Modeling L- and X-band backscattering of wheat and tests over fields of Pampas

A discrete scattering model and a detailed set of ground measurements are used to simulate the backscattering coefficients of wheat fields during the whole growth cycle. Simulations are carried out at L- and X-band, and at HH, VV, and HV polarizations. Wheat fields are located in Pampas (Argentina), and are characterized by low values of plant density. Simulations show that the backscattering coefficient is driven by variations of soil moisture at L-band, particularly for HH polarization, with low vegetation effects. Conversely, the attenuation of vegetation is dominant in producing variations of backscattering coefficients at X-band, particularly for VV polarization. Simulations are compared against experimental data collected over the same Pampas region, using airborne SARAT SAR at L-band and COSMO-SKYMED at X-band. Assuming a surface height standard deviation in a 0.4–0.7 cm range, the simulations generally agree with experimental data, with an RMSE lower than about 2 dB at L-band and X-band, except a limited number of cases. Discrepancies observed in specific conditions are discussed. Overall, the results indicate that a joint use of L- and X-band has a good potential to monitor both soil moisture and vegetation growth

Association between agility and speed with changes of direction in young players

Identificar factores asociados al máximo rendimiento en el fútbol posibilitará mejorar el proceso de planificación deportiva en etapas tempranas. Este estudio tuvo como objetivo determinar la asociación entre la agilidad y la velocidad con cambios de dirección (VCD) en jóvenes futbolistas (JF). Participaron voluntariamente dieciocho hombres entre los 10 y 13 años los cuales aplicaron el test de 20 metros con cambios de dirección (T20CD) y el test de agilidad Illinois (TAI). El análisis estadístico se realizó en el IBM SPSS V.22 en el cual se fijó para la significancia un p0,05) y no normal en TAI (p<0,05), el coeficiente correlacional de Spearman (r = 0,06; p = 0,8) evidenció una relación poco significativa (p<0,05). Por lo tanto se concluye que no existe asociación significativa entre la agilidad y la VCD en JF

Characterization of the HD 108236 system with CHEOPS and TESS Confirmation of a fifth transiting planet

Context. The HD 108236 system was first announced with the detection of four small planets based on TESS data. Shortly after, the transit of an additional planet with a period of 29.54 d was serendipitously detected by CHEOPS. In this way, HD 108236 (V = 9.2) became one of the brightest stars known to host five small transiting planets (Rp < 3 R⊕). Aims. We characterize the planetary system by using all the data available from CHEOPS and TESS space missions. We use the flexible pointing capabilities of CHEOPS to follow up the transits of all the planets in the system, including the fifth transiting body. Methods. After updating the host star parameters by using the results from Gaia eDR3, we analyzed 16 and 43 transits observed by CHEOPS and TESS, respectively, to derive the planets’ physical and orbital parameters. We carried out a timing analysis of the transits of each of the planets of HD 108236 to search for the presence of transit timing variations. Results. We derived improved values for the radius and mass of the host star (R★ = 0.876 ± 0.007 R0 and M★ = 0.867-0.046+0.047M⊙). We confirm the presence of the fifth transiting planet f in a 29.54 d orbit. Thus, the HD 108236 system consists of five planets of Rb = 1.587±0.028, Rc = 2.122±0.025, Rd = 2.629 ± 0.031, Re = 3.008 ± 0.032, and Rf = 1.89 ± 0.04 [R⊕]. We refine the transit ephemeris for each planet and find no significant transit timing variations for planets c, d, and e. For planets b and f, instead, we measure significant deviations on their transit times (up to 22 and 28 min, respectively) with a non-negligible dispersion of 9.6 and 12.6 min in their time residuals. Conclusions. We confirm the presence of planet f and find no significant evidence for a potential transiting planet in a 10.9 d orbital period, as previously suggested. Further monitoring of the transits, particularly for planets b and f, would confirm the presence of the observed transit time variations. HD 108236 thus becomes a key multi-planetary system for the study of formation and evolution processes. The reported precise results on the planetary radii – together with a profuse RV monitoring – will allow for an accurate characterization of the internal structure of these planets

La literatura, una herramienta para la física

In this paper we show a way of using literature as a didactic resource in the physics teaching, particularly in teaching of some topics of kinematics. A strategy is designed in which, through science fiction literature, it is possible high school students take interest in scientific subjects and at the same time to feel identified with characters of the story, because they were also integral humans. We based on authors like Julio Verne, Iván Obregón and others, have produced possible literary material to be implemented in science teaching.En este artículo mostramos una manera de utilizar la literatura como recurso didáctico en la enseñanza de la física, en particular en la enseñanza de algunos temas de cinemática. Se diseña una estrategia en la que por medio de la literatura se logra que los estudiantes de media vocacional se interesen en temas científicos y a la vez se sientan identificados con los personajes de la historia, debido a que ellos también fueron seres humanos íntegros. Nos basamos en autores como Julio Verne, Iván Obregón y otros, han producido material literario posible de ser implementado en la enseñanza de las ciencias

Exploring Opportunities for Food Service Marketing in Condominiums: A Conjoint Analysis Approach

Davao City, one of the fastest growing economies in the Philippines, has seen an increase in the development and demand for condominiums in recent years. Current trends in other major cities worldwide include the integration of food service and food distribution channels within condominium projects. This study explores the potential for food marketing within condominiums using conjoint analysis, cluster analysis, and logistic regression. The study gathered 200 responses for a survey encompassing socio-demographic profiles, consumer preferences, as well as 18 plan cards (unique condominium attribute combinations) that respondents were tasked to rate from 1 to 10. Results show that most potential condominium buyers are career-driven people within the age range of 20–40 who have relatively high monthly incomes. Of the 200 respondents, 90.50% preferred condominiums with in-house food services. The conjoint process shows that there is a positive relationship between a condominium’s marketability and presence of in-house food services (9.344%). However, it should be noted that primary attributes like furnishing level score higher importance values (26.035%). Cluster analysis reveals two distinct consumer groups: the “Unit-Focused” cluster that focuses largely on unit-specific attributes and the “Meticulous” cluster that pay relatively more attention to secondary attributes like integrated food services. A binary Logit analysis shows that respondents who are married, have relatively large households, and eat out because of better food quality are more likely to be “Meticulous” buyers, and these buyers pay more attention to a condominium’s in-house food channels and other amenities. Condominium developers and the food service sector may capitalize on this opportunity, but food-integrated condominium offerings should be tailored to married food-cautious buyers and those that live highly urban lifestyles

El agronegocio del cultivo de tartago em el mundo.

bitstream/CNPA/18351/1/CIRTEC101.pd

Pobreza en México: Factor de vulnerabilidad para enfrentar los efectos del cambio climático

Poverty levels that occur in Mexico are a problem that is becoming increasingly acute in the different territorial levels. The shortage of financial resources for access to goods, services and cultural factor, constitute the main constraint to access an adequate standard of living, which provide comprehensive security conditions in the population. This condition is a determining factor in the inability to deal with the various hydrometeorological and geological phenomena that occur as part of climatic changes in the Earth system, a situation that undermines the population living in poverty to suffer the ravages in all dimensions: physical, economic and social. Climate change, seen as a process that has been more acute due to human activity in the different territorial levels weakens the ability of response and prevention of disasters caused by it, not just vulnerable groups, rather, intervention government agencies, leading to moments of political, economic and social instability in the different action levels (local, state and national).Rev. iberoam. bioecon. cambio clim. Vol. 1 num 2, 2015, pág. 1-19Los niveles de pobreza que se presentan en México constituyen una problemática que se agudiza cada vez más en las diferentes escalas territoriales. La escasez de recursos económicos para el acceso a bienes, servicios y el factor cultural, constituyen la principal restricción para acceder a un nivel de vida adecuado, el cual proporcione condiciones integrales de seguridad en la población. Dicha condición resulta un factor determinante en la imposibilidad para hacer frente a los distintos fenómenos hidrometeorológicos y geológicos que se presentan como parte de las alteraciones climáticas en el sistema terrestre, situación que vulnera a la población en condición de pobreza a padecer los estragos en todas sus dimensiones: física, económica y social. El cambio climático, visto como un proceso que ha venido agudizándose debido a la actividad antrópica en las diferentes escalas territoriales, debilita la capacidad de respuesta y prevención de desastres ocasionados por éste, no sólo en los grupos vulnerables, más bien, en la intervención de las instancias gubernamentales, lo que conlleva a momentos de inestabilidad política, económica y social en los diferentes niveles de actuación (local, estatal y nacional).Rev. iberoam. bioecon. cambio clim. Vol. 1 num 2, 2015, pág. 1-1

ES cells-derived ectomesenchymal cells for tooth engineering.

Recent progresses in stem cell biology and tissue engineering allow considering the possible development of new therapies for compensating the dental tissue losses associated with traumas, pathologies or ageing. The possibility of generating a tooth by mimicking development through reassociations between dental epithelial cells and ectomesenchymal cells derived from the neural crest (NC) has been demonstrated in the mouse. In the search of cell sources to be used for a human transfer, pluripotent stem cells could represent a good alternative. Our study thus focuses on obtaining, ectomesenchymal cells from pluripotent ES cells, capable of promoting tooth histomorphogenesis, when reassociated with a competent dental epithelium. To this end, two ES differentiation protocols, using cyclopamine or a combination of FGF2 and BMP4, have been developed and tested for their capacity to generate such cells. The differentiated ES cells were characterized by quantitative RT-PCR. Both protocols led the cells to acquire in 10 days a mesenchymal-like cell morphology. Rapidly after induction, the cells loose their expression of pluripotent genes while sequentially activating typical NC specifiers. However, the kinetics of gene activation differed between the 2 protocols. Interestingly, Twist, a gene whose expression in the NC is associated with a commitment towards an ectomesenchymal fate, is only activated under the influence of FGF2 and BMP4. Reassociation experiments with a competent epithelium will allow testing the odontogenic potential of the differentiated ES cells. These experiments performed in the mouse system should allow defining a strategy for obtaining odontogenic competent human cells. Les progrès en matière de biologie de cellules souches et d’ingénierie tissulaire permettent d’envisager le développement de nouvelles thérapies pour pallier les pertes de tissus dentaires consécutives à des traumatismes, des situations pathologiques ou au vieillissement. La possibilité de générer une dent en mimant le développement, par réassociations entre cellules dentaires épithéliales et mésenchymateuses dérivées des crêtes neurales (CN), a été démontrée chez la souris. Dans la recherche de ressources cellulaires utilisables pour un transfert chez l’homme, les cellules souches pluripotentes pourraient constituer une alternative. Notre but est d’obtenir à partir de ces dernières, des cellules ectomésenchymateuses capables d’interagir avec un épithélium dentaire pour promouvoir l’histomorphogenèse d’une dent. Pour cela, deux protocoles de différenciation de cellules ES, utilisant la cyclopamine ou une combinaison de FGF2/BMP4, ont été mis au point. Les cellules induites ont été caractérisées par PCR quantitative. Les deux protocoles de différenciation amènent les cellules à acquérir en 10 jours, une morphologie de type mésenchymateux. Après induction, l’expression des gènes de pluripotence chute de façon drastique alors que celle des gènes spécificateurs de CN est activée. Toutefois, la cinétique varie selon le protocole. Le gène Twist, dont l’expression dans les CN est associée à un engagement vers l’ectomésenchyme, n’est activé significativement que sous l’action de FGF2/BMP4. Des expériences de réassociations avec un épithélium dentaire sont en cours pour évaluer le potentiel odontogène des cellules ES différenciées. A terme, ces approches menées chez la souris devraient permettre de définir une stratégie pour l’obtention de cellules compétentes humaines.Recent progresses in stem cell biology and tissue engineering allow considering the possible development of new therapies for compensating the dental tissue losses associated with traumas, pathologies or ageing. The possibility of generating a tooth by mimicking development through reassociations between dental epithelial cells and ectomesenchymal cells derived from the neural crest (NC) has been demonstrated in the mouse. In the search of cell sources to be used for a human transfer, pluripotent stem cells could represent a good alternative. Our study thus focuses on obtaining, ectomesenchymal cells from pluripotent ES cells, capable of promoting tooth histomorphogenesis, when reassociated with a competent dental epithelium. To this end, two ES differentiation protocols, using cyclopamine or a combination of FGF2 and BMP4, have been developed and tested for their capacity to generate such cells. The differentiated ES cells were characterized by quantitative RT-PCR. Both protocols led the cells to acquire in 10 days a mesenchymal-like cell morphology. Rapidly after induction, the cells loose their expression of pluripotent genes while sequentially activating typical NC specifiers. However, the kinetics of gene activation differed between the 2 protocols. Interestingly, Twist, a gene whose expression in the NC is associated with a commitment towards an ectomesenchymal fate, is only activated under the influence of FGF2 and BMP4. Reassociation experiments with a competent epithelium will allow testing the odontogenic potential of the differentiated ES cells. These experiments performed in the mouse system should allow defining a strategy for obtaining odontogenic competent human cells. Les progrès en matière de biologie de cellules souches et d’ingénierie tissulaire permettent d’envisager le développement de nouvelles thérapies pour pallier les pertes de tissus dentaires consécutives à des traumatismes, des situations pathologiques ou au vieillissement. La possibilité de générer une dent en mimant le développement, par réassociations entre cellules dentaires épithéliales et mésenchymateuses dérivées des crêtes neurales (CN), a été démontrée chez la souris. Dans la recherche de ressources cellulaires utilisables pour un transfert chez l’homme, les cellules souches pluripotentes pourraient constituer une alternative. Notre but est d’obtenir à partir de ces dernières, des cellules ectomésenchymateuses capables d’interagir avec un épithélium dentaire pour promouvoir l’histomorphogenèse d’une dent. Pour cela, deux protocoles de différenciation de cellules ES, utilisant la cyclopamine ou une combinaison de FGF2/BMP4, ont été mis au point. Les cellules induites ont été caractérisées par PCR quantitative. Les deux protocoles de différenciation amènent les cellules à acquérir en 10 jours, une morphologie de type mésenchymateux. Après induction, l’expression des gènes de pluripotence chute de façon drastique alors que celle des gènes spécificateurs de CN est activée. Toutefois, la cinétique varie selon le protocole. Le gène Twist, dont l’expression dans les CN est associée à un engagement vers l’ectomésenchyme, n’est activé significativement que sous l’action de FGF2/BMP4. Des expériences de réassociations avec un épithélium dentaire sont en cours pour évaluer le potentiel odontogène des cellules ES différenciées. A terme, ces approches menées chez la souris devraient permettre de définir une stratégie pour l’obtention de cellules compétentes humaines