化学致癌机制的系统科学方法思考

本文用系统科学方法分析了化学物致癌机制，化学致癌是一个长期的，多基因，多阶段，多病因过程已被公认，研究者们认为化学致癌系统由基因和非基因因素构成，在此系统中存在若干系统属性，如整体性，综合性，动态性等，医学研究者要在癌症病因，治疗和预防中取得的半功倍成效，就应该科学地运用致癌系统中的这些系统属性。     

Quantifying latent social motivation and its associations with joint attention and language in infants at high and low likelihood for autism spectrum disorder

Social motivation—the psychobiological predisposition for social orienting, seeking social contact, and maintaining social interaction—manifests in early infancy and is hypothesized to be foundational for social communication development in typical and atypical populations. However, the lack of infant social-motivation measures has hindered delineation of associations between infant social motivation, other early-arising social abilities such as joint attention, and language outcomes. To investigate how infant social motivation contributes to joint attention and language, this study utilizes a mixed longitudinal sample of 741 infants at high (HL = 515) and low (LL = 226) likelihood for ASD. Using moderated nonlinear factor analysis (MNLFA), we incorporated items from parent-report measures to establish a novel latent factor model of infant social motivation that exhibits measurement invariance by age, sex, and familial ASD likelihood. We then examined developmental associations between 6- and 12-month social motivation, joint attention at 12–15 months, and language at 24 months of age. On average, greater social-motivation growth from 6–12 months was associated with greater initiating joint attention (IJA) and trend-level increases in sophistication of responding to joint attention (RJA). IJA and RJA were both positively associated with 24-month language abilities. There were no additional associations between social motivation and future language in our path model. These findings substantiate a novel, theoretically driven approach to modeling social motivation and suggest a developmental cascade through which social motivation impacts other foundational skills. These findings have implications for the timing and nature of intervention targets to support social communication development in infancy.

Highlights

• We describe a novel, theoretically based model of infant social motivation wherein multiple parent-reported indicators contribute to a unitary latent social-motivation factor.
• Analyses revealed social-motivation factor scores exhibited measurement invariance for a longitudinal sample of infants at high and low familial ASD likelihood.
• Social-motivation growth from ages 6–12 months is associated with better 12−15-month joint attention abilities, which in turn are associated with greater 24-month language skills.
• Findings inform timing and targets of potential interventions to support healthy social communication in the first year of life.

     

团结奋进铸辉煌 同心同德谱新篇——热烈庆祝中华人民共和国成立六十周年

2009年10月的神州大地，普天同庆，万众欢腾。10月1日天安门广场上盛大的阅兵仪式，壮观的群众游行，美轮美奂的国庆之夜，那些画面已经定格在人们的心中，催生出无限的激情。“在这个喜庆而又庄严的时刻，全国各族人民都为伟大祖国的发展进步感到无比自豪，都对实现中华民族伟大复兴的光明前景充满信心。”