An MTIDD Based Firewall

This paper explores the use of Multi-Terminal Interval Decision Diagrams (MTIDDs) as the central structure of a firewall packet filtering mechanism. This is done by first relating the packet filtering problem to predicate logic, then implementing a prototype which is used in an empirical evaluation. The main benefits of the MTIDD structure are that it provides access to Boolean algebra over filters, efficient classification time, and a compact representation. Results from the empirical evaluation shows that MTIDDs are scalable in terms of memory usage: a 50,000 rule filter requires only 3MB of memory, and efficient for packet classification: it is able to handle more rules than the schemes it was compared to without causing a degradation in performance.     

Synthesis of dye linked conducting block copolymers, dye linked conducting homopolymers and preliminary application to photovoltaics

A synthetic approach to the synthesis of a large super molecule composed of two chemically different conducting polymer blocks with, respectively, high and low lying electronic energy levels linked through a porphyrin dye molecule is presented. The synthetic strategies to these molecular architectures are discussed. Finally the molecular systems are applied to make photovoltaic devices and the rather low efficiency is discussed in terms of the synthetic approach.     

Lipochitin Oligosaccharides Immobilized through Oximes in Glycan Microarrays Bind LysM Proteins

Glycan microarrays have emerged as novel tools to study carbohydrate–protein interactions. Here we describe the preparation of a covalent microarray with lipochitin oligosaccharides and its use in studying proteins containing LysM domains. The glycan microarray was assembled from glycoconjugates that were synthesized by using recently developed bifunctional chemoselective aminooxy reagents without the need for transient carbohydrate protecting groups. We describe for the first time the preparation of a covalent microarray with lipochitin oligosaccharides and its use for studying proteins containing LysM domains. Lipochitin oligosaccharides (also referred to as Nod factors) were isolated from bacterial strains or chemoenzymatically synthesized. The glycan microarray also included peptidoglycan‐related compounds, as well as chitin oligosaccharides of different lengths. In total, 30 ligands were treated with the aminooxy linker molecule. The identity of the glycoconjugates was verified by mass spectrometry, and they were then immobilized on the array. The presence of the glycoconjugates on the array surface was confirmed by use of lectins and human sera (IgG binding). The functionality of our array was tested with a bacterial LysM domain‐containing protein, autolysin p60, which is known to act on the bacterial cell wall peptidoglycan. P60 showed specific binding to Nod factors and to chitin oligosaccharides. Increasing affinity was observed with increasing chitin oligomer length.     

Disambiguating grammars by exclusion of sub-parse trees

A method is presented for disambiguation of grammars, based on the idea of excluding certain forbidden sub-parse trees. Combined with recent developments in the theory of parser generation for ambiguous grammars, the method disambiguates large classes of grammars guaranteeing that the generated language is unchanged.     

Remote nocturnal bird classification by spectroscopy in extended wavelength ranges

We present optical methods at a wide range of wavelengths for remote classification of birds. The proposed methods include eye-safe fluorescence and depolarization lidar techniques, passive scattering spectroscopy, and infrared (IR) spectroscopy. In this paper we refine our previously presented method of remotely classifying birds with the help of laser-induced β-keratin fluorescence. Phenomena of excitation quenching are studied in the laboratory and are theoretically discussed in detail. It is shown how the ordered microstructures in bird feathers induce structural "colors" in the IR region with wavelengths of around 3-6 μm. We show that transmittance in this region depends on the angle of incidence of the transmitted light in a species-specific way and that the transmittance exhibits a close correlation to the spatial periodicity in the arrangement of the feather barbules. We present a method by which the microstructure of feathers can be monitored in a remote fashion by utilization of thermal radiation and the wing beating of the bird.     

Proteome Analysis of Thyroid Cancer Cells After Long-Term Exposure to a Random Positioning Machine

Annulling gravity during cell culturing triggers various types of cells to change their protein expression in a time dependent manner. We therefore decided to determine gravity sensitive proteins and their period of sensitivity to the effects of gravity. In this study, thyroid cancer cells of the ML-1 cell line were cultured under normal gravity (1?g) or in a random positioning machine (RPM), which simulated near weightlessness for 7 and 11?days. Cells were then sonicated and proteins released into the supernatant were separated from those that remained attached to the cell fragments. Subsequently, both types of proteins were fractionated by free-flow isoelectric focussing (FF-IEF). The fractions obtained were further separated by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) to which comparable FF-IEF fractions derived from cells cultured either under 1?g or on the RPM had been applied side by side. The separation resulted in pairs of lanes, on which a number of identical bands were observed. Selected gel pieces were excised and their proteins determined by mass spectrometry. Equal proteins from cells cultured under normal gravity and the RPM, respectively, were detected in comparable gel pieces. However, many of these proteins had received different Mascot scores. Quantifying heat shock cognate 71?kDa protein, glutathione S-transferase P, nucleoside diphosphate kinase A and annexin-2 by Western blotting using whole cell lysates indicated usefulness of Mascot scores for selecting the most efficient antibodies.     

Algorithms and estimators for summarization of unaggregated data streams

Statistical summaries of IP traffic are at the heart of network operation and are used to recover aggregate information on subpopulations of flows. It is therefore of great importance to collect the most accurate and informative summaries given the router's resource constraints. A summarization algorithm, such as Cisco's sampled NetFlow, is applied to IP packet streams that consist of multiple interleaving IP flows. We develop sampling algorithms and unbiased estimators which address sources of inefficiency in current methods. First, we design tunable algorithms whereas currently a single parameter (the sampling rate) controls utilization of both memory and processing/access speed (which means that it has to be set according to the bottleneck resource). Second, we make a better use of the memory hierarchy, which involves exporting partial summaries to slower storage during the measurement period.     

Bicycle urbanism as a competitive advantage in the neoliberal age: the case of bicycle promotion in Portland

In the light of the emergent ‘bicycle renaissance’ in the US, this paper analyses the rationale basis of bicycle role model, Portland's promotion of bicycling. By conceptualizing bicycle promotion as a ‘travelling idea’, the paper discusses the key rationales and discourses structuring how bicycle policies are translated into the City of Portland. The study finds that strong neoliberal rationales such as competitiveness, cost-effectiveness, and value for money are pivotal in Portland's legitimization of spending on bicycle promotion, with sustainability and equity concerns being comparatively neglected. It is argued that this approach raises serious questions about the bicycle's potential as an egalitarian and sustainable practice, and urges potential ‘bicycle cities’ and advocates to be aware of the incommensurability of the creative class strategy and environmental justice goals.     

New results for Constraint Markov Chains

This paper studies compositional reasoning theories for stochastic systems. A specification theory combines notions of specification and implementation with satisfaction and refinement relations, and a set of operators that together support stepwise design. One of the first behavioral specification theories introduced for stochastic systems is the one of Interval Markov Chains (IMCs), which are Markov Chains whose probability distributions are replaced by a conjunction of intervals. In this paper, we show that IMCs are not closed under conjunction, which gives a formal proof of a conjecture made in several recent works.In order to leverage this problem, we suggested to work with Constraint Markov Chains (CMCs) that is another specification theory where intervals are replaced with general constraints. Contrary to IMCs, one can show that CMCs enjoy the closure properties of a specification theory. In addition, we propose aggressive abstraction procedures for CMCs. Such abstractions can be used either to combat the state-space explosion problem, or to simplify complex constraints. In particular, one can show that, under some assumptions, the behavior of any CMC can be abstracted by an IMC.Finally, we propose an algorithm for counter-example generation, in case a refinement of two CMCs does not hold. We present a tool that implements our results. Implementing CMCs is a complex process and relies on recent advances made in decision procedures for theory of reals.     

Developing a molecular platform for potential carbon dioxide fixing

This paper presents an attempt to develop a new system for fixing carbon dioxide from the atmosphere. The proposed molecular system has been designed to have the capacity to spontaneously bind CO₂ from the atmosphere with high affinity. The molecular system is furthermore designed to have the ability to liberate CO₂ at a later stage in the process, i.e., in a separate compartment. The liberated CO₂ presents a carbon neutral way of obtaining pure CO₂. The proposed molecular system is based on a small stable organic molecule that potentially have two forms: one without bound CO₂ and one with bound CO₂. One class of molecules that undergo a reaction compatible with our purposal is the merocyanine dyes that exhibit photochromic properties. Based on this structural class of molecules, a system for the potential fixing of CO₂ has been developed.