Epicuticular wax forms on leaf surfaces of Zizania aquatica

1970 ◽  
Vol 48 (2) ◽  
pp. 201-205 ◽  
Author(s):  
W. R. Hawthorn ◽  
J. M. Stewart
Keyword(s):  
Continuous Light ◽  
Epicuticular Wax ◽  
Experimental Conditions ◽  
Zizania Aquatica ◽  
Leaf Surfaces ◽  
Young Leaves ◽  
Floating Leaves ◽  
Wax Production ◽  
The Relationship ◽  
Floating Leaf

The epicuticular wax forms on the leaves of the three varieties of Zizania aquatica L. were determined from control plants in the field and greenhouse, and served as a reference for interpreting changes in the wax forms of plants grown under different experimental conditions. Short stubby wax rodlets first appeared 15 cm below the water's surface on the portion of the adaxial surface of young leaves which eventually became floating (leaf numbers 4 to 6). Wax rodlets and platelets were present on both surfaces of the aerial leaves (leaf numbers 7 to 12). The relationship between wax appearance and leaf numbers could be varied by manipulating the water level; for as long as water surrounded the permanently submersed leaves or the submerged portions of the floating leaves, wax production was inhibited. Growth under continuous light and constant temperature conditions indicated that factors other than the day–night cycle were responsible for wax ultrastructure.

scholarly journals The Relationship between Resistance Exercise Performance and Ventilatory Efficiency after Beetroot Juice Intake in Well-Trained Athletes

Nutrients ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 1094
Author(s):  
Noemí Serra-Payá ◽  
Manuel Vicente Garnacho-Castaño ◽  
Sergio Sánchez-Nuño ◽  
Lluís Albesa-Albiol ◽  
Montserrat Girabent-Farrés ◽  
...  
Keyword(s):  
Resistance Exercise ◽  
Exercise Test ◽  
Exercise Performance ◽  
Beetroot Juice ◽  
Experimental Conditions ◽  
Double Blind ◽  
Ventilatory Efficiency ◽  
End Tidal ◽  
Oxygen Uptake Efficiency Slope ◽  
The Relationship

The assessment of ventilatory efficiency is critical to understanding the matching of ventilation (VE) and perfusion in the lungs during exercise. This study aimed to establish a causal physiological relationship between ventilatory efficiency and resistance exercise performance after beetroot juice (BJ) intake. Eleven well-trained males performed a resistance exercise test after drinking 140 mL of BJ (~12.8 mmol NO3−) or a placebo (PL). Ventilatory efficiency was assessed by the VE•VCO2−1 slope, the oxygen uptake efficiency slope and the partial pressure of end-tidal carbon dioxide (PetCO2). The two experimental conditions were controlled using a randomized, double-blind crossover design. The resistance exercise test involved repeating the same routine twice, which consisted of wall ball shots plus a full squat (FS) with a 3 min rest or without a rest between the two exercises. A higher weight lifted was detected in the FS exercise after BJ intake compared with the PL during the first routine (p = 0.004). BJ improved the VE•VCO2−1 slope and the PetCO2 during the FS exercise in the first routine and at rest (p < 0.05). BJ intake improved the VE•VCO2−1 slope and the PetCO2 coinciding with the resistance exercise performance. The ergogenic effect of BJ could be induced under aerobic conditions at rest.

scholarly journals STRUCTURE-FUNCTION RELATIONSHIPS IN THE ADIPOSE CELL

1970 ◽  
Vol 46 (2) ◽  
pp. 342-353 ◽  
Author(s):  
Samuel W. Cushman
Keyword(s):  
Electron Microscopy ◽  
Fatty Acids ◽  
Colloidal Gold ◽  
Intracellular Transport ◽  
Nonesterified Fatty Acid ◽  
Experimental Conditions ◽  
Nonesterified Fatty Acids ◽  
Adipose Cell ◽  
Cell Functions ◽  
The Relationship

Pinocytic activity in the adipose cell has been examined by measuring the uptake of colloidal gold. Pinocytic activity occurs in the isolated adipose cell under all experimental conditions; a portion of the vesicular elements of the cell can be identified by electron microscopy as pinocytic in origin. The isolated adipose cell appears to take up serum albumin by pinocytosis. Pinocytic activity in the isolated adipose cell is enhanced by epinephrine, but not by insulin. The relationship between pinocytosis and the metabolic activity of the adipose cell has been studied by measuring simultaneously the uptake of radioactive colloidal gold, the incorporation of 14C-counts from U-glucose-14C into CO2, total lipid, triglyceride glycerol and triglyceride fatty acids, and the release of nonesterified fatty acids in the absence of hormones and in the presence of insulin or epinephrine. Correlations between hormone-produced alterations in lipid metabolism and in pinocytic activity suggest that intracellular nonesterified fatty acid levels are a factor in the regulation of both the cell's pinocytic activity and its metabolism and that pinocytosis in the adipose cell functions in the extracellular-intracellular transport of nonesterified fatty acids.

Muscle Weight Relationship to Serum Proteins, Hemocytes, and Hepatopancreas in the Lobster, Homarus americanus

1967 ◽  
Vol 24 (11) ◽  
pp. 2339-2354 ◽  
Author(s):  
James E. Stewart ◽  
John W. Cornick ◽  
Diane M. Foley ◽  
M. F. Li ◽  
C. M. Bishop
Keyword(s):  
Serum Protein ◽  
Physiological Condition ◽  
Serum Proteins ◽  
Homarus Americanus ◽  
Total Serum Protein ◽  
Total Serum ◽  
Experimental Conditions ◽  
Muscle Weight ◽  
Beef Liver ◽  
The Relationship

Total serum protein values, hemocyte numbers, and muscle weights were determined for 216 intermolt lobsters immediately after their capture, and for 230 others held captive under a variety of dietary and environmental conditions. Average muscle values ranged from approximately 13% to the more normal 20–25% of the live animals' weight, depending upon experimental conditions. The total serum protein up to a level of 55 mg/ml was shown to be a reliable indicator of muscle weights, although the relationship was not identical for all lobster groups. It appeared to be modified chiefly by the areas from which the different groups were taken. Diet was more important than the temperatures (5 to 14 C) in affecting changes in muscle and serum protein values. Starvation caused a greater reduction (50 to 70%) in the size of the hepatopancreas than in the muscle. Histological examination of the hepatopancreatic tissue showed that the lipid content was markedly reduced upon starvation and that a degeneration of this organ was apparent for lobsters fed a beef liver and herring diet. Measurement of serum proteins would appear to be a useful technique in experiments on lobster nutrition and have value, within specified limits, for assessing the physiological condition of wild lobsters.

Relation of blood flow to VO2, PO2, and PCO2 in dog gastrocnemius muscle

1988 ◽  
Vol 255 (5) ◽  
pp. H1004-H1010 ◽  
Author(s):  
D. E. Mohrman ◽  
R. R. Regal
Keyword(s):  
Blood Flow ◽  
Steady State ◽  
Gastrocnemius Muscle ◽  
Muscle Blood Flow ◽  
Carbon Dioxide Tension ◽  
Experimental Conditions ◽  
Muscle Oxygen ◽  
Muscle Oxygen Consumption ◽  
Relationship Of ◽  
The Relationship

We pump-perfused gastrocnemius-plantaris muscle preparations at constant pressure to study the relationship of muscle blood flow (Q) to muscle oxygen consumption (VO2), venous oxygen tension (PVO2), and venous carbon dioxide tension (PVCO2) during steady-state exercise at different rates. Tests were performed under four experimental conditions produced by altering the perfusate blood-gas status with a membrane lung. The consistency of the relationship of Q to other variables was evaluated by statistical analysis of fitted curves. Not one of the above listed variables had the same relationship with Q in all four of the experimental conditions we tested. However, we did find that a consistent relationship existed among Q, PVO2, and PVCO2 in our data. That relationship is well described by the equation (Q-23).[PVO2 - (0.5.PVCO2) - 3] = 105 (when Q is expressed in ml.100 g-1.min-1 and PVO2 and PVCO2 in mmHg). One interpretation of this result is that both PO2 and PCO2 are important variables in the control of blood flow in skeletal muscle the combined influence of which could account for nearly all of the hyperemia response to steady-state muscle exercise.

scholarly journals Plant traits and environment: floating leaf blade production and turnover of waterlilies

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3212 ◽  
Author(s):  
Peter F. Klok ◽  
Gerard van der Velde
Keyword(s):  
Plant Traits ◽  
Vegetation Period ◽  
Leaf Biomass ◽  
Leaf Life Span ◽  
Turnover Rates ◽  
Leaf Production ◽  
Nuphar Lutea ◽  
Nymphaea Alba ◽  
Floating Leaves ◽  
Floating Leaf

Floating leaf blades of waterlilies fulfill several functions in wetland ecosystems by production, decomposition and turnover as well as exchange processes. Production and turnover rates of floating leaf blades of three waterlily species, Nuphar lutea (L.) Sm., Nymphaea alba L. and Nymphaea candida Presl, were studied in three freshwater bodies, differing in trophic status, pH and alkalinity. Length and percentages of leaf loss of marked leaf blades were measured weekly during the growing season. Area and biomass were calculated based on leaf length and were used to calculate the turnover rate of floating leaf blades. Seasonal changes in floating leaf production showed that values decreased in the order: Nymphaea alba, Nuphar lutea, Nymphaea candida. The highest production was reached for Nuphar lutea and Nymphaea alba in alkaline, eutrophic water bodies. The production per leaf was relatively high for both species in the acid water body. Nymphaea candida showed a very short vegetation period and low turnover rates. The ratio Total potential leaf biomass/Maximum potential leaf biomass (P/Bmax) of the three species ranged from 1.35–2.25. The ratio Vegetation period (Period with floating leaves)/Mean leaf life span ranged from 2.94–4.63, the ratio Growth period (Period with appearance of new floating leaves)/Vegetation period from 0.53–0.73. The clear differences between Nymphaea candida versus Nuphar lutea and Nymphaea alba, may be due to adaptations of Nymphaea candida to an Euro-Siberic climate with short-lasting summer conditions.

Phenotypic plasticity in leaves of four species of arctic Festuca (Poaceae)

1995 ◽  
Vol 73 (11) ◽  
pp. 1810-1823 ◽  
Author(s):  
Nicole S. Ramesar-Fortner ◽  
Nancy G. Dengler ◽  
Susan G. Aiken
Keyword(s):  
Phenotypic Plasticity ◽  
Cross Sections ◽  
Leaf Blade ◽  
Growth Traits ◽  
Continuous Light ◽  
Taxonomic Status ◽  
Trichome Density ◽  
Experimental Conditions ◽  
University Of Toronto ◽  
Species Specific

Leaf phenotypic plasticity of 12 morphological, anatomical, and growth traits was investigated using four species of arctic Festuca (F. baffinensis, F. brachyphylla, F. edlundiae, and F. hyperborea). Plants collected around 78°N in the Canadian Arctic Archipelago were grown for 10 weeks at the University of Toronto in growth chambers in continuous light, under four regimes of temperature and moisture. Significant differences were found between leaves at the time of field collection and leaves of the same plant at the end of the experiment in (i) leaf blade length, (ii) surface vestiture, both in trichome density and angle of the trichomes to the blade surface, and (iii) characters seen in leaf cross sections: blade width, rib thickness, and inter-rib thickness. The four species responded similarly to the experimental conditions, indicating that most of these changes represent part of the developmentally inevitable component of plasticity rather than species-specific adaptations. Trichome density was the only characteristic for which species showed different patterns of response, with a unique pattern of response in F. edlundiae. This and certain growth traits support the taxonomic status of this newly recognized species. The significant effects of temperature and to a lesser degree, water treatments on these leaf anatomical traits indicate that they should be used with caution for the purposes of taxonomy and identification. Key words: Festuca, leaf blade anatomy, phenotypic plasticity.

The Effect of Surface Finish on Zinc Whisker Growth

2012 ◽  
Vol 472-475 ◽  
pp. 2756-2759
Author(s):  
Wen Cui ◽  
Shao Jun Qi
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Surface Finish ◽  
Whisker Growth ◽  
Experimental Conditions ◽  
Steel Substrates ◽  
The Relationship ◽  
Rough Surface Finish ◽  
Scanning Electron ◽  
Effect Of Surface

To understand the relationship between surface finish and zinc whisker growth, this study investigated the growth of whiskers on two mild steel substrates of different surface finish by Field Emission Gun Scanning Electron Microscope (FEG SEM). Results show that, under the same experimental conditions, deposits on substrates with a mirror finish grew less whiskers and nodules than substrates with a rough surface finish.

Sign in / Sign up

Export Citation Format

Share Document