The Reactions of Pygosteus Pungitius L. to Toxic Solutions

1947 ◽  
Vol 24 (1-2) ◽  
pp. 110-122
Author(s):  
J. R. ERICHSEN JONES
Keyword(s):  
Tap Water ◽  
Glass Tube ◽  
Negative Reaction ◽  
Small Fish ◽  
Toxic Substances ◽  
Copper Salts ◽  
Concentration Difference ◽  
Low Toxicity ◽  
High Concentrations ◽  
Flowing Solution

An apparatus is described in which small fish (Pygosteus pungitius L.) are confined in a horizontal glass tube, half of which is filled with flowing tap water and half with flowing solution. Solution and water are very sharply differentiated, so that the concentration difference the fish encounter is known. The directions of flow can be rapidly reversed in order to check the result. The movements of the fish are recorded for 7-120 min., according to the degree of toxicity of the substance tested. A negative reaction is shown towards 1% ethyl alcohol, 1/10,000-1/5000 chloroform and 0.1-0.4% formalin (% HCHO). High concentrations of these substances may stupefy the fish so rapidly that a pseudo-positive reaction appears. A sharp negative reaction is displayed towards 0.003-0.001N mercuric chloride; at 0.0003 the reaction is delayed, at 0.0001 is indefinite, and at 0.00004N solution, though of comparatively high toxicity, does not appear to be detected. Zinc sulphate appears to be detected and avoided at concentrations at least as low as 0.0003N. This concentration is of comparatively low toxicity and may be exceeded in streams polluted by effluents from zinc mines. Copper sulphate is only detected and avoided at extremely high concentrations (0.1N). At 0.04N the reaction is vague, and at 0.01-0.001N the fish swim into the solution where they become stupefied and lie motionless, so that the reaction appears positive. Copper salts appear to impair or destroy the stickleback's ability to distinguish other toxic substances.

Antifungal Activity Directed Toward the Cell Wall by 2-Cyclohexylidenhydrazo- 4-Phenyl-Thiazole Against Candida albicans

2019 ◽  
Vol 19 (4) ◽  
pp. 428-438 ◽  
Author(s):  
Nívea P. de Sá ◽  
Ana P. Pôssa ◽  
Pilar Perez ◽  
Jaqueline M.S. Ferreira ◽  
Nayara C. Fonseca ◽  
...  
Keyword(s):  
Cell Wall ◽  
Candida Albicans ◽  
Antifungal Activity ◽  
Mammalian Cells ◽  
C Elegans ◽  
Buccal Epithelial Cells ◽  
Mutant Strains ◽  
Low Toxicity ◽  
High Concentrations ◽  
Mic Value

<p>Background: The increasing incidence of invasive forms of candidiasis and resistance to antifungal therapy leads us to seek new and more effective antifungal compounds. </P><P> Objective: To investigate the antifungal activity and toxicity as well as to evaluate the potential targets of 2- cyclohexylidenhydrazo-4-phenyl-thiazole (CPT) in Candida albicans. </P><P> Methods: The antifungal activity of CPT against the survival of C. albicans was investigated in Caenorhabditis elegans. Additionally, we determined the effect of CPT on the inhibition of C. albicans adhesion capacity to buccal epithelial cells (BECs), the toxicity of CPT in mammalian cells, and the potential targets of CPT in C. albicans. </P><P> Results: CPT exhibited a minimum inhibitory concentration (MIC) value of 0.4-1.9 µg/mL. Furthermore, CPT at high concentrations (>60 x MIC) showed no or low toxicity in HepG2 cells and <1% haemolysis in human erythrocytes. In addition, CPT decreased the adhesion capacity of yeasts to the BECs and prolonged the survival of C. elegans infected with C. albicans. Analysis of CPT-treated cells showed that their cell wall was thinner than that of untreated cells, especially the glucan layer. We found that there was a significantly lower quantity of 1,3-β-D-glucan present in CPT-treated cells than that in untreated cells. Assays performed on several mutant strains showed that the MIC value of CPT was high for its antifungal activity on yeasts with defective 1,3-β-glucan synthase. </P><P> Conclusion: In conclusion, CPT appears to target the cell wall of C. albicans, exhibits low toxicity in mammalian cells, and prolongs the survival of C. elegans infected with C. albicans.</p>

Integrated faecal sludge treatment and recycling through constructed wetlands and sunflower plant irrigation

2006 ◽  
Vol 54 (11-12) ◽  
pp. 155-164 ◽  
Author(s):  
T. Koottatep ◽  
C. Polprasert ◽  
S. Hadsoi
Keyword(s):  
Plant Biomass ◽  
Tap Water ◽  
Oxygen Demand ◽  
Application Rate ◽  
Solid Loading ◽  
Sunflower Plant ◽  
Increase With Increase ◽  
High Concentrations ◽  
Sanitation Systems ◽  
Faecal Sludge

Faecal sludge (FS) from the on-site sanitation systems is a nutrient-rich source but can contain high concentrations of toxic metals and chemicals and infectious micro-organisms. The study employed 3 vertical-flow CW units, each with a dimension of 5×5×0.65 m (width×length×media depth) and planted with cattails (Typha augustifolia). At the solid loading rate of 250 kg total solids (TS)/m2.yr and a 6-day percolate impoundment, the CW system could achieve chemical oxygen demand (COD), TS and total Kjeldahl nitrogen (TKN) removal efficiencies in the range of 80–96%. A solid layer of about 80 cm was found accumulated on the CW bed surface after operating the CW units for 7 years, but no clogging problem has been observed. The CW percolate was applied to 16 irrigation sunflower plant (Helianthus annuus) plots, each with a dimension of 4.5×4.5 m (width×length). In the study, tap water was mixed with 20%, 80% and 100% of the CW percolate at the application rate of 7.5 mm/day. Based on a 1-year data in which 3 crops of plantation were experimented, the contents of Zn, Mn and Cu in soil of the experimental plots were found to increase with increase in CW percolate ratios. In a plot with 100% of CW percolate irrigation, the maximum Zn, Mn and Cu concentrations of 5.0, 12.3 and 2.5 mg/kg, respectively, were detected in the percolate-fed soil, whereas no accumulation of heavy metals in the plant tissues (i.e. leaves, stems and flowers) of the sunflower were detected. The highest plant biomass yield and oil content of 1000 kg/ha and 35%, respectively, were obtained from the plots fed with 20% or 50% of the CW percolate.

scholarly journals CHARACTERISTICS OF LEACHATE AT IHIAGWA DUMPSITE, IMO STATE NIGERIA AND THEIR IMPLICATIONS FOR SURFACE WATER POLLUTION

2021 ◽  
pp. 1-11
Author(s):  
CT Nelson ◽  
GT Amangabara ◽  
CO Owuama ◽  
CN Nzeh ◽  
CN Uyo
Keyword(s):  
Heavy Metals ◽  
Chemical Properties ◽  
Total Solid ◽  
Toxic Substances ◽  
Landfill Leachates ◽  
Total Chloride ◽  
Metal Cyanide ◽  
Physico Chemical ◽  
High Concentrations ◽  
Total Dissolved Solid

Open dumpsite is the most common way to eliminate solid urban wastes in this part of the world. An important problem associated to landfills and open dumpsite is the production of leachates. The leachates from these dumpsites have many toxic substances, which may adversely affect the environmental health. Thus in order to have a better management of characteristics of Ihiagwa-Nekede waste dump leachates, representative leachate samples were collected and analyzed for Physico-chemical properties and levels of heavy metals in them. Results indicate pH7.38, temperature 28.30 ℃ - 28.40℃, total dissolved solid 124.01mg/l-125.45mg/l, magnesium hardness 4.40mg/l-7.32mg/l, sulphate 3.60mg/l-3.70mg/l, and nitrate 27.00mg/l-27.60mg/l. Other parameters indicated as follows Conductivity1910𝜇𝑠/𝑐𝑚-1930.00 𝜇𝑠/𝑐𝑚, total chloride 891.72mg/l-891.74mg/l, carbonate 1708.00mg/l-1904.00mg/l, Ammonia 9.39mg/l-9.40mg/l, calcium hardness 373.17mg/l-375.61mg/l, total solid 2423.00mg/l-2454.00mg/l, phosphate 13.52mg/l-13.54mg/l. The heavy metal: cyanide 2.25mg/l-2.33mg/l, zinc 18.08mg/l-18.38mg/l, copper 19.90mg/l20.48mg/l, iron10.67mg/l-10.82mg/l, lead 1.27mg/l-1.41mg/l, and manganese 3.00mg/l-3.61mg/l, all these exceeded the WHO standards. The obtained results showed that the landfill leachates are characterized by high concentrations of heavy metals and other disease causing elements and therefore require urgent treatment to forestall the contamination of groundwater system and the nearby Otamiri River.

scholarly journals Can a one-sampling campaign produce robust results for water quality monitoring? A case of study in Itupararanga reservoir, SP, Brazil

2016 ◽  
Vol 28 (0) ◽  
Author(s):  
Frederico Guilherme de Souza Beghelli ◽  
Marcelo Luiz Martins Pompêo ◽  
Mônica Páscoli ◽  
Vivian Silva Lira ◽  
Renata de Lima ◽  
...  
Keyword(s):  
Benthic Macroinvertebrates ◽  
Water Quality Monitoring ◽  
Poor Quality ◽  
Fecal Coliforms ◽  
Toxic Substances ◽  
Nitrogen And Phosphorus ◽  
Biological Variables ◽  
Sampling Campaign ◽  
Sampling Points ◽  
High Concentrations

Abstract Aim: The aim of this study was to conduct a rapid and comprehensive analysis of the reservoir using physical, chemical and biological variables comprising water and sediment as also to verify if a one-sampling campaign can produce information that is robust enough for monitoring purposes. Methods One-sampling campaign was performed along the central body of Itupararanga reservoir comprising five sampling points. The following physico-chemical and biological variables were measured in each of them from water samples: temperature, pH, concentration of dissolved oxygen, electric conductivity, suspended matter, total nitrogen and phosphorus and fecal coliforms. A genotoxicity assay with Allium cepa was also performed with water from each one of the five sampling points. As a complement, the phytoplankton and benthic macroinvertebrates communities were also analyzed in the two most distant sampling points (P1 and P5). Results Results indicate a scenario with eutrophication and toxicity. High concentrations of fecal coliforms were recorded and there is a worrying prevalence of cyanobacteria - potential toxin producers - in phytoplankton community. Benthic macroinvertebrates analysis suggests poor quality of the water and sediments. Genotoxicity tests suggest the presence of toxic substances along the waterbody. Conclusions It is concluded that Itupararanga reservoir has water with poor quality that could be related to the land uses around the reservoir. The comprehensive approach performed here - where distinct sources of monitoring variables was considered - despite the rapid protocol (one campaign), was enough to respond to the distinct anthropic impacts received by the reservoir. Considering it, this approach is recommended as a rapid diagnostic tool.

Debinding Behaviors and Mechanism of Injection Molded ZrO2 Ceramics Using Kerosene as Solvents

2012 ◽  
Vol 512-515 ◽  
pp. 431-434 ◽  
Author(s):  
Wei Liu ◽  
Zhi Peng Xie ◽  
Li Li Zhang ◽  
Xian Feng Yang
Keyword(s):  
Reaction Rate ◽  
Low Cost ◽  
Controlling Factor ◽  
Solid Loading ◽  
Concentration Difference ◽  
Initial Stage ◽  
Low Toxicity ◽  
Injection Molded ◽  
Increasing Temperature ◽  
Main Factor

In this study, low-cost kerosene with low toxicity was used as organic solvent to research the solvent debinding behavior of ceramic compact produced by injection molding. The Influences of time, temperature and solid loading on the debinding rate were investigated, the mechanism of which was also discussed. The results show that: The debinding rate increased with increasing temperature and decreased with extended time; Diffusion is the controlling factor at the initial stage and temperature was the main factor influencing the reaction rate; Dissolution is the controlling factor and concentration difference was the main factor at the later stage; The higher the solid loading of green body, the slower the debinding rate and the lower the final proportion of binder removal.

INFLUENCE OF ORGANIC MATTER ON THE GERMICIDAL EFFICIENCY OF QUATERNARY AMMONIUM AND HYPOCHLORITE COMPOUNDS

1948 ◽  
Vol 26f (2) ◽  
pp. 91-104 ◽  
Author(s):  
C. K. Johns
Keyword(s):  
Staphylococcus Aureus ◽  
Organic Matter ◽  
Quaternary Ammonium ◽  
Tap Water ◽  
Skim Milk ◽  
Distilled Water ◽  
Water Solutions ◽  
E Coli ◽  
Test Organisms ◽  
High Concentrations

Using Staphylococcus aureus and Eschericha coli as test organisms, the influence of various concentrations of skim milk on the germicidal potency of Roccal and of Dalglish hypochlorite solutions was studied. Both germicides retained their activity in the presence of unexpectedly high concentrations of skim milk, especially against S. aureus. Small concentrations frequently showed a slight potentiating effect in both laboratory and plant tests. The effectiveness of the hypochlorite fell off sharply beyond a certain concentration, while that of Roccal declined more gradually. Solutions of Roccal prepared with tap water were decidedly less active against E. coli than those prepared with distilled water. With the hypochlorite, tap water solutions were equally effective. Against S. aureus, a similar difference was noted although to a lesser extent. Added skim milk depressed the germicidal action of tap water solutions of Roccal to a greater extent than for distilled water solutions, while for the hypochlorite the reverse held true.

scholarly journals Copper Supplementation in Watering Solution Reaches the Xylem But Does Not Protect Tobacco Plants Against Xylella fastidiosa Infection

Plant Disease ◽  
2020 ◽  
Vol 104 (3) ◽  
pp. 724-730 ◽  
Author(s):  
Qing Ge ◽  
Paul A. Cobine ◽  
Leonardo De La Fuente
Keyword(s):  
Biofilm Formation ◽  
Inductively Coupled Plasma ◽  
Tap Water ◽  
Xylella Fastidiosa ◽  
In Vitro Study ◽  
Optical Emission ◽  
In Planta ◽  
Inductively Coupled ◽  
High Concentrations

Xylella fastidiosa is a xylem-limited plant pathogenic bacterium that causes disease in many crops worldwide. Copper (Cu) is an antimicrobial agent widely used on X. fastidiosa hosts to control other diseases. Although the effects of Cu for control of foliar pathogens are well known, it is less studied on xylem-colonizing pathogens. Previous results from our group showed that low concentrations of CuSO4 increased biofilm formation, whereas high concentrations inhibited biofilm formation and growth in vitro. In this study, we conducted in planta experiments to determine the influence of Cu in X. fastidiosa infection using tobacco as a model. X. fastidiosa-infected and noninfected plants were watered with tap water or with water supplemented with 4 mM or 8 mM of CuSO4. Symptom progression was assessed, and sap and leaf ionome analysis was performed by inductively coupled plasma with optical emission spectroscopy. Cu uptake was confirmed by increased concentrations of Cu in the sap of plants treated with CuSO4-amended water. Leaf scorch symptoms in Cu-supplemented plants showed a trend toward more severe at later time points. Quantification of total and viable X. fastidiosa in planta indicated that CuSO4-amended treatments did not inhibit but slightly increased the growth of X. fastidiosa. Cu in sap was in the range of concentrations that promote X. fastidiosa biofilm formation according to our previous in vitro study. Based on these results, we proposed that the plant Cu homeostasis machinery controls the level of Cu in the xylem, preventing it from becoming elevated to a level that would lead to bacterial inhibition.

scholarly journals Anticorrosion Behaviour of Calcareous Deposits Formed on Steel Heat-Exchange Surfaces

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Georgii Vasyliev ◽  
Svitlana Vasylieva
Keyword(s):  
Corrosion Rate ◽  
Deposition Time ◽  
Tap Water ◽  
Steel Corrosion ◽  
Glass Tube ◽  
Linear Polarization Resistance ◽  
Scale Thickness ◽  
Calcareous Deposits ◽  
Scale Deposition ◽  
Steel Heat

A new electrode to study both scaling and corrosion processes of mild steel in tap water was developed. Two identical steel rings are placed on the outside of a glass tube which is heated from inside with an electric spiral; the rings are connected to a corrometer to form a two-electrode corrosion probe. The corrosion rate variations with scale thickness, scale deposition time, and solution composition are measured using the linear polarization resistance technique. The deposited scale was formed of calcite crystals of 50–100 μm as established with SEM and XRD. The scale layer of 0.2 mm formed in tap water within 90 hours reduces the steel corrosion rate from 0.8 to 0.1 mm/year and serves as a barrier layer to prevent further corrosion.

Horizontal Mobility of Heavy Metals from Dumpsite in North Central States, Nigeria

2020 ◽  
Vol 15 (1) ◽  
pp. 8-14
Author(s):  
J.D. Bala ◽  
J.J. Musa ◽  
H.I. Mustapha ◽  
I.Y. Yerima ◽  
D.E. Sunday ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Anthropogenic Activities ◽  
Total Concentration ◽  
Natural Soil ◽  
Toxic Substances ◽  
Central State ◽  
Dump Site ◽  
North Central ◽  
Uppermost Layer ◽  
High Concentrations

Industrialization and population growth has lead to the introduction of toxic substances into the environment as waste from manufacturing  processes. This study describes the horizontal mobility of this waste containing heavy metals from dump sites to the surrounding environment of North Central state, Nigeria. Soil samples were collected within the dumpsites and the immediate surrounding soil at distance of 10m and 20m away to assess the migration and potential bioavailability of Cr, Fe, Mn, Pb, Zn, Cu and Al. Total concentration of the heavy metals and their fractionation were determined. The results indicate that heavy metals are more concentrated in the uppermost layer with significant migration down the slope, thereby posing a threat to groundwater quality. In the fractions, the concentrations of the metals follow this sequence: Mn>Fe>Cu>Zn>Cr>Al. The mobility factors of the heavy metals are significantly high indicating high potential mobility and bioavailable forms of these heavy metals. The high concentrations of the heavy metals particularly Cr, as observed in the study is as a result of anthropogenic activities on enrichment of natural soil with bioavailable heavy metals. Consequently, there is a need to be cautious in the way waste that is generated from heavy metals sources is added to natural soil. Key words: Dump site; Environment; Heavy metals; Soil; Waste

scholarly journals Intracellular Proliferation of Legionella pneumophila in Hartmannella vermiformis in Aquatic Biofilms Grown on Plasticized Polyvinyl Chloride

2004 ◽  
Vol 70 (11) ◽  
pp. 6826-6833 ◽  
Author(s):  
Melanie W. Kuiper ◽  
Bart A. Wullings ◽  
Antoon D. L. Akkermans ◽  
Rijkelt R. Beumer ◽  
Dick van der Kooij
Keyword(s):  
Polyvinyl Chloride ◽  
Legionella Pneumophila ◽  
Biofilm Formation ◽  
Tap Water ◽  
Water System ◽  
Intracellular Growth ◽  
Mixed Microbial Community ◽  
Hartmannella Vermiformis ◽  
High Concentrations

ABSTRACT The need for protozoa for the proliferation of Legionella pneumophila in aquatic habitats is still not fully understood and is even questioned by some investigators. This study shows the in vivo growth of L. pneumophila in protozoa in aquatic biofilms developing at high concentrations on plasticized polyvinyl chloride in a batch system with autoclaved tap water. The inoculum, a mixed microbial community including indigenous L. pneumophila originating from a tap water system, was added in an unfiltered as well as filtered (cellulose nitrate, 3.0-μm pore size) state. Both the attached and suspended biomasses were examined for their total amounts of ATP, for culturable L. pneumophila, and for their concentrations of protozoa. L. pneumophila grew to high numbers (6.3 log CFU/cm2) only in flasks with an unfiltered inoculum. Filtration obviously removed the growth-supporting factor, but it did not affect biofilm formation, as determined by measuring ATP. Cultivation, direct counting, and 18S ribosomal DNA-targeted PCR with subsequent sequencing revealed the presence of Hartmannella vermiformis in all flasks in which L. pneumophila multiplied and also when cycloheximide had been added. Fluorescent in situ hybridization clearly demonstrated the intracellular growth of L. pneumophila in trophozoites of H. vermiformis, with 25.9% � 10.5% of the trophozoites containing L. pneumophila on day 10 and >90% containing L. pneumophila on day 14. Calculations confirmed that intracellular growth was most likely the only way for L. pneumophila to proliferate within the biofilm. Higher biofilm concentrations, measured as amounts of ATP, gave higher L. pneumophila concentrations, and therefore the growth of L. pneumophila within engineered water systems can be limited by controlling biofilm formation.

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