Developmental characteristics and response to iron toxicity of root border cells in rice seedlings

To investigate the Fe2 effects on root tips in rice plant, experiments were carded out using border cells in vitro. The border cells were pre-planted in aeroponic culture and detached from root tips. Most border cells have a long elliptical shape. The number and the viability of border cells in situ reached the maxima of 1600 and 97.5%, respectively, at 20～25 mm root length. This mortality was more pronounced at the first 1～12 h exposure to 250 mg/L Fe2 than at the last 12～36 h. After 36 h, the cell viability exposed to 250 mg/L Fe2 decreased to nought, whereas it was 46.5% at 0 mg/L Fe2 . Increased Fe2 dosage stimulated the death of detached border cells from rice cultivars. After 4 h Fe2 treatment, the cell viabilities were≥80% at 0 and 50 mg/L Fe2 treatment and were <62% at 150, 250 and 350 mg/L Fe2 treatment; The viability of border cells decreased by 10% when the Fe2 concentration increased by 100 mg/L. After 24 h Fe2 treatment, the viabilities of border cells at all the Fe2 levels were <65%; The viability of border cells decreased by 20% when the Fe2 concentration increased by 100 mg/L. The decreased viabilities of border cells indicated that Fe2 dosage and treatment time would cause deadly effect on the border cells. The increased cell death could protect the root tips from toxic harm. Therefore, it may protect root from the damage caused by harmful iron toxicity.     

Children's social and scholastic lives in kindergarten: related spheres of influence?

Evidence from two studies conducted with kindergarten samples (N = 200, M age = 5.58 years; N = 199, M age = 5.47 years) supported a series of interrelated hypotheses derived from a child x environment model of early school adjustment. The findings obtained were consistent with the following inferences: (1) Entry factors, such as children's cognitive maturity and family backgrounds, directly as well as indirectly influence children's behavior, participation, and achievement in kindergarten; (2) as children enter school, their initial behavioral orientations influence the types of relationships they form with peers and teachers; (3) stressful aspects of children's peer and teacher relationships in the school environment adversely impact classroom participation and achievement; and (4) classroom participation is an important prerequisite for achievement during kindergarten. Collectively, these findings illustrate the need to revise prevailing theories of school adjustment, and the research agendas that evolve from these perspectives, so as to incorporate interpersonal risk factors that operate within the school environment.     

Development of an indirect competitive ELISA for simultaneous detection of enrofloxacin and ciprofloxacin

Modified 1-ethyl-3-(3-dimethylaminopropy) carbodiimide (EDC) method was employed to synthesize the artificial antigen of enrofloxacin (ENR), and New Zealand rabbits were used to produce anti-ENR polyclonal antibody (pAb). Based on the checkerboard titration, an indirect competitive enzyme-linked immunosorbent assay (ELISA) standard curve was established. This assay was sensitive and had a linear range from 0.6 to 148.0 μg/kg (R ²=0.9567), with the half maximal inhibitory concentration (IC₅₀) and limit of detection (LOD) values of 9.4 μg/kg and 0.2 μg/kg, respectively. Of all the competitive analogues, the produced pAb exhibited a high cross-reactivity to ciprofloxacin (CIP) (87%), the main metabolite of ENR in tissues. After optimization, the matrix effects can be ignored using a 10-fold dilution in beef and 20-fold dilution in pork. The overall recoveries and coefficients of variation (CVs) were in the ranges of 86%–109% and 6.8%–13.1%, respectively. It can be concluded that the established ELISA method is suitable for simultaneous detection of ENR and CIP in animal tissues.     

Inflammatory bowel disease unclassified

Objective  

Inflammatory bowel diseases (IBDs) are idiopathic, chronic, and inflammatory intestinal disorders. The two main types, ulcerative colitis (UC) and Crohn’s disease (CD), sometimes mimic each other and are not readily distinguishable. The purpose of this study was to present a series of hospitalized cases, which could not initially be classified as a subtype of IBD, and to try to note roles of the terms indeterminate colitis (IC) and inflammatory bowel disease unclassified (IBDU) when such a dilemma arises.     

Development of a supported self-directed learning approach for anatomy education

The ability to deliver sufficient core anatomical knowledge and understanding to medical students with limited time and resources remains a major challenge for anatomy educators. Here, we report the results of switching from a primarily didactic method of teaching to supported self-directed learning for students studying anatomy as part of undergraduate medicine at the University of Edinburgh. The supported self-directed approach we have developed makes use of an integrated range of resources, including formal lectures and practical sessions (incorporating gross anatomy specimens, medical imaging technologies, anatomical models, clinical scenarios, and surface anatomy workstations). In practical sessions, students are provided with a custom-made workbook that guides them through each session, with academic staff, postgraduate tutors, and near-peer teaching assistants present to deal with misunderstandings and explain more complicated topics. This approach retains many of the best attributes of didactic teaching but blends them with the advantages associated with self-directed learning approaches. The switch to supported self-directed learning-initially introduced in 2005-resulted in a significant improvement in anatomy examination scores over the subsequent period of five years, manifesting as an increase in the average anatomy practical spot examination mark, less students failing to obtain the pass mark and more students passing with distinction. We conclude that the introduction of supported self-directed learning improved students' engagement, leading to deeper learning and better understanding and knowledge of anatomy.