scholarly journals Selection of Unusual Actinomycetal Primary σ70 Factors by Plant-Colonizing Frankia Strains

2004 ◽  
Vol 70 (2) ◽  
pp. 991-998 ◽  
Author(s):  
Céline Lavire ◽  
Didier Blaha ◽  
Benoit Cournoyer
Keyword(s):  
Growth Conditions ◽  
Infection Process ◽  
The Other ◽  
Gene Library ◽  
Pcr Screening ◽  
Liquid Cultures ◽  
Total Dna ◽  
Root Hair Infection ◽  
Selection Of

ABSTRACT Functional adaptations of σ70 transcriptional factors led to the emergence of several paralogous lineages, each one being specialized for gene transcription under particular growth conditions. Screening of a Frankia strain EaI-12 gene library by σ70 DNA probing allowed the detection and characterization of a novel actinomycetal primary (housekeeping) σ70 factor. Phylogenetic analysis positioned this factor in the RpoD cluster of proteobacterial and low-G+C-content gram-positive factors, a cluster previously free of any actinobacterial sequences. σ70 DNA probing of Frankia total DNA blots and PCR screening detected one or two rpoD-like DNA regions per species. rpoD matched the conserved region in all of the species tested. The other region was found to contain sigA, an alternative primary factor. sigA appeared to be strictly distributed among Frankia species infecting plants by the root hair infection process. Both genes were transcribed by Frankia strain ACN14a grown in liquid cultures. The molecular phylogeny of the σ70 family determined with Frankia sequences showed that the alternative actinomycetal factors and the essential ones belonged to the same radiation. At least seven distinct paralogous lineages were observed among this radiation, and gene transfers were detected in the HrdB actinomycetal lineage.

scholarly journals Initiation of Biofilm Formation byPseudomonas aeruginosa 57RP Correlates with Emergence of Hyperpiliated and Highly Adherent Phenotypic Variants Deficient in Swimming, Swarming, and Twitching Motilities

2001 ◽  
Vol 183 (4) ◽  
pp. 1195-1204 ◽  
Author(s):  
Eric Déziel ◽  
Yves Comeau ◽  
Richard Villemur
Keyword(s):  
Environmental Conditions ◽  
Phase Variation ◽  
Growth Conditions ◽  
Phenotypic Traits ◽  
Liquid Cultures ◽  
Environmental Bacterium ◽  
Type Iv ◽  
Large Colony ◽  
Small Colony

ABSTRACT Pseudomonas aeruginosa is a ubiquitous environmental bacterium capable of forming biofilms on surfaces as a survival strategy. It exhibits a large variety of competition/virulence factors, such as three types of motilities: flagellum-mediated swimming, flagellum-mediated swarming, and type IV pilus-mediated twitching. A strategy frequently used by bacteria to survive changing environmental conditions is to create a phenotypically heterogeneous population by a mechanism called phase variation. In this report, we describe the characterization of phenotypic variants forming small, rough colonies that spontaneously emerged when P. aeruginosa 57RP was cultivated as a biofilm or in static liquid cultures. These small-colony (S) variants produced abundant type IV fimbriae, displayed defective swimming, swarming, and twitching motilities, and were impaired in chemotaxis. They also autoaggregated in liquid cultures and rapidly initiated the formation of strongly adherent biofilms. In contrast, the large-colony variant (parent form) was poorly adherent, homogeneously dispersed in liquid cultures, and produced scant polar fimbriae. Further analysis of the S variants demonstrated differences in a variety of other phenotypic traits, including increased production of pyocyanin and pyoverdine and reduced elastase activity. Under appropriate growth conditions, cells of each phenotype switched to the other phenotype at a fairly high frequency. We conclude that these S variants resulted from phase variation and were selectively enriched when P. aeruginosa 57RP was grown as a biofilm or in static liquid cultures. We propose that phase variation ensures the prior presence of phenotypic forms well adapted to initiate the formation of a biofilm as soon as environmental conditions are favorable.

scholarly journals Development and Characterization of Cornstarch-Based Bioplastics Packaging Film Using a Combination of Different Plasticizers

Polymers ◽  
2021 ◽  
Vol 13 (20) ◽  
pp. 3487
Author(s):  
Walid Abotbina ◽  
S. M. Sapuan ◽  
M. T. H. Sultan ◽  
M. F. M. Alkbir ◽  
R. A. Ilyas
Keyword(s):  
Tensile Strength ◽  
Moisture Content ◽  
Water Absorption ◽  
Food Packaging ◽  
The Other ◽  
Packaging Film ◽  
Film Properties ◽  
Selection Of

This work aims to develop cornstarch (CS) based films using fructose (F), glycerol (G), and their combination (FG) as plasticizers with different ratios for food packaging applications. The findings showed that F-plasticized film had the lowest moisture content, highest crystallinity among all films, and exhibited the highest tensile strength and thermostability. In contrast, G-plasticized films showed the lowest density and water absorption with less crystallinity compared to the control and the other plasticized film. In addition, SEM results indicated that FG-plasticized films had a relatively smoother and more coherent surface among the tested films. The findings have also shown that varying the concentration of the plasticizers significantly affected the different properties of the plasticized films. Therefore, the selection of a suitable plasticizer at an appropriate concentration may significantly optimize film properties to promote the utilization of CS films for food packaging applications.

scholarly journals INTERNATIONAL STANDARDS FOR THE FORMATION OF THE CORPS OF JUDGES AS THE BASIS OF IMPROVING THE GUARANTEES OF INDEPENDENCE OF THE COURT AND JUDGES

2020 ◽  
pp. 52-56
Author(s):  
P. V. Horinov
Keyword(s):  
International Standards ◽  
The Other ◽  
Court Cases ◽  
General Characterization ◽  
Administrative Procedures ◽  
The Subject ◽  
The Law ◽  
Selection Of

The article is devoted to the general characterization of the international standards for the formation of the corps of judges and the corresponding administrative procedures as a basis for improving the guarantees of independence of the court and judges, to determine on this basis the key ways of introducing these standards into the domestic system of legislation in order to resolve specific and specific other issues. It is substantiated that it is expedient to organize the international standards of formation of the corps of judges in the context of guaranteeing the independence of the court and judges according to the criterion of the object of their influence. According to this criterion, standards were identified concerning: recruitment of judges; staffing the subject of appointment of judges to positions; training of judges; guarantees during the service. In the course of the study, it was determined that in order to specify the notion of substantial disciplinary misconduct as a circumstance, which makes it impossible to appoint a judge, it is advisable to amend the Law «Оn the Judiciary and Status of Judges»: to supplement part 4 of Article 69 with paragraph 2, in which to specify the notion of substantial discipline misdemeanor as a circumstance, which makes it impossible to appoint a judge; amend Article 69, paragraph 4, after the words «for committing a material disciplinary offense» by the words «except as provided in the second paragraph of this paragraph». There are two ways to implement international standards in the work of the judiciary on the formation of a corps ofjudges. The first is the transfer of some of the powers of the High Qualifications Commission of Judges of Ukraine (including the selection of judges to the post) to the competence of the High Council of Justice. In the other part of its authority, the High Qualifications Commission of Judges of Ukraine must remain in charge of the judicial self-government bodies. The second is the complete retention of the relevant powers under the High Qualifications Commission of Judges of Ukraine, leaving the issue of the formation of the High Qualifications Commission of Judges of Ukraine within the jurisdiction of judicial self-governing bodies. The first way is recommended. In the course of the research, it was determined that guarantees of independence of the judiciary are purely practical categories. Actually enshrining them in the legislation will not guarantee the independence of the judicial branch of power, and in particular − the independence of judges in the resolution of court cases. Such guarantees only work if they are actually secured.

scholarly journals TIME OF RECOMBINATION IN THE DROSOPHILA MELANOGASTER OOCYTE. III. SELECTION AND CHARACTERIZATION OF TEMPERATURE-SENSITIVE AND -INSENSITIVE, RECOMBINATION-DEFICIENT ALLELES IN DROSOPHILA

Genetics ◽  
1984 ◽  
Vol 108 (2) ◽  
pp. 425-443
Author(s):  
R F Grell
Keyword(s):  
Gene Dosage ◽  
Temperature Response ◽  
Sharp Decrease ◽  
The Other ◽  
Temperature Sensitive ◽  
Response Curves ◽  
Chromosome Arm ◽  
Complex Locus ◽  
Selection Of

ABSTRACT The procedure for the selection of a temperature-sensitive recombination mutant in Drosophila is described. Use of this procedure has led to the recovery of three alleles at a new recombination locus called rec-1, located within the region of chromosome 3 circumscribed by Deficiency(3R)sbd  105. One allele, rec-1  26, is temperature sensitive, and the other two alleles, rec-1  6 and rec-1  16, are temperature insensitive. Gene dosage studies reveal rec-1  26 to be a leaky mutant with greater recombination activity in two doses than in one. The other two alleles show no dose response, implying that they may be null mutants. The temperature response curves of rec-1  26 as a homozygote and in heteroallelic combination with rec-1  16 suggest that the sharp decrease in recombination between 28° and 31° indicates temperature denaturation of an enzyme or other protein specified by the mutant and associated with the recombination process. The ability of small changes in temperature to reverse or abolish polarity in recombination along the X chromosome arm in rec-1  26/rec-1  16 females brings into question the use of the "polarity" criterion to partition mutants into two functional types, i.e., precondition mutants that display polarity and exchange mutants that do not. Evidence that rec-1 may be part of a complex locus residing in a chromosome segment harboring a variety of recombination-related genes is presented.

Note on Selection of Coordinate Systems for Geodynamics

1975 ◽  
Vol 26 ◽  
pp. 395-407
Author(s):  
S. Henriksen
Keyword(s):  
Sea Level ◽  
The Other ◽  
Coordinate Systems ◽  
Mean Sea Level ◽  
The Earth ◽  
The One ◽  
Static Systems ◽  
Selection Of

The first question to be answered, in seeking coordinate systems for geodynamics, is: what is geodynamics? The answer is, of course, that geodynamics is that part of geophysics which is concerned with movements of the Earth, as opposed to geostatics which is the physics of the stationary Earth. But as far as we know, there is no stationary Earth – epur sic monere. So geodynamics is actually coextensive with geophysics, and coordinate systems suitable for the one should be suitable for the other. At the present time, there are not many coordinate systems, if any, that can be identified with a static Earth. Certainly the only coordinate of aeronomic (atmospheric) interest is the height, and this is usually either as geodynamic height or as pressure. In oceanology, the most important coordinate is depth, and this, like heights in the atmosphere, is expressed as metric depth from mean sea level, as geodynamic depth, or as pressure. Only for the earth do we find “static” systems in use, ana even here there is real question as to whether the systems are dynamic or static. So it would seem that our answer to the question, of what kind, of coordinate systems are we seeking, must be that we are looking for the same systems as are used in geophysics, and these systems are dynamic in nature already – that is, their definition involvestime.

Infection of Escherichia coli with bacteriophages

1969 ◽  
Vol 27 ◽  
pp. 370-371
Author(s):  
Manfred E. Bayer
Keyword(s):  
Escherichia Coli ◽  
Nucleic Acid ◽  
Cell Surface ◽  
Virus Type ◽  
Infection Process ◽  
Adsorption Site ◽  
The Other ◽  
Specific Receptors ◽  
Bacterial Receptors

The first step in the infection of a bacterium by a virus consists of a collision between cell and bacteriophage. The presence of virus-specific receptors on the cell surface will trigger a number of events leading eventually to release of the phage nucleic acid. The execution of the various "steps" in the infection process varies from one virus-type to the other, depending on the anatomy of the virus. Small viruses like ØX 174 and MS2 adsorb directly with their capsid to the bacterial receptors, while other phages possess attachment organelles of varying complexity. In bacteriophages T3 (Fig. 1) and T7 the small conical processes of their heads point toward the adsorption site; a welldefined baseplate is attached to the head of P22; heads without baseplates are not infective.

A very rapid in situ Kikuchi technique to determine relative crystal misorientation

1988 ◽  
Vol 46 ◽  
pp. 830-831
Author(s):  
J. I. Bennetch
Keyword(s):  
Electron Beam ◽  
Analytical Techniques ◽  
Superplastic Forming ◽  
The Other ◽  
Kikuchi Pattern ◽  
Kikuchi Line ◽  
Line Analysis

In a recent study of the superplastic forming (SPF) behavior of certain Al-Li-X alloys, the relative misorientation between adjacent (sub)grains proved to be an important parameter. It is well established that the most accurate way to determine misorientation across boundaries is by Kikuchi line analysis. However, the SPF study required the characterization of a large number of (sub)grains in each sample to be statistically meaningful, a very time-consuming task even for comparatively rapid Kikuchi analytical techniques.In order to circumvent this problem, an alternate, even more rapid in-situ Kikuchi technique was devised, eliminating the need for the developing of negatives and any subsequent measurements on photographic plates. All that is required is a double tilt low backlash goniometer capable of tilting ± 45° in one axis and ± 30° in the other axis. The procedure is as follows. While viewing the microscope screen, one merely tilts the specimen until a standard recognizable reference Kikuchi pattern is centered, making sure, at the same time, that the focused electron beam remains on the (sub)grain in question.

Applications of Transmission Electron Microscopy in the Characterization of Metal Machinability

1968 ◽  
Vol 26 ◽  
pp. 442-443 ◽  
Author(s):  
L.E. Murr ◽  
A.B. Draper
Keyword(s):  
Electron Microscopy ◽  
State Physics ◽  
Test Material ◽  
Milling Machine ◽  
Rotary Table ◽  
Solid State Physics ◽  
Materials Properties ◽  
Transmission Electron ◽  
Selection Of

The industrial characterization of the machinability of metals and alloys has always been a very arbitrarily defined property, subject to the selection of various reference or test materials; and the adoption of rather naive and misleading interpretations and standards. However, it seems reasonable to assume that with the present state of knowledge of materials properties, and the current theories of solid state physics, more basic guidelines for machinability characterization might be established on the basis of the residual machined microstructures. This approach was originally pursued by Draper; and our presentation here will simply reflect an exposition and extension of this research.The technique consists initially in the production of machined chips of a desired test material on a horizontal milling machine with the workpiece (specimen) mounted on a rotary table vice. A single cut of a specified depth is taken from the workpiece (0.25 in. wide) each at a new tool location.

Rapid Isolation of High Molecular Weight Urokinase from Native Human Urine

1982 ◽  
Vol 47 (03) ◽  
pp. 197-202 ◽  
Author(s):  
Kurt Huber ◽  
Johannes Kirchheimer ◽  
Bernd R Binder
Keyword(s):  
Molecular Weight ◽  
High Molecular Weight ◽  
Human Urine ◽  
Gel Filtration ◽  
Chain Structure ◽  
The Other ◽  
Single Chain ◽  
Apparent Homogeneity ◽  
Sequential Adsorption

SummaryUrokinase (UK) could be purified to apparent homogeneity starting from crude urine by sequential adsorption and elution of the enzyme to gelatine-Sepharose and agmatine-Sepharose followed by gel filtration on Sephadex G-150. The purified product exhibited characteristics of the high molecular weight urokinase (HMW-UK) but did contain two distinct entities, one of which exhibited a two chain structure as reported for the HMW-UK while the other one exhibited an apparent single chain structure. The purification described is rapid and simple and results in an enzyme with probably no major alterations. Yields are high enough to obtain purified enzymes for characterization of UK from individual donors.

INTERFERENSI GRAMATIKAL DALAM KUMPULAN CERPEN BIARKAN AKU MEMULAI KARYA NURUL F. HUDA

2019 ◽  
Vol 1 (01) ◽  
pp. 16-23
Author(s):  
Zimmatul Liviana
Keyword(s):  
Short Stories ◽  
Data Collection ◽  
Qualitative Method ◽  
Language Variation ◽  
The Other ◽  
Qualitative Descriptive ◽  
Ofthe Object ◽  
Selection Of ◽  
Descriptive Qualitative

The research grammatical interference in a collection ofshort stories Biarkan Aku Memula iwork Nurul F. Hudaisa collection ofshort storiesset in the back that Is start work Let Nurul F. Huda contains many grammatical interference.The problem of this   study were(1)how   the various morphologi calinterference containedin   a   collection of short stories Biarkan Aku Memulai work Nurul F. Huda. (2)how the various syntactic interference contained in a collection of short stories Biarkan Aku Memulai work Nurul F. Huda. The purposeof this studyis to describe the morphological and         Syntactic interference contained in a collection of short stories Biarkan Aku Memulai work Nurul F. Huda. Sociolinguistics is the study of language variation and use in society. Interference is the event of the use of language elements of one into the other language elements that occur in the speakers themselves. This research uses descriptive qualitative method because to describe the actual realityin order to obtainan accurateand objective. Qualitative descriptive methods were used to analyzethe elements ofa word orphrase that incorporated elements of other languages with the analysis and description of the formulation of the problem is the answer. Data collection techniques using observation techniques, the determination ofthe object of research, the selection of short stories.Based on the analysis of the data in this study can be found that there are six forms of interference morphology, namely (1) the prefix nasal N-sound, (2) the addition of the suffix, (3) the exchange prefix, (4) exchange suffixes, (5) exchange konfiks, (6) removal affixes. While the syntactic interference only on the words and phrases in a sentence. The results of the study it can be concluded that the interference morphology more common than syntactic interference.

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