Technische Möglichkeiten und Akzeptanz mobiler Anwendungen

Mobile data communication applications, referred to in this paper as mobile applications, were one of the technological innovation and investment targets in recent years. From the past it became obvious that mono-disciplinary approaches to investigate mobile applications have shortcomings when it comes to successful innovation and investment decisions as interdependencies are insufficiently addressed. The paper therefore aims at structuring the scientific contributions of computer science, business economics and sociology in the context of mobile applications to approximate a holistic understanding comprising technological feasibility, economic opportunities and human needs.     

Synthesis and thermodynamics of oligonucleotides containing chirally pure R(P) methylphosphonate linkages

Methylphosphonate (MP) oligodeoxynucleotides (MPOs) are metabolically stable analogs of conventional DNA containing a methyl group in place of one of the non-bonding phosphoryl oxygens. All 16 possible chiral R(P) MP dinucleotides were synthesized and derivatized for automated oligonucleotide synthesis. These dimer synthons can be used to prepare (i) all-MP linked oligonucleotides having defined R(P) chirality at every other position (R(P) chirally enriched MPOs) or (ii) alternating R(P) MP/phosphodiester backbone oligonucleotides, depending on the composition of the 3'-coupling group. Chirally pure dimer synthons were also prepared with 2'-O-methyl sugar modifications. Oligonucleotides prepared with these R(P) chiral methylphosphonate linkage synthons bind RNA with significantly higher affinity than racemic MPOs.     

A Water Cyclone to Preserve Insoluble Aerosols in Liquid Flow—An Interface to Flow Cytometry to Detect Airborne Nucleic Acid

A miniature cyclone was designed to gently capture fine aerosols into a continuous liquid flow. The geometry of the cyclone was designed so that the friction of the turning air swirls a 100 μl volume of water at the base of the cone, creating a standing liquid vortex which coats the inside deposition surface. The collection efficiency of the cyclone was characterized as a function of insoluble particle size, both in stand-alone operation and preceded by aerosol growth by water vapor condensation. The aerosol growth lowered the smallest collected particle size and created synonymous sample-into-substrate material conditions at the point of impact. The cyclone collection efficiencies were higher than 88% for the fluorescent polystyrene latex bead diameter sizes 50–3000 nm. The cyclone was further interfaced to a flow cytometer to detect airborne nucleic acid (as a virus test aerosol) in the cyclone sample flow. The flow cytometer, which is commonly used for single cell identification via fluorescence, was modified to accept a continuous sample flow (nominal 60 μl min^?1) from the cyclone for real-time detection. A rod-shaped plant virus (Tobamovirus) and a protein-enveloped insect virus (Baculovirus) were aerosolized, collected by the cyclone, and stained inline using the nucleic acid dyes SYBR Green I, SYTO-9, and SYTO-24 (Molecular Probes, Inc.). In addition, an Environmental Scanning Electron Microscope (ESEM) was used to confirm the collection of single virus particles and qualitatively evaluate the degree to which the aerosolization and collection process affected the integrity of the virus.     

Main issues in protocol testing

The community of software testing and that of protocol testing are traditionally disjoint. It is seldom the case that protocol testing experts present papers at the large software testing conferences and vice versa. This raises the question about the peculiarities of protocol testing with respect to general software testing. Here we will examine those peculiarities and the consequences in terms of specific methodology developed for protocol testing.     

Current Challenges in Nucleic Acid Synthesis

Our understanding of the role of nucleic acids in regulating the process of life is growing rapidly. As researchers delve deeper into the cellular activity of molecules such as microRNA, small interfering RNA, and long non-coding RNA, the oligonucleotide chemist is confronted with the challenge of synthesizing the tools needed to continue this work. Furthermore, new applications are being developed that require increasingly complicated oligonucleotide constructs. In this review, we explore the current challenges confronting oligonucleotide synthesis, describe the chemistry and the enzymology being developed in response to those challenges, and discuss future challenges as-yet unmet.     

Parvovirus B19-antibody serosurvey in 500 developmentally disabled subjects

Inflammatory cytokines (interleukin [IL]-1 and tumor necrosis factor [TNF]) have specific inhibitors (IL-1 receptor antagonist [IL-1Ra] and TNF-soluble receptors), the concentration of which can indicate activation and regulation of this system. We measured IL-1 and IL-1Ra in the cerebrospinal fluid (CSF) of HIV-infected patients and seronegative controls. High IL-1Ra concentrations were found in samples from patients with opportunistic meningoencephalitis, even in the presence of normal cell count and protein content, not in samples from patients with leucoencephalopathies or controls. Therefore, IL-1Ra appears to be a sensitive marker of inflammation in the central nervous system. In contradistinction to previous results obtained from blood measurement, IL-1alpha and IL-1beta remained below detectable levels in all cases, suggesting that IL-1 may be regulated differently in the central nervous system and in the blood.     

Field and Laboratory Evaluation of the Thermo Electron 5020 Sulfate Particulate Analyzer

The Thermo Electron Model 5020 Sulfate Particulate Analyzer is a recently commercialized instrument that provides continuous measurements of the sulfate component of ambient particulate matter. The technique uses a stainless steel rod placed inside a quartz oven to reduce the particle sulfate to sulfur dioxide; followed by pulsed fluorescence detection of the sulfur dioxide. Field and laboratory evaluations of a pre-production version of the analyzer are described as well as laboratory evaluations of the pre-production version and two production units. Laboratory tests concentrated on challenging the instruments with ammonium sulfate aerosol, but tests with sodium, potassium, and calcium sulfate are reported as well. The instrument performed very well in field and laboratory settings, reporting values that were highly correlated with continuous mass measurements in the lab, and 24-hour filters in the field. Conversion/detection efficiencies for ammonium sulfate in the laboratory, and for ambient sulfate aerosol at our rural site in Addison, New York, were both very close to 80%. Laboratory conversion efficiencies for calcium, sodium, and potassium sulfate salts ranged from 4% to 63%. These lower efficiencies for mineral-type sulfates will be an important consideration in areas with significant concentrations of sea salt or mineral dust sulfate, and less important for the high sulfate Eastern US which is dominated by ammonium sulfate.     

Autonomous Ant-based Public Key Authentication Mechanism for Mobile Ad-hoc Networks

In mobile ad-hoc networks (MANETs), where there is no centralized authority to provide authentication, trust and reputation mechanisms are applied to maintain security by identifying trustworthy and untrustworthy nodes. However, traditional authentication mechanisms are not viable for MANETs due to the lack of infrastructure and frequent topology changes. In this paper, we propose a self-organized and localized public key authentication mechanism based on ant colony systems. Every node generates its own public-private key pair, issues certificates to neighboring nodes and provides on-demand authentication services by means of gathering certificate chains towards a target node. Pheromone concentration left by ants along the path of the certificate chains represents the trust level of a node towards other nodes. This model is able to authenticate public keys by selecting the most trustworthy certificate chains gathered by ants and can identify and exclude certificate chains with malicious nodes.