Perfluoroalkyl polytriazines containing pendent iododifluoromethyl groups

New perfluoroalkyl polytriazines containing pendent iododifluoromethyl groups are prepared by the reaction of perfluoroalkyl dinitriles with ammonia to form poly(imidoylamidines), followed by the cyclization of the imidoylamidine groups with, e.g., various mixtures of a perfluoroacyl fluoride with an omega iodoperfluoroacyl fluoride. The polytriazines obtained can be cured by heat which causes crosslinking at the iododifluoromethyl groups by elimination of iodine and formation of carbon-to-carbon bonds

Efficiently Mapping Linear Algebra to High-Performance Code

Aware of the role that linear algebra plays in scientific applications, we investigate if/how matrix expressions can be efficiently evaluated with current high-level languages. On the one hand, the numerical linear algebra community has put a lot of effort in developing and optimizing a relatively small set of “universally” useful operations. These are packaged in libraries such as BLAS and LAPACK, and serve as building blocks for more complex computa- tions. On the other hand, the linear algebra expressions that arise in many domains are significantly more complex than those building blocks. We refer to the problem of expressing a linear algebra expression in terms of a set of available building blocks as the ”Linear Algebra Mapping Problem” (LAMP). In practice, users have two alternatives to solve a given LAMP: 1) either “manually”, by using C/C++ or FORTRAN in combination with explicit calls to BLAS & LAPACK 2) or “automatically” by using one of the high-level languages (or libraries) with an API that directly captures the expressions. In this presentation, we focus only on the latter. Specifically, we consider 6 languages (or libraries): Matlab, Julia, R, NumPy (Python), Eigen (C++), and Armadillo (C++), and carefully assess how effectively they translate linear algebra expressions to code, i.e., how well they solve LAMPs. We investigate a number of aspects that are critical for the efficient solution of a LAMP. These range from the most basic mapping problem “Given the expression A*B, does the language map it to a call to GEMM?”, to the optimal parenthesization, to the exploitation of properties, to the identification & elimination -if advantageous- of common sub-expressions, and more. Ultimately, the purpose of this study is to exhibit the core challenges related to the effective computation of linear algebra expressions, and to help the development of languages and libraries.Texas Advanced Computing Center (TACC

Supporting public decision making in policy deliberations: An ontological approach

This is the post-print version of the Paper. The official published version can be accessed from the link below - Copyright @ 2011 SpringerSupporting public decision making in policy deliberations has been a key objective of eParticipation which is an emerging area of eGovernment. EParticipation aims to enhance citizen involvement in public governance activities through the use of information and communication technologies. An innovative approach towards this objective is exploiting the potentials of semantic web technologies centred on conceptual knowledge models in the form of ontologies. Ontologies are generally defined as explicit human and computer shared views on the world of particular domains. In this paper, the potentials and benefits of using ontologies for policy deliberation processes are discussed. Previous work is then extended and synthesised to develop a deliberation ontology. The ontology aims to define the necessary semantics in order to structure and interrelate the stages and various activities of deliberation processes with legal information, participant stakeholders and their associated arguments. The practical implications of the proposed framework are illustrated.This work is funded by the European Commission under the 2006/1 eParticipation call

Regulation of type I interferons in health and autoimmune disease

Type I interferons (IFN) have a crucial role in the pathogenesis of a range of autoimmune diseases including systemic lupus erythematosus (SLE). Increased IFN activity is observed at preclinical stages and associated with disease progression, but the cause of this dysregulation remains unclear. Plasmacytoid dendritic cells (pDCs) produce large amounts of IFNs in viral infection, however their precise role in autoimmunity is still elusive. Peripheral blood and skin biopsies from different patient groups were used for gene expression assays, immunophenotyping, in vitro functional assays, transcriptomics and other assays to investigate the dysregulated IFN axis and the role of pDCs in preclinical autoimmunity and SLE. In preclinical autoimmunity and SLE, pDCs were found to exhibit an exhausted phenotype with: (i) loss of TLR-mediated IFN-α production; (ii) failure to induce T cell activation; (iii) transcriptional profile of cellular senescence; (iv) increased telomere erosion. In contrast, diffuse expression of type I IFNs was observed in the epidermis but not in leucocyte-infiltrating areas of patients with SLE as well as in non-lesional skin of individuals with preclinical autoimmunity. Additionally, keratinocytes isolated from non-lesional skin of patients with SLE and individuals with preclinical autoimmunity showed a significantly enhanced type I IFN expression in response to UV light and nucleic acids. Lastly, TNF-α regulates the function of pDCs by suppressing IFN-α production but enhancing a functional drift to antigen presentation and T cell activation. These findings revise our understanding of immune regulation in human autoimmunity. Non-haematopoietic tissue cells can perpetuate IFN responses; meanwhile the professional IFN-producing pDCs have lost their immunogenic properties. In patients with SLE, these insights may indicate potential therapeutic targets outside the conventional immune system, while knowledge of how IFN dysregulation initiates could allow disease prevention

A Jurisprudential Controversy over Law's Shared Authority?

The authority of law is generally understood to be the authority of a legal system. It may be quite straightforward to establish over whom the authority of a legal system is typically exercised: these are the persons whose legal rights and duties are specified and enforced by the legal system in question. A more troubling question asks who are the bearers of such authority. One may say that these are the legal officials. Other answers may be more specific. For instance, some would argue that legal authority rests with the courts of a legal system or with its supreme court; with its legislature or with both its courts and legislature. In his monograph, Shared Authority: Courts and Legislatures in Legal Theory, Dimitrios Kyritsis subscribes to this latter view

The state: A sine qua non of public law? A critique of Martin Loughlin’s state-centred approach to public law

Abstract: This article critically considers a state-centred approach to public law that has been epitomised in Martin Loughlin’s claim that the concept of the state is the sine qua non of public law. More precisely, the article argues against two theoretical tenets that underlie this state-centred approach. The first tenet is the consideration of state authority as absolute authority. The second tenet claims that public law has a deep distinctness from all other fields of law, which are contrasted to it by being described as constituting the realm of ordinary law. The article also challenges the ability of the aforementioned state-centred approach to fully account for the status and role of the doctrine of parliamentary sovereignty in the UK constitutional order. This challenge is discussed in light of a distinction between state sovereignty and parliamentary sovereignty

Colombus: providing personalized recommendations for drifting user interests

The query formulationg process if often a problematic activity due to the cognitive load that it imposes to users. This issue is further amplified by the uncertainty of searchers with regards to their searching needs and their lack of training on effective searching techniques. Also, given the tremendous growth of the world wide web, the amount of imformation users find during their daily search episodes is often overwhelming. Unfortunatelly, web search engines do not follow the trends and advancements in this area, while real personalization features have yet to appear. As a result, keeping up-to-date with recent information about our personal interests is a time-consuming task. Also, often these information requirements change by sliding into new topics. In this case, the rate of change can be sudden and abrupt, or more gradual. Taking into account all these aspects, we believe that an information assistant, a profile-aware tool capable of adapting to users’ evolving needs and aiding them to keep track of their personal data, can greatly help them in this endeavor. Information gathering from a combination of explicit and implicit feedback could allow such systems to detect their search requirements and present additional information, with the least possible effort from them. In this paper, we describe the design, development and evaluation of Colombus, a system aiming to meet individual needs of the searchers. The system’s goal is to pro-actively fetch and present relevant, high quality documents on regular basis. Based entirely on implicit feedback gathering, our system concentrates on detecting drifts in user interests and accomodate them effectively in their profiles with no additional interaction from their side. Current methodologies in information retrieval do not support the evaluation of such systems and techniques. Lab-based experiments can be carried out in large batches but their accuracy often questione. On the other hand, user studies are much more accurate, but setting up a user base for large-scale experiments is often not feasible. We have designed a hybrid evaluation methodology that combines large sets of lab experiments based on searcher simulations together with user experiments, where fifteen searchers used the system regularly for 15 days. At the first stage, the simulation experiments were aiming attuning Colombus, while the various component evaluation and results gathering was carried out at the second stage, throughout the user study. A baseline system was also employed in order to make a direct comparison of Colombus against a current web search engine. The evaluation results illustrate that the Personalized Information Assistant is effective in capturing and satisfying users’ evolving information needs and providing additional information on their behalf

Διαχείρηση Αέριων Εκπομπών από την Ξήρανση Βιοαποβλήτων

Εθνικό Μετσόβιο Πολυτεχνείο--Μεταπτυχιακή Εργασία. Διεπιστημονικό-Διατμηματικό Πρόγραμμα Μεταπτυχιακών Σπουδών (Δ.Π.Μ.Σ.) “Περιβάλλον και Ανάπτυξη

Nitrogen-functionalized porous carbons for enhanced CO2 capture

The global consequences of increased anthropogenic carbon dioxide emissions are well documented. To avoid the catastrophic long-term damages associated with climate change, much attention has been devoted to the development of CO2 emission mitigation strategies. A present challenge in the mitigation of anthropogenic CO2 emissions involves the design of less energy- and water-intensive capture technologies. Traditional capture methods, e.g. MEA solvent scrubbing, have prohibitive regeneration costs, and recent concerns in drought-ridden states like California have brought these water-intensive processes under increased scrutiny. Sorbent-based capture represents a promising solution to the aforementioned hurdles, as they do not incur the heavy energy penalties associated with solvent regeneration. However, to be considered competitive with their more mature, solvent-based counter-parts, these sorbents must exhibit i) high CO2 loading capacity and ii) high CO2/N2 selectivity. Ultra-microporous character and surface nitrogen functionality have been reported to be of great importance to the enhancement of CO2 capacity and CO2/N2 ideal selectivity. However, the role of pore size in combination with surface N-functionalities in the enhancement of these properties remains unclear. To investigate these effects, grand canonical Monte Carlo (GCMC) simulations were carried out on pure and functionalized 3-layer graphitic slit pore models. Theoretical isotherms were constructed as the PSD-weighted sum of individual slit-pore models of width varying from 3.5 to 200Å. In addition to pure and monovacancy-graphite, the following functional groups were isolated for testing at ~3% coverage: pyridinic nitrogen, pyrrolic nitrogen, quaternary nitrogen, and oxidized-pyridinic nitrogen. Our results reveal that nitrogen surface-functionalization can enhance CO2 loading by upwards of 90 percent over pure graphite. Increasing surface-coverage of quaternary-nitrogen resulted in enhanced loading, though higher coverage loadings converged at approximately 4 mmol CO2 g-1 sorbent. Charge analysis revealed that enhanced loading was strongly correlated with the oxidation state of surface-bound oxygen and, to a lesser extent, nitrogen at low pressures, with a decreasing effect at higher pressures. Functionally bound hydrogen contributed at higher (ambient) pressures suggesting a secondary mechanism of adsorbate stabilization. Ideal CO2/N2 selectivities were calculated for pure and N-doped models using both HL (low pressure) and IAST (working pressure) methods. Our results show that N-doping can enhance HL but not IAST selectivity. This is attributed to the introduction of a few highly active surface sites through surface N-modification. Additionally, selectivity was found to be greatly enhanced in the ultra-microporous volumes (3.5 - 7Å). These results illustrate that N-functionalization can influence CO2 and N2 adsorption behavior, particularly in narrower pores where opposing wall potentials overlap – an important consideration in the rational design of future carbon-based sorbents