Microwave-assisted synthesis, anticonvulsant activity and quantum mechanical modelling of N-（4-bromo-3-methylphenyl） semicarbazones     

Shalini M  Yogeeswari P  Sriram D  Induja S 《Journal of Zhejiang University. Science. B》2007,8(1):45-55

Objective： To study the effect of halo substitution on disubstituted aryl semicarbazones on the anticonvulsant potential and model the activity based on quantum mechanics. Methods： A series of twenty-six compounds of N^4-（4-bromo-3-methylphenyl） semicarbazones were synthesized and evaluated for the anticonvulsant activity in the maximal electroshock seizure （MES） and subcutaneous pentylenetetrazole （scPTZ） seizure threshold tests. Some potential compounds were also tested in the subcutaneous strychnine （scSTY） and subcutaneous picrotoxin （scPIC） seizure threshold tests. The synthesized compounds were tested for behavioral impairment and CNS （central nervous system） depression in mice. Quantum mechanical modelling was carried out on these compounds to gain understanding on the structural features essential for activity. Results： Some compounds possessed broad spectrum anticonvulsant activity as indicated by their effect in pentylenetetrazole, strychnine, picrotoxin and maximal electroshock seizures models in resemblance to other aryl semicarbazone derivatives reported earlier. The higher the difference in HOMO （highest occupied molecular orbital） and LUMO （lowest unoccupied molecular orbital） energy levels was, the greater was the activity profile. Conclusion： The pharmacophoric requirements for compounds to exhibit anticonvulsant activity that includes one aryl unit in proximity to a hydrogen donor-acceptor domain and an electron donor have been justified with the molecular orbital surface analysis of the synthesized compounds.  相似文献   

Realms of the viruses online     

Liu D 《CBE life sciences education》2007,6(4):266-270

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Teaching human genetics with mustard: rapid cycling Brassica rapa (fast plants type) as a model for human genetics in the classroom laboratory     

Wendell DL  Pickard D 《CBE life sciences education》2007,6(2):179-185

We have developed experiments and materials to model human genetics using rapid cycling Brassica rapa, also known as Fast Plants. Because of their self-incompatibility for pollination and the genetic diversity within strains, B. rapa can serve as a relevant model for human genetics in teaching laboratory experiments. The experiment presented here is a paternity exclusion project in which a child is born with a known mother but two possible alleged fathers. Students use DNA markers (microsatellites) to perform paternity exclusion on these subjects. Realistic DNA marker analysis can be challenging to implement within the limitations of an instructional lab, but we have optimized the experimental methods to work in a teaching lab environment and to maximize the “hands-on” experience for the students. The genetic individuality of each B. rapa plant, revealed by analysis of polymorphic microsatellite markers, means that each time students perform this project, they obtain unique results that foster independent thinking in the process of data interpretation.  相似文献   

Teachers' education, classroom quality, and young children's academic skills: results from seven studies of preschool programs   总被引：10，自引：0，他引：10  

Early DM  Maxwell KL  Burchinal M  Alva S  Bender RH  Bryant D  Cai K  Clifford RM  Ebanks C  Griffin JA  Henry GT  Howes C  Iriondo-Perez J  Jeon HJ  Mashburn AJ  Peisner-Feinberg E  Pianta RC  Vandergrift N  Zill N 《Child development》2007,78(2):558-580

In an effort to provide high-quality preschool education, policymakers are increasingly requiring public preschool teachers to have at least a Bachelor's degree, preferably in early childhood education. Seven major studies of early care and education were used to predict classroom quality and children's academic outcomes from the educational attainment and major of teachers of 4-year-olds. The findings indicate largely null or contradictory associations, indicating that policies focused solely on increasing teachers' education will not suffice for improving classroom quality or maximizing children's academic gains. Instead, raising the effectiveness of early childhood education likely will require a broad range of professional development activities and supports targeted toward teachers' interactions with children.  相似文献   

To lie or not to lie: to whom and under what circumstances     

Perkins SA  Turiel E 《Child development》2007,78(2):609-621

This research examined adolescents' judgments about lying to circumvent directives from parents or friends in the moral, personal, and prudential domains. One hundred and twenty-eight adolescents (12.1-17.3 years) were presented with situations in which an adolescent avoids a directive through deception. The majority of adolescents judged some acts as acceptable, including deception regarding parental directives to engage in moral violations and to restrict personal activities. Other acts of deception were judged as unacceptable, including deception of parents regarding prudential acts, as well as deception of friends in each domain. In addition, lying to conceal a misdeed was negatively evaluated. Most adolescents thought that directives from parents and friends to engage in moral violations or to restrict personal acts were not legitimate, whereas parental directives concerning prudential acts were seen as legitimate. Results indicate that adolescents value honesty, but sometimes subordinate it to moral and personal concerns in relationships of inequality.  相似文献   

Longitudinal study of preadolescent sport self-concept and performance: reciprocal effects and causal ordering     

Marsh HW  Gerlach E  Trautwein U  Lüdtke O  Brettschneider WD 《Child development》2007,78(6):1640-1656

Do preadolescent sport self-concepts influence subsequent sport performance? Longitudinal data (Grades 3, 4, and 6) for young boys and girls (N= 1,135; mean age = 9.67) were used to test reciprocal effects model (REM) predictions that sport self-concept is both a cause and a consequence of sport accomplishments. Controlling prior sport performance (performance-based measures and teacher assessments), prior sport self-concept had positive effects on subsequent sport performance in both Grade 4 and Grade 6 and for both boys and girls. Coupled with previous REM studies of adolescents in the academic domain, this first test for preadolescents in the sport domain supports the generalizability of REM predictions over gender, self-concept domain, preadolescent ages, and the transition from primary to secondary school.  相似文献   

Marital conflict and conduct problems in Children of Twins   总被引：3，自引：0，他引：3  

Harden KP  Turkheimer E  Emery RE  D'Onofrio BM  Slutske WS  Heath AC  Martin NG 《Child development》2007,78(1):1-18

The Children-of-Twins design was used to test whether associations between marital conflict frequency and conduct problems can be replicated within the children of discordant twin pairs. A sample of 2,051 children (age 14-39 years) of 1,045 twins was used to estimate the genetic and environmental influences on marital conflict and determine whether genetic or environmental selection processes underlie the observed association between marital conflict and conduct problems. Results indicate that genetic and nonshared environmental factors influence the risk of marital conflict. Furthermore, genetic influences mediated the association between marital conflict frequency and conduct problems. These results highlight the need for quasiexperimental designs in investigations of intergenerational associations.  相似文献   

Processes of language acquisition in children with autism: evidence from preferential looking     

Swensen LD  Kelley E  Fein D  Naigles LR 《Child development》2007,78(2):542-557

Two language acquisition processes (comprehension preceding production of word order, the noun bias) were examined in 2- and 3-year-old children (n=10) with autistic spectrum disorder and in typically developing 21-month-olds (n=13). Intermodal preferential looking was used to assess comprehension of subject-verb-object word order and the tendency to map novel words onto objects rather than actions. Spontaneous speech samples were also collected. Results demonstrated significant comprehension of word order in both groups well before production. Moreover, children in both groups consistently showed the noun bias. Comprehension preceding production and the noun bias appear to be robust processes of language acquisition, observable in both typical and language-impaired populations.  相似文献   

Locus and nature of perceptual phonological deficit in Spanish children with reading disabilities     

Ortiz R  Jiménez JE  García Miranda E  Guzmán Rosquete R  Hernández-Valle I  Rodrigo M  Estévez A  Díaz A  Hernández Expósito S 《Journal of learning disabilities》2007,40(1):80-92

The aims of this study were (a) to determine whether Spanish children with reading disabilities (RD) show a speech perception deficit and (b) to explore the locus and nature of this perceptive deficit. A group of 29 children with RD, 41 chronological age-matched controls, and 27 reading ability-matched younger controls were tested on tasks of speech perception. The effect of linguistic unit (word vs. syllable) and type of phonetic contrast (voicing, place and manner of articulation) were analyzed in terms of the number of errors and the response time. The results revealed a speech perception deficit in Spanish children with RD that was independent of the type of phonetic contrast and of linguistic unit.  相似文献   

Developing mathematical proficiency in the Australian context: implications for students with learning difficulties     

Evans D 《Journal of learning disabilities》2007,40(5):420-426

The teaching of mathematics in Australian schools has received considerable attention over the past decade. States and territories have designed and implemented new mathematics syllabi, and education sectors have supported teachers through sustained professional learning initiatives. Whereas the major focus of these initiatives has been on students constructing mathematical knowledge from a range of learning activities and quality instruction, the education of students with difficulties in learning mathematics has been given little direct attention. This analysis of current syllabus developments and professional learning initiatives highlights the risk of exposing students with learning difficulties to fragile program designs and classroom instruction. The research literature is also examined to propose ways in which these fragilities can be addressed.  相似文献