Browse
Recent Submissions
Item The Latin American Giant Observatory (LAGO) capabilities for detecting Gamma Ray Bursts(2022-03-18) Sarmiento-Cano, Christian; Asorey, H.; Sacahui, J.R.; Otiniano, L.; Sidelnik, I.; LAGO Collaboration; Echiburu, Mauricio A.The Latin American Giant Observatory (LAGO) consists of a network of small water Cherenkov detectors (WCD) located at different sites in Latin America. It is a large aperture observatory sensitive to high energy gamma rays and due to its high duty cycle, LAGO constitutes a facility to detect transient events from the ground. Gamma Ray Bursts (GRBs) are of the brightest transients detected, with typical energies in their prompt phase ranging from keV to MeV, but theoretical models predict emissions at higher energies in the early times of the afterglow emission, and recently GRB190114C was the first GRB detected at TeV energies by the MAGIC experiment. In this work, we present the results of the expected sensitivity of LAGO for possible events like GRB190114C. We performed simulations in four of the high altitude LAGO sites projected to assess the sensitivity of the Observatory for this kind of events, using the ARTI toolkit developed by LAGO. We simulate photon showers with different spectral slopes and energies from 200 GeV to 1 TeV using the parameters presented by MAGIC for the recorded event. We also present maps of field of view of the studied sites with the observed GRBs by Fermi-GBM from 2019 to 2021.Item Morphology of the gas-rich debris disk around HD 121617 with SPHERE observations in polarized light(2023-05) Perrot, Clément; Olofsson, Johan; Kral, Quentin; Thébault, Philippe; Montesinos, Matías; Kennedy, Grant; Bayo, Amelia; Iglesias, Daniela; van Holstein, Rob; Pinte, ChristopheContext. Debris disks are the signposts of collisionally eroding planetesimal circumstellar belts, whose study can put important constraints on the structure of extrasolar planetary systems. The best constraints on the morphology of such disks are often obtained from spatially resolved observations in scattered light. In this paper, we investigate the young (~16 Myr) bright gas-rich debris disk around HD 121617. Aims. We use new scattered light observations from VLT/SPHERE to characterize the morphology and the dust properties of the debris disk. From these properties, we can then derive constraints on the physical and dynamical environment of this system, for which significant amounts of gas have been detected. Methods. The disk morphology is constrained by linear polarimetric observations in the J band. Based on our modeling results and archival photometry, we also model the spectral energy distribution (SED) to put constraints on the total dust mass and dust size distribution. Finally, we explore different scenarios that could explain these new constraints. Results. We present the first resolved image in scattered light of the debris disk around HD 121617. We fit the morphology of the disk, finding a semi-major axis of 78.3 ± 0.2 au, an inclination of 43.1 ± 0.2°, and a position angle of the major axis with respect to north of 239.8 ± 0.3°, which is compatible with the previous continuum and CO detection with ALMA. Our analysis shows that the disk has a very sharp inner edge, possibly sculpted by a yet-undetected planet or gas drag. While less sharp, its outer edge is steeper than expected for an unperturbed disk, which could also be due to a planet or gas drag, but future observations probing the system farther from the main belt would help explore this possibility further. The SED analysis leads to a dust mass of 0.21 ± 0.02 M⊕ and a minimum grain size of 0.87 ± 0.12 μm, smaller than the blowout size by radiation pressure, which is not unexpected for very bright collisionally active disks.Item Teaching physics in real-life contexts: The Beirut explosion(2023-04-01) Echiburu, Mauricio; Hernández, Carla; Pino, MiguelTeaching physics in real-life contexts continues to be a challenge for teachers at different edu cational levels. In this article, three Context-Rich Problems are proposed to be implemented in the classroom for higher education, using the explosion that occurred in Beirut as a case study. These problems require the search and analysis of real data, integrating technologies as tools to learn physics. In particular, the analysis of images, videos, maps and audio recordings is suggested. The proposed activities are designed to promote active learning of classical mechanics subjects and the development of collaborative skills. The results of each problem allow a discussion based on scientific evidence in the classroom.Item Study of the effect of seismically-induced geoelectric and geomagnetic fields on secondary particle detection at a LAGO site(2022-03-18) Coloma Borja, Diego Alberto; Carrera Jarrin, Edgar; Echiburu, Mauricio; LAGO CollaborationThe LAGO (Latin American Giant Observatory) project is an extended Astroparticle Observatory at global scale. It is mainly oriented to basic research on three branches of Astroparticle physics: the Extreme Universe, Space Weather phenomena, and Atmospheric Radiation at ground level. This work is framed in the latter branch, its aim is to study the potential effects on extensive air showers from changes in geoelectric and geomagnetic fields, induced by the onset of seismic activity. For this purpose, simulations for flux of secondaries are performed with ARTI, a tool developed by LAGO that combines Magnetocosmics, CORSIKA, and Geant4 to account, respectively, for the propagation of a shower by a primary particle, geomagnetic corrections, and detector response. Using ARTI, we have calculated the radiation background at the LAGO Site in Universidad San Francisco de Quito (2200 m.a.s.l). Regular conditions for the Earth's electromagnetic field are taken from the NCEI Geomagnetic Calculator for specific fair-weathered days above the location. Variations from this regularity are introduced based on relevant studies on seismic activity. The results show that there exists an effect on the number of secondary particles at ground level, which could, in principle, be detected by a LAGO WCD detector.Item The vertical structure of debris disks and the impact of gas.(2022-02-16) Olofsson, Johan; Thébault, Philippe; Kral, Quentin; Bayo, Amelia; Boccaletti, Anthony; Godoy, Nicolás; Henning, Thomas; van Holstein, Rob G.; Maucó, Karina; Milli, Julien; Montesinos, Matías; Rein, Hanno; Sefilian, Antranik A.The vertical structure of debris discs provides clues about their dynamical evolution and the collision rate of the unseen planetesimals. Thanks to the ever-increasing angular resolution of contemporary instruments and facilities, we are beginning to constrain the scale height of a handful of debris discs, either at near-infrared or millimeter wavelengths. None the less, this is often done for individual targets only. We present here the geometric modeling of eight discs close to edge-on, all observed with the same instrument (SPHERE) and using the same mode (dual-beam polarimetric imaging). Motivated by the presence of CO gas in two out of the eight discs, we then investigate the impact that gas can have on the scale height by performing N-body simulations including gas drag and collisions. We show that gas can quickly alter the dynamics of particles (both in the radial and vertical directions), otherwise governed by gravity and radiation pressure. We find that, in the presence of gas, particles smaller than a few tens of microns can efficiently settle toward the midplane at the same time as they migrate outward beyond the birth ring. For second generation gas (Mgas ≤ 0.1 M⊕), the vertical settling should be best observed in scattered light images compared to observations at millimeter wavelengths. But if the gas has a primordial origin (Mgas ≥ 1 M⊕), the disc will appear very flat both at near-infrared and sub-mm wavelengths. Finally, far beyond the birth ring, our results suggest that the surface brightness profile can be as shallow as ∼−2.25.Item The EOSC-Synergy cloud services implementation for the Latin American Giant Observatory (LAGO)(2021-12-30) Rubio-Montero, A.J.; Pagán-Muñoz, R.; Mayo-García, R.; Pardo-Diaz, A.; Sidelnik, I.; Asorey, H.; Echiburu, M.; LAGO CollaborationThe Latin American Giant Observatory (LAGO) is a distributed cosmic ray observatory at a regional scale in Latin America, by deploying a large network of Water Cherenkov detectors (WCD) and other astroparticle detectors in a wide range of latitudes from Antarctica to México, and altitudes from sea level to more than 5500 m a.s.l. Detectors telemetry, atmospherics conditions and flux of secondary particles at the ground are measured with extreme detail at each LAGO site by using our own-designed hardware and firmware (ACQUA). To combine and analyse all these huge amount of data, LAGO developed ANNA, our data analysis framework. Additionally, ARTI, a complete framework of simulations designed to simulate the expected signals at our detectors coming from primary cosmic rays entering the Earth atmosphere, allowing a precise characterization of the sites in realistic atmospheric, geomagnetic and detector conditions. As the measured and synthetic data started to flow, we are facing challenging scenarios given the large amount of data emerging, performed on a diversity of detectors and computing architectures and e-infrastructures. These data need to be transferred, analyzed, catalogued, preserved, and provided for internal and public access and data-mining under an open e-science environment. In this work, we present the implementation of ARTI at the EOSC-Synergy cloud-based services as the first example of LAGO' frameworks that will follow the FAIR principles for provenance, data-curation and re-using of data. For this we calculate the flux of secondary particles expected in up to 1 week at detector level for all the 26 LAGO, and the 1-year flux of high energy secondaries (pS>800 GeV/c) expected at the ANDES Underground Laboratory and other sites. Therefore, we show how this development can help not only to LAGO but other data-intensive cosmic rays observatories, muography experiments and underground laboratories.Item A holographic bottom-up description of light nuclide spectroscopy and stability(2022-11-05) Martin Contreras, Miguel Ángel; Vega, Alfredo; Diles, SauloThis work explores a holographic proposal to describe light nuclide spectroscopy by considering extensions to the well-known bottom-up AdS/QCD proposals, the hardwall and softwall models. We also propose an alternative description inspired by the Woods-Saxon potential. We find the static dilaton associated with this potential in this Wood-Saxon-like model. We compute the nuclide spectra finding that, despite their pure AdS/QCD origin, hardwall and softwall, as monoparametric models, have good accuracy and precision since the RMS error is near 11% and 4% respectively. In the case of the Wood-Saxon model, the RMS was around 1%. We also discuss configurational entropy as a tool to categorize which model is suitable to describe nuclides in terms of stability. We found that configurational entropy resembles a stability line, independent from nuclear spin, for symmetric light nuclides when considering softwall and Wood-Saxon-like models. For the hardwall case, configurational entropy, despite increasing with the constituent number, depends on the nuclear spin. Thus, the Woods-Saxon-like model emerges as the best choice to describe light nuclide spectroscopy in the bottom-up scenario.Item Análisis físico del minuto 120 del partido Chile-Brasil en el Mundial de Fútbol 2014(2015-12) Echiburu, MauricioEste trabajo presenta el análisis, desde un punto de vista físico, de la última jugada del alargue del encuentro entre Chile y Brasil, en el Mundial de Fútbol 2014. En dicho partido, el jugador chileno Mauricio Pinilla estrelló el balón en el larguero del arco de Brasil obligando a un alargue a penales. El análisis de la jugada comprende un estudio sobre el movimiento del balón y su posterior rebote en el arco, determinando las velocidades a través de la observación de videos de la jugada, y de estimaciones razonables para la situación. Además, se realiza un análisis de la fuerza de arrastre del aire sobre el balón para la jugada, obteniendo de ello cálculos de la energía cinética del balón antes y después del rebote, para luego estimar la fuerza y deformación que actúa sobre el balón. Todo este análisis se desarrolló con información y tecnología disponible para cualquier persona, de forma que los resultados sean replicables en el aula de clases. Por esto último se sugieren actividades docentes a desarrollar utilizando este análisis como base, para trabajar diferentes fenómenos de la Física, desde una mirada más cercana para los estudiantes.Item Biology and life table of Eotetranychus lewisi (Acari: Tetranycidae) on Prunus persica cultivars from the Ecuadorian Andean region(2022-04-08) Miño, César; Santana, Rita; León, Olguer; Colmenárez, Yelitza; Villa-Murillo, Adriana; Vásquez, CarlosEotetranychus lewisi (McGregor) is an important pest mite found in peach crops. This pest has recently been reported in the province of Tungurahua, Ecuador, little information is available. The biology and life table of E. lewisi using three peach cultivars (Zapallo, Blanco Abridor, and Tejón) was evaluated under laboratory conditions (19°C, 45% R.H., and 12:12 L.D). Mites were collected from Euphorbia pulcherrima growing at the Faculty of Agricultural Sciences, Technical University of Ambato. The mites were able to grow through the immature phase of the Blanco Abridor and Tejón cultivars. The mean duration of the immature phase (egg to adult) did not show significant differences between the Blanco Abridor and Tejón cultivars, ranging from 16.24 to 16.56 days. The mean female fecundity reared on Tejón was 18% higher than on Blanco Abridor, though their longevity was similar on both. The mean net reproductive rate (R0) was higher on Tejón (61.25), suggesting that more females will be born when the mites are raised on this cultivar. Based on our results, Tejón and Blanco Abridor were susceptible to E. lewisi; while, the mites could not reach adulthood on Zapallo, suggesting at least some resistance mechanisms, however more detailed studies are required.Item Forbush decrease on September 6-13, 2017 observed by the Tanca water-Cherenkov detector(2021-05-07) de Aguiar, Renan; Campos Fauth, Anderson; LAGO Collaboration; Echiburu, MauricioSolar activity was intense in September 2017 and its effects were observed in different detectors placed at the Earth’s surface. Three halo Coronal Mass Ejections (CME) hit the planet and caused magnetic storms. The effects of the CMEs on the flux of galactic cosmic rays at ground level were observed by the Tanca detector, which is one of the water-Cherenkov detectors (WCD) that make up the Latin American Giant Observatory (LAGO). In this paper we present the detection of Forbush events observed by Tanca during the month of September 2017. This WCD is installed on the campus of the University of Campinas, in Brazil, having three photomultiplier tubes that detect Cherenkov photons produced by cosmic radiation in 11400 liters of ultra pure water. We present the description and performance of the experimental apparatus and the observation on days 6th, 8th and 13th of the Forbush events originated by the CMEs. A decrease in the cosmic rays flux due to a stream inTeraction region was also observed on 14th September. These results were compared with observations made by neutron monitors and indices of the Earth’s magnetic activity.Item Nuevas aproximaciones al test de Lawson: un análisis desde las teorías piagetianas y la neurociencia(2022-08) Echiburu, Mauricio A.; Ramirez, Chenda F.; Mora, Soraya P.Este estudio explora los niveles de razonamiento de alumnas y alumnos de primer año de educación superior. Para medir el razonamiento y detectar la etapa de desarrollo del pensamiento, se aplica la prueba de Lawson a 2131 estudiantes de dos universidades de Chile y de una universidad en Perú. Los resultados muestran que la mayoría de los estudiantes medidos de la Universidad de Piura y de la Universidad de la Serena presentan un nivel de pensamiento entre el desarrollo de transición temprana y pensamiento concreto, y la mayoría de los estudiantes de la Universidad Viña del Mar presentan pensamiento concreto. Siendo el mejor desempeño en el ítem de conservación de masa. También se observa una diferencia consistente entre hombres y mujeres en la conservación de volumen e identificación y control de variables. En conclusión, se evidencia una asociación entre neurociencia y los niveles de razonamiento planteados por Piaget, por lo que se recomienda su uso, principalmente en primer año.Item Forbush decrease on September 6-13, 2017 observed by the Tanca water-Cherenkov detector(2021) de Aguiar, Renan; Campos Fauth, Anderson; LAGO CollaborationSolar activity was intense in September 2017 and its effects were observed in different detectors placed at the Earth’s surface. Three halo Coronal Mass Ejections (CME) hit the planet and caused magnetic storms. The effects of the CMEs on the flux of galactic cosmic rays at ground level were observed by the Tanca detector, which is one of the water-Cherenkov detectors (WCD) that make up the Latin American Giant Observatory (LAGO). In this paper we present the detection of Forbush events observed by Tanca during the month of September 2017. This WCD is installed on the campus of the University of Campinas, in Brazil, having three photomultiplier tubes that detect Cherenkov photons produced by cosmic radiation in 11400 liters of ultra pure water. We present the description and performance of the experimental apparatus and the observation on days 6th, 8th and 13th of the Forbush events originated by the CMEs. A decrease in the cosmic rays flux due to a stream inTeraction region was also observed on 14th September. These results were compared with observations made by neutron monitors and indices of the Earth’s magnetic activity.Item GDAS atmospheric models in astroparticle shower simulations(2021) Grisales-Casadiegos, J.; Sarmiento-Cano, C.; Núñez, Luis A.; LAGO CollaborationAtmospheric conditions affect the development of cascades of secondary particles produced by primary cosmic rays. Global Data Assimilation System, implementing atmospheric models based on meteorological measurements and numerical weather predictions, could significantly improve the outcomes of the simulations for extensive air showers. In this work, we present a methodology to simulate the effect of the atmospheric models in secondary particle flux at the Earth’s surface. The method was implemented for Bucaramanga-Colombia, using ARTI: a complete computational framework developed by the Latin American Giant Observatory Collaboration to estimate the particle spectra on Water Cherenkov Detectors depending on the geographical coordinates. We observe differences in the total flux that varies monthly concerning the subtropical summer atmospheric profile as preliminary results.Item "ME TIRÉ POR VOS" UN ANÁLISIS FÍSICO DEL SALTO DE CHARLY GARCÍA(2022-07-13) Echiburu, M.; Parra, R.En este trabajo se estudia el famoso salto de Charly García, proponiendo así poner en contexto una situación de carácter público en el ámbito de la física. Se utilizó el análisis de video, lo que permitió comparar modelos de cinemática clásica con los datos experimentales de la caída, con ello se determinó la posición y velocidad del artista mientras se mueve en el aire. Posterior a ello, se analizó el movimiento en el agua, obteniendo diferentes posibilidades según las variaciones de los parámetros en estudio. Esta propuesta reafirma la utilización de este tipo de problemas como una herramienta pedagógica exitosa y de gran versatilidad para su uso en el aula.Item The vertical structure of debris disks and the impact of gas.(2022-02-18) Olofsson, Johan; Thébault, Philippe; Kral, Quentin; Bayo, Amelia; Boccaletti, Anthony; Godoy, Nicolás; Henning, Thomas; van Holstein, Rob G.; Maucó, Karina; Milli, Julien; Montesinos, Matías; Rein, Hanno; Sefilian, Antranik A.The vertical structure of debris disks provides clues about their dynamical evolution and the collision rate of the unseen planetesimals. Thanks to the ever-increasing angular resolution of contemporary instruments and facilities, we are beginning to constrain the scale height of a handful of debris disks, either at near-infrared or millimeter wavelengths. Nonetheless, this is often done for individual targets only.We present here the geometric modeling of eight disks close to edge-on, all observed with the same instrument (SPHERE) and using the same mode (dual-beam polarimetric imaging). Motivated by the presence of CO gas in two out of the eight disks, we then investigate the impact that gas can have on the scale height by performing N-body simulations including gas drag and collisions. We show that gas can quickly alter the dynamics of particles (both in the radial and vertical directions), otherwise governed by gravity and radiation pressure. We find that, in the presence of gas, particles smaller than a few tens of microns can efficiently settle toward the midplane at the same time as they migrate outward beyond the birth ring. For second generation gas (𝑀gas ≤ 0.1 𝑀⊕), the vertical settling should be best observed in scattered light images compared to observations at millimeter wavelengths. But if the gas has a primordial origin (𝑀gas ≥ 1 𝑀⊕), the disk will appear very flat both at near-infrared and sub-mm wavelengths. Finally, far beyond the birth ring, our results suggest that the surface brightness profile can be as shallow as ∼ −2.25.Item Cronomoons: origin, dynamics, and light-curve features of ringed exomoons(2021-12-14) Sucerquia, Mario; Alvarado-Montes, Jaime A.; Bayo, Amelia; Cuadra, Jorge; Cuello, Nicolás; Giuppone, Cristian A.; Montesinos, Matías; Olofsson, J.; Schwab, Christian; Spitler, Lee; Zuluaga, Jorge I.In recent years, technical and theoretical work to detect moons and rings around exoplanets has been attempted. The small mass/size ratios between moons and planets means this is very challenging, having only one exoplanetary system where spotting an exomoon might be feasible (i.e. Kepler-1625b i). In this work, we study the dynamical evolution of ringed exomoons, dubbed cronomoons after their similarity with Cronus (Greek for Saturn), and after Chronos (the epitome of time), following the Transit Timing Variations (TTV) and Transit Duration Variation (TDV) that they produce on their host planet. Cronomoons have extended systems of rings that make them appear bigger than they actually are when transiting in front of their host star. We explore different possible scenarios that could lead to the formation of such circumsatellital rings, and through the study of the dynamical/thermodynamic stability and lifespan of their dust and ice ring particles, we found that an isolated cronomoon can survive for time-scales long enough to be detected and followed up. If these objects exist, cronomoons’ rings will exhibit gaps similar to Saturn’s Cassini Division and analogous to the asteroid belt’s Kirkwood gaps, but instead raised due to resonances induced by the host planet. Finally, we analyse the case of Kepler-1625b i under the scope of this work, finding that the controversial giant moon could instead be an Earth-mass cronomoon. From a theoretical perspective, this scenario can contribute to a better interpretation of the underlying phenomenology in current and future observations.Item The protoplanetary disc around HD 169142: circumstellar or circumbinary?(2021-12) Poblete, P. P.; Cuello, N.; Pérez, S.; Marino, S.; Calcino, J.; Macías, E.; Ribas, Á.; Zurlo, A.; Cuadra, J.; Montesinos, Matías; Zúñiga-Fernández, S.; Bayo, A.; Pinte, C.; Ménard, F.; Price, D. J.Stellar binaries represent a substantial fraction of stellar systems, especially among young stellar objects. Accordingly, binaries play an important role in setting the architecture of a large number of protoplanetary discs. Binaries in coplanar and polar orientations with respect to the circumbinary disc are stable configurations and could induce non-axisymmetric structures in the dust and gas distributions. In this work, we suggest that the structures shown in the central region of the protoplanetary disc HD 169142 are produced by the presence of an inner stellar binary and a circumbinary (P-type) planet. We find that a companion with a mass-ratio of 0:1, semi-major axis of 9:9 au, eccentricity of 0.2, and inclination of 90°, together with a 2 MJ coplanar planet on a circular orbit at 45 au reproduce the structures at the innermost ring observed at 1.3 mm and the shape of spiral features in scattered light observations. The model predicts changes in the disc’s dust structure, and star’s astrometric parameters, which would allow testing its veracity by monitoring this system over the next 20 years.Item Characterizing the morphology of the debris disk around the low-mass star GSC 07396-00759(2021-07-15) Adam, C.; Olofsson, J.; van Holstein, R. G.; Bayo, A.; Milli, J.; Boccaletti, A.; Kral, Q.; Ginski, C.; Henning, Th.; Montesinos, Matías; Pawellek, N.; Zurlo, A.; Langlois, M.; Delboulbé, A.; Pavlov, A.; Ramos, J.; Weber, L.; Wildi, F.; Rigal, F.; Sauvage, J.-F.Context. Debris disks have commonly been studied around intermediate-mass stars. Their intense radiation fields are believed to e ciently remove the small dust grains that are constantly replenished by collisions. For lower-mass central objects, in particular M-stars, the dust removal mechanism needs to be further investigated given the much weaker radiation field produced by these objects. Aims. We present new observations of the nearly edge-on disk around the pre-main sequence M-type star GSC 07396-00759, taken with VLT/SPHERE IRDIS in Dual-beam Polarimetric Imaging (DPI) mode, with the aim to better understand the morphology of the disk, its dust properties, and the star-disk interaction via the stellar mass-loss rate. Methods. We model the polarimetric observations to characterize the location and properties of the dust grains using the Henyey-Greenstein approximation of the polarized phase function. We use the estimated phase function to evaluate the strength of the stellar winds. Results. We find that the polarized light observations are best described by an extended and highly inclined disk (i 84:3 0:3) with a dust distribution centered at a radius r0 107 2 au. Our modeling suggests an anisotropic scattering factor g 0:6 to best reproduce the polarized phase function S 12. We also find that the phase function is reasonably reproduced by small micron-sized dust grains with sizes s > 0:3 µm. We discuss some of the caveats of the approach, mainly that our model probably does not fully recover the semi-major axis of the disk and that we cannot readily determine all dust properties due to a degeneracy between the grain size and the porosity. Conclusions. Even though the radius of the disk may be over-estimated, our best fit model not only reproduces well the observations but is also consistent with previous published data obtained in total intensity. Similarly to previous studies of debris disks, we suggest that using a given scattering theory might not be su cient to fully explain key aspects such as the shape of the phase function, or the dust grain size. Taking into consideration the aforementioned caveats, we find that the average mass-loss rate of GSC 07396-00759 can be up to 500 times stronger than that of the Sun, supporting the idea that stellar winds from low-mass stars can evacuate small dust grains in an e cient way.Item A Hybrid Artificial Intelligence Model for Aeneolamia varia (Hemiptera: Cercopidae) Populations in Sugarcane Crops(2021) Figueredo, Luis; Villa-Murillo, Adriana; Colmenarez, Yelitza; Vásquez, CarlosSugarcane spittlebugs are considered important pests in sugarcane crops ranging from the southeastern United States to northern Argentina. To evaluate the effects of climate variables on adult populations of Aeneolamia varia (Fabricius) (Hemiptera: Cercopidae), a 3-yr monitoring study was carried out in sugarcane fields at weeklong intervals during the rainy season (May to November 2005–2007). The resulting data were analyzed using the univariate Forest-Genetic method. The best predictive model explained 75.8% variability in physiological damage threshold. It predicted that the main climatic factors influencing the adult population would be, in order of importance, evaporation; evapotranspiration by 0.5; evapotranspiration, cloudiness at 2:00 p.m.; average sunshine and relative humidity at 8:00 a.m. The optimization of the predictive model established that the lower and upper limits of the climatic variables produced a threshold in the population development rate of 184 to 267 adult insects under the agroecological conditions of the study area. These results provide a new perspective on decision-making in the preventive management of A. varia adults in sugarcane crops.Item Motion analysis of kinetic impact projectiles for physics education in real context(2020-04-16) Hernández, Carla V.; Echiburu, Mauricio A.; Humire, Fernando R.; Mosso, Edward F.The article presents a proposal to contextualize the study of movement in first courses of univer- sity physics, as a contribution to decision-making in situations of a social nature. For this, the case of the use of kinetic impact projectiles and the actual data provided by official sources is considered. This information is used in an object motion model describing the kinematic characteristics of a spherical projectile (a rubber bullet). For these purposes, a number Reynolds Re ≫ 1 was used, which allows applying a nonlinear motion equation to find the velocity and impact energy per unit area of projectile. Results and analysis of this model can generate an interesting discussion in the classroom about the need to build protocols for the use of kinetic impact projectiles, and the importance of using scientific knowledge in social conflicts.