The effect of dehydration and rehydration on salt loss in the second-stage larvae of Anguina tritici

Parasitology ◽  
1981 ◽  
Vol 82 (3) ◽  
pp. 411-419 ◽  
Author(s):  
C. Womersley

SUMMARYThe effect of repeated dehydration and hydration on the salt content of 2nd-stage larvae of Anguina tritici was studied. The sodium, potassium, magnesium and calcium contents of the larvae after subjection to varying periods of desiccation and rehydration were determined with atomic absorption spectrophotometry and flame photometry. External cation concentrations on the cuticle of the head, middle body and tail regions were determined semi-quantitatively with scanning electron microscopy in conjunction with X-ray analysis (EDAX). Salt concentrations decreased with each dehydration/rehydration cycle. The greatest loss occurred on revival from the first desiccation period. The results indicated that A. tritici was incapable of regulating it's internal sodium content during revival, but suggested a limited ability to control potassium, magnesium and calcium loss. Salt loss through the nematode cuticle was restricted to potassium and calcium during desiccation. The salt losses encountered are discussed in relation to nematode osmoregulation and to the survival of the nematode in the anhydrobiotic state.

2020 ◽  
Vol 71 (2) ◽  
pp. 196-201
Author(s):  
Erika Reisz ◽  
Corneliu-Mircea Davidescu ◽  
Radu Ardelean ◽  
Liviu Costea

The purpose of this article is to study the activation of the Mir�id volcanic tuff with NaOH solutions at various concentrations. To be more specific, the work investigated the evolution of the concentrations of species that passed from the tuff into the activating solutions and the quantities of dissolved species from 100 g tuff. The species found in the activating solution were: potassium, magnesium, aluminium and silicon. The shape of the curves - a sudden increase followed by a plateau or a second stage of slower increase - allowed for setting up the optimal activation time at a half-hour. Another finding was the optimal concentration of 1 N for the activating solution. X-ray diffractograms showed the increase of clinoptilolite content in the tuff, thus improving the adsorbent as well as ion exchange properties by activation with NaOH solutions.


Fisheries ◽  
2021 ◽  
Vol 2021 (1) ◽  
pp. 103-107
Author(s):  
Ekaterina Konopleva ◽  
Liubov Abramova ◽  
Valeria Gershunskaya ◽  
Maksim Arnautov

The aim of the work was to develop the parameters of the process of salting Pacific herring fillet with a reduced salt content, intended for children’s nutrition. For salting, food salt with a reduced sodium content, enriched with potassium, magnesium, was used. Based on the conducted studies, a rational formulation of the salting mixture was selected, consisting of 5 % salt with a reduced sodium content, 4% sugar, 0.35-0.50% citric acid. It was found that carrying out the salting process for 72-96 hours provides a low-salted fillet with a salt content of 3.5% with high organoleptic parameters, which are determined by the amino nitrogen content of 110-130 mg/100 g of the product and the buffering capacities of 40-45 degrees.


1987 ◽  
Vol 70 (4) ◽  
pp. 664-667
Author(s):  
Tee-Siaw Koh

Abstract Fifty-one laboratories from 14 countries participated in a survey on the determination of selenium (Se) in 8 bovine blood samples with Se concentrations ranging from 0.2 μmol/L (0.016 μg/mL) to 14 μmol/L (1.1 μg/mL). The methods used (and the percentage of participants using each method) were fiuorometry (61), hydride-generation atomic absorption spectrophotometry (AAS) (23), graphitefurnace AAS (6), gas chromatography (4), neutron activation analysis (4), and X-ray fiuorometry (2). There was little difference in the mean Se results obtained by fiuorometry or hydride-generation AAS (P > 0.05). Mean intralaboratory coefficients of variation (CVs) from known replicates ranged from 4 to 14% for all samples. Interlaboratory CVs were related to blood Se concentration and increased to 55% at Se levels below 0.4 μmol/L (0.032 μg/mL). Laboratories that used quality control (QC) schemes had lower interlaboratory CVs than those that did not, but the advantage began to diminish at blood Se concentration below 0.4 μmol/L (0.032 μg/mL). The high interlaboratory CVs, coupled with the false assurance from the low intralaboratory CVs and the ineffectiveness of the QC schemes at blood Se concentrations below 0.4 μmol/L (0.032 μg/mL), are of concern in diagnosis of marginal Se deficiency in livestock where the concentrations of interest are in the range 0.15-0.5 μmol/L (0.012-0.039 μg/mL).


1983 ◽  
Vol 66 (5) ◽  
pp. 1234-1241
Author(s):  
Luis F Corominas ◽  
Roberto A Navarro ◽  
Pedro Rojas ◽  
◽  
M Aihara ◽  
...  

Abstract A collaborative study was carried out to compare AOAC method 2.147-2.150 for determining sodium in fertilizers with the atomic absorption spectrophotometric (AAS) method. Twelve synthetic NPK samples, 6 pairs of blind duplicates (0.06-8.5% Na), were sent to 22 collaborators; a total of 13 sets of results were received and evaluated by the modified matched pairs technique. The AAS method showed better performance in samples with low sodium content and high potassium content. The AAS method has been adopted official first action for determining sodium in fertilizers.


1984 ◽  
Vol 48 (348) ◽  
pp. 425-429 ◽  
Author(s):  
Richard A. Batchelor ◽  
Judith A. Kinnaird

Abstract Blue-coloured gem-quality spinel from Nigeria was analysed by wet chemical methods (using atomic absorption spectrophotometry) and investigated by X-ray diffraction. The results showed it to be gahnite (unit cell dimension a=8.091±0.003 Å) containing 36.7% ZnO, 3.58% FeO, and 0.12% MgO. The spinel has an RI of 1.79 and density between 4.4 and 4.59. Broadening of the n[111] XRD reflections indicates a measure of compositional heterogeneity. The gahnite analyses were compared with compositions of zinc spinels from other parts of the world. The analyses cluster into two distinct groups, Mg-rich spinels of metamorphic origin and Mg-poor spinels (including the Nigerian gahnite) with igneous affinities. Diadochy seems to operate within the zinc spinel structure between (Zn + Mn) and (Fe + Mg).


1964 ◽  
Vol 30 (1) ◽  
pp. 94-96 ◽  
Author(s):  
Saul Jarcho

AbstractIn 1932 Haury described lead-glaze pottery from the Southwest. In view of his report, it appeared desirable to find out whether the makers of such pottery suffered from lead poisoning. A series of 46 bone specimens from Kinishba, where lead-glaze pottery was made, and a control series of 33 specimens from Point of Pines, where such pottery is not known to have been made, were screened by X-ray and by X-ray diffraction. The 11 most promising specimens were then analyzed by atomic absorption spectrophotometry. Lead was found in quantities believed to be below the toxic range; concentrations in the control series from Point of Pines were, with few exceptions, higher than in the experimental series from Kinishba.


1969 ◽  
Vol 77 (3-4) ◽  
pp. 129-135
Author(s):  
Teresita Rodríguez

The effect of microwave and conventional hot-water blanching upon selected mineral (calcium, copper, iron, potassium, magnesium, manganese, sodium, zinc) losses in green and dry white beans (Phaseolus vulgaris) was studied. The mineral content was determined by atomic absorption spectrophotometry. Microwave blanching resulted in significantly greater losses of calcium, magnesium and potassium, but in significantly greater manganese retention in dry white beans. Neither method resulted in significant mineral changes in green white beans. In practical terms, the microwave blanching treatment did not have the expected performance in relation to mineral retention when compared to the traditional hot-water blanching, thus suggesting that it may not be a viable alternative blanching method under all circumstances.


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