基于“学”的活动如何设计——也谈《种树郭橐驼传》的难点确定与突破

阅读教学的主体始终是学生,只有通过基于“学”的活动设计方能落实这一理念,真正促进学生发展。基于“学”的活动设计,需要确定核心内容,逆推教学环节,明晰教学落点,重视语言品读。《种树郭橐驼传》一课教学,从理解“橐驼”讲理这一难点出发,设计出环环相扣、由浅入深的教学活动。

“学”的活动:找准学习过程的有效支点——以《认识圆柱》为例

"学"的活动,意指能帮助学生学习的有目的、有计划组织的有关学习的活动。支点,在教学中是指实现真正学习、高效学习的关键点、中心点。有效的"学"的活动,是找准学习过程的有效支点。本文以《认识圆柱》一课为例,通过课始"制作名片"活动,找准认知起点,收集有关圆柱的前概念;课中"玩转圆柱",立足深度探究,建立有关圆柱的表象;课尾"创造圆柱"活动,促进整体建构,建立有关圆柱的认知结构,从而丰富学生学习圆柱的过程。

THE HYDROLOGICAL EFFECT UNDER HUMAN ACTIVITIESIN THE INLAND WATERSHEDS OF XINJIANG, CHINA

Natural environment, inland water distribution and water circulation has been changed greatly affected by human activities in Xinjiang, China. Human activities developed quickly in the inland watersheds in Xinjiang after 1950. More than 50% of river water is drawn into irrigation area, and all water in parts of little river is drawn to canal or reservoirs. However, there is evident hydrological effect caused by human activities. 1) water distribution in arid land has changed. A lot of river water is drawn into oasis and water table inside of oasis has risen but declined out of oasis. However, water table has declined in some cities because of over pumping for groundwater. 2) Stream process has changed after water drawing and drainage for irrigation. Runoff in the lower reaches of river has generally decreased, and the lower reaches of some rivers are even disappeared for stream. 3) Large watersheds have been divided into several small watersheds. In some tributaries, most of the river water has drawn to irrigation area so that stream in the lower reaches has disappeared for years. 4) Evaporation at oasis has increased from 50–200mm/a to 800–1300mm/a after reclamation. But it decreased to 50mm/a or less out of oasis. Some lakes have reduced or dried. Water-system with canals and reservoirs has appeared in the oases. 5) Water quality of inland rivers and lakes has generally deteriorated because it accepts drainage water from farmland and factories. 6) Effective scale of human activities on hydrological process in arid land has expanded from separate rivers to all watersheds; from surface water to groundwater; from drought season to flood season; and from single year to several years. Scale of the effect of human activities to hydrological process is going larger and larger. Along with the effective usage of water resources in the inland watershed in Xinjiang, the hydrological effect of human activities will be mainly change to: 1) river in pain area will be canalized; 2) stream process will be controlled by human being; 3) lakes in plain area will degenerate; 4) water will be salty in the lower reaches of river. However, hydrological conditions in Xinjiang will be better to water using and to natural environment.

Relevance of proteolysis and proteasome activation in fatty liver graft preservation: An Institut Georges Lopez-1 vs University of Wisconsin appraisal

To compare liver proteolysis and proteasome activation in steatotic liver grafts conserved in University of Wisconsin (UW) and Institut Georges Lopez-1 (IGL-1) solutions.METHODSFatty liver grafts from male obese Zücker rats were conserved in UW and IGL-1 solutions for 24 h at 4 °Cand subjected to “ex vivo” normo-thermic perfusion (2 h; 37 °C). Liver proteolysis in tissue specimens and perfusate was measured by reverse-phase high performance liquid chromatography. Total free amino acid release was correlated with the activation of the ubiquitin proteasome system (UPS: measured as chymotryptic-like activity and 20S and 19S proteasome), the prevention of liver injury (transaminases), mitochondrial injury (confocal microscopy) and inflammation markers (TNF 1 alpha, high mobility group box-1 (HGMB-1) and PPAR gamma), and liver apoptosis (TUNEL assay, cytochrome c and caspase 3).RESULTSProfiles of free AA (alanine, proline, leucine, isoleucine, methionine, lysine, ornithine, and threonine, among others) were similar for tissue and reperfusion effluent. In all cases, the IGL-1 solution showed a significantly higher prevention of proteolysis than UW (P < 0.05) after cold ischemia reperfusion. Livers conserved in IGL-1 presented more effective prevention of ATP-breakdown and more inhibition of UPS activity (measured as chymotryptic-like activity). In addition, the prevention of liver proteolysis and UPS activation correlated with the prevention of liver injury (AST/ALT) and mitochondrial damage (revealed by confocal microscopy findings) as well as with the prevention of inflammatory markers (TNF1alpha and HMGB) after reperfusion. In addition, the liver grafts preserved in IGL-1 showed a significant decrease in liver apoptosis, as shown by TUNEL assay and the reduction of cytochrome c, caspase 3 and P62 levels.CONCLUSIONOur comparison of these two preservation solutions suggests that IGL-1 helps to prevent ATP breakdown more effectively than UW and subsequently achieves a higher UPS inhibition and reduced liver proteolysis.

Adapting the usage of enzyme unit to its definition

The enzyme unit U, by its definition, is the amount of enzyme that catalyses the transformation o f one micromole of substrate per minute under standard assay conditions. However, in practical use, it is identical with micromole or microgram per minute, which deviates from the essence of the definition as a measure of amount of substance. Such usage appears in many publications that involve enzyme kinetics and conveys obscure signification. In this article, we solved the confusion by regarding the unit U as a measure of amount of enzyme having a specified catalytic activity just like the basic SI unit mole （symbol tool） defined as the amount of substance of a system which contains as many elementary entities as there are atoms in 0.012 kg of carbon 12. We introduced the concept of unit rate, ru, which is defined as the rate of a reaction mediated by 1 U enzyme, in calculating the enzyme units in an amount of enzyme so as to avoid the inconsistence of the expression with the definition of enzyme unit. The method can also be applied to the case of katal, the recommended SI unit of enzyme activity.

Modified DIX model for ion-exchange equilibrium of L-phenylalanine on a strong cation-exchange resin

L-phenylalanine, one of the nine essential amino acids for the human body, is extensively used as an ingredient in food, pharmaceutical and nutrition industries. A suitable equilibrium model is required for purification of L-phenylalanine based on ion-exchange chromatography. In this work, the equilibrium uptake of L-phenylalanine on a strong acid-cation exchanger SH11 was investigated experimentally and theoretically. A modified Donnan ion-exchange （DIX） model, which takes the activiW into account, was established to predict the uptake of L-phenylalanine at various solution pH values. The model parameters including selectivity and mean activity coefficient in the resin phase are presented. The modified DIX model is in good agreement with the experimental data. The optimum operating pH value of 2.0, with the highest t-phenylalanine uptake on the resin, is predicted by the model. This basic information combined with the general mass transfer model will lay the foundation for the prediction of dynamic behavior of fixed bed separation process.

On Mechanisms of Human Behavior： The ＂Mind Blindness Phenomenon＂ in Philosophy, Religion, Science, and Medicine

The phenomenon described here has no scientific title, but occurs frequently in daily living, from science to philosophy, religion, and medicine. In every field of human endeavor, when a view is expressed, sharp and profound differences of opinion ensue. Initially, we coin this phenomenon as ＂understanding blindness＂ or ＂mind＇s awareness.＂ Thereafter, we decide to refer to it as ＂mind blindness,＂ a concept introduced to science by Professor Simon Baron-Cohen, who coins it for a cognitive disorder associated with autism, Asperger＇s syndrome, and schizophrenia. Baron-Cohen＇s usage has subsequently been extended to dementia, bi-polar disorders, antisocial personality disorders, and even normal aging. In our view, definition and identification of ＂mind blindness＂ in philosophy, religion, science, medicine, and at end-of-life care can help mankind to better understand mechanisms of human behavior, and the causes of conflicts, controversies, contradictions, and sharp differences of opinion in human life, and even to solve some of them.

THE IMPLEMENTATION OF A BALANCED READING INSTRUCTION IN TAIWAN

The purpose of this study is to explore the effects of the balanced reading program on the elementary school students in Taiwan. The participants were 36 fifth graders in Taiwan. The researchers chose suitable picture books as teaching materials and made use of them to design a balanced reading program. The program combines the ideas of whole language and phonics rules. Whole-part-whole structure was used in the teaching process. The teaching of the balanced reading program lasted for nine weeks. The questionnaire of learning feedbacks, the questionnaire of reading activities, the teacher's journal, interviews with teachers and students were used to gather data. Six facts were found after the analysis of the data: (1) Among the picture books, 'Seven Blind Mice' and 'Snow' were chosen by the students as their favorite. (2) Most students liked the reading activities for this semester. (3) The students made progress in reading ability and reading techniques. (4) The frequency of the students' reading English storybooks increased. (5) Most students were willing to read English storybooks after the program. (6) The table of self-evaluation didn't work well. Some suggestions have been provided according to the findings.