238 research outputs found
ATOMAS : a transaction-oriented open multi agent system; final report
The electronic marketplace of the future will consist of a large number of services located on an open, distributed and heterogeneous platform, which will be used by an even larger number of clients. Mobile Agent Systems are considered to be a precondition for the evolution of such an electronic market. They can provide a flexible infrastructure for this market, i.e. for the installation of new services by service agents as well as for the utilization
of these services by client agents.
Mobile Agent Systems basically consist of a number of locations and agents. Locations are (logical) abstractions for (physical) hosts in a computer network. The network of locations serves as a unique and homogeneous platform, while the underlying network of hosts may be heterogeneous and widely distributed. Locations therefore have to guarantee independence from the underlying hard- and software. To make the Mobile Agent System an open platform, the system furthermore has to guarantee security of hosts against malicious attacks
deepregression: A Flexible Neural Network Framework for Semi-Structured Deep Distributional Regression
In this paper we describe the implementation of semi-structured deep distributional regression, a flexible framework to learn conditional distributions based on the combination of additive regression models and deep networks. Our implementation encompasses (1) a modular neural network building system based on the deep learning library TensorFlow for the fusion of various statistical and deep learning approaches, (2) an orthogonalization cell to allow for an interpretable combination of different subnetworks, as well as (3) pre-processing steps necessary to set up such models. The software package allows to define models in a user-friendly manner via a formula interface that is inspired by classical statistical model frameworks such as mgcv. The package's modular design and functionality provides a unique resource for both scalable estimation of complex statistical models and the combination of approaches from deep learning and statistics. This allows for state-of-the-art predictive performance while simultaneously retaining the indispensable interpretability of classical statistical models
Electrodeposited lead dioxide coatings
Lead dioxide coatings on inert substrates such as titanium and carbon now offer new opportunities for a material known for 150 years. It is now recognised that electrodeposition allows the preparation of stable coatings with different phase structures and a wide range of surface morphologies. In addition, substantial modification to the physical properties and catalytic activities of the coatings are possible through doping and the fabrication of nanostructured deposits or composites. In addition to applications as a cheap anode material in electrochemical technology, lead dioxide coatings provide unique possibilities for probing the dependence of catalytic activity on layer composition and structure (critical review, 256 references)
Single-molecule experiments in biological physics: methods and applications
I review single-molecule experiments (SME) in biological physics. Recent
technological developments have provided the tools to design and build
scientific instruments of high enough sensitivity and precision to manipulate
and visualize individual molecules and measure microscopic forces. Using SME it
is possible to: manipulate molecules one at a time and measure distributions
describing molecular properties; characterize the kinetics of biomolecular
reactions and; detect molecular intermediates. SME provide the additional
information about thermodynamics and kinetics of biomolecular processes. This
complements information obtained in traditional bulk assays. In SME it is also
possible to measure small energies and detect large Brownian deviations in
biomolecular reactions, thereby offering new methods and systems to scrutinize
the basic foundations of statistical mechanics. This review is written at a
very introductory level emphasizing the importance of SME to scientists
interested in knowing the common playground of ideas and the interdisciplinary
topics accessible by these techniques. The review discusses SME from an
experimental perspective, first exposing the most common experimental
methodologies and later presenting various molecular systems where such
techniques have been applied. I briefly discuss experimental techniques such as
atomic-force microscopy (AFM), laser optical tweezers (LOT), magnetic tweezers
(MT), biomembrane force probe (BFP) and single-molecule fluorescence (SMF). I
then present several applications of SME to the study of nucleic acids (DNA,
RNA and DNA condensation), proteins (protein-protein interactions, protein
folding and molecular motors). Finally, I discuss applications of SME to the
study of the nonequilibrium thermodynamics of small systems and the
experimental verification of fluctuation theorems. I conclude with a discussion
of open questions and future perspectives.Comment: Latex, 60 pages, 12 figures, Topical Review for J. Phys. C (Cond.
Matt
Can 'functionlaity' save the community management model of rural water supply?
As attention increasingly turns to the sustainability of rural water supplies - and not simply overall levels of coverage or access - water point functionality has become a core concern for development practitioners and national governments, especially in Sub-Saharan Africa. Within the long-enduring Community-Based Management (CBM) model this has resulted in increased scrutiny of the “functionality” of the local water point committee (WPC) or similar community management organisation. This paper reviews the literature written from both practice-focused and critical-academic perspectives and identifies three areas that pose challenges to our understanding of water point functionality as it relates to CBM. These concern the relative neglect of (i) the local institutional and socio-economic landscape, (ii) broader governance processes and power dynamics, and (iii) the socio-technical interface. By examining these three areas, the paper engages with the specific issue of WPC functionality, whilst also considering broader issues relating to the framing of problems in development and the methodological and disciplinary ways that these are addressed. Furthermore, by focusing on community management of rural water points, the paper lays the ground for a more substantial critique of the continuing persistence of the CBM model as a central development strategy
Mechanisms of impulsive choice: I. Individual differences in interval timing and reward processing
Impulsive choice behavior incorporates the psychological mechanisms involved in the
processing of the anticipated magnitude and delay until reward. The goal of the present
experiment was to determine whether individual differences in such processes related to
individual differences in impulsive choice behavior. Two groups of rats (Delay Group and
Magnitude Group) were initially exposed to an impulsive choice task with choices between smaller-sooner (SS) and larger-later (LL) rewards. The Delay Group was subsequently exposed to a temporal discrimination task followed by a progressive interval task, whereas the Magnitude Group was exposed to a reward magnitude sensitivity task followed by a progressive ratio task. Inter-task correlations revealed that the rats in the Delay Group that made more self-controlled (LL) choices also displayed lower standard deviations in the temporal bisection task and greater delay tolerance in the progressive interval task. Impulsive choice behavior in the Magnitude Group did not display any substantial correlations with the reward magnitude sensitivity and
progressive ratio tasks. The results indicate the importance of core timing processes in impulsive choice behavior, and encourage further research examining the effects of changes in core timing processes on impulsive choice
Transcription analysis on response of swine lung to H1N1 swine influenza virus
<p>Abstract</p> <p>Background</p> <p>As a mild, highly contagious, respiratory disease, swine influenza always damages the innate immune systems, and increases susceptibility to secondary infections which results in considerable morbidity and mortality in pigs. Nevertheless, the systematical host response of pigs to swine influenza virus infection remains largely unknown. To explore it, a time-course gene expression profiling was performed for comprehensive analysis of the global host response induced by H1N1 swine influenza virus in pigs.</p> <p>Results</p> <p>At the early stage of H1N1 swine virus infection, pigs were suffering mild respiratory symptoms and pathological changes. A total of 268 porcine genes showing differential expression (DE) after inoculation were identified to compare with the controls on day 3 post infection (PID) (Fold change ≥ 2, p < 0.05). The DE genes were involved in many vital functional classes, mainly including signal transduction, immune response, inflammatory response, cell adhesion and cell-cell signalling. Noticeably, the genes associated with immune and inflammatory response showed highly overexpressed. Through the pathway analysis, the significant pathways mainly concerned with Cell adhesion molecules, Cytokine-cytokine receptor interaction, Toll-like receptor signaling pathway and MAPK signaling pathway, suggesting that the host took different strategies to activate these pathways so as to prevent virus infections at the early stage. However, on PID 7, the predominant function classes of DE genes included signal transduction, metabolism, transcription, development and transport. Furthermore, the most significant pathways switched to PPAR signaling pathway and complement and coagulation cascades, showing that the host might start to repair excessive tissue damage by anti-inflammatory functions. These results on PID 7 demonstrated beneficial turnover for host to prevent excessive inflammatory damage and recover the normal state by activating these clusters of genes.</p> <p>Conclusions</p> <p>This study shows how the target organ responds to H1N1 swine influenza virus infection in pigs. The observed gene expression profile could help to screen the potential host agents for reducing the prevalence of swine influenza virus and further understand the molecular pathogenesis associated with H1N1 infection in pigs.</p
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