475 research outputs found

    An Evolutionary Approach for Learning Opponent's Deadline and Reserve Points in Multi-Issue Negotiation

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    The efficiency of automated multi-issue negotiation depends on the available information about the opponent. In a competitive negotiation environment, agents do not reveal their parameters to their opponents in order to avoid exploitation. Several researchers have argued that an agent's optimal strategy can be determined using the opponent's deadline and reserve points. In this paper, we propose a new learning agent, so-called Evolutionary Learning Agent (ELA), able to estimate its opponent's deadline and reserve points in bilateral multi-issue negotiation based on opponent's counter-offers (without any additional extra information). ELA reduces the learning problem to a system of non-linear equations and uses an evolutionary algorithm based on the elitism aspect to solve it. Experimental study shows that our learning agent outperforms others agents by improving its outcome in term of average and joint utility

    Oxydation d'un acide humique aquatique par le bioxyde de chlore. Incidences sur une post-chloration et sur un traitement au charbon actif

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    Cette Ă©tude de laboratoire a eu pour but d'examiner la rĂ©activitĂ© du bioxyde de chlore sur un acide humique d'origine aquatique en solution aqueuse et en milieu neutre (pH = 7,5) et de prĂ©ciser en particulier l'incidence d'une prĂ©oxydation chimique au CIO2 sur les potentiels de formation de composĂ©s organohalogĂ©nĂ©s (trihalomĂ©thanes, acides dicloroacĂ©tique et trichloroacĂ©tique, chlore organiquement liĂ©) et sur l'adsorbabilitĂ© du carbone organique sur charbon actif.Les rĂ©sultats obtenus montrent que radian du bioxyde de chlore sur racide humique Pinail Ă  l'obscuritĂ©, conduit Ă  des faibles abattements du carbone organique dissous (< 10 %) et de l'absorbance UV Ă  254 nm (de l'ordre de 30 %) et conduit Ă  des productions potentiel es en composĂ©es organohalogĂ©nĂ©s trĂšs nettement infĂ©rieures Ă  celles formĂ©es par chloration. De plus, une prĂ©oxydation chimique au bioxyde de chlore permet de diminuer d'une maniĂšre trĂšs significative la production de composĂ©s organohalogĂ©nĂ©s au cours d'une post-chloration et semble amĂ©liorer l'adsorbabllitĂ© du carbone organique sur charbon actif.L'oxydation de l'acide humique par le bioxyde de chlore s'accompagne, par ailleurs, de la formation de chlorites (0,65 mg/mg de CIO2 consommĂ©) qui peuvent ensuite ĂȘtre oxydĂ©s en chlorates au cours d'une post-chloration ou rĂ©duits en chlorures par un traitement au charbon actif.Enfin, les rĂ©sultats obtenus font apparaĂźtre que le mĂ©canisme d'oxydation de composĂ©s organiques parle bioxyde de chlore en prĂ©sence de la lumiĂšre ainsi que les interactions entre le bioxyde de chore, les chlorites, la matiĂšre organique et le charbon actif mĂ©ritent d'ĂȘtre plus prĂ©cisĂ©ment Ă©tudiĂ©s.Chlorine dioxide has drawn much recent attention as an alternative disinfectant and oxidant for drinking water to replace chlorine because of its powerful disinfecting ability and its limited capacity to produce organohalogenated compounds. However, the use of chlorine dioxide leads to chlorite (ClO2-) and chlorate (ClO3-) as inorganic oxidation by-products which are reported to have toxic effects on humans. The reactions of ClO2 with simple organic compounds (phenols, aliphatic and aromatic amines...) produce polar compounds such as quinone, ketones, aldehydes and carboxylic acids while oxydation by-products of dissolved organic matter of surface waters (in particular humic substances) are largely unknown. Consequently, the aim of this work was to obtain a better understanding of the effects of the use of chlorine dioxide in drinking water treatment To this end, experiments were carried out with dilute aqueous solutions of an isolated aquatic humic acid (Pinail humic acid, PHA) and the objectives of this present study were :- To evaluate the ClO2 demand and to determine the productions of chlorite, chlorate and of organohalogenated compounds such as trihalomethanes (THMs), dichloroacetic and trichloroacetic acids (DCA, TCA) which are the main organohalogenated products formed by chlorination.- To show the effects of chlorine dioxide preoxidation on organic halide formation potentials (postchlorination) and on the removal of dissolved organic carbon (DOC) by activated carbon. In addition, reactions of chlorite with chlorine or with activated carbon were also examined.EXPERIMENTALPniail humic acid was dissolved in phosphate buffered ultra-pure water (pH = 7.5). Oxidation and adsorption experiments were carried out in headspace-free bottles, at 20 ± 1 °C and in the dark. Stock solutions of chlorine dioxide (4-6 g l-1) and of chlorine (6-10 g l-1) were prepared in the laboratory and titrated by iodometry. Residual chlorine dioxide concentration in PHA solutions was determined by spectrophotometric measurement at 360 nm and by two colorimetric methods : the chlorophenol red and the ACVK methods. Concentrations of DOC and of total organic chlorine or halogen (TOCI, TOX) were measured using a DOHRMANN DC 80 carbon analyser and a DOHRMANN DX 20 A TOX analyser equipped with a microcoulometric cell, respectively. THMs, DCA and TCA were determined by a gas chromatograph equipped with a 63 Ni electron capture detector after extraction by pentane for the THMs, and methylation in ether phase for DCA and TCA. Inorganic chlorine species were analysed by HPLC with a UV detector (ClO2-) or by chromatography (Cl-, ClO3-).RESULTS‱ Oxidation of PHA by ClO2The results showed that PHA consumed about 2 mg of ClO2/mg of DOC after a reaction time of 24 hours (fig. 1) and that there is a rapid consumption of ClO2 during the first 30 minutes of the reaction (fig. 2) Oxidation by ClO2 had no effect on DOC concentration (DOC removal : < 10 %) and led to a significant decrease (about 30 %) of the UV-absorbance at 254 or 270 nm (fig. 1 and 2), and to productions of ClO2- (0,65 mg of ClO2-/mg of ClO2 consumed) which were independant of the applied oxidant dose and of the reaction time.Furthermore, after a 72 hour reaction time in the dark, chlorine dioxide ([ClO2]0 = 5 mg l-1, [PHA]0 = 5 mg l-1, DOC = 2,6 mg l-1) produces very small amounts of chloroform (< 5 ”g l-1), DCA (5 ”g l-1) and TCA (5 ”g l-1) and organochlorinated compounds (TOCl : 36 ”g/mg DOC) compared to chlorine oxidation (tableau 1). However, in the presence of sunlight, ClO2 is rapidly photodecomposed (fig. 3) and the photodegradation products of ClO2 allow bromide oxidation (fig. 11) and lead to higher productions of organohalogenated compounds such as THMs (fig. 4).‱ Chlorine dioxide preoxidation followed by chlorinationAs shown in figure 5, chlorine dioxide preoxidation reduces the production of organohalogenated compounds and the chlorine demand during postchlorination. For a preoxidant dose corresponding to the ClO2 demand of PHA, the decrease in the formation potentials of CHCl3, DCA, TCA and TOCl was about 40-50 %. These results confirm the similarity of the action of chlorine dioxide and chlorine on aromatic structures which have high electron density carbons and which constitute probably the most reactive precursors of organohalogenated by-products.As far as chlorite concentration is concerned, the results showed that chlorite formed during the preoxidation step was completely oxidized to chlorate during postchlorination, under the experimental conditions used in this study (chlorine dose : 40 mg l-1; contact time : 24 or 72 hours). Because of the reactions of chlorine eh chlorine and with residual chlorine dioxide, a small increase in the chlorine demand was observed when PHA solutions were heavily preoxidized (fig. 5).‱ Chlorine dioxide preoxidation followed by activated carbon treatmentBatch experiments were carried out with a powdered activated carbon (PAC, granulometry : < 80 ”m) which was obtained by crushing a commercial granular activated carbon (CECA 40,12 x 40 mesh). Once equilibrium was achieved (contact time : 10 days), adsorption isotherms indicated that chlorine dioxide preoxidation increases the absorbability of DOC on activated carbon (fig; 4tableau 2). Furthermore, chlorite in oxidized PHA solutions was reduced by PAC to chloride. The capacity of CECA 40 activated carbon for ClO2- reduction to Cl- was about 170 mg ClO2-/g of PAC (fig. 7). Other experiments showed that chlorite may react with specific surface groups on PAC to produce inorganic carbon (fig. 7) and with PHA only in the presence of PAC as shown the DOC and UV-absorbance curves in figure 8 and the increase of TOX concentration in the liquid phase in figure 9. Thus the observed increase in DOC absorbability on PAC after a chlorine dioxide preoxidation may be attributed to cheminal interactions between PAC, chlorite, residual chlorine dioxide and adsorbed organic matter and requires further study

    Genotype-Phenotype Correlations in Autosomal Dominant Osteogenesis Imperfecta

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    Osteogenesis imperfecta, discussed in Baldridge et al. 2008 is an inherited bone fragility disorder with a wide range of clinical severity that in the majority of cases is caused by mutations in COL1A1 or COL1A2, the genes that encode the two collagen type I alpha chains. Here we describe genotype-phenotype correlations in OI patients who have mutations affecting collagen type I. This paper is based on findings in a large single-centre OI population and a review of the literature

    Interaction primitives for human-robot cooperation tasks

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    To engage in cooperative activities with human partners, robots have to possess basic interactive abilities and skills. However, programming such interactive skills is a challenging task, as each interaction partner can have different timing or an alternative way of executing movements. In this paper, we propose to learn interaction skills by observing how two humans engage in a similar task. To this end, we introduce a new representation called Interaction Primitives. Interaction primitives build on the framework of dynamic motor primitives (DMPs) by maintaining a distribution over the parameters of the DMP. With this distribution, we can learn the inherent correlations of cooperative activities which allow us to infer the behavior of the partner and to participate in the cooperation. We will provide algorithms for synchronizing and adapting the behavior of humans and robots during joint physical activities

    Maladie De Forestier Revelee Par Une Dysphagie A Propos De Deux Cas

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    La maladie de Forestier ou hyperostose ankylosante vertébrale engainante est un désordre musculo-squelettique non inflammatoire responsable d\'une ossification ligamentaire essentiellement du ligament longitudinal antérieur. Elle touche de préférence l\'homme de plus de 50 ans. La dysphagie est un symptÎme rarement observé dans l\'évolution de la maladie de Forestier. Nous rapportons deux cas révélés par une dysphagie isolée. Il s\'agit de deux hommes ùgés de 50 et 56 ans. Le diagnostic était radiologique. La radiographie standard du rachis a objectivé des ostéophytes du rachis cervical. Le transit oesogastroduodénal a montré une compression modérée de l\'oesophage cervical. Le traitement était médical reposant sur les anti inflammatoires non stéroïdiens et les antalgiques. Le traitement chirurgical est indiqué dans les cas de dysphagie sévÚre. Keywords: maladie de Forestier, hyperostose vertébrale, dysphagie. Journal Tunisien d\'ORL et de chirurgie cervico-faciale Vol. 18 2007: pp. 55-5

    Anti-inflammatory drug diclofenac removal by a synthesized MgAl layered double hydroxide

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    Financiado para publicación en acceso aberto: Universidade de Vigo/CISUGLayered double hydroxides (LDHs) containing Mg:Al (molar ratio 3:1) were synthesized by coprecipitation from nitrate salts under alkaline conditions. Their further characterisation by different techniques allowed the determination of their structural, nanotextural and chemical properties. XRD measurements confirmed the high crystallisation with the presence of two metal cations (Mg2+ and Al3+). The use of these materials as eco-friendly adsorbents was analysed to remove diclofenac from wastewater. Under optimal conditions (0.4 g L 1, 30 ppm initial pollutant concentration, pH 8.5), around 65% diclofenac removal was achieved after 60 min of treatment. The pseudo-second kinetic order model and Freundlich isotherm accurately described the experimental data, suggesting chemisorption process on the heterogeneous LDH surface. After diclofenac adsorption, XRD analysis revealed an increase in interlayer spacing followed by contraction of adjacent layers, so that anion exchange between layer was considered to be the main mechanism for diclofenac adsorption. Thermodynamic studies indicate diclofenac adsorption occurs spontaneously, endothermically, and also, with increasing randomness at the solid/solution surface. Batch test revealed limitations in terms of long-term stability of the material. Therefore, a post-synthesis strategy, calcination, was required to increase the degree of resistance. For this purpose, the effect of calcination temperature was examined in the range 200–300 C. Although, the kinetic rate constant decreased slightly after calcination, the improvement of its structural properties allowed to operate under continuous system.Ministerio de Ciencia e Innovación | Ref. PID2020- 113667 GB-I00Ministerio de Ciencia e Innovación | Ref. PDC2021-121394-I00Xunta de Galicia | Ref. ED431C 2021-43Xunta de Galicia | Ref. ED481B 2018/09

    Learning interaction for collaborative tasks with probabilistic movement primitives

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    This paper proposes a probabilistic framework based on movement primitives for robots that work in collaboration with a human coworker. Since the human coworker can execute a variety of unforeseen tasks a requirement of our system is that the robot assistant must be able to adapt and learn new skills on-demand, without the need of an expert programmer. Thus, this paper leverages on the framework of imitation learning and its application to human-robot interaction using the concept of Interaction Primitives (IPs). We introduce the use of Probabilistic Movement Primitives (ProMPs) to devise an interaction method that both recognizes the action of a human and generates the appropriate movement primitive of the robot assistant. We evaluate our method on experiments using a lightweight arm interacting with a human partner and also using motion capture trajectories of two humans assembling a box. The advantages of ProMPs in relation to the original formulation for interaction are exposed and compared

    Novel, Meso-Substituted Cationic Porphyrin Molecule for Photo-Mediated Larval Control of the Dengue Vector Aedes aegypti

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    Dengue is a life-threatening viral disease of growing importance, transmitted by Aedes mosquito vectors. The control of mosquito larvae is crucial to contain or prevent disease outbreaks, and the discovery of new larvicides able to increase the efficacy and the flexibility of the vector control approach is highly desirable. Porphyrins are a class of molecules which generate reactive oxygen species if excited by visible light, thus inducing oxidative cell damage and cell death. In this study we aimed at assessing the potential of this photo-mediated cytotoxic mechanism to kill Aedes (Stegomyia) aegypti mosquito larvae. The selected porphyrin molecule, meso-tri(N-methylpyridyl),meso-mono(N-tetradecylpyridyl)porphine (C14 for simplicity), killed the larvae at doses lower than 1 ”M, and at light intensities 50–100 times lower than those typical of natural sunlight, by damaging their intestinal tissues. The physicochemical properties of C14 make it easily adsorbed into organic material, and we exploited this feature to prepare an ‘insecticidal food’ which efficiently killed the larvae and remained active for at least 14 days after its dispersion in water. This study demonstrated that photo-sensitizing agents are promising tools for the development of new larvicides against mosquito vectors of dengue and other human and animal diseases

    Mother-to-Infant Transmission of Intestinal Bifidobacterial Strains Has an Impact on the Early Development of Vaginally Delivered Infant's Microbiota

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    Objectives: Bifidobacterium species are one of the major components of the infant's intestine microbiota. Colonization with bifidobacteria in early infancy is suggested to be important for health in later life. However, information remains limited regarding the source of these microbes. Here, we investigated whether specific strains of bifidobacteria in the maternal intestinal flora are transmitted to their infant's intestine. Materials and Methods: Fecal samples were collected from healthy 17 mother and infant pairs (Vaginal delivery: 12; Cesarean section delivery: 5). Mother's feces were collected twice before delivery. Infant's feces were collected at 0 (meconium), 3, 7, 30, 90 days after birth. Bifidobacteria isolated from feces were genotyped by multilocus sequencing typing, and the transitions of bifidobacteria counts in infant's feces were analyzed by quantitative real-time PCR. Results: Stains belonging to Bifidobacterium adolescentis, Bifidobacterium bifidum, Bifidobacterium catenulatum, Bifidobacterium longum subsp. longum, and Bifidobacterium pseudocatenulatum, were identified to be monophyletic between mother's and infant's intestine. Eleven out of 12 vaginal delivered infants carried at least one monophyletic strain. The bifidobacterial counts of the species to which the monophyletic strains belong, increased predominantly in the infant's intestine within 3 days after birth. Among infants delivered by C-section, monophyletic strains were not observed. Moreover, the bifidobacterial counts were significantly lower than the vaginal delivered infants until 7 days of age. Conclusions: Among infants born vaginally, several Bifidobacterium strains transmit from the mother and colonize the infant's intestine shortly after birth. Our data suggest that the mother's intestine is an important source for the vaginal delivered infant's intestinal microbiota

    Proposal of an extended t-J Hamiltonian for high-Tc cuprates from ab initio calculations on embedded clusters

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    A series of accurate ab initio calculations on Cu_pO-q finite clusters, properly embedded on the Madelung potential of the infinite lattice, have been performed in order to determine the local effective interactions in the CuO_2 planes of La_{2-x}Sr_xCuO_4 compounds. The values of the first-neighbor interactions, magnetic coupling (J_{NN}=125 meV) and hopping integral (t_{NN}=-555 meV), have been confirmed. Important additional effects are evidenced, concerning essentially the second-neighbor hopping integral t_{NNN}=+110meV, the displacement of a singlet toward an adjacent colinear hole, h_{SD}^{abc}=-80 meV, a non-negligible hole-hole repulsion V_{NN}-V_{NNN}=0.8 eV and a strong anisotropic effect of the presence of an adjacent hole on the values of the first-neighbor interactions. The dependence of J_{NN} and t_{NN} on the position of neighbor hole(s) has been rationalized from the two-band model and checked from a series of additional ab initio calculations. An extended t-J model Hamiltonian has been proposed on the basis of these results. It is argued that the here-proposed three-body effects may play a role in the charge/spin separation observed in these compounds, that is, in the formation and dynamic of stripes.Comment: 24 pages, 4 figures, submitted to Phys. Rev.
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