81,265 research outputs found
Evidence for the decay B0→J/ψω and measurement of the relative branching fractions of meson decays to J/ψη and J/ψη′
No full textFirst evidence of the B 0 → J / ψ ω decay is found and the B s 0 → J / ψ η and B s 0 → J / ψ η ′ decays are studied using a dataset corresponding to an integrated luminosity of 1.0 fb -1 collected by the LHCb experiment in proton-proton collisions at a centre-of-mass energy of sqrt(s) = 7 TeV. The branching fractions of these decays are measured relative to that of the B 0 → J / ψ ρ 0 decay:frac(B (B 0 → J / ψ ω), B (B 0 → J / ψ ρ 0)) = 0.89 ± 0.19 (stat) - 0.13 + 0.07 (syst),frac(B (B s 0 → J / ψ η), B (B 0 → J / ψ ρ 0)) = 14.0 ± 1.2 (stat) - 1.5 + 1.1 (syst) - 1.0 + 1.1 (frac(f d, f s)),frac(B (B s 0 → J / ψ η ′), B (B 0 → J / ψ ρ 0)) = 12.7 ± 1.1 (stat) - 1.3 + 0.5 (syst) - 0.9 + 1.0 (frac(f d, f s)), where the last uncertainty is due to the knowledge of f d / f s, the ratio of b-quark hadronization factors that accounts for the different production rate of B 0 and B s 0 mesons. The ratio of the branching fractions of B s 0 → J / ψ η ′ and B s 0 → J / ψ η decays is measured to befrac(B (B s 0 → J / ψ η ′), B (B s 0 → J / ψ η)) = 0.90 ± 0.09 (stat) - 0.02 + 0.06 (syst)
Optimización de parámetros para la extracción de elementos desde minerales en medios ácido
No full text[SPA] Esta tesis doctoral se presenta bajo la modalidad de compendio de publicaciones. Actualmente, la gran minería del cobre chilena se encuentra frente a nuevos problemas y desafíos a superar. El principal problema, es de carácter medio ambiental, debido a que la mayor parte de la producción es por procesos de flotación, lo que implica aumentar la generación de relaves, ocasionando drenajes ácidos que generan la movilidad de elementos pesados al medio ambiente. Otro desafío importante, es diversificar las extracciones de otros elementos (como ocurre actualmente con el molibdeno) para impulsar la exportación de productos básicos y aumentar el empleo. Además, se deben tratar recursos que hoy en día no se están aprovechando a escala industrial, un ejemplo son los minerales de cobre negro, estos recursos generalmente no se incorporan en las pilas de lixiviación. Estos minerales exóticos tienen cantidades considerables de Mn (aproximadamente 29%), lo que representa un atractivo comercial. Para abordar este desafío, se realizaron investigaciones a nivel laboratorio, de extracción de cobre y manganeso desde cobres negros mediante procesos de lixiviación. Se evaluaron diferentes aditivos y concentraciones de estos mediante la aplicación de modelos estadísticos de regresión cuadrática, evaluando efectos lineales, interacciones y curvaturas. Además, se diseñaron y probaron con éxito nuevos procesos de extracción. Finalmente, se pudo demostrar que para la disolución de Mn ya sea desde nódulos marinos o cobres negros, se obtienen resultados positivos al adicionar Fe en el sistema, siendo un parámetro óptimo de trabajo una razón de MnO2/Fe de 1/2, logrando extracciones sobre el 70% en tiempos de 20 min. Para la disolución de Cu desde sulfuros secundarios, se puede concluir que los mejores resultados se obtienen al trabajar a elevadas concentraciones de cloruro, siendo poco relevante la concentración de H2SO4. Por otra parte, para la disolución de calcopirita, trabajar en un medio clorurado incorporando altas concentraciones de MnO2 (razones de MnO2/CuFeS2 de 5/1) favorece el mantener un alto valor de potencial en el sistema, superando la pasivación de este mineral.[ENG] This doctoral dissertation has been presented in the form of thesis by publication. Currently, the great copper mining is facing new problems and challenges to overcome. The main problem is environmental, because most of the production is due to flotation processes, which implies increasing the generation of tailings, causing acid drains that generate the mobility of heavy elements to the environment. Another important challenge is to diversify the extractions of other elements (as is currently the case with molybdenum) to boost the export of basic products and increase employment. In addition, resources that are not currently being used on an industrial scale should be treated, an example is black copper ores, these resources are generally not incorporated into the extraction circuits or are not treated, whether in stocks, platforms leaching or waste. These exotic minerals have considerable amounts of Mn (approximately 29%), which represents a commercial appeal. To address this challenge, research was carried out at the laboratory level, for the extraction of copper and manganese from minerals through leaching processes. Evaluating different additives and concentrations thereof, applying the use of statistical models of quadratic regression, evaluating linear effects, interactions and curvatures. And in other cases, creating new extraction processes. Finally, it was discovered that for the dissolution of Mn either from marine nodules or black copper, very positive results are obtained by adding Fe in the system, an optimal working parameter being a ratio of MnO2/Fe of 1/2, achieving extractions above 70% in times of 20 min. For the dissolution of Cu from secondary sulphides, it was found that the best results are obtained when working at high concentrations of chloride, the concentration of H2SO4 being insignificant. On the other hand, for the dissolution of chalcopyrite, working in a chlorinated medium incorporating high concentrations of MnO2 (ratios of MnO2 / CuFeS2 of 5/1) favors maintaining a high potential value in the system, overcoming the passivation of this mineral.Escuela Internacional de Doctorado de la Universidad Politécnica de CartagenaPrograma de Doctorado en Tecnología y Modelización en Ingeniería Civil, Minera y AmbientalScientific Equipment Unit- MAINI of the Universidad Católica del Norte (Chile)Los artículos que componen la tesis son los siguientes: Publicación 1: N. Toro*, M. Saldaña, E. Gálvez, M. Cánovas, E. Trigueros, J. Castillo and P. Hernández. “Optimization of Parameters for the Dissolution of Mn from Manganese Nodules with the Use of Tailings in an Acid Medium” Q2 ISI WoS. Minerals, 2019; https://doi.org/10.3390/min9070387. Publicación 2: N. Toro*, W. Briceño, K. Pérez, M. Cánovas, E. Trigueros, R. Sepúlveda and P. Hernández. “Leaching of Pure Chalcocite in a Chloride Media Using Sea Water and Waste Water” Q1 ISI WoS. Metals, 2019; https://doi.org/10.3390/met9070780. - Publicación 3: M. Saldaña, N. Toro*, J. Castillo, P. Hernández, E. Trigueros, and A. Navarra. “Development of an Analytical Model for the Extraction of Manganese from Marine Nodules” Q1 ISI WoS. Metals, 2019 https://doi.org/10.3390/met9080903. - Publicación 4: N. Toro*, K. Pérez, M. Saldaña, R. I. Jeldres, M. Jeldres and M. Cánovas. “Dissolution of pure chalcopyrite with manganese nodules and waste water” Q1 ISI WoS. Journal of Materials Research and Technology, 2019 https://doi.org/10.1016/j.jmrt.2019.11.020. - Publicación 5 (En Revisión): N. Toro*, W. Briceño, A. Navarra, K. Pérez, M. Cánovas and E. Trigueros. “Statistical and kinetic study for leaching of covellite in a chloride media” Q1 ISI WoS. Journal of Materials Research and Technology.Universidad Politécnica de Cartagen
Letter from Carl Hayden to M. J. Riordan
No full textLetter from Carl Hayden to M. J. Riordan expressing his support for Coconino County in turning over the Bright Angel Trail to the federal government
Frequency-based organization of speech sequences in a nonhuman animal
No full textA recurrent question regarding language acquisition is the extent to which the mechanisms human infants use to discover patterns over the linguistic signal are highly specialized and uniquely human, or are the result of more general mechanisms present in other species. Research with very young infants suggests that they are able to use the relative frequency of elements in a linguistic sequence to infer word order. Here we ask if this ability could emerge from grouping biases present in nonhuman mammals. We show that animals discover differences in the frequency of elements in a sequence and can learn the relative order of frequent and infrequent elements. Nevertheless, in animals, relative frequency does not appear to be overridden by other cues that have been shown to be important to human infants, such as prosody. Our results demonstrate that the basic mechanism that allows listeners to extract ordering relations based on frequency is shared across species.The present research has received funding from the European Research Council under the European Union’s Seventh Framework Programme (FP7/2007–2013)/ERC grant agreement no. 269502 (PASCAL) to MN; ERC grant agreement no. 312519 and PSI2013-44992-P to JMT, and from the Agence Nationale de la Recherche (Programme JCJC 21373), the Emergence(s) program of the City of Paris as well as from the French Investissements d’Avenir – Labex EFL Program (ANR-10-LABX-0083) to JG
Choice Experiments in Enviromental Impact Assessment: The Toro 3 Hydroelectric Project and the Recreo Verde Tourist Center in Costa Rica
No full textChoice experiments, a stated preference valuation method, are proposed as a tool to assign monetary values to environmental externalities during the ex-ante stages of environmental impact assessment. This case study looks at the impacts of the Costa Rican Institute of Electricity’s Toro 3 hydroelectric project and its affects on the Recreo Verde tourism center in San Carlos, Costa Rica. Compared to other valuation methods (e.g., travel cost and contingent valuation), choice experiments can create hypothetical but realistic scenarios for consumers and generate restoration alternatives for the affected good. Although they have limitations that must be taken into account in environmental impact assessments, incorporating economic parameters—especially resource constraints and tradeoffs—can substantially enrich the assessment process.stated-preference, economic valuation, choice experiments, hydropower, tourism, Costa Rica
Letter from M. J. Riordan, Arizona Lumber and Timber Company, to Carl Hayden
No full textLetter from M. J. Riordan to Carl Hayden expressing his opposition to the federal government's takeover of Bright Angel Trail
Atyidae and Palaemonidae (Crustacea: Decapoda: Caridea) of Bocas del Toro, Panama.
No full textThe present contribution is a preliminary report on the freshwater caridean fauna of Bocas del Toro province, northeastern Panama, based on field collections carried out during a Shrimp Taxonomy Workshop at the STRI station in Bocas del Toro in August 2008. A total of eight species from two families, Atyidae and Palaemonidae, were collected at 17 different collection sites in the rivers, streams and ponds on several islands of the Bocas del Toro archipelago and the adjacent mainland. The species reported herein are Atya scabra (Leach, 1815), Jonga serrei (Bouvier, 1909), Micratya poeyi (Guérin-Méneville, 1855), Potimirim glabra (Kingsley, 1878), P. potimirim (Müller, 1881) (Atyidae), Palaemon pandaliformis (Stimpson, 1871), Macrobrachium acanthurus (Wiegmann, 1836) and M. crenulatum Holthuis, 1950 (Palaemonidae). The record of J. serrei is the first for Panama, and M. poeyi a P. glabra the first for Bocas del Toro province
Defying the law, negotiating change The Futanke’s opposition to the national ban on FGM in Senegal
No full textThis thesis is concerned with the politics of the preservation and ‘abandonment’ of female circumcision in Fouta Toro, Senegal. The focal point of analysis is the overt opposition to the law criminalising female genital cutting in 1999, and development projects raising awareness about excision in human rights and reproductive health education programmes. As an ethnography of the politics around bodily practices in the light of governmental and non-governmental intervention, the thesis looks at how different interest groups justify their position towards excision. This is a timely enquiry, given the Senegalese government’s ‘acceleration programme of the complete abandonment of excision by 2015’ and some Futanke leaders’ non-compliance with, and opposition to this intervention.
After providing details about ‘the ban’ on ‘female genital mutilation’ in Senegal and a critical reflection on the events that are seen to have led to the call for this ban, I carefully disentangle what ‘the opposition to the law’ is and who disagrees with ‘the abandonment’ of the practice in Fouta Toro. The central part of the thesis is guided by an analysis of how excision is embedded in constructions of personhood, sociality and ethnic identity, and how the body is imagined and located in this process. I show how conceptions of ethnic purity and pride are formulated in terms of fear about a ‘loss of culture’ and ‘foreign invasion’ which nourishes discourses of opposition to the law and non-governmental intervention. Others use ‘human rights’ associated with non-governmental organisations and the state as a vehicle to express their views against excision and those who oppose its criminalisation. I examine how idioms like ‘the state’, ‘human rights’ and ‘Futanke way of life’ feature in discourses around the ban of excision in Fouta Toro, and how respectability and honour are maintained through competing representations of the female body as a site of morality. Some claim the female body – a reproducer of cultural identities – with reference to duties through kin obligations, others with reference to ‘human rights’ and ‘the state’.
Based on 15 months’ ethnographic fieldwork in Fouta Toro and nine years working in and researching the impact of development in Senegal, this dissertation contributes to scholarship on Fouta Toro and indicates how governmental and non-governmental intervention stirs up the caste-related power structures of a society led by the Tooroɓɓe since the Islamic revolution in the 18th century. It shows how the female body is located as a site of morality, key to the reproduction of cultural identities
The Selfish-Brain hypothesis as possible cause of arterial hypertension: a modeling study
No full textWe use a global closed loop multiscale mathematical model of the human circulation to study a novel vascular hypothesis about the onset of essential hypertension. We extend the Muller-Toro model accounting for a precise cerebellum and brainstem vascular network, an autoregulation mechanism of brain hemodynamics, a detailed cerebrospinal fluid dynamics. We present preliminary computational
results about the impact of some vascular cerebral anatomical malformations on cerebral perfusion and blood flow before the onset of arterial hypertension
Somatostatin interferes with thyrotropin-induced G1-S transition mediated by cAMP-dependent protein kinase and phosphatidylinositol 3-kinase. Involvement of RhoA and cyclin E x cyclin-dependent kinase 2 complexes
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