Polymorphonuclear leukocytic sialic acid and sialidase activity in obesity

The level of sialic acid in the obese polymorphonuclear leukocytes (PMNL) was found to be significantly reduced as compared to normal. Activity of sialic acid degrading enzyme, sialidase, was found to be increased in the obese state. Restoration in both sialic acid content and sialidase activity was also evidenced in the PMNL of treated obese patients.     

注意:概念、测验和教师等级评定

本文的理论部分探讨注意的性质、注意的测验和测量，以及注意缺陷的鉴定。注意具有选择性，它包含着对冲动反应的抑制和对分心的克服。第二部分讨论三项经验研究，这些研究探索了注意等级评定量表的使用，该量表由教师对儿童在课堂情境下的注意情况进行等级评定。研究发现，教师的等级评定可以预测课外情境中儿童在注意测验上的表现。这些等级评定具有显著的预测性，正如该测验的结果所表明的，教师一直关注着儿童注意的一个重要方面，即对分心的抵制。在结论性评述中，讨论了可能导向注意缺陷改善的动态测试。第三部分是附录部分，例举了若干注意力测验。     

Behavioural inhibition and hyperactivity: a commentary from alternative perspectives

Attention disorders in the school population include attention deficit, hyperactivity and conduct disorders. A key concept for distinguishing hyperactive from attention disorders is behavioural inhibition as advocated by Barkley, a prominent American researcher. However, the concept itself needs to be understood because, as argued in this paper, there are two kinds of inhibition: Pavlov's original concept and the American one. These should be differentiated if the abnormal conditions associated with attention and hyperactivity are to be rationally connected to cognitive characteristics, rather than to be solely based on clinical symptoms and behavioural ratings. We suggest a consensus on the concept of inhibition and a unified view of attention disorders integrating cognitive and behavioural manifestations. Finally, the importance of basing remediation on a theoretically supported and rationally derived set of cognitive training tasks for the amelioration of inattention and hyperactivity is offered.     

Assessment of attention in school children: teachers' ratings related to tests of attention

The paper provides (1) a teacher-administered rating instrument for inattention without confounding the rating with hyperactivity and conduct disorder, and (2) evidence that the ratings correlate with the scores obtained from cognitive tests of attention. In Study I, the first objective was to investigate the construct validity and the inter-rater reliability of the Attention Checklist (ACL) by factor analysing the teacher ratings of 110 Grade 4 children, obtained by using the ACL. The second objective was to investigate the predictive validity of the ACL by examining the relationship between the scores obtained for the participants from teachers' ratings using the ACL and the scores obtained by participants in the lab-type attention tests. The results of factor analysis showed that a single factor labelled ‘inattention’ underlies the 12 items in the ACL. Examining the differences in performance on attention tests, the ‘low attention’ children as rated by the teachers on the ACL scored lower than the ‘high attention’ children on the objective tests of attention. These findings were replicated in Study II, which was conducted to test further the construct validity and predictive validity of the ACL. This time, only those two tests (Auditory Attention and Visual Attention) that had shown relatively poor discrimination between the high and low attention groups in Study I were, again, administered to another cohort of 97 Grade 4 children, as it was our intention to further challenge the reliability of the ACL. Overall, the results of both studies suggest that comprehensive assessment of attention skills should include both ACL and objective measures of selective attention.     

UNIVERSITY‐BASED ADULT DAY CARE CENTER FOR RESEARCH AND TRAINING: DESIGN,FUNDING, AND PROGRAMMATIC ISSUES

In the early 1980s, the College of Human Resources at Virginia Polytechnic Institute and State University began a visioning process to plan its educational agenda for the 21st century. One of the more pressing issues targeted for educational intervention was community‐based long‐term care. Ten years later, a licensed, Medicaid‐certified adult day health center is fully operational on the university campus, providing a myriad of research, teaching, and public service opportunities for faculty and students. Center design, funding, and programmatic issues are discussed.     

An exploration of primary school teachers' understanding of art and the place of art in the primary school curriculum

Some research within developmental psychology shows a slow period of development in children's expressive drawings during the primary school years. Developmental researchers suggest that ‘educational factors’ could contribute to this dip in development but have not explored these factors. This study explores links between educational policy – in terms of the English National Curriculum – and the development of expression in child art. A Foucauldian style analysis of interviews is presented which investigates how ten primary school teachers working in two Staffordshire schools approach art. A specific concern is to explore how different understandings of art and teaching practices are shaped and managed by the curriculum. This allows links between the demands of the curriculum and the observed dip in expressive drawing development to be investigated.     

Plate Tectonics and Europa’s Icy Shell

A unique attribute of Earth is the presence of plate tectonics. Not only does it give rise to continents, mountain chains, and ocean basins but also promotes a high level of biodiversity. It is the reason for the formation of the so-called ‘Pacific Ring of Fire’ – a belt of intense volcanic activity and a large number of earthquakes surrounding the Pacific ocean. But what drives the plate motion? Did Earth always have plate tectonics? These are some fascinating geoscientific questions. In trying to answer these questions, an effort is made to impress upon the reader the vast ocean of uncertainty, and hence the opportunity, in the field of Earth and Planetary Sciences. To make it more engaging, the article provides a peek into the long process which culminated in the present-day theory of plate tectonics on Earth. While the first half of the article focuses on subduction and its cause, the second half summarizes a recent finding made on the surface of Europa. In view of readability across disciplines, the complex subject details are kept to bare minimum.     

Toxic effects of Litsea elliptica Blume essential oil on red blood cells of Sprague-Dawley rats

Litsea elliptica Blume leaves have been traditionally used as medicinal herbs because of its antimutagenicity, che-mopreventative and insecticidal properties. In this study, the toxic effects of L. elliptica essential oil against Sprague-Dawley rat's red blood cells (RBCs) were evaluated. L. elliptica essential oil was given by oral gavage 5 times per week for 3 treated groups in the doses of 125, 250, and 500 mg/(kg body weight), respectively, and the control group received distilled water. Full blood count, RBC osmotic fragility, RBC morphological changes, and RBC membrane lipid were analyzed 28 d after the treatment. Although L. elliptica essential oil administration had significantly different effects on hemoglobin (Hb), mean cell hemoglobin concentration (MCHC), mean cell volume (MCV), and mean cell hemoglobin (MCH) in the experimental groups as compared to the control group (P<0.05), the values were still within the normal range. L. elliptica induced morphological changes of RBC into the form of echinoeyte. The percentage of echinocyte increased significantly among the treated groups in a dose-response manner (P<0.001). The concentrations of RBC membrane phospholipids and cholesterol of all treated groups were significantly lower than those of control group (P<0.001). However, the RBC membrane osmotic fragility and total proteins of RBC membrane findings did not differ significantly between control and treated groups (P>0.05). It is concluded that structural changes in the RBC membrane due to L. elliptica essential oil administration did not cause severe membrane damage.     

Epigallocatechin-3-gallate affects the growth of LNCaP cells via membrane fluidity and distribution of cellular zinc

Objective: To evaluate effects of epigallocatechin-3-gallate (EGCG) on the viability, membrane properties, and zinc distribution, with and without the presence of Zn2+, in human prostate carcinoma LNCaP cells. Methods: We examined changes in cellular morphology and membrane fluidity of LNCaP cells, distribution of cellular zinc, and the incorporated portion of EGCG after treatments with EGCG, Zn2+, and EGCG+Zn2+. Results: We observed an alteration in cellular morphology and a decrease in membrane fluidity of LNCaP cells after treatment with EGCG or Zn2+. The proportion of EGCG incorporated into liposomes treated with the mixture of EGCG and Zn2+ at the ratio of 1:l was 90.57%, which was significantly higher than that treated with EGCG alone (30.33%). Electron spin resonance (ESR) studies and determination of fatty acids showed that the effects of EGCG on the membrane fluidity of LNCaP were decreased by Zn2+. EGCG accelerated the accumulation of zinc in the mitochondria and cytosol as observed by atomic absorption spectrometer. Conclusion: These results show that EGCG interacted with cell membrane,decreased the membrane fluidity of LNCaP cells, and accelerated zinc accumulation in the mitochondria and cytosol, which could be the mechanism by which EGCG inhibits proliferation of LNCaP cells. In addition, high concentrations of Zn2+ could attenuate the actions elicited by EGCG.     

Perspective: Flicking with flow: Can microfluidics revolutionize the cancer research?

According to the World Health Organization, cancer is one of the leading causes of death worldwide. Cancer research, in its all facets, is truly interdisciplinary in nature, cutting across the fields of fundamental and applied sciences, as well as biomedical engineering. In recent years, microfluidics has been applied successfully in cancer research. There remain, however, many elusive features of this disease, where microfluidic systems could throw new lights. In addition, some inherent features of microfluidic systems remain unexploited in cancer research. In this article, we first briefly review the advancement of microfluidics in cancer biology. We then describe the biophysical aspects of cancer and outline how microfluidic system could be useful in developing a deeper understanding on the underlying mechanisms. We next illustrate the effects of the confined environment of microchannel on cellular dynamics and argue that the tissue microconfinement could be a crucial facet in tumor development. Lastly, we attempt to highlight some of the most important problems in cancer biology, to inspire next level of microfluidic applications in cancer research.