Direct combination: a new user interaction principle for mobile and ubiquitous HCI

Direct Combination (DC) is a recently introduced user interaction principle. The principle (previously applied to desktop computing) can greatly reduce the degree of search, time, and attention required to operate user interfaces. We argue that Direct Combination applies particularly aptly to mobile computing devices, given appropriate interaction techniques, examples of which are presented here. The reduction in search afforded to users can be applied to address several issues in mobile and ubiquitous user interaction including: limited feedback bandwidth; minimal attention situations; and the need for ad-hoc spontaneous interoperation and dynamic reconfiguration of multiple devices. When Direct Combination is extended and adapted to fit the demands of mobile and ubiquitous HCI, we refer to it as Ambient Combination (AC) . Direct Combination allows the user to exploit objects in the environment to narrow down the range of interactions that need be considered (by system and user). When the DC technique of pairwise or n-fold combination is applicable, it can greatly lessen the demands on users for memorisation and interface navigation. Direct Combination also appears to offers a new way of applying context-aware information. In this paper, we present Direct Combination as applied ambiently through a series of interaction scenarios, using an implemented prototype system

Analysis of glycopeptides, glycans and polysaccharides by mass spectrometry

Diese Doktorarbeit beschäftigt sich mit der Analyse von Glykopeptiden, Glykanen und Polysacchariden in der MALDI-Massenspektrometrie (MS). Sie besteht aus drei originalen Forschungsartikeln, die die Verbesserung der Signalintensitäten von aus Kohlenhydraten aufgebauten Biopolymeren zum Ziel haben. Diese Moleküle zeigen vor allem in der Mischung mit anderen Analyten, zum Beispiel Peptiden, eine verminderte Ionenausbeute, die dazugehörigen Signale erscheinen im Massenspektrum entweder mit sehr geringer Intensität oder sind vollständig unterdrückt. Es gibt verschiedene Ansätze um dieses Problem zu umgehen und die Analyse von Kohlenhydraten zu verbessern. Eine Möglichkeit ist die Trennung der Analyte vor der massenspektrometrischen Messung um dadurch die Unterdrückungserscheinungen zu minimieren. Eine zweite Variante ist die chemische Derivatisierung, um eine bessere Stabilisierung der Ionen zu erreichen, eine weitere ist die Entwicklung alternativer MALDI-Matrices oder Präparationsmethoden. Die erste Publikation beschäftigt sich mit einer Derivatisierungsreaktion, die die Ionenausbeute von glykosylierten Peptiden erhöht. Durch die gewählte AQC-Derivatisierung konnten Glykopeptide, die einen kleinen Peptid- aber einen relativ großen Kohlenhydratanteil besitzen, in der Mischung mit nicht-glykosylierten Peptiden analysiert werden. In der zweiten Arbeit wird eine neu entwickelte ionisch-flüssige Matrix vorgestellt, die besonders für Glykopeptide und Glykane geeignet ist, da mit deren Hilfe deutlich höhere relative Signalintensitäten erzielt wurden als mit herkömmlichen kristallinen Matrices. Mit dieser Matrix war es möglich, die von Glykopeptiden enzymatisch abgespalteten Glykane ohne weitere Behandlung oder Trennung mittels MALDI-MS zu analysieren, d.h. in Gegenwart aller anderen Peptide eines tryptischen Verdaus. In der dritten Publikation wurde eine bereits etablierte ionisch-flüssige Matrix in Bezug auf ihre Eignung für die Bestimmung der Massenverteilung von relativ einfach aufgebauten Polysacchariden, nämlich Pullulanen, untersucht. Obwohl diese Kohlenhydrate relativ leicht während des MALDI-Prozesses fragmentieren, konnten präzise Daten für die Massenverteilung und Polydispersität berechnet werden. Die genaue Kenntnis dieser Daten ist von Bedeutung, da diese Verbindungen als Kalibrier-Standards in der wässrigen Size-Exclusion-Chromatographie Verwendung finden.This thesis deals with the analysis of glycopeptides, glycans and polysaccharides by means of MALDI mass spectrometry (MS). It comprises three original research articles which address the improvement of MS signal intensities of biopolymers containing carbohydrate structures. These molecules show especially in combination with other analytes, e.g., peptides, a reduced ionization yield, the associated signals appear in the mass spectrum with very low intensity or are completely suppressed. There are different approaches to overcome this problem and improve the analysis of carbohydrates. One possibility is the separation of the analytes before the mass spectrometric measurement in order to minimize the suppression of ionization. A second strategy is based on chemical derivatization to achieve better stabilized ions, a third one is the development of alternative MALDI matrices and preparation methods. The first publication investigates a derivatization procedure aimed to increase the ionization yield of glycosylated peptides. The chosen AQC-derivatization enabled a more comprehensive MALDI-MS analysis of glycopeptides in the presence of non-glycosylated peptides, particularly those containing a small backbone but relatively large carbohydrate moieties. In the second work a newly developed ionic liquid matrix was investigated which turned out to be especially useful for the analysis of glycopeptides and glycans as significantly higher relative signal intensities could be achieved compared to conventional crystalline matrices. With this matrix it was possible to analyze glycans enzymatically cleaved off from glycopeptides without further treatment or separation, i.e., in the presence of all other peptides of a tryptic digest. In the third publication an already established ionic liquid matrix was investigated with regard to its suitability to analyze the mass distribution of relatively simple composed polysaccharides, namely pullulans. Although these carbohydrates are prone to easy fragmentation during the MALDI process, accurate mass distribution and polydispersity data could be assessed. The exact knowledge of these data is of importance when using these compounds as calibration standards for aqueous size-exclusion chromatography

Tangible interfaces for manipulating aggregates of digital information

Thesis (Ph. D.)--Massachusetts Institute of Technology, School of Architecture and Planning, Program in Media Arts and Sciences, 2002.Includes bibliographical references (p. 255-269).This thesis develops new approaches for people to physically represent and interact with aggregates of digital information. These support the concept of Tangible User Interfaces (TUIs), a genre of human-computer interaction that uses spatially reconfigurable physical objects as representations and controls for digital information. The thesis supports the manipulation of information aggregates through systems of physical tokens and constraints. In these interfaces, physical tokens act as containers and parameters for referencing digital information elements and aggregates. Physical constraints are then used to map structured compositions of tokens onto a variety of computational interpretations. This approach is supported through the design and implementation of several systems. The mediaBlocks system enables people to use physical blocks to "copy and paste" digital media between specialized devices and general-purpose computers, and to physically compose and edit this content (e.g., to build multimedia presentations). This system also contributes new tangible interface techniques for binding, aggregating, and disaggregating sequences of digital information into physical objects.(cont.) Tangible query interfaces allow people to physically express and manipulate database queries. This system demonstrates ways in which tangible interfaces can manipulate larger aggregates of information. One of these query approaches has been evaluated in a user study, which has compared favorably with a best-practice graphical interface alternative. These projects are used to support the claim that physically constrained tokens can provide an effective approach for interacting with aggregates of digital information.by Brygg Anders Ullmer.Ph.D

Models and mechanisms for tangible user interfaces

Thesis (M.S.)--Massachusetts Institute of Technology, Program in Media Arts & Sciences, 1997.Includes bibliographical references (leaves 79-82).Brygg Anders Ullmer.M.S

High Sensitivity Mass Spectrometric Quantification of Serum Growth Hormone by Amphiphilic Peptide Conjugation

Amphiphilic peptide conjugation affords a significant increase in sensitivity with protein quantification by electrospray-ionization mass spectrometry. This has been demonstrated here for human growth hormone in serum using N-(3-iodopropyl)-N,N,N-dimethyloctylammonium iodide (IPDOA-iodide) as derivatizing reagent. The signal enhancement achieved in comparison to the method without derivatization enables extension of the applicable concentration range down to the very low concentrations as encountered with clinical glucose suppression tests for patients with acromegaly. The method has been validated using a set of serum samples spiked with known amounts of recombinant 22 kDa growth hormone in the range of 0.48 to 7.65 \mug/L. The coefficient of variation (CV) calculated, based on the deviation of results from the expected concentrations, was 3.5% and the limit of quantification (LoQ) was determined as 0.4 \mug/L. The potential of the method as a tool in clinical practice has been demonstrated with patient samples of about 1 \mug/L

Synthesis, Biodistribution and In vitro Evaluation of Brain Permeable High Affinity Type 2 Cannabinoid Receptor Agonists [11C]MA2 and [18F]MA3

Abstract The type 2 cannabinoid receptor (CB2) is a member of the endocannabinoid system and is known for its important role in (neuro)inflammation. A PET-imaging agent that allows in vivo visualization of CB2 expression may thus allow quantification of neuroinflammation. In this paper, we report the synthesis, radiosynthesis, biodistribution and in vitro evaluation of a carbon-11 ([11C]MA2) and a fluorine-18 ([18F]MA3) labeled analogue of a highly potent N-arylamide oxadiazole CB2 agonist (EC50 = 0.015 nM). MA2 and MA3 behaved as potent CB2 agonist (EC50: 3 nM and 0.1 nM, respectively) and their in vitro binding affinity for hCB2 was found to be 87 nM and 0.8 nM, respectively. Also MA3 (substituted with a fluoro ethyl group) was found to have higher binding affinity and EC50 values when compared to the originally reported trifluoromethyl analogue 12. [11C]MA2 and [18F]MA3 were successfully synthesized with good radiochemical yield, high radiochemical purity and high specific activity. In mice, both tracers were efficiently cleared from blood and all major organs by the hepatobiliary pathway and importantly these compounds showed high brain uptake. In conclusion, [11C]MA2 and [18F]MA3 are shown to be high potent CB2 agonists with good brain uptake, these favorable characteristics makes them potential PET probes for in vivo imaging of brain CB2 receptors. However in view of its higher affinity and selectivity, further detailed evaluation of MA3 as a PET tracer for CB2 is warranted

Palladium Membrane with High Density of Large-Angle Grain Boundaries to Promote Hydrogen Diffusivity

A higher density of large-angle grain boundaries in palladium membranes promotes hydrogen diffusion whereas small-angle grain boundaries suppress it. In this paper, the microstructure formation in 10 µm thick palladium membranes is tuned to achieve a submicronic grain size above 100 nm with a high density of large-angle grain boundaries. Moreover, changes in the grain boundaries’ structure is investigated after exposure to hydrogen at 300 and 500 °C. To attain large-angle grain boundaries in Pd, the coating was performed on yttria-stabilized zirconia/porous Crofer 22 APU substrates (intended for use later in an ultracompact membrane reactor). Two techniques of plasma sprayings were used: suspension plasma spraying using liquid nano-sized powder suspension and vacuum plasma spraying using microsized powder as feedstock. By controlling the process parameters in these two techniques, membranes with a comparable density of large-angle grain boundaries could be developed despite the differences in the fabrication methods and feedstocks. Analyses showed that a randomly oriented submicronic structure could be attained with a very similar grain sizes between 100 and 500 nm which could enhance hydrogen permeation. Exposure to hydrogen for 72 h at high temperatures revealed that the samples maintained their large-angle grain boundaries despite the increase in average grain size to around 536 and 720 nm for vacuum plasma spraying and suspension plasma spraying, respectively