A catalog of 120 NGC open star clusters

A sample of 145 JHK--2MASS observations of NGC open star clusters is studied, of which 132 have never been studied before. Twelve are classified as non-open clusters and 13 are re-estimated self-consistently, after applying the same methods in order to compare and calibrate our reduction procedures. The fundamental and structural parameters of the 120 new open clusters studied here are derived using color-magnitude diagrams of JHK Near-IR photometry with the fitting of solar metallicity isochrones. We provide here, for the first time, a catalog of the main parameters for these 120 open clusters, namely, diameter, distance, reddening and age.Comment: 18 pages, 7 figures, Published in Journal of The Korean Astronomical Society 44: 1-11, 2011 Februar

The role of augurin in the hypothalamo-pituitary-adrenal axis and the regulation of food intake

Novel secreted peptides represent an important field of research because delineation of their function affords new insights into the pathophysiological processes causing disease, and provides opportunities for the development of pharmacological therapies. Augurin is a recently identified secreted peptide of unknown function expressed in the central nervous system (CNS), pituitary, and several endocrine tissues. Because of its expression pattern I hypothesised that augurin may be involved in the neuroendocrine system. I therefore investigated the effects of central injection of augurin on the hypothalamo-pituitary axes and food intake in male Wistar rats. Intracerebroventricular (ICV) or intraparaventricular nucleus (iPVN) injection of augurin increased plasma adrenocorticotrophic hormone (ACTH) and corticosterone levels compared with vehicle-injected controls. Augurin also increased the release of corticotrophin releasing hormone (CRH) from hypothalamic explants, and pre-treatment with a CRH receptor antagonist in vivo prevented the rise in ACTH and corticosterone caused by ICV augurin, suggesting activation the hypothalamo-pituitary-adrenal (HPA) axis via by the release of CRH from neurons in the PVN. In addition to stimulating the HPA axis, iPVN injection of augurin at the start of either the light or dark phase caused a robust increase in food intake. To assess whether augurin might have a physiological role in the regulation of the HPA axis or food intake, I investigated its endogenous distribution in the rat CNS using immunohistochemistry and in situ hybridisation histochemistry. Augurin positive neurons were present in several regions of the CNS including the hypothalamus and the dorsal vagal complex of the brainstem, a distribution consistent with a possible role in neuroendocrine function. Augurin is therefore anatomically positioned to play a role in the hypothalamic regulation of the HPA axis and food intake. While the data presented suggest a novel role for augurin, these are preliminary studies. Currently, little is known about the physiology of the augurin system. Further characterisation of the neuroanatomy, identification of receptors, and the development of receptor agonists and antagonists would provide further data on the physiological role of augurin, and on the potential therapeutic benefits of manipulating the augurin system

A rapid and convergent synthesis of the integrastatin core

The tetracyclic core of the integrastatin natural products has been prepared in a convergent and rapidmanner. Our strategy relies upon a palladium(II)-catalyzed oxidative cyclization to form the central [3.3.1]-dioxabicycle of the natural product core. Overall, the core has been completed in only 4 linear steps from known compounds

Aryne Acyl-Alkylation in the General and Convergent Synthesis of Benzannulated Macrolactone Natural Products: An Enantioselective Synthesis of (−)-Curvularin

A general approach for the synthesis of benzannulated macrolactone natural products utilizing an aryne acyl-alkylation reaction is described. Toward this end, the total syntheses of the natural products (−)-curvularin, curvulin, and (−)-diplodialide C are reported. Furthermore, the aryne insertion technology has enabled the rapid conversion of simple diplodialide natural products to curvularin, thereby connecting these two biosynthetically distinct classes of compounds via synthetic methods

Creating Imagined and Real Communities Through Classroom Activities

Young learners have strong negative associations with formal learning and uninteresting content. Furthermore, it is challenging for students to speak English outside the classroom in a TL removed context. To rectify this situation, the presenter will demonstrate some engaging and interesting activities to encourage student participation and make learning fun

Radial velocities and metallicities from infrared Ca II triplet spectroscopy of open clusters: Berkeley 26, Berkeley 70, NGC 1798, and NGC 2266

Context: Open clusters are ideal test particles for studying the formation and evolution of the Galactic disk. However, the number of clusters with information about their radial velocities and chemical compositions remains largely insufficient. Aims: We attempt to increase the number of open clusters with determinations of radial velocities and metallicities from spectroscopy. Methods: We acquired medium-resolution spectra (R~8000) in the region of the infrared Ca II triplet lines (~8500\AA) for several stars in four open clusters with the long-slit spectrograph IDS at the 2.5m Isaac Newton Telescope, Roque de los Muchachos Observatory, Spain. Radial velocities were obtained by cross-correlating the observed spectra with those of two template stars. We used the relationships available in the literature between the strength of infrared Ca II lines and metallicities to derive the metal content of each cluster. Results: We provide the first spectroscopic determinations of radial velocities and metallicities for the open clusters Berkeley 26, Berkeley 70, NGC 1798, and NGC 2266. We obtain =68$\pm$12, -15$\pm$7, 2$\pm$10, and -16$\pm$15 km s$^{-1}$ for Berkeley 26, Berkeley 70, NGC 1798, and NGC 2266, respectively. For Berkeley 26 we derive a metallicity of [Fe/H]=-0.35$\pm$0.17 dex. Berkeley 70 has a solar metallicity of [Fe/H]=-0.01$\pm$0.14 dex, while NGC 1798 has a slightly lower metal content of [Fe/H]=-0.12$\pm$0.07 dex. Finally, we derive a metallicity of [Fe/H]=-0.38$\pm$0.06 dex for NGC 2266.Comment: 7 pages, 5 figures, accepted for publication in A&