Differential growth of bowel commensal Bacteroides species on plant xylans of differing structural complexity

2017 ◽  
Vol 157 ◽  
pp. 1374-1382 ◽  
Author(s):  
Manuela Centanni ◽  
Jennifer C. Hutchison ◽  
Susan M. Carnachan ◽  
Alison M. Daines ◽  
William J. Kelly ◽  
...  
Keyword(s):  
Structural Complexity ◽  
Differential Growth ◽  
Bacteroides Species

Differential growth of bowel commensal Bacteroides species on plant xylans of differing structural complexity

2020 ◽  
Author(s):  
M Centanni ◽  
JC Hutchison ◽  
Susan Carnachan ◽  
Alison Daines ◽  
WJ Kelly ◽  
...  
Keyword(s):  
New Zealand ◽  
Related Species ◽  
Intervention Studies ◽  
Structural Complexity ◽  
Commensal Bacteria ◽  
Differential Growth ◽  
Closely Related Species ◽  
Bacteroides Species ◽  
Chemical Structures ◽  
Bacteroides Ovatus

© 2016 Elsevier Ltd Alterations to the composition of the bowel microbiota (dysbioses) are associated with particular diseases and conditions of humans. There is a need to discover new, indigestible polysaccharides which are selective growth substrates for commensal bowel bacteria. These substrates (prebiotics) could be added to food in intervention studies to correct bowel dysbiosis. A collection of commensal bacteria was screened for growth in culture using a highly-branched xylan produced by New Zealand flax. Two, Bacteroides ovatus ATCC 8483 and Bacteroides xylanisolvens DSM 18836 grew well on this substrate. The utilisation of the xylan was studied chromatographically and by constituent sugar analysis. The two closely related species utilised the xylan in different ways, and differently from their use of wheat arabinoxylan. The growth of Bacteroides species on other plant xylans having differing chemical structures was also investigated. Novel xylans expand the choice of potential prebiotics that could be used to correct bowel dysbioses.

Differential growth of bowel commensal Bacteroides species on plant xylans of differing structural complexity

2020 ◽  
Author(s):  
M Centanni ◽  
JC Hutchison ◽  
Susan Carnachan ◽  
Alison Daines ◽  
WJ Kelly ◽  
...  
Keyword(s):  
New Zealand ◽  
Related Species ◽  
Intervention Studies ◽  
Structural Complexity ◽  
Commensal Bacteria ◽  
Differential Growth ◽  
Closely Related Species ◽  
Bacteroides Species ◽  
Chemical Structures ◽  
Bacteroides Ovatus

© 2016 Elsevier Ltd Alterations to the composition of the bowel microbiota (dysbioses) are associated with particular diseases and conditions of humans. There is a need to discover new, indigestible polysaccharides which are selective growth substrates for commensal bowel bacteria. These substrates (prebiotics) could be added to food in intervention studies to correct bowel dysbiosis. A collection of commensal bacteria was screened for growth in culture using a highly-branched xylan produced by New Zealand flax. Two, Bacteroides ovatus ATCC 8483 and Bacteroides xylanisolvens DSM 18836 grew well on this substrate. The utilisation of the xylan was studied chromatographically and by constituent sugar analysis. The two closely related species utilised the xylan in different ways, and differently from their use of wheat arabinoxylan. The growth of Bacteroides species on other plant xylans having differing chemical structures was also investigated. Novel xylans expand the choice of potential prebiotics that could be used to correct bowel dysbioses.

Differential growth response to increasing growing stock and structural complexity in even- and uneven-sized mixed Picea abies stands in southern Finland

2016 ◽  
Vol 46 (10) ◽  
pp. 1195-1204
Author(s):  
Eric K. Zenner
Keyword(s):  
Growth Response ◽  
Structural Complexity ◽  
Basal Area ◽  
The Other ◽  
Selection System ◽  
Differential Growth ◽  
Widespread Application ◽  
Growing Stock ◽  
Large Trees ◽  
Silvicultural System

Widespread application of the selection system will depend on whether creating stands with uneven-sized (UES) structures comes at the expense of net periodic annual basal area increment (PAI) compared with stands with even-sized (ES) structures. I modeled PAI on growing stock and structural complexity over 12 years in midrotation stands with ES and UES structure types. Average PAI of the largest trees did not differ among types and decreased with increasing stocking, whereas PAI of the smallest trees in the UES type declined with stocking. Trees ≥ 10 cm in diameter grew more slowly in the ES type than the UES type, but no difference was seen after incorporating small trees (down to 5 or 2 cm). In the ES type, PAI of most trees increased linearly with increasing stocking, whereas in the UES type, it increased only up to ∼20 m2·ha−1. As structural complexity increased, PAI of the largest trees increased in the ES type, whereas PAI of all but the largest trees decreased in the UES type. Neither silvicultural system was innately more productive, as each can outperform the other under optimal levels of stocking and structural complexity. However, optimizing increment of only large trees would undermine the UES type.

Conformation of eukaryotic ribosomal RNAs

1983 ◽  
Vol 41 ◽  
pp. 592-593
Author(s):  
M. Boublik ◽  
G. Thornton ◽  
G. Oostergetel ◽  
J.F. Hainfeld ◽  
J.S. Wall
Keyword(s):  
Molecular Weight ◽  
Mass Measurement ◽  
Carbon Film ◽  
Structural Complexity ◽  
Scanning Transmission Electron Microscope ◽  
Electron Microscopic ◽  
Pure Nitrogen ◽  
Freeze Dried ◽  
Scanning Transmission ◽  
Partially Unfolded

Understanding the structural complexity of ribosomes and their role in protein synthesis requires knowledge of the conformation of their components - rRNAs and proteins. Application of dedicated scanning transmission electron microscope (STEM), electrical discharge of the support carbon film in an atmosphere of pure nitrogen, and determination of the molecular weight of individual rRNAs enabled us to obtain high resolution electron microscopic images of unstained freeze-dried rRNA molecules from BHK cells in a form suitable for evaluation of their 3-D structure. Preliminary values for the molecular weight of 28S RNA from the large and 18S RNA from the small ribosomal subunits as obtained by mass measurement were 1.84 x 106 and 0.97 x 106, respectively. Conformation of rRNAs consists, in general, of alternating segments of intramolecular hairpin stems and single stranded loops in a proportion which depends on their ionic environment, the Mg++ concentration in particular. Molecules of 28S RNA (Fig. 1) and 18S RNA (not shown) obtained by freeze-drying from a solution of 60 mM NH+4 acetate and 2 mM Mg++ acetate, pH 7, appear as partially unfolded coils with compact cores suggesting a high degree of ordered secondary structure.

Observations of Frozen-Hydrated Microtubules

1990 ◽  
Vol 48 (1) ◽  
pp. 504-505
Author(s):  
D. Chrétien ◽  
D. Job ◽  
R.H. Wade
Keyword(s):  
Fourier Transforms ◽  
Structural Complexity ◽  
Image Contrast ◽  
Phase Behaviour ◽  
Experimental Conditions ◽  
Thin Sections ◽  
Surface Lattice ◽  
Cilia And Flagella ◽  
Outstanding Question

Microtubules are filamentary structures found in the cytoplasm of eukaryotic cells, where, together with actin and intermediate filaments, they form the components of the cytoskeleton. They have many functions and show various levels of structural complexity as witnessed by the singlet, doublet and triplet structures involved in the architecture of centrioles, basal bodies, cilia and flagella. The accepted microtubule model consists of a 25 nm diameter hollow tube with a wall made up of 13 paraxial protofilaments (pf). Each pf is a string of aligned tubulin dimers. Some results have suggested that the pfs follow a superhelix. To understand how microtubules function in the cell an accurate model of the surface lattice is one of the requirements. For example the 9x2 architecture of the axoneme will depend on the organisation of its component microtubules. We should also note that microtubules with different numbers of pfs have been observed in thin sections of cellular and of in-vitro material. An outstanding question is how does the surface lattice adjust to these different pf numbers?We have been using cryo-electron microscopy of frozen-hydrated samples to study in-vitro assembled microtubules. The experimental conditions are described in detail in this reference. The results obtained in conjunction with thin sections of similar specimens and with axoneme outer doublet fragments have already allowed us to characterise the image contrast of 13, 14 and 15 pf microtubules on the basis of the measured image widths, of the the image contrast symmetry and of the amplitude and phase behaviour along the equator in the computed Fourier transforms. The contrast variations along individual microtubule images can be interpreted in terms of the geometry of the microtubule surface lattice. We can extend these results and make some reasonable predictions about the probable surface lattices in the case of other pf numbers, see Table 1. Figure 1 shows observed images with which these predictions can be compared.

Structural Aspects of Phonological Development

1988 ◽  
Vol 19 (1) ◽  
pp. 5-16 ◽  
Author(s):  
Karen E. Pollock ◽  
Richard G. Schwartz
Keyword(s):  
Clinical Management ◽  
Structural Complexity ◽  
Strong Preference ◽  
Phonological Development ◽  
Structural Position ◽  
Phonological Disorders ◽  
Syllabic Structure ◽  
The Relationship ◽  
Structural Aspects ◽  
Target Words

The relationship between syllabic structure and segmental development was examined longitudinally in a child with a severe phonological disorder. Six speech samples were collected over a 4-year period (3:5 to 7:3). Analyses revealed gradual increases in the complexity and diversity of the syllable structures produced, and positional preferences for sounds within these forms. With a strong preference for [d] and [n] at the beginning of syllables, other consonants appeared first at the end of syllables. Implications for clinical management of phonological disorders include the need to consider both structural position and structural complexity in assessing segmental skills and in choosing target words for intervention.

Differential growth effect of regenerating (reg) protein on a rat ß-cell line

2001 ◽  
Vol 120 (5) ◽  
pp. A338-A339
Author(s):  
Z FAN ◽  
H WU ◽  
S PATEL ◽  
M ZENILMAN
Keyword(s):  
Cell Line ◽  
Growth Effect ◽  
Differential Growth

Spatial Metabolomics of the Human Kidney Using MALDI Trapped Ion Mobility Imaging Mass Spectrometry

2020 ◽  
Author(s):  
Elizabeth Neumann ◽  
Lukasz Migas ◽  
Jamie L. Allen ◽  
Richard Caprioli ◽  
Raf Van de Plas ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Ion Mobility ◽  
Imaging Mass Spectrometry ◽  
Structural Complexity ◽  
Human Kidney ◽  
Resolving Power ◽  
Mobility Separation ◽  
Trapped Ion ◽  
Mobility Data ◽  
Ion Mobility Separation

<div> <div> <p>Small metabolites are essential for normal and diseased biological function but are difficult to study because of their inherent structural complexity. MALDI imaging mass spectrometry (IMS) of small metabolites is particularly challenging as MALDI matrix clusters are often isobaric with metabolite ions, requiring high resolving power instrumentation or derivatization to circumvent this issue. An alternative to this is to perform ion mobility separation before ion detection, enabling the visualization of metabolites without the interference of matrix ions. Here, we use MALDI timsTOF IMS to image small metabolites at high spatial resolution within the human kidney. Through this, we have found metabolites, such as arginic acid, acetylcarnitine, and choline that localize to the cortex, medulla, and renal pelvis, respectively. We have also demonstrated that trapped ion mobility spectrometry (TIMS) can resolve matrix peaks from metabolite signal and separate both isobaric and isomeric metabolites with different localizations within the kidney. The added ion mobility data dimension dramatically increased the peak capacity for molecular imaging experiments. Future work will involve further exploring the small metabolite profiles of human kidneys as a function of age, gender, and ethnicity.</p></div></div>

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