Nutritional composition, antioxidant activity and isolation of scopoletin from Senecio nutans: support of ancestral and new uses

Continuing with our study characterising Senecio nutans Sch. Bip., we have isolated and identified a simple coumarin, scopoletin, that could be relevant for the biological properties of the species related with the ancestral medical uses. This is the first report of scopoletin from S. nutans. In addition, the extract was analysed for its antioxidant activity using the ABTS and FRAP method as well as providing the first nutritional analyses of this plant from northern Chile highlands

Estudio experimental de la separación de enargita desde un concentrado de Cu-As mediante flotación

159 p.El procesamiento de concentrados de cobre altamente contaminados en arsénico está representando un considerable impacto ambiental, pues en las etapas principales de fusión y conversión, el arsénico forma productos volátiles, gases fugitivos altamente tóxicos que en algún momento del proceso son emitidos al ambiente. Con el enfoque de reducir las fuentes emisoras de arsénico, el objetivo de la presente memoria consistió en evaluar experimentalmente, las condiciones del proceso de flotación para la separación de un sulfosal de Cu-As, como la enargita, desde un concentrado de cobre industrial proveniente de la División Ministro Hales de la Corporación Nacional del Cobre (Codelco). La separación de minerales arsenicales previos a su procesamiento en los hornos a alta temperatura permitiría controlar el contenido global del elemento en los concentrados y posibilitar tener un mejor manejo de los gases residuales de acuerdo a lo establecido en la norma de emisiones que rige en las fundiciones del cobre (D.S 28). Para ello, la metodología adoptada mediante ensayos experimentales por microflotación, permitió evaluar el efecto del pH, dosificación, tipos de reactivos y distribución de tamaños de partícula, a fin de identificar las condiciones bajo las cuales se promoviera la separación de la enargita y el resto de las menas de Cu. Los resultados mostraron que el pH fue la variable que influenció en mayor medida la recuperación de la enargita, obteniéndose los mejores resultados en las pruebas colectivas realizadas a pH 7,5 en la cual se lograron recuperaciones del 55,3% de enargita y 43,4% de calcopirita. En pruebas con preacondicionamiento del material, el tratamiento de oxidación con gas ozono, promovió una mejoría en la recuperación de ambas menas de cobre, aumentando en un 4% la recuperación de enargita respecto a las pruebas donde no se utilizó este pretratamiento. Se identificó también que, entre los colectores utilizados, el tionocarbamato modificado AERO 5100p, fue el más selectivo para la enargita, mejorando la recuperación de este mineral en la etapa selectiva, sobre el 70%. Es recomendable estudiar en más detalle las variables de flotación que se evaluaron en este estudio con el objetivo de mejorar la eficiencia selectiva en la separación de menas complejas, para ello, resultaría pertinente realizar pruebas de flotación batch para la obtención de parámetros cinéticos, utilizar técnicas de análisis que permita comprender de forma más exacta los fenómenos químicos que intervienen en el sistema o una metodología complementaria, que permita aprovechar los gases arsenicales,caso del As2O3(g),como una fuente de materia prima para fabricar productos comerciales. // ABSTRACT: In this dissertation, an experimental evaluation of the separation of enargite (Cu3AsS4) from a copper concentrate provided by the Ministro Hales Division of Codelco by means of froth flotation tests, is presented. Currently, the copper mining industry operates under harder environmental standards. This includes reducing the solid, liquid and gaseous metallurgical wastes generated in the different stages of the copper production process due to the high environmental impact associated with their releasing into the environment. The separation of mineralogical species before they are processed in the high temperature furnaces to control the arsenic content in the copper concentrates would help that the fugitive gasses emanated during the operation of the Chilean smelters comply with the environmental regulations in terms of their As concentration (D.S 28). The experimental work focused on evaluating the effect of pH, dosage of reagents and particle size distribution on the separation of enargite from a copper concentrate (mainly composed of enargite and chalcopyrite) through microflotation tests in order to identify the operational conditions that promote the separation of enargite from the rest of copper ores. The results allowed identifying that the pH of the flotation medium was the variable with the greatest influence on enargite recovery. The highest enargite and chalcopyrite recovery values were obtained in the tests conducted at pH 7,5, being 55,3% and 43,4%, respectively. The preconditioning tests that consisted of exposing the material to oxidizing media to remove the possible oxidized layers on the surface of the particles, led to lower recovery values of enargite. However, the tests that include ozone insufflation led to higher recoveries of enargite. Also, among the collectors used in this study, it was identified that the modified thionocarbamate (AERO 5100p) was the most selective for enargite, improving the recovery of such mineral. The results obtained in this dissertation represent an excellent source of information that can be used for further experimental studies or even for froth flotation processes in which the isolation of enargite from the rest of copper ores is one of the main purposes

Tratamientos alternativos para el manejo de los mucoceles orales en pacientes pediátricos: revisión narrativa

30 p.Los mucoceles orales son las lesiones benignas más comunes de las glándulas salivales menores, se pueden forman debido a una extravasación del contenido mucoso del conducto de la glándula producto de un trauma, que es lo más frecuente, o producto de una retención de un cuerpo extraño en el conducto, como un sialolito o tapón mucoso. Afecta principalmente a personas jóvenes, su ubicación más frecuente es en el labio inferior y se manifiesta como un nódulo translucido, circunscrito y de apariencia redondeada con superficie lisa. El tratamiento más utilizado para esta lesión, es la extirpación quirúrgica convencional, pero en niños la realización de este tratamiento genera temor y ansiedad, generando incluso la necesidad de usar sedación. Sin embargo, su remoción es necesaria ya que el roce y mordeduras constantes provocan que pocas veces esta lesión remita por si sola. En este estudio nuestro objetivo fue describir al mucocele, los tratamientos convencionales y los tratamientos alternativos, entre los cuales se incluyen la marsupialización, crioterapia, micromarsupialización, inyección intralesional con corticoides, escleroterapia, terapia con láser y aplicación tópica de corticoides, donde finalmente se comparó la efectividad y tolerancia de estos tratamientos en niños. En esta investigación los resultados obtenidos apuntan a que la mayoría de los tratamientos alternativos de los mucoceles son mejor tolerados por los pacientes pediátricos. Además, tanto los tratamientos convencionales como los alternativos son efectivos para el manejo de la lesión. Finalmente, de todos los tratamientos alternativos evaluados el uso de corticoides tópicos, es el que muestra mayores ventajas. // ABSTRACT: Oral mucoceles are the most common benign lesions of the minor salivary glands, they can form due to an extravasation of the mucous content of the gland duct product of a trauma, which is the most frequent, or product of a retention of a foreign body in the duct, like a sialolith or mucous plug. It mainly affects young people, its most frequent location is on the lower lip and it manifests as a translucent, circumscribed nodule with a rounded appearance with a smooth surface. The most widely used treatment for this injury is conventional surgical removal, but in children performing this treatment generates fear and anxiety, even generating the need to use sedation. However, its removal is necessary since the friction and constant bites cause that this injury seldom resolves on its own. In this study, our objective was to describe the mucocele, conventional treatments and alternative treatments, including marsupialization, cryotherapy, micromarsupialization, intralesional injection with corticosteroids, sclerotherapy, laser therapy and topical application of corticosteroids, where it was finally compared the effectiveness and tolerance of these treatments in children. In this research, the results obtained suggest that most of the alternative treatments for mucoceles are tolerated by pediatric patients. In addition, both conventional and alternative treatments are effective in managing the injury. Finally, of all the alternative treatments evaluated, the use of topical corticosteroids is the one that shows the greatest advantages

Sensitivity of Metrics of Phylogenetic Structure to Scale, Source of Data and Species Pool of Hummingbird Assemblages along Elevational Gradients

Patterns of phylogenetic structure of assemblages are increasingly used to gain insight into the ecological and evolutionary processes involved in the assembly of co-occurring species. Metrics of phylogenetic structure can be sensitive to scaling issues and data availability. Here we empirically assess the sensitivity of four metrics of phylogenetic structure of assemblages to changes in (i) the source of data, (ii) the spatial grain at which assemblages are defined, and (iii) the definition of species pools using hummingbird (Trochilidae) assemblages along an elevational gradient in Colombia. We also discuss some of the implications in terms of the potential mechanisms driving these patterns. To explore how source of data influence phylogenetic structure we defined assemblages using three sources of data: field inventories, museum specimens, and range maps. Assemblages were defined at two spatial grains: coarse-grained (elevational bands of 800-m width) and fine-grained (1-km2 plots). We used three different species pools: all species contained in assemblages, all species within half-degree quadrats, and all species either above or below 2000 m elevation. Metrics considering phylogenetic relationships among all species within assemblages showed phylogenetic clustering at high elevations and phylogenetic evenness in the lowlands, whereas those metrics considering only the closest co-occurring relatives showed the opposite trend. This result suggests that using multiple metrics of phylogenetic structure should provide greater insight into the mechanisms shaping assemblage structure. The source and spatial grain of data had important influences on estimates of both richness and phylogenetic structure. Metrics considering the co-occurrence of close relatives were particularly sensitive to changes in the spatial grain. Assemblages based on range maps included more species and showed less phylogenetic structure than assemblages based on museum or field inventories. Coarse-grained assemblages included more distantly related species and thus showed a more even phylogenetic structure than fine-grained assemblages. Our results emphasize the importance of carefully selecting the scale, source of data and metric used in analysis of the phylogenetic structure of assemblages

the interplay of rationality and identity in a mathematical group work

This contribution originates from a joint work aimed at networking theoretical tools and employ them to better understand teaching and learning episodes, with a special focus on mathematical group work. In a socio-cultural perspective, two theoretical lenses are combined: the construct of rational behavior, initially developed by Habermas and adapted in mathematics education, and that of identity. In this paper we propose a general description of our approach and present the main findings emerged after investigations in grade 6 (group work on negative numbers) and grade 4 (arithmetics problem solving). The networked analysis sheds light into mathematical group works: the students' mathematical identities turn into prevailing dimensions of rational behavior and the interplay of dimensions of rationality affects the participation into the group activity. Moreover, the teacher is shown to have a role in students' identifying process, affecting indirectly the students' participation

Measurement of the cross-section of high transverse momentum vector bosons reconstructed as single jets and studies of jet substructure in pp collisions at √s = 7 TeV with the ATLAS detector

This paper presents a measurement of the cross-section for high transverse momentum W and Z bosons produced in pp collisions and decaying to all-hadronic final states. The data used in the analysis were recorded by the ATLAS detector at the CERN Large Hadron Collider at a centre-of-mass energy of √s = 7 TeV;{\rm Te}{\rm V}$and correspond to an integrated luminosity of$4.6\;{\rm f}{{{\rm b}}^{-1}}$. The measurement is performed by reconstructing the boosted W or Z bosons in single jets. The reconstructed jet mass is used to identify the W and Z bosons, and a jet substructure method based on energy cluster information in the jet centre-of-mass frame is used to suppress the large multi-jet background. The cross-section for events with a hadronically decaying W or Z boson, with transverse momentum${{p}_{{\rm T}}}\gt 320\;{\rm Ge}{\rm V}$and pseudorapidity$|\eta |\lt 1.9$, is measured to be${{\sigma }_{W+Z}}=8.5\pm 1.7$ pb and is compared to next-to-leading-order calculations. The selected events are further used to study jet grooming techniques

Search for direct pair production of the top squark in all-hadronic final states in proton-proton collisions at s√=8 TeV with the ATLAS detector

The results of a search for direct pair production of the scalar partner to the top quark using an integrated luminosity of 20.1fb−1 of proton–proton collision data at √s = 8 TeV recorded with the ATLAS detector at the LHC are reported. The top squark is assumed to decay via t˜→tχ˜01 or t˜→ bχ˜±1 →bW(∗)χ˜01 , where χ˜01 (χ˜±1 ) denotes the lightest neutralino (chargino) in supersymmetric models. The search targets a fully-hadronic final state in events with four or more jets and large missing transverse momentum. No significant excess over the Standard Model background prediction is observed, and exclusion limits are reported in terms of the top squark and neutralino masses and as a function of the branching fraction of t˜ → tχ˜01 . For a branching fraction of 100%, top squark masses in the range 270–645 GeV are excluded for χ˜01 masses below 30 GeV. For a branching fraction of 50% to either t˜ → tχ˜01 or t˜ → bχ˜±1 , and assuming the χ˜±1 mass to be twice the χ˜01 mass, top squark masses in the range 250–550 GeV are excluded for χ˜01 masses below 60 GeV

Search for pair-produced long-lived neutral particles decaying to jets in the ATLAS hadronic calorimeter in ppcollisions at √s=8TeV

The ATLAS detector at the Large Hadron Collider at CERN is used to search for the decay of a scalar boson to a pair of long-lived particles, neutral under the Standard Model gauge group, in 20.3fb−1of data collected in proton–proton collisions at √s=8TeV. This search is sensitive to long-lived particles that decay to Standard Model particles producing jets at the outer edge of the ATLAS electromagnetic calorimeter or inside the hadronic calorimeter. No significant excess of events is observed. Limits are reported on the product of the scalar boson production cross section times branching ratio into long-lived neutral particles as a function of the proper lifetime of the particles. Limits are reported for boson masses from 100 GeVto 900 GeV, and a long-lived neutral particle mass from 10 GeVto 150 GeV

Search for the neutral Higgs bosons of the minimal supersymmetric standard model in pp collisions at root s=7 TeV with the ATLAS detector

A search for neutral Higgs bosons of the Minimal Supersymmetric Standard Model (MSSM) is reported. The analysis is based on a sample of proton-proton collisions at a centre-of-mass energy of 7TeV recorded with the ATLAS detector at the Large Hadron Collider. The data were recorded in 2011 and correspond to an integrated luminosity of 4.7 fb-1 to 4.8 fb-1. Higgs boson decays into oppositely-charged muon or τ lepton pairs are considered for final states requiring either the presence or absence of b-jets. No statistically significant excess over the expected background is observed and exclusion limits at the 95% confidence level are derived. The exclusion limits are for the production cross-section of a generic neutral Higgs boson, φ, as a function of the Higgs boson mass and for h/A/H production in the MSSM as a function of the parameters mA and tan β in the mhmax scenario for mA in the range of 90GeV to 500 GeV. Copyright CERN