University of Seville

About: University of Seville is a education organization based out in Seville, Andalucía, Spain. It is known for research contribution in the topics: Population & Context (language use). The organization has 20098 authors who have published 47317 publications receiving 947007 citations. The organization is also known as: Universidad de Sevilla.

Impairment of replication fork progression mediates RNA polII transcription-associated recombination

Abstract: Homologous recombination safeguards genome integrity, but it can also cause genome instability of important consequences for cell proliferation and organism development. Transcription induces recombination, as shown in prokaryotes and eukaryotes for both spontaneous and developmentally regulated events such as those responsible for immunoglobulin class switching. Deciphering the molecular basis of transcription-associated recombination (TAR) is important in understanding genome instability. Using novel plasmid-borne recombination constructs in Saccharomyces cerevisiae, we show that RNA polymerase II (RNAPII) transcription induces recombination by impairing replication fork progression. RNAPII transcription concomitant to head-on oncoming replication causes a replication fork pause (RFP) that is linked to a significant increase in recombination. However, transcription that is codirectional with replication has little effect on replication fork progression and recombination. Transcription occurring in the absence of replication does not affect either recombination or replication fork progression. The Rrm3 helicase, which is required for replication fork progression through nucleoprotein complexes, facilitates replication through the transcription-dependent RFP site and reduces recombination. Therefore, our work provides evidence that one mechanism responsible for TAR is RNAP-mediated replication impairment.

Accumulation of astaxanthin and lutein in Chlorella zofingiensis (Chlorophyta).

Abstract: When grown photoautotrophically, Chlorella zofingiensis strain CCAP 211/14 accumulates a significant amount of valuable carotenoids, namely astaxanthin and lutein, of increasing demand for use as feed additives in fish and poultry farming, as colorants in food, and in health care products. Under standard batch-culture conditions, this microalgal strain exhibits high values of both growth rate (about 0.04 h−1) and standing cell population (over 1011 cells l−1, or 7 g dry weight l−1). Lutein, in a free (unesterified) form, was the prevalent carotenoid during early stages of cultivation (over 0.3 pg cell−1, equal to 4 mg g−1 dry weight, or 20 mg l−1 culture), whereas esterified astaxanthin accumulated progressively, to reach a maximum (over 0.1 pg cell−1, equal to 1.5 mg g−1 dry weight, or 15 mg l−1 culture) in the late stationary phase. A differential response of lutein and astaxanthin accumulation was also recorded with regard to the action of some environmental and nutritional factors. C. zofingiensis CCAP 211/14 represents a unique model system for analyzing the differential regulation of the levels of primary (lutein) and secondary (astaxanthin) carotenoids. Relevant also from the biotechnological viewpoint, this photosynthetic organism, with outstanding attributes for fast photosynthetic growth and carotenoid accumulation, might prove most valuable for its application to the mass production of either or both lutein and astaxanthin.

The biophysical design of plant cuticles: an overview

Abstract: The outer surfaces of epidermal cell walls are impregnated with an extracellular matrix called the cuticle. This composite matrix provides several functions at the interface level that enable plants to thrive in different habitats and withstand adverse environmental conditions. The lipid polymer cutin, which is the main constituent of the plant cuticle, has some unique biophysical properties resulting from its composition and structure. This review summarizes the progress made towards understanding the biophysical significance of this biopolymer with special focus on its structural, thermal, biomechanical, and hydric properties and relationships. The physiological relevance of such biophysical properties is discussed in light of existing knowledge on the plant cuticle.

The emotional impact of bullying and cyberbullying on victims: a European cross-national study.

Abstract: :::::::::::::::: :::::::::::::::: ::::::::: Past research has demonstrated the effects of bullying can be severe and long term for the individuals involved. The main aim of this study is to analyze the emotional impact on victims of traditional bullying, both direct and indirect forms, and of cyberbullying through mobile phones and the Internet. A sample of 5,862 adolescents from three different countries, Italy (N = 1,964), Spain (N = 1,671), and England (N = 2,227), responded to a questionnaire that asked if they had experience of various forms of bullying, and the consequent emotional impact. The results show that both traditional bullying and cyberbullying have a significant prevalence in the samples. Emotional responses are linked to types of bullying. Analysis of answers identified specific emotional profiles for the different types of bullying and cyberbullying. Direct bullying and cyberbullying via mobile phone showed similar profiles, and also indirect bullying and cyberbullying using the Internet. Similarities and differences between profiles are discussed and some hypotheses are presented to explain the results. In addition, school grade, gender, country, and severity of bullying episodes were related to the specific emotional profiles of each type of bullying. Aggr. Behav. 38:342–356, 2012. C