than vice versa (42.0 versus 3.8%). The partner's preference for ELCS was a significant determinant for women preferring ELCS throughout the antenatal period. Among the women booked in the public sector, more women who preferred ELCS at term changed to deliver in private hospitals than those who preferred VD (46.2 versus 9.7%).Conclusions Many women changed from preferring ELCS to preferring VD as their pregnancy approached term. The partner's preference was a significant determinant for the women's choice. If a decrease in the proportion of women preferring ELCS is desired, the intervention programme should target the women and their partners who hold such a preference at 20 weeks.