scholarly journals Xylem sap phosphorus sampling using microdialysis—a non-destructive high sampling frequency method tested under laboratory and field conditions

2020 ◽  
Vol 40 (11) ◽  
pp. 1623-1638
Author(s):  
Jakub Jeřábek ◽  
Michael Rinderer ◽  
Arthur Gessler ◽  
Markus Weiler
Keyword(s):  
Sap Flow ◽  
Xylem Sap ◽  
Field Application ◽  
Field Conditions ◽  
Stem Segment ◽  
Frequency Method ◽  
Destructive Sampling ◽  
Flow Measurements

Abstract For a better understanding of plant nutrition processes, it is important to study the flux of nutrients within plants. However, existing xylem sap sampling methods are typically destructive and do not allow for repeated, highly frequent measurements of nutrient concentration. In this paper, we present a novel use of microdialysis (MD) for characterizing xylem sap phosphate (PO43−) concentration as a possible alternative to destructive sampling. First, MD probes were tested under laboratory conditions in vitro, in a stirred solution test, and in vivo, using beech tree stem segments. Exponential decline in the relative recovery (RR) with an increasing MD pumping rate allows for determining an optimal sampling interval (i.e., the maximum amount of sample volume with the minimum required concentration). The RR changed only minimally, with a change in the simulated sap flow velocity during the in vivo stem segment test. This suggests that MD can be applied over a range of naturally occurring sap flow velocities. Differences in the ionic strength between the xylem sap and the perfusate pumped through the MD did not influence the RR. Then, MD was successfully applied in a 24 h field campaign in two beech trees of different ages and allowed for in situ assessments of the diurnal variation of PO43− concentration and (together with xylem flow measurements) flux variability in living trees. Both beech trees exhibited the same diurnal pattern in PO43− concentrations with higher concentrations in the younger tree. The xylem PO43− concentration measured with MD was in the same order of magnitude as that received through destructive sampling in the younger tree. The MD probes did not show a decline in RR after the field application. We showed that MD can be applied to capture the PO43− concentration dynamics in the xylem sap with bihourly resolution under field conditions.

scholarly journals Chemical and biological control of Fusarium species involved in garlic dry rot at early crop stages

2021 ◽  
Author(s):  
Letizia Mondani ◽  
Giorgio Chiusa ◽  
Paola Battilani
Keyword(s):  
Growth Inhibition ◽  
Fusarium Species ◽  
Maximum Growth ◽  
Severity Index ◽  
Field Application ◽  
Dry Rot ◽  
Great Capacity ◽  
Chemical Products

AbstractThe aim of the study was to test in vitro and in vivo the efficacy of triazoles and biocontrol agents (BCAs) against Fusarium proliferatum and F. oxysporum, the former signaled as the main causal agent of garlic dry rot and the latter also involved. In vitro trials were organized using potato dextrose agar with added chemicals or BCAs inoculated with selected F. proliferatum and F. oxysporum. Garlic cloves were dipped before sowing in suspensions prepared with the fungicides showing the best performances in vitro; then they were dipped in Fusaria suspension before sowing. In in vitro trials, the maximum Fusaria growth inhibition was performed by Propiconazole + Prochloraz (100%), followed by Tebuconazole (88.9%). BCAs showed great capacity to control Fusaria, with a maximum growth inhibition of 80% (Trichoderma harzianum + T. gamsii). In vivo bacterial BCAs showed a similar capacity to control F. proliferatum and F. oxysporum compared to chemical products (mean of severity index 18.6% and 11.7%, respectively). In vivo results confirmed the in vitro performances, except for Trichoderma, which had the worst performances in vivo. Therefore, the results are preliminary but promising for future field application.

Hemodynamics in the abdominal aorta: a comparison of in vitro and in vivo measurements

1994 ◽  
Vol 76 (4) ◽  
pp. 1520-1527 ◽  
Author(s):  
J. E. Moore ◽  
S. E. Maier ◽  
D. N. Ku ◽  
P. Boesiger
Keyword(s):  
Abdominal Aorta ◽  
Velocity Profiles ◽  
Flow Reversal ◽  
Infrarenal Aorta ◽  
Complex Flow ◽  
Flow Measurements ◽  
In Vivo Measurements ◽  
Made In

In vivo measurements of blood velocity profiles are difficult to obtain and interpret, since the parameters that govern the normally highly complex flow situation may not be fully quantified or understood at the time of measurement. In vitro flow models have been used often to better understand vascular hemodynamics. The assumptions made in the design of these models limit the applicability of the results. In this study, in vitro flow measurements made in a carefully designed model of the abdominal aorta were compared with in vivo measurements obtained with magnetic resonance imaging. In the suprarenal aorta, the velocity profiles were mostly forward and axisymmetric in both the in vitro and in vivo cases. In the infrarenal aorta, there was extensive flow reversal noted near the posterior wall in both cases. In the aortic bifurcation, two peaks of flow reversal were noted near the lateral posterior walls, and M-shaped velocity profiles were observed in late diastole. The in vitro and in vivo measurements exhibited good qualitative agreement. The in vitro model was accurate in modeling the in vivo hemodynamics of the abdominal aorta. The complex phenomena observed in vivo were explained on the basis of knowledge gained from the in vitro study.

scholarly journals In vivo pressure gradient heterogeneity increases flow contribution of small diameter vessels in grapevine

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Martin Bouda ◽  
Carel W. Windt ◽  
Andrew J. McElrone ◽  
Craig R. Brodersen
Keyword(s):  
Sap Flow ◽  
Xylem Sap ◽  
Small Diameter ◽  
Fourth Power ◽  
First Year ◽  
Long Distance ◽  
Xylem Sap Flow ◽  
Flow Mri ◽  
Vessel Network

AbstractLeaves lose approximately 400 H2O molecules for every 1 CO2 gained during photosynthesis. Most long-distance water transport in plants, or xylem sap flow, serves to replace this water to prevent desiccation. Theory predicts that the largest vessels contribute disproportionately to overall sap flow because flow in pipe-like systems scales with the fourth power of radius. Here, we confront these theoretical flow predictions for a vessel network reconstructed from X-ray μCT imagery with in vivo flow MRI observations from the same sample of a first-year grapevine stem. Theoretical flow rate predictions based on vessel diameters are not supported. The heterogeneity of the vessel network gives rise to transverse pressure gradients that redirect flow from wide to narrow vessels, reducing the contribution of wide vessels to sap flow by 15% of the total. Our results call for an update of the current working model of the xylem to account for its heterogeneity.

scholarly journals Ghrelin in rat pancreatic islets decreases islet blood flow

2019 ◽  
Vol 317 (1) ◽  
pp. E139-E146 ◽  
Author(s):  
Carl Johan Drott ◽  
Petra Franzén ◽  
Per-Ola Carlsson
Keyword(s):  
Blood Flow ◽  
Insulin Response ◽  
Physiological Mechanism ◽  
Growth Hormone Secretagogue Receptor ◽  
Flow Measurements ◽  
Growth Hormone Secretagogue ◽  
Islet Blood Flow ◽  
Fasted Rats

The peptide ghrelin is mainly produced in some of the epithelial cells in the stomach, but also, during starvation, by the ε-cells in the endocrine pancreas. Ghrelin, as an endogenous ligand for the growth hormone secretagogue receptor (GHS-R1α), exerts a variety of metabolic functions including stimulation of appetite and weight gain. Its complete role is not yet fully understood, including whether it has any vascular functions. The present study evaluated if ghrelin affects pancreatic and islet blood flow. Ghrelin and the GHS-R1α receptor antagonist GHRP-6 were injected intravenously in rats followed by blood flow measurements using a microsphere technique. Ghrelin decreased, while GHRP-6 in fasted, but not fed, rats selectively increased islet blood flow fourfold. GHS-R1α was identified not only on glucagon-producing cells but also seemed to be present in the islet arterioles. GHRP-6 in fasted rats, only, also improved the peak insulin response to glucose in vivo, thereby substantially blunting the hyperglycemia. GHRP-6 doubled glucose-stimulated insulin release in vitro of both islets obtained from fed and fasted rats. Our results indicate a novel role for endogenous ghrelin acting directly or indirectly as a local vasoconstrictor in the islets during fasting, thereby restricting the insulin response to hyperglycemia. This is to the best of our knowledge the first report that shows this physiological mechanism to restrict insulin delivery from the islets by acting on the vasculature; a mode of action that can be envisaged to complement the previously well-described mechanisms of ghrelin acting directly on the islet endocrine cells.

scholarly journals In Vitro and In Vivo Effect of Poplar Bud Extracts on Phytophthora infestans: A New Effective Biological Method in Potato Late Blight Control

Plants ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 217 ◽  
Author(s):  
Botond Turóczi ◽  
József Bakonyi ◽  
Károly-Attila Szabó ◽  
János Bálint ◽  
István Máthé ◽  
...  
Keyword(s):  
Growth Rate ◽  
Late Blight ◽  
Low Cost ◽  
Infection Intensity ◽  
Field Conditions ◽  
Biological Method ◽  
Environmentally Friendly Approach ◽  
Open Field Condition

The effect of populin extract from black poplar (Populus nigra) on seven different late blight strains was tested under laboratory and field conditions. The growth rate of hyphae was found to be significantly lower in vitro after 3 and 4 v/v% populin applications. Stain M16 was resistant to populin treatment under lab conditions, however. Both 5% and 10% concentration populin reduced the M16 strain’s severity on potato leaves under field conditions and proved to be even more effective than conventionally used fungicides Infinito 687 Sc and Valis M. Higher infection intensity at the 1% level was observed after 24 h using Valis M, and the same trend toward 10% infection remained after 48 and 72 h as well. Low, almost-no-infection intensity was detected after populin 5% and 10% treatment under an open field condition. Altogether, it can be concluded that populin extract can be a low-cost option for growers and an environmentally friendly approach in late blight control.

scholarly journals Estimation of the degradability of dietary protein in the sheep rumen by in vivo and in vitro procedures

1985 ◽  
Vol 54 (2) ◽  
pp. 545-561 ◽  
Author(s):  
R. C Siddons ◽  
J Paradine ◽  
D. L. Gale ◽  
R. T. Evans
Keyword(s):  
Rumen Fluid ◽  
Flow Measurements ◽  
Fractional Rate ◽  
Outflow Rate ◽  
Bean Meal ◽  
Sheep Rumen ◽  
Soya Bean Meal ◽  
Microbial N

1. Estimates of degradability of nitrogen in the sheep rumen for a basal hay diet and for soya-bean meal (SBM), groundnut meal (GNM) and fish meal (FM), when given together with the hay, were determined from measurements of (1) duodenal N flow, (2) ammonia kinetics and (3) rumen N disappearance from polyester bags and rumen outflow rate. The ability of various in vitro procedures to predict in vivo N degradability was also examined.2. Four sheep were given a basal hay diet (800 g dry matter (DM) and 19 g N/d) either alone or supplemented with isonitrogenous amounts (15 g N/d) of SBM, GNM or FM. Duodenal non-ammonia-N flow (g/d) was increased more by FM (8.0) than by GNM (5.9) and SBM (5.8), whilst microbial N flow (g/d) was increased more by SBM (3.9) than by GNM (2.3) and FM (1.6). N degradability values calculated from these results were 0.88, 0.76 and 0.57 for the SBM, GNM and FM respectively. The corresponding value for hay was calculated to be 0.76.3. The irreversible loss of ammonia in the forestomachs (g N/d) was increased more by SBM (11.9) than by GNM (7.2) and FM (5.8) whilst ammonia outflow from the rumen (g N/d) was increased to a similar extent by all supplements ( I.1, 0.9 and 0.8 respectively), as was the amount of microbial N (g/d) synthesized from sources other than rumen ammonia (1.8, 2.0 and 1.9 respectively). N degradability values calculated from these results were 0.84, 0.54 and 0.45 for the SBM, GNM and FM respectively.4. The fractional rate of N disappearance (/h) when the feedstuffs were incubated in polyester bags in the rumen of sheep receiving the basal hay diet (800 g DM/d) was the highest for SBM (0,145) and lowest for FM (0.037), with the hay (0.082) and GNM (0.071) intermediate, whilst the fractional outflow rates from the rumen (/h) of the three supplements were similar (0.034, 0.038 and 0,030 for SBM, GNM and FM espectively). N degradability values calculated from these results were 0.82, 0.67 and 0.60 for the SBM, GNM and FM respectively; the value for the hay was 0.73.5. Of a number of in vitro procedures tested, only N solubility in sodium hydroxide and ammonia or total non-protein-N (NPN) production during incubation with rumen fluid in the absence of hydrazine sulphate ranked the supplements, although not the hay, in the same order as the in vivo degradability procedures. In terms of absolute values, N solubility in NaOH, at room temperature, gave estimates similar to those derived from the duodenal flow measurements; estimates derived from ammonia and total NPN production were lower.

scholarly journals In vitro and in vivo effect of poplar bud (Populi gemma) Extracts on late blight (Phytophthora infestans)

2014 ◽  
Vol 6 (1) ◽  
pp. 5-12
Author(s):  
János Bálint ◽  
Botond Turóczi ◽  
István Máthé ◽  
Klára Benedek ◽  
Károly-Attila Szabó ◽  
...  
Keyword(s):  
Growth Rate ◽  
Late Blight ◽  
Phytophthora Infestans ◽  
Environmentally Friendly ◽  
Populus Nigra ◽  
Field Conditions ◽  
Black Poplar

Abstract The effect of populin extract from black poplar (Populus nigra) on late blight was assessed under laboratory and field conditions. The growth rate of hyphae was found to be significantly lower after 1v/v% populin application, and no hyphae growth was detected under 3 and 6v/v% populin application. Populin also reduced the light blight severity on potato leaves under field conditions. From our results, we have concluded that populin extract can be considered as a new and environmentally-friendly alternative for the control of late blight under field conditions.

Correlative Cellular Analyses in a Phase I Trial (Safety and Efficacy of Autologous Intracoronary Stem Cell Injections in Total Coronary Artery Occlusions (SEACOAST)) of Autologous Bone Marrow-Derived CD133 Cells.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 1689-1689
Author(s):  
N.J. Greco ◽  
V.J. Pompili ◽  
H.M. Lazarus ◽  
D. Adler ◽  
T. Lasser ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Phase I ◽  
Phase I Trial ◽  
Mononuclear Cells ◽  
Cellular Therapy ◽  
Normal Donor ◽  
Artery Ligation ◽  
Flow Measurements

Abstract Correlative laboratory studies were developed in a phase I trial to evaluate the safety of intracoronary injection of escalating doses of bone marrow (BM) CD133+ cells in patients with chronic coronary ischemia. Concurrent with patient cellular therapy, CD133+ cells were phenotyped and tested functionally with endothelial cell colony formation and in vitro and in vivo transmigration. BM (194 ± 11 ml) was isolated from patients meeting study inclusion criteria. CD133+ cells (20 ± 13 x 106, 84 ± 7% purity and 76 ± 7% viability (7AAD)) were isolated using the CliniMACS device (Miltenyi). Contaminating cells following the CliniMACS selection were: < 5% of CD3, CD3neg/CD56, CD19 (immature/mature), CD14, and CD71 cells with 5% CD61, 8% CD13+ SSChigh. BM, PB (peripheral blood), cord blood (CB)-derived endothelial progenitor cells (EPC) were assessed by a culture assay (StemCell Technologies) scoring early outgrowth CFU-EC. SEACOAST patients yielded significantly less colonies compared to controls of matched PB and BM (donors 28–48 yrs) and CB: normal donor (ND) PB, 65; ND BM, 40; CB, 43; SEACOAST patient PB, 2, SEACOAST patient BM, 1. Transmigration assays were used to evaluate the functionality of selected CD133+ cells to chemotactic agents stromal derived factor-1 (SDF-1) and vascular endothelial growth factor (VEGF). Selected CD133+ cells were recovered, resuspended in DMEM/1% HSA media and after a 37°C incubation for 16–20 hrs, 5 x 104 CD133+ cells were added to transwells (5 mm) for 3 hours. Transmigrated cells were quantitated by flow cytometry using anti-CD45, anti-CD133 antibodies, and Fluorosphere beads. Surface expression on ND BM CD133+ cells of CXCR4 and VEGF-R2 was 0–16.4% and 1.2–4.3%, respectively. Transmigration was effected by 200 ng/ml (range of 16–62%) but not to 10 ng/ml VEGF. For CD133+ cells devoid of the expression of CXCR4, SDF-1-induced transmigration was absent. Expression of CXCR4 and VEGF-R2 on clinical trial patient-selected CD133+ cells was 0–5% and 0–2%, respectively, and transmigration was 5–19% to 200 ng/ml SDF-1 but not to 10 ng/ml VEGF. Patient selected CD133+ cells or PB mononuclear cells (PBMC), ND CD133+ cells, or a vehicle control were injected via a left intraventricular route into NOD/SCID mice with a femoral artery ligation immediately after injury. Doppler flow measurements were obtained weekly for 6 weeks comparing the perfusion ratio of ischemic/healthy limbs. At 28 days, perfusion ratios were statistically higher in study groups receiving ND CD133+ cells (0.51 ± 0.06) compared to controls (0.37 ± 0.03, p=0.025). Mice receiving patient CD133+ cells (0.46 ± 0.04) or PBMC (0.37 ± 0.08) did not show statistically significant improvement over control animals (p= 0.07, p= 0.94, respectively). BM was harvested to assess human engraftment by cytometric analysis. Mice injected with 0.5 x 106 patient BM CD133+ cells showed <0.2% huCD45+ cells compared to 1.6 ± 0.4% ND BM huCD45+. Beyond the demonstrated safety of the delivery of CD133+ cells (>70% purity and >70% viability) to chronic ischemic patients via an intracoronary route, important correlative in vitro and in vivo assays has demonstrated the diminished potency of BM-derived CD133+ cells as compared to CB and ND PB and BM-derived cells.

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