Nucleotide sequence of the first cosmid from the Mycobacterium leprae genome project: structure and function of the Rif-Str regions

The nucleotide sequence of cosmid B1790, carrying the Rif-Str regions of the Mycobacterium leprae chromosome, has been determined. Twelve open reading frames were identified in the 36716bp sequence, representing 40% of the coding capacity. Five ribosomal proteins, two elongation factors and the β and β'subunits of RNA polymerase have been characterized and two novel genes were found. One of these encodes a member of the so-called ABC family of ATP-binding proteins while the other appears to encode an enzyme involved in repairing genomic lesions caused by free radicals. This finding may well be significant as M. leprae, an intracellular pathogen, lives within macrophages.

Da Serra de Tavira ao Rif marroquino: analogias e mitos

Dissertação de mest., Cultura Árabe e Islâmica e o Mediterrâneo, Faculdade de Ciências Humanas e Sociais, Universidade do Algarve, 2007

Transcriptional memory and switching in the Plasmodium falciparum rif gene family

The human malaria parasite Plasmodium falciparum expresses erythrocyte-surface directed variant antigens which are important virulence factors Many are transcribed from multigene families and presumably their mode of expression is strictly controlled to guarantee immune evasion in the human host. In order to elucidate the dynamics of rif transcription and to investigate if rif switching is comparable to var switching we monitored rif variant gene expression in parasites with different cytoadhesive properties as well as after a number of reinvasions. We found identical transcripts in parasite lines with different adhesive phenotypes suggesting that rif genes do not have a critical role in determining the cytoadhesion specificity of infected erythrocytes. We show for the first time that rif genes may show a conserved mode of transcription, maintaining the previously dominant rif transcript in subsequent reinvasions, but also observed rapid switching at rates up to 45% per generation, much higher than for the var gene family. (C) 2009 Elsevier B.V. All rights reserved.

Dynamic Activation and Repression of the Plasmodium falciparum rif Gene Family and Their Relation to Chromatin Modification

The regulation of variant gene expression in Plasmodium falciparum is still only partially understood. Regulation of var genes, the most studied gene family involved in antigenic variation, is orchestrated by a dynamic pattern of inherited chromatin states. Although recent evidence pointed to epigenetic regulation of transcribed and repressed rif loci, little is known about specific on/off associated histone modifications of individual rif genes. To investigate the chromatin marks for transcribed and repressed rif loci, we cultivated parasites and evaluated the transcriptional status of chosen rif targets by qRT-PCR and performed ChIP assays using H3K9ac and H3K9me3 antibodies. We then monitored changes in the epigenetic patterns in parasites after several reinvasions and also evaluated the "poised'' mark in trophozoites and schizonts of the same erythrocytic cycle by ChIP using H3K4me2 specific antibodies. Our results show that H3K9 is acetylated in transcribed rif loci and trimethylated or even unmodified in repressed rif loci. These transcriptional and epigenetic states are inherited after several reinvasions. The poised modification H3K4me2 showed a tendency to be more present in loci in trophozoites that upon progression to schizonts strongly transcribe the respective locus. However, this effect was not consistently observed for all monitored loci. While our data show important similarities to var transcription-associated chromatin modifications, the observed swiftly occurring modifications at rif loci and the absence of H3K9 modification point to a different dynamic of recruitment of chromatin modifying enzymes.

Fotoperiodismo en la Guerra del Rif (1909)

[ES] En 1909 España entró en guerra con Marruecos, un conflicto armado que ha pasado a la historia como la guerra del Rif. En el transcurso de la misma cambiaron muchas casas en España, pues una población descontenta logró derrocar a un gobierno que promovió la injusta medida de enviar al frente a los reservistas. Paralelamente a ello, esta guerra significó el inicio efectivo del fotoperiodismo en España, ya que las principales revistas gráficas enviaron al escenario del conflicto a reporteros que semanalmente enviaban sus fotografías desde el mismísimo campo de batalla.

Wie man die anderen verstehen soll und wie man über sie schreiben kann. Der Paris-Bericht Rifāʿa Rāfiʿ aṭ-Ṭahṭāwīs (1801-1873) als vielseitige Vermittlung von 'Kultur'

Im vorliegenden Essay wird eine Lesart des viel diskutierten Paris-Berichts von Rifāʿa aṭ-Ṭahṭāwī vorgestellt. Kontrastierend zu der Annahme, Ṭahṭāwī habe eine Reise aus einer Kultur in eine andere unternommen, soll hier dargelegt werden, wie sich aus dem Text des Ägypters ein eigenes Kulturverständnis erschließen lässt. Besonders Ṭahṭāwīs Bemühungen um die Übersetzung des französischen Begriffs 'civilisation' deuten auf ein plurales Verständnis von 'Kultur'. Denn im Text lassen sich diejenigen Dimensionen des Begriffs 'Kultur' finden, die auch aus der europäischen Geistesgeschichte rekonstruiert werden können: Kultur als bestimmter Lebensstil, als Prozessbegriff zur Beschreibung gesellschaftlicher Entwicklung und als kreative oder künstlerische Aktivität.

Qeren tûšiyyā : eine tzaiṭšrifṭ fir di raifere jugend tzur beferderung der ziṭṭlichqeiṭ und moraliṭeṭ

fon Heiman Šwabacher

Šrifṭen

J. L. Peretz

Šrifṭen : Gedichte und Prosa

Avraham Reizen

Poale-Tzijon šrifṭen

D. B. Borochow