A Possible Role for Short Introns in the Acquisition of Stroma-Targeting Peptides in the Flagellate Euglena gracilis

The chloroplasts of Euglena gracilis bounded by three membranes arose via secondary endosymbiosis of a green alga in a heterotrophic euglenozoan host. Many genes were transferred from symbiont to the host nucleus. A subset of Euglena nuclear genes of predominately symbiont, but also host, or other origin have obtained complex presequences required for chloroplast targeting. This study has revealed the presence of short introns (41–93 bp) either in the second half of presequence-encoding regions or shortly downstream of them in nine nucleus-encoded E. gracilis genes for chloroplast proteins (Eno29, GapA, PetA, PetF, PetJ, PsaF, PsbM, PsbO, and PsbW). In addition, the E. gracilis Pbgd gene contains two introns in the second half of presequence-encoding region and one at the border of presequence-mature peptide-encoding region. Ten of 12 introns present within presequence-encoding regions or shortly downstream of them identified in this study have typical eukaryotic GT/AG borders, are T-rich, 45–50 bp long, and pairwise sequence identities range from 27 to 61%. Thus single recombination events might have been mediated via these cis-spliced introns. A double crossing over between these cis-spliced introns and trans-spliced introns present in 5′-UTRs of Euglena nuclear genes is also likely to have occurred. Thus introns and exon-shuffling could have had an important role in the acquisition of chloroplast targeting signals in E. gracilis. The results are consistent with a late origin of photosynthetic euglenids

The Plastid Genome of Eutreptiella Provides a Window into the Process of Secondary Endosymbiosis of Plastid in Euglenids

Euglenids are a group of protists that comprises species with diverse feeding modes. One distinct and diversified clade of euglenids is photoautotrophic, and its members bear green secondary plastids. In this paper we present the plastid genome of the euglenid Eutreptiella, which we assembled from 454 sequencing of Eutreptiella gDNA. Comparison of this genome and the only other available plastid genomes of photosynthetic euglenid, Euglena gracilis, revealed that they contain a virtually identical set of 57 protein coding genes, 24 genes fewer than the genome of Pyramimonas parkeae, the closest extant algal relative of the euglenid plastid. Searching within the transcriptomes of Euglena and Eutreptiella showed that 6 of the missing genes were transferred to the nucleus of the euglenid host while 18 have been probably lost completely. Euglena and Eutreptiella represent the deepest bifurcation in the photosynthetic clade, and therefore all these gene transfers and losses must have happened before the last common ancestor of all known photosynthetic euglenids. After the split of Euglena and Eutreptiella only one additional gene loss took place. The conservation of gene content in the two lineages of euglenids is in contrast to the variability of gene order and intron counts, which diversified dramatically. Our results show that the early secondary plastid of euglenids was much more susceptible to gene losses and endosymbiotic gene transfers than the established plastid, which is surprisingly resistant to changes in gene content

Principles of audio watermarking

The article contains a brief overview of modern methods for embedding additional data in audio signals. It could have many reasons - for the purposes of access control or identification related to particular type of audio. This secret information is not “visible” for a user. This concept utilizes the imperfection of human auditory system. Simple data hiding into audio file has been proved in MATLAB

Comprehensive approach to the inventory control system improvement

This paper describes a methodology for inventory analysis and reduction, which was developed at the Department of Industrial Engineering, Faculty of Mechanical Engineering, University of Zilina. The methodology describes the optimal procedure for the application of basic analytical methods and tools in practice. The results of the analysis are in the algorithm linked to the subsequent actions realized to improve inventory management system and to minimize inventory level in the company. Described procedure is the result of methodology examination and verification in practical conditions of production enterprises. In the following sections of this paper, there are presented a comprehensive approach to the inventory analysis and the own algorithm, which contains 3 phases: inventory analysis on enterprise level, summary analysis of individual item groups and individual analysis of material items. In the last section, there are described examples of results from such analysis and conclusions. The presented approach is an attempt to create a universal procedure of analysis which integrates methods and tools described in various publications

Adaptive inventory control system for material items with continuous non-stationary demand

This paper describes an algorithm of dynamic inventory control system for large numbers of material items with continuous non-stationary demand. It uses principles of pull inventory control systems, statistical inventory analysis and joint replenishment inventory systems. This algorithm was processed in software module (VBA for Excel) and applied in practice. The target of described algorithm is to keep an optimum inventory level and optimum customer service level in terms of inventory control of items with non-stationary demand

Digital configurator of factories

This article introduces a new approach to the digital prototyping of factories. The problem we are describing here refers to a complex and lengthy decision-making process regarding the construction of a new factory or production. This specific area of research has been developed through many years, which is pointed in the first part of article. The solution we have offered brings a new methodology to the prototyping of factories. This solution helps to shorten the whole process of designing, building, operating and optimizing the production business. The most remarkable result of methodology application is digital configurator of factories. This configurator serves as a tool for designing and comprehensive investment assessment of the planned factories. In our view, these results represent an initial step towards managing the whole process of building a new factory, which will minimize both time and resource requirements