1,758 research outputs found
Galaxy pairs in the Sloan Digital Sky Survey - IX: Merger-induced AGN activity as traced by the Wide-field Infrared Survey Explorer
Interactions between galaxies are predicted to cause gas inflows that can
potentially trigger nuclear activity. Since the inflowing material can obscure
the central regions of interacting galaxies, a potential limitation of previous
optical studies is that obscured Active Galactic Nuclei (AGNs) can be missed at
various stages along the merger sequence. We present the first large
mid-infrared study of AGNs in mergers and galaxy pairs, in order to quantify
the incidence of obscured AGNs triggered by interactions. The sample consists
of galaxy pairs and post-mergers drawn from the Sloan Digital Sky Survey that
are matched to detections by the Wide Field Infrared Sky Explorer (WISE). We
find that the fraction of AGN in the pairs, relative to a mass-, redshift- and
environment-matched control sample, increases as a function of decreasing
projected separation. This enhancement is most dramatic in the post-merger
sample, where we find a factor of 10-20 excess in the AGN fraction compared
with the control. Although this trend is in qualitative agreement with results
based on optical AGN selection, the mid-infrared selected AGN excess increases
much more dramatically in the post-mergers than is seen for optical AGN. Our
results suggest that energetically dominant optically obscured AGNs become more
prevalent in the most advanced mergers, consistent with theoretical
predictions.Comment: 8 pages, 7 figures accepted to MNRAS (with minor revisions
Monitoring Student Cues: Tracking Student Behaviour in Order to Improve Instruction in Higher Education
In this paper, we focus on monitoring, a particular aspect of reflection related to teaching. We define monitoring as a feedback mechanism which entails attending to and evaluating a multitude of cues in the envi- ronment in order to evaluate progress towards a goal. We direct our attention to monitoring because it is a way in which a teacher is able to gain understanding of how effective his/her teaching actions are. Thus, knowing what cues to evaluate (and being able to do so) is a critical skill in reflection. Further, we focus exclusively in this paper on the concur- rent monitoring of cues related to students since we believe that attention to student cues while teaching provides teachers with a window into their students' learning experiences. We call this particular type of reflection, reflection-in-action. As well as depicting multiple examples of monitoring drawn from our research, we explore the contribution of this work to the literature in higher education and to faculty development activities, particularly, to the growing literature on teacher thinking.Cet article est principalement consacré au «monitorage», c'est-à-dire à un aspect particulier de la réflexion portant sur l'enseignement. Nous entendons par monitorage un mécanisme de rétroaction qui consiste à observer et à évaluer une multitude de signaux dans un environnement donné afin de mesurer les progrès accomplis par rapport à un objectif. Nous nous intéressons au monitorage, car ce moyen permet au professeur de mesurer l'efficacité de ses interventions. Pour mener à bien cette réflexion, il est donc essentiel de pouvoir déterminer quels signaux il faut évaluer (et d'être en mesure de les évaluer). Cet article porte en outre exclusivement sur le monitorage simultané des signaux émis par les étudiants, car nous pensons que l'observation de ces signaux fournit au professeur un aperçu des apprentissages que font les étudiants. Nous appelons "réflexion sur le vif' ce type de réflexion. En plus d'offrir de nombreux exemples de monitorage tirés de nos recherches, nous étudions sous tous ses aspects la contribution qu'elles apportent aux études consacrées à l'enseignement supérieur et au perfectionnement des professeurs et particulièrement aux études de plus en plus nombreuses qui portent sur la pensée des professeurs
Rapid, multiplexed microfluidic phage display
The development of a method for high-throughput, automated proteomic screening could impact areas ranging from fundamental molecular interactions to the discovery of novel disease markers and therapeutic targets. Surface display techniques allow for efficient handling of large molecular libraries in small volumes. In particular,
phage display has emerged as a powerful technology for selecting peptides and proteins with enhanced, target-specific binding affinities. Yet, the process becomes cumbersome and time-consuming when multiple targets are involved.Here we demonstrate for the first time a microfluidic chip capable of identifying high affinity phage displayed peptides for multiple targets in just a single round and without the need for bacterial infection. The chip is shown to be able to yield well-established control consensus sequences while simultaneously
identifying new sequences for clinically important targets.
Indeed, the confined parameters of the device allow not only for highly controlled assay conditions but also introduce a significant time-reduction to the phage display process. We anticipate that this easily-fabricated, disposable device has the potential to impact areas
ranging from fundamental studies of protein, peptide, and molecular interactions, to applications such as fully automated proteomic screening
Meeting the requirements for supporting engineering design communication – Partbook
The Engineering Design Environment is evolving in many ways. Considerable amounts of data, information and knowledge are 'building up' within engineering companies and engineers are becoming involved in ever-more distributed collaboration activities to tackle complex multi-disciplinary challenges in the design of new products requiring the need to share knowledge. These changes are placing further challenges on Engineering Design Communication (EDC, a fundamental knowledge sharing activity) as the current methods of communication were never specifically designed to support such technical and highly-contextual communication. Much research has been performed on understanding EDC, thus enabling a list of requirements to support EDC to be generated. Therefore, this paper proposes a prescriptive tool, (PartBook) which instantiates these requirements and looks at the next steps being taken to evaluate the tool in meeting the requirements
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