H. S. Churchill, La ciudad es su población, Buenos Aires, Ed. Infinito, 1958, 243 p.

Fil: Herrera de Soria, María E.. Universidad Nacional de Cuyo. Facultad de Filosofía y Letra

Machine Learning and Traditional Econometric Models: A Systematic Mapping Study

This research has been supported by the project "INTELFIN: Artificial Intelligence for investment and value creation in SMEs through competitive analysis and business environment", Reference: RTC-2017-6536-7, funded by the Ministry of Science, Innovation and Universities (ChallengesCollaboration 2017), the State Agency for Research (AEI) and the European Regional Development Fund (ERDF).Machine Learning (ML) is a disruptive concept that has given rise to and generated interest in different applications in many fields of study. The purpose of Machine Learning is to solve real-life problems by automatically learning and improving from experience without being explicitly programmed for a specific problem, but for a generic type of problem. This article approaches the different applications of ML in a series of econometric methods. Objective: The objective of this research is to identify the latest applications and do a comparative study of the performance of econometric and ML models. The study aimed to find empirical evidence for the performance of ML algorithms being superior to traditional econometric models. The Methodology of systematic mapping of literature has been followed to carry out this research, according to the guidelines established by [39], and [58] that facilitate the identification of studies published about this subject. Results: The results show, that in most cases ML outperforms econometric models, while in other cases the best performance has been achieved by combining traditional methods and ML applications. Conclusion: inclusion and exclusions criteria have been applied and 52 articles closely related articles have been reviewed. The conclusion drawn from this research is that it is a field that is growing, which is something that is well known nowadays and that there is no certainty as to the performance of ML being always superior to that of econometric models.project "INTELFIN: Artificial Intelligence for investment and value creation in SMEs through competitive analysis and business environment" - Ministry of Science, Innovation and Universities (ChallengesCollaboration 2017) RTC-2017-6536-7State Agency for Research (AEI)European Commissio

Vortex motion channeling effects in Nb with mesoscopic arrays of Ni lines

Ordered arrays of submicrometric Ni lines have been fabricated in sputtered Nb films. Magnetotransport R(H) and (I, V) curves were measured close to the critical temperature using a cross-shape bridge that allows us to apply current in two directions: parallel or perpendicular to the lines. The experimental results show anisotropic vortex motion with clear channeling effects. In R(H) data, magnetic features appear but they are absent in the (I, V) curves

Root-Associated Fungal Communities in Two Populations of the Fully Mycoheterotrophic Plant Arachnitis uniflora Phil. (Corsiaceae) in Southern Chile

The microbiological interactions of the roots of non-photosynthetic plants in South America have been scarcely explored. This study analyzes culturable fungal diversity associated with the mycoheterotrophic plant Arachnitis uniflora Phil. (Corsiaceae) in southern Chile, growing in two different understoreys of native (Nothofagus-dominated) and mixed forest (native, Cupressus sempervirens, and Pinus radiata). Rhizospheric and endophytic fungi were isolated, cultured, and purified to identify microorganisms associated with A. uniflora roots. We showed the different fungi associated with the plant, and that these distributions are influenced by the sampling site. We isolated 410 fungal strains (144 endophytic and 266 from the rhizosphere). We identified 13 operative taxonomical units from plants sampled in the mixed forest, while 15 were from the native forest. Rhizospheric microorganisms were mainly related to Penicillium spp., whereas some pathogenic and saprophytic strains were more frequent inside the roots. Our results have also shown that the fungal strains are weak for phosphate solubilization, but other pathways such as organic acid exudation and indole acetic acid production can be considered as major mechanisms to stimulate plant growth. Our results point to new fungal associates of A. uniflora plants reported in Andean ecosystems, identifying new beneficial endophytic fungi associated with roots of this fully mycoheterotrophic plant.This research was funded by Fondo Nacional de Desarrollo Científico y Tecnológico (FONDECYT), grant number 1170931 to C.A. (Cesar Arriagada) and Fondo De Fomento al Desarrollo Científico y Tecnológico (FONDECYT), grant number VIU17E0185 to H.H. (Hector Herrera)

Aceite esencial de Tagetes filifolia contra Tribolium castaneum y su relación con la actividad acetilcolinesterasa y peroxidación de lípidos

The development of natural insecticides would help to decrease the negativeimpact of synthetic insecticides. Fumigant toxicity of essential oil of Tagetesfilifolia Lag (Asterales: Asteraceae) and its major compounds were evaluatedagainst Tribolium castaneum Herbst (Coleoptera: Tenebrionidae). Theessential oils were analyzed by gas chromatography?mass spectrometry. Theessential oil and (E)-anethole were the most toxic at 24 h against adult insects(CL50= 2.4 y 2.6 µL/mL water, respectively). Changes in the products of lipidperoxidation were evidenced by an increase in malondialdehyde content.Acetylcholinesterase activity in vitro, of T. castaneum adults, was also reported.(E)-anethole and estragole showed similar acetylcholinesterase inhibition (54and 63%, respectively at 5 mM). The present study constitutes one of the firstcontributions to understanding the relationship between the insecticidal actionof essential oil and oxidative stress.El desarrollo de insecticidas naturales podría ayudar a disminuir el impacto negativo de insecticidas sintéticos. La acción insecticida fumigante del aceite esencial (AEs) de Tagetes filifolia Lag (Asterales: Asteraceae) y sus compuestos principales fueron evaluados contra adultos de Tribolium castaneum Herbst (Coleoptera: Tenebrionidae). Los aceites esenciales fueron analizados por cromatografía gaseosa-espectrometría de masas. El aceite esencial y (E)-anetol mostraron mayor toxicidad contra insectos adultos a las 24 h (CL50= 2,4 y 2,6 µL/mL water, respectivamente). Se evidenciaron cambios en los productos de peroxidación lipídica por un incremento en el contenido de malondialdehído. También se estudió la actividad in vitro de la enzima acetilcolinesterasa de insectos adultos de T. castaneum. (E)-anetol y estragol mostraron similar inhibición de la enzima (54 y 63%, respectivamente a 5 mM). El presente estudio constituye una de las primeras contribuciones para comprender la relación entre la acción insecticida del aceite esencial y el estrés oxidativo.Fil: Olmedo, Rubén Horacio. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Lucini, E.. Universidad Nacional de Córdoba. Facultad de Ciencias Agropecuarias; ArgentinaFil: Herrera, Jimena María. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Zunino, María Paula. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Pizzolitto, Romina Paola. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Dambolena, Jose Sebastian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Zygadlo, Julio Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentin

Interface barriers for flux motion in high-temperature superconducting superlattices

We study angular dependent magnetoresistance in the vortex-liquid phase of epitaxial YBa2Cu3O7 thin films and YBa_2Cu_3O_7/PrBa_2Cu_3O_7 superlattices. Superlattices were grown with different PrBa_2Cu_3O_7 thickness in order to tune coupling between YBa_2Cu_3O_7 layers. While dissipation of single film and coupled superlattices is scaled with the anisotropic three-dimensional model in the whole angular range, decoupling through PrBa_2Cu_3O_7 spacer breaks down the scaling and yields strong reduction of the dissipation when the magnetic fields are applied up to ±20degrees around the interface direction. Bean-Livingston barriers at the interface are the mechanism which governs this behavior

Study of the physical properties of soils through interpretation of aerial photographs

Final technical reportThe purpose of the research work proposed is the study of the physical properties of the soils by means of the interpretation of aerial photographs. This study is to be carried out in two years and thus it is not possible to give definite conclusions at the end of the first year, although the results we have obtained are highly satisfactory. In our opinion and after the experience of the first year, the working problem of the study of the physical properties of the soils through aerial photographs, can be examined from two different aspects. The first of them could be called the "deductive" method and consists in acquiring knowledge of the physical properties of the soils by means of sucoessive interpretations of aerial photographs; through photointerpretation we study the physical Geography of an area, its hydrographic net, natural vegetation and .man-introduced cultivations, the forms of erosion end the nature of the geological material, All these interpretations, together with the clitmate, allow to "deduce" the nature of the soils of that area, as all the pedological processes which the different geological materials have undergone can be know perfectly well, which also shows the intensity of physical and chemical desintegration of the materials that form the starting point of soil formation.The research reported in this document has been made possible through the support and sponsorship of the U.S. Department of the Army through its European Research Office.Contract No. DA-91-591-EUC-2652 1st. April 1963 to 31th March 1964.N

Evaluation of Risk and Preventive Factors for Necrotizing Enterocolitis in Premature Newborns. A Systematic Review of the Literature.

Necrotizing enterocolitis (NEC) is a serious condition related to prematurity and the initiation of enteral feeding. In this article, we review the evidence published in recent years on necrotizing enterocolitis risk factors (prematurity, feeding with low-weight formula, existence of intestinal dysbiosis) and protective factors (human milk or donated milk supply, supplementation of human milk with oligosaccharides, probiotics administration, and the determination of disease predictive biomarkers). A systematic review was conducted of preventive, risk and predictive factors for necrotizing enterocolitis in neonates prior to 37 weeks’ gestational age, based on a literature search for clinical trials, meta-analyses, randomized controlled trials and systematic reviews published betweenJanuary2018andOctober2021.Forthispurpose,thePubMed,MEDLINE,and Cochrane Library databases were consulted. The literature search obtained 113 articles, of which 19 were selected for further analysis after applying the inclusion and exclusion criteria. The conclusions drawn from this analysis were that adequate knowledge of risk factors that can be prevented or modified (such as alteration of the intestinal microbiota, oxidative stress, metabolic dysfunction at birth, or alteration of the immunity modulation) can reduce the incidence of NEC in premature infants. These factors include the supplementation of enteral nutrition with human milk oligosaccharides (with prebiotic and immunomodulatory effects), the combined administration of probiotics (especially the Lactobacillus spp and Bifidobacterium spp combination, which inhibits bacterial adhesion effects, improves the intestinal mucosa barrier function, strengthens the innate and adaptive immune system and increases the secretion of bioactive metabolites), the supplementation of human milk with lactoferrin and the use of donated milk fortified in accordance with the characteristics of the premature newborn. The determination of factors that can predict the existence of NEC, such as fecal calprotectin, increased TLR4 activity, and IL6 receptor, can lead to an early diagnosis of NEC. Although further studies should be conducted to determine the values of predictive biomarkers of NEC, and/or the recommended doses and strains of probiotics, lactoferrin or oligosaccharides, the knowledge acquired in recent years is encouraging

Annual Legumes as an Alternative for Animal Feeding in Cuba

Studies conducted in Cuba have demonstrated the importance of the agronomic and nutritional performance of the species Vigna unguiculata (cowpea), Canavalia ensiformis (jackbean), Stizolobium niveum (mucuna), Lablab purpureus (dolicho) and Glycine max (soybean) as feed sources for non-ruminant species. Under Cuban tropical conditions, and with minimum agricultural inputs, jackbean, dolicho and mucuna have attained forage yields between 4 and 6 t dry matter (DM)/ha and grain yields between 2.57 and 3.41 t/ha and cowpea and soybean have given yields of between 1 and 2 t/ha (Díaz 2000). This study was carried out to determine the chemical composition of grains and forages of these annual legumes in relation to their use in animal feeding

Vortex phases in superconducting Nb thin films with periodic pinning

Magnetotransport properties have been used to investigate vortex phases in Nb films with periodic arrays of magnetic pinning centers. This kind of samples show a continuous glass transition similar to that observed in Nb plain films, but the periodic pinning yields different critical exponents and enhanced glass transition temperature at the matching field