scholarly journals STUDIES ON SALT ACTION

1925 ◽  
Vol 9 (2) ◽  
pp. 123-136
Author(s):  
Howard J. Shaughnessy ◽  
Katharine I. Criswell

1. The strain of Bacterium coli used in these experiments multiplies in distilled water at pH 6.0 and pH 8.0 and in Ringer-Locke solution at pH 6.0. Under all the other conditions studied the numbers decrease with the passage of time. 2. The electrophoretic charge of the cells is highest in distilled water at pH 6.0 and pH 8.0. Under all other conditions studied the velocity of migration is decreased, but the decrease is immediate and is not affected by more prolonged exposure. 3. A strongly acid solution (pH 2.0) causes a rapid death of the cells and a sharp decrease in electrophoretic charge, sometimes leading to complete reversal. 4. A strongly alkaline solution (pH 11.0) is almost as toxic as a strongly acid one, although in distilled water the organisms survive fairly well at this reaction. Electrophoretic charge, on the other hand, is only slightly reduced in such an alkaline medium. 5. In distilled water, reactions near the neutral point are about equally favorable to both viability and electrophoretic charge, pH 8.0 showing slightly greater multiplication and a slightly higher charge than pH 11.0. In the presence of salts, however, pH 8.0 is much less favorable to viability and somewhat more favorable to electrophoretic charge than is pH 6.0. 6. Sodium chloride solutions, in the concentrations studied, all proved somewhat toxic and all tended to depress electrophoretic charge. Very marked toxicity was, however, exhibited only in a concentration of .725 M strength or over and at pH 8.0, while electrophoretic migration velocity was only slightly decreased at a concentration of .0145 M strength. 7. Calcium chloride was more toxic than NaCl, showing very marked effects in .145 M strength at pH 8.0 and in 1.45 M strength at pH 6.0. It greatly depressed electrophoretic charge even in .0145 M concentration. 8. Ringer-Locke solution proved markedly stimulating to the growth of the bacteria at pH 6.0 while at pH 8.0 it was somewhat toxic, though less so than the solutions of pure salts. It depressed migration velocity at all pH values, being more effective than NaCl in this respect, but less effective than CaCl2. 9. It would appear from these experiments that a balanced salt solution (Ringer-Locke's) may be distinctly favorable to bacterial viability in water at an optimum reaction while distinctly unfavorable in a slightly more alkaline solution. 10. Finally, while there is a certain parallelism between the influence of electrolytes upon viability and upon electrophoretic charge, the parallelism is not a close one and the two effects seem on the whole to follow entirely different laws.

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Cicero Antônio Mariano dos Santos ◽  
Joacir do Nascimento ◽  
Kelly Cristina Gonçalves ◽  
Giovani Smaniotto ◽  
Leonardo de Freitas Zechin ◽  
...  

AbstractSpodoptera frugiperda is a pest of economic importance for several crops with resistance reports to Bt crops and pesticides. Eco-friendly Bt biopesticides may be an alternative to chemical insecticides due to their selectivity and specificity. However, the efficacy of Bt biopesticides may be influenced by the association with other chemicals, such as adjuvants. This study evaluated the compatibility and toxicity of Bt biopesticides mixed with adjuvants for the control of S. frugiperda. The treatments included the association of Dipel SC and Dipel PM with adjuvants. Compatibility tests were used to evaluate the Bt mixture. Bt suspensions obtained from mixtures of Bt and adjuvants at 106 and 3 × 108 spores/mL−1 were used to evaluate S. frugiperda mortality and distilled water was used as the control. The addition of the adjuvant LI increased growth and sporulation, indicating compatibility with Bt biopesticides. The other adjuvants were toxic to reducing Bt growth and sporulation. Only the mixture of Bt with LI and Bt alone was effective to S. frugiperda. The addition of adjuvants to Bt biopesticide affect the Bt sporulation, growth and mortality.


Author(s):  
João Felipe Besegato ◽  
Gabriela Dos Santos Ribeiro Rocha ◽  
Marlene De Sousa Amorim ◽  
Fabio Martins Salomão ◽  
Daniel Poletto ◽  
...  

Objective: to measure pH values of bleaching agents that are indicated to intracoronal bleaching technique in different time intervals. Methods: Each group (G) received five samples (n=5): G1 – distilled water (AD); G2 – hydrogen peroxide (H2O2) 30%; G3 – sodium perborate (PbS) + AD; G4 – PbS + H2O2 30%; G5 – sodium percarbonate (PcS) + AD; and G6 – PcS + H2O2 30%. pH values were stated using a digital pHmeter, in different time intervals: immediately after handling (T0), 24 hours (T1) and 168 hours after handling (T2). The results were submitted to statistical analysis through Kruskal-Wallis and Mann Whitney tests, in this order, allowing multiple comparisons among the groups. To verify the effect of time in each group, Friedman test was applied. Results: In the evaluation of the effect of time in each group, it was observed that G2 presented acid behavior, while the other groups exhibited values close to neutrality or alkaline. Conclusions: H2O2 30% was the only agent that showed acidic behavior in every evaluation time. Meanwhile, PcS + H2O had the highest pH values.


Table II : Quantitative determination of carbonyl compounds at different odour sources (concentrations in ppb) Rendering plant Gelatine plant neighbourhood neighbourhood Formaldehyde 40 16 Acetaldehyde 39 24 Acetone 36 73 Prcpanal 10 -Isobutyraldehyde 10 30 Pentanal 15 19 Hexanal 3.52 Heptanal 12.5 Octanal 10.5 Nonanal 1 2 acids (figure 7). However extractions always involve a serious decrease in sensitivity, while evaporation of the extract produces a solution in 0.1-0.5 ml of solvent, and only 1 pi of it can be brought in the gas chromatograph. Therefore work is in progress to enhance sensitivity by converting acids in­ to halogenated derivatives, which can be GC-analysed with the more sensitive electron-capture detector. For thiols a similar procedure is investigated as with aldehydes. One possibility is absorption of thiols in an alkaline solution and reaction with 2,4-dinitrochlorobenzene, yielding 2,4-dinitrofenylsulfides, which are analysed by HPLC (9). Sane improvements on removal of reagents at the one hand and on separation of sane by-products on the other hand have to be achieved in order to in­ crease the sensitivity with another factor of ten. 5. CONCLUSION The actual scope and limitations of chemical analysis of odour show that all problems can be tackled as far as emission is concerned. For iititiission measurements seme progress is necessary, but there is no essential reason why chemical analysis would be unable to attain the desired sensitivity for all types of odorants. There is no doubt that in a few years the last dif­ ficulties will be solved. In order to achieve real control of odour nui­ sance, automatic measurement is necessary on a long time basis. There again seme technical development is to be expected. Does this mean that machines are going to decide if an odour is pre­ sent or not? By no means, while the population will always be the reference, and psychophysical measurements will be necessary to make chemical analysis possible.


2007 ◽  
Vol 59 (3) ◽  
pp. 227-231 ◽  
Author(s):  
S. Zivkovic ◽  
M. Devic ◽  
B. Filipovic ◽  
Z. Giba ◽  
D. Grubisic

The influence of high NaCl concentrations on seed germination in both light and darkness was examined in the species Centaurium pulchellum, C. erythraea, C. littorale, C. spicatum, and C. tenuiflorum. Salt tolerance was found to depend on the life history of the seeds. To be specific, seeds of all five species failed to complete germination when exposed to continuous white light if kept all the time in the presence of 100-200 mM and greater NaCl concentrations. However, when after two weeks NaCl was rinsed from the seeds and the seeds were left in distilled water under white light for an additional two weeks, all species completed germination to a certain extent. The percent of germination not only depended on NaCl concentration in the prior medium, but was also species specific. Thus, seeds of C. pulchellum, C. erythraea, and C. littorale completed germination well almost irrespective of the salt concentration previously experienced. On the other hand, seeds of C. tenuiflorum completed germination poorly if NaCl concentrations in the prior media were greater than 200 mM. When seeds after washing were transferred to darkness for an additional 14 days, they failed to complete germination if previously imbibed on media containing NaCl concentrations greater than 400 mM. However, the seeds of all species, even if previously imbibed at 800 mM NaCl, could be induced to complete germination in darkness by 1 mM gibberellic acid. .


2017 ◽  
Vol 23 (3) ◽  
pp. 329
Author(s):  
Ana Maria Oliveira Souza Alves ◽  
Jaianne Francielle Oliveira Santos Pimentel ◽  
Gustavo Ferreira Da Silva ◽  
Nilbe Carla Mapeli ◽  
Ana Maria Mapeli

The species Gerbera jamesonii Adlam has great economic importance in the ornamental sector, due to exuberance of floral stems. However, florists face some challenges such as postharvest handling and difficulty of conservation. Therefore, this study aimed to characterize the non-structural carbohydrate content in different floral stages of G. jamesonii var. Dawn and evaluate the effect of preservative solutions during the postharvest storage of this species. For this purpose, it was quantified TSS, RS and NRS from the seven stages of gerbera stems ontogeny (E1, E2, E3, E4, E5, E6 and E7). The preservative solutions used were: T1) distilled water; T2) citric acid (100 mg L-1); T3) glucose (20 g L-1); T4) gibberellic acid (GA3 , 5 mg L-1); T5) calcium chloride (CaCl2 , 20g L-1) and T6) Sodium Thiosulphate (STS, 20 mM). The effect of preservative solutions were assessed daily, considering the longevity of flowers, variation in the absorption of preservative solution, pH of the solution and fresh mass variation. The experimental design was completely randomized with four replicates. There was a difference in carbohydrate metabolism during floral opening and senescence. In the orange bracts there was a lower TSS content, while in the inflorescences it was observed a reduction in the yellowish, greenish-green and greenish stages. The content of RS increased in the bracts, whereas in the inflorescence there was no difference. The NRS content was higher in the orange bracts, showing lower rates in the inflorescences in yellowish and yellowish greenish stages. The preservative solutions had an impact, on the floral stem longevity, varying according to the solutions used, i.e. CaCl2 and STS reduced the durability of gerbera flower in 9.25 and 11.5 days, respectively, compared to stems kept in distilled water. The glucose solution did not promote a significant difference compared to water. Therefore, we conclude that there is variation in the metabolism of non-structural carbohydrates during the floral development of G. jamesonii var. Dawn and the tested solutions were not effective in promoting postharvest conservation of gerbera.


2016 ◽  
Vol 13 (4) ◽  
pp. 639-648
Author(s):  
Baghdad Science Journal

This study was designed to investigate the effect of the Clenbuterol drug in some physiological parameters of Liver, Kidney function and lipidprofie concentration. Fourty adult male rabbits were used in this study. The animals were randomly divided into four groups,the first group was given distilled water (control) ,while the other third groups were given (2,4,6 µg/kg) of Clenbuterol drug for 30 days. Blood samples were collected after 14 and 30 days of the treatment for biochemical study. Drug caused non significant increase(P


2012 ◽  
Vol 2 (3) ◽  
pp. 899-909
Author(s):  
Rodolfo Bernal-Gamboa ◽  
Javier Nieto

One experiment analyzed whether context dependency of a flavor-illness association depends on the extinction of a different flavor-illness association in rats. There were two sessions per day, one in context A and the other session in context B. A half of the rats were allowed to drink distilled water within context B, while the other half of the group spent the same amount of time in context B without access to water. In context A, half of the subjects received conditioning and extinction of flavor X, while the other half did not received extinction. Then conditioning of flavor Y was conducted for all rats in context A. Finally, testing of Y was conducted in context A for half of the rats, while the other half received the test in context B. Results shown that extinction of flavor X affected the recovery of subsequently acquired information about flavor Y regardless the treatment received in context B. This data is consistent with Attentional Theory of Context Processing.


PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e2020 ◽  
Author(s):  
Daniela Campaniello ◽  
Antonio Bevilacqua ◽  
Milena Sinigaglia ◽  
Maria Rosaria Corbo

Ultrasound (US), Thermo-sonication (TS) and High Pressure Homogenization (HPH) were studied as tools to inactivate the spores ofPenicilliumspp. andMucorspp. inoculated in distilled water. For US, the power ranged from 40% to 100%, pulse from 2 to 10 s, and duration of the treatment from 2 to 10 min. TS was performed combining US (40–80% of power, for 8 min and pulse of 2 s) with a thermal treatment (50, 55 and 60°C at 4, 8 and 12 min). Homogenization was done at 30–150 MPa for 1, 2 and 3 times. Power was the most important factors to determine the antifungal effect of US and TS towards the conidia ofPenicilliumspp.; on the other hand, in US treatmentsMucorspp. was also affected by pulse and time. HPH exerted a significant antifungal effect only if the highest pressures were applied for 2–3 times.


2017 ◽  
pp. 836-853
Author(s):  
N. Suchkova ◽  
E. Darakas ◽  
J. Ganoulis ◽  
Y. Vergeles

In this work the suitability of several plant species for phytoremediation under natural and artificially installed conditions was studied. Brassica napus, Medicago sativa, Zea mays, Triticum aestivum, and Hordeum vulgare were grown in pots with sewage sludge from Sindos Main WWTP in Thessaloniki and from Sindos Industrial WWTP in Thessaloniki, Greece. The first series of experiments included comparing measurements of various parameters for the above mentioned plants and the sludge to those for control samples (the same plants growing in compost). It was shown that shoot growth was less reduced in T. aestivum and H. vulgare than in the other plant species studied. B. napus had lower germination tax, followed by M. sativa with the lowest germination tax. Generally B. napus, giving less biomass production than Z. mays and T. aestivum, is characterised by a higher ability to accumulate heavy metals like Cd, Cu, Ni, Pb, Zn, Cr, As and Hg. The second series of experiments included comparing measurements of various parameters of B. napus grown in sludge and treated each 7 days with metal solutions of Ni, Zn and Pb containing 10-2mg/l, 10-4mg/l, 10-6mg/l of each metal, to those for control plants treated with double distilled water. Results showed that shoot growth of B. napus were increased at treatments with lower concentrations of metals (10-6 mg/l) and control (treatment with d-distilled water). At the same time uptake of metal ions was increased with the concentration of the solution, i.e. at higher concentrations (10-2 mg/l). It is truly for Pb and Zn, transfer coefficient TC of which (indicates a plant’s potential to concentrate a metal) was quite high 15 % and 7 % correspondingly. It was noticed that B. napus has high ability to accumulate Cr, from the other hand it did not accumulate Ni (at present case).


2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Ovidiu-Dumitru Ilie ◽  
Emanuela Paduraru ◽  
Madalina-Andreea Robea ◽  
Ioana-Miruna Balmus ◽  
Roxana Jijie ◽  
...  

Background. As every organ within the body, the brain is also extremely susceptible to a plethora of noxious agents that change its chemistry. One component frequently found in current products against harmful species to crops is rotenone whose effect under prolonged exposure has been demonstrated to cause neurodegenerative disorders such as Parkinson’s disease. The latest reports have indeed revealed that rotenone promotes Parkinson’s in humans, but studies aiming to show congruent effects in zebrafish (Danio rerio) are lacking. Material and Methods. In this context, the aim of the present study was to demonstrate how chronic administration of rotenone for 3 weeks impairs the locomotor activity and sociability and induces oxidative stress in zebrafish. Results. There were no statistically significant differences following the analysis of their social interaction and locomotor tests ( p > 0.05 ). However, several exceptions have been noted in the control, rotenone, and probiotics groups when we compared their locomotor activity during the pretreatment and treatment interval ( p < 0.05 ). We further assessed the role of rotenone in disturbing the detoxifying system as represented by three enzymes known as superoxide dismutase (SOD), glutathione peroxidase (GPx), and malondialdehyde (MDA). Despite the fact that there were no statistically significant changes within SOD and GPx levels between the control group and rotenone, probiotics, and rotenone + probiotics ( p > 0.05 ), relevant changes have been observed between the analyzed groups ( p < 0.05 and p < 0.005 , respectively). On the other hand, significant differences ( p < 0.05 ) have been observed for MDA when we analyzed the data between the control group and the other three groups. Conclusions. Our results suggest that rotenone can be successfully used to trigger Parkinson’s disease-related symptomatology in zebrafish.


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