294 research outputs found

    On the sensitivity reach of LQ production with preferential couplings to third generation fermions at the LHC

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    Leptoquarks (LQs) are hypothetical particles that appear in various extensions of the Standard Model (SM) that can explain observed differences between SM theory predictions and experimental results. The production of these particles has been widely studied at various experiments, most recently at the Large Hadron Collider (LHC), and stringent bounds have been placed on their masses and couplings, assuming the simplest beyond-SM (BSM) hypotheses. However, the limits are significantly weaker for LQ models with family non-universal couplings containing enhanced couplings to third-generation fermions. We present a new study on the production of a LQ at the LHC, with preferential couplings to third-generation fermions, considering proton-proton collisions at s=13\sqrt{s} = 13 TeV\mathrm{TeV} and s=13.6\sqrt{s} = 13.6 TeV\mathrm{TeV}. Such a hypothesis is well motivated theoretically and it can explain the recent anomalies in the precision measurements of B\mathrm{B}-meson decay rates, specifically the RD()R_{D^{(*)}} ratios. Under a simplified model where the LQ masses and couplings are free parameters, we focus on cases where the LQ decays to a τ\tau lepton and a b\mathrm{b} quark, and study how the results are affected by different assumptions about chiral currents and interference effects with other BSM processes with the same final states, such as diagrams with a heavy vector boson, Z\mathrm{Z}^{'}. The analysis is performed using machine learning techniques, resulting in an increased discovery reach at the LHC and allowing us to probe the entirety of the new physics phase space which addresses the B\mathrm{B}-meson anomalies, for LQ masses up to 2.25 TeV\mathrm{TeV}.Comment: 26 pages, 13 figure

    Physicochemical characterization of the yeast cells and lignocellulosic waste used in cell immobilization for ethanol production

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    Ethanol is one of the leading alternative fuels. Efforts have increased the development of technologies for producing ethanol efficiently and economically. The continuous fermentation using yeast cells immobilized in lowcost materials is presented as an excellent alternative. We used four lignocellulosic wastes for the inmobilization process. The materials were characterized physicochemically. The composition was determined by the Van Soest method. Zeta potential was measured to establish the hydrophobic or hydrophilic character of the material surfaces. The contact angles measurements were used to confirm the hydrophobic or hydrophilic character and the free energies interaction was established. Images were obtained by scanning electron microscope, and determination of surface areas and volumes was performed by adsorption and desorption isotherms. It was established that cell surface properties are modified by the immobilization process to which they are subjected. It was evident that cell immobilization depended on the properties of the carrier, as well as cell surface properties. Thus, in order to improve the process of cell immobilization, it is essential to understand the type of carriercell interactions that occur during the immobilization process, making necessary the knowledge of the main surface characteristics of both the media and of cells that can affect the process.This research was in collaboration with the IBB Institute for Biotechnology and Bioengineering Centre of biological Engineering University of Minho, Campus de Gualtar, Braga, Portugal.info:eu-repo/semantics/publishedVersio

    Luxaciones de rodilla: revisión de 11 casos

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    La luxación de rodilla es una entidad poco frecuente. El tratamiento incorrecto de esta lesión conlleva graves consecuencias cuando existen lesiones vasculares que amenazan la supervivencia de la extremidad afecta. Objetivo . analizar el manejo en urgencias, tratamiento definitivo, complicaciones y resultados funcionales en los pacientes diagnosticados de luxación de rodilla. Material y Métodos . Realizamos un estudio retrospectivo de 11 pacientes tratados en nuestro centro con diagnostico de luxación de rodilla entre junio del 2007 y febrero del 2013. Empleamos el Lysholm Score en la evaluación clínica. Resultados . En 8 de los 11 pacientes el tratamiento fue de manera conservadora. En los 3 pacientes intervenidos se optó por una reconstrucción del ligamento cruzado anterior mediante plastia HTH. Los pacientes intervenidos obtuvieron mejor resultado funcional en relación con los no operados (91 puntos frente a 58). Conclusiones . Es fundamental conocer los principios básicos de actuación y tratamiento debido a las complicaciones potenciales que asocia.Knee dislocation is a rare entity. Improper treatment of this injury has serious consequences when vascular lesions that threaten the survival of the affected limb occur. Objective . To analyse the handling emergencies, definitive treatment, complications and functional outcomes in patients diagnosed with knee dislocation. Materials and methods . A retrospective study of 11 patients admitted to our hospital from June 2007 to February 2013 diagnosed with knee dislocation was performed. Clinical evaluation was carried out using the Lysholm score. Results . Eight out of the 11 patients were treated conservatively. Surgical reconstruction of the anterior cruciate ligament plasty with HTH technique was used in three patients. Surgically-treated patients had better functional outcome compared to the non-operated (91 points versus 58). Conclusions . It is essential to know the basic principles of actuation and treatment because of the potential complications associate

    Rotura bilateral de tendón cuadricipital asociado a tratamiento con atorvastatina.

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    La rotura del tendón del cuádriceps es una lesión relativamente poco frecuente. Puede asociarse a enfermedades sistémicas, trasplante renal, tratamientos crónicos u ocurrir de forma espontánea. Presentamos un caso de rotura bilateral de cuádriceps asociada a tratamiento crónico con atorvastatina.Quadriceps tendon rupture is a relatively rare lesion. It has been associated with chronic systemic diseases, renal transplantation or it may occur spontaneously. We present a case of bilateral quadriceps tendon rupture associated with chronic atorvastatin treatment

    Fine root dynamics for forests on contrasting soils in the Colombian Amazon

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    It has been hypothesized that as soil fertility increases, the amount of carbon allocated to below-ground production (fine roots) should decrease. To evaluate this hypothesis, we measured the standing crop fine root mass and the production of fine roots (<2 mm) by two methods: (1) ingrowth cores and, (2) sequential soil coring, during 2.2 years in two lowland forests growing on different soils types in the Colombian Amazon. Differences of soil resources were defined by the type and physical and chemical properties of soil: a forest on clay loam soil (Endostagnic Plinthosol) at the Amacayacu National Natural Park and, the other on white sand (Ortseinc Podzol) at the Zafire Biological Station, located in the Forest Reservation of the Calderón River. We found that the standing crop fine root mass and the production was significantly different between soil depths (0–10 and 10–20 cm) and also between forests. The loamy sand forest allocated more carbon to fine roots than the clay loam forest with the production in loamy sand forest twice (mean±standard error=2.98±0.36 and 3.33±0.69 Mg C ha−1 yr−1, method 1 and 2, respectively) as much as for the more fertile loamy soil forest (1.51±0.14, method 1, and from 1.03±0.31 to 1.36±0.23 Mg C ha−1 yr−1, method 2). Similarly, the average of standing crop fine root mass was higher in the white-sands forest (10.94±0.33 Mg C ha−1) as compared to the forest on the more fertile soil (from 3.04±0.15 to 3.64±0.18 Mg C ha−1). The standing crop fine root mass also showed a temporal pattern related to rainfall, with the production of fine roots decreasing substantially in the dry period of the year 2005. These results suggest that soil resources may play an important role in patterns of carbon allocation to the production of fine roots in these forests as the proportion of carbon allocated to above- and below-ground organs is different between forest types. Thus, a trade-off between above- and below-ground growth seems to exist with our results also suggesting that there are no differences in total net primary productivity between these two forests, but with higher below-ground production and lower above-ground production for the forest on the nutrient poor soi

    Estimation of illicit drug use in the main cities of Colombia by means of urban wastewater analysis

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    Wastewater-based epidemiology (WBE) relies on the principle that traces of compounds, which a population is exposed to or consume, are excreted unchanged or as metabolites in urine and/or feces, and ultimately end up in the sewer network. Measuring target metabolic residues i.e. biomarkers in raw urban wastewater allows identifying the exposure or use of substances of interest in a community. Up to date, the most popular application of WBE is the estimation of illicit drug use and studies have been made mainly across Europe, which has allowed estimating and comparing drug use in many European cities. However, until now a comprehensive study applying WBE on the most frequently consumed illicit drugs has not been performed in South American countries. In this work, we applied this approach to samples from Colombia, selecting two of the most populated cities: Bogotá and Medellin. Several biomarkers were selected to estimate drug use of cocaine, cannabis, amphetamine, methamphetamine, MDMA (ecstasy), heroin and ketamine. Composite samples (24-h) were collected at the corresponding municipal wastewater treatment plants. Sample treatment was performed at location by applying solid-phase extraction (SPE). Before SPE, the samples were spiked with appropriate isotope labeled internal standards. In parallel, samples (spiked with the analytes under study at two concentration levels) were also processed for quality control. Analysis of influent wastewater was made by liquid chromatography-tandem mass spectrometry, with triple quadrupole analyzer. Data shown in this paper reveal a high use of cocaine by the population of the selected Colombian cities, particularly from Medellin, while the use of other illicit drugs were low. The relevance of using quality control samples, particularly in collaborative studies, as those presented in this work, where research groups from different countries participate and where the samples had to be shipped overseas, is highlighted in this paper.The authors of University Jaume I acknowledge the financial support of Generalitat Valenciana (Prometeo II 2014/023) and of the Spanish Ministry of Economy and Competitiveness (Project ref. CTQ2015-65603). Dr. Lubertus Bijlsma acknowledges NPS-Euronet (HOME/2014/JDRUG/AG/DRUG/7086), co-funded by the European Union, for his post-doctoral fellowship. This publication reflects the views only of the authors, and the European Commission cannot be held responsible for any use which may be made of the information contained therein

    Differences in fatty acids composition between <i>Plasmodium</i> infected and uninfected house sparrows along an urbanization gradient

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    Anthropogenic activities such as intensification of agriculture, animal husbandry and expansion of cities can negatively impact wildlife through its influence on the availability of high-quality food resources and pathogen transmission. The house sparrow (Passer domesticus), an urban exploiter, is undergoing a population decline. Nutritional constrains and infectious diseases has been highlighted as potential causes. Fatty acids (FAs) play an important role in modulating certain immune responses needed to combat parasite infections. FAs are highly influenced by dietary availability and have been shown to vary between urban and rural birds. Habitat anthropization also affects avian malaria epidemiology but little attention has been given to the relationship between blood parasite infection, host FAs composition and anthropization. Here, we analysed 165 juvenile birds either infected by Plasmodium or uninfected, captured at 15 localities grouped in triplets containing urban, rural and natural habitats. The total level of FAs was higher in birds from urban than from rural habitats, suggesting a greater availability of fat-rich foods sources. Furthermore, Plasmodium infected birds had higher relative levels of ω-3 polyunsaturated fatty acids (PUFAs) but lower of ω-6 PUFAs than uninfected birds. In concordance, the ω-6/ω-3 ratio was also lower in infected than in uninfected birds, but only from natural habitats, likely driven by the slightly higher ω-3 PUFAs in infected birds from natural habitats. Birds from anthropized environments may metabolize the ω-3 PUFAs to promote anti-inflammatory responses against stressors, which would result in lower ω-3 affecting their response against Plasmodium. Alternatively, lower ω-6 PUFAs may influence birds susceptibility to infection due to a weaker pro-inflammatory response. These descriptive results do not allow us to identify the causality of these associations but highlight the need to further investigate the relevance of FAs for birds to fight infectious diseases in habitats with different degree of urbanization.Peer reviewe

    Prótesis de pirocarbono en fracturas complejas de cabeza de radio.

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    Presentamos los resultados de un estudio observacional retrospectivo sobre 23 casos de fracturas complejas de cabeza de radio tratadas mediante la implantación de una prótesis cabeza radio de pircocarbono (Mo - Pyc). La distribución por sexos fue 10 hombres y 13 mujeres, y la edad media de 54 años. El seguimiento medio fue de 70 meses (48-93 meses). La principal causa fue una fractura de cabeza de radio no reconstruible con inestabilidad asociada de codo. La evaluación clínica se realizó con la Mayo Elbow Performance Score (MEPS). Radiográficamen - te se valoró la congruencia articular, el tamaño de la prótesis, la radiolucencia periprotésica, la osificación heterotópica y la osteoartritis. Al final del seguimiento la media de la escale MEPS fue 82/100, con 84 % resultados de excelentes y buenos. La flexión media fue de 130º, extensión -30º, pronación 76º y supinación 77º. La estabilidad del codo fue buena en todos los casos y no observamos migración proximal del radio. Observamos radiolucencia alrededor del vástago en 5 pacientes, pero sin aparente repercusión clínica. Las complicaciones fueron una paresia del nervio interóseo posterior con recuperación funcional al cabo de 11 semanas, 2 pacientes presentaron "overstuffing" con subluxación posterior asociada que necesitó realizar exéresis de la cabeza y una osificación heterotópica con repercu - sión sobre el balance articular que necesitó 2 cirugías, todos ellos con resultados clínicos aceptables. Los resultados son alentadores.The authors present the results of a retrospective observational study of 23 cases of a complex radial head fractures treated by pyrocarbon radial head prosthesis (MoPyc). This modular radial head prosthesis is compo - sed of a cementless titanium stem and a 15º angulated neck. The gender distribution was 10 men and 13 women, ave - rage age 54 years. The mean follow-up was 70 months (48-93 months). The main etiology was a radial head fracture with elbow instability. Clinical evaluation was performed using the Mayo Elbow Performance Score (MEPS). Was assessed radiographically joint congruity, the size of the prosthesis, periprosthetic radiolucency, heterotopic ossifica - tion and osteoarthritis. At follow-up, the MEPS average was 82/100, with 84% of good and excellent results. Elbow flexion averaged 130º, extension -30º, pronation 76º and supination 77º. Elbow stability was good in all the cases, and no proximal migration of the radius occurred. Asymptomatic bone lucencies were found in five cases around the stem. Complications included paresis of the posterior interosseous nerve with functional recovery after 11 weeks, 2 patients had "overstuffing" associated with posterior subluxation and they need to perform excision of the head and one heterotopic ossification with articular impact on balance that needs two surgeries, all of them with acceptable clinical results. The preliminary results are encouragin
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