169 research outputs found
A Generic Agent Organisation Framework For Autonomic Systems
Autonomic computing is being advocated as a tool for managing large, complex computing systems. Specifically, self-organisation provides a suitable approach for developing such autonomic systems by incorporating self-management and adaptation properties into large-scale distributed systems. To aid in this development, this paper details a generic problem-solving agent organisation framework that can act as a modelling and simulation platform for autonomic systems. Our framework describes a set of service-providing agents accomplishing tasks through social interactions in dynamically changing organisations. We particularly focus on the organisational structure as it can be used as the basis for the design, development and evaluation of generic algorithms for self-organisation and other approaches towards autonomic systems
Differential localization of GABAA receptor subunits in relation to rat striatopallidal and pallidopallidal synapses
As a central integrator of basal ganglia function, the external segment of the globus pallidus (GP) plays a critical role in the control of voluntary movement. The GP is composed of a network of inhibitory GABA-containing projection neurons which receive GABAergic input from axons of the striatum (Str) and local collaterals of GP neurons. Here, using electrophysiological techniques and immunofluorescent labeling we have investigated the differential cellular distribution of a1, a2 and a3 GABAA receptor subunits in relation to striatopallidal (Str-GP) and pallidopallidal (GP-GP) synapses. Electrophysiological investigations showed that zolpidem (100 nm; selective for the a1 subunit) increased the amplitude and the decay time of both Str-GP and GP-GP IPSCs, indicating the presence of the a1 subunits at both synapses. However, the application of drugs selective for the a2, a3 and a5 subunits (zolpidem at 400 nm, L-838,417 and TP003) revealed differential effects on amplitude and decay time of IPSCs, suggesting the nonuniform distribution of non-a1 subunits. Immunofluorescence revealed widespread distribution of the a1 subunit at both soma and dendrites, while double- and triple-immunofluorescent labeling for parvalbumin, enkephalin, gephyrin and the ?2 subunit indicated strong immunoreactivity for GABAAa3 subunits in perisomatic synapses, a region mainly targeted by local axon collaterals. In contrast, immunoreactivity for synaptic GABAAa2 subunits was observed in dendritic compartments where striatal synapses are preferentially located. Due to the kinetic properties which each GABAAa subunit confers, this distribution is likely to contribute differentially to both physiological and pathological patterns of activity
Microbial Fuel Cells Applied to the Metabolically-Based Detection of Extraterrestrial Life
Since the 1970's, when the Viking spacecrafts carried out experiments aimed
to the detection of microbial metabolism on the surface of Mars, the search for
nonspecific methods to detect life in situ has been one of the goals of
astrobiology. It is usually required that the methodology can detect life
independently from its composition or form, and that the chosen biological
signature points to a feature common to all living systems, as the presence of
metabolism. In this paper we evaluate the use of Microbial Fuel Cells (MFCs)
for the detection of microbial life in situ. MFCs are electrochemical devices
originally developed as power electrical sources, and can be described as fuel
cells in which the anode is submerged in a medium that contains microorganisms.
These microorganisms, as part of their metabolic process, oxidize organic
material releasing electrons that contribute to the electric current, which is
therefore proportional to metabolic and other redox processes. We show that
power and current density values measured in MFCs using microorganism cultures
or soil samples in the anode are much larger than those obtained using a medium
free of microorganisms or sterilized soil samples, respectively. In particular,
we found that this is true for extremophiles, usually proposed to live in
extraterrestrial environments. Therefore, our results show that MFCs have the
potential to be used to detect microbial life in situ.Comment: To be published in Astrobiolog
Knuth-Bendix algorithm and the conjugacy problems in monoids
We present an algorithmic approach to the conjugacy problems in monoids,
using rewriting systems. We extend the classical theory of rewriting developed
by Knuth and Bendix to a rewriting that takes into account the cyclic
conjugates.Comment: This is a new version of the paper 'The conjugacy problems in monoids
and semigroups'. This version will appear in the journal 'Semigroup forum
Characterization of Avian Influenza Viruses A (H5N1) from Wild Birds, Hong Kong, 2004–2008
Repeated detection of subclade 2.3.2 viruses in nonpasserine birds from different regions suggests possible establishment of this lineage in wild bird species
Unlocking the transcriptomic potential of formalin-fixed paraffin embedded clinical tissues: Comparison of gene expression profiling approaches
Background: High-throughput transcriptomics has matured into a very well established and widely utilised research tool over the last two decades. Clinical datasets generated on a range of different platforms continue to be deposited in public repositories provide an ever-growing, valuable resource for reanalysis. Cost and tissue availability normally preclude processing samples across multiple technologies, making it challenging to directly evaluate performance and whether data from different platforms can be reliably compared or integrated. Methods: This study describes our experiences of nine new and established mRNA profiling techniques including Lexogen QuantSeq, Qiagen QiaSeq, BioSpyder TempO-Seq, Ion AmpliSeq, Nanostring, Affymetrix Clariom S or U133A, Illumina BeadChip and RNA-seq of formalin-fixed paraffin embedded (FFPE) and fresh frozen (FF) sequential patient-matched breast tumour samples. Results: The number of genes represented and reliability varied between the platforms, but overall all methods provided data which were largely comparable. Crucially we found that it is possible to integrate data for combined analyses across FFPE/FF and platforms using established batch correction methods as required to increase cohort sizes. However, some platforms appear to be better suited to FFPE samples, particularly archival material. Conclusions: Overall, we illustrate that technology selection is a balance between required resolution, sample quality, availability and cost
Potential for comparative public opinion research in public administration
The public administration and public services have always taken a
marginal place in the political scientists’ behavioural research.
Public administration students on the other hand tend to focus on
political and administrative elites and institutions, and largely
ignored citizens in comparative research. In this article we make a
plea for international comparative research on citizens’ attitudes
towards the public administration from an interdisciplinary
perspective. Available international survey material is discussed, and
main trends in empirical practice and theoretical approaches are
outlined, especially those with a potential impact on public sector
reform
The effect of autonomy, training opportunities, age and salaries on job satisfaction in the South East Asian retail petroleum industry
South East Asian petroleum retailers are under considerable pressure to improve service quality by reducing turnover. An empirical methodology from this industry determined the extent to which job characteristics, training opportunities, age and salary influenced the level of job satisfaction, an indicator of turnover. Responses are reported on a random sample of 165 site employees (a 68% response rate) of a Singaporean retail petroleum firm. A restricted multivariate regression model of autonomy and training opportunities explained the majority (35.4%) of the variability of job satisfaction. Age did not moderate these relationships, except for employees >21 years of age, who reported enhanced job satisfaction with additional salary. Human Capital theory, Life Cycle theory and Job Enrichment theory are invoked and explored in the context of these findings in the South East Asian retail petroleum industry. In the South East Asian retail petroleum industry, jobs providing employees with the opportunity to undertake a variety of tasks that enhanced the experienced meaningfulness of work are likely to promote job satisfaction, reduce turnover and increase the quality of service
Animal-based agriculture, phosphorus management and water quality in Brazil: options for the future
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