Authors:Nevena Popovic, Bernard Fried, and Joseph Sherma
Biomphalaria glabrata snails were infected with Schistosoma mansoni and maintained at different dilutions of artificial ocean water for up to 4 weeks. Glucose and maltose concentration of the digestive gland-gonad complex were analyzed by high-performance thin-layer chromatography at different stages of the infection. B. glabrata snails were divided into three experimental groups: Group A, snails with early prepatent infection (10 days post-infection); Group B, snails with late prepatent infection (22 days post-infection); and Group C, snails with patent infection (45 days post-infection). Infected snails in A were maintained at different salinities for 2 weeks and then necropsied, and their two main simple sugars, i.e., glucose and maltose, were analyzed. Groups B and C contained two subgroups: the first subgoups were analyzed after 2 weeks, and the second after 4 weeks. Controls for these experiments were maintained identically in either deionized water or artificial spring water. Maltose and glucose were extracted from the digestive gland-gonad complex in ethanol-water (70:30). 1-Butanol-glacial acetic acid-diethyl ether-deionized water (27:18:5:3) mobile phase was used to separate sugars on EMD Millipore silica gel preadsorbent plates. Sugars were detected using α-naphthol-sulfuric acid reagent and quantified with a CAMAG TLC Scanner 3 at 515 nm. The obtained data were compared using analysis of variance (ANOVA) single factor statistical analysis. Statistical differences were not found in any sugars in Group A snails. For glucose, a significant difference was found after 4 weeks in both B and C snails. For maltose, a significant difference was found after 4 weeks in B snails and after 2 weeks in C snails. Different salinity levels affect the maltose and glucose concentrations of adult B. glabrata snails infected with S. mansoni.
Biological Development Co., Ltd. (purity: ∼99%). Saline (medical), Glucose (medical).
Equipment and conditions
Thermoanalyzer Systems (American Thermoanalyzer Companies Inc.) were used for determining the DSC–TG curves of
An establishéd electrodeposition method for separating americium and plutonium from highly saline used-fuel-leaching solutions has been extended to the determination of Np and U in saline groundwaters. The interference of major ionic species in groundwater on the yield was investigated using three groundwaters of varying salinity (ionic strength I=1.37, 0.0748 and 0.0253 mol/l). High average yields (>92%), and good reproducibility were obtained for Np and U electroplated from solutions with ionic strength less than 0.1. The greatest interferences from individual ions were caused by Mg2+ and HCO
The statistical analysis of salinity data from
samples collected yearly from genetic soil horizons of 69 points of the
Hungarian Soil Information and Monitoring System between 1992 and 2000 showed
changes in time. There is a strong atmospheric control over the groundwater
level and the resulting soil salinity. Weak statistical association was
established between either the pattern of yearly soil salinity changes in the
second (10-20 cm) and third (30-40 cm) genetic horizon and the groundwater
observation stations or the soil types. In the area of Kecskemét there was a
tendency of decreasing soil salinity patterns, while around Békéscsaba a
tendency of increasing soil salinity patterns, as illustrated by the
correspondence biplot. Regarding soil types, the solonetzic meadow soil showed
a tendency of increasing salinity. It was concluded that the statistical
analyses of the monitored data must be carefully planned in order to provide
the optimal background data as independent data from all those available to
accompany the monitored soil data as dependent variable.
Authors:Nalinda Almeida, Stanley Hirschi, Anja Mueller, and Leela Rakesh
Viscoelastic properties of κ-carrageenan in saline solution at various concentrations and pH were investigated by dynamic
rheological techniques, viscosity, elasticity measurements, and IR spectrometry. The viscosity and elasticity at low concentrations
of κ-carrageenan do not depend on pH, confirming that κ-carrageenan is in a disordered conformation. At 0.7% κ-carrageenan,
the disordered confirmation transforms into an ordered helical confirmation with the possibility of weak-type gel formation.
The transformation is also confirmed by dynamic measurements of loss and storage moduli. Furthermore, at this concentration,
the viscosity and elasticity are highly dependent on pH. At higher concentrations of NaCl (0.5 M) at some pHs, we observed
that storage moduli is greater than loss moduli for the entire frequency region. Hence, there is a possibility of structure
transformation from weak-type gel to a somewhat intermediate gel. The lowest viscosity and elasticity were obtained at extreme
pH, confirming that there are structural changes occurring at these pHs due to hydrolysis. This is confirmed by IR data.
A method for the determination of uranium and 210Po in high salinity water samples has been elaborated. Both radionuclides are preconcentrated from 0.5 dm3 saline media by co-precipitation with hydrated manganese dioxide, followed by dissolution of the precipitate in 200 mL of
1 M HCl. Uranium isotopes 235U and 238U can be directly determined by ICP MS method with a detection limit of 0.01 ppb for 238U. Prior to a selective determination of 210Po, the majority of other naturally occurring α-emitting radionuclides (uranium, thorium and protactinium) can be stripped
from this solution by their extraction with a 50% solution of HDEHP in toluene. Finally, 210Po is simply separated by direct transfer to an extractive scintillator containing 5% of trioctylphosphine oxide in Ultima
Gold F cocktail and determined by an α/β separation liquid scintillation technique with detection limit below 0.1 mBq/dm3.
Clays high in Mg content occur frequently in the high saline environment of salt lakes in southern Tunisia. The DTA curves
of these clays show a striking endothermic-exothermic reaction in the temperature range of 800–820�C. A strong correlation
is observed between the intensity of these coupled reactions and the Mg content of the initial clay sample. The initial endothermic
reaction is interpreted as the melting/dehydroxylation of the Mg-bearing smectites. The subsequent exothermic peak is interpreted
as caused by the crystallisation of the new Mg-silicate phase enstatite. Therefore, the DTA is considered as a suitable method
for the identification and relative quantification of high Mg clay minerals (e.g. trioctahedral smectites). Variations of
the Mg content of the studied samples were well detectable by means of DTA, disclosing a distinct distribution pattern of
the salt lake clays. Clues to bulk chemical composition of the initial clay assemblage can also be found in the results of
the X-ray analysis of the firing products.
A simple method for the determination of trace concentrations of metals in saline water is described. The analytical procedure
involves the separation of metal ions of Cu, Zn, Hg and Fe by precipitation with diethyldithiocarbamate (DDTC). The radioisotope
X-ray fluorescence method using Si(Li) detector has been applied for the determination of metal ions closed in the DDTC deposition.
hydrogeologically closed Carpathian Basin
particular importance in the salinization/alkalization processes. In the
poorly-drained low-lying areas the capillary flow transports high amounts of
water soluble salts from the shallow, „stagnant” groundwater with high salt
concentration and unfavourable sodium-carbonate(bicarbonate) type ion
composition to the overlying soil horizons. Due to the strongly alkaline soil
solution, the Ca and Mg salts (mostly carbonates and bicarbonates) are not
soluble and Na
became absolutely predominant in the migrating soil
solution which leads to high ESP even at relatively low salt concentration.
saturation of heavy-textured soils with high amount of
expanding clay minerals results in unfavourable physical-hydrophysical
extreme moisture regime
of these soils, which are their
main ecological constrains and the limiting factors of their fertility,
productivity and agricultural utility. The simultaneous hazard of waterlogging
or overmoistening, and drought sensitivity in extensive lowland areas,
sometimes in the same places within a short period, necessitates a precise,
“double function” soil moisture control against their harmful
ecological/economical/social consequences. Most of the environmental constrains
(including salinity/alkalinity/sodicity) can be efficiently controlled:
prevented, eliminated, or - at least - moderated. But this needs permanent care
and proper actions: adequate soil and water conservation practices based on a
comprehensive soil/land degradation assessment. It includes continuous
registration of facts and changes (monitoring); exact and quantitative knowledge
on the existing soil processes, their influencing factors and mechanisms.