Browsing by Author "Munoz, C."

Now showing 1 - 12 of 12
  • Thumbnail Image
    Item
  • Thumbnail Image
    Item
    CHLSOC : The Chilean Soil Organic Carbon database, a multi-institutional collaborative effort
    (2020) Pfeiffer, M.; Padarian, J.; Osorio, R.; Bustamante, N.; Federico Olmedo, G.; Guevara, M.; Aburto, F.; Albornoz G., Francisco; Antilén Lizana, Mónica; Araya, E.; Arellano, Eduardo; Barret, M.; Barrera, J.; Boeckx, P.; Briceño, M.; Bunning, S.; Cabrol, L.; Casanova, M.; Cornejo, P.; Corradini, F.; Curaqueo, G.; Doetterl, S.; Duran, P.; Escudey, M.; Espinoza, A.; Francke, S.; Pablo Fuentes, J.; Fuentes, M.; Gajardo, G.; García, R.; Gallaud, A.; Galleguillos, M.; Gomez, A.; Hidalgo, M.; Ivelic Sáez, J.; Mashalaba, L.; Matus, F.; Meza, F.; De La Luz Mora, M.; Mora, J.; Muñoz, C.; Norambuena, P.; Olivera, C.; Ovalle Ortega, Carlos Enrique; Panichini, M.; Munoz, C.; Pérez Quezada, J. F.; Radic, Smiljan; Ramirez, J.; Riveras, N.; Ruiz, G.
  • No Thumbnail Available
    Item
    Fuzzy modelling of pulp density in a mineral grinding plant
    (IEEE, 1994) Cipriano, Aldo; Ramos, M.; Munoz, C.; Guarini Hermann, Marcelo Walter; Guesalaga, A.
    This paper describes an identification algorithm of fuzzy models and its application to the modeling of the pulp density in a mineral grinding plant. The parameters of the fuzzy model are estimated using information obtained from a process simulator. The performance of the fuzzy model is only slightly superior to that of a conventional linear model
  • No Thumbnail Available
    Item
    Highly efficient motion-corrected simultaneous cardiac PET-MR imaging
    (2017) Munoz, C.; Neji, R.; Marsden, P.; Reader, A.J.; Botnar, R.M.; Prieto, C.
  • Thumbnail Image
    Item
    Impact of high wind power penetration on transmission network expansion planning
    (INST ENGINEERING TECHNOLOGY-IET, 2012) Munoz, C.; Sauma, E.; Contreras, J.; Aguado, J.; de La Torre, S.
    Power generation from renewable sources has greatly increased in the last decade. Accordingly, the planning of power system expansions must incorporate the special features of these types of energy sources. Long-term power transmission expansion planning usually does not take these differences among energy sources into account because of the long period considered. However, modelling the special features of renewable sources may influence the optimal transmission plan. In this study, the authors propose a methodology for long-term power transmission expansion planning that incorporates the costs associated with the operation of wind power plants. In particular, the authors model the transmission expansion planning problem as a mixed-integer linear program in which the variability of the wind resource, the impact of wind power operation in the system security and the impact of wind power operation in the reserve market are incorporated. The authors illustrate the methodology using a 34-node version of the main Chilean network.
  • Thumbnail Image
    Item
    Mendelian Randomization Analysis of the Relationship Between Native American Ancestry and Gallbladder Cancer Risk
    (2022) Zollner, L.; Boekstegers, F.; Ponce, C.B.; Scherer, D.; Marcelain, K.; Gárate-Calderón, V.; Waldenberger, M.; Morales, E.; Rojas, A.; Munoz, C.; Müller, B.; Retamales, J.; de Toro, G.; Kortmann, A.V.; Barajas, O.; Rivera, M.T.; Cortés, A.; Loader, D.; Saavedra, J.; Gutiérrez, L.; Ortega, A.; Bertrán, M.E.; Bartolotti, L.; Gabler, F.; Campos, M.; Alvarado, J.; Moisán, F.; Spencer, L.; Nervi Nattero, Bruno; Carvajal, D.; Losada, H.; Almau, M.; Fernández, P.; Olloquequi, J.; Carter, A.R.; Miquel, Juan Francisco; Bustos, B.I.; Guajardo, M.F.; Gonzalez-Jose, R.; Bortolini, M.C.; Acuña-Alonzo, V.; Gallo, C.; Linares, A.R.; Rothhammer, F.; Bermejo, J.L.
    Background A strong association between the proportion of Native American ancestry and the risk of gallbladder cancer (GBC) has been reported in observational studies. Chileans show the highest incidence of GBC worldwide, and the Mapuche are the largest Native American people in Chile. We set out to investigate the causal association between Native American Mapuche ancestry and GBC risk, and the possible mediating effects of gallstone disease and body mass index (BMI) on this association. Methods Markers of Mapuche ancestry were selected based on the informativeness for assignment measure and then used as instrumental variables in two-sample mendelian randomization (MR) analyses and complementary sensitivity analyses. Result We found evidence of a causal effect of Mapuche ancestry on GBC risk (inverse variance-weighted (IVW) risk increase of 0.8% for every 1% increase in Mapuche ancestry proportion, 95% CI 0.4% to 1.2%, p = 6.6×10-5). Mapuche ancestry was also causally linked to gallstone disease (IVW risk increase of 3.6% per 1% increase in Mapuche proportion, 95% CI 3.1% to 4.0%, p = 1.0×10-59), suggesting a mediating effect of gallstones in the relationship between Mapuche ancestry and GBC. In contrast, the proportion of Mapuche ancestry showed a negative causal effect on BMI (IVW estimate -0.006 kg/m2 per 1% increase in Mapuche proportion, 95% CI -0.009 to -0.003, p = 4.4×10-5). Conclusions The results presented here may have significant implications for GBC prevention and are important for future admixture mapping studies. Given that the association between Mapuche ancestry and GBC risk previously noted in observational studies appears to be causal, primary and secondary prevention strategies that take into account the individual proportion of Mapuche ancestry could be particularly efficient.
  • Thumbnail Image
    Item
    Motion corrected water/fat whole-heart coronary MR angiography with 100% respiratory efficiency
    (2019) Munoz, C.; Cruz, G.; Neji, R.; Botnar, René Michael; Prieto Vásquez, Claudia
  • Thumbnail Image
    Item
    Non-contrast enhanced simultaneous 3D whole-heart bright-blood pulmonary veins visualization and black-blood quantification of atrial wall thickness
    (2019) Ginami, G.; Lopez, K.; Mukherjee, R.K.; Neji, R.; Munoz, C.; Roujol, S.; Mountney, P.; Razavi, R.; Botnar, René Michael; Prieto Vásquez, Claudia
  • No Thumbnail Available
    Item
    Predictive control with fuzzy characterization of percentage of solids, particle size and power demand for minerals grinding
    (IEEE, 2001) Orchard, M.; Flores Moltedo, Andrés Ricardo; Munoz, C.; Cipriano, Aldo
    The application of fuzzy predictive control to solve the regulatory problem in mineral grinding plants is considered. The controlled variables are percentage of solids, particle sizes and power demand and the manipulated variables are water and fresh ore flows. The controller uses linear multivariable models and the fuzzy characterization of the controlled variables, to calculate the manipulated variables. Simulation results under typical disturbances show a better performance compared with the conventional predictive control.
  • Thumbnail Image
    Item
    Short-term forecasting of electricity prices in the Colombian electricity market
    (INST ENGINEERING TECHNOLOGY-IET, 2009) Lira, F.; Munoz, C.; Nunez, F.; Cipriano, A.
    The restructuring of the electricity-generating industry from protected monopoly to an open competitive market has presented producers with a problem scheduling generation: finding the optimal bidding strategy to maximise their profits. In order to solve this scheduling problem, a reliable system capable of forecasting electricity prices is needed. This work evaluates the forecasting capabilities of several modelling techniques for the next-day-prices forecasting problem in the Colombian market, measured in USD/MWh. The models include exogenous variables such as reservoir levels and load demand. Results show that a segmentation of the prices into three intervals, based on load demand behaviour, contribute to an important standard deviation reduction. Regarding the models under analysis, Takagi-Sugeno-Kang models and ARMAX models identified by means of a Kalman filter perform the best forecasting, with an error rate below 6%.
  • Thumbnail Image
    Item
    The Gaia-ESO Survey: Detailed abundances in the metal-poor globular cluster NGC 4372
    (EDP SCIENCES S A, 2015) San Roman, I.; Munoz, C.; Geisler, D.; Villanova, S.; Kacharov, N.; Koch, A.; Carraro, G.; Tautvaisiene, G.; Vallenari, A.; Alfaro, E. J.; Bensby, T.; Flaccomio, E.; Francois, P.; Korn, A. J.; Pancino, E.; Recio Blanco, A.; Smiljanic, R.; Bergemann, M.; Costado, M. T.; Damiani, F.; Heiter, U.; Hourihane, A.; Jofre, P.; Lardo, C.; de Laverny, P.; Masseron, T.; Morbidelli, L.; Sbordone, L.; Sousa, S. G.; Worley, C. C.; Zaggia, S.
    We present the abundance analysis for a sample of 7 red giant branch stars in the metal-poor globular cluster NGC 4372 based on UVES spectra acquired as part of the Gaia-ESO Survey. This is the first extensive study of this cluster from high-resolution spectroscopy. We derive abundances of O, Na, Mg, Al, Si, Ca, Sc, Ti, Fe, Cr, Ni, Y, Ba, and La. We find a metallicity of [Fe/H] = -2.19 +/- 0.03 and find no evidence of any metallicity spread. This metallicity makes NGC 4372 one of the most metal-poor Galactic globular clusters. We also find an a-enhancement typical of halo globular clusters at this metallicity. Significant spreads are observed in the abundances of light elements. In particular, we find a Na-O anticorrelation. Abundances of O are relatively high compared with other globular clusters. This could indicate that NGC 4372 was formed in an environment with high O for its metallicity. A Mg-Al spread is also present that spans a range of more than 0.5 dex in Al abundances. Na is correlated with Al and Mg abundances at a lower significance level. This pattern suggests that the Mg-Al burning cycle is active. This behavior can also be seen in giant stars of other massive, metal-poor clusters. A relation between light and heavy s-process elements has been identified.
  • Thumbnail Image
    Item
    The Rare and Challenging Presentation of Gastric Cancer during Pregnancy: A Report of Three Cases
    (2016) Pacheco, S.; Norero Muñoz, Enrique; Canales, C.; Martinez, J. M.; Herrera, M. E.; Munoz, C.; Jarufe Cassis, Nicolás
    Pregnancy-associated gastric cancer is extremely rare. In many cases, it is diagnosed at an advanced stage because the symptoms during pregnancy are generally overlooked. We report three cases of gastric cancer during pregnancy with various outcomes. The first case included a patient with stage IV gastric cancer who received palliative chemotherapy. This patient had a preterm birth and died 7 months after diagnosis. The second case received neoadjuvant chemotherapy during pregnancy and a total gastrectomy was performed after delivery. She then received adjuvant chemoradiotherapy. This patient developed pulmonary metastasis and died of recurrence 41 months after surgery. In the third case, a distal subtotal gastrectomy was performed at week 14 of pregnancy, with no complications. The patient received adjuvant chemoradiotherapy. She is currently without recurrence 14 months after surgery. In patients with pregnancy-associated gastric cancer, treatment decisions are predominantly influenced by clinical stage and gestational age at diagnosis.