QSAR study for carcinogenicity in a large set of organic compounds

In our continuing efforts to find out acceptable Absorption, Distribution, Metabolization, Elimination and Toxicity (ADMET) properties of organic compounds, we establish linear QSAR models for the carcinogenic potential prediction of 1464 compounds taken from the "Galvez data set", that include many marketed drugs. More than a thousand of geometry-independent molecular descriptors are simultaneously analyzed, obtained with the softwares E-Dragon and Recon. The variable subset selection method employed is the Replacement Method, and also the improved version Enhanced Replacement Method. The established models are properly validated through an external test set of compounds, and by means of the Leave-Group-Out Cross Validation method. In addition, we apply the Y-Randomization strategy and analyze the Applicability Domain of the developed model. Finally, we compare the results obtained in present study with the previous ones from the literature. The novelty of present work relies on the development of an alternative predictive structure-carcinogenicity relationship in a large heterogeneous set of organic compounds, by only using a reduced number of geometry independent molecular descriptors.Fil: Duchowicz, Pablo Román. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; ArgentinaFil: Comelli, Nieves Carolina. Universidad Nacional de Catamarca. Facultad de Ciencias Agrarias; ArgentinaFil: Ortiz, Erlinda del Valle. Universidad Nacional de Catamarca. Facultad de Tecnología y Ciencias Aplicadas; ArgentinaFil: Castro, Eduardo Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; Argentin

El comportamiento del gasto público en España durante la Segunda República, 1931-1935

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K-12 Service Learning in Argentina

K-12 Service Learning in Argentin

Exploring the Crystal Structure Space of CoFe2P by Using Adaptive Genetic Algorithm Methods

Advances in theoretical and computational condensed matter physics have opened the possibility to predict and design magnetic materials for specific technological applications. In this paper, we use the adaptive-genetic algorithm technique for exploring the low-energy crystal structure configurations of Co0.25Fe0.5P0.25, aiming to find new low-energy non-cubic phases with high saturation magnetization that might be interesting for high-performance permanent magnet development.This work was supported in part by the NOVAMAG project under Grant 686056, in part by the EU Horizon 2020 Framework Program for Research and Innovation (2014–2020), and in part by the Spanish Supercomputing Network and CESVIMA for providing computational resources under Grant QCM-2016-2-0034

Self-consistent description of spin-phonon dynamics in ferromagnets

Several recently reported exciting phenomena such as spin caloritronics or ultrafast laser-induced spin dynamics involve the action of temperature on spin dynamics. However, the inverse effect of magnetization dynamics on temperature change is very frequently ignored. Based on the density matrix approach, in this work we derive a self-consistent model for describing the magnetization and phonon temperature dynamics in ferromagnets in the framework of the quantum Landau-Lifshitz-Bloch equation. We explore potential applicability of our approach for two cases, inspired by magnetocaloric effect and magnetic fluid hyperthermia. In the first case, the spin-phonon dynamics is governed by the longitudinal relaxation in bulk systems close to the Curie temperature; while in the second case it is described by the transverse relaxation during the hysteresis cycle of individual nanoparticles well below the Curie temperature

A high-throughput exploration of magnetic materials by using structure predicting methods

We study the capability of a structure predicting method based on genetic/evolutionary algorithm for a high-throughput exploration of magnetic materials. We use the USPEX and VASP codes to predict stable and generate low-energy meta-stable structures for a set of representative magnetic structures comprising intermetallic alloys, oxides, interstitial compounds, and systems containing rare-earths elements, and for both types of ferromagnetic and antiferromagnetic ordering. We have modified the interface between USPEX and VASP codes to improve the performance of structural optimization as well as to perform calculations in a high-throughput manner. We show that exploring the structure phase space with a structure predicting technique reveals large sets of low-energy metastable structures, which not only improve currently exiting databases, but also may provide understanding and solutions to stabilize and synthesize magnetic materials suitable for permanent magnet applications.EU H2020 Program Project NOVAMAG: Novel, critical materials free, high anisotropy phases for permanent magnets, by design (Project ID: 686056)

An adaptive genetic algorithm approach for predicting magnet-ic structure suitable for high-performance permanent magnet development

Trabajo presentado en: International Conference on Magnetics (INTERMAG), 2017Summary form only given. In this work, we present a general overview, analysis and software implementation of a particular AGA, which has been proposed for discovering new RE-free magnetic crystal phases in the context of the EU-H2020 NOVAMAG project. The workflow diagram related to the Modelling Data Elements (MODA) of the magnetic crystal structure calculation based on AGA was shown. In particular, we make use of an AGA, implemented through USPEX and VASP codes, to predict new magnetic crystal phases, where those structures with better magnetic properties for a permanent magnet are selected and analyzed in more detail. Such a methodology has been preliminary compared to well-known experimentally reported properties compounds, showing an excellent agreement. In addition, we show recent results predicted by AGA in CoFe 2n X (n=1,2,3,4,5; where X=C, P, Hf, Zr, ...), where we found compounds with many metastable structures which fulfill the initial requirements (negative enthalpy of formation ΔHF1T and non-cubic lattice system) for permanent magnet development.NOVAMAG project, under Grant Agreement No. 686056, EU Horizon 2020 Framework Programme for Research and Innovation (2014-2020). Authors also acknowledge the Spanish Supercomputing Network (RES) and CESVIMA for providing supercomputational resources under Ref: QCM-2016-2-0034

Análisis del comportamiento del mercado bursátil mediante modelos ARIMA

RESUMEN Este trabajo tiene el objetivo de analizar el comportamiento del precio de los activos bursátiles para examinar sus posibilidades de predicción mediante modelos matemáticos. En él, a través de modelos ARIMA aplicados por medio del software R, se va a tratar de comprobar o desmentir la hipótesis del mercado eficiente y el paseo aleatorio, y a la par que se va a evaluar la utilidad de ARIMA para la predicción. Para el estudio se analizarán dos índices: el estadounidense S&P 500 y el español IBEX 35. Palabras Clave: “Predicción”, “R”, “ARIMA”, “Series Temporales”, “Mercado Bursátil”, “Tendencia”, “Inversión”, “Aleatoriedad”.ABSTRACT The main purpose of this work is to analyze the behaviour of stock assets prices, to check their posibilities of being predicted by mathematical models. In it, usig ARIMA models in the R software, is going to be tried to prove or to reject the hypotesis of the market efficiency and the random walk, and, meanwhile, is going to be examined the capability of prediction of ARIMA. In the study two indexes are going to be analyzed: The american S&P 500 and the spanish IBEX 35 Key Words: “Prediction”, “R”, “ARIMA”, “Time Series”, “Stock Market”, “Trend”, “Investment”, “Randomness”.LABURPENA Proiektu honen helburua burtsa-aktiboen salneurrien ibilkera aztertzea da, haien iragarpen posibilitateak aztertzeko eredu matematikoen bitartez. Honetan, ARIMA ereduen bidez R softwaren bitartez erabilitakoak, eraginkor merkatuaren eta zorizko pasatzearen hipotesiak baieztatzen edo ezeztatzen saiatuko da, eta era berean ARIMA-ren iragartzeko utilitatea ebaluatuko da. Azterlanarako bi indize aztertuko dira: estutubatuarra S&P 500 eta espaniarra IBEX 35. Hitz Gakoak: “Iragarpena”, “R”, “ARIMA”, “Demborazko Saila”, “Burtsa Merkatua”, “Joera”, “Ibertsio”, “Auzazkotasun

Herschel, Spitzer and Magellan infrared observations of the star-forming region RCW 121 (IRAS 17149−3916)

We present new deep near-infrared broad- and narrow-band imaging and low-resolution spec-troscopy of the star formation region RCW 121 (IRAS 17149−3916) which we analyse incombination withHerschel(70, 160, 250, 350 and 500μm) andSpitzer(3.6, 4.5, 5.8 and 8μm)images. The near-infrared photometry reveals the presence of a stellar cluster of approximatesize of 92 arcsec which is composed of at least 264 members, approximately 25 per cent ofthese showing excess emission atλ>2.0μm, indicative of circumstellar discs. Isochronescorresponding to ages 0.5–1.0 Myr andAV=7.8 fit well the position of a large fraction of likelycluster members in theKsversusH−Ksdiagram. We find three massive star-forming coreslocated in the boundaries of an expanding HIIregion ionized by a central O-type star. Fromtheir far-infrared spectral energy distributions (SEDs) we derive masses and temperatures ofthe dense cores. When these young stellar objects (YSOs) have warm emission components,the 1.2–500μm SEDs are fitted with Robitaille et al.’s star–disc-envelope model to obtain theirphysical parameters. The masses of the three YSOs are between 8 and 10 M . The youngestsite (core I) is undetected atλ<100μm and is at the earliest evolutionary stage that cancurrently be detected. The other two cores (II and III) contain YSOs of similar masses andhave near-infrared counterparts, which imply a more advanced evolutionary stage. The YSOat core II has been found to have associated a jet, with strong H2line emission, co-existingwith an H2O maser source. RCW 121 is another example of multiple star formation beingtriggered by the expansion of a single HIIregion.Fil: Tapia, M.. Universidad Nacional Autónoma de México; MéxicoFil: Persi, P.. Istituto Astrofisica e Planetologia Spaziale. Roma; ItaliaFil: Roth, Markus Albert. Las Campanas Observatory. La Serena; ChileFil: Elia, D.. Istituto Astrofisica e Planetologia Spaziale. Roma; ItaliaFil: Molinari, S.. Istituto Astrofisica e Planetologia Spaziale. Roma; ItaliaFil: Saldaño, Hugo Pablo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Cordoba. Observatorio Astronomico de Cordoba; ArgentinaFil: Gomez, Mercedes Nieves. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Cordoba. Observatorio Astronomico de Cordoba; Argentin