Generation of a diverse repertoire of antigen receptor specificities via DNA recombination underpins adaptive immunity. In this issue ofGenes&Development, Carmona and colleagues (pp. 909-917) provide novel insights into the origin and function of recombination-activating gene 1 (RAG1) and RAG2, the lymphocyte-specific components of the recombinase involved in the process.

Please cite this paper as: Paydar S, Farhadi P, Ghaffarpasand F. Advanced Trauma Life Support (ATLS) Tips to Be Kept In Mind. Bull Emerg Trauma. 2013; 1(1):49-51. Corresponding author: Fariborz Ghaffarpasand Address: Trauma Research Center, Shahid Rajaee Trauma Hospital, Chamran Avenue, PO Box: 713451876 Shiraz, Iran. Tel: +98-917-3095214 Fax: +98-711-6254206 e-mail: fariborz_ghaffarpasand@yaho...

The hypothesis that chromosome size affects the rate and distribution of meiotic crossovers in budding yeast was tested. Map distance and interference were measured in the same genetic intervals present on either small (340 and 508 kb) or large (917 and 1085 kb) chromosomes, respectively. No differences were observed.

1 Facultad de Ciencias Naturales. Universidad Nacional de la Patagonia San Juan Bosco (U.N.P.S.J.B.) Km 4, Comodoro Rivadavia, (9000) Chubut, Argentina. 2 Facultad de Química, Bioquímica y Farmacia. Universidad Nacional de San Luis (U.N.S.L.), Chacabuco 917, (5700) San Luis, Argentina. 3 Facultad de Ciencias Bioquímicas y Farmacéuticas, Farmacognosia, Universidad Nacional de Rosario, Suipacha 5...

Germline genomic methylation is essential for gamete identity and integrity in mammals. The study by Kuramochi-Miyagawa and colleagues (908-917) in the previous issue of Genes & Development links the process of DNA methylation-dependent repression of retrotranspons with the presence of piwi-interacting RNAs (piRNAs) in fetal male germ cells undergoing de novo methylation.

A famous “curious identity” of Wallis gives a representation of the constant π in terms of a simply structured infinite product of fractions. Sondow and Yi [Amer. Math. Monthly 117 (2010), 912-917] identified a general scheme for evaluating Wallis-type infinite products. The main purpose of this paper is to discuss an interpretation of the scheme by means of Pólya urn models.

Pavol BOŽEK, Elena PIVARČIOVÁ 1) Slovak Technical University Faculty of Materials Science and Technology, Institute of Applied Informatics, Automation and Mathematics, Hajdóczyho 1, 917 24 Trnava, Slovakia 2) Technical University in Zvolen Faculty of Environmental and Manufacturing Technology, Department of Informatics and Automation Technologies, TG. Masaryka 24, 960 53 Zvolen, Slovakia pavol....

Reseña: Francisco García González (ed.), Vivir en soledad. Viudedad, soltería y abandono el mundo rural (España América Latina, siglos XVI-XXI), Madrid: Iberoamericana/Vervuert, Tiempo Emulado: 70, 2020, 520 pp. ISBN 978-84-9192-010-6 (Iberoamericana), 978-3-96456-916-5 (Vervuert) 978-3-96456-917-2 (eBook).

Fisheries provide an important source of food, employment, income, and recreation for people throughout the world (Allison, 2001). Appreciations of fisheries and aquatic ecosystems have been accompanied by increasing concern about the effects of growing human populations and activity on aquatic life and water quality. (lious, et al., 1996). Out of the many links associated to man`s negative imp...