The embedded cluster or association Trumpler 37 in IC1396: a search for evolutionary constraints

It is currently widely accepted that open star clusters and stellar associations result from the evolution of embedded star clusters. Parameters such star formation efficiency, time-scale of gas removal and velocity dispersion can be determinants of their future as bound or unbound systems. Finding objects at an intermediate evolution state can provide constraints to model the embedded cluster evolution. In the HII region IC1396, Trumpler 37 is an extended young cluster that presents characteristics of an association. We employed the Two Micron All Sky Survey (2MASS) photometry to analysing its structure and stellar content, and determining its astrophysical parameters. We also analysed 11 bright-rimmed clouds in IC1396 in order to search for young infrared star clusters, and the background open star cluster Teutsch 74, to verify whether it has any contribution to the observed stellar density profile of Trumpler 37. The derived parameters and comparison with template objects from other studies lead us to conclude that Trumpler 37, rather than as a star cluster, will probably emerge from its molecular cloud as an OB association.Comment: 13 pages, 10 figures, 6 table

Uniform detection of the pre-main sequence population in the 5 embedded clusters related to the H\,II region NGC\,2174 (Sh2-252)

We investigate 5 embedded clusters (ECs) and the extended stellar group itself of the prominent H\,II region NGC\,2174 (Sh2-252), which presents scarce and heterogeneous information, coming from the optical and infrared. Considering the discrepant values of distance and age, the clusters and the H\,II region appear to be physically unrelated. The analysis is based on field-star decontaminated 2MASS photometry, which allows sampling the pre-main sequence (PMS). We find that Sh2-252A, C, E, NGC\,2175s, and Teu\,136 are small ECs (radius within $1.0 - 2.3$\,pc) characterised by a similar age ($\sim5$\,Myr), reddening (\aV\sim1), distance from the Sun (\ds\sim1.4\,kpc), and low mass (60-200\,\ms). This age is consistent with the H\,II region, the presence of O and B stars still in the MS, and the dominance (\ga95% in number) of PMS stars in colour-magnitude diagrams (CMDs). NGC\,2175 is not a star cluster, but an extended stellar group that encompasses the ECs Sh2-252\,A and C. It contains $\sim36$ of the member stars (essentially PMS) in the area, with the remaining belonging to the 2 ECs. CMDs of the overall star-forming region and the ECs provide \ds=1.4\pm0.4\,kpc for the NGC\,2174 complex, consistent with the value estimated for the physically-related association Gem\,OB1. Our uniform approach shows that NGC\,2174 and its related ECs (except, perhaps, for Teu\,136) are part of a single star-forming complex. CMD similarities among the ECs and the overall region suggest a coeval (to within $\pm5$\,Myr) star-forming event extending for several Myr. At least 4 ECs originated in the event, together with the off-cluster star formation that probably gave rise to the scattered stars of NGC\,2175.Comment: Accepted by MNRA

Puerto franco : a la Junta de Comercio de Canarias: Habiendo examinado con mucho detenimiento la comunicacion del Sr. D. Manuel Rafael de vargas fechada en Madrid el 18 de diciembre ... con el objeto de que espresemos [sic] á esta Junta de Comercio nuestro sentir con respecto al proyecto de franquicia ..

Se trata de un dictamen a favor de establecer puertos francosTexto fechado en Santa Cruz de Tenerife a 28 de enero de 185

Influence of grape juice extraction methods on basic analytical parameters

Currently, for monitoring the ripening of grape berries, different devices are used to produce the juices to be analysed. Crushing the berries is a key step that determines the quantity of juice extracted and may impact it composition. The effect of different devices on analytical parameters of the musts produced were compared in this study. Samples from four grape varieties ('Cabernet-Sauvignon', 'Ekigaïna', 'Marselan' and 'Vermentino'), showing a variability of berry size and precocity, were crushed using six different devices (ASieves, Bag mixer®, Crusher, Manual, TPress and Blender). Whatever the pressing equipment, sugar concentrations of the must were not modified by the extraction method, unlike other parameters. pH and titratable acidity were slightly impacted by the crushing method without changing the ranking of the varieties. However, potassium concentrations were more impacted by the pressing method. Differences in mechanical forces applied to skins and seeds according to the pressing equipment used may release more or less potassium. This study clearly discarded a complete grinding of the samples for grape ripening monitoring: this method strongly modified the potassium content and, consequently, the pH and the titratable acidity of the musts

Improved survival following surgery and radiation therapy for olfactory neuroblastoma: analysis of the SEER database

<p>Abstract</p> <p>Background</p> <p>Olfactory Neuroblastoma is a rare malignant tumor of the olfactory tract. Reports in the literature comparing treatment modalities for this tumor are limited.</p> <p>Methods</p> <p>The SEER database (1973-2006) was queried by diagnosis code to identify patients with Olfactory Neuroblastoma. Kaplan-Meier was used to estimate survival distributions based on treatment modality. Differences in survival distributions were determined by the log-rank test. A Cox multiple regression analysis was then performed using treatment, race, SEER historic stage, sex, age at diagnosis, year at diagnosis and SEER geographic registry.</p> <p>Results</p> <p>A total of 511 Olfactory Neuroblastoma cases were reported. Five year overall survival, stratified by treatment modality was: 73% for surgery with radiotherapy, 68% for surgery only, 35% for radiotherapy only, and 26% for neither surgery nor radiotherapy. There was a significant difference in overall survival between the four treatment groups (p < 0.01). At ten years, overall survival stratified by treatment modality and stage, there was no significant improvement in survival with the addition of radiation to surgery.</p> <p>Conclusions</p> <p>Best survival results were obtained for surgery with radiotherapy.</p

Star clusters in the Sh2-132 complex: clues about the connection between embedded and open clusters

Embedded clusters are formed in molecular clouds where massive stars can produce HII regions. The detailed embedded-open cluster evolutionary connection as well as the origin of associations are yet to be unveiled. There appears to be a high infant mortality rate among embedded clusters and the few survivors evolve to open clusters. We study the colour-magnitude diagrams and structure of the star clusters related to the Sh2-132 HII region using the 2MASS database. Cluster fundamental and structural parameters are determined via MS and PMS isochrones and stellar radial density profiles. We report the discovery of four clusters. One of them is projected a few diameters away from the optical cluster Teutsch\,127 and appears to be deeply embedded, seen only in the infrared. Evidence is found that we are witnessing the dynamical transition from an embedded to an open cluster. An additional cluster is also close to Teutsch\,127 and might be associated with a bow-shock. We also study the CMD and structure of the open cluster Berkeley\,94 in Sh2-132 and a new cluster which is projected in the outskirts of the complex. Finally, we searched for star clusters around the two known Wolf-Rayet stars in the complex. One of them appears to be related to a compact cluster. Finally, the present analyses suggest early dynamical evolution for young star clusters.Comment: 12 pages, 20 figures, 6 table

Star clusters or asterisms? 2MASS CMD and structural analyses of 15 challenging targets

(Abridged) Poorly-populated star clusters may have photometric and structural properties not much different from asterisms, to the point that, in some cases, widely-used databases present conflicting classifications. We investigate the nature of a sample of challenging targets that have been classified either as star clusters or asterisms in different studies. A few objects are studied for the first time.Comment: Accepted by A&

Structures in surface-brightness profiles of LMC and SMC star clusters: evidence of mergers?

The LMC and SMC are rich in binary star clusters, and some mergers are expected. It is important to characterize single clusters, binary clusters and candidates to mergers. We selected a sample of star clusters in each Cloud with this aim. Surface photometry of 25 SMC and 22 LMC star clusters was carried with the ESO Danish 1.54 m telescope. 23 clusters were observed for the first time for these purposes. We fitted Elson, Fall and Freeman (1987, EFF) profiles to the data, deriving structural parameters, luminosities and masses. We also use isophotal maps to constrain candidates to cluster interactions.} {The structural parameters, luminosities and masses presented good agreement with those in the literature. Three binary clusters in the sample have a double profile. Four clusters (NGC 376, K 50, K 54 and NGC 1810) do not have companions and present as well important deviations from EFF profiles. The present sample contains blue and red Magellanic clusters. Extended EFF profiles were detected in some blue clusters. We find evidence that important deviations from the body of EFF profiles might be used as a tool to detect cluster mergers.Comment: 16 pages and 8 figures. Accepted by A&