Exploring adaptation & self-adaptation in autonomic computing systems

This panel paper sets out to discuss what self-adaptation means, and to explore the extent to which current autonomic systems exhibit truly self-adaptive behaviour. Many of the currently cited examples are clearly adaptive, but debate remains as to what extent they are simply following prescribed adaptation rules within preset bounds, and to what extent they have the ability to truly learn new behaviour. Is there a standard test that can be applied to differentiate? Is adaptive behaviour sufficient anyway? Other autonomic computing issues are also discussed

3-D Photoionization Structure and Distances of Planetary Nebulae II. Menzel 1

We present the results of a spatio-kinematic study of the planetary nebula Menzel 1 using spectro-photometric mapping and a 3-D photoionization code. We create several 2-D emission line images from our long-slit spectra, and use these to derive the line fluxes for 15 lines, the Halpha/Hbeta extinction map, and the [SII] line ratio density map of the nebula. We use our photoionization code constrained by these data to derive the three-dimensional nebular structure and ionizing star parameters of Menzel 1 by simultaneously fitting the integrated line intensities, the density map, and the observed morphologies in several lines, as well as the velocity structure. Using theoretical evolutionary tracks of intermediate and low mass stars, we derive a mass for the central star of 0.63+-0.05 Msolar. We also derive a distance of 1050+_150 pc to Menzel 1.Comment: To be published in ApJ of 10th February 2005. 12 figure

A Systems Approach for Management of Pests and Pathogens of Nursery Crops

Horticultural nurseries are heterogeneous and spatially complex agricultural systems, which present formidable challenges to management of diseases and pests. Moreover, nursery plants shipped interstate and internationally can serve as important vectors for pathogens and pests that threaten both agriculture and forestry. Current regulatory strategies to prevent this movement of pathogens and pests with nursery plants are based on visual inspections of plants just before shipping, a process that is costly and inadequate. Here we propose the application of a systems approach for horticultural nurseries modeled after the Hazard Analysis of Critical Control Points (HACCP) approach widely used in the food processing industry. We evaluated aspects of the systems approach to analyze contamination hazards by Phytophthora species and then implemented management practices targeting specific critical control points. The systems approach for analyzing and correcting unsafe practices offers a potential alternative strategy for preventing plant contamination that could be broadly applied to many pests and pathogens. One of the hallmarks of this approach is its flexibility, including the ability to improve and adapt the approaches as new technologies are developed or improved and to provide the grower with management options

Seven-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Power Spectra and WMAP-Derived Parameters

(Abridged) We present the angular power spectra derived from the 7-year maps and discuss the cosmological conclusions that can be inferred from WMAP data alone. The third acoustic peak in the TT spectrum is now well measured by WMAP. In the context of a flat LambdaCDM model, this improvement allows us to place tighter constraints on the matter density from WMAP data alone, and on the epoch of matter-radiation equality, The temperature-polarization (TE) spectrum is detected in the 7-year data with a significance of 20 sigma, compared to 13 sigma with the 5-year data. The low-l EE spectrum, a measure of the optical depth due to reionization, is detected at 5.5 sigma significance when averaged over l = 2-7. The BB spectrum, an important probe of gravitational waves from inflation, remains consistent with zero. The upper limit on tensor modes from polarization data alone is a factor of 2 lower with the 7-year data than it was using the 5-year data (Komatsu et al. 2010). We test the parameter recovery process for bias and find that the scalar spectral index, ns, is biased high, but only by 0.09 sigma, while the remaining parameters are biased by < 0.15 sigma. The improvement in the third peak measurement leads to tighter lower limits from WMAP on the number of relativistic degrees of freedom (e.g., neutrinos) in the early universe: Neff > 2.7 (95% CL). Also, using WMAP data alone, the primordial helium mass fraction is found to be YHe = 0.28+0.14-0.15, and with data from higher-resolution CMB experiments included, we now establish the existence of pre-stellar helium at > 3 sigma (Komatsu et al. 2010).Comment: 22 pages, 14 figures, version accepted to Astrophysical Journal Supplement Series, added high-l EE detection, consolidated parameter recovery simulation

Are He and N Abundances in Type I PNe as High as Empirically Derived?

Type I planetary nebulae (PNe) are defined as those with high He and N abundances (Peimbert & Torres-Peimbert 1983). These objects present in general bipolar geometries and have high stellar temperatures (Corradi & Schwarz 1995, Torres-Peimbert & Peimbert 1997). In this paper we analyse the empirical methods for abundance determination in order to check if the He and N overabundances in Type I PNe are a consequence of a geometrical effect, due to the bipolarity, or the ionization stratification, due to the stellar temperature. For this, we obtain simulated spherically symmetrical as well as bipolar nebulae, using a 3D photoionization code. From the projected emission line intensities for: a) the whole nebula; b) for a slit crossing the nebula; as well as c) for different positions in the nebula, we applied the formulae used in the literature to obtain empirical abundances. These empirical abundances are then compared with the adopted ones. We show that empirical abundances depend on the particular line of sight covered by the observation and can simulate an overabundance and/or the presence of abundance gradients of He and N in planetary nebulae with high stellar temperature. The geometrical effects are also discussed. Systematic errors in abundance determinations by empirical methods are higher for the N/H ratio than for N/O. Thus, it seems better to use the N/O value when discussing N rich objects.Comment: 19 pages, 5 figures, aastex package, to be published at Ap.

From (p)reheating to nucleosynthesis

This article gives a brief qualitative description of the possible evolution of the early Universe between the end of an inflationary epoch and the end of Big Bang nucleosynthesis. After a general introduction, establishing the minimum requirements cosmologists impose on this cosmic evolutionary phase, namely, successful baryogenesis, the production of cosmic dark matter, and successful light-element nucleosynthesis, a more detailed discussion on some recent developments follows. This latter includes the physics of preheating, the putative production of (alternative) dark matter, and the current status of Big Bang nucleosynthesis.Comment: 18 pages, 6 figures, to be published in "Classical and Quantum Gravity", article based on a talk presented at ``The Early Universe and Cosmological Observations: a Critical Review'', Cape Town, July 200

Environmental and Economically Conscious Magnesium Production: Solar Thermal Electrolytic Production of Mg from MgO

One method to improve the fuel efficiency of American made vehicles is to reduce vehicle weight by substituting steel components with lighter magnesium (Mg) components. Unfortunately, U.S. produced Mg currently costs approximately $3.31 per kg, over seven times the price of steel. Furthermore, Mg production has a staggering energy and environmental impact, consuming up to 102 kW-hr/kg-Mg of energy and producing 36 kg of CO2/kg-Mg. To reduce the overwhelming economic and environmental impact of Mg, a new solar thermal electrolytic process has been developed for the production of Mg from MgO. Through this process, liquid Mg is produced in a solar reactor utilizing both thermal and electrical energy. At elevated temperatures, the thermal energy from concentrated sunlight reduces the required electrical work below that of current processes. The reactor absorbs the concentrated solar energy, heating a molten salt-MgO mixture in an electrolytic cell. Electricity is then supplied to the cell, producing liquid Mg and CO. It is estimated that this new process will produce Mg at$2.50 per kg, with costs decreasing as the technology is further developed. This process requires approximately 8.3 kW-hr/kg-Mg of energy and produces only 3.44 kg of CO2/kg-Mg, large reductions compared to current processes

Health promoting potential of herbal teas and tinctures from Artemisia campestris subsp maritima: from traditional remedies to prospective products

This work explored the biotechnological potential of the medicinal halophyte Artemisia campestris subsp. maritima (dune wormwood) as a source of health promoting commodities. For that purpose, infusions, decoctions and tinctures were prepared from roots and aerial-organs and evaluated for in vitro antioxidant, anti-diabetic and tyrosinase-inhibitory potential, and also for polyphenolic and mineral contents and toxicity. The dune wormwood extracts had high polyphenolic content and several phenolics were identified by ultra-high performance liquid chromatography-photodiode array-mass-spectrometry (UHPLC-PDA-MS). The main compounds were quinic, chlorogenic and caffeic acids, coumarin sulfates and dicaffeoylquinic acids; several of the identified phytoconstituents are here firstly reported in this A. campestris subspecies. Results obtained with this plant's extracts point to nutritional applications as mineral supplementary source, safe for human consumption, as suggested by the moderate to low toxicity of the extracts towards mammalian cell lines. The dune wormwood extracts had in general high antioxidant activity and also the capacity to inhibit a-glucosidase and tyrosinase. In summary, dune wormwood extracts are a significant source of polyphenolic and mineral constituents, antioxidants and a-glucosidase and tyrosinase inhibitors, and thus, relevant for different commercial segments like the pharmaceutical, cosmetic and/or food industries.FCT - Foundation for Science and Technology [CCMAR/Multi/04326/2013]; Portuguese National Budget; FCT [IF/00049/2012, SFRH/BD/94407/2013]; Research Foundation - Flanders (FWO) [12M8315N]info:eu-repo/semantics/publishedVersio