Aerobically respiring prokaryotic strains exhibit a broader temperature–pH–salinity space for cell division than anaerobically respiring and fermentative strains

Biological processes on the Earth operate within a parameter space that is constrained by physical and chemical extremes. Aerobic respiration can result in adenosine triphosphate yields up to over an order of magnitude higher than those attained anaerobically and, under certain conditions, may enable microbial multiplication over a broader range of extremes than other modes of catabolism. We employed growth data published for 241 prokaryotic strains to compare temperature, pH and salinity values for cell division between aerobically and anaerobically metabolizing taxa. Isolates employing oxygen as the terminal electron acceptor exhibited a considerably more extensive three-dimensional phase space for cell division (90% of the total volume) than taxa using other inorganic substrates or organic compounds as the electron acceptor (15% and 28% of the total volume, respectively), with all groups differing in their growth characteristics. Understanding the mechanistic basis of these differences will require integration of research into microbial ecology, physiology and energetics, with a focus on global-scale processes. Critical knowledge gaps include the combined impacts of diverse stress parameters on Gibbs energy yields and rates of microbial activity, interactions between cellular energetics and adaptations to extremes, and relating laboratory-based data to in situ limits for cell division.

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The H+/e Ratio in Chloroplasts is 2. Possible Errors in its Determination

Zeitschrift für Naturforschung C ◽

10.1515/znc-1977-9-1025 ◽

1977 ◽

Vol 32 (9-10) ◽

pp. 810-816 ◽

Cited By ~ 33

Author(s):

Satham Saphon ◽

Antony R. Crofts

Keyword(s):

Water Splitting ◽

Electron Acceptor ◽

Buffering Capacity ◽

Large Concentration ◽

Ph Indicator ◽

Terminal Electron Acceptor ◽

Sources Of Error ◽

Absorbance Change ◽

Order Of Magnitude ◽

Indicator Dye

Abstract Chloroplasts H+/e Ratio, Buffering Capacities The number of H+ released inside the chloroplast thylakoids per electron flowing to the terminal electron acceptor (the H+/e ratio) has been investigated using a pH indicator dye technique. The apparent H+/e ratio was measured by comparing the absorbance change due to H+-uptake outside the thylakoids in the absence of uncoupling agent, and the absorbance change due to the net H+-production associated with water-splitting after addition of uncoupling agent in the presence of ferricyanide.(1) The apparent H+/e ratio was found to be higher than 2, using methylamine as uncoupling agent (> 1 mм). It varied with the concentrations of added buffer.(2) The apparent H+/e ratio obtained with methylamine as uncoupling agent (with or without additional buffer) approached the value of 2 with decreasing concentrations of methylamine.(3) A consistent H+/e ratio of 2 was also obtained with gramicidin or the nigericin-type ionophore dianemycin over a relatively large concentration range, and did not vary with addition of extra buffer.(4) The buffering capacity of the chloroplast suspension was estimated and was found to be the same order of magnitude as that of methylamine at the concentrations used.We suggest that the high H+/e ratios reported 423, 510-523 [1976]) reflect a failure to take account of the change in buffering capacity of the chloroplast suspension on adding uncoupling concentrations of methyl amine. Other possible sources of error in the estimation of H+/e ratio by different techniques are also discussed.

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Detection, Averaging, and 3D Reconstruction of Biological Specimens on Hypercubes (Transputer-based) Computers

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100181026 ◽

1990 ◽

Vol 48 (1) ◽

pp. 454-455

Author(s):

Jose-Maria Carazo ◽

I. Benavides ◽

S. Marco ◽

J.L. Carrascosa ◽

E.L. Zapata

Keyword(s):

3D Reconstruction ◽

3D Structure ◽

Three Dimensional ◽

Software Tools ◽

Mapping Method ◽

Computer Architectures ◽

Parallel Computer ◽

Reconstruction Process ◽

Computing Power ◽

Order Of Magnitude

Obtaining the three-dimensional (3D) structure of negatively stained biological specimens at a resolution of, typically, 2 - 4 nm is becoming a relatively common practice in an increasing number of laboratories. A combination of new conceptual approaches, new software tools, and faster computers have made this situation possible. However, all these 3D reconstruction processes are quite computer intensive, and the middle term future is full of suggestions entailing an even greater need of computing power. Up to now all published 3D reconstructions in this field have been performed on conventional (sequential) computers, but it is a fact that new parallel computer architectures represent the potential of order-of-magnitude increases in computing power and should, therefore, be considered for their possible application in the most computing intensive tasks.We have studied both shared-memory-based computer architectures, like the BBN Butterfly, and local-memory-based architectures, mainly hypercubes implemented on transputers, where we have used the algorithmic mapping method proposed by Zapata el at. In this work we have developed the basic software tools needed to obtain a 3D reconstruction from non-crystalline specimens (“single particles”) using the so-called Random Conical Tilt Series Method. We start from a pair of images presenting the same field, first tilted (by ≃55°) and then untilted. It is then assumed that we can supply the system with the image of the particle we are looking for (ideally, a 2D average from a previous study) and with a matrix describing the geometrical relationships between the tilted and untilted fields (this step is now accomplished by interactively marking a few pairs of corresponding features in the two fields). From here on the 3D reconstruction process may be run automatically.

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Scanning-tunneling spectroscopy on conjugated polymer films

MRS Proceedings ◽

10.1557/proc-771-l4.3 ◽

2003 ◽

Vol 771 ◽

Author(s):

M. Kemerink ◽

S.F. Alvarado ◽

P.M. Koenraad ◽

R.A.J. Janssen ◽

H.W.M. Salemink ◽

...

Keyword(s):

Polymer Films ◽

Conjugated Polymer ◽

Three Dimensional ◽

Field Enhancement ◽

Direct Consequence ◽

Scanning Tunneling Spectroscopy ◽

Tunneling Spectroscopy ◽

Band Alignment ◽

Scanning Tunneling ◽

Order Of Magnitude

AbstractScanning-tunneling spectroscopy experiments have been performed on conjugated polymer films and have been compared to a three-dimensional numerical model for charge injection and transport. It is found that field enhancement near the tip apex leads to significant changes in the injected current, which can amount to more than an order of magnitude, and can even change the polarity of the dominant charge carrier. As a direct consequence, the single-particle band gap and band alignment of the organic material can be directly obtained from tip height-voltage (z-V) curves, provided that the tip has a sufficiently sharp apex.

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Faculty Opinions recommendation of Melanin production and use as a soluble electron shuttle for Fe(III) oxide reduction and as a terminal electron acceptor by Shewanella algae BrY.

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

10.3410/f.1005984.72955 ◽

2002 ◽

Author(s):

John Coates

Keyword(s):

Electron Acceptor ◽

Electron Shuttle ◽

Oxide Reduction ◽

Melanin Production ◽

Terminal Electron Acceptor ◽

Shewanella Algae

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Faculty Opinions recommendation of Three-Dimensional Superresolution Imaging of the FtsZ Ring during Cell Division of the Cyanobacterium Prochlorococcus.

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

10.3410/f.732146604.793542893 ◽

2018 ◽

Author(s):

William Margolin

Keyword(s):

Cell Division ◽

Three Dimensional ◽

Superresolution Imaging ◽

Ftsz Ring

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Origin and Application of the Twinned Calcite Strain Gauge

Geosciences ◽

10.3390/geosciences11070296 ◽

2021 ◽

Vol 11 (7) ◽

pp. 296

Author(s):

Richard H. Groshong

Keyword(s):

Stress Analysis ◽

Strain Gauge ◽

Strain Tensor ◽

Three Dimensional ◽

Constant Strain Rate ◽

Axis Orientation ◽

Order Of Magnitude ◽

Rate Experiment ◽

Strain Axis ◽

Expected Values

This paper is a personal account of the origin and development of the twinned-calcite strain gauge, its experimental verification, and its relationship to stress analysis. The method allows the calculation of the three-dimensional deviatoric strain tensor based on five or more twin sets. A minimum of about 25 twin sets should provide a reasonably accurate result for the magnitude and orientation of the strain tensor. The opposite-signed strain axis orientation is the most accurately located. Where one strain axis is appreciably different from the other two, that axis is generally within about 10° of the correct value. Experiments confirm a magnitude accuracy of 1% strain over the range of 1–12% axial shortening and that samples with more than 40% negative expected values imply multiple or rotational deformations. If two deformations are at a high angle to one another, the strain calculated from the positive and negative expected values separately provides a good estimate of both deformations. Most stress analysis techniques do not provide useful magnitudes, although most provide a good estimate of the principal strain axis directions. Stress analysis based on the number of twin sets per grain provides a better than order-of-magnitude approximation to the differential stress magnitude in a constant strain rate experiment.

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Small footprint optoelectrodes using ring resonators for passive light localization

Microsystems & Nanoengineering ◽

10.1038/s41378-021-00263-0 ◽

2021 ◽

Vol 7 (1) ◽

Author(s):

Vittorino Lanzio ◽

Gregory Telian ◽

Alexander Koshelev ◽

Paolo Micheletti ◽

Gianni Presti ◽

...

Keyword(s):

State Of The Art ◽

Three Dimensional ◽

Network Activity ◽

Ring Resonators ◽

Spatiotemporal Resolution ◽

Optical Ring Resonators ◽

Light Localization ◽

Order Of Magnitude ◽

Small Footprint

AbstractThe combination of electrophysiology and optogenetics enables the exploration of how the brain operates down to a single neuron and its network activity. Neural probes are in vivo invasive devices that integrate sensors and stimulation sites to record and manipulate neuronal activity with high spatiotemporal resolution. State-of-the-art probes are limited by tradeoffs involving their lateral dimension, number of sensors, and ability to access independent stimulation sites. Here, we realize a highly scalable probe that features three-dimensional integration of small-footprint arrays of sensors and nanophotonic circuits to scale the density of sensors per cross-section by one order of magnitude with respect to state-of-the-art devices. For the first time, we overcome the spatial limit of the nanophotonic circuit by coupling only one waveguide to numerous optical ring resonators as passive nanophotonic switches. With this strategy, we achieve accurate on-demand light localization while avoiding spatially demanding bundles of waveguides and demonstrate the feasibility with a proof-of-concept device and its scalability towards high-resolution and low-damage neural optoelectrodes.

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