Pal

The objective of the current research is to improve the localization accuracy of a mobile robot during its navigation in known environment. The robot uses GPS receiver to rough positioning. To determine more accurate location panoramic annual image of the omnidirectional imaging tool mounted on the CCExplorer robot is processed continuously. The applied software library algorithm [3] lets us compute optical flow based on the Lucas-Kanade feature tracker in real time. The optical flow computation is implemented in pyramidal fashion, from coarse to fine resolution. Consequently, the algorithm can handle large pixel flows, while keeping a relatively small window of integration, and therefore achieve high local accuracy (of the order of 0.1 pixel). The paper summarizes the features of the PAL imaging tool, the applied computer vision method adapted to panoramic image and the results of the navigation experiment.

Among the family of pulse time modulation (PTM) techniques, square wave frequency modulation (SWFM) is particularly well suited to the transmission of high-quality wideband instrumentation and video signals such as MAC and high definition TV over optical fibres due to its attractive combination of performance and simplicity. This paper discusses aspects of SWFM and describes two experimental systems employing novel demodulators suitable for 5.5 MHz (PAL) and 12 MHz wide format MAC bandwidth systems respectively. >

Plant secondary metabolites are unique sources for pharmaceuticals, food additives, flavors, and other industrial materials. Accumulation of such metabolites often occurs in plants subjected to stresses including various elicitors or signal molecules. Understanding signal transduction paths underlying elicitor-induced production of secondary metabolites is important for optimizing their commercial production. This paper summarizes progress made on several aspects of elicitor signal transduction leading to production of plant secondary metabolites, including: elicitor signal perception by various receptors of plants; avirulence determinants and corresponding plant R proteins; heterotrimeric and small GTP binding proteins; ion fluxes, especially Ca2+ influx, and Ca2+ signaling; medium alkalinization and cytoplasmic acidification; oxidative burst and reactive oxygen species; inositol trisphosphates and cyclic nucleotides (cAMP and cGMP); salicylic acid and nitric oxide; jasmonate, ethylene, and abscisic acid signaling; oxylipin signals such as allene oxide synthase-dependent jasmonate and hydroperoxide lyase-dependent C12 and C6 volatiles; as well as other lipid messengers such as lysophosphatidylcholine, phosphatidic acid, and diacylglycerol. All these signal components are employed directly or indirectly by elicitors for induction of plant secondary metabolite accumulation. Cross-talk between different signaling pathways is very common in plant defense response, thus the cross-talk amongst these signaling pathways, such as elicitor and jasmonate, jasmonate and ethylene, and each of these with reactive oxygen species, is discussed separately. This review also highlights the integration of multiple signaling pathways into or by transcription factors, as well as the linkage of the above signal components in elicitor signaling network through protein phosphorylation and dephosphorylation. Some perspectives on elicitor signal transduction and plant secondary metabolism at the transcriptome and metabolome levels are also presented.

A hypothetical lateritic nickel deposit of median size was defined using data from a number of deposits under development and implementation. Production plans for a pressure acid leach operation were developed using industry parameters. Capacities between 45000 t/year Ni and 300000 t/year Ni were studied, leading to a set of technical parameters, used for capacity assessment.

Nitric oxide (NO) is a bioactive molecule, which in plants was found to function as prooxidant as well as antioxidant. In the present study, we found that NO donor sodium nitroprusside (SNP) stimulates seed germination and root growth of lupin (Lupinus luteus L. cv. Ventus). Seed germination is promoted at concentrations between 0.1 and 800 μM SNP in a dose-dependent manner. The stimulation was most pronounced after 18 and 24 h and ceased after 48 h of imbibition. The promoting effect of NO on seed germination persisted even in the presence of heavy metals (Pb, Cd) and sodium chloride. Pretreatment of lupin seedlings for 24 h with 10 μM SNP resulted in efficient reduction of the detrimental effect of the abiotic stressors on root growth and morphology. The inhibitory effect of heavy metals on root growth was accompanied by increased activity of superoxide dismutase (SOD, EC 1.15.1.1.), which in roots preincubated with SNP was significantly higher. Some changes in the activity of oth...

Physiological and molecular mechanisms underlying quantitative resistance of plants to pathogens are still poorly understood, but could depend upon differences in the intensity or timing of general defense responses. This may be the case for the biosynthesis of phenolics which are known to increase after elicitation by pathogens. We thus tested the hypothesis that differences in quantitative resistance were related to differential induction of phenolics by pathogen-derived elicitors. Five potato cultivars (Solanum tuberosum, L.) spanning a range of quantitative resistance were treated with a concentrated culture filtrate (CCF) of Phytophthora infestans or purified lipopolysaccharides (LPS) from Pectobacterium atrosepticum. The kinetic of phenolics accumulation was followed and a set of typical phenolics was identified: chlorogenic acid, phenolamides and flavonols including rutin (quercetin-3-O-rutinoside) and nicotiflorin (kaempferol-3-O-rutinoside). Our results showed that CCF but ...

This paper brings a comparative analysis of cooperation initiatives between Latin American media, both past and present, taking as case study the Grupo de Diarios América (GDA), the Periódicos Asociados Latinoamericanos (PAL) and the Latin American Union of News Agencies (ULAN). Besides news exchange, these entities also act to bring in earnings in foreign exchange by enticing advertising from abroad (especially the USA), to reduce operating costs and to converge political articulation toward governments and public opinion. They became regional players in the media industry, opening channels and information flows between Latin American countries, one way or another. However, the comparisons show two different views about what kind of integration is sought by each: either the superficial integration of markets and flows of capital or the effective integration of societies, cultures and citizen participation in the process of change. As basis for this, one can recognise strategies for struggle for disputing hegemony in the region: on the one hand, media conglomerates, associated with big corporations; on the other, the State, particularly the countries adhering to the "Turn to the Left", through its public agencies, recently founded or overhauled under programs of national development.

Ginseng rusty root, a disorder of unknown cause (s), in which reddish-brown to orange-brown areas develop on the surface of field-grown roots, was studied at the cellular and biochemical levels. Using light microscopy, the affected areas were shown to comprise of the epidermis and underlying 6-8 cell layers of the cortical tissues. Rusty root areas ranged from small clusters of 3-4 cells to larger expanding areas of >80 cells. These cells appeared golden-brown and stained a bluish-green with Toluidine Blue indicating the presence of phenolic compounds. Energy-dispersive X-ray spectroscopy and atomic emission spectrometry of affected epidermal cells revealed a significant accumulation of Fe, Al, Si, Mg and other cations when compared to adjoining healthy cells. The concentrations of the six most common ginsenosides found in ginseng roots (Rg(1), Re, Rb(1), Rc, Rb(2), and Rd) were reduced by 40-50% in rusty root-affected epidermal and cortical tissues when compared to adjacent healthy tissues. Total phenolic compounds were increased by up to threefold in affected tissues and HPLC analysis revealed significantly higher levels of quercetin, cinnamic acid, vanillic acid, p-coumaric acid, benzoic acid, chlorogenic acid and catechin. In vitro phenolic-metal binding assays confirmed that phenolic compounds were able to sequester positively-charged metal ions, in particular Fe, to form a phenolic-metal ion complex. In ginseng callus cultures, accumulation of phenolic compounds was increased threefold within 12 h of treatment with chitosan (1%), and to a lesser extent by wounding. Specific defense enzymes, namely phenylalanine ammonia-lyase (PAL, E.C. 4. 3. 1. 5.), polyphenoloxidase (PPO, E.C. 1. 10. 3. 1.) and peroxidase (POD, E.C. 1. 11. 1. 7.), were also significantly enhanced in treated callus tissues and in rusty root tissues. On field-grown ginseng roots, application of chitosan induced symptoms similar to rusty root, whereas wounding and ethylene treatments did not. Based on these results, rusty root symptoms on ginseng are proposed to result from an induction of host defense responses, especially phenolic production, in epidermal and underlying cortical cells. This induction is likely due to attempted invasion by as-yet uncharacterized chitin-containing soil fungi, which were observed in many of the affected cells. Subsequent oxidation of phenolic compounds and sequestration of metal ions, in particular Fe, appear to be largely responsible for the symptoms observed.

Ginseng rusty root, a disorder of unknown cause (s), in which reddish-brown to orange-brown areas develop on the surface of field-grown roots, was studied at the cellular and biochemical levels. Using light microscopy, the affected areas were shown to comprise of the epidermis and underlying 6–8 cell layers of the cortical tissues. Rusty root areas ranged from small clusters of

This study explored the level of infection caused by different inoculum concentrations (102, 103, and 104 zoospores mL-1) of Phytophthora capsici in 3 pepper cultivars at days 2, 4, and 6. The effect that the infection induced on the peroxidase (POX), catalase (CAT), and phenolics of resistant and sensitive seedlings, as well as the defense mechanism against the pathogen, were also investigated. The resistance of PM-702 against the isolate used was high, whereas KM-Hot and DEM-8 displayed sensitive reactions. As a result of analyses of the leaves and stems from the 3 pepper cultivars, important changes in biochemical parameters were observed between resistant and sensitive cultivars after inoculation with the root rot pathogen P. capsici. The maximum increase of POX and CAT was observed in the resistant PM-702 cultivar. However, with a high inoculum concentration (104 zoospores mL-1), a loss of CAT activity was determined, especially in susceptible cultivars. The maximum increase in...

Peptidyl α-hydroxylating monooxygenase (PHM) functions in vivo towards the biosynthesis of α-amidated peptide hormones in mammals and insects. PHM is a potential target for the development of inhibitors as drugs for the treatment of human disease and as insecticides for the management of insect pests. We show here that relatively simple ground state analogs of the PHM substrate hippuric acid (C6H5–CO–NH–CH2–COOH) inhibit the enzyme with Ki values as low as 0.5 μM. Substitution of sulfur atom(s) into the hippuric acid analog increases the affinity of PHM for the inhibitor. Replacement of the acetylglycine moiety, –CO–NH–CH2–COOH with an S-(thioacetyl)thioglycolic acid moiety, –CS–S–CH2–COOH, yields compounds with the highest PHM affinity. Both S-(2-phenylthioacetyl)thioglycolate and S-(4-ethylthiobenzoyl)thioglycolic acid inhibit the proliferation of cultured human prostate cancer cells at concentrations >100-fold excess of their respective Ki values. Comparison of Ki values between mammalian PHM and insect PHM shows differences in potency suggesting that a PHM-based insecticide with limited human toxicity can be developed.