scholarly journals Elevated CO2 and nitrate levels increase wheat root-associated bacterial abundance and impact rhizosphere microbial community composition and function

2020 ◽  
Author(s):  
Alla Usyskin-Tonne ◽  
Yitzhak Hadar ◽  
Uri Yermiyahu ◽  
Dror Minz
Keyword(s):  
Bacterial Abundance ◽  
Root Exudation ◽  
Microbial Community Composition ◽  
Wheat Root ◽  
Root Surface ◽  
Structure And Function ◽  
Secretion Systems ◽  
Functional Changes ◽  
And Function ◽  
Mannose Metabolism

AbstractElevated CO2 stimulates plant growth and affects quantity and composition of root exudates, followed by response of its microbiome. Three scenarios representing nitrate fertilization regimes: limited (30 ppm), moderate (70 ppm) and excess nitrate (100 ppm) were compared under ambient and elevated CO2 (eCO2, 850 ppm) to elucidate their combined effects on root-surface-associated bacterial community abundance, structure and function. Wheat root-surface-associated microbiome structure and function, as well as soil and plant properties, were highly influenced by interactions between CO2 and nitrate levels. Relative abundance of total bacteria per plant increased at eCO2 under excess nitrate. Elevated CO2 significantly influenced the abundance of genes encoding enzymes, transporters and secretion systems. Proteobacteria, the largest taxonomic group in wheat roots (~ 75%), is the most influenced group by eCO2 under all nitrate levels. Rhizobiales, Burkholderiales and Pseudomonadales are responsible for most of these functional changes. A correlation was observed among the five gene-groups whose abundance was significantly changed (secretion systems, particularly type VI secretion system, biofilm formation, pyruvate, fructose and mannose metabolism). These changes in bacterial abundance and gene functions may be the result of alteration in root exudation at eCO2, leading to changes in bacteria colonization patterns and influencing their fitness and proliferation.

Cardiovascular adaptations in Andean natives after 6 wk of exposure to sea level

1991 ◽  
Vol 70 (6) ◽  
pp. 2650-2655 ◽  
Author(s):  
D. C. McKenzie ◽  
L. S. Goodman ◽  
C. Nath ◽  
B. Davidson ◽  
G. O. Matheson ◽  
...  
Keyword(s):  
Sea Level ◽  
Barometric Pressure ◽  
Cycle Ergometer ◽  
Left Ventricular ◽  
Structure And Function ◽  
Left Ventricular Ejection ◽  
Noninvasive Methods ◽  
Functional Changes ◽  
And Function ◽  
Quechua Indians

Six male Quechua Indians (34.0 +/- 1.1 yr, 159.5 +/- 2.1 cm, 60.5 +/- 1.6 kg), life-long residents of La Raya, Peru (4,350-m altitude with an average barometric pressure of 460 Torr), were studied using noninvasive methods to determine the structural and functional changes in the cardiovascular system in response to a 6-wk deacclimation period at sea level. Cardiac output, stroke volume, and left ventricular ejection fractions were determined using radionuclide angiographic techniques at rest and during exercise on a cycle ergometer at 40, 60, and 90% of a previously determined maximal O2 consumption. Subjects at rest were subjected to two-dimensional and M-mode echocardiograms and a standard 12-lead electrocardiogram. Hemoglobin and hematocrit were measured on arrival at sea level by use of a Coulter Stacker S+ analyzer. After a 6-wk deacclimation period, all variables were remeasured using the identical methodology. Hemoglobin values decreased significantly over the deacclimation period (15.7 +/- 1.1 to 13.5 +/- 1.2 g/dl; P less than 0.01). The results indicate that the removal of these high-altitude-adapted natives from 4,300 m to sea level for 6 wk results in only minor changes to the cardiac structure and function as measured by these noninvasive techniques.

scholarly journals Effect of mechanical deformation on structure and function of polymorphonuclear leukocytes

1997 ◽  
Vol 82 (5) ◽  
pp. 1397-1405 ◽  
Author(s):  
Yuko Kitagawa ◽  
Stephan F. Van Eeden ◽  
Darlene M. Redenbach ◽  
Maleki Daya ◽  
Blair A. M. Walker ◽  
...  
Keyword(s):  
Polymorphonuclear Leukocytes ◽  
Polarization Characteristic ◽  
Mechanical Deformation ◽  
Structure And Function ◽  
Functional Changes ◽  
Flow Cytometric ◽  
Pulmonary Capillaries ◽  
Pulmonary Capillary ◽  
Capillary Bed ◽  
And Function

Kitagawa, Yuko, Stephan F. Van Eeden, Darlene M. Redenbach, Maleki Daya, Blair A. M. Walker, Maria E. Klut, Barry R. Wiggs, and James C. Hogg. Effect of mechanical deformation on structure and function of polymorphonuclear leukocytes. J. Appl. Physiol. 82(5): 1397–1405, 1997.—The present studies were designed to test the hypothesis that mechanical deformation of polymorphonuclear leukocytes (PMN) leads to functional changes that might influence their transit in the pulmonary capillaries. Human leukocytes were passed through 5- or 3-μm-pore polycarbonate filters under controlled conditions. Morphometric analysis showed that the majority of PMN were deformed and that this deformation persisted longer after filtration through 3-μm filters than through 5-μm filters ( P < 0.05) but did not result in the cytoskeletal polarization characteristic of migrating cells. Flow cytometric studies of the filtered PMN showed that there was a transient increase in the cytosolic free Ca2+ concentration after both 3- and 5-μm filtration ( P< 0.01) with an increase in F-actin content after 3-μm filtration ( P < 0.05). AlthoughL-selectin expression on PMN was not changed by either 5- or 3-μm filtration, CD18 and CD11b were increased by 3-μm filtration ( P < 0.05). Priming of the PMN with N-formyl-methionyl-leucyl-phenylalanine (0.5 nM) before filtration resulted in an increase of CD11b by both 5 ( P < 0.05)- and 3-μm ( P < 0.01) filtration. Neither 5- nor 3-μm filtration induced hydrogen peroxide production. We conclude that mechanical deformation of PMN, similar to what occurs in the pulmonary microvessels, induces both structural and functional changes in the cells, which might influence their passage through the pulmonary capillary bed.

scholarly journals Association between antenatal blood pressure and 5-year postpartum retinal arteriolar structural and functional changes

2019 ◽  
Vol 4 (1) ◽  
pp. e000355 ◽  
Author(s):  
Ralene Sim ◽  
Izzuddin Aris ◽  
Yap-Seng Chong ◽  
Tien Yin Wong ◽  
Ling-jun Li
Keyword(s):  
Blood Pressure ◽  
Mediation Analysis ◽  
Degrees Of Freedom ◽  
Underlying Mechanism ◽  
Structure And Function ◽  
Functional Changes ◽  
Microvascular Changes ◽  
And Function ◽  
Retinal Arteriolar

ObjectiveStudies have shown that hypertensive disorders of pregnancy (HDP) are associated with both postpartum retinal microvascular changes and cardiovascular (CV) risks. However, the underlying mechanism of HDP transitioning to microvascular and macrovascular changes remains unknown, due to the interaction between microvasculature and CV risks. In this study, we examined whether associations between antenatal systolic blood pressure (SBP) and postpartum retinal arteriolar changes are independent of postpartum CV risks.MethodsWe included 276 Singaporean mothers attending both baseline index pregnancy (2009–2010) and 5-year postpartum follow-up visits (2014–2015). We measured SBP at baseline. At follow-up, we assessed retinal microvascular structure and function with retinal photography and dynamic vessel analyser, together with CV risks using a validated 2008 Framingham Risk Score (FRS). We performed a traditional four-step mediation analysis using linear regression by adjusting for a series of baseline characteristics: age, ethnicity, college degree, prepregnancy body mass index and gestational diabetes mellitus diagnosis at baseline.ResultsWe found that each 10 mm Hg increase in baseline SBP was associated with reduced arteriolar calibre (−1.3 µm; 95% CI −3.0 to 0.2) and fractal dimension (−0.4 degrees of freedom (df); −1.0 to 0.2), and significantly with increased arteriolar constriction (0.5%; 0.001 to 1.0) at 5-year postpartum. Even though baseline SBP was associated with postpartum FRS, the latter was not associated with any retinal arteriolar measures. Therefore, no further mediation analysis was required.ConclusionOur study suggested that elevated SBP during pregnancy was associated with suboptimal retinal arteriolar structure and function independent of postpartum CV risks.

Effects of Aging on Nasal Structure and Function

1989 ◽  
Vol 3 (2) ◽  
pp. 59-62 ◽  
Author(s):  
Charles F. Koopmann
Keyword(s):  
Structure And Function ◽  
Functional Changes ◽  
Effects Of Aging ◽  
And Function

The aging nose undergoes structural and functional changes, which can cause alterations in olfaction, breathing, cosmesis, and nutrition, as well as exhibiting increased incidence of epistaxis and rhinitis. A review of these factors and suggestions for management is presented.

scholarly journals Structure and function of the bacterial and fungal gut flora of Neotropical butterflies

2017 ◽  
Author(s):  
Alison Ravenscraft ◽  
Michelle Berry ◽  
Tobin Hammer ◽  
Kabir Peay ◽  
Carol Boggs
Keyword(s):  
Amino Acids ◽  
Microbial Communities ◽  
Bacterial Species ◽  
Microbial Community Composition ◽  
Structure And Function ◽  
Feeding Guilds ◽  
Gut Flora ◽  
Microbial Composition ◽  
Host Diet ◽  
And Function

AbstractThe relationship between animals and their gut flora is simultaneously one of the most common and most complex symbioses on Earth. Despite its ubiquity, our understanding of this invisible but often critical relationship is still in its infancy. We employed adult Neotropical butterflies as a study system to ask three questions: First, how does gut microbial community composition vary across host individuals, species and dietary guilds? Second, how do gut flora compare to food microbial communities? Finally, are gut flora functionally adapted to the chemical makeup of host foods? To answer these questions we captured nearly 300 Costa Rican butterflies representing over 50 species, six families and two feeding guilds: frugivores and nectivores. We characterized the bacteria and fungi in guts, wild fruits and wild nectars via amplicon sequencing and assessed the catabolic abilities of the gut flora via culture-based assays.Gut communities were distinct from food communities, suggesting that the gut environment acts as a strong filter on potential colonists. Nevertheless, gut flora varied widely among individuals and species. On average, a pair of butterflies shared 21% of their bacterial species and 6% of their fungi. Host species explained 25-30% of total variation in microbial communities while host diet explained 4%. However, diet was still relevant at the individual microbe level—half of the most abundant microbial species differed in abundance between frugivores and nectivores. Diet was also related to the functional profile of gut flora: compared to frugivores, nectivores’ gut flora exhibited increased catabolism of sugars and sugar alcohols and decreased catabolism of amino acids, carboxylic acids and dicarboxylic acids. Since fermented juice contains more amino acids and less sugar than nectar, it appears that host diet filters the gut flora by favoring microbes that digest compounds abundant in foods.By quantifying the degree to which gut communities vary among host individuals, species and dietary guilds and evaluating how gut microbial composition and catabolic potential are related to host diet, this study deepens our understanding of the structure and function of one of the most complex and ubiquitous symbioses in the animal kingdom.

scholarly journals Current understanding of cortical structure and function in migraine

Cephalalgia ◽  
2019 ◽  
Vol 39 (13) ◽  
pp. 1683-1699 ◽  
Author(s):  
Else A Tolner ◽  
Shih-Pin Chen ◽  
Katharina Eikermann-Haerter
Keyword(s):  
Structure And Function ◽  
Dynamic Interactions ◽  
Therapeutic Implications ◽  
Functional Changes ◽  
Cortical Structure ◽  
Modifying Factors ◽  
Subcortical Regions ◽  
Underlying Mechanisms ◽  
Cortical Regions ◽  
And Function

Objective To review and discuss the literature on the role of cortical structure and function in migraine. Discussion Structural and functional findings suggest that changes in cortical morphology and function contribute to migraine susceptibility by modulating dynamic interactions across cortical and subcortical networks. The involvement of the cortex in migraine is well established for the aura phase with the underlying phenomenon of cortical spreading depolarization, while increasing evidence suggests an important role for the cortex in perception of head pain and associated sensations. As part of trigeminovascular pain and sensory processing networks, cortical dysfunction is likely to also affect initiation of attacks. Conclusion Morphological and functional changes identified across cortical regions are likely to contribute to initiation, cyclic recurrence and chronification of migraine. Future studies are needed to address underlying mechanisms, including interactions between cortical and subcortical regions and effects of internal (e.g. genetics, gender) and external (e.g. sensory inputs, stress) modifying factors, as well as possible clinical and therapeutic implications.

scholarly journals Molecular mechanisms of cardiomyocyte aging

2011 ◽  
Vol 121 (8) ◽  
pp. 315-329 ◽  
Author(s):  
Anna Sheydina ◽  
Daniel R. Riordon ◽  
Kenneth R. Boheler
Keyword(s):  
Gene Expression ◽  
Cardiovascular Disease ◽  
Cardiovascular Diseases ◽  
Molecular Mechanisms ◽  
Structure And Function ◽  
Functional Changes ◽  
Cellular Changes ◽  
Signalling Cascades ◽  
Time Changes ◽  
And Function

Western societies are rapidly aging, and cardiovascular diseases are the leading cause of death. In fact, age and cardiovascular diseases are positively correlated, and disease syndromes affecting the heart reach epidemic proportions in the very old. Genetic variations and molecular adaptations are the primary contributors to the onset of cardiovascular disease; however, molecular links between age and heart syndromes are complex and involve much more than the passage of time. Changes in CM (cardiomyocyte) structure and function occur with age and precede anatomical and functional changes in the heart. Concomitant with or preceding some of these cellular changes are alterations in gene expression often linked to signalling cascades that may lead to a loss of CMs or reduced function. An understanding of the intrinsic molecular mechanisms underlying these cascading events has been instrumental in forming our current understanding of how CMs adapt with age. In the present review, we describe the molecular mechanisms underlying CM aging and how these changes may contribute to the development of cardiovascular diseases.

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