Moderate oxygen depletion as a factor favouring the filamentous growth of Sphaerotilus natans

Low temperature annealing (<400°C) of YBa2Cu3O7x in a ozone containing oxygen atmosphere is sometimes carried out to oxygenate oxygen deficient thin films. Also, this technique can be used to fully oxygenate thinned TEM specimens when oxygen depletion in thin regions is suspected. However, the effects on the microstructure nor the extent of oxygenation of specimens has not been documented for specimens exposed to an ozone atmosphere. A particular concern is the fact that the ozone gas is so reactive and the oxygen diffusion rate at these temperatures is so slow that it may damage the specimen by an over-reaction. Thus we report here the results of an investigation on the microstructural effects of exposing a thinned YBa2Cu3O7-x specimen in an ozone atmosphere using transmission electron microscopy and energy loss spectroscopy techniques.

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Faculty Opinions recommendation of A steep phosphoinositide bis-phosphate gradient forms during fungal filamentous growth.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.717988257.793472562 ◽

2013 ◽

Author(s):

Matthew Sachs ◽

Xiaorong Lin

Keyword(s):

Filamentous Growth

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Investigation of the Contribution of Natural Organic Runoff to Dissolved Oxygen Depletion in the Red Deer River

Water Quality Research Journal ◽

10.2166/wqrj.1979.007 ◽

1979 ◽

Vol 14 (1) ◽

pp. 71-88

Author(s):

S.E. Penttinen ◽

P.H. Bouthillier ◽

S.E. Hrudey

Keyword(s):

Dissolved Oxygen ◽

Red Deer ◽

Stream Water ◽

Oxygen Demand ◽

Oxygen Depletion ◽

Experimental Program ◽

Nitrogen Budgets ◽

Carbon And Nitrogen ◽

Tributary Stream ◽

Small Tributary

Abstract Studies on the chronic low dissolved oxygen problems encountered under winter ice in the Red Deer River have generally been unable to account for dissolved oxygen depletion in terms of known manmade inputs. An experimental program was developed to assess the possible nature and approximate bounds of oxygen demand due to natural organic runoff carried to the Red Deer River by a small tributary stream, the Blindman River. The study employed an electrolytic respirometer on stream water samples subjected to prior concentration by vacuum evaporation. Evaluation of carbon and nitrogen budgets in conjunction with the measured oxygen demand indicate that biochemical oxygen demand is originating with natural organic runoff in tributaries of the Red Deer River. The results provide a basis for estimation of the possible contribution to the observed oxygen demand in the Red Deer River originating from natural organic runoff.

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Towards Control of an Estuary

Water Science & Technology ◽

10.2166/wst.1987.0077 ◽

1987 ◽

Vol 19 (9) ◽

pp. 155-174

Author(s):

Henk L. F. Saeijs

Keyword(s):

Shallow Water ◽

Storm Surge ◽

Salt Marshes ◽

Large Scale ◽

Western Europe ◽

Oxygen Depletion ◽

Negative Effects ◽

Intertidal Flats ◽

Environmental Consequences ◽

Short Time

The Delta Project is in its final stage. In 1974 it was subjected to political reconsideration, but it is scheduled now for completion in 1987. The final touches are being put to the storm-surge barrier and two compartment dams that divide the Oosterschelde into three areas: one tidal, one with reduced tide, and one a freshwater lake. Compartmentalization will result in 13% of channels, 45% of intertidal flats and 59% of salt marshes being lost. There is a net gain of 7% of shallow-water areas. Human interventions with large scale impacts are not new in the Oosterschelde but the large scale and short time in which these interventions are taking place are, as is the creation of a controlled tidal system. This article focusses on the area with reduced tide and compares resent day and expected characteristics. In this reduced tidal part salt marshes will extend by 30–70%; intertidal flats will erode to a lower level and at their edges, and the area of shallow water will increase by 47%. Biomass production on the intertidal flats will decrease, with consequences for crustaceans, fishes and birds. The maximum number of waders counted on one day and the number of ‘bird-days' will decrease drastically, with negative effects for the wader populations of western Europe. The net area with a hard substratum in the reduced tidal part has more than doubled. Channels will become shallower. Detritus import will not change significantly. Stratification and oxygen depletion will be rare and local. The operation of the storm-surge barrier and the closure strategy chosen are very important for the ecosystem. Two optional closure strategies can be followed without any additional environmental consequences. It was essential to determine a clearly defined plan of action for the whole area, and to make land-use choices from the outset. How this was done is briefly described.

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Filamentous growth of the budding yeast Saccharomyces cerevisiae induced by overexpression of the WHI2 gene

Microbiology ◽

10.1099/00221287-143-6-1867 ◽

1997 ◽

Vol 143 (6) ◽

pp. 1867-1876 ◽

Cited By ~ 16

Author(s):

P. A. Radcliffe ◽

K. M. Binley ◽

J. Trevethick ◽

M. Hall ◽

P. E. Sudbery

Keyword(s):

Saccharomyces Cerevisiae ◽

Budding Yeast ◽

Filamentous Growth ◽

Yeast Saccharomyces Cerevisiae

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TUP1, CPH1 and EFG1 Make Independent Contributions to Filamentation in Candida albicans

Genetics ◽

10.1093/genetics/155.1.57 ◽

2000 ◽

Vol 155 (1) ◽

pp. 57-67 ◽

Cited By ~ 4

Author(s):

Burkhard R Braun ◽

Alexander D Johnson

Keyword(s):

Candida Albicans ◽

Environmental Conditions ◽

Target Genes ◽

Single Cells ◽

Filamentous Growth ◽

Surface Proteins ◽

Pathway Expression ◽

Separate Pathway ◽

The Common ◽

Growth Pathway

Abstract The common fungal pathogen, Candida albicans, can grow either as single cells or as filaments (hyphae), depending on environmental conditions. Several transcriptional regulators have been identified as having key roles in controlling filamentous growth, including the products of the TUP1, CPH1, and EFG1 genes. We show, through a set of single, double, and triple mutants, that these genes act in an additive fashion to control filamentous growth, suggesting that each gene represents a separate pathway of control. We also show that environmentally induced filamentous growth can occur even in the absence of all three of these genes, providing evidence for a fourth regulatory pathway. Expression of a collection of structural genes associated with filamentous growth, including HYR1, ECE1, HWP1, ALS1, and CHS2, was monitored in strains lacking each combination of TUP1, EFG1, and CPH1. Different patterns of expression were observed among these target genes, supporting the hypothesis that these three regulatory proteins engage in a network of individual connections to downstream genes and arguing against a model whereby the target genes are regulated through a central filamentous growth pathway. The results suggest the existence of several distinct types of filamentous forms of C. albicans, each dependent on a particular set of environmental conditions and each expressing a unique set of surface proteins.

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Invasive Filamentous Growth ofCandida albicansIs Promoted by Czf1p-Dependent Relief of Efg1p-Mediated Repression

Genetics ◽

10.1093/genetics/160.4.1749 ◽

2002 ◽

Vol 160 (4) ◽

pp. 1749-1753 ◽

Cited By ~ 1

Author(s):

Angela D Giusani ◽

Marcelo Vinces ◽

Carol A Kumamoto

Keyword(s):

Candida Albicans ◽

Filamentous Growth ◽

Environmental Cues ◽

Complex Regulation

AbstractFilamentation of Candida albicans occurs in response to many environmental cues. During growth within matrix, Efg1p represses filamentation and Czf1p relieves this repression. We propose that Czf1p interacts with Efg1p, altering its function. The complex regulation of filamentation may reflect the versatility of C. albicans as a pathogen.

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Use of Amperometric and Potentiometric Probes in Scanning Electrochemical Microscopy for the Spatially-Resolved Monitoring of Severe Localized Corrosion Sites on Aluminum Alloy 2098-T351

Sensors ◽

10.3390/s21041132 ◽

2021 ◽

Vol 21 (4) ◽

pp. 1132 ◽

Cited By ~ 1

Author(s):

Rejane M. P. da Silva ◽

Javier Izquierdo ◽

Mariana X. Milagre ◽

Abenchara M. Betancor-Abreu ◽

Isolda Costa ◽

...

Keyword(s):

Scanning Electrochemical Microscopy ◽

Oxygen Depletion ◽

Localized Corrosion ◽

Alloy Surface ◽

Al Alloy ◽

Spatially Resolved ◽

Lower Oxygen ◽

Local Ph ◽

Electrochemical Microscopy

Amperometric and potentiometric probes were employed for the detection and characterization of reactive sites on the 2098-T351 Al-alloy (AA2098-T351) using scanning electrochemical microscopy (SECM). Firstly, the probe of concept was performed on a model Mg-Al galvanic pair system using SECM in the amperometric and potentiometric operation modes, in order to address the responsiveness of the probes for the characterization of this galvanic pair system. Next, these sensing probes were employed to characterize the 2098-T351 alloy surface immersed in a saline aqueous solution at ambient temperature. The distribution of reactive sites and the local pH changes associated with severe localized corrosion (SLC) on the alloy surface were imaged and subsequently studied. Higher hydrogen evolution, lower oxygen depletion and acidification occurred at the SLC sites developed on the 2098-T351 Al-alloy.

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Photocatalytic Activity Enhancement of Low-pressure Cold-Sprayed TiO2 Coatings Induced by Long-term Water Vapor Exposure

Journal of Thermal Spray Technology ◽

10.1007/s11666-021-01244-5 ◽

2021 ◽

Cited By ~ 1

Author(s):

Seremak Wioletta ◽

Baszczuk Agnieszka ◽

Jasiorski Marek ◽

Gibas Anna ◽

Winnicki Marcin

Keyword(s):

Titanium Dioxide ◽

Photocatalytic Activity ◽

Water Vapor ◽

Sol Gel ◽

Low Pressure ◽

Oxygen Depletion ◽

Amorphous Structure ◽

Industrial Applications ◽

Additional Parameter

AbstractThis work shows that the titanium dioxide coatings obtained by low-pressure cold gas spraying with the use of the sol–gel amorphous TiO2 powder are characterized by photocatalytic activity despite their partial amorphous content. Moreover, the research outcome suggests that the decomposition rate of organic pollutants is enhanced after long-term exposure to moisture. The condensation humidity test is not detrimental to the continuity and integrity of the coating, but the phase composition of coatings changes—with the exposure to water vapor, the portion of the amorphous phase crystallizes into brookite. The mechanism responsible for the conversion of amorphous TiO2 into brookite is attributed to the water-driven dissolution and reprecipitation of TiO6 octahedra. It has been shown that an additional parameter necessary for the stabilization of the brookite is the oxygen depletion of the amorphous structure of titanium dioxide. Considering the results presented in this paper and the advantages of a portable, low-pressure cold spray system for industrial applications, it is expected that TiO2 coatings produced from a sol–gel feedstock powder can be further developed and tested as efficient photocatalysts.

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The first sequenced Sphaerotilus natans bacteriophage– characterization and potential to control its filamentous bacterium host

FEMS Microbiology Ecology ◽

10.1093/femsec/fiab029 ◽

2021 ◽

Vol 97 (4) ◽

Author(s):

Rute Ferreira ◽

Rui Amado ◽

Jorge Padrão ◽

Vânia Ferreira ◽

Nicolina M Dias ◽

...

Keyword(s):

Wastewater Treatment ◽

Bacterial Communities ◽

Potential Application ◽

Deleterious Effect ◽

Wastewater Treatment Plants ◽

Lytic Phage ◽

Filamentous Bacterium ◽

Sphaerotilus Natans ◽

Isolation And Characterization

ABSTRACT Bacteriophages (phages) are ubiquitous entities present in every conceivable habitat as a result of their bacterial parasitism. Their prevalence and impact in the ecology of bacterial communities and their ability to control pathogens make their characterization essential, particularly of new phages, improving knowledge and potential application. The isolation and characterization of a new lytic phage against Sphaerotilus natans strain DSM 6575, named vB_SnaP-R1 (SnaR1), is here described. Besides being the first sequenced genome of a Sphaerotilus natans infecting phage, 99% of its 41507 bp genome lacks homology with any other sequenced phage, revealing its uniqueness and previous lack of knowledge. Moreover, SnaR1 is the first Podoviridae phage described infecting this bacterium. Sphaerotilus natans is an important filamentous bacterium due to its deleterious effect on wastewater treatment plants (WWTP) and thus, phages may play a role as novel biotechnological tools against filamentous overgrowth in WWTP. The lytic spectrum of SnaR1 was restricted to its host strain, infecting only one out of three S. natans strains and infection assays revealed its ability to reduce bacterial loads. Results suggest SnaR1 as the prototype of a new phage genus and demonstrates its potential as a non-chemical alternative to reduce S. natans DSM 6575 cells.

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