104 research outputs found

    The effect of cooling rate on the microstructure of nodular cast iron

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    Abstract The study gives the results of the investigations concerning an effect of the casting cooling rate ( casting made from nodular iron used as a starting material for austempering to produce ADI) on the morphology of nodular graphite and metallic matrix composition. The features of the microstructure morphology were determined on a LUCIA computer program using castings of 10, 20, 40 and 60 mm diameter. It has been proved that increasing the casting diameter from 10 to 60 mm (i.e. reducing the cooling rate) increases the content of graphite from 10 to 12% and an average area of the precipitations from about 150 to 440 µm 2 , while it reduces the number of the graphite precipitations in 1 mm 2 from about 700 to 260, the mean value of the shape factor from 0,96 to 0,84, and pearlite content in the matrix from about 96% to 84%. The chemical composition seems to have no significant effect, the only exception being Mo whose presence increases in a visible way pearlite content in the matrix at each cooling rate. The obtained results, and specifically the distribution of the frequencies of occurrence of the examined morphological features of graphite, confirm the vast possibilities that the LUCIA computer program of image analysis offers in evaluation of the effect of technological parameters on cast iron microstructure

    THE INTERDEPENDENCE OF FUNCTIONAL AND DYNAMIC STABILITY OF THE 16-18 YEARS OLD BASKETBALL PLAYERS - A PILOT STUDY

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    We aimed to determine the interdependence between functional and dynamic stability of young basketball players. Nineteen, young basketball players took part in the experiment. They were tested with Y Balance TestTM for functional stability and with *Drift protocol" of the Optojump Next System for dynamic stability. The correlation analysis showed interdependencies between functional balance testing and dynamic performance. The Composite Reach Score is highly associated with individual leg jump power. Also there are significant dependencies between jumping stability in AP and ML planes and reach distances in specified directions. Other significant correlations indicate the need for conducting functional testing in parallel with dynamic trials in order to achieve wider picture of the athletes perforrnance

    Glycolytic flux in Saccharomyces cerevisiae is dependent on RNA polymerase III and its negative regulator Maf1.

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    Protein biosynthesis is energetically costly, is tightly regulated and is coupled to stress conditions including glucose deprivation. RNA polymerase III (RNAP III)-driven transcription of tDNA genes for production of tRNAs is a key element in efficient protein biosynthesis. Here we present an analysis of the effects of altered RNAP III activity on the Saccharomyces cerevisiae proteome and metabolism under glucose-rich conditions. We show for the first time that RNAP III is tightly coupled to the glycolytic system at the molecular systems level. Decreased RNAP III activity or the absence of the RNAP III negative regulator, Maf1 elicit broad changes in the abundance profiles of enzymes engaged in fundamental metabolism in S. cerevisiae In a mutant compromised in RNAP III activity, there is a repartitioning towards amino acids synthesis de novo at the expense of glycolytic throughput. Conversely, cells lacking Maf1 protein have greater potential for glycolytic flu

    Modification of EGF-Like Module 1 of Thrombospondin-1, an Animal Extracellular Protein, by O-Linked N-Acetylglucosamine

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    Thrombospondin-1 (TSP-1) is known to be subject to three unusual carbohydrate modifications: C-mannosylation, O-fucosylation, and O-glucosylation. We now describe a fourth: O-β-N-acetylglucosaminylation. Previously, O-β-N-acetylglucosamine (O-β-GlcNAc) was found on a threonine in the loop between the fifth and sixth cysteines of the 20th epidermal growth factor (EGF)-like module of Drosophila Notch. A BLAST search based on the Drosophila Notch loop sequence identified a number of human EGF-like modules that contain a similar sequence, including EGF-like module 1 of TSP-1 and its homolog, TSP-2. TSP-1, which has a potentially modifiable serine in the loop, reacted in immuno-blots with the CTD110.6 anti-O-GlcNAc antibody. Antibody reactivity was diminished by treatment of TSP-1 with β-N-acetylhexosaminidase. TSP-2, which lacks a potentially modifiable serine/threonine in the loop, did not react with CTD110.6. Analysis of tandem modules of TSP-1 localized reactivity of CTD110.6 to EGF-like module 1. Top-down mass spectrometric analysis of EGF-like module 1 demonstrated the expected modifications with glucose (+162 Da) and xylose (+132 Da) separately from modification with N-acetyl hexosamine (+203 Da). Mass spectrometric sequence analysis localized the +203-Da modification to Ser580 in the sequence 575CPPGYSGNGIQC586. These results demonstrate that O-β-N-acetylglucosaminylation can occur on secreted extracellular matrix proteins as well as on cell surface proteins

    Full production cycle performance of gene-edited, sterile Atlantic salmon - growth, smoltification, welfare indicators and fillet composition

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    Using germ cell-free (GCF), sterile, dnd-knockout salmon for farming could solve the problems associated with precocious maturation and genetic introgression of farmed breeds into wild populations. However, prior to using GCF fish in the salmon farming industry, it is crucial to understand if, or how, the GCF phenotype differs from wild type (WT) counterparts in terms of growth and welfare. To characterize the GCF phenotype throughout a production cycle, we reared GCF and WT salmon in indoor common garden tanks for 3 years, until harvest size. Regarding body size, smoltification markers (mRNA levels of gill Na+/K+-ATPase [NKA] subunits), plasma stress indicators (pH, glucose, sodium, chloride, calcium), relative heart size, prevalence of vertebra deformities and fillet proximate composition, GCF fish could not be distinguished from WTs. Transient differences were detected in plasma concentrations of lactate and osmolality, and only a few genes were differentially expressed in WT and GCF transcriptomes of muscle and pituitary. At harvest, fillets from GCF and WT salmon contained the same amount of omega-3 fatty acids, however the relative content of omega-3 fatty acids was higher in GCF compared to WT males. Towards harvest size, body growth rate, condition factor and relative liver size were significantly higher in WT than in GCF fish, probably relating to initiation of puberty in WTs. Since GCF salmon never become sexually mature, it is possible to postpone the time of harvest to exploit the growth potential uninhibited by sexual maturation. In conclusion, GCF salmon performed to a large extent similarly to their WT counterparts but had the clear advantage of never maturing.publishedVersio

    Stone Age Yersinia pestis genomes shed light on the early evolution, diversity, and ecology of plague

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    The bacterial pathogenYersinia pestisgave rise to devastating outbreaks throughouthuman history, and ancient DNA evidence has shown it afflicted human populations asfar back as the Neolithic.Y. pestisgenomes recovered from the Eurasian Late Neolithic/Early Bronze Age (LNBA) period have uncovered key evolutionary steps that led to itsemergence from aYersinia pseudotuberculosis-like progenitor; however, the number ofreconstructed LNBA genomes are too few to explore its diversity during this criticalperiod of development. Here, we present 17Y. pestisgenomes dating to 5,000 to 2,500y BP from a wide geographic expanse across Eurasia. This increased dataset enabled usto explore correlations between temporal, geographical, and genetic distance. Ourresults suggest a nonflea-adapted and potentially extinct single lineage that persistedover millennia without significant parallel diversification, accompanied by rapid dis-persal across continents throughout this period, a trend not observed in other pathogensfor which ancient genomes are available. A stepwise pattern of gene loss provides fur-ther clues on its early evolution and potential adaptation. We also discover the presenceof theflea-adapted form ofY. pestisin Bronze Age Iberia, previously only identified inin the Caucasus and the Volga regions, suggesting a much wider geographic spread ofthis form ofY. pestis. Together, these data reveal the dynamic nature of plague’s forma-tive years in terms of its early evolution and ecology

    Using Y-chromosome capture enrichment to resolve haplogroup H2 shows new evidence for a two-Path Neolithic expansion to Western Europe

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    Uniparentally-inherited markers on mitochondrial DNA (mtDNA) and the non-recombining regions of the Y chromosome (NRY), have been used for the past 30 years to investigate the history of humans from a maternal and paternal perspective.Researchers have preferred mtDNA due to its abundance in the cells, and comparatively high substitution rate. Conversely, the NRY is less susceptible to back mutations and saturation, and is potentially more informative than mtDNA owing to its longer sequence length. However, due to comparatively poor NRY coverage via shotgun sequencing, and the relatively low and biased representation of Y-chromosome variants on capture arrays such as the 1240K, ancient DNA studies often fail to utilize the unique perspective that the NRY can yield.Here we introduce a new DNA enrichment assay, coined YMCA (Y-mappable capture assay), that targets the “mappable” regions of the NRY. We show that compared to low-coverage shotgun sequencing and 1240K capture, YMCA significantly improves the coverage and number of sites hit on the NRY, increasing the number of Y-haplogroup informative SNPs, and allowing for the identification of previously undiscovered variants.To illustrate the power of YMCA, we show that the analysis of ancient Y-chromosome lineages can help to resolve Y-chromosomal haplogroups. As a case study, we focus on H2, a haplogroup associated with a critical event in European human history: the Neolithic transition. By disentangling the evolutionary history of this haplogroup, we further elucidate the two separate paths by which early farmers expanded from Anatolia and the Near East to western Europe.Competing Interest StatementThe authors have declared no competing interest.Introduction Results and Discussion - Validating the performance of YMCA - Application of YMCA to YHG H2 as a case study - Identifying diagnostic SNPs for improved YHG H2 resolution Discussion Materials and Methods - Data - Contamination quality filtering - Method of Y Haplogroup Assignment - Comparing the Performance of our Y-capture Array Phylogenetic Tree Reconstructio

    Full production cycle performance of gene-edited, sterile Atlantic salmon - growth, smoltification, welfare indicators and fillet composition

    Get PDF
    Using germ cell-free (GCF), sterile, dnd-knockout salmon for farming could solve the problems associated with precocious maturation and genetic introgression of farmed breeds into wild populations. However, prior to using GCF fish in the salmon farming industry, it is crucial to understand if, or how, the GCF phenotype differs from wild type (WT) counterparts in terms of growth and welfare. To characterize the GCF phenotype throughout a production cycle, we reared GCF and WT salmon in indoor common garden tanks for 3 years, until harvest size. Regarding body size, smoltification markers (mRNA levels of gill Na+/K+-ATPase [NKA] subunits), plasma stress indicators (pH, glucose, sodium, chloride, calcium), relative heart size, prevalence of vertebra deformities and fillet proximate composition, GCF fish could not be distinguished from WTs. Transient differences were detected in plasma concentrations of lactate and osmolality, and only a few genes were differentially expressed in WT and GCF transcriptomes of muscle and pituitary. At harvest, fillets from GCF and WT salmon contained the same amount of omega-3 fatty acids, however the relative content of omega-3 fatty acids was higher in GCF compared to WT males. Towards harvest size, body growth rate, condition factor and relative liver size were significantly higher in WT than in GCF fish, probably relating to initiation of puberty in WTs. Since GCF salmon never become sexually mature, it is possible to postpone the time of harvest to exploit the growth potential uninhibited by sexual maturation. In conclusion, GCF salmon performed to a large extent similarly to their WT counterparts but had the clear advantage of never maturing
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