Absorption of Water by the Egg of the Garden Chafer, Phyllopertha Horticola L

1957 ◽  
Vol 34 (2) ◽  
pp. 226-236
Author(s):  
ROGER LAUGHLIN

1. The garden chafer egg absorbs nearly twice its own weight of water in the early stages of the incubation period. 2. The chorion is thin, uniform and elastic, and the surface is covered with granules. Several layers of epembryonic cuticle are added as the embryo develops. These layers are resorbed before hatching takes place. 3. The rate of development, the rate of water uptake and the length of the rapid absorption period are equally affected by temperature. 4. Eggs are most easily desiccated in the rapid absorption period. 5. The yolk of the new-laid egg has an osmotic pressure of about 13 atm. The extra-embryonic fluid of the swollen egg has an osmotic pressure of about 8 atm. 6. Eggs absorb little or no water from sucrose solutions with osmotic pressures of 15 atm. or over. 7. New-laid eggs cannot absorb water from air at 98% relative humidity. Swollen eggs placed in air of this humidity collapse and die.

1969 ◽  
Vol 50 (2) ◽  
pp. 327-333
Author(s):  
F. MORIARTY

1. The pattern of water absorption by eggs of Chorthippus brunneus varies greatly between individuals. 2. The time at which water is absorbed does not have a close relationship with the stage of embryonic development. 3. Water absorption is not essential for prediapause development. 4. Eggs can only undergo blastokinesis and further development, after diapause is broken, if some water has been absorbed. 5. The rate of water loss or gain varies with the osmotic pressure of sodium chloride solutions. 6. Eggs which have started to absorb water appear to become desiccated more rapidly than eggs which have not.


2021 ◽  
Author(s):  
Maria Ángeles Burgos Simón ◽  
Elisabeth Andrews ◽  
Gloria Titos ◽  
Angela Benedetti ◽  
Huisheng Bian ◽  
...  

<p>The particle hygroscopic growth impacts the optical properties of aerosols and, in turn, affects the aerosol-radiation interaction and calculation of the Earth’s radiative balance. The dependence of particle light scattering on relative humidity (RH) can be described by the scattering enhancement factor f(RH), defined as the ratio between the particle light scattering coefficient at a given RH divided by its dry value.</p><p>The first effort of the AeroCom Phase III – INSITU experiment was to develop an observational dataset of scattering enhancement values at 26 sites to study the uptake of water by atmospheric aerosols, and evaluate f(RH) globally (Burgos et al., 2019). Model outputs from 10 Earth System Models (CAM, CAM-ATRAS, CAM-Oslo, GEOS-Chem, GEOS-GOCART, MERRAero, TM5, OsloCTM3, IFS-AER, and ECMWF) were then evaluated against this in-situ dataset. Building on these results, we investigate f(RH) in the context of other aerosol optical and chemical properties, making use of the same 10 Earth System Models (ESMs) and in-situ measurements as in Burgos et al. (2020) and Titos et al. (2021).</p><p>Given the difficulties of deploying and maintaining instrumentation for long-term, accurate and comprehensive f(RH) observations, it is desirable to find an observational proxy for f(RH). This observation-based proxy would also need to be reproduced in modelling space. Our aim here is to evaluate how ESMs currently represent the relationship between f(RH), scattering Ångström exponent (SAE), and single scattering albedo (SSA). This work helps to identify current challenges in modelling water-uptake by aerosols and their impact on aerosol optical properties within Earth system models.</p><p>We start by analyzing the behavior of SSA with RH, finding the expected increase with RH for all site types and models. Then, we analyze the three variables together (f(RH)-SSA-SAE relationship). Results show that hygroscopic particles tend to be bigger and scatter more than non-hygroscopic small particles, though variability within models is noticeable. This relationship can be further studied by relating SAE to model chemistry, by selecting those grid points dominated by a single chemical component (mass mixing ratios > 90%). Finally, we analyze model performance at three specific sites representing different aerosol types: Arctic, marine and rural. At these sites, the model data can be exactly temporally and spatially collocated with the observations, which should help to identify the models which exhibit better agreement with measurements and for which aerosol type.</p><p> </p><p>Burgos, M.A. et al.: A global view on the effect of water uptake on aerosol particle light scattering. Sci Data 6, 157. https://doi.org/10.1038/s41597-019-0158-7, 2019.</p><p>Burgos, M.A. et al.: A global model–measurement evaluation of particle light scattering coefficients at elevated relative humidity, Atmos. Chem. Phys., 20, 10231–10258, https://doi.org/10.5194/acp-20-10231-2020, 2020.</p><p>Titos, G. et al.: A global study of hygroscopicity-driven light scattering enhancement in the context of other in-situ aerosol optical properties, Atmos. Chem. Phys. Discuss. [preprint], https://doi.org/10.5194/acp-2020-1250, in review, 2020.</p>


1965 ◽  
Vol 11 (3) ◽  
pp. 531-538 ◽  
Author(s):  
J. S. Jhooty ◽  
W. E. McKeen

The conidia of Sphaerotheca macularis germinate best at a relative humidity (R.H.) of 99 and 100% on glass surfaces, and germination does not occur if the R.H. is below 93%. Conidia of Erysiphe polygoni DC. germinate at 3% R.H. The water content of conidia of S. macularis and E. polygoni is 53 and 69% respectively. The osmotic pressure of S. macularis conidia is about 18 atm and their density varies from 1.10 to 1.11 g/ml. There is no significant change in the diameter and length of the conidia during germination.


1968 ◽  
Vol 46 (3) ◽  
pp. 469-473 ◽  
Author(s):  
G. R. F. Davis

Oryzaephilus surinamensis (L.), reared on three holidic diets at 32 ± 2 °C and 75 ± 5% relative humidity, required a dietary source of phenylalanine, irreplaceable by dietary tyrosine. This insect also required a dietary source of tyrosine for normal rate of development. On diets containing 1.0 mg of phenylalanine per gram, it used supplementary glycine more effectively than supplementary tyrosine as a replacement for phenylalanine omitted from the diet. On diets containing 1.0 mg of tyrosine per gram, it used supplementary phenylalanine more effectively than glycine. Emergent adults weighed less with 1.0 mg of dietary phenylalanine per gram than with higher concentrations. Adult weight was unaffected by decreasing concentrations of dietary tyrosine.


Tellus ◽  
1979 ◽  
Vol 31 (6) ◽  
pp. 478-486 ◽  
Author(s):  
GOTTFRIED HÄNEL ◽  
BRIGITTE ZANKL

2016 ◽  
Vol 93 (4) ◽  
Author(s):  
Yuki Fukatani ◽  
Daniel Orejon ◽  
Yutaku Kita ◽  
Yasuyuki Takata ◽  
Jungho Kim ◽  
...  

Plant Methods ◽  
2019 ◽  
Vol 15 (1) ◽  
Author(s):  
Beatriz Fernández-Marín ◽  
Othmar Buchner ◽  
Gerald Kastberger ◽  
Federica Piombino ◽  
José Ignacio García-Plazaola ◽  
...  

Abstract Background Non-invasive procedures for the diagnosis of viability of plant or fungal tissues would be valuable for scientific, industrial and biomonitoring purposes. Previous studies showed that infrared thermography (IRT) enables non-invasive assessment of the viability of individual "orthodox" (i.e. desiccation tolerant) seeds upon water uptake. However, this method was not tested for rehydrating tissues of other desiccation tolerant life forms. Furthermore, evaporative cooling could obscure the effects of metabolic processes that contribute to heating and cooling, but its effects on the shape of the "thermal fingerprints" have not been explored. Here, we further adapted this method using a purpose-built chamber to control relative humidity (RH) and gaseous atmosphere. This enabled us to test (i) the influence of relative humidity on the thermal fingerprints during the imbibition of Pisum sativum (Garden pea) seeds, (ii) whether thermal fingerprints can be correlated with viability in lichens, and (iii) to assess the potential influence of aerobic metabolism on thermal fingerprints by controlling the oxygen concentration in the gaseous atmosphere around the samples. Finally, we developed a method to artificially "age" lichens and validated the IRT-based method to assess lichen viability in three lichen species. Results Using either 30% or 100% RH during imbibition of pea seeds, we showed that "live" and "dead" seeds produced clearly discernible "thermal fingerprints", which significantly differed by > |0.15| °C in defined time windows, and that RH affected the shape of these thermal fingerprints. We demonstrated that IRT can also be used to assess the viability of the lichens Lobaria pulmonaria, Pseudevernia furfuracea and Peltigera leucophlebia. No clear relationship between aerobic metabolism and the shape of thermal fingerprints was found. Conclusions Infrared thermography appears to be a promising method for the diagnosis of viability of desiccation-tolerant tissues at early stages of water uptake. For seeds, it is possible to diagnose viability within the first hours of rehydration, after which time they can still be re-dried and stored until further use. We envisage our work as a baseline study for the use of IR imaging techniques to investigate physiological heterogeneity of desiccation tolerant life forms such as lichens, which can be used for biomonitoring, and for sorting live and dead seeds, which is potentially useful for the seed trade.


2017 ◽  
Author(s):  
Xiaowei Wang ◽  
Bo Jing ◽  
Fang Tan ◽  
Jiabi Ma ◽  
Yunhong Zhang ◽  
...  

Abstract. Although water uptake of aerosols plays an important role in the atmospheric environment, the effects of interactions between components on chemical composition and hygroscopicity of aerosols are still not well constrained. The hygroscopic properties and phase transformation of oxalic acid (OA) and mixed particles composed of ammonium sulfate (AS) and OA with different organic to inorganic molar ratios (OIRs) have been investigated by using confocal Raman spectroscopy. It is found that OA droplets first crystallize to form oxalic acid dihydrate at 77 % relative humidity (RH), and further lose crystalline water to convert into anhydrous oxalic acid around 5 % RH during the dehydration process. The deliquescence and efflorescence point for AS is determined to be 80.1 ± 1.5 % RH and 44.3 ± 2.5 % RH, respectively. The observed efflorescence relative humidity (ERH) for mixed OA/AS droplets with OIRs of 1:3, 1:1 and 3:1 is 34.4 ± 2.0 % RH, 44.3 ± 2.5 % RH and 64.4 ± 3.0 % RH, respectively, indicating the elevated OA content appears to favor the crystallization of mixed systems at higher RH. However, the partial deliquescence relative humidity (DRH) for mixed OA/AS particles with OIR of 1:3 and 1:1 is observed to occur at 81.1 ± 1.5 % RH and 77 ± 1.0 % RH, respectively. The Raman spectra of mixed OA/AS droplets indicate the formation of ammonium hydrogen oxalate (NH4HC2O4) and ammonium hydrogen sulfate (NH4HSO4) from interactions between OA and AS in aerosols after slow dehydration process in the time scale of hours, which considerably influence the subsequent deliquescence behavior of internally mixed particles with different OIRs. The mixed OA/AS particles with 3:1 ratio exhibit no deliquescence transition over the RH range studied due to the considerable transformation of (NH4)2SO4 into nonhygroscopic NH4HC2O4. Although the hygroscopic growth of mixed OA/AS droplets is comparable to that of AS or OA at high RH during the dehydration process, Raman growth factors of mixed particles after deliquescence are substantially lower than those of mixed OA/AS droplets during the efflorescence process and further decrease with elevated OA content. The discrepancies for Raman growth factors of mixed OA/AS particles between the dehydration and hydration process at high RH can be attributed to the significant formation of NH4HC2O4 and residual OA, which remain solid at high RH and thus result in less water uptake of mixed particles. These findings improve the understanding of the role of reactions between dicarboxylic acid and inorganic salt in the chemical and physical properties of aerosol particles, and might have important implications for atmospheric chemistry.


1981 ◽  
Vol 44 (10) ◽  
pp. 736-741 ◽  
Author(s):  
AHMED E. YOUSEF ◽  
ELMER H. MARTH

Two media [basal (M1) and enriched (M2)] containing potassium sorbate (0–300 ppm as sorbic acid) were inoculated with spores (104 – 106/flask) of Aspergillus parasiticus and incubated for 5 days at 28 C. The greater the amount of sorbate added, the higher was the pH of the media after incubation and the smaller was the yield of mold mycelium. Intermediate amounts of sorbate sometimes resulted in greater accumulation of aflatoxin than when media were free of sorbate. Sorbate more effectively inhibited mold growth and aflatoxin production in medium M2 than M1 and when the small rather than the large inoculum was used. A second trial was done with 106 or 105 spores/flask of M2 (ca. 27 ml) and 105 spores/flask of M2 (ca. 27 ml) containing sorbate (200 ppm of sorbic acid). Cumulative data for mold growth. pH and content of aflatoxin in the medium showed that relative effects of different treatments changed during the incubation period. An index to measure the capacity of molds to synthesize aflatoxins was developed. Application of the index indicates that sorbate delayed mold growth but did not inhibit biosynthesis of aflatoxin. The ability to synthesize aflatoxin was greatest in the early stages of mold growth and then decreased linearly as mold growth progressed.


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