Fixed Mode Elimination In Decentralized Control Systems Using Eigenvalue Sensitivities

The knowledge of fixed modes plays an important role in the design of decentralized controllers for large scale systems. An approach based on a parametric sensitivity of eigenvalues is proposed to select the information to be exchanged between control stations in order to eliminate decentralized fixed modes. The procedure is illustrated with an example. © 1990

Quasiparticle Interactions in Fractional Quantum Hall Systems: Justification of Different Hierarchy Schemes

The pseudopotentials describing the interactions of quasiparticles in fractional quantum Hall (FQH) states are studied. Rules for the identification of incompressible quantum fluid ground states are found, based upon the form of the pseudopotentials. States belonging to the Jain sequence nu=n/(1+2pn), where n and p are integers, appear to be the only incompressible states in the thermodynamic limit, although other FQH hierarchy states occur for finite size systems. This explains the success of the composite Fermion picture.Comment: RevTeX, 10 pages, 7 EPS figures, submitted fo Phys.Rev.

First Record Of Trophobiotic Interaction Between A Ponerine Ant And A Cicadelid Bug

The interactions of the ant Odontomachus bauri with nymphs of the sap-sucking bug Xedreota tuberculata (Cicadellidae: Ledrinae) were studied on Sipanea aff. (Rubiaceae) along a trail in an upland forest in the Ecological Reserve of Anavilhanas, AM, Brazil. Five complete interactions at day and at night (about 60 minutes) were analyzed. The care of cicadelid nymphs ranged between 12 and 961 seconds. © 2010 T. S. Souza and R. B. Francini.Holldobler, B., Wilson, E.O., (1990) The Ants, , Cambridge, UK The BelknapNovotny, V., Basset, Y., Auga, J., Boen, W., Dal, C., Drozd, P., Kasbal, M., Molem, K., Predation risk for herbivorous insects on tropical vegetation: A search for enemy-free space and time (1999) Australian Journal of Ecology, 24 (5), pp. 477-483Floren, A., Biun, A., Eduard Linsenmair, K., Arboreal ants as key predators in tropical lowland rainforest trees (2002) Oecologia, 131 (1), pp. 137-144. , DOI 10.1007/s00442-002-0874-zBronstein, J.L., The contribution of ant-plant protection studies to our understanding of mutualism (1998) Biotropica, 30 (2), pp. 150-161Buckley, R.C., Interactions involving plants, homoptera, and ants (1987) Annual Review of Ecology and Systematics, 18, pp. 111-135Davidson, D.W., McKey, D., The evolutionary ecology of symbiotic ant-plant relationships (1993) Journal of Hymenoptera Research, 2 (1), pp. 13-83Huxley, C.R., Cutler, D.F., (1991) Ant-Plant Interactions, , Oxford, UK Oxford University PressBentley, B.L., Extrafloral nectaries and protection by pugnacious bodygards (1977) Annual Review of Ecology and Systematics, 8, pp. 407-427Rico-Gray, V., Oliveira, P.S., (2007) The Ecology and Evolution of Ant-Plant Interactions, , Chicago, Ill, USA University Chicago PressO'Dowd, D.J., Pearl bodies as ant food: An ecological role for some leaf emergences of tropical plants (mutualisms) (1982) Biotropica, 14 (1), pp. 40-49Carroll, C.R., Janzen, D.H., Ecology of foraging by ants (1973) Annual Review of Ecology and Systematics, 4, pp. 231-257Gullan, P.J., Relationships with ants (1997) Soft Scale InsectsTheir Biology, Natural Enemies and Control, pp. 351-377. , Ben-Dov Y. Hodgson C. J. Amsterdam, The Netherlands Elsevier ScienceGullan, P.J., Kosztarab, M., Adaptations in scale insects (1997) Annual Review of Entomology, 42, pp. 23-50Delabie, J.H.C., Trophobiosis between formicidae and hemiptera (sternorrhyncha and auchenorrhyncha): An overview (2001) Neotropical Entomology, 30 (4), pp. 501-516Del-Claro, K., Oliveira, P.S., Ant-homoptera interactions in a neotropical savanna: The honeydew-producing treehopper, Guayaquila xiphias (Membracidae), and its associated ant fauna on Didymopanax vinosum (Araliaceae) (1999) Biotropica, 31 (1), pp. 135-144Del-Claro, K., Oliveira, P.S., Conditional outcomes in a neotropical treehopper-ant association: Temporal and species-specific variation in ant protection and homopteran fecundity (2000) Oecologia, 124 (2), pp. 156-165Blthgen, N., Verhaagh, M., Goita, W., Jaffé, K., Morawetz, W., Barthlott, W., How plants shape the ant community in the Amazonian rainforest canopy: The key role of extrafloral nectaries and homopteran honeydew (2000) Oecologia, 125 (2), pp. 229-240Delabie, J.H.C., Fernandez, F., Relaciones entre hormigas y homopteros (Hemiptera: Sternorrhyncha y Auchenorrhyncha) (2003) Introduccion A Las Hormigas de la Region Neotropical, pp. 181-197. , Fernandez F. Bogota, Colombia Instituto de Investigacion de Recursos Biologicos Alexander von HumboldtDavidson, D.W., Cook, S.C., Snelling, R.R., Liquid-feeding performances of ants (Formicidae): Ecological and evolutionary implications (2004) Oecologia, 139 (2), pp. 255-266. , DOI 10.1007/s00442-004-1508-4Del-Claro, K., Multitrophic relationships, conditional mutualisms, and the study of interaction biodiversity in tropical savannas (2004) Neotropical Entomology, 33 (6), pp. 665-672Weber, N.A., The Neotropical coccid-tending ants of the genus Acropyga Roger (1944) Annals of the Entomological Society of America, 37, pp. 89-122Way, M.J., Mutualism between ants and honeydew producing Homoptera (1963) Annual Review of Entomology, 8, pp. 307-344Wheeler, W.M., (1926) Ants. Their Structure, Development and Behavior, , New York, NY, USA Columbia University PressMittler, T.E., Studies on the feeding and nutrition of Tuberolachttus saligttus (Gmelin) 11. The nitrogen and sugar composition of ingested phloem and excreted honeydew (1958) Journal of Experimental Biology, 35, pp. 74-84Del-Claro, K., personal communicationBrown, W.L., Contributions toward a reclassification of the Formicidae. Part VI. Ponerinae, Tribe Ponerini, Subtribe Odontomachiti. Section A. Introduction, subtribal Characters, genus Odontomachu (1976) Studia Entomologica, 19 (14), pp. 67-171Longino, J.T., (2008) Ants of Costa Rica, , http://www.evergreen.eduKramer, J.P., A revision of the new world leafhoppers of the subfamily Ledrinae (Homoptera: Cicadellidae) (1966) Transactions of the American Entomological Society, 92 (3), pp. 469-502Dietrich, C.H., Keys to the families of Cicadomorpha and subfamilies and tribes of Cicadellidae (Hemiptera: Auchenorrhyncha) (2005) Florida Entomologist, 88 (4), pp. 502-517. , http://www.fcla.edu/FlaEnt/fe88p502.pdf, DOI 10.1653/0015-4040(2005)88[502:KTTFOC]2.0.CO;2Jones, J.R., Deitz, L.L., Phylogeny and systematics of the leafhopper subfamily Ledrinae (Hemiptera: Cicadellidae) (2009) Zootaxa, (2186), pp. 1-120Basset, Y., Springate, N.D., Elroy, C., Folivorous insects in the rainforests of the guianas (2005) Tropical Forests of the Guiana Shield, pp. 295-320. , Hammond D. S. CAB InternationalEvans, H.C., Leston, D., A Ponerine ant (Hym., Formicidae) associated with Homoptera on cocoa in Ghana (1971) Bulletin of Entomological Research, 61, pp. 357-362Myers, J.G., Observations on the biology of two remarkable cixiid plant-hoppers (Homoptera) from Cuba (1929) Psyche, 34 (4), pp. 283-292Weber, N.A., Two common ponerine ants of possible economic significance, Ectatomma tuberculatum (Olivier) and E. ruidum Roger (1946) Proceedings of the Entomological Society of Washington, 48, pp. 1-16Dietrich, C.H., McKamey, S.H., Three new idiocerine leafhopper (Homoptera: Cicadellidae) from Guyana with notes on ant-mutualism and subsociality (1990) Proceedings of the Entomological Society of Washington, 92, pp. 214-223Passos, L., Oliveira, P.S., Interactions between ants, fruits and seeds in a restinga forest in south-eastern Brazil (2003) Journal of Tropical Ecology, 19 (3), pp. 261-270. , DOI 10.1017/S026646740300329

Os sistemas agroflorestais como alternativa de sustentabilidade em ecossistemas de várzea no Amazonas.

Os sistemas agroflorestais (SAFs) representam uma alternativa agroecológica de produção, sob regime sustentável, para os agricultores familiares na várzea dos Rios Solimões/Amazonas, principalmente no que se refere ao manejo florestal, à diversidade de produtos e à geração de renda. Diante disso, o objetivo deste trabalho foi compreender as diferentes formas de apropriação e de manejo dos recursos naturais através dos SAFs, nos subsistemas roça, sítio e lagos, como componente para a sustentabilidade dos agricultores familiares da localidade Costa da Terra Nova, município do Careiro da Várzea, Amazonas. O método empregado foi o Estudo de Caso com aplicação de questionários, entrevistas e observação participante. A produção familiar na Costa da Terra Nova é representada pelos SAFs, constituído pelos os subsistemas: roça quintal e lago, que proporcionam produtos tanto para subsistência quanto para comercialização local, e estabelecendo a agricultura como fundamental atividade na localidade. O principal produto para comercialização é obtido das hortaliças cultivadas na época da vazante no subsistema roça nas comunidades São Francisco e Nossa Senhora da Conceição; e do extrativismo pesqueiro no subsistema lago, na época da cheia, principalmente na comunidade São José. A criação de animal se dá no subsistema sítio e é apenas para subsistência, sendo as aves e os suínos os principais animais domésticos criados nas três comunidades. Portanto os SAFs tradicionais, constituídos pelos subsistemas, roça, sitio e lago, são responsáveis pela sustentabilidade socioeconômica da localidade pesquisada, servindo, como alternativa agrícola melhor adaptada às condições locais das áreas de várzea na Amazônia

BB flavour tagging using charm decays at the LHCb experiment

An algorithm is described for tagging the flavour content at production of neutral $B$ mesons in the LHCb experiment. The algorithm exploits the correlation of the flavour of a $B$ meson with the charge of a reconstructed secondary charm hadron from the decay of the other $b$ hadron produced in the proton-proton collision. Charm hadron candidates are identified in a number of fully or partially reconstructed Cabibbo-favoured decay modes. The algorithm is calibrated on the self-tagged decay modes $B^+ \to J/\psi \, K^+$ and $B^0 \to J/\psi \, K^{*0}$ using $3.0\mathrm{\,fb}^{-1}$ of data collected by the LHCb experiment at $pp$ centre-of-mass energies of $7\mathrm{\,TeV}$ and $8\mathrm{\,TeV}$. Its tagging power on these samples of $B \to J/\psi \, X$ decays is $(0.30 \pm 0.01 \pm 0.01) \%$.Comment: All figures and tables, along with any supplementary material and additional information, are available at http://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2015-027.htm

Evidence for the strangeness-changing weak decay Ξb−→Λb0π−\Xi_b^-\to\Lambda_b^0\pi^-

Using a $pp$ collision data sample corresponding to an integrated luminosity of 3.0~fb$^{-1}$, collected by the LHCb detector, we present the first search for the strangeness-changing weak decay $\Xi_b^-\to\Lambda_b^0\pi^-$. No $b$ hadron decay of this type has been seen before. A signal for this decay, corresponding to a significance of 3.2 standard deviations, is reported. The relative rate is measured to be ${{f_{\Xi_b^-}}\over{f_{\Lambda_b^0}}}{\cal{B}}(\Xi_b^-\to\Lambda_b^0\pi^-) = (5.7\pm1.8^{+0.8}_{-0.9})\times10^{-4}$, where $f_{\Xi_b^-}$ and $f_{\Lambda_b^0}$ are the $b\to\Xi_b^-$ and $b\to\Lambda_b^0$ fragmentation fractions, and ${\cal{B}}(\Xi_b^-\to\Lambda_b^0\pi^-)$ is the branching fraction. Assuming $f_{\Xi_b^-}/f_{\Lambda_b^0}$ is bounded between 0.1 and 0.3, the branching fraction ${\cal{B}}(\Xi_b^-\to\Lambda_b^0\pi^-)$ would lie in the range from $(0.57\pm0.21)\%$ to $(0.19\pm0.07)\%$.Comment: 7 pages, 2 figures, All figures and tables, along with any supplementary material and additional information, are available at https://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2015-047.htm

Potassium acetate solution as a promising option to osmotic distillation for sour cherry (Prunus cerasus L.) juice concentration

Different osmotic agents (OA), such as potassium acetate (CH3COOK), potassium carbonate (K2CO3) and ammonium nitrate (NH4NO3), have been examined as alternatives to the traditionally used calcium chloride (CaCl2) for osmotic distillation concentrating of clarified and pre-concentrated sour cherry (Prunus cerasus L.) juice. Comparison of the process performances based on the permeate fluxes has been carried out. Regarding the permeate flux results, simplified estimation of the overall mass transfer coefficient of the most effective osmotic agent and the reference (CaCl2) solution has been also performed. Furthermore, analytical methods such as total antioxidant activity (TAA) and total polyphenolic content (TPC) using spectrophotometric assays have been also carried out to evaluate the effect of the osmotic distillation on the valuable compounds content of concentrated sour cherry juice. CH3COOK was found to be the most effective, resulted more than 25% higher permeate flux during the sour cherry juice concentration. K2CO3 and NH4NO3 were less effective. The simplified mass transfer estimation showed that the CH3COOK is more effective only at near saturated concentrations compared to the CaCl2. Regarding the TAA and TPC contents, a significant loss was found in case of all OAs during the concentration procedures

Screening, production and biochemical characterization of a new fibrinolytic enzyme produced by Streptomyces sp. (Streptomycetaceae) isolated from Amazonian lichens

Thrombosis is a pathophysiological disorder caused by accumulation of fibrin in the blood. Fibrinolytic proteases with potent thrombolytic activity have been produced by diverse microbial sources. Considering the microbial biodiversity of the Amazon region, this study aimed at the screening, production and biochemical characterization of a fibrinolytic enzyme produced by Streptomyces sp. isolated from Amazonian lichens. The strain Streptomyces DPUA1576 showed the highest fibrinolytic activity, which was 283 mm2. Three variables at two levels were used to assess their effects on the fibrinolytic production. The parameters studied were agitation (0.28 - 1.12 g), temperature (28 - 36 ºC) and pH (6.0 - 8.0); all of them had significant effects on the fibrinolytic production. The maximum fibrinolytic activity (304 mm2) was observed at 1.12 g, 28 ºC, and pH of 8.0. The crude extract of the fermentation broth was used to assess the biochemical properties of the enzyme. Protease and fibrinolytic activities were stable during 6 h, at a pH ranging from 6.8 to 8.4 and 5.8 to 9.2, respectively. Optimum temperature for protease activity ranged between 35 and 55 °C, while the highest fibrinolytic activity was observed at 45 ºC. Proteolytic activity was inhibited by Cu2+ and Co2+ ions, phenylmethylsulfonyl fluoride (PMSF) and pepstatin A, which suggests that the enzyme is a serine protease. Enzymatic extract cleaved fibrinogen at the subunits A-chain, A-chain, and -chain. The results indicated that Streptomyces sp. DPUA 1576 produces enzymes with fibrinolytic and fibrinogenolytic activity, enzymes with an important application in the pharmaceutical industry.The authors grateful acknowledge the financial support of Fundação de Amparo a Pesquisa do Estado de Pernambuco (FACEPE, Pernambuco, Brazil, N. 0158-2.12/11), CNPq/ RENORBIO (National Counsel of Technological and Scientific Development, N.55146/2010-3) and National Council for the Improvement of Higher Education (CAPES, Brazil) for the scholarship. The author thanks editor and reviewers for their review and comments.info:eu-repo/semantics/publishedVersio

DJINN: Implementation and evaluation of implicit social bookmarking paradigm

Social bookmarking is a popular way to share and publish bookmarks. The growth of the social bookmarking community is creating a parallel resource for web searches. In this paper we present an approach called implicit social bookmarking, that creates a bridge between classical web searches initiated in a search engine and search in social bookmarks. Our approach allows a user to implicitly contribute to a social bookmarking system and benefit from other user searches, therefore improving the accuracy of results of web searches. This paper details our approach, presents a prototype implementation of the approach called DJINN, and presents two evaluations of the concept. We conclude with a discussion of our results and directions for future work.Key words: social bookmarking, collaborative filtering, tagging

Pressões De Contato E O Impacto De Conjuntos Motomecanizados Em Latossolo Com Presença E Ausência De Palhada De Cana-de-açúcar

High contact pressures applied to soil result in a greater degree of compaction, in addition to promoting other negative effects. The objective of this study was to quantify contact areas by using different methodologies, and pressures of farm equipment employed in production activity and evaluate structural changes caused in a Red Latosol with the presence and absence of straw cover. The design was completely randomized in a factorial scheme of type 4 (tire on front axle, tire on rear axle, tire on a sugarcane wagon and metallic track of sugar cane Harvester) x 2 (presence and absence of straw). The contact area (CA) of the run was obtained by three procedures: analytical measure of the area of an ellipse (CA1); digital measurement of area of an ellipse (CA2); and measurement of real contact area (RCA), with digital resources. The contact pressure was calculated from the ratio of mass of each machine’s axle and the contact area of the run. The contact area obtained according to the procedure of the ellipse (CA1 and CA2) is overrated when compared to actual area obtained digitally (RCA). The straw reduces the contact pressure in the soil, due to the deep tire treads and consequently, increased contact area. Areas where the traffic of the machines occurred with soil covered with the presence of straw showed reduced soil resistance to penetration, cone index and pre-consolidation pressure, confirming that the increased contact area produced by straw reduced the pressure applied and the compression power dissipated in the soil. © 2016, Federal University of Lavras. All rights reserved.40326527