Physical activity profiles and selected muscular fitness variables in English schoolchildren: A north–south divide?

The aim of the study was to compare and contrast habitual physical activity (PA) profiles and muscular fitness in schoolchildren from northern and southern regions of England. Data were collected from two secondary schools in the north east (NE) of England. The study procedures followed methods employed by the East of England Healthy Hearts Study in 10–16-year-old boys and girls based in the south east (SE) region of England and data were compared. Habitual physical activity (PAQ-A), vertical jump test, and hand-grip (HG) strength were assessed. We converted raw scores from all assessments to age- and sex-normalised z-scores. We recruited 597 children (58% boys) in the NE and compared findings to 597 age- and sex-matched boys and girls from the SE. Boys in the SE had significantly stronger HG scores, jumped higher, were more powerful (mean peak power: 2131?W vs. 1782?W; P?P?P?相似文献   

水分胁迫下亚精胺对小麦幼苗蛋白质含量与蛋白酶活性的影响

研究了水分胁迫下亚精胺对小麦幼苗相对含水量、叶绿素总量、蛋白质含量和蛋白酶活性的影响。结果显示,亚精胺预处理延缓水分胁迫下小麦幼苗叶片含水量、叶绿素含量和蛋白质含量的下降,抑制蛋白酶活性的上升。表明亚精胺预处理对水分胁迫的小麦幼苗具有防衰抗旱的保护作用。     

提高中学德育有效性的心理学思考--寻求道德教育的合理支点

中学道德教育是师生双向行动过程,教育者对学生的影响,包括学校对学生提出的要求、内容,采取的方式方法等,要符合学生的心理活动规律和发展水平,从而促进其发展,提高教育的实效性。     

浅论物理概念的分类及其教学策略

正确理解物理概念对于学生学习物理学科有着重要意义，科学而有效的物理教学方法应当重视学生心理活动的分析、解释与控制，并与学生的认知活动相符合。本文探讨了物理概念的分类及其特性，并从教育心理研究的角度提出物理概念教学的基本策略。     

学科活动·单元主题活动·方案教学

在幼儿园教育改革过程中,许多幼儿园疲于追赶时代潮流,从学科活动到单元主题活动,再到热极一时的方案教学,变到最后却发现教育质量并没有得到多少提高.其中的症结是什么?本文在分析了学科活动、单元主题活动和方案教学的基础上,指出三者之间不再是泾渭分明,而是处于一种边缘状态,正在逐渐走向融合.幼儿园教育改革的核心不是表面的教育活动形式选择,而是教师教育观念的深层变革.     

Synthetic and biological studies on a cyclopolypeptide of plant origin

Objective: A natural cyclic peptide previously isolated from Citrus medica was synthesized by coupling oftetrapep-tide units Boc-Leu-Pro-Trp-Leu-Ome and Boc-Ile-Ala-Ala-Gly-Ome after proper deprotection at carboxyl and amino terminals followed by cyclization of linear octapeptide segment.Methods: Solution phase technique was adopted for the synthesis of cyclooctapeptide--sarcodactylamide.Required tetrapeptide units were prepared by coupling of Boc-protected dipeptides viz.Boc-Leu-Pro-OH and Boc-Ile-Ala-OH with respective dipeptide methyl esters Trp-Leu-Ome and Ala-Gly-Ome.Cyclization of linear octapeptide unit was done by p-nitrophenyl ester method.The structure of synthesized cyclopolypeptide was elucidated by FTIR,1H NMR,13C NMR,FABMS spectral data and elemental analysis.The newly synthesized peptide was evaluated for dif-ferent pharmacological activities including antimicrobial,anthelmintic and cytotoxic activities.Results: Synthesis of sarcodac-tylamide was accomplished with >78% yield utilizing dicyclohexylcarbodiimide (DCC) as coupling agent.Newly synthesized peptide possessed potent cytotoxic activity against Dalton's lymphoma ascites (DLA) and Ehrlich's ascites carcinoma (EAC) cell lines,in addition to moderate anthelmintic activity against earthworms Megascoplex konkanensis,Pontoscotex corethruses and Eudrilus sp.Moreover,cyclopolypeptide displayed good antimicrobial activity against pathogenic fungi Candida albicans and Gram-negative bacteria Pseudomonas aeruginosa,in comparison to standard drugs griseofulvin and ciprofloxacin.Conclusion: Solution phase technique employing DCC and triethylamine (TEA) as base proved to be effective for the synthesis of natural cyclooctapeptide.N-methyl morpholine (NMM) was found to be a better base for the cyclization of linear octapeptide unit in comparison to TEA and pyridine.     

朱元璋驭宦之析

历代史家在谈及明太祖朱元璋严驭宦官时，皆赞誉有加，认为明代重用宦官源于成祖朱棣，与朱元璋毫无干系；其实不然，明代宦官擅权的祸根在太祖，朱棣不过是“萧作曹随”而已。宦官出使、监军、干预经济、刺臣民隐事监觞于洪武年间，它是封建君主专制制度的产物，并不以朱元璋个人意志为转移。     

电导法测定醋酸在H2O和THF混合溶剂中的活度系数

用电导法测定了醋酸在不同温度时和不同浓度下在H2O和THF混合溶剂中的电导丰，应用Debye-Hucker和OsagerFalkenhangen公式计算了醋酸在混合溶剂中的活度系数。并讨论了温度和浓度对电解质活度系数的影响。结果表明。电解质溶液的活度系数随着温度的增加而增大，随着浓度的增加而减小。     

烟草感染赤星病后几种酶的动态及其作用

对11个烤烟品种接种赤星病病原菌后,定期测定叶片的过氧化物酶(POD)同工酶、多酚氧化酶(PPO)、硝酸还原酶(NR)和抗坏血酸氧化酶活性,观察其变化规律．结果表明,相对抗赤星病强的品种,PPO活性上升;POD同工酶活性变幅大而快,接种初期活性稍有下降,然后增强,其中以阴极端2,4同工酶带增加较快,180 h由弱酶带变为强带;NR活性变化不大;抗坏血酸氧化酶活性提高．相反,抗赤星病弱的品种,PPO活性下降;POD同工酶变化不大,呈下降趋势;NR活性变幅大;抗坏血酸氧化酶在接种初期活性下降,84 h后回升．通过对不同品种的烟株接种赤星病菌后几种酶活性的测定,探察到一些抗病机理,也为进一步寻找筛选抗烟草赤星病的生化指标提供了参考．     

初中政治“活动课”的灵魂——目标、方式、与时俱进

要上好初中政治“活动课” ,教师必须树立正确灵活的教学理念 ,改变被动的教学方式 ,具备与时俱进的精神 ,为学生创造一个更为宽松有利的学习成长环境。