scholarly journals Multiple coordination and quaternary states of fish hemoglobin re-open the root effect question

2008 ◽  
Vol 64 (a1) ◽  
pp. C379-C379
Author(s):  
L. Mazzarella ◽  
L. Vitagliano ◽  
A. Vergara ◽  
A. Merlino ◽  
C. Verde ◽  
...  
Keyword(s):  
1993 ◽  
Vol 218 (3) ◽  
pp. 829-835 ◽  
Author(s):  
Angela FAGO ◽  
Mario ROMANO ◽  
Maurizio TAMBURRINI ◽  
Massimo COLETTA ◽  
Rossana D'AVINNO ◽  
...  

2019 ◽  
Vol 95 (10) ◽  
Author(s):  
Mengli Zhao ◽  
Jun Yuan ◽  
Zongzhuan Shen ◽  
Menghui Dong ◽  
Hongjun Liu ◽  
...  

ABSTRACT Rhizosphere community assembly is simultaneously affected by both plants and bulk soils and is vital for plant health. However, it is still unclear how and to what extent disease-suppressive rhizosphere microbiota can be constructed from bulk soil, and the underlying agents involved in the process that render the rhizosphere suppressive against pathogenic microbes remain elusive. In this study, the evolutionary processes of the rhizosphere microbiome were explored based on transplanting plants previously growing in distinct disease-incidence soils to one disease-suppressive soil. Our results showed that distinct rhizoplane bacterial communities were assembled on account of the original bulk soil communities with different disease incidences. Furthermore, the bacterial communities in the transplanted rhizosphere were noticeably influenced by the second disease-suppressive microbial pool, rather than that of original formed rhizoplane microbiota and homogenous nontransplanted rhizosphere microbiome, contributing to a significant decrease in the pathogen population. In addition, Spearman's correlations between relative abundances of bacterial taxa and the abundance of Ralstonia solanacearum indicated Anoxybacillus, Flavobacterium, Permianibacter and Pseudomonas were predicted to be associated with disease-suppressive function formation. Altogether, our results showed that bulk soil played an important role in the process of assembling and reassembling the rhizosphere microbiome of plants.


2016 ◽  
Author(s):  
Maria Aparicio-Sanchez ◽  
Alvaro Gonzalez-Salcedp ◽  
Sugoi Gomez-Iradi ◽  
Xabier Munduate

Abstract. Aeroelastic codes based on Blade Element Momentum theory are the standard used by many wind turbine designers. These codes usually include models and corrections for unsteady aerodynamics, tip and root effect, tower shadow and other effects. In general, this kind of codes does not include models to adequately simulate aerodynamic control devices. This paper presents a method to take into account the unsteady contributions due to the flap motion (based on indicial models) and the spanwise effects (based on circulation theory), in order to simulate flaps on the blades. This method can be included in BEM codes in general and it could also be applied to another kind of control devices. The validation and verification show the accuracy of this method using experimental data for two-dimensional unsteady cases, and CFD for three-dimensional steady and unsteady cases.


Author(s):  
Bernd Pelster ◽  
David Randall
Keyword(s):  

Author(s):  
Till S Harter ◽  
Alexander M Clifford ◽  
Martin Tresguerres

White seabass (Atractoscion nobilis) increasingly experience periods of low oxygen (O2; hypoxia) and high carbon dioxide (CO2, hypercapnia) due to climate change and eutrophication of the coastal waters of California. Hemoglobin (Hb) is the principal O2 carrier in the blood and in many teleost fishes Hb-O2 binding is compromised at low pH; however, the red blood cells (RBC) of some species regulate intracellular pH with adrenergically-stimulated sodium-proton-exchangers (β-NHE). We hypothesized that RBC β-NHEs in white seabass are an important mechanism that can protect the blood O2-carrying capacity during hypoxia and hypercapnia. We determined the O2-binding characteristics of white seabass blood, the cellular and sub-cellular response of RBCs to adrenergic stimulation, and quantified the protective effect of β-NHE activity on Hb-O2 saturation. White seabass had typical teleost Hb characteristics, with a moderate O2 affinity (PO2 at half-saturation; P50 2.9 kPa) that was highly pH-sensitive (Bohr coefficient -0.92; Root effect 52%). Novel findings from super-resolution microscopy revealed β-NHE protein in vesicle-like structures and its translocation into the membrane after adrenergic stimulation. Microscopy data were corroborated by molecular and phylogenetic results, and a functional characterization of β-NHE activity. The activation of RBC β-NHEs increased Hb-O2 saturation by ~8% in normoxic hypercapnia, and by up to ~20% in hypoxic normocapnia. Our results provide novel insight into the cellular mechanism of adrenergic RBC stimulation within an ecologically relevant context. β-NHE activity in white seabass has great potential to protect arterial O2 transport during hypoxia and hypercapnia but is less effective during combinations of these stressors.


1965 ◽  
Vol 209 (5) ◽  
pp. 991-998 ◽  
Author(s):  
Claude Lenfant ◽  
Kjell Johansen

O2 and CO2 dissociation curves have been obtained for the hemocyanin-containing blood from the large Cephalopod, Octopus dofleini. The oxyhemocyanin curves showed a typical sigmoid shape. Values for T50 and T100 at 11 C and 0.4 mm Hg Pco2 were 15 and 70 mm Hg Po2, respectively. The amount of dissolved O2 in the blood at higher Po2 was considerable and could reach 10% of the total O2. The O2 capacity averaged 3.06 vol %. Dissolved carbon dioxide decreased the affinity of hemocyanin (Hcy) for O2 (Bohr effect) and reduced the O2 content at saturation (Root effect). At increased temperature the affinity to oxygen was decreased. The CO2 dissociation curves showed a moderate CO2-combining power. A distinct difference in CO2-combining power between oxygenated and reduced blood was present (Haldane effect). This difference was limited to the physiological range of Pco2. Increased temperature decreased the CO2-combining power. The buffering capacity of the blood was low, but in the physiological range of pH there was a distinct difference in buffering ability between reduced and oxygenated blood. The findings are discussed in relation to other marine animals.


1996 ◽  
Vol 3 (3) ◽  
pp. 211-212 ◽  
Author(s):  
M.F. Perutz
Keyword(s):  

2002 ◽  
Vol 62 (4a) ◽  
pp. 595-599 ◽  
Author(s):  
G. F. LANDINI ◽  
A. R. SCHWANTES ◽  
M. L. B. SCHWANTES

Electrophoretic patterns of hemoglobins, Root effect, Bohr effect in blood and stripped hemoglobin, Hb-O2 affinity GTP modulation of Astyanax scabripinnis (lambari), caught at three different altitudes in Ribeirão Grande, near Campos do Jordão (São Paulo), are described. All populations showed the same electrophoretic patterns: two cathodal components in starch gel. Normal Bohr effect values were found in these three populations both in blood (phi = -0,11) and stripped hemoglobin (phi = -0,12). Different blood O2 affinities collected in fish of these 3 populations were detected. GTP has a large influence on Hb-O2 binding properties in A. scabripinnis. Stripped hemoglobin shows small Root effect. The addition of triphosphated nucleotides increases this effect. GTP is more effective than ATP on enhancing Root effect. Oxygen availability in water can be the factor responsible for differences found in blood O2 affinity.


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