scholarly journals Potassium nutrition recover impacts on stomatal, mesophyll and biochemical limitations to photosynthesis in Carya cathayensis and Hickory illinoensis

2018 ◽  
Author(s):  
Chao Shen ◽  
Ruimin Huang ◽  
Yiquan Tang ◽  
Zhengjia Wang
Keyword(s):  
Photosynthetic Capacity ◽  
Dry Weight ◽  
Potassium Deficiency ◽  
Plant Leaves ◽  
Carya Illinoensis ◽  
Potassium Nutrition ◽  
Carya Cathayensis ◽  
Regulation Of Photosynthesis

AbstractPotassium (K) influences the photosynthesis process in a number of ways; However, the mechanism of photosynthetic response to the long-term supply of potassium is not yet clear. Concurrent measurements of gas exchange and chlorophyll fluorescence were made to investigate the effect of potassium nutrition on photosynthetic efficiency and stomatal conductance (gs), mesophyll conductance (gm) in Pecan (Carya illinoensis K.Kock) and Hickory (Carya cathayensis Sarg.) seedlings in a greenhouse. The results show that the photosynthetic capacity of Pecan and Hickory plants was not limited when the leaves had potassium concentrations >1.4% and 1.42% of dry weight. Most of limitation under potassium deficiency were dominated by MCL for Pecan and Hickory. Both cultivars showed remarkable improvement in SL, MCL, J and Vc,max with additional K supplies. However, effect from potassium deficiency on photosynthesis in plant leaves was irreversible. All of SL, MCL, and BL nearly half down with recovery K supply in both species. These results emphasize the important role of potassium on regulation of photosynthesis by three limitations.

Role of Ecklonia radiata (C. Ag.) J. Agardh in determining trace metal availability in coastal waters. I. Total trace metals

1987 ◽  
Vol 38 (3) ◽  
pp. 307 ◽  
Author(s):  
HW Higgins ◽  
DJ Mackey
Keyword(s):  
Trace Metals ◽  
Metal Binding ◽  
Late Summer ◽  
Dry Weight ◽  
Metal Availability ◽  
Metal Binding Sites ◽  
Accumulation Of Metals ◽  
Concentration Factors

No seasonal variations were found in the concentrations of Zn, Cd, Cu, K, Ca, Mg and Na in the kelp E. radiata collected from the marine-dominated Port Hacking estuary on the east coast of Australia. Concentrations of Fe and Mn were about 60% higher in late summer. The relative distributions of all metals between different kelp tissues, however, showed no seasonal variation. Concentration factors (dry weight basis) for trace metals ranged from 2600 for Cu to 68 000 for Fe. With high biomasses common in macroalgal ecosystems, a large proportion of the non-sediment- bound trace metals can be associated with the macroalgae, which therefore act as substantial buffers for these elements. Metal concentration factors (Y, wet wt basis) were related to oceanic residence times (τ) by the equation log Y = -0.69 logτ + 5.4. The distribution of the aikaii and akaline earth metais (K, Ca, Mg and Na) was relativeiy uniform throughout the various kelp tissues. However, concentrations of Fe, Mn, Zn and Cd were significantly higher in the older extremities (holdfast and eroding tip) than in the meristematic region. Although the holdfast also had higher levels of Cu than the meristem, levels were lower in the eroding tip. The results suggest either a slow net intracellular accumulation of metals with time or an increase in potential metal- binding sites as the extremities senesce. Translocation and elimination of surplus metals through the eroding tip or holdfast was thought not to be important in E. radiata as metal concentrations did not differ between live and dead haptera of the holdfast. Likewise, storage of metals in either the holdfast or eroding tip was considered unlikely because of the constant relative tissue distribution throughout the year and lack of metal mobilization during periods of growth. Pretreatment of kelp tissue with an EDTA wash released about 90% of the total Zn and Cd, 25% of the Cu and 7% of the Fe, suggesting that a large proportion of the total kelp Zn and Cd is associated with the apparent free space (AFS). With rapid exchange between seawater and the AFS, E. radiata is therefore not generally useful as a sentinel accumulator species in pollution studies for assessing long term integrated changes of metals in the water column.

scholarly journals PENGGUNAAN MEDIA ALTERNATIVE (DIAPERS) TERHADAP PERTUMBUHAN DAN PRODUKSI TANAMAN CABAI

Jurnal Agrium ◽  
2018 ◽  
Vol 15 (1) ◽  
pp. 34
Author(s):  
Safrizal Safrizal ◽  
Nazimah Nazimah ◽  
Rina Resssi
Keyword(s):  
Dry Weight ◽  
Leaf Length ◽  
Household Waste ◽  
Home Garden ◽  
Root Weight ◽  
Plant Canopy ◽  
Number Of Leaves ◽  
Different Response

Red chili is a major vegetable both in Indonesia and abroad due to its benefits to the needs of nutrition and health through cooking spices. Utilization of home garden yard is an effective way to cultivate pepper plants. On the other hand, every household produces household waste which is difficult to decompose for instance diapers, so that it can cause environmental pollution in long-term. This study was conducted to investigate the role of planting media such as diapers of on chili growth. The results showed that the use of diapers of diapers as planting media gave no significant different to plant height at 1, 4, 7, 10, 13 and 16 week after application.  It also did not increase the number of leaves at the age of 1, 7, 10, 13 and 16 week after application.  There were no changes in leaf length at ages 1, 4, 7, 10 and 16 week after application. It also happened to also its leaf width at ages 1, 4, 7, 10, 13 and 16 week after application and number of branches at ages 1, 4, 7, 13 and 16 week after aplication. However, it showed a significant different to the number of leaves at age 4 week after planting and its leaf length at age 13 week after planting.   The interaction of using diapers as planting media gave significantly different response to root number, root length, wet root weight and plant canopy, and dry weight roots and plant canopy.

scholarly journals On the importance of including vegetation dynamics in Budyko's hydrological model

2007 ◽  
Vol 11 (2) ◽  
pp. 983-995 ◽  
Author(s):  
R. J. Donohue ◽  
M. L. Roderick ◽  
T. R. McVicar
Keyword(s):  
Steady State ◽  
Vegetation Dynamics ◽  
Hydrological Model ◽  
Photosynthetic Capacity ◽  
Rooting Depth ◽  
Run Off ◽  
Vegetation Water ◽  
Operational Activities

Abstract. The Budyko curve describes the patterns observed between between climate, evapotranspiration and run-off and has proven to be a useful model for predicting catchment energy and water balances. In this paper we review the Budyko curve's underlying framework and, based on the literature, present an argument for why it is important to include vegetation dynamics into the framework for some purposes. The Budyko framework assumes catchments are at steady-state and are driven by the macro-climate, two conditions dependent on the scales of application, such that the framework's reliability is greatest when applied using long-term averages (≫1 year) and to large catchments (>10 000 km2). At these scales previous experience has shown that the hydrological role of vegetation does not need to be explicitly considered within the framework. By demonstrating how dynamics in the leaf area, photosynthetic capacity and rooting depth of vegetation affect not only annual and seasonal vegetation water use, but also steady-state conditions, we argue that it is necessary to explicitly include vegetation dynamics into the Budyko framework before it is applied at small scales. Such adaptations would extend the framework not only to applications at small timescales and/or small catchments but to operational activities relating to vegetation and water management.

Long-term incubations experiments: Insights about demethylation and role of methylmercury refractory pools

2020 ◽  
Author(s):  
Carluvy Baptista-Salazar ◽  
Van Liem-Nguyen ◽  
Sofi Jonsson
Keyword(s):  
Natural Waters ◽  
Potential Role ◽  
Sea Water ◽  
Traditional Approach ◽  
Dry Weight ◽  
Natural Environments ◽  
Incubation Experiments ◽  
Key Factor

<p>Methylation and demethylation of mercury (Hg) control the concentrations of monomethylmercury (MeHg) in natural environments, and thus the pool of Hg available for biological uptake and food web biomagnification. Typically, Hg methylation and demethylation are studied in short-term incubation experiments (< 24 h) using isotopically enriched Hg tracers. This approach has been successfully used to e.g. identify environmental hotspots of both of these processes. However, as the tracers are typically added as dissolved Hg complexes, while most ambient inorganic Hg and MeHg in e.g. sediments and soils are adsorbed onto particles, rates are recognised to not reflect true methylation and demethylation rates of ambient Hg. The traditional approach also overlooks the potential existence of refractory MeHg pools, i.e. pools of MeHg not readily available for demethylation. Previous work has, however, indicated the potential role of refractory MeHg concentrations. Jonsson et al. (Nature Com., 2014), for example, suggest up to 70% of the MeHg pool in a brackish sediment system to be in a refractory form. The occurrence of this fraction is also suggested as a key factor mediating MeHg availability in sediments by DiPasquale et al. (Environ. Sci. Technol., 2000).</p><p>We have conducted long-term incubation experiments aiming to quantify refractory MeHg pools. In short, isotopically enriched Hg tracers (Me<sup>201</sup>Hg and <sup>198</sup>Hg, pre-equilibrated with natural waters) were incubated with lake, marsh and brackish sea water sediments and forest soils at a temperature of 10 °C for up to 6 weeks. These samples represent contrasting environments with initial MeHg concentrations ranging from 0.01 to 3.9 ng g<sup>-1</sup> dry weight, and MeHg:Hg ratios of 0.01 to 31%. To quantify refractory pools of MeHg, we will compare steady state concentrations of MeHg:Hg ratios for added MeHg tracer with the MeHg:Hg ratio of ambient Hg. In this presentation, we will discuss the results from this study, as well as the role of refractory MeHg pools.</p>

scholarly journals Evaluation of the Inhibitory Effects of Bavachinin and Bavachin on Human Monoamine Oxidases A and B

2015 ◽  
Vol 2015 ◽  
pp. 1-14 ◽  
Author(s):  
Najla O. Zarmouh ◽  
Elizabeth A. Mazzio ◽  
Faisel M. Elshami ◽  
Samia S. Messeha ◽  
Suresh V. K. Eyunni ◽  
...  
Keyword(s):  
Ethanolic Extract ◽  
Dry Weight ◽  
Therapeutic Agents ◽  
Inhibitory Effects ◽  
Efficiency Ratio ◽  
Early Management ◽  
Mao B ◽  
Mao A

Monoamine oxidase B inhibitors (MAO-BIs) are used in the early management of Parkinson’s disease (PD). Long-term suspected side effects of MAO-B classical inhibitors established the need for safer alternative therapeutic agents. In our study, the flavanone bavachinin (BNN) and its analog bavachin (BVN) found in the seeds ofPsoralea corylifoliaL. ethanolic extract (PCSEE) were investigated for theirhumanMAO-A and MAO-B (hMAO-A andhMAO-B) inhibition. Both PCSEE and BNN effectively reducedhMAO-B activity more thanhMAO-A while BVN had activating effects. BNN showed selectivehMAO-B inhibition (IC50 ~ 8.82 μM) more thanhMAO-A (IC502009;~ 189.28 μM). BNN in the crude extract was determined by HPLC, also validated by TLC showing a yield of 0.21% PCSEE dry weight. BNN competitively inhibitedhMAO-A andhMAO-B, with a lowerhMAO-BKithanhMAO-AKiby 10.33-fold, and reducedhMAO-BKm/Vmaxefficiency ratio to be comparable to the standard selegiline. Molecular docking examination of BNN and BVN predicted an indirect role of BNN C7-methoxy group for its higher affinity, selectivity, and reversibility as an MAO-BI. These findings suggest that BNN, which is known to be a potent PPAR-γagonist, is a selective and competitivehMAO-B inhibitor and could be used in the management of PD.

Abusive head trauma (AHT) outcome at long-term follow-up and the role of elective neurosurgical approach: A report of 22 cases

2013 ◽  
Author(s):  
Francesca Menegazzo ◽  
Melissa Rosa Rizzotto ◽  
Martina Bua ◽  
Luisa Pinello ◽  
Elisabetta Tono ◽  
...  
Keyword(s):  
Head Trauma ◽  
Abusive Head Trauma ◽  
Long Term Follow Up

The Second Start of Transformation in Ukraine?

2014 ◽  
pp. 30-52 ◽  
Author(s):  
L. Grigoryev ◽  
E. Buryak ◽  
A. Golyashev
Keyword(s):  
Economic Growth ◽  
Armed Conflict ◽  
Political Crisis ◽  
Investment Climate ◽  
Institutional Reforms ◽  
Personal Consumption ◽  
Governance Quality ◽  
Political Turmoil

The Ukrainian socio-economic crisis has been developing for years and resulted in the open socio-political turmoil and armed conflict. The Ukrainian population didn’t meet objectives of the post-Soviet transformation, and people were disillusioned for years, losing trust in the state and the Future. The role of workers’ remittances in the Ukrainian economy is underestimated, since the personal consumption and stability depend strongly on them. Social inequality, oligarchic control of key national assets contributed to instability as well as regional disparity, aggravated by identity differences. Economic growth is slow due to a long-term underinvestment, and prospects of improvement are dependent on some difficult institutional reforms, macro stability, open external markets and the elites’ consensus. Recovering after socio-economic and political crisis will need not merely time, but also governance quality improvement, institutions reform, the investment climate revival - that can be attributed as the second transformation in Ukraine.

Sign in / Sign up

Export Citation Format

Share Document