scholarly journals Water Sorption and Desorption of Isolated Cuticles From Three Woody Species With Focus on Ilex aquifolium

2021 ◽  
Vol 12 ◽  
Author(s):  
Clara Vega ◽  
María Valbuena-Carabaña ◽  
Luis Gil ◽  
Victoria Fernández

The cuticle is a lipid-rich layer that protects aerial plant organs against multiple stress factors such as dehydration. In this study, cuticle composition and structure in relation to water loss are examined in a broad ecophysiological context, taking into consideration leaf age and side from Ilex aquifolium (holly) in comparison with Eucalyptus globulus (eucalypt) and Prunus laurocerasus (cherry laurel). Enzymatically isolated cuticular membranes from holly leaves were studied under three treatment conditions: natural (no chemical treatment), after dewaxing, and after methanolysis, and the rate of water loss was assessed. Structural and chemical changes were evaluated using different microscopy techniques and by Fourier transform infrared (FTIR) spectroscopy. The potential mechanisms of solute absorption by holly leaves were additionally evaluated, also testing if its prickly leaf margin may facilitate uptake. The results indicate that the treatment conditions led to structural changes, and that chemical composition was hardly affected because of the occurrence of cutan. Structural changes led to more hydrophilic adaxial surfaces, which retained more water and were more efficient than natural cuticles, while changes were not significant for abaxial surfaces. Across natural cuticles, age was a significant factor for eucalypt but not for holly. Young eucalypt cuticles were the group that absorbed more water and had the lowest water loss rate. When comparing older leaf cuticles of the three species, cherry laurel was found to absorb more water, which was, however, lost more slowly, compared with the other species. Evidence was gained that holly leaves can absorb foliar-applied solutes (traced after calcium chloride application) through the adaxial and abaxial surfaces, the adaxial mid veins, and to a lower extent, the spines. In conclusion, for the species examined, the results show variations in leaf cuticle composition and structure in relation to leaf ontogeny, and water sorption and desorption capacity.

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ben R. Cairns ◽  
Benjamin Jevans ◽  
Atchariya Chanpong ◽  
Dale Moulding ◽  
Conor J. McCann

AbstractNeuronal nitric oxide synthase (nNOS) neurons play a fundamental role in inhibitory neurotransmission, within the enteric nervous system (ENS), and in the establishment of gut motility patterns. Clinically, loss or disruption of nNOS neurons has been shown in a range of enteric neuropathies. However, the effects of nNOS loss on the composition and structure of the ENS remain poorly understood. The aim of this study was to assess the structural and transcriptional consequences of loss of nNOS neurons within the murine ENS. Expression analysis demonstrated compensatory transcriptional upregulation of pan neuronal and inhibitory neuronal subtype targets within the Nos1−/− colon, compared to control C57BL/6J mice. Conventional confocal imaging; combined with novel machine learning approaches, and automated computational analysis, revealed increased interconnectivity within the Nos1−/− ENS, compared to age-matched control mice, with increases in network density, neural projections and neuronal branching. These findings provide the first direct evidence of structural and molecular remodelling of the ENS, upon loss of nNOS signalling. Further, we demonstrate the utility of machine learning approaches, and automated computational image analysis, in revealing previously undetected; yet potentially clinically relevant, changes in ENS structure which could provide improved understanding of pathological mechanisms across a host of enteric neuropathies.


2020 ◽  
Vol 65 (No. 8) ◽  
pp. 281-294
Author(s):  
Jansller Genova ◽  
Antonio Melo ◽  
Paulo Rupolo ◽  
Silvana Carvalho ◽  
Leandro Costa ◽  
...  

Weaning is considered the “critical window” in the piglet’s life because it is associated with several stress factors, such as loss of contact with the mother and original litter, solid diet, environmental and structural changes, and the establishment of a new hierarchy. During this abrupt period, several events such as reduced feed intake, high morbidity, susceptibility to enteric infections and post-weaning diarrhoea are observed. The nutritional landscape of the piglet gut is modified, which can compromise the maturity of the gastrointestinal system, the stable intestinal microbiome and the active immunity developed as an indicator of intestinal health. However, with increased awareness of feed safety issues and the development of drug-resistant bacteria, the interest in producing pigs without the use of antimicrobial growth promoters (AGP) is increasing, since long-term use and therapeutic doses of AGP can contribute to the reduction of bacterial diversity and increase of inflammatory bowel disease (IBD). Thus, the most widely researched alternatives include the use of feed additives, feeding strategies, nutraceuticals/functional foods and available handling that can reduce the risk of IBD beyond basic nutritional functions. Studies have reported intestinal alkaline phosphatase as a new nutritional therapy associated with intestinal health which may be a “key additive” in the AGP replacement. In this review article, the purpose is to show some current aspects of feed additive research, addressing a concept of the “intestinal health” from different points of view and properties of alkaline phosphatase.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
M. Dolbeth ◽  
O. Babe ◽  
D. A. Costa ◽  
A. P. Mucha ◽  
P. G. Cardoso ◽  
...  

AbstractMarine heatwaves are increasing worldwide, with several negative impacts on biological communities and ecosystems. This 24-day study tested heatwaves' effect with distinct duration and recovery periods on benthic estuarine communities' diversity and contribution to ecosystem functioning experimentally. The communities were obtained from a temperate estuary, usually subjected to high daily thermal amplitudes. Our goal was to understand the communities' response to the thermal change, including the community descriptors and behavioural changes expected during heat extremes. We measured community composition and structural changes and the bioturbation process and nutrient release as ecosystem functioning measurements. Overall, our findings highlight the potential tolerance of studied estuarine species to the temperature ranges tested in the study, as community composition and structure were similar, independently of the warming effect. We detected a slight trend for bioturbation and nutrient release increase in the communities under warming, yet these responses were not consistent with the heatwaves exposure duration. Overall, we conclude on the complexity of estuarine communities’ contribution to functioning under warming, and the importance of scalable experiments with benthic organisms' responses to climate variability, accommodating longer time scales and replication. Such an approach would set more efficient expectations towards climate change mitigation or adaptation in temperate estuarine ecosystems.


2014 ◽  
Vol 1020 ◽  
pp. 823-826
Author(s):  
G.Sh. Hovsepyan ◽  
M.A. Kalantaryan ◽  
T.V. Yedoyan

The aim of this paper is to study the possibility of expanded obsidian and its modified product use for oil sorption, in that tetraethoxisilane (TEOS) has been used as a modifier. The optimal concentration of the modifier was determined by 50 per cent weight of expanded obsidian. The expanded obsidian was previously activated with 0,1 M solution of hydrochloric acid. IR spectrometry was used to characterise structural changes in the modified expanded obsidian samples. To determine water sorption capacity a series of experiments has been carried out. The analysis of obtained experimental data showed that after surface modification of expanded obsidian water capacity is reduced 3 times after the surface modification of EO.


1988 ◽  
Vol 68 (4) ◽  
pp. 975-982 ◽  
Author(s):  
J. M. CLARKE ◽  
R. A. RICHARDS

Water loss at minimum stomatal aperture (residual transpiration) from plant surfaces accounts for a substantial proportion of total transpiration during periods of water stress and at night. Its reduction by genetic selection has been suggested as a desirable objective in water-limited environments. To identify genetic and environmental sources of variation in residual transpiration of wheat (Triticum spp.), the effects of glaucousness, epicuticular wax, leaf age, plant height, and growth environment were determined using excised leaves. Glaucousness reduced residual transpiration by an average of 10%. Differing quantities of epicuticular wax and glaucousness in an isogenic pair of genotypes affected residual transpiration as well, the rate being 33% greater in the low wax, nonglaucous than in the high wax, glaucous line. Residual transpiration rate of flag leaves of field-grown plants increased with leaf age, particularly during the 7 d following ligule appearance. The rate of residual transpiration was greater in tall than in dwarf near-isogenic lines. Residual transpiration of leaves from plants grown in glasshouses was 44–66% lower than that of plants grown outdoors, which had a mean rate of 2.68 × 10−5 g H2O cm−2 min−1. Method of water application to glasshouse plants influenced residual transpiration rate. The rate for leaves of plants watered by spraying water onto the plant and soil surface was 20% greater than that of leaves of plants watered on the soil surface only. It was concluded that the increase in residual transpiration rate with leaf age was due to duration of exposure to the rigors of the exterior environment; the absence of this in controlled environments results in lower rates of residual transpiration than in the field.Key words: Cuticular transpiration, Triticum aestivum L., Triticum turgidum L. var. durum, wheat


2020 ◽  
Vol 11 (514) ◽  
pp. 282-287
Author(s):  
I. V. Nagorna ◽  
◽  
Y. Y. Halkina ◽  

The article is aimed at finding ways to optimize costs at the production subdivision «Operational wagon depot Kupyansk» of the Regional division «Southern Railway» of the Private Joint Stock Company «Ukrainian Railways» on the basis of the performed analysis of the composition and structure of costs, profitability, the impact of the amount of costs on performance indicators, the level of costs per 1 UAH of the consummated services, and operational analysis. The views of scholars on the term «costs» are explored. It is defined that cost management is quite a complex and important process in the course of carrying out economic activity along with determining the quality of further results of enterprise. The main methodological bases of cost management, economic condition of the enterprise are researched. Optimization measures for further development of the enterprise are proposed, which will allow to use its resources more efficiently, to achieve an increase sales and maximize profits. The authors provide recommendations on managing the enterprise costs in order to stimulate the growth of competitiveness. The focus is placed on the mechanism of minimizing the costs of the enterprise in the total amount of net income, because efficient use of costs can not be carried out without structural changes in the sphere of their management. It is identified that cost management is an interconnected complex of works, which forms and influences the behavior of costs during economic activity, as well as is aimed at achieving the optimal level of costs. The proposed measures as to optimizing costs can be used by directors and managers of the enterprise to make informed decisions on the prospective development of the enterprise.


Author(s):  
Jitka Langová ◽  
Donludee Jaisut ◽  
Ratiya Thuwapanichayanan ◽  
Charotorn Phowong ◽  
Jiří Štencl ◽  
...  

Water sorption tests of Roselle (Hibiscus sabdariffa L.) carried out under laboratory conditions are presented together with mathematical analyses of the moisture sorption isotherms (MSI’s). Moisture equilibrium data for adsorption and desorption of water from Roselle powder were investigated at near ambient air temperatures in the range of 5 and 35 °C and water activity (Aw) ranging from 0.11 to 0.97. The manometric method has been used for water sorption tests. Models for MSI’s are exponential equations. Coefficients of determination are 0.998 and 0.996 (for adsorption and desorption at 5 °C, respectively), 0.998 and 0.999 (for adsorption and desorption at 20 °C, respectively), and 0.998 and 0.999 (for adsorption and desorption at 35 °C, respectively). The equilibrium moisture content (EMC) of Roselle samples increased with an increase of Aw at a constant temperature both for adsorption and desorption. Adsorption curve equates to desorption curve at higher temperatures of tests carried out. Critical values of EMC of samples tested corresponding to the Aw equal to 0.6 were between 13.401% moisture content wet basis (MC w.b.) and 15.934% MC (w.b.) for moisture adsorption and desorption, respectively. These values are useful for storing conditions optimisation from point of view microorganisms grow and structural changes analyses. Crystal structure changes were observed during adsorption and desorption in the microscope, too. It was found out glass transition in dependence on the water content of samples tested.


2005 ◽  
Vol 53 (1) ◽  
pp. 45 ◽  
Author(s):  
Christine Stone ◽  
Laurie Chisholm ◽  
Simon McDonald

Leaf chlorophyll content is influenced directly by many environmental stress factors. Because leaf pigment absorption is wavelength dependent, numerous narrow-band reflectance-based indices have been proposed as a means of assessing foliar health and condition. Chlorophyll content, however, also varies with leaf developmental stage. In this study, a range of morphological and physiological traits including insect damage, relative chlorophyll content (SPAD values), chlorophyll fluorescence (Fv/Fm) and reflectance spectra was measured of leaves sampled from mature Eucalyptus saligna. Relative differences among three leaf-age cohorts were compared with differences obtained from mature leaves that were either healthy or infested with the psyllid Glycaspis baileyi. Differences in relative chlorophyll content were greater between immature and mature foliage than between damaged and healthy mature leaves. These differences were confirmed in the comparisons of reflectance spectra and indices. As many eucalypt species have opportunistic crown phenology and long-lived leaves, leaf-age composition of crowns needs to be taken into account when applying reflectance-based indices to assess foliar condition of eucalypts.


2021 ◽  
Vol 12 ◽  
Author(s):  
Arkadiusz Urbański ◽  
Karolina Walkowiak-Nowicka ◽  
Grzegorz Nowicki ◽  
Szymon Chowański ◽  
Grzegorz Rosiński

Environmental conditions, especially related to winter, are crucial for shaping activity of insect immune system. However, our previous research clearly indicates differences in the immune system functioning when the cold stress was induced in the laboratory conditions and when the beetles were collected from natural environment during winter. This is probably related to the multiplication of observed effects by simultaneous presence of different stress factors characteristic of winter, including desiccation. For these reasons, our next step was analysis of the effects of short-term desiccation and recovery time on the functioning of immune system of burying beetle Nicrophorus vespilloides. Also, the effect of Tenmo–PVK-2 (tenebrionid periviscerokinin), member of the CAPA–PVK neuropeptide family, was investigated to better understand observed changes. Short-term desiccation decreases the phagocytic activity of burying beetle haemocytes, which is correlated with a reduction in their adhesive ability. On the other hand, there was a significant increase in phenoloxidase (PO) activity and the level of proPO expression, which may suggest sealing the cuticula by melanin deposition and prevention of water loss. Additionally, the elevated level of defensin expression may be associated with the cross-talk between mechanisms, which participate in insect response to environmental stress, including pathogen infection. After 1 h of recovery time, the activity of tested cellular and humoral mechanisms was mostly back to the control level. However, inhibition of the activity of PO and down-regulation of proPO were noted. These results also indicate importance of melanin deposition during water loss. Moreover, it suggests that some changes in immune system functioning during stress conditions do not have an immune function. Interestingly, part of the effects characteristic of recovery time were also observed after the application of Tenmo–PVK-2, mainly related to haemocyte morphology. These results indicate that CAPA–PVK neuropeptides may also influence on activity of burying beetle immune system. It should be also highlighted that, because of the study of the effects of CAPA–PVK neuropeptides, homologs of vertebrate neuromedin U, the results may be interesting for search evolutionary similarities in the functioning of the neuroendocrine system of insects and vertebrates.


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