The extra‐vascular water pathway regulates dynamic leaf hydraulic decline and recovery in Populus nigra

2020 ◽  
Author(s):  
Patrizia Trifilò ◽  
Francesco Petruzzellis ◽  
Elisa Abate ◽  
Andrea Nardini
Keyword(s):  
Populus Nigra ◽  
Water Pathway

Hydraulic and diffusional permeabilities of isolated outer medullary descending vasa recta from the rat

1997 ◽  
Vol 272 (1) ◽  
pp. H392-H400 ◽  
Author(s):  
M. R. Turner ◽  
T. L. Pallone
Keyword(s):  
Hydraulic Permeability ◽  
Oncotic Pressure ◽  
Diffusional Permeability ◽  
Vasa Recta ◽  
Reflexion Coefficient ◽  
The Relationship ◽  
Hydrophilic Solutes ◽  
Water Pathway

Water permeates many microvessel walls via a pathway shared with small hydrophilic solutes and also via an exclusive water pathway. In outer medullary descending vasa recta (OMDVR), the relationship between diffusional permeabilities to water and sodium indicates the existence of an exclusive water pathway and suggests that of a shared pathway. We investigated the latter possibility by estimating hydraulic permeability (Lp) and diffusional permeability to [3H]raffinose (P(raf)) in isolated, perfused OMDVR. The product of hydraulic permeability and osmotic reflexion coefficient of albumin (Lp sigma a) was 1.56 +/- 0.19 x 10(-6) cm.s-1.mmHg-1 (n = 28), calculated from transmural volume fluxes induced by perfusate-to-bath differences in albumin oncotic pressure (delta IIa). P(raf) in the same vessels was 40.1 +/- 7.5 x 10(-5) cm/s when delta IIa was zero. In separate experiments, sigma a was at least 0.89 +/- 0.10 (n = 17). Lp sigma a correlates with P(raf), indicating that OMDVR contain a shared pathway for convection driven by delta IIa and for diffusion of small hydrophilic solutes.

Post-pollination paternal reproductive success in Populus nigra: a male affair

2014 ◽  
Vol 10 (3) ◽  
pp. 565-572
Author(s):  
A. Dowkiw ◽  
N. Chenault ◽  
V. Guérin ◽  
C. Borel ◽  
C. Bastien ◽  
...  
Keyword(s):  
Reproductive Success ◽  
Populus Nigra

Changes in levels of foliar carbohydrates and myo-inositol before premature leaf senescence of Populus nigra induced by a mixture of O3 and SO2

1996 ◽  
Vol 74 (6) ◽  
pp. 965-970 ◽  
Author(s):  
R. C. Fialho ◽  
J. Bücker
Keyword(s):  
Air Pollution ◽  
Leaf Senescence ◽  
Populus Nigra ◽  
Continuous Exposure ◽  
Nonstructural Carbohydrates ◽  
Progressive Decline ◽  
Total Nonstructural Carbohydrates ◽  
Leaf Yellowing ◽  
Premature Leaf Senescence ◽  
Early Indication

Specimens of Populus nigra L. cv. Loenen exhibit premature leaf senescence when exposed for a few weeks to realistic air pollution. In this study, the changes in levels of foliar carbohydrates and myo-inositol (MI) due to 30 ± 1 nL/L O3 + 12 ± 1 nL/L SO2 from the onset of exposure to the occurrence of premature abscission is presented. Petioles and laminae of the 12 oldest leaves were separately analysed on days 0, 4, 8, 12, 16, 20, 22, and 32 of continuous exposure, which was performed in open-top chambers (OTC). On days 8 to 12, clearly prior to yellowing (starting on day 22), total nonstructural carbohydrates (TNC; starch + raffinose + sucrose + glucose + fructose + MI) in the fumigated laminae exceeded that in controls by about 30%. This increase was due to higher amounts of different soluble forms, while starch remained unaltered. From day 20 onwards, the level of TNC in the fumigated laminae progressively fell below that in controls. This decrease was due to a progressive decline in starch, which had started on day 16 and was dominating, although glucose and raffinose increased significantly. In the petioles, starch, sucrose, and glucose decreased because of fumigation with the occurrence of leaf yellowing, while raffinose increased. In contrast, MI in the petioles progressively accumulated directly on exposure until leaf yellowing occurred. The results are discussed in terms of the "general adaption syndrome" of H. Selye (1936. Nature (London), 138: 32). The marked MI response in petioles is concluded to be an early indication of phytorelevant O3 + SO2 pollution. Keywords: air pollution, carbohydrates, myo-inositol, pigments, Populus nigra L., senescence, stress.

Propagation of Thermohaline Anomalies and their predictive potential in the Northern North Atlantic

2021 ◽  
Author(s):  
Helene R. Langehaug ◽  
Pablo Ortega ◽  
Francois Counillon ◽  
Daniela Matei ◽  
Elizabeth Maroon ◽  
...  
Keyword(s):  
Time Scales ◽  
North Atlantic ◽  
Atlantic Water ◽  
The Arctic ◽  
Lead Times ◽  
Band Pass Filter ◽  
Pass Filter ◽  
Predictive Skill ◽  
Prediction Systems ◽  
Water Pathway

<p>In this study we assess to what extent seven different dynamical prediction systems can retrospectively predict the winter sea surface temperature (SST) in the subpolar North Atlantic and the Nordic Seas in the time period 1970-2005. We focus in particular on the region where warm water flows poleward, i.e., the Atlantic water pathway, and on interannual-to-decadal time scales. To better understand why dynamical prediction systems have predictive skill or lack thereof, we confront them with a mechanism identified from observations – propagation of oceanic anomalies from low to high latitudes – on different forecast lead times. This observed mechanism shows that warm and cold anomalies propagate along the Atlantic water pathway within a certain time frame. A key result from this study is that most models have difficulty representing this mechanism, resulting in an overall poor prediction skill after 1-2 years lead times (after applying a band-pass filter to focus on interannual-to-decadal time scales). There is a link, although not very strong, between predictive skill and the representation of the SST propagation. Observational studies demonstrate predictability several years in advance in this region, thus suggesting a great potential for improvement of dynamical climate predictions by resolving the causes for the misrepresentation of the oceanic link. Inter model differences in simulating surface velocities along the Atlantic water pathway suggest that realistic velocities are important to better circulate anomalies poleward, and hence, increase predictive skill on interannual-to-decadal time scales in the oceanic gateway to the Arctic.</p>

Removal of heavy metal ions from aqueous solution using Populus nigra sawdust-based activated carbon

2021 ◽  
Vol 221 ◽  
pp. 239-251
Author(s):  
Syed Muhammad Salman ◽  
Fouzia Kamal ◽  
Muhammad Zahoor ◽  
Muhammad Wahab ◽  
Durr e Shahwar ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Heavy Metal ◽  
Activated Carbon ◽  
Metal Ions ◽  
Heavy Metal Ions ◽  
Populus Nigra
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