Kinematics of gas and stars in circumnuclear star-forming regions of early type spirals

(Abbr.) We present high resolution (R~20000) spectra in the blue and the far red of cicumnuclear star-forming regions (CNSFRs) in three early type spirals (NGC3351, NGC2903 and NGC3310) which have allowed the study of the kinematics of stars and ionized gas in these structures and, for the first time, the derivation of their dynamical masses for the first two. In some cases these regions, about 100 to 150 pc in size, are seen to be composed of several individual star clusters with sizes between 1.5 and 4.9 pc estimated from Hubble Space Telescope (HST) images. The stellar dispersions have been obtained from the Calcium triplet (CaT) lines at $\lambda\lambda$ 8494,8542,8662 \AA, while the gas velocity dispersions have been measured by Gaussian fits to the H$\beta$ and [OIII] $\lambda\lambda$ 5007 \AA lines on the high dispersion spectra. Values of the stellar velocity dispersions are between 30 and 68 km/s. We apply the virial theorem to estimate dynamical masses of the clusters, assuming that systems are gravitationally bounded and spherically symmetric, and using previously measured sizes. The measured values of the stellar velocity dispersions yield dynamical masses of the order of 10$^7$ to 10$^8$ solar masses for the whole CNSFRs. Stellar and gas velocity dispersions are found to differ by about 20 to 30 km/s with the H$\beta$ emission lines being narrower than both the stellar lines and the [OIII] $\lambda\lambda$ 5007 \AA lines. The twice ionized oxygen, on the other hand, shows velocity dispersions comparable to those shown by stars, in some cases, even larger. We have found indications of the presence of two different kinematical components in the ionized gas of the regions...Comment: 4 pages, proceeding of the meeting "Young massive star clusters - Initial conditions and environments", Granada, Spain, 200

A semiautomatic methodology to detect fire scars in shrubs and evergreen forests with Landsat MSS time series.

This paper presents a semi-automatic methodology for fire scars mapping from a long time series of remote sensing data. Approximately, a hundred MSS images from different Landsat satellites were employed over an area of 32 100 km2 in the north-east of the Iberian Peninsula. The analysed period was from 1975 to 1993. Results are a map series of fire history and frequencies. Omission errors are 23% for burned areas greater than 200 ha while commission errors are 8% for areas greater than 50 ha. Subsequent work based on the resultant fire scars will also help in describing fire regime and in monitoring post-fire regeneration dynamics.Peer Reviewe

Watershed level analysis of sediment filling in a Mexican highland reservoir

The Upper Lerma River Basin (ULRB) in Mexico, with a watershed area of 2118 km2, is strongly affected by urbanization and deforestation. More than 1.5 million people and more than 2000 industries are located within it (INEGI, 2000). Furthermore, the basin topography is abrupt with levels ranging from 2560 to 4570 m.a.s.l. and its precipitation varies from 700 mm in the lower basin to 1200 mm at higher levels. The erosion produced by climactic and anthropic effects is concentrated in the José Antonio Alzate Reservoir, which is located at the basin outlet and captures all the waters of the ULRB. The basin, which had an initial capacity of 45 hm3, has lost much of its capacity in only 42 years as is demonstrated here. Presented in this paper are the results from an erosion model using the RUSLE (Revised Universal Soil Loss Equation) methodology, which allows for the identification of critical areas. The resulting model is capable of explaining the high rate of sediment contribution. With the intention of validating the model, a bathymetric study of the reservoir was performed. .Actual bottom reservoir levels were compared with the levels before dam construction. This process was made with a GIS using a re-sampling process. The results show that reservoir storage capacity has been reduced by 21 hm3 which makes difficult the irrigation and flood control functions of the reservoir. Selective removal of sediments will lead to benefits in pollutant removal in the reservoir and improved capacity for downstream irrigation supply and flood control.La cuenca Alta del río Lerma (CARL) en el Estado de México con una extensión de 2118 km2, se encuentra fuertemente afectada por la urbanización y la deforestación. En efecto, allí se asientan más de 1.5 millones de habitantes y más de 2000 industrias (INEGI, 2000). Adicionalmente la topografía de la cuenca es bastante abrupta con elevaciones desde 4570 m.s.n.m. hasta 2560 m.s.n.m. y su régimen pluvial varía de promedios anuales en las zonas altas de 1200 mm a 700 mm en las zonas bajas. La erosión producida por efectos climáticos y antrópicos se refleja en el embalse José Antonio Alzate el primero sobre el río Lerma y que capta todas las aguas de la CARL. El embalse con un capacidad de almacenamiento al construirse de 45 hm3 ha perdido mucha capacidad en tan solo 42 años de vida como se demuestra en este trabajo. Se presentan los resultados de un modelo de erosión de la cuenca utilizando el método RUSLE, lo cual permitió identificar las áreas críticas. El modelo resultante es capaz de explicar la alta tasa de aporte de sedimentos. Con el fin de validar el modelo se efectuó un levantamiento batimétrico del embalse. La topografía actual se comparó con la existente antes de la construcción de la cortina. Este proceso de acoplamiento fue realizado en un SIG con base en un proceso de remuestreo. Los resultados muestran una reducción en la capacidad del embalse de 21 hm3 lo cual le impide cumplir adecuadamente con sus funciones de irrigación y control de inundaciones. Una remoción selectiva de sedimentos es propuesta en este artículo procurando incrementar la eficiencia de remoción de contaminantes del embalse y la capacidad para el control de inundaciones y suministro de agua para irrigación

Fluorescent Excitation of Balmer Lines in Gaseous Nebulae: Case D

Nonionizing stellar continua are a potential source of photons for continuum pumping in the hydrogen Lyman transitions. In the environments where these transitions are optically thick, de-excitation occurs through higher series lines. As a result, the emitted flux in the affected lines has a fluorescent contribution in addition to the usual recombination one; in particular, Balmer emissivities are systematically enhanced above case B predictions. The effectiveness of such a mechanism in H II regions and the adequacy of photoionization models as a tool to study it are the two main focuses of this work. We find that photoionization models of H II regions illuminated by low-resolution (λ/δλ ≲ 1000) population synthesis models significantly overpredict the fluorescent contribution to the Balmer lines; the bias has typical values of the order of a few hundredths of a dex, with the exact figure depending on the parameters of the specific model and the simulated aperture. Conversely, photoionization models in which the nonionizing part of the continuum is omitted or is not transferred significantly underpredict the fluorescent contribution to the Balmer lines, producing a bias of similar amplitude in the opposite direction. Realistic estimations of the actual fluorescent fraction of the Balmer intensity require photoionization models in which the relevant portion of the stellar continuum is adequately represented, that is, its resolution is high in the region of the Lyman lines. In this paper, we carry out such an estimation and discuss the variations to be expected as the simulated observational setup and the stellar population\u27s parameters are varied. In all the cases explored, we find that fluorescent excitation provides a significant contribution to the total Balmer emissivity. We also show that differential fluorescent enhancement may produce line-of-sight differences in the Balmer decrement, mimicking interstellar extinction. Fluorescent excitation emerges from our study as a small but important mechanism for the enhancement of Balmer lines. As such, we recommend to take it into account in the abundance analysis of photoionized regions, particularly in the case of high-precision applications such as the determination of primordial helium

THE STRUCTURAL CHARACTERIZATION OF A NEW FORM OF CLENBUTEROL, A WELL KNOWN DECONGESTANT AND BRONCHODILATOR ALSO USED AS A PERFORMANCE-ENHANCING DRUG

ABSTRACT Clenbuterol hydrochloride is an active pharmaceutical ingredient usually prescribed for the treatment of respiratory diseases due to its activity as a decongestant and bronchodilator. It has also been used as a performance-enhancing drug. In the PDF-4/Organics 2012 database there are six entries related to this compound: three for its hydrochloride phase calculated using single crystal data, two for a MeOH and a DMSO solvate of two Cu-clenbuterol complexes, and one experimental unindexed pattern. In this contribution the powder diffraction pattern and the crystal structure, determined using single crystal X-ray diffraction techniques of Clenbuterol hemihydrate, C 12 H 18 Cl 2 N 2 O·0.5H 2 O, an unreported phase, is presented

Micropropagación y conservación de germoplasma de Ficus americana Aubl. y F. obtusifolia Kunth de Lambayeque (Perú)

Ficus americana and F. obtusifolia are among the most important tree species in Seasonally Dry Tropical Forests (SDTF) due to their evergreen condition and high levels of biomass. However, the SDTF of Lambayeque and northern Peru is greatly diminishing due to the advance of migratory agriculture, illegal mining, and deforestation. The objective of this work was to study the taxonomic aspects of both species, as well as seed germination, micropropagation, and in vitro germplasm conservation. Seed germination was 100% for both species up to three months after collection. As for micropropagation, rooting, and germplasm conservation, the Piper culture medium was effective, as it was constituted by MS mineral salts with 0.02 mg.L-1 IAA and 0.02 mg.L-1 GA3. In vitro germplasm conservation lasted more than 24 months for both species. Acclimatization under greenhouse conditions reached 50% survival for both species.Ficus americana y F. obtusifolia, se encuentran entre las especies arbóreas más importantes de los Bosques Tropicales Estacionalmente Secos (BTES) por su condición de siempre verdes y sus altos niveles de biomasa. Sin embargo, el BTES de Lambayeque y el norte de Perú está disminuyendo enormemente debido al avance de la agricultura migratoria, la minería ilegal y la deforestación. El objetivo de este trabajo fue estudiar los aspectos taxonómicos de ambas especies, así como la germinación de semillas, la micropropagación y la conservación de germoplasma in vitro. La germinación de semillas fue de 100 % en ambas especies hasta tres meses después de la recolección. Respecto a la micropropagación, el enraizamiento y la conservación de germoplasma, el medio de cultivo de Piper resultó efectivo, el cual está conformado por sales minerales MS con IAA 0.02 mg.L-1 y GA3 0.02 mg.L-1. La conservación in vitro de germoplasma duró más de 24 meses en ambas especies. La aclimatación en condiciones de invernadero alcanzó 50 % de supervivencia en ambas especies

Fibrohistiocitoma maligno óseo tras degeneración de enfermedad de Paget Caso clínico y revisión de la literatura

El fibrohistiocitoma maligno óseo es un tumor de estirpe mesenquimal poco frecuente, pero de alta agresividad. Se suele presentar de forma primaria, aunque a veces lo hace sobre lesiones previas en el hueso. Puede ser difícil de diferenciar histológicamente de otros tumores, pero es una entidad propia desde el punto de vista anatomopatológico. Presentamos un paciente con enfermedad de Paget que desarrolló un fibrohistiocitoma maligno óseo en el fémur sobre el hueso pagético. Fue tratado mediante desarticulación de cadera. No se usó quimioterapia como tratamiento coadyuvante debido a su avanzada edad y situación basal. A los 18 meses se encuentra asintomático y sin signos de recurrencia. Se hace una revisión de la literatura acerca de este tumor.Malignant fibrous histiocytoma of bone is a rare but highly agressive mesenchimal tumor. It usually arises as a primary tumor but sometimes it can be associated with pre-existing bone abnormalities. Histologically it can be missdiagnosed with other tumors. We report a case of malignant fibrous histiocytoma of bone in the femur in a patient with Paget's disease treated by hip desarticulation. We didn't use chemotherapy because his elderly status. At 18 months follow up, the patient is symptom-free and neither local recurrence nor metastasis have been found. A review of the literature has been carried out

The CaT strength in Seyfert nuclei revisited: analyzing young stars and non-stellar light contributions to the spectra

In a former paper (Garcia-Rissmann et al. 2005; hereafter Paper I), we have presented spectra of 64 active, 9 normal and 5 Starburst galaxies in the region around the near-IR Calcium triplet absorption lines and the [SIII]9069 line. In the present paper we analyze the CaT strength (WCaT), and kinematical products derived in that study, namely stellar and ionized gas velocity dispersions. Our main results may be summarized as follows: (1) Seyfert 2s show no sign of dilution in WCaT with respect to the values spanned by normal galaxies, even when optical absorption lines such as the CaII K band at 3933 A are much weaker than in old, bulge-like stellar populations. (2) The location of Seyfert 2s in the WCaT-WCaK plane is consistent with evolutionary synthesis models. The implication is that the source responsible for the dilution of optical lines in these AGN is a young stellar population, rather than an AGN featureless continuum, confirming the conclusion of the pioneer study of Terlevich, Diaz & Terlevich. (3) In Seyfert 1s, both W[SIII] and WCaT tend to be diluted due to the presence of a non-stellar component, in agreement with the unification paradigm. (4) A comparison of stellar and gas velocity dispersions confirms the existence of a correlation between the typical velocities of stars and clouds of the Narrow Line Region. The strength and scatter around this correlation are similar to those previously obtained from the [OIII]5007 line width.Comment: 14 pages, 15 figures. Paper accepted for publication in MNRA