Vacuumless kinks systems from vacuum ones, an example

Some years ago, Cho and Vilenkin, introduced a model which presents topological solutions, despite not having degenerate vacua as is usually expected. Here we present a new model with topological defects, connecting degenerate vacua but which in a certain limit recovers precisely the one proposed originally by Cho and Vilenkin. In other words, we found a kind of parent model for the so called vacuumless model. Then the idea is extended to a model recently introduced by Bazeia et al. Finally, we trace some comments the case of the Liouville model.Comment: 11 pages, 4 figure

Computer-aided growth medium design for optimal growth of Chinese hamster ovary cells

Systems biology and metabolic engineering tools hold a tremendous promise in improving biomanufacturing attributes since they represent one of the auspicious modern biomanufacturing optimization approaches. The emergence of omics tools and bioinformatics enables the development of new strategies to optimize expression platforms in general and Chinese hamster ovary (CHO) cell lines in particular, which are the most commonly used cell lines for the production of recombinant proteins. Computational modelling combined with CHO cell omics data can help optimizing growth parameters, as well as improving the final product yield. Here we use a genome-scale metabolic model (GSMM) of CHO to study the growth and metabolic behavior of CHO cells in response to environmental stimuli, such as changing amino acids levels. To study this influence, GSMM combined with an in-house developed algorithm was employed to determine the minimal medium formulation to sustain optimal growth for non-recombinant as well as for recombinant CHO cells lines. Optflux tool was used to predict metabolic behavior of the cells in response to the environmental constraints tested. Based on in silico predictions, growth yield value was improved for non-recombinant and recombinant CHO cells lines comparing to previously reported data. Furthermore, toxic by-products such as ammonium were decreased to their lowest levels. In silico-based approaches for medium optimization are powerful tools for predicting the metabolic interconnexion in the cell and for selecting potential experimental conditions for further validation in bioreactor systems.info:eu-repo/semantics/publishedVersio

Comparison of structural makeup of four hulless barley varieties using diffuse reflectance infrared fourier transform (DRIFT) spectroscopy

Non-Peer ReviewedThe objective of this study was to determine molecular structural makeup features of 3 newer hulless barley varieties (CDC Fibar, CDC Rattan, and HB08302) in comparison to the conventional feed-type barley variety in Canada (CDC McGwire) using diffuse reflectance infrared fourier transform (DRIFT) spectroscopy. The items included IR absorbed intensity (IR intensity unit, KM) peak area attributed to protein amide I (ca. 1715-1575 cm-1), amide II (ca. 1575-1490 cm-1), total carbohydrate (CHO; ca. 1188-820 cm-1), and structural carbohydrate (StCHO; ca. 1277-1190 cm-1); and ratio of amide I to II, amide I to CHO, and CHO to StCHO. There were no differences among barley varieties in CHO. While, CDC Fibar was greatest in protein amide I and II peak areas, as well as the ratio of protein amide I to CHO among barley varieties. Newer barley varieties were similar to each other, but were different from CDC McGwire in protein amide I to II ratios. In summary, DRIFT spectroscopy associated with both univariate and multivariate techniques can be used as tool to discriminate and classify the inherent molecular structural features among the different barley varieties

Cobalamin inactivation induces formyltetrahydrofolate synthetase

AbstractLoss of cobalamin function produces profound changes in the metabolism of formate. There is impaired synthesis of formyltetrahydropteroylglutamate synthetase (CHO-H4,PteGlu), accumulation of endogenous formate and impaired utilization of [14C]formate. There are contradictory reports on the effect of cobalamin inactivation on CHO-H4PteGlu synthetase. This study confirms a significant increase in synthetase activity following cobalamin inactivation

Composers' Forum: Student Works, April 10, 1990

This is the concert program of the Composers' Forum: Student Works performance on Tuesday, April 10, 1990 at 12:30 p.m., at the Boston University Concert Hall, 855 Commonwealth Avenue, Boston, Massachusetts. Works performed were ME-A-RI by Nami Cho, Music Box by Juley B. Kurs, Control by Juley B. Kurs, Three Sketches for two pianos by Nami Cho, Preludes for piano by Juley B. Kurs, and Up and Down: Inner Rounds by John Saylor. Digitization for Boston University Concert Programs was supported by the Boston University Humanities Library Endowed Fund

Molecular and functional characteristics of seven-transmembrane-domain receptor APJ

APJ is a member of seven-transmembrane-domain receptors, but its ligand had not been identified for a long time. I prepared CHO cells expressing APJ (CHO-A10 cells), and searched for the endogenous ligand for APJ by monitoring specific signal transduction in CHO-A10 cells. ...Thesis (Ph. D. in Science)--University of Tsukuba, (B), no. 1690, 2001.1.31Includes bibliographical referencesTitlepage,Tble of Contents -- Summary,Abbreviations -- Introduction -- Materials and Methods -- Results -- Discussion -- Ackknowledgements,References -- Table,Figures and Figure Legend

Eun Kyeong Cho Assistant Professor of Education, COLA, travels to South Korea

Professor Cho traveled to South Korea in summer 2011 to make a presentation at an international seminar and to meet colleagues to continue an on going collaboration with South Korean researchers at the Korea Institute of Child Care and Education (KICCE)

High-yield antibody production using targeted integration and engineering CHO host

To identify the high expression sites in the CHO cells, we employed NGS to analyze the integration sites of a high producing cell line (titer \u3e 3g/L). The pair-end reads with one read mapped to the vector and the other read mapped to the CHO reference genome are extracted to identify the integration sites. To test the expression activity of the integration sites, we employed CRISPR/Cas9 to specifically integrate the antibody gene into CHO genome for expression. Our data showed 4 integration sites are in the high producing cell line. Among the 4 integration site, one integration site was tested by CRISPR/Cas9 for target integration of antibody gene for expression. The target integrated cell pool present higher expression level (130 mg/L/copy) and less copy number when compared other integration sites. Through single-copy integration method, we can also achieve 60-150 mg/L/copy in a batch culture. About 80% of the single-copy cell clones were stable at generation 60. We have also applied the CHO-specific microarray transcriptomics technology to identify genes that contribute to high productivity. Transfection of our proprietary dual promoter vector J 1.0 resulting in 1.65 to 2.4 fold increase in the expression in engineered CHO DXB11 host. Through fed-batch process development, 3 – 5 g/L mAb productivity can be achieved through targeted integration and engineered CHO host

Generation of desirable CHO cell factories with predictive culture performance using CRISPR/Cas9-mediated genome engineering

Chinese hamster ovary (CHO) cells are widely used in the biopharmaceutical industry as a host for the production of complex pharmaceutical proteins. Thus, genome engineering of CHO cells for improved product quality and yield is of great interest. Here, I will demonstrate our latest advances in improving the efficiency of CRISPR/Cas9-mediated genome engineering to generate attractive knockout and knockin CHO cell lines. Analysis of the dynamics and efficiency of the technology will be demonstrated for genes involved in glycosylation and apoptosis. Combined with multiplexing and fluorescent enrichment, application of CRISPR/Cas9 genome editing facilitated disruption of several genes simultaneously and accelerated analysis of gene combinations. Engineered CHO cell lines with multiple disruptions of genes involved in apoptosis and glycosylation showed prolonged growth and improved glycosylation profiles. Site-specific integration of transgenes mediated by CRISPR/Cas9 and homology directed repair facilitated generation of targeted integrants with improved clonal homogeneity compared to random integrants. Improvements in the efficiency of our targeted integration platform combined with identification of good integration sites has facilitated precise insertion and expression of genes encoding biopharmaceuticals. In the end, characterization of engineered CHO cell lines with desirable properties generated using combinations of gene disruptions and insertions will be presented. The proven efficacy of genome engineering mediated by CRISPR/Cas9 technology has a large potential to accelerate current CHO engineering efforts. Together with high-throughput technologies, computational models and systems biology approaches, genome editing can pave the way for accelerated generation of desirable CHO cell factories with predictive culture performance

Multi-omic modeling of translational efficiency for synthetic gene design

Controlled expression of recombinant genes in CHO cells for advanced cell engineering will require precise, coordinated control of the synthetic processes that underpin the production of specific recombinant products or the optimal stoichiometry of functional effector proteins for multigene engineering applications. Although control of recombinant gene transcription in CHO host cells is now possible, technologies that enable control of recombinant mRNA translation rate are lacking. This is undesirable as in eukaryotic cells, cellular mRNA concentration itself may only explain a relatively small proportion of the variation in cellular protein abundance; mRNA translation rate is by far the most important contributor to cellular protein concentration. We have taken a top-down, genome-scale computational modeling approach to develop computational design tools that enable control of recombinant gene translational activity in CHO cells. Through a combination of pulsed stable isotope labelling of amino acids in cell culture (pSILAC) and RNA-Seq based analysis of the CHO cell transcriptome we quantified the translational efficiency of \u3e 4000 mRNAs. Based on informatic reconstruction of CHO mRNAs (to include untranslated and coding sequences) we built and trained a gaussian process regression model using over 250 defined mRNA sequence features to enable validated in silico prediction of mRNA translational efficiency in CHO cells from mRNA sequence. Using this genome-scale empirical modeling we created a computational gene analysis and design platform that permits both prediction of the translational efficiency of natural and recombinant mRNAs in CHO cells and de novo design of synthetic mRNAs with predictable translational activity. This platform will be employed to (i) maximize the efficiency of recombinant mRNA translation for easy-to-express proteins, (ii) optimize the rate of mRNA translation for difficult-to-express proteins and (iii) control the stoichiometry of product synthesis in multigene expression systems