IETF对IPv6部署的支持

2007年12月2～7日,国际互联网标准化组织IETF在加拿大温哥华召开第70次大会。此次会议,对之前在芝加哥召开的第69次大会进行了总结和回顾。第69次大会上对IPv6的部署和研究工作有较大范围的关注,部分关注方向继续成为第70次大会的热点话题。为此,本刊选取了部分重要文章进行译介,供网络研究者参考。     

A Good Job Is Hard to Find … Until Students Know What They Do Best

Why don't more students use the career center? Shane J. Lopez argues that the traditional career center has not kept up with students’ needs. He suggests that they reimagine themselves as places where students identify and nurture their strengths in order to find fulfilling work and create fulfilling lives.     

Inclusive education and best practice for children with autism spectrum disorder: an integrated approach

Many parents of children with autism spectrum disorder (ASD) have reported general discontent with the services offered by the education system and have advocated for increased ASD‐specific services to better meet their children’s educational needs. The elements of best practice offer an ideal model for educational support. There are, however, limitations to advocating ASD‐specific services. This paper describes how best practice for ASD as an educational model fits within what is described as authentic inclusion. Further, it is suggested that the ASD community align with the greater inclusive education reform movement. With the use of this unified model of education, all children will receive the educational support they require.     

Rapid phenotypic evolution with shallow genomic differentiation during early stages of high elevation adaptation in Eurasian Tree Sparrows

Known as the ‘third polar region’, the Qinghai-Tibet Plateau represents one of the harshest highland environments in the world and yet a number of organisms thrive there. Previous studies of birds, animals and humans have focused on well-differentiated populations in later stages of phenotypic divergence. The adaptive processes during the initial phase of highland adaptation remain poorly understood. We studied a human commensal, the Eurasian Tree Sparrow, which has followed human agriculture to the Qinghai-Tibet Plateau. Despite strong phenotypic differentiation at multiple levels, in particular in muscle-related phenotypes, highland and lowland populations show shallow genomic divergence and the colonization event occurred within the past few thousand years. In a one-month acclimation experiment investigating phenotypic plasticity, we exposed adult lowland tree sparrows to a hypoxic environment and did not observe muscle changes. Through population genetic analyses, we identified a signature of polygenic adaptation, whereby shifts in allele frequencies are spread across multiple loci, many of which are associated with muscle-related processes. Our results reveal a case of positive selection in which polygenic adaptation appears to drive rapid phenotypic evolution, shedding light on early stages of adaptive evolution to a novel environment.     

Thermally multiplexed polymerase chain reaction

Amplification of multiple unique genetic targets using the polymerase chain reaction (PCR) is commonly required in molecular biology laboratories. Such reactions are typically performed either serially or by multiplex PCR. Serial reactions are time consuming, and multiplex PCR, while powerful and widely used, can be prone to amplification bias, PCR drift, and primer-primer interactions. We present a new thermocycling method, termed thermal multiplexing, in which a single heat source is uniformly distributed and selectively modulated for independent temperature control of an array of PCR reactions. Thermal multiplexing allows amplification of multiple targets simultaneously—each reaction segregated and performed at optimal conditions. We demonstrate the method using a microfluidic system consisting of an infrared laser thermocycler, a polymer microchip featuring 1 μl, oil-encapsulated reactions, and closed-loop pulse-width modulation control. Heat transfer modeling is used to characterize thermal performance limitations of the system. We validate the model and perform two reactions simultaneously with widely varying annealing temperatures (48 °C and 68 °C), demonstrating excellent amplification. In addition, to demonstrate microfluidic infrared PCR using clinical specimens, we successfully amplified and detected both influenza A and B from human nasopharyngeal swabs. Thermal multiplexing is scalable and applicable to challenges such as pathogen detection where patients presenting non-specific symptoms need to be efficiently screened across a viral or bacterial panel.     

Simplifying Causal Complexity: How Interactions Between Modes of Causal Induction and Information Availability Lead to Heuristic‐Driven Reasoning

This article considers a set of well‐researched default assumptions that people make in reasoning about complex causality and argues that, in part, they result from the forms of causal induction that we engage in and the type of information available in complex environments. It considers how information often falls outside our attentional frame such that covariation falls short, mechanisms can be nonobvious, and the testimony that others offer is typically subject to the same constraints as our own perceptions. It underscores the importance of multiple modes of causal induction used in support of one another when discerning and teaching about causal complexity. It considers the importance of higher order reflection on the nature of causality that recognizes the challenging features of complex causality and how it interacts with human causal cognition.     

Inclusive practice within the lived cultures of school communities: research case studies in teaching,learning and inclusion

This paper provides an account of a teacher's use of theory as a tool to develop inclusive practice through a social studies programme in a new entrant class. The account illustrates the ways in which the teacher drew on research to assist in the facilitation of an inclusive educational environment. Presented are research case studies the teacher encountered in an in-service teacher education programme, and the ‘social constructionist’ and ‘personal tragedy’ models that were used as theoretical tools to assist the teacher's planning and teaching practice. Mounted cameras, broadcast microphones and pre- and post-unit interviews with the teacher and students were used to explore the lived culture of the classroom, and the nature and effectiveness of the strategies the teacher used. An ‘interrupted narrative’ methodology engages the reader in the interplay between research and theory in the research case studies. Four major strategies used by the teacher have been identified and these are presented as theoretical tools for other teachers and teacher educators to use, critique and develop to support inclusive practice in their own contexts.