Free-floating molecular clumps and gas mixing: hydrodynamic aftermaths of the intracluster−-interstellar medium interaction

The interaction of gas-rich galaxies with the intra-cluster medium (ICM) of galaxy clusters has a remarkable impact on their evolution, mainly due to the gas loss associated with this process. In this work, we use an idealised, high-resolution simulation of a Virgo-like cluster, run with RAMSES and with dynamics reproducing that of a zoom cosmological simulation, to investigate the interaction of infalling galaxies with the ICM. We find that the tails of ram pressure stripped galaxies give rise to a population of up to more than a hundred clumps of molecular gas lurking in the cluster. The number count of those clumps varies a lot over time -- they are preferably generated when a large galaxy crosses the cluster (M$_{200c} > 10^{12}$ M$_\odot$), and their lifetime ($\lesssim 300$ Myr) is small compared to the age of the cluster. We compute the intracluster luminosity associated with the star formation which takes place within those clumps, finding that the stars formed in all of the galaxy tails combined amount to an irrelevant contribution to the intracluster light. Surprisingly, we also find in our simulation that the ICM gas significantly changes the composition of the gaseous disks of the galaxies: after crossing the cluster once, typically 20% of the cold gas still in those disks comes from the ICM.Comment: 9 pages, 6 figures. Accepted for publication in MNRA

Portable system for capturing images of the sclera

For many years in México and the world there is the tendency to improve the health of people, with emphasis on prevention and early detection, one of the most common examples is detection of breast cancer, if it is detected early it is curable. This paper proposes a system for digital image capturing, principally for the detection of the sclera (the white part of the eye), because not are databases available for sclera analysis, only for iris or pupil. The device must be of moderate cost and small size to perform a self-examination in a habitual place for people, can be their home, and were used recycled and low cost materials. It should be noted that the main purpose it is to capture images as uniform as possible, and thereby in the subsequent works, the detection of the sclera is less complicated

Estrategias de aprendizaje: efecto en el rendimiento académico por sexo en la licenciatura de administración

Las instituciones de educación superior plantean un nuevo modelo de educación, a través del desarrollo de conocimientos y aplicación de estrategias de aprendi- zaje que sirvan para aprovechar la diversidad, la gran cantidad de información disponible y nuevos descubrimientos que aportan la ciencia y la tecnología. Por lo anterior, se hace necesario conocer en qué medida los estudiantes aplican las estrategias de aprendizaje y cómo estas impactan en su rendimiento académico. El objetivo fue describir y relacionar estrategias de aprendizaje y rendimiento académico por sexo en la licenciatura de administración del Centro Universitario Temascaltepec. La población fue el total de hombres y mujeres que integran la licenciatura. Se aplicó el instrumento escala de estrategias de aprendizaje de Román y Gallego (2001). Se midió el grado de utilización de estrategias y la corre- lación en mujeres y hombres se procesó con el SPSS. Las estrategias de aprendizaje más utilizadas en mujeres y hombres corresponden a una educación tradicional; respecto a la correlación, en las mujeres sí impacta en su rendimiento académico, no así en el caso de los hombres. Lo anterior da pautas para fortalecer la actividad docente en esta licenciatura

Multiple Resistance to Glyphosate and 2,4-D in Carduus acanthoides L. from Argentina and Alternative Control Solutions

Carduus acanthoides L. is an invasive species native to Europe and distributed in other parts of the world, including North and South America. In Cordoba, Argentina, control failures of this species have been reported in Roundup Ready (RR) soybean crops where glyphosate and 2,4-D have frequently been applied, although there are no confirmed reports worldwide of resistance to glyphosate and 2,4-D in this species. Dose–response tests showed multiple-resistance to both active principles. The resistant population (R) had LD50 values of 1854.27 and 1577.18 g ae ha−1 (grams of acid equivalent per hectare), while the susceptible (S) population had LD50 values of 195.56 and 111.78 g ae ha−1 for glyphosate and 2,4-D, respectively. Low accumulations of shikimic acid (glyphosate) and ethylene (2,4-D) at different doses in the R population compared to the S population support the results observed in the dose–response curves. No significant differences in leaf retention were observed for glyphosate and 2,4-D in the R and S populations. However, the use of adjuvants increased the retention capacity of herbicides in both populations. Ten alternative herbicides with seven different action mechanisms (MOAs) were evaluated and the most effective active principles were dicamba, bromoxynil, atrazine, tembotrione, flazasulfuron, glufosinate, and paraquat. These findings are the first evidence of glyphosate and 2,4 D resistance in C. acanthoides

Prophylaxis of Experimental Endocarditis With Antiplatelet and Antithrombin Agents: A Role for Long-term Prevention of Infective Endocarditis in Humans?

Background. Infective endocarditis (IE) mostly occurs after spontaneous low-grade bacteremia. Thus, IE cannot be prevented by circumstantial antibiotic prophylaxis. Platelet activation following bacterial-fibrinogen interaction or thrombin-mediated fibrinogen-fibrin polymerization is a critical step in vegetation formation. We tested the efficacy of antiplatelet and antithrombin to prevent experimental IE. Methods. A rat model of experimental IE following prolonged low-grade bacteremia mimicking smoldering bacteremia in humans was used. Prophylaxis with antiplatelets (aspirin, ticlopidine [alone or in combination], eptifibatide, or abciximab) or anticoagulants (antithrombin dabigatran etexilate or anti-vitamin K acenocoumarol) was started 2 days before inoculation with Streptococcus gordonii or Staphylococcus aureus. Valve infection was assessed 24 hours later. Results. Aspirin plus ticlopidine, as well as abciximab, protected 45%-88% of animals against S. gordonii and S. aureus IE (P < .05). Dabigatran etexilate protected 75% of rats against IE due to S. aureus (P < .005) but failed to protect against S. gordonii (<30% protection). Acenocoumarol was ineffective. Conclusions. Antiplatelet and direct antithrombin agents may be useful in the prophylaxis of IE in humans. In particular, the potential dual benefit of dabigatran etexilate might be reconsidered for patients with prosthetic valves, who require life-long anticoagulation and in whom S. aureus IE is associated with high mortalit

Design and evaluation of a three-dimensional virtual laboratory on vector operations

[EN] In Physics, many quantities are vectors, and their use requires typical operations such as addition, subtraction, scalar multiplication, scalar product (dot product), vector product (cross product), and scalar triple product. This is a very basic topic in all General Physics courses for Engineering degrees. However, we have detected that some students lack a deep understanding of vector operations and their properties. In this study, we present a virtual laboratory (developed using the tool Easy Java Simulations) for the study and understanding of these topics. The user can introduce the components of the input vectors and gets a three-dimensional representation, which can be scaled and rotated for better visualization. Any of the aforementioned operations can be selected, and the result is shown both numerically and graphically. The user can also modify any represented vector. In this way, the virtual lab provides a real-time visualization of how the change affects the result. The possibility of limiting the changes to either magnitude or direction is also included. The efficiency of the virtual laboratory has been tested analyzing the results obtained in two groups of students (virtual laboratory vs traditional resources). A satisfaction survey has been also carried out.Universitat Politecnica de Valencia, Grant/Award Number: PIME B24Salinas Marín, I.; Gimenez Valentin, MH.; Cuenca Gotor, VP.; Seiz Ortiz, R.; Monsoriu Serra, JA. (2019). Design and evaluation of a three-dimensional virtual laboratory on vector operations. Computer Applications in Engineering Education. 27(3):690-697. https://doi.org/10.1002/cae.22108S690697273Vidaurre, A., Riera, J., Giménez, M. H., & Monsoriu, J. A. (2002). Contribution of digital simulation in visualizing physics processes. Computer Applications in Engineering Education, 10(1), 45-49. doi:10.1002/cae.10016Depcik, C., & Assanis, D. N. (2005). Graphical user interfaces in an engineering educational environment. Computer Applications in Engineering Education, 13(1), 48-59. doi:10.1002/cae.20029Jimoyiannis, A., & Komis, V. (2001). Computer simulations in physics teaching and learning: a case study on students’ understanding of trajectory motion. Computers & Education, 36(2), 183-204. doi:10.1016/s0360-1315(00)00059-2Esquembre, F. (2002). Computers in physics education. Computer Physics Communications, 147(1-2), 13-18. doi:10.1016/s0010-4655(02)00197-2Steinberg, R. N. (2000). Computers in teaching science: To simulate or not to simulate? American Journal of Physics, 68(S1), S37-S41. doi:10.1119/1.19517GiménezMH SalinasI andMonsoriuJA Visualizador de operaciones con vectores (español/valencià/english) 2017.http://hdl.handle.net/10251/84650Accessed February 1 2019.TiplerPAandMoscaG Physics for Scientists and Engineers. New York NY: W.H. Freeman Cop 2008.NaveR HyperPhysics 2016.http://hyperphysics.phy‐astr.gsu.edu/hbase/hph.htmlAccessed February 1 2019.Esquembre, F. (2004). Easy Java Simulations: a software tool to create scientific simulations in Java. Computer Physics Communications, 156(2), 199-204. doi:10.1016/s0010-4655(03)00440-5Complements of Physics course description (2017).http://www.upv.es/titulaciones/GIM/menu_1015238i.htmlAccessed February 1 2019.Basic Physics for Engineering course description (2017).http://www.upv.es/titulaciones/GIEL/menu_1014686i.htmlAccessed February 1 2019