Adaptive Synaptogenesis Constructs Neural Codes That Benefit Discrimination

Intelligent organisms face a variety of tasks requiring the acquisition of expertise within a specific domain, including the ability to discriminate between a large number of similar patterns. From an energy-efficiency perspective, effective discrimination requires a prudent allocation of neural resources with more frequent patterns and their variants being represented with greater precision. In this work, we demonstrate a biologically plausible means of constructing a single-layer neural network that adaptively (i.e., without supervision) meets this criterion. Specifically, the adaptive algorithm includes synaptogenesis, synaptic shedding, and bi-directional synaptic weight modification to produce a network with outputs (i.e. neural codes) that represent input patterns proportional to the frequency of related patterns. In addition to pattern frequency, the correlational structure of the input environment also affects allocation of neural resources. The combined synaptic modification mechanisms provide an explanation of neuron allocation in the case of self-taught experts.     

Scientists Popularizing Science: Characteristics and Impact of TED Talk Presenters

The TED (Technology, Entertainment, Design) conference and associated website of recorded conference presentations (TED Talks) is a highly successful disseminator of science-related videos, claiming over a billion online views. Although hundreds of scientists have presented at TED, little information is available regarding the presenters, their academic credentials, and the impact of TED Talks on the general population. This article uses bibliometric and webometric techniques to gather data on the characteristics of TED presenters and videos and analyze the relationship between these characteristics and the subsequent impact of the videos. The results show that the presenters were predominately male and non-academics. Male-authored videos were more popular and more liked when viewed on YouTube. Videos by academic presenters were more commented on than videos by others and were more liked on YouTube, although there was little difference in how frequently they were viewed. The majority of academic presenters were senior faculty, males, from United States-based institutions, were visible online, and were cited more frequently than average for their field. However, giving a TED presentation appeared to have no impact on the number of citations subsequently received by an academic, suggesting that although TED popularizes research, it may not promote the work of scientists within the academic community.     

Bridging Multiple Worlds: How African American and Latino Youth in Academic Outreach Programs Navigate Math Pathways to College

Universities have launched outreach programs to enhance their ethnic diversity, yet little developmental research examines students' pathways to college. This study compares capital models (highlighting family background) with challenge models (highlighting students' challenges and resources) in predicting pathways to college. The Bridging Multiple Worlds Model frames this longitudinal study of 120 African American and Latino youth in outreach programs. We examined students' family backgrounds; challenges and resources across family, school, peer, and community worlds; and high school math pathways as predictors of college eligibility and enrollment. African American students more typically had U. S. born, college-educated parents, and Latino students, immigrant parents with high school education or less. Second, students saw parents as greater resources than teachers, siblings, and themselves; peers and teachers were their greatest challenges. Youth distinguished resources and challenges more by their source than form. Third, high school math and English grades rose and fell together, with early math grades predicting college eligibility. Five math pathways emerged: steady, slowly declining, rapidly declining, increasing, and "back on track" toward college, but pathways did not always predict college choices. Fourth, although family background predicted few outcomes, parents' and teachers' help and siblings' challenges predicted grades, eligibility, and admission to prestigious colleges. Findings highlight both capital and challenge models for science, policy, and programs involving diversity and equity.     

Hey Students,That Can Is Full of Energy!

This effective technique has third- and fourth-grade students explore potential and kinetic energy and explain their discoveries. Students investigate what it takes to make a paint can roll forward and come right back, without seeing inside. Students experience science as an inquiry and develop their critical thinking skills. Students can also relate their exploratory experiences to real-life situations they experience at their school.     

BraX-Ray: An X-Ray of the Brazilian Computer Science Graduate Programs

Research productivity assessment is increasingly relevant for allocation of research funds. On one hand, this assessment is challenging because it involves both qualitative and quantitative analysis of several characteristics, most of them subjective in nature. On the other hand, current tools and academic social networks make bibliometric data web-available to everyone for free. Those tools, especially when combined with other data, are able to create a rich environment from which information on research productivity can be extracted. In this context, our work aims at characterizing the Brazilian Computer Science graduate programs and the relationship among themselves. We (i) present views of the programs from different perspectives, (ii) rank the programs according to each perspective and a combination of them, (iii) show correlation between assessment metrics, (iv) discuss how programs relate to another, and (v) infer aspects that boost programs'' research productivity. The results indicate that programs with a higher insertion in the coauthorship network topology also possess a higher research productivity between 2004 and 2009.     

"有了老一辈打下的基础,我们才有今天的发展”

编者按 :从今年起本刊开辟了“科学家园地”栏目 ,得到广大读者的肯定。在此 2 0世纪末 ,新的世纪即将来临之际 ,我们更加缅怀为我国现代植物学作出奠基性贡献的老一代植物学家。他们热爱祖国 ,献身科学 ,在非常困难的条件下 ,在教学培养人材方面和植物学各分支学科的研究方面都作出了开创性的巨大贡献。他们的功绩将永垂史册。限于篇幅 ,本期仅选出几位代表人物 ,简介其生平 ,以讠志纪念。     

The Educational Experience and Performance of Immigrant and Minority Students in Israel

The educational needs of Jewish and Arab primary and secondary school-age student populations are provided by two separate and parallel educational systems. The immigrant context is discussed first, then educational issues pertaining to the Arab minority are examined. Emphasis is placed on emerging trends in the educational treatment of immigrant children as well as on shifts in educational policy and practice in the Arab sector. The educational experience and performance of immigrant students and Israeli Arab students are discussed within this broader context.     

浅论传统义利观在医学类大学生培育中的价值

随着传统义利观在中国传统文化中的不断丰富和发展,深深地影响着人们的价值观,并在人们的心中形成一种道德自律和民族自觉,对人们的行为发挥着重要的指导作用。在对医学生的培养教育中,往往只注重科学教育,缺乏包括义利观教育等在内的人文教育成为医学生培养系统亟待解决的问题。作为医学院校应当明确当代医患矛盾频出的关键所在,强调医学生建立＂重义轻利＂的人文理念,不断提高医疗服务道德水平。