溴氰菊酯对大鼠小脑皮质组织中HO和ATPase活性的影响

目的:研究溴氰菊酯(DM)对SD大鼠小脑皮质组织中血红素加氧酶(HO)的活性和ATPase活性的影响。方法:(1)成年雄性SD大鼠共40只,其中20只用于血红素加氧酶(HO)的活性的测定,另20只用于ATPase活力测定,均随机分为对照组和DM染毒实验组,实验组中大鼠72小时内给溴氰菊酯(1/20LD50)三次,对照组为相同剂量的玉米油,分别检测小脑皮质组织HO活性和ATPase活性。(2)成年雄性SD大鼠30只,同样方法取出小脑皮质,制成切片,随机分为对照组(相同剂量的玉米油)和5个不同浓度的DM染毒试验组(2×10-7mmol/L、2×10-6mmol/L、2×10-5mmol/L、2×10-4mmol/L、2×10-3mmol/L),测定ATPase活性。结果:整体染毒小脑皮层组织HO活性为对照组的240.39%(p﹤0.05),Na+,K+-ATPase活性为对照组的131.47%(p﹤0.05),Ca2+-ATPase活性增加没有统计学意义,Mg2+-ATPase有显著的抑制作用(P<0.05),为对照组的79.91%。体外试验发现只有达到10-3mmol/L数量级的DM对温育小脑皮质切片组织中的Mg2+-ATPase活性才有显著的抑制作用(P<0.05);且无论何种浓度均未发现上述体内染毒时对Na+,K+-ATPase活性的增加作用。结论:DM可增加大鼠小脑皮质的HO活性,体内体外染毒DM对三种ATPase活性的影响并不一致。     

On standardization of the Activity Index

Relative Specialization Index (RSI) was introduced as a simple transformation of the Activity Index (AI), the aim of this transformation being standardization of AI, and therefore more straightforward interpretation. RSI is believed to have values between −1 and 1, with −1 meaning no activity of the country (institution) in a certain scientific field, and 1 meaning that the country is only active in the given field. While it is obvious from the definition of RSI that it can never be 1, it is less obvious, and essentially unknown, that its upper limit can be quite far from 1, depending on the scientific field. This is a consequence of the fact that AI has different upper limits for different scientific fields. This means that comparisons of RSIs, or AIs, across fields can be misleading. We therefore believe that RSI should not be used at all. We also show how an appropriate standardization of AI can be achieved.     

“四元一体”教研活动模式的构建与创新

教研活动是教学重要组成部分,是教师成长的有效途径;论文分析了"四元一体"教研活动模式的内涵,探讨了"四元一体"教研活动模式的构建,为教研活动改革和组织老师开展各种教研活动提供了实际性帮助;同时,探讨了教研活动创新的几种形式,提出开展多元教研活动,实现教学与科研相互促进,从而提高教研活动的有效性,最终促进教师的专业成长,共同提高教学质量。     

Personal Activity Trackers and the Quantified Self

ABSTRACT

Personal activity trackers are an inexpensive and easy way for people to record their physical activity and simple biometric data. As these devices have increased in availability and sophistication, their use in daily life and in medicine has grown. This column will briefly explore what these devices are, what types of data they can track, and how that data can be used. It will also discuss potential problems with trackers and how librarians can help patients and physicians manage and protect activity data. A brief list of currently available activity trackers is also included.     

Supporting Teachers on Science‐focused School Trips: Towards an integrated framework of theory and practice

Although science centres and museums are important educational resources, school trips to these places are not often conducted in a manner that could maximise learning. In addressing this issue, a Framework for Museum Practice (FMP) is proposed, derived from the perspectives of Cultural Historical Activity Theory, theories of intrinsic motivation, and research into conceptual learning. It is hypothesised that this theoretically derived framework, if implemented by museum educators, can potentially lead to the creation of resources for teachers that would enable them to make better use of the learning opportunities afforded by school trips, and to maximise the impact on pupil learning, including their affective experience. This paper also describes how the framework was used to guide the development of resources to be used in conjunction with a science museum trip. The resources were tested by two primary school teachers and their classes, and the data were analysed for evidence of teacher and student behaviour consistent with the design principles in the FMP. Findings lend some empirical support for the FMP and suggest that it may offer a guide for the development of museum‐provided resources, which would have the potential to improve the utilisation by teachers of informal science institutions and, consequently, their impact on pupil learning.     

Analysing teachers' operations when teaching students: what constitutes scientific theories?

ABSTRACT

The aim of the study is to analyse teachers’ efforts to develop secondary school students’ knowledge and argumentation skills of what constitutes scientific theories. The analysis is based on Leontiev’s three-level structure of activity (activity, action, and operation), as these levels correspond to the questions why, what, and how content is taught. The unit of analysis was a school development project in science education, where design-based interventions were conducted. Data comprised notes and minutes from eight meetings, plans, and video recordings of the lessons, and a written teacher evaluation. The teachers’ (n = 7) learning actions were analysed to identify (a) concept formation in science education, (b) expressions of agency, (c) discursive manifestations of contradictions, and (d) patterns of interaction during the science interventions. Three lessons on what constitutes scientific theories were implemented in three different student groups (n = 24, 23, 24), framed by planning and evaluation meetings for each lesson. The results describe (1) the ways in which teachers became more skilled at ensuring instruction met their students’ needs and (2) the ways in which teachers’ operations during instruction changed as a result of their developed knowledge of how to express the content based on theoretical assumptions.     

Learning Through Computational Modeling

Summary

When thinking of reasoning, problem solving, communication, and connecting related ideas, the tool of choice in nearly every discipline is the microcomputer. Furthermore, unlike the traditional calculator, the modern classroom computer has an unparalleled ability to implement both graphical and procedural components of mathematics understanding in a single unified object. By students' creation and utilization of mathematically relevant computer-based objects, this dual encapsulation provides them with a unique opportunity to see both the form of representation and their actions utilizing this representation simultaneously.

This paper suggests that the object-oriented environments that modern technology enables are ideally suited to parallel and facilitate the ability of students to take a broader variety of action upon objectsof a nature and kind hitherto unknown. These student-controlled actionsupon these mathematically powerful and computer-enabled objectshave the potential for creating classroom environments that both surpass the pale hopes of the integrated learning system and surprise those wedded to a conservative view of Piagetian developmental levels.     

金属标准电极电位,电离势和活动顺序

在气相中,金属原子失去电子的难易用电离势数值大小来衡量,在水溶液中,金属原子失去电子能力的难易用电离热数值大小来衡量。本文从金属的标准电极电势,电离势分别讨论金属活动顺序。     

粉煤灰与大掺量粉煤灰混凝土

论述了粉煤灰在混凝土中的作用机理及粉煤灰对混凝土性能的改善,并结合本溪市的粉煤灰排放情况提出了推广和使用大掺量粉煤灰混凝土的优越性。     

目标控制训练法与射击训练

目标控制训练法是一种以明确的目标任务,引导、激发运动员的自觉性与能动性,达到培养和提高运动员综合能力的一种训练过程与方法。它运用了系统思想、控制论、管理学和运动心理学的许多原理,结合了我国射击训练的实践经验,经实践证实是一种切实可行具有活力与优势的射击训练方法。