Se analizó la composición vertical la entomofauna en tres zonas del campus de la Universidad Nacional de Colombia en Bogotá entre los años 2018 y 2020 con el fin de dar a conocer especialmente a la ...comunidad en general, de la riqueza faunística en este relicto de zonas verdes dentro del paisaje urbano. Para la recolección de los especímenes, se realizaron muestreos estratificados en zonas con diferentes coberturas vegetales en el campus. La entomofauna recolectada se determinó a nivel de familia, para la cual se establecieron los valores de diversidad de Brillouin (B), dominancia (D) y equitatividad de Simpson (1-D). Se evaluó la eficiencia de los muestreos por medio del estimador Chao-1, se establecieron los modelos de abundancia de los sitios de muestreo para conocer su relación con los valores de diversidad y se determinó el nivel trófico de cada uno de los grupos recolectados. Los resultados muestran que la entomofauna de la Ciudad Universitaria está caracterizada por los bajos valores de diversidad, mayores valores de riqueza y abundancia en los estratos herbáceos y por el predominio de grupos de hábitos fitófagos y polífagos.
Context. It is debated whether the Milky Way bulge has characteristics more similar to those of a classical bulge than those of a pseudobulge. Detailed abundance studies of bulge stars are important ...when investigating the origin, history, and classification of the bulge. These studies provide constraints on the star-formation history, initial mass function, and differences between stellar populations. Not many similar studies have been completed because of the large distance and high variable visual extinction along the line-of-sight towards the bulge. Therefore, near-IR investigations can provide superior results. Aims. To investigate the origin of the bulge and study its chemical abundances determined from near-IR spectra for bulge giants that have already been investigated with optical spectra. The optical spectra also provide the stellar parameters that are very important to the present study. In particular, the important CNO elements are determined more accurately in the near-IR. Oxygen and other α elements are important for investigating the star-formation history. The C and N abundances are important for determining the evolutionary stage of the giants and the origin of C in the bulge. Methods. High-resolution, near-infrared spectra in the H band were recorded using the CRIRES spectrometer mounted on the Very Large Telescope. The CNO abundances are determined from the numerous molecular lines in the wavelength range observed. Abundances of the α elements Si, S, and Ti are also determined from the near-IR spectra. Results. The abundance ratios O/Fe, Si/Fe, and S/Fe are enhanced to metallicities of at least Fe/H = -0.3, after which they decline. This suggests that the Milky Way bulge experienced a rapid and early burst of star formation similar to that of a classical bulge. However, a similarity between the bulge trend and the trend of the local thick disk seems to be present. This similarity suggests that the bulge could have had a pseudobulge origin. The C and N abundances suggest that our giants are first-ascent red-giants or clump stars, and that the measured oxygen abundances are those with which the stars were born. Our C/Fe trend does not show any increase with Fe/H, which is expected if W-R stars contributed substantially to the C abundances. No “cosmic scatter” can be traced around our observed abundance trends: the measured scatter is expected, given the observational uncertainties.
Abstract
We study stellar models for Betelgeuse using the HR diagram and surface abundances as observational constraints. Previous studies on Betelgeuse have not systematically investigated the ...surface abundances, but we believe they can be impacted by, and thus be used as an observational constraint for various parameters such as initial mass, rotation, and overshoot scheme. We investigate stellar models with varying initial mass as they evolve past the main sequence, and we examine the red supergiant (RSG) properties in detail. For each mass, we vary the initial rotation up to ∼300 km s
−1
, and test two different overshoot parameters. Overall, the acceptable initial mass range is 12–25
M
⊙
, but for nonrotating models only, the range is decreased to 15–24
M
⊙
. Also for rotating models, we find that
v
/
v
K
= 0.3 is the upper limit for initial rotation, as more rapidly rotating models are unable to fit to Betelgeuse’s surface abundances as an RSG. In addition, we report two possibilities for the current stage of evolution, core helium burning or core carbon burning and beyond. We find that certain 17
M
⊙
models could fit both stages. Finally, we discuss the implications of our results in the context of merger scenarios which have been suggested as a mechanism to attain the observed surface velocity of Betelgeuse.
The objective of this research was to identify the families of mites associated with wild blackberry (Rubus fruticosus L.), know its space distribution and population fluctuation in Telcruz is ...located in the Municipality of Cuautitlán de García Barragán in the State of Jalsico, Mexico. A total of 1,836 mites were collected, corresponding to three orders and 14 families, the most abundant were Tetranychidae, Diptilomiopidae, Eriophyidae and Phytoseiidae, which contributed 73,6 % of the total collected mites. The Parasitidae, Bdellidae, Cunaxidae, Iolinidae, Oribatidae families are new records of association with wild blackberry plants in
Mexico. Most of the families were distributed in the middle stratum of the plants. Population fluctuation increased from February, with the highest peak in April. It was observed that the number of predatory families increased as the number of phytophagous families increased. This is the first study where an inventory of the families of mites associated with wild blackberry plants is carried out and it serves as a precedent for future research on how to use more effective management strategies for this crop.
El objetivo de la investigación fue identificar las familias de ácaros asociados a zarzamora silvestre (Rubus fruticosus L.), conocer su distribución espacial y su fluctuación poblacional en la localidad de Telcruz, ubicada en el municipio de Cuautitlán de García Barragán en el estado de Jalisco, México. Se colectaron 1.836 ácaros correspondientes a tres órdenes y 14 familias, de las cuales las más abundantes son Tetranychidae, Diptilomiopidae, Eriophyidae y Phytoseiidae, que aportaron el 73,6% del total de los ácaros. Las familias Parasitidae, Bdellidae, Cunaxidae, Iolinidae, Oribatidae son nuevos registros de asociación a plantas de zarzamora silvestre en México. La mayor parte de las familias se distribuyeron en el estrato medio de las plantas. La fluctuación poblacional aumentó a partir de febrero, con el pico más alto en abril. Se observó que el número de familias depredadoras aumentó en la medida en que se incrementó el de familias fitófagas. Este es el primer estudio donde se realiza un inventario de las familias de ácaros asociados a plantas silvestres de zarzamora y que sirve como un antecedente para futuras investigaciones acerca de cómo emplear estrategias de manejo más efectivas en este cultivo
We calculate a new equation of state for baryons at sub-nuclear densities meant for the use in core-collapse simulations of massive stars. The abundances of various nuclei are obtained together with ...the thermodynamic quantities. The formulation is the nuclear statistical equilibrium description and the liquid drop approximation of nuclei. The model free energy to minimize is calculated by relativistic mean field theory for nucleons and the mass formula for nuclei with atomic number up to ~1000. We have also taken into account the pasta phase, thanks to which the transition to uniform nuclear matter in our equation of state (EOS) occurs in the conventional manner: nuclei are not dissociated into nucleons but survive right up to the transition to uniform nuclear matter. We find that the free energy and other thermodynamical quantities are not very different from those given in the H. Shen's EOS, one of the standard EOSs that adopt the single nucleus approximation. On the other hand, the average mass is systematically different, which may have an important ramification to the rates of electron captures and coherent neutrino scatterings on nuclei in supernova cores. It is also interesting that the root mean square of the mass number is not very different from the average mass number, since the former is important for the evaluation of coherent scattering rates on nuclei but has been unavailable so far. The EOS table is currently under construction, which will include the weak interaction rates.
The genus Streptomyces is the best-known source of therapeutic secondary metabolites, especially antibiotics with pharmaceutical applications. Here, we performed a comparative study based on the ...time-resolved metabolic disparity in S. coelicolor A3(2) subjected to fermentative cultivation in two different types of media (R2YE and RSM3) in order to investigate secondary metabolite production pathways. The relative abundance of secondary metabolites, such as prodiginines, indoles, germicidins, and selected diketopiperazines, was increased in S. coelicolor A3(2) cultivated in R2YE medium compared to that in RSM3 medium, variably at the late-log and stationary phases of fermentative growth. Correlation analysis indicated that "antibiotic prodiginines" contributed maximally to the absorption maxima (A530) of culture supernatants, indicating their optimal production at 96 hours in R2YE medium. A higher abundance of L-proline (48-72 hours) followed by prodiginines (96 hours) was evident, substantiating the intertwined links between precursor and activated prodiginines pathway. Similarly, the higher abundance of indoles was concurrent with tryptophan levels in the shikimate pathway, whereas diketopiperazines were synchronously abundant along with the levels of phenylalanine, leucine, and proline. Additionally, acetyl-CoA induced the acetate pathway, resulting in the production of germicidins. Thus, our results demonstrate that S. coelicolor A3(2) produces specific secondary metabolites by enhancing the dedicated metabolic pathway responsible for their production. In conclusion, our results from this study provide insight into the metabolic pathways of S. coelicolor A3(2), and can be applied to further optimize the production of prodiginines.
La comunidad de peces en la Laguna del Ostión es objeto de pesca, sin embargo, los estudios ecológicos sobre esta son escasos. Se analizó la variación espacial y temporal de su estructura ...comunitaria, así como de los parámetros fisicoquímicos de salinidad, temperatura, oxígeno disuelto, profundidad y transparencia de la laguna. Los peces fueron recolectados bimensualmente de marzo de 2007 a enero de 2008, en ocho estaciones de muestreo con una red de arrastre camaronera. Se evaluaron diferencias significativas espacio-temporales de diversidad, riqueza, equitatividad, densidad, biomasa y peso promedio, mediante análisis de varianza. Se realizó análisis de correspondencias canónicas (ACC) para determinar las asociaciones de peces y su correlación con los factores ambientales del sistema. Se recolectaron 737 individuos con peso total de 19 081.90 g. Se identificaron 19 familias, 23 géneros y 34 especies, 12 de las cuales fueron nuevos registros para la laguna. Cuatro especies fueron dominantes en el sistema. Los parámetros comunitarios mostraron relación con los gradientes ambientales y las temporadas climáticas. La diversidad fue más alta en mayo (H´ = 2.36) y enero (H´ = 2.48) y la densidad en julio (0.018 ind./m2). El ACC mostró que la composición y distribución espacio-temporal de la comunidad de peces estuvo condicionada por la salinidad, la temperatura, el oxígeno disuelto y la profundidad. El conocimiento de la estructura comunitaria, las funciones biológicas de los peces y su interacción con los factores ambientales de esta laguna es relevante, ya que no se han desarrollado estudios continuos en este sistema.
La taricaya (Podocnemis unifilis) y el teparo (Phrynops geoffroanus) representan especies con alto valor ambiental y económic; y para conocer el estado de sus poblaciones, se estimó el índice de ...abundancia (IA) a través de 20 transectos acuáticos de 10 km de recorrido en 3 sectores: Parque Nacional Alto Purús (PNAP), Reserva Comunal Purús (RCP) y la Zona de Amortiguamiento (territorio comunal adyacente a la RCP). Se obtuvieron 737 registros con 2335 individuos avistados para taricaya y sólo 17 registros con 25 individuos avistados para teparo. El IA de la taricaya para el RCP fue de 3,9 ind/km recorrido (EE = 0,6). Se pudo evidenciar un mayor IA en los subsectores dentro del PNAP y progresivamente menor IA en los sectores de la Zona de Amortiguamiento (ZA) de la RCP. Estos resultados valorizan la importancia de las áreas naturales protegidas (ANP) para mantener las poblaciones de especies como la taricaya; y representan el inicio de un monitoreo robusto para que en las siguientes temporadas y junto a otros indicadores económicos y sociales tener una visión general del estado de conservación de la especie en la RCP. Para el caso de la especie teparo, si bien es posible realizar cálculos del índice de abundancia, estos no tienen una interpretación biológica de la población de la especie en la RCP, y compete a la Jefatura de la RCP tomar las decisiones de ajuste en los métodos de levantamiento de información y/o diseño de muestreo de la evaluación de esta importante especie.
We use an analytic model to investigate the theoretical uncertainty on the thermal Sunyaev-Zel'dovich (SZ) power spectrum due to astrophysical uncertainties in the thermal structure of the ...intracluster medium. Our model accounts for star formation and energy feedback (from supernovae and active galactic nuclei) as well as radially dependent non-thermal pressure support due to random gas motions, the latter calibrated by recent hydrodynamical simulations. We compare the model against X-ray observations of low-redshift clusters, finding excellent agreement with observed pressure profiles. Varying the levels of feedback and non-thermal pressure support can significantly change both the amplitude and shape of the thermal SZ power spectrum. Increasing the feedback suppresses power at small angular scales, shifting the peak of the power spectrum to lower l. On the other hand, increasing the non-thermal pressure support has the opposite effect, significantly reducing power at large angular scales. In general, including non-thermal pressure at the level measured in simulations has a large effect on the power spectrum, reducing the amplitude by 50% at angular scales of a few arcminutes compared to a model without a non-thermal component. Our results demonstrate that measurements of the shape of the power spectrum can reveal useful information on important physical processes in groups and clusters, especially at high redshift where there exists little observational data. Comparing with the recent South Pole Telescope measurements of the small-scale cosmic microwave background power spectrum, we find our model reduces the tension between the values of Delta *s8 measured from the SZ power spectrum and from cluster abundances.
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