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Search Results: 1 - 10 of 5738 matches for " Igor Babiak "
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História xylofónu a podstata zvuku dreva
Martin ?ulík,Igor Babiak
Technológia vzdelávania , 2011,
Abstract: lánok sa zaoberá materiálom a z asti históriou netradi ného hudobného nástroja, ktorého zvuk je produkovany prírodnym materiálom akym je drevo. Tymto nástrojom je xylofón. Kvalita zvuku je hlavne sp tá s hudobnymi nástrojmi. Pri subjektívnom posudzovaní sa hodnotia najm charakteristiky ako je farba, vyraznos , jasnos zvuku a mnohé iné subjektívne ukazova-tele. Av ak na v etky tieto charakteristiky vplyva vo ve kej miere kvalita pou itého materiálu, truktúra a jeho fyzikálno-akustické ukazovatele. Tieto ukazovatele m u by sú as ou objektív-neho hodnotenia materiálu, ktory priamo ovplyvňuje kvalitu zvuku hudobného nástroja. Hodno-tiacimi ukazovate mi kvality dreva v tomto prípade sú hustota ρ, modul pru nosti v pozd nom smere E, akustická kon tanta A, rychlos zvuku v pozd nom smere c a logaritmicky dekrement útlmuJ. Súhrnne nazyvané aj ako fyzikálno-akustické charakteristiky (FACH).
Maternal gene expression in Atlantic halibut (Hippoglossus hippoglossus L.) and its relation to egg quality
Maren Mommens, Jorge MO Fernandes, Teshome T Bizuayehu, Sylvie L Bolla, Ian A Johnston, Igor Babiak
BMC Research Notes , 2010, DOI: 10.1186/1756-0500-3-138
Abstract: A maternal EST library containing 2341 sequences was constructed by suppressive subtractive hybridisation. Thirty genes were selected for expression studies; 23 novel genes and 7 genes with documented roles in early development. The expressions of twenty-one selected genes were measured by qPCR from fertilization to the 10-somite stage. Three genes were identified as strictly maternal genes that were expressed until the start of gastrulation; askopos (kop), si:dkey-30j22.9 (Tudor family member), and Tudor 5 protein (Tdrd5). The expressions of 18 genes at the 8-cell stage were correlated with egg quality parameters. The majority of genes showed either no or very minor correlations with egg quality parameter. However, two genes correlated positively with hatching success (r> 0.50, HHC00353: r = 0.58, p < 0.01; HHC01517: r = 0.56, p < 0.01) and one gene (HHC00255) was negatively correlated with the percentage of normal blastomeres (r = -0.62, p < 0.05).During this study we have related maternal levels of gene expression to hatching success in fish. Poor hatching success was not correlated with a general decrease in transcript abundance but with low transcript levels of some specific genes. Thus, the molecular mechanisms leading to low Atlantic halibut egg quality cannot be entirely explained by post-ovulatory aging.Atlantic halibut (Hippoglossus hippoglossus L.) is considered a valuable species for cold water marine fish farming, but current production suffers from a bottleneck during fry production for on-growing. Variable egg quality is a common problem in commercial fish farming [1,2]. Good quality eggs have been defined as eggs exhibiting high survival rates at fertilization, larval hatching and larval first feeding [3]. Poor egg quality leads to major problems during the early production stage, including high embryonic and larval mortality and body malformations [1,4]. Domesticated Atlantic halibut can release eggs naturally, but they are usually not fertilized [5
Characterization of Novel Precursor miRNAs Using Next Generation Sequencing and Prediction of miRNA Targets in Atlantic Halibut
Teshome Tilahun Bizuayehu, Jorge M. O. Fernandes, Steinar D. Johansen, Igor Babiak
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0061378
Abstract: Background microRNAs (miRNAs) are implicated in regulation of many cellular processes. miRNAs are processed to their mature functional form in a step-wise manner by multiple proteins and cofactors in the nucleus and cytoplasm. Many miRNAs are conserved across vertebrates. Mature miRNAs have recently been characterized in Atlantic halibut (Hippoglossus hippoglossus L.). The aim of this study was to identify and characterize precursor miRNA (pre-miRNAs) and miRNA targets in this non-model flatfish. Discovery of miRNA precursor forms and targets in non-model organisms is difficult because of limited source information available. Therefore, we have developed a methodology to overcome this limitation. Methods Genomic DNA and small transcriptome of Atlantic halibut were sequenced using Roche 454 pyrosequencing and SOLiD next generation sequencing (NGS), respectively. Identified pre- miRNAs were further validated with reverse–transcription PCR. miRNA targets were identified using miRanda and RNAhybrid target prediction tools using sequences from public databases. Some of miRNA targets were also identified using RACE-PCR. miRNA binding sites were validated with luciferase assay using the RTS34st cell line. Results We obtained more than 1.3 M and 92 M sequence reads from 454 genomic DNA sequencing and SOLiD small RNA sequencing, respectively. We identified 34 known and 9 novel pre-miRNAs. We predicted a number of miRNA target genes involved in various biological pathways. miR-24 binding to kisspeptin 1 receptor-2 (kiss1-r2) was confirmed using luciferase assay. Conclusion This study demonstrates that identification of conserved and novel pre-miRNAs in a non-model vertebrate lacking substantial genomic resources can be performed by combining different next generation sequencing technologies. Our results indicate a wide conservation of miRNA precursors and involvement of miRNA in multiple regulatory pathways, and provide resources for further research on miRNA in non-model animals.
Differential expression patterns of conserved miRNAs and isomiRs during Atlantic halibut development
Teshome T Bizuayehu, Carlos FC Lanes, Tomasz Furmanek, B?rd O Karlsen, Jorge MO Fernandes, Steinar D Johansen, Igor Babiak
BMC Genomics , 2012, DOI: 10.1186/1471-2164-13-11
Abstract: miRNA profiling using SOLiD deep sequencing technology revealed a total of 199 conserved, one novel antisense, and one miRNA* mature form. Digital expression profiles of selected miRNAs were validated using reverse transcription quantitative PCR. We found developmental transition-specific miRNA expression. Expression of some miRNA* exceeded the guide strand miRNA. We revealed that nucleotide truncations and/or additions at the 3' end of mature miRNAs resulted in size variants showing differential expression patterns during the development in a number of miRNA families. We confirmed the presence of isomiRs by cloning and Sanger sequencing. Also, we found inverse relationship between expression levels of sense/antisense miRNAs during halibut development.Developmental transitions during early development of Atlantic halibut are associated with expression of certain miRNA types. IsomiRs are abundant and often show differential expression during the development.Atlantic halibut, Hippoglossus hippoglossus L., the largest flatfish of Atlantic Ocean, is a species of commercial interest to the aquaculture industry. Halibut's early developmental stages are prolonged and morphologically defined [1,2]. The critical developmental stages, when dramatic changes in signaling, physiology and morphology occur, include: (i) maternal to zygote transition (MZT), when maternally stocked transcripts are degraded and zygote transcripts take control over the development; (ii) organogenesis, when the germ layers are formed; (iii) hatching, when the embryo becomes a free-swimming larva; (iv) first feeding, when active movement, visualization, recognition of prey, and exogenous feeding begin; and (v) metamorphosis, the most dramatic morphological and behavioral change in a flatfish during the transition from a symmetric post-larval to an asymmetric juvenile stage, when migration of one eye towards the other one occurs across the skull [1].MiRNAs are small (18 - 26 nucleotides) non-coding RNAs
Daily Rhythmicity of Clock Gene Transcripts in Atlantic Cod Fast Skeletal Muscle
Carlo C. Lazado, Hiruni P. S. Kumaratunga, Kazue Nagasawa, Igor Babiak, Alessia Giannetto, Jorge M. O. Fernandes
PLOS ONE , 2014, DOI: 10.1371/journal.pone.0099172
Abstract: The classical notion of a centralized clock that governs circadian rhythmicity has been challenged with the discovery of peripheral oscillators that enable organisms to cope with daily changes in their environment. The present study aimed to identify the molecular clock components in Atlantic cod (Gadus morhua) and to investigate their daily gene expression in fast skeletal muscle. Atlantic cod clock genes were closely related to their orthologs in teleosts and tetrapods. Synteny was conserved to varying degrees in the majority of the 18 clock genes examined. In particular, aryl hydrocarbon receptor nuclear translocator-like 2 (arntl2), RAR-related orphan receptor A (rora) and timeless (tim) displayed high degrees of conservation. Expression profiling during the early ontogenesis revealed that some transcripts were maternally transferred, namely arntl2, cryptochrome 1b and 2 (cry1b and cry2), and period 2a and 2b (per2a and per2b). Most clock genes were ubiquitously expressed in various tissues, suggesting the possible existence of multiple peripheral clock systems in Atlantic cod. In particular, they were all detected in fast skeletal muscle, with the exception of neuronal PAS (Per-Arnt-Single-minded) domain-containing protein (npas1) and rora. Rhythmicity analysis revealed 8 clock genes with daily rhythmic expression, namely arntl2, circadian locomotor output cycles kaput (clock), npas2, cry2, cry3 per2a, nuclear receptor subfamily 1, group D, member 1 (nr1d1), and nr1d2a. Transcript levels of the myogenic genes myogenic factor 5 (myf5) and muscleblind-like 1 (mbnl1) strongly correlated with clock gene expression. This is the first study to unravel the molecular components of peripheral clocks in Atlantic cod. Taken together, our data suggest that the putative clock system in fast skeletal muscle of Atlantic cod has regulatory implications on muscle physiology, particularly in the expression of genes related to myogenesis.
CREEP PARAMETERS OF SPRUCE WOOD IN HIGH TEMPERATURE ENVIRONMENT
Laga?a,Rastislav; Babiak,Marian; Krakovsky,Alexander;
Maderas. Ciencia y tecnología , 2008, DOI: 10.4067/S0718-221X2008000100002
Abstract: the paper presents partial results of an ongoing project dealing with thermal diffusion and mechanical behavior of spruce wood in high temperature environment (up to 180°c). the objective of this part of study was to obtain rheological properties of spruce wood which will be used in future modeling of wood performance in high temperatures. oven dry samples (30 x 30 x 700 mm3) underwent constant mechanical loading in bending parallel to grain (smax = 7.3 mpa, load span 600 mm) at three temperature levels, namely 120°c, 150°c and 180°c, respectively.. deflection of the samples was measured using optical non-contact method. four rheological parameters of burger?s model, describing immediate elastic, delayed visco-elastic as well as plastic (permanent material change) behavior, were determined which show the strong influence of the temperature on creep propagation. experimental setup, results and further application in the modeling of high temperature treatment are discussed
CREEP PARAMETERS OF SPRUCE WOOD IN HIGH TEMPERATURE ENVIRONMENT
Rastislav Laga?a,Marian Babiak,Alexander Krakovsky
MADERAS : Ciencia y Tecnología , 2008,
Abstract: The paper presents partial results of an ongoing project dealing with thermal diffusion and mechanical behavior of spruce wood in high temperature environment (up to 180°C). The objective of this part of study was to obtain rheological properties of spruce wood which will be used in future modeling of wood performance in high temperatures. Oven dry samples (30 x 30 x 700 mm3) underwent constant mechanical loading in bending parallel to grain (s max = 7.3 MPa, load span 600 mm) at three temperature levels, namely 120°C, 150°C and 180°C, respectively.. Deflection of the samples was measured using optical non-contact method. Four rheological parameters of Burger’s model, describing immediate elastic, delayed visco-elastic as well as plastic (permanent material change) behavior, were determined which show the strong influence of the temperature on creep propagation. Experimental setup, results and further application in the modeling of high temperature treatment are discussed
Diphenyl (isopropylamido)phosphate
Fahimeh Sabbaghi,Mehrdad Pourayoubi,Marek Nečas,Michal Babiak
Acta Crystallographica Section E , 2012, DOI: 10.1107/s1600536812047940
Abstract: The P atom in the title compound, C15H18NO3P, is in a distorted tetrahedral P(O)(O)2N environment; the bond angles at P are in the range 98.16 (6)–115.82 (6)°. In the crystal, adjacent molecules are linked via N—H...O=P hydrogen bonds into a chain running parallel to the b axis. The methyl groups are disordered over two sets of sites in a 0.677 (14):0.323 (14) ratio. The crystal studied was a non-merohedral twin with a refined minor component of 22.31 (4)%.
Fibers of secondary ligno-cellulose materials and their influence on properties of insulating fiberboards
Henrich Lübke,Vlastimil Borùvka,Marian Babiak
Drvna Industrija , 2008,
Abstract: This paper deals with the influence of addition of abraded fiber, as a partial substitute of softwood fibers, on the properties of insulating fiberboard. The fiber used was characterized by fractional composition of fiber length according to McNett (STN 50 0289) using the apparatus for the measurement of fiber length in aqueoussuspension (ADV) and according to Brecht-Holl (STN 50 0289) by the determination of water retained by fiber, speed of dewatering and defibrator seconds. Insulating fiberboards were prepared with different content of abraded fiber. Mechanical properties (bending strength and tension strength perpendicular to the board plane) as well as physical properties (swelling, water uptake, thermal conductivity, thermal diffusivity specific heat and volumetricspecific heat) were measured for the boards.
Almost Linear Büchi Automata
Tomá? Babiak,Vojtěch ?ehák,Jan Strej?ek
Electronic Proceedings in Theoretical Computer Science , 2009, DOI: 10.4204/eptcs.8.2
Abstract: We introduce a new fragment of Linear temporal logic (LTL) called LIO and a new class of Buechi automata (BA) called Almost linear Buechi automata (ALBA). We provide effective translations between LIO and ALBA showing that the two formalisms are expressively equivalent. While standard translations of LTL into BA use some intermediate formalisms, the presented translation of LIO into ALBA is direct. As we expect applications of ALBA in model checking, we compare the expressiveness of ALBA with other classes of Buechi automata studied in this context and we indicate possible applications.
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