LiBeB: High and low energy cosmic ray production and comparison with neutrino induced nucleosynthesis in SNII

We present new calculations of LiBeB production by accelerated particles with various compositions and energy spectra ranging from low energies to relativistic energies, and various ambient medium metallicities ($Z/Z_\odot$). The observed, essentially constant, Be/Fe ratio as a function of $Z/Z_\odot$ can be best understood if the metallicity of the accelerated particles (high energy or low energy) does not vary much with $Z/Z_\odot$. This could be achieved if the particles are accelerated directly from the ejecta of Type II supernovae (SNII) and not from the interstellar medium. Using the observed Be/Fe and the fact that most of the Fe at low $Z/Z_\odot$ is from SNII, we derive the energy content in accelerated particles per SNII (a few times 10$^{50}$ erg). We show that additional $^{11}$B production by neutrinos is consistent with the available data, allowing a neutrino yield from SNII less than or equal to the nominal published yields. We further show that the observed $^6$Li at low $Z/Z_\odot$ suggests that the accelerated particles responsible for the LiBeB at such $Z/Z_\odot$ are confined to low energies and have a relatively high He/O abundance.Comment: 9 pages with 4 emdedded figures, uuencoded, compressed, tared, style files included. In press Nuclei In the Cosmos, Nuclear Physics, Conference Proceeding

Antikaon condensation and the metastability of protoneutron stars

We investigate the condensation of $\bar K^0$ meson along with $K^-$ condensation in the neutrino trapped matter with and without hyperons. Calculations are performed in the relativistic mean field models in which both the baryon-baryon and (anti)kaon-baryon interactions are mediated by meson exchange. In the neutrino trapped matter relevant to protoneutron stars, the critical density of $K^-$ condensation is shifted considerably to higher density whereas that of $\bar K^0$ condensation is shifted slightly to higher density with respect to that of the neutrino free case. The onset of $K^-$ condensation always occurs earlier than that of $\bar K^0$ condensation. A significant region of maximum mass protoneutron stars is found to contain $\bar K^0$ condensate for larger values of the antikaon potential. With the appearance of $\bar K^0$ condensation, there is a region of symmetric nuclear matter in the inner core of a protoneutron star. It is found that the maximum mass of a protoneutron star containing $K^-$ and $\bar K^0$ condensate is greater than that of the corresponding neutron star. We revisit the implication of this scenario in the context of the metastability of protoneutron stars and their evolution to low mass black holes.Comment: 26 pages; Revtex; 8 figures include

Observations of metals in the intra-cluster medium

Because of their deep gravitational potential wells, clusters of galaxies retain all the metals produced by the stellar populations of the member galaxies. Most of these metals reside in the hot plasma which dominates the baryon content of clusters. This makes them excellent laboratories for the study of the nucleosynthesis and chemical enrichment history of the Universe. Here we review the history, current possibilities and limitations of the abundance studies, and the present observational status of X-ray measurements of the chemical composition of the intra-cluster medium. We summarise the latest progress in using the abundance patterns in clusters to put constraints on theoretical models of supernovae and we show how cluster abundances provide new insights into the star-formation history of the Universe.Comment: 28 pages, 12 figures, accepted for publication in Space Science Reviews, special issue "Clusters of galaxies: beyond the thermal view", Editor J.S. Kaastra, Chapter 16; work done by an international team at the International Space Science Institute (ISSI), Bern, organised by J.S. Kaastra, A.M. Bykov, S. Schindler & J.A.M. Bleeke

Models for Type I supernovae

Two rather disjoint scenarios for Type I supernovae are presented. One is based upon mass accretion by a white dwarf in a binary system. The second involves a star having some 8 to 10 times the mass of the sun which may or may not be a solitary star. Despite the apparent dissimilarities in the models it may be that each occurs to some extent in nature for they both share the possibility of producing substantial quantities of /sup 56/Ni and explosions in stars devoid of hydrogen envelopes. These are believed to be two properties that must be shared by any viable Type I model

The Analysıs, Evaluatıon And The Preservatıon-Rehabılıtatıon Proposal Of Rural Settlement Pattern Of Buyukalan Vıllage At Aksekı Provınce, Antalya

Bu çalışmanın amacı Antalya'nın Akseki ilçesine bağlı olan Büyükalan köyünün, tarihi ve kültürel dokusunun geçmişini ve gelişimini araştırmak, günümüze ulaşan sivil mimari, yapım tekniği, malzemeleri tespit etmek ve belgelemek, tarihi doku içindeki yeni yapılaşmalara öneriler getirmek ve bölgenin turizme uygun özelliklerinin geliştirilmesine katkıda bulunmaktır. Hazırlanan çalışmanın birinci bölümünde, çalışmanın amacı, kapsamı ve yöntemi anlatılmıştır. İkinci bölümde köyün içinde bulunduğu bölgenin özelliklerine ve tanımlara yer verilmiştir. Üçüncü bölümde Büyükalan köyünün mimari, fiziksel ve sosyal analizleri yapılarak grafik anlatımlarla değerlendirilmiştir. Dördüncü bölümde Büyükalan köyünün kentsel ilişkiler bazında sorun, olanak ve potansiyelleri araştırılmıştır. Beşinci bölümde bölgenin turizm potansiyeli belirlenmiş, uygunluk durumu saptanmıştır. Altıncı bölümde genel müdahale kararları belirlenerek, koruma yaklaşımları açıklanmıştır. Yedinci bölüm sonuç bölümüdür, bu bölümde köyün kültürel değerleriyle birlikte gelecek kuşaklara aktarılması için gerekli koruma kararları sunulmuştur.The purpose of this study is to investigate the history and development of historical and cultural doctrine to identify and document civil architecture, construction technique and materials reaching up to now, to bring suggestions for new constructions in historical doctrine, to contribute to the development of appropriate tourism characteristics of Büyükalan village located in the Akseki district of Antalya. In the first part of the prepared work, the purpose, scope and method of study have been presented. In the second part, the characteristics and definitions of the area in which the village is located have been given. In the third part, the architectural, physical and social analyzes of Büyükalan village have been made through evaluations by graphics. In the fourth part, the problems, possibilities and potentials of Büyükalan village have been researched on the basis of urban relations. In the fifth part, the tourism potential of the area has been identified and the eligibility status has been determined. In the sixth part, general intervention decisions have been determined and preservation strategies have been developed. The seventh part is the conclusion part in which the necessary preservation decisions for the transfer of the village with its cultural values to future generations have been suggested

The origin and abundances of the chemical elements revisited

The basic scheme of nucleosynthesis (building of heavy elements from light ones) has held up very well since it was first proposed more than 30 years ago by E.M. Burbidge, G.R. Burbidge, A.G.W. Cameron, W.A. Fowler, and F. Hoyle. Significant advances in the intervening years include (a) observations of elemental and a few isotopic ratios in many more extrasolar-system sites, including metal-poor dwarf irregular galaxies, where very little has happened, and supernovae and their remnants, where a great deal has happened, (b) recognition of the early universe as good for making all the elements up to helium, (c) resolution of heavy element burning in stars into separate carbon, neon, oxygen, and silicon burning, with fine tuning of the resulting abundances by explosive nucleosynthesis in outgoing supernova shock waves, (d) clarification of the role of Type I supernovae, (e) concordance between elements produced in short-lived and long-lived stars with those that increased quickly and slowly over the history of the galaxy, and (f) calibration of calculations of the evolution and explosion of massive stars against the detailed observations of SN 1987A. The discussion presupposes a reader (a) with some prior knowledge of astronomy at the level of recognizing what is meant by an A star and an AGB star and (b) with at least a mild interest in how we got to where we currently are. © 1991 Springer-Verlag

Clinical, histological and molecular profiling of different stages of alcohol-related liver disease.

Alcohol-related liver disease (ALD) ranges from never-decompensated ALD (ndALD) to the life-threatening decompensated phenotype, known as alcohol-related hepatitis (AH). A multidimensional study of the clinical, histological and molecular features of these subtypes is lacking. Two large cohorts of patients were recruited in an international, observational multicentre study: a retrospective cohort of patients with ndALD (n=110) and a prospective cohort of patients with AH (n=225). Clinical, analytical, immunohistochemistry and hepatic RNA microarray analysis of both disease phenotypes were performed. Age and mean alcohol intake were similar in both groups. AH patients had greater aspartate amino transferase/alanine amino transferase ratio and lower gamma-glutamyl transferase levels than in ndALD patients. Patients with AH demonstrated profound liver failure and increased mortality. One-year mortality was 10% in ndALD and 50% in AH. Histologically, steatosis grade, ballooning and pericellular fibrosis were similar in both groups, while advanced fibrosis, Mallory-Denk bodies, bilirubinostasis, severe neutrophil infiltration and ductular reaction were more frequent among AH patients. Transcriptome analysis revealed a profound gene dysregulation within both phenotypes when compare to controls. While ndALD was characterised by deregulated expression of genes involved in matrisome and immune response, the development of AH resulted in a marked deregulation of genes involved in hepatocyte reprogramming and bile acid metabolism. Despite comparable alcohol intake, AH patients presented with worse liver function compared with ndALD patients. Bilirubinostasis, severe fibrosis and ductular reaction were prominent features of AH. AH patients exhibited a more profound deregulation of gene expression compared with ndALD patients