Two-Timescale Learning Using Idiotypic Behaviour Mediation For A Navigating Mobile Robot

A combined Short-Term Learning (STL) and Long-Term Learning (LTL) approach to solving mobile-robot navigation problems is presented and tested in both the real and virtual domains. The LTL phase consists of rapid simulations that use a Genetic Algorithm to derive diverse sets of behaviours, encoded as variable sets of attributes, and the STL phase is an idiotypic Artificial Immune System. Results from the LTL phase show that sets of behaviours develop very rapidly, and significantly greater diversity is obtained when multiple autonomous populations are used, rather than a single one. The architecture is assessed under various scenarios, including removal of the LTL phase and switching off the idiotypic mechanism in the STL phase. The comparisons provide substantial evidence that the best option is the inclusion of both the LTL phase and the idiotypic system. In addition, this paper shows that structurally different environments can be used for the two phases without compromising transferability.Comment: 40 pages, 12 tables, Journal of Applied Soft Computin

Role of the chemokines CCL3/MIP-1α and CCL5/RANTES in sponge-induced inflammatory angiogenesis in mice

Barcelos, Luciola S Coelho, Amanda M Russo, Remo C Guabiraba, Rodrigo Souza, Adriano L S Bruno-Lima, Guilherme Jr Proudfoot, Amanda E I Andrade, Silvia P Teixeira, Mauro M Microvasc Res. 2009 Sep;78(2):148-54. doi: 10.1016/j.mvr.2009.04.009. Epub 2009 May 8.; International audience; OBJECTIVE: We examined the potential contribution of CCL3 and CCL5 to inflammatory angiogenesis in mice. METHODS: Polyester-polyurethane sponges were implanted in mice and blood vessel counting and hemoglobin, myeloperoxidase and N-acetylglucosaminidase measurements used as indexes for vascularization, neutrophil and macrophage accumulation, respectively. RESULTS: CCL3 and CCL5 were expressed throughout the observation period. Exogenous CCL3 enhanced angiogenesis in WT, but angiogenesis proceeded normally in CCL3(-/-) mice, suggesting that endogenous CCL3 is not critical for sponge-induced angiogenesis in mice. CCL5 expression was detected at day 1, but levels significantly increased thereafter. Exogenous CCL5 reduced angiogenesis in WT mice possible via CCR5 as CCL5 was without an effect in CCR5(-/-) mice. Treatment of WT with the CCR1/CCR5 antagonist, Met-RANTES, prevented neutrophil and macrophage accumulation, but enhanced sponge vascularization. CONCLUSION: Thus, endogenous CCL3 appears not to play a role in driving sponge-induced inflammatory angiogenesis in mice. The effects of CCL5 were anti-angiogenic and appeared to be mediated via activation of CCR5

Modulated-laser source induction system for remote detection of infrared emissions of high explosives using laser-induced thermal emission

In a homeland security setting, the ability to detect explosives at a distance is a top security priority. Consequently, the development of remote, noncontact detection systems continues to represent a path forward. In this vein, a remote detection system for excitation of infrared emissions using a CO2 laser for generating laser-induced thermal emission (LITE) is a possible solution. However, a LITE system using a CO2 laser has certain limitations, such as the requirement of careful alignment, interference by the CO2 signal during detection, and the power density loss due to the increase of the laser image at the sample plane with the detection distance. A remote chopped-laser induction system for LITE detection using a CO2 laser source coupled to a focusing telescope was built to solve some of these limitations. Samples of fixed surface concentration (500 μg∕cm2) of 1,3,5-trinitroperhydro-1,3,5-triazine (RDX) were used for the remote detection experiments at distances ranging between 4 and 8 m. This system was capable of thermally exciting and capturing the thermal emissions (TEs) at different times in a cyclic manner by a Fourier transform infrared (FTIR) spectrometer coupled to a gold-coated reflection optics telescope (FTIR-GT). This was done using a wheel blocking the capture of TE by the FTIR-GT chopper while heating the sample with the CO2 laser. As the wheel moved, it blocked the CO2 laser and allowed the spectroscopic system to capture the TEs of RDX. Different periods (or frequencies) of wheel spin and FTIR-GT integration times were evaluated to find dependence with observation distance of the maximum intensity detection, minimum signal-to-noise ratio, CO2 laser spot size increase, and the induced temperature incremen

EcoCyc: fusing model organism databases with systems biology.

EcoCyc (http://EcoCyc.org) is a model organism database built on the genome sequence of Escherichia coli K-12 MG1655. Expert manual curation of the functions of individual E. coli gene products in EcoCyc has been based on information found in the experimental literature for E. coli K-12-derived strains. Updates to EcoCyc content continue to improve the comprehensive picture of E. coli biology. The utility of EcoCyc is enhanced by new tools available on the EcoCyc web site, and the development of EcoCyc as a teaching tool is increasing the impact of the knowledge collected in EcoCyc

Dexterity test data contribute to reduction in leaded glovebox gloves use

Programmatic operations at the Los Alamos National Laboratory Plutonium Facility (T A-55) involve working with various amounts of plutonium and other highly toxic, alpha-emitting materials. The spread of radiological contamination on surfaces, airborne contamination, and excursions of contaminants into the operator's breathing zone are prevented through the use of a variety of gloveboxes. Using an integrated approach, controls have been developed and implemented through an efficient Glovebox Glove Integrity Program. A key element of this program is to consider measures that lower the overall risk of glovebox operations. Line management who own glovebox processes through this program make decisions on which type of glovebox gloves (hereafter referred to as gloves), the weakest component of this safety-significant system, would perform best in these aggressive environments. As Low as Reasonably Achievable considerations must be balanced with glove durability and worker dexterity, both of which affect the final overall risk of the operation. In the past, lead-loaded (leaded) gloves made from Hypalon(reg.) were the primary glove for programmatic operations at TA55. Replacing leaded gloves with unleaded gloves for certain operations would lower the overall risk as well as reduce the amount of mixed transuranic waste. This effort contributes to the Los Alamos National Laboratory Continuous Improvement Program by improving the efficiency, cost-effectiveness, and formality of glovebox operations. In this report, the pros and cons of wearing leaded gloves, the effect of leaded gloves versus unleaded gloves on task performance using standard dexterity tests, the justification for switching from leaded to unleaded gloves, and the pollution prevention benefits of this dramatic change in the glovebox system are presented

Mid-Infrared Laser Spectroscopy Applications I: Detection of Traces of High Explosives on Reflective and Matte Substrates

Mid-infrared (MIR) lasers have revolutionized infrared vibrational spectroscopy, converting an already dominant spectroscopic analysis technique into an even more powerful, easier to use, and quicker turn-around cadre of versatile spectroscopic tools. A selection of applications, revisited under the umbrella of MIR laser-based properties, very high brightness, collimated beams, polarized sources, highly monochromatic tunable sources, and coherent sources, is included. Applications discussed concern enhanced detection, discrimination, and quantification of high explosives (HEs). From reflectance measurements of chemical residues on highly reflective metallic substrates to reflectance measurements of HEs deposited on non-reflective, matte substrates is discussed. Coupling with multivariate analyses (MVA) techniques of Chemometrics allowed near trace detection of HEs, with sharp discrimination from highly MIR absorbing substrates

HIP 10725: The first solar twin/analogue field blue straggler

Context. Blue stragglers are easy to identify in globular clusters, but are much harder to identify in the field. Here we present the serendipitous discovery of one field blue straggler, HIP 10725, that closely matches the Sun in mass and age, but with a metallicity slightly lower than solar. Aims. We characterise the solar twin/analogue HIP 10725 to assess whether this star is a blue straggler. Methods. We employed spectra with high resolution (R ~ 105) and high signal-to-noise ratio (330) obtained with UVES at the VLT to perform a differential abundance analysis of the solar analogue HIP 10725. Radial velocities obtained by other instruments were also used to check for binarity. We also studied its chromospheric activity, age, and rotational velocity. Results. HIP 10725 is severely depleted in beryllium ([ Be/H ] ≤ −1.2 dex) for its stellar parameters and age. The abundances relative to solar of the elements with Z ≤ 30 show a correlation with condensation temperature, and the neutron capture elements produced by the s-process are greatly enhanced, while the r-process elements seem normal. We found its projected rotational velocity (vsini = 3.3 ± 0.1 km s-1) to be significantly higher than solar and incompatible with its isochrone-derived age. Radial velocity monitoring shows that the star has a binary companion. Conclusions. Based on the high s-process element enhancements and low beryllium abundance, we suggest that HIP 10725 has been polluted by mass transfer from an AGB star that probably had an initial mass of about 2 M⊙. The radial velocity variations suggest the presence of an unseen binary companion, probably the remnant of a former AGB star. Isochrones predict a solar-age star, but this disagrees with the high projected rotational velocity and high chromospheric activity. We conclude that HIP 10725 is a field blue straggler, rejuvenated by the mass-transfer process of its former AGB companion