High efficiency multifrequency feed

Antenna systems and particularly compact and simple antenna feeds which can transmit and receive simultaneously in at least three frequency bands, each with high efficiency and polarization diversity are described. The feed system is applicable for frequency bands having nominal frequency bands with the ratio 1:4:6. By way of example, satellite communications telemetry bands operate in frequency bands 0.8 - 1.0 GHz, 3.7 - 4.2 GHz and 5.9 - 6.4 GHz. In addition, the antenna system of the invention has monopulse capability for reception with circular or diverse polarization at frequency band 1

Flagellar region 3b supports strong expression of integrated DNA and the highest chromosomal integration efficiency of the Escherichia coli flagellar regions.

The Gram-negative bacterium Escherichia coli is routinely used as the chassis for a variety of biotechnology and synthetic biology applications. Identification and analysis of reliable chromosomal integration and expression target loci is crucial for E. coli engineering. Chromosomal loci differ significantly in their ability to support integration and expression of the integrated genetic circuits. In this study, we investigate E. coli K12 MG1655 flagellar regions 2 and 3b. Integration of the genetic circuit into seven and nine highly conserved genes of the flagellar regions 2 (motA, motB, flhD, flhE, cheW, cheY and cheZ) and 3b (fliE, F, G, J, K, L, M, P, R), respectively, showed significant variation in their ability to support chromosomal integration and expression of the integrated genetic circuit. While not reducing the growth of the engineered strains, the integrations into all 16 target sites led to the loss of motility. In addition to high expression, the flagellar region 3b supports the highest efficiency of integration of all E. coli K12 MG1655 flagellar regions and is therefore potentially the most suitable for the integration of synthetic genetic circuits.M. J. and J. W. A. are supported by EPSRC.This is the final version of the article. It first appeared from Wiley via http://dx.doi.org/10.1111/1751-7915.1229

High molecular weight DNA assembly in vivo for synthetic biology applications.

DNA assembly is the key technology of the emerging interdisciplinary field of synthetic biology. While the assembly of smaller DNA fragments is usually performed in vitro, high molecular weight DNA molecules are assembled in vivo via homologous recombination in the host cell. Escherichia coli, Bacillus subtilis and Saccharomyces cerevisiae are the main hosts used for DNA assembly in vivo. Progress in DNA assembly over the last few years has paved the way for the construction of whole genomes. This review provides an update on recent synthetic biology advances with particular emphasis on high molecular weight DNA assembly in vivo in E. coli, B. subtilis and S. cerevisiae. Special attention is paid to the assembly of whole genomes, such as those of the first synthetic cell, synthetic yeast and minimal genomes.Cordial thanks to all researchers who contributed to these advances in DNA assembly. M.J. and J.W.A. are supported by the Engineering and Physical Sciences Research Council (EPSRC).This is the final version of the article. It first appeared from Taylor & Francis via https://doi.org/10.3109/07388551.2016.114139

Integrative bacterial artificial chromosomes for DNA integration into the Bacillus subtilis chromosome.

Bacillus subtilis is a well-characterized model bacterium frequently used for a number of biotechnology and synthetic biology applications. Novel strategies combining the advantages of B. subtilis with the DNA assembly and editing tools of Escherichia coli are crucial for B. subtilis engineering efforts. We combined Gibson Assembly and λ red recombineering in E. coli with RecA-mediated homologous recombination in B. subtilis for bacterial artificial chromosome-mediated DNA integration into the well-characterized amyE target locus of the B. subtilis chromosome. The engineered integrative bacterial artificial chromosome iBAC(cav) can accept any DNA fragment for integration into B. subtilis chromosome and allows rapid selection of transformants by B. subtilis-specific antibiotic resistance and the yellow fluorescent protein (mVenus) expression. We used the developed iBAC(cav)-mediated system to integrate 10kb DNA fragment from E. coli K12 MG1655 into B. subtilis chromosome. iBAC(cav)-mediated chromosomal integration approach will facilitate rational design of synthetic biology applications in B. subtilis.M.J. and J.W.A are supported by EPSRC, OpenPlant Fund and SynBio Fund.This is the final version of the article. It first appeared from Elsevier via http://dx.doi.org/10.1016/j.mimet.2016.03.01

Computational cell model based on autonomous cell movement regulated by cell-cell signalling successfully recapitulates the "inside and outside" pattern of cell sorting

<p>Abstract</p> <p>Background</p> <p>Development of multicellular organisms proceeds from a single fertilized egg as the combined effect of countless numbers of cellular interactions among highly dynamic cells. Since at least a reminiscent pattern of morphogenesis can be recapitulated in a reproducible manner in reaggregation cultures of dissociated embryonic cells, which is known as cell sorting, the cells themselves must possess some autonomous cell behaviors that assure specific and reproducible self-organization. Understanding of this self-organized dynamics of heterogeneous cell population seems to require some novel approaches so that the approaches bridge a gap between molecular events and morphogenesis in developmental and cell biology. A conceptual cell model in a computer may answer that purpose. We constructed a dynamical cell model based on autonomous cell behaviors, including cell shape, growth, division, adhesion, transformation, and motility as well as cell-cell signaling. The model gives some insights about what cellular behaviors make an appropriate global pattern of the cell population.</p> <p>Results</p> <p>We applied the model to "inside and outside" pattern of cell-sorting, in which two different embryonic cell types within a randomly mixed aggregate are sorted so that one cell type tends to gather in the central region of the aggregate and the other cell type surrounds the first cell type. Our model can modify the above cell behaviors by varying parameters related to them. We explored various parameter sets with which the "inside and outside" pattern could be achieved. The simulation results suggested that direction of cell movement responding to its neighborhood and the cell's mobility are important for this specific rearrangement.</p> <p>Conclusion</p> <p>We constructed an <it>in silico </it>cell model that mimics autonomous cell behaviors and applied it to cell sorting, which is a simple and appropriate phenomenon exhibiting self-organization of cell population. The model could predict directional cell movement and its mobility are important in the "inside and outside" pattern of cell sorting. Those behaviors are altered by signal molecules and consequently affect the global pattern of the cell sorting. Our model is also applicable to other developmental processes beyond cell sorting.</p

Early Mingei and Development of Japanese Crafts 1920s-1940s

There has been considerable interest, both in and outside Japan, in the Mingei movement which began in the 1920s. As a result, its theory and history have been studied widely. Most studies, however, have treated the movement in isolation and as one which was conceived, initiated and developed by Yanagi Sdetsu (1889-1961). This thesis challenges the conventional view and argues that the movement had its roots in the development of modern craft in Japan which, in turn, had been influenced by modernist consciousness in art and literature. It does so by two methods: by setting the movement in the context of the modern development of craft and its appreciation, and by examining the contents of Kögei, the magazine which acted as the principal mouthpiece of the movement from 1931 to 1939. The thesis thus establishes: that in its early stage the Mingei movement included different ideas on craft while sharing an appreciation for getemono (ordinary craft wares); that although Yanagi played the central role in the movement, his so-called 'Mingei theory' was by no means unconditionally accepted by the other members: and that a change in the character of the movement, from appreciative to quasi-religious, was brought about not so much by Yanagi himself as by those who put their complete faith in Yanagi's theory. The thesis also argues that this change in the character of the movement did not affect the works of the craft artists of the Mingei movement? they produced their work like other modern Japanese craft artists of the same period, while supporting each other within the close membership

Mechanism of cardiac arrhythmias induced by epinephrine in dogs with hypokalemia

To investigate the mechanism of ventricular arrhythmias induced by epinephrine in dogs with hypokalemia, 30 adult mongrel dogs were separated into a control group (n = 13) and a hypokalemia group (n = 17). In the hypokalemia group, sodium polystyrene sulfonate (5 g/kg body weight) was infused into the colon. In both groups, the serum concentrations of sodium, potassium and calcium were measured every 15 minutes for 60 minutes. The mean ( ± standard deviation) serum potassium level of the hypokalemia group decreased significantly from 3.81 ± 0.21 to 2.92 ± 0.36 mEq/liter; there were no significant changes in other electrolytes. After 60 minutes, epinephrine (10 μg/kg) was injected intravenously in the hypokalemia and control groups, and the arrhythmia ratio (the number of ventricular ectopic beats divided by the total heart rate) was calculated for 5 minutes. Each group was further classified into subgroups of dogs with an arrhythmia ratio higher or lower than 10%. An arrhythmia ratio over 10% was observed in 7.7% of the control group and 53% of the hypokalemia group.Immediately after 5 minutes of epinephrine injection, myocardial mitochondria and plasma membrane fraction were prepared from each group. Mitochondrial calcium content and phospholipase activity of plasma membrane fraction were determined. Significant increases in both mitochondrial calcium content and phospholipase activity were observed in the dogs with hypokalemia and an arrhythmia ratio greater than 10%. In the hypokalemia group, there was a clear reciprocal correlation (r = − 0.79) between serum potassium concentration at 60 minutes and mitochondrial calcium content, and a clear correlation (r = 0.80) between mitochondrial calcium content and phospholipase activity. It was also demonstrated that the dogs with a higher than 10% arrhythmia ratio had a low serum potassium concentration, high mitochondrial calcium content and high phospholipase activity. These results suggest that hypokalemia enhances the calcium influx induced by epinephrine, resulting in activation of phospholipase, which is responsible for the development of ventricular arrhythmias

T7 RNA polymerase-driven inducible cell lysis for DNA transfer from Escherichia coli to Bacillus subtilis

The majority of the good DNA editing techniques have been developed in Escherichia coli; however, Bacillus subtilis is better host for a plethora of synthetic biology and biotechnology applications. Reliable and efficient systems for the transfer of synthetic DNA between E. coli and B. subtilis are therefore of the highest importance. Using synthetic biology approaches, such as streamlined lambda Red recombineering and Gibson Isothermal Assembly, we integrated genetic circuits pT7L123, Repr-ts-1 and pLT7pol encoding the lysis genes of bacteriophages MS2, ΦX174 and lambda, the thermosensitive repressor and the T7 RNA polymerase into the E. coli chromosome. In this system, T7 RNA polymerase regulated by the thermosensitive repressor drives the expression of the phage lysis genes. We showed that T7 RNA polymerase significantly increases efficiency of cell lysis and transfer of the plasmid and bacterial artificial chromosome-encoded DNA from the lysed E. coli into B. subtilis. The T7 RNA polymerase-driven inducible cell lysis system is suitable for the efficient cell lysis and transfer of the DNA engineered in E. coli to other naturally competent hosts, such as B. subtilis.This work was supported by the UK Engineering and Physical Sciences Research Council (EPSRC), OpenPlant Fund and SynBio Fund