The elemental composition of bacteria: A signature of growth conditions?

1996 ◽  
Vol 33 (1-6) ◽  
pp. 3-9 ◽  
Author(s):  
Mikal Heldal ◽  
Svein Norland ◽  
Kjell Magne Fagerbakke ◽  
Frede Thingstad ◽  
Gunnar Bratbak
Keyword(s):  
Elemental Composition ◽  
Growth Conditions

scholarly journals Variability in Elemental Composition of Conifer Tree Rings

2021 ◽  
pp. 24-37
Author(s):  
Vladimir L. Gavrikov ◽  
◽  
Alexey I. Fertikov ◽  
Evgenii A. Vaganov ◽  
Keyword(s):  
Elemental Composition ◽  
Tree Rings ◽  
Chemical Elements ◽  
Dimensional Space ◽  
Siberian Larch ◽  
Growth Conditions ◽  
Pinus Sibirica ◽  
Siberian Spruce ◽  
Long Term Experiment ◽  
Conifer Tree

Distribution of chemical elements in tree rings bears important information on various biogeochemical processes. In order to achieve a reliable interpretation of the information, it is necessary to know the degree of variation in the content of chemical elements both at the level of the entire species and at the level of individual trees. The research aims to determine which chemical elements have a stable distribution in the trunks of a number of conifers: Siberian spruce (Picea obovata Ledeb.), Scots pine (Pinus sylvestris L.), Siberian larch (Larix sibirica Ledeb.), and Siberian pine (Pinus sibirica Du Tour). The data for the analysis were obtained on the basis of the long-term experiment in forest growing. The experimental site was laid out in 1971–1972 in the vicinity of Krasnoyarsk by the staff of the Sukachev Institute of Forest of the Siberian Branch of the Russian Academy of Sciences. Before planting the seedlings, the soil ground was mechanically levelled, and thus, sufficiently equal growth conditions were created for all plantings. Cores with a diameter of 12 mm were sampled from three normally developing trees of each species and analyzed using modern X-ray fluorescence methods. Content relative values of elements (counts) were obtained with the Itrax Multiscanner (COX Analytical Systems). The content of elements in the tree rings was characterized by the concentration and reserve of elements. Concentration was calculated as the number of counts per 1 mm2 of the ring area; reserve was calculated as the number of counts over the entire ring area. Each of these variables was defined by the parameters of linear slope in the calendar year series and the standard deviation. The cluster analysis was performed in the 4-dimensional space of the obtained parameters. This allowed determining whether the series of element distributions from different trees and species are grouped. Three elements (Ca, Co, and P) show high stability of distribution parameters in tree rings with no regard to tree species. A number of other elements (Mn, Pb, Cl, Cr, Ni, Sr, and W) are stably grouped depending on the species. The results of the research enable to focus on the study of the elements stably distributed in the conifer trunks. For citation: Gavrikov V.L., Fertikov A.I., Sharafutdinov R.A., Vaganov E.A. Variability in Elemental Composition of Conifer Tree Rings. Lesnoy Zhurnal [Russian Forestry Journal], 2021, no. 6, pp. 24–37. DOI: 10.37482/0536-1036-2021-6-24-37

scholarly journals Variation among species in proteomic sulphur content is related to environmental conditions

2006 ◽  
Vol 273 (1591) ◽  
pp. 1293-1300 ◽  
Author(s):  
Jason G Bragg ◽  
Dominique Thomas ◽  
Peggy Baudouin-Cornu
Keyword(s):  
Elemental Composition ◽  
Environmental Conditions ◽  
Base Composition ◽  
Growth Conditions ◽  
Sulphur Content ◽  
Methionine Residues ◽  
Living Organisms

The elemental composition of proteins influences the quantities of different elements required by organisms. Here, we considered variation in the sulphur content of whole proteomes among 19 Archaea, 122 Eubacteria and 10 eukaryotes whose genomes have been fully sequenced. We found that different species vary greatly in the sulphur content of their proteins, and that average sulphur content of proteomes and genome base composition are related. Forces contributing to variation in proteomic sulphur content appear to operate quite uniformly across the proteins of different species. In particular, the sulphur content of orthologous proteins was frequently correlated with mean proteomic sulphur contents. Among prokaryotes, proteomic sulphur content tended to be greater in anaerobes, relative to non-anaerobes. Thermophiles tended to have lower proteomic sulphur content than non-thermophiles, consistent with the thermolability of cysteine and methionine residues. This work suggests that persistent environmental growth conditions can influence the evolution of elemental composition of whole proteomes in a manner that may have important implications for the amount of sulphur used by living organisms to build proteins. It extends previous studies that demonstrated links between transient changes in environmental conditions and the elemental composition of subsets of proteins expressed under these conditions.

scholarly journals Strongly confined localized surface plasmon resonance (LSPR) bands of Pt, AgPt, AgAuPt nanoparticles

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Mao Sui ◽  
Sundar Kunwar ◽  
Puran Pandey ◽  
Jihoon Lee
Keyword(s):  
Surface Plasmon Resonance ◽  
Surface Morphology ◽  
Elemental Composition ◽  
Surface Plasmon ◽  
Plasmon Resonance ◽  
Localized Surface Plasmon Resonance ◽  
Growth Conditions ◽  
Localized Surface Plasmon ◽  
Resonance Modes ◽  
Tunable Range

Abstract Multi-metallic alloy nanoparticles (NPs) can enable the advanced applications in the energy, biology, electronics, optics and catalysis due to their multi-functionality, wide tunable range and electronic heterogeneity. In this work, various mono-, bi- and tri-metallic nanostructures composed of Ag, Au and Pt are demonstrated on transparent c-plane sapphire (0001) substrates and the corresponding morphological and optical characteristics are thoroughly investigated. The resulting Pt and AuPt NPs in this study demonstrate much enhanced LSPR responses as compared to the pure Pt NPs from the previous studies, which was contributed by the synergistic effect of Au and Pt and improved surface morphology. These results are sharply distinct in terms of surface morphology and elemental variability from those obtained by the dewetting of monometallic Ag, Au and Pt films under the similar growth conditions, which is due to the distinct dewetting kinetics of the bi-layer and tri-layer films. These NPs exhibit strongly enhanced localized surface plasmon resonance (LSPR) bands in the UV-VIS wavelengths such as dipolar, quadrupolar, multipolar and higher order resonance modes depending upon the size and elemental composition of NPs. The LSPR bands are much stronger with the high Ag content and gradually attenuated with the Ag sublimation. Furthermore, the VIS region LSPR bands are readily blue shifted along with the reduction of NP size. The Ag/Pt bi-layers and Ag/Au/Pt tri-layers are systematically dewetted and transformed into various AgPt and AgAuPt nanostructures such as networked, elongated and semispherical configurations by means of enhanced surface diffusion, intermixing and energy minimization along with the temperature control. The sublimation of Ag atoms plays a significant role in the structural and elemental composition of NPs such that more isolated and semispherical Pt and AuPt NPs are evolved from the AgPt and AgAuPt NPs respectively.

Combination of IBA Techniques for Composition Analysis of GaInAsSb Films

2006 ◽  
Vol 514-516 ◽  
pp. 1603-1607 ◽  
Author(s):  
Victoria Corregidor ◽  
P.C. Chaves ◽  
M.A. Reis ◽  
Carlos Pascual Izarra ◽  
Eduardo Alves ◽  
...  
Keyword(s):  
Elemental Composition ◽  
Rutherford Backscattering Spectrometry ◽  
Ion Beam ◽  
Grazing Angle ◽  
Growth Conditions ◽  
Thin Layers ◽  
Composition Analysis ◽  
Substrate Orientation ◽  
The Matrix ◽  
Lattice Matched

Quaternary GaInAsSb films alloys were grown by MOVPE technique on GaSb substrates with different growth conditions such as substrate orientation and thickness. The composition of the films determines their bandgap, and also how well they are lattice matched to the substrate. It is thus essential to determine it accurately, which is not a trivial task in this system. The composition of the samples was studied with a combination of Particle Induced Xray Emission (PIXE) and Rutherford Backscattering Spectrometry (RBS) experiments. The RBS experiments were done with a 2 MeV 4He+ or H+ ion beam, according to the thickness of the films, and were used to determine the thickness of the samples. The PIXE experiments were performed at grazing angle conditions and provided accurate elemental composition information. It was found that for thin layers (300 nm) there is a dependence of In incorporation into the matrix according to the substrate orientation, although this tendency was not found for thicker films (24m).

scholarly journals Elemental Composition (C, N, P) and Cell Volume of Exponentially Growing and Nutrient-Limited Bacterioplankton

2002 ◽  
Vol 68 (6) ◽  
pp. 2965-2971 ◽  
Author(s):  
Katarina Vrede ◽  
Mikal Heldal ◽  
Svein Norland ◽  
Gunnar Bratbak
Keyword(s):  
Elemental Composition ◽  
Standard Error ◽  
Stationary Phases ◽  
Growth Conditions ◽  
Elemental Content ◽  
Bacterial Cells ◽  
Batch Cultures ◽  
C Cell ◽  
Average Standard Error ◽  
C:P Ratios

ABSTRACT Marine bacterioplankton were isolated and grown in batch cultures until their growth became limited by organic carbon (C), nitrogen (N), or phosphorus (P). Samples were taken from the cultures at both the exponential and stationary phases. The elemental composition of individual bacterial cells was analyzed by X-ray microanalysis with an electron microscope. The cell size was also measured. The elemental content was highest in exponentially growing cells (149 ± 8 fg of C cell−1, 35 ± 2 fg of N cell−1, and 12 ± 1 fg of P cell−1; average of all isolates ± standard error). The lowest C content was found in C-limited cells (39 ± 3 fg of C cell−1), the lowest N content in C- and P-limited cells (12 ± 1 and 12 ± 2 fg of N cell−1, respectively), and the lowest P content in P-limited cells (2.3 ± 0.6 fg of P cell−1). The atomic C:N ratios varied among treatments between 3.8 ± 0.1 and 9.5 ± 1.0 (average ± standard error), the C:P ratios between 35 ± 2 and 178 ± 28, and the N:P ratios between 6.7 ± 0.3 and 18 ± 3. The carbon-volume ratios showed large variation among isolates due to different types of nutrient limitation (from 51± 4 to 241 ± 38 fg of C μm−1; average of individual isolates and treatments ± standard error). The results show that different growth conditions and differences in the bacterial community may explain some of the variability of previously reported elemental and carbon-volume ratios.

Alterations of ultrastructure and elemental composition in cultured human epidermal keratinocytes after treatment with nitrofurazone and silver sulfadiazine

1987 ◽  
Vol 45 ◽  
pp. 676-677
Author(s):  
A. R. Crooker ◽  
M. C. Myers ◽  
T. L. Beard ◽  
E. S. Graham
Keyword(s):  
Electron Microscopy ◽  
Elemental Composition ◽  
Pyrolytic Carbon ◽  
Human Keratinocytes ◽  
Silver Sulfadiazine ◽  
Epidermal Keratinocytes ◽  
Human Epidermal Keratinocytes ◽  
Culture Systems ◽  
Cytotoxicity Endpoints

Cell culture systems have become increasingly popular as a means of screening toxic agents and studying toxic mechanisms of drugs and other chemicals at the cellular and subcellular levels. These in vitro tests can be conducted rapidly in a broad range of relevant mammalian culture systems; a variety of biological and biochemical cytotoxicity endpoints can be examined. The following study utilized human keratinocytes to evaluate the relative cytotoxicities of nitrofurazone (NF) and silver sulfadiazine (SS), the active ingredients of FURACIN(R) Topical Cream and SILVADENE(R) Cream, respectively. These compounds are anti-infectives used in the treatment of burn patients. Cell ultrastructure and elemental composition were utilized as cytotoxicity endpoints.Normal Human Epidermal Keratinocytes (HK) were prepared from the EpiPackTM culture system (Clonetics Corporation, Boulder, CO). For scanning electron microscopy (SEM) and transmission electron microscopy (TEM), cells were seeded on sterile 35 mm Falcon plastic dishes; for elemental microanalysis, cells were plated on polished pyrolytic carbon discs (E. Fullam, Latham, NY) placed in the culture dishes.

Influence of MBE Growth Conditions on Dislocation Densities of GaAs/Ge Epilayers Grown on Silicon Substrates

1985 ◽  
Vol 43 ◽  
pp. 364-365
Author(s):  
K.M. Hones ◽  
P. Sheldon ◽  
B.G. Yacobi ◽  
A. Mason
Keyword(s):  
High Efficiency ◽  
Lattice Mismatch ◽  
Low Cost ◽  
Growth Conditions ◽  
Nonradiative Recombination ◽  
Device Structure ◽  
Si Substrates ◽  
Transmission Electron ◽  
Dislocation Densities ◽  
Dislocation Type

There is increasing interest in growing epitaxial GaAs on Si substrates. Such a device structure would allow low-cost substrates to be used for high-efficiency cascade- junction solar cells. However, high-defect densities may result from the large lattice mismatch (∼4%) between the GaAs epilayer and the silicon substrate. These defects can act as nonradiative recombination centers that can degrade the optical and electrical properties of the epitaxially grown GaAs. For this reason, it is important to optimize epilayer growth conditions in order to minimize resulting dislocation densities. The purpose of this paper is to provide an indication of the quality of the epitaxially grown GaAs layers by using transmission electron microscopy (TEM) to examine dislocation type and density as a function of various growth conditions. In this study an intermediate Ge layer was used to avoid nucleation difficulties observed for GaAs growth directly on Si substrates. GaAs/Ge epilayers were grown by molecular beam epitaxy (MBE) on Si substrates in a manner similar to that described previously.

Electron probe x-ray microanalysis and electron microscopy of amino acid absorption and transport by the small intestine: inhibition by chemical poisons and correlation to the elemental composition of the epithelial cells

1986 ◽  
Vol 44 ◽  
pp. 134-135
Author(s):  
A. J. Tousimis
Keyword(s):  
Small Intestine ◽  
Amino Acid ◽  
Epithelial Cells ◽  
Elemental Composition ◽  
Isotope Labeling ◽  
Structural Components ◽  
X Ray ◽  
Human Small Intestine ◽  
Transport Studies

The elemental composition of amino acids is similar to that of the major structural components of the epithelial cells of the small intestine and other tissues. Therefore, their subcellular localization and concentration measurements are not possible by x-ray microanalysis. Radioactive isotope labeling: I131-tyrosine, Se75-methionine and S35-methionine have been successfully employed in numerous absorption and transport studies. The latter two have been utilized both in vitro and vivo, with similar results in the hamster and human small intestine. Non-radioactive Selenomethionine, since its absorption/transport behavior is assumed to be the same as that of Se75- methionine and S75-methionine could serve as a compound tracer for this amino acid.

Diffraction from arrays of antiphase boundaries in ordered III-V alloys

1987 ◽  
Vol 45 ◽  
pp. 312-313
Author(s):  
T. S. Kuan
Keyword(s):  
High Surface ◽  
Growth Conditions ◽  
Ternary Alloys ◽  
Local Growth ◽  
Antiphase Boundaries ◽  
Surface Mobility ◽  
Ordered Phases ◽  
Diffraction Patterns ◽  
Atomically Flat ◽  
Degree Of Order

Recent electron diffraction studies have found ordered phases in AlxGa1-xAs, GaAsxSb1-x, and InxGa1-xAs alloy systems, and these ordered phases are likely to be found in many other III-V ternary alloys as well. The presence of ordered phases in these alloys was detected in the diffraction patterns through the appearance of superstructure reflections between the Bragg peaks (Fig. 1). The ordered phase observed in the AlxGa1-xAs and InxGa1-xAs systems is of the CuAu-I type, whereas in GaAsxSb1-x this phase and a chalcopyrite type ordered phase can be present simultaneously. The degree of order in these alloys is strongly dependent on the growth conditions, and during the growth of these alloys, high surface mobility of the depositing species is essential for the onset of ordering. Thus, the growth on atomically flat (110) surfaces usually produces much stronger ordering than the growth on (100) surfaces. The degree of order is also affected by the presence of antiphase boundaries (APBs) in the ordered phase. As shown in Fig. 2(a), a perfectly ordered In0.5Ga0.5As structure grown along the <110> direction consists of alternating InAs and GaAs monolayers, but due to local growth fluctuations, two types of APBs can occur: one involves two consecutive InAs monolayers and the other involves two consecutive GaAs monolayers.

The value of Electron Microscope studies of imperfect natural diamonds

1990 ◽  
Vol 48 (4) ◽  
pp. 194-195
Author(s):  
J C Walmsley ◽  
A R Lang
Keyword(s):  
Electron Microscope ◽  
Classification Scheme ◽  
Natural Diamond ◽  
Sudden Change ◽  
Growth Conditions ◽  
Diamond Growth ◽  
Major Constituent ◽  
Natural Diamonds ◽  
Type Ia ◽  
Platelet Defects

Interest in the defects and impurities in natural diamond, which are found in even the most perfect stone, is driven by the fact that diamond growth occurs at a depth of over 120Km. They display characteristics associated with their origin and their journey through the mantle to the surface of the Earth. An optical classification scheme for diamond exists based largely on the presence and segregation of nitrogen. For example type Ia, which includes 98% of all natural diamonds, contain nitrogen aggregated into small non-paramagnetic clusters and usually contain sub-micrometre platelet defects on {100} planes. Numerous transmission electron microscope (TEM) studies of these platelets and associated features have been made e.g. . Some diamonds, however, contain imperfections and impurities that place them outside this main classification scheme. Two such types are described.First, coated-diamonds which possess gem quality cores enclosed by a rind that is rich in submicrometre sized mineral inclusions. The transition from core to coat is quite sharp indicating a sudden change in growth conditions, Figure 1. As part of a TEM study of the inclusions apatite has been identified as a major constituent of the impurity present in many inclusion cavities, Figure 2.

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