164 research outputs found

    Crown Ether-Metal ‘Sandwiches’ As Linking Mechanisms in Assembled Nanoparticle Films

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    Crown ether ligands attached to monolayer-protected clusters (MPCs) were assembled as films and the linking mechanism between the crown ether–metal ion–crown ether bridges between nanoparticles was examined. Thicker films exhibited a red shift in the absorbance maximum for the surface plasmon band which was attributed to the increasing aggregation and cross linking within the film. Quantized double layer charging peaks suggest that film growth is selective toward a specific core size or exchange rate, either of which affect the number of potential linking ligands in the periphery of the MPCs. Multi-layer growth of films was only achieved with metal ions capable of coordinating within the cavity of the 15-crown-5 ether. Our exchange reaction parameters are in stark contrast to other types of MPC film assemblies

    Probabilistic approaches for modeling text structure and their application to text-to-text generation

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    Since the early days of generation research, it has been acknowledged that modeling the global structure of a document is crucial for producing coherent, readable output. However, traditional knowledge-intensive approaches have been of limited utility in addressing this problem since they cannot be effectively scaled to operate in domain-independent, large-scale applications. Due to this difficulty, existing text-to-text generation systems rarely rely on such structural information when producing an output text. Consequently, texts generated by these methods do not match the quality of those written by humans – they are often fraught with severe coherence violations and disfluencies. In this chapter, I will present probabilistic models of document structure that can be effectively learned from raw document collections. This feature distinguishes these new models from traditional knowledge intensive approaches used in symbolic concept-to-text generation. Our results demonstrate that these probabilistic models can be directly applied to content organization, and suggest that these models can prove useful in an even broader range of text-to-text applications than we have considered here.National Science Foundation (U.S.) (CAREER grant IIS- 0448168)Microsoft Research. New Faculty Fellowshi

    Hemobilia and pancreatitis as complications of a percutaneous transhepatic cholangiogram

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    Percutaneous transhepatic cholangiography (PTC) was performed on a 23-year-old male because of an atypical progression of hepatitis B antigen-negative hepatitis. No bile duct was entered and the procedure was uneventful. However, celiac angiography the day following PTC revealed abnormal liver vessels in the target area and the patient developed hemobilia and clinical pancreatitis, causing common duct obstruction. Symptomatology persisted until celiotomy 32 days after PTC. Clots were found obstructing the common bile duct.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44383/1/10620_2005_Article_BF01071178.pd

    Risk and Cooperation: Managing Hazardous Fuel in Mixed Ownership Landscapes

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    Managing natural processes at the landscape scale to promote forest health is important, especially in the case of wildfire, where the ability of a landowner to protect his or her individual parcel is constrained by conditions on neighboring ownerships. However, management at a landscape scale is also challenging because it requires cooperation on plans and actions that cross ownership boundaries. Cooperation depends on people’s beliefs and norms about reciprocity and perceptions of the risks and benefits of interacting with others. Using logistic regression tests on mail survey data and qualitative analysis of interviews with landowners, we examined the relationship between perceived wildfire risk and cooperation in the management of hazardous fuel by nonindustrial private forest (NIPF) owners in fire-prone landscapes of eastern Oregon. We found that NIPF owners who perceived a risk of wildfire to their properties, and perceived that conditions on nearby public forestlands contributed to this risk, were more likely to have cooperated with public agencies in the past to reduce fire risk than owners who did not perceive a risk of wildfire to their properties. Wildfire risk perception was not associated with past cooperation among NIPF owners. The greater social barriers to private–private cooperation than to private–public cooperation, and perceptions of more hazardous conditions on public compared with private forestlands may explain this difference. Owners expressed a strong willingness to cooperate with others in future cross-boundary efforts to reduce fire risk, however. We explore barriers to cooperative forest management across ownerships, and identify models of cooperation that hold potential for future collective action to reduce wildfire risk

    Role of forested land for natural flood management in the UK: A review

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    Linking genes to literature: text mining, information extraction, and retrieval applications for biology

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    Efficient access to information contained in online scientific literature collections is essential for life science research, playing a crucial role from the initial stage of experiment planning to the final interpretation and communication of the results. The biological literature also constitutes the main information source for manual literature curation used by expert-curated databases. Following the increasing popularity of web-based applications for analyzing biological data, new text-mining and information extraction strategies are being implemented. These systems exploit existing regularities in natural language to extract biologically relevant information from electronic texts automatically. The aim of the BioCreative challenge is to promote the development of such tools and to provide insight into their performance. This review presents a general introduction to the main characteristics and applications of currently available text-mining systems for life sciences in terms of the following: the type of biological information demands being addressed; the level of information granularity of both user queries and results; and the features and methods commonly exploited by these applications. The current trend in biomedical text mining points toward an increasing diversification in terms of application types and techniques, together with integration of domain-specific resources such as ontologies. Additional descriptions of some of the systems discussed here are available on the internet

    Architectural Paint Research and the Archaeology of Buildings

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    Architectural Paint Research (APR) is the archaeological study of interior and exterior applied decoration. Over time, applied layers of paint and other decorative finishes build-up on the surface of a built structure, encapsulating microscopic deposits of material evidence. This evidence can be used to inform the phase dating of a structure, or illuminate the historic function of a space. It can challenge preconceived ideas of how specific areas were decorated, and track the changes in aesthetics over time. It can identify when architects’ ideologies have been balanced by practical considerations. It can provide an insight into the intangible and ephemeral atmosphere that decoration gives to a room. Finally, it can examine the dirt trapped between layers of decoration and thus categorize the physical environmental conditions that surrounded a building at varying points in its history. Although used in the commercial heritage and conservation sectors, Architectural Paint Research is almost completely unknown to building archaeologists. This article aims to introduce APR to a new audience, and argues that is an invaluable tool in the archaeological interpretation of buildings
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