Combined use of 16S ribosomal DNA and 16S rRNA to study the bacterial community of polychlorinated biphenyl-polluted soil

The bacterial diversity assessed from clone libraries prepared from rRNA (two libraries) and ribosomal DNA (rDNA) (one library) from polychlorinated biphenyl (PCB)-polluted soil has been analyzed. A good correspondence of the community composition found in the two types of library was observed. Nearly 29% of the cloned sequences in the rDNA library were identical to sequences in the rRNA libraries. More than 60% of the total cloned sequence types analyzed were grouped in phylogenetic groups (a clone group with sequence similarity higher than 97% [98% for Burkholderia andPseudomonas-type clones]) represented in both types of libraries. Some of those phylogenetic groups, mostly represented by a single (or pair) of cloned sequence type(s), were observed in only one of the types of library. An important difference between the libraries was the lack of clones representative of the Actinobacteriain the rDNA library. The PCB-polluted soil exhibited a high bacterial diversity which included representatives of two novel lineages. The apparent abundance of bacteria affiliated to the beta-subclass of theProteobacteria, and to the genus Burkholderiain particular, was confirmed by fluorescence in situ hybridization analysis. The possible influence on apparent diversity of low template concentrations was assessed by dilution of the RNA template prior to amplification by reverse transcription-PCR. Although differences in the composition of the two rRNA libraries obtained from high and low RNA concentrations were observed, the main components of the bacterial community were represented in both libraries, and therefore their detection was not compromised by the lower concentrations of template used in this study

Site multiplicity of rare earth ions in III-nitrides

This presentation reviews recent lattice location studies of RE ions in GaN by electron emission channelling (EC) and X-ray absorption fine structure (XAFS) techniques. These studies agree that RE ions at low concentrations (whether they are incorporated during growth or introduced later by ion implantation) predominantly occupy Ga substitutional sites, as expected from considerations of charge equivalence. We combine this result with some examples of the welldocumented richness of optical spectra of GaN:RE3+ to suggest that the luminescence of these materials may be ascribed to a family of rather similar sites, all of which feature the REGa defect

Structural and optical properties of MOCVD AllnN epilayers

7] M.-Y. Ryu, C.Q. Chen, E. Kuokstis, J.W. Yang, G. Simin, M. Asif Khan, Appl. Phys. Lett. 80 (2002) 3730. [8] D. Xu, Y. Wang, H. Yang, L. Zheng, J. Li, L. Duan, R. Wu, Sci. China (a) 42 (1999) 517. [9] H. Hirayama, A. Kinoshita, A. Hirata, Y. Aoyagi, Phys. Stat. Sol. (a) 188 (2001) 83. [10] Y. Chen, T. Takeuchi, H. Amano, I. Akasaki, N. Yamada, Y. Kaneko, S.Y. Wang, Appl. Phys. Lett. 72 (1998) 710. [11] Ig-Hyeon Kim, Hyeong-Soo Park, Yong-Jo Park, Taeil Kim, Appl. Phys. Lett. 73 (1998) 1634. [12] K. Watanabe, J.R. Yang, S.Y. Huang, K. Inoke, J.T. Hsu, R.C. Tu, T. Yamazaki, N. Nakanishi, M. Shiojiri, Appl. Phys. Lett. 82 (2003) 718

La iniciación fulani a través de los relatos iniciáticos recopilados por Amadou Hampâté Bâ

Our aim is to examine the function of certain stories which have been used in Fulani initiation rites, to describe their main features and to specify the reasons that lead the writer to collect them. These stories are literary works, the tools used by initiation masters to show their particular vision of the world and the path to follow to move towards moral perfection. As they are traditions, we will analyse the social context in which they appear and focus on those who transmitted them to the oral tradition researcher, Amadou Hampâté Bâ.Nuestro objetivo es examinar la función de ciertos relatos orales fulani cuyos personajes experimentan procesos iniciáticos, describir sus principales características y precisar el motivo que conduce al escritor Hampâté Bâ a recopilarlos. Dichas narraciones son obras literarias, herramientas de las que se sirven los maestros iniciadores para mostrar una particular visión del mundo y del camino a seguir para acercarse a la perfección moral. Como tradiciones que son, analizaremos el entorno social en el que surgen y nos detendremos en aquellos que se las transmiten a Amadou Hampâté Bâ

Evaluation of the ATB 32C, automicrobic system and API 20C using clinical yeast isolates

The ATB 32C (bioMerieux, Spain), AMS-YBC (Vitek System, bioMerieux, Spain) and API 20C (bioMerieux, Spain) systems were evaluated for their reliability in identifying 100 clinical yeast isolates. The ATB 32C, AMS-YBC and API 20C systems correctly identified 97%, 98% and 100% of the isolates respectively. There were no significant differences in incubation periods between ATB 32C and AMS-YBC systems. One isolate of Candida tropicalis was wrongly identified by the ATB 32C and the AMS-YBC systems. The Saccharomyces cerevisiae isolate was wrongly identified by the ATB 32C system while the AMS-YBC failed to identify it and a third isolate of Candida krusei was wrongly identified by the ATB 32C system. The overall accuracy and rapidity of the ATB 32C and AMS-YBC systems were sufficient to permit recommendation of either of these systems for routine use in the clinical microbiology laboratory, although the first system enjoys the advantages of having a wider data-base and the possibility of manual reading

Variación estacional del contenido de esporas de cladosporium en la atmósfera de Córdoba

En este trabajo se estud ia l a incidencia de esporas del género Cladosporium en l a atmósfera de Córdoba durante el período comprendido entre Abril de ¡gs3 a Narzo de 1984, med i ante la utilización de los mét odos de muestreo grav imétr ico y volumétrico . Se comparan los resultados obtenidos con los aportados por otros autores y se relacionan con los parámetros climatológicosIn this paper the incidente of spores of Cladosporium f rom Apri l 1983 to March 1984 in the atmosphere of Córdoba , by means of g.ravirnetric and volumetric methods is studied. The data obtained related wi t h t he clima tic parameters are comparated wi th those published by other author