960 research outputs found
RoboCup Rescue Simulation Machine Learning Workshop
The Rescue Simulation League is the challenge to learn an optimal response for a team of robots that have to mitigate the effects of a disaster. To operate optimal as teams, several aspects have to be solved at once, such as team formation, task allocation and route planning. This is a hard problem, which could be quite overwhelming for newcomer teams. The proposal is to create a workshop, which demonstrates how each of the aspects could be solved with standard machine learning algorithms, as available in MathWorks' Statistics and Machine Learning Toolbox™
Determination of 2,4,6-trichloroanisole by cyclic voltammetry
The electrochemical reduction of 2,4,6-trichloroanisole (TCA), a chlorinated arene with electron-donating substituents, was evaluated by cyclic voltammetry (CV). TCA is a major concern for the winery industry since it is related with “cork taint”, a wine defect. The results obtained showed that CV could be used to detect and quantify TCA in standard solutions. Linear relationships could be set between the current amplitude and TCA concentrations (R>0.990) with detection and quantification limits of 0.08 and 0.26 ppm. Although, these preliminary limits are higher than the human sensory threshold (5 ppt in wine), the simplicity of the methodology confers this study a possible role in the development of more efficient and less expensive process for TCA detection in the industry.This work was partially supported by project PEst-C/EQB/LA0020/2011, financed by FEDER through COMPETE - Programa Operacional Factores de Competitividade and by FCT - Fundacao para a Ciencia e a Tecnologia
Ferromagnetism without flat bands in thin armchair nanoribbons
Describing by a Hubbard type of model a thin armchair graphene ribbon in the
armchair hexagon chain limit, one shows in exact terms, that even if the system
does not have flat bands at all, at low concentration a mesoscopic sample can
have ferromagnetic ground state, being metallic in the same time. The mechanism
is connected to a common effect of correlations and confinement.Comment: 37 pages, 12 figures, in press at Eur. Phys. Jour.
Pseudogap Formation in the Symmetric Anderson Lattice Model
We present self-consistent calculations for the self-energy and magnetic
susceptibility of the 2D and 3D symmetric Anderson lattice Hamiltonian, in the
fluctuation exchange approximation. At high temperatures, strong f-electron
scattering leads to broad quasiparticle spectral functions, a reduced
quasiparticle band gap, and a metallic density of states. As the temperature is
lowered, the spectral functions narrow and a pseudogap forms at the
characteristic temperature at which the width of the quasiparticle
spectral function at the gap edge is comparable to the renormalized activation
energy. For , the pseudogap is approximately equal to the
hybridization gap in the bare band structure. The opening of the pseudogap is
clearly apparent in both the spin susceptibility and the compressibility.Comment: RevTeX - 14 pages and 7 figures (available on request),
NRL-JA-6690-94-002
Bioactive components and antioxidant and antibacterial activities of different varieties of honey: a screening prior to clinical application
This study assessed 16 different honey samples in order to select the best one for therapeutic purposes. First, a study of honey's main bioactive compounds was carried out. Then phenolic profiles were determined and specific compounds quantified using a HPLC system coupled to a mass spectrometer. Then, antioxidant activity, by three in vitro methods, and antibacterial activity against reference strains and clinical isolates were evaluated. Great variability among samples was observed regarding ascorbic acid (between 0.34 ± 0.00 and 75.8 ± 0.41 mg/100 g honey; p < 0.001), total phenolic compounds (between 23.1 ± 0.83 and 158 ± 5.37 mg/100 g honey; p < 0.001), and total flavonoid contents (between 1.65 ± 0.11 and 5.93 ± 0.21 mg/100 g honey; p < 0.001). Forty-nine different phenolic compounds were detected, but only 46 of them were quantified by HPLC. The concentration of phenolic compounds and the phenolic profiles varied widely among samples (between 1.06 ± 0.04 and 18.6 ± 0.73 mg/100 g honey; p < 0.001). Antioxidant activity also varied significantly among the samples. All honey varieties exhibited antibacterial activity against both reference and clinical strains (effective concentrations ranged between 0.05 and 0.40 g/mL depending on the honey sample and bacteria tested). Overall, samples with better combinations of bioactive properties were avocado and chestnut honeys.This work was supported by the ConsejeriaFundinǵ de Sanidad of Junta de Castilla y Leoń (Spain); under grant GRS 551/A/10. P.C.-F. was funded by the Consejeriá de Educacioń of Junta de Castilla y Leoń and European Social Fund. Notes The authors declare no competing financial interest.info:eu-repo/semantics/publishedVersio
Mieles españolas con marca de calidad: un enfoque multivariado de parámetros fisicoquímicos, calidad microbiológica y origen floral
This study consisted of a palynological, microbiological, and physicochemical characterization of fifteen samples of Spanish honey sold under quality brands with different botanical and geographical origins from two consecutive harvest years (2010 and 2011). Eight of the fifteen honey samples were classified as monofloral honey from botanical origins Persea americana, Castanea sativa, Rosmarinus officinalis, Eucalyptus sp., and Thymus sp. With regard to microbiological analyses, mold, and yeast counting, Staphylococcus aureus, Salmonella, sulfite-reducing clostridia, and Escherichia coli were not detected in any of the samples. Aerobic mesophilic microorganisms were detected only in some samples and the counts in these cases were low. Despite the great variability between samples, the results obtained in the physicochemical analysis were consistent with the limits set by the Council Directive 2001/100. Honey samples showed high variability between two consecutive harvests, since, even if they had similar geographical origins they showed different nectar floral origins. Mieles españolas con marca de calidad: un enfoque multivariado de parámetros fisicoquímicos, calidad microbiológica y origen floral Este estudio consistió en la caracterización botánica, microbiológica y fisicoquímica de quince muestras de miel españolas acogidas a marcas de calidad diferenciada de diferentes orígenes botánicos y geográficos y procedentes de dos cosechas consecutivas (años 2010 y 2011). Ocho de las quince muestras de miel estudiadas fueron clasificadas como mieles monoflorales de Persea americana, Castanea sativa, Rosmarinus officinalis, Eucalyptus sp. y Thymus sp. En relación a los análisis microbiológicos los recuentos de mohos y levaduras, Staphylococcus aureus, Salmonella, clostridios sulfito reductores y Escherichia coli no fueron detectados en ninguna de las muestras. Se detectaron microorganismos aerobios mesófilos solo en algunas muestras y en este caso los recuentos fueron bajos. Aunque se detectaron coliformes, estos podrían estar asociados a un origen ambiental. A pesar de la gran variabilidad entre las muestras, los resultados obtenidos en el análisis fisicoquímico se encontraron dentro de los límites establecidos por la Directiva del Consejo 2001/100. Las muestras de miel mostraron una gran variabilidad entre cosechas porque aunque tuvieron un mismo origen geográfico, hubo diferencias en su origen floral.Este estudio consistió en la caracterización botánica, microbiológica y fisicoquímica de quince muestras de miel españolas acogidas a marcas de calidad diferenciada de diferentes orígenes botánicos y geográficos y procedentes de dos
cosechas consecutivas (años 2010 y 2011). Ocho de las quince muestras de miel estudiadas fueron clasificadas como mieles monoflorales de Persea americana, Castanea sativa, Rosmarinus officinalis, Eucalyptus sp. y Thymus sp. En
relación a los análisis microbiológicos los recuentos de mohos y levaduras, Staphylococcus aureus, Salmonella, clostridios
sulfito reductores y Escherichia coli no fueron detectados en ninguna de las muestras. Se detectaron microorganismos
aerobios mesófilos solo en algunas muestras y en este caso los recuentos fueron bajos. Aunque se detectaron
coliformes, estos podrían estar asociados a un origen ambiental. A pesar de la gran variabilidad entre las muestras, los
resultados obtenidos en el análisis fisicoquímico se encontraron dentro de los l ımites establecidos por la Directiva del
Consejo 2001/100. Las muestras de miel mostraron una gran variabilidad entre cosechas porque aunque tuvieron un
mismo origen geográfico, hubo diferencias en su origen floral.This work was supported by the Consejería de Sanidad. Junta
de Castilla y León [GRS 551/A/10]; Patricia Combarros-
Fuertes PhD Research was funded by Consejería de
Educación. Junta de Castilla y León and Fondo Social Europeo.info:eu-repo/semantics/publishedVersio
Reguladores vegetais no enraizamento e desenvolvimento de gemas de cana-de-açúcar tratadas termicamente
Este trabalho teve por finalidade estudar o efeito de reguladores vegetais sobre a emergência e desenvolvimento inicial de gemas de cana-de-açúcar 'IAC 52-150', submetidas ao tratamento térmico por via úmida. Para tanto, as gemas foram tratadas durante uma hora em soluções de ácido indolilacético (IAA) e ácido naftalenacêtico (NAA), nas concentrações de 10, 25, 50 e 100 ppm, em ácido indolbutírico (IBA) nas concentrações de 10 e 25 ppm e em água pura (testemunha). Imediatamente após o tratamento, as gemas foram plantadas em germinadores de areia. IBA 10 ppm tendeu a favorecer a emergência e o enraizamento das gemas. IAA não afetou a emergência, enraizamento e peso da parte aérea da cana-de-açúcar. Aplicação de NAA 100 ppm reduziu a porcentagem de emergência e o peso da parte aérea do cultivar IAC 52-150.The effect of growth regulators on the germination and initial development of sugar cane shoots submitted to high temperature treatment by the moist method was studied. The shoots were treated during 1 hour with indoleacetic´acid (IAA) and naphthaleneacetic acid (NAA) at the concentrations of 10, 25, 50 and 100 ppm, with indolebutyric acid (IBA) at the concentrations of 10 and 25 ppm and with pure water (control). Immediately after the treatment, the shoots were planted in sand germinators. The results showed that treatment with IBA 10 ppm promote a tendency to induce germination and roots development. The root system development was not affected by other treatments, but the development of the aerial portion was adversely affected by NAA 100 ppm. The results showed that, after 60 days, the number of emerged shoots was significantly lower than that of the control in the plots treated with 100 ppm of NAA
Twist Deformations of the Supersymmetric Quantum Mechanics
The N-extended Supersymmetric Quantum Mechanics is deformed via an abelian
twist which preserves the super-Hopf algebra structure of its Universal
Enveloping Superalgebra. Two constructions are possible. For even N one can
identify the 1D N-extended superalgebra with the fermionic Heisenberg algebra.
Alternatively, supersymmetry generators can be realized as operators belonging
to the Universal Enveloping Superalgebra of one bosonic and several fermionic
oscillators. The deformed system is described in terms of twisted operators
satisfying twist-deformed (anti)commutators. The main differences between an
abelian twist defined in terms of fermionic operators and an abelian twist
defined in terms of bosonic operators are discussed.Comment: 18 pages; two references adde
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