Evolutionary importance of translation elongation factor eEF1A variant switching:eEF1A1 down-regulation in muscle is conserved in Xenopus but is controlled at a post-transcriptional level

Translation elongation isoform eEF1A1 has a pivotal role in protein synthesis and is almost ubiquitously expressed. In mice and rats that transcription of the gene encoding eEF1A1 is downregulated to undetectable levels in muscle after weaning; eEF1A1 is then replaced by a separately encoded but closely related isoform eEF1A2, which has only previously been described in mammals. We now show that not only is eEF1A2 conserved in non-mammalian vertebrate species, but the down-regulation of eEF1A1 protein in muscle is preserved in Xenopus, with the protein being undetectable by adulthood. Interestingly, though, this down-regulation is controlled post-transcriptionally, and levels of full-length eEF1A1 mRNA remain similar to those of eEF1A2. The switching off of eEF1A1 in muscle is therefore sufficiently important to have evolved through the use of repression operating at different levels in different species. The 3'UTR of eEF1A1 is highly conserved and contains predicted binding sites for several miRNAs, suggesting a possible method for controlling of expression. We suggest that isoform switching may have evolved because of a need for certain cell types to modify the well-established non-canonical functions of eEF1A1

Coping strategies for the participants in the Antarctic expedition

The ХХV Bulgarian Antarctic expedition on the Livingston isles, which included scientists and alpinists, began in November 2016. The aim of the present research is to study security need and sensation seeking and to find a relation with the participants'preferred coping strategies in highly risky activities in an extreme climatic and social environment. Subject of the study were 21 participants in the Antarctic expedition, mean age 27 and 70. We have used: Security need scale; Scale for assessment of Psychic Instability and Sensation Seeking Scale and the Bulgarian adaptation of Coping Orientations to Problems Experienced scale - COPE 1. Low levels of Security need are established. The leading subscales of the Sensation Seeking Scale are those of sensation seeking, followed by dysfunctional impulsiveness. Functional impulsiveness is characterized with the lowest values. The cognitive engagement coping strategies are the main ones, whereas cognitive and emotional disengagement strategies are the least used. The results from the regression analysis show that the high levels of sensation seeking influence negatively the use of the strategic behavioral disengagement. The present study adds to the understanding the role of security need and sensation seeking being a motivational power of human behavior, which is in the base of the desire to participate in difficult and challenging missions in extreme conditions in highly risky activities.El inicio de la 25ª Expedición Antártica Búlgara en las islas de Livingston en la que han participado científicos y escaladores, ha sido el noviembre 2016. El propósito de este estudio es investigar la necesidad de seguridad, la búsqueda de sensaciones y revelar las interrelaciones con las estrategias de coping preferidas en actividades de alto riesgo en las condiciones climáticas extremas y sociales. El sujeto del estudio han sido 21 participantes en la Expedición Antártica de edad media entre 27 y 70. Están utilizados: escala de la necesidad de seguridad, escala para la evaluación de la inestabilidad psíquica y de la búsqueda de sensaciones y la adaptación búlgara del cuestionario de las estrategias preferidas para combatir el estrés - COPE 1. Se establecen niveles bajos de necesidad de seguridad. Las subescalas principales de la escala de buscar sensaciones son la búsqueda de sensaciones, seguida de la impulsividad disfuncional. La impulsividad funcional se caracteriza por los valores más bajos. Las estrategias de afrontamiento cognitivo son las principales, mientras que las estrategias cognitivas y de desmovilización emocional son las menos utilizadas. Los resultados del análisis de regresión muestran que los altos niveles de búsqueda de sensaciones influyen negativamente en el uso de la desviación estratégica del comportamiento. El estudio facilita la comprensión del papel de la necesidad de seguridad y la búsqueda de sensaciones como un poder motivacional del comportamiento humano, que está en la base del deseo de participar en misiones difíciles en condiciones extremas en actividades de alto riesgo

Forces in a 3D magnetic field of conducting current contours

The present paper deals with 3D magnetic field analysis of conducting current contours. The magnetic field and forces were calculated analytically and by FEM applying the Comsol Multiphysics package. Forces were calculated by the Maxwell stress tensor and by volume force density. Numerical results for real and ideal contours with the same linear dimensions are discussed. Comparison between analytical and numerical data shows satisfactory agreement

Learning by Doing in the Context of Modern Information and Media Literacy of Students in “Library and Information Management” in ULSIT Using the Digital Collection “Bulgarian Revival”

The purpose of this article is to evaluate the effectiveness of learning by doing as a practical tool for managing the training of students in "Library Management" at the ULSIT, Sofia, Bulgaria, by using the creation of project 'Data Base “Bulgarian Revival Towns” (CD), financed by Bulgarian Ministry of Education, Youth and Science (1/D002/144/13.10.2011) headed by Prof. DSc Ivanka Yankova, which aims to create new information resource for the towns which will serve the needs of scientific researches. By participating in generating the an array in the database through searching, selection and digitization of documents from these period, at the same time students get an opportunity to expand their skills to work effectively in a team, finding the interdisciplinary, a causal connection between the studied items, objects and subjects and foremost – practical experience in the field of digitization, information behavior, strategies for information search, etc. This method achieves good results for the accumulation of sustainable knowledge and it generates motivation to work in the field of library and information professions

Chromatin structure and methylation of rat rRNA genes studied by formaldehyde fixation and psoralen cross-linking

By using formaldehyde cross-linking of histones to DNA and gel retardation assays we show that formaldehyde fixation, similar to previously established psoralen photocross-linking, discriminates between nucleosome-packed (inactive) and nucleosome-free (active) fractions of ribosomal RNA genes. By both cross-linking techniques we were able to purify fragments from agarose gels, corresponding to coding, enhancer and promoter sequences of rRNA genes, which were further investigated with respect to DNA methylation. This approach allows us to analyse independently and in detail methylation patterns of active and inactive rRNA gene copies by the combination of HpaII and MspI restriction enzymes. We found CpG methylation mainly present in enhancer and promoter regions of inactive rRNA gene copies. The methylation of one single HpaII site, located in the promoter region, showed particularly strong correlation with the transcriptional activit

Researches on wood-destroying fungi division Ascomycota, classis Ascomycetes

Orchards aging and agrotechnical cares reduction have led to suitable development conditions of a large number of wood-destroying fungi that had never been a problem for the intensive fruit growing. This caused the necessity of their study in the main orchard regions of our country. The research was conducted from 2003 to 2005 on the basis of expeditionary-geographical method. Twelve species of wood destroying Ascomycota fungi have been identified. Both their parasitic activity degree and phylogenetic and ontogenetic specialization level have been defined. Species with mutual hosts - fruit or forest trees have been found. That fact makes possible the infection accumulation and transfer from forest to agricultural ecosystems which is of considerable importance for the mountain fruit growing

A role for SUMO modification in transcriptional repression and activation

Since the discovery of the SUMO (small ubiquitin-like modifier) family of proteins just over a decade ago, a plethora of substrates have been uncovered including many regulators of transcription. Conjugation of SUMO to target proteins has generally been considered as a repressive modification. However, there are now a growing number of examples where sumoylation has been shown to activate transcription. Here we discuss whether there is something intrinsically repressive about sumoylation, or if the outcome of this modification in the context of transcription will prove to be largely substrate-dependent. We highlight some of the technical challenges that will be faced by attempting to answer this question

Study of the effects of breed on some innate immunity parameters in rams

Investigations were carried out on 26 rams from the breeds Karakachan and Copper-Red Shoumen. The non-specific immune parameters, phagocytic activity of leukocytes, bactericidal activity of phagocytes systems (oxygen-dependent and oxygen independent) and total plasma protein level were evaluated. Phagocytic response was evaluated against S. aureus 209-P with a certain percentage of active phagocytes (phagocytic index) and the number of absorbed particles per one phagocytic cells (phagocyte number). Phagocytosis completion index was defined as the percentage of the microbial cells that have been destroyed by phagocytes after incubation. State of the oxygen-dependent bactericidal systems of phagocytes was assessed in vitro using the NBT test, which reflects the ability of superoxide restore NBT in diphormazane. NBT test was evaluated by the degree of reduction in spontaneous and stimulated reactions, taking into account the intracellular deposits diphormazane. Our studies and results shows that the rams from the two local Bulgarian breeds have a high activity of innate immune parameters and that’s may be useful and important in the breeding programs as an indicator of resistance and highly tolerance to oxidative stress